• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.668-674
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• 2013

An in vitro fermentation was conducted to determine the effects of hainanmycin on protein degradation and populations of ammonia-producing bacteria. The substrates (DM basis) for in vitro fermentation consisted of alfalfa hay (31.7%), Chinese wild rye grass hay (28.3%), ground corn grain (24.5%), soybean meal (15.5%) with a forage: concentrate of 60:40. Treatments were the control (no additive) and hainanmycin supplemented at 0.1 (H0.1), 1 (H1), 10 (H10), and 100 mg/kg (H100) of the substrates. After 24 h of fermentation, the highest addition level of hainanmycin decreased total VFA concentration and increased the final pH. The high addition level of hainanmycin (H1, H10, and H100) reduced (p<0.05) branched-chain VFA concentration, the molar proportion of acetate and butyrate, and ratio of acetate to propionate; and increased the molar proportion of propionate, except that for H1 the in molar proportion of acetate and isobutyrate was not changed (p>0.05). After 24 h of fermentation, H10 and H100 increased (p<0.05) concentrations of peptide nitrogen and AA nitrogen and proteinase activity, and decreased (p<0.05) $NH_3$-N concentration and deaminase activity compared with control. Peptidase activitives were not affected by hainanmycin. Hainanmycin supplementation only inhibited the growth of Butyrivibrio fibrisolvens, which is one of the species of low deaminative activity. Hainanmycin supplementation also decreased (p<0.05) relative population sizes of hyper-ammonia-producing species, except for H0.1 on Clostridium aminophilum. It was concluded that dietary supplementation with hainanmycin could improve ruminal fermentation and modify protein degradation by changing population size of ammonia-producing bacteria in vitro; and the addition level of 10 mg/kg appeared to achieve the best results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.3
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• pp.85-93
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• 1991

To investigate the effect of the initial sediment concentration ($C_o$) and bed shear stress (${\tau}_b$) on the settling properties of silty mud, deposition experiments were conducted in a recirculating flume using silty mud sediment taken from the Youngkwang coast which is located in the eastern Yellow Sea. The relative concentration, $C/C_o$ (C=depth averaged concentration), and the relative equilibrium concentration, $C_{eq}/C_o$ ($C_{eq}$=depth averaged concentration in the equilibrium state), have been found to depend much more strongly on the bed shear stress than initial concentration, and to increase with increasing bed shear stress. The minimum value. ${\tau}_{bmin}$, and maximum value. ${\tau}_{bmax}$, of critical bed shear stress for deposition of the Youngkwang sediment were deduced to be $0.017N/m^2$ and $1.25N/m^2$, respectively, and these values depend strongly on the properties of sediment (grain size and mineralogy). Formulas for the relative concentration and apparent median settling velocity in the range of ${\tau}_b{\geq}{\tau}_{bmin}$ were deduced. The apparent median settling velocity was found to depend much more strongly on the bed shear stress than the initial concentration and to decrease exponentially with increasing bed shear stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.246-258
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• 1988

Semi-quantitative analysis of $less-than-2{\mu}m$ clay minerals in thirty-nine superficial sediments from the Chinju Bay, southern coast of Korea, was made to reveal the distribution, provenance and dispersal pattern of fine-grained sediments. Additional nine samples were also taken from the Choryang Cheon (a river draining the kaolin-rich Hadong area) to investigate the influence of river a discharge. Grain size analysis for the Chinju Bay sediment samples was performed simultaneously as an aid to understand the sediment types and depositional environments. Except for the northeastern part, clayey mud predominates the entire bay. Average relative abundance of the four major clay minerals, I. I., illite, kaolinite, chlorite and smectite, is $55.1\%,\;23\%,\;21.5\%\;and\;0.4\%$, respectively. Although illite dominant clay mineral, the average content is about $10\~20\%$ tourer than that of the nearby continental shelf area. On the contrary, kaolinite content in the bay is about $10\%$ higher than that of the shelf area. Recent clay minerals of the Chinju Bay are mainly derived from the nearby inland area through numerous rivers and streams. Transport from shelf area, however. also seems to be important.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.66-73
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• 2005

Objectives : The purpose uf this study was to evaluate the effect of Choksmni$(ST_{36})$ moxibustion in hypertensive patients who showed sudden elevation of blood pressure. Methods : Among patients admitted to Woosuk University Hospital from June to September 2004, sixty-one patients who had shown sudden elevation in systolic blood pressure over 100mmHg were chosen by random sampling and divided into a treatment group (Choksamni moxibustion group) and a control group. In the Choksamni $(ST_{36})$ moxibustion group, moxibustion was done at the point between tibial tuberosity and head of fibula where the $ST_{36}$ is known to be located. Direct moxibustion was practiced on the patients 5 times with an increase of size from a grain of rice to a bigger cluster. Male patients were chosen to practice on the left meridian and female patients were chosen to practice on the right meridian point. Changes in blood pressure after He moxibustion were checked 4 times at tine intervals of 30 minutes. In the control group, the patients took bed rest without my medical treatment. The two groups were compared in order to demonstrate whether then were any remarkable changes in depression of blood pressure. Results : There were significant decreases in the systolic and diastolic blood pressure before and after moxibustion. We found significant decreases in systolic blood pressure at 60 minutes, 90 minutes, and 120 minutes ana diastolic blood pressure at 120 minutes in the patient group compared with the control group. Conclusions : There was a statistically significant depressing effect on blood pressure elevation observed in the group with moxibustion at $ST_{36}$ versus the control group without any medical treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.262-271
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• 2000

This study was carried out to clarify the spatial and temporal patterns of benthic environments and macrobenthos on the subtidal soft-bottom in Chonsu Bay. Seasonal surface water temperature was similar to the bottom layer, but freshwater discharges into the outlets dereased the surface salinity around the dyke in summer. Bottom dissolved oxygen was decreased deeply around the dyke and created the de-oxygenated layer during summer. Sediment grain size was consisted of finer at the neighboring of the dyke than the mouth of the bay. Organic matters including the sediment were decreased at the mouth of the bay. A total of 311 species ($769\;ind./m^2$) were identified. Polychaetes were the most abundant faunal group in the number of species and densities. The number of species revealed the spatial patterns that it was higher in the mouth of the bay, and their densities showed seasonal changes by mass recruitment occurred at the most of the area in summer, At this time, opportunistic species, Lumbrineris iongifolia and Theora fragilis, were also recruited massively. Chonsu Bay were classified into five station groups by the cluster analysis. The dominant species around the dyke were composed to opportunistic species, those in middle area were Sternaspis scutata, Paraplionospio pinnata, and those in the mouth of the bay were Mediomastus californiensis, Nephtys polybranchia. Seasonal fluctuations and spatial difference of environments seem to have influenced to the species compositions and affected to the stability of benthic ecosystems spatial-temporally In Chonsu nay.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.57-72
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• 2004

Macrobenthic fauna were studied on a tidal flat in Garolim Bay in July 2002, in order to understand their spatial distribution with the surface sediment types. Forty-nine stations were set on the tidal flat. A total of 147 species was sampled with the mean density of $1,140ind./m^2$ and the mean biomass of $157.2g/m^2$. The polychaetes were speices- and density-dominant faunal group with 64 species and the mean density of $791ind./m^2$. Mollusks were biomass-dominant faunal group with $132.0g/m^2$. Major dominant species were two polychaetes, Mediomastus californiensis with the mean density of $374ind./m^2$ and Heteromastus filiformis with $224ind./m^2$. Also mollusks such as Umbonium thomasi, Batillaria cumingi and Ruditapes philippinarum was relatively high in the mean density, showing the density of 45, 42, $32ind./m^2$ respectively. Especially, U. thomas was distributed in the mouth of the bay, where sediment grain size is rather coarse, and R. philippinarum at near tidal channel. Based on the cluster analysis, the macrobenthic community on the tidal flat was classified into seven station groups depending on the benthic environmental parameters(sediment types). Compared with other Korean tidal flats, species richness of Garolim tidal flats is more and less low.

• Korean Journal of Materials Research
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• v.20 no.12
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• pp.654-660
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• 2010

The influences of Na and K content on the crystal phase, the microstructure and the electrical property of $BaTiO_3$-based thermistors was found to show typical PTC effects. The crystal phase of powder calcined at $1000^{\circ}C$ for 4hrs showed a single phase with $BaTiO_3$, and the crystal structure was transformed from tetragonal to cubic phase according to added amounts of Na and K. In XRD results at $43^{\circ}\sim47^{\circ}$, the $(Ba_{0.858}Na_{0.071}K_{0.071})(Ti_{0.9985}Nb_{0.0015})O_{3-\delta}$ showed (002) and (200) peaks but the $(Ba_{0.762}Na_{0.119}K_{0.119})(Ti_{0.9975}Nb_{0.0025})O_{3-\delta}$ showed (002), (020) and (200) peaks. In sintered bodies, those calcined at $600^{\circ}C$ rather than at $1000^{\circ}C$ were dense, and for certain amounts of Na and K showed rapid decreases in grain size. In relative permittivity, the curie temperature due to the transformation of ferroelectric phase rose with added Na and K but decreased in terms of relative permittivity. In the result of the R-T curve, the sintered bodies have curie temperatures of about $140^{\circ}C$ and the resistivity of sintered bodies have scores of $\Omega{\cdot}cm$; the jump order of sintered bodies was shown to be more than $10^4$ in powder calcined at $1000^{\circ}C$.

• Korean Journal of Materials Research
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• v.15 no.6
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• pp.413-418
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• 2005

Perovskite $Pb(Ni_{1/3}Nb_{2/3})O_3-Pb(Zr,Ti)O_3[PNN-PZT]$ ceramics were synthesized by conventional ceramic processing technique. In order to modify piezoelectric properties for sensor application in this system, NiO addition was considered to provide $Ni^{+2}$ as an acceptor, which was known to occupy with B site in the structure. The effect of NiO addition up to $8\;mol\%$ on the following piezoelectric properties as well as sintering properties was investigated. When NiO added more than $1\;mol\%$, average grain size was decreased and second phase was found to form. Moreover, the second phase caused decrease in relative dielectric constant $(\varepsilon_{33}T/\varepsilon0)$, electro-mechanical coupling factor $(k_p)$, and piezoelectric charge constant $(d_{33})$, while increasing mechanical quality factor $(Q_m)$. When $1\;mol\%$ NiO was added, density, dielectric properties and piezoelectric properties were abruptly increased.

• Korean Journal of Materials Research
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• v.4 no.5
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• pp.524-534
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• 1994

The effects of transformation temperature and mechanical properties by thermal cycle of CuZnAl shape memory alloy with a small of misch metal and Zr contents were investigated. The addition of misch metal and Zr was very effective for reducing the grain size. After solution treatment, the specimens were post-quench aged or step quenched at $100^{\circ}C$ to $350^{\circ}C$ for variation of Rockwell hardness value. It was found that the Rockwell hareness value was very increased at $200^{\circ}C$ and $250^{\circ}C$. The fracture strength and ductility have been significantly increased with the increase of misch metal conten when tensile tested below $M_f$ temperature. Also, the fracture strength has been more increased in the case of post quench aging treatment than that of the as-quenching treatment. Aging of the $\beta$-phase decreases the $M_s$ temperature, but that of the martensite phase increases the $A_s$ temperature. The change in $A_s$ temperature with post-quench aging can be attributed to recovery of order in the $\beta$phase. The hystersis of transformation temperature ($A_s-M_s$) has an increasing tendency by thermal cycles.

• Korean Journal of Materials Research
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• v.5 no.7
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• pp.835-841
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• 1995

The deposition properties of Si$_3$N$_4$ deposited by low pressure chemical vapor deposition were studied to evaluate Si$_3$N$_4$as part of multi-layer coatings for anti-oxidation and anti-wear coating of graphite in the propellant-burning environment. Si$_3$N$_4$was deposited on the pack-SiC coated graphite and the tendencies of deposition rate and surface morphology changes with temperatures and reaction gas ratios were investigated. In low deposition temperatures the deposition rate increased tilth increasing temperature but in high temperatures the deposition rate decreased with increasing temperature. The grain size of Si$_3$N$_4$decreased with increasing temperature. In condition that the range of reaction gas ratios is 20$\leq$NH$_3$/SiH$_4$$\leq$40, the deposition rate and surface morphology did not change. The Si$_3$N$_4$deposited at 800~130$0^{\circ}C$ was amorphous, and by post-annealing at 130$0^{\circ}C$ in a $N_2$ambient, the Si$_3$N$_4$crystalized.