Preliminary analysis of an integrated logistics system for OSSA payloads

The results of studies of the Office of Space Science and Applications' (OSSA) need for an integrated logistics system to support OSSA payloads, whether attached to the Space Station or free-flying are detailed. An executive summary, the integrated logistics support strategy, preparation of planning documents and a supportability analysis of the 1.8 meter centrifuge are discussed

Do elections accelerate the COVID-19 pandemic?: Evidence from a natural experiment

Elections define representative democracies but also produce spikes in physical mobility if voters need to travel to polling places. In this paper, we examine whether large-scale, in-person elections propagate the spread of COVID-19. We exploit a natural experiment from the Czech Republic, which biannually renews mandates in one-third of Senate constituencies that rotate according to the 1995 election law. We show that in the second and third weeks after the 2020 elections (held on October 9–10), new COVID-19 infections grew significantly faster in voting compared to non-voting constituencies. A temporarily related peak in hospital admissions and essentially no changes in test positivity rates suggest that the acceleration was not merely due to increased testing. The acceleration did not occur in the population above 65, consistently with strategic risk-avoidance by older voters. Our results have implications for postal voting reforms or postponing of large-scale, in-person (electoral) events during viral outbreaks.We would like to thank PAQ Research agency for sharing data from the “Life during the Pandemic” panel survey with us. Palguta gratefully acknowledges financial support from the Community of Madrid via grants 2017/T2-SOC-5363 and EPUC3M11 (V PRICIT). Levínsky was supported by the Ministry of Education, Youth and Sports of the Czech Republic through the project SHARE–CZ+ (CZ.02.1.01/0.0/0.0/16_013/0001740)

Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 3: OSSA integrated logistics support planning document

Guidance in preparing and updating an integrated logistics support plan (ILSP) is given. Clear, concise, and detailed instructions are provided on the preparation and content of an ILSP in order to ensure a quality document that reflects total program requirements

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This thesis in political economy considers the concept of strategic optimisation of voting behaviour under imperfect information. Under strategic voting we understand an act of voting for other than voter s best preferred (order of) alternatives. Motivation for this thesis comes from the empirically witnessed fact that a substantial portion of the electorate votes for their second or third best preferred alternatives, seeing that their most preferred alternatives face in expectation low probabilities of voting success. At other instances, the voters vote strategically with the intentions of strengthening the coalitional partners to their best choices or to weaken the coalitional partners of the undesired parties. Despite to the evident individual rationality of the strategic voting, strategic voting is typically socially suboptimal. Strategic voting leads to social choices that do not reflect the truthful preferences of the public. Via a series of computation-based simulations the thesis studies the relative vulnerability of the most common voting procedures to strategic manipulation. The thesis categorizes these voting procedures by their degree of susceptibility to voting manipulation. By standard econometric techniques it confirms that strategic voting is most threatening in small groups,...Práce z oblasti politické ekonomie se zabývá schopností voli e strategicky optimalizovat svoje voli ské chování v podmínkách nedokonalé informovanosti. Pod strategickým hlasováním práce rozumí odevzdání voli ských hlas jiné alternativ , ne voli up ímn preferuje. Motivací práce je empiricky pozorovatelný fakt, e nezanedbatelná ást voli hlasuje za svou druhou anebo t etí nejlep í alternativu, proto e první nejlep í alternativa nemusí mít vysokou nad ji na vít zství. Jindy voli i hlasují pro koali ní partnery ke svým alternativám nebo v snaze oslabit koali ní potenciál ne ádoucích stran. Naproti tomu, e strategické hlasování je individuáln racionální, spole ensky je ne ádoucí. Strategické hlasování toti asto vede k rozhodnutím, která neodrá ejí skute né preference voli . Práce pomocí po íta ových simulací voli ských preferencí zkoumá odolnost nejpou ívan j ích volebních procedur v i strategické manipulaci v hlasování. Se azuje tyto procedúry od nejmanipulovateln j í a po nejmén manipulovatelnou. Pomocí standardních ekonometrických metod potvrzuje, e strategické hlasování je nejkriti t j í p i malém po tu hlasujících, typicky v komisích, p edstavenstvech anebo jiných malých kolektivních orgánech. Dále práce opou tí p edpoklad dokonalé informovanosti, kritický pro Gibbard- Satterthwaith v teorém nemo...Institut ekonomických studiíInstitute of Economic StudiesFaculty of Social SciencesFakulta sociálních vě

Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 4: Supportability analysis of the 1.8m centrifuge

Supportability issues for the 1.8 meter centrifuge in the Life Science Research Facility are addressed. The analysis focuses on reliability and maintainability and the potential impact on supportability and affordability. Standard logistics engineering methodologies that will be applied to all Office of Space Science and Applications' (OSSA) payload programs are outlined. These methodologies are applied to the 1.8 meter centrifuge

Népbíróságok a magyar bírósági szervezetrendszerben

A népbíráskodás olyan bíróság által történő igazságszolgáltatás, amelyben az eljáró bírók valamennyien vagy többségében nem szakképzett bírók, hanem jogi képesítéssel nem rendelkező és a bírói tevékenységet hivatásszerűen nem gyakorló személyek. Kivételesen előfordulhat, hogy az igazságszolgáltatásban ideiglenesen részt vevő személy rendelkezik jogi képesítéssel, így a definíció legfőbb kritériuma, hogy az ítélkezésben bírói státuszba nem tartozó és hivatásszerűen igazságszolgáltatással nem foglalkozó személyek vegyenek részt. Az intézmény célja, hogy a helyes ítélőképességet és életismeretet a jogi szakképzettség esetleges egyoldalúsága ne befolyásolja, és ezáltal kevésbé merevvé tegye a jogszabályok alkalmazását

Giant convecting mud balls of the early solar system

Carbonaceous asteroids may have been the precursors to the terrestrial planets, yet despite their importance, numerous attempts to model their early solar system geological history have not converged on a solution. The assumption has been that hydrothermal alteration was occurring in rocky asteroids with material properties similar to meteorites. However, these bodies would have accreted as a high-porosity aggregate of igneous clasts (chondrules) and fine-grained primordial dust, with ice filling much of the pore space. Short-lived radionuclides melted the ice, and aqueous alteration of anhydrous minerals followed. However, at the moment when the ice melted, no geological process had acted to lithify this material. It would have been a mud, rather than a rock. We tested the effect of removing the assumption of lithification. We find that if the body accretes unsorted chondrules, then large-scale mud convection is capable of producing a size-sorted chondrule population (if the body accretes an aerodynamically sorted chondrule population, then no further sorting occurs). Mud convection both moderates internal temperature and reduces variation in temperature throughout the object. As the system is thoroughly mixed, soluble elements are not fractionated, preserving primitive chemistry. Isotopic and redox heterogeneity in secondary phases over short length scales is expected, as individual particles experience a range of temperature and water-rock histories until they are brought together in their final configuration at the end of convection. These results are consistent with observations from aqueously altered meteorites (CI and CM chondrites) and spectra of primitive asteroids. The “mudball” model appears to be a general solution: Bodies spanning a ×1000 mass range show similar behavior

Fluid evolution in CM carbonaceous chondrites tracked through the oxygen isotopic compositions of carbonates

The oxygen isotopic compositions of calcite grains in four CM carbonaceous chondrites have been determined by NanoSIMS, and results reveal that aqueous solutions evolved in a similar manner between parent body regions with different intensities of aqueous alteration. Two types of calcite were identified in Murchison, Mighei, Cold Bokkeveld and LaPaz Icefield 031166 by differences in their petrographic properties and oxygen isotope values. Type 1 calcite occurs as small equant grains that formed by filling of pore spaces in meteorite matrices during the earliest stages of alteration. On average, the type 1 grains have a δ18O of ∼32–36‰ (VSMOW), and Δ17O of between ∼2‰ and −1‰. Most grains of type 2 calcite precipitated after type 1. They contain micropores and inclusions, and have replaced ferromagnesian silicate minerals. Type 2 calcite has an average δ18O of ∼21–24‰ (VSMOW) and a Δ17O of between ∼−1‰ and −3‰. Such consistent isotopic differences between the two calcite types show that they formed in discrete episodes and from solutions whose δ18O and δ17O values had changed by reaction with parent body silicates, as predicted by the closed-system model for aqueous alteration. Temperatures are likely to have increased over the timespan of calcite precipitation, possibly owing to exothermic serpentinisation. The most highly altered CM chondrites commonly contain dolomite in addition to calcite. Dolomite grains in two previously studied CM chondrites have a narrow range in δ18O (∼25–29‰ VSMOW), with Δ17O ∼−1‰ to −3‰. These grains are likely to have precipitated between types 1 and 2 calcite, and in response to a transient heating event and/or a brief increase in fluid magnesium/calcium ratios. In spite of this evidence for localised excursions in temperature and/or solution chemistry, the carbonate oxygen isotope record shows that fluid evolution was comparable between many parent body regions. The CM carbonaceous chondrites studied here therefore sample either several parent bodies with a very similar initial composition and evolution or, more probably, a single C-type asteroid

Constraining Ceres' interior from its Rotational Motion

Context. Ceres is the most massive body of the asteroid belt and contains about 25 wt.% (weight percent) of water. Understanding its thermal evolution and assessing its current state are major goals of the Dawn Mission. Constraints on internal structure can be inferred from various observations. Especially, detailed knowledge of the rotational motion can help constrain the mass distribution inside the body, which in turn can lead to information on its geophysical history. Aims. We investigate the signature of the interior on the rotational motion of Ceres and discuss possible future measurements performed by the spacecraft Dawn that will help to constrain Ceres' internal structure. Methods. We compute the polar motion, precession-nutation, and length-of-day variations. We estimate the amplitudes of the rigid and non-rigid response for these various motions for models of Ceres interior constrained by recent shape data and surface properties. Results. As a general result, the amplitudes of oscillations in the rotation appear to be small, and their determination from spaceborne techniques will be challenging. For example, the amplitudes of the semi-annual and annual nutations are around ~364 and ~140 milli-arcseconds, and they show little variation within the parametric space of interior models envisioned for Ceres. This, combined with the very long-period of the precession motion, requires very precise measurements. We also estimate the timescale for Ceres' orientation to relax to a generalized Cassini State, and we find that the tidal dissipation within that object was probably too small to drive any significant damping of its obliquity since formation. However, combining the shape and gravity observations by Dawn offers the prospect to identify departures of non-hydrostaticity at the global and regional scale, which will be instrumental in constraining Ceres' past and current thermal state. We also discuss the existence of a possible Chandler mode in the rotational motion of Ceres, whose potential excitation by endogenic and/or exogenic processes may help detect the presence of liquid reservoirs within the asteroid.Comment: submitted to Astronomy and Astrophysic

The oxygen isotope evolution of parent body aqueous solutions as recorded by multiple carbonate generations in the Lonewolf Nunataks 94101 CM2 carbonaceous chondrite

The CM2 carbonaceous chondrite LON 94101 contains aragonite and two generations of calcite that provide snapshots of the chemical and isotopic evolution of aqueous solutions during parent body alteration. Aragonite was the first carbonate to crystallize. It is rare, heterogeneously distributed within the meteorite matrix, and its mean oxygen isotope values are δ18O 39.9±0.6‰, Δ17O -0.3±1.0‰ (1σ). Calcite precipitated very soon afterwards, and following a fall in solution Mg/Ca ratios, to produce small equant grains with a mean oxygen isotope value of δ18O 37.5±0.7‰, Δ17O 1.4±1.1‰ (1σ). These grains were partially or completely replaced by serpentine and tochilinite prior to precipitation of the second generation of calcite, which occluded an open fracture to form a millimeter-sized vein, and replaced anhydrous silicates within chondrules and the matrix. The vein calcite has a mean composition of δ18O 18.4±0.3‰, Δ17O -0.5±0.5‰ (1σ). Petrographic and isotopic results therefore reveal two discrete episodes of mineralization that produced Ca-carbonates with contrasting δ18O, but whose Δ17O values are indistinguishable within error. The aragonite and equant calcite crystallized over a relatively brief period early in the aqueous alteration history of the parent body, and from static fluids that were evolving chemically in response to mineral dissolution and precipitation. The second calcite generation crystallized from solutions of a lower Δ17O, and a lower δ18O and/or higher temperature, which entered LON 9410 via a fracture network. As two generations of calcite whose petrographic characteristics and oxygen isotopic compositions are similar to those in LON 94101 occur in at least one other CM2, multiphase carbonate mineralization could be the typical outcome of the sequence of chemical reactions during parent body aqueous alteration. It is equally possible however that the second generation of calcite in formed in response to an event such as impact fracturing and concomitant fluid mobilisation that affected a large region of the common parent body of several CM2 meteorites. These findings show that integrated petrographic, chemical and isotopic studies can provide new insights into the mechanisms of parent body alteration including the spatial and temporal dynamics of the aqueous system