Naoshi Hirai

上級研究員(研究院講師)

  • 758 Citations
  • 14 h-Index
1993 …2020

Research output per year

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Research Output

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2019

Spatial resolution of a cable fault location attempt by frequency domain reflectometry

Ohki, Y. & Hirai, N., 2019, p. 845-851. 7 p.

Research output: Contribution to conferencePaper

2012

Improvement of inspection and maintenance procedures of polymeric cable insulation used in nuclear power plants in Japan

Ohki, Y., Hirai, N., Yamamoto, T., Minakawa, T. & Okamoto, T., 2012 Dec 1.

Research output: Contribution to conferencePaper

2010

Endurance of polymeric insulating materials in nuclear power plants and needs for condition monitoring of electric cables

Ohki, Y., Hirai, N., Yamamoto, T., Seguchi, T., Kudoh, H. & Okamoto, T., 2010 Dec 1.

Research output: Contribution to conferencePaper

9 Citations (Scopus)

Experimental research on the feasibility of biodegradable polymeric insulating materials

Ohki, Y., Hirai, N., Kaneko, S. & Okabe, S., 2010 Dec 1.

Research output: Contribution to conferencePaper

2008

Effects of blending various biodegradable polymer plasticizers on the conduction current and AC breakdown strength in starch ester

Nemoto, Y., Kato, F., Hirai, N., Ohki, Y., Kaneko, S. & Okabe, S., 2008 Dec 31, p. 542-545. 4 p.

Research output: Contribution to conferencePaper

5 Citations (Scopus)
2005

Dipolar polarization and depolarization currents in biodegradable polymers

Maeno, Y., Kino, H., Omori, S., Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005 Oct 10, p. 417-420. 4 p.

Research output: Contribution to conferencePaper

4 Citations (Scopus)

Effects of glass transition on the dielectric breakdown and electrical conduction in several biodegradable polymers

Matsushita, M., Maeno, Y., Kino, H., Fujita, S., Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005, p. 413-416. 4 p.

Research output: Contribution to conferencePaper

12 Citations (Scopus)

Effects of ultraviolet photon irradiation on the space charge accumulation properties of several biodegradable polymers

Yamaguchi, Y., Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005 Oct 7, p. 421-424. 4 p.

Research output: Contribution to conferencePaper

4 Citations (Scopus)

Effects of water temperature on degradation of several biodegradable polymers immersed in water

Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005 Oct 7, p. 771-774. 4 p.

Research output: Contribution to conferencePaper

6 Citations (Scopus)
2003

Effect of crosslinking on space charge formation in crosslinked polyethylene

Hirai, N., Maeno, Y., Tanaka, T., Ohki, Y., Okashita, M. & Maeno, T., 2003 Oct 20, p. 917-920. 4 p.

Research output: Contribution to conferencePaper

11 Citations (Scopus)
2002

Interpretation of the relation between residual charge and water trees in XLPE cables

Hirai, N., Ohki, Y., Takeda, T. & Okamoto, T., 2002 Dec 1, p. 1094-1099. 6 p.

Research output: Contribution to conferencePaper

4 Citations (Scopus)
2001

Effect of blending on the dielectric breakdown of polyethylene

Ono, H., Hirai, N. & Ohki, Y., 2001 Dec 1, p. 574-577. 4 p.

Research output: Contribution to conferencePaper

1 Citation (Scopus)

Effects of byproducts of dicumyl peroxide on space charge formation in polyethylene

Hirai, N., Minami, R., Ohki, Y., Okashita, M. & Maeno, T., 2001 Jan 1, p. 450-455. 6 p.

Research output: Contribution to conferencePaper

15 Citations (Scopus)

Effects of liquid chemicals on space charge evolution in low-density polyethylene

Minami, R., Hirai, N., Ohki, Y., Okashita, M. & Maeno, T., 2001 Dec 1, p. 87-90. 4 p.

Research output: Contribution to conferencePaper

7 Citations (Scopus)

On the mechanism of recovery voltage in a dielectric solid proposal of a simple equation

Yamaguchi, A., Hirai, N. & Ohki, Y., 2001 Dec 1, p. 67-70. 4 p.

Research output: Contribution to conferencePaper

Photoluminescence in polymeric insulating materials (low density polyethylene and polypropylene) induced by ultraviolet photons

Ito, T., Toyoda, T., Hirai, N. & Ohki, Y., 2001 Jan 1, p. 319-323. 5 p.

Research output: Contribution to conferencePaper

1 Citation (Scopus)
1999

Effect of contaminant in breakdown time lag of uniform electric field using impulse breakdown in mineral oil

Hirai, N., Akumu, A. O. & Arii, K., 1999 Dec 1, p. 207-210. 4 p.

Research output: Contribution to conferencePaper

1 Citation (Scopus)