An analytical model to determine temperature in a single brake disc of multi-disc system is proposed. The model considers the convective cooling on the lateral surfaces of the disc and structure of composite friction material. Calculations were carried out for a disc made of carbon friction composites material Termar-ADF. The influence of heat transfer with environment, length of bundles with fibers, and concentration of fibers in composite on the temperature of the disc was investigated during single braking with constant deceleration. At the present time, high-speed and heavy-duty vehicles are extensively developed. These include high-speed rail and road transport, machines for military purposes, and, in particular, aircraft. For the successful operation of these categories of vehicles, appropriate braking devices are required that ensure their sufficient maneuverability. To design brakes, it is necessary to fulfill a complex of requirements , which is associated with the choice of friction materials, design of the brake unit, bench, and field tests .The braking system of modern passenger as well as military aircraft consists of package of fixed and rotating friction discs located inside the wheel. After switching on the brake, the special pistons compress package, the front surfaces of discs are in contact, and the process of friction braking begins. While the kinetic energy of the aircraft is absorbed, the friction between fixed and rotating discs causes that they are heated up even to 1500 °C, and temperatures of the friction surfaces reach up to 3000 °C. Therefore, the disc’s materials must be resistant enough to thermal shock .It is known that the friction polymer materials start to degrade at the temperature of 230 °C, and the degree of degradation increases with temperature within the range 269–400 °C . The higCarbon-carbon (C/C) composite materials are used at heavy working conditions, under which the temperature of the surface of friction can exceed 1500 °C and the bulk temperature 800 °C. CFCM such as Carbenix-4000 , Sepcarb , and Termar  have a low density and thermal linear expansion coefficient, high thermal conductivity, energy-absorption capability, stable coefficient of friction, and retain mechanical properties up to 2400–2800 °C ,12,13,14Depending on the purpose, various modifications of CFCM of the Termar type are used, which have different thermal, mechanical, and friction-wear properties. The discrete-reinforced transversely isotropic friction C/C Termar-ADF is a material with the formation of the original press package by the random arrangement of long fibers with use of special installation. Termar-ADF is fabricated using a pitch matrix reinforced by high modulus fibers with the average length being 20 mm. Fibrous materials are used for two cycles of impregnation with thermoplastic pitch using liquid-phase pyrolysis at 600 °C with pressure up to 100 MPa. Each cycle of impregnation is followed by carbonization at 1200 °C. The final heat treatment is performed at 2000 °C for 1 h [The calculation of the temperature regime and wear characteristics of the brake is the most important step in the design of the brake wheel as a whole. One of the most loaded elements of the brake, receiving greater thermal and mechanical loads, are the discs. Numerous natural tests and studies on the brakes have shown that the main factor determining the wear resistance of the C/C material of the discs, and hence the life of the product as a whole, is the temperature. Thus, the determination of the temperature field of the disc is necessary for predicting the durability of the brake. The result of test for heat pulsing friction of brand Termar-ADF carbon frictional composite material on the multipurpose friction machine IM-58-T2 is presented in . The effThe complex methodology for the design and manufacture of brakes for air wheels is presented in ,24. It iFor a multi-disc brake pair made of composite C/C materials, a numerical finite element method (FEM) solution of thermal problem of friction is obtained in , and an Multi-disc aircraft braking systems are subjected to heavy mechanical and thermal loads during braking. Typically, such systems are a package of identical discs. A scheme of such multi-disc system and the calculation diagram of the considered problem are presented in It is assumed that all friction discs have the same internal radius Taking the above-mentioned assumptions into account, distribution of the temperature nduction :(1)∂2T(zIntroducing the dimensionless variables and parameters:We write the problem in Equations (1)–(4) as:It should be noted that the adoption of the linear model in Equations (1)–(9) to determine the temperature field in the brake disc, imposes some restrictions on the possibility of its use in medium and heavy modes of operation of the brake, when the surface temperature reaches values above 450 and 750 °C, respectively . It is kBy replacing (16)T*=1 . After iTaking into account the sums of the series :(28)∑n=1From Equations (16) and (24)–(27), we find the dimensionless temperature of the disc in the form:On the heated surface ows that :(31)T*, we find the derivative:On the heated Using the sums (28) and (29), we have:Introducing the sum in Equation (38) into Equation (37), we confirms the execution of the initial condition in Equation (14).Finally, taking into account the notation in Equation (10), we obtain the temperature field in the disc:Formally, for With account of the sums (43)∑n=1Substituting tic disc :(46)T∗ ing form :(47)K^⊥=A unit cell of composite at the meso-level has the shape of a rectangular cuboid with length ectively . It shouThe effective coefficients of thermal conductivity for selected unit cell of composite in longitudinal rization . This meame part . BearingDivision of a unit cell by adiabatic planes 1-1 and 2-2 in the transverse direction is shown in Based on Equation (48), the effective coefficients of thermal conductivity of selected unit cell of composite in this case are determined in the form:ual part a, the toSubstituting the effective thermal resistance Division of the unit cell simultaneous by adiabatic 1-1 and 2-2 and isothermal 3-3 and 4-4 planes, respectively, in transverse and longitudinal directions, are presented in Proceeding as above, we obtain:The length Eliminating At the macro-level, the fiber bundles are arranged on the planes parallel to the front surfaces of the disc .The thermal conductivity of the disc in the axial direction is equal to the effective coefficient of thermal conductivity of the unit composite cell in the transverse direction on the meso-level:When determining the effective coefficient of thermal conductivity of the disc in the radial direction, the orientation of fiber bundles on the planes should be taken into account .If the bundles are arranged in the radial direction a, then: assumes that the number of bundles oriented in the radial and circumferential directions are equal. Therefore, the value of − Termar-ADF with randomly oriented fiber bundles  . The valThe change of temperature during braking on the friction surface of the disc is presented in ocouples . It can Changes of temperature during braking on different distances from heated surface of the disc are shown in The increase of heat exchange with an environment leads to linear decrease of maximum temperature the disc . The higChanges of effective thermophysical properties of composite material due to increasing the length face z=0 , their lWith increasing bundle length, the maximum temperature of the heated disc surface r a=30 mm. As showIncrease of concentration of bundles in composite results in increase of its thermal diffusivity and conductivity from values  Vb=0.95 . Such grievement . For theTemperature values calculated on the basis of the obtained analytical solution are consistent with appropriate experimental data presented in .During short-lasting . Calculations were carried out for a disc made up of carbon composite material Termar-ADF, widely applied in aircraft brakes. Due to performed numerical analysis, it is established that:The solution was obtained without considering possible variations of friction coefficient and material properties under the influence of temperature. It should be noted that consideration of thermal sensitivity and friction coefficient changes is possible by using the nonlinear models, which require numerical methods, such as FEM, to solve the proper thermal problems of friction. Some steps are taken to do this in , althougBased on these findings, we conclude that the proposed mathematical model allows with sufficient accuracy determining a temperature mode of a multi-disc brake at a single braking. Calculations are executed only for one frictional composite material, but the model proposed can be used for other materials, too. In such a case, it may be necessary to use other methods for obtaining effective thermophysical properties of the composite .


The moment of the addition of bentonite is a key factor. Volatile profile (SPME-GC-MS), foam characteristics , and sensory analyses were performed to study the effect of the distribution of the dosage of bentonite for stabilization of the wine among the addition on the base wine before the tirage  and during the tirage (addition of the remaining dosage for each case). Results showed that the addition of 50% of the bentonite to the base wine (before the tirage) resulted in sparkling wines with the lowest quantity of volatile compounds, mainly esters and norisoprenoids. No significant differences were found among the sparkling wines after 9 months of aging in relation to foam properties measured by Mosalux, although higher foamability and crown’s persistence were perceived in the sparkling wines with the addition of 75% and 100% of the bentonite dosage in sensory trials. The results of this study suggested that the amount of bentonite added as a fining agent in the tirage had greater effects than during the addition of this agent in the base wine.The addition of bentonite to wine to eliminate unstable haze-forming proteins and as a riddling adjuvant in the  The refusal of a wine by consumers can be driven by several reasons, some of which are subjective and others objective, such as defects in the product. Currently, haze formation in wines is an important concern for the industry because turbidity is one of the main causes of faulty perception by consumers and huge monetary losses due to the direct decrease of the quality of the wines and to the wine loss ,2.Different types of molecules such as polysaccharides, polyphenols, or proteins can contribute to the formation of haze owing to their instability . Among tBentonite is a natural clay mineral with a high amount of montmorillonite, which is negatively charged at wine pH and interacts electrostatically with the positively charged wine proteins that are adsorbed on the bentonite surface, thus producing flocculation, and removing them from the wine .During sparkling wine production, bentonite is generally used twice during the production process. First, it is added as a fining agent to achieve protein stabilization of the base wine, preventing the future formation of protein haze. Second, a small amount of bentonite is added as an adjuvant to the tirage solution to facilitate the flocculation of yeast strains during the process of riddling . The lacFurthermore, protein removal itself has its drawbacks, because the proteins and polysaccharides removed by bentonite affect the foamability of a sparkling wine ,14. SpecAmong the main types of proteins found in sparkling wine, i.e., those from grapes (chitinases and thaumatin-like proteins) and yeast (mainly mannoproteins), the ones from the fruit seem to play a major role in protein haze formation . To overDespite all these negative effects that it has on the final product, a specific amount of bentonite is required to achieve protein stabilization of base wines, and it is still the most widely employed and effective agent in wine protein stabilization . Hence, In addition to the quantity added, the moment of its addition is key to preserving the sensory characteristics of the wine. Some researchers have investigated the implications of bentonite treatments at different time points of the production process, especially before, during, and after fermentation ,8,17,21.However, despite the results found in these studies, the effects of the distribution of the needed dosage for stabilization during different phases of sparkling wine production have not been studied.The aim of this study was to determine such effects on two essential quality parameters of sparkling wines: volatile composition and foam properties. A Chardonnay sparkling wine was tested, and the protein stabilization dosage of bentonite was distributed among the stages of fining of the base wine and before the second fermentation of the tirage liquor (as a riddling adjuvant) in different proportions. In addition, sensory analysis was conducted to corroborate and establish the effects/implications of a higher or lower bentonite dosage added at each stage.The study was carried out using a Chardonnay base wine variety of the 2017 vintage made in the San Pedro de Tarapacá winery, which is located in the Casablanca Valley region of Chile. This base wine had a 10.4% vol. and a pH of 3.42.® G, Eaton Industries, Dublin, Ireland). ®Saccharomyces cerevisiae bayanus purchased from Lallemand (Chile) was used for a second fermentation in the bottle . For the preadaptation of the yeast, 40 g of yeast were dissolved in 400 mL of water at 35 °C. After 30 min, this mixture was added to 1 L of water containing 200 g of sugar perfectly dissolved, and following this, 4.5 L of wine were incorporated slowly. This mixture was incubated overnight at 25–30 °C. Next day, a viable yeast cell counting, and density measuring were done. The addition of sugar, water, and base wine was repeated but gradually increasing the base wine volume until the tirage to force the yeast to adapt to the rough conditions of this matrix. At this point, a second addition of bentonite was carried out, adding to every bottle of base wine 24 g/L of sucrose, preadapted yeast, and the bentonite necessary for each treatment. Hence, the bottles of the base wines for the treatments, 50% and 75% (S50 and S75) were spiked with the dosage of hydrated 5% (m/v) bentonite needed to complete their stabilization; this was 8.5 and 4.25 g/hL, respectively. Moreover, 3 g/hL bentonite was added to all the bottles to facilitate riddling, avoid differences due to technological reasons, and to be able to assign the results and effects to the bentonite used as a clarifying agent. Fifteen days later, the second fermentation was complete, and samples were taken  (STAGE 2) , and sparkling wines were finished  (STAGE 3)  . After 9STAGE 3) . The resThe standard compounds employed in this study for the identification and quantification, i.e., ethyl butyrate, isoamyl acetate, ethyl hexanoate, hexyl acetate, ethyl lactate, ethyl octanoate, isoamyl hexanoate, ethyl nonanoate, methyl decanoate, ethyl decanoate, isoamyl octanoate, diethyl succinate, β-phenethyl acetate, isoamyl decanoate, isobutanol, isoamyl alcohol, hexanol, E-3-hexenol, phenylethyl alcohol, linalool, α-terpineol, citronellol, E-nerolidol, hexanoic acid, octanoic acid, and decanoic acid, were supplied by Sigma-Aldrich (Germany). Sodium chloride and 4-methyl-2-pentanol  were purchased from Merck .https://webbook.nist.gov/ (accessed on 20 November 2020)). LRIs were calculated using the retention times of n-alkanes (C6–C30) under identical conditions for each analysis temperature program. All data were expressed as concentrations (μg/L) obtained from calibration curves using the reference standards (relative area vs. concentration), except in the case of C13 norisoprenoids, for which the data were expressed as relative areas. The relative area was calculated by dividing the peak area of the major ion of each compound by the peak area of the major ion of the internal standard.Volatile compounds were extracted using headspace solid phase microextraction (HS-SPME), as described by Ubeda et al. . For the2 entry was filled with 100 mL of the sample, and a constant flow of CO2 (10 L/h) was passed through the sample at a constant temperature of 16 °C. The parameters measured were HM, which is the maximum height reached by the foam and represents the foamability, and HS, which is the stable height of the foam that represents the ability of the wine to produce stable foam/persistence of the foam collar [Foam properties were measured using the Mosalux procedure ,26. To cm collar . These a2 integration. The last attribute provides information about foam aggressiveness in the mouth. For each evaluation, 50 mL of sparkling wine at 8 °C was served in each glass . The selected attributes were indicated on a tasting card, and panelists were asked to rank each descriptor on a 15 cm unstructured scale (from unnoticeable to very strong).Samples of sparkling wines after 9 months of aging were employed for sensory analysis: A50, A75, and A100 . They were evaluated by an expert panel of 17 tasters who are professional oenologists from the sparkling wine industry in Chile . The attributes selected were aromatic intensity, foamability, foam stability, and COwww.infostat.com.ar) was used for data analysis. The means were compared using ANOVA and a post hoc (Tukey test) (α = 0.05). Principal component analysis (PCA) was performed using IBM SPSS Statistics 26 software . Sensory analysis data were processed using PanelCheck V1.4.2 .The InfoStat 2017p software . In the case of the addition of 50% of the dosage of bentonite in the tirage (S50), the resulting sparkling wines presented a significantly lower ester amount than B50 wines; however, S75 and S100 revealed an increase in the total amount of these compounds, which was probably due to the esters formed during the second fermentation. The increase in the ethyl butyrate and isoamyl acetate contents of S75 and S100 was statistically significant . The losFinally, as expected, the aging on lees produced a significant decrease in the total amount of esters (Stage 3), which was probably due to acid hydrolysis or even adsorption on the lees ,30,31. AUnexpectedly, the amounts of ethyl lactate and isoamyl decanoate increased in wine A50 from the end of the second fermentation until the end of 9 months of bottle aging with lees.Neither the first nor the second addition of bentonite produced significant differences in the total amount of alcohols in base wines at stage 1  or sparkling wines at stage 2  . LikewisThe terpenes group presented the same behavior as alcohols, without significant changes between the different treatments after the first and second addition of bentonite and between stages 1 and 2. The significant changes occurred after the aging period; the linalool content decreased and the citronellol content increased in all the sparkling wines studied, whereas the nerolidol content increased in A100. It is expected that during aging on lees, the effect of β-glucosidase enzyme activity releases the aglycone (odoriferous molecule) from the sugar in the volatile compounds present in their glycosidic form in the wine, thereby increasing their presence in the matrix during aging . HoweverSimilar to alcohols and terpenes, acids showed no significant differences between stages 1 and 2 and among the different treatments. Again, a decrease in the contents of all the acids determined in A50 and A75 was observed only after the aging period. In the case of A100, only the decanoic acid content significantly diminished .It is well known that some norisoprenoids such as 1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN)and vitispiranes are aging markers ,34. ThesThe diversity of the effects experienced by the different volatile compounds after bentonite treatment may be explained by the fact that only a few odor-active compounds are directly adsorbed by bentonite, most of which are removed as an indirect effect of deproteinization . DependiIn general, the most effective treatment was the application of a 100% dosage of bentonite to the base wine before the second fermentation. These results agree with those obtained by several authors, indicating that bentonite fining could have a lower impact on the aroma quality when used before fermentation, i.e., when the fermentative aroma is yet to be produced .Foaming properties of sparkling wines after 9 months on lees  were measured using the Mosalux methodology. Measurements taken using this methodology are quite heterogeneous; in this study, one measurement was taken for each bottle of the triplicates . Therefore, heterogenicity did not allow us to obtain significant differences among the different treatments . InsteadA simple descriptive sensory analysis was performed with sparkling wines to assess whether their chemical and physical properties were perceived. Visual parameters were strongly influenced by the distribution of the bentonite dosages during the production process. Hence, A75 and A100 showed significantly higher foamability and persistence of the crown than A50 . The per2 integration; however, it seemed that as the quantity of bentonite added prior to aging time increased, the integration of CO2 perceived by the panelists decreased. This parameter affects the dissolved carbon dioxide in the wine and directly influences the frequency of bubble formation in the glass, the growth rate of rising bubbles, the mouthfeel, and the aromatic perception [Finally, the samples did not present significant differences in in-mouth COrception .Two different PCAs including all the volatile compounds, and the total sum of every group were performed as shown in The results of this study showed that the distribution of the dosage of bentonite needed for stabilization of the base wine before and the tirage significantly influences the volatile compounds profile and sensory perception of the sparkling wines. Our results suggest that the amount of bentonite added as a fining agent in the tirage causes greater effects during treatments than the addition of this agent in the base wine. The addition of 100% of the bentonite dosage to the base wine gives rise to wines with higher amounts of volatile compounds; however, the distribution of 75% of the bentonite before the tirage and 25% during it results in a diminution of higher alcohols contents, enhancing the perceived aromatic intensity. From a sensorial point of view, the addition of 50% of the bentonite dosage during the tirage has a negative effect on the foam and aromatic properties. These results reflect the state of the current procedures applied in most wineries; however, knowledge of the effects of the distribution of the dosage could help winemakers with highly unstable wines ensure protein stabilization (because the volatile profile seems to be mostly unaffected) or even enhance the aromatic intensity and complexity of sparkling wines.


In the light of these applications, a colloidal analysis of Al2O3-H2O was made. Therefore, a colloidal model is considered and treated numerically. The significant influences of multiple parameters on thermal enhancement, entropy generation and Bejan parameter are examined. From the presented colloidal model, it is explored that Al2O3-H2O is better for the applications of mechanical and applied thermal engineering. Moreover, fraction factor tiny particles are significant parameters which enhanced the thermal capability of the Al2O3-H2O suspension.Thermal enhancement and irreversible phenomena in colloidal suspension (Al The heat-transfer inspection in nanofluids gained much interest from the researchers, engineers, industrialist and scientists. Nanofluids have potential heat-transfer characteristics that make them superior to regular liquids, and researchers, engineers and scientists prefer the applications of nanofluids for industrial and technological zones. When the regular liquids are used in the aforementioned areas, these fluids fail to accomplish the production processes for many industrial items which need large heat transfer. Therefore, in such a scenario, the nanofluids are reliable fluids to use that provide the required heat to accomplish the production of different items in the industries. Nanofluids are a potential field of interest, and the researchers focused their attention on the uses of these rich heat-transfer fluids in different areas and in daily life, as well. These fluids are positively used in coolant car radiators, medical sciences, drugs, electronics, the production of computer chips, civil engineering, biotechnology, electrical engineering and in many other industries. 3O4) and oxides of different metals  in the conventional, such that aforementioned nanoparticles and conventional liquid are thermally in equilibrium. The reason for the high heat-transfer characteristics of nanofluids is the thermal conductivity that made these fluids superior from regular liquids . The large thermal conductivity of the aforementioned metals and their oxides enhances the thermal conductivity of the resultant mixture that is called nanofluid. Therefore, the nanofluids comprising the high thermal-conductivity characteristics have high heat-transfer characteristics and are better for industrial and technological purposes. It is a fact that the heat transportation in the conventional liquids can be enhanced by adding the tiny (nano-sized) particles of various metals , carbon nanotubes  and single-wall carbon nanotubes (SWCNTs)), ferromagnetic  was developed by Hamilton . The par2O/Al2O3, the model is reported in [Patel et al.  proposedorted in . The freorted in . The resThe flow nanofluid by using water as host liquid between parallel disks is reported in . For fas2O nanofluid between parallel disks. For mathematical treatment of the nanofluid model, they adopted a Galerkin-based homotopy analysis method and reported the results for the flow characteristics. The analysis of variable fluid characteristics in flow squeezed between parallel disks by incorporating the influences of magnetic field was detected in [Ahmed et al.  detectedected in . Ahmed eected in  detectedThe effective thermal conductivity is a key ingredient for the improvement of thermal transport in the analysis of nanofluids. Therefore, numerous thermal conductivity correlations can be achieved by incorporating different factors, like tiny particles geometries, temperature factor, molecular diameter, tiny particles diameter and freezing temperature ,7,8,22. The entropy generation is one of the rich topics in the field of fluid dynamics. The amount of entropy due to irreversible processes is termed as entropy production. These are thermal and mass transport processes, fluid flow, movement of the bodies, mixture of nanomaterials and liquids, and heat exchange and in thermal mechanics, like air conditioners, power plants, refrigerators, heat engines, etc. On the basis of entropy production, another significant physical-quantity defined termed as Bejan number in the scientific domain of fluid dynamics. The Bejan physical describes the ratio between thermal transport irreversibility to the total irreversibility produced due to the thermal transport and friction between the fluid particles. Therefore, entropy production and the Bejan number are extensively used in the field of fluid dynamics and aforementioned industrial applications. The coupling of entropy production and Bejan effects with numerous nanofluid models is very significant, and many researchers and engineers focus on the analysis of such nanofluid models.From the literature study, we detected that the thermal enhancement and the behavior of Bejan effects, by considering the thermal radiations and the diameters of nanoparticles and molecules in dissipative nanofluid between parallel disks, have been not examined so far. Therefore, this study was made to conduct this important research.2O3-H2O colloidal mixture. These are stretching parameters , rotational parameter 2O3-H2O colloidal mixture are painted. The impacts of fraction factor of the tiny particles of Al2O3 are discussed, and we found fascinating alterations in the effective characteristics like density, heat capacitance and thermal conductivity of the nanofluid.The behavior of flow characteristics significantly alters for multiple parameters embedded in the flow model Al1 on the axial (F) and radial velocities (F’) of Al2O3-H2O colloidal mixture are painted in 2O3-H2O adjacent to the disk surface drag and stretching of the disk provides the extra momentum to the molecules consequently the momentum rises, leading to abrupt changes in the velocity, F. The maximal increment in the velocity is observed in the region The influences of stretching parameter A2O3-H2O velocity for multiple values of Reynolds number. These effects are painted in 1 parameters. It is detected that the axial and radial velocity showed reverse trends. The axial velocity, F, near the lower end enhances quickly and exhibits almost minimal behavior, if examined near the upper end. The decreasing trend in the radial velocity of Al2O3-H2O nanofluid is observed. In the vicinity of the middle portion of the disks, maximal increasing trends are observed.The Reynolds number, which is the relationship between the inertial and viscous forces, is a significant flow parameter in the study of fluid dynamics. 2O3-H2O nanofluid for stretching parameters and the Reynolds number.This subsection comprises the alterations in the tangential velocity G(η) for Al1 and A2) of the upper and lower disks are painted in 2O3-H2O nanofluid and the disks rotate together and in the same time the disks stretched. Due to stretching and rotation of the disks, the movement of the fluid particles enhance, and the momentum of the Al2O3-H2O nanofluid increases, and as a result, the tangential velocity also increases. Near the lower and upper end, these alterations are quite slow; these are due to the frictional force between the fluid particles and the disks surface. Similarly, 3 and the Reynolds number. It is inspected that G(η) upturns for both A3 and Re. The quick alterations in the tangential velocity of Al2O3-H2O nanofluid are examined for A3 near the upper end.The influences of stretching properties . Similarly, increasing trends for β(η) are pointed by altering Br number. The nanofluids have potential heat-transportation capability in comparison with regular liquid. Therefore, these fluids are better for industrial and technological purposes. The behavior of thermal transport β(η) against Br and the Eckert number is painted in Entropy and the phenomena of Bejan effects are very significant in the research area of fluid mechanics. This phenomenon has a wide class of uses in moving bodies, thermal machines, heat exchange, thermal characteristics in nanofluids and irreversible thermodynamics. The entropy production is described as the entropy during irreversible processes. The influences of multiple parameters related to entropy production and Bejan effects are elaborated in 3 and Re abruptly in the middle of the disks, where for the more radiative colloidal mixture Al2O3-H2O, prominent alterations in the Bejan parameter are examined near both ends. These influences are elaborated in 2, Br, A1 and A, the Bejan effects drop between the disks.It is explored that the Bejan parameter enhances for growing A2O3-H2O, the entropy Ng(η) enhances abruptly. Physically, it means that, due to more radiative Al2O3-H2O, internal energy source enhances, allowing the large momentum to the Al2O3-H2O molecules and therefore diffusion phenomena among the tiny particles upturns and Ng(η) increases. Similarly, for ws, α, A and Br, the entropy enhances. For stretching quantity A1, the abrupt increasing pattern of Ng(η) is examined. The physical reason behind this is the stretching of the lower disk. Due to stretching of the lower end, the Al2O3-H2O molecules are disturbed, allowing for the abrupt increment in the Ng(η). For more dissipative Al2O3-H2O mixture, dual pattern of Ng(η) is detected. Near the lower end Ng(η) declines for stronger dissipative parameter and also for Re and A3, Ng(η) declines quickly.The entropy production against imposed radiation parameter is depicted in nf), density (ρnf) and heat capacity (ρcp)nf of nanofluid play an important role in the flow regimes. Therefore, p)nf are pointed for multiple values of In the colloidal studies, the fraction factor, 1 and A2) and fraction factor 2), the surface stresses rapidly decline at the lower end, while these trends are slow at the upper disk because the upper disk being stretched allows the fluid particles at the disk surface. A significant transport of the shear stresses is pointed at the upper disk for Re. The surface shear stresses due to varying flow quantities are important from engineering point of view. The behavior of surface shear stresses due to stretching of the lower and upper disks  and nanoparticles AlThe flow is viscous and incompressible;2O is taken as host liquid;H2O3 is taken;The nanomaterial of AlThe host liquid and nanomaterial are thermally in equilibrium;There is no slip condition;Thermal radiations are imposed on the nanofluid flow.The colloidal flow of nanofluid by considering the nanomaterial and molecular diameters is taken between two parallel rotating disks. The following assumptions are made for the model under consideration:On the basis of above highlighted assumptions, the dimensional model which governs the nanofluid flow between parallel disks takes the following form :(1)∂u*∂rThe flow conditions at the boundaries of the disks (lower and upper) are as follows.u*, v* and w* are the velocity components; h is the height between the disks; T1 and T2 are the temperature at the lower and upper end, respectively; For nondimensionalization of model, it is significant to define the invertible transformations. Therefore, the following transformations are defined that support the model:nf stands for nanofluid; and fk and pk are the thermal conductivities of the host liquid and tiny particles, respectively. Further, bRe) appearing due to that effects of Brownian motion is described by the following formula:The nanofluids are reliable for better thermal transport due to their effective characteristics, such as effective density, heat capacity, dynamic viscosity and thermal conductivity. Therefore, the following models are incorporated :(9)ρnf*=bu* stands for the velocity of Brownian motion in Equation (13) and is expressed by the following mathematical relation:Furthermore, bk, and its particular value is equal to f and mathematically expressed in the following way [The Stefan Boltzmann coefficient in Equation (14) is represented by M* and N* stand for the molecular weight and Avogadro number, respectively. Further, fd is computed in the following manner:In Equation (15), Now, thermophysical characteristics of aforementioned tiny particles and host liquid by comprising the influences of nanoparticles and molecular diameters are described as The nondimensional analysis of the particular nanofluid model is carried out by means of feasible defined invertible transformations. By plugging the similarity transformations embedded in Equation (8) and required partial derivatives in Equations (1)–(5), the following dimensionless nanofluid model comprising the effects of nanoparticles and molecular diameter is attained:By means of invertible transformations, the dimensional conditions at the lower and upper disks reduced in the following form:Further, the expression for pressure is calculated as follows.The self-similar parameters appeared in the dimensionless model are described by the following mathematical formulas:The wall shear stresses attained significant importance in various technological and engineering areas. For the model of nanofluid under consideration, the wall shear stresses in dimensional form are expressed in the following mathematical formulas:The total shear stresses at the upper and lower are given by the following mathematical relation:By plugging the similarity transformations and after simplification, the following relations for the shear stresses at the upper and lower disks are obtained:The mathematical relation for entropy generation is described as follows:By plugging the viscous dissipative term in Equation (28), the following relation is attained:After this, plugging the similarity transformations and suitable partial differentiation, the following self-similar form is obtained:Moreover, the mathematical expression for the Bejan number is as follows:The dimensionless physical parameters appear in Equations (31) and (32), as follows:The nanofluid model under consideration, comprising the influences of freezing temperature, molecular and nanomaterials diameters, is very tedious, highly nonlinear and coupled system of ordinary differential equations. It is not possible to find the exact solutions for such a nanofluid model. Thus, the numerical techniques are best to tackle the model of such nature. Therefore, Runge Kutta (RK) numerical technique with coupling shooting technique ,25 was a2O3-H2O by incorporating the influences of nanomaterials diameter, viscous dissipation and entropy generation for thermal enhancement is of much interest and has gained the popularity among the engineer and researcher communities. Specifically, the analysis of entropy generation in colloidal fluids is significant from the point of view of heat engines, air conditioners and refrigeration. Therefore, the study is presented in light of the aforementioned applications. From the presented work, the following is detected:2O3-H2O upturns due to the stretching of lower end over The axial velocity r and is detected that more dissipative Al2O3-H2O colloidal fluid is better for industrial and engineering applications where huge amount of heat transfer is required to acquire the process of production.Thermal transport enhances for B2O3-H2O for multiple values of The entropy generation due to an irreversible process such as fluid flow and heat transfer enhances in Al2O3-H2O enhances for strong thermal radiations phenomena.The effects on the colloidal flow of Al2O3-H2O.The effective characteristics of the colloidal fluid enhances for fraction factor 2O3-H2O particles drag at the surface are detected.Due to stronger fraction factor, The analysis of radiative colloidal fluid AlFuture Insights: The modern world is moving toward the applications of nanotechnology by considering numerous physical phenomenon, almost from every aspect of life. Therefore, the analysis of Lorentz forces, resistive heating and double stratification that are extensively applied in the production industries are the topics of interest in the study of nanofluids these days.


Delamination is one of the detrimental defects in laminated composite materials that often arose due to manufacturing defects or in-service loadings . Most of the contemporary research efforts are dedicated to high-frequency guided wave and mode shape-based methods for the assessment  of delamination. This paper presents a deep learning framework for structural vibration-based assessment of delamination in smart composite laminates. A number of small-sized  inner and edge delaminations are simulated using an electromechanically coupled model of the piezo-bonded laminated composite. Healthy and delaminated structures are stimulated with random loads and the corresponding transient responses are transformed into spectrograms using optimal values of window size, overlapping rate, window type, and fast Fourier transform (FFT) resolution. A convolutional neural network (CNN) is designed to automatically extract discriminative features from the vibration-based spectrograms and use those to distinguish the intact and delaminated cases of the smart composite laminate. The proposed architecture of the convolutional neural network showed a training accuracy of 99.9%, validation accuracy of 97.1%, and test accuracy of 94.5% on an unseen data set. The testing confusion chart of the pre-trained convolutional neural network revealed interesting results regarding the severity and detectability for the in-plane and through the thickness scenarios of delamination. Composite materials are continuously replacing conventional metallic materials in a variety of industries  due to their lightweight, high specific strength, high specific stiffness, and design flexibility. Besides, composite materials do not present the typical corrosion problems of conventional metallic materials ,2,3,4. H0 mode of the Lamb wave. The increase in temperature further decreased the propagation velocity and amplitudes of A0 mode. Temperature correction factors were proposed to minimize the effect variable temperature conditions on structural health monitoring strategies for composite materials. Kundu et al. [0A and 0S, 0A mode showed more sensitivity to the damage severity than 0S. Li et al. [The anisotropic material properties and complex microstructure make the damage assessment of composite materials more challenging than metallic materials. Consequently, the damage assessment of laminated composite is an active research area where continuous efforts are made to find cost-effective techniques for the detection, quantification, and localization of delamination in these materials ,14,15,16u et al.  proposedu et al.  presenteu et al.  used a lu et al.  proposedu et al.  studied u et al.  investigi et al.  developei et al.  studied In general, the vibratory responses in the fundamental modes  carry information about the presence of damage  in the structure, whereas information on the location of damage is captured by high-frequency Lamb waves and acoustic emission . In the From the contemporary research on delamination in laminated composites, it can be found that most of the research efforts are dedicated to the use of higher-frequency guided waves , acoustic emission/acoustic ultrasonic, and mode shape curvatures for the detection, quantification, and localization of delamination ,47,48,49x, y, z) as follows [The accurate description of the structural deformation of a laminated composite with surface bonded or embedded piezoelectric sensors and actuators requires a coupled electromechanical formulation. The kinematics of the smart structure with single and multiple discrete delaminations is developed based on improved layerwise theory , whereas follows :(1)Uik(xaminates . In the p-th piezoelectric layer is given by Equation (2) [p-th piezoelectric layers, respectively. The symbol The electric potential field of the piezoelectric sensors and actuators is assumed to have a cubic distribution along the thickness direction. The mathematical description of the potential field for the tion (2) :(2)ϕp are considered for the converse and direct piezoelectric effects. The constitutive relations of piezoelectric actuator and sensor are shown by Equation (3) :(3)σij=cA finite element method is adopted to combine the displacement and potential fields for a 4-noded plate element. The primary in-plane unknowns (tion (5) :(5), the displacement unknowns can be described in terms of nodal unknowns by using the matrix notation as follows:In terms of the displacement field (Equation (1)) and electric potential field (Equation (2)), the elemental displacement field The electromechanically coupled equation of motion is obtained by substituting the stress, strain, and electric displacement components in Equation (9), and is shown in matrix form by Equation (10) :(10)Md¨uFor numerical solution, the mathematical model of Equation (10) is modified to Equation (11) by applying matrix condensation:The developed numerical model was implemented in MATLAB. Newmark’s time integration algorithm  was empl4s). One piezoelectric actuator and three piezoelectric sensors are attached to the surface of the smart plate as shown in the schematic of The mathematical formulation of Herein, the piezoelectric actuator is attached at the off-center position along the width direction so that mix-vibrating modes  of the smart plate could be stimulated. The piezoelectric actuator and sensors are made of the same materials. AM, BM, and CM denote the inner delaminations, whereas AL, AU, BL, BU, CL, and CU refer to the cases of edge delaminations. The inner and edge delaminations could occur at three different interfaces of 1D (mid-plane), 4D, and 7D through-the-thickness of the smart plate. The in-plane delaminations combined with through-the-thickness interface are named by adding the respective interface number with the name of the in-plane location. For example, AL1 means the presence of delamination at the AL in-plane location and at the 1D interface. The smart plate without any defect is referred to as the ‘Healthy (H)’ case. The nine in-plane delaminations combined with three options of through-the-thickness interfaces add up to 27 cases of delaminations in the smart plate. In AL1 to the 5 random loadings as measured by sensor I, whereas H, AL1, AM1, and AU1 to one of the random inputs as measured by sensor I.In the FEM model of the smart plate, the host laminate and the piezoelectric patches were discretized with four-node plate elements. The healthy and delaminated smart plates were excited into random low-frequency vibration through a set of 1000 random harmonic voltages applied through the piezoelectric actuator and the corresponding responses were measured through the piezoelectric sensors. AL1). On the other hand, the variations caused by different damage cases  are commonly used for the detection of delamination in the interlaminar regions of composite materials. However, model parameters have been mostly used for the detection of delamination and limited research effort can be found on the use of variation in modal parameters for the detection, quantification, and localization of delamination. Besides, monitoring variations in the modal damping and measurement of vibration mode shapes for delamination detection are challenging tasks, especially in practical experiments. In addition, the variations of the natural frequencies usually reflect the effect of large size delamination, and smaller delamination may not show any noticeable variation in the natural frequencies. Although, from AL1, AL2, AL3, AM1, etc.). Deep learning offers a natural solution to the current problem due to its capability to automatically extract discriminative features from the input images [The frequency spectrums in t images . Figure spectrogram function in Matlab. The spectrogram function allows for controlling the time and frequency resolution of the spectrograms by adjusting the variables of window size, type of window function , fast Fourier transform (FFT) resolution, and the overlapping rate. In general, the FFT resolution was observed to affect the spectral resolution of the vibration spectrograms and the computational time of the short time Fourier transform. In the current work, the FFT resolutions of 10, 102, 104, and 108 were considered for initial assessment and the spectrogram with FFT resolution of 104 and 108 showed good spectral resolution. Although no significant difference was observed in the resolution of spectrograms with 104 and 108 FFT resolutions, the computational time for 108 FFT resolution was about 3 times longer than for 104 FFT resolution. Hence, an FFT resolution of 104 was selected. The Hamming window function was selected due to its better performance in the high-frequency band compared with Hann and Blackman window functions. To prevent Picket fence error and avoid loss of information at the beginning and end of the signals [Herein, the response from the three piezoelectric sensors is transformed into time-frequency spectral images using the  signals , a 50% oThe original size of each spectrogram was 768 × 512 × 3 (width × height × number of channels) with the pixel values between 0 and 255. To reduce the computation cost of the deep learning algorithm and remove the divergence from the pixel values, each one of the three spectrograms was reduced to 256 × 256 × 3 (width × height × number of channels) and normalized to a pixel value between 0 and 1 as shown by The goal of normalization was to change the pixel values of the spectrograms to a common scale for the healthy and delaminated structures without distorting the differences in the range of values. In addition, normalization reduced the influence of larger variance in the pixel values on the classification results of the deep learning algorithm. Details of the CNN-based classifier, interpretation of the training and validation process, and testing of the pre-trained network are discussed in the next section.H) and 27 cases of inner and edge delaminations in the smart laminated composite plate. Based on the applied random harmonic loads, each one of the 28 cases is comprised of 1000 instances. From the discussion in The data set of vibration-based spectrograms consisted of one healthy case . In the network, six model blocks were used to automatically extract discriminative features from the spectrograms. Each model block was comprised of a 2D convolution layer with a filter/kernel of size 3 × 3, batch normalization, Leaky ReLU ,56 as a The proposed architecture of the CNN was trained through a 10-fold cross-validation technique. The network showed an overall all training accuracy of 99.9% and validation accuracy of 97.1%. The high validation accuracy showed that the network had not overfitted the training data.To evaluate the performance of the trained network, the pre-trained network was tested with 2800 spectrograms that were not used during the training and validation process. The pre-trained network showed a predictive test accuracy of 94.5% and The classifier has distinguished the healthy case from the delaminated cases with 100% accuracy.The more severe cases of delaminations (the one that occurs at the mid-plane interface) have been identified with 95%~100% accuracy.AM, BM, and CM) from the edge delaminations  with 90%~100% accuracy.The pre-trained network can distinguish the inner delamination (CL7 (66%) and CM7 (68%). In case of CL7, the misclassification results are 2% as CL4 , 12% as CM7 , 5% as CM4 , 2% as CU7 , 12% as BL7 , and 1% as BM4 . Herein, major misclassification is due to confusion between delaminations at the less severe interface along the thickness i.e., 7D. Same is the case for misclassifications of CM7.The major loss of accuracy is due confusion between the least severe cases of delaminations . More specifically, the smallest accuracy has been observed for Herein, the labels in the first column denote the ground truth or actual classes, the topmost row shows the labels predicted by the pre-trained convolutional neural network, the numbers on the main diagonal represent the percentage of correctly classified instances, and the off-diagonal shows the percentage of incorrectly classified instances. It is worth noting that delamination at the mid-plane interface shows more noticeable effects in terms of stiffness change and dynamic response characteristics than delamination of the same size near the free surfaces (away from mid-plane) ,59. In aA, B, C) and through-the-thickness interface  of delamination, the classification accuracy is averaged according to the in-plane location and through-the-thickness interface as shown by The pre-trained CNN model classified the healthy and delaminated smart composite laminates with a classification accuracy of 94.5%. To get an idea of the classification performance regarding the in-plane location  are difficult to detect compared with the edge delaminations . Owing to the boundary condition of inner and edge delaminations, the result is consistent with the physics of the problem. In addition, delaminations that occur near the free end are difficult to detect than the one that occurs near the fixed end. This might be due to the high strain near the fixed end or proximity of sensors to the delaminations near the fixed end or both [For the in-plane location of delamination a, it is  or both . From FiContemporary research on delamination assessment  in laminated composites focuses mainly on the use of high-frequency guided-waves , acoustic emission/ultrasonic, and mode shape curvatures ,62,63,64This paper proposed a deep learning framework for the assessment of delamination in smart composite laminates using low-frequency structural vibration responses. The initial assessment of transient responses revealed that multifarious excitations caused more variance in the response behavior than the variance caused by delamination in the structure. A convolutional neural network (CNN) was designed to automatically extract discriminative features from the vibration-based spectrograms and use those features to classify the healthy and delaminated smart composite laminates. The proposed architecture of the CNN showed a training accuracy of 99.9%, a validation accuracy of 97.1%, and a test accuracy of 94.5%. The test confusion chart of the pre-trained CNN revealed that the proposed approach not only distinguished the healthy and delaminated smart composite laminates with 100% accuracy, but also identified the more severe cases of delamination with 95%~100% accuracy. Furthermore, it was found that the detectability of delamination becomes difficult as the in-plane location of delamination is moved from the clamped end of the plate towards the free end and when through-the-thickness interfaces are moved from the mid-plane interface towards the free surfaces. Results of the proposed approach were found to be consistent with the physics of the problem. The proposed approach does not require the labor-intensive process of hand-crafted discriminative features and requires only low-frequency structural vibration response for the global and local assessment of delamination in smart composite laminates. In the future, the proposed approach would be extended to assess multiple damages  in cross-paly and angle-ply smart composite laminates. In addition, the proposed deep learning strategy could be used to bridge the gap between simulations, lab scale experiments, and large-scale structures of composite materials via transfer learning or data augmentation.


The nano-TiO2 coating materials for both road surface and roadside were prepared by using anatase nano-TiO2, activated carbon powder, silane coupling agent and deionized water. The impact of varying amounts of coating material and silane coupling agent were evaluated. The road environment of NOx degradation was simulated by the photocatalytic test system designed by the research team. For the road surface coating, the photocatalytic degradation experiments of NO under different radiation intensities were carried out. The results show that the material has good photocatalytic degradation performance, and the proper amount of silane coupling agent can enhance the bonding performance of the material and asphalt mixture. For the roadside coating, sodium dodecylbenzene sulfonate was selected as the surfactant to carry out the photocatalytic degradation experiment of NO2 with different dosages of surfactant. The results showed that when the mass ratio of nano-TiO2 and surfactant was about 1:2, the catalytic degradation effect of the material was the best.The NO Thefunction .2 as a catalyst to electrolyze water in 1972 [2 photocatalyst has been increasing gradually. In 1984, Brown and Darwin evaluated the effect of methyl orange additive on the photocatalytic activity of TiO2 [2O5 on the activity of TiO2 [2 was used to oxidize carbon monoxide (CO) and nitrogen oxides (NOx), the reactive formation was nitrates and carbon dioxide (CO2), and it also found that TiO2 can recover its photocatalytic activity after surface cleaning [Since Fujishima and Honda used TiO in 1972 , the res of TiO2 . Cui et 2 in the construction of cement concrete pavement. The Antwerp City Park in Belgium constructed a sidewalk of about 10,000 m2 with cement concrete bricks containing nano-TiO2 [2 was often used as a stone coating for self-cleaning and biocidal purposes [2 mixed into porous concrete on rainwater runoff pollution [2 in different environments of cement concrete pavement containing TiO2 [2 and TiO2-SiO2 coating cement [2 particles [Around the end of the 20th century, many places around the world, including Chiba of Japan in 1999 , have apano-TiO2 . In the purposes ,13. Lianollution . Sikkemaing TiO2 . Mendozag cement . He et aarticles .2 photocatalytic on cement concrete pavement, there is a lot of research on nano-TiO2 in the degradation of air pollution in asphalt pavement too, as more than 90% of the world’s new highway construction is asphalt pavement [2 to asphalt pavement materials in the forms of coating and mixing [2 particles and ZnO particles can make asphalt softer and have a better short-term aging resistance effect. Li et al. added nano materials to asphalt mixture and found that nano materials can enhance the viscoelasticity, high temperature stability, aging resistance and fatigue resistance of asphalt mixture [2 in the photocatalytic coating and the best spray content of the photocatalytic coating on the flat surface were obtained. Qian et al. evaluated the effect of SBS modified asphalt with different content of nano-TiO2 on the degradation of nitrogen and oxygen and also evaluated the effect of nano-TiO2 on the rheological properties of asphalt pavement [2 coating on asphalt pavement and a construction method of TiO2 modified aggregate coating photocatalytic air purification asphalt pavement [x degradation rate. da Rocha Segundo et al. used bulk incorporation and spray methods to produce asphalt mixture with photocatalytic function, and evaluated the influence of traffic and weathering wear on photocatalytic efficiency and mechanical properties [2 as a photocatalyst coating on asphalt pavement on the degradation of automobile exhaust and evaluated the photocatalysis and durability of N-doped TiO2 photocatalytic asphalt pavement materials [Besides the above research and the of nano-TiOpavement ,19. Tan d mixing . Segundod mixing . It was  mixture . Wang et mixture . Based opavement . Wang, epavement ,26. The operties . Chen etaterials .2 on the wall surface of three buildings and found that the coating wall can greatly reduce the concentration of NOx compared with ordinary walls [2 coating on residential glass and found that it had a certain effect on air purification [2 and WO3/TiO2 coating on the urban green infrastructure with different structural configurations  for NOx purification [2 on the catalysis of harmful gases [In 2008, French researchers sprayed nano-TiOry walls . Babaizafication . Mendozafication . Sun et ul gases . Shen etul gases , and fou2, the temperature, and humidity on the catalytic degradation performance. However, studies on the impact of different amounts of surfactant and different levels of UV radiation intensity on the photocatalytic effect are few. Moreover, the NOx concentration studied is quite different from than that in the actual road environment for many indoor experiments.It can be found from the literature review that most of the current research was mainly focused on the influence of the incorporation way, the amount of nano-TiOx concentration in different periods of road environment in typical sections of Guangzhou (China), the photocatalytic degradation tests were conducted under different levels of UV radiation intensity using the self-developed photocatalytic environmental chamber, the degradation performance of the designed road surface coating and the roadside coating was tested. Additionally, the impact of different surfactant amounts was evaluated. Based on the field monitoring of NOx concentration of the road surface is high, which could make the TiO2 degrade more NOx, so the road surface coating styles were evaluated. However, the road surface coating could not be sustained because it may rubbed off because of tire rotation, also the coating could impact the skid resistance, so the roadside coating style was evaluated.The purpose was to evaluate the road surface and roadside coating styles, for the following reasons: because automobile exhaust is discharged closely to the road surface, and the NOThe experiment design and research flowchart are shown in 2  was used, and the technical indicators were shown in In this research, the VK-TA18 nano-TiO3 [2 was measured at room temperature of 13 °C. The procedures of measuring the nano-TiO2 sizes were as below: firstly, the nanoparticles were dispersed in anhydrous ethanol, and then put in the ultrasonic cleaner for dispersion for one hour . The particle size analysis results shown that the minimum particle diameter is 71.0 nm, the mean particle diameter is 152.3 nm, and the median particle diameter is 139.9 nm. A scanning electron microscope (SEM) was also used to observe the nano particles and it found that only the size larger than 5 μm clumps can be observed, which indicated that the nano particles were agglomerated together during the transport and storage process, and which could affect the photocatalytic efficiency [The density was measured according to the Test Methods of Aggregate for Highway Engineering (China) and the measured result was about 3.132 g/cm3 . The sizficiency .In order to improve the degradation efficiency of photocatalytic reaction, the active carbon powder of finer than 200 mesh was selected as the absorbent. With its huge specific surface area, the active carbon powder can greatly increase the contact area between photocatalyst and exhaust gas .2 powder and asphalt mixture for road surface coating. Sodium dodecylbenzene sulfonate was used as the surface modifier for the roadside coating, and the deionized water was selected as the solvent.There are two different coating applications that were evaluated in this research, which including the road surface coating and the roadside coating. In order to prevent the coating material peeled off and increase the durability of the coating, the KH-550 silane coupling agent produced by Nanjing Pinning was used as the surface modifier which could enhance the adhesion between nano-TiO2 and 0.2 g of activated carbon powder were mixed together by mechanical agitation, and 0.1 g of dispersant was added into 10 g deionized water to disperse the mixed powder. In order to evaluate the influence of different surface modifiers on the photocatalytic properties of TiO2, five different contents  of KH-550 silane coupling agents were added into the solution, and then the five different road surface coating materials were dispersed with ultrasonic cleaner for 2 h. And then the coating material was spray coated at an amount of 250 g/m2 on the surface of the asphalt pavement specimens.The road surface coating material was prepared below: firstly, 0.2 g of anatase nano-TiO2 and 0.1 g of dispersant were added into 10 g of absolute ethanol for disperse, and three different amount  of sodium dodecylbenzene sulfonate were added respectively, and then three kinds of photocatalytic samples of roadside coating materials were prepared with ultrasonic cleaner by dispersing for 2 h. After the roadside coating material was prepared, the roadside coating material was coated on the surface of the sandwich plywood at dosage of 250 g/m2 through a spray method.The roadside coating material was prepared as follows: firstly, 0.2 g of anatase nano-TiO2 can be expressed in the Equations (1) to (11):The photocatalytic degradation reaction of TiOx,In which, the 2 gases used in this experiment were produced by Changzhou Jinghua Industrial Gas Company  with a purity of 99.9%. In this research, the Taiwan Luchang UVA365 ultraviolet (UV) irradiator  was used to measure UV radiation, the measurement wavelength is 365 nm, the measurement range is 0–199 W/m2, and the resolution is 1 W/m2.The NO and NOIn this research, the photocatalytic environmental chamber was developed. The system contained a UV radiation system with variable intensities and a gas detection system that is able to accurately control and determine the gas during the whole photocatalytic reaction process ,37.Structure of the test system3 as shown in 3, and the size of the UV light source slot is 50 × 18 × 16 cm3 as shown in The external dimension of the environmental chamber is 70 × 70 × 170 cm2 and N2O4 on the catalytic degradation process, and N2O4 gas analyzer was also installed in the environmental chamber.The environmental chamber has good air-tightness performance, the light source is UV-LED light tubes with ARM controller processor, which is able to provide constant current and temperature monitoring. The radiation intensity of the light source can be adjusted in the range of 0–100%. In order to evaluate the effect of the reversible reaction of NOx degradation test, the light intensity and distribution inside the photocatalytic reaction chamber should be close to the UV environment in the actual condition. The UV in the sunlight is mainly the UVA long wave band, so the LED light source selected in this test system emits UVA in order to simulate the actual sunlight condition.In the design of the NO2. The layout of the verification points are as shown in The irradiation intensity verification was also carried out for the light source, the test range was horizontally at the bottom of the chamber at the size of 300 × 150 mmWhen testing the degradation performance of asphalt pavement coating materials, the distance between the light source and the test specimen was 65 cm, and when testing the degradation performance of the roadside coating, the distance between the light source and the sandwich plywood was 70 cm. The irradiance intensity values at different irradiance distances of 65 cm and 70 cm were measured and it was found that this light source can effectively simulate the irradiance intensity of different levels of UV rays, and can be used to evaluate the intensity of UV in different regions or in different seasons.x in the test process, three typical road sections near the bus station or the traffic light intersection were selected on the main road of Guangzhou (China) for monitoring, which including the road surface under the overpass, the road in the tunnel, and the uphill section. The reason to choose those three sections is that the car usually in the low-speed or idle state, and the incomplete combustion of gasoline leads to the high concentration of exhaust pollutants.In order to determine the initial concentration of NOPoint M-12 concentration in the air during the monitoring period is shown in The measuring point M-1 is located at the bottom of the overpass. The main road is a two-way eight-lane road with large traffic flow. There is a traffic light intersection about 100 m southwest of the measuring point, and a bus station about 20 m northeast of the measuring point. The monitoring result of NO and NOPoint M-22 pollutants during the monitoring period are shown in The measurement point M-2 is located about 100 m inbound close to the end of a long tunnel with heavy traffic. The concentrations of NO and NOPoint M-32 pollutants during the monitoring period are shown in The measurement point M-3 is an open location on an uphill road with medium traffic flow. The concentrations of NO and NO2 which caused the peak of NO2. In the tunnel, due to the low oxygen concentration and the small amount of NO oxidized, the concentration of NO2 is not high, and it has been kept at low value for a long time.According to the field observation, the locations M-1 and M-3 have serious engine idling because there are a lot of buses parked near measuring point M-1, and measuring point M-3 is the uphill road section. While the measuring point M-2 has poor air circulation because it is located in the tunnel. As motor vehicle exhaust is one of the main sources of NO, the NO concentration peak was caused by the exhaust emissions because of the deceleration or idling of vehicles. After a period of time, NO emissions oxidize into NO2 concentration was chosen as the evaluation index because NO was oxidized into NO2 when it was discharged into the air. According to the monitoring results, the initial concentration of NO and NO2 for the experiment was chosen as 0.500 ± 0.010 ppm.In the degradation test of pavement surface coating, the concentration of NO was evaluated because the vehicle exhaust is near the ground, and in the degradation test of roadside coating, NO2 surface coating material or the sandwich plywood test piece coated with the roadside coating material in the environmental chamber. Then, we turned on the temperature programmable controller and set the reaction temperature of 27 ℃, the temperature was monitored through the whole process. After the reaction temperature was stable for 4 h, the desired amount of NOx was injected into the environmental chamber. Next, we recorded the NOx concentration every 5 min. After the gas concentration value is stable, we turned on the UV light and set the irradiation intensity percentage, and then continued to record the change of NOx concentration. The steps for the photocatalytic degradation test described are as follows: First, we put the asphalt mixture test specimen coated with nano-TiO2 to 400 g/m2, the TD was measured following the Specifications for Design of Highway Asphalt Pavement: JTGD50-2006 [In order to evaluate the impact of coating material on the skid resistance of asphalt pavement, the impact of coating amount on the texture depth (TD) evaluated, the coating amount was evaluated in the range of 0 g/mD50-2006 . The TD 2 and silane coupling agent of 1:1, 1:2, 1:3 and 1:5 were compared with control samples. The test result is shown in In order to evaluate the impact of different silane coupling agents on the NO degradation performance, four samples with mass ratio of nano-TiO2 surface coating material for the control group. It can be seen from 2 surface coating material was used, with the result indicating that the material can effectively degrade the NO in the road environment.There is no nano-TiO2 to silane coupling agent increased from 1:1 to 1:2, and from 1:2 to 1:3, the degradation effect of NO on the surface coating material is significantly enhanced, which shows that the increase of silane coupling agent can improve the degradation performance of the material.When the mass ratio of nano-TiO2 and silane coupling agent increases from 1:3 to 1:5, the degradation effect of NO on the surface coating material is decreased, which indicate that there is an optimum amount of silane coupling agent. The reason is that when the silane coupling agent is too much, it greatly improved the adhesion between of nano-TiO2 and asphalt mixture, and thus reduced the reaction area between nano-TiO2 and NO, thus leading to the photocatalytic activity of nano-TiO2 decreased. Therefore, during practical application, it is suggested that the optimum mass ratio of nano-TiO2 to silane coupling agent is between 1:2 and 1:3.When the mass ratio of nano-TiO2 road surface coating materials, the sample with the dosage ratio of nano-TiO2 and silane coupling agent of 1:2 was selected to conduct the recovery test. The same sample coated with the material was tested for three times consequently, and the test results are shown in In order to evaluate the photocatalytic recovery properties of nano-TiO2 was affected.It could be seen from For this reason, the deionized water was used to clean the surface of the test piece after the test, and then carry out photocatalytic degradation test after drying. The test results were shown in 2 road surface coating materials. The dosage ratio of nano-TiO2 and silane coupling agent of 1:2 was used for the evaluation. In order to simulate different UV intensity in field, adjust the light source intensity ratio to 5%, 9% and 13% when the UV radiation distance was 65 cm, which is corresponding to the UV radiation intensity of 7.9, 15.2 and 22.5 W/m2 respectively. Those three light intensities can simulate the level 2, 3 and 4 UV radiation intensities in actual conditions. The test result of different intensities on the photocatalytic degradation efficiency is shown in in As the UV radiation intensity is different at different regions or in different seasons, it is necessary to evaluate the influence of different radiation intensity on the degradation performance of nano-TiO2 coating material was enhanced with the increase of irradiation intensity of light source. When the irradiation intensity increased from 7.9 W/m2 to 15.2 W/m2, the degradation effect of the gas was not significantly improved. When the irradiation intensity increased from 15.2 W/m2 to 22.5 W/m2, the degradation effect of the NO was significantly enhanced. The UV intensity of 22.5 W/m2 is corresponding to the UV level 4, which is mostly occurred in summer or in plateau area. Therefore, the selection of different dosage according to the actual situation of the local UV intensity can achieve better applicable performance.It can be seen from The skid resistance of pavement needs to be evaluated as the coating material going to be painted on the surface layer of asphalt pavement, the textural depth (TD) was used to evaluate the influence of the coating amount on the skid resistance performance. The result of textural depth is shown in 2. When the coating amount was lower than the amount, it is considered that the sliding resistant performance of asphalt pavement still meets the driving requirements.It can be seen from In this research, the sodium dodecylbenzene sulfonate was used as surfactant to reduce the agglomeration problem of nanoparticles and improve the interfacial adhesion between the coating material and roadside plates. Three different surfactant contents, of 1:1, 1:2, and 1:3 were evaluated and compared with the control group without surfactant added. The rest result is shown in 2 roadside coating material is not used, the content of NO2 still decreased to a small certain extent which indicated that the NO2 undergo a certain degree of natural degradation by itself. When the nano-TiO2 roadside coating material was used, the degradation effect of NO2 was obviously improved, which shows that the coating material can effectively achieve the degradation of NO2 near the road.Through the comparison of three tests with different content of surfactant and the control group, it can be seen that when the nano-TiO2 to surfactant increased from 1:1 to 1:2, the degradation effect of roadside coating materials on NO2 was significantly enhanced, which shows that the increase of surfactant was helpful to improve the degradation performance of roadside coating materials. And when the mass ratio of nano-TiO2 to surfactant increased from 1:2 to 1:3, the degradation effect of roadside coating materials on NO2 is not enhanced but decreased, which indicated that there is an optimum amount of surfactant additive. The reason was that although the surfactant helps to solve the agglomeration problem of nano-TiO2, the surface activation energy of nano-TiO2 particles was also reduced which lead to the degradation of photocatalytic performance. Overall, based on the analysis, the recommended mass ratio of nano-TiO2 to sodium dodecylbenzene sulfonate was about 1:2.The result also has shown when the mass ratio of nano-TiO2 road surface and roadside coating materials under different amounts of silane coupling agent and different UV irradiation intensities were evaluated based on the field measured automobile exhaust gas concentration. Based on the analysis, the following conclusions can be drawn:x in the road environment.Both the pavement surface and the roadside coating material can effectively degrade the NO2 to silane coupling agent was between 1:2 and 1:3, and the optimum mass ratio of nano-TiO2 to sodium dodecylbenzene sulfonate was about 1:2 in the field application. Additionally, the maximum coating amount of 350 g/m2 is suggested in order to ensure the skid resistance of the pavement surface.It suggested that the optimum mass ratio of nano-TiOThe results have shown the degradation effect of coating materials on NO was gradually weakened, and that with the increasing number of experiments, and catalytic activity of the coating material can be restored after washed by deionized water.2 coating material was enhanced. Therefore, when the coating material was used in different areas, it is necessary to determine the optimum dosage according to the actual situation of the local UV intensity.With the increase of UV irradiation intensity, the degradation performance of nano-TiO2.The skid resistance of asphalt pavement is reduced with the increase of coating amount, in order to ensure enough skid resistance performance of asphalt mixture, it is suggested that the maximum coating amount is 350 g/mA photocatalytic test system with controllable environmental parameters that can simulate the whole process of the photocatalytic reaction was developed in this research. The photocatalytic degradation effect of nano-TiO


In France, Italy, Spain, and the UK, the 4 European countries that have been impacted the most by the COVID-19 emergency, lockdown was enforced 13 to 16 days after Hubei’s, when normalizing for the time when the outbreak hit 50 cases in all countries.2 This prompts the question of how many COVID-19 deaths could have been avoided during the early phase of the pandemic if containment measures in European countries had aligned with China’s lockdown.The coronavirus disease (COVID-19) epidemic has rapidly evolved into a global health emergency.1 The time-series included a small amount of days in which the number of deaths was negative. We considered these figures as missing values and replaced them, interpolating the number of deaths recorded in the previous and in the following day. We estimated the effect of the national lockdown implementing an Interrupted Time Series analysis.5 Specifically, for each country, we modeled the time-series of daily deaths (Yt) using the following quasi-Poisson regression model:2 is the time elapsed since the implementation of the lockdown (set to 0 before the lockdown); Yt is the number of new deaths at time T; α is the intercept of the model; β1 represents the trend of new cases before the lockdown; β2 is the slope change following the lockdown; and et is the error term of the model.We modeled the daily number of COVID-19 deaths in France, Italy, Spain, and the UK from January 23 to August 15. Data were downloaded from the COVID-19 Data Repository.6 Then, we created 4 separate counterfactual scenarios by predicting the daily number of deaths that would have been observed in the 4 countries if the lockdown had been implemented at the same time as Hubei’s (3 days after the outbreak hit 50 cases). This timing would correspond to the following dates: February 25 for Italy, March 2 for France, March 3 for Spain, and March 6 for the UK. Finally, we estimated the relative change in the number of total deaths in the counterfactual scenario, compared to the observed one. All the analyses were performed using R software .To take into account the COVID-19 incubation period and the mean time between the symptoms onset and death, we assumed an 18-day lag between the national implementation of the lockdown and the start of its effects.We found that a more rapid and homogeneous response would have avoided a substantial number of deaths. Our results underline the need of strengthening public health emergency preparedness at national and global levels. Currently, no health care system can sustain an uncontrolled epidemic of COVID-19 or similar disease. Community containment measures are still the most important interventions to minimize the health impact of a possible second wave of infections, avoiding the unnecessary loss of lives.


This is an important crop for human consumption with high nutritional value due to their low calorie and fat content, providing various vitamins and minerals, especially iron. These NPs were obtained by means of the sol-gel method and heat treatment; the resulting powder material was characterized using X-ray diffraction and scanning electron microscopy and the influence of these NPs on plants was measured by estimating the germination rate, monitoring morphological parameters and evaluating phytotoxicity. The photosynthetic activity of the spinach plants was estimated through the quantification of the Ratio of Oxygen Evolution (ROE) by the photoacoustic technique. Samples of TiO2 powder with particle size between 9 and 43 nm were used to quantify the germination rate, which served to determine a narrower size range between 7 and 26 nm in the experiments with Ag-TiO2 NPs; the presence of Ag in TiO2 powder samples was confirmed by energy-dispersive X-ray spectroscopy. The analysis of variance showed that the dependent variable (plant growth) could be affected by the evaluated factors (concentration and size) with significant differences. The statistical trend indicated that the application of the Ag-TiO2 NPs suspension of lowest concentration and smallest particle size could be a promoting agent of the growth and development of these plants. The inoculation with NPs of 8.3 nm size and lowest concentration was related to the highest average ROE value, 24.6 ± 0.2%, while the control group was 20.2 ± 0.2%. The positive effect of the Ag-TiO2 NPs treatment could be associated to the generation of reactive oxygen species, antimicrobial activity, increased biochemical attributes, enzymatic activity or improvements in water absorption.In this work, the effect of the inoculation of silver-incorporated titanium dioxide nanoparticles (Ag-TiO The demand for healthy food products with nutritional quality has increased . In part2) is one of the most abundant compounds on our planet [Titanium dioxide (TiOr planet  and it ir planet . The potr planet .Nanoparticles (NPs) are materials that range from 1 to 100 nm in size; to this scale the surface area to volume ratio increases drastically, which enhances the reaction efficiency in applications related to interactions with external substances, such as photocatalysis [2 NPs in photocatalytic applications is based on the shifting of their band-gap energy to the visible region of the spectrum, through the incorporation of impurities and the increase of the surface/volume ratio [2 with Ag prevents the fast recombination process of electron-hole pairs, which improves its photoactivity [An effective strategy to improve the performance of TiOme ratio . Silver me ratio ; in partme ratio ; these nme ratio . On the activity , 15.Cumumis sativus), which led to a reduction of plant biomass of 75 and 35% regarding control, respectively. In this case, they found a positive correlation between the bioavailability and potential of oxidative stress in plants, and the particle size, concentration and species of NPs; in addition, the same authors found that the bioaccumulation in plant tissues and the activity of superoxide dismutase and peroxidase in root cells were proportional to the concentration of the nanosized material [Although nanotechnology has great potential for the development of plant science and production systems , the expmaterial . In othematerial .The objective of this work was to give an initial approach to the study of the interaction between nanometric titanium dioxide with silver incorporation and spinach seedlings, studying some growth, physiology and phytotoxicity parameters.2 NPs were obtained using the sol-gel method [4, obtained from alkoxide hydrolysis, and to grow anatase TiO2 crystal structure [2 NPs were synthesized through the same method, using titanium tetraisopropoxide (MERCK 98%) as a precursor; then, the heat treatment was carried out at temperatures of 400, 500, 600 and 700°C for two hours. The samples were characterized by X-ray diffraction (XDR) and the average particle sizes were estimated using Scherrer´s equation [2 samples was analyzed with Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS).The Ag-TiOl method . In the tructure . TiO2 NPequation . The com2 NPs in distilled water at concentrations 2500, 20000, 40000 and 60000 mg/L were treated in an ultrasound bath for a period of three hours; the spinach seeds (S. oleracea) of the Viroflay variety were submerged into these suspensions for three days under daylight exposure for alternate periods of two hours. After this process, the seeds were kept on absorbent paper with daily watering until germination. Then, 10 plants per treatment were grown during 16 days in plastic bags which were pierced to avoid water stagnation, and which contained a previously sterilized hydroponic substrate. The seedlings grew under greenhouse conditions with 64.0 ± 0.1% relative humidity and 24°C; 60 mL per day of the fertilizer and water mixture were added to each plant of each treatment, including those of the control group. In The suspensions of Ag-TiOA conventional synthetic fertilizer was used: a mixture of 0.37 g urea and 0.31 g nitrogen-phosphorus-potassium (NPK) diluted in 100 mL of distilled water was applied to each plant daily; the equivalence by surface area and percentage for primary macronutrients, to produce 1000 kg/ha is 20 kg/ha of NPK (8-24-16) and 10 kg/ha of urea. Subsequently, morphological measurements were taken daily for sixteen days, recording the number, length and width of the leaves produced and the height of the plant. The results were validated using a multi-factorial analysis of variance with a significance level of 95%; the factors were particle size , concentration  and growth parameters ; the number of applied treatments was 64, not counting the control group, each one with 10 repetitions. The used post hoc analysis was the Tukey's test for mean comparison.2 without the incorporation of silver were used at concentrations of 0.25, 2, 4 and 6%; for each treatment, 20 spinach seeds were arranged in order to define the appropriate range of this parameter in a following experiment that allowed to study the effect of silver incorporated NPs on the plant growth. The inoculation process was done as described in the previous section; all seeds were supplied daily with distilled water. The germination was considered achieved when the root was 2 mm long and the corresponding parameters were calculated as reported by Feizi et al. [AGT = ∑FX/∑F, where F is the number of seeds germinated at time X, which is given in days since inoculation. The Germination Rate (GR) was found using the equation GR = (a/1) + (b-a/2) + (c-b/3) + … + (n-(n-1/N)), where a, b, c, …, n is the number of seeds that germinated after 1, 2, 3, …, N days from the beginning of inoculation. We only considered AGT and GR as markers of phytotoxicity because these are simple parameters of easy observation. The results were validated through an Analysis of Variance (ANOVA).In a first experiment, the suspensions of TiO2, one plant of each treatment was randomly selected and moved from the greenhouse to the laboratory; there, they were kept in darkness for 30 minutes before taking photosynthetic activity measurements. This procedure was repeated for 20 days. The ratio of oxygen evolution (ROE) was measured using the photoacoustic (PA) technique, a photothermal method in which the sample is periodically impinged with light pulses, whose energy is partially absorbed and transformed into heat. The absorption of this modulated frequency light produces heat and, consequently, periodical changes of pressure in the adjacent air to the sample surface; these variations are detected with a microphone and the analysis of the corresponding signal allows to track the oxygen evolution, generated during the photosynthetic activity, considering the saturation of the photobaric process caused by incidence of continuous light over the leaf [From the group that germinated from the seeds previously treated with Ag-TiOthe leaf . In Fig 2 samples are shown in 2, corresponding to planes (101), (103), (200), (105) and (204), respectively. With the rise in temperature, the intensity of the peaks increased and their width decreased; this indicates greater crystallinity of the material [The diffractograms of Ag-TiOmaterial . The ave2 powder samples, the characteristic peaks of the anatase and rutile phases were observed, as shown in In diffractograms from TiOτ is the particle size in nm; K = 0.9 is a shape factor; λ = 0.154 nm is the X-ray wavelength; β is the line broadening at half of the maximum intensity in radians and θ is the Bragg angle.Where Considering that the effect that multiple scattering has on the dynamic light scattering (DLS) technique is enhanced by the increase in concentration, the measurements of hydrodynamic diameter might not be accurate for values higher than 500 mg/L. In this work, this method was not used because the concentrations were higher than this technical limit. Furthermore, it has been reported that for a concentration of 500 mg/L the particle size is not strongly affected by the suspension situation, after sonication .2 and Ag-TiO2 NPs powder samples.Care was taken to ensure that the after-sonication suspensions were used immediately in the inoculation process and the analysis was done supposing that the sizes in suspension at each concentration were similar to those obtained through this primary characterization of TiO2 [2 sample  show the common behavior of all samples, highly agglomerated particles with rocklike structures conformed by spherically shaped nanostructures. The EDX graph corresponds to this sample and it confirmed the presence of Ti, Ag and O components.The concentration of the elements contained in the nanoparticle material is shown in 2 . In Fig 2 and measurements of germination were examined using multifactorial ANOVA. The P-values proved the statistical significance of each of the factors (particle size and concentration) with a 95% confidence level, which indicates that each of them has a direct effect on the germination of the seeds.Spinach seeds were exposed to suspensions of nanometric particle size TiOThe AGT and GR of the spinach seeds were calculated from the collected data and the resultant values were noted in et al. found similar results [2; the time was 3.99 days, while 4.05 days were registered for the control. Other authors also indicated that the treatment with nanometric size TiO2 favored the generation of active oxygen, superoxide anions and hydroxide; this management improved the resistance to stress of the seeds and promoted the absorption of water and oxygen, which accelerates the germination [Feizi  results , they remination .2 was applied to fennel seeds [2. This would improve the resistance to stress of the seeds and the absorption of water and oxygen in germination.In the same experiment in which TiOel seeds , the autel seeds , suggestThe negative effects of this kind of nanomaterial on plants, associated with high concentration and larger particle size, may be related to the aggregation of clusters that clog the root pores. This interrupts water absorption and leads to an increase of AGT and a decrease of GR .2 NPs suspensions were correlated to the morphological parameters of the treated plants as a function of time. From this analysis described in The graphics of multifactorial ANOVA interaction are shown in 2 on the activity of enzymes involved in nitrogen metabolism, such as nitrate reductase, glutamate dehydrogenase and glutamine synthase or glutamic-pyruvic transaminase. These enzymes help the plants to absorb nitrates and stimulate the conversion of inorganic nitrogen to organic nitrogen, in the form of proteins and chlorophyll, which increase the weight of the plant and promote its growth and development [According to the graphs in elopment , 33. Othelopment . This haelopment .et al. [The behavior of the growth parameters as a function of the concentration and particle size is compared to that of the control group in et al. , who arget al. .2 NPs suspension, described in In 2 NPs, because this nanomaterial could improve the absorption of light and therefore the efficiency of its transformation into electrical and chemical energy during photosynthesis [2 NPs could be translocated to vegetative organs such as leaves or stem during the plant's growth [In ynthesis . On the s growth . Thus, ts growth .Principal components analysis (PCA) is a statistical procedure of variable reduction that creates few components that represent most of the variance in a set of observed variables. It is an unsupervised pattern recognition method for exploratory analysis of data to express them in such a way as to underline their similarities and differences, as described in detail elsewhere . In thisFrom the plots of PCA scores, in According to the score graphs of the PCA in 2 NPs suspensions on the photosynthetic activity of spinach plants could be associated with the generation of reactive oxygen species, oxidative stress, genotoxic effects, generation of inhibitory enzymes and decrease in cell viability. However, it should be borne in mind that smaller NPs have greater penetration capacity and mobility through plant tissues, while larger particles can be trapped in the roots [The effects of the treatment with Ag-TiOhe roots . In this2 nanopowder improves spinach growth and chlorophyll formation, and it also increases Rubisco activity as well as the photosynthetic rate during the growth stage, but the effect is inversely proportional to particle size and concentration [2 damage the lipidic structure of the membranes, which decreases the photosynthetic capacity [Taking into account the control group, the results suggest that a better response to the treatments is obtained when the metabolism of the plant is not drastically altered. The TiOntration , since tcapacity .Partial Least Squares–Discriminant Analysis (PLS-DA) does not find hyperplanes of maximum variance between the response and independent variables as PCA, but it projects the predicted and observable variables to a new space, in order to find a linear regression model that allows a supervised pattern recognition method, opening the possibility of making future samples predictions on the modeled classes. A threshold between the predicted and observable values is calculated and the data below this parameter are associated to the distancing of the sample from the modeled class. This threshold splits the classes with the lowest probability of false classifications of future predictions and it is estimated from the distribution of the predicted values obtained through the PLS-DA model through calibration samples , 40.The distribution of the class values estimated for the calibration and the validation data sets are shown in Figs For 2% concentration of the suspension, a point corresponding to the size of 7 nm v, predicted as 0 nm appears, and for the 4% point there is a point related to the size of 10 nm v, predicted as 8 nm v. On the other hand, for the suspension with a particle size of 7 nm, a concentration point 2% v was predicted as 0 or 0.25 v; while with 10 nm a point of 4% v was predicted as 2% v.Both in Figs 2 NPs of particle sizes between 7.3 and 8.3 nm, at the lowest concentrations of 0.25 and 2%, resulted in the increase of growth parameters, seedling height, leaf dimensions and number of leaves, between 30 and 49%.The effect of the inoculation of silver-incorporated titanium dioxide NPs in spinach seeds has a direct dependence on the phytotoxicity, morphology and photosynthetic activity of these plants, depending on the particle size and concentration. In the synthesis of the NPs by sol-gel method, the anatase phase of the titanium dioxide was obtained and the particle size was modified via temperature change in heat treatment. With respect to the control group, the inoculation of the Ag-TiOAccording to the estimated ROE, photosynthetic activity increased by 21.78% due to the inoculation of NPs suspensions with 8.3 nm size at 0.25% concentration, taking into account that for the control, the average ROE was between 20.2 and 24.6%. The average germination time was reduced by 10.92% with the treatment of the seeds in the solution of concentration 0.25% and particle size of 9 nm. Although the factors of growth were not improved with the application of the suspension of 33 nm particle size at this same concentration, the germination rate increased at 256.27%.The treatments that favored the growth of the plants correspond to ROE responses similar to those of the control group. This result was statistically demonstrated through the PCA and the PLS-AD, which explains a high percentage in the variance of the data due to the difference in the characteristics of the applied suspensions and discriminates between the alterations in the photosynthetic activity of the plants.2 NPs treatment for spinach plants were obtained with a particle size between 7 and 8 nm at a concentration of 2%. This effect could serve as a starting point to understand the consequences of the inoculation of Ag-TiO2 NPs on the physiological and morphological parameters related to plant growth. This information may be useful because these NPs could prevent the exacerbated addition of certain exogenous material to the soil or the environment, which is important for the improvement of crops.The best results with Ag-TiOThe use of titanium dioxide NPs with silver incorporation could play a role in contemporary agriculture, because the use of these compounds with specific concentrations and particle sizes could be adjusted to the needs of each crop.S1 Table(DOCX)Click here for additional data file.S2 Table(DOCX)Click here for additional data file.S3 Table(DOCX)Click here for additional data file.S4 Table(DOCX)Click here for additional data file.S5 Table(DOCX)Click here for additional data file.S6 Table(DOCX)Click here for additional data file.