• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1081-1089
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• 2005

In order to examine the application feasibility of Orimulsion fuel in a commercial boiler using heavy fuel oil, a numerical and experimental research efforts have been made especially to figure out the fundamental combustion characteristics of this fuel in a small-scale boiler. One of the notable combustion features of Orimulsion fuel is the delayed appearance of flame location with the flame shape of rather broad distribution, which is found experimentally and confirmed by numerical calculation. This kind of flame characteristics is considered due to the high moisture content included inherently in the process of Orimulsion manufacture together with micro-explosion by the existence of fine water droplets. In order to investigate the effect on the combustion characteristics of Orimulsion, a series of parametric investigation have been made in terms of important design and operational variables such as injected amount of fuel, types of atomization fluid, and phonemenological radiation model employed in the calculation, etc. The delayed feature of peak flame can be alleviated by the adjustment of the flow rate of injected fuel and the generating features of CO, $SO_2$ and NO gases are also evaluated in the boiler. When the steam injection as atomizing fluid is used, the combustion process is stabilized with the reduced region of high flame temperature. In general, the calculation results are physically acceptable and consistent but some refinements of phenomenological models are necessary for the better resolution of pollutant formation. From the results of this small-scale Orimulsion boiler, it is believed that a number of useful information are obtained with the working computer program for the near future application of Orimulsion fuel to a conventional boiler.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.286-292
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• 2005

This study is to investigate the industrial boiler which can be significantly affected by the restriction of NOx. Note that the application of SNCR method to industrial boiler is usually blown as not feasible due to the insufficient residence time for proper mixing. The purpose of this study is to investigate the applicability of the SNCR system application to the industrial boiler, which produces 40 tons of steam per hour using heavy oil. For the industrial boiler with 3-D rectangular coordinate, the general coding are made fur various turbulence modeling such as turbulent flow, turbulent fuel combustion, thermal NO formation and destruction together with the NO reaction with reducing agents. Further, the incorporation of drop trajectory model is successfully made in 3-D rectangular coordinate with Lagrangian frame and the main swirl burner effect on the characteristics of flame is considered. As expected a short flame was created and thereby NOx is removed more efficiently by increasing the proper region of temperature for NO reduction reaction. The validation of program was made successfully by the comparison of experimental data. Based on the reliable calculation results, the SNCR method in a industrial boiler shows the possibility as one of viable NO reduction method by the use of well designed mixing air of reducing agent.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.795-800
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• 2009

In this study, the $CO_2$ removal characteristics of the Vortex tube type absorbtion apparatus were investigated to enhance the compactness of $CO_2$ absorption process and to reduce the amount of absorbing solution of the $CO_2$ separation process. The Vortex tube with the diameter of 17 mm and the length of 250mm was introduced in the experimental apparatus to treat $20Nm^3/hr$ of $CO_2$ containing flue gas. The flue gases for experiments containing 11~13 vol% of $CO_2$ were supplied from the coal-firing CFBC power plant with 12 ton/hr of steam producing capacity. The mixed solutions of 20 wt% of MEA as base solution with the adding solutions like HMDA, AMP and KOH were used as absorbents. The experiments were executed under the various conditions like the absorbing solution concentrations in the range of 20 to 50 wt%, the flow rate of $CO_2$ containing flue gases in the range of 6 to $15Nm^3/hr$ and the flow rate of absorbing solution in the range of 1.0 to 3.0 l/min. As a results, the $CO_2$ removal efficiency of mixed absorbent of 20 wt% of MEA with HMDA was remarkable. From this study, we concluded that the efficient separation of $CO_2$ from flue gases using the features of the Vortex tube type absorbing unit for gas/liquid contact and the separation of gas/liquid be possible. But more works are needed to increase the $CO_2$ removal efficiency of Vortex tube process.

• YAKHAK HOEJI
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• v.54 no.4
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• pp.215-225
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• 2010

To investigate effects of pine essential oil isolated by steam distillation from Pinus densiflora needles (PN) and twigs (PT) on anti-oxidant and anti-aging activities, the experiments were carried out to determine anti-oxidant and antiaging activities on DPPH radical scavenging activity, NBT/xanthine oxidase-superoxide scavenging activity, silica-induced intracellular $H_2O_2$ and hydroxyl radical generation in RAW264.7 cells, hyaluronidase and elastase activities in vitro. Essential oil of PN and PT were contained 0.225 and 0.176 (w/v) %, respectively. PN was contained with 30 kinds of essential oil and its major constituent is $\alpha$-pinene (21.5%). Further PT was contained with 40 kinds of essential oil and its major constituent is $\beta$-pinene (22.4%) in GC/MS assay. Other essential oils of PN were $\beta$-pinene, camphene, myrcene, limonene, terpinolene, $\alpha$-terpineol, bornyl acetate, $\alpha$-copaene, caryophellene and humulene and PT were $\alpha$-pinene, camphene, phellandrene, limonene, terpinolene, $\alpha$-terpineol, bornyl acetate, $\alpha$-copaene, caryophellene and humulene. The essential oil of PT have more active than that of PN in anti-oxidant activity which has significant DPPH radical and superoxide scavenging activity, and significant inhibitory activities on silica-induced intracellular $H_2O_2$ and hydroxyl radical generation, as well as, significantly inhibited elastase and hyaluronidase activities. Further, phellandrene, myrcene and $\alpha$-pinene have DPPH radical and superoxide scavenging activities, $\beta$-pinene, terpinolene, myrcene and phellandrene inhibited silica-induced intracellular $H_2O_2$ and hydroxyl radical generations. And also phellandrene and $\beta$-pinene inhibited hyaluronidase and elastase activities. In conclusion, the essential oils isolated from PN and PT have anti-oxidant and anti-aging activities.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.95-101
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• 2016

In the present study, we extracted the hydrosol from flower of Chrysanthemum boreale Makino (CBMF hydrosol) by steam distillation and tested the effect of the CBMF hydrosol on skin regeneration using normal human keratinocytes (HaCaTs). CBMF hydrosol induced proliferation as well as migration in HaCaTs in a dose-dependent manner. Treatment with $1{\mu}g/mL$ CBMF hydrosol increased proliferation to $143.71{\pm}3.37%$ and migration to $139.98{\pm}5.72%$ compared with a control group. CBMF hydrosol also significantly enhanced the phosphorylations of extracellular signal-regulated kinase (Erk) 1/2 and serine/threonine-specific protein kinase (Akt) in HaCaTs. Moreover, CBMF hydrosol dose-dependently induced sprout outgrowth in HaCaTs. These results demonstrate that CBMF hydrosol has skin regeneration and wound healing activity in HaCaTs. Therefore, CBMF hydrosol could be used as a potential cosmetic material.

• Korean Journal of Materials Research
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• v.21 no.1
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• pp.1-7
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• 2011

Methods of producing hydrogen include steam reforming, electrochemical decomposition of water, and the SI process. Among these methods, the Sulfur iodine process is one of the most promising processes for hydrogen production. The thermochemical sulfur-iodine (SI) process uses heat from a high-temperature-gas nuclear reactor to produce $H_2$ gas; this process is known for its production of clean energy as it does not emit $CO_2$ from water. But the SI-process takes place in an extremely corrosive environment for the materials. To endure SI environments, the materials for the SI environment will have to have strong corrosion resistance. This work studies the corrosion resistances of the Fe-Si, Ni-Ti and Ni Alloys, which are tested in SI-process environments. Among the SI-process environments, the conditions of boiling sulfuric acid and decomposed sulfuric acid are selected in this study. Before testing in boiling sulfuric acid environments, the specimens of Fe-4.5Si, Fe-6Si, Ni-4.5Si, Ni-Ti-Si-Nb and Ni-Ti-Si-Nb-B are previously given heat treatment at $1000^{\circ}C$ for 48 hrs. The reason for this heat treatment is that those specimens have a passive film on the surface. The specimens are immersed for 3~14 days in 98wt% boiling sulfuric acid. Corrosion rates are measured by using the weight change after immersion. The corrosion rates of the Fe-6Si and Ni-Ti-Si-Nb-B are found to decrease as the time passes. The corrosion rates of Fe-6si and Ni-Ti-Si-Nb-B are measured at 0.056 mm/yr and 0.16 mm/yr, respectively. Hastelloy-X, Alloy 617, Alloy 800H and Haynes 230 are tested in the decomposed sulfuric acid for one day. Alloy 800H was found to show the best corrosion resistance among the materials. The corrosion rate of Alloy 800H is measured at -0.35 mm/yr. In these results, the corrosion resistance of materials depends on the stability of the oxide film formed on the surface. After testing in boiling sulfuric acid and in decomposed sulfuric acid environments, the surfaces and compositions of specimens are analyzed by SEM and EDX.

• Nuclear Engineering and Technology
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• v.25 no.2
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• pp.276-284
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• 1993

The ABB-CE System-80 reactor power cutback system(RPCS) is designed to enable continuous operation of the reactor without trip in the events of the loss of one of the two main feedwater pumps and loss of load, and thus improves plant availability in a cost effective manner. In this study expansion of RPCS has been investigated for continuous reactor operation without trip in the event of an inward control element assembly(CEA) deviation including a single rod drop. Under the expanded function of RPCS the control system will provide a rapid core power reduction on demand by releasing CEAs to drop into the core and reduce the turbine power, if necessary, to follow the reactor power variation. This design feature which is included as the new design features to be incorporated in the ABB-CE System-80+ meets the EPRI advanced light water reactor(ALWR) requirements. For this study core analysis models of System-80+ have been developed to simulate the nuclear steam supply system(NSSS) response as well as the RPCS initiation of rapid CEA insertion. The results of this study demonstrate that the reactor trip can be avoided in the event of inward CEA deviation including a single rod drop by the RPCS initiation and thus the plant availability and capacity factor would be increased.

• Journal of Welding and Joining
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• v.15 no.1
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• pp.92-100
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• 1997

Weld repair of ASTM A-470 class 8 high pressure (HP) steam turbine rotor steel has been performed to extend the service life of older fossil units. Microhardness measurements were conducted across the weldment from unaffected base metal (BM) to weld metal (WM). The hardness of the BM was VHN 253, however it dropped up to VHN 227 at the heat affected zone (HAZ) close to unaffected BM for multipass SAW. This area of hardness drop is called "siftening zone" and has a width of 0.5-0.6mm. During creep rupture test, failure occurred around the softening zone and rupture time was 772.4hr at 19Ksi (132 Mpa) and 593.deg. C. Multipass MIG and TIG welding have been employed to reduce the softening zone width. The softening zone width for MIG was 0.3-0.4mm and for TIG was zero-0.4mm depending on heat inputs. However creep rupture time was decreased as softening zone width reduced. Creep rupture time also showed a close relationship with heat inputs in TIG process. The higher heat input, the longer rupture time. Most failure occurred at intercritical HAZ (ICHAZ), however rupture location was shifted to coarse grained HAZ (CGHAZ) as heat input decreased. The rupture surface showed tearing and dimple which indicated transgranular fracture. fracture.

• Food Science and Preservation
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• v.10 no.1
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• pp.75-79
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• 2003

Total nitrogen(TN) contents in all samples were in the range of 308.3 to 925.9 mg% and TN value of kanjang prepared with high pressure(HPK)-heated bean was lower than that of normal pressure(NPK) and steam(SPK)-heated bean. TN content was slightly increased according to the heating time of bean. Amino type nitrogen(AIN) contents in all samples were in the range of 133 to 451.5 mg％ and AIN value of NPK(451.5 mg%) was higher than that of HPK(133∼171.5 mg%) and SPK(178.9∼224 mg%). Ammonia type nitrogen(AON) contents in all samples were in the range of 23.5 to 142.0 mg% and AON value of HPK was lower than that of HPK and SPK. Free amino acid(FA) contents in all samples were in the range of 133 to 451.5 mg%, and then FA content of NPK was higher than that of SPK(178.9∼224 mg%) and HPK(133 ∼171.5 mg%). Lightness(L) value of Hunter color in all samples were in the range of 45.13 to 49.08 and was similar with each other. Redness(a) and yellowness(b) value were in the range of 25.30∼34.43 and 52.55∼74.13, respectively.

• Food Science and Preservation
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• v.5 no.3
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• pp.270-274
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• 1998

In order to enhance the availability of Korean loquat fruit, loquat juice was manufactured and its physicochemical characteristics are measured. The juice of raw fruit and pressed juice after blanching with steam that the pH, sugars, total acids and yields were 3.4, 3.6, and 8.5, 8.0 $^{\circ}$ Brix, and 0.36, 0.34%, and 53.2, 57.4% respectively. Four groups of juices were processed as followed. A ; juice of clarified after filteration, B ; pressed and filtered juice of raw fruit in refrigerated for 50 days, C ; clarified juice of heated at 90$^{\circ}C$ for 2 min., D ; clarified juice of blanched and pressed with raw fruit. Total acids, pH and sugars of A, B, C and D juices were 0.27, 0.35, 0.29 and 0.28%, and 3.80, 3.10, 3.68 and 3.71, and 7.5, 8.5, 8.0 and 8.2 $^{\circ}$Brix, respectively. Juice of B was higher total free sugar and organic acid than others. The chromaticity of D juice was stable than others. In the sensory test of loquat juice, that the product showed excellent result at 11 $^{\circ}$Brix and pH 3.78 when 4% of fructose and 0.05% of citric acid added.