• Steel and Composite Structures
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• v.18 no.5
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• pp.1305-1330
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• 2015

The successful application of the component-based approach - widely used to model structural joints - requires knowledge of the mechanical properties of the constitutive joint components, including an appropriate assembly procedure to derive the joint properties. This paper presents a component-method model for a structural joint component that is located in the tension zone of blind-bolted connections to concrete-filled tubular steel profiles. The model relates to the response of blind-bolts with headed anchors under monotonic loading, and the blind-bolt is termed the "Extended Hollo-bolt". Experimental data is used to develop the model, with the data being collected in a manner such that constitutive models were characterised for the principal elements which contribute to the global deformability of the connector. The model, based on a system of spring elements, incorporates pre-load and deformation from various parts of the blind-bolt: (i) the internal bolt elongation; (ii) the connector's expanding sleeves element; and (iii) the connector's mechanical anchorage element. The characteristics of these elements are determined on the basis of piecewise functions, accounting for basic geometrical and mechanical properties such as the strength of the concrete applied to the tube, the connection clamping length, and the size and class of the blind-bolt's internal bolt. An assembly process is then detailed to establish the model for the elastic and inelastic behaviour of the component. Comparisons of model predictions with experimental data show that the proposed model can predict with sufficient accuracy the response of the component. The model furthers the development of a full and detailed design method for an original connection technology.

• Journal of Korean Foot and Ankle Society
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• v.21 no.4
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• pp.151-155
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• 2017

Purpose: Reducing tenderness or pain on the ankle joint and improving the range of motion are thought to be possible using hyaluronate-based anti-adhesive agents. On the other hand, there are more aspects to be studied regarding the incidence of complications, such as resting pain, tenderness, and stiffness, after surgery. Therefore, the aim of this study was to prove the effectiveness of the agents after ankle fracture surgery. Materials and Methods: Patients, who underwent open reduction and internal fixation surgery due to ankle joint fractures from June 2015 to May 2016, were studied prospectively. Thirty patients of them received a $Guardix^{(R)}$ injection during their surgeries and were included in the injection group. The other 30 patients were included in the control group. Postoperatively, tenderness on the scar, a delay in wound healing, and the active range of motion were evaluated at 2, 6, and 12 weeks after surgery. Results: A significant difference in tenderness on the scar was observed 2 weeks after surgery. On the other hand, there was no significant difference at 6 and 12 weeks after the surgery. The agent-using group showed a 6.7% delay in wound healing and a 93.3% nondelaying. In the non-using group, the delay was 63.3%, while non-delay was 36.7% (p<0.001). The group that underwent $Guardix^{(R)}$ usage showed an effective result in the visual analogue scale, which was statistically significant (p<0.001). The result at 6 and 12 weeks after surgery showed a significant difference. Conclusion: Improvement was observed in the patients who underwent a $Guardix^{(R)}$ injection, regarding the range of motion, visual analog scale, and healing of the wound postoperatively.

• International Journal of High-Rise Buildings
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• v.9 no.2
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• pp.155-166
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• 2020

To connect exterior reinforced concrete (RC) columns with the steel belt truss, the gusset plates are welded to the steel plates embedded in the RC column. Then, the concrete around an embedded plate is very likely to be damaged by the heat input from a long-time (6 to 48 hours) welding of the embedded and gusset plates at a joint between RC columns and steel belt truss. However, very few studies have assessed the concrete damage caused by the welding heat between embedded and gusset plates, and no clear onsite solution has been found. In this paper, experimental tests have been carried out on 4 full-scale specimen to analyze the effect of long-time (about 6 hours) onsite welding (1-side welding and 3-side welding) between a gusset plate and an embedded plate in high strength concrete with compressive strength of 55 MPa and 80 MPa on RC columns. The effect of the long-time welding heat of embedded and gusset plates, which are used in real high-rise building construction sites, on concrete is analyzed in terms of the following three items: 1) temperature distribution, 2) pattern and characteristics of cracks, and 3) effect of the cracks on the compressive strength of RC column. Based on the experimental results, even though the heat input up to about 150? from the long-time onsite welding on the high-strength concrete column for the joint could result in concrete cracks in a radial form, it is found that the welding cracks have no effect on the axial stiffness and strength of the concrete column.

• Archives of Plastic Surgery
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• v.39 no.2
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• pp.130-136
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• 2012

Background : Complex elbow injuries with associated nerve, muscle, or joint injury commonly develop post-inury stiffness. In order to preserve function, joint congruency, elbow stability and durable wound coverage must be achieved in a timely manner. Methods : A retrospective review of patients who underwent orthopaedic fixation followed by free anterolateral thigh (ALT) flap soft tissue coverage was performed. Five patients were identified and included in this study. Results : We present a series of 5 cases managed with this principle. Soft tissue defects ranged in size from $4{\times}9cm$ ($36cm^2$) to $15{\times}30cm$ ($450cm^2$) and were located either posteriorly (n=4) or anteriorly (n=1). Associated injuries included open fractures (n=3) and motor nerve transection (n=2). Wound coverage was achieved in a mean duration of 18.8 days (range, 11 to 42 day). There were no flap failures and no major complications. The mean postoperative active elbow motion was $102^{\circ}$ (range, $45^{\circ}$ to $140^{\circ}$). Conclusions : In our small series we have highlighted the safety and utility of using the free ALT flap in complex elbow injuries. The ALT flap has many advantages which include abundant skin and subcutaneous tissue; vascularised vastus lateralis muscle that was used in our series to obliterate dead space, provide a vascular bed for nerve grafts and combat infection; and, access to fascia lata grafts for reconstruction of the triceps tendon.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.305-311
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• 2018

Osteoarthritis (OA) is the most common form of joint disease, characterized by articular cartilage, osteonecrosis, and osteochondral bone erosion. It is an early, progressive disease that combines joint stiffness and joint pain and reduces cartilage function and condition. Interleukin-1 beta ($IL-1{\beta}$) is thought to be important to the pathogenesis of OA and significantly increases the expression of matrix metalloproteinases (MMPs), which play an important role in cartilage degradation in OA. Sparassis crispa (Wulf.) is an edible / medicinal mushroom that has been reported to variety of biological activities. In this study, investigated the Anti-inflammatory effect of Sparassis crispa (Wulf.) ethanol extract (SCE) on $IL-1{\beta}$ stimulated SW1353 chondrocytes. SCE decreased the expression and activity of MMPs by $IL-1{\beta}$ and decreased the levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) associated with the inhibition of prostaglandin E2($PGE_2$) in $IL-1{\beta}$ stimulated SW-1353 chondrocytes. In addition, SCE inhibits the expression of MAPK (mitogen-activated protein kinase) and $NF-{\kappa}B$ (nuclear factor-kappa B) signaling in $IL-1{\beta}$ stimulated SW-1353 cells, and SCE inhibits the production of reactive oxygen species (ROS) through heme oxygenase-1 (HO-1) expression. Thus, it is suggested that SCE has a potential as an anti-inflammatory agent in osteoarthritis treatments.

• Steel and Composite Structures
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• v.16 no.4
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• pp.417-436
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• 2014

During an earthquake, steel frame columns can be subjected to high axial forces combined with inelastic rotation demand resulting from story drift. Generally, the whole beam or component can be represented with one element. In elasto-plastic analysis, subdivision is necessary if the plastic deformation occurs within two ends of beams. If effects of the joint panel are necessarily considered in the analysis, the joint panel should be represented with an independent element. It is a special element to represent the shear deformation of the joint panel in the beam-column connection zone. Several analytical models for panel zone (PZ) behavior exist, in terms of shear force-shear distortion relationships. Among these models, the Krawinkler PZ model is the most popular one which is used in the AISC code. Some studies have pointed out that Krawinkler's model gives good results for the range of thin to medium column flanges thickness. This paper, introduces a new model to estimate the response of shear force-shear distortion for the PZ including column axial force. The model is applicable to both thin and thick column flange. To achieve an appropriate PZ mathematical model first, the effects of PZ strength and stiffness on connection response are parametrically studied using finite element models. More than one thousand and four-hundred beam-column connections are included in the parametric study, with varied parameters; then based on analytical results a simple mathematical model is presented. A comparison between the results of proposed method herein with FE analyses shows the average error especially in thick column flange is significantly reduced which demonstrates the accuracy, efficiency, and simplicity of the proposed model.

• Journal of Korean Society of Steel Construction
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• v.23 no.2
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• pp.169-177
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• 2011

This paper presents the results of the systematic finite element analysis of the in-plane bending moment of T-joints subjected to cyclic loadings. T-joints were fabricated using high-strength, circular, hollow sections. Three-dimensional, nonlinear finite element models of the welded T-joints were constructed to investigate the strength, rotational-stiffness characteristics, and failure modes. A wide scope of structural behaviors explain the influence of the joint geometric parameters, such as the chord and brace wall slenderness ratios and the ratio of the brace to the chord diameter, as well as the yield strength ratios and compressive-chord-stress effects on the ultimate in-plane bending moment capacity of the T-joint.

• Journal of Korean Association for Spatial Structures
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• v.8 no.1
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• pp.89-97
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• 2008

The object of this paper is to evaluate on behavior the experimentally of beam-to-column joints for modular steel frame with the hollow structural steel section to LEB C-shape. Beam-to-column joints carried out test on the joint shape bracket-type and welded-type to consideration which the joints for modular steel frame was capacity, deformation and failure mode. Test of results, the beam-column joints decided to the lateral buckling strength in LEB C-shape regardless of joint-shape and joint failure. The strength & stiffness for joints increase as the bracket-thickness. The results from theory of lateral buckling are compared to the experimental results. The ratio of experimental results to theory value is $0.83{\sim}0.95$ in the case of bracket-type and welded-type of $0.87{\sim}0.9$, indicating an accurate and safe estimation.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.505-517
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• 2004

This paper presented equations on the stress evaluation of steel frame pier connections that were composed of a box beam and a circular column. The existing equations, which transformed the circular column into an equivalent box column had some problems; they underestimated a shear lag stress as the joint angle decreased, and overestimated a shear stress as the joint angel increased. Therefore, FE analyses were performed with various parameters, such as joint angle(${\alpha}$), span length-width ratio(L/B), and circular column-to-box beam stiffness ratio(${\alpha}$), and new equations on stress evaluation were proposed based on FE analyses. Furthermore, material and geometric nonlinear analyses were performed to estimate ultimate strength and to confirm the validity of the proposed equations.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.237-243
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• 2006

The aims of this study was to investigate the clinical and radiographic features of temporomandibular dysfunction in the patients with RA to elucidate whether the RA patients would be a risk group for TMD. The 35 patients with temporomandibular joint dysfunction were included for this study, of which 15 had rheumatoid arthritis diagnosed by a rheumatologist, and other 20 was control group and they didn't have any history or clinical signs related to it. Clinical symptoms and signs of temporomandibular joint disorders, radiographic and MRI findings of temporomandibular joint were investigated. The results were compared between two groups. In RA group bilateral pain, morning stiffness, reduced opening range, and crepitations were more frequently reported than control group. Radiologic findings such as sclerosis and flattening of condylar head, marginal proliferation, and erosion of glenoid fossa were more frequently observed in RA group than control group. Disk destruction, cortical bone erosion, and intraarticular enhancement were more prominenet in RA group. From theses results, it can be concluded that many RA patients will develop TMD symptoms and the structural changes of TMJ is more extensive than the usual TMD cases.