• Journal of the Korean Chemical Society
• /
• v.38 no.8
• /
• pp.562-569
• /
• 1994

The retention data of twenty one monosubstituted phenols in the eluent systems containing 30∼70% of methanol or acetonitrile as organic modifiers, on $ C_{18}$ and Phenyl columns were collected to investigate the effect of the substituted groups on the retention of phenols. The capacity factors of the solutes except amino phenols are greater on $ C_{18}$ than on Phenyl column. And all the solutes have shown greater capacity factors in methanol-water than that in acetonitrile-water as a mobile phase. Generally the elution order between meta and para isomers of monosubstituted phenols in consistent (p < m) regardless of the polarity of the substituted group. But the elution order between ortho and meta isomers of phenol varies with regard to the polarity of the substituted group. The retention of the monosubstituted phenols has been influenced by the interaction between the solute and unreacted silanol of columns as well as the interaction between the solute and $ C_{18}$ or phenyl group of columns. And then, the effect of unreacted silanol on the retention of the monosubstituted phenols is greater on $ C_{18}$ than on Phenyl column. And the greater hydrogen bonding acceptor basicity(${\beta}$) of the substituted group is, the greater this effect is. The relationship between the retention of the monosubstituted phenols and their parameters such as van der Waals volume(VWV) and hydrogen bonding acceptor basicity(${\beta}$) has been investigated. The good linearity has been observed in the plot log k' vs. (1.01VWV/100-1.84${\beta}$). In consequence, the retention of the monosubstituted phenols on $ C_{18}$ and Phenyl columns can be easily predicted by the parameter (1.01VWV/100-1.84${\beta}$).

• The Journal of the Korea Contents Association
• /
• v.19 no.7
• /
• pp.467-477
• /
• 2019

The purpose of this study was to investigate the relationship among job stress, nursing organizational culture, emotional exhaustion for the clinical nurses and the influencing factors on retention intention of nurses in a general hospital. This study used 209 questionnaires from nurses in B city to collect data from November 1, 2017 to December 15. Data were analyzed by SPSS 20.0 program using descriptive statistics, t-test, ANOVA, Scheffe's test, Pearson's correlation coefficient and Stepwise Multiple Regression. The results are as follows; The participants' job stress level was 3.48(${\pm}0.46$), nursing organizational culture level was 3.13(${\pm}0.31$), emotional exhaustion level was 3.95(${\pm}1.18$) and retention intention level was 4.54(${\pm}1.29$). Retention intention was a significant correlated between job stress(r=-21, p=.003), nursing organizational culture(r=.25, p<.001), emotional exhaustion(r=-40, p<.001). According to the result of multiple regression analysis, The significant factors influencing retention intention of clinical nurses were emotional exhaustion, nursing organizational culture, total career and age. it was explained by 23.7%. Based on these findings, in order to increase the level of retention intention, it is necessary to develop a variety of programs to reduce emotional exhaustion, as well as a plan to help them recognize a positive nursing organization culture, and to fine ways to manage long-term careers.

• The Journal of Internal Korean Medicine
• /
• v.40 no.3
• /
• pp.390-408
• /
• 2019

Objectives: Several pattern diagnosis questionnaires have been developed to objectify the process of pattern diagnosis in Korean medicine. In this context, this study aimed to develop a food retention questionnaire for functional dyspepsia (FRQ-FD) by modifying the previously developed food retention questionnaire (FRQ) and to verify its reliability and validity. Furthermore, this study aimed to identify the optimal cut-off value of the FRQ-FD for standardization and use in clinical situations. Methods: To develop the FRQ-FD, we extracted the major symptoms of food retention pattern for functional dyspepsia from Chinese/Korean medicine textbooks and requested an importance survey from experts using the Delphi method. The first draft of the FRQ-FD was composed of 25 questions comprising 8 questions from the textbooks and the Delphi method and 17 questions from the FRQ already developed in 2013. To analyze its reliability, validity, and optimal cut-off value, 60 subjects were enrolled in this study from June 25 to August 13, 2018. Thirty patients were diagnosed as both functional dyspepsia and food retention pattern, and 30 healthy participants were not. All participants were requested to fill up the FRQ-FD, Stomach Qi Deficiency Questionnaire (SQDQ), Scale for Stomach Qi Deficiency pattern (SSQD), visual analog scale (VAS) for dyspepsia, Nepean Dyspepsia Index-Korean version (NDI-K), and functional dyspepsia-related quality of life (FD-QoL). Results: No statistically significant differences were found in sex distribution, age, and body mass index between the patient group and the control group. As five questions affected the reliability negatively and three questions affected the clinical validity negatively, we decided to exclude the eight questions upon further investigation. The Cronbach's ${\alpha}$ coefficient of the revised FRQ-FD (17 items) was 0.899, and its clinical validity was verified. Construct validity was analyzed by factor analysis and produced five factors. Statistically significant positive correlations were found between the revised FRQ-FD and the other dyspepsia scales, namely, SQDQ, SSQD, VAS, NDI-K, and FD-QoL. VAS and NDI-K especially had strong positive correlations with FRQ-FD. Conclusions: The FRQ-FD developed in this study can provide fundamental reliability and validity for a pattern diagnosis questionnaire. FRQ-FD can help to diagnose food retention pattern in functional dyspepsia patients. Further studies are required to inspect several statistical factors.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.401-411
• /
• 2006

The cationic chitosan is prepared in this paper. This kind of cationic chitosan is a good retention aid for bleached hardwood pulp, the filler retention increased by 33.0% when the cationic chitosan (DS=1.27) dosage was 0.05%. Because many of the materials used in papermaking process are excellent microbiological nutrients, these nutrients will result in the growth of bacteria; uncontrolled growth of bacteria and fungi in the papermaking process adversely affects machine runnability. According to the standard methods of microbe growth inhibition test, cell counting was conducted after proper cultivated time. This paper explored the factors that affecting the cationic chitosan's antibacterial effect.

• The Korean Journal of Ceramics
• /
• v.4 no.3
• /
• pp.240-244
• /
• 1998

The analytical method was developed to calculate efficiency of densifying carbon/carbon (C/C) composites using coal tar pitch as a matrix precursor at each cyle. Three factors were defined in analyzing the densification process: impregnation efficiency, retention efficiency, and overall densification efficiency. The relationships developed were applied to the experimental results for three densification cycles of C/C composites with pitches as an impregnant to evaluate the factors which may depend on the impregnant and on the route of carbonization. The impregnation efficiency increased with the repeated process cycles whereas the retention efficiency decreased irrespective of the impregnant and carbonization route. Carbonization route P+A+G, in which pressure carbonizationl (P) and graphitization (G) were done before after atmospheric pressure carboniztion (A) respectively, using impregnant of high carbon yields was the most effective method in densifying C/C composites.

• Architectural research
• /
• v.4 no.1
• /
• pp.45-52
• /
• 2002

Selection procedures of earth retention systems are increasingly complex and directly related to the serviceability of the retaining structure selection systems since significant changes in earth retention technology motivates the review of design, and selection processes of earth retaining structures. Collection and classification of retaining structure selection knowledge are key issues because two expert groups, geotechnical and structural engineers, are mainly involved in the retaining structure selection. The course of natural tendency of expert knowledge are investigated considering the decision factors. The decision factors for selecting retaining structures are divided into four categories: application of the structure, and spatial, behavior, and economic constraints.

• Journal of Agricultural Extension & Community Development
• /
• v.18 no.3
• /
• pp.409-434
• /
• 2011

The main purpose of this study was to examine the effects of servicescape on post evaluation of hospitality industry in Gyeongnam. Customers of deluxe hotels in Gyeongnam were selected for a questionnaire survey. To achieve the study objective, 253 valid questionnaires were statistically analyzed, using frequency analysis, factor, reliability analysis and regression analysis. The results of the multiple regression analysis indicated that five of servicescape factors had significant impact on customer satisfaction and customer retention. The servicescape factors partially exerted a positive influence on word-of-mouth intention. The result of the simple regression analysis also indicated that the customer satisfaction had very significant impact on customer retention and word-of-mouth intention.

• Journal of Korean society of Dental Hygiene
• /
• v.21 no.2
• /
• pp.159-170
• /
• 2021

Objectives: This study aimed to investigate factors for retention intention among long-term employed dental hygienists and to provide basic data for improving the long-term service (working) environment. Methods: A total of 202 dental hygienists with more than five years' work experience at dental hospitals and clinics located in Seoul, Gwangju, and Jeonnam Province, South Korea, were surveyed. The data were analyzed for each factor using exploratory factor analysis, and differences according to the general characteristics of the participants were analyzed using an independent sample t-test, one-way ANOVA and a hierarchical multiple regression analysis. Results: At the current workplace, a better working environment, and higher job satisfaction were associated with higher retention intention. However, lower professionalism in dental hygiene as a subdomain of the professional self-concept domain was associated with higher retention intention. Conclusions: To increase retention intention among dental hygienists, it is necessary to improve the working environment in which dental hygienists can perform professional roles and seek ways to establish their identity as professionals in dental healthcare settings.

• Biomolecules & Therapeutics
• /
• v.30 no.6
• /
• pp.562-569
• /
• 2022

Etretinate, an acitretin metabolite, has a long retention duration in adipose tissues with a teratogenic potential. FDA advises a contraceptive period of at least three years after discontinuing acitretin. However, the effect of accumulated etretinate in adipose tissues on fetus is unknown. Although the teratogenic threshold for serum concentration of etretinate has been presented as higher than 2 ng/mL, that of acitretin is unknown. To examine factors affecting body retention of acitretin and etretinate, effects of acitretin dosage, acitretin-taking duration, elapsed time after stopping acitretin, age, sex, concomitant alcohol consumption, and foods and supplements rich in vitamin A intake on serum concentrations of acitretin and etretinate were analyzed in 14 acitretin-taken patients and 58 controls without taking acitretin or etretinate. Serum concentrations of acitretin, but not etretinate, tended to be inversely related to the discontinuation duration. They were also related to old age. Different from a published result that alcohol consumption could promote the metabolism of acitretin into etretinate, alcohol intake did not affect serum concentrations of etretinate. Unexpectedly, more frequent intake of vitamin A or provitamin A-rich food and supplements was associated with higher serum acitretin, whereas less frequent intake of vitamin A or provitamin A-rich food and supplements was associated with higher serum levels of etretinate in acitretin-taken patients. Despite preliminary data, inter-individual variations in serum retention of etretinate suggest the necessity of further research before applying the same guidelines to everyone to minimize unnecessary contraception.

• Journal of Korean society of Dental Hygiene
• /
• v.22 no.3
• /
• pp.199-207
• /
• 2022

Objectives: The objectives of this study were to find the influential factors of dental hygienists' work environment and level of perception of rights on their retention intention, and to provide basic data for protecting their rights and interests and improving their employment rate. Methods: From June 6 to July 24, 2021, a questionnaire survey was conducted among 214 dental hygienists via an online link. After questionnaire collection, IBM SPSS program (ver. 21.0; IBM Corp., Armonk, NY, USA) was used to conduct frequency analysis, t-test, one-way ANOVA and multiple regression analysis. Results: The significant and positive influential factors of dental hygienists' retention intention were married individuals (p=0.022), fewer working hours (p<0.001, p=0.007), good work environment (p=0.002), higher wages (p<0.001, p<0.001), higher education (p=0.032), and perception of rights in a mid-level (p=0.038). Conclusions: It is necessary to consider wages and welfare equivalent to dental hygienists' work intensity and workload. By regularly educating dental hygienists to increase their perception of rights, expanding an opportunity of participation, and improving their work environment, it will be possible to increase their retention intention and efficiently establish manpower in dental clinics.