Md. Mostafizur Rahman

Improvement of Physico-Mechanical Properties of Radiation-Vulcanised Natural Rubber Latex Films by Adding Urea

The role of urea as an additive on the physico-mechanical properties of radiation vulcanised natural rubber latex (RVNRL) films was investigated. RVNRL films were prepared by the addition of urea with the concentration range 0–1.0 phr (parts per hundred rubber) and irradiated with various radiation doses (0–20 kGy). The concentration of urea and radiation doses were optimised and found to be 0.5 phr urea and 12 kGy radiation dose. Tensile strength, tear strength and cross-linking density of the rubber films increased with increasing the concentration of urea as well as radiation doses. The tensile and tear strengths of the films enhanced by 39 and 41%, respectively, at the optimum conditions. Elongation at break, permanent set and swelling ratio of the films decreased with increasing urea concentration and radiation doses until they attained approximately constant values.

Synthesis of the first sulphur-containing platinum(II) alkenylarylalkynyl complexes by photoirradiation

A new synthetic route has been developed to construct a new series of sulphur-containing trans-platinum(II) alkenylarylalkynyl complexes with general formula trans-[(PR3)2–Pt–{CC–Ar–CHCH(SPh)}2], (where R = ethyl and Ar = phenylene 2a, biphenylene 2b, 2,5-dimethylphenylene 2c, and 2,5-dimethoxyphenylene 2d), having one phenylthio moiety in each alkenyl backbone. Reaction of the diterminal alkynyl areneacetylide of the trans-platinum(II) complex with benzenethiol in chloroform, upon photoirradiation, readily affords the trans-platinum(II) alkenylarylacetylides in good to excellent yields with good regioselectivity. The absorption and photoluminescence spectra indicated that the emission was exhibited in the range 399–425 nm depending on the nature of the acetylide ligand bound to the central metal platinum.

Application of Remote Sensing Technology for Calibration of Bay of Bengal Morphology Model

Prior to implication of mathematical model as a tool for any kind of policy making or decision making, the model must be calibrated against appropriate observed data. The two-dimensional sediment transport model of the Bay of Bengal usually being calibrated against suspended sediment concentration at different locations comparing the model results with field measurements to make the model performance to a satisfactory level. Since field data of sediment concentration is rarely available for model calibration, an attempt has been made in the present study, to generate sediment concentration data by using satellite images to calibrate the sediment transport model in a better way. Calibration of sediment transport model result against image generated sediment concentration at different locations of Bay of Bengal show acceptable agreement.

Safety Sign, Symbols And Road Markings Of 'Planned Residential Areas With Adjacent Highways' Of Dhaka City: Focusing Pedestrian Safety

Demand of safety roads is a movement now-a-days, as numbers of accidents are increasing day by day, because of increasing number of vehicles and side by side, increasing of unskilled drivers to fulfill the necessary demand of the increased motorization. Beside all these, lack of proper safety signs, symbols and road markings are some of the major reasons behind these unwanted accidents Studies are required to investigate the present situation of these signs and symbols in terms of public safety. For this purpose this study will be focused on the present context of safety signs, symbols and road markings in some of the planned residential areas of Dhaka city, with adjacent highway. The focus of this paper is to see the present situation of safety signs, symbols and road markings, whether they are sufficient in terms of safety. Going through the standards will further justify the present situation in terms of public safety and the accidents that may take place due to the present situation. The investigation shows that, there are some lacks at new airport road, while the condition of safety sign, symbols and road markings are well maintained at Mohakhali DOHS. In Mohammadpur, safety signs and symbols are way ahead than Uttara model town.