Chittagong University of Engineering & Technology

About: Chittagong University of Engineering & Technology is a education organization based out in Chittagong, Bangladesh. It is known for research contribution in the topics: Computer science & Renewable energy. The organization has 1200 authors who have published 1444 publications receiving 10418 citations. The organization is also known as: Engineering College, Chittagong & Bangladesh Institute of Technology, Chittagong.

Slow arsenic poisoning of the contaminated groundwater users

Abstract: This paper gives impact of Arsenic contaminated water on human health as well as overview of the extent and severity of groundwater arsenic contamination in Bangladesh. Scalp hair is the most important part of the human body to monitor the accumulation of this type of poison. Therefore, an experiment has been carried out by Neutron Activation Analysis (NAA) at Atomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh on human hair of corresponding tube well water users of these areas to determine the total accumulation of arsenic to their body. Hair samples collected from the region where the groundwater was found highly contaminated with arsenic. The obtained results of arsenic concentration in the lower age (Hb) categories of users (below 12 years of age users) is in the range of 0.33 to 3.29 /gmg/g (ppm) and that in the Hu categories (upper 12 years of age users) is 0.47 to 6.64 μg/g (ppm). Where as maximum permissible range is 1 ppm certified from WHO. Results show that the peoples are highly affected where the groundwater is highly contaminated with arsenic and acts as the primary source of arsenic poisoning among the peoples of those areas. The results indicate that human population is affected with arsenic locally using the contaminated water for a long time.

Spatial distribution of radionuclides in agricultural soil in the vicinity of a coal-fired brick kiln

Abstract: The spatial distributions of naturally occurring radionuclides (226Ra, 232Th, and 40K) in agricultural soils collected in the proximity of a coal-fired brick kiln located at Chittagong district were studied using HPGe γ-ray spectrometry. The obtained mean activity concentrations for 226Ra, 232Th, and 40K were slightly higher than the world average values, which indicate the contribution of radionuclides via the fly ash deposition from the kiln. The maximum activity concentrations of 226Ra, 232Th, and 40K in soil samples collected at a distance of 120 m from the kiln were found to be 54.3 ± 11.3 Bq kg−1, 62.1 ± 18.2 Bq kg−1, and 572 ± 123 Bq kg−1, respectively; the levels show further decreasing trend in all directions (towards and away from the kiln). Associated radiological hazard indices were calculated in order to assess the radiation effects to human health and compared with the world-recommended values. Basic multivariate statistical analysis was performed to describe the statistical characteristics of the radionuclides. Lower values of radiological indices indicate that there is no probability of immediate health effect on workers and public living around the kiln due to the presence of natural radioactivity in the agricultural soils.

Discharge‐based economic valuation of irrigation water: Evidence from the Teesta River, Bangladesh

Abstract: L'estimation de la valeur d'usage de l'eau d'une riviere en fonction du debit utilise reste rare dans la litterature, alors que ce type d'evaluation peut revetir une grande importance pour informer l'allocation de la ressource entre usages au-fil-de-l'eau (in-stream) et hors-riviere (off-stream). Cet article developpe et presente les benefices totaux et marginaux d'un usage hors-riviere, l'irrigation, comme fonctions du debit de la riviere Teesta au Bangladesh. Une approche de bilan de l'eau au champ, et la modelisation avec CROPWAT sont utilises pour calculer respectivement les besoins en eau du riz, et d'autres cultures. La methode d'imputation residuelle est employee pour estimer la valeur economique de l'eau d'irrigation. Pour les cas de faible debit dans la riviere, divers scenarios sont testes, bases sur (i) l'usage conjoint de ressources souterraines, (ii) la reduction des surfaces irriguees, et (iii) des pertes de rendements lies au stress hydrique ; ils permettent de developper les fonctions de benefices totaux et marginaux pour les usages en irrigation dans la zone d'etude. Les benefices marginaux estimes selon le debit de la riviere forment des fonctions lineaires, de pente nulle dans les deux premiers scenarios, et de pente negative dans le troisieme. Les resultats obtenus peuvent assister les gestionnaires de bassin dans les decisions d'allocation equitable et efficiente de la ressource entre usages. (Resume d'auteur)

Neural network based recognition of speech using MFCC features

Abstract: Analysis and detection of human voice at workplace such as telecommunications, military scenarios, medical scenarios, and law enforcement is important in assessing the ability of the worker and assigning tasks accordingly. This paper represents the results from a preliminary study to recognize the speech from human voice using mel-frequency cepstrum coefficients (MFCC) features. The 16 mel-scale warped cepstral coefficients were used independently for reorganization of speech from two Bangla commands of our native language. Cepstral coefficients for the utterance of `BATI JALAO' (i.e., TURN ON LIGHT) and `PAKHA BONDHO KORO' (i.e., TURN OFF FAN) from a particular speaker under preliminary investigation were used as features in a neural network. Network is trained using the MFCC features of two speakers in such a way that it can recognize only one particular person along with his command and terminate the program for other. Result of matching features in a neural network demonstrates that MFCC features work significantly to recognize speech.

A study on the carbon dioxide injection into coal seam aiming at enhancing coal bed methane (ECBM) recovery

Abstract: Coal seams, particularly deep unmineable coal reservoirs, are the most important geological desirable formations to store CO2 for mitigating the emissions of greenhouse gas. An advantage of this process is that a huge quantity of CO2 can be sequestrated and stored at relatively low pressure, which will reduce the amount of storage cost required for creating additional platform to store it. The study on CO2 storage in coal seam to enhance coal bed methane (ECBM) recovery has drawn a lot of attention for its worldwide suitability and acceptability and has been conducted since two decades in many coalmines. This article focuses on the coal seam properties related to CO2 adsorption/desorption, coal swelling/shrinkage, diffusion, porosity and permeability changes, thermodynamic/thermochemical process, flue gas injection, etc. Here, the performance analysis of both CO2 storage and ECBM recovery process in coal matrixes is investigated based on the numerical simulation. In this study, a one-dimensional mathematical model of defining mass balances is used to interpret the gas flow and the gas sorption and describe a geomechanical relationship for determining the porosity and the permeability alteration at the time of gas injection. Vital insights are inspected by considering the relevant gas flow dynamics during the displacement and the influences of coal swelling and shrinkage on the ECBM operation. In particular, pure CO2 causes more displacement that is more efficient in terms of total CH4 recovery, whereas the addition of N2 to the mixture assists to make quicker way of the initial methane recovery. However, this study will support future research aspirants working on the same topic by providing a clear conception and limitation about this study.