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1.
Med J Malaysia ; 79(Suppl 1): 122-127, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38555896

RESUMO

INTRODUCTION: The SARS-CoV-2 virus, responsible for the global COVID-19 pandemic and its associated high morbidity and mortality, continues to be a significant public health concern. This study investigates the influence of temperature variables on COVID-19 transmission in Terengganu, Malaysia, which, despite having experienced a comparatively lower number of cases, presents a unique environment for understanding how temperature factors may play a critical role in virus transmission dynamics. MATERIALS AND METHODS: We conducted a descriptive analysis to assess the spatial distribution of COVID-19 cases in our study area. To explore the relationship between temperature variables and COVID-19 transmission, we employed Pearson correlation analysis, examining the correlations between daily average, minimum, and maximum temperature data and the temporal distribution of COVID-19 cases as reported by the Ministry of Health, Malaysia. This approach allowed us to comprehensively investigate the impact of weather on the transmission dynamics of COVID-19. RESULTS: Our findings reveal a noteworthy correlation (p<0.05) between average and maximum temperatures and COVID-19 transmission, highlighting the influence of weather on disease dynamics. Notably, exceptions were observed in the Hulu Terengganu district, where fewer than 10 cases occurred in each sub-district throughout the study period, warranting special consideration. CONCLUSION: In summary, our study highlights the significance of temperature in shaping COVID-19 transmission. This stresses the importance of including weather variables in pandemic strategies. We also suggest comparing various cities to broaden our understanding of how weather affects disease spread, aiding future public health efforts.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Temperatura , SARS-CoV-2 , Saúde Pública , Pandemias , Malásia/epidemiologia
2.
Biomed Res Int ; 2020: 2734135, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32149095

RESUMO

The release of wastewater from textile dyeing industrial sectors is a huge concern with regard to pollution as the treatment of these waters is truly a challenging process. Hence, this study investigates the triazo bond Direct Blue 71 (DB71) dye decolorization and degradation dye by a mixed bacterial culture in the deficiency source of carbon and nitrogen. The metagenomics analysis found that the microbial community consists of a major bacterial group of Acinetobacter (30%), Comamonas (11%), Aeromonadaceae (10%), Pseudomonas (10%), Flavobacterium (8%), Porphyromonadaceae (6%), and Enterobacteriaceae (4%). The richest phylum includes Proteobacteria (78.61%), followed by Bacteroidetes (14.48%) and Firmicutes (3.08%). The decolorization process optimization was effectively done by using response surface methodology (RSM) and artificial neural network (ANN). The experimental variables of dye concentration, yeast extract, and pH show a significant effect on DB71 dye decolorization percentage. Over a comparative scale, the ANN model has higher prediction and accuracy in the fitness compared to the RSM model proven by approximated R 2 and AAD values. The results acquired signify an efficient decolorization of DB71 dye by a mixed bacterial culture.


Assuntos
Compostos Azo/farmacologia , Redes Neurais de Computação , Descoloração da Água/métodos , Bactérias/classificação , Biodegradação Ambiental , Carbono/metabolismo , Concentração de Íons de Hidrogênio , Metagenômica , Nitrogênio/metabolismo
3.
Environ Monit Assess ; 191(4): 232, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30900076

RESUMO

This study was conducted to determine the effects of rice husk ash (RHA) and Fe-coated rice husk ash (Fe-RHA) on the bioavailability and mobility of As, Cd, and Mn in mine tailings. The amendments were added to the tailings at 0, 5, 10, or 20% (w/w) and the mixtures were incubated for 0, 7, 15, 30, 45, and 60 days. The CaCl2 extractable As, Cd, and Mn in the amended tailings were determined at each interval of incubation period. In addition, the tailings mixture was leached with simulated rain water (SRW) every week from 0 day (D 0) until day 60 (D 60). The results showed that both RHA and Fe-RHA application significantly decreased the CaCl2-extractable Cd and Mn but increased that of As in the tailings throughout the incubation period. Consequently, addition of both RHA and Fe-RHA leached out higher amount of As from the tailings but decreased Cd and Mn concentration compared to the controls. The amount of As leached from the Fe-RHA-amended tailings was less than that from RHA-amended tailings. Application of both RHA and Fe-RHA could be an effective way in decreasing the availability of cationic heavy metals (Cd and Mn) in the tailings but these amendments could result in increasing the availability of anionic metalloid (As). Therefore, selection of organic amendments to remediate metal-contaminated tailings must be done with great care because the outcomes might be different among the elements.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , Arsênio/análise , Arsênio/química , Disponibilidade Biológica , Cádmio/análise , Cádmio/química , Carvão Vegetal/química , Ouro , Manganês/análise , Manganês/química , Oryza
4.
Bioinorg Chem Appl ; 2017: 7914714, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28420949

RESUMO

This study aims to produce optimized biochar from oil palm empty fruit bunches (OPEFB), as a green, low cost adsorbent for uptake of zinc from aqueous solution. The impact of pyrolysis conditions, namely, highest treatment temperature (HTT), heating rate (HR), and residence time (RT) on biochar yield and adsorption capacity towards zinc, was investigated. Mathematical modeling and optimization of independent variables were performed employing response surface methodology (RSM). HTT was found to be the most influential variable, followed by residence time and heating rate. Based on the central composite design (CCD), two quadratic models were developed to correlate three independent variables to responses. The optimum production condition for OPEFB biochar was found as follows: HTT of 615°C, HR of 8°C/min, and RT of 128 minutes. The optimum biochar showed 15.18 mg/g adsorption capacity for zinc and 25.49% of yield which was in agreement with the predicted values, satisfactory. Results of the characterization of optimum product illustrated well-developed BET surface area and porous structure in optimum product which favored its sorptive ability.

5.
Waste Manag Res ; 32(4): 331-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24643171

RESUMO

Biochar has received great attention recently due to its potential to improve soil fertility and immobilize contaminants as well as serving as a way of carbon sequestration and therefore a possible carbon sink. In this work, a series of biochars were produced from empty fruit bunch (EFB) and rice husk (RH) by slow pyrolysis at different temperatures (350, 500, and 650°C) and their physicochemical properties were analysed. The results indicate that porosity, ash content, electrical conductivity (EC), and pH value of both EFB and RH biochars were increased with temperature; however, yield, cation exchange capacity (CEC), and H, C, and N content were decreased with increasing pyrolysis temperature. The Fourier transform IR spectra were similar for both RH and EFB biochars but the functional groups were more distinct in the EFB biochar spectra. There were reductions in the amount of functional groups as pyrolysis temperature increased especially for the EFB biochar. However, total acidity of the functional groups increased with pyrolysis temperature for both biochars.


Assuntos
Carvão Vegetal/química , Frutas/química , Oryza/química , Resíduos Sólidos/análise , Carvão Vegetal/análise , Temperatura Alta , Espectroscopia de Infravermelho com Transformada de Fourier
6.
J Environ Sci Health B ; 47(2): 144-51, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22251214

RESUMO

This study was carried out to determine the sorption-desorption, degradation and leaching of napropamide in selected Malaysian soils. The sorption capacities of the selected Malaysian soils for napropamide were the following in descending order: Linau > Teringkap > Gunung Berinchang > Jambu > Rudua > Baging soil. The results indicate that napropamide degradation decreased with increasing soil sorption capacity. Napropamide was leached out earlier in the Baging soil than the other soils. Overall, the application of napropamide in the selected Malaysian soils would not pose a threat to the environment except in soil with low organic matter and clay content and high hydraulic conductivity, such as the Baging soil.


Assuntos
Monitoramento Ambiental/métodos , Herbicidas/química , Naftalenos/química , Poluentes do Solo/química , Solo/química , Adsorção , Herbicidas/análise , Malásia , Naftalenos/análise , Solo/análise , Poluentes do Solo/análise
7.
Bioresour Technol ; 102(22): 10759-62, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21958525

RESUMO

This study was undertaken to compare the chemical properties and yields of pineapple leaf residue (PLR) char produced by field burning (CF) with that produced by a partial combustion of air-dried PLR at 340 °C for 3 h in a furnace (CL). Higher total C, lignin content, and yield from CL as well as the presence of aromatic compounds in the Fourier Transform Infrared spectra of the char produced from CL suggest that the CL process was better in sequestering C than was the CF process. Although the C/N ratio of char produced from CL was low indicating a high N content of the char, the C in the char produced from CL was dominated by lignin suggesting that the decomposition of char produced from CL would be slow. To sequester C by char application, the PLR should be combusted in a controlled process rather than by burning in the field.


Assuntos
Ananas/química , Biotecnologia/métodos , Sequestro de Carbono , Carvão Vegetal/química , Incêndios , Folhas de Planta/química , Carbono/análise , Dióxido de Carbono/análise , Monóxido de Carbono/análise , Celulose/análise , Condutividade Elétrica , Concentração de Íons de Hidrogênio , Lignina/análise , Nitrogênio/análise , Oxigênio/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
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