Studies on in vitro evaluation of antidiabetic potentials of watermellon and pomegranate peels

Diabetes is a metabolic disorder which results due to deficiency in insulin and its metabolism. At present, the prevalence of Diabetes has increased worldwide and predicted to increase to greater extent in future generations. Among various therapeutic approaches implemented to prevent diabetes is to regulate the blood glucose levels by various mechanisms. This is being assessed by in vitro antidiabetic assays such as inhibition of carbohydrate digesting enzymes and non-enzymatic glycosylation of haemoglobin. Inhibition of alpha-amylase enzyme suppresses the level of production of glucose and by inhibiting glycosylation of haemoglobin the level of blood glucose is maintained. Hence the current work focuses on investigating the anti-diabetic activity of fruit peel of Citrullus lanatus (watermelon) and Punica granatum (pomegranate) using the above mentioned assays. Our results suggested that methanol extract of Citrullus lanatus and Punica granatum peels showed potential anti-diabetic activity in vitro which indicates that these extracts can be taken further for in vivo studies.Keywords: fruit peels, antidiabetic activity, α-amylase enzyme, glycosylated haemoglobi

Post-Demagnetization Performance Assessment for Interior Permanent Magnet AC Machines

This paper assesses the post-demagnetization performance of interior permanent magnet (IPM) ac machines by employing the more accurate recoil line approach based on a 2-D transient finite-element analysis (FEA). The method predicts continuous demagnetization of each magnet element undergoing partial demagnetization and evaluates the machine behavior after an event of short-circuit faults across its terminals. Along with the short-circuit faults, a failure in a drive controller or a position sensor, which may lead to a reverse voltage across the machine terminals that can eventually be more fatal and can cause significant reduction in the performance due to high levels of demagnetization, is analyzed as the worst case scenario. The FE predicted post-demagnetization performance is validated by experimental measurements in which a six-phase IPM machine designed for electric vehicle traction is allowed to lose its synchronization with the inverter when forced to operate on a torque-speed envelope, which is way beyond the drive voltage setting

Software Quality Assurance-Challenges in Launch Vehicle Projects

Launch vehicle projects now depend on software, more than ever before, to ensure safetyand efficiency. Such critical software syfiems, which can lead to injury, destruction or loss ofvital equipment, human lives, and damage to environment, must be developed and verified withhigh level of quality and reliability. An overview of current quality practices pursued in launchvehicle projects is presented in this paper. These practices have played a vital role in the successfullaunch vehicle missions of Indian Space Research Organisation. As complexity of softwareincreases, the activity that gets affected is nothing but, software quality assurance (SQA). TheSQA team is facing a lot of challenges in current practices. This paper brings out such challengesin different phases of software life cycle. A set of key points to some techniques and tools, thatcould contribute to meet the software quality 'assurance challenges in launch vehicle projects,are also discussed

Computationally Efficient 3D Eddy Current Loss Prediction in Magnets of Interior Permanent Magnet Machines

This paper proposes a computationally efficient method based on imaging technique, for accurate prediction of 3- dimensional (3D) eddy current loss in the rotor magnets of interior permanent magnet (IPM) machines. 2D time-stepped finite element analysis is employed to generate the radial and the tangential 2D magnetic field information within the magnet for application of the 3D imaging technique. The method is validated with 3D time-stepped finite element analysis (FEA) for an 8 pole-18 slot IPM machine evaluating its resistance limited magnet loss with increase in axial and tangential segmentation. Magnet loss considering eddy current reaction at high frequencies is evaluated from the proposed method by employing the diffusion of the 2D magnetic field variation along the axial plane. The loss associated with all the frequencies together in the armature currents is evaluated by considering each of the harmonics separately in the proposed method employing the frozen permeability to account for magnetic saturation. The results obtained are verified with 3D FEA evaluating the magnet loss at fundamental, 10 and 20 kHz time harmonics in armature currents

Prediction of 3D High Frequency Eddy Current Loss in Rotor Magnets of SPM Machines

This paper proposes a computationally efficient method, for accurate prediction of 3-dimensional (3D) high frequency eddy current loss in the rotor magnets of surface mounted permanent magnet machines employing the imaging method. 2D finite element analysis (FEA) is used to generate the information on radial and tangential 2D magnetic field variations (eddy current sources) within the magnet. The diffusion of eddy current sources along the axial plane of the magnet computed analytically is incorporated in the imaging method to establish the 3D eddy current source variations within the magnet. The modified method is validated with results from 3D time-stepped finite element analysis (FEA) for an 8-pole, 18-slot permanent magnet machine, evaluating its magnet loss considering axial and circumferential segmentation

Characterization and phylogenetic analysis of alkaline α-amylase producing Brevibacillus laterosporus from mountain climatic zone of India

α-amylases (EC3.2.1.1) are glycoside hydrolases that breakdown complex starch and maltodextrins into glucose and maltose by acting upon 1,4-glycosidiclinkages. Several amylases have been isolated and purified from members of Bacillus community, which find extensive application in starch processing, textile and pharmaceutical industry. Keeping this in mind we isolated α-amylase producing gram positive bacterium from soils collected from mountain climatic zone of India and identified it as Brevibacillus laterosporus. We further studied the effect of temperature and pH on the amylase activity of this strain and found a very stable activity at alkaline pH of 10 and temperature of 45 ºC. To our knowledge this a first report on characterization and evolutionary analysis of alkaline α-amylase producing Brevibacillus laterosporus isolated from unexplored sites of mountain climatic zone of India. Keywords: Climatic zone, Brevibacillus, Amylase, 16S rRNA gene sequencing, Phylogenetic analysi

Magnetoelectric coupling in strained strontium titanate and Metglas based magnetoelectric trilayer

Direct magneto electric coupling is observed with a magnetoelectric coupling coefficient (MECC) of 806 mV cm−1 Oe−1 at 750 Hz in strontium titanate (STO) - Metglas - strontium titanate (STO-Metglas-STO) trilayer thin films with a total thickness of 600 nm. The piezoelectricity in the strained STO layer, which is otherwise a paraelectric material, enabled the sandwiched magneto electric structure to exhibit a fair sub resonant magneto electric coupling. Theoretical models proposed by Bichurin et al. and Hasanyan et al. are employed to calculate the values of MECC at sub resonant condition for the system, which is noted as 853 mV cm−1 Oe−1. The frequency dependence of MECC coefficient is also calculated and the resonance frequency is estimated as 706 Hz.publishe

Noncommutative Quantum Mechanics and rotating frames

We study the effect of noncommutativity of space on the physics of a quantum interferometer located in a rotating disk in a gauge field background. To this end, we develop a path-integral approach which allows defining an effective action from which relevant physical quantities can be computed as in the usual commutative case. For the specific case of a constant magnetic field, we are able to compute, exactly, the noncommutative Lagrangian and the associated shift on the interference pattern for any value of $\theta$.Comment: 17 pages, presentation improved, references added. To appear in Physical Review

Continuous demagnetization assessment for triple redundant 9-phase fault-tolerant permanent magnet machine

In this study, the risk of partial irreversible demagnetisation of a triple redundant, nine-phase fault tolerant machine based on permanent-magnet-assisted synchronous reluctance machine topology has been comprehensively assessed under various faults, including the worst case scenario when the applied voltage vector is in the opposite direction of the back electromotive force due to sensing and inverter control failure, by employing a continuous demagnetisation model. The dynamic response during fault transients and the post-demagnetisation performance, such as the demagnetisation distribution, reduction in the back EMF and torque, will also be analysed and compared

Characteristics of PM2.5 Episodes Revealed by Semi-Continuous Measurements at the Baltimore Supersite at Ponca St

Highly time-resolved measurements of PM2.5, its major constituents, particle size distributions (9 nm to 20 μ m), CO, NO/NO2, and O3, and meteorological parameters were made from February through November 2002, at the Baltimore Supersite at Ponca St. using commercial and prototype semi-continuous instruments. The average PM2.5 mass concentration during the study period was 16.9 μ g/m3 and a total of 29 PM2.5 pollution episodes, each in which 24-h averaged PM2.5 mass concentrations exceeded 30.0 μ g/m3 for one or more days, were observed. Herein, 6 of the worst episodes are discussed. During these events, PM2.5 excursions were often largely due to elevations in the concentration of one or two of the major species. In addition, numerous short-term excursions were observed and were generally attributable to local sources. Those in OC, EC, nitrate, CO, and NOx levels were often observed in the morning traffic hours, particularly before breakdown of nocturnal inversions. Moreover, fresh accumulation aerosols from local stationary combustion sources were observed on several occasions, as evidenced by elevations in elemental markers when winds were aligned with sources resulting in PM2.5 increments of ∼ 17 μ g/m3. Overall, the results described herein show that concentrations of PM2.5 and its major constituents vary enormously on time scales ranging from < 1 hr to several days, thus imposing a more highly complex pattern of pollutant exposure than can be captured by 24-hr integrated methods, alone. The data suggest that control of a limited number of local sources might achieve compliance with daily and annual PM2.5 standards