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Journal of Analytical Sciences, Methods and Instrumentation 2013年第3期3卷 24-29页

作者： md. Nazmul hasan M. Akhtaruzzaman md. Zakir Sultan Centre for Advanced Research in Sciences Uni- versity of Dhaka Dhaka Bangladesh Institute of Nutrition and Food Science University of Dhaka Dhaka Bangladesh

The current experiment was conducted for the simultaneous determination of several water-soluble vitamins like ribo- flavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5) and pyridoxine (vitamin B6) in five highly con- sumed local leafy vegetables named as bottle gourd leaves (Lagenaria vulgaris) (local name Lau shak), green amaranth leaves (Amaranthus viridis) (local name Data shak), red amaranth leaves (Amaranthus gangeticuss) (local name Lal shak), Indian spinach (Basella alba) (local name Pui shak) and bitter gourd leaves (Momordica charantia) (local name Korola shak). The analyses were performed by HPLC using an analytical reversed phase C-18 (ODS column, 250 × 4.6 mm, 5 μm, Phenomenex, Inc.) column with the mobile phase consisting of a mixture of buffer (hexane sulphonic acid sodium, potassium dihydrogen phosphate and triethylamine, pH 3.0) and methanol in the ratio of 96:4 (v/v) at a flow rate of 1 mL/min with UV detection at 210 nm. The retention times for the vitamins were obtained as 3.61 min, 6.37 min, 9.51 min and 11.51 min for Vitamins B2, B3, B5 and B6, respectively. These obtained values of the vitamins were compared with the values available in published literatures of Deshio Khaddar Pustiman (DKPM), Indian food value (IFV) and United States Department of Agriculture (USDA).

关键词： HPLC Analysis Vitamin B2 Vitamin B3 Vitamin B5 Vitamin B6 Leafy Vegetables

Numerical Analysis and Design of Photonic Crystal Fiber Based Surface Plasmon Resonance Biosensor

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Journal of Sensor Technology 2019年第2期9卷 27-34页

作者： md. Biplob Hossain md. Sanwar Hossain md. Moznuzzaman md. Amzad Hossain md. Tariquzzaman md. Tanvir hasan md. Masud Rana Department of Electrical and Electronic Engineering Jashore University of Science and Technology Jashore Bangladesh Department of Electrical and Electronic Engineering Jashore University of Science and Technology Jashore BangladeshMd. Amzad Department of Electrical and Electronic Engineering Bangladesh University of Business and Technology Dhaka Bangladesh Department of Electrical and Electronic Engineering Rajshahi University of Engineering & Technology Rajshahi Bangladesh.

In this paper, a high sensitive photonic crystal fiber (PCF) based surface plasmon resonance (SPR) biosensor is numerically studied. In this structure, as a plasmonic material, gold (Au) is used because of its chemical activeness. And a layer of sensing medium is used outside of the fiber to make the structure effective. Any unknown biomolecular analyte can be detected by placing or flowing it on the metal surface. Guiding properties and results are investigated using Finite element method (FEM). Results show that maximum sensitivity is 4000 nm/RIU, as well as resolution, is 2.5 × 10−5 RIU of the proposed sensor.

关键词： Biosensor PCF SPR SPP Mode Sensitivity

Insights into the physical properties and anisotropic nature of ErPdBi with an appearance of low minimum thermal conductivity

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Chinese Physics B 2021年第1期30卷 398-406页

作者： S K Mitro R Majumd.r K M Hossain md.Zahid hasan md.Emran Hossain M A Hadi Bangamata Sheikh Fojilatunnesa Mujib Science and Technology University Jamalpur-2012Bangladesh Physics Discipline Khulna UniversityKhulna-9208Bangladesh Department of Materials Science and Engineering University of RajshahiRajshahi-6205Bangladesh Department of Electrical and Electronic Engineering International Islamic University ChittagongKumiraChittagong-4318Bangladesh Department of Physics University of RajshahiRajshahi6205Bangladesh

We theoretically study the structural, elastic and optical properties of Er Pd Bi together with its anisotropic behaviors using density functional theory. It is observed that Er Pd Bi satisfies the Born stability criteria nicely and possesses high quality of machinability. The anisotropic behavior of Er Pd Bi is reported with the help of theoretical anisotropy indices incorporating 3 D graphical presentation, which suggests that Er Pd Bi is highly anisotropic in nature. It is noticed that the minimum thermal conductivity is very low for Er Pd Bi compared to the several species. This low value of minimum thermal conductivity introduces the potentiality of Er Pd Bi in high-temperature applications such as thermal barrier *** addition, deep optical insights of Er Pd Bi reveal that our material can be used in different optoelectronic and electronic device applications ranging from organic light-emitting diodes, solar panel efficiency, waveguides etc. to integration of integrated circuits. Therefore, we believe that our results will provide a new insight into high-temperature applications and will benefit for the development of promising optoelectric devices as well.

关键词： Er Pd Bi minimum thermal conductivity anisotropy density functional theory(DFT)

Finite Element Analysis of Tubular KK Joint under Compressive Loading

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American Journal of Computational Mathematics 2024年第3期14卷 291-304页

作者： Mohammad Tanzil hasan md. Jobayer Mia md. Syful Isalm Bipul Department of Mathematics Bangabandhu Sheikh Mujibur Rahman Maritime University Dhaka Bangladesh Department of Naval Architecture and Offshore Engineering Bangabandhu Sheikh Mujibur Rahman Maritime University Dhaka Bangladesh

KK tubular joints are used to build jacket-type offshore structures. These joints are mostly made up of structural steel. These joints can withstand yield, buckling, and lateral loads depending on the structure’s design and environment. In this study, the Finite Element Model of the KK-type tubular joint has been created, and analysis has been performed under static loading using the Static Structural analysis system of ANSYS 19.2 commercial software and structural mechanics module of COMSOL Multiphysics. The KK tubular model is analyzed under compressive load conditions, and the resulting stress, strain, and deformation values are tabulated in both graphical and tabular form. This study includes a comparison of the outcomes from both commercial software. The results highlight that maximum stress, strain, and deformation values decrease as joint thickness increases. This study holds significant relevance in advancing the understanding of tubular KK joints and their response to compressive loading. The insights derived from the analysis have the potential to contribute to the development of more robust and reliable tubular KK joints in various engineering and structural applications. .

关键词： KK Joint Brace Offshore Structures Chord Numerical Analysis Static Analysis

A Numerical Simulation of Air Flow in the Human Respiratory System Based on Lung Model

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Journal of Applied Mathematics and Physics 2023年第8期11卷 2205-2215页

作者： md. Kamrul hasan Mahtab U. Ahmmed md. Samsul Arefin Department of Mathematics Khulna University of Engineering and Technology Khulna Bangladesh Department of Mathematics Jahangirnagar University Dhaka Bangladesh

The lung is an important organ that takes part in the gas exchange process. In the study of gas transport and exchange in the human respiratory system, the complicated process of advection and diffusion (AD) in airways of human lungs is considered. The basis of a lumped parameter model or a transport equation is modeled during the inspiration process, when oxygen enters into the human lung channel. The quantitative measurements of oxygen are detached and the model equation is solved numerically by explicit finite difference schemes. Numerical simulations were made for natural breathing conditions or normal breathing conditions. The respiratory flow results for the resting conditions are found strongly dependent on the AD effect with some contribution of the unsteadiness effect. The contour of the flow rate region is labeled and AD effects are compared with the variation of small intervals of time for a constant velocity when breathing is interrupted for a negligible moment.

关键词： Lumped Model Lumped Model Channel Mass Flow Rate Ideal Law of Gas 2D Advection Diffusion Equation Finite Difference Scheme

Preparation and Investigation of Mechanical and Physical Properties of Flax/Glass Fabric Reinforced Polymer Hybrid Composites

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Journal of Flow Control, Measurement & Visualization 2023年第3期11卷 165-182页

作者： Sayed hasan Mahmud md. Washim Akram md. Fuad Ahmed md. Atik Bin Habib Department of Textile Engineering National Institute of Textile Engineering & Research Dhaka Bangladesh Department of Fashion Design & Apparel Engineering National Institute of Textile Engineering & Research Dhaka Bangladesh Department of Textile Fashion and Design R. P. Shaha University Narayangaj Bangladesh

Synthetic reinforced composites affect the environment adversely and have become a global concern, causing increased natural composite demand for sustainability and cost effectiveness. Glass is a popular material that is highly consumed in reinforced composites for its superior mechanical strength. As opposed to that, flax obtained from flax stalks can be used as an alternative reinforcing material with synthetic fibers to minimize manmade fiber consumption. Hence, this research work addresses a few flax/glass-reinforced hybrid composites by using a thermoset polyester matrix. Here, six categories of samples are made, like neat flax, neat glass, and flax/glass fabric reinforced hybrid composite, followed by different stacking layer sequences and hand layout techniques during processing. Afterwards, the mechanical behavior, thermal stability, morphological behavior, and water absorption of hybrid samples were investigated. Among the developed samples, neat glass (NG) composite exhibits superior mechanical properties, while neat flax (NF) shows the lowest result. It is apparent that the mechanical properties and thermal stability of hybrid samples are in between NF and NG because, by adding glass with flax fabric, the strength of hybrid samples is increased. Moreover, it is noticeable that, due to multiple stacking layers of flax and glass, hybrid 3 and hybrid 4 show better strength than consecutive single stacking layers in hybrid 1 and hybrid 2. Among all hybrid composites, the H4 shows comparatively better mechanical and thermal properties due to having the glass layers on the outermost surface. In summary, this research work demonstrated the feasibility of flax fabric with glass fabric as a reinforced hybrid composite that can be used in automobile inner bodies, household furnishing, and home interior decoration.

关键词： Flax-Glass Fabric Reinforced Composites Mechanical Properties SEM TGA Polyester Resin

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Secure Wireless Multicasting through Nakagami-m Fading Channels with Multi-Hop Relaying

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Journal of Computer and Communications 2023年第5期11卷 177-193页

作者： md. Mizanur Rahman md. Zahurul Islam Sarkar Mohammad Mahmud hasan Department of Electrical and Electronic Engineering RUET Rajshahi Bangladesh

The additional diversity gain provided by the relays improves the secrecy capacity of communications system significantly. The multiple hops in the relaying system is an important technique to improve this diversity gain. The development of an analytical mathematical model of ensuring security in multicasting through fading channels incorporating this benefit of multi-hop relaying is still an open problem. Motivated by this issue, this paper considers a secure wireless multicasting scenario employing multi-hop relaying technique over frequency selective Nakagami-m fading channel and develops an analytical mathematical model to ensure the security against multiple eavesdroppers. This mathematical model has been developed based on the closed-form analytical expressions of the probability of non-zero secrecy multicast capacity (PNSMC) and the secure outage probability for multicasting (SOPM) to ensure the security in the presence of multiple eavesdroppers. Moreover, the effects of the fading parameter of multicast channel, the number of hops and eavesdropper are investigated. The results show that the security in multicasting through Nakagami-m fading channel with multi-hop relaying system is more sensitive to the number of hops and eavesdroppers. The fading of multicast channel helps to improve the secrecy multicast capacity and is not the enemy of security in multicasting.

关键词： Frequency Selective Fading Multi-Hop Relaying Probability of Non-Zero Secrecy Multicast Capacity Secure Outage Probability for Multicasting

Adequate Closed Form Wave Solutions to the Generalized KdV Equation in Mathematical Physics

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Journal of Applied Mathematics and Physics 2024年第6期12卷 2069-2082页

作者： md. Munnu Miah md. Al Amin Meia md. Matiur Rahman Sarker Ahammodullah hasan Department of Mathematics Islamic University Kushtia Bangladesh Department of Mathematics Government Titumir College Dhaka Bangladesh Department of Pharmacy University of Asia Pacific Dhaka Bangladesh

In this paper, we consider the generalized Korteweg-de-Vries (KdV) equations which are remarkable models of the water waves mechanics, the shallow water waves, the quantum mechanics, the ion acoustic waves in plasma, the electro-hydro-dynamical model for local electric field, signal processing waves through optical fibers, etc. We determine the useful and further general exact traveling wave solutions of the above mentioned NLDEs by applying the exp(−τ(ξ))-expansion method by aid of traveling wave transformations. Furthermore, we explain the physical significance of the obtained solutions of its definite values of the involved parameters with graphic representations in order to know the physical phenomena. Finally, we show that the exp(−τ(ξ))-expansion method is convenient, powerful, straightforward and provide more general solutions and can be helping to examine vast amount of travelling wave solutions to the other different kinds of NLDEs.

关键词： The Generalized KdV Equation The exp(-τ(ξ)) -Expansion Method Travelling Wave Solitary Wave

Predictive car-following scheme for improving traffic flows on urban road networks

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Control Theory and Technology 2019年第4期17卷 325-334页

作者： A.S.M.BAKIBILLAH Mahmudul hasan md.Mustafijur RAHMAN md.Abdus Samad KAMAL School of Engineering Monash UniversityBandar SunwaySelangorMalaysia Technology Operations Department Grameenphone Ltd.DhakaBangladesh Department of Electrical and Electronic Engineering Manarat International UniversityDhakaBangladesh Division of Mechanical Science and Technology Graduate School of Science and TechnologyGunma UniversityJapan

Driving behavior is one of the main reasons that causes bottleneck on the freeway or restricts the capacity of signalized *** paper proposes a car-following scheme in a model predictive control(MPC)framework to improve the traffic flow behavior,particularly in stopping and speeding up of individual vehicles in dense urban traffic under a connected vehicle(CV)*** information received through vehicle-to-vehicle(V2V)communication,the scheme predicts the future states of the preceding vehicle and computes the control input by solving a constrained optimization problem considering a finite future *** objective function is to minimize the weighted costs due to speed deviation,control input,and unsafe *** scheme shares the planned driving information with the following vehicles so that they can make better cooperative driving *** proposed car-following scheme is simulated in a typical driving scenario with multiple vehicles in dense traffic that has to stop at red signals in multiple *** speeding up or queue clearing and stopping characteristics of the traffic using the proposed scheme is compared with the existing car-following scheme through numerical simulation.

关键词： Car-following scheme model predictive control vehicle string connected vehicle environment distributed control

Dynamic Hand Gesture-Based Person Identification Using Leap Motion and Machine Learning Approaches

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Computers, Materials & Continua 2024年第4期79卷 1205-1222页

作者： Jungpil Shin md.Almehedi hasan md.Maniruzzaman Taiki Watanabe Issei Jozume School of Computer Science and Engineering The University of AizuAizuwakamatsuFukushima965-8580Japan Department of Computer Science&Engineering Rajshahi University of Engineering&TechnologyRajshahi6204Bangladesh

Person identification is one of the most vital tasks for network security. People are more concerned about theirsecurity due to traditional passwords becoming weaker or leaking in various attacks. In recent decades, fingerprintsand faces have been widely used for person identification, which has the risk of information leakage as a resultof reproducing fingers or faces by taking a snapshot. Recently, people have focused on creating an identifiablepattern, which will not be reproducible falsely by capturing psychological and behavioral information of a personusing vision and sensor-based techniques. In existing studies, most of the researchers used very complex patternsin this direction, which need special training and attention to remember the patterns and failed to capturethe psychological and behavioral information of a person properly. To overcome these problems, this researchdevised a novel dynamic hand gesture-based person identification system using a Leap Motion sensor. Thisstudy developed two hand gesture-based pattern datasets for performing the experiments, which contained morethan 500 samples, collected from 25 subjects. Various static and dynamic features were extracted from the handgeometry. Randomforest was used to measure feature importance using the Gini Index. Finally, the support vectormachinewas implemented for person identification and evaluate its performance using identification accuracy. Theexperimental results showed that the proposed system produced an identification accuracy of 99.8% for arbitraryhand gesture-based patterns and 99.6% for the same dynamic hand gesture-based patterns. This result indicatedthat the proposed system can be used for person identification in the field of security.

关键词： Person identification leap motion hand gesture random forest support vector machine