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141.
Randić M 《Chemical reviews》2003,103(9):3449-3605
142.
A series of Ni + WC composite coatings were obtained by electrodeposition on a rotating disc electrode (RDE) from a commercially available Watts bath containing additives for brightness and smoothing and insoluble WC particles, using either constant or pulsating current. It was shown that the amount of WC embedded in the coating could vary from a few percent to over 80% depending on the rotation rate and the current density of deposition. Higher amounts (over 50 mass%) of embedded WC particles could be obtained only at rotation rates higher than 2000 rpm. It was also shown that the concentration of insoluble WC particles in the Watts bath has no significant influence on the amount of WC embedded in the coating, enabling the use of dilute mixtures (2 mass% of WC in the solution). At higher amounts of embedded WC particles, rough deposits were obtained with the WC particles being mostly incorporated in agglomerates of different sizes (from about 50 m to about 100 m). It was also shown that under the same conditions of electrodeposition, higher amounts of embedded WC particles could be obtained from solutions containing smaller particles. 相似文献
143.
Igor Jerković Marina Rajić Zvonimir Marijanović Mate Bilić Stela Jokić 《分离科学与技术》2016,51(18):2925-2931
Supercritical (SC) CO2 extraction of dried Immortelle flowers was performed at different process parameters. The optimal extraction conditions related to the yield were determined by response surface methodology (yield 4.09% at 20 MPa and 52°C). The extracts were analyzed by GC-MS and tremetone derivatives dominated: bitalin A, 12-acetoxytremetone, gnaphaliol, 1-[2-(2-methyl-2,3-dihydroxypropyl)-2,3-dihydro-1-benzofuran-5-yl]ethanone, isobutyl bitalin A, and 1-[2-(acetylprop-1-en-2-yl)-3-hydroxy-2,3-dihydro-1-benzofuran-5-yl]ethanone. Striking differences were found among the essential oil and SC-CO2 extracts composition. The major oil compounds were γ-curcumene, α-pinene, β-selinene, α-selinene, and limonene. Mono- and sesquiterpene were found among minor constituents of the extracts. Neryl acetate was present in the extracts and essential oil. 相似文献
144.
Marija Prekajski Đorđević Jelena Maletaškić Nadežda Stanković Biljana Babić Katsumi Yoshida Toyohiko Yano Branko Matović 《Ceramics International》2018,44(2):1771-1777
Hydroxyapatite was used as the inert matrix for in-situ immobilization of strontium (Sr) radioactive isotopes at room temperature. A nano-emulsification method was applied to synthesize Sr-substituted calcium hydroxyapatite (Ca1?xSrx)10(PO4)6(OH)2. The concentration of incorporated Sr was in the range of 0 ≤ x ≤ 1. Immobilization of Sr was evaluated using a stable isotope instead of radioactive isotope. The effect of strontium concentration on the crystal structure was studied and the results have showed that in the whole concentration range, Sr forms solid solutions with the host hydroxyapatite crystal structure. Powders comprised of nanometre sized particles were obtained and their properties, such as crystallite and particle size, changes in lattice parameters as function of dopant content and thermal stability, were further examined. It was found that the crystal structure of obtained powders is thermally stable at high temperatures. No secondary phases were formed in as-prepared powders or during calcination. The results in this study showed that nano-emulsion strategy provides a simple pathway for synthesis of a single-phase Sr-substituted hydroxyapatite, which can be used for immobilization of Sr radioactive isotopes. 相似文献
145.
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147.
Jian Hong Xiao‐Qin Yang Xianmei Wan Zhifeng Zheng Zoran S Petrović 《Polymer International》2017,66(1):126-132
Rubber seed oil having high free fatty acid content and high unsaturation was used to obtain high quality polyurethane resins through epoxidation and ring opening with methanol and free fatty acids. Two polyols prepared with free fatty acids and without were cured with modified methylene diphenyl diisocyanate to obtain strong, high modulus glassy polyurethanes. The effect of structure on thermal and mechanical properties was analyzed. This showed that the polyol with free fatty acid utilized to obtain a branched structure gave superior crosslinking density and mechanical properties. © 2016 Society of Chemical Industry 相似文献
148.
Mario Ščetar Mia Kurek Anet Režek Jambrak Frédéric Debeaufort Kata Galić 《Polymer International》2017,66(11):1572-1578
Investigation was focused on the impact of high power ultrasound (HPUS), also called thermosonication, on the oxygen permeation properties (permeability, solubility and diffusion coefficients) of barrier films aimed for food packaging. For this purpose, biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) were used. The physical–chemical profile of the samples was determined using goniometry. There is a significant impact only of extreme HPUS conditions (the longest time and the highest amplitude) on the permeability, solubility and diffusion coefficients of oxygen through the BOPP films. The highest influence on the oxygen permeability in both investigated BOPP samples involved an HPUS with an amplitude of 100% during a 6 min treatment. However, BOPP samples showed different sensitivities at lower HPUS treatments. © 2017 Society of Chemical Industry 相似文献
149.
Petr Ryšánek Marek Malý Pavla Čapková Martin Kormunda Zdeňka Kolská Milan Gryndler Ondřej Novák Lucie Hocelíková Lukáš Bystrianský Marcela Munzarová 《Journal of Polymer Research》2017,24(11):208
Antibacterial nylon 6 (PA6) nanofibers have been prepared in one-step procedure using Nanospider technology. Chlorhexidine (CHX), 1-dodecyltrimethylamonium bromide (DTAB) and benzyltrimethylamonium bromide (BTAB) have been used as antibacterial agents. Samples were characterized by a series of analytical and testing methods to investigate the surface chemistry, zeta potential, structure, morphology, phase composition, mechanical properties and antibacterial activity. Experimental characterization has been combined with molecular modeling to analyze the interaction of nanofibers with modifying molecules for better understanding the effect of nanofibers modification on their properties. Antibacterial modification of PA6 led to significant changes of zeta potential (from -31 mV for PA 6 up to -49 mV for PA6/BTAB), changes in phase composition (decrease of alpha phase content and increase of gamma phase content for PA6/BTAB and PA6/CHX) and to significant increase of fiber diameter for PA6/BTAB. Antibacterial modification resulted in the straightening of nanofibers and to higher permeability of nanofiber textile for all investigated samples. Tensile tests showed the the increase of Young modulus for all the investigated samples. All the modified samples: PA6/DTAB, PA6/BTAB and PA6/CHX exhibit good antibacterial activity. 相似文献
150.
ABSTRACT Simulation results for convective drying processes in cross-flow packed bed grain dryers are discussed in this article. A mathematical model developed in order to enable easier design of convective dryers and optimization of operating conditions for agricultural materials (wheat, corn, sunflower seed, etc.) is used in the study. On the basis of calculated values of the state variables of the gas phase and the solids, a clear image of the process itself can be obtained, as well as an overview of advantages and disadvantages of a specific design, supporting and facilitating decisions about the choice of dryer type and operating scheme. The case of double passing of drying agent, with and without additional heating, for a cross-flow continuous dryer, as well as the case of different materials processed in a series of cross-flow batch dryers, is analyzed. 相似文献