• KSBB Journal
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• v.20 no.6
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• pp.453-457
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• 2005

We investigated the effect of sulfate re-addition on hydrogen production under sulfur-deprived condition. When the final concentration of sulfate to cell suspensions($0{\sim}120{\mu}M$) was increased, chlorophyll concentration, culture density, and total amount of $H_2$ produced, increased up to an optimal concentration of $30{\mu}M\;MgSO_4$. Maximum hydrogen volume was 236 mL $H_2/L$ culture at $30{\mu}M\;MgSO_4$. However, the addition of excess sulfate(above $MgSO_4\;60{\mu}M$) delayed the start of hydrogen production and the induction of hydrogenase. Accordingly, the final yield of hydrogen production was reduced. Using these results, we attempted the continuous and sustained hydrogen production by sulfate re-addition($30{\mu}M\;MgSO_4$) using a single C. reinhardtii culture for up to 4 cycles. In total, hydrogen production volume was 625 mL $H_2/L$ culture.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1348-1353
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• 2002

The purpose of this study was to evaluate the changes and readjustment capacity in the hematological characteristics of the horse during and after a prolonged training program. One pony and two hot-blooded horses were used in this study. Resting or basal blood parameters were assessed by collecting blood samples of the animals for 1 to 2 months prior to start of the training program. Each animal was subjected to arbitrary exercise for 30 min by an automatic hot trotter and was bled at 0, 15, 30, 45 (15 min of recovery), 60 (30 min of recovery), and 75 min (45 min of recovery) after onset of exercise. All animals were exercised 3 times a week over a fivemonth period. Hematological parameters including average white blood cell counts (WBC, ${\times}$$10^3$/$\mu$l), erythrocyte concentrations (RBC, ${\times}$$10^6$/$\mu$l), hematocrit (HCT, %), mean corpuscular volume (MCV, fl), number of platelets (PLT, ${\times}$$10^4$/$\mu$l), hemoglobin concentration (Hb, g/dl), mean corpuscular hemoglobin (MCH, pg), and mean corpuscular hemoglobin concentration (MCHC, g/dl) were analyzed using an automatic cell counter. All animals showed that RBC, WBC, and HCT were significantly (p<0.05) increasing from 7.09, 8.55, and 43.5 to 8.11, 9.67, and 49.5, respectively, during the 30 min of exercise and were back to or lower than the initial basis (resting and 0 min) 30 min after exercise. However, no significant differences were detected in MCV (50.3-51.3 fl), MCH (17.2-17.4 pg), and MCHC (33.7-34.4 g/dl) values (p>0.05) regardless of the training periods. Similar trends were observed after 1, 3, 4, and 5 months of training when compared to the resting state. When these parameters were analyzed by the effect of training periods (month), mean WBC concentrations significantly reduced in the fourth and fifth month after onset of training compared to that in resting condition or the first month of training program (p<0.05). The RBC values elevated at the second month (9.40) and reaching a significantly low level (p<0.001) at the fifth month (8.62) after training compared to the first month of training (7.89). In conclusion, a mild training program enhances blood parameters gradually in both the horse and the pony. Therefore, an optimized training program is beneficial in promoting the endurance performance of the horse.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.809-822
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• 2018

A quantitative risk assessment has been introduced to quantitatively evaluate fire risk as a means of performance based fire protection design in the design of railway tunnel disaster prevention facilities. However, there are insufficient studies to examine the effect of various risk factors on the risk. Therefore, in this study, the risk assessment was conducted on the model tunnel in order to examine the effects of the evacuation start time delay and the fire growth curve on the quantitative risk assessment. As a result of the analysis of the scenario, the fatalities occurred mainly when escapes in the same direction as the direction of the fire smoke movement. In addition, after the FED exceeded 0.3, the maximum fatalities occurred within 10 minutes. In the range of relatively low risk, distance between cross passages, evacuation delay time and fire growth curve were found to affect the risk, but they were found to have little effect on the condition that the risk reached the limit. Especially, in this study, it was evaluated that the evacuation delay time reduction, fire intensity and duration reduction effect were not observed when the distance between cross passages was more than 1500 m.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.340-350
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• 2007

The objective of this study was to determine whether peroxisome proliferator-activated receptor ${\gamma}$(PPAR${\gamma}$ is involved in the regulation of weaning to estrus of primiparous sows. Twelve sows composed of 6 groups of 2 full-sibs in a similar age (325.2 d), body weight (BW; 152.4 kg) and backfat thickness (BFT; 27.0 mm) at start of lactation, were allocated to accept 31 MJ (restricted group, R-group) or 53 MJ (control group, C-group) DE/d treatment, respectively. The experimental results indicated that the low energy intake resulted in excessive losses of BW and BFT during lactation in R-group sows, which may be related to decrease of serum 15-deoxy-${\Delta}^{12,14}$-prostaglandin $J_2$ (15d-$PGJ_2$), a ligand of PPAR${\gamma}$ The obvious peak and the frequency of LH, FSH and estradiol ($E_2$) were only observed in C-group sows. Except for $E_2$ at d 1 and 2, serum FSH, LH and $E_2$ concentrations in R-group were lower than those in C-group sows after weaning. However, the serum progesterone ($P_4$) level in R-group sows was always more than that in C-group. The expression abundances of PPAR${\gamma}$and GnRH receptor (GnRH-R) in pituitary, FSH receptor (FSH-R), LH receptor (LH-R), estrogen receptor (ES-R) and aromatase in ovary of anestrous sows were lower than those of estrous sows. Neither the BFT nor the BW was associated with the mRNA abundance of PPAR${\gamma}$in hypothalamus during lactation. Expressions of PPAR${\gamma}$in pituitary and ovary were affected evidently by the BFT changes and only by the loss of BW of sows during and after lactation. Furthermore, PPAR${\gamma}$mRNA level in ovary was significantly related to the expression abundances of GnRH-R, FSH-R, ES-R and aromatase, and GnRH-R was obviously associated with PPAR${\gamma}$expression in pituitary. However, PPAR${\gamma}$expression in hypothalamus likely has no effects on these genes expression and no obvious difference for all sows. Not serum $E_2$ or $P_4$ alone but the ratios of $E_2$ to $P_4$ and 15d-$PGJ_2$ to $P_4$, and serum FSH and LH were evidently related to PPAR${\gamma}$expression in pituitary and ovary. It is concluded that PPAR${\gamma}$is associated with body conditions, reproduction hormones and their receptor expression, which affected the functions of pituitary and ovary and ultimately the estrus after weaning of primiparous sows.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.490.2-490.2
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• 2014

Since the general solar cells accept sun light at the front side, excluding the electrode area, electrons move from the emitter to the front electrode and start to collect at the grid edge. Thus the edge of gridline can be important for electrical properties of screen-printed silicon solar cells. In this study, the improvement of electrical properties in screen-printed crystalline silicon solar cells by contact treatment of grid edge was investigated. The samples with $60{\Omega}/{\square}$ and $70{\Omega}/{\square}$ emitter were prepared. After front side of samples was deposited by SiNx commercial Ag paste and Al paste were printed at front side and rear side respectively. Each sample was co-fired between $670^{\circ}C$ and $780^{\circ}C$ in the rapid thermal processing (RTP). After the firing process, the cells were dipped in 2.5% hydrofluoric acid (HF) at room temperature for various times under 60 seconds and then rinsed in deionized water. (This is called "contact treatment") After dipping in HF for a certain period, the samples from each firing condition were compared by measurement. Cell performances were measured by Suns-Voc, solar simulator, the transfer length method and a field emission scanning electron microscope. According to HF treatment, once the thin glass layer at the grid edge was etched, the current transport was changed from tunneling via Ag colloids in the glass layer to direct transport via Ag colloids between the Ag bulk and the emitter. Thus, the transfer length as well as the specific contact resistance decreased. For more details a model of the current path was proposed to explain the effect of HF treatment at the edge of the Ag grid. It is expected that HF treatment may help to improve the contact of high sheet-resistance emitter as well as the contact of a high specific contact resistance.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1268-1272
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• 2008

Low temperature plasma applied with partial oxidation is a technique to produce synthesis gas from methane. Low temperature plasma reformer has superior miniaturization and start-up characteristics to reformers using steam reforming or CO$_2$ reforming. In this research, a low temperature plasma reformer using GlidArc discharge was proposed. Reforming characteristics for each of the following variables were studied: gas components ratio (O$_2$/CH$_4$), the amount of steam, comparison of reaction on nickle and iron catalysts and the amount of CO$_2$. The optimum conditions for hydrogen production from methane was found. The maximum Hydrogen concentration of 41.1% was obtained under the following in this condition: O$_2$/C ratio of 0.64, total gas flow of 14.2 L/min, catalyst reactor temperature of 672$^{\circ}C$, the amount of steam was 0.8, reformer energy density of 1.1 kJ/L with Ni catalyst in the catalyst reactor. At this point, the methane conversion rate, hydrogen selectivity and reformer thermal efficiency were 66%, 93% and 35.2%, respectively.

• The Korean Journal of Pesticide Science
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• v.9 no.3
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• pp.221-230
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• 2005

Temperature is an important ambient factor affecting the physiology and metabolism of aquatic invertebrates. In this study, we studied about the survival, reproduction and growth effects of 4 different temperatures(16, 20, 24, $28^{\circ}C$) in four Korean cladoceran, Daphnia sp., Daphnia obtusa, Moina macrocopa, Simocephalus vetulus and Daphnia magna as an international standard species. All 5 water flea tested showed that molting time, fecundity and intrinsic rate of natural increase(r) in high temperature condition were higher than those in lower temperature. On the other hand, lower survivals and longer time to start of offspring were showed in high temperature. Our results suggest that the optimal temperatures of Daphnia sp.,, Moina macrocopa and Simocephalus vetulus seem to be about $20^{\circ}C$ except for Daphnia obtusa which as showed good survivals and reproductions in $16^{\circ}C$.

• Journal of Oriental Neuropsychiatry
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• v.14 no.2
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• pp.213-218
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• 2003

This is a case report of a patient with Tourett's disorder treated by Ukgan-san. We evaluated the patient Tourett's disorder by behavior and sound. His tic behaviors like eye blinking, shoulder shrugging, head jerking, facial frimace have been shown frequently, and His phonic tic symptoms like coughing, throat clearing, sniffing have been presented frequently, too. We diagnosed his condition as Wind-syndrome Caused by Hyperactivity of Liver-yang by patient's redish face, taut pulse, Left umbilical throb. So we treated the patient with Ukgan-san. and the score of Yale Global Tic Severity Scale(YGTSS) was 30 at the start of treatment. and the score of YGTSS was 3 at the end. We found that Ukgan-san was effective for the patient with Tourett's disorder.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.344-352
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• 2015

This study aims to identify the difference in the starting time of the dawn chorus of different species of birds and related environmental conditions. For this study, the bird songs were recorded every 2 hours a day starting from 2 hours before sunrise for a whole spring season (from April to June, 2014) in Korea. The recorded sounds were analyzed to find the starting time of each species' song by sonogram pattern using a sound analyzing program (Adobe Audition CC). To analyze the relationship between the environmental conditions and the time of the birdsong of each species, we collected the data of environmental conditions: daily precipitation, Julian date, time of sunrise and moonrise, temperature data and twilight time from the Korea Meteorological Office. As a result of this study, it was found that there are several statistical correlation between the starting time of the birdsong and environmental conditions (every environmental condition except daily precipitation and time of moonrise). Also, the difference of the starting time among each species were identified. The species were divided into 3 groups (early, mid and late) by their wake-up time. Ring-necked pheasant and yellow-throated bunting were categorized as 'Early' group and all woodpeckers were categorized as'Late' group. This study is significant as it first presented a classification of wild birds in Korea by the starting time of their dawn chorus. However, further studies are required to identify why each species to do their dawn singing at different times.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.133-133
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• 2008

Recently, as the down-scailing of field-effect transistor devices continues, Schottky-barrier field-effect transistors (SB-FETs) have attracted much attention as an alternative to conventional MOSFETs. SB-FETs have advantages over conventional devices, such as low parasitic source/drain resistance due to their metallic characteristics, low temperature processing for source/drain formation and physical scalability to the sub-10nm regime. The good scalability of SB-FETs is due to their metallic characteristics of source/drain, which leads to the low resistance and the atomically abrupt junctions at metal (silicide)-silicon interface. Nevertheless, some reports show that SB-FETs suffer from short channel effect (SCE) that would cause severe problems in the sub 20nm regime.[Ouyang et al. IEEE Trans. Electron Devices 53, 8, 1732 (2007)] Because source/drain barriers induce a depletion region, it is possible that the barriers are overlapped in short channel SB-FETs. In order to analyze the SCE of SB-FETs, we carried out systematic studies on the Schottky barrier overlapping in short channel SB-FETs using a SILVACO ATLAS numerical simulator. We have investigated the variation of surface channel band profiles depending on the doping, barrier height and the effective channel length using 2D simulation. Because the source/drain depletion regions start to be overlapped each other in the condition of the $L_{ch}$~80nm with $N_D{\sim}1\times10^{18}cm^{-3}$ and $\phi_{Bn}$ $\approx$ 0.6eV, the band profile varies as the decrease of effective channel length $L_{ch}$. With the $L_{ch}$~80nm as a starting point, the built-in potential of source/drain schottky contacts gradually decreases as the decrease of $L_{ch}$, then the conduction and valence band edges are consequently flattened at $L_{ch}$~5nm. These results may allow us to understand the performance related interdependent parameters in nanoscale SB-FETs such as channel length, the barrier height and channel doping.