Experiment Study on Disrepair Principle for the Waved-Edge Milling Insert with Complex 3D Grooves

2011 ◽  
Vol 311-313 ◽  
pp. 722-725
Author(s):  
Yao Nan Cheng ◽  
Zhen Jia Li ◽  
Yi Zhi Liu ◽  
Hui Ping Zhang ◽  
Xian Zhou Wang
Keyword(s):  
Distribution Function ◽  
Processing System ◽  
Rake Face ◽  
Experiment Study ◽  
Statistic Method ◽  
Contrast Analysis ◽  
Automated Processing ◽  
Milling Temperature ◽  
The Difference ◽  
The Impact

The impact disrepair and adhering disrepair of milling insert are the important factors that affect the normally running of the automated processing system. Based on machining the 45 steel, find out the difference of the impact disrepair invalidation types between the waved-edge milling insert and flat rake milling insert, build the impact disrepair life cumulating distribution function mathematic models by the mathematics statistic method and have contrast analysis of the impact disrepair average lives between them. Based on the experiments on milling the 3Cr-1Mo-1/4Vsteel, find out the difference of the adhering disrepair invalidation types between them, build the quantitative mathematic relation between milling temperature and maximal adhering disrepair depth on rake face, and analyze the rule that the milling temperature affects the adhering disrepair. All these studies provide the theoretic and experimental bases for the groove optimization.

Experiment Study on Cutter Disrepair Principle and Optimization for Machining Heat-Resistant Steel

2012 ◽  
Vol 500 ◽  
pp. 58-64
Author(s):  
Yao Nan Cheng ◽  
Xian Li Liu ◽  
Fu Gang Yan ◽  
Zhen Jia Li ◽  
Xian Zhou Wang
Keyword(s):  
Mathematic Model ◽  
Resistant Steel ◽  
Experiment Study ◽  
Premature Failure ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Design Production ◽  
Milling Temperature ◽  
The Difference ◽  
The Impact

In order to find out the cutter disrepair principle and provide a valuable reference for the design, production and use of the heavy-duty hard alloy cutter, have experiment study on machining the heat-resistant steel-the 3Cr-1Mo-1/4Vsteel. First, have impact disrepair experiments with several types of different grooves milling inserts, and find out the difference of the impact disrepair invalidation types among them, and build the impact disrepair life cumulating distribution function mathematic model. Second, based on the adhering disrepair experiments, find out the difference of the adhering disrepair invalidation types, build the quantitative mathematic relation between milling temperature and maximal adhering disrepair depth on rake face of the cutter, and analyze the rule that the milling temperature affects the adhering disrepair. And then, on the basis of the scene machining, have analysis on cutter disrepair phenomenon and mechanism under the joint action of force and heat, so to provide a theoretical basis on how to avoid premature failure of the tool for the actual production process.

Bootstrap-current computations for a stellarator-reactor plasma

1990 ◽  
Vol 44 (3) ◽  
pp. 431-453 ◽  
Author(s):  
W. D. D'Haeseleer ◽  
W. N. G. Hitchon ◽  
C. D. Beidler ◽  
J. L. Shohet
Keyword(s):  
Distribution Function ◽  
Kinetic Equation ◽  
Physical Interpretation ◽  
Collision Operator ◽  
Numerical Code ◽  
Parallel Flows ◽  
Bootstrap Current ◽  
The Difference ◽  
Rotational Transform ◽  
The Impact

Numerical results for the bootstrap current in a stellarator-reactor plasma are presented. The distribution function f is computed numerically from a kinetic equation that is averaged over the helical ripple. The parallel flows and the current are obtained as v‖ moments of f. The physics issues embedded in the code are discussed concisely, concentrating on the justification as to why the bootstrap current can be estimated from an averaged scheme. Results are presented for typical stellarator-reactor parameters. The numerical code FLOCS predicts that the momentum-restoring terms in the collision operator have no significant impact on the value of the bootstrap current (the difference being about 10%). The results obtained are related to the equilibrium flows, and a physical interpretation based on the kinetic picture is presented. Finally, an estimate for the impact of J‖ on the rotational transform is given.

Shielding Calculation Research Based on Point-Kernel Integral Method

2013 ◽  
Author(s):  
Yuhao Yin ◽  
Sizhong Ding ◽  
Yichao Huang
Keyword(s):  
Integral Method ◽  
Processing System ◽  
Dose Calculation ◽  
Radiation Shielding ◽  
Buildup Factor ◽  
Gaseous Waste ◽  
Calculation Results ◽  
The Difference ◽  
Input Form ◽  
The Impact

Point-kernel integral method, which has been verified by authorities, is widely used in radiation shielding calculations. In this article, we introduced point-kernel integral method in detail. Calculations have been performed for the radiation shielding design of TEG (gaseous waste processing system) system of one Chinese CRP1000 reactor, using the point-kernel integral codes QAD-CGA and Microshield 9. Dose results calculated by the two representative codes are compared from several aspects. We also focus our discussion on the impact of buildup factors that are fitted by different kinds of methods, which are the most important parameters in point-kernel integral method. From the discussion in this article, we can draw the conclusions that 1)both of the two codes are of accurate and consistent calculation results, shielding calculation results are convinced; Microshield 9 proved to be reasonably reliable compared to results of traditional code QAD-CGA; 2) compared with QAD-CGA, Microshield 9 uses the latest database and simpler input form, but cannot calculate more than one source at one time; 3) buildup factor plays the most important role in point-kernel integral method; the two codes adopt different kinds of buildup factor fitting method; for the difference of dose calculation results using buildup factor or not, QAD-CGA is a little higher than Microshield 9 because of the different buildup factor calculation principles; 4) besides, the buildup factor reference material is advised to use either the last or the most dominant shielding.

Study on Impact Disrepair Mathematic Model and Groove Optimization of Cutting Tools for Machining Carbon Structural Steel

2008 ◽  
Vol 375-376 ◽  
pp. 459-464
Author(s):  
Yao Nan Cheng ◽  
Zhen Jia Li ◽  
Yong Gang Zhao ◽  
Wei Jun Sun
Keyword(s):  
Cutting Tools ◽  
Mathematic Model ◽  
Force Density ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Systemic Impact ◽  
Contrast Analysis ◽  
Carbon Structural Steel ◽  
The Difference ◽  
The Impact

Based on the theoretic analysis and experiments on milling the carbon structural 45 steel with the flat rake milling insert and the waved-edge milling insert with complex 3D grooves which is developed by HarBin University of Science and Technology, we have studied on the impact disrepair mathematic model and groove optimization. On the basis of the milling force mathematic model and force density function of the waved-edge milling insert with complex 3D grooves the author built, we have the finite element analysis and blurry synthetical judgement of the 3D stress field, and forecast that the anti-impact disrepair capability of the waved-edge milling insert is choiceness. We find out the difference of the impact disrepair invalidation types between different grooves milling inserts by the experiments. Based on the plentiful and systemic impact disrepair experiments, as the emphasis in this paper, we build the impact disrepair life cumulating distribution function mathematic model by the mathematics statistic method and have contrast analysis of the impact disrepair average lives between the two types of milling inserts, and prove that the anti-impact disrepair capability of the waved-edge milling insert is choiceness. All these studies provide the theoretic and experimental basis for solving the cutter disrepair which is the key problem in the automatization production and groove optimization.

Experiment Study on Impact Disrepair of Different Groove Milling Inserts for Machining High-Strength Steel

2011 ◽  
Vol 175 ◽  
pp. 300-304 ◽  
Author(s):  
Yao Nan Cheng ◽  
Xian Li Liu ◽  
Fu Gang Yan ◽  
Yu Fu Li ◽  
Zhen Jia Li
Keyword(s):  
High Strength Steel ◽  
Design Method ◽  
High Strength ◽  
Mathematic Model ◽  
Chemical Equipment ◽  
Orthogonal Experimental Design ◽  
Experiment Study ◽  
Contrast Analysis ◽  
Hydrogenation Reactor ◽  
The Impact

Based on the experiments on milling the 3Cr-1Mo-1/4Vsteel which is the main part of the large chemical equipment hydrogenation reactor with several types of different grooves milling inserts, we have experiment study on the impact disrepair. Using the Orthogonal experimental design method, we have cutting experiments on machining the high-strength steel with several types of different grooves milling inserts, and find out the difference of the impact disrepair invalidation types among them. Based on the plentiful and systemic impact disrepair experiments, we build the impact disrepair life cumulating distribution function mathematic model by the mathematics statistic method. We have contrast analysis of the impact disrepair average lives among these types of milling inserts, and the different grooves milling inserts are optimized. All these studies provide the theoretic and experimental bases for solving the cutter disrepair which is the key problem in the actual production and groove optimization.

Evaluation of the impact of public investment programs on social and economic performance of territories

2019 ◽  
pp. 109-123
Author(s):  
I. E. Limonov ◽  
M. V. Nesena
Keyword(s):  
Bayesian Modeling ◽  
Positive Impact ◽  
Public Investment ◽  
Difference In Differences ◽  
The Public ◽  
Export Activity ◽  
Regional Investment ◽  
The Difference ◽  
The Impact ◽  
Development Institution

The purpose of this study is to evaluate the impact of public investment programs on the socio-economic development of territories. As a case, the federal target programs for the development of regions and investment programs of the financial development institution — Vnesheconombank, designed to solve the problems of regional development are considered. The impact of the public interventions were evaluated by the “difference in differences” method using Bayesian modeling. The results of the evaluation suggest the positive impact of federal target programs on the total factor productivity of regions and on innovation; and that regional investment programs of Vnesheconombank are improving the export activity. All of the investments considered are likely to have contributed to the reduction of unemployment, but their implementation has been accompanied by an increase in social inequality.

The Use of Multimedia and its Impact on Bangladeshi EFL Learners at Tertiary Level

2020 ◽  
Vol 4 (2) ◽  
pp. 150
Author(s):  
Farzana Sharmin Pamela Islam
Keyword(s):  
Language Learning ◽  
Academic Writing ◽  
Teaching And Learning ◽  
English Language ◽  
Capital City ◽  
Tertiary Level ◽  
Language Classroom ◽  
The Difference ◽  
The Government ◽  
The Impact

As 21st century is the era of modern technologies with different aspects, it offers us to make the best use of them. After tape recorder and overhead projector (OHP), multimedia has become an important part of language classroom facilities for its unique and effective application in delivering and learning lesson. Although in many parts of Bangladesh, a South Asian developing country, where English enjoys the status of a foreign language, the use of multimedia in teaching and learning is viewed as a matter of luxury. However, nowadays the usefulness and the necessity of it are well recognized by the academics as well as the government. The study aims to focus on the difference between a traditional classroom void of multimedia and multimedia equipped classrooms at university level by explaining how multimedia support the students with enhanced opportunity to interact with diverse texts that give them more in-depth comprehension of the subject. It also focuses on audio-visual advantage of multimedia on the students’ English language learning. The study has followed a qualitative method to get an in-depth understanding of the impact of using multimedia in an English language classroom at tertiary level. For this purpose, the data have been collected from two different sources. Firstly, from students’ written response to  an open ended question as to their comparative experience of learning  lessons with and without multimedia facilities; and secondly, through  observation of English language classes at a private university of Dhaka, the capital city of Bangladesh. The discussion of the study is limited to  the use of multimedia in English language classroom using cartoons, images and music with a view to enhance students’ skills in academic writing, critical analysis of image and critical appreciation of music. For this purpose, cartoons in English language, images from Google and music from You Tube have got focused discussion in this paper.

Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Residential Areas ◽  
Railway Systems ◽  
Railway Noise ◽  
Sound Levels ◽  
Noise Barrier ◽  
The Difference ◽  
Reduction Effect ◽  
The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

scholarly journals Soil Moisture Dynamics in Response to Precipitation and Thinning in a Semi-Dry Forest in Northern Mexico

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 105
Author(s):  
Argelia E. Rascón-Ramos ◽  
Martín Martínez-Salvador ◽  
Gabriel Sosa-Pérez ◽  
Federico Villarreal-Guerrero ◽  
Alfredo Pinedo-Alvarez ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Forest Management ◽  
Water Availability ◽  
Dry Forest ◽  
Rainfall Events ◽  
Rainfall Characteristics ◽  
Northern Mexico ◽  
The Difference ◽  
The Impact ◽  
Moisture Dynamics

Understanding soil moisture behavior in semi-dry forests is essential for evaluating the impact of forest management on water availability. The objective of the study was to analyze soil moisture based in storm observations in three micro-catchments (0.19, 0.20, and 0.27 ha) with similar tree densities, and subject to different thinning intensities in a semi-dry forest in Chihuahua, Mexico. Vegetation, soil characteristics, precipitation, and volumetric water content were measured before thinning (2018), and after 0%, 40%, and 80% thinning for each micro-catchment (2019). Soil moisture was low and relatively similar among the three micro-catchments in 2018 (mean = 8.5%), and only large rainfall events (>30 mm) increased soil moisture significantly (29–52%). After thinning, soil moisture was higher and significantly different among the micro-catchments only during small rainfall events (<10 mm), while a difference was not noted during large events. The difference before–after during small rainfall events was not significant for the control (0% thinning); whereas 40% and 80% thinning increased soil moisture significantly by 40% and 53%, respectively. Knowledge of the response of soil moisture as a result of thinning and rainfall characteristics has important implications, especially for evaluating the impact of forest management on water availability.

scholarly journals 216. Are Automatic Antimicrobial Stop Orders an Effective Stewardship Tool for Urinary Tract and Intra-Abdominal Infections?

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S110-S110
Author(s):  
Christina Maguire ◽  
Dusten T Rose ◽  
Theresa Jaso
Keyword(s):  
Urinary Tract ◽  
Antimicrobial Therapy ◽  
Source Control ◽  
Clostridioides Difficile ◽  
Days Of Therapy ◽  
Before And After ◽  
The Difference ◽  
Tract Infections ◽  
Length Of Therapy ◽  
The Impact

Abstract Background Automatic antimicrobial stop orders (ASOs) are a stewardship initiative used to decrease days of therapy, prevent resistance, and reduce drug costs. Limited evidence outside of the perioperative setting exists on the effects of ASOs on broad spectrum antimicrobial use, discharge prescription duration, and effects of missed doses. This study aims to evaluate the impact of an ASO policy across a health system of adult academic and community hospitals for treatment of intra-abdominal (IAI) and urinary tract infections (UTI). ASO Outcome Definitions ASO Outcomes Methods This multicenter retrospective cohort study compared patients with IAI and UTI treated before and after implementation of an ASO. Patients over the age of 18 with a diagnosis of UTI or IAI and 48 hours of intravenous (IV) antimicrobial administration were included. Patients unable to achieve IAI source control within 48 hours or those with a concomitant infection were excluded. The primary outcome was the difference in sum length of antimicrobial therapy (LOT). Secondary endpoints include length and days of antimicrobial therapy (DOT) at multiple timepoints, all cause in hospital mortality and readmission, and adverse events such as rates of Clostridioides difficile infection. Outcomes were also evaluated by type of infection, hospital site, and presence of infectious diseases (ID) pharmacist on site. Results This study included 119 patients in the pre-ASO group and 121 patients in the post-ASO group. ASO shortened sum length of therapy (LOT) (12 days vs 11 days respectively; p=0.0364) and sum DOT (15 days vs 12 days respectively; p=0.022). This finding appears to be driven by a decrease in outpatient LOT (p=0.0017) and outpatient DOT (p=0.0034). Conversely, ASO extended empiric IV LOT (p=0.005). All other secondary outcomes were not significant. Ten patients missed doses of antimicrobials due to ASO. Subgroup analyses suggested that one hospital may have influenced outcomes and reduction in LOT was observed primarily in sites without an ID pharmacist on site (p=0.018). Conclusion While implementation of ASO decreases sum length of inpatient and outpatient therapy, it may not influence inpatient length of therapy alone. Moreover, ASOs prolong use of empiric intravenous therapy. Hospitals without an ID pharmacist may benefit most from ASO protocols. Disclosures All Authors: No reported disclosures

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