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21.
Prediction of total bed material load for rivers in Malaysia: A case study of Langat,Muda and Kurau Rivers 总被引:1,自引:0,他引:1
Aminuddin Ab. Ghani H. Md. Azamathulla Chun Kiat Chang Nor Azazi Zakaria Zorkeflee Abu Hasan 《Environmental Fluid Mechanics》2011,11(3):307-318
A soft computational technique is applied to predict sediment loads in three Malaysian rivers. The feed forward-back propagated
(schemes) artificial neural network (ANNs) architecture is employed without any restriction to an extensive database compiled
from measurements in Langat, Muda, Kurau different rivers. The ANN method demonstrated a superior performance compared to
other traditional sediment-load methods. The coefficient of determination, 0.958 and the mean square error 0.0698 of the ANN
method are higher than those of the traditional method. The performance of the ANN method demonstrates its predictive capability
and the possibility of generalization of the modeling to nonlinear problems for river engineering applications. 相似文献
22.
Latif MT Baharudin NH Velayutham P Awang N Hamdan H Mohamad R Mokhtar MB 《Environmental monitoring and assessment》2011,181(1-4):479-489
The renovation of a building will certainly affect the quality of air in the vicinity of where associated activities were undertaken, this includes the quality of air inside the building. Indoor air pollutants such as particulate matter, heavy metals, and fine fibers are likely to be emitted during renovation work. This study was conducted to determine the concentration of heavy metals, asbestos and suspended particulates in the Biology Building, at the Universiti Kebangsaan, Malaysia (UKM). Renovation activities were carried out widely in the laboratories which were located in this building. A low-volume sampler was used to collect suspended particulate matter of a diameter size less than 10 μm (PM??) and an air sampling pump, fitted with a cellulose ester membrane filter, were used for asbestos sampling. Dust was collected using a small brush and scope. The concentration of heavy metals was determined through the use of inductively coupled plasma-mass spectroscopy and the fibers were counted through a phase contrast microscope. The concentrations of PM?? recorded in the building during renovation action (ranging from 166 to 542 μg m?3) were higher than the value set by the Department of Safety and Health for respirable dust (150 μg m?3). Additionally, they were higher than the value of PM?? recorded in indoor environments from other studies. The composition of heavy metals in PM?? and indoor dust were found to be dominated by Zn and results also showed that the concentration of heavy metals in indoor dust and PM?? in this study was higher than levels recorded in other similar studies. The asbestos concentration was 0.0038 ± 0.0011 fibers/cc. This was lower than the value set by the Malaysian Department of Occupational, Safety and Health (DOSH) regulations of 0.1 fibers/cc, but higher than the background value usually recorded in indoor environments. This study strongly suggests that renovation issues need to be considered seriously by relevant stakeholders within the university in order to ensure that the associated risks toward humans and indoor environment are eliminated, or where this is not feasible, minimized as far as possible. 相似文献
23.
Sansuddin N Ramli NA Yahaya AS Yusof NF Ghazali NA Madhoun WA 《Environmental monitoring and assessment》2011,180(1-4):573-588
Malaysia has experienced several haze events since the 1980s as a consequence of the transboundary movement of air pollutants emitted from forest fires and open burning activities. Hazy episodes can result from local activities and be categorized as "localized haze". General probability distributions (i.e., gamma and log-normal) were chosen to analyze the PM(10) concentrations data at two different types of locations in Malaysia: industrial (Johor Bahru and Nilai) and residential (Kota Kinabalu and Kuantan). These areas were chosen based on their frequently high PM(10) concentration readings. The best models representing the areas were chosen based on their performance indicator values. The best distributions provided the probability of exceedances and the return period between the actual and predicted concentrations based on the threshold limit given by the Malaysian Ambient Air Quality Guidelines (24-h average of 150 μg/m(3)) for PM(10) concentrations. The short-term prediction for PM(10) exceedances in 14 days was obtained using the autoregressive model. 相似文献
24.
Abu Hassan Norhasmillah Chiew Wei Puah Nor Azowa Ibrahim Azhari Samsu Baharuddin Yuen May Choo 《Environment, Development and Sustainability》2013,15(6):1663-1670
This paper compared the life cycle inventory (LCI) obtained from three commercial oil palm biomass composting projects in Malaysia which use the open windrow composting system. The LCI was obtained and calculated based on the functional unit of 1 t of compost produced. The input of the inventory are the feed materials such as empty fruit bunches (EFB) and palm oil mill effluent (POME); and utilities which include electricity generated at palm oil mill and diesel used. Composting 2.0–2.5 t of EFB and 5.0–7.5 t of POME required diesel from 218.7 to 270.2 MJ and electricity from 0 to 6.8 MJ. It is estimated that the composting emitted from 0.01 to 0.02 t CO2eq/tcompost mainly from diesel used to operate machineries. Composting saved 65 % of time required for a complete degradation of POME when compared to ponding system, and 89 % of time required for a complete degradation of EFB compared to mulching. In terms of land required, it required 36 % less land as compared to ponding for POME and 99 % less land as compared to mulching for EFB. Based on the case study, diesel was found to be the main contributor to the environmental impact. There is a potential of upgrading the process to be more economical and environmental friendly. Using electricity as the source of energy has a lower footprint for the composting process. Instead of using raw POME, studies had reported that using treated POME either from anaerobic ponding or digested tank can accelerate the composting process. 相似文献
25.
Babalghaith Ali Mohammed Koting Suhana Sulong Nor Hafizah Ramli Khan Md Zahid Hossain Milad Abdalrhman Yusoff Nur Izzi Md. Ibrahim Mohd Rasdan Mohamed Abdul Halim bin Nagor 《Environmental science and pollution research international》2022,29(24):35557-35582
Environmental Science and Pollution Research - The daily utilization of a large amount of raw materials is causing a rapid depletion of natural resources. The growth of the human population is... 相似文献
26.
Malik Nur Khaliesah Abdul Manaf Latifah Abd Jamil Nor Rohaizah Rosli Mohd Hafiz Ash’aari Zulfa Hanan Othman Mohamad Al-Ekhwan 《Journal of Material Cycles and Waste Management》2021,23(4):1289-1302
Journal of Material Cycles and Waste Management - The accumulation of floatable litter load captured in gross pollutant trap (GPT) due to the hydrological runoff has become challenging due to rapid... 相似文献
27.
Yoon Yee Then Nor Azowa Ibrahim Wan Md Zin Wan Yunus 《Journal of Polymers and the Environment》2011,19(2):535-539
Polycaprolactone/tapioca starch/octadecylamine modified clay (OMMT) nanocomposites were successfully prepared by melt blending.
X-ray diffraction and transmission electron microscopy (TEM) of the products showed that they are nanocomposites of a mixture
intercalated and exfoliated types. In addition, the TEM also revealed that the OMMT layers are homogeneously distributed in
the polymer matrix. The presence of 1 php of OMMT improved the compatibility of the polymers in the blends which consequently
increased the tensile strength of the blend of more than 60% and elongation at break of more than 1,000%. 相似文献
28.
Jeremy?Andy?DominicEmail author Ahmad?Zaharin?ArisEmail author Wan?Nor?Azmin?Sulaiman Wan?Zakaria?Wan?Md?Tahir 《Environmental monitoring and assessment》2016,188(3):191
The approach of this paper is to predict the sand mass distribution in an urban stormwater holding pond at the Stormwater Management And Road Tunnel (SMART) Control Centre, Malaysia, using simulated depth average floodwater velocity diverted into the holding during storm events. Discriminant analysis (DA) was applied to derive the classification function to spatially distinguish areas of relatively high and low sand mass compositions based on the simulated water velocity variations at corresponding locations of gravimetrically measured sand mass composition of surface sediment samples. Three inflow parameter values, 16, 40 and 80 m3 s?1, representing diverted floodwater discharge for three storm event conditions were fixed as input parameters of the hydrodynamic model. The sand (grain size?>?0.063 mm) mass composition of the surface sediment measured at 29 sampling locations ranges from 3.7 to 45.5 %. The sampling locations of the surface sediment were spatially clustered into two groups based on the sand mass composition. The sand mass composition of group 1 is relatively lower (3.69 to 12.20 %) compared to group 2 (16.90 to 45.55 %). Two Fisher’s linear discriminant functions, F 1 and F 2, were generated to predict areas; both consist of relatively higher and lower sand mass compositions based on the relationship between the simulated flow velocity and the measured surface sand composition at corresponding sampling locations. F 1?=??9.405?+?4232.119?×?A???1795.805?×?B?+?281.224?×?C, and F 2?=??2.842?+?2725.137?×?A???1307.688?×?B?+?231.353?×?C. A, B and C represent the simulated flow velocity generated by inflow parameter values of 16, 40 and 80 m3 s?1, respectively. The model correctly predicts 88.9 and 100.0 % of sampling locations consisting of relatively high and low sand mass percentages, respectively, with the cross-validated classification showing that, overall, 82.8 % are correctly classified. The model predicts that 31.4 % of the model domain areas consist of high-sand mass composition areas and the remaining 68.6 % comprise low-sand mass composition areas. 相似文献
29.
Salman Abdo Al-Shami Mad Rawi Che Salmah Ahmad Abu Hassan Mohd Nor Siti Azizah 《Environmental monitoring and assessment》2011,177(1-4):233-244
Morphological mentum deformities which represent sublethal effect of exposure to different types of pollutants were evaluated in Chironomus spp. larvae inhabiting three polluted rivers of Juru River Basin in northwestern peninsular Malaysia. Using mentum deformity incidences, the modified toxic score index (MTSI) was developed based on Lenat??s toxic score index (TSI). The suggested MTSI was compared with TSI in terms of its effectiveness to identify different pollutants including heavy metals. The MTSI showed stronger relationship to total deformity incidence expressed as percentage. Additionally, the multivariate RDA model showed higher capability of MTSI to explain the variations in heavy metal contents of the river sediments. The MTSI was recommended in bioassessment of water and sediment quality using the mentum deformities of Chironomus spp. larvae from aquatic ecosystems receiving anthropogenic, agricultural, or industrial discharges. 相似文献
30.
Khairudin Nor Fazila Mohammadi Maedeh Mohamed Abdul Rahman 《Environmental science and pollution research international》2021,28(23):29157-29176
Environmental Science and Pollution Research - This study deals with the development of alumina-supported cobalt (Co/Al2O3) catalysts with remarkable performance in dry reforming of methane (DRM)... 相似文献