Approximate estimation of the critical diameter in Koenen tests

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Thomas M. Klapötke ◽  
Sabrina Wahler
Keyword(s):  
Critical Diameter ◽  
Orifice Diameter ◽  
Simple Correlation ◽  
Detonation Parameters ◽  
Approximate Estimation ◽  
Steel Sleeve

Abstract A simple correlation between computed detonation parameters and the critical diameter obtained using the Koenen (steel-sleeve) test is reported. This correlation is not meant to replace a proper Koenen test, but rather, to act as an aid to help to know which orifice diameter to start testing with.

scholarly journals Modyfikowanie parametrów detonacyjnych indywidualnych materiałów wybuchowych

2019 ◽  
pp. 89-101 ◽  
Author(s):  
Andrzej Maranda ◽  
Dominika Górniewicz ◽  
Józef Paszula ◽  
Paweł Jóźwik
Keyword(s):  
Detonation Velocity ◽  
Critical Diameter ◽  
Explosive Mixture ◽  
Review Of Literature ◽  
Glass Microspheres ◽  
Detonation Parameters ◽  
Inertial Component ◽  
Thermochemical Parameters ◽  
The Impact

Individual explosives such as hexogen, octogen or TNT can be characterized by determining their thermochemical and detonation parameters. Some of these parameters can be modified by changing the diameter of the charge, type of confined or density. However, a much greater possibility of their change can be obtained by forming mixtures with various additives. The paper presents the results review of literature data regarding the impact of various additives on the detonation and thermochemical parameters of individual explosives and of research on selected detonation parameters of hexogen and octogen compositions with glass microspheres and microballoons made of plastic. Measured parameters were: critical diameter and layer as well as detonation velocity. An increase in the critical diameter and layer was observed as well as a decrease in the detonation velocity along with th increase in the content of the inertial component in the explosive mixture.

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

Pengaruh Bimbingan Kelompok Terhadap Perilaku Asertif pada Siswa

2018 ◽  
Vol 6 (4) ◽  
pp. 427-446
Author(s):  
Rina Nurviani ◽  
Lilis Satriah
Keyword(s):  
Research Method ◽  
Simple Correlation ◽  
Large Influence ◽  
Assertive Behavior ◽  
The Mind ◽  
Group Guidance

Assertive behavior holds important guidelines for the formation of a person's personality can be improved in group guidance, because in group guidance can be utilized the influence of a person or some individual against other members. This study aims to determine (1) the large influence of group guidance on assertive behavior in the expression of the mind, (2) large influence group guidance on assertive behavior in the expression of feeling, and (3) large influence group guidance on assertive behavior in the expression of mind to students. The research method used in this research is a simple correlation research method. The result of calculation obtained by value of porsentase influence group guidance to assertive behavior in expression of mind equal to 2,5%, in expression of feeling of porsentasenya equal to 4,4%, whereas in expression action only equal to 0,1%. So it can be concluded that group guidance has little effect on assertive behavior in the expression of thoughts, feelings, and actions. The overall influence of group guidance on assertive behavior is only 2.5%.   Perilaku asertif memegang pedoman penting bagi pembentukan kepribadian seseorang dapat ditingkatkan dalam bimbingan kelompok, karena dalam bimbingan kelompok dapat dimanfaatkan pengaruh-pengaruh seseorang atau beberapa individu terhadap anggota lainnya. Penelitian ini bertujuan untuk mengetahui (1) besar pengaruh bimbingan kelompok terhadap perilaku asertif dalam ekspresi pikiran, (2) besar pengaruh bimbingan kelompok terhadap perilaku asertif dalam ekspresi perasaan, dan (3) besar pengaruh bimbingan kelompok terhadap perilaku asertif dalam ekspresi pikiran pada siswa. Metode penelitian yang digunakan dalam penelitian ini yaitu metode penelitian korelasi sederhana. Hasil perhitungan diperoleh nilai porsentase pengaruh bimbingan kelompok terhadap perilaku asertif dalam ekspresi pikiran sebesar 2,5%, dalam ekspresi perasaan porsentasenya sebesar 4,4%, sedangkan dalam ekspresi tindakan hanya sebesar 0,1%. Sehingga dapat disimpulkan bahwa bimbingan kelompok berpengaruh kecil sekali terhadap perilaku asertif dalam ekspresi pikiran, perasaan, dan tindakan. Yang secara keseluruhannya pengaruh bimbingan kelompok terhadap perilaku asertif hanya sebesar 2,5%.

Work Stress and Organisational Citizenship Behaviours (OCBs) in Call Centers Employees

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Sunita ◽  
Urvashi Singh ◽  
Shalini Singh ◽  
Rajnee Sharma
Keyword(s):  
Negative Impact ◽  
Call Centers ◽  
Negative Relationship ◽  
Married Couples ◽  
Call Centre ◽  
Simple Correlation ◽  
Nuclear Families ◽  
Set Up ◽  
Stress At Work ◽  
The Relationship

The present study was conducted to examine the relationship between organisational stress and organisational citizenship behaviours (OCBs) in employees of call centers. The study also further explored as how stress at work set-up has negative impact on OCBs. A sample of 250 employees working in call centre of Gurgaon belonging to an age group of 25-30 years were selected on availability basis. All were working married couples living in nuclear families. Job stress survey (Spielberger & Vagg, 1999) and Organisational Citizenship Behaviour (Bateman & Organ, 1983) were administered. Data was analysed by using simple correlation and multiple regression. Results showed the negative relationship between organisational stress and OCBs. Results of regression analysis also exhibited the negative impact of stress on OCBs. The implications for the employees are discussed.

Tribology of rail bogie

2018 ◽  
Vol 77 (4) ◽  
pp. 230-240
Author(s):  
D. P. Markov
Keyword(s):  
Contact Fatigue ◽  
Basic Element ◽  
Difficult Problem ◽  
Railway Track ◽  
Rolling Stock ◽  
Kinematic Parameters ◽  
Approximate Estimation ◽  
Railway Bogie ◽  
Classical Calculation

Railway bogie is the basic element that determines the force, kinematic, power and other parameters of the rolling stock, and its movement in the railway track has not been studied enough. Classical calculation of the kinematic and dynamic parameters of the bogie's motion with the determination of the position of its center of rotation, the instantaneous axes of rotation of wheelsets, the magnitudes and directions of all forces present a difficult problem even in quasi-static theory. The paper shows a simplified method that allows one to explain, within the limits of one article, the main kinematic and force parameters of the bogie movement (installation angles, clearance between the wheel flanges and side surfaces of the rails), wear and contact damage to the wheels and rails. Tribology of the railway bogie is an important part of transport tribology, the foundation of the theory of wheel-rail tribosystem, without which it is impossible to understand the mechanisms of catastrophic wear, derailments, contact fatigue, cohesion of wheels and rails. In the article basic questions are considered, without which it is impossible to analyze the movement of the bogie: physical foundations of wheel movement along the rail, types of relative motion of contacting bodies, tribological characteristics linking the force and kinematic parameters of the bogie. Kinematics and dynamics of a two-wheeled bogie-rail bicycle are analyzed instead of a single wheel and a wheelset, which makes it clearer and easier to explain how and what forces act on the bogie and how they affect on its position in the rail track. To calculate the motion parameters of a four-wheeled bogie, it is represented as two two-wheeled, moving each on its own rail. Connections between them are replaced by moments with respect to the point of contact between the flange of the guide wheel and the rail. This approach made it possible to give an approximate estimation of the main kinematic and force parameters of the motion of an ideal bogie (without axes skewing) in curves, to understand how the corners of the bogie installation and the gaps between the flanges of the wheels and rails vary when moving with different speeds, how wear and contact injuries arise and to give recommendations for their assessment and elimination.

Free Level Effect on the Impeller Power Input in Baffled Tanks

1995 ◽  
Vol 60 (8) ◽  
pp. 1274-1280 ◽  
Author(s):  
Kamil Wichterle
Keyword(s):  
Reynolds Number ◽  
Power Input ◽  
Dimensionless Number ◽  
Simple Correlation ◽  
Mixture Density ◽  
Surface Aeration ◽  
Free Level ◽  
High Reynolds ◽  
Level Effect ◽  
Turbine Impeller

Analysis of extended data on turbine impeller power input in geometrically similar agitated baffled tanks shows that the power number Po is a function of Reynolds number Po = Po*(Re) until the emergence of surface aeration. Though it is usually anticipated that Po* = const in high Reynolds number region, some, whatever weak, function should be taken into consideration in more detailed analysis of the power data even here. In practice, disturbances of level and gas captured in the impeller region play also a significant role, namely in smaller tanks at higher impeller speeds. Decrease of power input can be explained by decrease of gas-liquid mixture density, or in other words by increase of efficient gas holdup eE just in the impeller region. The value eE defined by the relation Po = Po*(Re)/(1 + eE) was determined from the available data. Like other effects of the surface aeration it depends mainly on the dimensionless number Nc = (We Fr)1/4. A simple correlation eE (Nc) is suggested as a correction factor for prediction of impeller power in presence of gas capture.

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