초임계 용매를 포함한 Poly(propyl acrlate)와 Poly(Propyl methacrylate)의 이성분 및 삼성분계에 관한 상거동

변헌순,이하연 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.6

본 연구는 초임계 용매인 CO_2, 에틸렌, 프로판, 부탄, 프로필렌, 1-부텐, 디메틸에테르 및 CHCIF_2내에서 poly(propyl acrylate)와 poly(propyl methacrylate) 용액과의 고압 상거동을 측정하였다. 초임계 용매들과 poly(propyl acrylate) 및 poly(propyl methacrylate) 간의 상거동 측정 범위는 온도 23-186℃와 압력 2,400 bar까지 실험하여 나타내었다. poly(propyl acrylate)-CO_2혼합물은 약 2,070 bar 이내에서, poly(propyl acrylate)-에틸렌계는 1,400 bar 이하에서, poly(propyl acrylate)-프로판계는 1,880 bar 이하에서, poly(propyl acrylate)-프로필렌계는 450 bar 이하에서, poly(propyl acrylate)-부탄계는 2,200 bar이하에서, poly(propyl acrylate)-1-부텐계는 250 bar 이하에서, poly(propyl acrylate)-디메틸에테르계는 150 bar 이하에서 각각 용해되었으며, 이때 온도범위는 23-175℃이였다. poly(propyl methacrylate)-CO_2 혼합물은 2,900 bar 및 온도 240℃에서도 용해되지 않았다. poly(propyl methacrylate)-프로판계는 약 2,390 bar이하에서, poly(propyl methacrylate)-부탄계에 대해서는 2,100 bar이하에서, poly(propyl methacrylate)-프로필렌계에 대해서는 570 bar 이하에서 poly(propyl methacrylate)-1-부텐계는 310 bar 이하에서, poly(propyl methacrylate)-CHClF_2계에 대해서는 300 bar 이하에서, 그리고 poly(propyl methacrylate)-디메틸에테르계에 대해서는 170 bar이하에서 각각 용해되었으며, 이때 온도범위는 40-186℃사이였다. 또한 이성분 poly(propyl acrylate)-CO_2와 poly(propyl acrylate)-디메틸에테르계의 상거동 사이에 디메틸에테르를 공용매로 사용하여 5, 15 및 50wt% 첨가하여 구름점의 거동을 상임계용액온도 영역에서 하임계용액온도 영역까지 나타내었다. High pressure phase behavior data for poly(propyl acrylate) and poly(propyl methacrylate) with supercritical CO_2, ethylene, propane, butane, propylene, 1-butene, dimethyl ether, and CHICF_2 were measured in the temperature range from 23℃ to 186℃ and at pressures up to 2,400 bar. The cloud point were obtained at dissolved pressure below 2,070, 1,400, 1,880, 450, 2,200, 250, and 150 bar for poly(propyl acrylate) in supercritical CO_2, ethylene, propane, propylene, butane, 1-buthen, and dimethyl ether, respectively. The temperature range is 23-175℃. The poly(propyl methacrylate) does not dissolve in CO_2 at temperature of 240℃ and pressure 2,900 bar. The poly(propyl methacrylate)-propane, poly(propyl methacrylate)-butane, poly(propyl methacrylate)-propylene, poly(propyl methacrylate)-1-butene, and poly(propyl methacrylate)-CHClF_2 systems were dissolved at the pressures less than 2,390 bar, below 2,100 bar, below 570 bar, below 310 bar, below 300 bar, and below 170 bar, respectively. The temperature range shows from 40 to 186℃. The phase behavior of between binary poly(propyl acrylate)-CO_2 and poly(propyl acrylate)-dimethyl ether system were measured from upper critical solution temperature region to lower critical solution temperature region with added dimethyl ether concentrations of 5, 15 and 50 wt%.

남북한 관계에서 한민족 범주복잡성과 한민족동일시가 외집단 관용 및 집단 간 통합지향 행동의도에 미치는 효과

이하연,최훈석,노중현,도은별,한지민 한국사회및성격심리학회 2023 한국심리학회지 사회 및 성격 Vol.37 No.2

The current study examined the interplay between superordinate category (i. e., ‘Ethnic Han’) complexity and superordinate ingroup identification on outgroup (North Koreans) tolerance and support for intergroup integration amongst South Koreans. Category complexity reflects the extent to which the category contains distinctive and equally representative subgroups. We hypothesized that individuals’ superordinate ingroup identification positively predicts outgroup tolerance when the superordinate category is perceived as complex rather than simple in its representational structure. In addition, we expected that this effect would positively predict outgroup tolerance, which in turn, positively predicts behavioral intentions for intergroup integration. In a laboratory experiment involving South Korean undergraduates (N = 124), we measured participants’ level of identification with the superordinate category and manipulated the superordinate category complexity (high vs. low). Results indicated, as expected, that in the high superordinate category complexity condition, superordinate ingroup identification positively predicted outgroup tolerance. When category complexity was low, there was no significant relationship between superordinate ingroup identification and outgroup tolerance. Further, outgroup tolerance mediated the interaction effect between the superordinate category complexity and the ingroup identification on behavioral intentions for intergroup integration. We discussed the role of superordinate category complexity and superordinate ingroup identification in establishing harmonious and integrative subgroup relationships between the two Koreas. 본 연구는 남북한 관계에서 공동 상위범주인 한민족의 범주복잡성이 낮거나 높다고 지각할 때 한민족동일시가 북한에 대한 관용과 남북한 통합지향 행동의도에 미치는 효과를 검증하였다. 높은 한민족 범주복잡성은 한민족이 다양한 속성을 지닌 하위집단들로 구성되었다는 지각을 의미한다. 본 연구에서는 남한 사람들이 한민족을 남북한뿐만 아니라 여러 하위집단(예: 한국계 외국인, 재외국민 등)으로 구성된다고 지각할 때 한민족동일시가 외집단인 북한에 대한 관용을 매개로 남북한 통합지향 행동의도를 정적으로 예측한다는 가설을 실험을 통해 검증하였다. 실험에서는 남한 대학생(N = 124)을 대상으로 한민족동일시 수준을 측정하고 한민족의 범주복잡성(높음 vs. 낮음)을 조작하였다. 실험 결과, 한민족 범주복잡성이 높은 조건에서 참가자들의 한민족동일시 수준이 높을수록 북한에 대한 관용 수준이 높았다. 반면 한민족 범주복잡성이 낮은 조건에서는 한민족동일시가 북한에 대한 관용을 예측하지 못했다. 그리고 한민족 범주복잡성과 한민족동일시의 상호작용이 북한에 대한 관용을 매개로 남북한 통합지향 행동의도를 정적으로 예측하였다. 본 연구가 남북관계에 관한 심리학 연구에 시사하는 바와 장래 연구과제를 논의하였다.

집단 내 공감 구조의 효과

이하연,최훈석 한국사회및성격심리학회 2014 한국심리학회지 사회 및 성격 Vol.28 No.3

The present research investigated how empathy structures in task groups affect group members' task-focus, perceived entitativity and cohesion. Empathy structures in task groups were defined at the dyadic level, and three forms of empathy structures were investigated: empathy-balanced, empathy-imbalanced, non-empathy-balanced. It was hypothesized that in the two balanced structures, groups would experience higher levels of task-focus than in the imbalanced structure. In addition, empathy-balanced groups were expected to perceive higher levels of group entitativity and experience higher cohesion than other groups. In Study 1, we used a scenario method and manipulated three types of empathy structure. Results showed that the perceived entitativity was high in the empathy-balance condition, empathy-imbalance condition, and non-empathy-balance condition, in order. We found the same pattern of result on cohesion. We conducted Study 2 using bona-fide groups consists of Korean college students and replicated the findings of Study 2. In addition, groups with a structure of non-empathy-balance reported higher levels of task-focus than did groups with other types of empathy structures. Limitations and implications of these findings and directions for future research are discussed. 두 편의 연구를 통해서 집단에서 구성원들 간의 공감 구조(공감균형/공감불균형/비공감균형)에 따른 집단과제 몰입, 집단 실체성 지각 및 응집성을 알아보았다. 연구 1에서는 시나리오를 통해 세 명의 집단 구성원들 간에 공감균형, 공감불균형, 비공감균형이 존재하는 상황을 제시하여 집단 내 공감 구조를 조작했다. 연구 결과, 집단 실체성 지각과 응집성은 공감균형 조건에서 가장 높고 공감불균형 조건과 비공감균형 조건 순으로 낮았다. 구성원들의 집단과제 몰입 수준에서는 연구 가설과 일관된 결과가 발견되지 않았다. 연구 2에서는 대학생들로 구성된 현장집단을 대상으로 다양한 집단 상호공감 구조를 확인했으며, 집단 실체성 지각과 응집성 경험에서 연구 1의 결과가 반복검증 되었다. 또한 집단과제 몰입은 비공감균형 조건이 가장 높고 공감불균형과 공감균형 조건 순으로 낮게 나타났다. 집단의 핵심 기능에 대해 집단 상호공감 구조가 미치는 영향과 공감의 사회적 역동을 중심으로 본 연구의 시사점과 장래 연구 방향을 논의했다.

생활인프라 공급계획을 위한 접근성 평가 방법

이하연,김성표,강상혁 한국건설관리학회 2020 한국건설관리학회 논문집 Vol.21 No.1

Recently, interest and financial investment in community infrastructure have been growing. Accordingly, Korean Ministry of Land, Infrastructure and Transport suggested a standard for community infrastructure planning. The standard was based on time distance which represents citizens’ accessibility to infrastructure facilities. This paper presents a method to use the navigation application programming interface (API) to calculate travel time. Buffer analysis using Euclidean distance has been widely used so far to evaluate accessibility. However, this method has limitation in that it does not reflect situations in the real world such as crosswalks and slope ways. The infrastructure accessibility indices of local towns in Yeonsu-gu, Incheon were computed based on the time obtained by navigation API. Also, Yeonsu-gu was spatially analyzed to reveal the resident units that are marginalized from community infrastructure facilities. Using navigation API enables to compute realistic accessibility indices and to find unbenefitted residential areas. The method presented in this paper can help community infrastructure planners for their facility spatial plan and budget distribution.

Compression of the Main Pancreatic Duct by the Intrapancreatic-Replaced Common Hepatic Artery

이하연,하홍일,김민정,임현경 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.3

We describe a unique case of a patient who presented with a linear, transverse, and incidentally-detected main pancreatic duct dilatation that was caused by the intrapancreatic-replaced common hepatic artery, detected on the MDCT, MRCP and endoscopic retrograde cholangiopancreatography. We believe this case to be the first of its kind reported in the literature.

아버지-유아의 거친신체놀이에서 아버지의 부모성찰력, 신체활동성, 언어 소통 의도가 유아의 놀이 참여에 미치는 영향

이하연,김명순 한국유아교육학회 2022 정기학술대회 논문집 Vol.2022 No.2

The Situation of Life-Sustaining Treatment One Year After Enforcement of the Act on Decisions on Life-Sustaining Treatment for Patients at the End-of-Life in Korea: Data of National Agency for Management of Life-Sustaining Treatment

이하연,김화정,권정혜,백선경,원영웅,김유정,백수진,류혜원 대한암학회 2021 Cancer Research and Treatment Vol.53 No.4

Purpose The “Act on Hospice and Palliative Care and Decisions on Life-Sustaining Treatment for Patients at the End-of-Life” was enacted on February 3, 2016 and went into effect on February 4, 2018 in Korea. This study reviewed the first year of determination to life-sustaining treatment (LST) through data analysis of the National Agency for Management of Life-Sustaining Treatment. Materials and Methods The National Agency for Management of LST provided data between February 4, 2018 and January 31, 2019 anonymously from 33,549 patients. According to the forms patients were defined as either elf-determinants or family-determinants. Results The median age of the patient was 73 and the majority was male (59.9%). Cancer patients were 59% and self-determinants were 32.1%. Cancer patients had a higher rate of self-determinants than non-cancer (47.3% vs. 10.1%). Plan for hospice service was high in cancer patients among self-determinants (81.0% vs. 37.5%, p < 0.001). In comparison to family-determinants, self-determinants were younger (median age, 67 years vs. 75 years; p < 0.001) and had more cancer diagnosis (87.1% vs. 45.9%, p < 0.001). Decision of withholding or withdrawing of LSTs in cancer patients was higher than non-cancer patients in four items. Conclusion Cancer patients had a higher rate in self-determination and withholding or withdrawing of LSTs than non-cancer patients. Continued revision of the law and education of the public will be able to promote withdrawing or withholding the futile LSTs in patients at end-of-life. Further study following the revision of the law should be evaluated to change of end-of-life care.

집단 창의성에서 집단주의 가치와 독립적 자기관의 상승효과: 현장 집단 연구

이하연,최훈석 한국사회및성격심리학회 2019 한국심리학회지 사회 및 성격 Vol.33 No.4

The present study reports data from a field experiment that tested a synergy model of collectivistic value orientation and independent self-representation on group creativity(Choi, Cho, Seo, & Bechtoldt, 2018). Participants were recruited from a university-wide learning camp on teamwork. We induced a collectivistic value orientation as part of a teamwork activity in all groups. With this, we primed either independent or interdependent self-representation in the two experimental conditions. We also included a control condition where there was no manipulation of self-representation. Using an interactive group brainstorming task, we found support for the hypothesized synergy effect in groups where participants were randomly assigned to the work unit. No significant effects were found in groups of friends. Results also suggest that the observed synergy effect is due in part to the creativity-enhancing nature of independent self-representation, rather than detrimental effects of interdependent self-representation on group creativity. We discuss implications of these findings vis-à-vis previous research on the link between individualism-collectivism and group creativity. We also discuss limitations and future directions of this research. 본 연구는 집단주의 가치지향성과 독립적 자기표상의 상승효과 모형(Choi, Cho, Seo, & Bechtoldt, 2018)을 바탕으로, 현장 집단에서 집단 창의성에 대한 모형의 개입효과성을 검증하였다. 대학 주관으로 진행된 학습캠프에 참여한 집단들에서 집단주의 가치지향성을 조작한 후, 독립적 또는 상호의존적 자기표상을 활성화하거나 활성화하지 않는(통제조건) 절차를 사용하여 총 세 개 조건에서 집단이 생산한 아이디어의 창의성을 비교하였다. 연구 결과, 구성원들에게 집단주의 가치지향성만 조작했거나 집단주의 가치지향성과 상호의존적 자기표상을 조합한 조건보다, 집단주의 가치지향성과 독립적 자기표상을 조합한 조건에서 집단 창의성이 높았다. 이 결과를 서구에서 보고된 관련 연구들과 비교하고, 개인주의-집단주의와 집단 창의성의 관계를 체계적으로 분석하기 위한 장래 연구 방향을 논의하였다.

한국인의 이중 사회정체성과 내집단 투사, 남북한 통일태도 간 관계

이하연,권영미,서정길,박주화,최훈석 한국사회및성격심리학회 2022 한국심리학회지 사회 및 성격 Vol.36 No.4

The present study investigated the relationship between dual social identity, ingroup projection, and attitudes toward the unification of Korea. We hypothesized that South Koreans who are characterized as having dual social identity, namely, those who identify themselves strongly with both the superordinate category (i.e., ethnic identity) and the subordinate category (i.e., national identity), would show high levels of ingroup projection, which in turn would predict negatively their attitudes toward unification of North and South Korea. In addition, we examined the moderating effect of the centrality of the superordinate and the subgroup identity on the relationship between dual identity and ingroup projection. Data from a stratified sample of South Korean adults (N = 1,600) revealed that, as expected, ingroup projection negatively mediated the relationship between dual identity and attitudes toward the unification of Korea. Importantly, the relationship between dual identity and ingroup projection was attenuated among those who perceived their superordinate identity as a more central aspect of themselves than their subgroup identity. We discuss the implications of our findings for the role of social identity in social integration research in the context of the unification of Korea. 본 연구는 상위수준 한민족 범주와 하위수준 국가(남북한) 범주로 구분되는 층소된 사회정체성 구조에서 상위범주-하위범주 동일시 수준 간 상호작용과 내집단 투사, 남북한 통일에 대한 태도 간의 관계를 조사하였다. 한국인들이 남북한을 포섭하는 공동 상위범주인 한민족에 강하게 동일시하더라도 동시에 하위범주인 남한에 강하게 동일시할 경우, 남한이 북한보다 한민족의 전형적이고 필수적인 집단이라고 지각하는 내집단 투사가 발생하며, 내집단 투사는 통일태도를 부적으로 예측할 것으로 예상했다. 이에 더해 내집단 투사를 완화하는 기제로 상위범주와 하위범주 정체성 중심성의 역할을 검증했다. 인구비례할당표집으로 수집된 한국 거주 성인 1,600명의 자료를 분석한 결과, 가설과 일관되게 남한사람들이 한민족과 남한에 동시에 강하게 동일시할수록(즉, 이중 정체성이 우세할수록) 내집단 투사 수준이 높았으며, 이중 정체성은 내집단 투사를 매개로 통일태도를 부적으로 예측했다. 또한, 이중 정체성이 내집단 투사를 예측하는 효과는 구성원들이 하위범주 정체성을 상위범주 정체성보다 중시할 경우 유의했고, 하위범주 정체성을 상대적으로 덜 중시할 경우에는 유의하지 않았다. 이러한 결과는 남북한 관계에 관한 심리학 연구에서 층소된 사회정체성의 효과를 체계적으로 검증해야 하며 이를 반영하는 개입 전략이 필요함을 시사한다.

아임계수 추출 기술을 이용한 흑후추 추출물의 유효성분 및 산화방지 평가

이하연,고민정 한국식품과학회 2023 한국식품과학회지 Vol.55 No.2

Subcritical water extraction (SWE) is an eco-friendly extraction technique using only water as the solvent. The extraction of less-polar compounds is possible by altering the temperature-dependent dielectric constant of water. This study analyzed the concentration of piperine, total phenolics, total flavonoids, and antioxidant activities in black pepper extracts obtained via subcritical water extraction. The piperine concentration (6.63±0.65 mg/g) was maximized with extraction at 200oC for 20 min. The black pepper extraction via the SWE method demonstrated a higher piperine yield than that using extraction solvents (such as ethanol) and hot water. The total phenolics (85.39±2.16 mg gallic acid equivalent/ g), total flavonoids (18.27±0.18 mg quercetin equivalent/g), and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) free radical scavenging activity (97.38±0.52%) were maximal at extraction conditions of 200oC and 20 min. In conclusion, the SWE technique could be an alternative to the method using organic solvents for extracting bioactive compounds.