• Journal of the Korean Chemical Society
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• v.28 no.5
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• pp.323-327
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• 1984

Nicotine was reacted with an equimolar amount of ozone in methylene chloride and distilled water. The reaction mixture was separated by column chromatography or thin layer chromatography and then purified by vacuum distillation. The six compounds obtained from this reaction were characterized by NMR, IR and Mass spectrometry. These were identified as unchanged nicotine, nornicotine, anabasine, ${\beta}$-nicotyrine, cotinine and nicotine-N-oxide. From these results, reaction mechanism for the ozonolysis ofon nicotine was proposed; the pyrrolidine ring is attacked by ozone at the 1'-position followed by further transformation.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.671-679
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• 2010

The geometrical parameters and binding energies of the benzene ion-water complex [$C_6H_6^+-(H_2O)_n$(n=1-5)] have been investigated using ab initio (MP2) and density functional theory (DFT) with large basis sets. The harmonic vibrational frequencies and IR intensities are also determined to confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the binding energies. The predicted binding energy of 8.6 kcal/mol for $C_6H_6^+-(H_2O)$ at the MP2/aug-cc-pVTZ level of theory is in excellent agreement with recent experimental result of $8.5{\pm}1$ kcal/mol.

• Journal of the Korean Chemical Society
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• v.41 no.2
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• pp.88-97
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• 1997

The silyltriflates$(Ph_{3-n}SiH(OTf)_n)$have been produced by the reaction of triphenylsilane and triflic acid$(CF_3SO_3H)$at low temperature. These highly reactive compounds are a valuable reagent for the synthesis of numerous new functional substituted silane derivatives. The reaction of silyltriflates with alkenyl- and alkynylmagnesium bromide as well as organolithium compounds gave new silanes$Ph_2SiHR(R=\;C(CPh,\;CH=CH_2,\;CH_2CH=CH_2,\; (CH_2)_2CH=CH_2,\;(CH_2)_3CH=CH_2)$in high yields. The hydrosilation of prepared alkenyl- and alkynylsilanesPh_2SiHR$in the presence of a platinum catalyst(Pt/C) at high temperature$(200{\circ}C)$gave carbosilane polymers$((Ph_2SiCH=CPh)_n$and$(Ph_2Si(CH_2)m)n;\;m=2∼4, n{\ge}10)$along with five- and six-membered silaalkane ring compounds derived from intramolecular hydrosilation reactions. All of the prepared compounds are confirmed by NMR, UV, IR and mass spectroscopy as well as elemental analysis.

• Membrane Journal
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• v.11 no.3
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• pp.116-123
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• 2001

Polyimide-silica hybrid membranes were prepared and the effect of silica content on the structural properties and the gas transport properties was studied. The hybrid membranes were obtained by the sol-gel process starting from 1,2,4,5-benzenetetracarboxylic dianhydride(PMDA), 4,4`-diamino- diphenyl oxide(ODA) and tetraethoxysilane(TEOS) in N,N` dimethylacetatmide (DMAc) solvent. The structural characterizations of the membrane were performed by FT-IR, EDX, TGA and SEM. The gas permeation experiments with ${N_2}, {O_2}, {H_2}, {CO_2}and ${CH_4}$ were carried out at the temperature of $25^{\circ}C$ and in the range of pressure from 3atm to 7atm. the hybrid membranes showed higher thermal stability than PI membranes. The silica patricles were uniformly embedded in the polyimide matrix and the size of silica particles increased with increasing silica content. The permeability coefficients of ${N_2}, {O_2}, {H_2}, {CO_2}and ${CH_4}$ increased with increasing silica content but the diffusion coefficients might appear to be a result of a solubility enhancement. In spite of the permeability enhancement, an increase in the selectivities of ${H_2}/{N_2}, ${H_2}/{O_2} and ${H_2}/{CO_2} was observed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.89-93
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• 1983

Rice plant was tested in the phytotron to know the varietal difference of ethylene production in different nitrogen levels. The high nitrogen concentrated varieties among tested varieties produced a large amount of ethylene. But high nitrogen concentrated leaf in the one variety produced less amount of ethylene. The varieties which produced a large amount of ethylene was remarkably increased ethylene in no nitrogen plot$(N_0)$ compare to standard level$(N_1)$. In contrast low ethylene producing varieties was remarkably decreased in double nitrogen level$(N_2)$.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.183-187
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• 2010

Activated carbons (ACs) have been prepared from pitch by the combination of a chemical oxidation with different $H_2O_2$ concentrations i.e., 5, 15, and 25 wt% and a chemical activation with KOH at a constant KOH/pitch ratio of 3/1. The influence of $H_2O_2$ solution on the microporous properties of the pitch and the final activated carbons were invested using XRD, FT-IR, XPS, $N_2$-adsorption, and SEM. XRD indicated that the value of interplanar distance $d_{002}$ increased by chemical oxidation. FT-IR and XPS results showed that the chemical oxidation promoted the formation of surface oxygen functionalities. Also, the specific surface area of the resulting ACs was increased with increasing the concentration of $H_2O_2$ chemical oxidation and showed a maximum value of $2111m^2/g$ at 25 wt% $H_2O_2$ concentration.

• Advances in pediatric surgery
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• v.15 no.1
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• pp.27-37
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• 2009

Neuroblastoma is the most common extracranial solid tumor in children. We retrospectively analyzed the results of neuroblastoma treatment of 191 patients (116 males and 75 females) treated between January 1986 and December 2005 at the Department of Pediatric Surgery and the Department of Pediatrics, Seoul National University Children's Hospital. The mean age at diagnosis was 3.1 years (0.1 yrs - 13.5 yrs). Forty-seven patients were under 1 year of age. The mean follow-up period was 57.3 months (24 days - 19.1 yrs). Patients were classified into two groups according to the completeness of resection of the primary tumor; (1) gross total resection (GTR) and (2) incomplete resection (IR). The number of patients in stages I, II, III, IV, IV-S were 17 (8.9 %), 12 (6.3 %), 43 (22.5 %), 114 (59.7 %), 4 (2.1 %), respectively. GTR was achieved in 120 patients and IR in 71 (22 stage III, 47 stage IV, 1 stage IV-S, 1 brain). Overall survival (OS) was 65.2 % and event-free survival (EFS) was 48.6 %. EFS were 100 %, 75 %, 66.8 %, 31.3 %, 75 % at stage I, II, III, IV, IV-S, respectively. There was no significant difference in EFS according to the completeness of resection. EFS was improved in GTR group (p=ns) of stage III, but by contrast, stage IV patients showed worse EFS in GTR group. EFS was improved significantly after the introduction of autologous stem cell transplantation (ASCT) (58.1% vs. 40.6%, p=.029). The EFS improved significantly after the introduction of ASCT in IR group (p=.009) rather than GTR group (p=ns). The EFS of the patients under 1 year of age (N=47) was better than the patients over 1 year of age (N=144) significantly (75.5 % vs. 39.4 %, p=.0034). The prognosis of neuroblastoma was related to the INSS stage and age at diagnosis. The survival of IR group significantly improved after ASCT.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.49-62
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• 2018

PURPOSE: This study investigated the influence of a specific hip joint exercise program on the characteristics of chronic low back pain (LBP), hip joint range of motion (ROM), and performance level in amateur golfers with LBP. METHODS: The study included 28 adult male amateur golfers with LBP and reduced internal rotation (IR) of the lead side hip joint. Subjects were randomly assigned to an experimental (EG) (n=14) or control group (CG) (n=14). The Numerical Rating Scale score for pain, ROM of the hip joint and trunk rotation, performance parameters for golfing were evaluated. A specific exercise program designed to improve IR of the lead side hip joint was performed by the EG, but not the CG. Post-intervention evaluation was performed and the collected data were analyzed. RESULTS: After the intervention, the severity of LBP was significantly reduced (p<.05) and the IR ROM of the lead side hip joint was significantly increased (p<.01) in the EG. Moreover, the trunk rotation range was significantly increased in the EG (p<.01). The drive distance was significantly difference between the EG and CG (p<.05). CONCLUSION: A specific hip joint exercise program can help to reduce pain level and improve performance level in amateur golfers with LBP and increased IR ROM of the lead side hip joint. A significant increase in ROM of the lead side hip joint reduce LBP and was related to driving distance in the EG.

• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.269-274
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• 2018

Surface renewable nano-$RuO_2$/poly(methyl methacrylate) polymeric composite pH electrodes were prepared. The composite electrode with 53 wt% of nano-$RuO_2$ showed similar good response characteristics to nano-$IrO_2$ composite electrode reported earlier. It showed response slope of -58.7 mV/pH, response time of <1 s, surface renewability of $-57.0{\pm}0.3mV/pH$ (n=5) and long time stability for a month as well as low interferences but high interferences by electrochemically active species like $I^-$ and $Fe(CN){_6}^{3-}$. However, the response slope and time became worse at higher pH than 9 compared to those of nano-$IrO_2$ composite electrodes possibly due to the difference of physical properties resulting from higher content of nano-$RuO_2$ in polymeric composite matrix.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.36-44
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• 2016

In this paper, an Impulse Radio-Ultra Wide band RF Transceiver for WBAN applications is implemented in $0.18{\mu}m$ CMOS technology. The designed RF transceiver support 3-5GHz UWB low band and employs OOK(On-Off Keying) modulation. The receiver employs non-coherent energy detection architecture to reduce complexity and power consumption. For the rejection of the undesired interferers and improvement of the receiver sensitivity, RF active notch filter is integrated. The VCO based transmitter employs the switch mechanism. As adapt the switch mechanism, power consumption and VCO leakage can be reduced. Also, the spectrum mask is always same at each center frequency. The measured sensitivity of the receiver is -84.1 dBm at 3.5 GHz with 1.579 Mbps. The power consumption of the transmitter and receiver are 0.3nJ/bit and 41 mW respectively.