On the Determination of Basic Dimensions of a Cam With a Translating Roller-Follower

2004 ◽  
Vol 126 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Anirvan DasGupta ◽  
Amitabha Ghosh
Keyword(s):  
Detailed Analysis ◽  
Constant Pressure ◽  
Graphical Method ◽  
Point Of View ◽  
Numerical Example ◽  
Pressure Angle ◽  
The Common ◽  
Optimal Values

The problem of determination of basic dimensions from the point of view of follower jamming of a cam with translating roller-follower is addressed. Departing from the common practice of using only a constant pressure angle to assess jamming of the follower in its guide, this paper presents a detailed analysis of the problem taking into consideration the follower-guide friction. This leads to new bounds on the pressure angle. Based on the bounds obtained, a graphical method for determination of the optimal values of the basic dimensions is proposed. A numerical example is presented for the purpose of illustration.

Application of the Theory of Envelope to the Determination of Camoid Profiles With Translating Followers

1992 ◽  
Author(s):  
Der Min Tsay ◽  
Guan Shyong Hwang
Keyword(s):  
Simple Procedure ◽  
Contact Point ◽  
Machining Process ◽  
Analytical Expression ◽  
Numerical Example ◽  
Pressure Angle ◽  
Independent Parameters

Abstract A new, simple procedure employing the theory of envelope for a family of surfaces with two independent parameters to determine the profiles of camoids with translating spherical followers is presented. Given the follower motion program, the method enables the camoid surface coordinates to be easily generated in an analytical expression. The results are then compared to those obtained by utilizing the principle of contact point between the camoid and the follower surfaces. The pressure angle is analyzed, and the cutter paths required in the machining process are also produced. A numerical example is given to illustrate the application of the approach.

scholarly journals MODELLING AND OPTIMIZATION OF WAVEGUIDE POLARIZERS WITH THE ACCOUNT OF IRISES THICKNESS

2020 ◽  
Author(s):  
Andrew Bulashenko ◽  
◽  
Stepan Piltyay ◽  
Keyword(s):  
Mathematical Model ◽  
Axial Ratio ◽  
Engineering Problem ◽  
Point Of View ◽  
Design Parameters ◽  
Differential Phase Shift ◽  
Polarization Characteristics ◽  
Electromagnetic Characteristics ◽  
Optimal Values

Today, there is a continuous improvement of modern satellite telecommunication systems caused by the requirements of constantly increasing information volumes. The fundamental elements of such systems are antennas with polarization processing of signals. This processing is mainly performed using microwave waveguide polarizers and orthomode transducers. Therefore, the development and optimization of new waveguide polarizers is a relevant engineering problem. The simplest from the technological point of view are the polarizers based on waveguides with irises. Analysis and optimization of electromagnetic characteristics of a polarizer based on a square waveguide with irises are the goals of the presented research. To solve this optimization problem we have created a new mathematical model, which allows to investigate the influence of the design parameters of the polarizer on its electromagnetic characteristics. A new mathematical model of the polarizer based on square waveguide with irises was created using wave transmission and scattering matrices of the structure elements. Developed mathematical model takes into account the thickness of the irises. A new mathematical model of a waveguide polarizer is based on the general wave scattering matrix. This matrix was calculated using the theory of microwave circuits. The main characteristics of the square waveguide polarizer were expressed through the elements of this matrix. The developed new mathematical model of a square waveguide polarizer with irises takes into account the heights of the irises, the distances between them and their thickness. The new mathematical model is simpler and faster for the determination of the electromagnetic characteristics of the waveguide polarizer compared to the finite integration technique, which is often applied to analyze microwave devices for various purposes. In addition, developed new mathematical model of the waveguide iris polarizer allows to estimate the variations of all required electromagnetic characteristics if the structure parameters deviate from their optimal values. Using the created mathematical model we have carried out the optimization of the polarizer matching and polarization characteristics in the operating satellite Ku-band 10.7–12.8 GHz. Simulated optimum design of the waveguide polarizer provides VSWR for horizontal and vertical polarizations less than 3.26. Optimized differential phase shift is 90° ± 4.2°. Axial ratio of the waveguide iris polarizer is less than 1.43 dB. Corresponding XPD is higher than 21.7 dB.

Application of the Theory of Envelope to the Determination of Camoid Profiles With Translating Followers

1994 ◽  
Vol 116 (1) ◽  
pp. 320-325 ◽  
Author(s):  
Der Min Tsay ◽  
Guan Shyong Hwang
Keyword(s):  
Simple Procedure ◽  
Contact Point ◽  
Machining Process ◽  
Analytical Expression ◽  
Numerical Example ◽  
Pressure Angle ◽  
Kinematic Relationship ◽  
Independent Parameters

A new, simple procedure employing the theory of envelope for a family of surfaces with two independent parameters to determine the profiles of camoids with translating spherical followers is presented. Given the follower motion program, the method enables the kinematic relationship for the camoid surface coordinates to be easily generated in an analytical expression. The results are then compared to those obtained by utilizing the principle of contact point between the camoid and the follower surfaces. The pressure angle is analyzed, and the cutter paths required in the machining process are also produced. A numerical example is given to illustrate the application of the approach.

Bipartisanship as Possible Alternative of Russian Political System Evolution

2018 ◽  
Vol 42 ◽  
pp. 256-265
Author(s):  
Konstantin V. Simonov ◽  
Stanislav P. Mitrakhovich
Keyword(s):  
United States ◽  
Detailed Analysis ◽  
Political System ◽  
Party System ◽  
Political Competition ◽  
The United States ◽  
Point Of View ◽  
Complex Structures ◽  
Practical Advice ◽  
Simultaneous Separation

The article examines the possibility of transfer to bipartisan system in Russia. The authors assess the benefits of the two-party system that include first of all the ensuring of actual political competition and authority alternativeness with simultaneous separation of minute non-system forces that may contribute to the country destabilization. The authors analyze the accompanying risks and show that the concept of the two-party system as the catalyst of elite schism is mostly exaggerated. The authors pay separate attention to the experience of bipartisan system implementation in other countries, including the United States. They offer detailed analysis of the generated concept of the bipartisanship crisis and show that this point of view doesn’t quite agree with the current political practice. The authors also examine the foreign experience of the single-party system. They show that the success of the said system is mostly insubstantial, besides many of such systems have altered into more complex structures, while commentators very often use not the actual information but the established myths about this or that country. The authors also offer practical advice regarding the potential technologies of transition to the bipartisan system in Russia.

A Graphical Method for Storage Coefficient Determination from Quasi-Steady State Flow Data

1996 ◽  
Vol 27 (4) ◽  
pp. 247-254 ◽  
Author(s):  
Zekâi Şen
Keyword(s):  
Steady State ◽  
Graphical Method ◽  
Pumping Test ◽  
Quasi Steady State ◽  
Flow Data ◽  
Steady State Flow ◽  
Storage Coefficient ◽  
State Flow ◽  
Aquifer Test

A simple, approximate but practical graphical method is proposed for estimating the storage coefficient independently from the transmissivity value, provided that quasi-steady state flow data are available from a pumping test. In the past, quasi-steady state flow distance-drawdown data have been used for the determination of transmissivity only. The method is applicable to confined and leaky aquifers. The application of the method has been performed for various aquifer test data available in the groundwater literature. The results are within the practical limits of approximation compared with the unsteady state flow solutions.

NMR Determination of the Structure of Peracetylated Icariside B2 from Veratrum Lobelianum BERNH.

1995 ◽  
Vol 60 (8) ◽  
pp. 1380-1385 ◽  
Author(s):  
Václav Suchý ◽  
Miloš Buděšínský ◽  
Karel Ubik ◽  
Daniel Grančai ◽  
Vlasta Földešiová
Keyword(s):  
Detailed Analysis ◽  
Nmr Spectra ◽  
Aerial Part ◽  
C Nmr

rel(1S,4S,5R)-3,3,5-Trimethyl-4-[( 1E)-3-oxo-1-butenyl]-4,5-epoxy-cyclohexyl-O-β-D-glucopyranoside (I) was isolated from the aerial part of Veratrum lobelianum BERNH. The structure was derived mainly from detailed analysis of 1H and 13C NMR spectra of its acetylated derivative II. Compound I has been already reported under the name icariside B2in Epimedium grandiflorum MORR. var. thunbergianum (MIQ.) NAKAI.

Funerary Ritual

2019 ◽  
pp. 292-309
Author(s):  
Mireia López-Bertran
Keyword(s):  
Point Of View ◽  
Good Death ◽  
Social Implications ◽  
Archaeological Remains ◽  
Deceased Person ◽  
Funerary Rituals ◽  
The Social ◽  
The Common ◽  
Funerary Rites ◽  
Written Sources

This chapter explores the funerary rites in the Phoenician-Punic world from a comprehensive point of view, and it focuses on the common points arising from a large amount of data. The concern for burying their deceased and the belief in the soul’s afterlife show that the Phoenicians considered death as a transformation rather than as the end of a person’s life. Through our access to archaeological remains and written sources, we can reconstruct the existence of a meaningful burial program that was destined to provide a “good death” and afterlife. Funerary rituals, thus, are the actions or gestures to achieve this goal. The aim of this chapter is to explain the rites that family members undertook once someone died, in order to transform correctly the deceased person into an otherworldly being, the ancestor. The social implications of the data arising from burials are also briefly considered.

scholarly journals Evaluation of the Ability to Accurately Produce Angular Details by 3D Printing of Plastic Parts

Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 150
Author(s):  
Andrei Marius Mihalache ◽  
Gheorghe Nagîț ◽  
Laurențiu Slătineanu ◽  
Adelina Hrițuc ◽  
Angelos Markopoulos ◽  
...  
Keyword(s):  
3D Printing ◽  
Point Of View ◽  
Vertex Angle ◽  
Function Type ◽  
Constant Height ◽  
3D Printers ◽  
3D Printed ◽  
Mathematical Processing ◽  
Plastic Parts

3D printing is a process that has become widely used in recent years, allowing the production of parts with relatively complicated shapes from metallic and non-metallic materials. In some cases, it is challenging to evaluate the ability of 3D printers to make fine details of parts. For such an assessment, the printing of samples showing intersections of surfaces with low angle values was considered. An experimental plan was designed and materialized to highlight the influence of different factors, such as the thickness of the deposited material layer, the printing speed, the cooling and filling conditions of the 3D-printed part, and the thickness of the sample. Samples using areas in the form of isosceles triangles with constant height or bases with the same length, respectively, were used. The mathematical processing of the experimental results allowed the determination of empirical mathematical models of the power-function type. It allowed the detection of both the direction of actions and the intensity of the influence exerted by the input factors. It is concluded that the strongest influence on the printer’s ability to produce fine detail, from the point of view addressed in the paper, is exerted by the vertex angle, whose reduction leads to a decrease in printing accuracy.

Determination of a Rubber-Like Material Model as an Inverse Problem

2011 ◽  
Vol 70 ◽  
pp. 225-230 ◽  
Author(s):  
Agnieszka Derewonko ◽  
Andrzej Kiczko
Keyword(s):  
Selection Process ◽  
Axial Stress ◽  
Constitutive Models ◽  
Material Model ◽  
Polyester Fabric ◽  
Point Of View ◽  
Air Cushion ◽  
Ill Conditioning ◽  
Stress States

The purpose of this paper is to describe the selection process of a rubber-like material model useful for simulation behaviour of an inflatable air cushion under multi-axial stress states. The air cushion is a part of a single segment of a pontoon bridge. The air cushion is constructed of a polyester fabric reinforced membrane such as Hypalon®. From a numerical point of view such a composite type poses a challenge since numerical ill-conditioning can occur due to stiffness differences between rubber and fabric. Due to the analysis of the large deformation dynamic response of the structure, the LS-Dyna code is used. Since LS-Dyna contains more than two-hundred constitutive models the inverse method is used to determine parameters characterizing the material on the base of results of the experimental test.

Resistance to Outflow of Cerebrospinal Fluid Determined by Bolus Injection Technique and Constant Rate Steady State Infusion in Humans

Neurosurgery ◽  
1985 ◽  
Vol 16 (3) ◽  
pp. 336-340 ◽  
Author(s):  
Michael Kosteljanetz
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Bolus Injection ◽  
Point Of View ◽  
Injection Technique ◽  
Communicating Hydrocephalus ◽  
Constant Rate ◽  
High Degree ◽  
Infusion Technique

Abstract Two methods for the determination of resistance to the outflow of cerebrospinal fluid, the bolus injection technique and the constant rate steady state infusion technique, were compared. Thirty-two patients with a variety of intracranial diseases (usually communicating hydrocephalus) were studied. There was a high degree of correlation between the resistance values obtained with the two methods, but values based on the bolus injection technique were systematically and statistically significantly lower than those obtained with the constant rate infusion test. From a practical point of view. both methods were found to be applicable in a clinical setting.

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