KOSEN

Science and Technology Division
National institute of Technology, Okinawa College

National Institute of Technology

Computer Network and Security
Name

Yasutoshi Arata

StatusTechnical Staff

E-mailarata@okinawa-ct.ac.jp

Affiliations
Keywords

Information processing,computer network

TechnicalSupport Skills

・ Network construction
・ Windows Products Activation
・ Server Virtualization

Research Contents

Virtual Server

Available Facilities and Equipment

Main Switch

Making the parts using the CNC Machine
Name

Yukimasa Omine

StatusTechnical Staff

E-mailAffiliations
Keywords
Technical
Support Skills

CNC Machining , CAD , CAM
・ Machine work
・ CAD and CAM

Research Contents
Trial manufacture

Available Facilities and Equipment
CNC Milling (MAKINO KE-55)
Machining center (MAZAK VARIAXIS 500-5Ｘ)
CNC Turning (DMG MORI NL2500)

omine@okinawa-ct.ac.jp

Science and Technology Division
National Institute of Technology, Okinawa College

Generation of Underwater Shock Wave using
High voltage electrical discharge
Name

Osamu HigaStatus

Ph. D.

Affiliations

IEEJ (The Institute of Electrical Engineers of Japan)

Electric discharge, Underwater shock wave, Pulse power, Food processing

TechnicalSupport Skills・・・

Application of instantaneous high pressure by underwater shock wave
Design and trial production of high voltage circuit
Visualization of fluid using high-speed camera

Generation of underwater shock waves using high voltage electrical discharge and its application

We are researching applications of underwater shock wave generated by high-voltage
underwater discharges to agriculture, forestry, and fishery resources.
We are researching discharge characteristics generated shock waves effectively andapplied it to the development of shock wave devices.

We are developing generation techniques of shock wave
by electric discharge (Fig 1).
Generated the shock wave by spark discharge and wire explosion
on underwater electrodeThe faster the expansion of electric discharge or wire explosion,
the stronger the shock wave that can be generated.
We are measuring and evaluating the discharge characteristic andpropagation of the shockwave.
Measure discharge characteristics and shock wave intensityand feedback to equipment development (Fig. 2)
Shock wave phenomenon is evaluated by visualizing using
a high-speed camera (Fig. 3)⇒ Instantaneous high power and high pressure can be used
We are researching for practical application of instantaneous
high-pressure to agriculture, forestry, and fishery resources.
Can be expected to processing effects thatcannot be obtained with standard methods
Researched application to various objects
1. Spall processing of lacquer tree forraw lacquer extraction
2. Processing to YUZU citrus to improveextraction of aroma oils (Fig. 4)
Fig. 4 Processing device for3. Leaf milling for essential oil extraction
YUZU citrus
4. Crush processing of rice with non-heating

Charging Voltage ～4.0kV
Charging Energy ～6.4kJ

High Voltage
Pulse Generator

Voltage [kV]・osamu@okinawa-ct.ac.jp

Keywords

Research Contents

・E-mailTime [us]Water
Al wireO.D. =0.8-1.2mm
Length= 8-15mm

Explosion Pressure⇒ Shock wave
Pressure Vessel

Fig.1 Generate of shock wave using
electric discharge

Fig.2 Discharge waveform and pressure

Fig. 3 Visualization of underwater shockwaves

Available Facilities and Equipment
Portable Shock wave generator （1J, 30kV, 10pulse/sec, Self-developed）
Marxtype shock wave generator（ 4.9kJ,14kV,12pulse/min,Self-developed）

High speed video camera Kirana 5M (5Mfps)
Optical system (Self-developed)

Capacitors bank type shock wave generator （4.9kJ, 3.5kV, 12pulse/min,

Underwater Shock pressure sensor, Measuring instrument for highSelf-developed）

voltage and high current

KOSEN

Science and Technology Division
National Institute of Technology, Okinawa College

National Institute of Technology

Island biology ： Evolutionary Biology andEcology of Plant Mutualisms
Name

Kenta WATANABE

Status

Ph. D.

Affiliations
Keywords
Technical
Support Skills
Research Contents

E-mailkenta-w@okinawa-ct.ac.jp

The Society for the Study of Species Biology, Ecological society ofJapan,
IslandBiology,

EvolutionaryEcology,

ReproductiveBiology,

EnvironmentalEducation, genus Psychotria, Heterostyly
・ Biodiversity analysis, Environmental education, Plant identification
・ Plant documentation such as “Scanography”

Island Biology, Conservation and Environmental Education

Key topics and central questions:
１． Evolutionary ecology of the plant breeding systems and pollination biology on islands
Why is distyly so adaptive? Why is the proportion of dioecism so high on islands compared to continents? Is
breakdown of heterostyly evolutionary dead end? <by using the genus Psychotria (Rubiaceae) as a model system>
２． Plant adaptations to problematic soils; Plant-Fungi symbiosis; Reproductive interference and habitat isolation
What caused the different plant species composition between limestone and non-limestone forests in the Ryukyu
Islands?
３． Seed dispersal mutualisms on islands
Who are the essential seed dispersal agents in the Ryukyu and Bonin Islands?
４． Metadata analysis of island biota
Can we use the Japanese Islands as a model system for “Island Biology”?
５． Conservation biology of the marine systems in the Ryukyu islands and environmental education
What can we learn from a local marine system (Oura Bay)?
６． Floral scent analysis and genetic diversity
How floral scent differs between individual plants, and what does it mean ecologically?

Available Facilities and Equipment
Scanning electron microscopy （SEM）

Fluorescence microscopy

KOSEN

Science and Technology Division
National Institute of Technology, Okinawa CollegeNational Institute of Technology

Study of the heat resistance
NameKenta Gibo

E-mailStatus

Technical Staff

gibo@okinawa-ct.ac.jp

Affiliations
Keywords

Thermal analysis of the heat-resistant material, Numerical simulation

TechnicalSupport Skills

Thermal design of heat-resistant material

Research Contents
Numerical simulation of thermal response of the heat-resistant material
Re-entry capsule to bring back equipment to Earth from a space is exposed to severe heating environmentby aerodynamic heating during re-entry. CFRP ablator are used as thermal protection materials to protect
against high heat environment inside the capsule. In order to design the ablator, it is necessary to predict
the thermal behavior. This thermal analysis technology is effective not only for the special environment of
the atmospheric re-entry, but also in the design of heat-resistant material in general.
Table１ Test conditions

Length of ablator : t 1
Length of insulation : t 2

20mm
20mm

qcw

Copper interface

34mm

Insulation

Test modelDiameter : d2Ablator(CFRP)

0.98MW/m
60sd

Heating rate : q cw
Heating time : T hｔ2ｔ1Heat condition

back sideSurface

Fig.１ Outline drawing of test model
700
Backside Temperature [K]Surface Temperature [K]

2500
2000
1500
Measured1000

Calculated
500001020304050

Time from the beginning of heating [sec]

60600
500
400

Measured
Calculated

300
200
0100

200

300

400500600Time from the beginning of heating [sec](a)Comparison of surface temperature(ｂ）Comparison of back side temperature
Fig.2 The comparison between the measured and calculated values
Available Facilities and Equipment

所属： 沖縄工業高等専門学校 技術室
研究タイトル：

落雷学習教材の開発
氏名：

白石博伸 ／ SHIRAISHI Hironobu

E-mail：h-shira@okinawa-ct.ac.jp

職名：

技術職員

学位：

学士（理学）

所属学会・協会：
キーワード：

電気回路、電子回路、高電圧、教材開発
・電気，電子回路・教材開発

技術相談
提供可能技術：研究内容：
雷の発生とその性質を学ぶ教材の開発
落雷から身を守るための対策を解説する教材開発

落雷デモ装置落雷のデモンストレーション

提供可能な設備・機器：
名称・型番（メーカー）

KOSEN

Science and Technology Division
National Institute of Technology, Okinawa College

National Institute of Technology

Development of learning materials on lightning
Name

Hironobu SHIRAISHI

StatusTechnical Staff

E-mailh-shira@okinawa-ct.ac.jp

Affiliations
Keywords

Electric circuit, High voltage, Development of Teaching Materials

Technical
Support Skills

・ Electric circuit・ Development of Learning Materials

Research Contents

Lightning Generator

Available Facilities and Equipment

Demonstration of lightning strike