Some practical aspects connected with the presence of calcium in soybean oils

Presence of calcium in crude and degummed soybean oils prevents complete elimination of phosphatides by hydration and enhances the formation of heavy precipitates. They block industrial centrifuges at the later stages of the refining processes. Industrially extracted degummed soybean oils contain appreciable amounts of calcium (ca. 100 ppm) and its source was traced to the processed soybeans. Various pre-extraction treatments of the soybeans in industry augment the calcium content in the oils, since crude Soxhlet-extracted soybean oils contained only 15 ppm calcium. Additions at the alkali-refining stages of EDTA or of polyphosphate, to stabilize aqueous suspensions which also contain calcium salts, are suggested as a partial remedy to the frequent blocking of the centrifuges.     

An Experimental Approach for the Characterisation of Rigid Porous Media and Unsaturated Conductivity Relations

A laboratory procedure for the characterisation of rigid, porous media is developed and tested. The overall objective of the characterisation is to provide a basis for the choice of a relevant unsaturated conductivity relation. With the proposed procedure, the porous materials are characterised through hydraulic conductivity measurements, saturation-pressure measurements, porosity measurements and air entry pressure measurements. The measurements were conducted using water and a selected non-aqueous phase liquid (n-decane), and two types of homogeneous, rigid porous media of different origin (fritted glass samples with guaranteed homogeneity by the manufacturer, and chalk). The laboratory method successfully characterised the fritted glass samples as homogeneous on basis of calculated tortuosity values, measured bubble pressures and measured pore-size density curves. The contact angle between the liquid and the solid had negligible impact when comparing the drainage of water with the drainage of n-decane, and also when comparingn -decane drainage in dry porous media withn -decane drainage in media where a film of water separated then -decane from the pore wall. Also, the differences in saturated conductivities between n-decane and water in both samples of chalk and fritted glass were well predicted on basis of differences in density and viscosity of the liquids. The laboratory procedure was furthermore used for characterisation of the pore space available for non-aqueous liquid flow in partially water-saturated porous media. Then -decane conductivities in the fritted glass samples partially saturated with water were considerably lower than the n-decane conductivities in the dry fritted glass samples.     

External sorting on flash storage: reducing cell wearing and increasing efficiency by avoiding intermediate writes

This paper studies the problem of how to conduct external sorting on flash drives while avoiding intermediate writes to the disk. The focus is on sort in portable electronic devices, where relations are only larger than the main memory by a small factor, and on sort as part of distributed processes where relations are frequently partially sorted. In such cases, sort algorithms that refrain from writing intermediate results to the disk have three advantages over algorithms that perform intermediate writes. First, on devices in which read operations are much faster than writes, such methods are efficient and frequently outperform Merge Sort. Secondly, they reduce flash cell degradation caused by writes. Thirdly, they can be used in cases where there is not enough disk space for the intermediate results. Novel sort algorithms that avoid intermediate writes to the disk are presented. An experimental evaluation, on different flash storage devices, shows that in many cases the new algorithms can extend the lifespan of the devices by avoiding unnecessary writes to the disk, while maintaining efficiency, in comparison with Merge Sort.     

Energy Filtering of Charge Carriers: Current Trends,Challenges, and Prospects for Thermoelectric Materials

Exhaustive attempts are made in recent decades to improve the performance of thermoelectric materials that are utilized for waste heat‐to‐electricity conversion. Energy filtering of charge carriers is directed toward enhancing the material thermopower. This paper focuses on the theoretical concepts, experimental evidence, and the authors' view of energy filtering in the context of thermoelectric materials. Recent studies suggest that not all materials experience this effect with the same intensity. Although this effect theoretically demonstrates improvement of the thermopower, applying it poses certain constraints, which demands further research. Predicated on data documented in literature, the unusual dependence of the thermopower and conductivity upon charge carrier concentrations can be altered through the energy filtering approach. Upon surmounting the physical constraints discussed in this article, thermoelectric materials research may gain a new direction to enhance the power factor and thermoelectric figure of merit.     

Nanoparticles of CdCl2 with closed cage structures

Nanoparticles of various layered compounds having a closed cage or nanotubular structure, designated also inorganic fullerene-like (IF) materials, have been reported in the past. In this work IF-CdCl₂ nanoparticles were synthesized by two methods. In one technique, a high temperature evaporation and subsequent condensation of dried cadmium chloride powder was used. In the other method, electron beam irradiation of the source powder led to its recrystallization into closed nanoparticles with a nonhollow core. The two methods are shown to produce nanoparticles of different topologies. While mostly spherical nested structures are obtained from the high temperature process, polyhedra with hexagonal or elongated rectangular characters are obtained by the electron beam induced process. The analysis also shows that, while the source (dried) powder is orthorhombic cadmium chloride monohydrate, the crystallized IF cage consists of the anhydrous 3R polytype which is not stable as bulk material in ambient atmosphere. Consistent with previous observations, this study shows that the seamless structure of the IF materials can stabilize phases, which are otherwise unstable in ambient conditions.     

On the Effective Deployment of Functional Formal Verification

We examine IBM's exploitation of formal verification using RuleBase—a formal verification tool developed by the IBM Haifa Research Laboratory. The goal of the paper is methodological. We identify an integrated methodology for the deployment of formal verification which involves three complementary modes: architectural verification, block-level verification, and design exploration.     

Visually evoked cerebral vasomotor response in smoking and nonsmoking young adults, investigated by functional transcranial Doppler

Smoking has been known to cause endothelial dysfunction and is an important risk factor for ischemic stroke. In our study we investigated whether chronic cigarette smoking affects the cerebral blood flow velocity response to a physiological, visual stimulus. By using a visual cortex stimulation paradigm, the flow velocity response in the posterior cerebral arteries (PCA) was measured bilaterally, in 32 young healthy adults (16 smokers, 16 nonsmokers). The stimulation protocol consisted of 10 cycles with a resting phase of 20 s and a stimulating phase of 40 s for each cycle. Besides functional transcranial Doppler (TCD), laboratory tests and measurement of intima-media-thickness (IMT) were also performed. Repeated-measure analysis of variance (ANOVA) was used to detect differences in visually evoked relative flow velocity time courses between smokers and nonsmokers. Repeated-measure ANOVA revealed marked difference in the peak systolic flow velocity time courses between smokers and nonsmokers (p< .001). Maximum percent change of visually evoked flow velocity after visual stimulation was 19+/-4% and 30+/-3% in smokers and nonsmokers, respectively (p< .0001). IMT values did not indicate atherosclerosis in young smokers. Infectious disease and hyperlipidemia were also ruled out by measurement of sensitive C-reactive protein and serum lipids. This is the first functional TCD study demonstrating impaired visually evoked flow velocity response caused by chronic cigarette smoking in otherwise healthy, young subjects. The impaired cerebral vasodilatory mechanism together with atherosclerosis may influence stroke occurrence and outcome in chronic smokers.     

Deuterated target comparison for pyroelectric crystal D-D nuclear fusion experiments

Different target materials were investigated to determine which ones are favorable to increasing the theoretical neutron yield using pyroelectric crystal D-D nuclear fusion. Calculations show that deuterated polyethylene (CD₂) will potentially yield the highest number of neutrons compared to the other targets investigated. However, deuterated plastic targets have been found to erode over the course of experiments.     

Mutation of alpha B-crystallin: effects on chaperone-like activity

A recent paper by Plater et al. [20], showed that the mutation of a single phenylalanine residue F27R in mouse alpha B completely abolished the chaperone-like property of alpha-crystallin when assayed with insulin at 25 degrees C or with gamma-crystallin at 66 degrees C. We have produced the same mutation as well as some additional mutations in human alpha B-crystallin. Our data suggest that the F27R mutation effected the thermal stability of alpha B-crystallin making it unstable at temperatures > or = 60 degrees C. In agreement with the published work, at these temperatures the F27R human recombinant alpha B-crystallin does not protect the target protein from aggregation. When assayed with insulin or alpha-lactalbumin at 25 or 37 degrees C, however, there were no differences in the protective abilities between the native alpha B-crystallin or the F27R mutated human alpha B-crystallin. Several other multiple mutations involving proline residues were also produced. These mutations did not effect the chaperone-like properties of human alpha B-crystallin, but some of them did effect the native molecular weight size as judged by gel filtration chromatography.