scholarly journals Study of the influence of intermittent motion on the orientation kinematic precision of a double harmonic transmission

2020 ◽  
Vol 65 (1) ◽  
pp. 45-50
Author(s):  
Sava Ianici
Keyword(s):  
Constant Speed ◽  
Transmission Ratio ◽  
Experimental Investigations ◽  
Experimental Installation ◽  
Intermittent Motion

The paper presents a method and an experimental installation, designed by the authors, for determining the orientation kinematic precision of a double harmonic transmission (DHT). The influence of repeated stops and then continued motion on the orientation kinematic precision of the DHT was researched. The study of the orientation kinematic precision of DHT was performed by taking into account 5 torque steps of DHT, at a constant speed of the driving shaft and maintaining its same direction of rotation. Experimental investigations have shown that the instantaneous transmission ratio of the DHT does not vary significantly from its nominal value and that the orientation kinematic precision of DHT decreases with increasing transmission torque

scholarly journals Heat Transfer Enhancement from Microprocessor

2020 ◽  
Vol 8 (4S4) ◽  
pp. 174-178
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Enhancement ◽  
Thermal Performance ◽  
Hydraulic Diameter ◽  
Constant Speed ◽  
Heat Sinks ◽  
Experimental Investigations ◽  
Transfer Enhancement ◽  
Pass Through

Experiments were conducted to investigate the cooling of processor to increase the thermal performance by employing a mini channel instead of conventional heat sinks. Now a day’s aluminium fin with fans is used for cooling the processor. Constant speed of the fans is found to be not enough to remove the heat generated by the processor. The experimental investigations were carried out in the channels with the hydraulic diameter of about 1.5x10-3m for the Reynolds number varying from 80 to 1150. The water is allowed to pass through the channel by virtue of which heat is rejected from the processor. The influence of Reynolds number on heat transfer enhancement from the microprocessor is discussed in details. Comparison between heat transfer by air and by water is presented. From the experiment it is disclosed that further increase in heat transfer was observed when compared to air.

scholarly journals RESEARCH ON DOMESTICALLY PRODUCED FIRE-FIGHTING FOAM AGENTS FOR SUBSURFACE FIRE EXTINGUISHING

Fire Safety ◽  
2018 ◽  
pp. 5-14
Author(s):  
T. M. Voitovych ◽  
B. M. Gusar ◽  
V. V. Kovalyshyn ◽  
V. V. Koshelenko ◽  
O. V. Grushovinchuk
Keyword(s):  
Diesel Fuel ◽  
Petroleum Products ◽  
Fire Fighting ◽  
Experimental Investigations ◽  
Fire Simulation ◽  
Experimental Installation ◽  
Fire Extinguishing ◽  
Fuel Layer ◽  
Steel Tanks ◽  
Definition Of

This research outlines the problems of fire extinguishing in tanks, and describes a projected model of an experimental installation for the vertical tank fire simulation. The research also describes a method of extinguishing fires of oil and petroleum products in vertical steel tanks by supplying low expansion foam to the tank base directly into the fuel layer. The time of diesel fuel and gasoline fires extinguishing with the help of general and special purpose fire-fighting foam agents was calculated. Experimental investigations on definition of the fire-extinguishing efficiency of domestically producted fire-fighting foam agents by subsurface fire extinguishing of tanks were carried out.

scholarly journals Researches on biofuels gasification using the Lurgi process with homogeneous air inlet over the combustion space

2020 ◽  
Vol 180 ◽  
pp. 01011
Author(s):  
Gheorghe Lăzăroiu ◽  
Lucian Mihăescu ◽  
Gabriel Negreanu ◽  
Iulia Simion ◽  
Dana-Alexandra Ciupăgeanu
Keyword(s):  
Coal Gasification ◽  
Combustion Process ◽  
Reduction Process ◽  
Calorific Value ◽  
Experimental Investigations ◽  
Homogeneous Distribution ◽  
Experimental Installation ◽  
Air Inlet ◽  
Efficient Combustion ◽  
Fuel Rate

The experimental investigations carried out within the present research focus on a simple gasification technology dedicated to biofuels conversion according to the Lurgi procedure. Specifically, an installation with a fixed grill and a homogeneous distribution of the air inlet over the combustion space are considered. In order to provide a thorough background for the experimental research, this paper presents first the challenges related to the air distribution. If for coal gasification the difficulty of the homogeneous penetration of the air inlet within the whole combustion volume is balanced by the possibility of the direct emission of CO valorization, for biomass gasification this factor becomes fundamental. The original contribution of the technology introduced in this paper assumes an improved combustion process for Lurgi-type gas generators. The experimental installation employed has a particular design, enabling a homogeneous distribution of the air inlet over the entire combustion zone, up to the top of the embers layer. This allows achieving a maximum CO2 content in the flue gas flux, effectively reducing it inside the embers bed. The high calorific value of biofuels used favors developing an efficient combustion process, occurring at high temperatures. Thus, the reduction process of the CO2 is self-controlled. The experimental installation operates at a slow fuel rate, with discontinued supply and precise airflow control. The quality of the gas obtained is evaluated based on the resulting open flame, analyzing its composition.

How to speed up to be in time: Action-judgment dissociations in children and adults

2004 ◽  
Vol 63 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Friedrich Wilkening ◽  
Claudia Martin
Keyword(s):  
Rating Scale ◽  
Constant Speed ◽  
Linear Condition ◽  
Speed Up ◽  
Nonlinear Condition ◽  
Speed Change ◽  
Catch Up ◽  
Normative Rule ◽  
Judgment Condition ◽  
Time Linear

Children 6 and 10 years of age and adults were asked how fast a toy car had to be to catch up with another car, the latter moving with a constant speed throughout. The speed change was required either after half of the time (linear condition) or half of the distance (nonlinear condition), and responses were given either on a rating scale (judgment condition) or by actually producing the motion (action condition). In the linear condition, the data patterns for both judgments and actions were in accordance with the normative rule at all ages. This was not true for the nonlinear condition, where children’s and adults’ judgment and also children’s action patterns were linear, and only adults’ action patterns were in line with the nonlinearity principle. Discussing the reasons for the misconceptions and for the action-judgment dissociations, a claim is made for a new view on the development of children’s concepts of time and speed.

Experimental investigations of the use of cartilage in tympanic membrane reconstruction

2000 ◽  
Vol 21 (3) ◽  
pp. 322-328 ◽  
Author(s):  
T ZAHNERT ◽  
K HUTTENBRINK ◽  
D MURBE ◽  
M BORNITZ
Keyword(s):  
Tympanic Membrane ◽  
Experimental Investigations

EXPERIMENTAL INVESTIGATIONS OF THE QUANTUM PHOTOVOLTAIC EFFECT IN InAs-GaSb SEMICONDUCTOR SUPERLATTICES

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-183-C5-186
Author(s):  
J. BLEUSE ◽  
P. VOISIN ◽  
M. VOOS ◽  
L. L. CHANG ◽  
L. ESAKI
Keyword(s):  
Photovoltaic Effect ◽  
Experimental Investigations ◽  
Semiconductor Superlattices

Evaluation of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings by the multi-frequency radio wave method of a slow surface electromagnetic waves

2020 ◽  
pp. 51-58
Author(s):  
Aleksandr I. Kazmin ◽  
Pavel A. Fedjunin
Keyword(s):  
Radio Wave ◽  
Noise Level ◽  
Electromagnetic Waves ◽  
Dielectric Materials ◽  
Geometric Parameters ◽  
Experimental Investigations ◽  
Wave Method ◽  
Dielectric Coatings ◽  
Surface Electromagnetic Waves ◽  
Multilayer Dielectric

One of the most important diagnostic problems multilayer dielectric materials and coatings is the development of methods for quantitative interpretation of the checkout results their electrophysical and geometric parameters. The results of a study of the potential informativeness of the multi-frequency radio wave method of surface electromagnetic waves during reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings are presented. The simulation model is presented that makes it possible to evaluate of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings. The model takes into account the values of the electrophysical and geometric parameters of the coating, the noise level in the measurement data and the measurement bandwidth. The results of simulation and experimental investigations of reconstruction of the structure of relative permittivitties and thicknesses of single-layer and double-layer dielectric coatings with different thicknesses, with different values of the standard deviation (RMS) of the noise level in the measured attenuation coefficients of the surface slow electromagnetic wave are presented. Coatings based on the following materials were investigated: polymethyl methacrylate, F-4D PTFE, RO3010. The accuracy of reconstruction of the electrophysical parameters of the layers decreases with an increase in the number of evaluated parameters and an increase in the noise level. The accuracy of the estimates of the electrophysical parameters of the layers also decreases with a decrease in their relative permittivity and thickness. The results of experimental studies confirm the adequacy of the developed simulation model. The presented model allows for a specific measuring complex that implements the multi-frequency radio wave method of surface electromagnetic waves, to quantify the potential possibilities for the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric materials and coatings. Experimental investigations and simulation results of a multilayer dielectric coating demonstrated the theoretical capabilities gained relative error permittivity and thickness of the individual layers with relative error not greater than 10 %, with a measurement bandwidth of 1 GHz and RMS of noise level 0,003–0,004.

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