306 research outputs found

    Mathematical Approach to Developing a Simulation Model of a Health Care System

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    This paper describes some needs and methods of health care modeling. It contains a general approach and the first version of a mathematical description of the processes within a health care system. Definitions of terms used in the paper are also given. Some mathematical tasks, specific for the practice of health care management, are set

    Aggregate Model for Estimating Health Care System Resource Requirements (AMER)

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    In the process of national health care system model elaboration, the model for estimating resource requirements plays an important role. Resource needs are determined on the basis of estimates of population trends and morbidity rates, and a set of desired health care standards. For the creation of the morbidity estimation model, data from comprehensive studies carried out in the UK, Japan, and the USSR were used. The desired standards were taken from the practice of central planning now existing in the USSR. Using this model in an interactive regime, it is possible to test alternative planning strategies. Preliminary results of testing and running this model in various countries show that this computer model could be used in different developed countries for estimating resource requirements

    Health Care System Models: a Review

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    In this paper, thirty-eight models of the Health Care System are described in a standardized way. Their main goals, methods, and special features are identified. Three illustrative examples of different methodologies are given in detail. To clarify the use of models for application in the health care planning process, policy problems in health care are summarized. The different stages in creating a model are described

    In situ study of zinc peroxide decomposition to zinc oxide by X-ray absorption spectroscopy and reverse Monte-Carlo simulations

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    The Zn K-edge X-ray absorption spectroscopy has been used to investigate in situ the decomposition of zinc peroxide (ZnO2_2) to zinc oxide (ZnO). Principal component and linear combination analyses of the EXAFS spectra have been employed to identify the phase composition of the oxide upon heating to 900∘^\circC. Only the ZnO2_2 phase has been found up to 180∘^\circC, whereas only the nanocrystalline ZnO phase has occurred above 250∘^\circC. Detailed structural information on the temperature dependence of the local environment of zinc atoms has been obtained using the reverse Monte Carlo simulations. A strong increase of disorder has been found upon approaching the decomposition temperature, evidenced by the broadening of Zn-O and Zn-Zn pair distribution functions and related mean-square relative displacements

    An Approach to Building a Universal Health Care Model: Morbidity Model of Degenerative Diseases

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    There have been many different approaches to building health care models. Because of these differences, it is sometimes difficult to relate the developed models to each other. We have therefore first defined the submodels of the health care system and clarified the relation of our approach to studies already undertaken. The submodels also show the steps in building the health care model. The first step was to construct the morbidity model of degenerative diseases. The validity of the model was tested for various countries, using statistics from the World Health Organization. The fit of the model to empirical data was satisfactory. The model was applied to an international comparison and estimation of trends in degenerative diseases. The study showed the feasibility of this type of approach in health planning

    On the Estimation of Morbidity

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    A mathematical model of a degenerative type disease is discussed in this paper. The model allows the user to estimate the number of new morbidity episodes and the prevalence of the disease, provided data on population age structure and age specific deaths are available. To verify the model some experiments with its computer version were carried out. The computer program listing and results of the experiments are presented

    A Computer Method for Projecting a Population Sex-Age Structure

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    A computer model which gives an opportunity to predict dynamics of the population sex-age structure is presented in this paper. The system's behavior described depends on such demographic characteristics as birth rate, death rate, and others. The given model is supposed to be used as part of a general health care system's activity model. In that case it will be possible to investigate the sex-age structure dynamics in connection with the influence of external social-economic subsystems and policy in the health care system area. The USA demographic statistic data for 1968 have been used for the model's tests, and satisfactory results have been achieved during these tests

    Identification and Quantification of Chemical Forms of Cu and Zn in MSWI Ashes Using XANES

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    Incineration is in many countries a common treatment method for municipal solid waste, and utilization of the ash residues has attracted significant interest. The bottom ash is best suited as a secondary construction material, whereas the fly ash is being investigated as a secondary raw material for recovery of, for example, Zn, Cu, and salts. For both types of application, knowledge about the chemical speciation of Zn and Cu in the ashes is valuable. The present work focuses on identifying and quantifying the chemical species of Zn and Cu in 12 samples of fly ash and bottom ash from three waste-to-energy plants using X-ray absorption near edge structure (XANES). The XANES spectra of the ash samples showed similar distinctive features, and both in the bottom and fly ash samples, the same chemical forms were identified but in various ratios. Cu and Zn occurred in several chemical forms, with typically 5-7 forms present in the same sample. For Cu, the XANES spectra of the fly ash samples were nearly identical, indicating very similar chemical speciation (same chemical forms and similar ratios). Cu was found to exist in various oxide, hydroxide, chloride, silicate, and metallic forms. The most commonly occurring Zn compounds were the aluminate, ferrite, silicate, and oxide along with chloride, basic carbonate (hydrozincite), and occasionally metallic forms, probably alloyed with Cu in brass. Cu occurred in different oxidation states from zero to +II, with a higher prevalence of the lower oxidation states in bottom ash than in fly ash. Zn occurred mainly in oxidation state +II in all ashes analyzed. Finally, we showed that during outdoor storage of bottom ash, levels of Cu and Zn hydroxycarbonates were increased compared to fresh bottom ash. This carbonate formation aims to make Cu and Zn less leachable

    Luminescence and vacuum ultraviolet excitation spectroscopy of cerium doped Gd3Ga3Al2O12 single crystalline scintillators under synchrotron radiation excitations

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    Authors gratefully acknowledge the financial support from the Latvian Science Council grant LZP-2018/2-0358 . The research leading to this result has been supported by the project CALIPSO plus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON2020 . The work of A.P.K. was supported by the Ministry of Science and Higher Education of the Russian Federation , state contracts No. 11.6181.2017/ITR .Cerium doped Gd3Ga3Al2O12 (GGAG) single crystals as well as GGAG:Ce single crystals co-doped by divalent (Mg2+, Ca2+), trivalent (Sc3+) or tetravalent (Zr4+, Ti4+) ions have been studied by means of the excitation luminescence spectroscopy in vacuum ultraviolet spectral range. Synchrotron radiation from the undulator beam was utilized for the luminescence excitation in the energy range from 4.5 to 800 eV. The influence of the co-dopant ions on the excitonic transitions as well as on the intrinsic defects in GGAG was revealed examining the luminescence emission and excitation spectra of both Gd3+ and Ce3+ ions in all single crystals studied. Special attention was paid to the analysis of Ce3+ excitation spectra in VUV spectral range (4.5–45 eV) where multiplication of electronic excitation (MEE) processes occur. It was obtained that GGAG:Ce single crystals having different co-dopant ions reveal distinguished efficiency of MEE. The role of intrinsic defects in MEE processes in the co-doped GGAG:Ce single crystals was elucidated.Latvian Science Council LZP-2018/2-0358,730872; Ministry of Science and Higher Education of the Russian Federation 11.6181.2017/ITR; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²https://www.sciencedirect.com/science/article/pii/S2211379719334527?via%3Dihu
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