• Resources Recycling
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• v.18 no.5
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• pp.63-71
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• 2009

Recyclable wastes coming into material recovery facilities(MRFs) is mostly packed by plastic bag or sack bag. Bag rupturing device is essential to improve capacity and efficiency of MRFs. Bag opening works of MRFs is mostly done by numerous workers and shredder-type bag rupturing device. It often makes a problems; decreased capacity, shredded recyclables, worker safety by explosion and broken glasses, etc. In the present work, bag rupturing device with octagonal rotating blade drums has been developed to solve the existing problems and environment assessment is also performed during operation of the device. Capacity of the device was about 5.6 ton/hr at 8.2 rpm of drum revolution speed and 1.25 m/min of belt conveyor speed. It satisfied initial designed capacity(5.0 ton/hr) and max. capacity 8.8 ton/hr was achieved at 12.5 rpm of drum revolution speed and 1.50m/min of belt conveyor speed. Bag rupturing efficiencies on outer and inner bag were obtained at 100% and about 95.6% as average, respectively and original form of glass bottles in the bag was maintained without broken by about 96.5%. This result shows that the safety in hand sorting by the workers could be improved. As result of environmental assessment on the noise, vibration and particulates, the measured levels on noise, vibration and particulates show the below standard regulatory limits. It could be concluded that the problems of existing devices in MRFs could be solved by adopting the bag rupturing device with octagonal rotating blade drums in on-site operation.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.287-301
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• 2019

Preservation of the original form is the principle for conservation, management and utilization of cultural heritages. Thus, non-destructive analysis of these samples are important field of the conservation science. In this study, examined the applicability of nondestructive surface X-ray diffraction analysis (ND-XRD) for cultural heritage by materials (rock specimen, jade stone, pigment painted specimen, earthen artifact, metal artifact). In result, all type of sample is recorded suitable X-ray diffraction patterns for identifying mineral composition in case of surface condition with adequate particle size and arrangement. And diffraction pattern is reflected surface information than matrix. Therefore, ND-XRD is thought to be applicable not only mineral identification but also interpretation of manufacturing technique and alteration trend about layered sample (in horizontally or vertically). Whereas some exceptional diffraction patterns were recorded due to overlapping information on specific crystal planes. It caused by skip the sample treatment (powdering and randomly orientation). It could be advantageously used for mineral identification, such as preferred orientation of clay minerals. In contrast, irregular diffraction pattern caused by single crystalline effect is required careful evaluation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2430-2434
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• 2005

Automatic FPC punching instrument for the improvement of working condition and cost saving is introduced in this paper. FPC(flexible printed circuit) is used to detect the contact position of K/B and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, the accuracy of the punching degree is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used for the sake of cost down instead of using high quality vision systems for the FA. 3D Mechanical design tool(Pro/E) is used to manage the exact tolerance circumstances and avoid design failures. Simulation is performed to make the complete vision based punching machine before assembly, and this procedure led to the manufacturing cost saving. As the image processing algorithms, dilation, erosion, and threshold calculation is applied to obtain an exact center position from the FPC print marks. These image processing algorithms made the original images having various noises have clean binary pixels which is easy to calculate the center position of print marks. Moment and Least square method are used to calculate the center position of objects. In this development circumstance, Moment method was superior to the Least square one at the calculation of speed and against noise. Main control panel is programmed by Visual C++ and graphical Active X for the whole management of vision based automatic punching machine. Operating modes like manual, calibration, and automatic mode are added to the main control panel for the compensation of bad FPC print conditions and mechanical tolerance occurring in the case of punch and die reassembly. Test algorithms and programs showed good results to the designed automatic punching system and led to the increase of productivity and huge cost down to law material like FPC by avoiding bad quality.

• The International Journal of Costume Culture
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• v.13 no.2
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• pp.141-153
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• 2010

Fashion needs to be understood as practicality and creative behavior and various movements of paintings act as inspirations of original design for fashion designers. This study seeks to find sources of fashion designs in the works of Mark Rothko who is in the center of color-field abstract. Color-field of Rothko provides infinite inspirations as colors are identically treated as shapes and lighting and textures are all included on top of it. In this study, the purpose is to create color focused artistic fashion design by exploring the possibility of expression with the colors of Rothko as the main motive. The study method is as follows. First, the concept and significance of color-field abstract are researched through documented data. Works of Rothko is divided into three periods according to their characteristics. The background of the formation of color-field abstract of Rothko is understood by analyzing the trends of the works in each period. Second, twenty representative works from 1949 to 1969 are selected and analyzed in formative components of color, shape and textures in order to more accurately understand shape of colors, brilliance, simplicity that appear in the mature color-field abstract of Rothko. Third, preexisting methods of color-field of paintings developed into motives of clothing are studied focusing on the collections from 1997 to 2006. Examples of applications of color-field images in modern fashion designs are analyzed. Fourth, motives are selected based on general characteristics of color-field abstract of Rothko and the results of the formative analysis. Clothing is produced that expresses the colors of the paintings of Rothko more effectively. As the results of the study, restrained shapes and textures and various forms of color combinations shown in color-field abstract of Rothko provided deep inspirations on material composition and color planning for fashion design focused on colors. Additionally, needle-punching technique using wool for the production technique enabled relief texture expressions of materials by colors and effective applications of soft and warm atmosphere of color-field abstract of Rothko on clothing. Especially, the ideology of color-field abstract of Rothko of shaping of colors could be expressed and the direction of the development of motives could be presented at the same time by specifically applying color combination method using horizontal division of atypical color-field from the formative characteristics of color-field abstract of Rothko.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.57-58
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• 2006

The effects of lowering ECAP temperature during ECAP process and Post-ECAP annealing on microstructure, texture and mechanical properties of the AZ31 alloys have been investigated in the present study. The as-extruded materials were ECAP processed to 2 passes at 553K prior to subsequent pressing up to 6 passes at 523K or 493K. When this method of lowering ECAP temperature during ECAP was used, the rods could be successfully deformed up to 6 passes without any surface cracking. Grain refinement during ECAP process at 553K might have helped the material to endure further straining at lower deformation temperatures probably by increasing the strain accommodation effect by grain boundary sliding, causing stress relaxation. Texture modification during ECAP has a great influence on the strength of Mg alloys because HCP metals have limited number of slip systems. As slip is most prone to take place on basal planes in Mg at room temperature, the rotation of high fraction of basal planes to the directions favorable for slip as in ECAP decreases the yield stress appreciably. The strength of AZ31 Mg alloys increases with decrease of grain size if the texture is constant though ECAP deformation history is different. A standard positive strength dependence on the grain size for Mg alloys with the similar texture (Fig. 1) supports that the softening of ECAPed Mg alloys (a negative slope) typically observed despite the significant grain refinement is due to the texture modification where the rotation of basal planes occurs towards the orientation for easier slip. It could be predicted that if the original fiber texture is restored after ECAP treatment yielding marked grain refinement, yield stress as high as 500 MPa will be obtained at the grain size of ${\sim}1{\mu}m$. Differential speed rolling (DSR) with a high speed ratio between the upper and lower rolls was applied to alter the microstructure and texture of the AZ31 sheets. Significant grain refinement took place during the rolling owing to introduction of large shear deformation. Grain size as small as $1.4{\mu}m$ could be obtained at 423K after DSR. There was a good correlation between the (0002) pole intensity and tensile elongation. This result indicates that tensile ductility improvement in the asymmetrically rolled AZ31 Mg alloys is closely related to the weakening of basal texture during DSR. Further basal texture weakening occurred during annealing after DSR. According to Hall-Petch relation shown in Fig. 1, the strength of the asymmetrically rolled AZ31 is lower than that of the symmetrically rolled one when compared at the same grain size. This result was attributed to weakening of fiber texture during DSR. The DSRed AZ31, however, shows higher strength than the ECAPed AZ31 where texture has been completely replaced by a new texture associated with high Schmid factors.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.2
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• pp.69-73
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• 2018

Crystal growth of ${\alpha}-Fe_2O_3$ nanosized particles of 80~90 nm in size, which were hydrothermally prepared from 0.03 M $FeCl_3$ solution at $100^{\circ}C$, was investigated in Pb-containing and Pb-free frit. By heating ${\alpha}-Fe_2O_3$ nanosized particles in two frits at $800^{\circ}C$, the average diameter of particles in frits was increased to 200~210 nm and 150~160 nm, respectively, and the crystal growth due to the aggregation and sintering of several ${\alpha}-Fe_2O_3$ particles was observed. Formation ratios of larger particles over 100 nm in diameter were 54 % in Pb-free frit and 85 % in Pb-containing frit. After heating ${\alpha}-Fe_2O_3$ particles in frits at $800^{\circ}C$, 7~9 nm in average diameter of pores were formed in particles. Theses pores were derived from the porous structure of original ${\alpha}-Fe_2O_3$ particles and confined in particles during sintering.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.6
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• pp.731-742
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• 2010

Modeling of rubber for design or analysis often requires confusing or complex work because there are a large number of constitutive models to be considered. Some models have few material constants, while others have many. Researchers have to prepare and fit extensive experimental data with caution and discretion. In this paper, we first compared some typical rubber models in which deformation was carried out by stretching up to around eight times the original size. We conclude that continuum-based models and chain molecular models can be used in the study of the small deformation in most engineering applications, but chain molecular models are preferred in the study of the large deformations in most biomaterial applications. As discrimination problems, Treloar's patch and cylindrical balloon stick are tested theoretically and numerically for studying bifurcation. In the case of Treloar's patch, by using the Kearsley's equation, we show that bifurcation exists for continuum-based models but not for chain molecular models. Both models show bifurcation in the cylindrical balloon stick. Therefore, in the analysis of the bifurcation of rubber showed that its existence also depends on the constitutive model selected.

• Conservation Science in Museum
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• v.16
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• pp.56-81
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• 2015

Ring in the scroll painting is one of the mounting elements which are fixed string and tassel to hang, these differ widely in shape and produce a variety of metals. Most traditional shapes of ring have been lost, because of remount, there are used Japanese style rings in present.Therefore, this study examines to shape, production technique and analyze component traditional style rings of 19 traditional scroll paintings in National Museum of Korea for restoration of original style. Ring has been recorded official names; Wonhwan(Ring), Gukhwadong(Chrysanthemum shaped ornaments), Baemok(Ring-shaped nail) in Uigwe. Result of an optical microscope (Leica, M205A), Wonhwan has two type of production technique; one is cutting and bending a metal rod and other is cast. Baemok is made to forging process after metal rod or plate by casting alloy. Baemok decoration is metal plate cutting shape, and then decorates it with pattern by using kicking line engraving, chasing and so on. Component analysis result from portable X-ray fluorescence found various metals, such as, brass, iron silver-cooper. Brass based on copper and zinc used rings of 17 scroll painting. Baemok of Yun Sidal portrait is used iron and plated with a tin-lead alloy. Yi Seogu portrait is silver-cooper alloy in whole ring.

• Conservation Science in Museum
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• v.16
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• pp.82-95
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• 2015

Old Monk by Yun Duseo is realized to use silver paper which is made of rarity material. This sudy investigates reason why silver, that is easily discoloration in environmental condition, is susceptible in present. The method was the surface treatment materials and the base fiber through direct observation, optical instruments and XRF analysis. Based on these results, reproducing experiment was conducted to research materials in paper of Old Monk and the surface treatment technique. The results, the paper was treated 'Dochim' with a mineral having polygonal crystals for improving smoothness and density. XRF analysis result showed high calcium content, therefore, the paper was not used silver, it guess pulverized shells of abalone or other types of shellfish. Accordingly, the research was narrowed down to shells with shiny, reflective surfaces which at the same time contain high amounts of calcium. A new experiment was conducted using unprocessed abalone shells. Through the reproducing experiment, shellfish has high possibility as used mineral in paper. Notwithstanding, this experiment was unable to precisely reproduce the smoothness and shine of the original paper. Further research may therefore be needed.

• Journal of Conservation Science
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• v.29 no.2
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• pp.127-138
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• 2013

Plastic, widely used as a material for contemporary art, get damaged as directly exposed to temperature, humidity, ultra violet, etc. And it is very quickly damaged in early time, once damaged, it can't recover into original state. But like this characteristics, there is a few advanced research in Korea. So this study deal with a rising value of plastic artifacts in other country, United Kingdom and France, current conservation state, identification and cleaning method. Also 5 types of cleaners(distilled water, ethanol, acetone, eraser) and adhesives(cyanoacrylate, epoxy, acrylic, chloroprene rubber) were evaluated by produced plastics(PVC, PE, PP, PS, PU). As a result of experiment, ethanol and acetone that were previous evaluated in other research performed in other country are the best cleaner. Result of degradation after adhesive, cyanoacrylate and epoxy resin showed better performance and stability. As a basic research, this study is expected that can be used in future researches.