As the demand for electric vehicles increases, the stability of batteries has become one of the most significant issues. The battery housing, which protects the battery from external stimuli such as vibration, shock, and heat, is the crucial element in resolving safety problems. Conventional metal battery housings are being converted into polymer composites due to their lightweight and improved corrosion resistance to moisture. The transition to polymer composites requires high mechanical strength, electrical insulation, and thermal stability. In this paper, we proposes a high-strength nanocomposite made by infiltrating epoxy into a 3D aligned h-BN structure. The developed 3D aligned h-BN/epoxy composite not only exhibits a high compressive strength (108 MPa) but also demonstrates excellent electrical insulation and thermal stability, with a stable electrical resistivity at 200 °C and a low thermal expansion coefficient (11.46×ppm/°C), respectively.

In this study, two alignment methods were used to create a Fringe-Field Switching (FFS) mode liquid crystal device using an organic thin film (polyimide: PI) as an alignment layer. In addition, the electro-optical (EO) characteristics of the liquid crystal device manufactured in this way were investigated to evaluate the feasibility of mass production application of the technology. In general, the photo-alignment method using unpolarized ultraviolet rays can obtain a relatively low pretilt angle, so a liquid crystal device in FFS mode, which is a driving mode of the liquid crystal device that reflects the characteristics of liquid crystal alignment, was manufactured, and the liquid crystal has a high reactivity with the alignment film. Considering this, nematic liquid crystal (NLC) was used. In addition, in order to improve the misalignment, it was observed whether more stable orientation occurred by irradiating ultraviolet rays for an additional 1 to 3 hours in the aligned state. As a result of the experiment, it was found that NLC alignment occurs through a photodecomposition reaction caused by unpolarized UV irradiation oblique to the PI surface. In addition to the existing orientation method, UV irradiation was used to achieve a more stable orientation state and stable V-T curve and response characteristics. With liquid crystal alignment completed, more stable orientation characteristics and EO characteristics at the mass production level were obtained through additional UV irradiation for 3 hours. This method can further stabilize the orientation stability caused by existing UV irradiation through an additional process.

Vertically Aligned Carbon Nanotubes (VACNTs)-coated flexible aluminium (Al) foil is studied as an electrode for supercapacitor applications. VACNTs are grown on Al foil inside thermal Chemical Vapor Deposition (CVD) reactor. 20 nm thick layer of Fe is used as a catalyst while Ar, H2 and C2H2 are used as precursor gases. The effect of growth temperature on the structure of CNTs is studied by varying the temperature of CVD reactor from 550 °C to 625 °C. Better alignment of VACNTs arrays on Al foil is recorded at 600 °C growth temperature in comparison to other processing temperatures. Cyclic voltammetry results shows that VACNTs-coated Al foil has a specific capacitance of ~ 3.01 F/g at a scan rate of 50 mV/s. The direct growth of VACNT array results in better contact with Al foil and thus low ESR values observed in impedance spectroscopy analysis. This leads to a fast charge–discharge cycle as well as a very high value of power density (187.79 kW/ kg) suitable for high power applications. Moreover, wettability study shows that the fabricated VACNT electrode has a contact angle of more than 152° which signifies that it is a superhydrophobic surface and hence shows lower specific capacitance in comparison to reported values for VACNT array. Therefore, it is necessary to develop suitable post-processing strategies to make VACNTs hydrophilic to realize their full potential in supercapacitor applications.

Abstract We demonstrate convenient alignment technologies using imprinting lithography with sol-gel process. The aligned nano pattern is fabricated on a silicon wafer by laser interference lithography. For conformal imprinting process, aligned nano pattern was transferred onto the polydimethylsiloxane (PDMS). Using a PDMS sheet with aligned nano pattern, aligned nano pattern was created onto the sol-gel driven hafnium zinc oxide by imprinting lithography. The process was conducted at annealing temperatures of 150 °C. The obtained pattern on the HfZnO film acted as a guide for aligning liquid crystal (LC) molecules. The geometric restriction induced by aligned pattern leads to LC alignment along to the aligned nano pattern. The combination of imprint lithography and solution-processed inorganic materials proved good alternative of LC alignment technique.

The characteristics of CNT-Polyamide composites were analyzed, that is, tensile strength, electrical resistivity, and thermal conductivity were measured according to the align length of CNT. There have been researches on the influence of aligned CNT to improve the mechanical and thermal characteristics in different areas including absorption and shielding of electromagnetic wave, thermal distribution or absorption, and high-strength of CNT. The aligned CNTs were synthesized by the ethylene gas with a CVD device preheated at 650℃. CNT-Polyamide composites were produced with the mixing of solution. CNT contents were controlled from 1phr to 50phr in the polyamide-ethanol solution, and blended with the 700W bar-type ultrasonic wave for 60 min.. And then CNT-polyamide were precipitated by CNT-polyamide-etnanol falling into the cold water. After dried 12 hours, CNT-polyamide composite were pressed at 150℃~180℃ with 400kgf to get the thickness of 1mm. As the conclusions, aligned CNT bundles were dispersed by cutting of CNT to the aligned direction because of polyamide properties. Tensile strength and electrical resistivity were improved to the increase of aligned length of CNT. Thermal conductivity was little affected by the align length of CNT.

The monolayer engineering diamond particles are aligned on the oxygen free Cu plates with electroless Ni plating layer. The mean diamond particle sizes of 15, 23 and 50 μm are used as thermal conductivity pathway for fabricating metal/carbon multi-layer composite material systems. Interconnected void structure of irregular shaped diamond particles allow dense electroless Ni plating layer on Cu plate and fixing them with 37-43% Ni thickness of their mean diameter. The thermal conductivity decrease with increasing measurement temperature up to 150oC in all diamond size conditions. When the diamond particle size is increased from 15 μm to 50 μm (Max. 304 W/mK at room temperature) tended to increase thermal conductivity, because the volume fraction of diamond is increased inside plating layer.

This paper proposes a novel way of fabricating aligned porous Sn by freeze-drying of camphene slurry with stannic oxide (SnO2) coated Sn powders. The SnO2 coated Sn powders were prepared by surface oxidation of the initial and ball-milled Sn powders, as well as heat treatment of tin chloride coated Cu powders. Camphene slurries with 10 vol% solid powders were prepared by mixing at 50 oC with a small amount of oligomeric polyester dispersant. Freezing the slurry was done in a Teflon cylinder attached to a copper bottom plate cooled at −25 oC. Improved dispersion stability of camphene slurry and the homogeneous frozen body was achieved using the oxidized Sn powder at 670 oC in air after ball milling. The porous Sn specimen, prepared by freeze-drying of the camphene slurry with oxidized Sn powder from the heat-treated Sn/tin chloride mixture and sintering at 1100 oC for 1 h in a hydrogen atmosphere, showed large pores of about 200 μm, which were aligned parallel to the camphene growth direction, and small pores in their internal walls. However, 100 μm spherical particles were observed in the bottom part of the specimen due to the melting of the Sn powder during sintering of the green compact.

The purpose of this study was to evaluate the differences in electromyographic (EMG) activities of upper limb muscles between cross- and parallel-aligned taping and to compare the effects of these 2 taping methods in healthy adults. Thirty subjects, who volunteered for this study, were tested under 3 taping conditions in random order: (1) no taping, (2) cross-aligned taping, and (3) parallel-aligned taping. EMG activities of the biceps brachii, triceps brachii, flexor carpi ulnaris, and extensor carpi radialis muscles were measured. All muscles showed significant differences in EMG activity among the 3 conditions (p<.05). In the post hoc test, biceps brachii and triceps brachii muscles showed significant differences in EMG activity between the no taping and the cross-aligned taping conditions and between the no taping and the parallel-aligned taping conditions. Additionally, the EMG activities of the flexor carpi radialis and extensor carpi radialis muscles appeared to be significantly different between the no taping and parallel-aligned taping conditions. These findings demonstrate that taping may be helpful for decreasing muscle activity, regardless of the direction of tape application. This study provides useful information to future researchers regarding the effects of taping on muscle activity.

We investigated the effects of parametric synthesis conditions of catalysts such as sintering temperature, sorts of supports and compositions of catalysts on alignment and length-control of carbon nanotubes (CNTs) using catalyst powders. To obtain aligned CNTs, several parameters were changed such as amount of citric acid, calcination temperature of catalysts, and the sorts of supports using the combustion method as well as to prepare catalyst. CNTs with different lengths were synthesized as portions of molybdenum and iron using a chemical vapor deposition reactor. In this work, the mechanisms of alignment of CNTs and of the length-control of CNTs are discussed.

A simple thermal oxidation of Cu thin films deposited on planar substrates established a growth of vertically aligned copper oxide (CuO) nanorods. DC sputter-deposited Cu thin films with various thicknesses were oxidized in environments of various oxygen partial pressures to control the kinetics of oxidation. This is a method to synthesize vertically aligned CuO nanorods in a relatively shorter time and at a lower cost than those of other methods such as the popular hydrothermal synthesis. Also, this is a method that does not require a catalyst to synthesize CuO nanorods. The grown CuO nanorods had diameters of ~100 nm and lengths of 1~25μm. We examined the morphology of the synthesized CuO nanorods as a function of the thickness of the Cu films, the gas environment, the oxidation time, the oxidation temperature, the oxygen gas flow rate, etc. The parameters all influence the kinetics of the oxidation, and consequently, the volume expansion in the films. Patterned growth was also carried out to confirm the hypothesis of the CuO nanorod protrusion and growth mechanism. It was found that the compressive stress built up in the Cu film while oxygen molecules incorporated into the film drove CuO nanorods out of the film.

Polyacetylene (PA) films with vertically aligned fibril morphology were synthesized in homeotropic nematic liquid crystal (N-LC) solvent by using a magnetic field of 5 Tesla as an external perturbation. Scanning electron microscope (SEM) photographs indicated that the lengths of fibrils from the substrate were 5-35μm, depending on polymerization time. Carbonization was carried out using iodine-doped PA film and a morphology-retaining carbonization method. From the SEM results, we confirmed that the vertical morphology of the PA remains unchanged even after carbonization at 800℃. The weight loss of the films due to carbonization at 800℃ is about 20% of the weight of the film before iodine doping. It is expected that vertically aligned carbon might be a precursor for preparing vertical graphite materials, which materials could be useful for electrochemical energy storage and cell electrodes.

본 연구는 두꺼운 난류경계층 내에 일정한 간격을 가진 정입방체의 유동특성에 대해 연구이다. 건물주위에 다른 건물이 위치함으로써 본 건물에 미치는 영향을 알아보기 위해 방위각을 0~90o로 변화시키면서 단일모델과 연속적으로 배열된 모델의 표면압력을 측정하였다. 실험은 큐브의 높이h에서 측정한 유속U에 근거한 레이놀즈수 4.6×104, 6.7×104 2가지로 하였다. 연구결과 레이놀즈 효과는 평균압력특성에 거의 영향을 끼치지 않았으며 방위각이 증가함에 따라 전면부에서 표면압력이 감소하고 후면에서는 증가하는 경향이 나타났다. 또한 모서리에서 발생한 유동박리는 큐브상부 뿐만 아니라 측면의 표면압력특성에 상당한 영향을 나타내었다.

Well-aligned multi-walled carbon nanotubes (MWCNTs) were successfully synthesized by catalytic chemical vapor deposition using a hydrogen sulfide (H2S) additive onto Al/Fe thin film deposited on Si wafers. Transmission electron microscopy images indicated that the as-grown carbon products were thin MWCNTs with small outer diameters of less than 10 nm. H2S plays a key role in synthesizing thin MWCNTs with a large inside hollow core. The well-aligned thin MWCNTs showed a low turn-on voltage of about 1.1 V/μm at a current density of 0.1 μA/cm2 and a high emission current of about 1.0 mA/cm2 at a bias field of 2.3 V/μm. We suggest a possible growth mechanism for the well-aligned thin MWCNTs with a large inside hollow core.