Engineering International

9-20

Authors: Nguyen Thanh Hao

This paper presents development of k- turbulence model which can be applied for non-homogeneous two-phase turbulent flows. The improvement of governing equations of k- turbulence model is based on the decomposition of the two-phase flows into the gas phase and the second phase. Thus, the turbulent kinetic energy k and the turbulent dissipation rate  variables in k- two-equation model are substituted by the turbulent kinetic energy kg of the gas phase, the turbulent kinetic energy kp of the second phase, the turbulent dissipation rate g of the gas phase and the turbulent dissipation rate p of the second phase. The new turbulence model is kg-kp-g-p four-equation model which can be used to solve all of two-phase flows in nature studies and engineering applications.

28-37

Authors: Md. Alamgir Kabir; Rumelia Murshed; Ummul Husnaeen; Zahid Hasan Mahmood

Electronic devices and integrated systems are reduced to the size of micron and nanometer level and it becomes particularly important to predict the thermal transport properties of the components. Because of a unique structure and novel properties of carbon nanotubes (CNTs) have attracted significant attention. In this article, thermal transport properties of single wall CNTs (SWCNTs) are introduced. Combining equilibrium and non-equilibrium molecular dynamics with carbon potentials, we have studied the thermal conductivity of carbon nanotubes and its dependence on temperature. Phonon conduction depends on band gaps as well as thermal contact resistance of metallic CNTs, governed by phonon scattering and it shows evidence of 1-D quantization of the phonon band structure. We have studied here the thermal conductivity of single wall nanotubes dependence on chirality structure, dimensions of tubes, defects and vacancies in tubes. We found that the single wall carbon nanotubes have very high thermal conductivity comparable to diamond crystal and in-plane graphite sheet.

43-62

Authors: Mohammad Ali; Mohammad Shah Alam

The Hall effects on the steady MHD boundary layer flow of an incompressible fluid of combined heat and mass transfer over a moving inclined plate in a porous media with suction and viscous dissipation has studied. An external magnetic field is applied perpendicular to the surface and the fluid motion is subjected to a uniform suction and injection. A closed form solutions of the equations governing the flow are obtained for the velocity, secondary velocity, and temperature and concentration profiles. The dimensionless governing equations are solved using R-K method along with shooting technique. The velocities, temperature and concentration profiles are presented graphically for different values of governing flow parameters. The results presented graphically illustrate that primary velocity field decrease due to increase of magnetic parameter, angle of inclination, permeability parameter and suction parameter while secondary velocity also decrease for magnetic parameter, Hall parameter and permeability parameter .Other parameters increase the velocities of the fluid flow. Temperature field increases in the presence of Magnetic parameter, Grashof number, Modified Grashof number and permeability parameter and decreases for Prandlt number and suction parameter. Also, concentration profiles decreases for increasing the values of magnetic parameter, Hall parameter, Schmid number and suction parameter but there is no effect on concentration of the remaining parameters. Also the skin friction coefficient, the local Nusselt number and the local Sherwood number are presented in Tables 1-3.

9-17

Authors: Md. Aminul Islam; M. Saidul Islam

This review explores the recent development in the synthesis process of platinum nanoparticles by electro deposition method. Various developed supporting electrodes used in synthesis process of platinum nanoparticles have been discussed. It is possible to control the particle size by adjusting electrolysis parameters and to improve homogeneity of platinum particles by changing the composition of electrolytic solutions. Various electrolytic compositions also discuss briefly for single or mixed electrodes.

27-39

Authors: Meles Mekonen; Kindie Tesfaye; Wondimu Bayu

Vertisols cover large part of the high rainfall areas of Ethiopia. However, the potential of these soils is not well exploited because of heavy water logging during the main rain season. A study was conducted to investigate the interactive effects of soil drainage and fertilizer application on the productivity of Vertisols. Factorial combinations of four planting beds (Broadbed and furrow (BBF) with 100 cm bed size, broadbed and furrow with 80 cm bed size, ridge and furrow (RF) with 30 cm bed size, and flatbed) and two fertilizer levels (unfertilized and fertilized with 64 kg N ha-1 & 46 kg P2O5 ha-1) in RCBD were experimented for the sustainable use and improved productivity of Vertisols in Northeastern Ethiopia in the 2006/2007 cropping season. Results revealed that ridge and furrow bed (RF) drained more excess water than the broadbed and furrow beds (BBF) and the flatbed (F), but with yield penalties. Soil drainage using broadbed and furrows (BBF) and nitrogen and phosphorus fertilization reduced days to heading and maturity by 12 and 15%, respectively. The broadbed and furrow and the nitrogen and phosphorus fertilization package increased grain yield by 90%, grain nitrogen and phosphorus uptakes by 183 and 252%, and stover nitrogen and phosphorus uptakes by 152 and 121%. Thus, planting in broadbed and furrows (BBF), disregard of the bed size, with fertilizer application is recommended for bread wheat production on vertisols in Northeastern Ethiopia.

48-60

Authors: Md. Masud Alam; Philippe Quevauviller

Until 90, water management plans in Bangladesh focused mainly to controlling floods and facilitates drainage and irrigation which were segregate plans, and caused detrimental effects of other sectors such as water supply, sanitation, industry, fisheries plus environmental and other in-stream demands. For avoiding the fragmentation, the country has achieved a remarkable progress in Integrated Water Resources Management (IWRM) activities after the period of 90.The Flood Action Plan (FAP, 1989-1995) was the pioneer of IWRM plan in Bangladesh. In 1995, Government approved The Bangladesh Water and Flood Management Strategy (BWFMS) which was an outcome of FAP. Under the recommendation of BWFMS, Bangladesh prepared NWPo and NWMP which were the holistic and government approved documents for applying integrated water resources practice in Bangladesh.The European Union has a long experience for basin wide integrated water resources management within Europe. The European Parliament and the Council of the European Union established a framework for Community action in the field of water policy in 23 October 2000 European Union’s water policies such as the Water Framework Directive (2000/60/EC). The EU’s experience (including its 27 Member States) is based on the best scientific knowledge and available technologies. In particular, the Water Framework Directive (2000/60/EC) mainly focuses on river basin management rules and principles. It is recognized that the Water Framework Directive (WFD) might be used as an example for basin wide IWRM implementation and economic development for the developing countries like Bangladesh, taking into account their socio-economic conditions.This study will show that, how the European Union Water Framework Directive (WFD) model can be adapted for the effective implementation of integrated water resources in Bangladesh. A Common Implementation Strategy (CIS) has been depicted for sustainable IWRM in Bangladesh.

9-17

Authors: Muhammad Aamir khan; M. Rahman; M. Hanif; Muhammad Israr; S. Fahad Shah

A high performance solar collector was developed to modify agricultural building environment such as dairy, poultry farm buildings and greenhouses. Moreover it should be efficiently utilized as a solar dryer for drying various agricultural products and by products. The materials used include steel sheet with high performance of reflecting light, absorber tube, and angle iron and fully insulated drying chamber. A CPTSC was a tilted at 340south (Equivalent to the latitude of Peshawar) Pakistan. A CPTSC a total reflecting surface area was 2.9 m2 respectively. The absorber tube having a surface of 0.376 m2 was fixed in front of the reflector at the distance equal to the focal length. The total volume of drying chamber was 0.3135 m3. An experiment was conducted to enhance the efficiency of the CPTSC and two air mass flow rate treatments were tested with normal and convective mass air flow rate, 0.6 kg. Min-1 and 1.72 kg. Min-1 under the average temperature of the month (January, February and March, 2012). Moreover, the process was replicated three times under the completely randomized design. The result showed that both air mass flow rate and average temperature of the month significantly effected the efficiency of a concentrating parabolic trough solar collector. The new model of a CPTSC increased the efficiency from 8 to 25 % with increase in both air mass flow rates and average temperature of the months. Therefore it is concluded that the solar collector efficiency increased with increasing air mass flow rate.

27-38

Authors: M. Venkateswarlu; G.V. Ramana Reddy; D.V.Lakshmi

In this paper, the study of the steady two-dimensional flow of an incompressible viscous fluid with heat and mass transfer and MHD heat generation past a moving vertical plate with suction in the presence of viscous dissipation and chemical reaction is investigated. Using similarity variables, the governing partial differential equations are transformed into non-linear ordinary differential equations. These equations are then solved numerically using fourth order Runge-Kutta method with shooting technique. The flow variables are presented graphically. The graphs showed that velocity rises for increasing Grashof number, mass Grashof numer, suction, heat generation and Eckert number while reducing with increasing magnetic parameter, Schmidt number, and chemical reaction parameter and Prandtl number. Comparisons with previously published work are performed and are found to be in an excellent agreement.

49-61

Authors: Stephen Waithaka Titus; Tom Kimani Mburu; Julius Korir; Stephen Muathe

Kenya government, in collaboration with other stakeholders involved in enhancing teaching and research in the learning institutions have constructed a terrestrial fiber-optic network that connects most institutions of higher learning to enable them integrate their facilities for the purpose of sharing resources. Despite these efforts, adoption of Inter-Organization Information Systems (IOIS) by universities in Kenya is far from being realized. This creates the need of finding out the relationship between the IOIS technological factors and the IOIS adoption. This study filled this gap by analyzing IOIS technological determinants of IOIS adopting in the universities in Kenya, given the mixed results from empirical evidence on IOIS adoption generally. A logit regression procedure was used to analyze the collected data. Two factors were found to hinder the IOIS adoption, while one factor was found to motivate IOIS adoption.