• Applied Chemistry for Engineering
• /
• v.33 no.1
• /
• pp.103-108
• /
• 2022

This research work reports the development of a Ruthenium/2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO)/nitrate catalyst system for the highly selective transformation of isosorbide (1,4:3,6-dianhydro-D-glucitol) to isosorbide-diketone (2,6-dioxabicyclo (3,3,0)octan-4,8-one). Isosorbide is a critical platform molecule for future manufacturing processes. TEMPO has been utilized to convert alcohols to carbonyl compounds for a long time. The optimal chemical reaction condition was found to be when using isosorbide (0.5 mmol) with supported Ru (10 mol%), TEMPO (5 mol%), and sodium nitrate (0.03 mmol) in the presence of acetic acid (3 ml) as a solvent at 50 ℃ and 1 atm oxygen pressure. This catalyst system demonstrated good selectivity (> 97%) and yield (87%) with respect to the desired product, in addition to a putative catalytic double oxidation mechanism.

• Applied Chemistry for Engineering
• /
• v.34 no.3
• /
• pp.291-298
• /
• 2023

This research evaluates the sustainability of gasifying livestock manure to produce fuel gas from an economic and carbon emission perspective. The entire process, including gasification, fuel gas purification, and pipeline installation to transport the produced fuel gas to the demanding industrial complex, is analyzed for realistic feasibility. The study is conducted using an ASPEN PLUS simulation with experimental data. The results of the economic and CO₂ life cycle assessments confirm that the fuel gas produced from livestock manure is competitive with natural gas despite having a lower calorific value. When used as a fuel with a high hydrogen content, the fuel gas emits less CO₂ per calorific value, making it more environmentally friendly. A scenario analysis is also performed to determine the expected economics, with price competitiveness being influenced by several factors. Although a significant decrease in natural gas prices could reduce the price competitiveness of the proposed process, it can still be supported by government policies. The cash flow analysis also confirms the economic viability of the process.

• Journal of Appropriate Technology
• /
• v.5 no.1
• /
• pp.46-53
• /
• 2019

It should be supported by the ease and economic production in terms of appropriate technology to be widely used in the real applying fields. In particular, the diagnosis of diseases is one of the most difficult areas to apply to the developing countries compared to other fields because of the high costs of professional manpower, equipment, and medial reagents. In recent years, paper, which is one of the most common materials around, has been used to fabricate the disease diagnostic chips, particularly without any special facilities or the equipment. These new technologies lead the possibility of using point-of-care testing devices that can be manufactured quickly in the field by lowering the production cost. These paperbased technologies will contribute to solve many of the deadliest medical problems in developing countries and ultimately improve the quality of human life.

• Proceedings of the KIEE Conference
• /
• 2001.11a
• /
• pp.124-127
• /
• 2001

In this study, the electrical properties of polymer thin film layered by spin-coating method was investigated, and this polymer is one of the polymer applied to insulation layer for display, this polymer has relatively high dielectric constant, hygroscopic property and easy to make thin film by spin-coating. That is, in this study use the polymer that is cyano acrylate terpolymer, and the MIM(Metal/Insulator/Metal) structures were fabricated to measure the electrical properties such as Voltage-Current characteristics and dielectric characteristics. Also the conductivity and dielectric constant has been calculated. As a result, the conductivity in room temperature was $0.85{\times}10^{-14}{\sim}1.35{\times}10^{-14}$[S/cm]. The fact that this polymer be acted as insulator can be supported by this result. The dielectric constant was calculated as $10.39{\sim}12.05$ higher than Dopont Inc., this make it possible to accumulate more charges in insulation layer under same condition.

• Carbon letters
• /
• v.7 no.2
• /
• pp.105-113
• /
• 2006

The electro-chemical removal (ECR) of water pollutants by metal-ACF electrodes from wastewater was investigated over wide range of ECR time. The ECR capacities of metallic ACF electrodes were related to physical properties such as adsorption isotherm, surface area and pore size and to reaction time. Surface morphologies and elemental analysis for the metal supported ACFs after electro-catalytic reaction were investigated by scanning electron microscopy (SEM) and energy disperse X-ray (EDX) to explain the changes in adsorption properties. The IR spectra of metallic ACFs for the investigation of functional groups show that the electro-catalytic treatment is consequently associated with the removal of pollutants with the increasing surface reactivity of the activated carbon fibers. The metal-ACFs were electro-catalytically reacted to waste water to investigate the removal efficiency for the COD, T-N, $NH_4$-N, $NO_3$-N and $NO_2$-N. From these removal results of the piggery waste using metallic ACFs substrate, satisfactory removal performance was achieved. The removal efficiency of the metallic ACFs substrate was mainly determined by the properties of the material for adsorption and trapping of organics, and catalytic effects.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.6
• /
• pp.1032-1041
• /
• 2010

The comparative influence of two nanoparticles [viz., superparamagnetic iron oxide nanoparticles (SPION) and nanobarium titanate (NBT)] upon the in vitro and in situ low-density polyethylene (LDPE) biodegradation efficiency of a potential polymer-degrading microbial consortium was studied. Supplementation of 0.01% concentration (w/v) of the nanoparticles in minimal broth significantly increased the bacterial growth, along with early onset of the exponential phase. Under in vitro conditions, ${\lambda}$-max shifts were quicker with nanoparticles and Fourier transform infrared spectroscopy (FTIR) illustrated significant changes in CH/$CH_2$ vibrations, along with introduction of hydroxyl residues in the polymer backbone. Moreover, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) reported multiple-step decomposition of LDPE degraded in the presence of nanoparticles. These findings were supported by scanning electron micrographs (SEM), which revealed greater dissolution of the film surface in the presence of nanoparticles. Furthermore, progressive degradation of the film was greatly enhanced when it was incubated under soil conditions for 3 months with the nanoparticles. The study highlights the significance of bacteria-nanoparticle interactions, which can dramatically influence key metabolic processes like biodegradation. The authors also propose the exploration of nanoparticles to influence various other microbial processes for commercial viabilities.

• Journal of the Korean Applied Science and Technology
• /
• v.22 no.2
• /
• pp.168-174
• /
• 2005

Aluminum tri-butoxide was mixed with the water/ethanol solution and then chloroplatinic acid was added to the solution. The solution was dried at $100^{\circ}C$ for 15hrs to remove the solvent and water then it was calcined at $500^{\circ}C$. The catalyst was activated with a gas mixture. During the activation, the temperature was increased from $150^{\circ}C$ to $500^{\circ}C$. The necessary amount of urea was dissolved in 50mL water and injected. Aqueous urea solution was then mixed with the feed gas stream. At low temperatures, nitrogen containing compounds of urea decomposition are used as reductants in the reducton of $NO_X$. However at high temperatures the nitrogen containing compounds are oxidized to NO and $NO_2$ by oxygen instead of being used in the reduction. The activity of the catalyst was dependent on urea concentration in the feed stream when there was not adequate water vapor in the feed. The maximum conversion was shifted from $250^{\circ}C$ to $150^{\circ}C$ when water concentration was increased from 2 to 17%. It seems that the maximum temperature shifts to lower temperatures because the hydrolysis rate of HNCO increases with water, resulting in higher amounts of $NH_3$.

• Journal of the Korean Ceramic Society
• /
• v.27 no.7
• /
• pp.883-890
• /
• 1990

Although various theories have been presented on the mechanism of setting retardation of 3CaO·Al2O3, this phenomenon has not yet been defined. The present investigation was initiated in order to solve the mechanism from the view point of coordination chemistry. The solubility of Ca(OH)2 in aquous solution of soldium gluconate was abnormally high, and was proportional to the concentration of sodium gluconate. These phenomena were attributed to the soluble complex formation, that is, (1 : 1)Ca complex formation between calcium ion and gluconate ion. The author's proposal was further confirmed by the results of electrical conductivity measurement. The formation of calcium complex was also supported by IR spectra and DTA. When sodium gluconate was dissolved in 3CaO·Al2O3 suspension, calcium complex and aluminum complex were formed. As an experimental evidence, the asymmetric stretching vibration of carboxyl group in sodium gluconate was observed to be shifted to lower frequency from 1625cm-1 to 1585cm-1 characteristically. The characteristic exothermic peaks of the complexs at 430℃ and 700℃ observed in DTA curve also suggest the formation of the complexs between sodium gluconate and 3CaO·Al2O3.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.8
• /
• pp.2375-2380
• /
• 2014

In the present investigation, a series of some novel 1,3-diaryl/heteroarylprop-2-en-1-one derivatives (3a-j) have been synthesized and evaluated for their in vitro cytotoxicity against three cancer cell lines, two hepatocarcinoma cell lines HUH-7, Hep-3b and one leukemia cancer cell line MOLT-4. Based on these results, structure-activity relationship (SAR) was studied on modification of $R^1$ and $R^2$ to identify the compound with maximum potency. Amongst the compounds, 3b and 3d strongly inhibited the growth of Hep-3b and MOLT-4 cells with $IC_{50}$ value of 3.39 and $3.63{\mu}M$ respectively. The results obtained from the inhibitory study had further been supported by the reactive oxygen species (ROS) measurement using flow cytometry in MOLT-4 cells. These observations collectively reveal that compounds comprising 1,3-diarylprop-2-en-1-one framework with pyrazole ring at position-3 and heteroaryl/aryl substituents at position-1 can be used as promising anticancer agents.

• Transactions of the Korean hydrogen and new energy society
• /
• v.22 no.4
• /
• pp.415-423
• /
• 2011

HI decomposition step certainly demand catalytic reaction for efficient production of hydrogen in SI process. Platinum catalyst can apply to HI decomposition reaction as well as hydrogenation or dehydrogenation. Generally, noble metal is used as catalyst which is loaded form for getting high dispersion and wide active area. In this study, Pt was loaded onto zirconia, ceria, alumina, and silica by impregnation method. HI decomposition reaction was carried out under the condition of $450^{\circ}C$, 1atm, and $167.76h^{-1}$ (WHSV) in a fixed bed reactor for measuring catalytic activity. And property of a catalyst was observed by BET, TEM, XRD and chemisoption analysis. On the basis of experimental results, we discussed about conversion of HI according to physical properties of the loaded Pt catalyst onto each support.