• Journal of the Korean Institute of Rural Architecture
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• v.10 no.4
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• pp.25-32
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• 2008

The prevention of disasters in cultural property is very important management and historical duties. The reason can't be measured values with monetary scale of our contemporary. Therefore, this paper was considered fire-safety as one of terrible threat-disasters about the wooden buildings. This research deal with 47 cases cultural property wooden building by whole investigation(field survey and interview) in Gangnung province. The most buildings have basic fire extinguisher; ABC powder. A few buildings are rarely installed fire extinguishing equipments; outdoor fire hydrant, heat sensor, ground sprinkler, CO2-hose-reel. But these state is very insufficient for the fire-safety in cultural property wooden buildings. Specially as particular attention in province, forest fire of regional characteristic have close relation with cultural property fire. The majority of factor against forest and building fire is to provide monitoring and security system; CCTV, Fence, Sensor, Alarm and paid guard man against incendiary. Ultimately it is necessary to construct comprehensive disaster prevention system with the organic cooperation such as National Emergency Management Agency, Cultural Heritage Administration, Forest Service, local government officials and regional citizen.

• Resources Recycling
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• v.8 no.4
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• pp.30-38
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• 1999

High 1emperiltur.e propeitles o i cold bonded pellet based on lroll beanng dusts wele invesligaled prim to using as a burden m blasl furnaces, Major conclusions ould be summarized Io llows: the cold bonded pellet needed to bc produced by the characteristic criterion on high lempemhIre prapcrttes as well as a compressive sncnglh. Basicity of cold bonded pellel shruld be linted to be appoxiiniltely 1.7 in order to maintain appropriate softcn~nga nd rnelt~ngp ropcrlies. On thc other hand. basiciq greater than 2.6 showed exce\ulcornersive puessure drop due to powder gelleratlon. Potcntialil], of blast fi~rnaccs lag as binding malerial in m a h g cold ba~~deprel llels !\.us also certified in viewpoinls of high temperature properly.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.900-902
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• 2003

Critical current($I_c$) degradation of HTS tapes after bending is one of the holiest issues in HTS development and application studies. Many people are measuring $I_c$ degradations for effect of tending radius. However even if the bending radius is larger than the breaking radius a HTS tapes can be damaged by repetitive bending, which is unavoidable in the winding processes. Therefore, We studied the $I_c$ degradation after repetitive bending, at 77K with self-field, of Bi-2223 tapes processed by "Powder-in-Tube" technique, which was made by America Superconductor Corporation(AMSC), Innova Superconductor Technology(InnoST) and Korea Electro-technology Research Institute(KERI). For each specimen $I_c$ degradation was measured various bending radius as function of repetitive bending number.

• Macromolecular Research
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• v.11 no.1
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• pp.14-18
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• 2003

Grafting of glycidyl methacrylate (GMA) upon coralline hydroxyapatite in conjugation with demineralized bone matrix (CHA-DBM) using equal molar ratio of potassium persulfate/sodium metabisulfite redox initiating system was investigated in aqueous medium. The optimum reaction condition was standardized by varying the concentrations of backbone, monomer, initiator, temperature and time. The results obtained imply that the percent grafting was found to increase initially and then decrease in most of the cases. The optimum temperature and time were found to be 50 $^{\circ}C$ and 180 min, respectively, to obtain higher grafting yield. Fourier transform infrared (FT-IR) spectroscopy and X-ray powder diffraction (XRD) method were employed for the proof of grafting. The FT-IR spectrum of grafted CHA-DBM showed epoxy groups at 905 and 853 $cm^{-1}$ / and ester carbonyl group at 1731 $cm^{-1}$ / of poly(glycidyl methacrylate) (PGMA) in addition to the characteristic absorptions of CHA-DBM, which provides evidence of the grafting. The XRD results clearly indicated that the crystallographic structure of the grafted CHA-DBM has not changed due to the grafting reaction. Further, no phase transformation was detected by the XRD analysis, which suggests that the PGMA is grafted only on the surface of CHA-DBM backbone. The grafted CHA-DBM will have better functionality because of their surface modification and hence they may be more useful in coupling of therapeutic agents through epoxy groups apart from being used as osteogenic material.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.767-773
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• 2019

The thermal diffusion performance of the electronic device is a factor for evaluating the stability of the electronic device. Therefore, many of research have been conducted to improve the thermal characteristics of thermal interface materials, which are materials for thermal diffusion of electronic products. In this study, nano thermal grease was prepared by blending graphene, silver and copper nano powders into a thermal grease, a type of thermal interface materials, and the heat transfer rate was measured and compared for the purpose of investigating the improved thermal properties. As a result, the thermal properties were good in the order of graphene, silver and copper, which is thought to be due to the different thermal properties of the nano powder itself.

• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.752-758
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• 1994

Several one-electron reduction products of ${\gamma}$(1,2)-[$H_nSiV_2W_{10}O_{40}]^{(6-n)-}$ were separated by precipitating or coprecipitating with diamagnetic host compounds at different pH. Mono-and diprotonated species, 1 and 2, in powder samples exhibit aPR spectra characteristic of a mononuclear oxovanadium species, indicating that the unpaired electron is trapped at one vanadium atom. The EPR spectrum of the unprotonated species 0 shows 15 parallel lines, indicating that the unpaired electron interacts equally with two vanadium atoms. While different species were precipitated depending upon the pH of the solution and the charge of the host anion, only one species 1' was formed in the frozen solutions at pH 3.2-4.7. The EPR spectrum of 1' indicates that the unpaired electron is trapped at one vanadium atom and 1/16 of the spin density is delocalized onto the second vanadium atom. The species 1' is probably another form of the monoprotonated species. The EPR spectra show that some of 2 transform into 1 and some of 0 transform into 1' in the solid state at low temperatures. It is suggested that proton transfer between the heteropolyanion and water molecues in the solid state is involved in these transformations.

• Transactions of Materials Processing
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• v.30 no.3
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• pp.109-118
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• 2021

Recently, there has been an increased interest in the remanufacturing of mechanical parts using metal additive manufacturing processes in regards to resource recycling and carbon neutrality. DED (directed energy deposition) process can create desired metallic shapes on both even and uneven substrate via line-by-line deposition. Hence, DED process is very useful for the repair, retrofit and remanufacturing of mechanical parts with irregular damages. The objective of the current paper is to investigate the effects DED process parameters, including the effects of power and the scan speed of the laser, on deposition and residual stress characteristics for remanufacturing of mechanical parts using experiments and finite element analyses (FEAs). AISI 1045 is used as the substrate material and the feeding powder. The characteristic dimensions of the bead shape and the heat affected zone (HAZ) for different deposition conditions are obtained from the experimental results. Efficiencies of the heat flux model for different deposition conditions are estimated by the comparison of the results of FEAs with those of experiments in terms of the width and the depth of HAZ. In addition, the influence of the process parameters on residual stress distributions in the vicinity of the deposited region is investigated using the results of FEAs. Finally, a suitable deposition condition is predicted in regards to the bead formation and the residual stress.

• Advances in nano research
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• v.12 no.4
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• pp.415-426
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• 2022

Nickel substituted cobalt-zinc ferrite nanoparticles with composition Co_0.5Zn_0.5Ni_xFe_2-xO₄ (x = 0.25, 0.5, 0.75, 1.0) were synthesized using a wet chemical method named citrate precursor method. Various characterizations of the prepared nanoferrites were done using X-ray powder diffractometry (XRD), Scanning electron microscopy (SEM), UV visible spectroscopy and Fourier transform spectroscopy technique (FT-IR). XRD confirmed the formation of cubic spinel structure of the samples with single phase having one characteristic peak at (311). The value of optical band gap (E_g) was found to decrease with Ni substitution and have values in the range 2.30eV to 1.69eV. A Fenton-type system was created by photocatalytic activity using source of visible light for removal of methylene blue dye. Observations revealed increase in the degradation of methylene blue dye with increasing nickel content in the samples. The degradation percentage was increased from 77.32% for x = 0.25 to 90.16% for x = 1.0 in one hour under the irradiation of visible light. Also, the degradation process was found to have pseudo first order kinetics model. Hence, it can be observed that synthesized nickel doped cobalt-zinc ferrites have good capability for water purification and its degradation efficiency enhanced with increase in nickel concentration.

• Food Science and Preservation
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• v.31 no.2
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• pp.245-255
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• 2024

The proximate composition, quality characteristics, antioxidant activity, and sensory evaluation scores of yakgwa added with mealworm powder (MP) were examined. MP contained 5.83 wt% moisture, 55.70 wt% crude protein, 35.96 wt% crude fat, 3.70 wt% crude ash, and 2.43 wt% carbohydrate and feature total polyphenol and flavonoid contents of 406.52 mg GAE/100 g and 21.18 mg NE/100 g, respectively. The DPPH and ABTS^•+ radical scavenging activities and the reducing power of MP were determined as 90.25%, 44.06%, and 1.74, respectively. Except for moisture and carbohydrate content, the proximate composition of mealworm yakgwa (MY) increased with the amount of MP increased. The pH of the dough increased with the addition of MP, whereas the expansion degree tended to decrease. Sugar content was highest at MP contents of 0 wt% and 12 wt% (FM4 group), and hardness was lowest in the FM4 group. With the increasing MP content, the L, b values and antioxidant activity increased, whereas a value decreased. The sensory evaluation scores for the overall preference, appearance, color, and taste were lowest in the FM4 group. These results suggested that MP contents of 6-9 wt% were optimal for mealworm-based yakgwa.

• Food Science and Preservation
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• v.9 no.3
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• pp.304-308
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• 2002

Quality characteristic of cookies processed with hot water extract powder from masted safflower seed(RSHE) was investigated. Proximate compositions of RSHE were 4.7% of moisture, 32.6% of crude protein, 6.5% of crude ash. Composition of fatty acids(91.4%) were 77.14% of linoleic acid and 12.12% of oleic acid in RSHE. Glutamic acid, aspatic acid, arginine and glycine were major amino acids. Asparagine(12.69 ㎎/g) and arginine(1.13 ㎎/g) were contented high level in free amino acid of RSHE. The major minerals of RSHE were K(41.95 ㎎/g) and Mg(4.63 ㎎/g). 'L' value of cookies with RSHE were decreased, but 'a' value were increased. The breaking force and hardness of cookies with RSHE were higher than those of control. Thickness of cookies with RSHE were thicker than those of control and RSP(powder from roasted safflower seed). By sensory evaluation of cookies, appearance, taste, texture and overall acceptability score of cookie with 0.1% RSHE recorded first rank.