Showing papers by "Heritage Institute of Technology published in 2016"

Mixed consortia in bioprocesses: role of microbial interactions

Abstract: The utilization of mixed consortia or mixed culture has become a current research trend of applied microbiology, bioprocess engineering and biotechnology. The constituent microorganisms of such mixed cultures can jointly perform complex processes efficiently, yielding the desired product at an augmented rate, in comparison to monocultures. It is understandable that the interactions between the microbial partners in these mixed cultures are expected to have a significant impact on the combined performance of the microorganisms and the bioprocess as a whole. Prevalence of positive interactions (commensalism or mutualism) among microbial members of a mixed culture or consortia can significantly enhance the product outcome of the bioprocess, ensuring their industrial application and long-term stability. On the contrary, negative interaction (parasitism, predation or ammensalism) leads to elimination of microbial members from the consortia causing the destruction of community structure as well as disruption of cumulative performance. Therefore, a priori knowledge on the type of interaction between the microorganisms is also essential for the optimization of the performance of the designed consortia. This could only be achieved through the study of inter-microbial interaction prevailing in a mixed culture. In the present article, different bioprocess applications of mixed cultures, currently in practice along with types of positive microbial interactions involved, have been reviewed. Complexity of mixed cultures from the perspective of multiple types of intra-culture relationships has been explained in detail. Overall, the necessity for more in-depth research studies on "microbial interaction" in mixed culture bioprocesses has been stressed in the article.

A review on the production of fermentable sugars from lignocellulosic biomass through conventional and enzymatic route—a comparison

Abstract: The scarcity of fossil fuels has urged the economically developed countries to find the resources for an alternative energy sources. In apprehension to this, biofuels, like bioethanol and biobutanol, produced from lignocellulosic biomass were considered as potential alternative. There are several methods for the pretreatment of biomass before it is being used as a feedstock for the production of fermentable sugars. However, one of the crucial concerns here is to enumerate an economic pretreatment scheme that can be implemented in large scale for the production of mostly exposed cellulosic part from biomass. This will ensure an effective hydrolysis of cellulose for the production of fermentable sugars and the production of biobutanol from these derived sugars. Moreover, the keynote understanding of an effective fermentation is the production of less inhibitory compounds like furfural, hydroxymethyl furfural during the hydrolysis of cellulose. Enzymatic hydrolysis of cellulose was reported as the mo...

Supplier selection criteria and methods: past, present and future

Abstract: Sole purpose of supplier selection is not limited to get supply at low cost and at right time. Supplier selection is a strategic decision to fulfil company's goal for long period of time at low risk. To accomplish this objective companies are moving from reactive buying to proactive buying to give more priority to co-creation of wealth with supplier/s. Considering this issue an attempt has been made in this paper to give systematic review of supplier selection and evaluation process from 2005 to 2012 to answer three main questions: 1) Which method is more appropriate for supplier selection? 2) Which evaluating criteria were most cited? 3) Is present trend of research is adequate enough to support proactive buying? In this regard, 78 papers are classified into ten categories to identify factors affecting supplier selection and evaluation process. Statistical analysis has been conducted with software 'R' to have better insight on the trend of research. Recommendations and future work is also included to verify inadequacy of existing methods, if any, to support proactive buying process.

E-Waste Management – A Potential Route to Green Computing

Abstract: Green computing is a recent trend and an evolving field aiming towards a sustainable future. Different approaches have been established as possible directions towards green computing. Virtualization, Cloud computing, Energy minimization, reduction in use of hazardous substances in electronic items etc are a few approaches. Though major focus has shifted towards energy minimization, other approaches have churned themselves out as new subjects – cloud computing. Green computing encompasses a wide range of things. One of them is e-waste management. End of life electronic equipments known as e-waste is a threat to the whole world. Globally 41.8 million metric tonnes of e-waste was generated in 2014. These electronic items are the hardware part of the computer. The proper management of e-waste hence leaves a good potential to implement green computing. An overwhelming amount of research articles focusing on green computing are present and major focus is on energy minimization, efficient algorithms and cloud computing. Literature on green computing focusing on e-waste management is scant. The research questions aroused are as follows. Is it actually possible to implement green computing using e-waste management? What are the issues pertaining to it? How can this be achieved? How sustainable it this approach? The study tries to answer these questions. The main objective of this study is to establish e-waste management as a parameter for green computing. The study also intends to check the sustainability potential of this approach. The paper will help the stakeholders, practitioners, researchers and decision makers for choosing a benchmark approach and will pave directions for future research.

Best-effort delivery of emergency messages in post-disaster scenario with content-based filtering and Priority-enhanced PRoPHET over DTN

Abstract: Despite concerted efforts for relaying crucial situational information, disaster relief volunteers experience significant communication challenges owing to failures of critical infrastructure and longstanding power outages in disaster affected areas. Researchers have proposed the use of smartphones, working in delay tolerant (DTN) mode, for setting up a peer-to-peer network enabling post disaster communication. However, due to opportunistic contacts, intermittent connectivity and constrained resources (mainly battery) of mobile devices, not all messages get forwarded in such a network. As a result, several crucial messages, waiting in the buffer may get dropped and unimportant, extraneous (sentimental comments of victims, etc.) messages may get transmitted at the cost of expensive network resources. Therefore, filtering out such irrelevant messages (containing unrelated information and emotional expressions) and prioritizing relevant messages according to its importance becomes crucial so that messages which are critical for decision making receive the highest priority and get disseminated in the network at the minimum possible time. In this paper, our objective is to ensure best-effort delivery of emergency messages using a two-step approach, (i) segregation of high priority messages through natural language processing based filtering and (ii) dissemination of filtered messages over DTN using a Priority-enhanced PRoPHET routing protocol which is developed by adapting the popular PRoPHET routing protocol. The protocol successfully achieves on-the-fly message prioritization and ensures best effort delivery of such prioritized messages to their appropriate destinations. The proposed protocol is evaluated using the ONE simulator. Simulation results suggest that our protocol outperforms other well known DTN routing protocols like PRoPHET, Spray-And-Wait, MaxProp and Epidemic in terms of delivery ratio of prioritized messages and overhead ratio.

Electronic Components (EC) Reuse and Recycling – A New Approach towards WEEE Management

Abstract: Waste Electrical and Electronic Equipments (WEEE) is the fastest growing waste stream in the world. In 2014, a total amount of 41.8 metric kilotonnes of WEEE was generated globally. There are two main parts of a WEEE – a) The Printed Circuit Board (PCB) and b) The Casing i.e. the polymer and/or metal portion that covers the PCB. PCBs contain a lot of components like resistors, transistors, microcontrollers, integrated circuits etc. Once a Electrical and Electronic Equipment (EEE) becomes obsolete; Electronic Components (EC) in the PCB remains unaltered. These ECs can be reused based on their status. In most of the cases, the PCBs end up in the informal sector that employs open burning, acid leaching etc to recover valuable metals from it and the residues end up in landfill which is a malpractice. In this work, two case has been considered – a) Small WEEE (mouse, speakers, headphones, mobile, radio, wires etc) and b) Large WEEE (Laptop, desktops, TV, printer etc). PCBs from these two types of WEEE have been examined. A solution is proposed that will help to enhance the reuse and recycling of the ECs obtained from the PCBs. The proper technique for de-soldering of ECs from the PCB and further testing methods has been discussed. Proper recycling routes of the unusable ECs have also been suggested. Finally, a novel framework has been proposed that will enhance the EC reusability and recycling. The findings will help the stakeholders in decision making, the researchers in considering future research direction and overall a sustainable future for both semiconductor and electronics industry.

Photoplethysmogram signal based biometric recognition using linear discriminant classifier

Abstract: A preliminary study on photoplethysmogram (PPG) based biometry system is presented here. PPG is a physiological signal related to cardiac output and blood flow saturation in body. Recently it is reported that being an automatic physiological phenomenon PPG and other biosignals can be used as biometric parameters for human authentication. In this work, 12 number of features are extracted from filtered PPG and its derivatives and Linear Discriminant Analysis (LDA) is used for classification over the statistical parameters extracted from the feature set. 100% accuracy is achieved for 15 number of data captured using Biopac MP 45.

Tea Quality Prediction by Autoregressive Modeling of Electronic Tongue Signals

Abstract: In this paper, a novel method to model the responses of electronic tongue (ET) sensors using autoregressive (AR) and AR moving average techniques is presented. The transient response of each electrode present in the sensor array of an ET is characterized with tea samples of different qualities. Models coefficients are used as the characteristics features of the ET response corresponding to the tea samples. Three different classifiers, namely, artificial neural network, vector valued regularized kernel function approximation, and one-versus-one support vector machine, are employed to evaluate the performance of these features to discriminate the quality of black tea. Experimental results on three types of voltammetric measurement data show that the proposed method may be very useful for prediction of tea quality. The present model-based classification method is very straightforward and provides better or similar performance compared with some other methods proposed in the literature for ET signal classification.

Geometric nonlinear free vibration of axially functionally graded non-uniform beams supported on elastic foundation

Abstract: Abstract In the present study non-linear free vibration analysis is performed on a tapered Axially Functionally Graded (AFG) beam resting on an elastic foundation with different boundary conditions. Firstly the static problem is carried out through an iterative scheme using a relaxation parameter and later on the subsequent dynamic problem is solved as a standard eigen value problem. Minimum potential energy principle is used for the formulation of the static problem whereas for the dynamic problem Hamilton’s principle is utilized. The free vibrational frequencies are tabulated for different taper profile, taper parameter and foundation stiffness. The dynamic behaviour of the system is presented in the form of backbone curves in dimensionless frequency-amplitude plane.

Experimental studies and two-dimensional modelling of a packed bed bioreactor used for production of galacto-oligosaccharides (GOS) from milk whey.

Abstract: In the present study, extensive experimental investigations and detailed theoretical analysis of a two-dimensional packed bed bioreactor, employed for the production of galacto-oligosaccharides (GOS) from milk whey were performed. Model equations, in one- and two-dimensions, capable of predicting the substrate concentration distribution in the bioreactor were developed by coupling mass balance equation with appropriate velocity distribution equation and solved numerically. Validation of the proposed model equations was done by a set of experimental data obtained from the bioreactor. The effects of reactor to catalyst particle diameter ratio (d t/d p), feed flowrate (10(-6)-10(-9) m(3) s(-1)), and initial lactose concentration (50-200 kg m(-3)) on substrate concentration distribution were investigated in detail. While, the distribution of substrate concentration in axial direction was independent of d t/d p, it was observed that for d t/d p <40, significant radial concentration distribution existed. It was further observed that the substrate conversion and product yield obtained experimentally showed an excellent agreement (97 ± 2 %) with the results predicted by the two-dimensional model equation, whereas, the results predicted by the one-dimensional model equation did not lie within the desired confidence level (<90 %). The results were confirmed by both curve fitting and statistical analysis. The prediction of substrate concentration distribution in axial and radial directions using the developed two-dimensional model equation is necessary for computing the bioreactor volume to achieve the desired GOS yield.

Evaluation of performance of Planococcus sp. TRC1 an indigenous bacterial isolate monoculture as bioremediator for tannery effluent

Abstract: An indigenous bacterial isolate Planococcus sp. TRC1 was found to tolerate Cr(VI) solution up to 500 mg/L concentration when grown in mineral salt media. Gene sequencing of the isolated strain using 16S rDNA technique and phylogenetic analysis confirmed that the species was 96% close to Planococcus maritimus (KP8). Studies on cell dynamics in batch bioreactor showed the maximum specific cell growth rate (μmax) to be 0.276 h−1. Removal of Cr(VI) was observed to be dependent on initial chromium concentration and the maximum removal of Cr(VI) (75 ± 3%) was obtained at 25 mg/L Cr(VI) solution for an incubation period of 72 h. Above this value, the removal of Cr(VI) was declined. Scanning electron microscope and Fourier transform infrared spectroscopic studies indicated that the Cr(VI) removal took place by the adsorption process on the cell outer membrane. It is observed that the adsorption process follows the Freundlich adsorption isotherm (R2 = 0.987). Planococcus sp. TRC1 reduced 80 ± 5% chemical o...

A novel gene ranking method using Wilcoxon rank sum test and genetic algorithm

Abstract: Over the last few decades, a large amount of research work has been carried on genomic data. The cancer disease make cells in specific tissues in the body undergo uncontrolled division which results in the malignant growth or tumour. Today, DNA microarray technologies allow us to simultaneously monitor the expression pattern of thousands of genes. Microarray gene expression data are characterised by a very high dimensionality genes, and a relatively small number of samples observations. If one wants to identify all those genes from these thousands of gene expressions which are responsible for the disease like cancer, then it is useful to rank the genes. In this paper, we have proposed a novel gene ranking method based on Wilcoxon Rank Sum Test and genetic algorithm. WRST has been used for reducing dimensionality and genetic algorithm for finding out those differentially expressed genes. The final subset of genes has been cross-validated using k fold LOOCV k varied for different dataset method and thereafter used for classification of data using SVM with linear kernel. At first the proposed method has been applied on two relatively new benchmark datasets, like GDS4382 colorectal cancer dataset and GDS4794 small cell lung cancer dataset and the results show that the proposed method can reach up to 100% classification accuracy with very few dominant genes, which indirectly validates the biological and statistical significance of the proposed method. After that it is also applied on five real-life datasets and the results are compared with one of the recent state of the art approach on the basis of % of Accuracy, Sensitivity, and Specificity etc.

A human mobility based knowledge sharing approach for post disaster need assessment using DTN

Abstract: In a post disaster scenario, assessment of resource needs is indeed challenging because needs are constantly changing and supplies trickle in at an uncertain rate. Moreover, information about resource needs of far-flung areas get rarely permeated owing to the disruption of cellular and other communication infrastructure, leading to a huge gap in perception about the actual needs in those areas. Therefore, a dynamic need assessment mechanism is essential to stay abreast of the actual situation. Movements of volunteers and relief workers are governed by two dominant characteristics of human mobility - spatial locality and spatial regularity. In this paper, we make use of such mobility characteristics to propose a knowledge sharing based approach for dynamic assessment of post disaster resource needs using a smart-phone based delay tolerant network (DTN). The proposed technique caters to the objective of bridging the gap in perception about actual resource needs.

Towards a Collaborative Disaster Management Service Framework using Mobile and Web Applications: A Survey and Future Scope

Abstract: Getting the right information at the right time and place is the key for efficient disaster management. Various mobile and web applications are now being used for collecting situational information in digital form, assessing damage, coordinating relief operations and offering different location based services to the affected communities during disaster management. This article provides a thorough investigation on popular web-based and mobile applications currently being used in different countries. Subsequently, the taxonomy of essential services needed for systematic and coordinated disaster management is formulated based on literature review and the authors' interaction with different stakeholders. An outline of a collaborative disaster management service framework is then proposed with the facility of interaction for the stakeholders through their mobile phones to avail the services in different phases of a disaster. A basic version of this framework is implemented to evaluate its effectiveness as a provider of significant actionable information to offer responsive services

A multi-item periodic review probabilistic fuzzy inventory model with possibility and necessity constraints

Abstract: This paper investigates a multi-item periodic review probabilistic inventory model in fuzzy environment. Here, we have considered a single source of the inventory model with zero lead time and varying order cost under two limitations, such as holding cost and safety stock. By employing the fuzzy expectation and possibility/necessity measure, the fuzzy model is transformed into an equivalent deterministic non-linear programming problem. Finally, the model is illustrated with the help of numerical example and few sensitivity analyses are also presented for different parameter to show the validity of the proposed model.