복합식 공기청정기의 물리적 및 생물학적 입자상 물질의 제거 효과

김기연,김치년,김윤신,노영만,이철민,Kim, Ki-Youn,Kim, Chi-Nyon,Kim, Yoon-Shin,Roh, Young-Man,Lee, Cheol-Min 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.5

There was no significant difference in the CADR (Clean Air Delivery Rate) between physical aerosols, NaCl and smoke, and biological aerosols, airborne MS2 virus and P. fluorescens, which implicate that the hybrid-type of air purifier, applying the unipolar ion emission and the radiant catalytic ionization, imposed identical reduction effect on both physical aerosol and bioaerosol. Ventilation decreases the efficiency of air cleaning by unipolar ionization because high ventilation diminishes the particle concentration reduction effect. The particle removal efficiency decreases with increase in the chamber volume because of the augmented ion diffusion and higher ion wall loss rate. Particle size affects the efficiency of air ionization. The efficiency is high for particles with very small diameter because reduction of charge increases with particle size. If there is no increasing supply of ions, the efficiency of air cleaning by unipolar ionization increases with respect to initial concentration of particles because of the large space charge effect at high particle concentration and amplified electric field.

젖소 사육에서 탄소 순환 체계에 관한 고찰 연구

김기연,고한종,김치호,최은규,김종구,유영선,김현태,Kim, Ki-Youn,Ko, Han-Jong,Kim, Chi-Ho,Choi, Eun-Gyu,Kim, Joung-Ku,Ryou, Young-Sun,Kim, Hyeon-Tae 한국축산환경학회 2012 축산시설환경학회지 Vol.18 No.1

젖소를 사육하는 유우농가 마을을 대상으로 선행 국내/외 문헌자료들에 대한 고찰을 통해 탄소 유입과 배출에 따른 각 부문별 발생량 원단위에 대한 다음과 같은 결론을 도출하였다. 1. 젖소 사육과정에서 탄소 유입에 대한 발생량 원단위는 젖소의 사료 섭취에 의한 탄소 유입(${\fallingdotseq}$ 5.9 ton C/head/year), 젖소 분뇨 퇴비를 초지로 환원시 탄소 유입(${\fallingdotseq}$ 2.3 ton C/head/year), 초지가 함유하고 있는 유기탄소(${\fallingdotseq}$ 318g C/$m^2$/year), 사료작물이 함유하고 있는 유기탄소(${\fallingdotseq}$ 145 g C/$m^2$/year) 및 광합성에의한 대기 중 $CO_2$의 초지 사료작물 흡수(${\fallingdotseq}$ 17 g C/$m^2$/year)로 정리할 수 있다. 2. 젖소 사육과정에서 탄소 배출에 대한 발생량 원단위는 젖소 호흡 및 트림에 의한 대기 중으로 $CO_2$와 $CH_4$ 배출(${\fallingdotseq}$ 2,9 ton C/head/year), 젖소 분뇨내 유기탄소 분해에 의한 대기 중으로 $CO_2$와 $CH_4$ 배출(${\fallingdotseq}$ 0.4 ton C/head/year), 초지에서 대기 중으로의 $CO_2$ 배출(${\fallingdotseq}$ 440 g C/$m^2$/year), 및 초지 내 유기탄소의 지하수 용출(${\fallingdotseq}$ 0)로 정리 할 수 있다. The first objective of this study is to estimate emission coefficient of organic carbon regarding its inflow and discharge for dairy farm through reviewing domestic and foreign literature published or reported previously. Its second objective is to provide fundamental data to establish carbon cycle system related to livestock production. Based on literature review, emission coefficients by inflow of organic carbon into dairy farm were 5.9 ton C/head/year for feedstuff ingestion by milk cow, 2.3 ton C/head/year for recycling manure compost of milk cow to grassland, 318 g C/$m^2$/year for contents in grassland, 145 g C/$m^2$/year for contents in fodder crop, and 17 g C/$m^2$/year for $CO_2$ uptake by fodder crop, respectively. on the other hand, emission coefficients by discharge of organic carbon from dairy farm were 2,9 ton C/head/year for emission of $CO_2$ and $CH_4$ by respiration and burp of milk cow, 0.4 ton C/head/year for emission of $CO_2$ and $CH_4$ by decomposition of organic carbon in manure of milk cow, 440 g C/$m^2$/year for emission of $CO_2$ from grassland, and 0 for elution of organic carbon in grassland into underground water, respectively.

반복 하중이 Full veneer crown의 유지력에 미치는 영향에 관한 연구

김기연,이선형,정헌영,양재호,허성주,Kim, Ki-Youn,Lee, Sun-Hyung,Chung, Hun-Young,Yang, Jae-Ho,Heo, Seong-Joo 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.5

Dislodgement of a crown or extension bridge and the loosening of a retainer of a bridge is a serious clinical problem in fixed restoration. Generally these problems are considered to be associated with deformation of the restoration. During biting, the restoration is subjected to complex forces and deforms considerably within the limit of its elasticity. Deformation of the restoration under the occlusal force induces excessive stress in the cement film, which then leads to the cement fracture. Such a fracture may eventually cause loss of the restoration. Because most of the past retention tests for full veneer crown were done without fatigue loading, they were not exactly simulating intraoral environment. And the purpose of this study was to evaluate the effect of cyclic cantilever loading on the retentive strength of full veneer crowns depending on different type of cements and taper of prepared abutment. Steel dies with $8^{\circ}\;or\;16^{\circ}$ convergence angle were fabricated through milling and crowns with the same method. These dies and crowns were divided into 8 groups. Group 1 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 2 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 3 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 4 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 5 : $16^{\circ}$ taper die, cementation with Panavia 21, without loading Group 6 : $16^{\circ}$ taper die, cementation with Panavia 21, with loading Group 7 : $8^{\circ}$ taper die, cementation with Panavia 21 without loading Group 8 : $8^{\circ}$ taper die, cementation with Panavia 21, with loading After checking the fit of die and crown, the luting surface of dies and inner surface of crowns were air-abraded for 10 seconds. The crowns were cemented to the dies, with cements mixed according to the manufacturer's recommendations. A static load of 5kg was then applied for 10 minutes with static loading device. Twenty-four hours later, group 1, 3, 5, 7 were only thermocycled, group 2, 4, 6, 8 were subjected to cyclic loading after thermocycling. Retentive tests were performed on the Instron machine. From the finding of this study, the following conclusions were obtained 1. Panavia 21 showed significantly higher retentive strength than zinc phosphate cement for all groups (p<0.05). 2. There was a significant difference in the retentive strength between $8^{\circ}\;and\;16^{\circ}$ taper for zinc phosphate cement(p<0.05), but no significant difference for Panavia 21 (p>0.05). 3. Cyclic loading significantly decreased the retentive strength for all groups(p<0.05). 4. For zinc phosphate cement, there was 35% reduction of the retentive strength after loading in the $16^{\circ}$ taper die, 25% in the $8^{\circ}$ taper die, and for Panavia 21, 21% in the $16^{\circ}$ taper die, 18% in the $8^{\circ}$ taper die.

제언 - 축산업의 산업보건 접근 방향

김기연,Kim, Gi-Yeon 대한산업보건협회 2020 산업보건 Vol.382 No.-

공기정화기 가동에 따른 사무실 재실자들의 행동성과 입자상 오염물질의 농도 분포 관계에 관한 연구

김기연,박재범,김치년,이경종,Kim, Ki-Youn,Park, Jae-Beom,Kim, Chi-Nyon,Lee, Kyung-Jong 한국환경보건학회 2007 한국환경보건학회지 Vol.33 No.4

The reduction efficiency of air cleaner on particulate contaminants such as dust, airborne bacteria and fungi distributed in the office was relatively higher in case of office with workers than office without workers. This result would be attributed to workers' activities and physical characteristics of particulate contaminants. The air cleaner decreased a concentration of airborne bacteria more than airborne fungi, which implicates that difference of dust adsorption between airborne bacteria and fungi would affect an operation efficiency of air cleaner.

시편 제작 방법이 지르코니아 코어와 비니어링 세라믹의 미세 인장결합강도에 미치는 영향

김기연,여인성,김성훈,한중석,이재봉,양재호,Kim, Ki-Yeon,Yeo, In-Sung,Kim, Sung-Hun,Han, Jung-Suk,Lee, Jai-Bong,Yang, Jae-Ho 대한치과보철학회 2011 대한치과보철학회지 Vol.49 No.2

연구 목적: 미세 인장결합강도 측정을 위한 시편 제작 시 발생하는 스트레스가 결합강도에 어떠한 영향을 미치는 지를 알아보고자 하였다. 연구 재료 및 방법: 원통 모양의 지르코니아 블럭을 다이아몬드 디스크를 이용해 디스크 형태로 자른 후 소결하였다. 소결된 지르코니아 디스크에 소성시 수축을 고려한 적당한 크기의 틀을 제작하여 LAVA ceram (3M ESPE, Seefeld, Germany) 도재를 축성한 후 소성하였다. 먼저 그룹 1은 디스크 모양의 시편을 충분히 물을 뿌려가며 다이아몬드 디스크를 이용하여 $1{\times}1{\times}7\;mm^3$의 막대기 모양으로 저속에서 절단하였다 (n = 15). 그룹 2는 같은 방법으로 $1.2{\times}1.2{\times}7\;mm^3$로 자른 후 두꺼운 다이아몬드 디스크를 이용해 $1{\times}1{\times}7\;mm^3$로 트리밍하였다 (n = 15). 그 후 특별히 제작된 지그에 각각의 시편을 core-veneer의 접착면이 오염되지 않도록 조심히 접착한 후 미세 인장결합강도 측정기 (Instron 8848, $Instron^{(R)}$ Co., Norwood, USA)를 이용하여 미세 인장결합강도를 측정하였다. 측정이 끝난 시편은 파절면을 stereomicroscope (MZ6, Leica Microsystems GmbH, Wetzlar, Germany) 로 30배 확대 관찰하여 파절의 종류를 구분하였다. 결과: 지르코니아 코어와 비니어링 세라믹 간의 평균 미세 인장결합강도는 절단만 시행한 그룹은 $28.8{\pm}7.0\;MPa$, 절단 후 트리밍을 한 그룹은 $11.0{\pm}33\;MPa$로 절단후 트리밍을 한 시편이 유의성 있게 결합강도가 낮아진 것으로 나타났다 (P=.00). 결론: 미세 인장결합강도 측정을 위한 시편 제작 시 가능한 한 스트레스를 가하지 않고 미세 시편을 제작하는 것이 중요하다고 사료된다. The aim of this study was to investigate effect of specimen preparation method on the microtensile bond strength of veneering ceramic to zirconia core. Materials and methods: Cylindrical Lava zirconia block (3M ESPE, Seefeld, Germany) was cut into discs using a diamond disc. After sintering, the core specimens were placed in an adjustable mold and veneered with Lava ceram (3M ESPE, Seefeld, Germany). The disc shaped specimen of group 1 was cut into microbars ($1{\times}1{\times}7\;mm^3$) using a low speed diamond disc under water cooling (n = 15). The specimen of group 2 was cut into microbars ($1.2{\times}1.2{\times}7\;mm^3$) in the same way. Whereafter the microbars were trimmed ($1{\times}1{\times}7\;mm^3$) using a thick diamond disc under water cooling (n = 15). The microtensile bond strength was tested in a microtensile tester (Instron 8848, $Instron^{(R)}$ Co., Norwood, USA). Fractured microtensile specimens were analyzed under a stereomicroscope (MZ6, Leica Microsystems GmbH, Wetzlar, Germany) at magnification ${\times}30$. Results: The microtensile bond strength of group 1 ($28.8{\pm}7.0\;MPa$) was significantly higher than group 2 ($11.0{\pm}33\;MPa$) (P=.00). Conclusion: It appears advisable to avoid the trimming action, especially high strength ceramic specimens.

암환자의 요구 조사 도구 개발

김기연,최상순,박소미,송희영,허혜경,Kim, Gi-Yon,Choi, Sang-Soon,Pak, So-Mi,Song, Hee-Young,Hur, Hea-Kung 한국호스피스완화의료학회 2002 한국호스피스.완화의료학회지 Vol.5 No.2

목적 : 본 연구는 암환자의 요구를 포괄적으로 포함하면서 실용적으로 측정할 수 있는 도구를 개발하기 위해 시도되었다. 방법 : 기존의 문헌들과 함께 Wingate와 Lackey(1989)의 내용분석 결과를 근거로 정보요구, 이용가능한 자원, 신체적 요구, 정서적 요구, 영적 요고, 그리고 법적/경제적 요구의 6개 영역을 선정하였고, 각 영역에 대한 문항 내용은 암환자 대상의 요고, 조사연구들를 참고로 하여 작성한 후 간호학 교수 3인의 자문을 받아 문항의 내용을 수정, 추가 또는 삭제하면서 예비문항을 작성하였다. 이를 통해 정보요구 7문항, 이용가능한 자원 5문항, 정서 요구 4문항, 영적요구 5문항, 법적/경제적 요구 4문항, 신체적 요구 7문항의 총 32문항의 예비도구를 작성하였다. 예비 도구의 내용 타당도를 확인하기 위해 강원도 소재 대학병원의 간호사 중 평균 경력 10년 이상인 암환자를 간호하고 있거나 간호한 경험이 있는 수간호사와 책임 간호사 9명을 대상으로 실시하였고, 구성타당도와 신뢰도를 검증하기 위해서는 강원도 충정도 및 경기도 소재 종합병원에 근무하고 있는 간호사 116명을 편의표출하였다. 수집된 자료를 SPSS 10.0 WIN을 이용하여 요인분석 및 Cronbach ${\alpha}$값을 구하였다. 결과 : 1) 내용 타당도 분석 결과, 전문가 합의률이 55.4%로 낮은 '유언장 쓰는 방법을 알고싶다'는 문항이 삭제되어 31문항이 선정되었다. 2) 요인분석을 실시한 결과 신체적 요구, 정보 요구, 영적 요구, 정서 요구, 이용가능한 자원, 그리고 법적/경제적 요구의 6요인이 추출되었고 전체 설명력은 61.840%였다. 제 1요인인 신체적 요구와 제 2요인의 정보요구는 각각 25.354%와 10.903%의 설명력을 나타내어 암환자 요구의 주요 영역으로 규명되었다. 3) 도구의 신뢰도는 내적 일관성을 나타내는 Cronbach ${\alpha}$값은 .90이었다. 결론 : 본 연구에서 개발된 도구는 간호사로 하여금 암환자의 요구를 포괄적으로 사정할 수 있게 하고 궁극적으로는 암환자의 요구에 맞는 총체적이며 포괄적인 간호중재를 마련하는 근거로 활용될 것이다. Purpose : This study was designed to develop an instrument that could be used for comprehensive and effective need assessment for patients with cancer. Methods : In the first phase, a conceptual framework for the instrument was established by Wingate & Lackey (1989). In the second phase, the preliminary instrument was drawn up through a review of the literature and in consultation with three professors in Nursing. In the third phase validity and reliability of the preliminary instrument were tested as follows; 1) an expert validity test of the preliminary instrument was done by nine head nurses and charge nurses who had over ten years experience caring for patients with cancer at Wonju Christian Hospital. 2) A construct validity test and reliability test was done for the instrument by 116 staff nurses selected by convience sampling from hospitals located in Kang-Won, Kyoung-Ki, and Choong-Chung Provinces. The collected data were analyzed using SPSS 10.0 WIN program. For the factors of the instrument, factor analysis was used. The reliability of the scale was analyzed by Cronbach's alpha. Results : The results of the experts' test of validity, showed that, of 32 items, only one item had less than 55.4%. It was then deleted and a total of 31 items was selected. On the basis of the results of the factor analysis, the following six components were identified: physiological, informational, spiritual, and emotional needs, available resources, and legal/financial needs. These factors explained 61.8% of the variance. In the factor analysis, the first factor (physiological needs) and the second factor (informational needs) explained 25.4% and 10.9% of the variance respectively, which were major factors for the needs of patients with cancer in Korea. Cronbach' alpha for the scale was .90 indicating internal reliability. Conclusion : This instrument can be effectively utilized for assessment of needs of patients with cancer in Korea. Use of the needs assessment instrument developed in this study will allow nurses to develop nursing interventions that provide comprehensiveness and continuity in meeting the needs of patients with cancer.

액상 첨가제 살포 방법에 의한 밀폐형 돈사에서의 분진 저감 평가

김기연,고한종,김치년,Kim, K.Y.,Ko, Han-Jong,Kim, C.N. 한국축산환경학회 2008 축산시설환경학회지 Vol.14 No.2

본 연구는 지금까지 활용되었거나 새로이 제안된 액상 첨가제를 돈사에 살포하여 분진 농도의 경시적 변화를 관찰하여 제거 효과에 대해 객관적으로 비교 평가하기 위한 것으로 다음과 같은 결론들을 도출했다. 1. 살포 전 밀폐형 돈사내 분진 농도는 다른 연구자의 결과와 비교시 전반적으로 낮았다. 2. 온도의 경우는 살포 후 24시간까지 돈사 내부와 외부 큰 차이가 없었으나, 상대습도는 살포 후 1시간까지 증가하여 외부와 약 10% 가량의 차이를 보였다. 3. 평가대상 모든 액상 첨가제들의 살포직후 분진 평균 저감율은 살포 전 농도 대비 약 30%로 나타났다(p<0.05). 4. 살포 3시간 이후부터는 콩기름을 제외하고 다른 액상 첨가제들의 분진 농도에 대한 경시적 저감 효과가 관찰되지 않았다. 5. 평가대상 모든 액상 첨가제들 중 콩기름의 살포가 제거 효율성 및 안전성 측면 모두 돈사 분진 제어에 대해 가장 효과적인 첨가제였다. Appropriate air quality in the pig building is essential to prevent farmers' health as well as to increase pig performance. This on-site experiment was conducted to assess dust reduction efficiencies of several liquid additives with spaying method in the enclosed pig building. The mean reduction rate of total dust only after spray was approximately 30% for all the treatments compared to initial level before spraying additives, which was found to reduce the initial level of total dust significantly (p<0.05). The mean reduction rate of all the treatments at 1hr after spray was about 24% which was 6% lower than only after spray. Since 3hr after spray, however, total dust level were fluctuated variably for all the treatments besides application of the soybean oil. Based on this result, effect of soybean oil on dust reduction in the enclosed pig building was most prominent among liquid additives evaluated in terms of efficiency and duration.

서울시 일부 지하철역 내 분포하는 부유 세균 및 입자상 오염물질 평가

김기연,박재범,김치년,이경종,Kim, Ki-Youn,Park, Jae-Beom,Kim, Chi-Nyon,Lee, Kyung-Jong 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.4

In activity areas of subway workers and passengers in Seoul metropolitan subway lines 1-4, mein concentrations of airborne bacteria were relatively higher in workers' bedroom and station precinct whereas concentrations of particulate matters, $PM_{10}$ and $PM_{2.5}$, were relatively higher in platform, inside train and driver's seat as compared with other activity areas. This result indicates that little correlation between airborne bacteria and particulate matters was found, which assumed that most airborne particulate matters distributed in subway consisted of mainly inorganic dust like a metal particles. Mean concentrations of $PM_{10}$ and $PM_{2.5}$ in station precinct and platform exceeded the threshold limit value ($PM_{10}:150{\mu}g/m^3,\;PM_{2.5}:65{\mu}g/m^3$) but those in station office and ticket office were below it. The genera identified in all the activity areas of subway over 5% detection rate were Staphylococcus, Micrococcus, Bacillus and Corynebacterium, of which Staphylococcus and Micrococcus covered over 50% of total airborne bacteria and were considered as predominant genera distributed in subway.

여성과 가을, 그리고 아름다운 피부

김기연,Kim, Gi-Yeon 한국건강관리협회 1985 건강소식 Vol.9 No.9

여심의 피부는 가을바람에 피어오른다 낙엽 내음을 싣고 오는 가을바람에 가슴은 설레이고, 만물은 활동을 주춤하는 9월. 그러나 가을바람과 밤낮의 심한 기온차의 심술은 여자의 아름다움을 창조하고자 하는 마음을 시샘하며, 여심의 가슴에 응어리를 만든다.