Performance of Recycled Asphalt Shingles in Hot Mix Asphalt

State highway agencies are increasingly intersted in using recycled asphalt shingles (RAS) in hot mix asphalt (HMA) applications, yet many agencies share common questions about the effect of RAS on the performance of HMA. Previous research has allowed for only limited laboratory testing and field surveys. The complexity of RAS materials and lack of past experiences led to the creation of Transportation Pooled Fund (TPF) Program TPF-5(213). The primary goal of this study is to address research needs of state DOT and environmental officials to determine the best practices for the use of recycled asphalt shingles in hot-mix asphalt applications. Agencies participating in the study include Missouri (lead state), California, Colorado, Illinois, Indiana, Iowa, Minnesota, Wisconsin, and the Federal Highway Administration. The agencies conducted demonstration projects that focused on evaluating different aspects (factors) of RAS that include RAS grind size, RAS percentage, RAS source (post-consumer versus post-manufactured), RAS in combination with warm mix asphalt technology, RAS as a fiber replacement for stone matrix asphalt, and RAS in combination with ground tire rubber. Field mixes from each demonstration project were sampled for conducting the following tests: dynamic modulus, flow number, four-point beam fatigue, semi-circular bending, and binder extraction and recovery with subsequent binder characterization. Pavement condition surveys were then conducted for each project after completion. The demonstration projects showed that pavements using RAS alone or in combination with other cost saving technologies (e.g., WMA, RAP, GTR, SMA) can be successfully produced and meet state agency quality assurance requirements. The RAS mixes have very promising prospects since laboratory test results indicate good rutting and fatigue cracking resistance with low temperature cracking resistance similar to the mixes without RAS. The pavement condition of the mixes in the field after two years corroborated the laboratory test results. No signs of rutting, wheel path fatigue cracking, or thermal cracking were exhibited in the pavements. However, transverse reflective cracking from the underlying jointed concrete pavement was measured in the Missouri, Colorado, Iowa, Indiana, and Minnesota projects

Sjøoverlevelse til smolt eksponert for aluminium i brakkvann -oppvandring av laks i Storelva i 2012

Fra oppdrett er det kjent at aluminium (Al) i brakkvann kan drepe laks. Det var mer usikkert om utvandrende vill laksesmolt ville påvirkes og om Al i brakkvann dermed kunne ha effekt på sjøoverlevelse. Forsøk utført i perioden 2003 til 2010 påviste at Al på reaktiv form mobiliseres og akkumuleres på laksesmoltens gjeller når saltnivået er innenfor intervallet >1 til <10 psu. Telemetriundersøkelser har vist at smoltutvandring hemmes i brakkvann, uten at man fra de dataene kunne konkludere med bestandseffekter. I 2009 og 2010 ble utvandrende laksesmolt merket med passive integrerte transpondere (PIT-merker). Disse merkene vil påvises automatisk når fisken tilbakevandrer til vassdraget. Resultater basert på gjenfangster av voksen laks tyder på at Al i brakkvann kan halvere sjøoverlevelse. Bestandseffektene avhenger av Al-konsentrasjon samt hvordan konsentrasjonen endres over tid om våren. Mens smolt som ankom fjorden i mai 2009 opplevde ugunstige forhold utover hele juni, økte saliniteten i overgangen mai/juni i 2010 til nivåer som ikke påvirket fisken. Til tross for at denne smolten opplevde Al i brakkvann i mai, ble fisken ikke påvirket i juni. Samlet tyder resultatene på at Al i brakkvann kan påvirke antall som overlever fra smolt til laks, men at effekten vil variere mellom år, og hvor variasjon i respons kan knyttes til de hydrologiske forholdene.Direktoratet for naturforvaltnin

Sjøoverlevelse til smolt eksponert for aluminium i brakkvann -oppvandring av laks i Storelva i 2012

Fra oppdrett er det kjent at aluminium (Al) i brakkvann kan drepe laks. Det var mer usikkert om utvandrende vill laksesmolt ville påvirkes og om Al i brakkvann dermed kunne ha effekt på sjøoverlevelse. Forsøk utført i perioden 2003 til 2010 påviste at Al på reaktiv form mobiliseres og akkumuleres på laksesmoltens gjeller når saltnivået er innenfor intervallet >1 til <10 psu. Telemetriundersøkelser har vist at smoltutvandring hemmes i brakkvann, uten at man fra de dataene kunne konkludere med bestandseffekter. I 2009 og 2010 ble utvandrende laksesmolt merket med passive integrerte transpondere (PIT-merker). Disse merkene vil påvises automatisk når fisken tilbakevandrer til vassdraget. Resultater basert på gjenfangster av voksen laks tyder på at Al i brakkvann kan halvere sjøoverlevelse. Bestandseffektene avhenger av Al-konsentrasjon samt hvordan konsentrasjonen endres over tid om våren. Mens smolt som ankom fjorden i mai 2009 opplevde ugunstige forhold utover hele juni, økte saliniteten i overgangen mai/juni i 2010 til nivåer som ikke påvirket fisken. Til tross for at denne smolten opplevde Al i brakkvann i mai, ble fisken ikke påvirket i juni. Samlet tyder resultatene på at Al i brakkvann kan påvirke antall som overlever fra smolt til laks, men at effekten vil variere mellom år, og hvor variasjon i respons kan knyttes til de hydrologiske forholdene.Direktoratet for naturforvaltnin

The Basics of Contract Grazing

Contract grazing arrangements put livestock on pastures in managed grazing systems. This fact sheet, #1 in a four-part series, describes the basics of contract grazing

Mechanical design of the optical modules intended for IceCube-Gen2

IceCube-Gen2 is an expansion of the IceCube neutrino observatory at the South Pole that aims to increase the sensitivity to high-energy neutrinos by an order of magnitude. To this end, about 10,000 new optical modules will be installed, instrumenting a fiducial volume of about 8 km3. Two newly developed optical module types increase IceCube’s current sensitivity per module by a factor of three by integrating 16 and 18 newly developed four-inch PMTs in specially designed 12.5-inch diameter pressure vessels. Both designs use conical silicone gel pads to optically couple the PMTs to the pressure vessel to increase photon collection efficiency. The outside portion of gel pads are pre-cast onto each PMT prior to integration, while the interiors are filled and cast after the PMT assemblies are installed in the pressure vessel via a pushing mechanism. This paper presents both the mechanical design, as well as the performance of prototype modules at high pressure (70 MPa) and low temperature (−40∘C), characteristic of the environment inside the South Pole ice

The next generation neutrino telescope: IceCube-Gen2

The IceCube Neutrino Observatory, a cubic-kilometer-scale neutrino detector at the geographic South Pole, has reached a number of milestones in the field of neutrino astrophysics: the discovery of a high-energy astrophysical neutrino flux, the temporal and directional correlation of neutrinos with a flaring blazar, and a steady emission of neutrinos from the direction of an active galaxy of a Seyfert II type and the Milky Way. The next generation neutrino telescope, IceCube-Gen2, currently under development, will consist of three essential components: an array of about 10,000 optical sensors, embedded within approximately 8 cubic kilometers of ice, for detecting neutrinos with energies of TeV and above, with a sensitivity five times greater than that of IceCube; a surface array with scintillation panels and radio antennas targeting air showers; and buried radio antennas distributed over an area of more than 400 square kilometers to significantly enhance the sensitivity of detecting neutrino sources beyond EeV. This contribution describes the design and status of IceCube-Gen2 and discusses the expected sensitivity from the simulations of the optical, surface, and radio components

Sensitivity of IceCube-Gen2 to measure flavor composition of Astrophysical neutrinos

The observation of an astrophysical neutrino flux in IceCube and its detection capability to separate between the different neutrino flavors has led IceCube to constraint the flavor content of this flux. IceCube-Gen2 is the planned extension of the current IceCube detector, which will be about 8 times larger than the current instrumented volume. In this work, we study the sensitivity of IceCube-Gen2 to the astrophysical neutrino flavor composition and investigate its tau neutrino identification capabilities. We apply the IceCube analysis on a simulated IceCube-Gen2 dataset that mimics the High Energy Starting Event (HESE) classification. Reconstructions are performed using sensors that have 3 times higher quantum efficiency and isotropic angular acceptance compared to the current IceCube optical modules. We present the projected sensitivity for 10 years of data on constraining the flavor ratio of the astrophysical neutrino flux at Earth by IceCube-Gen2

Direction reconstruction performance for IceCube-Gen2 Radio

The IceCube-Gen2 facility will extend the energy range of IceCube to ultra-high energies. The key component to detect neutrinos with energies above 10 PeV is a large array of in-ice radio detectors. In previous work, direction reconstruction algorithms using the forward-folding technique have been developed for both shallow (≲20 m) and deep in-ice detectors, and have also been successfully used to reconstruct cosmic rays with ARIANNA. Here, we focus on the reconstruction algorithm for the deep in-ice detector, which was recently introduced in the context of the Radio Neutrino Observatory in Greenland (RNO-G)

Deep Learning Based Event Reconstruction for the IceCube-Gen2 Radio Detector

The planned in-ice radio array of IceCube-Gen2 at the South Pole will provide unprecedented sensitivity to ultra-high-energy (UHE) neutrinos in the EeV range. The ability of the detector to measure the neutrino’s energy and direction is of crucial importance. This contribution presents an end-to-end reconstruction of both of these quantities for both detector components of the hybrid radio array (\u27shallow\u27 and \u27deep\u27) using deep neural networks (DNNs). We are able to predict the neutrino\u27s direction and energy precisely for all event topologies, including the electron neutrino charged-current (νe-CC) interactions, which are more complex due to the LPM effect. This highlights the advantages of DNNs for modeling the complex correlations in radio detector data, thereby enabling a measurement of the neutrino energy and direction. We discuss how we can use normalizing flows to predict the PDF for each individual event which allows modeling the complex non-Gaussian uncertainty contours of the reconstructed neutrino direction. Finally, we discuss how this work can be used to further optimize the detector layout to improve its reconstruction performance

Estimating the coincidence rate between the optical and radio array of IceCube-Gen2

The IceCube-Gen2 Neutrino Observatory is proposed to extend the all-flavour energy range of IceCube beyond PeV energies. It will comprise two key components: I) An enlarged 8km3 in-ice optical Cherenkov array to measure the continuation of the IceCube astrophysical neutrino flux and improve IceCube\u27s point source sensitivity above ∼100TeV; and II) A very large in-ice radio array with a surface area of about 500km2. Radio waves propagate through ice with a kilometer-long attenuation length, hence a sparse radio array allows us to instrument a huge volume of ice to achieve a sufficient sensitivity to detect neutrinos with energies above tens of PeV. The different signal topologies for neutrino-induced events measured by the optical and in-ice radio detector - the radio detector is mostly sensitive to the cascades produced in the neutrino interaction, while the optical detector can detect long-ranging muon and tau leptons with high accuracy - yield highly complementary information. When detected in coincidence, these signals will allow us to reconstruct the neutrino energy and arrival direction with high fidelity. Furthermore, if events are detected in coincidence with a sufficient rate, they resemble the unique opportunity to study systematic uncertainties and to cross-calibrate both detector components