α-Glucosidase, α-amylase inhibition kinetics,in vitro gastro-intestinal digestion,and apoptosis inducing abilities of Ficus microcarpa L. f. and Ficus racemosa L. fruit polysaccharides

Food Science and Biotechnology - A rich source of nutrients, figs have a number of clinically validated benefits. This study aimed to evaluate the in vitro simulated gastrointestinal digestion, and...     

Energy storage options for wireless sensors powered by aircraft specific thermoelectric energy harvester

This paper describes an approach for efficiently storing the harvested energy from a thermoelectric module for powering autonomous wireless sensor nodes in aircraft health monitoring applications. Thermoelectric devices are the preferred option due to the widespread availability of significant levels of energy from the temperature gradients or variations at the aircraft, such as the cabin, the engine compartment, the fuel tanks or the inner and outer frame of the fuselage. Batteries and supercapacitors are popular choices of storage device, but neither represents the ideal solution, with, supercapacitors possessing low energy densities while batteries have low power density. When using a battery-only solution for storage, the runtime of a typical sensor node is typically reduced by the battery’s relatively high internal impedance and thermal loss. Supercapacitors can overcome some of these problems, but generally do not provide sufficient long-term energy to allow aircraft health monitoring applications to be operated over an extended period. A hybrid energy storage solution can provide both energy and power density to a wireless sensor node simultaneously. Techniques such as acoustic–ultrasonic, acoustic-emission, strain and crack wire sensors require storage approaches that can provide immediate energy on demand, usually in short, high intensity bursts, and that can be sustained over long periods of time, storing up to 40–50 J of energy. This application requirement is considered as a significant constraint when working with battery-only and supercapacitor-only solutions. The hybrid system described here provides an alternate viable solution.     

Enzymatic interesterification of palm and coconut stearin blends

Hard fractions of palm oil and coconut oil, blended in the ratios of 90:10, 85:15, 80:20 and 75:25, were interesterified for 8 h using Lipozyme TL IM. Major fatty acids in the blends were palmitic acid (41.7–48.4%) and oleic acid (26.2–30.8%). Medium‐chain fatty acids accounted for 4.5–13.1% of the blends. After interesterification (IE), slip melting point was found to decrease from 44.8–46.8 °C to 28.5–34.0 °C owing to reduction in solids content at all temperatures. At 37.5 °C, the blends containing 25% coconut stearins had 17.4–19% solids, which reduced to 0.4–1.5% on IE, and the slip melting point (28.6 and 28.8 °C) indicated their suitability as margarine base. The reduction in solid fat index of the interesterified fats is attributed to the decrease in high‐melting triacylglycerols in palm oil (GS₃ and GS₂U type) and increase in triolein (GU₃) content from 1 to 9.2%. Retention of tocopherols and β‐carotene during IE was 76 and 60.1%, respectively, in 75:25 palm stearin and coconut stearin blend.     

Effect of composition on steady state and transient photoconductivity in isocoordinated In<Subscript>x</Subscript>Sb<Subscript>30−x</Subscript>Se<Subscript>70</Subscript> (0 ≤ x ≤ 25) chalcogenide films

The study of steady state and transient photocurrent measurement provide important information about carrier generation and recombination phenomena in various semiconducting systems for photo-sensor device applications. In the present work, the composition dependent analysis of photocurrents was studied for thermally evaporated Se-rich In_xSb_30?xSe₇₀ films of average thickness 800 nm. The indirect optical gap has been calculated from the transmission and reflection data and the variation of molecular units was studied from the Raman spectroscopy. The initial rise of photocurrent sharply to approach a steady state value during illumination and fast decay to a constant persistent current after stopping the illumination has been observed. The intensity dependence of photocurrent obeys the power law I_Ph?=?F^γ, where the value of exponent tells about the recombination process. The decay of photocurrent has been fitted with stretched exponential function for different compositions and at different light intensities. These results are important for the development of low cost photo absorbers for solar cell applications and visible region responsive photo sensor devices.     

Crystallization kinetics of bulk amorphous Se-Te-Sn system

In the present work crystallization kinetics of the amorphous Se_80–xTe₂₀Sn_x (0 x 9) system have been investigated using Differential Scanning Calorimetry. From the heating rate dependence of the glass transition temperature and the crystallization temperature the activation energy for the glass transition and that for crystallization have been determined using the Kissingers equation and Matusitas equation for non-isothermal crystallization of materials. The effect of addition of Sn to the Se-Te system on the dimentionality of crystal growth has been investigated. An increase in the glass transition temperature with increase in Sn content suggests that Sn plays a role in cross-linking the already existing Se-Te chains which causes an increase in the thermal stability of the material.     

DESIGN OPTIMIZATION OF INDUCTION MOTORS WITH DIFFERENTIAL EVOLUTION ALGORITHMS WITH AN APPLICATION IN TEXTILE SPINNING

This article deals with the design optimization of a squirrel-cage three-phase induction motor, selected as the driving power of spinning machines in the textile industry, using three newly developed versions of differential evolution (DE) algorithms called modified DE versions (CMDE, GMDE, and LMDE). Efficiency, which decides the operating or running cost of the motor (industry), is considered as the objective function. First, the algorithms are applied to design a general purpose motor with seven variables and nine performance-related parameters with their nominal values as constraints. To make the machine feasible, practically acceptable to serve in textile industries, and less costly to operate, certain constraints are modified in accordance with the demands of the spinning application. Comparison of the optimum designs with the industrial (existing) motor reveals that the motor designed by the proposed algorithms consumes less power input.     

Heterogeneous crystallization and composition dependence of optical parameters in Sn–Sb–Bi–Se chalcogenides

Bulk samples of Sn₁₀Sb_20−x Bi _x Se₇₀ (0 ≤ x ≤ 8) chalcogenide alloys were prepared by the conventional melt quenching technique. Thin films were prepared on well-cleaned glass substrates by thermal evaporation technique. X-ray diffraction studies revealed that the alloys with x = 0 and 2 at.% of Bi were amorphous, whereas the alloys with x = 4, 6, 8 at.% were crystalline. The crystalline phases are identified as due to the formation of Bi₂Se₃ and BiSe₂ phases. The microstructural and differential scanning calorimetric studies show the presence of these phases. A simple, straight forward procedure suggested by Swanepoel has been used to calculate the optical parameters, refractive index, and extinction coefficient. The optical gap for all the samples has been obtained from the Tauc plots. The variation in optical parameters for different Bi concentration has been explained on the basis of presence of defect states and the change in stoichiometry with the change in Bi concentration.     

Experimental study on productivity enhancement of an improvised inclined solar still

Experimental studies are carried out on the inclined solar still with baffle plates for enhancing its performance. The baffles placed in the inclined solar still act as a solar collector which helps in increasing the contact time with solar radiation thereby raising the saline water temperature. Experiments are carried out during winter and early summer climate of Chennai, India. Experimental parameters, such as ambient temperature, solar radiation, glass temperature, water temperature and distillate output are recorded. Hourly productivity is found to be higher during sunny days. The estimated production of fresh water through analytical study is 3.50?kg/m² per day for a minimum mass flow rate of 0.0833?kg/min. The actual experimental yield is 2.793?kg/m² per day. Also, the inlet saline water temperature affects the yield and the latter is found to be highest at 48.5°C.