• 한국가스학회지
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• 제4권1호
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• pp.16-25
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• 2000

스틸렌 공중합체의 열적특성과 독성인자를 평가하기 위하여 활성화 에너지, 물리적 특성 및 마취성 기체와 같은 독성물질의 발생가능성에 대하여 조사하였다 고온 분해시에 Kissinger법과 DSC법에 의해 계산된 활성화 에너지는 25${\~}$50 Kcal/mol이었다. 이것은 화재발생가능성에 대하여 좋은 정보가 될 것이다 FED계산으로부터 PS, SAN 및 ABS에 대한 $LC_{50}$의 값은 8,580, 265 및 308 $mg/m^3$이 되었다. FT-IR에 의해 분석한 열분해 반응의 메카니즘은 측쇄반응이 아니고 주쇄반응이었다.

• 미생물학회지
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• 제23권1호
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• pp.25-33
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• 1985

Cellulomonas flavigena KIST 321이 생산하는 균체외 cellulose 분해효소를 gel filtration법과 ion-exchange chromatography법으로 3종의 다른 효소를 분리하여 이들을 A, B, 및 C 효소로 명명하였다. 분리된 각 효소를 결정적 기질에 처리하여 일어나는 기질의 구조변화를 적회전 분광법과 X-ray crystallography법으로 측정하여 다음 결론을 얻었다. B효소는 결정성 cellulosem이 구성단위인 glucopyranose의 불안정화로 그 결정도를 감소시키는 $C_1$형의 효소이며 A 및 C 효소는 $C_x$형의 효소로 B 효소의 반응생성물에 작용하여 glucose를 생산하였다. 이들 각 효소의 작용에서 본균의 cellulase의 작용기작을 고찰하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9159-9164
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• 2014

Background: In this study eugenol (EU) loaded nanoemulsions (NEs) emulsified with modified starch were prepared and their apoptotic potential against liver and colon cancer cells was examined in comparison with bulk EU. Materials and Methods: We prepared stable EU loaded NEs whcih were characterized by dynamic light scattering, centrifugation and gas chromatography. Furthermore, cell viability was determined using MTT assay, and apoptosis and cell cycle analysess by flow cytometry. Results: HB8065 (liver) and HTB37 (colon) cells when treated with EU:CA NEs demonstrated greater apoptotic cells percentages as evidenced by microscopic images and flow cytometric evaluations. It was observed that EU and EU:CA NE induced apoptosis in both cell lines via reactive oxygen species (ROS) generation. Conclusions: The present study demonstrated that ROS plays a critical role in EU and EU:CA NE induced apoptosis in HB8065 and HTB37 cells. This is the first report on the antiproliferative mechanisms of EU loaded NE.

• Journal of information and communication convergence engineering
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• 제1권4호
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• pp.183-188
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• 2003

The $4^{th}$ generation mobile communications, through several radio access networks such as WLAN, Bluetooth, UMTS, GPRS, CDMA 1X, and IMT-2000 in the same area offering different type of coverage, will support interactive multimedia services in additions to wider bandwidths, higher bit rates, and service portability. Regardless of various radio access networks, they will also support robust security mechanisms, as well as seamless mobility and common authentication. In this paper, we give an overview of WLAN security and examine its security problems. We also explain the enhanced security schemes, such as port-based authentication, EAP, and IEEE 802.1X. For secure wireless communications, several possible security solutions are offered and evaluated in various respects to improve WLAN security. This paper will make a contribution to provide more secure wireless communications to cellular operators embracing WLAN technology as a means to generate new revenues based on data services.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1637-1641
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• 2016

Oxaliplatin, a third generation novel platinum compound is the most effective first line chemotherapeutic agent for colorectal cancer (CRC) in combination with 5FU and leucovorin. It is indicated for pancreatic, gastric and testicular cancers combined with bevacuzimab, capecitabine, irinotecan and other cytotoxic agents. However, moderate to severe hypersensitivity reactions (HSR) during or after oxaliplatin infusion usually require cessation of chemotherapy or substitution of the key therapeutic drug which largely interferes with improved patient prognosis. This mini- review showcases recent and accepted opinions/approaches in oxaliplatin induced HSR management. Physicians and oncologists have varying attitudes regarding the decision to rechallenge the patient after an HSR experience, efficacy of desensitization protocols, effectiveness and selection of drugs for premedication and possibilities of cross sensitivity to other platinum agents (e.g. carboplatin). A brief insight into underlying molecular mechanisms and clinical manifestations of oxaliplatin induced HSR is offered. We have also discussed the management of oxaliplatin induced HSR and risk stratification for a successful and complete chemotherapeutic plan.

• 마이크로전자및패키징학회지
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• 제29권2호
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• pp.53-58
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• 2022

One of the most promising emerging technologies for the next generation of nonvolatile memory devices based on resistive switching (RS) is the resistive random-access memory mechanism. To date, RS effects have been found in many transition metal oxides. However, no clear evidence has been reported that ZnO-based resistive transition mechanisms could be associated with strong correlation effects. Here, we investigated N, F-co-doped ZnO (NFZO), which shows bipolar RS. Conducting micro spectroscopic studies on exposed surfaces helps tracking the behavioral change in systematic electronic structural changes during low and high resistance condition of the material. The significant difference in electronic conductivity was observed to attribute to the field-induced oxygen vacancy that causes the metal-insulator Mott transition on the surface. In this study, we showed the strong correlation effects that can be explored and incorporated in the field of multifunctional oxide electrons devices.

• 대한신경집중치료학회지
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• 제7권2호
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• pp.104-110
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• 2014

Background: Cefepime is a fourth-generation cephalosporin widely used for empiric treatment of severe infections. Neurotoxicity by cefepime have been reported due to γ-aminobutyric acid A receptor inhibition or other mechanisms. The aim of this study was to evaluate the risk factors for cefepime-induced neurotoxicity between group showing cefepime-induced neurotoxicity and group without neurotoxicity. Methods: From Jan 2005 to June 2010, a total of 2,461 patients (older than 20) who used cefepime were considered in this study. We compared patients who developed cefepime-induced neurotoxicity (patient group, n=21) to patients who had no cefepime-induced neurotoxicity (control group, n=31). We analyzed demographic, underlying diseases, and metabolic parameters before cefepime treatment and during cefepime treatment between the two groups. Statistical analysis was performed using SPSS 18 software. Results: Of the total 2461 patients, 21 (0.85%) were diagnosed with cefepime-induced neurotoxicity. Impaired glomerular filtration rate (GFR at 15-30 ml/min) before cefepime use were significantly (P<0.05) higher risk for developing cefepime-induced neurotoxicity in patient group compared to that in the control group. Age, sex, and other metabolic parameters except GFR before and during, usage of cefepime did not show any statistical difference between the two groups. Conclusion: The present study revealed that cefepime-induced neurotoxicity was prone to develop in patients with impaired renal function before cefepime usage.

• 한국전기전자재료학회논문지
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• 제36권6호
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• pp.620-626
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• 2023

Energy harvesting technology, which converts wasted energy sources in everyday life into usable electric energy, is gaining attention as a solution to the challenges of charging and managing batteries for the driving of IoT sensors, which are one of the key technologies in the era of the fourth industrial revolution. Hybrid energy harvesting technology involves integrating two or more energy harvesting technologies to generate electric energy from multiple energy conversion mechanisms. In this study, a hybrid energy harvesting device called TMPPEG (thermo-magneto-piezoelectric-pyroelectric energy generator), which utilizes low-grade waste heat, was developed by incorporating PVDF polymer piezoelectric components and optimizing the system. The variations in piezoelectric output and thermoelectric output were examined based on the spacing of the clamps, and it was found that the device exhibited the highest energy output when the clamp spacing was 2 mm. The voltage and energy output characteristics of the TMPPEG were evaluated, demonstrating its potential as an efficient hybrid energy harvesting component that effectively harnesses low-grade waste heat.

• 대한기계학회논문집B
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• 제27권12호
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• pp.1655-1666
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• 2003

It is experimentally well-known that high anisotropies of the turbulent flow field are dominant inside the tip leakage vortex, which is attributable to a substantial proportion of the total loss and constitutes one of the dominant mechanisms of the noise generation. This anisotropic nature of turbulence invalidates the use of the conventional isotropic eddy viscosity turbulence models based on the Boussinesq assumption. In this study, to check whether an anisotropic turbulence model is superior to the isotropic ones or not, the results obtained from the steady-state Reynolds averaged Navier-Stokes simulations based on the RNG k-$\varepsilon$ model and the Reynolds stress model (RSM) are compared with experimental data for two test cases: a linear compressor cascade and a forward-swept axial-flow fan. Through this comparative study of turbulence models, it is clearly shown that the RSM, which can express the production term and body-force term induced by system rotation without introducing any modeling, should be used to predict quantitatively the complex tip leakage flow, especially in the rotating environment.

• 한국소음진동공학회논문집
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• 제13권4호
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• pp.258-265
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• 2003

This paper suggests the noise reduction method of the engine cooling fan. The fan noise contribution to the OASPL of engine room was estimated and the noise source was identified for the rotating fan by sound intensity method. And the program for Predicting the noise spectrum of axial flow fan was also developed. The radiated acoustic pressure is expressed in terms of discrete frequency noise Peaks at BPF and its harmonics and the line spectrum at the broad band by the proposed noise generation mechanisms. In this Paper, it Is shown that the comparison of the measured and calculated noise spectra of fan validates the noise predicting program. And this paper presents the characteristics of the fan noise in order to modify the design parameters. Accordingly, the design parameters were determined for the noise reduction of the fan.