• Title/Summary/Keyword: Strength decrease

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Changes in Photosynthesis and Carbohydrate Reserves of 'Fuji'/M9 Apple trees in Response to Early Defoliation at Growing Period (생육기 조기낙엽에 따른 사과 '후지'/M9의 광합성과 탄수화물의 변화)

  • Jeong, Jae Hoon;Han, Jeom Hwa;Ryu, Suhyun;Han, Hyun Hee;Kwon, YongHee;Do, Gyung-Ran;Yim, Sun-Hee;Lee, Han-Chan
    • Journal of Bio-Environment Control
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    • v.26 no.4
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    • pp.291-296
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    • 2017
  • This study was conducted to evaluate the influence of early defoliation on photosynthesis and carbohydrate reserves when the source leaves of 'Fuji'/M9 apple (Malus domestica Borkh.) trees were removed during the growing period. Bud regrowth rates of 80%, 50% defoliation and non-defoliation treatments were significantly different 82.7%, 45.9% and 2.1% respectively at 30 days after treatment. In all treatments, sucrose and starch concentrations in remaining leaves decreased non-significantly during the 14-day period. No significant changes were observed for total soluble carbohydrates in non-defoliation and 50% defoliation. However, in 80% defoliated treatments, concentrations of sorbitol and total soluble carbohydrates in remaining leaves declined steadily during the 14-day period. It is thought that high sink strength increases the requirements of carbohydrate from remaining leaves more than non-defoliated. The concentrations of starch in the roots tend to decrease non-significantly as percentage of defoliation increased. Photosynthesis of remaining leaves was monitored during the 14-day period after partial defoliation treatments. Net photosynthetic rates (Pn) and stomatal conductance were significantly enhanced in the 80% defoliation. The observed photosynthetic enhancement following partial defoliation may have been due to the enhancement of osmotic potential in leaves. These results were estimated that increasing of photosynthetic rate in the partial defoliation is due to the sink carbohydrate requirements for the current year's secondary growth of buds.

Expression of the Floral Repressor miRNA156 is Positively Regulated by the AGAMOUS-like Proteins AGL15 and AGL18

  • Serivichyaswat, Phanu;Ryu, Hak-Seung;Kim, Wanhui;Kim, Soonkap;Chung, Kyung Sook;Kim, Jae Joon;Ahn, Ji Hoon
    • Molecules and Cells
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    • v.38 no.3
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    • pp.259-266
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    • 2015
  • The regulation of flowering time has crucial implications for plant fitness. MicroRNA156 (miR156) represses the floral transition in Arabidopsis thaliana, but the mechanisms regulating its transcription remain unclear. Here, we show that two AGAMOUS-like proteins, AGL15 and AGL18, act as positive regulators of the expression of MIR156. Small RNA northern blot analysis revealed a significant decrease in the levels of mature miR156 in agl15 agl18 double mutants, but not in the single mutants, suggesting that AGL15 and AGL18 co-regulate miR156 expression. Histochemical analysis further indicated that the double mutants showed a reduction in MIR156 promoter strength. The double mutants also showed reduced abundance of pri-miR156a and pri-miR156c, two of the primary transcripts from MIR156 genes. Electrophoretic mobility shift assays demonstrated that AGL15 directly associated with the CArG motifs in the MIR156a/c promoters. AGL18 did not show binding affinity to the CArG motifs, but pull-down and yeast two-hybrid assays showed that AGL18 forms a heterodimer with AGL15. GFP reporter assays and bimolecular fluorescence complementation (BiFC) showed that AGL15 and AGL18 co-localize in the nucleus and confirmed their in vivo interaction. Overexpression of miR156 did not affect the levels of AGL15 and AGL18 transcripts. Taking these data together, we present a model for the transcriptional regulation of MIR156. In this model, AGL15 and AGL18 may form a complex along with other proteins, and bind to the CArG motifs of the promoters of MIR156 to activate the MIR156 expression.

Bearing resistance design of stainless steel bolted connections at ambient and elevated temperatures

  • Cai, Yancheng;Young, Ben
    • Steel and Composite Structures
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    • v.29 no.2
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    • pp.273-286
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    • 2018
  • In recent years, significant progress has been made in developing design rules for stainless steel members, while the investigation on bolted connections is relatively limited, in particular at elevated temperatures. In this paper, experimental and numerical investigations on stainless steel bolted connections at ambient and elevated temperatures from the literature were reviewed. Firstly, the research program that focused on structural behavior of cold-formed stainless steel (CFSS) bolted connections at elevated temperatures carried out by the authors were summarized. Over 400 CFSS single shear and double shear bolted connection specimens were tested. The tests were conducted in the temperature ranged from 22 to $950^{\circ}C$ using both steady state and transient state test methods. It is shown that the connection strengths decrease as the temperature increases in the similar manner for the steady state test results and the transient state test results. Generally, the deterioration of the connection strengths showed a similar tendency of reduction to those of the material properties for the same type of stainless steel regardless of different connection types and different configurations. It is also found that the austenitic stainless steel EN 1.4571 generally has better resistance than the stainless steel EN 1.4301 and EN 1.4162 for bolted connections at elevated temperatures. Secondly, extensive parametric studies that included 450 specimens were performed using the verified finite element models. Based on both the experimental and numerical results, bearing factors are proposed for bearing resistances of CFSS single shear and double shear bolted connections that subjected to bearing failure in the temperature ranged from 22 to $950^{\circ}C$. The bearing resistances of bolted connections obtained from the tests and numerical analyses were compared with the nominal strengths calculated from the current international stainless steel specifications, and also compared with the predicted strengths calculated using the proposed design equations. It is shown that the proposed design equations are generally more accurate and reliable than the current design rules in predicting the bearing resistances of CFSS (EN 1.4301, EN 1.4571 and EN 1.4162) bolted connections at elevated temperatures. Lastly, the proposed design rules were further assessed by the available 58 results of stainless steel bolted connections subjected to bearing failure in the literature. It is found that the proposed design rules are also applicable to the bearing resistance design of other stainless steel grades, including austenitic stainless steel (EN 1.4306), ferritic stainless steel (EN 1.4016) and duplex stainless steel (EN 1.4462).

A study on unmanned watch system using ubiquitous sensor network technology (유비쿼터스 센서 네트워크 기술을 활용한 무인감시체계 연구)

  • Wee, Kyoum-Bok
    • Journal of National Security and Military Science
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    • s.7
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    • pp.271-303
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    • 2009
  • "Ubiquitous sensor network" definition is this-Someone attaches electro-magnetic tag everything which needs communication between man to man, man to material and material to material(Ubiquitous). By using attached every electro-magnetic tag, someone detects it's native information as well as environmental information such as temperature, humidity, pollution and infiltration information(Sensor). someone connects it realtime network and manage generated information(Network). 21st century's war is joint combined operation connecting with ground, sea and air smoothly in digitalized war field, and is systematic war provided realtime information from sensor to shooter. So, it needs dramatic development on watch reconnaissance, command and control, pinpoint strike etc. Ubiquitous computing and network technologies are essential in national defense to operate 21st century style war. It is possible to use many parts such as USN combined smart dust and sensor network to protect friend unit as well as to watch enemy's deep area by unmanned reconnaissance, wearable computer upgrading soldier's operational ability and combat power dramatically, RFID which can be used material management as well as on time support. Especially, unmanned watch system using USN is core part to transit network centric military service and to get national defense efficiency which overcome the dilemma of national defense person resource reducing, and upgrade guard quality level, and improve combat power by normalizing guardian's bio rhythm. According to the test result of sensor network unmanned watch system, it needs more effort and time to stabilize because of low USN technology maturity and using maturity. In the future, USN unmanned watch system project must be decided the application scope such as application area and starting point by evaluating technology maturity and using maturity. And when you decide application scope, you must consider not only short period goal as cost reduction, soldier decrease and guard power upgrade but also long period goal as advanced defense ability strength. You must build basic infra in advance such as light cable network, frequency allocation and power facility etc. First of all, it must get budget guarantee and driving force for USN unmanned watch system project related to defense policy. You must forwarded the USN project assuming posses of operation skill as procedure, system, standard, training in advance. Operational skill posses is come from step by step application strategy such as test phase, introduction phase, spread phase, stabilization phase and also repeated test application taking example project.

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Basic study of new concept environment-friendly pile foundations with earthquake resistant foundation and lateral reinforcement on rapid-transit railway bridge (고속철도교 기초 내진 및 수평저항성능 보강형 신개념 친환경말뚝 신공법의 실용화 기초연구)

  • SaGong, Myung;Paik, Kyu-Ho;Lim, Hae-Sik;Cho, Kook-Hwan;Na, Kyung
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.880-894
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    • 2010
  • The Grout injected precast pile is widely used in rapid-transit railway bridge recently. The existing portland cement of well used filling at injected precast method that with low strength and environmental pollution, unstable in which ground water contamination by cement flow out, ground relaxation by water down, decrease of horizontality resistance and durability and load transfer divide etc. In particular, as in rapid-transit railway bridge need to secure safety from different angle with vibration of high speed train, horizontal force when train stop and earthquake. Works of foundation construction consider to requirements of the times to coal yard green growth. Together, new green foundation method for possible economics and securing of reduce the term of works are material to developments. Therefore, we carried out study that it is using and development new concept environment - friendly filling include durability and earthquake resistance, for secure safety and minimize environment pollution. To achieve this, we carried out difference tests that new green fillings of underwater concrete, high liquidity, high viscosity, early stiffness as compared to existing portland cement fillings. As results, new green filling have outstanding application at precast pile method and micropile construction method with vertical bearing capacity, horizontal bearing capacity and many case. From now on we will be looking forward to development of new environment-friendly foundation method from various further studies.

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Life Time Prediction and Physical Properties of Chloroprene Rubber Aged by Seawater (클로로프렌 고무의 해수에 의한 물성 변화 및 노화 수명 예측)

  • Lee, Chan Koo;Yun, Ju Ho;Kim, Il;Shim, Sang Eun
    • Elastomers and Composites
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    • v.47 no.1
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    • pp.9-17
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    • 2012
  • Herein, life time prediction based on the deterioration of physical properties of chloroprene rubber (CR)aged by heat and seawater was performed. CR samples were experienced an accelerated test at $80^{\circ}C$, $100^{\circ}C$, $120^{\circ}C$ for heat aging, and $40^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$ for seawater aging for 20,000 hrs. The change in tensile strength, maximum elongation,hardness was measured. As a result, the decrease in elongation was a major factor causing failure. The life time estimated using an Arrhenius model was 125 years at $23^{\circ}C$ for thermal aging and 9 years at $23^{\circ}C$ for seawater aging. SEM and elemental analysis reveal that cracks were generated and the content of oxygen was increased for CR agined by seawater. FT-IR spectrum shows the new C-O and C = O bonds were generated by the chemical reaction with seawater. Also, the glass transtion temperature was increased and the thermal decomposition was decreased by seawater aging.

Synthesis of High-energy-density Fuel through Dimerization of Bicyclo[2.2.1]hepta-2,5-diene over Co/HY Catalyst (Co/HY 제올라이트 촉매상에서 Bicyclo[2.2.1]hepta-2,5-diene 이량화를 통한 고에너지밀도 연료 제조)

  • Kim, Jongjin;Shim, Beomseok;Lee, Gayoung;Han, Jeongsik;Jeon, Jong-Ki
    • Applied Chemistry for Engineering
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    • v.29 no.2
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    • pp.185-190
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    • 2018
  • The dimer of bicyclo [2.2.1] hepta-2,5-diene (norbornadiene) can be used as a high-energy-density fuel. The purpose of this study is to investigate the effect of Co loading on the acid properties of HY zeolite catalyst and the catalytic activity in norbornadiene dimerization. When the cobalt was loaded on the HY zeolite catalyst, the amount of acid sites did not change, but the acid strength weakened. This can be attributed to the decrease in $Br{\ddot{o}}nsted$ acid site and the increase in Lewis acid site. The norbornadiene conversion and yield of norbornadiene dimer over the Co/HY catalyst showed higher than those over the HY zeolite catalyst. The higher activity of the Co/HY catalyst can be ascribed to the higher amount of Lewis acid sites over the Co/HY catalyst. Density and calorific values of the norbornadiene dimer prepared by using the Co/HY catalyst agreed well with the known values in the literature. It was confirmed that the norbornadiene dimer prepared in this study can be used as a high-energy-density fuel.

Analysis of Deformation and Stability of Slope at the Wiri Region of Local Road 999 Nearby Andong, Gyeongsangbukdo in Korea. (999번 지방도로 경상북도 안동시 위리 지역의 사면 변형 및 안정성 분석)

  • 장현식;장보안
    • The Journal of Engineering Geology
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    • v.10 no.1
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    • pp.1-12
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    • 2000
  • Heaving of road and subsidence of slope took place at the Wiri region of the local highway 999 in Gyeongsangbukdo, Korea after heavy rain in the next year of construction. Although the state government had performed remedial treatments by reducing the angle and the height of the slope, deformation had never stopped. Therefore, we have preformed the analysis of deformation and stabilityof the slope. Study area consists of the Cretaceous shale, siltstone and sandstone and two faults are found. The major deformation occurred by sliding of rock mass along faults after heavy rain because not only thepore pressure at the fault plane and the unit weight of sliding mass increased, but did the shearstrength of saturated fault clay become very low. The decrease in shear strength of saturated fault clayis the major factor among the reasons for deformation. Numerical simulations using limit equilibriummodel, finite difference model and finite element model were performed for eight cross sections.Although safety factors are above 1.7 during the dry season, they become below 1.0 when groundwaterlevel raises to surface. The maximum displacement is about 15-3Ocm. However, safety factors increasedto above 2.4 and the maximum displacement is below 2.08cm after remedial treatment, Indicating thatthe slope becomes stable.

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Influence of Dietary Germanium Biotite on Egg Quality and Fecal Noxious Gas Content in Laying Hens (산란계 사료에 게르마늄 흑운모의 첨가가 난각특성 및 분내 유해가스 함량에 미치는 영향)

  • 이원백;김인호;홍종욱;권오석;이상환;민병준;정연권
    • Korean Journal of Poultry Science
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    • v.30 no.1
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    • pp.61-66
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    • 2003
  • This study was conducted to investigate the effects of dietary germanium biotite supplementation on egg quality and fecal noxious gas content in laying hens. One hundred and forty-four 40-wk-old, ISA Brown layers were used in this experiment. Dietary treatments were 1) CON(control diet), 2) GB0.5(control diet + 0.5% germanium biotite), 3) GB1.0 (control diet + 1.0% germanium biotite) and 4) GB1.5(control diet + 1.5% germanium biotite). Hen-day egg Production and egg shell breaking strength were not influenced by germanium biotite supplementation. However, egg weight decrease as the level of germanium biotite supplementation increased in the diets increased(Cubic effect, p<0.02). Eggshell thickness, yolk color and yolk index were not influenced by garmanium biotite supplementation. Serum triglyceride concentration as dietary germanium biotite increased (linear effect P<0.02; quadratic effect, p<0.05). Dietary supplementation of germanium biotite reduced fecal NH$_3$-N concentration (P<0.01), propionic acid(P<0.01), butyric acid( P<0.05) and acetic aicd(P<0.01) concentrations in the feces. In conclusion, the results of this experiment indicated that dietary germanium biotite supplementation did not affect egg shell quality, but reduced fecal NH$_3$-N concentration.

Effects of Dietary Phytase on Performance, Egg Quality, Excretion of N and P, and Ileal Digestibility in Laying Hens (Phytase 첨가가 산란계의 생산성, 난질, 질소와 인의 배설량 및 회장 소화율에 미치는 영향)

  • HwangBo, J.;Ahn, J.H.;Chung, W.T.;Ohh, S.J.;Lee, H.J.;Kim, H.K.;Lee, S.U.;Hong, E.C.
    • Korean Journal of Poultry Science
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    • v.34 no.2
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    • pp.119-128
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    • 2007
  • The effects of microbial phytase on laying performance, egg quality, and ileal digestibility of nutrients and amino acids were examined at three levels of phytase (0, 300, 600 unit/kg) in 55-wk-old White Leghorn for 4 weeks. Egg productivity tended to increase with supplemental phytase compared to that of control. Daily feed intake of hens fed phytase also increased. Egg shell thickness was not significantly different among the treatments. Haugh unit and yolk color were not statistically different. However, egg shell breaking strength was high at phytase treatment. Excretion and absorption of nitrogen were no difference among all treatments, but those of phosphorus was higher in the phytase treatment than control. The digestibility was high at crude fiber, crude ash, calcium and phosphorus in nutrients, at lysine, methionine and phenylalanine in essential amino acids, and alanine, cystine, glutamic acid, glycine and tyrosine in non-essential amino acids. In conclusion, supplemental microbial phytase in laying hens diet may help to improve egg production and to decrease P of feces. But, further studies were needed to investigate on the digestibility.