摘要:
A tunnel computerised tomographic scanner comprising a rotor (3), an X-ray emitter (7) mounted on the rotor (3), an X-ray detector (8) mounted on the rotor (3), on the opposite side of a detecting zone (4), the X-ray detector (8) comprising a scintillator (9) which has at least one emission face (10) from which the scintillator (9) emits light in the visible spectrum when it is struck by X-rays, and a plurality of video cameras (12) which are positioned in such a way that each of them frames at least one portion of the scintillator (9), for acquiring one after another operating images, in the visible spectrum, of the respective portion of the scintillator (9), wherein, according to the method, at least two separate video cameras (12) substantially frame each portion of the scintillator (9), and an electronic processing unit is programmed to combine all of the operating images obtained by the video cameras (12) and to obtain a main image of the scintillator, to be used for the tomographic reconstruction of an object (6) which is placed in the detecting zone (4).
摘要:
This invention relates to a method for non-destructive inspection of a log (1) to identify inner zones of sapwood (14) of the log (1) that have not been attacked by fungi that cause bluestain in the wood. The method comprises a first step of carrying out a tomographic scan of the log (1) to be inspected using X-ray beams that pass through the log (1) and a second step of obtaining a three-dimensional representation of the log (1) that is representative of the local moisture content of the log, the local moisture content being correlated with attenuation of the X-ray beams through the log. The method comprises the step of processing the three-dimensional representation of the log (1) to identify inner regions (145) of the log (1), in which the local moisture content is greater than or equal to a moisture threshold value for a spatial extent greater than an extent threshold. The moisture threshold value corresponds, for trees of the same species as the log (1), to a sapwood (14) with local moisture content such that it excludes the growth of fungi that cause bluestain in the wood. Each inner region (145) identified in this way is classed as a sapwood (14) zone free of bluestain. This invention also relates to a procedure for obtaining one or more wooden products from a log (1), as well as an apparatus for carrying out a non-destructive inspection of a log (1).
摘要:
The invention relates to an inverter-generator apparatus (100) which comprises: - a polyphase voltage generator (PMG); - a rectifying/control stage (10); - a DC/AC converter stage (40) connected to the rectifying/control stage and which includes an analog/digital control unit (CONTR); - a voltage storage stage (50) interposed between the rectifying/control stage and the converter stage, which includes a first capacitor (Ch) for storing a first direct voltage (VDC+) and a second capacitor (Cl) for storing a second direct voltage (VDC-). The rectifying/control stage includes: - a first (1) and a distinct second (2) group of mutually equal controlled-trigger semiconductor electronic devices (3); - a first control circuit (60) of the controlled-trigger semiconductor electronic devices of the first group and a second control circuit (70) of the controlled-trigger semiconductor electronic devices of the second group. The analog/digital control unit (CONTR) is configured to generate a first reference voltage (Vref1) and a second reference voltage (Vref2) to be supplied to the first and second control circuits, respectively, to keep the first direct voltage in the first capacitor and the second direct voltage in the second capacitor equal to predetermined constant values.
摘要:
A method for evaluating the modulus of elasticity of a wooden element such as a log or a plank at a reference temperature comprises the operating steps of: generating a sound wave in the wooden element (1); determining the actual velocity of propagation of the sound wave in the wooden element (1) or another quantity linked to it by a known formula; measuring the temperature of the wooden element (1); and using the temperature measured and the actual velocity of propagation measured, or the other quantity linked to it, for evaluating the modulus of elasticity at a preset reference temperature.
The method also comprises the temperature measurement step being carried out by measuring the internal temperature of the wooden element (1 ).
摘要:
A method for identifying the cutting pattern for pieces of wood such as logs comprises the following operating steps: obtaining a virtual three-dimensional model (1) of the density of the piece of wood; selecting a possible first virtual cutting pattern (4) for the piece of wood which may allow one or more semi-finished products (3) to be obtained from the piece of wood; applying virtually the first virtual cutting pattern (4) to the three-dimensional model (1) of the piece of wood, to obtain one or more virtual semi-finished products (3); virtually associating with the virtual semi-finished products (3), the corresponding density identified on the basis of the three-dimensional model (1); processing, for each virtual semi-finished product (3), an estimate of its mechanical properties based on its density; repeating the selection, application, association and processing steps for a plurality of different possible cutting patterns (4); comparing the estimates regarding the mechanical properties of the virtual semi-finished products (3) which can be obtained with the different cutting patterns (4) and, based on this comparison, choosing the actual cutting pattern (4).
摘要:
A method for determining the nodosity of a wooden plank comprises the operating steps of observing the lateral surface (4) of the wooden plank (1) to identify its zones (7) corresponding to knots (6), assessing the overall extent of the knots (6) inside the plank (1) and the relative volume, and determining the nodosity as a ratio of the volume occupied by the knots (6) to the overall volume of the plank (1) or the remaining volume of the plank (1). The step of assessing the extent of the knots (6) in turn comprises the operating steps of estimating the position in space, relative to the plank (1), of the longitudinal axis (8) of the log (2) from which the plank (1) was obtained and assuming that each knot (6) comprises a conical body extending radially from the longitudinal axis (8) with the vertex on the longitudinal axis, and passing through the zone (7) of the lateral surface (4) of the plank (1) corresponding to the knot (6), and calculating the volume of the knots (6) as the intersection between said bodies and the plank (1).