492 results on '"Kim, S. J."'
Search Results
2. Is Bevacizumab a Risk Factor for Colon Stent-Related Perforation?
- Author
-
Lee, J., Kim, S. J., and Lee, J. H.
- Subjects
- *
BEVACIZUMAB , *VASCULAR endothelial growth factors , *DIVERTICULOSIS , *DRUG-eluting stents - Abstract
This article, titled "Is Bevacizumab a Risk Factor for Colon Stent-Related Perforation?", examines the association between bevacizumab, a monoclonal antibody used in cancer treatment, and stent-related perforation in patients with acute colorectal obstruction. The study analyzed data from 397 patients who underwent self-expandable metal stent (SEMS) insertion at four tertiary hospitals. The results showed that there was no significant difference in the incidence of perforation between patients who received bevacizumab and those who did not. The authors concluded that the insertion of SEMS into colonic obstruction is a safe procedure and that bevacizumab does not increase the risk of stent-related perforation. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
3. A large reversible room temperature magneto-caloric effect in Ni-TM-Co-Mn-Sn (TM = Ti, V, Cr) meta-magnetic Heusler alloys.
- Author
-
Kim, S. J., Ryu, W. H., Oh, H. S., and Park, E. S.
- Subjects
- *
HEUSLER alloys , *TRANSITION metals , *MAGNETOCALORIC effects , *MARTENSITIC transformations , *MICROALLOYING , *MAGNETIZATION - Abstract
Herein, we achieved a large reversible room temperature magneto-caloric effect (MCE) through synergic tuning of martensitic transformation (MT) temperatures and transition entropy change (ΔStr) via micro-alloying with transition metals (Ti, V, and Cr) in Ni45Co5Mn40Sn10 meta-magnetic Heusler alloys (MHAs). By the minor addition of TM, MT temperatures were brought down to below room temperature and ΔStr was reduced while maintaining narrow MT temperature range (ΔT) and large difference in magnetization (ΔM) of Ni45Co5Mn40Sn10 MHA. In particular, Ni43.8Cr1.2Co5Mn40Sn10 MHA exhibited a very large reversible room temperature magnetic entropy change (ΔSM) of 24.5 J/kg.K with a broad operating temperature window of ~11K at 5 T. Indeed, the MHA exhibited a very effective refrigeration capacity (RCeff) of 276 J/kg for 5 T, which is the largest value among the reported Ni-Mn-based MHAs. The decrease of ΔStr reduces the magnetic field required for completely reversible MT and accelerates the saturation of ΔSM, which leads to maximum RCeff value in the composition of MHA. Thus, we can conclude that smaller ΔStr with narrow ΔT and large ΔM is a key variable to develop MHA with reversible MCE under low magnetic field, which will ultimately give us a guideline for the tailor-made design of highperformance magneto-caloric materials. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
4. Anticoagulants is a risk factor for delayed bleeding after colorectal endoscopic submucosal dissection: A HASID multicenter study.
- Author
-
Kim, S. J., Lee, J., Song, H. Y., Seo, G. S., Jin, B. C., Kim, D. H., Kim, H. S., Kim, S. W., Oh, H. H., Myung, D. S., and Joo, Y. E.
- Subjects
- *
ANTICOAGULANTS , *RODENTICIDES , *HEMORRHAGE , *FIBRINOLYTIC agents , *DISSECTION - Abstract
This article, published in the journal Endoscopy, discusses the risk factors for delayed bleeding after colorectal endoscopic submucosal dissection (ESD). The study analyzed 1,708 patients who underwent colorectal ESD and found that anticoagulants were a risk factor for delayed bleeding. Other risk factors included antithrombotic agents, antiplatelet agents, and tumor location in the rectum. The study also found that there was no difference in the risk of delayed bleeding based on the type of anticoagulant used. The authors recommend caution when performing colorectal ESD in patients receiving anticoagulants. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
5. Successful Self-expandable Metal Stent Placement for Cecal Cancer with Ileocecal Obstruction.
- Author
-
Lee, J., Kim, S. J., Lee, S. M., and Lee, J. H.
- Subjects
- *
METALS , *COLON cancer , *COLORECTAL cancer , *SMALL intestine , *BOWEL obstructions - Abstract
This article, published in the journal Endoscopy, discusses the successful placement of a self-expandable metal stent (SEMS) in a patient with cecal cancer and ileocecal obstruction. The use of colonic stenting as a bridge to surgery (CSBS) is recommended as an alternative to emergency surgery for obstructing colorectal cancer. However, CSBS in right-sided obstructive colon cancer is more challenging and has a higher risk of complications. The authors share their experience with a rare case of stent placement for cecal cancer and provide details about the procedure. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
6. Characteristics and outcomes of emergency department patients with a foreign body that entered through the ear, nose or mouth: a 10-year retrospective analysis.
- Author
-
Lee, J H and Kim, S J
- Subjects
- *
HOSPITAL emergency services , *EAR diseases , *PATIENTS , *RETROSPECTIVE studies , *ORAL diseases , *HOSPITAL mortality , *EMERGENCY medical services , *CRITICAL care medicine , *FOREIGN bodies , *NOSE diseases , *OTOLARYNGOLOGY , *DISCHARGE planning - Abstract
Background: Foreign bodies in the ear, nose and throat commonly necessitate emergency department visits. Method: This retrospective study was conducted on emergency department visits from January 2010 to December 2019 to determine characteristics and clinical prognoses of ENT patients. Patients were divided into three groups according to foreign-body entry route; patient characteristics and clinical findings were compared between groups. Results: Of 676 142 emergency department visits, 10 454 were because of ENT-related foreign bodies. The mean (± standard deviation) age of subjects was 24.0 (± 23.4) years, and 5176 patients were male (49.5 per cent). The most common entry route was the mouth (74.5 per cent). Most patients (97.1 per cent) were discharged after emergency treatment. Intensive care and in-hospital mortality occurred only in the mouth group. Conclusion: Clinical findings differ depending on foreign-body entry route. After emergency treatment, most patients were discharged; some cases presented serious complications. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
7. A crawling and drilling microrobot driven by an external oscillating or precessional magnetic field in tubular environments.
- Author
-
Kim, S. J., Jang, G. H., Jeon, S. M., and Nam, J. K.
- Subjects
- *
MAGNETIC fields , *GEOMAGNETISM , *ELECTROMAGNETIC theory , *MICROROBOTS , *MICROTECHNOLOGY - Abstract
We propose a crawling and drilling microrobot actuated by an external precessional magnetic field (EPMF) to effectively unclog obstructed blood vessels. Conventional crawling microrobots can only generate crawling motions using an external oscillating magnetic field. The proposed microrobot can generate navigating (crawling) and drilling motions selectively or simultaneously by controlling the EPMFs. We prototyped the proposed microrobot, and conducted several experiments to verify the efficacy of the crawling and drilling ability of the microrobot in a tubular environment. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
8. Finding the optimum design of the planar cutoff probe through a computational study.
- Author
-
Kim, S. J., Lee, J. J., Lee, Y. S., Kim, D. W., and You, S. J.
- Subjects
- *
ELECTRON density , *PLASMA sources , *PLASMA materials processing , *PERMITTIVITY , *ELECTROMAGNETIC waves - Abstract
A new plasma diagnostic tool called the planar cutoff probe (PCP), recently developed by Kim et al. [Plasma Sources Sci. Technol. 28, 015004(2019)], can be embedded into a chamber wall or wafer chuck electrode for non-invasive electron density measurements. The application feasibility of the probe has so far been demonstrated in terms of signal-to-noise ratio; however, for the successful application of the PCP to real plasma processing, its design should first be optimized based on a comprehensive investigation of its characteristics. Therefore, in this paper, the effects of various parameters on the measurement characteristics of the PCP are investigated and analyzed via 3D full electromagnetic wave simulation. Results show that PCP measurement discrepancies vary by numerous controllable parameters, namely, wafer thickness and relative dielectric constant, antenna distance, input electron density, and chamber pressure. Based on these findings, the condition with the smallest measurement discrepancy and where PCP measurement performance is least affected by the parameters is found and discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
9. Effect of an inhomogeneous electron density profile on the transmission microwave frequency spectrum of the cutoff probe.
- Author
-
Kim, S J, Lee, J J, Lee, Y S, Kim, D W, and You, S J
- Subjects
- *
ELECTRON distribution , *INHOMOGENEOUS plasma , *ELECTRON density , *MICROWAVES , *PLASMA sheaths , *MICROWAVE spectroscopy , *FREQUENCY spectra - Abstract
The cutoff probe (CP), which precisely measures electron density from a microwave transmission (S21) spectrum, has been successfully developed through physical models under the assumption of homogeneous plasma between the probe tips. In practice, however, the chamber and sheath structure, flow effects, and the probe insertion itself produce plasma inhomogeneity between the probe tips, which necessitates the study of any related effects on the CP measurement results. This paper investigated the effect of inhomogeneous plasma on the S21 of the CP through a three-dimensional E/M wave simulation with various density gradient directions. The simulations found, notably, double cutoff peaks and a cutoff frequency shift in the S21 that depend on the gradient direction. These results are analyzed via a simple circuit model of the CP, and their origins are elucidated at the end of this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
10. Antipsychotics and Risk of Neuroleptic Malignant Syndrome: A Population-Based Cohort and Case-Crossover Study.
- Author
-
Lao, Kim S. J., Zhao, Jiaxi, Blais, Joseph Edgar, Lam, Lam, Wong, Ian C. K., Besag, Frank M. C., Chang, Wing Chung, Castle, David J., and Chan, Esther W.
- Subjects
- *
NEUROLEPTIC malignant syndrome , *ARIPIPRAZOLE , *DRUG side effects , *ANTIPSYCHOTIC agents , *COHORT analysis , *DATABASES - Abstract
Background: Neuroleptic malignant syndrome (NMS) is a rare and acute adverse drug reaction associated with antipsychotic therapy. However, few data on the risk and epidemiology of NMS are available. Objectives: The aim of this study was to ascertain the incidence risk and all-cause mortality of NMS associated with antipsychotic use, and to assess the association of recent antipsychotic exposure and NMS. Methods: We did a population-based study using data from the Hong Kong Hospital Authority's Clinical Data Analysis and Reporting System database. Cases had a first diagnosis of NMS between 1 January 2004 and 30 November 2017. A case-crossover analysis was used to compare antipsychotic exposure 30 days before the diagnosis of NMS (index date) and a reference period 91–120 days before the index date. To adjust for potential time trends in antipsychotic exposure, we sampled from cases to match current cases and future cases, and further adjusted for select medications and acute medical conditions. Results: 297,647 patients were prescribed antipsychotics, and the incidence risk of NMS was 0.11%. Of the 336 cases included in the case-crossover analysis, 20 (6%) died within 30 days after the index date; only one case had NMS recorded as the primary cause of death. When compared with the reference period, cases were more frequently prescribed multiple antipsychotics (15.8% vs 26.8%; standardized mean difference [SMD] 0.27) and short-acting injectable antipsychotics (3.6% vs 13.7%; SMD 0.37) during the 30 days prior to the diagnosis of NMS. Odds ratios for antipsychotic exposure in the case-crossover, case-crossover adjusted for time trend, and case-crossover adjusted for time trend and potential confounders analysis were 8.00 (95% confidence interval 3.42–18.69), 5.88 (2.46–14.04), and 4.77 (1.95–11.66). Conclusions: Our results suggest that recent use of antipsychotics is associated with NMS. Although a case-only design inherently controls for confounding by time-invariant factors, residual confounding by acute medical conditions with similar presentations to NMS cannot be fully excluded. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. A simple model of solenoidal inductively coupled plasma sources considering finite size.
- Author
-
Lee, J. J., Kim, S. J., Kim, K. K., Lee, Y. S., and You, S. J.
- Subjects
- *
PLASMA sources , *ELECTRON density , *MUTUAL inductance , *CIRCUIT elements , *LOW temperature plasmas - Abstract
This paper proposes an updated transformer model for solenoidal inductively coupled plasma sources that can be applied even in low electron density regions. The proposed model can handle plasma in a finite geometry where the electric fields propagating from each boundary overlap, employing a simple analytic expression of the electric field, a one-dimensional (1D) sine hyperbolic function. Based on this field expression, all circuit elements of the transformer model that depend on the electron density, namely, plasma resistance, magnetic inductance, and mutual inductance, can now be obtained. Comparison of absorbed power as well as the circuit elements calculated using the proposed model, named here as the 1D transformer model, shows good agreement with the electromagnetic model, which is known for being quite accurate for cold plasma not only in high but also in low electron density regions. Results also indicate that the 1D transformer model is not limited to a specific setup but rather can be applied in a wide range of discharge conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
12. Mortality Risk Associated with Haloperidol Use Compared with Other Antipsychotics: An 11-Year Population-Based Propensity-Score-Matched Cohort Study.
- Author
-
Lao, Kim S. J., Wong, Angel Y. S., Wong, Ian C. K., Besag, Frank M. C., Chang, W. C., Lee, Edwin H. M., Chen, Eric Y. H., Blais, Joseph E., and Chan, Esther W.
- Subjects
- *
ARIPIPRAZOLE , *HALOPERIDOL , *ANTIPSYCHOTIC agents , *PROPORTIONAL hazards models , *MORTALITY , *COHORT analysis , *RELATIVE medical risk , *DISEASE incidence , *PROBABILITY theory , *LONGITUDINAL method - Abstract
Background: Haloperidol remains a frequently prescribed first-generation antipsychotic. However, haloperidol-associated mortality risk by all causes, cardiovascular disease (CVD), and pneumonia compared with other antipsychotics is unknown.Objective: This study investigated the mortality risk associated with long-term haloperidol treatment versus that with other antipsychotics.Methods: We identified incident antipsychotic users from 2004 to 2014 in the Clinical Data Analysis and Reporting System (CDARS), a population-based clinical database managed by the Hong Kong Hospital Authority. We included patients who were aged ≥ 18 and received antipsychotics for any indication apart from terminal illnesses or management of acute behavioural disturbance. Patients on haloperidol and other antipsychotic agents (risperidone, quetiapine, olanzapine, chlorpromazine, aripiprazole, sulpiride, amisulpride, or trifluoperazine) were matched by propensity score. Hazard ratios (HRs) for all-cause mortality and death due to CVD and pneumonia were estimated with 95% confidence intervals (CIs) using a Cox proportional hazards model.Results: In total, 136,593 users of antipsychotics were included. During a mean follow-up of 3.2 years, the incidence of all-cause mortality ranged from 186.8/1000 person-years for haloperidol to 10.4/1000 person-years for trifluoperazine. The risk of all-cause mortality was lower with non-haloperidol antipsychotics than with haloperidol, with HRs ranging from 0.68 (95% CI 0.64-0.72 [chlorpromazine]) to 0.43 (95% CI 0.36-0.53 [trifluoperazine]). Risperidone, quetiapine, sulpiride, chlorpromazine, aripiprazole, and trifluoperazine were associated with a significantly lower risk of pneumonia-related mortality. A significantly lower risk of CVD mortality was observed for risperidone, sulpiride, chlorpromazine, and quetiapine.Conclusion: Haloperidol was associated with increased overall mortality when compared with other antipsychotics in long-term follow-up. Treatment with haloperidol should be carefully considered, especially in older patients and patients at risk of CVD or pneumonia, since the risk of death appears to be lower with non-haloperidol agents. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
13. Heat treatment effects on mechanical properties of Ni–Co alloy thin films.
- Author
-
Kim, S. J., Jung, H. W., Lee, M. W., Kim, Y. J., Huh, Y. H., and Park, J. H.
- Subjects
- *
MECHANICAL heat treatment , *THIN films , *PARTICLE size distribution , *TENSILE tests , *MICROELECTROMECHANICAL systems - Abstract
Vertical type probe is made by microelectromechanical system (MEMS) process in microscale for high degree of integration and performance. To design reliable probe before manufacturing, mechanical properties in microscale is needed. Also, manufactured probe is heat-treated to release residual stress. In this paper, to understand mechanical properties and heat treatment effect in microscale, tensile tests for Ni–Co alloy thin film is performed using specimen with heat-treated under air. The Ni–Co thin film has some enhanced mechanical properties by heat effect and becomes brittle. The changes of grain size distribution and grain direction are observed through electron back-scattered diffraction (EBSD). [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
14. The role of 18F-fluciclovine PET in the management of prostate cancer: a systematic review and meta-analysis.
- Author
-
Kim, S.-J. and Lee, S.W.
- Subjects
- *
GLEASON grading system , *META-analysis , *RECEIVER operating characteristic curves , *PROSTATE cancer - Abstract
Aim: To investigate the diagnostic performance of 18F-fluciclovine positron-emission tomography (PET) or combined PET and computed tomography (PET/CT) for diagnosis of primary cancer, preoperative lymph node (LN) staging, and detection of recurrent disease of prostate cancer (PCa) through a systematic review and meta-analysis.Materials and Methods: The PubMed and EMBASE databases were searched from the earliest available date of indexing through 31 December 2018, for studies evaluating the diagnostic performance of 18F-fluciclovine PET or PET/CT for the management of PCa patients. The sensitivities, specificities, and positive and negative likelihood ratios (LR+ and LR-) across the studies were calculated and summary receiver operating characteristic curves were constructed.Results: Across 13 studies (563 patients), the pooled sensitivity for 18F-fluciclovine PET or PET/CT for diagnosis of primary PCa was 0.87 (95% confidence interval [CI]: 0.77-0.93) and a pooled specificity of 0.84 (95% CI: 0.68-0.93). For LN staging, the pooled sensitivity was 0.56 (95% CI: 0.37-0.74) and a pooled specificity of 0.98 (95% CI: 0.88-1.00). For detection of recurrent disease, the pooled sensitivity was 0.79 (95% CI: 0.60-0.91) and a pooled specificity of 0.69 (95% CI: 0.59-0.77). In meta-regression analysis, no definite variable was the source of the study heterogeneity.Conclusion: The current meta-analysis showed the moderate sensitivity and specificity of 18F-fluciclovine PET or PET/CT for the diagnosis of primary cancer, preoperative LN staging, and detection of recurrent PCa. Further large multicentre studies will be necessary to substantiate the diagnostic accuracy of 18F-fluciclovine PET/CT for management of PCa patients. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
15. Structure and magnetic properties of thermally annealed (Ni[sub 80]Fe[sub 20])[sub 1-x]Mn[sub x] thin films.
- Author
-
Yoon, C. S., Kim, S. J., Kim, Suk Jun, and Kim, C. K.
- Subjects
- *
THIN films , *SEMICONDUCTOR films , *SEMICONDUCTORS - Abstract
Ni[sub 80]Fe[sub 20]-Mn alloy thin films were fabricated using magnetron sputtering in order to study the microstructural changes that develop in an exchange couple (Ni[sub 80]Fe[sub 20] and Mn). In the process, we discovered that the alloy films phase separated into Ni[sub 80]Fe[sub 20] and Mn when annealed at 400 °C, although bulk Ni[sub 80]Fe[sub 20] and Mn are miscible at room temperature. Moreover, a strong crystallographic texture developed during annealing, especially for films with high Mn content. The increase of texture was attributed to the volume expansion taking place in the phase separation. It was speculated that the as-deposited alloy films had a large coherent interfacial strain, possibly due to inhomogeneous alloying. In turn, this hindered the formation of intermetallic compounds, and instead forced a phase separation to reduce the interfacial energy. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
16. Thermal stability of the exchanged biased CoFe/IrMn electrode for the magnetic tunnel junction as a function of CoFe thickness.
- Author
-
Lee, J. H., Kim, S. J., Yoon, C. S., Kim, C. K., Park, B. G., and Lee, T. D.
- Subjects
- *
ELECTRODES , *AUGER effect , *ELECTRON spectroscopy - Abstract
Pinned electrodes of the magnetic tunnel junction (MTJ) consisting of Ta/AlO[SUBx]/ CoFe(x)/IrMn/NiFe/Ta, where 35 Å
- Published
- 2002
- Full Text
- View/download PDF
17. Cavitation Erosion Damage Characteristics of Electroless Nickel Plated Gray Cast Iron.
- Author
-
PARK, I. C. and KIM, S. J.
- Subjects
- *
NICKEL-plating , *CAVITATION erosion , *CAST-iron , *ELECTROLYTIC corrosion , *ENGINE cylinders , *DIESEL motors - Abstract
Cavitation erosion damage behaviors in the coolant of electroless nickel plated diesel engine cylinder liners were investigated. In the case of electroless nickel coating, pitting damage was locally induced by cavitation erosion attacks. The pitting damage was promoted as galvanic corrosion accompanied it. Continued cavitation erosion attacks led to the plastic deformation, fatigue, and failure of electroless nickel coating. Consequently, local pitting damage to electroless nickel coating showed a tendency to progress in the depth direction so that the surface damage depth developed greatly. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
18. Estimation of C Solubility at SiC Saturation from the Reaction of Carbon Crucible with Si–Cr Solvent for Top-Seeded Solution Growth.
- Author
-
HYUN, K., KIM, S. J., and TAISHI, T.
- Subjects
- *
ELECTRON probe microanalysis , *SILICON crystals , *INFRARED absorption , *SOLVENTS , *CRUCIBLES , *SOLUBILITY , *COMBUSTION kinetics - Abstract
The reaction between a carbon crucible and Si–Cr solvent, and the carbon solubility at SiC saturation in Si–Cr solvent were investigated using infrared absorption after combustion, field-emission scanning electron microscopy, and electron probe microanalysis. Si0:6Cr0:4, commonly used for silicon carbide crystal growth, was maintained in a carbon crucible at 1500–1950 °C for several minutes. The amount of carbon dissolved in the solvent was determined. The carbon content initially increased for 5 min, then remained constant until 10th min, and finally increased again with time at high temperature. According to microanalysis, the second increase in carbon content was due to the crystallization of small SiC grains in the solvent after reaching saturation, while the constant carbon content was due to the equilibrium between the SiC interlayer along the crucible wall and the solvent. Assuming the plateau of carbon content closely represented the carbon solubility at each temperature, a pseudo binary phase diagram was created for Si and C. Experimentally obtained constant carbon contents is in good agreement with the carbon solubilities calculated using CALPHAD [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
19. Electrochemical Characteristics of Aluminum Alloys in Sea Water for Marine Environment.
- Author
-
YANG, Y. J. and KIM, S. J.
- Subjects
- *
ALUMINUM alloys , *CATHODIC protection , *ELECTROCHEMICAL experiments , *CORROSION resistance , *SEAWATER corrosion , *SEAWATER - Abstract
To evaluate the corrosion resistance of the 5xxx series (5052-O and 5083-H321) Al-Mg alloys and the 6xxx series (6061-T6) Al-Mg-Si alloys used in marine environments, various electrochemical experiments were conducted and the surface damages were analyzed. In the results of cathodic polarization experiments, 6061-T6 was judged to have the best anticorrosive properties because of the lowest required current density in the cathodic protection potential section and of uniform calcareous deposit formed on the surface. In addition, in the results of cyclic polarization experiments, the pitting resistance of 6061-T6 was shown to be the highest During the anodic polarization experiments 6061-T6 presented the least surface damage. Through electrochemical experiments, 6061-T6 was selected as an aluminum alloy material with excellent corrosion resistance in marine environments. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
20. Effect of Time and Temperature on the Sensitization on Alloy 600 by Electrochemical Potentiokinetic Reactivation.
- Author
-
JUNG, K. H. and KIM, S. J.
- Subjects
- *
INCONEL , *ENERGY dispersive X-ray spectroscopy , *TEMPERATURE effect , *SCANNING electron microscopes , *OPTICAL microscopes - Abstract
This study investigated the effect of temperature and time on the sensitization behavior of alloy 600. A doubleloop electrochemical potentiokinetic reactivation test was conducted to evaluate the degree of sensitization (DOS) in 0.1 M H2SO4 + 0:001 M potassium thiocyanate solution. The microstructure and surface damages of the aged specimens were characterized by optical microscope, scanning electron microscope, and energy dispersive X-ray spectroscopy. As a result of the experiment, the sensitization behavior was significantly influenced by the expansion of the Cr-depleted zone and Cr-diffusion rate depending on the aging temperature. In particular, the alloy 600 aged for 300 h or longer at 650 °C represented a very low DOS value of 3% or less, and its resistance against intergranular corrosion greatly improved. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
21. Degradation Characteristics of Microstructure and Mechanical Properties for 9Cr-1MoVNb Steel aged under High-Temperature.
- Author
-
JUNG, K. H. and KIM, S. J.
- Subjects
- *
ENERGY dispersive X-ray spectroscopy , *VICKERS hardness , *HARDNESS testing , *SCANNING electron microscopy , *MICROSTRUCTURE - Abstract
Thermal aging was conducted at 650 °C until 1,000 h under the atmospheric environment to evaluate the degradation characteristics of microstructure and mechanical properties of 9Cr-1MoVNb steel. The analysis of the microstructure and carbide of aged specimens was conducted by scanning electron microscopy and energy dispersive X-ray spectroscopy. The mechanical properties were evaluated by tensile and Vickers hardness tests. In addition, fractured tensile specimens were characterized by using scanning electron microscopy and energy dispersive X-ray spectroscopy to observe the changes in fracture mode with aging time. As a result, loss of martensite lath, coarsening of M23C6 carbide, and precipitation of Laves phase were observed after aging for 100 h. Degradation leads to deterioration in mechanical properties due to the effect of the nucleation and coarsening of Cr-rich M23C6 carbide. However, the change in fracture mode was more affected by the Laves phase (Fe2Mo) than the M23C6. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
22. Effects of Plasma Ion Nitriding Temperatures on Cavitation-Erosion Resistance of STS 304 in Seawater.
- Author
-
CHONG, S. O. and KIM, S. J.
- Subjects
- *
NITRIDING , *ION temperature , *SEAWATER , *STAINLESS steel , *CORROSION resistance , *MATERIAL erosion , *ATMOSPHERIC pressure - Abstract
Plasma ion nitridation was performed on stainless steel at various temperature parameters to characterize cavitation-erosion resistance under seawater conditions. Plasma ion nitriding was carried out at a relatively low temperature of 400 to 500 °C for 10 h at a gas ratio of 25% N2 + 75% H2 and a chamber pressure of 250 Pa in consideration of corrosion resistance by chlorine ions. Cavitation-erosion experiments were conducted for 10 h in compliance with modified ASTM G-32. The cavitation-erosion test for 10 h showed the lowest surface damage, weight loss, and depth of damage at 450 °C, where the γN phase was most deeply formed. On the other hand, at 500 °C, the cavitation-erosion damage tended to increase with increasing γ'-Fe4N phase and CrN. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
23. A transmission line model of the cutoff probe.
- Author
-
Kim, S J, Lee, J J, Kim, D W, Kim, J H, and You, S J
- Subjects
- *
ELECTRIC lines , *ELECTRON density - Abstract
The previously proposed circuit model has proven to be a powerful tool to analyze and improve the characteristics of the cutoff probe. This model revealed the mechanism of formation of the transmission microwave frequency spectrum of the cutoff probe, and allows for a more precise measurement of electron density by taking into account electron-neutral collision frequency and sheath width. However, a recent study has found that there is a discrepancy between the circuit model and 3D full E/M wave (EMW) simulation, in that the circuit model is applicable to the measurement of low-density plasma but not high-density plasma; this indicates that the basis of the circuit model for the cutoff probe seems to be incomplete (Kim et al 2015 2015 KPS Fall Meeting). To resolve this problem, the current paper proposes a new model of the cutoff probe, named the transmission line (TL) model, based on TL theory. Results of the TL model are compared with EMW simulation, with the TL model found to reproduce the results of EMW simulation in both high-density as well as low-density plasma. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
24. Extracellular production of functional single‐chain variable fragment against aflatoxin B1 using Escherichia coli.
- Author
-
Na, K.‐I., Kim, S.‐J., Choi, D.‐S., Min, W.‐K., Kim, S.‐G., and Seo, J.‐H.
- Subjects
- *
RECOMBINANT antibodies , *AFLATOXINS , *MUTAGENESIS , *ESCHERICHIA coli , *BACTERIAL cultures , *BIOTECHNOLOGY - Abstract
scFv‐BM3 is a single‐chain variable fragment (scFv) against aflatoxin B1 (AFB1) engineered by affinity maturation and site‐directed mutagenesis, and thus has a 31‐fold higher affinity than its wild‐type. To apply scFv‐BM3 to immunological detection of AFB1, periplasmic expression in Escherichia coli was attempted to produce a functional form of scFv‐BM3. scFv‐BM3 accumulated as inactive aggregates in the cells. However, it was found that scFv‐BM3 secreted into the culture medium had binding activity to AFB1. Expression conditions for scFv‐BM3 were further manipulated to enhance secretion into the culture medium. This extracellular secretion of functional scFv‐BM3 was significantly improved by supplementation with Triton X‐100 and optimization of expression conditions. The scFv‐BM3 purified from the culture medium exhibited a typical antiparallel β‐sheet structure and adopted a proper conformation to bind AFB1 with high affinity and specificity in various biophysical and biochemical analyses. Significance and Impact of the Study: Single‐chain variable fragments (scFvs) are recombinant antibodies that are difficult to produce as a functional form in Escherichia coli. This study demonstrates the production of functional scFvs against aflatoxin B1 (AFB1) (scFv‐BM3) using Escherichia coli by extracellular secretion. While periplasmic expression of scFv‐BM3 resulted in formation of inactive aggregates in E. coli, the scFv‐BM3 secreted into the culture medium adopted a properly folded structure for specific binding to AFB1. This study promotes the application of functional scFv‐BM3 to the immunological detection of AFB1 in biotechnology fields. Significance and Impact of the Study: Single‐chain variable fragments (scFvs) are recombinant antibodies that are difficult to produce as a functional form in Escherichia coli. This study demonstrates the production of functional scFvs against aflatoxin B1 (AFB1) (scFv‐BM3) using Escherichia coli by extracellular secretion. While periplasmic expression of scFv‐BM3 resulted in formation of inactive aggregates in E. coli, the scFv‐BM3 secreted into the culture medium adopted a properly folded structure for specific binding to AFB1. This study promotes the application of functional scFv‐BM3 to the immunological detection of AFB1 in biotechnology fields. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
25. The usefulness of the SOFA and APACHE II scoring systems for the early prediction of mortality in patients with dapsone poisoning.
- Author
-
Lee, Y., Kim, S. J., Kim, Y. S., Kim, H., Lee, J., Cha, Y. S., Lee, D. K., and Go, T. H.
- Subjects
- *
HEALTH , *EVALUATION , *DEATH forecasting , *DAPSONE , *DRUG toxicity - Abstract
The rate of mortality from dapsone poisoning is high because of the long absorption half-life of dapsone. This study aimed to evaluate the usefulness of the sequential organ failure assessment (SOFA) and acute physiology and chronic health evaluation II (APACHE II) scoring systems for the early prediction of mortality in patients with dapsone poisoning. This is a retrospective and observational study of consecutive patients diagnosed with dapsone poisoning. The SOFA and APACHE II scores were obtained within the first 24 h of admission. Patients were divided into survivor and non-survivor groups. In total, 106 patients were included. The SOFA scores of the survivor and non-survivor groups were 1 (0–8) and 4 (1–10), respectively (p < 0.001). The APACHE II scores of the survivor and non-survivor groups were 9 (1–25) and 14 (3–23), respectively (p < 0.001). Based on these scores and in-hospital mortality cases, the standardized mortality ratios for the APACHE II and SOFA were 1.00 (95% confidence interval (CI): 0.64–1.48) and 1.00 (95% CI: 0.64–1.49), respectively. In the model adjusted for clinically important variables and variables with significant differences between the survivor and non-survivor groups, the area under the curve of the SOFA (0.907; 95% CI: 0.834–0.955) was significantly higher than that of the APACHE II (0.793; 95% CI: 0.703–0.867) (p = 0.008). The SOFA and APACHE II score systems had good discrimination and satisfactory calibration performance in patients with dapsone poisoning. However, the SOFA score was a more useful method in predicting mortality than the APACHE II score. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
26. Toward safer prescribing: evaluation of a prospective drug utilization review system on inappropriate prescriptions, prescribing patterns, and adverse drug events and related health expenditure in South Korea.
- Author
-
Kim, S. J., Han, K.-T., Kang, H.-G., and Park, E.-C.
- Subjects
- *
DRUG side effects , *CONNECTIVE tissue diseases , *DRUG interactions , *DRUG prescribing , *GASTROINTESTINAL hemorrhage , *LONGITUDINAL method , *EVALUATION of medical care , *MEDICAL care costs , *MUSCULOSKELETAL system diseases , *NONSTEROIDAL anti-inflammatory agents , *PATIENT safety , *PEPTIC ulcer , *PROBABILITY theory , *REGRESSION analysis , *RISK assessment , *TIME series analysis , *PHYSICIAN practice patterns , *PROPORTIONAL hazards models , *INAPPROPRIATE prescribing (Medicine) , *ECONOMICS ,EVALUATION of drug utilization - Abstract
Objectives This study aimed to evaluate the effect of the prospective drug utilization review (DUR) system introduced in Korea in December 2010 as a real-time method to improve patient safety, in terms of changes in prescribing practices, adverse drug events (ADEs), and ADE-related healthcare expenditure, using non-steroidal anti-inflammatory drugs (NSAIDs) and their common ADEs as a guide. Study design We used an interrupted time-series study design using generalized estimating equations to evaluate changes in prescription rate and ADE-related healthcare expenditure. Cox regression analysis was used to evaluate the probability of NSAID-associated ADEs. Methods A total of 154,585 outpatients with musculoskeletal or connective tissue disorders, without pre-existing gastric bleeding or ulcers were included in this study. The primary outcome was the level and trend change in prescription rate, drug–drug interactions, coprescribed gastro-protective drugs, and defined daily dose (DDD) of NSAIDs. The secondary outcome was the probability of ADEs and changes in ADE-related healthcare expenditure. Results There was a significant trend change after introducing the DUR system in terms of drug–drug interactions (−3.6%) and coprescribed gastro-protective drugs (+0.6%). The mean DDD of NSAIDs increased by 0.2. The probability of ADEs decreased overall (−1.7%) and in the high-risk group (age ≥65 years; −9.6%); however, only the latter was significant. There was no significant trend or level change in ADE-related health expenditure. Conclusions The introduction of the DUR system was associated with more efficient prescribing, including a reduction in drug–drug interactions and an increase in the use of gastro-protective drugs. The system had a positive effect on patient outcome but was not associated with reduced ADE-related costs. Further studies are needed to evaluate the long-term effects of the DUR system in Korea. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
27. Stark effect and Stark-ladder effect in Al0.4Ga0.6As/GaAs asymmetric coupled multiple quantum wells.
- Author
-
Kim, S. J., Oh, Y. T., Kim, S. K., Kang, T. W., and Kim, T. W.
- Subjects
- *
ELECTRIC fields , *GALLIUM arsenide , *QUANTUM wells , *PHOTOLUMINESCENCE - Abstract
Presents a study which investigated the influence of electric field on the excitation states in Al[0.4]Ga[0.6]As and gallium arsenide asymmetric coupled quantum wells grown by molecular-beam epitaxy through photoluminescence measurements. Effect of electric fields on quantum wells; Equation of the effective mass Hamiltonian for the electron and hole; Materials and methods used; Calculation of the theoretical energy levels and wave functions.
- Published
- 1995
- Full Text
- View/download PDF
28. Sudden visual loss in a patient with systemic lupus erythematosus caused by a combination of the disease itself and drug toxicity.
- Author
-
Lee, H -J and Kim, S -J
- Subjects
- *
DRUG toxicity , *OPTIC disc , *OPTIC neuritis , *BLOODBORNE infections , *SYSTEMIC lupus erythematosus - Abstract
Funduscopy revealed optic disc swelling with hemorrhage and macular edema in the right eye, and no optic disc swelling in the left eye (Figure 1a, b). Funduscopy showing severe optic disc swelling with hemorrhage in the right eye (a) and normal optic disc in the left eye (b) at the initial visit. Fundus fluorescein angiography showing severe optic disc leakage in the right eye and retinal capillary leakage in both eyes (c, d). [Extracted from the article]
- Published
- 2020
- Full Text
- View/download PDF
29. Is calcium phosphate augmentation a viable option for osteoporotic hip fractures?
- Author
-
Kim, S.-J., Park, H.-S., Lee, D.-W., and Lee, J.-W.
- Subjects
- *
CALCIUM , *PHOSPHATES , *BONE cements , *CLOSED fractures , *BONE screws , *BONE grafting , *ENDOSCOPIC surgery , *FRACTURE fixation , *BONE fractures , *HIP joint injuries , *INTERNAL fixation in fractures , *INTERVIEWING , *OSTEOPOROSIS , *QUESTIONNAIRES , *SELF-evaluation , *SURGICAL complications , *SURVEYS , *TELEPHONES , *VISUAL analog scale , *TREATMENT effectiveness , *RETROSPECTIVE studies , *PATIENTS' attitudes , *THERAPEUTICS - Abstract
Summary: The use of calcium phosphate bone cement has been described to allow for retention of reduction. Therefore, we evaluated whether augmentation with resorbable calcium phosphate could improve fracture stability in osteoporotic hip fractures. The results showed that augmentation with calcium phosphate cement significantly improved the stability of intertrochanteric fractures.Introduction: The aim with this study was to measure whether augmentation with resorbable calcium phosphate cement could improve fracture stability in osteoporotic hip fractures.Methods: We retrospectively reviewed 82 patients who underwent closed reduction and internal fixation with proximal femoral nail (PFN) for unstable intertrochanteric fractures between 2014 and 2017. In 42 of 82 patients, patients were treated with a PFN alone (group I). These patients were compared with 40 patients for whom the same device combined with calcium phosphate cement for augmentation was used (group II). Questionnaire surveys or telephone interviews were conducted and patients completed a self-report Harris hip score (HHS) and visual analog scale (VAS) scores. Radiographic outcomes including mean sliding distance of screw, femoral shortening, and varus collapse were compared. Postoperative complications were compared.Results: Clinical outcomes at 6 months after surgery were equivalent in both groups. Screw sliding, femoral shortening, and varus collapse were all significantly reduced in the cemented group at the last follow-up (p < 0.001, p = 0.005, p < 0.001, respectively). A total of 9 (21%) complications occurred in group I. In contrast, 2 (5%) complications were seen in group II (p = 0.029).Conclusions: Augmentation with calcium phosphate cement significantly improved the stability of intertrochanteric fractures fixed with a PFN and reduced overall failure rates. We believe augmentation with resorbable calcium phosphate cement for osteoporotic hip fractures is a reasonable option in selected patients. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
30. EFFECTS OF DIETARY CRUDE PROTEIN LEVELS ON INTAKE, DIGESTIBILITY, AND CRUDE PROTEIN BALANCE OF GROWING KOREAN NATIVE GOATS (CAPRA HIRCUS COREANAE).
- Author
-
Park, J. H., Kim, S. J., Kim, N. Y., Jang, S. Y., Lee, J. W., Yun, Y. S., and Moon, S. H.
- Subjects
- *
PROTEIN content of food , *FOOD consumption , *GOAT behavior , *DRY matter in animal nutrition , *DIGESTION , *MAMMALS - Abstract
This study was conducted to determine the adequate dietary CP level for growing wethers by investigating the effect of dietary CP level on dry matter intake, apparent digestibility, and protein balance inKorean native goats. Each growing wether was fed three diets that were formulated to contain low (13%, T1), medium (15%, T2), and high (18%, T3) levels of CP based on dry matter. Dietary protein levels affected the apparent digestibility of CP, CP intake (CPI), urinary CP, digestible CP, and CP efficiency (p<0.05). The apparent CP digestibility increased linearly as dietary CP increased (T1=73.03%, T2=76.49%, T3=80.66%; p<0.05). The CPI and digestible CP for T3 (129.92g/d, 104.93g/d) were also higher (p<0.05) than those for T1 (90.39g/d, 65.68g/d), in addition, urinary emission for T3 (55.23g/d) was higher (p<0.05) than that for T2 (27.11g/d). CP utilization efficiency for T2 (49.11%) and T3 (44.42%) were both higher (p<0.05) than that for T1 (26.14%). A strong linear relationship existed between CPI and digestible CP (p<0.001, r2=0.988). The results from this study suggest that an adequate CP level for achieving optimal growth performance of growing Korean native goats is 15% of dietary intake. [ABSTRACT FROM AUTHOR]
- Published
- 2018
31. Analgesic efficacy of meloxicam with or without a buprenorphine patch in cats after ovariohysterectomy.
- Author
-
HEO, S. Y., KIM, S. J., and KIM, N. S.
- Subjects
- *
ANALGESICS , *BUPRENORPHINE , *HYSTERO-oophorectomy , *PAIN management , *HYDROCORTISONE - Abstract
The purpose of this prospective double blind clinical study was to evaluate the analgesic efficacy of meloxicam with/without a buprenorphine patch for pain management after ovariohysterectomy in cats. Cats were randomly divided into two groups: ten cats were treated with meloxicam s.c. after ovariohysterectomy (Group A), and eight cats were treated with s.c. meloxicam and a 20 μg/h buprenorphine transdermal patch (Group B). For patch treatment, the cat's hair was clipped on the left side in the thoracic area. Pain scores were assessed at 0.5, 1, 2, 4, 6, 8, 24 and 30 h post-ovariohysterectomy extubation. To evaluate postoperative pain, 4A-VET pain scale and visual analogue scale pain scores were used. In addition, blood was collected from all cats to determine the cortisol levels at -2 h and at 0.5, 4, 6 and 24 h after extubation. The 4A-VET scores for Group B were significantly lower at 1, 4, 6, 8, 24 and 30 h than the scores for Group A. The visual analogue scale pain scores for Group B were significantly lower at 4, 6, 24 and 30 h than the scores for Group A. Serum cortisol concentrations were not significantly different between Groups A and B at any of the measured intervals. There was a significant positive correlation between postoperative visual analogue scale and 4A-VET pain scores in both groups. Our results should be subject to careful interpretation as the study was limited by its small sample size and by observer subjectivity. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
32. Microbiological survey of commercial tattoo and permanent makeup inks available in the United States.
- Author
-
Nho, S. W., Kim, S.‐J., Kweon, O., Howard, P. C., Moon, M. S., Sadrieh, N. K., and Cerniglia, C. E.
- Subjects
- *
TATTOOING , *MICROBIOLOGY , *BODY art , *BIOLOGY , *ANTI-infective agents - Abstract
Abstract: Aims: Tattooing and use of permanent makeup (PMU) has dramatically increased over the last decade, with a concomitant increase in ink‐related infections. The aim of this study was to determine whether micro‐organisms are present, and if so, the number and their identification in the commercial tattoo and PMU inks available in the United States. Methods and Results: We surveyed 85 unopened tattoo and PMU inks, purchased from 13 companies. We incubated 100
μ l of ink samples on trypticase soy agar plates for bacterial growth, 7H10 Middlebrook medium for mycobacterial growth, and Sabouraud dextrose medium for fungal growth. In total, 42 inks were contaminated with micro‐organisms (49%). Thirty‐three inks were contaminated with bacteria, 2 inks with fungi, and 7 inks had both bacterial and fungal growth. Mycobacteria were not detected in any of the examined tattoo and PMU inks. In 26 inks, microbial concentrations ranged between 101 and 103 CFU per ml, but higher counts (>103 CFU per ml) were recorded in 16 inks. We identified 83 bacteria by their 16S rDNA sequences, including 20 genera and 49 species. Strains ofBacillus spp. (53%) were dominant, followed byLysinibacillus fusiformis (7%) andPseudomonas aeruginosa (5%). Thirty‐four (41%) possibly clinically relevant strains were identified, includingP. aeruginosa ,Dermacoccus barathri andRoseomonas mucosa , some of which have been previously reported to be associated with human skin infections. Conclusions: The results indicate that commercial tattoo and PMU inks on the US market surveyed in this study contain a wide range of micro‐organisms, including pathogenic bacteria. Significance and Impact of the Study: Microbial contaminants in tattoo and PMU inks are an emerging safety concern for public health. This study provides evidence that microbial contamination of tattoo and PMU inks available in the United States is more common than previously thought and highlights the importance of monitoring these products for potentially pathogenic micro‐organisms. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
33. Sequential chemotherapy/radiotherapy was comparable with concurrent chemoradiotherapy for stage I/II NK/T-cell lymphoma.
- Author
-
Kwong, Y L, Kim, S J, Tse, E, Oh, S Y, Kwak, J Y, Eom, H S, Do, Y R, Mun, Y C, Lee, S R, and Shin, H J
- Subjects
- *
CHEMORADIOTHERAPY , *T-cell lymphoma , *ANTHRACYCLINES , *CIRCULATING tumor DNA , *MEDICAL statistics , *THERAPEUTICS - Abstract
Background: In stage I/II natural killer (NK)/T-cell lymphoma, concurrent chemoradiotherapy (CCRT) had previously been shown to result in superior outcome compared with anthracycline-containing regimens, which have since been considered ineffective. The role of CCRT in comparison with approaches employing nonanthracycline-containing chemotherapy (CT) and sequential radiotherapy (RT) in such patients remains to be defined. Patients and methods: Three hundred and three untreated patients (207 men, 96 women; median age: 51, 18-86 years) with stage I/II NK/T-cell lymphoma who had received nonanthracycline-containing regimens were collected from an international consortium and retrospectively analyzed. Treatment included single modality (CT and RT), sequential modalities (CTþRT; RTþCT) and concurrent modalities (CCRT; CCRTþCT). The impact of clinicopathologic parameters and types of treatment on complete response (CR) rate, progression-free-survival (PFS) and overall-survival (OS) was evaluated. Results: For CR, stage (P=0.027), prognostic index for NK/T-cell lymphoma (PINK) (P=0.026) and types of initial treatment (P=0.011) were significant prognostic factors on multivariate analysis. On Cox regression analysis, ECOG performance score (P=0.021) and PINK-EBV DNA (PINK-E) (P=0.002) significantly impacted on PFS; whereas ECOG performance score (P=0.008) and stage (P<0.001) significantly impacted on OS. For comparing CCRT6CT and sequential CTþRT, CCRT6CT patients (n=190) were similar to sequential CTþRT patients (n=54) in all evaluated clinicopathologic parameters except two significantly superior features (higher proportion of undetectable circulating EBV DNA on diagnosis and lower PINK-E scores). Despite more favorable pre-treatment characteristics, CCRT6CT patients had CR rate, PFS and OS comparable with sequential CTþRT patients on multivariate and Cox regression analyses. Conclusions: In stage I/II NK/T-cell lymphomas, when effective chemotherapeutic regimens were used, CCRT and sequential CTþRT gave similar outcome. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
34. Magnetic field dependence of micromachined Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8+δ] intrinsic Josephson junctions with a submicron loop.
- Author
-
Kim, S.-J., Chen, J., Nakajima, K., Yamashita, T., Takahashi, S., and Hatano, T.
- Subjects
- *
JOSEPHSON junctions , *MICROELECTROMECHANICAL systems , *MAGNETIC fields - Abstract
Two-stacked intrinsic Josephson junctions (IJJs) on a Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8 + δ](Bi-2212) whisker with a submicron hole are micromachined by a 3D focused ion beam (FIB) etching method. The junction area, the number of elementary junctions, and the loop area of the SQUIDs are 3, 20, and 0.42 µm², respectively. The SQUIDs show typical I-V characteristics of IJJs with a critical current I[sub c] of 12 µA at 4.2 K. The modulation parameter Β[sub L]( = 2I[sub C]L / Φ[sub 0]) is 6.4, and the inductance L of the SQUID is ll20pH. That includes the inductances of the elementary junction around a SQUID loop. In a strong magnetic field, the Fraunhofer pattern is obtained and well fitted to the calculated value from the junction size, ΔB = Φ[sub 0] / tW; t is the interlayer distance, and W is the junction width. In a low magnetic field, approximately 10% of the I[sub C] modulation corresponding to the value of β[sub L] is observed. Eighty G of the modulation period approximately agrees with the value calculated from the SQUID. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
35. Fabrication and characteristics of submicron tunneling junctions on high T[sub c] superconducting c-axis thin films and single crystals.
- Author
-
Kim, S.-J. and Yamashita, T.
- Subjects
- *
ELECTRIC properties of metallic films , *ELECTRIC properties of thin films , *SEMICONDUCTOR films , *QUANTUM tunneling , *ELECTRONICS - Abstract
We report successful fabrication and characteristics of submicron-size tunneling junctions using c-axis YBa[sub 2]Cu[sub 3]O[sub 7-y] (YBCO) thin films of 800 nm thickness and Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8+δ](Bi-2212) single-crystal whiskers. The junctions were made using a three-dimensional focused-ion-beam etching method. First, a microbridge was patterned in a required junction width by normal direction etching. By tilting the sample stage up to 90°, two grooves on the bridge were etched from the lateral direction in order to create the required junction size. The 60 K YBCO junctions did not show any degradation of critical current density (J[sub c]) down to an in-plane area of 0.5 μm2 and showed current-voltage (I-V) characteristics of the collective switching transition from the zero voltage state to the resistive state. For Bi-2212 stacks smaller than 1 μm2, we identified some of the features of charging effects on the I-V characteristics. &! copy; 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
36. Distortional hardening concept for modeling anisotropic/asymmetric plastic behavior of AZ31B magnesium alloy sheets.
- Author
-
Lee, J., Kim, S.-J., Lee, Y.-S., Lee, J.-Y., Kim, D., and Lee, M.-G.
- Subjects
- *
MAGNESIUM alloys , *HARDENING (Heat treatment) , *TENSION loads , *PLASTICS , *LIGHT metal alloys - Abstract
A continuum-based approach for describing the plastic hardening behavior of magnesium alloy sheets subjected to non-proportional strain path changes at room temperature is presented. The constitutive model is based on an anisotropic distortional yield function that combines a stable component and a fluctuating component. The stable component initiates the yield criterion that characterizes the typical strength differential (SD) effect between tension and compression in magnesium alloys at room temperature. The evolution of the fluctuating component is reformulated based on its cubic metal counterpart to represent the deformation behavior of magnesium alloys, which consists of slip- and twinning-dominant deformation modes. To validate the proposed model, a predictor–corrector numerical algorithm was implemented in a finite element (FE) program by using a user material subroutine, and its numerical accuracy was evaluated by iso-error map analysis. Comparison of the experimental and simulated results obtained for various loading path changes showed that, although the model was not formulated using the kinematic hardening concept, the model could reproduce complex features of the stress–strain responses of an AZ31B magnesium alloy sheet under non-proportional loading paths, i.e., asymmetric hardening behavior under tension and compression, the sigmoidal nature of the hardening curve during monotonic compression and compression followed by tension. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
37. Epigenetic alterations of the BDNF gene in combat-related post-traumatic stress disorder.
- Author
-
Kim, T. Y., Kim, S. J., Chung, H. G., Choi, J. H., Kim, S. H., and Kang, J. I.
- Subjects
- *
TREATMENT of post-traumatic stress disorder , *DNA methylation , *PROMOTERS (Genetics) , *PYROSEQUENCING , *BRAIN-derived neurotrophic factor , *EPIGENETICS - Abstract
Objective Brain-derived neurotrophic factor ( BDNF) plays a crucial role in modulating resilience and vulnerability to stress. The aim of this study was to investigate whether epigenetic regulation of the BDNF gene is a biomarker of post-traumatic stress disorder ( PTSD) development among veterans exposed to combat in the Vietnam War. Methods Using the Clinician-Administered PTSD Scale, combat veterans were grouped into those with ( n = 126) and without ( n = 122) PTSD. DNA methylation levels at four CpG sites within the BDNF promoter I region were quantified in the peripheral blood using pyrosequencing. The effects of BDNF DNA methylation levels and clinical variables on the diagnosis of PTSD were tested using binary logistic regression analysis. Results Subjects with PTSD showed a higher DNA methylation of four CpG sites at the BDNF promoter compared with those without PTSD. High methylation levels at the BDNF promoter CpG site, high combat exposure, and alcohol problems were significantly associated with PTSD diagnosis. Conclusions This study demonstrated an association between higher DNA methylation of the BDNF promoter and PTSD diagnosis in combat-exposed individuals. Our findings suggest that altered BDNF methylation may be a valuable biomarker of PTSD after trauma exposure. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
38. Effects of dietary supplementation of bacteriophages against enterotoxigenic Escherichia coli (ETEC) K88 on clinical symptoms of post-weaning pigs challenged with the ETEC pathogen.
- Author
-
Lee, C. Y., Kim, S. J., Park, B. C., and Han, J. H.
- Subjects
- *
ESCHERICHIA coli diseases , *ANIMAL weaning , *DIETARY supplements , *BACTERIOPHAGES , *SWINE nutrition , *BACTERIAL colonies , *SWINE - Abstract
The present study was performed to investigate the effects of dietary supplementation of bacteriophages (phages) against enterotoxigenic Escherichia coli (ETEC) K88 as a therapy against the ETEC infection in post-weaning pigs. Two groups of post-weaning pigs aged 35 days, eight animals per group, were challenged with 3.0 × 1010 colony forming units of ETEC K88, a third group given the vehicle. The unchallenged group and one challenged group were fed a basal nursery diet for 14 days while the remaining challenged group was fed the basal diet supplemented with 1.0 × 107 plaque forming units of the phage per kg. Average daily gain (ADG), goblet cell density and villous height:crypt depth (VH:CD) ratio in the intestine were less in the challenged group than in the unchallenged group within the animals fed the basal diet (p < 0.05); the reverse was true for rectal temperature, faecal consistency score (FCS), E. coli adhesion score (EAS) in the intestine, serum interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α) concentrations and digesta pH in the stomach, caecum and colon. The ETEC infection symptom within the challenged animals was alleviated by the dietary phage supplementation (p < 0.05) in ADG, FCS, EAS in the jejunum, serum TNF-α concentration, digesta pH in the colon, goblet cell density in the ileum and colon and VH:CD ratio in the ileum. Moreover, the infection symptom tended to be alleviated (p < 0.10) by the phage supplementation in rectal temperature, EAS in the ileum and caecum, and VH:CD ratio in the duodenum and jejunum. However, EAS in the colon, digesta pH in the stomach and caecum, and goblet cell density in the jejunum did not change due to the dietary phage. Overall, results indicate that the phage therapy is effective for alleviation of acute ETEC K88 infection in post-weaning pigs. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
39. Risk of malignancy according to sub-classification of the atypia of undetermined significance or follicular lesion of undetermined significance ( AUS/ FLUS) category in the Bethesda system for reporting thyroid cytopathology.
- Author
-
Kim, S. J., Roh, J., Baek, J. H., Hong, S. J., Shong, Y. K., Kim, W. B., and Song, D. E.
- Subjects
- *
CYTOLOGICAL techniques , *CELLULAR pathology , *THYROID cancer , *TUMOR classification , *NEEDLE biopsy , *CANCER risk factors - Abstract
Objective According to the Bethesda System for Reporting Thyroid Cytopathology, atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) is a heterogeneous category that includes cases with architectural and/or nuclear atypia insufficient to warrant classification as malignant neoplasms. The ambiguous and descriptive characteristics of the AUS/FLUS category mean that the impact of the present guidelines on repeat fine needle aspiration (FNA) is unclear. The present study reclassified AUS/FLUS cases into four sub-categories and then correlated them with histological or cytological follow-up data to clarify the risk of malignancy. Methods Ninety-four cases of AUS/FLUS with available follow-up data were reviewed and assigned to one of four sub-categories: (i) AUS-N (nuclear atypia); (ii) AUS-A (architectural atypia); (iii) AUS-O (predominant oncocytic changes); and (iv) AUS-N/A (both nuclear and architectural atypia). The four sub-categories were correlated with subsequent histological or cytological follow-up data, including core needle biopsy, resection, or repeat FNA. Results Malignancy was identified in 34 of 94 cases (36.2%). The upper limit estimate for malignancy was 43.6%, and the lower limit estimate was speculated as 9.8%. The malignancy rate was highest in cases within the AUS-N sub-category (65.8%, range 16.6%-78.1%). Conclusions The present study suggests that cases in the AUS/FLUS category have a higher risk of malignancy than previously thought. Because of the heterogeneous nature of the AUS/FLUS category, further sub-classification might be more effective in achieving appropriate risk stratification and better clinical management. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
40. Biomimetic fabrication of calcium phosphate/chitosan nanohybrid composite in modified simulated body fluids.
- Author
-
Park, K. H., Kim, S. J., Hwang, M. J., Song, H. J., and Park, Y. J.
- Subjects
- *
BIOMIMETIC chemicals , *FABRICATION (Manufacturing) , *CALCIUM phosphate , *CHITOSAN , *COMPOSITE materials , *BODY fluids - Abstract
In this study, nucleation and growth of bone-like hydroxyapatite (HAp) mineral in modified simulated body fluids (m-SBF) were induced on chitosan (CS) substrates, which were prepared by spin coating of chitosan on Ti substrate. The m-SBF showed a two fold increase in the concentrations of calcium and phosphate ions compared to SBF, and the post-NaOH treatment provided stabilization of the coatings. The calcium phosphate/chitosan composite prepared in m-SBF showed homogeneous distribution of approximately 350 nm-sized spherical clusters composed of octacalcium phosphate (OCP; Ca8H2(PO4)6?5H2O) crystalline structure. Chitosan provided a control over the size of calcium phosphate prepared by immersion in m-SBF, and post-NaOH treatment supported the binding of calcium phosphate compound on the Ti surface. Post-NaOH treatment increased hydrophilicity and crystallinity of carbonate apatite, which increased its potential for biomedical application. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
41. INTEGRATION OF PRE-SIMULATION AND SENSORLESS MONITORING FOR SMART MOULD MACHINING.
- Author
-
Kim, S.-J.
- Subjects
- *
MACHINE molding (Founding) , *COMPUTER simulation , *SENSORLESS control systems , *CUTTING force , *NUMERICAL control of machine tools , *ALGORITHMS - Abstract
A smart mould machining system, which detects machining status and controls the CNC through presimulation and real-time data, was developed. Pre-simulation predicts cutting forces, and inserts the best feed rate and virtual load on each line of the NC data. The active feed rate reduced machining by up to 36%, without increasing the maximum cutting forces. The actual cutting load was computed from spindle load data and a friction load compensation algorithm. Collision and tool wear were detected by comparing the actual and virtual load, with the time synchronised by using tool position data. The system machined an automotive grill mould cavity for 34 hours without the supervision of a worker, because pre-simulation had stabilized the milling process and monitoring would have stopped the process if the actual load was different to the virtual load. Pre-simulation has been verified by thousands of mould makers and integrated with sensorless monitoring in an open CNC. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
42. Impact of chemical peeling combined with negative pressure on human skin.
- Author
-
Kim, S. J., Kang, I. J., Shin, M. K., Jeong, K. H., Baek, J. H., Koh, J. S., and Lee, S. J.
- Subjects
- *
CHEMICAL peel , *SKIN physiology , *HYDROXY acids , *SKIN disease treatment , *BIOENGINEERING - Abstract
Objective In vivo changes in skin barrier function after chemical peeling with alpha hydroxyacids ( AHAs) have been previously reported. However, the additional effects of physical treatment with chemical agents on skin barrier function have not been adequately studied. This study measured the degree of acute skin damage and the time required for skin barrier repair using non-invasive bioengineering methods in vivo with human skin to investigate the additional effect of a 4% AHA chemical jet accelerated at supersonic velocities. Methods Thirteen female subjects (average age: 29.54 ± 4.86 years) participated in this study. The faces of the subjects were divided into half according to the block randomization design and were then assigned to receive AHA peeling alone or AHA peeling combined with pneumatic pressure on each side of the face. Transepidermal water loss ( TEWL), skin colour and skin blood flow were evaluated at baseline and at 30 min, 2, 5 and 7 days after treatment. Results The TEWL and skin blood flow were significantly increased after 30 min in chemodermabrasion compared with chemical peeling alone ( P < 0.05). The TEWL and skin blood flow recovered to baseline after 2 days, and TEWL was significantly decreased at 7 days compared with chemical peeling alone ( P < 0.05). Conclusions Chemodermabrasion can temporarily impair skin barriers, but it is estimated that it can enhance the skin barrier function after 7 days compared to the use of a chemical agent alone. In addition, chemodermabrasion has a more effective impact in the dermis and relatively preserves the skin barrier. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
43. Ion mixing and thermochemical properties of tracers in Ag.
- Author
-
Ma, E., Kim, S.-J., Nicolet, M.-A., and Averback, R. S.
- Subjects
- *
IONS , *CHEMICAL elements , *SILVER , *DIFFUSION - Abstract
Presents a study which investigated the effect of the thermal spike mechanism for ion mixing of tracers in silver. Factors that promote thermal spike diffusion; Selection of tracer elements; Comparison of the thermal diffusion coefficients and tracer ion mixing efficiencies.
- Published
- 1988
- Full Text
- View/download PDF
44. Factors Delaying Organ Procurement After Declaration of Brain Death in Korea.
- Author
-
Yu, Y.-D., Kim, S.-J., Jang, Y.-S., Jung, S.-W., Han, J.-H., Jun, H., Jung, C.-W., and Kim, D.-S.
- Subjects
- *
PROCUREMENT of organs, tissues, etc. , *BRAIN death , *ELECTROENCEPHALOGRAPHY , *MEDICAL records - Abstract
Background Organ donation after brain death is a major source for obtaining transplantable organs for patients with end-stage organ disease. However, the time from declaring brain death to organ procurement is often longer than expected. Analyzing factors that delay organ procurement may help to prevent damage to organs from marginal and unstable donors and aid in preparation for recipient operation. The aim of this study was to examine factors associated with the interval between the time of declaring brain death and organ procurement. Methods Medical records of patients who underwent organ procurement after brain death from February 2009 to April 2015 were retrospectively reviewed. Results Of the 77 patients which were scheduled to undergo organ procurement, 68 eventually underwent procurement of ≥1 organ. The average time interval from 1st exam for brain death to organ procurement decreased from 1,248 minutes in 2009 to 910 minutes in 2015. Although not statistically significant, during the 6-year period, the time interval decreased from 1,105 minutes to 1,075 minutes in the latter half of the period ( P = .623). Organ procurement was extensively delayed most commonly owing to false negative electroencephalogram (EEG; 62.5%). Conclusions With increasing experience in dealing with brain death donors, the time interval from declaring brain death to organ procurement decreased. We suggest that an EEG be performed during the initial stages of examination for brain death to prevent unnecessary preparation of recipient operation owing to a false EEG test. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
45. Efficacy and possible mechanisms of topical tranexamic acid in melasma.
- Author
-
Kim, S. J., Park, J.‐Y., Shibata, T., Fujiwara, R., and Kang, H. Y.
- Subjects
- *
TRANEXAMIC acid , *MELANOSIS , *DRUG efficacy , *SKIN biopsy , *HUMAN skin color - Abstract
Background Tranexamic acid (TA) has been suggested as an effective treatment for melasma. Aim To investigate the effects and mechanism of action of topical TA in the treatment of melasma. Methods In this study, 23 participants with melasma applied a 2% TA formulation to the whole face for 12 weeks. Clinical effects were evaluated using the modified Melasma Area and Severity Index (mMASI) and a chromameter. Skin biopsies were obtained from 10 participants to evaluate pigmentation, vascularity and the expression levels of possible paracrine factors contributing to the effect of TA. Results Most of the participants had mild melasma, with mMASI of < 5. The mMASI scores significantly improved in 22 of 23 participants after application. The L* values were increased and the a* values were decreased in both lesional and perilesional normal skin. Fontana-Masson staining showed a significant decrease in melanin content in the epidermis. The number of CD31-positive vessels and the expression of the vascular endothelial growth factor both tended to decrease. Endothelin (ET)-1 was found to be downregulated with TA. Conclusions Topical TA is effective for melasma. This immunohistochemical study found that suppression of ET-1 could be one of the mechanisms of action of TA on melasma. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
46. Characterization of chemical doping of graphene by in-situ Raman spectroscopy.
- Author
-
Kim, S. J., Park, S. J., Kim, H. Y., Jang, G. S., Park, D. J., Ji-Yong Park, Soonil Lee, and Ahn, Y. H.
- Subjects
- *
DOPING agents (Chemistry) , *RAMAN spectroscopy , *GRAPHENE , *ACIDS , *RAMAN spectra - Abstract
We explored single-layer graphene and graphene field-effect transistors immersed in nitric acid using in-situ Raman spectroscopy. Two distinct stages were observed in the chemical doping process. The first stage involved blue shifts of the G and 2D peaks, whose saturation occurred rapidly with a time constant in the range of 10–25 s depending on the molar concentration of the acid. In the second stage, the intensity of the D peak, which was associated with structural defect formation, increased for a relatively long period of time. Since the major doping effects appeared during the first stage, the optimal doping conditions under which no noticeable structural defect formation occurred can be determined by monitoring the frequency shift. Transient doping concentrations along with structural defect densities were obtained from the Raman peak positions and intensities. We found that the doping-induced shift in the Dirac point in graphene field-effect transistors exhibited a fast response with respect to frequency shifts in the Raman spectra, which was attributed to the saturation of electrostatic gating effects. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
47. Evaluation of micro-organism-detaching efficacy from meat samples by spindle or stomacher treatment and quality analysis of suspensions.
- Author
-
Kim, S. ‐ J., Kim, D. ‐ K., and Kang, D. ‐ H.
- Subjects
- *
MEAT microbiology , *ROTATIONAL motion , *MEAT quality , *POLYMERASE chain reaction , *SUSPENSIONS (Chemistry) , *FOOD pathogens , *TURBIDITY - Abstract
Aims We investigated and compared the efficacy of a new apparatus for detaching micro-organisms from meat samples. Methods and Results The efficacy of Spindle and stomacher in detaching micro-organisms from meat samples was evaluated. Also, evaluation of appropriateness of suspensions generated by both methods for carrying out molecular biological analysis was implemented. A nearly identical correlation and high R2 were obtained between Spindle and stomacher in Aerobic Plate Count ( APC), and no significant differences were observed in detachment of three major foodborne pathogens. The suspension generated by the Spindle showed lower turbidity and total protein concentration. Also, significantly different threshold cycles were observed in Real-time PCR analysis using suspensions generated by both methods. Conclusions The Spindle shows nearly identical efficacy with stomacher treatment in detaching micro-organisms from meat samples. Furthermore, the high quality of suspensions generated by the Spindle, in terms of turbidity and total protein assay, allows for a lower threshold cycle than stomached suspension in Real-time PCR. Significance and Impact of the Study The Spindle could be an alternative method for detaching micro-organisms, yielding a higher quality of suspensions which may be better suited for further molecular microbiological analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
48. A phase II study of everolimus (RAD001), an mTOR inhibitor plus CHOP for newly diagnosed peripheral T-cell lymphomas.
- Author
-
Kim, S. J., Shin, D. -Y., Kim, J. S., Yoon, D. H., Lee, W. S., Lee, H., Do, Y. R., Kang, H. J., Eom, H. S., Ko, Y. H., Lee, S. H., Yoo, H. Y., Hong, M., Suh, C., and Kim, W. S.
- Subjects
- *
EVEROLIMUS , *CANCER relapse , *T-cell lymphoma , *COMBINATION drug therapy , *IMMUNOHISTOCHEMISTRY , *PATIENTS , *THERAPEUTICS - Abstract
Background: Everolimus, an oral mTOR inhibitor, has single-agent activity against relapsed lymphomas. Thus, we carried out a phase II study of everolimus in combination with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) as a first-line treatment for patients with peripheral T-cell lymphoma (PTCL) based on our phase I study results. Patients and methods: Participants (n = 30) received CHOP with 5 mg everolimus per day from day 1 to 14 every 21 days for a total of six cycles. The primary end point was the overall response rate (ORR), which included complete response (CR) and partial response (PR) to this regimen. Immunohistochemistry was used to evaluate the expression of phosphatase and tensin homology (PTEN) and phosphorylated S6 kinase (pS6K) as a response. Results: The objective response rate was 90% with CR (n = 17) and PR (n = 10). The CR rate was different among sub-types; angioimmunoblastic T-cell lymphoma (AITL, n = 3) had a CR whereas PTCL-not-otherwise specified and ALK-negative anaplastic large-cell lymphoma (ALCL) patients showed 63% (12/19) and 29% (2/7) of CR rate, respectively. This difference in CR rate among subtypes was associated with PTEN loss because PTEN loss was not seen in AITL but 33% of ALCL patients. The most common toxicity was hematological, with 80% of patients experiencing at least one event of grade 3/4 neutropenia, and 60% of patients had grade 3/4 thrombocytopenia. Conclusion: The everolimus plus CHOP was effective for PTCL patients, and its efficacy might be related with the preservation of PTEN. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
49. Improvement of Corrosion Properties of AL-4.08MG Alloy in Seawater by Two Step Anodizing in Electrolyte with Varied Concentration.
- Author
-
LEE, S. J. and KIM, S. J.
- Subjects
- *
ALUMINUM alloys , *CORROSION & anti-corrosives , *ANODIC oxidation of metals , *ELECTROLYTES , *SEAWATER , *CORROSION resistance , *CURRENT density (Electromagnetism) - Abstract
Aluminum is extremely active metal on the surface of which the oxide is instantly created when exposed to atmosphere. This naturally generated film has little industrial value as it has thickness as thin as 10 nm. Hence, oxide films are often made thick by electrochemical method. The characteristics of the films can be controlled by varying process parameters including composition, concentration, additives, solution temperature, voltage etc. These films have high hardness and excellent corrosion resistance. Therefore, they are receiving great amount of attention in both academic and industrial areas with their diverse applicability. In this paper, the optimal electrolyte concentration was investigated to produce oxide film with excellent corrosion resistance. The results reveal that Al2O3 oxide film was created on the surface for all tested electrolyte concentrations. Moreover, the films have a considerably lower corrosion current density than that of the substrate, implying excellent corrosion resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
50. Sensitizing Effects of Ti Alloying Contents on Damage Behavior of Austenitic Stainless Steel Exposed to Ultrasonic Vibratory Cavitation.
- Author
-
LEE, J. H. and KIM, S. J.
- Subjects
- *
AUSTENITIC stainless steel , *STAINLESS steel fatigue , *ULTRASONIC waves , *TITANIUM-aluminum alloys , *CAVITATION erosion , *MICROSTRUCTURE - Abstract
The cavitation damage characteristics of austenitic stainless steel with different concentrations of Ti were investigated. The microstructure of the alloys was observed with optical microscope to identify its correlation with cavitation resistance. Hardness of the alloys was measured to examine its contribution to cavitation damage. It was found that the microstructure played a more significant role in cavitation damage behavior of austenitic stainless steel with Ti than the hardness. The findings in this study revealed that Ti addition in austenitic stainless steel may present either a beneficial or detrimental effect on cavitation damage behavior, depending on the microstructural characteristics. In particular, Ti content of 1.0% represented the most deteriorated cavitation characteristics due to the formation of relatively coarse precipitates. Therefore, control of Ti concentration is essential for marine application of austenitic stainless steel. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.