Hitachi, Ltd.

Haruo Fujimori

Takehiko Kitamori

Fuminobu Takahashi

Shunsuke Uchida

Izumi Yamada

Kazumichi Suzuki

Takaharu Fukuzaki

Masanori Sakai

Yuichi Ishikawa

Tetsuya Matsui

Makoto Nagase

Shigeru Izumi

Masahiro Koike

Yasushi Nomura

Hideo Yusa

Takuya Takahashi

Takashi Nishi

Noriyuki Ohnaka

Tetsuo Fukasawa

Kenji Yokose

Taiko Ajiro

Kazuo Yasuda

Akira Sasahira

Yoshihiro Ozawa

Yusuke Isobe

The composition of an alloy is inhomogeneous, so that the Fermi level of electrons in the surface of the alloy differs depending upon positions. It is accordingly considered that a part susceptible to corrosion and a part less susceptible thereto will coexist in the alloy. The corrosion rate of the alloy is indicated as the exponential function of a potential difference (.DELTA..PHI..sub.H) within an electric double layer. The potential difference remains unchanged as long as the Fermi level lies within the forbidden band of the electrons. However, in a range in which the Fermi level falls within the valence band of the electrons, the lowering thereof leads to the increase of the potential difference. Accordingly, a corrosion-resisting alloy is designed in accordance with the following guidelines: a) The electron energy level (Ev) of the valence band is low, b) an oxide film to be formed on the alloy is an n-type semiconductor, c) a band gap (Ec-Ev) is wide where Ec denotes the conduction band of the electrons, and d) a flatband potential (E.sub.f1) is low. Further, the operation of a plant and the evaluation of a corrosional damage can be based on such a theory.

Method of evaluating corrosion resistance of metal material, method of

Plant operating conditions 1, apparatus operating conditions 2 and environment conditions 3 are accumulated, combined and put together as a set of plant status variables 8 through a monitor 6, while water chemistry information 4 is accumulated as another set of plant status variables 9. The set of status variables 8 is updated and the past data are accumulated in the set of status variables 9. Periodical inspection data 5 are also accumulated in the set of status variables 9 along with the water chemistry information 4. The set 9 is compressed and stored as a plant chart 11 such as a personal clinical chart. A status variable prediction 12 is performed in consideration of the personality of a plant. Both data of the sets 8 and 10 are compared with each other by comparison means 13. If both the data nearly coincide with each other, the plant is diagnosed to the normal and, if not, it is diagnosed to be abnormal. When the plant is diagnosed to abnormal, an abnormal apparatus and an abnormal factor are identified.

Plant monitoring and diagnosing method and system, as well as plant

A diagnosis system having sensors for supervising a plant, signal processors for processing signals of the sensors, and a state quantity arithmetic operation unit. The state quantity arithmetic operation unit calculates a quantity of state expressing the environment of the plant on the basis of supervisory information inputted through the signal processors. A state quantity prediction unit predictively calculates a quantity of state after a predetermined time on the basis of the quantity of state, supervisory information and a time change of the quantity of state inputted through the state quantity arithmetic operation unit. A future event prediction unit predicts a future event on the basis of predicted information of the quantity of state inputted through the state quantity prediction unit. An image information processor converts the quantity of state given by the state quantity arithmetic operation unit into image information and indicates the image information on a display unit. An image information processor converts the predicted quantity of state after the predetermined time, given by the state quantity prediction unit, into image information and indicates the image information on a display unit. An image information processor converts the future event predicted by the future event prediction unit into image information and indicates the image information on a display unit.

Diagnosis system

Plant operating conditions 1, apparatus operating conditions 2 and environment conditions 3 are accumulated, combined and put together as a set of plant status variables 8 -through a monitor 6, while water chemistry information 4 is accumulated as another set of plant status variables 9. The set of status variables 8 is updated and the past data are accumulated in the set of status variables 9. Periodical inspection data 5 are also accumulated in the set of status variables 9 along with the water chemistry information 4. The set 9 is compressed and stored as a plant chart 11 such as a personal clinical chart. A status variable prediction 12 is performed in consideration of the personality of a plant. Both data of the sets 8 and 10 are compared with each other by comparison means 13. If both the data nearly coincide with each other, the plant is diagnosed to be normal and, if not, it is diagnosed to be abnormal. When the plant is diagnosed to be abnormal, an abnormal apparatus and an abnormal factor are identified.

An apparatus and a method for analysis of a particle by irradiation of the particle in a fluid with an intense laser pulse to cause laser breakdown and to detect sonic waves or plasma emission which are generated by the laser breakdown. The size of the particle is measured by using at least two kinds of information from the following: intensity of plasma emission or sonic wave generated by the laser breakdown, location of the laser breakdown plasma, and plasma emission waveform. Also, a laser pulse having flattened distribution of intensity for the irradiation is used in order to eliminate the dependence of the measured value on the particle location.

Apparatus for analysis of particulate material, analytical method for

By use of an excitation beam having a wavelength which is equal to, or close to, the sizes of particular particulate substances as the object of analysis, the particulate substances such as an immunoreaction product between an antigen and an antibody or between the antigen and a material supporting the antibody thereon are detected selectively. Very small particles having specific sizes such as rheumatuid factors, cancer specific antigens can be detected with high sensitivity.

Method and apparatus for detecting particular particulate substance

A method of and an apparatus for simultaneous determination of constituents are disclosed in which a solution containing trace constituents is irradiated with an intensity-modulated electromagnetic wave having a predetermined wavelength, a photoacoustic signal and radiation from the electromagnetic-wave irradiation trace constituents are detected together with the emission spectrum thereof. The concentrations of the trace constituents are calculated from the magnitude of the photoacoustic signal, the intensity of the radiation, and calibration curves each formed for known concentrations of one of the trace constituents, and the trace constituents are identified by the above emission spectrum.

Method of and apparatus for simultaneous determination

A dissolved substance contained in a solution is oxidized or reduced by adding a particulate semiconductor photocatalyst and a water-soluble electron acceptor or donor for the particulate semiconductor photocatalyst to a solution containing a dissolved substance, and irradiating the particulate semiconductor photocatalyst in the solution with an electromagnetic wave having an energy high enough to excite the particulate semiconductor photocatalyst, or by adding a particulate semiconductor photocatalyst and a water-soluble electron acceptor or donor for the particulate semiconductor photocatalyst to a solution containing a dissolved substance and irradiating the particulate semiconductor photocatalyst in the solution with an electromagnetic wave having an energy high enough to excite the particulate semiconductor photocatalyst and having a wavelength outside the absorption wavelength region of a precursor substance capable of producing an oxidation or reduction reaction-inhibiting substance, whereby (1) ions or complexes are converted to simple substances or to ions or compounds with different valencies, and (2) simple substances, ions, complexes or other compounds are separated and recovered or removed by utilizing its actions and effects.

Process and apparatus for oxidizing or reducing dissolved substance

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Hitachi, Japan

Haruo Fujimori