Effect Of Stabilizers Research Articles

ZnO nanoparticles doping with transition metal elements in polymeric and biomacromolecular matrix and their optical evolution

Abstract The 5% Cu doped zinc oxide nanoparticles in polyvinylpyrrolidone matrix and 5% Fe doped zinc oxide nanoparticles in biotin matrix were prepared and the effect of dopants and stabilizers on different properties were investigated. Surfactant controlled particle sizes and dopants induced changes in optical properties were reported as evident from X-ray diffraction data analysis and absorption measurements. High resolution transmission electron microscopy results of Cu doped ZnO nanoparticles are close to the XRD results. The reduced band gaps are estimated to be 2.90 eV and 2.37 eV for Cu and Fe doped ZnO respectively from absorption measurements. Photoluminescence measurements show how the dopants and surfactant can alter the excitonic and defect related emission in the doped ZnO nanoparticles. Raman spectroscopy of Cu doped ZnO nanoparticles shows characteristics of Cu in to ZnO lattice and new phonon scattering mode. The room temperature ferromagnetism in Fe doped ZnO and its correlation with defects were discussed.

Effect of chain extender and light stabilizer on the weathering resistance of PBAT/PLA blend films prepared by extrusion blowing

Biodegradable poly (butylene adipate‑co‑terephthalate)/polylactic acid (PBAT/PLA) films were prepared by melt blending and blowing technology under the presence of a chain extender and two different light stabilizers. A comparison of the infrared spectra of the film with and without these additives before and after the weathering tests showed that the addition of chain extender and light stabilizer improved the polymer weathering resistance significantly. Without PLA, PBAT underwent serious chain scissions and crosslinking during the weathering. PBAT/PLA film chain scissions were weakened as the PLA content increased. After 200 h of the weathering, the machine direction (MD) tensile strength as well as MD and transverse direction (TD) elongation at break of both PBAT and PBAT/PLA films decreased, while their TD tensile strength changed only slightly. The film with the 85:15 PBAT:PLA ratio containing 1.5 phr of chain extender showed much better flexibility without any changes to its tensile strength. The addition of 0.6 phr of light stabilizer (Chimassorb2020 or Irganox 1010) to this blend showed significantly improved weathering resistance. Better weathering improvement was observed when Chimassorb2020 was added. The tensile strength of PBAT/PLA/ADR/ Chimassorb2020 sample in the machine and transverse directions decreased by 8.4 and 28%, respectively, after 200 h of weathering.

Effects of Different Stabilizers on Miniemulsion Methyl Methacrylate Polymerizations

AbstractThe present work evaluated the effects of different ionic and nonionic stabilizers and respective concentrations on methyl methacrylate (MMA) miniemulsion polymerizations. The stabilities of the prepared miniemulsions are characterized through sedimentation and phase separation analyses and afterwards polymerizations are performed at the most stable conditions for each analyzed stabilizer. Monomer conversion profiles and final product properties are determined for comparative purposes. Obtained results indicated that the performances of the stabilizers during the polymerizations are not necessarily related to the stabilizing performances observed during preparation of the miniemulsions and that polymer latexes produced with the nonionic surfactant Tween80 presented the most suitable properties for applications in the biomedical field, as this stabilizer presented good stabilizing performances both during miniemulsion preparation and miniemulsion polymerization.

INVESTIGATION OF THE INFLUENCE OF STABILIZERS ON THE VISCOSITY OF THE RECOVERED MIXTURE OF A HYPERTONIC DRINK FOR ATHLETES

When introducing plant and animal protein products, in addition to nutritional value, it is advisable to assess their physicochemical properties and technological indicators, in particular, homogeneity and consistency stability. The aim of research is to determine the effect of consistency stabilizers on the viscosity of a reconstituted hypertonic drink for athletes based on flaxseed cake, sesame seeds and whey protein concentrate. The mass fraction of protein in the model dry mixture of a hypertonic drink, as well as in its individual components by the Kjeldahl method, the mass fraction of fiber – by the gravimetric method, the mass fraction of lipids – by the extraction-gravimetric method, the mass fraction of moisture – by the thermogravimetric method. The mass fraction of ash in the mixtures was carried out by the method of incineration followed by calcining the mineral residue at a temperature of 450 ... 600 °C. The effective viscosity in the reduced samples of mixtures without and with the addition of stabilizers was determined on a rotational viscometer "Rheotest 2". For the planning of the experiment and data processing, mathematical methods were applied using the Microsoft Office Excel 2003 software package. The chemical composition of individual components and a model dry mixture of a hypertonic drink for the nutrition of athletes, including the content of compounds that have a stabilizing effect on the restored product, has been investigated. It has been proved that the effective viscosity of the reconstructed model mixture in comparison with the effective viscosity of the individual components of the mixture nonaditively increases. The mutual influence of the consistency stabilizers (gum arabic (E 414) and carboxymethylcellulose (E 466)) on the value of the effective viscosity of the reconstituted hypertonic drink was investigated. The developed model mixture of a hypertonic drink is recommended to be used for the development of competitive dry mixtures of hypertonic drinks of plant and animal origin for the nutrition of athletes

Defining phenotypes of long-term lithium and valproate response, including combination therapy: a modified application of the Alda scale in patients with bipolar disorders

BackgroundWhen evaluating the long-term treatment response to mood stabilizers using the Alda scale, mood stabilizer combination therapy is typically considered a confounding factor, and patients receiving combination therapy are excluded from the analysis. However, this may result in bias if those under combination therapy are worse treatment responders. This study aims to explore whether the Alda scale is applicable to patients taking lithium and valproate combination therapy. We compared long-term treatment response in patients receiving monotherapy and combination therapy of the two drugs, and investigated clinical correlates of the responses to each drug.MethodsThe study subjects consisted of 102 patients with bipolar I (BD-I) or bipolar II (BD-II) disorder who had been undergoing maintenance treatment with lithium and/or valproate for more than 2 years at a single specialized bipolar disorder clinic. Long-term treatment response was measured using the Alda scale and compared among the lithium monotherapy group, the valproate monotherapy group, and the mood stabilizer combination group. Clinical correlates of long-term treatment response were evaluated in lithium users and valproate users separately.ResultsThere were no significant differences in terms of baseline illness characteristics among groups. The combination group showed the worst treatment response for all the response measurements applied. This group also had the higher rate of ‘poor responder’ with a statistically significant difference compared to valproate group. Older age at onset and (hypo)manic episode at onset showed significant positive associations with total Alda score in lithium users, while comorbid anxiety disorders, obsessive–compulsive disorder and mixed episode showed significant negative associations in valproate users.ConclusionsThe combination group had poorer long-term treatment response but did not show distinct clinical characteristics compared to the monotherapy groups. When exploring the long-term effects of mood stabilizers, excluding patients undergoing combination treatment could result in bias because they may represent a poor response group. The long-term treatment responses of lithium and valproate had different clinical correlates.

Design and experimental investigation of a GA-based control strategy for a low-speed fin stabilizer

Fin stabilizers are widely used for to reduce ship rolling. However, reducing rolling motion at low ship speeds remains a challenge because of uncertainties in ship dynamics, transient and nonlinear hydrodynamic forces of fin. Also the phase difference between the force and fin angle is highly sensitive to ship speed. Herein, an improved control strategy is proposed to avoid these problems and to enhance the anti-roll effect of fin stabilizers. A prediction algorithm based on the radial base function artificial neural network (RBF-ANN) is first used to forecast ship rolling motion, and then the disturbing moment and roll time series are estimated. Uncertainty of disturbances in roll dynamics are encapsulated in the predictive algorithm. Moreover, an inversion method based on the genetic algorithm can be applied to minimize differences between the disturbing moment and stabilizing moment. A ship model is introduced to verify the proposed control strategy. Forced roll tests were carried out using the ship model to determine the optimal fin profile and maximum control moment. Anti-roll experiments and simulations were performed to verify the improved control strategy.

ДОСЛІДЖЕННЯ ВПЛИВУ СВІТЛОСТАБІЛІЗАТОРІВ НА СВІТЛОСТІЙКІСТЬ ЗАБАРВЛЕНОГО АКТИВНИМИ БАРВНИКАМИ БАВОВНЯНОГО ТРИКОТАЖУ

The goal of the work is to study the effect of light stabilizers on the lightfastness of colours of cotton knit fabric dyed with reactive dyes. The study was carried out using a cotton 1+1 rib knit fabric with a surface weight of 150 g/cm2, prepared by the combined technology of boiling and bleaching. Dyeing of the fibrous material was carried out using Bezaktiv reactive dyes in a batch method at a concentration of 0.3% by weight of the material. UV absorbers 2,5-dihydroxyacetophenone, 2,4-dihydroxybenzophenone, phenyl salicylate and antioxidants – diatomic phenols – hydroquinone, pyrocatechol and resorcinol were chosen as light stabilizers. In the work, the light stabilization of cotton knit fabric was carried out after dyeing with reactive dyes and washing the dyed knit material. The technological mode of application of the studied light stabilizers was to impregnate a knit fabric, drying and curing the material. The individual effect of light stabilizers on the colour change of dyed knit fabric samples and the photodestruction kinetics of dyes were investigated. The insolation of the samples was carried out on a device with a mercury-tungsten lamp RF 1201 BS ("REFOND"). After treatment and insolation, the total colour difference dE of knit samples were determined compared to untreated material using a TCR-200 colorimeter ("PCE Instruments"). The results obtained indicate that the change in the initial colours after treatment with light stabilizers depends on the colour of the dye and on the type of light stabilizer. The greatest colour changes are observed with phenyl salicylate, pyrocatechol and resorcinol. It has been established that UV absorbers exhibit a light-shielding effect to a greater extent than antioxidants. The obtained experimental results also indicate the need for the simultaneous use of UV absorbers and antioxidants in order to efficiently stabilize dyed cotton knit fabric. The individual effect of light stabilizers – UV absorbers and antioxidants – on the lightfastness of colours of cotton knit fabric dyed with Bezaktiv reactive dyes is investigated. It was established that for effective light protection of colours of cotton knit fabric dyed with reactive dyes, the simultaneous use of UV absorbers and antioxidants is necessary

Investigating the effect of different types of cocoa powder and stabilizers on suspension stability of cinnamon-cocoa drink.

Sedimentation of particles in cocoa drink is a technological challenge for the food industry. This study investigates the effect of different stabilizers (alginate, xanthan gum or carrageenan) on the suspension stability of cinnamon-cocoa drink made from 2 types of cocoa powder (natural or alkalized). Rheological and microstructural properties determination was used to examine the stabilization effect mechanism. The cocoa powder characteristic was investigated to study the correlation between cocoa powder properties and suspension stability. The results showed that xanthan gum is the most effective stabilizer to prevent particle sedimentation of the cinnamon-cocoa drink. Xanthan gum formed a network entrapping the particles. It increased the viscosity from 2.47 to 70.44mPas at a shear rate of 10/s. The drink formulated with alkalized cocoa powder has a better stability than that formulated with natural cocoa powder. However, at the concentration of 0.1% (w/v), xanthan gum could prevent sedimentation regardless the type of cocoa powder. The addition of xanthan gum up to 0.1% (w/v) had no significant effect on pH and antioxidant properties of the cinnamon-chocolate drink with a minor change in the lightness (L*) parameter. As such, the value of L*, pH, phenolic content and antioxidant activity of the cinnamon-cocoa drinks remained stable at around 22.5 ± 0.9, 7.2 ± 0.1, 0.31 ± 0.5mg epicatechin equivalent /ml and 0.44 ± 0.3mg tannic acid equivalent /ml, respectively. This study can be useful for the food industry to define a novel strategy to produce "ready-to-drink" cocoa-based beverage with prolonged suspension stability.

Enzyme Stability in Nanoparticle Preparations Part 1: Bovine Serum Albumin Improves Enzyme Function.

Enzymes have gained attention for their role in numerous disease states, calling for research for their efficient delivery. Loading enzymes into polymeric nanoparticles to improve biodistribution, stability, and targeting in vivo has led the field with promising results, but these enzymes still suffer from a degradation effect during the formulation process that leads to lower kinetics and specific activity leading to a loss of therapeutic potential. Stabilizers, such as bovine serum albumin (BSA), can be beneficial, but the knowledge and understanding of their interaction with enzymes are not fully elucidated. To this end, the interaction of BSA with a model enzyme B-Glu, part of the hydrolase class and linked to Gaucher disease, was analyzed. To quantify the natural interaction of beta-glucosidase (B-Glu,) and BSA in solution, isothermal titration calorimetry (ITC) analysis was performed. Afterwards, polymeric nanoparticles encapsulating these complexes were fully characterized, and the encapsulation efficiency, activity of the encapsulated enzyme, and release kinetics of the enzyme were compared. ITC results showed that a natural binding of 1:1 was seen between B-Glu and BSA. Complex concentrations did not affect nanoparticle characteristics which maintained a size between 250 and 350 nm, but increased loading capacity (from 6% to 30%), enzyme activity, and extended-release kinetics (from less than one day to six days) were observed for particles containing higher B-Glu:BSA ratios. These results highlight the importance of understanding enzyme:stabilizer interactions in various nanoparticle systems to improve not only enzyme activity but also biodistribution and release kinetics for improved therapeutic effects. These results will be critical to fully characterize and compare the effect of stabilizers, such as BSA with other, more relevant therapeutic enzymes for central nervous system (CNS) disease treatments.

Rheological and strength performances of cold-bonded geopolymer made from limestone dust and bottom ash for grouting and deep mixing

This paper aims to research the potential use of cold-bonded geopolymer stabilizer made from limestone dust and bottom ash for grouting and deep soil (clay) mixing. For this purpose, the rheology and strength performances of the cement (PC)-based grouts with the stabilizers of limestone dust (LD), bottom ash (BA), geopolymerized cold-bonded limestone dust (GLD), and geopolymerized cold-bonded bottom ash (GBA) were investigated. The rheometer tests were conducted for the rheological performances at a wide range of stabilizer replacement (0–100%) and water/binder (w/b) ratio (0.75–1.5). Using proper replacements from the grout rheology, the unconfined compressive strength (UCS) tests (7 days, 28 days) were performed for the grouting (w/b = 1) and deep mixing (w/b = 1–1.25). The effect of stabilizer on the failure patterns was also examined from specimens of UCS tests. From the experimental work, the rheology of grout mixtures indicated (i) the adequacy of low amount of stabilizer replacements (< 50%); (ii) the dilatant behavior similar to PC; (iii) a decreasing trend of the shear stress, apparent viscosity, yield stress, and plastic viscosity with the increased w/b; (iv) slight to moderate responses of PC mostly; and (v) a potentially favorable rheology of cold-bonded stabilizers (GLD, GBA) for grout flow and workability regarding the yield stress and plastic viscosity. From the strength tests of grout mixtures (0–40%), the GBA additions yielded higher UCS performances for the grouting. For the deep mixing, both the additions of GLD and GBA were found more successful for the strength. The failure planes of UCS specimens were observed independent from the stabilizer types and dosage rates that dominantly failed in axially or near-axial splitting. From the study, the contributions of GLD and GBA from the potential of cold bonding are relatively promising for grouting and deep mixing.

Weath ering Performance of Beech Wood Coated with Acrylic Paint Containing UV Stabilizers of Dihydroxy Benzophenone and Nano Zinc Oxide

In this study, the effect of UV stabilizers (dihydroxy benzophenone and nano zinc oxide) on the weathering degradation of water-based acrylic coating on beech wood was investigated. The wood specimens were coated by brush and then weathered naturally for six months. The obtained results showed that the use of nano zinc oxide reduced color changes and mold growth on the surface of weathered samples. However, the results of contact angle, pull-off adhesion, colorimeter and FTIR revealed that the dihydroxyl benzophenone was not effective in preventing weathering degradation of coated wood.

Effect of Au nanoparticles on the gas sensitivity of nanosized SnO2

The effect of the nanosized gold state on the adsorption-sensitive properties of tin dioxide under the detection of СО, СН4 and С2Н5ОН vapours has been studied. Different techniques that allow obtaining gold particles with the average size ranging from 1.9 ± 0.1 nm to 3.5 ± 0.5 nm were applied. The structural features and the surface state of SnO2 and SnO2–Au materials have been studied by using SEM, TEM, XPS, FTIR and UV–Vis spectroscopy. It has been found that an increase in the sensor response to СО, СН4 and С2Н5ОН vapours is achieved by adding gold in the form of colloid particles with the size range of 1.9–3.5 nm to SnO2·nH2O sol. The SnO2–Au layers with the larger particles (3.5 nm) demonstrate the highest response to С2Н5ОН while SnO2–Au (1.9 nm) composite is the most sensitive to CO and СН4. It has been shown that a selective detection of СН4 and СО in gas mixtures is possible by adjusting the voltage to be applied to SnO2–Au (1.9 nm) sensor. The enhanced sensitivity of the sensor to methane is caused by the nanosized state of both SnO2 and Au components as well as by the modifying effect of sulphur-containing stabilizer of Au particles.

Output-volatility reducing effects of automatic stabilizers: Policy implications for EMU member states

In this paper, we empirically explore the output-volatility reducing impact of automatic stabilizers and look in detail at their policy implications for selected EMU member states comprising Austria, Finland, France, Germany, Ireland, Italy, the Netherlands, Portugal, and Spain for the period 1995–2017. Overall, the results suggest that automatic stabilizers deliver a statistically significant, but fairly weak, counter-effect on output volatility in the short run. More specifically, output-volatility responses to automatic stabilizers by a reduction between −0.012 and −0.097 percentage points depending on the proxy measure used for automatic stabilizers. However, the automatic stabilizing impact from taxes and government spending is statistically insignificant in the long run. The results point to two main policy implications: i) automatic stabilizers are an important fiscal mechanism just for the short-run output stabilization, but their output-volatility offsetting role and power are largely subject to proxy measures used for automatic stabilizers; ii) no matter what proxy measures are used, automatic stabilizers largely produce a weak stabilizing performance in dampening short-term output volatility. So, from a macroeconomic policy standpoint, it can be safely claimed that automatic stabilizers can just be an integral part of discretionary fiscal policy rather than being an alternative to it.

Effects of stabilizers on sustainability, activity and decolorization performance of Manganese Peroxidase enzyme produced by Phanerochaete chrysosporium

Manganese Peroxidase (MnP), is one of the most promising lignin depolymerization enzymes, which has been widely used for degradation purposes. Nevertheless, MnP tends to lose activity rapidly during its maintenance phase and degradation process, especially in the inevitable presence of hydrogen peroxide. This study aimed to improve MnP efficiency produced by Phanerochaete chrysosporium, via enhancing its sustainability. In this context, the effects of MnO2, Fe3O4, PEG, Veratryl Alcohol (VA), and DMSO as stabilizing agents on MnP activity were explored both in vivo and in vitro. During in vivo experiments, heterogeneous Fe3O4 was found to be the desirable choice to enhance MnP production, obtaining a maximum MnP activity of 2149 U/L, which was a 67 % boost over the stock configuration. Also, in vitro studies demonstrated a noticeable increase in the stability of the extracted MnP from 8 days up to 14, 23, 23, 25, and 26 days by the addition of MnO2, VA, Fe3O4, PEG, and DMSO stabilizers, respectively. The efficiency of stabilizers on degradation ability of MnP was also examined; optimum conversion of model dyes viz., AO7 and CV, were improved 36.17 and 126.51 % in response to stabilizers, respectively. The inclusion of stabilizers managed to improve sustainability, performance, and cost-effectiveness of the biological water treatment process.

Proposing the sweet solution preference test as a screening assay for anti-manic effects of mood stabilizers

BackgroundThere is a desperate need for in-vivo behavioral screening tests for anti-manic effects. The frequently used psychostimulant-induced hyperactivity test appears to have lower validity than previously described, but other quick, simple and high throughput tests are currently unavailable. New methodIn the context of modeling the behavioral facets of mania, we previously suggested that the sweet solution preference test (SSP) in naive mice might have predictive validity for screening anti-manic effects. The current study further examined this proposal by testing the effects of lithium, valproate and imipramine on SSP in three strains of mice (male mice from the black Swiss, ICR and C57bl/6 strains) and an exploratory test in females (black Swiss strain). ResultsData demonstrate that lithium and valproate at appropriate dosing schedules significantly and reliably reduce SSP in all three strains (including in females) but that the antidepressant imipramine has no effects. Comparison with existing methodsThe results support the utilization of the SSP as mice screening model for anti-manic effects of drugs with stronger predictive validity compared with other methods. ConclusionsThe SSP is not a comprehensive model for bipolar disorder but it has good predictive validity and strong practical value that can be applied towards simple and fast screening of large numbers of animals, without the need for specialized equipment or complicated/prolonged procedures. We therefore propose that the SSP is an advantageous screening assay for testing novel mood stabilizing drugs for anti-manic properties.

Addition of Anionic Polysaccharide Stabilizers Modulates In Vitro Digestive Proteolysis of a Chocolate Milk Drink in Adults and Children.

There is a need to better understand the possible anti-nutritional effect of food stabilizers on the digestibility of important macronutrients, like proteins. This study hypothesized that the anionic nature of κ-, ι-, λ-, Carrageenan (CGN) and xanthan gum directs their interactions with food proteins leading to their subsequent attenuated digestive proteolysis. Model chocolate milk drinks were tested for their colloidal properties, viscosity and proteolytic breakdown in adults and children using in vitro digestion models coupled with proteomic analyses. SDS-PAGE analyses of gastro-intestinal effluents highlight stabilizers hinder protein breakdown in adults and children. Zeta potential and colloidal particle size were the strongest determinants of stabilizers’ ability to hinder proteolysis. LC-MS proteomic analyses revealed stabilizer addition significantly reduced bioaccessibility of milk-derived bioactive peptides with differences in liberated peptide sequences arising mainly from their location on the outer rim of the protein structures. Further, liberation of bioactive peptides emptying from a child stomach into the intestine were most affected by the presence of ι-CGN. Overall, this study raises the notion that stabilizer charge and other properties of edible proteins are detrimental to the ability of humans to utilize the nutritional potential of such formulations. This could help food professionals and regulatory agencies carefully consider the use of anionic stabilizers in products aiming to serve as protein sources for children and other liable populations.

Comparison of sintering behavior and reinforcing mechanisms between 3Y-TZP/Al2O3(w) and 12Ce-TZP/Al2O3(w) composites: Combined effects of lanthanide stabilizer and Al2O3 whisker length

The densification behavior, microstructural development, toughening and strengthening mechanisms of Al2O3 whisker-reinforced 3Y-TZP and 12Ce-TZP composites were systematically and comparatively investigated with varying whisker lengths. Compared with 3Y-TZP/Aw composites, the presence of a Ce-Al-Si-O amorphous phase, caused by the addition of Al2O3 whiskers, promoted the densification and grain growth of 12Ce-TZP/Aw composites. Crack deflection and bridging are proposed as the primary toughening mechanisms for 3Y-TZP/Aw composites, while the t-m martensitic transformation would dominate the toughening and strengthening processes of 12Ce-TZP/Aw composites. Changes in Al2O3 whisker length would vary the distributions of internal stress and amorphous phase within the ceria-stabilized ZrO2 matrix, and hence affect the toughening and strengthening results. It indicates that effective toughening and strengthening of the Al2O3 whisker-reinforced TZP composites can be achieved by taking advantage of collaborative engineering control on the reinforcement morphology and the interface chemistry/structure.

Reductive immobilization of uranium by stabilized zero-valent iron nanoparticles: Effects of stabilizers, water chemistry and long-term stability

Uranium is one of the most commonly detected radionuclides in the environment. Of the two most predominant oxidation states, U(VI) is much more soluble, mobile and toxic than U(IV). Consequently, converting U(VI) to U(IV) can facilitate the removal of U from water and reduce its mobility and biological exposure. In this work, stabilized zero-valent iron (ZVI) nanoparticles were prepared using starch or carboxymethyl cellulose (CMC) as stabilizers and then tested for reductive removal of U(VI) from simulated groundwater. Nearly 100% removal of U(VI) (initial U = 25 mg/L) was achieved using CMC-stabilized ZVI (Fe = 35 mg/L) at pH 6. In pH range of 6–9, the lower pH favored the reaction. CMC-ZVI nanoparticles presented better deliverability than starch-ZVI, while bare ZVI nanoparticles was almost trapped in the soil column. CMC-ZVI worked effectively in the presence of a model humic acid (up to 10 mg/L as TOC) and bicarbonate (1 mM), though higher dosages of the ligands inhibited U(VI) removal. After treatment, no re-mobilization of U was detected when aged for 6 months under anoxic conditions and the addition of strong ligands only remobilized U(VI). When exposed to oxic conditions, the immobilized U will be partially oxidized and remobilized due to the ingress of atmospheric O2 and CO2. In terms of toxicity reduction, the ZVI treated U had almost no inhibition for natural bacteria activity, while dissolved U(VI) showed significant inhibitive effects. The CMC-ZVI nanoparticles may serve as effective reactive materials to facilitate immobilization of U(VI) in groundwater, which in turn can greatly mitigate the human exposure and toxic effects of U on biota.

Polymer stabilizer effect on the nickel-copper ferrite ability to reduction

The effect of polymers (polyvinyl alcohol, polyvinylpyrrolidone) involved in the synthesis of nickel-copper ferrite Ni0.5Cu0.5Fe2O4 on its phase composition changing under heawt (500–900 °C) and electrochemical reduction was investigated. Electrocatalytic activity of various levels of Fe-Cu-Ni-composites formed by the reduction of the mixed ferrite samples was established. An influence of heat treatment temperature on their electrocatalytic activity in the electrohydrogenation of acetophenone was studied.

Thermal degradation kinetics of calcium stearate/PVC composite

Thermogravimetric analysis (TGA) and non-isothermal multiple scan rate method were used to study the effect of calcium stearate on the thermal degradation of PVC. The results show that the thermal decomposition process of calcium stearate/PVC composite includes two stages, which occur at 361–402 ​°C and 552–585 ​°C, respectively. The apparent activation energy of the 1st stage calculated by Kissinger, Starink, Friedman and Flynn-Wall-Ozawa method is 93.22, 87.18, 94.81 and 92.13 ​kJ ​mol−1, respectively. The decomposition reaction in the 1st stage is controlled by the F1 mechanism, of which differential and integral equation is f(α) ​= ​1/(2α), g(α) ​= ​α2, respectively. This work provides a way to study the effect of heat stabilizers on the thermal stability of PVC.