Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales, Class III

This report describes the evaluation, design, and implementation of a DOE funded CO2 pilot project in the Lost Hills Field, Kern County, California. The pilot consists of four inverted (injector-centered) 5-spot patterns covering approximately 10 acres, and is located in a portion of the field, which has been under waterflood since early 1992. The target reservoir for the CO2 pilot is the Belridge Diatomite. The pilot location was selected based on geology, reservoir quality and reservoir performance during the waterflood. A CO2 pilot was chosen, rather than full-field implementation, to investigate uncertainties associated with CO2 utilization rate and premature CO2 breakthrough, and overall uncertainty in the unproven CO2 flood process in the San Joaquin Valley

ADVANCED RESERVOIR CHARACTERIZATION IN THE ANTELOPE SHALE TO ESTABLISH THE VIABILITY OF CO2 ENHANCED OIL RECOVERY IN CALIFORNIA'S MONTEREY FORMATION SILICEOUS SHALES

During the 1st quarter of 2002 CO{sub 2} injection remained shut-in as we continued to inject water and wait for the producing wells to be repaired. This report is a summary of the CO{sub 2} pilot execution that occurred during the 1st quarter of 2002

An embedded machine vision system for an in-line quality check of assembly processes

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Approximate Down-Sampling Strategy for Power-Constrained Intelligent Systems

In modern power constrained applications, as with most of those belonging to the Internet-of-Things world, custom hardware supports are ever more commonly adopted to deploy artificial intelligence algorithms. In these operating environments, limiting the power dissipation as much as possible is mandatory, even at the expense of reduced computational accuracy. In this paper we propose a novel prediction method to identify potential predominant features in convolutional layers followed by down-sampling layers, thus reducing the overall number of convolution calculations. This approximation down-sampling strategy has been exploited to design a custom hardware architecture for the inference of Convolutional Neural Network (CNN) models. The proposed approach has been applied to several benchmark CNN models and we achieved an overall energy saving of up to 70% with an accuracy loss lower than 3%, with respect to baseline designs. Performed experiments demonstrate that, when adopted to infer the Visual Geometry Group-16 (VGG16) network model, the proposed architecture implemented on a Xilinx Z-7045 chip and on the STM 28nm process technology dissipates only 680 and 21.9 mJ/frame, respectively. In both cases, the novel design overcomes several state-of-the-art competitors in terms of energy-accuracy drop product

A Microchip Integrated Sensor for the Monitoring of High Concentration Photo-voltaic Solar Modules

Abstract A CMOS sensor fabricated in 0.35μm technology, specifically designed for the monitoring of High Concentration Photo-Voltaic (HCPV) modules, is presented. The microchip was designed to monitor temperature and illumination of each solar cell in a module. Temperature is measured by monitoring the base-emitter voltage of two coupled, diode connected, bipolar transistors, while the illumination sensor is an integrated p-n junction photodiode. A custom communication protocol is implemented in the chip to allow the sharing of a two-wire communication resource among the cells

Confirming the gamma-ray burst spectral-energy correlations in the era of multiple time breaks

We test the spectral-energy correlation including the new bursts detected (mostly) by Swift with firm measurements of their redshifts and peak energy. The problem of identifying the jet breaks is discussed in the complex and multibreak/flaring X-ray light curves observed by Swift. We use the optical data as the most reliable source for the identification of the jet break, since the X-ray flux may be produced by a mechanism different from the external shocks between the fireball and the circumburst medium, which are responsible for the optical afterglow. We show that the presence of an underlying SN event in XRF 050416A requires a break to occur in the afterglow optical light curve at around the expected jet break time. The possible presence of a jet break in the optical light curve of GRB 050401 is also discussed. We point out that, for measuring the jet break, it is mandatory that the optical light curve extends after the epoch where the jet break is expected. The interpretation of the early optical breaks in GRB 050922C and GRB 060206 as jet breaks is controversial because they might instead correspond to the flat-to-steep decay transition common in the early X-ray light curves. All the 16 bursts coming from Swift are consistent with the E_p-E_gamma and E_p-E_iso-t_jet correlation. No outlier is found to date. Moreover, the small dispersion of these correlations, confirmed also by the Swift bursts, strengthens the case of using GRBs as standard candles.Comment: 12 pages, 1 table, 8 figures. Accepted for publication in A&

Swift-UVOT detection of GRB 050318

We present observations of GRB 050318 by the Ultra-Violet and Optical Telescope (UVOT) on-board the Swift observatory. The data are the first detections of a Gamma Ray Burst (GRB) afterglow decay by the UVOT instrument, launched specifically to open a new window on these transient sources. We showcase UVOTs ability to provide multi-color photometry and the advantages of combining UVOT data with simultaneous and contemporaneous observations from the high-energy detectors on the Swift spacecraft. Multiple filters covering 1,800-6,000 Angstroms reveal a red source with spectral slope steeper than the simultaneous X-ray continuum. Spectral fits indicate that the UVOT colors are consistent with dust extinction by systems at z = 1.2037 and z = 1.4436, redshifts where absorption systems have been pre-identified. However, the data can be most-easily reproduced with models containing a foreground system of neutral gas redshifted by z = 2.8 +/- 0.3. For both of the above scenarios, spectral and decay slopes are, for the most part, consistent with fireball expansion into a uniform medium, provided a cooling break occurs between the energy ranges of the UVOT and Swifts X-ray instrumentation.Comment: 15 pages, 4 figures, ApJ Letters, in pres

Diversity of multiwavelength emission bumps in the GRB 100219A afterglow

Context. Multi-wavelength observations of gamma-ray burst (GRB) afterglows provide important information about the activity of their central engines and their environments. In particular, the short timescale variability, such as bumps and/or rebrightening features visible in the multi-wavelength light curves, is still poorly understood. Aims. We analyze the multi-wavelength observations of the GRB100219A afterglow at redshift 4.7. In particular, we attempt to identify the physical origin of the late achromatic flares/bumps detected in the X-ray and optical bands. Methods. We present ground-based optical photometric data and Swift X-ray observations on GRB100219A. We analyzed the temporal behavior of the X-ray and optical light curves, as well as the X-ray spectra. Results. The early flares in the X-ray and optical light curves peak simultaneously at about 1000 s after the burst trigger, while late achromatic bumps in the X-ray and optical bands appear at about 20000 s after the burst trigger. These are uncommon features in the afterglow phenomenology. Considering the temporal and spectral properties, we argue that both optical and X-ray emissions come from the same mechanism. The late flares/bumps may be produced by late internal shocks from long-lasting activity of the central engine. An off-axis origin for a structured jet model is also discussed to interpret the bump shapes. The early optical bump can be interpreted as the afterglow onset, while the early X-ray flare could be caused by the internal activity. GRB 100219A exploded in a dense environment as revealed by the strong attenuation of X-ray emission and the optical-to-X-ray spectral energy distribution.Comment: A&A accepte

A complete sample of bright Swift Gamma-Ray Bursts: X-ray afterglow luminosity and its correlation with the prompt emission

We investigate wheter there is any correlation between the X-ray afterglow luminosity and the prompt emission properties of a carefully selected sub-sample of bright Swift long Gamma-Ray Bursts (GRBs) nearly complete in redshift (~90%). Being free of selection effects (except flux limit), this sample provides the possibility to compare the rest frame physical properties of GRB prompt and afterglow emission in an unbiased way. The afterglow X-ray luminosities are computed at four different rest frame times (5 min, 1 hr, 11 hr and 24 hr after trigger) and compared with the prompt emission isotropic energy E_iso, the isotropic peak luminosity L_iso and the rest frame peak energy E_peak. We find that the rest frame afterglow X-ray luminosity do correlate with these prompt emission quantities, but the significance of each correlation decreases over time. This result is in agreement with the idea that the GRB X-ray light curve can be described as the result of a combination of different components whose relative contribution and weight change with time, with the prompt and afterglow emission dominating at early and late time, respectively. In particular, we found evidence that the plateau and the shallow decay phase often observed in GRB X-ray light curves are powered by activity from the central engine. The existence of the L_X-E_iso correlation at late times (t_rf > 11 hr) suggests a similar radiative efficiency among different bursts with on average about 6% of the total kinetic energy powering the prompt emission.Comment: 8 pages, 4 figures, 3 tables. Accepted for publication in MNRA

Swift captures the spectrally evolving prompt emission of GRB 070616

The origins of Gamma-ray Burst prompt emission are currently not well understood and in this context long, well-observed events are particularly important to study. We present the case of GRB 070616, analysing the exceptionally long-duration multipeaked prompt emission, and later afterglow, captured by all the instruments on-board Swift and by Suzaku WAM. The high energy light curve remained generally flat for several hundred seconds before going into a steep decline. Spectral evolution from hard to soft is clearly taking place throughout the prompt emission, beginning at 285 s after the trigger and extending to 1200 s. We track the movement of the spectral peak energy, whilst observing a softening of the low energy spectral slope. The steep decline in flux may be caused by a combination of this strong spectral evolution and the curvature effect. We investigate origins for the spectral evolution, ruling out a superposition of two power laws and considering instead an additional component dominant during the late prompt emission. We also discuss origins for the early optical emission and the physics of the afterglow. The case of GRB 070616 clearly demonstrates that both broadband coverage and good time resolution are crucial to pin down the origins of the complex prompt emission in GRBs.Comment: 13 pages, 11 figures (2 in colour), MNRAS accepte