[en] Experimental investigations have shown that the flow discharged from a centrifugal compressor or pump impeller into the diffuser is unsteady and contributes for additional losses in the diffuser. The partially parabolic method is used to calculate this flow in the diffuser and reveals the mechanism of smoothing the distorted flow downstream. Calculated results are compared with measurements and good agreement is found. (author)

[en] Total reaction cross sections have been measured for 50 and 65 MeV π/sup +- / on C, O, /sup 18/O, S, Ca, and Zr. The motivation for this experiment is to obtain cross sections to act as constraints in optical model fits to elastic scattering data. Measurements using the ''poor geometry'' transmission method were made for exceptionally small angles with the aim of improving the accuracy of the extrapolation to zero solid angle. At these small solid angles the muon cone from pion decay contributes significantly and its effects were explicitly included. The accuracies of the elastic correction are evaluated by using error matrix techniques and an additional systematic error is included

[en] Chem-UNIFAC model is applied to TBP/dodecane/water/UO₂(NO₃)₂ and TBP/dodecane/water/HNO₃ systems, following our previous studies on TBP/diluent (alkane, HCCl₃, CCl₄) and TBP/diluent/water/salting out agent (same diluents) systems. New Chem-UNIFAC parameters for TBP/water pair are calculated and an unique set of parameters is proposed to describe the TBP/dodecane/water/UO₂(NO₃)₂ system, for a wide range of TBP/diluent volume proportions (10%, 30%, 50%, 100%) and a wide range of uranyl nitrate aqueous concentration. Nitric acid and water extraction in TBP/dodecane/water/HNO₃ is also calculated and an improvement is found in the description of the corresponding isotherms. (authors)

[en] The protein content of meals of various seeds (rice, lupine, sorghum, pumpkin, linseed, water melon, tomato) collected from Egypt and the USA was determined by 14 MeV neutron activation analysis via sup(14)N(n,2n)sup(13)N reaction. Non-conventional sources like tea and coffee residues are also investigated. The concentrations of trace elements determined by the x-ray fluorescence technique show definite differences even for a given type of seed produced in different geographical regions. (author)

[en] Purpose: We describe a computerized method of determining target margins for beam aperture design in conformal radiotherapy plans. Materials and Methods: The method uses previously measured data from a population of patients to simulate setup error and organ motion in the patient currently being planned. Starting with a clinical target volume (CTV) and nontarget organs from the patient's planning CT scan, the simulation is repeated many times to produce a spatial probability distribution for each organ in the treatment machine coordinate system. This is used to determine a prescribed dose volume (PDV), defined as the volume to receive the prescribed dose, which encompasses the CTV while restricting the volume of nontarget organs within it, according to planner-specified values. The PDV is used to design beam apertures using a conventional margin for beam penumbra. Results: The method is applied to 6-field prostate conformal treatment plans, in which the PDV encloses the prostate and seminal vesicles while limiting the enclosed rectal wall volume. The effect of organ motion is assessed by applying the plans on subsequent CT scans of the same patients, calculating probabilities for tumor control (TCP) and normal tissue complication (NTCP), and comparing with plans designed from a physician-drawn planning target volume (PTV). Although prostate TCP and rectal wall NTCP are found to be similar in the two sets of plans, TCP for the seminal vesicles is significantly higher in the PDV-based plans. Conclusions: The method can improve the dose conformality of treatment plans by incorporating population-based measurements of treatment uncertainties and consideration of nontarget tissues in the design of nonuniform target margins

[en] Estimates of effective doses and organ doses for male and female crew members are made for solar particle event proton environments comparable to several of the most significant solar particle events, which occurred in the second half of the 19th century (1864, 1878, 1894, 1895, and 1896). The incident proton energy distributions for these solar particle events are assumed to be similar to that of the November 1960 event, one of the most energetic of the modern space era. The crew members are assumed to be located at the mean surface elevation on Mars, at the lowest elevation on Mars in the Hellas Impact Basin, and on the summit of Olympus Mons, the highest surface elevation on Mars. The crew members are assumed to be shielded by the overlying carbon dioxide atmosphere of Mars, and locally shielded by a space suit, a surface landing spacecraft, or a surface habitat. These estimates are compared with current NASA Permissible Exposure Limits. (author)

[en] Short communication

[en] Unstructured and semi-structured radiology reports represent an underutilized trove of information for machine learning (ML)-based clinical informatics applications, including abnormality tracking systems, research cohort identification, point-of-care summarization, semi-automated report writing, and as a source of weak data labels for training image processing systems. Clinical ML systems must be interpretable to ensure user trust. To create interpretable models applicable to all of these tasks, we can build general-purpose systems which extract all relevant human-level assertions or “facts” documented in reports; identifying these facts is an information extraction (IE) task. Previous IE work in radiology has focused on a limited set of information, and extracts isolated entities (i.e., single words such as “lesion” or “cyst”) rather than complete facts, which require the linking of multiple entities and modifiers. Here, we develop a prototype system to extract all useful information in abdominopelvic radiology reports (findings, recommendations, clinical history, procedures, imaging indications and limitations, etc.), in the form of complete, contextualized facts. We construct an information schema to capture the bulk of information in reports, develop real-time ML models to extract this information, and demonstrate the feasibility and performance of the system.

[en] The current-carrying capability of superconducting wires is degraded by stress. Therefore electromechanical properties are one of the key feedback parameters needed for progress in conductor applications. In this work, uniaxial tensile stresses and bending stresses were applied to Fe /MgB₂ wires at room temperature, followed by measurement of critical current using a transport method at 4.2 K. Basic mechanical properties were calculated from the measured stress-strain characteristics. The irreversible tensile strain at which the critical current density of MgB₂ wire starts to degrade was found to be 0.5%. In addition, the degradation of I_c with decreasing bending diameters was found to be very rapid for wires that were deformed after the heat treatment that forms the MgB₂ compound, while not much degradation of I_c was found for wires that were bent before being annealed. SEM observations confirmed that cracks could be healed by post-annealing

[en] The peculiar features of magnesium diboride make it suitable for many potential applications. In the last four years of investigation of MgB₂, the scientific community's research was mainly motivated by features such as low cost, compatibility with straightforward processing methods, relatively high critical temperature, and absence of weak links between grains. Other applications suggest the accentuation of other MgB₂ properties. In particular its very low mass density makes it attractive for space activities, where the cost per kilogram for orbiting is still a huge obstacle, e.g. the cost of transport to low Earth orbit can reach 15 k$ kg^-1. In order to promote the use of this compound for space activities, we tested titanium as a sheath material. Titanium is non-magnetic and its alloys are almost half the weight of steel but with yield stresses up to three times higher. We fabricated Ti-sheathed MgB₂ through the powder-in-tube process. These wires show similar results to those sheathed with Fe. At 4 K the critical current density J_c is well above 7 x 10⁵ A cm^-2. The interface between the superconducting intermetallic compound and the lightweight sheath does not show any evidence of reaction and diffusion up to 900 deg. C. An analysis was carried out using x-ray diffraction, scanning electron microscopy with an energy dispersive spectrometer, and electron microprobe analysis