• Title/Summary/Keyword: On Demand

Search Result 15,177, Processing Time 0.048 seconds

Environmental Pollutants in Streams of Andong District and Insect Immune Biomarker (안동지역 하천의 환경오염물질과 곤충면역 생체지표 분석)

  • Ryoo Keon Sang;Ko Seong-Oon;Cho Sunghwan;Lee Hwasung;Kim Yonggyun
    • Korean journal of applied entomology
    • /
    • v.44 no.2
    • /
    • pp.97-108
    • /
    • 2005
  • Samples of water, soil, and sediment were taken from 10 streams near Andong, Korea in May 2004. To assess the degree of environmental pollution of each stream, chemical pollutants such as total notrogen (T-N), total phosphorus (T-P), chemical oxygen demand (COD), heavy metals, organophosphorus pesticides, organochlorine pesticides, and dioxin-like PCB congeners were analyzed by standard process tests or U.S. EPA methods. In addition, biomarkers originated from insect immune systems of beet armyworm, Spodoptera exigua, were used to analysis of the environmental samples. Except Waya-chun stream showing T-N content of 9.12 mg/L, most streams were contaminated with relatively low levels of overall pollutants in terms of T-N, T-P, and COD, compared to their acceptable environmental levels designated by the Ministry of Environment. Contents of Pb and Cd in samples of each stream were much lower than environmentally permissible levels. However, several times higherconcentrations of Pb and Cd were found in locations at Mi-chun, Kilan-chun, and Hyunha-chun streams, in comparison with other streams. Diazinon, parathion, and phenthoate compounds among organophosphorus pesticides were detected as concentrations of 0.19, 0.40, and $1.13\;{\mu}g/g$, respectively, from soil sample collected in the vicinity of Mi-chun stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners, known as endocrine disrupting chemicals, selected in this study were not found above the limit of detection. Biomarker analyses using insect immune responses indicated that Waya-chun stream was suspected as exposure to environmental pollutants. Limitation and compensation of both environmental analysis techniques are discussed.

Changes in Growth and Physiological Characteristics of Tetradium daniellii (Benn.) T. G. Hartley Container Seedlings by Shading Treatment (차광처리에 따른 쉬나무 용기묘의 생장 및 생리적 특성 변화)

  • Choi, Kyu Seong;Sung, Hwan In;Kim, Jong Jin;Song, Ki Seon
    • Journal of Bio-Environment Control
    • /
    • v.29 no.2
    • /
    • pp.130-140
    • /
    • 2020
  • This study was conducted in order to closely examine about optimum shading for superior seedling production a container seedling of Tetradium daniellii, which is being increased the demand for a seedling due to being used for alternative energy, ecological restoration and honey plant. The experiment of investigating the optimum shading on T. daniellii was carried out by using plastic container types (350 ml/cavity) for the forestry facility cultivation. The shading level was treated with full sunlight and with 35%, 55%, 75% of the full sunlight. As a result of having surveyed height and root collar diameter growth of a containerized seedling in T. daniellii, a case of the shading experiment showed a noticeably high value was indicated in the full sunlight. It was surveyed that the stronger shading level leads to the lower growth value. Root development was most active in full sunlight. Dry matter production, it was investigated to be the highest in full sunlight. It was surveyed to be the similar tendency to the outcome of height and root collar diameter growth. QI, which is index of showing the quality of a seedling, stood at 0.98 in full sunlight, thereby having been investigated to be the highest. As for the chlorophyll content in a seedling, the highest chlorophyll content was indicated in the 75% shading treatment with the relatively highest shading level. The photosynthetic rate and the water use efficiency were surveyed to be the highest in full sunlight with 8.48 μmolCO2·m-2s-1, 1.40 μmolCO2·mmolm-1H2O, respectively. As a result of surveying the whole experiment, optimum shading level for superior seedling production a container seedling of T. daniellii is determined in full sunlight (0%). It is expected that this will be used as a basic data for mass production.

Characterization of a new commercial strain 'Goni' by intra-specific hyphal anastomosis in Pleurotus ostreatus (계통간 교잡에 의한 백색느타리 품종 '고니'의 육성 및 그 특성)

  • Yoo, Young Bok;Lee, Sang Cheol;Kim, Eun Jung;Kong, Won Sik;Jang, Kab Yeul;Shin, Pyung Gyun
    • Journal of Mushroom
    • /
    • v.7 no.3
    • /
    • pp.130-134
    • /
    • 2009
  • To develop new white variety of Oyster mushroom, all white varieties which have been collected and kept in the lab were revived and screened their cultural characteristics. 84 intra-specific Oyster mushroom hybrids between the white-colored mutants Suhan and Wonhyeong were developed using hyphal anastomosis technique in 2007. The Po2007-63 ($2842-7{\times}0205-7$) was shown the best cultural characteristics, selected to be a new variety and named as 'Goni'. The new commercial strain, 'Goni' has white pilei and grows well under spring and autumn conditions in Korea. The fruiting bodies of 'Goni' are of an excellent quality in that not only the stipe is thick and long but also the pileus is small and hard. The optimum temperatures for mycelial growth and fruiting body development were $25-30^{\circ}C$ and $10-16^{\circ}C$, respectively. Time period required for the initiation of the first fruiting body is about 3 to 5 days depending on the temperatures. The shape of fruiting body is thin funnel shape. Fruiting body production per bottle was about $91{\pm}13$ g which is almost 97% quantity compared to that of other variety 'Miso'. Relatively low temperature incubation ($11^{\circ}C$) resulted in the development of better quality of 'Goni' mushrooms. When two different media including potato dextrose medium and mushroom complete medium were compared, the growth of mushroom were much faster in mushroom complete medium at $20-25^{\circ}C$, but not at $25^{\circ}C$. Similar results were observed with other variety 'Miso'. Analysis of the genetic characteristics of the new commercial strain 'Goni' showed a major DNA profile as that of the parental Suhan when primer URP 1 was used, but different to 'Miso' that was used as a control. When screens were performed with primer URP 2, DNA patterns were similar both to that of the parents and 'Miso'. This new variety of the white Oyster mushroom has a clean and fresh image that corresponds well to "health food". We therefore expect that this new strain will satisfy the consumers demand for variety and excellent mushrooms.

  • PDF

Development of Economic Culture System Using Wastewater for Microalgae in Winter Season (폐수를 이용한 겨울철 경제적 미세조류 배양 시스템의 개발)

  • Lee, Sang-Ah;Lee, Changsoo;Lee, Seung-Hoon;An, Kwang-Guk;Oh, Hee-Mock;Kim, Hee-Sik;Ahn, Chi-Yong
    • Korean Journal of Environmental Biology
    • /
    • v.32 no.1
    • /
    • pp.58-67
    • /
    • 2014
  • The outdoor mass cultivation is not possible for microalgae in Korea all year round, due to cold winter season. It is not easy to maintain proper level of productivity of microalgae even in winter. To prevent a drastic decrease of temperature in a greenhouse, two layers were covered additionally, inside the original plastic layer of the greenhouse. The middle layer was made up of plastic and the inner layer, of non-woven fabric. Acrylic transparent bioreactors were constructed to get more sunlight, not only from the upper side but also from the lateral and bottom directions. In winter at freezing temperatures, six different culture conditions were compared in the triply covered, insulated greenhouse. Wastewater after anaerobic digestion was used for the cultivation of microalgae to minimize the production cost. Water temperature in the bioreactors remained above $10^{\circ}C$ on average, even without any external heating system, proving that the triple-layered greenhouse is effective in keeping heat. Algal biomass reached to 0.37g $L^{-1}$ with the highest temperature, in the experimental group of light-reflection board at the bottom, with nitrogen and phosphorus removal rate of 92% and 99%, respectively. When fatty acid composition was analyzed using gas-chromatography, linoleate (C18 : 3n3) occupied the highest proportion up to 61%, in the all experiment groups. Chemical oxygen demand (COD), however, did not decrease during the cultivation, but rather increased. Although the algal biomass productivity was not comparable to warm seasons, it was possible to maintain water temperature for algae cultivation even in the coldest season, at the minimum cost.

A Study on Physical Properties About Velvet Antler of the Elk(Cerus canadensis) (엘크 녹용의 물성 특성에 관한 연구)

  • Sung, S.H.;Han, J.H.;Kim, Y.M.;Kim, B.K.
    • Journal of Animal Environmental Science
    • /
    • v.13 no.3
    • /
    • pp.201-210
    • /
    • 2007
  • In this study, physical properties of Elk antler was investigated to develop the optimum drying and packaging methods for improving the antler quality as well as deal with diversify of demand. After the antler was sliced with 5 mm thickness, and the compressive, shear, and tensile stresses were measured at the center and velvet parts of pre-dried and dried antlers after the contained water rate of the dried antlers was maintained below 10%. The results are as follows. 1. Considering the center of pre-dried antlers, the compressive stresses were $60.73\;g/mm^2$, $145.65\;g/mm^2$, and $260.97\;g/mm^2$, respectively at the upper, middle, and lower parts while $70.67\;g/mm^2$, $811.90\;g/mm^2$, $3,235.52\;g/mm^2$, respectively for velvet layer. Considering the center of dried antlers, the compressive stresses were $190.43\;g/mm^2$, $445.81\;g/mm^2$, and $705.86\;g/mm^2$, respectively at the upper, middle, and lower parts while $734.01\;g/mm^2$, $1,238.40\;g/mm^2$, $4,134.03\;g/mm^2$, respectively for velvet layer. 2. For the pre-dried, the shear stresses were $50.24\;g/mm^2$, $294.44\;g/mm^2$, and $423.47\;g/mm^2$, respectively, and $124.14\;g/mm^2$, $367.69\;g/mm^2$, and $425.86\;g/mm^2$, respectively for the dried antlers. 3. The tensile stresses were $13.59\;g/mm^2$, $62.85\;g/mm^2$, and $112.07\;g/mm^2$, respectively for the pre-dried and $77.24\;g/mm^2$, $175.87\;g/mm^2$, and $184.06\;g/mm^2$, respectively for the dried antlers. 4. In the case of drying antlers, the physical characteristics of the antlers was. changed such as moisture evaporation, contraction, and surface hardening. For the center part, the changes of the physical characteristics were more significant at the lower part while at the upper part for the velvet layer. 5. The stress changes of Elk antlers was shown very remarkably according to growth point. Moreover, the stress was clearly higher at velvet layer part to the center part, base parts compared to the upper parts.

  • PDF

Structural Behavior of Slab in the Partial Demolition for the Apartment Remodeling (아파트 리모델링을 위한 부분해체에서 슬래브의 구조적 거동)

  • Choi, Hoon;Joo, Hyung Joong;Kim, Hyo Jin;Yoon, Soon Jong
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.16 no.2
    • /
    • pp.19-30
    • /
    • 2012
  • Due to the fact that the social environment is improved and the urban development is stabilized, the demand of new construction of apartment becomes slowdown. Accordingly, there are many researches to lengthen the service life of the existing apartment through the remodeling and its importance is continuously rising. However, reliable design specifications and guidelines for the design of remodeling with partial demolition are not provided yet in Korea. Specially, in the apartment remodeling, slab collapse accidents take major portion in all accidents that reported by Korean Government. It is very important to prevent intial crack of slab because intial crack could cause severe accident like collapse of all structure in a short period of time. The purpose of this study is to develop structural guidelines that could guarantee the structural safety and serviceability of slab structure and could be adopted in Korean remodeling with partial demolition. There are mainly two components to determine structural behavior of slab structure. One is the shape of slab structure and the other is load which is resisted by the slab structure. In this study, the weight per unit volume of concrete debris and concrete strength are estimated through the analysis of previous researches to recognize the relationship between the shape of slab and load that loaded on the slab. Accordingly, approximately 300 pieces of floor plan are collected and analyzed. The finite element analysis is conducted using these analyzed and estimated results. From the finite element analysis results, the limited stacking height of debris is suggested and the stacking method is also discussed. In addition, to find the relationship between movement of demolition equipment and structural behavior of slab, the static and dynamic loading tests are conducted. From the results of loading tests, the impact factor which will be considered in the remodeling design could be estimated.

Bacteriological and Physiochemical Quality of Seawater and Surface Sediments in Sacheon Bay (사천만의 해수 및 표층 퇴적물의 세균학적 및 이화학적 특성)

  • Park, Jun-Yong;Kim, Yeong-In;Bae, Ki-Sung;Oh, Kwang-Soo;Choi, Jong-Duck
    • Journal of agriculture & life science
    • /
    • v.44 no.2
    • /
    • pp.7-15
    • /
    • 2010
  • This study was conducted to investigate the bacteriological and physiological quality of seawater and surface sediments in Sacheon Bay of Korea from January to September in 2009. During the study period, the means of temperature was range from 5.3 to $24.9^{\circ}C$ (mean $17.7{\pm}0.4^{\circ}C$), transparency range from 1.4 to 2.5 m (mean $1.8{\pm}0.5m$), suspended solid ranged from 16.2 to 35.8 mg/L (mean $24.2{\pm}2.2mg/L$), chemical oxygen demand ranged from 1.42 to $3.29mgO_2/L$ (mean $2.06{\pm}0.55mgO_2/L$), dissolved oxygen ranged from 6.7 to 9.5mg/L (mean $7.9{\pm}0.6mg/L$), respectively. Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often cause by pathogenic microorganism originating from fecal contamination, such as Salmonella sp., Shigella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefor, data on fecal coliform are very important for evaluating the safety of fisheries in coastal areas. So, we investigated the sanitary indicate bacteria. In this study, 56 sea water samples were collected from the Sacheon Bay, and total and fecal coliforms were compared and analyzed. The coliform group and fecal coliform MPN's of sea water in Sacehon Bay were ranged from <1.8~7,900 MPN/100mL (GM 214.7 MPN/100mL) and <1.8~330 MPN/100mL (GM 9.7 MPN/ 100mL), respectively. Total coliforms were detected in 75.0% of the samples and 76.2% of the total coliforms were fecal coliforms. During the study period, the means of water content, ignition loss, COD, and acid volatile sulfates in sediments in Sacheon Bay were $53.28{\pm}2.58%$, $9.38{\pm}0.42%$, $14.23{\pm}3.36mgO_2/g$, $0.09{\pm}0.07mgS/g$, respectively.

The Communication Repair Strategy Characteristics According to Communication Breakdown of Elderly Man With Alzheimer's Dementia (알츠하이머 치매 노인의 의사소통 단절에 따른 의사소통 회복전략 특성)

  • Kim, Sun-Young;Park, Hee-June
    • Therapeutic Science for Rehabilitation
    • /
    • v.8 no.4
    • /
    • pp.53-63
    • /
    • 2019
  • Objective : Many communication recovery strategies should be used when communication breakdowns occur for successful communication, however, communication problems increase due to inadequate use of such strategies in older people with dementia. The purpose of this study was to investigate the difference of recovery strategy between dementia and the elderly in conversational discourse. Method : The subjects were eight of Alzheimer's dementia and 10 general elderly. Conversation discourse tasks were conducted face-to-face with the subjects. Communication breakdown and communication recovery strategies were analyzed based on 200 utterances collected in the conversation discourse. Result : First, the AD group had more communication breakdown than the control group, but the recovery rate did not differ between the groups. Second, in the AD group, the nonspecific recovery strategy and the clarification demand strategy were used as the expression strategy. The recovery rate after using expressive strategy was more than 90% in explanation strategy, combined strategy, nonspecific repair strategy, and repetition confirmation strategy. The response strategy used a lot of paraphrase strategy and combined strategies, and the recovery rate after using the response strategy was 100% for the simplification strategy, repeat strategy and gesture strategy. Conclusion : The AD group showed more breakdown of research subjects and breakdown of researchers than control group, and it showed ability to use various expression strategy and response strategy though there was difference in repair rate between communication repair strategy. AD group used nonspecific repair strategy in expression strategy the most and paraphrase strategy in response strategy the most. This shows different characteristic from ordinary elderly people. Therefore, it is necessary to utilize this repair strategy for rehabilitation of AD elderly.

A Cohort Study of Mental, Physical and Behavioral Impacts of Early(at Age 55) Compulsory Retirement in Korea (조기 정년퇴직자의 정신. 육체. 행위적 경향연구)

  • Duk-Sung Kim;Sae-Kwon Kong;Kong-Kyun Ro
    • Korea journal of population studies
    • /
    • v.11 no.1
    • /
    • pp.204-229
    • /
    • 1988
  • This paper documents and discusses trends and differentials in youth's participation in the labor force and employment. Youth in this study is defined asthe young aged 15-29. Youth passes through a series of life-course transitions,which include school completion own family formation(marriage and childbirth) .mandatory service in the army (by males) , and their economic activities are affectedby those life-course events. Accordingly we show how and to what extent youth'slabor force participation and employment varies with age and how the age patternhas changed over time.Throughout the 1980's and 1990's, youth's labor force participation showeddifferent trends by age group Labor fDrce participation rate of the 15-19 agedsteeply decreased, while that of the 25-29 steadily increased during the twodecades, the rate fsr the 20-24 aged showing not much variation. The former is dueto the increased rate of school enrollment among the age group, while the lattercould be attributed, in part, to the young women s increased and more steadyparticipation in the labor force over time.While labor force participation could be considered as a result of one's choicesand preferences, employment opportunities are more or less restricted by labormarket structure and institutions . This study documents how the structuralconstraints have interacted with individual and group attributes to differentiateemployment opportunities between individuals (educational background) and groups(especially sex diffrences) . One of the most salient feature of youth's em[ploymentstructure is the recent high unemployment rate of the college graduates. We discusshow that is related to the'credential society'in which one's educational credentials and it's social status play major role in determining who gets what in terms of job opportunities. Also is discussed the discordance between school and labor marketsupply and demand system, which is apparent in the prolonged oversupply of thecollege graduates, which is due to the consistently high rate of college entranceobserved since the early 1980's. Theoretically the job market for college graduates isviewed not as the'neoclassical'wage competition market but as job competition market in which one's (good) job opportunity is determined by one s position in thejob queue, which is in turn heavily dependent on from which college one get shis/her college degree as well as one's sex.

  • PDF

Fertility Status in Northeastern Alpine Soils of South Korea with Cultivation of Vegetable Crops (강원도 고랭지 채소 재배지의 토양 비옥도관리 현황과 전망)

  • Yang, Jae-E.;Cho, Byong-Ok;Shin, Young-Oh;Kim, Jeong-Je
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.34 no.1
    • /
    • pp.1-7
    • /
    • 2001
  • Total upland area for cultivating the vegetable crops in the Alpine soils of Northeastern South Korea has been extending its limit to meet the increasing demand of vegetable food in recent decades. About 70% of these alpine soils are located in over 7% of the slope and most of vegetable crops have been cultivated intensively without practicing the best management systems. Thus, soil erosion and continuous cropping system have degenerated the soil fertility and shown detrimental effects on water quality. We initiated an intensive and extensive investigation to characterize the fertility problems encountered in these uplands. Objectives of this paper were to characterize the fertility status in the Alpine soils cultivated with vegetable crops for many years and to provide the recommendations for adequate soil management measures including fertilization and erosion control. Soils in general have good drainage with textural classes of loam or sandy loam. Their topographical characteristics tended to lead them to shallow plow layers, and the steepness of the terrain created erosion hazard. Of the soils examined, about 11% of uplands over 30% gradient was found in need of an urgent reforestation. A high content of gravel and firm hardness of soil attributed to inhibit the utilization of farm machinery and plant-root development. The average soil pH 5.6 was slightly low relative to pH 5.70 of the national average. Organic matter content was high compared with 2.0% of national average, but decreased with the prolonged cultivation periods. Available $P_2O_5$ concentration was unusually high due to the consequence of over dose application with chemical and organic fertilizers. Exchangeable cations as Ca, Mg, and K were appeared to be decreased in these regions with prolonging the cultivation periods. There were no significant differences in cation exchange capacity (CEC) and electrical conductivity (EC) among locations. Heavy metal contents were mostly lower than the threshold of danger level designated by Soil Environment Conservation Law of South Korea. Results indicated that a proper countermeasure and the best management practice should be immediately implemented to conserve the top soil and fertility in the Alpine regions.

  • PDF