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In this study, intermittent creep‐fatigue tests were applied on Ni‐based Alloy 617 and Alloy 625. Scanning electron microscope (SEM) observation and electron back‐scatter diffraction (EBSD) analysis were employed to the evaluation of the degradation of the crystallinity under the creep‐fatigue loads. It was found that the initial damage under creep‐fatigue load basically appeared as intergranular cracks. In addition, the lifetimes of Alloy 625 samples fluctuated significantly due to the growth of NbC precipitates. The initial damage of these two alloys was dominated by the growth and accumulation of dislocations and vacancies around the interface that consisted of large lattice mismatch. Local atomic diffusion was activated when the summation of the nominal stress and local stress caused by the large lattice mismatch exceeded a critical value. The stress‐induced acceleration of the degradation of the crystallinity of the alloys was analyzed by applying the modified Arrhenius equation. Instead of the most popular inversion methods according to the final failure mode, the quantitative description in life prediction was developed based on the dynamic progress for acceleration mechanism of the degradation. It is of importance to perfecting the frontiers of damage mechanics approach. Highlights: The degradation mechanism was obtained by analyzing the damage behavior of two alloys.IQ value was used to characterize the degree of degradation under creep‐fatigue load.The degree of degradation and life assessment was expressed quantitatively. [ABSTRACT FROM AUTHOR]

Metal-Organic Frameworks (MOFs) is widely utilized as photocatalysts in dye photocatalytic degradation. This study successfully synthesized bimetallic MOFs La-Y-PTC by the solvothermal method. The synthesized La-YPTC has a diffractogram pattern with a value of 2θ = 5.69°; 9.57°; 16.8°; 20.05°; 24.8°; 26.15°; 29.77° and 41.93° with a crystal size of 21.45 nm. The La-Y-PTC has symmetric and asymmetric (COO-) at 1591 and 1433 cm-1, La-O and Y-O groups at 596 and 659 cm-1 and a band gap energy of 2.16 eV. Scanning Electron Microscope analysis showed that the morphology of La-Y-PTC is spherical with a particle size of 354.307 nm. La-Y-PTC degrades methylene blue and methyl orange at pH 2 with a degradation efficiency of 69.57% and 93.63%, respectively, under 250 watts of mercury lamp irradiation for 180 min with hydroxyl radical species as a dominant species that play a role in methylene blue and methyl orange degradations. [ABSTRACT FROM AUTHOR]

Zinc oxide has been shown to be a potential photocatalyst under UV light but its catalytic activity is limited under visible light due to its wide bandgap energy and rapid recombination of electrons and holes. Besides the catalytic recovery is a challenging issue because of its dispersion in solution. Previous work has shown that the interaction of gold nanoparticles with ZnO can reduce the band gap energy (Eg) and plasmon resonance (SPR) as well as the formation of the Schottky barrier in Au/ZnO composite can reduce the recombination of electrons and holes. In this study, Au/ZnO/Fe3O4 (AZF) composites were prepared by a simple mixing method using polyvinyl alcohol (PVA) as a binder. As-prepared composites were characterized by Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), UV-Vis Diffuse Reflectance (UV-Vis-DR), and Fourier Transform Infra Red (FT-IR). The catalytic efficiency of as-prepared samples was evaluated through the decomposition of tartrazine (TA), a colorant that is difficult to decompose in wastewater and has harmful effects on human health. The effects of reaction parameters such as the content of PVA, solution pH, and oxidizing agents (O2 and H2O2) on the catalytic efficiency were studied. The AZF at PVA of 0.0125 g showed the highest performance among as-prepared samples. With the presence of 12 mM H2O2 in the catalyst system, the degradation efficiency and reaction rate of TA in composite increased to 81.5% and 0.020 min-1, respectively. At this condition, photocatalysis and Fenton system catalysis occurred together. The catalytic mechanism of Tartrazine (TA) on composite was proposed and the reaction of TA was studied by the first-order kinetic model. [ABSTRACT FROM AUTHOR]

The Smithsonian Institution's National Museum of American History houses the largest remaining collection of inter‐positive composite glass plate images from the production of Eadweard Muybridge's Animal Locomotion series. These photographs, which are approximately 150 years old, exhibit a wide range of degradation phenomena and products, including alteration of the glass plates. Compositions of both the image‐bearing glass plates and support glass panels were obtained through quantitative scanning electron microscope–energy‐dispersive spectrometry. Electron imaging of cross‐sectioned samples of the image‐bearing glass plates reveals a visible sodium‐depleted glass alteration layer. Furthermore, electron imaging shows delamination of the image‐containing gelatin layer and captures evidence that suggests that interfacial stresses between the glass alteration layer and the unaltered glass contribute to the delamination of this layer along with the overlaid gelatin. [ABSTRACT FROM AUTHOR]

The advantages of IR spectroscopy include relatively fast analysis and sensitivity, which facilitate its wide application in the pharmaceutical, chemical and polymer sectors. Thus, IR spectroscopy provides an excellent opportunity to monitor the degradation and concomitant evolution of the molecular structure within a perovskite layer. As is well-known, one of the main limitations preventing the industrialization of perovskite solar cells is the relatively low resistance to various degradation factors. The aim of this work was to study the degradation of the surface of a perovskite thin film CH3NH3PbI3-xClx caused by atmosphere and light. To study the surface of CH3NH3PbI3-xClx, a scanning electron microscope, infrared (IR) spectroscopy and optical absorption were used. It is shown that the degradation of the functional layer of perovskite proceeds differently depending on the acting factor present in the surrounding atmosphere, whilst the chemical bonds are maintained within the perovskite crystal structure under nitrogen. However, when exposed to an ambient atmosphere, an expansion of the NH3+ band is observed, which is accompanied by a shift in the N–H stretching mode toward higher frequencies; this can be explained by the degradation of the perovskite surface due to hydration. This paper shows that the dissociation of H2O molecules under the influence of sunlight can adversely affect the efficiency and stability of the absorbing layer. This work presents an approach to the study of perovskite structural stability with the aim of developing alternative concepts to the fabrication of stable and sustainable perovskite solar cells. [ABSTRACT FROM AUTHOR]

The discoloration of pigments caused by deterioration may significantly alter an artifact's original pattern and design, which could have an impact on its intended meaning. The green pigments containing copper (Cu) and arsenate (As) in paintings are usually recognized as Emerald green or Scheele's green and are also infrequently reported as cornwallite and lavendulan. Recent studies point out that lavendulan may be the degradation product of Emerald green but not a natural mineral. Overall, there are still relatively few cases of current studies on green pigment with Cu and As. The elemental composition and molecular structure of green minerals containing Cu and As are similar, so it is difficult to identify by Raman spectroscopy. The green pigment samples used in this investigation were taken from architectural paintings in the Wenchang palace and traditional Ziweishan dwellings. The composition of the paint samples was investigated comprehensively by Raman spectroscopy, scanning electron microscope observation, micro-X-ray diffraction (μ-XRD), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge spectroscopy (XANES) analysis. From the results of elemental distribution, the pigments mainly contain Cu, As, and Cl. The morphological results illustrated that the particles in these three pigments are rounded and granular, indicating the synthetic pigment is possibly emerald green. The characteristic vibrational peaks of the As–O, Cu–O and Cu–Cl bond were detected by Raman spectroscopy, and infrared spectroscopy found the presence of oxalate salt. The XPS and XANES analysis results show that As valence is + 5. This study found that the green pigment samples are a degradation product of emerald green. The formation of this product is related to the preservation environment. The results of this work will provide information to understand the degradation processes of emerald green and be a reference for the identification of pigments containing Cu and As elements. [ABSTRACT FROM AUTHOR]

To improve the catalytic efficiency and decrease the reaction temperature of wet air oxidation technology, a Cu2O/Al2O3 coating was prepared on the surface of aluminium alloys by anodizing technology, and subsequent heating treatment. Then, the Cu2O/Al2O3 coating and 3 wt.% H2O2 was used to degrade methyl orange. The influence of the coating's microstructure, crystalline component on the degradation rate of the methyl orange was studied. The microstructure of the coating was observed by scanning electron microscope. Results proved that the coating was composed of micropores, and Cu2O was evenly dispersed on the surface and pores in the Al2O3 coating. X-ray diffraction pattern analysis demonstrated Cu2O and Al2O3 characteristic peaks were found after the coating was treated at 300 °C, showing that amorphous Cu2O and Al2O3 were transformed into crystalline oxide. A UV-vis spectrophotometer was used to measure the absorbance of methyl orange, and it was found that the maximum absorption wavelength of methyl orange is 460 nm. At that wavelength, the suitable degradation condition of methyl orange was studied, and results showed that when electrochemical deposition time was 30 min and catalyst dosage was 8 g, the degradation rate of methyl orange could reach 92% at 25 °C for 120 min. Furthermore, when the catalyst was reused 9 times, the degradation rate still reached 75%. Based on the above results, a kinetic equation between the degradation rate of methyl orange and catalyst dosage was derived. The microstructure and crystalline component of the catalyst after different reuse times were characterized, and results showed that the catalytic efficiency of the Cu2O/Al2O3 coating decreased with a decrease in the coating's specific surface area and the ratio of Cu2O in the coating. [ABSTRACT FROM AUTHOR]

Wastewater of industries, which is polluted with different dyes is becoming a severe issue, which should be tackled on priority bases such as to provide an eco-friendly environment. In addition to this, in search of an efficient green synthesized capacitive electrode material, we have synthesized cobalt oxide (Co 3 O 4) nano-materials by employing green chili and sunflower seeds extracts. The as synthesized samples are labeled as Co-P, Co-GC and Co-SF. The successful fabrication of these samples was tested by X-ray diffraction (XRD), scanning electron microscope (SEM), Xray photoelectron spectroscope (XPS). These tests have explored successful fabrication of Co 3 O 4 -based samples comprised on nanoparticles (NPs) in the range of 35–45 nm. Optical properties were studied by UV–vis spectroscope and Co-SF sample has exhibited lowest energy band gap i.e 2.41 eV. Photoluminescence (PL) analysis has explored that Co 3 O 4 NPs prepared by sunflower extracts have offered lowest recombination rate. Among of Co-P, Co-GC and Co-SF photocatalysts, Co-SF has shown excellent photodegradation activity, which is 90% against a water pollutant name as methylene blue (MB) under UV–Vis light. This sample also has shown a good catalytic stability i.e 80.7%. Moreover, for electrochemical performance analysis, cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopic (EIS) tests were also performed. Among of Co-P, Co-GC and Co-SF samples, Co-SF sample has offered 1080.32 F/g specific capacitance and 86.70% capacitance retention at higher scan rate i.e 10 A/g. Additionally, this optimized sample has also maintained 83.51% capacitance even after 5000 GCD cycles performed at 1 A/g, and good conductive nature. These extraordinary results have provided new platform for water purification and energy storage appliances. [ABSTRACT FROM AUTHOR]

The heterogeneous Fenton system has drawn great attention in recent years due to its effective degradation of polluted water capability without limitation of the pH range and avoiding excess ferric hydroxide sludge. Therefore, simple chemical precipitation and vacuum filtration method for manufacturing the heterogeneous Fenton aramid nanofibers (ANFs)/ferrous oxalate (FeC2O4) composite membrane catalysts with excellent degradation of methylene blue (MB) is reported in the study. The morphology and structure of materials synthesized were characterized by scanning electron microscope (SEM), X-ray energy spectrum analysis (EDS), infrared spectrometer (FTIR), and X-ray diffraction (XRD) equipment. The 10 ppm MB degradation efficiency of composite catalyst and ferrous oxalate (FeC2O4) within 15 min were 94.5% and 91.6%, respectively. The content of methylene blue was measured by a UV-Vis spectrophotometer. Moreover, the dye degradation efficiency still could achieve 92% after five cycles, indicating the composite catalyst with excellent chemical stability and reusability. Simultaneously, the composite catalyst membrane can degrade not only MB but also rhodamine B (RB), orange II (O II), and methyl orange (MO). This study represents a new avenue for the fabrication of heterogeneous Fenton catalysts and will contribute to dye wastewater purification, especially in the degradation of methylene blue. [ABSTRACT FROM AUTHOR]

Improving the tracking and erosion resistance of silicone rubber (SiR) is of great significance to outdoor SiR insulators. In this work, a feasible method to enhance the antitracking performance of SiR by a ceramifiable system is investigated. Through scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), and other characterization methods, the mechanism that aluminum hydroxide (ATH) and low-melting glass (LMG) powder synergistically improve the tracking resistance of SiR is proposed. In this ceramifiable system, ATH plays a role in absorbing heat and serves as a precursor under the synergy with LMG, which promotes the formulation of dense mullite ceramic layer on the surface of SiR at the high temperature generated by dry band arc discharges, thereby the internal SiR is protected from degradation. Hydrophobicity and mechanical properties of ATH/LMG/SiR composites are also investigated, revealing that ATH/LMG improves the mechanical properties and hydrophobicity compared with one filler filled with the same amount. The ceramifiable system exhibits a good effect that the antitracking performance, mechanical properties, and hydrophobicity of SiR composites are improved at the same time. This system provides a new method for the research of antitracking SiR materials applied in outdoor SiR insulators. [ABSTRACT FROM AUTHOR]

Objective(s): Bioresorbable scaffolds have been advocated as the new generation in interventional cardiology because they could provide temporary scaffolds and then disappear with resorption. Although, the available stents in clinical trials exhibited biosafety, efficacy, no death, and no apparent thrombosis, Mg-substrate degradation on drug release has not been investigated. Materials and Methods: Therefore, more research has been needed to legitimize the replacement of current stents with Mg-based stents. UV-Vis spectrophotometer, scanning electron microscope (SEM), X-ray diffraction (XRD), pH measurement, H₂ evolution, and corrosion tests determined the change in hybrid properties and drug release rate. Results: The effect of Mg degradation on drug release from poly-L-lactide (PLLA) specimen was much higher than that of the L605/PLLA sample. Hydrogen evolution caused by magnesium degradation compelled everolimus out without significant PLLA decomposition during the first 100 days, while formation of Mg(OH)2 caused the PLLA to deform and crack. Conclusion: A combined mechanism of lattice/hole diffusion-dissolution governed the release of everolimus with the activation energies of 5.409 kJ/mol and 4.936 kJ/mol for the first 24 hr and diffusion coefficients 6.06×10-10 and 3.64×10-11cm2/s for the 50th to 100th days. Prolonged suppression of hyperplasia within the smooth muscle cells by hybrid stent insertion could bring about the cessation of restenosis. [ABSTRACT FROM AUTHOR]

In this paper, an artificial accelerated aging platform of Fiber Reinforced Plastic (FRP) core rod with various aging conditions, including high temperature, acid corrosion and high electric field strength, is presented. Based on that, the typical degradation characteristic of FRP core rods in decay-like fracture insulators are simulated and verified. A thermal infrared imager is used to detect the temperature rise when the AC voltage is applied. The results show that the temperature of the FRP specimens under multiple stresses is significantly increased up to 61 °C (177%) compared with the specimen under single aging stress (22 °C). Moreover, Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and Thermal Gravimetric Analysis (TGA) are applied to study the physicochemical properties of the aging FRP specimen and the reaction occurred in the degradation process and the influence mechanism among different aging factors. The results show that the epoxy resin matrix is eroded by water and nitric acid. In the presence of a high electric field, the epoxy resin matrix is further degraded and evaporated. Then the interface between the epoxy resin and the glass fiber separates and develops, accompanied by ion-exchange and hydrolysis process. With the development of the degradation process of FRP core rod, obvious carbonized channel can be detected. Finally, electric erosion puncture occurs and breakdown happens. Compared with the FRP core rod extracted from the decay-like fractured composite insulators, the artificial accelerated aging sample shows the similar change trend on physicochemical properties. This work can provide theoretical support for the FRP core rod degradation mechanism and life predicting of high voltage composite insulators or other actual operation environment. [ABSTRACT FROM AUTHOR]

This study examined the use of modified multiwall carbon nanotubes (M-MWCNTs) with immobilized laccase (L@M-MWCNTs) for removing ciprofloxacin (Cip), carbamazepine (Cbz), diclofenac (Dcf), benzo[a]pyrene (Bap), and anthracene (Ant) from different water samples. The synthesized materials were characterized using an array of advanced analytical techniques. The physical immobilization of laccase onto M-MWCNTs was confirmed through Scanning electron microscope (SEM)-dispersive X-ray spectroscopy (EDS) analysis and Brunner-Emmet-Teller (BET) surface area measurements. The specific surface area of M-MWCNTs decreased by 65% upon laccase immobilization. There was also an increase in nitrogen content seen by EDS analysis asserting successful immobilization. The results of Boehm titration and Fourier transform infrared (FTIR) exhibited an increase in acidic functional groups after laccase immobilization. L@M-MWCNTs storage for two months maintained 77.8%, 61.6%, and 57.6% of its initial activity for 4 °C, 25 °C, and 35 °C, respectively. In contrast, the free laccase exhibited 55.3%, 37.5%, and 23.5% of its initial activity at 4 °C, 25 °C, and 35 °C, respectively. MWCNTs improved storability and widened the working temperature range of laccase. The optimum removal conditions of studied pollutants were pH 5, 25 °C, and 1.6 g/L of M-MWCNTs. These parameters led to >90% removal of the targeted pollutants for four treatment cycles of both synthetic water and spiked lake water. L@M-MWCNTs demonstrated consistent removal of >90% for up to five cycles even with spiked wastewater. The adsorption was endothermic and followed Langmuir isotherm. Oxidation, dehydrogenation, hydroxylation, and ring cleavage seem to be the dominant degradation mechanisms. [Display omitted] • The synergistic effects of adsorption and degradation have been investigated. • L@M-MWCNT exhibits high thermal stability and excellent recovered activity. • L@M-MWCNTs performed well for 12 cycles. • The optimum removal conditions were pH 5, 25 °C, and M-MWCNTs dosage of 1.6 g/L. • Electrostatic attraction and precipitation are the likely adsorption mechanisms. [ABSTRACT FROM AUTHOR]

The escalating increase in the presence of organic and pharmaceuticals residues in the water bodies poses a serious environmental challenge, demanding the efficient photocatalyst for the remediation of microbial and hazardous contaminates. In this context the study addresses the synthesis of ZnO/Bi 2 O 3 composites as an efficient degradation and microbial agents. The hydrothermal prepared nano-structures with (1 %, 3 %, 5 %, 7 %) Bismuth oxide (Bi 2 O 3) concentration delves into an array of characterizations. The X-ray Diffraction (XRD) and Scanning Electron Microscopes (SEM) demonstrate structural and morphological analysis of nano composites. Brunauer Emmett Teller analysis (BET) showcased the surface area while Zeta potential analyzes the electrical conductivity of sample. Additionally, Ultraviolet Visible Spectroscopy (UV) and Photoluminescence Spectroscopy (PL) describe the optical properties of fabricated composites. The results reveal the synergistic effect that leads the effective dual applications of ZnO/Bi 2 O 3 against the environmental concern. Our study finds out the efficient degradation of organic substances (MB dye and pharmaceutical Tetracycline) and strong reduction of pathogenic bacteria under exposes of 5 % ZnO/Bi 2 O 3 composites (optimal sample). [Display omitted] [ABSTRACT FROM AUTHOR]

Novel ternary Zn-Cu-xAg alloys are designed and fabricated by the casting method under a vacuum atmosphere and then homogenized at 350 °C for 15 h. The effect of Ag concentration (x: 0, 1, 2, 3, and 4 wt%) on microstructure, hardness, in vitro corrosion, biodegradability, and bacterial sensitivity was studied systematically. The structural analysis of the alloys was investigated by using a scanning electron microscope (SEM-EDS), and an optical microscope (OM). Besides, phase characterization of the samples was conducted using X-ray diffraction (XRD). The degradation behaviors of the alloys were determined under in vitro conditions, electrochemical polarization, and immersion tests (up to 21 days) in artificial urine (AU) solution. The maximum hardness value for Zn-1Cu-4Ag alloy was about 2.38 times higher than pure Zn due to solid-solution strengthening and precipitation hardening of (Ag, Cu)Zn 4 phases. The highest and lowest I corr values, reference also corrosion rate, were calculated in Zn-1Cu and Zn-1Cu-3Ag alloys as 17.13 and 1.318 mA·cm−2, respectively. The alloys' bacterial sensitivities were evaluated with the disc diffusion test for E. coli and S. aureus. The inhibition ratio of the Zn-1Cu-1Ag was higher than the inhibition rates of the other alloys on E. coli and S. aureus. In addition, the biological properties of the generated material were promising by altering cell survival/death ratio in both prostate epithelial and bladder cancer cells related to their use potential in urology. • Novel Zn-Cu-Ag alloys were fabricated under vacuum for medical implant applications. • Varying Ag concentrations affected microstructure, hardness, biodegradability, and bacterial sensitivity. • Zn-1Cu-4Ag showed about 2.38x higher hardness than pure Zn due to solid-solution strengthening. • Zn-Cu-1Ag showed higher bacterial inhibition rates than other alloys, demonstrating potential use in urology. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract A novel Fe 3 O 4 -CeO 2 /activated carbon (AC) composite was synthesized by an immersion-precipitation process. The Fe 3 O 4 -CeO 2 /AC composite was characterized by BET surface area measurement, Fourier Transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopic (XPS), and vibrating sample magnetometer (VSM). Its catalytic activity was evaluated by azo organic dye Orange G (OG) oxidation in heterogeneous Fenton system. Due to excellent performance of AC in adsorption and conductivity, the catalyst exhibited enhanced catalytic activity compared with AC-Fe 3 O 4 , CeO 2 -AC, Fe 3 O 4 -CeO 2 and AC. Some parameters, such as initial concentration of OG, pH, catalyst loading, H 2 O 2 dosage, were studied. At pH 2.5, H 2 O 2 18 mM, OG 50 mg L−1, Fe 3 O 4 -CeO 2 /AC 0.4 g L−1 and 35 °C, the OG removal rate and the total organic carbon (TOC) removal reached 98.8% and 56.3% within 60 min. The stability and reusability of the Fe 3 O 4 -CeO 2 /AC were also tested. Besides a possible OG degradation pathway was proposed and eight intermediates were determined. [ABSTRACT FROM AUTHOR]

Abstract This paper aims to investigate the mechanical response behavior of CFRP/Al single-lap bolted joints in marine environment. The joints with four interference fit sizes (0%, 0.42%, 2.14% and 3.02%) were prepared, and fully and half immersed in 3.5% sodium chloride solution with a controlled temperature of 30 °C for four months. Single-lap bearing tests were carried out to evaluate the mechanical behavior and failure mode of the CFRP/Al bolted joints after seawater ageing. Scanning electron microscope (SEM) was used to analyze the environmental damage and failure mechanism of structures. The results show that the critical load-bearing capacity and the maximum friction force at the overlap gradually decreased with the increasing of ageing time, and it was more serious in half immersion ageing environment compared with full immersion. The interference fit significantly improved the mechanical properties of joints, especially for 2.14% interference fit. Environmental damage such as pitting, delamination and fiber-matrix interface debonding was all aggravated with the increasing ageing time but suppressed by interference fit. In addition, the failure modes of structures were bearing failure and shear-out failure of CFRP, and the failure mechanism was delamination for unaged structures, the interlayer shear damage for aged structures. [ABSTRACT FROM AUTHOR]

In the present investigation, long term service performance of silicone rubber based polymeric insulators under DC stress with controlled climatic conditions is attempted. Simultaneous application of UV, thermal, humidity with DC electrical stress is applied to polymeric insulators enclosed in a specially fabricated climatic chamber. The stresses are applied for 1000 h for an adopted cycle to simulate close service life conditions. The leakage current is regularly monitored and recorded. After the experimentation, samples of the aged specimen are subjected for post analysis and psycho-chemical analysis like Scanning Electron Microscope (SEM) to monitor morphological changes, Energy Dispersive X-Ray analysis (EDAX) to observe elemental presence over the surface, Fourier Transform Infra-Red (FTIR) spectroscopy to examine chemical changes in the material, Thermo-gravimetric analysis (TGA) to understand the role of filler in aged insulator specimen and loss of Loss of hydrophobicity was measured. Investigations with long duration DC stress reveal material degradation, depolymerization and loss of ATH; this could result in low thermal stability and accelerate the thermal erosion and early failures. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish a new model to reflect the real ultrasound pretreatment process on rice protein (RP). In this study, ultrasound treatment affected the yield of soluble protein of RP significantly and also improved the enzymatic hydrolysis efficiently. However, the aggregation of soluble protein occurred when ultrasonic power density and temperature reached a high level. The traditional model cannot reflect the real pretreatment process on RP due to the aggregation of protein. In this paper, a modified kinetic model was thus established by introducing a parameter of aggregation coefficient based on the Fick’s second law, suggesting the two coefficients were highly dependent on the ultrasonic power density and temperature. Besides, the results of scanning electron microscope (SEM) both the untreated and samples pretreated by ultrasound indicated that the enzymatic hydrolysis efficiency was influenced by changing the structure of RP. Thereto, ultrasound treatment at proper conditions can shorten the enzymolysis time of RP and improve the efficiency of hydrolysis. [ABSTRACT FROM AUTHOR]

A heterogeneous photocatalyst, TiO 2 -functionalized magnetic activated carbon (T@MPAC), was fabricated as a novel peroxymonosulfate (PMS) activator for improving the oxidative degradation of benzotriazole (BTA) in aqueous media. For characterization of the features of the synthesized catalyst, XRD, FESEM, EDS, BET, TEM, PL and UV-vis DRS techniques were applied. Influence of operating parameters namely solution pH, reaction time and catalyst dosages, PMS and BTA was studied in a batch environment. A plausible oxidation mechanism and reaction pathway for BTA degradation was proposed. Potential catalytic, recyclability, durability and quenching studies were performed. The catalytic activity of T@MPAC in the activation of different oxidants also evaluated. Under optimized conditions, the degradation and mineralization rates of BTA were found to be 71.6 and 38.7%, respectively, after the fifth cycles. The catalytic activity of T@MPAC on BTA degradation was improved with the suitability in order of PMS > persulfate > ozone > H 2 O 2 . The trapping experiments confirmed the participation of OH, SO 4 − , O 2 − radicals as reactive species in the system. Among the reactive species (i.e. OH, SO 4 − , O 2 − and holes) included in T@MPAC/PMS/UV system, SO 4 − radicals had dominant role in controlling the oxidation reaction. Decreasing the degradation rate in the presence of scavenger agents was as IPA > BQ > t -BuOH > KI. The catalytic performance dropped in the presence of chloride ions, while it was less affected by phosphate, nitrate and sulfate anions. The catalyst showed a good recyclability and stability after five consecutive uses. To conclude, coupling of T@MPAC/UV and PMS can be successfully applied as a novel and effective technique to degrade organic substances in wastewater, due to easy recoverable, high catalytic activity and the cogeneration of different reactive species. [ABSTRACT FROM AUTHOR]

The short-circuit behavior of power devices is highly relevant for converter design and fault protection. In this paper, the degradation during short circuit of a 10-kV 10-A 4H-SiC MOSFET is investigated at 6 kV dc-link voltage. The study aims to present the behavior of the device during short-circuit transients as it sustains increasing short-circuit pulses during its lifetime. As the short-circuit pulse length increases, degradation of the device can be observed in periodically performed characterizations. The initial degradation seems to be associated with the channel region, and continuous stressing leads to an overall increase in device on-state resistance at the end of the degradation study. Thermal simulation shows that the surface aluminum metalization reached its melting temperature and the top part of the device reaches temperatures above the rated junction temperature. Scanning electron microscope investigation shows aluminum reconstruction and cavities at the contact interface between the aluminum surface metalization and source contacts. [ABSTRACT FROM PUBLISHER]

In this paper, degradation behaviors of bridged-grain (BG) polycrystalline silicon (poly-Si) thin-film transistors (TFTs) are systematically characterized and investigated. Device degradation exhibits a two-stage behavior, which is related to pulse falling time ( tf ). A faster tf brings a larger ON-current ( I\mathrm{\scriptscriptstyle ON} ) increase in the first stage and a larger I\mathrm{\scriptscriptstyle ON} decrease in the second stage. Electron trapping/injection into gate oxide and dynamic hot carrier effect are found to be responsible to I\mathrm{\scriptscriptstyle ON} increase in the first stage and I\mathrm{\scriptscriptstyle ON} decrease in the second stage, respectively. Compared with normal poly-Si TFTs, BG poly-Si TFTs show much more reliable performance under the same dynamic gate stress. The larger I\mathrm{\scriptscriptstyle ON} increase in the first stage in BG poly-Si TFTs is attributed to the enhanced vertical electric field in the channel near the gate oxide, while the much smaller I\mathrm{\scriptscriptstyle ON} decrease in the second stage is attributed to lateral electric field reduction caused by the sharing of the field across multiple reversely biased junctions inside the active channel. Incorporated with transient simulations, the degradation mechanisms for both the first stage and the second stage are elucidated. In addition, the impact of the first-stage degradation on the second-stage degradation is also clarified. [ABSTRACT FROM PUBLISHER]

Background: This paper investigates a range of analytical techniques to yield information about the materials and processes used in making painted banners. A textile conservator, technical art historian and paintings conservator, and materials scientist have joined forces to develop a greater understanding of the potential of analytical findings in the identification of materials. Results: Visual examination using low level magnification and microscopy proved to be a crucial starting point and for identification of areas for further analysis. High magnification microscopy of cross sections was invaluable to gather information regarding the build-up of the layers, their interaction and condition. Scanning electron micros- copy (SEM) of ion-milled samples showed that different areas of the banner had been prepared in different ways. SEM-EDX (scanning electron microscopy energy-dispersive X-ray spectroscopy) confirmed the presence of the main elements of pigments. Raman enabled identification of specific pigments. Raman also provided confirmation of specific materials (such as the paint filler). Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) enabled the identification of oil and resin, confirmation of pigments and fibres. Thin layers made sampling and identification challenging. Presence of materials such as silk and lead white dominated some analysis making interpretation of other materials more difficult. Conclusions: Sample preparation had a significant bearing on the effectiveness of the analysis. Ion-milling provided high quality surface on the cross section samples that enabled material interfaces to be clearly seen. The challenges of finding effective wavelengths for analysis of samples using Raman were clearly evident in this study. Microscopy showed fibres blends, easily missed using FTIR, whereas FTIR was particularly effective in the identification of man- made fibres. While portable instrumentation may be useful, for in-depth understanding of the heterogeneous layered materials sample taking still remains crucial. Commercial makers used many typical grounds and pigments but these were used sparingly, in thin layers, in order to produce a flexible object and also perhaps to reduce costs. The textile was however of high quality, in this case silk. Unexpectedly, the preparation layers do not appear to be consistent across the banner; the reasons for this need further investigation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A promotion of Palladium on BiPO 4 was fabricated for HCHO degradation. • The possible catalytic mechanism of the HCHO degradation was proposed. • Explanation of mechanism by DFT theory. • It exhibits the highest HCHO degradation rate (81%). In this paper, the facile hydrothermal technique was used to create a high-performance serial of Pd/BiPO 4 photocatalysts, which were then used to degrade gaseous formaldehyde into CO 2 and H 2 O in a photoreactor chamber without secondary contaminations under UV radiation. X-ray diffraction (XRD), Ultraviolet–visible spectroscopy, Transmission Electron Microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX), field-emission scanning electron microscope (FESEM) and photoluminescence spectra (PL) were used to characterize all the as-prepared Pd/BiPO 4 samples. The photocatalytic performances of the as-prepared Pd/BiPO 4 for the degradation of gaseous formaldehyde were investigated under UV irradiation. The experimental results manifested that Pd/BiPO 4 exhibited higher photocatalytic activities, as compared to the pure BiPO 4. Especially, 1% Pd/BiPO 4 presented the highest photocatalytic performance for the degradation of formaldehyde, which improved the degradation efficiency up to 81% after 240 min under UV irradiation. Moreover, based on experimental results a possible photocatalytic mechanism was proposed. The predicted reaction mechanism was also verified with the density functional theory (DFT) calculations with very similar results. As a result, this work provides a useful model for designing efficient photocatalysts for the elimination of air pollution. [ABSTRACT FROM AUTHOR]

Abstract: Uniform immobilization of BiVO4 on silica fiber was successfully achieved via a combined alcohol-thermal and carbon nanofibers template route. The physicochemical properties of the obtained material were characterized by means of X-ray diffraction, field emission scanning electron microscopy, Raman spectrometer, Brunauer–Emmett–Teller apparatus, and ultraviolet–visible diffuse reflectance spectroscopy. Notably, the immobilized BiVO4 sample exhibited remarkable enhanced visible light photocatalytic degradation of an aqueous solution of rhodamine B (86.3% within 180min), far exceeding that of the corresponding powder BiVO4 sample (32.5% within 180min). It is expected that such unique immobilized BiVO4 material would possess many potential applications in photocatalysis. [Copyright &y& Elsevier]

Highlights: [•] Alkalis doped TiO2 were prepared using solvothermal method at low temperature. [•] The obtained samples were characterized by XRD, Raman, FT-IR, UV–vis DRS and SEM. [•] The catalysts show enhanced photocatalytic activity for the degradation of methyl orange. [ABSTRACT FROM AUTHOR]

Bi 2 O 2 CO 3 is a Bi-based semiconductor catalyst. In this paper, microspherical Bi 2 O 2 CO 3 was prepared by hydrothermal method. The crystal structure, microscopic morphology and optical properties of the samples were characterized by X-ray Diffraction, Scanning Electron Microscope and UV–vis diffuse reflectance spectroscopy. The ultrasonic catalytic activity of Bi 2 O 2 CO 3 was evaluated using methyl green as a model contaminant. The degradation of methyl green by Bi 2 O 2 CO 3 adsorption, ultrasonic radiation, and ultrasound synergized with Bi 2 O 2 CO 3 catalysis were investigated. The results show that the degradation rates of the three methods are in order: Bi 2 O 2 CO 3 adsorption＜ultrasonic radiation＜ultrasound synergized with Bi 2 O 2 CO 3 catalysis. This indicates that the Bi 2 O 2 CO 3 microspheres showed good ultrasonic catalytic activity. In addition, the effects of ultrasonic power, ultrasonic duty ratio, Bi 2 O 2 CO 3 concentration and pH on the ultrasonic catalytic efficiency were also investigated. The optimal degradation conditions were determined (ultrasonic power is 400 W, ultrasonic duty ratio is 9:1, Bi 2 O 2 CO 3 concentration is 1.5 g/l, pH is 11, reaction time is 80 min). Active substances such as ·OH, 1O 2 , HO 2 ·, H 2 O 2 , and photogenerated holes may be produced in the process of methyl green degradation by ultrasound synergized with Bi 2 O 2 CO 3 catalysis. These active substances with strong oxidizing properties can decompose methyl green into CO 2 , HO 2 and other non-toxic small molecule compounds. Photogenerated holes can degrade methyl green directly or react with –OH in solution to produce more ·OH and thus significantly increase the degradation rate of methyl green. The results indicate that ultrasound synergized with Bi 2 O 2 CO 3 catalysis is of great potential application value in removal of organic pollution and environmental purification. Degradation mechanism of methyl green by US/Bi 2 O 2 CO 3. [Display omitted] [ABSTRACT FROM AUTHOR]

Alginate hydrogels have the most extensively explored injection system among natural molecular. The injectable alginate hydrogel has special physical and biological properties without toxicity, therefore, it has been served as minimally invasive treatments to treat various irregular defects. However, the inconvenient truth is low formability and poor mechanical properties of injectable alginate hydrogels; besides, there are little relevant studies about controlling, measurement and analysis of the sol-gel transition and degradation process. We synthesized an injectable nanocomposite alginate hydrogel, used specific methods and equipment to regulate and evaluate the sol-gel transition of the hydrogel, moreover, we researched the degradation behaviour using scanning electron microscope, nano-indenter and titration analysis. The results showed that gelation time and mechanical properties could be regulated and effectively described. Compression properties of the hydrogels increased to 150%–300% compared with common alginate hydrogels, in addition, the degradation behaviour with ions release could be regulated by the formula. The results will be propitious to solve problems in quality control of hydrogel manufacturing engineering and the nanocomposite hydrogels with good biocompatibility will have great potential for multifunctional biological scaffolds and tissue engineering. • Low formability and poor mechanical properties limit injectable alginate hydrogels' application. • Nanocomposite alginate hydrogels with regulable sol-gel transition and double-network structure. • Designed new methods and provided detailed observations of the sol-gel transition for quality control. • Relatively stable mechanical property and sustained release property during degradation. [ABSTRACT FROM AUTHOR]

In this study, Chalcopyrite (CuFeS2) was prepared by a hydrothermal and co-precipitation method, being represented as H-CuFeS2 and C-CuFeS2, respectively. The prepared CuFeS2 samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy mapping (EDS-mapping), powder X-ray diffractometer (XRD), X-ray photoelectron spectrometry (XPS), and Raman microscope. Rhodamine B (RhB, 20 ppm) was used as the target pollutant to evaluate the degradation performance by the prepared CuFeS2 samples. The H-CuFeS2 samples (20 mg) in the presence of Na2S2O8 (4 mM) exhibited excellent degradation efficiency (98.8% within 10 min). Through free radical trapping experiment, the major active species were •SO4− radicals and •OH radicals involved the RhB degradation. Furthermore, •SO4− radicals produced from the prepared samples were evaluated by iodometric titration. In addition, one possible degradation mechanism was proposed. Finally, the prepared H-CuFeS2 samples were used to degrade different dyestuff (rhodamine 6G, methylene blue, and methyl orange) and organic pollutant (bisphenol A) in the different environmental water samples (pond water and seawater) with 10.1% mineral efficiency improvement comparing to traditional Fenton reaction. [ABSTRACT FROM AUTHOR]

Abstract: The present study described the degradation behavior of tetrabromobisphenol A (TBBPA) in Fe–Ag suspension solutions under ultrasonic radiation (US). The Fe–Ag bimetallic nanoparticles with core–shell structure were successfully synthesized by reduction and deposition of Ag on nanoscale Fe surface, and were further characterized by BET, XRD, TEM, SEM, X-ray fluorescence and X-ray photo-electron spectroscopy. The results revealed that the displacement plating produced a non-uniform overlayer of Ag additive on iron; the as-synthesized bimetallic nanoparticles were spherical with diameters of 20–100nm aggregated in the form of chains. Batch studies demonstrated that the TBBPA (2mgL−1) was completely degraded in 20min over Fe–Ag nanoparticles, which has higher degradation efficiency than Fe0 nanoparticles under US. The effects of Fe–Ag bimetallic nanoparticles loading, initial TBBPA concentration, pH of the solution, Ag loading and temperature on the reduction efficiency of TBBPA under US were investigated. The complete reduction of TBBPA in 20min was determined selectively under the conditions of pH (pH=6.0±0.5), Agloading(1wt.%) at 30°C over the fabricated Fe–Ag nanoparticles. Additionally, the major intermediates identified by LC–MS technique were tri-BBPA, di-BBPA, mono-BBPA and BPA and the degradation mechanism was also proposed. [Copyright &y& Elsevier]

Paper has become the basic elixir in everyone's activities and usage of paper has increased day by day, the waste generated by paper is also enormous. The primary source of paper is wood (tree) yet, waste paper is environmentally good and biodegradable; however, it is the primary source of deforestation. Current research aims to find an alternate way to recycle paper in the biological approach. Hence in our work, twelve cellulose-producing bacteria were isolated, out of which one bacterial strain proved to be the best. Cellulase enzyme was extracted and purified, and used for enzymatic de-inking of photocopy papers. The optimal conditions for cellulase synthesis were at 60 °C, glucose as the only carbon source, and potassium nitrate as the nitrogen source. The enzyme demonstrated excellent de-inking at a lower pulp consistency of 3% with a 20% enzyme dose. The cellulose and hemicellulose levels decreased, which can be attributed to fiber breaking. Further, the changes in the functional groups identified by Fourier-transform infrared spectroscopy analysis and the changes in the surface morphology of the pulp fibers were obtained using scanning electron microscope analysis. [Display omitted] • The microbial cellulase enzyme produced was effective in the deinking process. • Bacillus wiedmannii was molecularly characterized, it generated 0.0591U/ml cellulase enzyme. • This work demonstrated that 3% of paper pulp could be handled with a 20% enzyme dose. • Bio-deinking is a new and unexplored method with a promising future. [ABSTRACT FROM AUTHOR]

Electrospinning is an innovative new fibre technology that aims to design and fabricate membranes suitable for a wide range of tissue engineering (TE) applications including vascular grafts, which is the main objective of this research work. This study dealt with fabricating and characterising bilayer structures comprised of an electrospun sheet made of polycaprolactone (PCL, inner layer) and an outer layer made of poly lactic-co-glycolic acid (PLGA) and a coaxial porous scaffold with a micrometre fibre structure was successfully produced. The membranes' propriety for intended biomedical applications was assessed by evaluating their morphological structure/physical properties and structural integrity when they underwent the degradation process. A scanning electron microscope (SEM) was used to assess changes in the electrospun scaffolds' structural morphology such as in their fibre diameter, pore size (μm) and the porosity of the scaffold surface which was measured with Image J software. During the 12-week degradation process at room temperature, most of the scaffolds showed a similar trend in their degradation rate except the 60 min scaffolds. The coaxial scaffold had significantly less mass loss than the bilayer PCL/PLGA scaffold with 1.348% and 18.3%, respectively. The mechanical properties of the fibrous membranes were measured and the coaxial scaffolds showed greater tensile strength and elongation at break (%) compared to the bilayer scaffolds. According to the results obtained in this study, it can be concluded that a scaffold made with a coaxial needle is more suitable for tissue engineering applications due to the improved quality and functionality of the resulting polymeric membrane compared to the basic electrospinning process. However, whilst fabricating a vascular graft is the main aim of this research work, the biological data will not present in this paper. [ABSTRACT FROM AUTHOR]

Abstract: In the first part of the paper the structural scale tests on the synergistic effects of moisture, temperature, alkalinity and stress level on the performance and durability of GFRP sheet bonded externally on concrete have been discussed. This part describes the microstructural studies to find out the nature, quantum and mechanism of deterioration in the conditioned sheets. Micrographic investigations were carried out using a scanning electron microscope (SEM) to visualize the changes in the microstructure. The other tests are energy dispersive X-ray analysis (EDX) and inductively coupled plasma mass spectrometry (ICP-MS) to determine the chemical changes in the composite. [Copyright &y& Elsevier]

Abstract: The Cu-doped tungsten bronze (TB) type potassium niobate K2Nb4O11 was synthesized by solid-state reaction method in air. The crystal structure and morphology of the prepared samples were confirmed by X-ray diffraction analysis and scanning electron microscope. The photocatalytic activity of the prepared samples was evaluated using acid red G as a model organic compound and the photocatalytic reaction belongs to the first order kinetics. The results show that Cu-doping significantly increased the photocatalytic activity of K2Nb4O11 catalyst when the concentration of Cu-doped was lower, but the photocatalytic activity of the catalyst was decreased when the concentration of Cu-doped was higher. Although the surface areas of the 0.2wt.% Cu-doped K2Nb4O11 and the 0.5wt.% Cu-doped K2Nb4O11 are very lower, the photocatalytic activities of these compounds are close to that of TiO2–P25. Copper doping is good for the compounds to form tetragonal TB structure and improving the crystallinity of the compounds. The diffuse reflectance spectrum of Cu-doped K2Nb4O11 showed a red shift. X-ray photoelectron spectroscopy analysis confirmed that the niobium with mixed valence state exists in the crystal structure of the compound K2Nb4O11. The effects of the Cu-doped and the mixed valence state of niobium on the photocatalytic activity of the catalyst were discussed. [Copyright &y& Elsevier]

The current study aimed to evaluate the characteristics and the effects of degradation on the structural properties of Poly(lactic-co-glycolic acid) (PLGA)- and polycaprolactone (PCL)-based nanofibrous scaffolds. Six scaffolds were prepared by electrospinning, three with PCL 15% (w/v) and three with PLGA 10% (w/v), with electrospinning processing times of 30, 60 and 90 min. Both types of scaffolds displayed more robust mechanical properties with increased spinning times. The tensile strength of both scaffolds with 90-min electrospun membranes did not show a significant difference in their strengths, as the PCL and PLGA scaffolds measured at 1.492 MPa ± 0.378 SD and 1.764 MPa ± 0.7982 SD, respectively. All membranes were shown to be hydrophobic under a wettability test. A degradation behaviour study was performed by immersing all scaffolds in phosphate-buffered saline (PBS) solution at room temperature for 12 weeks and for 4 weeks at 37 °C. The effects of degradation were monitored by taking each sample out of the PBS solution every week, and the structural changes were investigated under a scanning electron microscope (SEM). The PCL and PLGA scaffolds showed excellent fibre structure with adequate degradation, and the fibre diameter, measured over time, showed slight increase in size. Therefore, as an example of fibre water intake and progressive degradation, the scaffold's percentage weight loss increased each week, further supporting the porous membrane's degradability. The pore size and the porosity percentage of all scaffolds decreased substantially over the degradation period. The conclusion drawn from this experiment is that PCL and PLGA hold great promise for tissue engineering and regenerative medicine applications. [ABSTRACT FROM AUTHOR]

The photocatalytic dye degradation of pure α-Fe 2 O 3 and different concentration of Co doped α-Fe 2 O 3 is explored. Facile hydrothermal method were employed to prepare pristine, 2% and 4% Co–Fe 2 O 3 nanoparticles. Further, synthesized product confirmation studies were employed from X-ray diffraction, UV–vis spectrometry, Fourier-transform infrared, Raman, scanning electron microscope and transmission electron microscope studies. The rhombohedral nanoparticles developed were enhanced photocatalytic action. Photocatalytic dye degradation studies were analyzed for prepared three samples and the photocatalytic efficacy of the obtained photocatalysts was compared experimentally. Methylene blue dye was degraded under UV-light irradiation with 364 nm. The results showed that 4% Co doped α-Fe 2 O 3 sample exhibited better dye degradation with 92% efficiency. The 4% doping of cobalt ions enhanced the photocatalytic property of Fe 2 O 3 and is a good candidate for methylene blue dye degradation above 90%. In addition, strategy for photocatalytic efficiency enhancement was proposed. • A strategy for photocatalytic efficiency enhancement was proposed. • 4% Co–Fe 2 O 3 enhanced the photocatalytic activity. • 4% Co–Fe 2 O 3 explored dye degradation with 92% efficiency. • Cobalt ions doping enhanced Fe 2 O 3 photocatalytic property. [ABSTRACT FROM AUTHOR]

High-T/sub c/ Tl-base oxides can be synthesized by a diffusion reaction within a short reaction time. The F addition apparently promotes the phase transformation from 2223 to 1223. The scanning electron microscope observation reveals that the 1223 phase formed by the F addition shows a dense and homogeneous structure, resulting in an increase in transport I/sub c/ at 77 K. Moreover, F addition significantly improves the I/sub c/ at 77 K under magnetic field, and shifts the irreversibility line to higher temperature. Meanwhile, V addition was found to enhance the diffusion reaction, resulting in the formation of 2223 layer of about 600 pm in thickness after the reaction at 850/spl deg/C for 2 h. The V is pushed out from the diffusion layer and accumulates on the surface of the specimen. The V addition causes almost no degradation in T/sub c/. I/sub c/-B performance is appreciably improved by annealing in O/sub 2/ after the reaction. [ABSTRACT FROM PUBLISHER]

The design of eco-friendly Bi 1.81 MnNbO 6.72 /sulfite system for efficient degradation of chlortetracycline was achieved. The feasibility of synthesizing Bi 1.81 MnNbO 6.72 by hydrothermal method was determined by X-ray diffraction. The magnetic test suggested that Bi 1.81 MnNbO 6.72 possessed paramagnetic properties, indicating unpaired electrons were present. Scanning electron microscope and transmission electron microscopy images revealed that Bi 1.81 MnNbO 6.72 octahedra exhibited exposed [1,1,1] crystal plane containing high density of Bi, Mn and Nb metal atoms. Large numbers of metal atoms will facilitate heterogeneous catalytic process. In a batch system with aeration, Bi 1.81 MnNbO 6.72 could be used as sulfite activator for the disposal of chlortetracycline. The reaction kinetics of the degradation process conformed to the pseudo-second-order kinetic model. In Bi 1.81 MnNbO 6.72 /sulfite process, initial pH, Bi 1.81 MnNbO 6.72 dosage, sulfite and chlortetracycline concentrations, as well as inorganic salt ions had great effect on chlortetracycline degradation. Under optimal conditions, the efficiency of Bi 1.81 MnNbO 6.72 /sulfite system for degradation of chlortetracycline could reach 76.2%. Moreover, Mn (II) plays a key role in the initiation of the catalytic reaction in Bi 1.81 MnNbO 6.72 /sulfite process. Generated SO 3 ●‒ could act as main reactive species in Bi 1.81 MnNbO 6.72 /sulfite process, while HO● was also involved. Three new degradation products were detected by UHPLC/MS/MS and the possible degradation pathways in this system were proposed. Based on this, we believe that Bi 1.81 MnNbO 6.72 /sulfite is a type of process for degradation of organic contaminants with research significance and application prospects. Image 1 • A hydrothermal method for preparing Bi 1.81 MnNbO 6.72 was developed. • An efficient Bi 1.81 MnNbO 6.72 /sulfite system with aeration was established for the removal of chlortetracycline. • Three new transformation products of chlortetracycline were elucidated. • The key role of SO 3.●‒ during heterogeneous catalytic process was confirmed. [ABSTRACT FROM AUTHOR]

Geopolymers are synthesized by mixing powdery solids, rich in amorphous silicon and aluminum species, with an alkaline solution, which leads to the formation of an inorganic alumosilicate network. Their acid resistance is affected by the composition, the porosity, and pore size distribution of the hardened binder as well as the type and concentration of the acidic solution. In the present study, two geopolymer mixtures with varying liquid-to-solid ratios and Si/Al ratios were exposed to a sulfuric acid solution (pH = 1) and analyzed after different durations of exposure (7, 14, 28, 56, and 70 days) by using a light microscope and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). SEM-EDX elemental mapping was used to evaluate the degradation from depth profiles of silicon (Si), aluminum (Al), and potassium (K) leaching. The results clearly show the leaching kinetics of potassium and the dealumination of the network. The separate consideration of specific reaction steps in the course of degradation, namely the depth of erosion (DE), the depth of deterioration (DD), and the depth of reaction for certain elements (DR(e)), indicate a combination of chemical and diffusion controlled degradation mechanisms. [ABSTRACT FROM AUTHOR]

This study investigates the effects of gamma rays at different total irradiation doses on polyamide reverse osmosis (RO) membranes under aqueous or anhydrous conditions. ATR–FTIR, XPS, Raman, SEM and AFM microscopes are used to observe the chemical structure and morphology of the membrane separation layer before and after irradiation. The effects of irradiation on the filtration properties (water flux and salt rejection), mechanical properties and hydrophilic properties of RO membranes are examined. Results show that the degradation mechanism or path of the membrane separation and support layers are different under aqueous and anhydrous conditions. The results of different analyses reveal that the rupture of amide bond under anhydrous conditions is significantly higher than that under aqueous conditions. Under both conditions, when the total radiation dose was less than 100 kGy, the performance of polyamide membrane is slightly improved. Thus, irradiation positively affects the membrane. When the dose reached 200 kGy, chain breakage and collapse due to radiation are widespread, thereby yielding prominent changes in the properties and morphology of the membrane, most seriously under the anhydrous condition. This study provides a reference for the application of polyamide RO membrane in radioactive liquid waste and an effective method for the modification of polyamide membranes. • The effect of gamma radiation on the properties of polyamide RO membrane is rendered. • The rupture of the amide bond under anhydrous conditions is significantly higher than that under aqueous conditions. • The membrane performance improves slightly at low total irradiation doses (less than 100 kGy) under both conditions. • The obvious degradation of the RO membrane after irradiation occurs at 200–500 kGy. [ABSTRACT FROM AUTHOR]

• α-Fe 2 O 3 /TiO 2 heterogeneous composites are synthesized by the sol-gel process. • Additions of α-Fe 2 O 3 to TiO 2 widened the visible light absorption ability of TiO 2. • An enhanced photoactivity is obtained by α-Fe 2 O 3 /TiO 2 heterogeneous composite powders as compared to the pristine α-Fe 2 O 3 and TiO 2 powders. • The active species generated during the photocatalytic process are OHO2−, and holes. α-Fe 2 O 3 /TiO 2 heterogeneous composites were synthesized by the sol-gel process to increase the photocatalytic activity of TiO 2. The structural, morphological, and optical characteristics of the composites were determined by X-ray diffraction, scanning electron microscope, and UV–vis diffuse reflectance spectroscopy. Results revealed that the incorporation of α-Fe 2 O 3 to TiO 2 widened the visible light absorption ability of TiO 2. It was realized that the calcination temperature plays a crucial role in morphology development hence photocatalytic activity of the α-Fe 2 O 3 /TiO 2 heterogeneous composites. The photocatalytic activity of the composites calcined at various temperatures was evaluated for the degradation of Methylene Blue (MB) and Phenol (Ph) in aqueous medium under UV and sun-like illuminations. The α-Fe 2 O 3 -TiO 2 composites exhibits superior photocatalytic efficiency to degrade both MB and Ph as compared to both pristine TiO 2 and pristine α-Fe 2 O 3 under sun-like illumination. The α-Fe 2 O 3 /TiO 2 composite degraded approximately 90 % of MB and 50 % of Ph in 180 min sun-like illumination. Improvement in photocatalytic activity is attributed to the separation of photogenerated electron/hole pairs through the interaction of α-Fe 2 O 3 and TiO 2. [ABSTRACT FROM AUTHOR]

The effect of ultraviolet radiation on styrene-ethylene-butadiene-styrene (SEBS) has been studied at different exposures times in order to obtain a better understanding of the mechanism of ageing. The polymer materials were mechanically tested and then their surfaces were analyzed using a scanning electron microscope (SEM) and atomic force microscopy (AFM). Moreover, the optical analysis of contact angle (OCA) was used to evaluate the surface energy (γs) and the yellowing index (YI) and attenuated total reflectance infrared spectroscopy (ATR–FTIR) were used to observe structural and physical changes in aging SEBS. The results obtained for the SEBS, in relation to the duration of exposure, showed superficial changes that cause a decrease in the surface energy (γs) and, therefore, a decrease in surface roughness. This led to a reduction in mechanical performance, decreasing the tensile strength by about 50% for exposure times of around 200 hours. [ABSTRACT FROM AUTHOR]

• A novel peony-like InOOH was firstly prepared via glycerol assisted solvothermal method. • The optimal proportion of glycerol was determined to be 25%. • Peony-like InOOH exhibited excellent photocatalytic activity for degrading norfloxacin. • Peony-like InOOH possessed high separation efficiency and low recombination rate of photoproduction electron-hole pairs. • The degradation mechanism of norfloxacin by peony-like InOOH was proposed. Novel peony-like InOOH photocatalyst was firstly obtained with the help of glycerol in the solvothermal process, whose optimal proportion of glycerol was determined to be 25%. X-ray diffraction, scanning electron microscope, X-ray energy dispersion spectrum, transmission electron microscopy, X-ray photoelectron spectroscopy and UV–visible diffusion reflectance spectrum were obtained and analyzed to reveal the structure, morphology, physical and chemical properties of synthesized samples. The results indicated that the synthesized InOOH was orthorhombic structure with the peony-like morphologies, whose average particle size was 2–5 µm approximately. The band-gap of the peony-like InOOH was estimated to be 3.65 eV. The photocatalytic activities of the samples were investigated by degrading norfloxacin under UV-light irradiation, which followed the first-order reaction kinetics. The degradation efficiency of peony-like InOOH could reach up to 98.84%. And the first order kinetic constant of peony-like InOOH was 0.01519 min−1, which was about 4.8 times or 1.7 times than that of hexagram-like InOOH or InOOH nanosheet. The peony-like InOOH showed the most superior photocatalytic performance compared with hexagram-like InOOH and InOOH nanosheet, which originated from its high separation efficiency and low recombination rate of photoproduction electron-hole pairs. The reduction of total organic carbon revealed the mineralization of norfloxacin during the photocatalytic process. Finally, O 2 − radicals were proved to be main reactive species during the degradation process of norfloxacin. Furthermore, the degradation pathway and the degradation mechanism of norfloxacin with peony-like InOOH as catalyst were discussed in detail. [ABSTRACT FROM AUTHOR]

Removal of 4-Nitrophenol (4-NP) compounds by the electrochemical degradation method using Ti/TiO 2 -NiO electrodes was successfully conducted. This study aims to study the activity of Ti/TiO 2 -NiO electrodes in the electrocatalytic degradation of 4-NP as organic compound pollutants. Ti/TiO 2 -NiO preparation was carried out by the wet impregnation technique, then TiO 2 -NiO composites were sprayed on the surface of Titanium electrodes. The electrode was characterized by X-Ray Diffraction (XRD), a Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and Cyclic Voltammetry (CV). A Diffractogram XRD of TiO 2 -NiO composites showed a characteristic peak of TiO 2 -NiO at 2 θ = 33°. Meanwhile, analysis of the SEM surface morphology showed that NiO with an average particle size of 22.07 μm can be attached to the surface of the Ti/TiO 2 plate. Electrocatalytic degradation of 4-NP compounds was found to be optimum at pH 11 and 80 min electrolysis time with a rate constant of 0.0373 min−1. The electrochemical degradation exhibited the percentage of removing 4-NP rate of >95% with good electrode measurement stability. • Ti/TiO 2 -NiO electrodes were designed for electrochemical 4-nitrophenol degradation. • It exhibited high catalytic degradation with the constant rate 0.0373 min−1. • Mechanism for the rate of degradation of 4-NP is proposed. • The method is promising for real water treatment. [ABSTRACT FROM AUTHOR]

The behavior of a metal-organic framework (MOF) compound synthesized in hydrothermal reaction conditions and rich in N, P, and Fe nutrients was explored in the field. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and laser induced breakdown spectroscopy (LIBS) characterization results showed that the chemical structures changed during the degradation process in crop field soil. The scanning electron microscope images showed that the micro-rod of the MOF peeled off and degraded in layers. During the growth period of wheat, the MOF degraded by 50.9%, with the degradation rate being closely related to soil temperature. It was also found that the degradation rate increased with soil temperature. Moreover, the nutrient concentration of the soil indicated that the MOF had stable nutrients release efficiencies and could provide a continuous supply of nutrients throughout the wheat growth period, which showed a great alternative for MOF as a fertilizer both benefiting agricultural production and environmental protection. [ABSTRACT FROM AUTHOR]