• Title/Summary/Keyword: gap joint

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The evaluation for adhesion and compatibility properties of polyurethane and silicone sealant for window installation (창호 시공용 폴리우레탄 및 실리콘 실란트 접착성 및 상응성 평가)

  • Ahn, Myung-Su;Jung, Jin-young;Seo, YeonWon;Kim, Sung Hyun;Bae, Keesun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.75-77
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    • 2014
  • Using sealant for window installation is sealing the gap between the window frame and outer wall (such as concrete). A sealant serves to prevent external environmental impacts such as moisture, rain, sand, and dust entering inside of the building and make the building durable. In order to fulfill basic jointing function of sealing, at least 6 mm joint gap between two bonding surfaces are required. Also, adhesion performance between sealant and surfaces and the compatibility with other building materials are required to check before installation. In general, 2 part polyurethane sealant and 1 part silicone sealant are most common materials for sealing the joint of window. In this study, adhesion performances of those two generic sealants reflecting actual application conditions and the compatibility evaluations with other building materials are conducted to propose proper window installation procedures.

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Acromioclavicular joint dislocation and concomitant labral lesions: a systematic review

  • Jad Mansour;Joseph E Nassar;Michel Estephan;Karl Boulos;Mohammad Daher
    • Clinics in Shoulder and Elbow
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    • v.27 no.2
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    • pp.247-253
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    • 2024
  • Acromioclavicular (AC) joint dislocations frequently co-occur with intra-articular glenohumeral pathologies. Few comprehensive studies have focused on labral tears specifically associated with AC joint trauma. This systematic review will address this gap. A comprehensive electronic search was conducted across PubMed, Cochrane Library, and Google Scholar (pages 1-20) spanning from 1976 to May 19, 2023. Seven studies met the inclusion criteria for this systematic review, consisting of three retrospective studies and four case series. These studies collectively involved 1,044 patients, of whom 282 had concomitant labral lesions. The pooled prevalence of intra-articular labral injuries associated with acute AC joint dislocation was 27%. The prevalence of these labral lesions varied significantly between studies, ranging from 13.9% to 84.0% of patients, depending on the study and the grade of AC joint dislocation. Various types of labral tears were reported, with superior labrum anterior to posterior (SLAP) lesions being the most common. The prevalence of SLAP lesions ranged from 7.2% to 77.4%, with higher grades of AC joint dislocations often associated with a higher prevalence of SLAP tears. Moreover, grade V dislocations exhibited a complete correlation with SLAP tears. The studies yielded contradictory findings regarding older age and higher grades of AC joint dislocation as risk factors for concurrent labral lesions. This review underscores the frequent association between labral lesions and AC joint dislocations, particularly in cases of lower-grade injuries. Notably, SLAP lesions emerged as the predominant type of labral tear.

Study on the Process Parameters for Laser Welding of Coaxial Circular Pipe Inner Flange (동축 파이프 이음부의 레이저용접 공정변수에 관한 연구)

  • Kim, Yong;Park, Ki-Young;Lee, Kyoung-Don
    • Laser Solutions
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    • v.12 no.3
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    • pp.14-17
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    • 2009
  • The laser welding was performed for the flange joint of two overlapped coaxial circular pipes which serve as the inlet and connector pipes of STS 316L. The laser welding test finally resulted in a good penetration depth of 1.8 to 2.0 mm. On the way to get the good welding quality, two important parameters were found to be optimized. One is the focal positioning which is the offset of the laser beam focus to the exact welding seam line, which is more critical in the inner flange laser welding. When the beam spot size was deviated more than $200\;{\mu}m$ from the seam line, welding of two pipes is failed. The other is a gap size since a certain amount of gap is inevitable due to fabrication tolerance, or artificial allowances for smooth insertion of a pipe. However, it is required to restrict the gap allowance within 0.2mm to avoid undesirable undercut on a welding bead.

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Determination of Optimum Blank Shape to Minimize the Root Gap during TIG Welding in Hot Curvature Forming of Al5083 Thick Plate (열간 곡면성형된 Al5083 후판의 TIG 용접 시 루트갭 최소화를 위한 최적 블랭크 형상 결정)

  • Lee, Jeong Min;Ko, Dae Hoon;Lee, Kyung Hun;Lee, Chan Joo;Kim, Byung Min
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.8
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    • pp.815-823
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    • 2013
  • The hot curvature forming of large aluminum plates is a process used to produce spherical liquefied natural gas (LNG) tanks. In this study, we describe a method to determine the optimum shape of blanks to minimize the root gap in the forming process. The method proposed in this study was applied to a small-scale model for thick plates with a curvature of 1500 mm and thickness of 6 mm. First, the shape of the curved shells was determined as the target shape, and then a coordinate transform was used to determine the optimum blank shape, which was then iteratively modified using the results of finite element method (FEM) simulations, including heat transfer, until the shape error was minimized. Experiments in forming using Al5083 thick plate were carried out, showing that the method can determine the optimum blank shape within an allowable root gap of 0.1 mm.

Morphological and Biomechanical Study of the Pulley System of the Thumb

  • Kim, Ji-Won
    • Physical Therapy Korea
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    • v.12 no.4
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    • pp.33-40
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    • 2005
  • The purpose of this study was to define more precisely the anatomy of the thumb flexor pulley system and to determine the relative contribution of each of the pulleys to the biomechanics of thumb motion at the metacarpophalangeal (MP) and interphalangeal (IP) joints. For this, 22 hands from 11 cadavers were used and randomly assigned to two groups. In the first group, the first annular (A1) pulley was cut first followed by the variable annular (Av) pulley and then the oblique pulley. In the second group, the oblique pulley was cut first followed by the, pulley and then the Av pulley. In 7 of 22 hands, it was a transverse structure parallel to the, pulley with a gap between the A1 and Av pulleys, referred to here as type I. In 9 hands, the A1 and Av pulleys were connected without any gap (type II). In 6 hands, the space between the A1 and Av pulleys were triangular in shape with fibers of the Av pulley converging toward the radial side (type III). In biomechanical study of both first and second experiments, there was no significant difference in MCP joint flexion between the all intact, A1 section, A1/Av section, A2 intact (A1/Av/oblique section), and no pulley configuration (p>.05). In occurring displacements less than 10 mm, there was no significant difference in IP joint flexion (p>.05). However, there was a significant decrease in IP joint flexion occurred in both 15 mm and 20 mm excursion (p<.05), when the oblique pulley was resected additionally after cutting the A1 and Av pulleys in first experiment, and when the A1 pulley was resected additionally after cutting the oblique pulley. According to the results, the injury of only the oblique pulley does not decrease thumb motion significantly. The oblique pulley injury with both the A1 and Av pulleys laceration decreased thumb motion significantly. The additional laceration of the A2 pulley does not decrease thumb motion.

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Current Research on the Stress Analysis of Artificial Knee Joint (인공 슬관절의 응력 해석에 관한 연구)

  • Lee Jae-Hwan
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.240-245
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    • 2005
  • In this paper, the current research for the biomechanics of artificial knee joints including experiments and stress analysis is surveyed and Introduced. The knee joint is the most large and the motion is very complicated, so the design of artificial joint is difficult and most research Is being done abroad. Up to date, most products are foreign products and Imported here and the gap between here and advanced countries of the technical and capability for the design and manufacturing is too deep to follow. So, the contents of papers in this area including the most excellent results are introduced. And the preliminary research on the contact stress analysis of the joints is present.

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The Application of 3-dimensional Surface Imaging to the Early Detection of Sacroiliitis (3차원 영상기법을 이용한 천장골염의 조기 진단)

  • Jeon, Jae-Han;Kim, Seon-Il;Lee, Du-Su
    • Journal of Biomedical Engineering Research
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    • v.14 no.3
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    • pp.235-242
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    • 1993
  • In the early stage of sacroilitis, it is'difficult to detect sacroiliac(Sl) abnormalities by conventional plain X-ray even though there are characteristic symptoms of ankylosing spondylitis. 3 dimensional volume rendering from the CT image was performed to make an early de tection of the structural changes of Sl joint. 2 cases who had clinical impression of ankylosing spondylitis without sacroilitis in plane X-ray and 1 case of typical ankylosing spondylitis as well as 1 case of normal control were studied. The Sl Joints were separated and each joint surface of sacrum and ilium was independently reconstructed by a special 3D manipulation program. All 2 patiant who complained of inflammatory lower back pain with no abnormal findings in the plain X-ray showed structural changes in 3 dimensionally reconstructed surface Image of the Sl joint compared to the normal control. Authors tried several parameters, such as fourler analysis of each surface and the mean and variance of Sl joint gap. We couldn't tell the statistical significance because of the limited number of cases. However, the parameters showed difference according to the progression of disease.

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Development of Joint Sales Business by Regional Agricultural Cooperatives in a Major Apple Production Region of Korea - Focused on the Case of Muju County, North Jeolla Province - (한국 사과 주산지의 지역농협 연합판매사업의 전개 - 전라북도 무주군을 사례로 -)

  • Hwang, Sung-il;Sakashita, Akihiko
    • Korean Journal of Organic Agriculture
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    • v.30 no.3
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    • pp.313-333
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    • 2022
  • In Muju County, one of Korea's major apple producers, the regional agricultural cooperatives united together and invested to establish a cooperative joint business corporation in charge of the sales business. The corporation carried out the sales business transferred from the participating regional agricultural cooperatives. While the two participating cooperatives showed a marked difference in the degree of participation at the beginning of the business, the introduction of the agricultural product processing centers (APCs) and the participation of co-selection and shipment organizations and general farms helped settle this gap. In addition, commercialization through the APCs enhanced the market competitiveness of apples, which led to the stable securing of sales outlets. The corporation integrated the sales business in the county and this resulted in increased sales volume and sales revenue. Playing a leading role in introducing and cultivating new crops on a trial basis, the corporation demonstrated its potential as the main body of the joint sales business.

Effect of flexion degrees in elbow joint on muscle activation of the extensor carpi radialis and biceps brachii muscles in healthy young adults

  • Kim, Gap-Cheol;Hwang, Sujin
    • Physical Therapy Rehabilitation Science
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    • v.5 no.3
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    • pp.120-124
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    • 2016
  • Objective: Chronic lateral epicondylitis is a condition which becomes sore and tender on the lateral side of the elbow joint damaged from overuse and repetitive use of the extensor muscles of the forearm. The purpose of this study was to investigate the effects of flexion degrees in the elbow joint on extensor carpi radialis longus and brevis and biceps brachii muscles in individuals with healthy young adults. The main purpose of this study was to suggest the feasibility of optimal elbow angle during therapeutic eccentric exercise with resistance for strengthening of wrist extensors. Design: Cross-sectional study. Methods: Thirty health young adults (male 15, female 15) participated in this study. This study measured muscle activation in four different conditions of elbow flexion, $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$ during eccentric exercise with weight loading in wrist extensors, extensor carpi radialis longus and brevis and biceps brachii muscles using surface electromyography. Results: The muscle activation of extensor carpi radialis showed a negative relationship with the degrees of elbow joint flexion. With increasing elbow flexion angles, the ECRL muscle activation amount was significantly lower (p<0.05). In contrast, the muscle activation of the ECRB muscle activation amount was significanlty higher (p<0.05). Conclusions: This study suggests that the eccentric exercise of wrist extension with selected activation of wrist extensor muscles according to elbow flexion positions, and suggests that the extensor carpi radialis longus and brevis will need to be strengthened for preventing and treating chronic lateral epicondylitis regardless of degrees of elbow joint flexion.

Deformation Characteristics of Construction Joint of Paved Track on Earthwork Section using the Accelerated Track Test (궤도가속실험을 통한 포장궤도 토공구간 시공이음매부의 변형특성 연구)

  • Lee, Il-Wha;Jang, Seung-Yup;Kang, Yoon-Suk;Um, Ju-Hwan;Kim, Eun
    • Journal of the Korean Society for Railway
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    • v.13 no.5
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    • pp.521-527
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    • 2010
  • The Paved Track is applied to reduce maintenance cost of conventional line. The Paved Track could be used in all types of lines including earthwork, bridge, tunnel and turnout sections. In case of earthwork section, the construction joint is the most critical factor to track durability. The construction joint does not affect to the track structure directly, but the gap due to discontinuity of slabs may affect to the long-term serviceability. To evaluate this problem, the accelerated track test has been performed on the construction joint and the middle part to of the real scale Paved Track. The purpose of this test is that evaluate the vulnerability of construction joint section comparing the trends of settlement and earth pressure under repeated loads of construction joint with those of the middle slab part.