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A CFD ANALYSIS FOR EVALUATING THERMAL PERFORMANCE OF EARTH AIR TUNNEL HEAT EXCHANGER
(World Journal of Engineering Research and Technology WJERT, 2024) Khan, Md. Shawkut Ali
This study investigates the use of an Earth-to-Air Tunnel Heat Exchanger (EATHE) for lowering indoor building temperatures. EATHE is a subterranean heat exchanger that uses free cooling and heating to transfer heat from the ground. A computational fluid dynamics model was created using ANSYS to examine the system's thermal efficiency and cooling capability. The model, which includes a 20-meter PVC pipe, provides cooling within the range of 10.5K to 13K for flow velocities of 3–5 ms-1 . The EATHE system's performance is largely unaffected by the underground pipe configuration, but the use of fin and fin block significantly impacts its performance. The EATHE approach exhibits significant potential for reducing the temperature within the building, with an energy payback period ranging from 5 to 9 years, subject to regional variations. Regarding the overall outcomes, it can be stated that utilizing EATHE can be a significant stride towards conserving the natural energy supply.
A Comparative Numerical Analysis for Vortex Generation on Different Geometries
(World Congress on Engineering, 2021-07-07) Zehad, Shahadat Hossain; Al Faiyaz, Sadman; Ahmed, Irfan; Raihan, Masruk
—Demand for renewable energy is escalating in the present world where power generation through generating vortex which is the whirling mass of fluid plays a crucial role in being harmless for the environment. This study is composed of analyzing different structures of vortex chamber by implementing several conditions for extracting the finest vortex generation that will be efficient enough to move the runner blades for the production of electricity. Two different geometries of vortex chamber of different diameters along with channel with a contraction section are carried out for simulation through ANSYS CFD after modeling in CAD for the comparison for most befitting vortex generation is obtained by differentiating through pressure, velocity, swirling strength, and from different diameters of the vortex chamber.
A COMPARATIVE STUDY OF MULTISTORIED BUILDING USING THE BUILDING INFORMATION MODELLING (BIM) METHOD & CONVENTIONAL MODELING METHOD
(AMERICAN INTERNATIONAL JOURNAL OF SCIENCES AND ENGINEERING RESEARCH (AIJSER ), 2022) Khan, Md. Shawkut Ali; Muhib, Md. Iftakharul
Although the construction industry has been evolving for centuries and researchers have been seeking innovative solutions for decades, diverse challenges still exist in making the construction process faster, safer, cheaper, and more accurate. Building Information Modelling (BIM) is one of the emerging tools in the field of architectural engineering to overcome these problems. Applications of this tool are very promising but its uses are still relatively limited in many countries including Bangladesh. So this study conducted a pilot project and case study analysis using Building Information Modeling (BIM) to control the project’s time and cost from Bangladesh's perspective. The objectives of this study are: (1) to examine the benefits of using BIM for project time and cost control and (2) to study the challenges of applying BIM to a case project during its life cycle. This project is being achieved by introducing Autodesk Revit MEP (2021) as the methodological tool of BIM software. The resultant data in the BIM system are extremely useful and can be generated to optimize the project delivery processes. The results also revealed that using a case study, BIM functions to help reduce costs, optimise the schedule, and make benefits for all project participants. Thus, model-based cost estimation and time schedule optimization show effective results of using BIM instead of conventional modelling methods.
A Comparative Study of Non-Frost Refrigerator Over the Frost Refrigerator in Economical and Environmental Perspective
(The Millennium University, 2020) Khan, Md. Shawkut Ali; Muhib, Md. Iftakharul
The study focuses on a comparative operation cost analysis between the non-frost and frost type refrigerator. Refrigerator is an essential equipment for food storage technique around the world. Both frost and non-frost refrigerators are widely used nowadays. However, their costing operations are not same. So the objective of this study was set to find out more economical refrigerator type that is either the frost type is economical or the non-frost type. A comparative analysis was done for both type refrigerators with the focus on the calculative results of initial cost (i.e. assembly cost, decoration cost, process cost), maintenance cost and the total 10 years’ power consumption cost. The calculated results depicted that though initial cost is found higher in non-frost inverter refrigerator, the other cost like maintenance cost as well as the overall 10 years’ power consumption cost was found to be cheaper in non-frost inverter refrigerator. Based on the experimental data it can be suggested that the non-frost with inverter type refrigerator is found to be more economical than frost type refrigerator. So it can be recommended that nonfrost with inverter type refrigerator can be used in both domestically and industrially in the minimum costing rate.
A Comparative Study of VRF Air Conditioning System over the Conventional Domestic Air-Conditioning System
(The Millennium University, 2021) Khan, Md. Shawkut Ali; Muhib, Md. Iftakharul
All over the world there is a call to encourage sustainable energy thinking and implementation. There is an urgent need to consider sustainable solutions that are able to reduce energy consumption cost. In air conditioning field, the rise of the variable refrigerant flow systems has made big progress. This study focuses on cost analysis to evaluate the economic feasibility of conventional, VRF and VRF duct type air conditioning system. The hourly and daily energy consumption of both systems were characterized based on corresponding outdoor air temperatures. Results showed that VRF air conditioning system is 15% less costly than conventional air condition. Though VRF duct system is less costly than conventional VRF, the standard rooftop height of the studied building doesn’t support VRF duct type installation. Besides the open ducting line up will not look good and creating cover for these duct will pile up the cost further. The analysis also shows that the VRF system uses 17% and 73% less energy than the rooftop System in cooling and heating seasons, respectively. The implementation of this pilot result on the National level will promote the use of sustainable energy technologies such as the VRF system.
A Low SAR In-Body Antenna for Wireless Monitoring Purpose of Pacemaker System
(Electrical Information and Communication Technology, 2019) Ahmad, Shamim; Hasan, Raja Rashidul; Hasan, Rakibul; Al Rakib, Md. Abdullah; Hasan, Md. Abid; Zubayar, Md
This research paper deals with a low SAR patch antenna that resonates at 2.415 GHz. This antenna can be employed to monitor the pacemaker system wirelessly, considering its performances. The main aim was to operate the antenna at ISM (Industrial, Scientific and Medical) band (2.4– 2.48 GHz) in the pacemaker system, where body granted materials were used to construct both the pacemaker and the antenna to ensure the biocompatibility. To investigate the antenna parameters’ changes between free space and in-side body condition, the designed antenna was examined and compared for both conditions. The key speciality of this design is that the SAR (Specific Absorption Rate), which is the most crucial parameter for any in-body antenna, was found in a considerable-safe region. Moreover, Computer Simulation Technology (CST)-based desired findings of this antenna for return loss, VSWR, and far-field radiation characteristics were found with compared to other recent body-implantable antenna related published works.
A Meandered Line Patch Antenna at Low Frequency Range for Early Stage Breast Cancer Detection
(Indonesian Journal of Electrical Engineering and Informatics (IJEEI), 2021) Al Rakib, Md Abdullah; Ahmad, Shamim; Kabir Khan, Md. Humayun; Haque, Mainul; Faruqi5, Tareq Mohammad; Jahan, Md Saroar; Mim, Jhuma Kabir
Every year a concerning number of women are affected by breast cancer which is one of the deadliest and common types of cancers. Breast cancer is curable at early stages. For detecting breast cancer, there are several methods such as MRI, Mammography, Tomography, Ultrasound, and biopsy are available in medical technology. Still, none of them are as easy and efficient as a microwave imaging technique, in this method, the antenna plays an important role. Therefore, this paper focuses on developing an antenna at a low-frequency range for microwave imaging techniques to detect cancerous tissue inside the breast. For this, the antenna parameters, i.e., return loss, VSWR, directivity, current density, and specific absorption rate were studied, by setting the antenna over without tumor and with tumor breast as upside-down, to ensure the compatibility of the antenna for the technique as well as for the patient’s body. A 5mm radius cancerous tumor was created inside the breast with dielectric conductivity of 4 and relative permittivity of 50. Cancerous cells were detected by reading the antenna parameters’ comparison between the healthy breast and the affected breast. The whole study was conducted by using CST MICROWAVE STUDIO SUITE 2020.
A Neocolonialist Take on Amitav Ghosh’s The Shadow Lines & E.M. Forster’s A Passage to India
(City University Journal, 2024-07) Islam, Tamanna
The article discusses the zealous idea of nationalism in A Passage to India and The Shadow Lines that can rewrite colonialism in a new mask. Thorough study has been done to analyze the ambivalent situations on the characters from the novels that have been through colonialism and partition. The researcher discusses the struggles of crossing the arbitrariness of borders and influence of cultural diversity in the light of the aforementioned novels from a neocolonialist view. Both of the novels depict the same aftermath of colonialism and struggle to identify themselves in the hazy idea of ‘nation’ which often ended up in homogenizing a heterogeneous community. Although, both of the novel is set in separate time zones- colonialism and after independence, the effect can be summed up from a neocolonialist perspective. That is why, infusing the idea of Edward Said´s orientalism, Fanon’s pitfalls of colonialism and Bhabha’s third space, the paper discusses how people carry the hegemonic idea of nationalism especially about the minorities in the society. The article is conducted using a qualitative research with textual analysis to support the argument of the study. It’s been found that the idea of nationalism- exclusion, othering and aggression, might create the spirit of independence but also lessens the tolerance. As a result, a neocolonial hybrid state emerges that often dehumanizes the minorities just how as some countries of the West treated the nonwhite people.
A Study of Comparing Total Population of Bangladesh with Age- Structured Linear Sharpe-Lotka Model and Malthusian Model.
(City University, 2020) Rahman, Sumaiya Bintea; Islam, Md. Shahidul; Noman, Md.Talal Bin
We consider an age-structured linear continuous population model named Sharpe-Lotka model, incorporating an factor contributes to limiting effect which may be occur due to lack of resources. This factor depends on the whole population rather than on any specific age group. In our paper, we investigate the total population size of Malthusian model and Sharpe-Lotka model for some specific age group & compare our investigated solutions with the total population of Bangladesh by using numerical method “Newton’s backward interpolation formula”.
Absurd Writing Styles: A Comparative Study on Samuel Beckett’s Waiting for Godot and Sayeed Ahmad’s The Thing
(Jahangir Nagar University Studies in Language and Literature, 2018) Rahman, M. Mahbub
This study offers an in depth analysis of the influence of Samuel Beckett on Ahmad’s works with focus on their dissimilitude as well as similitude. These two are extraordinary playwrights of Absurd Theatre; one from the West and the other from the East. So, a meticulous survey on their works unfolds trajectories of convergence. Conversely, despite the fact that Ahmad often takes his model in writing from Beckett, one can easily detect the various points of difference in their plays. Regardless of the projection of the same messages about human condition in the world, their techniques and their way of expression tend to differ in some ways. This is a narrative research that follows descriptive-cum analytical method. The textual references are given as evidence to support the argument of this study. This paper explores and shows how the Absurd plays of Beckett and those of Ahmad manage, in their own individual ways, to make us see the world differently and reflect upon our lives.
Admission Going on Fall 2023
(City University, 2023-06-01) University, City
Admission going on Fall 2023
Alienation in the Historical Perspective: The Origin and the Cause
(Ideas, 2021) Rahman, M. Mahbub
Even though the term ‘alienation is one of the most outstanding features of this era, it is not very definite what it specifically connotes. ‘Alienation’, according to the Encyclopedia Britannica is “the state of feeling estranged or separated from one’s milieu, work, products of work, or self”(Encyclopedia Britannica, 2017). Life nowadays is commonly characterized in terms of ‘alienation’. It is observed that there is almost no aspect of present-day life, which has not been discussed in terms of ‘alienation’. Sociologists use alienation in many different connections. They use the term in Sociology and Social Sciences in terms of alienation from others, from work and from society. Hegel’s and Marx’s discussions of ‘alienation’ are of considerable significance and they establish the background of a good deal of the contemporary ideas on ‘alienation’. This qualitative article, therefore, is an attempt to present a detailed analysis of ‘Alienation’ with a view to explaining this term, and how and when it appears and its connection to psychology, philosophy, sociology, Marxism, and existentialism briefly.
An Overview of Health and Environmental Threats From the Brick Kiln Industry Around the Capital of Bangladesh
(Sciences and Engineering Research, 2022-10-01) Muhib, Md. Iftakharul; Khan, Md. Shawkut Ali
Bangladesh is one of the top brick manufacturing countries in the globe. With rapid urbanization and industrialization, the brick manufacturing industry is elevating to its peak level day by day and contributing to the country’s GDP significantly. This research aims to investigate the current environmental and health threat coming from brick kilns around the capital of Bangladesh. The selected areas are Savar, Tongi, Amin Bazar and Ashulia. The methodology followed in this study was field surveying in the selected areas and information acquisitions from the secondary data. Results from this study revealed that brick kilns are highly responsible for environmental pollution that subsequently deteriorates the air quality, causes land degradation, threatens biodiversity and poses a potential impact on human health. Results also revealed that there are mainly four types of brick kilns found in selected areas e.g. Chimney Kiln (CK), Zigzag kiln (ZK), Hoffman Kiln (HK) and Hybrid Hoffman Kiln (HHK). Of these, the Fixed Chimney Kiln is found to be very obsolete at present days and creates environmental pollution at different levels. Besides these, strict implementation of the Brick Manufacturing and Brick Kilns Establishment (Control) Act, 2013 in the studied locations is still far away. This paper urges the attention of the policymakers as well as the researchers to prioritize the solution to this promising but ever-increasing pollution-causing industry of Bangladesh in sustainable ways
AN OVERVIEW OF HEALTH AND ENVIRONMENTAL THREATS FROM THE BRICK KILN INDUSTRY AROUND THE CAPITAL OF BANGLADESH
((AMERICAN INTERNATIONAL JOURNAL OF SCIENCES AND ENGINEERING RESEARCH )AIJSER, 2022) Muhib, Md. Iftakharul; Khan, Md. Shawkut Ali
Bangladesh is one of the top brick manufacturing countries in the globe. With rapid urbanization and industrialization, the brick manufacturing industry is elevating to its peak level day by day and contributing to the country’s GDP significantly. This research aims to investigate the current environmental and health threat coming from brick kilns around the capital of Bangladesh. The selected areas are Savar, Tongi, Amin Bazar and Ashulia. The methodology followed in this study was field surveying in the selected areas and information acquisitions from the secondary data. Results from this study revealed that brick kilns are highly responsible for environmental pollution that subsequently deteriorates the air quality, causes land degradation, threatens biodiversity and poses a potential impact on human health. Results also revealed that there are mainly four types of brick kilns found in selected areas e.g. Chimney Kiln (CK), Zigzag kiln (ZK), Hoffman Kiln (HK) and Hybrid Hoffman Kiln (HHK). Of these, the Fixed Chimney Kiln is found to be very obsolete at present days and creates environmental pollution at different levels. Besides these, strict implementation of the Brick Manufacturing and Brick Kilns Establishment (Control) Act, 2013 in the studied locations is still far away. This paper urges the attention of the policymakers as well as the researchers to prioritize the solution to this promising but ever-increasing pollution-causing industry of Bangladesh in sustainable ways.
ANALYSING THE BEST QUALITY PARAMETER OF DIE-CASTING PRODUCTS
(AMERICAN INTERNATIONAL JOURNAL OF SCIENCES AND ENGINEERING RESEARCH(AIJSER)(, 2022) Khan, Md. Shawkut Ali; Muhib, Md. Iftakharul
Die casting has revolutionized manufacturing technology by facilitating mass production while maintaining dimensional accuracy, stability, and strength. It has a broad array of applications in the automotive, lighting, industrial, and domestic sectors. The design parameters have a substantial impact on the quality of die castings. As a response, the aim of this research is set to look into the design characteristics of a hot chamber die-casting. The analysis was carried out using a hot chamber injection molding machine and ZAMAK 5 (Zinc: 96%, Al: 3.5%, and Cu: 0.5%) as the material. To determine the optimal quality parameters for a hot chamber die casting method, the injection speed, chilled water temperature, and cooling time were varied. The injection speeds were set to 4 ms-1, 5 ms-1, and 5 ms1, respectively, while the chiller temperatures were set at 13°C, and 18°C. In addition, cooling times of 0.8s, 1.2s, 1.6s, and 2s were also recorded. The production analysis was further investigated for casting weights of 40g, 60g, 80g, and 100g. The cooling time was set to 2 seconds, 1.6 seconds, 1.2 seconds, and 0.8 seconds. Following the collection of data, we discovered and examined the most successful and cost-effective parameters for mass production, which offer promises for the industries.
Analysis of genetic polymorphisms in somaclonal variants of strawberry by RAPD markers
(Bioscience Research, 2018) Bir, Md. Shahidul Haque; Haque, Md. Samiul; Haque, M. Mahbubul; Nath, Uzzal Kumar; Khatun, Roushan Ara; Ali, Mohammad; Soh, ,EunHee; Park, Kee Woong
The understanding of the importance of dietary berries of maintaining human health has led to unrestrained increase of global strawberry crop production. The present work was conducted for molecular characterization and selection of genetically pure somaclonal variants of strawberry. For molecular characterization, RAPD (Random Amplified Polymorphic DNA) markers namely instead OPK 01, OPK-02, and OPK-03, showed good technical resolution and sufficient variations among the somaclonal variants. A total of 29 RAPD bands were scored, of which 27 (94.87%) by using these arbitrary primers were obtained by polymorphic amplification products. OPK-01 produced the number of polymorphic bands of 100-700 bp compared to OPK-02 and OPK-03. All the somaclonal variants produced polymorphic bands with three RAPD markers suggesting that the somaclonal variants were different from each other and genetic divergence were present among them. Thus, these markers could be used for comparison of the genetic relationships, determination of patterns of genetic variation, and measurement of genetic distance among the somaclonal variants of strawberry.
Arduino Based Automatic Power Factor Control
(INTERNATIONAL JOURNAL of SMART GRID, 2021) Al Rakib, Md Abdullah; Nazmi, Sumaiya; Imam, Md Hasan; Nasir Uddin, Mohammad
- When the inductive load is brought into the industry, it is known that the power factor will drop. The electricity cost will be greater if the power factor is decreased. When the power factor drops in our system, the automated capacitor sets are activated, and the factor of power is restored with a predetermined level. The unique element of our research work is that an IoT (Internet of Things) technology was used to complete it. It will be capable to monitor and operate the research work from any place on the Internet, in addition to monitoring from the research work display. As a programming device, it has been utilized an Arduino Uno Microcontroller. The PF may be improved to increase current-carrying capacity, enhance voltage to equipment, minimize power losses, and cut electric costs. Reactive current generators are PF correction capacitors. We contribute to increasing the power factor by helping to balance the nonworking power used by inductive loads. In this article, the power factor of a load is measured using an Arduino Uno microcontroller, in which the necessary capacitors are then triggered to compensate for reactive power and put the factor of power closer near unity.
Beckett’s Godot: Not Just an Enigma
(Harvest: Jahangirnagar Studies in Language and Literature, 2011) Rahman, M.Mahbub
Waiting for Godot was a unique outburst in the literary world that changed the face of twentieth century drama. Samuel Beckett is a peculiar brand of the era. His weird ideas expounded within the framework of a few acts certainly allow him a stature quite distinct from his contemporaries whose works are expressions of their personal experiences, which Albert Camus characterized as ‘absurdity’. One might feel that Beckett has made the feelings of absurdity yet uncertain, more philosophic and therefore distinctly obscure, it is difficult to pin point and pronounce a last word. I consider Beckett’s dramatic art to be expressions of his most intimate visions on the fundamental philosophical question about the place of the human being in the surrounding world. His characters are perceived not as distinct individuals rather as grossly generalized images of all ‘mankind’who have become the slaves of an uncaring and cruel world. So, they need a Godot to give a meaning to their existence. It is true that character flaws are exaggerated and characters appear to be dull and boring yet Beckett’s characters are stereotype and they represent mankind in general. This paper analyses Beckett’s Godot not just an enigma rather it represents human life. It will also focus why there is no escape from Godot to live the human life.
Cancer Registry Importance in Bangladesh: A Review and A Mobile Application Based Solution
(City University, 2020) Akter, Sharmin; Nayeem, Md. Imtiaz
In recent times, cancer becomes the major health issue. Cancer registry is challenging but a part of modern health care that creates awareness globally. Time has come, when Bangladesh has to give supreme priority to make a smart system for cancer registration to collect and manage proper database of the number of cancer patient, survivor rate, death rate and chronic condition for future analysis. . This review has twofold goals, first is propose an effective solution through a mobile app for cancer registry and second is suggest a efficacious method for cancer registration by exploring the cancer registry methods are available in journal articles. The increasing number of smart mobile phone user is immensely helping us in this purpose. In this paper two types of methods are used for cancer registry, one is community clinic based registry approach another is hospital based registry approach. Community clinic is the unique innovation in Bangladesh health care system, and this community clinic based cancer registry is first time going to be implemented through this paper. Base on reviewing the features of apps and surveying on 100 of people including doctors, cancer patients and CHCP, we become able to propose an app of cancer registry. Apps were collected from August 2018 to March 2019 and data was analyzed in April 2019.
CIVIL SOCIETY IN A WEAK STATE: THE CASE OF BANGLADESH, 1971-2006
(Kulliyyah of Islamic Revealed Knowledge and Human Sciences International Islamic University Malaysia, 2009-02) Kabir, Kazi Shahdat
The study examines the role of civil society in a weak state that is Bangladesh. Data has been collected from two main sources namely documents and interviews. This study assumes that firstly the type, nature and the distribution of power in the state determines the relationship between state and the civil society; secondly, civil society groups tend to take over the key functions of the state and emboldened by their success, the civil society groups, tend to deviate from their traditional activities and get involved in business and political activities; thirdly, that strong civil society groups in a weak state become intolerant towards their fellow groups, social values and the state and finally, challenged by increasing civil society activities, the state undertakes steps to regain control over the civil society. However, this research has examined the involvement of the Non-Governmental Organisations (NGOs in Bangladesh. Larry Diamond and Edward Shills have agreed that the civil society organisations are distinct from other groups in the society at least in four basic respect which are: concern with public ends, voluntary and non-profit making, non-political and civil and tolerant. Two main NGOs in Bangladesh, Bangladesh Rural Advancement Committee (BRAC) and Proshika Manabik Unnyan Kendra [Proshika Human Development Centre] are the focus of the study. The study has found that the NGOs claiming to be part of civil society organisations do not exhibit all the above four characteristics. Although NGOs work for public ends they go against the other indicators such as voluntary, non-profit making, non-political, civility and tolerance. Throughout the history of Bangladesh, the State has shown some reactions whenever the NGOs have gone beyond the traditional civil society concept.