• Title/Summary/Keyword: blasting effects

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Effects of obesity adult participation in boxing diets on weight loss, blood pressure and blood sugar improvements

  • Park, Noh-hwan;Kim, Kwan-kyu
    • International Journal of Advanced Culture Technology
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    • v.6 no.4
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    • pp.205-213
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    • 2018
  • This research is about effects of obesity adults participating in 12weeks of boxing diets program on weight loss, blood pressure and blood sugar improvements. The exercise program was conducted three times a week with a maximum heart rate of 50 to 65 percent for first to forth weeks and 65 to 85 percent for fifth to twelfth. The study included 59 obese people in their 20s and 50s, with a BMI of 25kg/m2 or higher, blood pressure of 140/90mmHg, and high blood pressure and diabetes patients of 125 mg/dl per fasting blood sugar. The following results were obtained by observing the results before and after the boxing exercise program. High blood pressure, diabetes, high blood pressure + diabetes after 12 weeks showed significant weight, BMI and body fat reduction, as well as significant decrease in blood pressure and fasting blood sugar. Consequently, through this study, obese adults can lower their weight, blood pressure, and blasting fasting blood sugar through a 12-week high-strength boxing exercise program and it is believed to help improve and prevent obesity, cardiovascular disease and metabolic diseases.

Investigation on the propagation mechanism of explosion stress wave in underground mining

  • Wang, Jiachen;Liu, Fei;Zhang, Jinwang
    • Geomechanics and Engineering
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    • v.17 no.3
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    • pp.295-305
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    • 2019
  • The bedding plane has a significant influence on the effect of blasting fragmentation and the overall performance of underground mining. This paper explores the effects of fragmentation of the bedding plane and different angles by using the numerical analysis. ANSYS/LS-DYNA code was used for the implementation of the models. The models include a dynamic compressive and tensile failure which is applied to simulate the fractures generated by the explosion. Firstly, the cracks propagation with the non-bedding plane in the coal with two boreholes detonated simultaneously is calculated and the particle velocity and maximum principal stress at different points from the borehole are also discussed. Secondly, different delay times between the two boreholes are calculated to explore its effects on the propagation of the fractures. The results indicate that the coal around the right borehole is broken more fully and the range of the cracks propagation expanded with the delay time increases. The peak particle velocity decreases first and then increases with the distance from the right borehole increasing. Thirdly, different angles between the bedding plane and the centerline of the two boreholes and the transmission coefficient of stress wave at a bedding plane are considered. The results indicated that with the angles increase, the number of the fractures decreases while the transmission coefficient increases.

A Study on Effects of the Artificial Structures by the Blast Pressure Simulation (폭풍압 시뮬레이션에 의한 지형지물의 영향에 관한 연구)

  • Kang, Dae-Woo;Lee, Sin;Jung, Byung-Ho;Sim, Dong-Soo
    • Explosives and Blasting
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    • v.28 no.2
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    • pp.17-27
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    • 2010
  • With the development of modern society, there have been great technical advances, and the meaning, shape, and type of preservation objects have also become diverse. However, the legislation of executives established in 1961 has nt yet been revised realistically. Thatses administrative problems related to the usge and storage of explosives. In this study, the cases of civilian's question and thought that had been submitted to the government agency were surveyed. In order to analyze the effects of preservation object, ENPro3.1, which is a simulation program to analyze the sound pressure, was used to estimate the blast pressure when a magazine containing preservation objects exploded. With the damage due to the blast pressure, the problem with the safe distance depending on the preservation object levels was investigated. From the investigation, the blast pressures in the two cases with the artificial structures at the real distance 309 m and without the artificial structures at the legitimate standard space distance 440 m, were found to be 123 dB(L) and 138 dB(L), respectively. That means the influence of blast pressure in shorter distance with artificial structures is 15 dB(L) lower than longer distance without them. Therefore, it is recommended to apply the preservation distance based on the engineering analysis with a consideration of surrounding environment.

A Case Study on the Design of Railway Tunnel through section for under OO temple (OO 사찰 하부 터널통과 설계 사례)

  • Kim, Shin;Lee, Sung-Ki;Seo, Hyoung-Chul;Kwag, Jung-Yeol;Cho, Bong-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.208-218
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    • 2006
  • It is very important to evaluate predictable problems diversely such as stability of a tunnel and structures when tunnel is inevitably constructed in the area where is adjacent to a structure and low overburden. Double electrified railway design on the third section of Donghae-Nambu line studied in this paper has some problems mentioned above. So more careful works are required before construction. In this study, ground surrounding is composed of faults, fault zone and set back about 13m from a Buddhist temple located on the upper part of the tunnel. From these conditions, this case study presents proper methods considering ground condition, effects of blasting and civil petitions. It is tried to make the tunnel and Buddhist temple stable by analytical technique and analysis of existing cases. And design considering stability of tunnel and adjacent structure during operation is carried out as well. Especially, environmentally friendly railway tunnel which is appropriate to the local condition and surroundings is designed by minimizing noise and vibration that is able to occur during construction and train service. From now on, this study is helpful to better design in the case of tunnel design which has to consider civil petition.

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A study on Measurement of Blast-Induced Ground Vibrations in Urban Areas (도심지(都心地) 발파(發破)에서의 지반진동(地盤振動) 측정(測定)에 관(關)한 연구(硏究))

  • Kim, Woong-Soo;Lee, Kyoung-Woon;Lim, Han-Uk;Suh, Baek-Soo
    • Journal of Industrial Technology
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    • v.3
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    • pp.17-26
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    • 1983
  • The blast vibrations were measured from 10 places through Seoul subway area to study their effects on the structures and to establish the safe blasting limits. For purpose of the present study, particle velocity only was recorded and analyzed, because it correlated most directly with damage. The results are as follows: (1) The proagation equation, $V=K(D/W^{1/3})^{-n}$ was obtained. Typical values could be found for n range from 1.7 to 1.5 and for k range from 48 to 138. (2) From the relationship between schmidt hammer rebound hardness and uniaxial compressive strength, $Sc=0.514{\times}(S.H)^{0.23}$, the compressive strength at any area can be assumed. (3) The use of AN-FO and other explosives with low detonation pressure may reduce vibration levels generated.

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AN EXPERIMENTAL STUDY ON THE BOND STRENGTH OF ETCHED CAST RESTORATION USING DIFFERENT METAL SURFACE TREATMENTS (수지접합 수복물용 합금의 피착면처리에 따른 결합력에 관한 실험적 연구)

  • Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.29 no.1
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    • pp.13-22
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    • 1991
  • This study investigated the effects of surface treatment on the tensile bond strength of resinbonded prosthesis. The Rexillium III specimens were treated with $50{\mu}m\;Al_2O_3$ blasting. Type IV gold alloy specimens were treated with $400^{\circ}C$ heating and tin plating method. All specimens were bonded with MBAS composite resin cement and followed by immersion test into the $37^{\circ}C$ water bath for 7 days. The specimens were debonded in tension with an Instron machine and observed with SEM. The modes of failure were recorded also. The following conclusions were obtained : 1. The tensile bond strength decreased in following order. $50{\mu}m\;Al_2O_3$ basted Resillium III group, Type IV gold alloy group treated with $400^{\circ}C$ heat and tin plating type IV gold alloy group, and statistical significant differences were observed(p<0.05). 2. The tensile bond strength decreased in all groups after 7 days immersion test, but statistical significant differences were observed in Rexillium III specimens only. 3. The sharp and irregular surface were observed in Rexillium III, but $400^{\circ}C$ heat treated and tin plated groups had round and broad surface in SEM. 4. The models of bond failure were cohesive-adhesive failure mainly.

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A new bridge-vehicle system part II: Parametric study

  • Chan, Tommy H.T.;Yu, Ling;Yung, T.H.;Chan, Jeffrey H.F.
    • Structural Engineering and Mechanics
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    • v.15 no.1
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    • pp.21-38
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    • 2003
  • The formulation of a new bridge-vehicle system using shell with eccentric beam elements has been introduced in a companion paper (Part I). The new system takes into account of the contribution of the twisting and pitching modes of vehicles to the bridge responses. It can also be used to study the dynamic transverse load distribution of a bridge. This paper presents a parametric study on the impact induced by one vehicle or multi-vehicle running across a bridge using the proposed model. Several parameters were considered as variables including the mass ratio, the speed parameter, the frequency ratio and the axle spacing parameter to investigate their effects on the impact factor. A total number of 189 cases were carried out in this parametric study. Within the realistic range of vehicle considered, the maximum impact factors could be 2.24, 1.78 and 1.49 for bridges with spans 10 m, 20 m and 30 m respectively.

A Review on the Effects of Earthborne Vibrations and the Mitigation Measures

  • Nam, Boo Hyun;Kim, Jinyoung;An, Jinwoo;Kim, Bumjoo
    • International Journal of Railway
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    • v.6 no.3
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    • pp.95-106
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    • 2013
  • Earthborne vibrations are induced by construction operation such as pile driving, roadbed compaction, and blasting and also by transit activities such as truck and trains. The earthborne vibration creates the stress waves traveling outward from the source and can structurally damage nearby buildings and structures in the forms of direct damage to structure and damage due to dynamic settlement. The wave propagation characteristics depends on impact or vibration energy, distance from the source, and soil characteristics. The aim of this paper is to provide a comprehensive review on the mechanistic of earthborne vibration and the current practice of vibration control and mitigation measures. The paper describes the state of knowledge in the areas of: (1) mechanics of earthborne vibration, (2) damage mechanism by earthborne vibration, (3) calculation, prediction of ground vibration, (4) the criteria of vibration limits, (5) vibration mitigation measures and their performance, and (6) the current practice of vibration control and mitigation measures.

The Application of the Medified Distinct Element Method to Wave Propagation in Structures with Discontinuous Faces (수정개별요소법에 의한 불연속 구조체의 파전달 거동 해석)

  • 김문겸;오금호;김우진
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.04a
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    • pp.232-239
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    • 1997
  • The phenomenology of shock loading effects in brittle mass has been of interest to researchers and engineers. The shock loading as blasting causes strong stress waves in the structures. Discontinuous faces due to shock waves interrupt the tensile stress wave propagation and reflect the stress wave propagation. To predict the fracturing behavior of brittle mass, it is required for the numerical method that can analyze the colliding and slipping behavior of discontinuous faces and the wave propagation in the mass, simultaneously In this study, the wave propagation in the brittle materials is analyzed using the modified distinct element method to be able to predict the behavior of discontinuous structures. The behavior of an unsupported bar subjected to loading at the end is analyzed to verify the rigid body motion of a bar and the relative displacement in the bar. The colliding behavior of two bars is analyzed to investigate the propagation of stress waves in the bar. The fracturing behavior of a bar due to impact loading is analyzed to investigate the propagation of stress waves in the bar with and without the discontinuous faces. The applicability of the modified distinct element method to the wave propagation problems is investigated.

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A multi-criteria decision-making process for selecting decontamination methods for radioactively contaminated metal components

  • Inhye Hahm ;Daehyun Kim;Ho jin Ryu;Sungyeol Choi
    • Nuclear Engineering and Technology
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    • v.55 no.1
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    • pp.52-62
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    • 2023
  • Various decontamination technologies have been developed for removing contaminated areas in industries. Although it is important to consider parameters such as safety, cost, and time when selecting the decontamination technology, till date their comparative study is missing. Furthermore, different decontamination technologies influence the decontamination effects in different ways. Therefore, this study compares different decontamination techniques for the steam generator using a multicriteria decision-making method. A steam generator is a large device comprising both low- and very low-level waste (LLW, VLLW) and reflects the difference in weights of the standards according to the classification of the waste. For LLW and VLLW decontaminations, chemical oxidizing reduction decontamination (CORD) and decontamination grit blasting were used as the preferred techniques, respectively, considering the purpose of decontamination differs based on the initial state of waste. An expert survey revealed that safety in LLW and waste minimization in VLLW exhibited high preference. This evaluation method can be applied not only to the comparison between each process, but also to the creation of process scenarios. Therefore, determining the decontamination approach using logical decision-making methods may improve the safety and economic feasibility of each step in the decommissioning process and ensure a public acceptance.