Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

Experimental study of turbulent swirling flow in a straight pipe.

Abstract: Swirling flow through a pipe is a highly complex turbulent flow and is still challenging to predict. An experimental investigation is performed to obtain systematic data about the flow and to understand its physics. A free-vortex-type swirling flow is introduced in a long straight circular pipe. The swirling component decays downstream as a result of wall friction. The velocity distributions are continuously changing as they approach fully developed parallel flow. The swirl intensity Ω, defined as a non-dimensional angular momentum flux, decays exponentially. The decay coefficients, however, are not constant as conventionally assumed, but depend on the swirl intensity. The wall shear stresses are measured by a direct method and, except in a short inlet region, are a function only of the swirl intensity and the Reynolds number. The velocity distributions and all Reynolds stress components are measured at various axial positions in the pipe. The structure of the tangential velocity profile is classified into three regions: core, annular and wall regions. The core region is characterized by a forced vortex motion and the flow is dependent upon the upstream conditions. In the annular region, the skewness of the velocity vector is noticeable and highly anisotropic so that the turbulent viscosity model does not work well here. The tangential velocity is expressed as a sum of free and forced vortex motion. In the wall region the skewness of the flow becomes weak, and the wall law modified by the Monin–Oboukhov formula is applicable. Data on the microscale and the spectrum are also presented and show quite different turbulence structures in the core and the outer regions.

Solvothermal Synthesis of Multiple Shapes of Silver Nanoparticles and Their SERS Properties

Abstract: The controllable synthesis of nanocrystals with different shapes is very important and challenging. In the present work, silver nanoparticles with different structural architectures, from nanorods, triangular plates, hexagonal plates, and nanocubes to polyhedrons have been synthesized successfully in high yield by a solvothermal process. Especially, the unique silver enneahedral nanoplates are also observed. These nanoparticles exhibit tunable surface plasmon resonance properties from the visible to near-infrared regions. Those nanoparticles were also self-assembled on glass substrates and evaluated as potential surface-enhanced Raman scattering (SERS) substrates using trans-1,2-bis(4-pyridyl)ethylene molecules. Thanks to the enhanced local field effect around their sharp corners and edges, those Ag triangular plates exhibit enhanced SERS properties and can serve as high-sensitivity substrates for SERS-based measurements.

Semiconductorlike Behavior of Electrical Resistivity in Heusler-type Fe 2 VAl Compound

Abstract: An anomalous negative temperature dependence of electrical resistivity has been observed in $({\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{V}}_{x}{)}_{3}\mathrm{Al}$ alloys with V compositions up to $x\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.35$. In particular, the Heusler-type ${\mathrm{Fe}}_{2}\mathrm{VAl}$ compound is found to be on the verge of magnetic ordering and to exhibit a semiconductorlike behavior with the resistivity reaching $3000\ensuremath{\mu}\ensuremath{\Omega}\mathrm{cm}$ at 2 K, in spite of the possession of a clear Fermi cutoff as revealed in photoemission valence-band spectra. A substantial mass enhancement deduced from specific heat measurements suggests that ${\mathrm{Fe}}_{2}\mathrm{VAl}$ is a possible candidate for a $3d$ heavy-fermion system.

A light-driven sodium ion pump in marine bacteria

Abstract: Light-driven proton-pumping rhodopsins are widely distributed in many microorganisms. They convert sunlight energy into proton gradients that serve as energy source of the cell. Here we report a new functional class of a microbial rhodopsin, a light-driven sodium ion pump. We discover that the marine flavobacterium Krokinobacter eikastus possesses two rhodopsins, the first, KR1, being a prototypical proton pump, while the second, KR2, pumps sodium ions outward. Rhodopsin KR2 can also pump lithium ions, but converts to a proton pump when presented with potassium chloride or salts of larger cations. These data indicate that KR2 is a compatible sodium ion-proton pump, and spectroscopic analysis showed it binds sodium ions in its extracellular domain. These findings suggest that light-driven sodium pumps may be as important in situ as their proton-pumping counterparts.

Recent Development of Open-Source Speech Recognition Engine Julius

Abstract: Julius is an open-source large-vocabulary speech recognition software used for both academic research and industrial applications. It executes real-time speech recognition of a 60k-word dictation task on low-spec PCs with small footprint, and even on embedded devices. Julius supports standard language models such as statistical N-gram model and rule-based grammars, as well as Hidden Markov Model (HMM) as an acoustic model. One can build a speech recognition system of his own purpose, or can integrate the speech recognition capability to a variety of applications using Julius. This article describes an overview of Julius, major features and specifications, and summarizes the developments conducted in the recent years.