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Electrical conduction mechanism in plasma polymerized 2‐(diethylamino)ethyl methacrylate thin films
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Thin films of different thicknesses were prepared through glow discharge of 2‐(diethylamino)ethyl methacrylate (DEAEMA) using a capacitively coupled reactor. Current density–voltage (J–V) characteristics for plasma polymerized (PP) DEAEMA thin films of thicknesses 100, 200, 250, and 300 nm in aluminum/PPDEAEMA/aluminum sandwich configuration were studied over the temperature range from 298 to 423 K. J–V curves reveal that in the low‐voltage region, the conduction current obeys Ohm's law while in the high‐voltage region the behavior attributed to be space charge‐limited conduction in PPDEAEMA thin films. The carrier mobility was calculated to be about 6.80 × 10?19 to 2.38 × 10?18 m?2 V?1s?1 for various thicknesses. The free carrier density was found to be about 1.78 × 1023 to 2.04 × 1023 m?3, and the trap density was found to be about 6.93 × 1023 to 15.9 × 1023 m?3 for different thicknesses. The activation energies were estimated to be about 0.005–0.016 eV for 2 and 30 V of PPDEAEMA thin films of different thicknesses. The low‐activation energies indicate that the thermally activated hopping conduction is operative in PPDEAEMA thin films. POLYM. ENG. SCI., 55:2729–2734, 2015. © 2015 Society of Plastics Engineers 相似文献
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Tamanna Azam Jonathan Przybyla-Toscano Florence Vignols Jrmy Couturier Nicolas Rouhier Michael K. Johnson 《International journal of molecular sciences》2020,21(23)
Iron-sulfur (Fe-S) proteins are crucial for many cellular functions, particularly those involving electron transfer and metabolic reactions. An essential monothiol glutaredoxin GRXS15 plays a key role in the maturation of plant mitochondrial Fe-S proteins. However, its specific molecular function is not clear, and may be different from that of the better characterized yeast and human orthologs, based on known properties. Hence, we report here a detailed characterization of the interactions between Arabidopsis thaliana GRXS15 and ISCA proteins using both in vivo and in vitro approaches. Yeast two-hybrid and bimolecular fluorescence complementation experiments demonstrated that GRXS15 interacts with each of the three plant mitochondrial ISCA1a/1b/2 proteins. UV-visible absorption/CD and resonance Raman spectroscopy demonstrated that coexpression of ISCA1a and ISCA2 resulted in samples with one [2Fe-2S]2+ cluster per ISCA1a/2 heterodimer, but cluster reconstitution using as-purified [2Fe-2S]-ISCA1a/2 resulted in a [4Fe-4S]2+ cluster-bound ISCA1a/2 heterodimer. Cluster transfer reactions monitored by UV-visible absorption and CD spectroscopy demonstrated that [2Fe-2S]-GRXS15 mediates [2Fe-2S]2+ cluster assembly on mitochondrial ferredoxin and [4Fe-4S]2+ cluster assembly on the ISCA1a/2 heterodimer in the presence of excess glutathione. This suggests that ISCA1a/2 is an assembler of [4Fe-4S]2+ clusters, via two-electron reductive coupling of two [2Fe-2S]2+ clusters. Overall, the results provide new insights into the roles of GRXS15 and ISCA1a/2 in effecting [2Fe-2S]2+ to [4Fe-4S]2+ cluster conversions for the maturation of client [4Fe-4S] cluster-containing proteins in plants. 相似文献
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The order‐preserving pattern matching problem has gained attention in recent years. It consists in finding all substrings in the text, which have the same length and relative order as the input pattern. Typically, the text and the pattern consist of numbers. Since recent times, there has been a tendency to utilize the ability of the word RAM model to increase the efficiency of string matching algorithms. This model works on computer words, reading and processing blocks of characters at once, so that usual arithmetic and logic operations on words can be performed in one unit of time. In this paper, we present a fast order‐preserving pattern matching algorithm, which uses specialized word‐size packed string matching instructions, grounded on the single instruction multiple data instruction set architecture. We show with experimental results that the new proposed algorithm is more efficient than the previous solutions. ©2016 The Authors. Software: Practice and Experience Published by John Wiley & Sons Ltd. 相似文献
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Poly (acrylamide‐co‐methyl methacrylate) hydrogels of different ratios were prepared by using chemical and physical crosslinks to study the effect of nature of crosslinks on swelling behavior of hydrogels. The chemically crosslinked gels were prepared by using NN′‐methylene bis acrylamide, while physically crosslinked hydrogels were prepared by precipitation polymerization method, using dioxane as solvent. Detailed swelling kinetics such as swelling ratio, transport exponent n, diffusion coefficient D and the effect of pH on equilibrium swelling studies. The study revealed that the nature of crosslinks alter the swelling characteristics of the hydrogel. In chemically crosslinked hydrogels the water transport is Fickian in nature, while in the case of the physically crosslinked hydrogels the water transport mechanism is anomalous indicating major change in relaxation mechanism due to nature of crosslinks. The results also indicate that with increasing acrylamide content the swelling ratio of the hydrogels were also increased, but the transport exponent n remains nearly constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 779–786, 2003 相似文献
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M. Asif M. Tariq S. A. Tamanna M. U. Ahmad 《European Journal of Lipid Science and Technology》1981,83(8):323-324
The content and composition of sterols and fatty acids of Delphinium denudatum roots, which are used in the Indian Unani system of medicine, were determined. The sterols were composed almost entirely of campesterol, stigmasterol and sitosterol. Trace amounts of cholesterol and Δ5-avenasterol were also detected. Characteristic higher plant fatty acids were also present. 相似文献
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M. Kuppan S. Kaleemulla N. Madhusudhana Rao N. Sai Krishna M. Rigana Begam D. Sreekantha Reddy 《Journal of Superconductivity and Novel Magnetism》2014,27(5):1315-1321
Iron-doped SnO2 diluted magnetic semiconducting powders (Sn1?x Fe x O2, x=0.00, 0.03, 0.05, 0.07, 0.10, and 0.15) were synthesized by a simple solid state reaction followed by vacuum annealing and studied the effect of Fe dopant concentrations on structural, optical, and magnetic properties of the synthesized samples. From the X-ray diffraction, it was confirmed that the samples prepared at lower dopant concentrations were tetragonal in structure whereas the samples prepared at higher dopant concentration exhibited orthorhombic SnO and Fe2O3 phases along with tetragonal SnO2 structure. FT-IR spectrum has been used to confirm the formation of Sn–O bond. The optical band gap of the Sn1?x Fe x O2 powders was increased from 3.6 eV to 3.7 eV with increase of dopant concentration. Raman spectroscopy measurement revealed that the broadening of the most intense Raman peak observed at 630 cm?1 with Fe doping, conforming that the Fe ions are substituted at the Sn sites in the SnO2 lattice. Vibrating sample magnetometer measurements confirmed that the Sn1?x Fe x O2 powders were ferromagnetic at room temperature. 相似文献
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L Shamsuddin S Rouf JH Khan S Tamanna AZ Hussain AK Samsuddin 《Canadian Metallurgical Quarterly》1998,24(2):43-48
This clinical trial was conducted to compare the anticonvulsant response of magnesium sulphate and diazepam in the management of eclampsia. The study was carried out at the eclampsia unit of Dhaka Medical College Hospital during the period from October, 1995 to January, 1996. Two hundred consecutive admitted patients were recruited for the study and randomly assigned to two treatment groups: magnesium sulphate and diazepam. One hundred patients received injection magnesium sulphate and another one hundred received injection diazepam. All patients of both the group were matched for baseline characteristics. Convulsion was controlled in 95% of the patients of magnesium sulphate group and 74% of the patients of diazepam group (p < .0005). The mean controlling time is also significantly lower in magnesium sulphate group than diazepam group (8.50 hours vs 9.39 hours). Patients of magnesium sulphate group regain consciousness much earlier (mean time 20.62 hrs.) than the patients of diazepam group (mean time 40.62 hrs.). No significant difference was observed in controlling blood pressure and foetal outcome. The study finding shows that magnesium sulphate has some advantage over diazepam in controlling convulsion and regaining consciousness. If magnesium sulphate can be made available in the market by local production it may be recommended to use this drug in the primary health care without any hazzard before referring to other hospital. 相似文献
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Thickness dependence of ac electrical conductivity and dielectric behavior of plasma polymerized 1, 1, 3, 3–tetramethoxypropane thin films
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AC electrical conductivity (σac), dielectric constant (?′), and dielectric loss tangent (tan δ) of plasma polymerized 1, 1, 3, 3‐tetramethoxy‐propane (PPTMP) thin films of thicknesses 100, 150, and 200 nm prepared by plasma polymerization technique using a capacitively coupled glow discharge reactor have been investigated in the frequency range of 30–106 Hz. It is observed that σac increases as frequency increases with a higher slope in the medium frequency (<105Hz) region in the PPTMP thin films of three thicknesses. These observations suggest that the conduction may be dominated by hopping of carriers between the localized states. The general trend of ?′ is to increase with increasing thickness, ?′ remains independent of frequency upto about 104Hz and then falls rapidly. The dependence of tanδ with frequency for PPTMP thin films of different thicknesses showed small relaxation peak at the very low frequencies (<102Hz) and then it decreases slightly with a broad minimum at 103 Hz and again increases. Cole–Cole plot reveals that Debye type of mechanism is operative in the experimental frequency range. POLYM. ENG. SCI., 58:1342–1345, 2018. © 2017 Society of Plastics Engineers 相似文献