Mechanical Subsystem as Implementation of Active Reduction of Vibration

2013 ◽  
Vol 198 ◽  
pp. 657-662 ◽  
Author(s):  
Katarzyna Białas
Keyword(s):  
Vibration Reduction ◽  
System Structure ◽  
Second Phase ◽  
Parametric Synthesis ◽  
Mechanical Subsystem ◽  
System Vibration ◽  
Mechanical Elements ◽  
Definition Of ◽  
Two Stages

The main objective of this work is to present a reverse task of the dynamics of discrete vibratory mechanical systems. This task is reverse to analysis and is called structural and parametric synthesis. As a result of performing the synthesis one obtains a structure and values of individual parameters of the system of required properties. Such properties refer to the determination of individual frequencies of the system vibration. Synthesis is divided into two stages. The first stage consists in definition of the structure as well as the values of parameters of a passive system without vibration reduction. In the second phase, one selects a method of vibration reduction as well as system structure and parameters with vibration-reducing elements. In case of already-existing systems, the first stage consists in the identification of the system and its analysis. There are no changes in the second stage (Figure 1) [. Another objective of this work is to use mechanical elements in the form of kinematic excitations as the implementation of active reduction of vibration as well as to check the influence of this subsystem on the basic system. The application of the synthesis presented in this work enables the correction of the already-existing machines and devices as well as the modification of newly-created systems with the view of their future functioning.

Example of modeling the use of fire-fighting vessels

2021 ◽  
Vol 93 ◽  
pp. 183-198
Author(s):  
A. V. Kulagin ◽  
Keyword(s):  
Evaluation Criteria ◽  
Fire Fighting ◽  
Technical Equipment ◽  
Fire Extinguishing ◽  
Logical Tree ◽  
Proposed Modification ◽  
Definition Of ◽  
Two Stages ◽  
The Impact

Introduction. The article considers a systematic approach to assessing the effectiveness of the preparation and use of fire-fighting vessels. Using the Pattern method, a study of the use of a fire-fighting boat for solving problems of extinguishing fires on water transport was conducted. Goal and objectives. The purpose of the study is to improve the methodology for determining the effectiveness of the preparation and use of fire-fighting vessels according to the selected evaluation criteria, with the determination of the impact of each criterion on the overall effectiveness of fire extinguishing. Methods. In the article, the process of evaluating the effectiveness of the preparation and use of fire-fighting vessels can be divided into two stages. At the first stage, a verbal presentation of the research task is carried out with the identification of the most "weak" training measures and during the application of fire-fighting vessels using the Pattern Method. At the second stage of the study, an assessment of the state of the identified "weak" measures is carried out with the definition of measures to improve the technical readiness of the material part or organizational and technical measures during the operation of fire-fighting vessels. Results and discussion. The author obtained a particular analytical solution for improving the efficiency of operation of fire-fighting vessels for the case of using a fire-fighting boat. A method for calculating the evaluation criteria is proposed. Conclusions. Thus, the proposed modification of the model of preparation and application of fire-fighting vessels consists in the representation of organizational and technical processes in the form of a logical "tree of goals". The directions of further research in terms of the development of the results obtained in the analysis of the operation of fire-technical equipment on fire-fighting vessels and fire-fighting vessels themselves are determined. Keywords: model, system approach, analysis, pattern method, diesel, special fire extinguishing means

scholarly journals The model of the organizational and technical weapons and military equipment recovery system

2021 ◽  
Vol 11 (6) ◽  
pp. 194-208
Author(s):  
Vladimir Kotsiuruba ◽  
Vladimir Dachkovskyі ◽  
Tymur Kurtseitov
Keyword(s):  
Armed Conflicts ◽  
Rational Structure ◽  
Logistics System ◽  
Military Equipment ◽  
Recovery System ◽  
Definition Of ◽  
Two Stages ◽  
Military Units ◽  
Different Levels

Analysis of wars and armed conflicts in recent years and the performance of tasks by military units (subunits) in a United Forces operation (anti-terrorist operation) confirms that the success of the troops (forces) in performing tasks will depend on the performance of the logistics system. The availability of military units with serviceable weapons and military equipment (WME) ensures the fulfillment of the mission and the advantage over the enemy. At the same time, the timeliness of providing military units (subunits) with serviceable weapons and military equipment depends on the efficiency of the logistics system, namely, on the recovery subsystem, which is its component. However, as studies have shown, there is currently insufficient sufficiency of the recovery system. All this is related to the definition of the composition of forces and means and the structure of the WME recovery system at different levels of the hierarchy. Therefore, in the article, it is considered that for the WME recovery system, the main parameter is the allowable time of WME recovery, differentiated by levels of complexity of tasks. Determination of this parameter for the basic variant of construction of WME recovery system is proposed using the average indicator of the intensity of the flow of possible volumes of tasks on the WME recovery. To determine the rational structure of WME recovery system and to calculate its main parameters the combined method of optimization of WME recovery system was used. Containing two stages: on the first - based on the requirements to the permissible terms of WME recovery system, the rational structure of the recovery system is defined, and on the second – using the method of statistical modeling, the parameters of the structure and composition of forces and means of the WME recovery system at each level of the hierarchy are defined.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Determination of creep mechanisms in various silicon carbides via TEM

1986 ◽  
Vol 44 ◽  
pp. 484-487
Author(s):  
C. H. Carter ◽  
J. E. Lane ◽  
J. Bentley ◽  
R. F. Davis
Keyword(s):  
Heat Exchangers ◽  
Sintered Material ◽  
Polycrystalline Material ◽  
Chemical Vapor ◽  
Graphite Substrate ◽  
Second Phase ◽  
Reaction Bonding ◽  
Creep Mechanisms ◽  
Porous Sic

Silicon carbide (SiC) is the generic name for a material which is produced and fabricated by a number of processing routes. One of the three SiC materials investigated at NCSU is Norton Company's NC-430, which is produced by reaction-bonding of Si vapor with a porous SiC host which also contains free C. The Si combines with the free C to form additional SiC and a second phase of free Si. Chemical vapor deposition (CVD) of CH3SiCI3 onto a graphite substrate was employed to produce the second SiC investigated. This process yielded a theoretically dense polycrystalline material with highly oriented grains. The third SiC was a pressureless sintered material (SOHIO Hexoloy) which contains B and excess C as sintering additives. These materials are candidates for applications such as components for gas turbine, adiabatic diesel and sterling engines, recouperators and heat exchangers.

State Failure and the Political Violence Phenomenon: A Comparative Analysis of Iraq and Syria Cases

2016 ◽  
Vol 4 (2) ◽  
pp. 170 ◽  
Author(s):  
K. Eylem Özkaya Lassalle
Keyword(s):  
Cold War ◽  
Political Violence ◽  
State Failure ◽  
The Political ◽  
Collective Violence ◽  
Short Run ◽  
Definition Of ◽  
The Cold War

The concept of failed state came to the fore with the end of the Cold War, the collapse of the USSR and the disintegration of Yugoslavia. Political violence is central in these discussions on the definition of the concept or the determination of its dimensions (indicators). Specifically, the level of political violence, the type of political violence and intensity of political violence has been broached in the literature. An effective classification of political violence can lead us to a better understanding of state failure phenomenon. By using Tilly’s classification of collective violence which is based on extent of coordination among violent actors and salience of short-run damage, the role played by political violence in state failure can be understood clearly. In order to do this, two recent cases, Iraq and Syria will be examined.

DEFINITION OF TIME SPENT ON REPAIR OF BUS TRANSMISSION UNITS TAKING INTO ACCOUNT TECHNOLOGICAL EQUIPMENT RELIABILITY

2020 ◽  
Vol 2020 (9) ◽  
pp. 29-33
Author(s):  
Sergey Bulatov
Keyword(s):  
Negative Impact ◽  
Probabilistic Method ◽  
Technological Equipment ◽  
Quality And Safety ◽  
Transmission Unit ◽  
Equipment Reliability ◽  
Hours Of Work ◽  
Definition Of ◽  
Time Decrease

The paper purpose is the effectiveness estimation in the technological equipment use, taking into account its reliability and productivity for defective transmission units of buses. The problem consists in the determination of time to be spent on repair of bus transmission units taking into account technological equipment reliability. In the paper there is used a probabilistic method for the prediction bus transmission units, and also a method of the dynamics of averages which allow ensuring minimum of costs for units downtime during repair and equipment cost. The need for repair of transmission units (gear box) arises on an average after 650 hours, the average productivity of the bench makes 4.2 bus / hour. The bench fails on the average after 4600 hours of work, the average time of the bench makes 2 hours. In such a way the solution of the problem specified allows analyzing the necessity of time decrease for transmission unit repair to avoid long downtimes of buses in repair areas without negative impact upon high repair quality and safety during the further operation.

Tests of jackhammers (formation of bench techniques)

2020 ◽  
pp. 28-32
Author(s):  
V.S. Vanaev
Keyword(s):  
Impact Energy ◽  
Bench Tests ◽  
Measuring Complex ◽  
Energy Indicators ◽  
Definition Of ◽  
Determination Of Parameters ◽  
Dynamic Indicators

Development of complex determination of parameters of jackhammers at bench tests is studied. The modern support of tests of jackhammers for the purpose of definition of their energy, vibration and noise indicators is considered. Descriptions of the SORP universal bench and UIPU measuring complex are given. Keywords jackhammer, bench, tests, processing object, energy indicators, impact energy, dynamic indicators [email protected]

Actual issues of valuation of businesses of the economic entity

2017 ◽  
Vol 31 (2) ◽  
pp. 156-162 ◽  
Author(s):  
O. V. Schneider
Keyword(s):  
Discount Rate ◽  
Accurate Prediction ◽  
Economic Activities ◽  
Business Valuation ◽  
Economic Entity ◽  
The World ◽  
Definition Of

The article summarizes the main approaches in the definition of business valuation the economic entity. In the process of business valuation, taking into account the risks of financial and economic activities necessary to obtain information on what stage the owner implements the business will receive income. The most difficult task is the impossibility of accurate prediction in determining the level of income and the determination of a discount rate capitalization of future incomes due to the instability of the economy, both in the country and around the world.

scholarly journals Betweenness centrality for temporal multiplexes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Zaoli ◽  
Piero Mazzarisi ◽  
Fabrizio Lillo
Keyword(s):  
Information Flow ◽  
Real World ◽  
Betweenness Centrality ◽  
Temporal Structure ◽  
Shortest Paths ◽  
Single Layer ◽  
Distance Metric ◽  
Definition Of

AbstractBetweenness centrality quantifies the importance of a vertex for the information flow in a network. The standard betweenness centrality applies to static single-layer networks, but many real world networks are both dynamic and made of several layers. We propose a definition of betweenness centrality for temporal multiplexes. This definition accounts for the topological and temporal structure and for the duration of paths in the determination of the shortest paths. We propose an algorithm to compute the new metric using a mapping to a static graph. We apply the metric to a dataset of $$\sim 20$$ ∼ 20 k European flights and compare the results with those obtained with static or single-layer metrics. The differences in the airports rankings highlight the importance of considering the temporal multiplex structure and an appropriate distance metric.

In-Situ Study of Ti/TiN Stability under Nitrogen Anneal

1999 ◽  
Vol 564 ◽  
Author(s):  
P. W. DeHaven ◽  
K. P. Rodbell ◽  
L. Gignac
Keyword(s):  
Annealing Temperature ◽  
Time Range ◽  
Second Phase ◽  
Transformation Rate ◽  
Transformation Mechanism ◽  
Second Stage ◽  
Transmission Electron ◽  
Reaction Proceeds ◽  
Two Stages

AbstractThe effectiveness of a TiN capping layer to prevent the conversion of α-titantium to titanium nitride when annealed in a nitrogen ambient has been studied over the temperature range 300–700°C using in-situ high temperature diffraction and transmission electron microscopy. Over the time range of interest (four hours), no evidence of Ti reaction was observed at 300°C. At 450°C. nitrogen was found to diffuse into the Ti to form a Ti(N) solid solution. Above 500°C the titanium is transformed to a second phase: however this reaction follows two different kinetic paths, depending on the annealing temperature. Below 600°C. the reaction proceeds in two stages, with the first stage consisting of Ti(N) formation, and the second stage consisting of the conversion of the Ti(N) with a transformation mechanism characteristic of short range diffusion (grain edge nucleation). Above 600°C, a simple linear transformation rate is observed.

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