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[en] The problem of locality arising in connection with the quantum-erasure experiments is considered using the algebraic approach. We demonstrate that, contrary to a widespread opinion, the results of these experiments can be reconciled with the existence of a local physical reality determining the results of local measurements. A clear physical interpretation of the quantum-erasure experiments, that is consistent with the classical concepts, is given.
[en] Analyzing shareability of correlations arising in any physical theory may be considered as a fruitful technique of studying the theory. Our present topic of discussion involves an analogous approach of studying quantum theory. For our purpose, we have deviated from the usual procedure of assessing monogamous nature of quantum correlations in the standard Bell-CHSH scenario. We have considered correlations arising in a quantum network involving independent sources. Precisely speaking, we have analyzed monogamy of nonbilocal correlations by deriving a relation restricting marginals. Interestingly, restrictions constraining distribution of nonbilocal correlations remain same irrespective of whether inputs of the nodal observers are kept fixed (in different bilocal networks) while studying nonbilocal nature of marginal correlations.
[en] At Kiev oncological centre, patients with laryngeal cancer undergo conformal radiotherapy by means of ONCOR Impression Plus (Siemens) linear accelerator. Before treatment, the patients were prepared for external beam therapy including immobilization, SCT, receiving the series of CT and processing them to choose necessary volumes of irradiation. We developed detailed algorithm of target volume delineation and conduct of external beam therapy of laryngeal cancer depending on localization of a primary tumour. The comparison of dosimetry plans in order to show importance of adequate topometric planning was carried out. The differentiated approach to the target volume delineation depends on localization and stage of the process. It makes it possible to provide treatment of laryngeal cancer at necessary total dose without serious radiotherapy affects. Adequate pre-irradiation preparation aids in decreasing probable radiation changes in key organs that influences the life quality.
[en] At the Oncological Centre in Lodz treatment of selected cases of skin carcinoma was started in 1967 using one single dose of X-rays. The dose to the skin in superficial radiotherapy ranged from 1900 to 2600 R, the size of irradiated fields from 2.5 to 24 square cm. During 3 years of follow-up one recurrence was observed in the group of 37 cases. No radionecroses developed. These observations suggest that one-time radiotherapy in selected cases of skin carcinoma is not different with regard to its results and the probability of radionecrosis from fractionated radiotherapy. (author)
[en] The problem of wave-particle duality is considered within the framework of the algebraic approach. Contrary to the widespread belief, we demonstrate that wave-particle duality can be reconciled with the assumption that there exists some local physical reality determining the results of local measurements. A number of quantum experiments—double-slit electron scattering, Wheeler’s delayed choice experiment, the past of photons passed through the interferometer—are discussed using the concept of locality. A clear physical interpretation of these experiments that does not contradict classical concepts is provided.
[en] A recent proof [H. P. Stapp, Am. J. Phys. 65, 300 (1997)], formulated in the symbolic language of modal logic, claims to show that contemporary quantum theory, viewed as a set of rules that allow us to calculate statistical predictions among certain kinds of observations, cannot be imbedded in any rational framework that conforms to the principles that (1) the experimenters close-quote choices of which experiments they will perform can be considered to be free choices, (2) outcomes of measurements are unique, and (3) the free choices just mentioned have no backward-in-time effects of any kind. This claim is similar to Bell close-quote s theorem, but much stronger, because no reality assumption alien to quantum philosophy is used. The paper being commented on [W. Unruh, Phys. Rev. A 59, 126 (1999)] argues that some such reality assumption has been 'smuggled' in. That argument is examined here and shown, I believe, to be defective. copyright 1999 The American Physical Society
[en] An information system of radioactivity in the environment was created with the goal of aggregating, storing and preserving safely and permanently the data produced by Brazilian researches and provide the research community access to a database on radioactivity in Brazil. The system provides information on radionuclide concentrations of the natural series, cosmogenic and fall out on samples of soil, water and food, among others, along with the geographical location of the sample. By this way, the location of the sample in Brazil can be visualized as well as a spreadsheet containing all the data and information about the sample can be obtained. It also provides reference information on where the samples were obtained. The system has been continuously fed and updated, containing currently, data from more than 2,000 samples. This paper presents the latest system updates and discusses the opportunities for improvement identified and implemented. (author)
[en] Nonlocality of simultaneous spatial correlation of a quantum phenomenon as demonstrated in various versions of Einstein-Podolsky-Rosen type experiment reduces to nonlocality of the measurement apparatus in the sense that the eigen-wavefunctions for the apparatus are completely specified in a manner of being independent of whatever object it may measure. Nonlocality of the measurement apparatus however serves as no more than a good approximation to reality at best. The theoretical imposition of nonlocality of the measurement apparatus as an approximation is compatible with the actual locality of quantum mechanics that dispenses with an agent claiming globally simultaneous specifiability of boundary conditions, though the genuine locality of quantum mechanics has to be examined without employing the nonlocality of the measurement apparatus. The actual locality of quantum mechanics is intrinsically irreversible in its development