Abstract: An EGR cooler including tubes and a shell enclosing the tubes. Cooling water is supplied into and discharged from the shell. Exhaust gas is guided from a diesel engine into the tubes for thermal exchange of the exhaust gas with the cooling water. A bypass flow path for guiding the cooling water is constituted within the shell so as to prevent stagnation of the cooling water in the shell.

Abstract: The present invention relates to a compound defined by a formula herein, a composition and/or a method relating to one or more of the defined compounds.

Abstract: A near infrared fluorescent contrast agent comprising a compound having three or more sulfonic acid groups in a molecule, and a method of fluorescence imaging comprising introducing the near infrared fluorescent contrast agent of the present invention into a living body, exposing the body to an excitation light, and detecting near infrared fluorescence from the contrast agent. The near infrared fluorescent contrast agent of the present invention is excited by an excitation light and emits near infrared fluorescence. This infrared fluorescence is superior in transmission through biological tissues. Thus, detection of lesions in the deep part of a living body has been made possible. In addition, the inventive contrast agent is superior in water solubility and low toxic, and therefore, it can be used safely.

Abstract: An EGR cooler including tubes and a shell enclosing the tubes. Cooling water is supplied into and discharged from the shell. Exhaust gas is guided from a diesel engine into the tubes for thermal exchange of the exhaust gas with the cooling water. A bypass flow path for guiding the cooling water is constituted within the shell so as to prevent stagnation of the cooling water in the shell.

Abstract: The oxygen concentration detector of the present invention includes a sensor element having a solid electrolyte and having an external electrode and an internal electrode provided on the external surface and the internal surface, respectively, and a heater provided adjacent to the internal surface of the sensor element, in which a high-emissivity layer consisting of a material having a high emissivity is provided on the internal surface of the sensor element and/or the surface of the heater.

Abstract: A near infrared fluorescent contrast agent comprising a compound having three or more sulfonic acid groups in a molecule, and a method of fluorescence imaging comprising introducing the near infrared fluorescent contrast agent of the present invention into a living body, exposing the body to an excitation light, and detecting near infrared fluorescence from the contrast agent. The near infrared fluorescent contrast agent of the present invention is excited by an excitation light and emits near infrared fluorescence. This infrared fluorescence is superior in transmission through biological tissues. Thus, detection of lesions in the deep part of a living body has been made possible. In addition, the inventive contrast agent is superior in water solubility and low toxic, and therefore, it can be used safely.

Abstract: This relates to a contrast medium containing a complex of a gadolinium (Gd) type contrast agent and a polymer. More particularly, the contrast medium wherein the polymer capable of phase transit in response to environmental changes, particularly, pH, light or temperature, to develop a different water solubility, and a method for imaging by the use of this contrast medium. By binding a polymer responsive to microenvironmental changes with a Gd type MRI contrast agent, on-off switching of MRI imaging capability is enabled, wherein imaging occurs only on the target sites. Consequently, a highly specific MRI contrast medium can be obtained, whereby a highly specific MRI diagnosis is made possible, wherein only the target sites such as a tumor and a particular site are imaged and otherwise at the site where imaging is not necessary.

Abstract: A composite gas sensor comprises a pump cell, a NOx sensor cell and an oxygen sensor cell. The NOx sensor cell is connected to a first ammeter and a constant power source to measure the NOx concentration of a sample gas. The pump cell is connected to a second ammeter and a variable power source to measure an air-fuel ratio of the sample gas. The oxygen sensor cell is connected to a voltmeter. A controller adjusts the variable power source to produce a constant value from the voltmeter.

Abstract: A composite gas sensor comprises a pump cell, a NOx sensor cell and an oxygen sensor cell. The NOx sensor cell is connected to a first ammeter and a constant power source to measure the NOx concentration of a sample gas. The pump cell is connected to a second ammeter and a variable power source to measure an air-fuel ratio of the sample gas. The oxygen sensor cell is connected to a voltmeter. A controller adjusts the variable power source to produce a constant value from the voltmeter.

Abstract: An oxygen sensor element includes a solid electrolyte having cavities on a surface thereof and an electrode formed on the surface of the solid electrolyte. In a method of producing the oxygen sensor element, a solution containing a noble metal compound for nucleus formation is first applied to an electrode forming portion of the solid electrolyte to form a coating film. Then, the coating film is heat-treated to form a nucleus forming portion where noble metal nuclei are deposited. Subsequently, metal plating is applied to the nucleus forming portion to form a plating film deeply entering the cavities. Thereafter, the plating film is burned to form the electrode deeply entering the cavities.

Abstract: A method for manufacturing an oxygen sensor unit of the type which includes at least a shaped body of a solid electrolyte, an inner electrode provided on an inside surface of the shaped body and exposed to a reference gas, an outer electrode provided on an outside surface of the shaped body and exposed to a gas to be measured, and a porous protective layer covering the outer electrode and a portion of the shaped body adjoining to said outer electrode wherein the solid electrolyte is made of a mixture of zirconia and a stabilizer therefor and is constituted of a sintered product of partially stabilized zirconia. The method is characterized in that the partially stabilized, sintered zirconia is obtained according to a high temperature sintering process which includes at least the step of sintering the mixture at a temperature of 1200° C.

Abstract: A main body of a NOx sensor has a sensor cell and defines a reference gas chamber and a sample gas chamber therein. The sample gas chamber has a wall formed by a solid electrolytic substrate having an oxygen ion conductivity. The sensor cell is disposed between the reference gas chamber and the sample gas chamber for detecting a concentration of a NOx gas. A pump cell body of the NOx sensor has a surface facing to the sample gas chamber and has a pump cell for introducing and exhausting an oxygen gas to and from the sample gas chamber. In manufacturing this NOx sensor, the main body and the pump cell body are fabricated individually as separate items. The main body and the pump cell body are sintered independently. Then, the main body and the pump cell body are assembled into to the NOx sensor.

Abstract: An air-fuel ratio sensor of a limit current type is used for an air-fuel ratio feedback control. When the air-fuel ratio sensor is in a semi-activated state, the air-fuel ratio sensor is driven into an electromotive force generating mode by a current externally applied thereto thereby to shift an electromotive force changing point so that an air-fuel ratio at which the electromotive force changes stepwisely is shifted from the stoichiometric ratio point to a lean zone. When the air-fuel ratio sensor is in a completely activated state, the air-fuel ratio sensor is applied with a voltage to produce a limit current varying with an air-fuel ratio so that a feedback control is performed based on the advanced control theory by using a linear current output characteristics.

Abstract: A lead wire for a sensor has a conductor unit including at least stainless steel wires and copper wires. By setting the cross-sectional percentage of the stainless steel wires in the conductor unit within the range of 30 to 70%, it is possible to obtain a lead wire having low electrical resistance, and high flexibility, tensile strength and elasticity. There are preferred values in hardness and heat treatment of the stainless steel wires. The copper wires are preferably coated with an antioxidant film. The lead wire may include hybrid wires stranded together and obtained by integrally molding or forming stainless steel and copper. It is preferable that the lead wire is coated with an insulating coating material such as a Teflon type resin.

Abstract: An oxygen sensor element includes a solid electrolyte having cavities on a surface thereof and an electrode formed on the surface of the solid electrolyte. In a method of producing the oxygen sensor element, a solution containing a noble metal compound for nucleus formation is first applied to an electrode forming portion of the solid electrolyte to form a coating film. Then, the coating film is heat-treated to form a nucleus forming portion where noble metal nuclei are deposited. Subsequently, metal plating is applied to the nucleus forming portion to form a plating film deeply entering the cavities. Thereafter, the plating film is burned to form the electrode deeply entering the cavities.

Abstract: An air-fuel ratio sensing element comprises a cup-shaped solid electrolyte with one end opened and the other end closed, an external electrode provided on an outer wall surface of the solid electrolyte so as to be exposed to measured gas, and an internal electrode provided on an inner wall surface of the solid electrolyte in a confronting relationship to the external electrode. A first insulating layer, made of a gas-permeable and nonconductive porous material, is provided on the external electrode at least in a region used for detecting of an air-fuel ratio. A second insulating layer is provided outside the first insulating layer and, a heater layer as provided between the first insulating layer and the second insulating layer.

Abstract: An oxygen concentration sensor having excellent sealing performance between a lead wire and a lead wire insertion hole includes a sensor element disposed insertedly into a housing, protective covers disposed at an end portion of the housing, lead wires inserted into the protective covers, and an elastic insulating member disposed inside the protective covers and having a lead wire insertion hole for inserting the lead wires. The lead wire insertion hole in the elastic insulating member has a rib protruding in the radial direction. The elastic insulating member is caulked and fixed by the protective covers.

Abstract: An oxygen concentration detector has a detecting element comprising a solid electrolyte inserted into a housing and heating means for heating the detecting element, and the outer surface of the detecting element is provided with a surface layer, the contact angle of the surface layer being larger than the contact angle of the outer surface of the detecting element with which the surface layer directly contacts.

Abstract: An air-fuel ratio sensor comprises a platelike oxygen sensing section made of a solid electrolyte and a heater sheet heating the oxygen sensing section. The oxygen sensing section and the heater sheet are stacked via spacers to constitute a multilayer construction. The heater sheet comprises a first platelike insulating sheet chiefly containing at least one component selected from the group consisting of .alpha.-alumina, steatite and mullite, a filmy resistance element disposed on the first insulating sheet and having a resistance-temperature coefficient within a range of 0.5.times.10.sup.3 to 2.0.times.10.sup.3 ppm/.degree.C., and a second platelike insulating sheet covering the resistance element and chiefly containing at least one component selected from the group consisting of .alpha.-alumina, steatite and mullite.

Abstract: An oxygen concentration detector element 2 includes a cup-shaped solid electrolyte 20 with an inside chamber 25 opened at one end and closed at the other end. An external electrode 21 is formed on an outer surface of solid electrolyte 20 by dipping solid electrolyte 20 in first chemical plating liquid 81, while an internal electrode 22 is formed on an inner surface of solid electrolyte 20 by introducing second chemical plating liquid 82 into inside chamber 25. First, in an injecting step, an injection needle 11 is inserted into inside chamber 25 and second chemical plating liquid 82 is introduced into inside chamber 25 via injection needle 11, and then injection needle 11 is pulled out of inside chamber 25. Next, in a plating step, internal electrode 22 is formed on the inner surface of inside chamber 25 using second chemical plating liquid 82. Then, in a discharging step, residual second chemical plating liquid 82 is discharged from inside chamber 25.