Showing papers by "International Islamic University, Chittagong published in 2011"

The Adoption of Mobile Commerce Service among Employed Mobile Phone Users in Bangladesh: Self-efficacy as a Moderator

Abstract: Mobile commerce or better known as M-commerce is a fairly new phenomenon in the wake of the second technology wave from the famous E-commerce (electronic commerce) in the 21st century As the Internet started to proliferate in many parts of the world, the mobile phone penetration in terms of voice communication started to grow rapidly This simultaneous rapid growth has caused a new phenomenon of convergence of Internet computing and mobile communication where M-commerce has its root M-commerce has the potential to enhance the work-life within the employed mobile phone users in Bangladesh The purpose of this study is to examine whether awareness and knowledge, convenience of Mobile devices and WAP/GPRS enabled handsets, pricing and cost, security and privacy, rich and fast information, and perceived usefulness have any influence on the adoption of M-commerce among employed Mobile phone users in two major cities in Bangladesh – Dhaka and Chittagong A survey method was used to collect data The findings suggest that pricing and cost, rich and fast information, and security and privacy are significant predictors of the adoption of M-commerce Self-efficacy is found to be a moderating factor for the adoption of M-commerce services The findings also suggest that there is no significant gender difference in terms of M-commerce adoption level among mobile users in Bangladesh

Low voltage DC distribution system compared with 230 V AC

Abstract: In this work low voltage DC distribution systems for a home are investigated by evaluating the advantages and disadvantages to 230V systems. The aim of the work is to connect the systems with local generation such as solar cell, micro turbine and energy storages at the end user level. Data obtained from measurements of power consumption for different household appliances such as refrigerator, microwave oven, rice cooker, dish washer etc. have been used to evaluate the systems. The performance of the 230V AC system and the proposed low voltage DC system is analyzed by considering factors such as losses in the wire, internal loss of the device itself, investment cost for new wiring, energy consumption cost

Thrombolytic potential of Ocimum sanctum L., Curcuma longa L., Azadirachta indica L. and Anacardium occidentale L

Abstract: Atherothrombotic diseases such as myocardial or cerebral infarction are serious consequences of the thrombus formed xin blood vessels. Thrombolytic agents are used to dissolve the already formed clots in the blood vessels; however, these drugs have certain limitations which cause serious and sometimes fatal consequences. Herbal preparations have been used since ancient times for the treatment of several diseases. The aim of this study was to investigate whether herbal preparations possess thrombolytic activity or not. An in vitro thrombolytic model was used to check the clot lysis effect of four aqueous herbal extracts viz., O. sanctum, C. longa, A. indica, A. occidentale along with Streptokinase as a positive control and water as a negative control. The percentage (%) clot lysis was statistically significant (p<0.0001) when compared with vehicle control. Using an in vitro thrombolytic model, O. sanctum, C. longa, A. indica & A. occidentale showed moderate clot lysis activity (30.01 ± 6.168%, 32.94 ± 3.663%, 27.47 ± 6.943%, 33.79 ± 2.926% respectively) whereas standard streptokinase showed 86.2 ± 10.7 % clot lysis effect. From our study we found that all the herbs showed reasonable % of clot lysis. These herbal extracts possess thrombolytic properties that could lyse blood clots in vitro; however, in vivo clot dissolving properties and active component(s) of these extracts for clot lysis are yet to be discovered.

Sedative and anxiolytic effects of the methanolic extract of Leea indica (Burm. f.) Merr. leaf.

Abstract: The sedative and anxiolytic potential of Leea indica (Burm. f.) Merr., a Bangladeshi tribal medicinal plant was studied for the first time. The crude methanol extract of L. indica leaves was evaluated for its central nervous system (CNS) depressant effect using rodent behavioral models, such as hole cross, open field and thiopental sodium induced sleeping time tests for its sedative properties and an elevated plus-maze (EPM) test for its anxiolytic potential, respectively. The methanol extract of L. indica at doses of 200 mg/kg, p.o. and 400 mg/kg, p.o., displayed a dose dependent suppression of motor activity, exploratory behavior (in hole cross and open field tests) and prolongation of thiopental induced sleeping time in mice; the highest CNS depressant effect was shown at a dose of 400 mg/kg, p.o. In the EPM test, both dose of methanol extract significantly (p < 0.01) increased exploration to and time spent by the treated mice in EPM open arms in a dose dependent manner. These results provide in vivo evidence that leaves of L. indica in general have significant sedative and anxiolytic effects. However, these results may rationalize the scientific basis for use of this plant in traditional medicine for treatment of anxiety and related disorders.

Design and implementation of MPPT controlled grid connected photovoltaic system

Abstract: This paper proposes an intelligent method for maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and insolation conditions and conversion of this solar energy into stabilized sine wave having low distortion factor (DF), so that the solar energy can be supplied to grid and can operate electrical and electronic devices efficiently. For the reduction of tracking time of maximum power from photovoltaic array and to obtain stabilized sine wave with very fast rise time for voltage stability, fuzzy logic control algorithm is implemented with the embedded microcontroller for improved performance as compared to conventional techniques. The system includes a photovoltaic array; a PWM controlled DC-DC, DC-AC converters, sensor circuits and zero crossing detector (ZCD). The designed MPPT controller regulates the converter output voltage by varying modulation index of the PWM pattern using MPPT algorithm and it maximizes the output power extracted from photovoltaic array. This paper discusses the low cost implementation of MPP algorithm in a 8-bit microcontroller using the tools and techniques to generate optimized real time code in C for ATMega8 microcontroller which will demonstrate how maximum power point tracker might provide elegant and efficient solution for increasing the efficiency of a solar system and connection of the extracted energy to grid which is based on experimental results rather than on mathematical models.

Heat Transfer Enhancement of Copper-water Nanofluids in an Inclined Lid-driven Triangular Enclosure

Abstract: A numerical study is conducted to investigate the transport mechanism of mixed convection in an inclined lid-driven triangular enclosure subject to cooling at the inclined right surface and simultaneous heating at the base surface filled with nanofluids. Fluid mechanics and conjugate heat transfer, described in terms of continuity, linear momentum and energy equations, are predicted by using the Galerkin finite element method. Numerical results are obtained for a wide range of parameters such as the Richardson number, tilt angle, and copper-water nanofluids is used with Prandtl number, P r = 6.2. The streamlines, isotherm plots and the variation of the average Nusselt number at the hot surface as well as average fluid temperature in the enclosure is presented and discussed. It is found that the tilt angle strongly affects the fluid flow and heat transfer in the enclosure at the three convective regimes. Keywords: Copper-water nanofluid; Penalty finite element method; Lid-driven triangular enclosure; Tilt angle; Mixed convection. © 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi:10.3329/jsr.v3i3.7642 J. Sci. Res. 3 (2), 535-548 (2011)

Antibacterial and cytotoxic activity of ethanol extract of mikania cordata (burm.f.) B.L. Robinson leaves.

Abstract: The purpose of the present study to examine the antibacterial and cytotoxic properties of ethanol extract of leaves of Mikania cordata (Burm.f.) B.L. Robinson. To determine antibacterial activities, the extract was tested against four Gram positive and six Gram negative bacteria at three concentrations (500, 800, 1000 μg disc(-1)) through disc diffusion method. The extract showed moderate antibacterial actions and that was increased by increasing the concentration of the sample. The maximum antimicrobial potential was obtained against Shigella flexneri and no sen sitivity was found for Klebsiella sp. Comparatively gram-positive bacteria demonstrated more susceptibility to the extract than gram-negative bacteria. Cytotoxic property of the sample was done using Brine shrimp lethality bioassay where it did not show noticeable toxicity. So, our present study reveals that the leaves extract of M. cordata possess considerable antibacterial properties along with lesser amount of cytotoxicity.

Antibacterial, cytotoxic and antioxidant potential of methanolic extract of phyllanthus acidus L

Abstract: The objective of the present study was to evaluate antimicrobial, cytotoxic and antioxidant potential of methanol extract of fruit part of Phyllanthus acidus. Phytochemical screening showed evidence of glycoside, tannin and resin. Antimicrobial activity was evaluated using disc diffusion method against 13 pathogenic bacteria where in higher concentration the extract showed moderate to good zone of inhibition against B. megaterium and B. subtilis also with S. typhi and S. dysenteriae. In case of brine shrimp cytotoxicity assay, showed good result with LC50 value 4.46 μg/ml where as LC90 value was 70.79 μg/ml. Antioxidant activity was evaluated by using total flavonoid content determination assays, total antioxidant capacity, 1,1-diphenyl-2-picryl-hydrazil (DPPH) free radical assay, reducing power assessment, cupric ion reducing capacity assay (CUPRAC method). The extract showed moderate to good antioxidant activity in a dose dependent manner and found to contain flavonoid compounds. In DPPH radical scavenging assay IC50 value found 2063.42 μg/ml and compared to ascorbic acid with 52 μg/ml. The extract also showed good cupric ion reducing capacity. The results of the present study indicate that the extract possesses moderate to good antioxidant potential.

Modeling of the out-of-plane resistivity of cuprate superconductors

Abstract: The out-of-plane ( c -axis) resistivity, ρ c ( T ), of high- T c cuprates have been modeled in this study. The non-Fermi liquid like temperature dependence of ρ c ( T ) has been described by considering (i) the full impact of the pseudogap (PG) in the electronic density of states (EDOS) and (ii) the presence of a quantum critical point (QCP) beneath the superconducting dome at slightly overdoped region. This simple phenomenological model describes the experimental ρ c ( T ) data over a wide range of hole content (from the underdoped to slightly overdoped regions) remarkably well. The PG energy scale, e g (dominated by the anti-nodal parts of the Brillouin zone) extracted from the analysis of ρ c ( T ) data was found to decrease almost linearly with increasing hole concentration, p , in the CuO 2 planes. We have also discussed about the possible origin of more conventional behavior of ρ c ( T ) observed in the deeply overdoped side of the T – p phase diagram in this paper.

An efficient appliance for low voltage DC house

Abstract: Kitchen appliances consume large amount of energy in residential houses. By using efficient appliances energy losses can be reduced. Most of the household appliances use DC internally except some appliances such as stove, refrigerator, dishwasher and microwave oven. The refrigerator and stove is one of the high power consuming kitchen appliances and it consumes large amount of energy. This work investigated on energy efficient home appliance design to run on low DC voltage and the purpose is to reduce energy consumption and losses. A combined refrigerator stove unit is designed to run on low voltage DC. The system is simulated with Matlab / Simulink and finally a prototype is built to analyze the performance.

Comparative Antioxidant Potential of Different Extracts of Celastrus paniculatus Willd. Seed

Abstract: The objective of the present study was to evaluate the comparative antioxidant potential of methanol, ethyl acetate, pet ether and water extracts of Celastrus paniculatus seed. Antioxidant activity was evaluated by using total phenol and flavonoid content determination assays, total antioxidant capacity, 1,1-diphenyl-2- picryl-hydrazil (DPPH) free radical assay, Reducing power assessment, Nitric oxide (NO) scavenging assay and Cupric ion reducing capacity assay (CUPRAC method). The extracts showed moderate antioxidant activity in a dose dependent manner. The extracts were found to contain phenolics and flavonoid compounds. In DPPH radical scavenging assay, ethyl acetate extract had the lowest IC 50 value (585.58μg/ml) compared to ascorbic acid. In nitric oxide scavenging assay IC 50 value was found to be 122.99μg/ml, 320.54μg/ml, 601.81μg/ml and 206.37μg/ml respectively for the Water, Methanol, Ethyl Acetate and Pet Ether extracts compared to 6.83μg/ml which was the IC 50 value for the reference ascorbic acid. The extracts also showed good reducing power. The results of the present study indicate that the extracts possesses significant antioxidant potential of which ethyl acetate extract is the most promising one and possess highest antioxidant potential. Key Words: Celastrus paniculatus ; antioxidant; DPPH; NO scavenging; CUPRAC; ROS. DOI: 10.3329/sjps.v3i1.6802 S. J. Pharm. Sci. 3(1): 68-74

A very low power and high throughput AES processor

Abstract: In this paper we presents the design of a very low power and high throughput AES processor. A sophisticated AES algorithm without sacrificing its security features, throughput and area is used to design the processor. Due to the optimization of the algorithm and a number of design considerations, the processor shows its superiority over other AES processors. The proposed processor is simulated on the FPGA platform and Quartus II development software of Altera device of family Stratix II GX is used to simulate the design. A Power Play Early Power Estimation Tool is used to approximate the power consumption of the proposed processor. Later on the more reliable power analysis tool named Power Play Power Analyzer is used to estimate the static and dynamic power dissipation in the Processor. The high level of system integration along with very low power consumption and high throughput makes the AES processor an ideal choice for a range of application including small computing devices, smart card readers and network applications like WLAN, WPAN, WSN etc.

Prospect of a Pico Hydro power plant based on irrigation pump in perspective of rural areas in Bangladesh

Abstract: This Paper presents the design aspects of a Pico Hydro power plant (PHP) using the water from conventional irrigation pumps, which are widely used for agricultural purposes in the rural areas of Bangladesh. In addition, it also presents the viable prospects of PHP as an electricity generating system in perspective of Bangladesh. Bangladesh, being a developing country with perpetual shortage of electricity and facing numerous hardships towards generating it, is constantly in search of an alternative source of energy, in which case, Renewable Energy has gained quite a reputation for. A conventional irrigation pump is the main source of water for our proposed design. The hydro energy from the flow of water rotates a particularly designed Pelton turbine, which is one of the major parts of our PHP. In addition, the proposed PHP unit consists of a mechanical shaft connected to a larger wheel, fan belts, one single phase permanent-magnet generator (PMG) and a simple battery charging system for charging batteries for different electrical appliances.

Preparation and Evaluation of Cellulose Acetate Phthalate and Ethyl cellulose based Microcapsules of Diclofenac Sodium using Emulsification and Solvent-Evaporation Method

Abstract: Diclofenac sodium (DS) microspheres were prepared with two different polymers, ethyl cellulose (EC) and cellulose acetate phthalate (CAP). Emulsification-solvent evaporation method was used to prepare the microspheres. Liquid paraffin containing 1.5% (w/w) span 80 was the external phase and acetone-polymer solution was the internal phase. EC and CAP, both as single and as mixture, were used to encapsulate DS. EC microspheres were more spherical in shape and showed more entrapment efficiency than CAP microspheres. The size of the microspheres varied between 560-920 μm and as high as 90% loading efficiency was obtained. In vitro release study was carried out in 0.1 N hydrochloric acid solution (pH 1.2) for first 2 hours followed by in phosphate buffer solution (pH 6.8) for next 4 hours. After first 2 hours of dissolution in 0.1 N hydrochloric acid, EC microspheres released 24% of DS whereas CAP microspheres released only 2% DS. After 4 hours of dissolution in phosphate buffer, 60% DS was released from EC microspheres and almost all drug was released from CAP microspheres. Combination of EC and CAP showed more sustaining action than the individual polymer in both the dissolution media. DS release from EC microspheres followed Higuchi model whereas CAP microspheres followed first order model. Key word: Diclofenac sodium; microsphere; Ethyl cellulose; Cellulose acetate pthalate DOI: 10.3329/dujps.v9i1.7428 Dhaka Univ. J. Pharm. Sci. 9 (1): 39-46 2010 (June)

Golden Ratio, the Phi, and Its Geometrical Substantiation

Abstract: Golden ratio is often denoted by the Greek letter, usually in lower case, Phi (ϕ) which is an irrational mathematical constant, approximately 16180339887 Because of its unique and interesting properties, many mathematicians as well as renaissance artists and architects studied, documented and employed golden section proportions in remarkable works of sculpture, painting and architecture Robot sizing especially for the Humanoid Robot, Phi is considered as the key to achieve the human friendly look The ratio also plays an enigmatic role in the geometry and mathematics The basic concept of golden ratio and its relation with the geometry are represented and described in this paper The paper also explains about the structure and construction strategies of various dynamic rectangles by establishing some relations and dependencies with each other The main contribution of the paper is to study about the validation and substantiation of the Equation of Phi based on classical geometric relations The technique can be considered as an interesting strategy to prove the Equation of Phi

Inside Story of Microcredit in Bangladesh: An Empirical Investigation on the Role and Productivity

Abstract: The microfinance movement that began as a programme of actionresearch in a small village by Professor Muhammad in 1976 has quickly become a global phenomenon, attracting more than 100 million borrowers world-wide. The movement has been hailed as an innovative tool for poverty eradication.

A Semi-Distributed and Mobile Agent based architecture for load balancing of heterogeneous wireless networks

Abstract: Heterogeneous wireless network pose many interesting research challenges. Among them, resource management and load balancing in such a hybrid environment is still an open problem. Consider these issues an efficient semi distributed load balancing architecture for multiple access networks is introduced in this paper. Since both centralize and distributed architecture has their own pros and cons, in partially distributed architecture we successfully overcome the problem of both design. In this grid based design multiple Load and Mobile Agent Management Units is incorporated. To prove the compactness of the design signaling overhead and total processing time is calculated. And finally simulation result shows that overall system performance is improved by reducing overhead and time.

Mainstreaming Third-Sector Economics by Adopting Islamic Principles of Entrepreneurship

Abstract: The ‘private’ and ‘public’ sector economics found their own strong places to play roles in the mainstream economy. At the end, however, these two systems – the private, popularly called the first sector economy, and the public, called the second sector economy - both individually and jointly have been found seriously inadequate and incapable to ensuring wellbeing of human societies nationally and globally. Responding to such a situation a number of nonconventional approaches like cooperatives and social enterprises, waqaf, foundations, and other non-profit institutions, etc., together called third sector economy, were moved and promoted to ensure social justice and wellbeing of mankind. Initially it emerged as a make-up and defensive strategy of the market-state model to meet the minimum of unmet requirements in the sectors where the market and state have grossly failed. It, thus, played only a subordinate role. As a result, it could not help much to solve the problem of economic inequity, concentration of wealth, and social divides. However it is strongly felt that a broadly based third sector economic model with both not for-profit business like enterprises and for-profit businesses blended with social justice is necessary to play its role as a mainstream model not only for poverty alleviation but also for economic growth to bridge the economic and social divides. Mainstreaming the third sector is the urgent call of the day. Islamic entrepreneurship, which is basically a community-centric mode of business initiative, is an antidote to the problem of intolerable economic and social dualism in the economies. It is a natural strategy against all forms of capitalist exploitations, like in the past through European colonialism and now through American led terrorism, to control resources. Accordingly it is the natural model for solving the problems of economic inequity, concentration of wealth, and social divides. Therefore, this study finds the Islamic mode of entrepreneurship as most suitable and effective for widening and mainstreaming the third sector economics, more particularly in the developing countries. Johor Corporation (JCorp) in Malaysia and Sheba Polly in Bangladesh are examples of two types of Islamic style third sector enterprises – one is staunchly business like initiative and the other is cost based charity initiative for social benefit. For the development and promotion of the community-centric third sector economics model, the paper recommends for urgently establishing a research and development centre on third sector economics preferably under an Islamic Research and Development Institute in any reputed university.

Effect of Reynolds and Prandtl Numbers on Mixed Convection in an Obstructed Vented Cavity

Abstract: A numerical investigation is conducted to analyze the steady flow and thermal fields as well as heat transfer characteristics in a vented square cavity with a built-in heat conducting horizontal solid circular obstruction. Hydrodynamic behavior, thermal characteristics and heat transfer results are obtained by solving the couple of Navier-Stokes and energy equations by using a weighted residuals Finite element method. The computation was made for different Reynolds number, Prandtl number ranging from 50 to 200 and from 0.71 to 7.1 at the three different convective regimes. Three different regimes are observed with increasing Ri : forced convection (with negligible free convection), mixed convection (comparable free and forced convection) and free convection dominated region (with higher free convection). The results are presented to show the effects of the Reynolds number, Prandtl number on flow pattern, thermal field and heat transfer characteristics at the three convective regimes. It is found that the flow and thermal field strongly depend on the Reynolds number, Prandtl number as well as Richardson number. As the Reynolds number and Prandtl number increase, the heat transfer rate increases but average fluid temperature in the cavity and temperature at the cylinder center decrease at the three convective regimes. Keywords : Mixed convection; Finite element method; Obstructed vented cavity; Prandtl number. © 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi:10.3329/jsr.v3i2.4344 J. Sci. Res. 3 (2), 271-281 (2011)

A New Approach To Develop An English To Bangla Machine Translation System

Abstract: Machine translation (MT) is always a challenging job. It is really difficult to build up a complete machine translation system for natural languages. Machine translation includes natural language understanding and generation. The proposed system represents a new solution for building a MT system for English to Bangla translation, by modifying the rule-based transfer approach of MT system. In machine translation the searching of word from the lexicon is a compulsory task, here this searching stage is utilized efficiently by proposing an intelligent integer based lexicon system, consists of a number of separate lexicons and an algorithm is also developed for searching words from the lexicon in order to accomplish the basic steps of machine translation. Keywords: English to Bangla; Intelligent; Lexicon; Machine Translation; Parsing; Semantic DOI: http://dx.doi.org/10.3329/diujst.v6i1.9332 DIUJST 2011; 6(1): 36-42

Low cost digital stroboscope designed to measure speed of motor optically

Abstract: Motor performance is an important consideration for production in industry. Speed of the motor is a top most parameter of motor performance. There are several products available in the market for speed measurement but they are costly. In this paper an attempt has been made to design and construct a lower cost and higher accuracy digital stroboscope which will be compatible with those of the available in the market. It is also shown that the speed in RPM in an LCD display and finally described how it can be used to measure the rotational speed of a motor or wheel without connecting it with the shaft. Here it generates variable frequency signal, then flashes on the motor shaft and tries to synchronize with the rotating frequency of motor. When two frequencies are matched, then the motor shaft becomes almost standstill. Now the required speed is calculated in RPM using the generated signal through microcontroller. Output of frequency generator is fetch as input of the microcontroller and after manipulating the data microprocessor run the LCD to show the desired speed of motor in RPM.

Processes and Achievements of Malaysia's Economic Globalization

Abstract: Integration of the national economy with global economy is the natural outcome and the end result of economic development processes in any nation. In the political economy of the world with unequal nations and imperfect competition the north-pushed capitalist globalization is a suspect of deception for developing countries. The capitalist globalization is a project of market dogmatism founded on the Darwinist social philosophy of ‘survival of the fittest’ – the law of Jangle. It is inherently a scheme of yielding disproportionately large benefits for the efficient industrialized nations. This paper analyses the structure and management of Malaysia’s economic globalization and studies its achievements from national and international contexts. It has used a variety of econometric and statistical tools such as the augmented Dickey-Fuller test, Log-linear Regressions, Chow breakpoint test, and CUSUM test. The results reveal that globalization has made significant achievements in terms of most of the national macroeconomic goals. However, in terms of the international political economy it has failed unexpectedly. Results of the income convergence analyses show that it has failed to reduce Malaysia’s income gaps with USA and Japan, its two major trading and investment partners. It contradicts the general findings of the income convergence studies that the lower income industrializing countries are catching up to the higher income industrialized countries and slowly narrowing the income gap between them. This result, therefore, tends to suggest that even a guided and regulated globalization, like that of Malaysia, will have the tendency to yield relatively more benefits to the developed industrialized economic partners and contributes to the widening of the income gaps between them. The paper concludes that because of the blind eye of globalization to the needs and aspirations of the developing economies, these countries must pursue globalization only, cautiously, rationally, selectively, and never wholeheartedly.

In vitro study on interaction of ketotifen fumarate with metformin hydrochloride

Abstract: This article was published in Latin American Journal of Pharmacy [© 2011 Latin American Journal of Pharmacy] and the definite version is available at: https://goo.gl/XOJ7tm

Microcredit - A More Credible Social than Economic Program in Bangladesh

Abstract: Calculated under the framework of economic-profit counting, the productivity of microcredit in Bangladesh is found very low. In this survey about 48% of the borrowers had to compromise their normal wages for self-employed labor to be able to pay the high interest for the credit. Similarly its social productivity is also found marginal. However, about 90% of the borrowers felt comfortable with microcredit even at so high interest rate seemingly to avoid losing or compromising their social and political empowerment at the hands of the local moneylenders or relatives. Borrowers give high value to their socio-political empowerments and are ready to compromise normal wages for their selfemployed labor. In the game of political economy of credit for the poor, microcredit is seen as a means of protecting and enhancing socio-political empowerments of the low income and distressed people in the society and is appraised as a credible social than economic institution.