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Fabrication and Characterization of Tungsten Heavy Alloys Using Chemical Reduction and Mechanical Alloying Methods

Open Journal of Applied Sciences 2013年第1期3卷 15-27页

作者： Zeinab Abdel Hamid Sayed Farag Moustafa Walid Mohamed Daoush fatema Abdel Mouez Mona Hassan Corrosion Control and Surface Protection Department Central Metallurgical R&D Institute Helwan Cairo Egypt Powder Technology Department Central Metallurgical R&D Institute Helwan Cairo Egypt

A novel reduction technique has been developed to synthesize nano-sized tungsten heavy alloys powders and compared with the same powders processed by mechanical alloying technique. In the first method, nano-sized tungsten heavy alloys powders have been obtained by reduction of precursors obtained by spray drying of several appropriate aqueous solutions, which were made from salts containing tungsten, cobalt, and nickel. By adjusting the stoichiometry of the component of the solutions, it is possible to obtain the desired chemical composition of the tungsten heavy alloys powders. In the second method, highly pure elemental powders of tungsten heavy alloys have been mechanically alloyed in a tumbler ball mill for different milling time. The investigated tungsten heavy alloy powders with the composition (95%W-3.5%Ni-1.5%Fe), (93%W-4.5%Ni-1.0%Fe-1.5%Co), and (90%W-6%Ni-4%Cu) have been prepared using both methods. The prepared powders have been compacted at 70 bar (200 MPa) and sintered in vacuum furnace at 1400℃. Vacuum sintering was carried out to achieve full densification of the produced tungsten heavy alloys. The investigated materials were going to be evaluated the physical and mechanical properties of the sintered parts such as density;electrical conductivity, hardness, and transverse rupture strength. The results reveal that, the grain size of alloys fabricated by chemical reduction technique (53.1 - 63.8 nm) is smaller than that fabricated by mechanical alloying technique (56.4 - 71.4 nm).

关键词： Tungsten Heavy Alloys Mechanical Alloying Chemical Reduction Powder Metallurgy Hardness Transverse Rupture Strength Conductivity

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Extraction of a novel tanning agent from indigenous plant bark and its application in leather processing

Collagen and Leather

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Collagen and Leather 2023年第01期 69-83页

作者： Raju Kumar Das Al Mizan fatema Tuj Zohra Sobur Ahmed Khondoker Shahin Ahmed Hemayet Hossain Institute of Leather Engineering and Technology (ILET) University of Dhaka Department of Leather Engineering Khulna University of Engineering & Technology (KUET) Department of Leather Engineering Faculty of EngineeringEge University BCSIR Laboratories Chemical Research DivisionBangladesh Council of Scientific and Industrial Research(BCSIR)

The use of vegetable tanning materials in leather processing has drawn attention as an alternative to basic chromium sulphate for its natural abundance and environmental *** this work,an attempt has been made to extract vegetable tannins from Xylocarpus granatum bark using different solvents(e.g.,water,methanol,ethanol,and chloroform)and compare with conventional vegetable tanning agents such as mimosa and *** highest extraction efficiency was observed 31.22% by *** presence of tannin content and polyphenolic compounds,e.g.(-)epicatechin(503 mg/100 g dry extract),catechin hydrate(218 mg/100 g dry extract),catechol(29 mg/100 g dry extract) were ensured by UV-Vis,FT-IR spectroscopy and ***,condensed tannins,moisture content,and pH of the methanol extracted tannin were found 47.80%,5.82%,and 3.97 *** leather tanned by Xylocarpus granatum tannin showed a shrinkage temperature of 86.34±1.52℃.Other properties such as tensile strength,tear strength,grain cracking load,and distention at grain cracking were comparable to conventional vegetabletanned *** cross-sectional morphology of the tanned leathers was also characterized by scanning electron microscopy(SEM) which revealed a compact structure of the leather *** light of the findings from the study,*** bark tannin could be a well alternative to chromium and a new source of vegetable tannin for the leather industry.

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In-VivoManagement of Purple Blotch of Onion Caused by Alternaria porri(Ellis) Cif. through Fungicides

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American Journal of Plant Sciences 2020年第11期11卷 1847-1859页

作者： Md. Mozidul Islam fatema Begum Nazmoon Nahar U. A. Habiba K. M. Fakruzzaman DAE Burirhat Rangpur Bangladesh Department of Plant Pathology Sher-e-Bangla Agriculture University Dhaka Bangladesh Agriculture Taragonj O/A Government College Taragonj Rangpur Bangladesh Hajee Mohammad Danesh Science and Technology University Dinajpur Bangladesh Power Plant Commission Operation & Maintenance Welfare (Bd) Ltd. Dhaka Bangladesh

An experiment was carried out to study the outcome of environmental factors (Temperature, Relative Humidity, Rainfall) and management of the purple blotch disease of onion using five treatments (Rovral + Ridoil gold with 3,4,5,6 sprays and control). The Taherpuri variety was used during the 2015-2016 cropping seasons at BARI, Gazipur, Bangladesh. In the experiment, the purple blotch disease surfaced at the end of January 2016 and was severe in late February to March (PDI 76.12%) due to temperature and RH above 24°C and 95%, respectively. As for the chemical control, the PDI for the treatments ranged from 50.66% to 83.33%. Significantly higher stem height was recorded by T4 (68.06 cm), where six sprays of Rovral + Ridomil were applied. The minimum stem height was recorded in T5 (59.23 cm). The maximum stem number per hill was recorded in T4 (2.30) numerically but differed significantly with T5 (2.00), where fungicides were not applied. The maximum lesion area was measured in T5

关键词： Purple Blotch Alternaria porri Fungicides PDI Yield

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PRACTICAL SOLUTIONS OF MULTI-OBJECTIVE SYSTEM RELIABILITY DESIGN PROBLEMS USING GENETIC ALGORITHMS

PRACTICAL SOLUTIONS OF MULTI-OBJECTIVE SYSTEM RELIABILITY DE...

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第四届质量与可靠性国际会议

作者： HEIDI A.TABOADA fatema BAHERANWALA DAVID W.COIT NARUEMON WATTANAPONOSAKORN Department of Industrial and Systems Engineering Rutgers University Piscataway NJ 08854 USA Department of Industrial and Systems Engineering Rutgers University Piscataway NJ 08854 USA Department of Industrial and Systems Engineering Rutgers University Piscataway NJ 08854 USA King Mongkut’s University of Technology Thonburi Bangkok Thailand

＜正＞ Two methods are presented as practical approaches to reduce the size of the Pareto optimal set of multiple-objective system reliability design problems. The first method is a pseudo-ranking scheme that helps the decision maker select solutions that reflect his/her preferences. In the second approach we used clustering techniques used in data mining, to group the data by using the k-means algorithm to find clusters of similar solutions, which allows the decision maker to have just k solutions to choose from without using any objective function preference information. Under this second method, from the clustered Pareto optimal set, we attempted to find solutions which are likely to be more relevant to the decision maker, which are solutions where a small improvement in one objective would lead to a large deterioration in at least one other objective. To show how these methods work, the well-known Redundancy Allocation Problem was solved as a multiple objective problem by using the NSGA genetic algorithm to initially find the Pareto optimal solutions, and then, the two proposed methods are applied to prune the Pareto set.

关键词： System Reliability multi-objective optimization Pareto optimal set cluster analysis.

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THE EXPERIMENTAL STUDY OF STRESS-RELATED PATHOLOGICAL CHANGES IN CEREBRAL VENOUS BLOOD FLOW IN NEWBORN RATS ASSESSED BY DOCT

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Journal of Innovative Optical Health Sciences 2013年第3期6卷 76-85页

作者： OXANA V.SEMYACHKINA-GLUSHKOVSKAYA VLADISLAV V.LYCHAGOV OLGA A.BIBIKOVA IGOR A.SEMYACHKIN-GLUSHKOVSKIY SERGEY S.SINDEEV EKATERINAM.ZINCHENKO MOHHANAD M.KASSIM AL-FATLE fatema ALI AL HASSANI LEITH MARIA V.ULANOVA VALERY V.TUCHIN Department of Biology Saratov State UniversityAstrachanskaya Str.83410012 SaratovRussian Federation Department of Biology Al-Mustansiriya UniversityBaghdadIraq Institute of Precise Mechanics and Control of Russia Academy of Science Rabochaya 28 410028 SaratovRussian Federation Optoelectronics and Measurement Techniques Laboratory University of Oulu P.O.BOX 450090014 University of OuluFinland

In experiments on newbom rats with stress related intracrani al hemorhage(ICH)using Doppler optical coberence tomognaphy(DOCT)we have shown that latent stage of ICH(4 h after stress)is characterized by decrease of venous blood outflow and the loss of sensitivity of sagittal vein to vasoconstrictor ffect of *** incidence of ICH(24 h after stress)was accompanied by progressi on of early pathological changes in cerebral venous blood flow(CVBF)and development of venous *** into consideration of this fact,we suggest that the suppression of CVBF related to the severity to the deleterious effect of stress on the brain hemodynamics in newborn *** facts allow us to conclude that the venous insufficiency with the loss of vasoconstrictor response to adrenaline is an informative and sensitive component of pattern of CVBF that can be important diagnostic criteria of risk of ICH development in newborns.

关键词： Doppler optical coherence tomography stress related intracnanial hemorthage cerebral venous blood flow adrenaline

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Pre-Extensively Drug Resistant Tuberculosis (Pre-XDR-TB) among Pulmonary Multidrug Resistant Tuberculosis (MDR-TB) Patients in Bangladesh

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Journal of Tuberculosis Research 2018年第3期6卷 199-206页

作者： Tamanna Tasnim Shirin Tarafder fatema Mohammad Alam Humayun Sattar S. M. Mostofa Kamal Department of Microbiology and Immunology Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka Bangladesh National Tuberculosis Reference Laboratory (NTRL) National Institute of Diseases of the Chest and Hospital (NIDCH) Dhaka Bangladesh

Background & Objectives: Emergence of drug resistant Tuberculosis (TB) is a major obstacle in the TB control programme of Bangladesh. This study was carried out to detect pre-extensively drug resistant TB (pre-XDR-TB) cases among the multidrug resistant TB (MDR-TB) patients in Bangladesh, as the early detection of pre-XDR-TB can guide clinicians in the appropriate modification of MDR-TB treatment regimen with effective drugs to prevent treatment failure. Methodology: A total of 68 MDR-TB cases were enrolled in this study. Multiplex Real-time PCR was done to detect pre-XDR-TB cases directly from sputum samples of MDR-TB patients. Results: Out of 68 MDR-TB cases 11 (16.18%) cases were detected as pre-XDR-TB. The resistant profile of the 11 pre-XDR-TB revealed 9 (81.82%) cases of fluoroquinolone (FLQ) resistant pre-XDR-TB and 2 (18.18%) cases of injectable second line (ISL) agent resistant pre-XDR-TB. Out of 11 pre-XDR-TB cases 7 (63.64%) cases had history of taking treatment for MDR-TB regularly, 1 (9.09%) case had history of taking treatment for MDR-TB irregularly and 3 (27.27%) cases had no history of taking treatment for MDR-TB. Conclusion: This study encountered a high rate of pre-XDR-TB cases along with a significant number of primarily resistant bacilli which is of concern in the management of MDR-TB. It is evident that Bangladesh is in urgent need to device strategies for rapid and early detection of pre-XDR-TB in order to prevent treatment failure of MDR-TB cases and also to halt the progression of MDR-TB cases to extensively drug resistant TB (XDR-TB), which is not only difficult but also very expensive to treat.

关键词： Pre-XDR-TB MDR-TB Bangladesh

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Isolation of Multi-Drug Resistant (MDR) and Extensively Drug Resistant (XDR) Salmonella typhifrom Blood Samples of Patients Attending Tertiary Medical Centre in Dhaka City, Bangladesh

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Advances in Microbiology 2021年第9期11卷 488-498页

作者： Oshin Ghurnee Amit Kumar Ghosh Maruf Abony Shahrin Akhter Aurin Aneeka Nawar fatema Avijit Banik Zakaria Ahmed Department of Microbiology Primeasia University Dhaka Bangladesh Microbiology Department Technology Wing Bangladesh Jute Research Institute Dhaka Bangladesh

Objective: Almost all year round occurrence of typhoid fever remains a major public health issue in Bangladesh. In recent years, there has been a significant rise in the prevalence of multi-drug resistance Salmonella typhi in Dhaka city. The major objective of this study was to observe the prevalence of multi-drug and Extended drug-resistant patterns of typhoidal Salmonella typhi among the patients attending a tertiary medical center by conventional culture and serologic test. Materials and Methods: Blood was collected by syringe and equally divided between aerobic & anaerobic BacT Alert bottle, 10 mL for paediatrics. Post isolation Salmonella strains were identified and were tested for antibiotic resistance. Results: A total of 600 blood samples of typhoid suspected patients were tested, where 32.5% came out positive, which were identified as Salmonella typhi. These isolates were susceptible to carbapenem drugs but highly resistant to Fluoroquinolones and Aminoglycosides antibiotics. Discussion: It was seen that 73.23% of isolates among male patients were extensively drug-resistant (XDR) meaning that isolates were sensitive against only one or two antibiotics while in the female it was 58.46%. Isolates from Female patients showed higher multi-drug resistant (MDR) (26.15%) isolates resistance to multiple antibiotics in comparison to isolates from the male (16.54%). 87.19% of the strains showed high drug resistance (XDR and MDR). Conclusion: The emergence of XDR and MDR strains of S. typhi in recent years is becoming a significant threat. Although no PAN-Drug resistance (resistant against all tested drugs) was observed in the current study, a high level of XDR and MDR isolates are indicating that the scenario might take place sooner than later.

关键词： MDR XDR S. typhi Blood Samples Typhoid Fever Bangladesh

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Isolation of Bulk Amount of Piperine as Active Pharmaceutical Ingredient (API) from Black Pepper and White Pepper (Piper nigrumL.)

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Pharmacology & Pharmacy 2017年第7期8卷 253-262页

作者： Zihan Rahman Khan fatema Moni Suriya Sharmin Muhammad Abdullah Al-Mansur Abdul Gafur Obaidur Rahman Farhana Afroz Pharmaceutical Sciences Research Division BCSIR Laboratories Dhaka Bangladesh Institute of National Analytical Research and Service (INARS) BCSIR Dhaka Bangladesh Pilot Plant & Process Development Center (PP & PDC) BCSIR Dhaka Bangladesh Department of Biology & Chemistry North South University Dhaka Bangladesh

In the pharmaceutical world the majority of the active pharmaceutical ingredients (API) have been obtained from the natural products. Piperine is such naturally occurring alkaloid which can be considered as major bioactive phytochemical having broad spectrum of pharmacological activities. It is obtained from the most valuable ethnomedicinal spices peppercorns i.e. black pepper and white pepper, which are the fruits of the Asian vine Piper nigrum L. Because of the widespread traditional uses of this medicinal compound, present article reveals a simple and effective isolation method of bulk piperine. The novelty of this investigation is to provide an idea for utilizing such natural method of large scale commercial piperine production as API drug in spite of chemical synthesis. Piperine was isolated in a pure crystal form and characterized by its melting point, X-Ray diffraction (XRD) studies and spectral data, including two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy. Chromatographic techniques like Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) were applied to determine the purity of the yielded piperine. It was found that piperine yield from black pepper was within 2.5% - 3.0% and from white pepper within 4.0% - 4.5% and the purity of the yielded piperine was found to be up to 98.5% for black pepper and 98.2% for white pepper. Considering this yield value and purity it is indicated that, such effective isolation method can be successfully utilized for industrial large-scale production commercially. According to the result, it can be claimed that, as a natural product the isolated piperine can also be utilized as API drug like other expensive chemically synthesized piperine in different drug formulation.

关键词： Piper nigrum L NMR Spectroscopy X-Ray Diffraction Studies Bulk Piperine

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Efficacy of Less Toxic Phytochemicals to Prevent the Insect Vector of Mungbean Yellow Mosaic Virus(MYMV)

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American Journal of Plant Sciences 2019年第1期10卷 44-54页

作者： Jesmin Nahar Joly Hosna Ara Chowdhury Abdullah Ali Imtiaz fatema Begum Hasibur Rahman Md. Belal Hossain Department of Plant Pathology Sher-e-Bangla Agricultural University Dhaka Bangladesh

Planting material BARI mungbean-5 and two phytochemicals viz. Imitaf, active ingredient imidacloprid and ACmix, active ingredient chloropyriphos (50%) + Cypermethrin (5%) were used in this experiment. In case of Imitaf, the lowest percent disease incidence (10.12% per plant and 3.51% per plot) and severity (7.21%) were recorded in four times spray (T4) at 70 DAS. The highest percent disease incidence (36.50% per plant and 11.37% per plot) and severity (23.33%) were recorded in no spray (T0) at 70 DAS. In case of ACmix, the lowest percent disease incidence (12.21% per plant and 4.21% per plot) and severity (7.53%) were recorded in four times spray (T4) at 70 DAS. The highest percent disease incidence (36.49% per plant and 11.37% per plot) and severity (36.67%) was recorded in T0 at 70 DAS. The highest number of flower, no of pod and yield was found in four times spray (T4) that was higher in Imitaf than ACmix. The highest chlorophyll content was recorded in four times spray (T4) for Imitaf (49.62 μmol·m-2·s-1) and ACmix (56.80 μmol·m-2·s-1), and the lowest chlorophyll content was recorded in T0 for Imitaf (42.01 μmol·m-2·s-1) and ACmix (48.34 μmol·m-2·s-1). However from the results of this experiment it was revealed that Imitaf gave the better performance to control the insect vector (Whitefly) of MYMV with four times spray.

关键词： Mungbean MYMV Whitefly Phytochemicals Bangladesh

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A New Regression Type Estimator and Its Application in Survey Sampling

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Open Journal of Statistics 2020年第6期10卷 1010-1019页

作者： M. Zahid Hasan M. Sultana K. fatema Md. Ali Hossain M. Murad Hossain Department of Statistics Faculty of Science Bangabandhu Sheikh Mujibur Rahman Science and Technology University Gopalganj Bangladesh Department of Mathematics Faculty of Science Bangabandhu Sheikh Mujibur Rahman Science and Technology University Gopalganj Bangladesh

In the present time, a large number of modified estimators have been proposed by authors to obtain efficiency. In this study, we suggested an alternative regression type estimator for estimating finite population means when there is either a positive or negative correlation between study variables and auxiliary variables. We obtained bias and mean square error equation of the proposed estimator ignoring the first-order approximation and found the theoretical conditions that make proposed estimator more efficient than simple random sampling mean estimator, product estimator and ratio estimator. In addition, these conditions are supported by a numerical example and it has been concluded that the proposed estimator performed better comparing with the usual simple random sampling mean estimator, ratio estimator and product estimator.

关键词： Auxiliary Information Bias Efficiency Mean Square Error Product and Ratio Estimator

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