Occurrence, Distribution and Risk Assessment of PAHs in Road Dust Sediment in Daejeon Metropolitan City, South Korea

Gain Lee,Yong-Chul Jang,Kyunghoon Choi,Hongkyoung Kim,Seungmin Ji,Byeonghwan Kim,Youngsun Kwon,Ho-Sang Shin 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.2

In this study, the occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) in road dust sediment(RDS) deposited from main traffic roads as well as residential and industrial areas were examined with a total of 144 samples in seasons. Based on the results, the concentrations of PAHs were found to be higher in winter and ranged between 0.15 and 1.94 ㎎/㎏ with an average of 0.65 ㎎/㎏. The results indicate that pyrene, fluoranthene, phenanthrene, and benzo(ghi)perylene were commonly found in RDS, likely originated from vehicle exhaust emissions and fuel combustion by the diagnostic ratio study. Non-cancer risk from PAHs for humans exposed to RSD was found to be low (HI 1.2E-05). The estimated excess cancer risks by PAHs in RDS was also much less than the regulatory guideline for cancer risk (1×10<SUP>-6</SUP>). Thus, current concentrations of PAHs in RDS are expected to be pose no threat to humans under the assumed exposure scenarios with applied exposure factors. However, more extensive and long-term sample analysis for gaseous and particulate PAHs is still warranted to determine potential risks to humans and the fate in the environment, since their concentration and distribution can be influenced by micro-metrological conditions, traffic volumes, or road clean-up conditions.

간호학생의 임상수행능력, 임상실습 스트레스, 눈치

이민아, 강하늘, 이수민, 이은채, 최가인, 강문희 배재대학교 자연과학연구소 2023 自然科學論文集 Vol.34 No.1

The purpose of this study was to investigate the relationship among clinical performance, clinical practice stress, and Nunchi of nursing students. Data were collected from 42 nursing students with clinical practice experience between June 11, 2023, and July 13, 2023. The data analysis was performed using the SPSS/WIN 22.0 program, and analyzed through the Mann-Whitney U-test, Kruskall-Wallis test, and Pearson correlation coefficient. The results revealed a negative correlation between clinical performance and clinical practice stress (r = -.332, p = .032), and a positive correlation between clinical performance and situational awareness (r = .663, p < .001). Therefore, to enhance the clinical performance of nursing students, multidimensional efforts are needed to reduce clinical practice stress and improve overall satisfaction with university life and situational awareness skills. 본 연구는 간호학생의 임상수행능력, 임상실습 스트레스와 눈치를 파악하고 각 변수간의 상관관계를 확인하고자 시행되었다. 연구 대상은 임상실습 경험이 있는 간호학생 42명이며, 2023년 6월 11일부터 7월 13일까지 온라인 설문을 통해 자료를 수집하였다. 자료 분석은 SPSS/WIN 22.0프로그램을 이용하였으며 Mann-whitney U-test와 Kruskall-wallis test, Pearson correlation coefficient로 분석하였다. 연구 결과 임상수행능력은 임상실습 스트레스와 음의 상관관계(r=-.332, p=.032)가 있었으며, 눈치와는 양의 상관관계(r=.663, p<.001)가 있는 것으로 나타났다. 따라서 간호학생의 임상수행능력을 높이기 위해서는 임상실습 스트레스를 낮추고 대학생활 만족도와 눈치 역량을 높이기 위한 다각도의 노력이 필요할 것이다.

Understanding the Formation and Evolution of Dark Galaxies in a Simulated Universe

Gain Lee,Ho Seong Hwang 한국천문학회 2023 天文學會報 Vol.48 No.2

A comparative study of packaging waste management in selected countries by EPR

( Gain Lee ),( Yuree Kwon ),( Ji-hyun Jeong ),( Yeji Jang ),( Yong-chul Jang ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 심포지움 Vol.2019 No.1

Many advanced countries have established their own Extended Producer Responsibility (EPR) systems in various types of target products, recycling obligation, Producers Responsibility Organization (PRO) management and performance management. This study examines a comparative analysis for EPR systems in selected countries (South Korea, UK, Germany, France, and Belgium). This study was conducted by literature review of published reports and papers, interviews of experts, and analysis reports and data of EPR system published by OECD and EU. In these countries, producers are required to join and contribute to PRO or to fulfill their recycling obligations. PRO is obligated to recycle it with the procured funds. In the case of Germany, there are 10 PROs available throughout the country with a competition basis, while in France and Korea, there is only one PRO available for packaging materials and the local governments are obliged to collect and sort the packaging waste. This comparison analysis could help to identify the characteristics of EPR systems in selected countries and to give policy-makers a direction for effective decision-making.

모래사장 위 맨발걷기와 운동화걷기가 허리통증이 있는 노인의 통증, 장애, 운동기능, 수면만족도, 삶의 질에 미치는 효과 비교

이가인 ( Lee Gain ),전재중 ( Jeon Jaejung ),함석찬 ( Hahm Sukchan ) 대한통합의학회 2020 대한통합의학회지 Vol.8 No.4

Purpose : The purpose of this research was to investigate the effects of barefoot walking on the sandy beach on pain intensity, disability, motor function, sleep satisfaction, and quality of life in the elderly with low back pain (LBP). Methods : A single-blinded randomized controlled trial was conducted involving 32 elderly with LBP who underwent sand walking barefoot (intervention, n=16) or with sneakers (control, n = 16). Both walking methods were carried out for 30 minutes per day, three times a week for four weeks. Pain intensity and disability were assessed using the visual analog scale and Oswestry disability index, respectively. Balance and gait were evaluated using the Berg balance scale and timed up and go test, respectively. Sleep satisfaction was quantified with the Verran and Snyder-Halpern sleep scale. Finally, quality of life was assessed through the WHO quality of life scale’s abbreviated Korean version. Results : Compared with the control group, the intervention group showed significant differences in pain intensity (p=.005), disability due to LBP (p=.002), static balance ability (p=.003), dynamic balance ability (p=.002), and sleep satisfaction (p=.017). There was no significant difference in the quality of life between the two groups. Conclusion : Barefoot walking on a sandy beach is significantly effective in improving pain, disability due to LBP, balance ability, and sleep satisfaction in the elderly with LBP. Further studies with larger sample sizes and longer intervention periods must to be conducted to generalize using barefoot walking in LBP management.

국내 생활계 플라스틱 폐기물의 물질흐름분석 연구

이가인 ( Gain Lee ),권유리 ( Yuree Kwon ),장용철 ( Yong-chul Jang ) 한국폐기물자원순환학회(구 한국폐기물학회) 2020 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2020 No.-

플라스틱의 과소비로 인한 심각한 해양오염은 이미 전 세계적으로 이슈가 되고 있다. 실제 전 세계 해양에서 발견되는 폐기물의 80% 이상은 플라스틱 폐기물로 보고된 바 있다. 본 연구는 국내 플라스틱의 생산 및 소비, 처리량을 분석하여 생활계 폐기물 중 플라스틱류에 대한 물질흐름분석을 수행하는데 목적이 있다. ‘전국 폐기물 발생 및 처리현황’ 통계자료 및 문헌 검토, 재활용 시설 방문, 산업계, 공무원 및 학계 전문가와의 인터뷰를 바탕으로 플라스틱 폐기물의 발생 및 재활용 구조에 대해 분석하였다. 생활계폐기물은 종량제봉투를 통해 배출되는 플라스틱류 배출량과 재활용가능자원 중 합성수지류, 플라스틱류, 발포 수지류 배출량의 합계로 나타내었다. 본 연구결과. 2017년 기준 총 플라스틱 폐기물 7,961천 톤 중 생활계 폐기물은 2,980 천 톤(37.4%)으로 나타났으며 이중 종량제 봉투로 배출된 플라스틱류는 전체 플라스틱 폐기물의 약 18.7%를 차지하였고, 재활용품에서는 플라스틱 용기류, 필름류, 스티로폼을 합하면 약 24.7%를 차지하는 것으로 나타났다. 또한 생활계폐기물 중 재활용품으로 분리배출된 플라스틱(1,093천 톤)의 처리 방법에 따른 분석 결과, 단순 소각 처리되는 양이 1,147천톤(38%)으로 가장 높고, 고형연료 등 에너지 회수로 처리된 양이 약 1,105천톤(37%), 물질 재활용되는 양은 약 401천톤(13%), 매립되는 약은 약 328천톤(11%)로 산정되었다. 따라서 생활계 플라스틱 폐기물 중 다시 경제 영역으로 재투입되는 순환되는 비율은 13%에 불과하고, 대부분 단순 소각되거나 에너지 회수 등으로 대부분 처리되고 있다. 막대한 플라스틱 폐기물로 인한 피해를 줄이기 위해서는 물질재활용률을 늘리고 생산량을 줄이는 등의 대처를 통해 순환경제(circular economy)로 전환하기 위한 노력이 요구된다.

Fabrication of Continuously Porous t-ZrO2 Bodies Using Carbon Powder and Evaluate Their Biocompatibility

Gain Asit Kumar,Song Ho-Yeon,Lee Byong-Taek 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Microstructure control of continuously porous t-ZrO₂ bodies fabricated by multi-pass extrusion process

Gain, Asit Kumar,Lee, Byong-Taek Elsevier 2006 Materials science & engineering. properties, micro Vol.419 No.1

<P><B>Abstract</B></P><P>Continuously porous t-ZrO<SUB>2</SUB> bodies having different pore sizes were fabricated using the multi-pass extrusion process. The pore size depended on the number of extrusion passes, the extrusion ratio, and rod diameter and tube thickness. The pore size dramatically decreased as the number of extrusion passes and tube thickness increased. The pore sizes of the 2nd passed samples, which were made by a feed roll using different rod diameters and tube thickness, were about 260, 180, 150 and 90μm in diameter while the 3rd passed samples which were made with different extrusion ratios (40:1 and 61:1) were about 80 and 35μm in diameter, respectively. In the 2nd passed t-ZrO<SUB>2</SUB> bodies sintered at 1550°C, the relative density and bending strength decreased as the pore size increased. In the 3rd passed sample having a pore size of 35μm, the bending strength increased as the sintering temperature increased up to 1550°C. The maximum bending strength of the 3rd passed t-ZrO<SUB>2</SUB> body was about 297MPa.</P>

Fabrication of HAp-Coated Micro-Channelled t-ZrO2 Bodies by the Multi-Pass Extrusion Process

Kumar Gain, Asit,Lee, Byong-Taek Wiley (Blackwell Publishing) 2006 Journal of the American Ceramic Society Vol.89 No.6

Pore Size Effect on Mechanical Properties and Cell Growing Behavior of Continuously Porous t-ZrO2 Bodies

( Asit Kumar Gain ),( Ho Yeon Song ),( Byong Taek Lee ) 대한금속재료학회 ( 구 대한금속학회 ) 2006 대한금속·재료학회지 Vol.44 No.6

The continuously porous t-ZrO2 bodies with different pore sizes (90 ㎛, 150 ㎛, 180 ㎛, 260 ㎛) were fabricated using a multi-pass extrusion process. As the sintering temperature increased from 1300 to 1500℃, the bending strength value of porous t-ZrO2 bodies (260 ㎛ pore size) increased and its maximum value was about 157 MPa. On the other hand, as increasing the pore size, the relative density and bending strength values were remarkably decreased. In the porous body having 90 ㎛ pore, the bending strength was about 450 MPa. Human osteoblast like MG-63 cells and osteoclast like Raw 264.7 cells were well grown and through the continuously pores as well as on the surface of the continuously porous t-ZrO2 bodies. The osteoblast cell was grown with spindle shape, condensed circular growth and three-dimensional network type. In contrast, the osteoclast cells were appeared with pebble stone type.