34 research outputs found

    Non-Meckel Small Intestine Diverticulitis

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    Investigation of Spiral and Sweeping Holes

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    Surface infrared thermography, hotwire anemometry, and thermocouple surveys were performed on two new film cooling hole geometries: spiral/rifled holes and fluidic sweeping holes. The spiral holes attempt to induce large-scale vorticity to the film cooling jet as it exits the hole to prevent the formation of the kidney shaped vortices commonly associated with film cooling jets. The fluidic sweeping hole uses a passive in-hole geometry to induce jet sweeping at frequencies that scale with blowing ratios. The spiral hole performance is compared to that of round holes with and without compound angles. The fluidic hole is of the diffusion class of holes and is therefore compared to a 777 hole and Square holes. A patent-pending spiral hole design showed the highest potential of the non-diffusion type hole configurations. Velocity contours and flow temperature were acquired at discreet cross-sections of the downstream flow field. The passive fluidic sweeping hole shows the most uniform cooling distribution but suffers from low span-averaged effectiveness levels due to enhanced mixing. The data was taken at a Reynolds number of 11,000 based on hole diameter and freestream velocity. Infrared thermography was taken for blowing rations of 1.0, 1.5, 2.0, and 2.5 at a density ration of 1.05. The flow inside the fluidic sweeping hole was studied using 3D unsteady RANS

    Fluidic Actuation for Aeropropulsive Acoustic Improvements

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    Experiments were performed in NASAs SW-2 cascade facility to compare three trailing edge actuation concepts to a 3D airfoil section with no trailing edge treatment. At a Reynolds number of 105, trailing edge pulsed ejection using fluidic oscillator devices was shown to fill the momentum deficit in the wake more uniformly than other actuators tested, with expected benefits for tonal noise in engine fans. Furthermore, pulsed ejection was found to alter the acoustic signature of the wake to reduce broadband noise. In some locations in the wake, spectral components of velocity were found to be reduced by 2 to 5 dB across nearly all frequencies. Trailing edge pulsed ejection is established as a feasible concept to reduce both tonal and broadband noise emissions from aircraft engines

    PET/CT imaging in the diagnosis, staging, and follow-up of colorectal cancer

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    Colorectal cancer is a common malignancy that afflicts many in the western world. Imaging studies are frequently used to evaluate patients in the screening, staging and surveillance of colorectal cancer. Cross sectional imaging studies such as ultrasound, computed tomography and magnetic resonance imaging provide anatomic and morphologic information about tumor and patterns of spread. Positron emission tomography (PET) differs in that it provides information about tumor metabolism.[18F]Fluorodeoxyglucose PET has been clinically used for the evaluation of patients with a wide variety of cancers since most malignancies, including colorectal cancer, typically show increased glucose metabolism. This review present the positron emission tomography/computed tomography imaging findings that may be encountered in the diagnosis, staging and follow-up of patients with colorectal cancer

    Non-Meckel Small Intestine Diverticulitis

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    Non-Meckel small intestine diverticulitis can have many manifestations and its management is not well-defined. We report 4 unselect cases of small intestine diverticulitis; all patients were seen by the same physician at the Emergency Center at The University of Texas MD Anderson Cancer Center between 1999 and 2014. The median age at diagnosis of these patients was 82 years (range, 76–87 years). All 4 patients presented with acute onset of abdominal pain, and computed tomography scans showed characteristics of small intestine diverticulitis unrelated to cancer. Most of the diverticula were found in the region of the duodenum and jejuno-ileal segments of the small intestine. The patients, even those with peripancreatic inflammation and localized perforation, were treated conservatively. Non-Meckel diverticulitis can be overlooked in the initial diagnosis because of the location of the diverticulosis, the age of the patient, and the rarity of the disease. Because patients with non-Meckel small intestine diverticulitis can present with acute abdominal pain, non-Meckel small intestine diverticulitis should be considered in the differential diagnosis of patients with acute abdominal pain, and computed tomography scans can help identify the condition. Because of the rarity of non-Meckel small intestine diverticulitis, few studies have been published, and the data are inconclusive about how best to approach these patients. Our experience with these 4 elderly patients indicates that non-Meckel small intestine diverticulitis can be treated conservatively, which avoids the potential morbidity and mortality of a surgical approach
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