• Clean Technology
• /
• v.14 no.2
• /
• pp.95-102
• /
• 2008

In order to choose alternative environmental-friendly cleaning agents, it is very important in the present point that the systematic selection procedures should be introduced and applied to the industry through the evaluation of their cleaning ability, environmental characteristics, and economical factors, and that the objective and effective evaluation methods of cleanliness should be established for the industry. Thus, a novel cleaning evaluation method utilizing optically stimulated electron emission (OSEE) among various methods of cleaning ability was studied in this study. The contaminants used in this cleaning experiments were flux, solder, grease, cutting oil, and mixed soil of 35% grease and 65% cutting oil. The cleaning agents developed or prepared in our laboratory were employed and their cleaning ability were comparatively evaluated by the OSEE, gravimetry and contact angle methods. The experimental results in this work showed that flux cleaning efficiency measured by the OSEE method was similar to that of the gravimetric method, but that the OSEE method could not be compared with gravimetric method for the case of solder or grease cleaning because the contaminants radiate or absorb ultra-violet light. In case of cutting oil cleaning, the gravimetric method indicated its limitation of cleaning efficiency of cutting oil since it showed cleaning efficiency of 100%, even though residual soil remaining on the substrate surface a little after its cleaning. The comparative experimental results of cleaning ability evaluated by the OSEE- and contact angle measurement methods showed that they were similar in case of cleaning of flux, mixed soil and cutting oil. It was judged that the contact angle measurement method could evaluate the cleaning ability more precisely than the OSEE method for cleaning solder and grease.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.7
• /
• pp.753-761
• /
• 2005

In this study, pretreatment of organic matters with $MIEX^{(R)}$ was evaluated using bench-scale experimental procedures on four organic matters to determine its effect on subsequent UF membrane filtration. For comparison, coagulation process was also used as a pretreatment of UF membrane filtration. Moreover, the membrane fouling potential was identified using different fractions and molecular weights of organic matters. From the removal property of MW organic matters by coagulation process for the sample water NOM and AOM, the removal efficiency of high MW organic matters were much higher than those of low MW organic matters. It was shown that the removal efficiency of high MW organic matter more than 10 kDa was lower than that of low MW organic matter for $MIEX^{(R)}$ process. For the change of permeate flux by the pretreatment process, $MIEX^{(R)}$+UF process showed high removal efficiency of organic matter as compared with coagulation-UF processes, but high reduction rate of permeate flux was presented through the reduction of removal efficiency of high MW organic matter. From sequential filtration test results in order to examine the effect of MW of organic matter on membrane fouling, it was found that the membrane foulant was occurred by high MW organic matter, and the DOC of organic matter less than 0.5 mg/L was working as the membrane foulant. In the case of sample water composed of low MW organic matter less than 10 kDa, since the low MW organic matter less than 10 kDa has high removal efficiency by $MIEX^{(R)}$, low reduction rate of permeate flux is obtained as compared with coagulation-UF processes. In summary, it is required to conduct the research on physical/chemical characteristic of original water before pretreatment process of membrane process is selected, and a pertinent pre-treatment process should be employed based on the physical/chemical characteristic of original water.

• Journal of Distribution Science
• /
• v.16 no.9
• /
• pp.65-77
• /
• 2018

Purpose - A trading area is very closely related to consumer life. A trading area is a cultural and social space that consumes culture and promotes human relationships as well as an economic space where consumers live their daily lives. In this context, a trading area research should be conducted objectively and empirically because it deals with the activities of consumer's life. The purpose of this study is to identify the intrinsic psychological motivation(push motivation) caused when consumers visit a trading area and to demonstrate how the push motivation for a trading area influence on consumer's flow, satisfaction, revisit intention. Research design, data, and methodology - In order to develop research hypotheses for this study, the development procedures for push motivation scale are as follows; (1) generating initial pool of items based on previous studies, (2) expert judgement to evaluate content and face validity, and (3) assessing convergent and discriminant validity using confirmatory factor analysis. In order to achieve these purposes, online surveys were conducted on frequent or familiar visitors to the trading areas around the Gangnam, Kunkuk University and Hongik University Station. Among the 1,343 questionnaires collected, 1,157 cases were analyzed by using SPSS 22.0 and SmartPLS 3.0 statistical package program, except for 186 responses in which responses were judged to be unfaithful. Results - The push motivation was classified into five sub-dimensions of excitement/stimulus, rest/relaxation, exit/refreshing, knowledge/learning and human relationship promotion as multidimensional and complex factors composed of individual and social-related dimensions. The excitement/stimulus and human relationship promotion of push motivation have positive effects on satisfaction. However, all dimensions of the push motivation have positive effects on flow. And flow has a positive effect on satisfaction and revisit intention. Meanwhile, the mediation test using boostrapping shows that flow plays a full mediating role in the relationship between rest/relaxation, exit/refreshing, knowledge/learning and satisfaction, but a partial mediating rol e between excitement/stimulus, human relationship promotion and satisfaction. Finally, satisfaction plays a partial mediating role between flow and revisit intention. Conclusions - This study shows that the push motivation is multidimensional and compositive depending on the situation of a consumer. In addition, it is found that the human relationship promotion(a social-related motivation) has a much more important effect on flow and satisfaction than other push motivations of individual dimensions. It also shows that satisfaction increases when consumers are being flowed at their visit and degree of revisit intention also grows as satisfaction increases. As implications of this study, a marketer should try to understand consumer's visit motivation at first and then develop factors that increase their flow, satisfaction, revisit intention. It also requires a marketer to approach subjects on a trading area more objectively and empirically based on the psychology and behavior of consumers, in order to establish a proper and efficient strategy on development of a trading area.

• Journal of Korean Academy of Nursing
• /
• v.26 no.3
• /
• pp.591-604
• /
• 1996

The surgical hand scrub (SHS) is the single most important procedure in the prevention of post-operative wound infections and yet it remains the most violated of all infection control procedures. The purpose of this study was to gain an overview of SHS habits in operative th atre personnel and to determine knowledge and attitudes to identify whether there is a need for improvement. The subjects for this study included 79 doctors and 94 nurses working in the operative th atres of four hospitals in Incheon City and Kyungki Province. Related data were collected from July 25 to August 10, 1995 by the author. The data were analyzed using descriptive stat-istics and Chi-squre test. The results of the study are summarized as follows : 1. Nurses felt that they conducted SHS for a longer period of time than doctors did(X=20.1, P=.005). 2. Nurses and doctors had some knowledge of slip-ping rings off fingers and the length of nails, but they lacked knowledge on the duration of SHS, handwashing after an operation and on manicure. 3. There were many reasons given for insufficient SHS included : 1) because they were so busy (38%). 2) brushes were too harsh(19.7%). 3) operations were very simple(18.7%). 4) surgical latex gloves provide functional barrier(11.6%). 5) SHSs were troublesome(7.4%) 6) there were no clocks near the sinks(2.5%) and 7) the operative patients were administered antibiotics after operartion(2.1%). 4. Most of nurses and doctors considered SHS to be important in prevention against post operative infections. 5. Nurses were found to do a thorough SHS, but residents were found to neglect SHS. 6. Considering prevention against postoperative infections, most nurses and doctors considered aseptic techniques, environment-sanitary management and SHS more important than the use of antibiotics, the resistance of patients or the method of operation. 7. Half of the nurses and doctors(54.3%) considered surgical latex gloves to function well as a barrier. 8. Half of the nurses (56.4%) and doctors(51.9%) learned SHS as part of the curriculum in their school education and the rest(nurses : 95.7%, doctors : 74.7%) learned SHS as part of their In Service Education. In conclusion, these findings suggest a need to develop an educational program on surgical hand scrub and hospital infection control for surgical personnels, to install clocks near the hand scrub sinks, to consider a violation report for negligent surgical hand scrubs, and to develop a soft brush for hand scrubs in order to increase performance of the surgical hand scrub.

• Child Health Nursing Research
• /
• v.8 no.3
• /
• pp.260-271
• /
• 2002

This study was performed to identify the level of stress recognized by the parents as a support system for their infant patients who were hospitalized in an emergency department, thus to provide the resulting data as the basic material of care intervention for the families of infant patients. This study subjected the parents with infant patients who were hospitalized in emergency department of C University Hospital in Daejeon, and the data was collected from questionnaires for them, dating from Mar. 20, to Jun. 24, 2001 This study used the tool(30 questions) which was originally developed by Ji, Dong-ok (1992) for measuring the stress of families of infant patients in emergency room, and then was modified and complemented by this researcher suitably for infant patients. Collected data was statistically analyzed with frequency, percentage, mean, standard deviation, t-test, ANOVA, by using SPSS WIN10.0 program, and the results were as follows: 1. The stress of parents with infant patients hospitalized in emergency department averaged 3.31 on the basis of 5-point measure, which means that they felt stress beyond means. 2. The factor with high average out of stress factors the parents of infant patients recognized included the followings: 'about the pain of infant patients due to examination(3.91±1.00)'; 'about rare opportunity to be in contact with physician(3.78±1.09)'; 'delay in emergent treatment required for infant patients(3.75±1.31)'; 'delay in the general treatment of infant patients(3.72±1.32)'. Factors of the stress level includes the followings: 'care and medical treatment'(3.46±.72); 'body and diseases'(3.41±.97)'; 'lack of information and supportable resources (3.25±.77)'; and so on. 3. For the stress level according to general characteristics, there were statistically significant differences in the result of the condition of infant patients, medical treatment(P<.01), religion, the procedure of treatment(P<.05). With little preceding studies for infant patients hospitalized in emergency department, this study looked through the level of stress recognized by the parents of infant patients. Based on the comprehension on the parents with infant patients and the knowledge on stress factors recognized by the parents, it is expected that we can seek the methods of care intervention such as explanation of care and treatment procedures, unit policies, continuous interest and emotional supports as well as the provision of information to understand the responses of parents and reduce accompanied stresses.

• Korean Chemical Engineering Research
• /
• v.53 no.4
• /
• pp.496-502
• /
• 2015

Hydrocarbon dew point(HCDP), a property which is the most generally used for describing natural gas condensation, is a very important parameter of natural gas quality specifications. HCDP is strongly influenced by the concentration of the heavier hydrocarbon components, especially $C_6+$, so, along with compliance with gas quality specifications, build up of procedures for obtaining accurate HCDP is essential for gas transmission company, because hydrocarbon condensation present may cause serious operational and safety problems. This study has been carried out in an attempt to measure HCDP accurately by the automatic hydrocarbon dew point meter under the actual field conditions. Measured HCDP also has been compared with calculated HCDP using the composition determined by gas chromatograph and industry accepted equation of state at multiple pressures, along with the cricondentherm. The test results are 1) the automatic hydrocarbon dew point meter was able to measure stable HCDP continuously 2) the automatic hydrocarbon dew point meter has been performed reference measurement by pure propane with a known dew point from literature, and 3) A meaningful differences was observed when comparing the automatic hydrocarbon dew point meter and gas chromatograph results for synthetic standard gas mixtures and real gas mixtures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.36 no.3
• /
• pp.202-205
• /
• 2010

Introduction: The aim of the present study was to investigate the effect of mechanical irrigation in combination with mouthwash of antimicrobial agents on salivary bacterial counts. Materials and Methods: This study was performed with a randomized study employing a panel of 40 healthy volunteers (20 males and 20 females) between the age of 26 and 32 years. Volunteers were randomly put in one of four treatment groups. In the first group, 0.2 mL of non-stimulatory saliva was collected from every subjective person. Then, saliva was collected after rinsing with chlorhexidine (CHX) for 1 minute. In the second group, non-stimulatory saliva was collected, and then saliva was collected after rinsing with CHX and irrigation with saline. In the third and fourth groups, the same procedures as the first and second groups were performed with povidone iodine (PVI) instead of CHX. All of these samples were cultured for 48 hours aerobically. The reduction rates of colony-forming units (CFU) were calculated for each group. The reduction rate between each group was tested statistically using student t-test. Results: Using CHX in combination with saline irrigation showed a significant decrease of the salivary bacterial CFU when compared with only using CHX.(P<0.01) And using PVI with saline irrigation showed a little decrease of the CFU when compared with only using PVI, but there was no statistical significance.(P>0.01) Conclusion: It was concluded that the CHX or PVI used with saline irrigation made the salivary bacterial counts reduced more than when CHX or PVI was used alone as an oral antiseptic agent.

• Journal of the Korean Dietetic Association
• /
• v.5 no.2
• /
• pp.194-204
• /
• 1999

The objectives of this study were to assess the current practices of implementing selective menus and to identify the perception of foodservice manager and customer on selective menus for hospital foodservice would be fulfilled. Two types of questionnaires for hospital foodservice managers as well as customers were developed. Questionnaires were distributed to managers of 8 hospital foodservice department and 317 customers of patient meal service, and 6 managers and 139 customers were responded. The data were analyzed using frequency and t-test. The results of this study can be summarized as follows : 1. In hospital foodservice operations, the selective menu pattern was first introduced by L hospital on June 1994 in Seoul and recently 8 hospitals were currently implementing selective menus. But using rate of selective menus by patients were relatively low(23.2%), ranging from 15% to 32%. 2. Customers' needs for selective menus were rated significantly higher in the group of patients(4.24/5) who chose the selective menus than their counterpart(3.88/5). 3. The main reason not choosing selective menus was identified by patients as 'not knowing the implementation of selective menus'(52.6%), inconvenient factors in using selective menus for customer were also identified as orders : 'lack of nutrition information on menu item'(38.6%), 'complexity in procedure'(29.8%), and 'lack of menu variety'(26.3%). However managers considered 'managerial burden' and 'limited human resource' as main obstacle to implement the selective menu pattern. 4. Customers indicated 'variety of menu', 'active public relations' as effective methods to enhance using rate of selective menus, however, foodservice manager indicated 'variety of menu'(50%), 'improvement of quality'(16.7%), and 'simplicity in procedure'(16.7%). Based on the results of this study, following recommendations have been suggested : Managers in patient meal service should recognize customer needs for implementing selective menus and pay more attention in implementing selective menus and activating this program. For more effective implementation of activating selective menu program, the foodservice department should establish action plan on 'active publicity work', 'simplicity in procedures', 'variety of menu' and 'improvement of quality'. Especially nutrition informations on meals should be provided for customers in order to elevate participation rate.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.2 no.1
• /
• pp.1-11
• /
• 1999

The Korean government is developing a systematic plan of integrated coastal management for effective conservation, utilization, and development of coastal areas. For this plan, integrated maps of land maps and nautical charts are indispensable. However, these maps are not made, nor studied yet in terms of integration, although digital maps(DM) on land and electronic nautical charts(ENC) have been recently developed by Korean Geography Institute and National Marine Investigation Institute, respectively. In this study, as preliminary studies to make eventual integrated maps, the concept of coastal areas are defined, specifically, coastal lines from DM and ENC are matched against each other. Issues on map production procedures, coordinate systems, and map projections, are carefully considered. A test coastal area located in Seo-Gu, Pusan, over 14 km of coastal lines is selected for the edge matching of coastal lines. RMS differences are 13.83 m and 4.37 m over man-made coastal lines and natural coast lines, respectively, which are quite larger considering a scale difference and other factors. However, no systematic differences are found.

• Journal of Periodontal and Implant Science
• /
• v.30 no.1
• /
• pp.145-157
• /
• 2000

Cytotoxic substances in dental calculus and root cementum of periodontally diseased teeth inhibit new attachment and regeneration. The purpose of scaling and root planing is to remove pathologic structures harboring these cytotoxic substances in order to create a biologically acceptable root surface. However, these procedures inevitably leave a non-biocompatible smear layer. Conventionally, the smear layer has been removed with low pH etching agents such as citric acid, phosphoric acid and tetracycline hydrochloride(TC). Lately, a supersaturated neutral pH etching solution of ethylene diamine tetraacetic acid(EDTA) has been found to be as effective as low pH etchants with respect to smear removal and to be superior in exposing root surfaceassociated collagen. The aim of the present study was to determine the effect of root surface treatment using EDTA on the initial attachment of human gingival fibroblasts. 27 human teeth, extracted due to severe periodontitis, were cut into dentin slices after root planing. The specimens were divided into TC group(treated with $50㎎/m{\ell}$ tetracycline-HCl, pH 1.52), EDTA group(treated with 17% EDTA, pH 7.4), and non-treated control group. After sterilization, 5th subcultured human gingival fibroblasts were seeded in each culture well containing a prepared root slice and incubated for 15 min., 60 min., and 4 hours in 5% $CO_2$ incubator at $37^{\circ}C$. At each incubation time, the number of attached fibroblasts were counted on the microphotographs taken at a magnification of x100. The difference of the number of attached cells between groups was statistically analyzed by the ANOVA followed by Duncan test in SPSS/PC＋programs. The results were as follows : 1. After incubation for 15 min, the attached cells were significantly more in EDTA group and TC group than non-treated control group(p<0.05), but there was no significance in the difference between EDTA group and TC group(p>0.1). 2. After incubation for 60 min and 4 hours, there was no significant difference in the number of attached cells between all groups(p>0.1). 3. In both EDTA group and TC group, there was no significant difference in the number of attached cells between different incubation(p>0.1). But in control group, the number of attached cells was significantly increased after incubation for 60 min, compared with incubation for 15 min(p<0.05). The above results suggest that root surface treatment using EDTA could enhance the initial attachment of gingival fibroblasts to root surface as effective as tetracycline-HCl.