• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.14-25
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• 2010

This study was carried out to investigate the soil salinity and salt spray drift of the indigenous windbreak trees, and its main purpose was to provide basic data for the selection of salt-tolerant trees in the saline coastal region in the South Sea of Korea. The soil salinity($EC_{1:5}$)was $0.18dSm^{-1}$, which was an average degree of the whole areas of investigation whose salinity degree ranged from $0.05dSm^{-1}$ to $0.58dSm^{-1}$. The level of soil salinity gradually decreased as it moved farther inland, except the belt I. The level of decreasing soil salinity was found to be in the following order: belt II, belt III, belt I, belt IV. The degree of soil salinity was $EC_{1:5}$ $0.22dSm_{1:5}$, $0.22dSm_{1:5}$ $0.19dSm^{-1}$ and $0.13dSm^{-1}$ respectively. The total 110 taxa, which consisted of 45 families, 74 genus, 101 species, and 9 varieties, were found to be tolerant to both soil salinity and salt spray drift. The trees that grow in the highest degree of salinity($EC_{1:5}$ $0.50dSm^{-1}$)were Parthenocissus tricuspidata(Siebold & Zucc.), Planch and Lonicera japonica Thunb. The next group of trees that grow in the high degree of salinity ranging from $EC_{1:5}$ 0.41 to $0.50dSm^{-1}$ was Cudrania tricuspidata(Carr.) Bureau ex Lavall$\acute{e}$e, Rubus parvifolius L., Zanthoxylum schinifolium(Siebold & Zucc.), Hedera rhombea(Miq.) Bean., Robinia pseudoacacia L., Quercus serrata Thunb., Callicarpa dichotoma(Lour.) K. Koch, and so on. The woody species which grew in the entire belts were Pueraria lobata(Willd.) Ohwi and Vitis flexuosa Thunb., and Vitex rotundifolia L. f. which was known to be highly tolerant to salt spray drift was found only in belt I. The woody species with high important value(IV) were Zelkova serrata(Thunb.) Makino., Celtis sinensis Pers., Koelreuteria paniculata Laxmann, Mallotusjaponicus(Thunb.) Muell. Arg., Trachelospermum asiaticum(Siebold & Zucc.) NAKAI, and Pueraria lobata(Willd.) Ohwi. These species were classified as native windbreak trees that are comparatively more tolerant to salt spray drift than other kinds.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.147-156
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• 2010

This study was conducted from April, 2002 to March 2006, using three urban streams(Gap Stream, Yudeung Stream and Daejeon Stream) in Daejeon Metropolitan City. 12,027 individual birds summed by the peak count in 126 species, 34 families, and 13 orders were observed from three stream sites. Dominant species were of Anas poecilorhyncha, Anas crecca, Columba livia, Passer montanus, and Egretta garzetta(in that order). The groups of birds were classified into six types. The most frequent group were the arbor birds(54 species), while the smallest group was the diving ducks(7 species). As for the number of individuals, the shrub bird group had 721 individuals while the dabbling ducks observed had 4,974 individuals. Regarding the distribution of birds appeareing in each stream, 14,885 individual numbers in 114 species were observed at Gap Stream, 6,642 individuals in 90 species at Yudeung Stream and 4,202 individuals in 69 species at Daejeon Stream. Various indices of the birds were analyzed with respects to the similarities between streams. Gap Stream had similar characteristics to Yudeung Stream, and the latter was similar to Daejeon Stream. However, Gap Stream and Daejeon Stream showed different characteristics. The dominance index of each section was calculated using ten dominant bird species top-down. Subsequently, the birds and their preferred environment were analyzed. The results showed that shrub birds and arbor birds preferred the upper stream of every stream, while herons and dabbling ducks inhabited the midstream. Dabbling ducks and some diving ducks appeared downstream.

• Clean Technology
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• v.18 no.3
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• pp.272-279
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• 2012

In this study, an environmental-friendly cleaning agent utilizing organic acids and various additives has been developed and applied to the field for removal of scale deposited on the cleaning beds or distribution reservoirs of the waterworks. As an analytical result of scale on the cleaning beds, we found that it consists of mainly metallic oxides such as $SiO_2$, $Al_2O_3$, $Fe_2O_3$, and MnO. Malic acid, malonic acid, and citric acid showed relatively better solvency on $Al_2O_3$, $Fe_2O_3$, and MnO except $SiO_2$ among various organic acids. Mixed organic acid solutions of malic acid, malonic acid, and citric acid were prepared with certain weight ratios and their solvencies on mixed metal oxides of $Al_2O_3$, $Fe_2O_3$, and MnO were investigated. The experimental results showed that an 10% mixed organic acid solution prepared with weight ratio of malic acid : malonic acid : citric acid = 6 : 2 : 2 were found to have best scale solvency power of about 29%. The formulated cleaning agents with a small amount of nonionic surfactant showed much better solvency on mixed oxides than mixed organic solution alone. Especially, the formulated cleaning agent with 0.2 wt% LA-7 surfactant appeared to have best scale removal efficiency of about 35%. However, the formulated cleaning agent with disinfectants such as NaClO, $H_2O_2$ and $Ca(ClO)_2$ showed poor solvency on mixed oxides. It is inferred that surfactants are able to improve scale removal efficiency due to their capability of emulsification, and disinfectants cause to degrade scale solvency in water because of their oxidation. Based on these basic experimental results, formulated cleaning agents have been prepared with mixed organic acid solution, nonionic surfactants, and disinfectants and successfully applied to removal of scales on the cleaning beds and distribution reservoir at city D waterworks.

• Journal of dental hygiene science
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• v.1 no.1
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• pp.21-27
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• 2001

The purpose of this study was to explore some of the right directions for school dental-health education, by examining nursing students' knowledge on and attitude to the two major oral diseases in our country, dental caries and periodontal disease, as they will take charge of dental-health education and care for children in school dental-health center as sole expert health personnels after graduation. As a result of making an analysis of their knowledge and attitude, the following findings were acquired: (1) The students investigated perceived their oral cavity to tend to be healthy(36.8%) or in moderate situation(36.3%), although they had a subjective symptom for hot or cold food. (2) They thought dental caries is attributed to poor dental hygiene care(90.4%). Among them, 94.1% found toothbrushing effective for the prevention of dental caries, but just 40.2% agreed that toothbrush should be straight. (3) Those who considered fluoride effective for dental caries prevention thought the best way to use fluoride is taking fluoride-containing tap water(2.00). The second best way was fluoride mouth rinse(2.40), followed by the topical application of fluoride(2.70), use of fluoride dentifrice, and intake of fluoride(4.30) in the order named. (4) The regular examination and toothbrushing were mentioned as a way to prevent dental caries, but just toothbrushing was put in action for dental health. So their knowledge and actual attitude weren't the same. (5) They brushed their teeth for oral health(94.3%). Toothbrushing was done after breakfast(71.9%) or before bedtime(65.8%). Just 40.3% performed toothbrushing after lunch. That was implemented twice(35.7%) or three times(37.6%) a day. (6) Out of those who pointed out toothbrushing as a way to prevent periodontal diseases(84.7%), the effect of toothbrushing on the prevention of periodontitis wasn't supported by 7.1% of those who completed the course of study for the teaching profession and by 17.0% of the others who didn't. The two groups weren't of the same opinion. The above-mentioned findings suggest that the dental knowledge of the nursing students wasn't good enough to be properly responsible for school children's dental health care. In particular, there was a gap between knowledge and attitude. To improve children's poor dental health and help their oral cavity stay healthy, there is a need to activate school dental-health center, which is now in model operation, and to make the most of dental hygienists, who are educated to be a dental-health specialist, for more successful dental-health care for school children.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.307-319
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• 2000

Community structure (seasonal fluctuation), taxon diversity, nematodes/benthic harpacticoids and nematodes/kinorhynchs ratios of meiobenthos were studied in the Gamak Bay, Korea. A series of samplings were carried out from April 1997 to May 1999. Meiobenthic organisms was collected by van Veen grab and three subcores of 34 mm in internal diameter were taken from each sediment sample. The total density of meiobenthos in each seasons was found to be the highest in May 1999, and the lowest in December 1998. Total density of meiobenthos at each station was the highest at Station 9 in May 1999 ($2,218 inds./10 cm^2$) and the lowest at Station 3 in December 1998 ($2 inds./10 cm^2$). The Gamak Bay seemed to have an individual number increased from the inner toward the outer stations. The highest number of meiobenthos was observed on 0.125 and 0.063 mm mesh size. In every season, over $80{\%}$ of the meiobenthos was composed of only four groups: nematodes, benthic harpacticoids, sarcomastigophorans and nauplius larvae of crustaceans. Seasonal fluctuation of meiobenthos was also studied. The nematodes/benthic harpacticoids(nematodes/kinorhynchs) ratios were studied as an index of pollution monitoring for benthic ecosystem at each station in each season. The value of nematodes/benthic harpacticoids ratio was the highest at the inner stations and the lowest at the outer stations in the Gamak Bay. Taxon diversity (H') was the highest at the outer stations and the lowest at the inner stations in the Gamak Bay. The value of nematodes/benthic harpacticoids ratio significantly increased from the outer toward the inner stations, whereas the taxon diversity (H') significantly increased from the inner toward the outer stations in Gamak Bay.

• Korea journal of population studies
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• v.26 no.2
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• pp.1-32
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• 2003

An analysis on cause-specific mortality at the provincial level provides essential information for policy formulation and makes it possible to draw hypotheses regarding various diseases and causes of death. Although the mortality level and causes of death at the provincial level are determined by the multiple effects of socioeconomic, cultural, medical and ecological factors, this study primarily intends to examine similarities and differences of cause-specific mortality at the provincial level. Utilizing the registered death and the registered population as of 1998, the delayed death registration and unreported infant deaths were supplemented at the provincial level and age-standardized death rates and life tables were calculated. Regarding the mortality level due to all causes, major findings were as follow: (1) For both sexes as a whole, Seoul showed the lowest mortality level, and Jeonnam showed the highest mortality level; and (2) The differences of the mortality level among provinces were greater for males than females and for those less than 65 years than those 65 years and over. Regarding the cause-specific mortality level revealed in all indicators (cause-specific age-standardized mortality rates and the probability of dying at birth due to a specific cause for males, females, and both sexes combined respectively), the major findings were as follow: (1) The mortality level due to heart diseases was the highest in Busan and the lowest in Gangweon; (2) The mortality level due to liver diseases was the highest in Chonnam; and (3) The mortality level due to traffic accidents was the highest in Chungnam and the lowest in Inchon. As the mortality differentials at the provincial level are related to various factors, exploratory statistical analysis is attempted for the 25 explanatory variables including socioeconomic variables and 90 mortality variables. Mortality due to all causes are related to socioeconomic variables. Among cause-specific mortality, mortality due to liver diseases and traffic accidents is related to socioeconomic variables. Finally, the need to improve the quality of death certificate is discussed.

• Food Science and Preservation
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• v.22 no.6
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• pp.915-919
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• 2015

This study was performed in order to provide basic data for predicting the usefulness of Jicama (Pachyrhizus erosus) as a food raw material. The changes in the physicochemical properties of freeze-dried and hot air-dried Jicama were investigated and analyzed. The moisture content of raw Jicama was 81.84%. The crude protein, crude fat, crude ash and carbohydrate content of hot air-dried Jicama powder were 2.85, 0.79, 7.93 and 88.44%, while those of freeze-dried Jicama powder were 3.93, 0.83, 7.92 and 87.32%, respectively on dry basis. Regarding the color values, the lightness of freeze-dried Jicama (92.86) was higher than that of the hot air-dried Jicama (88.01), whereas the redness (-0.67) and yellowness (3.21) of freeze-dried Jicama were lower than those of the hot air-dried Jicama (0.43) and (11.96), respectively. The brown index was lower in the freeze-dried Jicama (0.029) than in hot air-dried Jicama (0.107). The total sugar content showed no significant differences between freeze (46.49 mg/g) and hot air-dried Jicama (45.11 mg/g). Finally, the amylose content was higher in freeze-dried Jicama (5.66%) than in hot air-dried Jicama (6.63%).

• Food Science and Preservation
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• v.19 no.2
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• pp.193-200
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• 2012

The quality characteristics of $kalopanax$ $pictus$ and Aralica elata shoots during their preservation were investigated according to the salt conditions and storage temperatures to improve the use of the shoots. The results were as follows: the pH of $kalopanax$ $pictus$ shoots duing their storage did not changes with 10% and 12% brine at $4^{\circ}C$ and with 12% brine at $10^{\circ}C$. The pH of $Aralica$ $elata$ shoots is at $4^{\circ}C$ tended to be similar to the $kalopanax$ $pictus$ shoot and decreased at the storage temperature of $10^{\circ}C$. The salinity of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to increase during their storage and did not change significantly as their storage temperature changed. The L values of $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decrease gradually during their storage, and the salt concentrations appeared high. The b value of the $kalopanax$ $pictus$ shoot tended to increase and that of the $Aralica$ $elata$ shoots, to decrease gradually. The a value tended to increase gradually but did not differ with variations in the storage temperatures and salt concentrations. The strength and the hardness of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decreased gradually during their storage and highest in 10% brine at $4^{\circ}C$, and those of $Aralica$ $elata$ shoots were highest in 8-10% brine at $4^{\circ}C$. The Chlorophyll contents of the $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots tended to decrease during their salt storage and did not change significantly as the temperatures and salt concentrations changed. Therefore, it can be concluded that the quality of $kalopanax$ $pictus$ and $Aralica$ $elata$ shoots can be maintained when the are stored in 10% brine at $4^{\circ}C$.

• Journal of dental hygiene science
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• v.4 no.1
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• pp.13-20
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• 2004

The purpose of this study was to examine how dental hygienists health management and to what extent they used medical care services due to occupational diseases. It's ultimately attempted to improve the health care of dental hygienists and promote their health. After relevant literature and data were reviewed, a survey was conducted for five months from June through October, 2003. The subjects in this study were 160 dental hygienists who worked at dental hospital and clinics across the nation. And the collected data were analyzed. The findings of this study were as follows: (1) Concerning job-related health education experience, 83.1 percent, the greatest rate, had no experience to receive education, and the type of service made a significance difference to that(p<0.05). (2) As to in-house medical examination, 98.6 percent felt the need for medical examination, and 56.3 percent had ever their bodies examined. Their health examination experience was significantly different according to age(p<0.01), marital status(p<0.01), type of service(p<0.01), career(p<0.01) and yearly income(p<0.01). (3) Concerning how much they used hospitals after working as dental hygienists, 85.6 percent, the biggest group, had no experience to be hospitalized, and that was significantly different according to age(p<0.05), type of service(p<0.05), career(p<0.01) and yearly income(p<0.05). 51.9 percent had no experience to receive treatment as outpatients, and their career(p<0.01) made a significant difference to that. (4) As for how to cope with casual diseases, 34.4 percent, the largest group, visited pharmacies, and 32.5 percent, the next largest group, saw the doctors. In regard to herb restorative, 68.1 percent had no experience to take herb restorative, and that experience varied significantly with age(p<0.01), career(p<0.05) and annual income(p<0.01).

• Journal of dental hygiene science
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• v.15 no.1
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• pp.46-53
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• 2015

The purpose of this study is to identify the awareness of oral health workforce and the attitude concerning the health insurance benefit on topical fluoride application. The subjects are 173 dentists and 288 dental hygienists. The data were collected using a self-administered questionnaire and analyzed using SPSS 12.0 statistical program. The findings of the study were as follows: Agree's (including strongly agree) ratios regarding to the health insurance benefit of topical fluoride application was 92.5% for dentists and 90.8% for dental hygienists. Appropriate age of health insurance benefit about the topical fluoride application was elementary, middle and high school students (8~19 years). This response ratio was high 45.7% for dentists and 43.2% for dental hygienists. Appropriate copayment (mean value) of health insurance about topical fluoride application coverage showed that NaF, $SnF_2$ solution and acidulated phosphate fluoride gel were 25,782 Korean Won (KRW) for dentist and 14,282 KRW for dental hygienist. Fluoride varnish copayment was 31,705 KRW for dentist and 17,979 KRW for dental hygienist. Fluoride iontophoresis copayment was 40,156 KRW for dentist, and 21,210 KRW for dental hygienist. The frequency of health insurance benefits about topical fluoride application was high in 'unlimited (37.5%)' for the dentists and 'two times (31.3%)' for dental hygienists. In conclusion, topical fluoride application should be included as one of the health insurance benefit items for oral health.