• Title/Summary/Keyword: AHC

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An Experimental Study on the Bond Characteristic of GFRP Bars in PVA Fiber Reinforced Activated Hwangtoh Concrete (PVA 섬유보강 황토 콘크리트에 대한 GFRP 보강근의 부착성능에 관한 실험적 연구)

  • Park, Mi-Rae;Kim, Seung-Hun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.1
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    • pp.134-141
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    • 2017
  • Many studies have been conducted with respect to the materials to replace the cement in order to reduce the carbon dioxide emissions during the cement production. Activated hwangtoh as cement replacement material goes through calcination process of $850^{\circ}C$. PVA fibers and GFRP bars are used in order to compensate for the cracks of activated hwangtoh concrete(AHC). This paper presents an experimental study investigating the bond characteristic of GFRP bars in PVA fiber reinforced AHC under tensile loads. Experimental results showed that average bond strength factor of specimens with and without PVA fiber was 2.27~2.48 and was not significantly affected by the ratio of PVA fiber andactivated hwangtoh. In addition, as the bond length was increased, the bond strength was reduced.

Morphometric Characterisation of Root-Knot Nematode Populations from Three Regions in Ghana

  • Nyaku, Seloame Tatu;Lutuf, Hanif;Cornelius, Eric
    • The Plant Pathology Journal
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    • v.34 no.6
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    • pp.544-554
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    • 2018
  • Tomato (Solanum lycopersicum) production in Ghana is limited by the root-knot nematode (Meloidogyne incognita, and yield losses over 70% have been experienced in farmer fields. Major management strategies of the root-knot nematode (RKN), such as rotation and nematicide application, and crop rotation are either little efficient and harmful to environments, with high control cost, respectively. Therefore, this study aims to examine morphometric variations of RKN populations in Ghana, using principal component analysis (PCA), of which the information can be utilized for the development of tomato cultivars resistant to RKN. Ninety (90) second-stage juveniles (J2) and 16 adult males of M. incognita were morphometrically characterized. Six and five morphometric variables were measured for adult males and second-stage juveniles (J2) respectively. Morphological measurements showed differences among the adult males and second-stage juveniles (J2). A plot of PC1 and PC2 for M. incognita male populations showed clustering into three main groups. Populations from Asuosu and Afrancho (Group I) were more closely related compared to populations from Tuobodom and Vea (Group II). There was however a single nematode from Afrancho (AF4) that fell into Group III. Biplots for male populations indicate, body length, DEGO, greatest body width, and gubernaculum length serving as variables distinguishing Group 1 and Group 2 populations. These same groupings from the PCA were reflected in the dendogram generated using Agglomerative Hierarchical Clustering (AHC). This study provides the first report on morphometric characterisation of M. incognita male and juvenile populations in Ghana showing significant morphological variation.

Effect of Dietary Fiber Sources on Chewing Activity in Sheep (섬유소 공급원이 면양의 저작행동에 미치는 영향)

  • Kim, M.H.;Lee, S.R.;Seo, I.J.;Maeng, W.J.
    • Journal of Animal Science and Technology
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    • v.49 no.5
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    • pp.639-646
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    • 2007
  • To evaluate the effect of fiber sources on chewing activity, five sheep were consecutively fed diets containing 45% of a fiber source selected from 7 tested fiber sources of alfalfa hay cube(AHC), corn cob (CC), corn silage(CS), cotton seed hull(CSH), peanut hull(PHL), rice straw(RS) and sugarcane bagasse (SCB). Number of chew showed significantly higher value in CC(p<0.001) then other sources. RS and CC had highest(p<0.01) rumination times of 352 and 367 min/d, respectively. CC also showed the highest number of chew per kg NDF intake(p<0.01), but rumination time per kg NDF intake showed no difference except CSH(p<0.001). These results suggest that chewing activities were greatly affected by the fiber sources, and therefore it should be accounted in the formulation for ruminant feed.

Fabrication of α-Alumina Nanopowders by Thermal Decomposition of Ammonium Aluminum Carbonate Hydroxide (AACH) (암모늄 알루미늄 탄산염(hhCH)의 열분해에 의한 α-알루미나 나노분말 제조)

  • O, Yong-Taeg;Shin, Dong-Chan;Kim, Sang-Woo
    • Journal of the Korean Ceramic Society
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    • v.43 no.4 s.287
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    • pp.242-246
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    • 2006
  • [ ${\alpha}-Al_2O_3$ ] nanopowders were fabricated by the thermal decomposition and synthetic of Ammonium Aluminum Carbonate Hydroxide (AACH). Crystallite size of 5 to 8 nm were fabricated when reaction temperature of AACH was low, $8^{\circ}C$, and the highest $[NH_4{^+}][AlO(OH)_n{(SO_4){^-}}_{3-n/2}][HCO_3]$ ionic concentration to pH of the Ammonium Hydrogen Carbonate (AHC) aqueous solution was 10. The phase transformation fem $NH_4Al(SO_4)_2$, rhombohedral $(Al_2(SO_4)_3)$, amorphous-, ${\theta}-,\;{\alpha}-Al_2O_3$ was examined at each temperature according to the AACH. A Time-Temperature-Transformation (TTT) diagram for thermal decomposition in air was determined. Homogeneous, spherical nanopowders with a particle size of 70 nm were obtained by firing the 5 to 8 m crystallites, which had been synthesized from AACH at pH 10 and $8^{\circ}C,\;at\;1150^{\circ}C$ for 3 h in air.

Distinct Repressive Properties of the Mammalian and Fish Orphan Nuclear Receptors SHP and DAX-1

  • Park, Yun-Yong;Teyssier, Catherine;Vanacker, Jean-Marc;Choi, Hueng-Sik
    • Molecules and Cells
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    • v.23 no.3
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    • pp.331-339
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    • 2007
  • It has been suggested that the structure and function of nuclear receptors are evolutionally conserved. Here, we compare the molecular functions of the nile tilapia (Oreochromis niloticus) small heterodimer partner (nSHP/NR0B2) and the Dosage-sensitive sex reversal AHC critical region on X chromosome gene 1 (nDAX-1/NR0B1) with those of human SHP and DAX-1 (hSHP and hDAX-1, respectively). We found that, upon transient cotransfection of human cells, nDAX-1 repressed the activity of tilapia SF-1 (nSF-1) but not that of human SF-1, although the physical interaction with human SF-1 was retained. Similarly, nSHP repressed the activity of nSF-1, whereas hSHP did not, pointing to divergent evolution of SHP/SF-1 in fish and human. We thus propose that the repressive functions of SHP and DAX-1 have been conserved in fish and mammals although with different transcriptional targets and mechanisms. These differences provide new insights into the physiological diversification of atypical orphan nuclear receptors during vertebrate evolution.

Soluble Non-ammonia Nitrogen in Ruminal and Omasal Digesta of Korean Native Steers Supplemented with Soluble Proteins

  • Choi, Chang-Weon;Kim, K.H.;Chang, S.S.;Choi, N.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.9
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    • pp.1269-1275
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    • 2012
  • An experiment was conducted to study the effect of soluble protein supplements on concentration of soluble non-ammonia nitrogen (SNAN) in the liquid phase of ruminal (RD) and omasal digesta (OD) of Korean native steers, and to investigate diurnal pattern in SNAN concentration in RD and OD. Three ruminally cannulated Korean native steers in a $3{\times}3$ Latin square design consumed a basal diet of rice straw and corn-based concentrate (control), and that supplemented (kg/d DM basis) with intact casein (0.24; IC) or acid hydrolyzed casein (0.46; AHC). Ruminal digesta was sampled using a vacuum pump, whereas OD was collected using an omasal sampling system at 2.0 h intervals after a morning feeding. The SNAN fractions (free amino acid (AA), peptide and soluble protein) in RD and OD were assessed using the ninhydrin assay. Concentrations of free AA and total SNAN in RD were significantly (p<0.05) lower than those in OD. Although free AA concentration was relatively high, mean peptide was quantitatively the most important fraction of total SNAN in both RD and OD, indicating that degradation of peptide to AA rather than hydrolysis of soluble protein to peptide or deamination may be the most limiting step in rumen proteolysis of Korean native steers. Diurnal variation in peptide concentration in OD for the soluble protein supplemented diets during the feeding cycle peaked 2 h post-feeding and decreased thereafter whereas that for the control was relatively constant during the entire feeding cycle. Diurnal variation in peptide concentration was rather similar between RD and OD.

Underdetermined Blind Source Separation from Time-delayed Mixtures Based on Prior Information Exploitation

  • Zhang, Liangjun;Yang, Jie;Guo, Zhiqiang;Zhou, Yanwei
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.2179-2188
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    • 2015
  • Recently, many researches have been done to solve the challenging problem of Blind Source Separation (BSS) problems in the underdetermined cases, and the “Two-step” method is widely used, which estimates the mixing matrix first and then extracts the sources. To estimate the mixing matrix, conventional algorithms such as Single-Source-Points (SSPs) detection only exploits the sparsity of original signals. This paper proposes a new underdetermined mixing matrix estimation method for time-delayed mixtures based on the receiver prior exploitation. The prior information is extracted from the specific structure of the complex-valued mixing matrix, which is used to derive a special criterion to determine the SSPs. Moreover, after selecting the SSPs, Agglomerative Hierarchical Clustering (AHC) is used to automaticly cluster, suppress, and estimate all the elements of mixing matrix. Finally, a convex-model based subspace method is applied for signal separation. Simulation results show that the proposed algorithm can estimate the mixing matrix and extract the original source signals with higher accuracy especially in low SNR environments, and does not need the number of sources before hand, which is more reliable in the real non-cooperative environment.

Effects of Rhodiola Rosea on Anti-Fatigue and Hypothalamic IEGs Expressions of Forced Swimming Rats (홍경천(紅景天)이 강제유영 흰쥐의 항피로 및 시상하부 IEGs 발현에 미치는 영향)

  • Ryu, Sa-Hyun;Kim, Sun-Yeou;Jung, Hyuk-Sang;Sohn, Nak-Won;Sohn, Young-Joo
    • The Korea Journal of Herbology
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    • v.23 no.4
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    • pp.9-19
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    • 2008
  • Objectives: In this study the authors investigated effects of the ethanolic extract of Rhodjola Rosea(HKC) on fatigue and hypothalamic IEG expression in rat forced swimming(FS) model. Methods: Sprague-Dawley rats were administered HKC extract(25 mg/100g, p.o.) for 3 days prior to FS, some rats underwent 10 min FS and others exhaustive forced swimming(EFS). In addition, other rats were administered extract at different times after EFS over 3 consecutive days. Results: When HKC administered before 10 mins of FS, serum actate dehydrogenase(LDH) and creatine phosphokinase(CPK) activities were significantly lower than control group. When HKC administered prior to EFS, blood lactate was significantly lower versus control group. When HKC was administered after EFS, blood lactate(at 6 and 24 hours after EFS) were significantly lower and serum LDH, CPK activities(at 24 hours after EFS) were significantly lower versus control group. When HKC was administered after EFS, c-Fos positive neurons in hypothalamic periventricular area(PVA), medial part(mPVN) and anterior hypothalamic nucleus caudal part(AHC) were significantly lower at 24 hours after EFS than in control group. HSP-72 positive neuron numbers in hypothalamus were significantly lower at 24 hours after EFS than in control group. Finally, when HKC was administered prior to 10 mins FS, HIF-$1{\alpha}$ expression in the gastrocnemius muscle was significantly increased. Conclusions: These results suggest that HKC extract has an anti-fatigue effect, and it reduces neuronal cell stress responses induced by physical stress by having a beneficial effect on lactate metabolism.

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Isolation and Chararterization of Causing Viruses from Acute Conjunctivitis Patients During Year 2001 to 2003. (2001∼2003년 유행성 눈병환자로부터 원인바이러스의 분리 및 특성)

  • 조경순;최성화;김성준;한난숙;김현찬;이윤석;박선미
    • Journal of Life Science
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    • v.14 no.4
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    • pp.620-626
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    • 2004
  • Viruses causing acute conjuntivitis were isolated from 675 patients carrying eye infections for year 2001 to 2003 in Busan reagion and their antigenic properties characterized by a serological survey. In 2001, adenoviruses (serotype 8) were found in 5 of 48 cases. In 2002, the isolated viruses were 7 adenoviruses (serotype 8 and 37), 8 coxsakieviruses (serotype A24 and B3) and 1 echoviruses (serotype 6) from 324 specimens that are known as the causative agents of acute hemorrhagic conjuctivitis (AHC). In 2003, 25 case of 303 specimens were 7 adenoviruses (serotype 3, 4, 8 and 37), 7 echoviruses (serotype 6 and 7) and 4 untypable enteroviruses. Although coxsakievirus (serotype B3) and echoviruses (serotype 6 and 7) were generally known as causative agent of aseptic meningitis, it hasn't been reported until now that they were isolated from the conjunctival swabs. The out break of AC was observed from April to October in Busan. These isolated viruses showed a strong cytophatic effects on HEp-2, RD, Vero and BGM cell strains. Analysis of electron micrograph of those viruses showed that adenovirus consists of a 80 nm diameter and nonenvloped icosahedron and then echovirus and coxsackievirus were small nonenveloped and isometric-shaped viruses. Adenovirus showing a cytophatic effect was resulted in a 458 bp single band by PCR and echovirus, coxsackievirus and untypable enterovirus were detected a 437 bp products by RT-PCR.