scholarly journals PRACTICAL REALIZATION OF METHODOLOGY OF PROCESS CONTROL OF TOOLING

Author(s):  
Natalia Veselovska

The problem of providing of necessary quality and exploitation of properties of details of machines acquires an all more important value in an engineer. However to present tense the not worked out is generalized theoretical dependences between the parameters of quality of surface, exactness of treatment, operating properties of details and parameters of processes of tooling, that allow to decide the task of the technological providing of the set operating properties of details. Process control of forming of surface with necessary properties comes true mainly by the use of partial experimental dependences and tables of the modes of treatment. Complication of problem consists in that at treatment of details it is necessary to set such terms of treatment, that would provide the complex of requirements in relation to the wear of instrument, exactness of treatment, to descriptions of quality of surface, productivity and others like that. The areas of the most effective use of the productive systems are foremost determined by a technological equipment that is component part by the nomenclature of workparts and CAS of management. Experience of development and exploitation of mechanisms of parallel kinematics confirms them high efficiency and perspective of this direction of engineer. As a result of structural features of arrangement, the mechanisms of parallel kinematics have the reserved kinematics chains that form spatial structures. As a rule these structures are founded on the base of the three-cornered cored systems. They have high rigid descriptions, provide high-rate and accelerations of working organs. Accordingly given an opportunities it is allowed by substantial character to promote static and dynamic exactness of positioning of mechanisms. Wide introduction of mechanisms of parallel kinematics absence of theoretical bases of development of mechanisms interferes with, in particular mechanisms of an increase exactness. The increase of exactness needs complex research of kinematics and working processes that take place in their basic knots. Therefore researches are sent to the increase of parameters of static and dynamic exactness of spatial mechanisms of parallel kinematics is actual.

InfoMat ◽  
2021 ◽  
Author(s):  
Ganyu Zheng ◽  
Qiaowei Lin ◽  
Jiabin Ma ◽  
Jun Zhang ◽  
Yan‐Bing He ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 962
Author(s):  
Andrzej Marczuk ◽  
Vasily Sysuev ◽  
Alexey Aleshkin ◽  
Petr Savinykh ◽  
Nikolay Turubanov ◽  
...  

Mixing is one of the most commonly used processes in food, animal feed, chemical, cosmetic, etc., industries. It is supposed to provide high-quality homogenous, nutritious mixtures. To provide appropriate mixing of materials while maintaining the process high efficiency and low energy consumption it is crucial to explore and describe the material flow caused by the movement of mixing elements and the contact between particles. The process of mixing is also affected by structural features of the machine components and the mixing chamber, speed of mixing, and properties of the mixed materials, such as the size of particles, moisture, friction coefficients. Thus, modeling of the phenomena that accompany the process of mixing using the above-listed parameters is indispensable for appropriate implementation of the process. The paper provides theoretical power calculations that take into account the material speed change, the impact of the material friction coefficient on the screw steel surface and the impact of the friction coefficient on the material, taking into account the loading height of the mixing chamber and the chamber loading value. Dependencies between the mixer power and the product degree of fineness, rotational speed of screw friction coefficients, the number of windings per length unit, and width of the screw tape have been presented on the basis of a developed model. It has been found that power increases along with an increase in the value of these parameters. Verification of the theoretical model indicated consistence of the predicted power demand with the power demand determined in tests performed on a real object for values of the assumed, effective loading, which was 65–75%.


Author(s):  
Roberto Barcala-Furelos ◽  
Cristian Abelairas-Gómez ◽  
Alejandra Alonso-Calvete ◽  
Francisco Cano-Noguera ◽  
Aida Carballo-Fazanes ◽  
...  

Abstract Introduction: On-boat resuscitation can be applied by lifeguards in an inflatable rescue boat (IRB). Due to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2) and recommendations for the use of personal protective equipment (PPE), prehospital care procedures need to be re-evaluated. The objective of this study was to determine how the use of PPE influences the amount of preparation time needed before beginning actual resuscitation and the quality of cardiopulmonary resuscitation (CPR; QCPR) on an IRB. Methods: Three CPR tests were performed by 14 lifeguards, in teams of two, wearing different PPE: (1) Basic PPE (B-PPE): gloves, a mask, and protective glasses; (2) Full PPE (F-PPE): B-PPE + a waterproof apron; and (3) Basic PPE + plastic blanket (B+PPE). On-boat resuscitation using a bag-valve-mask (BVM) and high efficiency particulate air (HEPA) filter was performed sailing at 20km/hour. Results: Using B-PPE takes less time and is significantly faster than F-PPE (B-PPE 17 [SD = 2] seconds versus F-PPE 69 [SD = 17] seconds; P = .001), and the use of B+PPE is slightly higher (B-PPE 17 [SD = 2] seconds versus B+PPE 34 [SD = 6] seconds; P = .002). The QCPR remained similar in all three scenarios (P >.05), reaching values over 79%. Conclusion: The use of PPE during on-board resuscitation is feasible and does not interfere with quality when performed by trained lifeguards. The use of a plastic blanket could be a quick and easy alternative to offer extra protection to lifeguards during CPR on an IRB.


2018 ◽  
Vol 251 ◽  
pp. 03052 ◽  
Author(s):  
Andrey Benuzh ◽  
Sergey Fedorov ◽  
Ekaterina Orenburova

The article presents special characteristics of mathematical modeling of the process control a resource efficient heat supply system of industrial buildings and facilities, where constant temperature maintenance is especially critical for the process. A functional diagram of the operation of the continuous heat supply process is provided. The dependence of temperature at the point of heat-transfer fluid mixing on environmental is analyzed and control system operation algorithm is proposed.


2008 ◽  
Vol 2008 ◽  
pp. 1-4
Author(s):  
Luca Barletta ◽  
Arnaldo Spalvieri

This work focuses on high-rate () moderate-length () low-density parity-check codes. High-rate codes allow to maintain good quality of the preliminary decisions that are used in carrier recovery, while a moderate code length allows to keep the latency low. The interleaver of the LDPC matrix that we consider is inspired to the DVB-S2 standard one. A novel approach for avoiding short cycles is analyzed. A modified BP decoding algorithm is applied in order to deal with longer cycles. Simulations and results for the AWGN channel are presented, both for BPSK signalling and for coded modulation based on the partition .


2013 ◽  
Vol 842 ◽  
pp. 634-638
Author(s):  
Yan Jing ◽  
Feng Zhao

By comparison, this paper determines inner bore processing technic program of the engineering machinery hydraulic cylinder block and makes some analysis of the rolling processing technic and relevant emerging issues to propose reasonable and feasible process route and process parameters and ensure the quality of the cylinder processing. It also shows the design of boring-rolling compound tools with high efficiency and high precision for given cylinders.


2014 ◽  
Vol 989-994 ◽  
pp. 1631-1634
Author(s):  
Ping Wang ◽  
Bin Wang

Product data is the source data of product lifecycle in manufacturing enterprise. The quality of product data largely determines the effect of the application of Engineering analysis, simulation assembly and CNC programming work and so on. In order to solve the problems of the existing product data quality, such as validation custom trival, lack of high efficiency and flexibility, etc. The validation method of product data quality (PDQ) based on class was proposed in NX software environment, the representation of validation rules classes of product data quality, validation rules customization and implementation of validation process were introduced in detail in this study. Finally, an application case was employed to verify the practicability and effectiveness of the proposed method.


2014 ◽  
Vol 08 (02) ◽  
pp. 229-243
Author(s):  
Sachin Deshpande

The newly approved High Efficiency Video Coding Standard (HEVC) includes temporal sub-layering feature, which provides temporal scalability. Two types of pictures — Temporal Sub-layer Access Pictures and Step-wise Temporal Sub-layer Access Pictures are provided for this purpose. This paper utilizes the temporal scalability in HEVC to provide bandwidth adaptive HTTP streaming. We describe our HTTP streaming algorithm, which is media timeline aware and which dynamically switches temporal sub-layers on the server side. We performed subjective tests to determine user perception regarding acceptable frame rates when using temporal scalability of HEVC. These results are used to control the algorithm's temporal switching behavior to provide a good quality of experience to the user. We applied Internet and 3GPP error-delay patterns to validate the performance of our algorithm.


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