Particle Adhesion to Drops

The adhesion of spheroidal particles to spherical drops is calculated and discussed in terms of an equilibrium-penetration index. The present study emphasizes the case of particles that are sufficiently large to affect the drop volume upon penetration. It is shown that the more elongated the particles, the steeper the dependence of the penetration index on the contact angle. The effect of line tension on nanoscale particles is considered. Positive line tensions increase the steepness of the dependence of penetration index on contact angle whereas negative line tensions decrease this dependence. In addition, the energy barrier caused by positive line tensions is presented and discussed.     

Blue pigments based on CoxZn1−xAl2O4 spinels synthesized by the polymeric precursor method

The Co_xZn_1?xAl₂O₄ system (x = 0; 0.1; 0.3; 0.5; 0.7; 0.9 and 1) was synthesized by the polymeric precursor method and characterized by the techniques XRD, TG-DTA, IR, UV–vis and colorimetry. The XRD patterns displayed the characteristic peaks of the spinel structure and a good crystallinity. The DTA curves showed an exothermic peak corresponding to the enthalpy of the transition taking place at about 700 °C. The infrared spectra displayed vibrations at about 650, 550, 540, 520, 500, 490 cm^?1, which were ascribed to the spinel structure. The UV–vis spectra presented three bands at 550, 580 and 620 nm attributed to the Co²⁺ spin transitions in tetrahedral sites. The colorimetric data point out the formation of blue pigments, corresponding to highly negative values of b¹. The lightness, coordinate L¹, increases with the heat treatment temperature. These facts reveal that Co_xZn_1?xAl₂O₄ is a promising system that can be employed to obtain ceramic blue pigments.     

Cardioinotropic Effects in Subchronic Intoxication of Rats with Lead and/or Cadmium Oxide Nanoparticles

Subchronic intoxication was induced in outbred male rats by repeated intraperitoneal injections with lead oxide (PbO) and/or cadmium oxide (CdO) nanoparticles (NPs) 3 times a week during 6 weeks for the purpose of examining its effects on the contractile characteristics of isolated right ventricle trabeculae and papillary muscles in isometric and afterload contractions. Isolated and combined intoxication with these NPs was observed to reduce the mechanical work produced by both types of myocardial preparation. Using the in vitro motility assay, we showed that the sliding velocity of regulated thin filaments drops under both isolated and combined intoxication with CdO–NP and PbO–NP. These results correlate with a shift in the expression of myosin heavy chain (MHC) isoforms towards slowly cycling β–MHC. The type of CdO–NP + PbO–NP combined cardiotoxicity depends on the effect of the toxic impact, the extent of this effect, the ratio of toxicant doses, and the degree of stretching of cardiomyocytes and muscle type studied. Some indices of combined Pb–NP and CdO–NP cardiotoxicity and general toxicity (genotoxicity included) became fully or partly normalized if intoxication developed against background administration of a bioprotective complex.     

Effect of sampling density on the measurement of stream condition indicators in two lowland Australian streams

There is widespread application of indicators to the assessment of environmental condition of streams. These indicators are intended for use by managers in making various comparative and absolute assessments and often have a role in resource allocation and performance assessment. Therefore, the problem of formally defining confidence in the results is important but difficult because the sampling strategies used are commonly based on a compromise between the requirements of statistical rigour and the pragmatic issues of access and resources. It is rare to see this compromise explicitly considered and consequently there is seldom quantification of the uncertainty that could affect the confidence a manager has in an indicator. In this paper, we present a method for quantitatively assessing the tradeoffs between sampling density and uncertainty in meeting various monitoring objectives. Assessments using judgement‐based representative reaches are shown to be unreliable; instead a sampling approach is recommended based on the random selection of measuring sites. A detailed dataset was collected along two streams in Victoria, Australia, and the effect of sampling density was assessed by subsampling from this dataset with precision related to the number of sites assessed per reach length and the intensity of the sampling at each site. The sampling scheme to achieve a given precision is shown to depend on the monitoring objective. In particular, three objectives were considered: (1) making a baseline assessment of current condition; (2) change detection; and (3) detection of a critical threshold in condition. Change detection is shown to be more demanding than assessing baseline condition with additional sampling effort required to achieve the same precision. Sampling to detect a critical threshold depends on nominating acceptable values of Type I and II error and the size of the effect to be detected. Copyright © 2006 John Wiley & Sons, Ltd.     

Intermetallide catalysts for hydrogen storage on the basis of reversible aromatics hydrogenation/dehydrogenation reactions

New efficient intermetallide catalysts for hydrogen storage in reversible processes of aromatics hydrogenation and naphthene dehydrogenation were studied. These catalysts provide an enhanced activity in the dehydrogenation of saturated organic molecules, with no side reactions like cracking, hydrogenolysis, ring opening, or coke formation occurring on these catalysts. The use of intermetallides provides some hydrogen storage capacity in the low-temperature region, while their catalytic activity in the dehydrogenation affords the hydrogen supply in the high-temperature range.     

火山灰对富有机质页岩形成的影响——以西西伯利亚盆地中生界巴热诺夫组为例

西西伯利亚盆地上侏罗统-下白垩统巴热诺夫组硅质-钙质富有机质泥页岩总有机碳(TOC)含量高且有机质成熟度适中,是俄罗斯目前页岩油的勘探首选目的层系。近年研究表明,该套富有机质页岩层段发育数套厘米-毫米级的火山灰夹层,具黄色荧光,岩心薄片见大量沸石等火山灰蚀变矿物,使该区火山灰与富有机质形成的相互关系引起关注。以该盆地的巴热诺夫组为例,介绍了火山灰对该区富有机质页岩形成的影响。巴热诺夫组的地质-地球化学分析表明,在火山灰发育同期沉积的富有机质层段中不仅硅、磷等营养元素含量高,而且钡、锰、钼、铀等藻类繁殖催化元素含量也高,推测火山灰携带物质促进了巴热诺夫页岩沉积时期古生物的大量繁殖甚至爆发,为富有机质的形成奠定了物质基础;同时,在火山灰发育层段之上的富有机质泥页岩中大量发育草莓状黄铁矿,且呈层状分布,Co/Ni比值小于1,S/Fe比值偏高,指示火山灰喷发之后形成缺氧的强还原环境,有利于泥页岩中有机质的保存;火山灰发育井区TOC含量高(多>7%),有机质成熟度与邻近火山灰不发育区相比偏高(R_o=0.7%～1.1%),生烃潜力高且已达到生油高峰,推测可能火山灰携带的...     

The multiscale hermite transform for local orientation analysis.

The efficient representation of local differential structure at various resolutions has been a matter of great interest for adaptive image processing and computer vision tasks. In this paper, we derive a multiscale model to represent natural images based on the scale-space representation: a model that has an inspiration in the human visual system. We first derive the one-dimensional case and then extend the results to two and three dimensions. The operators obtained for analysis and synthesis stages are derivatives of the Gaussian smoothing kernel, so that, for the two-dimensional case, we can represent them either in a rotated coordinate system or in terms of directional derivatives. The method to perform the rotation is efficient because it is implemented by means of the application of the so-called generalized binomial filters. Such a family of discrete sequences fulfills a number of properties that allows estimating the local orientation for several image structures. We also define the discrete counterpart in which the coordinate normalization of the continuous case is approximated as a subsampling of the discrete domain.     

Dietary vitamin E effect on color stability and sensory assessment of spoilage in three beef muscles

Effects of dietary vitamin E supplementation (1204 IU/head/day) for 122 days on color stability and microbial load on beef m. longissimus lumborum (LL), m. gluteus medius (GM) and m. psoas major (PM) were studied by subjective and objective evaluation. Color stability of these muscles followed the order LL > GM > PM (p < 0.05). Vitamin E-treated LL, GM and PM showed less metmyoglobin formation, higher a^* values and lower hue angle values than controls during storage at 4 °C (p < 0.05). Sensory evaluation demonstrated that panelists preferred the appearance of vitamin E-treated LL, GM and PM beef steaks. Vitamin E supplementation did not affect total microbial load on LL, PM and GM and did not influence panelists' olfactory assessment of microbial spoilage of beef. Endogenous -tocopherol concentration and lipid stability of microsomal fractions of LL, GM and PM were greater (p < 0.05) in vitamin E-treated muscles relative to controls. There was no muscle effect on the pro-oxidant activity of microsomes towards oxymyoglobin oxidation (p > 0.05). Oxymyoglobin stability was greater in the presence of microsomal fractions obtained from vitamin E-treated muscle than in those from controls. Dietary vitamin E supplementation delayed oxymyoglobin oxidation in LL, PM and GM muscle and increased the color shelf-life of these muscles without affecting total microbial load.     

Towards the integration of dark- and photo-fermentative waste treatment. 2. Optimization of starch-dependent fermentative hydrogen production

Eight natural microbial consortia collected from different sites were tested for dark, hydrogen production during starch degradation. The most active consortium was from silo pit liquid under mesophilic (37 °C) conditions. The fermentation medium for this consortium was optimized (Fe, NH₄⁺, phosphates, peptone, and starch content) for both dark fermentation and for subsequent purple photosynthetic bacterial H₂ photoproduction [Laurinavichene TV, Tekucheva DN, Laurinavichius KS, Ghirardi ML, Seibert M, Tsygankov AA. Towards the integration of dark and photo fermentative waste treatment. 1. Hydrogen photoproduction by purple bacterium Rhodobacter capsulatus using potential products of starch fermentation. Int J Hydrogen Energy 2008;33(23):7020–26], in the presence of the spent dark, fermentation effluent. The addition of Zn (10 mg L⁻¹), as a methanogenesis inhibitor that does not inhibit purple bacteria at this concentration, also did not inhibit dark, fermentative H₂ production. The influence of various fermentation end products at different concentrations (up to 30 g L⁻¹) on dark, H₂ production was also examined. Added lactate stimulated, but added isobutyrate and butanol strongly inhibited gas production. Under optimal conditions the fermentation of starch (30 g L⁻¹) resulted in 5.7 L H₂ L⁻¹ of culture (1.6 mol H₂ per mole of hexose) with the co-production mainly of butyrate and acetate.