Bounds on effective Majorana neutrino masses at HERA

The lepton-number violating process e p \to nu_e l l' X mediated by Majorana neutrinos is studied for the HERA collider for (l l') = (e tau), (mu tau), (mu mu) and (tau tau). Only the muonic decay of the tau is considered. The direct limit on the effective muon Majorana mass, is improved significantly to 4.0 times 10^3 GeV and for the first time direct limits on the analogous effective masses connected with the tau sector are given, namely 4.2 times 10^3 GeV for , 4.4 times 10^3 GeV for and 2.0 times 10^4 GeV for . We find that a more general analysis for an upgraded HERA could improve this values by a factor of up to 40, yet still being orders of magnitude worse than indirect limits.Comment: 9 pages, 4 figures, revised versio

Experimental neutrino physics

The current experimental status of neutrino physics is reviewed. It contains the evidences for a non-vanishing neutrino rest mass from neutrino oscillation searches. In addition an outlook is given on determining the various mixing matrix elements and mass differences more precisely with new experiments. Of special interest is the value of the mixing angle \theta_{13} determining the possibility of detecting leptonic CP violation in the future. The prospect for absolute mass measurements using beta and double beta decay as well as cosmological observations is presented.Comment: 11 pages, 11 figures, Inv. talk presented at the DPF 2004 meeting of the APS, Riverside, Aug. 200

A Mars orbital laser altimeter for rover trafficability: Instrument concept and science potential

Limited information on the types of geologic hazards (boulders, troughs, craters etc.) that will affect rover trafficability on Mars are available for the two Viking Lander sites, and there are no prospects for increasing this knowledge base in the near future. None of the instrument payloads on the upcoming Mars Observer or Soviet PHOBOS missions can directly measure surface obstacles on the scales of concern for rover safety (a few meters). Candidate instruments for the Soviet Mars 92 orbiter/balloon/rover mission such as balloon-borne stereo imaging, rover panoramic imaging, and orbital synthetic aperature imaging (SAR) are under discussion, but data from this mission may not be available for target areas of interest for the U.S. Mars Rover Sample Return (MRSR) mission. In an effort to determine how to directly measure the topography of surface obstacles that could affect rover trafficability on Mars, we are studying how to design a laser altimeter with extremely high spatial and vertical resolution that would be suitable for a future Mars Orbiter spacecraft (MRSR precursor or MRSR orbiter). This report discusses some of the design issues associated with such an instrument, gives examples of laser altimeter data collected for Mars analog terrains on Earth, and outlines the scientific potential of data that could be obtained with the system

The effects of Venus' thermal structure on buoyant magma ascent

The recent Magellan images have revealed a broad spatial distribution of surface volcanism on Venus. Previous work in modeling the ascent of magma on both Venus and Earth has indicated that the planetary thermal structure significantly influences the magmatic cooling rates and thus the amount of magma that can be transported to the surface before solidification. In order to understand which aspects of the thermal structure have the greatest influence on the cooling of ascending magma, we have constructed magma cooling curves for both plutonic and crack buoyant ascent mechanisms, and evaluated the curves for variations in the planetary mantle temperature, thermal gradient curvature with depth, surface temperature gradient, and surface temperature. The planetary thermal structure is modeled as T/T(sub 0) = 1-tau(1-Z/Z(sub 0)(exp n), where T is the temperature, T(sub 0) is the source depth temperature, tau = 1-(T(sub s)/T(sub 0)) where T(sub s) is the planetary surface temperature, Z is the depth, Z(sub 0) is the source depth, and n is a constant that controls thermal gradient curvature with depth. The equation is used both for mathematical convenience and flexibility, as well as its fit to the thermal gradients predicted by the cooling half-space models. We assume a constant velocity buoyant ascent, body-averaged magma temperatures and properties, an initially crystal-free magma, and the same liquidus and solidus for both Venus and Earth

Validity of the Nebraska Reverter Act

I. Introduction II. Legislative History III. Does the Reverter Act Take Property Unconstitutionally? IV. Does the Reverter Act Repeal Existing Nebraska Law? V. Is the Nebraska Reverter Act Invalid on the Ground That It Impairs the Obligation of Contracts? VI. Is the Nebraska Reverter Act Invalid on the Ground That It Constitutes Special Legislation? VII. Are the Provisions of the Reverter Act Capable of Severance If a Portion of the Act Is Declared Unconstitutional? VIII. Conclusio

Implementation of a Revised Intubation Checklist For a Critical Care Transport Team

Critical care transport teams are often tasked with performing endotracheal intubation (ETI) during transport while adhering “to the same standards as in-hospital emergency anesthesia” (Lockey et al., 2017). One transport team adopted a checklist in 2014 to meet this high standard, but because of changes in equipment and practice expectation, an updated version was needed. The purpose of this quality improvement (QI) project was to design an updated checklist and measure the following primary outcomes: first pass success and steps taken to mitigate hypoxia and hypotension (and/or elevated shock index) prior to intubation. Additionally, a survey was administered to the clinicians after the project to determine their opinion on the usefulness of the checklist toward meeting these objectives. A total of twelve prospective and twelve retrospective charts were reviewed, and data analysis demonstrated: an improvement of first pass success from 75% with the original checklist and 92% with the updated checklist; an increase in taking steps to avoid hypoxia (67% to 75%) and hypotension (58% to 67%). Survey results were mixed and showed most clinicians felt the resource was useful but may have contained too much information to use in this situation. Overall, the revised checklist resulted in clinically significant improvements in achieving the primary objectives of improved first pass success rates and increasing steps to avoid hypoxia and hypotension

A new precision measurement of the {\alpha}-decay half-life of 190Pt

A laboratory measurement of the $\alpha$-decay half-life of $^{190}$Pt has been performed using a low background Frisch grid ionisation chamber. A total amount of 216.60(17) mg of natural platinum has been measured for 75.9 days. The resulting half-life is $(4.97\pm0.16)\times 10^{11}$ years, with a total uncertainty of 3.2%. This number is in good agreement with the half-life obtained using the geological comparison method