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Influence of Ni substitution on structural,morphological,dielectric,magnetic and optical properties of Cu-Zn ferrite by double sintering sol–gel technique

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Journal of Advanced Dielectrics 2019年第2期9卷 63-71页

作者： Mohammad Sajjad Hossain Yeasmin Akter Mohammad Shahjahan Muhammad Shahriar Bashar MostHosney ara begum MdMoazzem Hossain Suravi Islam Nazia Khatun MdAl-Mamun Industrial Physics Division BCSIR Laboratories Dhaka BCSIRDhaka-1205Bangladesh Department of Physics University of Chittagong Chottogram-4331Bangladesh Institute of Fuel Research and Development BCSIR Dhaka-1205Bangladesh Bangladesh Atomic Energy Centre BAEC Dhaka-1000Bangladesh

Polycrystalline NiCuZn ferrite(Ni_(x)Cu_(0.3)Zn(0.7-x)Fe_(2)O_(4);x=0.2,0.3,0.4 and 0.5)were prepared through solgel auto combustion method applying double sintering ***,morphological,elemental analyses(EDS),Fourier-transform infrared spectroscopy(FTIR),Direct Current(DC)electrical resistivity,dielectric,magnetic and optical properties of prepared samples were *** profiles reveal the formation of simple cubic spinel structure without any traceable *** average crystallite size lies within the range of 22–29 *** parameter decreases with increasing Ni *** temperature DC resistivity was recorded from 6:39×10^(5)to 3:79×10^(5)Ω*** dielectric constant(ε)and loss factor(tanδ)were decreased with increase of frequency while AC conductivity *** absorption peak occurred at three different frequency ranges at 570-577 cm^(-1),1635-1662 cm^(-1)and 3439–3448 cm^(-1).Magnetic properties were investigated by using vibrating sample magnetometer(VSM).Decreasing trends were observed for saturation magnetization(Ms),magnetic coercivity(Hc)and remanant magnetization(Mr)with the increase of Ni *** band gap(-2.70-2.79 eV)were calculated from diffuse reflectance data by using Kubelka–Munk function.

关键词： Sol-gel NiCuZn ferrite FTIR DC resistivity dielectric optical properties

An Overview on the Spinning Triangle Based Modifications of Ring Frame to Reduce the Staple Yarn Hairiness

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Journal of Textile Science and Technology 2020年第1期6卷 19-39页

作者： Md. Khalilur Rahman Khan Hosne ara begum Md. Razib Sheikh Department of Textile Engineering Bangladesh University of Business and Technology Dhaka Bangladesh Department of Yarn Engineering Bangladesh University of Textiles Dhaka Bangladesh

Traditional ring spinning system is associated with the several limitations, one of which is yarn hairiness. The awareness has been vibrantly growing among the spinning mills for reducing staple yarn hairiness because of its detrimental effects on the subsequent processes (i.e., weaving, knitting, dyeing etc.) and the quality of resultant textile products. As a result, modified form of ring frame has attracted a lot of attention among the researchers for making yarn with the lower level of hairiness value. Besides the raw material parameters and some processing variables, spinning triangle (ST) is the most critical region that has decisive influence on the distribution of fiber tensions and their spatial orientations and shapes in staple yarn body. Thus, using appropriate methods to control the spinning triangle geometry actively has been a vital issue in the field of yarn hairiness reduction. In this paper, it is attempted to make an overview on the spinning triangle based modifications of ring frame that have been designed and destined to reduce hairiness. However, agent aided ring spinning system has also been briefly discussed in this paper as well.

关键词： Ring Frame Compact Spinning Spinning Triangle Yarn Hairiness

Synthesis,structural investigation,dielectric and magnetic properties of Zn^(2+)-doped cobalt ferrite by the sol-gel technique

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Journal of Advanced Dielectrics 2018年第4期8卷 54-59页

作者： Mohammad Sajjad Hossain MdBadiul Alam Mohammad Shahjahan Most.Hosney ara begum MdMoazzem Hossain Suravi Islam Nazia Khatun Mukul Hossain Mohammad Saiful Alam Md.Al-Mamun Industrial Physics Division BCSIR Laboratories Dhaka BCSIRDhaka 1205Bangladesh Noakhali Science and Technology University Noakhali 3814 Bangladesh Daffodil International University Dhaka 1205 Bangladesh Atomic Energy Centre Dhaka Dhaka 1000 Bangladesh

Zinc substituted cobalt ferrite nanoparticles with elemental composition Co_(1-x)Zn_(x)Fe_(2)O_(4)(x=0.0,0.2,0.4,0.6)were prepared by the sol-gel auto-combustion technique using Co,Fe,Zn nitrate as a precursor where nitrates to citrate was 1:*** as prepared powder of cobalt zinc ferrite was sintered at 900○C for 3 ***,morphological,dielectric and magnetic properties were studied by x-ray diffractometer(XRD),scanning electron microscope(SEM),high precision impedance analyzer and vibrating sample magnetometer(VSM),*** peaks obtained from the XRD confirmed samples having crystallite(32–36 nm)single phase inverse spinel structure without any traceable *** parameters were calculated from XRD and it increases with Zn *** revealed irregularly shaped grains(-0.5–0.7μm)morphology with heterogeneous *** dielectric constant(ε′)and dielectric loss(tanδ),have been measured as a function of frequency at room *** dependence of ε′ and tan δ with frequency showed the normal dielectric behavior in accordance with the Maxwell-Wagner type of interfacial polarization and electron hopping change between Co^(2+)and Co^(3+)as well as between Fe^(2+)and Fe^(3+)ions at octahedral sites.

关键词： Solgel cobalt ferrite dielectric magnetic properties.

水稻丝氨酸棕榈酰转移酶的分子克隆、特征及其与褐飞虱抗性相关的基因表达（英文）

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浙江大学学报（农业与生命科学版） 2018年第3期44卷 365-372页

作者： begum Mahfuj ara 史肖肖白月亮蒋艳冬周文武毛存贵祝增荣浙江大学农业与生物技术学院昆虫科学研究所杭州310058 美国纽约州立大学石溪分校医学系和石溪癌症中心纽约11794

为研究鞘脂质和鞘脂质代谢前体长链基团(long-chain bases,LCBs)对胁迫应答的调控机制,对编码水稻丝氨酸棕榈酰转移酶(serine palmitoyltransferase,SPT)的LCB基因进行克隆。通过反转录聚合酶链式反应(reverse transcription-polymerase chain reaction,RT-PCR)扩增到3条LCB1和3条LCB2基因全长,蛋白质大小为481～497个氨基酸。生物信息学分析表明,LCB蛋白序列在细菌到人等多个物种中具有高度保守性。在褐飞虱(brown planthopper,BPH)的侵害作用下,水稻Os LCB2a1基因表达量上升。与其他水稻品种相比,抗性品种"Mudgo"和"IR64"中的基因表达量更高。基因表达量与褐飞虱危害指数呈负相关。在不同水稻品种的不同组织中,"IR64"叶片中的基因表达量显著升高,而"态平籼"叶鞘中的基因表达量显著升高。Os LCB2a1基因在抗褐飞虱水稻品种的最高分蘖期呈高表达,表明该基因可能在水稻营养期发挥作用。

关键词：鞘脂质代谢丝氨酸棕榈酰转移酶防御基因表达模式

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

Evaluation of Antibacterial and Antidiarrhoeal Activities of Feronia limoniaLeaf Extract

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American Journal of Plant Sciences 2013年第11期4卷 2181-2185页

作者： Mohammad Abdul Motalib Momin Mizanur Rahaman Khan Johir Rayhan Afrina Afrose Sohel Rana Anjuman ara begum Department of Pharmacy Jahangirnagar University Savar Ban-gladesh Department of Pharmacy University of Science and Technology Chittagong Chittagong Bangladesh

The present study was carried out to investigate possible antibacterial and antidiarrhoeal activities of ethanol extract of Feronia limonia leaves. Phytochemical analysis of the crude extract was performed to detect presence of different kinds of phytoconstituents. The antibacterial activity was investigated against four Gram positive and four Gram negative bacteria by using disc diffusion method. The plant extract showed moderate antibacterial activity against Gram positive bacteria namely Staphylococcus saprophyticus and Staphylococcus pyogenes and all tested Gram negative bacteria namely Escherichia coli, Shigella boydii, Shigella dysentery and Shigella flexneri in dose dependant manner. The results of castor oil-induced diarrhoeal study showed that Feronia limonia extract significantly reduced the severity & frequency of diarrhoea in mice at a higher dose of 500 mg/kg compared with the standard drug loperamide (25 mg/kg). The present study clearly supports the medicinal value of this plant. The overall results indicate the possibility of presence of some active principles in the plant extract possessing antibacterial and antidiarrhoeal actions.

关键词： Phytochemical Screening Antimicrobial Antidiarrhoeal Feronia limonia

Effect of sintering temperature on structural,magnetic,dielectric and optical properties of Ni-Mn-Zn ferrites

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Journal of Advanced Dielectrics 2021年第6期11卷 59-67页

作者： Nazia Khatun Mohammad Sajjad Hossain MostHosney ara begum Suravi Islam Nazmul Islam Tanvir Riyadh Hossen Bhuiyan Md.Al-Mamun Industrial Physics Division Bangladesh Council of Scientific and Industrial Research(BCSIR)Dhaka 1205Bangladesh Fiber and Polymer Division Bangladesh Council of Scientific and Industrial Research(BCSIR)Dhaka 1205Bangladesh Atomic Energy Centre(AEC) Dhaka 1000Bangladesh

Spinel ferrite Ni_(0.08)Mn_(0.90)Zn_(0.02)Fe_(2)O_(4)was prepared by a conventional ceramic process followed by sintering at three different temperatures(1050°C,1100°C and 1150°C).X-ray diffraction(XRD)investigations stated the single-phase cubic spinel structure and the FTIR spectra revealed two prominent bands within the wavenumber region from 600 cm^(−1)to 400 cm^(−1).Surface morphol-ogy showed highly crystalline grain development with sizes ranging from 0.27μm to 0.88μ*** magnetic hysteresis curve at ambient temperature revealed a significant effect of sintering temperature on both coercivity(Hc)and saturation magnetization(Ms).Temperature caused a decrease in DC electrical resistivity,while the electron transport increased,suggesting the semicon-ducting nature of all samples and that they well followed the Arrhenius law from which their activation energies were *** values of Curie temperature(Tc)and activation energy were influenced by the sintering ***-dependent dielectric behavior(100 Hz-1 MHz)was also analyzed,which may be interpreted by the Maxwell-Wagner-type *** UV-vis-NIR reflectance curve was analyzed to calculate the bandgap of ferrites,which showed a decreasing trend with increasing sintering temperature.

关键词： Ferrites ceramic technique FTIR dielectric constant hysteresis curve bandgap

Analysis of the Adsorption of Toxic Chromium (VI) by Untreated and Chitosan Treated Banana and Areca Fiber

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Journal of Textile Science and Technology 2020年第2期6卷 81-106页

作者： Hosne ara begum A. K. M. Monjurul Haque Md. Didarul Islam M. Mehedi Hasan Suza Ahmed Md. Razzak Ruhul Amin Khan Department of Yarn Engineering Bangladesh University of Textiles Dhaka Bangladesh Department of Applied Science & Chemical Engineering University of Dhaka Dhaka Bangladesh Department of Fabric Engineering Bangladesh University of Textiles Dhaka Bangladesh Institute of Radiation and Polymer Technology Bangladesh Atomic Energy Commission Dhaka Bangladesh

This paper work involves bunch experiments to investigate the effect of contact time, pH, and adsorbent dose on the extent of adsorption by bio-composites. Adsorption capacity of Chromium (VI) onto chitosan coated with banana and areca fiber was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH and adsorbent dose. The chitosan and fibers (banana and areca) were then cross-linked with glutaraldehyde to remove chromium [Cr (VI)] from water via static adsorption. It was found that optimum chromium absorption capacity of chitosan was assessed at pH of 2.5 to 4.5 and contact time of 30 to 180 minutes for raw banana and areca fiber and for chitosan treated banana & areca fiber. Though optimum adsorption of chromium of chitosan was measured 34.17 ppm (85.42%) from a 100 ml solution containing 40 parts per million (ppm) of Cr (VI) at 120 minutes, pH of 3.0 and 120 milligram (mg) adsorbent dose size, use of composite will be more favorable in the point of environmental concern as well as low cost because chitosan preparation is comparatively costly then banana and areca fiber. On the other hand, untreated banana and areca fiber optimum adsorption of chromium measured 3.65 ppm (9.1%) at 180 min and, pH of 4.5 and 140 mg adsorbent dose size and 3.76 ppm (9.4%) at 180 min, pH of 4.5 and 160 mg adsorbent dose size respectively. In case of chitosan treated banana fiber, it was observed that adsorption was increased from 17.664 to 30.057 (75.14%). On the other hand, for areca fiber with chitosan, it was observed that adsorption was increased from 21.664 to 30.156 (75.39%) ppm. The Langmuir and Freundlich adsorption models were used for the mathematical description of the adsorption of chromium ion onto composites and it was found that the Langmuir adsorption isotherm was more fitted models which mean that a monolayer adsorption surface was created. After analyzing from IBM SPSS 25 software, we got the stand

关键词： Adsorption Heavy Metal Chitosan Banana Fiber Areca Fiber Toxicity