• Fire Science and Engineering
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• v.24 no.6
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• pp.61-68
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• 2010

In this paper, a research and development result for the implementation of single station fixed temperature detector for residential fire prevention is described. The detector was developed for the certification in Japanese market because of very low domestic market situation. It is in the situation that there is no other regulation especially for residential detectors in Korea, Japanese case has been reviewed. Investigation of domestic legal circumstances and a comparative study for the test standard owned by KFI (Korea Institute of Fire Industry & Technology) and JFEII (Japan Fire Equipment Inspection Institute) respectively are also indicated. The detector alarms with a buzzer and an indicating LED. In the implementation ultra low power MCU(Micro Controller Unit) is applied to control the sleeping state and the monitoring state properly with low current consumption. To sense the temperature fast response thermistor is adopted in the design of fixed temperature residential detector. Automatic test function and alarm stop function are also considered in the design. The major factors which influence to current consumption are explained for the purpose of design reference. Main electronics circuit parts related to it's characteristics of the detector are described. It is explained that the measured current and experimental result of the battery discharge can be met over 10 years operation.

• Korean Journal of Oriental Medicine
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• v.18 no.3
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• pp.103-110
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• 2012

Objectives : Fire needling has been applied as the treatment for various diseases and been getting much attention from Oriental medicine due to its excellent effectiveness as the results of clinical studies have reported. However, the research findings on the safety of treatment method, materials for the Fire needling needle materials and the possibility of burn injury during the procedure are still insufficient. Methods : A thermo imaging camera was used to confirm the temperature distribution on acupuncture needle and the treatment area during the fire needling therapy. Then the degree of thermal injury was observed by H&E stain and TUNEL assay. In addition, in order to assess the safety of acupuncture materials, we conducted MTT assay using a L6 cell line. Results : The average temperature of the skin surface was observed at $47{\sim}51^{\circ}C$ after classic fire needling and $30^{\circ}C$ after warming fire needling. Warming fire needling therapy does not induce a burn on the tissue and a third degree burn was observed locally in the muscle and skin layers after classic fire needling treatment. This confirms that hwa-acupuncture therapies do not cause major burns. According to the safety assessment test result, no cytotoxicity was detected in the warming fire needling materials. This confirms the safety of the acupuncture materials Conclusions : Various research results on the biological safety of fire needling. Since fire needling therapy induces a burn locally without leaving any scar, and as other results indicate, it is considered a safe treatment method.

• Fire Science and Engineering
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• v.16 no.1
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• pp.77-83
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• 2002

The objective of this study is to propose a method to prevent the possible stress corrosion cracking of a horizontal side-wall sprinkler head deflector in the same atmosphere of ammonia gas as it regulated in the UL (Underwriters Laboratory). A corrosion test is carried out for three types of specimen according to post-forming treatment, one of which is annealing, another sand blasting and the other no treatment. The observation of the test specimens with a metal micro-scope says that the tensile residual stress is a major factor causing corrosion cracking, and that a proper heat treatment can remove or reduce the residial stress and prevent a crack from occurring even in a severe corrosive atmosphers.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.98.1-98.1
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• 2011

전 세계적으로 대표적인 대중교통으로 천연가스버스가 운행 중에 있으며, 천연가스의 저장을 위하여 대부분의 차량이 복합용기를 사용하고 있다. 또한 친환경자동차로 개발되고 있는 수소연료전지자동차도 수소 저장용으로 복합용기를 적용하여 상용화를 추진 중에 있다. 복합용기의 상용화가 증가하면서 복합용기의 안전성 확보가 가장 중요한 이슈가 되고 있다. 기체상태의 고압가스를 교통수단에 적용하기 위하여, 저장매체인 고압복합용기의 안전성 및 기술 확보를 위한 기술개발과 안전기준의 확립을 위한 기준개발이 미국, 유럽, 일본 등 다수의 국가에서 진행되고 있다. 현재 복합용기의 안전성을 확인하는 기준은 각 나라의 기준에 따라 진행되고 있으며 천연가스자동차용 저장용기 국제표준으로는 ISO 11439가 적용되고 있다. 수소연료전지자동차용 수소용기의 안전기준은 아직 확립되지 않은 상태이며, 개발된 초안으로는 국제규정으로 UN ECE R No.79 및 국제기술표준으로 ISO/TS 15869가 있다. 개발 중인 국제기준 및 국내기준에서 가장 취약한 부분이 화염시험이다. 화염시험은 자동차에 화재가 발생했을 경우 용기의 폭발을 막기 위하여 안전밸브가 정상적으로 작동하는 지를 확인하는 시험이다. 하지만 현재의 시험방법으로는 자동차에서 발생하는 국부적인 화염에 대한 안전성을 확인하기가 어려운 실정이다. 본 연구에서는 국내의 화염시험기준을 개발하기 위해 수행된 화염시험에 대한 결과와 화염시험장치를 제안하고자 한다.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.46-53
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• 2005

Existing study far fire-resistant concrete has been done already. but it is not found out how the waste tyre mixing concrete will be acted against fire. This waste tyre concrete molds under the condition of $0^{\circ}C,\;200^{\circ}C,\;400^{\circ}C,\;600^{\circ}C$ were heated in gas oven. It was worried about that they might be fractured down at about $800^{\circ}C$ so that they can not be tested. compressive strength for the test molds are made with commercially used $180kg/cm^2,\;210kg/cm^2,\;240kg/cm^2,\;270kg/cm^2$ mixing saw dust with proportion such as 0.05%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0% compressive strength at $200^{\circ}C$ was approximately 20% from the original, while approximately 30% deoreased at $400^{\circ}C$. their results are not quite different from the normal concrete condition even though they contains saw dust in it. The higher strength the concrete has, the less strength was decreased. There are almost no difference in strength under the condition of less than $400^{\circ}C$, but damage of concrete structure could be considerable large with more than $400^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.180-188
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• 1982

This study was carried out to make hardboard fire retardants and to examine the properties of the hard-board treated with them. The fire retardant treatment was achieved by surface impregnation of water soluble retardant chemicals into the forming mat with 55 percent of moisture content. followed by the hot pressing process. Ammonium monophosphate, ammonium diphosphate, sodium borate, and boric acid were used as the fire retardants. Fire retardant test was carried out by using the differential thermal analysis thermogram. The results are summarized as follows: 1. Fire retardant-treated hardboard showed higher values of the specific gravity. water absoption, and flexural strength than those of untreated hardboard. Especially, the treatment of ammonium monophosphate gave the best results in the flexural strength, and a 10 gr/$ft^2$ loading of the fire retardant compound of ammonium monophoshate, ammonium diphosphate, and sodium borate drew the best flexural strength value among the three different experimental loadings of 10, 20 and 30 gr/$ft^2$. 2. There were no definite differences in moisture content between the fire retardant-treated hardboard and the untreated hardboard. 3. The fire retardant compound of ammonium monophosphate, ammonium diphosphate, and sodium borate resulted in the best fire retardancy, and its fire retardancy was increased in proportion to the increase of loading.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.541-550
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• 2019

An emergency generator is key equipment for fire-fighting to supply power to fire-fighting facilities, which protect property and people in cases of fire accidents. A rated load test for emergency generators must be carried out by connecting an emergency load to the generator in accordance with related regulations. However, a no-load test has been performed for emergency generators in general since serious problems can occur when the main power is cut off, including the damage of customer devices and shut down of critical loads. Therefore, this paper proposes a load test method for an emergency generator using energy storage system (ESS) without the interruption of main power. The emergency power system was also modeled based on PSCAD/EMTDC software, and a 200-kW scale ESS load test device was implemented. The simulation and test results show that the load test method is useful and practical for an emergency power supply system.

• Magazine of the Korea Concrete Institute
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• v.7 no.2
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• pp.117-125
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• 1995

In this study, the damage to a concrete br~dge pier due to flre caused by the fall of an oil truck were investigated by the use of FEM and by tensile tests for reinfortements. And thtse results were analyzed and compared with the measured values. In the FEM calculations, the selected variable was the fire temperature $T_a=500-800^{\circ}C$. The fixed values were the heat transition coefficient ${\alpha}=2000W/m^2{\cdot}K$. the initial temperature of concrete $T_0=5{\circ}C$ and the fire duration t=30 minutes. As the results obtained from numerical calculations, the property darrlage zone ap,)eared to be 1.5-4.1cm and the structure damage zone appeared to be 8.7- 10.1cm from the concrete surface. And this results give values very similar to those measured, nanlelv 2-4cm and 8~10cm respectively. The results frorn tensile tests give no serious loss of the tensile strength.

• Geomechanics and Engineering
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• v.14 no.2
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• pp.107-113
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• 2018

Coal samples with different joints morphology were subjected to uniaxial compression experiments, cracks evolution was recorded by Nikon D5300 and acoustic emission (AE) energy signals were collected by AEwin Test for Express-8.0. During loading process, coal samples deformed elastically with no obvious cracks changes, then they expanded gradually along the trace of the original cracks, accompanied by the formation of secondary cracks, and eventually produced a large-scale fracture. It was more interesting that the failure mode of samples were all shear shape, whatever the original cracks morphology was. With cracks and damage evolution, AE energy radiated regularly. At the early loading stage, micro damage and small scale fracture events only induced a few AE events with less energy, while large scale fracture leaded to a number of AE events with more energy at the later stage. Based on the multifractal theory, the multifractal spectrum could explain AE energy signals frequency responses and the causes of AE events with load. Multifractal spectrum width (${\Delta}{\alpha}$), could reflect the differences between the large and small AE energy signals. And another parameter (${\Delta}f$) could reflect the relationship between the frequency of the least and greatest signals in the AE energy time series. This research is helpful for us to understand cracks evolution and AE energy signals causes.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.4
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• pp.19-25
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• 2006

Thermal transient tests were performed on the electric initiator with STS 304 bridgewire(diameter 2.3 mil) and $Zr-KCIO_4$ primary charge. Analysing the test data using fitted Wire Model shows that the thermal characteristic parameter related to primary charge is changed sharply around $300^{\circ}C$. It is determined that this phenomenon is due to endothermic reaction from phase transition of $KCIO_4$, which is a component of the primary charge.