• Title/Summary/Keyword: degree-days

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An Experimental Study on the Durability of Concrete adding MgO-Type Expansive Agent (MgO를 혼합한 콘크리트의 내구특성 평가에 관한 실험적 연구)

  • Kim, Tae-Sang;Jang, Bong-Seok;Jung, Sang-Hwa;Kim, Joo-Hyung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.397-400
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    • 2008
  • MgO powder-mixed concrete, expanded at the lower temperature around $850{\sim}1000$ degree celcius, might have long-term expansibility, which could remunerate for the contraction of concrete with delayed expansion, and through the process, the crack resistance of mass concrete might be improved. Currently used expandable concrete additive has three different types : CSA, CaO and MgO. In this study, therefore, such tests as carbonation, chloride diffusivity, freezing-thawing resistance and sulfate resistance after 56 days' curing were implemented and compared the results with the concrete with no MgO mixed to evaluate the durability of 5% MgO-mixed concrete after longer period of time. The degree of hydration for the MgO-mixed cement paste was analyzed after 1 day, 3 days, 7 days, 28 days, and 56 days using SEM, XRD, DSC.

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Correlation between the Time to Surgery and That to Recovery from Postoperative Diplopia Based on a Single-Center, Retrospective Experience: A Case Series of 11 Patients

  • Kim, Nam Hoon;Kang, Seok Joo
    • Archives of Plastic Surgery
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    • v.41 no.5
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    • pp.486-492
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    • 2014
  • Background We conducted this study to identify the correlation between the time to surgery and that to recovery from postoperative diplopia. Methods In the current single-center, retrospective study, we enrolled a total of 11 patients (n=11) who were diagnosed with white-eyed blowout fracture and underwent surgical operation at our institution between January 2009 and January 2013. To identify the correlation between the time to surgery and that to recovery from postoperative diplopia, we divided our patients into the three groups: the group A (time to surgery, <2 days) (n=4), the group B (time to surgery, 3-7 days) (n=4) and the group C (n=3) (time to surgery, 8-60 days). Then, we compared such variables as sex, age, signs of soft tissue injury, preoperative nausea/vomiting, the degree of preoperative diplopia and the side of the fracture on computed tomography scans between the three groups. Results In our series, mean age at the onset of trauma was nine years (range, 5-16 years); the mean time to surgery was 30 days (range, 2-60 days); and the mean follow-up period was one year (range, 6 months-2 years). Our results showed that the time to recovery was shorter in the patients with a shorter time to surgery. Conclusions We found that the degree of recovery from impaired ocular motility and diplopia was the highest in the patients undergoing surgical operations within 48 hours of the onset of trauma with the reconstruction of the fracture sites using implant materials.

An Experimental Study on the Heterotopic Canine Heart Transplantation: Pathologic Observation (동종 심장이식의 병리조직학적 연구)

  • 손광현;서경필;이영균
    • Journal of Chest Surgery
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    • v.2 no.2
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    • pp.155-166
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    • 1969
  • Heterotopic abdominal homograft of canine heart was carried out in 20 pairs of dogs. Of these 12 cases were subjected as a control and 8 were subjected to immunosuppressive group. The dosage of immunosuppressive agent was 5mg/kg/day of Imuran [Azathioprine] for 3 days preoperatively, 10mg/kg on operative day and 5mg/kg/day postoperatively. For reducing the metabolic demand, the donor heart was preserved in 4degree heparinized saline solution for approximately I4 minutes. In the most of the cases, transplantation was performed with the technique of end-to-side aorto-aortic anastomosis and end-to-side pulmonary artery-inferior vena cava anastomosis at the infrarenal portion. Five out of 20 grafted dogs were survived more than one day. The longest survived 18 days in the control group and survive more than 60 days in the treated group. The survival cases were 3 out of 8[37. 5%] in the group of dogs treated with lmuran and 2`out of 12 [16.6%] in the group of non-treated. A prominent gross findings of the grafted heart was a minimal to moderate degree of dilatation of the heart with or without thrombosis in the cardiac chambers and/or anastomotic site. The case number 10, 15, and 19 showed moderate hypertrophy in grossly. The microscopic findings were as follows; 1. There were early hypersensitive histologic reactions such as interstitial edema, cellular infiltrations and early degenerative changes in the myocardium in the cases of 3 hour survival. 2. In the cases of more than 6 hours survival, organizing thrombosis of myocardial vessels, vasculitis,myocardial necrosis and lymphocyte, plasma cell, round cell infiltrations were noted. In the cases of more than 12 hours survival, the degree of these histologic changes especially in the non-treated group were more intensified than in the treated. 3. In the cases which survived more than one day, so called homograft specific histologic changes were milder in the immunosuppressive group compared with the control. 4. All the host hearts showed no evidence of pathologic findings histologically. Among the homologous canine cardiac transplantation tissue reaction, was milder and suvival time longer in the group treated with immunosuppressive drug.

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Physicochemical and Sensory Characteristics of Gangjung Containing Sorbitol during Storage (솔비톨을 첨가한 강정의 저장 중 이화학적 및 관능적 특성 변화)

  • Baik, Eun-Young;Lee, Hye-Seong;Lee, Kyung-Sook;Lee, Jin-Won;Kim, Haeng-Ran;Cho, Mi-Sook;Kim, Kwang-Ok
    • Journal of the Korean Society of Food Culture
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    • v.22 no.1
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    • pp.115-126
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    • 2007
  • This study was conducted to preserve the quality of Gangjung (Traditional Korean cookies) during storage with the addition of sorbitol in Gangjung dough. Sorbitol was added with different levels (0, 1.5, 3%) in the Gangjung dough and the Gangjung samples were stored for different periods (1, 16, and 31 days). Compared to the control group, the Gangjung samples with sorbitol groups had higher moisture content, expansion ratio, and ceil size. As the storage was extended, peroxide values, hardness, fracturability, chewiness and stickiness to teeth were increased, while cohesiveness, moistness, and degree of melting were decreased. From the PCA in the sensory analysis, Gangjung with addition of 3% sorbitol stored for 1, 16, and 31 days showed high levels in moistness, cohesiveness, degree of expansion, cell size, and degree of melting, whiie Gangjung in control group stored for 16 and 31 days showed high levels in fracturability, heated oil flavor, chewiness, and stickiness to teeth. The moisture content of Gangjung was significantly increased as the level of sorbitol was increased. The changes of physicochemical and sensory characteristics by storage were increased in control groups the most, 1.5% sorbitol groups the next, and 3% sorbitol groups the least. Therefore, the sorbitol added groups could be delayed in the quality deterioration during storage, especially in the texture, and could be increased in the preservation of Gangjung.

Models of Forecasting the Generation Peak Time of Scirtothrips dorsalis (Thysanoptera: Thripidae) adults Based on Degree-days on Jeju Island, Korea (제주에서 적산온도를 이용한 볼록총채벌레 세대별 발생최성기 예측모형)

  • Hwang, Rok Yeon;Hyun, Jae wook;Kim, Dong-Soon
    • Korean journal of applied entomology
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    • v.52 no.4
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    • pp.415-425
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    • 2013
  • The yellow tea thrips, Scirtothrips dorsalis (Thysanoptera: Thripidae), has been regarded as a minor pest on citrus on Jeju Island. However, the damage of yellow tea thrips has gradually increased since 2007. This study was conducted to develop a forecasting model for generation peak time of S. dorsalis by using degree-days. Simple linear regression analysis was applied to determine the relationship between the generation number (x, dependent variable) and degree-days (y, independent variable). As a result, two regression models were established: citrus-based model (y = 310.9x + 69.0, $r^2$=0.99) and green tea-based model (y = 285.7x + 84.1, $r^2$=0.99). The models was fitted by independent data sets obtained from 2013 and evaluated using the technique of RSS (residual sum of square) and ${\chi}^2$-test. The green tea based-model showed a good fitting ability. The discrepancy between model outputs and actual data, and the practical application of models were discussed.

Correlation between Air Temperature Factors and Leafing Date of Mulberry Tree (뽕나무 출엽일과 기온 요인 간 상관성)

  • Kim, Ho Cheol;Kim, Tae-Choon
    • Horticultural Science & Technology
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    • v.33 no.6
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    • pp.807-811
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    • 2015
  • This study was conducted to identify the air temperature factors that affect leafing date of mulberry (Morus alba) in Buan, Jeonbuk province. Over the period from 2009 to 2014, the leafing date averaged April 24 (114 Julian days). The earliest leafing date was April 12, in 2014, and the latest leafing date was May 2, in 2011. Yearly variations of daily mean temperature (DMT) and daily maximum temperature (DMxT) were high in the last part of March. There were highly negative correlations between leafing date and degree days of accumulated DMT above 0, 5, and $10^{\circ}C$ in the period from March 1 to April 10. Linear regression equations for estimating the leafing date were y = 153.8 - 0.1886 ${\times}$ ($r^2=0.965^{**}$) and y = 126.2 - 0.2246 ${\times}$ ($r^2=0.825^*$) for the degree days of accumulated DMT above $5^{\circ}C$ in the period from March 1 to April 10 and the last part of March, respectively. Therefore, leafing date of mulberry, which is important for popcorn disease control, is 96.5% predicted by degree days of accumulated DMT above $5^{\circ}C$ in the periods from March 1 to April 10.

Effects of Temperatures on Development and Distribution of Mulberry scale, Pseudaulacaspis pentagona, within Tree (온도조건이 뽕나무깍지벌레의 발육 및 수내분포에 미치는 영향)

  • 박종대;김규진
    • Korean journal of applied entomology
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    • v.29 no.4
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    • pp.238-243
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    • 1990
  • These studies were conduced to investigate the effects of temperatures on development of each stage and distribution within tree and overwintering of mulberry scale, Pseudaulacaspis pentagona Tar. & Tozz. Growth ratio of each stage with different temperatures was not significant within range of optimum temperatures of growth. Developmental threshold and effective temperatures of each stage were $12.3^{\circ}C$ and 46.9 degree day in eggs, $10.8^{\circ}C$, and 183.8 degree day in first nymph, $9.8^{\circ}C$ and 188.2 degree day in second nymph, $10.3^{\circ}C$ and 383.0 degree day in gross nymphal stage, respectively. Longevity of female adults were 39.6 days in $18^{\circ}C$, 28.4 days in $22^{\circ}C$, 18.1 days in$26^{\circ}C$, and 15.7 days in$30^{\circ}C$. Average number of eggs in ovary and laid by individual female were 83.3 and 75.7, respectively. Optimum temperatures of growth were $22^{\circ}C$-$26^{\circ}C$ but all the eggs were not hatched at $35^{\circ}C$. Distribution of each stage within tree in summer was great at lower part of branch and overwintering adults was dominantly located in NE-SE followed by SE-SW, SW-NW and NW-NE. Percent mortality due to cold weather was 36.2.

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Proposed Treatment Protocol for Frostbite: A Retrospective Analysis of 17 Cases Based on a 3-Year Single-Institution Experience

  • Woo, Eun-Kyung;Lee, Jong Wook;Hur, Gi-Yeun;Koh, Jang-Hyu;Seo, Dong-Kook;Choi, Jai-Ku;Jang, Young-Chul
    • Archives of Plastic Surgery
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    • v.40 no.5
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    • pp.510-516
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    • 2013
  • Background This paper discusses the treatment protocol for patients with frostbite. Methods We performed a retrospective analysis of a series of 17 patients with second- and higher-degree frostbite who had been treated at our medical institution between 2010 and 2012. Results Our clinical series of patients (n=17) included 13 men and four women, whose mean age was $42.4{\pm}11.6$ years (range, 22-67 years). The sites of injury include the foot in six patients (35.3%), the hand in six patients (35.3%) and the facial region in five patients (29.4%). Seven patients with second-degree frostbite were completely cured with only conservative treatment during a mean period of $12.7{\pm}3.3$ days (range, 8-16 days). Of the five patients with third-degree frostbite, two underwent skin grafting following debridement, and the remaining three achieved a complete cure with conservative treatment during a mean period of $35{\pm}4.3$ days (range, 29-39 days). Five patients with fourth-degree frostbite were treated with surgical procedures including amputation. Conclusions With the appropriate conservative management in the early stage of onset, surgeons should decide on surgery after waiting for a sufficient period of time until the demarcation of the wound. Continuous management of patients is also needed to achieve functional recovery after a complete cure has been achieved. This should also be accompanied by patient education for the avoidance of re-exposure to cold environments.

Projection of Future Heating and Cooling Degree Days over South Korea under the IPCC SRES Scenarios: An Experiment with CCSM3 and MM5 Models (IPCC SRES 시나리오에 따른 우리나라의 미래 냉난방도일 전망: CCSM3와 MM5 모델 활용)

  • Choi, Jin Young;Song, Chang Kun;Kim, Deok Rae;Hong, Sung Chul;Hong, Yoo Deog;Lee, Jae Bum
    • Journal of Climate Change Research
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    • v.4 no.2
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    • pp.141-158
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    • 2013
  • In this study, the projection of future heating and cooling degree days (HDDs and CDDs) has been conducted over South Korea for the period 1996~2005 with 2046~2055 and 2091~2100, using CCSM3 and MM5 simulations driven by the six IPCC SRES emission scenarios (A2, A1B, A1FI, A1T, B1, and B2). Annual mean surface air temperature increases by $1.2{\sim}3.4^{\circ}C$ at the end of the 21st century comparing to the present-day (1996~2005) in South Korea. HDDs decrease by 8~25% and CDDs increase up to 242~1,448% with corresponding changes in temperature. These increases and decreases also change the duration of HDDs and CDDs. HDDs duration decreases by 1 month, while the expansion of CDDs duration is much longer than 2 months. Thus, projected future HDDs and CDDs changes appear that cooling energy demand in summer season would increase and heating energy demand in winter would decrease in the future. Especially, these remarkable changes would be obvious at high mountain area, Gangwon-do and at south area, Jeju island. In the sense of future energy supply and policy, electrical energy for cooling in summer could be getting much more its importance rather than fossil energy used for heating in winter.

Non destructive test of Fire-damaged reinforced concreted beams with high strength concrete (화재 피해를 입은 고 강도 철근콘크리트 휨 부재의 비파괴 검사)

  • 신미경;신영수;이차돈;홍성걸;김희선
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.651-654
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    • 2003
  • Non-destructive testing is essential in the inspection of alteration, repair and new construction in construction industry. This paper is to evaluate the strength variation of fire damaged concrete by non-destructive testing. Furthermore, It is to infer the recovery degree of residual strength of fire-damaged concrete. For this purpose, researchers are exploring the performance of non-destructive testing method using ultrasonic testing and Schmidt hammer in concrete specimens. Testing is performed four-times: before fire test, directly after fire test, after 20 days and after 60 days.

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