Cryogenic recovery of tire rubber.

A comprehensive investigation of the cryogenic recovery of tire rubber was conducted with laboratory, pilot plant and industrial equipment. Experiments were conducted with specimens of tire rubber to determine cooling curves for: (1) Scrap tire rubber dipped in liquid nitrogen. (2) Scrap tire rubber cooled by nitrogen vapour. (3) Virgin tire rubber dipped in liquid nitrogen. (4) Different size cubes of tire rubber cooled simultaneously by nitrogen vapour. (5) Tire rubber cooled and then recooled to investigate material degradation. Electron microphotographs of scrap and virgin tire treads were compared in terms of physical characteristics. The used tire rubber specimen appeared to have a granular structure. Air trapped in the interstices hindered the heat transfer process. On the other hand, the virgin tire specimen appeared to be homogeneous. This structure enabled the virgin material to cool at a higher rate. Electron photomicrographs of ambiently and cryogenically ground rubber crumbs were also compared. The ambiently ground rubber displayed more surface area than the cryogenically ground material. This increase was created by the torn edges of the ambiently ground rubber. The faceted surfaces of the cryogenically processed rubber provide smoother surfaces of lower area. Experimental and theoretical data were used to design a small fine-grind system which was proposed for the processing of ${3\over 8}$ inch pellets of tire rubber to a fine size less than 30 mesh. When frozen tire chips are passed through a hammermill, an entanglement of steel and nylon fibre results. Separation of this entanglement by various means was thoroughly investigated. Theoretical and experimental data were applied to the modifications of the industrial-size plant in Cambridge, Ontario. The improvements to the industrial system made it more efficient. A number of recommendations have been made for continuation of this basic investigation. (Abstract shortened by UMI.)Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1993 .M271. Source: Masters Abstracts International, Volume: 33-04, page: 1278. Adviser: Alex W. Gnyp. Thesis (M.Sc.A.)--University of Windsor (Canada), 1993

Natural history and morphometry of the Cuban iguana (Cyclura nubila Gray, 1831) in Cayo Sijú, Cuba

The report presents data about the Cuban iguana population (Cyclura nubila nubila) inhabiting Cayo Sijú, an 88 ha island off the southwest coast of Cuba. Population densities estimated using strip transects were higher in xerophytic coastal scrub (6.72 ± 6.25 iguanas/ha) than in typical sand vegetation (3.63 ± 2.71 iguanas/ha) and mangrove forests (2.9 ± 2.9 iguanas/ha). The total population for the cay was estimated at 350 individuals with an adult biomass of approximately 11.67 kg/ha. Densities varied minimally between three habitat types and between the wet and dry seasons. No significant density fluctuations were found one month after Hurricane Ivan affected the cay. Iguana burrows were encountered most frequently in beach dunes. Analysis of 30 scat samples revealed eight species of plants, with the fruits of Chrysobalanum icaco and the leaves of Batis maritima being the most frequently identified items. The remains of crab (Cardisoma guandhumi) and insects of the order Hemiptera were also present in scat samples. Sexual dimorphism was evident in this population, with males being significantly larger in eight morphological variables. The snout-vent length measurements were larger in this population than in those reported in two cays off the south coast of Cuba

Enhanced Starting Track Real-time Stream for IceCube

IceCube real-time alerts allow for rapid follow-up observations of likely astrophysical neutrino events, enabling searches for multi-messenger counterparts. The Enhanced Starting Track Real-time Stream (ESTReS) is a real-time extension of the Enhanced Starting Track Event Selection (ESTES), a high astrophysical purity muon-neutrino sample recently used by IceCube to measure the astrophysical diffuse flux. A set of computationally cheap cuts allows us to run a fast filter in seconds. This online filter selects about 100 events per day to be sent to Madison, WI via satellite where the full ESTES event selection is applied within minutes. Events that pass the final set of cuts (ESTReS + ESTES) will be sent out as real-time alerts to the broader astrophysical community. ESTReS's unique contribution to the current real-time alerts will be events in the southern sky in the 5 TeV - 100 TeV range. We expect about 10.3 events per year which average 50% astrophysical purity. In this talk I will report the status of the ESTReS alert stream in the context of the IceCube real-time program.Comment: Presented at the 38th International Cosmic Ray Conference (ICRC2023). See arXiv:2307.13047 for all IceCube contribution

Sentinel of the extraordinary: the IceCube alert system for neutrino flares

The IceCube Neutrino Observatory has the invaluable capability of continuously monitoring the whole sky. This has affirmed the role of IceCube as a sentinel, providing real-time alerts to the astrophysical community on the detection of high-energy neutrinos and neutrino flares from a variety of astrophysical sources. As a response to the IceCube alerts, different observatories can join forces in the multi-messenger observation of transient events and the characterisation of their astrophysical sources. The 2017 breakthrough identification of blazar TXS 0506+056 as the source of high-energy neutrinos and UHE gamma rays was proof of this strategy. The Gamma-ray Follow-Up (GFU) is the IceCube program for identifying high-energy muon neutrino single events, as well as outstanding neutrino flares from relevant sources and the whole wide universe. While the identification of single high-energy neutrinos is shared on public alert distribution networks, partner Imaging Air Cherenkov Telescopes are sent low-latency alerts following the detection of neutrino flares, for which they have dedicated follow-up programs. I will present an overview of the GFU platform together with new results from the analysis of recorded neutrino flares, after a dozen years of GFU operation and hundreds of alerts being sent.Comment: Presented at the 38th International Cosmic Ray Conference (ICRC2023). See arXiv:2307.13047 for all IceCube contributions. 11 pages and 6 figure

Tamaño relativo del cerebro en murciélagos cubanos

Se estudia el tamaño relativo del cerebro en 22 especies de murciélagos cubanos, incluidos en seis familias: Phyllostomidae (siete), Mormoopidae (cuatro), Natalidae (una), Noctilionidae (cuatro), Vespertilionidae (cuatro) y Molossidae (cinco). Se incluyeron todos los géneros (19) presentes en el Archipiélago cubano con la excepción de Anthrozous. El exponente alométrico que describe la relación entre el volumen endocraneal y la masa corporal es considerablemente más alto que el hallado en estudios anteriores sobre el orden Chiroptera. Los filostómidos presentaron cerebros más grandes que otras especies de murciélagos insectívoros. Al examinar la relación del coeficiente de cefalización con diferentes estrategias en el uso del hábitat, se encontró la mayor relación cuando los murciélagos se agruparon de acuerdo al uso de los diferentes espacios alimentarios. El desarrollo endocraneal observado en la fauna de murciélagos de Cuba muestra la misma tendencia que en estudios previos: la utilización de hábitats y conductas más complejas determinan mayores volúmenes cerebrales.The relative brain size is described for 22 Cuban bats, seven species from the Phyllostomidae, Mormoopidae (four species), Natalidae (one species), Vespertilionidae (four species), Noctilionidae (one species) and Molossidae (five species). This study included all genera (19) recorded in Cuba, with the exception of Anthrozous. The allometric exponent describing the functional trend between the endocranial volume (brain size) and body mass, is considerably highest than the exponent value found in previous studies in Chiroptera. The phyllostomids had significantly larger brains that insectivorous species. When examining the relationship of the encephalization quotients with different strategies in the use of the habitat, it was the highest when the bats were grouped according to their foraging strategies. The endocraneal development observed in the cuban bats shows the same tendency that in previous studies of the order Chiroptera: the use of complex foraging strategy is associated with increased relative brain size

Valoración rápida de la biodiversidad en cayos al sureste de la Ciénaga de Zapata (Cuba)

Se realizó una valoración rápida de la biodiversidad en cayos y algunas zonas costeras al sureste de la Reserva de la Biosfera Ciénaga de Zapata, importante zona biodiversa de Cuba y la región caribeña. Se efectuaron dos expediciones de 6 y 9 días en el primer trimestre de 2004 para inventariar las especies que constituyen su flora y fauna (especialmente de vertebrados terrestres). Se detectaron 165 especies de plantas con flores (10 taxones endémicos), pertenecientes a 133 géneros y 64 familias. En lo concerniente a vertebrados se observaron 61 especies (8 especies endémicas): 5 mamíferos (incluyendo una especie invasora, Rattus rattus), 42 aves, 13 reptiles y un teleósteo de aguas interiores. Se comentan los impactos que están afectando actualmente a la biodiversidad de la zona. Los datos obtenidos serán de utilidad para la elaboración de posibles planes de manejos y de conservación en esta zona protegida.We carried out a rapid assessment of the biodiversity in some keys and adjacent coastal zones Southeast Ciénaga de Zapata Biosphere Reserve. This area constitutes an important biodiverse zone of Cuba and the Caribbean region. In order to prepare an inventory of its flora and fauna (especially terrestrial vertebrates), two expeditions of six and nine days were done between January and March of 2004. We detected 165 species of flowering plants (10 endemic taxa), belonging to 133 genus and 64 families. As for vertebrates, we observed 61 species (8 endemic species): 5 mammals (including an invasive species, Rattus rattus), 42 birds, 13 reptiles, and one freshwater teleost species. The impacts that are affecting the biodiversity of the zone are commented. This information will be useful to elaborate possible plans of management and conservation of this protected area