• Journal of Korean Neurosurgical Society
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• v.55 no.3
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• pp.142-147
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• 2014

Objective : A thoracolumbar burst fracture is usually unstable and can cause neurological deficits and angular deformity. Patients with unstable thoracolumbar burst fracture usually need surgery for decompression of the spinal canal, correction of the angular deformity, and stabilization of the spinal column. We compared two struts, titanium mesh cages (TMCs) and expandable cages. Methods : 33 patients, who underwent anterior thoracolumbar reconstruction using either TMCs (n=16) or expandable cages (n=17) between June 2000 and September 2011 were included in this study. Clinical outcome was measured by visual analogue scale (VAS), American Spinal Injury Association (ASIA) scale and Low Back Outcome Score (LBOS) for functional neurological evaluation. The Cobb angle, body height of the fractured vertebra, the operation time and amount of intra-operative bleeding were measured in both groups. Results : In the expandable cage group, operation time and amount of intraoperative blood loss were lower than that in the TMC group. The mean VAS scores and LBOS in both groups were improved, but no significant difference. Cobb angle was corrected higher than that in expandable cage group from postoperative to the last follow-up. The change in Cobb angles between preoperative, postoperative, and the last follow-up did not show any significant difference. There was no difference in the subsidence of anterior body height between both groups. Conclusion : There was no significant difference in the change in Cobb angles with an inter-group comparison, the expandable cage group showed better results in loss of kyphosis correction, operation time, and amount of intraoperative blood loss.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.123-123
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• 2010

The hydrophobic coating for multi-walled nanotubes was treated with toluene and trimethylchlorosilane glow discharge plasma under low pressure, and the hydrophobic surface of the treated MWCNT was investigates. In order to investigate the effects of -CH components from the toluene and TMCS glow plasma, we conducted on the total surface free energies of the MWCNT powder, which was calculated by measuring the contact angle between the cushion of MWCNT powder and the probe liquids. The total surface free energies were determined by Owens-Wendt equation and drastically decreased.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.256-256
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• 2011

Using plasmas, hydrophobic surfaces are made on various substances such as polyimide films, filter paper, cotton clothes and multi-walled carbon nanotube (MWCNT) with hexamethyldisiloxane (HMDSO), trimethylchlorosilane (TMCS) and toluene reagents. Plasmas are easily and rapidly to change surface of hydrophilic materials into hydrophobic. We have also optimized processing time and maximized contact angle for super-hydrophobicity of MWCNT. Contact angles have been calculated by measuring between substance and probe liquid, and total surface free energies are determined by the Owens-Wendt equation. Figure 1 shows the measured contact angles with time and ratio of reagents on MWCNT.

• Journal of the Korean Ceramic Society
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• v.36 no.11
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• pp.1189-1197
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• 1999

Low-density silica gel monolith was synthesized at ambient pressure by surface modification with TMCS and sub-sequent heat treatment. The mechanical thermal and optical properties of gel were studied. Compressive strength and modulus of compression of 350$^{\circ}C$-heated gel with the density of 0.24g/cm3 were 250kPa and 0.2MPa respectively. The thermal conductivity of silica gels synthesized at ambient pressure exhibited 0.02 W/m$.$K for the density of 0.24g/cm3 which is similar to that of the gel via supercritical drying and their main thermal transfer mechanism is considered to be solid and radiation conduction at room temperature. Ambient-dried silica gels were transparent blue showing about 60% of transmittance in the wavelength of 1500-2100nm and typical absorption bands of existing bonds under heat treatment at 350$^{\circ}C$. Medium scale monolity(${\Phi}$=50mm) at ambient pressure could be successfully prepared through total 5-month process period.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.1
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• pp.79-86
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• 1994

Food quality in food processing and storage were affected by the kinds of phenolics involved. To analyze phenolics of Chebulae Fructus by the way of GC-MSm methylation and trimethylsilyation(TMS) are necessary. The methods of methylation were dimethyl sulfate method and diazomethane method. so this study was undertaken to research the better methylation method before measuring GC-MS. But dimethyl sulfate method of methylation was not sufficient to analyze phenolics. So the phenolics of Chebulae Fructus were analyzed by the diazomethane methylation method and TMS with the pyridine, N-O-bis-trimethylsilyl-acetamide(BSTFA) and trimethylchlorosilane(TMCS). With the exception of pyrogallol and phloroglucinol in insoluble phenolics of Chebulae Fructus, the greater part of phenolics. analysis could be analyzed by GC-MS in company with diazomethane methylation method and TMS.

• Bulletin of the Korean Chemical Society
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• v.19 no.2
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• pp.194-196
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• 1998

The metabolism of dromostanolone (2α-methyl-5α- androstan-17β-ol-3-one) was studied in three adult volunteers after oral dose of 20 mg. Solvent extracts of urine obtained after enzyme hydrolysis were derivatized with MSTFA/TMCS and MSTFA/TMIS. The structures of intact drug and its metabolites were determined by gas chromatography/mass spectrometry (GC/MS) in electron impact (EI) mode. The major metabolite (2α-methyl-5α- androstan-3α-ol-17-one), its 3β-epimer, parent compound, and several hydroxylated metabolites including intact drug were detected by comparing total ion chromatograms of control urine with that of the administered sample. Two epimers of 2α-methyl-5α- androstan-3,17β-diol were detected using selected ion monitoring. The maximum excretion of dromostanolone and 2α-methyl-5α- androstan-3α-ol-17-one was reached in 6.2-15 hr. The half-life of intact dromostanolone was 5.3 hr. About 3.0% of the administered amount was found to be excreted within 95 hr as unchanged form.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.275.1-275.1
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• 2003

Because people who take more than two drugs have increases, a simple and sensitive method for the simultaneous analysis of amphetamine, methamphetamine and nalbuphine in urine was developed. After alkalinization of the urine samples with 6 N-NaOH, the analytes were extracted using ethyl acetate, derivatized with MSTFA : TSIM : TMCS (= 100 : 2 : 5) prior to gas chromatography-mass spectrometry(GC-MS) analysis with selected ion monitoring. (omitted)

• Analytical Science and Technology
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• v.22 no.5
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• pp.407-414
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• 2009

A simultaneous determination method for cholesterol, lanosterol and desmosterol was developed using gas chromatography/mass spectrometry. Urine was enzymatically hydrolyzed with ${\beta}$-glucuronidase/arylsulfatase. Samples were prepared using extractions with a mixture of ethyl acetate-hexane (2:3, v/v), followed by derivatization with a mixture of MSTFA/TMSI/TMCS (100:2:5 v/v/v). All analyses were performed using GC/MS in selective ion monitoring mode. Good linearities ($r^2=0.998{\sim}0.999$) in calibration curve and a satisfactory recovery (80.0%~113%) were achieved. Accuracy and precision values within ${\pm}15%$ in the concentration range of 5 to 200 ng/mL were also observed for all compounds. The developed method was applied to pravastatin-treated (70 and 250 mg/kg/day for 7 days, oral) hyperlipidemia rats. Those sterols were significantly lower in drug-treated rats compared to the controls, which justifies the drug efficacy. Therefore, these results indicate that the developed method was successfully applied to examine statin drug efficacy with urine sample.

• Corrosion Science and Technology
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• v.18 no.6
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• pp.232-242
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• 2019

In this study, hydrophobically modified fumed silica was added to the PVDF coating to improve corrosion protection performance. Two types of silane modifiers, trimethylchlorosilane (TMCS) and hexamethyldisilazane (HMDZ), were used for hydrophobic modification of the fumed silica. The composition of modified fumed silica was analyzed by Fourier transform infrared, X-ray photoelectron spectroscopy, and elemental analysis. The dispersion of modified fumed silica in the PVDF coating was observed by the transmission electron microscopy, and the hydrophobicity of PVDF coating was analyzed by the water contact angle. Surface properties were examined by the field emission scanning electron microscopy and scanning probe microscopy. Potentiodynamic polarization was conducted to confirm corrosion protection performance of PVDF coating in terms of hydrophobically-modified fumed silica contents. As a result, the average surface roughness and the water contact angle of the PVDF coating increased with modifier contents. The results of the potentiodynamic polarization test showed an increase of the E_corr values with increase of the hydrophobicity of PVDF coating. Thus, it clearly indicates that the corrosion protection performance of PVDF coating improved with the addition of the hydrophobic-modified fumed silica that prevents the penetration of moisture into the PVDF coating.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.98-100
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• 2012

본 논문에서는 차세대 전술이동통신체계에서의 무선 MSAP Mesh망에서 효율적으로 인증 키를 관리하고 전술이동통신체계의 부하를 줄이는 새로운 혼합형 인증기법을 제안한다. 기존 방식에서 각 MSAP이 체계 접속을 위해서는 중앙집중형 인증기법과 분산형 인증기법을 활용할 수 있는데 각각의 문제점을 안고 있다. 즉, 중앙집중형 인증기법은 MSAP 노드의 빈번한 가입 및 탈퇴로 인한 과다한 지연 문제가 있고 분산형 인증기법은 인증에 필요한 정보를 사전에 공유해야 하는 문제점이 있다. 이러한 문제점을 보완하는 동시에 전술적인 환경에서 악의적인 MSAP 접속 거부와 네트워크 보안성을 극대화하기 위해서는 보다 효과적인 인증기법이 요구된다. 따라서 본 논문에서는 미 인증된 MSAP이 EAP-TLS 기법을 기반으로 전술이동통신 네트워크 진입시 초기인증과 이웃 MSAP간의 상호인증 등 다양한 시나리오를 군의 특수한 환경에 맞추어 구체적으로 제시하고 각 인증 기법의 장 단점을 분석하여 혼합형 인증기법 적용에 타당성을 강조하였다.