• The Korean Nurse
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• v.36 no.1
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• pp.77-96
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• 1997

The duty shifts of hospital nurses not only affect nurses' physical and mental health but also present various personnel management problems which often result in high turnover rates. In this context a study was carried out from October to November 1995 for a period of two months to find out the status of hospital nurses' duty shift patterns, and preferred duty hours and fixed duty shifts. The study population was 867 RNs working in five general hospitals located in Seoul and its vicinity. The questionnaire developed by the writer was used for data collection. The response rate was 85.9 percent or 745 returns. The SAS program was used for data analysis with the computation of frequencies, percentages and Chi square test. The findings of the study are as follows: 1. General characteristics of the study population: 56 percent of respondents was (25 years group and 76.5 percent were "single": the predominant proportion of respondents was junior nursing college graduates(92.2%) and have less than 5 years nursing experience in hospitals(65.5%). For their future working plan in nursing profession, nearly 50% responded as uncertain The reasons given for their career plan was predominantly 'personal growth and development' rather than financial reasons. 2. The interval for rotations of duty stations was found to be mostly irregular(56.4%) while others reported as weekly(16.1%), monthly(12.9%), and fixed terms(4.6%). 3. The main problems related to duty shifts particularly the evening and night duty nurses reported were "not enough time for the family, " "afraid of security problems after the work when returning home late at night." and "lack of leisure time". "problems in physical and physiological adjustment." "problems in family life." "lack of time for interactions with fellow nurses" etc. 4. The forty percent of respondents reported to have '1-2 times' of duty shift rotations while all others reported that '0 time'. '2-3 times'. 'more than 3 times' etc. which suggest the irregularity in duty shift rotations. 5. The majority(62.8%) of study population found to favor the rotating system of duty stations. The reasons for favoring the rotation system were: the opportunity for "learning new things and personal development." "better human relations are possible. "better understanding in various duty stations." "changes in monotonous routine job" etc. The proportion of those disfavor the rotating 'system was 34.7 percent. giving the reasons of"it impedes development of specialization." "poor job performances." "stress factors" etc. Furthermore. respondents made the following comments in relation to the rotation of duty stations: the nurses should be given the opportunity to participate in the. decision making process: personal interest and aptitudes should be considered: regular intervals for the rotations or it should be planned in advance. etc. 6. For the future career plan. the older. married group with longer nursing experiences appeared to think the nursing as their lifetime career more likely than the younger. single group with shorter nursing experiences ($x^2=61.19.{\;}p=.000;{\;}x^2=41.55.{\;}p=.000$). The reason given for their future career plan regardless of length of future service, was predominantly "personal growth and development" rather than financial reasons. For further analysis, the group those with the shorter career plan appeared to claim "financial reasons" for their future career more readily than the group who consider the nursing job as their lifetime career$(x^2$= 11.73, p=.003) did. This finding suggests the need for careful .considerations in personnel management of nursing administration particularly when dealing with the nurses' career development. The majority of respondents preferred the fixed day shift. However, further analysis of those preferred evening shift by age and civil status, "< 25 years group"(15.1%) and "single group"(13.2) were more likely to favor the fixed evening shift than > 25 years(6.4%) and married(4.8%)groups. This differences were statistically significant ($x^2=14.54, {\;}p=.000;{\;}x^2=8.75, {\;}p=.003$). 7. A great majority of respondents(86.9% or n=647) found to prefer the day shifts. When the four different types of duty shifts(Types A. B. C, D) were presented, 55.0 percent of total respondents preferred the A type or the existing one followed by D type(22.7%). B type(12.4%) and C type(8.2%). 8. When the condition of monetary incentives for the evening(20% of salary) and night shifts(40% of. salary) of the existing duty type was presented. again the day shift appeared to be the most preferred one although the rate was slightly lower(66.4% against 86.9%). In the case of evening shift, with the same incentive, the preference rates for evening and night shifts increased from 11.0 to 22.4 percent and from 0.5 to 3.0 percent respectively. When the age variable was controlled. < 25 yrs group showed higher rates(31.6%. 4.8%) than those of > 25 yrs group(15.5%. 1.3%) respectively preferring the evening and night shifts(p=.000). The civil status also seemed to operate on the preferences of the duty shifts as the single group showed lower rate(69.0%) for day duty against 83. 6% of the married group. and higher rates for evening and night duties(27.2%. 15.1%) respectively against those of the married group(3.8%. 1.8%) while a higher proportion of the married group(83. 6%) preferred the day duties than the single group(69.0%). These differences were found to be statistically all significant(p=.001). 9. The findings on preferences of three different types of fixed duty hours namely, B, C. and D(with additional monetary incentives) are as follows in order of preference: B type(12hrs a day, 3days a wk): day shift(64.1%), evening shift(26.1%). night shift(6.5%) C type(12hrs a day. 4days a wk) : evening shift(49.2%). day shift(32.8%), night shift(11.5%) D type(10hrs a day. 4days a wk): showed the similar trend as B type. The findings of higher preferences on the evening and night duties when the incentives are given. as shown above, suggest the need for the introductions of different patterns of duty hours and incentive measures in order to overcome the difficulties in rostering the nursing duties. However, the interpretation of the above data, particularly the C type, needs cautions as the total number of respondents is very small(n=61). It requires further in-depth study. In conclusion. it seemed to suggest that the patterns of nurses duty hours and shifts in the most hospitals in the country have neither been tried for different duty types nor been flexible. The stereotype rostering system of three shifts and insensitiveness for personal life aspect of nurses seemed to be prevailing. This study seems to support that irregular and frequent rotations of duty shifts may be contributing factors for most nurses' maladjustment problems in physical and mental health. personal and family life which eventually may result in high turnover rates. In order to overcome the increasing problems in personnel management of hospital nurses particularly in rostering of evening and night duty shifts, which may related to eventual high turnover rates, the findings of this study strongly suggest the need for an introduction of new rostering systems including fixed duties and appropriate incentive measures for evenings and nights which the most nurses want to avoid, In considering the nursing care of inpatients is the round-the clock business. the practice of the nursing duty shift system is inevitable. In this context, based on the findings of this study. the following are recommended: 1. The further in-depth studies on duty shifts and hours need to be undertaken for the development of appropriate and effective rostering systems for hospital nurses. 2. An introduction of appropriate incentive measures for evening and night duty shifts along with organizational considerations such as the trials for preferred duty time bands, duty hours, and fixed duty shifts should be considered if good quality of care for the patients be maintained for the round the clock. This may require an initiation of systematic research and development activities in the field of hospital nursing administration as a part of permanent system in the hospital. 3. Planned and regular intervals, orientation and training, and professional and personal growth should be considered for the rotation of different duty stations or units. 4. In considering the higher degree of preferences in the duty type of "10hours a day, 4days a week" shown in this study, it would be worthwhile to undertake the R&D type studies in large hospital settings.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.254-261
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• 2014

BACKGROUND: This study was conducted to investigate effects of silicate fertilizer application on red pepper (Capsicum annuum L.) productivity with improving soil chemistry under plastic film house in paddy field. METHODS AND RESULTS: The silicate fertilizer was applied as 0, 100, 200, and 300 kg/10a as basal dressing before transplanting pepper plant seedlings. Cultivar of the pepper plant was Cheon-Ha-Dae-Se. Amounts of inorganic fertilizer applied as $N-P_2O_5-K_2O$=19.0-6.4-10.1kg/10a was estimated depending on soil test values. After applying 50% of nitrogen, 100% of phosphorus, and 60% of potassium fertilizers as basal dressing, the seedlings of pepper plant were transplanted. The rests of nitrogen and potassium fertilizers were applied as side-dressing after the first, second, and fourth harvests of red pepper. When comparing selected chemical properties of soils between before transplanting and after final(the fifth) harvest, soil pH, available $P_2O_5$, and exchangeable $Ca^{2+}$ increased with increasing the applications of silicate fertilizer, whereas electrical conductivity(EC) decreased. However, exchangeable $K^+$ was higher with the treatments of 100 and 200 kg/10a, and exchangeable $Mg^{2+}$ was higher with 300 kg/10a application. In addition, nitrogen and phosphorus concentrations of red pepper collected from the first harvesting stage decreased with increasing the applications of silicate fertilizer, but potassium, calcium, and magnesium concentrations in red pepper were highest with 300 kg/10a application. Yield of red pepper increased between 9.0 and 11.8% with the applications of silicate fertilizer. Marketable fruit rate of res pepper was highest(97.3%) with 200 kg/10a application. CONCLUSION: The application of silicate fertilizer as basal dressing in paddy-converted fields improved soil chemistry and increased red pepper productivity.

• Journal of Preventive Medicine and Public Health
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• v.20 no.2 s.22
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• pp.228-235
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• 1987

The objective of this study is to examine the correlation between the toluene concentration in the work environment of organic solvents and the concentration of hippuric acid in urine of workers exposed toluene, and to acquire the fundamental materials of workers' health care and to assist the assessment of the biological permisible exposure limit. The control groups are 72 workers who had never been exposed to toluene and the case groups are 101 workers who had been exposed to toluene. This study was conducted to examine the correlation between the concentration of toluene in work environment and workers' hippuric acid concentration, to investigate the complaint difference of subjective symptoms by means of questionaire, between the case groups and control groups. The results and conclusions are as fellows: 1) The highest mean concentration of toluene in the air is $544.13{\pm}7.75ppm$ in the Printing Department of mixing organic solvents. The concentrations of the others are $463.27{\pm}5.24ppm$ in Department of mixture for organic solvents, and $393.56{\pm}45.69ppm$ in the Printing Department(1), and $248.38{\pm}45.16ppm$ in the Printing Department(2), and $159.38{\pm}18.51ppm$ in the Printing Department(3). 2) The highest mean concentration of hippuric acid in urine is $6034.84{\pm}1298.35mg/l$ in the Printing Department with mixing organic solvents. The concentrations of the others are $4798.44{\pm}784.53mg/l$ in Department of mixture of organic solvents, and $2883.06{\pm}701.90mg/l$ in the Printing Department(1), and $1449.98{\pm}905.19mg/l$ in the Printing Department(2), and $598.52{\pm}299.43mg/l$ in the Printing Department(3). 3) As the toluene concentration in the work environment becomes higher, the concentration of hippuric acid in urine also becomes higher. It is found that the coefficient of correlation between toluene concentration and the concentration of hippuric acid are positive (r=0.868, Y=7.18X+349.57) 4) It is found that the case groups complain of much more subjective symptoms than the control groups.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.1
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• pp.70-75
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• 1997

An improved technique based upon an electron beam evaporation system has been developed to prepare cubic thin films In crystalline semiconductors. Zinc blonde CdSe epilayers were grown on GaAs(100) substrate by an e-beam evaporation method. The lattice parameter obtained from (400) reflection is $6.077\AA$, which is in excellent agreement with the value reported in the literature for zinc blonde CdSe. The orientation of the as-grown CdSe epilayer is determined by electron channeling patterns. The crystallinity of epitaxial CdSe layers were investigated on the double crystal X-ray rocking curve. The carrier concentration and mobility of epilayers deduced by Hall effect measurement are about $10^{18}{\textrm}{cm}^{-3}$, $10^2\textrm{cm}^2/V{\cdot}sec$ at room temperature, respectively. The photocurrent spectrum peak of the epilayer at 30 K exhibits a sharp change at 1.746 eV due to the free exciton of cubic CdSe.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.573-579
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• 2019

The purpose of this study is predicted easily the entrance surface dose (ESD) in chest digital radiography. We used two detector type such as flat-panel detector (FP) and IP (Imaging plate detector). ESD was measured at each exposure condition combined tube voltage with tube current using dosimeter, after attaching on human phantom, it was repeated 3 times. Phantom images were evaluated independently by three chest radiologists after blinding image. Dose-area product (DAP) or exposure index (EI) was checked by Digital Imaging and Communications in Medicine (DICOM) header on phantom images. Statistical analysis was performed by the linear regression using SPSS ver. 19.0. ESD was significant difference between FP and IP($85.7{\mu}Gy$ vs. $124.6{\mu}Gy$, p=0.017). ESD was positively correlated with image quality in FP as well as IP. In FP, adjusted R square was 0.978 (97.8%) and linear regression model was $ESD=0.407+68.810{\times}DAP$. DAP was 4.781 by calculating the $DAP=0.021+0.014{\times}340{\mu}Gy$. In IP, adjusted R square was 0.645 (64.5%) and linear regression model was $ESD=-63.339+0.188{\times}EI$. EI was 1748.97 by calculating the $EI=565.431+3.481{\times}340{\mu}Gy$. In chest digital radiography, the ESD can be easily predicted by the DICOM header information.

• Journal of dental hygiene science
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• v.8 no.3
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• pp.189-198
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• 2008

Objective: The study aimed to provide basic data for enhancing dental hygienists' practice of prevention for infections of dental hygienists by examining what factors there were in their preventing the infections in dental clinics. Method: The subjects of study were 168 dental hygienists who participated in continuing medical education of Incheon & Gyeonggi-do association and Seoul city association in October and November 2005. For the data analysis, an SPSS WIN 13.0 program was used and its significance level was 0.05. In terms of analysis methods, frequency analysis and technical statistics analysis were performed for general characteristics, ANOVA was performed for general traits, practice, medical environments for knowledge and practice analysis, correlation analysis was performed for the relation between knowledge & organization-related factors and practice, Chi-Square Tests were performed for the relation between general traits and educational experiences, T-test was performed for practice and knowledge according to the educational experiences for preventing infections and multiple regression analysis was performed for the factors that affect the practice for preventing infections. Result: knowledge showed statistically significant differences by age (F=4.895, p=0.003) and those with the education experiences in preventing infections had higher scores in practice of prevention for infections than those without them (t=3.315, p=0.001). The correlation between knowledge and practice was significant statistically (p<0.05), the factors related to organization showed significant correlation (p<0.01) and the higher the factors related to organizations, knowledge, education experiences, service career, the higher the practice for prevention of infections was ($R^2=0.32$). Conclusions: In order to enhance the dental hygienists' practice for the prevention of infections, it would be necessary to treat the contents of the infection prevention in educational curriculum at schools and enhance dental hygiene students' knowledge on the prevention of infection and to develop the programs, with which continuous education and PRS could be conducted through in-house education and continuing medical education of the hospital after school graduation and it has been believed that it would be the most important for dental hygienists to make efforts and interest in organizations actively so as to build up safe working environments.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.67-77
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• 1983

To investigate the an air pollution by particulate matter and its dispersion, a cement plant produceing portland cement 600,000 ton/year and its vicinity were surveyed from Obtober, 1980 to April, 1983. The survey was mainly focused on main stack emmission rate of the cement plant and particle size distribution in the dust, dustfall and total suspended particulate concentration in the area by month and distance from the stack. The results of the study were as follows; 1. The main stack emission rate was surveyed before and after the spray tower was additionally installed to the original E.P bag filter. Before the spray tower installed, the main stack emission rate was higher ($0.64g/Nm^3$) than the emission standard of Korean Environmental Preservation Law's ($0.59g/Nm^3$, amended to $0.4g/Nm^3$ on April 1983), but after the spray tower was installed, its main stack emission rate was markedly decreased to the standard ($0.43g/Nm^3$). 2. $2{\sim}3{\mu}m$ of the particle size was the largest portion (20.8%) of the dust particulate from the main stack and 50% of the frequency distribution was $1.5{\mu}m$ of the size. Most particle size was below $10{\mu}m$. 3. The spray tower reduced the dustfall to $37.81{\sim}9.76\;ton/km^2/month$ while dustfall appeared at $45.29-15.45ton/km^2/month$, in the vicinity of plant before spray tower installed 4. Mean concentrations of total suspended particulate for 24 hours of the various stations were determined in $20.6-200.0{\mu}g/m^3$, 3 stations of tham were higher than the value of Harry and William's arthmetic average standard $130{\mu}g/m^3$. 5. Linear regression between dustfall [X] and total suspended particulate[Y] concentration was an equation, Y=4.024X+11.479.[r=0.91] 6. During the whole seasons in the opposite area 100m apart from the omission source the prevailing wind direction was with estimated more than $30ton/km^2/month$, and the concentration of total suspended particulate for 24 hours averaging time was more than $140{\mu}g/m^3$ in the same area and direction. 7. Assuming the wind direction were constant through the day dustfalls for a day were estimated at $13.40ton/km^2/day,\;10.79ton/km^2/day$ and $4.55ton/km^2/day$ at various distances of 100m, 500m and 1,500m from the emission source respectively. 8. In the simutalion of dustfall and suspended dust by area, Gaussian dispersion model modified by size distribution of particulate matter was not applicated since the emission of dust were from multi sources other them stack. From the above results, it could be applied that the dispersion of dust from the cement plant is estimated and regulated for the purpose of environmental protection.

• Food Science and Preservation
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• v.16 no.5
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• pp.734-741
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• 2009

Response surface methodology (RSM) was used to optimize extraction conditions for functional components of buckwheat (Fagopyrum esculentum). A central composite design was applied to investigate the effects of three independent variables, namelyextraction temperature (X1), extraction time (X2), and ethanol concentration (X3), on responses including extraction yield (Y1), total phenolic content in the extract (Y2), $\alpha$-glucosidase inhibition activity (Y3), and acetylcholine esterase (ACE) inhibition activity (Y4). Data were analyzed using an expert design strategy and statistical software. The maximum yield was 24.95% (w/w) at $55.75^{\circ}C$ extraction temperature, 8.75 hextraction time, and 15.65% (v/v) ethanol. The maximum total phenolic yield was 222.45 mg/100 g under the conditions of $28.11^{\circ}C$ extraction temperature, 8.65 h extraction time, and 81.72% (v/v) ethanol. The maximum $\alpha$-glucosidase inhibition activity was 85.38% at $9.62^{\circ}C$, 7.86 h, and 57.58% (v/v) ethanol. The maximum ACE inhibition activity was 86.91% under extraction conditions of $10.12^{\circ}C$, 4.86 h, and 44.44% (v/v) ethanol. Based on superimposition of a four-dimensional RSM with respect to levels of total phenolics, $\alpha$-glucosidase inhibition activity, and ACE inhibition activity, obtained under various extraction conditions, the optimum ranges of conditions were an extraction temperature of $0-70^{\circ}C$, an extraction time of 2-8 h, and an ethanol concentration of 30-80% (v/v).

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.524-540
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• 2005

This study has focused on the amount of evaporites and geochemical characteritics of evaporites from the acid mine drainage and on the variation of constituents in acid mine drainage during evaporation. The various colors of evaporites are frequently observed at the rock surfaces contacting acid mine drainage. In order to produce evaporites in the laboratory, acid mine drainages were sampled from the abandoned mine areas (GTa, GTb, GH and GB) and air-dried at room temperature. During the evaporation of acid mine drainages, TDS, EC values and the concentrations of major and minor ions increased, whereas ER and DO values decreased with time. The concentration of Fe increased gradually with evaporation time in the GTb and GB, whereas GH founded in one day but rapidly not detected in the other day after due to removal of Fe by formation-precipitation of amorphous Fe hydroxide. The amounts of the evaporites were produced in amounts of 4 g (GTa), 5 g (GB), 15 g (GH), and 24 g (GTb) from 4 liter of acid mine drainage after 80 days of the evaporation, respectively. In linear analysis from the products with the parameters which are the EC, TDS, salinity, ER, DO and pH contents in field, the determination coefficients were 0.98, 0.99, 0.98, 0.88, 0.89, and 0.25 respectively. If we measure the parameters in field, it would be easy to estimate the amount of evaporites in acid mine drainage. Gypsum and epsomite were identified in all of the evaporites by x-ray powder diffraction studies. Evaporite (GTb) was heated at 52, 65, 70, 95, 150, 250, and 350oC for one hour in electrical furnaces. Gypsum, $CaSO_4\cdot1/2H_2O$ and kieserite were identified in the heated evaporite by XRD. With increased heating temperature, the intensity of the peak at $7.66/AA$ (diagnostic peak of gypsum), the peak at 5.59A ($CaSO_4{\cdot}1/2H_2O)$ and the peak at $4.83{\AA}$ (kieserite) decreased in x-ray diffraction due to dehydration. In the SEM and EDS analysis for the evaporite, gypsum of well-crystallized, radiating cluster of fibrous, acicular, and columnar shapes were observed in all samples. Ca was not detected in the EDS analysis of the flower structures of GTb. Because of that, the evaporite with flower structures is thought to be eposmite.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.809-815
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• 1996

$Y_2O_3$-based metal-insulator-semiconductor (MIS) structure on p-Si(100) has been studied. Films were prepared by UHV reactive ionized cluster beam deposition (r-ICBD) system. The base pressure of the system was about $1 \times 10^{-9}$ -9/ Torr and the process pressure $2 \times 10^{-5}$ Torr in oxygen ambience. Glancing X-ray diffraction(GXRD) and in-situ reflection high energy electron diffracton(RHEED) analyses were performed to investigate the crystallinity of the films. The results show phase change from amorphous state to crystalline one with increasingqr acceleration voltage and substrate temperature. It is also found that the phase transformation from $Y_2O_3$(111)//Si(100) to $Y_2O_3$(110)//Si(100) in growing directions takes place between $500^{\circ}C$ and $700^{\circ}C$. Especially as acceleration voltage is increased, preferentially oriented crystallinity was increased. Finally under the condition of above substrate temperature $700^{\circ}C$ and acceleration voltage 5kV, the $Y_2O_3$films are found to be grown epitaxially in direction of $Y_2O_3$(1l0)//Si(100) by observation of transmission electron microscope(TEM). Capacitance-voltage and current-voltage measurements were conducted to characterize Al/$Y_2O_3$/Si MIS structure with varying acceleration voltage and substrate temperature. Deposited $Y_2O_3$ films of thickness of nearly 300$\AA$ show that the breakdown field increases to 7~8MV /cm at the same conditon of epitaxial growing. These results also coincide with XPS spectra which indicate better stoichiometric characteristic in the condition of better crystalline one. After oxidation the breakdown field increases to 13MV /cm because the MIS structure contains interface silicon oxide of about 30$\AA$. In this case the dielectric constant of only $Y_2O_3$ layer is found to be $\in$15.6. These results have demonstrated the potential of using yttrium oxide for future VLSI/ULSI gate insulator applications.