• Proceedings of the Korean Vacuum Society Conference
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• 1995.02a
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• pp.113-113
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• 1995

The adsorpption and decompposition of NO on a stepped ppt(111) surface have been studied using thermal desorpption sppectroscoppy and Auger electron sppectroscoppy. NO adsorbs molecularly in two different states of the terrace and the stepp, which are distinguishable in thermal desorpption sppectra. NO dissociates via a bent sppecies at the stepp sites on the basis of vibrational sppectrum data repported ppreviously. The dissociation of NO is activation pprocess : the activation energy is estimated to be about 2 kcal/mol. Increase in the NO dissociation with adsorpption tempperature is expplained by a pprocess controlled by different of the dissociated atomic nitrogen from the stepp to the terrace of the surface. In addition to No and N2, the desorpption ppeak of N2O is observed. We conclude that the formation of N2O is attributed to surface reaction of No and N adsorbed on the surface.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.261-262
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• 2007

This paper proposes a new IFFT(Inverse Fast Fourier Transform) algorithm, which is proper for IMDCT(Inverse Modified Discrete Cosine Transform) of MPEG-2 AAC(Advanced Audio Coding) decoder. The IFFT used in $2^N$-point IMDCT employ the bit-reverse data arrangement of inputs and N/4-IFFT to reduce the calculation cycles. We devised a new data arrangement algorithm of IFFT input and N/$4^{n+1}$-IFFT and can reduce multiplication cycles, addition cycles, and ROM size.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.186-195
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• 2016

We investigated phytoplankton and vertical inorganic nutrients at two stations around water of Ulleungdo and Dokdo in the East Sea, Korea. Nutrient addition experiments (+N, +P, +NP and +Fe) were also conducted to determine the growth response and nutrient consumption of the phytoplankton assemblage using the surface water of St. UD3 and St.50. In the field, although inorganic nutrients were low in the euphotic layer, these nutrients were increased at depths below 100 m. The total phytoplankton abundances in St. UD3 and St.50 were $4.9{\times}10^5cells\;L^{-1}$ and $1.9{\times}10^5cells\;L^{-1}$, respectively. The dominant species at St. UD3 was observed to be Raphidophyta Heterosigma akashiwo, Cryptophyta Crytomonas spp., and diatom Leptocylindrus danicus, while L. danicus and H. akashiwo including small diatom species Chaetoceros socialis were dominant at St. 50. In the nutrient addition experiments, phytoplankton growth (in vivo flourescence) in the +N and +NP treatment was 2-3 times higher than that in the +P treatment, indicating that the natural phytoplankton can respond to pulsed nutrient loading events. In addition, in vivo fluorescence in +Fe treatment was not statistically (p>0.05) different from that of the non-Fe treatments, indicating that the phytoplankton growth response in +Fe treatment was not significant. Dominant H akashiwo and L. danicus in the field showed a rapid response in nutrient additional bio-algal assay, particularly L. danicus in the +Fe treatments.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.92-98
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• 2013

Microalgal cultivation using wastewater is now regarded as essential for biodiesel production, as two goals can be achieved simultaneously; that is, nutrient removal efficiency and biomass production. Therefore, this study examined the effects of carbon sources, the N:P ratio, and the hydraulic retention time (HRT) to identify the optimal conditions for nutrient removal efficiency and biomass production. The effluent from a 2nd lagoon was used to cultivate microalgae. Whereas the algal species diversity and lipid content increased with a longer HRT, the algal biomass productivity decreased. Different carbon sources also affected the algal species composition. Diatoms were dominant with an increased pH when bicarbonate was supplied. However, 2% $CO_2$ gas led to a lower pH and the dominance of filamentous green algae with a much lower biomass productivity. Among the experiments, the highest chlorophyll-a concentration and lipid productivity were obtained with the addition of phosphate up to 0.5 mg/l P, since phosphorus was in short supply compared with nitrogen. The N and P removal efficiencies were also higher with a balanced N:P ratio, based on the addition of phosphate. Thus, optimizing the N:P ratio for the dominant algae could be critical in attaining higher algal growth, lipid productivity, and nutrient removal efficiency.

• Molecules and Cells
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• v.37 no.11
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• pp.804-811
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• 2014

The protease-activated receptor (PAR)-2 is highly expressed in endothelial cells and vascular smooth muscle cells. It plays a crucial role in regulating blood pressure via the modulation of peripheral vascular tone. Although several mechanisms have been suggested to explain PAR-2-induced hypotension, the precise mechanism remains to be elucidated. To investigate this possibility, we investigated the effects of PAR-2 activation on N-type $Ca^{2+}$ currents ($I_{Ca-N}$) in isolated neurons of the celiac ganglion (CG), which is involved in the sympathetic regulation of mesenteric artery vascular tone. PAR-2 agonists irreversibly diminished voltage-gated $Ca^{2+}$ currents ($I_{Ca}$), measured using the patch-clamp method, in rat CG neurons, whereas thrombin had little effect on $I_{Ca}$. This PAR-2-induced inhibition was almost completely prevented by ${\omega}$-CgTx, a potent N-type $Ca^{2+}$ channel blocker, suggesting the involvement of N-type $Ca^{2+}$ channels in PAR-2-induced inhibition. In addition, PAR-2 agonists inhibited $I_{Ca-N}$ in a voltage-independent manner in rat CG neurons. Moreover, PAR-2 agonists reduced action potential (AP) firing frequency as measured using the current-clamp method in rat CG neurons. This inhibition of AP firing induced by PAR-2 agonists was almost completely prevented by ${\omega}$-CgTx, indicating that PAR-2 activation may regulate the membrane excitability of peripheral sympathetic neurons through modulation of N-type $Ca^{2+}$ channels. In conclusion, the present findings demonstrate that the activation of PAR-2 suppresses peripheral sympathetic outflow by modulating N-type $Ca^{2+}$ channel activity, which appears to be involved in PAR-2-induced hypotension, in peripheral sympathetic nerve terminals.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1249-1255
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• 2011

This study examined the effect of CLA, flaxseed oil and fish oil and their combination forms on crude fat of liver and fatty acid profiles of liver, breast and thigh meat in broiler chicks. A total of 72, 1-day-old Cobb broilers were assigned to 6 groups, and fed an experimental diet supplemented with 5 different fat sources; conjugated linoleic acid (2% CLA), flaxseed oil (2% FXO), fish oil (2% FHO), CLA and flaxseed oil combination (1:1; 2% CXO), and CLA and fish oil combination (1:1; 2% CHO). Eight birds per treatment were processed, and liver, breast and thigh samples were investigated at 21 d of age. As a result of this study, most fatty acids of liver, breast and thigh meat were influenced by fat sources supplemented in the diet (p<0.05). CLA addition resulted in an increase of crude fat and saturated fatty acid (SFA) content but a concomitant decrease in n-3 to n-6 fatty acid ratio was observed in liver (p<0.05). Moreover, the same trends of SFA and n-3 to n-6 fatty acid ratio were also observed in breast and thigh meats of birds fed CLA alone. In the CXO-fed group or CHO-fed group, n-3 and n-3 to n-6 fatty acid ratio in both breast and thigh meat increased compared with CLA group, while SFA content decreased (p<0.05). FHO fed-groups had the lowest proportion of n-6 fatty acid in both breast and thigh meats compared to other fat source treatments (p<0.05). In conclusion, the increased levels of crude fat and SFA in liver and meats obtained by feeding CLA could be reduced by its combination with FXO or FHO. In addition, the combination of CLA and FXO or FHO fed to broiler chicks could increase the n-3 to n-6 fatty acid ratio of their meat along with the deposition of CLA.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.100-110
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• 1992

Arylsulfonyl urea derivatives can be easily prepared in good yield by treating amines with arylsulfonyl carbamates in aqueous solution : 1) N-Arylsulfonyl-N'-aryl urea derivatives, 2) N-Arylsulfony-N'-alkyl urea derivatives, 3) N-Arylsulfonyl-N'- heterocyclic urea derivatives. The proposed reaction mechanisms for preparing arylsulfonyl ureas involve formation of an ion-pair conformation by initial acid-base reaction, then formation of a so-called tetrahedral intermediate by nucleophilic addition, followed by an acid-catalyzed elimination of an alkoxide ion and loss of a proton.

• Archives of Plastic Surgery
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• v.45 no.1
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• pp.85-88
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• 2018

Local flaps exhibit excellent color matching that no other type of flap can compete with. Moreover, surgery using a local flap is easier and faster than surgery using a distant or free flap. However, local flaps can be much more difficult to design. We designed 2 templates to plan a V-Y rotation advancement flap. The template for a unilateral V-Y rotation advancement flap was used on the face (n=5), anterior tibia (n=1), posterior axilla (n=1), ischium (n=1), and trochanter (n=2). The template for a bilateral flap was used on the sacrum (n=8), arm (n=1), and anterior tibia (n=1). The causes of the defects were meningocele (n=3), a decubitus ulcer (n=5), pilonidal sinus (n=3), and skin tumor excision (n=10). The meningocele patients were younger than 8 days. The mean age of the adult patients was 50.4 years (range, 19-80 years). All the donor areas of the flaps were closed primarily. None of the patients experienced wound dehiscence or partial/total flap necrosis. The templates guided surgeons regarding the length and the placement of the incision for a V-Y rotation advancement flap according to the size of the wound. In addition, they could be used for the training of residents.

• Korean Journal of Materials Research
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• v.11 no.4
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• pp.294-299
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• 2001

Effects of the surface fluorination on the electrochemical charge-discharge properties of $Mg_2$Ni electrode in Ni-MH batteries fabricated by mechanical alloying were investigated. After 20h ball milling, Mg and Ni powder formed nanocrystalline $Mg_2$Ni. Discharge capacity of this alloy increased greatly at first one cycle, but due to the formation of Mg(OH)$_2$ passive layer, it showed a rapid degradation in alkaline solution within 10cyc1es. In case of 6N KOH +xN KF electrolyte (x = 0.5, 1, 2), a continuous and stable fluorinated layer formed by adding excess F$^{[-10]}$ ion, increased durability of $Mg_2$Ni electrode greatly and high rate discharge capability(90-100mAh/g). 2N KF addition led to the highest durability of all tested here. The reason of the improvement is due to thin MgF$_2$, which can prevent the $Mg_2$Ni electrode from forming Mg(OH)$_2$layer that is the main cause of degradation.

• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.441-446
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• 2023

Electrical and optical characteristics of the GaN-based light-emitting diode (LED) with the improved multi-quantum well (MQW) structure have been studied for light source in bio-sensing systems. Novel GaN/In_0.1GaN/In_0.2GaN/In_0.1GaN/GaN and Al_0.1GaN/GaN/In_0.2GaN/GaN/Al_0.1GaN (MQW) structures were suggested, and their radiative recombination rate, light output power, electroluminescence, and external quantum efficiency were compared with those of the conventional GaN/In_0.2GaN/GaN MQW structure using device simulation. The LED with the GaN/In_0.1GaN/In_0.2GaN/In_0.1GaN/GaN MQW structure showed an excellent recombination rate of 5.57 × 10²⁸ cm^-3·s^-1 that was more than one order improvement over that of the conventional LED. In addition, the efficiency droop was relieved by the suggested stepped MQW structure.