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: Renewable energy & Dielectric. 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.

The design of expressive intelligent agent for human-computer interaction

Abstract: Now a day, people are getting intensely attached to communicate with others in virtual environments using various virtual agents due to their popularity. Most of these environments used emoticon for displaying emotion of interacting partners to each other. However, emoticon based systems often makes the interaction lifeless and monotonous. This paper focus on developing a human-like virtual agent that produces facial expressions with motions (such as head movement and eye blinks) during human-computer interaction scenarios through analyzing the input text messages of users. This agent is capable to display six facial expressions namely, happy, sad, angry, disgust, fear, and surprise based on the chatting partner's input text that makes the interaction enjoyable. Experimental evaluation reveals that the proposed agent can display emotive expressions correctly 92% of the times from the users' text input and it creates a better feeling of making interaction to the partners than the emoticon bases systems.

Performance Enhancement of Induced Draft Counter Flow Wet Cooling Tower with Different Types of Modified Shaped Fill Assembly

Abstract: This paper presents an experimental analysis of heat transfer using different shaped fills in a counter flow induced draft cooling tower. The main objective is to determine and compare the characteristics of the cooling tower using newly shaped (splash and film) fills and the regular used fills. The newly shaped fills are inverted U-shape cross-sectional splash fill and film fill with ripple plates. The obtained results show that the performance is affected by the type and arrangement of the fills. The modified splash fill has increased the wetted surface area of fill within the same volume compared to regular fills. The film fill with ripple plates has been used such that water from the distribution device ran down on both surfaces of each ripple plate. By the arrangement of ripple plates, cooling loss by premature dropping off of water has been avoided. Performance factors like range, approach, effectiveness, cooling capacity, evaporation loss, percent loss are calculated from collected data for newly shaped fills, and regular shaped fills. It is observed that range, effectiveness, and cooling capacity increases with both newly shaped fills. When ripple plated film fill is used; range, effectiveness, and cooling capacity is found highest among the different shape of fills used in this study. At the same time evaporation loss and percent loss are found lowest for inverted-U shaped splash fill. Original Research Article Dewanjee et al.; JERR, 16(2): 41-53, 2020; Article no.JERR.59651 42

Edible bio-oil production from microalgae and application of nano-technology

Abstract: Microalgae have been preferred as an excellent candidate for edible bio-oil production in recent decades due to the abundant cellular polyunsaturated fatty acid, high photosynthetic rate, and biomass productivity and significant amount of oil extraction superior to terrestrial oleaginous crops. This chapter discusses suitable microalgae candidates for edible bio-oil production, as well as the implementation of nanotechnology to improve the growth of different microalgae species. In addition, it provides a comprehensive analysis of the numerous technologies for microalgae pretreatment processes prior to bio-oil extraction, recovery, and purification. Finally, it discusses the socioeconomic and environmental impacts of bio-oil production from microalgae as well as other high-value products through an integrated approach. This approach can play a positive role in the near future to mitigate the high demand for edible oil consumption as well as other value-added products can be applied significantly in cosmetic, pharmaceutical, and food industries.

Tuning of Optical Band Gap: Genesis of Thickness Regulated Al Doped ZnO Nano-Crystalline Thin Films Formulated by Sol–Gel Spin Coating Approach

Abstract: Intrinsic zinc oxide thin films have deficiencies in terms of structural, optical and electronic characteristics, which has given rise to researches on metal doped zinc oxide films in the interest of enhancing its characteristics. Indium tin oxide, Au, Ag, Pt and Ti; which are extensively used in industrial level thin film applications but aluminum has low cost than those metals, so by doping with this on ZnO thin films, its performance and quality on the morphological, elemental, structural, optical and electrical attributes were analyzed in this research. Tuning of ZnO nanocrystalline thin films’ optical band gap, doped by different materials simplifies possible elements for photonic applications. Sol–gel spin coating method has been used for these analyses which was accustomed to gain the Al doped ZnO (AZO) parent compounds on silicon-glass substrates. Ultra violet visible spectrophotometer was used to determine band gap tuning characteristics, urbach energy, transmittance and absorption properties. The Moss-Burstein outcome imprints the blue shift with thickness increment of the absorption end and there is a clear relationship between band gap and urbach energy. Tuning of band gap value varies from 3.22 eV to 3.26 eV by varying the film thickness from 100 to 300 nm. A non-linear, non-monotonic relation has been seen for the change of optical and structural parameters of AZO thin films. Deep research of structural and optical properties represents important information to get a better perspective of band gap dependence on structural properties.