The Marshall Lambert Symposium Contributions and Road Log

Road log of the Upper Cretaceous and lower Tertiary geology and paleontology of extreme southwestern North Dakota. Field trip sponsored by the Pioneer Trails Museum, June 19–20, 1993, Bowman, North Dakota. Published by the North Dakota Geological Society

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

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

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

Changes in Blood Cell Deformability in Chorea-Acanthocytosis and Effects of Treatment With Dasatinib or Lithium

Misshaped red blood cells (RBCs), characterized by thorn-like protrusions known as acanthocytes, are a key diagnostic feature in Chorea-Acanthocytosis (ChAc), a rare neurodegenerative disorder. The altered RBC morphology likely influences their biomechanical properties which are crucial for the cells to pass the microvasculature. Here, we investigated blood cell deformability of five ChAc patients compared to healthy controls during up to 1-year individual off-label treatment with the tyrosine kinase inhibitor dasatinib or several weeks with lithium. Measurements with two microfluidic techniques allowed us to assess RBC deformability under different shear stresses. Furthermore, we characterized leukocyte stiffness at high shear stresses. The results showed that blood cell deformability–including both RBCs and leukocytes - in general was altered in ChAc patients compared to healthy donors. Therefore, this study shows for the first time an impairment of leukocyte properties in ChAc. During treatment with dasatinib or lithium, we observed alterations in RBC deformability and a stiffness increase for leukocytes. The hematological phenotype of ChAc patients hinted at a reorganization of the cytoskeleton in blood cells which partly explains the altered mechanical properties observed here. These findings highlight the need for a systematic assessment of the contribution of impaired blood cell mechanics to the clinical manifestation of ChAc

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

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

Progress in Monte Carlo design and optimization of the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) will be an instrument covering a wide energy range in very-high-energy (VHE) gamma rays. CTA will include several types of telescopes, in order to optimize the performance over the whole energy range. Both large-scale Monte Carlo (MC) simulations of CTA super-sets (including many different possible CTA layouts as sub-sets) and smaller-scale simulations dedicated to individual aspects were carried out and are on-going. We summarize results of the prior round of large-scale simulations, show where the design has now evolved beyond the conservative assumptions of the prior round and present first results from the on-going new round of MC simulations.Comment: 4 pages, 5 figures. In Proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223