Theoretical investigations on low energy surfaces and nanowires of MgH(2)

The phase stability, chemical bonding, and electronic structure of MgH(2) nanowires and possible low energy surfaces of α-MgH(2) thin films have been investigated using the ab initio projected augmented plane-wave method. Structural optimizations based on total energy calculations predicted that, for the α-MgH(2) phase, the (101) surface is more stable among the possible low energy surfaces. The electronic structure study reveals that the nanowires also have nonmetallic character similar to that of the bulk and thin film phases. Bonding analysis shows that the character of chemical bonding in nanowires has been considerably changed compared with that in bulk phases. Similarly, the bond distances in the surfaces of nanowires are found to be higher than in the bulk material, suggesting that it is possible to remove hydrogen from the nanowires considerably more easily than from bulk crystals.     

Subcortical cognitive impairment in dialysis patients

Given the high burden of atherosclerotic cardiovascular disease in dialysis patients, we hypothesized that cognitive testing would reveal subtle abnormalities in subcortical brain function, a measure frequently associated with cerebrovascular disease. Detailed neurocognitive testing was performed in 25 hemodialysis patients. All patients had Mini-Mental State Examination (MMSE) scores >24 and had no history of cerebrovascular disease. Where appropriate, scores were normalized for age, gender, and education. One-sample t tests were used to compare differences in cognitive function between dialysis patients and normative data. The mean age was 57 years, and the mean MMSE was 27.5. Fourteen subjects (56%) were females, and 15 white (60%). Results of the North American Adult Reading Test, a measure of verbal intelligence, were comparable with the general population. Similarly, measures of cortical function, namely retention and recognition scores from the Word List Learning subtest of the Wechsler Memory Scale-III, were preserved when compared with normative data where reference = 10. Significant deficits were seen on tests assessing subcortical function: scores (mean+/-standard deviation) for block design, and symbol coding subtests of the Wechsler Adult Intelligence Scale-III were 7.0+/-1.7 and 7.7+/-3.1, respectively (p<0.001 for both comparisons with normative data). Similarly, adjusted scores on the trails A and B tests were 40.5+/-8.3 and 41.8+/-11.3, respectively (p<0.001 for both comparisons with normative data where reference= 50). These results suggest that, despite relatively normal MMSE scores, mild cognitive impairment may be prevalent in hemodialysis patients. The pattern of cognitive dysfunction is primarily subcortical in nature.     

Indian black rice: A brewing raw material with novel functionality

Indian black rice (Chakhao Poireiton) is a pigmented variety, rich in anthocyanins and other phytonutrients. With growing interest in the use of local raw materials in brewing, it was of interest to develop protocols for malting and brewing with Chakhao Poireiton to see whether the antioxidant capacity of anthocyanins could be delivered into finished beer. Protocols for brewing with 100% malted rice were developed and the performance of Indian black rice compared with that of an Italian white rice cultivar suited to brewing. The apparent fermentabilities of rice worts were 69.5% (black) and 67.3% (white), yielding beers of 3.28 and 3.19% ABV respectively. Black rice worts were deficient in free amino nitrogen (83.5 mg/L relative to 137 mg/L for white rice) and would need nitrogen supplementation to avoid issues with fermentation, e.g. elevated diacetyl. Black rice beer had an orange-red hue as a result of extraction of anthocyanin pigments (2.84 mg/L). The oxidative stability of 100% rice beers was measured using electron spin resonance spectroscopy and both samples were found to be unusually stable. Interestingly, when rice beers were blended with a control barley malt derived lager in varying proportions (10, 25, 50%), the oxidative stability was improved, relative to the control lager, particularly so in the case of black rice beer, which contained an antioxidant capacity over and above that of the white rice beer. Future studies are required to determine whether the noted oxidative stability of 100% rice malt beers results in a more flavour-stable beer. © 2019 The Institute of Brewing & Distilling     

Phytosterols in Seaweeds: An Overview on Biosynthesis to Biomedical Applications

Seaweed extracts are considered effective therapeutic alternatives to synthetic anticancer, antioxidant, and antimicrobial agents, owing to their availability, low cost, greater efficacy, eco-friendliness, and non-toxic nature. Since the bioactive constituents of seaweed, in particular, phytosterols, possess plenty of medicinal benefits over other conventional pharmaceutical agents, they have been extensively evaluated for many years. Fortunately, recent advances in phytosterol-based research have begun to unravel the evidence concerning these important processes and to endow the field with the understanding and identification of the potential contributions of seaweed-steroidal molecules that can be used as chemotherapeutic drugs. Despite the myriad of research interests in phytosterols, there is an immense need to fill the void with an up-to-date literature survey elucidating their biosynthesis, pharmacological effects, and other biomedical applications. Hence, in the present review, we summarize studies dealing with several types of seaweed to provide a comprehensive overview of the structural determination of several phytosterol molecules, their properties, biosynthetic pathways, and mechanisms of action, along with their health benefits, which could significantly contribute to the development of novel drugs and functional foods.     

Identification of the compound in a potent cranberry juice extract that inhibits lipid oxidation in comminuted muscle

An extract prepared from cranberry juice powder using a mixture of chloroform and methanol was particularly effective at inhibiting lipid oxidation in mechanically separated turkey (MST), providing more than 3 weeks of additional stability during −4 °C storage at a usage level of 0.1% (wet weight basis). The chloroform extract was fractionated by flash chromatography (FC) and analysed using reverse-phased high performance liquid chromatography (RP-HPLC) with UV/vis diode array detection to identify the component(s) present in the fractions. One of the five fractions obtained was effective in delaying the formation of lipid peroxides and thiobarbituric acid reactive substances (TBARS) in MST, while the remaining fractions had little to no inhibitory action. Mass spectrometry (MS) analysis indicated the presence of two flavonols, quercetin and quercetin-3-O-(6″-benzoyl)-β-galactoside in the inhibitory fraction. This fraction (containing quercetin at 467 μmol/kg MST) inhibited lipid oxidation in MST similarly to pure quercetin added to MST at the same concentration. This indicated that quercetin accounted for all or nearly all of the inhibitory capacity in the chloroform extract.     

High power universal piezoelectric transformer

This study describes a multilayer piezoelectric voltage and power transformer that has one direction poling, operates in a wide-frequency range and delivers both step-up and step-down voltages by inverting the electrical connections. In this design, the input and output electrodes are on the same side of the disk and are isolated from each other by a fixed isolation gap. The electrode pattern is a ring/dot structure such that it uses radial mode for both input and output part that are built-in on the same ceramic disk. A prototype transformer was fabricated of size 15 x 2.78 mm2 having mass of 3.8 gm. In the step-down configuration at the constant output power of 6 W, the transformer characteristics across a 100 omega load were found to be efficiency = 92%, gain = 0.21 input voltage = 110 V(rms), and temperature rise = 20 degrees C from the room temperature. In the step-up configuration at the constant output power of 5 W, the transformer characteristics across a 5 komega load were found to be efficiency = 97%, gain = 9.5, input voltage = 16 V(rms), and temperature rise = 8 degrees C from the room temperature. A detailed equivalent circuit analysis of the transformer was done, and the results were found to be in excellent agreement with the experimental results.     

Spectroscopic studies on DLC/TM (Cr,Ag, Ti,Ni) multilayers

The hydrogen-free diamond-like carbon (DLC) films with transition metal (TM = Cr, Ag, Ti, Ni) interlayer (bilayer and multilayer) were deposited on to stainless steel and silicon substrates using pulsed laser deposition technique. Secondary ion mass spectroscopy (SIMS) confirmed that the films were hydrogen free. Incorporation of chromium inter layer reduced the stress value by about 3 GPa as determined by micro Raman spectroscopy. Incorporation of the TM inter layer enhanced the photoluminescence (PL) intensity as compared to the monolithic DLC films. The optical band gap determined by spectroscopic ellipsometry for DLC/TM films was found to be in the range of 1.56–1.67 eV.     

Mart Algorithms for Circular and Helical Cone-Beam Tomography

The present work is concerned with the evaluation of the performance and the efficient implementation of multiplicative algebraic reconstruction technique (MART) to reconstruct three-dimensional (3D) objects for two different source/detector trajectories. Three types of MART algorithms are tested on a numerical phantom (Defrise), and they are implemented on a 3D X-ray system of Vikram Sarabhai Space Centre (VSSC). Circular and helical cone-beam trajectories are used. The results are compared with convolution backprojection (CBP) algorithm for each trajectory. It is found that iterative algorithms perform better than their counterpart, the transform-based CBP algorithm, whenever tomography systems are ill-conditioned due to limited views and/or noisy projection data.     

Socio-economic and political barriers to public participation in EIA: implications for sustainable development in the Maldives

Abstract

Environmental impact assessment (EIA) is a policy process that can lead to more sustainable development by preventing or mitigating the negative impacts of development projects. Public participation in the EIA process, especially one based on the ideals of deliberative democracy, is essential to deliver on the goal of sustainable development that is arguably the primary objective of EIA. This article specifically focuses on a study of public participation in the EIA process of the Maldives. Using a qualitative research design involving an analysis of documents and interviews, it investigates four aspects of a deliberative participatory process: fairness, competence, willingness and capacity. The analysis suggests that the process for public participation in the Maldives cannot be characterized as fully fair or competent. It further identifies several socio-economic barriers that affect the capacity and willingness of the actors to participate including political influence, lack of human and financial capacity, gender gap, loss of community spirit and lack of environmental and procedural awareness.     

Higher-Order Numerical Scheme for the Fractional Heat Equation with Dirichlet and Neumann Boundary Conditions

In this article, we consider a higher-order numerical scheme for the fractional heat equation with Dirichlet and Neumann boundary conditions. By using a fourth-order compact finite-difference scheme for the spatial variable, we transform the fractional heat equation into a system of ordinary fractional differential equations which can be expressed in integral form. Further, the integral equation is transformed into a difference equation by a modified trapezoidal rule. Numerical results are provided to verify the accuracy and efficiency of the proposed algorithm.