• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.131-138
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• 2014

While coupling wastewater treatment with microalgal bioenergy production is very promising, new approaches are needed to enhance microalgal growth and lipid accumulation in wastewater. Therefore, this study investigated the effect of iron on the growth, nutrient removal, and lipid accumulation of Scenedesmus sp. LX1 in both artificial wastewater and domestic secondary effluents. When increasing the iron concentration from 0 to 2 mg/l in the artificial wastewater, the biomass production of Scenedesmus sp. LX1 increased from 0.17 to 0.54 g/l; the nitrogen and phosphorus removal efficiency increased from 15.7% and 80.6% to 97.0% and 99.2%, respectively; and the lipid content was enhanced 84.2%. The relationship between the carrying capacity/maximal population growth rate of Scenedesmus sp. LX1 and the initial iron concentration were also in accordance with the Monod model. Furthermore, when increasing the iron concentration to 2 mg/l in four different domestic secondary effluent samples, the lipid content and lipid production of Scenedesmus sp. LX1 was improved by 17.4-33.7% and 21.5-41.8%, respectively.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.313-318
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• 2012

Application of composite structures on naval ships strongly depends on the mechanical strength and collapse behavior of the T-joints of the whole structure. Because of the weight advantages over single skin composite and bolt fastening joining, three types of T-joints using both honeycomb sandwich composite and adhesive bonding were suggested to determine the effect of T-joint configuration. It was found that joining with a urethane foam block and overlaminates using the secondary co-bonding technique improves T-joint strength.

• Journal of the Korean Arthroscopy Society
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• v.2 no.2
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• pp.185-188
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• 1998

Spontaneous osteonecrosis of the knee was first described by Ahlbck et al in 1968 as the spontaneous and sudden onset of severe pain, usually on the medial side of the knee joint, in old age(>60 years) with no specific etiologic factors. They differentiate the disease from osteochondritis dissecans, osteoarthritis, fracture, infection, neuropathic joint and secondary osteonecrosis of the knee joint. So far many investigators described this disease but had never observed cases developed in young patient with familial occurrence. The report presented here is a case of spontaneous osteonecrosis of both medial and lateral femoral condyles involving the bilateral knee joint that were treated by arthorscopic loose body removal and multiple drilling.

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.168-175
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• 2021

Objective: To investigate the static and dynamic analysis of ankle joint complex between subjects with chronic ankle instability (CAI) and healthy controls. Method: A total of 38 subjects and CAI group (N=19) and healthy control (N=19) participated in this first study. Variables that were measured in this study were as follows: 1) Subtalar joint axis inclination and deviation 2) Rearfoot angle 3) Navicular drop test 4) Heel alignment view in alignment analysis. Intra Correlation Coefficient (ICC) is used for reliability. A secondary 17 subjects are recruited including 9 of CAI and healthy for gait analysis between group. Lower extremity sagittal, frontal, and transverse kinematics were measured. All data were analyzed to ensemble curve analysis. Results: 1) There were statistically significant differences in standing rearfoot, navicular drop, heel alignment view, subtalar joint (STJ) inclination and deviation. 2) Only in sagittal, meaningful difference is showed during walking in gait analysis. Conclusion: Morphological problem can affect ankle sprain in aspect of structure with no relation to compensation of neuromuscular.

• Journal of Oral Medicine and Pain
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• v.47 no.3
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• pp.156-160
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• 2022

Temporomandibular joint (TMJ) ankylosis is a condition in which condylar movement is restricted because of fibrous or bony union between the mandibular condyle and temporal bone. TMJ ankylosis is most often caused by trauma, followed by systemic or local infection, and secondary to unknown causes. Diagnostic imaging plays a vital role in diagnosing TMJ ankylosis and establishing a treatment plan. Computed tomography (CT) or cone beam computed tomography (CBCT) is currently the imaging technique of choice to accurately demonstrate preoperative ankylosing masses and other surgically important findings, such as the shape of the mandibular condyle and the pathological changes in the joint. The osseous changes in the mandibular condyle are easily identified in the coronal and sagittal sections of CT or CBCT images. This report describes the case of a middle-aged woman who developed TMJ ankylosis of the left TMJ while undergoing repeated treatment for TMJ disease. We report the findings observed on radiographic and CBCT images through continuous observation.

• Clinical Pain
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• v.18 no.2
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• pp.121-125
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• 2019

Arthritis of hip joints deteriorates the quality of life in ankylosing spondylitis (AS) patients. Secondary to the articular inflammatory process, the shortened hip-girdle muscles contribute to the decreased joint mobility which may lead to the functional impairment. As the limitation of range of motion (ROM) usually progress slowly, clinicians regard it as a chronic condition and prescribe long-term therapy. However, by short-term intensive multimodal treatment, a 20-year-old man diagnosed as AS with severely limited hip joint ROM who relied on crutches doubled the joint angle and could walk independently only within 2 weeks. The combination included intra-articular steroid injection, electrical twitch obtaining intramuscular stimulation, extracorporeal shock wave therapy, heat, manual therapy, and stretching exercises. The management focused on the relaxation of hip-girdle muscles as well as the direct control of intra-articular inflammation. Hereby, we emphasize the effectiveness of intensive multimodal treatment in improving the function even within a short period.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.53-61
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• 2015

The tension type joint is a mechanically very efficient connection method, as it directly uses the load capacity of base metal or high tension bolt, the reduction of the number of drilling hole and fastening and the fatigue resistance. It is applied to the joint of girder and cross beam, horizontal joints of towers, beam to column joints, the secondary member joints of deck floor ends, and brackets. In this paper, static load tests for the T-type tension joint were conducted to investigate the structural behavior of the joint. The parameters were bolt diameter, flange thickness, and the reduction of clamping force of the joint. The failure modes and load capacity of joints and the effects of flange thickness, bolt diameter and clamping force were investigated.

• Composites Research
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• v.36 no.4
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• pp.259-263
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• 2023

This study investigated the open hole tensile (OHT) properties of carbon fiber/epoxy composites and compared them to bolt joint tensile (BJT) properties. The net nominal modulus and strength (1376 MPa) were found to be higher than the gross nominal strength (1041 MPa), likely due to increasing hole size. The OHT and BJT specimens exhibited similar stiffness, as expected without bolt rotation causing secondary bending. OHT specimens experienced a sharp drop in stress indicating unstable crack propagation, delamination, and catastrophic failure. BJT specimens failed through shear out on the bolt side and bearing failure on the nut side, involving fiber kinking, matrix splitting, and delamination, resulting in lower strength compared to OHT specimens. The strength retention of carbon fiber/epoxy composites with open holes was 66%. Delamination initiation at the hole's edge caused a reduction in the stress concentration factor. Filling the hole with a bolt suppressed this relieving mechanism, leading to lower strength in BJT specimens compared to OHT specimens. Bolt joint efficiency was calculated as 15%. The reduction in strength in bolted joints was attributed to fiber-matrix splitting and delamination, aligning with Hart Smith's bolted joint efficiency diagram. These findings contribute to materials selection and structural reliability estimation for carbon fiber/epoxy composites. They highlight the behavior of open hole and bolt joint configurations under tensile loading, providing valuable insights for engineering applications.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1113-1124
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• 2018

Geological dynamic hazards during deep coal mining are caused by the failure of a composite system consisting of the rock and coal layers, whereas the joint in coal affects the stability of the composite system. In this paper, the compression test simulations for the rock-coal combined body with single joint in coal were conducted using $PFC^{2D}$ software and especially the effects of joint length and joint angle on strength and failure characteristics in a rock-coal combined body were analyzed. The joint length and joint angle exhibit a deterioration effect on the strength and affect the failure modes. The deterioration effect of joint length of L on the strength can be neglected with a tiny variation at ${\alpha}$ of $0^{\circ}$ or $90^{\circ}$ between the loading direction and joint direction. While, the deterioration effect of L on strength are relatively large at ${\alpha}$ between $30^{\circ}$ and $60^{\circ}$. And the peak stress and peak strain decrease with the increase of L. Additionally, the deterioration effect of ${\alpha}$ on the strength becomes larger with the increase of L. With the increase of ${\alpha}$, the peak stress and peak strain first decrease and then increase, presenting "V-shaped" curves. And the peak stress and peak strain at ${\alpha}$ of $45^{\circ}$ are the smallest. Moreover, the failure mainly occurs within the coal and no apparent failure is observed for rock. At ${\alpha}$ between $30^{\circ}$ and $60^{\circ}$, the secondary shear cracks generated in or close to the joint tips, cause the structural instability failure of the combined body. Therefore, their failure models present as a shear failure along partial joint plane direction and partially cutting across the coal body or a shear failure along the joint plane direction. However, at ${\alpha}$ of $60^{\circ}$ and L of 10 mm, the "V-shaped" shear cracks cutting across the coal body cause its final failure. While crack nucleations at ${\alpha}$ of $0^{\circ}$ or $90^{\circ}$ are randomly distributed in the coal, the failure mode shows a V-shaped shear failure cutting across the coal body.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.308-315
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• 1996

Osteoarthritis is a noninflammatory degenerative disease affecting the articular surfaces and is accompanied by remodeling of the underlying bone. The sympotms of osteoarthritis of the temporomandibular joint are pain in the joint and muscles of mastication, limitation. Osteoarthritis is generally accepted that several factors can contribute to the trauma, aging process, internal derangement and MPDS. Radiographic features of the osteoarthritis are seen flattening of joint, sclerosis on flattened area and osteophyte or anterior lipping. In the past, osteoarthritis was considered to self-limiting disease. Currently, synovial chondromembrane is part of the process of osteoarthritis secondary to trauma. Synovial chondromatosis is an uncommon disease of cartilaginous transformation of synovial membrane with formation of loose bodies within the joint space. The pathogenesis is more an active metaplastic than a neoplastic process. The cause of synovial chondromatosis is unknown. Although trauma and inflammation have all been cited as possible factors in tis pathogenesis. The clinical sign and symptoms are unilateral swelling of the joint region, pain in the joint area and crepitus seem to be the most reliable signs and symptoms. Radiographic evidence of loose bodies may or may not be present. This is a case report of 66 year old female with synovial chondromatosis, that is advanced disease of the osteoarthrits. We treated patient with surgical excision of lose bodies, diskectomy and synovectomy. The defected articular fossa area was reconstructed with temporalis fascia flap. The result was satisfactory.