• 대한의용생체공학회:의공학회지
• /
• 제30권5호
• /
• pp.418-427
• /
• 2009

As many people are westernizing their life style and food consumption habits, a number of patients who have malignant tumors which grow very rapidly and hazardously destroy the human body are increasing. Ultrasonic hyperthermia is not only one of the tumor treatment methods which employs the non-radioactive ultrasonic waves to increase the temperature at the tumor region up to $40\sim45^{\circ}C$ to destroy and suppress tumor cells but also has been proved by many studies. Due to the rapid development of High Intensity Focused Ultrasound(HIFU), the ultrasound hyperthemia extensively boosts its applications in clinical field. For those reasons, Computed simulation factor should be needed before inspection to patients. To prove efficiency of ultrasonic hyperthermia, precise acoustic field measurement considering tissue characteristics and a heating experiment with tissue mimicking material phantom were conducted for effectiveness of simulation program. Finally, in this study, the computer simulation program verified the anticipated temperature effects induced by ultrasound hyperthermia. In the near future, it is hoped that this simulation program could be utilized to improve the efficiency of ultrasound hyperthermia.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제20권4호
• /
• pp.7-16
• /
• 2014

Purpose : The purpose of this study was to examine the nurses' needs for the spatial composition of geriatric hospital. Methods : The survey method was used for collecting the data. The subjects were 110 nurses who worked at 6 geriatric hospitals in Busan. They answered the questionnaire by the self-administered method. The questionnaire consisted of items which asked the spatial composition of patient room, bathroom, dining space, resting space, care-givers' room, and garden. Results : 1) The patient room using a bed on ondol floor would be useful. Also, it would be desirable that most patient rooms consisted of 4 or 6 persons per patient room and the others were 1 or 2 persons per room. 2) The bathroom for only patients and the shower room for their families or care-givers are needed in the geriatric hospital. 3) The dining room for patients in each floor would be useful to old patients. In addition to that, the cafeteria for their families or care-givers are needed. 4) The resting space for patients and their families, for the staff, and for care-givers are needed. 5) The personal locker and refrigerator are necessary fixtures in care-givers' room. Also, table, sofa, sink, and shower booth are also needed. 6) On the base of activities of care-givers, the space for preserving, washing, and heating foods are needed. Also, the storage space for personal items and the fitting space are needed. Implications : The results of this study would be the fundamental data for space planning of the geriatric hospital.

• 한국전기전자재료학회논문지
• /
• 제23권6호
• /
• pp.497-501
• /
• 2010

Nano structure $Bi_2Te_3$ films were deposited on (100) GaAs substrates using a modified MOCVD system and the effect of growth parameters on the structural properties were investigated. Different from conventional MOCVD systems, our reactor consist of pressure control unit and two heating zones ; one for formation of nano-sized particles and the other for the growth of nano particles on substrates. By using this instrument we successfully grow $Bi_2Te_3$ films with nano-grain size. The film grown at high reactor pressure has large grain size. On the contrast, the grain size decreases with a decrease in pressure of the reactor. Here, we introduce new growth methods of nano-grain structured $Bi_2Te_3$ films for high thermoelectric figure of merit.

• 한국진공학회지
• /
• 제20권5호
• /
• pp.322-326
• /
• 2011

상부 전극에 RF power 가 직접 인가되는 capacitively coupled plasma source를 이용한 oxide layer etching 공정은 현재 반도체 제조 공정에서 매우 유용하게 사용되고 있는 방식이다. 그러나 디바이스의 사이즈가 점점 작아지면서 공정을 진행하기 위한 RF power도 커지고, plasma ignition 되는 electrode 사이의 간격도 점점 좁아지는 기술적 변화가 이루어지고 있다. 이러한 H/W의 변화에 따라 예상치 못한 문제들로 공정을 적용하는데 많은 문제점이 발생하고 있는데, 공정 진행 시에 plasma의 영향으로 인한 electrode의 온도 변화도 그 중 하나이다. 이러한 온도 변화로 인해 wafer to wafer의 공정 진행 결과가 서로 다르게 나타나게 하는 문제가 야기되고 있다. 아래의 내용에서는 상부 electrode의 온도 변화에 따른 etch 특성을 연구하고, 이를 개선할 수 있는 방법에 대해 논하고자 한다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.277-277
• /
• 2013

The epitaxial graphene on the 4H- or 6H-SiC(0001) surface has been intensively studied due to the possibility of wafer-scale growt. However the existence of interface layer (zero layer graphene) and its influence on the upper graphene layer have been considered as one of the main obstarcles for the industrial application. Among various methods tried to overcome the strong interaction with the substrate through the interface layer, it has been proved that the hydrogen intercalation successfully passivate the Si dangling bond of the substrate and can produce the quasi-free standing epitaxial graphene (QFEG) layers on the siC(0001) surface. In this study, we report the results of the angle-resolved photoemission spectroscopy (ARPES) and Raman spectroscopy for the QFEG layers produced by ex-situ and in-situ hydrogen intercalation.From the ARPES measurement, we confirmed that the Dirac points of QFEG layers exactly coincide with the Fermi level. The band structure of QFEG layer are sustainable upon thermal heating up to 1100 K and robust against the deposition of several metals andmolecular deposition. We also investigated the strain of the QFEG layers by using Raman spectroscopy measurement. From the change of the 2D peak position of graphene Raman spectrum, we found out that unlike the strong compressive strain in the normal epitaxial graphene on the SiC(0001) surface, the strain of the QFEG layer are significantly released and almost similar to that of the mechanically exfoliated graphene on the silicon oxide substrate. These results indicated that various ideas proposed for the ideal free-standing graphene can be tested based on the QFEG graphene layers grown on the SiC(0001) surface.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.669-669
• /
• 2013

Hierarchical N doped TiO2 nanostructured catalyst with micro, meso and macro porosity have been synthesized by a facile self-formation route using ammonia and titanium isopropoxide precursor. The samples were calcined in different calcination temperature ranging from $300^{\circ}C$ to $800^{\circ}C$ at slow heating rate ($5^{\circ}C$/min) and designated as NHPT-300 to NHPT-800. $TiO_2$ nanostructured catalyst have been characterized by physico-chemical and spectroscopy methods to explore the structural, electronic and optical properties. UV-Vis diffuse reflectance spectra confirmed the red shift and band gap narrowing due to the doping of N species in TiO2 nanoporous catalyst. Hierarchical macro porosity with fibrous channel patterning was observed (confirmed from FESEM) and well preserved even after calcination at $800^{\circ}C$, indicating the thermal stability. BET results showed that micro and mesoporosity was lost after $500^{\circ}C$ calcination. The photocatalytic activity has been evaluated for methanol oxidation to formaldehyde in visible light. The enhanced photocatalytic activity is attributed to combined synergetic effect of N doping for visible light absorption, micro and mesoporosity for increase of effective surface area and light harvestation, and hierarchical macroporous fibrous structure for multiple reflection and effective charge transfer.

• 한국가스학회지
• /
• 제24권3호
• /
• pp.40-46
• /
• 2020

텨셔리부틸퍼옥시말레이트(Tertbutylperoxymaleate : TBPM)는 인조대리석 제조에 사용되는 개시제 조성물의 원료로 유기과산화물의 일종이다. 본 연구에서는 시차주사열량계(DSC)를 이용하여 공기 및 질소 분위기에서 TBPM의 열분해특성을 평가하였다. TBPM은 반응 분위기와 관계없이 130 ℃ 이하에서 급격한 분해에 의한 발열을 나타냈다. 그리고 동적방법을 이용한 속도론적 평가에서 방법에 따라서 203~217 kJ/mol의 활성화에너지를 보였으며, Model-free 방법에 의한 분석에서는 118~232 kJ/mol의 활성화에너지를 갖는 것으로 평가되었다. 그리고 도출된 활성화에너지를 이용하여 24시간 이내에 최대발열속도에 도달하는 온도인 ADT₂₄는 (80~95) ℃로 평가되었다.

• 조명전기설비학회논문지
• /
• 제20권8호
• /
• pp.71-79
• /
• 2006

페놀수지 표면에서의 트래킹 방전에 대한 화재원인을 규명하기 위하여 검증실험, FT-IR, DTA, 사진촬영 등의 다양한 방법으로 분석하였다. 페놀수지는 유기질 절연재료 중 저전압기기의 외함재료로 가장 많이 이용된다. 본 실험에서는 외부열에 의해 탄화질로 변화되는 것과 전기적 원인에 의해 흑연질이 되는 것에 대해 재료분석을 통한 방법으로 규명하였다. FT-IR을 이용하여 표면방전에 의해 탄화된 시료는 $150[^{\circ}C]$에서 열처리된 시료로부터 약 $1730[cm^{-1}]$ 부분과 $1680[cm^{-1}]$부근의 적외선흡광피크를 확인하였다. DTA를 이용하여 페놀수지는 약 $450[^{\circ}C]$ 부근에서 발열피크가 나타났으며, 방전에 의해 탄화된 재료는 약 $610[^{\circ}C]$ 부근에서 발열피크가 나타나는 것을 알 수 있었다. 이로써 전기화재원인을 규명하는 것이 가능하게 되었다. 이 결과들로부터, 전기화재의 예방과 국민의 생명과 재산을 지키는 중요한 자료가 될 것으로 기대된다.

• 한국분말재료학회지
• /
• 제22권5호
• /
• pp.356-361
• /
• 2015

Fe-30 wt% TiC composite powders are fabricated by in situ reaction synthesis after planetary ball milling of (Fe, $TiH_2$, Carbon) powder mixture. Two sintering methods of a pressureless sintering and a spark-plasma sintering are tested to densify the Fe-30 wt% TiC composite powder compacts. Pressureless sintering is performed at 1100, 1200 and $1300^{\circ}C$ for 1-3 hours in a tube furnace under flowing argon gas atmosphere. Spark-plasma sintering is carried out under the following condition: sintering temperature of $1050^{\circ}C$, soaking time of 10 min, sintering pressure of 50 MPa, heating rate of $50^{\circ}C/min$, and in a vacuum of 0.1 Pa. The curves of shrinkage and its derivative (shrinkage rate) are obtained from the data stored automatically during sintering process. The densification behaviors are investigated from the observation of fracture surface and cross-section of the sintered compacts. The pressureless-sintered powder compacts are not densified even after sintering at $1300^{\circ}C$ for 3 h, which shows a relative denstiy of 66.9%. Spark-plasma sintering at $1050^{\circ}C$ for 10 min exhibits nearly full densification of 99.6% relative density under the sintering pressure of 50 MPa.

• The Korean Journal of Pain
• /
• 제31권2호
• /
• pp.102-108
• /
• 2018

Background: Nefopam is a non-opioid, non-steroidal analgesic drug with fewer adverse effects than narcotic analgesics and nonsteroidal anti-inflammatory drugs, and is widely used for postoperative pain control. Because nefopam sometimes causes side effects such as nausea, vomiting, somnolence, hyperhidrosis and injection-related pain, manufacturers are advised to infuse it slowly, over a duration of 15 minutes. Nevertheless, pain at the injection site is very common. Therefore, we investigated the effect of warmed carrier fluid on nefopam injection-induced pain. Methods: A total of 48 patients were randomly selected and allocated to either a control or a warming group. Warming was performed by diluting 40 mg of nefopam in 100 ml of normal saline heated to $31-32^{\circ}C$ using two fluid warmers. The control group was administered 40 mg of nefopam dissolved in 100 ml of normal saline stored at room temperature ($21-22^{\circ}C$) through the fluid warmers, but the fluid warmers were not activated. Results: The pain intensity was lower in the warming group than in the control group (P < 0.001). The pain severity and tolerance measurements also showed statistically significant differences between groups (P < 0.001). In the analysis of vital signs before and after the injection, the mean blood pressure after the injection differed significantly between the groups (P = 0.005), but the heart rate did not. The incidence of hypertension also showed a significant difference between groups (P = 0.017). Conclusions: Use of warmed carrier fluid for nefopam injection decreased injection-induced pain compared to mildly cool carrier fluid.