Addition effects of bovine blood globin and sodium caseinate on the quality characteristics of raw and cooked ham pâté

The incorporation of 3% globin bovine extracted by the acidified acetone (AG) and carboxymethylcellulose (CG) methods as replacer for sodium caseinate (CA) in ham paté was evaluated. The raw paté batter was evaluated for salt-soluble protein content (SSP), water holding capacity (WHC) and raw batter stability (RBS). The results of CG were similar to those of CA, having both improved two of the three paramaters studied, and AG was the most deleterious, having decreased SSP, WHC and RBS. Only the AG incorporation had unfavorable effects on the cooked ham paté, decreasing the pH and increasing the thiobarbituric acid reactive substances (TBARS) over the storage period (0-45 days). The results suggest CG as the best replacer for CA as the emulsifying agent for ham paté.     

The 2-D-3-D crossover in modulation-doped GaAs-Ga1-xAlxAs quantum wells

We report on a method to analyze the 2-D-3-D crossover in n-type modulation-doped quantum wells. Finite well barrier, first and second subband population, many-body effects, and residual doping are included in our calculation. We found that the 2-D-3-D crossover remarkably depends not only upon the geometrical parameters, as for instance, the spacer layer width and quantum-well width, but also upon a residual p-type doping intentionally introduced. A diagram showing the 2-D-3-D dimensional crossover is presented     

Investigation of the magnetic field dependence of electronic andoptical properties in one-side modulation-doped GaAs-Ga1-xAlxAs quantum wells

The magnetic field dependence of the two-dimensional electron density, ground state energy, Fermi energy, photoluminescence transition energy, and oscillator strength are systematically studied in GaAs-Ga _1-xAl_xAs one-side modulation-doped quantum wells (QW's). Coupled Schrodinger and Poisson equations are solved self-consistently by means of the extended Fang-Howard variational approach. The calculation is performed within the effective mass approximation, considering finite well barriers and assuming exchange-correlation correction of the conduction band edge. We found an oscillatory behavior, similar to the ordinary Shubnikov-De Haas oscillation, for the magnetic dependence of all properties investigated. In particular, the calculated magnetic dependence of the oscillator strength is compared with experimental data     

Collaborative eScience libraries

In the context of collaborative eScience, digital libraries are one of many distributed, interoperable resources available to scientists that facilitate both human and machine collaboration: machine collaboration in the form of standards such as the Open Archives Initiative Protocol for Metadata Harvesting and human collaboration in the form of collaborative workspaces. This paper describes a set of collaborative workspaces created at the Los Alamos National Laboratory Research Library, initial patterns of use, and additional user requirements determined based on these initial patterns of use.     

Technologizing Africa: On the bumpy information highway

Although the microcomputer and the Internet continue to advance rapidly in Western cultures, developing nations, especially those in Africa, are lagging behind—a situation that continues to widen the gap between the haves and the have-nots of the world. This article offers the rare opportunity to get a glimpse of Africa on the information highway and documents the use of computers in the educational systems of three African nations: Ghana, Kenya, and Egypt. It documents the progress these countries have made in exposing their citizens to information technology and reveals the challenges they face in closing the digital divide that Africans continue to experience. In presenting how these countries adapt to technological change, one may better understand why Africa's ride on the information highway is rutted.     

Influence of the arc length on metal transfer in the single potential double-wire MIG/MAG process

The search for competitiveness in the modern industries, represented by demands for higher productivity and cost reduction, leads to investment in new technologies. This is the context in which the double-wire MIG/MAG process was conceived; the idea was to design a process that combines the versatile features of the MIG/MAG process with the high productivity of the submerged arc process. The objective of this work was to evaluate the influence of different arc lengths, at the same current level, on the metal transfer modes and the bead geometry profiles. Using equipment consisting of two linked power sources and a torch with single electrical potential, the series of welds was carried out at three different arc length conditions.

A methodology to obtain different arc lengths at the same current and wire-feed speed levels was proposed and validated. The metal transfer was observed using the shadowgraph technique with a high-speed camera, while the geometry was evaluated from macrographies of weld bead transversal sections. A trend in transfer mode changes was observed from short circuit to spray for the highest arc lengths, and to a much higher attraction between the drops. This change in the transfer mode implies better beads finishing and higher thermal and deposition efficiencies.     

Nanostructured severe plastic deformation processed titanium for orthodontic mini-implants

Titanium mini-implants have been successfully used as anchorage devices in Orthodontics. Commercially pure titanium (cpTi) was recently replaced by Ti-6Al-4 V alloy as the mini-implant material base due to the higher strength properties of the alloy. However, the lower corrosion resistance and the lower biocompatibility have been lowering the success rate of Ti-6Al-4 V mini-implants. Nanostructured titanium (nTi) is commercially pure titanium that was nanostructured by a specific technique of severe plastic deformation. It is bioinert, does not contain potentially toxic or allergic additives, and has higher specific strength properties than any other titanium applied in medical implants. The higher strength properties associated to the higher biocompatibility make nTi potentially useful for orthodontic mini-implant applications, theoretically overcoming cpTi and Ti-6Al-4 V mini-implants. The purposes of the this work were to process nTi, to mechanically compare cpTi, Ti-6Al-4 V, and nTi mini-implants by torque test, and to evaluate both the surface morphology and the fracture surface characteristics of them by SEM. Torque test results showed significant increase in the maximum torque resistance of nTi mini-implants when compared to cpTi mini-implants, and no statistical difference between Ti-6Al-4 V and nTi mini-implants. SEM analysis demonstrated smooth surface morphology and transgranular fracture aspect for nTi mini-implants. Since nanostructured titanium mini-implants have mechanical properties comparable to titanium alloy mini-implants, and biocompatibility comparable to commercially pure titanium mini-implants, it is suggestive that nanostructured titanium can replace Ti-6Al-4 V alloy as the material base for mini-implants.     

Effect of flaxseed oil in diet on fatty acid composition in the liver of Nile tilapia (Oreochromis niloticus)

This study analyzed the effects of different concentrations of flaxseed oil (FO) on the proximate composition and the contents of alpha-linolenic acid (LNA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), and docosahexaenoic (DHA, 22:6n-3) fatty acids in the liver of cultured Nile tilapia (Oreochromis niloticus). During the five-month culture period, tilapias were given diets with incremental concentrations of FO (0.00%; 1.25%; 2.50%; 3.75%, and 5.00%) as a replacement of sunflower oil (control). There was no significant difference in moisture and ash content in the liver between treatments. Protein values ranged from 12.1% (treatment II) to 13.9% (treatment V) and total lipids ranged from 5.6% (treatment V) to 7.2% (treatment II). There was no significant difference between most treatments. Fatty acid methyl esters (FAMEs) were quantitatively analyzed by capillary gas chromatography against a C(23:0), internal standard. Variations in concentrations (in mg g(-1) of total lipids) of fatty acids between treatment I and treatment V ranged from 4.2 to 51.2 (LNA), from 0.2 to 2.3 (EPA), and from 10.6 to 56.2 (DHA), respectively. This experiment demonstrated that increasing amounts of LNA in feed may markedly increase the amounts of LNA, EPA, and DHA in the liver of Nile tilapia.     

Mode III interlaminar fracture of carbon/epoxy laminates using the Six-Point Edge Crack Torsion (6ECT)

The recently proposed Six-Point Edge Crack Torsion (6ECT) test was used to evaluate the mode III interlaminar fracture of carbon/epoxy laminates. Plate specimens with starter delaminations in 0/0, 0/90 and 0/45 interfaces were tested. Data reduction was performed with an effective crack scheme validated in a previous numerical study. The tests allowed the evaluation of fairly unambiguous initiation G_IIIC values and of subsequent R-curves. Examinations of specimen cross-section showed considerable lengths of pure interlaminar propagation in specimens with starter delaminations in 0/90 and 0/45 interfaces. The latter specimens had the lowest initiation G_IIIC values.