scholarly journals Stochastic simplified modelling of abrasive waterjet footprints

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150836 ◽  
Author(s):  
P. Lozano Torrubia ◽  
J. Billingham ◽  
D. A. Axinte
Keyword(s):  
Differential Equation ◽  
Stochastic Partial Differential Equation ◽  
Abrasive Waterjet ◽  
Random Component ◽  
Erosion Process ◽  
Complex Shapes ◽  
Main Components ◽  
Etched Surface ◽  
Conventional Machining

Abrasive micro-waterjet processing is a non-conventional machining method that can be used to manufacture complex shapes in difficult-to-cut materials. Predicting the effect of the jet on the surface for a given set of machine parameters is a key element of controlling the process. However, the noise of the process is significant, making it difficult to design reliable jet-path strategies that produce good quality parts via controlled-depth milling. The process is highly unstable and has a strong random component that can affect the quality of the workpiece, especially in the case of controlled-depth milling. This study describes a method to predict the variability of the jet footprint for different jet feed speeds. A stochastic partial differential equation is used to describe the etched surface as the jet is moved over it, assuming that the erosion process can be divided into two main components: a deterministic part that corresponds to the average erosion of the jet and a stochastic part that accounts for the noise generated at different stages of the process. The model predicts the variability of the trench profiles to within less than 8%. These advances could enable abrasive micro-waterjet technology to be a suitable technology for controlled-depth milling.

The Influence of the Technical Parameters on the Quality of Engineering Ceramics by Abrasive Waterjet

2013 ◽  
Vol 416-417 ◽  
pp. 1689-1692
Author(s):  
Feng Lian Zhang ◽  
Jing Zhu
Keyword(s):  
High Temperature ◽  
High Hardness ◽  
Abrasive Waterjet ◽  
Engineering Ceramics ◽  
Wear Resistant ◽  
Technical Parameters ◽  
Machining Quality ◽  
Conventional Machining

Engineering Ceramics is a inorganic nonmetal material, which is sintered at high-temperature. ceramics have promising potential as high-temperature strength.erosion-resistant, wear-resistant and hot impact-resistant.However, because they have high hardness and brittleness as well as nonconductive, it is very difficult to machine them using conventional machining. Their use-area is restricted. At presently, the machining technology of Engineering Ceramics by abrasive waterjet become more and more important for humankind. In this paper, the influence of technical parameters on machining quality has been studied and analyzed. A better changing method of technical parameters is given.

Methodical approach to the assessment of the educational migration environment of the population of the Carpathian region

2019 ◽  
pp. 37-48
Author(s):  
Lyubov Semiv
Keyword(s):  
Institutional Conditions ◽  
Carpathian Region ◽  
Research Activities ◽  
Methodical Approach ◽  
Synthetic Indicator ◽  
Industry Collaboration ◽  
Migration Potential ◽  
Educational Migration ◽  
Main Components

The role and importance of the educational migration environment in activating migration movements of the population is described. The main components of the educational migration environment of the population are identified, and their features are outlined. Indicators have been proposed and the conditions for the formation of the educational migration environment of the population have been determined. It is proved that «freedom of knowledge movement» motivates students, teachers and researchers to combine educational and research activities with future employment abroad. The processes of educational migration in the form of cross-border education and academic mobility are presented. The concept of educational migration environment is defined and five main components of its formation are described: quantitative measurement of educational migration potential; quality of the academic environment; motivational conditions; opportunities for universities and industry collaboration in research; institutional conditions in the educational sphere. The list of indicators offered by the Ukrainian statistics is provided for quantitative representation of each component of the educational migration. Based on the method of multidimensional (cluster) analysis, the regional index of formation of educational migration environment is calculated. Using this method allows to move from the assessment of educational migration environment on 28 indicators to the construction of one synthetic indicator. Application of methodical approach allows to see the place of the region by the important parameters of development of the environment of educational migration of the population, to evaluate the attractiveness, opportunities and threats of formation of this environment in the regional dimension. It is proved that the «most favorable» environment in the Carpathian region has the Lviv region (4th place in Ukraine). Other regions of the Ukrainian Carpathians occupy in the ranking the lower places: respectively Ivano-Frankivsk (15th place), Chernivtsi (21st place), Transcarpathian region (24th place).

New Monitoring Strategy for the Quality Control in the Processing Practice of Scutellariae Radix

2020 ◽  
Vol 16 (3) ◽  
pp. 303-311
Author(s):  
Qi Huang ◽  
Chunsong Cheng ◽  
Lili Li ◽  
Daiyin Peng ◽  
Cun Zhang
Keyword(s):  
Quality Control ◽  
Monitoring Strategy ◽  
Scutellariae Radix ◽  
Chromatographic Fingerprints ◽  
New Strategy ◽  
Processed Products ◽  
Main Components ◽  
Processing Techniques ◽  
Multivariate Monitoring

Background: Scutellariae Radix (Huangqin) is commonly processed into 3 products for different clinical applications. However, a simple analytical method for quality control has rarely been reported to quickly estimate the degree of processing Huangqin or distinguish differently processed products or unqualified Huangqin products. Objective: To study a new strategy for quality control in the processing practice of Huangqin. Methods: Seven kinds of flavonoids that mainly exist in Huangqin were determined by HPLC-DAD. Chromatographic fingerprints were established to study the variation and discipline of the 3 processed products of Huangqin. PCA and OPLS-DA were used to classify differently processed products of Huangqin. Results: The results showed that baicalin and wogonoside were the main components in the crude and the alcohol Huangqin herb while baicalein and wogonin mainly existed in carbonized Huangqin. The results of mathematical statistics revealed that the processing techniques can make the quality of medicinal materials more uniform. Conclusion: This multivariate monitoring strategy is suitable for quality control in the processing of Huangqin.

scholarly journals Determination of Environmental Factors for the Implementation of the Exploitability Index in Industrial Aggregate Mining Using Multi-Criteria Analysis

2021 ◽  
Vol 10 (4) ◽  
pp. 196
Author(s):  
Julio Manuel de Luis-Ruiz ◽  
Benito Ramiro Salas-Menocal ◽  
Gema Fernández-Maroto ◽  
Rubén Pérez-Álvarez ◽  
Raúl Pereda-García
Keyword(s):  
Environmental Factors ◽  
Environmental Factor ◽  
Human Life ◽  
Accurate Estimation ◽  
Analytic Hierarchy ◽  
Main Components ◽  
Hierarchy Process ◽  
Made In

The quality of human life is linked to the exploitation of mining resources. The Exploitability Index (EI) assesses the actual possibilities to enable a mine according to several factors. The environment is one of the most constraining ones, but its analysis is made in a shallow way. This research is focused on its determination, according to a new preliminary methodology that sets the main components of the environmental impact related to the development of an exploitation of industrial minerals and its weighting according to the Analytic Hierarchy Process (AHP). It is applied to the case of the ophitic outcrops in Cantabria (Spain). Twelve components are proposed and weighted with the AHP and an algorithm that allows for assigning a normalized value for the environmental factor to each deposit. Geographic Information Systems (GISs) are applied, allowing us to map a large number of components of the environmental factors. This provides a much more accurate estimation of the environmental factor, with respect to reality, and improves the traditional methodology in a substantial way. It can be established as a methodology for mining spaces planning, but it is suitable for other contexts, and it raises developing the environmental analysis before selecting the outcrop to be exploited.

scholarly journals Analysis of ergonomic and unergonomic human lifting behaviors by using Inertial Measurement Units

2017 ◽  
Vol 3 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Jan Kuschan ◽  
Henning Schmidt ◽  
Jörg Krüger
Keyword(s):  
Quality Of Life ◽  
Machine Learning ◽  
Angular Velocity ◽  
Musculoskeletal System ◽  
Occupational Diseases ◽  
Inertial Measurement Units ◽  
Inertial Measurement ◽  
Measurement Units ◽  
Main Components

Abstract:This paper presents an analysis of two distinct human lifting movements regarding acceleration and angular velocity. For the first movement, the ergonomic one, the test persons produced the lifting power by squatting down, bending at the hips and knees only. Whereas performing the unergonomic one they bent forward lifting the box mainly with their backs. The measurements were taken by using a vest equipped with five Inertial Measurement Units (IMU) with 9 Dimensions of Freedom (DOF) each. In the following the IMU data captured for these two movements will be evaluated using statistics and visualized. It will also be discussed with respect to their suitability as features for further machine learning classifications. The reason for observing these movements is that occupational diseases of the musculoskeletal system lead to a reduction of the workers’ quality of life and extra costs for companies. Therefore, a vest, called CareJack, was designed to give the worker a real-time feedback about his ergonomic state while working. The CareJack is an approach to reduce the risk of spinal and back diseases. This paper will also present the idea behind it as well as its main components.

Research on the Optimal Design Method of the Main Components for the Wheelchair Pickup

2013 ◽  
Vol 791-793 ◽  
pp. 799-802
Author(s):  
Ya Ping Wang ◽  
H.R. Shi ◽  
L. Gao ◽  
Z. Wang ◽  
X.Y. Jia ◽  
...  
Keyword(s):  
Parametric Design ◽  
Design Method ◽  
Basic Function ◽  
Design Parameters ◽  
Algorithm Optimization ◽  
Optimization Analysis ◽  
Research Designs ◽  
Optimal Design Method ◽  
Main Components

With the increasing of the aging of population all over the world, and With the inconvenience coming from diseases and damage, there will be more and more people using the wheelchair as a tool for transport. When it cant be short of the wheelchair in the daily life, the addition of the function will bring the elevation of the quality of life for the unfortunate. Staring with this purpose, the research designs a pickup with planetary bevel gear for the wheelchair. After determining the basic function of the wheelchair aids, the study determines the design parameters by using the knowledge of parametric design and completes the model for the system with Pro/E, on the other hand, it completes key components optimization analysis which is based on genetic algorithm optimization.

Modal Analysis and Optimization of Spindle Box of Turn-Milling Center Based on Finite Element Method

2012 ◽  
Vol 226-228 ◽  
pp. 281-284
Author(s):  
Li Da Zhu ◽  
Xiao Bang Wang ◽  
Tiao Biao Yu ◽  
Wan Shan Wang
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
Ansys Software ◽  
Design Requirement ◽  
Design Quality ◽  
Machining Center ◽  
Main Components ◽  
Turn Milling

The dynamic characteristics of machine tool may directly affect its machining capability, which is analyzed to improve the machining precision and efficiency. In this paper, the 3D finite element model of main components turn-milling center is established by using ANSYS software, and then spindle box of turn-milling center is analyzed and optimized; the natural frequencies and vibration models are obtained after analysis, which guarantee the design requirement of the machining center. Therefore it is significant to improve the design quality of machining center by using FEA software in the design process.

Application of New Abrasives and their Quality Parameters

2017 ◽  
Vol 261 ◽  
pp. 181-188 ◽  
Author(s):  
Frantisek Holešovsky ◽  
Martin Bartos ◽  
Milan Dian ◽  
Jan Řehoř
Keyword(s):  
Quality Parameters ◽  
Abrasive Grains ◽  
Individual Grains ◽  
Conventional Machining

Recent years have highly been productive in terms of development of both conventional machining technology, but in workpiece surfaces finishing, as well. The overall trend is heading towards increasing accuracy and quality of the manufactured components for machinery and equipment. In a range of finishing abrasive technologies there has been known the introduction of microcrystalline corundum, modification of tools with these abrasive grains, including sintered tools. This development continues and the latest trend is the development of pyramidal grain the Cubitron II. How individual grains behave during operation and how we can use their properties in comparison to classic white corundum still remains complicated matter. The behaviour of selected abrasives has been described in the submitted article.

Study on the effective discharge energy mechanism of vertical ultrasonic vibration assisted EDM processing

2021 ◽  
pp. 095440542110285
Author(s):  
Yinghuai Dong ◽  
Guangyan Li ◽  
Yan Wang ◽  
Jianbao Song ◽  
Shuo Yang ◽  
...  
Keyword(s):  
Ultrasonic Vibration ◽  
Theoretical Research ◽  
Discharge Energy ◽  
Movement Path ◽  
Energy Mechanism ◽  
Effective Discharge ◽  
Parameter Matching ◽  
Discharge Gap ◽  
Conventional Machining

Compared to traditional EDM processing, UEDM (Ultrasonic Vibration Assisted EDM) have a great improvement in optimizing discharge environment. In this study, ultrasonic vibration is attached to the electrode. According to the relative positional relationship between the movement path of the electrode tip and the discharge gap, four working states of UEDM are defined. The four working states are the path within the discharge gap, the path in contact with the edge of the discharge gap, part of the electrode end path outside the discharge gap, and the path in contact with the workpiece, respectively. States are analyzed from the effective discharge energy and discharge frequency. A mathematical model for effective discharge energy and surface roughness is established for two conventional working states. The correctness of the theoretical research is verified by experiments. As the experiment results shown, the influence of ultrasonic amplitude on the energy of UEDM is primary, while frequency is secondary. A working state with better discharge stability and higher discharge energy when the electrode end path is in contact with the edge of the discharge gap. In the first three conventional machining states, the surface quality of the workpiece increases with the increase of ultrasonic amplitude and frequency. The study can provide scientific guidance for parameter matching of UEDM.

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