• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.237-242
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• 2001

Colostrum deprived, newborn pigs (N=12, $1.64{\pm}0.05kg$) were used to study the renal threshold of carnitine, and effects of emulsified medium-chain triglyceride (MCT, tri-8:0) feeding on kinetics of plasma carnitine and urinary carnitine excretion. An arterial catheter was inserted through an umbilical artery, and a bladder catheter was inserted via the urachus. Piglets were oro-gastrically gavaged with one of six carnitine levels (0, 60, 120, 180, 240, $480{\mu}mol/kg\;W^{0.75}$) with (+MCT) or without medium-chain triglycerides (-MCT) in 0.9% NaCl solution. Blood was sampled into heparinized tubes at 0, 1, 2, 4, 6, 8, 14, and 20 h after gavage, and urine was collected and pooled into 1 h or 2 h composite samples to determine free- and short-chain carnitine concentrations. Plasma from the 12 newborn piglets before gavage contained $10.6{\pm}1.2{\mu}mol/L$ free carnitine and $7.2{\pm}0.6{\mu}mol/L$ acid-soluble acyl carnitine. The renal threshold for carnitine was similar between the MCT and the +MCT group (42.6 13.1 and $46.4{\pm}2.0{\mu}mol/L$, respectively), but the correlation between plasma free carnitine and urinary excretion was altered. Plasma free carnitine linearly increased with increasing carnitine dosage (-MCT group, $R^2=0.95$, p<0.001; +MCT group, $R^2=0.91$, p<0.001), but was decreased by 50% when medium-chain triglycerides were fed. The peak in plasma free carnitine concentration was depressed by medium-chain triglycerides feeding also. Therefore, the plasma and urinary short-chain/free carnitine ratio of the +MCT group was increased by 100% and 40%, respectively (p<0.01). Feeding of medium-chain triglycerides may delay plasma carnitine elevation via altering the kinetics of absorption. Similarly, the plasma and urinary short-chain/free carnitine ratio were affected by interaction between medium-chain triglycerides and time (p<0.01). The present study suggests that an oral carnitine dose over $480{\mu}mol/kg\;W^{0.75}$ may be needed to reach the free carnitine renal threshold within a short period, especially when provided together with medium-chain triglyceride.

• Journal of information and communication convergence engineering
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• v.14 no.1
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• pp.40-44
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• 2016

The device coupling between the stacked top/bottom field-effect transistors (FETs) in two types of monolithic 3D inverter (M3INV) with/without a metal layer in the bottom tier is investigated, and then the regime of the thickness T_ILD and dielectric constant ε_r of the inter-layer distance (ILD), the doping concentration N_d (N_a), and length L_g of the channel, and the side-wall length L_SW where the stacked FETs are coupled are studied. When N_d (N_a) < 10¹⁶ cm^-3 and L_SW < 20 nm, the threshold voltage shift of the top FET varies almost constantly by the gate voltage of the bottom FET, but when N_d (N_a) > 10¹⁶ cm^-3 or L_SW > 20 nm, the shift decreases and increases, respectively. M3INVs with T_ILD ≥ 50 nm and ε_r ≤ 3.9 can neglect the interaction between the stacked FETs, but when T_ILD or ε_r do not meet the above conditions, the interaction must be taken into consideration.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.4
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• pp.429-439
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• 1999

In order to assess the chronic impact of tropospheric ozone on vegetation in the Seoul metropolitan area, it is necessary to quantify ozone exposure. Two ozone indices commonly used to relate ozone exposure to injury of vegetation were calculated. SUM06(SUM of hourly concentrations at or above 0.06 ppm) and AOT40(Accumulated exposure Over a Threshold of 40 ppb) which are widely used as ozone indices in the US and Europe were calculated based on hourly ozone concentrations in 5 areas of Seoul and 5 cities of Kyunggido during 1990~1997. Most SUM06 levels were 1~5ppm.hr, however several areas in Northern and Eastern Seoul reached about 5~7 ppm.hr in 1996~1997. AOT40 values were as high as 17~24 ppm.hr. Although measured SUM06 levels would not be expected to significantly impact vegetation, the overall ozone index, as well as annual average, 95th, and 99th percentile have increased continuously over the last 8 years. Often, ozone concentrations are lower in cities where there is a significant NOx concentration, than in outlying rural agricultural areas where NOx scrubbing is not as important. Concentrations greater than 40 ppb, which can cause chronic ozone toxicity to vegetation, were found mostly in the summer and constitutued about 5~15% of total hourly ozone cocentrations.

• KSBB Journal
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• v.29 no.2
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• pp.118-123
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• 2014

It was confirmed that malodor connected with an air-conditioner in an automobile is caused by microbial volatile organic compounds (MVOCs) produced by microorganisms getting into an air-conditioner when it is operating. Chemicals such as hydrogen sulfide, dimethyl sulfide, nbutyric acid, n-valeric acid, iso-valeric acid, n-octanol and toluene were detected above the odor threshold inside the automobile. The characteristics of a funky odor in the air blown into the automobile were due to detected sulfur compounds (hydrogen sulfide and dimethyl sulfide). Dimethyl sulfide was produced by microorganisms such as Aspergillus versicolor, Methylobacterium aquaticum, Herbaspirillum sp. and Acidovorax sp. In addition, the characteristics of a sour odor in the air blown into the automobile were due to detected organic acids (n-butyric acid, n-valeric acid and iso-valeric acid). N-valeric acid and iso-valeric acid were generated from Aspergillus versicolor, while iso-valeric acid was produced by Methylobacterium aquaticum. In addition, the odor intensity of the air blown into the automobile was affected by the concentration of detected sulfur compounds and organic acids. On the other hand, it is estimated that chemicals such as hydrogen sulfide, n-octanol and n-butyric acid detected in the air blown into the automobile were produced by non-identified species of microorganisms.

• Polymer(Korea)
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• v.34 no.2
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• pp.97-103
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• 2010

PMMA was grafted on MWCNT surface in order to prepare conducting film composed of 6FDAbased polyimide/MWCNT. The electrical conductivity of 6FDA-based polyimide/PMMA-g-MWCNT was investigated as a function of PMMA-g-MWCNT content. Dispersion of MWCNT in 6FDA-based polyimide composite film was better than the pristine MWCNT due to the interaction force between PMMA and 6FDA-based polyimide. Electrical conductivity was interpreted by percolation threshold theory. As a result, 6FDA-6FpDA/PMMA-g-MWCNT which have high critical exponents and low critical concentration showed better dispersion than polyimide composite material that contains DABA(diamino benzoic acid).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.91-98
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• 1993

This study was carried out to investigate characteristic of vinyl chloride emissioned from poly vinyl chloride extrusion process and to evaluate the efficiency of local exhaust ventilation system. Before local ventilation facility was constructed in poly vinyl chloride extrusion process, the average worker exposure to vinyl chloride was 3.15 ppm, which exceeded Threshold Limit Value of American Conference of Gorvernmental Industrial Hygienists (ACGIH-TLV), 1 ppm. lt is possible that vinyl chloride residues in the poly vinyl chloride resin was released or degased due to extrusion heat. The larger the width of vinyl tube become, the higher worker exposure to vinyl chloride was. It is estimated that vinyl chloride from vinyl chloride resin increased as amount of poly vinyl chloride resin extruded in the extrusion process increased. Canopy hood was an appropriate type for poly vinyl chloride resin extrusion process. This local exhaust ventilation has fan static pressure of 7.65 inch wg($190mmH_2O$, total volumetric flowlate of 4,796 CFM ($135.8m^3$/min) and fan power requirement of 12 hp (8.952 Kw). After this local exhaust ventilation was constructed there, the average concentration of worker exposure to vinyl chloride was reduced to be 0.46 ppm, which was below the Threshold Limit Value, 1 ppm. Also, the removal efficiency rate of vinyl chloride attained by local exhaust ventilation was 85.3%. It was a statistically significant (p<0.01).

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.4
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• pp.420-429
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• 2007

In this study, we attempted to evaluate the relationship between air dilution sensory test and instrumental detection method for individual odorous compound. For the purpose of our comparative study, we conducted the analysis of malodor on total of 46 samples collected from both industrial and food waste sectors using the two independent approaches. The results of instrumental analyses were explained after modification to several parameters such as: the sum of odor concentration (SOC), sum of odor quotient (SOQ) and sum of odor intensity (SOI). When we compared dilution ratio values (DRV) of threshold limit (TL) with the modified instrumental data sets, pearson coefficient of SOC, SOQ, and SOI were 0.556 (p=5.83E-05), 0.911 (p=9.64E-19) and 0.847 (p=8.93E-14), respectively. The results of this study thus suggest that the DRV of TL sensitively reflects odor strength measured intuitive.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.4 s.148
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• pp.494-503
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• 2006

Inherent damage zone model is presented to explain the fatigue properties near the fatigue limit and the crack growth threshold consistently Inherent damage zone model assumes that the stress at a point which is located at a small distance, $r_0$, an inherent length of the material that represents the size of effective damage zone, from the crack initiation position governs the fatigue characteristics regardless of the geometric configuration of the specimen; smooth specimen, notched specimen or cracked specimens with short and long crack length. A special feature of the paper is using the exact stress distributions of notched and cracked specimens at the strength evaluations. Analytical elastic solutions by Neuber and Westergaard are employed for this purpose Relationship between fatigue limit of smooth specimen and threshold stress of cracked specimen, occurrence condition of non-propagating crack at the root of elliptic notch and circular hole and relationship between stress concentration factor and fatigue notch factor are discussed quantitatively based on the proposed model.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.179-183
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• 2012

The random dopant fluctuation (RDF) effects of tunneling field-effect transistors (TFETs) have been observed by using atomistic 3-D device simulation. Due to extremely low body doping concentration, the RDF effects of TFETs have not been seriously investigated. However, in this paper, it has been found that the randomly generated and distributed source dopants increase the variation of threshold voltage ($V_{th}$), drain induced current enhancement (DICE) and subthreshold slope (SS) of TFETs. Also, some ways of relieving the RDF effects of TFETs have been presented.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.273-279
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• 2006

The performance of an autothermal thermophilic aerobic digestion (ATAD) system was studied to determine if nitrogen loss, as ammonia, was affected by an exhaust gas condenser. The system was run with and without a condenser while treating $8m^3$ of piggery slurry for 8 days. The system with a condenser (SWC) maintained the reactor temperatures above $40^{\circ}C$ for 2 days during the 8 days run, while the system without a condenser (SWOC) remained above $40^{\circ}C$ for 6 days. The SWC maintained the reactor temperatures mostly at mesophilic conditions while the SWOC at thermophilc conditions. Differences in operation conditions for the two runs were mainly caused by differences in atmospheric temperatures. Soluble chemical oxygen demand (SCOD) and volatile solids (VS) removal efficiencies of the SWC (SCOD: 62%, VS: 41%) were higher than those of the SWOC (SCOD: 40%, VS: 20%). The total Kjeldal nitrogen (TKN) removal efficiency of the SWC (7%) was less than that of the SWOC (25%). The concentration of total volatile fatty acids (VFA) in the SWC was observed to be lower than the threshold value of 0.23 g total VFA/L after 6 days, while the SWOC progressed below the threshold value after 3 days. No offensive odor emissions were observed in either run, which suggest that the use of the ATAD system may be a good odor removal strategy.