Mechanical and Tribological Properties of Composites of Recycled High Density Polyethylene and Recycled Rubber

This thesis presents a study on the mechanical and tribological properties of composite materials of recycled high density polyethylene (HDPE) and recycled rubber tire particles. The materials were compounded by extrusion and formed into test specimens by injection molding. The first experiment studied the effect of recycled rubber percentage on mechanical properties of composites of recycled HDPE and recycled rubber. The mechanical properties included tensile strength, percent elongation, hardness, and impact resistance. Recycled rubber concentrations of 0, 5, 10, 15, 20, 25, and 30 percent were tested. The second experiment investigated the tribological properties of recycled HDPE and recycled rubber composites. Tests were performed on the composite specimens to determine the effects of normal pressure, sliding speed, and recycled rubber percentage on coefficient of friction and wear rate. Normal pressure in the range in the range between 9.87 and 24.60 MPa was applied on specimens containing five percent recycled rubber at a sliding speed of 5.10 m s-1. Sliding speed between 2.55 and 5.95 m s-1 was studied on specimens containing five percent recycled rubber at a normal pressure of 16.46 MPa. Rubber percentages of 0, 5, 10, 15, 20, 25, and 30 percent were tested at a normal pressure of 16.46 MPa and a sliding speed of 5.10 m s-1. Tensile strength decreased as recycled rubber percentage increased for the composites of recycled high density polyethylene and recycled rubber particles. The ductility of the composites decreased drastically as recycled rubber content increased to five percent, and further decreased gradually from five to 30 percent. The hardness decreased as recycled rubber content increased. The impact strength decreased drastically at five percent recycled rubber. It remained fairly constant from five to 25 percent of recycled rubber, and then decreased as rubber content increased to 30 percent. The tribological experiments showed that coefficient of friction and wear rate increased as the normal pressure increased for the composite of recycled HDPE with five percent recycled rubber. Coefficient of friction and wear rate increased as the sliding speed increased for composites of recycled HDPE with five percent recycled rubber. Coefficient of friction and wear rate increased as the recycled rubber percentage increased in composites of recycled HDPE with recycled rubber. Microscopic analysis of the friction and wear test specimens was performed to determine structural changes due to sliding. The sliding surface and cross section of the tested specimen were examined. The results of this analysis showed that surface damage increased as normal pressure, sliding speed, or percentage of recycled rubber increased. The depth of deformation decreased as the sliding speed increased, while the depth increased with increasing normal pressure and rubber percentage

Navigating the Fourth Dimension: Nonlinear Narratives in Film, Literature, and Television

Time is often considered the fourth dimension due to the fact that nothing can exist outside the confines of time. Since time is so intrinsic to the very nature of being in the world, creators of film, literature, and television, which are reflective of life, must at least implicitly confront concepts of time and temporality within their work. The intangibility of time presents many difficulties but also a great number of opportunities in accurately portraying its true function within the world. Many literary works, films, and television programs directly confront concepts of time. Each medium with its own benefits and detriments must approach time and its true representation differently. Although authors and directors all must work within the same confines of their respective media, the approaches taken by different authors and directors are varied and widespread. These diverse approaches vary in their level of success and by which elements regarding the complexity of time they elucidate. It is this introspection into the complexity of time through literature, film, and television, which is the topic of my honors project. By reading novels and viewing films and television programs, which utilize nonlinear story telling techniques and analyzing these works, it is my hope to garner a greater understanding of how the complex nature and experience of time can be approached and re-presented through different media

Relative Effectiveness of Repellents for Preventing Deer Damage to Japanese Yews

Homeowners whose landscape plants are repeatedly browsed by white-tailed deer (Odocoileus virginianus) are interested in repellent products that are effective and long-lasting. New products come to market with limited experimental testing. We conducted a 10-week trial from Feb. through Apr. 1999 to test the duration and efficacy of six commercial deer repellents [Deer-Away Big Game Repellent (BGR) mix, BGR spray, Deer-Off, Deer Stopper II, Repellex, Tree Guard] and two experimental deer repellents (CU-A and CU-B) relative to each other and to untreated plants. Treated and control balled japanese yew (Taxus cuspidata) shrubs were placed at each of 10 homeowner sites with known white-tailed deer damage near Ithaca, NY. Yews are frequently eaten by deer during winter and provide a good bioassay for testing repellents, especially during the winter months. We checked shrubs once weekly and took photographs of damaged yews to measure the amount of deer browsing. We calculated the surface area of shrubs in each photograph by using digital analysis software. To determine significant differences over time, we applied statistical analysis using analysis of variance. Deer repellents that provided the most consistent protection were BGR spray, BGR mix, Deer-Off, and Deer Stopper II. The japanese pachysandra (Pachysandra terminalis) extracts in experimental repellents CU-A and CU-B were not effective. The performance of other commercial repellents varied considerably among sites, and these products were unreliable

Integrating Lethal and Nonlethal Approaches for Management of Suburban Deer

Evaluations of white-tailed deer (Odocoileus virginianus) population management in suburban landscapes has included debate over lethal control (e.g., sharp-shooting and hunting). These management techniques are often stymied by political impediments, safety concerns, and public attitudes. We are implementing the novel use of surgical sterilization in combination with hunting to mitigate deer-related impacts on Cornell University lands near Ithaca, New York. The project lands are composed of 2 zones: a suburban core campus area (446 ha) and adjacent outlying areas that contain agricultural fields and natural areas where deer hunting is permitted (582 ha). Surgical sterilization will be the primary technique used to reduce deer abundance and associated impacts in the core campus zone. Population reduction in the hunting zone will focus on increased harvest of female deer. During 2007 to 2009, project staff sterilized 58 female deer; 39 adult does were marked with radio transmitters to monitor movement and survival. Ten additional control deer have been captured and radio-collared for a comparison of fawning rates and survival. Hunters harvested 69 deer in the first hunting season (Fall 2008). In spring 2009, infrared-triggered cameras (IRCs) were used to estimate deer abundance in the sterilization zone, which resulted in a density of 21 deer/km2 (56 deer per square mile). In the hunting zone, deer populations will be monitored using a deer sighting log and by data collected at a mandatory deer check station. In both zones, ongoing deer browse and deer-vehicle accident (OVA) studies will ascertain changes in deer impacts throughout the study. Our goal is to determine if deer fertility control integrated with a controlled hunting program on adjacent lands can maximize the efficiency of both techniques. If this integrated management program is successful, it may have additional applications in other communities in New York State and the Northeast

Effects of Sample Disturbance and Consolidation Procedures on Cyclic Strengths of Intermediate Soils

Sampling and testing of soils to measure engineering properties, such as monotonic and cyclic undrained shear strengths, requires an understanding of the potential effects of sampling disturbance and the selection of appropriate laboratory testing procedures. For clays, past research has provided insights on how sampling methods and laboratory testing procedures can be used in practice to assess and minimize sample disturbance effects. For sands, past research has shown that conventional tube sampling techniques cause excessive disturbance to the soil fabric, such that subsequent measurement of monotonic or cyclic strengths can be greatly in error and misleading. For intermediate soils, the effects of disturbance and consolidation procedures on monotonic and cyclic strengths are not well understood. In the present study, a test protocol was developed to assess the effects that disturbance during sample extrusion, trimming, and mounting have on subsequent measurements of compressibility, monotonic undrained strength, and cyclic undrained strength. Detailed laboratory tests were performed on tube samples from deposits of low-plasticity silty clay, for which conventional sampling and testing were expected to work reasonably well, and low-plasticity clayey sand, for which the effects of sample disturbance were of primary concern. Test results using this protocol for these two soils are presented and discussed

Seasonal home ranges and habitat selection of three elk (Cervus elaphus) herds in North Dakota

Changes in land use have resulted in range shifts of many wildlife species, including those entering novel environments, resulting in the critical need to understand their spatial ecology to inform ecosystem effects and management decisions. Dispersing elk (Cervus elaphus) were colonizing areas of suitable habitat in the Northern Great Plains, USA, resulting in crop depredation complaints in these areas. Although state resource managers had little information on these elk herds, limited evidence suggested temporal movements into Canada. We collected and analyzed essential information on home range and habitat selection for 3 elk herds residing in North Dakota. We captured 5 adult female elk in each study area, affixed global positioning system collars, and monitored them for 1 year (2016–2017). We estimated diel period, seasonal, and hunting season home ranges using Brownian Bridge Movement Models for each individual. We analyzed habitat selection using multinomial logit models to test for differences in use of land classes, and for departures from proportionate use based on random sampling; our predictor variables included individual elk, diel period, and season. Home ranges differed between the 3 herds, seasons, and diel period; gun and winter season home ranges were both larger than in summer, as was night when compared with day. Female elk generally restricted themselves to cover during the day and entered open areas at night and during winter months. Our results also suggest that elk in our study areas tended to seek more cover, and in the case of our Turtle Mountain study area, some cross into Canada during gun season. Our study provides a better understanding of the spatial ecology of elk in the Northern Great Plains while highlighting the need for enhanced international cooperative management efforts

Measuring Bird Damage to Three Fruit Crops: A Comparison of Grower and Field Estimates

Birds are common pests in fruit orchards. They frequently consume and damage fruit resulting in decreased yields for growers. The true extent of damage is difficult to measure. Producer surveys are often implemented to estimate damage, but the accuracy of these estimates is uncertain. We compared damage estimates obtained through field studies with estimates from a producer survey for three fruit crops: wine grapes, sweet cherries, and ‘Honeycrisp’ apples. We also analyzed relationships between use of various damage management methods and levels of bird damage. We found wine grape and sweet cherry growers accurately assessed bird damage, while ‘Honeycrisp’ apple growers may overestimate damage. Growing region appears to be an important damage predictor for wine grape and sweet cherry crops. Significant relationships between management methods and damage were positive, suggesting growers only use these methods when bird damage is substantial

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Proportions of bird damage in tree fruits are higher in low-fruit-abundance contexts

Frugivorous birds impose significant costs on tree fruit growers through direct consumption of fruit and grower efforts to manage birds.We documented factors that influenced tree fruit bird damage from 2012 through 2014 with a coordinated field study in Michigan, New York, and Washington. For sweet cherries, percent bird damage was higher in 2012 compared to 2013 and 2014, in Michigan and New York compared toWashington, and in blocks with more edges adjacent to non-sweet cherry land-cover types. These patterns appeared to be associated with fruit abundance patterns; 2012 was a particularly lowyield year for tree fruits in Michigan and New York and percent bird damage was high. In addition, percent bird damage to sweet and tart cherries in Michigan was higher in landscapes with low to moderate forest cover compared to higher forest cover landscapes. \u27Honeycrisp\u27 apple blocks under utility wires were marginally more likely to have greater bird damage compared to blocks without wires. We recommend growers prepare bird management plans that consider the spatial distribution of fruit and non-fruit areas of the farm. Growers should generally expect to invest more in bird management in low-yield years, in blocks isolated from other blocks of the same crop, and in blocks where trees can provide entry to the crop for frugivorous birds

Spitzer Survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (SAGE) I: Overview and Initial Results

We are performing a uniform and unbiased, ~7x7 degrees imaging survey of the Large Magellanic Cloud (LMC), using the IRAC and MIPS instruments on board the Spitzer Space Telescope in order to survey the agents of a galaxy's evolution (SAGE), the interstellar medium (ISM) and stars in the LMC. The detection of diffuse ISM with column densities >1.2x10^21 H cm^-2 permits detailed studies of dust processes in the ISM. SAGE's point source sensitivity enables a complete census of newly formed stars with masses >3 solar masses that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass loss rates >1x10^-8 solar masses per year will quantify the rate at which evolved stars inject mass into the ISM of the LMC. The observing strategy includes two epochs in 2005, separated by three months, that both mitigate instrumental artifacts and constrain source variability. The SAGE data are non-proprietary. The data processing includes IRAC and MIPS pipelines and a database for mining the point source catalogs, which will be released to the community in support of Spitzer proposal cycles 4 and 5. We present initial results on the epoch 1 data with a special focus on the N79 and N83 region. The SAGE epoch 1 point source catalog has ~4 million sources. The point source counts are highest for the IRAC 3.6 microns band and decrease dramatically towards longer wavelengths consistent with the fact that stars dominate the point source catalogs and that the dusty objects, e.g. young stellar objects and dusty evolved stars that detected at the longer wavelengths, are rare in comparison. We outline a strategy for identifying foreground MW stars, that may comprise as much as 18% of the source list, and background galaxies, that may comprise ~12% of the source list.Comment: Accepted by the Astronomical Journa