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.

Origin of high hardness and optoelectronic and thermo-physical properties of boron-rich compounds B6X (X = S, Se): a comprehensive study via DFT approach

Abstract: In the present study, the structural and hitherto uninvestigated mechanical (elastic stiffness constants, machinability index, Cauchy pressure, anisotropy indices, brittleness/ductility, Poissons ratio), electronic, optical, and thermodynamic properties of novel boron-rich compounds B6X (X = S, Se) have been explored using density functional theory The estimated structural lattice parameters were consistent with the prior report The mechanical and dynamical stability of these compounds have been established theoretically The materials are brittle in nature and elastically anisotropic The value of fracture toughness, KIC for the B6S and B6Se are ~ 207 MPam05, evaluating the resistance to limit the crack propagation inside the materials Both B6S and B6Se compounds possess high hardness values in the range 31-35 GPa, and have the potential to be prominent members of the class of hard compounds Strong covalent bonding and sharp peak at low energy below the Fermi level confirmed by partial density of states (PDOS) resulted in the high hardness The profile of band structure, as well as DOS, assesses the indirect semiconducting nature of the titled compounds The comparatively high value of Debye temperature ({\Theta}D), minimum thermal conductivity (Kmin), lattice thermal conductivity (kph), low thermal expansion coefficient, and low density suggest that both boron-rich chalcogenides might be used as thermal management materials Large absorption capacities in the mid ultraviolet region (32-15 eV) of the studied materials and low reflectivity (~16 %) are significantly noted Such favorable features give promise to the compounds under investigation to be used in UV surface-disinfection devices as well as medical sterilizer equipment applications Excellent correlations are found among all the studied physical properties of these compounds

Response of Eucalyptus camaldulensis and Acacia mangium kraft pulp in different ECF bleaching options

Abstract: In this study, the response of Eucalyptus camaldulensis and Acacia mangium kraft pulp to different options of ECF bleaching was investigated. Oxygen-delignified pulps of both species having similar kappa number (c.a. 12) were used. Both the pulps were prebleached using conventional ClO2 stage (D0), combined use of ClO2 and O3 (DZ), hot acid treatment before D0 (AhotD0) and hot acid treatment before (DZ) i.e., Ahot(DZ), hot ClO2 treatment (DHT) and Ahot followed by DHT (AhotDHT). All prebleached pulps were finally bleached to 90%+ ISO brightness using D1 option. The overall benefits of other options were not considerable compared to D0 and (DZ). From the ClO2 consumption point of view, for a certain species, the option Ahot(DZ) was the best. Instead of D1 in final bleaching, pressurized hydrogen peroxide (PO) was also investigated in the case of D0 and (DZ) prebleached pulps. (PO)-bleached pulp produced higher brightness stability but lower viscosity compared to D1.

Effect of Cu substitution on structural and electric transport properties of Ni-Cd nanoferrites

Abstract: Nanocrystalline samples of Ni0.7−xCuxCd0.3Fe2O4 (x = 0.0–0.5, with step of 0.1) have been synthesized via auto-combusted sol-gel method. In this study, we present the structural and electric properties of Cu substituted Ni-Cd ferrite nanoparticles at room temperature with varying frequencies from 20 Hz to 15 MHz. X-ray diffraction (XRD) patterns of samples confirm the single-phase cubic spinel structure without impurity. The crystallite size of samples is found in the nano-scale range (17–27 nm) and the lattice parameter is found to increase linearly with Cu content. The surface morphology of samples is studied through a Field Emission Scanning Electron Microscopy (FESEM) and the presence of elements in the samples are confirmed by Energy Dispersive X-ray (EDX) techniques. The materials show dielectric dispersion up to 10 kHz frequencies and their loss tangent values remain very low at MHz frequencies. The impedance and modulus spectroscopy confirm the existence of non-Debye relaxation phenomena of the materials and resolve the contribution of grain and grain boundary. The ac conductivity shows normal behavior with frequency, which is explained on the basis of hopping mechanism.

An Outlook over Electrical Energy Generation and Mixing Policies of Bangladesh to Achieve Sustainable Energy Targets -Vision 2041

Abstract: This paper presents an outlook on the power generation and mixing policies taken by the Government of Bangladesh (GOB) to remove energy crisis and ensure energy access. Electricity generation and fulfilling people's demand with limited energy resources is very challenging for a developing country like Bangladesh. Over the last two decades, energy consumption in Bangladesh has been rising rapidly for the acceleration of economic growth and sustainable development. Conventional energy sources like natural gas, oil, coal, and some non-conventional energy sources are trying to fulfil the present energy demand. As development of the economy directly depends on the energy, a commitment of the current government to ensure the affordability of electricity for all citizens by 2041. The goal of this study is to analyze and compare the present and past energy consumption and reserve energy resources of Bangladesh, problems, and policies to meet present demand as well as future power demands.