Feasibility model of an advanced crossed-field amplifier for space communication systems

Feasibility model of cross field amplifier for use in amplitude or frequency modulation transmitter

Study and determination of an optimum design for space utilized lithium doped solar cells Quarterly report

Recovery characteristics of electron irradiated, lithium doped, solar cell

A Multi-Wavelength Study of Sgr A*: The Role of Near-IR Flares in Production of X-ray, Soft γ\gamma-ray and Sub-millimeter Emission

(abridged) We describe highlights of the results of two observing campaigns in 2004 to investigate the correlation of flare activity in Sgr A* in different wavelength regimes, using a total of nine ground and space-based telescopes. We report the detection of several new near-IR flares during the campaign based on {\it HST} observations. The level of near-IR flare activity can be as low as $\sim0.15$ mJy at 1.6 $\mu$m and continuous up to about 40% of the total observing time. Using the NICMOS instrument on the {\it HST}, the {\it XMM-Newton} and CSO observatories, we also detect simultaneous bright X-ray and near-IR flare in which we observe for the first time correlated substructures as well as simultaneous submillimeter and near-IR flaring. X-ray emission is arising from the population of near-IR-synchrotron-emitting relativistic particles which scatter submillimeter seed photons within the inner 10 Schwarzschild radii of Sgr A* up to X-ray energies. In addition, using the inverse Compton scattering picture, we explain the high energy 20-120 keV emission from the direction toward Sgr A*, and the lack of one-to-one X-ray counterparts to near-IR flares, by the variation of the magnetic field and the spectral index distributions of this population of nonthermal particles. In this picture, the evidence for the variability of submillimeter emission during a near-IR flare is produced by the low-energy component of the population of particles emitting synchrotron near-IR emission. Based on the measurements of the duration of flares in near-IR and submillimeter wavelengths, we argue that the cooling could be due to adiabatic expansion with the implication that flare activity may drive an outflow.Comment: 48 pages, 12 figures, ApJ (in press

Modelling the adsorption-desorption behavior of CO2 in shales for permanent storage of CO2 and enhanced hydrocarbon extraction

Increasing global need for energy security has spurred a need for enhanced oil and gas recovery from unconventional reservoirs. From a carbon cycle point of view however, enhanced hydrocarbon extraction results in higher concentrations of CO 2 in the atmosphere, which is detrimental to the environment. Coupling the potential of storing CO 2 with gas and oil recovery is one approach to limit the rise in atmospheric CO 2 concentrations while allowing for subsurface hydrocarbon recovery. Over the past few years, shale gas and oil have emerged as one of the leading contributors to overall subsurface hydrocarbon recovery. In this study, we explore the potential of combining the adsorption of CO 2 with the enhanced recovery of CH 4 , and compare the results with water which is conventionally used for hydraulic fracturing. The adsorption-desorption behaviour is accounted for using published experimental Langmuir isotherm data. The model assumes a simplified fracture shape where the flow is one-dimensional and Darcy's law is obeyed. Key performance indicators include tonnes of CO 2 injected per scm CH 4 recovered, tonnes of H 2 O injected per scm CH 4 recovered and tonnes of CO 2 sequestered per tonne of CO 2 injected

Characterisation and Optimisation of a Real-Time Diesel engine model

Accurate real-time engine models are an essential step to allow the development of control algorithms in parallel to the development of engine hardware using hardware-in-the-loop applications. A physics-based model of the engine high-pressure air path and combustion chamber is presented. The model was parameterised using data from a small set of carefully selected operating conditions for a 2.0 l diesel engine. The model was subsequently validated over the complete engine operating map with exhaust gas recirculation and without exhaust gas recirculation. A high level of fit was achieved with R2 values above 0.94 for the mean effective pressure and above 0.99 for the air flow rate. The model run time was then reduced for real-time application by using forward differencing and single-precision floating-point numbers and by calculating the in-cylinder prediction for only a single cylinder. A further improvement of 25% in the run time was achieved by improving the submodels, including the strategic use of one-dimensional and two-dimensional look-up tables with optimised resolution. The model exceeds the performance of similar models in the literature, achieving a crank angle resolution of 0.5° at 4000 r/min. This simulation step size still yields good accuracy in comparison with a crank angle resolution of 0.1° and was validated against the experimental results from a New European Driving Cycle. The real-time model allows the development of control strategies before the engine hardware is available, meaning that more time can be spent to ensure that the engine can meet the performance and the emissions requirements over its full operating range

Assessing Sexual Orientation Symptoms In Obsessive-Compulsive Disorder: Development And Validation Of The Sexual Orientation Obsessions And Reactions Test (SORT)

Obsessive-compulsive disorder (OCD) includes many symptom presentations, which creates unique diagnostic challenges. Fears surrounding one’s sexual orientation are common within OCD (also called SO-OCD), but SO-OCD is consistently misdiagnosed by physicians and psychologists. To address this issue, we describe the development of a self-report measure for assessing SO-OCD to help distinguish OCD from distress caused by a sexual orientation identity crisis. The current paper details two studies that established the psychometric properties and clinical utility of this measure. In Study 1, the factor structure, validity, and reliability were examined for the measure’s 12 items in a sample of 1,673 university students. The results revealed a two-factor solution for the measure (Factor 1: Transformation Fears; Factor 2: Somatic Checking) and preliminary evidence of validity and reliability. In Study 2, the measure was tested with LGBTQ and heterosexual community samples and clinical samples of individuals with SO-OCD and other types of OCD. The two-factor solution and evidence of validity and reliability were supported in these samples. Cut-off points were established to distinguish between community members and SO-OCD sufferers, as well as between those experiencing SO-OCD and other types of OCD. Limitations and future directions are discussed