• Korean Journal of Veterinary Research
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• v.21 no.2
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• pp.117-121
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• 1981

In order to estimate the efficiency of feed added urea-mixed zeolite the experiment was carried on in vitro. The results obtained were as follows: 1. The pH of all media added urea were inclined toward alkali, except 1% urea (included 99% zeolite) medium. 2. The concentration of ammonia in all media added urea-mixed zeolite was inversely proportional to added volume of zeolite; 1,349, 1,298, 1,255, 1,164 and $786{\mu}g/ml$ in 40%, 20%, 10%, 5% and 1% urea media respectively for 30 minutes incubation, and the concentration of ammonia in all media was increased steadily as incubation time proceeded until 9 hours. 3. The efficiency of adsorption of ammonia to zeolite of the feed added 40% urea mixture (dealing in the feed store) was hardly recognized. Accordingly, it is efficient to utilize the feed added 1~5% urea mixture, but it is of no use practica11y because they need much amount of zeolite.

• Korean Journal of Veterinary Research
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• v.22 no.2
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• pp.111-114
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• 1982

In order to explore more efficient protein substitutes by improving the utilization of non-protein nitrogen compounds in ruminants, the experiment was undertaken. The effects of sulfur coated urea (SCU) and diuredio isobutane (DUIB) in the ruminal fluid on the concentration of $NH_3-N$, the total count of the ruminal ciliates and pH value were estimated in vitro. The results obtained from the experiment were as follows: 1. The pH of the media of the group added diuredio isobutane and sulfur costed urea tends to decrease slightly at 9 hours after the incubation, but no pH changes were observed in the media added urea alone. 2. The number of the ciliates in the ruminal fluid was slightly increased 9 hours after the incubation in all groups. 3. The concentrations of $NH_3-N$ in the ruminal fluid were gradually increased according to the incubation in vitro showing 418, 431 and $627{\mu}g/ml$ in the group added diuredio isobutane and 428, 569 and $792{\mu}g/ml$ in the group added sulfur coated urea at 0, 0.5 and 9 hours after the incubation, respectively.

• Journal of Biomedical Engineering Research
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• v.3 no.1
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• pp.9-16
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• 1982

Removal of urea and vitamin B12 was simulated using two pool models with closed loop dialysis, open loop dialysis, and hemodiafiltrations with predilution and postdilulion. It was found that urea removal was limited by dialyzer clearance, however B12 removal was limited both by the resistance between ECF and ICF and by dialyzer clearance. Open loop dialysis was better than closed loop dialysis in terms of dialysate requirement and removal efficiency. Residual renal function plays an important role in removing vitamin B12. Dialysis frequency more than twice/wide does not have great effect on removal efficiency, but has the effect of reducing the difference between maximum and minimum cancentrations during dialysis period.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.291-302
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• 2020

As the properties of the melamine-urea-formaldehyde (MUF) resins were changing during their storage time, this study investigated the impacts of the synthesis method and melamine content of the MUF resins on the pH, apparent viscosity, molecular weights, and crystallinity to estimate these properties over storage times of up to 30 days. Melaminesat three addition levels (5, 10, and 20 wt% based on the resin solids) were simultaneously reacted with urea and formaldehyde (MUF-A resins), while those at the same addition levels were first reacted with formaldehyde and then with urea(MUF-B resins). The pH values of the MUF-A and MUF-B resins decreased linearly as the storage time increased; the apparent viscosity increased linearly for the low melamine contents (5% and 10%) but increased exponentially for 20%. As anticipated, the molecular weights (Mw and Mn) increased linearly with the storage time, with a steeper increase in the Mw of the MUF-B resins compared with that of the MUF-A resins. The crystallinity of the two resin types decreased with storage time at higher melamine content. The relationships between these properties and the storage time made it possible to estimate the property changes in these resins synthesized by the different synthesis methods and melamine contents; this could help predict the properties of such resins in the industry during their storage.

• Journal of ILASS-Korea
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• v.25 no.4
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• pp.178-187
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• 2020

The current emission regulations, US Tier-4 and EU Stage-V, are only able to satisfy the regulations when all currently mass-produced emission reduction technologies such as EGR, DOC, DPF, and SCR are applied. Therefore, in this study, for the application of the Urea-SCR system to non-road diesel engines, the database was established by measuring the NO, NO2 concentration and calculating the NO2/NOx ratio based on the catalyst temperature and exhaust mass flow rate. Also, based on the measured NO2/NOx ratio data, a mathematical model was proposed to predict the NO2/NOx ratio at SCR catalyst, and the suitability of the model was verified through steady-state and transient mode. As a result of comparing the NO2/NOx ratio measured at the DOC outlet under the steady-state condition to two model values separately, the R2 was 0.9811 for the 3D map model and 0.9303 for the mathematical model. And in the case of the NO2/NOx ratio measured at the DPF outlet, the R2 was 0.9797 for the 3D map model and 0.935 for the mathematical model. It was confirmed that the R2 with the model value of the 3D Map of the mathematical model in the transient mode is 0.957, which shows high reliability.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.820-826
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• 2008

Differ number of seismograph to the composition dam by recently frequent earthquake and analyzed responsiveness. Interest for dam inner place by increase of something wrong flood and inside and outside of the country earthquake appearance according to unusual change of weather is risen, on important urea in dam safety floodgate school register by structural safety divide can. Therefore, by PMP (PMF) of dam and increase of domestic earthquake occurrence, need research about earthquake resistant nature ability estimation of water resources facilities. Because responsiveness analysis applies number 0.154 ~ 0.25 g of seismograph, seismic wave that use in analysis is being suitable in dynamic analysis of construction such as Rockfill dam from representative chapter cycle faction and recommend in domestic internal examination design workbook, and use results applied much Hachinohe wave onions in van abroad.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1252-1256
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• 2006

This study estimated the effects of parity (1-3) and stage of lactation (early, mid and late) on daily milk yield (DMY), somatic cell score (SCS), milk urea nitrogen (MUN), blood glucose, and immunoglobulin G (IgG), their heritabilities and genetic correlations between them in Holsteins (n = 200). Means and standard deviations of DMY, SCS, MUN, blood glucose, and IgG in the experimental herd were $23.35{\pm}7.75kg$, $3.81{\pm}2.00$, $13.99{\pm}5.68mg/dl$, $44.91{\pm}13.12mg/dl$, and $30.36{\pm}6.72mg/ml$, respectively. DMY was the lowest in first parity, and in late lactation. SCS increased with parity; however, it was lowest in mid-lactation. MUN was lowest in first parity, and no difference was noted across stage of lactation. Blood glucose was similar between parities, however the highest blood glucose was observed during mid lactation. IgG level was significantly different between first and second parity; however, stage of lactation did not affect its level. Heritability of DMY was 0.16. Its genetic correlations with SCS and with blood glucose were -0.67 and 0.98, respectively. Heritability of SCS was 0.15. Genetic correlations of SCS with MUN, glucose, and IgG were -0.72, -0.59, and 0.68, respectively. Heritability of MUN was estimated to be 0.39 and had a genetic correlation of -0.35 with IgG. Heritabilities of blood glucose and IgG were 0.21 and 0.33, respectively. This study suggested that MUN, blood glucose and IgG could be considered important traits in future dairy selection programs to improve milk yield and its quality with better animal health and welfare. However, further studies are necessary involving more records to clarify the relationship between metabolic and immunological traits with DMY and its quality.

• Journal of Ginseng Research
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• v.30 no.3
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• pp.100-105
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• 2006

Liver and kidney are specific organs which play an active role in biotransformation and detoxification mechanisms. Ant adverse effect of chemicals or heavy metal can cause the delay or fade in these mechanisms. Present study was designed to find out the protective effect of Panax ginseng extract on renal functions altered by mercuric chloride (heavy metal) in albino rat. Fifty albino rats were divided into 10 groups. Five groups for acute study and five groups for sud-acute study viz. control group (Tween 20 and distilled water), mercuric chloride treated group (0.926 mg/kg body wt. for acute and 0.044 mg/kg body wt. for sub-acute group after calculated $LD_{50}$ (9.26 mg/kg body wt.) by probit analysis (Finney, 1971), Panax ginseng extract treated group (10 mg/kg body wt. for acute and sub-acute sets), mercuric chloride treated followed by Panax ginseng extract and Panax ginseng extract followed by mercuric chloride group. All doses were given orally by gavage tube. The result revealed that the serum urea and creatinine significantly increased in mercuric chloride treated group, while significantly decreased (p<0.01) in Panax ginseng extract group after acute and sub-acute treatment. The biochemical estimation is also confirmed by nephropathological aspect. However, the Panax ginseng extract treated followed by mercuric chloride group is more prominent than the mercuric chloride treated followed by Panax ginseng extract group. It can be concluded that Panax ginseng extract had a protective nature on renal functions against mercuric chloride toxicity in albino rats.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.13-16
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• 1998

A $2{\times}2{\times}4$ factorial study was conducted to examine the possibility of improving estimates of in vitro digestibility, using untreated (UBS) and ammonia-treated (ABS) barley straw, through homogenization of rumen fluid (RF) and by additions of urea (U) and casein (C) as N sources and Xylose + Glucose (XG) as energy sources into artificial saliva. Digestibiltiy of ABS was significantly greater than that of UBS (p < 0.001). There was a significant decrease in digestibility when additions (U, UC, UCXG) were compared with the control (p < 0.001). A 2-way interaction between RF and straw type was significant (p < 0.05) for dry matter digestibility (DMD). Homogenization of RF increased DMD of ABS (p < 0.05) whereas it decreased DMD of UBS (p > 0.05). The study showed that addition of N alone or in combination with energy sources was not better than control, rather the reverse, digestion was inhibited by a combination of U and casein (UC). It was concluded that sufficient N and branched chain fatty acids were supplied in the inoculum from sheep fed high protein grass cubes to support the growth of cellulolytic microbes during in vitro incubation. Further studies are, however, required to explore the potential of homogenization in improving the in vitro method to estimate digestibility of cereal straws.

• Advances in Traditional Medicine
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• v.5 no.1
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• pp.43-47
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• 2005

Jack bean urease was immobilized on gelatin beads with the help of glutaraldehyde. The optimum immobilization (67.6%) was obtained at 30mg/ml gelatin concentration, 0.5 mg/bead enzyme protein concentration, 1 % glutaraldehyde and at $4^{\circ}C$ incubation temperature. The $t_{1/2}$ of immobilized urease was approximately 90 days at $4^{\circ}C$ compared with $t_{1/2}$ of 20 days for the soluble urease, under identical condition. The apparent optimum pH shifted from 7.3 to 8.0 when the urease was immobilized. The optimum stability temperature of immobilized urease was found to be $60^{\circ}C$ while that of soluble urease was $45^{\circ}C$. Time-dependent thermal inactivation studies showed monophasic kinetics for soluble urease and immobilized urease at $70^{\circ}C$, respectively. The immobilized urease beads stored at $4^{\circ}C$ showed practically no leaching over a period of 30 days. Here we are presenting an easy and economical way of immobilizing urease on the gelatin beads making it suitable for various applications.