scholarly journals Determination of the Overturning Torque of the Cutting Forces of the Knife Actuating Device of the Geokhod

2021 ◽  
Vol 315 ◽  
pp. 03020
Author(s):  
Vladimir Aksenov ◽  
Vladimir Sadovets ◽  
Vyacheslav Beglyakov ◽  
Dmitry Pashkov ◽  
Elena Rezanova
Keyword(s):  
Cutting Forces ◽  
Rotation Axis ◽  
Critical Values ◽  
Total Moment ◽  
Axis Of Rotation ◽  
Mining Conditions ◽  
The Face ◽  
Moment Of Resistance ◽  
Destruction Of Rocks

The paper considers the relevance of the research, indicated by the authors in the title of the article. As a result of the studies carried out, it was found that the overturning torque of the cutting forces occurs as a result of the imbalance of the system of cutting forces during the destruction of rocks by the actuating device of the geokhod. It was revealed that the value of the critical overturning torque of cutting forces is influenced by two force factors; this is the projection of the resistance of the soil to cutting on a plane perpendicular to the axis of rotation, as well as the total moment of resistance to cutting. As a result of the study, the critical values of the withdrawal force and overturning torque were obtained for specific mining conditions for the development and the specified geometric parameters of the actuating device of the geokhod. The resulting withdrawal force during the destruction of the face rock by the actuating device causes a deviation of the axis of geokhod rotation from the axis of the working’s route. Therefore, it becomes necessary to constantly monitor the deviation of the geokhod rotation axis from the axis of the working’s route, and, if necessary, to correct the geokhod displacement.

scholarly journals Determination of the Vertical Dimension and the Position of the Occlusal Plane in a Removable Prosthesis Using Cephalometric Analysis and Golden Proportion

2021 ◽  
Vol 11 (15) ◽  
pp. 6948
Author(s):  
Gabriele Cervino ◽  
Sergio Sambataro ◽  
Chiara Stumpo ◽  
Salvatore Bocchieri ◽  
Fausto Murabito ◽  
...  
Keyword(s):  
Vertical Dimension ◽  
Occlusal Plane ◽  
X Rays ◽  
Common Procedure ◽  
Lower Incisor ◽  
Golden Proportion ◽  
The Face ◽  
Removable Prosthesis ◽  
Edentulous Patients

The aim of this study is to demonstrate the use and the effectiveness of cephalometry and golden proportions analysis of the face in planning prosthetic treatments in totally edentulous patients. In order to apply this method, latero-lateral and posterior-anterior X-rays must be performed in addition to the common procedure. Two main concerns for totally edentulous patients are the establishment of the vertical dimension and the new position of the occlusal plane. The divine proportion analysis was carried out by the use of a golden divider. The prosthetic protocol was divided into three steps and a case was selected for better understanding. Referring to the golden relations, if the distance from the chin to the wing of the nose is 1.0, the distance from the nose to eye is 0.618. This proportion is useful and effective in determining the correct prosthetic vertical dimension. The incisal margin of the lower incisor must be positioned between Point A (A) and protuberance menti (Pm) according to the gold ratio 0.618 of the total height A-Pm. Posteriorly the occlusal plane must be placed 2 mm below the divine occlusal plane (traced from the incisal margin of lower incisors to Xi point). A prosthesis made in accordance with cephalometric parameters and divine proportions of the face helps to improve the patient’s aesthetics, function and social personality.

scholarly journals Kemampuan Lulusan Sekolah Tinggi Pariwisata Ampta Dalam Menghadapi Persaingan Di Dunia Kerja

Media Wisata ◽  
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sri Larasati
Keyword(s):  
Communication Skill ◽  
Total Population ◽  
Sampling Technique ◽  
Regression Equations ◽  
Test Results ◽  
A Value ◽  
The Face ◽  
Job Competition ◽  
Sampling Approach

The purpose of this research is to know wtether knowledge, skill, responsiveness and communication skill influence in job competition for graduate student from Sekolah Tinggi Pariwisata AMPTA. The population in this study are student pf Sekolah Tinggi Pariwisata SMPTA that graduated in 2013 until 2016, the total population in this studt is 702 and 200 respondents who have worked taken as samples, samples were taken with non probability sampling technique and accidental sampling approach. Sampling approach using regression equations obtained results that through test results F (regression analysis jointly) may note that the value of F = 147.104 count with the significance of 0.000 < 0.05. The test results of the test F reinforced with testing the determination of the coefficient that shows the value of 74.6%) (0.746. From Test t (partially) can result in variable knowledge with a value of t = 3,173 and significance of the value 0002 < 0.05, variable skill with a value of t = 2,949 and value the significance of 0.004 < 0.05, variable attitude with a value of t = 2,688 and value the significance of 0.008 < 0.05, variable communication skill with a value of t = value and significance of 4,497 0000 < 0.05. From the above results can be known that the hypothesis posed was not proven in other words that all of these variables can be said to have a positive and significant effect simultaneously as well as partial toward the ability of STP graduates AMPTA in the face of competition in the world of work

scholarly journals INVESTIGATION OF THE GEOMECHANICAL STATE OF SOFT ADJOINING ROCKS UNDER PROTECTIVE CONSTRUCTIONS

2021 ◽  
Vol 36 (4) ◽  
pp. 61-71
Author(s):  
Serhii Nehrii ◽  
Tetiana Nehrii ◽  
Oksana Zolotarova ◽  
Serhii Volkov
Keyword(s):  
Physical And Mechanical Properties ◽  
New Approach ◽  
Soft Rocks ◽  
The Face ◽  
Geomechanical State ◽  
Rock Mass Failure ◽  
The Stability ◽  
Seam Mining ◽  
Mine Roadways

The conditions of coal seam mining in the mines of Ukraine have been considered. The problem of conducting coal mining by longwalls in the conditions of soft adjoining rocks, which concerns the protection of mine roadways located near the face, has been revealed. In such conditions, the existing protective constructions are ineffective due to the fact that they yield and get pressed into the soft rocks of the footwall. This indicated the need for research into the geomechanical state of soft rocks of the footwall. According to the results of known studies on the mechanism of rock mass failure around roadways and the data of physical and mechanical properties of the coal mass, which is represented by soft rocks, the correlation dependence has been obtained, the use of which allowed for the determination of the parameters of the rock deformation diagram and the establishment of the stability criterion of footwall rocks under the protection means and stability conditions of the geotechnical system “protective construction – adjoining rocks.” They are the basis of a new approach to ensure the stability of the roadways, which are supported behind the faces, by controlling the stress state in the system “protective construction – adjoining rocks.” This may be the basis for the development of new methods of protecting roadways in conditions of soft adjoining rocks.

scholarly journals Experimental Assessment of the Depth of the Deformed Layer in the Roller Burnishing Process

2019 ◽  
Vol 290 ◽  
pp. 03008
Author(s):  
Marek Kowalik ◽  
Tomasz Trzepiecinski
Keyword(s):  
Cross Section ◽  
Precise Determination ◽  
Roller Burnishing ◽  
Elastic Zone ◽  
Original Measurement ◽  
The Face ◽  
Burnishing Process ◽  
Deformed Layer ◽  
Slight Deformation

This paper presents the methods of experimental determining the depth of the plastically deformed top layer in the roller burnishing process. Precise determination of the depth of the plastically deformed layer is difficult due to slight deformation at the boundary of the plastic and elastic zone, the lack of visible changes in the microstructure, and minimal changes in microhardness. The article shows the method of original measurement method that consists in determining the thickness of the deformed layer using rings. The method involves the profilographometric measurements of the disconnected rings (samples) which are flat-faced in the package on the mandrel. The rings material deforms plastically in the surface layer causing wrapping of the end face of the ring in the direction of the rolling tool movement. After dismantling the ring pack, measurements were made on the face of each ring along radial directions, and the thickness of the deformed layer was observed on the microscope. The method was verified by microhardness measurements in the cross-section and cross-section of the ring. The results of deformation depth measurements were verified by finite-element-based numerical simulation.

Assuming the Conclusions: Risk Assessment in the Development of Cancer Policy

1985 ◽  
Vol 4 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Mark E. Rushefsky
Keyword(s):  
Risk Assessment ◽  
Risk Management ◽  
Policy Development ◽  
Cancer Risk Assessment ◽  
Acceptable Risk ◽  
Policy Documents ◽  
The Face ◽  
Assessment Guidelines ◽  
Objective Determination

This article examines the development of generic cancer risk assessment guidelines, or cancer policy, from 1976-1984. Risk assessment is considered the objective determination of the degree of risk from a substance. Risk management is the subjective determination of acceptable risk. However, uncertainties in the scientific foundations of cancer policy necessitate risk assessment inference choices, for example, over appropriate dose-response extrapolation models. Those choices are only partially scientific; they are also partially political. There is, as a result, an inevitable mixture of facts and values in cancer policy. The article explores ten inference controversies and evaluates how nine cancer policy documents resolved those controversies. It then traces the course of cancer policy development, showing how the Carter and Reagan administrations produced policies with difference emphases and considers several major challenges to cancer policy. The article then provides several justifications for cancer policy in the face of those challenges. It suggests, in the conclusion, that the controversies are unlikely to be resolved by science alone and politics will continue to influence the content of cancer policies.

scholarly journals Solution for the Location of Rock Cutting Elements Relative to the Rotation Center of Geohod

2019 ◽  
Vol 105 ◽  
pp. 03001 ◽  
Author(s):  
Valery Nesterov ◽  
Vladimr Aksenov ◽  
Vladimir Sadovets ◽  
Dmitry Pashkov
Keyword(s):  
Cutting Forces ◽  
Complex Shape ◽  
Rock Cutting ◽  
General Information ◽  
Technical Solution ◽  
Helical Surface ◽  
Body Form ◽  
Rotation Center ◽  
Different Types ◽  
The Face

The article presents the technical solution for the location of cutting elements relative to the rotation center of Geohod for destructing rocks with a strength up to 1 of Protodyakonov hardness. The relevancy of the research is considered. General information about Geohod is given. The features of working body of Geohod are described, in particular, the formation of a complex shape of the face and the working body, and it is also said that in the case of screw movement of working body of Geohod to the face, the points of working body form a helicoidal (helical) surface. To set the purpose and objectives of the study the geometric parameters of generatrix are justified. The parameter depending on the number of blades and on the radius of location of the blade’s cut is identified. Based on the study, the dependence of the number of blades on their location from the center to the periphery is determined. The design of blade working body of Geohod for rocks with a strength f <1 of Protodyakonov hardness is offered. Also the directions for further research have been identified, which include: the development of methods for calculating cutting forces for a technical solution for the location of cutting elements relative to the center of rotation of Geohod for destructing rocks up to 1 of Protodyakonov hardness; the application of this technique for obtaining variants of the blade working body of Geohod of different types.

scholarly journals A Determination of Pulsar Emission Geometry from Polarization Observations

1992 ◽  
Vol 128 ◽  
pp. 400-403
Author(s):  
Xinji Wu ◽  
Wen Xu
Keyword(s):  
Inclination Angle ◽  
Pulse Width ◽  
Rotation Axis ◽  
Geometrical Model ◽  
Polarization Angle ◽  
Radiation Beam ◽  
Pulsar Emission ◽  
Magnetic Inclination ◽  
Large Pulse

AbstractOne of the important problems in pulsar studies is to determine the magnetic inclination angle α, the intrinsic width of the radiation beam (2ρ) and the angle (α + β) between the observer's direction and the rotation axis. In this paper we solve this problem for individual pulses by using the observed pulse width (2Δ𝜙), the swing of polarization angle (2Δψ), and its central gradient (dψ/d𝜙)max.From the polar cap model we establish three basic geometrical relations, a complete set of equations from which explicit solutions can be obtained using the observed data. This is the first time that the orientation of pulsar emission is solved analytically solely on the basis of a geometrical model. However, the results are shown to be sensitively connected to the polarization-angle swing (2Δψ), which is not well measured for most pulsars. So the number of pulsars to which our method can be applied is limited. The importance of the measurement of Δψ is seen from our method. To ensure the credibility of our results, we have discussed the conditions to be satisfied by all reliable pulsar measurements. Our method is shown to be more favorable for pulsars with large pulse width 2Δ𝜙, large central gradient (dψ/d𝜙)max and large magnetic inclination angle α. Out of 120 pulsars (from Lyne and Manchester 1988), 40 are solvable, and 7 are believed to be reliable. We discuss our method for the determination of pulsar geometry in comparison with other methods.

scholarly journals Analysis of the Influence of Terrain Orientation on the Design of PV Facilities with Single-Axis Trackers

2020 ◽  
Vol 10 (23) ◽  
pp. 8531
Author(s):  
Francisco J. Gómez-Uceda ◽  
Isabel M. Moreno-Garcia ◽  
José M. Jiménez-Martínez ◽  
Rafael López-Luque ◽  
Luis M. Fernández-Ahumada
Keyword(s):  
Solar Irradiance ◽  
Energy Production ◽  
Rotation Axis ◽  
The South ◽  
Axis Of Rotation ◽  
Axis Parallel

This paper investigates how to optimally orient the photovoltaic solar trackers of an axis parallel to the terrain, applying the sky model of Hay–Davies. This problem has been widely studied. However, the number of studies that consider the orientation (inclination and azimuth of the terrain) is very limited. This paper provides an examination of incident solar irradiance that can be extended to terrain with variable orientation and in consideration of different azimuths of the axis of rotation. Furthermore, a case study of the south of Spain is provided, considering different inclination and orientation terrain values. The results obtained in this study indicate, as a novelty, that for lands that are not south facing, the rotation axis azimuth of solar trackers should be different from zero and adjusted to the same direction as the land azimuth in order to maximize energy production. Annual energy production is sensitive to changes in the rotation axis azimuths of solar trackers (an influence of around 3% of annual energy production).

Helioseismic Determination of the Solar Rotation Axis

2005 ◽  
Vol 621 (2) ◽  
pp. L153-L156 ◽  
Author(s):  
J. G. Beck ◽  
P. Giles
Keyword(s):  
Rotation Axis ◽  
Solar Rotation
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