Chittagong University Campus : Rich in Forest Growing Stock of Valuable Timber Tree Species in Bangladesh

Salena Akter,Md. Siddiqur Rahman,M. Al-Amin 강원대학교 산림과학연구소 2013 Journal of Forest Science Vol.29 No.2

The campus of Chittagong University in Bangladesh is rich in forest ecosystem. The campus has large area with vast tract of land planted with valuable timber tree species. The present study identifies and discovers the potential growing stock of the plantations in the campus area. This Growing stock was measured in three parameters viz. volume, biomass and organic carbon stock. Study identified thirty three economically valuable forest tree species in the plantations of Chittagong University. Out of three growing stock parameters, volume of timber was found to be low in indigenous tree species in the plantation sites other than exotic species. This might be due to their slow growth rate and low density in the plantation sites. However, biomass and organic carbon stock of trees per hactre area showed that indigenous species gather and sequester more timber and carbon respectively than introduced species. Plantations of Chittagong University campus can acquire 25.51 m3/ha volume of economically important tree species, where biomass and organic carbon stock is 222.33 tonne/ha and 107.48 tonne/ha respectively. This result shows a positive impression on the plantation site to be considered as good forest reserve.

Terahertz emission in quantum dots by sum frequency generation

M. Abdullah,Farah T. Mohammed Noori,Amin H. Al-Khursan 한국물리학회 2016 Current Applied Physics Vol.16 No.7

The second-order nonlinear susceptibility (SONS) in self-assembled InAs quantum dots (QDs), in the form of quantum disks, under applied electric field was studied. Using Feynman diagram, the relation of SONS for sum frequency generation was stated. Two cases were studied, which are the interband (IB) and intersubband (ISB) transitions with the consideration of the QD inhomogeneity, which is shown to be important in SONS calculations. For the ISB case, a resonance near 92 mm was predicted, which is important for infrared applications. Energy subbands and momentum matrix elements are shown as the main factors controlling SONS. It was found that adding some detuning to the pump will extend the wavelength by 45 mm which might applicable for Terahertz (THz) applications. Double resonance was shown to blue shifts the wavelength.

Effects of sintering temperature and zirconia content on the mechanical and microstructural properties of MgO, TiO2 and CeO2 doped alumina–zirconia (ZTA) ceramic

Al-Amin Md.,Mumu Homayra Tabassum,Sarker Saugata,Alam Md. Zahangir,Gafur M. A. 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.1

The effects of sintering temperature and ZrO2 addition on the hardness and fracture toughness of zirconia toughened alumina (ZTA)–MgO–TiO2 composite was investigated. 5 wt.% CeO2 was added to ZTA containing 5 wt.% of MgO and 5 wt.% of TiO2. Two sets of composition A5ZMTC and A15ZMTC were used consisting of 5 wt.% and 15 wt.% of 3YSZ, respectively, to analyze the effect of CeO2 on the base composition. The powders were pressed into pellets and sintered at different temperatures of 1450 °C, 1500 °C, 1600 °C and 1650 °C for 3 h. Density, hardness and fracture toughness increased to a maximum value and then decreased. From the XRD analysis, Ce0.7Zr0.3O2 in only A5ZMTC and CeAl11O18 in only A15ZMTC are evident. The highest fracture toughness of 12.03 MPam1/2 (Casellas) was achieved at 1500 °C in A15ZMTC and maximum hardness of 14.15 GPa was obtained in A5ZMTC sintered at 1450 °C.

Customer's Attitude toward Mobile Banking Usage: A Case Study in Bangladesh

AL AMIN, Md.,SULTANA, Nahida,SAHA, Trina,ISLAM, S.M. Nazrul,KASHEM, Md. Abul 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.2

Mobile banking brings about a progressive change in the field of banking sectors in Bangladesh. To create a sustainable banking environment, technological implementation is important. As a part of this, many organizations as well as modern banks propelled mobile banking systems in Bangladesh. The customers' attitudes towards mobile banking are fascinating in Bangladesh. So, it is important for mobile banking authority to know what factors influence customers' positive attitude towards mobile banking usage and whether they are facing problems in using mobile banking. To evaluate the customers' attitude toward mobile banking usage in Bangladesh is the main objective of this study. People who use mobile banking have been considered for the study. Respondents were reached out based on their online activities. Around 400 questionnaires have been sent to respondents, but only 200 were returned with responses. A quantitative research design was used for this study. As regards statistical analysis tools, descriptive statistics, factor analysis, and regression analysis have been adopted for analyzing the research study. The results revealed that usage benefits, shopping benefits, and psychological factors influence customers' positive attitude toward mobile banking usage in Bangladesh. Besides, some problems with mobile banking usage are identified by the respondents.

Population dynamic parameters and stock status of kingfish (Scomberomorus commerson) in the waters of sultanate of Oman

Usama Al-Adawi,S. M. Nurul Amin 한국수산과학회 양식분과 2020 한국수산과학회 양식분과 학술대회 Vol.2020 No.7

High-Performance Implementation of Power Components on FPGA Platform

Jarrah Amin,Haymoor Zaid Sari,Al-Masri Hussein M. K.,Almomany Abedalmuhdi 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

Recently, the utility electric grid has been facing many problems in power quality because of using power electronic devices for controlling most of the Alternating Current and Direct Current loads. Solving the issue of reactive power at the end-user side became more challenging because of the sudden changes in loads considering harmonics. This leads to many reactive power compensation system failures due to the use of mechanical switching mechanisms which became useless in front of those sudden changes because of harmonics. In this paper, a solution is proposed to solve the aforementioned constraints. Moreover, a high-speed computation platform or fi eld programmable gate array (FPGA) is used to measure and calculate voltages, currents, harmonic components, total harmonic distortion, active and reactive electrical power depending on distortion and displacement factors. The Xilinx Vivado high-level synthesis tool is used to implement the created design on the targeted FPGA device. The proposed approach can be used to determine the required design specifi cation of the hardware that is suitable for real-time applications of any electric power analyzer that uses FPGA boards along with the proposed optimization algorithms. Experimental results validate the advantages of the proposed optimizing approach with approximately up to 15 folds of improvements when it is compared to a regular non-optimized design.

Proapoptotic and Antimetastatic Properties of Supercritical CO2 Extract of Nigella sativa Linn. Against Breast Cancer Cells

Hussein M. Baharetha,Zeyad D. Nassar,Abdalrahim F. Aisha,Mohamed B. Khadeer Ahamed,Foaud Saleih R. Al-Suede,Mohd Omar Abd Kadir,Zhari Ismail,Amin Malik Shah Abdul Majid 한국식품영양과학회 2013 Journal of medicinal food Vol.16 No.12

Nigella sativa, commonly referred as black cumin, is a popular spice that has been used since the ancient Egyptians. It has traditionally been used for treatment of various human ailments ranging from fever to intestinal disturbances to cancer. This study investigated the apoptotic, antimetastatic, and anticancer activities of supercritical carbon dioxide (SCCO2) extracts of the seeds of N. sativa Linn. against estrogen-dependent human breast cancer cells (MCF-7). Twelve extracts were prepared from N. sativa seeds using the SC-CO2 extraction method by varying pressure and temperature. Extracts were analyzed using FTIR and UV-Vis spectrometry. Cytotoxicity of the extracts was evaluated on various human cancer and normal cell lines. Of the 12 extracts, 1 extract (A3) that was prepared at 60C and 2500 psi (*17.24 MPa) showed selective antiproliferative activity against MCF-7 cells with an IC50 of 53.34 – 2.15 lg/mL. Induction of apoptosis was confirmed by evaluating caspases activities and observing the cells under a scanning electron microscope. In vitro antimetastatic properties of A3 were investigated by colony formation, cell migration, and cell invasion assays. The elevated levels of caspases in A3 treated MCF-7 cells suggest that A3 is proapoptotic. Further nuclear condensation and fragmentation studies confirmed that A3 induces cytotoxicity through the apoptosis pathway. A3 also demonstrated remarkable inhibition in migration and invasion assays of MCF-7 cells at subcytotoxic concentrations. Thus, this study highlights the therapeutic potentials of SC-CO2 extract of N. sativa in targeting breast cancer.

Agency, empowerment and intra-household gender relations in Bangladesh: Does market-oriented microcredit contribute?

Md. Al-Amin,Golam M. Mathbor 이화여자대학교 아시아여성학센터 2019 Asian Journal of Women's Studies(AJWS) Vol.25 No.2

This article seeks to probe the influence of microcredit on the development of agency and empowerment of poor women in rural Bangladesh. The study was conducted on the clients of two leading NGOs—Grameen Bank (GB) and Bangladesh Rural Advancement Committee (BRAC)—in Bangladesh. The qualitative findings of the ethnographic study confirmed that poor women’s involvement in microcredit programs does not contribute to the development of their agency and empowerment in a transformative sense due to structural problems in the programs and the patriarchal social structure of Bangladesh. It is true that microcredit has increased the mobility of women through group networks and organizations, but it has not added to their broader empowerment by easing their access to market transactions, unlike their male counterparts. An overwhelming majority of women do not have control over loans and credit-driven activities, although repayment responsibility rests entirely with them. In some instances, microcredit leads to spousal conflicts regarding repayments. Therefore, microcredit has not been very effective in promoting rational economic choices by women that would lead to their empowerment in the true sense of the term.

The Influence of Optical Porosity of Tree Windbreaks on Windward Wind Speed, Erosive Force and Sand Deposition

Dafa-Alla M.D.,Nawal K.N. Al-Amin 강원대학교 산림과학연구소 2016 Journal of Forest Science Vol.32 No.2

The research was conducted windward of an irrigated Acacia amplicips Maslin windbreak established to protect As Salam Cement Plant from winds and moving sands. Two belts with approximate optical porosities of 50% and 20% were studied in River Nile State, Sudan. The research aimed at assessing the efficiency of the two belts in wind speed reduction and sand deposition. Research methods included: (i) estimation of optical porosity, (ii) measurements of windward wind speeds at a control and at distances of 0.5 h (h stands for windbreak height), 1 h and 2 h at two vertical levels of 0.25 h and 0.5 h, (iii) estimation of relative wind speeds at the three positions (distance and height) at windward and (iv) estimation of wind erosive forces and prediction of zones of sand deposition. Results show that while the two belts reduced windward wind speeds at the two levels for the three distances, belt II was more effective. Nearest sand deposition occurred at 2 h and 1h windward of belt II and belt I, respectively, at level 0.25 h. At level 0.5 h, sand was deposited only at 2 h windward of belt II and no sand deposition occurred windward of belt I. The study concludes that less porous windbreaks are more effective in reducing wind speed and in depositing sand in windward direction at a distance of not less than twice the belt height.

Synthesis and analysis of the influence of Eu3+ on the structural, ferromagnetic, dielectric and conductive characteristics of Ni0.4Zn0.45Cu0.15Fe(2-x)EuxO4 composites using conventional double sintering ceramic method

I. N. Esha,Md. Al-Amin,F. T. Z. Toma,Enayet Hossain,M. N. I. Khan,Kazi Hanium Maria 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.5

Conventional double sintering ceramic method has been followed to prepare a series of Eu substituted Ni0.4Zn0.45Cu0.15Fe(2-x) EuxO4 (NZCFEO) ferrites with x = 0.00, 0.02, 0.04, 0.07, 0.10, 0.12, 0.15. X-ray diffraction peaks confirm the single phase cubic spinel structures of all the samples. The lattice parameter is found to be distorted with the addition of Eu into the samples. X-ray density and bulk density increase with the increase of Eu content. Better crystallization has been obtained with the decreasing porosity as a result of increasing Eu3+ concentration. The dielectric constant of the samples shows a decreasing trend while both AC and DC resistivities are observed to increase with the increase of Eu3+ concentration. The high resistivity offers greater value of the activation energy. Permeability is found to decrease with increasing Eu content. Saturation magnetization changed significantly with Eu3+ concentration. Noteworthy decrease of the Curie temperature is observed with the addition of Eu substituent.