• Title/Summary/Keyword: strain accumulation

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Relations Between Self-Selected Intake of Nutrients and Body Fat Accumulation in Rats Fed Ad Libitum or for 8-hours a Day (흰쥐에게 식이를 무제한 공급 또는 공급시간을 제한하였을 때 영양소의 선택적 섭취행동과 체지방 축적과의 관계)

  • 남혜경
    • Journal of Nutrition and Health
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    • v.25 no.1
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    • pp.12-21
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    • 1992
  • This study was aimed to investigate the relations between self-selected intake of 3 macronutrie-nts and body weight gain and body fat accumulation in male rats given three isocaloric diets differing carbohydrate protein and fat contents concurrently. Also the effect of dietary restriction was observed. Forty two male rats of Sprague-Dawley strain weighing 68.7$\pm$6.1g were randomly divided into 2 groups and were allowed to have foods from 3 different cups for 8-hours a day or ad libitum, After 12 weeksthey were decapitated and their brains were quickly removed and frozen until they were assayed for serotonin and its metabolite 5-HIAA The carcass was dried at 105$\pm$2$^{\circ}C$ and measured the contents of body water and body fat. The animals chose a moderately high and constant carbohydrate level and showed the increase of percent protein intake with age and great individual variations. Protein in the diet seemed to trigger appetite and increase food intake which resulted in higher weight gains and in more fat deposition in the body. The concentration of brain serotonin did not show any correlations with the intake of nutrients. the accumulation of body fat and the gain of body weight.

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Optimum actuator placement for damping of vibrations using the Prestress-Accumulation Release control approach

  • Poplawski, Blazej;Mikulowski, Grzegorz;Pisarski, Dominik;Wiszowaty, Rafal;Jankowski, Lukasz
    • Smart Structures and Systems
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    • v.24 no.1
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    • pp.27-35
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    • 2019
  • This paper proposes a quantitative criterion for optimization of actuator placement for the Prestress-Accumulation Release (PAR) strategy of mitigation of vibrations. The PAR strategy is a recently developed semi-active control approach that relies on controlled redistribution of vibration energy into high-order modes, which are high-frequency and thus effectively dissipated by means of the natural mechanisms of material damping. The energy transfer is achieved by a controlled temporary removal of selected structural constraints. This paper considers a short-time decoupling of rotational degrees of freedom in a frame node so that the bending moments temporarily cease to be transferred between the involved beams. We propose and test a quantitative criterion for placement of such actuators. The criterion is based on local modal strain energy that can be released into high-order modes. The numerical time complexity is linear with respect to the number of actuators and potential placements, which facilitates quick analysis in case of large structures.

Mobilization of Heavy Metals in Contaminated Soils induced by Bioaugmentation of Shewanella xiamenensis HM14

  • Walpola, Buddhi Charana;Arunakumara, K.K.I.U.;Song, Jun-Seob;Lee, Chan-Jung;Yoon, Min-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.4
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    • pp.290-298
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    • 2014
  • A bacterial strain with the potential ability to solubilize heavy metals was isolated from heavy metal contaminated soils collected from abandoned mines of Boryeong area in South Korea. The bacterial strain with the highest degree of metal resistance was shown to have close proximity with Shewanella xiamenensis FJ589031, according to 16S rRNA sequence analysis, and selected for investigating the mobilization of metals in soil or plant by the strain. The strain was found to be capable of solubilizing metals both in the absence and in the presence of metals (Co, Pb and Cd). Metal mobilization potential of the strain was assessed in a batch experiment and the results showed that inoculation could increase the concentrations of water soluble Co, Pb and Cd by 48, 34 and 20% respectively, compared with those of non-inoculated soils. Bacterial-assisted growth promotion and metal uptake in sunflower (Helianthus annuus) was evaluated in a pot experiment. In comparison with non-inoculated seedlings, the inoculation led to increase the growth of H. annuus by 24, 18 and 16% respectively in Co, Pb and Cd contaminated soils. Moreover, enhanced accumulation of Co, Pb and Cd in the shoot and root systems was observed in inoculated plants, where metal translocation from root to the above-ground tissues was also found to be enhanced by the strain. Plant growth promotion and metal mobilizing potential of the strain suggest that the strain could effectively be employed in enhancing phytoextraction of Co, Pb and Cd from contaminated soils.

Fatigue Damage Behavior in TIG Welded Joint of F82H Steel under Low Cycle Fatigue Loading (저주기 피로부하에서 F82H 강 TIG 용접 접합부의 피로손상거동)

  • Kim, Dong-Hyun;Park, Ki-Won
    • Journal of Welding and Joining
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    • v.33 no.6
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    • pp.42-48
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    • 2015
  • Reduced activation ferritic/martensitic steels are recognized as the primary candidate structural materials for fusion blanket systems. Welding is an inevitable for breeding blanket for pressure tightness and radioisotope confinement. Especially, TIG welding was chosen for sealing because it has the largest gap allowance compared to the other welding methods, and its properties are controllable by feed wire and welding conditions. In this study, the low cycle fatigue test using two-type gage such as extensometer and strain gage was applied to the TIG welded joint of F82H steel, for evaluating fatigue damage accumulation behavior of the HAZs. As the result, the over-tempered HAZ have shown a higher fatigue damage accumulation compared with other materials at all the testing conditions.

Baicalin Production in Transformed Hairy Root Clones of Scutellaria baicalensis

  • Hwang, Sung-Jin
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.2
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    • pp.105-109
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    • 2006
  • A transformed hairy root clone of Scutellaria baicalensis was established following infection with Agrobacterium rhizogenes ATCC15834. Three root clones of S baicalensis were selected by growth habit and baicalin content. The most active strain-the SR-03 clone-was examined for its growth and baicalin content under various culture conditions. The root growth and baicalin content were maximized in a Schenk and Hildebrandt medium supplemented with 4 and 6% sucrose, respectively. The accumulation of baicalin in transformed hairy roots was enhanced through exposure to various elicitors. Elicitation was attained by the addition of methyl jasmonate, salicylic acid, and various concentrations of fungal cell wall elicitors to the medium. The accumulation of baicalin in the elicited cultures ranged from 10.5 to 18.3 mg/g dry weight of the roots, which was 1.5- to 3-fold the amount attained in controls.

Characterizations of Disease Symptoms and Virus Replication Shown in the Interactions Between Arabidopsis (Arabidopsis ecotype에서 3종의 BCTV 분리주의 병증 및 복제 특성)

  • 박을용;박종범;이석찬
    • Korean Journal Plant Pathology
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    • v.14 no.5
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    • pp.507-512
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    • 1998
  • Molecular analysis has been done for characterization of the interactions between three beet curly top virus (BCTV) strains and two Arabidopsis ecotypes in terms of virus inducible disease symptoms and infectivities. The total DNA was isolated from three tissues (shoot tips, infection origins and roots) of virus infected plants and this DNA was analyzed by quantitatively and qualitatively to elucidate virus movement and symptom development. CTV-Worland infected Col-O and Sei-O showed only symptom shown in hypersusceptible ecotype Sei-O by BCTV-worland was shoot tip stunting. Kinetics of virus DNA accumulation of three different viruses indicated that roots contained more virus DNA than shoot tips or infection origins, and that disease symptom severity was strongly correlated with virus DNA accumulation. These results suggest that the mild and Worland-specific symptoms shown in Sei-O by BCTV-worland are caused by the interactions of host factors provided by hypersusceptible ecotype and viral factors of mild strain.

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Energy Status of Neurospora crassa Mutant nap in Relation to Accumulation of Carotenoids

  • Belozersk, Tatyana A.;Potapova, Tatyana V.;Isakova, Elena P.;Shurubor, Eugene I.;Savel'eva, Ludmila V.;Zvyagilskaya, Renata A.
    • Journal of Microbiology
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    • v.41 no.1
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    • pp.41-45
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    • 2003
  • N crassa mutant strain nap showed reduced growth rate, decreased electric membrane potential, and elevated intracellular ATP content in comparison to the wild type. Blue light induced a hyperpolarization of the membrane potential in both strains. The analysis of oxidative and phosphorylation activities of mitochondria isolated from the two strains has revealed that nap utilized more efficient oxidative pathways. The higher intracellular ATP content in the nap was presumably due to impaired transport systems of the plasma membrane, and to a lesser extent to the functioning of the fully competent respiratory chain. The excess ATP possibly accounts for carotenoid accumulation in the mutant.

Characterizations of Denitrifying Polyphosphate-accumulating Bacterium Paracoccus sp. Strain YKP-9

  • Lee, Han-Woong;Park, Yong-Keun
    • Journal of Microbiology and Biotechnology
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    • v.18 no.12
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    • pp.1958-1965
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    • 2008
  • A denitrifying polyphosphate-accumulating bacterium (YKP-9) was isolated from activated sludge of a 5-stage biological nutrient removal process with step feed system. This organism was a Gram-negative, coccus-shaped, facultative aerobic chemoorganotroph. It had a respiratory type of metabolism with oxygen, nitrate, and nitrite as terminal electron acceptors. The 16S rRNA gene sequence of strain YKP-9 was most similar to the 16S rRNA gene sequence of Paracoccus sp. OL18 (AY312056) (similarity level, 97%). Denitrifying polyphosphate accumulation by strain YKP-9 was examined under anaerobic-anoxic and anaerobic-oxic batch conditions. It was able to use external carbon sources for polyhydroxyalkanoates(PHA) synthesis and to release phosphate under anaerobic condition. It accumulated polyphosphate and grew a little on energy provided by external carbon sources under anoxic condition, but did neither accumulate polyphosphate nor grow in the absence of external carbon sources under anoxic condition. Cells with intracellular PHA cannot accumulate polyphosphate in the absence of external carbon sources under anoxic condition. Under oxic condition, it grew but could not accumulate polyphosphate with external carbon sources. Based on the results from this study, strain YKP-9 is a new-type denitrifying polyphosphate-accumulating bacterium that accumulates polyphosphate only under anoxic condition, with nitrate and nitrite as the electron acceptors in the presence of external carbon sources.

Numerical analysis of offshore monopile during repetitive lateral loading

  • Chong, Song-Hun;Shin, Ho-Sung;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • v.19 no.1
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    • pp.79-91
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    • 2019
  • Renewed interest in the long-term pile foundations has been driven by the increase in offshore wind turbine installation to generate renewable energy. A monopile subjected to repetitive loads experiences an evolution of displacements, pile rotation, and stress redistribution along the embedded portion of the pile. However, it is not fully understood how the embedded pile interacts with the surrounding soil elements based on different pile geometries. This study investigates the long-term soil response around offshore monopiles using finite element method. The semi-empirical numerical approach is adopted to account for the fundamental features of volumetric strain (terminal void ratio) and shear strain (shakedown and ratcheting), the strain accumulation rate, and stress obliquity. The model is tested with different strain boundary conditions and stress obliquity by relaxing four model parameters. The parametric study includes pile diameter, embedded length, and moment arm distance from the surface. Numerical results indicate that different pile geometries produce a distinct evolution of lateral displacement and stress. In particular, the repetitive lateral load increases the global lateral load resistance. Further analysis provides insight into the propagation of the shear localization from the pile tip to the ground surface.

Determination of the Fatigue Limit by Using a Tensile Testing Data (인장 실험 데이터를 이용한 피로한도 결정에 관한 연구)

  • Kim, Tae-Hun;Kim, Hak-Yun;O, Heung-Guk;Jin, Eok-Yong
    • Korean Journal of Materials Research
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    • v.10 no.2
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    • pp.155-159
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    • 2000
  • Microstructural processes during high cycle fatigue are investigated according to plastic-strain hardening, crack formation, crack propagation and fracture. It is shown that the fatigue test resembles the uniaxial tensile test. The logarithm of the number of cycles to failure is proportional to the elongation in the tensile test. Under high cycle fatigue test, the strain is normally elastic. If the strain is absolutly elastic, fatigue could not result. But this is over simplication. Nearly all metals undergo a minor amount of plastic strain even at low stress. Damage accumulation leadling to crack formation can continue in the persistent slip bands at very low average plastic strain amplitude. In the ten­s sile test the overall specimen follows the failure procedure whilst in the high cycle fatigue test the local persistent slip band follows the failure procedure. However accumulations of strain per unit volume in the deforming region before failure in both cases are equal locally.

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