Earticle

익산 미륵사지 석탑은 백제 무왕대에 창건되어 몇 차례 수리 및 개축작업을 하면서 현 상태를 유지해 왔으나 최근에 구조적인 불균형이 심화되어 탑의 원형에 따른 보존과학적 수복을 위해 해체중이다. 이 탑의 원형은 평면방형탑으로 9층으로 추정되나 최근까지 일부 6층까지만 남아 있었다. 붕괴되어 망실된 부분은 1915년 일본인들이 콘크리트를 이용하여 불안전 탑의 형태를 고정시켜 놓았다. 현재 암석의 표면에는 침전물질이 피각되어 백화현상을 유발하였고 이로 인해 원암의 조직과 색상이 훼손되어 있다. 따라서 표면에 피각된 이차적 무기 오염물질의 종류와 산출상태 및 오염종을 정량 분석하였다. 또한 용해실험을 통해 가용성 오염종을 규명하고 이에 대한 오염물질을 세정하는데 필요한 조건을 제시하였다. 이 결과는 석조문화재 표면의 무기오염종을 정량적으로 규명할 수 있는 자료를 제공할 것이며, 백화현상을 제어 할 수 있는 표면 세정제의 보존과학적 적용에 기여할 것이다.

The Mireuksaji stone pagoda of the Iksan was built in Muwang King of Baekjae Kingdom and has maintained its present status through several rebuilding process. Recently, the structural unbalance of the pagoda has worsened, so for scientific maintenance recovery of its original pagoda form, the pagoda is under dismantling process. The original form of this pagoda is being presumed to be a plane square pagoda of nine stories, though only a portion of six stories remains until today. The destroyed part from collapse was liked in insecure pagoda form by Japanese in year of 1915. On the surface of the stone which has gone through the present time, efflorescence appeared as precipitation substance over crusted and due to this phenomenon, the structure and color of thee original stone haven't been preserved. Therefore, quantitative analysis on its kind, emitted status and contamination type of secondary inorganic contamination substance of the over crusted surface were analyzed. Also through reaction experiments, contamination type was defined and tests have been applied to find the requirements that will wash out the contaminants. The result of this study will provide the base of quantitative analysis on the kind of inorganic contamination of the surface of stone assets, and it shall also contribute to the application of scientific maintenance recovery of surface cleaner for efflorescence.

The objective of this study is to investigate effect of air cleaner operated during pig breeding period on stress hormones of pigs and their pork quality. The stress hormones (cortisol, epinephrine and norepinephrine) in blood sample of pigs reared in the housing rooms with or without air cleaner have been measured according to a pig’s rearing stage: 0 day (farrowing), 21st day (farrowing?weaning), 70th day (weaning?nursery), 140th day (nursery?growing), and 180th day (growing?fattening). The comparison of pork quality according to the application of an air cleaner was performed through the carcass analysis of the pigs shipped from swine house. The levels of cortisol, epinephrine, and norepinephrine in pigs reared in housing rooms with and without air cleaners were found to be within the range of normal reference values. Among pork quality evaluation items, the thickness of intermuscular fat and final carcass grade of pigs raised in housing room with air cleaner was generally superior to those of pigs raised in housing room without air cleaner (p < 0.05). Based on the results obtained from this study, it is concluded that air cleaner does not have a significant effect on reducing pig stress but contributes to improving pork quality in pig breeding.

Chronic wasting diseases of pigs and respiratory diseases of farm workers by exposure to various air pollutants in pig building are hygienic problems for contemporary pig production industry to solve urgently. This study was performed to evaluate contributions of air cleaner to air pollutants and pig productivity under on-site situation of commercial pig building. Air pollutants concentration and pig’s productivity index between the control room and the treatment room has been monitored for six months according to pig’s rearing stage: 0 day (farrowing), 21st day (farrowing?weaning), 70th day (weaning?nursery), 140th day (nursery?growing) and 180th day (growing?fattening). Generally mean concentrations of air pollutants derived from pig building were relatively higher in the control room than in the treatment room. The reduction efficiencies of air cleaner for air pollutants were 5%?10% for 0 day, 10%?20% for 21st day, 15%?25% for 70th day, 20%?35% for 140th day and 30%?45% for 180th day, respectively. Furthermore, application of air cleaner had a positive effect on pig’s body weight gain, feed conversion, pig activity index and mortality rate through all the pig’s rearing steps. The pig’s body weight gain and pig activity index showed significant correlations with total suspended particle (TSP) and particulate matter (PM)2.5, and TSP and airborne fungi, respectively.

배경: 본 연구의 배경은 최근 기독교 교세의 약화로 기존 목회자들이 직업을 가지는 경우가 늘고 있다는 점에서 시작한다. 목회자들이 직업을 가진 원인으로는 대부분 경제적 문제로 직 업을 가지며 준비되지 않은 직업의식으로 심리적 문제를 가지는 경우가 많다. 심리적 어려움 의 원인으로는 목회자와 직업 사이에 나타나는 직업 정체성 문제, 목회와 경제활동을 겸해야 하는 것에 대한 죄책감, 낫은 자존감을 들 수 있다. 따라서 이중직 목회로 인해 직업 정체성 문제로 어려움을 겪는 이들에게 정체성 형성과정을 세밀하게 들여다보는 것은 의미가 있다. 목적: 본 연구는 직업을 가진, 이중직 목회자들이 취업 후 목회와 직업 사이에서 정체성 문제 로 나타나는 심리적 문제의 원인과 이중직 목회자의 정체성을 확립하는 과정을 기술하는 데 목적이 있다. 동시에 직업 정체성 형성과정에서 지인들의 도움 요소를 찾고자 한다. 방법론/접근 : 본 연구는 이중직 목회자들이 겪는 심리적 문제 중 하나인 목회와 직업 사이에 나타나는 직업 정체성 문제의 극복 과정을 자문화기술 지로 접근하였다. 결과/결론 : 연구의 결론은 첫째, 이중직 목회자의 직업 정체성 형성과정을 통해 목회와 직업 에 대한, 고정의식의 변화를 촉진하는 계기가 되었다. 둘째, 연구자인 나는 이중직 목회 경험 을 통해 목회자로서의 정체성을 형성하는 계기가 되었다. 시사점 : 본 연구의 시사점은 이중직 목회를 경험한 목회자가 자신의 이야기를 자문화 기술 지 형태로 연구한 질적 연구라는 점이다. 이는 이중직 목회를 하며 겪는 정체성 문제의 해결 과정에 대하여 목회자 본인의 이야기를 연구자의 입장이 되어 연구하여, 보다 경험을 생생하 게 드러내었다는 점에서 의의가 있다.

Background: The background of this study begins with the fact that, due to the recent weakening of the Christian church, the number of existing pastors having jobs is increasing. The reason for having jobs is that they are not prepared for economic problems, and many of them have psychological problems after having jobs. The causes of psychological difficulties include the problem of professional identity that appears between pastors and jobs, guilt about having to combine ministry and economic activities, and low self-esteem. Therefore, it is meaningful to look closely at the identity formation process of those who have difficulties with professional identity problems due to dual-job ministry. Purpose: The purpose of this study is to describe the causes of psychological problems that dual-career pastors experience as identity issues between their ministry and their job after employment, and the process of establishing their identity as dual-career pastors. At the same time, it seeks to find helpful factors from acquaintances in the process of forming their professional identity. Methodology/Approach: This study attempts to approach the process of overcoming the problem of occupational identity that arises between ministry and work, one of the psychological problems experienced by dual-career pastors, through autoethnography. Implications: The conclusions of the study are as follows. First, through the process of forming the professional identity of a dual-career pastor, it became an opportunity to promote a change in fixed consciousness about ministry and occupation. Second, as a researcher, I was able to form my identity as a pastor through my experience of dual-career ministry.The implication of this study is that it is a qualitative study in which a pastor who experienced dual ministry studied his or her own story in the form of an autoethnographic report.

Rapid industrialization and reconstruction efforts resulting from various wars have produced significant pollution and overconsumption of natural resources causing significant global climate anomalies, especially within the concrete industry. As such, the last few decades have called for increasing demand in both eco-friendly concrete developments and concrete for protective structure implementation. This study aims to investigate avenues for the development of an eco-friendlier HSC for use in both general and protective applications. Two methods will be explored, firstly, the heavy reduction of cement targeting a minimum of 40% and maximum of 80% cement replacement when compared to a reference mix that is comparatively low in cement to other typical high-strength concretes. And secondly, the application of functionally graded concrete where the newly developed HSC will be placed in the most functional regions of the member assessing flexural capacity. Research findings detail small or large strength reductions in the HSC material up to 80% replacement compared to the reference material. HSC with 80% replacement of cement detailed an early strength of 41 MPa, and 60% replacement detailed strengths of up to 75 MPa when reinforced with 2.0 wt% of arc steel fibers, exceeding the target strength of 70 MPa. Furthermore, for FGC specimens, early age strength development under normal curing regimes led to reduced strength compared to HSC specimens, due to strength development in the NC region. However, steam cured specimens and 28-day strength specimens detailed near similar strengths to similar mono- HSC specimens. These materials show suitability for use in general construction and the protective construction industry. Reduced material emissions, and use of zero(low)-cost by products will significantly reduce the financial and environmental impact of restoration as well as strengthening of existing structures. Further supporting construction and recovery efforts pre- and post-destruction event, through reduced economic and environmental impacts.

2020년 현재, 중국발 미세먼지와 국내 미세먼지의 영향으로 대한민국의 뿌연 하늘은 봄철만이 아닌 가을/겨울철에도 흔히 볼 수 있는 일상이 되었다. 2013년, 세계보건기구 산하의 국제암연구소에서는 미세먼지를 사람에게 발암이 확인된 1군 발암물질로 지정하였다. 본 연구의 목적은 미세먼지 관련 디자인 연구 5편을 이론적으로 고찰하고, 시중에 판매되고 있는 웨어러블 공기청정기 3종의 사례분석을 통해 문제점을 도출하여, 개선된 개방형 웨어러블 공기청정기를 제안하는데 있다. 검증방법으로는 워킹 프로토타입을 제작하여 미세먼지의 감소량 측정하였다. 본 연구는 사례분석을 통해 웨어러블 공기 청정기의 세가지 디자인 인사이트를 도출하였다. 첫째, 얼굴에 닿는 면적을 최소화하여 개방감을 최대화한다. 둘째, 공기가 나오는 노즐을 호흡기관과 가까이하여 공기청정 능력을 극대화한다. 셋째, 모터의 위치는 소음을 고려하여 귀로부터 최대한 멀리 위치하도록 한다. 이를 바탕으로 사용자의 착용감을 높이고 공기 청정능력을 극대화한 개방형 웨어러블 공기 청정기 디자인을 제안하였다. 본 연구가 향후, 웨어러블 공기청정기의 보급률을 높이고 사용자의 호흡기 건강을 지킬 수 있는 계기가 되기를 바란다.

As of 2020, due to the influence of fine dust from China and domestic dust, the cloudy sky of Korea has become a daily routine not only in spring but also in autumn/winter. In 2013, the International Cancer Institute under the World Health Organization designated fine dust as a group 1 carcinogen that has been confirmed to be carcinogenic to humans. The purpose of this study is to theoretically review 5 fine dust-related design studies, by analyzing the case of three types of wearable air purifiers on the market, it is to propose an improved open wearable air purifier. As a verification method, a working prototype was produced to measure the amount of fine dust reduction. Therefore, this study derived three design insights of wearable air cleaner through case analysis. First, it maximizes openness by minimizing the area touching the face. Second, the nozzle where the air comes out should be close to the respiratory organ. Third, position of the motor is to be as far away as possible from the ear considering the noise. Based on this, I suggested an open-type wearable air purifier design that maximizes the user openness and improves the wearing comfort. I hope that it will be an opportunity to increase the coverage of wearable air cleaner and protect the respiratory health of users.

The vacuum cleaner motor runs at very high speed for suction power. Specially, motor power is provided by the impeller being rotated at very high speed. The centrifugal fan consists of the impeller, the diffuser, and the circular casing. Due to the high rotating speed of the impeller and small gap distance between the impeller and the diffuser, the level of noise in the centrifugal fan is at BPF(Blade Passage Frequency) and its harmonic frequencies. In order to calculate the sound pressure of centrifugal fan, unsteady flow data are needed. The cause of noise is obtained by dividing the fluid noise by exhaust flow of fan and vibration noise by rotational vibration of vacuum cleaner fan motor. Until now, an accelerometer has been used to measure vibration. However, it can not measure vibration in some parts of brush and commutator because of motor construction and 3-D vibrating mode. This study was conducted to perform accurate analysis of vibration and aerodynamic sound for fan motor in a vacuum cleaner using a laser vibration analyzer. A silent fan motor can be designed using the data measured in this study.

태양전지(Photovoltaic, PV) 모듈의 층간 접착제로 사용된 EVA(Ethylene Vinyl Acetate)를 초음파 조사(irradiation)를 이용하여, 선택적으로 분해함으로써 모듈 내 실리콘웨이퍼(Si-wafer)로 제조된 셀(cell)을 분리, 회수하는 연구를 진행하였다. 본 실험에 사용한 초음파 발생장치는 bath-type의 초음파 세척기 (Output: 130 W, Frequency: 40 kHz)로, PV모듈과의 거리는 2 cm로 고정하고 유기용매 종류, 농도, 온도를 조절하면서 EVA 분해 및 셀의 분리 최적 조건을 도출하였다. 55℃ 5 M인 조건에서는 용매 종류에 상관없이 160 min 이내에 EVA층의 완전 분해는 가능하였으나, 분해과정 중 발현되는 팽창현상(swelling)에 의해 셀의 일부분이 파손된 상태로 회수되었다. 반면에 65℃, 5 M조건에서는 셀의 파손이 억제된 상태로 회수 가능하였으며, 이는 온도 상승에 의해 EVA 성분의 분해속도가 상승되고, 이로 인해 EVA층의 팽창현상이 발현되기 전에 분해가 일어난 결과라고 판단된다.

Using ultrasonic irradiation, the separation and recovery of PV cell, made of silicon wafer, from PV module was carried out through selective decomposition of EVA used as an interlaminated binder. The ultrasonic cleaner of bath-type (Output: 130 W, Frequency: 40 kHz) was used as an ultrasonic apparatus in this research. With the fixed distance of 2 cm, from ultrasonic generator to PV cell, the experiment of EVA decomposition was performed in various organic solvents such as Toluene, Trichloroethylene, O-dichlorobenzene, Benzene. And also their concentrations and temperature was changed to survey the optimum conditions. However EVA can be decomposed perfectly at 55℃ within 160 min in 5 M of all kinds of solvent, PV cell may be recovered with being damaged or broken severely. This damage may be resulted from the swelling of EVA in the process of decomposition. Whereas, at the condition of 5 M at 65℃, PV cell can be recovered with the state of minor damage or crack. This implies that the decomposition rate of EVA increases with an increase of temperature, thereby EVA can be decomposed before the swelling of EVA layer. Conclusively, it is possible for PV cell to be recovered within 40 min, at 65℃ in 5 M, with less damage.

The runner system of the injection mould and the injection volume of the injection molding process greatly affect the quality of the produced part. The goal of this paper is the design of the runner system and the prediction of the injection volume for the injection moulding of a housing part of small-size air cleaner to improve the formability through the three-dimensional injection moulding analysis. The effects of the runner system of the mould on the injection moulding characteristics are investigated. From the results of the investigation, a proper design of the runner system with uniform filling characteristics and the minimized defect formation is obtained. In addition, the influence of the moving distance of the screw on filling characteristics, weldline formation and deformation characteristics is examined. From the results of the examination, an appropriate moving distance of the screw for the housing part of small-size air cleaner is estimated.

본 실험은 구강 내 혐기성 프라그 형성과 충치유발세균에 대한 살균력 실험, 치태형성 억제효과와 치태 제거효과 평가, 가글 후 배출액 내에 포함되어 있는 세균 동정을 통하여 구강청결제 덴탈크리어의 효능을 평가하는데 있다. Streptococcus gordonii에 대한 살균실험을 한 결과 초기접종균수가 2.9×105 CFU/ml에서 30±3초 후 4.3×104CFU/ml (85.1%) 살균력을 보였으며 1분±5초 후에는 <10 CFU/ml으로 99.9% 살균력을 보였다. Streptococcus sobrinus에 대한 살균실험을 한 결과 초기접종균수가 9.8×104 CFU/ml에서 30±3초 후 1.1×104 CFU/ml (88.8%) 살균력을 보였으며 1분±5초 후에는 <10 CFU/ml으로 99.9% 살균력을 보였다. 피실험자 8명의 치아면 개수는 혀쪽과 볼쪽을 모두 합하여 총 448개였다. 실험결과 억제 효과는 1.75개(56면/총 448 치아면, 12.25%), 치태제거 효과는 평균 2.47개(79면/총 448 치아면, 17.63%)로 치태억제 효과보다 치태를 제거하는 효과가 더 큰 것으로 나타났다. 또한 덴탈크리어로 가글한 후 배출되는 균은 혐기성 세균 Bifidobacterium inopinatum, Scardovia wiggsiae 2종, 호기성 세균의 경우 Neisseria meningitidis, Rothia mucilaginosa, Rothia dentocariosa, Streptococcus mitis, Septococcus oralis, Streptococcus australis, Parascardovia denticolens 7종이 확인되었다.

This study is to the evaluation of efficacy on oral cavity cleaner, Dental CleanerTM through the examination of sterilizing power on anaerobic plaque formational bacteria and bacteria lead to carious tooth, the evaluation of effects of inhibition and removal of dental calculus after gargle, and the identification of bacteria from exhausted solution after gargle. In result of sterilizing power on Streptococcus gordonii, the sterilizing power was showed 85.1% after 30 ± 3 sec, and 99.9% after 60 ± 5 sec. In the case of Streptococcus sobrinus, the sterilizing power was showed 88.8% after 30 ± 3 sec, and 99.9% after 60 ± 5 sec. The effect of inhibition is 1.75 and the removal effect of dental calculus is 2.47 after gargle. this result was showed that the removal effect is more larger than the inhibition effect. Also, in our identification of bacteria from exhausted solution after gargle, we confirmed two kinds of anaerobic bacteria, Bifidobacterium inopinatum and Scardovia wiggsiae. In the case of aerobic bacteria, we found 7 species, Neisseria meningitidis, Rothia mucilaginosa, Rothia dentocariosa, Streptococcus mitis, Septococcus oralis, Streptococcus australis and Parascardovia denticolens.

자신의 상업적 이익과 무관하게 대화를 통해 제품, 서비스에 대한 정보를 전달하는 행위를 말하는 구전 커뮤니케이션 연구는 1950년대 사회적 커뮤니케이션 패턴에 대한 연구에서 시작된 것으로 1980년대 이후 미케팅 및 소비자행동학 등의 다양한 분야에서 연구되고 있다. 특히, COVID–19 이후 디지털전환(Digital Transformation, DT)이 가속 화되면서, 각종 SNS 사용이 일상화됨에 따라 온라인 구전(eWOM, electronic Word of Mouth)이 더욱 더 활성화되고 있다. 현대 소비자들은 기업이 일방적으로 제공하는 제 품 정보보다는 다른 사용자들과 동질감을 가지고 제품에 대한 정보를 공유하며 신뢰 관계를 구축하는 문화가 보편화된 시대에서 소비활동을 수행하고 있는 것이다. 이에 세계 각지에서 국경을 초월한 기업활동을 전개하고 있는 글로벌기업들은 기존의 특정 지역에 국한한 기업활동에서 벗어나 글로벌 고객의 목소리에 경청하며 소비자와의 상 호 커뮤니케이션을 주요 마케팅 수단으로 중요시하고 있다. 본 연구는 글로벌기업 D사의 청소기에 대해 한국과 일본의 소비자들이 남긴 온라인 구전 소비자평을 대상으로 컬처마이닝 빅데이터 분석 기법을 적용하여 각국 소비자들 의 차별화된 감성을 발견하는 방안을 모색하고자 하는 것이다. 동일 물건의 사용에 대 해서도 각국 소비자들이 중요시 여기는 제품 특성 및 감성에 있어서 차이점을 발견할 수 있었는데, 본 연구를 통해 컬처마이닝의 유용성을 확인할 수 있는 것이다.

Word–of–mouth communication research is the act of delivering information about products and services through dialogue regardless of one's commercial interests. This type of reserach began in the 1950s with the study of social communication patterns. It has also been studied in fields such as marketing and consumer behavior since the 1980s. Since COVID–19, digital transformation (DT) has accelerated. The use of various SNS has become more common, and electronic word of mouth (eWOM) is becoming more active. Modern consumers are conducting consumption activities in an era where a culture of sharing product information and building trust relationships with other users with the same sense of identity. This new method of product consumption disregards product information provided by companies unilaterally. Accordingly, global companies engaged in cross–border business activities are focusing on mutual communication with consumers as a major marketing strategy. This strategy allows companies to listen to the voices of global customers, separate from existing business activities limited to specific regions. The purpose of this study is to discover consumer opinion by applying big data analysis techniques to online word–of–mouth consumer reviews left by consumers in Korea and Japan about the vacuum cleaners of global company D.

본고는 최근 화두로 떠오른 미세먼지와 그에 대한 저감 대책에 관한 연구를 시안에 설치된 초대형 공기청 정기를 중심으로 진행하였다. 중국 정부는 2017년, 초대형 공기청정기 ‘추마이타’의 완공 후 1년간 시험가동 결과, 10㎢ 범위 내 공기의 PM2.5 농도가 11% ~ 19% 감소함을 발표했다. 이에 본고의 연구자들은 답사 간 여러 장소들 을 돌아다니면서 초미세먼지의 농도를 측정하고, 이것이 초대형 공기청정기의 위치를 기준으로 직선거리에 따른 상관관계를 보이는지 확인하고자하였다. 추가적으로 특정 장소가 가진 독특한 특징이 초미세먼지 농도에는 어떤 영향을 미치는지 간접적으로 확인해보고자 했다. 하지만 답사 간, 개발 연구진들과 개발업체 측에서 미세먼지 측정 결과를 분석 중으로 올해 3월부터 가동이 잠정 중단된 상태라는 것을 확인할 수 있었다. 이에, 중국의 초대형 공기 청정기 ‘추마이타’건설과 관련하여 한국과 일본에서는 미세먼지 저감을 위해 각각 어떠한 노력을 보이고 있는지 살펴보았다.

In this study, we researched on ultra fine dust and measures for reducing the concentration of ultra fine dusts, focusing on a super-sized air cleaner located in Xi An. After completion of the super air cleaner 'Chiraima', the Chinese government conducted a trial operation for one year. The Chinese government announced that the PM2.5 concentration of air within 10km2 decreased by 11%~19% as a result. In this study, we investigated the concentration of ultrafine dusts in various places during the exploration, and tried to find out the correlation of the concentration of ultrafine dust with the distance of straight line based on the position of the super clean air cleaner. Additionally, we wanted to ascertain indirectly how peculiar features of the specific place affect the concentration of ultrafine dusts. During the investigation, however, it was confirmed that the operation was temporarily stopped from March of this year to analyze the results of the fine dust measurement. Therefore, we have examined how korea and japan are making efforts to reduce fine dust considerating china's super - air cleaner 'Chiraima'

The cleaner chromate production process using sub-molten salt has been successfully simulated using METSIM in order to evaluate the mass balance, energy consumption, and other conditions necessitate for the process scaling up. Based on the simulation results, the mass and heat balance of every operation unit are obtained, providing valuable reference for the process design. Further, the heat exchange network optimization using pinch technology is performed, enabling the reduction of the heat and cool energy consumption by 31.5% and 31.7%, respectively.