• Journal of Animal Environmental Science
• /
• v.18 no.2
• /
• pp.111-122
• /
• 2012

Establishment of the LFQC (Liquid Fertilizer Quality Certification) system is very urgent issue for recycling livestock manure as renewable resources in Korea faced with environmental problem of manure application to land due to intensive livestock farming. In this study, we investigated relevant laws and regulations on livestock manure fertilizer, certifications of eco-friendly agricultural products, government policies on livestock manure management to establish reasonable direction of Korean LFQC (Liquid Fertilizer Quality Certification) system. As a result from this study, the liquid fertilizers in 'LFQC' system could be classified as three levels according to the usage patterns in field; 1st. Individual Farm Level (IFL), 2nd. Joint Farm Level (JFL), and 3rd. Commercial Level (CML). And finally, we found some characteristics in 'Main Level-Grading Factors' of liquid fertilizer such as fertilizing value, harmfulness, stability, uniformity, economic effect, storage potential, commercial value, functionality. Those items were considered to be the key factors for the establishment of 'LFQC' system. More research on 'Evaluation Standards' for concrete guideline and on the 'Main Level-Grading Factors' be needed to complete Korean LFQC system.

• Geophysics and Geophysical Exploration
• /
• v.13 no.1
• /
• pp.1-8
• /
• 2010

Seismic reflection surveying is one of the most widely used and effective techniques for coal seam structure delineation and risk mitigation for underground longwall mining. However, the ability of the method can be compromised by the presence of volcanic cover. This problem arises within parts of the Bowen and Sydney Basins of Australia and seismic surveying can be unsuccessful. As a consequence, such areas are less attractive for coal mining. Techniques to improve the success of seismic surveying over basalt flows are needed. In this paper, we use elastic wave-equation-based forward modelling techniques to investigate the effects and characteristics of seismic wave propagation under different settings involving changes in basalt properties, its thickness, lateral extent, relative position to the shot position and various forms of inhomogeneity. The modelling results suggests that: 1) basalts with high impedance contrasts and multiple flows generate strong multiples and weak reflectors; 2) thin basalts have less effect than thick basalts; 3) partial basalt cover has less effect than full basalt cover; 4) low frequency seismic waves (especially at large offsets) have better penetration through the basalt than high frequency waves; and 5) the deeper the coal seams are below basalts of limited extent, the less influence the basalts will have on the wave propagation. In addition to providing insights into the issues that arise when seismic surveying under basalts, these observations suggest that careful management of seismic noise and the acquisition of long-offset seismic data with low-frequency geophones have the potential to improve the seismic results.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.11 no.2
• /
• pp.49-55
• /
• 2001

ZnO films were fabricated on p-type Si(100) wafer ITO glass and quartz glass by the sol-gel process using zinc acetate dihydrate as starting material. A homogeneous and stable solution was prepared by dissolving the zinc acetate dihydrate in a solution of 2-methoxyethanol and monoethanolamine (MEA). ZnO films were deposited by spin-coating at 2800 rpm for 25 s and were dried on a hot plate at $250^{\circ}C$ for 10 min. Crystallization of the films was carried out at $400^{\circ}C$~$800^{\circ}C$ for 1 h in air. X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), UV-vis transmittance spectroscopy, FTIR transmittance spectroscopy and Photoluminescence (PL) spectroscopy measurements have been used to study the structural and optical properties of the films. ZnO films highly oriented along the (002)plane were obtained. In all cases the films were found to be transparent (above 70%) in visible range with a sharp absorption edge at wavelengths of about 380nm, which is very close to the intrinsic band-gap of ZnO(3.2 eV). The low temperature band-edge photoluminescence revealed a complicated multi-line structure in terms of bound exciton complexes and the phonon replicas.

• Applied Chemistry for Engineering
• /
• v.26 no.3
• /
• pp.336-340
• /
• 2015

Three different types of polycarbonate (PC)/graphene oxide (GO) composites using diphenyl carbonate as a monomer were fabricated by melt polymerization. Those were the PC/GO composite (PC/GO) using a twin extruder, in-situ PC/GO composite (PC/GO-cat.) using a catalyst, and in-situ PC/GO composite (PC/GO-COCl) using a GO-COCl treated by -COCl, Chemical structures of the composites were confirmed by C-H and C=O stretching peak at $3000cm^{-1}$ and $1750cm^{-1}$, respectively. The slope for the storage (G') versus loss (G") modulus plot decreased with an increase in the heterogeneous property of polymer melts. So we can check the GO dispersion of the PC/GO composites using by the slop for G'-G" plot. According to the G'- G" slopes for three different types of PC/GO composites, GO was well dispersed within PC matrix in case of PC/GO and PC/GO-cat.. It was also confirmed by atomic force microscope (AFM) photos. One of the reasons for the poor GO dispersion of PC/GO-COCl is branching and crosslinking processes occurred during polymerization, which was further confirmed by a plot for the complex modulus versus phase difference.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.13 no.1
• /
• pp.25-37
• /
• 1993

This paper describes the use of the J-integral, a one parameter of the non-linear fracture mechanics(NLFM), as a means to measure toughness of steel fiber reinforced concrete. This parameter can be conveniently evaluated from experimentally determined load-deflection curves from flexural tests when a maximum-load failure criterion is employed. And, for high strength concrete which was reinforced steel fiber, with two different fiber length in the form of notched beams, were tested under 3-point bending, and $J_{IC}$, as well as the linear elastic fracture mechanics(LEFM) parameters $K_{IC}$ and $G_{IC}$ were evaluated. The results suggest that $J_{IC}$ is a promising fracture criterion for all of these. while $K_{IC}$(or $G_{IC}$) almost certainly are not. Also it was found that a fiber addition of less than 0.5% did not improve the fracture toughness of the high strength concrete. However, at more than 1.0% in fiber contents, $J_{IC}$ showed significant increases. reflecting the changed character of the concrete; $K_{IC}$ and $G_{IC}$ did not.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.10
• /
• pp.1189-1193
• /
• 2012

The Miniaturized Fingerprint Imager (MFI) is a slim optical mouse that can be used as an input device for application to wireless portable personnel communication devices such as smartphones. In this study, we have fabricated key optical components of an MFI, including the illumination optical components and imaging lens. An LED beam-shaping lens consisting of an aspheric lens and a Fresnel facet was successfully machined using a diamond turning machine (DTM). A customized V-shaped groove for beam path banding was fabricated by the bulk micromachining of silicon that was coated with aluminum using the shadow effect in thermal evaporation. The imaging lens and arrayed multilevel Fresnel lenses were fabricated by electron beam lithography and FAB etching, respectively. The proposed optical components are extremely compact and have high optical efficiency; therefore, they are applicable to ultraslim optical systems.

• Journal of Conservation Science
• /
• v.29 no.1
• /
• pp.55-67
• /
• 2013

This study focused on analysis condition and application method of the passive infrared thermography according to the direction and time to nondestructively detect the blistering zone of stone cultural heritage. As a result, the passive thermographic images showed different temperature characteristics by time because it sensitively reacts to air temperature, insolation and sunshine direction. In particular, the insolation and sunshine direction, which are periodically changed from 6:00 to 17:00, irregularly made surface temperature. In addition, surface temperature differences were brought on fresh zones and blistering zones except specific time since blistering causes erratic thermal transfer. As a result of examining the detection characteristics of blistering by time, the blistering was well detected between 9:00 and 10:00 when there was rapid increase in air temperature and insolation in all direction except the north. However, this study isn't considered effects of four seasons because it is carried out in autumn, and the passive thermography has difficulty to analyze the quantitative area of blistering zone. Therefore, an additional study for synthetic consideration of the passive thermography analysis about four seasons and quantitative modeling of blistering zone using the active thermography are needed.

• Tunnel and Underground Space
• /
• v.20 no.5
• /
• pp.344-351
• /
• 2010

Slip along a frictional fracture can be approached as initiation and propagation of a mode II crack along its own plane. Fracture mechanics theories predict that under pure mode II loading initiation will occur when the energy release rate of the fracture attains a critical value ($G_{IIC}$), which is generally taken as a material property. For the past few years the rock mechanics group at Purdue University has investigated experimentally the dependence of $G_{IIC}$ on normal stress and on the frictional characteristics of a fracture. A number of experiments has been conducted first on acrylic, a material that, using photoelastic methods, allows visualization of the stress field ahead of the fracture tip; and later on gypsum, a rock model material with relatively low unconfined compression strength. The experimental investigation has been expanded to include other frictional materials with higher unconfined compression strength. Direct shear tests have been conducted on specimens made with cement paste. New observations together with previous experiments indicate that $G_{IIC}$ can only be considered a material property when the peak friction angle of the discontinuity is similar to the residual friction angle; otherwise the critical energy release rate increases with normal stress.

• Journal of Popular Narrative
• /
• v.27 no.1
• /
• pp.13-51
• /
• 2021

As a case study, this paper historicizes the film culture in Namchon district in Keijo(京城) based on a preliminary research on the film ephemera produced during the colonial period. Through cross-examining articles appeared in Japanese newspapers and magazines at the time, this paper empirically reconstructs the Japanese settlers' film culture in Keijo, a colonial city whose cultural environment was ethnically divided into 'Bukchon' and 'Namchon.' During the silent era, movie theaters in the Namchon district not only played a role of cinema chain through which films imported and distributed by Japanese film companies were circulated and exhibited but also served as a cultural community for Japanese settlers who migrated to a colony. The film ephemera issued by each theater not only provided information about the movie program, but also connected these Japaneses settlers in colonial city, Keijo to the homogeneous space and time in Japan proper. Both as a minority and colonizer in a colony, these Japanese settlers experienced a sense of 'unity' that could 'distinguish' their ethnic identity differentiated from Koreans through watching movies in this ethnically segregated cultural environment. In doing so, they were also able to connect themselves to their homeland in Japan Proper, despite on a cultural level. This is a cultural practice that strengthens a kind of long distance nationalism. Examining Japanese film culture through film ephemera would not only contribute to the previous scholarship on modern theater culture and spectatorship established since the 2000s, but also be a meaningful attempt to find ways and directions for film history research through non-film materials.

• The Journal of Korean Society for Radiation Therapy
• /
• v.27 no.1
• /
• pp.31-43
• /
• 2015

Purpose : Stereotactic body radiation therapy (SBRT) has proved its efficacy in several patient populations with primary and metastatic limited tumors. Because SBRT prescription is high dose level than Conventional radiation therapy. SBRT plan is necessary for effective Organ at risk (OAR) protection and sufficient Planning target volume (PTV) dose coverage. In particular, multi-target cases may result excessive doses to OAR and hot spot due to dose overlap. This study evaluate usefulness of Volumetric modulated arc therapy (VMAT) in dosimetric and technical considerations using Flattening filter free (FFF) beam. Materials and Methods : The treatment plans for five patients, being treated on TrueBeam STx(Varian$^{TM}$, USA) with VMAT using 10MV FFF beam and Standard conformal radiotherapy (CRT) using 15MV Flattening filter (FF) beam. PTV, liver, duodenum, bowel, spinal cord, esophagus, stomach dose were evaluated using the dose volume histogram(DVH). Conformity index(CI), homogeneity index(HI), Paddick's index(PCI) for the PTV was assessed. Total Monitor unit (MU) and beam on time was assessed. Results : Average value of CI, HI and PCI for PTV was $1.381{\pm}0.028$, $1.096{\pm}0.016$, $0.944{\pm}0.473$ in VMAT and $1.381{\pm}0.042$, $1.136{\pm}0.042$, $1.534{\pm}0.465$ in CRT respectively. OAR dose in CRT plans evaluated 1.8 times higher than VMAT. Total MU in VMAT evaluated 1.3 times increase than CRT. Average beam on time was 6.8 minute in VMAT and 21.3 minute in CRT. Conclusion : VMAT for SBRT in multi-target liver cancer using FFF beam is effective treatment techniqe in dosimetric and technical considerations. VMAT decrease intra-fraction error due to treatment time shortening using high dose rate of FFF beam.