Site comparison for optical visibility statistics in southern Arizona

One of the best locations in the continental United States for astronomical telescopes is southern Arizona. The mountains surrounding Tucson have clear skies 80 percent of the year, with image quality generally better than 2 seconds on peaks. Two of the existing observatory sites in this area are being considered as locations for one of the three Atmospheric Visibility Monitoring (AVM) observatories. These sites are Mount Lemmon and Mount Hopkins. A comparison of the characteristics of each of the sites is made here to identify the more desirable of the two locations. It is recommended that Mount Lemmon be selected as the Arizona site for this project

Low strain, long life creep fatigue of AF2-1DA and INCO 718

Two aircraft turbine disk alloys, GATORIZED AF2-DA and INCO 718 were evaluated for their low strain long life creep-fatigue behavior. Static (tensile and creep rupture) and cyclic properties of both alloys were characterized. The cntrolled strain LCF tests were conducted at 760 C (1400 F) and 649 C (1200 F) for AF2-1DA and INCO 718, respectively. Hold times were varied for tensile, compressive and tensile/compressive strain dwell (relaxation) tests. Stress (creep) hold behavior of AF2-1DA was also evaluated. Generally, INCO 718 exhibited more pronounced reduction in cyclic life due to hold than AF2-1DA. The percent reduction in life for both alloys for strain dwell tests was greater at low strain ranges (longer life regime). Changing hold time from 0 to 0.5, 2.0 and 15.0 min. resulted in corresponding reductions in life. The continuous cycle and cyclic/dwell initiation failure mechanism was predominantly transgranular for AF2-1DA and intergranular for INCO 718

Review of Documenting Rebellions: A Study of Four Lesbian and Gay Archives in Queer Times

The comparative case study, Documenting Rebellions: A Study of Four Lesbian and Gay Archives in Queer Times, traces the development of four prominent lesbian and gay archives as they grew out of the rights movement of the 1960s through the AIDS crisis and into the 21st century. The study is informed by both queer theory and archival theory. The volume historically contextualizes them within the lesbian and gay rights movement, as well as the movement in archival science and practice to restore the voices of those silenced by power structures within society

Trade-offs in Male Lek Behavior

In lek mating systems, males aggregate together and perform courtship displays to visiting females. However, display may be energetically expensive and reduce the time available for foraging. These costs in turn could lower energy reserves, which could decrease survival. I examined trade-offs in male lek behavior using two methods: 1) I conducted an empirical study of how sharp-tailed grouse (Tympanuchus phasianellus) males allocate time between courtship display (“dancing”), agonism, foraging, and inactivity in relation to female numbers both within and across days. I also measured head turning rates during these same behaviors as a proxy for visual attentiveness to the surroundings. 2) I created a stochastic-dynamic programming (SDP) model to investigate how the trade-off between reproductive success and survival (mediated by body condition) affects male reproductive strategies. In my empirical study, I found that the proportion of males engaged in display increased significantly with female numbers whereas foraging decreased significantly with female numbers both within and across days. This indicates that males increase display at the expense of reduced foraging time at periods of high female attendance. In addition, during display, males turned their head only half as frequently as during other activities, which suggests reduced visual attentiveness during display and the potential for increased predation risk. In the SDP model, initial body condition largely determines the optimal seasonal breeding strategy. Males with initially lower body condition are predicted to forage early in the season, maintain lower condition throughout the season, and delay the onset of maximum display effort compared to males with initially higher condition. The results of the two studies suggest that male lek behavior is constrained by both the costs of display and the survival cost of maintaining body condition. Adviser: Robert M. Gibso

Furniture Stability: A Review of Data and Testing Results

This report by Kids In Danger (KID) and Shane's Foundation focuses on tip-overs of dressers and chests. ASTM International, which has developed thousands of voluntary industry consensus technical standards, has a standard in place to test furniture stability. However, furniture on the market is not required to conform, resulting in widespread non-compliance. Additionally, these standards are too lenient and require reform, as testing protocols have remained virtually unchanged for over a decade, despite continuing injuries and deaths. Units may pass the standard, but still present a significant risk. KID advocates for a two-pronged approach to decreasing tip-over incidents:Increasing consumer awareness of the danger of furniture tip-overs and knowledge of the actions needed to keep children safe, andImproving furniture stability by strengthening standards, making those standards mandatory and enforceable and promoting changes in furniture design.KID compiled data from incidents reported to the U.S. Consumer Product Safety Commission (CPSC) by various sources and from the National Electronic Injury Surveillance System (NEISS). These include reports from January 1, 2010 to October 14, 2015. Findings of the data analysis include:Two-year-olds are the age group most affected by tip-overs, especially in regard to fatal incidents.Children age 2 to 5 accounted for 77% of total incidents.The age range of children injured is wider than the age range of children killed by tip-overs.Fatalities accounted for 12% of total incidents.Head injuries (37%) were the most common category of injury.Almost all (98.7%) of head injuries are related to a television tipping over on a child.KID conducted performance tests on a sample of 19 dressers and chests. Testing was run at the UL Furniture Center of Excellence in Holland, Michigan. UL laboratory technicians followed a testing protocol developed by KID. The protocol included tests based on the current voluntary standard for furniture stability. KID added tests that, among other things, evaluated for tip-overs when more weight was added (simulating larger children), drawers were full of clothes, furniture was placed on carpeting as opposed to bare flooring, televisions were placed on top of the furniture, and additional drawers were opened simultaneous with weighting one drawer. These additional tests were intended to be more representative of real-world scenarios.Test results include:Only nine of the 19 units passed performance tests based on the current tip-over safety standard, ASTM F2057.Only two units passed all tests, including the additional testing protocols added by KID.The weight of a television or any type placed on top of the unit did not decrease the stability of furniture.Furniture placed on carpet is less stable than furniture placed on hard floors.Many units remained stable when more than 70 pounds was placed on an open drawer, while others tipped with less than half that weight

Approximate method for predicting the permanent set in a beam in vacuo and in water subject to a shock wave

An approximate method to compute the maximum deformation and permanent set of a beam subjected to shock wave laoding in vacuo and in water was investigated. The method equates the maximum kinetic energy of the beam (and water) to the elastic plastic work done by a static uniform load applied to a beam. Results for the water case indicate that the plastic deformation is controlled by the kinetic energy of the water. The simplified approach can result in significant savings in computer time or it can expediently be used as a check of results from a more rigorous approach. The accuracy of the method is demonstrated by various examples of beams with simple support and clamped support boundary conditions

An ERP study of anaphor resolution with focused and non-focused antecedents

The goal of this study is to better understand when (and why) the combination of semantic overlap between antecedent and anaphor and antecedent focus leads to difficulty in anaphor processing. To investigate these questions, three ERP experiments manipulating semantic overlap and focus compared the ERPs from the onset of the anaphor as well as from the onset of the last word in the sentence containing the anaphor. Our results suggest that although the focus status of an antecedent and the semantic overlap between the antecedent and anaphor are important, these factors are not the only significant contributors to online anaphor resolution. Factors such as readers‘ expectations about thematic shifts also influence the processing. We consider our results in relation to two accounts of anaphor resolution, the Informational Load Hypothesis (Almor, 1999; Almor & Eimas, 2008) and JANUS (Garnham & Cowles, 2008)

Evaluation of the cyclic behavior of aircraft turbine disk alloys, part 2

Several nickel-base aircraft turbine disk superalloys were evaluated at 650 C for resistance to fatigue crack initiation and propagation under cyclic and cyclic/dwell conditions. Controlled strain low cycle fatigue (LCF) and controlled load crack propagation tests were performed and results utilized to provide a direct comparison among the alloys. Tests were performed on selected alloys to evaluate the effects of hold times, mean stresses, stress-dwell cycle types, inert environment, and contractor test methods. At the lower total strain ranges of interest, the alloys exhibited generally increasing initiation life with increasing tensile strength for both cyclic (0.33 Hz) and cyclic/dwell (900-sec hold per cycle) conditions. Rank order of the alloys by LCF initiation life changed substantially at higher strain ranges, approaching the rank order expected from monotonic tensile ductilities. The effect of the 900 sec (15 min) hold time fatigue life varied significantly from alloy to alloy. Generally, the higher-strength, finer-grained alloys exhibited more significant reductions in fatigue life due to the dwell. The effects of mean strain were found to be negligible and the effects of mean stress were pronounced. At high strain ranges the mean stress was near zero and did not contribute to reduction in life. At low strain ranges, however, mean stresses were large and significant reductions in LCF lives occurred

A thin layer of phytoplankton observed in the Philippine Sea with a synthetic moored array of autonomous gliders

Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): C10020, doi:10.1029/2009JC005317.A synthetic moored array composed of five buoyancy-propelled autonomous underwater gliders was used to characterize mesoscale variability and phytoplankton distribution in a 100 km × 100 km domain in the Philippine Sea east of Luzon Strait for 10 days in May 2004. The study area, located east of the Kuroshio near the subtropical front, is dominated by strong internal tides, by energetic westward-propagating mesoscale eddies with azimuthal velocities exceeding 50 cm/s, and by a deep (130 m) maximum in chlorophyll fluorescence. Each glider in the array was instructed to maintain geographic position while repeatedly profiling to 200-m depth. Good station-keeping performance enabled the resulting series of vertical profiles to be interpreted in the same manner as a physically moored chain of instruments. Although organized primarily as a demonstration of glider capabilities, this field exercise provides a unique data set for examining biological-physical interactions in the open ocean. Here we report on the evolution of a thin layer of phytoplankton observed near the deep chlorophyll maximum. Coincident observations of fine structure in temperature and salinity suggest that the thinning process of this layer was driven primarily by physical forcing, most probably vertical shear associated with energetic diurnal internal waves, as opposed to a biological mechanism, such as convergent swimming, grazing, or spatial variation in growth rate.The Office of Naval Research provided support for fieldwork and analysis through grants N-00014-00-1-0256 and N-00014-05-1-0367