• Title/Summary/Keyword: Curl

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Natural Occurrence of Tomato leaf curl New Delhi virus in Iranian Cucurbit Crops

  • Yazdani-Khameneh, Sara;Aboutorabi, Samaneh;Shoori, Majid;Aghazadeh, Azin;Jahanshahi, Parastoo;Golnaraghi, Alireza;Maleki, Mojdeh
    • The Plant Pathology Journal
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    • v.32 no.3
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    • pp.201-208
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    • 2016
  • The main areas for field-grown vegetable production in Iran were surveyed during the years of 2012-2014 to determine the occurrence of begomoviruses infecting these crops. A total of 787 leaf samples were collected from vegetables and some other host plants showing virus-like symptoms and tested by an enzymelinked immunosorbent assay (ELISA) using polyclonal antibodies produced against Tomato yellow leaf curl virus (TYLCV). According to the ELISA results, 81 samples (10.3%) positively reacted with the virus antibodies. Begomovirus infections were confirmed by polymerase chain reaction (PCR) using previously described TYLCV-specific primer pair TYLCV-Sar/TYLCV-Isr or universal primer pair Begomo-F/Begomo-R. The PCR tests using the primer pair TYLCV-Sar/TYLCV-Isr resulted in the amplification of the expected fragments of ca. 0.67-kb in size for ELISA-positive samples tested from alfalfa, pepper, spinach and tomato plants, confirming the presence of TYLCV. For one melon sample, having a week reaction in ELISA and no reaction in PCR using TYLCV-specific primers, the PCR reaction using the primer pair Begomo-F/Begomo-R resulted in the amplification fragments of the expected size of ca. 2.8 kb. The nucleotide sequences of the DNA amplicons derived from the isolate, Kz-Me198, were determined and compared with other sequences available in GenBank. BLASTN analysis confirmed the begomovirus infection of the sample and showed 99% identities with Tomato leaf curl New Delhi virus (ToLCNDV); phylogenetic analysis supported the results of the database searches. This study reports the natural occurrence of TYLCV in different hosts in Iran. Our results also reveal the emergence of ToLCNDV in Iranian cucurbit crops.

Simulation of East Sea Circulation in a Laboratory Experiment of Rotating Cylindrical Container (동해 해수순화 모의를 위한 회전반 실험)

  • 나정열;최진영
    • 한국해양학회지
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    • v.30 no.1
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    • pp.57-63
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    • 1995
  • Two-layered fluid with sloping bottom and top(${\beta}$-effect) in rigid cylinder is put on the rotating table. To drive the lower-layer motion in "the Sverdrup type" flow external fluid is pumped into the lower-layer. By introducing inlet-outlet system in the upper-layer, an analogy to the Tsushima Tsugaru, Soya of the East Sea has been tested. The position of the inlet-outlet system and the difference between the strength of inlet or outlet flow are changed to see the effects of the wind stress on the upper-layer. The northern part of inflow toward the outlet may be interpreted roughly as the position of the polar front in the East Sea. Experimental observations have revealed that the inflow flows along the western boundary before it separates into the interior and flows straight toward the outlet position. However, the wind effect is imposed upon the upper-layer, the western boundary flow branches into two parts of which one flows along the boundary and the other flows into the interior under the influence of negative wind stress curl, while southward western boundary flow seems to block the flow and deflect it to the interior. The changes in the position of inlet-outlet system produce more significant changes in flow pattern in that cyclonic flow in the north controls the northern extent of the polar front by deflecting the northward interior motion toward the west(outlet). Interface displacement which depends strongly on the velocity difference between two layers seems to play crucial role in terms of the path of upper-layer flow, particularity, the inflow.

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A study on material selection for semiconductor die parts and on their modification and manufacture (반도체금형에서 부속부품의 재료선정 및 개선과 제작에 관한 연구)

  • Kim, Sei-hwan;Choi, Kye-kwang
    • Design & Manufacturing
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    • v.8 no.1
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    • pp.27-30
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    • 2014
  • Alloy tool steel such as SKD11 and SKD61 or high speed tool like SKH51 are used as materials for semiconductor dies. Cavities, curl blocks, pot blocks and housings are made from those materials. To make those parts from alloy tool steel or high speed tool, one utilizes discharge machining, and mechanical machining including machining center, milling, drilling, forming grinding and others. In the process of cutting machining and polishing, the die materials become unsuitable for machining owing to bubbles and foreign substances in them, which hinders production process. Therefore, this study focuses on die material selection criteria, and on analysis and comparison of material characteristics to help companies to solve their problems, make die manufacture less burdensome and extend die life.

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Analysis of Residual Stress and Etching Curl of Cold Rolled Sheet in Shadow Mask (Shadow Mask용 냉간 압연박판의 잔류응력과 변형 해석)

  • 정호승;조종래;문영훈;김교성
    • Transactions of Materials Processing
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    • v.12 no.2
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    • pp.123-127
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    • 2003
  • The cold rolling conditions for the ultra thin steel for tension mask are very important because the residual stress that affects the flatness of strip is generate during the cold rolling. The residual stress in the sheet causes etching curls when it suffers perforation process. The residual stress through the thickness. To estimate the residual stress and deformation due to etching curl. FEM analysis is performed. Numerical simulation employ a ANSY5 5.6 and an elastic-plastic constitutive equation. The simulation results indicate the distribution of residual stress in the rolled sheet can be controlled by selecting the rolling conditions properly.

The Prediction of Chip Flow Angle on chip Breaker Shape Parameters (칩브레이커 형상변수에 의한 칩유동각 예측)

  • 박승근
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.2
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    • pp.96-101
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    • 2000
  • In machining with cutting tool inserts having complex chip groove shape the flow curl and breaking pattern of the chip are different than in flat-face inserts. In the present work an effort is made to understand the three basic phe-nomena occurring in a chip since its formation in machining with groove type and pattern type inserts. These are the ini-tial chip flow the subsequent development of up and side curl and the final chip breaking due to the development of tor-sional and bending stresses. in this paper chip flow angle in a groove type and pattern type inserts. The expres-sion for chip flow angle in groove type and pattern type inserts is also verified experimentally using high speed filming techniques.

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Effect of Curling on the Characteristics of Pulp Fibers (컬화가 펄프 섬유의 특성에 미치는 영향)

  • 원종명;이재훈;한창석
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.1
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    • pp.45-52
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    • 2001
  • Recycling of wastepaper is very important for the environmental protection. However inferior strength and slower drainage characteristic that are brought by the hornification and the increase of fines respectively limited the increase of wastepaper recycling. The purpose of this study is to obtain some fundamental information that is helpful to develop the technologies which can improve the characteristics of recycled fibers. Softwood bleached kraft pulp was curlated with Hobart mixer at several different consistency. The curlation of fibers can cause the internal fibrillation and decreasing the crystallinity without serious damage of fiber surface. Curl index, kink index, freeness and WRV were increased, but crystallinity was decreased with the increase of curlation consistency.

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Modeling of Turbulent Molecular Mixing by the PDF Balance Method for Turbulent Reactive Flows (난류연소 유동장에서의 확률밀도함수 전달방정식을 이용한 난류혼합 모델링)

  • Moon, Hee-Jang
    • Journal of the Korean Society of Combustion
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    • v.2 no.1
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    • pp.39-51
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    • 1997
  • A review of probability density function(PDF) methodology and direct numerical simulation for the purpose of modeling turbulent combustion are presented in this study where particular attention is focused on the modeling problem of turbulent molecular mixing term appearing in PDF transport equation. Existing mixing models results were compared to those evaluated by direct numerical simulation in a turbulent premixed medium with finite rate chemistry in which the initial scalar field is composed of pockets of partially burnt gases to simulate autoignition. Two traditional mixing models, the least mean square estimations(LMSE) and Curl#s model are examined to see their prediction capability as well as their modeling approach. Test calculations report that the stochastically based Curl#s approach, though qualitatively demonstrates some unphysical behaviors, predicts scalar evolutions which are found to be in good agreement with statistical data of direct numerical simulation.

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The Prediction of Chip Flow Angle on Chip Breaker Shape Parameters (칩브레이커 형상변수에 의한 칩유동각 예측)

  • 박승근
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.381-386
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    • 1999
  • In machining with cutting tool inserts having complex chip groove shape, the flow, curl and breaking patterns of the chip are different than in flat-face type inserts. In the present work, an effort is made to understand the three basic phenomena occurring in a chip since its formation in machining with groove type and pattern type inserts. These are the initial chip flow, the subsequent development of up and side curl and the final chip breaking due to the development of torsional and banding stresses. In this paper, chip flow angle in a groove type and pattern type inserts. The expression for chip flow angle in groove type and pattern type insets is also verified experimentally using high speed filming techniques.

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Finite Element Springback Analysis of Vertically-Walled Auto-Body Part (수직벽을 가진 자동차 부품 성형공정의 스프링백 유한요소 해석)

  • 이두환;윤치상;신철수;조원석;구본영;금영탁
    • Transactions of Materials Processing
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    • v.9 no.6
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    • pp.574-581
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    • 2000
  • A vertically-walled auto-body part is one of the most difficult stamping parts because of angle change, wall curl, and twisting of the blank after springback as well as fracture and wrinkle. In this study, computational simulations of the vertically-walled auto-body part are carried out focusing on angle change, wall curl, and twisting after springback. Binderwrap blank shape is used in forming analysis for precise initial contacts between punch and blank. An adaptive mesh method is used in springback analysis for precise calculation of bending moments. In springback analysis, the differences of 2 and 3 dimensional analysis are compared and the effects of blank holdig force and friction coefficient are evaluated. In order to verify the validity of simulation results, they are compared with measured ones. The predicted thickness distribution and formed shape are agreed well with those of the measurement. The Predicted springback amount is less than that of the measurement.

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Analysis of Deformation and Residual Curvature of Steel Sheets in Strip Process Lines (박강판 제조공정에서의 소재 굽힘변형과 잔류만곡 발생 해석)

  • 박기철;전영우;정기조
    • Transactions of Materials Processing
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    • v.6 no.2
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    • pp.118-135
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    • 1997
  • In order to analyze the deformation and residual curvature of steel sheets in the strip processing lines, a program for calculating curvature and work hardening of sheet was developed. Strip deformation caused by repeated bending under tension in the process lines was analyzed on the basis of the incremental-plasticity theory with the mixed hardenting model for the purpose of predicting the strip shape and the yield stress change. The developed calculation program was applied to predict curl and gutter of sheets within a 10% difference. The yield stress increment was also predicted with the similar accuracy. Application of the model to tension legvelling process showed that gutter could be controlled by intermesh and elongation. The yield stress increment in the electro-galvanizing line calculated by the developed program was found to be dependent on the yield strength, the applied tension and the diameter of the smallest roll.

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