Coal-water slurry atomization characteristics

The overall objective of this work was to fully characterize the CWS fuel sprays of a medium-speed diesel engine injection system. Specifically, the spray plume penetration as a function of time was determined for a positive-displacement fuel injection system. The penetration was determined as a function of orifice diameter, coal loading, gas density in the engine, and fuel line pressure. Preliminary droplet information also was obtained. The results of this study will assist CWS engine development by providing much needed insight about the fuel spray. In addition, the results will aid the development and use of CWS engine cycle simulations which require information on the fuel spray characteristics

Coal-water slurry spray characteristics of a positive displacement fuel injection system

Experiments have been completed to characterized coal-water slurry sprays from a modified positive displacement fuel injection system of a diesel engine. The injection system includes an injection jerk pump driven by an electric motor, a specially designed diaphragm to separate the abrasive coal from the pump, and a single-hole fuel nozzle. The sprays were injected into a pressurized chamber equipped with windows. High speed movies and instantaneous fuel line pressures were obtained. For injection pressures of order 30 MPa or higher, the sprays were similar for coal-water slurry, diesel fuel and water. The time until the center core of the spray broke-up (break-up time) was determined from both the movies and from a model using the fuel line pressures. Results from these two independent procedures were in good agreement. For the base conditions, the break-up time was 0.58 and 0.50 ms for coal-water slurry and diesel fuel, respectively. The break-up times increased with increasing nozzle orifice size and with decreasing chamber density. The break-up time was not a function of coal loading for coal loadings up to 53%. Cone angles of the sprays were dependent on the operating conditions and fluid, as well as on the time and location of the measurement. For one set of cases studied, the time-averaged cone angle was 15.9{degree} and 16.3{degree} for coal-water slurry and diesel fuel, respectively

Comparing the demonstration of freedom from Trichinella infection of domestic pigs by traditional and risk-based surveillance

Traditionally, the routine artificial digestion test is applied to assess the presence of Trichinella larvae in pigs. However, this diagnostic method has a low sensitivity compared to serological tests. The results from artificial digestion tests in Switzerland were evaluated over a time period of 15 years to determine by when freedom from infection based on these data could be confirmed. Freedom was defined as a 95% probability that the prevalence of infection was below 0·0001%. Freedom was demonstrated after 12 years at the latest. A new risk-based surveillance approach was then developed based on serology. Risk-based surveillance was also assessed over 15 years, starting in 2010. It was shown that by using this design, the sample size could be reduced by at least a factor of 4 when compared with the traditional testing regimen, without lowering the level of confidence in the Trichinella-free status of the pig populatio

Micronized-coal-water slurry sprays from a diesel engine positive displacement fuel injection system

Experiments have been conducted to characterize the sprays from a modified positive displacement fuel injection system for a diesel engine. Diesel fuel water and three concentrations of micronized-coal-water slurry were used in these experiments. The injection system includes an injection jerk pump driven by an electric motor, a specially designed diaphragm to separate the abrasive coal slurry fuel from the pump, and a single-hole fuel nozzle. The sprays were injected into a pressurized chamber equipped with windows. High speed movies and still photographs of the sprays were obtained. In addition, instaneous fuel line pressures and needle lifts were obtained. Data were acquired as a function of fluid, nozzle orifice diameter, rack setting and chamber conditions. The high speed movies were used to determine spray penetration and spray growth

SBC2007-176715 OPTO-ELECTRIC BIOSENSOR TO EXAMINE IN VITRO TOXICITY STIMULI TO ENDOTHELIAL CELL MOTILITY AND MORPHOLOGY

ABSTRACT An integrated opto-electric biosensor is developed that uses an optically transparent and electrically conductive indium tin oxide (ITO) thin film coated on a slide glass substrate. This biosensor can simultaneously acquire the micro-impedance response and microscopic images of live cells in vitro under various toxic agent stimuli. The dynamic response of live porcine pulmonary artery endothelial cells (PPAECs) exposed to various doses of cytochalasin D are comprehensively examined by monitoring the micro-impedance characteristics at a specified frequency and DICM images using the opto-electric biosensor. The change in PPAEC morphology and motility caused by cytochalasin D clearly illustrates the dosedependent actin filament disruption where optical images are correlated with the changes in the micro-electric impedance. INTRODUCTION Micro-impedance sensing has a great deal of potential in quantifying cell physiology by monitoring cells cultured on small gold electrodes [1] Micro-impedance measurements however, are a sensitive and complex function of both cell-cell and cell-substrate interactions. Cellsubstrate interactions, for example, are mediated by integrin receptors that are functionally linked to the actin cytoskeleton. Biophysical cellsubstrate measurements have, therefore, been correlated with widely accepted biochemically established assays for cytotoxicity [2]. Although micro-impedance measurements have proven to be a valuable tool in examining the response of a large group of cells to various dose of cytochalasin D [3], this technique alone cannot completely evaluate inter cellular interactions. In order to properly examine cell-cell, and cell-substrate adhesion, visual techniques are required. Differential interference contrast microscopy (DICM) provides an excellent method for examining these interactions. Both electrically conductive and optically transparent ITO bioelectrodes [4] are combined with an integrated dynamic live cell imaging system. This system can therefore acquire optical and electrical measurements simultaneously, allowing the observation of cytochalasin D effects on live endothelial cells. Of specific interest is the morphological changes caused by the disruption of actin filaments in the cytoskeleton. This biosensor is able to electrically and optically monitor the real-time and label free drug effect on PPEACs with high temporal and spatial resolutions. The actual effect of three actin-affecting drugs (Cytochalasin D, Latrunculin A, and Jasplakinolide) on cell motility has been quantitatively investigated using video-microscopy of cancer cells [5]. The complicated phenomena of cell-substrate interactions and/or cellcell interaction also represent attractive indicators for studying cell signaling and tumor cell inhibition. In tumor cells, for example, it is a major challenge to inhibit the spreading from primary tumor sites to particular organs, which most likely create metastases killing approximately 90% of cancer patients. The present paper presents a new study of morphology and motility of PPAECs caused by cytochalasin D, which inhibits actin polymerization, by using opto-electric biosensors allowing simultaneous dynamic optical and electrical measurements. EXPERIMENT A. Microscopy DICM Senso

FlashCam: A fully digital camera for CTA telescopes

The future Cherenkov Telescope Array (CTA) will consist of several tens of telescopes of different mirror sizes. CTA will provide next generation sensitivity to very high energy photons from few tens of GeV to >100 TeV. Several focal plane instrumentation options are currently being evaluated inside the CTA consortium. In this paper, the current status of the FlashCam prototyping project is described. FlashCam is based on a fully digital camera readout concept and features a clean separation between photon detector plane and signal digitization/triggering electronics.Comment: In Proceedings of the 2012 Heidelberg Symposium on High Energy Gamma-Ray Astronomy. All CTA contributions at arXiv:1211.184

Performance Verification of the FlashCam Prototype Camera for the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) is a future gamma-ray observatory that is planned to significantly improve upon the sensitivity and precision of the current generation of Cherenkov telescopes. The observatory will consist of several dozens of telescopes with different sizes and equipped with different types of cameras. Of these, the FlashCam camera system is the first to implement a fully digital signal processing chain which allows for a traceable, configurable trigger scheme and flexible signal reconstruction. As of autumn 2016, a prototype FlashCam camera for the medium-sized telescopes of CTA nears completion. First results of the ongoing system tests demonstrate that the signal chain and the readout system surpass CTA requirements. The stability of the system is shown using long-term temperature cycling.Comment: 5 pages, 13 figures, Proceedings of the 9th International Workshop on Ring Imaging Cherenkov Detectors (RICH 2016), Lake Bled, Sloveni

FlashCam: a fully-digital camera for the medium-sized telescopes of the Cherenkov Telescope Array

The FlashCam group is currently preparing photomultiplier-tube based cameras proposed for the medium-sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The cameras are designed around the FlashCam readout concept which is the first fully-digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for the front-end electronics modules and a high performance camera server as back-end. This contribution describes the progress of the full-scale FlashCam camera prototype currently under construction, as well as performance results also obtained with earlier demonstrator setups. Plans towards the production and implementation of FlashCams on site are also briefly presented.Comment: 8 pages, 6 figures. In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589