Browsing by Author "Rahman, Md. Lutfor"

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A Study of Marketing Mix Adaptation Requirement with Export Performance by the Domestic Exporters of Leather Goods to the International Market
(Journal of Business and Technology, 2006-07) Karim, Khondaker Sazzadul; Rahman, Md. Lutfor
According to the MIXADAPT model, export performance depends upon the marketing mix adaptation. Many studies found the existence of a mostly positive effect of marketing mix adaptation on export performance, even though controversies still exist regarding the determinants of export performance and whether there are other internal and external determinants other than marketing mix that have an impact on export performance. In the case of the leather industry in Dhaka city, no significant relationship was found between export performance and adaptation of the marketing mix. Price adaptation is the only variable that significantly affects export performance. The findings suggest further research incorporating other internal and external variables such as management attitude and perceptions, management characteristics, industry characteristics, foreign market characteristics, and domestic market characteristics to be incorporated with the MIXADAPT model to explain the export performance of the leather industry in Bangladesh.
Analysis on Viscous Incompressible Thermal Flow on a Ventilated Enclosure by Finite Element Method
(University of Rajshahi, 2014) Ahammad, Main Uddin; Rahman, Md. Lutfor; Rahman, Md. Mustafizur
Heat transfer in enclosure in which the influence of free (natural) and forced convection (mixed convection) are of comparable magnitude occurs frequently in engineering situations. The applications include the heat transfer improvement in heat exchanger devices, design of solar collectors, thermal design of building, air conditioning, cooling of electronic circuit boards, lubrication technologies, chemical processing equipment etc. Convection in ventilated enclosures containing obstruction has gained recent research significance as a means of heat transfer enhancement. The mathematical model of the present problem is governed by the couple equations of conservation of mass, momentum and energy. Discretization of the governing equations is achieved using a finite element scheme based on the Galerkin weighted residuals method. Then Newton–Raphson iterative algorithm is used to obtain the solutions of the obtained algebraic equations. Comparisons with previously established on particular cases of the problem are performed and the results show excellent agreement. Firstly, for mixed convection flow the effect of inlet and outlet position of a square ventilated enclosure with a centered heat generating solid body has been investigated. The bottom wall of the enclosure is kept at a uniform constant temperature, while the rest three walls of the enclosure are assumed adiabatic. A transverse uniform magnetic field is imposed in the horizontal direction normal to the right vertical wall. An external flow enters the cavity through an inlet opening whereas it exits via another outlet opening. After that, the effect of pertinent parameters in the considered flow problem in this thesis was analyzed for three different types of internal cavity solid body (heat generating, heat conducting, adiabatic) for a selected BT (bottom inlet and top outlet) configuration. Obtained results from the present study are presented in the form of streamlines, isotherms, average Nusselt number along the bottom heated surface and average fluid temperature in the cavity for each of four configurations as well as three different confined blocks for the pertinent parameters namely Reynolds number, Prandtl number, Hartmann number, solid-fluid thermal conductivity ratio, solid block diameter at the three values of Richardson number, varying from 0.1 to 10. The computational findings of this thesis reveals that both the flow and the thermal fields strongly depend on the parameters Reynolds number Re, Prandtl number Pr, Hartmann number Ha at the three convective regimes (Ri = 0.1, 1, 10). The centered solid body of the enclosure influences the steamlines pattern slightly for the smaller dimension of the block D whereas it has a considerable disparity in temperature distribution inside the enclosure. It is also observed that the solid-fluid thermal conductivity ratio K have insignificant effect on the flow fields and have significant effect on the thermal fields at the three convective regimes.
Analytical Invcstlgations in Tubulent and IVIlID Tttdmlent Flow
(198) Rahman, Md. Lutfor; Sarker, M.Shamsul Alam
The thesis entitled "Analytical Investigations in Turbulent and MHD Turbulent Flow" is being presented for the award of the degree of Doctor of Philosophy in Mathematics. It is the outcome of my research conducted in the Department of Mathematics, Rajshahi University during the year 1994-1998 under the guidance of Dr. M. Shamsul Alam Sarker, Department of Mathematics, Rajshahi University, Rajshahi-6205, Bangladesh. The whole thesis has been divided into six chapters. The first is an introductory chapter and gives the general idea of turbulence, magnetohydrodynamic turbulence and its principal concepts. Throughout the work we have considered the flow of fluids to be isotropic and homogeneous. The notions generally adopted are those used by Batchelor, Chandrasekhar and Deissler in their research papers. Number inside brackets [ ] refer to the references which are arranged alphabetical at the end of the thesis. In the second chapter, we have derived the equation for tl1e rate of change of magnetic field covariance in MHD turbulent flow. 111e result shows that the defming scalars of the magnetic field covariance depend on the defining scalar H of two point magnetic field correlation. In tl1e third chapter, the decay of turbulence at ti.mes before the final period in presence of dust particles is studied. Two and three point correlation equation is used to obtain a relation for tl1e triple correlations and the equation is made detenninate by neglecting the quadruple correlations. Finally, we obtained tl1e energy decay law of dusty fluid turbulence before tl1e final period. In the fourth chapter, we have studied the decay of dusty fluid MHD turbulence before the final period. Tirree point correlation equation is used to obtain a relation for the triple correlations applicable at times before the final period. In this case the equation is made determinate by neglecting tl1e quadrnple correlations. Finally, we obtain the energy decay law of dusty fluid MHD turbulence at times before the final period.-------
Comparative Studies on the Nutrient Content of Five Varieties of Rice Brans and Purification, Characterization and Structure Function Analysis of Proteins from the Best Quality Rice Bran
(University of Rajshahi, 2007) Rahman, Md. Lutfor; Absar, Nurul
Five varieties of rice bran were analyzed to obtain comparative data on their chemical compositions and nutritive values. Rice bran oils were also characterized with respect to their physical and chemical properties. The results indicated that moisture, ash, total soluble solid and crude fiber contents of the different varieties of rice bran were in the ranges of 9.98-10.90%, 9.45-11.12%, 10.06-11.25% and 9.18-10.35% respectively. The ranges in the values of total protein, water soluble protein, dry matter, polysaccharide, total sugar, reducing and non-reducing sugar compositions of rice brans were betweenl2.45- 14.06%, 3.20-4.71 %, 89.10-90.02%, 10.95-12.86%, 4.35-5.04%, 1.08-1.45%, and 3.10-3.96% respectively. Some minerals such as potassium, calcium, magnesium, sodium, phosphorus, Sulphur, iron, zinc and manganese are available in all the varieties of experimental rice brans. Vitamin B1 and vitamin B2 contents of rice brans were found to be ranged from 2.98-3.81 and 0.61-0.95 mg/100 g respectively. Twelve amino acids were detected in all the five varieties of rice bran in the total form by paper chromatography. Among the variety IRRI-28 contained relatively higher amount of amino acids. Rice bran contained about 14.95-16.16% oil. The bran oils were also characterized with respect to their physico-chemical properties such as specific gravity, refractive index, smoke point, flash point, fire point, saponification value, iodine value, peroxide value, acid value, %FFA and unsaponifiable matter. Triglyceride diglyceride monoglyceride, and non-glyceride are the constituents of bran oils were found to be varied from 91.76-93.08%. l.51-2.30%, 1.45-1.96% and 3.63-5.24% respectively. Rice bran oils contained mostly unsaturated fatty acids which was varied from 7 l.06-74.95%. The total lipids were fractionated into lipid classes by silicic acid column chromatography and the bran oil contained triglyceride, hydrocarbon, free sterols, glycolipid, phospholipid arid partial glyceride. GLC analysis of the oil indicated palmitic, stearic, oleic and linoleic acid, as a major fatty acid in all the varieties of rice bran oil. On the other hand, linolenic, myristic and arachidic acid were also detected in small amount.
Customers' Perception about the Determinants of Service Quality of Foreign and Domestic Banks: An Empirical Study on Bangladesh
(Journal of Business and Technology (Dhaka), 2011-01) Siddique, Abu Bakar; Karim, Khondaker Sazzadul; Rahman, Md. Lutfor
This paper investigates the determinants of perceived service quality among the customers of domestic and foreign banks in Dhaka, Bangladesh, using a modified version of the SERVQUAL model. It finds that, in general, the foreign banks provided marginally better measures in most dimensions than domestic banks. For domestic private banks, reliability, communication, credibility, security, and tangibility are found to affect service quality significantly. On the other hand, for foreign banks, reliability, credibility, and tangibility are the only significant factors affecting their service quality.
Design and Optimization of VCO PLL Frequency Synthesizer
(Bangladesh Electronics and Informatics Society, 2010-06-02) Rahman, Md. Lutfor; Bhuyan, Muhibul Haque
Today's mobile communications systems demand higher communication quality, higher data rates, higher frequency of operation, more channels per unit bandwidth, low power consumption, and smaller size. All these constraints combine to make the whole design of the communication systems including components selections and evaluation quite challenging. One portion of this design is the synthesized oscillator. Typically, synthesized oscillators combine a Voltage-Controlled Oscillator (VCO) with a Phase-Locked Loop (PLL) IC, frequency reference (e.g., Crystal/TCXO), and a loop filter. This paper describes the evaluation of the PLL and VCO and relates those evaluations to information that will allow the circuit designer to optimize the whole oscillator design including the loop filter. Few experimental results are also presented. It is found that the designed circuit works very well.
Determining the Dimensions of Quality Education in Public and Private Universities in Bangladesh: An Empirical Study
(Journal of Business and Technology, 2008-07) Karim, Khondaker Sazzadul; Rahman, Md. Lutfor
Ensuring quality education is a prerequisite for sustainable development. Studies suggest the inclusion of relevant variables in finding the determinants of quality tertiary education, as the customers are well-diversified students, their parents and guardians, and academic and administrative staff, each having different needs and objectives. Thus, this paper tries to incorporate forty-nine “quality characteristics,” previously found significant by various studies, with a few uniquely appropriate local characteristics. The characteristics have been grouped under six dimensions: tangibility, competence, attitude, content, delivery, and reliability. Based on the opinion of the “student,” a class of customers, the authors conclude that both for public and private universities, the quality of education mainly depends upon the competence of their academic and administrative staff, the content of their curriculum, and the reliability of the institution.
E-commerce and its evolution and growth in time of corona in Bangladesh
(BRAC University, 2021-01) Rafa, Jaina Humayra; Rahman, Md. Lutfor
In this report I tried to explain ecommerce very carefully and its impact on both business people and consumers. The whole world is now paying much attention and showing interest on ecommerce, Covid19 gave an extra push to it. Bangladesh is still very new on ecommerce. It is a challenging industry for Bangladesh .I tried to explain the whole scenario of ecommerce in Bangladesh, what it was like when it was just starting and what it is the current situation now. How covid19 effects the Bangladesh ecommerce industry is also explained here. Lastly I finished my report by giving some recommendations how the situation in our country can keep improving and what are my last thoughts on this.
Environmental Impact of Teesta Barrage on the Command Area in Bangladesh
(University of Rajshahi, 2014) Roy, Sunil Chandra; Azad, Md. Abul Kalam; Rahman, Md. Lutfor
Bangladesh Water Development Board (BWDB) has implemented Teesta Barrage Irrigation Project in 1994. The objectives of this mega project were flood control and creation of supplementary irrigation facilities for an area of 1,54,250 ha under the greater Rangpur district. This study was conducted to identify the environmental impact of Teesta Barrage Irrigation Project on agriculture, groundwater and rainfall in the project area by trend analysis of two periods: before and after project. For trend analysis 22 years (1983- 2004) ground water table and 20 years (1984-2003) rainfall data were used. From ground water data analysis, it is found that seasonal mean ground water table was up in post-project period (1994-2005) of Teesta Barrage Irrigation Project and level was down in pre-project period (1982-1993). The mean differences of ground water table of these two periods was significantly different (0.01% level) in all six seasons of summer, rainy, autumn, late autumn, winter, spring and summer. Therefore, it is concluded that Teesta Barrage Irrigation Project has positive impact on ground water resources and improved the ground water table in the command area. From rainfall data analysis, it is observed that mean rainfall in post-project period (1994-2003) of Teesta Barrage Irrigation Project was increased in all six seasons in the study area compare to mean rainfall of pre-project period (1984-1993). However, the mean difference rainfall between the periods (1984-1993) & (1984-2003) was found significant only in winter season. Therefore, it is concluded that Teesta Barrage Irrigation Project has positive impacts on rainfall pattern in the project area. As per respondents’ opinion, Teesta Barrage Irrigation Project has also positive impacts on the following environmental components. i) Increased food production for HYV-Boro and T-aman cultivation ii) Increased fruiting plants and social forest plantation iii) Increased drinking water availability iv) Decreased water born diseases v) Improved income and standard of life of local people However, Teesta Barrage Irrigation Project has reduced the open fisheries in the project area. Jute and aus cultivation are dramatically reduced in this area.
Experimental Investigation on Thermal Performance of a Closed Loop Pulsating Heat Pipe without Fin and with Fin Structure
(American Journal of Mechanical Engineering(Science and Education Publishing), 2016) Rahman, Md. Lutfor; Kader, Md. Faisal; Rahman, Md. Zakaria; Ali, M.
Pulsating Heat Pipe (PHP) is a new and emerging cooling technique in the field of thermal management especially in microelectronics. To fulfill the increasing demand of power electronic applications, PHP is a proven technology which works on principle of self-oscillation of the working fluid and phase change heat transfer phenomenon in a capillary tube. In this paper, the thermal performance of a closed loop pulsating heat pipe (CLPHP) without fin and with fin at the condenser section by using Acetone and Water as working fluid has been investigated experimentally. The effects of different parameters include the filling ratios (from 40% to 70% in steps of 10%), the inclination angles ( 0°, 30°, 45°, and 60°), and at various heat input (10 to 10W in the steps of 10W) has been investigated thoroughly. In this study CLPHP is made from long capillary copper tube with inner diameter of 2.0 mm and outer diameter of 3.0 mm. The heat pipe is bent into eighth number of U-turns and divided into three sections, evaporator section (50 mm), adiabatic section (120 mm) and condenser section (80 mm). Adiabatic section is maintained by using aluminum foil surrounded by appropriate insulation. The result shows that, the thermal resistance decreases as heat input increases. But at low heat input i.e. up to 60W, the thermal resistance decreases rapidly and the PHP performance is more sensitive to the inclination angle whereas high heat input i.e. above 60W, the thermal resistance decreases slowly and comparatively less independent to the inclination angle. Evaporator dry out is occurred for acetone at low filling ratio with 40% and 50% at heat input 40W and 50 W respectively. CLPHP with fin structure shows better performance than the CHPHP without fin structure at high heat input. Acetone with 70% filling ratio and water with 50% filling ratio shows the best performance at 0° inclination angle for both structures.
KEITHLEY 6517B Electrometer
(BRAC University, 2016-10) Shuva, Sudipta Das; Rahman, Md. Lutfor
Keithley 6517B electrometer is a multifunctional electrometer which usually works with low current and high resistance. This electrometer can be controlled through interfacing. Labview software was used to interface this instrument. Using the Labview program and the electrometer electrical properties of electronic devices for example transistors, diodes, resistors etc. can be measured with more accuracy. By the end of the internship properties of several transistors, diodes and resistor were measured. In future the program that has been developed can be used further for sorting out the properties of other electronics appliances too.
Linearization of Voltage-Controlled Oscillator by Microcontroller Based PLL Frequency Synthesizer
(Faculty of Applied Science and Engineering, Shahjalal University of Science and Technology, Sylhet, Bangladesh, 2011-01-11) Rahman, Md. Lutfor; Bhuyan, Muhibul Haque
Today's mobile communications systems demand higher communication quality, higher data rates, higher frequency of operation, more channels per unit bandwidth, low power consumption and smaller size. One important part of the communication systems design is the synthesized oscillator. Typical synthesized oscillators combine a Voltage Controlled Oscillator (VCO) with a Phase-Locked Loop (PLL) IC, frequency reference (e.g. Crystal/TCXO) and a loop filter. This paper describes the evaluation of the PLL and VCO and relates those evaluations to information that will allow the circuit designer to optimize the whole oscillator design including the loop filter. Few experimental results are also presented. It is found that the designed circuit works very well. After the synthesizer has been designed and built, the synthesizer is locked very sharp and correctly in time. The spectrum contains many spurious frequencies. The loop bandwidth is higher as expected. The phase noise is lower than expected. So, the noise of the synthesizer keeps them as small as possible. In the PLL system to change the receiving frequency from 38.445 MHz to 38.429 MHz and now we have perfect reception.
Numerical Investigation of Shock Wave Decay Phenomenon in Free Atmosphere
(American Journal of Mechanical Engineering(Science and Education Publishing), 2016) Kader, Md. Faisal; Ehsan, M. Monjurul; Saklayen, Golam; Sadi, KMR; Rahman, Md. Lutfor
A numerical investigation of shock wave propagation in open atmosphere is presented to observe the shock wave decaying phenomena due to expansion in the free space. By examining different parameters (Pressure, velocity and density) of the upstream and downstream flow of the wave, it is possible to estimate the decaying phenomena of the wave strength. The governing equations described for compressible inviscid flow are discretized by the finite volume method. The three-dimensional Euler equations are solved by shock capturing method. Shock wave of Mach number 1.5 is allowed to flow through a shock tube and at different time intervals (35 μsec, 96 μsec, 121 μsec and 190 μsec), velocity, pressure and density variations along the center line of shock tube are investigated to observe the decay phenomenon across the shock front in open atmosphere.. The results have been compared with the Navier-Stokes Simulation (NS) results to establish the absence of viscous effects in the present flow. Due to absence of the solid boundary of the selected numerical domain in the free space, the fluid flow will act as nonviscous flow. The wave propagation in free space changes its propagation characteristics due to rapid expansion in all directions and at the same time the decay of the wave strength is observed.
OCCURRENCE OF GASTRO-INTESTINAL PARASITIC INFECTION IN PABNA CATTLE AT SUJANAGAR UPAZILA, PABNA, BANGLADESH
(Chattogram Veterinary and Animal Sciences University Khulshi, Chattogram-4225, Bangladesh, 2009-06) Rahman, Md. Lutfor
Examination of 109 faecal samples of Pabna Cattle at Upazila Veterinary Hospital, Sujanagar , Pabna from 12 December, 2008 to 16 February, 2009 revealed that 78.89% of the samples were positive for the gastrointestinal parasites. The occurrence of different gastro-international helminths were 29.35% Fasciola, 13.76% Moniezia,11.00% Paramphistomum,8.25% Balantidium coli,5.50% Toxocara vitulorum, 3.66% Strongyloides, 2.75% Coooperia, 1.83% Bunostomum 1.83% Entamoeba and also 1.83% Mix infestation.( Fasciola& Monneizia). Among the gastro-intestinal parasites, the infection with Fasciola in cattle remained high (29.35%). Females (87.87 %) were more susceptible to parasitic infection than male (75%). The Highest frequency of gastro-intestinal parasitic infection was recorded at the age between one to three years (83.887%). The small sized farms were more prone (84.05%) to the gastrointestinal parasite than the large farms (55.55%).
Supply chain relationship and sourcing of JMI Hospital Requisite Manufacturing Limited
(BRAC University, 2021-06) Sultana, Aynun; Rahman, Md. Lutfor
This report has been primed as a requisite of the MBA internship program. This report is based on the “Supply Chain Relationship and Sourcing of JMI Hospital Requisite Manufacturing LTD.” the major highlighted part of this report is the process and organized way of supply chain relationship and sourcing of this company. In today's global business world, supply chain management has become an essential component of any organization. Larger companies outside of Bangladesh have effective supply chain management in place to ensure that their organization is run efficiently in order to maximize profits and maintain client loyalty. The delivery chain for a handful of the outside businesses is huge. Bangladesh's supply chain management position differs from that of developed international countries. The report has been organized on the basis of my hands-on work involvement at JMI Group. JMI Group is one of Bangladesh's most exciting and rapidly growing businesses. JMI Bangla Company Ltd (later renamed JMI Syringes & Medical Devices Limited) was founded in 1999 as the Group's first SBU. China, Turkey, Japan, and South Korea have all invested over BDT 10 billion in the Group, which currently has roughly twenty-two enterprises. The JMI's ultimate purpose is to safeguard lives through manufacturing medications, syringes, and other advanced medical devices, as well as working for the benefit of humanity. JMI Hospital Requisite Manufacturing LTD. is a driving producer of Plastic, Elastic & Silicon components for restorative applications around the world. The company produces exceptionally high-quality components for therapeutic gadgets keeping up a cleanroom environment. A bunch of highly-skilled, taught & committed workers is there to deliver & convey state-of-the-art quality items. The company is working beneath the Medicate specialist of the People groups Republic of Bangladesh. The company was set up as a joint wander company with endeavors & specialized know-how brought from Korea (Sun-Myung Universal Inc.) to deliver preeminent quality items. Supply chain relationship refers to the process where the communication and understanding the process and procedure of suppliers are maintained. Sourcing indicates the medium or ways the suppliers are identified and selected. JHRML maintain a very strict and modest process and procedure for selecting the sources and keeping the relationship cordial and professional with them. Ensuring the world class product and services need the best of the best raw material supply and maintain them balanced. In this report I have tried my level best to identify and indicate the procedure of sourcing the suppliers, their qualifying standards and abilities, selection criteria and overall relationship with the organization.
Text Analysis for Bengali Text Summarization Using Deep Learning
(10th International Conference on Computing, Communication and Networking Technologies, ICCCNT 2019, IEEE, 2019-12-30) Munzir, Abdullah Al; Rahman, Md. Lutfor; Abujar, Sheikh; Ohidujjaman; Hossain, Syed Akhter
Text summarization is an approach by which the size of one or more document is shortened and the shorten passage presents the core information of the document. In this modern era of information technology, we are over flooded with online data which raised the necessity of summary of the original text. Many methods have already implemented for English text and the effort for Bengali text are gaining alongside. In this paper, we propose an extractive text summarization technique based on a deep learning model of Recurrent Neural Network (RNN) for single document summary. Our method is to classify the sentences as significant or not for the summary. We have used Long Short-Term Memory (LSTM), Gated Recurrent Units (GRU) based RNN. Between them, we found LSTM more promising and we achieved average F1 scores- 0.63, 0.59, 0.56 for Rouge-1, Rouge-2 and Rouge-3 in some respects.
The operations & supply chain management of Energypac Engineering Ltd
(BRAC University, 1/15/2021) Islam, Aynul; Rahman, Md. Lutfor
In today's global marketplace, effective supply chain management is seen as a significant competitive advantage for a business. The enterprise that conducts robust supply chain planning activities, delivers increased efficiencies. Supply chain managers plan, schedule, and control that flow of goods to help the company stay competitive and control costs. They build the bridges between suppliers, companies, and consumers. Energypac Engineering Ltd. is a major player and the largest private organization in the power sector industry of Bangladesh. Problem is Energypac plays a monopoly role in the domestic power sector market. In the local market there is no competitor at the moment. This seems to be a good sign, but has some bad impact too. Due to having no proper competition, Energypac has not really felt the importance of optimized use of its resources. In this current market, there is no room for comfort. There are competitors growing in the local market, and the market is rapidly opening up to the foreign investors. Throughout the report, the focus is to find potential improvement areas and apply my knowledge and tools for betterment of the procurement process and strategy for Energypac Engineering Limited. Firstly, I tried to figure out the problems through survey, prioritizing the list and finally propose action plan against each. Importance has been given on implementing the Enterprise resource planning (ERP) as that will solve a lot of problems, specially the inefficiency issues at Energypac.
The Spread of Primary Education: A Study of Problems and Prospects in the Garo Community of Mymensingh District.
(University of Rajshahi, 2010) Rahman, Md. Lutfor; Talukder, Md. Abdul Haye; Banu, Akter
This thesis contains a study of Problems and Prospects of Primary Education among the Garos in Mymensingh District. The Garos are an aboriginal hill tribe of Mongoloid blood and the inhabitants of the places in and around the Garo hills in the Mymensingh district of Bangladesh. Hills and forest, streams and torrents, springs and swamps, are the salient features of the Garo environment. The group which settled on and around the Garo hills was recognized as the Garos and that is why we find Garo settlements in the Districts of Mymensingh, Netrokona and Sylhet. As they are the part and parcel of our population so without their development it is impossible to progress. That is why they need proper education, because education is the key to all success and all the obstacles to life can remove in the light of education. As Primary Education is the foundation of education so at first Primary education related Problems should be finding out of the Garo Community and these problems should be solved for their better life. The main objective of Primary education is to help children developing this social sense, good manners and fair attitude towards family and society. The socioeconomic condition of the Garo Community of Bangladesh is miserable. Socio-economic condition plays a vital role in the field of education in Primary as well as at all levels of education systems. I believe this thesis will help to find out the educational Problems of Garo Community and help to contribute them to the development of the country.
Thermal Performance Analysis of a Closed Loop Pulsating Heat Pipe without Insert and with Insert
(International Journal of Engineering and Advanced Technology (IJEAT), 2016) Rahman, Md. Lutfor; Sifat, Najmus Saquib; Rahman, Md. Zakaria; Ali, M.
In this paper, thermal performance of a Closed Loop Pulsating Heat Pipe (CLPHP) without insert and with insert inside the tube has been investigated. The effect of different parameters like working fluid, the filling ratio, inclination angle and the input heat load on the thermal performance has been analyzed thoroughly. In this study, CLPHP is made from long capillary copper tubes with inner diameter of 2.0 mm and outer diameter of 3.0 mm. The heat pipe is bent into eight U-turns and divided into three sections: evaporator section (50 mm), adiabatic section (120 mm) and condenser section (80 mm). Adiabatic section is maintained by using aluminum foil surrounded by appropriate insulation. An insert made of copper wire with diameter 0.5mm is used throughout the tube of all three sections. Methanol and Ethanol are used as working fluids with different filling ratio varied from 40% to 60% in steps of 10%. The thermal resistance has been investigated with different inclination angles (viz. 0°, 30°, 45° and 60° from vertical) at various heat input from 10 to 100W in the steps of 10W. The result shows that, the thermal resistance decreases as heat input increases. CLPHP with insert structure shows better performance than the CHPHP without insert structure particularly at 45°inclination angle. CLPHP without insert structure shows better performance than the CHPHP with insert structure at 00 inclinations. Methanol with 40% filling ratio and Ethanol with 60% filling ratio shows the best performance at 0° inclination angle for CLPHP without insert structure. CLPHP with insert structure shows better performance than the CLPHP without insert structure at high heat input particularly at 45°inclination angle.
Traffic Congestion Prediction using Machine Learning
(Scopus, 2024-04-18) Kafy, Md. Arafath; Faisal, Saimon Islam; Rahman, Md. Lutfor; Moni, Raka; Shanmuganathan, Harinee; Raza, Dewan Mamun
Due to the world population growing rapidly over time, the number of personal and local vehicles are increasing which is one of the main causes of high traffic on the roads. For high traffic, the average speed of vehicles is decreasing which is known as traffic congestion. It is a very common and alarming problem in today’s world. Due to traffic congestion, civilians are facing different problems in this 21st century. Time is a precious thing and traffic congestion is killing the most precious times of our lives. In this paper, the authors aimed to offer a traffic congestion prediction model that will help to predict the traffic congestion of a particular area in a definite time period. During working with machine learning models or algorithms there is a concern about the accuracy of the result. To overcome this problem, 5 different machine learning models which are used decision tree, random forest, logistic regression, SVM, and MLP to predict the congestion rate. The authors compared those models with each other and calculated the mean absolute error for each of the models so that the prediction can be more accurate. Efforts are made to alleviate the traffic congestion reducing commute times and lower carbon emissions and to enhance the overall quality of life in cities.