Koichi Watanabe
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View article: Peroxide concentrations measured over a rural site in the Hokuriku district, coastal region of the Sea of Japan, central Japan, during early summer using a helicopter
Peroxide concentrations measured over a rural site in the Hokuriku district, coastal region of the Sea of Japan, central Japan, during early summer using a helicopter Open
Atmospheric concentrations of peroxides (hydrogen peroxide (H 2 O 2 ) and methyl hydroperoxide (MHP)), formaldehyde (HCHO), ozone (O 3 ), and sulfur dioxide (SO 2 ) were measured using a helicopter over Imizu City, Toyama Prefecture, centr…
View article: Deep Learning Approaches for Power Prediction in Wind–Solar Tower Systems
Deep Learning Approaches for Power Prediction in Wind–Solar Tower Systems Open
Wind–solar towers are a relatively new method of capturing renewable energy from solar and wind power. Solar radiation is collected and heated air is forced to move through the tower. The thermal updraft propels a wind turbine to generate …
View article: Power Output Enhancement of Straight-Bladed Vertical-Axis Wind Turbines with Surrounding Structures
Power Output Enhancement of Straight-Bladed Vertical-Axis Wind Turbines with Surrounding Structures Open
Wind tunnel experiments were conducted by installing wind-acceleration structures on both sides of a straight-bladed vertical-axis wind turbine (VAWT) to improve the output performance of the turbine. In the case of Venturi-shape structure…
View article: Long-range transport of airborne microorganisms by Asian dust events: Bioaerosols relating to human health
Long-range transport of airborne microorganisms by Asian dust events: Bioaerosols relating to human health Open
The bioaerosols relating to human health are possibly transported by the westerly wind traveling at high altitudes over East Asia. However, the long-range transport of bioaerosols has not been demonstrated by analyzing the microbial commun…
View article: CYCLIC TENSION−COMPRESSION LOADING TESTS AND ANALYSES OF PIN-ENDED ISOLATED BRACING MEMBERS
CYCLIC TENSION−COMPRESSION LOADING TESTS AND ANALYSES OF PIN-ENDED ISOLATED BRACING MEMBERS Open
2種類のCT形鋼断面の両端ピン支持単一ブレース材11体を用いて,正負交番の繰り返し中心軸および偏心軸載荷実験ならびに解析を行った.主要な検証項目は,(1)細長比の大きいブレース材に対する初期横荷重法の適用性,(2)部材座屈と局部座屈の連成座屈に対するひずみ照査法の適用性である.(1)に関する実験は,両端のクレビスの回転摩擦の影響が大きく,履歴曲線は,回転摩擦が切れるまでは両端固定の解析,回転摩擦が切れた後は両端回転自由の解析結果に概ね一致した.回転摩擦が切れるのは,部材座屈…
View article: Complex Modal Analysis for Generally Viscous and Visco-elastic Damped Vibratory System
Complex Modal Analysis for Generally Viscous and Visco-elastic Damped Vibratory System Open
We examined a complex modal analysis of generally viscous and visco-elastic damped vibratory system, which include viscous damping proportional to the velocity of the masses and viscoelastic damping proportional to the force of the linear …
View article: Continuous Measurements of Microbial Particles in Central Japan Using a Real Time Viable Particle Counter
Continuous Measurements of Microbial Particles in Central Japan Using a Real Time Viable Particle Counter Open
The number concentrations of microbial (counted as viable) particles and size-separated particles were measured continuously in Imizu City, Toyama, in the coastal region of the Sea of Japan, in 2015 using a commercial real time viable part…
View article: A Simple Theory and Performance Prediction for a Shrouded Wind Turbine with a Brimmed Diffuser
A Simple Theory and Performance Prediction for a Shrouded Wind Turbine with a Brimmed Diffuser Open
We developed a new wind turbine system that consists of a diffuser shroud with a broad-ring brim at the exit periphery and a wind turbine inside it. The shrouded wind turbine with a brimmed diffuser, which we called a “wind lens turbine” (…
View article: Machine learning approaches for thermal updraft prediction in wind solar tower systems
Machine learning approaches for thermal updraft prediction in wind solar tower systems Open
Wind solar towers constitute a fairly new scheme for harvesting renewable energy from solar and wind energy sources. In such a tower, solar radiation is collected and hot air is enforced to go fast through the tower, a process called therm…
View article: Validation Study of Multi-Rotor Systems Using Two Shrouded Wind Turbines
Validation Study of Multi-Rotor Systems Using Two Shrouded Wind Turbines Open
Multi rotor systems (MRS) have shown a great potential as a future application of wind energy. In this study, the aim is simulating the aerodynamic performance of a an MRS using fully-resolved shrouded wind turbine blades then validating w…
View article: An Ignored Wind Generates More Electricity: A Solar Updraft Tower to a Wind Solar Tower
An Ignored Wind Generates More Electricity: A Solar Updraft Tower to a Wind Solar Tower Open
A solar updraft tower is one of the wind power generation plants which utilizes solar energy. The purpose of this study was to ascertain whether the tower was also able to utilize crosswind energy. Wind tunnel experiments and numerical sim…
View article: Study on Wake Interaction of Two Wind Turbines
Study on Wake Interaction of Two Wind Turbines Open
In order to design a large-scale wind farm, it is highly important to understand the wake of multiple wind turbines. Wind tunnel experiments with two arrangement patterns were conducted to approach the interference of the wakes arranging t…
View article: Various Arrangements for Diffuser-Augmented Wind Turbines Used in a Multi-Rotor System
Various Arrangements for Diffuser-Augmented Wind Turbines Used in a Multi-Rotor System Open
Kyushu University has developed a unique wind turbine called wind lens turbine (WLT) which consists of a diffuser with a brim around the wind turbine.The purpose of a WLT is to increase the performance of a conventional wind turbine by gen…
View article: Power Output Enhancement of a Ducted Wind Turbine by Stabilizing Vortices around the Duct
Power Output Enhancement of a Ducted Wind Turbine by Stabilizing Vortices around the Duct Open
A brimmed-diffuser augmented turbine (called a wind lens turbine: WLT) actively uses vortices around the brim to enhance its power output. However, the vortices are usually unstable and asymmetric. This study attempted to stabilize the vor…
View article: Multirotor Systems Using Three Shrouded Wind Turbines for Power Output Increase
Multirotor Systems Using Three Shrouded Wind Turbines for Power Output Increase Open
Brimmed-diffuser augmented wind turbines (B-DAWTs) can significantly increase the performance of the rotor. Multirotor systems (MRSs) have a lot of merits such as significant saving mass and overall cost of the wind turbine system. In the …
View article: A New Approach Toward Power Output Enhancement Using Multirotor Systems With Shrouded Wind Turbines
A New Approach Toward Power Output Enhancement Using Multirotor Systems With Shrouded Wind Turbines Open
A multirotor system (MRS) is defined as containing more than one rotor in a single structure. MRSs have a great potential as a wind turbine system, saving mass and cost, and showing scale ability. The shrouded wind turbine with brimmed dif…
View article: Long-range transported bioaerosols captured in snow cover on Mount Tateyama, Japan: Impacts of Asian-dust events on airborne bacterial dynamics relating to ice-nucleation activities
Long-range transported bioaerosols captured in snow cover on Mount Tateyama, Japan: Impacts of Asian-dust events on airborne bacterial dynamics relating to ice-nucleation activities Open
The westerly wind travelling at high altitudes over East Asia transports aerosols from the Asian deserts and urban areas to downwind areas such as Japan. These long-range transported aerosols include not only mineral particles, but also mi…
View article: Numerical Prediction and Field Verification Test of Wind-Power Generation Potential in Nearshore Area Using a Moored Floating Platform
Numerical Prediction and Field Verification Test of Wind-Power Generation Potential in Nearshore Area Using a Moored Floating Platform Open
The offshore turbine system was installed on a floating platform moored in Hakata Bay, offshore of Fukuoka, Japan. An identical turbine system was also installed at the adjacent waterfront. The separation of the two turbines was 3.7 km. Wi…
View article: Wind lens technology and its application to wind and water turbine and beyond
Wind lens technology and its application to wind and water turbine and beyond Open
Wind lens is a new type of wind power system consisting of a simple brimmed ring structure that surrounds the rotor causing greater wind to pass through the turbine. As a consequence, the turbine's efficiency of capturing energy from the w…
View article: Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft
Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft Open
A new type of solar tower was developed through laboratory experiments and numerical analyses. The solar tower mainly consists of three components. The transparent collector area is an aboveground glass roof, with increasing height toward …
View article: Application of a Diffuser Structure to Vertical-Axis Wind Turbines
Application of a Diffuser Structure to Vertical-Axis Wind Turbines Open
The effects of using a wind acceleration device (wind lens) with vertical-axis wind turbines in wind tunnel experiments were examined. A wind lens consists of a diffuser and flanges, and this study investigated the optimum parameters of th…
View article: Ratios of Mg<sup>2+</sup>/Na<sup>+</sup> in the snow cover at Murododaira, Mt. Tateyama, Japan: On the possibility of an indicator of chemical leaching
Ratios of Mg<sup>2+</sup>/Na<sup>+</sup> in the snow cover at Murododaira, Mt. Tateyama, Japan: On the possibility of an indicator of chemical leaching Open
Measurements of the concentrations of major ions in the snow pits at Murododaira (altitude, 2,450m), Mt. Tateyama, near the coast of the Japan Sea in Central Japan, have been taken each April. Snowmelt usually occurs after May near the sum…
View article: High Operation Capable Marine Dual Fuel Engine with LNG
High Operation Capable Marine Dual Fuel Engine with LNG Open
Niigata Power Systems has been developing the gas engine for about 30 years as one of the best matched products which satisfies the trend of social requirements, such as an environmental preservation and fuel economy, and an electrical dem…