• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.975-976
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• 2006

The present paper is a parameter study of zinc flake production using a Simoloyer CM01 horizontal high energy rotary ball mill. The manufactured flakes have a dimension in thickness (t) < $1{\mu}m$ and diameters (d) 5-100 ${\mu}m$, consequently a ratio d/t up to 200. The flake geometry is mainly controlled by the variation of process parameters such as rotary speed of the rotor, ratio of powder/ball charge, load ratio of the system, process temperature, operating model and the quantity of process control agent (PCA). The Zn flakes were characterized by SEM, tap densitometry, laser diffraction and water coverage measurement.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.3
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• pp.161-168
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• 2002

A behavioral investigation in deer equipped with EMG telemetry system was carried out to examine the chewing behavior pattern for efficient feeding management of Korean spotted deer(Cervus nippon). There was more frequent and irregular eating and rumination behavior pattern in deer than those in other ruminants. Time spent on eating and ruminating was 261 and 291 min., respectively. Total number of boli regurgitated was 647 times per a day and deer regurgitated an average boil of 21.6 times per a rumination period. Total rumination time was 291 min. and deer have an average rumination time of 26.9 sec. per a boli. Deer had 245.3 min. for total chewing time, 20,405 times fur number of chews, 31.5 times for number of chews per bolus, and 53.4 times for number of chews per minute during rumination period. An average regurgitation bolus an hour was lower with 15.3 numbers in the 09∼15 hours subperiod and higher with 26 numbers in the 15∼21 hours subperiod and it had been gradually trended to become to low after 15∼21 hours subperiod. An average numbers of chews a bolus at every 6 hours subperiod increased gradually according to time. A deer spent 23.3 min. on eating and 26.2 min. on ruminating per 100g ingested dry matter. Consequently, since deer have a different chewing behavioral pattern to other ruminants such as more frequent and irregular eating and ruminating patterns, small bolus and low number of chew, it is likely to needed to establishment and development efficient feeding system for deer.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.198-203
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• 2003

Acetone, which is produced from butyric acid when it passes through the rumen wall, was infused into the rumen and jugular veins of three female goats to investigate the role of acetone in ruminating and masticating behavior. The ruminating behavior, as measured by the number of boli and the ruminating time, decreased (p<0.05) with intraruminal acetone infusion. However, the ruminating behavior did not change significantly in response to intravenous acetone infusion. Feed intake significantly decreased with intraruminal acetone infusion, but not with intravenous acetone infusion. The concentrations of acetone in the plasma increased significantly (p<0.05) with both acetone infusion regions. Ruminal fluid acetone, and isopropyl alcohol (IPA), which is one of the ketone bodies, produced from acetone by bacterial action in rumen, concentrations were significantly increased (p<0.05) with both acetone infusion regions. These results suggest that the chemoreceptors sensitive to acetone are more likely to be in the rumen epithelium, portal system, or liver, where they can respond to acetone levels.

• Journal of Nutrition and Health
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• v.16 no.4
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• pp.243-252
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• 1983

This study was undertaken to invesigate the effect of early nutritional deprivation and environment on neurotransmitter concentrations and behavior in later life. The restoring process of rats fed foods ad libitum after 50% restriction of the casein or the Korean diet during the prenatal and/or the lactating periods was observed. There were two rearing conditions, isolated and enriched, after weaning. Behavioral development was measured by the Y- shaped water maze and the open field test. The neurotransmitters were analyzed after sacrifice at the age of 21 weeks. The results are summarized as follows. 1) The body weight impairment by dietary restriction during the prenatal and lactating periods could be restored within 18 weeks after weaning in case of living in a classical cage. The effect of quantitative restriction was bigger in the Korean diet than in the casein diet. 2) The brain weight was decreased by nutritional deprivation. Environmental enrichment increased it slightly. 3) The concentration of neurotransmitters, norepinephrine, dopamine, and serotonin, were not shown any traces of the dietary restriction at the age of 21 weeks. 4) In the maze test, the deprived rats made more errors than the nourished and the rats fed the Korean diet more than those fed the cascin dict. The environmental enrichment could decrease the number of errors. 5) In the open field test, the dietary deprived groups showed less reaction time, more squares entered in the field, and less number of fecal boli than the nourished among the environmentally isolated rats. However, rats living in the enriched cage without experience of nutritional stress showed the lowest emotionality and the elevated exploratory activity.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1040-1048
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• 1999

Four ruminally fistulated crossbred $(Sahiwal{\times}Holstein\;Friesan)$ adult (~6 yr.) cattle of about $318{\pm}16kg$ body weight were randomly assigned in an experiment based on $4{\times}4$ latin square design to study the effect of different level of barseem (Trifolium alexendrinum) supplementation to wheat straw based diet on intake, digestion, VFA production, eating behaviour and passage rate. Four dietary treatments were wheat straw ad lib. (I), supplementation to wheat either 15(II), 30(III) or 45(IV)% of berseem. Mean total volatile fatty acids (TVFA) concentration in rumen liquor was 58.45, 66.14, 77.92 and 78.64 mmol/l. TVFA concentration in rumen liquor increased significantly (p<0.01) with increased level of berseem supplementation upon 30% level of breseem. Two peaks of TVFA concentration was observed at 4 and 8 h post feeding. Brseem supplementation showed no significant effect on daily time spent for eating, ruminating or idling, chews per minute or number of rumination boli ingested per minute. Time spent for eating and ruminating one kg neutral detergent fibre (NDF) was significantly (p<0.05) less in breseem supplemented groups. Animals in groups I, II, III and IV consumed 26, 34, 47 and 57% of DM within 1st 4 h and 64, 70, 70 and 77% of total DM within 1st 8 h of offering. All the animals consumed more than 90% of their DMI within 12 h. Active period of rumination was observed 8h post feeding reached the peak at 16 h post feeding, then declined and animals spend considerable time idling in last 4 h of 24 h feeding cycle. Berseem supplementation showed no significant effect on eating and rumination time. It is concluded that berseem supplementation upon 30% increases the efficiency of chewing during eating and rumination, which results in increase intake and TVFA production and nutrient digestibility.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.273-277
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• 1994

A $3{\times}3$ latin square design experiment was conducted to study eating and rumination behavior in sheep fed rice straw (RS) supplemented with soybean meal (SBM) and barley at three different levels of crude protein: low (40 g CP/d, LCP), medium (67 g/d, MCP) and high (94 g/d, HCP). In addition, all the supplements were formulated to contain the same amount of total digestible nutrients (TDN; 275 g). Daily time spent eating and eating rate of RS were not affected by any supplementation. However, time spent ruminating in sheep fed HCP diet was markedly shorter (p<0.05) than in those fed LCP and MCP diets. Rumination index (ruminating time/100 g DM intake) was also significantly reduced (p<0.05) by increasing level of protein supplementation. Although no significant differences were observed, the daily number of rumination periods tended to be lower, while daily number of boli regurgitated was considerably higher in sheep fed HCP diet than in those fed LCP and MCP diets. Increasing level of protein supplementation did not affect the number of chews per bolus, bolus time and rate of chewing during rumination. It is suggested that increasing level of protein supplementation was associated with more effective microbial reduction of rumen digesta particle size and consequently reduced the time spent ruminating.

• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.599-608
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• 2017

Tanshinone IIA (Tan IIA) is a pharmacologically active substance extracted from the rhizome of Salvia miltiorrhiza Bunge (also known as the Chinese herb Danshen), and is widely used to treat atherosclerosis. The pregnane X receptor (PXR) is a nuclear receptor that is a key regulator of xenobiotic and endobiotic detoxification. Tan IIA is an efficacious PXR agonist that has a potential protective effect on endothelial injuries induced by xenobiotics and endobiotics via PXR activation. Previously numerous studies have demonstrated the possible effects of Tan IIA on human umbilical vein endothelial cells, but the further mechanism for its exerts the protective effect is not well established. To study the protective effects of Tan IIA against hydrogen peroxide ($H_2O_2$) in human umbilical vein endothelial cells (HUVECs), we pretreated cells with or without different concentrations of Tan IIA for 24 h, then exposed the cells to $400{\mu}M$ $H_2O_2$ for another 3 h. Therefore, our data strongly suggests that Tan IIA may lead to increased regeneration of glutathione (GSH) from the glutathione disulfide (GSSG) produced during the GSH peroxidase-catalyzed decomposition of $H_2O_2$ in HUVECs, and the PXR plays a significant role in this process. Tan IIA may also exert protective effects against $H_2O_2$-induced apoptosis through the mitochondrial apoptosis pathway associated with the participation of PXR. Tan IIA protected HUVECs from inflammatory mediators triggered by $H_2O_2$ via PXR activation. In conclusion, Tan IIA protected HUVECs against $H_2O_2$-induced cell injury through PXR-dependent mechanisms.

• Structural Engineering and Mechanics
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• v.84 no.1
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• pp.113-127
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• 2022

Steel plate shear walls (SPSWs) are commonly utilized to provide lateral stiffness in high-rise structures. The simplified model is frequently used instead of the fine-scale model in the design of buildings with SPSWs. To predict the lateral strength of steel plate shear walls with diagonal stiffeners (DS-SPSWs), a simplified model is presented, namely the cross brace-strip model (CBSM). The bearing capacity and internal forces of columns for DS-SPSWs are calculated. In addition, a modification coefficient is introduced to account for the shear action of the thin plate. The feasibility of the CBSM is validated by comparing the numerical results with theoretical and experimental results. The numerical results from the CBSM and fine-scale model, which represent the bearing capacity of the DS-SPSW with varied stiffened plate dimensions, are in good accord with the theoretical values. The difference in bearing capacity between the CBSM and the fine-scale model is less than 1.35%. The errors of the bearing capacity from the CBSM are less than 5.67% when compared to the test results of the DS-SPSW. Furthermore, the shear and axial forces of CBSM agree with the results of the fine-scale model and theoretical analysis. As a result, the CBSM, which reflects the contribution of diagonal stiffeners to the lateral resistance of the SPSW as well as the effects on the shear and axial forces of the columns, can significantly improve the design accuracy and efficiency of buildings with DS-SPSWs.