Hokkaido University · Earth and Planetary Sciences
Professor Koji Suzuki's research spans plasma physics, materials science, and marine biogeochemistry. His lab investigates high-density plasma generation and optimization using innovative antenna designs for industrial applications, focusing on power efficiency and reduced sputtering. In parallel, the lab develops advanced microfabricated sensors, such as high-resolution silicon tactile imagers, for precision robotics. Additionally, the group contributes to oceanographic research, particularly in nitrogen cycling and diazotroph dynamics, with a focus on global oceanic nitrogen fixation and its ecological implications.
Figures are computed from collected data and may differ slightly.
A large-diameter (50 cm) high-density plasma is produced in a few mTorr argon by inductive RF discharge using a conventional external antenna or a plasma-immersed internal antenna. A power transfer efficiency, i.e., the ratio of net power deposited into plasma to total power into the matching circuits, is measured as a function of the electron density based on a test antenna method. The measured density dependence of the power efficiency is well described by an equivalent circuit where both indu
A 32*32-element capacitive silicon tactile imager, for use in precision robotics applications where high density and high resolution are important, is discussed. The silicon chip measures 1.6 cm*1.6 cm, and is organized in an X-Y matrix of 1024 capacitor elements on 0.5-mm centers. The process uses two boron diffusions (deep and shallow) followed by a silicon-to-glass electrostatic bonding step and subsequent unmasked wafer dissolution. This results in a thick center plate for the sense capacito
In the subarctic Pacific and its adjacent waters, the photochemical quantum yield (F v /F m ) and the functional absorption cross section (Σ PSII ) of photosystem II for surface phytoplankton were continuously measured during the early summer of 1999 using a fast repetition rate fluorometer. Concentrations of total dissolvable iron (TD‐Fe) were also determined at each sampling station. The maximum value (0.61) of F v /F m was observed off the Aleutian Peninsula, where TD‐Fe concentrations were r
Abstract. Marine diazotrophs convert dinitrogen (N2) gas into bioavailable nitrogen (N), supporting life in the global ocean. In 2012, the first version of the global oceanic diazotroph database (version 1) was published. Here, we present an updated version of the database (version 2), significantly increasing the number of in situ diazotrophic measurements from 13 565 to 55 286. Data points for N2 fixation rates, diazotrophic cell abundance, and nifH gene copy abundance have increased by 184 %,
In a conventional inductive rf discharge, the electrostatic coupling from the coil to the plasma causes a serous problem of sputtering of any dielectric materials in the vicinity of the coil. This paper reports the suppression of the electrostatic coupling by terminating the coil (inductance L ) with a capacitor (capacitance C ). The suppression resonantly takes place when the termination reactance (1/C ) coincides with a half of the coil reactance (L ). In this condition, the plasma density is
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplication of substituent-controlled oxidative coupling of glycals in a synthesis and structural corroboration of ciclamycin 0: new possibilities for the construction of hybrid anthracyclinesKoji Suzuki, Gary A. Sulikowski, Richard W. Friesen, and Samuel J. DanishefskyCite this: J. Am. Chem. Soc. 1990, 112, 24, 8895–8902Publication Date (Print):November 1, 1990Publication History Published online1 May 2002Published inissue 1 November 1990https://pubs.
A 300 MIPS/W RISC core processor with variable supply-voltage (VS) scheme in variable threshold-voltage CMOS (VTCMOS) is presented. Performance in MIPS/W can be improved by a factor of more than two with no modification in the RISC core except for substrate contacts for the VTCMOS. From a 3.3 V external power supply the VS scheme automatically generates minimum internal supply voltages which meet the demand on its operation frequency.
Abstract Biological nitrogen fixation is increasingly recognized as an important source of new nitrogen in a warming ocean. However, the basin‐scale spatiotemporal distribution of nitrogen‐fixing organisms (diazotrophs) in the ocean and its controlling environmental factors remain unclear. Here we examined the basin‐scale seasonal distribution patterns of major diazotrophs (filamentous cyanobacterial Trichodesmium , unicellular cyanobacterial UCYN‐A1, and proteobacterial Gamma‐A) in surface wate
Abstract. The Kuroshio Current has been thought to be biologically unproductive because of its oligotrophic conditions and low plankton standing stocks. Even though vulnerable life stages of major foraging fishes risk being entrapped by frontal eddies and meanders and encountering low food availability, they have life cycle strategies that include growing and recruiting around the Kuroshio Current. Here we report that phytoplankton growth and consumption by microzooplankton are stimulated by tur
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