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To develop more effective optoelectronic devices with a transparent heater, it is necessary to investigate the droplet evaporation characteristics and wettability control on the heater surface. An optically transparent and hydrophobic amorphous fluoropolymer, Cytop, is spin-coated onto a nano-thick copper (Cu) micromesh-based transparent conductor to evaluate its performance for a high-durable transparent heater (a transmittance of 81.6% at 550 nm, a sheet resistance of 5 Ω sq–1). As the result, the thermal and chemical stabilities of the pure Cu micromesh-based transparent heater with the ∼80 nm thick Cytop layer improve without performance degradation. The evaporation time of water droplets on the surface of the hydrophobic transparent heater is noticeably delayed (about 60–130%) because the average evaporation flux of the droplet on the surface of the hydrophobic transparent heater is lower than those on the hydrophilic heater surfaces. In addition, unlike when the heater surface is hydrophilic, there is no coffee-ring effect when the heater surface is hydrophobic due to the recirculating Marangoni flow within the droplet. Further, the hydrophobic transparent heater surface exhibits excellent icephobic and antifrost properties. The results will be helpful for the further development of practical transparent heaters including self-cleaning smart windows, transparent actuators, transparent chemical and biological sensors, and transparent heating sources.

최근 몇 년간 우리 사회는 정신질환자들에 의한 살인, 방화 등 강력사건이 증가하고 있어 많은 이들에게 불안감을 주고 있다. 정신질환자들의 범죄는 뚜렷한 동기가 없는 소위 ‘묻지마범죄’의 형태를 띠고 있다. 올해 진주에서 발생했던 방화 살인사건도 뚜렷한 동기가 없이 불특정 다수인을 상대로 범한 강력사건이다. 따라서 필자는 범죄를 다루는 일선경찰관으로서 최근 몇 년 사이 이들 사건을 포함하여 범죄자들이 스스로 정신질환자라고 주장하는 범죄가 계속 증가하고 있는 것에 주목하여 관찰한 결과, 정신질환자가 난동행위를 하여 부모 등이 112신고를 하여 현장에 출동하여 현장에서 처리하면서 우리나라의 정신건강복지법이 문제가 있다는 것을 알게 되었다. 즉, 개정 정신건강복지법이 너무 대상자의 인권보호에만 치중한 결과 공공의 안전 부분이 위협을 받고 있다는 것이다. 그래서 본 논문에서는 묻지마범죄의 특성, 정신질환자들의 범죄통계, 정신질환자들의 입원현황을 알아보고, 최근 정신질환자들의 범죄 중 조현병환자가 많은 것을 감안하여 조현병에 대하여 살펴 본 후, 묻지마범죄에 대한 대책의 일환으로서 정신건강복지법 중 입원제도를 중심으로 하여 문제점과 개선방안을 제시하였다. 즉, 첫째, 자의입원의 경우에는 퇴원 등을 신청한 경우에도 정신건강심의위원회의 심의를 거쳐 퇴원여부를 결정하고, 정신의료기관등의 장은 자의입원 등을 한 사람에 대하여 입원 등을 한 날부터 2개월마다 퇴원 등을 할 의사가 있는지를 확인하도록 하고 있는 규정의 폐지를 주장하였다. 둘째, 동의입원 제도의 규정의 삭제를 주장하였다. 셋째 보호자에 의한 입원의 경우에 입원요건을 완화하고자 정신의료기관등의 장은 정신건강의학과전문의 진단 결과 정신질환자가 법소정의 모든 요건을 충족한 경우로서 입원 등이 필요하다고 진단한 경우 그 증상의 정확한 진단을 위하여 2주의 범위에서 기간을 정하여 입원하게 할 수 있다는 규정을 소정의 요건 중 하나라도 충족하면 입원을 가능하게 하고자 주장하였다. 넷째, 행정입원의 경우에는 정신질환자로 의심되는 자가 주민들을 불안하게 하는 반복신고가 경찰에 접수되는 경우에 의무적으로 정신건강센터에 통보하여 행정입원 여부를 결정하여야 한다’ 라는 법규정의 신설과 안전한 호송을 위하여 호송주체를 119구급대원 및 경찰관으로 할 것을 주장하였다. 다섯째 응급입원의 경우에는 동의의 주체인 경찰관의 경우에 정신건강의료부분에 대한 의무교육을 받을 것과 면책규정 등을 제안하였다.

Graphene oxide (GO) is one of the interesting ink materials owing to its fascinating properties, such as high dissolubility in water and high controllable electric properties. For versatile printing application, the viscosity of GO colloids should be controlled in order to meet the specific process requirements. Here, we report on the relatively rapid fabrication of viscosity-increased GO (VIGO) colloids mixed with electrophoretically deposited GO sheets (EPD-GO). As the GO colloid concentration, applied voltage, and deposition time increase, the viscosity of the GO colloids becomes high. The reason for the improved viscosity of GO colloids is because EPD-GO has parallel stacked GO sheets. The GO and VIGO colloids are compared and characterized using various chemical and structural analyzers. Consequently, our simple and fast method for the fabrication of GO colloids with enhanced viscosity can be used for producing inks for flexible and printed electronics.

Thickness-controlled transparent conducting films (TCFs) were fabricated by transfer printing a 100 nm thick Cu micromesh structure onto poly(vinyl alcohol) (PVA) substrates of different thicknesses (~ 50, ~ 80, and ~ 120 μm) to develop a lightweight transparent wearable heater with short response time. The Cu mesh-based TCF fabricated on a ~ 50 µm thick PVA substrate exhibited excellent optical and electrical properties with a light transmittance of 86.7% at 550 nm, sheet resistance of ~ 10.8 Ω/sq, and figure-of-merit of approximately 236, which are comparable to commercial indium tin oxide film-based transparent conductors. The remarkable flexibility of the Cu mesh-based TCF was demonstrated through cyclic mechanical bending tests. In addition, the Cu mesh-based TCF with ~ 50 μm thick PVA substrate demonstrated a fast Joule heating performance with a thermal response time of ~ 18.0 s and a ramping rate of ~ 3.0 ℃/s under a driving voltage of 2.5 V. Lastly, the reliable response and recovery characteristics of the Cu mesh/PVA film-based transparent heater were confirmed through the cyclic power test. We believe that the results of this study is useful in the development of flexible transparent heaters, including lightweight deicing/defogging films, wearable sensors/actuators, and medical thermotherapy pads.

최근 데이트폭력 ‘연인 간 폭력’이 자신의 연인을 대상으로 살인, 강간 등 강력 사건으로 발생되면서 심각한 국가, 사회문제가 되고 있다. 또한, 경찰청 자료를 보아도 데이트폭력은 계속 증가하고 있다. 문제는 지금까지 데이트폭력 ‘연인 간폭력’을 단순한 남녀간의 사랑싸움으로 치부하여 온 것이 우리 사회의 현실이었다. 데이트폭력은 일선 치안현장에서 보면 서로 연인 간이라는 인적 특수성이 존재한다는 특성이 있고, 집착과 반복성이라는 특성이 있다. 또한, 데이트폭력은 자신의 연인을 상대로 하여 단순 폭행을 넘어서 정신적, 경제적, 통제력을 행사하는 다양한 폭력 유형들이 복합적으로 나타나고, 더구나 인적 특수성으로 인하여 피해자 보호가 제대로 되지 않으면서 피해자에게 신체적 침해 외에도 심각한 정신적 후유증을 초래하게 된다. 특히, 최근 결혼을 하지 않는 비혼화의 증가와 이로 인한 1인 가구의 증가로 인해 연인 간 폭력의 문제는 앞으로도 계속 증가할 것으로 생각된다. 이에 데이트폭력에 대한 방지와 피해자의 보호를 강화하기 위한 대책으로서 데이트폭력에 대한 반의사불벌죄 적용 배제, 데이트폭력전과 공개제도 신설, 데이트폭력범죄 가해자에 대한 ‘접근금지등’ 임시조치 규정신설, 상습 데이트폭력사범에 대한 치료적 사법제도의 적극 활용, 데이트폭력범죄 피해자에 대한 심리치료 등의 활성화를 주장하였다.

In this study, we use density functional theory (DFT) calculations to investigate the effect of moisture on the performance of three types of nanofiber (NF)-based air-filter media prepared by electrospinning polyvinyl alcohol, polyvinylidene fluoride, and polyacrylonitrile (PAN). Based on the DFT calculations of the intermolecular interactions between the NF-based filter media and water molecules, the PAN-NF filter is expected to exhibit the best performance in the wet state. Experiment studies also successfully demonstrate that the PAN-NF filter medium has better performance in the filtration of particulate matter (PM) than a commercial semi-high efficiency particulate air filter under wet conditions, and these results are in good agreement with the DFT calculation. The PAN-NF filter shows better performance because of its hydrophilic nature and the relatively low thickness the filter medium that allowed fast recovery of its PM-filtration performance.

In this paper, we propose a new strategy to improve the performance of nanoporous silicon (np-Si) layer-based optical gas sensors. For this, we fabricated the np-Si layer on a p+-type silicon substrate and modified the surface wettability of the np-Si layer with oxygen (O2) plasma treatment. We then compared the changes in the reflectance spectra of the O2 plasma-treated np-Si layer that had been exposed to various organic vapors with that of the untreated np-Si layer. The results by measuring the contact angle on the surface confirmed that the surface of the O2 plasma-treated np-Si layer was hydrophilic. During the exposure to the organic vapors, there was a reversible red-shift phenomenon in the reflectance spectrum. This study confirmed that the red-shift can be attributed to the changes in the refractive index induced by the capillary condensation of the organic vapor within the nanopores of the np-Si layer. The changes in the reflectance spectra of the hydrophilic-treated np-Si layer were more noticeable than those in the untreated np-Si layer. These experimental results indicate that hydrophilic surface treatment can improve the selectivity and sensitivity of np-Si layer-based gas sensors.

Due to the increasing use of polypropylene-based nonwoven dust masks and air filters, environmental problems that occur due to the plastic pollution resulting from the disposal of these materials have also increased. Hence, an eco-friendly air filter based on PVA nanofibers (NFs) was fabricated by electrospinning on a nonwoven fabric, and its performance was evaluated as a filter capable of blocking or capturing particulate matter. The quality factor of the optimized PVA NF-based air filter was found to be 0.010606 Pa−1, which is lower than that of a HEPA filter (0.015394 Pa−1), but higher than that of a cabin air filter (0.010517 Pa−1) and a dust mask (0.009102 Pa−1). The contamination level of the PVA NF-based filter was analyzed by optical and structural analyses of the filter surface. Finally, the filter was soaked in water to selectively remove the contaminated PVA NF layer, and the remaining nonwoven fabric was able to be reused to make the filter.

To develop high-performance de- or anti-frosting/icing devices based on transparent heaters, it is necessary to study the evaporation-rate control of droplets on heater surfaces. However, almost no research has been done on the evaporation-rate control of liquid droplets on transparent heaters. In this study, we investigate the evaporation characteristics of water droplets on transparent heater surfaces and determine that they depend upon the surface wettability, by modifying which, the complete evaporation time can be controlled. In addition, we study the defrosting and deicing performances through the surface wettability, by placing the flexible transparent heater on a webcam. The obtained results can be used as fundamental data for the transparent defrosting and deicing systems of closed-circuit television (CCTV) camera lenses, smart windows, vehicle backup cameras, aircraft windows, and sensor applications.

Nanopatterns of functional materials have successfully led innovations in a wide range of fields, but further exploration of their full potential has often been limited because of complex and cost-inefficient patterning processes. We here propose an additive nanopatterning process of functional materials from solution route using selective wetting phenomenon. The proposed process can produce nanopatterns as narrow as 150 nm with high yield over large area at ultrahigh process speed, that is, the speed of solution dragging, of up to ca. 4.6 m·min–1. The process is highly versatile that it can utilize a wide range of solution materials, control vertical structures including pattern thickness and multistacks, and produce nanopatterns on various substrates with emerging form factors such as foldability and disposability. The solution patterning in nanoscale by selective wetting is enabled by corresponding surface energy patterns in high contrast that are achieved by one-step imprinting onto hydrophobic/hydrop...

Particulate matter (PM) pollution is serious human health issue. Various filter technologies have been developed to improve the air filtration efficiency. Recently, nanofibrous membrane filters have received much attention due to its outstanding transparency and high efficiency for PM ≤ 2.5 μm (PM2.5) capture/removal compared to conventional micro-structured filters. Although these filters provide high-efficiency PM2.5 capture, obtaining strong PM adhesion via surface engineering remains a challenge. In this study, we demonstrate a high efficiency PM2.5 capture air-filter by electrospun polyacrylonitrile nanofibers (EPNFs). The surface of the EPNFs was modified by oxygen plasma treatment for generating functional groups such as CONH2, COOH and COOR. The EPNFs were utilized as air filter in hand-made PM removal system which is consisted of DC power supply, PM source, PM sensor and PM removal test chamber. The test result showed high air flow and effective air filtration (PM2.5 removal efficiency: 94.02%, pressure drop: 18 Pa, Time to reach the PM level recommended by the World Health Organization (TWHO PM2.5): 15 min, quality factor: 0.1564 Pa−1) compared to commercial filters. The intermolecular interaction between the plasma-treated EPNFs (PEPNFs) and PMs was investigated by density functional theory (DFT) calculations. The PEPNF filter showed high long-term reproducibility in a cycle test with a high PM concentration (over 2,000 μg m−3). The filter was applied as a car interior air purifier using a cigar jack as a power supply, ca. 16 min was required to reach the PM level recommended by the World Health Organization (

The objectives of this study were to determine the effects of 1) the extraction temperature (65, 75, 85, and 95°C) of chicken feet gelatin (CFG) and 2) CFG extracted at different temperatures and wheat fiber (WF) with different particle sizes (80, 250, and 500 μm) on the physicochemical properties of the resultant gels. Raw chicken feet (CF) were swelled by treatment of an acidic solution [i.e., 0.1 N HCl (pH 2)]. The CFG was extracted from the swelled CF at different temperatures. Samples of 4% CFG or a mixture of 3% CFG and 3% WF were prepared using distilled water at 42 ± 1°C and then cooled to form gels. The physicochemical properties of the prepared CFG or the gel with CFG and WF were then investigated. The results indicate that the extraction yield, protein content, and L* values for the CFG samples significantly increased as the extraction temperature increased, whereas the viscosity, melting point, and a* values decreased. For the gel with CFG and WF, the gel strength, melting point, viscosity, and L* and b* values were significantly affected (P 0.05) by the extraction temperature of CFG, but they partially were not affected (P 0.05) by the particle size of WF. The gel with WF and extracted CFG at 65°C had the highest (P 0.05) gel strength, melting point, viscosity, and a* values. In conclusion, CFG or the gel with CFG and WF could be utilized to prepare gelatins or gel with different physicochemical properties by controlling the extraction temperature or particle size of WF, depending on the specific application. Moreover, with its distinct physicochemical properties, the gel with CFG and WF could possibly be used as a non-meat ingredient for fat replacement.

Nanoporous-silicon (np-Si) flakes were prepared using a combination of an electrochemical etching process and an ultra-sonication treatment and the electrochemical properties were studied as an anode active material for rechargeable lithium-ion batteries (LIBs). This fabrication method is a simple, reproducible, and cost effective way to make high-performance Si-based anode active materials in LIBs. The anode based on np-Si flakes exhibited a higher performances (lower capacity fade rate, stability and excellent rate capability at high C-rate) than the anode based on Si nanowires. The excellent performance of the np-Si flake anode was attributed to the hollowness (nanoporous structure) of the anode active material, which allowed it to accommodate a large volume change during cycling.

To develop more effective defogging/deicing (or anti-fogging/anti-icing) devices based on transparent heaters, it is necessary to investigate droplet evaporation on the heater surfaces. However, the characteristics of this evaporation process have not yet been reported. Here, we present the evaporation characteristics of water droplets and their evaporation rates on various transparent heaters (based on metal mesh, indium tin oxide thin film, and Ag nanowires) with various surface wettabilities. We determined that the evaporation characteristics of a droplet on the surface of a transparent heater depend on the surface wettability and that the evaporation rate can be controlled by modifying the surface wettability.

Advances in flexible optoelectronic devices have led to increasing need for developing high performance, low cost, and flexible transparent conducting electrodes. Copper-based electrodes have been unattainable due to the relatively thermal instability and poor oxidation resistance. Herein, we present oxidation-resistive CuNi nanomesh electrodes that exhibit a low sheet resistance of ∼7.5 Ω/□ and a high optical transmittance of ∼81% at 550 nm. Further, high long-term stability against the effects of oxidation, heat, and chemicals is exhibited by the CuNi nanomesh, in comparison with the behavior of a pure Cu nanomesh sample.

This study presents a hybrid fabrication process for LED matrix on flexible multilayer printed circuit boards (PCBs). To prepare for the flexible PCB, a roll-to-roll screen printing process was developed to create a core circuit board by printing on both sides of the flexible substrate. From the core PCB, the lamination and etching processes are then used to form four layers in total. By using the proposed method, we successfully implemented the passive LED matrix display. This approach could be used for other applications that require flexible and multilayer circuits.

In this study, the authors report for the first time a wafer-scale method for fabricating vertical-aligned silicon nanotubes (SiNTs) on a silicon substrate using a combination of nanoimprint lithography (NIL) and metal-assisted chemical etching (MaCE) processes. The structural properties and adhesion strength characteristics of the prepared SiNTs are investigated via field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) analysis, and adhesion test. And, the authors successfully demonstrate the feasibility of using the fabricated SiNTs in a Li-ion battery (LIB) anode, and their potential to enhance LIB technologies.

Modern energy needs and the pressing issue of environmental sustainability have driven many research groups to focus on energy-generation devices made from novel nanomaterials. We have prepared platinum nanoparticle-decorated silicon nanowire/carbon core&ndash, shell nanomaterials (SiNW/C@Pt). The processing steps are relatively simple, including wet chemical etching to form the silicon nanowires (SiNWs), chemical vapor deposition to form the carbon shell, and drop-casting and thermal treatment to embed platinum nanoparticles (Pt NPs). This nanomaterial was then tested as the counter electrode (CE) in dye-sensitized solar cells (DSSCs). SiNW/C@Pt shows potential as a good electrocatalyst based on material characterization data from Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy shows that the surface reactivity of the SiNW/C is increased by the decoration of Pt NPs. These data also show that the carbon shell included both graphitic (sp 2 hybridization) and defective (sp 3 hybridization) phases of carbon. We achieved the minimum charge-transfer resistance of 0.025 Ω &middot, cm 2 and the maximum efficiency of 9.46% with a symmetric dummy cell and DSSC device fabricated from the SiNW/C@Pt CEs, respectively.

In order to improve their performance for various applications, a facile method for the wafer-scale fabrication of micro/nano-patterned vertical silicon (Si) structures such as silicon nanowires (SiNWs), silicon nanorods (SiNRs), and porous silicon (p-Si) was developed. The method is based on the combination of lithography techniques (photolithography, thermal nano-imprint lithography, nanosphere lithography) and wet chemical etching (electro-chemical etching, metal-assisted chemical etching) processes. Micro-patterned p-Si with various pore diameters from 30 nm to 1.2 um were fabricated via electro-chemical etching. Micro/nano-patterned Si microstructures, nanorods, and nanowires were also successfully fabricated by changing the thickness of the metal layer of 5 nm or 20 nm in the metal-assisted chemical etching process. This study also investigated the effect of the etching time and patterning on the etched SiNWs length. This method provides advantages of simplicity, speed, large-scale production, easy size and shape manipulation, and low cost.

The fabrication of uniformly interconnected cupronickel (CuNi) micromesh films on glass and polymer substrates with seamless junctions has been achieved using a simple transfer printing method. When used as a transparent heater, these CuNi micromesh films exhibited an effective and rapid heating performance at low input voltages (below DC 9 V) that can be attributed to the creation of a high quality network over the whole surface area that offers a relatively high transmittance, strong adhesion to its substrate and good mechanical flexibility. A high thermal stability and reliability was also observed relative to a pure Cu micromesh film. Transparent heaters based on CuNi micromesh are therefore considered suitable for providing anti-fogging or de-icing in optics and optoelectronic devices, as well as for wearable heating systems.

We designed and fabricated a gold (Au)-coated silicon nanowires/graphene (Au–SiNWs/G) hybrid composite as a polymer binder-free anode for rechargeable lithium-ion batteries (LIBs). A large amount of SiNWs for LIB anode materials can be prepared by metal-assisted chemical etching (MaCE) process. The Au–SiNWs/G composite film on current collector was obtained by vacuum filtration using an anodic aluminum oxide (AAO) membrane and hot pressing method. Our experimental results show that the Au–SiNWs/G composite has a stable reversible capacity of about 1520 mA h/g which was maintained for 20 cycles. The Au–SiNWs/G composite anode showed much better cycling performance than SiNWs/polyvinylidene fluoride (PVDF)/Super-P, SiNWs/G composite, and pure SiNWs anodes. The improved electrochemical properties of the Au–SiNWs/G composite anode material is mainly ascribed to the composite׳s porous network structure.

Uniform metal nanomesh structures are promising candidates that may replace of indium-tin oxide (ITO) in transparent conducting electrodes (TCEs). However, the durability of the uniform metal mesh has not yet been studied. For this reason, a comparative analysis of the durability of TCEs based on pure Ag and AgNi nanomesh, which are fabricated by using simple transfer printing, is performed. The AgNi nanomesh shows high long-term stability to oxidation, heat, and chemicals compared with that of pure Ag nanomesh. This is because of nickel in the AgNi nanomesh. Furthermore, the AgNi nanomesh shows strong adhesion to a transparent substrate and good stability after repeated bending.

The objective of this study was to evaluate the effects of soy sauce on the physicochemical and textural properties of tumbled chicken breasts. Chicken breasts marinated with distilled water (Con), 4% NaCl solution, 4% NaCl and lactic acid solution (pH 4.9), and soy sauce solution (4% salt concentration and pH 4.9) were vacuum tumbled at 3°C for 60 min. The chicken breast marinated with soy sauce solution showed lower lightness and higher redness and yellowness due to the color of the soy sauce. The acidic marinades led to a decrease in pH value of tumbled chicken breast. The acidic marinades increased collagen solubility of sample compared with 4% NaCl solution, resulting in decreased shear force. Water-holding capacity, marination and cooking yields, and solubility of myofibrillar proteins were mainly affected by the presence of salt in the marinade, rather than by pH alternation. Our results suggested that soy sauce marination can improve the tenderness of tumbled chicken breast.

We fabricated single-layer porous silicon (PSi) on a p +-type silicon wafer and investigated its reflectance spectrum on exposure to different concentrations of various organic vapors. When the PSi sample was exposed to methanol, acetone, ethanol, and isopropanol vapors, the reflectance spectrum promptly shifted toward longer wavelengths by about 1.5, 4.5, 7.0, and 9.0 nm, respectively. The PSi sample showed excellent sensing ability under different concentrations and types of organic vapors. In addition, a slight hysteresis of the red-shift was observed during repeated exposure to an organic vapor at different concentrations. After the organic vapors had been removed, the reflectance spectrum promptly returned to its original state.

In this study, we propose the guideline with strategic model for new product development. To establish the guideline, 1) we classify several types of successful surveyed cases that achieved open innovation through applying crowdsourcing into new product development environment, 2) draw case maps using two or three axis with characteristics such as: step of product development process, crowdsourcing frequency, and product type of each case, 3) define the type of applying crowdsourcing into new product development environment based on case analysis results, and tabulate a crowdsourcing type based on the defined crowdsourcing type, 4) finally, suggest the guideline with multiple points of view which embrace type of crowd, community management, participation method, knowledge adoption method, and reward policy. Using the suggested guideline will help a company to design and establish open innovation in new business model related to product development area.

Silicon nanowires (SiNWs) for use as lithium-ion battery (LIB) anode materials have been studied for their one-dimensional (1D) properties and ability to accommodate large volume changes and avoid rapid capacity fading during cycling. Although the vertical transfer of SiNWs from their original substrate onto a conducting electrode is very important, to date, there has been no report of a direct integration method without polymer binders. Here, we propose for the first time a vertical transfer method for SiNWs grown on a Si substrate directly to the current-collecting electrode without using a polymer adhesive for the use as a binder-free LIB anode. The vertical SiNWs produced using a low-cost wafer-scale metal-assisted chemical etching (MaCE) process have been successfully transferred directly to a copper electrode coated with a thin Ag layer by using a simple hot pressing method. When evaluated as an LIB anode without using conventional polymeric binder and a conducting additive, the transferred vertically aligned SiNWs showed a high specific capacity (≈2150 mAh g(-1) ) and excellent rate performance. It is believed that the anode-manufacturing process is simple and fast, thus enabling a large-scale production that is of low-cost, broadly applicable, and provides new avenues for the rational engineering of Si-based electrode materials with enhanced power density and conductivity.

We present a novel method of fabricating superhydrophobic and superoleophobic surfaces with nanoscale reentrant curvature by nanotransfer molding and controlled wet etching of the facile undercut. This method produces completely ordered re-entrant nanostructures and prevents capillary-induced bundling effects. The mushroom-like, re-entrant, overhanging structure demonstrates superhydrophobic and superoleophobic characteristics, as tested by water droplet bouncing and contact angle measurements, and has high transparency on a flexible substrate. Widespread use as self-cleaning surfaces is expected in the near future.

The objectives of this study were to evaluate effects of rigor state, thawing temperature, and processing on the physicochemical properties of intact frozen duck breast muscle and homogenates prepared with the frozen-thawed muscles. Prerigor breast muscle was frozen at −25°C and thawed at 4 and 15°C, and the physicochemical properties of duck breast frozen prerigor compared with those in frozen postrigor and 4°C chilled postrigor muscles. The homogenates prepared with duck breast frozen prerigor showed similar physicochemical properties as the frozen-thawed postrigor muscle homogenate. The thawing temperature did not affect the physicochemical properties of homogenates prepared with duck breast muscle frozen prerigor. Also, no significant differences (P > 0.05) in the ultimate pH value and color parameters were observed among the frozen-thawed treatments despite the differences in rigor state and thawing temperature. However, a higher thawing temperature of the intact frozen prerigor muscle resulted in an increase in thawing loss and shear force due to excessive muscle shortening. In this study, the intact duck breast that has undergone thaw-rigor showed main problems associated with thaw-rigor, such as higher thawing loss and shear force, regardless of thawing temperature. However, the processing (grinding and salting) decreased the difference in physicochemical properties due to rigor state before freezing and thawing temperature. Therefore, the frozen-thawed duck breast muscle used to manufacture ground-type meat product may be frozen before rigor onset.

Youngju multipurpose dam is planned to minimizing the damage by flood and obtaining the water for industrial use in Nakdong river region. Faults in rock mass have strong influences on the behaviors of dam structure. Thus, it is very important to analyse for the characteristics of fault rocks in dam design. However, due to the limitation of geotechnical investigation in design stages, engineers have to carry out the additional geological survey including directional boring to find the distribution of faults and the engineering properties of faults for stability of dam. Especially, the selection of location of dam and type of dam considering fault zone must be analyzed through various experimental and numerical analysis. In this study, various geological survey and field tests were carried out to analyse the characteristics of the large fault zone through the complex dam is designed in foundation region. Also, the distribution of structural geology, the shape of faults and the mechanical properties of fault rock were studied for the reasonable design of the location and type of dam for long-term stability of the complex dam.

We present a recent experimental study on the application of nanoporous silicon (np-Si) to an optical vapor sensor. We fabricated the micro-system based on a glass-nanoporous silicon layer on a p(+)-type silicon wafer. To check the selectivity and sensitivity of the np-Si layer to organic vapors, we prepared three types of np-Si layer samples--a single layer, distributed Bragg reflector (DBR) layer, and microcavity layer--and investigated its reflectance spectra upon exposure to different concentrations of various organic vapors. When the np-Si layer samples were exposed to the organic vapors, a red-shift occurred in the reflectance spectrum, and we determined that this red-shift can be attributed to the changes in the refractive index induced by the capillary condensation of the organic vapor within the pores of the np-Si layer. The np-Si layer samples showed excellent sensing ability to different types and concentrations of organic vapors. After removing the organic vapors, the reflectance spectrum immediately returned to its original state.

We investigated the critical conditions to realize reliable and nano-engineered templates for surface-plasmon enhanced Raman scattering (SERS). Ultra-sensitive SERSs of thymine oligonucleotides were successfully realized on the template of Au nanoparticle arrays which were prepared by the combination of electron-beam lithography and post-chemical modification techniques. Drastic enhancement of Raman signal from the thymine oligonucleotides was only observed on the optimized templates, where the tuning of the plasmon resonance condition and the formation of the hot spots were both critical. Our results suggest that the artificial generation of reproducible and controlled hot spots can be achieved by our approach.

We report a molecular sensing method based on changes in the electrical conductance of lithographically defined gold nanoparticle (NP) arrays immersed in an analyte solution. As the closely spaced NPs are enlarged due to the analyte-mediated deposition of gold ions onto their surfaces, the conductance increases steeply near the critical time (tc) at which conducting pathways begin to form in the NP arrays. tc decreases with increasing analyte concentration in the solution. The temperature dependence of the conductance of the modified NP arrays confirms the good electrical contacts established between the newly formed nanoclusters on the NP surfaces. Our results demonstrate that the electrical conductance through metal NP arrays can be employed as a sensitive and reliable analytical signal for NP-based sensors, which do not require any post-processing for the formation of electrical contacts between the NPs.

In this study, we successfully demonstrated the rapid, sensitive, and reversible sensing of organic vapor using a distributed Bragg reflector (DBR) porous silicon (PS) layer. We fabricated the DBR PS layer on a p+-type silicon substrate and investigated its reflectance spectra before, during, and after exposure to the different concentrations of various organic vapors. When the DBR PS layer sample was exposed to methanol, acetone, ethanol, and isopropanol vapors, the maximum reflectance peak promptly shifted toward longer wavelengths by about 4.5, 23.2, 26.0, and 38.2 nm, respectively. We determined that the red-shift in the reflectance spectrum could be attributed to the changes in the refractive index induced by the capillary condensation of the organic vapor within the pores of the DBR PS layer. The DBR PS layer showed excellent sensing ability under the different concentrations and types of organic vapors. In addition, a slight hysteresis of the red-shift was observed during repeated exposure to organic vapors at different concentrations. After removing the organic vapors, the reflectance spectrum promptly returned to its original state.

The objective of this study is to evaluate the feasibility of porous silicon (PS) layer as a vapor sensor. We prepared three types of PS layer samples – a single layer, distributed Bragg reflector (DBR) layer, and microcavity layer – and examined their reflectance spectra before, during, and after exposure to different concentrations of various organic vapors. When the PS layer samples were exposed to the organic vapors, their reflectance spectra promptly shifted toward longer wavelengths. We determined that this redshift in the reflectance spectra could be attributed to the changes in the refractive index induced by the capillary condensation of organic vapors in the pores of the PS layers. The PS layers showed excellent sensing ability under different concentrations and types of organic vapors. Once the organic vapors were removed, the reflectance spectra of the PS layer samples promptly returned to their original states. In this study, we successfully demonstrated the rapid, sensitive, and reversible sensing of organic vapors using different PS layers.

We fabricated a porous silicon multilayer and investigated its reflectance spectra before, during, and after exposure to various organic vapors. During exposure of the porous silicon multilayer to isopropanol, ethanol, methanol, and acetone vapors, the reflectance peak shifted toward longer wavelengths by about 5, 12, 26, and 39 nm, respectively. The shift of the reflectance peak arises from refractive index changes induced by capillary condensation of the organic vapor in the pores of the porous silicon multilayer. In addition, we observed that the shift value of the reflectance peak increased with increasing organic solvent concentration in the organic solvent-water mixture. After removing the organic vapor, the reflectance spectrum returned completely to its original state.

An advanced model for assessing life cycle cost of the facility containing several subdivisions has been proposed with systems engineering approach. This model evaluates the maintenance cost in the sphere of the safety as well as in that of its functionality. The proposed approach has been shown to be more reasonable and practical than existing models. The serviceability and reasonability have been proved through evaluating life cycle cost of the reservoir which is a representative agricultural facility. In addition, the proposed method is helpful to make a maintenance strategy using the survival probability in the point of safety and functionality.

There are many agricultural facilities (46.7%) that have been over 30 years in the Republic of Korea (the ratio of reservoirs built before 1945 is 53%, from 1946 to 1971 is 35%). In the case of reservoirs which do most important functions among these facilities, only 3,000 reservoirs are managed by Korea Rural Community & Agriculture Corporation (KRC) and the other 15,000 reservoirs are managed by local authorities (City and Gun). But, 15,000 reservoirs included in City. Gun have been built in more wide area than KRC and the reservoir management system has not been operated well because of shortage of budget and manpower of the local authorities. Particularly, the abnormal weather happened during every summer season recently has ruined a lot of rural community facilities. So flood control function have been more important than irrigation function in agricultural reservoir system and it may be required to introduce new safe, management and maintenance techniques in City Gun reservoirs. So we investigated landscapes and deteriorations of agricultural reservoirs managed by local small governments for revealing not only present usage but also future value. Survey shows that there are no structural managements except typical hydrological reportings and the deterioration of small darn is very serious. There are needs for more systematic management system and equipment methods. Therefore, this study may suggest that reservoir (that takes charge of the greatest deal of weight in all agricultural facilities) must be considered as new concept of the usage and the unification. On the other hand, reservoir must be also developed as amenity resources, natural circumstances and district values.

We have fabricated an in-plane-gate (IPG) single-electron transistor (SET) on an AlGaAs/GaAs wafer and characterized it by measuring a transmitted signal from the transmission-type radio-frequency SET (RF-SET) electrometer system consisting of a resonant tank (LC) circuit and a SET. By measuring the frequency characteristics, we estimate the resonance frequency of the system to be 480 MHz at temperature T=4.2 K. We find that, driving the SET at this frequency, the transmitted signal depends on the gate voltage, and successfully demonstrates the measuring operation. However, the difference between the transmitted signals at the on- and off-gate voltages of the SET was measured to be 0.15 dB, which is relatively small, and it is necessary to optimize the electrical environment of the system by improving the signal-to-noise ratio.

In recent years, inorganic/organic hybrid solar cell concept has received growing attention for alternative energy solution because of the potential for facile and low-cost fabrication and high efficiency. Here, we report highly efficient hybrid solar cells based on silicon nanowires (SiNWs) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) using transfer-imprinted metal mesh front electrodes. Such a structure increases the optical absorption and shortens the carrier transport distance, thus, it greatly increases the charge carrier collection efficiency. Compared with hybrid cells formed using indium tin oxide (ITO) electrodes, we find an increase in power conversion efficiency from 5.95% to 13.2%, which is attributed to improvements in both the electrical and optical properties of the Au mesh electrode. Our fabrication strategy for metal mesh electrode is suitable for the large-scale fabrication of flexible transparent electrodes, paving the way towards low-cost, high-efficiency, flexible solar cells.

The vertical integration of 1D nanostructures onto the 2D substrates has the potential to offer significant performance gains to flexible electronic devices due to high integration density, large surface area, and improved light absorption and trapping. A simple, rapid, and low temperature transfer bonding method has been developed for this purpose. Ultrasonic vibration is used to achieve a low temperature bonding within a few seconds, resulting in a polymer-matrix-free, electrically conducting vertical assembly of silicon nanowires (SiNWs) with a graphene/PET substrate. The microscopic structure, and mechanical and electrical characteristics of the interface between the transferred SiNW array and graphene layer are subsequently investigated, revealing that this creates a mechanically robust and electrically Ohmic contact. This newly developed ultrasonic transfer bonding technique is also found to be readily adaptable for diverse substrates of both metal and polymer. It is therefore considered as a valuable technique for integrating 1D vertical nanostructures onto the 2D flexible substrates for flexible photovoltaics, energy storage, and water splitting systems.

To use the porous silicon as gas sensors, we made the MOPS structure from the porous silicon with Al evaporation and investigated the sensing characteristic of ethanol. When the MOPS structure is in contact with ethanol gas, the maximum peak of PL changes and it return to original intensity without contact. The MOPS structure had response time 0.78s and recovery time 4.13s when it is in contact with ethanol, which satisfied the required sensor standards. Further complimentary researches, however, are required to investigate the contact mechanism between MOPS structure and ethanol and to solve the surface contamination problem.

In this study, we report for the first time on the convection phenomenon for the consistent and sensitive detection of target materials (particulate matter (PM) or gases) with a high-performance transparent heater. The high-performance transparent heater, based on Pt-decorated Ni micromesh, was fabricated by a combination of transfer printing process and Pt sputtering. The resulting transparent heater exhibited excellent mechanical durability, adhesion with substrates, flexibility, and heat-generating performance. We monitored the changes in the PM concentration and temperature in an airtight chamber while operating the heater. The temperature in the chamber was increased slightly, and the PM2.5 concentration was increased by approximately 50 times relative to the initial state which PM is deposed in the chamber. We anticipate that our experimental findings will aid in the development and application of heaters for sensors and actuators as well as transparent electrodes and heating devices. (C) 2017 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license.

We are here concerned with fabrication possibility of multiparametric gas sensor based on porous silicon. In order to use the porous silicon as a gas sensor, we made the DBR (distributed Bragg reflector) porous silicon onto silicon wafer and monitored the change of three parameters during exposure of DBR porous silicon to ethanol gas. The sensing parameters were the shift of reflectance peak, the PL (photoluminescence) intensity, and the electrical conductance. As a result, the spectra of reflectance and PL shifted toward longer wavelength. The electrical conductivity increases rapidly. After removing the gas, all sensing parameters return exactly to the initial value.

A large theoretical charge storage capacity along with a low discharge working potential renders silicon a promising anode material for high energy density lithium ion batteries. However, up to 400% volume expansion during charge-discharge cycling coupled with a low intrinsic electronic conductivity causes pulverization and fracture, thus inhibiting silicon's widespread use in practical applications. We report herein on a low cost approach to fabricate hybrid silicon nanowire (SiNW)/graphene nanostructures that exhibit enhanced cycle performance with the capability of retaining more than 90% of their initial capacity after 50 cycles. We also demonstrate the use of hot-pressing in the absence of any common polymer binder such as PVDF to bind the hybrid structure to the current collector. The applied heat and pressure ensure strong adhesion between the SiNW/graphene nano-composite and current collector. This facile yet strong binding method is expected to find use in the further development of polymer-binder free anodes for lithium ion batteries.