789 research outputs found
Classic and mirabolic Robinson-Schensted-Knuth correspondence for partial flags
In this paper we first generalize to the case of partial flags a result
proved both by Spaltenstein and by Steinberg that relates the relative position
of two complete flags and the irreducible components of the flag variety in
which they lie, using the Robinson-Schensted-Knuth correspondence. Then we use
this result to generalize the mirabolic Robinson-Schensted-Knuth correspondence
defined by Travkin, to the case of two partial flags and a line.Comment: 27 pages, slightly rewritten to combine two papers into one and
clarify some section
3D printing-assisted interphase engineering of polymer composites: Concept and feasibility
We introduced a general concept to create smart, (multi)functional interphases in polymer composites with layered reinforcements, making use of 3D printing. The concept can be adapted for both thermoplastic and thermoset matrix-based composites with either thermoplastic- or thermoset-enriched interphases. We showed feasibility using an example of a composite containing a thermoset matrix/thermoplastic interphase. Carbon fiber unidirectional reinforcing layers were patterned with poly(ε-caprolactone) (PCL) through 3D printing, then infiltrated with an amine-cured epoxy (EP). The corresponding composites were subjected to static and dynamic flexure tests. The PCL-rich interphase markedly improved the ductility in static tests without deteriorating the flexural properties. Its effect was marginal in Charpy impact tests, which can be explained with effects of specimen and PCL pattern sizes. The PCL-rich interphase ensured self-healing when triggered by heat treatment above the melting temperature of PCL
Timed-Elastic Bands for Manipulation Motion Planning
© 2019 IEEE. Motion planning is one of the main problems studied in the field of robotics. However, it is still challenging for the state-of-the-art methods to handle multiple conditions that allow better paths to be found. For example, considering joint limits, path smoothness and a mixture of Cartesian and joint-space constraints at the same time pose a significant challenge for many of them. This letter proposes to use timed-elastic bands for representing the manipulation motion planning problem, allowing to apply continuously optimized constraints to the problem during the search for a solution. Due to the nature of our method, it is highly extensible with new constraints or optimization objectives. The proposed approach is compared against state-of-the-art methods in various manipulation scenarios. The results show that it is more consistent and less variant, while performing in a comparable manner to that of the state of the art. This behavior allows the proposed method to set a lower-bound performance guarantee for other methods to build upon
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DETERMINATION AND COMPENSATION OF THE SHRINKAGE BEHAVIOR OF CYLINDRICAL ELEMENTS IN THE FDM PROCESS
Fused Deposition Modeling (FDM) is an additive manufacturing process to produce
complex thermoplastic geometries layer by layer. The filament is melted in a nozzle, iteratively
deposited, and then cools down. Due to the solidification process, the deposited filament strands
deviate from their intended position due to shrinkage, resulting in significant geometric deviations
in the final part. In terms of dimensional accuracy, there is a need for optimization, especially for
local curved geometries in relation to the global part with higher nominal dimensions. The aim of
this study is to investigate the size and shape deviations for cylindrical FDM elements and to
compensate the expected deformations by using an in-house software with adaptive scaling factors
in the x-y plane. Previous studies mainly focus on simple, non-curved objects, this study also
considers the influence of curvature and global as well as local deviations on the final part.Mechanical Engineerin
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Phase II prospective randomized trial of weight loss prior to radical prostatectomy.
BACKGROUND:Obesity is associated with poorly differentiated and advanced prostate cancer and increased mortality. In preclinical models, caloric restriction delays prostate cancer progression and prolongs survival. We sought to determine if weight loss (WL) in men with prostate cancer prior to radical prostatectomy affects tumor apoptosis and proliferation, and if WL effects other metabolic biomarkers. METHODS:In this Phase II prospective trial, overweight and obese men scheduled for radical prostatectomy were randomized to a 5-8 week WL program consisting of standard structured energy-restricted meal plans (1200-1500 Kcal/day) and physical activity or to a control group. The primary endpoint was apoptotic index in the radical prostatectomy malignant epithelium. Secondary endpoints were proliferation (Ki67) in the radical prostatectomy tissue, body weight, body mass index (BMI), waist to hip ratio, body composition, and serum PSA, insulin, triglyceride, cholesterol, testosterone, estradiol, leptin, adiponectin, interleukin 6, interleukin 8, insulin-like growth factor 1, and IGF binding protein 1. RESULTS:In total 23 patients were randomized to the WL intervention and 21 patients to the control group. Subjects in the intervention group had significantly more weight loss (WL:-3.7 ± 0.5 kg; Control:-1.6 ± 0.5 kg; p = 0.007) than the control group and total fat mass was significantly reduced (WL:-2.1 ± 0.4; Control: 0.1 ± 0.3; p = 0.015). There was no significant difference in apoptotic or proliferation index between the groups. Among the other biomarkers, triglyceride, and insulin levels were significantly decreased in the WL compared with the control group. CONCLUSIONS:In summary, this short-term WL program prior to radical prostatectomy resulted in significantly more WL in the intervention vs. the control group and was accompanied by significant reductions in body fat mass, circulating triglycerides, and insulin. However, no significant changes were observed in malignant epithelium apoptosis or proliferation. Future studies should consider a longer term or more intensive weight loss intervention
Preliminary Thesis on the First and Second Part of the ALLEGRO CFD Benchmark Exercise
At BME (Budapest University of Technology and Economics) NTI (Institute of
Nuclear Technics), a 7 pin rod bundle test section has been built in order to
investigate the hydraulic behavior of the coolant in such design and to develop
CFD models that could properly simulate the flow conditions in the ALLEGRO
core. PIROUETTE (PIv ROd bUndlE Test faciliTy at bmE) is a test facility, which
was designed to investigate the emerging flow conditions in various nuclear
fuel assembly rod bundles. The measurement method is based on Particle Image
Velocimetry (PIV) with Matching of Index of Refractory (MIR) method. In the
test loop, it was necessary to install a flow straightener that was able to
condition the velocity field before the rod bundle. The results of CFD
simulations could be used to improve the understanding of the inlet conditions
in the rod bundle test section.The second part of the benchmark deals with the
3D CFD modeling of the velocity field within the 7 pin rod bundle placed in the
test section. The geometry of the test section will be given to the
participants in an easy-to-use 3D format (.obj, .stp or .stl).Comment: 25 pages, 14 Figure, 6 Tables, Ancillary files are online availabl
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Homoepitaxial Growth of Single Crystal Diamond Membranes for Quantum Information Processing
Fabrication of devices designed to fully harness the unique properties of quantum mechanics through their coupling to quantum bits (qubits) is a prominent goal in the field of quantum information processing (QIP). Among various qubit candidates, nitrogen vacancy (NV) centers in diamond have recently emerged as an outstanding platform for room temperature QIP. However, formidable challenges still remain in processing diamond and in the fabrication of thin diamond membranes, which are necessary for planar photonic device engineering. Here we demonstrate epitaxial growth of single crystal diamond membranes using a conventional microwave chemical vapor deposition (CVD) technique. The grown membranes, only a few hundred nanometers thick, show bright luminescence, excellent Raman signature and good NV center electronic spin coherence times. Microdisk cavities fabricated from these membranes exhibit quality factors of up to 3000, overlapping with NV center emission. Our methodology offers a scalable approach for diamond device fabrication for photonics, spintronics, optomechanics and sensing applications.Engineering and Applied Science
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