Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries,Malaysia     

Aziz Ghaderpour  Khairul Nazrin Mohd Nasori  Li Lee Chew  Ving Ching Chong  Kwai Lin Thong  Lay Ching Chai 《Marine pollution bulletin》2014

The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public.  相似文献   

Statistical distributions of extreme dry spell in Peninsular Malaysia   总被引：1，自引：1，他引：0  

Wan Zawiah Wan Zin  Abdul Aziz Jemain 《Theoretical and Applied Climatology》2010,102(3-4):253-264

Statistical distributions of annual extreme (AE) series and partial duration (PD) series for dry-spell event are analyzed for a database of daily rainfall records of 50 rain-gauge stations in Peninsular Malaysia, with recording period extending from 1975 to 2004. The three-parameter generalized extreme value (GEV) and generalized Pareto (GP) distributions are considered to model both series. In both cases, the parameters of these two distributions are fitted by means of the L-moments method, which provides a robust estimation of them. The goodness-of-fit (GOF) between empirical data and theoretical distributions are then evaluated by means of the L-moment ratio diagram and several goodness-of-fit tests for each of the 50 stations. It is found that for the majority of stations, the AE and PD series are well fitted by the GEV and GP models, respectively. Based on the models that have been identified, we can reasonably predict the risks associated with extreme dry spells for various return periods.  相似文献   

An organic geochemical investigation on organic rich sediments from two Neogene formations in the Klias Peninsula area,West Sabah,Malaysia     

Amer M. Burgan  Che Aziz Ali 《中国地球化学学报》2009,28(3):264-270

Twenty organic rich outcrop samples from the Belait and Setap Shale formations in the Klias Peninsula area, West Sabah, were analysed by means of organic petrology and geochemical techniques. The aims of this study are to assess the type of organic matter, thermal maturity and established source rock characterization based primarily on Rock-Eval pyrolysis data. The shales of the Setap Shale Formation have TOC values varying from 0.6 wt%–1.54 wt% with a mean hydrogen index (HI) of 60.1 mg/g, whereas the shal...  相似文献   

Biostratigraphy and sedimentology of the Fluviatile Untere Serie (Early and Middle Miocene) in the central part of the North Alpine Foreland Basin: implications for palaeoenvironment and climate     

J. Prieto  M. Böhme  H. Maurer  K. Heissig  H. Abdul Aziz 《International Journal of Earth Sciences》2009,98(7):1767-1791

The Early to Middle Miocene Fluviatile Untere Serie lithostratigraphic unit of the Upper Freshwater Molasse (UFM) in the North Alpine Foreland Basin (NAFB) crops out in a 40 m long section at Untereichen-Altenstadt (central part of the NAFB). This section yields a unique superposition of two vertebrate assemblages belonging to different biostratigraphic units: early part OSM C + D (Karpatian) and OSM E (Early Badenian). Detailed taxonomic analyses reveal different diversity patterns in the two assemblages. Nine small mammal and six ectothermic vertebrate taxa occur in the older level UA 540 m, while 20 small mammal and 23 ectothermic vertebrate taxa are recorded for the younger level UA 565 m. From the latter locality comes a small-sized representative of the biostratigraphically significant Megacricetodon lappi lineage. This evolutionary level has not been documented previously for the eastern part of the NAFB. Bioclimatic analysis combined with lithofacies and architectural element analysis indicates that significant changes in the fluvial sedimentation style, surface-water runoff and tectonics occurred between the Early Karpatian and Early Badenian. A meandering fluvial system (marly unit) is erosively overlain by sandy braided river deposits (sandy unit). Overbank deposits of the marly unit revealed that the older vertebrate fossil assemblage (UA 540 m) is deposited in an animal burrow that was presumably produced by owls. Both reptilian and mammalian taxa are indicative of a relatively open environment and dry, probably semi-arid climate. Conversely, vertebrates from the sandy unit (UA 565 m), which are accumulated in channel fill deposits, suggest closed as well as open habitats with a subtropical humid climate and mean annual rainfall of about 1,000 mm. According to the sequence stratigraphic analysis the marly unit is interpreted as a highstand-system-tract of the TB 2.2 global 3rd order sequence. The new results add support to the hypothesis that the erosional unconformity between both sedimentary units spanning the Karpatian-Badenian transition corresponds to the pre-Riesian hiatus, which has been interpreted as part of the Styrian Tectonic Phase, and was previously identified only in the eastern and northeastern part of the NAFB. The biostratigraphic data further indicate that this hiatus lasted longer in the eastern than in the central part of the basin.  相似文献   

Second order secular planetary theory for the four major planets     

Osman M. Kamel  Abdel Aziz Bakry 《Earth, Moon, and Planets》1984,31(2):123-134

We generalize our results of a second order Jupiter-Saturn planetary theory to be applicable for the case of the four major planets.We use the Von Zeipel method and we neglect powers higher than the third with respect to the eccentricities and sines of the inclinations in our expansions. We consider the critical terms as the only periodic terms.  相似文献   

A Neural-Network Approach to the Determination of Aquifer Parameters   总被引：8，自引：0，他引：8  

Abd. Rashid Abd. Aziz  Kau-Fui Vincent Wong 《Ground water》1992,30(2):164-166

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Calculation of Well Index for Nonconventional Wells on Arbitrary Grids     

Christian Wolfsteiner  Louis J. Durlofsky  Khalid Aziz 《Computational Geosciences》2003,7(1):61-82

Wells are seldom modeled explicitly in large scale finite difference reservoir simulations. Instead, the well is coupled to the reservoir through the use of a well index, which relates wellbore flow rate and pressure to grid block quantities. The use of an accurate well index is essential for the detailed modeling of nonconventional wells; i.e., wells with an arbitrary trajectory or multiple branches. The determination of a well index for such problems is complicated, particularly when the simulation grid is irregular or unstructured. In this work, a general framework for the calculation of accurate well indices for general nonconventional wells on arbitrary grids is presented and applied. The method entails the use of an accurate semianalytical well model based on Green's functions as a reference single phase flow solution. This result is coupled with a finite difference calculation to provide an accurate well index for each grid block containing a well segment. The method is demonstrated on a number of homogeneous example cases involving deviated, horizontal and multilateral wells oriented skew to the grid. Both Cartesian and globally unstructured multiblock grids are considered. In all these cases, the method is shown to provide results that are considerably more accurate compared to results using standard procedures. The method is also applied to heterogeneous problems involving horizontal wells, where it is shown to be capable of approximating the effects of subgrid heterogeneity in coarse finite difference models.  相似文献   

Effects of some environmental parameters on the reproduction and development of a tropical marine harpacticoid copepod Nitocra affinis f. californica Lang     

Hazel Matias-Peralta  Fatimah Md. Yusoff  Mohamed Shariff  Aziz Arshad 《Marine pollution bulletin》2005,51(8-12):722

The effects of salinity, temperature, and light conditions on the reproduction and development of harpacticoid copepod, Nitocra affinis f. californica under controlled laboratory conditions were determined. Seven different salinity levels (5, 10, 15, 20, 25, 30, 35 ppt), four temperatures (20, 25, 30, 35 °C), three different light intensities (25, 56, 130 μmol m⁻² s⁻¹) and photoperiods (24 h:0 h, 1 h:23 h, 12 h:12 h LD cycle) were employed in this study. The highest (p < 0.05) overall reproduction and fastest development time were achieved by copepods reared under 30–35 ppt salinity. The optimum temperature required for the maximum reproduction was 30 °C while under 30 °C and 35 °C the copepod development time was shortest (p < 0.05) compared to other temperature levels. The overall reproduction was highest (p < 0.05) and development rate of N. affinis was shortest (p < 0.05) under lowest light intensity (25 μmol m⁻² s⁻¹). Continuous light (24 h:0 h LD) inhibited the egg production while, continuous darkness (1 h:23 h LD) and 12 h:12 h LD significantly favoured the overall reproductive activity of the female. Photoperiods 1 h:23 h and 12 h:12 h LD yielded highest total (p < 0.05) offspring female⁻¹ coupled with highest (p < 0.05) survival percentage. This study illustrated that although N. affinis can tolerate wide range of environmental conditions, prolonged exposure to subnormal environments affect its reproduction and development. This study showed that this species can be mass cultured for commercial purposes and has a potential to be used for toxicity studies due to its high reproductive performance fast development and a wide range of tolerance to environmental conditions.  相似文献   

基于Photomod 3.11制作数字正射影像     

陈晓玲  江万寿  郝中豫  吴忠宜 《测绘信息与工程》2007,32(5):27-29

介绍了俄罗斯的数字摄影测量系统Photomod 3.11,分析了采用比例尺为1∶20 000的航片制作数字正射影像的流程,试验表明其能满足1∶5 000地形图的精度要求.  相似文献   

An efficient Co-ZSM-5 catalyst for the abatement of volatile organics in air: effect of the synthesis protocol     

A. Aziz  M. Sajjad  M. Kim  K. S. Kim 《International Journal of Environmental Science and Technology》2018,15(4):707-718

Co supported on ZSM-5 (Co-ZSM-5) catalysts was synthesized by wet ion exchange (WIE), impregnation (IM), and in situ hydrothermal (IHT) methods. Their adsorptive catalytic activities for the removal of VOC’s [Benzene, Toluene, Ethylbenzene and Toluene (BTEX)] in air were tested. The physicochemical properties were investigated by XRD, FTIR, SEM, XPS, and low-temperature N₂ adsorption. The results indicate that the catalytic performance of Co-ZSM-5 for VOC’s abatement is effective and the synthesis methods reasonably influence the catalytic activity of Co-ZSM-5. Among three samples prepared by three different methods, the catalyst synthesized by the hydrothermal method possesses the highest adsorptive catalytic activity for BTEX oxidation. The optimized contact time was 60 min. The catalytic activities of the prepared catalysts are varied in the order of IHT > IM > WIE based on the combined removal capacity 59.24 > 34.46 > 23.82 (mg/g). For the Co-ZSM-5 WIE catalysts, the procedure has an evident effect on their catalytic performance. For example, the WIE catalysts prepared with cobalt chloride (II) by ion exchange have a higher acidity and surface area than the catalyst prepared with cobalt chloride (II) by impregnation method but less cobalt content. The excellent performance of IHT catalysts may be endorsed to the better availability of the oxidized form (Co³⁺), due to high content, higher surface area and acidity. Moreover, the Co-ZSM-5 catalyst synthesized by the IHT method shows high stability after being used.  相似文献