Deposition and Characterization of p-Cu2O Thin Films

Corresponding Author : M. Rasadujjaman (rana1phyru@gmail.com)

Abstract :

In this work we have studied the p-type cuprous oxide (Cu2O) thin film fabricated with thermal oxidation and spray pyrolysis techniques. Cuprous oxide layer was prepared by thermal oxidation method inside a furnace in the temperature range of 930°C - 1010°C. X-ray diffraction studies revealed the formation of single phase cubic Cu2O films. The best quality Cu2O films were obtained at 970°C. The electrical resistivity of the Cu2O layer varies with the variation of temperature and found of the order…

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Effect of Mn Substitution on the Electric and Magnetic Properties of Nanocrystalline NiMnCu Ferrites

Corresponding Author : S. Nasrin (sharifa_labiba@yahoo.com)

Abstract :

 Nanosize powders of NiMnCu ferrites were prepared by combustion technique. The X-ray diffraction (XRD) patterns exhibited well defined single crystalline phase and formation of spinel structure. From the XRD data lattice constant was calculated. It is found that lattice constant increases with increase of Mn content, which indicates that the present compositions obey the Vegard’s law. It is also found that due to substitution of small amount of Mn average grain size, initial permeability, saturation magnetization and dielectric constant enhanced.…

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Elemental Status of Bangladeshi Tea using Instrumental Neutron Activation Analysis Method

Corresponding Author : M. Oyes Kurni (h.ahsan@sust.edu)

Abstract :

Elemental status of Bangladeshi tea was checked using nuclear reactor based Instrumental Neutron Activation Analysis (INAA) method. The analytical results of thirteen samples have been reported here. Irradiation of samples and standards were performed at the dry central thimble (DCT) facility of the 3.0 MW TRIGA Mark-II research reactor of AERE, Savar, Dhaka. The irradiated samples and standards were measured twice with different decay intervals depending on the half lives of the interested elements using High Purity Germanium (HPGe) detectors…

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Influence of Thickness on the Optical Properties of Vacuum Evaporated CdSe Thin Films

Corresponding Author : M. Hossain (rubi_2602@yahoo.com)

Abstract :

Cadmium Selenide (CdSe) thin films were deposited onto chemically and ultrasonically cleaned glass substrates by the thermal evaporation technique in high vacuum (∼10-5 mbar). The film thickness was varied from 50 to 250 nm keeping substrate temperature and rate of evaporation fixed at 1000C and 0.2-0.3 nm/sec, respectively. The thickness of the films was measured in situ by a frequency shift of quartz crystal (FTM5, UK). Dependence of the optical properties of the developed films on film thickness has been…

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Numerical Gaussian Array Approach to the Model of the Lattice Multi – Lobed Soliton in Photo-Refract

Corresponding Author : R. A. Jewel (yasmeen@sust.edu)

Abstract :

A numerical solution of the equations for multi–lobe soliton has been performed using a Gaussian array function. The linear and nonlinear parts of the index potential of the modulated periodic lattice is investigated numerically. Single–lobe and dipole solitons are formed with a family of small single solitons. The family soliton and solitons of the family are compared with numerical values for both the cases.  

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Preparation of Biodiesel from Castor Oil by Two-Step Method

Corresponding Author : Kaniz Ferdous (engr_kaniz@yahoo.com)

Abstract :

Current study reveals the production of biodiesel from non-edible oil such as castor oil (Ricinus Communis). Castor seed was collected from the local area of Sylhet region. Oil was extracted from seed by two different methods, Soxhlet extraction method and mechanical press method. Various properties of the raw oil were measured by standard methods. In the current study biodiesel was prepared from castor oil by two-step method due to higher Free Fatty Acid (FFA) content of raw oil. In two-step…

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Radiation Dose to Patients during Coronary Angiography and Percutaneous Transluminal Coronary Angiop

Corresponding Author : R. K. Khan (rezaul05@yahoo.co.in)

Abstract :

Coronary Angiography (CAG) and Percutaneous Transluminal Coronary Angioplasty (PTCA) procedures are now widely performed in different cardiac hospitals in Bangladesh. Patients undergoing CAG and PTCA procedures can be subjected to large radiation dose. Two catheterization laboratories in Square Hospital, Dhaka were chosen to measure the radiation dose of patients by Thermoluminiscence Dosimeter (TLD) chips. A total of calibrated 96 TLD chips packed in a polythene sheet were used for the measurement of effective dose of the patient. Patients went through…

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Radioactivity and Radiological Risk of the Wastes Generated from the Fertilizer Factories of Banglad

Corresponding Author : M. A. Samad (sdphy71@yahoo.com)

Abstract :

Fertilizer industries, specifically the phosphate fertilizer industries, are important sources of exposure to ionizing radiation of the people and possible contamination of the environment as phosphate fertilizers contain radionuclides of 238U, 232Th decay series as well as radioisotopes of 40K. The activity concentrations of 226Ra, 232Th and 40K were determined in solid and liquid waste samples collected from the six fertilizer (urea and phosphate) factories of Bangladesh. Eight different types of samples were collected, processed and then analyzed by gamma…

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Silicon-based Multi-junction Solar Cell

Corresponding Author : G. A. Lita (gulshanaralita@gmail.com)

Abstract :

Thin film of hydrogenated amorphous silicon based (a-si:H) alloys have attracted the considerable interest now a days because of their potential application as photovoltaic material. The present status of this material and its application to photovoltaic devices (designing solar cells technology) have been studied. The multijunction or Tandem solar cell [TCO/p-i-n/p-i-n/TCO] fabricated by plasma enhanced chemical vapor deposition technique (PECVDT) / Glow-discharge Technique. It is essential to characterize solar cell to study the performance for further improvement. So I-V (current-voltage)…

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Study of Human Milk in Terms of Sampling Time and Age of the Lactating Mothers

Corresponding Author : R Khatun (rajada_75@yahoo.com)

Abstract :

 Human milk is the most important common food of babies during the early years of their life all over the world. The study has been carried out in order to investigate whether the human milk varies with sampling time and age group of the sample providing lactating mothers. Certain toxic elements including Cd, Hg, Pb, etc. were also the special interest, because of their negative role in enhancing infant mortality rates. The experiments have been done with the 3 MV…

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Study on the Physical Properties of Jute-Cotton Blended Rotor Yarn

Corresponding Author : Md. Abdus Shahid (te_shahid@yahoo.com)

Abstract :

This work reports the successful outcome of attempts to manufacture 30, 40, 50, 60, 80 tex rotor spun yarn using modified jute with cotton fibers blending at 2o:80 ratio. The present paper is concerned with the effect of rotor variables such as opening roller speed, rotor speed and yarn linear density on the properties of jute-cotton blended yarn. The results show that yarn tenacity and elongation% at break increases with the increase in opening roller speed up to 8700 rpm…

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The Influence of Indian Ocean Warming and Soil Moisture Change on the Asian Summer Monsoon

Corresponding Author : Tanvir Ahmed (tanvir_sust@yahoo.com)

Abstract :

 An Atmospheric General Circulation Model (AGCM) is used to examine the influence of Indian Ocean warming and soil moisture change on the Asian summer monsoon. Three numerical experiments have been done for this purpose. The first one is related to the positive Sea Surface Temperature (SST) anomaly related to global warming and its effect on the Asian summer monsoon. The last two are related to the change of soil moisture and its impact on Asian summer monsoon. It has been…

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Transport Behavior and Low Field Magnetoresistance of Polycrystalline La0.63Y0.07Sr0.30MnO3 and La0.

Corresponding Author : M. Nahar (fahimdu@gmail.com)

Abstract :

Polycrystalline manganites of nominal chemical compositions La0.63Y0.07Sr0.30MnO3 and La0.63Y0.07Ba0.30MnO3 sintered at 1673K were investigated to observe transport properties and low field magnetoresistance (MR). XRD measurements confirmed formation of single phase pseudocubic perovskite structure. The temperature dependent DC transport properties showed a metalsemiconductor transition. A giant negative magnetoresistance (GMR) effect is observed at transition temperature in presence of magnetic field; which is mainly attributed to the intrinsic properties of grains and random fluctuation of electron-phonon spin interaction due to phase transition.…

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