196 research outputs found
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Ozone trends from two decades of ground level observation in Malaysia
We examine the change in surface ozone and its precursor behavior over 20 years at four locations in western Peninsular Malaysia which have undergone urban-commercial development. Trend and correlation analyses were carried out on ozone and oxides of nitrogen observation data over the periods of 1997–2016 as well as the decadal intervals of 1997–2006 and 2007–2016. Diurnal variation composites for decadal intervals were also plotted. Significant increasing ozone concentrations were observed at all locations for the 20-year period, with a range between 0.09 and 0.21 ppb yr−1. The most urbanized location (S3) showed the highest ozone trend. Decadal intervals show that not all stations record significant increasing trends of ozone, with S1 recording decreasing ozone at a rate of −0.44 ppb yr−1 during the latter decade. Correlation analysis showed that only oxides of nitrogen ratios (NO/NO2) had significant inverse relationships with ozone at all stations corresponding to control of ozone by photostationary state reactions. The diurnal composites show that decadal difference in NO/NO2 is mostly influenced by change in nitric oxide concentrations.</jats:p
Dasar Progam Perancangan Dan Perencanaan Arsitektur (DP3A) Surakarta Pet Centre (Pendekatan pada Konsep Arsitektur Moderen Tropis)
Surakarta Pet Centre merupakan fasilitas yang diperuntukkan untuk melayani kebutuhankebutuhan hewan peliharaan, dimana dalam pelayanan tersebut mencangkup tiga fasilitas
utama yaitu seperti kegitan jual beli hewan, jasa, dan wisata edukasi. Dari fasilitas utama tersebut masing-masing terdapat wadah-wadah untuk menunjang aktifitas kegiatan yang ada di Surakarta Pet Centre, diantaranya untuk fasilitas jual beli terdapat pet jual beli hewan dan pet shop, untuk pelayanan jasa terdapat pet hotel, pet grooming, pet salon, dan pet clinic, serta untuk pelayanan edukasi terdapat pet education. Tujuan dari adanya urakarta Pet Centre sendiri salah satunya adalah menciptakan sebuah konsep perancangan desain arsitektur yang mampu mewadahi segala kegiatan yang meliputi kegiatan
pendidikan,pemenuhan kebutuhan pokok hewan, wisata kreatif, dan bisnis. Konsep arsitektur modern tropis dijadikan sebagai upaya mewujudkan bangunan yang ramah lingkungan yang bisa dinilai dari sisi lingkungan, ekonomi serta social dimana dalam tiga aspek tersebut selalu saling berkaitan untuk berkelanjutan di masa yang akan datang. Dengan adanya penerapan tersebut diharapkan bisa bermanfaat untuk kehidupan di dalam aktifitas yang ada di Surakarta Pet Centre, khususnya untuk pengguna bangunan
Analisa Pengaruh Penambahan Karbon Arang Tempurung Kelapa Dengan Variasi Mesh 10, 20, 30 Terhadap Struktur Mikro dan Tingkat Kekerasan Pada Logam Baja Hasil Reduksi Hot Rolling
The effect of adding coconut shell charcoal with variations of 10, 20, 30 to the microstructure and the level of hardness in the hot rolling steel has been investigated. Hot rolling parameters and compressive forces are made uniform. The parameter used is the reduction in thickness from 3mm to 2.85mm which is carried out at room temperature after being given anealing treatment with a temperature of 938 ÌŠC for 30 minutes in accordance with ASM Handbook No. 8. Physical properties are known based on microstructure testing and mechanical properties are known based on testing vickers micro hardness.
The results showed that the value of hardness in hot rolling was higher than before being given hot rolling treatment. The average value of hardness was given annealing treatment after hot rolling 131.4 HV, 132, 8 HV and 133.6 HV while before being given annealing before hot rolling 130.2 HV.
Keywords: Carbon steel, Carburising, Annealing, Hot Rolling, Mechanical properties
Characteristics of micro-propagated banana (Musa spp.) cultures stressed with NaCl and polyethylene glycol
The effect of NaCl and PEG was assessed on plant micro-propagation rate in banana (Musa spp.) cv., Basrai. Well micro-propagated plantlets were cultured on four different stresses of NaCl and PEG-4000 including control level: MS2b (MS0 + 3.0 mg l-1 BAP), MS2c (MS0 + 100 mol m-3 NaCl), MS2d (MS0 + 5% PEG) and MS2e (MS0 + 100 mol m-3 NaCl + 5 % PEG) for 6-weeks. Efficiency of plant micro-propagation was reduced significantly among the stressed cultures. Similarly, photosynthetic pigments like chl a was decreased non-significantly but chl b, chl ab were decreased significantly. Total carotenoids were increased in the saline as well as PEG stressed cultures. Cell size of epidermis and aerenchyma was increased (p < 0.05), while parenchyma decreased. Proline and glycinebetain contents were increased (p < 0.05) in each stressed culture but were high in MS2 than in MS3 and MS4 cultures. Meanwhile, proteins, sugars, phenolics and nitrates were observed to be in the reversed (p < 0.05) phenomena. In conclusion, NaCl treatment was observed to be most toxic than the PEG or PEG with NaCl on the banana micro-propagation.Key words: Musa spp., micro-propagation, NaCl (sodium chloride), PEG (polyethylene glycol), chlorophyll contents, proline, reducing sugars
Bromocarbons in the tropical coastal and open ocean atmosphere during the 2009 Prime Expedition Scientific Cruise (PESC-09)
Abstract. Atmospheric concentrations of very short-lived species (VSLS) bromocarbons, including CHBr3, CH2Br2, CHCl2Br, CHClBr2, and CH2BrCl, were measured in the Strait of Malacca and the South China and Sulu–Sulawesi seas during a two-month research cruise in June–July 2009. The highest bromocarbon concentrations were found in the Strait of Malacca, with smaller enhancements in coastal regions of northern Borneo. CHBr3 was the most abundant bromocarbon, ranging from 5.2 pmol mol−1 in the Strait of Malacca to 0.94 pmol mol−1 over the open ocean. Other bromocarbons showed lower concentrations, in the range of 0.8–1.3 pmol mol−1 for CH2Br2, 0.1–0.5 pmol mol−1 for CHCl2Br, and 0.1–0.4 pmol mol−1 for CHClBr2. There was no significant correlation between bromocarbons and in situ chlorophyll a, but positive correlations with both MODIS and SeaWiFS satellite chlorophyll a. Together, the short-lived bromocarbons contribute an average of 8.9 pmol mol−1 (range 5.2–21.4 pmol mol−1) to tropospheric bromine loading, which is similar to that found in previous studies from global sampling networks (Montzka et al., 2011). Statistical tests showed strong Spearman correlations between brominated compounds, suggesting a common source. Log–log plots of CHBr3/CH2Br2 versus CHBr2Cl/CH2Br2 show that both chemical reactions and dilution into the background atmosphere contribute to the composition of these halocarbons at each sampling point. We have used the correlation to make a crude estimate of the regional emissions of CHBr3 and to derive a value of 32 Gg yr−1 for the Southeast (SE) Asian region (10° N–20° S, 90–150° E). Finally, we note that satellite-derived chlorophyll a (chl a) products do not always agree well with in situ measurements, particularly in coastal regions of high turbidity, meaning that satellite chl a may not always be a good proxy for marine productivity.
We would like to thank MOSTI (Malaysian Ministry of Science, Technology and Innovation). for giving opportunities and financial support for the University of Malaya (UM) and Universiti Kebangsaan Malaysia to participate in this scientific cruise, and other Malaysian public universities and agencies who helped during sampling. The Malaysian Royal Navy is thanked for their help and assistance in all aspects of the cruise. We also thank the SHIVA European FP7 project (grant 226224), NERC, NERC-NCAS and the British Council, through a PMI2 grant, for their support. Neil Harris would like to thank NERC for his Research Fellowship; Emma Leedham and Matt Ashfold thank NERC for studentships, and Doreena Dominick, Lin Chin Yik, Fatimah Ahamad and Nur Ily Hamizah for their assistance and the Ministry of Higher Education Malaysia (KPT’s) ERGS grant ER025-2013A. Finally, we also would like to thank Universiti Kebangsaan Malaysia (UKM) for the ICONIC-2013-004 grant, MOSTI e-science grant 04-01-02-SF-0752 for Universiti Kebangsaan Malaysia (UKM), UKM GGPM-2013-080 and UKM DPP-2014-162 and GUP-2013-057 for financial support.This paper was originally published in Atmospheric Chemistry and Physics, 14, 8137-8148, doi:10.5194/acp-14-8137-2014, 201
Air quality and health impacts of vegetation and peat fires in Equatorial Asia during 2004–2015
Particulate matter (PM) emissions from vegetation and peat fires in Equatorial Asia cause poor regional air quality. Burning is greatest during drought years, resulting in strong inter-annual variability in emissions. We make the first consistent estimate of the emissions, air quality and public health impacts of Equatorial Asian fires during 2004–2015. The largest dry season (August—October) emissions occurred in 2015, with PM emissions estimated as 9.4 Tg, more than triple the average dry season emission (2.7 Tg). Fires in Sumatra and Kalimantan caused 94% of PM emissions from fires in Equatorial Asia. Peat combustion in Indonesian peatlands contributed 45% of PM emissions, with a greater contribution of 68% in 2015. We used the WRF-chem model to simulate dry season PM for the 6 biggest fire years during this period (2004, 2006, 2009, 2012, 2014, 2015). The model reproduces PM concentrations from a measurement network across Malaysia and Indonesia, suggesting our PM emissions are realistic. We estimate long-term exposure to PM resulted in 44 040 excess deaths in 2015, with more than 15 000 excess deaths annually in 2004, 2006, and 2009. Exposure to PM from dry season fires resulted in an estimated 131 700 excess deaths during 2004–2015. Our work highlights that Indonesian vegetation and peat fires frequently cause adverse impacts to public health across the region
Carbon emissions from oil palm induced forest and peatland conversion in sabah and Sarawak, Malaysia
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The palm oil industry is one of the major producers of vegetable oil in the tropics. Palm oil is used extensively for the manufacture of a wide variety of products and its production is increasing by around 9% every year, prompted largely by the expanding biofuel markets. The rise in annual demand for biofuels and vegetable oil from importer countries has caused a dramatic increase in the conversion of forests and peatlands into oil palm plantations in Malaysia. This study assessed the area of forests and peatlands converted into oil palm plantations from 1990 to 2018 in the states of Sarawak and Sabah, Malaysia, and estimated the resulting carbon dioxide (CO2) emissions. To do so, we analyzed multitemporal 30-m resolution Landsat-5 and Landsat-8 images using a hybrid method that combined automatic image processing and manual analyses. We found that over the 28-year period, forest cover declined by 12.6% and 16.3%, and the peatland area declined by 20.5% and 19.1% in Sarawak and Sabah, respectively. In 2018, we found that these changes resulted in CO2 emissions of 0.01577 and 0.00086 Gt CO2-C yr−1, as compared to an annual forest CO2 uptake of 0.26464 and 0.15007 Gt CO2-C yr−1, in Sarawak and Sabah, respectively. Our assessment highlights that carbon impacts extend beyond lost standing stocks, and result in substantial direct emissions from the oil palm plantations themselves, with 2018 oil palm plantations in our study area emitting up to 4% of CO2 uptake by remaining forests. Limiting future climate change impacts requires enhanced economic incentives for land uses that neither convert standing forests nor result in substantial CO2 emissions
Identification of field caught Anopheles gambiae s.s. and Anopheles arabiensis by TaqMan single nucleotide polymorphism genotyping
BACKGROUND: Identification of Anopheles gambiae s.s. and Anopheles arabiensis from field-collected Anopheles gambiae s.l. is often necessary in basic and applied research, and in operational control programmes. The currently accepted method involves use of standard polymerase chain reaction amplification of ribosomal DNA (rDNA) from the 3' 28S to 5' intergenic spacer region of the genome, and visual confirmation of amplicons of predicted size on agarose gels, after electrophoresis. This report describes development and evaluation of an automated, quantitative PCR method based upon TaqManâ„¢ single nucleotide polymorphism (SNP) genotyping. METHODS: Standard PCR, and TaqMan SNP genotyping with newly designed primers and fluorophore-labeled probes hybridizing to sequences of complementary rDNA specific for either An. gambiae s.s. or An. arabiensis, were conducted in three experiments involving field-collected An. gambiae s.l. from western Kenya, and defined laboratory strains. DNA extraction was from a single leg, sonicated for five minutes in buffer in wells of 96-well PCR plates. RESULTS: TaqMan SNP genotyping showed a reaction success rate, sensitivity, and species specificity comparable to that of standard PCR. In an extensive field study, only 29 of 3,041 (0.95%) were determined to be hybrids by TaqMan (i.e., having rDNA sequences from both species), however, all but one were An. arabiensis by standard PCR, suggesting an acceptably low (ca. 1%) error rate for TaqMan genotyping in mistakenly identifying species hybrids. CONCLUSION: TaqMan SNP genotyping proved to be a sensitive and rapid method for identification of An. gambiae s.l. and An. arabiensis, with a high success rate, specific results, and congruence with the standard PCR method
New estimate of particulate emissions from Indonesian peat fires in 2015
Indonesia contains large areas of peatland that have been drained and cleared of natural vegetation, making them susceptible to burning. Peat fires emit considerable amounts of carbon dioxide, particulate matter (PM) and other trace gases, contributing to climate change and causing regional air pollution. However, emissions from peat fires are uncertain, due to uncertainties in emission factors and fuel consumption. We used the Weather Research and Forecasting model with chemistry and measurements of PM concentrations to constrain PM emissions from Indonesian fires during 2015, one of the largest fire seasons in recent decades.Published versio
The burden and risk factors of Sexually Transmitted Infections and Reproductive Tract Infections among pregnant women in Zimbabwe
<p>Abstract</p> <p>Background</p> <p>Sexually transmitted infections (STIs) and Reproductive tract infections (RTIs) are responsible for high morbidity among women. We aim to quantify the magnitude of the burden and risk factors of STI/RTI s among pregnant women in Zimbabwe.</p> <p>Methods</p> <p>A cross sectional study of pregnant women enrolled at 36 weeks of gestation from the national PMTCT program. Study was conducted from three peri-urban clinics around Harare Zimbabwe offering maternal and child health services.</p> <p>Results</p> <p>A total of 691 pregnant women were enrolled. Prevalence of HSV was (51.1%), HIV (25.6%) syphilis (1.2%), <it>Trichomonas vaginalis </it>(11.8%), bacterial vaginosis (32.6%) and Candidiasis (39.9%). Seven percent of the women had genital warts, 3% had genital ulcers and 28% had an abnormal vaginal discharge. Prevalence of serological STIs and vaginal infections were 51% and 64% respectively.</p> <p>Risk factors for a positive serologic STI were increasing age above 30 years, polygamy and multigravid; adjusted OR (95% CI) 2.61(1.49-4.59), 2.16(1.06-4.39), 3.89(1.27-11.98) respectively, partner taking alcohol and number of lifetime sexual partners. For vaginal infections it was age at sexual debut; OR (95% CI) 1.60(1.06-2.42). More than 25% of the women reported previous STI treatment. Fifty two percent reported ever use of condoms and 65% were on oral contraceptives. Mean age gap for sexual partners was 6.3 years older.</p> <p>Conclusions</p> <p>There is a high morbidity of STI/RTIs in this cohort. There is need to continuously screen, counsel, treat and monitor trends of STI/RTIs to assess if behaviour changes lead to reduction in infections and their sustainability.</p
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