• Title/Summary/Keyword: a confined area

Search Result 238, Processing Time 0.021 seconds

A Experimental Study on the Characteristics of Gas Explosion due to Vent Shape and Size (벤트 현상 및 크기에 따른 가스폭발 특성에 관한 실증적 연구)

  • Chae, Soo-Hyun;Jung, Soo-Il;Lee, Young-Soon
    • Journal of the Korean Society of Safety
    • /
    • v.21 no.3 s.75
    • /
    • pp.38-44
    • /
    • 2006
  • The majority of both small and large-scale experiments on gas explosion have been carried out in the explosion instruments with cylindrical tubes of a high length/diameter ratio and vessels of a high height/length ratio, focusing on investigating the interaction between propagating flame and obstacles inside the tubes or vessels. The results revealed that there is a strong interaction between the propagating flame and turbulence formed after the flame passes the obstacle. However this paper focuses on analyzing the pressure impact or profile outside the vent in vented gas explosion in a partially confined chamber by performing gas explosion experiments in a reduced-scale experimental assembly properly constructed. This study has considered eight different cases in gas explosion based on variation of three kinds of parameters such as height of vessel, shape of the vent and vent size, and reveals that the large vessel with big size circle vent is more danger to the target than others because the overpressure is spread out faraway horizontally and vertically.

Additive Process Using Femto-second Laser for Manufacturing Three-dimensional Nano/Micro-structures

  • Yang, Dong-Yol;Lim, Tae-Woo;Son, Yong;Kong, Hong-Jin;Lee, Kwang-Sup;Kim, Dong-Pyo;Park, Sang-Hu
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.8 no.4
    • /
    • pp.63-69
    • /
    • 2007
  • The two-photon stereolithography (TPS) process is a promising technique for the fabrication of real three-dimensional (3D) nano/micro-structures via application of a femto-second laser, In TPS, when a near-infrared ultrashort-pulsed laser is closely focused onto a confined volume of photocurable resin, only the local area at the center of the focus is cured. Therefore, real 3D microstructures with resolution under the diffraction limit can be fabricated through a layer-by-layer accumulative technique, This process provides opportunities to develop neo-conceptive nano/micro devices in IT/BT industries, However, a number of issues, including development of effective fabrication methods, highly sensitive and functional materials, and neo-conceptive devices using TPS, must be addressed for the realization of industrial application of TPS. In this review article, we discuss our efforts related to TPS: effective fabrication methods, diverse two-photon curable materials for high functional devices, and applications.

The Effects of Health Management Program in School Homepage on Body Composition and Blood Lipids for Obese Female College Students (학교 홈페이지를 활용한 건강관리 프로그램이 비만 여대생의 신체구성, 혈중지질에 미치는 영향)

  • Lee, Myoung-Hee;Lee, Gye-Sook;Jung, Byoung-Youl
    • Korean Journal of Human Ecology
    • /
    • v.18 no.5
    • /
    • pp.1115-1122
    • /
    • 2009
  • The purpose of this research was to measure the effects of a health management program through a school homepage on Obese Female College Students. The subjects were confined to 70 Obese Female College students from S University, located in C area. They voluntarily participated in this study. The subjects were divided into two groups by the BMI (Body Mass Index) classification: overweight or obesity program group(PG, n=35), and overweight or obesity comparative group(CG, n=35). The results obtained are summarized as follows: First, compared with the CG, there was a significant decrease for waist circumference in PG, and a significant decrease for the variables such as fat mass, weight, %fat, and BMI in PG. Second, in the investigation of blood lipids change of PG, there was a significant decrease for TC, TG and HR-rest. On the other hand, there was a significant increase for HDL-C.

Overview of the Environmental Damage, Property Loss, and Health Impairment of Residents around a US Air Force Firing Range (미국 공군 사격장 지역주민의 환경, 재산 및 건강피해)

  • Lim, Hyun-Sul
    • Journal of Environmental Health Sciences
    • /
    • v.37 no.3
    • /
    • pp.173-181
    • /
    • 2011
  • Koo-ni Firing Range in Maehyang-ri consisted of a firing range around 'Nong-sum' and a land-based firing range in the nearby coastal area. From 1951, when the US Air Force began field firing, residents of Maehyang-ri suffered damage to health, environment, life and property due to 54 years of field firing and noise. The purpose of this article is to provide an overview of the environmental damage, property loss, and health impairment by reviewing literature and related lawsuits. Environmental damage, the destruction of coastal fisheries and wetlands, would be a result of heavy metal contamination of soil. Fishing restrictions and the confiscation of farmlands caused financial hardship. Errant bombings led to the loss of life and property, including buildings and livestock. As a result, residents repeatedly sued the Republic of Korea for damages. The court decided partially in favor of the plaintiffs. Finally, Koo-ni firing range was closed down in 2005. Through the literature review, it is presumed that the noise caused hearing problems, hypertension, and mental illness. Since earlier studies were confined to a small fragment of the damage, additional studies focused on chronic health hazards are needed.

Simulation and Characteristic Measurement with Sputtering Conditions of Triode Magnetron Sputter

  • Kim, Hyun-Hoo;Lim, Kee-Joe
    • Transactions on Electrical and Electronic Materials
    • /
    • v.5 no.1
    • /
    • pp.11-14
    • /
    • 2004
  • An rf triode magnetron sputtering system is designed and installed its construction in vacuum chamber. In order to calibrate the rf triode magnetron sputtering for thin films deposition processes, the effects of different glow discharge conditions were investigated in terms of the deposition rate measurements. The basic parameters for calibrating experiment in this sputtering system are rf power input, gas pressure, plasma current, and target-to-substrate distance. Because a knowledge of the deposition rate is necessary to control film thickness and to evaluate optimal conditions which are an important consideration in preparing better thin films, the deposition rates of copper as a testing material under the various sputtering conditions are investigated. Furthermore, a triode sputtering system designed in our team is simulated by the SIMION program. As a result, it is sure that the simulation of electron trajectories in the sputtering system is confined directly above the target surface by the force of E${\times}$B field. Finally, some teats with the above 4 different sputtering conditions demonstrate that the deposition rate of rf triode magnetron sputtering is relatively higher than that of the conventional sputtering system. This means that the higher deposition rate is probably caused by a high ion density in the triode and magnetron system. The erosion area of target surface bombarded by Ar ion is sputtered widely on the whole target except on both magnet sides. Therefore, the designed rf triode magnetron sputtering is a powerful deposition system.

The Effects of Satisfaction in Personal Color Makeup Consulting on the Improvement of Personal Relations (퍼스널 컬러 메이크업 컨설팅 만족도가 대인관계 향상에 미치는 영향)

  • Hyangmi Kim;Geumran Kim
    • Fashion & Textile Research Journal
    • /
    • v.25 no.4
    • /
    • pp.490-496
    • /
    • 2023
  • This study investigated the causes and effects of personal colors consulting that are considered as a new lifestyle and revitalized personal relations, and provides an understanding of the effects personal color makeup satisfaction have on personal relations. We provide basic data for future personal color and beauty industry development and image consulting. This study surveyed male and female subjects 20-50 years of age nationwide, using a Google questionnaire. The survey lasted from May 7-26, 2023. A total of 350 questionnaires were distributed, of which 256 (130 males, 126 females) were used for the final analysis, insincere responses having been discarded. SPSS 25.0 was used fand a frequency test, exploratory factor analysis, regression analysis, and Cronbach's ? were conducted for statistical results. In addition, descriptive statistics, correlations analysis and regression analysis were conducted. As a result, as personal color makeup consulting satisfaction levels were high, it had a positive effect on confidence, positiveness, favorability, positive tendencies, and sociability, which indicates that personal relations were improved through personal color makeup. It is suggested that, as this study was confined to makeup and the subjects were mainly men, further studies should supplement this focus area of fashion, and the gender balance of study subjects should be adjusted for intensified results.

Deposition and Absorbance Characteristics of Copolymer LB Films (공중합체 고분자 LB막의 누적 및 흡광도 특성)

  • Shin, Hoon-Kyu;Choi, Yong-Sung;Lee, Burm-Jong;Chang, Jeong-Soo;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
    • /
    • 1995.07c
    • /
    • pp.1196-1198
    • /
    • 1995
  • In this paper, stability improvement of fragile LB films was attempted by monolayers at the air-water interface and crosslinking of the resulting LB films. The spreading polymers were synthesized by radical copolymerization of monoalkyl with oligoethyleneglycol methyl ether, and poly(allylamine) was employed as the subphase polymer. The monolayer properties have been studied by the surface pressure-area($\pi$-A) isotherms. Interaction between polymers and metal ions at the air-water interface and in their LB films were investigated. From the FT-IR(Reflection and Transmission) spectra, the formation of carboxylate ions and the relative orientation of the side chains could be confined. The monolayers were transferable on various substrates, and the resulting LB films were characterized by SEM and VIS-UV absorbance.

  • PDF

Paleomagnetism of the Pyongan Supergroup in the Samcheok Area (삼척지역에 분포하는 평안누층군에 대한 고지자기 연구)

  • Doh, Seong-Jae
    • Economic and Environmental Geology
    • /
    • v.28 no.6
    • /
    • pp.559-569
    • /
    • 1995
  • Paleomagnetic data have been obtained from the Upper Carboniferous-Permian Komok and Cheolam Groups which are exposed in the E-W trending Baekunsan syncline comprising the Pyongan Supergroup in eastern Korea. Two ancient components of magnetization are recovered in these groups by detailed thermal demagnetization: a post-folding component and a pre-folding component. The post-folding component $(D/I=54.0/54.6^{\circ},\;{\alpha}_{95}=14.6^{\circ})$ is a magnetic signature of the Oaebo Orogeny and appears to have been confined mainly to Cretaceous Normal Superchron. It has been rotated clockwise since this magnetization has been acquired. The pre-folding components ($D/I=341/-9.2^{\circ},\;{\alpha}_{95}=7.2^{\circ})$, paleopole at $335.7^{\circ}E$, $44.6^{\circ}N$ for Upper Carboniferous; $D/I=358.3/11.5^{\circ},\;{\alpha}_{95}=6.3^{\circ})$, paleopole at $311.9^{\circ}E$, $58.7^{\circ}N$ for Permian) pass fold and reversal tests. These paleopoles correspond only with the contemporaneous poles from the North China Block: they are removed from the poles from the South China Block. If the results of this study are corrected for the clockwise rotation deduced from the prefolding component, the enhanced agreement with North China Block can be achieved. Therefore, a first-order correlation between the Korean Peninsula and North China at least since Upper Paleozoic times is identified in this study.

  • PDF

Ethnography on Isolation Unit for Hematopoietic Stem Cell Transplantation: Focusing on Patients (조혈모세포이식 병동에 관한 문화기술지: 환자를 중심으로)

  • Kang, Young-Ah;Yi, Myung-Sun
    • Asian Oncology Nursing
    • /
    • v.9 no.1
    • /
    • pp.31-42
    • /
    • 2009
  • Purpose: The purpose of the study was to understand how patients experience everyday life in an isolation unit for hematopoietic stem cell transplantation (HSCT). Method: The data were collected from 25 patients with HSCT at the isolation unit from January to March in 2008 in one general hospital in Korea. The data were collected by participant observations and ethnographic interviews and were analyzed using ethnographic method. Results: Four themes regarding environmental area emerged: 'barrier pulling up the drawbridge', 'very strange world', 'small and restricted space tied by IV and other treatment lines', and 'loud noise in a silent space.' Three themes regarding patients emerged: 'facing fear and anxiety', 'continuation of loneliness and lethargy', and 'compromising with a very long, dull, and boring time'. These themes describe how patients with HSCT suffer from continuous physical and psychosocial problems in a confined space, while endeavoring to control these problems and to search for hope for a new life. Conclusion: The results of the study provide an in-depth understanding of the experience and culture of patients in an isolation unit for HSCT. They would be used in developing practical programs to decrease patient's culture shock including fear and anxiety at isolation unit for HSCT.

  • PDF

A DIOGRAPHIC STUDY OF THE CONDYLAR HYPERPLASIA (하악 과두 과형성증에 관한 방사선학적 연구)

  • Kim Jin-Soo;Kim Young-Jin;Choi Eui-Hwan;Kim Jae-Duk
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
    • /
    • v.25 no.2
    • /
    • pp.569-578
    • /
    • 1995
  • Condylar hyperplasia is a self-limiting condition characterized by a slowly progressing, enlargement of the mandible that results in facial asymmetry and a crossbite malocclusion. The facial asymmetry, open bite or crossbite, and radiographic evidence of an enlarged condyle confirm the diagnosis of condylar hyperplasia. The etiology of the condition is unknown. This condition usually first becomes apparent during the second decade of life, when one condyle continues to grow while the other is no longer active. Radiographically, the condyle may appear enlarged or the neck of the condyle maybe elongated or both may occur, Sometimes, however, no radiographically demonstrable condylar abnormality will be noted. Surgical correction with subcondylar osteotomy is the treatment of choice. We have observed two cases of condylar hyperplasia occurred in the left mandibular condyle of 24-year-old and 35-year-old women. We obtained that two cases were shown the followed results; 1. Clinically, both cases was unilaterally developed on C/C area, with temporomandibular disorders and pain, facial asymetry and malocclusion. 2. Radiographically, hyperplastic mass confined to the condyle. 3. Histopathologically, these cases shown increased hypertrophic region in parts, and lamellated bone with irregular trabeculae.

  • PDF