• Fire Science and Engineering
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• v.16 no.3
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• pp.32-38
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• 2002

The synthesis of $CF_3$I and $C_2F_5I from $CF_3Br$ was studied for the reuse of $CF_3Br$ which is abolished to save the ozone layer of the earth. Reaction experiments were carried out in experimental scale synthesis equipment with catalysts, such as CuI, Kl, $K_2$$CO_3$, KF metal salt/active carbon and alumina support at $400~600^{\circ}C$. Main products of reaction were $CF_3i$ and $C_2F_5I$ with small amounts of $C_2F_5I$, $CF_4$, $CF_2Br_2$ by-products. 7.5wt% KI and $K_2CO_3$over activated carbon catalysts show the highest yield of $CF_3$I and 7.5wt% CuI over alumina catalysts show the highest yield of $C_2F_5i$. And optimal reaction temperature was about $500^{\circ}C$.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1582-1583
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• 2011

Recently, it has been found that trifluoroiodomethane ( $CF_3I$) gas can replace $SF_6$ gas as a prospective substitute gas. For quantitative understanding of gas discharge phenomena, we should know electron collision cross sections and electron transport coefficients. Using electron collision cross sections of $CF_3I$ and Xe, we calculated elecron drift velocity, longitudinal coefficient, effective ionization coefficient in $CF_3I$-Xe mixtures using a two-term approximation of the Boltzmann equation. We also compared the electron transport coefficients in pure gas and those of 10%, 20%, 50%, and 70% $CF_3I$-Xe mixture gases. The present data may be showed appropriate ratios of $CF_3I$-Xe mixture gas for replacing the $SF_6$ gas.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2385-2391
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• 2018

This paper is devoted to detecting decomposition characteristics of Iodotrifluoromethane ($CF_3I$) under alternating current (AC) discharges or load current interruptions. The decomposition products are measured utilizing chromatography-mass spectroscopy. It is found that less than 1% $CF_3I$ gas decomposed after several interruptions at load current of 200 A or hundred times of AC discharges. However, under interruptions at a current of 400 A, more than 95% $CF_3I$ gas decomposed into carbon tetrafluoride ($CF_4$) and hexafluoroethane ($C_2F_6$). The equilibrium compositions based on Gibbs free energy minimization of $CF_3I$ was calculated to explain the decomposition mechanism.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.867-873
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• 2015

The potential of nitrogen mineralization was studied by applying organic fertilizer to soil and incubating at $25^{\circ}C$ for 28 weeks. The organic fertilizers used in this experiment were oil-cake (CF-I, CF-II) and amino acid fertilizer (AAF-I, AAF-II). Accumulated mineralized nitrogen (N) fits the frist-order kinetics during incubation. The N mineralization potential ($N_0$) for organic fertilizers treated soil was highest at AAF-II treatment with a value of 27.71 N mg/100g, then followed by CF-II, AAF-I, CF-I. The pure N mineralization potential ($N_0$ treatment - $N_0$ control) for CF-I, CF-II, AAF-I, AAF-II were 2.55, 5.83, 3.66, 8.57 N mg/100g, respectively. The amount of N mineralized from organic fertilizers applied soil ranged from 46% to 61% of the total N content in organic fertilizer. The half-life ($t_{1/2}$) of organic nitrogen in soil treated with oil-cake and amino acid fertilizer was 17-21 days. Therefore, half of nitrogen contained in oil-cake and amino acid fertilizer was mineralized after 3 weeks application.

• Bulletin of the Korean Chemical Society
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• v.13 no.5
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• pp.556-559
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• 1992

Hydrocarbon solution of $(PPh_3)_2(CO)MOSO_2CF_3$ (M= Rh, Ir) reacts rapidly with 1,4-dicyanobenzene or 1,4-dicyano-2-butene to yield dinuclear metal complexes $[(PPh_3)_2(CO)M({\mu}-dicyanobenzene)M(CO)(PPh_3)_2](SO_3CF_3)_2$ (I: M = Rh; II: M = Ir) or $[(PPh_3)_2(CO)M({\mu}-dicyano-2-benzene)M(CO)(PPh_3)_2](SO_3CF_3)_2$ (III: M = Rh; IV: M = Ir), respectively. Compounds I, II, III, and IV were characterized by $^1H$-NMR, $^{31}P$-NMR, and infrared spectrum. Dichloromethane solution of II and IV reacts with $H_2\;and\;I_2$ to yield oxidative addition complexes $[(PPh_3)_2(CO)IrX_2({\mu}-E)X_2Ir(CO)(PPh_3)_2](SO_3CF_3)_2$ (V; E = 1,4-dicyanobenzene, $X_2$ = $H_2$; VI : E = 1,4-dicyano-2-butene, $X_2$ = $H_2$; VII; E = 1,4-dicyanobenzene, $X_2$ = $I_2$). All metal complexes are bridged by the cyanide groups. Compounds Ⅴ, Ⅵ, and Ⅶ are characterized by conventional methods.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.262-268
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• 2003

This paper describes the effect of loading rate, specimen geometries and material properties for Mode I interlaminar fracture toughness of hybrid composite by using double cantilever beam (DCB) specimen. In the range of loading rate 0.2-20mm/min, there is found to be no significant effect of loading rate with the value of critical energy release rate (G_IC). The value of $G_IC$ for variation of initial crack length are nearly similar values when material properties are CF/CF and GF/GF, however, the value of $G_IC/$ are highest with the increasing initial crack length at CF/GF. The SEM photographs show good fiber distribution and interfacial bonding of hybrid composites when the moulding is the CF/GF

• Journal of Pharmacopuncture
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• v.4 no.1
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• pp.103-104
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• 2001

This study was done to observe the effect on the local thermal changes of herbal acupuncture on D.I.T.I.. The objects of this study are as follows; If there are remarkable local thermal changes between pre and post herbal acupuncture therapy on D.I.T.I.or not. If there are those, We examine how long that changes are maintained, what the adequate interval is on herbal acupuncture therapy, and what the reaction in a .local or whole body are on that therapy Materials and Methods : To study the local thermal changes in herbal acupuncture therapy, D.I.T.I. was used. Determination of this analysis periods are pre and post-therapy(1 hour, 24hours, 48hours and 7days later). The study group was divided into three groups(comprised 23 students in oriental medical college, Woosuk University). One was NS(Normal Saline) group, another was CF(CARTHAMI SEMEN) group and the other was BU(FEL URSI + BENZOAR BOVIS) group. The Herbal Acupunture solution was injected 0.2ml divide into 0.05ml at tile P'ungmun(B12), P'yesu(B13), Pubun(B41), Paek'o(B42) 4 points. Then, in order to analyze the clinical form, we have observed response of 23 students whenever we checked the thermal changes of their after perfoming Results : The results were obtained as follows ; 1. There is no significant dermatothermal changes at NS group and CF group, but BU group have remarkable changes in 24, 48, 72 hours. 2. From post-therapy 1 hour to 48 hours, there is a significant change (P<0.01) at NS-BU group and CF-BU group, But there is none 7 days later. 3. In the analysis of whole or local body reaction, local pain appears at NS group(22%), CF group(11%), BU group(91%), discomfort reaction appears at CF group(14%), BU group(30%). BU groilp has feel vertigo(13%), drowsy (70%) and pain in action(52%). 4. In the analysis of the duration of physic진 reaction, BU group is most lately maintained. Conclusions : These results suggest that in the physical reaction of herbal acupuncture solutions, BU solution is more sensitive than CF solution or NS.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.6
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• pp.102-108
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• 2001

To prevent green house effect and destruction of an ozone layer, an ozone destruction potential(OBP) must be zero and a refrigerant for low global warming potential(GWP) is needed. HFC-l34a, in which hydrogen is mixed instead of chlorine is a refrigerant used for automobile conditioners and its destruction potential is ecologically zero. However, it is not consid- ered as a perfect substitutive refrigerant as its GWP is high. It is studied refrigerant mixtures in which HFC-l52a and $CF_3 I$ in HFC-l52a with low GWP and zero ODP are mixed by experimentally and concluded as follows: 1) With the variation of speed of compressor outside temperature and flow rate, 7he heat of evaporator and compressor and coefficient of perfor- mance was varied, and influenced the air conditioner. 2) The pressure of evaporator was decreased with increasing the speed of compressor and the pressure of evaporator with the refrigerant HFC-l52a was higher 24% than that of azotrope refrigerant mixed with $CF_3 I$

• Journal of the Korean Chemical Society
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• v.44 no.2
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• pp.127-137
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• 2000

Eleven new compounds that are composed of bis(p-substituted phenyl) terephthalate unitand the decyloxy pendant as lateral were synthesized and their thermal and liquid crystalline properties were studied by the differential scanning calorimetry (DSC) and on a hot-stage of a polarizing microscope. The ter-minal substituent groups of the compound were varied; X= -H(II-H), -F(lI-F), -CII(II-CI), -Br(ll-Br), -I(II-I), -$NO_2(lI-NO_2$), $-CF_3(II-CF_3$), -$OC_2H_5(II-OC_2H_5$), -$OC_4H_9(II-OC_4H_9$), -$C_6H_5(Il-C_6H_5$). The compounds of $II-OC_2H_5,\;II-OC_4H_9$ and $II-C_6H_5$ were monotropically nematic. In contrast, the compounds of Il-H, II-F, II-Cl, II-Br, II-I, $lI-NO_2$, $II-CF_3$, and II-CN did not show liquid crystalline properties.

• Journal of the Korean Solar Energy Society
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• v.23 no.2
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• pp.71-79
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• 2003

The goal of this paper is to measure and compare the performance of solar heat pump for refrigerants. To accomplish the goal, solar heat pump with aluminum roll bond type evaporator and indoor heat exchanged(condenser) was built. The test results showed that the COP and heating capacity of HFC-32/125/134a(23/25/52 wt%, $CH_2F_2/CF_3CHF_2/CF_3CH_2F$) were higher than those of HCFC-22$(CHClF_2)$. A study proved that best conditions to use heating system that is about $40m^2$ and $80m^2$. The COP range of the whole system was from 4 to 6 according to the solar collector's area variation. Hydrochlo-rofluorocarbon HCFC-22$(CHClF_2)$ is included in the compound to be controlled. HFC-32/125/134a(23/25/52 wt%, $CH_2F_2/CF_3CHF_2/CF_3CH_2F$) is the most suitable replacement HCFC-22$(CHClF_2)$ in solar heat pump application. The solar heat pump system was designed to show the best efficiency that the room temperature make $18\sim20^{\circ}C$ and $23\sim25^{\circ}C$ in Seoul during the fall season.