Showing papers by "Thapar University published in 2007"

Prevalence of enterotoxigenic Staphylococcus aureus and Shigella spp. in some raw street vended Indian foods.

Abstract: In India, the street food trade is a growing sector with its expansion linked with urbanisation and the need of urban populations for both employment and food. However, the microbiological status of popularly consumed raw street foods, general hygienic and vending practices are not known. We visited 75 vendors (50 having fixed stalls and 25 with mobile stalls) operating in three major locations: mandi (open market place), bus terminus and railway station in New Delhi and Patiala City. A total of 150 samples each of coriander sauce, of ready-to-eat salads and coconut slices collected were analysed for Staphylococcus aureus and Shigella spp. Enterotoxigenic Staphylococcus aureus were detected in 91 (60%) samples of coriander sauce, 87 (58%) samples of coconut slices and 129 (86%) samples of ready-to-eat salads. Twenty-three (15%) samples of coconut slices contained Shigella (18 Sh. dysenteraie type 1 and 5 Sh. flexneri 2a), 13 (8%) samples of ready-to-eat salads and 10 (6%) samples of coriander sau...

Phosphate solubilization by a wild type strain and UV-induced mutants of Aspergillus tubingensis

Abstract: Phenotypic mutants of Aspergillus tubingensis were obtained by UV irradiation and phosphate solubilization ability of these mutants were studied and compared with the wild type strain. Low phosphate solubilizing mutant was also selected in this study. Among the different mutants, AtM-5 and AtM-2 showed highest P solubilization when tri-calcium phosphate and rock phosphate were used as P source compared to the wild type strain and other mutants. These mutants also showed maximum acid phosphatase and phytase activity. These results suggest that P solubilization by these isolates is due to lowering of pH of the culture filtrate and also the activity of acid phosphatase and phytase.

Toxic environmental releases from medical waste incineration: a review.

Abstract: Toxic releases from medical waste incineration comprising organic emissions such as polychlorinated dibenzo-dioxin/furan (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs), inorganic emissions and ashes containing toxic metals have been reviewed. Attempts made by various investigators to reduce/eliminate emissions have also been included. Legislations concerning emission standards for medical waste incinerators have been discussed.

Effect of Y2O3 on the crystallization behavior of SiO2–MgO–B2O3–Al2O3 glasses

Abstract: A series of glass comprising of SiO2–MgO–B2O3–Y2O3–Al2O3 in different mole ratio has been synthesized. The crystallization kinetics of these glasses was investigated using various characterization techniques such as differential thermal analysis (DTA), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Crystallization behavior of these glasses was markedly influenced by the addition of Y2O3 instead of Al2O3. Addition of Y2O3 increases the transition temperature, T g, crystallization temperature, T c and stability of the glasses. Also, it suppresses the formation of cordierite phase, which is very prominent and detrimental in MgO-based glasses. The results are discussed on the basis of the structural and chemical role of Y3+ and Al3+ ions in the present glasses.

Prediction of first lactation 305-day milk yield in Karan Fries dairy cattle using ANN modeling

Abstract: In this paper, an artificial neural network (ANN) model is proposed to predict the first lactation 305-day milk yield (FLMY305) using partial lactation records pertaining to the Karan Fries (KF) crossbred dairy cattle. A scientifically determined optimum dataset of representative breeding traits of the cattle is used to develop the model. Several training algorithms, viz., (i) gradient descent algorithm with adaptive learning rate; (ii) Fletcher-Reeves conjugate gradient algorithm; (iii) Polak-Ribiere conjugate gradient algorithm; (iv) Powell-Beale conjugate gradient algorithm; (v) Quasi-Newton algorithm with Broyden, Fletcher, Goldfarb, and Shanno (BFGS) update; and (vi) Levenberg-Marquardt algorithm with Bayesian regularization; along with various network architectural parameters, i.e., data partitioning strategy, initial synaptic weights, number of hidden layers, number of neurons in each hidden layer, activation functions, regularization factor, etc., are experimentally investigated to arrive at the best model for predicting the FLMY305. Also, a multiple linear regression (MLR) model is developed for the milk-yield prediction. The performances of ANN and MLR models are compared to assess the relative prediction capability of the former model. It emerges from this study that the performance of ANN model seems to be slightly superior to that of the conventional regression model. Hence, it is recommended that the ANNs can potentially be used as an alternative technique to predict FLMY305 in the KF cattle.

Analysis of reliability and availability of serial processes of plastic‐pipe manufacturing plant

Abstract: Purpose – The purpose of this paper is to compute reliability, availability, and mean time before failure of the process of a plastic‐pipe manufacturing plant consisting of a (K, N) system for various choices of failure and repair rates of sub‐systems. This plant consists of eight sub‐systems.Design/methodology/approach – In this paper the Chapman‐Kolmogorov differential equations are formed using mnemonic rule from the transition diagram of the plastic‐pipe manufacturing plant. The governing differential equations are solved using matrix method in order to find the reliability of the system with the help of MATLAB software. The same system of differential equations is solved numerically using Runge‐Kutta fourth order method to validate the results obtain by MATLAB.Findings – The findings in the paper are an analysis of reliability, availability and mean time before failure of plastic‐pipe manufacturing plant has been carried out.Practical implications – This paper proposes matrix calculus method using MA...

Podophyllotoxin content in Podophyllum hexandrum Royle plants of known age of seed origin and grown at a lower altitude

Abstract: Podophyllum hexandrum Royle, an important alpine herb, and a source of the highly valued aryltetralin-type lignan, podophyllotoxin, has been subjected to heavy collection from the wild due to ever increasing demand. The present study deals with an attempt to bring this plant under cultivation at a relatively lower altitude and to evaluate (1) various growth parameters including above and below ground biomass accumulation, net assimilation rate and relative growth rate, etc., and (2) podophyllotoxin content from the resulting above and below ground biomass in seed raised plants of a known age series of 1–5 years. The podophyllotoxin content was estimated on the basis of HPLC analyses. The levels were found to increase with the plant age and the maximum amount was found in 5-year old plants. This study demonstrates that (1) seeds can be conveniently used for raising healthy propagules in easily approachable locations at a relatively lower altitude, and that the plants can be maintained in such sites over long periods, and (2) this approach of “conservation through cultivation” can be suggested as an effective tool for the management of this “critically endangered status” species.

Anti-staphylococcal potential of Callistemon rigidus

Abstract: The last decade witnessed the emergence of Staphylococcus aureus- a versatile human pathogen, as a deadly superbug. The enormous genetic plasticity of the organism assists it to endlessly evolve resistance mechanisms against existing anti-infectives thus necessitating the need to control the spread of resistant staphylococcal isolates in hospitals and health care settings. This in turn demands the incessant exploration of newer biological matrices in search of diverse chemical entities with novel drug targets. Since time immemorial higher plants continue to be the best source of newer compounds with high therapeutic potential. Lead fractions from same or different plants can be developed into effective antibacterial polyherbal formulations. A lead fraction from methanolic extract of leaves of Callistemon rigidus exhibited a dose dependent antistaphylococcal activity during in vitro agar well assay against a panel of twenty seven clinical multidrug resistant S. aureus isolates. Further, minimal inhibitory concentration (MIC) evaluation by in vitro 96-well microplate based assay established a MIC range of 1.25–80 μg/ml as compared to 5–320 μg/ml of positive control, Cefuroxime sodium. The MIC50 and MIC90 of the methanolic lead fraction were 5 μg/ml and 40 μg/ml respectively. The present study thus signifies the vast potential of the lead fraction from Callistemon rigidus for future development into a herbal drug/ formulation and to impede global health crisis due to multidrug resistant Staphylococcus aureus.

Thermal Chlorophyll Degradation Kinetics of Mint Leaves Puree

Abstract: Thermal degradation kinetics of chlorophyll ‘a’, ‘b’ and total chlorophyll in mint leaves puree were investigated as function of pH (4.5–8.5) and processing temperature (80–145°C), respectively. Mint puree was processed at 80°to 100°C at pH 4.5, while that at pH 5.5 to 8.5 was processed at 105°to 145°C. Chlorophyll degradation followed the first order reaction kinetics. Good agreement was found between estimated and experimental chlorophyll retention in all cases (R2 > 0.86; MRQE < 0.27). Activation energies ranged from 6.45 to 47.67 kJ/mol. Reaction rate and activation energy data indicated that chlorophylls were more stable at alkaline pH. Transition state theory was applied to estimate the enthalpy, entropy and Gibbs free energy of activation. Enthalpy (ΔH#) ranged from 3.14 to 44.66 kJ/mol, while entropy (ΔS#) ranged from −0.157 to −0.266 kJ/(mol K). The overall free energy change was 105.76 kJ/mol. Results indicated that, the compensation effect did not exist for chlorophyll degradation in mint puree...

Soluble Borate Glasses: In Vitro Analysis

Abstract: In vitro bioactivity of borate glasses with composition xNa2O·xCaO·2xB2O3 (where x is in wt%=24.8, 24.2, 23.8, 23.2) containing 0, 2, 4, 6 wt% P2O5 has been investigated by soaking them in a simulating body fluid (SBF) up to 15 days at 37°C. Investigation of glass degradation is carried out by taking percentage weight loss in SBF and by measuring the pH of SBF as a function of time. Inductively coupled plasma emission spectroscopy is used to study the ionic concentration of BIII, CaII, and NaI ions in SBF after 15 days of assay. Fourier transform infrared spectra are taken before and after dipping in SBF for structural analysis and for confirmation of hydroxyl carbonate apatite layer formation in SBF after 15 days. The results show that P2O5 plays an important role in controlling chemical durability and bioactivity. A borate glass with the same composition as 45S5 bioglass prepared by Hench but with SiO2 replaced by B2O3 in weight percentage has been prepared for comparison of bioactivity for the two.

A Study of Different Kinds of Degradation in Printed Gurmukhi Script

Abstract: The performance of any OCR system heavily depends upon printing quality of the input document. Many OCRs have been designed which correctly identify fine printed documents both in Indian and foreign scripts. But little reported work has been found on the recognition of the degraded documents. The performance of standard machine printed OCR system working for fine printed documents decreases, if it is tested on degraded documents. The degradation in any document can be of many types. In this paper, we have identified different kinds of degradation available in printed Gurmukhi script. After identifying the different kinds of degradation, problems associated with each kind of degradation have been discussed; some possible solutions have also been discussed. This paper is extremely useful for researchers engaged in recognizing the degraded documents in any script, because same kinds of degradation can be found in most of the scripts of the world

Damage Detection for Framed RCC Buildings using ANN Modeling

Abstract: A structure is evaluated, after an earthquake, to find out whether it is usable or requires repair and retrofitting. The natural time period, damping, and mode shape are the primary dynamic characteristics of any structure that is related to seismic forces during an earthquake event. Periodic monitoring using vibration measurements is one of the most effective nondestructive methods to identify the damage level. A significant deviation in natural frequencies or damping ratios from the undamaged states indicates the possible occurrence of damage. In the present study, the dynamic characteristics of a 2D rigid frame of a reinforced concrete building are obtained analytically under different levels of damage. Further, using an artificial neural network (ANN) model the authors have developed a correlation between the damage in the frame of the reinforced concrete building with its known dynamic characteristics. Use of such correlations for evaluating the health status of the buildings has been discussed.

Few useful considerations for maintaining software components and component-based systems

Abstract: Component-Based Systems (CBS) maintenance may require several activities different than normal applications, such as upgrading the functionality of black-box components (for which code may not be available), replacement of older version components with the new ones for better and improved functionality, tracing the problem of compatibility between the new components with system, and so on. The focus of this paper is on investigating several issues and concerns about maintainability of component-based systems. It also explores the acceptance of maintainability characteristics and sub-characteristics as defined in ISO9126 quality model for CBS. The paper proposes two new sub-characteristics, namely trackability and portability, to be included under the maintenance activity.

Mathematical Modeling of the Poly(lactic acid) Ring–Opening Polymerization Kinetics

Abstract: The modeling of ring-opening polymerization of (D,L)-lactide to poly(lactic acid) (PLA) has been performed. Except some reported data on the apparent rate constant, there is lack of data in the literature on the rate constants for initiation, propagation and termination steps of PLA polymerization. Using a simple numerical technique, the individual rate constants are evaluated theoretically and the results are compared with the available experimental data for ring-opening polymerization of PLA. The proposed method works well without requiring a polymer chain length independent rate constant. It is also shown that presence of even small amount of impurity (e.g., water) in the reaction kettle can greatly limit the polymer molecular weight.

Statistical Analysis of Experimental Parameters in Ultrasonic Machining of Tungsten Carbide Using the Taguchi Approach

Abstract: The objective of this paper is to study the influence of operating parameters of ultrasonic machining of tungsten carbide on the machining characteristics. The effectiveness of the ultrasonic machining process with tungsten carbide is evaluated in terms of the material removal rate and the surface finish quality of the work piece produced. Tungsten carbide as a super hard and high wear-resistant material has been used widely in industries. Powder metallurgy technology is the common method for producing tungsten carbide components. However, this method is obviously too costly and time consuming for small quantity production, such as product prototyping. It is expected to make the prototypes by a material removal process, such as ultrasonic machining. In this paper, an experimental study on the ultrasonic machining of tungsten carbide is presented using a systematic approach. Practical aspects are given on the characteristics of tungsten carbide as functions of the type of abrasive slurry, their size and concentration, nature of the tool material, and the power rating of the machine. The optimum combination of various input factors for the ductile chip formation in the machining of tungsten carbide has been determined by applying the Taguchi approach and the F-test.

Linkages of Technology Adoption and Adaptation with Technological Capability, Flexibility and Success of AMT Implementation in Indian Manufacturing Industry: An Empirical Study

Abstract: Technological capability represents the abilities of productive enterprises to handle industrial technologies and cope with technological change. There are many reports that deal with the technological and operational aspects of Advanced Manufacturing Technology (AMT), but the adoption and adaptation as key phase in the implementation of AMT for developing technological capabilities, achieving flexibilities and success are not paid due attention. Realizing the importance of AMT, an empirical study has been conducted in this paper with an objective to gain more insights. This research reports the findings of an exploratory study of North Indian medium and large scale manufacturing organizations, which are in the process of adopting and adapting new technologies. For achieving flexibilities and developing technological capabilities in Indian manufacturing industry, the most significant factors established through this study include Human factor in terms of their skill, technical expertise, training, involvement, attitude and Employees education. The findings suggest that such factors may be quite important to manufacturing firms trying to compete through flexibility competence and technological capabilities. The results also suggest that an organization could deploy specific practices to strengthen their technological capabilities.

Slant and semi-slant submanifolds of a kenmotsu manifold

Abstract: In the present note we have obtained some basic results pertaining to the geometry of slant and semi-slant submanifolds of a Kenmotsu manifold.

Heat Transfer Studies of a Heat Pipe

Abstract: The present investigation reports a theoretical and experimental study of a wire screen heat pipe, the evaporator section of which is subjected to forced convective heating and the condenser section to natural convective cooling in air The theoretical study deals with the development of an analytical model based on thermal resistance network approach The model computes thermal resistances at the external surface of the evaporator and condenser as well as inside the heat pipe A test rig has been developed to evaluate the thermal performance of the heat pipe The effects of operating parameters (ie, tilt angle of the heat pipe and heating fluid inlet temperature at the evaporator) have been experimentally studied Experimental results have been used to compare the analytical model The heat transfer coefficients predicted by the model at the external surface of the evaporator and condenser are reasonably in agreement with experimental results