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1.
A number of potential causes for the observed roughness of the side-walls in anisotropically etched cavities for silicon pressure sensors are investigated. Wafer stress is found to be the primary cause, possibly enhanced by the presence of precipitates from which etching irregularities may be initiated. 相似文献
2.
Aggregates were formed by heating mixtures of whey protein isolate (WPI) and pure κ-casein or sodium caseinate at pH 7 and 0.1 M NaCl. The aggregates were characterized by static and dynamic light scattering and size exclusion chromatography. After extensive heat-treatment at 80 °C for 24 h, almost all whey proteins and κ-casein formed mixed aggregates, but a large proportion of the sodium caseinate did not aggregate. At a given WPI concentration the size of the aggregates decreased with increasing κ-casein or sodium caseinate concentration, but the overall self-similar structure of the aggregates was the same. The presence of κ-casein or caseinate therefore inhibited growth of the heat-induced whey protein aggregates. The results were discussed relative to the reported chaperone-like activity of casein molecules towards heat aggregation of globular proteins. 相似文献
3.
John M. Kayembe Merveille I. Bokwokwo Periyasamy Sivalingam Patience Ngelinkoto Jean‐Paul Otamonga Crispin K. Mulaji Josu I. Mubedi John Pot 《Water and Environment Journal》2020,34(2):180-188
The objective of the present study was to assess the status of surface sediments from Funa River. Sediment samples were characterized for physicochemical parameters, including grain size, organic matter and toxic metals. The result revealed high metal concentrations in river sediments, reaching values of 154.19, 186.00, 1105.34, 3.69, 548.02 and 5.45 mg/kg for Cr, Cu, Zn, Cd, Pb and Hg, respectively. A strong correlation was observed between analysed metals and organic matter suggesting that these contaminants could have originated from common sources with a similar transport pathway. Based on the Sediment Quality Guidelines for the Protection of Aquatic Life, Funa River is considered as highly polluted with toxic metals indicating the potential environmental and human health risk. The results of this research represent a useful tool to assess the sediment quality of urban river receiving system which can be applied to similar environment. 相似文献
4.
Nono Jean Hubert ;Bikele Mama Desire ;Ghogomu Numbonui Julius ;Younang Elie ;Mbaze Meva'a Luc Leonard ;Lissouck Daniel ;Zobo Mfomo Joseph ;Shridhar Ramchandra Gadre 《化学与化工:英文版》2014,(12):1109-1124
In this article, we have performed B3LYP/6-31+G(d) calculations of geometrical and reaction enthalpies of antioxidant mechanisms for ADPHT 1-4 (3-alkyl-4-phenylacetylamino-lH-1,2,4-triazol-5-ones) and its derivatives: HAT (hydrogen atom transfer), SET-PT (single electron transfer-proton transfer) and SPLET (sequential proton-loss electron transfer) were investigated in gas and solution-phases. Solvent contribution to enthalpies was computed employing integral equation formalism IEF-PCM (integral equation formalism method) method. It turned out that the lowest BDEs (bond dissociation energies) is obtained for C-H bonds due to captodative effect in various media. Results indicate that HAT mechanism represents the most anticipated process in gas-phase from thermodynamic point of view. But, the SPLET represents the thermodynamically preferred reaction pathway in solvents (2-propanol, acetonitrile, DMF (N,N-dimethylformamide) and water). The authors showed that bond dissociation energies, IP (ionization potential) and PA (proton affinity) are sufficient to evaluate the thermodynamically preferred mechanism. 相似文献
5.
Poly(tetrafluoroethylene) and a fluoroethylene copolymer were surface treated with a 2.45‐GHz microwave plasma to enhance their adhesion to a vinylester thermoset. The plasmas were generated with an inert gas (Ar) and with reactive gases (H2, O2, and N2). The lap‐joint shear stress was measured on fluoropolymer samples glued with the vinylester. In general, the stress at failure increased with increasing plasma‐energy dose. The H2 plasma yielded the best adhesion, and X‐ray photoelectron spectroscopy revealed that it yielded the highest degree of defluorination of the fluoropolymer surface. The defluorination efficiency declined in the order H2, Ar, O2, and N2. Contact angle measurements and scanning electron microscopy revealed that the surface roughness of the fluoropolymer depended on the rate of achieving the target energy dose. High power led to a smoother surface, probably because of a greater increase in temperature and partial melting. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 838–842, 2005 相似文献
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7.
Nono Darsono Sung-Wook Kwon Dang-Hyok Yoon Jaemyung Kim Heesung Moon Seoung-Uk Park 《Journal of Materials Science: Materials in Electronics》2008,19(1):17-23
Field emission properties of screen-printed carbon nanotube (CNT) pastes were investigated by design of experiments (DOE)
using three, two-level, input factors. Characterization showed that the multi-walled carbon nanotubes (MWNTs) with a diameter
of approximately 5 nm containing 5 wt. % of carbonaceous impurities were almost completely burnt out after heating to 600°C
in air, while 96% of the sample remained even up to 800°C in a nitrogen atmosphere. Experimental measurements using a diode
structure for eight sample groups revealed an emission current density of 52–87 μA/cm2 in an electric field of 5 V/μA and a field enhancement factor of 12,079–16,922, assuming the work function of MWNTs to be 5 eV, thereby demonstrating superior
emission properties with the sample containing a larger amount of MWNTs. A long-term, 110-h reliability test showed a stable
emission property with a half-life of 6,000 h. 相似文献
8.
Mixtures of the polysaccharide κ-carrageenan (KC) and caseinate proteins (SC) from milk were investigated at pH 7 in aqueous solution using confocal scanning laser microscopy and light scattering. Phase separation was observed at higher concentrations and the phase diagram was established. In the mixtures SC was observed to form large aggregates mediated by a relatively small amount of KC. At small KC concentrations the aggregates were initially relatively small and could be characterized by light scattering. At higher KC concentrations or on longer storage at 20 °C, dense clusters with a radius of a few microns were formed that slowly precipitated. The fraction of precipitated protein increased linearly with increasing KC concentration, but was independent of the protein concentration. It increased with decreasing pH from about 20% at pH 8 to 100% at pH 5. 相似文献
9.
Nono Darsono Parlindungan Yonathan Dang-Hyok Yoon Jaemyung Kim Yoonjin Kim 《Materials Chemistry and Physics》2008,110(2-3):363-369
Multi-walled carbon nanotubes (MWNTs) were high-energy milled for 2 h in texanol after a polycarboxylic acid polymeric dispersant had been added in order to enhance the dispersion. The degree of MWNT dispersion was significantly enhanced by high-energy milling compared to the intact sample, which increased the density of surface-exposed MWNTs with a screen-printed paste. However, the emission properties of high-energy milled MWNTs did not show such a high emission current density relative to their increased surface-exposed density. Further investigation using Raman spectroscopy and X-ray diffraction evidenced the milling-induced MWNT damage, which explained the relatively lower emission current density of high-energy milled MWNTs. 相似文献
10.
Yvette Jiokap Nono Franois Giroux Bernard Cuq Anne-Lucie Raoult-Wack 《Journal of food engineering》2001,50(4):203-210
The work presented here is a study aiming at the control and checking of dewatering and impregnation soaking process (DISP). The studies are carried out using an automatic experimental system. Apples of the “Golden” variety are used exclusively. Two kinds of agitation system are studied; mechanical agitation using a vertical screw without an end, and hydraulic agitation. There is hardly any difference between the two kinds of agitation; parameter variations are almost the same. These results are compared with those obtained in agitated thermostated water-bath system and they show that mass transfers are better on the experimental system than with the water-bath system. Temperature influences were studied for the agitated thermostated water-bath system only. They show that the increase of temperature favours water loss and sugar intake. We have shown that during experiments with old syrup, only the conductivity of syrup is higher but kinetics of water loss, solute intake and weight reduction are not significantly affected. 相似文献