• Title/Summary/Keyword: Disk-till

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Effect of Tillage System on the Forage Production and Soil Characteristics of Silage Corn (경운방법이 사일리지용 옥수수의 사초생산성 및 토양특성에 미치는 영향)

  • Kim, Jong-Duk;Kwon, Chan-Ho;Gu, Yang-Hae;Shin, Mung-Su
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.28 no.4
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    • pp.307-314
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    • 2008
  • No comprehensive tillage system of corn (Zea mays L.) has been conducted in Korea. Therefore, this experiment was carried to determine soil characteristics, weed and forage production in tillage system of corn. Plot was allotted to one of four treatments in a randomized block design using tillage system. The four treatments were (T1) conventional tillage, plow and rotary till, (T2) rotary till, (T3) disk till, and (T4) no-till system. In soil characteristics before planting and after harvest of corn, pH and organic matter at planting date was higher than at harvest date, however, there were no difference among tillage system. Days from planting to silking of no-till was the longest among tillage system. Lodging resistance of disk and no-till were higher than conventional and rotary till due to its thicken stem diameter. Main weed in corn field are barnyard grass (Echinochloa crusgall), velvetleaf(Abutilon avicennae), crabgrass (Digitatia saguinalis), and redroot pigweed (Amaranthus retroflexus). Weed population was lower in no-till than others tillage system. Dry matter (DM) content and ear percentage of conventional and rotary till were higher than others in corn field. However, DM and total digestible nutrients (TDN) yields of disk and no-till were higher than those of conventional and rotary till. Therefore, disk and no-till are more suitable in corn silage system because of high lodging resistance and forage yield, and low weed population.

Physical and Chemical Management Practices for Improving Water Quality in Channel Catfish Ictalurus punctatus Aquaculture

  • Seo, Jin-Won
    • Journal of Aquaculture
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    • v.15 no.1
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    • pp.49-60
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    • 2002
  • Research on practices for improving water quality in channel catfish Ictalurus punctatus ponds was conducted at the Auburn University Fisheries Research Station, Auburn, Alabama, in 1998 and 1999. The objective of this two-year study was to determine better management practices to enhance water quality and improve production efficiency. In the first year, oxidation of bottom soil by drying, tilling, and applying sodium nitrate was performed (dry-till and dry-till with sodium nitrate treatments). The second year, based on the results obtained during the first year, precipitation of phosphorus (P) from water by applying gypsum was compared to the dry-till treatment (dry-till and dry-till with gypsum treatments). Control ponds were not subjected to bottom drying, tilling, sodium nitrate, or gypsum treatment. Channel catfish fingerings were stocked at 15,000/ha. In the first year, water in ponds from dry-till and dry-till with sodium nitrate treatments had lower concentrations (P < 0.01) of soluble reactive P, nitrate ($NO_{3} ^{-}) and nitrite ($NO_{2} ^{-}) nitrogen (N), total ammonia ($NH_3$) nitrogen, total suspended solids and turbidity, and higher values of pH, Secchi disk visibility, total alkalinity, total hardness, and calcium ($Ca^{2+}) hardness than water in control ponds. Ponds of the dry-till treatment also had lower concentrations (P < 0.01) of total P and total N than control ponds. Total fish production and survival rate did not differ among the treatments (P > 0.05). The findings suggested that drying and tiling pond bosoms between crops could achieve water quality improvement. Applying sodium nitrate to dry, tilled pond bosoms did not provide water quality improvement. In the second year, the treatment with the best results from the first year, dry-till, was compared with a dry-till with gypsum treatment. Enough gypsum was applied to give a total hardness of about 200 mg/L, and gypsum was reapplied as needed to maintain the hardness. Compared to the control, dry-till and dry-till with gypsum treatments had lower concentrations (P < 0.01) of total and soluble reactive P, total N, and total $NH_3$-N, and higher concentrations (P < 0.01) of dissolved oxygen. Ponds of the duty-till with gypsum treatment also had lower concentrations (P < 0.01) of chlorophyll $\alpha$, chemical oxygen demand, and total alkalinity than the control. Total fish production and survival rate did not differ (P > 0.05) among the treatments. These findings suggest that drying and tilling pond bosoms between crops and treating low hardness waters with gypsum could achieve water Quality improvement.

Meridional Circulations in a Sliced Cylinder (기울어진 회전 원판에 의한 원통형 용기내의 자오면 유동의 크기에 관한 연구)

  • KIM Jae Won;LIM Hong Sick
    • 한국전산유체공학회:학술대회논문집
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    • 1996.05a
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    • pp.52-57
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    • 1996
  • Mixing is most important for developing an electric washer which transforms angular momentum from rotating solid wall to laundry clothes inside it. For magnification of this mixing effect, some inventions are introduced to washing machine system, i. e., washing plate, washing rod, and even for washing cap in a model of a Korean manufacture. However, the previous efforts show dissatisfaction up till now. In this paper, a triumph to enhance mixing effects to increase washing performance is presented and verified by numerical investigation. The present model to simulate a washing tub is the simple circular cylinder with two endwall disks which is completely filled with a viscous liquid. The present improvement is to change mounting position of a bottom disk of the model cylinder. Therefore, the aim of this work just proposes a new idea, which is numerically inspected, to a producer of washing machine, In detail, this invention is alternating the mounting position of a rotating bottom disk. Actually skewed pulsator is placed in steady of a flat disk, so the two endwall disks at top and bottom are not in parallel. The angle between an inclined bottom disk and the horizontal plane is fixed as 5 degree and physical domain to consider poses a sliced cylinder. Flow fields in both a right circular cylinder and the present improved model are fully depicted by numerical integration on a body fitted nonorthogonal regular uniform grid system. Numerical data to explain flow structure are plotted for understanding of the effects of the inclined disk. Also enhanced mixing effects by the inclined rotating disk are gauged by accurate numerical data used in this work.

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Arteriovenous fistula formation following disk surgery: one case report (추간원판 절제술후 발생한 동-정맥루 수술치험 1)

  • Yu, Si-Won;Choe, Hyeong-Ho;Jang, Jeong-Su
    • Journal of Chest Surgery
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    • v.17 no.2
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    • pp.315-320
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    • 1984
  • A vascular complication caused by lumbar disc surgery is not infrequent till recently after the report by Linton and White in 1945. Thereafter, many reports about the accidental injuries to the great vessels anterior to the lumbar area had been reported. In June, 1982, we experienced one case of arteriovenous fistula between right common lilac artery and inferior vena cava which was corrected surgically. The arteriovenous fistula caused by lumbar disc surgery and its review of the literature and presented.

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Arteriovenous fistula formation following disk surgery (추간원판절제술후 발생한 동-정맥루공 수술치험 1례)

  • Kim, Jong-Ho;Kim, Yong-Jin
    • Journal of Chest Surgery
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    • v.15 no.4
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    • pp.428-431
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    • 1982
  • A vascular complication caused by lumbar disc surgery is not infrequent till recently after the first report by Linton & White in 1945. In October 1980, we experienced one case of arteriovenous fistula following lumbar disc surgery in the department of thoracic surgery, CAFGH. The A-V fistula was situated between left common iliac artery and vein, which was confirmed by angiography easily. The A-V fistula was corrected surgically by Taylor`s method successfully without complication.

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A Space Efficient Indexing Technique for DNA Sequences (공간 효율적인 DNA 시퀀스 인덱싱 방안)

  • Song, Hye-Ju;Park, Young-Ho;Loh, Woong-Kee
    • Journal of KIISE:Databases
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    • v.36 no.6
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    • pp.455-465
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    • 2009
  • Suffix trees are widely used in similar sequence matching for DNA. They have several problems such as time consuming, large space usages of disks and memories and data skew, since DNA sequences are very large and do not fit in the main memory. Thus, in the paper, we present a space efficient indexing method called SENoM, allowing us to build trees without merging phases for the partitioned sub trees. The proposed method is constructed in two phases. In the first phase, we partition the suffixes of the input string based on a common variable-length prefix till the number of suffixes is smaller than a threshold. In the second phase, we construct a sub tree based on the disk using the suffix sets, and then write it to the disk. The proposed method, SENoM eliminates complex merging phases. We show experimentally that proposed method is effective as bellows. SENoM reduces the disk usage less than 35% and reduces the memory usage less than 20% compared with TRELLIS algorithm. SENoM is available to query efficiently using the prefix tree even when the length of query sequence is large.

EFFECTS OF CRYOPRESERVATIVE AGENTS ON THE REPAIR OF THE TEMPOROMANDIBULAR JOINT DISK WITH ALLOGENEIC CARTILAGE GRAFTS IN RABBITS (동종 연골을 이용한 가토 측두하악관절원판 재건시 냉동 보존제의 영향에 관한 실험적 연구)

  • Kim, Won-Gyu;Kim, Soo-Nam;Min, Seung-Ki;Sung, Gil-Hyun;Keon, Heak-Do
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.15 no.4
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    • pp.303-316
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    • 1993
  • The auricular cartilage grafts have been widely used in replacement of the temporomandibular joint disk. Cartilage grafts itself have a low metabolism and high survival rate after grafting. In processing the grafting materials, it was important to preserve the properties of chondrocyte proper. We used 15% glycerol and 10% DMSO (Dimethyl Sulfoxide) solutions for cartilage fixation before deep freezing. We have performed the allogenic auricular cartilage graft in the temporomandibular joint of 20 rabbits which 10 specimen was treated with 15% glycerol and the other 10 specimen was treated with 10% DMSO respectively and examined in 1, 2, 4, 6 and 8 weeks after operation histopathologically. The result were : 1. Inflammatory cell infiltration around the grafted material appeared more glycerol groups than DMSO groups at 1 week, but each group has no differences after 2 weeks. 2. Degenerative changes of grafted auricular chondrocytes were more deveolped in glycerol group than DMSO groups till 4 weeks, but there were no differences between two groups after 6 weeks. 3. Fibrous union between grafted fragment and mandibular condyle was prominent in DMSO group. 4. Vascular proliferation of the grafted auricualr cartilage was more developed in DMSO groups than glycerol group in early stage. 5. Amount of the additional growth of grafted auricular cartilage was more existed in DMSO groups than glycerol group. 6. General survival rate after grafting was more prominent in DMSO group. In summary, allogenic auricular cartilage grafts treated with 15% glycerol and 10% DMSO solution have supported to survivalbility as a cryopreservative agents, especially DMSO groups have little inflammatory cell infiltration in early stages and degenerative changes and additional growth are more prominent than glycerol groups.

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