The role of the deep space network's frequency and timing system in the detection of gravitational waves

A review of the Deep Space Network's (DSN) use of precision Doppler-tracking of deep space vehicles is presented. The review emphasizes operational and configurational aspects and considers: the projected configuration of the DSN's frequency and timing system; the environment within the DSN provided by the precision atomic standards within the frequency and timing system--both current and projected; and the general requirements placed on the DSN and the frequency and timing system for both the baseline and the nominal gravitational wave experiments. A comment is made concerning the current probability that such an experiment will be carried out in the foreseeable future

Paragenetic Evolution of the Robertson Deposit: Eocene Intrusion Related Gold Deposit in the Northern Shoshone Range, Nevada

The Robertson deposit, formerly known as Tenabo, is an Eocene intrusion-related gold deposit 5 km north of Pipeline, which is a 20 Moz+ Carlin-type gold deposit in the northern Shoshone Range, Nevada. Carlin-type gold deposits have been the focus of many studies as they represent the second largest accumulation of gold in the world, and a growing body of scientific literature indicates that the source for this gold may be related to Eocene magmatism. The presence of an Eocene intrusion-related gold deposit within 5 km of a Carlin-type deposit begs the question of whether the two deposits are genetically related, however detailed characterized of Robertson deposit is needed before this link can be examined. Most of the previously defined gold mineralization at Robertson occurred near the contacts of intrusions and hosted by hornfels in the overlying lithologies. Ongoing exploration has discovered significant free visible gold both within the stock and in distal settings within metasedimentary host rocks. Here, gold mineralization is spatially and temporally related to an intrusive complex referred to as the Tenabo stock, and based on petrographic and geochemical analysis, is composed of successive intrusive phases including an early ilmenite-bearing diorite, andesite dikes, hypabyssal dacitic porphyry dikes, composite ilmenite-bearing granodiorite, granitic porphyry dikes (formerly called feldspar porphyry dikes), pebble dikes, and subvolcanic rhyolitic dikes. The purpose of this study is to characterize gold mineralization as it relates to intrusive phases, alteration styles, and structural controls by combining fieldwork, petrography, geochemistry and geochronology. This study is the first in depth examination of Robertson focusing on gold mineralization within intrusive phases and in distal settings, presenting six new U/Pb LA-ICP-MS ages of intrusive phases, one molybdenite Re/Os age, and one hydrothermal orthoclase 40Ar/39Ar age, conservatively constraining gold mineralization to 39.65-35.77 Ma. Emplacement of the Tenabo stock resulted in contact metamorphism of the host siliciclastic lithologies yielding quartz, biotite, and calc-silicate hornfels, which formed an aureole up to 1 km from the stock. Subsequent hydrothermal alteration followed, including endo/exoskarn, potassic alteration, sericitic alteration, and chloritic alteration. Petrographic observations of veins at Robertson indicate the succession of three main stages referred as 1) pre-gold, 2) syn-gold, and 3) post-gold. The pre-gold stage includes barren quartz veins, potassic alteration veins comprised of biotite veinlets and quartz-K-feldspar, quartz – arsenopyrite, quartz – chalcopyrite, and quartz – molybdenite veins. The syn-gold stage is composed of quartz – gold ± Bi-Te-Se-Pb-Ag-S sulfosalt veins, consisting of native gold seen as single grains in quartz gangue and/or on the surface of pyrrhotite, arsenopyrite, chalcopyrite, and loellingite grains. The post-gold veins encompass pyrite ± quartz, quartz – calcite – polymetallic sulfide veins with Pb-Zn-Sb-Ag-Sn base metal sulfides, bull quartz veins, and calcite veins. Cross-cutting relationships along with geochronological data indicate that gold mineralization resulted from the emplacement of upper Eocene (40.99-37.38 Ma) reduced ilmenite-bearing intrusive phases that intruded into Ordovician-Devonian siliciclastic sedimentary lithologies, forming a high-tonnage, low-grade gold deposit characterized by a Au-As-Bi-Te-Cu metal association, similar to reduced intrusion related gold deposits and gold skarns described globally. Based on petrographic and geochemical evidence, it is concluded that mineralizing conditions for gold precipitation were under relatively low sulfur fugacity and oxidation state, leading to preferential formation of minerals such as native Bi, arsenopyrite, pyrrhotite, and loellingite, typical of low-sulfidation assemblages. Under such conditions it is possible to transport gold to lower temperatures <300°C, where native gold is commonly associated with Bi-bearing minerals or to even lower temperatures (~150-200°C) where it remains within the lattice of sulfides as invisible gold, typifying Carlin-type deposits

Preliminary survey of 21st century civil mission applications of space nuclear power

The purpose was to collect and categorize a forecast of civilian space missions and their power requirements, and to assess the suitability of an SP-100 class space reactor power system to those missions. A wide variety of missions were selected for examination. The applicability of an SP-100 type of nuclear power system was assessed for each of the selected missions; a strawman nuclear power system configuration was drawn up for each mission. The main conclusions are as follows: (1) Space nuclear power in the 50 kW sub e plus range can enhance or enable a wide variety of ambitious civil space mission; (2) Safety issues require additional analyses for some applications; (3) Safe space nuclear reactor disposal is an issue for some applications; (4) The current baseline SP-100 conical radiator configuration is not applicable in all cases; (5) Several applications will require shielding greater than that provided by the baseline shadow-shield; and (6) Long duration, continuous operation, high reliability missions may exceed the currently designed SP-100 lifetime capabilities

Stakeholders\u27 Perceptions on Mandated Student Retention in Early Childhood

Reading is one of the primary goals of the early elementary grades. When students start to struggle with this complex skill, educators and parents search for solutions to rectify quickly mounting gaps before a child falls too far behind. In the State of Oklahoma, lawmakers have passed a law requiring mandatory 3rd grade retention for students who do not pass the state reading test. The purpose of this qualitative case study was to examine the perceptions of stakeholders who had experienced implementation of mandated student retention in early childhood. The study is informed by Bourdieu\u27s cultural capital theory of social distinctions, Bloom\u27s taxonomy theory, and Festinger\u27s social comparison theory. Seventeen participants, including 2 parents, 8 teachers, and 7 administrators, took part in face-to-face interviews and focus groups to provide data on 3rd graders in 4 schools in an Oklahoma district. Responses from interviews and focus groups were audiorecorded, transcribed, and coded for themes. Nine themes emerged from data analysis. These themes reflected participants\u27 concern for the potential damage to students\u27 self-esteem, an increase in dropout rates, and that the 3rd grade is too late for retention. On the positive side, participants indicated mandatory retention permitted retention that had been previously refused, and provides time for maturity, as well as the opportunity for success for struggling students. However, study participants also opined that mandatory retention created new challenges for students, teachers, and schools. Findings guided the development of a policy recommendation to create social change within the participating district, empowering educators to help parents better understand this law and prepare their children for the 3rd grade assessment by outlining a plan for early identification and creating programs for struggling students

Pathfinder: Surface exploration, in-space operations and space transfer

Viewgraphs on the Pathfinder program are presented. Information is given on technology needs, a planetary rover, program management, an autonomous lander, mission applications, orbital assembly, cryogenics, space nuclear reactors, space manufacturing, optical communications, spacecraft propulsion, aerobraking, and orbital transfer vehicles

A comparison of two weight training programs for strength development and the effects of spring football practice on strength retention

The purposes of this study were (1) to determine the possible effects of spring football practice on strength retention among the varsity football players at the University of the Pacific as measured by the four strength tests from Edwin A. Fleishman’s Basic Fitness Test Battery for Evaluation of Physical Fitness Factors; the one repetition maximum scores from five weight training exercises; and the maximum number of bar dips performed for one set: (2) to determine whether weight training during spring football practice is beneficial for strength retention for the duration of spring football practice: and (3) to determine the effectiveness of two weight training programs in the development of strength

Reusable module for the storage, transportation, and supply of multiple propellants in a space environment

A space module has an outer structure designed for traveling in space, a docking mechanism for facilitating a docking operation therewith in space, a first storage system storing a first propellant that burns as a result of a chemical reaction therein, a second storage system storing a second propellant that burns as a result of electrical energy being added thereto, and a bi-directional transfer interface coupled to each of the first and second storage systems to transfer the first and second propellants into and out thereof. The space module can be part of a propellant supply architecture that includes at least two of the space modules placed in an orbit in space

Reusable Hybrid Propellant Modules for Outer-Space Transport

A report summarizes the concept of reusable hybrid propellant modules (HPMs), which would be used in outer space for long-term cryogenic storage of liquefied spacecraft-propellant gases, including for example, oxygen and hydrogen for combustion-based chemical rocket engines and xenon for electric thrusters. The HPM concept would provide the fundamental building block for an efficient, reusable in-space transportation system for both crewed and uncrewed missions. Each HPM would be equipped to implement an advanced zero-boil-off method of managing cryogenic fluids, and would include a fluid-transfer interface comprising standardized fittings that would be compatible with fittings on all supply facilities and on spacecraft to be supplied. The HPM, combined with a chemical or electric orbital transfer spacecraft, would provide an integrated propulsion system. HPMs would supply chemical propellant for time-critical transfers such as crewed missions, and utilize the more efficient electric-propulsion transfer vehicles to transport filled HPMs to the destinations and to return empty HPMs back to near-Earth orbits or other intermediate locations for replenishment and reuse. The HPM prepositioned using electric propulsion would provide the chemical propellant for the crew s return trip in a much more efficient manner than a chemical-only approach. The propellants to fill the HPMs would be delivered from the Earth or other initial supply locations to the intermediate locations by use of automated, compatible spacecraft designed specifically for that purpose. Additionally, multiple HPMs could be aggregated and positioned in orbits and on planets, moons, and asteroids to supply fluids to orbiting and interplanetary spacecraft

INSANE ASYLUMS IN BRITAIN DURING THE NINETEENTH CENTURY

This thesis analyzes insane asylums, in Britain, during the nineteenth century and argues that government, society, and gender had a profound impact on insane asylums and determined the quality of care that female and male patients received as a consequence