Osaka University

Shimadzu Corporation

Other

Nissan Chemical Industries Limited

Yoshida Creation Inc.

Technology Research Institute of Osaka Prefecture

Katsuhisa Kitano

Kei Shinada

Satoshi Hamaguchi

Satoshi Ikawa

Takahiro Nishimoto

Shigeyoshi Horiike

Satoshi Matsuoka

Michizo Yamanaka

Yoichi Nakashima

Atsushi Tani

Tsuneo Kawahara

Hironori Aoki

A light source emits excitation light to discharge gas that flows through a dielectric tube. A ground electrode unit includes a first ground electrode and a second ground electrode arranged at a distance from each other in an axial direction of the dielectric tube. A high-voltage electrode is provided between the first ground electrode and the second ground electrode. A first distance between the first ground electrode and the high-voltage electrode is shorter than a second distance between the second ground electrode and the high-voltage electrode. A cover is provided on an outer wall of the dielectric tube at a position between the first ground electrode and the high-voltage electrode. The light source is arranged to emit excitation light such that an optical axis thereof is directed toward a position where the cover is not provided on the outer wall of the dielectric tube.

Dielectric barrier discharge ionization detector and gas chromatography analyzer

A BID includes: a discharger () including a dielectric pipe () and a pair of electrodes () attached on an outer wall of the dielectric pipe, the pair of electrodes () being arranged at a distance from each other in a direction along a central axis of the dielectric pipe (), the discharger () being arranged so that plasma generating gas is introduced from a first end of the dielectric pipe () and configured to generates dielectric barrier discharge inside the dielectric pipe () to generate plasma; a detection section () including a sample gas introduction section () and a collection electrode () for collecting ions, the detection section () being configured to ionize components in the sample gas using light emitted from the plasma generated in the discharger () and to detect the generated ions by collecting them using the collection electrode (); and a voltage supply (') for generating a potential difference between the pair of electrodes ().

Dielectric barrier discharge ionization detector

A dielectric barrier discharge ionization detector capable of achieving a high signal-to-noise ratio is provided. The detector includes: a discharging section for generating plasma from argon-containing gas by electric discharge; and a charge-collecting section for ionizing a component in a sample gas by an effect of the plasma and for detecting ion current formed by the ionized component. The discharging section includes a cylindrical dielectric tube having a high-voltage electrode connected to AC power source as well as upstream-side and downstream-side ground electrodes and formed on its outer circumferential wall. A semiconductor film is formed on the inner circumferential surface of the tube. The upstream-side and downstream-side ground electrodes are respectively made longer than the initiation distances for a creeping discharge between the high-voltage electrode and a tube-line tip member as well as between the high-voltage electrode and the charge-collecting section.

A sterilization method is provided which acquires microbicidal activity equivalent to plasma-treated solution or more powerful than the same without the use of a plasma generation device. The sterilization method includes applying liquid containing peroxynitric acid (HOONO) produced by chemical reaction to an object to be sterilized under acidic conditions of a pH value of 4.8 or lower. The liquid containing the peroxynitric acid is produced by mixing nitrous acid and peroxide together, for example, mixing nitrite and peroxide together.

Sterilization method, formulation for sterilization use, and device for producing sterilizing liquid

The dielectric barrier discharge ionization detector includes: a dielectric tube through which a plasma generation gas is passed; a high-voltage electrode formed on the outer wall of the dielectric tube; two ground electrodes and formed on the outer wall of the dielectric tube, with the high-voltage electrode in between; a voltage supplier for applying AC voltage between the high-voltage electrode and each ground electrode to generate electric discharge within the dielectric tube and thereby generate plasma from the plasma generation gas; and a charge-collecting section for detecting an ion current formed by ionized sample-component gas produced by the plasma. The distance between one ground electrode and the high-voltage electrode is longer than a discharge initiation distance between these two electrodes, while the distance between the other ground electrode and the high-voltage electrode is shorter than the discharge initiation distance between these two electrodes.

A hydrogenation method according to the present invention includes preparing a plasma generation section (), preparing a hermetic member (), disposing an amorphous silicon film (S) inside the hermetic member (), and performing plasma treatment on the amorphous silicon film (S) in a manner that the plasma generation section () allows a gas at a pressure around an atmospheric pressure containing a hydrogen gas to generate plasma in at least a partial region inside the hermetic member (). Suitably, the disposing an amorphous silicon film (S) includes forming the amorphous silicon film (S) inside the hermetic member () with the use of a solution in which a silane compound is dissolved.

Hydrogenation method and hydrogenation apparatus

An object of the present invention is to efficiently sterilize microorganisms present in or on a surface of a liquid. Plasma is generated in a vicinity of or in a manner to make contact with a liquid whose pH value is adjusted to become 4.8 or lower, more preferably 4.5 or lower. The plasma is generated in an atmospheric gas containing nitrogen, e.g., in the air. Superoxide anion radicals (O.) that are generated by the plasma react with protons (H) in the liquid to form hydroperoxy radicals (HOO.). Further, nitrogen and oxygen included in the air are combined together by the action of plasma to form nitrogen oxide such as nitric oxide (NO.). The nitric oxide (NO.) combines with the hydroperoxy radicals (HOO.) to become peroxynitrite (ONOOH(ONOO)) having a high microbiocidal activity.

Sterilization method and apparatus

A technique for reducing an electromagnetic noise entering an electrode or a drift of a signal due to a fluctuation in the ambient temperature is provided to improve the S/N ratio of a signal originating from a component of interest. A dummy electrode having the same structure as an ion-collecting electrode is provided within a lower gas passage at a position where dilution gas with no sample gas mixed therein flows. A differential amplifier is provided to perform differential detection between output A of a current amplifier connected to the ion-collecting electrode and output B of a current amplifier connected to the dummy electrode. The differential signal is free from a common mode noise or drift and hence accurately reflects the amount of the component of interest.

Discharge ionization current detector

A discharge ionization current detector using a low-frequency dielectric barrier discharge with an improved S/N ratio is provided. A current detectoris disposed between an excitation high-voltage power sourceand a discharge electrodeto detect a discharge current flowing in pulses due to plasma generation. The detection signal of the current detectorand an output signal from a current amplifierfor amplifying an ion current are inputted into an output extraction unit. The output extraction unitdetects a precipitous-rise portion of the discharge current detection signal and generates a trigger signal, and then extracts an ion current signal for a predetermined time period from the trigger signal. This can remove an influence of a noise appearing in a signal during a time period where no plasma emission is generated, thereby improving the S/N ratio of the detection signal.

A dental clinical apparatus having a function which conventional instruments for dental treatment have not had and having a novel constitution. The dental clinical apparatus includes a syringe which has a fluid jetting system for dental treatment and a plasma jet applying means for producing a plasma jet from the end by allowing a low-frequency high-voltage power supply to apply a low-frequency high voltage between electrodes on the outer peripheral surface of a rare gas tube through which a rare gas having a low dielectric breakdown voltage under the atmospheric pressure is flowed, and thereby causing electrical discharge.

Dental clinical apparatus and plasma jet applying device for dentistry

A low-frequency high AC voltage from an excitation voltage power source () is applied between one electrode () and two other electrodes (A andB) to generate a low-frequency AC-excited dielectric barrier discharge within a gas passage (), thereby creating atmospheric pressure non-equilibrium micro-plasma. A sample gas is mixed with hydrogen inside the passage of a nozzle (), and further mixed with air outside an exit port () to burn, forming a hydrogen flame (). Then, the sample gas reaches an ionization area (), where the sample components are ionized due to the effect of light emitted from the plasma. Meanwhile, water molecules generated in the hydrogen flame () are supplied into the ionization area (), whereby some of the sample-molecule ions are hydrated while the others undergo a reaction to form a hydroxonium ion. These kinds of hydrated ions have long lifetimes and barely become extinct halfway, so that they can efficiently reach a detection electrode () and be detected as ion current. As a result, the detection sensitivity is improved and the dynamic range is enhanced.

A method and apparatus is provided for efficiently supplying a liquid with ions or radicals generated by plasma and so on, or for effectively sterilizing microorganisms present in a liquid or on the surface thereof. The method includes generating plasma in a gas phase by a plasma generation device, producing ions or radicals in the gas phase by the plasma; electrophoresing the ions or radicals toward the liquid by an electric field applied to the produced ions or radicals; and diffusing the ions or radicals into the liquid. The liquid is adjusted to have a pH value of 4.8 or lower for effective sterilization.

Method and apparatus for supplying liquid with ions, sterilization method and  apparatus

For production of plasma from a medium gas mass in an elongated shape, electric field forming elementsthat form an electric field in the medium gas mass are provided. The electric field forming elements form an electric field so that partial discharge occurs from the electric field forming elements toward both sides in the longitudinal direction of the medium gas mass. Accordingly, plasmais produced from the medium gas mass. The medium gas mass is formed by, for example, gas supply membersthat guide medium gas, through an internal hollow, to the electric field forming elements. An electric field forming area includes, for example, at least one high-potential electrodeand a voltage applying unitthat applies a voltage to the high-potential electrode. Plasma limited in medium gas can be produced with high energy efficiency stably over a wide range of parameters through a simple configuration.

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Ibaraki, Japan

Katsuhisa Kitano