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The Water Quality in the Soho Coastal Seawaters of Gamak Bay Before and After a Typhoon (가막만 소호해역에서 태풍 전후 수질 변동특성)

  • Lee Young-Sik;Moon Seong-Yong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.11 no.3
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    • pp.117-123
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    • 2006
  • The water quality before and after a typhoon was investigated as a part of a study on the increase of organic matter and on the fundamental measures to counter chemical oxygen demand (COD) in the eutrophic Soho coastal seawaters of Gamak Bay. The dissolved oxygen (DO) saturations were <54% when water column was stratified. The DO saturation was similar at surface and in the bottom layer after a typhoon $(78\sim88%)$, and a very high DO saturation (234%) was observed in the surface water after mass phytoplankton growth. The highest values of $NH_4-N,\;NO_3-N,\;PO_4-P$, and $SiO_2-Si$ were 18.22, 38.90, 1.58, and $52.10{\mu}M$, respectively, when freshwater entered after heavy rainfall events. In addition, high concentrations of $NH_4-N,\;PO_4-P$, and $SiO_2-Si$ were detected with low DO saturations in bottom water (>5m). A maximum chlorophyll (Chl.) concentration of $311.0{\mu}gl^{-1}$ was observed after typhoon, when a high-density Scrippsiella trochoidea red tide occurred with cell density of 42,000 cells $ml^{-1}$. The algal growth potential (AGP) was high after the typhoon. Nitrogen was always a limiting nutrient for phytoplankton growth. The highest COD level was $10.55mgl^{-1}$, and the main reason of the variation in COD was likely to be phytoplankton growth $(r^2=0.612,\;p=0.000)$. Organic matter, which entered the water column when the typhoon stirred the sediments, seems to have little effects on COD increase.

Development and Validation of an Official Analytical Method for Determination of Ipfencarbazone in Agricultural Products using GC-ECD (GC-ECD를 이용한 농산물 중 Ipfencarbazone의 신규분석법 개발 및 검증)

  • Jang, Jin;Kim, Heejung;Lee, Eun-Hyang;Ko, Ah-Young;Ju, Yunji;Kim, Sooyeon;Chang, Moon-Ik;Rhee, Gyu-Seek
    • The Korean Journal of Pesticide Science
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    • v.19 no.3
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    • pp.210-217
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    • 2015
  • Ipfencarbazone is a herbicide of the tetrazolinone class, and is believed to be an inhibitor of very long chain fatty acids (VLCFAs), which control cell division in weeds. The objective of this study was to develop and validate an official analytical method for ipfencarbazone determination in agricultural products. The ipfencarbazone residues in agricultural products were extracted with acetone, partitioned with n-hexane, and then purified through silica SPE cartridge. Finally, the analyte was quantified by gas chromatograph-electron capture detector (GC-ECD) and confirmed with gas chromatograph/mass spectrometer(GC/MS). The linear range of ipfencarbazone was 0.01 to 1.0 mg/L with the coefficient of determination ($r^2$) of 0.9999. The limit of detection (LOD) and quantification (LOQ) was 0.003 and 0.01 mg/kg, respectively. In addition, average recoveries of ipfencarbazone ranged from 80.6% to 112.3% at the different concentration levels LOQ, 10LOQ and 50LOQ, while the relative standard deviation was 2.2-8.6%. All values were consistent with the criteria ranges requested in the CODEX guidelines. Furthermore, and inter-laboratory study was conducted to validate the method. This proposed method for determination of ipfencarbazone residues in agricultural products can be used as an official analytical method.

Development and Validation of Analytical Method for Determination of Fungicide Spiroxamine Residue in Agricultural Commodities Using LC-MS/MS (LC-MS/MS를 이용한 농산물 중 살균제 Spiroxamine의 시험법 개발 및 검증)

  • Park, Shin-Min;Do, Jung-Ah;Lim, Seung-Hee;Yoon, Ji-Hye;Pak, Won-Min;Shin, Hye-Sun;Kuk, Ju-Hee;Chung, Hyung-Wook
    • Journal of Food Hygiene and Safety
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    • v.33 no.4
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    • pp.296-305
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    • 2018
  • Spiroxamine, one of fungicides, is used to control powdery mildew in various crops and black yellow sigatoka in bananas. The major strength of spiroxamine is to control powdery mildew in various crops and bananas yellow sigatoka in bananas. The compound has shown a high level of activity, good persistence and crop tolerance. Besides powdery mildew, good control of rust, net blotch and Rhynchosporium diseases been indicated in cereals, together with a complementary activity against Septoria diseases. In 2017, the maximum residue limit (MRL) of spiroxamine established in Korea. According to Ministry of ood and rug afety) regulations, spiroxamine residues defined only parent compound. Thus, a analytical method is needed to estimate the residue level of the parent compound. The objective of this study was to develop and validate analytical method for spiroxamine in representative agricultural commodities. Samples were extracted with acetonitrile and partitioned with dichloromethane to remove the interfering substances. The analyte were quantified and confirmed liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive-ion mode using multiple reaction monitoring (MRM). Matrix matched calibration curves were linear over the calibration ranges ($0.0005{\sim}0.1{\mu}g/mL$) for the analyte in blank extract with coefficient of determination ($r^2$) > 0.99. For validation purposes, recovery studies will be carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. The recoveries 70.6~104.6% with relative standard deviations (RSDs) less than 10%. All values were consistent with the criteria ranges in the Codex guidelines (CAC/GL40, 2003) and MFDS guidelines. proposed analytical method be used as an official analytical method in the Republic of Korea.

A Study of Different Sources and Wavelengths of Light on Laying Egg Characteristics in Laying Hens (산란계에 대한 점등 광원 및 파장 차이에 따른 산란 특성에 관한 연구)

  • Kim, Min-Ji;Choi, Hee-Chul;Suh, Ok-Suk;Chae, Hyun-Suk;Na, Jae-Cheon;Bang, Han-Tae;Kim, Dong-Wook;Kang, Hwan-Ku;Park, Sung-Bok
    • Korean Journal of Poultry Science
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    • v.37 no.4
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    • pp.383-388
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    • 2010
  • The chicken eye can discriminate light color, and different light wavelengths may affect reproduction ability. This study was carried out to identify effect of monochromatic light using light emitting diode (LED) in laying hens. Chickens were exposed to white light (WL), blue light (BL), yellow light (YL), green light (GL) and red light (RL) made by using LED as well as incandescent light (IL) (control). All light sources were equalized to a light intensity of 20 lux. The results indicated that the age of first egg laying and 50 % egg laying in laying hens treated under RL is significantly younger than under other lights (P<0.05). And the ovary weight of laying hens reared under RL is significantly heavier than under other at from 16 to 20 wks (P<0.05). The largest number of eggs production was produced in a group with treated with RL by 59 wks of age compared with any other group. The egg weight of YL was greater than other treatment groups from 26 to 45 wks (P<0.05). The egg shell from hens treated with RL was the strongest and thickest at 20 wk (P<0.05). These results suggest that the egg quality of laying hens reared in different spectrum of LED can be different and RL may enhance the laying performance.

데데킨트 절단, 배중률, 관계

  • Hong, Seong-Gi
    • Korean Journal of Logic
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    • v.7 no.2
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    • pp.15-46
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    • 2004
  • Um die rationalen Zahlen auf die reellen Zahlen zu erweitern und dadurch die Stetigkeit der reellen Zahlen sicherzustellen, hat der deutsche Mathematiker R. Dedekind im Jahr 1872 in seinem Aufsatz "Stetigkeit und Irrationale Zahlen" einen neuen mathmatischen Begriff $eingef\ddot{u}hrt,\;n\ddot{a}mlich$ 'Schnitt'. Die Menge aller rationalen Zahlen Q wird durch eine rationale Zahl a zu zwei Untermengen $A_1=\{x|x{\leq}a,\;x{\in}Q\}$, $A_2=\{x|x>a,\;x{\in}Q\}$ $vollst\ddot{a}ndig$ geteilt. Wenn wir solche Teilung, d.i. solchen Schnitt mit "$(A_1,\;A_2)$" bezeichnen, ist ein $Identit\ddot{a}tssatz$ "a=$(A_1,\;A_2)$" absolut harmlos. Analog dazu glaubt Dedekind fest, $da{\beta}$ jede irrationale Zahl mit Hilfe von einem entsprechenden Schnitt $einzuf\ddot{u}hren$ ist. Zum Beispiel, falls die zwei Mengen $B_1=\{x|x^2<2,\;x{\in}Q\}$ und $B_2=\{x|x^2>2,\;x{\in}Q\}$ gegeben sind, dann $w\ddot{a}re$ die irrationale Zahl $^{\surd}2$ mit $(B_1,\;B_2)$ gleichzusetzen. Im Fall von einem Schnitt der Menge der rationalen Zahlen durch eine rationale Zahl, $(A_1,\;A_2)$, haben die beiden Untermengen $A_1$ und $A_2$ jwewils ein Supremum und ein Infimum und beide $m\ddot{u}ssen$ identisch sein, aber -wie schon Russell in seinem Buch "Introduction to Mathmatical Philosophy" dies kritisiert- hat ein Schnitt $f\ddot{u}r$ die $Einf\ddot{u}hrung$ der irrationalen Zahl, $(B_1,\;B_2)$ keine solche $gl\ddot{u}cklichen$ Eigenschaften. Dennoch glaubt Dedekind an eine streng wissenschaftliche Fundierung der irrationalen Zahl fest, und $w\ddot{u}rde$ nach dem Grund seines Glaubens befragt, $k\ddot{o}nnte$ er nur seine Behauptung wiederholen, ein klarer Fall circulus vitiosus. Mit anderen Worten, die $L\ddot{u}cke$ zwischen $B_1$ und $B_2$ durch die $Einf\ddot{u}hrung$ einer [einzigen] wissenschaftlich fundierten irrationalen Zahl $\ddot{u}berbr\ddot{u}ckt$ und das Ganze zu einem Kontinium gemacht werden sollte, bleibt dieses Vorhaben von Dedekind erst als eine Hoffnung und dessen Resultat kann $h\ddot{o}chstens$ nur als ein Postulat, aber keineswegs als ein methodisch einwandfreier Beweis betrachtet werden. Die Probleme, die mit dem Versuch der $Einf\ddot{u}hrung$ der irrationalen Zahlen mit Hilfe von Schnitt verbunden sind, sind nicht spezifisch allein im Gebient der Mathmatik, sondern betreffen immer wieder die Rechtfertigungsfrage der $Einf\ddot{u}hrung$ der letzten Bestandteile im bezug auf eine Systemerstellung, egal ob dies System ein Wissenschaftliches oder unsere $allt\ddot{a}gliche$ Sprachhandlung ist. $F\ddot{u}r$ all diese Rechtfertigungsfragen gilt das in der klassischen Logik $g\ddot{a}ngige$ logische Prinzip tertium non datur nicht mehr, aber nicht nur wegen der von praktischen $Unm\ddot{o}glichkeit$, die unendlichen vielen $Gegenst\ddot{a}nde$ durchforschen zu $m\ddot{u}ssen$, das $hei{\beta}t$, wegen der erkenntnistheoretischen $Beschr\ddot{a}nktheit$ des jetzigen Erkenntnisniveau, sondern auch wegen des speziellen ontologischen modus der $eizuf\ddot{u}hrenden$ Objekten. Der Autor des Aufsatzes analysiert $\ddot{a}nliche$ $F\ddot{a}lle$ (das Urmeterbeispiel und die Chrakterisierungen der geometrischen Axiome von Wittgenstein), und versucht mit Hilfe von beiden Begriffen, 'interne' und 'externe' Relation, zu zeigen, $da\beta$ eine gemeinsame, invariante Struktur in den eben genannten $F\ddot{a}llen$ besteht. Am Ende des Aufsatzes setzt der Autor sich mit der logischen Argumentationsstruktur des Zitates tiber 'Grenze' aus Noten von Leonardo da Vinci auseinander, und weist auf einen $m\ddot{o}glichen$ Zusammenhang der Grundidee seienes Aufsatzes mit der Philosophie der indischen Denker $N\bar{a}g\bar{a}rjuna$ hin, obwohl die zitierten Versen aus dem Hauptwerk von $N\bar{a}g\bar{a}rjuna$, dem Mittleren Weg$(Madhyamakak\bar{a}rik\bar{a})$ nur andeutend sein $m\ddot{o}gen$.

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Emission Rate of Greenhouse Gases from Bedding Materials of Cowshed Floor: Lab-scale simulation study (우사깔짚에서 발생되는 온실가스 배출량 산정: 모의 실험결과)

  • Cho, Won Sil;Lee, Jin Eui;Park, Kyu Hyun;Kim, Jeong Dae;Ra, Chang Six
    • Journal of Animal Science and Technology
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    • v.55 no.1
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    • pp.67-74
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    • 2013
  • To know the emission amount of greenhouse gases from bedding materials of cowshed floor, the emission rates of methane ($CH_4$) and nitrous oxide ($N_2O$) gases from a simulated cowshed floor (SCF) with sawdust that manure loading rate into the bedding material could be accurately controlled were assessed in this study. The manure loading rates of Korean beef and Holstein dairy cattle into the SCF of $0.258m^2$ surface area with 10 to 15 cm height sawdust were $1.586kg/m^2/d$ and $3.588kg/m^2/d$, respectively, and those were calculated on the basis of "Standard model for sustainable livestock" and "Data for excretion amount of manure from livestock". All experiments were done in triplicates in three different seasons (May to July, Sep. to Nov., and Feb. to Apr.) using 12 SCFs. The effects of bedding material thickness on $CH_4$ and $N_2O$ emission from SCFs for both Korean beef cattle and Holstein dairy cattle were not statistically significant (p<0.05). Emission amount of $CH_4$ and $N_2O$ per square meter of SCF for Holstein dairy cattle was 7.5 and 1.2 times higher than that of Korean beef cattle, respectively. The yearly $CH_4$ amount per head was 17.7 times higher in Holstein dairy cattle, obtaining 130.4 g/head/year from SCF for Holstein dairy cattle and 7.4 g/head/year from SCF for Korean beef cattle, and $N_2O$ was also 3.8 times higher in Holstein dairy cattle (3,267 g/head/year in Korean beef cattle and 14,719 g/head/year in Holstein dairy cattle). However, the $N_2O$-N per loaded nitrogen into SCF was higher in Korean beef cattle, having 0.2148 and 0.1632 kg $N_2O$-N/kg N in Korean beef cattle and Holstein dairy cattle, respectively, and those values were 3.07 and 2.33 times higher than that of Intergovernmental Panel on Climate Change (IPCC) 2006 guideline (GL) (0.07 kg $N_2O$-N/kg N).

Development of an Analytical Method for the Determination of Pyriofenone residue in Agricultural Products using HPLC-UVD (HPLC-UVD를 이용한 농산물 중 살균제 pyriofenone 분석법 확립)

  • Park, Hyejin;Kim, HeeJung;Do, Jung-Ah;Kwon, Ji-Eun;Yoon, Ji-Young;Lee, Ji-Young;Chang, Moon-Ik;Rhee, Gyu-Seek
    • The Korean Journal of Pesticide Science
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    • v.18 no.2
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    • pp.79-87
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    • 2014
  • Pyriofenone is an aryl phenyl ketone fungicide that is newly registered in Korea in 2013 to control powdery mildew on food. The objective of this study was to develop reliable and sensitive analytical method for determination of pyriofenone residue in agricultural products for ensuring the food safety. The pyriofenone residues in all samples(Korean melon, pepper, potato, mandarin, soybean, and hulled rice) were extracted with acetonitrile, partitioned with dichloromethane, and then purified with a silica cartridge. The purified samples were analyzed by HPLC-UVD and confirmed with LC-MS. The linear range of pyriofenone was 0.05~5 mg/kg with the correlation coefficient ($r^2$) > 0.999. Average recoveries of pyriofenone ranged from 72.8% to 99.5% at the spiked level of 0.05 and 0.5 mg/kg, while the relative standard deviation was 2.3%~6.4%. In addition, the limit of detection and limit of quantification were 0.01 and 0.05 mg/kg, respectively. The results revealed that the developed and validated analytical method was suitable for pyriofenone determination in agricultural products.

A Definition of Korean Heat Waves and Their Spatio-temporal Patterns (우리나라에 적합한 열파의 정의와 그 시.공간적 발생패턴)

  • Choi, Gwang-Yong
    • Journal of the Korean Geographical Society
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    • v.41 no.5 s.116
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    • pp.527-544
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    • 2006
  • This study provides a definition of heat waves, which indicate the conditions of strong sultriness in summer, appropriate to Korea and intends to clarify long term(1973-2006) averaged spatial and temporal patterns of annual frequency of heat waves with respect to their intensity. Based on examination of the Korean mortality rate changes due to increase of apparent temperature under hot and humid summer conditions, three consecutive days with at least $32.5^{\circ}C,\;35.5^{\circ}C,\;38.5^{\circ}C,\;and\;41.5^{\circ}C$ of daily maximum Heat Index are defined as the Hot Spell(HS), the Heat Wave(HW), the Strong Heat Wave(SHW), and the Extreme Heat Wave(EHW), respectively. The annual frequency of all categories of heat waves is relatively low in high-elevated regions or on islands adjacent to seas. In contrast, the maximum annual frequency of heat waves during the study period as well as annual average frequency are highest in interior, low-elevated regions along major rivers in South Korea, particularly during the Changma Break period(between late July and mid-August). There is no obvious increasing or decreasing trend in the annual total frequency of all categories of heat waves for the study period However, the maximum annual frequencies of HS days at each weather station were recorded mainly in the 1970s, while most of maximum frequency records of both the HW and the SHW at individual weather stations were observed in the 1990s. It is also revealed that when heat waves occur in South Korea high humidity as well as high temperature contributes to increasing the heat wave intensity by $4.3-9.5^{\circ}C$. These results provide a useful basis to help develop a heat wave warning system appropriate to Korea.

Improved Acroparesthesia During Enzyme Replacement Therapy in a Patient Lately Diagnosed with Fabry Disease (진단이 지연된 Fabry 병 환자에서 효소대체요법을 통한 사지 말단 동통의 호전을 보인 1례)

  • Yang, Aram;Kim, Jinsup;Cho, Sung Yoon;Jin, Dong-Kyu
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.17 no.3
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    • pp.92-95
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    • 2017
  • Fabry disease (FD) is an X-linked lysosomal storage disorder caused by an ${\alpha}$-galactosidase A (GLA, MIM 300644) enzyme deficiency due to pathogenic variants in the ${\alpha}$-galactosidase A gene (GLA). The disease leads to accumulation of globotriaosylceramide (Gb3) and related glycophospholipids affecting nearly all major organ systems, with the primary sites damaged by Gb3 including renal glomeruli, myocardium, neurons of the dorsal ganglion and autonomic nervous system, and vascular endothelial and smooth muscle. Progressive deposition in these organ systems present with various clinical manifestations including acroparesthesia, renal failure and heart failure. Here, we report a Chinese male diagnosed with Fabry disease in his late $4^{th}$ decades showing improvement of acroparesthesia during enzyme replacement therapy (ERT). A 48-year-old Chinese man who presented with chronic recurrent severe burning pain in his fingers and toes since the age of 10, with worse involvement of the former visited to our clinic for further evaluation. His medical history included a transient ischemic attack aged 40 and diagnosed with stage 4-5 chronic kidney disease aged 47. In the family history, the patient's brother was found to be have Fabry disease 1 month before his visit. Except for his brother, all other members of the family are healthy. Based on his medical history and family history, he was strongly suspicious for Fabry disease. He was found to have a galactose-alpha-1,3-galactose level 4.96 (Reference range, 42.5-67.9) suggestive of Fabry disease. The followed sequencing of GLA coding region in our patient revealed hemizyosity for the mutation c.988C>T (Q330X) in Exon 7. Since ERT start, he showed significant improvement in his symptoms of burning sensation of fingers and toes. On the contrary, due to deteriorating kidney function even with ERT, he is considered for kidney transplantation. Despite of diagnostic delay until late 4th decades, ERT showed a potential improvement of acroparesthesia in our patient. However, late start of ERT can lead to poor outcome in multiorgan function. Therefore, early diagnosis with high index of suspicion followed by continuous ERT with regular monitoring have an impact on quality of life in Fabry disease.

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Lipid Composition of Oyster, Arkshell and Sea-mussel (굴, 피조개 및 진주담치의 지질조성에 관한 연구)

  • YOON Ho-Dong;BYUN Han-Seok;CHUN Seok-Jo;KIM Seon-Bong;PARK Yeung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.4
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    • pp.321-326
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    • 1986
  • Oyster (Crassostrea gigas), arkshell (Anadare(Scapharce) broughtonii) and sea-mussel (Mytilus edulis) were investigated as to their lipid classes. Lipid extracts from shellfishes were fractionated into neutral lipid (NL), glycolipid (GL) and phospho-lipid (PL) by column chromatography with silicic acid. The fatty acid compositions of their lipid classes and lipid fractions were determined by gas liquid chromatography (GLC). Total lipid contents of shellfishes were $3.5\%$ in the oyster, $1.4\%$ in the arkshell, $1.0\%$ in the sea-mussel. The major fatty acids of total lipids were palmitic acid, eicosapentaenoic acid and docosahexaenoic acid in the oyster and the sea-mussel, palmitic acid, oleic acid and eicosapentaenoic acid in the arkshell. The lipid composition of neutral lipid fractions in shellfishes was separated and identified as free sterol, free fatty acid, triglyceride, hydrocarbon and esterified sterol by TLC. Of these classes, triglyceride fraction was most abundant, amounting to 55.6, 77.7 and $60.4\%$ in the three samples mentioned above, respectively. The main fatty acids of glycolipid were palmitic acid, eicosaenoic acid and docosahexaenoic acid in oyster, myristic acid, palmitic acid and palmitoleic acid in the arkshell, docosahexaenoic acid, linolenic acid and palmitic acid in the sea-mussel. The major fatty acids of phospholipid were palmitic acid, eicosapentaenoic acid and docosahexaenoic acid in the oyster and sea-mussel, palmitic acid, eicosapentaenoic acid and erucic acid in the arkshell.

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