scholarly journals Automated system for design and calculation of heating devices for hot die forging

2021 ◽  
Vol 2131 (5) ◽  
pp. 052013
Author(s):  
E Galsanova ◽  
A Greshilov ◽  
Ya Kalinin ◽  
A Yakovlev

Abstract Methods of mathematical modeling, basic technologies and methods of modeling in various design systems of the stamping process are considered. The canonical equations of temperature stresses are obtained, which make it possible to obtain a picture of the temperature distribution over the workpiece area during heating. A mathematical model has been developed for a thin metal strip during heating; thermal stresses arising in it due to uneven heating have been described. Numerical modeling has been carried out on the basisof field data, which will allow verification of the automated environment for the selection of functional and design schemes and the calculation of the parameters of heating devices in hot volumetric stamping of workpieces in terms of speed, energy efficiency, heating quality: accuracy of achieving specified temperatures and maximum heating uniformity. By areas, ease of use and readjustment, resource, reliability and maintainability. The proposed system will include the following CAD elements: databases and rules for operating with them, calculation modules, modules for selecting and matching options.

1969 ◽  
Vol 91 (3) ◽  
pp. 516-521 ◽  
Author(s):  
A. Seireg ◽  
H. Ezzat

This paper presents an automated system for the selection of the length, clearance, and lubricant viscosity which optimize the performance of a hydrodynamic journal bearing, under specified values or ranges of load and speed. The study illustrates the feasibility of applying optimal programming techniques for the development of bearing design systems.


2020 ◽  
pp. 20-31
Author(s):  
A. A Burenin ◽  
A. V Tkacheva

The work aims at solving the problem of the theory of unsteady thermal stresses simulating the assembling of the two-layer elastoplastic pipe using the shrink fit (Gadolin problem). The plastic flow condition is taken in the form of a piecewise linear condition of maximum reduced stresses (the Ishlinsky - Ivlev condition) with a parabolic yield point depending on temperature. It is shown that when solving the mechanical part of a disconnected problem of the theory of temperature stresses, the calculations of reversible and irreversible deformations and stresses can be carried out numerically, i.e. analytically without resorting to approximate calculation procedures and, therefore, without discretizing the computational domains. We present a diagram of the emergence and disappearance of plastic flow regions under the assembly conditions and its subsequent cooling. With a different choice of problem parameters, some plastic regions may not appear. However, it is impossible to obtain other areas of plastic flow by changing the geometry of the problem, properties of assembly materials, and the level of heating. This is the adequacy of the calculations. Only those plastic areas that are shown in the diagram appear and disappear. In contrast to the classical case of uniform heating of the outer pipe, this article deals with a widely used case of an uneven heating of the outer pipe from the inner surface. In this case, irreversible deformations are calculated, and then taken into account, which originated in the pipe material before the moment of landing. A comparison of the distribution of residual stresses obtained during the uniform and non-uniform heating of the outer pipe is given. As a result, the interference with the uniform heating exceeds the interference formed with the non-uniform heating of the pipe.


2016 ◽  
Vol 8 (1) ◽  
pp. 75-91 ◽  
Author(s):  
Shelby Devina ◽  
Waluyo Waluyo

The objective of this research was to examine the effect of perceived usefulness, perceived ease of use, speed, security and privacy and readiness technology tax payers information to e-Filing usage. The object of this study is the individual tax payers in Tangerang City, Karawaci District. The selection of the sample is determined based on convenience sampling method. Data used in this study was primary data, id est: questionnaires. The respondent in this study were 110. Data analysis technique in this study using multiple linear regression. The result of this study were (1) perceived usefulness have a significant impact towards e-Filing usage; (2) perceived ease of use have a significant impact towards e-Filing usage; (3) speed does not have a significant impact towards e-Filing usage; (4) security and privacy does not have a significant impact towards e-Filing usage; (5) readiness technology tax payers information does not have a significant impact towards e-Filing usage; (6) perceived usefulness, perceived ease of use, speed, security and privacy and readiness technology tax payers information all simultaneously, have a significant impact towards e-Filing usage. Keywords: e-Filing usage, perceived usefulness, perceived ease of use, readiness technology tax payers information, security and privacy.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Huojie Shi ◽  
Hui Chen ◽  
Zhiming Yan

Abstract Radio frequency (RF) sterilization of low-moisture, high-oil, high-protein, and viscous sauces for instant food (LHHVS) demonstrates many advantages, but uneven heating is a main problem that must be addressed. Main factors that affect heating uniformity are generally considered dielectric properties, shape and size of the sample and its position relative to the electrode plate, in addition the structure and voltage of RF electrode. A method based on texture characteristics of the solid–gel–liquid mixing system of LHHVS for adjustment and control of energy distribution in the RF field is proposed in this study to improve the heating uniformity. First, energy conversion principles and control equations of RF heating were analyzed on the basis of dielectric theory. Second, the influence of RF electromagnetic field-medium polyetherimide (PEI) on the RF heating of peanut butter (RHPB) was investigated on the basis of the numerical model of RHPB that was verified through experiments. Finally, the influence mechanism and its regulation and control effect were analyzed and discussed. The following conclusions can be drawn from this study: the increase of electrode gaps exerts minimal effect although it reduces the unevenness of the energy distribution. However, RF heating protocols must use the smallest possible electrode gap to heat agrifoods and increase the heating rate significantly. The energy distribution on the part of the sample close to PEI varies with the change of geometry and size of PEI when its placement is bias or symmetric. The area of energy enhancement continues to expand where the sample is in contact with PEI as PEI gradually increases. The area where the temperature increases under the influence of PEI will expand along the direction of the sample radius when the thickness of PEI remains unchanged and the radius gradually enlarges; otherwise, it will expand along the direction of the sample thickness. The influence of PEI on the energy distribution of RHPB demonstrates local characteristics. PEI significantly influences the energy distribution and heating mode of RHPB, which is easy to adjust and control, but does not reduce the processing speed and does not increases energy consumption. Hence, PEI is an effective means to interfere with energy distribution of RHPB. Uniform energy distribution can be obtained by selecting the appropriate PEI shape and size. Results of this study can help determine the experimental protocol for RHPB with the optimal uniform distribution and promote the fast commercial application of this technology.


Author(s):  
Tatyana A. Erina ◽  
Natalya N. Motkina

Researchers in the humanities almost always have to deal with the problem of statistical processing of results and their interpretation. This is a rather laborious and painstaking work, which can be greatly simplified through the use of multifunctional statistical criteria. Within the framework of the study related to the problem of self-design of educational and professional ac-tivities of students, the analysis of the effectiveness of the introduction of technological elements using multifunctional criteria was carried out: φ* criterion – Fisher’s angular transformation and binomial criterion m. The statistical significance of the results of the introduction at a certain stage of the technology of the workshop is revealed, which makes it possible to study and apply the ele-ments of self-management in the educational and professional activities of students. For promising purposes, it is proposed to create an automated system that implements the selection of the appropriate criterion for the problem to be solved and the verification of the statistical hypothesis put forward by the researcher.


2006 ◽  
Vol 41 (3) ◽  
pp. 283-295 ◽  
Author(s):  
Renaud Quilbé ◽  
Alain N. Rousseau ◽  
Pierre Lafrance ◽  
Jacinthe Leclerc ◽  
Mohamed Amrani

Abstract Numerous models have been developed over the last decades to simulate the fate of pesticides at the watershed scale. Based on a literature review, we inventoried thirty-six models categorized as management, research, screening or multimedia models, each of them having specific strengths and weaknesses. Given this large number of models, it may be difficult for potential users (stakeholders or scientists) to find the most suited one with respect to their needs. To help in this process, this paper proposes a pragmatic approach based on a multi-criteria analysis. Selection criteria are defined following the user's needs and classified in five classes: modelling characteristics, output variables, model applicability, possibilities to simulate best management practices (BMPs) and ease of use. The relative importance of each criterion is quantified by a weight and the total score of a model is calculated by adding the resulting weights of satisfied criteria. This selection framework is illustrated with a case study that consists in selecting a model to develop water quality standards at the watershed scale with respect to the implementation of BMPs. This resulted in the selection of three models: BASINS, SWAT and GIBSI.


2021 ◽  
Author(s):  
Akash Gajanan Prabhune ◽  
Aishwarya Mallavaram ◽  
Sachin Bhat ◽  
Samridhi Pandey ◽  
Ayesha Mehar Shagufta ◽  
...  

Abstract Background: The objective of this paper was to evaluate the COVID-19 vaccine registration website across UN-recognized member states for their portal quality, reliability, Ease Use and help to the general population in informed decision making.Methods: 12 UN member states (Countries) were selected based on the inclusion and exclusion criteria mentioned in the methodology section of this paper. PPS technique was used for sampling and selection of 12 countries from 193 UN member states. Post selection of UN member states the study used 2 step evaluation techniques, Step 1 The DISCERN checklist consists of 16 questions in three sections and is aimed to assess the reliability of information and quality of information; Step 2 The QUEST tool consists of 6 items with a subitem, Authorship, Attribution, Conflict of Interest, Complementarity, Currency, Tone. The authors developed a standard set of instructions for evaluating Vaccination Portals to bring uniformity in understanding and context setting.Results: DISCERN tool overall reliability score on the Likert scale of 0 to 5 was 4 (SD ± 1.28). On Quality of information regarding treatment choices, the average score was 3.4 (SD ± 1.67). The QUEST tool on ease of use, concision, and comprehensiveness demonstrated an average score of 18.1 (SD ± 8.3) out of 28.The vaccine registration portal of the Czech Republic was found to be most informative and was able to provide a piece of scientifically valid information on safety, efficacy, long-term short effects, choice of vaccine with attributable authors details. India, Bangladesh, Nigeria, South Africa scored relatively low to missing critical information on the website. The United Arab Emirates, Republic of South Korea, Indonesia, Australia, and Argentina had minor elements missing.Conclusions: COVID-19 vaccination portals vary in the quality of information and many were found unable to provide critical information for decision making on getting vaccinated


Author(s):  
Linda E. Cammish ◽  
Steven A. Kates

The concept of solid phase peptide synthesis introduced by Merrifield in 1963 involves elongating a peptide chain on a polymeric support via a two-step repetitive process: removal of the Nα-protecting group and coupling of the next incoming amino acid. A second feature of the solid phase technique is that reagents are added in large excesses which can be removed by simple filtration and washing. Since these operations occur in a single reaction vessel, the entire process is amenable to automation. Essential requirements for a fully automatic synthesizer include a set of solvent and reagent reservoirs, as well as a suitable reaction vessel to contain the solid support and enable mixing with solvents and reagents. Additionally, a system is required for selection of specific solvents and reagents with accurate measurement for delivery to and removal from the reaction vessel, and a programmer to facilitate these automatic operations is necessary. The current commercially available instruments offer a variety of features in terms of their scale (15 mg to 5 kg of resin), chemical compatibility with 9-fluorenylmethyloxycarbonyl/tert-butyl (Fmoc/tBu) and tert-butyloxycarbonyl/ benzyl (Boc/Bzl)-based methods, software (reaction monitoring and feedback control), and flexibility (additional washing and multiple activation strategies). In addition, certain instruments are better suited for the synthesis of more complex peptides such as cyclic, phosphorylated, and glycosylated sequences while others possess the ability to assemble a large number of peptide sequences. The selection of an instrument is dependent on the requirements and demands of an individual laboratory. This chapter will describe the features of the currently available systems. As the field of solid phase synthesis evolved, manufacturers designed systems based on the synergy between chemistry and engineering. A key component to an instrument is the handling of amino acids and their subsequent activation to couple to a polymeric support. The goal of an automated system is to duplicate conditions that provide stability to reactive species that might decompose. Standard protocols for automated synthesis incorporate carbodiimide, phosphonium, and aminium/uronium reagents, preformed active esters, and acid fluorides. For further details on coupling methods, see Chapter 3. A second issue related to coupling chemistry is the time required to dissolve an amino acid and store this solution.


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