Decreasing Defects of Center Porosity and Improving Secondary Pipe Castings for Superalloy Ingots by Dynamics Methods

2016 ◽  
Vol 849 ◽  
pp. 526-530
Author(s):  
Chao Wang ◽  
Zhen Rui Li ◽  
Yong Ji Niu ◽  
Shi Feng Shi ◽  
Ning An
Keyword(s):  
Grain Refinement ◽  
Influence Factors ◽  
Typical Application ◽  
Advantages And Disadvantages ◽  
Dynamic Methods ◽  
Application Methods ◽  
Test Result ◽  
Working Parameter ◽  
Center Porosity ◽  
Production Situation

The causes and the influence factors of the defects of center porosity and secondary pipe of the casting superalloy ingot are briefly introduced, and the study on the principle and technical characters of grain refinement technology with dynamic methods carried out. The mechanism, working parameter and the test result of the typical application methods including the technologies of vibration of ultrasonic, the vibration of mould, the stir of mould and oscillation in the riser were investigated in detail. By comparing the advantages and disadvantages of different methods and also according to the practical production situation of our company, the most appropriate one for improving the defects of center porosity and secondary pipe is proposed.

Effects of Y on the Microstructure and Mechanical Properties of Mg-Zn-Y-Zr Magnesium Alloys

2017 ◽  
Vol 904 ◽  
pp. 29-35
Author(s):  
Da Yu Wang ◽  
Zhi Ming Du ◽  
Hong Juan Zhang ◽  
Li Hua Chen ◽  
Chang Shun Wang
Keyword(s):  
Mechanical Property ◽  
Grain Refinement ◽  
Mass Fraction ◽  
Atomic Ratio ◽  
Extension Rate ◽  
Precipitated Phase ◽  
Mold Casting ◽  
Alloy Increase ◽  
Test Result ◽  
Zr Alloys

Mg-Zn-Zr-Y billets with different mass fraction of Y (wt%(Y)=0.2%、0.5%、1.0%、1.5%、2.0%) was prepared by permanent mold casting. The increase in Y content has shown grain refinement effects on the microstructure morphologies of Mg–Zn–Y–Zr alloys. When the content of Y achieves 1.0 wt%, the grain refinement effect of the Y is most obvious than any more contents of the Y content. In the test result of XRD, the type of precipitated phase in Mg-Zn-Zr-Y alloys is related to atomic ratio of Y/Zn. With content of Y increases, atomic ratio of Y/Zn increases,the precipitated phase in alloy is changed from Phase I to Phase W. Tensile strength and extension rate of alloy increase with the increasing of Y content; When Y content reaches 1.0%, mechanical property reaches maximum value.When content of Y exceeds 1.0%, with the increasing of Y content, mechanical property of alloy declines gradually.

scholarly journals Proposal for the training of flexible education in preschool and public educational stages in the Kingdom of Saudi Arabia

2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Hanan bint Ahmed bin Mishni al-Zahrani
Keyword(s):  
Saudi Arabia ◽  
Primary Education ◽  
Education System ◽  
Arab World ◽  
Traditional Education ◽  
Educational Process ◽  
Advantages And Disadvantages ◽  
Application Methods ◽  
Analytical Approaches ◽  
Flexible Education

The aim of this study is to recognize the flexible education system in primary education stages and preschools in the Arab world. Along with the justifications for acknowledging such a system، including its contributions in solving the issues of the school education system and its application methods. This study is based on both descriptive and analytical approaches to analyses the findings by identifying the justifications for acknowledging this system، together with previous studies and successful examples، and make comparison between the traditional education and the flexible education system and this study was the tool in observation and analysis the stories،pictures and videos of learning experiment for families who adopt flexible education system and apply that in two public education schools and twenty flexible education systems. This study formed from observation and analysis eight points : the objectives of the educational process، the teacher، the curriculum، student needs، teaching strategies، educational environment and its preparation،educational speed and evaluation .And determination the advantages and disadvantages to everyone from these eight points . The results of the study according to the eight points above show that the flexible education system in primary education stages and preschools is outperform the traditional education system . They also show the reasons and justifications to experiment the flexible education system and its application methods . According to the result the study confirm to apply the flexible education system in primary stages and preschools in Saudi Arabia to keep up with modern educational systems، and for its benefits to society as a whole .  

Influence Study of the Influence Domain to Numerical Simulation Results with Meshless Method

2013 ◽  
Vol 448-453 ◽  
pp. 3223-3228
Author(s):  
Ning Ding ◽  
Yan Fang Zhang ◽  
Hao Wang ◽  
Jiang Rong Xu
Keyword(s):  
Meshless Method ◽  
Interpolation Method ◽  
Weighted Least Squares ◽  
Influence Factors ◽  
Average Error ◽  
Stable Method ◽  
Weak Formulation ◽  
Advantages And Disadvantages ◽  
Node Distribution ◽  
Radial Basis

Meshless method calculation accuracy is influenced by many factors, in which influence domain and node distribution are the most important. Due to the restrictions of the meshless methods themselves, their respective influence factors are different. In the paper, the advantages and disadvantages of the collocation method, the meshless method based on the local weak formulation and collocation (MWS), the meshless radial basis interpolation method based on global weak formulation (RPIM) and the weighted least squares meshless method (MWLS) are discussed by comparing the average error of nodes value in different influence domain radius. The results show that the accuracy of the MVS method is higher, but not stable; the radial basis interpolation method based on global weak formulation (RPIM) is a relatively stable method, but needs a large amount of calculation; better results can be obtained using the collocation with a small amount of the polynomial basis function added, simple and practicable.

Corrosion Growth and Remnant Life Assessment: How to Pick the Right Approach for Your Pipeline

2016 ◽  
Author(s):  
Michael Smith ◽  
Cheryl Argent ◽  
Andrew Wilde
Keyword(s):  
Life Assessment ◽  
Inspection Planning ◽  
Scoring Method ◽  
Repair Work ◽  
Advantages And Disadvantages ◽  
Pipe Joints ◽  
Application Methods ◽  
Inspection Data ◽  
The Right

Accurate modelling of future corrosion growth is critical to long term pipeline integrity. A lot has been published within the industry regarding how to accurately determine corrosion growth rates (CGRs) from repeat in-line inspection data but there is limited guidance to support pipeline operators in deciding how to apply CGRs in order to support the development of repair plans and investigate pipeline remnant life. The consequences of significantly under- or overestimating CGRs are high and getting the balance right between the two is not straightforward. Future integrity decisions can be made using maximum, upper bound, or average corrosion rates, and these rates may be calculated for and applied to individual features, pipe joints, or segments. All of the commonly used methods have advantages and disadvantages. In this paper 10 CGR application methods have been applied to 3 onshore pipelines in which 3 inspections were conducted. The methods were compared against each other by reviewing the corrosion growth predictions from the 1st and 2nd inspections with the actual results of the 3rd inspection. The aims of the study were: i. to identify the methods that limit underestimation of corrosion growth but also do not severely overestimate corrosion growth, and ii. to identify which methods are most appropriate for the different future integrity decisions, e.g. repair & re-inspection planning and remnant life estimation. A scoring methodology was developed in order to compare and rank the CGR application methods. The methodology was based on an underestimation score (to identify which methods minimize underestimation) and an overestimation score (to identify which methods limit unnecessary repair work). The scoring method allowed for weightings to be applied to the under- and overestimation scores to take account of how the priorities vary when making different future integrity decisions.

Desirable standards for laboratory tests if they are to fulfill medical needs

1993 ◽  
Vol 39 (7) ◽  
pp. 1447-1455 ◽  
Author(s):  
C G Fraser ◽  
P H Petersen
Keyword(s):  
Laboratory Tests ◽  
Normal Values ◽  
Performance Standards ◽  
Biological Variation ◽  
Test Results ◽  
Medical Needs ◽  
Advantages And Disadvantages ◽  
Clinical Vignettes ◽  
Traditional Approaches ◽  
Test Result

Abstract Many strategies to define desirable standards for laboratory tests to fulfill medical needs have been proposed over the last three decades. Traditional approaches are based on reference (normal) values, opinions of clinicians, the state of the art, views of experts, data on biological variation, and assessment of the effect of error on clinical use. All these approaches have advantages and disadvantages, but the consensus of experts reached over a decade ago that imprecision desirably be less than one-half of the within-subject biological variation still seems to provide the best set of generally applicable performance standards. Desirable bias is less than one-quarter of the group (within-subject plus between-subject) biological variation. Recent proposals are either restatements of traditional recommendations, further empirical suggestions, or models based on assessment of clinical needs, and have not been widely accepted. Both old and new studies on clinical opinions, sought by using structured questionnaires containing clinical vignettes designed to seek views on the magnitude of significant change, are flawed in design, execution, and data analysis. Until clinicians are more aware of test-result variability and clinical chemists gain quantitative knowledge on the interpretation of test results, it will be difficult to set desirable standards that fulfill actual medical needs, except in a few well-defined screening situations.

The Analysis of Influence Factors in Cement Strength Test

2017 ◽  
Vol 726 ◽  
pp. 23-27
Author(s):  
Xiao Bo Yan ◽  
Xu Fang Wang ◽  
Chan Gan Wang
Keyword(s):  
Experimental Study ◽  
Influence Factors ◽  
Strength Test ◽  
Experimental Results ◽  
Test Accuracy ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Vibrating Table ◽  
Cement Strength ◽  
Test Result

A broad experimental study had been carried out to characterize the effects of personnel operation and apparatus on cement strength test in this paper. The experimental results illustrated that wipe method of bowl influenced cement strength test result through changing water to cement ratio. In addition, cement strength results compacted by vibrating table were lower than that compacted by jolting apparatus. Also, it found that the installation way of jolting apparatus and the conditions of clamps had a significant effect on cement strength test result. Moreover, the use of ejector would reduce specimens’ damage in the demolding process, which ensured cement strength test accuracy.

scholarly journals IDENTIFICATION OF INFLUENCE FACTORS ON THE INVESTMENTS EFFICIENCY IN AUTOMATION OF INDUSTRIAL ENTERPRISES MANAGEMENT IN THE CONTEXT OF BUSINNES CLUSTERS FORMATION

2020 ◽  
Vol 288 (6) ◽  
pp. 48-53
Author(s):  
V. LYSAK ◽  
Keyword(s):  
User Satisfaction ◽  
Business Processes ◽  
Influence Factors ◽  
Automated System ◽  
Enterprise Management ◽  
Erp System ◽  
Advantages And Disadvantages ◽  
Industrial Enterprises ◽  
Enterprise Management System ◽  
The Impact

The formation of the ERP is a complex and time-consuming process, and therefore for the successful completion of the project it is necessary to develop a strategic plan for management automation and the use of modern approaches to assess its effectiveness. An important aspect of the formation of an effective ERP is to identify, analyze and assess the impact of external and internal factors that affect the satisfaction of future users of the implemented system – staff and managers at all levels. The article analyzes common approaches to identifying factors influencing the effectiveness of projects for automation of industrial enterprise management. The application of common approaches to assessing the effectiveness of an automated enterprise management system at different levels of maturity of its IT infrastructure, indicating their main advantages and disadvantages, and gives priority to the total cost of ownership as a key. It is proved that to increase the productivity and efficiency of ERP-system enterprises should take into account the factors that affect user satisfaction. At present, it is actually possible to determine the effectiveness of IT investments for Ukrainian enterprises is the analysis of whether it is possible to achieve the set goals at the expense of funds allocated for automation, formulated not in the form of their return coefficient, but in terms characterizing the parameters of automated processes. In general, for most modern enterprises before the implementation of AMS it is necessary to conduct an audit and reorganization of their activities to create rational technologies and business processes. Reorganization in this case does not necessarily mean a change in the organizational structure of the enterprise, but the optimization of processes to achieve greater productivity at lower cost. Prospects for the development and maintenance of the system are important for domestic enterprises, which are mainly determined by the developer (supplier) of the automated system, as well as a set of standards that is embedded in the system and its components. In addition, an important role in choosing a supplier is the form of its presence in the domestic market, which is formed by the presence of a network of certified technical support centers, authorized training centers, “hotlines” for consultations and more.

scholarly journals Experimental Models of Absence Epilepsy

2020 ◽  
Vol 11 (6) ◽  
pp. 715-726
Author(s):  
Maryam Jafarian ◽  
◽  
Mohammad Esmaeil Alipour ◽  
Fariba Karimzadeh ◽  
◽  
...  
Keyword(s):  
Animal Models ◽  
Ethical Issues ◽  
Close Correlation ◽  
Absence Epilepsy ◽  
Experimental Models ◽  
Human Condition ◽  
Genetic Models ◽  
Advantages And Disadvantages ◽  
Epileptic Patients ◽  
Application Methods

Introduction: Absence epilepsy is a brief non-convulsive seizure associated with sudden abruptness in consciousness. Because of the unpredictable occurrence of absence seizures and the ethical issues of human investigation on the pathogenesis and drug assessment, researchers tend to study animal models. This paper aims to review the advantages and disadvantages of several animal models of nonconvulsive induced seizure. Methods: The articles that were published since 1990 were assessed. The publications that used genetic animals were analyzed, too. Besides, we reviewed possible application methods of each model, clinical types of seizures induced, purposed mechanism of epileptogenesis, their validity, and relevance to the absence epileptic patients. Results: The number of studies that used genetic models of absence epilepsy from years of 2000 was noticeably more than pharmacological models. Genetic animal models have a close correlation of electroencephalogram features and epileptic behaviors to the human condition. Conclusion: The validity of genetic models of absence epilepsy would motivate the researchers to focus on genetic modes in their studies. As there are some differences in the pathophysiology of absence epilepsy between animal models and humans, the development of new animal models is necessary to understand better the epileptogenic process and, or discover novel therapies for this disorder.

scholarly journals Application of Ground-based 3D Laser Scanning Technology in Engineering Surveying

2021 ◽  
Vol 236 ◽  
pp. 05033
Author(s):  
Xue Ting ◽  
Li Ting ◽  
Ni Jiahui
Keyword(s):  
Technological Process ◽  
3D Modeling ◽  
Laser Scanning ◽  
3D Laser Scanning ◽  
Topographic Map ◽  
Advantages And Disadvantages ◽  
Engineering Survey ◽  
Application Methods ◽  
Urban Engineering ◽  
Surveying And Mapping

In this paper, the technological process of fixed ground-based 3D laser scanning technology in practical production of engineering survey is introduced, and application methods of the technology in topographic map surveying and mapping, earthwork calculation, road surveying, 3D modeling and other aspects are systematically discussed. Meanwhile, the paper summarizes the advantages and disadvantages of this technology compared with traditional surveying and mapping methods, discusses the application direction and prospect of ground-based 3D laser scanning technology in the future11, and provide a reference for the application of this technology in urban engineering surveying.

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