• Title/Summary/Keyword: End Bearing

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Strength of Compression Lap Splice in Confined Concrete (횡구속된 콘크리트에서 압축이음강도)

  • Chun, Sung-Chul;Lee, Sung-Ho;Oh, Bo-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.855-858
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    • 2008
  • A compression lap splice can be calculated longer than a tension lap splice in high strength concrete according to current design codes. Including effects of transverse reinforcement, a compression splice becomes much longer than a tension splice. Effects of transverse reinforcement on strength and behavior of compression lap splice, which always exist in actual structures, have been investigated through experimental study of column tests with concrete strength of 40 and 60 MPa. Confined specimens have twice of calculated strengths by current design codes. New design equations for the compression lap splice including the effects of transverse reinforcement are required for practical purpose of ultra-high strength concrete. End bearing is enhanced by transverse reinforcement placed at ends of splice not by transverse reinforcement within splice length. As more transverse reinforcement are placed, the stresses developed by bond linearly increase. The transverse reinforcements at ends of splice a little improve the strength by bond.

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Systemic Review of Hyaluronate for the Treatment of Osteoarthritis (골관절염 치료제 히알우론산 임상연구결과의 Systemic Review)

  • Bang, Joon-Seok
    • Korean Journal of Clinical Pharmacy
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    • v.17 no.1
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    • pp.38-45
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    • 2007
  • Background: The multitude of the therapeutic usefulness of intra-articular injection of hyaluronate on oateoarthritis of the knee is still in question. The objective of this systemic review was to elucidate both the therapeutic efficacy and the safety of intra-articular administration of hyaluronic acid for degenerative osteoarthritis of the knee joints. Methods: I searched MEDLINE and Korea Medical Database (KMbase) from January 1990 to April 2007 using a combination search terms for knee osteoarthritis and hyaluronic acid and a filter for randomized controlled trials. I extracted data on pain at rest, and during or just after movement, on joint function, and on adverse events. Results: Ten trials that reported usable quantitative information on any of the predefined end points were identified and included in the systemic review. Intra-articular injection of hyaluronic acid can decrease symptoms of osteoarthritis of the knee. The study revealed significant improvements in pain and functional outcomes with few adverse effects. However, there was significant between-study heterogeneity in the estimates of the efficacy of hyaluronic acid. Sub-group analysis showed that lower methodological quality such as a single-blind or single-center design resulted in higher estimates hyaluronic acid efficacy, and that patients older than sixty years of age and those with the most advanced radiographic stage of osteoarthritis were less likely to benefit from intra-articular injection of hyaluronic acid. Conclusion: According to the currently available evidence, intra-articular hyaluronic acid has been proven clinically effective for the patients bearing the knee osteoarthritis with NSAID-induced GI troubles or inapplicable to any surgery, and may be associated with lower risk of adverse events.

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Artyfechinostomum malayanum: Metacercariae Encysted in Pila sp. Snails Purchased from Phnom Penh, Cambodia

  • Sohn, Woon-Mok;Yong, Tai-Soon;Eom, Keeseon S.;Sinuon, Muth;Jeoung, Hoo-Gn;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • v.55 no.3
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    • pp.341-345
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    • 2017
  • The metacercariae of Artyfechinostomum malayanum (Leiper, 1911) Mendheim, 1943 were discovered in Pila sp. snails purchased from a market in Phnom Penh, Cambodia. They were isolated from the snails using the artificial digestion technique and were orally fed to 2 hamsters, 1 rat, and 2 mice to obtain the adult flukes. The metacercariae were round, $145-165{\mu}m$ in diameter, having a cyst wall of $6-10{\mu}m$ in thickness, a head collar and collar spines, and characteristic features of excretory granules. Adult flukes were recovered in the small intestines of the animals at days 14 and 32 post infection and were morphologically observed using a light microscope and a scanning electron microscope. They were plump or elongated, ventrally curved, $6.0-8.1{\times}1.6-2.0mm$ in size, and characterized by the head collar bearing 43 collar spines, including 5 end group ones on each side, a long cirrus sac extending beyond the posterior margin of the ventral sucker, a submedian ovary, and 2 deeply lobed testes. Eggs in uteri were operculate, ovoid to ellipsoid, and $120-135{\times}68-75{\mu}m$ in size. In scanning electron microscopy, the head collar was prominent with collar spines looking like horns. Scale-like tegumental spines were densely distributed on the ventral surface between the head collar and ventral sucker. Sensory papillae were distributed mainly on the tegument around suckers. By this study, it has been first confirmed that the life cycle of A. malayanum exists in Cambodia.

Equivalent Linear Stiffness Matrix of Pile Foundation for the Seismic Response Analysis of Bridges (교량의 지진응답해석을 위한 말뚝기초의 등가 선형 강도행렬)

  • 박형기;조양희
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.3
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    • pp.1-8
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    • 2001
  • Seismic design forces for bridge components may be determined by modifying elastic member forces of design earthquakes using appropriate response modification factors according to the national design code of bridges Modeling technique of pile foundation system is one of the important parameters which greatly affects the results in the process of the elastic seismic analysis of a bridge system with pile foundation. In this paper, a approximate and simplified modeling technique of a pile foundation system for the practical purposes is presented. The modeling technique is based on the stiffnesses of pile foundation during earthquake. The horizontal stiffnesses are determined from the resistance-deflection curves derived from the results of dynamic field tests using cyclic loads and the vertical stiffness includes the effects of the end bearing capacities and side friction of piles as well as the pile compliances under the expected vertical load level. The applicability of the proposed technique has been validated through the some example bridge analyses.

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Echinostoma macrorchis (Digenea: Echinostomatidae): Metacercariae in Cipangopaludina chinensis malleata Snails and Adults from Experimental Rats in Korea

  • Sohn, Woon-Mok;Na, Byoung-Kuk
    • Parasites, Hosts and Diseases
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    • v.55 no.5
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    • pp.541-548
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    • 2017
  • A survey was performed to know the infection status of echinostome metacercariae in Cipangopaludina chinensis malleata snails from Korea. Total 75 snails collected in 5 localities, i.e., Imsil-gun, Jeollabuk-do, Hwasun-gun and Shinan-gun (Aphae and Jido), Jeollanam-do, and Jinju-si, Gyeongsangnam-do, were examined for metacercariae by the artificial digestion method. Infection rates of metacercariae were 80.0%, 66.7%, 100%, 60.0%, and 73.3%, and their densities were 39, 32, 183, 19, and 30 per snail infected, respectively. The metacercariae were round, $105-118{\times}105-118{\mu}m$ in size, with a thin cyst wall, collar spines on the head collar, and excretory granules in 2 canals of excretory tube. Adult flukes were elongated, ventrally curved, and $5,167{\times}939{\mu}m$ in average size. Head collar distinct, bearing 45 collar spines with 5 end groups on each side. Oral sucker subterminal, pharynx well developed, and esophagus somewhat short. Cirrus sac well developed, with a saccular seminal vesicle, and ventral sucker very large. Ovary elliptical and on the median line of the body. Testes tandem and slightly lobed. Eggs operculated, elliptical, and $90-103{\times}55-60{\mu}m$ in size. By scanning electron microscopy, the head collar was prominent with 45 collar spines resembling horns of younger stags. Scale-like tegumental spines were densely distributed on the body surface between the head collar and ventral sucker. Conclusively, it has been first confirmed that the life cycle of E. macrorchis is indigenously maintained in Korea, and C. chinensis malleata snails are popularly infected with the metacercariae of this echinostome.

Moment Resistance Performance of Each Joint for Post-Beam Frame Structure (기둥-보 뼈대구조를 위한 각부 접합부의 모멘트저항성능)

  • Park, Joo-Saeng;Hwang, Kweon-Hwan
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.1
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    • pp.8-14
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    • 2011
  • Japanese larch glulam was used as structural members to develop a modern engineered wood jointing system using traditional post and beam structure. For the connections comprised of traditional joining and drift-pins, structural members are processed at a pre-cut factory. As a basic study to examine and increase the whole shear performance of portal frame, pin withdrawal test and moment resistance tests were conducted on each connection. The post and beam members with specified connectors showed good bearing performance in the wood members' joining system, column-base and beam-end. Moment rigidity was a bit better in a joint with higher slenderness ratio of drift-pin, but moment resistance performances, yield moment and maximum moment, were excellent in smaller one.

Lateral Arm Free Flap for Small Sized Diabetic Foot Ulcer around Toes (족지 주위의 작은 크기의 당뇨 족부 궤양에 대한 외측 상완 유리 피판술)

  • Jung, Heun-Guyn;So, Gwang-Young;Kuk, Woo-Jong;Kim, Hee-Dong
    • Archives of Reconstructive Microsurgery
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    • v.17 no.1
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    • pp.28-35
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    • 2008
  • The purpose of this study was to present the clinical analysis of the results of lateral arm free flap for small sized and infected diabetic foot ulcer around toes. From May 2006 to December 2007, Seven patients were included in our study. Average age was 52.8 years, six were males and one was female. All had infected diabetic foot ulcer and had exposures of bone or tendon structures. Ulcers were located around great toe in four patients, 4th toe in one and 5th toe in two. Three patients had osteomyelitis of metatarsal or phalanx. After appropriate control of infection by serial wound debridement and intravenous antibiotics, lateral arm flap was applied to cover remained soft tissue defects. Posterior radial collateral artery of lateral arm flap was reanastomosed to dorsalis pedis artery of recipient foot by end to side technique in all cases in order to preserve already compromised artery of diabetic foot. All flaps were designed over lateral epicondyle to get longer pedicle and averaged pedicle length was 8 cm. Two cases were used as a sensate flap to achieve protective sensation of foot. All flaps survived and provided satisfactory coverage of soft tissue defects on diabetc foot ulcers. All patients could achieve full weight-bearing ambulation. No patients has had recurrence of infection, ulceration and further toe amputations. There were three complications, a delayed wound healing of flap with surrounding tissue, a partial peripheral loss of flap and a numbness of forearm below donor site. All patients were satisfied with their clinical results, especially preserving their toes and could return to the previous activity levels. Lateral arm free flap could be recommend for infected diabetic foot ulcers around toes, to preserve toes, coverage of soft tissue defect and control of infection with low donor site morbidity.

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Through Knee Amputation: Technique Modifications and Surgical Outcomes

  • Albino, Frank P.;Seidel, Rachel;Brown, Benjamin J.;Crone, Charles G.;Attinger, Christopher E.
    • Archives of Plastic Surgery
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    • v.41 no.5
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    • pp.562-570
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    • 2014
  • Background Knee disarticulations (KD) are most commonly employed following trauma or tumor resection but represent less than 2% of all lower extremity amputations performed in the United States annually. KDs provide enhanced proprioception, a long lever arm, preservation of adductor muscle insertion, decreased metabolic cost of ambulation, and an end weight-bearing stump. The role for KDs in the setting of arterial insufficiency or overwhelming infection is less clear. The purpose of this study is to describe technique modifications and report surgical outcomes following KDs at a high-volume Limb Salvage Center. Methods A retrospective study of medical records for all patients who underwent a through-knee amputation performed by the senior author (C.E.A.) between 2004 and 2012 was completed. Medical records were reviewed to collect demographic, operative, and postoperative information for each of the patients identified. Results Between 2004 and 2012, 46 through-knee amputations for 41 patients were performed. The mean patient age was 68 and indications for surgery included infection (56%), arterial thrombosis (35%), and trauma (9%). Postoperative complications included superficial cellulitis (13%), soft tissue infection (4%), and flap ischemia (4%) necessitating one case of surgical debridement (4%) and four transfemoral amputations (9%). 9 (22%) patients went on to ambulate. Postoperative ambulation was greatest in the traumatic cohort and for patients less than 50 years of age, P<0.05. Alternatively, diabetes mellitus and infection reduced the likelihood of postoperative ambulation, P<0.01. Conclusions Knee disarticulations are a safe and effective alternative to other lower extremity amputations when clinically feasible. For patient unlikely to ambulate, a through-knee amputation maximizes ease of transfers, promotes mobility by providing a counterbalance, and eliminates the potential for knee flexion contracture with subsequent skin breakdown.

Mesh selectivity of gill net for swimming crab Potunus trituberculatus in the western coastal waters of Korea (서해 꽃게 자망의 망목 선택성 연구)

  • Park, Chang-Doo;Cho, Sam-Kwang;Kim, Hyun-Young;Park, Seong-Wook
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.2
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    • pp.106-115
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    • 2013
  • A series of fishing experiments were carried out in the western coastal waters of Korea from May, 2006 to September, 2007, using gill nets of different mesh sizes (m=101, 121.8, 152.5, 176.8, and 191 mm) to determine the mesh selectivity of gill net for swimming crab, Potunus trituberculatus. The catch species was composed of swimming crab (87%), Thomas's rapa whelk Rapana venosa (5%), arthritic neptune Neptunea cumingi (2%), Japanese swimming crab Charybdis japonica (2%), marbled sole Pleuronectes yokohamae (1%), pen shell Atrina pectinata, ocellate spot skate Okamejei kenojei, and so on. The carapace length (CL) of each swimming crab caught in the experimental nets was measured. Sponge crab (egg-bearing female crab) was appeared from the end of June to August in the coastal waters. The master selection curve was estimated by applying the extended Kitahara's method. The selection curve showed that the gill nets of larger mesh size allowed more crabs of small carapace size to escape. The optimum value (CL/m) was 0.645 and the CL/m was estimated to be 0.301, 0.354, 0.391, 0.422, and 0.450 when the retention probabilities were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

Pullout Behavior Characteristics of Enlarged Cylinder Type Anchor Using Numerical Analysis (수치해석을 이용한 확공형 앵커의 인발거동 특성)

  • Moon, Joon-Shik;Lee, Min-Joo
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.113-118
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    • 2017
  • Numerical analysis was carried out using a finite element analysis program to analyze the behavior characteristics of enlarged cylinder type anchor. It was found that the ultimate resistance of enlarged cylinder type anchor increases with the enlargement angle from numerical analysis for various enlargement angle cases. In the case of $30-60^{\circ}$ of enlargement angle, the deformation and stress distribution characteristics in anchor are similar regardless of enlargement angle. However, when the same tensile force is applied, there is a difference in the degree of frictional resistance because of difference of displacement of top of grouting zone. Also, it was found that the maximum compressive force and tensile force were generated at the cone of the upper portion of the grouting zone, and tensile fracture of the upper grouting portion is likely to occur.