排序方式: 共有23条查询结果,搜索用时 15 毫秒
1.
C.V. Srinivas R. Venkatesan V. Yesubabu C. Nagaraju K.M. Somayajai P. Chellapandi Baldev Raj 《Atmospheric environment (Oxford, England : 1994)》2010,44(24):2846-2864
A mesoscale atmospheric model PSU/NCAR MM5 is used to provide operational weather forecasts for a nuclear emergency response decision support system on the southeast coast of India. In this study the performance of the MM5 model with assimilation of conventional surface and upper-air observations along with satellite derived 2-d surface wind data from QuickSCAT sources is examined. Two numerical experiments with MM5 are conducted: one with static initialization using NCEP FNL data and second with dynamic initialization by assimilation of observations using four dimensional data assimilation (FDDA) analysis nudging for a pre-forecast period of 12 h. Dispersion simulations are conducted for a hypothetical source at Kalpakkam location with the HYSPLIT Lagrangian particle model using simulated wind field from the above experiments. The present paper brings out the differences in the atmospheric model predictions and the differences in dispersion model results from control and assimilation runs. An improvement is noted in the atmospheric fields from the assimilation experiment which has led to significant alteration in the trajectory positions, plume orientation and its distribution pattern. Sensitivity tests using different PBL and surface parameterizations indicated the simple first order closure schemes (Blackadar, MRF) coupled with the simple soil model have given better results for various atmospheric fields. The study illustrates the impact of the assimilation of the scatterometer wind and automated weather stations (AWS) observations on the meteorological model predictions and the dispersion results. 相似文献
2.
Venkatesan G. Subramani T. Karunanidhi D. Sathya U. Li Peiyue 《Environmental science and pollution research international》2021,28(15):18552-18552
Environmental Science and Pollution Research - A Correction to this paper has been published: https://doi.org/10.1007/s11356-021-13406-7 相似文献
3.
Sorakka Ponnappan Venkatesan B. Keshava Kalyan G. Gopinath M. Purusothaman J. Hemanandh 《环境质量管理》2023,33(1):53-59
One of the important components of a car to control the temperature of a car's engine is the radiator. To increase the heat absorption capacity of the coolant/fluid used in the radiator with minimum pumping power, innovative fluids called nanofluids have become the main area of research these days. Therefore, with the development of new technologies in the field of “nano-materials” and “nano-fluids,” the physical and chemical properties of coolant/fluid can be improved which in turn improves the radiator and engine efficiency, and reduces radiator weight and size. In this article, the heat transfer by forced convection in nanofluids based on Al2O3 and SiC was studied experimentally and compared to that of base fluid in an automotive radiator. The nanofluid is mixed with ethylene glycol and the fluid is prepared by the sonication method. The nanofluids were prepared by varying the nanomaterials and the amounts of nanomaterials in the base fluid and their heat transfer performance in the radiator was analyzed using ANSYS FLUENT software. Approximately 15% and 12% increase in radiator efficiency by using Al2O3 mixed nanofluid and SiC mixed nanofluid, respectively. 相似文献
4.
Venkatesan G. Subramani T. Karunanidhi D. Sathya U. Li Peiyue 《Environmental science and pollution research international》2021,28(15):18539-18551
Environmental Science and Pollution Research - In the present study, impact of precipitation disparity on groundwater level fluctuation was carried out in Vellore district, Tamil Nadu, India, using... 相似文献
5.
Venkatesan Hariram Rose Godwin John John Vijayarengan Preethi Sivamani Seralathan Krishnan Jagannathan Thomai Micha Premkumar 《Environmental science and pollution research international》2021,28(45):63464-63479
Environmental Science and Pollution Research - Biodiesel is one among the recent developments in the field of renewable energy research. To enhance the combustion characteristics of compression... 相似文献
6.
Athiyanam Venkatesan Ramya Manoj Balachandran 《Frontiers of Environmental Science & Engineering》2022,16(3):27
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S. Abdul Majeed K. S. N. Nambi G. Taju S. Vimal C. Venkatesan A. S. Sahul Hameed 《Environmental science and pollution research international》2014,21(23):13539-13550
The cytotoxicity, genotoxicity and oxidative stress of malachite green (MG) was investigated using the fish Channa striata kidney (CSK) and Channa striata gill (CSG) cell lines. Five concentrations ranging from 0.001 to 10 μg mL?1 were tested in three independent experiments. Cytotoxicity was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Rhodamine 123 and Alamar Blue. The mitochondrial changes and apoptosis of MG-exposed cells were observed by Rhodamine 123 and acridine orange/ethidium bromide (AO/EB) staining, respectively. In vitro potential DNA damaging effect of MG was tested using comet assay. Mitochondrial damage, apoptosis and DNA fragmentation increased in a concentration-dependent manner. Additionally, DNA electrophoretic mobility experiments were carried out to study the binding effect of MG to double-stranded DNA (dsDNA) of cells. DNA shift mobility experiments showed that MG is capable of strongly binding to linear dsDNA causing its degradation. Biochemical parameters such as lipid peroxidation (MDA), catalase (CAT) activity and reduced glutathione (GSH) levels were evaluated after exposure to MG. In CSK and CSG cell lines exposed to MG for 48 h, a significant increase in lipid peroxidation, which might be associated with decreased levels of reduced glutathione and catalase activity in these cell lines (p?0.001), was observed. 相似文献
9.
Shruti Pavagadhi Raghu Betha Shriram Venkatesan Rajasekhar Balasubramanian Manoor Prakash Hande 《Environmental science and pollution research international》2013,20(4):2569-2578
Air particulate matter (PM) samples were collected in Singapore from 21 to 29 October 2010. During this time period, a severe regional smoke haze episode lasted for a few days (21–23 October). Physicochemical and toxicological characteristics of both haze and non-haze aerosols were evaluated. The average mass concentration of PM2.5 (PM with aerodynamic diameter of ≤2.5 μm) increased by a factor of 4 during the smoke haze period (107.2 μg/m3) as compared to that during the non-smoke haze period (27.0 μg/m3). The PM2.5 samples were analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) listed by the United States Environmental Protection Agency and 10 transition metals. Out of the seven PAHs known as potential or suspected carcinogens, five were found in significantly higher levels in smoke haze aerosols as compared to those in the background air. Metal concentrations were also found to be higher in haze aerosols. Additionally, the toxicological profile of the PM2.5 samples was evaluated using a human epithelial lung cell line (A549). Cell viability and death counts were measured after a direct exposure of PM2.5 samples to A459 cells for a period of 48 h. The percentage of metabolically active cells decreased significantly following a direct exposure to PM samples collected during the haze period. To provide further insights into the toxicological characteristics of the aerosol particles, glutathione levels, as an indirect measure of oxidative stress and caspase-3/7 levels as a measure of apoptotic death, were also evaluated. 相似文献
10.
Li X Wang T Sattayatewa C Venkatesan D Noll KE Pagilla KR Moschandreas DJ 《Journal of the Air & Waste Management Association (1995)》2011,61(8):872-881
Odor emission rates are commonly measured in the laboratory or occasionally estimated with inverse modeling techniques. A modified inverse modeling approach is used to estimate source emission rates inside of a postdigestion centrifuge building of a water reclamation plant. Conventionally, inverse modeling methods divide an indoor environment in zones on the basis of structural design and estimate source emission rates using models that assume homogeneous distribution of agent concentrations within a zone and experimentally determined link functions to simulate airflows among zones. The modified approach segregates zones as a function of agent distribution rather than building design and identifies near and far fields. Near-field agent concentrations do not satisfy the assumption of homogeneous odor concentrations; far-field concentrations satisfy this assumption and are the only ones used to estimate emission rates. The predictive ability of the modified inverse modeling approach was validated with measured emission rate values; the difference between corresponding estimated and measured odor emission rates is not statistically significant. Similarly, the difference between measured and estimated hydrogen sulfide emission rates is also not statistically significant. The modified inverse modeling approach is easy to perform because it uses odor and odorant field measurements instead of complex chamber emission rate measurements. 相似文献