3,608 research outputs found

    The concepts of surveillance and sousveillance: A critical analysis

    Get PDF
    The concept of surveillance has recently been complemented by the concept of sousveillance. Neither term, however, has been rigorously defined, and it is particularly unclear how to understand and delimit sousveillance. This article sketches a generic definition of surveillance and proceeds to explore various ways in which we might define sousveillance, including power differentials, surreptitiousness, control, reciprocity, and moral valence. It argues that for each of these ways of defining it, sousveillance either fails to be distinct from surveillance or to provide a generally useful concept. As such, the article concludes that academics should avoid the neologism, and simply clarify what sense of surveillance is at stake when necessary

    The Ethics of Police Body-Worn Cameras

    Get PDF
    Over the past decade, police departments in many countries have experimented with and increasingly adopted the use of police body-worn cameras. This article aims to examine the moral issues raised by the use of PBWCs, and to provide an overall assessment of the conditions under which the use of PBWCs is morally permissible. It first reviews the current evidence for the effects of using PBWCs. On the basis of this review the article sets out a teleological argument for the use of PBWCs. The final two sections of the article review two deontological objections to the use of PBWCs: the idea that use of PBWCs is based on or expresses disrespectful mistrust, and the idea that the use of PBWCs violates a right to privacy. The article argues that neither of these objections is persuasive, and concludes that we should conditionally accept and support the use of PBWCs

    The teleological account of proportional surveillance

    Get PDF
    This article analyses proportionality as a potential element of a theory of morally justified surveillance, and sets out a teleological account. It draws on conceptions in criminal justice ethics and just war theory, defines teleological proportionality in the context of surveillance, and sketches some of the central values likely to go into the consideration. It then explores some of the ways in which deontologists might want to modify the account and illustrates the difficulties of doing so. Having set out the account, however, it considers whether the proportionality condition is necessary to a theory of morally justified surveillance. The article concludes that we need and should apply only a necessity condition, but notes that proportionality considerations may retain some use in in practice, as a form of coarse‐grained filter applied before assessing necessity when deliberating the permissibility of potential forms of surveillance

    Exploring a Mechanism Underlying Stereotype Threat in ADHD

    Get PDF

    JANNAF liquid rocket combustion instability panel research recommendations

    Get PDF
    The Joint Army, Navy, NASA, Air Force (JANNAF) Liquid Rocket Combustion Instability Panel was formed in 1988, drawing its members from industry, academia, and government experts. The panel was charted to address the needs of near-term engine development programs and to make recommendations whose implementation would provide not only sufficient data but also the analysis capabilities to design stable and efficient engines. The panel was also chartered to make long-term recommendations toward developing mechanistic analysis models that would not be limited by design geometry or operating regime. These models would accurately predict stability and thereby minimize the amount of subscale testing for anchoring. The panel has held workshops on acoustic absorbing devices, combustion instability mechanisms, instability test hardware, and combustion instability computational methods. At these workshops, research projects that would meet the panel's charter were suggested. The JANNAF Liquid Rocket Combustion Instability Panel's conclusions about the work that needs to be done and recommendations on how to approach it, based on evaluation of the suggested research projects, are presented

    JANNAF Liquid Rocket Combustion Instability Panel Research Recommendations

    Get PDF
    The Joint Army, Navy, NASA, Air Force (JANNAF) Liquid Rocket Combustion Instability Panel was formed in 1988, drawing its members from industry, academia, and government experts. The panel was chartered to address the needs of near-term engine development programs and to make recommendations whose implementation would provide not only sufficient data but also the analysis capabilities to design stable and efficient engines. The panel was also chartered to make long-term recommendations toward developing mechanistic analysis models that would not be limited by design geometry or operating regime. These models would accurately predict stability and thereby minimize the amount of subscale testing for anchoring. The panel has held workshops on acoustic absorbing devices and combustion instability computational methods. At these workshops, research projects that would meet the panel's charter were suggested. The panel's conclusions about the work that needs to be done and recommendations on how to approach it, based on evaluation of the suggested research projects, are presented

    Coaxial injector spray characterization using water/air as simulants

    Get PDF
    Quantitative information about the atomization of injector sprays is required to improve the accuracy of computational models that predict the performance and stability of liquid propellant rocket engines. An experimental program is being conducted at NASA-Lewis to measure the drop size and velocity distributions in shear coaxial injector sprays. A phase/Doppler interferometer is used to obtain drop size data in water air shear coaxial injector sprays. Droplet sizes and axial component of droplet velocities are measured at different radii for various combinations of water flow rate, air flow rate, injector liquid jet diameter, injector annular gap, and liquid post recess. Sauter mean diameters measured in the spray center 51 mm downstream of the liquid post tip range from 28 to 68 microns, and mean axial drop velocities at the same location range from 37 to 120 m/s. The shear coaxial injector sprays show a high degree of symmetry; the mean drop size and velocity profiles vary with liquid flow rate, post recess, and distance from the injector face. The drop size data can be used to estimate liquid oxygen/hydrogen spray drop sizes by correcting property differences between water-air and liquid oxygen/hydrogen

    A comparison of analytical results for 20 K LOX/hydrogen instabilities

    Get PDF
    Test data from NASA Lewis' Effect of Thrust Per Element on Combustion Stability Characteristics of Hydrogen-Oxygen Rocket Engines test program are used to validate two recently released stability analysis tools. The first tool is a design methodology called ROCCID (ROCket Combustor Interactive Design). ROCCID is an interactive design and analysis methodology that uses existing performance and combustion stability analysis codes. The second tool is HICCIP (High frequency Injection Coupled Combustion Instability Program). HICCIP is a recently developed combustion stability analysis model. Using a matrix of models, results from analytic comparisons with 20 K LOX/H2 experimental data are presented

    Effect of model selection on combustor performance and stability predictions using ROCCID

    Get PDF
    The ROCket Combustor Interactive Design (ROCCID) methodology is an interactive computer program that combines previously developed combustion analysis models to calculate the combustion performance and stability of liquid rocket engines. Test data from 213 kN (48,000 lbf) Liquid Oxygen (LOX)/RP-1 combustor with an O-F-O (oxidizer-fuel-oxidizer) triplet injector were used to characterize the predictive capabilities of the ROCCID analysis models for this injector/propellant configuration. Thirteen combustion performance and stability models were incorporated into ROCCID, and ten of them, which have options for triplet injectors, were examined. Calculations using different combinations of analysis models, with little or no anchoring, were carried out on a test matrix of operating combinations matching those of the test program. Results of the computer analyses were compared to test data, and the ability of the model combinations to correctly predict combustion stability or instability was determined. For the best model combination(s), sensitivity of the calculations to fuel drop size and mixing efficiency was examined. Error in the stability calculations due to uncertainty in the pressure interaction index (N) was examined. The recommended model combinations for this O-F-O triplet LOX/RP-1 configuration are proposed

    Bestimmung von Glycerophospholipid gebundenen Fettsäuren in Erythrozyten und Vergleich des Einbaus von Docosahexaensäure in Glycerophospholipide aus Plasma, Erythrozyten und Wangenschleimhautzellen

    Get PDF
    Unsere Forschungsgruppe hat eine neue, sensitive und robuste Methode entwickelt, um selektiv die Fettsäuren der Glycerophospholipidfraktion im Plasma zu bestimmen, welche nur wenig vom postprandialen Status des Probanden beeinflusst werden. Bei diesem neuen Verfahren wird die konventionelle Lipidextraktion und deren Auftrennung durch eine methanolische Ausfällung der Proteine mit zusätzlicher Ausfällung von Triglyceriden und Cholesterinestern ersetzt. In Kombination mit basenkatalysierter Synthese von Methylestern bei Raumtemperatur wird die ausschließliche Umesterung der Glycerophopholipid (GPL) Fettsäuren gesichert. In der Vergangenheit hat sich gezeigt, dass sich dieses Verfahren nicht einfach von Plasma auf Erythrozyten übertragen lässt, sodass es notwendig war, die Anwendbarkeit der Plasma-GPL Methode auf Erythrozyten zu überprüfen, zu optimieren und zu validieren, bevor sie in klinischen Studien Anwendung finden kann. Im Rahmen dieser Untersuchung bestimmten wir auch den Omega-3-Index und verglichen diese mit in der Literatur beschriebenen Werten. Außerdem haben wir eine robuste Methode für die Analyse von Wangenschleimhaut Glycerophopholipid (GPL) gebundenen Fettsäuren entwickelt, welche nur wenig Probenmaterial benötigt und einfach anzuwenden ist. Die genannten Methoden zur Extraktion von GPL wurden im Rahmen einer klinischen Interventionsstudie evaluiert. Dabei wurden vor allem der Docosahexanensäure(DHA)-Anstieg im zeitlichen Verlauf der Studie zwischen den verschiedenen Kompartimenten Plasma, Erythrozyten und Wangenschleimhautzellen verglichen und Korrelationen berechnet, um eine Aussage darüber treffen zu können, welcher Biomarker, welche Änderungen widerspiegelt und wie geeignet die Analyse von GPL der Fettsäuren im Vergleich zu langjährig etablierten Markern, wie Gesamt-Phospholipide ist
    corecore