Abstract: An X-ray computed tomographic apparatus includes an X-ray tube which generates X-rays, an X-ray detecting unit which detects X-rays transmitted through a subject to be examined to acquire projection data, an image reconstructing unit which reconstructs image data from the acquired projection data, and a tube current value setting unit which sets a tube current value for the X-ray tube on the basis of the projection data and information about contrast examination planned for the subject.

Abstract: An X-ray computed tomographic apparatus includes an X-ray tube which generates X-rays, an X-ray detecting unit which detects X-rays transmitted through a subject to be examined to acquire projection data, an image reconstructing unit which reconstructs image data from the acquired projection data, and a tube current value setting unit which sets a tube current value for the X-ray tube on the basis of the projection data and information about contrast examination planned for the subject.

Abstract: This invention relates to an actuator for a valve to be loaded in a rotary valve, such as a ball valve or a butterfly valve. An object is to make it possible to control the angle of the valve accurately, detect the open-close position of the valve accurately and materialize reduction of size and weight and saving of cost owing to the simplification of structure. Another object is to provide a compact and economically excellent actuator for a valve which enables valve opening-detecting members, such as limit switches and potentiometers and other component members to be put to common use without reference to the size of the output torque and ensures accurate detection of the open-close position of the valve.

Abstract: An X-ray absorptance map associated with an object to be examined is generated on the basis of scanogram data obtained from a predetermined direction of the object, and imaging conditions are determined on the basis of the absorptance map. Before tomography, an index representing a radiation dose in the execution of scan in accordance with the imaging conditions is calculated and displayed, together with the imaging conditions. Every time the imaging conditions are changed, an index representing a radiation dose is calculated and displayed. Tomography is executed in accordance with the finally determined imaging conditions. This makes it possible to reduce the radiation dose to the object and obtain a tomographic image with high quality.

Abstract: An X-ray CT scanner comprises an X-ray source generating an X-ray, detector detecting the X-ray transmitted through an object, processor to produce projection data, and reconstruction unit to reconstruct an image using the projection data. The processor produces the projection image by applying, to an output signal from the detector, logarithm conversion processing on a function deviating from an ideal logarithm function. The ideal logarithm function is a logarithm function defined by a mathematical formula of y=K·log [b, x] (wherein a variable x is an input, a variable y is an output, and a reference K shows a scaling constant). The function deviating from the ideal logarithm function has an input/output characteristic deviating from that of the ideal logarithm function. Such deviating function is for example a linear function and applied to a conversion of only low-count data into its projection data to suppress low-count artifacts on reconstructed CT images.

Abstract: An X-ray computed tomographic apparatus includes a gantry, a reconstructing portion, and a tube current value determining portion. The gantry acquires projection data of an arbitrary range in a body axial direction by continuously moving a tabletop on which a subject is laid down and by continuously rotating an X-ray tube about the subject. The reconstructing portion reconstructs image data from the acquired projection data according to reconstruction processing selected by an operator from plural types of reconstruction processing. The tube current value determining portion determines plural tube current values respectively corresponding to discrete, plural positions within the range, on the basis of the selected type of reconstruction processing and an image quality level specified or selected by the operator.

Abstract: An X-ray CT scanner comprises an X-ray source generating an X-ray, detector detecting the X-ray transmitted through an object, processor to produce projection data, and reconstruction unit to reconstruct an image using the projection data. The processor produces the projection image by applying, to an output signal from the detector, logarithm conversion processing on a function deviating from an ideal logarithm function. The ideal logarithm function is a logarithm function defined by a mathematical formula of y=K·log [b, x] (wherein a variable x is an input, a variable y is an output, and a reference K shows a scaling constant). The function deviating from the ideal logarithm function has an input/output characteristic deviating from that of the ideal logarithm function. Such deviating function is for example a linear function and applied to a conversion of only low-count data into its projection data to suppress low-count artifacts on reconstructed CT images.

Abstract: An X-ray absorptance map associated with an object to be examined is generated on the basis of scanogram data obtained from a predetermined direction of the object, and imaging conditions are determined on the basis of the absorptance map. Before tomography, an index representing a radiation dose in the execution of scan in accordance with the imaging conditions is calculated and displayed, together with the imaging conditions. Every time the imaging conditions are changed, an index representing a radiation dose is calculated and displayed. Tomography is executed in accordance with the finally determined imaging conditions. This makes it possible to reduce the radiation dose to the object and obtain a tomographic image with high quality.

Abstract: Raw water containing organic chlorine compounds is supplied in an aeration tank, wherein the organic chlorine compounds contained in the raw water are transferred into air or gas. The gas obtained from the aeration tank is collected in a treatment solution of a decomposition-treatment tank. The treatment solution contains an oxidizing agent and ultraviolet rays are irradiated to the treatment solution in the decomposition-treatment tank to activate the oxidizing agent, to thereby oxidization-decompose the organic chlorine compounds in the gas.

Abstract: Raw water containing organic chlorine compounds is supplied in an aeration tank, wherein the organic chlorine compounds contained in the raw water are transferred into air or gas. The gas obtained from the aeration tank is collected in a treatment solution of a decomposition-treatment tank. The treatment solution contains an oxidizing agent and ultraviolet rays are irradiated to the treatment solution in the deocmposition-treatment tank to activate the oxidizing agent, to thereby oxidization-decompose the organic chlorine compounds in the gas.

Abstract: Raw water such as polluted ground water can be recovered to clean water through the following processes. Firstly, oxidizing agent is added to raw water to disinfect bacteria, and then after suspended solid is removed from the water, ultraviolet rays are irradiated on the water so that organic chlorine compounds can be decomposed by active oxygen generated by the irradiation of ultraviolet rays. Finally, the residual oxidizing agent remaining in the treated water is reduced by activated carbon and catalytic resin. Further, the organic chlorine compound decomposition reaction is promoted at pH of 9 or below and in a temperature range of 15 to 30.degree. C.