• Title/Summary/Keyword: WRS

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Rheological Properties of Waxy Rice Starch-Gum Mixtures in Steady and Dynamic Shear

  • Kim, Do-Dan;Lee, Young-Seung;Yoo, Byoung-Seung
    • Preventive Nutrition and Food Science
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    • v.14 no.3
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    • pp.233-239
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    • 2009
  • The effects of guar gum (GG) and xanthan gum (XG) at different concentrations (0, 0.2, 0.4, and 0.6% w/w) on the rheological properties of Korean waxy rice starch (WRS) pastes were evaluated under both steady and dynamic shear conditions. The flow properties of WRS-gum mixtures were determined from the rheological parameters of the power law model. The addition of GG and XG to WRS resulted in an increase in the apparent viscosity ($\eta_{a,100}$) and consistency index (K) values obtained from power law model. The flow behavior index (n) values of the WRS-XG mixtures decreased with an increase in gum concentration while there was only a marginal difference between n values for the WRS-GG mixtures. Dynamic moduli (G', G", and $\eta^*$) values in the WRS-gum mixture systems also increased with an increase in gum concentration. WRS-XG mixtures had higher dynamic moduli and lower tan $\delta$ (ratio of G"/G') values than WRS-GG mixtures, indicating that the higher dynamic rheological properties of WRS-XG can be attributed to an increase in the viscoelasticity of the continuous phase in the starch-gum mixture systems, which was due to the higher viscoleastic properties of XG compared to GG. The dynamic ($\eta^*$) and steady shear ($\eta_a$) viscosities of the WRS-XG paste at a 0.2% gum concentration followed the Cox-Merz superposition rule.

Data Measuring of Wayside Radio Set for GBTG System (CBTC시스템의 선로변 무선기 데이터 측정)

  • Jeong, Rag-Gyo;Chung, Sag-Gi;Yoon, Young-Ki;Park, Ki-Soo
    • Proceedings of the KIEE Conference
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    • 2006.04b
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    • pp.323-325
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    • 2006
  • CBTC 시스템에서는 선로변에에 설치된 선로변무선기(Wayside Radio Set 이하, WKS)가 상호 무선통신을 수행하고, 각 WRS간의 거리를 항상 측정하고있도록 설계되었다. CBTC지상장치가 WRS간에서 측정된 WRS간 측정거리를 SRS에서 수신하고, log의서 기록한다. 기록한 로그를 이용하여 적정값을 판단한다. 본 시험에서는 WRS간의 무선통신에서 안정적인 측정 데이터가 취득되는지를 확인하였다.

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Interferon-γ-mediated secretion of tryptophanyl-tRNA synthetases has a role in protection of human umbilical cord blood-derived mesenchymal stem cells against experimental colitis

  • Kang, Insung;Lee, Byung-Chul;Lee, Jin Young;Kim, Jae-Jun;Lee, Seung-Eun;Shin, Nari;Choi, Soon Won;Kang, Kyung-Sun
    • BMB Reports
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    • v.52 no.5
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    • pp.318-323
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    • 2019
  • Mesenchymal stem cells (MSCs) are multipotent adult stem cells that present immunosuppressive effects in experimental and clinical trials targeting various rare diseases including inflammatory bowel disease (IBD). In addition, recent studies have reported tryptophanyl-tRNA synthetase (WRS) possesses uncanonical roles such as angiostatic and anti-inflammatory effects. However, little is known about the function of WRS in MSC-based therapy. In this study, we investigated if a novel factor, WRS, secreted from MSCs has a role in amelioration of IBD symptoms and determined a specific mechanism underlying MSC therapy. Experimental colitis was induced by administration of 3% DSS solution to 8-week-old mice and human umbilical cord blood-derived MSCs (hUCB-MSCs) were injected intraperitoneally. Secretion of WRS from hUCB-MSCs and direct effect of WRS on isolated $CD4^+$ T cells was determined via in vitro experiments and hUCB-MSCs showed significant therapeutic rescue against experimental colitis. Importantly, WRS level in serum of colitis induced mice decreased and recovered by administration of MSCs. Through in vitro examination, WRS expression of hUCB-MSCs increased when cells were treated with interferon-${\gamma}$ ($IFN-{\gamma}$). WRS was evaluated and revealed to have a role in inhibiting activated T cells by inducing apoptosis. In summary, $IFN-{\gamma}$-mediated secretion of WRS from MSCs has a role in suppressive effect on excessive inflammation and disease progression of IBD and brings new highlights in the immunomodulatory potency of hUCB-MSCs.

Feed Evaluation of Whole Crop Rice Silage Harvested at Different Mature Stages in Hanwoo Steers Using In Situ Technique (In situ 방법을 이용한 수확시기별 총체벼 사일리지의 한우 생체 사료가치 평가)

  • Choi, Chang-Weon;Chung, Eui-Soo;Hong, Seong-Koo;Oh, Young-Kyoon;Kim, Jong-Geun;Lee, Sang-Cheol
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.30 no.2
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    • pp.143-150
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    • 2010
  • Three Hanwoo steers (BW $623{\pm}18.5kg$) with ruminal and duodenal cannulae were used to investigate nutrients degradability and total digestible nutrient (TDN) of whole crop rice silage (WRS) harvested at different mature stages using in situ technique. Crude protein content (mean 4.81%) decreased with progressed maturity at harvest except for WRS harvested at yellow stage. Ruminal dry matter degradability of WRS at milk stage tended to be slightly lower than that of the other stages during the entire incubation time from 12 h post-incubation. The rapidly degradable N (a-fraction) of WRS harvested at milk stage was significantly (p<0.05) higher than that of WRS at dough stage whereas the slowly degradable N (b-fraction) of WRS harvested at yellow and dough stages were statistically (p<0.05) higher than those of the other WRS. Effective protein degradability (EPD) of WRS harvested at yellow stage was numerically (compared with dough and milk stages) and statistically (compared with mature stage) higher than EPD of the other WRS. Protein digestibility of WRS at different gastric tracts did not differ (p>0.05) between the harvest stages. TDN of WRS harvested at yellow stage in Hanwoo steers was statistically (compared with milk stage) and numerically (compared with dough and mature stages) higher than TDN of the other WRS. Overall, taking present feed evaluation into consideration, WRS harvested at yellow stage may be recommended for Hanwoo steers. Further studies on in vivo rumen fermentation pattern and minimizing nutrients loss during harvest should be required for accurate feed evaluation.

Effect of Weld Residual Stress on Fatigue Analysis of Nozzle (노즐의 피로해석에 미치는 용접잔류응력의 영향)

  • Kim, Sang-Chul;Kim, Man-Won
    • Journal of Welding and Joining
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    • v.32 no.1
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    • pp.71-78
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    • 2014
  • Although the fatigue design curve of ASME Code has enough margin with respect to alternating stress and cycles, the welding residual stress(WRS) should be included in fatigue analysis. In this paper, WRS distribution in a nozzle with dissimilar metal weldment was obtained by finite element analysis and was added in fatigue analysis. The fatigue analysis was performed by following the ASME Code including thermal and stress analysis applying with postulated 30 transient conditions. The calculated results of a cumulative fatigue usage factors(CUF) were compared for the case of the models with or without WRS effects. The results showed that the CUF at weldment and heat affected zone was affected by the WRS.

A Study on Speech Recognition Estimation of Cochlea Dead Region and Amplification Gains According to Frequency Bands (주파수 영역별 Cochlea Dead Region과 증폭 이득에 따른 어음인지능력 평가 연구)

  • Park, G.S.;Bang, D.H.;Lee, S.M.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.5 no.1
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    • pp.41-46
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    • 2011
  • A sensorineural hearing loss(SNHL) occurs when the cochlea in the inner has functional problem. The region in the cochlea with no(or very few) functioning inner hair cells or neurons called 'dead regions'. Amplification using hearing aid over a frequency range corresponding to a dead region may not a beneficial. In this paper, we compared speech recognition with different location of dead region and gain and searched effective gain for hearing aid with dead region. In order to experiment, eight people who has normal hearing ware tested, and we used white noise and babble noise(SNR=0 dB). we divided by three conditions, low, mid and high frequency dead region. In addition, the gains in dead region ware 14.5 dB, 11.5dB and 6 dB gain. There ware different results by location of dead region. The result of WRS and preference in mid-frequency dead region and high-frequency dead region ware higher than them in low-frequency dead region. When we compared as gains, the score of WRS with lower gain was higher than 14.5 dB gain, and the preference was lower as higher gain.

Impact of Xanthan-locust Bean Gum Mixtures on Pasting/Paste Characteristics and Freeze-thaw Stabilities of Waxy Rice Starch (찹쌀 전분의 페이스팅/페이스트 특성 및 냉해동 안정성에 대한 잔탄검-로커스트콩검 혼합물의 영향)

  • Kim, Hyun-Seok
    • Korean Journal of Food Science and Technology
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    • v.46 no.5
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    • pp.593-600
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    • 2014
  • Normal rice starch (NRS) possesses high gelling and retrogradation tendencies, with poor freeze-thaw stability. This study investigated the effects of partial replacement of waxy rice starch (WRS) with gums on the pasting and viscoelastic properties as well as the freeze-thaw stability of the WRS paste. Xanthan gum (XAT), locust bean gum (LBG), and their mixtures were individually mixed with WRS at a ratio of 1:19 (w/w). WRS-gum mixtures were pasted using a rapid visco-analyzer at 5% total solid content, and analyzed with respect to the pasting and viscoelastic characteristics, and freeze-thaw stability. Pasting properties of WRS were retarded in pasting temperature and enhanced in pasting viscosity (although peak viscosity was varied) by partial replacement with gum and gum mixtures. Storage moduli of WRS-XAT:LBG pastes became similar to those of NRS paste with increasing angular frequency from 1 to 10 rad/s. Finally, WRS-XAT and WRS-XAT:LBG possessed more enhanced freeze-thaw stability than NRS.

Effects of Treating Whole-plant or Chopped Rice Straw Silage with Different Levels of Lactic Acid Bacteria on Silage Fermentation and Nutritive Value for Lactating Holsteins

  • Zhang, Y.G.;Xin, H.S.;Hua, J.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.12
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    • pp.1601-1607
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    • 2010
  • Two experiments were carried out to investigate i) the effects of four levels of lactic acid bacteria inoculants (LAB; 0, $2{\times}10^5$, $3{\times}10^5$ and $4{\times}10^5$ cfu/g fresh forage) and two physical forms of rice straw (whole and chopped rice straw) on silage fermentation quality and nutritive value of rice straw (RS) silage for lactating Holsteins and ii) the effects of the replacement of corn silage (CS) with different inclusion levels (0, 25 and 50%) of LAB treated RS on lactating performance of Holstein dairy cows. Rice straw packed with stretch film was ensiled for 45 d. The results showed that the higher level of LAB inoculants in the silage quadratically decreased pH, $NH_3$-N and acetic acid concentrations and increased the contents of lactic acid and total organic acids. The CP content and DM losses in the silage declined linearly as the level of LAB addition was increased. Compared with whole-plant rice straw silage (WRS), chopped rice straw silage (CRS) dramatically reduced pH by 0.83. The concentrations of $NH_3$-N were similar in WRS and CRS and both were less than 50 g/kg of total N. Chopping rice straw before ensiling significantly enhanced the lactic acid concentration and total organic acids content whereas the concentration of acetic acid declined. The CP, NDF and ADF content of CRS was 13.4, 5.9 and 10.2% lower than in WRS, respectively. Except for butyric acid concentration, significant interaction effects of inoculation level and physical form of RS were found on all fermentation end-products. Our findings indicated that milk yield and composition were not affected by different level of RS inclusion. However, because of the lower cost of WRS, cows consuming a ration in which WRS was partially substituted for CS had 3.48 Yuan (75% CS+25% WRS) and 4.56 Yuan (50% CS+50% WRS) more economic benefit over those fed a CS-based ration. It was concluded that the chopping process and LAB addition could improve the silage quality, and that substitution of corn silage with RS silage lowered the cost of the dairy cow ration without impairing lactation performance.

Development of a Hearing Impairment Simulator considering Frequency Selectivity of the Hearing Impaired (난청인의 주파수 선택도를 고려한 난청 시뮬레이터 개발)

  • Joo, S.I.;Kil, S.K.;Goh, M.S.;Lee, S.M.
    • Journal of Biomedical Engineering Research
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    • v.30 no.1
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    • pp.94-102
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    • 2009
  • In this paper, we propose a hearing impairment simulator considering reduced frequency selectivity of the hearing impaired, and verify it's performance through experiments. The reduced frequency selectivity was embodied by spectral smearing using linear prediction coding(LPC). The experiments are composed of 4 kinds of tests; pure tone test, speech reception threshold(SRT) test, and word recognition score(WRS) test without spectral smearing and with spectral smearing. The experiments of the hearing impairment simulator were performed with 9 subjects who have normal hearing. The amount of spectral smearing was controlled by LPC order. The percentile score of WRS test without smearing is $89.78{\pm}2.420%$. The scores of WRS with 24th LPC order and with 8th LPC order are $88.00{\pm}3.556%$ and $83.78{\pm}2.123%$ respectively. It is verified that WRS score is lowered by decreasing LPC order. This is a reasonable result considering that spectral smearing is getting heavier according to decreasing LPC order. It is confirmed that spectral smearing using LPC simulates the reduced frequency selectivity of the hearing impaired and affects the clearness of speech reception.

Experimental and numerical investigation of wire rope devices in base isolation systems

  • Calabrese, Andrea;Spizzuoco, Mariacristina;Losanno, Daniele;Barjani, Arman
    • Earthquakes and Structures
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    • v.18 no.3
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    • pp.275-284
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    • 2020
  • The scope of this study is the comparison between experimental results of tests performed on a base isolated building using helical wire rope isolators (WRs), and results of Nonlinear Response History Analyses (NRHAs) performed using SAP 2000, a commercial software for structural analysis. In the first stage of this research, WRs have been tested under shear deformation beyond their linear range of deformation, and analytical models have been derived to describe the nonlinear response of the bearings under different directions of loading. On the following stage, shaking table tests have been carried out on a 1/3 scale steel model isolated at the base by means of curved surface sliders (CSS) and WRs. The response of the structure under ground motion excitation has been compared to that obtained using numerical analyses in SAP 2000. The feasibility of modelling the nonlinear behavior of the tested isolation layer using multilinear link elements embedded in SAP 2000 is discussed in this paper, together with the advantages of using WRs as supplemental devices for CSSs base isolated structures.