• Title/Summary/Keyword: clearing method

Search Result 133, Processing Time 0.029 seconds

A Study on a New Working System of Mechanical Land Clearing and Development of Fertile Soil(III) (기계개간의 새로운 작업체계와 숙지화촉진에 관한 연구(III))

  • Hwang, Eun
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.15 no.2
    • /
    • pp.3007-3017
    • /
    • 1973
  • The cutting of soil from upside to under side land clearing method(II) for permanent farming by the teraacing method of the land clearing has been presented to be desirable and in order to prove this fact non-fertilizers, lime+N.P.K. and compost+lime+N.P.K. are respectively raised to obtain the following results: 1) In case of apprepriate manuring and good care of raising any method of land clearing may be recommendable but the cutting of soil from upside to under side land clearing method is much desirable when manuring and raising care are in bad condition. 2) The respective yield ratio of non-fertilizers, lime+N.P.K. and compost+lime+N.P.K. increases to the ratio of 1:2:4.5 and the harvest of pasture at last approaches to the criterion of yield of ladino clover, 3,000kg/ha in the arable land.

  • PDF

Change of Ice Resistance of Ice-Breaking Tanker According to Frictional Coefficient (빙마찰계수에 따른 쇄빙탱커의 빙저항 변화)

  • Cho, Seong-Rak;Lee, Sungsu;Lee, Yong-Chul;Yum, Jong-Gil;Jang, Jinho
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.58 no.3
    • /
    • pp.175-181
    • /
    • 2021
  • This study describes the model tests in ice according to the frictional coefficient of an ice-breaking ship and the change in ice resistance by the analysis method for each component of ice resistances. The target vessel is a 90K DWT ice-breaking tanker capable of operating in ARC7 ice conditions in the Arctic Ocean, and twin POD propellers are fitted. The hull was specially painted with four different frictional coefficients on the same ship model. The total ice resistance can be separated by ice breaking, ice buoyancy, ice clearing resistances through the tests in level ice, pre-sawn ice and creep test in pre-sawn ice under sea ice thickness of 1.2 m and 1.7 m. Ice resistance was analyzed by correcting the thickness and bending strength of model ice by the ITTC correction method. As the frictional coefficient between the hull and ice increases, ice buoyancy and clearing resistances increase significantly. When the surface of the hull is rough, it is considered that the broken ice pieces do not slip easily to the side, resulting in an increase in ice buoyancy resistance. Also, the frictional coefficient was found to have a great influence on the ice clearing resistance as the ice thickness became thicker.

Study on the Improvement of Land Clearing Methods by Bulldozer & Fertilization of Cleared Soil (불도우저에 의한 개간 공법의 개선과 숙지화에 관한 연구)

  • Hwang, Eun
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.17 no.1
    • /
    • pp.3627-3641
    • /
    • 1975
  • The Government is trying to increase total food grain yield to meet national self sufficiency by means of increasing unit yield as well as extending crop land, and this year he set the target of 321,000 hectare of forest to clear for cropping. This study was carried to investigate the most efficient method of clearing hillock by bulldozer, and successful method to develope yielding potential of newly cleared land in short term. Since the conventional land clearing method is just earth leveling and root removing neglecting top soil treatment, the growth of crop was poor and farmer tends not to care the land. The top-soil-furrowing method is applied through out this study, that is advantageous especially for the land having shallow top soil and low fertility like Korean forest. In this study, various operating method were tried to find out most efficient method separately in connection with the land slope less than 25 percent and over, and several fertilizing methods to develop yielding potential. The results are as follows; 1) For the natural land slope utilization method, applicable to the land having less than 25 percent slope, reverse operating was more efficient than using forward gear of bulldozer. The operating time was 3 hour 32 minutes and 36 seconds using forward gear was 2 hour 32 minutes and 30 seconds for reverse gear operation per 1,000 square meter. 2) Bulldozer having angle blade adjustment needed 7hr 15min. for constructing of terrace per 10a compaire with the one having angle & tilt adjustment needed 6hr 4min for same operations. Specially there is significant difference for operation time of first period (earth cutting) such as bulldozer having angle blade adjustment needed 3hr 56min compaired with the one having angle & tilt adjustment 3hr 59min. In construction of terrace, the bull-dozer having tilting and angle blade adjustment was most suitable and performed efficiently. 3) For the fertilizer application treatment, the grass (Ladino clover) yield in first year was almost same as ordinary field's in the plot applied(N.P.K+lime+manure) while none fertilizer plot showed one tenth of it, and (N.P.K.+lime) applied plot yielded on third. 4) The effect of different land clearing method to yield showed significant difference between each treatment especially in the first year, and the conventional method was the lowest. In the second year, still conventional terracing plot yielded only half of ordinary field while the other plots showed as same as ordinary field's. 5) The downward top soil treatment plot showed most rapid improvement in soil structure during one year physio chemically, it showed increase in pH rate and organic composition, and the soil changed gradually from loam to sand-loam and the moisture content increased against the pF rate, and it gives good condition to grow hay due to the increase of field water capacity with higher available water content. 6) Since the soil of tested area was granite, the rate of soil errosion was increased about 2 to 5 percent influencing in soil structure more sand reducing clay content, and an optimum contour farming method should be prepared as a counter measure of errosion.

  • PDF

A Literature Study of Atopic Dermatitis for Children (소아 아토피 피부염에 대한 문헌적 고찰(최근 중의잡지를 중심으로))

  • Kim Mi-Jung;Lee Seung-Yeon
    • The Journal of Pediatrics of Korean Medicine
    • /
    • v.14 no.2
    • /
    • pp.169-184
    • /
    • 2000
  • A literature study was progressed for oriental medical treatment for atopic dermatitis. Atopic dermatitis is a chronic or chronically relapsing, pruritic dermatitis. In oriental medical treatment is classified into the treatment of inside(herb tea), treatment of outside(medicine for external application), treatment of inside & outside. The method of inside treatment is improving in health for the spleen and clearing wetness(健脾利濕), extinguishing wind and refreshing fever(消風淸熱), nourishing blood and making dryness gloss(養血潤燥). The method of outside treatment is refreshing fever and removing wetness(淸熱燥濕), counteracting the poison and getting rid of itch(解毒止痒), removing the boil and forming proud flesh(消腫生肌). The method of inside & outside is improving in health for the spleen and clearing wetness(健脾利濕), refreshing fever and getting rid of itch(淸熱止痒). refreshing blood and extinguishing wind(凉血祛風).

  • PDF

A Literature Study on Surgical Disease of the Four Famous Physicians in JinYuan Period (金元四大家의 外科疾患에 對한 硏究;(癰疽瘍瘡을 中心으로))

  • Kim, Hee-taek;Roh, Sek-seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.12 no.1
    • /
    • pp.179-214
    • /
    • 1999
  • The result were as follows: 1. Yu Wan So(劉完素) regarded the cause of surgical disease as the heat(熱). He used the three method to drain(疏通), promoting pus drainage(托裏) and the balance between ying-energy(營氣) and wei-energy(衛氣). 2. Jang Jong Jeung(張從正) only refered to medicines without entire theory. 3. Lee Dong Won(李東垣) regarded the cause of surgical disease as the greasy diet(膏梁厚味), damp air(濕氣), wetness heat(濕熱). For each treatment he used the method of Yu Wan So's treatment and emphasized the balance between ying-energy(營氣) and wei-energy(衛氣), stomach energy(胃氣). 4. Ju Jin Heung(朱震亨) distinguished the cause of surgical disease from enternal(內), external(外) and channel(經). For each treatment he used the method to drain(疏通), promoting pus drainage(托裏) and the balance between ying-energy(營氣) and wei-energy(衛氣). The first stage used the clearing away heat and toxic materials(淸熱解毒) and the last stage used the invigoration and dispersion(補托). 5. Yu Wan So(劉完素) used to be very busy of Moschus(麝香), Alumen(白礬), Olibanum(乳香), Coptidis Rhizoma(黃連), Minium(黃丹) and Scutel1ariae Radix(黃芩) In classification of the medical action, great part of the medicine are activating blood circulation to dissipate blood stasis(活血祛瘀), clearing away heat and toxic materials( 淸熱解毒) and external application(外用). 6. Jang Jong Jeung(張從正) used to be very busy of Olibanum(乳香), Angelicae Gigantis Radix(當歸), Minium(黃丹), Myrrha(沒藥), Calomelas(輕粉), Rhei Radix Et Rhizoma(大黃) and Phellodendri Cortex(黃柏). In classification of the medical action, great part of the medicine arc activating blood circulation to dissipate blood stasis(活血祛瘀), clearing away heat and toxic materials(淸熱解毒) and diverged wind-cold evil(發散風寒). 7. Lee Dong Won(李東垣) used to be very busy of Forsythiae Fructus(連翹), Scuteliariae Radix(黃芩), Angelicae Gigantis Radix(當歸). Astragali Radix(황기), Glycyrrhizae Radix(炙甘草), Bupleuri Radix(紫胡), Phellodendri Cortcx(黃柏), and Coptidis Rhizoma(黃連). In classification of the medical action, great part of the medicine are activating blood circulation to dissipate blood stasis(活血祛瘀), regulating vital energy(理氣) and clearing away heat and toxic materials(淸熱解毒). 8. Ju Jin Heung(朱震亨) used to be very busy of Glycyrrhizae Radix(甘草), Astragali Radix(황기), Angelicae Gigantis Radix(當歸), Phellodendri Cortex(黃柏), Scutellariae Radix(黃芩), Ginseng Radix(人蔘), Qlibanum(乳香). In classification of the medical action, great part of the medicine are clearing away heat and toxic materiaIs(淸熱解毒), activating blood circulation to dissipate blood stasis(活血祛瘀) and diverged wind-cold evil(發散風寒).

  • PDF

A Fast Contingency Screening Algorithm for On-line Transient Security Assessment Based on Stability Index

  • Nam, Hae-Kon;Kim, Yong-Hak;Song, Sung-Geun;Kim, Yong-Gu
    • KIEE International Transactions on Power Engineering
    • /
    • v.2A no.4
    • /
    • pp.131-135
    • /
    • 2002
  • This paper describes a new ultra-fast contingency screening algorithm for on-line TSA without time simulation. All machines are represented in a classical model and the stability index is defined as the ratio between acceleration power during a fault and deceleration power after clearing the fault. Critical clustering of machines is done based on the stability index, and the power-angle curve of the critical machines is drawn assuming that the angles of the critical machines increase uniformly, while those of the non-critical ones remain constant. Finally, the critical clearing time (CCT) is computed using the power-angle curve. The proposed algorithm is tested on the KEPCO system comprised of 900-bus and 230-machines. The CCT values computed with the screening algorithm are in good agreement with those computed using the detailed model and the SIME method. The computation time for screening about 270 contingencies is 17 seconds with 1.2 GHz PC.

Effects of Shihoieokgan-Tang with Other Herbs and Formulae Pretreatment on the Change of Corticosterone Induced by Immobilization Stress in Mice (시호억간탕(柴胡抑肝湯) 등 약물(藥物)의 처치(處置)가 구속(拘束) 스트레스로 유발(誘發)된 생쥐의 혈(血) 중(中) Corticosterone 변화(變化)에 미치는 영향(影響))

  • Kim Hyun-Jun;Lee Tae-Hee
    • Herbal Formula Science
    • /
    • v.10 no.2
    • /
    • pp.57-72
    • /
    • 2002
  • To investigate the effect of Qi promoting-agents, clearing heat of deficiency type-agent, clearing heat of excessive type-agent, warming interior part of body-agent and Shihoieokgan-Tang against the immobilization stress, Cypri Rhizama, Auranti pericarpium, Aucklandiae Radix and Bupleuri Radix, Soyo-San, Hwangyeonhaedok-Tang, Geongangbuja-Tang and Shihoieokgan-Tang was administered intragastically 1hr prior to immobilizaiton stress and the change of corticosterone level has been measured by the flurometric method. The results obtained are as follows: 1. Qi promoting-agents(Cypri Rhizama, Auranti pericarpium, Aucklandiae Radix and Bupleuri Radix) showed mildly reducing effect or did not shown the reducing effect against the elevated coritocostereone level induced by the immobilization stress in the mice. 2. Hwangyeonhaedok-Tang, Gungangbuza-Tang, and Soyo-San did not show the reducing effect against the elevated corticostereone level induced by the immobilization stress in the mice. 3. Shihoieokgan-San was effective against the elevated corticosterone level induced by the immobililzation stress at 1g/kg, 3g/kg respectively. Consequently these data proved that Qi pomoting-agents as single herb(Cypri Rhizama, Auranti pericarpium, Aucklandiae Radix and Bupleuri Radix), clearing heat of deficiency type-agent(Soyo-San), warming interior part of the body(Gungangbuza-Tang), clearing heat of excessive type-agent(Hwangyeonhaedok-Tang) have no effect to decrease the elevated corticosterone level in mice exposed to the immobilization stress. Therefore our study revealed that Shihoieokgan-San which has the effects of herbs and formulae mentioned above decreased the elevated corticosterone level in mice exposed to the immobilization stress significantly.

  • PDF

Occurrence and Multiplex PCR Detection of Citrus Yellow Vein Clearing Virus in Korea

  • Taemin Jin;Ji-Kwang Kim;Hee-Seong Byun;Hong-Soo Choi;Byeongjin Cha;Hae-Ryun Kwak;Mikyeong Kim
    • The Plant Pathology Journal
    • /
    • v.40 no.2
    • /
    • pp.125-138
    • /
    • 2024
  • Citrus yellow vein clearing virus (CYVCV) is a member of the Alphaflexiviridae family that causes yellow vein clearing symptoms on citrus leaves. A total of 118 leaf samples from nine regions of six provinces in Korea were collected from various citrus species in 2020 and 2021. Viral diagnosis using next-generation sequencing and reverse transcription polymerase chain reaction (RT-PCR) identified four viruses: citrus tristeza virus, citrus leaf blotch virus, citrus vein enation virus, and CYVCV. A CYVCV incidence of 9.3% was observed in six host plants, including calamansi, kumquat, Persian lime, and Eureka lemon. Among the citrus infected by CYVCV, only three samples showed a single infection; the other showed a mixed infection with other viruses. Eureka lemon and Persian lime exhibited yellow vein clearing, leaf distortion, and water-soak symptom underside of the leaves, while the other hosts showed only yellowing symptoms on the leaves. The complete genome sequences were obtained from five CYVCV isolates. Comparison of the isolates reported from the different geographical regions and hosts revealed the high sequence identity (95.2% to 98.8%). Phylogenetic analysis indicated that all the five isolates from Korea were clustered into same clade but were not distinctly apart from isolates from China, Pakistan, India, and Türkiye. To develop an efficient diagnosis system for the four viruses, a simultaneous detection method was constructed using multiplex RT-PCR. Sensitivity evaluation, simplex RT-PCR, and stability testing were conducted to verify the multiplex RT-PCR system developed in this study. This information will be useful for developing effective disease management strategies for citrus growers in Korea.

Parallel Operation Control Method of Grid-connected Inverters with Seamless Transfer for Energy Storage System in Microgrid (마이크로그리드에서 에너지 저장시스템을 위한 무순단 절체 기능을 갖는 계통연계형 인버터의 병렬운전 제어기법)

  • Park, Sung-Youl;Kim, Joo-Ha;Jung, Ah-Jin;Choi, Se-Wan
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.21 no.3
    • /
    • pp.200-206
    • /
    • 2016
  • In the microgrid, inverters for energy storage system are generally constructed in a parallel structure because of capacity expandability, convenience of system maintenance, and reliability improvement. Parallel inverters are required to provide stable voltage to the critical load in PCC and to accurately share the current between each inverter. Furthermore, when islanding occurs, the inverters should change its operating mode from grid-connected mode to stand-alone mode. However, during clearing time and control mode change, the conventional control method has a negative impact on the critical load, that is, severe fluctuating voltage. In this study, a parallel operation control method is proposed. This method provides seamless mode transfer for the entire transition period, including clearing time and control mode change, and has accurate current sharing between each inverter. The proposed control method is validated through simulation and experiment.

Hybrid Transient Stability Analysis Using Object-oriented method (객체지향기법을 적용한 하이브리드 과도안정도 해석)

  • Park, Ji-Ho
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.451-452
    • /
    • 2007
  • In this paper, we simulate power system transient stability using object-oriented programming(OOP). OOP is a more flexible method than procedual programming. There are several advantages in dynamic system simulation using OOP. We also calculate critical fault clearing time using energy functions for detailed models.

  • PDF