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No description available.

På senare tid har mikroplaster i hav och sjöar uppmärksammats som ett potentiellt stortmiljöproblem. Idag finns mikroplaster spridda över hela världens vatten från polerna till ekvatorn.År 2016 uppmärksammades konstgräsplaner som den nästa största källan till spridning avmikroplaster till sjöar och vattendrag i Sverige [1]. Fotboll är Sveriges nationalsport och är densporten som står för flest aktivitetstimmar i Sverige. Konstgräs har gjort det möjligt för fler barnoch ungdomar att få fler speltimmar och idag spelar 90 % av alla fotbollsspelare på konstgräs [2].De olika spridningsvägarna för mikroplaster från konstgräsplaner undersöktes med fokus påspridningsvägen via dagvatten. Det finns fler olika reningsmetoder för dagvatten innehållandemikroplaster, en av dessa är granulatfällan, en filterpåse som placeras i en dagvattenbrunn för attfånga upp granulat och konstgräsfibrer som sprids från konstgräsplanen till dagvattenbrunnen.Syftet med denna studie var att optimera reningsmetoden granulatfälla utifrån möjligavattenflöden och dess effektivitet i att fånga upp mikroplaster. Detta undersöktes genomframtagandet av en vattenflödesmodell vid konstgräsplaner med variationer i konstruktion ochgenom fältstudier av granulatfällans effektivitet vid två konstgräsplaner i Storstockholm.Det regn som undersöktes i vattenflödesmodellen var extremregn för ett 10 års regn under 10minuter. Detta för att hitta det maximala flöde granulatfällorna kommer behöva klara av. Vilkavattenflöden som nådde dagvattenbrunnarna var beroende på antalet dagvattenbrunnarplacerade runt konstgräsplanen, i vilket område i Sverige som konstgräsplanen var placerad, detvill säga hur mycket regn som kom, och konstgräsplanens infiltrationsförmåga.Vattenflödesmodellen fungerar som en mall för möjliga vattenflöden vid en specifik plats i Sverigeoch en viss konstruktion av konstgräsplan.De konstgräsplaner som var med i fältstudierna var Skytteholms IP i Solna och Spånga IP iStockholm. Vid varje konstgräsplan placerades 6 granulatfällor med två filterpåsar på varje fälla,den inre med större maskor och den yttre med mindre maskor. Kombinationerna var 200 μm med100 μm, 200 μm med 50 μm och 100 μm med 50 μm. Totalt fångades 10,3 kg mikroplast vidSkytteholms IP och 1,5 kg vid Spånga IP under de 49 dygn granulatfällorna var utplacerade. Avden totala mängden mikroplast viktmässigt i varje granulatfälla fanns minst 99 % i den inrefilterpåsen och maximalt 1 % i den yttre filterpåsen, det vill säga i storleksfraktionen mellan denyttre och den inre filterpåsen.Slutsatserna från denna studie är att vattenflödet till dagvattenbrunnarna placerade runtkonstgräsplaner kan variera mycket på grund av hur konstgräsplanen är konstruerad. Det berorframförallt på konstgräsplanens infiltrationsförmåga och antal dagvattenbrunnar runtkonstgräsplanen. Utifrån de teoretiska vattenflödena och fältstudierna rekommenderas att enfilterpåse med maskstorlek 200 μm används i granulatfällan. Detta utifrån att den inre filterpåsenfångade minst 99 % av de mikroplaster som nådde granulatfällorna, som var större än 50 μm, ochökad risk för igensättning och tillväxt av biofilm på filterpåsarna med mindre maskor. Vidarestudier bör genomföras på granulatfällans vattenflöde över tid, mikroplaster mindre än 50 μm,IIandra spridningsvägar för mikroplaster från konstgräsplaner, förbättrade konstruktioner avkonstgräsplaner och förbättrat underhållningsarbete för att minska spridningen av mikroplasterfrån konstgräsplaner. / In the recent years microplastics in the marine environment has been recognized as a potentiallyimportant environmental issue. Today there are microplastics spread in the waterbodies all overthe world, from the equator to the poles in south and north. In 2016 artificial turf was labeled thesecond largest source of microplastics to the marine environment in Sweden [1]. Football is thenational sport of Sweden and accounts for the majority of the activity hours among the youth inSweden. The artificial turf has made it possible for more children to play football and for them toget more hours on the field. Today about 90 % of the football players play on artificial turf [2].The microplastics pathways to the nature and the marine environment were studied andtreatment methods were developed. One of these methods is the so called granule trap, a filterbag which is placed in a stormwater drainage well to catch the rubber granulates and the artificialturf fibers which can be spread from the artificial field to the drainage system. The aim of thisstudy was to optimize the granule trap for possible waterflows to the stormwater drainage welland its efficiency to catch microplastics. This was researched through field studies of the efficiencyof the granule trap at two artificial turfs in Stockholm and the development of a waterflow modelof an artificial turf with varying construction.The rainfall which was used in the waterflow model was the 10-year storm with a duration of 10minutes. This to find the maximum waterflow the granuletraps must manage. The waterflows tothe stormwater drainage well were dependent on the number of wells placed around the artificialturf, in which area of Sweden the football field was placed, in other words the amount of rain thatfell, and the infiltration capacity of the artificial turf. The waterflow model works as a templatefor possible waterflows at an artificial turf with a certain construction and at a certain location inSweden.The artificial turfs which were examined in the field studies were Skytteholms IP in Solna andSpånga IP in Stockholm. At each football field 6 granuletraps were placed, each loaded with twofilter bags, the inner with larger sized mesh and the outer with smaller sized mesh. The mesh sizecombinations were 200 μm with 100 μm, 200 μm with 50 μm and 100 μm with 50 μm. atSkytteholms IP a total amount of 10.3 kg microplastics were caught and at Spånga IP a total of 1.5kg microplastics were caught during the 49 days the granuletraps were placed at the footballfields. Out of the total amount of microplastics in each granuletrap at least 99 % by mass was inthe inner filter bag and maximum 1 % by mass was in the outer filter bag, in the size fractionbetween the outer and the inner filter bag..In conclusion this study shows that the waterflow to the stormwater drainage wells placed aroundthe artificial turfs vary a lot depending on the construction of the artificial turf. Foremost itdepends on the infiltration capacity of the artificial turf and the number of stormwater drainagewells around the field. With regards to the waterflows from the waterflow model and the resultsfrom the field studies the recommended mesh size for the filter bags is 200 μm. This since at least99 % by mass of the microplastics, which were larger than 50 μm, that reached the granule trapsIVwere trapped in the inner filter bag and the elevated risk of clogging and biofilm growth on thefilter bags with smaller mesh size. Further studies should be conducted on the waterflow throughthe granuletraps over time, microplastics smaller than 50 μm, other pathways for themicroplastics away from the artificial turf, improved constructions of artificial turfs and improvedmaintenance on the artificial turfs to reduce the risk of spreading of microplastics from artificialturfs.

No description available.

Adjacent terrestrial habitat surrounding wetlands are critical for the survival and success of many species that use them. The primary purpose of this study was to determine amphibian movement from adjacent habitats into Orchard Bog, a restored bog located in Shady Valley, Johnson County, Tennessee. In addition, a secondary bog, Quarry Bog, was also studied determining baseline presence/absence data A total of 16 species from six families were observed throughout the study sites. Seven species of anurans, Bufonidae, Hylidae, and Ranidae and nine species of caudates in the families Plethodontidae, Ambystomatidae and Salamandridae were identified. Fourteen of the 16 species were found within Orchard Bog. Data collected can be used to help determine more beneficial land acquisitions and management strategies. Survey methods included pitfall traps, funnel traps, coverboard arrays, and opportunistic surveys.

This thesis addresses the issue of the time variability of the fine structure constant, alpha. Recent claims of a varying alpha are set against the established standards of quantum electrodynamical theory and experiments. A study of the feasibility of extracting data on the time dependence of alpha using particles in Penning traps is compared to the results obtained by existing methods, including those using astrophysical data and those obtained in atomic clock experiments. Suggestions are made on the nature of trapped particles and the trapping fields.

We demonstrate an optical method to detect calcium ions in an ultracold plasma. We probe the plasma with a 397 nm laser beam tuned to a calcium ion transition. The probe laser beam is focused to a 160 µm waist allowing fine spatial resolution. Ions are detected by measuring fluorescence using a Photo-Multiplier Tube (PMT). The signal, an average of 4000 acquisitions, has a temporal resolution of 120 ns. We present the details of this method, potential improvements, and prospects of imaging the expanding plasma ions. We also present preliminary work on spatially resolved absorption measurements, as well as additional studies.

The electrostatic ion beam trap (EIBT) was designed by D. Zajfman during the previous decade. This ion trap combines many properties of the Fourier-transform ion cyclotron resonance (FTICR) mass analyzer and time-of-flight (TOF) mass analyzer. There are several advantages for the electrostatic ion beam trap. First, large mass-to-charge particles in an electrostatic field could be easier to analyze. Second, there is a folded flight path, which could make the mass analyzer smaller compared to conventional TOF mass analyzer. This principle of operation of this ion trap is analogous to an optical resonator. The ions are trapped in a voltage valley and oscillate between the two parallel sets of mirror electrodes with high voltages. In this thesis, I first describe a new type of miniaturized electrostatic ion beam trap mass analyzer that consists of two printed circuit boards (PCBs). The facing surfaces of these boards are imprinted with copper electrodes. The center of the boards is field free and at ground potential with ion mirrors and Einzel lenses on either side. A charge detector is attached to the center for recording the time-dependant motion of the ions in the field. The PCB-based EIBT design is easier to construct than the original EIBT mass analyzer. The electrostatic fields are optimized by adjusting the potential on the mirror electrodes as well as the geometry of the electrodes. Although nondestructive charge detection is much less sensitive for small ions, this detection is ideal for analysis of large ions. The planar electrostatic ion beam trap is inexpensive, small, and simple to operate. The PCB EIBT device was designed, built, and tested using metal samples such as copper and nickel. The electric field of the PCB EIBT is not the same as that of the original EIBT. Unfortunately, there were no ion signals captured in image charge detector. Another new type of miniaturized electrostatic ion beam trap was made by depositing electrodes onto Kapton film. Seven thin tin/copper traces (1 mm wide by 0.015 mm thick) were deposited onto each side of a flat, flexible circuit board substrate (Kapton film 0.15 mm thickness). The film was rolled to form a cylinder. The flexible EIBT is small (4.5 cm × 8 cm), and lightweight (~1 g). This device was tested using laser ablation of CsI. The CsI signals were detected by the charge detector, amplified and sent to the oscilloscope. Fourier transformation was used to convert the data to the frequency domain spectrum. The resolution of Cs+ is around 1000 (m/Δm) from initial flexible EIBT test. The mass accuracy of the Cs+ peak is better than 0.1%.

No description available.

Excavations at Natural Trap Cave (NTC) began in the mid-1970's and quickly yielded evidence of a diverse steppe fauna that existed during the Last Glacial Maximum (MIS 2) along the western slope of the Bighorn Mountains in north central Wyoming. NTC is a karst pit cave with a 24.5 m vertical drop into a roughly 43 m wide bell-shaped ‘Main Chamber’ and during the course of early excavations a plugged entrance to a fossil-bearing ‘Lower Chamber’ was discovered. Stratigraphic relationships below the entrance to the Main Chamber of the cave were originally studied in the mid-1970's, but were never formally published. Although stratigraphy, taphonomy, and depositional circumstances were briefly discussed over the following years, little has been done to correlate the numerous stratigraphic schemes used by various authors. In this study, four stratigraphic sections were measured and analyzed to establish an easily modifiable lithostratigraphic system of nomenclature. We provide the first correlations of all stratigraphic nomenclature used throughout excavations at NTC to facilitate comparisons with current and previous collections and publications. By leveraging more than 100 radioisotopic dates we developed an age-depth model and chronostratigraphic framework to further interrogate spatiotemporal relationships between strata, paleoenvironmental proxies, and fossil assemblages. Deposition is shown to be discontinuous; sediment accumulation in the study area is restricted to the buildup through peak penultimate and Last Glacial maxima. More recent (<10 ka) Holocene deposits unconformably cover the eroded surface of underlying Pleistocene strata. There is active reworking of sediments with transport and deposition of reactivated material within the Lower Chamber. We note that the two hiatuses coincide with interglacial periods and may reflect changing depositional circumstances within the cave such as extended periods of non-deposition, erosion, or bypass (possibly leading to deposition in the Lower Chamber). Contrary to previous reports, we demonstrate that it is unlikely a prominent snow cone existed or contributed to the pattern of sediment and fossil distribution within the study area, furthermore, we do not observe a continuous Pleistocene-Holocene transition in the study area. Further stratigraphic work will be needed to better understand the interrelationship between Main and Lower chamber deposits and the evolution of sediment accumulation in NTC.