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101.
P. Carrasqueira H. Rocha J. M. Dias T. Ventura B. C. Ferreira M. C. Lopes 《International Transactions in Operational Research》2023,30(1):206-223
Radiation therapy is a technology-driven cancer treatment modality that has experienced significant advances over the last decades, due to multidisciplinary contributions that include engineering and computing. Recent technological developments allow the use of noncoplanar volumetric modulated arc therapy (VMAT), one of the most recent photon treatment techniques, in clinical practice. In this work, an automated noncoplanar arc trajectory optimization framework designed in two modular phases is presented. First, a noncoplanar beam angle optimization algorithm is used to obtain a set of noncoplanar irradiation directions. Then, anchored in these directions, an optimization strategy is proposed to compute an optimal arc trajectory. The computational experiments considered a pool of twelve difficult head-and-neck tumor cases. It was possible to observe that, for some of these cases, the optimized noncoplanar arc trajectories led to significant treatment planning quality improvements, when compared with coplanar VMAT treatment plans. Although these experiments were done in a research environment treatment planning software (matRad), the conclusions can be of interest for a clinical setting: automated procedures can simplify the current treatment workflow, produce high-quality treatment plans, making better use of human resources and allowing for unbiased comparisons between different treatment techniques. 相似文献
102.
103.
Rukomoynikov A. A. Yuminov I. P. Khamitov A. I. Garifullin I. Sh. Agliullin Ya. F. 《Russian Engineering Research》2022,42(9):916-919
Russian Engineering Research - Systems are considered for the dehydration of petroleum so as to separate water–petroleum emulsions. In particular, the low-temperature microwave (UHF)... 相似文献
104.
Singh A. K. Chandra Devesh Kattayat Sandhya Kumar Shalendra Alvi P. A. Rathi Amit 《Semiconductors》2019,53(12):1584-1592
Semiconductors - Compositional variations in GaAs based ternary alloys have exhibited wide range alterations in electronic properties. In the present paper, first-principles study of... 相似文献
105.
Shabaldin A. A. Konstantinov P. P. Kurdyukov D. A. Lukyanova L. N. Samunin A. Yu. Stovpiaga E. Yu. Burkov A. T. 《Semiconductors》2019,53(6):742-746
Semiconductors - Nanocomposite thermoelectrics based on Bi0.45Sb1.55Te2.985 solid solution of p-type conductivity are fabricated by the hot pressing of nanopowders of this solid solution with the... 相似文献
106.
Kulikov V. Yu. Aubakirov D. R. Kvon S. S. Dostaeva A. M. Shcherbakova E. P. 《Metallurgist》2019,62(9-10):1068-1072
Metallurgist - We provide an overview of requirements for wear-resistant materials in the Kazakhstani ore mining and smelting industry, and describe the basic variety of metallurgical parts and... 相似文献
107.
Toby J. Holda Lars G. Rudstam Kelly L. Bowen Brian C. Weidel James M. Watkins Patrick J. Sullivan Jeremy P. Holden Michael J. Connerton 《Journal of Great Lakes research》2019,45(2):307-316
Mysis diluviana is a major component of prey fish diets in the Great Lakes, so annual production of M. diluviana is important for understanding and modeling energy flow through Great Lakes food webs. However, only three lake-wide measurements of M. diluviana annual production in Lake Ontario are currently available (1971, 1990, 1995). During 2013, lake-wide coverage of Lake Ontario was achieved during four periods from April to November. Annual mean density and biomass of M. diluviana in 2013 were 99?#/m2 (SE: 8) and 318?mg?dw/m2 (SE: 28) – approximately half of values observed in 1990s. M. diluviana comprised 13–30% of offshore zooplankton biomass in each period. Reproduction peaked in fall, with mean brood size of 32 embryos (range: 11–49), at least 10% larger than in 1990s. Generation time was two years from embryo to initial reproduction. Growth rates were 0.052?mm/d for the age-0 cohort and 0.027?mm/d for the age-1 cohort. Age-0 growth rate was significantly higher than in 1980s–90s (0.035?mm/d). Annual production in 2013 was 0.85?g?dw/m2/yr (SE: 0.03) which was 30–40% of values observed in 1990 and 1995 (2.23 and 2.53?g/m2/yr). Annual production to biomass ratio (P/B) in 2013 was 2.65?/yr which was 80–85% of values observed in 1990 and 1995 (3.24 and 3.11?/yr), but this difference was not statistically significant. Our results suggest that changes in annual production over time can be estimated using changes in biomass over time and a mean P/B ratio. 相似文献
108.
Measurement Techniques - We briefly describe the special considerations that must be taken into account in experimental aerodynamics when using videogrammetry for non-intrusive measurement of... 相似文献
109.
Measurement Techniques - We consider some (earlier neglected) uncertainties of temperature measurements that may appear in the course of calibration of radiation thermometers (pyrometers) aimed at... 相似文献
110.
High Temperature - The development of the initial stage of instability of a contact boundary of colliding metal plates has been numerically simulated. The mathematical model is based on the Euler... 相似文献