• 한국도로학회논문집
• /
• 제13권2호
• /
• pp.139-145
• /
• 2011

최근 10년간 전세계적으로 아스팔트 포장을 재활용하는 기술이 급속도로 확산되고 있으며 노후 아스팔트 포장을 폼드 아스팔트 또는 유화 아스팔트를 사용하여 현장에서 바로 100% 재활용하는 현장 상온 재생 아스팔트 포장기술이 다양하게 적용되고 있다. 특히, 아이오와 주에서는 교통량이 적은 지방도로에서 기존 포장의 수명을 연장 시켜주는 현장 상온 재생 아스팔트 공법을 많이 적용하고 있다. 일반적으로 현장 상온 재생 아스팔트 포장층은 수분의 침투나 교통하중으로부터 보호하거나 포장설계를 만족시키기 위해 가열 아스팔트 포장으로 덧씌우기를 한다. 일반적으로 현장 상온 재생 아스팔트 포장층 위에 가열 아스팔트 포장으로 덧씌우기 할 시기는 대부분에 감독자들은 일정한 양생기간 또는 최대 함수비에 근거하여 결정하고 있다. 따라서, 본 연구에서는 감독자가 최적에 덧씌우기 아스팔트 포장 시기를 결정할 수 있도록 현장 상온 재생 아스팔트 포장층의 현장 함수비를 간단하게 측정하여 덧씌우기 시기를 결정할 수 있는 수분 감소계수를 개발하는 것이다. 먼저, 현장 상온 재생 아스팔트 포장층의 함수비를 TDR 함수량계를 사용하여 측정하였고 현장 상온 재생 아스팔트 포장이 시공되는 기간 동안에 강우량, 대기온도, 습도, 바람속도 등 기상정보를 수집하였다. 마지막으로 현장 상온 재생 아스팔트 포장의 초기 함수비, 대기온도, 습도, 바람속도를 변수로 하는 수분 감소계수를 개발하였다. 실제 현장 상온 재생 아스팔트 포장에서 측정한 값을 사용하여 개발한 수분 감소계수는 감독자가 연속적으로 현장 상온 재생 아스팔트 포장층의 함수비를 측정하지 않고 최적의 덧씌우기 포장 시점을 결정할 수 있다.

• 한국농공학회지
• /
• 제22권3호
• /
• pp.60-74
• /
• 1980

Soil-cement mixtures involve problems in it's durability in grain size distribution and mineral composition of the used soils as well as in cement content, compaction energy, molding water content, and curing. As an attempt to solve the problems associated with durability of weathered granite soil with cement treated was investigated by conducting tests such as unconfined compression test, it's moisture, immers, wet-dry and freeze-thaw curing, mesurement of loss of weight with wet-dry and freeze-thaw by KS F criteria and CBR test with moisture curing on the five soil samples different in weathering and mineral composition. The experimental results are summarized as follows; The unconfined compressive strength was higher in moisture curing rather than in the immers and wet-dry, while it was lowest in freeze-thaw. Decreasing ratio of unconfined compressive strength in soil-cement mixtures were lowest in optimum moisture content or in the dry side rather than optimum moisture content with freeze-thaw. The highly significant ceofficient was obtained between the cement content and loss of weight with freeze-thaw and wet-dry. It was possible to obtain the durability of soil-cement mixtures, as the materials of base for roads, containing above 4 % of cement content, above 3Okg/cm$_2$ of unconfined compressive trength with seven days moisture curing or 12 cycle of freeze-thaw after it, above 100% of relative unconfined compressive strength, 80% of index of resistance, below 14% of loss of weight with 12 cycle of wet-dry and above 1. 80g/cm$_2$ of dry density.

• 한국식품과학회지
• /
• 제29권5호
• /
• pp.932-938
• /
• 1997

Changes in viscosity and dynamic theological properties of Job's-tears were measured by Bohlin dynamic tester as a function of moisture, and measurement was performed within a linear viscoelastic range. The result of the shear stress vs shear rate of Job's-tears at different moisture contents $(50{\sim}75%)$ was applied to mathematical models and Herschel-Bulkley model showed the highest correlation coefficient. Lower moisture content (55%) produced higher yield stress and consistency index, but lower flow behavior index, whereas higher moisture content showed reverse effects. Job's-tears with $50{\sim}70%$ moisture contents showed a higher storage modulus (G') than loss modulus (G') at all frequencies, showing a higher concentrated polymer characteristics. However, higher moisture content (>75%) showed crossover point between G' and G', and frequency dependency. As the moisture content was increased, the amount of viscoelastic properties such as G', G', complex viscosity decreased during heating, and initial temperature and miximum value of viscoelastic properties shifted to higher temperatures, representing the moisture-dependence of Job's-tears upon theological properties.

• 한국축산식품학회지
• /
• 제43권3호
• /
• pp.531-539
• /
• 2023

The objective of this study was to determine the effects of quality grade (QG), and back-fat thickness on the carcass traits and meat quality properties of Hanwoo steers. Fifty carcasses were sorted into two QG (QG 1+ and 1) and three back-fat thickness (<10 mm, 10 to 19 mm and ≥19 mm) groups. After investigating the carcass traits (rib eye, back-fat thickness, weight, color, yield index, maturity, marbling score, and texture), the longissimus lumborum muscles from the carcass groups were collected and analyzed for meat quality (pH, color, cooking loss, and moisture), texture profiles [Warner-Bratzler shear force (WBSF), and tensile tests], and fatty acid. Results showed that marbling score (p<0.001), moisture (p<0.05) and tensile tests values (p<0.05) had a significant differences between QG1+ and QG1. No differences in pH, color traits, cooking loss and WBSF values occurred between the QG groups. Regarding the back-fat thickness effect, we observed that the carcass weight, yield index (p<0.001), yield grade (p<0.001) and marbling score (p<0.05) had a significant differences among the back-fat thickness groups. Regarding the meat quality, moisture content and WBSF values (p<0.01) among the back-fat thickness groups. The back-fat thickness did not affect the pH, color, cooking loss and tensile tests. The QG and back-fat thickness did not affect the fatty acids contents (p>0.05). It may be concluded that the carcass traits and meat quality were significantly affected the QG and back-fat thickness.

• 한방안이비인후피부과학회지
• /
• 제23권3호
• /
• pp.154-164
• /
• 2010

Objective : The purpose of this clinical research was to investigate the effects of herbal cosmetics containing Phellinus linteus extracts on patients with atopic dermatitis. Methods : A total of 35 patients who visited Daegu Hanny Oriental Medical Center from November 4th, 2008 to December 28th, 2008 were included in this study. In this study, we observed transepidermal water loss, skin moisture content, modified scorad index of atopic dermatitis and pruritic degree. Statistical analysis was performed by using paired t-test and wilcoxon signed ranks test. Statistical significance was achieved if the probability was less than 5%(p<0.05). Results : Statistically, herbal cosmetics containing Phellinus linteus extracts showed siginificant effect on transepidermal water loss, skin moisture content, modified scorad index of atopic dermatitis and pruritic degree(p<0.05). And satisfaction after using herbal cosmetics was near good. Conclusions : Considering the above results, we have concluded that herbal cosmetics containing Phellinus linteus extracts have the remarkable effects on atopic dermatitis.

• 한국농공학회논문집
• /
• 제59권6호
• /
• pp.29-37
• /
• 2017

In this study, we analyzed the impacts of land surface characteristics on spatially and temporally distributed soil moisture values at the Yongdam and Soyang-river dam watersheds in 2014 and 2015. The soil moisture, NDVI (Normalized Difference Vegetation Index) and temperature values at the spatio-temporal scales were estimated using satellite-based MODIS (MODerate Resolution Imaging Spectroradiometer) products. Then the Pearson correlations between soil moisture and land surface characteristics (NDVI, temperature and DEM-digital elevation model) were estimated and analyzed, respectively. Overall, the monthly soil moisture values at the time step were highly influenced by the precipitation amounts. Also, the results showed that the soil moisture has the strong correlation with DEM while the temperature was inversely correlated with the soil moisture. However the monthly correlations between NDVI and soil moisture were highly varied along the time step. These findings indicated that water loss near the land surface are highly occurred by soil and plant activities as evapotranspiration and infiltration during the no/less precipitation period. But the high precipitation amounts reduce the impacts of land surface characteristics because of saturated condition of land surface. Thus these results demonstrated that soil moisture values are highly correlated with land surface characteristics. Our findings can be useful for water resources/environmental management, agricultural drought, etc.

• 대한토목학회논문집
• /
• 제26권4B호
• /
• pp.345-354
• /
• 2006

가뭄은 홍수와는 달리 장기적이고 지속적인 피해를 유발하고, 지역의 경제에 타격을 주며, 생태계 및 환경을 파괴하는 자연재해로서 인간에게 오랫동안 고통을 준다. 이와 같은 가뭄에 대비하고 가뭄을 관리하기 위해 가뭄의 정도를 정량화하고자 하는 연구가 꾸준히 이루어져 왔다. 그 결과 다양한 가뭄지수들이 개발되었으며 이들을 이용해 가뭄감시를 수행하고 있다. 그중 Palmer의 가뭄심도(PDSI)가 가뭄감시와 관리를 위하여 가장 널리 사용되고 있음에도 불구하고, 물순환의 고려없이 기후적인 조건만을 이용하는 단점과 한계성이 여러 학자들에 의해 지적되어 오고 있다. 따라서 본 연구에서는 이러한 단점을 극복하기 위해 토양, 토지이용, 기후자료를 입력자료로 하는 준 분포형 장기유출모형인 SWAT모형을 이용하였다. 즉, SWAT 모형을 이용해 토양수(soil water, SW)를 추정하고, 이로부터 계산된 토양수분결핍을 근거로 토양수분지수(soil moisture index, SMI)를 산정하였다. 본 연구에서는 소양강댐 유역에 대해 SWAT 모형을 적용해 구한 토양수분지수와 PDSI를 비교 분석하였다. 즉, 소양강댐 지점의 일유입량 자료를 이용해 SWAT모형을 보정하고 검정하여, 장기 일 토양수를 추정하고, SWAT모형을 통해 모의된 토양수로부터 계산된 토양수분 결핍을 근거로 토양수분지수를 산정하였다. 본 연구를 통해 SWAT 모형의 적용성을 검토한 결과, 결정계수가 0.651로서 비교적 좋은 결과를 보였고, GIS를 이용함으로서 보다 향상된 해상도를 가지고 가뭄감시를 할 수 있었다. 따라서 본 연구에서 제안한 토양수분결핍에 기초한 토양수분지수는 가뭄감시와 관리를 위해 적용이 가능하리라 판단된다.

• 한방안이비인후피부과학회지
• /
• 제33권4호
• /
• pp.1-15
• /
• 2020

Objectives : To investigate aggravating and mitigating factors of atopic dermatitis and to utilize the outcome in treatment planning. Methods : The research has a cross-sectional study design. Patients' SCORing Atopic Dermatitis (SCORAD) Index, demographic, physical characteristics, social history, serologic index and skin related instrumental measurements were analyzed with correlation and regression analysis method. Results : 48 patients in total were enrolled in the study. Skin Surface Hydration (SSH) and sex were found to be statistically significant aggravating and mitigating factors. As SSH increased, Total SCORAD (tSCORAD) and Objective SCORAD (oSCORAD) increased as well. As SSH decreased, tSCORAD and oSCORAD decreased as well. Female patient had a higher probability of suffering from severer subjective symptoms than that of male. Age, body mass index (BMI), alcohol consumption and smoking, transepidermal water loss (TEWL), IgE, IL-4, IL-5, IL-6, IFN-γ were found not to be statistically significant. There was no correlation between Subjective SCORAD (sSCORAD) and oSCORAD neither with Eczema Area and Severity Index (EASI). Conclusions : Increasing cutaneous moisture should be included in the treatment plan of atopic dermatitis. More emphasis should be put on alleviating subjective discomforts of female patients than that of male. Establishing separate strategies of managing objective eczema status and subjective discomforts respectively should be considered.

• 한국포장학회지
• /
• 제27권2호
• /
• pp.115-121
• /
• 2021

The evaluation of package temperature for fresh preservation of cucumber was investigated. The fresh cucumber is available in markets of Korea during whole seasons, for the help of farmer, distributor and consumer. Cucumbers were stored within cardboard boxes packaging covered with low density polyethylene (LDPE) at different temperatures (5, 10, 15 and 20℃). Changes in weight loss, hue angle, firmness, moisture content and general appearance (shape of cucumber) were investigated during storage of cucumbers. General appearance index with non-packaging decreased more than with LDPE film packaging at 5℃ and 10℃. During storage of cucumbers, general appearance index as freshness showed packaging effect at low temperature than room temperature. In the fresh weight loss, the packaged cucumbers were less reduced than that of the non-packaging ones. At color change, Hue angle of cucumber stored within low temperature with film packaging decreased gradually during storage. However remarkable change in hue angle were observed in cucumber within LDPE film packaging treatments of 15℃ and 20℃ storage. The effect of hue angle with packaging appears differently depending on the storage temperature conditions. The firmness and moisture content of cucumber flesh were not affected by packaging and storage temperature. In this experiment, cucumbers packaged with LDPE film at 5℃ and 10℃ were the most desirable for extending the quality. These results suggest that packaging of low temperature treatments in combination could be effective in prolonging the shelf life of cucumber.

• 대한본초학회지
• /
• 제32권2호
• /
• pp.49-56
• /
• 2017

Objectives : This study investigated the anti-oxidant activities and improving effect of Phellinus linteus and Glycyrrhiza uralensis Extract (PGE) on Atopic Dermatitis. Methods : 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical, Hydrogen peroxides scavenging activities and Superoxide dismutase (SOD)-like activities were used for the measurement of anti-oxidant ability. Cytotoxicity of PGE in Raw 264.7 cell was evaluated by MTT assay. To evaluate the anti-atopic dermatitis effect of PGE, a total of 33 patients with atopic dermatitis were observed trans epidermal water loss, skin moisture content, modified SCORAD index of atopic dermatitis and pruritic degree after applying the PGE for 4 weeks. Results : PGE scavenged DPPH ($IC_{50}=25ppm$) effectively, ABTS and Hydrogenperoxides scavenged similar to BHA. As for the SOD-like activity, it had lower effect than ascorbic acid, but it comparable activities in 500ppm. There was no cytotoxicity at PGE at concentrations of 10,000ppm. In clinical research about PGE on patients with atopic dermatitis, skin condition was improved. After 4 weeks, the application of PGE increased skin moisture content from 19.43 to 31.22. Moreover, it reduced the skin temperature (from 32.5 to 31.9), skin pH (from 5.39 to 5.22), trans epidermal water loss (from 39.03 to 24.46) and pruritus score (from 6.07 to 3.87). In addition, the Modified SCORAD index decreased from 31.28 to 20.3. Conclusions : In conclusion, PGE possesses anti-oxidant and anti-atopic dermatitis activities, thus it could be potentially valuable as anti-atopic dermatitis material.