16 research outputs found

    Magyarországi utcai hosszútávfutó versenyek tendenciájának elemzése részvételi szám és teljesítmény szempontjából (1984 és 2020 között)

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    Jelen tanulmány célja a legnagyobb magyarországi utcai hosszútávfutó versenyek trendjeinek elemzése volt, létszám, nemek, eredmények és nemzetiség szerint. Az összes eddig megrendezett Budapest Maraton (1984-2020); Budapest Félmaraton (1991-2020) és Vivicitta Félmaraton (2011-2019) adatait töltöttük le a Budapest Sportiroda weboldaláról (N=70). Mindhárom verseny esetében szignifikáns növekedés volt tapasztalható a versenyt teljesítő összes versenyző, férfiak, nők és külföldi futók számát tekintve az évek során (p<0,05). A részvételi számban megjelenő növekedés nem okozott növekedést a teljesítményben. A félmaraton versenyszámok több versenyzőt produkáltak, a nők aránya is magasabb volt. A külföldiek aránya a Budapest Maraton során szignifikánsan magasabb volt a félmaraton versenyekhez képest, azonban a külföldi futók számában nem volt jelentős különbség. Mindhárom verseny esetében több férfi versenyző indult, mint nő, valamint több hazai futó, mint külföldi. A hazai utcai hosszútávfutó versenyeket teljesítők ugrásszerű számbeli növekedése elsősorban a nők, és a rekreációs futók részvételének köszönhető. Felvetődik a kérdés, hogy mi okozza ezt a megnövekedett motivációt a hosszútávfutó versenyek iránt

    Monitoring the degradation of partly decomposable plastic foils

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    Abstract We have monitored the behaviour of different polyethylene foils including virgin medium density polyethylene (MDPE), MDPE containing pro-oxydative additives (238, 242) and MDPE with pro-oxydative additives and thermoplastic starch (297) in the soil for a period of one year. A foil based on a blend of polyester and polylactic acid (BASF Ecovio) served as degradable control. The experiment was carried out by weekly measurements of conductivity and capacity of the soil, since the setup was analogous to a condenser, of which the insulating layer was the foil itself. The twelve replications allowed monthly sampling; the specimen taken out from the soil each month were tested visually for thickness, mechanical properties, morphological and structural changes, and molecular mass. Based on the obtained capacity values, we found that among the polyethylene foils, the one that contained thermoplastic starch extenuated the most. This foil had the greatest decrease in tensile strength and elongation at break due to the presence of thermoplastic starch. The starch can completely degrade in the soil; thus, the foil had cracks and pores. The polyethylene foils that contained pro-oxydant additives showed smaller external change compared to the virgin foil, since there was no available UV radiation and oxygen for their degradation. The smallest change occurred in the virgin polyethylene foil. Among the five examined samples, the commercially available BASF foil showed the largest extenuation and external change, and it deteriorated the most in the soil.</jats:p

    Behavior of Polyethylene Films in Soil

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    A true-to life experiment on the behaviour of polyethylene films in soil was carried out. Commercial middle density polyethylene (MDPE) film, MDPE films containing pro-oxidative additives and thermoplastic starch and a commercially available biodegradable film (Ecovio, BASF) have been buried in soil and monitored monthly for one year. Bags made out of the films were filled with and surrounded with brown forest soil and electrodes were put into the soil inside the bag and into the soil surrounding the bag. The soil served as capacitor. Degradation could be monitored weekly by measuring the capacity and conductivity of the soil without removing the bags from it. Visual, mechanical (Instron), structural (FTIR, ESR) and morphological (POM, SEM) changes in the films and the change in molecular mass were tested monthly. The polyethylene films suffered only some physical degradation and not biodegradation. Our life-like experiments suggest that biopacking will be the future of plastics waste disposal

    Effect of Composting on the Behavior of Polyolefin Films - A True-to-Life Experiment

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    Commercial polypropylene (PP), high-, medium- and low density polyethylene (HDPE, MDPE, LDPE) films, as well as MDPE films containing pro-oxidative additives and thermoplastic starch (TPS) were composted for six weeks together with biologically degradable films, such as poly (lactic acid) (PLA), Ecovio (BASF), Mater Bi(Novamont) and cellophane. Visual appearance of the polyolefin-based films did not change significantly, while the biologically degradable films fell apart. Thickness and mechanical properties of the polyolefin-based films also did not vary significantly after composting. The thickness of the degradable films however increased due to biofilm formation and finally decreased due to biodegradation, and their mechanical properties drastically dropped. FTIR proved the formation of carbonyl absorption of commercial and of the additive-containing films respectively) after composting due to oxidation. The FTIR-spectrum of the biodegradable films showed drastic change after composting. Formation of free radicals was detectable by ESR-spectroscopy, if pro-oxidative additive containing MDPE film was exposed for one week to sunlight, and the intensity of free radical formation increased after composting. The number-average molecular mass of MDPE films containing pro-oxidative additives decreased, low molecular mass fractions appeared and polydispersity increased after composting. Commercial polyolefin films were covered by microorganisms much more densly than films containing pro-oxidative additives detected by SEM. Even TPS did not increase the quantity of microorganisms. Biodegradable films were densly covered by microorganisms of different types and they became porous and holes were observable on their surface. It can be concluded that composting had no significant effect on the behaviour of the commercial PP and PE films. Signs of initial degradation were observable on MDPE films with pro-oxidative additives and TPS after 6 weeks composting, although it cannot be considered as biological degradation. Non of the tested polyolefin films suffered such degree of degradation in compost, as the biologically degradable films. It may be concluded that polyolefin films neither degrade in compost nor they undergo biodegradation

    Behavior of Polyethylene Films in Soil

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    A true-to life experiment on the behaviour of polyethylene films in soil was carried out. Commercial middle density polyethylene (MDPE) film, MDPE films containing pro-oxidative additives and thermoplastic starch and a commercially available biodegradable film (Ecovio, BASF) have been buried in soil and monitored monthly for one year. Bags made out of the films were filled with and surrounded with brown forest soil and electrodes were put into the soil inside the bag and into the soil surrounding the bag. The soil served as capacitor. Degradation could be monitored weekly by measuring the capacity and conductivity of the soil without removing the bags from it. Visual, mechanical (Instron), structural (FTIR, ESR) and morphological (POM, SEM) changes in the films and the change in molecular mass were tested monthly. The polyethylene films suffered only some physical degradation and not biodegradation. Our life-like experiments suggest that biopacking will be the future of plastics waste disposal

    Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions

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    Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6–20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11 338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale
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