• 제목/요약/키워드: Negative-g

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Gate Tunneling Current and QuantumEffects in Deep Scaled MOSFETs

  • Choi, Chang-Hoon;Dutton, Robert W.
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제4권1호
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    • pp.27-31
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    • 2004
  • Models and simulations of gate tunneling current for thinoxide MOSFETs and Double-Gate SOIs are discussed. A guideline in design of leaky MOS capacitors is proposed and resonant gate tunneling current in DG SOI simulated based on quantum-mechanicalmodels. Gate tunneling current in fully-depleted, double-gate SOI MOSFETs is characterized based on quantum-mechanical principles. The simulated $I_G-V_G$ of double-gate SOI has negative differential resistance like that of the resonant tunnel diodes.

Polytope와 graph에 관하여 (On polytopes and graphs)

  • 김연식
    • 한국수학교육학회지시리즈A:수학교육
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    • 제10권2호
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    • pp.4-8
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    • 1972
  • We consider the class (equation omitted) of all k-degenerate graphs, for k a non-negative integer. The class (equation omitted) and (equation omitted) are exactly the classes of totally disconnected graphs and of forests, respectively; the classes (equation omitted) and (equation omitted) properly contain all outerplanar and planar graphs respectively. The advantage of this view point is that many of the known results for chromatic number and point arboricity have natural extensions, for all larger values of k. The purpose of this note is to show that a graph G is (P$^3$)-realizable if G is planar and 3-degenerate.

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A Rabbit Model of Fat Graft Recipient Site Preconditioning Using External Negative Pressure

  • Lee, Jung Woo;Han, Yea Sik;Kim, Sin Rak;Kim, Han Kyeol;Kim, Hyun;Park, Jin Hyung
    • Archives of Plastic Surgery
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    • 제42권2호
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    • pp.150-158
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    • 2015
  • Background Fat is widely used in soft tissue augmentation. Nevertheless, it has an unpredictably high resorption rate. Clinically, external expansion with negative pressure is used to increase fat graft survival. In this study, fat graft recipient sites were preconditioned by external application of negative pressure in order to test for improvements in vascularity and fat graft survival. Methods Negative pressure was applied randomly to either the left or right dorsal ear of 20 New Zealand male white rabbits at a pressure of -125 mm Hg. The negative pressure was removed one week after the skin perfusion was measured. The skin flap at each ear was elevated, and 1 g of fat was grafted above the dorsal perichondrium. After one week, the fat weight, microvessel density, mature vessel density of the skin and fat, and amount of glycerol released were measured. Three months after the grafting, the same measurements were performed, with the exception of glycerol release. Results The fat survival rate of the experimental group ($75.4%{\pm}3.9%$) was higher than that of the control group ($53.1%{\pm}4.3%$) (P<0.001). Skin perfusion was higher in the experimental group. The glycerol release in the experimental group was significantly higher than in the control. The microvessel density of the skin and fat was significantly higher in the experimental group. Three months after the grafting, the skin and fat mature vessel density was significantly higher in the experimental groups. Conclusions Negative pressure prior to fat grafting increased the vascularity of the recipient site, and, accordingly, enhanced fat graft survival.

Variation of Anthocyanins and Isoflavones between Yellow-Cotyledon and Green-Cotyledon Seeds of Black Soybean

  • Kim, Sun-Lim;Kim, Hyun-Bok;Chi, Hee-Youn;Park, Nam-Kyu;Son, Jong-Rok;Yun, Hong-Tae;Kim, Si-Ju
    • Food Science and Biotechnology
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    • 제14권6호
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    • pp.778-782
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    • 2005
  • Analysis of black soybeans [Glycine max (L.) Merr.; 59 Korean varieties] revealed that 100-seed weights of green cotyledon seeds (33.5 g, n=31) were higher than those of yellow ones (28.9 g, n=28). Contents of delphinidin-3-glucoside (D3G), cyanidin-3-glucoside (C3G), petunidin-3-glucoside (P3G), and total anthocyanins in seed coats of black soybeans were 0.03-4.15, 0.74-18.36, 0.02-1.60, and 0.87-23.52 mg/g, respectively, among which most prominent anthocyanin was C3G (80.9% of total content), followed by D3G (13.6%) and P3G (5.5%). No significant differences were observed in color parameters $a^*$ and $b^*$ between black soybeans with yellow cotyledon (BYC) and green cotyledon (BGC). Total isoflavone content of BGC was higher than that of BYC, and negative correlation was found between total anthocyanin and isoflavone contents.

국내산 시판 어리굴(Crassostrea gigas)젓의 미생물학적 평가 (Microbiological Evaluation of Commercial Eorigul-jeot, Salt-fermented Oyster Crassostrea gigas with Seasoning, Produced in Korea)

  • 소재원;이신혜;박권삼
    • 한국수산과학회지
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    • 제57권2호
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    • pp.122-128
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    • 2024
  • We investigated the quality of 10 commercial eorigul-jeot, salt-fermented oysters with seasoning, by measuring their chemical composition and bacterial concentrations. The Eorigul-jeot had 5.07-6.06 pH (mean, 5.63), of 1.92-4.74% salinity (mean, 3.36%), 7.01-14.70 mg/100 g volatile basic nitrogen (mean, 11.91 mg/100 g), 139.22-267.11 mg/100 g amino acid nitrogen (mean, 212.69 mg/100 g), and 1.02-1.65 g/100 g total acidity (mean, 1.24 g/100 g). The total viable and lactic acid bacterial counts were 5.7×104-8.7×105 and 2.7×103-2.0×105 CFU/g, respectively, and fecal coliform was detected in only one Eorigul-jeot sample. Bacillus cereus and Clostridium perfringens were detected in two samples, and all Eorigul-jeot samples were negative for Staphylococcus aureus and Vibrio parahaemolyticus. These results strongly suggest the need to monitor food-poisoning bacteria in commercial Eorigul-jeot to ensure consumer health.

Effects of Lactitol and Tributyrin on Growth Performance, Small Intestinal Morphology and Enzyme Activity in Weaned Pigs

  • Hou, Y.Q.;Liu, Y.L.;Hu, J.;Shen, W.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권10호
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    • pp.1470-1477
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    • 2006
  • One hundred and sixty crossbred pigs ($6.62{\pm}0.36kg$) weaned at day $18{\pm}1$ were used to investigate the effects of lactitol and tributyrin on performance, small intestinal morphology and enzyme activity. The pigs were assigned to one of five dietary groups (4 pens/diet with 8 pigs/pen) and were fed the negative control diet or the negative control diet supplemented with 10 g/kg glutamine (as a positive control), or 3 g/kg lactitol (${\beta}$-D-galactopyranosyl-($1{\rightarrow}4$)-D-sorbitol), or 5 g/kg tributyrin (butanoic acid 1,2,3-propanetriyl ester), or 3 g/kg lactitol+5 g/kg tributyrin. Body weight and feed intake were measured weekly during the 4-week study. On day 7, four pigs per dietary treatment were sacrificed to examine small intestinal morphology and enzyme activity. The results showed that: (1) Compared with the negative control diet, the positive control diet improved weight gain and feed efficiency during weeks 1-2 and over the entire study (p<0.05), and also decreased duodenal and ileal crypt depth (p<0.05), but did not alter intestinal enzyme activity (p>0.05). Lactitol improved feed efficiency during weeks 3-4 and over the entire study (p<0.05), but did not improve weight gain and feed intake, intestinal morphology or enzyme activity (p>0.05). Tributyrin improved weight gain and reduced feed/gain during weeks 3-4 and over the entire study. Tributyrin significantly decreased crypt depth in the duodenum and ileum, and increased duodenal lactase and ileal maltase activity (p<0.05). Lactitol+tributyrin increased weight gain during weeks 3-4 and over the entire study, and improved feed efficiency during weeks 1-2 and 3-4 and over the entire study (p<0.05). Lactitol+tributyrin increased the jejunal villus height, and decreased the duodenal and ileal crypt depth (p<0.05). Lactitol+tributyrin also increased jejunal lactase and sucrase activity (p<0.05). (2) Compared with the positive control, tributyrin improved weight gain and reduced feed/gain during weeks 3-4 (p<0.05), decreased the ileal crypt depth, and improved the duodenal lactase and sucrase activity (p<0.05). Lactitol+ tributyrin improved weight gain during weeks 3-4, improved feed efficiency during weeks 3-4 and over the entire study, increased the ileal villus height, and increased jejunal lactase, sucrase and maltase activity (p<0.05). These results showed that tributyrin improved performance, intestinal morphology and enzyme activity, while the effect of lactitol was very limited. These results also showed that, compared with glutamine, tributyrin was more effective in improving intestinal morphology and enzyme activity, and tributyrin exerted a superior effect in improving performance as weaning progressed. These observations suggest that, as a chemical for repairing intestinal atrophy, glutamine and tributyrin should be used in the first and second periods of the starter phase, respectively.

미소접촉인쇄 공정용 철형 PDMS 스템프 제작을 위한 Pyrex 7740 glass 표면의 연성영역 나노패터닝 (Ductile-Regime Nanopatterning on Pyrex 7740 Glass Surface and Its Application to the Fabrication of Positive-tone PDMS Stamp for Microcontact Printing (${\mu}CP$))

  • 김현일;윤성원;강충길
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 추계학술대회논문집
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    • pp.40-43
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    • 2004
  • Stamps for microcontact processing are fabricated by casting elastomer such as PDMS on a master with a negative of the desired pattern. After curing, the PDMS stamp is peeled away from the master and exposed to a solution of ink and then dried. Transfer of the ink from the PDMS stamp to the substrate occurs during a brief contact between stamp and substrate. Generally, negative-tone masters, which are used for making positive-tone PDMS stamps, are fabricated by using photolithographic technique. The shortcomings of photolithography are a relative high-cost process and require extensive processing time and heavy capital investment to build and maintain the fabrication facilities. The goal of this study is to fabricate a negative-tone master by using Nano-indenter based patterning technique. Various sizes of V-grooves and U-groove were fabricated by using the combination of nanoscratch and HF isotropic etching technique. An achieved negative-tone structure was used as a master in the PDMS replica molding process to fabricate a positive-tone PDMS stamp.

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젖소 유방염(乳房炎)으로부터 Gram 음성간균(陰性桿菌)의 분리(分離) 및 약제감수성(藥劑感受性)에 관(關)한 연구(硏究) (Isolation and Drug Sensitivity of Gram-Negative Rods from Bovine Udder Infections)

  • 이차수;박청규
    • 대한수의학회지
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    • 제20권2호
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    • pp.79-84
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    • 1980
  • One hundred and eighteen cultures of Gram-negative rods isolated from cases of clinical bovine mastitis during lactation were examined for distribution of specific types, and activity of several antimicrobial agents to the isolates was determined by two-fold tube dilution method employing sterile whole milk as fluid medium. Of the isolates, 59.2% were Escherichia coli. Most of the remaining isolates were Klebsiella pneumoniae and Enterobacter aerogenes. Most Gram-negative rods(89.8%) were isolated from acute local and chronic mastitis. The cases of peracute systemic form with a marked symptoms of toxemia were associated with Escherichia coli and Klebsiella pneumoniae. The minimal lethal concentrations (MLC) of gentamicin and oxolinic acid in sterile whole milk were 16-128 times higher than the MLC obtained in trypticase soy broth (TSB), while the MLC of ampicillin and tetracycline in milk increased 2-4 times compared with TSB. Of the drugs tested, gentamicin was the most active antibiotics with MLC of $100{\mu}g/ml$ in sterile whole milk against all of Gram-negative rods isolated from bovine udder infections.

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SIMPLE MODELS TO INVESTIGATE THE EFFECT OF VELOCITY DEPENDENT FRICTION ON THE DISC BRAKE SQUEAL NOISE

  • Shin, K.;Brennan, M.J.;Joe, Y.G.;Oh, J.E.
    • International Journal of Automotive Technology
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    • 제5권1호
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    • pp.61-67
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    • 2004
  • This paper suggests two simple two-degree-of-freedom models to describe the dynamical interaction between the pad and the disc of a disc brake system. Separate models for in-plane and out -of-plane vibration are described. Although a brake pad and disc have many modes of vibration, the interaction between a single mode of each component is considered as this is thought to be crucial for brake noise. For both models, the pad and the disc are connected by a sliding friction interface having a velocity dependent friction coefficient. In this paper, it is shown that this friction model acts as negative damping in the system that describes the in-plane vibration, and as negative stiffness in system that describes the out-of-plane vibration. Stability analysis is performed to investigate the conditions under which the systems become unstable. The results of the stability analysis show that the damping is the most important parameter for in-plane vibration, whereas the stiffness is the most important parameter for the out-of-plane vibration.