건축물내 일산화탄소 경보기 설치기준에 관한 연구

강승규(Kang Seung Kyu),최경석(Choi Kyung Suhk) 한국가스학회 2008 한국가스학회지 Vol.12 No.4

최근 5년간 국내 가스사고 중 CO중독사고는 사망 36명, 부상 79명이 발생하였으며, 전체 가스 사고에 비해 인명피해율이 8배나 높게 나타나고 있다. 이러한 CO중독사고의 대부분이 노후 가스보일러 및 다중가스 사용시설의 배기통 불량에 의한 가스누출사고로 조사되고 있다. 본 연구에서는 실험을 통해 건축물내 보일러실의 배기통 불량에 의한 CO가스의 누출확산 메커니즘을 해석하였다. 배기통에서 누출된 CO가스는 건축물 내부의 천정부근에서 가장 높은 농도분포를 보인다. 또한 CO경보기 설치 실험을 통해서 천정부근의 CO경보기가 가장먼저 작동하고, 30~40분 경과한 후에 바닥 및 중간에 설치된 경보기가 작동하는 것을 확인하였다. 본 연구를 통해 CO경보기의 적정 설치위치를 확인하였으며, 이 결과를 토대로 건출물내 CO경보기 설치위치를 제안하였다. In the last five years, 36 people died and 79 were wounded because of carbon monoxide poisoning accident. A CO poisoning accident is higher than any other gas accident in the rate of deaths/incidents. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread mechanism of CO gas released from leakage hole of exhaust tube was analyzed by concentration measuring test. A CO gas leaked form exhaust tube in a building was the highest concentrated near the ceiling. CO alarm sets installation test confirmed that the alarm sets near the ceiling operated first, and the bottom and middle sets operated after 30~40 minutes. Through these experiments, the reasonable installation location of CO alarm was made certain and suggested.

CO₂ 지중저장 시 단층 안정성 평가

김현우(Hyunwoo Kim),천대성(Dae-Sung Cheon),최병희(Byung-Hee Choi),최헌수(Hun-Soo Choi),박의섭(Eui-Seob Park) 한국암반공학회 2013 터널과지하공간 Vol.23 No.1

CO₂를 지중저장하는 과정에서 유체압력의 증가로 인한 단층 활성화는 저장영역의 기밀성 유지에 중대한 영향을 미치며, 상황에 따라 저장기능의 회복 또는 저장중인 CO₂의 처리 문제 등으로 확대될 수 있다. 따라서 현지조사 결과의 불확실성을 최소화하고 이를 토대로 부지 선정과 주입압력 결정 단계에서 실제 조건에 가까운 모델링을 수행하여 저장영역 내 단층의 안정성과 CO₂ 누출 가능성을 평가하여야 한다. 본 연구에서는 이와 관련된 기존 연구 결과들을 살펴봄으로써 연구 동향 및 연구 방법에 대한 정보를 제공하고자 하였다. 먼저 인위적으로 지반에 주입된 유체 또는 자연 생성되어 응집되어 있던 CO₂에 의해 지진활동이 일어났던 사례들을 조사하였으며, 현지응력의 크기 및 방향, 단층 및 유체압력 분포 자료를 획득하는 방법에 대해 살펴보았다. 그리고 단층 활성화 가능성 평가 및 지진활동 시 진동 크기 추정, 활성화에 따른 CO₂ 누출 모델링 관련 연구 사례를 정리하였다. Increase of pore fluid pressure resulting from injection of CO₂ may reactivate pre-existing faults, and the induced seismic activities can raise the safety issues such as seal integrity, restoration of storage capacity, and, in the worst case, removal of previously injected CO₂. Thus, fault stability and potential for CO₂ leakage need to be assessed at the stage of site selection and planning of injection pressure, based on the results of large-scale site investigations and numerical modeling for various scenarios. In this report, studies on the assessment of fault stability during injection of CO₂ were reviewed. The seismic activities associated with an artificial injection of fluids or a release of naturally trapped high-pressure fluids were first examined, and then site investigation methods for the magnitude and orientation of in situ stresses, the distribution and change of pore fluid pressure, and the location of faults were generally summarized. Recent research cases on possibility estimation of fault reactivation, prediction of seismic magnitude, and modeling of CO₂ leakage through a reactivated fault were presented.

PRINCIPAL COFIBRATIONS AND GENERALIZED CO-H-SPACES

Yeon Soo Yoon 충청수학회 2017 충청수학회지 Vol.30 No.1

For a map p : X → A, there are concepts of co-H p -spaces, co-T p -spaces, which are generalized ones of co-H-spaces [17,18]. For a principal cofibration i r : X → C r induced by r : X ′ → X from ι : X ′ → cX ′ , we obtain some sufficient conditions to having extensions co-H p¯ -structures and co-T p¯ -structures on C r of co-H p -structures and co-T p -structures on X respectively. We can also obtain some results about co-H p -spaces and co-T p -spaces in homology decompositions for spaces, which are generalizations of Golasinski and Klein’s result about co-H-spaces.

Techno-economic evaluation of CO₂ enhanced oil recovery (EOR) with the optimization of CO₂ supply

Kwak, Dong-Hun,Kim, Jin-Kuk Elsevier 2017 International journal of greenhouse gas control Vol.58 No.-

<P><B>Abstract</B></P> <P>Enhanced oil recovery (EOR) by the injection of CO<SUB>2</SUB> into the oil reservoir is widely practiced for stimulating oil production, which is also favorable for CCS (carbon capture and storage) due to the effect of sequestrating CO<SUB>2</SUB> into the empty space of the reservoir along with oil production. Although economic and environmental benefits can be obtained through CO<SUB>2</SUB> EOR, it requires considerable capital investment and expenditure for the operation. Therefore, it is helpful to assess systematically the life-time effect of CO<SUB>2</SUB> EOR by evaluating the capital and energy flow.</P> <P>Rather considering collectively overall mass flows of CO<SUB>2</SUB> purchase, recycling, sequestration and oil production throughout the whole life-cycle, this study presents the assessment of CO<SUB>2</SUB> EOR in a multi-period manner in which CO<SUB>2</SUB> supply is systematically scheduled, subject to the availability of external CO<SUB>2</SUB> sources and time-dependent relationship between CO<SUB>2</SUB> injection, CO<SUB>2</SUB> supply and CO<SUB>2</SUB> recycle. The methodological procedure for the proposed economical assessment is presented with the case study, in which CO<SUB>2</SUB> supply schedule is optimized to maximize net present value (NPV), considering the constraints imposed by time-dependent availability of CO<SUB>2</SUB> supply sources. Sensitivity analysis of key design parameters is performed to gain conceptual insights for the design and operation of CO<SUB>2</SUB> EOR.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Techno-economic evaluation of CO<SUB>2</SUB> enhanced oil recovery (EOR). </LI> <LI> Systematic consideration of operating characteristics for CO<SUB>2</SUB> suppliers for EOR. </LI> <LI> Optimization framework for CO<SUB>2</SUB> EOR operation subject to CO<SUB>2</SUB> supply scheduling. </LI> </UL> </P>

WHO IS TO BLAME? EFFECTS OF CAUSAL LOCUS WHEN CO-PRODUCTION RESULTS ARE UNSATISFACTORY

Larissa Carine Braz Becker,Nat?lia Ara?jo Pacheco,Vinicius Andrade Brei 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.7

Co-production is defined as customer participation in production activities that generate a result to be consumed (Etgar, 2008). Previous research has shown the positive effects of co-production, such as satisfaction, perceived control, and perceived quality (Chan, Yim, & Lam, 2010; Golder, Mitra, & Moorman, 2012; Hunt, Oneto, & Varca, 2012). However, knowledge about the potential negative consequences from co-production is scarce. Despite the importance of the role of causal locus in the generation of unsatisfactory results, to date, this subject has not been properly studied. Considering that co-production is increasingly common in contemporary consumption contexts, this paper aims to broaden knowledge about unsatisfactory results from co-production. Based on two experimental studies, we analyze the role of the causal locus of failures on customer regret and disappointment, taking into consideration the self-serving bias. The results show that a consumption situation with an unsatisfactory regret tends to be higher when the consumer takes the blame than when the causal locus is attributed to the company. When the causal locus is uncertain, regret is higher than disappointment and higher than the regret experienced when the company or the service employee is blamed. Because regret is associated with internal causal attribution, these results contradict the self-serving bias literature, which affirms that people are more likely to make external than internal attributions for failures (Mezulis, Abramson, Hyde, & Hankin, 2004; Weiner, 2010). The internal failure attribution converges with the idea that consumer participation in production implies more responsibility over the result (Bitner, Faranda, Hubbert, & Zeithaml, 1997; Prahalad & Ramaswamy, 2004).When the causal locus is attributed to the company or to the service employee, disappointment towards the company tends to be higher than in the other conditions and higher than regret. Study 2 tested whether consumers who co-produce would take responsibility for a failure and blame themselves in situations where the causal locus was undetermined. The results once again contradicted the self-serving bias literature in a scenario with co-production. Consumers who co-produced experienced more regret and less disappointment towards the company, and they blamed themselves more intensely than the consumers who did not co-produce. Therefore, the consumers who co-produce take more responsibility for dissatisfying results and, consequently, regret their actions to a higher degree than those consumers who do not co-produce. These results show that even when co-production fails to generate a satisfying result for the consumer, it may be positive for the company because it provides a context in which both the consumer and the company may be responsible for the failure. When the company is blamed, consumers experience less regret and more disappointment towards the company than when the consumer is the one to blame. But when the consumer is blamed or the causal locus is uncertain, situations that are both possible in a co-production context, then consumers experience more regret and less disappointment towards the company.

총요소생산성을 고려한 한국의 CO₂ 배출량에 대한 EKC 가설 검증: 지역별 CO₂ 배출량과 GRDP를 중심으로

김수이,정경화,Kim, Suyi,Jung, Kyung Hwa 한국자원경제학회 2014 자원·환경경제연구 Vol.23 No.4

This research tested the EKC (Environment Kuznets Curve) Hypothesis using the $CO_2$ Emissions by region and GRDP. We built the panel data set on the 15 local government region from 1990 to 2010 for this analysis. GRDP, population and total factor productivity was considered as the factors influencing on the regional $CO_2$ Emissions. Analysis method in this research is panel GLS model as Lantz and Feng (2006). The results show that the EKC hypothesis did not hold in Korea but there is inverted U relationship between the $CO_2$ Emissions and total factor productivity. As the total factor productivity grows, the $CO_2$ increased but decreased after a certain level. 본 연구는 우리나라의 지역별 $CO_2$ 배출량과 지역별 GRDP데이터를 사용하여 EKC(Environment Kuznets Curve)를 검증하였다. 이 분석을 위해서 1990년부터 2010년 기간 동안 우리나라의 15개 광역지방자치단체를 대상으로 한 패널데이터를 구축하였다. 지역별 $CO_2$ 배출량에 영향을 미치는 요인으로는 일인당 GRDP, 인구, 총요소생산성 등을 고려하였다. 그리고 이러한 요인들이 $CO_2$ 배출량에 영향을 미치는데 있어서 역 U자형 가설이 성립하는지를 검증하였다. 본 연구에 사용한 분석 방법은 Lantz and Feng(2006)에서와 마찬가지로 패널 GLS 모델을 사용하였다. 분석결과에 의하면 우리나라의 경우 EKC 가설이 성립하지 않았지만 총요소생산성의 경우에는 $CO_2$ 배출량과 역 U자형 관계가 성립하였다. 본 연구의 의의는 특히 기술 진보를 대변하는 총요소생산성이 증가할수록 $CO_2$ 배출량이 증가하지만 일정수준 이후에는 $CO_2$ 배출량이 감소한다는 것이다.

CO₂와 N₂ 혼합 비율에 따른 포장 닭고기 가슴육의 냉장 저장 중 품질 특성

채현석,나재천,최희철,김민지,방한태,강환구,김동욱,서옥석,함준상,장애라,Chae, Hyun-Seok,Na, Jae-Cheon,Choi, Hee-Cheol,Kim, Min-Ji,Bang, Han-Tae,Kang, Hwan-Ku,Kim, Dong-Wook,Suh, Ok-Seok,Ham, Jun-Sang,Jang, Ae-Ra 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.1

The physicochemical characteristics of chicken breast were determined to identify the optimal ratio of $CO_2$ and $N_2$ to maintain chicken breast quality during cold storage for 6 d. The mixing ratios of $CO_2$ and $N_2$ were 20:80, 40:60, 60:40, and 80:20, respectively. The pH of the chicken breast packed with 80% $CO_2$ and 20% $N_2$ was lower than that of the control on day 1 (p<0.05). The lightness ($L^*$) of the breast increased with increasing $CO_2$ during storage (p<0.05), whereas no difference was found for redness ($a^*$) and yellowness ($b^*$). A lower volatile basic nitrogen level was found for chicken breasts exposed to higher $CO_2$ levels. Furthermore, lipid oxidation of the chicken breast packed with $CO_2$ decreased with increasing $CO_2$ level, and 40% $CO_2$ significantly reduced 2-thiobarbituric acid reactive substances (TBARS) values on days 1 and 6. The total number of microbes was reduced in chicken breast exposed to more than 40% $CO_2$ during storage days 3 and 6 (p<0.05); however, Escherichia coli was not affected by $CO_2$ level. Coliforms of chicken breast were reduced in the 40% $CO_2$ level on storage day 3. Moreover, tray-packed chicken breast exposed to 40% $CO_2$ did not collapse. These results suggest that 40% $CO_2$ and 60% $N_2$ were the optimal conditions for packaging chicken breasts during cold storage. 닭고기 가슴육에 대하여 가스를 넣지 않는 대조구와 $CO_2$와 $N_2$를 혼합 처리한 가스치환포장구로 나누어 냉장저장($4^{\circ}C$)한 결과 저장 1일에 80% $CO_2$의 첨가구에서 pH의 유의적인 감소를 나타내었다(p<0.05). 가슴육의 명도($L^*$)는 모든 저장 기간 동안 $CO_2$의 농도가 60% 이상일 때 대조구에 비해 유의적으로 증가하였으며 적색도($a^*$)와 황색도($b^*$)는 가스처리에 따른 유의적인 차이는 보이지 않았다. 단백질변성도(VBN)와 지방산패도(TBARS)는 대조구에 비하여 60% 이상의 $CO_2$ 처리구에서 감소를 보였다(p<0.05). 닭가슴육의 총균수는 저장 1일에는 가스 처리군간의 유의적인 차이를 보이지 않았으나 저장 3일과 6일에는 40% $CO_2$ 처리군에서 유의적인 감소를 나타내었다(p<0.05). 그러나 $CO_2$를 60-80%으로 고농도 처리 포장 하여 냉장 저장 시 포장 용기가 찌그러지는 현상이 발생하여 상품성의 저하를 초래하였다. 따라서 상기의 성적을 고려할 때 닭가슴살을 $CO_2$, $N_2$를 이용한 가스치환하여 포장 시에는 $CO_2$는 40% 이하로 $N_2$ 는 60%로 유지하는 것이 적절한 것으로 판단된다.

시멘트 생산과정에 따른 CaO 함량과 CO₂의 발생량

김상효,황준필,Kim, Sang-Hyo,Hwang, Jun-Pil 한국콘크리트학회 2013 콘크리트학회논문집 Vol.25 No.4

In this study, contents of limestone in cement manufactured by six domestic plants for Portland cement were investigated in terms of the strength and its relation to the $CO_2$ emission due to limestone material and its physical properties in cement manufacturing process. the relationship among CaO content, compressive strength, and $CO_2$ emission was surveyed for the limestone quantity in decomposition reaction and the loss of limestone quantity contained in each cement. As a result of $CO_2$ emission calculation for unit cement, it was found that the $CO_2$ emission due to decomposition of limestone was occupied 67% of total emission quantity. Furthermore, there was a difference in $CO_2$ emission quantity depending on the cement manufacturing process management. Also, it was shown that fossil fuel usage and material loss had a major influence as main factors of $CO_2$ emission. An increase in the CaO content in cement resulted in an increase in the compressive strength. On the contrary, CaO content and compressive strength were reduced with the growth of loss quantity of limestone. It was verified that the material and process management were more effective than CaO yield in cement manufacturing for $CO_2$ emission with the growth of $CO_2$ emission quantity. Pozzolanic materials such as PFA and GGBS in concrete mix affected the price, $CO_2$ emission and development of strength of concrete. 이 연구에서는 시멘트 생산공정에서 석회석 원료에 따른 $CO_2$ 배출량 및 그에 따른 물리적 특성을 파악하기 위해 국내 6개사의 보통포틀랜드시멘트에 대한 CaO 함유량 및 모르타르의 압축강도를 측정하였다. 탈탄산반응 시 발생되는 CaO와 각각의 시멘트에 함유된 석회석의 손실량에 대하여 CaO 함유량 및 압축강도, $CO_2$ 배출량과의 관계를 비교분석하였다. 단위 시멘트에 대한 $CO_2$ 배출량 산정 결과 석회석의 탈탄산에 따른 $CO_2$ 배출량이 전체 배출량의 67%가량 차지하였고, 시멘트 제조 시 공정관리에 따라 $CO_2$ 배출량에 차이가 있음을 확인하였다. 또한 $CO_2$ 배출의 주요 인자로 화석연료의 사용 및 재료 손실률이 지대한 영향을 미친다는 것을 확인하였다. 시멘트 내의 CaO 함유량이 증가함에 따라 압축강도 역시 증가하였으며, CaO 손실량이 클수록 CaO 함유량 및 압축강도는 감소하였으나 $CO_2$ 배출량은 증가함에 따라 시멘트 제조 시 CaO 생성량보다는 재료 및 공정관리가 $CO_2$ 배출에 더 영향력이 있음을 알 수 있었다. 그리고 포졸란계 혼화재인 PFA, GGBS를 사용함으로서 이에 따른 가격, $CO_2$ 배출 및 강도증진 효과가 있음을 확인하였다.

CO 합성을 위한 저급석탄-CO₂ 촉매 가스화 반응

이호용,이종대,Lee, Ho Yong,Lee, Jong Dae 한국응용과학기술학회 2016 한국응용과학기술학회지 Vol.33 No.3

본 연구에서는 합성가스 CO를 생산하기 위해 저급 석탄-$CO_2$ 촉매 가스화 실험을 수행하였다. 제조된 CO가스 특성은 키데코 탄과 신화 탄에 KOH, $K_2CO_3$, $Na_2CO_3$ 촉매들의 화학적 활성화 방법을 이용하여 조사되었다. CO 제조공정은 석탄과 화학약품 활성화 비율, 가스 유량, $CO_2$ 전환 반응온도와 같은 실험 변수 분석을 통해 최적화되었다. 제조된 합성 가스는 가스 크로마토그래피(GC)에 의해 분석 되었다. 실험조건 $T=950^{\circ}C$, $CO_2$ 유량 100 cc/min에서, 20 wt% $Na_2CO_3$가 혼합된 키데코 탄에 대해 98.6%, 20 wt% KOH가 혼합된 신화탄에 대한 98.9% $CO_2$ 전환율을 얻었다. 또한, 저급 석탄-촉매 가스화 반응은 동일한 공급 비와 반응 조건에서 97.8%, 98.8%의 CO 선택도를 얻었다. In this study, the experiments on optimal CO gas synthesis were conducted using low grade coal-$CO_2$ catalyst gasification reaction. The characteristics of generated CO gas were investigated using the chemical activation method of KOH, $K_2CO_3$, $Na_2CO_3$ catalysts with Kideco and Shewha coal. The preparation process has been optimized through the analysis of experimental variables such as ratio between activating chemical agents and coal, the flow rate of gas and reaction temperature during $CO_2$ conversion reaction. The produced CO gas was analysed by Gas Chromatography (GC). The 98.6% $CO_2$ conversion for Kideco coal mixed with 20 wt% $Na_2CO_3$ and 98.9% $CO_2$ conversion for Shenhua coal mixed with 20 wt% KOH were obtained at the conditions of $T=950^{\circ}C$ and $CO_2$ flow rate of 100 cc/min. Also, the low grade coal-$CO_2$ catalytic gasification reaction showed the CO selectivities(97.8 and 98.8 %) at the same feed ratio and reaction conditions.

A latent approach in the fashion retailing context: segmenting co-creator users

Carlota Lorenzo-Romero,María-del-Carmen Alarcón-del-Amo,Marta Frasquet-Deltoro 한국의류학회 2023 Fashion and Textiles Vol.10 No.1

Co-creation activities have shown dramatic development somewhat recently. The initial step of a productive co-creation technique originates from a comprehension of people’s practices inside of these websites. Based on the limited knowledge of online co-creation behaviour in the retail sector, particularly in fashion retailing, this study develops a latent class segmentation analysis that allows examining the diversity of co-creation behaviours. Thus, the main objective of this paper is to analyse the heterogeneity of co-creators’ behaviours in the online retail environment. This study examines different indicators that determine the co-creation behaviour of users such as co-creation value and activities, engagement with the company/brand, satisfaction with the co-creation process, intention to continue co-creating) in the Spanish fashion sector. Three different segments have been obtained: “full co-creator”, “co-creator oriented to the company/brand” and “co-creator oriented to other people” that show three distinct ways of co-creating with a fashion firm. The findings offer fashion retailers an interesting perspective for attracting customers to co-creation ventures during the fashion online shopping process.