scholarly journals Aspects Regarding Shock Wave Mitigation Through Different Media

2015 ◽  
Vol 20 (2) ◽  
pp. 49-54
Author(s):  
Iuliana Florina Pană ◽  
Luminiţa Cristina Alil ◽  
Florin Ilie
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Random Distribution ◽  
Underwater Explosion ◽  
Second World War ◽  
World War ◽  
Biphasic Medium ◽  
Second World ◽  
Shock Wave Mitigation ◽  
Bubble Curtain

Abstract The main application of underwater detonation since the Second World War is to destroy military ships. Nowadays, a lot of studies are performed in order to discover a controlled and safe application of shock waves through different media. The paper presents the results of a research on a bubble curtain behaviour subjected to shock waves generated by an underwater TNT blast. The main objective was to analyze the mitigation solution of underwater explosion effects by means of gas bubbles. Simulations using ANSYS AUTODYN and explicit dynamics procedures were performed on a 3D model, in order to better understand the physical process of formation and propagation of a shock wave in the biphasic medium which represents the purpose of many researchers. The numerical simulations were performed taking into account the interaction between a shock wave and the bubble curtain considering a random distribution in space and bubble dimensions.

scholarly journals Research on the influence of bubble curtains on shock wave fields of the underwater explosion

2021 ◽  
Vol 62 (5) ◽  
pp. 97-105
Author(s):  
Thang Trong Dam ◽  
Viet Duc Tran ◽  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Layered Medium ◽  
Underwater Explosion ◽  
Physical Property ◽  
Propagation Rule ◽  
Incident Waves ◽  
Refracted Waves ◽  
Rock And Soil ◽  
Bubble Curtain

Shock waves, which derive from explosions, generate reflected and refracted waves when propagating in the layered medium with various acoustic stiffness. Depending on the acoustic characteristic of each layer of the medium, properties of reflected and refracted waves will increase or decrease pressures/stresses at the investigated point of medium, compared to influences of explosive shock waves (incident waves) propagated in a homogeneous and isotropic medium. Based on this mechanical physical property, scientists have studied a diversity of solutions decreasing effects of explosive shock waves in various medium such as rock and soil, water, air. However, currently there have not been any comprehensive theoretical studies on the reduction in intensity of the underwater explosion shock wave when interacting with bubble curtain. By using the analytical method and the virtual explosive method, the paper presents the propagation rule of new waves formed when the underwater explosion shock wave interacts with the bubble curtain. The results showed that the more the thickness of the bubble curtain or the higher the bubble content or the longer the distance from the explosive to the curtain, the weaker the intensity of the shock wave when passing through the curtain.

Gender and the Second World War

2017 ◽  
Author(s):  
Corinna Peniston-Bird ◽  
Emma Vickers
Keyword(s):  
Second World War ◽  
World War ◽  
Second World

Kapitalistische Krisen mit und ohne systemischer Herausforderung.

2016 ◽  
Vol 46 (185) ◽  
pp. 543-560 ◽  
Author(s):  
Ingo Schmidt
Keyword(s):  
World Market ◽  
Second World War ◽  
Deep Penetration ◽  
World War ◽  
Major Overhaul ◽  
Domestic Markets ◽  
Global Restructuring ◽  
Social Divisions ◽  
Class Power ◽  
Second World

This article draws on Marxist theories of crises, imperialism, and class formation to identify commonalities and differences between the stagnation of the 1930s and today. Its key argument is that the anti-systemic movements that existed in the 1930s and gained ground after the Second World War pushed capitalists to turn from imperialist expansion and rivalry to the deep penetration of domestic markets. By doing so they unleashed strong economic growth that allowed for social compromise without hurting profits. Yet, once labour and other social movements threatened to shift the balance of class power into their favor, capitalist counter-reform began. In its course, global restructuring, and notably the integration of Russia and China into the world market, created space for accumulation. The cause for the current stagnation is that this space has been used up. In the absence of systemic challenges capitalists have little reason to seek a major overhaul of their accumulation strategies that could help to overcome stagnation. Instead they prop up profits at the expense of the subaltern classes even if this prolongs stagnation and leads to sharper social divisions.

Zabiegi likwidujące skutki obrzezania wykonywane w Warszawie w czasie drugiej wojny światowej. Wstępna próba opisu zjawiska

2017 ◽  
pp. 437-446
Author(s):  
Maria Ciesielska
Keyword(s):  
Second World War ◽  
Tissue Preparation ◽  
World War ◽  
Medical Practitioners ◽  
Reconstruction Surgery ◽  
Repair Operation ◽  
Manual Treatment ◽  
Operating Technique ◽  
Almost All ◽  
Second World

Men’s circumcision is in many countries considered as a hygienic-cosmetic or aesthetic treatment. However, it still remains in close connection with religious rites (Judaism, Islam) and is still practiced all over the world. During the Second World War the visible effects of circumcision became an indisputable evidence of being a Jew and were often used especially by the so-called szmalcownicy (blackmailers). Fear of the possibility of discovering as non-Aryan prompted many Jews hiding on the so-called Aryan side of Warsaw to seek medical practitioners who would restore the condition as it was before the circumcision. The reconstruction surgery was called in surgical jargon “knife baptizing”. Almost all of the procedures were performed by Aryan doctors although four cases of hiding Jewish doctors participating in such procedures are known. Surgical technique consisted of the surgical formation of a new foreskin after tissue preparation and stretching it by manual treatment. The success of the repair operation depended on the patient’s cooperation with the doctor, the worst result was in children. The physicians described in the article and the operating technique are probably only a fragment of a broader activity, described meticulously by only one of the doctors – Dr. Janusz Skórski. This work is an attempt to describe the phenomenon based on the very scanty source material, but it seems to be the first such attempt for several decades.

Finnish refugee children’s experiences of Swedish refugee camps during the Second World War

2015 ◽  
Vol 12 (1) ◽  
pp. 28-37
Author(s):  
Merja Paksuniemi
Keyword(s):  
Well Being ◽  
Second World War ◽  
Refugee Children ◽  
Refugee Camps ◽  
World War ◽  
Daily Routines ◽  
Decisive Importance ◽  
Significant Difference ◽  
Camp Life ◽  
Second World

This article seeks to demonstrate how Finnish refugee children experienced living in Swedish refugee camps during the Second World War (1939–1945). The study focuses on children’s opinions and experiences reflected through adulthood. The data were collected through retrospective interviews with six adults who experienced wartime as children in Finland and were evacuated to Sweden as refugees. Five of the interviewees were female and one of them was male. The study shows, it was of decisive importance to the refugee children’s well-being to have reliable adults around them during the evacuation and at the camps. The findings demonstrate that careful planning made a significant difference to the children´s adaptations to refugee camp life. The daily routines at the camp, such as regular meals, play time and camp school, reflected life at home and helped the children to continue their lives, even under challenging circumstances.

Sign in / Sign up

Export Citation Format

Share Document