• 한국환경보건학회지
• /
• 제10권2호
• /
• pp.89-97
• /
• 1984

The possible effects of garlic (Aliium sativurn L.) extract on growth and aflatoxin production by Aspergillus parasiticus R- 716 were investigated. Various solvent extracts of garlic strongly inhibited growth and sporulation by Aspergillus parasiticus R-716, and effective solvents used for extraction of garlic were chloroform, benzene, and water-chloroform. The growth and aflatoxin production decreased with the increase in extract concentration, and extract equivalent 1.5g of raw garlic weight in 25ml SLS medium completely inhibited, and at a level of 1.25g garlic, total aflatoxin was reduced 64% (472 ${\mu}g$/25ml) of that produced in the control (1, 352 ${\mu}g$/25 ml). During cultivation inhibitory rate of growth was reduced from 89.1% to 40% and aflatoxin $B_2$, $G_1$ production increased with the laps of time. Especially garlic extract appeared to have a stimulatory effect on lipid accumulation on the contrary aflatoxin production.

• 한국안전학회지
• /
• 제29권4호
• /
• pp.61-72
• /
• 2014

The aim of this study is to define the condition of optimal pre-treatment for preferable activated carbon fibers (ACFs), which are based on rayon fibers. This paper shows the ideal path of ACFs preparation process; implies that rayon fibers are pre-treated by various solvents with different times before the heating process. The pre-treated rayon fibers finally turned into desirable rayon fiber-based ACFs through optimal pre-treatment condition by heating processes. The thermal analysis method of pre-treated rayon fibers by thermo-gravimetry analyser (TGA) is an idealized tool, which analyzes the best thermal condition of pre-treatment process. Surface morphologies of resulting rayon fibers based ACFs were examined by scanning electron microscope(SEM). The results of TGA and SEM analyses show that the optimal pre-treatment condition for preparing ACFs was clearly defined, in terms of thermal stability and surface morphology.

• 환경영향평가
• /
• 제9권1호
• /
• pp.75-86
• /
• 2000

The purpose of this work was to document the conditions regarding organic solvent exposure to the workers in paint industry. Air concentrations of organic solvents were measured by passive personal samplers and analyzed by a gas chromatography. Urine samples for hippuric test were also taken from 330 workers who have worked at seven domestic factories for more than two years. Amongst 25 organic elements detected in the indoor environment of working places, toluene was the most common element, and methanol showed the highest mean concentration(18.2ppm). A few elements including methylethyl ketone and toluene partially exceeded the Korean Permissible Exposure Limit. A lack of environmental facilities such as exhaust ventilation, automatic cleaning system, and personal safety devices at present work plaus brings about various occupational diseases.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.65-66
• /
• 2006

Solubility of single wall carbon nanotubes (SWNTs) has been determined in various dispersing media by using the solvent parameters such as Kamlet-Taft parameter and 3-dimensional parameters. Nitric acid-treated SWNTs exhibit significantly improved solubility in hydrogen bondable solvents as well as in solvent mixtures. The forming bucky gel with ionic liquid allows for the new group of dissolving solvent. The dissolution behavior of SWNTs provides a route for SWNT dispersion/exfoliation in preparing electrically conductive films such as transparent electrode.

• 환경위생공학
• /
• 제23권2호
• /
• pp.47-53
• /
• 2008

The ion exchange resins have been synthesized from chloromethyl styrene (dangerous matter) 1, 4-divinylbenzene(DVB) with 1%, 5%, and 15%-crosslinked and macrocyclic ligand of cryptand type by copolymerization method and the adsorption of uranium(VI), cobalt(II) and europium(III) ions have been investigated in various experimental conditions. The correlation between the adsorption characteristics of rare earths and transition metal on the resins and stability constants of complexes with macrocyclic ligand have been examined. The uranium ion was not adsorbed on the resins below pH 2.0, but the power of adsorption of uranium ion increased rapidly above pH 3.0. The adsorption power was in the order of 1%, 5% and 15%-crosslinked resin, but adsorptive characteristics of resins decreased in proportion to the order of dielectric constants of solvents.

• Macromolecular Research
• /
• 제16권4호
• /
• pp.360-366
• /
• 2008

Poly(dialkoxyphenylene 1,3,4-oxadiazole)s were conveniently synthesized to compare their material properties of solvent solubility, thermal stability and molecular alignment with respect to alkyl chain length and meta/para-phenylene structure. All prepared polymers exhibited good solubility in co-solvents containing various volume levels of chloroform to trifluoroacetic acid. Meta-polymers showed slightly better solubility than para-polymers. All polymers produced were thermally stable up to $320^{\circ}C$. Photoluminescence of polymer films was observed with blue light emission at around 450 nm. X-ray diffraction patterns of all polymers indicated that they were composed of stacked molecular sheets with the same layer-to-layer distance of $3.4\;{\AA}$. However, side chain-to-side chain and main chain-to-main distances within the layers increased with increasing alkyl chain lengths. The meta-polymer chains were separated more than the para-polymer chains.

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
• /
• pp.267-268
• /
• 2001

Chlorobenzenes (CBs) are ubiquitous hydrophobic chlorinated organic compounds in the environment. These compounds are used as de-ordants, solvents and pesticides, as well as byproducts of agro- or petro-chemical related manufacturing processes, such as PCBs and pentachlorophenol, or of biodegradation of lindane (Newhook and Meek, 1994). Unlike some organochlorine (OC) compounds, including polychlorinated biphenyls (PCBs) and various pesticides, CBs are not banned from production or use in any country. (omitted)

• 한국염색가공학회지
• /
• 제6권1호
• /
• pp.28-32
• /
• 1994

The synthesis and absorption spectra of squarvlium(SQ) dyes and croconium(CR) dyes were .studied. Absorption spectra of SQ dye in various solvents exhibited a negative solvatochrornism. Thus, it was suggested that the structure of SQ dye may be a highly polar structure. The λ$_{max}$ of CR dyes undergoes a bathochromic shift of about 100nm compared with the corresponding SQ dyes. This shift can be calculated by the Pariser-Parr-Pople molecular orbital method. From the PPP MO calculation results, we found that SQ dye and CR dye have a almost same Highest Occupied Molecular Orbital(HOMO) level(SQ : -8.0eV, CR : -8.09eV). On the other hand, energy levels of Lowest Unoccupied Molecular Orbital(LUMO) of SQ and CR dyes are -4.09eV and -4.13eV respectively. Thus, replacement of five membered ring by four membered ring in SQ dye causes a large bathochromic shift.t.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2010년도 제39회 하계학술대회 초록집
• /
• pp.278-278
• /
• 2010

Electrically tunable photonic band gap (PBG) materials based on crystalline structures have been developed for active components of display. Despite considerable advances, the intrinsic drawbacks of the crystalline PBG materials such as the strong angle dependent hue and difficulty of fabricating defect-free structures in large area have yet to be addressed for their practical applications. Here we report quasi-amorphous colloidal structures exhibiting angle-independent photonic colors in response to the electric stimuli. Moderately polydisperse colloidal Fe3O4@SiO2 nanoparticles dispersed in organic solvents exclusively form quasi-amorphous photonic materials at sufficiently high concentrations (> 30 wt%), and which reversibly reflect incident light in visible region ($\lambda$ peak = 490~655 nm) in response to the relatively low bias voltage (0~4 V). We show the angle-independent tunable photonic colors with the fast response time (50~170 ms) due to the isotropic nature of quasi-amorphous structures. Conventional vacuum injection technique is applicable for fabricating flexible full color photonic display pixels with various pre-defined shapes.

• Bulletin of the Korean Chemical Society
• /
• 제11권1호
• /
• pp.60-64
• /
• 1990

The reactions of alkanesulfonyl chlorides with pyridines in the presence of various solvents have been studied by means of kinetic method. Alkanesulfonyl chlorides bearing ${\alpha}$-hydrogen with the normal attack of pyridine is found to be at the ${\alpha}$-hydrogen with elimination to form the sulfene intermediate evidently. From the mass spectra by the reaction of ethanesulfonyl chloride with 3-picoline in the presence of methanol-$d_1$, it has shown that the reaction has a witness favorable to the slulfene intermediate.