Development of Fuses for Protection of Geiger-Mode Avalanche Photodiode Arrays

Current-limiting fuses composed of Ti/Al/Ni were developed for use in Geiger-mode avalanche photodiode arrays for each individual pixel in the array. The fuses were designed to burn out at ∼4.5 × 10[superscript −3] A and maintain post-burnout leakage currents less than 10[superscript −7] A at 70 V sustained for several minutes. Experimental fuse data are presented and successful incorporation of the fuses into a 256 × 64 pixel InP-based Geiger-mode avalanche photodiode array is reported

Reversing factor Xa inhibitors - clinical utility of andexanet alfa

Approximately half of patients started on an oral anticoagulant in the USA now receive one of the newer direct oral anticoagulants (DOACs). Although there is an approved reversal agent for the direct thrombin inhibitor dabigatran, a specific reversal agent for the anti-factor Xa (FXa) DOACs has yet to be licensed. Unlike the strategy to reverse the only oral direct thrombin inhibitor with idarucizumab, which is a humanized monoclonal antibody fragment, a different approach is necessary to design a single agent that can reverse multiple anti-FXa medications. Andexanet alfa is a FXa decoy designed to reverse all anticoagulants that act through this part of the coagulation cascade including anti-FXa DOACs, such as apixaban, edoxaban and rivaroxaban, and indirect FXa inhibitors such as low-molecular-weight heparins. This narrative reviews the development of andexanet alfa and explores its basic science, pharmacokinetics/pharmacodynamics, animal models, and human studies

Constraints on the Geological History of the Karst System in Southern Missouri, U.S.A. Provided by Radiogenic, Cosmogenic and Physical/Chemical Characteristics of Doline Fill

Območje Ozarkov v južnem Missouriju gradijo predvsem karbonatne, morske, platformne kamnine paleozojske starosti. Teren, ki vsebuje obširen kras, predstavlja kopno že od poznega Paleozojka. Da bi bolje razumeli geološko zgodovino tega kraškega sistema, smo raziskali stratigrafske podatke ohranjene v zapolnitvi velike vrtače pri največjem izviru v okolici. Vzorci zapolnitve iz naravnih izdankov in iz vrtine so bili analizirani s termoluminiscenco (TL) in 10Be kozmogeno metodo. Fizikalno-kemijske značilnosti zapolnitve so bile določene vizualno, z rentgensko metodo in merjenjem velikosti delcev. Podatki vrtine kažejo, da je debelina alohtonega materiala, ki zapolnjuje vrtačo 36,3 m. Ta material prekriva podorne bloke in sedimente debeline vsaj 15,6 m. Glede na teksturo, strukturo in barvo delimo material, ki zapolnjuje vrtačo na 7 con. Analize 10Be koncentracij kažejo, da material za celotni stolpec zapolnitve izvira iz rezidualnega materiala iz srednjega (Illinoian) in zgornjega Pleistocena (Wisconsian). Rentgenske analize glin kažejo, da zapolnitev vrtače vsebuje enake količine kaolinita in illita, kar je skladno z zemeljskim preperevanjem.The Ozark Plateaus region of southern Missouri is underlain by dominantly carbonate marine platform rocks of Paleozoic age. The region has been sub-aerially exposed since the late Paleozoic and is characterized by extensive karst. To better understand the geologic history of this regional karst system, we examined the stratigraphic record preserved in the fill of a large doline near the largest spring in the region. Samples of fill from natural exposures and drill core were analyzed using thermoluminescence (TL) and 10Be cosmogenic techniques, and the physical/chemical characteristics of the fill material were determined by visual inspection, X-ray analyses, and grain-size measurements. Drill-hole data indicate that the allochthonous doline fill is 36.3 m thick and rests on at least 15.6 m of cave breakdown and sediment. The doline fill is divisible into 7 zones. Analysis of 10Be concentrations suggest that the entire doline fill was derived from local residuum during the middle (Illinoian) to late Pleistocene (Wisconsinan). X-ray diffraction analyses of clays throughout the doline fill indicate that they consist of nearly equal amounts of kaolinite and illite, consistent with terrestrial weathering.

Interplay of Coulomb blockade and Aharonov-Bohm resonances in a Luttinger liquid

We consider a ring of strongly interacting electrons connected to two external leads by tunnel junctions. By studying the positions of conductance resonances as a function of gate voltage and magnetic flux the interaction parameter $g$ can be determined experimentally. For a finite ring the minimum conductance is strongly influenced by device geometry and electron-electron interactions. In particular, if the tunnel junctions are close to one another the interaction-related orthogonality catastrophe is suppressed and the valley current is unexpectedly large.Comment: 10 page

Interpretation of Photoemission Spectra of (TaSe4)2I as Evidence of Charge Density Wave Fluctuations

The competition between different and unusual effects in quasi-one-dimensional conductors makes the direct interpretation of experimental measurements of these materials both difficult and interesting. We consider evidence for the existence of large charge-density-wave fluctuations in the conducting phase of the Peierls insulator (TaSe4)2I, by comparing the predictions of a simple Lee, Rice and Anderson theory for such a system with recent angle-resolved photoemission spectra. The agreement obtained suggests that many of the unusual features of these spectra may be explained in this way. This view of the system is contrasted with the behaviour expected of a Luttinger liquid.Comment: Archive copy of published paper. 19 pages, 12 figures, uses IOP macro

Temperature, Pressure, and Infrared Image Survey of an Axisymmetric Heated Exhaust Plume

The focus of this research is to numerically predict an infrared image of a jet engine exhaust plume, given field variables such as temperature, pressure, and exhaust plume constituents as a function of spatial position within the plume, and to compare this predicted image directly with measured data. This work is motivated by the need to validate computational fluid dynamic (CFD) codes through infrared imaging. The technique of reducing the three-dimensional field variable domain to a two-dimensional infrared image invokes the use of an inverse Monte Carlo ray trace algorithm and an infrared band model for exhaust gases. This report describes an experiment in which the above-mentioned field variables were carefully measured. Results from this experiment, namely tables of measured temperature and pressure data, as well as measured infrared images, are given. The inverse Monte Carlo ray trace technique is described. Finally, experimentally obtained infrared images are directly compared to infrared images predicted from the measured field variables

A maximum rupture model for the central and southern Cascadia subduction zone—reassessing ages for coastal evidence of megathrust earthquakes and tsunamis

A new history of great earthquakes (and their tsunamis) for the central and southern Cascadia subduction zone shows more frequent (17 in the past 6700 yr) megathrust ruptures than previous coastal chronologies. The history is based on along-strike correlations of Bayesian age models derived from evaluation of 554 radiocarbon ages that date earthquake evidence at 14 coastal sites. We reconstruct a history that accounts for all dated stratigraphic evidence with the fewest possible ruptures by evaluating the sequence of age models for earthquake or tsunami contacts at each site, comparing the degree of temporal overlap of correlated site age models, considering evidence for closely spaced earthquakes at four sites, and hypothesizing only maximum-length megathrust ruptures. For the past 6700 yr, recurrence for all earthquakes is 370–420 yr. But correlations suggest that ruptures at ∼1.5 ka and ∼1.1 ka were of limited extent (<400 km). If so, post-3-ka recurrence for ruptures extending throughout central and southern Cascadia is 510–540 yr. But the range in the times between earthquakes is large: two instances may be ∼50 yr, whereas the longest are ∼550 and ∼850 yr. The closely spaced ruptures about 1.6 ka may illustrate a pattern common at subduction zones of a long gap ending with a great earthquake rupturing much of the subduction zone, shortly followed by a rupture of more limited extent. The ruptures of limited extent support the continued inclusion of magnitude-8 earthquakes, with longer ruptures near magnitude 9, in assessments of seismic hazard in the region

The La Prele Mammoth Site, Converse County, Wyoming, USA

The La Prele Mammoth site is a Clovis archaeolog- ical site in Converse County, Wyoming (U.S.A.) that preserves chipped stone artifacts in spatial as- sociation with the remains of a subadult Columbi- an mammoth (Mammuthus columbi). The site was discovered in 1986 and initially tested by George Frison in 1987, but work ceased there until 2014 due to a disagreement with the landowner. In the intervening years, questions arose as to whether the artifacts and mammoth remains were truly associated, and the site was largely dismissed by American archaeologists. Recent excavations have not only demonstrated that La Prele was the loca- tion of a mammoth kill by Clovis hunters around 12,850 years ago, but it also preserves a campsite in close proximity to the kill. The camp includes multiple hearth-centered activity areas that appear to represent domestic spaces, reflected by the pres- ence of a diversity of stone tool forms, bone nee- dles, a bone bead, a large area of hematite-stained matrix, and the butchered and cooked remains of at least one other large mammal species. The site has the potential to inform us about aspects of the social organization of Clovis bands, particularly with respect to mammoth hunting and butchery.The symposium and the volume "Human-elephant interactions: from past to present" were funded by the Volkswagen Foundation

Edge-Magnetoplasmon Wave-Packet Revivals in the Quantum Hall Effect

The quantum Hall effect is necessarily accompanied by low-energy excitations localized at the edge of a two-dimensional electron system. For the case of electrons interacting via the long-range Coulomb interaction, these excitations are edge magnetoplasmons. We address the time evolution of localized edge-magnetoplasmon wave packets. On short times the wave packets move along the edge with classical E cross B drift. We show that on longer times the wave packets can have properties similar to those of the Rydberg wave packets that are produced in atoms using short-pulsed lasers. In particular, we show that edge-magnetoplasmon wave packets can exhibit periodic revivals in which a dispersed wave packet reassembles into a localized one. We propose the study of edge-magnetoplasmon wave packets as a tool to investigate dynamical properties of integer and fractional quantum-Hall edges. Various scenarios are discussed for preparing the initial wave packet and for detecting it at a later time. We comment on the importance of magnetoplasmon-phonon coupling and on quantum and thermal fluctuations.Comment: 18 pages, RevTex, 7 figures and 2 tables included, Fig. 5 was originally 3Mbyte and had to be bitmapped for submission to archive; in the process it acquired distracting artifacts, to upload the better version, see http://physics.indiana.edu/~uli/publ/projects.htm