• Title/Summary/Keyword: degree days

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AN EXPERIMENTAL STUDY OF THE DEGREE OF CONVERSION AND CYTOTOXICITY OF DUAL CURE RESIN CEMENTS (수종 이원중합 레진 씨멘트의 중합률 및 세포 독성에 관한 실험적 연구)

  • Roh, Byoung-Duck;Park, Seong-Ho;Lee, Chung-Suck
    • Restorative Dentistry and Endodontics
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    • v.20 no.1
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    • pp.33-54
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    • 1995
  • The degree of conversion of composite resin was known to have influence on the mechanical properties of composite materials such as hardness, strength, wear resisitance, dimensional and color stability. Also unreacted monomer was reported to be harmful to the pulp. So the degree of conversion was a very important factor in the success of composite resin restorations. In recent, the dual cure resin cement was developed with the advocations that it could increase the curing rates in the sites where the curing ligt could not reach. Moreover many manufactors added some adhesive components in the resin cement. This study was undertaken to observe the effects of curing depth and light curing times on the degree of conversion of dual cure resin cements. CR INLAY CEMENT, DUAL CEMENT and OPTEC BOND, by the Fourier transform Infrared analysis, changing the curing depth 1mm, 2mm and 3mm, and varying the light curing time 20 seconds, 40 seconds and 80 seconds at each depth. The cytotoxicity of dual cure resin cements was tested by the in vitro MTT method using L929 cell. The results was evaluated and compared statistically. The results were obtained as follows : 1. The dual cure resin cements reavealed various degree of conversion, CR INLAY CEMENT and DUAL CEMENT had a tendency to be more reactive to the light cure and OPTEC BOND was a more chemical one. 2. CR INLAY CEMENT and DUAL CEMENT showed the lowest degree of conversion in 2 mm depth, and in 3mm depth the degree of conversion increased, which were due to the chemical cure of dual cures, but OPTEC BOND showed decreasing degree of conversion with increasing curing dept h and all experimental groups showed lower degree of conversion than CHEMICAL group which cured in dark room with no light, so the weak light-curing of dual cure resin cement prevented the chemical cure. (P<0.05) 3. CR INLAY CEMENT and DUAL CEMENT showed increasing degree of conversion in 1 mm and 3 mm, according to the increasing cure times, but in 2 mm depth the degree of conversion decreased with increasing light-curing times and OPTEC BOND showed contrary tendency, but there was no ststistical importance in the differences among the experimental group.(P>0.05) 4. The optical density by MTT assay of extractions of CR INLAY CEMENT, DUAL CEMENT and OPTEC BOND revealed no statitically important differences comparing with optical density of negative control.(P>0.05) 5. CR INLAY CEMENT showed a tendency of increaing cytotoxicity with days and DUAL CEMENT and OPTEC BOND showed higher cytotoxicity in 2 days than in 4 days, but there was no statistical importance in the differences.(P>0.05).

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Relationship Between Heat Unit Requirement and Growth and Yield of Mulberry, Morns indica L.

  • Sarkar A.;Rekha M.;Keshavacharyulu K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.10 no.1
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    • pp.65-68
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    • 2005
  • Growth and development of a plant over a growing season is closely related to the daily accumulation of heat. Heat unit measured by accumulated growing degree days (GDD) is becoming increasingly popular to estimate the growth of a plant or even in insect. GDD or heat accumulation per day is measured by calculating average daily temperature and then subtracting the base temperature below which growth does not occur. Heat accumulation per day is added for the desired period and accumulated GDD is determined. The present study was conducted in five seasons in an established garden with K-2, S-36 and V-1 mulberry varieties belonging to Morus indica L. grown under completely irrigated condition at the farm of CSRTI, Mysore during 2001 - 2002. Plants were pruned in each season and the growth of the plant measured by total shoot length and fresh leaf yield was recorded at an interval of 5 days starting from 30 days of pruning (DAP) to 70 days when all the plants were pruned. The accumulated GDD for the corresponding days were recorded and used for analysis. Accumulated growing degree days (GDD) have been found to be perfectly correlated with both growth and yield in all the seasons in all the varieties studied. The high $R^2$ values indicated a strong relationship between the accumulated GDD and, growth and yield of mulberry.

Biological and Physiochemical structure change of Black pine bast scale (Matsucoccus thunbergianae) in coast area of Korea (해송림에 만연된 솔껍질깍지벌레 피해목의 물리 화학적 및 생물학적 구조변화에 관한 연구(III))

  • 김규진;김종완;임기표
    • Korean journal of applied entomology
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    • v.34 no.3
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    • pp.174-180
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    • 1995
  • The damage rate according to the age of black pine trees in the Black pine bast scale, Matsucoccus thunbergianae was high from 7 to 22 year old trees. According to damaged degree of damaged trees, it showed great difference in infection rate of saprophitic fungi. The period until the developmental degree of saprophitic fungi became maximized degree of 7 was required about 48 days in dead tree of 100 percent, about 54 days in one of above than 80 percent, about 75 days in one of 40~50 percent, but the dead tree less than 10 percent and health tree was retained the 3~4 developmental degree of saprophitic fungi, after 80 days. The ring width of damaged trees showed as follows. The non damaged trees was 3.52 cm, 0.77 cm in the damaged trees of 100 percent, 0.88 cm in the ones of 80 percent, 1.22 cm in the ones of 40~50 percent and 1.37 cm in the ones of les than 10 percent, respectively. Number of cells per unit area was smaller in the case of greater damaged trees, gradually. Also moisture content was very high in greater damaged trees, and bending strength was lower. Extracts by the one percent NaOH showed a small amount.

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Clinical study on the improvement degree of Bell's palsy with DITI (DITI를 이용한 안면신경마비환자의 호전도에 대한 임상적 고찰)

  • Sung, Byung-Gon;Park, Min-Chul;Lim, Kyu-Sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.13 no.2
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    • pp.190-199
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    • 2000
  • We had studied the relationship between the difference of average temperature of Meridian points of left and right face taken by DITI on 1st hospital day and the improvement degree of facial mucles on the patients of Bell's palsy after 10 days treatment. The clinical data and thermographic imaging were analyzed on the 42 cases of Bell's palsy who were treated in the Chunju Oriental Medicine Hospital of Wonkwang University from May to November 1999, and we selected 29 cases within 10 day-onset and the following results were obtained. 1. Assuming the difference of the muscle scores' sums very attending day from after 10 days treatment is improvement degree, and presuming the improvement degree is y, and the mean difference of average temperature between normal and abnormal facial side is x, we can infer the equation of the first degree as following [ y = 2.62 + 2.16 x ]. 2. This means that the higher temperature of nerve falsy side than normal side, the better consequence of treatment we can obtain.

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A Study on Fitness of Middle School Girls Uniform Size in Consideration of Growth -Focusing on Jacket and Skirt- (여중생 성장을 고려한 최적 교복치수 선정 -자켓과 스커트를 중심으로-)

  • 김덕하;김인숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.2
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    • pp.315-326
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    • 2001
  • This study is to suggest data for setting school uniform size with the size satisfaction degree through finding out the physical body change and uniform size problems following an increase in age during middle school girl days. For this purpose, by analyzing the physical body size data of 13~15 age of girls among $\ulcorner$human body size data of the youth for product design$\lrcorner$publicized under sponsorship of National Technology Quality Institute in 1999 the physical body size change by part following an increase in age during middle school girl days was found out and the most frequent physical body size by grade was suggested. Questionnaire about uniform production status and product size at the object of uniform makers were measured directly, a school uniform wearing status and size satisfaction degree by part were at the abject of middle school girls were examined by means of questionnaire and unsatisfactory factors in uniform size were found out. Based on collected data the most optimum product size in each part by item were suggested. The method of suggesting the most optimum size suitability by item was decided based on the result of survey into corresponding title and product size by maker and that of survey into the size satisfaction degree of middle school girls by maker, and the product size of maker showing the highest size satisfaction degree was selected as the most optimum product size.

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Oviposition Time of Overwintered Females and Migration of Crawlers of Pseudaulacaspis prunicola (Homoptera: Diaspididae) on Cherry Trees in Jeju Island (제주도 벚나무에 발생하는 벚나무깍지벌레 월동성충의 산란시기 및 부화약충 이동시기)

  • Kim, Dong-Soon
    • Korean journal of applied entomology
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    • v.44 no.3 s.140
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    • pp.231-235
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    • 2005
  • This study was conducted to obtain the optimal spray time for Pseudaulacaspis prunicota (Maskell) (Homoptera: Diaspididae) in early seaon in Jeju. Oviposition time of overwintered females and activity of hatched nymphs of P. prunicola were monitored, and the phenology data were compared with the outputs estimated by a degree-days model of P. pentagona (Targioni-Tozzetti)). Overwintered females of P. prunicola began to lay eggs from mid to late April, and the eggs started to hatch from early May followed by the active migration of the hatched nymphs during mid May. The phenological events of P. prunicola in early season were likely comparable with those of P. pentagona reported in southern Korea and in central Japan. A degree-day model, which predicts the proportion of >50% hatched egg batches of P. pentagona (y=1[exp(-(-a+bx))]; y, proportion; x, degree-days based on $10.5^{\circ}C$ from 1 January; a=-18.80 and b=0.073), accurately described the migration time of P. prunicola hatched nymphs. Thus, it is considered that the degree-day model can be used for predicting the optimal spray time for P. prunicola in early season.

Changes of Chemical Composition in Tuberous Root of Yacon by Different Curing Conditions

  • Doo, Hong-Soo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.2
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    • pp.79-82
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    • 2000
  • Tuberous root of yacon (Polymnia sonchifolia Poeppig & Endlicher) has not starch, and its brix degree changes during the curing. Therefore its chemical composition changes were investigated according to different curing conditions. Tuberous root contained 87.1% moisture at harvesting, that was decreased to 84.1-86.0% at 30 days after curing in different curing conditions. Brix degree was increased from 5.7 to 14.2-15.8% at 30 days after curing in comparison to at harvesting. Free sugars were detected from tuberous root in yacon by HPLC; that were fructose, glucose and sucrose. Fructose contents were increased from 0.09 to 1.04-1.79% during 30 days in five curing conditions. Glucose contents were shown to increase from 0.03 to 1.04-1.37 %. Sucrose contents were shown to increase from 0.04 to 0.13-0.43%. Tuberous root contained fructose, glucose and sucrose in order of amount that were highest in single-polyethylene film covered green house. Sucrose was little as comparison with fructose and glucose. Fructose and glucose were increased to 16.7 and 40.7 times, respectively, but sucrose was increased little about 6.8 times.

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The Effect of Ulmus Dressing on Burn Wound in Rats (느릅나무 근피 드레싱이 쥐에 유발된 화상의 회복에 미치는 효과)

  • Na, Yeon-Kyung;Hong, Hae-Sook
    • Journal of Korean Biological Nursing Science
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    • v.7 no.1
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    • pp.89-98
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    • 2005
  • Purpose : The purpose of this study is to compare the effect of Ulmus(root-bark) dressing with vaseline gauze dressing on burn wound(third degree) in rats. Method : Ten male Sprague-Dawley rats were used in the study. The rats were anesthetized with Ketamine l00mg/kg. burn wounds were made for each animal by specially designed apparatus. Ulmus dressing was applied once a day for 4 weeks in the experimental group(n=5), vaseline gauze dressing in the control group(n=5). The wounds were photographed and excised. Result : After 10 days of dressing, size of burn wounds of Ulmus dressing group decreased significantly compared to that of vaseline gauze dressing group. After 10 days of dressing, degree of inflammatory infiltration was shown lower in Ulmus dressing than in vaseline gauze group. There was no significant difference after dressing at day of 19 and 27 in degree of inflammatory infiltration.

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Development of Meloidogyne arenaria on Oriental Melon (Cucumis melo L.) in Relation to Degree-day Accumulation Under Greenhouse Conditions

  • Kim, Dong-Geun;Yeon, Il-Kwon
    • The Plant Pathology Journal
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    • v.17 no.3
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    • pp.159-163
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    • 2001
  • Influence of soil temperature [accumulated degree-day for the base temperature $5^{\circ}$($\textrm{DD}_5$)] on the development of Meloidogyne arenaria were studied in a winter grown oriental melon greenhouse in Seongju, Korea. Egg masses were first observed on roots at the accumulation of 565 $\textrm{DD}_5$(40 days after transplanting), suggesting that the nematode has completed the first generation in 40 days. Second-stage juveniles (J2) densities were lowest at 863 $\textrm{DD}_5$ in April, first increased at 1,334 $\textrm{DD}_5$ in May, peaked at 2,951 $\textrm{DD}_5$ in July, and decliner thereafter. Development of egg masses and J2 density in soil revealed that M. arenaria could develop in 7-8 generations in a year in the greenhouse. Degree-day monitoring, therefore, could aid to predict nematode development in soil and can be valuable tool a to develop root-knot nematode control strategies.

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AUTORADIOGRAPHIC STUDY ON SEALING ABILITY OF VARIOUS ROOT CANAL SEALERS (수종(數種) 근관충전재(根管充填材)의 근관폐쇄(根管閉鎖) 효과(效果)에 관(關)한 자기(自記) 방사법적(放射法的) 연구(硏究))

  • Choi, Woong-Dai;Park, Sang-Jin;Min, Byung-Soon;Choi, Ho-Young
    • Restorative Dentistry and Endodontics
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    • v.14 no.1
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    • pp.161-171
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    • 1989
  • The purpose of this study was to evaluate and compare the sealing ability of ZOE, FR and Sealapex, as a root canal sealer. Ninety six extracted anterior or premolar human teeth with single root were instrumented by using conventional method. After instrumentation, the teeth were divided into three groups and thirty two teeth in each group were filled as follows: ZOE group: ZOE cement as a root canal sealer in combination with guttapercha cone FR group: FR root canal sealer in combination with guttapercha cone Sealapex group: Sealapex root canal sealer in combination with guttapercha cone $^{45}Ca$ in the form of calcium chloride, was employed as the tracer in this study and produce the auto-radiograph. The depth of isotope penetration into the root canal was evaluated by method by Yates and Hembree at the intervals of 1 day, 7 days, 14 days and 30 days. The following conclusions were derived from the results obtained; 1. After 1 day, ZOE group exhibited the greatest penetration degree of radioisotope (p < 0.05). 2. After 14 days, there was some difference of the radioisotope penetration between each group, but its difference was not significant statistically. 3. After 30 days Sealapex group exhibited the least penetration degree of radioisotope (p < 0.025). 4. In ZOE and Sealapex groups, there was no change of the degree of radioisotope penetration with time.

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