• Title/Summary/Keyword: 전기IT

Search Result 23,855, Processing Time 0.049 seconds

Comparison of Life Table and Feeding Behavior of Resistance and Susceptible Population of the Green Peach Aphid, Myzus persicae (Hemiptera: Aphididae) against Etofenprox (Etofenprox에 대한 복숭아혹진딧물(Myzus persicae)의 저항성과 감수성 개체군의 생명표와 섭식행동 비교)

  • Jo, Chang-Wook;Park, Cho-Rong;Yoon, Kyu-Sik;Kang, Min-A;Kwon, Hae-Ri;Kang, Eun-Jin;Seo, Mi-Ja;Yu, Yong-Man;Youn, Young-Nam
    • Korean journal of applied entomology
    • /
    • v.48 no.3
    • /
    • pp.301-310
    • /
    • 2009
  • For the comparing of mortality of the resistance and susceptible population of Myzus persicae, etofenprox was treated in the recommended concentration of 200ppm. Mortalities of resistance population were 16.7 and 36.7%, and susceptible population were 86.7 and 86.7% after 24 and 48 hours treatment, respectively. For the detect of cross resistance to other pyrethroids, 6 pyrethroids were examined. Mortalities of susceptible and resistance populations were 90 and 31% to deltamethrin, 92 and 23% to lambda cyhalothrin, 81 and 14% to cypermethrin, 70 and 20% to $\alpha$-cypermethrin, 29 and 28% to fenpropathrin, 84 and 29% to fenvalerate, respectively. It was showed that resistance populations were generally resistive to other pyrethroids. On the other hands, for recognized ecological characteristic of M. persicae susceptible and resistance populations life table was tested on the pepper leaves in the petri dish and on the plant in the pot. This results were showed that intrinsic rate of increase ($r_m$), net reproduction number ($R_0$) and generation time in day ($T_c$) were significantly different between two population in both tested. However, life span and reproduction period were slightly different between them. Otherwise, feeding behaviors were tested using EPG technique with non- and treated etofenprox. First potential drop time of susceptible and resistance population was 73.5 and 257.9 sec with non-treated and 93.3 and 1076.2 sec after treated, respectively. Electrical probing signals were 8.2 and 48.8 times with susceptible and resistance individuals after treated etofenprox, respectively. It was supposed that the resistance is more probings than susceptible population. After treated, total feeding time have more 6,728.9 sec on resistance than 965.5 sec on susceptible population. So, total non penetration time of susceptible population was 3,000 sec longer than resistance population.

An Analysis of the Port Competition Structure: Focusing on Import and Export Items of Ports in Western Coast Region (항만의 경쟁구조 분석에 관한 연구: 서해안권 항만 수출입품목을 중심으로)

  • Lee, Jin-Kyu;Yeo, Gi-Tae
    • Journal of Korea Port Economic Association
    • /
    • v.31 no.4
    • /
    • pp.75-89
    • /
    • 2015
  • This study examines 31 import and export cargo items handled in each port to investigate which items face the most competition among the ports and how many of them are transited to other ports. The study aims to suggest implications for the future port policy of Incheon Port. It was found that the volume concentration in the Western Coast region from 2005 to 2014 became increasingly decentralized. The decentralization began in earnest in 2009 in particular, and the value was 0.448 in 2014, indicating fierce competition among the regions. According to the static and dynamic positioning analyses results for Incheon Port, Pyeongtaek and Dangjin Port, and Gunsan Port, using BCG Matrix, the static positioning analysis showed that Incheon Port belongs to the 3rd quadrant (Cash Cows), Pyeongtaek and Dangjin Port belongs to the 2nd quadrant (Question Marks), and Gunsan Port belongs to the (Dogs) group. This implies that Incheon Port has maintained its position with large shares compared to those of other ports, despite its low growth rate. However, the market position and growth rate of Incheon Port decreased according to the dynamic positioning analysis results. The shift-share analysis results indicated that the volumes of Incheon Port and Gunsan Port were shifting to Pyeongtaek and Dangjin Port. Moreover, the ratio of absolute growth to potential growth of Incheon Port and Gunsan Port turned out to be significantly lower than that of Pyeongtaek and Dangjin Port, implying that Incheon Port and Gunsan Port are declining as compared to Pyeongtaek Port and Dangjin Port. According to the LQ index analysis results, specialized items from Incheon Port that do not overlap with other ports included the following ten items: meat, fish and crustaceans, bituminous coals, crude oil and petroleum, petroleum-refined products, plastic rubber and products, textiles, nonferrous metal and products, electric machinery, and aircrafts and ships. In particular, it was confirmed that the bulk cargo of Incheon Port was actually shifting to Pyeongtaek and Dangjin Port following the policy of re-establishing port functions.

Effect of seeding date on growth , dry matter accumulation and chemical composition of sorghum , sudangrass and sorghum-sudangrass Hybrid (파종기 이동이 수수 , 수단그라스 및 수수$\times$수단그라스 교잡종의 생육 , 건물축적 및 성분 함량에 미치는 영향)

  • 한흥전;안수봉
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.5 no.1
    • /
    • pp.62-72
    • /
    • 1985
  • In order to find out the effects of seeding time on growth, dry matter production and nutritive content of Pioneer 931, Pioneer 988 and Piper, this study was carried out on the experimental field of Livestock Experiment Station in 1981-83. Seeding time were 7 with 14-day interval from April 16 to July 9. The results are summarized as follows: 1. It tool about 12 to 13 days from seeding to emergence in case of Mid-April seeding and 7 to 8 days in Late-June. Earlier seeding, more longer growth period from emergence to heading they required. 2. Plant height of Pioneer 931 seeded lately was longer than 4.5 meters in primary growth and Sudangrass was about 2.0 to 2.5 meters. Leaf area was the greatest in Mid-August by early seeding but it was increased until Early-October by late seeding. 3. Sorghum gas brought the highest yield in dry mater and Sudangrass the lowest. In general dry matter yield reduced gradually in response to later seeding but Pioneer 931 has brought more than 10 tons per hecter until Late-June. 4. Relative Growth Rate, Leaf Area Ratio and Leaf Weight of all varieties decreased in accordance with growth development. 5. Crude protein content of leaf was higher than stem and the younger the plants, the more protein they contain. Nitrogen Free Extract was just opposite to crude protein.

  • PDF

Optimum Dissolved Oxygen Level for the Growth of Tilapia in the Recirculating Water System (순환여과식사육장치에서 틸라피아의 성장을 위한 최적용존산소량)

  • KIM In-Bae;WOO Young-Bae
    • Journal of Aquaculture
    • /
    • v.1 no.1
    • /
    • pp.67-73
    • /
    • 1988
  • A growth experiment of tilapia (offsprings of the hybrid between Oreochromis niloticus and O. mossambicus) under different dissolved oxygen levels in the recirculating water system was conducted at the Fish Culture Experiment Station of the National Fisheries University of Pusan from February 4 to March 5, 1986. Six tanks with a capacity of $1.8m^3$ of water each were used under the same condition of water parameters except for dissolved oxygen levels which were designated to maintain at 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mg/$\iota$. Each tank was stocked with 90 kg of fish each averaging 64 to 69 grams. The average water temperature during the course of the experiment was $22.5^{\circ}C$. The results obtained are summarized as follows: The food conversion efficiencies were very good, being 1.05-1.11 at 3.5, 3.0, 2.5 and 2.0 mg/$\iota$ DO levels without any significant differences among them, but at 4.0 mg/$\iota$ the F. C. was 1.39 and at 1.5 mg/$\iota$ it was 1.61 being very poor compared with the others. The daily growth rate performance was best at 3.5 mg/$\iota$ dissolved oxygen level followed by 3.0 and 2.5 mg/$\iota$ with slight differences while at 4.0 and 2.0 mg/$\iota$ DO levels the growths were significantly poor, and at 1.5 mg/$\iota$ DO level it was extremely poor. In 1.5 mg/$\iota$ group, the fish did not accept feed vigorously and after feeding the fish usually concentrated around the inflow point showing oxygen deficiency response. While at 4.0 mg/$\iota$ high feeding rates tended to waste significant amounts of feed while eating and led to water deterioration, and above these levels the results is considered to lead to a waste of energy with uneconomical performance. On the other hand, at and below 2.0 mg/$\iota$ DO level the tilapia certainly showed a poor growth performance. The experiment indicates that the DO range of 2.5$\~$3.5 mg/$\iota$ is the optimum level for the good growth performance.

  • PDF

Properties of stretch-activated $K^+$ channels in an G292 osteoblast-like cell (G292 세포에서 세포막 신장으로 활성화되는 $K^+$통로의 특성)

  • Lee, Sang-Gook;Jung, Dong-Keun;Suh, Duk-Joon;Park, Soo-Byung
    • The korean journal of orthodontics
    • /
    • v.30 no.2 s.79
    • /
    • pp.197-204
    • /
    • 2000
  • [$K^+$]-selective ion channels were studied in excised inside-out membrane patches from human osteoblast-like cells (G292). Three classes of $K^+$channels were present and could be distinguished on the basis of conductance. Conductances were $270\pm27\;pS,\;113\pm12\;pS,\;48\pm8\;pS$ according to their approximate conductances in symmetrical 140 mM KCl saline at holding potential of -80 mV It was found that the small conductance (48 pS) $K^+$channel activation was dependent on membrane voltage. In current-voltage relationship, small conductance $K^+$channel showed outward rectification, and it was activated by the positive potential inside the membrane. In recordings, single channel currents were activayed by a negative pressure outside the membrane. The membrane pressure increased $P_{open}$ of the $K^+$ channel in a pressure-dependent manner. In the excised-patch clamp recordings, G292 osteoblast-like cells have been shown to contain three types of $K^+$ channels. Only the small conductance (48 pS) $K^+$channel is sensitive to the membrane stretch. These findings suggest that a hyperpolarizing current, mediated in part by this channel, may be associated with early events during the mechanical loading of the osteoblast. In G292 osteoblast-like cells, $K^+$channel is sensitive to membrane tension, and may represent a unique adaptation of the bone cell membrane to mechanical stress.

  • PDF

Effects of heat treatment on the load-deflection properties of nickel-titanium wire (니켈-티타늄 와이어의 열처리에 따른 부하-변위 특성 변화)

  • Chang, Soo-Ho;Kim, Kwang-Won;Lim, Sung-Hoon
    • The korean journal of orthodontics
    • /
    • v.36 no.5
    • /
    • pp.349-359
    • /
    • 2006
  • Objective: Nickel-titanium alloy wire possesses excellent spring-back properties, shape memory and super-elasticity. In order to adapt this wire to clinical use, it is necessary to bend as well as to control its super-elastic force. The purpose of this study is to evaluate the effects of heat treatment on the load-deflection properties and transitional temperature range (TTR) of nickel-titanium wires. Methods: Nickel-titanium wires of different diameters ($0.016"\;{\times}\;0.022"$, $0.018"\;{\times}\;0.025"$ and $0.0215"\;{\times}\;0.028"$) were used. The samples were divided into 4 groups as follows: group 4, posterior segment of archwire (24 mm) without heat treatment; group 2, posterior segment of archwire (24 mm) with heat treatment only; group 3, anterior segment with bending and heat treatment; group 4, anterior segment with bending and 1 sec over heat treatment. Three point bending test was used to evaluate the change in load-deflection curve and obtained DSC (different scanning calorimetry) to check changes in $A_f$ temperature. Results: In the three point bending test, nickel-titanium wires with heat treatment only had higher load-deflection curve and loading and unloading plateau than nickel-titanium wires without heat treatment. Nickel-titanium wires with heat treatment had lower Af temperature than nickel-titanium wires without heat treatment. Nickel-titanium wires with heat treatment and bending had higher load-deflection curve than nickel- titanium wires with heat treatment and nickel-titanium wires without heat treatment. Nickel-titanium with heat treatment of over 1 sec and bending had the highest load-deflection curve. Nickel-titanium wires with heat treatment and bending had lower Af temperature, Nickel-titanium wires with heat treatment of over Af sec and bending had the lowest Af temperature. Conclusion: From the results of this study, it can be stated that heat treatment for bending of Nickel-titanium wires does not deprive the superelastic property but can cause increased force magnitude due to a higher load-deflection curve.

Study of Polysulfone Membrane for Membrane-covered Oxygen Probe System (산소 전극 시스템에 사용되는 polysulfone막에 대한 연구)

  • Hong, Suk In;Kim, Hyun Joon;Park, Hee Young;Kim, Tae Jin;Jeong, Yong Seob
    • Applied Chemistry for Engineering
    • /
    • v.7 no.5
    • /
    • pp.877-887
    • /
    • 1996
  • The ideal membranes for membrane-covered oxygen probes system should be selectively permeable for oxygen and chemically inert, and have good mechanical strength. Polysulfone(PSf) was selected to develop the membrane for membrane-covered oxygen electrodes system. PSf membranes have properties such as good reproducibility, good mechanical strength, chemical inertness, and high heat resistance. PSf membranes were cast from polymer solution on the glass plate at constant temperature, and casting solvents used were tetrahydrofuran(THF), methylene chloride, and N-methyl-2-pyrrolidone(NMP). Tricresyl phosphate(TCP) as plasicizer was added to PSf to increase the softness of membrane. The permeation characteristics were observed for pure oxygen and nitrogen through pure PSf membranes by variable volume method and membrane-covered electrode system. The permeability coefficients of oxygen and nitrogen measured by variable volume method were slightly decreased with increasing of upstream pressure. The permeation properties of PSf membrane using methylene choride as casting solvent were not affected by the PSf amount of polymer solution. The permeability coefficients of oxygen and nitrogen for PSf membrane containing TCP were very slightly lower than those for pure PSf membrane, but ideal separation factors were slightly higher. The flexibility of PSf membrane containing 2wt% TCP was better than that of pure PSf membrane. It was expected that this increase in flexibility would solve the difficulty of fixing the membrane to the cathode. The membrane-covered oxygen probes system was composed of anode, cathode and electrolyte. The type of the anode was Ag/AgCl half-cell, that of cathode was Ag, and the electrolyte was 4N KCl solution. The result of sampled current voltametry for PSf membrane showed the plateu region at -0.3V~-1.0V. The correlation coefficient of oxygen partial pressure versus current for PSf membrane was relatively high, 0.99949. It was concluded that PSf membrane was the good candidate for the membrane-covered oxygen probes system.

  • PDF

Careful Approach for Ureteronephrectomy in a Dog with Hydronephrosis causing Dense Adhesion (치밀한 유착조직을 형성한 수신증을 가진 개에서 신요관절제술을 위한 세심한 접근)

  • Kim, Young-Ki;Uhm, Mi-Young;Lee, Scott-S.;Wang, Ji-Hwan;Park, Kee-Tae;Jin, Yeung-Bae;Lee, Hee-Chun;Lee, Hyo-Jong;Yeon, Seong-Chan
    • Journal of Veterinary Clinics
    • /
    • v.26 no.4
    • /
    • pp.353-358
    • /
    • 2009
  • Unilateral ureteronephrectomy was performed in a dog presented with unilateral hydroureter and hydronephrosis. On laparotomy, severe adhesion of the dorsomedial border of the affected kidney to the abdominal aorta longitudinally and caudal pole of the kidney firmly to the ipsilateral ovary were observed. Since it was not possible to ligate the renal artery and vein separately due to severe adhesion tissue, two mass ligations were applied in the medial border of kidney, and the adhesion tissue was transected distal to each ligature. Then, blunt and sharp dissections were performed to isolate dorsomedial border of the kidney from the abdominal aorta, but they brought out unexpected hemorrhage caused by incision of renal artery and it has been suspected that two mass ligations could not include renal artery, which was adhered to dorsomedial border of the kidney. The hemorrhage was controlled by double ligations and electrocautery. In this case report, we recommend that if isolation of renal vessels is impossible due to strict adhesion of kidney to adjacent tissue, the mass ligation could be chosen to isolate and exteriorize the kidney and placed carefully not only at medial border of the kidney, where the renal vessels come into the kidney anatomically but also additional border of the kidney where adhesion tissues are formed.

Selection of Chemicals for Separation of Copulated Moth of Silkworm, Bombyx mori L. (약제에 의한 가잠교미아의 할애효과에 대하여)

  • 박광의;마영일;황석조
    • Journal of Sericultural and Entomological Science
    • /
    • v.26 no.2
    • /
    • pp.11-15
    • /
    • 1984
  • To save the labour reguired for separation of copulated moth during egg Production, some of the chemicals available at the market were on screen test for easy separation of copulated moth of silkworm. The obtained results are summarized as following. 1. In a separation ratio of copulated moth along with a treating time, TCTFE(Trichloro-trifluoroethane) completely separated the copulated moth in 10 minutes. The combinations of TCTFE plus Acetone (87.5 : 12.5 V/V) and TCTFE plus Acetic acid (50 : 50 V/V) take 25minutes for the complete separation of copulated moth. Use of Acetic acid solution only makes 100% separation of copulated moth in one hour and foully minutes and non$.$treatment shows only 47.5% of separation in three and half hours. On the other hand. There is no statistical significance between TCTFE Plus Acetone and control in the egg productivity. 2. The combination of TCTFE Plus Acetone (87.5 : 12.5 V/V) does not infuluence the egg productivity of the moth, showing 443 grains for an average number of egg per moth out of which 417 grains are for the number of fertilized eggs while control shows 452 grains for an avarage number of egg/moth and 428 grains for the number of fertilized eggs. However a sing1e use of TCTFE and Acetic acid shows less egg productivity and number of ferilized eggs per moth, respectively as compared to those of the control. In particular, a single use of acetic acid makes an increase of number of non-egg prodncible moth and it seems to be brought due to a chemical damage. 3. In a rearing test of the egg laid by the chemical treated moth, there are no differences among the treatments in all of the useful characters of the larvae; larval duration, survival rate, cocoon yield, single cocoon weight, single cocoon shell weight and cocoon shell ratio. In these regards, it is recognized that TCTFE can be practically used for the separation of copulated moth and the combination of TCTFE and Acetone promote its efiectiveness on the separation of copulated moth.

  • PDF

Determination of shear wave velocity profiles in soil deposit from seismic piezo-cone penetration test (탄성파 피에조콘 관입 시험을 통한 국내 퇴적 지반의 전단파 속도 결정)

  • Sun Chung Guk;Jung Gyungja;Jung Jong Hong;Kim Hong-Jong;Cho Sung-Min
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2005.09a
    • /
    • pp.125-153
    • /
    • 2005
  • It has been widely known that the seismic piezo-cone penetration test (SCPTU) is one of the most useful techniques for investigating the geotechnical characteristics including dynamic soil properties. As the practical applications in Korea, SCPTU was carried out at two sites in Busan and four sites in Incheon, which are mainly composed of alluvial or marine soil deposits. From the SCPTU waveform data obtained from the testing sites, the first arrival times of shear waves were and the corresponding time differences with depth were determined using the cross-over method, and the shear wave velocity profiles (VS) were derived based on the refracted ray path method based on Snell's law and similar to the trend of cone tip resistance (qt) profiles. In Incheon area, the testing depths of SCPTU were deeper than those of conventional down-hole seismic tests. Moreover, for the application of the conventional CPTU to earthquake engineering practices, the correlations between VS and CPTU data were deduced based on the SCPTU results. For the empirical evaluation of VS for all soils together with clays and sands which are classified unambiguously in this study by the soil behavior type classification Index (IC), the authors suggested the VS-CPTU data correlations expressed as a function of four parameters, qt, fs, $\sigma$, v0 and Bq, determined by multiple statistical regression modeling. Despite the incompatible strain levels of the down-hole seismic test during SCPTU and the conventional CPTU, it is shown that the VS-CPTU data correlations for all soils clays and sands suggested in this study is applicable to the preliminary estimation of VS for the Korean deposits and is more reliable than the previous correlations proposed by other researchers.

  • PDF