622 research outputs found
Preface
No full textAzad, M ORCiD: 0000-0001-8258-6057; Rasul, M ORCiD: 0000-0001-8159-1321In recent years, the transport sector is facing many challenges in meeting the growing liquid fuel demand in an energy efficient and environmentally sustainable manner. Advanced Biofuels: Applications, Technologies, and Environmental Sustainability provides the industries and the academia with recent development in technologies and application of biofuels in the field of the internal combustion engine, more specifically in diesel engine. The book primarily focuses on low emissions and alternative transport fuels; energy efficient diesel engine; and biofuels technologies, applications, and environmental sustainability to academics, researchers, practicing engineers, technologists, and students. It is a valuable resource to undergraduate, honours, and postgraduate research students in the field of biofuel applications in advanced level
Recent trends and challenges of algal biofuel conversion technologies
No full textAzad, M ORCiD: 0000-0001-8258-6057The rapid growth in global energy demands has triggered the scientific community to explore new stepwise biofuel conversion approaches. Biofuels are considered as one of the most promising renewable alternatives to meet the global energy crisis and environmental concerns. Microalgae biomass has proven the potentiality for the production of biofuels, chemicals, and bio-based products leading to the transition from petroleum-based economy to a bio-based economy. Algal biofuel offers a number of advantages, for example, higher growth rate with no competition with food and minimal or no environmental impacts. Biofuel produced from microalgae has low viscosity and low density with high caloric value compared to cellulosic biofuel, which makes algal biofuel more suitable for the application. This chapter outlines the progress on the biofuels production from algal biomass. The process description of possible algal biofuel routes underlining the challenges associated with large-scale production have been detailed in this chapter
Modeling bank efficiency in Malaysia: An adaptive network data envelopment analysis approach / Md. Abul Kalam Azad
No full textThis study proposes an adaptive Network Data Envelopment Analysis (NDEA) technique, which examines efficiency of all 43 commercial banks operating in Malaysia by utilizing the three traditional bank efficiency measurement approaches (intermediation, production and profitability). From past studies, separate bank efficiency measurement approaches have proven to produce biased results. For instance, when bank efficiency is measured solely based on its profitability, banks’ long-term sustainability (capital ratio) could be ignored and affect the bank’s profitable status. This study also proposes CAMELS (Capital adequacy, Assets, Management-capability, Earnings, Liquidity, Sensitivity) rating in selecting the variables to measure bank efficiency by explaining how the variables are linked to each other. This has not been done in any previous studies. The contributions of this study are three-fold. This study explains how the traditional ‘black-box’ of input-output has failed to probe into the bank’s true efficiency. Secondly, by using the proposed model, the study empirically contributes in providing a better comparative efficiency measurement platform in Malaysian context. Thirdly, this study addresses the existence of undesirable bank output (i.e., bad debts) in determining bank efficiency. Findings of this study suggest that efficiency scores vary with respect to variable and approach selection. When considering the effect of business cycles, profitability approach is recommended. Whereas, intermediation approach should be more suitable in examining the bank performance with large time series data because it lies on the “going concern” accounting concept. This measure of bank performance refers to the ability of a bank to convert deposits into loans. Lastly, the production approach would give a holistic idea on the banks’ ability to serve the economy. In order to measure bank efficiency more accurately, it is also important to consider the undesirable outputs generated from banking operations. Past research stated that benchmarking of banks based only on net income could lead to bankruptcy even if that bank had high efficiency score. Lastly, the empirical findings of this study reveal that foreign Islamic banks are pioneer in all three nodes in the proposed NDEA model. These results signify an advanced capacity of foreign banks in risk mitigation, investment portfolio and liquidity management. In the context of Malaysian’s current bank regulations, with existing discriminations and government restrictions on foreign bank ownership, these results reveal that even in a favorable business condition, the Malaysian local conventional banks have not been performing well
Investigation on the effect of butanol isomers with gasoline on spark ignition engine characteristics
No full textAzad, M ORCiD: 0000-0001-8258-6057This chapter aims to explore the performance and emission characteristics of butanol isomers in order to suggest technical improvisations for their adoption as a commercial fuel in spark ignition engines. The limited availability of research works using butanol isomer blends motivates the current work involving an extensive investigation of the alternative fuels as a comparative study. Through extensive evaluation of the prevailing research works, it is found that by substituting pure gasoline fuel with butanol-gasoline blends, an increase in the carbon monoxide and hydrocarbon emissions due to the lower calorific value and higher latent heat of vaporization of butanol fuel can be obtained. However, oxides of nitrogen emissions are found to decrease with reference to that of pure gasoline fuel. The current study is extended to validate the results obtained from a review study by conducting an experimental investigation on an SI engine fueled with n-butanol-gasoline blend and isobutanol-gasoline blend. The concentrations of butanol isomers in the blends are varied from 10% to 30%, and the obtained performance and emission characteristics are compared to that of pure gasoline fuel. It is observed that the experimentally obtained characteristics are in accordance with the results obtained through comparative evaluation
Investigation of diesel engine in cylinder flow phenomena using CFD cold flow simulation
No full textAzad, M ORCiD: 0000-0001-8258-6057This chapter investigates the computational fluid dynamic (CFD) simulation of diesel engine cold flow behavior at the speed of 2400 rpm. In this investigation, a three-dimensional (3D) combustion chamber model with an inlet and exhaust port was developed using the numerical tool. The dynamic meshing was done for different piston positions, inlet, and outlet valves operation for the entire range of the engine cycle (0°–720° crank angle (CA)). The standard k-ε turbulence model was used for CFD analysis to observe velocity, pressure, and temperature distribution. The entire process is highly complex, which requires more computational time with the powerful machine. The numerical simulation was carried out using a high-performance computing (HPC) system with 16 parallel cores and a 100 GB memory machine. The result shows the outstanding in-cylinder flow behavior, velocity, temperature, pressure, and turbulent kinetic energy for the diesel engines. The outcome of this study will be helpful to the engine designers for designing a fuel-efficient engine combustion chamber with minimum emission
Advancement in remote sensing of wind energy
No full textAzad, M ORCiD: 0000-0001-8258-6057In modern applications, wind turbines are gaining in height and becoming larger in size, as well as being installed in complex, mountainous, and hilly terrain to produce large amounts of energy for neighboring populations and industries. However, one must keep in mind that the efficiency of a wind farm is greatly affected by inaccurate wind resource assessment. Therefore, it is necessary to investigate wind resource potential to estimate how much energy is available at the site and how much power the wind turbine can produce, because the power output of a wind turbine scales cubically with the available wind speed. In this case, to achieve the highest possible efficiency from a wind farm and to install modern machines of even larger heights, it becomes necessary to study and precisely estimate wind resource potential and its economic feasibility. The investigation of wind resource at larger heights and at complex wind farms requires a more physical volume-based measurement. Ground-based remote-sensing techniques such as light detection and ranging and sound detection and ranging are becoming increasingly useful and popular in the wind energy sector for resource assessment as they help in reducing complexity, uncertainty, and technicality in modern wind farm development, because they provide volume measurement and measure the entire rotor field from top to bottom at each height, particularly at higher hub height, which is difficult to do using conventional techniques, traditional techniques, or meteorological mast techniques. The meteorological mast consists of a cup anemometer and other measuring instruments to measure wind speed and wind direction. Using meteorological mast is not a representative idea as it gives point and fixed measurements, and empirical equations such as power law and log law are used to convert wind speed measured at 10 m or 30 m to larger heights of 100 m, 120 m, or more. This chapter is focused on increasing confidence in the result of remote-sensing measurement. Most importantly, there is economic merit in determining the total amount of cash flowing on wind resource assessment using advance different techniques
Introduction to sustainable and alternative ecofuels
No full textAzad, M ORCiD: 0000-0001-8258-6057; Rasul, M ORCiD: 0000-0001-8159-1321This book will help readers develop a deeper understanding of the relevant concepts and solutions to global sustainability issues with the goal of achieving cleaner, more efficient energy
Evaluation of Musculoskeletal Disorders, Comorbidities, and Quality of Life among the Elderly Population in Bangladesh
No full textBackground: Musculoskeletal (MSK) disorders are a leading cause of disability among the elderly worldwide, significantly impacting their quality of life. In Bangladesh, the ageing population is expanding rapidly, yet data regarding the burden of MSK conditions and their effects on functional ability and wellbeing remain scarce.
Objective: This study aimed to evaluate the prevalence of musculoskeletal disorders, associated comorbidities, and quality of life among elderly individuals in Bangladesh.
Methods: A cross-sectional study was conducted at the Department of Physical Medicine & Rehabilitation, Bangladesh Medical University, from July 2021 to June 2022. A total of 103 adults aged 60 years and above with diagnosed MSK conditions were recruited via convenience sampling. Data were collected through structured interviews assessing demographic characteristics, MSK disorders, activities of daily living (ADL), and quality of life measured by the WHOQOL-BREF. Diagnoses were based on established clinical criteria. Statistical analyses were performed using SPSS version 26, including descriptive statistics, chi-square tests, and univariate logistic regression.
Results: The majority of participants were aged 60–65 years (61.2%) and resided in urban areas (72.8%). Knee pain (84.5%) and back pain (78.6%) were the most prevalent MSK conditions. No significant differences were observed in MSK disorder prevalence between males and females. Increasing numbers of comorbidities were associated with higher mean ADL scores, indicating greater functional impairment. Strong positive correlations were found among different ADL scales, while negative correlations existed between ADL measures and all quality of life domains. The physical and environmental domains of quality of life showed the strongest interrelations.
Conclusion: MSK disorders and comorbidities substantially affect the functional capacity and quality of life among the elderly in Bangladesh. These findings highlight the need for integrated healthcare strategies to address the complex health challenges faced by this vulnerable population
A study on standard n-ideal of a lattice
No full textThis thesis is submitted to the Department of Mathematics, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Mathematics, April 2019.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 49-50).Lattice theory is an important part of mathematics . Ideal lattice and n-ideal of a lattice have
played many roles in development of lattice theory. Historically, lattice theory started with
Boolean distributive lattices: as a result, the theory of ideal lattice and n-ideal of a lattice is
the most extensive and most satisfying chapter in the history of lattice theory. Ideal lattice
have provided the motivation for many results, in general lattice theory. Many conditions on
lattices and on element and ideals of lattices are weakened forms of distributivity is imposed
on lattices arising in various areas of mathematics, especially algebra.
In lattice theory there are different classes of lattices known as variety of lattices. Class of
Boolean lattice is of course most powerful variety. Throughout this thesis we will be
concerned with another large variety known as the class of ideal lattice and n-ideal of a lattice
have been studied by several authors.
The realization of special role of ideal lattices moved to break with the traditional approach to
lattice theory, which proceeds from partially ordered sets to general lattices, semi modular
lattices, modular lattices and finally ideal lattices.
In this thesis we give several result on ideal and n-ideal which will certainly extend and
generalize many results in lattice theory. In order to review, we include definations, examples,
solved problems and proof of some theorems. The thesis contains four chapter.
Chapter 1 we have discussed the basic defination of relation, poset, lattice, complete
lattice, convex sub lattice, complemented and relatively complemented lattice. We also proved
that, Dual of a complete lattice is complete .
Chapter 2 have discussed basic concept of ideal and n-ideal of lattice. Here we study the
defination and examples of ideal and n-ideal. Some imprtant theorem like “If n is a neutral
element of a lattice, then I (L) n is modular if and only if L is modular”.
Chapter 3 we have discussed Standard element and n-ideals. We also discussed in this
chapter Congruence relation.
Chapter 4 deals with standard n-ideal and Principal n-ideal. This is the main part of this
thesis work. In this chapter we have discussed some defination and some important theorems
like “For a neutral element n and a standard n-ideal S and an n-ideal I, S I is also a
standard n-ideal” .Md Imran HossenMaster of Science in Mathematic
Study of Principal n-ideals of a Lattice
No full textThis thesis is submitted to the Department of Mathematics, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Mathematics, July 2006.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 127-131).This thesis studies extensively the Principal n-ideals of a lattice. The idea of n-ideals in a lattice was first introduced by Cornish and Noor in studying the kernels around a particular element n, of a skeletal congruence on a distributive lattice. Then Latif and Ayub Ali in their thesis studied thoroughly on the n-ideals and established many valuable results. For a fixed element n of a lattice L, a convex sublattice of L containing n is called an n-ideal. If L has a "0", then replacing n by 0, an n-ideal becomes an ideal and if L has a "1" then it becomes a filter by replacing n by I. Thus, the idea of n-ideals is a kind of generalization of both ideals and filters of lattices. The n-ideal generated by a finite number of elements of a lattice is called a finitely generated n-ideal, while the n-ideal generated by a single element is known as a principal n-ideal. Latif in his thesis has given a neat description on finitely generated n-ideals of a lattice and has provided a number of important results on them. For a lattice L, the lattice of all n-ideals of L and the lattice of all finitely generated n-ideals of L are denoted by In (L) and Fn (L) respectively, while Pn (L) represents the set of principal n-ideals of L. In this thesis, we devote ourselves in studying several properties on Pn (L) and Fn (L) which will certainly enrich many branches of lattice theory. Our results in this thesis generalize many results on normal, relatively normal, m-normal and relatively m-normal lattices. We also introduce the concept of n-annulets and α -n-ideal in studying Pn (L).
In this connection it should be mentioned that if L has a 0, then putting n = 0 we find that Fn (L) is the set of all principal ideals of L which is isomorphic to L. Thus, for every result on Fn (L) in this thesis, we can obtain a result for the lattice L with 0 by substituting n = 0. Hence the result in each chapter of the thesis regarding Fn (L) are generalizations of the corresponding results in lattice theory.
In chapter 2, we discuss some fundamental properties of n-ideals, which are basic to this thesis. Here we give an explicit description of Fn (L) and Pn (L) which are essential for the development of the thesis. Though Fn (L) is always a lattice, Pn (L) is not even a semilattice. But when n is a neutral element, Pn (L) becomes a meet semilattice. Moreover, we show that Pn (L) is a lattice if and only if n is a central element, and then in fact, Pn (L) = Fn (L). We also show that, for a neutral element n, the lattice L is complemented if and only if Pn (L) is so. In this chapter we also discuss on prime n-ideals. We give several properties and characterizations of prime n-ideals. We include a proof of the generalization of Stone's separation theorem. We also include a new proof of the result that for a distributive lattice L, Fn (L) is generalized Boolean if and only if prime n-ideals are unorderd.
Chapter 3 discusses on minimal prime n-ideals of a lattice. We give some characterizations on minimal prime n-ideals which are essential for the further development of this chapter. Here we provide a number of results which are generalizations of the results on normal lattices.
We prove that for a distributive lattice L, Fn (L) is normal if and only if each prime n-ideal of L contains a unique minimal prime n-ideal. We also show that if n is central in L, then Pn (L) is a normal lattice if and only if any two minimal prime n-ideal are comaximal which is also equivalent to n ∩ n = {n} implies n* v n*=L.
In chapter 4 we introduce the notion of relative n-annihilators n. We characterize distributive and modular lattices in terms of relative n-annihilators. Then we generalize several results of Mandelker on annihiltors. We use these to characterize those Fn (L) which are relatively normal lattices. Among many results we have shown that for a central element n, Pn (L) is a relatively normal lattice, if and only if any two incomparable prime n-ideal are comaximal . What is more, this is also equivalent to the condition n,n> v n,n> = L for all a,b ϵL.
Pseudocomplemented distributive lattices satisfying Lee's identities form equational subclasses denoted by Bm , - 1 ≤ m ˂ w Cornish have studied distributive lattices analogues to Bm-lattices and relatively Bm-lattices. He referred then as m-normal lattices.Moreover, Beazer and Deavy have each independently obtained several characterizations of (sectionally) Bm -lattices and relatively Bm -lattices.
In chapter 5 we generalize their results by studying finitely generated n-ideals which form a m-normal and a relatively m-normal lattice .We show that for a central element n ϵ L, Pn(L) is m-normal if and only if for any m+1 distinct minimal prime n-ideals P0 ............., Pn of L, P0 v ................v Pm = L. In this chapter we also show that for a central element n ϵ L, Pn (L) is relatively m-normal if and only if any m+1 pairwise incomparable prime n-ideals are comaximal.
Chapter 6 introduces the concept of n-annulets and α -n-ideals of a lattice. Here we include several result on the set of n-annulets An(L) when n is a central element of L. We proved An(L) is relatively complemented if and only if Pn(L) is sectionally quasi-complemented.Md. Abul Kalam AzadDoctor of Philosophy in Mathematic
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