The Kinematics Research of Elliptical Vibration Polishing Based on the Vibration Parameter Optimization

2016 ◽  
Vol 679 ◽  
pp. 7-14
Author(s):  
Dun Lan Song ◽  
Ji Zhao ◽  
Shi Jun Ji ◽  
Xin Wang

Polishing, the last manufacturing procedure in the process of optics manufacturing, has been restricted by the existed contradictory propositions of efficiency and accuracy. As a result, a variety of new combined processing techniques put forward by researchers in many countries. While, elliptical vibration polishing (short as EVP) well considers efficiency and accuracy in machining. This paper focuses on the kinematics research of EVP tools, and proves the superiority of EVP through the vibration parameter optimization. Perfect tool path gets by the impact analysis of phase difference, frequency ratio and amplitude of the polishing tool. Meanwhile the optimum frequency for EVP is studied from the cost and efficiency perspective. The simulations reveal that the perfect tool path will be obtained in the following situations: phase difference at 90°, frequency ratio at 0.909, adjusts the tool vibration amplitude in consideration of minimum curvature radius in polishing area, and appropriately select the vibration frequency.

The university is considered one of the engines of growth in a local economy or its market area, since its direct contributions consist of 1) employment of faculty and staff, 2) services to students, and supply chain links vendors, all of which define the University’s Market area. Indirect contributions consist of those agents associated with the university in terms of community and civic events. Each of these activities represent economic benefits to their host communities and can be classified as the economic impact a university has on its local economy and whose spatial market area includes each of the above agents. In addition are the critical links to the University, which can be considered part of its Demand and Supply chain. This paper contributes to the field of Public/Private Impact Analysis, which is used to substantiate the social and economic benefits of cooperating for economic resources. We use Census data on Output of Goods and Services, Labor Income on Salaries, Wages and Benefits, Indirect State and Local Taxes, Property Tax Revenue, Population, and Inter-Industry to measure economic impact (Implan, 2016).


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
MATHALA JULIET GUPTA ◽  
ASHISH M. PITRE ◽  
SUMATI CHAVAN PANDURNAG ◽  
SALONI SALIL VANJARI

This paper assessed the impact of the mechanization of the 8 tribal paddy farmers’ groups of Goa benefited in the year 2011 through the Tribal sub-plan program of ICAR-CCARI through results of surveys conducted in 2012 and 2015. Shift to mechanization among beneficiaries was significant in power tillers (64-100%) but less in power reapers(0-91%). Also significant saving in manpower (Power tillers:33.3% to 60%, power reapers: 33.3% to 83.3%), , time (field capacity increased (power tillers : 41.7% to141%, power reapers :58.1% to 912.8%) and cost(power tillers :44.7% to 59.1%, power reapers : 57.8% to 82.9%) was reportedthrough the use of equipment as compared to desi plough or manual methods of harvesting. Some constraints like lack of access roads and training in use and maintenance of the equipment were reported by the beneficiary farmers.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shaobin Wang ◽  
Yun Tong ◽  
Yupeng Fan ◽  
Haimeng Liu ◽  
Jun Wu ◽  
...  

AbstractSince spring 2020, the human world seems to be exceptionally silent due to mobility reduction caused by the COVID-19 pandemic. To better measure the real-time decline of human mobility and changes in socio-economic activities in a timely manner, we constructed a silent index (SI) based on Google’s mobility data. We systematically investigated the relations between SI, new COVID-19 cases, government policy, and the level of economic development. Results showed a drastic impact of the COVID-19 pandemic on increasing SI. The impact of COVID-19 on human mobility varied significantly by country and place. Bi-directional dynamic relationships between SI and the new COVID-19 cases were detected, with a lagging period of one to two weeks. The travel restriction and social policies could immediately affect SI in one week; however, could not effectively sustain in the long run. SI may reflect the disturbing impact of disasters or catastrophic events on the activities related to the global or national economy. Underdeveloped countries are more affected by the COVID-19 pandemic.


2014 ◽  
Vol 15 (4) ◽  
pp. 1517-1531 ◽  
Author(s):  
Gerhard Smiatek ◽  
Harald Kunstmann ◽  
Andreas Heckl

Abstract The impact of climate change on the future water availability of the upper Jordan River (UJR) and its tributaries Dan, Snir, and Hermon located in the eastern Mediterranean is evaluated by a highly resolved distributed approach with the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) run at 18.6- and 6.2-km resolution offline coupled with the Water Flow and Balance Simulation Model (WaSiM). The MM5 was driven with NCEP reanalysis for 1971–2000 and with Hadley Centre Coupled Model, version 3 (HadCM3), GCM forcings for 1971–2099. Because only one regional–global climate model combination was applied, the results may not give the full range of possible future projections. To describe the Dan spring behavior, the hydrological model was extended by a bypass approach to allow the fast discharge components of the Snir to enter the Dan catchment. Simulation results for the period 1976–2000 reveal that the coupled system was able to reproduce the observed discharge rates in the partially karstic complex terrain to a reasonable extent with the high-resolution 6.2-km meteorological input only. The performed future climate simulations show steadily rising temperatures with 2.2 K above the 1976–2000 mean for the period 2031–60 and 3.5 K for the period 2070–99. Precipitation trends are insignificant until the middle of the century, although a decrease of approximately 12% is simulated. For the end of the century, a reduction in rainfall ranging between 10% and 35% can be expected. Discharge in the UJR is simulated to decrease by 12% until 2060 and by 26% until 2099, both related to the 1976–2000 mean. The discharge decrease is associated with a lower number of high river flow years.


Author(s):  
Carola Leone ◽  
Michela Longo

AbstractRoad transport electrification is essential for meeting the European Union's goals of decarbonization and climate change. In this context, an Ultra-Fast Charging (UFC) system is deemed necessary to facilitate the massive penetration of Electric Vehicles (EVs) on the market; particularly as medium-long distance travels are concerned. Anyway, an ultra-fast charging infrastructure represents the most critical point as regards hardware technology, grid-related issues, and financial sustainability. Thus far, this paper presents an impact analysis of a fast-charging station on the grid in terms of power consumption, obtained by the Monte Carlo simulation. Simulation results show that it is not economical convenient size the assumed ultra-fast charging station for the maximum possible power also considering its high impact on the grid. In view of the results obtained from the impact analysis, the last part of the paper focuses on finding a method to reduce the power installed for the DC/DC stage while keeping the possibility for the electric vehicle to charge at their maximum power. To achieve this goal a modular approach is proposed. Finally, two different modular architectures are presented and compared. In both the solutions, the probability of having EVs charging at limited power is less than 5%.


2021 ◽  
Vol 13 (8) ◽  
pp. 4562
Author(s):  
Inés Aquilué ◽  
Angélica Caicedo ◽  
Joan Moreno ◽  
Miquel Estrada ◽  
Laia Pagès

This paper presents a framework to support the assessment of urban design projects through Urban Living Labs (ULLs). The framework is based on the Tactical Urbanism (TU) practices and involves the use of Mobile Urban Elements (MUE) in uncertain and potentially confusing conditions (e.g., the COVID-19 context). The methodology includes the application of the Four-Phase Model (problem and ideation; development; implementation, testing and assessment; final proposal) and a quantitative and qualitative assessment. The proposed assessment criteria were developed through an evaluation according to three aspects: (1) feasibility impact; (2) social impact; and (3) spatial impact. The methodology was applied to Furnish, an urban design project based on a ULL and prototyping, which was recently developed in five European cities. The empirical results, obtained using the impact analysis, indicate that the prototypes developed in the project are transferable to other cities and generate social interaction in public spaces. The applied research showed that the Four-Phase Model may be used as a new and improved iterative design process: the LOOP Scheme. The application of this assessment methodology to ULLs may provide valuable information for the future planning of urban interventions in public spaces.


2012 ◽  
Vol 616-618 ◽  
pp. 390-395
Author(s):  
Cheng Wu Li ◽  
Tian Bao Gao ◽  
Shan Yang Wei ◽  
Teng Li

According to the gas dynamic theory, this paper deduces the approximate calculation formula on elastic energy of a tons of coal through theory analysis, and then gets the quantitative calculation method between incident overpressure and reflected overpressure of the coal and gas outburst shock wave. The calculation formula in this paper is in line with the measured values, and so its validity has been verified. The analysis result shows that the effect of the elastic energy during the process of coal and gas outburst should be considered when the depth of the coal seam is great and the coal’s modulus of elasticity is small.


2014 ◽  
Vol 29 (6) ◽  
pp. 561-568 ◽  
Author(s):  
Hiroshi Suginaka ◽  
Ken Okamoto ◽  
Yohei Hirano ◽  
Yuichi Fukumoto ◽  
Miki Morikawa ◽  
...  

AbstractIntroductionThe catastrophic Great East Japan Earthquake in 2011 created a crisis in a university-affiliated hospital by disrupting the water supply for 10 days. In response, this study was conducted to analyze water use and prioritize water consumption in each department of the hospital by applying a business impact analysis (BIA). Identifying the minimum amount of water necessary for continuing operations during a disaster was an additional goal.ProblemWater is essential for many hospital operations and disaster-ready policies must be in place for the safety and continued care of patients.MethodsA team of doctors, nurses, and office workers in the hospital devised a BIA questionnaire to examine all operations using water. The questionnaire included department name, operation name, suggested substitutes for water, and the estimated daily amount of water consumption. Operations were placed in one of three ranks (S, A, or B) depending on the impact on patients and the need for operational continuity. Recovery time objective (RTO), which is equivalent to the maximum tolerable period of disruption, was determined. Furthermore, the actual use of water and the efficiency of substitute methods, practiced during the water-disrupted periods, were verified in each operation.ResultsThere were 24 activities using water in eight departments, and the estimated water consumption in the hospital was 326 (SD = 17) m3per day: 64 (SD = 3) m3for S (20%), 167 (SD = 8) m3for A (51%), and 95 (SD = 5) m3for B operations (29%). During the disruption, the hospital had about 520 m3of available water. When the RTO was set to four days, the amount of water available would have been 130 m3per day. During the crisis, 81% of the substitute methods were used for the S and A operations.ConclusionThis is the first study to identify and prioritize hospital operations necessary for the efficient continuation of medical treatment during suspension of the water supply by applying a BIA. Understanding the priority of operations and the minimum daily water requirement for each operation is important for a hospital in the event of an unexpected adverse situation, such as a major disaster.SuginakaH,OkamotoK,HiranoY,FukumotoY,MorikawaM,OodeY,SumiY,InoueY,MatsudaS,TanakaH.Hospital disaster response using business impact analysis.Prehosp Disaster Med.2014;29(5):1-8.


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