• Journal of the Korean Home Economics Association
• /
• v.37 no.11
• /
• pp.157-165
• /
• 1999

This study was carried out to examine the effect of clothing materials and multi-layered textiles on thermal resistance value. Cotton, polyester, wool, silk, rayon and acetate were selected for the specimens. Thermal resistance value was tested with 2 kinds of methods(thermo labo II and BK type tester). The results were as follows; 1. The effects of clothing materials for thermal resistance value were decreased by adding layers. 2. When the fabrics are measured with multiple layers, the fabric of the lowest thermal resistance value at single layer was showed the highest increasing tendency for all test methods.

• Korean Journal of Metals and Materials
• /
• v.49 no.2
• /
• pp.192-196
• /
• 2011

The multi-layered thin film with an ITO/Ag/ITO structure was produced on PET by using magnetron reactive sputtering method. First, 30 nm of ITO thin film was coated on PET by using normal temperature process. Then 20-52 nm of the Ag thin film was coated. Lastly, 30 nm of ITO thin film was coated on Ag layer. The sample of the 20 nm Ag thin film showed more than 70% transmission and a $2.7{\Omega}/{\Box}$ sheet resistance. When compared to the existing single-layered transparent conducting thin film, multi-layered film was found to be superior with about $5{\Omega}/{\Box}$ less sheet resistance. However, since the Ag layer became thinner, the band gap energy needs to be increased to more than 3.5 eV.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.10
• /
• pp.601-607
• /
• 2016

Piezoelectric thick films of soft $Pb(Zr,Ti)O_3$ (PZT) based commercial material (S55) were fabricated using a conventional tape casting method. Ag-Pd electrodes were printed on the piezoelectric film at room temperature and all 5 layered films with a dimension of $12mm{\times}16mm$ were successfully laminated for a multi-layered piezoelectric ceramic actuator. The laminated specimens were co-fired at $1,100^{\circ}C$ for 1 h. A flat layered and dense microstructure was obtained for the $112{\mu}m$ thick piezoelectric actuator after sintering process. Thereafter, a prototype piezoelectric speaker was fabricated using the multi-layered piezoelectric ceramic actuator which can operate as a bimorph. Its SPL (sound pressure level) characteristic was also evaluated for speaker application. Frequency response revealed that the output SPL with a root mean square voltage of 10 V increased gradually to the highest peak of 87.5 dB for 1.5 kHz and exhibited a relatively stable behavior over the measured frequency range (${\leq}20kHz$) at a distance of 10 cm, implying that the fabricated piezoelectric speaker is potential for speaker applications.

• Journal of Conservation Science
• /
• v.35 no.5
• /
• pp.440-452
• /
• 2019

This research has analyzed SI, the traditional steel, and SIHS(SI + HS), SICS(SI + CS), and SINiS(SI + NiS), the materials that were produced through welding and reprocessing three modern steel- HS, CS, and NiS- that have different carbon content. The purpose of the analyzation was to improve the definition of the multi-layered pattern that appears in the forging process. In observing modified structures on the commissures of three modern steel that have different carbon component to the SI, SINiS produced the most significant multi-layered pattern as well as the excellent welding quality. The excellent welding quality was due to the content of nickel which helped the forge welding process with other materials. There was no significant difference in crystal grain per materials, and SICS showed the highest hardness. At the measurement of EPMA for commissures of the materials, SINiS showed the highest definition of the multi-layered pattern due to the nickel and carbon content. The results above showed that the carbon steel with nickel content is the best material for the most definite multi-layered pattern, expressed from the multi-layered structure which is a characteristic of traditional forge welding technology. It is expected that the result of this research can be utilized as the technical data in further researches regarding the relics excavated from ancient welding process and their multi-layered structure and patterns.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.257-258
• /
• 2007

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.175-180
• /
• 2006

The acoustical properties of multi-layered treatments of materials used in applications, such as automotive liners, generally cannot be directly measured by a one-time test in a standing wave duct. Therefore, we have to consider predicting them by the four-pole transfer matrix method. This method requires performing TCM or TLM for measuring the transfer matrix of each layer and calculating the total transfer matrix of the whole multi-layered material. The final predicted absorption ratios and transmission losses of the multi-layered treatments strongly depend on the measured transfer matrix of each layer. All these functions have been included in a new designed acoustical software.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2005.04a
• /
• pp.137-140
• /
• 2005

Resin transfer molding (RTM) is one of the most popular processes for producing fiber reinforced polymer composites. In the manufacture of complex thick composite structures, analysis on flow front advancement on the resin impregnating the multi-layered fiber preform is helpful for the optimization of the process. In this study, three-dimensional mold filling simulation of RTM is carried out by using CVFEM (Control Volume Finite Element Method). On the assumption of isothermal flow of Newtonian fluid, Darcy’s law and continuity equation are used as governing equations. Different permeability tensors employed in each layer are obtained by experiments. Numerically predicted flow front is compared with experimental one in order to validate the numerical results. Flow simulations are conducted in the two mold geometries, rectangular plate and hollow cylinder. Permeability tensor of each layer preform in Cartesian coordinate system is transformed to cylinder coordinates system so that the flow within the multi-layered preforms of the hollow cylinder can be calculated exactly. Our emphasis is on the three dimensional flow analysis for circular three-dimensional braided preform, which shows outstanding mechanical properties such as high impact strength and toughness compared with other conventional two-dimensional laminar-structured preforms.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.9 no.3
• /
• pp.221-230
• /
• 2007

This research was focused on the changes of layered techniques in Hussein Chalayan's collections. For this purpose, the layered techniques in 134 works from Chalayan's collections, 97S/S to 06S/S, which were obtained from fashion magazines and fashion internet site, were analyzed and classified into 15 groups. Layered techniques in his works apparently expressed his philosophy about deconstruction. Multilayered feeling was given through using various techniques such as one layer clothing which was showed like multi-layered clothing. Others were multi-layer clothing which felt like one layer, breaking the stereotyped line of clothing into atypical construction and using various materials or constructive lines which made the optical feeling like one layer or multi-layer clothing, and so on. These layered techniques in Chalayan's collections were differentiated into several categories, such as techniques which were revealed in every collections, techniques which were differentiated from one another collections, techniques which were continuously showed through three collections for connection with each collection, techniques which were used only for Spring/Summer season, and techniques which were uniquely showed in early collection or recent collections.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.535-536
• /
• 2008

Multi-layered thin films of ZnS/$Na_3AlF_6$/ZnS/Cr were deposited on glass substrate by evaporation process. ZnS and $Na_3AlF_6$ were selected as high and low refractive index material, and additionally Cr was chosen as mid reflective layer respectively. The multi-layered thin films were prepared in terms of different optical thickness and different staking sequence and layers. The optical properties were systematically characterized with different optical thickness of $Na_3AlF_6$ especially $0.25\lambda$ and $0.5\lambda$. In order to expect the experimental result, the simulation program, the Essential Macleod Program(EMP) was adopted. Based on the results taken by spectrophotometer at viewing angle $45^{\circ}$, the ZnS/$Na_3AlF_6$/ZnS/Cr multi-layered thin film shows purple colour range in $0.25\lambda$， bluish green in $0.5\lambda$, red purple in $0.75\lambda$, and purple in $1.0\lambda$ respectively.

• Composites Research
• /
• v.22 no.3
• /
• pp.66-73
• /
• 2009

Total thickness, areal density and mass moment of inertia of materials are important material factors for structural characteristics. In this work, a material-structural optimization was performed up to the maximum ballistic limit of multi-layered composite structures under high impact velocity followed by the investigation of the influence of these factors on an impact absorption performance. A unified model combined with Florence's and Awerbuch-Bonder's models was used in optimizing the multi-layered composite structure consisting of CMC, rubber, aluminum and Al-foam. Total thickness, areal density and mass moment of inertia were used for the optimization constraint. As shown in the results, the ballistic limit determined from a newly developed unified model was closely similar to the finite clement analysis. Additionally, the ballistic limit and impact absorption energy obtained by the optimized structure were improved approximately 16.8% and 26.7%, respectively comparing with a not optimized multi-layered structure.