A Reduced-Order Model Bi-Modal Excitation of a Supersonic Planar Jet

This work analytically and numerically examines the effects of bi-modal excitation on a Mach 1.5 heated planar jet. Starting with the Navier-Stokes equations, triple decomposition is applied to the flow components. A reduced order model is derived, turning the Navier-Stokes partial differential equations into a set of coupled ordinary differential equations, relating the momentum thickness and amplitudes of a fundamental and subharmonic mode to the streamwise location along the jet. Computational fluid dynamics data from the minor plane of a Mach 1.5 heated rectangular jet is used to verify a hyperbolic tangent profile for the mean flow at various streamwise locations. Locallyparallel linear stability theory is used to compute the shape assumptions for the coherent structure components involved in the set of ordinary differential equations. The set of ordinary differential equations is first solved for a single mode. The trends for the single mode excitation qualitatively compared well with previous work. In the initial region, the nonlinear amplitude generally agreed well with the linear solution. Bi-modal excitation is then examined for the fundamental Strouhal number 0.10, which has been identified as a dominant noise source. Cases were considered separately with adding the subharmonic and the harmonic as a means of reducing the amplitude of the fundamental. Adding the subharmonic had minimal effects on reducing the fundamental unless both initial amplitudes are large. However, adding the harmonic could be very effective at reducing the fundamental even at low initial amplitudes. It is ultimately determined that adding the subharmonic may or may not be effective as a noise-reducing mechanism but adding the harmonic can be effective depending on the initial phase difference between the two excitations

Semi-PROPELLER Compressed Sensing Image Reconstruction with Enhanced Resolution in MRI

Magnetic Resonance Imaging (MRI) reconstruction algorithm using semi-PROPELLER compressed sensing is pre- sented in this paper. It is exhibited that introduced algorithm for estimating data shifts is feasible when super- resolution is applied. The offered approach utilizes compressively sensed MRI PROPELLER sequences and improves MR images spatial resolution in circumstances when highly undersampled k-space trajectories are applied. Compressed Sensing (CS) aims at signal and images reconstructing from significantly fewer measurements than were conventionally assumed necessary. Compressed sensing (CS) aims at signal and images reconstructing from significantly fewer measurements than were traditionally thought necessary. It is shown that the presented approach improves MR spatial resolution in cases when Compressed Sensing (CS) sequences are used. The application of CS in medical modalities has the potential for significant scan time reductions, with visible benefits for patients and health care economics. These methods emphasize on maximizing image sparsity on known sparse transform do- main and minimizing fidelity. This diagnostic modality struggles with an inherently slow data acquisition process. The use of CS to MRI leads to substantial scan time reductions and visible benefits for patients and economic factors. In this report the objective is to combine Super-Resolution image enhancement algorithm with both PROPELLER sequence and CS framework. All the techniques emphasize on maximizing image sparsity on known sparse transform domain and minimizing fidelity. The motion estimation algorithm being a part of super resolution reconstruction (SRR) estimates shifts for all blades jointly, emphasizing blade-pair correlations that are both strong and more robust to noise.

Natural radioactivity in rocks of the Modane-Aussois region (SE France)

The activity concentrations of 40K, 232Th, and 238U in the characteristic rocks of the Modane-Aussois region (Western Alps, France) were determined using an HPGe gamma-ray spectrometry system. The activity concentrations of 40K varied from 18 Bqkg-1 (limestone dolomite) to 392 Bqkg-1 (calcschist), while those of 232Th varied from 0.7 Bqkg-1 (limestone dolomite) to 18 Bqkg-1 (calcschist). The activities associated with 238U ranged from 9 (quartzite) to 29 Bqkg-1 (dolomite). In the investigated rock samples, concentrations of 238U (ppm) and 40K (%) had a strong negative correlation

The method of machinery and device assessment based on MAZTe-Mutilization.

Interdisciplinary relations of the issues concerning machinery and device utilization have gained significant importance in technical diagnostics in the aspect of their applications. Technical diagnostics as a discipline of the methods and techniques to examine the technical condition of structures, refers to the assessment of the reliability through monitoring functional performance of production and assisting processes and the features of the end product. The MAZTe-M method enables assessment of the value of the fixed assets within the area of machinery and devices on the basis of the technical environment of their operations (according to their technical condition, reliability, the amount of work performed and order priority) in two aspects: their wear in the specific working place in a company as well as economic profitability of utilization. The MAZTe- M method analyses the utilization of machinery and devices in a particular technical environment. In order to estimate the average value of a machine,one applies functions describing coefficient values against the passing of time. In the case ofeconomic wear of machinery and devices, calculating complementary synergy coefficientis calculated taking into account the process of machinery and devices liquidationunder the owner’s supervision

57Fe Mossbauer spectroscopy of radiation damaged allanites

Metamict minerals contain radioactive elements that degrade the crystal structure of the minerals. The degradation occurs primarily through progressive overlapping recoil nuclei collision cascades from ®-decays of 238U, 232Th, 235U and their daughter products. We report the results of 57Fe Mossbauer spectroscopy, gamma-ray spectrometry and microprobe analysis of three partially metamict allanites, (Ca,Ce,REE)2(Fe2+; Fe3+)(Al; Fe3+)2O[Si2O7][SiO4](OH) where REE stands for rare earth elements. The samples were collected in pegmatites from Reno, Nevada (USA), Franklin, New Jersey (USA) and Nya Bast- nas Field (Sweden). The absorbed ®-dose for these minerals was found to range from 5:8 £ 1014 ®-decay/mg for the allanite from Reno to 1:9 £ 1015 ®-decay/mg for the allanite from Franklin. The Mossbauer spectra show a decrease in the Fe2+ doublet intensity with increasing absorber ®-dose. We also observe an increase in the line widths of the Fe2+ and Fe3+ doublets with increasing absorbed ®-dose

Preliminary results of 57Fe Mössbauer spectroscopy of metamict samarskite after one-hour high temperature annealing in argon

This work was supported by National Science Centre, Poland, through grant no. PW-0415-003.The preliminary results of 57Fe Mössbauer spectroscopy and X-ray diffraction (XRD) of fully metamict samarskite dated at ~1500 Ma, which absorbed α-dose of 6.5 × 1017 α-decay mg-1, are reported after one-hour annealing at 673, 873, 1173 and 1373 K in argon atmosphere. Metamict minerals contain radioactive elements that degrade their crystal structures over geological time. All the Mössbauer spectra obtained can be fitted to two quadrupole doublets assigned to Fe2+ and Fe3+ in octahedral positions. The relative contribution of Fe2+ (Fe2+/Fe) reaches a minimum of 0.10 at 1173 K.NC

222Rn and 220Rn concentrations in soil gas of the Izera Massif (Sudetes, Poland) as a function of sampling depth

This research presents soil gas 222Rn and 220Rn concentrations measured at 17 locations in the Izera Massif of southwest Poland. The average 222Rn concentrations at sampling depths of 10, 40 and 80 cm were 8, 78 and 224 kBq m–3, respectively. The average 220Rn concentrations for the same depths (10, 40 and 80 cm) were 6, 10 and 13 kBq m–3, respectively. Profiles of the concentrations versus depth can be fitted by exponential, linear and polynomial functions for soils developed on fault zones, above uranium mineral deposits, and above faulted uranium deposits, respectively. Soils developed on bedrock without fault zones or uranium mineralisation exhibit concentrations that follow a power function with an exponent of p <1

Accuracy Evaluation of the Canadian OpenStreetMap Road Networks

Volunteered geographic information (VGI) has been applied in many fields such as participatory planning, humanitarian relief and crisis management. One of the reasons for popularity of VGI is its cost-effectiveness. However, the coverage and accuracy of VGI cannot be guaranteed. The issue of geospatial data quality in the OpenStreetMap (OSM) project has become a trending research topic because of the large size of the dataset and the multiple channels of data access. This paper provides details on a national study of the Canadian OSM street network data for the assessment ofcompleteness, positional accuracy, attribute accuracy, semantic accuracy and lineage. The findings of the map quality can potentially guide cartographic product selection for interested parties and offer a better understanding of future improvement of OSM quality. In addition, the study presents the complex processes behind OSM contributions possibly influenced by data import and remote mapping

57Fe Mossbauer spectroscopy of annealed metamict davidite

This paper reports preliminary results of 57Fe Mössbauer spectroscopy and X-ray diffraction (XRD) studies of metamict davidite samples (La,Ce,Ca,Th)(Y,U,Fe)(Ti,Fe,Mn)20(O,OH)38 after high temperature annealing in an argon atmosphere. The Mössbauer spectra show a gradual decrease of quadrupole splitting and line width values of an Fe3+ doublet with increasing annealing temperature. Rather unexpected feature of these spectra for an Fe2+ doublet is a considerable increase of the line width with progressive crystallinity and a simultaneous decrease of both quadrupole splitting and isomer shift values. Changes of the hyperfine parameters as a function of the annealing temperature appeared as sensitive indicators of the thermal recrystallization process of metamict davidite similar to metamict silicates

Gamma background measurements in the Gran Sasso National Laboratory

In situ gamma-ray measurements were taken at eight locations in the Gran Sasso National Laboratory (Italy). Count rates for gamma radiation within the energy range of 7–2,734 keV varied from 8 to 60 c s-1. The arithmetic mean was 49 c s-1 for measurements taken without a collimator. The average gamma flux inside the Lab was 0.25 c cm-2 s-1. The sedimentary rocks surrounding the Lab are characterized by low activity concentrations of uranium and thorium, equal to 1.7 and 1.4 Bq kg-1, respectively