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Experimental investigations on the atomization characteristics of twin-fluid water mist nozzle were conducted using particle image velocimetry (PIV) system and particle motion analysis system (PMAS). The twin-fluid water mist nozzles with swirlers designed two types of swirl angles such as 0°, 90° and three different size nozzle hole diameters such as 0.5mm, 1mm, 1.5mm were employed. The experiments were carried out by the injection pressure of water and air divided into 1bar, 2bar respectively. The droplet size of the spray was measured using PMAS. The velocity and turbulence intensity were measured using PIV. The velocity, turbulence intensity and SMD distributions of the sprays were measured along the centerline and radial direction. As the experimental results, swirl angle controlled to droplet sizes. It was found that SMD distribution decreases with the increase of swirl angle. The developed twin-fluid water mist nozzle was satisfied to the criteria of NFPA 750, Class 1. It was proven that the developed nozzle under low pressures could be applied to fire protection system.

Sulfonated poly(fluorinated arylene ether)s (SDF-F)/poly[(N-vinylimidazole)-co-(3-methacryloxypropyl-trimethoxysilane)] (poly(VI-co-MPS))/poly(tetrafluoroethylene) (PTFE) is prepared for a high temperature proton exchange membrane fuel cell (PEMFC). The reaction of the membrane with phosphoric acid forms silicate phosphor, as a chemically bound proton carrier, in the membrane. Thus-formed silicate phosphor, nitrogen in the imidazole ring, and physically bound phosphoric acid act as proton carriers in the membrane. The physico-chemical and electrochemical properties of the membrane are investigated by various analytical tools. The phosphoric acid uptake and proton conductivity of the SDF-F/poly(VI-co-MPS)/PTFE membrane are higher than those of SDF-F/PVI/PTFE. The power densities of cells with SDF-F/poly(VI-co-MPS)/PTFE membranes at 0.6 V are 286, 302, and 320 mW at 150, 170, and 190 , respectively. Overall, the SDFF/poly(VI-co-MPS)/PTFE membrane is one of the candidates for anhydrous HT-PEMFCs with enhanced mechanical strength and improved cell performance.

The degradation of cathode materials due to the so-called ‘NiO dissolution’ problem, is one of the most critical issues restricting the long-term operation of molten carbonate fuel cells (MCFCs). To overcome this problem, a modified NiO powder is prepared by the annealing of a pre-mixed powder consisting of Ni powder and Co 3 O 4 nano-particles ( n -Co 3 O 4 ) at 650 °C. Annealing above 300 °C plays an important role in converting the physically bound mixed oxide system to a chemically bound system and, therefore, the separation of n -Co 3 O 4 from Ni is prevented. This modification leads to the formation of a Ni 0.9 Co 0.1 O solid solution, and the lithiated Ni 0.9 Co 0.1 O has a core–shell structure that consists of different Li contents. Whereas the core phase has a low concentration of lithium, the outer layer is a highly lithiated phase. Since the highly lithiated outer phase, acting as a barrier, minimizes the dissolution of NiO, the modified cathode demonstrates good electrochemical properties and chemical stability under actual operating conditions. This study can provide an effective way to mass produce MCFC cathode materials.

This study presents the development of refined three dimensional (3D) finite element (FE) models with the ability to reliably simulate the mechanical behavior of full-scale bolted T-stub connections. FE models incorporated material nonlinearity, geometric nonlinear behavior, several contact interactions between faying surfaces, and prescribed displacements for generating initial bolt pretension. These FE models were used to compare experimental test results, which verify that advanced FE modeling methods make a notable contribution to reproducing the overall behavior of connections and components accurately, including the moment-rotation curves. In addition, the FE models provide some useful information which is difficult to obtain during physical testing, i.e., the distribution of stress and strain, friction forces between shear faying surfaces, and bolt reaction forces. The validated FE models are also used for additional parametric studies so as to comprehensively understand their response mechanisms. Moreover, the observation of FE analysis results supports the statement that connection models presented herein were designed to reach the yielding of connection components when the structural beam produces its full plastic moment at the plastic hinge.

We have successfully synthesized a new superconductor EuSr 2 Cu 2 Ta 1− x Sn x O 8− y of the so-called Ta-1212 system, where Ta is substituted for Cu(1) in the Y-123 type structure and holes are doped into the CuO 2 plane through the partial substitution of Sn 4+ for Ta 5+ . The superconducting transition temperature, T c , is about 40 K at x = 0.2. This is the first superconductor in the Ta-1212 system.

Various TiO2-coated ZnO samples were prepared by the sol−gel method for use as the anode active materials of Ni−Zn secondary batteries. At a low annealing temperature, the added titanium does not r...

DNA vaccines have emerged as an attractive approach to generate antigen-specific T-cell immune response. Nevertheless, the potency of DNA vaccines still needs to be improved for cancer immunotherapy. In this study, we explored whether functional linkage of a Th1-polarizing chemokine, IP-10, to a model tumor antigen, human papillomavirus type 16 (HPV-16) E7, enhanced DNA vaccine potency. IP-10 linkage changed the location of E7 from the nucleus to the endoplasmic reticulum and led to the secretion of functionally chemoattractive chimeric IP-10/E7 protein. In addition, this linkage drastically enhanced the endogenous processing of E7 antigen through MHC class I. More importantly, we found that C57BL/6 mice intradermally vaccinated with IP-10/E7 DNA exhibited a dramatic increase in the number of E7-specific CD4(+) Th1 T-cells and CD8(+) T-cells and, consequently, were strongly resistant over the long term to E7-expressing tumors compared to mice vaccinated with wild-type E7 DNA. Thus, because of the increase in tumor antigen-specific T-cell immune responses obtained through both enhanced antigen presentation and chemoattraction, vaccination with DNA encoding IP-10 linked to a tumor antigen holds great promise for treating tumors.

LiMn 1.5 Ni 0.5 O 4 materials coated with AlPO 4 are prepared by a sol–gel method with citric acid to improve their electrochemical performance; the physical and electrochemical properties are characterized by various analytical techniques. The coated AlPO 4 layer completely covers the surfaces of the LiMn 1.5 Ni 0.5 O 4 particles and the thickness of the coated layer is ∼15 nm. 1 wt.% AlPO 4 -coated LiMn 1.5 Ni 0.5 O 4 has much lower surface and charge-transfer resistances and shows a higher lithium diffusion rate in comparison with the pristine sample. The modified material demonstrates dramatically enhanced electrochemical reversibility and stability under elevated temperature conditions. This is because the coated AlPO 4 layer reduces the contact area between the electrode and electrolyte and suppresses the formation of undesirable solid electrolyte interface films.

A tunable Fabry-Perot interferometer (TFPI)-type wavelength filter designed for the long-wavelength infrared (LWIR) region is fabricated using micro electro mechanical systems (MEMS) technology and the novel polydimethylsiloxane (PDMS) micro patterning technique. The structure of the proposed infrared sensor consists of a Fabry-Perot interferometer (FPI)-based optical filter and infrared (IR) detector. An amorphous Si-based thermal IR detector is located under the FPI-based optical filter to detect the IR-rays filtered by the FPI. The filtered IR wavelength is selected according to the air etalon gap between reflectors, which is defined by the thickness of the patterned PDMS. The 8 &mu, m-thick PDMS pattern is fabricated on a 3 nm-thick Al layer used as a reflector. The air etalon gap is changed using the electromagnetic force between the permanent magnet and solenoid. The measured PDMS gap height is about 2 &mu, m, ranging from 8 &mu, m to 6 &mu, m, with driving current varying from 0 mA to 600 mA, resulting in a tunable wavelength range of 4 &mu, m. The 3-dB bandwidth (full width at half maximum, FWHM) of the proposed filter is 1.5 nm, while the Free Spectral Range (FSR) is 8 &mu, m. Experimental results show that the proposed TFPI can detect a specific wavelength at the long LWIR region.

C의 용융탄산염과 산소 분위기조건에서 안정하고 높은 전기 전도도를 가지는 장점이 있다. 그러나, 장시간 운전 시 양극에서전해질로의 Ni dissolution은 전지 내부의 단락을 초래하여 전지의 수명을 단축시킨다. 본 연구에서는 대체 전극물질로서 코발트와 나이오븀을 코팅시킨 NiO 전극을 제조하였으며, 이렇게 제조된 전극은 기존 NiO전극과 비교하여 낮은 Ni dissolution과 안정되고 우수한 전기화학 성능을보임을 확인하였다.Abstract: NiO is commonly used as the cathode for the molten carbonate fuel cell due to itsstability and high electrical conductivity in molten carbonates and oxygen atmosphere. However,long-term operation of MCFC has a serious problem which is the degradation of cathode material,the so-called Ni dissolution. In the present study, we have attempted to synthesize a new alter-native cathode material as Co/Nb-coated NiO cathode. The results obtained in this study suggestthat the Co/Nb-coated NiO cathode can be utilized as having lower dissolution and higher cellperformance than those of the pure NiO cathode.Keyword: MCFC, Cathode, Ni dissolution

Polycrystalline samples of RE 0.6Ca0.4Ba1.6Sr0.4Cu3O6 (RE = Nd, Gd, Dy, Y, Yb, Lu) without oxygen in the Cu(1)O chain have been prepared by the conventional solid-state reaction method. No superconductivity appears for larger RE = Nd, Gd, Dy, while superconductivity with T c ~50 K appears for smaller RE = Y, Yb, Lu. This is presumably because holes produced by the Ca-substitution for RE are more supplied to the conductive Cu(2)O2 plane than to Cu(1) as the lattice becomes small. The maximum T c = 53 K for RE = Lu is considerably lower than 90 K for REBa2Cu3O7. This may be due to the low hole-concentration in the Cu(2)O2 plane.

Pem, a member of homeobox genes, is an oncofetal gene which is preferentially expressed in reproductive tissues and in multiple tumor cell lines. However, the function of Pem in tumor cell lines has not been elucidated. Herein we report that the ectopic expression of Pem in TC-1, a human papillomavirus type 16 (HPV-16) E7-expressing surrogate cervical tumor cell line, demonstrated a significant increase in extracellular signal-regulated kinase (ERK) activity and multiple resistance to various apoptotic pressures from an E7-specific CD8(+) T cell-mediated immune response and anticancer drug treatment. The observed resistance to apoptotic death of the Pem-over-expressing TC-1 tumor cells (TC-1/Pem) was associated with the down-regulation of a pro-apoptotic molecule, such as BIM, and up-regulation of an anti-apoptotic molecule, such as Bcl-2 protein, which mediated ERK activation. We also observed that the intratumoral injection of an ERK inhibitor enhanced the therapeutic efficacy of E7-specific CD8(+) T cell adoptive transfer or anticancer drug treatment against the resistant TC-1/Pem tumor. This is the first evidence demonstrating an association between Pem and a signaling pathway, namely the ERK-mediated survival signal transduction pathway. Thus, our data indicate that activation of the ERK pathway represents a new mechanism of Pem-mediated multiple resistances and the present research will contribute to the development of a novel strategy in cancer therapy against Pem-over-expressing tumor cells.

The debris generated by the explosion of a building or ammunition is flown far away through the ricochet phenomenon. The debris contains a very large amount of energy, and a risk factor surrounding it may be applied. The safety distance from debris is set from experiments or FEM analysis. The ricochet of debris is affected not only by the initial conditions of the debris, but also by the conditions of the medium. In this paper, the effect of sand temperature on the ricochet of sphere projectiles was investigated through experiments and FEM, by measuring the shear stress and internal friction angle when the sand temperature increases. As the temperature of the sand increases, the shear stress and the internal friction angle decrease, and the penetration depth of the projectile increases. As the depth of penetration becomes longer, the kinetic energy is lost more by the friction force with the sand and, the sphere projectile speed decreases more. This is mainly caused by the energy loss of the projectile, so the kinetic energy of the ricocheted projectile is reduced. Therefore, when setting the optimized inhabited building distance (IBD), the conditions of the medium should be taken into account.

The surface modified LiMn2O4 materials with Li-Fe composites were prepared by a sol-gel method to improve the elec- trochemical performance of LiMn2O4 and were characterized by X-ray diffraction (XRD), X-ray photoelectron spec- troscopy (XPS), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and transmission electron microscopy (TEM)-EDS. XRD results indicate that all the samples (modified and pristine samples) have cubic spinel structures, and XRD, XPS, and TEM-EDS data reveal the formation of Li(LixFexMn2-2x)O4 solid solution on the sur- face of particles. For the electrochemical properties, the modified material demonstrated dramatically enhanced reversibility and stability even at elevated temperature. These improvements are attributed to the formation of the solid solution, and thus-formed solid solution phase on the surface of LiMn2O4 particle reduces the dissolution of Mn ion and suppresses the Jahn-Teller effect.

To evaluate the analgesic efficacy of bilateral superficial cervical plexus block and combined superficial and deep cervical plexus block for incision pain, headache and posterior neck pain after thyroidectomy.Ninety patients were divided into a control group (group C, n = 30), a bilateral superficial cervical plexus group (group S, n = 30) and a bilateral combined superficial and deep cervical plexus block group (group CO, n = 30). Before general anaesthesia, we performed bilateral superficial cervical plexus block (18 ml) and combined superficial (14 ml) and deep (4 ml) cervical plexus block with 0.25% bupivacaine. Anaesthesia was maintained with propofol-remifentanil-N2O-O2.The average concentration of remifentanil was significantly reduced in group S compared with group C and group CO (1.1 +/- 0.3, 1.8 +/- 0.4, 1.8 +/- 0.7 ng ml, respectively; P0.05). The incision pain at rest and on swallowing were significantly reduced at 0, 2 and 4 h in group S compared with group C (P0.05). Headache showed a tendency to be reduced in group S and group CO, but the posterior neck pain was not different among the three groups. After surgery, the opioid and nonopioid requirement was significantly reduced in group S (P0.05). There were fewer side effects and greater patients' satisfaction in group S.Superficial cervical plexus block is a more effective technique than combined superficial and deep cervical plexus block to reduce the pain during and immediately after thyroidectomy.

Nafion®–silica nanocomposite membranes are successfully prepared by adding hydrophobic silica nanoparticles to a Nafion® solution. To distribute these nanoparticles evenly in the Nafion® matrix, various fluorosurfactants of different ionic character are employed. Fluorosurfactants with acid groups such as phosphonic acid and sulfonic acid play an important role in simultaneously increasing the homogeneous dispersion of silica nanoparticles, enhancing proton conductivity, and reducing the methanol permeability of the nanocomposite membranes. Therefore, the dispersion properties of inorganic fillers such as silica can significantly affect nanocomposite performance in direct methanol fuel cell (DMFC) applications, whereas surfactants, if used properly, can improve the nanocomposite membrane properties. In particular, a commercial fluorosurfactant containing a sulfonic acid group (Zonyl® TBS) at the end of the surfactant chain exhibits better miscibility with the Nafion® ionomer. This feature results in a reduction in the dimensional change of the nanocomposite membrane due to relatively lower water swelling and significantly reduced methanol permeability through the membrane. A membrane–electrode assembly (MEA) prepared from a Nafion®–silica nanocomposite membrane with TBS shows the highest DMFC performance in terms of voltage vs. current density (V–I) and power density vs. current density (P–I). The current densities at 0.4 V and 90 °C are 342, 508, and 538 mA cm−2 with 1, 3 and 5 M methanol being fed at the anode side, respectively.

Polymer electrolyte nanocomposite membranes were prepared by using a commercial perfluorinated sulfonic acid ionomer (Nafion ® ), nonporous hydrophilic fumed silica (Aerosil 380 ® ), and anionic fluorosurfactant (Zonyl ® TBS). The fluorosurfactant-containing an acid group, which includes sulfonic acid, contributes to well-dispersion of the silica nanoparticles and simultaneously enhances the proton conductivity of the nanocomposite membrane. Hence, the addition of inorganic fillers such as silica to the fluorosurfactant can significantly improve the properties of the Nafion ® -based polymer electrolyte nanocomposite membrane. The membranes were characterized in terms of their mechanical properties ( e.g. , dimensional change and tensile strength) and fundamental electrochemical properties ( e.g. , proton conductivity and current–voltage ( I – V ) curve). Zonyl ® TBS, a commercial anionic fluorosurfactant with sulfonic acid groups at the end of the surfactant chain, added to the Nafion ® matrix showed improved mechanical and electrochemical properties. The sulfonic acid groups in Zonyl ® TBS allowed for the additional transport of protons. As a result, the nanocomposite membrane with surfactant exhibited an improved performance. In a single cell test on a proton exchange membrane fuel cell (PEMFC), a membrane electrode assembly (MEA) prepared from the Nafion ® –silica nanocomposite membrane with TBS exhibited the highest PEMFC performance. The cell was fed with H 2 and O 2 humidified at 75 °C for 80 °C, respectively at ambient pressure. The current density of this membrane was 1600 mA cm −2 at 0.6 V and 80 °C, superior to 999 mA cm −2 for Nafion ® 112.

Trioctylphosphine (TOP)/Pd composites have been synthesized and used as a methanol-barrier material to modify the surface of Nafion 115. The TOP/Pd composites have been applied to the surface of Nafion instead of being incorporated into the Nafion matrix, to provide the best chance of maintaining the inherent proton conductivity of Nafion. The properties of the TOP/Pd-modified membrane, in terms of its conductivity and methanol permeability, as well as the performance of the membrane electrode assembly (MEA) in direct methanol fuel cell (DMFC), have been analyzed and compared with those of bare Nafion. The DMFC performance of the TOP/Pd-modified membrane is somewhat better than that of the bare Nafion one at methanol concentration of 2 M and significantly better at a high concentration of 5 M. The TOP/Pd-modified membrane is able to operate the DMFC using a high concentration of methanol, which can satisfy the requirement to reduce the reactant volumes for portable applications as well as to achieve high performance. In contrast to bare Nafion, the TOP/Pd-modified membrane with its well-adhering and crack-free modified surface shows effect on reducing the methanol loss.

The consolidation process of ultra fine Si powders, generated as by-product during the decomposition process of silane gases, was systematically investigated for use as economical solar-grade feedstock. Si powder compacts were tried to fabricate by a consolidation process without a binding agent and then their density ratio and strength were evaluated. The Si powders in as-received state were not pure enough to be used alone as solar grade feedstock material. After the adequate chemical treatments, a sufficiently high purity above solar-grade was able to be achieved.

： The characteristics of flow on unventilated dual jets was experimentally investigated. The two nozzles each with an aspect ratio of 20 were separated by 6 nozzle widths. Reynolds number based on nozzle width was set to 5,000 by nozzle exit velocity. All measurements were made over a range of nozzle-to-nozzle angles from 0 o to 25 o . The particle image velocimetry and pressure transducer were employed to measure turbulent velocity components and mean static pressure, respectively. It was shown that a recirculation zone with sub-atmospheric static pressure was bounded by the inner shear layers of the individual jets and the nozzles plated. As nozzle-to-nozzle inclined angles were decreased, it was found that the spanwise turbulent intensity is greater than the streamwise turbulent intensity in the merging region. In the combined region, the velocity of dual jets agree well with that of single jet, but the turbulence intensity of dual jets not agree with that of single jet. Key words

Nafion is modified by incorporating poly(1-vinylimidazole)/Pd composites into the ion cluster channels of the membrane. The poly(1-vinylimidazole)/Pd-impregnated (PVI/Pd-impregnated) membranes is characterized by means of X-ray photoelectron spectroscopy (XPS), proton conductivity and methanol permeability measurements and compared with those of the untreated Nafion. The dependence of the membrane proton conductivity and methanol permeability on the poly(1-vinylimidazole) (PVI) and palladium contents in the PVI/Pd-impregnated Nafion is studied. The performance of the cells employing the PVI/Pd-impregnated Nafion is evaluated using a direct methanol fuel cell (DMFC) unit cell. It is found that the best cell performance is obtained when Nafion is impregnated with the PVI/Pd composite solution for 20 h. This result suggests that there exists an optimum content of palladium and PVI in the modified membrane to obtain a high-proton conductivity and low-methanol permeability that result in a high-cell performance.

We prepared a novel phosphoric acid-doped sulfonated poly(fluorinated arylene ether)s/poly(N-vinylimidazole) blend polymer and poly(tetrafluoroethylene) (PTFE) layered membrane. The thermal and electrochemical properties of the new layered membrane were investigated by thermogravimetric analysis (TGA), electrochemical impedance spectroscopy (EIS), as well as the performance of its membrane electrode assembly (MEA). The morphology of membrane was observed with field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). The fabricated membrane shows good mechanical property comparable to PBI membrane. The conductivity of new layered membrane was similar to that of polybenzimidazole (PBI) at high temperature. The single cell test showed that new PTFE layered membrane had a good performance over 150 °C. The PTFE layered membrane can be an alternative approach for PEMFC applications at high temperature.

The velocities, turbulence intensities, Reynolds shear stresses, and turbulent kinetic energies of the flow fields around two square cylinders in a tandem arrangement were investigated using particle image velocimetry (PIV). The experiments were made for the spacing between the two cylinders ranging from s/D = 0.5 to 10.0 and two Reynolds numbers of 5,300 and 16,000. The results showed that the flow patterns at s/D≤2.0 were drastically different from those at s/D≥2.5 for both Reynolds numbers. The sudden change in the flow patterns depended on the reattachment of the shear layer separated from the upstream cylinder.

The surface of Nafion was modified by applying palladium nanoparticles as methanol barrier materials to decrease methanol crossover and improve the performance of fuel cells. The properties of the Pd-modified membrane, in terms of conductivity, methanol permeability, percentage of liquid uptake as well as the performance of its membrane electrode assembly (MEA) in the direct methanol fuel cell, were analyzed and compared with those using bare Nafion. The modified membrane showed considerable improvement on reducing methanol loss without decreasing proton conductivity. The DMFC performance of modified membrane was superior to that of bare Nafion both at a typical fuel state of 2 M and at high concentration of 5 M, implying that the palladium-modified Nafion can be a good alternative approach for DMFC applications.

More than 1800 hundreds of millions of beverage cans are manufactured yearly over the world, which will pollute the globe environment without recycle. The recycle and regeneration estates of used beverage cans are highly profitable enterprises. Vacuum technologies are mature on a large scale today, and therefore, the re-melting process of used beverage cans (UBCs) does not have to use flux. Furthermore, the coating on UBCs becomes the key factor causing poor product quality. The present paper concerns removing the coating of UBCs and compares two different kinds of methods to remove the coating: a thermal method and a chemical reagent method. A new kind of reagent, thick sulfuric acid, was employed in the chemical reagent de-coating process. The de-coating ratio in the thermal method reached 93% at most, but the de-coating ratio reached 100% within 30 min in the chemical reagent method by using thick sulfuric acid. Recycling the used thick sulfuric acid was also supplied. A titanium yellow product can be simultaneously obtained. The experiments show that the chemical reagent method is more available than the thermal method, which will enhance the purity of the regeneration product enormously.

Lithium ion secondary battery has been applied widely to portable devices, and has been studied for application to high power electric cell system such as power tool or hybrid electronic vehicle. The structure change of the electrodes materials occur when lithium ions move between electrodes. Neutron or X-rays can analyze the structure of electrode. The advantage of X-rays is convenient in test. However X-rays is scattered by electron cloud in atoms. Therefore, The elucidation for correct position of lithium is difficult with X-rays because lithium has small atomic weight. Neutron analysis techniques could solve this problem. In this review, We wish to discuss about structure analysis and the principle of structural characterization method using neutron beam source.

CeO 2 -coated LiMn 2 O 4 spinel cathode was synthesized using two-step synthesis method. All the samples exhibited a pure cubic spinel structure without any impurities in the XRD patterns. The results of the electrochemical performances on CeO 2 -coated electrode are compared to those of electrodes based on LiMn 2 O 4 spinel without CeO 2 coating. CeO 2 -coated LiMn 2 O 4 cathode improved the cycling stability of the electrode. The capacity retention of 2 wt% CeO 2 -coated LiMn 2 O 4 was more than 82% after 150 cycles between 3.0 and 4.4 V at room temperature and 82% after 40 cycles at elevated temperature of 60 °C. The amounts of dissolved manganese-ions in CeO 2 -coated LiMn 2 O 4 significantly are smaller than pristine LiMn 2 O 4 systems especially at elevated temperatures. Surface-modified LiMn 2 O 4 can suppress the dissolution reaction of manganese-ions at elevated temperature and clearly improve the cyclability of the spinel LiMn 2 O 4 cathode materials.

One of the world's poorest countries following the devastation of the Korean War, the Republic of Korea is now the world's fifth largest trading partner and a major manufacturer of semiconductors, LCDs (liquid crystal displays), digital TVs, mobile phones, automobiles, shipbuilding, and steel. The ICT sector has played an important role in this transformation, being the single most important engine of economic growth in the country. This research analyzes the impact ICT has had on the Korean economy, illustrating the main government's policies in the area and discussing their effectiveness. The Korean ICT development strategy has been based on the following elements, that should be considered by any country willing to use ICT as a growth engine: 1) leadership and commitment, 2) human capacity building, 3) institutional arrangements, 4) legal framework, and 5) presence of a funding mechanism for the implementation of ICT master plans, capable of operating even in times of economic crisis.

A novel method, a hydrothermal method, was firstly employed to prepare a catalyst of Pt supported on carbon nanotubes (Pt/CNTs) used in a proton exchange membrane fuel cell (PEMFC) in the present work. The catalyst was characterized through the IR spectrum, XRD, TEM and Image-Pro PLUS2 software. The results show that the pretreatment using a HNO 3 –H 2 O 2 redox system on CNTs opened the ports and removed a large quantity of impurities. Reaction temperature and time are important factors to determine the Pt granule size. The average size of the Pt nanoparticles is less than 1.94 nm with homogenous dispersion and narrow distribution under the optimal reaction conditions with a reaction time of 1.5 h at 140 °C. The hydrothermal method using the conventional Pt precursor H 2 PtCl 6 ·2H 2 O together with HCHO with brief operation will be a promising method to yield Pt nanoparticles for the Pt/CNTs catalyst.

LiNi 1− x Ti x O 2 (0 ≤ x ≤ 0.1) compounds have been synthesized by a direct molten-salt method that uses a eutectic mixture of LiNO 3 and LiOH salts. According to X-ray diffraction analysis, these materials have a well-developed layered structure (R3-m) and are an isostructure of LiNiO 2 . The LiNi 1− x Ti x O 2 (0 ≤ x ≤ 0.1) compounds have average particle sizes of 1–5 μm depending on the amount of Ti salt. Charge–discharge tests show that a LiNi 1− x Ti x O 2 (0 ≤ x ≤ 0.1) cathode prepared at 700 °C has an initial discharge capacity as high as 171 mA h g −1 and excellent capacity retention in the range 4.3–2.8 V at a current density of 0.2 mA cm −2 .

Olivine structure LiFePO 4 /C composite powders are synthesized as cathode materials for Li-ion batteries via a conventional solid-state reaction. Improvement in electrochemical performance has been achieved by using poly(vinyl alcohol) as the carbon sources for the as-prepared materials. The influence of the heat treatment on the physical and the electrochemical properties of LiFePO 4 /C materials is investigated. To examine the effect of added carbon content on the properties of materials, a one-step heat treatment has been employed with control of the PVA content in the precursor. Six samples were prepared with 0, 1, 3, 5, 10 and 30 wt.% PVA added to the raw materials. The particle size of LiFePO 4 decreases as the carbon content increases. Materials with medium carbon contents have a small charge-transfer resistance and thus exhibit superior electrochemical performance. Interestingly, for a LiFePO 4 /C composite with a low PVA content, an unusual plateau at 4.3 V is observed. It is considered that this is due to the Fe 3+ /Fe 4+ redox reaction of Fe 3+ compounds that are present as an impurity. For samples with a high PVA amount, a thicker carbon coating provides an obstacle to improve the electrochemical properties.

The dissolution of nickel oxide cathode in the electrolyte is one of the major technical obstacles to the commercialization of molten carbonate fuel cell (MCFC). To improve the MCFC cathode stability, the alternative cathode material for MCFC was prepared, which was made of Co/Ce-coated on the surface of Ni powder using a polymeric precursor based on the Pechini method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDAX) were employed in characterization of the alternative cathode materials. The Co/Ce-coated Ni cathode prepared by the tape-casting technique. The solubility of the Co/Ce-coated Ni cathode was about 80% lower when compare to that of pure Ni cathode under CO2:O2 (66.7:33.3%) atmosphere at 650 °C. Consequently, the fine Co/Ce-coated Ni powder could be confirmed as a new alternative cathode material for MCFC.

Investigations on alternative material for bipolar plates of PEMFC (polymer electrolyte membrane fuel cell) are becoming a research hotspot for many fuel cell researchers. In this paper, LF11 Al alloy bipolar plates via a surface plasma Au plating preparation were applied as bipolar plates. Performances and duration times of PEMFC single cells using graphite; Au-coated LF11 Al bipolar (ALABP) and Au-coated 316L stainless steel plates were compared. It was shown that ALABP exhibited preferable properties. Based on the preparations illustrated above, a kilowatt class proton exchange membrane fuel cell stack consisting of 30 cells was successfully assembled. Pure hydrogen and air were used as the fuel and oxidant, respectively, in the stack. External humidification was employed and cycle cooling water was used to remove the heat from the reaction in order to maintain a constant temperature. A Nafion 1135 membrane and Johnson-Matthy platinum on carbon with a Pt loading of 0.4 mg/cm2 were adopted as the electrolyte and catalyst, respectively. The working temperature of the stack ranged from 25 to 100°C. The stack typically worked well under conditions in which the pressure ratio of H2/air was 0.2/0.22 MPa. The output power, current and voltage were 1–1.3 kW, 40–80 A, and 26–20 V, respectively. The normal current density of the electrode was 200–800 mA/cm2, and the energy efficiency of the stack was 51%.

Organic–inorganic hybrid composite membranes have been prepared and evaluated for polymer electrolyte membrane fuel cells (PEMFCs) at 100–140 °C. A series of synthesized poly (fluorinated arylene ether)s was sulfonated by fuming sulfuric acid (20% SO3). The zirconium phosphate composite membrane was prepared by soaking the sulfonated poly (fluorinated arylene ether)s stepwise in 1 M zirconyl chloride solution and 1 M phosphoric acid solution. The chemical, thermal, and electrochemical properties of the composite membrane were investigated by thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and unit cell test. The cell performance of the zirconium phosphate sulfonated poly (fluorinated arylene ether)s composite membrane was superior to that of the starting membrane at intermediate temperature, 100–140 °C. And the cell performance with composite membrane indicated stable behavior during experimentation when operating temperature maintained at 120 °C, whereas sulfonated poly (fluorinated arylene ether)s membrane was irreversible degradation under the same condition.

The properties of a new cathode material of nano-sized TiO 2 -coated Ni powder for application in molten carbonate fuel cells (MCFCs) are investigated. The material is prepared by a sol–gel method. X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) with energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM) and Raman spectroscopy are employed to characterize the cathode material. The nano-sized TiO 2 particles are homogenously coated on the surface of the Ni powder. A stable LiTi 1− x Ni x O 2 phase is formed on the surface of the Ni powder during immersion in molten carbonate at 650 °C. The solubility of the TiO 2 -coated Ni cathode is about 50% lower compare with that of a pure Ni cathode.

Submicron-sized Li(Ni1/3Co1/3Mn1/3)O2 particles were prepared by spray pyrolysis. A polymeric precursor solution containing citric acid and ethylene glycol enabled the formation of submicron-sized Li(Ni1/3Co1/3Mn1/3)O2 spherical particles with narrow-sized distribution and non-aggregation characteristics in the spray pyrolysis. The mean sizes of the particles post-treated at temperatures of 800 and 900∘C were 380 and 770 nm. On the other hand, the Li(Ni1/3Co1/3Mn1/3)O2 particles obtained from the aqueous solution had irregular morphology and broad-sized distribution. The discharge capacity of the particles prepared from polymeric precursor solution decreased from 88 mAh/g to 135 mAh/g after 50 cycles. The particles prepared from polymeric precursor solution had high discharge capacity and good cyclic properties than those of the particles prepared from the aqueous solution.

This study is to develop a system of electric power generation utilizing the wind resources available in the domestic wind environment. We tested drag-type vortical wind turbine models, which have two different types of blades: a flat plate and circular arc shape. Through a performance test, conditions of maximum rotational speed were found by measuring the rpm of wind turbine. The rotational speed was measured by a tachometer in a wind tunnel and the tunnel wind speed was by using a pilot-static tube and a micro manometer. The performance test for a prototype was accomplished by calculating power, power coefficient, torque coefficient from the measurement of torque and rpm by a dynamometer controller From the measurements for miniature turbine models with two different blades, the circular arc shape was found to Produce a maximum rotational speed for the same wind velocity condition. Based on this result, the prototype with the circular arc blade was made and tested. We found that it produces 500W at the wind velocity of 10.8 m/s and the power coefficient was 20%.

CeO2-coated LiCoO2 particles were successfully synthesized by a sol–gel coating of CeO2 on the surface of the LiCoO2 powder and subsequent heat treatment at 700 °C for 5 h. The surface-modified and pristine LiCoO2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Auger electron spectroscopy (AES), slow rate cyclic voltammogram (CV), and differential scanning calorimetry (DSC). Cyclic voltammetry curves suggested that the CeO2 coating suppressed the phase transitions. Unlike pristine LiCoO2, the CeO2-coated LiCoO2 cathode exhibited better capacity retention than the pristine LiCoO2 electrode in the higher cutoff voltage. Differential scanning calorimetric data revealed the higher thermal stability of the CeO2-coated LiCoO2 electrode.

Fluorine-doped nanocrystalline tin dioxide materials (F:SnO 2 ) have been successfully prepared by the sol–gel process from a single molecular precursor followed by a thermal treatment at 450–650 °C. The resulting materials were characterized by FTIR spectroscopy, powder X-ray diffraction, nitrogen adsorption porosimetry (BET) and transmission electron microscopy (TEM). The mean particle size increased from 5 to 20 nm and the specific surface area decreased from 123 to 37 m 2 /g as the temperature of heat treatment was risen from 450 to 650 °C. Fluorine-doped nanocrystalline SnO 2 exhibited capacity of 560, 502, and 702 mA h/g with 48%, 50%, and 40% capacity retention after 25 cycles between 1.2 V and 50 mV at the rate of 25 mA/g, respectively. In comparison, commercial SnO 2 showed an initial capacity of 388 mA h/g, with only 23% capacity retention after 25 cycles.

Experiments were conducted to estimate the performance of drag force type vertical axis wind turbine with an opening-shutting rotor. It was operated by the difference in drag force generated on both sides of the blades. The rotational speed was measured by a tachometer in a wind tunnel and the tunnel wind speed was measured by using a pilot-static tube and a micro manometer. The performance test for a prototype was accomplished by calculating power, power coefficient, torque coefficient from the measurement of torque and rpm by a dynamometer controller. Various design parameters, such as the number of blades(B), blade aspect ratio(W/R), angle of blades and drag coefficient acting on a blade, were considered for optimal conditions. At the experiment of miniature model, maximum efficiency was found at N

The flow fields including velocities, turbulence intensities, Reynolds shear stress and turbulent kinetic energy were investigated using particle image velocimetry(PIV) to study the flow characteristics around two square cylinders in a tandem arrangement. The experiments were carried out in the range of the spacing from 1.0 to 4.0 widths of cylinder, Reynolds number of 5.310 and 1.610 respectively. Discontinuous jumping at the drag coefficient variation was found for two cylinders simultaneously when the spacing between two cylinders is varied. This phenomenon is attributed to a sudden change of the flow pattern which depends on the reattachment of the shear layer separated from the upstream cylinder. Near such a critical spacing, the changes of the flow fields as well as the effect of Reynolds number were studied in detail.

Layered Li[Ni0.5−xMn0.5−xZr2x]O2 (x = 0, 0.025) have been prepared by the mixed hydroxide and molten-salt synthesis method. The individual particles of synthesized materials have a sub-microsize range of 200–500 nm, and LiNi0.475Mn0.475Zr0.05O2 has a rougher surface than that of LiNi0.5Mn0.5O2. The Li/Li[Ni0.5−xMn0.5−xZr2x]O2 (x = 0, 0.025) electrodes were cycled between 4.5 and 2.0 V at a current density of 15 mA/g, the discharge capacity of both cells increased during the first ten cycles. The discharge capacity of the Li/LiNi0.475Mn0.475Zr0.05O2 cell increased from 150 to 220 mAh/g, which is 50 mAh/g larger than that of the Li/LiNi0.5Mn0.5O2 cell. We found that the oxidation of oxygen and the Mn3+ ion concerned this phenomenon from the cyclic voltammetry (CV). Thermal stability of the charged Li[Ni0.5−xMn0.5−xZr2x]O2 (x = 0, 0.025) cathode was improved by Zr doping.

Ordinary graphite plate was impregnated by PTFE (polytetrafluoroethylene) scattering solution to make it suitable for fuel cell collector. The feasibility of impregnation process was investigated, and the process was optimized. SEM analysis showed that the depth of impregnation process was 2.50 mm. Porosity of graphite dropped from 18.20 percent to 3.29 percent after impregnation. There is no detectable leakage of H2, even at a pressure of 0.3 MPa after impregnation with PTFE. The impregnation process has no effect on graphite resistivity. Impregnation process successfully met the requirements for fuel cell graphite collector.

A high-performance LiNi 0.8 Co 0.2 O 2 cathode was successfully fabricated by a sol–gel coating of CeO 2 to the surface of the LiNi 0.8 Co 0.2 O 2 powder and subsequent heat treatment at 700 °C for 5 h. The surface-modified and pristine LiNi 0.8 Co 0.2 O 2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), slow rate cyclic voltammogram (CV), and differential scanning calorimetry (DSC). Unlike pristine LiNi 0.8 Co 0.2 O 2 , the CeO 2 -coated LiNi 0.8 Co 0.2 O 2 cathode exhibits no decrease in its original specific capacity of 182 mAh/g (versus lithium metal) and excellent capacity retention (95% of its initial capacity) between 4.5 and 2.8 V after 55 cycles. The results indicate that the surface treatment should be an effective way to improve the comprehensive properties of the cathode materials for lithium ion batteries.

Co/Mg solid solution coated Ni powder, where Mg-doped LiCoO2 is coated on NiO in molten carbonate, has been used as a new cathode material to reduce the solubility of NiO and to maintain the advantages of NiO cathode. The (Co/Mg)-coated NiO cathode was prepared by a coating Co/Mg solid solution on the surface of the Ni powder using a PVA assisted sol–gel method. The phase changes of the (Co/Mg)-coated Ni powder after immersed into Li/K eutectic carbonate mixtures at 550 °C ∼ 850 °C for 48 h was performed by XRD and Raman. SEM was used to study the particle morphologies. Co/Mg solid solution was coated on the surface of the Ni powder and Li(NiCoMg)O2 is formed on NiO in molten carbonate. It is expected that the Li(NiCoMg)O2 phase will reduce the solubility of NiO cathode in molten carbonate.

Preparation of catalyst layer in PEMFC electrodes was investigated. Toray carbon paper was used as diffusion layer, and Johnson–Matthey 20% Pt/C was employed as catalyst. Electrode contains neither PTFE nor carbon powder. The optimal catalyst layer composition was discovered by orthogonal test method, with the use of cell voltage–current curve and cyclic voltammogram curve. The optimal amount of the Nafion (ionomer) in the catalyst layer was found to be 1.4 mg / cm 2 when Pt loading was kept at 0.4 mg / cm 2 . Power density of PEMFC achieved 0.37 W / cm 2 with air and H 2 were used at the outlet pressure of 0.1 MPa.

The characteristics of flow on two parallel plane jets was experimentally investigated. The two nozzles each with an aspect ratio of 20 were separated by 6 nozzle widths. Reynolds number based on nozzle width was set to 5,000 by nozzle exit velocity. The particle image velocimetry and pressure transducer were employed to measure turbulent velocity components and mean static pressure, respectively. In case of unventilated parallel plane jets, it was shown that a recirculation zone with sub-atmospheric static pressure was bounded by the inner shear layers of the individual jets and the nozzles plated. There was no recirculation zone in the ventilated parallel plane jets. It was found that the spanwise turbulent intensities of unventilated jets were higher than those of ventilated jets because of the interaction of jets, and the streamwise turbulent intensities of ventilated jets were higher than those of unventilated jets because of the effect of entrainment.

We have successfully synthesized new superconductor EuSr 2 Cu 2 Nb 1− x Sn x O 8− y of the so-called Nb-1212 system, where Nb is substituted for Cu1 in the RE -123 ( RE = rare earth elements) type structure by the hole-doping through the partial substitution of Sn 4+ for Nb 5+ . The highest value of the superconductivity of the superconducting transition temperature, T c , is about 40 K at x = 0.2. This is the first superconductor in the Nb-1212 system.