• Title, Summary, Keyword: 전기

Search Result 127,897, Processing Time 0.224 seconds

Reservoir Trophic State and Empirical Model Analysis, Based on Nutrients, Transparency, and Chlorophyll-${\alpha}$ Along with Their Relations Among the Parameters (영양염류, 투명도 및 엽록소를 이용한 인공호 영양상태, 경험적 모델 분석 및 변수들 간의 상호관계)

  • An, Kwang-Guk;Kim, Jae-Kyeng;Lee, Sang-Jae
    • Korean Journal of Environmental Biology
    • /
    • v.26 no.3
    • /
    • pp.252-263
    • /
    • 2008
  • The purpose of this study was to determine trophic state, based on nutrients (TN, TP), transparency (SD), and chlorophyll-${\alpha}$ (Chl) and identify their empirical relations of TN-Chl, TP-Chl and Chl-SD depending on the dataset used along with dynamics of conductivity and suspended solids. Analysis of trophic states showed that more than half of 36 reservoirs were judged as eutrophic-hypertrophic conditions depending on the trophic variables. Seasonal values of TP varied by nearly 500% and showed greater in August than any other months. In contrast, TN varied within less than 90% and all monthly mean values of TN were never fall less than 1.2 mg L$^{-1}$ indicating low seasonal variations and high ambient concentrations (eutrophic-hypertrophic state). Analysis of empirical relations in the trophic variables showed that transparency had greater functional relations with Chl (R$^2$=0.31, p<0.001) than TP (R$^2$=0.15, p<0.001) and TN (R$^2$=0.20, p<0.001). Ratios of TN : TP in the ambient water indicated that most reservoirs showed a potential phosphorous limitation on the algal growth. Thus, algal biomass, based on Chl values, was more regulated by phosphorous than nitrogen. Analysis of linear regression model, based on log-transformed annual mean values, showed that only 30% in the variation of Chl was explained by TP (R$^2$=0.295, p=0.001, n=36) and 15% by TN (R$^2$=0.151, p=0.019, n=36). However, linear regression model, based on individual system, showed that Chl-TP model had strong positive relations (R$^2$=0.62, p=0.002, n=12), whereas the model had no any relations (p=0.892, n=12). Overall, our data suggested that averaging effect in the empirical model developments may influence the significance in the statistical analysis.

Water Quality Variation and Biotic Community Characteristics in Juam Lake (2011) (주암호의 수질 변동 및 생물군집 특성(2011))

  • Song, Hyo-Jeong;Hwang, Kyung-Sub;Park, Jong-Hwan;Lee, Hak-Young;Kim, Jong-Sun;Kim, Hyun-Woo;Lim, Dong-Ok;Lee, Sung-Hwi;Lim, Byung-Jin
    • Korean Journal of Environmental Biology
    • /
    • v.31 no.1
    • /
    • pp.37-44
    • /
    • 2013
  • This study was to investigate water quality and biotic community characteristics in Juam Lake. In water quality, water temperatures was $3.8{\sim}21.2^{\circ}C$, 6.7~8.6 in pH, $64{\sim}76{\mu}s\;cm^{-1}$ in Conductivity, $5.3{\sim}13.2mg\;L^{-1}$ in DO, $2.5{\sim}3.3mg\;L^{-1}$ in COD, $1.0{\sim}5.1mg\;L^{-1}$ in SS, $0.622{\sim}0.841mg\;L^{-1}$ in T-N, $0.007{\sim}0.019mg\;L^{-1}$ in T-P and $2.8{\sim}8.8mg\;m^{-3}$ in Chl-a. Revised Carlson's Index (TSIm) assessment using total phosphorus (TP) and chlorophyll-a domonstrated that the trophic states of Juam Lake were rated as mesotrophic. A total of 53 species of phytoplankton were identified. They were 28 Bacillariophyceae, 13 Chlorophyceae, 3 Cyanophyceae, and 9 Other algal taxa. The standing crops of phytoplankton was ranged from $113cells\;mL^{-1}$ to $2,909cells\;mL^{-1}$. A total of 16 species of zooplankton were identified (10 rotifers, 4 cladocerans and 2 copepods). Total zooplankton abundance was $309ind.\;L^{-1}$ to $435ind.\;L^{-1}$. The collected benthic macroinvertebrates from the surveyed sites in Juam Lake were 1,038 individuals, 33 species, 21 families and 12 orders. A dominant species was Uracanthella rufa and a subdominant species was Ecdyonurus kibunensis. Hydrophytes recorded from Juam Lake were identified 9 taxa. Emerged plants, floating plants among the hydrophytes was classified 8, 1 taxa, respectively. Ecosystem disturbance wildplant by Environment Ministry found were Paspalum distichum var. distichum and Ambrosia artemisiaefolia. A total of 30 species (6 families) were collected fishs from Juam Lake. There were 10 Korean endemic species (33.3% of collected species number) and 3 exotic species (10.0%).

The Study in the Composition Changes of Muscle Proteins and Amino Acids in the Hibernant Fish-Mudskipper (Boleophthalmus pectinirostris) before and after Hibernation (동면 전ㆍ후 짱뚱어의 육단백질 및 아미노산 조성의 변화에 관한 연구)

  • 박일웅
    • The Korean Journal of Food And Nutrition
    • /
    • v.16 no.3
    • /
    • pp.209-217
    • /
    • 2003
  • The composition of muscle proteins and free amino acids in the mudskipper (hibernant fish) were investigated before and after hibernation (maturity period: August, hibernation period: November thru. April). It was found that crude proteins were 17.6% in August, 17.5% in November and 16.9% in April, while among the muscle proteins, sarcoplasmic proteins were constituted up to 19.2~20.4%, 58.8~61.3% for myofibrilla proteins, 11.2~13.2% for intracellular proteins and 7.5~8.3% for stroma proteins. Composition changes of the muscle proteins were hardly noted until November but during the hibernation(from Nov. to Apr.) the amount of the sarcoplasmic proteins and the myofibrillar proteins decreased pronouncedly. As for the sarcoplasmic proteins, 14 subunits were found and among them, the amount of 30 kDa and 46 kDa subunits were found to increase slightly in April compared with those in November, while the amount of 35 kDa and 65 kDa subunits were decreased slightly. As for the myofibrilla proteins, 13 subunits were found and detectable changes in their composition were not observed until November but in April the amount of myosin heavy chain was increased by 3%, while the amount of actin decreased by 3% when those are compared with the results in November. The composition of amino acids in the muscle proteins was hardly changed during the observation period. But there were considerable changes of composition of free amino acids. Glycine and alanine were found to be the major free amino acids. The most striking feature was the changes in the glycine and arginine content: the former, which is a dominant free amino acid, was increased by two-fold in April compared with that in August and the latter was increased by two-fold in November and by four-fold in April. It was also found that the amount of essential amino acids (i.e., lysine and histidine) and others (alanine, glutamic acid, serine, aspartic acid and valine) increased significantly during the hibernation period.

Effects of Cucurbita moschata, Adlay Seed, and Cudrania tricuspidata Leaf Mixed-powder Diet Supplements on the Visceral Fat, Fecal Amount, and Serum Lipid Levels of the Rats on a High-Fat Diet (늙은 호박, 율무, 꾸지뽕잎 혼합조성물이 고지방식이를 급여한 흰쥐의 내장지방, 배변량 및 혈청지질농도에 미치는 영향)

  • Lee, Kyoung-Won;Sung, Ki-Seung;Kim, Sung-Soo;Lee, Ok-Hwan;Lee, Bog-Hieu;Han, Chan-Kyu
    • The Korean Journal of Food And Nutrition
    • /
    • v.25 no.4
    • /
    • pp.990-998
    • /
    • 2012
  • This study investigated the effects of the diet with Cucurbita moschata (CM), adlay seed (AS), and Cudrania tricuspidata leaf (CTL) mixed-powder on the visceral fat, fecal amount, and serum lipid profiles in rats fed a high-fat diet (HFD). The mixed ratio of CM, AS, and CTL as a functional food ingredient was 1:1:1 on a weight basis. Male Sprague-Dawley rats were fed a high-fat diet (D12492; 45 kcal fat) for 5 weeks during the first phase. In the second phase, which lasted 5 weeks, the rats were divided into six experimental groups. The groups were: a high-fat diet group as a control during the 10 weeks of experimental period; and a high-fat diet with 5, 10, 15, 20, and 30% mixed-powder supplement group. The adipose tissue (RFP, EFP) weights were significantly decreased in the 20% and 30% mixed-powder supplement groups than in the HFD group (p<0.05). The fecal weight produced by the 15%, 20%, and 30% mixed-powder supplement groups was significantly increased during the second phase compared to the first phase (p<0.05). In terms of serum lipids, TG (triglyceride) content was decreased in the 10% and 15% mixed-powder supplement groups. The blood glucose levels were significantly decreased in all experimental diet supplement groups than in the HFD group (p<0.05). The findings show that the high supplement groups could improve the visceral fat accumulation, fecal amount, and blood glucose content compared to the HFD group.

Availability of Cardiac Troponin T as a Marker for Detecting Perioperative Myocardial Damage in Patients with Open Heart Surgery (개심술후 발생한 심근손상에서 진단 표지자로서의 Troponin T의 임상적 유용성)

  • 김태이;정태은;이동협;이정철;한승세
    • Journal of Chest Surgery
    • /
    • v.31 no.1
    • /
    • pp.20-27
    • /
    • 1998
  • It is well known that troponin T(below TnT) is present in the myocardial cells and released during myocardial damage, so it`s very specific enzyme to myocardium. Availability of cardiac specific TnT in assessing perioperatively myocardial damage was evaluated from 34 open heart surgery patients. They consisted of 11 ischemic heart, 13 acquired valvular heart and 10 congenital heart cases. Patients were divided into two groups, group A(patients with myocardial damage) and group B(patients without myocardial damage), according to the symptom of chest pain suspecting angina and the ECG findings of ST segment and T wave changes which show myocardial ischemia and injury. Serum TnT levels were measured by enzyme immunoassay method preoperatively, immediately postoperatively, postoperative day 1, day 2, day 3, and day 7. We observed and analyzed the changes of serum TnT levels in two groups and compared the serum TnT levels with CK-MB levels measured at the same time. In group A, serum TnT levels showed 1.37$\pm$0.26$\mu$g/L, 3.16$\pm$0.66$\mu$g/L, 2.39$\pm$0.74$\mu$g/L, 2.49$\pm$0.76$\mu$g/L, and 1.23$\pm$0.60$\mu$g/L, immediate postoperatively, postoperatively day1, day2, day3, and day7, respectively. It was observed there were significant differences compared with those of group B(0.38$\pm$0.04$\mu$g/L, 0.34$\pm$0.05$\mu$g/L, 0.25$\pm$0.03$\mu$g/L, 0.24$\pm$0.04$\mu$g/L, and 0.11$\pm$0.03$\mu$g/L) during identical periods(P<0.01). Serum CK-MB level in group A significantly elevated to 145.04$\pm$35.08 IU/L on the postoperative day 1 compared to group B(31.28$\pm$5.87 IU/L, P<0.05), However, it stiffly decreased from day 2 and returned to preoperative level at day 3. When serum TnT level more than 1.0$\mu$g/L is thought to reflect myocardial damage, serum TnT had 100% of sensitivity and 87% of specificity in diagnosing the postoperative myocardial damage(p<0.01). I conclusion, serum TnT levels increased significantly at very early stage of myocardial damage and persisted much longer period than CK-MB. This suggests that serum TnT has more advantage and availability in assessing the perioperatively myocardial damage than any other tests.

  • PDF

Clinical Application of Compressed Spectral Array During Deep Hypothermia (초저체온하 대동맥수술 환자에서 완전 순환차단의 안전한 체온 및 기간에 대한 연구 - 뇌파 Compressed Spectral Array의 임상적 응용 -)

  • 장병철;유선국
    • Journal of Chest Surgery
    • /
    • v.30 no.8
    • /
    • pp.752-759
    • /
    • 1997
  • Profound hypothermia protects . cerebral function during total circulatory arrest(TCA) in the surgical treatment of a variety of cardiac and aortic diseases. Despite its importance, there is no ideal technique to monitor the brain injury from ischemia. Since 1994, we have developed compressed spectral array(CSA) of electroencephalography(EEG) and monitored cerebral activity to reduce ischemic injury. The purposes of this study are to analyse the efficacy of CSA and to establish objective criteria to consistently identify the safe level of temperature and arrest time. We studied 6 patients with aortic dissection(AD, n=3) or aortic arch aneurysm(n=3, ruptured in 2). Body temperatures from rectum and esophagus and the EEG were monitored continuously during cooling and rewarming period. TCA with cerebral ischemia was performed in 3 patients and TCA with selective cerebral perfusion was performed in 3 patients. Total ischemic time was 30, 36 and 56 minutes respectively for TCA group and selective perfusion time was 41, 56 and 92 minutes respectively for selective perfusion group. The rectal temperatures for flat EEG were between 16.1 and 22. $1^{\circ}C$ (mean: 18.4 $\pm$ 2.0): the esophageal temperatures between 12.7 and $16.4^{\circ}C$ (mean $14.7\pm1.6).$ The temperatures at which EEG reappeared $5~15.4^{\circ}C$ for esophagus. There was no neurological defic t and no surgical mortality in this series. In summary, the electrical cerebral activity Teappeared within 23 minutes at the temperature less than $16^{\circ}C$ for rectum. It seemed that $15^{\circ}C$ of esophageal temperature was not safe for 20 minutes of TCA and continuous monitoring the EEG with CSA to identify the electrocerebral silence was useful.

  • PDF

The Heart Rate and ECG Changes after Endoscopic Thoracic Sympathectomy in Patients with Primary Hyperhidrosis (원발성 다한증 환자에서 흉부 교감 신경 차단술 후의 심박동수 및 심전도 변화)

  • Kim, Jae-Jun;Kim, Young-Du;Park, Chan-Beom;Moon, Seok-Whan;Cho, Deog-Gon;Sa, Young-Jo;Seo, Jong-Hee;Kim, Chi-Kyeong
    • Journal of Chest Surgery
    • /
    • v.42 no.2
    • /
    • pp.214-219
    • /
    • 2009
  • Background: Primary focal hyperhidrosis is characterized by overactivity of the sympathetic nervous function, and this has been effectively treated with endoscopic thoracic sympathetic denervation (ESD). The imbalance of sympathetic and parasympathetic nervous system that's created by ESD may affect the heart, lung and other thoracic organs. We analyzed the heart rate and ECG changes after performing ESD at our hospital, and this is the first such study that has been conducted on this. Material and Method: Of the 263 patients who underwent ESD between October 1996 and October 2006, 130 had ECG before and after ESD, and they were classified into 3 groups according to the level of ESD: Group I (n=40) patients underwent ESD at the 2nd rib (T2ESD), Group II (n=80) at the 3rd rib (T3ESD) and Group III (n=10) at the 4th rib (T4ESD). Result: There was no mortality or major morbidity. Heart rate (HR) was significantly decreased from $71.6{\pm}10.6/min\;to\;66.8{\pm}10.2/min$ after ESD (p<0.01); however, the PR (from $148.6{\pm}21.2$ msec to $152.8{\pm}20.5$ msec) and QTc (from $399.2{\pm}15.4$ msec to $404.0{\pm}15.1$ msec) intervals were significantly increased after ESD in the patients who suffered with primary hyperhidrosis (p<0.01). According to the level of ESD, there were significant changes in the HR and QTc interval in group I (T2ESD), the HR and PR interval in group II and the QTc interval in Group III. Conclusion: There were significant changes in the heart rate and ECG findings after ESD. The thoracic sympathetic denervation of T2, T3 and T4 affected the electrical activity of the heart at the resting state.

Formation of the $CoSi_{2}$ using Co/Zr Bilayer on the Amorphous and the Single Crystalline Si Substrates (단결정과 비정질 Si 기판에서 Co/Zr 이중층을 이용한 $CoSi_{2}$ 형성)

  • Kim, Dong-Wook;Jeon, Hyeong-Tag
    • Korean Journal of Materials Research
    • /
    • v.8 no.7
    • /
    • pp.621-627
    • /
    • 1998
  • The formation of Co-silicide between Co/Zr bilayer on the amorphous and crystalline Si substrates has been investigated. The films of Zr(50$\AA$) and Co(l50$\AA$) were deposited with e-beam evaporation system and were heattreated with the rapid thermal annealing system at the temperatures between 50$0^{\circ}C$ and 80$0^{\circ}C$ with 10$0^{\circ}C$ increments for 30 seconds. The phase identification of Co-silicide was carried out by XRD and the chemical analysis was examined by AES and RBS. The interface morphologies of Co/Zr bilayer films were investigated by cross sectional TEM and HRTEM. $CoSi_2$ was formed epitaxially on the crystalline Si substrate above $700^{\circ}C$ while polycrystalline $CoSi_2$ was grown on the amorphous Si substrate. The formation temperature of Co-silicide on the amorphous Si substrate was about 100 C lower than that on the crystalline Si. The COzSi phase was not identified on the both Si substrates. The formation temperature of first phase of Co-silicide on ColZr bilayer was higher than that on Co mono layer. CoSizlayer formed on the amorphous Si substrate exhibits better uniformity compared to the CoSiz formed on the crystalline substrate. The sheet resistance of CoSiz layer on crystalline Si was lower than that on the amorphous Si at high temperatures.tures.

  • PDF

Fabrication and Characterization of $CuInSe_2$Thin Films from $In_2Se_3$ and$Cu_2Se$Precursors ($In_2Se_3$$Cu_2Se$를 이용한 $CuInSe_2$박막제조 및 특성분석)

  • Heo, Gyeong-Jae;Gwon, Se-Han;Song, Jin-Su;An, Byeong-Tae
    • Korean Journal of Materials Research
    • /
    • v.5 no.8
    • /
    • pp.988-996
    • /
    • 1995
  • CuInSe$_2$this films as a light absorber layer were fabricated by vacuum evaporation using In$_2$Se$_3$and Cu$_2$Se precursors and their properties were analyzed. Indium selenide films of 0.5${\mu}{\textrm}{m}$ thickness were first deposited by vacuum evaporation of In$_2$Se$_3$ on a Corning 7059 glass substrate. The films deposited at suscepor temperature of 40$0^{\circ}C$ showed a flat surface morphology with densely Packed grain structure. CuInSe$_2$films directly formed by evaporating Cu$_2$Se on the predeposited In$_2$Se$_2$films also showed a very flat surface when the susceptor temperature was $700^{\circ}C$. Cu$_2$Se, a second phase in the CuInSe$_2$film, was removed by evaporating additional In$_2$Se$_3$on the CuInSe$_2$film at $700^{\circ}C$. The grain size of 1.2${\mu}{\textrm}{m}$ thick CuInSe$_2$, film was about 2${\mu}{\textrm}{m}$ and the film had a (112) preferred orientation. As the amount of deposited In$_2$Se$_3$increased, the electrical resistivity of CuInSe$_2$films increased because of the decrease of hole concentration. But the optical band gap was almost constant at the value of 1.04eV, The CuInSe$_2$film grown on a Mo/glass substrate had a similar smooth microstructure compared to that on a glass substrate. A solar cell with ZnO/CdS/CuInSe$_2$/Mo structure may be realized based on the above CuInSe$_2$films.

  • PDF

Effect of Simple VSD Repair on Doppler-Derived Right Ventricular Systolic Time Interval (심실중격결손 봉합이 우심실 수축기 시간 간격에 미치는 영향)

  • 정태은;이영환
    • Journal of Chest Surgery
    • /
    • v.32 no.2
    • /
    • pp.124-129
    • /
    • 1999
  • Background: Ventricular septal defect(VSD) that causes pulmonary hypertension increase right ventricular workload. Echocardiographic assessment of right ventricular systolic time interval (RVSTI) has been used to predict pulmonary artery pressure in various cardiopulmonary diseases. This study was undertaken in infants with simple VSD to observe the alteration of the right ventricular workload through the changes of RVSTI after repair of VSD. Material and Method: We evaluated heart rate, the ratio of the left atrium/aortic root diameter (LA/Ao), right ventricular pre-ejection period(RVPEP), right ventricular ejection time(RVET), and its ratio(RVPEP/RVET) as a predictor of right ventricular workload in 12 children with simple VSD. These were measured three times at the preoperative period, at the 3 month and between 6 month and 1 year(average 9.5${\pm}$1.8month) after repair of VSD by M-mode & Doppler echocardiograph from the pulmonic valve echogram. Result: Heart rate was decreased significantly after repair(137.1${\pm}$13.7 vs 114.4${\pm}$21.1 and 104.1${\pm}$10.2, p<0.01). LA/Ao ratio was decreased significantly after repair(1.71${\pm}$0.32 vs 1.47${\pm}$0.33 and 1.39${\pm}$0.23, p<0.05). RVPEP/RVET were decreased after repair (0.38${\pm}$0.09 vs 0.32${\pm}$0.08 and 0.29${\pm}$0.09, p<0.01). Heart rate corrected RVPEP/RVET were significantly decreased only after 6 months(0.32${\pm}$0.03 vs 0.30${\pm}$0.05 and 0.28${\pm}$0.06, p<0.05). Conclusion: We found elevated right ventricular workload was progressively decreased until more than 6 months after repair and the RVSTI may serve a useful guide in postoperative care for children with VSD.

  • PDF