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Observations on bud burst phenology in a field trial established with Poplar (Populus spp.)

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Forestry Studies in China 2012年第4期14卷 251-259页

作者： md. Salim AZAD Forestry and Wood Technology Discipline Khulna University Faculty of Forest Science and Forest Ecology Georg-August-University

Bud flushing is very important for the survival and growth of trees, a phenomenon matched each year with the annual course of temperature and the timing of bud flushing in the spring. Essentially it represents a serious ecological and evolutionary tradeoff between survival and growth. The most suitable timing of bud burst permits trees to begin growth sufficiently early to take advantage of favorable spring conditions, but late enough to decrease the risks of tissue damage from late frost. In the present study bud burst spring phenology of poplar （Populus tremula and P. tremuloides） from eight different provenances, originating from Eu- rope and the USA, was observed during March and April, 2009. The experimental plot was located at Solling, Germany （51~44＇0＂ N, 9036＇0＇＇ E）. A six stage subjective scoring system of bud burst phenology was used to identify the phenological stages of the seed- lings, where each plant was observed twice a week. The aim of the study was to predict phenotypic variation in poplar, originating from regions between 42~ and 60~ N latitude, growing in similar environments. Timing of bud flushing of poplar was recorded. It was found that seedlings of provenance 3, which originated from 42.35~ N latitude, started and completed flushing significantly earlier than those of other provenances, while seedlings of provenance 5, originating from 54.29~ N latitude, started flushing very late and only a few plants reached top scoring at the end of the experimental period. Analysis of variance showed statistically highly signifi- cant differences （p 〈 0.05） in bud flushing among the provenances. The correlation between scoring and flushing periods was very strong within provenances although the flushing pattern differed among provenances （origin of the planted seedlings）. Bud flushing showed a negative correlation with the origin of the planted seedlings. Given the field experience gained with this experiment, it is recommended that seedlings from proven

关键词： bud flushing dormancy genetic variation phenotype Populus tremula Populus tremuloides

Adsorption of Anionic and Cationic Dyes from Textile Effluents by Activated Carbon Prepared from Sawdust and Fish Scale

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Advances in Chemical Engineering and Science 2023年第3期13卷 189-202页

作者： Rumana A. Jahan md. mahedi Hassan Ashequl Alam Rana Mohammad Mainul Karim Centre for Advanced Research in Sciences University of Dhaka Dhaka Bangladesh Department of Applied Chemistry and Chemical Engineering University of Dhaka Dhaka Bangladesh

In Bangladesh, there are thousands of textile-dying industries spread across the country’s many regions, the majority of which involve knitting and dying. The dyeing industry uses an enormous quantity of water, as well as colors and chemicals. After the dying process has been completed, they also release a significant amount of wastewater. Cotton, wool, and polyester fiber are typically dyed with textile dyes such as reactive, acid, and disperse dyes. These dyes are utilized most frequently in the respective sectors. The dyes’ colorants are extremely poisonous and dangerous to all forms of life, including aquatic life and living things. The present work has been intended to investigate whether or not it is practicable to remove commonly used textile dyes simultaneously from an aqueous dye solution using an adsorption technique that makes use of a variety of different adsorbents. This study focuses on the removal of color from two distinct types of dyes—Methylene Blue and Reactive Blue-250 which are cationic and anionic in nature respectively, using two different types of activated carbon adsorbents prepared from sawdust and fish scale. Dye removal capacity was tested as a function of contact time, the dosage of the adsorbent, pH during the treatment process, temperature and initial concentration of dye. The applicability of the Langmuir and Freundlich adsorption isotherms in describing experimental data was investigated. The micro and mesoporous activated carbon prepared from sawdust and fish scale identified by Scanning Electron Microscopy (SEM) images indicated that such adsorbents with a large surface area have more dye adsorption potential whereas the variation in dye adsorption occurs due to variation in surface area. From the overall experimental data, maximum removal of 95.39% and 87.92% was found for Methylene Blue and Reactive Blue-250 respectively by sawdust, and 90.64% removal of Methylene Blue by using fish scale.

关键词： Textile Wastewater Ionic Dyes Removal Activated Carbon Adsorbent

Bilayer expurgated LDPC codes with uncoded relaying

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Digital Communications and Networks 2017年第3期3卷 176-179页

作者： md. Noor-A-Rahim Nan Zhang Sk. md. Rabiul Islam Y.L. Guan Centre for Infocomm Technology (INFINITUS) Nanyang Technological University Singapore Institute for TelecommunicationsResearch University of South Australia Adelaide Australia Dept.of Eleetronics and Communication Engineering Khulna University of Engineering & Technology Bangladesh

Bilayer low-density parity-check （LDPC） codes are an effective coding technique for decode-and-forward relaying, where the relay forwards extra parity bits to help the destination to decode the source bits correctly. In the existing bilayer coding scheme, these parity bits are protected by an error correcting code and assumed reliably available at the receiver. We propose an uneoded relaying scheme, where the extra parity bits are forwarded to the destination without any protection. Through density evolution analysis and simulation results, we show that our proposed scheme achieves better performance in terms of bit erasure probability than the existing relaying scheme. In addition, our proposed scheme results in lower complexity at the relay.

关键词： Bilayer codes LDPC codes Density evolution Decode-and-forward relaying

Efficient Feature Selection and Machine Learning Based ADHD Detection Using EEG Signal

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Computers, Materials & Continua 2022年第9期72卷 5179-5195页

作者： md.Maniruzzaman Jungpil Shin md.Al Mehedi hasan Akira Yasumura School of Computer Science and Engineering The University of AizuAizuwakamatsuFukushima965-8580Japan Faculty of Humanities and Social Science Kumamoto UniversityChuo-kuKumamotoJapan

Attention deficit hyperactivity disorder(ADHD)is one of the most common psychiatric and neurobehavioral disorders in children,affecting 11%of children *** study aimed to propose a machine learning(ML)-based algorithm for discriminating ADHD from healthy children using their electroencephalography(EEG)*** study included 61 children with ADHD and 60 healthy children aged 7–12 *** morphological and time-domain features were extracted from EEG *** t-test(p-value<0.05)and least absolute shrinkage and selection operator(LASSO)were used to select potential features of children with ADHD and enhance the classification *** selected potential features were used in four ML-based algorithms,including support vector machine(SVM),k-nearest neighbors,multilayer perceptron(MLP),and logistic regression,to classify ADHD and healthy *** overall prevalence of boys and girls with ADHD was 48.9%and 56.5%,*** average age of children with ADHD was 9.6±1.8 *** results illustrated that the combination of LASSO with SVM classifier achieved the highest accuracy of 94.2%,sensitivity of 93.3%,F1-score of 91.9%,and AUC of *** results also illustrated that MLP was the second-best ML-based classifier,which gave 93.4%accuracy,91.7%sensitivity,91.1%F1-score,and 0.960 *** findings indicated that the combination of the LASSO-based feature selection method and SVM classifier can be a useful tool for selecting reliable/potential features and classifying ADHD and healthy *** proposed ML-based algorithms could be useful for the early diagnosis of children with ADHD.

关键词： ADHD feature extraction feature selection classification machine learning

Application of GIS in General Soil Mapping of Bangladesh

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Journal of Geographic Information System 2017年第5期9卷 604-621页

作者： md. Azharul Islam md. Amit hasan Murad Ahmed Farukh Department of Environmental Science Faculty of Agriculture Bangladesh Agricultural University Mymensingh Bangladesh

Bangladesh is a densely populated country where food crisis is one of the major issues where proper soil mapping is lacking till now. The purpose of this study is to prepare soil mapping of Bangladesh including different soil factors like pH, salinity, nutrients, texture, porosity, toxicity etc., along with general soil types and land availability through application of Geographical Information System (GIS). Q-GIS software and secondary data are used in this study. In present study, it was found that 12 types of soil texture were present in all around of Bangladesh and the maximum percentage of soil porosity values varied from 20% to 70%. A medium range of soil organic matter and strongly acidic soil was found all around the Bangladesh. It was found that the southern part of Bangladesh had slightly saline to highly saline soil. The major part of Bangladesh had medium high land which is very much preferable to agriculture. In Bangladesh, three categories of land such as highland, medium highland and low land cover 29%, 35% and 21% of total land, respectively. Agriculture land covers 9.5 million hectares in Bangladesh. The shifting rate based on agricultural use had been reported to be about 1% per year. At present, the amount of forest land covers 9.84% of total land of our country but 1976 it was 12.11%. Mangrove is now at 4.07% of total land mass of our country. In generally, 20 types of soils were found all around the country. Mapping of soil types described these 20 general soil types under 5 main categories and these are calcareous soil, non-calcareous soil, terrace soil, gray soil, peat and hill soils. This study will be helpful for the cultivator to cultivate appropriate crops in appropriate places after exploration at a glance.

关键词： GIS Soil Mapping Soil Type Bangladesh

Estimation of Vitamins B-Complex (B2, B3, B5and B6) of Some Leafy Vegetables Indigenous to Bangladesh by HPLC Method

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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

Quasi-inverse Pendulum Model of 12 DoF Bipedal Walking

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International Journal of Automation and computing 2017年第2期14卷 179-190页

作者： M. Akhtaruzzaman Amir A. Shafie md. Raisuddin Khan Department of Mechatronics Engineering Kulliyyah of Engineering International Islamic University Malaysia Kuala Lumpur 53100 Malaysia

This paper presents modeling of a 12-degree of freedom （DoF） bipedal robot, focusing on the lower limbs of the system, and trajectory design for walking on straight path. Gait trajectories are designed by modeling of center of mass （CoM） trajectory and swing foot ankle trajectory based on stance foot ankle. The dynamic equations of motion of the bipedal robot are derived by considering the system as a quasi inverted pendulmn （QIP） model. The direction and acceleration of CoM movement of the QIP model is determined by the position of CoM relative to the centre of pressure （COP）. To determine heel-contact and toe-off, two custom designed switches are attached with heel and toe positions of each foot. Four force sensitive resistor （FSR） sensors are also placed at the plantar surface to measure pressure that is induced on each foot while walking which leads to the calculation of CoP trajectory. The paper also describes forward kinematic （FIK） and inverse kinematic （IK） investigations of the biped model where Denavit-Hartenberg （D-H） representation and Geometric-Trigonometric （G-T） formulation approach are applied. Experiments are carried out to ensure the reliability of the proposed model where the links of the bipedal system follow the best possible trajectories while walking on straight path.

关键词： Humanoid robot quasi-inverse pendulum gait trajectory planning Anthropoid.

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

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