• Nano
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• 제13권12호
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• pp.1850141.1-1850141.11
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• 2018

Sodium ion batteries based on the more sodium source reserve than that of lithium have been designed as promising alternatives to lithium ion batteries. However, several problems including unsatisfied specific capacity and serious cyclic stability must be solved before the reality. One of the effective approaches to solve the abovementioned problems is to search for suitable anode materials. In this work, we designed and prepared $FeSe_2$ nanoflakes via a simple hydrothermal method which can be adjusted in composition by Fe precursor. As a potential anode for sodium storage, the optimized $FeSe_2$ electrode was further evaluated in different electrolytes of $NaClO_4$ in propylene carbonate/fluoroethylene carbonate and $NaCF_3SO_3$ in diethylene glycol dimethyl ether. The capacity was about $470mAh\;g^{-1}$ and $535mAh\;g^{-1}$ at $0.5A\;g^{-1}$, respectively, in the voltage between 0.5 V and 2.9 V in the cycle of stabilization phase. Superior performance both in capacity and in stability was obtained in ether-based electrolyte, which affords the property without plugging the intermediates of transition metal dichalcogenides during charge/discharge processes.

• 한국응용과학기술학회지
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• 제33권1호
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• pp.118-128
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• 2016

대기오염에 관한 관심은 국내 외에서 점진적으로 상승하고 있으며, 자동차와 연료 연구자들은 청정(친환경 대체연료) 연료와 연료품질 향상 등을 이용하여 새로운 엔진 설계, 혁신적인 후 처리 시스템 등의 많은 접근을 통하여 차량 유해 배기가스를 감소시키려고 노력하고 있다. 이러한 연구들은 가솔린 자동차의 배출가스 및 가솔린 차량의 PM 입자 배출 등의 두 가지 이슈로 진행되고 있다. 자동차의 배출가스 및 PM(입자상 물질) 입자는 환경오염과 인체에 악영향을 주는 많은 문제를 일으키고 있다. 추가로, 함산소 첨가제로서 연료에 포함된 MTBE (Methyl Tertiary Butyl Ether)에 대한 환경 문제점을 연구하고 있다. 연구자들은 MTBE가 건강에 미치는 영향에 대한 많은 데이터를 가지고 있다. 이러한 데이터는 높은 MTBE 용량에서 잠재적인 발암 물질 임을 결론짓고 있다. 함산소 연료첨가제 유형 (MTBE, 바이오 ETBE, 바이오 에탄올, 바이오 부탄올)에 기초하여, 본 논문은 가솔린 연료 물성 및 증발가스 배출 특성에 대해 산소함량의 영향을 검토하였다. 또한, 연료물성에 대한 휘발유 차량의 가속 및 출력 성능을 평가하였다.

• 한국수산과학회지
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• 제6권1_2호
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• pp.27-36
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• 1973

The effect of water activity on degradation of pigments in dried lavers, Porphyra tenera Kjellm. was examined when stored at room temperature for fifty days. Chlorophyll pigment was extracted with methanol-petroleum ether mixture solvent(2:1 v/v), partitioned in ether, and analysed spectrophotometrically at 662 nm as chlorophyll a. The degradation products of chlorophyll were isolated on sugar-starch column(85:15 w/w) with n-propanol-petroleum ether solution(1:200 v/v) as a developing solvent. The isolated green colored zones were analysed individually at the wavelengths of 650, 662, and 667 nm as allomerized product, chlorophyll a retained, and pheophytin formed respectively. Carotenoida were also extracted with the methanol mixture solvent, partitioned in ether, and finally redissolved in acetone after the evaporation of ether in a rotary vacuum evaporator. The total carotenoid content was measured as lutein at 450 nm. From the results, it is noted that the rate of chlorophyll degradation reached a minimum at 0.11 to 0.33 water activity while progressively increased at higher moisture levels resulting in rapid conversion of chlorophyll to pheophytin. At lower activity, autocatalysed oxidizing reaction like allomerization seemed prevailing the acid catalysed conversion reaction. The loss of carotenoid pigment was also greatly reduced at the range of 0.22 to 0.34 water activity with much faster oxidative degradation at both higher and extremely lower moisture levels. These two moisture levels indicated above at which the both pigments exhibited maximum stability are considerably higher than the BET monolayer moisture which appeared 7.91 percent on dry basis at Aw=0.10 calculated from the adsorption isothermal data of the sample at $20^{\circ}C$. The rate of pigment loss in heat treated samples at 60 and $100^{\circ}C$ for 2 hours prior to storage somewhat decreased, particularly at higher moisture levels although the final pigment retention was not much stabilized.

• 한국수소및신에너지학회논문집
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• 제27권4호
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• pp.431-440
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• 2016

Electric or hydrogen energy source is expected to solve a various issues including energy security and exhaust pollution. However, it is required a lot of time and a variety of development to apply for commercialization. Therefore, it is needed to translation fuels between the future and the present. DME (Dimethyl Ether) can play a reduce exhaust emission from medium- to heavy-duty engines that are mostly used in commercial sector. It have applied to the DME fuel as a various alternative fuel including power generation in many countries. Especially, it is necessary to secure the energy of energy-poor areas that are widely distributed around the world. And Korea also has the energy-poor areas due to geographical characteristics. These areas has been covered by their own energy through some small diesel generators, diesel boiler etc. If DME fuels are supplied in new demand such as rural sector with energy poor area, DME fuel will be available in the wider sector. In this study, it investigated performance and emission characteristics of agricultural generator and air heater using DME fuel. So the existing equipment of generator and air heater was modified to apply DME fuel. And combustion characteristics and properties of exhaust gas according to the contents of the DME fuel were evaluated. DME fuel showed a potential application in agricultural generator and air heater.

• 약학회지
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• 제31권1호
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• pp.33-39
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• 1987

In order to elucidate the defence mechanism of Cyprinus carpio nudus to Clonorchis sinensis, clonorchicidal substance in the epidermal mucus of this fish was isolated by silica gel column and thin layer chromatography and analyzed for its chemical nature by UV, IR and NMR-spectroscopy. The epidermal mucus of the fish was extracted by ethyl ether and separated into 2 fractions by column chromatography using petroleum ether/chloroform(30/70,v/v) as first solvent and methanol as second solvent. The second fraction with greyish white colour showed clonorchicidal effect. The second was again fractionated into greyish white precipitate and clonorchicidal greenish yellow supernatant fraction, by adding petroleum ether and standing the mixture for 5 days at $5^{\circ}C$. The latter was divided into 7 fractions in column chromatography with acetone/ benzene (10/90, v/v) as carrier. The fraction on equivalent to the spot of Rf. 0.225 value among them disclosed the strongest clonorchicidal effect. By this purification procedure, clonorchicidal substance was purified 154-fold with 0.9% yield from the mucus of the fish, and 10mg of the final fraction killed tne metaceicariae in 22 min. Infra red, nuclear magnetic resonance and ultraviolet spectrometric analysis of the purified substance revealed that the substance is linoleic acid. According to the results of the present studies it seemed that this fish could not be proper intermediate host of Clonorchis sixensis, and that defence mechanism of this fish to the worm seems to be correlated with clonorchicidal substance in epidermal mucus.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권5호
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• pp.9-17
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• 2014

This paper reported the use of real-time polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and the culture-based method in the intrinsic bioremediation study at a petroleum contaminated site. The study showed that phenol hydroxylase gene was detected in groundwater contaminated with benzene, toluene, ethylbenzene, xylene isomers (BTEX) and methyl tert-butyl ether (MTBE). This indicated that intrinsic bioremediation occurred at the site. DGGE analyses revealed that the petroleum-hydrocarbon plume caused the variation in microbial communities. MTBE degraders including Pseudomonas sp. NKNU01, Bacillus sp. NKNU01, Klebsiella sp. NKNU01, Enterobacter sp. NKNU01, and Enterobacter sp. NKNU02 were isolated from the contaminated groundwater using the cultured-based method. Among these five strains, Enterobacter sp. NKNU02 is the most effective stain at degrading MTBE without the addition of pentane. The MTBE biodegradation experiment indicated that the isolated bacteria were affected by propane. Biodegradation of MTBE was decreased but not totally inhibited in the mixtures of BTEX. Enterobacter sp. NKNU02 degraded about 60% of MTBE in the bioreactor study. Tert-butyl alcohol (TBA), acetic acid, 2-propanol, and propenoic acid were detected using gas chromatography/mass spectrometry during MTBE degraded by the rest cells of Enterobacter sp. NKNU02. The effectiveness of bioremediation of MTBE was assessed for potential field-scale application.

• Advances in Traditional Medicine
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• 제5권4호
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• pp.347-351
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• 2005

In the present investigation twelve indigenous medicinal plants have been screened for their antiimplantation activity in albino rats. The plant material was subjected for soxhlation successively and separately from non-polar solvents to polar solvents i.e., petroleum ether benzene and ethanol. Out of these three extracts the petroleum ether extract of seeds of Citrus medica, aerial part of Oxalis corniculata and Tinospora cardifolia have showed maximum antiimplantation activity. Ethanol extract of leaves of Cardiospermum helicacabum, roots of Echinops echinatus, leaves of Melia azedarach, seeds of Momordica charantia and bark of Terminalia bellirica have shown maximum antiimplantation activity amongst the three extracts of each plant material screened. Though all the three extracts of seeds of Annona squamosa and leaves of Zizyphus jujube screened for antiimplantation activity, no extract has showed any loss in implantation. The details of the results obtained are discussed.

• 생약학회지
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• 제16권4호
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• pp.206-209
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• 1985

White needle crystalline compound, mp.\;78{\sim}79$, was isolated from the petroleum ether fraction of the aerial parts of Chenopodium acuminatum. This compound was supposed to be cycloalkane by chemical properties, spectral data and elemental analysis. After extraction with petroleum ether, the methanolic extract of this plant found to contain aspartic acid, threonine, serine, glutamic acid, glycine, cystine, valine, isoleucine, tyrosine, and phenylalanine. Inorganic elements contained in this plant are as following: Mg 4.84%, Ca 9.602%, Zn 1.11%, K 29.104%, Mn 5.124%, Fe 27.039%, Co 0.31%, Pb 0.995%, Na 0.039% and Cu, 0.0076%.

• 한국식품영양학회지
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• 제11권4호
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• pp.426-430
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• 1998

This study was conducted to investigate electron donating ability, antioxdative activity and nitrite-scavenging effect of solvent extracts from Gyrophora esculenta. The phenolic compounds of diethylether, butanol, petroleum ether and hexane extracts were 194.20$\mu\textrm{g}$/ml, 98.80$\mu\textrm{g}$/ml, 1.60$\mu\textrm{g}$/ml and 0.20$\mu\textrm{g}$/ml, respectively. Electron donating abilities of diethyleter and butanol extracts from Gyrophora esculaenta were 80.79% and 72.81%, respectively. Absorption of DPPH by diethyleter and butanol extracts sharply increaed at initial stage. Antioxidative activities of fiethylether and butanol extracts by peroxide values are rather high as compared to those of control, but low s compared to those of BHA. Nitrite-scavenging abilities of diethylether, butanol and petroleum ether from Gyrophora esculenta were 96.07%, 77.39% and 15.07%, respectively.

• 생약학회지
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• 제18권3호
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• pp.184-187
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• 1987

Fatty acids and sterols were isolated from petroleum ether extract of seeds of Acanthopanax sessiliflorum Seeman. Fatty acids were obtained from the saponified fraction and sterols from nonsaponified fraction of petroleum ether extract. Fatty acids were identified by gas liquid chromatography, and its composition was myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. The composition of sterols were determined by preparative TLC and gas liquid chromatography. It was confirmed to be a mixture of stigmasterol and ${\beta}-sitosterol$. These fatty acids and sterols were not previously reported from seeds of Acanthopanax sessiliflorum Seemann.