Fluid thrust control system

A pure fluid thrust control system is described for a pump-fed, regeneratively cooled liquid propellant rocket engine. A proportional fluid amplifier and a bistable fluid amplifier control overshoot in the starting of the engine and take it to a predetermined thrust. An ejector type pump is provided in the line between the liquid hydrogen rocket nozzle heat exchanger and the turbine driving the fuel pump to aid in bringing the fluid at this point back into the regular system when it is not bypassed. The thrust control system is intended to function in environments too severe for mechanical controls

Fibrational induction meets effects

This paper provides several induction rules that can be used to prove properties of effectful data types. Our results are semantic in nature and build upon Hermida and Jacobs’ fibrational formulation of induction for polynomial data types and its extension to all inductive data types by Ghani, Johann, and Fumex. An effectful data type μ(TF) is built from a functor F that describes data, and a monad T that computes effects. Our main contribution is to derive induction rules that are generic over all functors F and monads T such that μ(TF) exists. Along the way, we also derive a principle of definition by structural recursion for effectful data types that is similarly generic. Our induction rule is also generic over the kinds of properties to be proved: like the work on which we build, we work in a general fibrational setting and so can accommodate very general notions of properties, rather than just those of particular syntactic forms. We give examples exploiting the generality of our results, and show how our results specialize to those in the literature, particularly those of Filinski and Støvring

Transplantation of progenitor cells and regeneration enhancement in acute myocardial infarction - (TOPCARE-AMI)

Background - Experimental studies suggest that transplantation of blood-derived or bone marrow–derived progenitor cells beneficially affects postinfarction remodeling. The safety and feasibility of autologous progenitor cell transplantation in patients with ischemic heart disease is unknown

Deterministic Partial Differential Equation Model for Dose Calculation in Electron Radiotherapy

Treatment with high energy ionizing radiation is one of the main methods in modern cancer therapy that is in clinical use. During the last decades, two main approaches to dose calculation were used, Monte Carlo simulations and semi-empirical models based on Fermi-Eyges theory. A third way to dose calculation has only recently attracted attention in the medical physics community. This approach is based on the deterministic kinetic equations of radiative transfer. Starting from these, we derive a macroscopic partial differential equation model for electron transport in tissue. This model involves an angular closure in the phase space. It is exact for the free-streaming and the isotropic regime. We solve it numerically by a newly developed HLLC scheme based on [BerCharDub], that exactly preserves key properties of the analytical solution on the discrete level. Several numerical results for test cases from the medical physics literature are presented.Comment: 20 pages, 7 figure

Eigenvector statistics in non-Hermitian random matrix ensembles

We study statistical properties of the eigenvectors of non-Hermitian random matrices, concentrating on Ginibre's complex Gaussian ensemble, in which the real and imaginary parts of each element of an N x N matrix, J, are independent random variables. Calculating ensemble averages based on the quantity $< L_\alpha | L_\beta >$, where $< L_\alpha |$ and $| R_\beta >$ are left and right eigenvectors of J, we show for large N that eigenvectors associated with a pair of eigenvalues are highly correlated if the two eigenvalues lie close in the complex plane. We examine consequences of these correlations that are likely to be important in physical applications.Comment: 4 pages, no figure

Incidence and Causes of Hospital Readmission in Pediatric Patients after Hematopoietic Cell Transplantation

AbstractAllogeneic (allo) and autologous (auto) hematopoietic cell transplantation (HCT) provide the potential to cure otherwise fatal diseases but they are resource-intense therapies. There is scant literature describing the burden of hospital readmission in the critical 6-month period of immunosuppression after HCT. We report the incidence, causes, and outcomes of readmission in the 6 months after day 0 of HCT and in the 30 days after hospital discharge. This study is an institutional review board–approved retrospective medical record review of children who underwent HCT at a single institution. Between January 1, 2008 and December 31, 2011, 291 children underwent HCT at our institute. Of these, 140 patients were excluded because they were not followed primarily at our institute for the first 6 months after transplantation, 14 patients were excluded because they died during their initial hospitalization, and 1 patient was excluded because the initial hospitalization was longer than 6 months. Of the remaining 136 patients, 63% had at least 1 readmission. Of the patients who underwent allo-HCT, 78% were readmitted, in contrast to 38% of auto-HCT patients (P < .001). For the 206 readmissions, the mean length of hospital stay was 10.7 days (range, 1 to 129). Seventy-two percent of auto-HCT patients were initially readmitted for fever, and 46% ultimately had a source identified. No risk factors for readmission were found in the auto-HCT group. Fifty-two percent of allo-HCT patients were readmitted for fever and 28% of these patients ultimately had an identified source. Gastrointestinal-related problems accounted for 30% of primary readmissions among allo-HCT patients. Patients with an unrelated donor had a trend towards increased rates of 30-day readmission (P = .06) and were more likely to have a second readmission (P = .002). Patients who were cytomegalovirus (CMV) positive before transplantation were more likely to be readmitted (P = .02). The majority of children who undergo HCT are readmitted during the critical 180 days after transplantation. Readmission is much more common among allo-HCT patients, in particular those with unrelated donors and CMV-positive serologies before transplantation. Fever is the most common cause of readmission in these patients, and serious infections are identified in a significant portion of patients. These findings and future research in this area will help improve both patient education and resource utilization

Almost-Hermitian Random Matrices: Crossover from Wigner-Dyson to Ginibre eigenvalue statistics

By using the method of orthogonal polynomials we analyze the statistical properties of complex eigenvalues of random matrices describing a crossover from Hermitian matrices characterized by the Wigner- Dyson statistics of real eigenvalues to strongly non-Hermitian ones whose complex eigenvalues were studied by Ginibre. Two-point statistical measures (as e.g. spectral form factor, number variance and small distance behavior of the nearest neighbor distance distribution $p(s)$) are studied in more detail. In particular, we found that the latter function may exhibit unusual behavior $p(s)\propto s^{5/2}$ for some parameter values.Comment: 4 pages, RevTE

Starlight Demonstration of the Dragonfly Instrument: an Integrated Photonic Pupil Remapping Interferometer for High Contrast Imaging

In the two decades since the first extra-solar planet was discovered, the detection and characterization of extra-solar planets has become one of the key endeavors in all of modern science. Recently direct detection techniques such as interferometry or coronography have received growing attention because they reveal the population of exoplanets inaccessible to Doppler or transit techniques, and moreover they allow the faint signal from the planet itself to be investigated. Next-generation stellar interferometers are increasingly incorporating photonic technologies due to the increase in fidelity of the data generated. Here, we report the design, construction and commissioning of a new high contrast imager; the integrated pupil-remapping interferometer; an instrument we expect will find application in the detection of young faint companions in the nearest star-forming regions. The laboratory characterisation of the instrument demonstrated high visibility fringes on all interferometer baselines in addition to stable closure phase signals. We also report the first successful on-sky experiments with the prototype instrument at the 3.9-m Anglo-Australian Telescope. Performance metrics recovered were consistent with ideal device behaviour after accounting for expected levels of decoherence and signal loss from the uncompensated seeing. The prospect of complete Fourier-coverage coupled with the current performance metrics means that this photonically-enhanced instrument is well positioned to contribute to the science of high contrast companions.Comment: 10 pages, 7 figures, accepted to Mon. Not. of Roy. Ast. Soc., 201