1,825 research outputs found
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
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
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
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)
Traps of multi-level governance. Lessons from the implementation of the Water Framework Directive in Italy
During recent decades, different patterns of multi-level governance (MLG) have spread across Europe as a consequence of Europeanisation of public policies, which have increasingly adopted decentralized and participatory procedures conceived as a tool of more effective and accountable policy-making. It appears, however, that the implementation of operational designs based on MLG may be rather problematic and it does not necessarily bring to the expected performance improvements. Referring to the case of the EU Water Framework Directive (2000/60/EC), which conceives the creation of new multi-level institutional settings as a key tool for enacting a new holistic approach to water management and protection, this article explores the difficulties that the implementation of such settings has brought in Italy, despite some favorable pre-conditions existing in the country. Evidence is provided that along with institutional and agency variables, the implementation effectiveness of MLG arrangements promoted by the EU can be challenged by their inherent characteristics
Migration as Adaptation? Exploring The Scope for Co-ordinating Environmental and Migration Policies in the European Union
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