Measurement of indoor air quality parameters in daycare centres in Kuala Lumpur Malaysia

This paper focuses on the monitoring of indoor air quality parameters, namely: indoor temperature, humidity, velocity, particulate matter, carbon monoxide and carbon dioxide in day care centres. This study selected 15 day care centres located in Kuala Lumpur, Malaysia. These day care centres were categorized as follows: (1) day care centers near an industrial area, (2) day care centers near a main road, and (3) day care centers in a residential area. The obtained data showed that the values for the indoor air quality parameters in all day care centres were still well below the recommended value according to the Department of Safety and Health, Malaysia. The day care centers near an industrial area had the highest value of carbon monoxide, and carbon dioxide as compared to the day care centers near a main road and the day care centers in a residential area. The average concentrations of carbon monoxide, and carbon dioxide in the day care centers near an industrial area were 3.67 ppm and 801.56 ppm respectively. Meanwhile, the carbon monoxide, and carbon dioxide in the day care centers near a main road area and the day care centers in a residential area were 3.13 ppm, 768.22 ppm, 2.92 ppm and 733.70 ppm, respectively

Assessment of children's health and indoor air contaminants of day care centre in industrial area

Background: Carbon dioxide (CO2) is one of the most commonly used indicators of indoor air quality (IAQ) in industrial area. The higher concentration level of CO2 and particulate matter (PM10) in day care centre could affect children’s health. The objective of this study was to assess children’s health symptom, and measure the CO2 and PM10 concentration level as IAQ parameters in different locations of day care centres near the industrial area at Kuala Lumpur, Selangor and Hulu Langat as urban, suburban and rural areas respectively. Methods: The data of children’s health symptom were collected from the distributed questionnaire. Results: The day care centres (DCC) in Kuala Lumpur has the highest number of children’s illness frequency of more than four times annually (11%), followed by the highest number of children who experienced asthma (5.3%), wheezing (3.3%) and coughing (10%). The results of data collection of day care centres in Kuala Lumpur, Selangor and Hulu Langat ranged between 629-830 ppm, 587-823 ppm and 600-830 ppm for CO2 level, and 60.80-78.60 mg/m3, 56.90-80.50 mg/m3 and 59.90-79.10 mg/m3 for PM10 level. The statistical analysis for CO2 level between areas was significantly different (P<0.05). Conclusion: Day care centers in Kuala Lumpur have the highest mean rate of CO2 and PM10 as well as frequency of children’ illness which could identify traffic congestion and less greenery of a densely populated city

Monitoring of indoor air quality parameters in the day-care centres in tropical country

Indoor air quality monitoring in various public premises such as school, day-care centre, office and industrial factory buildings has attracting many scientist, researchers as well as academicians. Since most people spends their daily activity outside their house, poor indoor air quality in all sort of location of public places can be related with their health and life comfort as human beings. This paper involved in monitoring the indoor air quality in two location of day-care centre. First location is Federal Territory of Kuala Lumpur, being the capital city of Malaysia. Second location is Selangor, which could be categories as suburban area. Temperature, humidity, air velocity, particulate matter (PM10), carbon monoxide (CO) and carbon dioxide (CO2) were measured as the parameters of indoor air quality in this study. Total 30 day-care centres in Kuala Lumpur and Selangor were selected for this study. The monitoring was conducted during the day-care centre operating hours from 9am to 5pm (8hours) using IAQ meter TSI 8762 for measurement of temperature, humidity, CO and CO2, Dust Trak TSI 8520 for the measurement of PM10 and VeloCalc TSI 9555 for the measurement of air velocity. The CO, CO2and PM10 levels indicated that the city of Kuala Lumpur has higher pollutant levels than suburban area or Selangor

Numerical Analysis of Battery Thermal Management System of Electric Vehicle

This study is modelling the direct liquid cooling system of battery used in Electric Vehicle. The purpose of the study is to investigate the performance of the Li-ion battery model under different input of parameters and to evaluate the optimum parameters for the battery thermal management system model to maintain at its peak performance. SolidWorks and ANSYS are used to model and simulate the battery whereas MINITAB software is selected for conducting the statistical analysis. Heat flux, mass flow rate at the inlet and the thickness of the battery model has been selected as input of the simulation. The obtained results show that the heat transfer coefficient is increasing with the higher heat flux and mass flowrate but decreasing with the thickness of the battery model. Pressure drop remains constant when heat flux varies but increasing with mass flow rate and inversely proportional with the thickness of battery. For statistical analysis, an optimum value for the parameters is proposed to maintain the battery to operate with a highest heat transfer coefficient but lowest in pressure difference. Overall, the study has been conducted successfully and fulfilled the objectives stated

Heavy metal recovery from electric arc furnace steel slag by using hydrochloric acid leaching

Electric Arc Furnace steel slag (EAFS) is the waste produced in steelmaking industry. Environmental problem such as pollution will occur when dumping the steel slag waste into the landfill. These steel slags have properties that are suitable for various applications such as water treatment and wastewater. The objective of this study is to develop efficient and economical chlorination route for EAFS extraction by using leaching process. Various parameters such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature are investigated to determine the optimum conditions. As a result, the dissolution rate can be determined by changing the parameters, such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature. The optimum conditions for dissolution rates for the leaching process is at 3.0 M hydrochloric acid, particle size of 1.18 mm, reaction time of 2.5 hour and the temperature of 90˚C

Bio-Nanocomposite Polyurethane / Clay / Chitosan Paints that have thermal resistance and antibacterial properties for biomedical applications

The coating material used for the manufacture of polyurethane paints is a coating of hybrid organic-inorganic materials based on palm oil (oleic acid). Polyols are produced from the synthesis of oleic acid by adding organic and inorganic ingredients. Chitosan and bentonite are organic and inorganic elements, which are used to improve thermal capability and antibacterial properties of polyurethane paint produced. Hybrid bentonite-chitosan is then synthesized with polyols and isocyanate is added, namely TDI (Toluene Diisocyanate) to form polyurethane. In the FTIR spectrum of the polyol on O-H bond at Wavelength 3210.25 cm-1, C-H bond at Wavelength 2856.87 cm-1 and C = O bond at Wavelength 1610.86 cm-1, and hybrid bentonitechitosan of FTIR Analysis Chitosan: -OH group at Wavelength 3250 cm-1, N-H at 3545 cm-1, C = O at wavelength 1681 cm-1, C-H group at Wavelength 2810 cm-1. Bentonite: -OH group at Wavelength 3435 cm-1, Si-O group at Wavelength of 1161 cm-1 and Al-O and Si-O groups at Wavelength 820 cm-1. Aliphatic C-H Cluster at 2815 cm-1 Wavelength and 1125 cm-1 Wavelength indicates the presence of a C-O group. While the results of SEM (Scanning Electron Microscope) from polyurethane products and with the addition of hybrid bentonite-chitosan namely polyurethane paints produced mixed with chemicals and the main ingredients are polyols from palm oil (oleic acid) while small white clumps greyish namely hybrid bentonite-chitosan which has been mixed into polyurethane paint. This study produced a hybrid material of benthicchitosan as a filler in the manufacture of polyurethane paint

Characterization of PLA/PCL/Nano-Hydroxyapatite (nHA) biocomposites prepared via cold isostatic pressing

Hydroxyapatite has the closest chemical composition to human bone. Despite this, the use of nano-hydroxyapatite (nHA) to produce biocomposite scaffolds from a mixture of polylactic acid (PLA) and polycaprolactone (PCL) using cold isostatic pressing has not been studied intensively. In this study, biocomposites were created employing nHA as an osteoconductive filler and a polymeric blend of PLA and PCL as a polymer matrix for prospective usage in the medical field. Cold isostatic pressing and subsequent sintering were used to create composites with different nHA concentrations that ranged from 0 to 30 weight percent. Using physical and mechanical characterization techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and density, porosity, tensile, and flexural standard tests, it was determined how the nHA concentrations affected the biocomposite’s general properties. In this study, the presence of PLA, PCL, and nHA was well identified using FTIR, XRD, and SEM methods. The biocomposites with high nHA content showed intense bands for symmetric stretching and the asymmetric bending vibration of PO43−. The incorporation of nHA into the polymeric blend matrix resulted in a rather irregular structure and the crystallization became more difficult. The addition of nHA improved the density and tensile and flexural strength of the PLA/PCL matrix (0% nHA). However, with increasing nHA content, the PLA/PCL/nHA biocomposites became more porous. In addition, the density, flexural strength, and tensile strength of the PLA/PCL/nHA biocomposites decreased with increasing nHA concentration. The PLA/PCL/nHA biocomposites with 10% nHA had the highest mechanical properties with a density of 1.39 g/cm3, a porosity of 1.93%, a flexural strength of 55.35 MPa, and a tensile strength of 30.68 MPa

Experimental investigation on performance of short pineapple leaf fiber reinforced tapioca biopolymer composites

The performance of short pineapple leaf fiber (PALF) reinforced tapioca biopolymer (TBP) composites were investigated, specifically the effect of fiber length and fiber composition on mechanical properties (tensile properties, flexural strength, and impact strength). Composite samples with different fiber lengths (< 0.50 mm, 0.51 mm to 1.00 mm, and 1.01 mm to 2.00 mm) and different fiber compositions (10%, 20%, 30%, and 40%) were prepared through crushing, sieving, internal mixing, compression molding, and machining processes. The combination of PALF and TBP enhanced the mechanical properties of composites with 30% as the optimum fiber content. However, the influence of different fiber lengths up to 2.00 mm provided no significant effect on producing maximum tensile properties. Good interfacial adhesion between PALF and TBP was evident from scanning electron microscopy analysis. Therefore, the combination of PALF and TBP has great potential as a renewable and biodegradable polymer. Moreover, PALF-TBP composites are expected to become alternatives to petroleum-based polymers

Influence of layering sequences on tensile properties of hybrid woven Jute/Ramie fibre reinforced polyester composites

Many researchers around the globe have shifted their focus onto the renewable resources lately. This trend is due to the number of resources that are almost reaching its critical stage hence the exploration of natural fibre composites has also caught the world's attention. In this research the effect of the number of layers, stacking sequences, and orientation of plain weave jute and ramie fibre single/hybrid composites on tensile properties were investigated. The stacking sequences consisted of two and three layered of laminated composite of pure jute (JJ, JJJ), pure ramie (RR, RRR) and ramie/ramie/ramie (RRR), whereas jute/ramie (JR), jute/jute/ramie (JJR), jute/ramie/jute (JRJ), ramie/jute/ramie (RJR), jute/ramie/ramie (JRR) were included under the hybrid composites category. The comparisons of tensile properties for each of the pure polyester, single, and hybrid composites were evaluated afterwards. The tensile strength and tensile modulus of the composites that was constructed with different fibre direction of warp and weft for each layer were also analyzed. The hand lay-up method was employed for all the fabrication of the composite specimens. From the results, it was observed that the tensile properties of the skin-core type composites (RJR, JRJ) have showed a better performance compared to the skin-eccentric types (RRJ, JJR) with similar ramie content. Attributed to a good fibre rigidity of Ramie fibre, the tensile strength and tensile modulus values could be enhanced with the addition of the ramie content in the composite mixture. The tensile properties were proven to also be improved with the increase number of woven layers in the composite. The Jute/ramie hybrid composite has exhibited very high potential in the future development of the automotive industry

Synthesis and characterization of PLA-Chitosan-ZnO composite for packaging biofilms

This research was conducted to improve the characteristics of PLA-Chitosan-ZnO composites. Composites are synthesized from the matrix of Poly lactic acid by modifying Chitosan and Zinc oxide (ZnO) fillers. The purpose of this study was to look at the mechanical, thermal and morphological characteristics seen from the composite. Basically, the bond between PLA and CS is very weak, so to increase the strength of the bond by entering ZnO; thus advancing overall quality (mechanical, thermal and water absorption) of composites (PLA / CS / ZnO). The mechanical properties of composites are enhanced by the addition of ZnO NP into the PLA / CS matrix. However, the tensile strength, modulus, and breakout extension increased to 2wt% of ZnO NP loading but decreased when ZnO NP content increased by 3wt%. This is consistent with the dispersion of homogeneous ZnO particles in the PLA matrix. Combining ZnO particles increases PLA thermal stability. Thus, ZnO has been shown to have potential as an amplifier in biocomposite synthesis with better integrity, although other approaches, such as the use of compatibilizers in ZnO surface modification, will be needed to improve PLA properties simultaneously. The results obtained in this work can be used on environmentally friendly films