58 research outputs found

    Anomalous diffusion on fractal structure of magnetic membranes

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    The concept of diffusion on fractal structure of polymeric membrane with magnetic powder is presented. The fractal characteristics, i.e. static fractal dimension df and fractal dimension of the trajectory of the random walk dw, were evaluated for qualitative and quantitative description of membrane structures. The way of introducing the fractal dimension and anomalous-diffusion exponent into the generalized diffusion equation on fractal geometries obtained by Metzler et al. has been shown. The results showed that the random walk within the membranes of the smallest granulation of magnetic powder was of the most subdiffusive character

    Is FLT3 internal tandem duplication an unfavorable risk factor for high risk children with acute myeloid leukemia? : Polish experience

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    According to the AML-BFM 2004 Interim, a treatment protocol used in Poland since 2005, presence of FLT3 internal tandem duplication (FLT3/ITD) qualifies a patient with acute myeloid leukemia (AML) to a high-risk group (HRG). The present study was aimed to identify the prevalence of FLT3/ITD in children with AML in Poland and to evaluate its prognostic significance in the HRG patients. Out of 291 children with de novo AML treated in 14 Polish centers between January 2006 and December 2012, samples from 174 patients were available for FLT3/ITD analysis. Among study patients 108 children (61.7%) were qualified to HRG. Genomic DNA samples from bone marrow were tested for identification of FLT3/ITD mutation by PCR amplification of exon 14 and 15 of FLT3 gene. Clinical features and treatment outcome in patients with and without FLT3/ITD were analyzed in the study. The FLT3/ITD was found in 14 (12.9%) of 108 HRG children. There were no significant differences between children with and without FLT3/ITD in age and FAB distribution. The white blood cells count in peripheral blood at diagnosis was significantly higher (p <0.01) in the children with FLT3/ITD. Over 5-year overall survival rate for FLT3/ITD positive children was worse (42.4%) comparing to FLT3/ITD negative children (58.9%), but the statistical difference was not significant. However, over 5-year survivals free from treatment failures were similar. The FLT3/ITD rate (12.9%) observed in the study corresponded to the published data. There was no significant impact of FLT3/ITD mutation on survival rates, although further studies are needed on this subject

    Intrauterine deaths — an unsolved problem in Polish perinatology

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    Objectives: The Polish criteria for “intrauterine death” include fetal demise after 22 weeks of gestation, weighing &gt; 500 g and body length at least 25 cm, when the gestational age is unknown. The rate of fetal death in Poland in 2015 is 3:10,000. In 2020, 1,231 stillbirths were registered. Material and methods: An analysis using 142,662 births in the period between 2015–2020 in 11 living in Poland. The first subgroup was admitted as patients &gt; 22 to the beginning of the 30th week of pregnancy (n = 229), and the second from the 30th week of pregnancy inclusively (n = 179). In the case of women from both subgroups, there was a risk of preterm delivery close to hospitalization. Results: It was found that stillbirth in 41% of women in the first pregnancy. For the patient, stillbirth was also the first in his life. The average stillbirth weight was 1487 g, the average body length was 40 cm. Among fetuses up to 30 weeks, male fetuses are born more often, in subgroup II, the sex of the child was usually female. Most fetal deaths occur in mothers &lt; 15 and &gt; 45 years of age. Conclusions: According to the Polish results of the origin of full-term fetuses &gt; 30 weeks of gestation for death in the concomitant antenatal, such as placental-umbilical and fetal hypoxia, acute intrapartum effects rarely, and moreover &lt; 30 Hbd fetal growth restriction (FGR), occurring placental-umbilical, acute intrapartum often

    Analysis of the Main Coal Mining Restructuring Policy Objectives in the Light of Polish Mining Companies’ Ability to Change

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    This article presents the results from research performed on the implementation of restructuring policies of Polish mining enterprises. The study sought to verify whether the changes planned in Poland since the 1990s have been successfully introduced. The main objective of the restructuring of the Polish mining industry was to transform it into a profitable, cost-effective sector, which would be able to survive in a competitive market. The study also allowed the determination of a ratio giving a clear and synthetic outcome&mdash;called the indicator of the ability to change (WZZ). This indicator included criteria for assessing the efficiency of a company during the process of change, the fundamental errors committed during the change process, and the reasons for a low level of ability to change. The WZZ indicator achieved only an average level of 30%. The main errors committed during the change process are the mining enterprises&rsquo; lack of experience in change management and a lack of executive conviction about the need not only for proper management of the process of change, but also for change in general. The problem is also a lack of adequate knowledge, competence in the field of change management, and communication with employees. Low level of ability to change is caused by the inflexible organizational structure, the organizational culture, a lack of motivation, and the limited flexibility of the human factor

    Characteristics of Some Selected Methods of Rare Earth Elements Recovery from Coal Fly Ashes

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    The article covers the issues related to the characteristics, application, and some methods of rare earth elements (REEs) recovery from coal fly ashes. REEs are elements with growing demand and a very wide range of application, especially when it comes to modern technologies. The conducted analysis and price forecast proved the existing upward tendency, and this confirmed the need to search for new REE sources, among industrial waste (proecological effect). The development of the REE recovery technology would involve solving several problems related to REE speciation, optimization of factors controlling their extractivity and selection of the REE separation method from obtained extraction solutions with a very extreme pH and complicated composition. The paper presented advantages and disadvantages of usually used methods of REE separation from coal fly ashes, like physical and acid–base leaching. It was also presented alternative REE recovery techniques in the form of membrane and biological methods and based on ion liquids (ILs) or chelating agents. The directions of further modifications, which will allow the efficient REE recovery were presented. The aim of this article was to propose specific solutions based on the creation of appropriate multistage method of REE recovery. It will be a combination of magnetic and size separation, acid–base leaching (including roasting in justified cases), removal of matrix elements with ILs (Al, Si, and Fe), and finally REE membrane separation, allowing one to obtain the appropriate process efficiency

    The Impact of the COVID-19 Pandemic on Gaseous and Solid Air Pollutants Concentrations and Emissions in the EU, with Particular Emphasis on Poland

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    This article presents the research on the analysis of the impact of social isolation caused by the COVID-19 pandemic on gaseous air pollutant concentrations. For this purpose, the authors presented (thermal maps) and analyzed the concentrations of selected gases such as NO2, CO, SO2, and PM2.5 particles during the strict quarantine period in Poland and other EU countries. Statistical analysis of the concentration level of these gases was performed. It was noticed that in Poland, Germany, and France, the concentrations of such gases as CO, NO2, and PM2.5 particles decreased, while in Italy and Spain, the tendency was the opposite. To verify whether the discovered dependencies are not a natural continuation of the trends shaping the given phenomenon, the time series of gas and PM2.5 particle emissions were analyzed. On this basis, the emission forecast up to 2023 was created, using the ARIMA class models. The obtained results allowed to construct five scenarios for the development of NO2, CO, SO2, and PM2.5 emissions until 2023, considering the impact of the COVID-19 pandemic. It was stated that in the optimistic scenario, in 2023, a decrease in CO, NO2, and PM2.5 emissions could be achieved by maximums of 51%, 95%, and 28%, respectively

    Characteristics of Some Selected Methods of Rare Earth Elements Recovery from Coal Fly Ashes

    No full text
    The article covers the issues related to the characteristics, application, and some methods of rare earth elements (REEs) recovery from coal fly ashes. REEs are elements with growing demand and a very wide range of application, especially when it comes to modern technologies. The conducted analysis and price forecast proved the existing upward tendency, and this confirmed the need to search for new REE sources, among industrial waste (proecological effect). The development of the REE recovery technology would involve solving several problems related to REE speciation, optimization of factors controlling their extractivity and selection of the REE separation method from obtained extraction solutions with a very extreme pH and complicated composition. The paper presented advantages and disadvantages of usually used methods of REE separation from coal fly ashes, like physical and acid&ndash;base leaching. It was also presented alternative REE recovery techniques in the form of membrane and biological methods and based on ion liquids (ILs) or chelating agents. The directions of further modifications, which will allow the efficient REE recovery were presented. The aim of this article was to propose specific solutions based on the creation of appropriate multistage method of REE recovery. It will be a combination of magnetic and size separation, acid&ndash;base leaching (including roasting in justified cases), removal of matrix elements with ILs (Al, Si, and Fe), and finally REE membrane separation, allowing one to obtain the appropriate process efficiency

    Modeling of Gas Permeation through Mixed-Matrix Membranes Using Novel Computer Application MOT

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    The following article proposes a modern computer application MOT (Membrane Optimization Tool) for modeling of gas transport processes through mixed-matrix membranes (MMMs). The current version of the application is based on the Maxwell model, which can be successfully used to model gas transport through the simplest types of hybrid membranes without any defects. The application has been verified on the example of four types of hybrid membranes, consisting of various types of polymer matrix, such as: poly (vinyl acetate), 2, 2&prime;-BAPB + BPADA, Ultem, hyperbranched polyimide (ODPA-MTA) and zeolite 4A. The average absolute relative error (AARE) and root-mean-square error (RMSE) were calculated in order to compare the theoretical MOT-predicted results with the experimental results. It was found that the AARE ranges from 29% to 36%, while the RMSE is in the range of 10% to 29%. The article presents also the comparison of MOT-predicted data obtained with Maxwell and Bruggeman models. To obtain more accurate reproduction of experimental results, further versions of the proposed application will be extended with next-generation permeation models (Lewis&ndash;Nielsen, Pal, modified Maxwell or Felske models), allowing for the description of transport in more complex systems with the possibility of taking into account possible defects
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