• Title/Summary/Keyword: N/S ratio

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Development of Analytical Method for the Determination and Identification of Unregistered Pesticides in Domestic for Orange and Brown Rice(I) -Chlorthal-dimethyl, Clomeprop, Diflufenican, Hexachlorobenzene, Picolinafen, Propyzamide- (식품공전 분석법 미설정 농약의 잔류분석법 확립(I) -Chlorthal-dimethyl, Clomeprop, Diflufenican, Hexachlorobenzene, Picolinafen, Propyzamide-)

  • Chang, Hee-Ra;Kang, Hae-Rim;Kim, Jong-Hwan;Do, Jung-A;Oh, Jae-Ho;Kwon, Ki-Sung;Im, Moo-Hyeog;Kim, Kyun
    • Korean Journal of Environmental Agriculture
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    • v.31 no.2
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    • pp.157-163
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    • 2012
  • BACKGROUND: For the safety of imported agricultural products, the study was conducted to develop the analytical method of unregistered pesticides in domestic. The analytical method of 6 pesticides, chlorthal-dimethyl, clomeprop, diflufenican, hexachlorobenzene, picolinafen, and propyzamide, for a fast multi-residue analysis were established for two different type crops, orange and brown rice by GC-ECD and confirmed by mass spectrometry. METHODS AND RESULTS: The analytical method was evaluated to limit of quantification, linearity and recoveries. The crop samples were extracted with acetonitrile and performed cleanup by liquid-liquid partition and Florisil SPE to remove co-extracted matrix. The extracted samples were analyzed by GC-ECD with good sensitivity and selectivity of the method. The limits of quantification (LOQ) range of the method with S/N ratio of 10 was 0.02~0.05 mg/kg for orange and brown rice. The linearity for targeted pesticides were $R^2$ >0.999 at the levels ranged from 0.05 to 10.0 mg/kg. The average recoveries ranged from 74.4% to 110.3% with the percentage of coefficient variation in the range 0.2~8.8% at two different spiking levels (0.02 mg/kg and 0.2 mg/kg, 0.05 mg/kg and 0.5 mg/kg) in brown rice. And the average recoveries ranged from 77.8% to 118.4% with the percentage of coefficient variation in the range 0.2~6.6% at two different spiking levels (0.02 mg/kg and 0.2 mg/kg, 0.05 mg/kg and 0.5 mg/kg) in orange. Final determination was by gas chromatography/mass spectrometry/selected ion monitoring (GC/MS/SIM) to identify the targeted pesticides. CONCLUSION: As a result, this developed analytical method can be used as an official method for imported agricultural products.

Effects of Solvent Extraction by Immersion on the Quality and Storage Stability of Rice (용매침지(溶媒浸漬)에 의한 탈지(脫脂)처리가 쌀의 품질(品質) 및 저장성(貯臧性)에 미치는 영향)

  • Cheigh, Hong-Sik;Kwon, Tai-Wan
    • Korean Journal of Food Science and Technology
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    • v.4 no.4
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    • pp.271-275
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    • 1972
  • Effects of solvent extraction by immersion on the quality and storage stability of Korean rice were studied. Proportions of lipid extracted from whole grain of rice by immersing into two volumes(v/wt) of hexane and ethanol for 72 hours at room temperature were 0.41% and 0.38% respectively. Small changes of water content and hardness of rice were observed by solvent treatment. Cooking characteristics; that is, water-uptake ratio. extended volume, total solid, and starch-iodine blue test of rice was markedly changed by ethanol treatment, while little changes were observed by hexane treatment. No considerable differences in moisture sorption isotherm of rice were observed by both solvent treatments. Changes in TBA number and stale flavor appearance of rice treated with or without solvent immersion during storage at $60^{\circ}C$ showed that rice treated with hexane had best storage stability compared to ethanol treatment, while ethanol treatment of rice had better storage stability than no treatment. Similar results were noted in changes of the flavor score of cooked rice samples which were freeze dried.

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Clinical Significance of Lymph Node Micrometastasis in Patients with Stage 1 Non-Small Cell Lung Cancer (제1기 비소세포폐암 환자에서 임파절 미세전이와 예후와의 상관관계)

  • 최필조;노미숙;이재익
    • Journal of Chest Surgery
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    • v.36 no.5
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    • pp.348-355
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    • 2003
  • Background: The prognostic significance of lymph node micrometastasis in non-small cell lung cancer remains controversial. We therefore investigated the clinicopathologic factors related to lymph node micrometastsis and evaluated the clinical relevance of micrometastasis with regard to recurrence. Material and Method: Five hundred six lymph nodes were obtained from 41 patients with stage 1 non-small ceil lung cancer who underwent curative resection between 1994 and 1998. Immunohistochemical staining using anti-cytokeratin Ab was used to detect micrometastasis in these lymph nodes. Result: Micrometastatic tumor cells were identified in pN0 lymph nodes in 14 (34.1%) of 41 patients. The presence of lymph node micrometastasis was not related to any clinicopathoiogic factor (p) 0.05). The recurrence rate was higher in patients with micrometastasis (57.1%) than in those without (37.0%), but the difference was not significant (p=0.22). Patients with micrometastasis had a lower 5-year recurrence-free survival rate (48.2%) than those without micrometastasis (64.1%), with a borderline significance (p=0.11), The S-year recurrence-free survival rate (25.0%) in the patients with 2 or more micrometastatic lymph nodes was significantly lower than that in the patients with no or single micrometastasis (p=0.02). In multivariate analysis, multiple lymph node micromestasis us was a significant independent predictor of recurrence (p=0.028, Risk ratio=3.568). Conclusion: Immunehistochemical anti-cytokeratin staining was a rapid, sensitive, and easy way of detecting lymph node micrometastasis. The presence of lymph node micrometastasis was not significantly associated with the recurrence, but had a tendency toward a poor prognosis in stage 1 non-small cell lung cancer. Especially, the presence of multiple micrometastatic lymph nodes was a significant and independent predictor of recurrence.

A Study on the Place Identity on the Vicinity of Sangsosan and Government Office of Buan-hyun by Letters Carved on the Rocks (바위글씨로 본 부안 관아와 상소산 일대의 장소정체성)

  • Rho, Jae-Hyun;Kim, Jeong-Moon;Lee, Hyun-Woo;Lee, Jung-Han;Kim, Dae-Soo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.2
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    • pp.142-154
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    • 2012
  • This study aimed at learning the characteristics of place identity of the Buan county hall garden and Sangsosan(上蘇山) by looking over the pattern and content of letter-engraved rocks and nearby facilities and history. Especially, we focused on the meaning and contents of the letters in Sangsosan and a Government Office of Buan engraved on rocks in order to learn what the place means. The results of our study are as follows. Buan-hyun(扶安縣) in the Joseon dynasty period blossomed literary culture of enjoying poetry and melody, and this was faithful realization of the concept of "Rakto(樂土)" of 'Saengubuan(生居扶安).' The grand scale letters written by Si-SooPark(朴蓍壽: 1767~1876), head of the office in the early 19th century, in the cursive style on the basis stone of the garden of Buan county building, which was the site of the office of Buan-hyun in the Joseon dynasty period, such as 'Bongraedongcheon(蓬萊洞天)', 'Jurim(珠林)', and 'Okcheon(玉泉)' mean that "'Bongrae', the another name of Buan', is a place where Taoist hermits would live because the spring water of Seorim flows down to be Okcheon.", showing his pride of living Buan. The regions like Seorimjeong, Geumdae(琴臺), and Hyecheon(惠泉) where letters engraved on rocks are located intensively are closely related with those who communicated with Mae-ChangLee(李梅窓: 1573~1610), the slave of the government, and are local attractions and garden traces where the literary culture and scholar's spirit of Buan are well-harmonized. Most of the letters were written from the 19th century to the early 20th century, showing that 4 for landscapes, 8 for Kyungseck(景色: imaginary scenry), 5 for figures, 15 for poems and 2 for others. The ratio of poems is much higher than that of poems in other regions' letters on rocks, and the keyword of the letters is Haecheon. A piece of the place identity heavily influenced by the Taois thermit ideology is revealed by the expressions of 'Bongraedongcheon', 'Sosansaho(蘇山四皓)' or 'the spring water of Haecheon' that was considered as an elixir of Taoist hermits. Seorim the forest, which had been managed after Yeon-Myeong Cho(趙然明: 1797~?), head of the office, planted trees in the 11th year of the reign of King Heonjong(1845), Seorimjeong in the forest, and rocks with engraved letters on them are proof of literary culture and the garden traces showing the characteristics and aspect of Imcheon(林泉) Garden of the office heavily influenced by the Taoist hermit ideology. Along with Naebyeon-san national park and Kyeokpo region, the center of Buan tourism, we hope that cultural heritages including rocks with engraved letters over Seorim park would become a representative cultural heritage and attraction of Buan.

Evaluation of Adsorption Characteristics of the Media for Biofilter Design (바이오필터설계를 위한 바이오필터 담체의 흡착 특성)

  • Lee, Eun-Ju;Lim, Kwang-Hee
    • Korean Chemical Engineering Research
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    • v.46 no.5
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    • pp.994-1001
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    • 2008
  • Freundlich isothermal adsorption parameters, applicable to such biofilter-model as process-lumping model(Lim's model), for sterilized granular activated carbon(GAC), sterilized compost and sterilized equal volume mixture of GAC and compost were obtained and were compared each other, assuming that adsorbents are enclosed by water layer, in order to construct robust process-lumping biofilter model effective for wide-range of hydrophilic volatile organic compounds(VOC). In this investigation 0.04, 0.08, 0.12, 0.16, 0.2, 0.4, 0.8 and 1.0ml of ethanol were added to three kinds of adsorbent-media and were placed at $30^{\circ}{\cdots}$ under the wet condition of the media, which was the same as biofilter operating condition, until the adsorption reached the condition of equilibrium before each adsorbed amount of ethanol was obtained. Then adsorption capacity parameters(K) and adsorption exponents of Freundlich adsorption isotherm equation, which simulates the adsorbed amount of ethanol equilibrated with the ethanol concentration of the condensed water in the pore of the media, were constructed for sterilized granular activated carbon(GAC), sterilized compost and sterilized equal volume mixture of GAC and compost as (0.7566 and $5.070{\times}10^{-7}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.7566}$), (0.8827 and $1.000{\times}10^{-8}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.8827}$) and (0.5688 and $5.243{\times}10^{-6}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.5688}$), respectively. These Freundlich isothermal adsorption parameters were applicable to the adsorption characteristics of biofilter media enclosed with bio-layer. The order of magnitude of the ratio of ethanol-air/water partition coefficient and toluene-air/water partition coefficient was almost consistent to that of ethanol-adsorbed amounts in this experiment with compost and in the investigation of Delhomenie et al. on toluene-adsorption to wet compost.

Augustin und die Rhetorik (아우구스티누스와 수사학)

  • Hahn, Seok-whan
    • Journal of Korean Philosophical Society
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    • v.116
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    • pp.389-410
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    • 2010
  • Augustin wurde sozusagen von der Rhetorik zum Christentum bekehrt. Der einstmalige Rhetorikprofessor (bis 386) distanziert sich von seiner $fr{\ddot{u}}heren$ Kunst. Aber er $kn{\ddot{u}}pft$ als Bischof im vierten Buch seiner weniger bekannten Schrift "De doctrina Christiana" (DDC; abgef. 427) wieder an die antike Rhetorik, speziell an Cicero, an. So wird die augustinische $Sp{\ddot{a}}tschrift$ $f{\ddot{u}}r$ eine antike Rhetorik in christlicher Verwendung gehalten. Es stellt nun die Frage, was Augustin zur $R{\ddot{u}}ckkehr$ zu seiner $fr{\ddot{u}}heren$ Kunst bewegte. Neuere Forschungen sehen in Augustins Werk eine Grundlage der mittelalterlichen Predigttheorie oder einen $blo{\ss}en$ Versuch, die Rhetorik vom Makel des Sophistischen zu befreien. Gewiss ist seine Einstellung zur "leeren Beredsamkeit" der Sophistik eindeutig, aber dies war eine Haltung, die letztlich von allen seinen christlichen Zeitgenossen geteilt wurde und folglich eines geringen Beweises bedurfte. Die Aufmerksamkeit, die Augustins $sp{\ddot{a}}terem$ Einfluss und seiner Ablehnung der Zweiten Sophistik geschenkt wird, kann den Blick $tr{\ddot{u}}ben$ $f{\ddot{u}}r$ seine Rolle bei der $L{\ddot{o}}sung$ eines christlichen Dilemmas aus dem vierten Jahrhundert. Augustin sah die Gefahren einer entgegengesetzten rhetorischen $H{\ddot{a}}resie$. Die $S{\ddot{u}}nde$ des Sophisten besteht darin, dass er die Notwendigkeit des Inhalts verneint und glaubt, nur die forma alleine sei $w{\ddot{u}}nschenswert$. Der gegenteilige Fehler, dem Geschichtsschreiber der Rhetorik niemals einen Namen gegeben haben, beruht auf dem Glauben, dass derjenige, der im Besitz der Wahrheit ist, auch ipso facto in der Lage ist, die Wahrheit anderen zu ${\ddot{u}}bermitteln$. Es handelt sich um eine $ausschlie{\ss}liche$ $Abh{\ddot{a}}ngigkeit$ von der materia. Augustin erkannte eine Gefahr und benutzte DDC dazu, eine Verbindung von Inhalt und Form in der christlichen Predigt voranzutreiben. Nur wenn man daher das Buch als einen Teil der $gro{\ss}en$ Debatte des vierten Jahrhunderts ansieht, tritt seine historische Bedeutung klar hervor. Der Leser ist beeindruckt davon, dass der Autor darauf insistiert, es sei eine Torheit, dem Feind ein $n{\ddot{u}}tzliches$ Instrument zu ${\ddot{u}}berlassen$. Augustin $erkl{\ddot{a}}rt$, dass die Kunst der Beredsamkeit rege in Gebrauch genommen und nicht kurzerhand abgelehnt werden solle, weil sie mit dem Makel des Heidentums behaftet sei. Kurz gesagt, geplant ist das vierte Buch von DDC als eine ratio eloquentiae Christianae.

Verification of the upper limit of results through dilution tests for RIA test (RIA 검사별 희석실험을 통한 결과의 상한치 검증)

  • LEE, Geun Ui;CHOI, Jin Ju;LEE, Young Ji;YOO, Seon Hee;LEE, Sun Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.26 no.1
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    • pp.42-46
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    • 2022
  • Purpose In the meantime, there have been not many samples that require dilution, and it has been difficult for the examiner to set an appropriate dilution multiple for RIA test item and report the results. Accordingly, it was judged that it was necessary to set the maximum dilution multiple for each test and to verify the upper limit of the clinical reportable range. Therefore, in this study, the maximum dilution multiple for each RIA test was set and the upper limit of the clinical reportable range was verified accordingly Materials and Methods Among all RIA tests conducted at Asan Medical Center, the study treated on 30 types of tests which also conduct the dilution test. Data from March to July 2021 were collected and analyzed. The study was conducted on samples subjected to serial dilutions such as X2, X4 or X10, X102, X103, X104, X105. Results Among a total of 30 test types, 18 test types have more than 5 N values in the tolerance range of 80~120%. As a result of the verification of maximum dilution multiples, the test set to 104 is 𝛼-fetoprotein and thyroglobulin, and the test set to 103 is CA-125, CEA, and 𝛽-hCG, and the test set to 102 is Free PSA, PSA, CA15-3, SCC, Ferritin, PTH, Cortisol, and Calcitonin. Tests set to 10 include three categories: 𝛽2-Microglobulin, C-peptide, and Testosterone. Conclusion It is expected that it will contribute to improving the quality of nuclear medicine blood tests as the results of dilution experiments can be reported quickly and accurately through the verification of the clinical reportable range.

Characteristics and classification of paddy soils on the Gimje-Mangyeong plains (김제만경평야(金堤萬頃平野)의 답토양특성(沓土壤特性)과 그 분류(分類)에 관(關)한 연구(硏究))

  • Shin, Yong Hwa
    • Korean Journal of Soil Science and Fertilizer
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    • v.5 no.2
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    • pp.1-38
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    • 1972
  • This study, designed to establish a classification system of paddy soils and suitability groups on productivity and management of paddy land based on soil characteristics, has been made for the paddy soils on the Gimje-Mangyeong plains. The morphological, physical and chemical properties of the 15 paddy soil series found on these plains are briefly as follows: Ten soil series (Baeggu, Bongnam, Buyong, Gimje, Gongdeog, Honam, Jeonbug, Jisan, Mangyeong and Suam) have a B horizon (cambic B), two soil series (Geugrag and Hwadong) have a Bt horizon (argillic B), and three soil series (Gwanghwal, Hwagye and Sindab) have no B or Bt horizons. Uniquely, both the Bongnam and Gongdeog series contain a muck layer in the lower part of subsoil. Four soil series (Baeggu, Gongdeog, Gwanghwal and Sindab) generally are bluish gray and dark gray, and eight soil series (Bongnam, Buyong, Gimje, Honam, Jeonbug, Jisan, Mangyeong and Suam) are either gray or grayish brown. Three soil series (Geugrag, Hwadong and Hwagye), however, are partially gleyed in the surface and subsurface, but have a yellowish brown to brown subsoil or substrata. Seven soil series (Bongnam, Buyong, Geugrag, Gimje, Gongdeog, Honam and Hwadong) are of fine clayey texture, three soil series (Baeggu, Jeonbug and Jisan) belong to fine loamy and fine silty, three soil series (Gwanghwal, Mangyeong and Suam) to coarse loamy and coarse silty, and two soil series (Hwagye and Sindab) to sandy and sandy skeletal texture classes. The carbon content of the surface soil ranges from 0.29 to 2.18 percent, mostly 1.0 to 2.0 percent. The total nitrogen content of the surface soil ranges from 0.03 to 0.25 percent, showing a tendency to decrease irregularly with depth. The C/N ratio in the surface soil ranges from 4.6 to 15.5, dominantly from 8 to 10. The C/N ratio in the subsoil and substrata, however, has a wide range from 3.0 to 20.25. The soil reaction ranges from 4.5 to 8.0. All soil series except the Gwanghwal and Mangyeong series belong to the acid reaction class. The cation exchange cpacity in the surface soil ranges from 5 to 13 milliequivalents per 100 grams of soil, and in all the subsoil and substrata except those of a sandy texture, from 10 to 20 milliequivalents per 100 grams of soil. The base saturation of the soil series except Baeggu and Gongdeog is more than 60 percent. The active iron content of the surface soil ranges from 0.45 to 1.81 ppm, easily-reduceable manganese from 15 to 148 ppm, and available silica from 36 to 366 ppm. The iron and manganese are generally accumulated in a similar position (10 to 70cm. depth), and silica occurs in the same horizon with that of iron and manganese, or in the deeper horizons in the soil profile. The properties of each soil series extending from the sea shore towards the continental plains change with distance and they are related with distance (x) as follows: y(surface soil, clay content) = $$-0.2491x^2+6.0388x-1.1251$$ y(subsoil or subsurface soil, clay content) = $$-0.31646x^2+7.84818x-2.50008$$ y(surface soil, organic carbon content) = $$-0.0089x^2+0.2192x+0.1366$$ y(subsoil or subsurface soil, pH) = $$-0.0178x^2-0.04534x+8.3531$$ Soil profile development, soil color, depositional and organic layers, soil texture and soil reaction etc. are thought to be the major items that should be considered in a paddy soil classification. It was found that most of the soils belonging to the moderately well, somewhat poorly and poorly drained fine and medium textured soils and moderately deep fine textured soils over coarse materials, produce higher paddy yields in excess of 3,750 kg/ha. and most of the soils belonging to the coarse textured soils, well drained fine textured soils, moderately deep medium textured soils over coarse materials and saline soils, produce yields less than 3,750kg/ha. Soil texture of the profile, available soil depth, salinity and gleying of the surface and subsurface soils etc. seem to be the major factors determining rice yields, and these factors are considered when establishing suitability groups for paddy land. The great group, group, subgroup, family and series are proposed for the classification categories of paddy soils. The soil series is the basic category of the classification. The argillic horizon (Bt horizon) and cambic horizon (B horizon) are proposed as two diagnostic horizons of great group level for the determination of the morphological properties of soils in the classification. The specific soil characteristics considered in the group and subgroup levels are soil color of the profile (bluish gray, gray or yellowish brown), salinity (salic), depositonal (fluvic) and muck layers (mucky), and gleying of surface and subsurface soils (gleyic). The family levels are classified on the basis of soil reaction, soil texture and gravel content of the profile. The definitions are given on each classification category, diagnostic horizons and specific soil characteristics respectively. The soils on these plains are classified in eight subgroups and examined under the existing classification system. Further, the suitability group, can be divided into two major categories, suitability class and subclass. The soils within a suitability class are similar in potential productivity and limitation on use and management. Class 1 through 4 are distinguished from each other by combination of soil characteristics. Subclasses are divided from classes that have the same kind of dominant limitations such as slope(e), wettness(w), sandy(s), gravels(g), salinity(t) and non-gleying of the surface and subsurface soils(n). The above suitability classes and subclasses are examined, and the definitions are given. Seven subclasses are found on these plains for paddy soils. The classification and suitability group of 15 paddy soil series on the Gimje-Mangyeong plains may now be tabulated as follows.

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Modeling of Estimating Soil Moisture, Evapotranspiration and Yield of Chinese Cabbages from Meteorological Data at Different Growth Stages (기상자료(氣象資料)에 의(依)한 배추 생육시기별(生育時期別) 토양수분(土壤水分), 증발산량(蒸發散量) 및 수량(收量)의 추정모형(推定模型))

  • Im, Jeong-Nam;Yoo, Soon-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.21 no.4
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    • pp.386-408
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    • 1988
  • A study was conducted to develop a model for estimating evapotranspiration and yield of Chinese cabbages from meteorological factors from 1981 to 1986 in Suweon, Korea. Lysimeters with water table maintained at 50cm depth were used to measure the potential evapotranspiration and the maximum evapotranspiration in situ. The actual evapotranspiration and the yield were measured in the field plots irrigated with different soil moisture regimes of -0.2, -0.5, and -1.0 bars, respectively. The soil water content throughout the profile was monitored by a neutron moisture depth gauge and the soil water potentials were measured using gypsum block and tensiometer. The fresh weight of Chinese cabbages at harvest was measured as yield. The data collected in situ were analyzed to obtain parameters related to modeling. The results were summarized as followings: 1. The 5-year mean of potential evapotranspiration (PET) gradually increased from 2.38 mm/day in early April to 3.98 mm/day in mid-June, and thereafter, decreased to 1.06 mm/day in mid-November. The estimated PET by Penman, Radiation or Blanney-Criddle methods were overestimated in comparison with the measured PET, while those by Pan-evaporation method were underestimated. The correlation between the estimated and the measured PET, however, showed high significance except for July and August by Blanney-Criddle method, which implied that the coefficients should be adjusted to the Korean conditions. 2. The meteorological factors which showed hgih correlation with the measured PET were temperature, vapour pressure deficit, sunshine hours, solar radiation and pan-evaporation. Several multiple regression equations using meteorological factors were formulated to estimate PET. The equation with pan-evaporation (Eo) was the simplest but highly accurate. PET = 0.712 + 0.705Eo 3. The crop coefficient of Chinese cabbages (Kc), the ratio of the maximum evapotranspiration (ETm) to PET, ranged from 0.5 to 0.7 at early growth stage and from 0.9 to 1.2 at mid and late growth stages. The regression equation with respect to the growth progress degree (G), ranging from 0.0 at transplanting day to 1.0 at the harvesting day, were: $$Kc=0.598+0.959G-0.501G^2$$ for spring cabbages $$Kc=0.402+1.887G-1.432G^2$$ for autumn cabbages 4. The soil factor (Kf), the ratio of the actual evapotranspiration to the maximum evapotranspiration, showed 1.0 when the available soil water fraction (f) was higher than a threshold value (fp) and decreased linearly with decreasing f below fp. The relationships were: Kf=1.0 for $$f{\geq}fp$$ Kf=a+bf for f$$I{\leq}Esm$$ Es = Esm for I > Esm 6. The model for estimating actual evapotranspiration (ETa) was based on the water balance neglecting capillary rise as: ETa=PET. Kc. Kf+Es 7. The model for estimating relative yield (Y/Ym) was selected among the regression equations with the measured ETa as: Y/Ym=a+bln(ETa) The coefficients and b were 0.07 and 0.73 for spring Chinese cabbages and 0.37 and 0.66 for autumn Chinese cabbages, respectively. 8. The estimated ETa and Y/Ym were compared with the measured values to verify the model established above. The estimated ETa showed disparities within 0.29mm/day for spring Chinese cabbages and 0.19mm/day for autumn Chinese cabbages. The average deviation of the estimated relative yield were 0.14 and 0.09, respectively. 9. The deviations between the estimated values by the model and the actual values obtained from three cropping field experiments after the completion of the model calibration were within reasonable confidence range. Therefore, this model was validated to be used in practical purpose.

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Halitosis and Related Factors among Rural Residents (농촌지역 주민들의 구취실태와 유발요인)

  • Lee, Young-Ok;Hong, Jung-Pyo;Lee, Tae-Yong
    • Journal of Oral Medicine and Pain
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    • v.32 no.2
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    • pp.157-175
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    • 2007
  • This study was conducted through an interview process in which questionnaires were administered to 293 people. The questionnaires related to the behaviors of oral hygiene care, and disease history related to halitosis, and status of halitosis, halitosis measurement, oral examination, and caries activity tests such as the snyder test, Salivary flow rate test, and Salivary buffering capacity test. Our sample was taken from 293 rural residents within the period from 4th to 21st of January 2006. This was done in order to provide basic data to prepare both policies of halitosis prevention and a device to efficiently measure halitosis status and investigate the factors related therein. The major findings of this study results are as follows: 1. As for frequency of tooth brushing, twice a day occupied the greatest portion at 46.1 % Women exceeded men in frequency of tooth brushing. Tongue brushing everyday produced a 25.6 % result among subjects and The use of auxiliary oral hygiene devices occupied 9.2 %. 2. As for degree of usual self-awareness of halitosis: 62.5 %. This result also demonstrate that the severest time of self-awareness in regards to halitosis is wake up time in the morning. The time period produced the highest portion of 72.7 % in times of self-awareness. In terms of the area in which halitosis was observed, gum resulted in 23.0 %. As for types of halitosis, fetid smell was the most frequent at 37.2 %. 3. As for the result of halitosis measurement, values of OG less than 50 ppm occupied 54.3 % and $50{\sim}100ppm$ occupied 41.6 %. As for $NH_3$ values, $20{\sim}60ppm$ showed the highest value range of 52.6 %. 4. As for OG per disease history related to halitosis, values of OG were significantly high in the ranges of $50{\sim}100ppm$ within family history groups of food impaction by dental caries, diabetes mellitus and halitosis. As for values of $NH_3$, there showed a significant difference in respiratory system disease groups. 5 Value range of OG per ordinary halitosis self-awareness degree: values ranging less than 50 ppm were recorded at 55.9 % from the group realizing not aware of smell. 57.5 % from groups only realizing sometimes, while values range of $50{\sim}100ppm$ were recorded at 52.0 % from groups always aware of smell. 63.6 % from groups always strongly aware of smell. Meanwhile as for the values ranges of $NH_3$, $20{\sim}60ppm$. they occupied high portions for all groups of exams. 6. Values of OG per oral examination: the more pulp-exposed teeth and food impaction and the higher the tongue plaque index, values of OG increased within the range of $50{\sim}100ppm$. As for values of $NH_3$, the more prosthetic teeth and the higher the tongue plaque index, this value increased significantly, and the values increased up to no less than 60 ppm for groups of mandibular partial denture. 7. Within the realm of caries activity test: as for the Snyder test, high activity was highest by 43.0 % wherewith the higher the activity of acidogenic bacteria the higher the OG values. As for the salivary flow rate test, the number of cases below 8.0 ml showed the highest tendency by 62.5 %. The larger the salivary flow rate the more decreased OG values distribution. As for the salivary buffering capacity test, $6{\sim}10$ drops of 0.1N lactic acid showed the overwhelming trend by 58.7 % whereby the higher the salivary buffering capacity the greater distribution occupancy ratio of OG values below 50 ppm which is scentless to on ordinary person. 8. As for the correlation between oral environment and halitosis, OG showed the positive correlation with pulp exposed teeth, filled teeth, present teeth, tongue plaque index, and food impaction, while the negative correlation with salivary flow rate and prosthetic teeth. $NH_3$ showed a positive correlation with prosthetic teeth and frequency of tooth brushing, while decayed teeth was negative correlation. 9. As for the multiple regression analysis result, there have been selected female, pulp exposed teeth, prosthetic teeth, food impaction, salivary flow rate, tongue plaque index and severe activities in the Snyder test as factors affecting OG wherein explanatory power on it was 45.1 %. There have been selected females, pulp exposed teeth, tongue plaque index, and prosthetic teeth as factors affecting on $NH_3$ wherein explanatory power on it was 6.6 %. With the aforementioned results in mind, the status of halitosis among rural residents is considered to bare a close relation with oral environments and other factors related to halitosis such as the Snyder test from caries activity test, and salivary flow rate test. For the prevention of halitosis of residents in rural areas, we have to focus on correct tooth brushing methods and tongue brushing, with using auxiliary oral hygiene devices to remove fur of tongue plaque and food impaction. Also, when the cause and ingredients of halitosis are diverse and complex, in order to analyze exactly the factors of individual halitosis development, we need continuous and systematic study in order to provide rural residents with programs of oral hygiene education and encourage the use of dental hygienists in public health centers.