In this paper, we focus on the industrial production of porcelain in the Bordeaux area (France) in the 19th century. Our main objective is to assess the evolution of production technology of the same manufactory over a period of more than 40 years. A multi-analytical approach was used to investigate glazes and bodies of thirty-four sherds of biscuit and porcelain found in an archaeological context. The microstructural, chemical, and mineralogical characterization was performed using a combination of scanning electron microscopy, coupled with energy dispersive spectroscopy (SEM-EDS), particles induced X-ray and gamma emission (PIXE-PIGE), and X-ray diffraction (XRD). Results obtained on the characterization of the ceramic production technologies and on the chemical modification over time contributes to investigate this industrial production, which is not well documented by the written archives. The examination of the biscuits, rare artifacts, showed that the porcelain bodies were produced by mixing kaolinitic clays, quartz, and potassium feldspars. The mineralogical analysis of the ceramic supports allowed hypotheses to be put forward on the temperatures of the biscuit firing (around 950 °C) and the second firing (over 1200 °C). Furthermore, the treatment of the compositional data, including both glazes and bodies, using multivariate statistical analysis, revealed different types of production corresponding to the different chronological periods of production at Bordeaux throughout the 19th century. These results will enable us to consider the possibility of authenticating non-stamped and undecorated pieces. During several decades of the 19th century, between 1850 and 1895, the French Vieillard & Co. manufactory produced porcelains, among other things. Unfortunately, only few objects from this production remain in museums or private collections. Recently, through archeological excavations in Bordeaux (France) performed in 2015 by the Centre Archéologie Préventive de Bordeaux Métropole, waste dumps of the Vieillard & Co. factory were discovered and have provided significant quantities of porcelain fragments ,1716,17]The ceramic support is characterized by a large number of closed pores due to the high viscosity of the melt, so that the gases emitted during firing could not escape a 18]. A. A18]. AThe chemical composition of the ceramic supports of the porcelains was determined by SEM-EDS for the whole corpus (concerning major and minor elements), as well as by PIXE . All the chemical compositions are shown in the 2 contents above 64 wt%) and aluminium (Al2O3 contents between 24 and 30 wt%). The bodies are non-calcareous (<0.7 wt% in CaO) and contain a low iron concentration (<0.4 wt% in Fe2O3), which confirms the whiteness of the porcelain body. The fluxes used are alkaline, rich in potassium (between 3.3 and 4.6 wt% in K2O) and sodium (1.3 and 2.4 wt% in Na2O), , .2O content and a decrease in Na2O content) concur, from a temporal point of view, with the takeover of the factory by Albert and Charles Vieillard. However, it is important to emphasize that the small number of samples induces relatively large standard deviations, which complicate their interpretation and thus, the certain attribution to a given group.The main variations in chemical composition are observed between the production group of Jules Vieillard (c. 1855) and the two groups of his sons. These chemical variabilities  allows for the visualization of the projection of the individuals and variables [2O (2.4 wt% on average) and CaO (about 0.7 wt%) contents, and (2) the Vieillard sons productions, which are distinguished by higher Al2O3 (more than 27.5 wt% on average) and K2O (more than 3.9 wt% on average) concentrations and lower SiO2 (less than 66 wt%) concentrations  does not appear to belong to the chronological group to which it was archaeologically related. Furthermore, a comparison of the chemical compositions of the porcelain bodies and those of the biscuits corroborates the identification that has been made of these sherds. Actually, the group of the biscuits (c. 1865) overlap with the group of porcelains corresponding to the same chronological period.Principal component analysis (PCA) after transformation into centered log-ratio (clr) of the concentrations obtained by SEM-EDS  contain a high concentration of manganese (about 80 ppm), while the productions of the sons present high contents of rubidium (around 280 ppm on average). This concentration could be correlated to the higher contents of potassium, and thus to the presence of potassic feldspars .2O3·2SiO2), quartz (SiO2), and cristobalite (SiO2) (2 and more than 24 wt% in Al2O3) and according to SEM observations .Nineteen of the porcelain clay supports were analyzed by X-ray diffraction. The diffractograms reveal the presence, in all the samples of the corpus, of an amorphous phase highlighted by an elevation of the signal background. The identification of this amorphous phase is consistent with the vitreous nature of the porcelain body. The main mineralogical phases identified in all the ceramic supports are mullite (3Ale (SiO2) . The preAs previously discussed, the presence of secondary mullite in the bodies indicates that the firing temperature is at least 1050 °C ,13. FurtThe firing of hard-paste porcelain is a key point of its production, because its price depends mainly on this step. Indeed, the firing of hard porcelain makes it an expensive product, essentially because of the high cost of wood, which must be used in large quantities to reach the desired high temperatures . At the Although the phases identified in the porcelain body are the same in all samples, it should be noted that the ratio of quartz (Q) to mullite (M) peaks decreases throughout the production period . As a maThe study of the ceramic supports of the archaeological sherds having enabled us to distinguish the various periods of production of the manufactory of Bordeaux, we will now focus more specifically on the glaze. Actually, this last one constitutes the only source of information available for non-destructive investigation.2), are identified as quartz grains. They could be the result of the glaze mixture, or even of the decomposition of the ceramic support during the second firing.All the fragments studied have a transparent, colorless glaze a. SEM obThe porcelain glazes were analyzed using two analytical techniques: SEM-EDS and PIXE. The first method allowed for the determination of major and minor elements for all the sherds in the corpus, while the PIXE allowed the detection and quantification of major, minor, and trace elements present in the glazes of 19 sherds. The complete results for each sample are presented in 2 contents higher than 74 wt%) and aluminium (Al2O3 contents between 13 and 16 wt%). In addition, the glazes contain alkaline fluxes: potassium (between 4.1 and 5.5 wt% in K2O on average) and sodium (between 1.6 and 3.3 wt% in Na2O). Finally, the presence of calcium (between 0.5 and 1.7 wt% in CaO) and the low content of Fe2O3 (0.3 wt% at the most) are noted  of the glazes, produced from the SEM-EDS and PIXE data, reveal two distinct groups a,b. The 2 suggests that quartz was added to the glaze recipes. The addition of feldspars could explain the presence of silica, aluminum, potassium, and sodium. As for calcium, which is not abundantly present in the productions of Vieillard’s sons, it could have been added in the form of chalk [From the chemical elements detected in the glazes, some hypotheses can be made about the ingredients used. The significant presence of SiOof chalk . Nineteeof chalk ,22. ThisThe trace elements, detected by PIXE, also provide valuable information for discriminating these productions. The presence of nickel and manganese is characteristic of the first period of production identified (around 1855). On the contrary, the productions of the sons of Jules Vieillard are marked by higher contents of rubidium and copper . These dFew archaeometric studies on porcelains (body and glaze) of the 18th century are available in the literature. We consider published data on European hard-paste porcelain for comparison with data obtained on productions from the Vieillard & Co manufactory. These published works focus on hard porcelains from museums and excavations in consumption sites ,31,32,332O3 vs. K2O bivariate scatter plot of porcelain bodies. It reveals that the chemical compositions of ceramic bodies evolved over time, and that it is possible to separate distinct compositional groups. The bodies of Meissen porcelains, dated approximately between 1725 and 1782, present a high Al2O3 content (more than 32 wt%) compared to the French productions of Vieillard & Co. On the contrary, the bodies of the English and Italian porcelains have an Al2O3 content close to that of the samples from the Vieillard & Co. factory (c. 1855). 2O scatter plot of porcelain glazes. Once again, the different productions can be distinguished from each other, except for the glazes of the English productions (Bristol and Plymouth). Their compositions are close to the Saxon productions of Meissen and the first production of Vieillard & Co (c.1855)  b. As a result, it seems possible to use these data in a broader context in order to document the development and experimentations in the production of porcelain in the 18th and 19th centuries in Europe. Besides, these data deserve to be completed and compared with data from other French or European porcelain factories of the 19th century.To conclude, the proposed methodological approach is a first step in the characterization of this corpus of biscuits and porcelains of the Vieillard & Co manufactory. It has allowed a better understanding of this little-known production. In this paper, a group of twenty-eight archaeological sherds, which are representative of three successive production periods of the manufactory between 1851 and 1895, were investigated. The chemical composition and the microstructure of the porcelain body and the glaze were examined in order to collect information on ceramic characteristics and production technology. The analysis of the rare porcelain biscuits revealed that the support of the porcelains is made up of kaolinite clays, quartz, and potassium feldspars. Mineralogical study of the ceramic supports allowed hypotheses to be made about the temperatures of the first firing (around 950 °C) and the second firing (over 1200 °C). In the future, a study of the diffractograms by Rietveld analysis could be used to obtain more detailed evaluation of the appearance of mullite and its development in the body, but also to refine the discrimination of the productions due to the proportion of mullite and quartz ,25,34.The results allowed us to establish two compositional groups that differ in both the composition of the glazes and the bodies. Moreover, it is possible to distinguish the porcelain productions of the father’s and sons’ periods, thanks to both glaze and body composition analyses. Thus, it is interesting to note that significant changes in recipes and raw material supplies concur with the takeover of the factory by sons Albert and Charles. Further investigations will hopefully yield more details on the raw materials involved in the production of these long-neglected objects. Although these preliminary results contribute to answer the question of the authentication of unstamped and undecorated pieces, it should be noted that these data concern a very limited panel of French hard-paste porcelain productions of the 19th century. The chemical reference database will have to be extended to take into account other contemporary productions . From the perspective of a wider and more exhaustive study, the use of portable X-ray fluorescence spectrometers would be ideally suited for rapid, non-destructive, and in situ analysis of porcelain objects ,36.


With macroscopic evaluation every two days for 28 days, the following variables were observed: skin integrity, presence of blisters, hyperemia, exudate, bleeding, edema, crust, peeling and granulation tissue.  a quasi-experimental study conducted with 60 Wistar rats, randomized into four groups with 15 animals each. Group 1 (Control); Group 2 ; Group 3 (Photobiomodulation); and Group 4 . A wound was induced by applying 1 mg of doxorubicin to the subcutaneous tissue of the back of the animals. The concentration of topical hyaluronidase was 65 turbidity units/g and the energy employed was 1 joule of 100 mW red laser  the animals from the groups subjected to photobiomodulation obtained better results in the assessment of the following variables: bleeding, hyperemia, exudate, intact skin and edema.  it was evidenced that the association of photobiomodulation with topical hyaluronidase was effective in reducing the local effects and assisted in the wound healing process, and that PBM alone was able to prevent appearance of lesions.  It can remain in tissues for up to 28 days, which requires constant evaluation,Currently, dexrazoxane is the antidote used in DOX extravasation. Its use is approved by the Food and Drugs Administration (FDA) and by the European Commission and has 98% efficacy. The mechanism of action is binding of the drug to the iron molecule preventing the formation of free radicals,-,,Hyaluronidase is a widely used antidote in the extravasation of chemotherapeutics; however, it is specific for non-DNA-binding vesicants , although it is a potential antidote for anthracyclines. This medication modifies tissue permeability by hyaluronic acid hydrolysis, promoting reabsorption of fluids and reducing the edema. This enzyme is an antidote recommended by the Oncology Nursing Society (ONS), which 1.0 ml subcutaneous application of 150 UI/ml to the extravasation area,-Photobiomodulation (PBM) consists in irradiating non-ionizing light and is classified according to its wavelength into visible red (622-780 nm) or infrared . It is quite used to accelerate the healing process of various types of lesions, promoting improvements in the patients’ quality of life and speeding up the treatments2+ ions, favoring the intended biological response  and increasing cell differentiation, proliferation and migration,For this, it is necessary that light is absorbed by chromophores, which are interrelated molecules  with the ability to absorb light. Cytochrome C Oxidase (CCO) is the main chromophore and is located in unit IV of the mitochondrial respiratory chain. CCO absorption mainly by the red wavelength leads to photodisconnection of nitric oxide (NO), resulting in a reduction of oxidative stress and, consequently, in an increase in the production of reactive oxygen species (ROS), ATP and CaThe association between topical hyaluronidase 65 UTR/g and PBM is already used in an Oncology Outpatient service of a tertiary-level Public Hospital from the inland of the state of São Paulo. However, despite excellent results, the number of patients with extravasation is low, and there is no scientific evidence on this association. Consequently, it was necessary to conduct an experimental study to evidence this practice, thus justifying this study.Therefore, the objective of this research was to investigate the effect of using different agents  in preventing the formation of lesions caused by antineoplastic DOX extravasation, as well as the reduction of lesions formed after extravasation of this drug.Rattus norvegicus species, aged between 3 and 4 months old. In randomized experimental studies, the researcher randomly assigns the subjects to a control group and to one or more experimental groups, minimizing selection bias, in addition to allowing isolating the effect of an interventionAn experimental study conducted with 60 albino Wistar adult female rats of the The experiment was carried out from 08/15/2019 to 09/16/2019 at the Experimental Laboratory for Diagnosis of Zoonoses, Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Zootechnics, UNESP, Botucatu-SP, Brazil.Instituto de Biotecnologia, IBTEC) of the “Júlio de Mesquita Filho” State University of São Paulo. Immediately after that, they were kept in the Experimentation Vivarium for a 15-day adaptation period, and only then were they submitted to the experiment. Female rats were selected due to their differences regarding behavior and aggressiveness when compared to males, easing manipulation. Throughout the period, temperature, ammonia level and bed change were controlled, as well as water supply and ad libitum feed. They were clinically examined by a veterinarian at admission to the laboratory and during the entire experiment. In order to ensure environmental enrichment, paper rolls were places in the cages in an attempt to reduce the stress caused by manipulation and isolation.The animals were provided by the Creation Vivarium located in the Biotechnology Institute .Envelope 2: Hyaluronidase Group (H).Envelope 3: Photobiomodulation Group (PBM).Envelope 4: Photobiomodulation + Hyialuronidase Group (PBM+H).Subsequently, one of the laboratory team members made a draw with numbers from 1 to 60. The first 15 animals drawn were allocated to Envelope 1, and so on.® ventilated racks, kept under room temperature and with free movement. It is important to note that, after DOX inoculation, the animals were separated, keeping them in individual cages. Each group consisted of 15 animals that were housed in rectangular polypropylene cages with 5 animals each, placed on ALESCOThe cages were identified with the numbers corresponding to the animals and with the group to which they belonged.Considering that there is 50% occurrence of necrosis cases control) and assuming that application of the treatment reduces this percentage to zero (no necrosis), the minimum size for carrying out the experiment with a 5% margin of error, 95% compatibility and 90% power will be 15 animals per group .The qualitative variables analyzed were related to the appearance of the extravasation site and to the formation or not of lesions such as: intact skin, blister (intact or ruptured), hyperemia , exudate , bleeding , edema , crust , peeling  and granulation tissue .The process of wound formation was monitored by the researcher every 48 hours for 28 days, through an evaluation form that included presence of intact skin, blisters, hyperemia, exudate, bleeding, edema, crust, peeling and granulation tissue(15). At the same time, a database of photographic records  was prepared to assist in interpreting evolution of the wounds. Angle and distance of the photographs were calculated by a professional photographer from the Botucatu Medical School, in order to standardize the images. After the adaptation period, the animals were subjected to inhalational general anesthesia with isoflurane gas and trichotomy of the dorsal region with an electric trichotomizer and administered 1.0 mg of DOX (0.5 ml) in the subcutaneous tissue located between the scapula and the end of the ribs, using a graduated 1 ml syringe and a 13 G x 4.5 mm hypodermic needle. The DOX vial contained 10 mg in 5 ml, making up an equivalent of 2 mg/ml. 0.5 ml of the solution was aspirated, containing a total of 1 mg of DOX. A research study carried out with extravasation in rats proved that an intradermal injection of 1 mg of DOX was capable of causing necrosisCruz Vermelha Pharmacy in Botucatu-SP, with a concentration of 65 UTR with 1 g base cream.The hyaluronidase used in the study was manipulated at the After DOX inoculation, the antidotes were applied as follows:- Control Group (no antidote): no antidote was applied;- Hyaluronidase Group (H): the topical hyaluronidase antidote was applied 15 minutes after inoculation and, daily, in the form of an ointment on the entire back of the animal, even in the presence of lesion;- PBM Group: application of 100 mW PBM, 1 joule red light (10 seconds), wavelength of 660 nm, at the inoculation point occurred 10 minutes after administration of doxorubicin. In the subsequent days, in the animals that did not show lesions, 1 point of 1 joule (10 seconds) of PBM was performed at the inoculation point. When lesions appeared, in wounds up to 1 cm in area, a 1 joule point was irradiated (10 seconds), with a total energy of 1 joule in the center of the lesion; in wounds up to 2 cm in area, it was irradiated to the North, South, East and West , with a total energy of 4 joules. Topical dressings with primary coverage were not performed, leaving the lesion area exposed.- PBM+H Group: PBM was performed as reported in the PBM Group and, immediately after the laser, the hyaluronidase antidote was applied, as described in the H Group.A pen-shaped semiconductor diode laser device was used , which emits two wavelengths: a laser diode at 660 nm (red) and a laser diode 808 nm (infrared). Peak emission power was 100 mW, in continuous mode delivery. The spacer at the end of the device was used, as well as a PVC film to avoid cross-contamination and wear of the appliance. The wound formation process was monitored by the researcher every 48 hours for 28 days and euthanasia was performed at day 30.After data tabulation, a qualitative and descriptive analysis of the variables  was performed by group  throughout the treatment days.Comissão de Ética no Uso de Animais, CEUA) at the Botucatu Veterinary and Zootechnics School - UNESP, with protocol No. 0026/2019.The research was approved on 02/11/2019 by the Commission of Ethics in Use of Animals . We believe that this loss can be related to several factors such as: toxicity generated by anthracycline, toxicity by hyaluronidase, and factors related to animal behavior. Although the groups were evaluated every two days, hyaluronidase was administered daily, with the possibility that such manipulation of the animals be considered stressing. It was noticed that some animals from the PBM group (4/15: 26%) did not show lesions . In animHyperemia was already observed at the first evaluation day (D2) in most of the animals analyzed from groups C and H, extending up to D16. It was observed that in the groups in which PBM was used, few animals presented hyperemia, with a maximum peak at D4 for both groups, with a lower frequency of animals involved, PBM (5/15: 33%) and PBM+H (9/15: 60%) .Exudate was mostly found in Group C (14/15: 93%) starting at D10, reaching a maximum number of animals at D12 and extending until the end of the experiment. The animals that participated in the PBM and PBM+H groups did not show formation of exudate until the end of the experiment.Of the animals from the groups with PBM, only one presented bleeding during the entire research. In turn, the animals from groups C (9/15: 60%) and H (7/15: 46.6%) showed bleeding at the third evaluation day (D6).Crust was observed throughout the research in animals from all groups, although in a smaller number of animals from groups H, PBM and PBM+H.The animals from Group C presented a higher rate of necrosis on all treatment days, starting on the fourth evaluation day (D4) and extending steadily and progressively throughout the study. The animals from the H, PBM and PBM+H groups also showed necrosis, although more superficial, in lower numbers, and with an improvement in the lesion at the end of the treatment.Edema was observed in 14 (93%) animals from the Control Group already at the first evaluation day (D2) . A lowerThe healing process with epithelial tissue was observed at D12 with animals from the PBM+H group. It was observed that, after 28 days of evaluation, two animals from the PBM and PBM+H groups showed complete healing of the lesions. At the end of the study, six animals (40%) from the PBM group and two (13%) from the PBM+H presented intact skin .There was premature death of 23 animals, which can be related to several factors, such as the toxicity generated by anthracycline and hyaluronidase and animal behavior. It was observed that the animals that died the most were from the groups that contained hyaluronidase. We infer that even when the ointment is being applied correctly to the back of the animal, due to its significant fluidity, it generated ease of licking and possible intoxication. Hyaluronidase has been widely used in ophthalmic and dermatological surgeries, as the enzyme degrades the hyaluronic acid matrix, increasing tissue permeability and favoring drug absorption. In addition to that, it is already widely used in EA management, subcutaneouslyThe toxicity generated by anthracycline corresponds to the symptoms observed in the animals, such as diarrhea and weight loss. As it is non-selective, DOX causes various side effects, such as nausea, vomiting, diarrhea and anorexia with consequent weight lossBetter preservation of skin morphology and reduction of edema and ulcer size were observed in an experimental study with Wistar rats that were administered an intradermal injection of vincristine and were treated with hyaluronidasePBM also plays an important role in the prevention or reduction of edema during tissue repair processes since, after all, the benefits related to reduction of the edema, oxidative stress and pro-inflammatory cytokines are already well establishedDuring this research, our study group published a retrospective cross-sectional study of the Oncology Outpatient service of a Public Hospital from the inland of the State of São Paulo, Brazil, with the objective of analyzing the effect of PBM and topical hyaluronidase on extravasation and infiltration of antineoplastic drugs in a 21-month period. 8 extravasations (among them 01 of anthracycline) and 7 infiltrations were reported. All were followed-up and received a mean of 2 PBM sessions (1 joule - 100 mw) and topical hyaluronidase (65 UTR) 3 times a day for 4 days. It was found that there was no formation of lesions, even in the patient who used anthracyclineDuring DOX extravasation, there is cell death in the tissues underlying the extravasation site, with the release of free radicals triggering a marked oxidative stress, increasing the inflammatory process and causing necrosis,,From photochemical reactions, PBM restores the cellular function through the release of reactive oxygen species, causing cellular balance restoration by the production of antioxidant enzymes and most importantly, without deleterious effects to the organismThis is the first paper to investigate the association of PBM with topical hyaluronidase in DOX extravasation. However, the efficacy of PBM has already been proven in other types of lesion, even with the possibility of being associated with topical therapies. PBM is already quite used to heal wounds of various etiologies. In a study conducted to evaluate the effect of laser therapy at different wavelengths on the expression of growth factors and inflammatory mediators in the healing processes of pressure ulcers, it was observed that the wavelength of 658 nm was more effective. It is believed that this effect is associated with inhibition of the inflammatory processesIn a case study on anthracycline (epirubicin) extravasation in a central venous access (fully implanted catheter) in the right hemithorax, it was observed that the patient showed necrosis in 2/3 of her breast in the first 10 days, lasting for 32 days when she underwent a surgical procedure to dry the necrosis. It is important to report that no antidote was applied to this patient, as 24 hours had already elapsed since extravasation. A skin graft was placed in the site and, after 8 months, the breast reconstruction procedure was performedIn the study, we found that the granulation tissue was more evident in the animals from the PBM group, with onset of its appearance at D12, maximum peak at D18, stabilization from D20 and a sharp drop at D26, showing replacement of the granulation tissue by gradual epithelization with consequent wound healing of 2 animals from the PBM group and 2 animals from the PBM+H group. Sistema Único de Saúde, SUS). This study provides diverse evidence for using PBM associated with hyaluronidase in DOX extravasation, providing important and relevant information for the formulation of protocols by Oncology professionals. It has sufficient clinical relevance for the possibility of incorporating new technologies by the Unified Health System  with topical hyaluronidase (65 UTR) on DOX extravasation was effective in reducing the local effects and assisted in the wound healing process, as well as that PBM alone was able to prevent the appearance of lesions. This therapy is a good alternative to treat extravasation, with the possibility of being incorporated into the clinical practice.


The structure of the TiO2 layer drives the physical mechanism underlying the non-volatile resistance switching, which can be changed from electronic to ionic, enabling the synaptic behavior emulation. The presence of the anatase phase in the amorphous TiO2 layer induces the resistive switching mechanism due to electronic processes. In this case, the switching of the resistance within the range of seven orders of magnitude is experimentally observed. In the bilayer with amorphous titanium dioxide, the participation of ionic processes in the switching mechanism results in narrowing the tuning range down to 2–3 orders of magnitude and increasing the operating voltages. In this way, a combination of TiO2/Al2O3 bilayers with inert electrodes enables synaptic behavior emulation, while active electrodes induce the neuronal behavior caused by cation density variation in the active Al2O3 layer of the structure. We consider that the proposed approach could help to explore the memristive capabilities of nanolayered compositions in a more functional way, enabling implementation of artificial neural network algorithms at the material level and simplifying neuromorphic layouts, while maintaining all benefits of neuromorphic architectures.In this paper, we report an approach to design nanolayered memristive compositions based on TiO In some cases, to govern the concentration of oxygen vacancies in the active layer, oxidation of one of the device electrodes can be used by applying the external voltage. In particular, in a memristive structure of Ta/HfO2/Pt  elements are determined by the success of their integration with the transistor logic under the hardware implementation of spike neural network algorithms.A closer look at the list of the requirements reveals their poor compatibility with the physical principles, underlying the operation of memristive structures with analog resistance tuning based on ionic mechanisms:1.The claim for reduced variability of the operating parameters of memristive structures. Increasing the size of crossbar arrays unacceptably widens the spread of the operating parameters of memristive elements, hindering their use in neuromorphic and computing systems.2.The requirement for linearity of switching characteristics of memristive structures. As is known, the hardware implementation of multilayered neural networks on the basis of memristor logic provides recognition accuracy of 92% with 256 resistance levels (8-bit memristor cell) and up to ≈86% with 64 levels (6-bit cell) , being f3.The requirement for the conservation (stability) of the resistive state in time. When the resistive state is set by the distribution/concentration of ions in the active layer of the memristive structure, a crucial point is a rather high activation barrier for oxygen vacancy migration [3.9–6 eV in amorphous alumina with the formation energy of about 8 eV ]. A vari4.G0=2e2/h≈80μS. The estimates show that at operating write voltages of 1–3 V , such modification corresponds to an increase in the programming current level by Iprog≈G0(1−3V) = 80−240μA  circuit remains relevant even for memristive structures based on solid electrolytes (CBRAM or ECM), in which the resistive switching is associated with the electrochemically governed growth and dissolution of the local conductive region, consisting of ions from an active electrode, into the oxide/chalcogenide matrix. In particular, for ECM cells, if the size of the narrowest part of the conductive metal filament in the oxide matrix changes by one atom, the conductivity will be modified by 80−240μA . With prIn line with the above findings, all attempts to advance the multilevel logic at the hardware implementation of neuromorphic circuits with memristor elements, based on purely ionic processes, led to the widespread perception that such materials are of purely academic interest with the absence of serious technological prospects. Here, we propose to take a fresh look at the design of nanolayered memristive structures. We show that the same composition can provide a functional analog of a synapse, both due to electronic and ionic processes, wherein the transition between them is governed by the physical parameters specified during the synthesis of the functional layers. In our opinion, the reliance on electronic processes should provide smooth integration of memristive structures into circuits of neuromorphic computing architectures at a given paradigm of circuit engineering approaches in modern electronics.2O3/TiO2 thin-film layers was chosen (2 substrate with an adhesive layer of Ti (25 nm). Atomic layer deposition (ALD) was used to synthesize the functional oxide layers . ALD of 30-nm-thick titanium dioxide was carried out at temperatures of 150–200°C using titanium tetraisopropoxide [Ti(OiPr)4] and water vapor (H2O) as precursors. Synthesis of a functional 5-nm-thick Al2O3 layer was carried out at 150°C using trimethylaluminum and water vapor (H2O). The structure of the titanium dioxide layer solely depends on ALD temperature Tc. At Tc = 150°C, the titanium dioxide layer is completely amorphous, whereas at Tc = 200°C, it is amorphous with the inclusion of the anatase phase crystallites . The surface morphology of platinum and titanium oxide films was studied with atomic force microscopy . The study of local resistive properties was carried out in the mode of tunneling atomic force microscopy using probes with a conductive platinum coating.Top platinum and copper electrodes with a thickness of 100 nm and a diameter of 350 μm were deposited through a mask by ion-plasma sputtering at 150°C. Mechanisms responsible for the appearance of resistive switching and the switching effect itself were studied based on I–V characteristics measured using the Keithley 4200-SCS semiconductor characterization system. During the measurements, the bottom platinum electrode was grounded.Aluminum oxide was chosen as the active layer responsible for the analog switching of the resistance for the following reasons. First, it is an oxide of a non-transition metal, and the effect of redox reactions on the resistive switching processes may be excluded. Second, it is a high-resistance material [with a band gap of 6.2–6.5 eV for amorphous alumina ] with lo2O3 layers. At a certain concentration of (OH-) groups, exceeding 3×107 (OH-) groups per aluminum atom, a transition in the character of conductivity from electronic to ionic is observed. The ionic conductivity is related to the transport of H3O+ ions via the formation of bonds with oxygen anions located near the AlO defects , the conductivity of aluminum oxide is electronic in nature . At that defects . ALD syn2O3/TiO2 compositions with a predominance of the ionic resistive switching mechanism. No resistive effects were observed in the titanium dioxide layer with the anatase phase, and its use made it possible to turn to the electronic nature of resistive switching in two-layer memristive compositions  are applied to the top electrode . Using te layers , the anaructures . We obse50–295 K  that ind2O3/TiO2 structures, accompanied by changes in its resistive properties, modifies the way the analog resistive switching proceeds (2/Al2O3/Pt-TE) and reverse (Pt-BE/Al2O3/TiO2/Pt-TE) orders of oxide layers are symmetrical.Rearrangement of the titanium dioxide layer in Alproceeds . In partIf copper is a material of the top electrode in memristive compositions, a region of negative differential resistance exists in the I-V characteristics. The tuning range of the resistance and operating voltages do not differ from those for the structures with platinum electrodes. However, a pronounced relaxation of the intermediate resistive states to the initial high-resistant level of the two-layer structures is observed.2O3 layer of memristive Pt-BE/TiO2/Al2O3/Pt-TE structures with an anatase phase in the titanium dioxide film, the main transport mechanisms are the hopping transport of electrons via trap levels and currents limited by space charge (SCLC) (ab initio modeling (At the electronic nature of conductivity in the ALD-deposited Ale (SCLC) . Accordimodeling , the tra19 cm–3. According to our model of electron transport in the active aluminum oxide layer, the switching of the resistance within the range of seven orders of magnitude  within one order of magnitude . In this case, further injection of electrons strongly changes the concentration of free charge carriers n in the bulk of the film  is the spin degeneracy factor, and H is the concentration of traps.where, Upon reaching the TFL mode, a transition to the trapless SCLC takes place, and quadratic I-V characteristics are observed. In fact, the range of the current variation, corresponding to the abrupt increase of the current when approaching the TFL mode, is determined, according to Eqs 1, 2, by the band gap and the energy level of traps relative to the Fermi level. For the same mechanism of electron transport, the range of the resistance switching narrows down to 2–3 orders of magnitude for the materials with a smaller band gap .2/Al2O3/Pt-TE structures with an anatase phase in the titanium dioxide layer, the resistance of the much thicker (6 times) titanium oxide film is connected in series with the resistance of the active aluminum oxide film. This gives a gentler slope of the I-V characteristics in the region of the abrupt increase of the current. This, in turn, makes it possible to implement the analog gradient tuning mode in two-layer structures, blurring the switching threshold to the range of about 0.5–1 V. Thus, gradually increasing the amplitude of the voltage pulses, applied to the two-layer structure, provides a gradient change of conductivity, which, in this case, is not always associated with the varying concentration of oxygen vacancies in the aluminum oxide film  the non-linear I-V characteristics of Al2O3 determined by the mechanisms of electron transport mentioned earlier, and (ii) the linear I-V characteristics of the titanium dioxide layer playing the role of ballast resistance. Decreasing the ballast resistance, caused by the increasing concentration of oxygen vacancies in the titanium dioxide layer, will lead to a steeper slope in the non-linear part of the I-V curve of the two-layer structures, which is in good agreement with our experimental results and model calculations.Thus, we assume that when positive polarity is applied to the upper electrode of two-layer structures, two processes are simultaneously observed: the migration of hydroxonium ions from ALD-grown Al2/Al2O3/Pt-TE structures limits the range of the tuning by the value inherent to the high-resistance state of the titanium dioxide layer. As a rule, the transition to this state indicates an irreversible modification of the aluminum oxide layer. At the same time, the gradient switching in such structures remains possible, and it is similar to that observed in single-layer Pt-BE/TiO2/Pt-TE structures with the amorphous titanium dioxide layer  dopant. The oxidation of the Cu electrode at the Al2O3/Cu–TE interface provides a higher migration rate of Cu ions due to the lower Cu–O bond energy compared to that of the Cu–Cu metallic bond (1.5 vs. 2.0 eV)  is set by the concentration of oxygen vacancies, determined by the ratio between positively charged hydroxonium cations and negatively charged oxygen-containing groups at the interface with the second functional layer. Moving further along this line, we can assume that the addition of ions with a lower activation energy of the migration in the oxide layers of the structure (compared to that of the oxygen vacancies) should not only change the resistive state, but also simulate the excitation dynamics inherent to neuronal membranes. Indeed, the use of copper and platinum as electrode materials in combination with the oxide layers, containing OH groups, leads to the generation of EMF of up to 600 mV . If we ceristics  that mim 2.0 eV) .2/Al2O3/Cu-TE structures is explained by the different activation energies of migration for the ions involved in the formation of the resistive state.The appearance of the characteristic part of I-V curves with negative differential resistance is experimentally observed on the branch of I-V curves for a low-resistance state corresponding to the polarity of the reset process  at volta2/Al2O3/Cu-TE structures with the ionic mechanism of switching of the resistive state, two mandatory conditions for bioelectrogenesis are met: (1) existence of EMF, which is equivalent to the concentration gradients of electrolytes at the cell membrane, and (2) different activation energies of migration for ions of different types, which take part in the formation of the resistive state .Thus, we may conclude that in memristive Pt-BE/TiOThe results of modeling and experimental studies of resistive effects in memristive structures, composed of thin layers of titanium and aluminum oxides, indicate that the structure of oxide layers is responsible for the physical mechanism of analog resistive switching. Interestingly, despite the active layer, which governs the change of the state and its range, being the alumina thin film, the switching pattern is mainly determined by the properties of the titanium oxide layer. For example, the presence of conducting anatase phase in amorphous titanium dioxide ensures the electronic nature of the switching in the range of seven orders of magnitude, while the use of high-resistance amorphous titanium dioxide leads to the predominance of ionic processes in the observed resistive effects. In addition, applying the active electrode materials in these structures opens a way to use the same memristive composition both for emulating synaptic connections and as neurons themselves in neuromorphic architectures. The latter is ensured by the peculiarities in the drift of active electrode ions and oxygen-containing groups involved in the formation of oxygen vacancies in the functional layers of memristive compositions, setting together the type of I-V curve characteristic of excitable membranes.Thus, the use of multilayered oxide memristive compositions makes it possible to move from the circuit implementation of the execution algorithms at the hardware organization of artificial neural networks toward a more complete utilization of the functionality of behavioral materials. In the future, such an approach will allow us to develop more flexible neuroelectronic analog architectures by applying the multifunctional element base. At the same time, the possibility of transition to the electronic mechanism of resistive switching in the memristive systems under consideration provides the firm background for the implementation of digital approaches to the construction of neuromorphic architectures.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.NA and ER: conceptualization and visualization. ER: modeling. DM: technology and methodology. NA, OV, and VL: validation. NA and DM: investigation. NA and OV: writing—original draft preparation. DM and OV: writing—review and editing. VL: supervision. All authors have read and agreed to the published version of the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The results show that the utilization of MTS reduces the slump of MTSC to a certain extent. When the MTS content is lower than 40%, the gypsum introduced by MTS and C3A in cement undergoes a hydration reaction to form ettringite, which decreases the number of pores with a diameter less than 0.1 mm and promotes strength development in MTSC. Additionally, when the MTS content exceeds 40%, the large amount of gypsum reacts to form more ettringite. The expansive stress generated by the ettringite severely damages the pore structure, which is not conducive to the mechanical properties of MTSC. In addition, the leaching of hazardous substances in MTSC is insignificant, and the incorporation of cement can effectively reduce the risk of leaching hazardous substances in MTSC. In summary, it is completely feasible to use MTS to replace RS for concrete preparation when the substitution rate of MTS is less than 40%, with no risk of environmental pollution. The results and adaptation in the concrete industry can reduce the carbon footprint, which is in line with the current trend in civil and materials engineering.In this work, manganese tailing sand concrete (MTSC) was prepared using manganese tailing sand (MTS) in replacement of river sand (RS) to alleviate the shortage of RS resources and achieve clean treatment and high-value resource utilization of manganese tailing stone. The effects of MTS content on the slump, mechanical strength, air void characteristics, hydration products and micromorphology of MTSC were studied experimentally. The leaching risk of harmful substances in MTSC was also explored by testing the concentration of Mn In 2020and (RS) . TherefoIn response to these problems, many studies have been conducted by relevant researchers ,6,7. BleMoreover, as the world’s largest producer, consumer and exporter of manganese metal, China accounts for more than 97% of the global production of manganese metal ,13. WithIn summary, RS, as one of the main raw materials for concrete, has led to frequent geological disasters due to large-scale RS mining as concrete usage has increased dramatically. In addition, with the rapid development of the manganese industry in China, the accumulation of a large amount of manganese tailing stone seriously occupies the land and has the risk of environmental pollution. Therefore, it is urgent to explore the alternatives of river sand and the resource utilization of manganese tailing stones. Based on these, this paper first made manganese tailing stone into manganese tailing sand (MTS) and then used MTS to partially or fully replace river (RS) sand to prepare manganese tailing sand concrete (MTSC). With the content of MTS as a variable, the effect on the slump, mechanical properties, pore characteristics and microstructure of MTSC was studied. The influence of MTS on the hydration of concrete and the risk of leaching harmful components were discussed. A suitable replacement rate of MTS without losing the basic properties of concrete was proposed. The results of the study not only provide a new way for the clean and high-value utilization of manganese tailing stone but also offer a new solution for the transitional consumption of RS.3, water absorption is 0.68%, and mud content is less than 1%. The concrete mixing water was domestic water.The cement used in this study was P·O 42.5 ordinary Portland cement. The main properties and chemical compositions of cement are shown in The preparation process of MTSC is shown in (1) Slump: The slump test of MTSC was carried out according to “the national standard of the People’s Republic of China: Standard test methods for the performance of ordinary concrete mixes (GB/T 50080-2016)” .(2) Strength: The flexural strength (loading rate of 0.2 kN/s), compressive strength (loading rate of 0.5 MPa/s) and splitting tensile strength (loading rate of 0.05 MPa/s) of MTSC were tested by using a microcomputer-controlled constant loading pressure testing machine K was introduced to quantify the strength contribution of MTS. Assuming that Equation (1) holds, the strength of MTSC after mixing with x content MTS is σ, and the strength contribution K of MTS can be calculated according to Equation (3) by combining Equations (1) and (2).K is strength contribution value; x is the dosage of MTS; σ0 is the strength of concrete without MTS, MPa; σe is the strength contribution of unit MTS, MPa; σ is the strength of concrete mixed with x content MTS, MPa;Additionally, in order to investigate the strength effect of MTS in MTSC, the strength contribution value (3) Pore structure: The MTSC sample with an age of 28 d was cut into slices, and then the uneven surfaces of these slices were polished using a grinding machine. Then, the surfaces of the specimen were coated with black ink, and the mixture of ZnO and petroleum jelly was applied again after the surfaces of the specimen were dried. The excess coating on the surfaces was wiped off when the holes on the surface of the specimen were completely filled. The hardened concrete, porous structure analyzer  was used to analyze the characteristics of the pore structure of MTSC;−1 for 10 h and left for 14 h. Finally, the supernatant was taken to test the content of Mn2+ by using the water quality tester .(4) Leaching of harmful substances: The leaching test of MTSC was carried out by the horizontal oscillation extraction process. After crushing and grinding the samples to a particle size of less than 0.075 mm, then 5 g of the sample was placed into a beaker and stirred for 2 min in a magnetic stirrer with a solid–liquid ratio of 1:10. The sample was then placed on a constant temperature shaker and shaken at a frequency of 160 min2 environment) for the composition of the physical phases and mineral phase alterations.MTSC specimens were crushed after curing to 28 d. Samples with a particle size less than 5 mm were taken, and hydration was prevented by using isopropyl alcohol. MTSC flake samples were taken out, and their hydration products were observed using scanning electron microscopy (SEM). The remaining samples were ground in a mortar and passed through a 0.075 mm sieve. The samples were analyzed by X-ray diffraction  and thermogravimetry . Compared to the concrete without MTS, the incorporation of MTS increases the peak strength of ettringite and decreases the peak strength of portlandite. The results are consistent with the results of TG/DTG curves. It is noteworthy that the gypsum appears in MTSC-10, which indicates that the partial gypsum does not participate in the cement hydration reaction when all RS is replaced by MTS.The XRD patterns of MTSC-0, MTSC-3, MTSC-4 and MTSC-10 are shown in In conclusion, the TG/DTG curves and XRD patterns of MTSC show that the increasing dosing of MTS results in the growth of gypsum content, which promotes the formation of ettringite in MTSC. However, the reduced production of portlandite in MTSC is not beneficial to the development of mechanical properties. Therefore, the optimum content of MTS in MTSC should not exceed 40%.The SEM images of MTSC-0, MTSC-3, MTSC-4 and MTSC-10 are shown in In addition, compared with MTSC-0, the flaked portlandite content in MTSC-3 and MTSC-4 is slightly reduced. The fewer portlandite is generated in MTSC-10. This indicates that the incorporation of excessive MTS reduces the amount of portlandite. This is in full agreement with the results of TG/DTG curves and XRD patterns. Moreover, it was further verified that the preparation of concrete by replacing RS with MTS in an appropriate amount could promote the development of concrete strength. Therefore, the purpose of RS resource saving was achieved.3A in the cement [The substitution of RS by MTS for concrete preparation is an economical and resource-saving method . Therefoe cement ,40. The e cement , which c3A in cement by hydration to form ettringite. However, when the content of MTS is low, the ettringite generated by the reaction between gypsum and C3A fills the voids of MTSC, which makes its structure dense and enhances the mechanical properties of MTSC, while when the content of manganese tailing sand is high, the reaction generates too much ettringite produces expansion stress, which leads to the strength of MTSC decreasing. Therefore, the preparation of MTSC by replacing RS with an appropriate amount of MTS not only does not reduce the strength of concrete but even improves it. Additionally, the excessive amount of MTS is not suitable to replace RS for preparing concrete.The abovementioned studies showed that compared to RS, MTS contains gypsum, which can react with C2+ in MTS and MTSC. It can be seen that the leaching concentration of Mn2+ in MTS is 4.27 mg L−1, which meets the requirement of Mn2+ concentration of less than 5 mg L−1 in the National Standard of the People’s Republic of China: Sewage Discharge Standard (GB/T 8978-1996) [2+ in MTSC prepared by using MTS also meets the requirements. This is consistent with the results in 2+ in MTSC is significantly lower. This is primarily because cement hydration creates an alkaline environment for Mn2+ solidification, allowing Mn2+ to be converted into stable MnO(OH)2 precipitation. Moreover, Mn2+ may replace part of Al3+ in the C-S-H gel during cement hydration to form a stable structure, thus reducing the leaching of Mn2+. In addition, the dense structure of MTSC also prevents the leaching of Mn2+, making the leaching concentration of Mn2+ in MTSC dramatically lower than that in MTS. Therefore, the use of MTS for concrete preparation can realize the clean treatment of MTS and reduce the risk of environmental pollution from MTS.The chemical compositions of MTS  indicate78-1996) . TherefoIt is not feasible to use MTS to replace all RS for concrete preparation. However, when the substitution rate is less than 40%, MTS has little effect on the slump and mechanical properties of concrete and even has a positive effect. There is also no risk of environmental pollution in MTSC.Moreover, the preparation of concrete with MTS realizes the high-value resource utilization of manganese tailing stone and alleviates the problem of shortage of RS resources. As the MTSC (lower than 40% substitution) exhibited good workability and mechanical properties, it may be recommended for all construction activities. The results are not only in line with the concept of carbon reduction in the concrete industry but also with the current trend in civil and materials engineering.Although this work provides guidance for the application of MTS in concrete, the effect of MTS on the long-term performance and durability of concrete needs to be further investigated.2+ in MTSC was also examined. Based on the results from this study, the following conclusions can be drawn:In this paper, the effect of MTS content on the properties and microstructure of MTSC was investigated. The basic properties of MTSC were analyzed by the slump, flexural strength, compressive strength and splitting tensile strength experiments. The pore structure characteristics and microstructure of MTSC were characterized by the hardened concrete pore structure analyzer, TG/DTG, XRD and SEM. The leaching concentration of Mn(1) When the content of MTS is lower than 40%, the decrease in the concrete slump is insignificant, but when the dosing of MTS exceeds 40%, the slump of concrete decreases obviously;(2) Compared with MTSC-0, the flexural and compressive strength of MTSC in the early stages (3 d and 7 d) can be improved effectively when the amount of MTS is less than 40%, but the flexural and compressive strength at 28 d not be improved obviously. The flexural and compressive strength of MTSC can be significantly reduced when the amount of MTS is more than 40%. Moreover, with the increase in MTSC content, the splitting tensile strength of MTSC at 28d first remains constant and then decreases;(3) The incorporation of MTS can reduce the number of pores with a diameter of less than 0.1 mm in concrete and make the pore distribution uniform. However, the excess MTS can cause the number of large pores with a diameter greater than 0.2 mm in concrete to rise sharply. Additionally, the air content in hardened MTSC shows a trend of decreasing and then increasing with the increase in MTS content;(4) MTS can be hydrated with cement mainly due to the presence of gypsum. With the increase in MTS content, the amount of ettringite in MTSC increases. In addition, excess ettringite interacts with each other to form expansion stress and squeeze the pores, which is not conducive to the development of concrete strength;2+ in all MTSC is lower than 5 mg/L. Moreover, cement-based materials can reduce the risk of leaching hazardous substances. Therefore, there is no risk of environmental pollution in the preparation of MTSC by using MTS.(5) The leaching concentration of Mn


Chemical modification of branched polyesterurethanes with R,S-PHB and their physical blending with small amounts of PLA and St resulted in a slow but progressive degradation of the samples.A very important method of reducing the amount of polymer waste in the environment is the introduction to the market of polymers susceptible to degradation under the influence of environmental factors. This paper presents the results of testing the susceptibility to degradation in soil of branched polyesterurethane (PUR) based on poly , modified with poly (PLA) and starch (St). Weight losses of samples and changes in surface morphology  with simultaneously only slight changes in molecular weight (GPC), chemical structure (FTIR and  Managing the environment and its condition requires taking steps to reduce the quantity and to change the quality of the generated waste. One of the most important methods of reducing the amount of polymer waste is the introduction to the market of products made of biodegradable polymers, which will decompose after the end of their service life under the influence of environmental factors. Polyurethanes (PURs) are such polymers, widely used in many industries. Currently, in Europe, the same amount of PURs (in various forms) is produced as the popular polyethylene terephthalate  . At the Polymer biodegradation is the consequence of a number of physical, chemical and biological processes related to the destruction of polymers . The finAs a result of the degradation, the polymer chains are shortened (the molecular weight of the polymer is reduced) and their fragments are eliminated, and consequently the weight of the polymer samples is reduced. The enzymatic degradation process itself takes place on the surface of the samples, in contrast to the chemical hydrolysis which runs throughout the sample bulk. Under favorable conditions for their development , microorganisms secrete enzymes that initiate the depolymerization process, leading to the final decomposition of the polymer into monomers or to the formation of other low-molecular compounds, which are then absorbed by the microorganisms as nutrient material . Severald,l-lactide) (PLA), poly(β-hydroxybutyrate) (PHB) and poly(ε-caprolactone) (PCL) are considered to be biodegradable thermoplastic aliphatic polyesters [The synthesis of PUR from compounds containing ester groups as well as its physical modification with polyester gives hope for obtaining a material susceptible to enzymatic hydrolysis. Among all polyesters, poly, gel permeation chromatography (GPC-MALLS), differential scanning calorimetry (DSC), scanning electron microscope (SEM), optical microscopy (OM) and a goniometer (static water contact system).Thus, the main reason for the research described in this publication is to investigate the susceptibility of branched PUR materials modified with polyesters, R,S-PHB and PLA, and starch for degradation in anthropological soil. This paper is a continuation of our previous research on determining the susceptibility of these materials to degradation in a hydrolytic and oxidizing environment . DegradaPoly diol  was synthetized via polymerization of β-butyrolactone , using anionic ring-opening polymerization, initiated by 3-hydroxybutyric acid sodium salt/18-crown-6 complex , at room temperature and terminated with 2-iodoethanolor 2-bromoethanol  [n 1900) in the structure of soft segments and synthetized by the two-step method in the presence of Tin(II) octanoate  and N,N’-dimethylformamide  [triol)  and 85 or 75 wt.% poly(ε-caprolactone) diol (PCLdiol) , respectively, in the soft segments (12MDI)  and 1,4-butanediol  . A simplified scheme of the synthesis of polyesterurethanes and their blends is shown in dl-lactide) (PLA)  and, in the case of polyurethane with a higher R,S-PHB content, also with starch (St)  were prepared. A schematic representation of the polyesterurethane chains and biopolymer inclusions is shown in Two branched polyesterurethane films differing in the amount of R,S-PHB Mn 00 in thesegments . Hard poBacillus spp. [The horticultural soil used for the study was currently not being cultivated, and therefore was not fertilized with natural or synthetic fertilizers. It was taken from a garden in the northern part of Poland , with a warm, temperate transitional climate. The soil parameters  before and after the addition of vermicompost are given in lus spp. ). As che1HNMR, GPC, DSC, SEM and OM analysis. Moreover, the change in the contact angle of the sample surface after incubation in the soil was determined.Samples (with a thickness of 1.0 ± 0.01 mm) were cut from the tested films in triplicate for each collection and then placed in a vacuum extractor with a drying bed for 6 h at 40 °C. The mass of individual samples was determined on an analytical balance. Plastic containers were prepared for each week of incubation, filled with soil to the height 3/4 of the container and the samples were placed to a depth of about 1 cm . The soi−1 and a scanning range from 600 to 4000 cm−1 were applied, and 16 scans were taken for each measurement.Attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) was used to determine the characteristic groups of polyurethanes. FTIR spectra were recorded with an attenuated total reflection  mode on a Nicolet iS 10 spectrometer  with a diamond cell. A resolution of 4 cm1H NMR spectroscopy of PURs samples before and after 36 weeks of incubation was recorded using a Bruker-Advance spectrometer  operating at 600 MHz with Bruker TOPSPIN 2.0 software using CDCl3 as the solvent and tetramethylsilane (TMS) as the internal standard. Spectra were obtained with 128 scans, an 11 μs pulse width and a 2.66 s acquisition time.Nuclear magnetic resonance w/Mn) of the polymers were determined using gel permeation chromatography (GPC-MALLS) with a differential refractive index detector Dn-2010 RI  and a multiangle laser light scattering detector DAWN EOS . GPC was performed using the following set of columns: GRAM gel guard, GRAM 100 Å, GRAM 1000 Å and GRAM 3000 Å . The measurement was made in DMF supplemented with 5 mmol/L LiBr at 45 °C with a nominal flow rate of 1 mL/min. The sample solution was filtered prior to injection using a syringe PTFE filter with a pore size of 0.22 µm . The polystyrene standards  with narrow molecular mass distribution were used to generate a calibration curve. The results were evaluated using PSS Win GPC Unity software from Polymer Standard Service . The average molecular weight and molecular weight dispersity  analysis was conducted with a Setaram thermal analyzer . Indium and lead were used for calibration. Specimens (with mass of about 8 mg) were sealed in aluminum pans and scanned from 20 to 200 °C, with a heating rate of 10 C/min. All experiments were carried out in a dry flow of NA scanning electron microscope (SEM) was used to investigate the structure and morphology of sample surface before and after incubation. Sample surfaces were analyzed by a Quanta FEG 250 SEM . The SEM was equipped with an ET secondary electron detector. A total of 10 nm of gold layer was spattered on the surface to avoid charging of the sample. The images were taken at the sample surface in multiple places to confirm sample uniformity. The acceleration voltage was kept at 10 kV during the measurements and was constant.Optical microscopy (OM) micrographs were taken using a Nikon microscope ALPHAPHOT-2 YS2-H (Japan) connected with Delta Optical DLT-Cam PRO 6.3MP USB 3.0. The micrographs were collected under reflected and transmitted light.Static water contact angle measurements were carried out using the DataPhysics OCA 15EC contact angle system  at ambient temperature. A 2 mL distilled water drop was used for each measurement and a photo of the drop was taken after 0, 1 and 3 min from immersing the drop on the sample surface. At least five measurements were made for each different system.Macroscopic observations indicate the gradual degradation of each type of material with the time of exposure to soil. A characteristic feature is yellowing and browning of the surfaces of the tested samples . There wEnzymatic hydrolysis is a heterogeneous process. The relatively high molecular weight of the enzymes hinders their action in the bulk of the polymer, hence the changes occurring first on the sample surface . First, −1), as well as I, II and III amide bands, respectively, at around 1720 cm−1, 1523 cm−1 and 1240 cm−1. The band at 1720 cm−1 is a multiplier of superimposed bands resulting from absorption of C=O groups from esters building soft segments and from urethane [−1 and is visible as a bulge on the right side of the band (2 and CH3) are at around 2933 and 2863 cm−1. The absence of a band indicating the presence of OH groups in the ATR-FTIR spectrum of the PUR 20/5+St sample may be due to the low amount of St in the composite or its presence deep inside the sample, not on the composite surface.FTIR was used to study the structural changes occurring in PURs and their blends after degradation in soil. urethane . The urethe band B. The al−1 (stretching of C=O in ester groups) indicates the presence of hydrogen-bonded ester groups. However, in the case of PUR 20/5 + PLA, there is a clear shift of these bands towards higher wavenumber values, indicating the presence of free carbonyl groups  and CO (1520 and 1720 cm−1) groups indicates low biodegradation in the urethane region [−1, associated with stretching vibrations of the absorption system of the C–O–C (ester), indicates the biodegradation of ester parts of PURs materials after the action of biotic factors . The intensity of peaks at 1045 and 1195 cm−1 increased, while the peak around 1095 cm−1 decreased after 36 weeks in soil, which is especially visible in the case of PUR 20/5 + PLA  of PUR 20/5 and its blend. The molecular weights of all polyurethane materials are similar. Moreover, as can be seen, the value of Mn practically did not change after incubation in soil, only in the case of PUR 20/5 + PLA did it slightly decrease. These observations are consistent with only the slight structural changes observed in the FTIR spectra. This change is incomparably smaller than when this material was subjected to hydrolytic degradation [n reduction, the Mw value and consequently the molecular-weight dispersity of the tested polymer materials changed. Sikorska et al. stated that when the bonds near the center of the polymer are more stable than those near the ends of the chain, then Mw/Mn increases above the value of 2 [w/Mn was observed. It indicates changes in the length of the polyurethane chains, connected with their cutting under the influence of soil conditions. This leads to shorter chains, but molecular weight is too high for these chains to be washed out of the sample, resulting in an increase in the dispersity of the polyurethane. On the other hand, a reduction in dispersity index may indicate elution of short polymer chains, as in the case of PUR 20/5 + PLA and PUR 20/5 + St. The addition of both biopolymers to the PUR 20/5 matrix probably resulted in the loosening of the chain network and easier elution of low-molecular weight fractions during incubation in the soil, which resulted in the reduction of molecular-weight dispersity. However, the visible weight loss of the samples   . This caPUR20/5)  than in PUR20/5) . The infPUR20/5)  appearedAs is shown in Both modifiers are biodegradable, despite PLA being a hydrophobic material . In cont12MDI after 45 days of degradation in the compost [Changes in the contact angle can be used to assess the influence of the degradation environment on the morphology of the surface layer of the material and the progress of the degradation process . It is oAliphatic, branched polyesterurethanes based on R,S-PHB and additionally modified with PLA and St were obtained and exposed to the soil. The study of susceptibility to degradation was carried out by burying the samples in the anthropological soil in conditions simulating the average moisture and temperature in Poland in the months from April to October. This experiment allows us to predict the behavior of the investigated polymer samples after their disposal in landfills. However, as Podzorova and Tertyshnaya point out, placing the samples in the ground under natural conditions meant that they are additionally exposed to temperature changes, including freezing and high temperatures up to 40–50 °C, as well as periodic flooding with water . This isw/Mn ratio changed, which indicates: (i) chain cutting to shorter molecular weights—in the case of the pristine PUR; (ii) elution of shorter chains—in the case of blends with PLA and St. The FTIR and 1HNMR spectra indicate only slight hydrolysis of the ester groups and interference with the interactions of the urethane bonds. It can be seen, however, that at this stage of the investigation, the presence of small PLA and St inclusions that have been washed out of the PUR matrix has a greater influence than the presence of R,S-PHB. Probably the extension of the time of exposure to the soil of the samples would cause the hydrolysis of amorphous R,S-PHB and thus also the degradation of PUR. The results of this study show that blending the branched PUR based on R,S-PHB with only a small amount of degradable PLA and St allows slow but gradual (bio)degradation of these materials when they enter a municipal or wild landfill, where conditions for the degradation of polymers are much worse than in industrial compost.Burying the samples in the soil for 36 weeks resulted in the loss mass of the samples (up to 7.9 wt.%) and changed their surface morphology. However, only slight changes were found: in the molecular weight and dispersity of these polymers, in the chemical structure and in thermal properties. The molecular weight practically did not reduce, while the M


Since the effect of the facet braiding phenomenon, the display quality of reconstructed image degrades with increasing depth of field in tabletop three-dimensional light-field display. Here, to analysis the facet braiding, the imaging process of the tabletop 360-degree three-dimensional light-field display based on conical lens array is mathematically modeled. A viewpoint-fitting encoding algorithm is proposed to reduce the effect of the facet-braiding phenomenon and improve the range of depth of field, which is optimized to form the best synthetic encoded image by fitting the reconstructed image seen by the simulated human eye to the parallax image captured at the corresponding location. The effectiveness of the proposed optimization algorithm is verified by simulation analysis and optical experiments, respectively. In the experiment, the clear depth of field range of the display system is increased from 13 cm to 15 cm, and the visualization effect of the reconstructed three-dimensional image is enhanced. As the great innovation of three-dimensional 3D) display technology and the urgent needs of information display, the research of tabletop 3D display has attracted more attention and made great progress ,2,3. TheD displayInsufficient depth of field seriously limits the development of the tabletop 3D light-field display , and theIn this paper, using the tabletop 360-degree 3D light-field display system based on the conical lens array as the hardware, the effect of the facet-braiding phenomenon lending to depth of field limitation is dissected. By mathematically modeling the imaging process of the 360-degree tabletop 3D light-field display based on conical lens array, a viewpoint-fitting encoding algorithm is proposed to significantly reduce the facet-braiding phenomenon and improve the depth of field, which is optimized to form the best synthetic encoded image by fitting the reconstructed image seen by the simulated human eye to the parallax image captured at the corresponding location. In the experiment, a high-quality tabletop 360-degree 3D light-field display system with high resolution and large depth of field is realized. The clear depth of field range of the display system is increased from 13cm to 15cm by means of the proposed optimization algorithm, and the visualization effect of the reconstructed 3D image is enhanced.To understand the facet-braiding phenomenon more intuitively and naturally, the previous 360-degree tabletop 3D light-field display system is drawn, which is composed of the holographic functional screen (HFS), the conical lens array, LCD panel and the collimating backlight array , as showActually, the viewed 3D image is spliced by a serious of sub-images observed through each a lens. The reference plane is the conjugate plane of the lens array. The pixels on the liquid crystal panel will be imaged on the reference plane, and the reconstruction plane is the actual depth plane of the captured 3D object. If the object is far away from the reference plane in the pickup stage, the sub-images viewed by human eye will not be spliced correctly in the display stage. This is called facet-braiding phenomenon ,25, whicAs shown in M2 sub-areas, and each sub-area also corresponds to the position of the camera in the pickup process. According to M is the number of pixels in the elemental image along the horizontal or vertical direction. S (size of [2MUV × 1]) denotes the synthetic coded image loaded on the LCD panel. The matrix W (size of [γ2M2UV × γ2M2UV]) represents the light modulation of the lens array, which is the parallax shift of the lens to solve the depth reversed. The matrix V different facet images from the U × V lens array. The facet image is composed of γM × γM pixels covered under a lens. γ is the sampling factor, which ranges from 0 to 1/2. According to the geometric relationship in P is the diameter of the conical lens, H represents the distance between the viewing plane and the HFS, and L represents the distance between the HFS and the conical lens array. The inner ring with To reduce the deterioration of displayed image caused by the facet braiding phenomenon, the 360-degree tabletop light-field display system based on the conical lens and HFS is mathematically modeled. According to the modeled display system, each viewpoint perspective based on different positions of the observer in the space can be accurately obtained. In terms of system structure and the arrangement of viewpoints, the viewing area is divided into S can be fitting by combining the reconstructed image S can be calculated in Equation (3).ρ represents the “distance” between the reconstructed image S is set to L2 norm. Therefore, the following equation can be obtained by bringing Equations (1)–(3).According to the mathematic analysis and the synthetic coded image, the viewpoint perspective S is solved using the gradient descent method, and thus the high-quality reconstructed 3D image with minimal facet braiding is realized. In addition, the coded image [S to improve the convergence efficiency of the proposed algorithm. The core idea of the proposed algorithm can precisely match the correspondence between pixels on the display panel and viewpoint information without additional hardware cost, weakening the deviation effect of pixels on the reconstruction plane farther away from the imaging plane and improving the imaging quality within the reconstruction plane of depth of field, thus expanding the range of the ultimate depth plane viewed by the human eye.Due to the solution of the above indeterminate equation is uncertain, the optimized synthetic image ed image  is adoptRelying on the previously demonstrated tabletop 360-degree 3D light-field display system, the viewpoint-fitting coding optimization algorithm is combined to expand the rang of depth of field and improve the display quality. To further evaluate the quality of the reconstructed 3D images, the following simulations were performed to compare the results before and after the algorithm optimization. It is well-known that the reconstructed display image observed by human eye is formed by stitching a series of sub-images in each lens unit. The effectiveness of the proposed algorithm was evaluated by introducing the structural similarity index measure (SSIM) to calculate the value of the viewpoint perspectives with different angles. As shown in To verify the effectiveness of proposed method, relevant experiments are carried out. In the tabletop 360-degree 3D light-field display system, the size of the LCD panel used to load the synthetic encoded image is 27 inch with a resolution of 3840 × 2160. The number of LEDs, Fresnel lenses, elemental images and conical lenses are the same. The fixed structure of the aluminum plate using a computer numerical control machine to uniformly punch 46 × 26 holes with a diameter of 10 mm and a distance of 13 mm between the centers of adjacent holes, and put the conical lens array into the holes in turn. A HFS with a 5° diffusion angle is used to eliminate the gap between adjacent conical lenses. The detailed parameters of the system are shown in With the advantages of annular viewing of 3D scenes and intuitive 3D visual perception, the electronic map is one of the most ideal directions for tabletop 3D light-field display. The synthetic encoded image loaded on the LCD panel is optimized by the proposed viewpoint-fitting encoding algorithm, different perspectives along the annular direction of the 3D electronic map are shown in Another prominent application of the tabletop 3D light-field display is for medical diagnosis and biomedical education. In a tabletop full-parallax 3D light-field display based on lens array, the facet-braiding phenomenon leads to blurred images in a large depth of field plane, which is a major factor limiting the depth of field. In this paper, the imaging process of the tabletop 360-degree three-dimensional light-field display based on conical lens array was mathematically modeled to analyse the facet braiding phenomenon. A viewpoint-fitting encoding algorithm was proposed to reduce the effect of the facet-braiding phenomenon and improve the range of depth of field. The effectiveness of the proposed optimization algorithm was verified by simulation analysis and optical experiments, respectively. With our proposed algorithm, a tabletop 360-degree 3D light-field display system with large depth of field was experimentally demonstrated to present the reconstructed high-quality 3D images of the military and medicine. The clear depth of field range of the display system increased from 13 cm to 15 cm, and the visualization effect of the reconstructed 3D image was enhanced.


In this paper, experiments and finite element analysis methods were adopted to study the flexural performance of shape memory alloy hybrid composites (SMAHC). The effect of embedding content and position of shape memory alloy (SMA) wire on the flexural properties of composite laminates was analyzed, and the optimal content and position of SMA wire were obtained. The optimal number of SMA wires for SMAHC laminates (B-2) is four. Compared with GFRP laminates, the flexural modulus of B-2-4 laminates increases by 5.19%, while the strength decreases by 5.76% on average. The finite element model of the SMAHC laminate was established by using ABAQUS finite element analysis software, and the validity of the model was verified by the comparison between the simulation results and the experimental results. The microscopic morphology results show that the weak interface between the matrix and SMA has a certain influence on the flexural performance of SMAHC specimens. Smart materials and structures have brought forth a paradigm shift in design, mostly to the fields of structural engineering, robotics, and aerospace, due to which the demand for highly functional and lightweight, adaptive systems is continuously growing ,2. ShapeThe fiber-reinforced resin-based composite material is embedded with SMA; the composite material can acquire the ability to adapt to the environment under the control of the induction unit ,6. Due tMany scholars have systematically studied the shape memory effect. Lagoudas and Tadjbaksh  studied In terms of superelastic research, Viet and Zaki  propose Debski  and WysmRecently, research interests in using superelasticity SMAs have extended to civil engineering, where particular effort was devoted to the mitigation of seismic effects on structures . Fang etIn this paper, the influence of the position and content of SMA on the flexural properties of SMAHC laminates was studied by numerical simulation and experimental methods. The effectiveness of the model was verified by comparing simulation results with experimental data, and the influence mechanism of SMA on the flexural properties of SMAHC laminates was further revealed.2 is used as a reinforcing material, bought from Tongxiang Mengtai reinforced composite material Co., Ltd. Superelastic Nitinol with a nickel content of 55.9% has a diameter of 0.2 mm, purchased from Jiangyin [The matrix is a polymer mixed with thermosetting epoxy resin, accelerator and curing agent. The three materials are ethylene oxide resin 411, methyl ethyl ketone peroxide, and cobalt naphthenate, and the mixing ratio is 1:2:0.5%. A unidirectional glass fiber cloth with a thickness of 0.2 mm and a surface density of 200 g/mJiangyin ,35. The There are three distinct phases in in curve ,38,39,40in curve . Vacuum-The three-point-bending test specimens of SMAHC were prepared according to the ASTM-D790 standard. The INSTRON 4505 universal testing system was used to conduct three-point-bending experiments on composite laminates with different SMA embedment contents and embedment positions at room temperature . Five spP is the load at a given point on the load–deflection curve, L is the length of the support span, b is the width of the tested specimen, and d is the depth of the tested specimen.The flexural stress corresponding to any point on the load–deflection curve can be calculated using the following Equation (1):D is maximum deflection of the center of the beam, L is support span, and d is depth.Nominal fractional change in the length of an element of the outer surface of the test specimen at midspan, where the maximum strain occurs. It may be calculated for any deflection using Equation (2):Finite element software ABAQUS was used to establish a model to analyze the bending performance of SMAHC. The three-dimensional continuum element C3D8R was used to mesh glass fiber-reinforced composites. The meshing of composite laminates is given in To predict the damage of composite materials, such as matrix tensile failure, matrix compression failure, fiber tensile failure and fiber compression failure, a composite material damage model based on Hashin ,44 was aFiber tension Fiber compression S13 and S12, respectively.Matrix tension and compressionThe surface-based cohesive contact model in ABAQUS was used to simulate the composite effect of laminates ,46,47. TThe convergence of the numerical simulation of the model is tested. The number of elements in the original model is 50,000, and the number of elements in the new model is 100,000. The new model only adds elements in thickness. The comparison between the stress–strain curve obtained from the bending test of GFRP laminates and the simulation results is shown in The optimal number of SMA wires for SMAHC laminates (B-2) is four. Compared with GFRP laminates, the flexural modulus of B-2-4 laminates increases by 5.19%, while the strength decreases by 5.76% on average. The flexural properties of B-2-6 and B-2-10 laminates decrease more obviously, and the weak interface between fiber and matrix is the main reason for the degradation of the flexural properties.The microstructure shows that the material difference between SMA and matrix forms a weak interface, which produces microcracks and expands rapidly during the loading process. The interface debonding failure results in matrix delamination and the final specimen failure. The weak interface between the matrix and SMA increases with the increase of the number of SMA wires, which is convenient for the formation of matrix delamination damage. The main failure modes of SMAHC composites are delamination and debonding, and this failure mode has an obvious influence on the mechanical properties of the composites.The finite element models of GFRP and SMAHC (B-2-4) laminates were established and compared with the experimental results. The numerical prediction results were in good agreement with the experimental results. The errors between the simulation results of GFRP laminates and the experimental results of flexural performance were 2.56% and 10.43%, respectively. The errors of experimental results and simulation results of the flexural performance of SMAHC laminates (B-2-4) are 4.38% and 2.34% respectively, which meet the accuracy requirements and verify the validity of the model.In this paper, the flexural behavior of SMAHC laminates was studied experimentally and numerically. The experimental results and simulation results were compared to verify the validity of the model. The main conclusions obtained were made as follows: