91 research outputs found

    Temporal and spatiotemporal autocorrelation of daily concentrations of Alnus, Betula, and Corylus pollen in Poland

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    The aim of the study was to determine the characteristics of temporal and space–time autocorrelation of pollen counts of Alnus, Betula, and Corylus in the air of eight cities in Poland. Daily average pollen concentrations were monitored over 8 years (2001–2005 and 2009–2011) using Hirst-designed volumetric spore traps. The spatial and temporal coherence of data was investigated using the autocorrelation and cross-correlation functions. The calculation and mathematical modelling of 61 correlograms were performed for up to 25 days back. The study revealed an association between temporal variations in Alnus, Betula, and Corylus pollen counts in Poland and three main groups of factors such as: (1) air mass exchange after the passage of a single weather front (30–40 % of pollen count variation); (2) long-lasting factors (50–60 %); and (3) random factors, including diurnal variations and measurements errors (10 %). These results can help to improve the quality of forecasting models

    Oak pollen in the air of Poland in 2017

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    The aim of the study was to compare the pollen season of oak in the cities of Bialystok, Bydgoszcz, Cracow, Katowice, Piotrkow Trybunalski, Lublin, Olsztyn, Opole, Szczecin, Warsaw, Wroclaw and Zielona Gora in 2017. Measurements were performed by the volumetric method (Hirst type pollen sampler). Seasonal Pollen Index (SPI) was estimated as the sum of daily average pollen concentrations in the given season. Pollen season was defined as the period in which 98% of the annual total catch occurred. The pollen season of oak started first in Szczecin, on the 1st April, and lasted till the end of May. At the latest pollen season ended in Olsztyn on the 1st June. However, in the most of other cities the season lasted till the end of May. The differences of pollen seasons duration were considerables from 28 to 56 days. The highest, record airborne concentration of 342 pollen grains/m3 was noted in Warsaw on the 17th May. The maximum values of seasonal pollen count occurred between of 11th and 20th May. The highest oak pollen allergen hazard occurred in 2017 in Piotrkow Trybunalski, Lublin and Warsaw

    Extension of WRF-Chem for birch pollen modelling – a case study for Poland.

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    In recent years, allergies due to airborne pollen have shown an increasing trend, along with the severity of allergic symptoms in most industrialised countries, while synergism with other common atmospheric pollutants has also been identified as affecting the overall quality of citizenly’ life. In this study we propose the state-of-the-art WRF-Chem model, which is a complex Eulerian meteorological model integrated on-line with atmospheric chemistry. We used a combination of the WRF-Chem extended towards birch pollen, and the emission module based on heating degree days, which has not been tested before. The simulations were run for the moderate season in terms of birch pollen concentrations (year 2015) and high season (year 2016) over Central Europe, which were validated against 11 observational stations located in Poland. The results show that there is a big difference in the model’s performance for the two modelled years. In general, the model overestimates birch pollen concentrations for the moderate season and highly underestimates birch pollen concentrations for the year 2016. The model was able to predict birch pollen concentrations for first allergy symptoms (above 20 pollen m-3) as well as for severe symptoms (above 90 pollen m-3) with Probability of Detection at 0.78 and 0.68 and Success Ratio at 0.75 and 0.57, respectively for the year 2015. However, the model failed to reproduce these parameters for the year 2016. The results indicate the potential role of correcting the total seasonal pollen emission in improving the model’s performance, especially for specific years in terms of pollen productivity. The application of chemical transport models such as WRF-Chem for pollen modelling provides a great opportunity for simultaneous simulations of chemical air pollution and allergic pollen with one goal, which is a step forward for studying and understanding the co-exposure of these particles in the air

    Hydroxyapatite scaffolds by “Robocasting” for medical applications – preliminary tests

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    Artykuł prezentuje wyniki wstępnych badań przeprowadzonych na przestrzennych porowatych strukturach bioceramicznych - rusztowaniach hydroksyapatytowych - wykonanych metodą „Robocasting”. Badaniom poddano próbki o różnych wariantach geometrii strukturalnej przy zachowaniu tych samych wymiarów zewnętrznych. Własności wytrzymałościowe wyznaczono w próbie trójpunktowego zginania. Złożoną mikro i makro strukturę pokazano na zdjęciach wykonanych przy użyciu mikroskopu skaningowego i optycznego. Wykonano testy w środowisku SBF. Analiza wyników pokazała, że pomimo niskich własności wytrzymałościowych drukowane struktury przestrzenne mogą służyć do zastosowań medycznych. Wystarczająca sztywność, odpowiednia porowatość, a także biozgodność, pozwala na ich zastosowanie jako rusztowań dla komórek – skafoldów.Preliminary results on three-dimensional porous bioceramic structures - hydroxyapatite scaffolds - are presented in this article. “Robocasting” was used as a fabrication method. Sets of prepared samples had the same outer diameter but different structure of macroporosity. 3-pts bending test was applied to reveal mechanical properties. Optical microscope and scanning electron microscope (SEM) pictures were taken for structural analysis of printed and sintered samples. Biological activity was tested in simulated body fluid (SBF). Analyses show that low mechanical properties of three-dimensional porous structures are not decisive and do not exclude such structures from medical applications. Sufficient stiffness, appropriate porosity and biocompatibility allow using them as scaffolds for bone cells growth

    Strength and strain analysis of gradient biomaterials assigned for medical implants

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    W pracy autorzy przedstawiają analizę wytrzymałościową i odkształceniową kompozytów gradientowych z kontrolowaną zmianą modułu Younga w warunkach symulowanego środowiska biologicznego. Zaprojektowane przy pomocy MES pięciowarstwowe kompozyty z PSU/CF 1D z gradientem otrzymanym poprzez zmianę udziału procentowego włókien (10, 15, 20, 30, 40%) po wstępnych testach wytrzymałościowych i odkształceniowych zostały umieszczone w płynie Ringera pod działaniem stałego obciążenia siłą P=1200N przez okres 56 dni. Co 14 dni wykonywano pomiary ultradźwiękowe, po okresie inkubacji próbki poddano badaniom wytrzymałościowym do 5000 N. Wyniki pomiarów wykazują przydatność materiału gradientowego PSU/CF 1D jako implantów dokręgosłupowych ze względu na ich dobrze dopasowany moduł Younga i odkształcalność do naturalnego krążka międzykręgowego człowieka. W kolejnym etapie badań zostanie wykonana analiza zmęczeniowa materiałów w celu określenia ich trwałości.In this article strength and strain analysis of gradient composites with controlled change of Young’s modulus in simulated biological environment was presented. Polysulfon/carbon fibers (PSU/CF) 1D composites with gradient of the content of PSU to CF (10, 15, 20, 30, 40 wt% of CF), built up of 5 layers were designed by using FEM. After preliminary strength and strain tests they were incubated in Ringer’s under the static load P=1200 N solution for 56 days. Ultrasonic measurements were made every 14 days. After incubation samples mechanical strength was tested with the load up to 5000 N. The obtained results show suitability of PSU/CF 1D gradient material for spine implants because of well – matched Young’s modulus and deformability to natural human intervertebral disc. As a next step of the research fatigue testing analysis will be done, in order to obtain materials’ durability

    Model struktury pojazdów samochodowych dla kryterium poziomu technicznego ze względu na emisję zanieczyszczeń

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    Inventory of total vehicle pollution emission is only possible through the use of emission modelling. One of the most difficult problems in modelling total emission from motor vehicles is the identification of the structure of vehicle fleet. While it is possible to use vehicle registration data to model the numerosity of elementary vehicle categories, it is very difficult to design representative driving cycles for vehicles in separate categories, in the absence of empirical evidence. The article proposes two models of the structure of motor vehicles for the criterion of technical level on account of pollutant emission. The method of modelling the intensity of use of motor vehicles by elementary categories on account of pollutant emission, outlined in this article, is the first unique undertaking in this field on a global scale. This method was used for inventorying pollutant emission from motor vehicles in Poland, in the years 2000–2015.Inwentaryzacja całkowitej emisji zanieczyszczeń samochodowych jest możliwa tylko dzięki zastosowania modelowania emisji zanieczyszczeń. Jednym z najtrudniejszych problemów modelowania całkowitej emisji zanieczyszczeń z pojazdów samochodowych jest identyfikacja ich struktury. O ile jest możliwe wykorzystanie danych związanych z rejestracją pojazdów samochodowych do modelowania liczności kategorii pojazdów samochodowych, o tyle wyznaczenie reprezentatywnych przebiegów pojazdów elementarnych kategorii jest zadaniem bardzo trudnym ze względu na brak wyników badań empirycznych. W artykule zaproponowano dwa modele struktury pojazdów samochodowych dla kryterium poziomu technicznego ze względu na emisję zanieczyszczeń. Przedstawiony w niniejszym artykule sposób modelowania intensywności użytkowania pojazdów samochodowych kategorii elementarnych ze względu na emisję zanieczyszczeń jest pierwszym unikatowym przedsięwzięciem w tym zakresie w skali światowej. Metodę tę zastosowano do inwentaryzacji zanieczyszczeń pojazdów samochodowych w Polsce w latach 2000–2015
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