• Korean Journal of Materials Research
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• v.26 no.4
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• pp.167-172
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• 2016

The high temperature deformation behavior of $Ni_3Al$ and $Ni_3(Al,Mo)$ single crystals that were oriented near <112> was investigated at low strain rates in the temperature range above the flow stress peak temperature. Three types of behavior were found under the present experimental conditions. In the relatively high strain rate region, the strain rate dependence of the flow stress is small, and the deformation may be controlled by the dislocation glide mainly on the {001} slip plane in both crystals. At low strain rates, the octahedral glide is still active in $Ni_3Al$ above the peak temperature, but the active slip system in $Ni_3(Al,Mo)$ changes from octahedral glide to cube glide at the peak temperature. These results suggest that the deformation rate controlling mechanism of $Ni_3Al$ is viscous glide of dislocations by the <110>{111} slip, whereas that of $Ni_3(Al,Mo)$ is a recovery process of dislocation climb in the substructures formed by the <110>{001} slip. The results of TEM observation show that the characteristics of dislocation structures are uniform distribution in $Ni_3Al$ and subboundary formation in $Ni_3(Al,Mo)$. Activation energies for deformation in $Ni_3Al$ and $Ni_3(Al,Mo)$ were obtained in the low strain rate region. The values of the activation energy are 360 kJ/mol for $Ni_3Al$ and 300 kJ/mol for $Ni_3(Al,Mo)$.

• Advances in nano research
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• v.2 no.1
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• pp.1-14
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• 2014

Dislocations are basic crystal defects and represent one-dimensional native nanostructures embedded in a perfect crystalline matrix. Their structure is predefined by crystal symmetry. Two-dimensional, self-organized arrays of such nanostructures are realized reproducibly using specific preparation conditions (semiconductor wafer direct bonding). This technique allows separating dislocations up to a few hundred nanometers which enables electrical measurements of only a few, or, in the ideal case, of an individual dislocation. Electrical properties of dislocations in silicon were measured using MOSFETs as test structures. It is shown that an increase of the drain current results for nMOSFETs which is caused by a high concentration of electrons on dislocations in p-type material. The number of electrons on a dislocation is estimated from device simulations. This leads to the conclusion that metallic-like conduction exists along dislocations in this material caused by a one-dimensional carrier confinement. On the other hand, measurements of pMOSFETs prepared in n-type silicon proved the dominant transport of holes along dislocations. The experimentally measured increase of the drain current, however, is here not only caused by an higher hole concentration on these defects but also by an increasing hole mobility along dislocations. All the data proved for the first time the ambipolar behavior of dislocations in silicon. Dislocations in p-type Si form efficient one-dimensional channels for electrons, while dislocations in n-type material cause one-dimensional channels for holes.

• Clinics in Shoulder and Elbow
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• v.23 no.3
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• pp.159-165
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• 2020

Acromioclavicular (AC) joint dislocations account for about 9% of shoulder injuries. Among them, acute high-grade injury following high-energy trauma accounts for a large proportion of patients requiring surgical treatment. However, there is no gold standard procedure for operative treatment of acute high-grade AC joint injury, and several different procedures have been used for this purpose in clinical practice. This review article summarizes the most recent and relevant surgical options for acute high-grade AC joint dislocation patients and the outcomes of each treatment type.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.34-39
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• 2010

Purpose: The purpose of this study was to present methods and results for the modified Phemister operation, with a suture anchor added for augmentation of the conoid ligament in cases of acute dislocation of the acromioclavicular joint. Materials and Methods: We evaluated 14 cases of acute dislocation of the acromioclavicular joint. This included 11 cases of Rockwood type 3, and 3 cases of type 5. The mean age of patients was 45.2 years. We operated on them using an anchor for augmentation of the conoid ligament in the modified Phemister operation. The average follow-up period was 14 months and post-operative clinical analysis was conducted using the Weitzman classification, VAS Score, Constant Score and KSS Score. Results: According to Weitzman scores, 13 cases were evaluated as excellent, and one case was good. They had mean joint ranges of forward elevation of $170.7^{\circ}$, lateral elevation of 166.4, external rotation of 68.2, and internal rotation to the level of T7. The mean VAS Score was 1.9, mean Constant Score 90.8, and the mean KSS Score 91. Radiologic analysis indicated that all cases had a good result. Conclusion: The modified Phemister operation with a suture anchor added for augmentation of the conoid ligament is very effective clinically in acute dislocations of the acromioclavicular joint.

• Clinics in Shoulder and Elbow
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• v.24 no.3
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• pp.183-188
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• 2021

We report a case of a 69-year-old right-dominant man who had an open Monteggia-like lesion of the right elbow (Gustilo-Andersen IIIA) with severe proximal ulna bone loss associated with an ipsilateral ulnar shaft fracture due to a motorcycle accident. The patient underwent two-stage surgery. Wound debridement and bridging external fixation were performed at first. Three months later, a frozen massive osteochondral ulnar allograft was implanted and fixed with a locking compression plate. A superficial wound infection appeared 5 weeks after the second surgery. Superficial wound debridement, negative pressure therapy, and antibiotics were administered for 3 months, achieving infection healing. At 3 years post-surgery, the elbow range of motion was satisfactory with a Disabilities of the Arm, Shoulder and Hand (DASH) score of 16.7. Radiographs and computed tomography scans showed good allograft-bone integration without allograft reabsorption or hardware loosening. Although not complication-free, massive ulna osteochondral allograft implantation can be considered a valid option in cases of open Monteggia-like lesions associated with ulnar shaft fracture and severe bone loss in active patients, whenever osteosynthesis or joint replacement is not a proper solution. This type of bone stock restoration allows for future surgery, if needed.

• Language and Information
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• v.9 no.2
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• pp.85-105
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• 2005

This study aims at investigating the 'verb-second' phenomena indicated in complex sentences of medieval Spanish. Especially, when the complex sentence is composed of a preposed adverbial clause and its succeeding main clause, the subject inversion is noticeable in the latter. The fundamental motive of this type of inversion is due to the 'verb-second' structure, in which a topic appears in the first position and the verb immediately after the topic. So it can be said that the subject inversion is a prerequisite for a verb to be located in the second position when the adverbial clause functions as a topic to the main clause, as is often the case with Germanic languages like German, Dutch, etc.. On the contrary, modern Spanish complex sentences do not show this phenomenon, with a strong tendency to locate a grammatical subject in the preverbal position. Therefore, medieval Spanish might be typologically closer to Germanic languages than to modern Spanish. In order to argue for this assumption, the formal and functional criteria by which the preposed adverbial clause could be defined as a topic NP will be examined across the comparition with left-dislocation structure.

• Nuclear Engineering and Technology
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• v.9 no.3
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• pp.117-123
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• 1977

The strain ageing behaviour of quenched Zircaloy--4 has been studied as a function of ageing time and temperature in the temperature range 523 to 588 K for a short-ageing time of 1 to 52 seconds. At the test conditions, the strain ageing stress increased with ageing time and temperature at a strain rate of 5.55$\times$10$^{-4}$ sec$^{-1}$ . Applying stress on the Quenched Zircaloy-4, the strain ageing effect indicated following two stages: an initial stage having an activation energy of 0.39 ev considered to be due to Snoek type ordering of intersitial oxygen atoms in the stress field of a dislocation and a second stage having an activation energy of 0.60 ev, due to mainly long-range diffusion of oxygen atoms.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.1
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• pp.41-48
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• 2024

Objectives: Botulinum toxin type A (BTX), a powerful neurotoxin, can be an effective treatment choice for diverse muscular disorders and can reduce abnormal muscle activities. Abnormal movements of the mandible can be caused by involuntary and uncontrolled contractions of the lateral pterygoid muscle (LP) in various pathological situations. Previous reports have shown that BTX can reduce abnormal contractions of the LP. However, needle placement into the LP for BTX injection requires skill, experience, and sufficient anatomical knowledge. To place the needle precisely into the LP, ultrasonography (USG) can be used as an effective needle-guidance modality. USG is a non-invasive imaging modality able to create real-time images without any potential risks, including radiation exposure. Patients and Methods: The patients who had been performed USG-guided BTX injection into the LP using an intraoral approach were included in this study with a literature review and case presentations. Using the USG, four patients received BTX injections to treat recurrent temporomandibular dislocation and oromandibular dystonia resulting from involuntary LP activity. Result: Involuntary movements of the mandible were improved successfully in all patients, and showed satisfactory results without significant complication. Conclusion: The intraoral approach could prevent potential complications during needle placement. USG-guided BTX injection is an effective, convenient, and safe method that provides real-time imaging without unnecessary pain to the patient.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.331-338
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• 2005

The grain structure, dislocation density and second phase particles in various regions including the stir zone(SZ), thermo-mechanically affected zone(TMAZ), and heat affected zone(HAZ) of a friction stir weld 6.35mm thick aluminum 7075-T651 alloy were investigated and compared with the base metal. The microstruectures of nugget zone were compared according to tool rotation speeds and tool transition speeds. The hardness profiles of nugget zone were increased, while decreasing rotation speed and increasing welding speed. The optimal microstructure was gained at the low rotation speed 800rpm and th high welding speed 124mm/min. The nugget microstructures of fracture surface, transgranular dimple and quasicleavage type were showed different fracture type with the HAZ, shear fracture type.

• Journal of the Korean Orthopaedic Association
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• v.54 no.2
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• pp.110-119
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• 2019

Proximal humerus fracture can be defined as a fracture that occurs in the surgical neck or proximal part of the humerus. Despite the appropriate treatment, however, various complications and sequelae can occur, and the treatment is quite difficult often requiring surgical treatment, such as a shoulder replacement. The classification of sequelae after a proximal humerus fracture is most commonly used by Boileau and can be divided into two categories and four types. Category I is an intracapsular impacted fracture that is not accompanied by important distortions between the tuberosities and humeral head. An anatomic prosthesis can be used without greater tuberosity osteotomy. In category I, there are type 1 with cephalic collapse or necrosis with minimal tuberosity malunion and type 2 related to locked dislocation or fracture-dislocation. Category II is an extracapsular dis-impacted fracture with gross distortion between the tuberosities and the humeral head. To perform an anatomic prosthesis, a tuberosity osteotomy should be performed. In category II, there are type 3 with nonunion of the surgical neck and type 4 with severe tuberosity malunion. In type 1, non-constrained arthroplasty (NCA) without a tuberosity osteotomy should be considered as a treatment. On the other hand, reverse shoulder arthroplasty (RSA) should be considered if types 1C or 1D accompanied by valgus or varus deformity or severe fatty degeneration of the rotator cuff. In general, the results are satisfactory when NCA is performed in type 2 sequelae. On the other hand, RSA can be considered as an option when there is no bony defect of the glenoid and a defect of the rotator cuff is accompanied. In type 3, it would be effective to perform internal fixation with a bone wedge graft rather than shoulder replacement arthroplasty. Recent reports on the results of RSA are also increasing. On the other hand, recent reports suggest that good results are obtained with RSA in type 3. In type 4, RSA should be considered as a first option.