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Study of the Physical, Mechanical and Thermal Properties of Banana Fiber Reinforced HDPE Composites

Materials Sciences and Applications 2020年第4期11卷 245-262页

作者： Budrun Neher rakib hossain Kaniz Fatima M. A. Gafur Md. Abul hossain Farid Ahmed Department of Physics Jahangirnagar University Dhaka Bangladesh Department of Physics Bangabandhu Sheikh Mujibur Rahman Science & Technology University Gopalganj Bangladesh PP and PDC Bangladesh Council of Scientific and Industrial Research Dhaka Bangladesh

Natural fiber reinforced composite materials are replacing the conventional materials, owing to their excellent physical, mechanical, electrical, and thermal properties. Also they increase biodegradability, reduce cost and decrease environmental pollution and hazards. In this study, obsolete high density polyethylene (HDPE) has used as polymer matrix and banana fiber as reinforcement material. Composites (5%, 10%, 15% and 20% of fiber contents) were made by hot press molding method by using Paul-Otto Weber Hydraulic press machine. The physical, mechanical and thermal properties of banana fiber-HDPE composites were studied and investigated the increment or decrement nature of different properties due to addition of banana fiber in BF-HDPE composites. The bulk density of composites increased with the increase wt. (%) of fiber content in composites. Water absorption ability of banana fiber and BF-HDPE composites also increased with the increase of wt. (%) of fiber content in composites and with socking time. Tensile strength of the BF-HDPE composites increased with the increase of fiber content in both cases (continuous aligned fiber orientation and continuous bidirectional fiber orientation). Moreover, the tensile strength of BF-HDPE composites with continuous aligned fiber orientation was greater than that of continuous bidirectional fiber orientation. At first, the flexural strength increased for 5% BF-HDPE composites then the value decreased for other higher compositions. The flexural strength of continuous aligned fiber orientation was slightly greater than that of continuous bidirectional fiber orientation and composite with 5% banana fiber showed better flexural properties than others. Leeb’s rebound hardness decreased with the increase of fiber addition. Different thermal properties like TG/DTG, DTA of the obsolete HDPE and BF-HDPE composites were studied using thermo gravimetric analyzer and it was found that composite with 20% fiber content was more thermally

关键词： BF-HDPE Water Absorption Tensile Strength Hardness TG-DTG

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Study of the Physical and Mechanical Properties of Coconut Spathe Fiber Reinforced Obsolete Polymer Composites

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Materials Sciences and Applications 2021年第5期12卷 223-238页

作者： Rabeya Akter Budrun Neher M. A. Gafur rakib hossain Farid Ahmed Department of Physics Jahangirnagar University Dhaka Bangladesh Pilot Plant and Process Development Centre Bangladesh Council of Scientific and Industrial Research Dhaka Bangladesh Department of Physics Bangabandhu Sheikh Mujibur Rahman Science & Technology University Gopalganj Bangladesh

Fiber-reinforced polymer (FRP) composites have gradually gained wide acceptance as engineering material applications due to their unique advantages including their high strength-to-weight ratio and excellent corrosion resistance. This study was carried out with composites prepared by hot press molding method using coconut spathe fiber as reinforcing material and HDPE (from HDPE can as obsolete polymer) as polymer matrix. Composites were made at 150°C under 60 kN load by taking diverse weight percentage (wt.%) of fiber from 0 to 20 of its total weight. In this research investigation, different properties of the composites such as bulk density, water absorption, tensile and flexural properties, impact strength and hardness test properties were carried out. The fiber content enhancement increases the bulk density in all composites. The rate of water absorption improves with the improvement of fiber addition with respect to HDPE in all composites. But the water absorption was not increased uniformly with the increase of fiber addition in composites. In all cases, composites absorbed water very rapidly up to 80 hrs and then water absorption is in saturated condition. The mechanical properties like tensile strength (TS), flexural strength (FS), impact strength (IS) and hardness were observed to be comparatively more enhanced for 5% composite, while further increasing of fiber addition, all mechanical properties changes irregularly. The irregular nature of change might be caused due to the over loading of fiber in polymer matrix.

关键词： Coconut Spathe Fiber Obsolete Polymer Matrix Tensile Strength Impact Strength

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Fabrication and Characterization on Physico-Mechanical and Structural Properties of Sawdust Reinforced Acrylonitrile Butadiene Styrene (ABS) Composites

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Materials Sciences and Applications 2020年第9期11卷 644-658页

作者： Budrun Neher Nabila Tasnim Nova rakib hossain M. A. Gafur Farid Ahmed Department of Physics Jahangirnagar University Dhaka Bangladesh Department of Physics Bangabandhu Sheikh Mujibur Rahman Science & Technology University Gopalganj Bangladesh PP and PDC Bangladesh Council of Scientific and Industrial Research Dhaka Bangladesh

The sawdust reinforced Acrylonitrile Butadiene Styrene (ABS) composites were prepared by using hot press molding machine for five different wt% (0%, 5%, 10%, 15% and 20%) at 180°C temperature and 50 KN load. Sawdust was collected from local saw mill of Savar, Dhaka, Bangladesh and ABS polymer was collected from local market of Dhaka, Bangladesh. In this study, different properties of composites like physical (bulk density and water absorption), mechanical (tensile properties and hardness) and structural (Fourier Transform Infrared Spectroscopy) properties were studied. The bulk density of composites was not altered consistently and it gave greater value for 5% and 20% composites. The water absorption enhanced for all composites with the accumulation of fiber content and soaking time. The reduction of tensile strength and Leeb’s rebound hardness of the composites were observed with the increase of the fiber content in all compositions. Maximum (%) of elongation was found for 5% composite, and then it gradually decreased;however, elastic modulus increased with the increased of fiber content in composites. Fourier Transform Infrared (FTIR) spectroscopy study was done for structural characterization. It was found that there was a new bond (C≡C) stretching formed for 20% composite;moreover, C-H rocking for 0% composite was broken for all other composites after the addition of sawdust in ABS polymer matrix.

关键词： Sawdust-ABS Composite Hot Press Molding Machine Tensile Strength Leeb’s Rebound Hardness FTIR Spectroscopy

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Effectiveness of Wastewater-Based Epidemiology as an Early Warning Tool to Detect SARS-CoV-2 (COVID-19)

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Health 2024年第7期16卷 635-656页

作者： rakib Ahmed Chowdhury Daniel E. Meeroff Sumaiya Sharmin Alamgir Kabir Sara Hollenbeck Valerie Dalencourt Thu Nguyen Zack Farmer Frederick Bloetscher Waseem Asghar Stacey Volnick College of Engineering and Computer Science Florida Atlantic University Boca Raton FL USA

Medical diagnostic tests to detect Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) for individuals in the United States were initially limited to people who were traveling or symptomatic to track disease incidence due to the cost of providing testing for all people in a community on a routine basis. As an alternative to randomly sampling large groups of people to track disease incidence at significant cost, wastewater-based epidemiology (WBE) is a well-established and cost-effective technique to passively measure the prevalence of disease in communities without requiring invasive testing. WBE can also be used as a forecasting tool since the virus is shed in individuals prior to developing symptoms that might otherwise prompt testing. This study applied the WBE approach to understand its effectiveness as a possible forecasting tool by monitoring the SARS-CoV-2 levels in raw wastewater sampled from sewer lift stations at a large public university campus setting including dormitories, academic buildings, and athletic facilities. The WBE analysis was conducted by sampling from building-specific lift stations and enumerating target viral copies using RT-qPCR analysis. The WBE results were compared with the 7-day rolling averages of confirmed infected individuals for the following week after the wastewater sample analysis. In most cases, changes in the WBE outcomes were followed by similar trends in the clinical data. The positive predictive value of the applied WBE approach was 86% for the following week of the sample collection. In contrast, positive correlations between the two data with Spearmen correlation (rs) ranged from 0.16 to 0.36. A stronger correlation (rs = 0.18 to 0.51) was observed when WBE results were compared with COVID-19 cases identified on the next day of the sampling events. The P value of 0.007 for Dorm A suggests high significance, while moderate significance was observed for the other dormitories (B, C, and D). The outcomes of this in

关键词： SARS-CoV-2 Wastewater Detection Wastewater-Based Epidemiology (WBE)

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East African topography and volcanism explained by a single,migrating plume

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Geoscience Frontiers 2020年第5期11卷 1669-1680页

作者： rakib Hassan Simon E.Williams Michael Gurnis Dietmar Muller School of Geosciences Room 412Madsen Building F09 Eastern AvenueThe University of SydneyNSW2006Australia Seismological Laboratory California Institute of TechnologyPasadenaCA91125USA Now at Geoscience Australia GPO Box 378CanberraACT2601Australia State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China

Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle *** models involving one or more fixed plumes beneath the northeastward migrating African plate have been suggested to explain the space-time distribution of magmatism in east *** devise paleogeographically constrained global models of mantle convection and,based on the evolution of flow in the deepest lower mantle,show that the Afar plume migrated southward throughout its *** models suggest that the mobile Afar plume provides a dynamically consistent explanation for the spatial extent of the southward propagation of the east African rift system(EARS),which is difficult to explain by the northeastward migration of Africa over one or more fixed plumes alone,over the last≈45 *** further show that the age-progression of volcanism associated with the southward propagation of EARS is consistent with the apparent surface hotspot motion that results from southward motion of the modelled Afar plume beneath the northeastward migrating African *** models suggest that the Afar plume became weaker as it migrated southwards,consistent with trends observed in the geochemical record.

关键词： Numerical mantle flow models Deep mantle flow LLSVP morphology Plume dynamics Plume motion Dynamic topography

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In vitro α-amylase inhibitory activity and in vivo hypoglycemic effect of methanol extract of Citrus macroptera ***

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Asian Pacific Journal of Tropical Biomedicine 2014年第6期4卷 473-479页

作者： Nizam Uddin rakib Hasan Monir hossain Arjyabrata Sarker A.H.M.Nazmul Hasan A.F.M.Mahmudul Islam Mohd.Motaher H.Chowdhury Sohel Rana Laboratory of Natural Products Research Department of PharmacyJahangirnagar University

Objective:To investigate the therapeutic effects of methanol extract of Citrus macroptera Montr,fruit inα-amylase inhibitory activity(in vitro)and hypoglycemic activity in normal and glucose induced hyperglycemic rats(in vivo).Methods:Fruits of Citrus macroptera without rind was extracted with pure methanol following cold extraction and tested for presence of phytochemical constituents,α-amylase inhibitory activity,and hypoglycemic effect in normal rats and glucose induced hyperglycemic ***:Presence of saponin,steroid and terpenoid were identified in the *** results showed that fruit extract had moderateα-amylase inhibitory activity[IC_(50)value=(3.638±0.190)mg/mL]as compared to *** at 500 mg/kg and 1000 mg/kg doses fruit extract significantly(P<0.05 and P<0.01 respectively)reduced fasting blood glucose level in normal rats as compared to glibenclamide(5 mg/kg).In oral glucose tolerance test,500 mg/kg dose significantly reduced blood glucose level(P<0.05)at 2 h but 1000 mg/kg dose significantly reduced blood glucose level at 2 h and 3 h(P<0.05 and P<0.01 respectively)whereas glibenclamide(5 mg/kg)significantly reduced glucose level at every hour after *** time effect is also considered extremely significant with F value=23.83 and P value=0.0001 in oral glucose tolerance ***:These findings suggest that the plant may be a potential source for the development of new oral hypoglycemic agent.

关键词： Diabetes mellitus Hypoglycemic Citrus macroptera α-Amylase OGTT Glibenclamide

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Mechanical Properties of Weft-Knitted Spacer Fabrics Integrated with Silica Aerogels

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Journal of Donghua University(English Edition) 2019年第6期36卷 559-563页

作者： SYED Rashedul Islam YU Weidong JIANG Jinhua MOHAMMAD Abu Nasir rakib Department of Textile Engineering College of TextilesDonghua UniversityShanghai 201620China Key Laboratory of Textile Science&Technology Ministry of EducationShanghai201620China

The work investigated surface and mechanical properties of untreated and treated three-layered weftknitted spacer *** order to optimize the mechanical properties of weft-knitted spacer fabrics,silica aerogels(SAs)coating was *** electron microscopy(SEM)images of untreated and treated spacer fabrics were analyzed to ensure the presence of SAs on the coated spacer *** basic properties of uncoated and coated weftknitted spacer fabrics were studied and *** strength and initial modulus were studied according to the GB/T3923 test standard YG026 MB-250 by testing ***,compression properties of spacer fabrics were also tested by HD026 G test *** this testing,work of compression,the linearity of compression,recovery work of compression and other parameters were calculated from stress and strain *** was found that SAs coating has a significant influence on the mechanical properties of weftknitted spacer *** statistical analysis also verified the significant performance(P value smaller than 0.05)of treated fabric samples at the 0.05 level.

关键词： 3D weft-knitted spacer fabrics silica aerogels(SAs)coating tensile strength initial modulus compression properties

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Development and Performance Study of Controlled Atmosphere for Fresh Tomato

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World Journal of Engineering and Technology 2016年第2期4卷 168-175页

作者： Md. Farid Ahmed Md. Zahirul Islam Md. Sazzat hossain Sarker S. M. Kamrul Hasan rakib Mizan Department of Food Engineering and Technology Hajee Mohammad Danesh Science and Technology University Dinajpur Bangladesh Department of Food Processing and Preservation Hajee Mohammad Danesh Science and Technology University Dinajpur Bangladesh

Development of a controlled atmosphere (CA) plant and shelf-life of fresh tomatoes at different storage conditions were studied in this research. The controlled chamber (4.5' × 4.5' × 4.5') with supplement of 1% L-ascorbic acid as antioxidant source was constructed using locally available materials. Fresh tomatoes were kept with wrapping by low density polyethylene under refrigerated and CA storage conditions. The maximum shelf-life of fresh tomato was 42 days under CA condition and followed by 35 days in refrigeration condition. Though initial cost of controlled atmosphere was high but it resulted in maximum shelf life of tomato. However, CA condition retained the physiological changes namely, color change, TSS, and weight loss of fresh tomatoes than that of stored in refrigerated condition. From nutritional point of view, it was concluded that developed CA plant could be used to extend the shelf-life of fresh tomatoes with minimum physico-chemical changes throughout the storage period.

关键词： Controlled Atmosphere Tomato Shelf-Life Storage Study Weight Loss

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Effect of Elastane on Physical Properties of 1×1 Knit Rib Fabrics

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Journal of Donghua University(English Edition) 2020年第3期37卷 207-210页

作者： MOHAMMAD Abu Nasir rakib LI Wei SYED Rashedul Islam MD Obaidul Islam Department of Textile Engineering College of TextilesDonghua UniversityShanghai 201620China Key Laboratory of Textile Science&Technology Ministry of EducationShanghai 201620China Department of Textile Engineering BGMEA University of Fashion and TechnologyBangladesh

Because of wearing and washing the knit rib fabrics are highly vulnerable to lose their dimensional *** work investigated the physical properties of 1×1 knit rib fabrics with or without *** fabrics made from 100%cotton yarn were compared with the fabrics made from cotton/elastane(95%/5%)blended yarns by Lisky circular knitting ***,shrinkage,spirality,and bursting strength were tested by the ICI pilling test box,Wascator,and TruBurst machine to demonstrate the effect of elastane on fabric *** results showed that elastane has a noteworthy impact on the physical properties of 1×1 knit rib fabrics which can make the fabrics more durable and dimensionally stable in practice.

关键词： 1×1 knit rib fabrics elastane cotton pilling spirality bursting strength shrinkage test

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YOLObin: Non-Decomposable Garbage Identification and Classification Based on YOLOv7

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Journal of Computer and Communications 2022年第10期10卷 104-121页

作者： Md. rakib Jabed Md. Shamsuzzaman Department of Computer Science and Engineering Begum Rokey University Rangpur Bangladesh

In order to safeguard the biological framework on which human creatures depend for presence and make society feasible improvement, it is becoming increasingly important to classify garbage. In any case, individuals are not recognizable with the classification strategy, so it is troublesome for individuals to accurately get the classification of each kind of rubbish. A proper waste management system is a primary task in building a smart and healthy city. In arrange to direct individuals to classify garbage accurately, this paper proposes a strategy of rubbish classification and acknowledgment based on YOLOv7 which is a cutting edge real time object detector. Performance of this model is compared along with two other object detectors where Mask-RCNN achieved f-measurement of 85%, YOLOv5 achieved f-measurement of 95.1% and YOLOv7 achieved f-measurement 95.9%. We have used non-decomposable multiclass garbage images which entails messy backgrounds with unwanted images as well. Four classes of non-decomposable garbage data namely chips packet, plastic bottle, polythene and image with multiclass garbage with 1000 images are prepared for our dataset. Our experimental models performed well in classifying garbage images with cluttered backgrounds. We compared our test results to previous studies in which the majority of the models were tested and trained using laboratory images. The test comes about illustrates that the classification framework features a sensible degree of accuracy and the segmentation recognition impact is way better within the case of point-by-point picture, which can proficiently and helpfully total the rubbish classification errand.

关键词： Mask-RCNN YOLOv5 YOLOv7 Garbage Classification Machine Learning

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