Microstrip lines using yttrium iron garnet film

The spectral-domain technique is used to compute the dispersion characteristics and the transverse field distributions of microstrip lines using a yttrium-iron-garnet (YIG) film on a gadolinium-gallium-garnet (GGG) substrate. Numerical results are presented to show a sharp cutoff characteristic for a large thickness of GGG (which is caused by the reduction in the negative permeability range), and to show the effect of YIG film thickness on the nonreciprocal behavior. Experiments are carried out using YIG film a few tenths of a micrometer thick and a 400-μm-thick GGG substrate. A narrow stopband characteristic of 200 MHz is observed at 6 GHz, which agrees well with theory. The application to a band-rejection filter is briefly discussed     

Systematic electrical characteristics of ideal rectangular cross section Si-Fin channel double-gate MOSFETs fabricated by a wet process

The electrical characteristics of ideal rectangular cross section Si-Fin channel double-gate MOSFETs (FXMOSFETs) fabricated by a wet process have experimentally and systematically been investigated. The almost ideal S-slope of 64 mV/decade was obtained for the fabricated 20 nm Si-Fin and 125 nm gate-length FXMOSFET. This excellent subthreshold characteristic shows that the quality of the rectangular Si-Fin channel with (111)-oriented sidewall is good enough to realize high-performance FXMOSFETs. The current and transconductance multiplication accurately proportional to a number of 30 nm Si-Fin channels was confirmed in the fabricated multi-fin FXMOSFETs. The systematic investigation of the electrical characteristics of the fabricated FXMOSFETs in the 20-110-nm Si-Fin and 2.3-5.2-nm gate oxide regimes reveals that short-channel effects can be effectively suppressed by reducing the Si-Fin thickness to 20 nm or less. The developed processes are quite attractive for fabrication of ultranarrow Si-Fin channel double-gate MOSFETs.     

Growth of diamond particles from methane-hydrogen gas

Microcrystals of diamond were grown on non-diamond substrates including silicon, molybdenum and silica, as well as on diamond by chemical vapour deposition. Deposition was carried out by passing a mixture of hydrocarbon and hydrogen gases through a heated reaction chamber in which a hot tungsten filament was held near the substrates. The deposit was identified by reflection electron diffraction and Raman spectroscopy. The effects of experimental conditions on the growth features were studied.     

Promotion of allergic immune responses by intranasally-administrated nanosilica particles in mice

With the increase in use of nanomaterials, there is growing concern regarding their potential health risks. However, few studies have assessed the role of the different physical characteristics of nanomaterials in allergic responses. Here, we examined whether intranasally administered silica particles of various sizes have the capacity to promote allergic immune responses in mice. We used nanosilica particles with diameters of 30 or 70 nm (nSP30 or nSP70, respectively), and conventional micro-sized silica particles with diameters of 300 or 1000 nm (nSP300 or mSP1000, respectively). Mice were intranasally exposed to ovalbumin (OVA) plus each silica particle, and the levels of OVA-specific antibodies (Abs) in the plasma were determined. Intranasal exposure to OVA plus smaller nanosilica particles tended to induce a higher level of OVA-specific immunoglobulin (Ig) E, IgG and IgG1 Abs than did exposure to OVA plus larger silica particles. Splenocytes from mice exposed to OVA plus nSP30 secreted higher levels of Th2-type cytokines than mice exposed to OVA alone. Taken together, these results indicate that nanosilica particles can induce allergen-specific Th2-type allergic immune responses in vivo. This study provides the foundations for the establishment of safe and effective forms of nanosilica particles.     

In-vitro characterization of YM872, a selective, potent and highly water-soluble alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor antagonist

The in-vitro pharmacological properties of (2,3-dioxo-7-(1H-imidazol-1-yl)-6-nitro-1,2,3,4-tetrahydro-1-quinoxal inyl)-acetic acid monohydrate, YM872, a novel and highly water-soluble alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)-receptor antagonist were investigated. YM872 is highly water soluble (83 mg mL(-1) in Britton-Robinson buffer) compared with 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline (NBQX), 6-(1H-imidazol-1-yl)-7-nitro-2,3(1H,4H)-quinoxalinedione hydrochloride (YM90K) or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). YM872 potently inhibits [3H]AMPA binding with a Ki (apparent equilibrium dissociation constant) value of 0.096 +/- 0.0024 microM. However, YM872 had very low affinity for other ionotropic glutamate receptors, as measured by competition with [3H]kainate (high-affinity kainate binding site, concentration resulting in half the maximum inhibition (IC50) = 4.6 +/- 0.14 microM), [3H]glutamate (N-methyl-D-aspartate (NMDA) receptor glutamate binding site, IC50 > 100 microM) and [3H]glycine (NMDA receptor glycine-binding site, IC50 > 100 microM). YM872 competitively antagonized kainate-induced currents in Xenopus laevis oocytes which express rat AMPA receptors, with a pA2 value of 6.97 +/- 0.01. In rat hippocampal primary cultures, YM872 blocked a 20-microM AMPA-induced increase of intracellular Ca2+ concentration with an IC50 value of 0.82 +/- 0.031 microM, and blocked 300-microM kainate-induced neurotoxicity with an IC50 value of 1.02 microM. These results show that YM872 is a potent and highly water-soluble AMPA antagonist with great potential for treatment of neurodegenerative disorders such as stroke.     

The dependence of hydrofluoric acid concentration during anodization on photoluminescence of porous silicon

The mixture of hydrofluoric (HF) acid and ethanol is used as an electrolyte during anodization of silicon. We investigated the effect of the ratio of HF acid to ethanol on photoluminescence. It is concluded that porous silicon anodized with the electrolyte containing 35 or 40% HF acid provides strong photoluminescence. The fact implies the existence of a chemical reaction including ethanol during anodization other than electrochemical reaction.     

Thermal seawater desalination based on self-heat recuperation

Recently a novel self-heat recuperation (SHR) technology has been developed for energy saving. In the SHR process, both sensible heat and latent heat are circulated by compression work. Energy consumption is thereby drastically reduced. Using this technology, a new thermal desalination process is developed for reducing energy consumption. The energy required for this SHR-based process is explained by process simulation. It requires ~1/4 the energy of the conventional multi-stage flash desalination process, which is the most widely used thermal desalination. Thus, the proposed thermal desalination process is promising for application in industrial plants.     

Pulsed current water splitting electrochemical cycle for hydrogen production

A pulsed current 3 D MnO₂ electrode water splitting electrochemical cycle is being proposed for hydrogen production. In 3D MnO₂ electrochemical cycle, the reactions take place at the solid/liquid and solid/gas two phase boundaries. Also, this electrochemical cycle should be able to generate hydrogen and oxygen gas separately at different periods of time. Here, we applied an interrupted pulsed current to reduce the overpotential caused by diffusion layers in conventional direct current electrolysis. The pulsed current, which disturbs the formation of the ion diffusion layer in the vicinity of the electrodes, is observed to be effective above 50 Hz. The best electrolysis performance was recorded at a current density of 0.2 A cm^?2, and the observed cell voltage was 1.69 V at 25 °C for a pulse frequency of 500 Hz, which is less than the corresponding conventional alkaline electrolysis.     

Microstructural Characteristics and Mechanical Properties of Friction Stir Welded Thick 5083 Aluminum Alloy

Metallurgical and Materials Transactions A - Joining thick sections of aluminum alloys by friction stir welding (FSW) in a single pass needs to overcome many challenges before it comes to...