586 research outputs found

    Fandubbing across time and space. From dubbing ‘by fans for fans’ to cyberdubbing

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    This chapter investigates a phenomenon that has received scant academic attention so far: fandubbing. To understand the extent and impact of this participatory practice in the current landscape, the chapter examines fandubbing origins and reflects on the needs met by fandubs at different times and contexts. The plethora of uses and motivations behind this phenomenon question the suitability of the term fandubbing. Against this backdrop, and drawing on Díaz-Cintas’s (2018) conception of “cybersubtitles”, the chapter advocates using the term cyberdubbing to reflect the wide range of non-traditional online dubbing practices so prevalent nowadays, including parodic and serious dubbings undertaken by fans, Internet users and digital influencers, be them professionals or amateurs

    *Socioeconomic Status and Ethnicity: How Does it Affect Civic Engagement?

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    This presentation will cover the someone\u27s civic engagement (voting, community outreach, etc.) and how it is effected by their socioeconomic status and ethnicity

    Translating reality TV into Spanish: when fast-food TV challenges AVT conventions

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    In Spain, as in other countries, reality TV seems to be a pervasive phenomenon, materialised in a myriad of domestic and foreign productions. The latter require interlingual translation, which in most cases takes the form of voice-over translation. Despite the prevalence of reality TV and voice-over translation in Spanish television, both fields are still widely underexplored. This article sets out to bridge this research gap by presenting an exploratory study of the translation of reality TV in Spain. To this end, it will first document the prevalence of foreign reality TV in Spanish TV schedules, to then explore the similarities and differences in traditional voice-over translation (i.e. used for documentary translation) versus voice-over translation for reality TV. The focus is on the different types of synchrony observed in voice-over translation, yet the discussion highlights other relevant issues (e.g. approaches to the translation of semi-spontaneous speech) and illustrates how this genre is challenging audiovisual translation (AVT) conventions, as well as blurring the boundaries between AVT modes

    The Impact of Harness Impedance on Hall Thruster Discharge Oscillations

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    Hall thrusters exhibit characteristic discharge voltage and current oscillations during steady-state operation. The lower frequency breathing-mode current oscillations are inherent to each thruster and could impact thruster operation and power processing unit (PPU) design. The design of the discharge output filter, in particular, the output capacitor is important because it supplies the high peak current oscillations that the thruster demands. However, space-rated, high-voltage capacitors are not readily available and can have significant mass and volume. So, it is important for a PPU designer to know what is the minimum amount of capacitance required to operate a thruster. Through Simulation Program with Integrated Circuit Emphasis modeling and electrical measurements on the Hall Effect Rocket with Magnetic Shielding thruster, it was shown that the harness impedance between the power supply and the thruster is the main contributor towards generating voltage ripple at the thruster. Also, increasing the size of the discharge filter capacitor, as previously implemented during thruster tests, does not reduce the voltage oscillations. The electrical characteristics of the electrical harness between the discharge supply and the thruster is crucial to system performance and could have a negative impact on performance, life and operation

    The 10 kW power electronics for hydrogen arcjets

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    A combination of emerging mission considerations such as 'launch on schedule', resource limitations, and the development of higher power spacecraft busses has resulted in renewed interest in high power hydrogen arcjet systems with specific impulses greater than 1000 s for Earth-space orbit transfer and maneuver applications. Solar electric propulsion systems with about 10 kW of power appear to offer payload benefits at acceptable trip times. This work outlines the design and development of 10 kW hydrogen arcjet power electronics and results of arcjet integration testing. The power electronics incorporated a full bridge switching topology similar to that employed in state of the art 5 kW power electronics, and the output filter included an output current averaging inductor with an integral pulse generation winding for arcjet ignition. Phase shifted, pulse width modulation with current mode control was used to regulate the current delivered to arcjet, and a low inductance power stage minimized switching transients. Hybrid power Metal Oxide Semiconductor Field Effect Transistors were used to minimize conduction losses. Switching losses were minimized using a fast response, optically isolated, totem-pole gate drive circuit. The input bus voltage for the unit was 150 V, with a maximum output voltage of 225 V. The switching frequency of 20 kHz was a compromise between mass savings and higher efficiency. Power conversion efficiencies in excess of 0.94 were demonstrated, along with steady state load current regulation of 1 percent. The power electronics were successfully integrated with a 10 kW laboratory hydrogen arcjet, and reliable, nondestructive starts and transitions to steady state operation were demonstrated. The estimated specific mass for a flight packaged unit was 2 kg/kW

    NEXT Thruster Component Verification Testing

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    Component testing is a critical part of thruster life validation activities under NASA s Evolutionary Xenon Thruster (NEXT) project testing. The high voltage propellant isolators were selected for design verification testing. Even though they are based on a heritage design, design changes were made because the isolators will be operated under different environmental conditions including temperature, voltage, and pressure. The life test of two NEXT isolators was therefore initiated and has accumulated more than 10,000 hr of operation. Measurements to date indicate only a negligibly small increase in leakage current. The cathode heaters were also selected for verification testing. The technology to fabricate these heaters, developed for the International Space Station plasma contactor hollow cathode assembly, was transferred to Aerojet for the fabrication of the NEXT prototype model ion thrusters. Testing the contractor-fabricated heaters is necessary to validate fabrication processes for high reliability heaters. This paper documents the status of the propellant isolator and cathode heater tests

    Space Station Cathode Ignition Test Status at 32,000 Cycles

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    A plasma contactor system has been baselined for the International Space Station for structural potential control. An ignition procedure was developed for the plasma contactor hollow cathode assembly (HCA). To demonstrate the required 99% HCA ignition reliability over 6,000 cycles, an ignition test was conducted. An accelerated test procedure was employed to rapidly accumulate ignition cycles. The test procedure minimized the differences between accelerated and non-accelerated test results. The development HCA used in this test has achieved 32,000 ignitions to date. The HCA has been qualified for cyclic operation, which could reduce xenon consumption and extend the life of the plasma contactor system

    Recycle Requirements for NASA's 30 cm Xenon Ion Thruster

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    Electrical breakdowns have been observed during ion thruster operation. These breakdowns, or arcs, can be caused by several conditions. In flight systems, the power processing unit must be designed to handle these faults autonomously. This has a strong impact on power processor requirements and must be understood fully for the power processing unit being designed for the NASA Solar Electric Propulsion Technology Application Readiness program. In this study, fault conditions were investigated using a NASA 30 cm ion thruster and a power console. Power processing unit output specifications were defined based on the breakdown phenomena identified and characterized

    Power Electronics for a Miniaturized Arcjet

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    A 0.3 kW Power Processing Unit (PPU) was designed, tested on resistive loads, and then integrated with a miniaturized arcjet. The main goal of the design was to minimize size and mass while maintaining reasonable efficiency. In order to obtain the desired reductions in mass, simple topologies and control methods were considered. The PPU design incorporates a 50 kHz, current-mode-control, pulse-width-modulated (PWM), push-pull topology. An input voltage of 28 +/- 4V was chosen for compatibility with typical unregulated low voltage busses anticipated for smallsats. An efficiency of 0.90 under nominal operating conditions was obtained. The component mass of the PPU was 0.475 kg and could be improved by optimization of the output filter design. The estimated mass for a flight PPU based on this design is less than a kilogram

    Integration Testing of a Modular Discharge Supply for NASA's High Voltage Hall Accelerator Thruster

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    NASA s In-Space Propulsion Technology Program is developing a high performance Hall thruster that can fulfill the needs of future Discovery-class missions. The result of this effort is the High Voltage Hall Accelerator thruster that can operate over a power range from 0.3 to 3.5 kW and a specific impulse from 1,000 to 2,800 sec, and process 300 kg of xenon propellant. Simultaneously, a 4.0 kW discharge power supply comprised of two parallel modules was developed. These power modules use an innovative three-phase resonant topology that can efficiently supply full power to the thruster at an output voltage range of 200 to 700 V at an input voltage range of 80 to 160 V. Efficiencies as high as 95.9 percent were measured during an integration test with the NASA103M.XL thruster. The accuracy of the master/slave current sharing circuit and various thruster ignition techniques were evaluated
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