Spot Scanning Using Radioactive11C Beams for Heavy-Ion Radiotherapy
E. UrakabeTatsuaki KanaiMitsutaka KanazawaA. KitagawaK. NodaT. TomitaniM. SudaY. IsekiK. HanawaKohsuke SatoMunefumi ShimboHideyuki MizunoYoichi HirataYasuyuki FutamiYoshihisa IwashitaA. Noda
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A scheme for spot scanning using 11 C beams has been developed in order to form and verify a three-dimensionally conformal irradiation field for cancer radiotherapy. By selecting the momentum spread of a 11 C beam, we could considerably decrease the distal falloff of the irradiation field, thus conserving the beam quality. To estimate and optimize the dose distribution in the irradiation field, it is essential to evaluate the precise dose distribution of spot beams. The coupling of the lateral dose and depth-dose distributions originating from a wide momentum spread should be taken into account to calculate the dose distribution of 11 C beams. The reconstructed dose distribution of the irradiation field was in good agreement with the experimental results, i.e., within ±0.2%. An irradiation field of 35×35×43 mm 3 was optimized and spot scanning using 11 C beams was carried out. The flatness was within ±2.3% with an error of 1% in the detector resolution.Keywords:
Flatness (cosmology)
Momentum (technical analysis)
Flatness approach is a straightforward method to solve the control problems of flat systems which are a class of systems whose states and control inputs can be expressed by the so-called flat outputs. Some results about flatness of systems and the advantages of studying flatness approach are presented in this paper. By using flatness approach, the controllability and other control problems for some distributed parameter systems are solved. Taking parabolic and hyperbolic systems for instances, this paper summarizes the application of flatness approach in the controllability and motion planning.
Flatness (cosmology)
Distributed parameter system
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Flatness is a important factor for updated strip producing.the clarified the signification of the flatness.Introduced several measurement parameters for the flatness.Finally the writer analysised the calculate formulation,described the structure and control principle of flatness-meter.
Flatness (cosmology)
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One of the subjects of cold rolling is a flatness of the rolled strip. Conventionally, measured strip flatness was approximated by polynomial (2th, 4th, 6th) equation across the entire strip width. This made it difficult to deal with desired loose edge or any desired flatness across the entire strip width. Also conventional flatness control was done for the entire strip width, so if there is a different flatness error among drive side and work side, conventional flatness control can not control properly. We propose independent strip flatness control among drive side and work side, and also automatic flatness control (AFC) system with arbitrary desired strip flatness. Also some applied results to cold mill are shown.
Flatness (cosmology)
Rolling mill
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In this paper, we propose the mathematical models for flatness control of aluminum foil rolling. The models are based on results from an experimental study in an actual plant and make it possible to use the differences between the characteristics of the mechanical actuators positively. A new flatness control has been developed to cope with the detection time delay and mutual interaction between the actuators.
Flatness (cosmology)
Rolling mill
Aluminum foil
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Aiming at low accuracy control of the flatness measuring system in cold rolling process, the wear of measuring rings of the flatness measuring roll is an important factor, which affects the flatness measurement accuracy and the strip quality. When the radial pressure and the width of the strip change, the wear thickness of the different measuring rings is also changed, which seriously increased the deviation between measured values and actual values. For thirty-eight measuring rings of flatness measuring roll, it is important to establish an accurate wear compensation model for each measuring ring to improve the measurement accuracy of the online flatness control model. Wear compensation model is established by the theory of Archard, definite integral method, and weighted coefficient method, and the data of the rolling length, strip width, and the radial force of the six million tons’ strip are used to analyze and discuss the wear compensation model of flatness measuring roll. The experiment result shows that the flatness control accuracy is improved effectively and the better strip shape can be achieved.
Flatness (cosmology)
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Floor is the most important part of building, and flatness of floor groundwork strongly influences flatness of floor constructed finishing material. To construct floor groundwork flatly, it is necessary to talk about flatness quantitatively among construction related parties (clients, designers, administrators, craftsmen, etc.). Japan Research Conference of Floor Construction Technology proposed a method to measure and evaluate flatness, by which everyone can easily do on construction site. This report describes the consideration on a validity of this method, and on relations between flatness of floor groundworks and flatness of floors constructed finishing material, based on measurement results in actual buildings.
Flatness (cosmology)
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A new concept rolling mill for flat products, i.e. the NSC intelligent mill (NIM), has been proposed. The NIM concept states that the mill can estimate and control roll force distribution across the width between the work roll and the rolled material during rolling. The roll force distribution reflects longitudinal stress distribution in the rolled material, which has a direct relationship with the flatness of the rolled material. Hence, the NIM enables real-time flatness detection and control, and the NIM can eliminate the limitations of conventional flatness control technology as follows: delay of control response mainly due to transport time from the rolling mill to the flatness sensor, noncontrol portion of the head end of the rolled material, and limited flatness control accuracy due to the low accuracy of the flatness sensor. A pilot mill on the laboratory scale was constructed, and the concept of NIM, as well as feasibility of the real-time estimation of roll force distribution, was verified.
Flatness (cosmology)
Rolling mill
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This paper introduces the detection method of flatness error of flat plate, designs a large-scale flatness error automatic verification system. The structure, working principle and flatness error of least square method are described in detail, the uncertainty is analyzed. The advantages of the system are compared and analyzed by experiments, and it has a good application value.
Flatness (cosmology)
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The purpose of this study is to examine a relationship between loads of lower limbs during concrete finishing work and slab flatness. Experiments were taken with 5 different concretes and forms which were size of 2,700 mm × 3,600 mm. Electromyogram (EMG) signals during work were recorded from 4 muscles of lower limb of skilled laborer and sensory tests about workability were taken. Slab flatness was measured with straightedge method. Results showed that at lower workability concrete, the integrated EMG were greater and slab flatness was low grade. It was suggested that the loads influenced slab flatness.
Flatness (cosmology)
Slab
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Slabs should be moderately flat according to users' requirement. From this concept, experiment to construct slabs under different labors was carried out at an actual building using 36 N/mm2 concrete. When required flatness were shown to finishing workers, they proposed adequate techniques to achieve them. After being approved by construction supervisors, slabs were constructed under those techniques and were measured their flatness. As the result, it was shown clearly that tamping works of unsuitable timing and displacing level pointers invent bumps very much, areas where are hard to use trowels (e.g., at pillars) are difficult to be made flat.
Flatness (cosmology)
Slab
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