• Title/Summary/Keyword: 이화학적 요인

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뽕밭의 생산성의 저해 환경요인과 대책

  • 이원주
    • Journal of Sericultural and Entomological Science
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    • v.35 no.2
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    • pp.145-148
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    • 1993
  • 생산성 저해 요인의 제거는 바로 생산성 향상으로 연결된다. 뽕밭의 생산성을 저해하는 요인은 여러가지지만 그 중에서 토양의 이화학적 불량과 농약 공해가 비중이 가장 크다고 볼 수 있다. 우리나라 뽕밭은 입지가 경사지에 많으므로 토심이 얕은데 비해, 뽕나무는 영년성 심근성 작물이므로 식재후 근권의 물리성에 따라 생산성이 좌우되는 비중이 매우 크다. 그러나 식재후 토양 물리성 개량은 화학성 개량보다도 어려우므로 그 결과 생산성이 낮은 상태를 벗어날 수 없다. 따라서 정기적인 심경이나 심토 파쇄를 통한 물리성 개량이 요망된다. 계속적인 금비위주의 비배관리에 의해 강산성 반응을 보이는 토양이 대부분이므로 석회에 의한 산성개량이 필요하다. 질소질의 과다시비는 수량을 감소시킬 뿐만 아니라, 엽질을 악화시키고 질산태 질소가 지하로 흘러 들어가 지하수의 오염을 일으켜 청색증과 암을 일으키는 원인이 될 수 있다. 심각한 정도로 축적된 인산과 칼리도 수량을 떨어뜨리고 환경을 해치는 원인이 되므로, 축적 양분의 재활용에 대한 연구가 계속되어져야 한다. 특히 사용의 편리성 때문에 고농도의 복합비료 위주의 비배관리가 반복되고 있는 실정이므로 토양검정을 받아서 단비를 이용하여 적정한 시비를 해야 할 것이다. 이러한 방법은 생산성의 향상, 영농비의 절감, 공해의 유발을 억제하는 여러가지 효과가 있다. 농약과 산업공해로부터 양잠의 보호를 위해서는 안전지대에 잠업의 단지화, 인근 농과와의 대화를 통해서 양잠에 안전한 농약을 사용토록 하는 한편, 연구분야에서는 심도 있는 연구를 통해 양잠농가를 보호할 수 있는 대책의 수립이 요망되고 있다. 종합해서 말하자면 연구기관의 심도있는 연구가 더욱 활발히 이루워져야 할 것이며, 농민은 개발된 새기술에 보다 깊은 관심을 갖고 활용하는 한편, 필요로 하는 기술을 연구기관에 개발을 요청할 정도의 적극적인 자세가 요구된다. 또한 연구기관의 농민의 중간 교량역할을 하는 지도부문에서도 보다 적극적인 활동이 요청된다.

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Distribution Characteristics of Largemouth Bass (Micropterus salmoides) as an Exotic Species, in Some Medium-to-Large Size Korean Reservoirs and Physico-chemical Water Quality in the Habitats (국내 중대형 인공호에서 외래종인 배스(Micropterus salmoides)의 분포 특성 및 서식지의 이화학적 수질)

  • Kim, Hyun-Mac;Kil, Ji-Hyon;Lee, Eui-Haeng;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.46 no.4
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    • pp.541-550
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    • 2013
  • The objective of this study was to understand the distribution characteristics of largemouth bass as an exotic species in relation to water chemistry. The survey was conducted in 10 reservoirs in Korea that showed different properties in size, location and eutrophic state. Total number of fish species observed in the artificial reservoirs was 52 (13 family) and the relative abundance of the bass was 13% of the total, which is the third dominant species in the whole sample. The relative abundance of bass was the highest in the Pyungtak reservoir (60%), whereas the Daechung reservoir showed the lowest abundance (only 3%). Although no significance difference statistically were founded in the relationship between bass abundance and water quality parameters. The reservoir trophic state showed some relationships. As result, the higher abundance was observed in hypertrophic reservoirs that located in the esturine regions compared to other large and medium reservoirs classified as meso- or eutrphic state. In conclusion, bass distribution in the reservoir ecosystem can not be directly explained by water chemistry only but other environmental factors should be considered.

Validation of Short Form Age Integration Scale and Relationships between Socio-Demographic Characteristics and Age Integration: A Comparison of Age Groups (단축형 연령통합척도 타당화 및 인구사회학적 특성과 연령통합인식 관계: 연령집단 간 비교)

  • Chung, Soondool;Lim, Jeungsuk
    • 한국노년학
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    • v.40 no.1
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    • pp.73-89
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    • 2020
  • This study validates an abridged version of the age integration scale by Chung et al. (2015), which constitutes sub-dimensions of age flexibility and age heterogeneity-from Riley et al. (1994)-and observes disparities in the perception of age integration among different socio-cultural characteristics. This study analyzed 1,433 people in the "Age Integration and Generation Integration Survey" data, with the support of the Social Science Competency Enhancement Project (SSK) (supported by the Korea Research Foundation). This paper analyzed the data using exploratory factor analysis, confirmatory factor analysis, multiple-group factor analysis, and a compare means test. The results are as follows. First, the scale was abridged to 13 items from 28, of which eight items concern age heterogeneity and five concern age flexibility. Second, the multi-group analysis did not show a significant difference among younger, middle, and older age groups, therefore allowing the scale to be used among all age groups. Third, when sociocultural characteristics were observed, younger adults showed differences in their levels of age integration, age heterogeneity, and age flexibility regarding their residential area. Middle-aged adults showed dif f erences in their levels of age integration, age heterogeneity, and age flexibility regarding their residential area and social status. Older adults showed differences in their level of age integration regarding their residential area, education level, and social status. They also showed differences in the level of age flexibility regarding their residential area and social status and differences in the level of age heterogeneity regarding their residential area and education. Based on the results of the study, political and practical measures to promote perception on age integration in the future were suggested.

Diagnosis of Sapkyo Stream Watershed Using the Approach of Integrative Star-Plot Area (생태평가모형(Integrative Star-Plot Area)을 이용한 삽교천 수계 진단)

  • Kim, Ja-Hyun;Yeom, Dong-Hyuk;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.43 no.3
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    • pp.356-368
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    • 2010
  • In this study, we applied approach of integrative star-plot area (SPA), chemical water quality and habitat conditions (QHEI) to diagnoze ecological conditions at the eight sampling sites of Sapkyo Stream. These outcomes were compared with biological health based on the Index of Biological Integrity (IBI) using fish assemblage. And then, we evaluated the integrative ecological health condition using the star-plot method. This approach based on the sum of all the star-plot areas over these water and habitat characteristics. It was developed to reflect an integrative assessment of the ecological health in the stream. The biological health, based on the model values of IBI indicating "fair-poor" condition according to the criteria. Physical habitat health, based on the QHEI, averaged 123 indicating a "good-fair" condition. Also, chemical health, based on simply BOD values indicating "poor grade" according to the criteria of the Ministry of Environment Korea (MEK). The SPA indicating that 50% of the all was impaired condition and the most sampling sites were downstream sites influenced by the point and non-point sources. Overall our results suggest that the ecological health impact was a combined effect of eutrophication and habitat degradations in the stream. The approach of SPA can be used as a tool to evaluate the integrative health of stream environment and to identify possible causes of observed effects.

The Effect of Psychological Factors on Caregiver Burden and Depression of Spousal Caregivers (배우자 부양자의 심리적 요인이 부양부담과 우울에 미치는 영향)

  • Choo Yon Hong;Min Hee Kim;Bang Hee Jung
    • Korean Journal of Culture and Social Issue
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    • v.18 no.3
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    • pp.367-387
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    • 2012
  • The purpose of the current study was to examine the effect of psychological factors on caregiver burden and depression among Korean spousal caregivers. 142 spousal caregivers (89 wives, 52 husbands) in Seoul and Incheon City were surveyed to determine the influence of objective factors of the care recipient, demographic of the caregiver, personality dimensions of extroversion and neuroticism of caregiver, social support, and pre-caregiving marital satisfaction on caregiver burden and depression of spousal caregivers. Hierarchical regression was used to determine the influence of the various factors on caregiver burden and depression. Finding suggest that care recipient's activities of daily living(ADL) and caregiver neuroticism predicted caregiver burden, whereas pre-caregiving martial satisfaction and caregiver neuroticism predicted depression. In particular, psychological factors were better predictors of caregiver burden and depression compared with objective factors. Based on the results, the implications, interventions, limitations and future directions for research were discussed about the psychological factors on spousal caregiving.

Seasonal Variation of Primary Productivity in Gangjin Bay (강진만 일차생산력의 계절변화)

  • 주현수;김성호;이우범
    • Korean Journal of Environmental Biology
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    • v.20 no.2
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    • pp.146-151
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    • 2002
  • The primary productivity and physicochemical factors were surveyed seasonally in Gangjin bay from February to October in 1998. The determination of the Primary Productivity Was performed in Situ by isotope-method using NaH/sup 14/CO/sub 3/. The range of primary productivity was 2.78 mgC m/sup -3/ hr/sup -1/-4.92 mgC m/sup -3/ hr/sup -1/ according to seasons. The primary productivity showed the highest value in summer, followed by those of winter, autumn and spring. The primary productivities of station 1, 2 which are located the upper area, were lower than those of station 3, 4, 5 and 6. The correlations showed that the primary productivity correlated with chlorophyll a, underwater light intensity but reversely correlated with suspended solids. These results suggested that the primary productivity in Gangjin Bay was mainly influenced by the inflow of freshwater from Tamjin River.

Influences of Sugar Substitutes on the Physicochemical and Sensory Properties and Hardness of Baksulgi during Storage (대체감미료 사용이 백설기의 이화학적·관능적 특성 및 저장 중 경도변화에 미치는 영향)

  • Ryu, Dayeon;Kim, Dan Bi;Lee, Kyung Hwan;Son, Dong Sung;Surh, Jeonghee
    • Korean Journal of Food Science and Technology
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    • v.44 no.5
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    • pp.568-576
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    • 2012
  • Baksulgi with various sugar substitutes was prepared and characterized for physicochemical and sensory qualities. The 10% sugar in a control baksulgi was replaced with 16.1% glucose, 13.3% erythritol, 10.2% xylitol, 0.2% stevioside (enzymatically modified stevia 100%), 0.05% aspartame, or 1.2% sucralose. Instrumental and sensory analyses indicated that the baksulgi with glucose was significantly different in color from the others, which was attributed to high susceptibility to browning reaction of the glucose. Baksulgi with aspartame showed significantly lower pH than that of control baksulgi, suggesting that the aspartame might have been hydrolyzed into its constituent amino acids under elevated steaming temperature. A sensory evaluation revealed that baksulgi with sucralose or xylitol was comparable to the control baksulgi in all sensory characteristics. However, the baksulgi with sucralose showed appreciably increased hardness with increased storage time at $4^{\circ}C$, partially due to the anhygroscopic property of sucralose.

Optimization of Goat Milk Yoghurt Preparation Conditions by Response Surface Methodology (반응표면 분석에 의한 산양유 요구르트의 제조조건 최적화)

  • Ham, Jun-Sang;Jeong, Seok-Geun;Shin, Ji-Hye;Choi, Mi-Young;Han, Gi-Sung;Chae, Hyun-Seok;Yoo, Young-Mo;Ahn, Jong-Nam;Ko, Sang-Hyun;Park, Kwang-Wook;Choi, Seok-Ho;Lee, Wan-Kyu
    • Food Science of Animal Resources
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    • v.27 no.3
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    • pp.345-350
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    • 2007
  • This study was carried out to establish the optimal preparation conditions of yoghurt made from goat milk with reduced goaty flavor by adding citrus concentrate and flavor. A central composite design was applied to investigate the effects of citrus concentrate ratio (0.5, 1.0, 1.5, 2.0, 2.5%), citrus flavor ratio (0.01, 0.02, 0.03, 0.04, 0.05%) and fructose ratio (3, 4, 5, 6, 7%). The physico-chemical and sensory characteristics of the sixteen yoghurt samples were compared. The addition of citrus concentrate had a significant (p<0.01) effect on the pH, $a^*,\;and\;b^*$ values. Regarding organoleptic properties, the addition of citrus concentrate had a significant (p<0.01) effect on color, and fructose had an effect on overall palatability. The maximum value of organoleptic goaty flavor was 2.35, more than double the minimum value. The optimum conditions predicted for minimizing goaty flavor of the yoghurt were 1.44% citrus concentrate, 0.0357% citrus flavor, and 6.91% fructose.

Physicochemical and Sensory Characteristics of Snack Using Cham chwi(Aster scaber) (참취를 이용한 스낵제품의 이화학적 및 관능적 특성)

  • Lee, Jong-Mee;Chung, Hye-Jung
    • Journal of the Korean Society of Food Culture
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    • v.14 no.1
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    • pp.49-55
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    • 1999
  • This study was to investigate the physicochemical and sensory characteristics of snack with various amounts Cham chwi and oil. This result was used to determine the optimum condition of adding levels of Cham chwi and oil. Flavor, crispness, greasiness, oil absorption, expansion rate were selected as the physicochemical and sensory characteristics to determine the optimum conditions of the amount of Cham chwi and oil. The predicted values were obtained by the regression method of RSM(response surface methodology). Conditions were standardized with maximum range of expansion rate when expected value of crispness was more than five and expected value of greasiness was less five. The optimum conditions of Cham chwi snack was established as the 8.6% of Cham chwi and 7.6% of oil.

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Changes on the Physicochemical Factor of Stream Water by Medium and Small type Fish Farm in Mt. Baegun Area (백운산 지역내 중소형 양어장에 의한 계류수의 이화학적 요인의 변화)

  • Park, Jae-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.3
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    • pp.43-52
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    • 2005
  • Evaluations of the fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research influent, effluent water in the fish farm and stream water qualities around Mt. Baegun area were monitored seasonally for six years and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Also, effluent water from the fish farm increase of EC higher than influent and stream water. As a result of regression analyses, pH, EC, DO, water temperature, total amount of cation and anion in influent and effluent water of fish farm show high significance.