• 제목/요약/키워드: Safety grade

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Evaluation of Laser Welding Characteristics of 1.5GPa Grade Ultra High Strength Steel for Automotive Application (1.5GPa급 자동차용 고강도강의 레이저 용접부 특성평가)

  • Kim, Yong;Park, Ki-Young;Lee, Kyoung-Don;Jeong, Jun-Kou;Kim, Dong-Wha
    • Laser Solutions
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    • v.13 no.4
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    • pp.1-6
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    • 2010
  • Recently the use of ultra high strength steels (UHSS) in structural and safety component is rapidly increasing in the automotive industry. For example, 1.5GPa grade hot stamping with die-quenching of boron steel 22MnB5 could apply crash-resistant parts such as bumpers and pillars. The development of laser welding process of hot stamping steels, fundamental bead-on-plate welding and lap joint welding test were carried out using 3kW Nd:YAG laser. Local hardening & HAZ softening occurred in hot stamping steel as a result of metallurgical change caused by the welding heat input in the Nd:YAG laser welding process. The size of soft zones in the hot stamping steel was related to the welding heat input, being smaller at high speeds which generated a smaller heat input. Also in the case of lap joint design structure, same welded characteristics were shown. The HAZ softening degree was controlled to ensure the joint strength.

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A Development of the Operating Speed Estimation Model of Truck on Four-lane Rural Highway (지방부 일반국도 4차로의 화물차 주행속도 예측모형 개발)

  • Park, Min Ho;Lee, Geun Hee
    • International Journal of Highway Engineering
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    • v.16 no.5
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    • pp.173-182
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    • 2014
  • PURPOSES : The purpose of the study is to a) explore the operating speed of trucks on rural highways affected by road geometry, and thereby b) develop a predictive model for the operating speed of trucks on rural highways. METHODS : Considering that most of the existing studies have focused on cars, the current study aimed to predict the operating speed of trucks by conducting linear regression analysis on the speed data of trucks operating on the linear-curved-linear portions of the road as a single set. RESULTS : The operating speed in the plane curve portion increased with the length of the curve, and decreased with a lower vertical grade and a smaller curve radius. In the straight plane portion, the operating speed increased with a larger curve radius(upstream), and decreased with an increase in the change of the vertical grade, depending on the length of the vertical curve. CONCLUSIONS : This study developed estimation models of truck for operational speed and evaluated the degree of safety for horizontal and vertical alignments simultaneous. In order to represent whole area of the rural highway, the models should be ew-analyzed with vast data related with road alignment factor in the near future.

Contents Analysis of First Aid in Elementary, Middle and High School Textbooks (응급처치에 대한 초.중.고등학교 교과서 내용 분석)

  • Kim, Shin-Jeong;Lee, Jung-Eun;Kang, Kyung-Ah;Song, Mi-Kyung;Chang, Eun-Young;Kim, Sung-Hee
    • Child Health Nursing Research
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    • v.14 no.2
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    • pp.163-175
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    • 2008
  • Purpose: The purpose of this study was to provide basic data to develop first aid education programs for elementary, middle and high school students. Method: Forty nine textbooks adopted by first to six grade elementary schools and first to third grade of both middle and high schools were analyzed for content on first aid. Results: 1) First aid content was covered only in courses on and 2) Content on first aid was included in the categories, "General of first aid", "Rescue & moving", "Fire & Burns", "Cardiopulmonary resuscitation", "Musculoskeletal injuries", "Thermal injuries", "Wounds", "Removing foreign bodies", "Disaster & Accidents" and "Others". Categories that were not included were "Poisoning" and "Bites". The content did not follow a progression related to the level of intellectual and physical development of the students. Conclusion: These results suggest that the content on first aid should be revised to be practical and rational for the benefits of student safety.

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Selection of Working fluid for the Organic Rankine Cycle to Utilize Low-Temperature Waste Heat (저온 폐열을 이용하기 위한 유기랭킨 사이클의 작동유체 선정에 관한 연구)

  • Cho, Soo-Yong;Cho, Chong-Hyun
    • New & Renewable Energy
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    • v.10 no.4
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    • pp.36-46
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    • 2014
  • Low-grade heats are wasted even though an amount of their energy is huge. In the small and medium industrial complex sites, large amount of low-grade thermal energy generated during the manufacturing process is wasted if it is not used directly for building heating or air-conditioning. In order to utilize this waste thermal energy more efficiently, organic Rankine cycle (ORC) was adopted. The range of operating temperature of ORC was set to $60^{\circ}C$ from $30^{\circ}C$ applicable low-temperature waste heat. A study was conducted to select an appropriate organic working fluid based on these operating conditions. More than 60 working fluids were screened. Eleven working fluids were selected based on the requirements as working fluid for ORC such as environmentally friendly, safety, and good operation on the expander. Finally, six working fluids were selected by considering the operating temperature ranges. Then, a cycle analysis was conducted with these six working fluids. As a results, R-245fa and R-134a appeared as appropriate working fluids for ORC operating at low-temperature condition based on the system efficiency and the turbine output power.

Lobaplatin Combined Floxuridine/Pirarubicin-based Transcatheter Hepatic Arterial Chemoembolization for Unresectable Primary Hepatocellular Carcinoma

  • Zhao, Chang;Wang, Xu-Jie;Wang, Song;Feng, Wei-Hua;Shi, Lei;Yu, Chun-Peng
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2057-2060
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    • 2014
  • Purpose: To assess the effect and safety of lobaplatin combinated floxuridine /pirarubicin in transcatheter hepatic arterial chemoembolization(TACE) of unresectable primary liver cancer. Patients and Methods: TACE combined with the chemotherapy regimen was used to treat 34 unresectable primary liver cancer patients. DSA/MRI/CT/blood routine examinations were used to evaluate short term activity and toxicity after 4-5 weeks, the process being repeated if necessary. Results: Among the 34 cases, 1 (2.9%) showed a complete response, 21 (61.7%) a partial response, 8 (23.5%) stable disease, and 4 progressive disease, with a total effective rate of 67.6%. The content of alpha fetoprotein dropped by over 50% in 20 cases (58.8%). The rate of recovery was hepatalgia (88.2%), ascites (47.1%), appetite (55.9%), Performance Status(30.4%). The median follow-up time (MFT) was 281 days (63-558 days), and median progression-free survival was 118.5 days (95%, CI:88.8-148.2days). Adverse reactions (III-IV grade) were not common, with only 4 cases of vomiting and 2 cases of thrombocytopenia (III grade). Conclusions: Lobaplatin-based TACE is an effective and safe treatment for primary liver cancer.

Effects of Analgecine on Oxaliplatin-Induced Neurotoxicity in Patients with Gastrointestinal Cancer

  • Liu, Meng-Yan;Huang, Xin-En
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4465-4468
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    • 2015
  • Background: As the third generation of platinum-based antineoplastic agent aginst gastrointestinal cancer, oxaliplatin is considered to be associated with severe sensory neurotoxicity. Acorrding to previous studies, vitaminE, intravenous Ca/Mg and glutamine may partly reduce the incidence and severity of oxaliplatin-induced neurotoxicity. The aim of this study was to investigate the safety and efficacy of analgecine for preventing oxaliplatin-induced neurotoxicity in the patients with gastrointestinal tumors. Method: In this study, patients undergoing oxaliplatin-based chemotherapy were assigned to analgecine (experimental) group or control group. Analgecine 6ml was administered once a day for seven days from the day of oxaliplatin treatment. The National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE; version 3) was used to evaluate oxaliplatin-induced neurotoxicity. The incidence rates and grade of neurotoxicity of patients were assessed before and during (after four and eight cycles) treatment. Results: Totally, 82 patients were enrolled in this study, 42 in experimental group and 40 in control group. The occurrence of each grade neurotoxicity in the experimental group was significantly lower than that in control group. The overall occurrence rate was 31% vs 55% (P=0.043) after 4 cycles and 52% vs 75% (P=0.050) after 8 cycles. Conclusion: Analgecine appears could be effective in reducing oxaliplatin-induced neurotoxicity and be applicated for patients with gastrointestinal tumors who would be treated with oxaliplatin-based chemotherapy.

An Analysis of Teachers and Students' Difficulties in the Classes on 'Electric Circuit' Unit of Elementary School Science Curriculum (초등학교 과학과 '전기회로' 단원 수업에서 겪는 교사와 학생의 어려움 분석)

  • Lim, Ahreum;Jhun, Youngseok
    • Journal of Korean Elementary Science Education
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    • v.33 no.3
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    • pp.597-606
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    • 2014
  • The purpose of this study is to survey and analyze difficulties in teaching and learning elementary school science on the chapter titled 'electric circuit'. 28 elementary school teachers who teach 5th grade science and 73 5th grade students in elementary school were taken part in this survey. The pilot questionnaire was distributed to find out both the degree and the reason of difficulties in teaching and learning. The answers are analyzed with four areas to extract elements which make class difficult; Learner factors (L), Instruction factors (I), Curriculum & textbooks factors (C), and Environment factors (E). The results are as follows. (1) It can be seen that both students and teachers feel the highest difficulty in 7th lesson 'the direction of current', while they felt little difficulty in lesson 3 'conductor and nonconductor' and lesson 8 'the safety of electricity'. (2) The most mentioned reason of difficulties in teaching and learning was Learner factors (L). (3) Teachers felt many difficulties in experimental environment. On the other hands, students didn't think experimental failures as serious trouble. (4) Students felt many difficulties in new terms and hazy concepts or expressions. (5) Teachers felt a lot of difficulties in those from Curriculum & textbooks factors.

A study on the characteristics of corrosion-fatigue-crack propagation in the welded parts of high tensile steels under sea water (고장력강 용접부의 해수중 부식피로균열 성장특성에 관한 연구)

  • 김영식;박무창
    • Journal of Ocean Engineering and Technology
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    • v.1 no.2
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    • pp.113-122
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    • 1987
  • Ships and offshore strrctures are exposed to the corrosive surroundings, and the extablishment of the design criteria and the elucidation on the influence by this environment are requested to maintain the safety and to demonstrate the function of the structure. In this paper, the fatigue-crack-growth behavior on the compact tension specimens of quenched, tempered HT80 grade steels and RA36 high tensile steels having a single edge fatigue cracked notch respectively, were investigated under the repeated tensile stress with constant stroke in sea water for the welded parts by shielded metal arc welding. Main results obtained are summerized as follows; 1. The fatigue-crack-growth rates da/dN in sea water appeared to be greater behavior than those in air environment at the same stress intensisy factor range $\DeltaK$. 2. The correlation data of da/dN$\DeltaK$ of the two kinds of high tensile steels in sea water showed no great difference, however, the correlation data of da/dN$\DeltaK/\sigma_y$($\sigma_y$ stands for yield strength of the material) showed that the fatigue-crack-growth behavior of RA36 plate is affected by active path corrosion(APC) mechanism, while that of HT80 grade plate is mainly affected by hydrogen embrittlement mechanism.

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A Case Study on Evaluation of Educational Space in point of Universal Design - Focused on G Elementary School - (교육공간에 대한 유니버설 디자인 관점에서의 평가 사례연구(1) - G초등학교 사례를 중심으로 -)

  • Oh, Chan-Ohk;Park, Jin-Kyung
    • Korean Institute of Interior Design Journal
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    • v.21 no.5
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    • pp.12-22
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    • 2012
  • The demand on design for human diversity is increasing in the field of spatial design. This study evaluated the spatial environment of G elementary school in point of universal design. The study was carried out by the observing and measuring method and the survey method. It focused on 53 universal design related items which consisted of 5 principles; accessibility, supportiveness, adaptiveness, safety, and equality. The subjects for the survey were 170 students from first to sixth grade of G elementary school. Findings were as follows ; 1) The elementary school had many barriers for the wheelchair users to use. 2) The width of door and passage between desks, and the front and back space in classroom were not wide to pass through. Also, the students responded that the size of desk, chair, and individual locker was not enough. That is, Some items of accessibility and supportiveness were not met in classrooms. 3) Most items related to restroom were evaluated negatively by the students. 4) The dining tables were arranged monotonously in a rows. This emphasized the institutional mood. 5) Some evaluations to their school environment were significantly different by their gender and grade.

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Quantitative Analysis of Soluble Residues by Correction of Starch Content in Paperboard Grade (전분 함량 보정을 통한 판지류의 가용성 잔류물질 정량 분석)

  • Lim, Chae-Hoon;Park, Joung-Yoon;Lee, Tai-Ju;Um, Gi Jeung;Kim, Hyoung-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.6
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    • pp.78-87
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    • 2013
  • Even though the notice No. 2010-11 of the Ministry of Food and Drug Safety Administration that has been applied to analyze the content of the water soluble residue eluted from multi-layer paperboard was abolished in 2011, its application for the analysis on evaporation residue is still valid. There are very high possibilities that the noticed existing method gives the misleading result on the evaporation residue due to the water soluble starch eluted from the multi-layer paperboard. The quantitative analysis on water-soluble residue with starch content correction has been carried in the study using UV/Vis spectroscopy and HPLC. The UV/Vis spectroscopy absorbance analysis showed the large amount of the oxidized starch obtained from the aqueous residue eluted out of the multi-layer paperboard after the iodine, ${\alpha}$-amylase reaction, and starch hydrolysis. The residual content decreased by the correction through the enzyme hydrolysis.