1,427 research outputs found

    Computational analysis of hypersonic airbreathing aircraft flow fields

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    The general problem of calculating the flow fields associated with hypersonic airbreathing aircraft is presented. Unique aspects of hypersonic aircraft aerodynamics are introduced and their demands on computational fluid dynamics are outlined. Example calculations associated with inlet/forebody integration and hypersonic nozzle design are presented to illustrate the nature of the problems considered

    Computation of laminar viscous-inviscid interactions in high-speed internal flows

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    A review is given of computations for a series of nominally 2-D laminar viscous-inviscid interactions. Comparisons were made with detailed experimental shock tunnel results. The shock wave boundary layer interactions considered were induced by a compression ramp in one case and by an externally generated incident shock in the second case. In general, good agreement was reached between the grid refined calculations and experiment for the incipient and small separation conditions. For the highly separated flow, 3-D calculations which included the finite span effects of the experiment were required in order to obtain agreement with the data

    Rotor wake transport in turbomachine stators

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    February 1971Includes bibliographical references (leaf 12)The mechanism of rotor wake interaction with stators has been examined experimentally by using helium, injected into the rotor wakes, as a tracer for the wake fluid. Time averaged helium Drofiles downstream of the stator, measured with a thermal conductivity cell, indicate the time averaged distribution of rotor wake fluid at the stator exit. The results are in qualitative agreement with the wake transport theory of Kerrebrock and Mikolajczak, but indicate the need for accounting for differential radial drifts of the wake fluid which encounters the motion and pressure sides of the stator blades. They also indicate that the wake transport theory is valid only when the stators flow is not separated.This Research Carried Out in the Gas Turbine Laboratory, M.I.T., Supported in Part by Pratt & Whitney Aircraft, Division of United Aircraft Corporation, and in Part by the General Electric Compan

    A text Ontology Method based on mining Develop D –MATRIX

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    In this issue, we demonstrate a text mining method of ontology based on the development and updating of a D-matrix naturally extraction of a large number of verbatim repairs (written in unstructured text) collected during the analysis stages. dependence (D) Fault - Matrix is a systematic demonstrative model is used to capture data symptomatic level progressive elimination system including dependencies between observable symptoms and failure modes associated with a frame. Matrix is a time D-long process. The development of D-matrix from first standards and update using the domain information is a concentrated work. In addition, increased D-die time for the disclosure of new symptoms and failure modes observed for the first race is a difficult task. In this methodology, we first develop the fault diagnosis ontology includes concepts and relationships regularly seen in fault diagnosis field. Then we use text mining algorithm that make use of this ontology to distinguish basic items, such as coins, symptoms, failure modes, and conditions of the unstructured text verbatim repair. The proposed technique is tools like a prototype tool and accepted using real - life information collected from cars space

    Cullin 3–Mediated Regulation of Intracellular Iron Homeostasis Promotes Thymic Invariant NKT Cell Maturation

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    The E3 ubiquitin ligase cullin 3 (Cul3) is critical for invariant NKT (iNKT) cell development, as iNKT cells lacking Cul3 accumulate in the immature developmental stages. However, the mechanisms by which Cul3 mediates iNKT cell development remain unknown. In this study, we investigated the role of Cul3 in both immature and mature thymic iNKT cells using a mouse model with a T cell–specific deletion of Cul3. We found that mature iNKT cells lacking Cul3 proliferated and died more than wild-type cells did. These cells also displayed increased glucose metabolism and autophagy. Interestingly, we found that tight regulation of iron homeostasis is critical for iNKT cell development. Without Cul3, mature iNKT cells harbored higher levels of cytosolic iron, a phenotype associated with increased cell death. Taken together, our data suggest that Cul3 promotes iNKT cell development partially through intracellular iron homeostasis. ImmunoHorizons, 2023, 7: 235–242

    Role of closed subcutaneous drain in prevention of surgical site infection in perforation peritonitis

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    Background: Surgery for perforation peritonitis is associated with the highest rates of infective complications, especially surgical site infection. SSI occurs due to failure of obliteration of dead space during abdominal wound closure resulting in formation of hematoma and seroma collection in the surgical wound viz. abdominal wound in cases of perforation peritonitis. This acts as a good culture medium for bacterial organisms to grow and cause wound infection. The bacterial pathogens can be either from intra-abdominal sepsis or nosocomial in origin. Closed suction drains can be used effectively to eliminate dead space in the wound and evacuates the seroma or hematoma collection, thereby reducing chances of SSI and also helps in early detection of SSI by inspecting the nature of drain output. Aim was to evaluate the role of closed suction drains in prevention of SSI in cases of perforation peritonitis. Methods: Comparative study of 60 cases of perforation peritonitis divided into two equal groups (Group A patient with closed suction drain in subcutaneous space vs. Group B patient without closed suction drain). Outcomes of SSI were compared. Results: The incidence of SSI in Group A was 33% whereas in Group B was 70%. 40% cases in SSI in Group A whereas 76% cases of SSI in Group B developed wound dehiscence. Most cases of SSI was diagnosed on POD 2 for Group A and on POD 4 for Group B. Conclusions: The study supports use of closed suction drain in perforation peritonitis for prevention, early detection and appropriate management of SSI

    Thermal Degradation Kinetics of Distillers Grains and Solubles in Nitrogen and Air

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    The pyrolysis and oxidation kinetics of distillers grains and solubles were determined using thermogravimetric analysis. The starting temperature of pyrolysis and oxidation of distillers grains and solubles increased with the increase of heating rate and initial moisture content. The pyrolysis and oxidation of distillers grains and solubles were completed at 650°C and 850°C, respectively, which were independent of the heating rate and the initial moisture content. The residual weights of distillers grains and solubles after pyrolysis and oxidation were 27.15% and 5.49% of the original dry mass of distillers grains and solubles. Thermogravimetrical analysis data was used to determine kinetic parameters of the thermal degradation of distillers grains and solubles. Predicted dynamic residual weights of distillers grains and solubles during thermal degradation agreed well with experimental data. Keywords: biomass, distillers grains and solubles, kinetics, TGA, thermochemica
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