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991.
Gabriela Ciobanu Maria Harja Lacramioara Rusu Anca Mihaela Mocanu Constantin Luca 《Korean Journal of Chemical Engineering》2014,31(6):1021-1027
The Acid Black 172 dye adsorption on the uncalcined hydroxyapatite nanopowder was investigated. The hydroxyapatite prepared by wet coprecipitation method has high specific surface area of 325 m2/g and crystal sizes smaller than 70 nm. The batch adsorption experiments revealed that under the optimum adsorption conditions (pH 3, hydroxyapatite dosage 2 g/L, initial dye concentration 400 mg/L and temperature 20 °C) the dye removal efficiency was 95.78% after 1 h of adsorption. The adsorption kinetics was best described by the pseudo-second order kinetic model. The intraparticle diffusion model shows that intraparticle diffusion is not the sole rate-limiting step; the mass transfer also influences the adsorption process in its initial period. The Langmuir isotherm model best represented the equilibrium experimental data, and the maximum adsorption capacity (q m ) was 312.5 mg/g. 相似文献
992.
Maria Snmez Mihai Georgescu Mihaela Vlsan Marius Radulescu Denisa Ficai Georgeta Voicu Anton Ficai Laurentia Alexandrescu 《应用聚合物科学杂志》2015,132(26)
In this article, polymer composites based on polypropylene (PP) matrix reinforced with short glass fibers type E (GF‐type E) were obtained. However, to ensure good interfacial adhesion and stress transfer across the interface, the influence of the chemical functionalization of the phases was analyzed. The better interfacial adhesion is assured by the use of maleic anhydride grafted PP and amino‐functionalized GF. The obtained composite materials were tested from the point of view of composition, morphology, and mechanical properties. It can conclude that the chemical functionalization of the two phases is beneficial from the point of view of compatibility of the phases and consequently higher mechanical properties are obtained. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42163. 相似文献
993.
In this study, the effects of wear behaviours of Al matrix composites reinforced with different B4C rate produced by powder metallurgy method were investigated. Al and B4C powders with purity of 99.9% and sizes of 25–44 µm were prepared as pure Al, 4% B4C/Al, 8% B4C/Al, 12% B4C/Al and 16% B4C/Al. After these prepared mixtures were pressed under 350 MPa, they were sintered for 90 min at 580 °C in atmospheric environment. Microhardness and wear tests of the produced samples were carried out. Wear experiments of these composites were performed with specially manufactured test equipment at different application loads (5 N, 10 N and 15 N), different sliding distances (250 m, 500 m, 750 m and 1000 m) and a constant speed of 0.46 m/s. In addition, optical microscope, SEM, EDS analyses were used to determine the microstructural changes in the worn and unworn surface of the manufactured composite materials. The results of experimental studies show that the increasing the B4C reinforced rate in composites with Al matrix has led to increase of the hardness and to reduce of the wear loss. 相似文献
994.
A vapor generation procedure for the production of volatile species of Au was studied using electrothermal atomic absorption spectrometry (ETAAS). The interference effects of iron in solution and in the gas phase in a quartz T-tube were studied for the first time in detail. A dual vapor generation system was used for a single heated quartz tube atomizer, so that it was possible to study interferences and classify them regarding their origins. Results show that both gas-phase and liquid-phase interferences are present. It was also concluded that since the total interference effect causes the Au signal to be lower as compared to only the presence of gas-phase interactions in the experiment, the net liquid-phase interference from Fe should be suppressed. The method described in this study was used for the determination of gold in an ore reference material, Carlin Ore Mine, for the purpose of demonstrating the ability of the reported method to determine Au without any extraction procedure. 相似文献
995.
Dr. Ioana Nicolau Dr. Niculina D. Hădade Dr. Mihaela Matache Dr. Daniel P. Funeriu 《Chembiochem : a European journal of chemical biology》2023,24(16):e202300157
Synthetic chemical probes are powerful tools for investigating biological processes. They are particularly useful for proteomic studies such as activity-based protein profiling (ABPP). These chemical methods initially used mimics of natural substrates. As the techniques gained prominence, more and more elaborate chemical probes with increased specificity towards given enzyme/protein families and amenability to various reaction conditions were used. Among the chemical probes, peptidyl-epoxysuccinates represent one of the first types of compounds used to investigate the activity of the cysteine protease papain-like family of enzymes. Structurally derived from the natural substrate, a wide body of inhibitors and activity- or affinity-based probes bearing the electrophilic oxirane unit for covalent labeling of active enzymes now exists. Herein, we review the literature regarding the synthetic approaches to epoxysuccinate-based chemical probes together with their reported applications, from biological chemistry and inhibition studies to supramolecular chemistry and the formation of protein arrays. 相似文献
996.
In this study, the effects on the photocatalytic activities of particles after heat treatment has been applied to cobalt ferrite nanoparticles produced by microwave-assisted combustion method were observed. The heat treatment applied to the samples was produced with only the microwave effect, at temperatures ranging from 300 to 1000°C. Thermogravimetric analysis was performed on the precursor sample in air atmosphere. During this analysis, the gases released up to 1200°C were identified with a Fourier-transform infrared (FTIR) spectrometer integrated into a thermogravimetric analysis system. Then, the cobalt ferrite nanoparticles produced with heat treatments applied at various temperatures were used as a photocatalyst to remove the dyestuff content in synthetic wastewaters prepared by using Astrazon Red GTL textile dye by photocatalytic oxidation, and their photocatalytic activities were compared. In these experiments, the operational parameters for photocatalysis processes were applied as 400 rpm for stirring speed, 50 mg/L for initial contaminant concentration, 0.5 g/L for catalyst dosage, 25°C for temperature, and 4400 μW/cm2 for light intensity. As a result of the experiments, it was observed that the crystal structure of the cobalt ferrite nanoparticles produced with the increase of the applied heat treatment temperature improved significantly. The obtained data show a strong relationship between the structural properties of materials and their photocatalytic activities. In addition, it was determined that the dyestuff in the solution was completely degraded in the experiments, and it was determined that all processes were compatible with the pseudo-first-order kinetic model. 相似文献
997.
Effects of electrospraying parameters on deposition of La0.3Sr0.7Fe0.7Cr0.3O3−δ cathode layer on GDC
Sedat Akkurt Can Sındıraç Tuğçe Özmen Egesoy Gökçe Atıcı Elif Erişman Emre Erğen Aligül Büyükaksoy 《International Journal of Applied Ceramic Technology》2023,20(3):1512-1525
High performance in intermediate temperature solid oxide fuel cells requires improvements especially in the microstructure of the cathode layer. New cobalt-free cathode materials are used because cobalt-containing cathodes have higher thermal expansion coefficients, poor long-term chemical stability, and lower mechanical stability. Recently cobalt-free cathodes have been proposed to solve these issues by using deposition methods other than electrospray deposition (ESD). In this study, ESD method is used to develop a cobalt-free cathode layer. The electrolyte layer is gadolinium-doped ceria that is deposited with La0.3Sr0.7Fe0.7 Cr0.3O3−δ (LSFCr) prepared by 2-butoxyethanol and ethylene glycol solvents as opposed to conventional solvents. Experimental ESD parameters are tested at different levels and combinations by applying statistical experimental design methods to optimize the microstructure. Coating deposited as such demonstrated higher electrochemical performance than similar electrodes fabricated by other methods. 相似文献
998.
İremnur Akçakoca Mustafa Karayazıcı Gülsüm Topateş 《Journal of the American Ceramic Society》2023,106(5):3188-3198
The present study aimed to examine the effect of pH and time on the final morphology of calcium borate powders. Primarily, aqueous solutions that mainly consisted of borax and calcium chloride were prepared with five different pH values varying between 2 and 15. Hydrothermal synthesis temperature was determined as 200°C, and four different times from 30 min to 24 h were selected. Phase formation and powder morphology were examined via an X-ray diffractometer and scanning electron microscopy. Fourier transform infrared spectroscopy was used to identify the type of borate groups. Results revealed that pH directly determines the growth mechanism of calcium borate crystals. Lower pH induced nonclassical growth by forming self-assembled nano-plates. Individual, rodlike particles were observed for alkali solution. At weak basic conditions, priceite (4CaO·5B2O3·7H2O) and alkali condition parasibirskite (2CaO·B2O3·H2O) phases were obtained. 相似文献
999.
Journal of Porous Materials - Zeolite coatings were directly crystallized on stainless steel substrates, which included double layer wire mesh cylinders and tubes, by induction heating. X-ray... 相似文献
1000.
Bilen Şentürk Cansu Şahin Ayşe Nur Çetin Ahmet Altındal Ahmet Odabaş Zafer 《Journal of Inorganic and Organometallic Polymers and Materials》2022,32(4):1436-1447
Journal of Inorganic and Organometallic Polymers and Materials - The purpose of this study is to investigate the capability of novel peripheral metal-free and metallo (2H, Fe, Co, Zn) mono nuclear... 相似文献