• Journal of the Korean Ceramic Society
• /
• v.31 no.4
• /
• pp.436-447
• /
• 1994

ZnO transparent conducting thin film, which is a strong candidate for a transparent electrical contact in optoelectronic devices, was prepared by the vapour spraying method on the slide glass in nitrogen ambient at the atmospheric pressure. The structural, optical and electrical properties of films show a strong dependence on substrate temperature, and the optimum range of deposition temperature existed to obtain TCO(Transparent Conducting Oxide) films. At the higher temperatures, milky films were obtained. In such optimum range, the bandgap in ZnO films was determined from the spectral dependence of absorption coefficient and electrical characteristics were characterized with by the Hall mobility and carrier concentration.

• 연구논문집
• /
• s.31
• /
• pp.23-43
• /
• 2001

An experimental investigation on the reduction of nitrogen oxide emission from swirling, turbulent diffusion flames was conducted using multi air staged combustor, The combustor utilizes swirler to dampen fuel/air mixing, allowing an extended residence time for fuel pyrolysis and fuel-N conversion chemistry in an locally fuel-rich environment prior to burnout. This process also allow to reduce thermal NOx formation to lessen the temperature of reaction zone. The aerodynamic process therefore emulates the conventional staged combustion process, but without the need for the physically separate fuel-rich and -lean stages. Parametric studies on the ratios of each staged air and droplet size were carried out the feasibility of fuel/air mixing for low NOx combustion with diesel and pyridine mixed diesel fuel oil.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.252-254
• /
• 2003

A magnetic field sensor is fabricated with superconducting ceramics system. The sensor at liquid nitrogen temperature shows the increase in electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor is changed from zero to a value more than $100{\mu}V$ by the applied magnetic field. The change in electrical resistance depends on magnetic field. The sensitivity of this sensor is 2.9 ohm/T. The increase in electrical resistance by the magnetic field is ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.161-162
• /
• 2006

Scaling rules for TFT application devices have led to the necessity of ultra thin dielectric films and high-k dielectric layers. In this paper, The advantages of high concentration of nitrogen in silicon oxide layer deposited by using $N_2O$ in Inductively Coupled Plasma Chemical Vapor Deposition (ICP-CVD) reported about Ellipsometric measurement, Capacitance-Voltage characterization and processing conditions.

• Bulletin of the Korean Chemical Society
• /
• v.11 no.1
• /
• pp.22-25
• /
• 1990

The condensation of 1-amino-1,2-dihydro-3,6-pyridazinedione (1) and 2-amino-2,3-dihydro-1,4-phthalazinedione (2) with mesityl oxide or 3-penten-2-one in acetic acid-ethanol (1:1) gave 3,4,6,9-tetrahydro-6,9-dioxopyridazino[1,2-a][1,2, 3]triazines (9,11) and 3,4,6,11-tetrahydro-6,11-dioxo[1,2,3]triazino[1,2- b]phthalazines (10,12), respectively. The condensation of 1 and 2 with crotonaldehyde, cinnamaldehyde or acrylaldehyde under the same reaction condition gave only N-alkylidene derivatlives (3-8). When the N-alkylidene derivatives isolated from the reaction of 1 and 2 with crotonaldehyde and cinnamaldehyde (3-6) were refluxed in acetic acid, the corresponding heterocyclic compounds (13-16) were obtained.

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.196.2-196.2
• /
• 2003

The Barks of Ulmus davidiana (Ulmaceae) have been used for the treatment of insecticide, anti-boil and anti-fungi in Korean traditional medicine. Four phenolic compounds were isolated from 80% Acetone extracts. The structures of these compounds were elucidated as (+)-catechin, (+)-catechin 7-O-${\beta}$-D-glucopyranoside, (+)-catechin 7-O-${\beta}$-D-xylopyranoside and procyanidin B-1. These phenolic compounds showed significant nitrogen monoxide(NO) production inhibitory activity in IFN-${\gamma}$, LPS stimulated RAW 264.7 cell and also showed significant antioxidative activity on DPPH radical. (omitted)

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.193-194
• /
• 2021

Ti-salt agglomerated titanium dioxide photocatalyst from sludge, which has various and excellent functions such as nitrogen oxide removal performance, antifouling performance, and bacteria removal performance, is intended to be applied to UHPC. The UHPC used in this study is supposed to have a high compressive strength of 100~200MPa and a high flowability of 600mm or more with a slump flow. Titanium dioxide is fixed to the UHPC surface by sieving through a test sieve and compaction and painting using a vibration compactor, and this is tested according to ISO 22197-1. The NO removal amount is evaluated by classification the result range.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.3
• /
• pp.330-336
• /
• 2005

The ozone injection method was proposed to improve the catalytic process for the removal of nitrogen oxides ($NO_x$). Nitric oxide (NO) in the exhaust gas was first oxidized to nitrogen dioxide ($NO_2$) by ozone produced by dielectric barrier discharge, and then the exhaust gas containing the mixture of NO and $NO_2$ was directed to the catalytic reactor where both NO and $NO_2$ were reduced to $N_2$ in the presence of ammonia as the reducing agent. A commercially available $V_2O_5-WO_3/TiO_2$ catalyst was used as the catalytic reactor. The $NO_2$ content in the mixture of NO and $NO_2$ was changed by the amount of ozone added the exhaust gas. The effect of reaction temperature, initial $NO_x$ concentration, feed gas flow rate, and ammonia concentration on the removal of $NO_x$ at various $NO_2$ contents was examined and discussed. The increase in the content of $NO_2$ by the ozone injection remarkably improved the performance of the catalytic reactor, especially at low temperatures. The present ozone injection method appears to be promising for the improvement of the catalytic reduction of $NO_x$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.4
• /
• pp.614-619
• /
• 1997

To examine effects of drying methods on the formation of N-nitrosamine(NA) in squid during its drying. Three different types of dried products, which were made by sun, hot-air and traditional drying of squid after removal of intestines, were utilized. NA was analyzed by a gas chromatography-thermal energy analyzer. The contents of nitrate and nitrite nitrogen in dried products were in the range of 0 to 5.2mg/kg and 0 to 2.7mg/kg, respectively. The contents of TMAO and betain nitrogen in squid during its drying decreased, while those of TMA and DMA nitrogen increased. The contents in dried products were 27.8~29.2mg% and 10.4~12.3mg/kg, respectively. N-Nitrosodimethylamine (NDMA) was only detected in squid during its drying, recovery from raw sample and its dried pro- ducts spiked with 10$\mu\textrm{g}$/kg for NDPA was 81.0~ 100.0%. NDMA in raw samples was found to be below 0.05$\mu\textrm{g}$/kg. The levels of NDMA in squid increased remarkably during its drying and those in dried products were ranged from 2.7 to 42.7$\mu\textrm{g}$/kg. The effects of drying methods in squid were found to be quite different. the levels of NDMA in traditionally dried products were 11~16 and 3~4 times higher than those in sun dried and hot-air dried products, respectively It is believed that high levels of NDMA were detected in traditionally dried products because NDMA was formed from reaction between various amines and nitrogen oxide produced by combustion of briquet during drying of squid.

• Applied Chemistry for Engineering
• /
• v.24 no.4
• /
• pp.433-437
• /
• 2013

Electrical discharge plasma created in a multi-channel porous ceramic membrane-supported catalyst was applied to the decomposition of a volatile organic compound (VOC). For the purpose of improving the oxidation capability, the ceramic membrane used as a low-pressure drop catalyst support was loaded with zinc oxide photocatalyst by the incipient wetness impregnation method. Alternating current-driven discharge plasma was created inside the porous ceramic membrane to produce reactive species such as radicals, ozone, ions and excited molecules available for the decomposition of VOC. As the voltage supplied to the reactor increased, the plasma discharge gradually propagated in the radial direction, creating an uniform plasma in the entire ceramic membrane above a certain voltage. Ethylene was used as a model VOC. The ethylene decomposition efficiency was examined with experimental variables such as the specific energy density, inlet ethylene concentration and zinc oxide loading. When compared at the identical energy density, the decomposition efficiency obtained with the zinc oxide-loaded ceramic membrane was substantially higher than that of the bare membrane case. Both nitrogen and oxygen played an important role in initiating the decomposition of ethylene. The rate of the decomposition is governed by the quantity of reactive species generated by the plasma, and a strong dependence of the decomposition efficiency on the initial concentration was observed.