The Experts below are selected from a list of 28491 Experts worldwide ranked by ideXlab platform
Waldemar Ulmer - One of the best experts on this subject based on the ideXlab platform.
-
A new Calculation Formula of the nuclear cross-section of therapeutic protons
International Journal of Cancer Therapy and Oncology, 2014Co-Authors: Waldemar UlmerAbstract:Purpose: We have previously developed for nuclear cross-sections of therapeutic protons a Calculation model, which is founded on the collective model as well as a quantum mechanical many particle problem to derive the S matrix and transition probabilities. In this communication, we show that the resonances can be derived by shifted Gaussian functions, whereas the unspecific nuclear interaction compounds can be represented by an error function, which also provides the asymptotic behavior. Method: The energy shifts can be interpreted in terms of necessary domains of energy to excite typical nuclear processes. Thus the necessary Formulas referring to previous Calculations of nuclear cross-sections will be represented. The mass number A N determines the strong interaction range, i.e. R Strong = 1.2·10 -13 ·A N 1/3 cm. The threshold energy E Th of the energy barrier is determined by the condition E strong = E Coulomb . Results and Conclusion : A linear combination of Gaussians, which contain additional energy shifts, and an error function incorporate a possible representation of Fermi-Dirac statistics, which is applied here to nuclear excitations and reaction with release of secondary particles. The new Calculation Formula provides a better understanding of different types of resonances occurring in nuclear interactions with protons. The present study is mainly a continuation of published papers. 1-3 -------------------------------- Cite this article as : Ulmer W. A new Calculation Formula of the nuclear cross-section of therapeutic protons. Int J Cancer Ther Oncol 2014; 2(2):020211. DOI: 10.14319/ijcto.0202.11
-
a new Calculation Formula of the nuclear cross section of therapeutic protons
arXiv: Medical Physics, 2014Co-Authors: Waldemar UlmerAbstract:We have previously developed for nuclear cross-sections of therapeutic protons a Calculation model, which is founded on the collective model as well as a quantum mechanical many particle problem to derive the S matrix and transition probabilities. In this communication, we show that the resonances can be derived by shifted Gaussian functions, whereas the unspecific nuclear interaction compounds can be represented by an error function, which also provides the asymptotic behavior. The energy shifts can be interpreted in terms of necessary domains of energy to excite typical nuclear processes. Thus the necessary Formulas referring to previous Calculations of nuclear cross-sections will be represented in section 2. The mass number AN determines the strong interaction range. The threshold energy ETh of the energy barrier is determined by the condition Estrong = ECoulomb. A linear combination of Gaussians, which contain additional energy shifts, and an error function incorporate a possible representation of Fermi-Dirac statistics, which is applied here to nuclear excitations and reaction with release of secondary particles. The new Calculation Formula provides a better understanding of different types of resonances occurring in nuclear interactions with protons. The present study is mainly a continuation of previous papers.
Haibo Wang - One of the best experts on this subject based on the ideXlab platform.
-
Unified Calculation Formula for predicting the shear stresses in prismatic and non-prismatic beams with corrugated steel webs
Structures, 2021Co-Authors: Man Zhou, Jiacong Liao, Jitao Zhong, Haibo WangAbstract:Abstract The existing shear design theories for hybrid beams with corrugated steel webs (CSWs) used in China and Japan were originally proposed for only prismatic hybrid beams with CSWs. The traditional Calculation method assumes that the bending stiffness and axial stiffness of a beam with CSWs are provided by the top and bottom concrete flanges, while the shear stiffness is contributed entirely by the CSWs. However, due to the influence of the Resal effect on a non-prismatic hybrid beam with CSWs, the calculated shear stress of the CSWs will be overpredicted if the shear capacities of the top and bottom concrete flanges are ignored (especially for the case of an inclined bottom flange). These traditional assumptions may no longer be applicable to non-prismatic structural members. Considering the Resal effect and accordion effect of non-prismatic beams with CSWs, this study proposed a practical unified Calculation Formula suitable for calculating the shear stresses of prismatic and non-prismatic hybrid beams with CSWs. The accuracy and adaptability of this unified Calculation Formula were verified through prismatic and non-prismatic beam model tests as well as finite element simulations. Moreover, the authors quantitatively discussed the Calculation errors of the traditional Calculation assumptions for non-prismatic beams with CSWs. In addition, a finite element parameter analysis was performed on a non-prismatic beam with CSWs near the support to clarify the applicable conditions of the unified Calculation Formula. The numerical results show that when the inclination angle of the bottom flange varies within the range of 0° to 20°, the Calculation error of the proposed unified Calculation Formula is controlled to within 15%, exhibiting good adaptability to changes in the inclination angle. The unified Calculation Formula can still predict the shear stresses in tapered CSWs with an error of less than 20% when the sum of the thicknesses of the top and bottom concrete flanges does not exceed 20% of the total beam height. It is expected that this study can further develop the shear stress Calculation theory for non-prismatic beams with CSWs, thus providing a reference for the reasonable design of tapered CSWs.
Zhang Hai-tao - One of the best experts on this subject based on the ideXlab platform.
-
Formulation of Calculation Formula for Concrete Strength in Lianyungang Area Using Quick Concrete Strength Test (4 h Press and Steam Curing Method)
Coastal Engineering, 2003Co-Authors: Zhang Hai-taoAbstract:Tests for the concretes with different caving degrees and water-cement ratios were made for quick Calculation of concrete strength, and the Calculation Formula for concrete strength in the Lianyungang area was Formulated based on above test results. The applicable ranges of the Calculation Formula were analysed, and it is shown from the test data that the Calculation Formula can be applied in the highway construction in the Lianyungang area.
Man Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Unified Calculation Formula for predicting the shear stresses in prismatic and non-prismatic beams with corrugated steel webs
Structures, 2021Co-Authors: Man Zhou, Jiacong Liao, Jitao Zhong, Haibo WangAbstract:Abstract The existing shear design theories for hybrid beams with corrugated steel webs (CSWs) used in China and Japan were originally proposed for only prismatic hybrid beams with CSWs. The traditional Calculation method assumes that the bending stiffness and axial stiffness of a beam with CSWs are provided by the top and bottom concrete flanges, while the shear stiffness is contributed entirely by the CSWs. However, due to the influence of the Resal effect on a non-prismatic hybrid beam with CSWs, the calculated shear stress of the CSWs will be overpredicted if the shear capacities of the top and bottom concrete flanges are ignored (especially for the case of an inclined bottom flange). These traditional assumptions may no longer be applicable to non-prismatic structural members. Considering the Resal effect and accordion effect of non-prismatic beams with CSWs, this study proposed a practical unified Calculation Formula suitable for calculating the shear stresses of prismatic and non-prismatic hybrid beams with CSWs. The accuracy and adaptability of this unified Calculation Formula were verified through prismatic and non-prismatic beam model tests as well as finite element simulations. Moreover, the authors quantitatively discussed the Calculation errors of the traditional Calculation assumptions for non-prismatic beams with CSWs. In addition, a finite element parameter analysis was performed on a non-prismatic beam with CSWs near the support to clarify the applicable conditions of the unified Calculation Formula. The numerical results show that when the inclination angle of the bottom flange varies within the range of 0° to 20°, the Calculation error of the proposed unified Calculation Formula is controlled to within 15%, exhibiting good adaptability to changes in the inclination angle. The unified Calculation Formula can still predict the shear stresses in tapered CSWs with an error of less than 20% when the sum of the thicknesses of the top and bottom concrete flanges does not exceed 20% of the total beam height. It is expected that this study can further develop the shear stress Calculation theory for non-prismatic beams with CSWs, thus providing a reference for the reasonable design of tapered CSWs.
Chris Koen - One of the best experts on this subject based on the ideXlab platform.
-
The Nyquist frequency for irregularly spaced time-series: a Calculation Formula
Monthly Notices of the Royal Astronomical Society, 2006Co-Authors: Chris KoenAbstract:Eyer & Bartholdi showed that the Nyquist frequency of irregularly sampled time-series can be very high. In this paper, a Calculation Formula for the Nyquist frequency is presented. In practice there is an upper limit of 0.5/Δ on this frequency, where A is the best accuracy with which time is recorded.
