Kiho Park

Quantitative estimation of internal concentration polarization in a spiral wound forward osmosis membrane module compared to a flat sheet membrane module

Internal concentration polarization (ICP) within the forward osmosis (FO) membrane affects the reduction of driving force. The magnitude of ICP in the FO membrane was investigated experimentally by measuring water flux in both spiral wound (SW) and flat-sheet (FS) modules with different draw solutions (sodium chloride, sodium sulfate, and disodium phosphate). The FO SW module always shows inferior water flux performance to the FO FS module. The water flux in the FO SW module can be easily estimated by just changing structure parameter. The estimated structure parameter in the FO SW module is 9.1325×10−4 m, which is quite higher than 4.2×10−4 m in the FO FS module. The increase of the structure parameter is attributed to the bending of the FO membrane in the SW module. It can be concluded that a module design such like SW type is not suitable for the FO process.

Cost-based analysis about a newly designed two-staged reverse osmosis process with draw solute

Abstract Draw solution assisted reverse osmosis (DSARO) process is suggested and mathematically modelled in this study. The main concept of the process is osmotic pressure reduction in the RO process by utilizing draw solution which has lower concentration than seawater. Since the pressure requirement of the DSARO process is in the range of BWRO process, the plant capital cost data in BWRO process can be used for cost estimation model. The cost estimation results shows that the specific water cost in DSARO process is more than 10% lower than that of conventional RO process. So the DSARO process can be economically feasible.

Cognitive Remediation in Middle-Aged or Older Inpatients with Chronic Schizophrenia: A Randomized Controlled Trial in Korea

Background: Accumulating evidence indicates that cognitive remediation (CR) is effective for improving various cognitive deficits in adult patients with schizophrenia. Although reports of brain plasticity in older adults and the service needs for chronic patients with schizophrenia are increasing, very few randomized controlled trials of CR have been conducted in middle-aged or older inpatients with chronic schizophrenia. We investigated the efficacy of individualized CR on the cognitive impairments of middle-aged or older inpatients with chronic schizophrenia within the context of comprehensive psychiatric rehabilitation (PR) by comparing the results obtained with PR only and treatment as usual (TAU). Method: Fifty-seven middle-aged and older individuals with chronic schizophrenia and mild to moderate cognitive deficits were enrolled. Thirty-eight who were undergoing PR were randomly assigned to CR + PR (N = 19) or PR-only (N = 19) groups. Nineteen participants who were undergoing TAU without CR or PR were evaluated pre- and post-treatment. Results: CR was easily provided and well received (drop-out rates = 5.3%) by middle-aged or older psychiatric inpatients. Compared to the PR-Only or TAU patients, patients in the CR + PR group showed greater improvement in executive functioning. Compared to TAU patients, CR + PR and PR-only patients showed greater improvement in logical memory. More patients in the CR + PR group improved clinically significantly in executive functioning and logical memory, compared with the PR-only and TAU patients. Conclusions: These results suggested that CR improved some cognitive deficits in middle-aged or older inpatients with chronic schizophrenia and that it was effective as an adjunctive treatment to the usual PR services provided in inpatient settings. Clinical Registration: KCT0002609

Measuring theory of mind in schizophrenia research: Cross-cultural validation

Theory of mind (ToM) is the ability to understand mental states of others and it is crucial for building sensitivity to other persons or events. Measuring ToM is important for understanding and rehabilitating social cognitive impairments in persons with schizophrenia. The Social Attribution Task-Multiple Choice (SAT-MC) has been successfully employed to measure ToM between individuals with schizophrenia (SZ) and healthy controls (HC) in North America. Given that the SAT-MC uses geometric shapes, is nonverbal and less culturally loaded than other social cognition measures, it may serve for measuring ToM in schizophrenia across cultures. A total of 120 participants (30 per group; Korean SZ; Korean HC; North American SZ; North American HC) were selected from existing databases to examine the reliability and validity of the SAT-MC. Internal consistency, factor structure, measurement invariance, discriminant validity, and convergent/divergent validity were examined. The SAT-MC had good internal consistency regardless of the clinical and cultural group as evidence by Cronbachs α ≥ 0.78 in all groups. Confirmatory factor analysis confirmed the one-factor model with a good model fit (χ2 = 188.122, TLI = 0.958, CFI = 0.963, RMSEA = 0.045). The SAT-MC was sensitive to detect individual differences in ToM of SZ and HC, regardless of culture (p < 0.001), and significantly correlated with other social cognition tasks (Hinting and Reading the Mind in the Eyes Test) among Korean and North American patients. The SAT-MC is a reliable measure for evaluating ToM in both Koreans and North Americans with or without schizophrenia, supporting its potential utility in diverse language and cultures for schizophrenia research.

F55. EFFICACY OF COMPUTER ASSISTED COGNITIVE REMEDIATION IN MID-AGED AND OLDER INPATIENTS WITH CHRONIC SCHIZOPHRENIA IN KOREA

Abstract Background Accumulating evidence indicates that cognitive remediation(CR) is effective for improving various cognitive deficits in adult patients with schizophrenia. Although reports of brain plasticity in older adults and the service needs of chronic mid-aged and older patients with schizophrenia are increasing, very few randomized controlled trials of CR have been conducted in mid-aged and older inpatients with schizophrenia. We investigated the efficacy of individualized CR on the cognitive impairments of mid-aged and older inpatients with schizophrenia within the context of comprehensive psychiatric rehabilitation(PR) by comparing the results obtained with PR only and treatment as usual(TAU). Methods Fifty-seven mid-aged and older individuals with schizophrenia (age mean: 50.07 sd: 6.01) and mild to moderate cognitive deficits were enrolled. All participants stayed in long-stay closed ward hospital. Thirty-eight who were undergoing PR were randomly assigned to CR + PR (N = 19) or PR-only (N = 19) groups. For PR groups (CR+PR group and PR only group) received comprehensive inpatient PR, including optimal pharmacotherapy, vocational rehabilitation, social skills training, daily living skills training, illness management, independent living skills training, and patient empowerment program. For CR+PR group, CR treatment was provided adjunctive to their PR program described above. CR treatment consisted of 24 sessions that occurred twice a week for 1 h/session for over 3 months. The PSSCogRehab software program which was translated in Korea and Lumosity cognitive enhancement game were utilized for CR training. Participants in PR-only group were also received same psychiatric rehabilitation program, that specific training on neurocognitive functioning was not included. Nineteen participants who were undergoing TAU without CR or PR were evaluated pre- and post-treatment. Results No group differences were found in key demographical variables, premorbid IQ, psychiatric characteristics or baseline neurocognitive functioning at the pre-treatment. CR was easily provided and well received (drop-out rates = 5.3%) by mid-aged and older psychiatric inpatients. the CR + PR group showed greater post-treatment performance on both WCST total errors and WCST %CL compared with the PR-only group (WCST total errors: mean difference = 12.28, p = 0.026; WCST %CL: mean difference = 16.47, p = 0.017) and TAU group (WCST total errors: mean difference = 14.00, p = 0.015; WCST %CL: mean difference = 16.24, p = 0.023). However, no group differences were found on WCST total errors and WCST %CL between the PR-only and TAU groups. No group differences were found for processing speed, attention, verbal working memory or cognitive flexibility. Discussion The results of the current study partially supported our primary hypothesis. Specifically, compared with the PR-only and TAU groups, the CR + PR group showed greater improvement in executive functioning. Importantly, the reliable change index(RCI) indicated that more participants in the CR + PR group had clinically meaningful improvements in LM and executive functioning compared with participants in the PR-only and TAU groups. These results suggested that CR improved some cognitive deficits in mid-aged and older long-stay inpatients with schizophrenia and that it was effective as an adjunctive treatment to the usual PR services provided in inpatient settings.

Paranoia Symptoms Moderate the Impact of Emotional Context Processing on Community Functioning of Individuals with Schizophrenia

This study examined whether better emotional context processing is associated with better community functioning among persons with schizophrenia, and whether the relationship between the two variables is moderated by level of paranoid symptoms. The Brief Psychiatric Rating Scale—Expanded Version, Emotional Context Processing Scale, and Multnomah Community Ability Scale were administered to 39 community-dwelling participants with schizophrenia or schizoaffective disorder. Emotional context processing had a small-to-moderate association with community functioning. However, the association between emotional context processing and community functioning was moderated by level of paranoid symptoms. Emotional context processing in participants with mild paranoid symptoms was strongly associated with better community functioning, whereas emotional context processing in those with severe paranoid symptoms was not. Emotional context processing and the degree of paranoia should be considered in treatment plans designed to enhance the community functioning of individuals with schizophrenia to help them improve their understanding of social situations.

Development of The Korean Screening Tool for Depressive Disorders : A Preliminary Study

우울장애를 선별하는 신뢰롭고 타당한 선별도구를 개발하는 것은 잠재적인 위험군이나 발병 초기단계 있는 사람에게 최적의 치료를 제공하기 위한 가장 첫 번째 과제이다. 이는 현대 정신건강 정책이 정신질환의 예방과 조기개입을 강조하는 흐름과도 일치한다. 현재까지 우울장애를 선별하는 다수의 도구들이 개발되어 왔으나, 해외 저작권 지불의 문제를 해결하고, 우울의 하위영역은 물론 자살위험과 조증, 불안 및 신체증상을 포괄하며, 국가 연구 프로젝트와 병원 및 다양한 임상현장에서 활용할 수 있는 간결한 형태의 한국형 우울장애 선별도구를 개발하는 것이 과제로 남아있다. 본 연구에서는 현재까지 개발된 우울장애 선별도구를 체계적으로 개관하여 각 선별도구의 강점과 약점을 분석하였으며 이를 바탕으로 새롭게 개발할 한국형 우울장애 선별도구(Korean Screening Tool for Depressive Disorders, K-DEP)의 이론적 기초를 요약하였다. 임상심리, 정신의학, 심리측정 전문가 그룹으로 구성된 다학제 연구팀과 전문가 자문위원회와 함께 한국형 우울장애 선별도구를 개발하는 과정을 요약하였으며, 이 과정에서 개발된 총 383문항의 예비 문항을 소개하고, 153명의 참여자에게 실시한 예비 분석결과를 제시하였다. 마지막으로 앞으로 실시될 한국형 우울장애 선별도구 개발 프로젝트의 차기 단계 과정과 고려사항들을 논의하였다.

A modified scaled variable reduced coordinate (SVRC)-quantitative structure property relationship (QSPR) model for predicting liquid viscosity of pure organic compounds

Liquid viscosity is an important physical property utilized in engineering designs for transportation and processing of fluids. However, the measurement of liquid viscosity is not always easy when the materials have toxicity and instability. In this study, a modified scaled variable reduced coordinate (SVRC)-quantitative structure property relationship (QSPR) model is suggested and analyzed in terms of its performance of prediction for liquid viscosity compared to the conventional SVRC-QSPR model and the other methods. The modification was conducted by changing the initial point from triple point to ambient temperature (293 K), and assuming that the liquid viscosity at critical temperature is 0 cP. The results reveal that the prediction performance of the modified SVRC-QSPR model is comparable to the other methods as showing 7.90% of mean absolute percentage error (MAPE) and 0.9838 of R2. In terms of both the number of components and the performance of prediction, the modified SVRC-QSPR model is superior to the conventional SVRC-QSPR model. Also, the applicability of the model is improved since the condition of the end points of the modified model is not so restrictive as the conventional SVRC-QSPR model.

Economic Evaluation of Hybrid FO-crystallization-RO Desalination Process

Abstract The economic feasibility of FO, crystallization and RO hybrid process was analysed on the view of specific water cost. Selecting appropriate draw solutes for the hybrid process, cost evaluation model was developed considering capital and operating cost. To solve MINLP problem efficiently, the problem is divided into FO, RO and crystallization. Each specific water production cost was calculated in FO and RO individually, and the costs of them are fitted as functions of recoveries. Then, the overall specific water cost can be calculated as a function of recoveries of FO and RO. Then the MINLP problem becomes an ordinary NLP problem. Considering three different FO membrane, the minimum specific water cost is 0.5727

Feasibility study of solvent recycle process in spin-on hard mask material manufacturing system

/m 3 when mLbL-10 membrane as FO process and disodium phosphate as draw solute. Comparing 0.6452