THERMAL COMFORT IN TECHNICAL SCHOOL: PHYSICAL MEASUREMENT APPROACH

A field study on the relationship between thermal comfort and students’ performance was carried out in a technical school in Selangor. The buildings were mechanically ventilated by fans. The measured environmental parameters were air temperature (ºC), mean radiant temperature (ºC), relative humidity (%) and air velocity (m/s) of the surrounding classroom area. The environmental factors were measured using Thermal Comfort Equipment, which is capable to measure simultaneously all the environmental factors. All the windows were left open for natural ventilation. Subjective measurements were also conducted using survey questionnaire on the same days when the environmental factors were measured. The Predicted Mean Vote (PMV) was calculated using ASHRAE Thermal sensation scale which has been proposed earlier by Fanger (1970) for the measured data. Further Predicted Percentage Dissatisfied (PPD) was used to estimate the thermal comfort satisfaction of the occupant. The study revealed that 70% of the students’ population at the classroom is dissatisfied with the thermal comfort

Preparation, characterization and performances of photocatalytic TiO2-Ag2O/PESf membrane for methylene blue removal

This study proposed an effective method of methylene blue (MB) removal using a membrane with photocatalytic properties. The photocatalytic membrane, made of polyethersulfone (PESf) was incorporated with titanium dioxide (TiO2) and silver oxide (Ag2O) as the photocatalyst during the phase inversion process. TiO2 was synthesized using sol-gel method before being modified by Ag2O via wet pre-deposition method. The PESf/TiO2/Ag2O (PTA) membrane was characterized using scanning electron microscope coupled with elementary dispersion X-ray (SEM-EDX), X-ray diffraction analysis (XRD), attenuated Fourier transform infrared (ATR-FTIR), and ultraviolet visible near infrared (UV-vis NIR). The PTA membrane with 0.2 wt.% loading of TiO2/Ag2O shows uniform distribution of the photocatalyst materials and exhibits the highest degradation of MB at 85%. The TiO2/Ag2O presence was confirmed by the crystallinity analysis using XRD. UV-Vis NIR revealed that the band gap of TiO2 reduced from 3.2 to 2.1 eV when modified with Ag2O. This proved that membrane separation assisted with photocatalytic degradation is able to perform high degradation of MB dyes and has potential to be applied in industrial application

Selection of classification models from repository of model for water quality dataset

This paper proposes a new technique, Model Selection Technique (MST) for selection andranking of models from the repository of models by combining three performance measures(Acc, TPR and TNR). This technique provides weightage to each performance measure to findthe most suitable model from the repository of models. A number of classification modelshave been generated to classify water quality using the most significant features andclassifiers such as J48, JRip and BayesNet. To validate this technique proposed, the waterquality dataset of Kinta River was used in this research. The results demonstrate that theFunction classifier is the optimal model with the most outstanding accuracy of 97.02%, TPR =0.96 and TNR = 0.98. In conclusion, MST is able to find the most relevant model from therepository of models by using weights in classifying the water quality dataset.Keywords: selection of models; water quality; classification model; models repository

Fluvial processes in compound straight channels: a laboratory investigation

Floods are become frequent occurrence in every part of the world. The field of flood hydraulics has been keenly studied to enhance the understanding on its processes and impacts to the environment. The main impacts of frequent floods incidents are soil erosion phenomenon which leads to sedimentation problems in the drainage and river systems. It is extremely important to understand the sedimentation process and the flow behaviour patterns in the water course for post-flood events. Experimental investigations on the overbank flow in mobile bed straight channels have been undertaken. Significant changes on the bed morphology due to the changes in flow behaviour are studied. The findings on roughness coefficient, lateral distribution of stream-wise velocity, secondary currents, bed shear stress and bed formation are presented in this paper. Results show that the resistance coefficient increased with flow depth in the channel and the increments are about 32% and 42% for floodplain and main channel sections respectively

Decolourization and cod reduction of textile wastewater by ozonation in combination with biological treatment

ABSTRACT In this study, the characteristics of colour and chemical oxygen demand (COD) removal of azo dye by ozonation and biological treatment were evaluated for applying in industrial azo dye effluent treatment. Reactive Red 120 has been selected from among azo dyes due to its high solubility in an aquatic environment. The experimentation was arranged in two stages: during the first, only ozonation was performed, while, during the second stage, ozonation was integrated with biological treatment of completely mixed activated sludge (CMAS). COD removal was contributed simultaneously by the ozonation and biological treatment mechanism at lower ozone doses. However, it was significantly the result of direct oxidation at higher ozone doses. Ozonation of dyes usually leads to small organic molecular fragments that lead to a residual COD. The biological treatment is more efficient at mineralizing the by-products of the ozonation, but less efficient at colour reduction than the ozonation process itself. Thus, COD resulting from these small newly formed molecules can be further degraded by biological treatment. Therefore, ozonation should be applied at a medium ozone dose as a pre-treatment for a combined ozonationbiological treatment for azo dye removal

Preparation, characterization and performance evaluation of supported zeolite on porous glass hollow fiber for desalination application

A-type zeolite membranes were synthesized on porous glass hollow fibers that prepared using the in-situ hydrothermal process. The porous glass hollow fibers were prepared using the phase inversion and sintering technique with the addition of yttria stabilized zirconia (YSZ) to improve their porosity. The glass hollow fibers were characterized using the scanning electron microscope (SEM), Fourier transform infrared (FTIR), mechanical properties and water permeability. The porosities of pure glass hollow fiber were improved by the addition of YSZ particles, which lead to an increase in the pure water permeability. The water permeability shows that the glass hollow fiber prepared form spinning suspension E, which has 30 wt% zeolite particles and 20 wt% YSZ particles, has the highest permeability of 155.65 L m−2 hr−1 bar−1 compared to the previous work, which was only 4.0 L m−2 hr−1 bar−1. This glass hollow fiber was later used as the support for the incorporation of zeolite membrane for the desalination application. The performance of membranes is separating sodium chloride (NaCl) salt solution were tested using two different setups, namely pressure driven reverse osmosis (RO) and sweeping liquid assisted reverse osmosis (SLRO). The solute flux for 5,000 and 10,000 ppm NaCl salt solutions were 24.45 and 17.86 L m−2 hr−1, respectively. Both operations enabled the solute rejection up to 98%

Arthropods-mediated green synthesis of zinc oxide nanoparticles using cellar spider extract: a biocompatible remediation for environmental approach

This study presents an eco-friendly approach to synthesizing zinc oxide nanoparticles (ZnO NPs) using extracts from cellar spiders, addressing environmental and health concerns associated with conventional methods. The spider extract efficiently reduced zinc acetate dihydrate, and the synthesized ZnO NPs underwent comprehensive quantitative characterization, including size, shape, morphology, surface chemistry, thermal stability, and optical properties using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), zeta potential measurements, thermogravimetric analysis (TGA), and UV-vis spectroscopy. The nanoparticles exhibited intended characteristics, and their adsorption capability for methylene blue (MB) was quantitatively assessed using the Freundlich isotherm model and pseudo-second-order kinetic model, providing numerical insights into MB removal efficiency. The study demonstrates the potential of these green-synthesized ZnO NPs for applications in environmental remediation, wastewater treatment, and antibacterial therapies, contributing to both sustainable nanomaterial development and quantitative understanding of their functional properties

The Plasmodium falciparum STEVOR Multigene Family Mediates Antigenic Variation of the Infected Erythrocyte

Modifications of the Plasmodium falciparum–infected red blood cell (iRBC) surface have been linked to parasite-associated pathology. Such modifications enable the parasite to establish long-lasting chronic infection by evading antibody mediate immune recognition and splenic clearance. With the exception of the well-demonstrated roles of var-encoded PfEMP1 in virulence and immune evasion, the biological significance of other variant surface antigens (rif and stevor) is largely unknown. While PfEMP1 and RIFIN have been located on the iRBC surface, recent studies have located STEVOR at the iRBC membrane where it may be exposed on the erythrocyte surface. To investigate the role of STEVOR in more detail, we have developed antibodies against two putative STEVOR proteins and used a combination of indirect immunofluorescence assays (IFA), live IFA, flow cytometry, as well as agglutination assays, which enable us to demonstrate that STEVOR is clonally variant at the surface of schizont stage parasites. Crucially, expression of different STEVOR on the surface of the iRBC changes the antigenic property of the parasite. Taken together, our data for the first time demonstrate that STEVOR plays a role in creating antigenic diversity of schizont stage parasites, thereby adding additional complexity to the immunogenic properties of the iRBC. Furthermore, it clearly demonstrates that to obtain a complete understanding of how parasite-induced pathology is linked to variation on the surface of the iRBC, focusing the interactions of multiple multigene families needs to be considered