Component Maps Research Articles

Run time Assessment for Gas Turbine Performance Simulation

This article describes the run time characteristics of a gas turbine performance simulation using different solvers and components off-design performance database formats. Two different nonlinear systems of equation solvers, Newton-Raphson’s and Broyden’s, and two different formats of compressor and turbine off-design performance database (maps),tabulated values and fi tted surface equations, were compared. Based on the results it is then possible to trade off and select the most appropriate combination of solver and component map type for the gas turbine performance simulation for real-time application.

A component map adaptation method for compressor modeling and diagnosis

The accuracy of model-based gas turbine performance prediction, diagnosis, and prognosis is mainly determined by the precision of compressor thermodynamic model. This article proposes a novel compo...

Au36(SePh)24 nanomolecules: synthesis, optical spectroscopy and theoretical analysis.

Here, we report the synthesis of selenophenol (HSePh) protected Au36(SePh)24 nanomolecules via a ligand-exchange reaction of 4-tert-butylbenzenethiol (HSPh-tBu) protected Au36(SPh-tBu)24 with selenophenol, and its spectroscopic and theoretical analysis. Matrix assisted laser desorption ionization (MALDI) mass spectrometry, electrospray ionization (ESI) mass spectrometry and optical characterization confirm that the composition of the as synthesized product is predominantly Au36(SePh)24 nanomolecules. Size exclusion chromatography (SEC) was employed to isolate the Au36(SePh)24 and temperature dependent optical absorption studies and theoretical analysis were performed. Theoretically, an Independent Component Maps of Oscillator Strength (ICM-OS) analysis of simulated spectra shows that the enhancement in absorption intensity in Au36(SePh)24 with respect to Au36(SPh)24 can be ascribed to the absence of interference and/or increased long-range coupling between interband metal core and ligand excitations. This work demonstrates and helps to understand the effect of Au-Se bridging on the properties of gold nanomolecules.

Development of Auto Soil Sample Machine for Constructing Chemical Component Map of Large Farm Field

Development of Auto Soil Sample Machine for Constructing Chemical Component Map of Large Farm Field

Flash floods potential area mapping at Huong Khe district, Ha Tinh prov

Ha Tinh is one of the provinces most affected by natural hazards, especially flash floods. Sloping hilly terrain conditions, reduced covering density of forest and unfavorable weather conditions are potential hazards to flash floods. Flash floods potential area mapping at Huong Khe district, Ha Tinh province was carried out using Remote Sensing and GIS technologies. Factors causing flash floods was indentified and classified basing n their afecting level. Component maps of flash flood–causing factors were overlayed. Factors causing flash floods as noted by Greg Smith included: slope, soil type, forms of using land, covering density of forest. Potential areas of flash floods and the potential level of each part were indentified. The resulted maps can be used for forecasting risk regions of flash floods at the district.

Halo Pressure Profile through the Skew Cross-power Spectrum of the Sunyaev–Zel’dovich Effect and CMB Lensing in Planck

Abstract We measure the cosmic microwave background (CMB) skewness power spectrum in Planck, using frequency maps of the HFI instrument and the Sunyaev–Zel’dovich (SZ) component map. The two-to-one skewness power spectrum measures the cross-correlation between CMB lensing and the thermal SZ effect. We also directly measure the same cross-correlation using the Planck CMB lensing map and the SZ map and compare it to the cross-correlation derived from the skewness power spectrum. We model fit the SZ power spectrum and CMB lensing–SZ cross-power spectrum via the skewness power spectrum to constrain the gas pressure profile of dark matter halos. The gas pressure profile is compared to existing measurements in the literature including a direct estimate based on the stacking of SZ clusters in Planck.

Irreducible Morphisms Between Modules over a Repetitive Algebras

We describe the irreducible morphisms in the category of modules over a repetitive algebra. We find three special canonical forms: The first canonical form happens when all the component morphisms are split monomorphisms, the second when all the component morphisms are split epimorphisms and the third when there is exactly one irreducible component map. Also, we obtain the same result for the irreducible homomorphisms in the stable category of modules over a repetitive algebra.

Facilitating in vivo tumor localization by principal component analysis based on dynamic fluorescence molecular imaging.

Fluorescence molecular imaging has been used to target tumors in mice with xenograft tumors. However, tumor imaging is largely distorted by the aggregation of fluorescent probes in the liver. A principal component analysis (PCA)-based strategy was applied on the in vivo dynamic fluorescence imaging results of three mice with xenograft tumors to facilitate tumor imaging, with the help of a tumor-specific fluorescent probe. Tumor-relevant features were extracted from the original images by PCA and represented by the principal component (PC) maps. The second principal component (PC2) map represented the tumor-related features, and the first principal component (PC1) map retained the original pharmacokinetic profiles, especially of the liver. The distribution patterns of the PC2 map of the tumor-bearing mice were in good agreement with the actual tumor location. The tumor-to-liver ratio and contrast-to-noise ratio were significantly higher on the PC2 map than on the original images, thus distinguishing the tumor from its nearby fluorescence noise of liver. The results suggest that the PC2 map could serve as a bioimaging marker to facilitate in vivo tumor localization, and dynamic fluorescence molecular imaging with PCA could be a valuable tool for future studies of in vivo tumor metabolism and progression.

Advances in Structural Characterization Using Soft X-ray Scanning Transmission Microscopy (STXM): Mapping and Measuring Porosity in PEM-FC Catalyst Layers

Access of fuel and oxidant gases to the active catalyst sites in dispersive electrodes of polymer electrolyte membrane fuel cells (PEM-FC) is an important characteristic defining the performance of the whole catalyst coated membrane unit (CCM). The electrode porosity – the ratio of empty space to the whole volume of the electrode – is a metric widely used to characterize the ability of a particular electrode to provide gas transport. It is common practice to present electrode porosity as a number averaged over a macroscopic volume of the electrode [1]. In compliment to already established methods, soft X-ray scanning transmission X-ray microscopy (STXM) offers the possibility to visualize the microscopic network of the pore space in the electrode with ~30 nm spatial resolution. Thus, in addition to average porosity, STXM provides porosity distributions in electrodes, with a local value averaged per voxel of ~1003 nm3. Relative to studies of the electrode porosity visualized by the focused ion beam – scanning electron microscopy method (FIB-SEM) [2], STXM provides direct visualization of the pore-space in the electrode without destroying the sample and omitting the 3D reconstruction process. Here we present STXM porosity distribution for 2D projection of the thin cathode lamella. STXM pore space visualization relies on filling the pores with a material that STXM can discriminate spectroscopically relative to the other components (carbon support, ionomer, and metal catalyst-Pt) [3]. In these experiments the cathode catalyst decals are embedded with a custom epoxy (TTE, the product of reacting trimethylolpropane triglycidyl ether and 4,4’-methylenebis(2-methylcyclohexylamine in 1:1 wt ratio, which results in a final chemical formula (C10H10N3)n and density of 1.0 g/cm3). While the TTE epoxy is fluid it wets well the electrode inner interfaces filling most of the available space. 100 nm thick microtomed sections of the cathode embedded in TTE are measured by STXM at the C 1s edge at the Canadian Light Source (Saskatoon) or the Advanced Light Source (Berkeley). The C1s stacks, consisting of images at 50-70 energies over 280-330 eV with 100 nm pixels, are converted to optical density, and then fit using standard, quantitative reference spectra (OD1 scale) of carbon-support (Cs), ionomer (I), TTE and Pt components to construct 2D component maps of each component. The grayscale value at each pixel is the nm thickness of that component. The total volume is the sum of Cs, I, TTE, and Pt values at each pixel. The 2D porosity map is then the ratio of the TTE map to the total-volume map, where each pixel has a unit of part per volume (ppvol). STXM performed using BL 10ID1 at CLS and BL 5.3.2.2 at ALS. Research supported by NSERC. S. Shukla, et.al., 231 ECS 2017, Abst 97034, https://ecs.confex.com/ecs/231/webprogram/Paper97034.htmlM.Sabharwal, et al., Fuel Cell, 16 (2016) No.6, 734–753H. Ade, et al., Polymers, 49 (2008) 643-675 Figure 1

A new component map generation method for gas turbine adaptation performance simulation

The accuracy of component maps significantly affects gas turbine performance simulation results. Unfortunately, the information in component maps is usually insufficient to performance simulation. In this paper, a new compressor map generation method is presented with the primary objective of improving the accuracy of the gas turbine performance simulation model under insufficient information. In this method, the compressor map is first generated as an initial map according to the operating points determined by a set of steady-state operating data, and the coefficients that determine the shape of the compressor map are analyzed and tuned through a multi-objective optimization scheme to match multiple sets of transient data. To verify the validity of the new method, an LM2500 compressor map from the public literature was generated and the results were compared with those of existing fitting methods. Furthermore, the new map generation method, developed in Simulink, was implemented in a dynamic gas turbine model and tested in off-design steady-state and transient conditions. The results showed that the method is able to overcome the shortcomings of the existing methods and to effectively improve the accuracy of the gas turbine performance model under insufficient information.

Socioeconomic Convergence in Europe One Decade After the EU Enlargement of 2004: Application of Self-Organizing Maps

This article uses self-organizing maps (SOMs) to examine convergence between European states, giving special attention to the states of Central and Eastern Europe (CEE) that joined the European Union (EU) during its monumental expansion in 2004. To augment the literature on income convergence, the robust conceptual framework employed here is based upon Terry Jordan’s much broader socioeconomic and political definition of Europe. Using associated variables, the study applies the Kohonen data visualization technique to highlight statistical clustering and movement of countries across three time periods from 2001 to 2013. Kohonen U-matrix and component maps reveal several distinct clusters of countries that remain stable over time, including Europe’s industrialized core and Scandinavia, as well as a cluster of laggard Soviet successor states at the opposite extreme. The eleven new EU countries that had been part of the eastern bloc show evidence of real (β-) convergence toward the European core, but at various paces. The Baltic states of Lithuania and Latvia experience some of the greatest observable convergence, followed by Estonia, the Visegrád states, and the former Yugoslav states of Croatia and Slovenia. Other countries that demonstrate considerable movement during the time period under investigation include some crisis-battered Mediterranean countries, plus Montenegro, Kosovo, and Turkey. While most of the evident statistical mobility is positive, Ireland experiences nominal and real divergence during the period 2011–13. In the context of Europe’s ongoing recession and the aftermath of the UK’s referendum, these findings have implications for two uncertainties: the very survival of the EU and its prospects for further expansion.

Simulation-based steady-state aero-thermal model for small-scale turboprop engine

PurposeAn aircraft engine control system consists of a large scale of control parameters and variables because of the complex structure of aero-engine. Monitoring and adjusting control variables and parameters such as detecting, isolating and reconfiguring the system faults/failures depend on the controller design. Developing a robust controller is based on an accurate mathematical model.Design/methodology/approachIn this study, a small-scale turboprop engine is modeled. Simulation is carried out on MATLAB/Simulink for design and off-design operating conditions. Both steady-state and transient conditions (from idle to maximum thrust levels) are tested. The performance parameters of compressor and turbine components are predicted via trained Neuro-Fuzzy model (ANFIS) based on component maps. Temperature, rotational speed, mass flow, pressure and other parameters are generated by using thermodynamic formulas and conservation laws. Considering these calculated values, error calculations are made and compared with the cycle data of the engine at the related simulation conditions.FindingsSimulation results show that the designed engine model’s simulation values have acceptable accuracy for both design and off-design conditions from idle to maximum power operating envelope considering cycle data. The designed engine model can be adapted to other types of gas turbine engines.Originality/valueDifferent from other literature studies, in this work, a small-scale turboprop engine is modeled. Furthermore, for performance prediction of compressor and turbine components, ANFIS structure is applied.

Knowledge-Driven Prospectivity Mapping for Granite-Related Polymetallic Sn–F–(REE) mineralization, Bushveld Igneous Complex, South Africa

This paper presents mineral prospectivity mapping to identify potential new exploration ground for polymetallic Sn–F–REE mineralization associated with the Bushveld granites of the Bushveld Igneous Complex, South Africa. The Lebowa Granite Suite, commonly known as the Bushveld granites, is host to a continuum of polymetallic mineralization with a wide range of metal assemblages (Sn–Mo–W–Cu–Pb–Zn–As–Au–Ag–Fe–F–U–REE), ranging from a high-temperature to a low-temperature magmatic hydrothermal mineralizing environment. The prospectivity map was generated by fuzzy logic modeling and a selection of targeting criteria (or spatial proxies) based on a conceptual mineral system highlighting critical processes responsible for the formation of the polymetallic mineralization. The spatial proxies include proximity to differentiated granites (as heat and metal-rich fluid sources), Rb geochemical map (fluid-focusing mechanism such as fractionation process), principal component maps (PC 4 Y–Th and PC 14 Sn–W, fluid pathways for both high- and low-temperature mineralization) and proximity to roof rocks (traps for fluids). Logarithmic functions were used to rescale rasterized evidential maps into continuous fuzzy membership scores in a range of [0, 1]. The evidential maps were combined in two-staged integration matrix using fuzzy AND, OR and gamma operators to produce the granite-related polymetallic Sn–F–(REE) prospectivity map. The conceptual mineral system model and corresponding prospectivity model developed in this study yielded an encouraging result by delineating the known mineral deposits and occurrences of Sn–F–(REE) mineralization that were not used to assign weights to the evidential maps. The prospectivity model predicted, on average, 77% of the known mineral occurrences in the BIC (i.e., 56 of 73 Sn occurrences, 12 of 15 F occurrences and 6 of 8 REE occurrences). Based on this validation, 13 new targets were outlined in this study.

Optical absorption of (Ag-Au)133(SCH3)52 bimetallic monolayer-protected clusters

The evolution of the optical absorption spectrum of bimetallic Ag-Au monolayer-protected clusters (MPC) obtained by progressively doping Ag into the experimentally known structure of Au133(SR)52 was predicted via rigorous time-dependent density-functional theory (TDDFT) calculations. In addition to monometallic Au133(SR)52 and Ag133(SR)52 species, 5 different (Ag-Au)133(SR)52 homotops were considered with varying Ag content and site positioning, and their electronic structure and optical response were analyzed in terms of Projected Density Of States (PDOS), the induced or transition electron density, and Transition Component Maps (TCM) at selected excitation energies. It was found that Ag doping led to the effects rather different from those encountered in bare metal clusters. And it was also observed that Ag doping could produce structured spectral features, especially in the 3–4eV range but also in the optical region if Ag atoms were located in the sub-staple region, as rationalized by the accompanying electronic analysis. Additionally, Au doping into the staples of Ag-rich MPC also gave rise to a more homogeneous induced electron density. These findings show the great sensitivity of the electronic response of MPC nanoalloy systems to the exact location of the alloying sites.

Planck2015 results

Planck has mapped the microwave sky in nine frequency bands between 30 and 857 GHz in temperature and seven bands between 30 and 353 GHz in polarization. In this paper we consider the problem of diffuse astrophysical component separation, and process these maps within a Bayesian framework to derive a consistent set of full-sky astrophysical component maps. For the temperature analysis, we combine the Planck observations with the 9-year WMAP sky maps and the Haslam et al. 408 MHz map to derive a joint model of CMB, synchrotron, free-free, spinning dust, CO, line emission in the 94 and 100 GHz channels, and thermal dust emission. Full-sky maps are provided with angular resolutions varying between 7.5 arcmin and 1 deg. Global parameters (monopoles, dipoles, relative calibration, and bandpass errors) are fitted jointly with the sky model, and best-fit values are tabulated. For polarization, the model includes CMB, synchrotron, and thermal dust emission. These models provide excellent fits to the observed data, with rms temperature residuals smaller than 4 uK over 93% of the sky for all Planck frequencies up to 353 GHz, and fractional errors smaller than 1% in the remaining 7% of the sky. The main limitations of the temperature model at the lower frequencies are degeneracies among the spinning dust, free-free, and synchrotron components; additional observations from external low-frequency experiments will be essential to break these. The main limitations of the temperature model at the higher frequencies are uncertainties in the 545 and 857 GHz calibration and zero-points. For polarization, the main outstanding issues are instrumental systematics in the 100-353 GHz bands on large angular scales in the form of temperature-to-polarization leakage, uncertainties in the analog-to-digital conversion, and very long time constant corrections, all of which are expected to improve in the near future.

Planck2015 results

We discuss the Galactic foreground emission between 20 and 100 GHz based on observations by Planck and WMAP. The total intensity in this part of the spectrum is dominated by free-free and spinning dust emission, whereas the polarized intensity is dominated by synchrotron emission. The Commander component-separation tool has been used to separate the various astrophysical processes in total intensity. Comparison with radio recombination line templates verifies the recovery of the free-free emission along the Galactic plane. Comparison of the high-latitude Hα emission with our free-free map shows residuals that correlate with dust optical depth, consistent with a fraction (≈30%) of Hα having been scattered by high-latitude dust. We highlight a number of diffuse spinning dust morphological features at high latitude. There is substantial spatial variation in the spinning dust spectrum, with the emission peak (in Iν) ranging from below 20 GHz to more than 50 GHz. There is a strong tendency for the spinning dust component near many prominent H ii regions to have a higher peak frequency, suggesting that this increase in peak frequency is associated with dust in the photo-dissociation regions around the nebulae. The emissivity of spinning dust in these diffuse regions is of the same order as previous detections in the literature. Over the entire sky, the Commander solution finds more anomalous microwave emission (AME) than the WMAP component maps, at the expense of synchrotron and free-free emission. This can be explained by the difficulty in separating multiple broadband components with a limited number of frequency maps. Future surveys, particularly at 5–20 GHz, will greatly improve the separation by constraining the synchrotron spectrum. We combine Planck and WMAP data to make the highest signal-to-noise ratio maps yet of the intensity of the all-sky polarized synchrotron emission at frequencies above a few GHz. Most of the high-latitude polarized emission is associated with distinct large-scale loops and spurs, and we re-discuss their structure. We argue that nearly all the emission at 40deg > l > −90deg is part of the Loop I structure, and show that the emission extends much further in to the southern Galactic hemisphere than previously recognised, giving Loop I an ovoid rather than circular outline. However, it does not continue as far as the “Fermi bubble/microwave haze”, making it less probable that these are part of the same structure. We identify a number of new faint features in the polarized sky, including a dearth of polarized synchrotron emission directly correlated with a narrow, roughly 20deg long filament seen in Hα at high Galactic latitude. Finally, we look for evidence of polarized AME, however many AME regions are significantly contaminated by polarized synchrotron emission, and we find a 2σ upper limit of 1.6% in the Perseus region.

Revised single‐spacecraft method for determining wave vector k and resolving space‐time ambiguity

AbstractA practical method is proposed for determining the wave vector of waves from single‐spacecraft measurements. This wave vector knowledge can then be used to remove the space‐time ambiguity produced by frequency Doppler shift associated with spacecraft motion. The method involves applying the Wiener‐Khinchin theorem to cross correlations of the current and magnetic field oscillations and to autocorrelations of the magnetic field oscillations. The method requires that each wave frequency component map to a unique wave vector, a condition presumed true in many spacecraft measurement situations. Examples validating the method are presented.

Resting-State Functional MR Imaging for Determining Language Laterality in Intractable Epilepsy.

Purpose To measure the accuracy of resting-state functional magnetic resonance (MR) imaging in determining hemispheric language dominance in patients with medically intractable focal epilepsies against the results of an intracarotid amobarbital procedure (IAP). Materials and Methods This study was approved by the institutional review board, and all subjects gave signed informed consent. Data in 23 patients with medically intractable focal epilepsy were retrospectively analyzed. All 23 patients were candidates for epilepsy surgery and underwent both IAP and resting-state functional MR imaging as part of presurgical evaluation. Language dominance was determined from functional MR imaging data by calculating a laterality index (LI) after using independent component analysis. The accuracy of this method was assessed against that of IAP by using a variety of thresholds. Sensitivity and specificity were calculated by using leave-one-out cross validation. Spatial maps of language components were qualitatively compared among each hemispheric language dominance group. Results Measurement of hemispheric language dominance with resting-state functional MR imaging was highly concordant with IAP results, with up to 96% (22 of 23) accuracy, 96% (22 of 23) sensitivity, and 96% (22 of 23) specificity. Composite language component maps in patients with typical language laterality consistently included classic language areas such as the inferior frontal gyrus, the posterior superior temporal gyrus, and the inferior parietal lobule, while those of patients with atypical language laterality also included non-classical language areas such as the superior and middle frontal gyri, the insula, and the occipital cortex. Conclusion Resting-state functional MR imaging can be used to measure language laterality in patients with medically intractable focal epilepsy. (©) RSNA, 2016 Online supplemental material is available for this article.

Comment on “Total Probability Theorem Versus Shakeability: A Comparison between Two Seismic‐Hazard Approaches Used in Central Asia” by D. Bindi and S. Parolai: Table 1

The recent paper of D. Bindi and S. Parolai (Bindi and Parolai, 2015; hereafter referred to as BP15) considers discrepancies between variants of seismic‐hazard estimates for central Asia. BP15 notes that for this territory the levels of hazard estimated in Ulomov et al. (1999; hereafter referred to as Ul99) during the construction of the Global Seismic Hazard Assessment Program (GSHAP) map shows a clear mismatch when compared with similar maps for neighboring areas: hazard estimates of Ul99 are systematically larger. Indeed, when Zhang et al. (1999) who were responsible for aggregating probabilistic seismic‐hazard assessment (PSHA) maps for various territories of Asia into the single final map tried to combine the component maps, the only way to incorporate the results of Ul99 was to decrease its peak ground acceleration (PGA) values by ∼30%. BP15 discusses the assumption that this problem could be caused by deficiencies of Riznichenko’s hazard estimation procedure, believed to be used in the calculating of Ul99 for GSHAP. The first deficiency under discussion is the implicit assumption of Riznichenko (1965) that the level of shaking, when considered as a function of magnitude M and distance r , can be treated in deterministic style, with no allowance for the scatter of individual observations with respect to an assumed mean relationship. Originally, Riznichenko expressed the level of shaking in terms of macroseismic intensity I , but most of the further discussion is applicable to cases when the level of shaking is expressed in any amplitude measure, further generically denoted A . The need to account for the scatter of I or A is evident (see e.g., Keilis‐Borok et al. , 1973). BP15 comes to the conclusion that their initial guess is untrue: the possible assumption of zero …

Probing neuronal activation by functional quantitative susceptibility mapping under a visual paradigm: A group level comparison with BOLD fMRI and PET

Dynamic changes of brain-tissue magnetic susceptibility provide the basis for functional MR imaging (fMRI) via T2*-weighted signal-intensity modulations. Promising initial work on a detection of neuronal activity via quantitative susceptibility mapping (fQSM) has been published but consistently reported on ill-understood positive and negative activation patterns (Balla et al., 2014; Chen and Calhoun, 2015a). We set out to (i) demonstrate that fQSM can exploit established fMRI data acquisition and processing methods and to (ii) better describe aspects of the apparent activation patterns using fMRI and PET as standards of reference. Under a standardized visual-stimulation paradigm PET and 3-T gradient-echo EPI-based fQSM, fMRI data from 9 healthy volunteers were acquired and analyzed by means of Independent Component Analysis (ICA) at subject level and, for the first time, at group level. Numbers of activated (z-score>2.0) voxels were counted and their mean z-scores calculated in volumes of interest (occipital lobe (Nocc_lobe), segmented occipital gray-matter (NGM_occ_lobe), large veins (Nveins)), and in occipital-lobe voxels commonly activated in fQSM and fMRI component maps. Common but not entirely congruent regions of apparent activation were found in the occipital lobe in z-score maps from all modalities, fQSM, fMRI and PET, with distinct BOLD-negatively correlated regions in fQSM data. At subject-level, Nocc_lobe, NGM_occ_lobe and their mean z-scores were significantly smaller in fQSM than in fMRI, but their ratio, NGM_occ_lobe/Nocc_lobe, was comparable. Nveins did not statistically differ and the ratio Nveins/NGM_occ_lobe as well as the mean z-scores were higher for fQSM than for fMRI. In veins and immediate vicinity, z-score maps derived from both phase and fQSM-data showed positive and negative lobes resembling dipole shapes in simulated field and phase maps with no correlate in fMRI or PET data. Our results show that standard fMRI tools can directly be used for fQSM processing, and suggest that fQSM may have the potential to detect gray-matter activation distant from large veins, to improve detection of veins with stimulus-induced venous oxygen saturation (SvO2) variations, and to better localize areas of activation. However, our results seem to clearly expose issues that phenomenologically resemble an incomplete dipolar inversion and that need to be subject to further investigation.