Displaying publications 1 - 20 of 119 in total

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  1. Zhao X, Lim SK, Tan CS, Li B, Ling TC, Huang R, et al.
    Materials (Basel), 2015 Jan 30;8(2):462-473.
    PMID: 28787950 DOI: 10.3390/ma8020462
    Foamed mortar with a density of 1300 kg/m³ was prepared. In the initial laboratory trials, water-to-cement (w/c) ratios ranging from 0.54 to 0.64 were tested to determine the optimal value for foamed mortar corresponding to the highest compressive strength without compromising its fresh state properties. With the obtained optimal w/c ratio of 0.56, two types of foamed mortar were prepared, namely cement-foamed mortar (CFM) and slag-foamed mortar (SFM, 50% cement was replaced by slag weight). Four different curing conditions were adopted for both types of foamed mortar to assess their compressive strength, ultrasonic pulse velocity (UPV) and thermal insulation performance. The test results indicated that utilizing 50% of slag as cement replacement in the production of foamed mortar improved the compressive strength, UPV and thermal insulation properties. Additionally, the initial water curing of seven days gained higher compressive strength and increased UPV values as compared to the air cured and natural weather curing samples. However, this positive effect was more pronounced in the case of compressive strength than in the UPV and thermal conductivity of foamed mortar.
    Matched MeSH terms: Weather
  2. Zhang X, Chan NW, Pan B, Ge X, Yang H
    Sci Total Environ, 2021 Nov 10;794:148388.
    PMID: 34217078 DOI: 10.1016/j.scitotenv.2021.148388
    The SAR has the ability of all-weather and all-time data acquisition, it can penetrate the cloud and is not affected by extreme weather conditions, and the acquired images have better contrast and rich texture information. This paper aims to investigate the use of an object-oriented classification approach for flood information monitoring in floodplains using backscattering coefficients and interferometric coherence of Sentinel-1 data under time series. Firstly, the backscattering characteristics and interference coherence variation characteristics of SAR time series are used to analyze whether the flood disaster information can be accurately reflected and provide the basis for selecting input classification characteristics of subsequent SAR images. Subsequently, the contribution rate index of the RF model is used to calculate the importance of each index in time series to convert the selected large number of classification features into low dimensional feature space to improve the classification accuracy and reduce the data redundancy. Finally, the SAR image features in each period after multi-scale segmentation and feature selection are jointly used as the input features of RF classification to extract and segment the water in the study area to monitor floods' spatial distribution and dynamic characteristics. The results showed that the various attributes of backscatter coefficients and interferometric coherence under time series could accurately correspond with the actual flood risk, and the combined use of backscattering coefficient and interferometric coherence for flood extraction can significantly improve the accuracy of flood information extraction. Overall, the object-based random forest method using the backscattering coefficient and interference coherence of Sentinel-1 time series for flood extraction advances our understanding of flooding's temporal and spatial dynamics, essential for the timely adoption of adaptation and mitigation strategies for loss reduction.
    Matched MeSH terms: Weather
  3. Wong JKH, Lee KK, Tang KHD, Yap PS
    Sci Total Environ, 2020 Jun 01;719:137512.
    PMID: 32229011 DOI: 10.1016/j.scitotenv.2020.137512
    The ubiquitous occurrences of microplastics in the environment have raised much concern and resulted in voluminous studies related to microplastics. Studies on microplastics pollution of the marine environment have received significantly higher attention compared to those of the freshwater and terrestrial environments. With the impetus to better understand microplastics in the freshwater and terrestrial environments, this review elucidates the findings of >100 articles related to the prevalence, fates and impacts of microplastics therein and the sustainable solutions, mostly in the past 10 years. This review shows the interconnection between terrestrial and freshwater microplastics with wastewater and sewage treatment plants as the most significant contributors of environmental microplastics via sludge and effluent discharges. Microplastics in both ecosystems comprise the primary and secondary forms with the latter resulted from weathering of the former. Besides retaining in soil and infiltrating with rainwater underground, terrestrial microplastics also enter the freshwater environment. The environmental microplastics interact with the biotic and abiotic components resulting in entrainment, settlement, biofouling, degradation, fragmentation and entry into the food chain, with subsequent transfer across the food chain. The abundance of environmental microplastics is attributed to population density and urbanization though tidal cycle, storms, floods and human activities can affect their distribution. The leaching of additives from microplastics poses major health concern and sustainable solutions target at reduction of plastics use and disposal, substitution with bioplastics and wastewater treatment innovations. Further studies on classification, detection, characterization and toxicity of microplastics are necessary to permit more effective formulation of solutions.
    Matched MeSH terms: Weather
  4. Wilson T
    Malayan Medical Journal, 1935;10:39-48.
    Matched MeSH terms: Weather
  5. Watts N, Amann M, Arnell N, Ayeb-Karlsson S, Belesova K, Boykoff M, et al.
    Lancet, 2019 11 16;394(10211):1836-1878.
    PMID: 31733928 DOI: 10.1016/S0140-6736(19)32596-6
    Matched MeSH terms: Weather
  6. Umar Hamzah, Ibrahim Komoo
    A survey to characterize seismic and ultrasonic properties of a granite weathering profile have been carried out at a roadcut slope exposure along Kuala Lumpur-Karak highway at kilometres 39.9. The terraced cut slope shows a complete weathering profile beginning from fresh grade I rock to grade VI residual soil. Together with in situ seismic measurement, rock samples have been collected for ultrasonic tests in laboratory. The range of velocities representing grades and indices of weathered rocks and soils are determined from the in situ seismic surveys. The range of ultrasonic velocities and elastic moduli are obtained from the laboratory measurements.
    Satu survei untuk mencirikan sifat seismos dan ultrasonik profil luluhawa granit telah dilakukan di singkapan potongan jalan, cerun utara lebuhraya Kuala Lumpur-Karak pada lokaliti 39.9 km. Potongan berteres ini mempamirkan satu profil luluhawa lengkap iaitu mulai batuan gred 1 yang segar hingga ke tanah baki bergred VI. Di samping pengukuran seismos secara in situ, sampel batuan juga diambil untuk dibuat pengukuran halaju ultrasonik di makmal. Julat halaju yang mewakili gred dan indeks luluhawa bagi tanah dan batuan diperolehi daripada survei seismos in situ. Julat halaju trasonik dan modulus kenyal diperolehi hasil pengukuran di makmal.
    Matched MeSH terms: Weather
  7. Ueng SK, Chan Yao-Hong, Lu WH, Chang HW
    Sains Malaysiana, 2015;44:1701-1706.
    Wind turbines are massive electrical structures. They produce large returns when illuminated by radar waves. These
    scatterings have a great impact on the operation of surveillance, air traffic control and weather radars. This paper presents
    two geometric modelling methods for reshaping wind turbine towers so that the Radar Cross Section (RCS) of wind turbines
    is reduced. In the proposed reshaping methods, bump structures are created on the surface of the conventional cylinder
    wind turbine tower. When a reshaped tower is illuminated by radar waves, the bump structures scatter incident radar
    waves into insignificant directions so that the strength of back-scattering is declined and the RCS of the wind turbine is
    decreased. The test results confirmed that the proposed methodssignificantly reduce bi-static RCS values of wind turbines.
    The proposed reshaping methods are practical, flexible and effective in alleviating the scatterings of wind turbines.
    Matched MeSH terms: Weather
  8. Tsong JL, Khor SM
    Anal Methods, 2023 Jul 06;15(26):3125-3148.
    PMID: 37376849 DOI: 10.1039/d3ay00647f
    Unpredictable natural disasters, disease outbreaks, climate change, pollution, and war constantly threaten food crop production. Smart and precision farming encourages using information or data obtained by using advanced technology (sensors, AI, and IoT) to improve decision-making in agriculture and achieve high productivity. For instance, weather prediction, nutrient information, pollutant assessment, and pathogen determination can be made with the help of new analytical and bioanalytical methods, demonstrating the potential for societal impact such as environmental, agricultural, and food science. As a rising technology, biosensors can be a potential tool to promote smart and precision farming in developing and underdeveloped countries. This review emphasizes the role of on-field, in vivo, and wearable biosensors in smart and precision farming, especially those biosensing systems that have proven with suitably complex and analytically challenging samples. The development of various agricultural biosensors in the past five years that fulfill market requirements such as portability, low cost, long-term stability, user-friendliness, rapidity, and on-site monitoring will be reviewed. The challenges and prospects for developing IoT and AI-integrated biosensors to increase crop yield and advance sustainable agriculture will be discussed. Using biosensors in smart and precision farming would ensure food security and revenue for farming communities.
    Matched MeSH terms: Weather
  9. Tang KHD
    Sci Total Environ, 2019 Feb 10;650(Pt 2):1858-1871.
    PMID: 30290336 DOI: 10.1016/j.scitotenv.2018.09.316
    PURPOSE: This paper reviews the past and future trends of climate change in Malaysia, the major contributors of greenhouse gases and the impacts of climate change to Malaysia. It also reviews the mitigation and adaptations undertaken, and future strategies to manage the impacts of regional climate change.

    METHODOLOGY: The review encompasses historical climate data comprising mean daily temperature, precipitation, mean sea level and occurrences of extreme weather events. Future climate projections have also been reviewed in addition to scholarly papers and news articles related to impacts, contributors, mitigation and adaptations in relation to climate change.

    FINDINGS: The review shows that annual mean temperature, occurrences of extreme weather events and mean sea level are rising while rainfall shows variability. Future projections point to continuous rise of temperature and mean sea level till the end of the 21st century, highly variable rainfall and increased frequency of extreme weather events. Climate change impacts particularly on agriculture, forestry, biodiversity, water resources, coastal and marine resources, public health and energy. The energy and waste management sectors are the major contributors to climate change. Mitigation of and adaptations to climate change in Malaysia revolve around policy setting, enactment of laws, formulation and implementation of plans and programmes, as well as global and regional collaborations, particularly for energy, water resources, agriculture and biodiversity. There are apparent shortcomings in continuous improvement and monitoring of the programmes as well as enforcement of the relevant laws.

    ORIGINALITY/VALUE: This paper presents a comprehensive review of the major themes of climate change in Malaysia and recommends pertinent ways forward to fill the gaps of mitigation and adaptations already implemented.

    Matched MeSH terms: Weather
  10. Tan SN, Sani D, Lim CW, Ideris A, Stanslas J, Lim CTS
    PMID: 32051689 DOI: 10.1155/2020/8068797
    Edible bird's nest (EBN) which is solidified swiftlet's saliva contains high nutritional value. It is widely consumed in countries like Malaysia, Indonesia, and Thailand. However, previous proximate analysis of Malaysia EBN was not representative of all the regions in Malaysia. In recent years, safety issues such as high nitrate and nitrite contents, presence of heavy metal, adulteration, fungal infection, and cancer cell stimulation were associated with EBN. Hence, this study aimed to determine the proximate analysis, safety profile during normal weather and hazy periods, and its effect on cancer cells stimulation in Malaysia-farmed EBN. Seven raw cleaned EBN samples were sourced from 6 different regions in Malaysia. Proximate analysis and safety profile were performed using official AOCA methods and Malaysian Standard. High protein (53.03-56.37%) and carbohydrate content (27.97-31.68%) with an acceptable level of moisture (10.8-14.04%) and ash (2.22-3.38%) were reported. A good safety profile was obtained with low nitrite and nitrate levels, with undetectable heavy metals and no significant growth of pathogenic microorganism except mould. Epidermal growth factor was detected but below the quantification level with the chicken EGF ELISA kit. The microculture tetrazolium (MTT) assay was performed for growth stimulation assessment comparing human EGF and EBN. There was no significant cell growth observed in cancer cells after EBN treatment. In conclusion, EBN Malaysia has a good nutritional profile, free of heavy metals, and an acceptable level of nitrate, nitrite, and microorganism profile except for mould contents. Furthermore, the in vitro study indicated that EBN was not associated with cancer cell growth.
    Matched MeSH terms: Weather
  11. Tajudin MABA, Khan MF, Mahiyuddin WRW, Hod R, Latif MT, Hamid AH, et al.
    Ecotoxicol Environ Saf, 2019 Apr 30;171:290-300.
    PMID: 30612017 DOI: 10.1016/j.ecoenv.2018.12.057
    Rapid urbanisation in Malaysian cities poses risks to the health of residents. This study aims to estimate the relative risk (RR) of major air pollutants on cardiovascular and respiratory hospitalisations in Kuala Lumpur. Daily hospitalisations due to cardiovascular and respiratory diseases from 2010 to 2014 were obtained from the Hospital Canselor Tuanku Muhriz (HCTM). The trace gases, PM10 and weather variables were obtained from the Department of Environment (DOE) Malaysia in consistent with the hospitalisation data. The RR was estimated using a Generalised Additive Model (GAM) based on Poisson regression. A "lag" concept was used where the analysis was segregated into risks of immediate exposure (lag 0) until exposure after 5 days (lag 5). The results showed that the gases could pose significant risks towards cardiovascular and respiratory hospitalisations. However, the RR value of PM10 was not significant in this study. Immediate effects on cardiovascular hospitalisations were observed for NO2 and O3 but no immediate effect was found on respiratory hospitalisations. Delayed effects on cardiovascular and respiratory hospitalisations were found with SO2 and NO2. The highest RR value was observed at lag 4 for respiratory admissions with SO2 (RR = 1.123, 95% CI = 1.045-1.207), followed by NO2 at lag 5 for cardiovascular admissions (RR = 1.025, 95% CI = 1.005-1.046). For the multi-pollutant model, NO2 at lag 5 showed the highest risks towards cardiovascular hospitalisations after controlling for O3 8 h mean lag 1 (RR = 1.026, 95% CI = 1.006-1.047), while SO2 at lag 4 showed highest risks towards respiratory hospitalisations after controlling for NO2 lag 3 (RR = 1.132, 95% CI = 1.053-1.216). This study indicated that exposure to trace gases in Kuala Lumpur could lead to both immediate and delayed effects on cardiovascular and respiratory hospitalisations.
    Matched MeSH terms: Weather
  12. Syahrul Affandi Saidi, Syarifah Idrus Sofia Syed Mohd Yamin, Mohd Sharizan Md Sarip, Wan Azani Mustafa
    MyJurnal
    In Malaysia, it is estimated that almost 80 percent of the world's population today used palm oil in their daily lives. Malaysia is the second country exporting palm oil, about 39 percent of world palm oil output. Besides that, Malaysia also recorded about 44 per cent of world exports, making the palm industry very important for countries other than rubber and cocoa. However, to keep the palm industry running smoothly and constantly, there are many challenges to face. One is to maintain soil fertility because the soil can affect the growth of oil palm trees. With the use of this system, it will show the condition of soil behaviour to the farmer about the treatment given. Arduino board is used in this project which it is programmed to calculate and display the level of soil condition by using temperature sensor and soil moisture sensors as an input. This sensor will detect the level of soil moisture and temperature and it is easier for farmers to monitor the soil conditions. Controlled soil conditions can improve the soil's ability to maintain the fertility of palm trees and help plant growth suit to the weather and local climate.
    Matched MeSH terms: Weather
  13. Soyiri IN, Reidpath DD, Sarran C
    Chron Respir Dis, 2013 May;10(2):85-94.
    PMID: 23620439 DOI: 10.1177/1479972313482847
    Health forecasting can improve health service provision and individual patient outcomes. Environmental factors are known to impact chronic respiratory conditions such as asthma, but little is known about the extent to which these factors can be used for forecasting. Using weather, air quality and hospital asthma admissions, in London (2005-2006), two related negative binomial models were developed and compared with a naive seasonal model. In the first approach, predictive forecasting models were fitted with 7-day averages of each potential predictor, and then a subsequent multivariable model is constructed. In the second strategy, an exhaustive search of the best fitting models between possible combinations of lags (0-14 days) of all the environmental effects on asthma admission was conducted. Three models were considered: a base model (seasonal effects), contrasted with a 7-day average model and a selected lags model (weather and air quality effects). Season is the best predictor of asthma admissions. The 7-day average and seasonal models were trivial to implement. The selected lags model was computationally intensive, but of no real value over much more easily implemented models. Seasonal factors can predict daily hospital asthma admissions in London, and there is a little evidence that additional weather and air quality information would add to forecast accuracy.
    Matched MeSH terms: Weather*
  14. Soyiri IN, Reidpath DD, Sarran C
    Int J Biometeorol, 2013 Jul;57(4):569-78.
    PMID: 22886344 DOI: 10.1007/s00484-012-0584-0
    Asthma is a chronic condition of great public health concern globally. The associated morbidity, mortality and healthcare utilisation place an enormous burden on healthcare infrastructure and services. This study demonstrates a multistage quantile regression approach to predicting excess demand for health care services in the form of asthma daily admissions in London, using retrospective data from the Hospital Episode Statistics, weather and air quality. Trivariate quantile regression models (QRM) of asthma daily admissions were fitted to a 14-day range of lags of environmental factors, accounting for seasonality in a hold-in sample of the data. Representative lags were pooled to form multivariate predictive models, selected through a systematic backward stepwise reduction approach. Models were cross-validated using a hold-out sample of the data, and their respective root mean square error measures, sensitivity, specificity and predictive values compared. Two of the predictive models were able to detect extreme number of daily asthma admissions at sensitivity levels of 76 % and 62 %, as well as specificities of 66 % and 76 %. Their positive predictive values were slightly higher for the hold-out sample (29 % and 28 %) than for the hold-in model development sample (16 % and 18 %). QRMs can be used in multistage to select suitable variables to forecast extreme asthma events. The associations between asthma and environmental factors, including temperature, ozone and carbon monoxide can be exploited in predicting future events using QRMs.
    Matched MeSH terms: Weather
  15. Siti Khadijah Che Osm, Munikanan, Vikneswaran, Hapsa Husen, Zuliziana Suif, Maidiana Othman, Nordila Ahmad, et al.
    MyJurnal
    During a disaster, the rescuer must reach the disaster area within the fastest time with the help of navigation tools. However, there might be some obstacles during the night time that make the evacuation of the victims difficult especially due to the bad weather. Hence, an attempt to produce glow-in-the-dark emergency signage to ease the evacuation process and to enhance visibility during night time is necessary. In this present study, particular emphasis is given to investigate the characteristic of photo-luminescent (PL)powder applied with polyester resin as glow-in-the-dark emergency signage. Five samples of signage were fabricated with different percentage of PL powder, i.e. 20%, 40%. 60%, 80% and 100% and mixed with 150g polyester resin. Three types of luminance test were performed to check the workability of the samples. The tests are physical appearance, one-hours illuminance test and afterglow duration tests. The result showed that the maximum lux meter reading was recorded in Sample 5 with 6 lux luminosity and provided the longest glow duration of the sample before completely off after 12-hours. Results proved that the highest percentage of the PL powder content, the longer the afterglow duration will be achieved. It also noted that the polyester resin could be a good binder of PL powder for producing the glow-in-the-dark emergency signage.
    Matched MeSH terms: Weather
  16. Siti Farhana Zakaria, Millington, Keith R.
    MyJurnal
    Polymers and organic materials that are exposed to sunlight undergo photooxidation, which leads to deterioration of their physical properties. To allow adequate performance under outdoor conditions, synthetic polymers require additives such as antioxidants and UV absorbers. A major problem with optimising polymer formulations to maximise their working life span is that accelerated weathering tests are empirical. The conditions differ significantly from real weathering situations, and samples require lengthy irradiation period. Degradation may not be apparent in the early stages of exposure, although this is when products such as hydroperoxides are formed which later cause acceleration of oxidation. A simple way of quantifying the number of free radicals presents in organic materials following exposure to light or heat is by measuring chemiluminescence (CL) emission. Most polymers emit CL when they undergo oxidative degradation, and it originates from the bimolecular reaction of macroperoxy radicals which creates an excited carbonyl.
    Matched MeSH terms: Weather
  17. Siri JG, Newell B, Proust K, Capon A
    Asia Pac J Public Health, 2016 Mar;28(2 Suppl):15S-27S.
    PMID: 26219559 DOI: 10.1177/1010539515595694
    Extreme events, both natural and anthropogenic, increasingly affect cities in terms of economic losses and impacts on health and well-being. Most people now live in cities, and Asian cities, in particular, are experiencing growth on unprecedented scales. Meanwhile, the economic and health consequences of climate-related events are worsening, a trend projected to continue. Urbanization, climate change and other geophysical and social forces interact with urban systems in ways that give rise to complex and in many cases synergistic relationships. Such effects may be mediated by location, scale, density, or connectivity, and also involve feedbacks and cascading outcomes. In this context, traditional, siloed, reductionist approaches to understanding and dealing with extreme events are unlikely to be adequate. Systems approaches to mitigation, management and response for extreme events offer a more effective way forward. Well-managed urban systems can decrease risk and increase resilience in the face of such events.
    Matched MeSH terms: Weather
  18. Shufang Fan
    Sains Malaysiana, 2017;46:2179-2186.
    In this paper, with debris flow in Zhouqu as the research object, combined with experiments such as cation exchange capacity (CEC), mineral chemical composition and water quality analysis, relation between water and salt in solid source forming debris flow was studied via soil column leaching test and soluble salt analysis, and internal characteristics of debris flow was accordingly showed. It was found that, the soil was loose, and the content of gravel and sand was high, and the content of fine particle was low. The soluble contents at the slope of the accumulation body were described as, collapsed accumulation body > landslide accumulation body, slope toe > slope top, gentle slope > steep slope, also related to length of the slope. The results indicated that accumulations released a large number of base ion after intense weathering, which migrated with water, concentrated and enriched at the slope toe. Saline soil with high salt content collapsed when encountering water and then formed mudflow, thus becoming the internal power to trigger and initiate debris flow to some extent.
    Matched MeSH terms: Weather
  19. Sharifah Sakinah, Tuan Othman, Jasronita, Jasni, Mohd Nazim, Mohtar
    MyJurnal
    Lightning is a natural phenomenon that generates a high electric field during thunderstorm. It has been
    reported that lightning strikes amid storms can occur around 100 times per second. The atmospheric
    electric field is an imperative parameter during a thunderstorm. Therefore, monitoring the electric field
    and its parameters is the best way for local lightning forecast. The electric field monitoring data can
    validate the accuracy of weather prediction in a local area from meteorology department or by using
    equipment specially designed to measure this electric field that exists when the phenomenon of lightning occurs. In this paper, the relationship between lightning, air humidity and temperature is discussed to understand the post lightning effect on these electric parameters. Additionally, the characteristics of the parameters are observed and analysed.
    Matched MeSH terms: Weather
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