The Chittagong University Journal of Science 2020-08-05T10:03:30+00:00 Professor Dr. M. Jamaluddin Ahmed, FRS Open Journal Systems <p>Published by the University of Chittagong, Chittagong. Full-text articles available.</p> <p><img src="/public/site/images/admin/[JOPSOM].png"><br>Articles in the <em>Chittagong University Journal of Science</em> are Open Access articles published under the Creative Commons CC BY-NC License <a href="">Attribution-NonCommercial 4.0 International (CC BY-NC 4.0).</a></p> Measures Resolving Potential Risks to Successful Implementation of REDD+ in Bangladesh 2020-08-05T10:00:41+00:00 Md Danesh Miah Suman Chandra Paul <p>REDD+ implementation and its governance is needed in Bangladesh for resource management, conservation and enrichment of natural forests. REDD+ can generate both carbon and non-carbon benefits to the forest dependent people. On the contrary, good forest governance leads the transparency and accountability in the forest sector. The study was conducted with a view to find out the necessary measures for effective REDD+ implementation in Bangladesh. To realize the objectives, online survey, Focus Group Discussion (FGD) and Key Informants‟ Interview (KII) were used. The study was conducted in Rangamati, Modhupur, and Sreemongal for FGD and KII interviews. For online survey, professional version of „Survey Monkey‟ online software were used. The study found that capacity building for implementation of laws and regulations, strong policy, political influence on right tract, strengthen and empower civil society‟s capacity etc. are the possible resolving measures on REDD+ implementation. Promoting public awareness on laws and regulations, strengthening law enforcement in the forest sector, and successful implementation of policies had been revealed to increase the effectiveness and integrity for the implementation of REDD+ in Bangladesh.</p> <p>The Chittagong Univ. J. Sci. 40(1) : 1-20, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## Greenhouse Gas Emissions from Municipal Solid Waste Management of the Chittagong City Corporation 2020-08-05T10:01:41+00:00 Md Danesh Miah M Abubokor Siddik <p>Municipal solid waste (MSW) management has an impact on climate generating greenhouse gases (GHG). To quantify GHG emission from MSW management activities (transportation, composting, recycling and landfill), this study was conducted in the Chittagong City Corporation (CCC). Data were collected about detail MSW management activities of the CCC through conducting a structured questionnaire survey on related personnel with MSW management. To collect data about recycling, another questionnaire survey was conducted on all junkshops near to both dumping sites (Anandabazar and Arefin Nogor) of the CCC. The study found that, composting and recycling of MSW have a positive contribution in reducing GHG emission. Transportation and land-filling of MSW have a contribution in GHG emission. The amount of GHG emission from the existing MSW management system of the CCC is 31,904.68 tons of CO<sub>2</sub>-eq per month. The life cycle assessment (LCA) study on composting shows that, the reduction of GHG emission is 3.66 tons of CO<sub>2</sub>-eq per ton of produced compost. The study finding is expected to contribute to the field of climate change mitigation in Bangladesh.</p> <p>The Chittagong Univ. J. Sci. 40(1) : 21-46, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## Comparative Studies of Dose Measurements in Cornea and Mantle Shielding Block for High Energy Gamma Radiation (<sup>60</sup>Co) in Radiotherapy Treatment 2020-08-05T10:01:45+00:00 M Shamsuzzaman MS Rahman Debasish Paul M Jahangir Alam Shyamal Ranjan Chakraborty <p>Cornea and Mantle shielding blocks were used to evaluate the dosimetry features of blocked beam radiotherapy. These blocks were used to produce the blocked beams for 5×5 cm<sup>2</sup> and 30×30 cm<sup>2</sup> field sizes. Doses were measured and calculated by the Clarkson's method and compared mutually. The variations of 0.05%, 0.92% and 0.99% were observed at three dose investigation points of 5×5 cm<sup>2</sup> field size for cornea block. For mantle block the variation between measured and calculated values were found to be 1.97%, 2.46%, 2.39%, 2.13%, 2.00% and 1.93% at six dose investigation points of 30×30 cm<sup>2</sup> field size. In this study dose calculated by the empirical relation using correction factors C<sup>i</sup><sub>jxK </sub>and CF<sub>i </sub>were found approximately equal to the experimental value. In the cases of both cornea and mantle shielding the calculated mean value of uncertainty in dose measurement between calculated dose values of Clarkson’s method and empirical relation was found satisfactorily to be within ±5.0%, fulfilling to the International Commission on Radiation Units and Measurements (ICRU) [1].</p> <p>The Chittagong Univ. J. Sci. 40(1) : 47-58, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## Stochastic Inventory Model with Reworks 2020-08-05T10:02:58+00:00 Mohammad Ekramol Islam M Sharif Uddin - Mohammad Ataullah Ganesh Chandra Ray <p>In most of the inventory models, a single stock is considered from where items are served for the customers. In this paper, two stocks are considered. One is for fresh items and another is for returned items. The model is more appropriate where warranties are provided for a fixed time duration. Moreover, inventory which are kept to the stock may not have finite shelf-life is also considered here such as milk, meat, vegetables, radioactive materials, volatile liquids. In this current model, we considered the inventory is decayed in a constant rate θ. It is assumed that inventory level for both the fresh and returned items are pre-determined. When inventory level reaches at s, a replenishment takes place with parameter ϒ The demands that arrive for fresh items and returned items follow Poisson process with parameter λ &amp; δ respectively. Service will be provided with Poisson process for returned items with parameter μ. The joint probability distribution for inventory level of returned items and for fresh items is obtained in the steady state analysis. Some systems characteristics of the model are derived and the results are illustrated with the help of numerical examples.</p> <p>The Chittagong Univ. J. Sci. 40(1) : 59-74, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## Effect of Fukushima Accident on Fishes and Fish Like other Foods Collected from the Bay of Bengal and Karnaphuli River, Bangladesh 2020-08-05T10:03:05+00:00 Akhi Das Gupta Md Kowsar Alam Shyamal Ranjan Chakraborty AKM Rezaur Rahman SI Bhuian Masud Kamal Hasan Murad Arun Kumar Deb <p>An experiment was carried out to assess the radiological exposure due to the intake of fishes and fish like foods from some common estuary (Karnaphuli River) and Marine (Bay of Bengal) contaminated by Fukushima Reactor Accident, if any, by using gamma spectroscopy. The analysis was done to estimate the radioactivity concentrations due to natural radionuclides namely <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K and artificial radionuclide <sup>137</sup>Cs in Karnaphuli estuary and Chittagong city adjoining Bay of Bengal fish and fish-like samples. The activity concentration for <sup>238</sup>U in all the samples ranged from 0.10615 ± 0.0000 to 2.4767 ± 0.0005<sup>-1</sup> with the mean of 0.6109 ± 0.0001<sup>-1</sup>. The Activity of <sup>232</sup>Th ranged from 0.0009 ± 0.0000 to 0.0273 ± 0.0000<sup>-1</sup> with the mean of 0.0074 ± 0.0000<sup>-1</sup>. The activity concentration for <sup>40</sup>K was found to be in the range from 1.5516 ± 0.0311 to 74.8658 ± 0.2532<sup>-1</sup> with the mean of 24.9533 ± 0.0702<sup>-1</sup>. The artificial radionuclide <sup>137</sup>Cs was not found in any of the samples. The specific activity values for most of the sample were within the permissible limits. The average effective dose and internal hazard index due to consumption of those fishes and fish-like foods was found to be 0.1 mSv.y<sup>-1</sup> and 0.0085 ± 0.0000 mSv.y<sup>-1</sup> respectively. The research work showed that the consumers of concerned fishes and fish-like foods of the Chittagong area have no risk of radioactivity ingestion even though no amount of radiation is assumed to be totally safe.</p> <p>The Chittagong Univ. J. Sci. 40(1) : 75-96, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## Molar Interactions of Some Aromatic Hydrocarbons in n-Heptane by Viscometric Measurements at 298.15K 2020-08-05T10:03:13+00:00 Md Kamrul Hossain M Abdur Rahaman Shamim Akhtar <p>The viscosities, η , of pure n-heptane, toluene, o-xylene, mesitylene, and some of their binary mixtures covering the whole composition range have been measured at 298.15K. Deviations in viscosity, ∆η , was calculated using experimental results. The concentration dependencies of η were correlated to polynomial expressions, whereas, ∆η were fitted to the Redlich–Kister equation. Moreover, the values of the excess Gibbs free energy of activation, ∆G<sup>#E</sup>, of these mixtures were determined. Viscosity measurements of the binary systems were correlated with Grunberg and Nissan the three-body and four-body McAllister expressions. In all systems, ∆η were found to be negative in the whole range of composition with a single lobe having minimum at 0.6 mple fraction of aromatic hydrocarbon. While dispersive forces are suggested to dominate in n-heptane + toluene, for the other two systems &nbsp;‘favourable geometric fitting’ overpowers them due to the increasing number of&nbsp; – CH<sub>3</sub> groups in the relevant aromatic hydrocarbons.</p> <p>The Chittagong Univ. J. Sci. 40 : 97-110, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## Effect of Fukushima Accident on Tourists Based Coastal Belts of Chittagong City, Bangladesh 2020-08-05T10:03:15+00:00 Hasan Murad Md Kowsar Alam Shyamal Ranjan Chakraborty AKM Rezaur Rahman SI Bhuian Masud Kamal Akhi Das Gupta Arun Kumar Deb <p>This research work was aimed to obtain the radioactive exposure of naturally occurring and anthropogenic radioactive materials in sediment samples from the coastal belts of Chittagong city due to the Fukushima nuclear accident. The activity concentration, absorbed outdoor and indoor dose rates, annual effective dose rates and the radiation hazard indices from these samples were calculated. The correlation coefficient and Chi-square value per degree of freedom were also determined. A strong correlation between radium equivalent activity and activity of <sup>232</sup>Th was obtained in the Bay of Bengal. However, a very poor correlation was observed for radium equivalent activity and activity of <sup>40</sup>K in both the study areas. The Chi-square value per degree of freedom <strong>(</strong><strong>χ</strong><strong><sup>2</sup></strong><strong><sub>R</sub></strong><strong>) </strong>for <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K were respectively 70.244, 77.168 and 1.87 for the Karnaphuli River samples and 38.091, 62.023 and 2.06 for the Bay of Bengal samples. No artificial radionuclide was detected in the samples measured from the study areas. No radiation threat level is obtained on the study areas due to the nuclear explosion at Fukushima.</p> <p>The Chittagong Univ. J. Sci. 40 : 111-136, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## An Alternative Method of Construction and Analysis of Asymmetrical Factorial Experiment of the type 6x2<sup>2</sup> in Blocks of Size 12 2020-08-05T10:03:19+00:00 Dipa Rani Das Sanjib Ghosh <p>This paper focuses on the construction and analysis of an extra ordinary type of asymmetrical factorial experiment which corresponds to fraction of a symmetrical factorial experiment as indicated by Das (1960). For constructing this design, we have used 3 choices and for each choice we have used 5 different cases. Finding the block contents for each case we have seen that there are mainly two different cases for each choice. In case of analysis of variance, we have seen that, for the case where the highest order interaction effect is confounded in 4 replications, the loss of information is same for all the choices. Again for the case where the highest order interaction effect is confounded in 3 replications, the loss of information is also same for all the choices and one effect which is confounded due to fractionation has the same loss of information for all the choices.</p> <p>The Chittagong Univ. J. Sci. 40 : 137-150, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement## Bayes Estimation under Conjugate Prior for the Case of Laplace Double Exponential Distribution 2020-08-05T10:03:30+00:00 Md Habibur Rahman MK Roy <p>The Bayesian estimation approach is a non-classical device in the estimation part of statistical inference which is very useful in real world situation. The main objective of this paper is to study the Bayes estimators of the parameter of Laplace double exponential distribution. In Bayesian estimation loss function, prior distribution and posterior distribution are the most important ingredients. In real life we try to minimize the loss and want to know some prior information about the problem to solve it accurately. The well known conjugate priors are considered for finding the Bayes estimator. In our study we have used different symmetric and asymmetric loss functions such as squared error loss function, quadratic loss function, modified linear exponential (MLINEX) loss function and non-linear exponential (NLINEX) loss function. The performance of the obtained estimators for different types of loss functions are then compared among themselves as well as with the classical maximum likelihood estimator (MLE). Mean Square Error (MSE) of the estimators are also computed and presented in graphs.</p> <p>The Chittagong Univ. J. Sci. 40 : 151-168, 2018</p> 2018-06-28T00:00:00+00:00 ##submission.copyrightStatement##