Universiti Teknologi Malaysia

About: Universiti Teknologi Malaysia is a education organization based out in Johor Bahru, Malaysia. It is known for research contribution in the topics: Membrane & Control theory. The organization has 21644 authors who have published 39500 publications receiving 520635 citations.

Bioaccumulation and potential sources of heavy metal contamination in fish species in River Ganga basin: Possible human health risks evaluation.

Abstract: This paper assesses the potential human health risks posed by five heavy metals (Zn, Pb, Cu, Cd, and Cr) found in seven most consumable fish species (Cirrhinus mrigala, Cirrhinus reba, Catla catla, Lebio rohita, Crossocheilus latius, Clupisoma garua, and Mystus tengara) collected from local markets of Varanasi, Allahabad, Mirzapur, and Kanpur of Uttar Pradesh, India. The Cu concentration was found at Varanasi (4.58 mg/l), Allahabad (2.54 mg/l), and Mirzapur (2.54 mg/l). Pb was recorded 0.54, 0.62, 0.85, and 0.24 mg/l at Kanpur, Allahabad, Mirzapur, and Varanasi, respectively. The Cd concentration was recorded 0.54, 0.68, 0.78, and 0.85 mg/l at Kanpur, Allahabad, Mirzapur, and Varanasi, respectively. The Cr, Cd, and Pb concentrations in the river water were observed over the prescribed safe limits at all sampling sites, while Cu concentration was higher than the standards at all sites except Kanpur. However, Zn was observed under the permissible limits (15 mg/l) at all sampling sites. In case of fish tissues, WHO reported the concentration of Pb, Cd, and Cr higher than the prescribed safe limits. The results determined that the highest heavy metals accumulation was found settled in the liver of all selected fish species. Zn ranked the highest quantity, which was found in fish tissues with the concentration of 32.41 ± 2.55 μg/g in the gill of C. catla and 4.77 ± 0.34 μg/g in the gill C. Reba. The metals followed the magnitude order of Zn > Pb > Cu > Cd > Cr in selected fish tissues.

Well-designed ZnV2O6/g-C3N4 2D/2D nanosheets heterojunction with faster charges separation via pCN as mediator towards enhanced photocatalytic reduction of CO2 to fuels

Abstract: Fabrication of well-designed 2D/2D heterojunction composite with effective interfacial contact by incorporating zinc vanadium oxide (ZnV2O6) and protonated g-C3N4 (pCN) for enhanced photocatalytic CO2 reduction has been investigated. The 2D/2D ZnV2O6/pCN samples, synthesized by a one-pot solvothermal method, were analysed using XRD, SEM, EDX-mapping, TEM, N2 sorption, XPS, UV–vis, RAMAN and PL characterization techniques. It was observed that surface charge modification through protonation of graphitic carbon nitride serves as a mediator and trapped photo-excited electrons. The performance of composite catalysts was investigated in a liquid and gas phase photocatalytic systems under UV and visible light irradiations. Using slurry system, CH3OH production rate enhanced up to 3742 μmol g-cat−1 over ZnV2O6/pCN, 1.15 and 5 times higher than the pure ZnV2O6 (3254 μmol g-cat−1) and pCN (753 μmol g-cat−1) samples, respectively. Instead, the CO evolution rate as a main product over ZnV2O6/pCN nanosheets of 3237 μmol g-cat−1 was obtained using gas phase system. This enhanced activity can be mainly ascribed to the addition of pCN with ZnV2O6 in a controlled ratio as well as synergistic effect of ZnV2O6/pCN nanosheet heterojunctions. Besides, hierarchical structure, higher interfacial interaction, abundant 2D coupling interfaces and efficient separation of charges could efficiently promote both the photo-activity and products selectivity. The obtained ZnV2O6/pCN 2D/2D nanosheets heterojunction with a mediator exhibited excellent photocatalytic stability, which prevailed even after 32 h of operation time for continuous CH3OH production. The possible reaction mechanism anticipated to understand the movement of electrons and holes for CO2 reduction over the ZnV2O6/pCN photocatalyst.

Development of an adaptive thermal comfort equation for naturally ventilated buildings in hot-humid climates using ASHRAE RP-884 database

Abstract: The objective of this study was to develop an adaptive thermal comfort equation for naturally ventilated buildings in hot–humid climates. The study employed statistical meta-analysis of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) RP-884 database, which covered several climatic zones. The data were carefully sorted into three climate groups including hot–humid, hot–dry, and moderate and were analyzed separately. The results revealed that the adaptive equations for hot-humid and hot-dry climates were analogous with approximate regression coefficients of 0.6, which were nearly twice those of ASHRAE and European standards 55 and EN15251, respectively. The equation using the daily mean outdoor air temperature had the highest coefficient of determination for hot–humid climate, compared with other mean temperatures that considered acclimatization of previous days. Acceptable comfort ranges showed asymmetry and leaned toward operative temperatures below thermal neutrality for all climates. In the hot–humid climate, a lower comfort limit was not observed for naturally ventilated buildings, and the adaptive equation was influenced by indoor air speed rather than indoor relative humidity. The new equation developed in this study can be applied to tropical climates and hot–humid summer seasons of temperate climates.

Characteristics of heat transfer and fluid flow in microtube and microchannel using conventional fluids and nanofluids: A review

Abstract: Research on convective heat transfer on internal microtube and microchannel has been extensively conducted in the past decade. This review summarizes numerous researches on two topics; the first section focuses on studying the fluid flow and heat transfer behavior of different types of microtubes (MT) and microchannel (MC) at different orientations. The second section concentrates on nanofluids; its preparation, properties, behavior, and many others. The purpose of this article is to get a clear view and detailed summary of the influence of several parameters such as the geometrical specifications, boundary conditions, and type of fluids. The maximum Nusselt number is the main target of such research where correlation equations were developed in experimental and numerical studies are reported. The heat transfer enhancement of nanofluids along with the nanofluids preparation technique, types and shapes of nanoparticles, base fluids and additives, transport mechanisms, and stability of the suspension are also discussed.