• 제목/요약/키워드: neutral zone

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Classification and Spatial Variability Assessment of Selected Soil Properties along a Toposequence of an Agricultural Landscape in Nigeria

  • Fawole Olakunle Ayofe;Ojetade Julius Olayinka;Muda Sikiru Adekoya;Amusan Alani Adeagbo
    • Journal of Forest and Environmental Science
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    • v.39 no.3
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    • pp.180-194
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    • 2023
  • This study characterize, classify and evaluates the function of topography on spatial variability of some selected soil properties to assist in designing land management that support uniform agricultural production. The study site, an agricultural land, was part of the derived savanna zone in southwest Nigeria. Four soil profile pits each were established along two delineated toposequence and described following the FAO/UNESCO guidelines. Samples were collected from the identified genetic horizons. Properties of four soil series developed on different positions of the two delineated Toposequence viz upper, middle, lower slopes and valley bottom positions respectively were studied. The soil samples were analysed for selected physical and chemical properties and data generated were subjected to descriptive and inferential statistics. The results showed that soil colour, depth and texture varied in response to changes in slope position and drainage condition. The sand content ranged from 61 to 90% while the bulk density ranged between 1.06 g cm-3 to 1.68 g cm-3. The soils were neutral to very strongly acid with low total exchangeable bases. Available phosphorus value were low while the extractable micronutrient concentration varied from low to medium. Soils of Asejire and Iwo series mapped in the study area were classified as Typic isohyperthermic paleustult, Apomu series as Plinthic isohyperthermic paleustult and Jago series as Aquic psamment (USDA Soil Taxonomy). These soils were correlated as Lixisol, Plinthic Lixisol and Fluvisol (World Reference Based), respectively. Major agronomic constraints of the soils associations mapped in the study area were nutrient availability, nutrient retention, slope, drainage, texture, high bulk density and shallow depth. The study concluded that the soils were not homogenous, shows moderate spatial variation across the slope, had varying potentials for sustainable agricultural practices, and thus, the agronomic constraints should be carefully addressed and managed for precision agriculture.

The Volcanic Eruption Velocity and Tumulus of Jeju Island Controlled by the Natural Intelligence (자연 지능 제어에 의한 제주도의 화산 폭발 속도와 튜물러스)

  • Lee, Seong kook;Lee, Moon Ho;Kim, Jeong Su
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.3
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    • pp.493-499
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    • 2022
  • This paper reports the results of the eruption of a volcano on Jeju Island at a certain rate, and the tumulus formed after the eruption and the basalt that erupted from the middle of Mt. Halla washed up to the sea. We analyzed the speed when basalt underground magma breaks through the neutral zone on the ground with an absolute temperature of about 1000K and explodes at an absolute temperature of 1200K at an altitude of 1950m. The density of combustion gas becomes smaller than the surrounding air due to the plume volcanic eruption, which is the heat flow of the flame column due to buoyancy, and buoyancy is generated and an updraft is formed. Flame pillars are classified as continuous, intermittent, and buoyant flame zones. As the speed of the flame pillar of Mt. Halla (1950m) falls from the highest point it has risen, potential energy is converted into kinetic energy and is caused by the flow of fluid, solving these two equations equal, the volcanic eruption velocity is 87.5 m/s. At this time, the density of magma is inversely proportional to the temperature. Geomunoreum (456m) had an explosion speed of 42.6m/s.

Cervical spine reconstruction after total vertebrectomy using customized three-dimensional-printed implants in dogs

  • Ji-Won Jeon;Kyu-Won Kang;Woo-Keyoung Kim;Sook Yang;Byung-Jae Kang
    • Journal of Veterinary Science
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    • v.25 no.1
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    • pp.2.1-2.14
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    • 2024
  • Background: Sufficient surgical resection is necessary for effective tumor control, but is usually limited for vertebral tumors, especially in the cervical spine in small animal neurosurgery. Objective: To evaluate the primary stability and safety of customized three-dimensional (3D)-printed implants for cervical spine reconstruction after total vertebrectomy. Methods: Customized guides and implants were designed based on computed tomography (CT) imaging of five beagle cadavers and were 3D-printed. They were used to reconstruct C5 after total vertebrectomy. Postoperative CT images were obtained to evaluate the safety and accuracy of screw positioning. After harvesting 10 vertebral specimens (C3-C7) from intact (group A) and implanted spines (group B), implant stability was analyzed using a 4-point bending test comparing with groups A and C (reconstituted with plate and pins/polymethylmethacrylate after testing in Group A). Results: All customized implants were applied without gross neurovascular damage. In addition, 90% of the screws were in a safe area, with 7.5% in grade 1 (< 1.3 mm) and 2.5% in grade 2 (> 1.3 mm). The mean entry point and angular deviations were 0.81 ± 0.43 mm and 6.50 ± 5.11°, respectively. Groups B and C significantly decreased the range of motion (ROM) in C3-C7 compared with intact spines (p = 0.033, and 0.018). Both groups reduced overall ROM and neutral zone in C4-C6, but only group B showed significance (p = 0.005, and 0.027). Conclusion: Customized 3D-printed implants could safely and accurately replace a cervical vertebra in dog cadavers while providing primary stability.

Recovery and Utilization of Proteins and Lipids from Washing Wastewater in Marine Manufacture by Isoelectric Point Precipitation Method 1. The Coagulation Treatment for Washing Wastewatfr of Minced Mackerel Meat (수산가공공장 폐액의 등전점 침전처리에 의한 유용성분 재회수 이용 1. 고등어 육 고기풀 제조시 발생되는 폐액의 처리장치 개발)

  • 서재수;조순영
    • KSBB Journal
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    • v.10 no.1
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    • pp.1-8
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    • 1995
  • A lot of water soluble proteins and lipids are released from minced mackerel meat and lost into the washing waste during the leaching process of Kamaboko or surimi manufacture. The removed proteins and lipids are not only an edible things but also a big burden for treating the wastewater. In order to recover the proteins from the effluent and to use as food stuff, the "pH-shifting" treatment, a modified isoelectric point precipitation method, was tried. This method is based on a myogen-aggregation phenomenon, which occurs when a solution of sarcoplasmic proteins is acidified or alkalified beyond the critical pH zone of 2∼3 or 12∼13 respectively and then neutralized. The maximum amount of precipitation was obtained by shifting the pH of the wastewater from original pH to isoelectric point (pH 4) or alkali pH 12 and then changing to neutral pH. The precipitates were easily collected by filteration or centrifuging at 10,000rpm. The oils which were only floating in the washing wastewater are easily recovered by seperating with oil separator after pouring. The recovered proteins were slightly denaturated during this pH shifting precipitation process, while the composition of amino acids was good balance as a food.

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Occurrences of Hot Spring and Potential for Epithermal Type Mineralization in Main Ethiopian Rift Valley (주 에티오피아 열곡대 내 온천수의 산출특성 및 천열수형 광상의 부존 잠재성)

  • Moon, Dong-Hyeok;Kim, Eui-Jun;Koh, Sang-Mo
    • Economic and Environmental Geology
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    • v.46 no.3
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    • pp.267-278
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    • 2013
  • The East African Rift System(EARS) is known to be hosted epithermal Au-Ag deposits, and the best-known example is Main Ethiopian Rift Valley(MER) related to Quaternary bimodal volcanism. Large horst-graben system during rifting provides open space for emplacement of bimodal magmas and flow channel of geothermal fluids. In recent, large hydrothermally altered zones(Shala, Langano, and Allalobeda) and hot spring related to deeply circulating geothermal water have been increasing their importance due to new discoveries in MER and Danakil depression. The hot springs in Shala and Allalobeda occur as boiling pool and geyser on the surface, whereas some areas didn't observe them due to decreasing ground water table. The host rocks are altered to quartz, kaolinite, illite, smectite, and chlorite due to interaction with rising geothermal water. The hot springs in MER are neutral to slightly alkaline pH(7.88~8.83) and mostly classified into $HCO_3{^-}$ type geothermal water. They are strongly depleted in Au, and Ag, but show a higher Se concentration of up to 26.7 ppm. In contrast, siliceous altered rocks around hot springs are strongly enriched in Pb(up to 33 ppm, Shala), Zn(up to 313 ppm, Shala), Cu(up to 53.1 ppm, Demaegona), and Mn(up to 0.18 wt%t, Shala). In conclusion, anomalous Se in hot spring water, Pb, Zn, Cu, and Mn in siliceous altered rocks, and new discoveries in MER have been increasing potential for epithermal gold mineralization.

Ductility Evaluation of Circular Hollow Reinforced Concrete Columns with Internal Steel Tube (강관 보강 중공 R.C 기둥의 연성 평가 해석)

  • Han, Seung Ryong;Lim, Nam Hyoung;Kang, Young Jong;Lee, Gyu Sei
    • Journal of Korean Society of Steel Construction
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    • v.15 no.1
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    • pp.1-8
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    • 2003
  • In locations where the cost of concrete is relatively high or in situations where the weight of concrete members has to be kept to a minimum, it may be more economical to use hollow reinforced concrete vertic al members. Hollow reinforced concrete colun-ms with a low axial load, a moderate longitudinal steel percentage and a reasonably thick wall were found to perform in a ductile manner at the flexural strength, similar to solid columns. Hollow reinforced concrete columns with a high axial load, a high longitudinal steel percentage, and a thin wall were found, however, to behave in a brittle manner at the flexural strength, since the neutral axis is forced to occur away from the inside face of the tube towards the section centroid and, as a result, crushing of concrete occurs near the unconfined inside face of the section. If, however, a steel tube is placed near the inside face of a circular hollow column, the column can be expected not to fail in a brittle manner through the disintegration of the concrete in the compression zone. A design recommendation and example through the moment-curvature analysis program for curvature ductility are herein presented. A theoretical moment-curvature analysis for reinforced concrete columns, indicating the available flexural strength and ductility, can be conducted, providing that the stress-strain relation for the concrete and steel are known. In this paper, a unified stress-stain model for confined concrete by Mander is developed foi members with circular sections.

Comparative Studies on Static Windrow and Aerated Static Pile Composting of the Mixtures of Cattle Manure and Rice Hulls -I. Variation of Physico-chemical Parameters (우분뇨와 왕겨 혼합물의 퇴비화에서 정치식과 통기퇴적식의 비교연구 -I. 퇴비재료의 이화학적 환경변화)

  • Sohn, Bo-Kyoon;Hong, Ji-Hyung;Park, Keum-Joo
    • Korean Journal of Soil Science and Fertilizer
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    • v.29 no.4
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    • pp.403-410
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    • 1996
  • Variations of temperature and physicochemical environment during composting of a mixtures(2:1, v/v) of cattle manure and rice hulls(CMR) in two different composting methods, static windrow(SW) and aerated static pile system(ASPS), were monitored for evaluating the efficient composting system in greenhouse. The pH of composting materials increased to around 8.9 initially, then decreased and stabilized slowly to the neutral value. Composting materials in ASPS showed a rapid stabilization in pH value from the 4th week comparing to the speed in SW. Thermophilic stage for ASPS Lasted at 3 week whereas 6 weeks for WS. Required time to get thermophilic zone in compost was shorter in ASPS than in WS. Reduction rate in total carbon(T-C) was higher in ASPS than in WS. Organic matter was reduced more rapidly in ASPS than in SW showing 9 percent difference after the 6th week. Total nitrogen(T-N) increased while composting process, showing 9 percent after 6th week in WS and 1.8 percent after 7th week in ASPS. C/N ratio was stabilized after 6th week showing 17 and 21 level in WS and ASPS each. Quantity of ash and mineral content increased during composting in both system, showing higher content in ASPS. Composting process by intermittent, aerated static pile system in greenhouse had a significant effect on the reduction of required period for composting.

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A Study on the Apparel Industry and the Clothing Culture of North Korea (북한(北韓)의 의류산업(衣類産業)과 의생활문화(衣生活文化) 연구(硏究))

  • Cho, Kyu-Hwa
    • Journal of Fashion Business
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    • v.5 no.4
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    • pp.158-175
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    • 2001
  • The purpose of this study was to understand and improve the clothing habits and the apparel industry of North Korea in preparation for the reunification of South and North Korea. For this study, literary data, reports, periodicals, interviews and internet data of the two Koreas were reviewed. North Korean clothing habits used to be monotonous and uniform but nowadays people's clothes have become somewhat brighter in color and more diverse in design than before. In particular, liberal and individual dressing habits appeared among the privileged classes. When taking part in national events, women have to wear the traditional Korean costume, Hanbok, while men wear business suits for formal wear. In general, men don't wear Hanbok. Students have to be in uniforms but blue jeans, T-shirts with English logos were popular among them reflecting their sensitivity and openness towards western cultures. The brides usually wear pink Hanboks and the bridegrooms wear black business suits for their wedding. North Koreans also wear Hanbok on national holidays like South Koreans. Clothing is the most important item in the trade of process commission between North and South Korea. Trading items are mid to low end men's clothing for the most part due to less emphasis on fashion in the North. The processing is indirect trade and composed of sample making and contracting, sending out materials and production, carrying in goods and setting accounts. To activate South-North trade, establishment of infrastructure, stabilization of shipping, reducing high costs of distribution, building direct communication system by setting up office in a neutral zone and simplifying procedures in applying for the South and North Korea Economic Cooperation Fund. On the other hand, clothing and textiles education is carried on at art colleges, light industries colleges and commercial colleges in Pyongyang. Clothing institutes which study Hanbok and Western clothes, are installed in each city and province. Graduates who majored in clothing and textiles are posted in institutes or apparel factories. Their job is designing, patternmaking and sewing for their customers. Most of them are women and in good state of economic conditions. The North Korean clothing industry has been the core national industry that has developed based on overseas demand form the mid 1980s. The standard is that of South Korea in the early 1980s. In 1999, trade of North Korean textile products with trade counterparts such as Japan and China was $1.3 million in exports and $1.27 in imports. Of this amount the export takes up 25.4% of the total exports in North Korea. However, fundamentally even in sectors that are irrelevant to politics such as the fashion clothing industry, trust between the South and North should be a prerequisite. Only through this can exchange between North and South and economic cooperation contribute towards the reunification.

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Impacts of wave and tidal forcing on 3D nearshore processes on natural beaches. Part II: Sediment transport

  • Bakhtyar, R.;Dastgheib, A.;Roelvink, D.;Barry, D.A.
    • Ocean Systems Engineering
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    • v.6 no.1
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    • pp.61-97
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    • 2016
  • This is the second of two papers on the 3D numerical modeling of nearshore hydro- and morphodynamics. In Part I, the focus was on surf and swash zone hydrodynamics in the cross-shore and longshore directions. Here, we consider nearshore processes with an emphasis on the effects of oceanic forcing and beach characteristics on sediment transport in the cross- and longshore directions, as well as on foreshore bathymetry changes. The Delft3D and XBeach models were used with four turbulence closures (viz., ${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES) to solve the 3D Navier-Stokes equations for incompressible flow as well as the beach morphology. The sediment transport module simulates both bed load and suspended load transport of non-cohesive sediments. Twenty sets of numerical experiments combining nine control parameters under a range of bed characteristics and incident wave and tidal conditions were simulated. For each case, the general morphological response in shore-normal and shore-parallel directions was presented. Numerical results showed that the ${\kappa}-{\varepsilon}$ and H-LES closure models yield similar results that are in better agreement with existing morphodynamic observations than the results of the other turbulence models. The simulations showed that wave forcing drives a sediment circulation pattern that results in bar and berm formation. However, together with wave forcing, tides modulate the predicted nearshore sediment dynamics. The combination of tides and wave action has a notable effect on longshore suspended sediment transport fluxes, relative to wave action alone. The model's ability to predict sediment transport under propagation of obliquely incident wave conditions underscores its potential for understanding the evolution of beach morphology at field scale. For example, the results of the model confirmed that the wave characteristics have a considerable effect on the cumulative erosion/deposition, cross-shore distribution of longshore sediment transport and transport rate across and along the beach face. In addition, for the same type of oceanic forcing, the beach morphology exhibits different erosive characteristics depending on grain size (e.g., foreshore profile evolution is erosive or accretive on fine or coarse sand beaches, respectively). Decreasing wave height increases the proportion of onshore to offshore fluxes, almost reaching a neutral net balance. The sediment movement increases with wave height, which is the dominant factor controlling the beach face shape.

The Occlusal Evaluation and Treatment Planning for Prosthodontic Full Mouth Rehabilitation (보철학적 교합 재구성을 위한 교합진단과 치료계획)

  • Lee, Seung-Kyu;Lee, Sung-Bok;Choi, Dae-Gyun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.16 no.2
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    • pp.149-159
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    • 2000
  • Occlusal disease is comparable to periodontitis in that it is generally not reversible. Occlusal disease, however, like periodontitis, often maintainable. It does itself to treatment and when restorative dentistry is utilized it becomes, in that sense, reversible. Moreover, a systematized and integrated approach will lead to a prognosis that is favorable and predictable. This approach facilitates development of optimum oral function, comfort, and esthetics, resulting in a satisfied patient. Such a systematized approach consists of four logical phase : (1) patient evaluation, (2) comprehensive analysis and treatment planning, (3) integrated and systematic reconstruction, and (4) postoperative maintenance. An integrated treatment plan is first developed on one set of diagnostic casts, properly mounted on a semiadjustable articulator using jaw relationship records. This is accomplished by using wax to make reconstructive modifications to the casts. These modified casts become the blueprint for planned occlusal changes and the fabrication of provisional restorations. The treatment goals are : (1) comfortably functioning temporomandibular joints and stomatognathic musculature, (2) adherence to the basic principle of occlusion advocated by Schuyler, (3) anterior guidance that is in harmony with the envelope of function, (4) restorations that will not violate the patient's neutral zone. This report shows the treatment procedures for a patient whose mandibular position has been altered due to posterior bite collapse. Migration of the maxillary anterior teeth had occurred, and the posterior occlusal contacts showed pathologic interference. Precise diagnosis using mounted casts was executed and prosthodontic reconstruction by the aid of an unconventional orthodontic correction on maxillary flaring was planned. An unconventional orthodontic correction can be accomplished by using preexisting natural teeth, which can be modified for use in active tooth movement or splinted together for orthodontic anchorage. This technique has an advantage over conventional fixed appliance orthodontic therapy because it can accomplish tooth movement concurrently with restorative and periodontal therapy. On occasion, minor tooth movement can be necessary to achieve the optimum occlusal scheme, crown form, and tooth position for the forces of occlusion to be displaced down the long axis of the periodontally compromised teeth. Once the occlusion, periodontal health, and crown contours for the provisional splinted restoration are acceptable, the final splinted restoration can be similarly fabricated, and it becomes an excellent orthodontic retainer.

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