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Made available in DSpace on 2022-05-01T09:47:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Non-biodegradable petroleum-based plastics are still widely used by the food industry for packaging applications and, due to that bio-based raw materials such as starch, have been attracting growing interest from the packaging industries as a biocompatible alternative material. During the industrial processing of potato, a large amount of residual starch is produced from the washing of the raw material. Starch-like biopolymers have been proposed for the formulation of biodegradable materials. The application of starch in the packaging production depends on chemical, physical and functional properties to form gels and films. The aim of this study was to develop packaging films made from potato processing residual starch combined with polar organic solvents (glycerol and acetic acid) that can be fully obtained from renewable sources. The characterization of the material obtained was performed evaluating the microbiological stability, mechanical properties, formed bonds and barrier characteristics and, in order to demonstrate the real application in fruits preservation the material was direct applied into papaya fruits (Carica papaya) by the immersion method. The present study exhibits the potential of starch residual from potato industrialization to manufacture packaging films. The films achieved the expected results for microbiological analysis, water vapor permeability and Fourier Transform Infrared spectroscopy. The qualitative analysis of the shelf stability test showed the potential of the films in fruit preservation envisioning the application in food industry for packaging. Postgraduate Program in Biomaterials and Bioprocess Engineering School of Pharmaceutical Sciences São Paulo State University (UNESP) School of Pharmaceutical Sciences São Paulo State University (UNESP) Embrapa Agroindústria Tropical/Embrapa Instrumentação Brazilian Agricultural Research Corporation (Embrapa) Postgraduate Program in Biomaterials and Bioprocess Engineering School of Pharmaceutical Sciences São Paulo State University (UNESP) School of Pharmaceutical Sciences São Paulo State University (UNESP)

Objective: This study aims to prepare and optimize indomethacin freeze-dried sublingual tablets (IND-FDST) by utilizing a quality by design (QbD) approach to achieve rapid drug dissolution and simultaneously bypassing the GIT for better patient tolerability. Methods: A screening study was utilized to determine the most significant factors which the quality attributes, namely disintegration time and % friability. Then an optimization study was conducted using a full response surface design to determine the optimized formula by varying the amount of the matrix-forming polymer (gelatin) and super disintegrant (croscarmellose sodium (CCS)). The variables' effect on the % friability, disintegration time, wetting time, and amount of drug release after 10 min (%Q10) was studied. The optimized formula was tested for compatibility, morphology as well as stability studies under accelerated conditions in addition to the in vivo pharmacodynamics in rats. QbD was adopted by utilizing a screening study to identify the significant formulation factors followed by a response surface optimization study to determine the optimized IND-FDST formulation. Results: Optimized IND-FDST comprised of gelatin/CCS combination in a ratio of 1:1 possessed adequate %friability (0.73±0.03%), disintegration time (25.40±1.21 seconds), wetting time (3.49±0.68 seconds), and % Q10 (100.99±5.29%) as well as good stability under accelerated conditions. IND-FDST also showed significant inhibition of edema, tumour necrosis factor-alpha, and interleukin-6 release in vivo compared to the oral market product by 70%, 42%, and 65%, respectively. Conclusion: QbD presents a successful approach in the optimization of a successful IND-FDST formula that showed superior in vivo and in vitro characteristics.

The disposal of the milled asphalt mixtures has a negative impact on the environment. The reuse of recycled paving materials in road pavement may improve the mechanical properties of asphalt concrete mixtures. These properties are mostly related to major pavement distresses. Therefore, the aim of this research is to investigate the possibility of reusing the recycled paving materials in cold asphalt concrete mixtures. Also, it aims to determine the critical response parameters such as vertical stress on the top of base layer and tensile strain at the bottom of asphalt layer in a flexible pavement. The cold asphalt mixtures were prepared with different percentages of recycled aggregates. They were 0%, 25%, 50%, 75% and 100%. The laboratory testing program for asphalt mixtures included standard Marshall test, loss of stability test, wheel tracking test and triaxial shear test. BISAR software was used to determine the stress and strain values. The results indicated that the recycled aggregate can be used to reduce the asphalt content of paving mixtures. Moreover, the mixtures with recycled aggregate of 75% and 100% achieved the better performance of the cold asphalt concrete mixtures.

Introduction. Currently, for the treatment of gastric ulcer, drugs with a combined effect are used. To eliminate possible side effects of the drugs used, the search for new molecules to create more effective and safe histamine H2 receptors continues. As a possible solution to these problems, we investigated the substance dinitrate of 2-phenyl-9-diethylaminoethylimidazo[1,2-α]benzimidazole (DFDB).Aim. The aim of this study was to obtain 2-phenyl-9-diethylaminoethylimidazo[1,2-α]benzimidazole dinitrate tablets and develop methods for quality control.Materials and methods. The object of study was tablets based on the substance DF DB. The physicochemical and technological properties of the tablet dosage form were studied. Pharmaco-technological and physico-chemical indicators were determined according to the methods of the State Pharmacopoeia of the XIV edition. Identification and quantitative determination of DFDB in tablets was performed by HPLC.Results and discussion. Based on the physico-chemical properties and determination of the main technological indicators of DFDB, an optimal tableting technology has been developed. The optimal composition of tablets has been developed. Identification of tablets is proposed to be carried out using HPLC in comparison with the standard sample of DFDB. Related impurities, according to the data obtained, do not exceed 0.1 %. We found that the tablets do not have an antimicrobial effect. The analyzed tablets correspond to category 3A. The content of DFDB should be from 95 to 105 % of the declared amount in one tablet. During the analysis, we conducted biopharmaceutical and technological studies of the finished dosage form during storage under the conditions of long-term stability testing in polymer cans with screw-on lids. It is shown that the selected composition of excipients and the production technology ensure the stability of the finished dosage form for two years of storage under the observed conditions. To select the tableting technology, the main technological properties of the DFDB substance are analyzed. The choice of excipients and the composition of the film coating was carried out.Conclusion. The technology is developed and standardization of tablets based on the substance DFDB is proposed.

When drilling deep wells and ultra-deep wells, the downhole high temperature and high pressure environment will affect the emulsion stability of oil-based drilling fluids. Moreover, neither the demulsification voltage method nor the centrifugal method currently used to evaluate the stability of oil-based drilling fluids can reflect the emulsification stability of drilling fluids under high temperature and high pressure on site. Therefore, a high-temperature and high-pressure oil-based drilling fluid emulsion stability evaluation instrument is studied, which is mainly composed of a high-temperature autoclave body, a test electrode, a temperature control system, a pressure control system, and a test system. The stability test results of the instrument show that the instrument can achieve stable testing and the test data has high reliability. This instrument is used to analyze the factors affecting the emulsion stability of oil-based drilling fluids. The experimental results show that under the same conditions, the higher the stirring speed, the better the emulsion stability of the drilling fluid; the longer the stirring time, the better the emulsion stability of the drilling fluid; the greater the oil-water ratio, the better the emulsion stability of the drilling fluid. And the test results of the emulsification stability of oil-based drilling fluids at high temperature and high pressure show that under the same pressure, as the temperature rises, the emulsion stability of oil-based drilling fluids is significantly reduced; at the same temperature, the With the increase in pressure, the emulsion stability of oil-based drilling fluids is in a downward trend, but the decline is not large. Relatively speaking, the influence of temperature on the emulsion stability of oil-based drilling fluids is greater than that of pressure.

Two dimensional (2D) perovskite materials, are more stable than 3D perovskite materials, which could solve the stability issue of perovskite solar cells (PSCs). However, the photovoltaic conversion efficiency (PCE) of PSCs based on 2D perovskite materials was low, due to the high dielectric and quantum confinement of 2D perovskite. In this work, we propose a solvent-assisted method to prepare 2D perovskite films, where the solvent was distributed in a gradient. Therefore, the top-down crystallization process of 2D perovskite can be accurately controlled. The PCE of PSCs fabricated by the solvent-assisted method was enhanced by 48%, compared with the control device. For the packaged devices, the stability test demonstrated that 94% of the initial PCE was still maintained after 1500 hours of storage (25 °C, RH 40%). After carefully analyzing the photophysical process of the carriers in the PSCs based on 2D perovskite, the enhanced carrier transfer mechanism of the solvent-assisted method has been proposed.

In this study, the synthesis of magnetite was carried out through the reversed coprecipitation method with ammonium hydroxide (NH4OH) as precipitating agent. The aim of the study was to obtain the most appropriate moles ratio of Fe(III) and Fe(II) in obtaining the best characteristics of magnetite, considering that Fe (II) was easily oxidized to Fe (III). Characterization of synthesized magnetite was performed using a Fourier Transform Infrared (FTIR) spectrophotometer and X-Ray Diffraction (XRD). The results showed that the moles ratio of Fe (III) and Fe (II) that produced magnetite with high yield, FTIR spectra absorption and diffractogram peaks with high intensity was magnetite synthesized using a ratio of Fe (III) and Fe (II) = 1.5: 1. Yield of magnetite synthesized in this condition was 81%. Based on the stability test, magnetite was stable at pH 2-10.

As a means of gaining a better understanding of the impact of compaction energy levels on the thickness of flexible pavements, this study investigated samples that were 50% thicker than the standard Marshall specimen sizes. The gradations for those longer (thicker) specimens were based on the binder course gradations as specified by the Republic of Turkey’s General Directorate of Highways. To obtain reliable assessments of the thicker specimens, we compared our test results with those of a control group consisting of standard Marshall Briquettes prepared using the same materials. All specimens were compacted with 10 different compaction energy levels that were increased by fives, starting from 50 blows and ending at 95 blows. After determining their lengths, volumes and specific gravities, a special marble cutter was used to split the thick specimens into two equal parts. Those two identical specimens were identified as the "thin specimens". Subsequently, the Marshall stability test and the indirect tensile test were applied both to the standard Marshall specimen group and the thick and the thin specimen groups. The test results showed that asphalt specimens of 47 and 95 mm in height were optimally compacted after being subjected to 65 and 70 blows.

The demands for high-purity hydrogen required in fuel-cell applications impose new goals and challenges for design of well performing water-gas shift (WGS) catalysts. Gold-based catalysts have exhibited high activity in the WGS reaction at low temperature. Preparation of appropriate and economically viable supports with complex composition by various synthesis procedures is an attractive approach to WGS performance improvement. The effect of two different preparation methods (wet impregnation or mechanical mixing) and ceria content (10, 20 or 30 wt%) on textural, structural, surface and reductive properties and WGS activity of gold catalysts was studied. Additionally, the role of Y2O3 as a promoter of ceria was examined. Long-term stability test was carried out at 260 °C over the most active catalyst. The composition of the best performing sample (composed of about 70 wt% alumina), prepared by mechanical mixing, was considered promising in case of practical applications because of its cost efficiency. The combination of gold nanoparticles and alumina supported Y-doped ceria proved an advantageous approach for developing new catalytic formulations with high effectiveness in clean hydrogen production.

Three-dimensional (3D) printing has become a promising manufacturing technique for pharmaceutical products. Fused deposition modeling (FDM) is the most affordable printing technology. But this technique has two major drawbacks: limited drug-loading capacity and the stability of thermolabile drugs. So, other techniques such as melt casting could be associated with FDM to overcome these limitations. In the melt casting method, the drug is mixed with a molten polymer and is poured in the mold and allowed to solidify. The present study for the first time describes the preparation of a multi-compartment polypill permits the physical separation of incompatible drugs by combination of FDM and melt casting techniques. A two-compartment polypill was made using FDM by Eudragit® L100-55 and simultaneously its compartments were filled by aspirin and simvastatin containing molten PEG 6000. Simultaneous usage of FDM and melt casting techniques could increase the drug-loading capacity of 3D-printed polypills. The low temperatures used in melt casting and the absence of solvent in this method would warrant the integrity of polypills, the complete separation of incompatible drugs, and their stability. The prepared polypills showed good uniformity in drug content which confirms the precision of FDM and melt casting techniques. Drug interaction was investigated before and after the accelerated stability test using DSC, which showed that 3D-printed polypills successfully preserved drugs from the interaction. For the first time, this study demonstrates the feasibility of the combination of FDM and melt casting techniques as an innovative platform for CVD polypills production.

Recently cold spray coating technology was used for many applications in petrochemical business especially for high temperature required section. For this reason, the applied coating must be able to withstand at least 800 °C. The developed Ni/Cr cold spray coating was studied mainly on high temperature resistant property. Ni/Cr with the ratio of 80/20 feedstock powders revealed the highest deposition efficiency and it was selected to use as optimum feedstock powder compositions for the less of experimental study. Finally, it was found that Ni/Cr cold spray coatings reveal excellent thermal stability performance after completed both corrosion and thermal shock tests.

In this paper, we study the effect of the spectral composition of light and temperature on the change in colorimetric characteristics during accelerated tests of the light resistance of a composite based on glass-filled polyphenylene sulfide. The activation energy of photodestruction is determined. The revealed patterns indicate the promising use of colorimetry as a nondestructive method of stability testing of polyphenylene sulfide-based materials.

This paper evaluated the effects of sasobit polymer (Sasobit®) on the characteristics of asphaltic concrete with a view to investigating its suitability as an additive in asphaltic concrete. Sasobit®, bitumen and aggregates were procured from a Construction Company site office, along Shagamu-Ibadan expressway. Sasobit® modified bitumen was prepared by adding Sasobit® to bitumen with increasing weight of Sasobit® at 1.0, 1.5, 2.0, 2.5 and 3 % by the weight of the bitumen. Penetration and softening point tests were carried out on the samples and the mix-ratio for the bitumen – polymer mixture was determined. Asphaltic concrete samples with and without Sasobit® were prepared. The samples were subjected to Marshall Stability test. The stability, flow, specific density, voids filled with bitumen (VFB), air voids (VA) and voids in the mineral aggregate (VMA) weredetermined. The values of stability, flow, specific density, voids filled with bitumen, air voids and voids filled in the mineral aggregates for sample without Sasobit® were 13.63 kN 2.91 mm, 2.51, 64.64 %, 4.29 % and 18.19 %, respectively, while for those with Sasobit® at mix – ratio of 1.7 % bitumen – polymer mixture, the values were 14.67 kN, 2.41 mm, 2.55, 73.30 %, 3.96 % and 16.39 % respectively. The result showed that, Sasobit® as additive in asphaltic concrete improved its properties. Keywords: Sasobit®, Asphaltic Concrete, Stability, Flow, Voids filled with bitumen, Air voids, Voids in mineral aggregate

Li-air batteries are limited to lab-scale research owing to the uninterrupted formation of discharge products. In the case of Li-CO2 batteries, the increase in overpotential caused by Li2 CO3 formation results in cell death. In this study, Cu2 O crystals having three different types of shapes (i.e., cubic, octahedral, and rhombic) were synthesized to compare their catalytic activity toward CO2 reactions. The full-cycle and long-term stability test revealed that rhombohedral Cu2 O facilitates Li2 CO3 decomposition more efficiently than that of cubic and octahedral Cu2 O. The cycle was extended to investigate the photocatalytic activity of the rhombic Cu2 O by illuminating the cell. The repeated cycles to 1 h showed a maximum overpotential of 1.5 V, which is 0.5 V lower than that of the cell without illumination. A postmortem analysis of the cell after dividing the cycles into segments demonstrated interesting results concerning the role of light and Cu2 O during the cell cycle.

Objective: The main objective of this work was to evaluate the performance of recently developed dynamic-mechanical thermoanalysis (DMTA) test as a rapid rheological alternative to conventi...

Transcatheter aortic valve replacement (TAVR) has emerged as an effective therapy for the unmet clinical need of inoperable patients with severe aortic stenosis (AS). Current clinically used tissue TAVR valves suffer from limited durability that hampers TAVR's rapid expansion to younger, lower risk patients. Polymeric TAVR valves optimized for hemodynamic performance, hemocompatibility, extended durability, and resistance to calcific degeneration offer a viable solution to this challenge. We present extensive in vitro durability and stability testing of a novel polymeric TAVR valve (PolyNova valve) using 1) accelerated wear testing (AWT, ISO 5840); 2) calcification susceptibility (in the AWT)-compared with clinically used tissue valves; and 3) extended crimping stability (valves crimped to 16 Fr for 8 days). Hydrodynamic testing was performed every 50M cycles. The valves were also evaluated visually for structural integrity and by scanning electron microscopy for evaluation of surface damage in the micro-scale. Calcium and phosphorus deposition was evaluated using micro-computed tomography (μCT) and inductive coupled plasma spectroscopy. The valves passed 400M cycles in the AWT without failure. The effective orifice area kept stable at 1.8 cm with a desired gradual decrease in transvalvular pressure gradient and regurgitation (10.4 mm Hg and 6.9%, respectively). Calcium and phosphorus deposition was significantly lower in the polymeric valve: down by a factor of 85 and 16, respectively-as compared to a tissue valve. Following the extended crimping testing, no tears nor surface damage were evident. The results of this study demonstrate the potential of a polymeric TAVR valve to be a viable alternative to tissue-based TAVR valves.

Bitumen is the most popular binding material in road construction. Nowadays due to rapid infrastructure growth and increasing in the number of vehicles it is necessary to build the roads which can sustain adverse traffic loading and extreme weather conditions. Also, disposal of waste plastic is a big problem nowadays. Studies have found that, effective use of plastic in the bitumen to improve its original properties. Plastic added to bitumen by two ways first is dry process and another is wet process. Most of the research was done on dry process. Coming to wet process some research works carried on adding waste plastic bags to the bitumen and found satisfactory. Present study concentrating on adding the shredded waste plastic water bottles to the bitumen to improve its rheological properties. In present study plastic is heated up to its melting point, then bitumen is added to the liquid plastic and mixed thoroughly with the help of mechanical stirrer. On the prepared composite material (i.e. plastic modified bitumen – PMB) laboratory tests was conducted like softening point, ductility value, elastic recovery, penetration, specific gravity, flash and fire point. In continuation, conducting Marshall stability test on the same plastic modified bitumen samples to finalize the optimum percentage of plastic to be added. Finally, comparison made between plastic modified bitumen sample with original bitumen sample. Present study concluded that, replacing the bitumen with 5% & 7.5% of PET plastic improves the rheological properties of the bitumen. From the Marshall test, it was declared that 7.5% replacement of bitumen with plastic gives more stability than 5% replacement. From this experimental investigation declared that, 7.5% of the PET plastic is the optimum percentage which can add to the bitumen to use in flexible pavements for improving the maintenance period also for improving the rheological parameters of bitumen.

Objective To study the repair potential of seven commercial glass-ionomer cements (GICs) using an in vitro edge compression test model. Materials and methods A total of 448 normal and 192 repaired cylindrical specimens (6 × 4 mm) were produced from 6 GICs and one resin-modified GIC. Repaired samples consisted of a base aged for 1 month before repaired by an overlying layer. All samples were matured for 1 day, 1 week, 1 month or 3 months before compression, and edge tests were performed respectively on the whole surface (compressive strength, CS) or on the edge (edge stability, ES) using a universal testing machine. Results For normal specimens, Ketac Universal (KU) illustrated a significantly higher CS than other groups at all time points (p p > 0.05). Repaired KU significantly improved CS compared to repaired EQF and Fuji II (FII) after 1 day. No statistical difference was found in ES among these groups (p > 0.05). Conclusions KU provided the fastest maturation and greatest CS and ES in both normal and repair models after short-term ageing. Repair of GICs could potentially be achieved directly onto the fractured substrate and the subsequent improved mechanical performance could be maintained for at least 3 months. Clinical relevance This study provides a potential alternative in-vitro method to assess GIC restoration failure as well as provide insight into the mechanisms of GIC restoration repair.

NIM has developed LED filament standard lamps for total luminous flux with excellent long-term stability, uniform distribution of luminous intensity, and the E27 Edison screw base which is compatible with present incandescent standard lamps. The standard lamp consists of six high-power LED filaments which are sealed in a G150 glass bulb and filled with He gas. All the 12 lamps were aged for 500 hours before the 315 days’ long-term stability test. 9 lamps are lighted for 1 hour every day. One lamp is continuously operated for about 6000 hours, and 2 lamps are well stored on a shelf. The results show that the long-term stabilities of the 3 cases are better than 0.07%. This LED filament lamp could be promising as a transfer standard of total luminous flux.

Fire resistance testing of components made of carbon fibre reinforced polymers (CFRP) usually demands intermediate-scale or full-scale testing. A bench-scale test is presented as a practicable and efficient method to assess how different fire protective systems improve the structural integrity of CFRPs during fire. The direct flame of a fully developed fire was applied to one side of the CFRP specimen, which was simultaneously loaded with compressive force. Three different approaches (film, non-woven, and coatings) were applied: paper with a thickness in the range of μm consisting of cellulose nanofibre (CNF)/clay nanocomposite, nonwoven mats with thickness in the range of cm and intumescent coatings with a thickness in the range of mm. The uncoated specimen failed after just 17 s. Protection by these systems provides fire stability, as they multiply the time to failure by as much as up to 43 times. The reduced heating rates of the protected specimens demonstrate the reduced heat penetration, indicating the coatings’ excellent heat shielding properties. Bench-scale fire stability testing is shown to be suitable tool to identify, compare and assess different approaches to fire protection.

Purpose: The goal of this study is to develop discriminatory dissolution method to be used as a release parameter for testing and evaluating product performance by using quality by design trials intended for regulated markets. Dissolution testing is a requirement for all solid oral dosage forms and is used throughout the development life-cycle for product release and stability testing. Methods: After testing solubility in the dissolution medium, surfactant concentration, rotation speed, dissolution medium pH, and apparatus type, the appropriate conditions were established. Results: According to investigations, the optimal dissolution conditions were obtained utilising a USP apparatus II, 900 ml of 0.4 percent SLS medium in pH 4.5 acetate buffer, and a 75 rpm rotation speed. Conclusion: This research shows how a discriminate dissolution method for Rivaroxaban, a BCS Class 2 medication with pH-independent solubility, was developed in a systematic manner. The dissolution method described here can be utilised as a quality control test for Rivaroxaban tablets, with a particular focus on batch to batch evaluations.

The residual moisture (RM) level strongly impacts the stability of freeze-dried biopharmaceuticals. On the one hand, the RM should not be too high to keep the reaction potential of water molecules low and to avoid a decrease in the glass transition temperature through the plasticizing effect of water. On the other hand, overdrying has been described to negatively impact protein stability. Consequently, an optimal RM has to be established and justified for approval by authorities. Therefore, end products with different RM are analyzed over storage. The different RM levels are typically obtained by slightly varying the lyophilization process itself; but deviations from the original process are critical. Additionally, samples can be taken during lyophilization runs, e.g. at the end of primary drying or after the ramp into secondary drying. This, however, does not allow for good control over the RM. Here we present the adaption of a headspace water spiking technique using a microliter syringe to precisely increase and adjust the RM. This technique is suitable to reproducibly introduce water in the microliter scale to achieve RM of less than 1% [w/w] with high precision depending on the dry cake weight. In addition, we show that by using different fill volumes and cake densities, an equal three-dimensional water distribution throughout the whole cake can be achieved. Furthermore, potential limitations and risks in manual RM introduction are discussed.

By the stability test on the composite curved plates of different radius and different size, studying the influence of different radius and different size on the buckling loads and the buckling modes of the test pieces. The following results are obtained: the radius of the test pieces reducing 25%, the buckling load increases 26%; while the influence of radius on the buckling mode is very small. The height of the test pieces reducing 42.3%, the buckling load increases 28%; the arc length of the test pieces reducing 20.8%, the buckling load reduces 13.4%; while the influence of size on the buckling mode is great.

Quetiapine fumarate (QF) is an atypical antipsychotic used off-label for the treatment of delirium in critically-ill infants and children. For the treatment of pediatric populations or patient populations with trouble swallowing tablets, an oral suspension would be an ideal dosage formulation. However, there are no liquid formulations of QF commercially available. Therefore, a compounded oral suspension prepared from the commercial QF tablets is widely used in clinical settings. The extemporaneous preparation of QF compounded oral suspension changes the formulation from a solid form to a liquid form. Thus, the stability of QF compounded oral suspension should be critically evaluated to guide pharmacists for administration and storage of QF compounded oral suspensions. However, the stability of the nonaqueous oral QF suspension was not measured. The objective of this study was to develop QF compounded oral suspensions at 10 mg/mL by using commercial QF tablets in two readily available aqueous vehicles (Ora-Sweet and Ora-Blend) and measure their stability at both room temperature and under refrigeration. Physical stability of the QF compounded suspensions were evaluated by appearance and odor. Chemical stability of the QF compounded suspensions were evaluated based on pH, degradation, drug content and the amount of the drug dissolved in the vehicles. An HPLC method was validated and used to evaluate QF compounded suspensions over 60 days. In addition to the total drug in the suspensions, the dissolved drug in the vehicles was also measured during the stability testing and evaluated as a stability parameter. Overall, QF suspension prepared in Ora-Blend was preferable, demonstrating a superior 60-day stability at both room temperature and refrigerated storage.

The paper aims to create models of stabilizer depletion in smokeless powders as a background for optimisation of smokeless propellants stability testing in the Czech Armed Forces. It presents results of first half of an ageing study of different propellants in stock stabilized with DPA, AKA-II and EC at temperature range from $40^{\circ}\mathrm{C}$ to $70^{\circ}\mathrm{C}$. Thus resulting kinetic parameters should correspond with kinetic parameters valid in storage temperature range from $10^{\circ}\mathrm{C}$ to $30^{\circ}\mathrm{C}$ enabling to make reliable models of stabilizer depletion during storage. AKA-II shows very low order of reaction and high activation energy leading to considerably long shelf life but harsh stabilizer depletion when the end of shelf life is nearing. Propellants stabilized by DPA shows common values of kinetic parameters and pretty predictable primary stabilizer depletion. EC shows very low reactivity and thus very long shelf life. On the other hand its stabilizing ability is unsure and so other stability test might be needed to confirm safety.

Objective: This study aimed to evaluate the dimensional stability and maintenance of details of conventional and high stability alginates up to 5-day storage. Methods: Two types of alginates were selected (n=10) for this study, conventional (Hydrogum) and high stability alginates (Hydrogum 5), which were produced with the aid of a cylindrical metal block and a ring-shaped metal mold (Specifications 18, 19, and 25, ANSI/ADA). Ten images were obtained from the molds for the dimensional stability test, which were taken immediately after their production and at each different storage periods (15 min, 24 h, 48 h, 72 h, 96 h, and 120 h) by a digital camera. The specimens were kept hermetically sealed in plastic bags (23°C) and then used to obtain 140 (n=70) dental stone models, used in the detail reproduction test, in which the angular accuracy of three grooves (20 µm, 50 µm, and 75 µm) was observed at each period. The details reproduction accuracy was classified using a predetermined score classification. Measurements of dimensional changes were made in the Corel DRAW X6 program. The data were submitted to the Student’s t-test (α?#8197;= 0.05). Results: A statistically significant difference concerning the size of the matrix was observed after 24h for both alginates, and a statistically significant negative linear dimensional change (contraction) was verified after 24 h of storage (1.52% for the high stability alginate, and 1.32% for the conventional alginate). The high stability alginate kept the full details for 72 hours, while the conventional alginate, for 24 h. Both alginates reproduced the 75 µm groove at all storage periods. Conclusion: Impressions made with both alginates presented satisfactory clinical results when the alginates were immediately poured. RESUMO Objetivo: O presente estudo teve como objetivo avaliar a estabilidade dimensional e manutenção de detalhes de alginatos convencionais e de alta estabilidade por até 5 dias de armazenamento. Métodos: Para esse estudo, foram selecionados dois tipos de alginatos: convencional (Hydrogum) (n = 10) e de alta estabilidade (Hydrogum 5) (n = 10), sendo produzidos com o auxílio de um bloco metálico cilíndrico e um molde metálico em forma de anel (especificações 18, 19 e 25, ANSI/ADA). Para o teste de estabilidade dimensional, dez imagens foram obtidas imediatamente e para cada tempo de armazenamento (15 min, 24, 48, 72, 96 e 120 horas), realizadas por câmera digital. As amostras foram mantidas hermeticamente fechadas em sacos plásticos (23°C). Para o teste de reprodução de detalhes, as amostras foram utilizadas para obter 140 (n = 70 por grupo) modelos de gesso, sendo observada a precisão angular de três sulcos (20 µm, 50 µm e 75 µm) para cada período. A precisão da reprodução de detalhes foi classificada usando uma classificação de pontuação predeterminada. As medições das mudanças dimensionais foram feitas no programa Corel DRAW X6. Os dados foram submetidos ao teste t de Student (α = 0,05). Resultados: Foi observada diferença estatística em relação à matriz após 24h para ambos os alginatos. Uma mudança dimensional linear negativa estatisticamente significativa (contração) foi verificada após 24 h de armazenamento (1,52% para alginato de alta estabilidade; 1,32% para alginato convencional). O alginato de alta estabilidade manteve os detalhes completos por até 72 horas, enquanto o alginato convencional, por 24 horas. Os alginatos reproduziram o sulco de 75 µm para todos os períodos. Conclusão: As impressões feitas com ambos os alginatos devem ser imediatamente vazadas para se ter resultados clínicos satisfatórios.

A certified reference material (CRM) for reserpine was investigated by raw material purification, qualitative analysis, quantitative analysis, homogeneity testing, stability testing, characterization, and uncertainty evaluation. The candidate reference material was prepared by recrystallization of purchased reserpine. After purification and drying, the candidate materials were enclosed in brown glass bottles. The chemical composition of the candidate reserpine reference material was confirmed by infrared spectroscopy, high-resolution mass spectrometry, and nuclear magnetic resonance. The homogeneity and stability of several sample bottles of the candidates were studied by stratified random sampling. With the cooperation of eight qualified laboratories, the purity of reserpine was analyzed by a mass balance method (including area normalization, water content, ash content and residual solvent analyses by liquid chromatography) with a certified purity mass fraction of 99.3 % and an expanded uncertainty of 0.5 % (k = 2). This reference material has been identified as a Chinese national-grade secondary CRM, which is numbered GBW(E) 090901, and is expected to be used in the calibration of instruments such as those used for liquid chromatography or method evaluations in food, medicine, environmental, and cosmetic analyses.

The combination of 3% sodium hyaluronate (HA) and 4% sodium chondroitin sulfate (CS) is used as a dispersive ophthalmic viscosurgical device (OVD) during cataract surgery. For most OVDs containing HA, storage at 2–8 °C is recommended to preserve product characteristics. In order to develop a dispersive OVD that can be stored at room temperature, in this study, we searched additives which can stably maintain the viscosity, a key parameter of OVD, under preservation stability testing at 60 °C. The addition of D-sorbitol to a combination OVD, 3% HA and 4% CS, suppressed the reduction in viscosity compared with other OVDs with or without additives. The addition of D-sorbitol was also effective in improving the residual viscosity of the combination OVD after thermal treatment and light irradiation. Moreover, the OVD containing D-sorbitol can be stored at 25 °C with stably maintaining the initial viscosity for at least 24 months. In conclusion, the new dispersive OVD, 3% HA, 4% CS, and 0.5% D-sorbitol, can be stored at room temperature instead of under cold conditions and may represent an attractive option for clinical use because it is not necessary to bring the product to room temperature prior to use.

In this study, Marshall test results of hot mixasphalt samples having various Hydrated Lime (HL) content rates were modelledusing Fuzzy Logic (FL) and Artificial Neural Networks (ANN). Test sets havingvarious HL content were prepared in order to investigate the effect of HL. MarshallStability test was performed on the samples to obtain the optimal AsphaltContent (AC) ratio. The results were evaluated in order to determine HLadditives’ sensitivity on the mixture parameters. The Marshall Test resultswere used to develop the FL and ANN models. The models developed producedacceptable estimations of the mixture parameters., In this study, Marshall test results of hot mix asphalt samples having various Hydrated Lime (HL) content rates were modelled using Fuzzy Logic (FL) and Artificial Neural Networks (ANN). Test sets having various HL content were prepared in order to investigate the effect of HL. Marshall Stability test was performed on the samples to obtain the optimal Asphalt Content (AC) ratio. The results were evaluated in order to determine HL additives’ sensitivity on the mixture parameters. The Marshall Test results were used to develop the FL and ANN models. The models developed produced acceptable estimations of the mixture parameters.

An alumina supported coconut chaff (ASCC) was prepared by the impregnation method, characterized, and used as a catalyst for biodiesel production from waste frying oil (WFO). The effects of factors affecting the biodiesel production process, reaction temperature, reaction time, catalyst loading, and methanol/WFO molar ratio at a fixed stirring speed of 250 rpm, were investigated. The result obtained revealed that at 65 °C reaction temperature, 2.5 h reaction time, 1.5 wt% catalyst loading and 12:1 methanol/WFO molar ratio, the biodiesel yield was 91.05 wt%. The stability test showed that the ASCC catalyst could be reused up to five times. Keywords: Biodiesel, Coconut chaff, Catalyst, Transesterification, Waste frying oil

Water electrolysis was recognized as an effective method for new energy sources. In this work, an effective FexNiyOOH/ESS with high surface area and good catalytic activity was prepared for water electrolysis. Its morphologies at different ratio of Fe/Ni atoms were diverse, such as flower ball, flake, and block, etc. Test results showed that at 10 mA cm−2 and 300 mA cm−2, the hydrogen evolution overpotentials of Fe1.5Ni0.5OOH/ESS were 172 mV and 258 mV. The oxygen evolution overpotentials of Fe0.2Ni1.8OOH/ESS were 208 mV and 308 mV at 10 mA cm−2 and 600 mA cm−2. During the 136-h stability test, the oxygen evolution activity of Fe0.2Ni1.8OOH/ESS was basically unchanged. The Fe1.5Ni0.5OOH//Fe0.2Ni1.8OOH in alkaline conditions presented good performance for water electrolysis. Water electrolysis experiment was carried out at 1.58 V, and the current density reached to 10 mA cm−2. FexNiyOOH/ESS exhibited higher electrocatalytic activity and superior stability at high current density.

The Ni-rich LiNi0.8Co0.1Mn0.1O2 layered oxide (NCM811) is attracting considerable attention as a high-capacity cathode material for rechargeable Li-ion batteries. However, due to its inherent structural/chemical/electrochemical instability, NCM811 with high Ni content suffers from significant performance degradation upon storage even in ambient atmospheres as well as during charge–discharge cycling. Herein, we demonstrate a simple but effective surface-tuning approach to mitigate storage-induced degradation of NCM811, which is based on the conversion of undesirable Li residues to a protective Li3PO4 nanolayer via phosphate treatment. The accelerated storage stability test shows that phosphate-modified NCM811 exhibits remarkably improved electrochemical performance (capacity, cycle life, and rate capability) over the pristine one after being stored under harsh environmental conditions. A combined analytical study indicates that surface tuning through phosphate treatment enhances the storage stability of NCM811 by eliminating impurity-forming Li residues and producing a Li3PO4 nanolayer that inhibits parasitic reactions at the electrode–electrolyte interface. Furthermore, Li3PO4 provides an effective barrier to H2O and CO2 infiltration into the particle agglomerates, thereby suppressing the loss of particle integrity.

PURPOSE: To evaluate the effect of ZrO2 nanoparticles incorporation (in two different ratios 1% and 3%) on some properties of one high-impact heat cured PMMA resin material when it was processed by two different methods (Conventional and Microwave curing methods).Materials & Methods: One high-impact heat cured PMMA resin (Trevalon Hi) was used in this study to be modified with nano-ZrO2 in two different ratios (1% and 3%). Both unmodified and modified high-impact heat cured PMMA resin were subjected to three different tests (Flexural strength test, Microhardness test, and Color stability test). A total of ninety specimens were prepared, thirty specimens for each test (N=30). Within each test specimens, there were three groups (n=10), (HI) group: was prepared from high-impact heat cured PMMA resin without modification by nano-ZrO2 (as a control group). (1%n-ZrO2 HI) group: was prepared from high-impact heat cured PMMA resin modified by 1% nano- ZrO2. (3%n-ZrO2 HI) group: was prepared from high-impact heat cured PMMA resin modified by 3% nano- ZrO2.Within each group, five specimens were prepared by conventional water-bath curing method, while the other five specimens were prepared by microwave curing. The significance level was set at P ≤ 0.05. Statistical analysis was performed with IBM® SPSS® Statistics Version 20 for Windows.Results: Modification of high-impact heat cured PMMA resin with (1% and 3%) nano-ZrO2 resulted in significant increasing in the mean values of flexural strength and VHN of all tested groups (p

This research evaluates the effect of filler type and content on rutting resistance of asphaltic materials by using laboratory experiments. To examine the effect of filler type, two traditional fillers (Silica sandstone powder and Portland cement) and a new recycled lime powder (Eggshell) were considered. To investigate the effect of filler content, three different filler contents were used. Marshall Stability test was performed on full mixes in order to determine the optimum binder content of the mixtures. Then, the static creep test was performed on Fine Aggregate Matrix (FAM) samples. The permanent strain after 10 minutes of recovery (PS-660) was considered as the indicator of potential to rutting. It was shown that PS-660 has a good correlation with total strain after 60 seconds of loading (TS-60), permanent strain after 60 seconds of recovery (PS-120), the slope of the primary (θ1) and secondary (θ2) Phases of the creep curve, binder percent of FAM samples (B%), as well as with Marshall Quotient (MQ) value of full mixes. The test results clearly demonstrated that both filler type and content can significantly influence rutting resistance of asphaltic materials.

Background Over time, improvements have been made in dentifrices and recently bioactive components have been added. It is important to address the abrasivity of these dentifrices, which can cause wear of dental restorative materials. Objectives A comparative study was conducted to examine the effects of commercial and experimental dentifrices upon commonly used dental restorative materials. Material and methods Three types of experimental dentifrices were prepared with variable concentrations of fluoride-based bioactive glass, nano-zinc oxide (ZnO) and titanium dioxide (TiO2) powder as active ingredients. A custom-made toothbrush simulator was used with variable cycles (0; 5,000; and 10,000) to treat samples prepared from dental restorative materials. Prior to and after the treatment cycles, the physical properties of the restorative materials were assessed and compared with commercial toothpaste through micro-hardness, surface roughness and color stability testing. Results The restorative materials showed an insignificant difference in terms of micro-hardness before and after the treatment with all dentifrices. A significant difference was observed in terms of surface roughness. With respect to color stability, there has been observed an insignificant difference between the control and the other 3 experimental dentifrices for all the cycles - pre, post-5,000 and post-10,000. Conclusions Experimental fluoride-containing bioactive dentifrices caused a change in the restorative material properties; however, it was minimal and the properties still met the requirements for clinical applications.

Effect of activated carbon and lithium chloride on polyimide-based fiber Bragg grating relative humidity sensor has been experimentally investigated. Through dip coating process, organic-inorganic hybrid coatings were deposited on fiber Bragg grating to form different relative humidity sensors. Experimental results show that the addition of activated carbon or lithium chloride alone could increase the humidity sensitivity (1.67 times and 1.61 times, respectively), but the structure which contains both lithium chloride and activated carbon increases the sensitivity most (3.9 times). In the 14-day stability test, the fluctuation of pure polyimide sensor is ±6.5%, while the ones of activated carbon sensor, lithium chloride sensor, activated carbon, and lithium chloride sensor are ±3%, ±8%, and ±1.6%.

Pt nanoclusters (NCs) with diameters of 1–3 nm are regarded as one of the most promising high performance oxygen reduction reaction (ORR) catalysts. However, the application of such small Pt NCs is always limited by the preparation methods and the stability of Pt. In this work, an efficient and stable ORR catalyst was prepared by assembling unprotected Pt NCs (∼1.4 nm) on ordered mesoporous carbon (OMC) via a facile strategy. The as-prepared Pt NCs/OMC (Pt loading: 10 wt %) exhibited more desirable ORR catalytic performance. The specific activity (SA) and mass activity (MA) of Pt NCs/OMC at 0.9 V were 2.73 and 3.81 times higher than those of the commercial Pt/C (Pt loading: 20 wt %) in 0.1 M HClO4. Meanwhile, the Pt NCs/OMC exhibited more satisfactory stability. The Pt NCs/OMC displayed relatively slight losses of 2.3% in MA and 2.7% in SA after the 1500 cycles accelerated stability test, in contrast to respective losses of 35.8% and 37.2% for the commercial Pt/C. In consideration of the enhanced catalytic performance and excellent stability, the as-prepared Pt NCs/OMC demonstrates great potential as a practical ORR catalyst.

This study investigated the high-temperature stability of CSZ, YSZ, and MSZ specimens in a CaCl2-CaF2-CaO molten salt at 1200 °C for the application of the materials as oxygen-ion-conducting solid-oxide membrane anodes in the electroreduction process of metal oxides. YSZ exhibited the lowest degradation among the tested specimens in a high-temperature stability test, whereas CSZ showed the highest degradation. The weight loss was not severe with concentrations of CaO up to 10 wt%. CSZ showed peaks for m-ZrO2, YSZ showed peaks for t-ZrO2 and CaZrO3, and MSZ showed peaks for t-ZrO2 and m-ZrO2 in 0 wt% CaO. In the case of 5 wt% CaO, all specimens exhibited m-ZrO2 and CaZrO3 peaks, In the cases of 10 wt% and 20 wt% CaO, CSZ and MSZ showed peaks for CaZrO3, and YSZ showed peaks for m-ZrO2 and CaZrO3. While CSZ and MSZ became significantly looser as the CaO concentration was increased to 10 wt%, YSZ became significantly denser due to the formation of a protective layer and attack dependent on the solubility of CaO in the molten CaCl2. In terms of long-term operation, YSZ was demonstrated to possess superior high-temperature stability compared to CSZ and MSZ, and CaO concentrations from 5 wt% to 10 wt% were found to be significantly more stable than other concentrations.

Cell sorting requires a stable flowing speed, especially for a fast flow cytometry like the optical time-stretch imaging. The flowing speed fluctuation of Euglena cells and Nile red particles is tested and evaluated by a home-built flowing speed testing system. Higher flowing speeds have better stability. Flowing microchannels with controlling steps also improve the speed stability. The time fluctuation is ~ 1 ms under a flowing speed of ~ 1.4 m/s. Cell sorting can be realized by either using an ultra-short delay time between the sorting point and imaging point, which is suitable for relative lower cells counting speed (~ 5000 cells/s), or developing effective fluctuation controlling methods for higher counting speed, like using step glass microchannels.

In this study, bitumen was modified with different percentages of SBS polymer and Zycotherm additive. Effect of SBS modification and Zycotherm additive in the bituminous concrete mixture was evaluated by Marshall Stability test and Indirect tensile strength test. Comparisons were made between different bituminous mixtures prepared by base bitumen, SBS modified bitumen and Zycotherm modified bitumen. SBS dosage in bitumen was kept 3, 5 and 7%. The Zycotherm additive dosage was kept same for all mixes i.e. 0.1%. Two types of aggregate i.e. limestone and riverbed were used for this study. Marshall Stability for 5% SBS modification has shown better results. Indirect tensile strength for the mixture containing 5% SBS has shown maximum tensile strength as compared to other mixes. Limestone aggregate has shown maximum stability and maximum tensile strength as compared to riverbed aggregate. Zycotherm additive has shown no effect on mechanical properties of bituminous concrete mixtures. It was finally concluded that best results were obtained by using 5% SBS in bitumen and limestone aggregate in bituminous concrete mixtures.

Photocorrosion is regarded as an important limitation of cupric oxide (CuO) for application in photocatalysis and photoelectrocatalysis. In this paper, we firstly explore the photocorrosion mechanism of a CuO photocathode in the photoelectrocatalysis field and reveal that self-reduction of CuO caused by photogenerated electrons is a prime factor for the photocorrosion of the CuO photocathode. Aiming to solve this issue, TiO2 is introduced on the surface of CuO to form a suitable gradient band level, which is conducive to the fast export of photo-induced electrons in the bulk of CuO. Besides, a Pt cocatalyst as an electron capture layer (ECL) is selected to load on top of the CuO/TiO2 photoelectrode, further promoting the transport of electrons, thereby improving the photocorrosion stability of the CuO photocathode. Under the synergistic effect of TiO2 and Pt, the CuO/TiO2/Pt photocathode in photoelectrochemical water splitting exhibits a photocurrent density of −0.75 mA cm−2 at −0.55 V vs. Ag/AgCl and a photocorrosion stability of 84% after the stability test for 2 h. This work not only reveals the photocorrosion mechanism of the CuO photocathode, but also offers a new method for improving the photocorrosion stability of photocathodes.

Many road networks are using hot mix asphalt (HMA) to construct pavement layers. The Marshall method is the common procedure used in the design of the HMA and used at the time of the construction of the roadway to quality control. The present work is using ceramic fiber as a reinforcement to improve the characteristics of the HMA. The Marshall properties are examined by several tests such as Marshall stability test, and the flow test. The group of samples was made by utilizing 0.50, 1.0, 1.5, and 2.0 percentages of ceramic fibers by the total weight of the mixture. The results of the experiment showed the maximum Marshall stability occurred at a value of 1% ceramic fiber; the flow value decreased with increasing of fiber content, and the maximum Marshall quotient occurred at a value of 1% ceramic fiber. Also, the air voids, void filled with asphalt, and the void in mineral aggregate increased with increasing ceramic fiber content.

Asphalt mixes encounter different distress during the life cycle of asphalt pavements, among which rutting and fatigue failure are prominent. Moreover, the addition of environmentally friendly modifiers into the asphalt binder to increase the performance of asphalt mixes has been a challenging phenomenon for researchers. Calcium lignosulfonate (CL) is a waste material that is a by-product of the wood industry. In this paper, the impact of the calcium lignosulfonate on the rutting and fatigue performance of the asphalt binder was investigated. For this purpose, the Dynamic Shear Rheometer (DSR) was utilized to run the Multiple Stress Creep Recovery (MSCR) test and evaluate G ∗ /sinδ and G ∗ ·sinδ indices for the asphalt binder containing different percentages of CL. The elastic recovery test was also conducted on the asphalt binder. In order to analyze the thermal storage stability of CL-modified asphalt binders, the storage stability test was considered. The Field Emission Scanning Electron Microscope test showed that using CL as a binder modifier makes the texture of the asphalt binder spongy and porous. The conventional test results indicated that increasing the CL amount in the asphalt binder led to an increase in the stiffness of the asphalt binder. The rheological test results showed that the rutting resistance of the asphalt binder improved by adding up to 15% of the CL powder; however, the fatigue performance and the elasticity of the asphalt binder declined by increasing the CL content in the asphalt binder. The storage stability test revealed that the dispersion of CL in the asphalt binder was uniform; moreover, the presence of CL in the asphalt binder could not adversely affect the thermal storage stability of the modified asphalt binder.

Sterile filtration is an effective method to remove any microorganisms present during nanoemulsion preparation. However, it lacks effective control parameters. Here, we established a simple and rapid approach for the process control of nanoemulsion sterile filtration by utilizing optical density detection as a process control parameter. During sterile filtration, the optical density or optical density ratio of the filtrate were continuously monitored to explore the correlation between optical density and the emulsion content and the change in the optical density ratio before and after sterile filtration. In the emulsion stability test, the optical density ratio was determined. A good correlation was obtained between the optical density and the nanoemulsion content during sterile filtration, thereby reducing sterile filtration loss. The optical density ratio changed significantly after sterile filtration, indicating that it could be used as a process control parameter to monitor leakage during emulsion sterile filtration. The optical density ratio can be a characterization index for stability monitoring as it is more sensitive than particle size detection and more convenient than large particle detection. These parameters may be used for sterile filtration process control and as an index for nanoemulsion characterization. This approach overcomes the limitations of existing nanoemulsion characterization methods.