• Korean Chemical Engineering Research
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• v.53 no.3
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• pp.364-371
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• 2015

For the cost down of polymer concrete, It is very important to reduce the use amount of polymer binder, which occupies most of the production cost of polymer concrete. Fly ash and atomizing reduction steel slag are spherical materials obtained from industrial by-products. Spherical atomizing reduction steel slag was manufactured using steel slag from reduction process of ladle furnace by atomizing technology. To investigate the physical properties of polymer concrete, polymer concrete specimens were prepared with the various proportions of polymer binder and replacement ratios of atomizing steel slag. Results showed that compressive and flexural strengths of the specimens were remarkably increased with the addition amount of polymer binder and the replacement ratios of atomizing steel slag. In the hot water resistance test, compressive strength, flexural strength, bulk density and average pore diameter decreased but total pore volume and pore diameter increased. We found that polymer concrete developed in this study reduced the amount of polymer binder by 18.2% compared to the conventional product because of the remarkable improvement of workability of polymer concrete using spherical fly ash and atomizing reduction steel slag instead of calcium carbonate (filler) and river sand (fine aggregate).

• KSBB Journal
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• v.13 no.2
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• pp.174-180
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• 1998

Enhanced production of (10-deacetyl) baccatin III and related taxanes was observed in suspension cultures of Taxus baccata Pendula. six % of initial glucose and sucrose concentration increased 10-deacetyl baccatin III production 3.5 and 2.5 times, respectively. Methyl jasmonate, as an elicitor, increased taxane production. Time course changes of taxane production after methyl jasmonate addition showed that baccatin II and 10-deacetyl baccatin III were detected first and paclitaxel, 10-deacetyl taxol and cephalomanine were produced in sequence. Feeding experiments with $500{\mu}M$ of benzoic acid increased 10-deacetyl baccatin III production 10 times. Baccatin III production was also increased 8 times by feeding of $500{\mu}M$ of lysine as a precursor.

• Journal of the Korea Institute of Building Construction
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• v.16 no.2
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• pp.97-105
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• 2016

Recently, application case of the ultra rapid hardening concrete-polymer composite(URHCPC) are increasing to repair for the deterioration of pavement. But it is a major disadvantage that the main material is expensive and has environmental load. For these reasons, the development of the economic, eco-friendly materials is needed. Calcium Aluminate Composite (CAC), produced by rapid cooling of atomizing method with molten ladle furnace slag, is a material capable of improving the economic feasibility and reducing the environmental load of URHCPC. In this paper, the properties of CAC and gypsum mixed CAC (GC) as alternative materials of RSC according to the types of polymer dispersion were studied. The results were as follows; compressive strength, tensile strength, flexural strength, bonding strength and modulus of elasticity of the composites using CAC or GC showed higher values than those of plain proportion in 3 hour. In later age, they were at the same level as the general proportions. URHCPC using BPD as polymer dispersion had superior strength properties generally. But modulus of elasticity was the same level as the case of using a SBR latex. According to these results, CAC or GC can partially substituted for RSC to product the URHCPC. When URHCPC uses the BPD as the polymer dispersion, it can be improved performance.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.279-286
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• 2010

To investigate the correlation between the perceived symptom of musculoskeletal diseases and psychosocial factors in dental professionals in Chungcheong province, a self-administered survey was conducted on 206 dental professionals in Chungcheong province from March 9th, 2009 to March 28th, 2009. SPSS WIN 12.0 software was used to analyze the data and the following results were obtained. 1. As for the perceived symptom degree of musculoskeletal diseases based on measured body parts, the frequency of 'high' was the highest in all the parts of the body. 2. As for gender, females showed higher interest in musculoskeletal diseases than males (p=.000). As for age, subjects ranged 26~30 years showed the highest interest in musculoskeletal diseases, which was statistically significant (p=.000). 3. Work satisfaction showed a positive correlation with the perceived symptom of musculoskeletal diseases in lumbar group and lower extremity group. Work stress showed a weak negative correlation with the perceived symptom of musculoskeletal diseases in lumbar group and lower extremity group. Coworker satisfaction showed a positive correlations with the perceived symptom in upper extremity group and lower extremity group. Hospital satisfaction showed a positive correlations with the perceived symptom in upper extremity group, lumbar group and lower extremity group. Working environment satisfaction showed a positive correlations with the perceived symptom in neck group, shoulder group, upper extremity group and lower extremity group. This study showed a correlation between psychosocial factors and the perceived symptom of musculoskeletal diseases based on body parts. Therefore, psychosocial factors should be considered when the prevention and management program of musculoskeletal diseases are developed.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.259-264
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• 2001

Toxicological studies of two potential biological control agents, the entomopathogenic nematode (Steinernema carpocapsae) and the symbiotic bacteria (Xenorhabdus nematophilus) were conducted against two beneficial insects and one mammal species. Two microbial agents varied in their toxicities between two insect species: an ant, Pristomyrmex pungens, and silkworm, Bombyx mori. In oral toxicity test, the symbiotic bacteria resulted in significant lethal [half lethal concentration of $1.4$\times$10^3$colony-forming units (cfu)/ml] on the ants, while they gave little lethal effect (half lethal concentration of more than $10^{8}$ cfu/ml) on the silkworms. The nematodes, however, gave significant lethal effect [half lethal concentration of 4 infected juveniles (IJs)/ml] on the silkworms, while they did little lethal effect (half lethal concentration of 150,000 IJs/ml) on the ants in topical assays. Both the nematodes and the bacteria did not give lethal effect to the albino rats, Rattus norvegicus, when they were fed orally into the rats. Also, any of these microbial agents were not detected in the internal organs of the treated rats.

• Proceedings of the KSCN Conference
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• 2003.11a
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• pp.1083-1084
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• 2003

사회생활 양식이 점차 복잡해지고 생활전반의 조직이 고도화됨에 따라 대규모 급식의 필요성이 점점 증가되고 있다. 그 동안 단체급식은 자체적으로 운영하는 경우가 많았으나, 최근 들어 위탁운영의 효율성에 대한 인식이 높아짐에 따라 위탁 운영률이 크게 높아지고 있다. 현재까지 대학급식에 관한 연구는 대학식당의 이용실태, 대학 식단의 만족도 평가, 대학급식 메뉴 관리 및 운영 등을 조사한 연구는 많았으나 운영형태에 따른 식단 분석 연구는 미흡한 실정이다. 이에 본 연구에는 서울 시내 일부 대학교의 구내에 있는 5개 식당 23가지 식단에 대하여 직영급식과 위탁급식으로 나누어 학생들에게 제공되는 메뉴를 영양가면과 다양성 면에서 평가하고, 제공된 메뉴를 학생들이 실제 섭취하는 실태를 조사하여 섭취한 식단의 영양가와 음식의 종류를 분석하였다. 본 조사에서 이용한 식단은 총 23가지였고, 그 중에서 직영급식 13가지, 위탁급식 10가지였다. 제공된 상용식단형태는 직영급식은$\ulcorner$밥+국+반찬2+김치1$\lrcorner$, 위탁급식은 $\ulcorner$한그릇+국+반찬1+김치1$\lrcorner$이었으며, 우리나라 전통의 기본패턴을 갖추고 있었다. 제공된 식단 중 한끼 영양소 함량을 평가해본 결과 여자의 경우 1/3 영양권장량을 제공하였으나, 남자의 경우는 부족하였다. 제공되는 식단의 음식군별 제공열량을 살펴보면 밥은 평균 399㎉, 한그릇음식은 425㎉로 한 그릇음식의 경우가 높은 열량을 제공하고 있었다. 반찬의 경우 1가지로부터 얻는 열량은 평균 107㎉였으며 김치의 경우는 9.84 ㎉였다. 직영급식과 위탁급식으로 나누어 살펴보면 한 그릇음식, 반찬, 김치의 제공열량이 위탁급식에서 약간 높은 경향을 보였다. 대상자의 음식의 평균 가짓수는 직영 5.5가지, 위탁 4.3가지였으며, 음식 및 반찬 가짓수가 증가할수록 섭취열량이 증가하였다. 대상자들의 섭취한 식단의 한끼당 섭취한 영양소 함량은 직영급식 524㎉, 위탁급식 494㎉였고, 단백질, 지질, 인, 철, 비타민A, 나이아신 등이 유의적으로 직영급식에서 높았다(p<0.001) 섭취한 식단의 영양소 함량은 인과 비타민C를 제외한 모든 영양소에서 권장량에 미달되었다. 섭취한 식단의 영양소적정섭취비는 대부분 0.4-0.9의 값을 보였고, 평균적정섭취비도 직영, 위탁 모두 0.68로 낮은 값을 보였다. 영양소 밀도의 경우 절대적 섭취에서 직영급식이 대부분의 영양소를 많이 섭취하고 있는 것과는 달리 위탁급식에서 철분의 밀도가 유의적으로 높았다(p<0.01). 총 대상자들이 식단에서 섭취한 열량을 살펴보면, 주식류의 경우 밥은 298㎉, 한 그릇음식은 386㎉로 한 그릇음식이 많은 열량을 제공하고 있었다. 반찬의 경우는 1가지로부터 얻는 열량은 78㎉, 김치는 8㎉였다. 이상의 결과로 볼 때, 제공량은 직영급식에서 많았으나 영양밀도 면에서는 큰 차이가 없는 것으로 보아 위탁급식의 제공량을 늘린다면 급식운영형태별 두 식단의 질적 차이가 크게 줄어들 것으로 보인다. 그러나 두 급식 형태 모두 제공식단의 영양소 함량은 다른 지역이나 연령에 비해 부족한 것으로 나타나 아침 결식 및 불규칙한 식사 등 영양상태가 좋지 못한 대학생들에게 교내 식당에서 질 높은 식사를 제공해야 할 것이다. 또한 식단 작성 시 학생들의 메뉴 기호도를 충분히 반영시키고 다양한 메뉴를 제공하는데 한계가 있다면 주.부식 외에 다양한 후식제공을 통하여 학교 급식에 대한 질을 향상시키는 노력을 해야 할 것이다.

• Korean Journal of Plant Resources
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• v.18 no.2
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• pp.285-301
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• 2005

This study was conducted to prepare systematic and efficient measures for nature conservation and management in Beomseom Island, and to clarify characteristics of distribution of plant resources in southernmost islands of Korean peninsula. The numbers of vascular plants were summarized as 164 taxa included 6 families, 13 genera, and 15 species in pteridophyta, 1 family, 1 genus, and 1 species in coniferophyta, and 59 families, 126 genera, 146 species, and 2 varieties in endospermae composed of 49 families, 97 genera, 114 species, and 1 variety in dicotyledonae and 10 families, 29 genera, 32 species, and 1 variety monocotyledonae. Unrecorded taxa of the flora of Beomseom Island were 19 taxa included 4 taxa of pteridophyta, i.e. Hypolepis punctata, Cyrtomium fortunei, Dryopteris pacifica, and Thelypteris granduligera, 6 taxa of monocotyledonae, i.e. Setaria viridis, Zizania latifolia, Scirpus triangulatus, Zantedeschia aethiopica, Spirodela polyrhiza, and Dioscorea nipponica, and 9 taxa of dicotyledonae, i.e. Alnus firma, Boehmeria Platanifolia, Aconogonum ajanense, Phytolacca americana, Melandryum oldhamianum var. roseum, Vitis flexuosa, Clerodendron trichotomum, Elaeagnus glabra, and Siegesbeckia glabrescens. The two rare species, Osmanthus insularis that distributed only Jeju-do and Geomoondo Island and Orostachys iwarenge that distributed only southern parts of Jeju-do in Korea were investigated. The numbers of naturalized plants were 20 families, 33 genera, 34 species, and 1 variety.

• Korean Journal of Plant Resources
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• v.19 no.4
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• pp.537-554
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• 2006

This study aims to investigate the distribution of the useful economic plants and the flora of Maninsan. The flora of Maninsan was investigated from March to November in 2003. Vascular plants of this area consist of total 450 taxa; 5 forma, 53 varieties, 392 species, 279 genera, 95 families. It corresponds to 11.1% of totally 4,071 taxa appeared in Korea. Useful plants of this area were investigated 373 taxa. It corresponds to 82.7% of collected plants in this area under our study. Among the useful plants, there are 191 taxa of edible source, 181 taxa of pasture source, 153 taxa of medicinal source, 54 taxa of ornamental source, 18 taxa of timber. Korean endemic plants were composed 10 families, 13 genera, 9 species, 4 varieties and totaling 13 taxa.

• Journal of dental hygiene science
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• v.9 no.4
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• pp.369-374
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• 2009

The purpose of this study was to survey Korean soldiers' oral healthcare practice and attitudes along with their stress level, and thereby to identify possible correlations among those factors. The survey was conducted from June 11 to Oct. 10, 2008 in G-gun, Chungbuk. province for soldiers. The questionnaire was consisted of the oral healthcare practice and attitude, stress level. As a result, it was found that our respondents scored 3.55 out of possible 9 point in their stress level, which indicated that they had relatively low stress on the whole. According to survey on their oral healthcare practice and attitude depending on their general characteristics, it was found that the higher academic career was associated directly with the more practices of oral healthcare, and nonsmoking group showed more practices of oral healthcare than smoking group. It was found that 'schoolwork and workplace' and 'sexual problem' were critical stress factors on our respondents' oral healthcare attitudes. And it was also found that 'outward appearance complex', 'personality complex', 'conflicts with parents' and 'sexual problem' were critical stress factors on their oral healthcare practices. Since our soldiers' maintenance of their oral healthcare is beneficial to both individual and national aspects, it is necessary for interested parties including dental surgeons to make efforts to develop a promotional program for military dental healthcare project and provide a series of reorientations for soldiers, so that they can have more positive oral healthcare practices and attitudes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.511-525
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• 2014

Goal of this study is estimating of validity of calculated vertical diffusion coefficient for Masan bay is semi-enclosed bay by using eco-hydrodynamic model that is used to analysis of physical structure of coastal waters and calculates the vertical diffusion coefficient. physical structure of coastal waters is calculated by EFDC model, vertical diffusion coefficient calculated as the density gradient is bigger, the vertical diffusion coefficient as density gradient is increases, the vertical diffusion coefficient is decreased. Validity of vertical diffusion coefficient estimated by reproducibility of concentration of dissolved oxygen that calculated in ecosystem model is constructed by Stella program. The Results of model in 2008~2009 were $R^2$ value of 2008 is 0.529~0.700 and $R^2$ value is 0.542~0.791. This results were similar to observed data and simulated to hypoxia at that time. The 'vertical diffusion coefficient' represents stratification and physical stable of a water body, and will be useful for prediction of Hypoxia outbreak.