623 research outputs found

    Machiavelli's Politics and Critical Theory of Technology

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    Este artículo tiene cuatro partes. Primero, es una discusión de la teoría crítica de la tecnología de Andrew Feenberg en su libro Questioning Technology. Se defiende que la teoría de Feenberg es parecida, a grandes rasgos, a la teoría política de Maquiavelo, siendo posible una comparación con su filosofía política. En segundo lugar, se discute, por tanto, la filosofía política de Maquiavelo, en particular su descripción de la constitución de la sociedad. Tercero, se plantea la relación entre la virtud y el mundo natural según este autor. En último lugar, se argumenta que esta comparación saca a la luz algunos problemas para la teoría crítica de Feenberg. Este autor sostiene una política y una tecnología de la liberación, mientras que Maquiavelo indica que la política (y la tecnología) está siempre ligada a la coerción.This paper has four major parts. First is a discussion of the critical theory of technology offered by Andrew Feenberg in his book, Questioning Technology. I argue that Feenberg’s theory is similar, in important respects, to the political theory of Machiavelli and that consequently, a comparison of the political philosophy of Machiavelli is possible. Second, I discuss the political philosophy of Machiavelli, in particular his description of the foundation of society. Third I discuss the relationship between virtue and the natural world according to Machiavelli. Fourth, I argue that this comparison reveals problems for the critical theory of Feenberg. Feenberg wants a politics and technology of liberation and Machiavelli shows that politics (and also technology) is always linked to coercion

    Conservation status of New Zealand freshwater invertebrates, 2013

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    The conservation status of 644 freshwater invertebrate taxa, across five Phyla, 28 Orders and 75 Families, was assessed using the New Zealand Threat Classification System (NZTCS) criteria. Forty-six species were ranked Nationally Critical, 11 Nationally Endangered and 16 Nationally Vulnerable. One hundred and seventy-two taxa were listed as Data Deficient. A full list is presented, along with summaries and brief notes on the most important changes. This list replaces all previous NZTCS lists for freshwater invertebrates

    IMPLEMENTING CONDITION-BASED MAINTENANCE PLUS AS A GROUND MAINTENANCE STRATEGY IN THE MARINE CORPS

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    In 2020, Marine Corps Order 4151.22 and Commandant White Letter 2–20 was published to implement Condition-Based Maintenance Plus (CBM+) as a ground maintenance strategy to improve operational availability and reduce life-cycle costs. The Fleet Marine Force is still operating under preventative and corrective maintenance strategies instead of CBM+ strategies. Organizational inertia, such as competing priorities, legacy processes, and inspections, has slowed the integration of CBM+ strategies. We reviewed key policy documents and interviewed fifteen subject-matter experts relevant to Marine Corps ground transport maintenance policies and practices. Based on this information, we conducted a thematic analysis using an organizational change approach to identify barriers and opportunities that impact CBM+ implementation. We found that immediate gains from CBM+ implementation in the Marine Corps can be achieved through a focus on people and process improvements while technology integration continues. The CBM+ strategy supports Force Design 2030 and Talent Management 2030 objectives and emphasizing this alignment can build momentum for CBM+. In this paper, we make six specific recommendations that apply organizational change concepts to enable effective CBM+ implementation as a ground maintenance strategy in the Marine Corps.NPS Naval Research ProgramThis project was funded in part by the NPS Naval Research Program.Major, United States Marine CorpsMajor, United States Marine CorpsApproved for public release. Distribution is unlimited

    Cyclopentadienylides

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    The thermal decomposition of 2,3,4,5-tetraphenyldiazocyclopentadiene in the presence of carbene acceptors having Group V and VI elements to give 2,3,4,5-tetraphenylcyclopentadienylides has been extended and the first example of a telluronium ylide has been prepared by this method. The procedure has also been extended to other substituted diazo-cyclopentadienes and various new phosphonium, arsonium and sulphonium ylides have been prepared. The reaction of diazocyclopentadienes with triphenylphosphine to give either phosphazines or phosphonium ylides has been studied and the reasons for the difference in reactivity of these diazo-compounds has been clarified to some extent. It has been shown that for phosphazine formation both lack of steric hindrance and the absence of an electron- donating group on the cyclopentadiene ring are required. The thermal reaction of diazocyclopentadienes is assumed to proceed via a carbene-type intermediate which is then attacked by the reagent present to give an ylide. This reaction can be catalysed by the presence of copper-bronze and, in this case, can be effected either under melt conditions or in solution. The stability of the carbenoid intermediate is demonstrated by its preferential reaction with triphenylarsine rather than with benzene, which is present as the solvent. The reaction of 2,5-diphenyldiazocyclopentadiene with triphenylarsine gives a rearranged 2,4-disubstituted product. The carbene-type intermediate in this case is presumed to rearrange before reaction with the triphenylarsine. Some cyclopentadienylidene triphenylphosphazines have been shown to decompose thermally in the presence of triphenylphosphine to give the related triphenylphosphonium ylides. Diazocyclopentadienes have been found to react with either hydrochloric or hydrobromic acid to give the monochloro or monobromo cyclopentadienes. The parent, unsubstituted triphenylarsonium cyclopentadienylide has been prepared by the reaction of triphenylarsine with dibromocyclopentene and basification of the bis-arsonium salt so formed. Its properties and reactions have been studied and are found to be similar to the analogous triphenylphosphonium ylide. The salt method for the preparation of cyclopentadienylides has also been investigated. Triphenylarsine has been shown to react with 5-bromo-1,2,3-triphenylcyclopentadiene in solution at room temperature to give the hydrobromide salt of the ylide. Various sulphides also reacted with the bromo-compound to give, in most cases, unexpected products. The reactions of the cyclopentadienylides prepared with aldehydes have been investigated and the results are in line with previous findings. The cyclopentadienylides also readily undergo electrophilic substitution on the five-membered ring. The reaction proceeds preferentially at the 2(5)-position

    Midlatitude thermospheric wind and temperature: networked Fabry-Perot interferometer observations and radiative transfer modeling

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    This dissertation presents studies of the midlatitude and low-latitude thermosphere, primarily using networks of Fabry-Perot interferometers (FPIs). First, we describe an algorithm which estimates thermospheric line-of-sight wind and temperature from raw FPI data. This new algorithm has the advantage over previous work in that it provides accurate temperature estimates and uncertainties. We then present a novel regularization-based technique to estimate the thermospheric wind field from an FPI network's line-of-sight wind measurements. This technique makes no explicit assumptions about the functional form of the wind field, and instead lets the data inform the shape. We apply this technique to study the wind dynamics associated with the equatorial midnight temperature maximum, finding direct evidence of a converging wind field during its development. Next, we apply this technique to study the midlatitude thermospheric response to the geomagnetic storm of 01-02 Oct 2013. Though the horizontal wind and temperature measurements corroborate previous observations and theory in a broad sense, the downward vertical winds measured by six independent FPIs are unreasonably large (>100 m/s) and sustained (5 hours). A superposed epoch analysis of 15 different storms shows that such downward winds are commonly measured during the main phase. Using radiative transfer modeling, we show that these vertical winds are not real, and instead are artifacts of the scattering of airglow radiation in the lower atmosphere. This is the likely explanation for the large midlatitude vertical winds and horizontal convergences previously reported in the literature. We also show that some of the vertical winds repeatedly observed at equatorial latitudes may be explained as artifacts of atmospheric scattering. These results suggest that the effects of the lower atmosphere should be accounted for in any quantitative ground-based airglow measurement

    Decontamination Foam for Chemical Spill Mitigation

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    The release of hazardous chemicals poses a threat to individuals in the area of a release and to responders who attempt to limit the damage of the release. For a liquid phase spill, the most common decontamination technology is a sodium hypochlorite and water solution. Although this solution has been proven effective against a variety of contaminants, it also has a host of drawbacks. Therefore, there is a need for an industrial decontamination solution that is noncorrosive, nontoxic, nonflammable, and environmentally safe. The military has developed a solution using hydrogen peroxide as well as a quaternary ammonium complex that is currently used to decontaminate chemical and biological warfare agents, which may be adapted to fit the needs in industry. Additionally, turning this liquid solution into foam may prove even more effective while reducing the cost. In order to test foam application, a foam generator was built in house. This foam generator was newly designed and built with features allowing for the study of foam production. A protected derivative of cysteine was chosen as the surrogate for a hazardous industrial contaminant. This derivative allowed for the study of non-polar decontamination due to the attachment of non-polar functional groups to the cysteine molecule. Liquid phase decontamination was conducted using both decontamination foam solution and decontamination solution without surfactant. All reaction analysis was carried out using GC-MS to determine the extent of reaction. The decontamination effect was conducted using the foam generator and a test apparatus, which were able to show the successful decontamination of the contaminant in as little as 20 minutes

    Thermospheric Weather as Observed by Ground‐Based FPIs and Modeled by GITM

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    The first long‐term comparison of day‐to‐day variability (i.e., weather) in the thermospheric winds between a first‐principles model and data is presented. The definition of weather adopted here is the difference between daily observations and long‐term averages at the same UT. A year‐long run of the Global Ionosphere Thermosphere Model is evaluated against a nighttime neutral wind data set compiled from six Fabry‐Perot interferometers at middle and low latitudes. First, the temporal persistence of quiet‐time fluctuations above the background climate is evaluated, and the decorrelation time (the time lag at which the autocorrelation function drops to e−1) is found to be in good agreement between the data (1.8 hr) and the model (1.9 hr). Next, comparisons between sites are made to determine the decorrelation distance (the distance at which the cross‐correlation drops to e−1). Larger Fabry‐Perot interferometer networks are needed to conclusively determine the decorrelation distance, but the current data set suggests that it is ∼1,000 km. In the model the decorrelation distance is much larger, indicating that the model results contain too little spatial structure. The measured decorrelation time and distance are useful to tune assimilative models and are notably shorter than the scales expected if tidal forcing were responsible for the variability, suggesting that some other source is dominating the weather. Finally, the model‐data correlation is poor (−0.07 < ρ < 0.36), and the magnitude of the weather is underestimated in the model by 65%.Plain Language SummaryMuch like in the lower atmosphere, weather in the upper atmosphere is harder to predict than climate. Physics‐based models are becoming sophisticated enough that they can in principle predict the weather, and we present the first long‐term evaluation of how well a particular model, Global Ionosphere Thermosphere Model, performs. To evaluate the model, we compare it with a year of data from six ground‐based sites that measure the thermospheric wind. First, we calculate statistics of the weather, such as the decorrelation time, which characterizes how long weather fluctuations persist (1.8 hr in the data and 1.9 hr in the model). We also characterize the spatial decorrelation by comparing weather at different sites. The model predicts that the weather is much more widespread than the data indicates; sites that are 790 km apart have a measured correlation of 0.4, while the modeled correlation is 0.8. In terms of being able to actually predict a weather fluctuation on a particular day, the model performs poorly, with a correlation that is near zero at the low latitude sites, but reaches an average of 0.19 at the midlatitude sites, which are closer to the source that most likely dominates the weather: heating in the auroral zone.Key PointsA long‐term data‐model comparison of day‐to‐day thermospheric variability finds that GITM represents the weather poorly (−0.07 < ρ < 0.36)The average measured decorrelation time of 1.8 hr agrees with the modeled time of 1.9 hrThe weather in GITM contains too little spatial structure, when compared with the measured ∼1,000‐km decorrelation distancePeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148359/1/jgra54757_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148359/2/jgra54757.pd

    Cross-Reactivity in Skin Prick Test Results of Members within Pooideae Subfamily

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    Objective: Molecular similarities of grass pollen antigens have led to the view that cross-reactivity exists within members of the Pooideae subfamily of grasses. This has resulted in testing for only the most antigenically representative member of Pooideae, Timothy grass (Phleum pratense), despite little literature to support the claim that Phleum is the most representative member or that in vitro cross-reactivity correlates with in vivo cross-reactivity. The aim of the study was to determine if patients with allergic rhinitis symptoms and positive skin prick test results to meadow fescue (Festuca pratensis) also have positive results to Timothy grass. Study Design: Retrospective cross-sectional study. Setting: Tertiary care center in middle Missouri. Methods: A retrospective chart review identified patients ≥12 years old with a diagnosis of allergic rhinitis who underwent skin prick testing between March 2016 and July 2018, by using a search with CPT code 95004 (Current Procedural Terminology). Positive skin prick test results were based on wheal produced ≥3 mm than the negative control. Results: After review of 2182 charts, 1587 patients met criteria to test for Phleum and Festuca. In total, 1239 patients had a positive result for Phleum or Festuca. Of these, 479 (38.6%) tested positive for Festuca alone, while 342 (27.6%) and 418 (33.7%) tested positive for Phleum alone and Phleum+Festuca, respectively. Conclusion: Clinical cross-reactivity among Pooideae members may not be as complete as traditionally thought. P pratense may not be the most antigenically representative subfamily member, and other grasses may need to be included in skin prick testing

    Tracer diffusion of selected cations in single crystal MgO

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    The diffusion of various cations in single crystal magnesium oxide has been measured over a wide temperature range using radioactive tracers and a sectioning technique. Self-diffusion studies may be interpreted in such a manner as to suggest that the enthalpy of formation of a Schottky defect in this oxide is (3.8 ± 0.3) eV, while the enthalpy of motion of a cation vacancy is (1.56 ± 0.08) eV. Intrinsic diffusion occurs above 1900 °C, with a 'knee' temperature, for the material used here, of 1800 °C. Impurityprecipitation-controlled diffusion has been observed below 1500 °C. Atmosphere, apparently, has no effect on diffusion rates. The radius of a diffusing ion seems to have no detectable influence on its enthalpy of motion in MgO, whereas electronic properties (polarisability and charge) are evidently important in this respect. Most impurities diffuse by a vacancy mechanism, but beryllium diffusion may possibly proceed via interstitial sites. Short-circuit enhancement of diffusion in MgO involves two (or more) mechanisms, one being dependent on the presence of impurity precipitates at dislocations, while the other is independent of this phenomenon and operates for ions which are large compared with the host cation. Such enhancement is believed to have obscured precipitationcontrolled lattice diffusion in many studies and also accounts for the variation in activation energies reported by different authors for the diffusion of a given impurity
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