5,443 research outputs found
Fatigue testing a plurality of test specimens and method
Described is a fatigue testing apparatus for simultaneously subjecting a plurality of material test specimens to cyclical tension loading to determine the fatigue strength of the material. The fatigue testing apparatus includes a pulling head having cylinders defined therein which carry reciprocating pistons. The reciprocation of the pistons is determined by cyclical supplies of pressurized fluid to the cylinders. Piston rods extend from the pistons through the pulling head and are attachable to one end of the test specimens, the other end of the test specimens being attachable to a fixed base, causing test specimens attached between the piston rods and the base to be subjected to cyclical tension loading. Because all the cylinders share a common pressurized fluid supply, the breaking of a test specimen does not substantially affect the pressure of the fluid supplied to the other cylinders nor the tension applied to the other test specimens
How Should America's Anti-Terrorism Budget Be Allocated? Findings from a National Survey of Attitudes of U.S. Residents about Terrorism
U.S. residents are very concerned about future terrorist attacks and they are willing to commit substantial sums to prevent further terrorist acts. Protecting against another 9/11 style incident is important, but U.S. residents are more concerned about protecting the food supply system and preventing release of chemical or biological agents in public areas. On average respondents would allocate 13.3 percent more to protect the food supply chain and 12.0 percent more to protect against release of a toxic chemical or biological agent than they would to protect against another terrorist attack using hijacked aircraft. Approximately 8.6 billion of fiscal authority for programs protecting against all types of catastrophic terrorist incidents, including protection against radiological or nuclear incidents, as well as protecting the food supply and preventing chemical or biological attacks. No one would argue that decisions on the size and internal allocation of the nation's homeland security budget should be made on the basis of a public opinion survey, but this survey indicates that Americans would likely support additional spending to defend the food system and protect against release of a chemical or biological agent.Political Economy,
Defending America's Food Supply Against Terrorism: Who is Responsible? Who Should Pay?
Food Consumption/Nutrition/Food Safety, Q18, H44, H56,
Neutron diffraction study at 37 K of sodium triaqua(ethylenediaminetetraacetato)samarate(III) pentahydrate, Na[Sm(C10H12N2O8)(H2O)3].5H2O
This is the publisher's version, also available electronically from http://scripts.iucr.org/cgi-bin/paper?S0108270184009173.See article for abstract
Impacts of Coastal Land Use and Shoreline Armoring on Estuarine Ecosystems: an Introduction to a Special Issue
The nearshore land-water interface is an important ecological zone that faces anthropogenic pressure from development in coastal regions throughout the world. Coastal waters and estuaries like Chesapeake Bay receive and process land discharges loaded with anthropogenic nutrients and other pollutants that cause eutrophication, hypoxia, and other damage to shallow-water ecosystems. In addition, shorelines are increasingly armored with bulkhead (seawall), riprap, and other structures to protect human infrastructure against the threats of sea-level rise, storm surge, and erosion. Armoring can further influence estuarine and nearshore marine ecosystem functions by degrading water quality, spreading invasive species, and destroying ecologically valuable habitat. These detrimental effects on ecosystem function have ramifications for ecologically and economically important flora and fauna. This special issue of Estuaries and Coasts explores the interacting effects of coastal land use and shoreline armoring on estuarine and coastal marine ecosystems. The majority of papers focus on the Chesapeake Bay region, USA, where 50 major tributaries and an extensive watershed (similar to 167,000 km(2)), provide an ideal model to examine the impacts of human activities at scales ranging from the local shoreline to the entire watershed. The papers consider the influence of watershed land use and natural versus armored shorelines on ecosystem properties and processes as well as on key natural resources
Attention Maintenance in Novice Drivers: Assessment and Training
All programs assessing attention maintenance inside the vehicle have required eye trackers and either a driving simulator or a specially equipped field vehicle. Ideally, one would like a way to assess attention maintenance that could be implemented on a desktop PC. Additionally, one would like to have a program that could be used to train novice drivers to maintain their attention more safely on the forward roadway. An experiment was run (a) to determine whether a program FOCAL (Focused Concentration and Attention Learning) using a desktop PC could differentiate between the attention maintenance skills of novice and experienced drivers and (b) to determine whether a program that improved the hazard anticipation skills of novice drivers might also improve their attention maintenance skills. FOCAL was able to differentiate between the attention maintenance skills of novice and experienced drivers. However, hazard anticipation training did not improve the attention maintenance skills of the novice drivers
Investigation of pulsed laser induced dewetting in nanoscopic metal films
Hydrodynamic pattern formation (PF) and dewetting resulting from pulsed laser
induced melting of nanoscopic metal films have been used to create spatially
ordered metal nanoparticle arrays with monomodal size distribution on
SiO_{\text{2}}/Si substrates. PF was investigated for film thickness h\leq7 nm
< laser absorption depth \sim11 nm and different sets of laser parameters,
including energy density E and the irradiation time, as measured by the number
of pulses n. PF was only observed to occur for E\geq E_{m}, where E_{m} denotes
the h-dependent threshold energy required to melt the film. Even at such small
length scales, theoretical predictions for E_{m} obtained from a
continuum-level lumped parameter heat transfer model for the film temperature,
coupled with the 1-D transient heat equation for the substrate phase, were
consistent with experimental observations provided that the thickness
dependence of the reflectivity of the metal-substrate bilayer was incorporated
into the analysis. The spacing between the nanoparticles and the particle
diameter were found to increase as h^{2} and h^{5/3} respectively, which is
consistent with the predictions of the thin film hydrodynamic (TFH) dewetting
theory. These results suggest that fast thermal processing can lead to novel
pattern formation, including quenching of a wide range of length scales and
morphologies.Comment: 36 pages, 11 figures, 1 tabl
Experimental study of the role of physicochemical surface processing on the IN ability of mineral dust particles
During the measurement campaign FROST 2 (FReezing Of duST 2), the Leipzig Aerosol Cloud Interaction Simulator (LACIS) was used to investigate the influence of various surface modifications on the ice nucleating ability of Arizona Test Dust (ATD) particles in the immersion freezing mode. The dust particles were exposed to sulfuric acid vapor, to water vapor with and without the addition of ammonia gas, and heat using a thermodenuder operating at 250 °C. Size selected, quasi monodisperse particles with a mobility diameter of 300 nm were fed into LACIS and droplets grew on these particles such that each droplet contained a single particle. Temperature dependent frozen fractions of these droplets were determined in a temperature range between −40 °C ≤T≤−28 °C. The pure ATD particles nucleated ice over a broad temperature range with their freezing behavior being separated into two freezing branches characterized through different slopes in the frozen fraction vs. temperature curves. Coating the ATD particles with sulfuric acid resulted in the particles' IN potential significantly decreasing in the first freezing branch (T>−35 °C) and a slight increase in the second branch (T≤−35 °C). The addition of water vapor after the sulfuric acid coating caused the disappearance of the first freezing branch and a strong reduction of the IN ability in the second freezing branch. The presence of ammonia gas during water vapor exposure had a negligible effect on the particles' IN ability compared to the effect of water vapor. Heating in the thermodenuder led to a decreased IN ability of the sulfuric acid coated particles for both branches but the additional heat did not or only slightly change the IN ability of the pure ATD and the water vapor exposed sulfuric acid coated particles. In other words, the combination of both sulfuric acid and water vapor being present is a main cause for the ice active surface features of the ATD particles being destroyed. A possible explanation could be the chemical transformation of ice active metal silicates to metal sulfates. The strongly enhanced reaction between sulfuric acid and dust in the presence of water vapor and the resulting significant reductions in IN potential are of importance for atmospheric ice cloud formation. Our findings suggest that the IN concentration can decrease by up to one order of magnitude for the conditions investigated
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Inhibition of chemotherapy resistant breast cancer stem cells by a ROR1 specific antibody.
Breast cancers enduring treatment with chemotherapy may be enriched for cancer stem cells or tumor-initiating cells, which have an enhanced capacity for self-renewal, tumor initiation, and/or metastasis. Breast cancer cells that express the type I tyrosine kinaselike orphan receptor ROR1 also may have such features. Here we find that the expression of ROR1 increased in breast cancer cells following treatment with chemotherapy, which also enhanced expression of genes induced by the activation of Rho-GTPases, Hippo-YAP/TAZ, or B lymphoma Mo-MLV insertion region 1 homolog (BMI1). Expression of ROR1 also enhanced the capacity of breast cancer cells to invade Matrigel, form spheroids, engraft in Rag2-/-[Formula: see text] mice, or survive treatment with paclitaxel. Treatment of mice bearing breast cancer patient-derived xenografts (PDXs) with the humanized anti-ROR1 monoclonal antibody cirmtuzumab repressed expression of genes associated with breast cancer stemness, reduced activation of Rho-GTPases, Hippo-YAP/TAZ, or BMI1, and impaired the capacity of breast cancer PDXs to metastasize or reengraft Rag2-/-[Formula: see text] mice. Finally, treatment of PDX-bearing mice with cirmtuzumab and paclitaxel was more effective than treatment with either alone in eradicating breast cancer PDXs. These results indicate that targeting ROR1 may improve the response to chemotherapy of patients with breast cancer
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