The Determination of Low Consumption Repairable Air Materiel Consumption Quota

2014 ◽  
Vol 644-650 ◽  
pp. 4840-4843
Author(s):  
Ya Qun He ◽  
Ji Jun Li ◽  
Tao Wang ◽  
Sheng Li Hou
Keyword(s):  
Air Force ◽  
Calculation Model ◽  
Material Consumption ◽  
Repairable Parts ◽  
Low Consumption

Aiming the problem of low consumption air materiel repairable parts consumption quota, the paper creates a calculation model, gives the methods and processes solving the model, and explain the solving process with examples specifically, for the development of air material consumption quota provides an effective approach for air force air materiel system.

Quantification the Effect of the Thickness of Thin Films on their Elastic Parameters

2011 ◽  
Vol 324 ◽  
pp. 93-96 ◽  
Author(s):  
Amel Gacem ◽  
A. Doghmane ◽  
Z. Hadjoub
Keyword(s):  
Thin Films ◽  
Elasticity Modulus ◽  
Calculation Model ◽  
Thickness Variation ◽  
Acoustic Signatures ◽  
Context Modelling ◽  
Universal Relationship ◽  
Film Substrate ◽  
Material Interaction

The determination of the characteristics and properties of thin films deposited on substrates is necessary in any device application in various fields. Adequate mechanical properties are highly required for the majority of surface waves and semiconductor devices. In this context, modelling the ultrasonic-material interaction, we present results of simulation curves of acoustic signatures for multiple thin film/substrate combinations. The results obtained on several structures (Al, SiO2, ZnO, Cu, AlN, SiC and Cr)/(Al2O3, Si, Cu or Quartz) showed a velocity dispersion of the Rayleigh wave as a function of layer thickness. The development of a theoretical calculation model based on the acoustic behaviour of these structures has enabled us to quantify the dispersive evolution (positive and negative) density. Thus, we have established a universal relationship describing the density-thickness variation. In addition, networks of dispersion curves, representing the evolution of elasticity modulus (Young and shear), were determined. These charts can be used to extract the influence of thickness of layers on the variation of elastic constants

Analysis of the Stresses of the Wall of a Steel Water Tower

2018 ◽  
Vol 931 ◽  
pp. 352-357
Author(s):  
Sergey V. Skachkov ◽  
Sergei V. Shchutsky
Keyword(s):  
Finite Element ◽  
Local Stability ◽  
Calculation Model ◽  
Cylindrical Vessel ◽  
Conical Part ◽  
Element Calculation ◽  
Sheet Structure ◽  
Junction Points ◽  
Conical Bottom

We consider the calculation of the wall of a water tower in the form of a welded sheet structure, structurally consisting of a cylindrical vessel with a conical bottom and a roof and a cylindrical support. The creation of the finite element calculation model and determination of the stresses in the tower elements taking into account various features of design, installation and operation of the structure are performed. The questions of local stability of the wall in the joints of cylindrical and conical parts are considered. The necessity of arranging ribs in the conical part along the meridional directions and in the junction points - ring ribs is substantiated.

National Mapping’s Astro-Geodetic Complex

1973 ◽  
Vol 2 (4) ◽  
pp. 203-206
Author(s):  
J. McK. Luck ◽  
M. J. Miller ◽  
P. J. Morgan
Keyword(s):  
Air Force ◽  
Continental Drift ◽  
Direct Determination ◽  
Lunar Laser Ranging ◽  
Plate Movement ◽  
Cambridge Research ◽  
Lunar Laser ◽  
Lunar Ephemeris

The Division of National Mapping has received, on long term loan from NASA and in co-operation with the Smithsonian Astrophysical Observatory, a Lunar Laser Ranging instrument consisting of a gigawatt pulsed ruby laser, a 150 cm aspheric Ritchey-Chretien telescope, and associated electronic equipment. The instrument was formerly operated by the Air Force Cambridge Research Laboratories at Mount Lemmon in Arizona. Its principal use by National Mapping will be direct determination of the distance between the telescope and any of the three retro-reflector arrays placed on the Moon at Hadley’s Rille, Fra Mauro and Mare Tranquillitatis by Apollo astronauts. Full scale operation in conjunction with similar instruments well separated in latitude and longitude, in particular at Mount McDonald in Texas and Mount Haleakala in Hawaii, will permit determination of Earth rotation and polar motion, lunar ephemeris and libration, and tectonic plate movement or continental drift, which justifies its use in a geodetic environment.

Modelling and testing of a granular insulating material

2017 ◽  
Vol 42 (1) ◽  
pp. 6-15 ◽  
Author(s):  
Bożena Orlik-Kożdoń ◽  
Artur Nowoświat
Keyword(s):  
Thermal Conductivity ◽  
Granular Medium ◽  
Geometrical Model ◽  
Calculation Model ◽  
Elastic Plates ◽  
University Of Technology ◽  
Building Component ◽  
Definition Of ◽  
Insulation Plate

In the following article, the Authors present the results of initial researches into a building component needed for thermal insulation. The building component is a elastic insulation plate made from recycling materials. The solution is protected by industry patter Elastyczna pyta izolacyjna No 23 621 for Silesian University of Technology Gliwice. The paper presents the determination method of effective thermal conductivity for granular materials. It is based on the geometrical model for the determination of granular medium structure, which is based on the theory of the highest-density arrangement of equal-sized spheres. The elaborated by the Authors modeling results, obtained on the basis of an innovative description (definition) of granular medium, were addressed to the commonly applied two-component medium. To verify the correctness of the calculation model proposed by the Authors, the results were subjected to validation, basing on the thermal conductivity of elastic plates in a hot plate apparatus.

Microbiology of Delicatessen Salads

1975 ◽  
Vol 38 (3) ◽  
pp. 146-149 ◽  
Author(s):  
J. L. FOWLER ◽  
W. S. CLARK
Keyword(s):  
Air Force ◽  
The United States ◽  
Fecal Coliforms ◽  
Plate Count ◽  
Convenience Food ◽  
Total Plate Count ◽  
Health Significance ◽  
Yeasts And Molds ◽  
Geographical Locations

Prepared salads obtained from 11 convenience food manufacturers in eight geographical locations throughout the United States were examined microbiologically upon their arrival at the laboratory, stored at 2 C and examined microbiologically weekly thereafter for 5 weeks. Microbiological evaluation included determination of total plate count, coliforms, fecal coliforms, yeasts and molds, Clostridium perfringens, Staphylococcus aureus. and salmonella; pH of the salads also was measured. Microorganisms of public health significance were detected initially in few samples; during storage these microorganisms decreased in number and no longer could be detected. Yeasts and molds, and microorganisms enumerated by the total plate count consistently proliferated to extremely high numbers in shrimp, macaroni, carrot and raisin, and egg salads. Additionally, 64 prepared salads representing 13 convenience food manufacturers from 10 geographic locations were examined microbiologically for compliance with Army and Air Force Exchange Service microbiological limits. Counts in excess of the limits were found in 36 of 64 (56%) samples; violations in total plate count, coliform, and yeast and mold limits occurred in 16, 22, and 45% of the samples, respectively.

scholarly journals Predesign of a cylinder head of compression ignition engine

2019 ◽  
Vol 179 (4) ◽  
pp. 236-242
Author(s):  
Jacek NOWAKOWSKI ◽  
Krzysztof SIKORA ◽  
Szymon CYPCER
Keyword(s):  
Three Dimensional ◽  
Calculation Model ◽  
Head Model ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Timing System ◽  
Ci Engine ◽  
Design Calculations ◽  
The Given

The paper presents the initial design of the four-cylinder CI engine head and the analysis of the strength of the head with the use of FEM. The article covers: general assumptions of the designed head, analytical design calculations, three-dimensional head model and timing system components using CAD. The scope of calculations using the head calculation model includes strength calculations and determination of the amount of strain caused by the given load.

scholarly journals A Shear Strength Model for a Subsidence Backfill Body Based on Adhesion Friction Theory

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Lei Liu ◽  
Shengyou Zhang ◽  
Weidong Liu ◽  
Wei Sun ◽  
Jinxin Li
Keyword(s):  
Shear Strength ◽  
Contact Area ◽  
Adhesive Contact ◽  
Calculation Model ◽  
Strength Calculation ◽  
Strength Analysis ◽  
Actual Contact ◽  
Actual Contact Area ◽  
Friction Theory

Proper determination of the shear strength of the backfill body used to fill the subsidence is the basis for subsidence restoration and the stability analysis of materials. This study developed a shear strength calculation model for the backfill body by introducing adhesive friction theory into the shear strength analysis. A direct shear test was performed in the laboratory to verify the proposed method. Test results suggested that the shear strength calculation method based on adhesive friction theory can calculate the variation in the actual contact area between grains in the tested samples undergoing shearing and estimate the peak shear strength. The actual contact area was divided into two components, namely, adhesive contact area Arm and contact area reduction caused by shear displacement, which exhibited a maximum at Armax. The shear strength values calculated by this method were smaller than laboratory values, and their differences increased with the rock proportion in the backfill body. The differences between the theoretical and experimental values of shear strength increased with the rock grain size. The results of theoretical calculation, combined with the results of laboratory experiments, can provide support for the proper determination of shear strength of the backfill body.

Operation Modal Analysis of Pedestrian Bridge in Kroměříž

2020 ◽  
Vol 309 ◽  
pp. 281-287
Author(s):  
Kristína Bezručová ◽  
Radim Nečas ◽  
Jan Koláček
Keyword(s):  
Experimental Determination ◽  
Modal Analysis ◽  
Dynamic Test ◽  
Calculation Model ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Dynamic Tests ◽  
Pedestrian Bridge ◽  
Before And After

The publication outlines the issue of the experimental determination of modal parameters of structures using a method called operational modal analysis. The principle of the method and possible approaches of calculation of modal parameters are presented. An example of the method’s application is the determination of mode shapes and frequencies of the repaired footbridge in Kroměříž where the dynamic test was performed twice – before and after reinforcement of the structure. The results of both dynamic tests and their comparisons with the results of the calculation model performed in the ANSYS environment are presented in this article. Additionally, and integral to this article is a description of the completed footbridge reconstruction.

Radiocarbon Determination of the Carbon-Based Biomass Blending Ratio by Analysing Flue Gas Emitted from Coupled Combustion

2020 ◽  
Vol 14 (5) ◽  
pp. 608-615
Author(s):  
Ailing He ◽  
Zaifeng Li ◽  
Jinping Li ◽  
Xin Wang ◽  
Liya Zhang ◽  
...  
Keyword(s):  
Relative Error ◽  
Flue Gas ◽  
Large Scale ◽  
Experimental System ◽  
Accurate Method ◽  
Calculation Model ◽  
Determination Method ◽  
Combustion Technology ◽  
Carbon Based

The determination of carbon-based biomass blending ratio was a prerequisite for the large-scale development of the coupled combustion technology of biomass and coal. In this study, the experimental system of the radiocarbon method to detect the carbon-based biomass blending ratio by analyzing the flue gases produced during coupled combustion was built, and the calculation model of the carbon-based biomass blending ratio was proposed, and the accuracy and precision of the radiocarbon method were evaluated. The results showed that there was a good linear relationship between the 14C concentration of CO2 samples and biogenic fractions in flue gas. The application of the new calculation model improved the accuracy of the 14C determination method, and the relative error increased as the carbon-based biomass blending ratio decreased in the 14C method: the minimum relative error of the carbon-based biomass blending ratio with carbon-based assay was 15.16%,12.21%, 9.61%, 7.96% and 3.13% when considering coal and air simultaneously in AMS analysis. This further validated the 14C determination method as an accurate method for identifying the carbon-based biomass blending ratio in biomass and coal coupled combustion.

Assessment of performance reliability of transformers

Innotrans ◽  
2020 ◽  
pp. 50-53
Author(s):  
Alexander V. Okunev ◽  
◽  
Anastasia A. Ivanova ◽  
Alexander A. Philipiev ◽  
◽  
...  
Keyword(s):  
Calculation Model ◽  
Rolling Stock ◽  
Equipment Failure ◽  
Voltage Level ◽  
Traction Substation ◽  
Freight Traffic ◽  
Electric Rolling Stock ◽  
Traction Substations ◽  
Electrical Apparatus

Increase of freight traffic resulted in increased loads on traction substations and, respectively, in increase of their equipment failure risks. In the context of maintaining the required voltage level and power quality, which determine appropriate values in reliability for traction substation transformers, the article looks upon solving the problem of determination of reliability essential parameters. A proposed calculation model makes it possible to simplify the choice of electrical apparatus for uninterrupted power supply of electric rolling stock traction.

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