Diffusion in evaporated films of magnesium-aluminium

VACUUM deposition can easily produce metal films of uniform thickness. When two such metal films are deposited, one over the other, and the resultant double layer film is annealed , diffusion will occur at the common interface, resulting in the formation of either a solid solution or intermetallic compounds or both. The presence of the diffusion layers can be confirmed by electron -diffraction or X-ray diffraction or deduced from other measurements , such as electrical resistance or adhesion ( Weaver and Hill, 1959). These methods can give only a qualitative picture and cannot normally give the rate of growth of the diff-usion layer and hence the diffusion coefficient of the system . Techniques used for determining diffusion coefficients in bulk diffusion couples are inapplicable to the study in evaporated thin films, since it is imp-ossible to section them, and the quantity of material available is not sufficient for chemical analysis. In thin films it is much more convenient to measure the time required for one film to be completely penetrated by atoms of the other metal. This can be done simply by measuring the variation of reflectivity with time and this technique has been used by Schopper (1955)2 for study of diffusion of lead into gold and by Weaver and Browne (1962, 1963, 1968 ) for study of diffusion in evaporated film of gold-aluminium , gold-lead and silver-aluminium

Diffusion in Evaporated Films of Magnesium-Aluminium

Vaccum deposition can easily produce metal films of uniform thickness. When two such metal films are deposited, one over the other, and the resulted double layer film is annealed, diffusion will occur at the common interface, resulting in the formation of either a solid solution, or intermetallic compounds or both. The presence of the diffusion layers can be confirmed by electron-diffraction, or X-ray diffrection or deduced from othe measurements, such as electrical resistance or adhesion

Recent Advances in the Technology of Aluminium- Magnesium Alloys

ALLOYS of aluminium with copper. to which smallamounts of manganese. magnesium and silicon are added, belong to the well known group of alloys termed "'Duralumin ', and were amongst the earliest of aluminium alloys to be used commercially on account of their age-hardening characteristics. Alloys of aluminium with magnesium as the principal alloying element, first attracted the interest of investigators as early as 1900, and since then, cast alloys containing as much as 10% magnesium have been used for specified purpose

Effect of cowpea flour processing on the chemical properties and acceptability of a novel cowpea blended maize porridge

Childhood growth stunting is a pervasive problem in Malawi and is in large part due to low quality complementary foods and chronic gut inflammation. Introducing legumes such as cowpea (Vigna unguiculata) into the complementary diet has the potential to improve childhood growth by improving diet quality through improvements in macro- and micronutrients and also by reducing gut inflammation. However, cowpea is relatively underutilized in complementary feeding in Malawi due to its strong taste, long processing time, and high energy requirements for processing. Effective utilization of cowpea in complementary feeding requires processing which may affect chemical composition as well as sensory quality. The present study evaluated the effect of processing on the retention of zinc, crude fibre, and flavonoid in roasted, boiled, and dehulled cowpea flours, and assessed the acceptability of maize porridge (70%) enriched with one of the three cowpea flours (30%). Roasting, dehulling, and boiling did not have any effect on zinc content. Crude fibre content increased after processing by all methods. Processing had no effect on measurable flavonoids. Roasted, boiled, and dehulled cowpea blended maize porridges were acceptable to children with mean quantities of leftover food of less than 3g from the given 100g. Caregivers also rated the blended flours to be highly acceptable to them as well, with maize porridge blended with dehulled cowpea flour the most acceptable to both children and caregivers. These results demonstrate that cowpea flour, processed by any of these three different methods, could serve as a useful addition to maize porridge for complementary feeding of children in sub-Saharan Africa

The Effect of Misch Metal Additions on the Structure and Workability of Al-Mg (7-100/.) Alloys

ON the alloying elements used in aluminium alloys, copper was one of' the earliest employed commercially and for many years it has been the principal one. Aluminium-copper alloys to which manganese, magnesium or silicon has been added, belong to the important group generally known as "Duralumin". The binary alloys of aluminium with magnesium attra- cted the interest of investigators as early as 1900. There have been numerous attempts to utilise for general purposes alloys containing as Much as 10% magnesium ; alloys containing up to 30% magnesium have been used for special purposes

Clinical Research Environment in India: Challenges and Proposed Solutions.

India has compelling need and keen aspirations for indigenous clinical research. Notwithstanding this need and previously reported growth the expected expansion of Indian clinical research has not materialized. We reviewed the scientific literature, lay press reports, and ClinicalTrials.gov data for information and commentary on projections, progress, and impediments associated with clinical trials in India. We also propose targeted solutions to identified challenges. The Indian clinical trial sector grew by (+) 20.3% CAGR (compound annual growth rate) between 2005 and 2010 and contracted by (-) 14.6% CAGR between 2010 and 2013. Phase-1 trials grew by (+) 43.5% CAGR from 2005-2013, phase-2 trials grew by (+) 19.8% CAGR from 2005-2009 and contracted by (-) 12.6% CAGR from 2009-2013, and phase-3 trials grew by (+) 13.0% CAGR from 2005-2010 and contracted by (-) 28.8% CAGR from 2010-2013. This was associated with a slowing of the regulatory approval process, increased media coverage and activist engagement, and accelerated development of regulatory guidelines and recuperative initiatives. We propose the following as potential targets for restorative interventions: Regulatory overhaul (leadership and enforcement of regulations, resolution of ambiguity in regulations, staffing, training, guidelines, and ethical principles [e.g., compensation]).Education and training of research professionals, clinicians, and regulators.Public awareness and empowerment. After a peak in 2009-2010, the clinical research sector in India appears to be experiencing a contraction. There are indications of challenges in regulatory enforcement of guidelines; training of clinical research professionals; and awareness, participation, partnership, and the general image amongst the non-professional media and public. Preventative and corrective principles and interventions are outlined with the goal of realizing the clinical research potential in India

Synthesis & Characterisation of Bis-dithiocarbamato Complexes of Bis-p-biphenyltin (IV)

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