Showing papers by "Birla Institute of Technology and Science published in 2012"

A review on mechanical behavior of natural fiber based hybrid composites

Abstract: Hybrid composites are manufactured by combining two or more fibers in a single matrix. Hybrid composites can be made from artificial fibers, natural fibers and with a combination of both artificial and natural fibers. Hybrid composites can help us to achieve a better combination of properties than fiber reinforced composites. The constituent fibers in a hybrid composite can be altered in a number of ways leading to variation in its properties. The importance of this review can be attributed to the significant aspects of natural fiber based hybrid composites which are found to be predominantly affected by factors which include variation in fiber volume/weight fraction, variation in stacking sequence of fiber layers, fiber treatment and environmental conditions.

Application of Cellulose-Clay Composite Biosorbent toward the Effective Adsorption and Removal of Chromium from Industrial Wastewater

Abstract: Biopolymer composites are known for their utility in diverse applications. In this paper, we report an effective methodology for the detoxification of chromium using cellulose-montmorillonite composite material as the adsorbent. The interaction of surfactant modified sodium montmorillonite (NaMMT) with cellulose biopolymer is followed by the subsequent adsorption of Cr(VI) from aqueous solution as bichromate anion onto the surface of the biocomposite material. The composite adsorbent was characterized comprehensively using Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD) and Branauer-Emmett-Teller (BET) isotherm studies. The material exhibited a maximum adsorption capacity of 22.2 mg g–1 in accordance with the Langmuir isotherm model. The mesoporous nature of the material was ascertained from the nitrogen adsorption isotherm study and the adsorption process was in accordance with second order kinetics. The spontaneity of the adsorption pr...

Endophytic fungi: novel sources of anticancer lead molecules

Abstract: Cancer is a major killer disease all over the world and more than six million new cases are reported every year. Nature is an attractive source of new therapeutic compounds, as a tremendous chemical diversity is found in millions of species of plants, animals, and microorganisms. Plant-derived compounds have played an important role in the development of several clinically useful anti-cancer agents. These include vinblastine, vincristine, camptothecin, podophyllotoxin, and taxol. Production of a plant-based natural drug is always not up to the desired level. It is produced at a specific developmental stage or under specific environmental condition, stress, or nutrient availability; the plants may be very slow growing taking several years to attain a suitable growth phase for product accumulation and extraction. Considering the limitations associated with the productivity and vulnerability of plant species as sources of novel metabolites, microorganisms serve as the ultimate, readily renewable, and inexhaustible source of novel structures bearing pharmaceutical potential. Endophytes, the microorganisms that reside in the tissues of living plants, are relatively unstudied and offer potential sources of novel natural products for exploitation in medicine, agriculture and the pharmaceutical industry. They develop special mechanisms to penetrate inside the host tissue, residing in mutualistic association and their biotransformation abilities opens a new platform for synthesis of novel secondary metabolites. They produce metabolites to compete with the epiphytes and also with the plant pathogens to maintain a critical balance between fungal virulence and plant defense. It is therefore necessary that the relationship between the plants and endophytes during the accumulation of these secondary metabolites is studied. Insights from such research would provide alternative methods of natural product drug discovery which could be reliable, economical, and environmentally safe.

Software Fault Prediction Using Quad Tree-Based K-Means Clustering Algorithm

Abstract: Unsupervised techniques like clustering may be used for fault prediction in software modules, more so in those cases where fault labels are not available. In this paper a Quad Tree-based K-Means algorithm has been applied for predicting faults in program modules. The aims of this paper are twofold. First, Quad Trees are applied for finding the initial cluster centers to be input to the A'-Means Algorithm. An input threshold parameter δ governs the number of initial cluster centers and by varying δ the user can generate desired initial cluster centers. The concept of clustering gain has been used to determine the quality of clusters for evaluation of the Quad Tree-based initialization algorithm as compared to other initialization techniques. The clusters obtained by Quad Tree-based algorithm were found to have maximum gain values. Second, the Quad Tree- based algorithm is applied for predicting faults in program modules. The overall error rates of this prediction approach are compared to other existing algorithms and are found to be better in most of the cases.

Comparing the performance of neural networks developed by using Levenberg-Marquardt and Quasi-Newton with the gradient descent algorithm for modelling a multiple response grinding process

Abstract: Highlights? Levenberg-Marquardt (L-M) and Boyden, Fletcher, Goldfarb and Shanno (BFGS) update Quasi-Newton (Q-N)-based BPNN networks are equally efficient as adaptive learning (A-L) algorithm-based BPNN network. ? L-M algorithm has fastest network convergence rate, followed by BFGS update Q-N and A-L algorithm. ? A-L -based BPNN learns faster than BFGS update Q-N, and L-M takes maximum time for network training. ? A-L algorithm is relatively easy-to-understand and implement, as compared to L-M or BFGS update Q-N algorithm, for online process control. Monitoring and control of multiple process quality characteristics (responses) in grinding plays a critical role in precision parts manufacturing industries. Precise and accurate mathematical modelling of multiple response process behaviour holds the key for a better quality product with minimum variability in the process. Artificial neural network (ANN)-based nonlinear grinding process model using backpropagation weight adjustment algorithm (BPNN) is used extensively by researchers and practitioners. However, suitability and systematic approach to implement Levenberg-Marquardt (L-M) and Boyden, Fletcher, Goldfarb and Shanno (BFGS) update Quasi-Newton (Q-N) algorithm for modelling and control of grinding process is seldom explored. This paper provides L-M and BFGS algorithm-based BPNN models for grinding process, and verified their effectiveness by using a real life industrial situation. Based on the real life data, the performance of L-M and BFGS update Q-N are compared with an adaptive learning (A-L) and gradient descent algorithm-based BPNN model. The results clearly indicate that L-M and BFGS-based networks converge faster and can predict the nonlinear behaviour of multiple response grinding process with same level of accuracy as A-L based network.

Design, Synthesis, and Evaluation of Thiol-Activated Sources of Sulfur Dioxide (SO2) as Antimycobacterial Agents

Abstract: Here, 2,4-dinitrophenylsulfonamides with tunable cysteine-activated SO2 release profiles with half-lives of SO2 release varying from 2 to 63 min are reported. N-Benzyl-2,4-dinitrobenzenesulfonamide (6), which is prepared in one step from commercial sources, had a potency (MIC = 0.15 μM) of inhibiting Mycobacterium tuberculosis (Mtb) higher than the clinical agent isoniazid (MIC = 0.37 μM).

Analysis of the wave properties of a new two-lane continuum model with the coupling effect

Abstract: A multilane extension of the single-lane anisotropic continuum model (GK model) developed by Gupta and Katiyar for traffic flow is discussed with the consideration of the coupling effect between the vehicles of different lanes in the instantaneous traffic situation and the lane-changing effect. The conditions for securing the linear stability of the new model are presented. The shock and the rarefaction waves, the local cluster effect and the phase transition are investigated through simulation experiments with the new model and are found to be consistent with the diverse nonlinear dynamical phenomena observed in a real traffic flow. The analysis also focuses on empirically observed two-lane phenomena, such as lane usage inversion and the density dependence of the number of lane changes. It is shown that single-lane dynamics can be extended to multilane cases without changing the basic properties of the single-lane model. The results show that the new multilane model is capable of explaining some particular traffic phenomena and is in accordance with real traffic flow.

Milk, milk products, and disease free health: an updated overview

Abstract: The cow and its milk have been held sacred in the world since the dawn of human civilization. Indian ancient Vedic texts describe the virtues of milk and dairy products, as is authenticated by modern scientific principles and proofs. Therefore, milk has been considered as one of the most natural and highly nutritive part of a daily balanced diet. Currently, the integration of advanced scientific knowledge with traditional information is gaining incredible momentum toward developing the concept of potential therapeutic foods. Furthermore, new advances toward understanding the therapeutic roles of milk and milk products have also given a new impetus for unraveling the age old secrets of milk. At present, the best-known examples of therapeutic foods are fermented milk products containing health promoting probiotic bacteria. In the present article, we have tried to review the various aspects of the therapeutic nature of milk and fermented dairy products in a highly up-dated manner, and offer an in-depth insight into the development of targeted therapeutic future foods as per the requirements of consumers.

A review of research in multi-robot systems

Abstract: Formally, a collection of two or more autonomous mobile robots working together are termed as teams or societies of mobile robots. In multi robot systems simple robots are allowed to coordinate with each other to achieve some well defined goals. In these kinds of systems robots are far less capable as an entity, but the real power lies in cooperation of multiple robots. The simplicity of multi-robots have produced a potentially wide set of applications such as military missions (battlefield surveillance), searching for survivors in disaster hit areas, parallel and simultaneous transportation of vehicles, and delivery of payloads. Although the research on multi-robot systems has attracted considerable attention worldwide in the past decade, the research in this area is still in its infancy. This paper surveys various interaction techniques in multi robot systems which are important with respect to goal attainment and task completion.

Assessment of land consumption rate with urban dynamics change using geospatial techniques

Abstract: Land consumption is increasing rapidly with the exponential growth of population. The built-up environment configuration influences the management processes for development and other municipality works. Population growth also affects the availability of land for different purposes in its spatial distribution. The present study was conducted using satellite remote sensing data Landsat MSS (Multi-spectral Scanner), ETM+ (Enhanced Thematic Mapper), IRS P-6 (Indian Remote Sensing Satellite), LISS IV (Linear Imaging Self-Scanner), and IRS P-5 Cartosat-1 for the assessment of urban area change dynamics between years 1976 and 2008 in Bhagalpur city in the state of Bihar in India. The ground truth and coordinate points were collected using a Global Positioning System (GPS) for the location of the built-up themes prepared in the Geographic Information System (GIS). Land Consumption Rate (LCR) and Land Absorption Coefficient (LAC) were introduced to aid in the quantitative assessment changes. The results show a rap...

A decision framework for maximising lean manufacturing performance

Abstract: Since the development of the original value stream mapping (VSM) by Taichi Ohno at Toyota, a number of authors have suggested several additional VSM tools to understand and improve the value stream through waste reduction. A single best VSM tool, though effective in dealing with a certain waste type, becomes redundant as other wastes take centre stage and/or organisational priorities change. To overcome this, a decision framework based on a novel formulation of the integrated analytical hierarchy process (AHP) – pre-emptive goal programming (PGP) has been proposed. This framework not only guarantees accurate selection of an ideal VSM tool, based on the current organisation's priorities, but also aids the decision maker to arrive at the optimum implementation sequence of a chosen set of VSM tools to identify and reduce all wastes present in the system, thereby maximising organisational performance in the shortest timeframe.

Bioconversion of lignocellulose-derived sugars to ethanol by engineered Saccharomyces cerevisiae

Abstract: Lignocellulosic biomass from agricultural and agro-industrial residues represents one of the most important renewable resources that can be utilized for the biological production of ethanol. The yeast Saccharomyces cerevisiae is widely used for the commercial production of bioethanol from sucrose or starch-derived glucose. While glucose and other hexose sugars like galactose and mannose can be fermented to ethanol by S. cerevisiae, the major pentose sugars D-xylose and L-arabinose remain unutilized. Nevertheless, D-xylulose, the keto isomer of xylose, can be fermented slowly by the yeast and thus, the incorporation of functional routes for the conversion of xylose and arabinose to xylulose or xylulose-5-phosphate in Saccharomyces cerevisiae can help to improve the ethanol productivity and make the fermentation process more cost-effective. Other crucial bottlenecks in pentose fermentation include low activity of the pentose phosphate pathway enzymes and competitive inhibition of xylose and arabinose transport into the cell cytoplasm by glucose and other hexose sugars. Along with a brief introduction of the pretreatment of lignocellulose and detoxification of the hydrolysate, this review provides an updated overview of (a) the key steps involved in the uptake and metabolism of the hexose sugars: glucose, galactose, and mannose, together with the pentose sugars: xylose and arabinose, (b) various factors that play a major role in the efficient fermentation of pentose sugars along with hexose sugars, and (c) the approaches used to overcome the metabolic constraints in the production of bioethanol from lignocellulose-derived sugars by developing recombinant S. cerevisiae strains.

A label-free silver wire based impedimetric immunosensor for detection of aflatoxin M1 in milk

Abstract: a b s t r a c t A highly sensitive and selective label-free impedimetric immunosensor based on silver (Ag) wire elec- trode for the detection aflatoxin M1 (AFM1) in milk is presented. The sensor was constructed by functionalizing Ag wire coupled with selective monoclonal antibodies of AFM1 through self assembled monolayers. The antigen-antibody interaction was quantified by measuring impedance in the frequency range (1-100 Hz) at 10 mV applied ac potential. A linear working range (6.25-100 pg mL −1 ) for AFM1 was obtained with 20 min analysis time. The sensor sensitivity was found to be about 2.1% impedance change per decade with limit of quantitation 6.25 pg mL −1 and limit of detection 1 pg mL −1 . Good recov- eries were obtained with SD = 1.13 and R2 = 0.982 in spiked milk samples. The proposed method is useful for sensitive analysis of AFM1 in milk.

Biosynthesis of silver nanoparticles by marine bacterium, Idiomarina sp. PR58-8

Abstract: Metal-tolerant microorganisms have been exploited in recent years to synthesize nanoparticles due to their potential to offer better size control through peptide binding and compartmentalization. In this paper, we report the intracellular synthesis of silver nanoparticles (SNPs) by the highly silver-tolerant marine bacterium, Idiomarina sp. PR58-8 on exposure to 5 mM silver nitrate. SNPs were characterized by UV-visible spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). UV-visible absorption scan of a 48 h culture exposed to 5 mM silver nitrate revealed a broad peak at 450 nm indicative of the surface plasmon resonance of SNPs. XRD analysis confirmed the presence of elemental silver and the crystallite size was calculated to be 25 nm using Scherrer formula. The average particle size as per TEM analysis was found to be 26 nm. Metal stress is known to induce the production of non-protein thiols (NP–SHs) which sequester metal ions. In this study, the production of NP–SHs was followed from 6–48 h, wherein it was observed that the NP–SH levels in the silver-exposed culture were consistently higher (261% on an average) than in the unexposed culture.

Evaluating reliability and validity of lean, agile and leagile supply chain constructs in Indian manufacturing industry

Abstract: Supply chain management (SCM) strategy is framed on the basis of competitive strategy (CS) of the firm. Three supply chain strategies (SCS) are evident in SCM literature: cost efficiency, time responsiveness and hybrid of the two. For each of these strategies, three types of supply chains are prescribed: lean, agile and leagile, respectively. Thus, for a firm to achieve strategic alignment between CS and SCS, it is a matter of utter importance to focus on relevant constructs. However, there is a deficiency of standard constructs for these types of supply chains in the SCM literature. Thus, this article addresses the issue of lack of standard constructs in frameworks of lean, agile and leagile supply chain. This objective is achieved by evaluating reliability and validity of lean, agile and leagile supply chain constructs in Indian manufacturing industry. Principle component analysis is performed on these constructs to find out the pillars of each type of supply chain followed by evaluating reliability and...

A critical review of empirical research methodology in supply chain management

Abstract: Purpose – The purpose of this paper is to review the extant literature on empirical research in supply chain management (SCM). It provides a comprehensive assessment of research methodology of 619 empirical research articles on SCM published between 1994 and 2009. In total, 21 journals were short listed out of 115 journals for the purpose.Design/methodology/approach – The paper reviewed a set of 619 empirical research articles in SCM research with respect to empirical research methodology and its related aspects, using the empirical research approach given by Flynn et al. The paper demonstrates the present status of empirical research in SCM.Findings – It is concluded from the analysis of the results that empirical research in SCM is increasing at a faster rate than ever, with theory building more in focus than verification. On the other hand, SCM researchers seems to have left several aspects of empirical research unexplored, such as action research, significance of triangulation of data and longitudinal...

Quantum coherence and sensitivity of avian magnetoreception.

Abstract: Migratory birds and other species have the ability to navigate by sensing the geomagnetic field. Recent experiments indicate that the essential process in the navigation takes place in the bird’s eye and uses chemical reaction involving molecular ions with unpaired electron spins (radical pair). Sensing is achieved via geomagnetic-dependent dynamics of the spins of the unpaired electrons. Here we utilize the results of two behavioral experiments conducted on European robins to argue that the average lifetime of the radical pair is of the order of a microsecond and therefore agrees with experimental estimations of this parameter for cryptochrome—a pigment believed to form the radical pairs. We also find a reasonable parameter regime where the sensitivity of the avian compass is enhanced by environmental noise, showing that long coherence time is not required for navigation and may even spoil it.