Development of a creep data base management system for engineering materials

A fully menu driven creep data base management system has been developed for various high temperature materials using the client /server (C/S) architecture with Sybase system. 10 as backend and power builder 4.0 as an inter-face. The relational data base constitutes of various classes of materials, their heat treatment, prior history and the related creep properties at different test condit-ions, in addition to the source process route and chemical composition details.Top-down approach has been adopted in designing the entity-relationship (E-R) model. The creep data is organized into the third normal form, and the entire system is divided into manageable modules. Coding for the system is done using Transact-SQL for data defin- ition, manipulation and control operations, and power script language for application development. This article briefly outlines the formulation of data base design, and the implemented E-R model, in addition , to the prese-ntation of various screen formats used for data entry and retrieval modules

Estimation of Measures in M/m/1 Queue

Maximum likelihood and uniform minimum variance unbiased estimators of steady-state probability distribution of system size, probability of at least ℓ customers in the system in steady state, and certain steady-state measures of effectiveness in the M/M/1 queue are obtained/derived based on observations on X, the number of customer arrivals during a service time. The estimators are compared using Asympotic Expected Deficiency (AED) criterion leading to recommendation of uniform minimum variance unbiased estimators over maximum likelihood estimators for some measures

Stereoselective synthesis of cis- and trans-bicyclo [6.3.0] undec-4-en-10-ones. Efficient precursors of 4-oxo-1,2-cyclopentane dipropanoic acids

Short syntheses of title compounds from cheap, readily available cis, cis-1,5-cyclooctadiene are described

SEPIC Converter based-Drive for Unipolar BLDC Motor

Front-end single-ended primary inductance converter (SEPIC) and a switch in series with each phase is proposed for driving a permanent magnet brushless dc (BLDC) motor with unipolar currents. All the switches are ground-referenced, which simplifies their gate drives. The available input voltage can be boosted for better current regulation, which is an advantage for low voltage applications. The SEPIC converter is designed to operate in the discontinuous conduction mode for operation with an ac supply. In this operation mode, the line current follows the line voltage waveform to a certain extent. The reduction in low-order harmonics and improved power factor is achieved without the use of any voltage or current sensors. The simplicity and reduced parts count of the proposed topology make it an attractive low-cost choice for many variable speed drive applications. The proposed topology is simulated and verified by using MATLAB/SIMULINK.DOI:http://dx.doi.org/10.11591/ijece.v2i2.30

Fault Tolerant Power Supply for Aircraft Store Interface

This paper brings out the design of a fault-tolerant power supply unit for the aircraft-store interface. This switched mode power supply provides multiple 30 V regulated and isolated DC outputs required for pre-launch preparations and auto-launch operations of avionic sub-systems in a store. 3Ø-115V-400Hz-AC supply as well as 27V-DC supply are available from a fighter aircraft for powering up of any store. Power (wattage) output from 27V/10A DC is inadequate to power up various onboard avionic sub-systems in guided stores involving seekers and other avionics. Hence, it is planned to convert available high power 3Ø-115V-400Hz-AC supply for applications requiring higher wattages (of the order of 500 watts or more). This power supply provides multiple output options of 30V regulated and isolated DC supply with multiple input supplies from Aircraft, viz. 3Ø-115V-400Hz-AC, 1Ø-115V-400Hz-AC and 27V DC. One of the outputs provided is with hold-up capacitors, to cater for any input power interruptions as per requirements of MIL-STD-704F and GOST-19705-89 standards. This power supply is a ready-to-connect device and essentially consists of housing, components of DC to DC conversions, EMI/EMC filters, solid state power controllers, control switches, and control circuitry for monitoring signals

Prevalence of neonatal candidemia in a tertiary care institution in Hyderabad, South India

Background: Candida species are known to be the most common fungal pathogens isolated from blood cultures of neonates. Recent reports from our country indicates trend towards an increasing prevalence of non-albicans candidemia. Candida species possess a number of virulence factors which enable them to cause hematogenously disseminated infections in susceptible hosts with increased morbidity and mortality. Objective of current study was to know the prevalence of nonalbicans candidemia in neonates and their antifungal susceptibility pattern. Methods:Blood samples from suspected cases of neonatal septicaemia were subjected to culture, incubated for 7 days and subcultures performed. Culture yielding pure growth of Candida were included for the study and identified by standard methodology. Antifungal susceptibility was performed.Results:A total of 255/500 (51%) cases were blood culture positive. Pure growth of Candida species was isolated from 52/255 (20.39%) cases. A total of 52 Candida isolates were obtained over a period of one year accounting for 20.39% of all neonatal septicemia cases. Among 52 isolates, 14/52 (26.92%) were Candida albicans, followed by C. tropicalis 19/52 (36.53%), C. glabrata 10/52 (19.23%), C. parapsilosis 4/52 (7.69%), C. guillermondii 2/52 (3.84%) and C. krusei 1/52 (1.92%). C. tropicalis, the most common species isolated, was 91 per cent susceptible to fluconazole, whereas C. parapsilosis and C. glabrata showed lower sensitivity rates of 67.8% and 62.5% respectively.Conclusion:In this study non albicans candida was the common isolate & they showed decreased resistance to Fluconazole. In neonatal septicemia speciation& antifungal susceptibility may help in management.

Droplet impact on immiscible liquid pool: Multi-scale dynamics of entrapped air cushion at short timescales

We have detected unique hydrodynamic topology in thin air film surrounding the central air dimple formed during drop impact on an immiscible liquid pool. The pattern resembles spinodal and finger-like structures typically found in various thin condensed matter systems. However, similar structures in thin entrapped gas films during drop impacts on solids or liquids have not been reported to date. The thickness profile and the associated dewetting dynamics in the entrapped air layer are investigated experimentally and theoretically using high-speed reflection interferometric imaging and linear stability analysis. We attribute the formation of multiscale thickness perturbations, associated ruptures, and finger-like protrusions in the draining air film as a combined artifact of thin-film and Saffman-Taylor instabilities. The characteristic length scales depend on the impact Weber number, the ratio of the liquid pool to droplet viscosity, and the ratio of air-water to air-oil surface tension

DETERMINATION OF 2-CYANO-4'-BROMOMETHYL BIPHENYL GENOTOXIC IMPURITY IN IRBESARTAN DRUG SUBSTANCES USING HPLC TECHNIQUE

Objective: The objective of present study was to develop and validate a specific and sensitive HPLC method for the quantitative determination of genotoxic impurity 2-cyano-4'-bromomethyl biphenyl present in irbesartan drug substance.Methods: The development activity was conducted by HPLC with UV as a detector. The impurity was separated on Kromasil C18 250 x 4.6 mm, 5 µm analytical column with a mobile phase consisting of buffer pH 3.2 and acetonitrile in the ratio of 60:40 v/v at a flow rate 1.5 ml/min. The effluent was monitored by UV detection at 258 nm with column temperature maintained at 40 °C and the injection volume 30 μl. Acetonitrile was selected as diluent.Results: Validation activity was planned and completed based on the ICH guideline. The LOD and LOQ value were found to be 0.167 µg/g and 0.506 µg/g and accuracy results were well in the range 98.34 to 103.46 %. The linearity curve showed the correlation coefficient of 0.9999 and method very sensitive.Conclusion: From validation data, it was confirmed that the developed method is specific, sensitive, linear, precise and accurate for the determination of 2-cyano-4'-bromomethyl biphenyl genotoxic impurity in irbesartan drug substances

ENHANCED TRANSDERMAL PERMEABILITY OF TELMISARTAN BY A NOVEL NANOEMULSION GEL

Objective: Telmisartan is an angiotensin II type I receptor blocker antihypertensive agent with 42% oral bioavailability. The aim of the present investigation was to develop a nanoemulsion gel to enhance bioavailability of poorly water soluble Telmisartan.Methods: Different nanoemulsion components (oil, surfactant and co-surfactant) were selected on the basis of solubility and emulsification ability. Pseudotemary phase diagrams were constructed using aqueous titration method. Carbopol 934 was added as a gel matrix to convert nanoemulsion into nanoemulsion gel. Drug loaded nanoemulsions and nanoemulsion gels were characterized for particle size, viscosity, rheological behavior, thermodynamic stability studies and ex vivo permeation studies using rat skin. Transdermal permeation of Telmisartan from nanoemulsion gels was determined using Franz Diffusion cell.Results: The optimized nanoemulsion gel (NEG) contained Labrafil®M 2125 CS (14.3%) as oil, Acrysol®EL 135 (30.84%) as surfactant, Carbitol® (15.42%) as co-surfactant and (32.44%) water; 20 mg drug and 1% w/w carbopol. The ex vivo permeation profile of optimized formulation was compared to nanoemulsion and normal gel. Permeability parameters like steady-state flux (Jss), permeability coefficient (Kp), and enhancement ratio (Er) were significantly increased in nanoemulsion (NE) and nanoemulsion gel (NEG) as compared to conventional gel. There was a considerable improvement in bio availability for nanoemulsion gel compared to the conventional telemisartan gel.Conclusion: Nanoemulsion gel has significantly increased the bio-availability of the drug.Â