• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2871-2876
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• 2022

The sensitivity of polymer-based capacitive relative humidity (RH) sensors after irradiation with neutrons, electrons and protons was measured. Degradation consists of the decreasing of the upper RH limit that can be measured. At the same time, low RH-level sensitivity is almost stable. After 30 krad of absorption dose, RH cut off is equal to 85% of max value, after 60 krad-40%. Degradation reduces after annealing which indicates high radiation sensitivity of the internal circuit in comparison to RH-sensing polymer film.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.3
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• pp.175-179
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• 2022

Magnetic arc extinguishing technology is effective as an extinguishing device for low-voltage direct current (DC) circuit breakers with a resistive load of ≤4 kW. The separation distance between the magnet and the electrical contact must be shortened to increase the magnetic arc extinguishing force. However, if the magnet is installed too close to the electrical contact points, the magnet is exposed to high temperatures due to the arc current generated when the load current is cut off and the magnetism is lost. To solve this problem, the effective magnetic flux density at the electrical contact can be maintained high by placing the arc extinguishing magnet in a tandem structure with the electrical contact point between them, and the proper separation distance between the contact points and the magnet can be maintained. In addition, an electric arc extinguishing technology that emits arc energy using a series circuit of diode and resistor is used to suppress the continuous arc voltage generated by the inductive load. For the proposed circuit breaker, the breaking characteristics are analyzed through the breaking test for the DC load of the 760 V level, the load power of 4 kW, and the time constant of 5 ms, and an appropriate arc extinguishing design guideline is proposed.

• Membrane and Water Treatment
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• v.13 no.2
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• pp.105-110
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• 2022

Al₂O₃ positively charged nanofiltration composite membrane was successfully prepared with aluminate coupling agent (ACA) as modifier, sodium bisulfite (NaHSO₃) and potassium persulfate (K₂S₂O₈) as initiator and methacryloyloxyethyl trimethylammonium chloride (DMC) as crosslinking monomer. The surface of the membrane before grafting and after polymerization were characterized by SEM and FT-IR. Three factor and three-level orthogonal experiments were designed to explore the optimal conditions for membrane preparation, and the optimal group was successfully prepared. The filtration experiments of different salt solutions were carried out, and the retention molecular weight was determined by polyethylene glycol (PEG). The results showed that the polymerization temperature had the greatest effect on the rejection rate, followed by the reaction time, and the concentration of DMC had the least effect on the rejection rate. The rejection rates of CaCl₂, MgSO₄, NaCl and Na₂SO₄ in the optimal group were 83.8%, 81.3%, 28.1% and 23.6% (average value), respectively. The molecule weight cut-off of 90% (MWCO) of the optimal group was about 460, which belongs to nanofiltration membrane.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.157-162
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• 2023

Elongated styloid syndrome (ESS) can present with myriad symptoms that mimic common features of orofacial pain, such as temporomandibular joint disorders (TMJDs), often causing a challenge and delay in diagnosis. We report the case of a 52-year-old male with a three-year history of non-painful clicking during jaw movement initially diagnosed as TMJD-related internal derangement. The patient presented with a history of annoying jaw sounds for three years, described as a popping sound without bilateral clicking or crepitation. Tinnitus and progressive hearing loss were observed in the right ear, and a hearing aid was recommended by an otolaryngologist. The patient was initially diagnosed with TMJD and managed accordingly; nevertheless, his symptoms persisted. Imaging revealed prominent bilateral styloid process elongation that exceeded the recognized cut-off level of >30 mm for elongation. The patient was informed of his diagnosis and its treatment but opted only for further swallowing and auditory assessments of his ear and nose symptoms. Clinicians should consider including ESS as a differential diagnosis in patients presenting with non-specific chronic orofacial symptoms for timely diagnosis and favorable clinical outcomes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8075-8081
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• 2014

Background: The classical inflammatory biomarker, C-reactive protein (CRP), has been identified to be related to progression of esophageal cancer. Some research showed that elevated pretreatment serum CRP indicated a poor prognosis, but results have been inconsistent. Materials and Methods: We searched the Medline, Embase and the Cochrane Central Search Library for suitable studies and a meta-analysis of eleven (1,886 patients) was conducted to examine the relationship between elevated serum CRP level and overall survival (OS) in esophageal cancer cases. Moreover, correlation analyses were conducted to assess links between pretreatment serum CRP level and tumor node metastasis (TNM) stage as well as T, N, M grade, respectively. Results: The pooled analysis showed that elevated pretreatment serum CRP level was significantly associated with poorer overall survival (HR 2.09, 95%CI 1.52-2.87, p<0.01). Subgroup analyses were conducted by "country", "cut-off value", "treatment" and "number of patients", and no single factor could alter the result. Elevated pretreatment serum CRP was significantly correlated with more advanced TNM stage and T, N, M grade respectively. Conclusions: Elevated pretreatment serum CRP levels are associated with poorer prognosis in esophageal cancer patients, and could serve as a useful biomarker for outcome prediction.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1881-1886
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• 2016

Background: CA125 is very helpful in treatment monitoring and detection of epithelial ovarian cancer (EOC) recurrence. However there is controversy as to its accuracy and optimal usage. What is the impact of the CA125 levels before primary surgery treatment to the survival of patients? This study aimed to detect any association of preoperative serum levels with prognosis and survival in EOC patients. Materials and Methods: Our cohort comprised EOC patients in Dr. Sardjito Hospital, Yogyakarta, Indonesia, who complied with follow up. To explore the effect of preoperative CA125 levels and other variables on survival Cox's regression models were applied. Results: A total of 90 cases of EOC who had surgery were available for follow up. The level of CA125 proved to be a prognostic factor for overall survival of EOC patients, with an adjusted HR of 4.10 (p = 0.03). Adjuvant chemotherapy was another prognostic factor, 1 - 2 cycles having an adjusted HR of 0.17 (p = 0.04) and 3 - 8 cycles HR 0.39 (p = 0.06). Other factors such as age of patients adjusted HR 1.54 (p = 0.32), moderate differentiation (adjusted HR 1.61, p = 0.51) poor differentiation (adjusted HR 3.41, p = 0.15), and stage of disease (adjusted HR 1.98,p=0.27) were statistically not significant. However, this might have been because the power of the study was low. Conclusions: Preoperative level of CA125 is a prognostic factor for overall survival in EOC patients. The best cut-off for prognostic classification of CA125 serum level is 70 U/ml.

• The KSFM Journal of Fluid Machinery
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• v.7 no.1 s.22
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• pp.17-23
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• 2004

Aeroacoustic characteristics of sirocco fan used in Over-The-Range (OTR) has been analyzed in this paper. A microwave hood combination over the gas range is short for the OTR. The flow phenomena of the double-sided sirocco fan was analyzed numerically and experimentally by using commercial code and three dimensional PIV for flow visualization. Also, microphone array is used in order to understand acoustic characteristics of OTR. Two dimensional unsteady flow and acoustic simulation is tried to qualitatively estimate the effects of tonal noise and broadband noise on the overall sound pressure level. It is found that tonal sound is generated from the strong interaction between the impeller and cutoff while broadband sound is generated from the strong secondary flows along the scroll surface. To reduce the noise level, the V-shape cut-off was applied to improve the sound quality by reducing tonal noise. So the peak noise at BPF (Blade Passing Frequency) was almost reduced. The shape of flow-guide to suppress the secondary flow over the scroll surface was carefully checked. It is found that this affects flow pattern at the fan exit and reduces the broad band noise. Through this numerical and experimental study, the sound pressure level was lowered by 4dBA compared to that of the previous fan at the operating point.

• Korean Journal of Exercise Nutrition
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• v.25 no.3
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• pp.16-22
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• 2021

[Purpose] Exercise-associated hyponatremia (EAH) is a well-known condition among endurance athletes at low altitudes. The incidence of EAH during ultramarathons at high altitudes warrants further investigation. This prospective observational study was conducted on the participants of the Leadville Trail 100 run, a 161-km race held at a high altitude (2,800 m-3,840 m). [Methods] Venous blood samples were collected before and immediately after the race. The participants completed an electronic survey after the race. Our main outcome measure was the post-race serum sodium ([Na⁺]) level. [Results] Of the 672 athletes who started the race, 351 (52%) successfully completed the event within the 30-hour cut-off. Post-race blood samples were collected from 84 runners (66 finishers). Both pre- and post-race blood samples were collected from 37 participants. Twenty percent of the post-race participants had EAH. Only one post-race participant had a [Na⁺] level of <130 mmol/L. All participants with EAH were asymptomatic. One participant had an abnormal pre-race [Na⁺] level (134 mmol/L). Female participants had a significantly higher rate of EAH than male participants (40% vs. 16%; p=0.039). Age, body mass index, weight changes, race completion status, nonsteroidal anti-inflammatory drug use, and urine specific gravity were not associated with the development of EAH. Lower postrace [Na⁺] levels were associated with higher serum creatine kinase values (R²=0.1, p<0.005). [Conclusion] High altitude (3,840 m peak) does not appear to enhance the incidence of EAH after an ultramarathon footrace. This suggests that ambient temperature (low temperatures reduce risk), sex (female predilection), endurance running, and overhydration are more prominent risk factors for EAH than high altitude.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.10
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• pp.14-22
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• 2010

The source/channel/drain regions are formed by ion implantation with different dopant types of $n^+/p^{(+)}/n^+$ in the fabrication of the conventional n-type metal-oxide-semiconductor field effect transistor(NMOSFET). In implementing the ultra-small devices with channel length of sub-30 nm, in order to achieve the designed effective channel length accurately, low thermal budget should be considered in the fabrication processes for minimizing the lateral diffusion of dopants although the implanted ions should be activated as completely as possible for higher on-current level. Junctionless (JL) MOSFETs fully capable of the the conventional NMOSFET operations without p-type channel for enlarging the process margin are under researches. In this paper, the optimum design of the JL MOSFET based on silicon nanowire (SNW) structure is carried out by 3-D device simulation and the basic radio frequency (RF) characteristics such as conductance, maximum oscillation frequency($f_{max}$), current gain cut-off frequency($f_T$) for the optimized device. The channel length was 30 run and the design variables were the channel doping concentration and SNW radius. For the optimally designed JL SNW NMOSFET, $f_T$ and $f_{max}$ high as 367.5 GHz and 602.5 GHz could be obtained, respectively, at the operating bias condition $V_{GS}$ = $V_{DS}$ = 1.0 V).

• Korean Journal of Head & Neck Oncology
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• v.26 no.1
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• pp.14-18
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• 2010

Objectives : We evaluated the use of FDG PET/CT for the identification of cervical nodal metastases of SCC of the oral cavity and oropharynx with histological correlation. Material and Methods : We reviewed 46 medical records, from January 2004 to July 2007, of patients who underwent FDG PET/CT and CT/MRI for SCC of the oral cavity and oropharynx before surgery. We recorded the lymph node metastases according to the neck level affected and the system used for the imaging-based nodal classification. Results : The FDG PET/CT had a sensitivity of 75.6% and a specificity of 96.7% ; it had a higher sensitivity than the CT/MRI for identification of cervical metastases on the side of the neck(26/28 vs. 20/28, p=0.031) and at each of the cervical levels(34/45 vs. 26/45, p=0.008). There was a significant difference in the $SUV_{max}$ between the benign and malignant cervical lymph nodes($3.31{\pm}3.23$ vs. $4.22{\pm}2.57$, p=0.028). The receiver-operating-characteristic (ROC) curve analysis for differentiating the benign from the malignant cervical lymph nodes, showed that the area under the curve(AUC) of the FDG PET/CT was 0.775. The cut-off value for the $SUV_{max}$ was 2.23 based on the ROC curve. There was a significant correlation between the $SUV_{max}$ and the size of the cervical lymph nodes(Spearman r=0.353, p=0.048). Conclusion : FDG PET/CT images were more accurate than the CT/MRI images. In addition, the $SUV_{max}$ cut-off values were important for evaluating cervical the cervical nodes in the patients with SCC of the oral cavity and oropharynx.