排序方式: 共有51条查询结果,搜索用时 15 毫秒
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Xinquan Zhang A. Senthil Kumar Mustafizur Rahman Chandra Nath Kui Liu 《Journal of Manufacturing Processes》2012,14(3):378-387
The elliptical vibration cutting (EVC) technique has been found to be a promising technique for ultraprecision machining of various materials. In each overlapping EVC cycle, the thickness of cut (TOC) of work material, and the tool velocity get continuously varied. These two inherent phenomena, in fact, introduce transient characteristics into its cutting mechanics, which are considered to be different from the one applied for conventional cutting technique. Recently, a few theoretical models have been developed to understand the material removal mechanism with the EVC technique; however, in those studies, the transient phenomena were not considered. In the present research, an analytical force model for the orthogonal EVC process was developed in order to fully understand the EVC mechanism, and to more accurately predict the transient cutting force values. Three important factors: (i) transient TOC, (ii) transient shear angle, and (iii) transition characteristic of friction reversal were investigated and analyzed mainly based on geometric modeling and the Lee and Shaffer's slip-line solution. Mathematical evaluation shows that they may have significant influence on EVC process, and thus on its output performance. In order to validate the proposed force model, a series of low-frequency orthogonal EVC tests were conducted. The experimental transient cutting force values were compared with the predicted values calculated using the proposed model, and they are found to be in a good agreement with each other. 相似文献
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Amesho Kassian T. T. Lin Yuan-Chung Mohan S. Venkata Halder Subham Ponnusamy Vinoth Kumar Jhang Syu-Ruei 《Environmental Chemistry Letters》2023,21(1):183-230
Environmental Chemistry Letters - The global energy demand has been projected to rise over 28% by 2040, calling for more renewable resources such as lignocellulosic biomass to produce biofuels, and... 相似文献
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Rajendran Devi Sri Chidambaram Ashok Kumar Ponnusamy Senthil Venkataraman Swethaa Muthusamy Shanmugaprakash Vo Dai-Viet Nguyen Rangasamy Gayathri Vaithyanathan Vasanth Kumar Vaidyanathan Vinoth Kumar 《Environmental Chemistry Letters》2023,21(2):911-934
Environmental Chemistry Letters - Modern biomass and organic waste are becoming major, carbon-neutral sources of fine chemicals, biomolecules and fuels to replace fossil fuel products. As a... 相似文献
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Tran Thuan Van Nguyen Duyen Thi Cam Kumar Ponnusamy Senthil Din Azam Taufik Mohd Jalil Aishah Abdul Vo Dai-Viet N. 《Environmental Chemistry Letters》2022,20(2):1309-1331
Environmental Chemistry Letters - Pollution and diseases such as the coronavirus pandemic (COVID-19) are major issues that may be solved partly by nanotechnology. Here we review the synthesis of... 相似文献
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Changing the Course of Rivers in an Asian City: Linking Landscapes to Human Benefits through Iterative Modeling and Design 下载免费PDF全文
Derek Vollmer Diogo Costa Ervine Shengwei Lin Yazid Ninsalam Kashif Shaad Michaela F. Prescott Senthil Gurusamy Federica Remondi Rita Padawangi Paolo Burlando Christophe Girot Adrienne Grêt‐Regamey Joerg Rekittke 《Journal of the American Water Resources Association》2015,51(3):672-688
Concerns over water scarcity, climate change, and environmental health risks have prompted some Asian cities to invest in river rehabilitation, but deciding on the end goals of rehabilitation is a complex undertaking. We propose a multidisciplinary framework linking riparian landscape change to human well‐being, providing information relevant to decision makers, in a format that facilitates stakeholder involvement. We illustrate this through a case study of the densely settled, environmentally degraded, and flood prone Ciliwung River flowing through metropolitan Jakarta, Indonesia. Our methodology attempts to respond to this complexity through an iterative approach, strongly based on conceptualization and mathematical modeling. Nested hydrologic, hydrodynamic, and water quality models provide outputs at catchment‐, corridor‐, and localized site‐scales. Advanced 3‐D landscape modeling is used for procedural design and precise visualization of proposed changes and their impacts, as predicted by the mathematical models. Finally, participatory planning and design methods allow us to obtain critical stakeholder feedback in shaping a socially acceptable approach. Our framework aims at demonstrating that a change in paradigm in river rehabilitation is possible, and providing future scenarios that balance concerns over flooding, water quality, and ecology, with the realities of a rapidly growing megacity. 相似文献
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The toxicity and behavioural effects of neem limonoids on Cnaphalocrocis medinalis (Guenée), the rice leaffolder 总被引:2,自引:0,他引:2
Meliaceae plant products have been shown to exert pesticidal properties against a variety of insect species. In agricultural pest control programs, such products may have the potential to be used successfully as botanical insecticides. The effect of the neem (Azadirachta indica) limonoids azadirachtin, salannin, deacetylgedunin, gedunin, 17-hydroxyazadiradione and deacetylnimbin on the biology and mortality of rice leaffolder larvae was investigated. In laboratory experiments, treatment with neem limonoids suppressed leaf folding behaviour of C. medinalis. Biological parameters (larval duration, pupal duration adult longevity and fecundity) were also affected by the treatment. Azadirachtin, salannin, and deacetylgedunin showed high bioactivity at all doses, while the rest of the neem limonoids were less active, and were only biologically active at high doses. Azadirachtin was most potent in all experiments and produced almost 100% larval mortality at 1 ppm concentration. These results indicate neem limonoids affect the larval behaviour. These effects are most pronounced in early instars. 相似文献
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Water quality and phytoplankton characteristics in the Palk Bay, southeast coast of India 总被引:1,自引:0,他引:1
Sridhar R Thangaradjou T Kumar SS Kannan L 《Journal of environmental biology / Academy of Environmental Biology, India》2006,27(3):561-566
The present study was carried out to determine the water quality in terms of physicochemical characteristics and plankton distribution in the coastal waters of Kattumavadi, Palk Bay for a period of one year from April 2002 to March 2003. Air and surface water temperatures varied from 28 degrees C to 32.50 degrees C and from 27.5 to 32.0 degrees C while light extinction coefficient (LEC) varied between 0.95 and 1.85. Salinity ranged from 26.0 to 34.5 per thousand and the pH ranged between 7.95 and 8.35. Variation in dissolved oxygen content was from 4.15 to 7.18 ml(-1), and the particulate organic carbon (POC) content varied between 0.49 and 2.28 mgCl(-1). Concentrations of nutrients viz. nitrate (2.15 to 8.28 microM), nitrite (0.12 to 0.62 microM), inorganic phosphate (1.28 to 2.15 microM) and reactive silicate (5.15 to 12.52 microM) also varied independently. Chlorophyll a content ranged from 0.28 to 1.48 mg m(-3) and the primary productivity, from 4.19 to 16.08 mgCm(-3) hr(-1). The present study recorded a total of 43 species of planktonic diatoms and two species of blue-green algae. Population density of phytoplankton varied from 18,000 to 34,000 cells l(-1). Percentage composition, of the diatoms showed minimum values during the monsoon season and the maximum values during the premonsoon season. 相似文献