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In this research, a kind of non-carbonized reduced graphene oxide (RGO)-cellulose nanofibers (CNF) film is constructed by a combination of filtration and chemical reduction. In the hybrid, RGO enhances conductivity of CNF, and CNF as an idea spacer not only prevents stacking of RGO but also gives the film good mechanical properties including mechanical strength and flexibility. The synergistic effect of both endows the film with good electrochemical storage performance and outstanding mechanical properties. The hybrid film can be directly assembled into a symmetrical supercapacitor that shows an outstanding cycle stability, excellent rate performance, good mechanical strength and flexibility. Moreover, the film presents a high specific capacitance of 120 mF cm−2, energy density of 536 μWh cm−2 (32 Wh kg−1) and power density of 193 mW cm−2 (53 kW kg−1). Additionally, the film can be used as a substrate to graft other components. [ABSTRACT FROM AUTHOR]

A strategy was proposed to modify cotton fabrics (CFs) by dipping-padding procedure using graphene oxide (GO) and aminofullerene (C60), and then the flexible reduced GO/fullerene fabric-based ion sensors (RGO/C60@CF) were prepared by chemical reduction method. Large amounts of zero-dimension of fullerene spheres were embedded in RGO sheets, and could exhibit different dipole–dipole interactions on various cations or anions with different sizes by virtue of their electron deficiency characteristics, which made RGO/C60@CF show different resistivity to different ions, thus endowing the modified fabrics with responsiveness to different ions. When the relative content of fullerene to graphene was 5%, the resistivity of the modified fabric (RGO/CF60@CF-5) was significantly different to different ions, i.e., the larger the ion radius, the greater the resistivity of the modified fabrics, and even if the ion concentration was only 1 mmol/L, RGO/C60@CF-5 exhibited good sensitivity. In addition, the fabric-based ion sensors also showed different sensing properties for different type of sweat, and their sensitivity only changed slightly after 1000 times of 180° bending. This work provides a basis for the design of the next generation of intelligent ion sensors with high sensitivity and flexibility. [ABSTRACT FROM AUTHOR]

This study presents a systematic on-site remediation case involving both heavy metal and organic contaminants in soil and groundwater in a historically industrial-used site in Shanghai, China. Lab-scale experiments and field tests were conducted to determine the optimum parameters for the removal of contaminants in soil and groundwater. It has been found that the remediation goal of hexavalent chromium in soil could be achieved with the mass content of added sodium hydrosulfite and ferrous sulfate reaching 3% + 6%. The total chromium in the groundwater was effectively removed, when the mass ratio of sodium metabisulfite was not less than 3 g/L, and the added quick lime made pH value not less than 9. The concentrations of arsenic and 1,2-dichloropropane in the groundwater decreased evidently after extraction and mixing of groundwater. The pH and calcium chloride dosage added should be larger than 9.5 and 5 g/L, respectively, to remove phosphate in groundwater. The removal efficiency of those contaminants was examined and evaluated after the on-site remediation. The results demonstrated that it was feasible to use the chemical reduction and solidification/stabilization methods for the on-site ex situ remediation of this site, which could be referenced for the realistic remediation of similar sites. [ABSTRACT FROM AUTHOR]

Specific features of the synthesis of stable silver nanoparticles by chemical reduction with agents differing in the reducing ability were studied using spectrophotometry, photon correlation spectroscopy, and scanning electron microscopy methods. The antimicrobial activity of the silver-containing sols synthesized was evaluated in tests with clinical strains (Staphylococcus aureus and Escherichiacoli), and its dependence on the reduction conditions and, accordingly, on the size of the resultant particles was revealed. The synthesized sols of silver nanoparticles with sizes below 50 nm proved efficient in protecting cellulosic textile materials against attacks by natural complex of microflora and by soil microflora. [ABSTRACT FROM AUTHOR]

Low-cost plant and algal biomass are increasingly demanded as a source of proteins, and also, peptides and amino acids are gaining interest for their biological and functional properties. The reduction in chemicals, time and energy, and the integral valorization of the raw materials in the framework of biorefineries are major concerns in the development of environmentally friendly processes. Subcritical water technology is an efficient green technique useful both for extraction and for hydrolysis of protein and other fractions (lipid, carbohydrates, phenolics). However, adequate selection of operational conditions is needed in order both to maximize their extraction yield and to avoid degradation into monomeric units and decomposition products. This review summarizes the major features of subcritical water–based processes for the extraction/hydrolysis of protein. In order to valorizate other valuable fractions from agro-food wastes and algal biomass, optimal conditions should be established as a compromise solution. Alternatively, stagewise operation to sequentially obtain the target fractions could be desirable. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been used as a promising alternative to antibiotics in poultry feed. In this study, silver-doped silica nanoparticles (SiO2@AgNPs) were prepared in powder form, using starch, via the chemical reduction method and sol–gel technique followed by full characterization. SiO2@AgNPs were added to the poultry diet at three doses (2, 4, and 8 mg/kg diet). The safety of the oral dietary supplementation was estimated through the evaluation of the growth performance and hematological, biochemical, and oxidative parameters of birds. Moreover, the immunohistochemical examination of all body organs was also performed. Results of this study showed that SiO2@AgNPs have no negative effects on the growth performance and hematological, biochemical, and oxidative parameters of birds. Moreover, the immunohistochemical examination revealed the minimum inflammatory reactions and lymphoid depletion under a dose level of 8 mg/kg. In conclusion, SiO2@AgNPs could be considered as a promising and safe nano-growth promoter in broilers when added to poultry diet under a dose level of 4 mg/kg diet. [ABSTRACT FROM AUTHOR]

Although numerous studies have explored various impacts of Internet use, few have investigated the linkage between Internet use and chemical fertilizer use in developing economies. This study examines the influences of Internet use and related promotion policy on chemical fertilizer use based on a nationwide dataset including China's 7766 rural households. The baseline regression results show that Internet use reduced chemical fertilizer use significantly. The mechanism analysis unveils the mediation role of human capital; Internet use increased farmers' human capital and then reduced chemical fertilizer use. In addition, the difference-in-difference method is employed to examine the effects of Internet promotion policy and the findings reveal that the promotion policy could help reduce farmers' use of chemical fertilizer. Finally, both propensity score matching-DID model and a two-stage instrumental variable model are used to address potential endogeneity issues associated with Internet use, and results indicate that the empirical results are robust. Our findings suggest that improving the availability of broadband access in a rural area, promoting Internet-related training and education, and more government's investment in rural ICTs infrastructure can contribute to the reduction of chemical fertilizer use. [ABSTRACT FROM AUTHOR]

Carbon-supported PtSnCu/C, Pt3Sn/C, Pt3Cu/C and Pt/C electrocatalysts were synthesized by chemical reduction of metal precursors in ethanol reflux. These materials were characterized by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and applied to the ethanol electro-oxidation in acidic medium. The reaction kinetics was studied by cyclic voltammetry and the mechanism was explored by in situ Fourier transform infrared spectroscopy (FTIR). The investigated materials presented chemical composition close to the nominal ones. XRD results indicated the formation of solid solution of Pt and Cu and/or Sn in the bi and tri-metallic materials. The particle size distribution was narrow with mean particle size of around 3 nm. A homogeneous distribution of the nanoparticles over the carbon support was evidenced. The investigated catalysts were active towards the ethanol oxidation reaction in acidic medium and led to the formation of CO2 and carbonyl compounds, as evidenced by FTIR. PtSnCu/C and Pt3Cu/C started to produce CO2 at 0.70 V vs. RHE, while this product was detected only at 0.75 V and 0.80 V vs. RHE on Pt and Pt3Sn/C, respectively, suggesting that Cu improves the dissociative adsorption of ethanol. [ABSTRACT FROM AUTHOR]

Nickel-aluminum bilayers and multilayers are commonly used in reactive systems because of their high heat of mixing. Traditionally, the layers are sputter deposited, an expensive and time-consuming process. In this article, a chemical reduction technique, electroless nickel-phosphorous (EN) deposition, is used for formation of the Ni-Al bilayer using a pure Al substrate. Traditionally, EN deposition on Al requires surface activation due to the native oxide layer. Here, we tune the bath pH to dissolve this oxide layer, such that deposition can be obtained without surface activation. Deposition kinetics is measured by tracking the mass change with time and temperature, and we extracted the activation energies at two different pH values. At pH 7, the energy is 98.7 kJ/mol and reduces to 55 kJ/mol at a pH of 8. The process can also be extended to aluminum powders and flakes in order to form reactive core–shell structures. [ABSTRACT FROM AUTHOR]

In this work, we fabricated gold nanoparticles (AuNPs) capped with both polyvinyl pyrrolidone (PVP) and iodine (I2) to act as efficient chemiluminescent coreactants for luminol. AuNPs synthesis was based on the direct chemical reduction of Au3+ with NaBH4 in the presence of PVP-I2 complex. The successful synthesis of PVP-I2@AuNPs was confirmed with scanning electron microscopy (SEM) and UV-vis spectrophotometry. Chemiluminescence (CL) intensity of luminol was greatly enhanced, upon its chemical reaction with chemisorbed I2 on AuNPs surfaces owing to the excellent catalytic activity of AuNPs. The PVP-I2@AuNPs/luminol CL sensing system was successfully applied for determination of Hg2+ ions and the results displayed linearity in a wide range from 0.5 to 2000 nM and an ultrasensitive response to 1.0 nM Hg2+. The detection limit of Hg2+ ions was 0.1 nM, which was 100 times lower than the limit value (10 nM) defined by the U.S. Environmental Protection Agency in drinkable water. This ultrasensitive luminogenic system for Hg2+ detection also exhibited excellent selectivity among 13 types of metals, suggesting that the luminol/PVP-I2@AuNPs system is a promising sensor for real-time detection of Hg2+. [ABSTRACT FROM AUTHOR]

It is well known that the lack of an effective treatment of tuna wash processing wastewater may pose substantial environmental and public health hazards. The present work investigates the performance of biological treatment of tuna wash processing wastewater (TWPW) by using Yarrowia lipolytica. Under optimized experimental conditions (pH "6.40–6.50" and 29 °C), Y. lipolytica reduced the pollution level of the crude and the diluted TWPW after only 7 days of incubation. The Yarrowia treatment leaded to a reduction of 66% chemical oxygen demand, 69.8% total organic carbon, 66% salinity, and phosphorus total (100%) removal of the crude TWPW, while the treated-diluted TWPW revealed significant reductions in chemical oxygen demand and total organic carbon (75% and 74%, respectively), as well as salinity (68%). Interestingly, a total removal of nitrogen and phosphorus from the diluted TWPW was obtained. Under high salinity, an important Y. lipolytica biomass of 5 g L−1 is produced with high levels of lipids and protein contents at around 336 ± 12.2 mg g−1 and 302.15 ± 5.44 mg g−1, respectively. The phytotoxicity assessment of the treated TWPW on fenugreek seeds shows promising results, which reveals the good performance of Yarrowia treatment in reducing the toxicity of this wastewater. [ABSTRACT FROM AUTHOR]

Hydrogenation of 1,5,9-cyclododecatriene in the presence of nanostructured nickel catalysts in a flow-through reactor at atmospheric hydrogen pressure was studied. NaX zeolite was used as a support. Nickel nanoparticles on the support surface were prepared by chemical reduction of the precursor (NiCl2) with NaBH4 and NH2NH2. The influence exerted on the yield of hydrogenation products by the nominal residence time of the gas phase in the reaction zone and by the process temperature was considered, and the catalyst operation life was analyzed. The catalysts showed high activity and allowed preparation of cyclododecane in ~100% yield at a process temperature of up to 160°С. [ABSTRACT FROM AUTHOR]

This study reported comprehensive and systematic investigations on size and shape control of silver nanoplates (SNPs) through a simple synthesis route where individual effects of each reactant on surface plasmon resonance of silver nanoplates were thoroughly investigated. SNPs were successfully fabricated via chemical reduction of AgNO3 with the aid of TSC, PVP, NaBH4, and H2O2 as a primary capping agent, secondary capping agent, reducing agent, and oxidative etchant, respectively. The role and effects of each reagent on the size and uniformity of SNPs during the synthesis were deeply investigated. The results showed that both TSC and H2O2 played critical roles in the growth of SNPs. Sufficient amount of TSC in the solution ([TSC]:[Ag+] molar ratio ≤ 22.5) would favor the formation of small-sized SNPs, while large-sized SNPs could be obtained at an excessive concentration of TSC. In addition to TSC, H2O2 was also essential for the formation of SNPs whose size increased with the addition of H2O2. In contrast, PVP did not play a major role in the formation of SNPs. It functioned as a secondary capping agent to prevent the formation of larger SNPs and facilitated the production of small-sized SNPs with equal uniformity. This role of PVP was particularly significant at the low level of TSC. The results were crucial for deeply understanding the individual effects of each reagent on the size and uniformity of SNPs so as to control the size and shape of SNPs for better surface-enhanced Raman scattering (SERS) signals of 4-mercapto benzoic acid (4-MBA). [ABSTRACT FROM AUTHOR]

The biogenic tailoring of silver nanoparticles using plant extract is becoming an attractive approach in the current scenario. Manilkara zapota (MZ) is well known for its antibacterial, hepato-protective, anti-inflammatory, anti-tussive, anti-fungal, anti-tumour, and free radical scavenging potential. Its plants extract is a rich source of secondary metabolites. Nowadays, silver nanoparticles (AgNPs) have been advocated for a variety of biomedical applications. In present work, silver nanoparticles have been synthesized using an aqueous extract of MZ, physicochemically characterized and finally evaluated for antimicrobial effects, catalytic reduction/degradation of organic dyes and cytotoxicity. The nanosized AgNPs (~ 84 nm) were found to possess prominent antibacterial potential against gram positive and gram negative pathogens (MIC 50 μg/ml) in comparison to native plant extract. Moreover, these particles were found to be non-toxic and efficient eradicators of environmental toxicants via rapid catalytic reduction of toxic chemicals and dyes. Altogether, these results suggest promising potential of these nanoparticles that can be used as multifunctional agents for future biomedical applications. [ABSTRACT FROM AUTHOR]

The In Situ Chemical Reduction (ISCR) process was tested in a nitisol in a French Caribbean banana plantation using five different soil amendments. The addition of 2.8% or 4.0% of Zero Valent Iron (ZVI; dw/dw, 2 different trial plots) in the 0–40-cm soil layer lowered the initial chlordecone (CLD) concentration by up to 74% or 69% in 37 days or 94 days, with 75% of the decrease achieved after only 21 or 24 days of treatment depending on the trial plot. The addition of commercially available Daramend® was also tested by applying the 6% dose (dw/dw) recommended by the manufacturer and using either the regular alfalfa-based product or a bagasse-based product specifically formulated for the study. Both significantly lowered CLD concentrations, but to a lesser extent than with the ZVI-only amendment. A bagasse-ZVI mixture prepared on site produced results slightly better than the two Daramend®. The percentage decreases in CLD concentrations were correlated with the negative redox potentials achieved. In all the trial plots, dechlorinated transformation products appeared in the soil and soil water as the CLD concentrations decreased, with H atoms replacing up to 4 and 7 of the 10 Cl atoms, respectively. None of these degradation products appeared to accumulate in the soil or soil water during the treatment. Instead, the reverse occurred, with an overall downward trend in their concentrations over time. The effects of ISCR treatment on agronomic and human health–related parameters were measured in three different crops. The radishes produced with some treatments were visually of lower quality or smaller in size than those grown in the control plots. Lower yields were observed for the cucumbers and sweet potatoes grown after applying the bagasse-based amendments. Mortality among cucumber seedlings was observed after treatment with ZVI only. Simple operational solutions should suffice to remedy these negative agronomic effects. As regards human health–related effects, the CLD concentrations in radishes grown with three of the amendments were significantly lower than in the two control plots and well below the maximum residue level (MRL), which was substantially exceeded in the radishes grown on untreated soil. For cucumbers, the treatments with regular Daramend® and with a local bagasse-ZVI mixture produced fruits with CLD below the MRL and also below the concentrations in one of the two control plots. As for the sweet potatoes, adding a bagasse-ZVI mixture had a significant positive effect by decreasing contamination below the levels in the two control plots and below the MRL. [ABSTRACT FROM AUTHOR]

In situ chemical reduction (ISCR) has been identified as a possible way for the remediation of soils contaminated by chlordecone (CLD). Evidences provided by the literature indicate an association between the development of prostate cancer and CLD exposure (Multigner et al. 2010). In a previous in vitro study, we demonstrated that the two main dechlorinated CLD derivatives formed by ISCR, CLD-1Cl, and CLD-3Cl have lower cytotoxicity and proangiogenic properties than CLD itself (Legeay et al. 2017). By contrast, nothing is known on the in vivo proangiogenic effect of these dechlorinated derivatives. Based on in vitro data, the aims of this study were therefore to evaluate the in vivo influence of CLD and three of its dechlorinated metabolites in the control of neovascularization in a mice model of prostate cancer. The proangiogenic effect of CLD and three of its dechlorinated derivatives, CLD-1Cl, CLD-3Cl, and CLD-4Cl, was evaluated on a murine model of human prostate tumor (PC-3) treated, at two exposure levels: 33 μg/kg and 1.7 μg/kg respectively reflecting acute and chronic toxic exposure in human. The results of serum measurements show that, for the same ingested dose, the three metabolite concentrations were significantly lower than that of CLD. Dechlorination of CLD lead therefore to molecules that are biologically absorbed or metabolized, or both, faster than the parent molecule. Prostate tumor growth was lower in the groups treated by the three metabolites compared to the one treated by CLD. The vascularization measured on the tumor sections was inversely proportional to the rate of dechlorination, the treatment with CLD-4Cl showing no difference with control animals treated with only the vehicle oil used for all substances tested. We can therefore conclude that the proangiogenic effect of CLD is significantly decreased following the ISCR-resulting dechlorination. Further investigations are needed to elucidate the molecular mechanisms by which dechlorination of CLD reduces proangiogenic effects in prostate tumor. [ABSTRACT FROM AUTHOR]

A sensitive and selective assay based on liquid chromatography–tandem mass spectrometric method was developed for quantification of phorate in river water. The chromatographic separation of phorate was achieved on Zorbax C18 column using two mobile phase consisting 0.1% formic acid in methanol, and 0.1% formic acid in MilliQ water (v/v ratio of 96:04) by isocratic elution method at a flow rate of 300 µL/min. The quantification was carried out using multiple reaction monitoring transitions of m/z 261/75 for phorate. The lower limit of detection and limit of quantification for the developed UPLC-MS/MS was 0.08 ng/mL and of 0.19 ng/mL respectively. The assay was validated for selectivity, linearity, accuracy and precision. The developed assay was then employed for quantification of phorate in river water and wetland treated water. The role of constructed wetlands (CW) in phorate removal was established in this study. The removal efficiency of phorate by Constructed Wetland was found to be 60–90% along with an overall 70–90% reduction in chemical oxygen demand (COD), biological oxygen demand (BOD) and phosphorus (P). [ABSTRACT FROM AUTHOR]

In this work, a novel nanocomposite containing silver nanoparticles (AgNPs) embedded poly(1-naphthylamine) nanospheres (Ag/PNA) was prepared by in situ chemical reduction of silver nitrate. The structure, composition, and morphology of the prepared Ag/PNA nanocomposites were established by Fourier transform infrared spectrometry, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the PNA and Ag/PNA-modified carbon paste electrodes were analyzed using cyclic voltammetry (cyclic voltammogram) and electrochemical impedance spectroscopy. It is observed that the electrochemical and charge transfer characteristics of PNA have significantly enhanced upon the incorporation of AgNPs. The prepared Ag/PNA nanocomposite has shown impressive electrocatalytic and electrochemical sensing performance toward H2O2. Remarkably, the present Ag/PNA-based enzymeless voltammetric H2O2 sensor showed a wide detection range in the concentration range of 1–3000 μM with a lower detection limit of 0.972 μM. The study revealed that Ag/PNA-modified carbon paste electrodes are an ideal platform for the fabrication of low-cost non-enzymatic H2O2 sensor with high sensitivity, good reproducibility, better selectivity, and stability. [ABSTRACT FROM AUTHOR]

Non-woven needle-punched material with silver nanoparticles was obtained from the waste of natural silk cocooning process. Silver nanoparticles were synthesized by chemical reduction from an ammonia solution of silver nitrate. It is shown that the treatment of silk material with a solution of 1-butyl-3-methylimidazolium chloride affects the amorphous-crystalline state of the fiber, its sorption properties and the resistance of silver nanoparticles on the fiber to wet treatments. [ABSTRACT FROM AUTHOR]

While temporal considerations are of prime importance for chemical reactions, as well as for molecular stability, most chemical concepts (outside of the field of chemical kinetics) are not explicitly formulated on a diachronic basis (Earley in Found Chem 14:235, 2012). It will be argued here that a formulation explicitly incorporating temporal and epistemological considerations enables us to treat chemical reactions and chemical substances on ontologically equivalent terms, instead of assigning a more fundamental status to the latter. After all, in collision theory, a chemical substance is just a collision complex (a "resonance") that takes too long. How long qualifies as "too long", and "too long" in relation to what, are crucial questions that distinguish chemical substances from chemical reactions, and reversible reactions from irreversible ones, thereby introducing anthropocentric considerations into these distinctions. Too long for a lab chemist is very different from too long for an astrochemist studying chemical reactions between chemical substances in inter-stellar space on cosmological timescales. Examining several physical and chemical properties on the basis of which chemical substances are distinguished from one another, the role of temporal and anthropocentric considerations in defining molecular properties is emphasized. I conclude with some observations on the much-debated reduction of chemistry to other disciplines, arguing that such reduction depends on our aesthetic choices as to what kinds of observations demand explanation, and what kinds of explanation are acceptable. [ABSTRACT FROM AUTHOR]

All suggested notions of reduction of two scientific theories are critically reviewed and analyzed. In particular those applied to the case of the alleged reduction of Chemistry to Quantum mechanics are examined. Since it is recognized that the weakness of this field of research is the lack of a definition of a scientific theory, it is suggested that a scientific theory is characterized by two choices regarding two dichotomies, that is, the kind of mathematics and the kind of logic. According to this view a reduction is only possible between two theories in which the same choices are shared. As a consequence, only one case of reduction in the history of physics is recognized: physical optics to electromagnetism, a case that is commonly accepted. The other cases of claimed reductions are recognized as impossible, owing to the different choices of the two theories at issue and hence the radical variations in meaning of their shared basic notions. In particular, the claimed reduction of Chemistry to Quantum mechanics is disproved in detail. [ABSTRACT FROM AUTHOR]

In this study, suitability of xylano-pectinolytic enzymes in pulping of wheat straw has been explored. The suitable biopulping conditions were optimized, with xylanase dose of 400 and pectinase dose of 120 IU/g wheat straw, 1:10 (g/ml) material to liquid ratio, 55 °C temperature, 3 h treatment time, 0.75% Tween 80 and pH 8.5. Enzymatic pretreatment efficiently increased the pulpability of wheat straw, generated pulp with higher yield, lower kappa number (15.67%) and rejections (59.65%) in comparison with chemical pulp. The brightness of pretreated wheat straw pulp with enzyme was 16.04% higher than that of the non-enzyme treated wheat straw pulp. The biopulping resulted in 12% reduction of pulping chemicals along with more residual alkali content, in order to achieve similar optical and chemical properties as obtained by 100% chemically treated pulp. Physical properties of pulp also improved after enzymatic pretreatment, increasing burst index (26.50%), tear index (18.22%) and breaking length (5.56%). The enzyme plus chemical (88% pulping chemicals) treated pulp showed improvement in brightness and whiteness, with reduction in yellowness at all bleaching stages. In comparison with chemically bleached pulp, biopulp with reduced alkali dose (88%) had higher breaking length (6.63%), double fold number (51.28%), tear index (2.83%), burst index (24.31%), along with increased viscosity (6.12%) and Gurley porosity (27.50%). These results clearly suggest that biopulping of wheat straw with xylano-pectinolytic enzymes can reduce chemical loading during soda-anthraquinone pulping and also improve the quality of paper. This is the first report demonstrating the biopulping of wheat straw using crude xylano-pectinolytic enzymes. [ABSTRACT FROM AUTHOR]

Methods for the synthesis of polymer hydrogel–metal metamaterials based on polyvinyl alcohol and reduced Cu, Ag, Co, and Fe (or magnetite Fe3O4) particles, including the stage of chemical or thermal reduction or chemical precipitation were proposed. The effect of the synthesis conditions on the size of metal or oxide particles and the regularity of particle distribution in the polymer was studied. The samples of composite materials synthesized under different conditions were characterized by nondestructive X-ray fluorescence and X-ray diffraction methods. An XRD study revealed that after the thermal reduction of Cu, Co, and Fe, the composite contained a significant amount of metal oxides. The optimum conditions for the synthesis of polyvinyl alcohol–magnetite metamaterials were found. [ABSTRACT FROM AUTHOR]

Silk fibers served as a matrix for the reduction of nanoparticles from a silver salt solution. A mathematical model describing the dependence of the total content of reduced silver on a fiber Y on the input parameters X1, X2, X3, X4 (silver concentration in the treatment solution, concentration of reducing agent, temperature and duration of the reduction process, respectively) is constructed. A chemically substantiated nonlinear regression model and a two-layer perceptron are proposed, which make it possible to obtain mathematical expressions for the dependence of the silver content on silk fibers on the input parameters. Both models adequately reflect the experimental data – the error of the regression model is 0.16, the error of the two-layer perceptron is 0.14. [ABSTRACT FROM AUTHOR]

Abstract: Alumina catalysts modified by platinum and nickel nanoparticles were prepared by chemical reduction and microwave stimulated techniques, and their relationship to electrical properties was studied. The structural and textural properties of such nanocatalysts were examined by XRD, DSC-TGA, N2 physisorption and TEM. The electrical properties of nanoparticle catalysts as functions of the increase of metal concentration are discussed. The electrical measurements were performed in the frequency domain. Three mechanisms are suggested for the electrical behaviour of all systems. The increment observed in conductivity with extra amounts of metal may be due to the expansion in the movement ability of uncontrolled transporters that disperse in the pores of the material. Upon arrival at the electrodes, these transporters evacuate their charge and, accordingly, increase the dispersion impedance. The results show high thermal stability up to 1000 °C. The isotherms obtained display almost the same behaviour for samples prepared by both the microwave and the chemical method. This may be linked to high-dispersion particles and their nanoscale metal concentration. The XRD results exhibit small diffraction line characteristics. [ABSTRACT FROM AUTHOR]

Aromatic amine modified 3D porous graphene aerogel was prepared through chemical reduction and self-assembly of graphene oxide sheets in one step by using diaminodiphenylmethane (DDM) as a reducing agent, modifying agent, and curing agent. Subsequently, the DDM-modified graphene aerogel (DGA) was fully infiltrated with epoxy resin to obtain the DGA/epoxy composites. The abundant amine groups derived from DDM on the DGA can react with epoxy resin to strengthen the interfacial interaction, further promoted the curing behaviors by significantly lowering the reaction activation energy. The reinforcement of interfacial interaction and well-interconnected frameworks enhanced the effective transfer of stress and electrons in the resulting composites. Thus, the resulting DGA/epoxy composites exhibited excellent compressive properties and high electrical conductivity. This study presented a facile technique for preparing porous graphene aerogel, which simultaneously improved the electrical conductivity and mechanical properties of epoxy composites, and overcame the issues of dispersion and interfacial interaction of traditional nanofillers. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate the activation of commercial chemical cellulose pulps towards chemical modification by a pre-treatment step with tetrabutylphosphonium acetate ([P4444][OAc]). A heterogeneous (non-dissolving) pre-treatment was applied allowing for a significant reduction in crystallinity, without concomitant formation of the thermodynamically stable cellulose II. An increase in chemical reactivity was demonstrated using two model reactions; (1) acetylation (organic swelling conditions), where high degrees of substitution (DS) were obtained without the need for a catalyst, and (2) 4-acetamido-TEMPO oxidation (aqueous swelling conditions), where significant degrees of oxidation (DO) were obtained, beyond those for the untreated pulps. In both tests a notable improvement in cellulose reactivity was observed. Regioselectivity of acetylation was assessed using 2D NMR for one low and one high DS sample. The low DS showed a small degree of acetylation of the 6-OH, whereas, the high DS from the pre-treated sample showed mainly mixtures of triacetate and diacetates. Important mechanistic information is attained for future development of aqueous and organic-based reactions involving this ionic liquid pre-treatment. [ABSTRACT FROM AUTHOR]

Complicated and strict protocols are followed to tune the size of gold nanoparticles (GNPs) in chemical synthesis methods. In this study, we address the polarity of solvents as a tool for tailoring the size of GNPs in the chemical reduction method. The effects of varying polarity index of the reaction medium on synthesizing gold nanoparticles by chemical reduction method have been investigated. Ethanol as a polar solvent, ethanol–water mixture as reaction medium, L-ascorbic acid as reducing agent, and polyvinylpyrrolidone as stabilizer were used to synthesize GNPs. The polarity index of the reaction medium was adjusted by changing the volume ratio of ethanol to water. UV–Vis, dynamic light scattering (DLS), and transmission electron microscopy (TEM) characterizations reveal that the growth of nanoparticles was gradually increased (~ 22 to 219 nm hydrodynamic diameter) with decreasing value of polarity index of the reaction medium (~ 8.2 to 5.2). Furthermore, the high polarity index of the reaction medium produced smaller and spherical nanoparticles, whereas lower polarity index of reaction medium results in bigger size of GNPs with different shapes. These results imply that the mechanistic of the growth, assembly, and aggregation phenomena of ligand or stabilizer-capped GNPs strongly rely on the polarity of solvent molecules. Using the proposed methodology, wide size range of GNPs with different morphology sizes can be synthesized by simply modulating the volume percentage of organic solvent in the reaction medium. [ABSTRACT FROM AUTHOR]

Purpose: A 6-year (2011–2016) field experiment was performed to explore the effects of partial substitution of chemical fertilizer by green manure on rice yield, sustainability yield index, and the building-up of different fractions of soil organic carbon, soil nitrogen, and phosphorus. Materials and methods: The experiment included no fertilization (NF), chemical fertilizer only (CF100), and Chinese milk vetch (Astragalus sinicus L.) incorporation with 80%, 60%, 40%, 20%, and 0% of total N, P, and K supplied from chemical fertilizer (MVCF80, MVCF60, MVCF40, MVCF20, and MVCF0, respectively) treatments. The soil organic carbon fractions, soil nitrogen, and phosphorus fraction contents were measured over 6 years. Results and discussion: In comparison with CF100 treatment, the MVCF80, MVCF60, and MVCF40 treatments significantly increased rice yield between 2013 and 2016, thus improving sustainability yield index. The soil organic carbon fractions increased 15–58%, 16–61%, 14–50%, and 12–33% in the MVCF80, MVCF60, MVCF40, and MVCF20 treatments, respectively, compared with the CF100 treatment (p < 0.05). The easily oxidizable nitrogen, acid hydrolysable pool II nitrogen, total nitrogen, NaOH extractable phosphorus, HCl extractable phosphorus, and total phosphorus contents in the MVCF40 treatment were 17%, 28%, 9%, 12%, 15%, and 8% higher than those in the CF100 treatment (p < 0.05). The MVCF60 and MVCF80 treatments further increased the contents of these nitrogen and phosphorus fractions compared with the CF100 treatment. Stepwise multiple linear regression analysis showed that the average yield was positively influenced by the contents of total phosphorus, easily oxidizable nitrogen, and dissolved organic nitrogen, and that the sustainability yield index was positively influenced by the contents of easily oxidizable carbon and total organic carbon. Conclusions: Chinese milk vetch incorporation with a 20–40% reduction in chemical fertilizer inputs may be a potential fertilization practice for improving rice productivity and sustainability. [ABSTRACT FROM AUTHOR]

Renewable energy resources play a valuable role in the global increase of energy demand. The research was performed to enhance the performance of plasmonic dye-sensitized solar cells (PDSSCs) by harvesting the maximum sunlight. In this context, the TiO2 nanoparticles for simple DSSCs and the Cu/rGO/TiO2 nanocomposites for PDSSCs were synthesized using the Sol–Gel and chemical reduction method. Authors demonstrated the utilization of synthesized Cu/rGO/TiO2 nanocomposite-based photoanode to fabricate the plasmonic dye-sensitized solar cells (PDSSCs). SEM, EDX, XRD, and UV/Vis techniques were employed to analyze the surface morphology, elemental composition, crystal structure, and absorbance spectra, respectively. Furthermore, IV measurements were performed on the fabricated devices, and it was observed that the Cu/rGO/TiO2 nanocomposite presented an enhanced efficiency of 5.14% in PDSSCs, which is more than that of the DSSCs-based on pure TiO2 nanoparticles. As an enhanced efficiency could be achieved by high optical absorption and electron injection rate, the PDSSCs with Cu/rGO/TiO2 nanocomposite have an enhanced efficiency due to the surface plasmonic resonance. An improved IPCE of 59.79% was also achieved in Cu/rGO/TiO2 nanocomposite-based photoanode, which might be due to the higher surface area of the photoanode. [ABSTRACT FROM AUTHOR]

The processes of hydrogenation of furan and its derivatives (2-methylfuran, furfuryl alcohol, and furfural) in plug-flow type reactor under atmospheric hydrogen pressure at 20–220°С in the presence of supported nickel nanoparticles prepared via chemical reduction have been investigated. It has been found that nickel nanoparticles supported on magnesium oxide surface are the most reactive and stable under the considered conditions. This catalyst allows the corresponding hydrogenation products with 100% yield and complete conversion of the substrate. [ABSTRACT FROM AUTHOR]

The study of Pt(IV) antitumor prodrugs able to circumvent some drawbacks of the conventional Pt(II) chemotherapeutics is the focus of a lot of attention. This paper reports a thorough study based on experimental methods (reduction kinetics, electrochemistry, tandem mass spectrometry and IR ion spectroscopy) and quantum–mechanical DFT calculations on the reduction mechanism of cisplatin-based Pt(IV) derivatives having two hydroxido (1), one hydroxido and one acetato (2), or two acetato ligands (3) in axial position. The biological reductants glutathione and ascorbic acid were taken into consideration. The presence of a hydroxido ligand resulted to play an important role in the chemical reduction with ascorbic acid, as verified by 15N-NMR kinetic analysis using 15N-enriched complexes. The reactivity trend (1 > 2 > 3) does not reflect the respective reduction peak potentials (1 < 2 < 3), an inverse relationship already documented in similar systems. Turning to a simplified environment, the Pt(IV) complexes associated with a single reductant molecule (corresponding to the encounter complex occurring along the reaction coordinate in bimolecular reactions in solution) were characterized by IR ion spectroscopy and sampled for their reactivity under collision-induced dissociation (CID) conditions. The complexes display a comparable reduction reactivity ordering as that observed in solution. DFT calculations of the free energy pathways for the observed fragmentation reactions provide theoretical support for the CID patterns and the mechanistic hypotheses on the reduction process are corroborated by the observed reaction paths. The bulk of these data offers a clue of the intricate pathways occurring in solution. Graphic abstract [ABSTRACT FROM AUTHOR]

An asymmetric synthesis of 14-methyl-1-octadecene, the sex pheromone of the peach leafminer moth has been achieved. Based on the asymmetric methylation of chiral (S)-4-benzyloxazolidin-2-one, the carbon chain of the target molecule was assembled through a C1+C10+C4+C3 procedure. The γ-lactone was transformed into 4-(benzyloxy)butanoic acid and then, with the induction of Evan's template, a chiral methyl group was introduced to the position of the carboxylic group in 97% de. After reduction and a couple of chemical operations, the designed key intermediate A1 was obtained. The synthesis of another moiety was started from decane-1,10-diol which was selectively protected and oxidized. The long carbon chain was installed according to a Wittig protocol. After deprotection, oxidization, and methylenation, the target molecule was synthesized in 7 linear steps with an overall yield of 30.3%. [ABSTRACT FROM AUTHOR]

In this study, the reduction of three silicomanganese charges prepared from industrial raw materials was investigated under isothermal conditions between 1783 K and 1933 K (1510 °C and 1660 °C). The main reactions examined are MnO and SiO2 slag reduction following the chemical equations MnO(l) + C = Mn(l) + CO(g) and SiO2(l) + 2C = Si(l) + 2CO(g). The charges containing a combination of Assmang ore, Comilog ore, high-carbon FeMn slag with quartz were pre-reduced, melted to a MnO-SiO2-Al2O3-MgO-CaO quinary slag and reduced in presence of coke using a thermogravimetric set-up. The reduced slags were further analyzed using electro-probe micro-analysis to evaluate their MnO and SiO2 contents. It is observed that the reduction pathway occurred in two stages: a first slow and stable stage was followed by a rapid rate increase during the second stage. The rate change shift between the two stages was found to depend on the initial charge's composition and the extent of reduction, but not on the temperature. Using an established rate equation, the kinetics of MnO and SiO2 reduction were modeled over the first stage. A good fit was obtained between simulated and experimental data. [ABSTRACT FROM AUTHOR]

Due to the high toxicity of effluents radiating from tannery industries, there is a need for effluent treatment so as to limit its dangerous impacts on the environment. Fabricating responsive membranes is gaining significant interest in wastewater treatment applications. This study investigates the preparation, characterization, permeation, and antifouling properties of the keratin-polysulfone blend membranes. Keratin, a bioinspired material, is used as the responsive element along with the polysulfone matrix, which together acts as the responsive membranes for efficient filtration. Keratin was extracted from the goat hair, a tannery waste, through ball milling—an ecological, cost-effective, and time-consuming method. Keratin-polysulfone was blended in the ratio 95:5 (v/v) in their respective solvents to prepare nanofiltration membranes. The morphology of the membranes shows the random arrangement of fibers with the interstitial spaces. Contact angle measurements reveal that the keratin-polysulfone blend membranes are partially hydrophilic, which in turn resulted in good antifouling properties. Improved porosity of the fabricated membranes enabled good absorption capacity, and enhanced mechanical properties are an added advantage for the fabricated membranes. Since the membrane showed enhanced filtration property, the post-tanning effluents from the leather industry have been treated by the keratin-polysulfone fabricated membranes. The treated effluent showed a maximum percentage reduction in chemical oxygen demand (COD) and biological oxygen demand (BOD) concentrations of about 53% and 66%, respectively. The dye removal efficiency of the fabricated membrane is reported to be 76%. Thus, filtration efficiency has been established paving a way for treating effluents in an efficient way. [ABSTRACT FROM AUTHOR]

Applications of nanomaterials has recently been of keen interest to researchers. This fascinating drive ensued due to their unique properties such as optical, magnetic, ease of synthesis, large surface area, and tunable surface chemistry and functionalization that are remarkably different from that of the bulk material. In this work, silver nanoparticles were synthesized and characterized using UV–Vis spectroscopy and scanning electron microscopy. The UV–Vis spectra obtained showed absorption peak at 406 nm wavelength and scanning electron microscope reveals an image of size, 20 nm. The efficiency of our nanomaterial was first tested using standard solutions of cobalt and lead. A bathochromic shift in the absorption wavelength from 406 to 445 nm and from 406 to 458 nm for Cobalt(II) and Lead(II), respectively, indicates an adsorption has taken place. Adsorption characteristics of the nanoparticles evaluated at various incubation periods indicates a percent reduction in cobalt(II) from 33.13 to 53.34% and 79.9–92.92% for lead(II) from day 1–14. This indicates high removal efficiency for lead(II) than cobalt(II) in the proof of concept experiment. The results obtained further reveal that metal ion removal from complexes using silver nanoparticles is time-dependent. The effectiveness of our nanomaterial toward metal ion removal from groundwater was tested using inductively coupled plasma optical emission spectroscopy. The results obtained reveal removal efficiencies of 24% for cobalt and 77% for lead. It is important to note that metal ion concentrations reduced as the incubation periods increased. This is in line with the proof of concept experiment using complex solutions of cobalt and lead. Notably, the percent removal of cobalt was quite low compared to proof of concept experiment. These observations suggest a further research into understanding the adsorption characteristics of metal ions to the surface of nanomaterials in aqueous media. [ABSTRACT FROM AUTHOR]

Five Au complexes are evaluated for the reduction reaction of CO2 via cyclic voltammetry and in a photocatalytic system. Electrochemically, the complexes were all evaluated for pre-association with CO2 prior to electrochemical reduction and for thermodynamic favorability for CO2 reduction in photocatalytic systems. The complexes were evaluated in photocatalytic reactions using an Ir-based photosensitizer and a sacrificial electron donor for the conversion of CO2 to CO. Au-complex counterion effects on the photocatalytic reaction were analyzed by varying weakly coordinating counterions with significant performance changes noted. At low Au-complex concentrations, a high TON value of 700 was observed. [ABSTRACT FROM AUTHOR]

Photodegradation of organic pollutants is considered to be the most suitable and cheaper techniques to counter the contamination issues. Metal nanoparticles are considered to be the most effective heterogenous photocatalysts for the photodegradation of organic pollutants. Besides, CuO oxide nanoparticles are well-known photocatalysts for photocatalytically degrading organic pollutants. Herein, we reported the synthesis of pure copper oxide nanoparticles (CuO NPs) and nanoclay-supported copper oxide nanoparticles (CuO/NC NPs) by facile chemical reduction technique for swift photodegradation of organic dye. The X-ray diffractogram (XRD) has demonstrated a typical monoclinic phase of CuO NPs. The morphological features via scanning electronic microscopy (FESEM) showed agglomerated morphology of CuO NPs with 372.57 ± 1.76 nm average particle size. The micrographs also revealed the homogenous dispersion of CuO NPs over NC surface in CuO/NC nanocomposite. A polydispersity index (PDI) of 0.39 presented slight variation in the particle size of CuO NPs, which is also supported by the results obtained from atomic force microscopy (AFM), FESEM and transmission electron microscopy (TEM). CuO/NC NPs demonstrated outstanding methyl orange degradation over a very short period of time under simulated light. Using CuO/NC NPs, about 97.18% and 95.96% dye degradations were achieved in merely 4 min, under UV and visible light, respectively. The excellent photodegradation efficacy of CuO/NC NPs can be attributed to the homogenous distribution of CuO NPs, which facilitates the generation of photoexcitons (electrons and holes), enhances charge transfer and minimizes the charge recombination. The NC induced the required photostability by providing sufficient space for NPs distribution. [ABSTRACT FROM AUTHOR]

Magnesium oxide (MgO)-supported nanocatalysts are a highly insulating crystalline solid with a sodium chloride crystal structure and excellent properties including chemical inertness, high temperature stability and high thermal conductivity. Here, a ternary alloy catalyst of MgO-supported CoMoB was synthesized by means of a chemical reduction method using ethylene glycol solution. The prepared CoMoB/MgO catalysts were characterized using x-ray diffraction, scanning electron microscopy (SEM/EDX) and Fourier transform infrared spectroscopic analysis. The CoMoB/MgO nanocomposite served as the enabling platform for a range of applications including hydrogen production catalyst and hydrogen peroxide (H2O2) determination. It also showed a high hydrogen production rate (1000 mLgcat−1 min−1) and low activation energy (68.319 kJ mol−1) for the hydrolysis of ammonia borane. Additionally, the electro-oxidation performance of the CoMoB/MgO for H2O2 detection was studied by cyclic voltammetry and chronoamperometry. The CoMoB/MgO sensor demonstrated a wide linear range up to 10 mM with a detection limit of 3.3 μM. [ABSTRACT FROM AUTHOR]

Polyvinylpyrrolidone (PVP)/CuO composites were synthesized using polymerization method for humidity sensing. The CuO nanosheets for composite were prepared by chemical reduction method. It was found that the PVP/CuO nanocomposite has compact structure while PVP was porous in nature. Humidity sensors using PVP, CuO, and PVP/CuO nanocomposite were fabricated by simple-drop casting method. Interdigitated copper electrodes with 50 μm gap were used for the casting of substrate in dust-free environment. The comparative study was performed at a constant temperature of 300 K with different frequencies using LCR meter. Resistance of the sensors was decreased to zero as the humidity concentration increased from 25 to 95% RH in the sensing assembly. An appreciable increase of 58.5–4370 nF (sensitivity 71,660%/%RH) was observed in capacitance with the increase of humidity level from 25 to 95% RH at 0.1 kHz frequency. A small hysteresis value of 6.7%, 1.8%, and 2.1% were observed for PVP, CuO, and PVP/CuO nanocomposite. When compared with PVP and CuO, an efficient response was recorded for PVP/CuO nanocomposite toward humidity sensing. [ABSTRACT FROM AUTHOR]

The Fischer-Tropsch (F-T) process for production of fuels is entrenched in several countries' approach to meeting energy demands. However, the clean water deficit associated with the down-stream processes has made it necessary to explore bioremediation methods to ameliorate the consequences of its use. In this study, a consortium of bacteria was utilized for determination of biodegradation and removal rates, based on reduction in chemical oxygen demand of a mixture of acetone, propionic acid and hexanoic acid (APH) (all components of F-T wastewater), at an organic loading of 5 and 9.53 g CODL−1. The individual degradation efficiencies of the F-T components were determined using a gas chromatograph. Further, the bacterial consortia responsible for the degradation of the mixture of APH were determined using metagenomics data derived from next-generation sequencing. The overall chemical oxygen demand removal was found to be 88.8% and 82.3% at organic loading of 5 and 9.53 g CODL−1, respectively. The optimal degradation efficiency of acetone, propionic acid and hexanoic acid over a period of 10 days was found to be 100%, 85% and 75.8%, respectively. The primary microbial communities presumed to be responsible for APH degradation by phyla classification across all samples were found to be Proteobacteria (55–92%), Actinobacteria (5–33%) and Firmicutes (0.08–9%). Overall, the study has demonstrated the importance of aerobic consortia interactions in the degradation of components of the F-T wastewater. [ABSTRACT FROM AUTHOR]

The influence of cold rolling on the mechanical characteristics of polypropylene saturated with particles consisting of three to five monolayers of graphene (the degree of filling of 0.2–3.5 wt %) is studied. The nanocomposites are obtained by in situ filling, i.e., synthesis of the polypropylene matrix on the particles, thus allowing more uniform distribution of the filler throughout the bulk of the matrices. The filling makes it possible to increase the Young modulus of the material. A certain fraction of particles assemble to form agglomerates, and another fraction of particles are uniformly distributed in the matrix. The agglomerates already lead to the embrittlement of unrolled polypropylene at a degree of filling of 0.2 wt %. Cold rolling suppresses the brittle behavior of the composite irrespective of the method of reduction of the particles of graphite oxide (chemical or thermal reduction). As a result of preliminary cold rolling, the elongation at break and strength of filled polypropylene sharply increase (depending on the degree of cold rolling and concentration of the filler, the elongation at break increases 50- to 100-fold, and the strength increases 1.5- to 2.0-fold). In the initial material, the agglomerates initiate the appearance of local fluidity microzones where rhombohedral microcracks fracturing the composite are conceived. No microzones appear at a degree of cold rolling Λ = 1.25, while no neck is observed either at Λ = 1.9. After cold rolling to a value of Λ = 1.25, pore formation upon further stretching disappears. [ABSTRACT FROM AUTHOR]

Silver/titania (Ag/TiO2) nanocomposites, synthesized through a simple one-step chemical reduction method, are used for electrochemical sensing of hydrogen peroxide (H2O2). The images of transmission electron microscopic (TEM) demonstrate a well dispersion of Ag nanoparticles (NPs) with a particle size range of approximately 3 nm on the TiO2 surface, which makes the sensor based on Ag/TiO2 exhibit an excellent performance toward H2O2. The AgNPs presented in the nanocomposite exhibit electrocatalytic reduction of H2O2 and the limit of detection (LOD) is found to be 1.23 µM. Density functional theory (DFT) calculation studies reveal that H2O2 could be easily adsorbed onto Ag rather than TiO2 surface of Ag/TiO2 via a partial electron transfer from Ag to H2O2. The nanocomposite-modified electrode has also excellent selectivity toward the detection of H2O2 over the interferents even when the interferents have a 100 times higher concentration than H2O2. [ABSTRACT FROM AUTHOR]

The symbiotic Epichloë festucae var. lolii endophyte produces alkaloids which can provide its host grass, perennial ryegrass (Lolium perenne L), with a selective advantage in both natural and agricultural managed ecosystems. This study focuses on understanding the alkaloid concentrations that occur in endophyte-infected perennial ryegrass during the early establishment phase. In a glasshouse experiment fungal alkaloid concentrations (peramine, lolitrem B, ergovaline, and epoxy-janthitrems) were measured in perennial ryegrass seedlings infected with E. festucae var. lolii proprietary strains AR1, AR37, NEA2, and NZ common toxic for 69 days after sowing. The endophyte becomes metabolically active, starting alkaloid production, as early as 6 days after sowing. Alkaloid concentrations peaked in 8- to 10- day-old seedlings due to a seedling growth slowdown. This study provides data showing that the loss of insect protection in endophyte-infected seedlings is linked to a reduction in chemical defence after seed-stored, maternally synthesised alkaloids are diluted by seedling dry matter accumulation. [ABSTRACT FROM AUTHOR]

High-performance Nd2Fe14B magnets have been widely required in various fields recently due to the lightweight and miniaturization of devices. In this work, we synthesize Nd2Fe14B nanostructures with tunable magnetic properties through surfactant-assisted high energy ball milling (SAHEBM) process, achieving prominently enhanced coercivity by forming non-magnetic layers as grain boundary phase. When the reduction annealing process was carried out as pellet with Ca, the coercivity increased from 0.8 kOe to ver 3 kOe as Nd2Fe14B powder, which is proved to be the contribution of the chemical diffusion of Nd elements and the formation f Nd-rich layer as magnetic insulating medium. In addition, two-dimensional graphene oxide (GO) was employed to build extra grain boundary, by which the coercivity of the core@dual-shell structure can achieve up to 8 kOe, tenfold of the original sample. The intrinsic mechanism indicated that the Nd-diffusion induced Nd-rich phase along with the reduced GO in the system could form non-magnetic layer as grain boundary and magnetically isolate the adjacent grains, significantly enhancing the exchange coupling effect. This work markedly opens up an effective approach for the chemical preparation of high-performance Nd2Fe14B nanostructured magnets, especially after post treatment, and gives an insight on the interactions at nanoscale. [ABSTRACT FROM AUTHOR]

The use of renewable materials and cleaner production is currently the target of the automotive industry to reduce the use-phase environmental impacts of vehicles. Renewable lightweight materials are used to replace conventional materials to produce lightweight automotive parts, leading to reduced fuel consumption, which contributes toward meeting the industry's environmental impact target. In this study, we compared the life cycle of a conventional composite to that of a biocomposite for automotive applications using the standard set by the International Standards Organization (ISO 2006). The conventional one is talc-reinforced polypropylene composite (talc–PP) at a 70% PP to 30% talc weight ratio. The biocomposite is Miscanthus biochar-reinforced polypropylene composite (MB–PP) at a 70% PP to 30% MB. The functional unit is 982 cm3 of composite used for a certain vehicle part (i.e., an automotive component). The environmental impacts are determined using the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI, v2.1). The system boundary includes material extraction to the disposal stage of the composites. The results revealed that MB–PP composite had the least impact for all categories than talc–PP composite and appeared to be a favorable option for automotive parts from an environmental perspective. This study indicates that MB-PP can reduce about 25% environmental impacts of the life of composite if it replaces the talc–PP composite. The MB–PP composite emerged as a promising option than talc–PP composite and has environmentally benign green credentials for automotive parts application. [ABSTRACT FROM AUTHOR]

The recently reported 9–15 K superconductivity in Nd0.8Sr0.2NiO2/SrTiO3 heterostructures that were fabricated by a soft-chemical topotactic reduction approach based on precursor Nd0.8Sr0.2NiO3 thin films deposited on SrTiO3 substrates, has excited an immediate surge of research interest. To explore an alternative physical path instead of chemical reduction to realizing superconductivity in this compound, using pulsed laser deposition, we systematically fabricated 63 Nd0.8Sr0.2NiOx (NSNO) thin films at a wide range of oxygen partial pressures on various oxide substrates. Transport measurements did not find any signature of superconductivity in all the 63 thin-film samples. With the oxygen content reducing in the NSNO films by lowering the deposition oxygen pressure, the NSNO films are getting more resistive and finally become insulating. Furthermore, we tried to cap a 20-nm-thick amorphous LaAlO3 layer on a Nd0.8Sr0.2NiO3 thin film deposited at a high oxygen pressure of 20 Pa to create oxygen vacancies on its surface and did not succeed in obtaining higher conductivity either. Our experimental results together with the recent report on the absence of superconductivity in synthesized bulk Nd0.8Sr0.2NiO2 crystals suggest that the chemical reduction approach could be unique for yielding superconductivity in NSNO/SrTiO3 heterostructures. However, SrTiO3 substrates could be reduced to generate oxygen vacancies during the chemical reduction process as well, which may thus partially contribute to conductivity. [ABSTRACT FROM AUTHOR]

In the present work, Chitosan/bentonite, Chitosan/Ag-bentonite and Chitosan/AgNPs-bentonite composite materials were prepared and shaped in form of beads, and characterized using several methods. After that, their thermal stability, swelling properties and antibacterial and antifungal activity were evaluated. In the case of Chitosan/AgNPs-bentonite, the XRD analysis confirms the partial intercalation of chitosan in the interlayer of bentonite and the formation of silver nanoparticles, AgNPs, with an average diameter between 10 and 25 nm. The latter is confirmed by UV–Visible diffuse reflectance spectroscopy by the apparition of the large absorption band at 442 nm. For all prepared materials, the FTIR analysis shows the presence of strong interaction between chitosan reactive groups and bentonite interlayer materials. This result is confirmed by thermal analysis where it is observed that these composite materials exhibit a higher thermal stability than the biopolymer alone. The composite materials present also a very good swelling capacity. Indeed, the swelling rate carried out in water media at pH 7 and a temperature of 30 °C is 160% higher than that of the corresponding dried material. Otherwise, Chitosan/AgNPs-bentonite sample displays a very high antibacteriaPseudomonas aeruginosal activity against pathogen bacteria strains such as Staphylococcus aureus ATCC 25923 and ATCC 27853. This activity is less important for S. aureus ATCC 43300 and no activity is observed for Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Since the starting chitosan and bentonite materials showed no antibacterial or antifungal activity, the antibacterial activity of Chitosan/AgNPs-bentonite sample is attributed to loaded AgNPs species. [ABSTRACT FROM AUTHOR]

The atmospheres of the four giant planets of our Solar System share a common and well-observed characteristic: they each display patterns of planetary banding, with regions of different temperatures, composition, aerosol properties and dynamics separated by strong meridional and vertical gradients in the zonal (i.e., east-west) winds. Remote sensing observations, from both visiting spacecraft and Earth-based astronomical facilities, have revealed the significant variation in environmental conditions from one band to the next. On Jupiter, the reflective white bands of low temperatures, elevated aerosol opacities, and enhancements of quasi-conserved chemical tracers are referred to as 'zones.' Conversely, the darker bands of warmer temperatures, depleted aerosols, and reductions of chemical tracers are known as 'belts.' On Saturn, we define cyclonic belts and anticyclonic zones via their temperature and wind characteristics, although their relation to Saturn's albedo is not as clear as on Jupiter. On distant Uranus and Neptune, the exact relationships between the banded albedo contrasts and the environmental properties is a topic of active study. This review is an attempt to reconcile the observed properties of belts and zones with (i) the meridional overturning inferred from the convergence of eddy angular momentum into the eastward zonal jets at the cloud level on Jupiter and Saturn and the prevalence of moist convective activity in belts; and (ii) the opposing meridional motions inferred from the upper tropospheric temperature structure, which implies decay and dissipation of the zonal jets with altitude above the clouds. These two scenarios suggest meridional circulations in opposing directions, the former suggesting upwelling in belts, the latter suggesting upwelling in zones. Numerical simulations successfully reproduce the former, whereas there is a wealth of observational evidence in support of the latter. This presents an unresolved paradox for our current understanding of the banded structure of giant planet atmospheres, that could be addressed via a multi-tiered vertical structure of "stacked circulation cells," with a natural transition from zonal jet pumping to dissipation as we move from the convectively-unstable mid-troposphere into the stably-stratified upper troposphere. [ABSTRACT FROM AUTHOR]

An electrochemical aptasensor for thrombin is introduced that makes use of a nanohybrid composed of silver nanoparticles and graphite-like carbon nitride (Ag-g-C3N4). The material has a large surface and good biocompatibility. AgNPs are modified directly on the surface of g-C3N4 via chemical reduction. A glass carbon electrode (GCE) modified with Ag-g-C3N4 can immobilize a large number of amino-terminated thrombin binding aptamers (NH2-TBA) through strong Ag-N bonds. The electrochemical impedance signal of the aptasensor increases in the presence of thrombin. Under the optimal conditions and by using [Fe(CN)6]3−/4- as an electrochemical probe, the aptasensor shows a wide linear range of 100 fM – 20 nM with a lower detection limit of 38 fM. The method was applied to the determination of thrombin in spiked human plasma and the recoveries fluctuated from 97.2% to 103%. [ABSTRACT FROM AUTHOR]