• Korean Journal of Plant Resources
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• v.8 no.2
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• pp.115-125
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• 1995

The moistures, colors and flavors of red pepper were analyzed to observe the changes of the qualities of red pepper with various conditions of drying. The moisture was 11.8%, known as optimal condition for storing red pepper, where dried at $50^{\circ}C$ for 36 and 48 hours. The color of red pepper air-dried at 50% for 48 hours was estimated to be the most execllent in comparison of sun drying and air drying. The optimal absorbances of hexnae extract from red pepper were examined. The ratios between the absorbances at 280nm and at the typical wavelengths of caretenoids(430nm, 450nm, 474nm) were from 2.5-3.4 and these wete also confirmed by the sight of the eye. Hexane fraction showed more peaks of flavors than benzene fraction and both of the two were silylated by with BSTFA to analyze the flavors by GC. CG profiles for the compositions of flavors in red perpper are thought to be useful for extimating the quality of favors in red pepper. Eight flavors including benzene dicarbozylic acid, were identified from red pepper and major components of them were oleic palmitic acids. Drying temperatures and times did not have effects on the changes of specific flavor components but did influenced the compositions of them in red pepper.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.4013-4018
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• 2014

A 0.45 $cm^2$ DSSC device with a glass/FTO/blocking layer/$TiO_2$/N719(dye)/electrolyte/50 nm-Pt/50 nm-Au/FTO/glass was prepared to examine the stability of the Au/Pt bilayered counter electrode (CE) with electrolyte and the energy conversion efficiency (ECE) of dye-sensitized solar cells (DSSCs). For comparison, a 100 nm-thick Pt only CE DSSC was also prepared using the same method. The photovoltaic properties, such as the short circuit current density ($J_{sc}$), open circuit voltage ($V_{oc}$), fill factor (FF), and ECE, were checked using a solar simulator and potentiostat with time after assembling the DSSC. The microstructure of the Au/Pt bilayer was examined by optical microscopy after 0~25 minutes. The ECE of the Pt only CE-employed DSSC was 4.60 %, which did not show time dependence. On the other hand, for the Au/Pt CE DSSC, the ECEs after 0, 5 and 15 minutes were 5.28 %, 3.64 % and 2.09 %, respectively. The corrosion areas of the Au/Pt CE determined by optical microscopy after 0, 5, and 25 minutes were 0, 21.92 and 34.06 %. These results confirmed that the ECE and catalytic activity of Au/Pt CE decreased drastically with time. Therefore, a Au/Pt CE-employed DSSC may be superior to the Pt only CE-employed one immediately after integration of the device, but it would degrade drastically with time.

• Analytical Science and Technology
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• v.13 no.5
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• pp.675-682
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• 2000

The concentration of dioxins from flue gases of municipal waste incineration facilities with capacities over 50 tons/day are regulated by the guideline: $0.1ng-TEQ/Nm^3$ for new facilities, and $0.5ng-TEQ/Nm^3$ for existing facilities and it will be strengthened to $0.1ng-TEQ/Nm^3$ until 2003 year. Dioxins from these incineration facilities have to be measured more than 2 times annually by the Official Test Facilities of Dioxins. Seven institutions have been certified so far as the Official Test Facilities of Dioxins. These facilities have to be evaluated by the quality control program provided by National Institute of Environmental Research every year. We reported the results of quality control test performed in 1999. Four institutions certified in 1998 sampled flue gases at stack of M incineration facilitiy and analyzed dioxins by Official Methods of Air Pollution. The isokinetic coefficients, the parameter for evaluation of sampling ability were excellent for all four institutions. They were 100.9%, 102.4%, 102.1% and 99.2%, respectively. The criteria required are as follows; resolution over 10,000, mass calibration within ${\pm}5ppm$, ion abundance ratio within 15%, and the recovery of 50-120%. As results, those institutions also met these parameters of Official Method of Air Pollution.

• Membrane Journal
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• v.21 no.1
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• pp.84-90
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• 2011

We studied the effects of induction of natural convection instability flow (NCIF) according to the gravitational orientation (inclined angle) of the membrane cell on the reduction of membrane fouling in ultrafiltration (UF) of colloidal silica solutions. Five colloidal silica solutions with different silica size (average size = 7, 12, 22, 50 and 78 nm) were used as UF test solutions. The silica particles in colloidal solutions form cakes on the membrane surface thereby causing severe reduction in the flux. The UF performance according to the gravitational orientation of the membrane cell (from 0 to $180^{\circ}$ inclined angle), was examined in an unstirred dead-end cell. We evaluate the effects of NCIF on membrane performance as the flux enhancement ($E_i$). In the dead-end UF of smaller size (7, 12 and 22 nm) silica colloidal solutions, changing the gravitational orientation (inclined angle) of the membrane cell induces NCIF in the membrane module and higher inclined angle and smaller size silica colloidal solution offer more stronger NCIF. This induced NCIF enhances back transport of the deposited silica solutes away from the membrane surface, therefore gives for the improvement of permeate flux. But in UF of more larger size (50 and 78 nm) silica colloidal solutions, NCIF effects are not appearing. These results suggest that the size of colloidal particle affects the extent of NCIF occurrence.

• Applied Biological Chemistry
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• v.39 no.3
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• pp.245-248
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• 1996

Thermal stability of the major color component, cyanidin 3-glucoside, isolated from Korean pigmented rice (Oryza sativa var. Suwon 415) were investigated to explore possible application of value-added natural colors as food additives. The anthocyanin showed red and blue color with maximum absorption peaks at 511 nm and 572 nm in acidic (pH 2.0) and alkaline (pH 9.0) buffer solutions, respectively, and the thermal degradation reactions were carried out with different temperature ranges at $50{\sim}95^{\circ}C$. Degree of degradation was determined with UV/Vis spectra which indicate characteristic absorption patterns with sharp isosbestic points at 350 nm (pH 2.0), and 275, 310, and 405 nm (pH 9.0). Thus the reaction follows simple first-order kinetics. The anthocyanin was very stable against heat at acidic pH and relatively stable at alkaline pH with half-life values of 50.3 hr and 0.6 hr at $70^{\circ}C$, respectively. The activation energies and Arrhenius frequency factors of the pigment were 26.9 kcal $mol^{-1}\;and\;6.0{\times}10^{11}\;s^{-1}$, at pH 2.0, and 15.2 kcal $mol^{-1}\;and\;1.4{\times}10^{6}\;s^{-1}$, pH 9.0, and respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.12
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• pp.1-7
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• 2001

Single-layer polymer green electroluminescent devices were fabricated with novel material synthesis by using moleculely-dispersed TTA and NIDI into the polymer PC(B79) emitter layer doped with C6 fluorescent dye which has low operating voltage and high quantum efficiency. A EL cell structure of glass substrate/indium-tin-oxide/PC:TTA:NIDI:C6/Ca/Al was employed and compared with various low work function cathode electrodes Ca and Mg metals. By adjusting the concentration of the fluorescent dye C6, low turn-on voltage of 2.4V was obtained, maximum quantum efficiency of 0.52% at 0.08mole% has been improved by about a factor of ~50 times in comparison with the undoped cell. The PL and EL colors can't be turned by changing the concentration of the C6 dopant. PL emission peaking was obtained at 495nm and EL emission peaking at 520nm with FWHM ~70nm

• Journal of the Korean institute of surface engineering
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• v.50 no.3
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• pp.170-176
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• 2017

EPIG (Electroless Pd/immersion Au) process was studied to replace ENIG (electroless Ni/immersion Au) and ENEPIG (electroless Ni/electroless Pd/immersion Au) processes for bump surface treatment used in high reliable flip chip packages. The palladium and gold layers formed by EPIG process were uniform with thickness of 125 nm and 34.5 nm, respectively. EPAG (Electroless Pd/autocatalytic Au) also produced even layers of palladium and gold with the thickness of 115 nm and 100 nm. TEM results exhibited that the gold layer in EPIG surface had crystalline structure while the palladium layer was amorphous one. After annealing at 250 nm, XPS analysis indicated that the palladium layer with thickness more than 22~33 nm could act as a diffusion barrier of copper interconnects. As a result of comparing the chip shear strength obtained from ENIG and EPIG surfaces, it was confirmed that the bonding strength was similar each other as 12.337 kg and 12.330 kg, respectively.

• Journal of the Korean Chemical Society
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• v.46 no.3
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• pp.242-251
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• 2002

We report the synthesis and characterization of the perovskite nanotubes made by sol-gel template syn-thesis.Both lead titanate (PbTiO3 : PT), lead zirconate (PbZrO3 : PZ) and lead zirconium titanate (PbZrO3 -PbTiO3 : PZT) solid solution nanotubes were prepared with a chelate sol-gel of titanium isopropoxide (Ti(OPri)4 ), zirconium tet-rabutoxide (Zr(OBu)4 ) and the respective lead acetate (Pb(OAc)2 -3H2O). WhatmanRanodisc membranes, with a 200nm pore size, served as the template. After the removal of the template in the 6M-NaOH, scanning electron microscopy shows that the shapes formed are 200 nm outer diameter tubes with 50mm lengths. Transmission electron microscopy and electron diffraction reveal that the tubes are polycrystalline. The PT nanotubes so far have shown an anomalous transition temperature, 234.4$^{\circ}C$ as measured by DSC with a small particle size, 15.4 nm determined by X-ray analysis with the aid of Scherrer's equation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.300-305
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• 1987

Changes in pigments of freeze dried grasshopper in refrigerator were determined to asses the storage stability. In storage at $5^{\circ}C$, chlorophyll contents were drastically decreased but pheopytins were increased. The degradation of chlorophylls get under controlled with vacuum package. The pigments extracted from 98 days stored samples were fractionated by silicic acid column and obtained 3 portions (3a, 3b and 3d). These portions were compared Rf values (0.75, 0.56, 0.50, respectively) and absorption spectra (408, 666nm; 419, 651nm; 433, 655nm, respectively) with that of standard and were identifed pheophytin a and b and 'changed' chlorophyll a. Especially, pheophytins a and b were great strength accelerated to lipid oxidation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.269-275
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• 2003

Polysilicon-oxide-nitride-oxide-silicon(SONOS) transistors were fabricated by using 0.35${\mu}{\textrm}{m}$ complementary metal-oxide-semiconductor(CMOS) process technology to realize a low voltage programmable flash memory. The thickness of the tunnel oxide, the nitride, and the blocking oxide were 2.4nm, 4.0nm, and 2.5nm, respectively, and the cell area of the SONOS memory was 1.32$\mu$$m^2$. The SONOS device revealed a maximum memory window of 1.76V with a switching time of 50ms at 10V programming, as a result of the scaling effect of the nitride. In spite of scaling of nitride thickness, memory window of 0.5V was maintained at the end of 10 years, and the endurance level was at least 105 program/erase cycles. Over-erase, which was shown seriously in floating gate device, was not shown in SONOS device.