Showing papers by "Thapar University published in 2009"
TL;DR: In this paper, an overview of the use of metakaolin as partial replacement of cement in mortar and concrete is presented, and properties reported in this paper are the fresh mortar/concrete properties, mechanical and durability properties.
623 citations
TL;DR: In this paper, a review on the phenomenon of surface modification by electric discharge machining and future trends of its applications is presented, with particular emphasis on the potential of this process for surface modification.
432 citations
TL;DR: It is suggested that calcite production by the mutant through biomineralization processes is highly effective and may provide a useful strategy as a sealing agent for filling the gaps or cracks and fissures in any construction structures.
Abstract: Phenotypic mutants of Sporosarcina pasteurii (previously known as Bacillus pasteurii) (MTCC 1761) were developed by UV irradiation to test their ability to enhance urease activity and calcite production. Among the mutants, Bp M-3 was found to be more efficient compared to other mutants and wild-type strain. It produced the highest urease activity and calcite production compared to other isolates. The production of extracellular polymeric substances and biofilm was also higher in this mutant than other isolates. Microbial sand plugging results showed the highest calcite precipitation by Bp M-3 mutant. Scanning electron micrography, energy-dispersive X-ray and X-ray diffraction analyses evidenced the direct involvement of bacteria in CaCO3 precipitation. This study suggests that calcite production by the mutant through biomineralization processes is highly effective and may provide a useful strategy as a sealing agent for filling the gaps or cracks and fissures in any construction structures.
289 citations
TL;DR: It is demonstrated that microbial calcite acts as a sealing agent for filling the gaps or cracks and fissures in constructed facilities and natural formations alike.
Abstract: Microbiologically induced calcite precipitation by the bacterium Sporosarcina pasteurii (NCIM 2477) using the industrial effluent of the dairy industry, lactose mother liquor (LML) as growth medium was demonstrated for the first time in this study. The urease activity and the calcite precipitation by the bacterium was tested in LML and compared with the standard media like nutrient media and yeast extract media. Calcite constituted 24.0% of the total weight of the sand samples plugged by S. pasteurii and urease production was found to be 353 U/ml in LML medium. The compressive strength of cement mortar was increased by S. pasteurii in all the media used compared to control. No significant difference in the growth, urease production and compressive strength of mortar among the media suggesting LML as an alternative source for standard media. This study demonstrates that microbial calcite acts as a sealing agent for filling the gaps or cracks and fissures in constructed facilities and natural formations alike.
248 citations
TL;DR: In this article, the authors evaluate the mechanical properties of concrete mixtures in which fine aggregate (regular sand) was partially replaced with used-foundry sand (UFS) by weight.
218 citations
TL;DR: The decolorization potential of two bacterial consortia developed from a textile wastewater treatment plant showed that among the two mixed bacterial culture SKB-II was the most efficient in decolorizing individual as well as mixture of dyes.
189 citations
TL;DR: An experimental study to investigate the effects of cutting parameters on finish and power consumption by employing Taguchi techniques found a significant effect of cutting speed on the surface roughness andPower consumption, while the other parameters did not substantially affect the responses.
Abstract: The present paper outlines an experimental study to investigate the effects of cutting parameters on finish and power consumption by employing Taguchi techniques. The high speed machining of AISI 1045 using coated carbide tools was investigated. A combined technique using orthogonal array and analysis of variance was employed to investigate the contribution and effects of cutting speed, feed rate and depth of cut on three surface roughness parameters and power consumption. The results showed a significant effect of cutting speed on the surface roughness and power consumption, while the other parameters did not substantially affect the responses. Thereafter, optimal cutting parameters were obtained.
180 citations
TL;DR: In this article, the authors established the ODE treatment model with two infective stages and introduced a discrete time delay to the model to describe the time from the start of treatment in the symptomatic stage until treatment effects become visible.
162 citations
TL;DR: In this article, the effect of elevated temperature on the permeability of high-performance concrete was investigated by applying a heating-cooling cycle on cylindrical samples with a maximum test temperature of either 200 or 600°C.
124 citations
TL;DR: A ground level study was deliberated to analyze the contribution of wheat and rice crop stubble burning practices on concentration levels of aerosol, SO2 and NO2 in ambient air at five different sites in and around Patiala city covering agricultural, commercial and residential areas as discussed by the authors.
123 citations
TL;DR: The present study envisages the performance of a laboratory scale electrocoagulation system for the removal of Cr(VI) from 100 mg l(-1) solution using Al-Al electrodes with an effective surface area of 100 cm(2), and placed 15 mm apart.
TL;DR: Three aerobic bacterial consortia developed from pesticide-contaminated soils of Punjab were able to degrade chlorpyrifos after 21 days of incubation in basal medium by 54, 46, and 61% and chlorp Pyrifos in soil after 30 days by 50, 56, and 64%.
Abstract: Three aerobic bacterial consortia, AC, BC, and DC, developed from pesticide-contaminated soils of Punjab were able to degrade chlorpyrifos after 21 days of incubation in basal medium by 54, 46, and 61% and chlorpyrifos (50 mg/L) in soil after 30 days by 50, 56, and 64%. Pseudomonas aeruginosa, Bacillus cereus, Klebsiella sp., and Serratia marscecens obtained from these consortia showed 84, 84, 81, and 80% degradation of chlorpyrifos (50 mg/L) in liquid medium after 20 days and 92, 60, 56, and 37% degradation of chlorpyrifos (50 mg/L) in soil after 30 days. Populations of Bacillus cereus, Klebsiella sp., and Serratia marscecens remained steady in soil experiments except for P. aeruginosa, where the population showed a substantial increase. Formation of 3,5,6-trichloro-2-pyridinol, the major metabolite of chlorpyrifos degradation, was observed during the degradation of chlorpyrifos by P. aeruginosa, which disappeared to negligible amounts.
TL;DR: Controlled low-strength material (CLSM) is a self-compacted, cementitious material used primarily as backfill in lieu of compacted fill, and is also known as flowable fill, unshrinkable fill and flowable mortar as discussed by the authors.
Abstract: Controlled low-strength material (CLSM) is a self-compacted, cementitious material used primarily as backfill in lieu of compacted fill. It is also known as flowable fill, unshrinkable fill, controlled density fill, and flowable mortar. ACI 229R defines it as materials that result in a compressive strength of 8.3 MPa or less at 28 days. CLSM is generally used in backfills, structural fills, conduit bedding, erosion control, void filling, etc. Use of several waste materials and by-products such as coal combustion products (fly ash, bottom ash), spent foundry sand, cement kiln dust, wood ash, and scrap tire rubber have been used in making controlled low-strength material. This paper presents an overview of the work published on CLSM made with coal combustion products (fly ash, bottom ash), spent foundry sand, wood ash, cement kiln dust and scrap tire rubber.
TL;DR: The results show that ectomycorrhizal fungi encode different MTs and that each of them has a particular pattern of expression, suggesting that they play critical specific roles in improving the survival and growth of ectomy Corrhiza trees in ecosystems contaminated by heavy metals.
Abstract: Metallothioneins (MTs) are small cysteine-rich peptides involved in metal homeostasis and detoxification. We have characterized two MT genes, HcMT1 and HcMT2, from the ectomycorrhizal fungus Hebeloma cylindrosporum in this study. Expression of HcMT1 and HcMT2 in H. cylindrosporum under metal stress conditions was studied by competitive reverse transcription-PCR analysis. The full-length cDNAs were used to perform functional complementation in mutant strains of Saccharomyces cerevisiae. As revealed by heterologous complementation assays in yeast, HcMT1 and HcMT2 each encode a functional polypeptide capable of conferring increased tolerance against Cd and Cu, respectively. The expression levels of HcMT1 were observed to be at their maximum at 24 h, and they increased as a function of Cu concentration. HcMT2 was also induced by Cu, but the expression levels were lower than those for HcMT1. The mRNA accumulation of HcMT1 was not influenced by Cd, whereas Cd induced the transcription of HcMT2. Zn, Pb, and Ni did not affect the transcription of HcMT1 or of HcMT2. Southern blot analysis revealed that both of these genes are present as a single copy in H. cylindrosporum. While the promoters of both HcMT1 and HcMT2 contained the standard stress response elements implicated in the metal response, the numbers and varieties of potential regulatory elements were different in these promoters. These results show that ectomycorrhizal fungi encode different MTs and that each of them has a particular pattern of expression, suggesting that they play critical specific roles in improving the survival and growth of ectomycorrhizal trees in ecosystems contaminated by heavy metals.
TL;DR: In this paper, the progression of corrosion of steel in concrete after it has been treated with surface bonded fiber-reinforced polymer (FRP) composites is investigated, where glass and carbon FRP sheets have been adhesively bonded on the cylinders.
TL;DR: A comprehensive review of the literature on the flow of various refrigerants through the capillary tubes of different geometries viz. straight and coiled and flow configurations viz. adiabatic and diabatic, has been discussed in this paper.
TL;DR: In this article, splat quenching technique was used to investigate the effect of M 2 O 3 on their bioactivity, structural and optical properties, and the results showed that the change in composition affects the crosslink formation in the glass matrix and finally its durability and bioactivity in SBF.
01 Jan 2009
TL;DR: A brain tumor segmentation method has been developed and validated on 2D & 3D MRI Data that can segment a tumor provided that the desired parameters are set properly and does not require any initialization inside the tumor.
Abstract: Segmentation of anatomical regions of the brain is the fundamental problem in medical image analysis. While surveying the literature, it has been found out that no work has been done in segmentation of brain tumor by using watershed in MATLAB Environment. In this paper, a brain tumor segmentation method has been developed and validated segmentation on 2D & 3D MRI Data. This method can segment a tumor provided that the desired parameters are set properly. This method does not require any initialization while the others require an initialization inside the tumor. The visualization and quantitative evaluations of the segmentation results demonstrate the effectiveness of this approach. In this study, after a manual segmentation procedure the tumor identification, the investigations has been made for the potential use of MRI data for improving brain tumor shape approximation and 2D & 3D visualization for surgical planning and assessing tumor. Surgical planning now uses both 2D & 3D models that integrate data from multiple imaging modalities, each highlighting one or more aspects of morphology or functions. Firstly, the work was carried over to calculate the area of the tumor of single slice of MRI data set and then it was extended to calculate the volume of the tumor from multiple image MRI data set.
TL;DR: Artificial Neural Network based approach to assess the reusability of software component will help developers to select the best component in terms of its reusabilities, which will improve the maintainability of the overall system.
Abstract: Software reuse has been used as a tool to reduce the development cost and time of the software. Nowadays, in fact, majority of software systems are being developed from an assembly of existing reusable components. In order to assess the reuse of components effectively, it is necessary to measure the reusability of these components. Paper proposes Artificial Neural Network based approach to assess the reusability of software component. This work will help developers to select the best component in terms of its reusability, which will improve the maintainability of the overall system.
TL;DR: Theoretical and numerical results suggest that decreasing the basic reproduction number below one is insufficient for disease eradication.
TL;DR: In this article, the authors investigated the effects of different operating conditions on the removal of hexavalent chromium (Cr) onto mixed cultures of Pseudomonas aeruginosa and Bacillus subtilis (MCOPAABS) using biosorption processes.
Abstract: In the present study, response surface methodology (RSM) was employed to investigate the effects of different operating conditions on the removal of hexavalent chromium (Cr (VI)) onto mixed cultures of Pseudomonas aeruginosa and Bacillus subtilis (MCOPAABS) using biosorption processes. Box-Behnken design (BBD) was used for optimization of the biosorption process and to evaluate the effects and interactions of the process variables, i. e., biomass concentration, pH, temperature and contact time on the removal of Cr (VI). A synthetic aqueous solution with a Cr (VI) concentration of 10 mg/L was used in the experimental study as a fixed input variable. The optimum conditions for maximum uptake (1.44 mg/g) of Cr (VI) onto the biosorbent were established as 0.5 g/L biosorbent dosage, pH 2 for the aqueous solution, 32°C temperature and 23 min contact time.
TL;DR: The potential of the environment to yield organisms that can produce functional bionanominerals is demonstrated by selenium-tolerant, aerobic bacteria isolated from a seleniferous rhizosphere soil and this Bacillus species has the potential to be used both in the neutralizing of toxic Se(IV) anions in the environment and in the environmentally friendly manufacture of nanomaterials.
Abstract: The potential of the environment to yield organisms that can produce functional bionanominerals is demonstrated by selenium-tolerant, aerobic bacteria isolated from a seleniferous rhizosphere soil. An isolate, NS3, was identified as a Bacillus species (EU573774.1) based on morphological and 16S rRNA characterization. This strain reduced Se(IV) under aerobic conditions to produce amorphous α Se(0) nanospheres. A room-temperature washing treatment was then employed to remove the biomass and resulted in the production of clusters of hexagonal Se(0) nano-rods. The Se(0) nanominerals were analyzed using electron microscopy and X-ray diffraction techniques. This Bacillus isolate has the potential to be used both in the neutralizing of toxic Se(IV) anions in the environment and in the environmentally friendly manufacture of nanomaterials.
TL;DR: In this paper, the global stability of a dengue epidemic model with saturation and bilinear incidence was investigated and it was shown that if R 0 is less than one, the disease-free equilibrium is globally asymptotically stable and in such a case the endemic equilibrium does not exist.
Abstract: The paper investigates the global stability of a dengue epidemic model with saturation and bilinear incidence. The constant human recruitment rate and exponential natural death, as well as vector population with asymptotically constant population, are incorporated into the model. The model exhibits two equilibria, namely, the disease-free equilibrium and the endemic equilibrium. The stability of these two equilibria is controlled by the threshold number R 0 . It is shown that if R 0 is less than one, the disease-free equilibrium is globally asymptotically stable and in such a case the endemic equilibrium does not exist; if R 0 is greater than one, then the disease persists and the unique endemic equilibrium is globally asymptotically stable.
TL;DR: In the Nawanshahr-Hoshiarpur region of Punjab, India, more than 1000 hectares of agricultural land is significantly affected by high levels of selenium (Se) as discussed by the authors.
Abstract: In the Nawanshahr–Hoshiarpur region of Punjab, India, more than 1000 hectares of agricultural land is significantly affected by high levels of selenium (Se). Studies were carried out to examine Se levels in soil and crops such as wheat grains, wheat husk, rice, maize and mustard using neutron activation analysis. The Se concentrations in soil and crop products were found to be ranging from 2.7 to 6.5 mg kg−1 and 13 to 670 mg kg−1, respectively, indicating significantly high selenium in these crop products. Two reference materials were analysed for Se contents by INAA as controls.
01 Jan 2009
TL;DR: In this paper, the authors introduce the concept of fractals and provide a study and implementation of rapidly growing field of fractal antenna engineering including recent developments, and simulated results for Koch fractal antennas using AWAS and NEC.
Abstract: Wireless applications, particularly with multiple resonances, put new demands on antennas pertaining to size, gain, efficiency, bandwidth, and more. One promising approach in this regard is to use fractal geometries to find the best distribution of currents within a volume to meet a particular design goal. In the miniaturization of wire antennas it has been found that the electromagnetic coupling between wire angles limits the reduction of the resonant frequency with increasing wire length. Recent efforts by several researchers around the world to combine fractal geometry with electromagnetic theory have led to an emergence of new and innovative antenna designs. Unique properties of fractals have been exploited to develop a new class of antenna-element designs that are multi-band and compact in size and have been shown to possess several highly desirable properties, including multi-band performance, low sidelobe levels, and its ability to develop rapid beamforming algorithms based on the recursive nature of fractals. The purpose of this paper is to introduce the concept of the fractals and to provide a study and implementation of rapidly growing field of fractal antenna engineering including recent developments. The simulated results for Koch fractal antenna using AWAS and NEC are also provided.
06 Mar 2009
TL;DR: The paper gives the guideline to choose a best suitable hashing method hash function for a particular problem and presents six suitable various classes of hash functions in which most of the problems can find their solution.
Abstract: The paper gives the guideline to choose a best suitable hashing method hash function for a particular problem. After studying the various problem we find some criteria has been found to predict the best hash method and hash function for that problem. We present six suitable various classes of hash functions in which most of the problems can find their solution. Paper discusses about hashing and its various components which are involved in hashing and states the need of using hashing for faster data retrieval. Hashing methods were used in many different applications of computer science discipline. These applications are spread from spell checker, database management applications, symbol tables generated by loaders, assembler, and compilers. There are various forms of hashing that are used in different problems of hashing like Dynamic hashing, Cryptographic hashing, Geometric hashing, Robust hashing, Bloom hash, String hashing. At the end we conclude which type of hash function is suitable for which kind of problem.
TL;DR: In this article, Fourier-Transform Infrared Spectroscopy (FTIR) was used to determine the rate of hydroxyl carbonate apatite layer formation on the surface of exposed glass samples.
TL;DR: In this paper, the authors proposed to identify critical gaps in the existing framework for mutual funds and further extend it to understand realizing the need of redesigning existing mutual fund services by acknowledging investor-oriented service quality arrangement (IOSQA) in order to comprehend investor's behavior while introducing any financial innovations.
Abstract: Financial markets are constantly becoming more efficient by providing more promising solutions to the investors. Being a part of financial markets although mutual funds industry is responding very fast by understanding the dynamics of investor’s perception towards rewards, still they are continuously following this race in their endeavor to differentiate their products responding to sudden changes in the economy. Thus, it is high time to understand and analyze investor’s perception and expectations, and unveil some extremely valuable information to support financial decision making of mutual funds. Financial markets are becoming more exhaustive with financial products seeking new innovations and to some extent innovations are also visible in designing mutual funds portfolio but these changes need alignment in accordance with investor’s expectations. Thus, it has become imperative to study mutual funds from a different angle, i.e, to focus on investor’s expectations and uncover the unidentified parameters that account for their dissatisfaction. Present research proposes to identify critical gaps in the existing framework for mutual funds and further extend it to understand realizing the need of redesigning existing mutual fund services by acknowledging Investor Oriented Service Quality Arrangements (IOSQA) in order to comprehend investor’s behavior while introducing any financial innovations.
TL;DR: The role of deformation and orientations of nuclei in cluster decays of various radioactive nuclei, particularly those decaying to doubly closed shell, spherical daughter nucleus was studied for the first time in this paper.
Abstract: The role of deformations and orientations of nuclei is studied for the first time in cluster decays of various radioactive nuclei, particularly those decaying to doubly closed shell, spherical $^{208}\mathrm{Pb}$ daughter nucleus. Also, the significance of using the correct $Q$-value of the decay process is pointed out. The model used is the preformed cluster model (PCM) of Gupta and collaborators [R. K. Gupta et al., Proc. Int. Conf. on Nuclear Reactions Mechanisms, Varenna, 1988, p. 416; Phys. Rev. C 39, 1992 (1989); 55, 218 (1997); Heavy Elements and Related New Phenomena, edited by W. Greiner and R. K. Gupta, World Sc. 1999, Vol. II, p. 731]. In this model, cluster emission is treated as a tunneling of the confining interaction barrier by a cluster considered already preformed with a relative probability ${P}_{0}$. Since both the scattering potential and potential energy surface due to the fragmentation process in the ground state of the parent nucleus change significantly with the inclusion of deformation and orientation effects, both the penetrability $P$ and preformation probability ${P}_{0}$ of clusters change accordingly. The calculated decay half-lives for all the cluster decays investigated here are generally in good agreement with measured values for the calculation performed with quadrupole deformations ${\ensuremath{\beta}}_{2}$ alone and ``optimum'' orientations of cold elongated configurations. In some cases, particularly for $^{14}\mathrm{C}$ decay of Ra nuclei, the inclusion of multipole deformations up to hexadecapole ${\ensuremath{\beta}}_{4}$ is found to be essential for a comparison with data. However, the available ${\ensuremath{\beta}}_{4}$-values, particularly for nuclei in the mass region $16\ensuremath{\leqslant}A\ensuremath{\leqslant}26$, need be used with caution.
TL;DR: In this article, the results of an experimental investigation carried out to predict the behaviour of concrete intended for nuclear applications were presented and interesting conclusions were drawn about the thermal stability at high temperature and the residual mechanical properties of the tested concrete.