• 제목/요약/키워드: 강도평가법

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Nutritional and Organoleptic Evaluations of the By-products from Chlorella vulgaris after Lipid Extraction (Chlorella vulgaris의 지질 추출 후 부산물의 영양학적 및 관능적 평가)

  • Oh, Sung-Ho;Choi, Woon-Yong;Seo, Yong-Chang;Kim, Ga-Bin;Lee, Shin-Young;Jeong, Kyung-Hwan;Kang, Do-Hyung;Lee, Hyeon-Yong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.6
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    • pp.920-926
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    • 2010
  • Marine alga, Chlorella vulgaris, was extracted by chloroform-methanol (2:1, v/v) solvents for lipid extraction at $35^{\circ}C$ for five hours (HCM-35) and its process was compared with conventional lipid extraction condition such as chloroform-methanol (2:1, v/v) at $65^{\circ}C$ for one hour (CM-65). This low temperature extraction process showed that 80% of total lipid was extracted and its residues contained relatively unchanged amounts of intact proteins and other minerals as well as amino acid profiles. Interestingly enough, the weight fraction of carbohydrate in the residues slightly increased due to less denaturation at low process temperature. The biological activities of the residues such as cytotoxicity and immune cell growth activation were not much changed after being extracted. The sensory evaluation were found to be very favorable for being used as a food additive and/or food supplement. This result could also help to maintain the economic feasibility of utilizing marine resources in food and other relevant industries.

Evaluation of Performance Based Design Method of Concrete Structures for Various Climate Changes (다양한 기후변화에 따른 콘크리트 구조물의 성능중심형 설계 평가)

  • Kim, Tae-Kyun;Shim, Hyun-Bo;Ahn, Tae-Song;Kim, Jang-Ho Jay
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.1 no.1
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    • pp.8-16
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    • 2013
  • Currently, global warming has advanced by the usage of fossil fuels such as coal and petroleum. and the atmosphere temperature in the world of 100 years(1906~2005) has been risen $0.74^{\circ}C{\pm}0.18^{\circ}C$, IPCC announced that the global warming effect of last decade was nearly doubled compared to the changes($0.07^{\circ}C{\pm}0.02^{\circ}C$/10year) in the past 100 years. Moreover, due to the global warming, heat wave, heavy snow, heavy rain, super typhoon, were caused and are increasing to happen in the world continuously causing damages and destruction of social infrastructures, where concrete structures are suffering deterioration by long-term extreme climate changes. to solve these problems, the new construction technology and codes are necessary. In this study, to solve these problems, experiments on a variety of cases considering the temperature and humidity, the main factors of climate factors, were performed, and the cases are decided by temperature and humidity. The specimens were tested in compressive strength test and split tensile test by the curing age(3,7,28 days) morever, performance based design(PBD) method was applied by using the satisfaction curve developed from the experiment date. PBD is the design method that gathers the current experimental analysis and past experimental analysis and develops the material properties required for the structure, and carries out the design of concrete mix, and it is recently studied actively worldwide. Also, it is the ultimate goal of PBD to design and perform on structures have sufficient performance during usage and to provide the problem solving for various situations, Also, it can achieve maximum effect in terms of functionality and economy.

Spatial Analysis of Ecological Characteristics for Benthic Macroinvertebrate Community Structure in Lake Hoengseong Region (횡성호 일대 저서성 대형무척추동물 군집구조의 생태적 특성 분석)

  • Lee, Hwang-Goo;Jung, Sang-Woo;Choi, Jun-Kil
    • Korean Journal of Environment and Ecology
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    • v.26 no.1
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    • pp.46-56
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    • 2012
  • Benthic macroinvertebrates were investigated in Hoeongseong Lake region from March to October 2010, Korea. Macroinvertebrate communities, composition of the functional feeding groups, habitiat oriented groups and the biological water quality were assessed above and below Hoeongseong Dam in the lake region. Six sites, two (St.1~2) above the lake, two (St. 3~4) into the lake, and two (St. 5~6) below the dam, were selected for quantitative (Surber sampler $30cm{\times}30cm$, mesh size 0.2 mm) and qualitative (Hand net) samplings of benthic macroinvertebrates. As a result, a total of 83 species belonging to 43 families, 17 orders, 8 classes, and 5 phyla were recognized. The EPT-group (50 spp. : 60.24%) that is major taxa or EPT-group plus Diptera (61 spp. : 73.49%) occupied most of benthic macroinvertebrates community. Based on quantitative sampling, the number of benthic maroinvertebrates above the lake was 2,399 individuals including 54 species, 28 families, 11 orders, 4 classes, and 4 phyla, whereas 510 individuals including 16 species, 12 families, 7 orders, 4 classes, and 3 phyla in the lake and 626 individuals including 62 species, 33 families, 13 orders, 6 classes, and 4 phyla below the dam were collected respectively. Dominance index was the highest, with 0.82-0.93 ($0.87{\pm}0.05$) in Hoeongseong lake (St. 3-4), diversity index was 3.04-3.16 ($3.10{\pm}0.06$), evenness index was 0.79-0.85 ($0.82{\pm}0.03$), and richness index was 7.27-8.52 ($7.90{\pm}0.63$), which were relatively higher below the dam sites. In the functional feeding groups, collector-gatherers and collector-filterers were the highest in the whole sites, and predators (Micronecta sedula) was appeared highly in the lake. Moreover, swimmers, burrowers, and clingers were considerably occupied in all collecting sites. The result of the DCA, similarity analysis, and MRPP were well reflective of the composition of lake and stream macroinvertebrates. ESB indicate that the lake sites were evaluated heavily polluted under priority improvement waters. Also, Semisulcospira gottschei, Ecdyonurus kibunensis, Epeorus pellucidus, Rhoenanthus coreanus, Stenelmis sp., and Cheumatopsyche brevilineata are considered as an indicator species above and below Hoeongseong Lake, whereas Macrobrachium nipponense and Micronecta sedula are indicated in the lake.

A Feasibility Study on the Deep Soil Mixing Barrier to Control Contaminated Groundwater (오염지하수의 확산방지를 위한 대체 혼합차수재의 적용에 관한 연구)

  • 김윤희;임동희;이재영
    • Journal of Soil and Groundwater Environment
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    • v.6 no.3
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    • pp.53-59
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    • 2001
  • There is a lot of method to manage the insanitary landfill but vertical cutoff walls have been widespreadly used and were installed into the subsurface to act as a barrier to horizontal groundwater flow, The stabilized material such as specialized cement or mixed soil with additives has been generally applied for the materials of the deep soil mixing barrier in korea. The amount of the stabilized material is dependent on the field conditions, because the mixing ratio of the material and the field soil should achieve a requirement in the coefficient of permeability, lower than 1.0$\times$$10^{7}$cm/sec. This study determined the quantity and optimized function ratio of the stabilized material in the formation process of the mixed barrier that was added with stabilized material on the field soil classified into SW-SC under USCS (Unified Soil Classification System). After that the fly ash and lime were selected as an additives an that could improve the function of the stabilized material and then the method to improve the functional progress in the usage of putting into the stabilized material as an appropriate ratio was studied and reviewed. The author used the flexible-wall permeameter for measuring the permeability and unconfined compressive strength tester for compressive strength, and in the view of environmental engineering the absorption test of heavy metals and leaching test regulated by Korean Waste Management Act were performed. As the results, the suitable mixing ratio of the stabilized material in the deep soil mixing barrier was determined as 13 percent. To make workability easy, the ratio of stabilized material and water was proven to be 1 : 1.5. With the results, the range of the portion of the additives(fly ash : lime= 70 : 30) was proven to be 20-40% for improving the function of the stabilized material, lowering of permeability. In heavy metal absorption assessment of the mixing barrier system with the additives, the result of heavy metal absorption was proved to be almost same with the case of the original stabilized material; high removal efficiency of heavy metals. In addition, the leaching concentration of heavy metals from the leaching test for the environmental hazard assessment showed lower than the regulated criteria.

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Effects of Historical and Cultural Landscape Images on Healing Characteristics - Around the Yangdong Village in Gyeongju - (역사문화경관 이미지가 치유특질에 미치는 영향 - 경주시 양동마을을 중심으로 -)

  • Chen, Geng;Lee, Sun-Ho;Yi, Young-Kyoung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.39 no.2
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    • pp.29-38
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    • 2021
  • According to the theory of concentration recovery(ART), experiencing landscapes with healing properties can heal human mental fatigue caused by intentional concentration. The ART illustrates four healing qualities of the landscape. ART admits that various landscapes can have healing properties, the four healing properties of the landscape explained that the greater the perceptual strength, the stronger the healing effect. Until now, research on healing landscapes has been mainly done on natural and urban landscapes. The purpose of this study is as follows. First, eIt is intended to evaluate the healing characteristics of the Yangdong village landscape using RCS and investigate the impact of the healing characteristics on the visiting preference of the target landscape. Second, Evaluating the landscape image of Yangdong Village landscape, Investigating the effect of landscape images on the healing properties of landscape. This study was conducted in Yangdong Village, Gyeongju, 127 college students participated in the survey. SD 16 items to analyze landscape images and RCS 22 items from Laumann(2001) to evaluate healing properties were used as measurement tools. The findings are summarized as follows. First, The landscape image of Yangdong Village was analyzed through SD method, the analysis of the factors of Yangdong Village landscape image results in two factors: place and singularity. Second, It demonstrates the reliability and validity of RCS, Three factors were extracted from the factor analysis results. Third, Landscape images have a positive effect on the three healing characteristics of RCS. Fourth, Three healing properties of RCS have been shown to have a positive effect on visiting preferences, The order of influence on the relative visiting preferences was analyzed as attractiveness, fit, sense of escape, and sense of space. The findings suggest that future work requires research to re-validate the reliability of RCS. It is also necessary to analyze landscape images for various landscape types to specifically understand the effects on healing characteristics.

Tightness of specimen sealing box in 20 L test chamber to evaluate building materials emitting pollutants (건축자재에서 방출되는 오염물질 평가 시 사용되는 20 L 시험챔버 시편홀더의 기밀성 개선)

  • Shin, Woo Jin;Lee, Chul Won;Kim, Man Goo
    • Analytical Science and Technology
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    • v.20 no.4
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    • pp.261-267
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    • 2007
  • The 20 L small chamber test method is to evaluate pollutants such as TVOC, formaldehyde emitted from building materials. This method was only designed to evaluate the surface emission of sample exposed in the chamber. In this method, building materials cut with a fixed standard size are fixed in a sample sealing box. The sample sealing box is put into the 20 L test chamber. This chamber is ventilated at a standard air change rate with purified air for 7 days then the sample from the chamber is collected and analyzed to measure the emission rate of TVOC and formaldehyde. In this method, however, if the sealing box does not guarantee airtightness, accurate evaluation for the building materials can not be achieved due to the pollutants emitted from edge of the sample so called, edge effect. This edge effect can be much greater when evaluating panels such as plywood, flooring due to their surface treatment. In this study, flooring was tested to check airtightness of the sample sealing box with analytic results between 1L and 20 L test chamber. Furniture materials like LPM coated one side surface treatment and MDF coated both sides surface treatment with LPM were tested to identify whether the improvement of the sample sealing box airtightness is possible with the comparison between existing and improved test method that low VOC emission tape was used to seal the sample edge. After 7 days, MDF TVOC emission rate was different according to the existence and nonexistence of tape. The emission rate of the existing test method was $0.009mg/m^2h$ and that of improved test method was $0.003mg/m^2h$. Relative standard deviation for the existing test method was $0.004mg/m^2h$ and relative standard deviation for the improved test method was $0.002mg/m^2h$ when the same sample was analyzed three times. The improved test method in this study using low VOC emission tape was effective and able to reduce the heterogeneous effect of the edge from the sample sealing box.

Antimicrobial Activity of Salvia miltiorrhiza Bunge Extract and Its Effects on Quality Characteristics in Sulgidduk (단삼 추출물의 향균 활성 및 첨가 설기떡의 품질 특성)

  • Choi, Hae-Yeon
    • The Korean Journal of Food And Nutrition
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    • v.22 no.3
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    • pp.321-331
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    • 2009
  • In this study, Salvia miltiorrhiza Bunge(Danshen) powder was extracted with ethanol, and its antimicrobial activity was investigated. The ethanol extract of the Danshen had antimicrobial activity against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. The inhibition zones of the Danshen extract(3 mg/disc) against B. subtilis, E. coli and S. aureus were 13, 12 and 8.5 mm, respectively. To test the food preservation effect of Danshen and determine the optimal ratio of the Danshen extract in a formulation, Sulgidduk samples were prepared with substitutions of 0, 0.25, 0.5, 0.75 and 1% Danshen extract, and then their quality characteristics were investigated over 4 days of storage. According to the results, total cell counts showed a decreasing trend with an increasing amount of added Danshen extract. Moisture contents were not significantly different among the Sulgidduk samples. As the content of Danshen extract increased, the L-values of samples decreased and the a- and b- values increased. For the textural characteristics, the hardness, gumminess, and chewiness of the Sulgidduk samples decreased as the amount of Danshen extract increased; however, they increased with the progression of storage time. In the sensory evaluation, the control group had significantly higher scores for color, flavor and after-taste as compared to the Danshen extract-added groups. With increasing Danshen extract contents, flavor and overall acceptability decreased, while Danshen flavor, bitterness and off-flavor increased. Chewiness was not significantly different among the samples. In conclusion, the results indicate that substituting 0.5% Danshen extract in Sulgidduk is optimal for quality and provides a product with reasonably high overall acceptability.

Effect of Cryoprotectants on Quality Properties of Chicken Breast Surimi (냉동변성방지제의 종류가 닭가슴살 수리미의 품질 특성에 미치는 영향)

  • Jin, S.K.;Kim, I.S.;Kim, S.J.;Jeong, K.J.;Lee, J.R.;Choi, Y.J.
    • Journal of Animal Science and Technology
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    • v.49 no.6
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    • pp.847-856
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    • 2007
  • This study was conducted to determine the effect of cryoprotectants(sugar, sorbitol, polyphosphate) on quality properties of chicken breast surimi manufactured by pH adjustment(pH 11.0) during frozen storage. Final surimi was divided into experimental units to which the following treatments were randomly assigned: C(Alaska pollack surimi, two times washing, 4% sugar+5% sorbitol+0.3% polyphosphate additive); T1(chicken breast surimi, 0.3% polyphosphate additive); T2(chicken breast surimi, 5% sorbitol +0.3% polyphosphate additive); T3(chicken breast surimi, 4% sugar+5% sorbitol+0.3% polyphosphate additive). All amino acid contents of control were higher than those of all treatments, while T2 was higher in amino acid contents among the treatments. Shear force of all treatments were higher than that of control, but the breaking force, deformation and gel strength were lower. The TBARS(thiobarbituric acid reactive substances) and VBN(volatile basic nitrogen) values of all treatments were lower than those of control, The TBARS values of all treatments were increased with increased storage period. In sensory evaluation, the score of appearance, meat color and overall acceptability of control were higher than those of all treatments, but aroma, juiciness and tenderness were lower than those for all treatments.

Nerve Growth Factor and Sensory Neuropeptide Levels in Plasma and Saliva of Various Orofacial Pain Patients (다양한 구강안면통증환자의 혈장 및 타액에서의 신경성장인자와 감각성 신경펩티드 농도에 관한 연구)

  • Jang, Min-Uk;Chung, Sung-Chang;Chung, Jin-Woo
    • Journal of Oral Medicine and Pain
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    • v.34 no.4
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    • pp.387-395
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    • 2009
  • Nerve growth factor (NGF) and sensory neuropeptides are involved in the process of nociception at peripheral nerve fibers and wide spread in central nervous system. The aims of this study were to investigate NGF and sensory neuropeptides (substance P [SP] and calcitonin gene-related peptide [CGRP]) levels in human plasma and saliva, and the associations between these sensory neuropeptides levels and chronic orofacial pain symptoms. NGF, SP, and CGRP levels in plasma and resting whole saliva samples collected from 67 orofacial pain patients (joint pain, dental or periodontal pain, mucosal pain) and 36 pain free control subjects were measured by enzyme immunoassay. The characteristic pain intensity of each subject was measured using the Graded Chronic Pain Scale and the flow rate of resting whole saliva was measured. Joint pain patients group showed significantly higher plasma NGF level compared to each of dental pain patients (p<0.01), mucosal pain patients (p<0.01), and control group (p<0.01). Plasma NGF level of dental pain patients group was significantly higher than that of control group (p<0.01). Saliva SP level of dental pain patients group (p<0.05) and saliva CGRP level of mucosal pain group (p<0.05) were significantly higher than that of control group. Plasma and saliva SP levels of joint pain patients was significantly associated with pain intensity (plasma: standardized coefficient=0.599, p<0.01, saliva: standardized coefficient=0.504, p=0.05). In dental pain patients group, plasma SP (standardized coefficient=0.559, p<0.01), saliva SP (standardized coefficient=0.520, p<0.01) and saliva CGRP (standardized coefficient=0.599, p<0.01) levels were significantly associated with age. In mucosal pain patients group, plasma SP (standardized coefficient=0.495, p<0.05), saliva SP (standardized coefficient=0.500, p<0.05), and saliva CGRP (standardized coefficient=0.717, p<0.01) levels were significantly associated with age. NGF and neuropeptides may play a role in the maintenance of various orofacial pain symptoms. The examination of those levels in plasma and saliva helps understanding the mechanism of orofacial pain, and furthermore, can be applied to the diagnosis and therapy of orofacial pain.

Antimicrobial Activity of Paeonia japonica Extract and Its Quality Characteristic Effects in Sulgidduk (백작약 추출물의 항균효과 및 설기떡의 품질특성에 미치는 영향)

  • Choi, Hae-Yeon
    • Korean journal of food and cookery science
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    • v.25 no.4
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    • pp.435-444
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    • 2009
  • In this study, Paeonia japonica powder was extracted with ethanol, and its antimicrobial activity was investigated. The ethanol extract of the P. japonica had antimicrobial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. The inhibition zones of the P. japonica ethanol extract (3 mg/disc) against B. subtilis, E. coli and S. aureus were 10, 11, 8.5 mm, respectively. To test the food preservation effect of P. japonica and determine the optimal ratio of the P. japonica extract in the formulation, Sulgidduk samples were prepared with substitutions of 0, 0.25, 0.5, 0.75 and 1% P. japonica extract, and the quality characteristics of the samples were then investigated over 4 days of storage. In these experiments, total cell counts tended to decrease as the amount of added P. japonica extract increased. Moisture contents were not significantly different among the Sulgidduk samples. As the content of the P. japonica extract increased, the L-values of the samples decreased and the a- and b- values increased. In regards to the textural characteristics, the hardness, gumminess, and chewiness of the Sulgidduk samples decreased as the amount of P. japonica extract increased; however, they increased with the progression of storage time. Adhesiveness, springiness and cohesiveness were not significantly different at the different P. japonica extract concentrations and decreased with storage time. In the sensory evaluation, the control group had significantly higher scores for color, flavor and after taste as compared to the P. japonica extract added groups. When the P. japonica extract content was increased, the flavor and overall acceptability decreased, while Bakjakyak flavor, bitterness and off-flavor increased. Softness was not significantly different among the samples. In conclusion, the results indicate that substituting $0.25{\sim}1%$ P. japonica extract in Sulgidduk is optimal for quality and provides a product with reasonably high overall acceptability.