Scholarly

Aqueous Extract of Flacourtia indica Prevents Carbon Tetrachloride Induced Hepatotoxicity in Rat

Year: 2010 Volume: 4 Issue: 1 1 - 5 Pages

Abstract: Carbon tetrachloride (CCl4) is a well-known hepatotoxin and exposure to this chemical is known to induce oxidative stress and causes liver injury by the formation of free radicals. Flacourtia indica commonly known as 'Baichi' has been reported as an effective remedy for the treatment of a variety of diseases. The objective of this study was to investigate the hepatoprotective activity of aqueous extract of leaves of Flacourtia indica against CCl4 induced hepatotoxicity. Animals were pretreated with the aqueous extract of Flacourtia indica (250 & 500 mg/kg body weight) for one week and then challenged with CCl4 (1.5 ml/kg bw) in olive oil (1:1, v/v) on 7th day. Serum marker enzymes (ALP, AST, ALT, Total Protein & Total Bilirubin) and TBARS level (Marker for oxidative stress) were estimated in all the study groups. Alteration in the levels of biochemical markers of hepatic damage like AST, ALT, ALP, Total Protein, Total Bilirubin and lipid peroxides (TBARS) were tested in both CCl4 treated and extract treated groups. CCl4 has enhanced the AST, ALT, ALP and the Lipid peroxides (TBARS) in liver. Treatment of aqueous extract of Flacourtia indica leaves (250 & 500 mg/kg) exhibited a significant protective effect by altering the serum levels of AST, ALT, ALP, Total Protein, Total Bilirubin and liver TBARS. These biochemical observations were supported by histopathological study of liver sections. From this preliminary study it has been concluded that the aqueous extract of the leaves of Flacourtia indica protects liver against oxidative damages and could be used as an effective protector against CCl4 induced hepatic damage. Our findings suggested that Flacourtia indica possessed good hepatoprotective activity

An ensemble of Weighted Support Vector Machines for Ordinal Regression

Year: 2007 Volume: 1 Issue: 12 570 - 574 Pages

Abstract: Instead of traditional (nominal) classification we investigate the subject of ordinal classification or ranking. An enhanced method based on an ensemble of Support Vector Machines (SVM-s) is proposed. Each binary classifier is trained with specific weights for each object in the training data set. Experiments on benchmark datasets and synthetic data indicate that the performance of our approach is comparable to state of the art kernel methods for ordinal regression. The ensemble method, which is straightforward to implement, provides a very good sensitivity-specificity trade-off for the highest and lowest rank.

Removal of Arsenic (III) from Contaminated Waterby Synthetic Nano Size Zerovalent Iron

Year: 2010 Volume: 4 Issue: 2 61 - 64 Pages

Abstract: The present work was conducted for Arsenic (III) removal, which one of the most poisonous groundwater pollutants, by synthetic nano size zerovalent iron (nZVI). Batch experiments were performed to investigate the influence of As (III), nZVI concentration, pH of solution and contact time on the efficiency of As (III) removal. nZVI was synthesized by reduction of ferric chloride by sodium borohydrid. SEM and XRD were used to determine particle size and characterization of produced nanoparticles. Up to 99.9% removal efficiency for arsenic (III) was obtained by nZVI dosage of 1 g/L at time equal to 10 min. and pH=7. It could be concluded that the removal efficiency were enhanced with increasing of ZVI dosage and reaction time, but decreased with increasing of arsenic concentration and pH for nano sized ZVI. nZVI presented an outstanding ability to remove As (III) due to not only a high surface area and low particle size but also to high inherent activity.

Detecting Subsurface Circular Objects from Low Contrast Noisy Images: Applications in Microscope Image Enhancement

Year: 2012 Volume: 6 Issue: 7 860 - 866 Pages

Abstract: Particle detection in very noisy and low contrast images is an active field of research in image processing. In this article, a method is proposed for the efficient detection and sizing of subsurface spherical particles, which is used for the processing of softly fused Au nanoparticles. Transmission Electron Microscopy is used for imaging the nanoparticles, and the proposed algorithm has been tested with the two-dimensional projected TEM images obtained. Results are compared with the data obtained by transmission optical spectroscopy, as well as with conventional circular object detection algorithms.

Towards CO2 Adsorption Enhancement via Polyethyleneimine Impregnation

Year: 2012 Volume: 6 Issue: 4 256 - 260 Pages

Abstract: To reduce the carbon dioxide emission into the atmosphere, adsorption is believed to be one of the most attractive methods for post-combustion treatment of flue gas. In this work, activated carbon (AC) was modified by polyethylenimine (PEI) via impregnation in order to enhance CO2 adsorption capacity. The adsorbents were produced at 0.04, 0.16, 0.22, 0.25, and 0.28 wt% PEI/AC. The adsorption was carried out at a temperature range from 30 °C to 75 °C and five different gas pressures up to 1 atm. TG-DTA, FT-IR, UV-visible spectrometer, and BET were used to characterize the adsorbents. Effects of PEI loading on the AC for the CO2 adsorption were investigated. Effectiveness of the adsorbents on the CO2 adsorption including CO2 adsorption capacity and adsorption temperature was also investigated. Adsorption capacities of CO2 were enhanced with the increase in the amount of PEI from 0.04 to 0.22 wt% PEI before the capacities decreased onwards from0.25 wt% PEI at 30 °C. The 0.22 wt% PEI/AC showed higher adsorption capacity than the AC for adsorption at 50 °C to 75 °C.

Simulation of Enhanced Biomass Gasification for Hydrogen Production using iCON

Year: 2010 Volume: 4 Issue: 2 154 - 160 Pages

Abstract: Due to the environmental and price issues of current energy crisis, scientists and technologists around the globe are intensively searching for new environmentally less-impact form of clean energy that will reduce the high dependency on fossil fuel. Particularly hydrogen can be produced from biomass via thermochemical processes including pyrolysis and gasification due to the economic advantage and can be further enhanced through in-situ carbon dioxide removal using calcium oxide. This work focuses on the synthesis and development of the flowsheet for the enhanced biomass gasification process in PETRONAS-s iCON process simulation software. This hydrogen prediction model is conducted at operating temperature between 600 to 1000oC at atmospheric pressure. Effects of temperature, steam-to-biomass ratio and adsorbent-to-biomass ratio were studied and 0.85 mol fraction of hydrogen is predicted in the product gas. Comparisons of the results are also made with experimental data from literature. The preliminary economic potential of developed system is RM 12.57 x 106 which equivalent to USD 3.77 x 106 annually shows economic viability of this process.

Network State Classification based on the Statistical properties of RTT for an Adaptive Multi-State Proactive Transport Protocol for Satellite based Networks

Year: 2009 Volume: 3 Issue: 4 886 - 902 Pages

Abstract: This paper attempts to establish the fact that Multi State Network Classification is essential for performance enhancement of Transport protocols over Satellite based Networks. A model to classify Multi State network condition taking into consideration both congestion and channel error is evolved. In order to arrive at such a model an analysis of the impact of congestion and channel error on RTT values has been carried out using ns2. The analysis results are also reported in the paper. The inference drawn from this analysis is used to develop a novel statistical RTT based model for multi state network classification. An Adaptive Multi State Proactive Transport Protocol consisting of Proactive Slow Start, State based Error Recovery, Timeout Action and Proactive Reduction is proposed which uses the multi state network state classification model. This paper also confirms through detail simulation and analysis that a prior knowledge about the overall characteristics of the network helps in enhancing the performance of the protocol over satellite channel which is significantly affected due to channel noise and congestion. The necessary augmentation of ns2 simulator is done for simulating the multi state network classification logic. This simulation has been used in detail evaluation of the protocol under varied levels of congestion and channel noise. The performance enhancement of this protocol with reference to established protocols namely TCP SACK and Vegas has been discussed. The results as discussed in this paper clearly reveal that the proposed protocol always outperforms its peers and show a significant improvement in very high error conditions as envisaged in the design of the protocol.

Keywords:
GEO
ns2
Proactive TCP
SACK
Vegas

An Investigation of the Effect of the Different Mix Constituents on Concrete Electric Resistivity

Year: 2009 Volume: 3 Issue: 10 355 - 358 Pages

Abstract: Steel corrosion in concrete is considered as a main engineering problems for many countries and lots of expenses has been paid for their repair and maintenance annually. This problem may occur in all engineering structures whether in coastal and offshore or other areas. Hence, concrete structures should be able to withstand corrosion factors existing in water or soil. Reinforcing steel corrosion enhancement can be measured by use of concrete electrical resistance; and maintaining high electric resistivity in concrete is necessary for steel corrosion prevention. Lots of studies devoted to different aspects of the subjects worldwide. In this paper, an evaluation of the effects of W/C ratio, cementitious materials, and percent increase in silica fume were investigated on electric resistivity of high strength concrete. To do that, sixteen mix design with one aggregate grading was planned. Five of them had varying amount of W/C ratio and other eleven mixes was prepared with constant W/C ratio but different amount of cementitious materials. Silica fume and super plasticizer were used with different proportions in all specimens. Specimens were tested after moist curing for 28 days. A total of 80 cube specimens (50 mm) were tested for concrete electrical resistance. Results show that concrete electric resistivity can be increased with increasing amount of cementitious materials and silica fume.

Speech Enhancement by Marginal Statistical Characterization in the Log Gabor Wavelet Domain

Year: 2008 Volume: 2 Issue: 11 2456 - 2462 Pages

Abstract: This work presents a fusion of Log Gabor Wavelet (LGW) and Maximum a Posteriori (MAP) estimator as a speech enhancement tool for acoustical background noise reduction. The probability density function (pdf) of the speech spectral amplitude is approximated by a Generalized Laplacian Distribution (GLD). Compared to earlier estimators the proposed method estimates the underlying statistical model more accurately by appropriately choosing the model parameters of GLD. Experimental results show that the proposed estimator yields a higher improvement in Segmental Signal-to-Noise Ratio (S-SNR) and lower Log-Spectral Distortion (LSD) in two different noisy environments compared to other estimators.

Bayesian Belief Networks for Test Driven Development

Year: 2007 Volume: 1 Issue: 11 3375 - 3380 Pages

Abstract: Testing accounts for the major percentage of technical contribution in the software development process. Typically, it consumes more than 50 percent of the total cost of developing a piece of software. The selection of software tests is a very important activity within this process to ensure the software reliability requirements are met. Generally tests are run to achieve maximum coverage of the software code and very little attention is given to the achieved reliability of the software. Using an existing methodology, this paper describes how to use Bayesian Belief Networks (BBNs) to select unit tests based on their contribution to the reliability of the module under consideration. In particular the work examines how the approach can enhance test-first development by assessing the quality of test suites resulting from this development methodology and providing insight into additional tests that can significantly reduce the achieved reliability. In this way the method can produce an optimal selection of inputs and the order in which the tests are executed to maximize the software reliability. To illustrate this approach, a belief network is constructed for a modern software system incorporating the expert opinion, expressed through probabilities of the relative quality of the elements of the software, and the potential effectiveness of the software tests. The steps involved in constructing the Bayesian Network are explained as is a method to allow for the test suite resulting from test-driven development.

Throughput Enhancement in AUDTWMN Using Throwboxes – An Overview

Year: 2010 Volume: 4 Issue: 10 1474 - 1482 Pages

Abstract: Delay and Disruption Tolerant Networking is part of the Inter Planetary Internet with primary application being Deep Space Networks. Its Terrestrial form has interesting research applications such as Alagappa University Delay Tolerant Water Monitoring Network which doubles as test beds for improvising its routing scheme. DTNs depend on node mobility to deliver packets using a store-carry-and forward paradigm. Throwboxes are small and inexpensive stationary devices equipped with wireless interfaces and storage. We propose the use of Throwboxes to enhance the contact opportunities of the nodes and hence improve the Throughput. The enhancement is evaluated using Alunivdtnsim, a desktop simulator in C language and the results are graphically presented.

A New Strategy for Minimizing Precipitations during ASP Flooding in Carbonate Reservoirs

Year: 2012 Volume: 6 Issue: 12 1123 - 1125 Pages

Abstract: A large quantity of world-s oil reserves exists in carbonate reservoirs. Carbonate reservoirs are very sensitive to chemical enhanced oil recovery process because of containing large amount of calcite, dolomite and calcium sulfate minerals. These minerals cause major obstacles during alkali-surfactant-polymer (ASP) flooding. Alkali reacts with these minerals and form undesired precipitations which plug effective porous openings, reduce permeability and cause scale occurrence at the wellbore. In this paper, a new chemical combination consists of acrylic acid and alkali was used to minimize precipitation problem during ASP flooding. A series of fluid-fluid compatibility tests were performed using acrylic acid and different concentrations of alkaline. Two types of alkalis namely; sodium carbonate and sodium metaborate were screened. As a result, the combination of acrylic acid and sodium carbonate was not effective in preventing calcium and magnesium precipitations. However, acrylic acid and sodium metaborate showed promising results for keeping all solutions without any precipitations. The ratio of acrylic acid to sodium metaborate of 0.7:1.0 was found to be optimum for achieving a compatible solution for 30 days at 80oC.

One-Dimensional Numerical Investigation of a Cylindrical Micro-Combustor Applying Electrohydrodynamics Effect

Year: 2012 Volume: 6 Issue: 7 1116 - 1123 Pages

Abstract: In this paper, a one-dimensional numerical approach is used to study the effect of applying electrohydrodynamics on the temperature and species mass fraction profiles along the microcombustor. Premixed mixture is H2-Air with a multi-step chemistry (9 species and 19 reactions). In the micro-scale combustion because of the increasing ratio of area-to-volume, thermal and radical quenching mechanisms are important. Also, there is a significant heat loss from the combustor walls. By inserting a number of electrodes into micro-combustor and applying high voltage to them corona discharge occurs. This leads in moving of induced ions toward natural molecules and colliding with them. So this phenomenon causes the movement of the molecules and reattaches the flow to the walls. It increases the velocity near the walls that reduces the wall boundary layer. Consequently, applying electrohydrodynamics mechanism can enhance the temperature profile in the microcombustor. Ultimately, it prevents the flame quenching in microcombustor.

Brain MRI Segmentation and Lesions Detection by EM Algorithm

Year: 2008 Volume: 2 Issue: 12 379 - 382 Pages

Abstract: In Multiple Sclerosis, pathological changes in the brain results in deviations in signal intensity on Magnetic Resonance Images (MRI). Quantitative analysis of these changes and their correlation with clinical finding provides important information for diagnosis. This constitutes the objective of our work. A new approach is developed. After the enhancement of images contrast and the brain extraction by mathematical morphology algorithm, we proceed to the brain segmentation. Our approach is based on building statistical model from data itself, for normal brain MRI and including clustering tissue type. Then we detect signal abnormalities (MS lesions) as a rejection class containing voxels that are not explained by the built model. We validate the method on MR images of Multiple Sclerosis patients by comparing its results with those of human expert segmentation.

Semantic Mobility Channel (SMC): Ubiquitous and Mobile Computing Meets the Semantic Web

Year: 2007 Volume: 1 Issue: 11 1574 - 1579 Pages

Abstract: With the advent of emerging personal computing paradigms such as ubiquitous and mobile computing, Web contents are becoming accessible from a wide range of mobile devices. Since these devices do not have the same rendering capabilities, Web contents need to be adapted for transparent access from a variety of client agents. Such content adaptation is exploited for either an individual element or a set of consecutive elements in a Web document and results in better rendering and faster delivery to the client device. Nevertheless, Web content adaptation sets new challenges for semantic markup. This paper presents an advanced components platform, called SMC, enabling the development of mobility applications and services according to a channel model based on the principles of Services Oriented Architecture (SOA). It then goes on to describe the potential for integration with the Semantic Web through a novel framework of external semantic annotation that prescribes a scheme for representing semantic markup files and a way of associating Web documents with these external annotations. The role of semantic annotation in this framework is to describe the contents of individual documents themselves, assuring the preservation of the semantics during the process of adapting content rendering. Semantic Web content adaptation is a way of adding value to Web contents and facilitates repurposing of Web contents (enhanced browsing, Web Services location and access, etc).

The Application of Hadamard Matrixes in the SNR Enhancement of Optical Time-Domain Reflectometry(OTDR)

Year: 2008 Volume: 2 Issue: 6 1052 - 1054 Pages

Authors:
Mingyu Zhong
Yi Xie

Abstract: Results in one field necessarily give insight into the others, and all have much potential for scientific and technological application. The Hadamard-transform technique once been applied to the spectrometry also has its use in the SNR Enhancement of OTDR. In this report, a new set of code (Simplex-codes) is discussed and where the addition gain of SNR come from is implied.

Keywords:
Hadamard-transform
matrixes
averaging
opticaltime-domain reflectometry (OTDR).

Visualising Energy Efficiency Landscape

Year: 2009 Volume: 3 Issue: 5 286 - 289 Pages

Abstract: This paper discusses the landscape design that could increase energy efficiency in a house. By planting trees in a house compound, the tree shades prevent direct sunlight from heating up the building, and it enables cooling off the surrounding air. The requirement for air-conditioning could be minimized and the air quality could be improved. During the life time of a tree, the saving cost from the mentioned benefits could be up to US $ 200 for each tree. The project intends to visually describe the landscape design in a house compound that could enhance energy efficiency and consequently lead to energy saving. The house compound model was developed in three dimensions by using AutoCAD 2005, the animation was programmed by using LightWave 3D softwares i.e. Modeler and Layout to display the tree shadings in the wall. The visualization was executed on a VRML Pad platform and implemented on a web environment.

Quantum Computation using Two Component Bose-Einstein Condensates

Year: 2012 Volume: 6 Issue: 3 199 - 204 Pages

Authors:
Tim Byrnes

Abstract: Quantum computation using qubits made of two component Bose-Einstein condensates (BECs) is analyzed. We construct a general framework for quantum algorithms to be executed using the collective states of the BECs. The use of BECs allows for an increase of energy scales via bosonic enhancement, resulting in two qubit gate operations that can be performed at a time reduced by a factor of N, where N is the number of bosons per qubit. We illustrate the scheme by an application to Deutsch-s and Grover-s algorithms, and discuss possible experimental implementations. Decoherence effects are analyzed under both general conditions and for the experimental implementation proposed.

Mathematical Modeling of Asphaltene Precipitation: A Review

Year: 2013 Volume: 7 Issue: 10 722 - 725 Pages

Abstract: In the Enhanced Oil Recovery (EOR) method, use of Carbon dioxide flooding whereby CO2 is injected into an oil reservoir to increase output when extracting oil resulted significant recovery worldwide. The carbon dioxide function as a pressurizing agent when mixed into the underground crude oil will reduce its viscosity and will enable a rapid oil flow. Despite the CO2’s advantage in the oil recovery, it may result to asphaltene precipitation a problem that will cause the reduction of oil produced from oil wells. In severe cases, asphaltene precipitation can cause costly blockages in oil pipes and machinery. This paper presents reviews of several studies done on mathematical modeling of asphaltene precipitation. The synthesized result from several researches done on this topic can be used as guide in order to better understand asphaltene precipitation. Likewise, this can be used as initial reference for students, and new researchers doing study on asphaltene precipitation.

Use of NMMO Pretreatment for Biogas Production from Oil Palm Empty Fruit Bunch

Year: 2012 Volume: 6 Issue: 5 398 - 401 Pages

Abstract: Pretreatment of oil palm empty fruit bunch (OPEFB) with N-Methylmorpholine-N-oxide (NMMO) to enhance biogas production was investigated. The pretreatments were performed at 90 and 120ºC for 1, 3, and 5 h using three different concentrations of NMMO of 73%, 79%, and 85%. The pretreated OPEFB was subsequently anaerobically digested to produce biogas. After pretreatment, there were no significant changes of the main composition of OPEFB and the maximum total solid recovery was 92%. The amorphous phase was increased up to 78% at pretreatment condition using 85% NMMO solution for 3 h at 120oC. In general, higher concentration of NMMO and higher temperature resulted in increased amorphous form and higher biogas production. The best results of biogas production reached enhancement of methane yield of 148% compared to the untreated OPEFB and increased in digestion of 94% compared to starch as reference.

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