Effect of Dispersoid Size and Volume Fraction on Aging Behavior and Mechanical Properties of TiO2-Dispersed AA7075 Alloy Composites

TiO₂-dispersed AA7075 alloy composites were produced by mechanical milling followed by hot uniaxial compaction and sintering. The effects of volume fraction and dispersoid size on precipitation kinetics, densification, and hardness of the composites were studied in detail. While the sinterability of the composites decreases with increasing volume fraction of the particulate reinforcement (dispersoid), the same increases with decreasing particle size of the reinforcement. Microstructural analysis using X-ray diffraction and scanning electron microscopy shows an improvement in the distribution of reinforcement with decreasing particle size. The hardness of the composites increases with increasing volume fraction and decreasing TiO₂ particle size. Further, the reinforced composites do not show age hardenability unlike unreinforced AA7075 alloy. Microstructural analysis reveals the formation of MgTiO₃ and ZnO near the TiO₂-AA7075 interface, which suppresses the formation of Guinier-Preston (GP) zone resulting in no age hardenability of the composites.     

Successful Implementation of eRx Systems: Creating Technology–Organization Alignment using the Strategy-Map Approach

The adoption rates of eRx systems continue to be low and their implementation remains uneven. Rooted in the theories of technology–organization alignment and strategy maps, this article develops a framework for successful implementation of eRx systems. The proposed strategy map outlines the key strategic processes that would make implementation of eRx systems not only feasible and successful, but also a profitable venture for healthcare organizations.     

Removal of fat from Cow's milk decreases the vitamin E contents of the resulting dairy products

The present study was undertaken to determine whether decreases in fat contents result in lower vitamin E contents. Milk samples of varying fat contents (half and half, whole milk, reduced-fat milk low-fat milk, and nonfat milk) were obtained from a local dairy on six different occasions, α-locopherol was the major form of vitamin E (>85%); γ-tocopherol and α-tocotrienol were present to a lesser extent. As the fat contents of milk products decreased from 11 to 0.3%, the vitamin E contents decreased. For example, raw milk as compared to nonfat milk had both higher α-tocopherol contents (45.5+-4.6 vs. 4.5±0.5 μg/100 g; P<-0.0001) and higher total lipids ( 3.46±0.49 vs. 0.30±0.07 g/100 g; P≤0.0001). Vitamin E, cholesterol, and total lipids increased as cream was added back to nonfat milk during production. For every 1 mg cholesterol increase, there was an increase of approximately 4 μg of α-tocopherol; for every 1 g total lipids increase, the α-tocopherol content increased by 17 μg. These data demonstrate that removal of milk fat markedly decreases the vitamin E content of various milk products     

印度连铸发展概况

尽管印度钢铁工业采用连铸工艺可以追溯到20世纪60年代,但是直到80年代早期,钢铁联合企业才部分选择使用这项技术,它的应用才有突破性进展.从此,连铸在印度有了重大发展,到90年代中期,几乎所有的钢铁联合企业都部分或全部采用这种技术.今天超过65%的印度钢材是通过连铸工艺生产的.同时由于新技术的引进,机械设计和制造工序也经历了重大的变革.2003年,印度钢产量达3180万t,其中有2080万t是通过连铸工艺生产的.现在,印度采用连铸工艺生产的钢材有进一步增长的趋势,尤其是难浇铸钢种、双相钢和其它特种钢.笔者试图对当前印度连铸工艺概况进行全面评价.连铸工艺在印度具有巨大的发展潜力,未来的印度钢材几乎100%将要通过连铸生产.     

Influence of dietary spices – Black pepper,red pepper and ginger on the uptake of β-carotene by rat intestines

In view of the wide-spread deficiency of vitamin A in populations dependent on plant foods, it is desirable to improve bioavailability of β-carotene. Specific dietary spices may alter the ultrastructure and permeability characteristics of intestines. Few common spices were studied here for their possible influence on intestinal absorption of β-carotene by examining its uptake by the intestines from rats fed black pepper, red pepper, ginger, piperine and capsaicin. Higher in vitro absorption of β-carotene in the intestines was evidenced in all spice-fed animals. Dietary piperine and ginger increased the uptake of β-carotene by 147% and 98%, respectively. While increase in absorption was 59% and 27% in black pepper and red pepper fed animals, respectively, dietary capsaicin increased the same by 50%. Thus, significantly enhanced intestinal uptake of β-carotene as a result of consumption of pungent spices was evidenced, which could form a food based strategy to possibly reduce vitamin A deficiency.     

Revisiting Metal Sulfide Semiconductors: A Solution‐Based General Protocol for Thin Film Formation,Hall Effect Measurement,and Application Prospects

Nanostructured thin films of metal sulfides (MS) are highly desirable materials for various optoelectronic device applications. However, a general low‐temperature protocol that describes deposition of varieties of MS structures, especially in their film form is still not available in literatures. Here, a simple and highly effective general solution‐based deposition protocol for highly crystalline and well‐defined nanostructured MS thin films from ethanol on variety of conducting and non‐conducting substrates is presented. The films display remarkable electronic properties such as high carrier mobility and high conductivity. When NiS thin film deposited on a flexible polyethylene terephthalate (PET) substrate is used as a fluorine doped tin oxide (FTO)‐free counter electrode in dye‐sensitized solar cells, it exhibits a solar‐to‐electric power conversion efficiency of 9.27 ± 0.26% with the highest conversion efficiency as high as 9.50% (vs 8.97 ± 0.07% exhibited by Pt‐electrode). In addition, the NiS film deposited on a Ti‐foil has demonstrated an outstanding catalytic activity for the hydrogen and oxygen evolution reactions from water.     

α-Amylase inhibitors in chick pea (cicer arietinum L)

The α-amylase inhibitory activity of 28 varieties of chick pea (Cicer arietinum L) was determined, and KGT/GBS-8 was found to have the greatest activity (81.4 units g^?1). The inhibitor was heat labile and the inhibitory activity decreased during germination.     

Role of cell polarity dynamics and motility in pattern formation due to contact-dependent signalling

A key challenge in biology is to understand how spatio-temporal patterns and structures arise during the development of an organism. An initial aggregate of spatially uniform cells develops and forms the differentiated structures of a fully developed organism. On the one hand, contact-dependent cell–cell signalling is responsible for generating a large number of complex, self-organized, spatial patterns in the distribution of the signalling molecules. On the other hand, the motility of cells coupled with their polarity can independently lead to collective motion patterns that depend on mechanical parameters influencing tissue deformation, such as cellular elasticity, cell–cell adhesion and active forces generated by actin and myosin dynamics. Although modelling efforts have, thus far, treated cell motility and cell–cell signalling separately, experiments in recent years suggest that these processes could be tightly coupled. Hence, in this paper, we study how the dynamics of cell polarity and migration influence the spatiotemporal patterning of signalling molecules. Such signalling interactions can occur only between cells that are in physical contact, either directly at the junctions of adjacent cells or through cellular protrusional contacts. We present a vertex model which accounts for contact-dependent signalling between adjacent cells and between non-adjacent neighbours through long protrusional contacts that occur along the orientation of cell polarization. We observe a rich variety of spatiotemporal patterns of signalling molecules that is influenced by polarity dynamics of the cells, relative strengths of adjacent and non-adjacent signalling interactions, range of polarized interaction, signalling activation threshold, relative time scales of signalling and polarity orientation, and cell motility. Though our results are developed in the context of Delta–Notch signalling, they are sufficiently general and can be extended to other contact dependent morpho-mechanical dynamics.     

Experimental investigation on the effect of melt delivery tube position on liquid metal atomization

Metal powders are often made by gas atomization of liquid metal. During the process, liquid metal which flows from a melt delivery tube (MDT) is atomized by high speed gas discharging from a gas nozzle. In this work, the effect of the melt delivery tube position on atomization outcomes such as the yield, mass median diameter, and spread of the particle size distribution, is studied experimentally. A melt atomization setup (pilot-scale) is used to produce tin powder by gas-atomization. Three MDT positions, namely, intruded, extruded and flush with respect to the gas nozzle, are chosen for this study. Three pressure regimes (atmospheric, aspiration and pressurization) are established by varying the relative distance between the MDT and the gas nozzle exit for the three positions. Experimental investigations revealed that the intruded position produces powder with lower mean particle sizes and lower spread than the extruded configuration. The intruded position also gives a significantly higher yield compared to the extruded and flush positions at low gas flow rates, and hence appears to be the most suited for metal atomization using a free-fall configuration.