26 research outputs found

    Small hiatal hernia as a risk factor of atrial fibrillation

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    Purpose: Hiatal hernia (HH) is considered a risk factor of atrial fibrillation (AF). The aim of this study was to evaluate HH in computed tomography (CT) images in patients awaiting ablation due to atrial fibrillation, and to look for a correlation between HH in patients without AF and with AF. Material and methods: This study included 441 patients divided in two groups: 207 patients subjected to computed tomography before ablation procedure due to atrial fibrillation and 234 patients as the control group, who underwent CT scans to rule out coronary disease (no AF in history). Results: Small HH, e.g. under or equal to 2 cm, are associated with a higher risk of AF compared to the control group, which was not observed for bigger HH. Conclusions: The presence of small HH may be a risk factor of AF

    Modeling of the Drying Process of Apple Pomace

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    Understanding biological materials is quite complicated. The material apple pomace is biologically unstable has been dried under certain conditions. Modeling the pomace drying is necessary to understand the heat and mass transport mechanism and is a prerequisite for the mathematical description of the entire process. Such a model plays an important role in the optimization or control of working conditions. Modeling of the pomace drying process is difficult as apple pomace is highly heterogeneous, as it consists of flesh, seeds, seed covers, and petioles of various sizes, shapes and proportions. A simple mathematical model (Page) was used, which describes well the entire course of the drying process. This is used to control the process. In turn, complex mathematical models describe the phenomena and scientifically explain the essence of drying. Mathematical modeling of the dewatering process is an indispensable part of the design, development and optimization of drying equipment

    Modeling of the Drying Process of Apple Pomace

    No full text
    Understanding biological materials is quite complicated. The material apple pomace is biologically unstable has been dried under certain conditions. Modeling the pomace drying is necessary to understand the heat and mass transport mechanism and is a prerequisite for the mathematical description of the entire process. Such a model plays an important role in the optimization or control of working conditions. Modeling of the pomace drying process is difficult as apple pomace is highly heterogeneous, as it consists of flesh, seeds, seed covers, and petioles of various sizes, shapes and proportions. A simple mathematical model (Page) was used, which describes well the entire course of the drying process. This is used to control the process. In turn, complex mathematical models describe the phenomena and scientifically explain the essence of drying. Mathematical modeling of the dewatering process is an indispensable part of the design, development and optimization of drying equipment

    Analysis of Material-Characterization Properties of Post-Production Waste—The Case of Apple Pomace

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    The paper presents the material-characterization properties of apple pomace—the post-production waste of juice pressing. Tests were carried out on the basic physical properties of apple pomace: color, specific-density, and energy properties. Extensive material-composition analyses based on DSC (differential scanning calorimetry) and TGA (thermogravimetry) methods were also performed. It has been shown that pomace, due to its energy value, can be a good fuel. The obtained thermal data confirm the presence of cellulose, hemicelluloses, lignins and pectins in the analyzed pomace. The results confirm that dried apple pomace is microbiologically stable with good health-promoting properties

    Modelling of biomass temperature in the drying process

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    The goal of the work was to propose and verify the model of temperature changes of the convective dried biomass depending on the drying time. The algebraic temperature model of the convective dried solid, giving the possibility of its direct calculation, was based on the logistic function of growth. Temperature model was verified for convective dried biomass: vegetable and wood (poplar and willow wood chips) significantly differing in initial moisture content. Parameter W in the temperature model, defined as the coefficient of temperature rate changes reaches greater values in higher temperature of drying air and for wood biomass which has lower initial moisture content. Empirically selected parameter W allows to verify the temperature model with the relative error less than 5%

    Analysis of thermal properties of coffee grounds left over from coffee percolation

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    Coffee is one of the most popular beverages worldwide. The goal of this work is an estimation of the qualities of waste coffee grounds as a material used in biofuel production. There were selected two most popular coffee beans mixtures: arabica and arabica with robusta, as well as chocolate-flavoured coffee and green coffee (unroasted coffee beans). All types of coffee had approximately the same ash value its average oscillating between 2,59-3,21%. Calorific value of the dried waste coffee grounds after coffee percolation places it among very good energy material

    Efficiency analysis of photovoltaic systems

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    The goal of the study was to analyse the efficiency of two existing photovoltaic micro-installations with the power of approx. 40 kWp. The main factor differing the two installations being analysed was the arrangement of modules in relation to the sides of the world, one is south-west and the other is east-west. The total yield of electrical energy in 2017 from the south-west installation was higher and amounted to 34980 kWh. For the east-west installation the amount of energy generated was equal to 31180 kWh. 4 methods of forecasting electrical energy yield were discussed. Simple computational method proved to be the best method for both installations

    Analysis of possibilities of using biomass from cherry and morello cherry stones for energy purposes

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    Growing demand for energy and care about natural environment is the motivation to find alternative sources of energy. One of them is biomass from cherry and morello cherry stones, which is food processing industry waste. Stones have fairly good physical properties regarding material for combustion. Cherry and morello cherry crop in Poland is at the level of 200 thousand tons yearly, and processing them generates a considerable amount of waste that consists of stones, which may be used for energy purposes. In the work, the initial water content (u), curves of combustion in different temperatures, percentage ash content, heat of combustion and percentage share of stone in the whole fruit were determined
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