High-energy Data Research Articles

Quantifying energy savings from replacement of old refrigerators

Abstract: Energy labelling for refrigerators in Australia has been in force for over 30 years. It is well documented that the label energy consumption of refrigerators and freezers has fallen dramatically over that period. While a number of studies have measured the energy consumption of refrigerating appliances in the field, the data is very complex and difficult to interpret. Field data measured in houses has constantly fluctuating room temperatures and is subject to somewhat random interactions with householders through door openings and the placement of food and drinks to be cooled. Another problem with field data is that household indoor temperatures are quite seasonal and significant periods of data are required to quantify these effects. This paper analyses the results of 21 refrigerator replacements that have occurred in Melbourne, Gippsland (Victoria) and Sydney over the past four years. Seven of the replacements were part of a Victorian State Government retrofit program that targeted the removal and replacement of older refrigerators with the best on the market. The remaining 14 appliances were replaced during routine monitoring by the author as part of his PhD field work at The University of Melbourne. The study is unique as high quality refrigerator energy and temperature data was broken down into 4 key components: temperature driven energy consumption, energy consumption from user interactions, base defrosting requirements and user driven defrosting requirements. This approach allows the old and new appliances to be directly compared when modelled under identical operating conditions giving a fair and robust comparison. The results are impressive, with average energy reductions of 60%, ranging from 30% to more than 80%, depending on the household circumstances and the old and new appliances.

High-energy Gamma Rays from the Milky Way: Three-dimensional Spatial Models for the Cosmic-Ray and Radiation Field Densities in the Interstellar Medium.

High-energy γ-rays of interstellar origin are produced by the interaction of cosmic-ray (CR) particles with the diffuse gas and radiation fields in the Galaxy. The main features of this emission are well understood and are reproduced by existing CR propagation models employing 2D galactocentric cylindrically symmetrical geometry. However, the high-quality data from instruments like the Fermi Large Area Telescope reveal significant deviations from the model predictions on few to tens of degrees scales, indicating the need to include the details of the Galactic spiral structure and thus requiring 3D spatial modeling. In this paper, the high-energy interstellar emissions from the Galaxy are calculated using the new release of the GALPROP code employing 3D spatial models for the CR source and interstellar radiation field (ISRF) densities. Three models for the spatial distribution of CR sources are used that are differentiated by their relative proportion of input luminosity attributed to the smooth disk or spiral arms. Two ISRF models are developed based on stellar and dust spatial density distributions taken from the literature that reproduce local near- to far-infrared observations. The interstellar emission models that include arms and bulges for the CR source and ISRF densities provide plausible physical interpretations for features found in the residual maps from high-energy γ-ray data analysis. The 3D models for CR and ISRF densities provide a more realistic basis that can be used for the interpretation of the nonthermal interstellar emissions from the Galaxy.

Photoproduction of γp→K+Λ*(1520) and decay of Λ*(1520)→K−p in the Reggeized framework

Photoproduction of the $\Lambda^*(1520)$ resonance of spin-parity ${3\over2}^-$ off the proton target is investigated within the Regge framework where the $t$-channel reggeization is applied for the $K(494)+K^*(892)+K_2^*(1430)$ exchanges in the Born amplitude. The present model is based on the two basic ingredients; the one is the minimal gauge prescription for the convergence of the reaction and the other is the role of the $K_2^*$ crucial to be consistent with high energy data. The cross sections for the total, differential and photon polarization asymmetry are reproduced without fit parameters and compared with existing data. The LAMP2 and LEPS measurements of the angular distribution of the $K^-$ in the $\Lambda^*(1520)\to K^-p$ decay are investigated and found to be dominated by the decay of $\Lambda^*$ with helicity $\pm3/2$ based on the analysis of the density matrix elements related. Detailed discussion on the density matrix elements is given to clarify the analysis of the observable. The reaction mechanism is featured by the dominance of the contact term with the $K$ and $K_2^*$ exchanges following in the low energy region. The $K^*$ exchange appears in minor role. At high energies beyond $E_\gamma\approx 5$ GeV the role of $K_2^*$ exchange leads over other exchanges in the reaction process.

The Beam Energy Scan at the Relativistic Heavy Ion Collider

The Beam Energy Scan (BES) at the Relativistic Heavy Ion Collider (RHIC) is based on Au + Au collision data acquired between 2010 and 2014 at beam energies of = 7.7, 11.5, 14.5, 19.6, 27 and 39 GeV. These measurements constitute Phase-I of BES (also known as BES-I), and along with higher-energy data at 62.4 and 200 GeV, they allow the phase diagram of QCD matter to be probed. BES-I has three physics goals: investigation of a turning-off of the Quark-Gluon Plasma (QGP) signatures that are by now well established at higher energies, the search for a possible first-order phase transition between hadronic and QGP phases, and the search for a possible critical point. Several promising signals have been reported, but since RHIC luminosity decreases steeply as the beam energy is scanned down, statistical errors are excessively large at the lower BES-I energies where potentially novel phenomena are observed. In 2019 and 2020, BES-II will take data with large improvements in both RHIC luminosity and in detector performance.

Spectral detector CT for cardiovascular applications.

Spectral detector computed tomography (SDCT) is a novel technology that uses two layers of detectors to simultaneously collect low and high energy data. Spectral data is used to generate conventional polyenergetic images as well as dedicated spectral images including virtual monoenergetic and material composition (iodine-only, virtual unenhanced, effective atomic number) images. This paper provides an overview of SDCT technology and a description of some spectral image types. The potential utility of SDCT for cardiovascular imaging and the impact of this new technology on radiation and contrast dose are discussed through presentation of initial patient studies performed on a SDCT scanner. The value of SDCT for salvaging suboptimal studies including those with poor contrast-enhancement or beam hardening artifacts through retrospective reconstruction of spectral data is discussed. Additionally, examples of specific benefits for the evaluation of aortic disease, imaging before transcatheter aortic valve implantation, evaluation of pulmonary veins pre- and post-pulmonary radiofrequency ablation, evaluation of coronary artery lumen, assessment of myocardial perfusion, detection of pulmonary embolism, and characterization of incidental findings are presented.

The Broadband Spectral Variability of Holmberg IX X-1

Abstract We present results from four new broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 ( erg s−1), performed by Suzaku and NuSTAR in coordination. Combined with the archival data, we now have broadband observations of this remarkable source from six separate epochs. Two of these new observations probe lower fluxes than seen previously, allowing us to extend our knowledge of the broadband spectral variability exhibited. The spectra are well fit by two thermal blackbody components that dominate the emission below 10 keV, as well as a steep ( ) power-law tail that dominates above ∼15 keV. Remarkably, while the 0.3–10.0 keV flux varies by a factor of ∼3 between all these epochs, the 15–40 keV flux varies by only ∼20%. Although the spectral variability is strongest in the ∼1–10 keV band, both of the thermal components are required to vary when all epochs are considered. We also revisit the search for iron absorption features by leveraging the high-energy NuSTAR data to improve our sensitivity to extreme velocity outflows in light of the ultra-fast outflow recently detected in NGC 1313 X-1. Iron absorption from a similar outflow along our line of sight can be ruled out in this case. We discuss these results in the context of super-Eddington accretion models that invoke a funnel-like geometry for the inner flow, and propose a scenario in which we have an almost face-on view of a funnel that expands to larger radii with increasing flux, resulting in an increasing degree of geometrical collimation for the emission from intermediate-temperature regions.

Comparative dosimetric characterization for different types of detectors in high-energy electron beams

The purpose of this study is to perform a comparison and on analysis of measured dose factor values by using various commercially available high-energy electron beam detectors to measure dose profiles and energy property data. By analyzing the high-energy electron beam data from each detector, we determined the optimal detector for measuring electron beams in clinical applications. The dose linearity, dose-rate dependence, percentage depth dose, and dose profile of each detector were measured to evaluate the dosimetry characteristics of high-energy electron beams. The dose profile and the energy characteristics of high-energy electron beams were found to be different when measured by different detectors. Through comparison with other detectors based on the analyzed data, the microdiamond detector was found to have outstanding dose linearity, a low dose-rate dependency, and a small effective volume. Thus, this detector has outstanding spatial resolution and is the optimal detector for measuring electron beams. Radiation therapy results can be improved and related medical accidents can be prevented by using the procedure developed in this research in clinical practice for all beam detectors when measuring the electron beam dose.

Multiwavelength study of VHE emission from Markarian 501 using TACTIC observations during April–May, 2012

We have observed Markarian 501 in Very High Energy (VHE) gamma-ray wavelength band for 70.6 h from 15 April to 30 May, 2012 using TACTIC telescope. Detailed analysis of ∼66.3 h of clean data revealed the presence of a TeV γ-ray signal (686± 77 γ-ray events) from the source direction with a statistical significance of 8.89σ above 850 GeV. Further, a total of 375 ± 47 γ-ray like events were detected in 25.2 h of observation from 22 – 27 May, 2012 with a statistical significance of 8.05σ indicating that the source has possibly switched over to a relatively high gamma-ray emission state. We have derived time-averaged differential energy spectrum of the state in the energy range 850 GeV - 17.24 TeV which fits well with a power law function of the form dF/dE=f0E−Γ with f0=(2.27±0.38)×10−11 photons cm−2 s−1 TeV−1 and Γ=2.57±0.15. In order to investigate the source state, we have also used almost simultaneous multiwavelength observations viz: high energy data collected by Fermi-LAT, X-ray data collected by Swift-XRT and MAXI, optical and UV data collected by Swift-UVOT, and radio data collected by OVRO, and reconstructed broad-band Spectral Energy Distribution (SED). The obtained SED supports leptonic model (homogeneous single zone) for VHE gamma-ray emission involving synchrotron and synchrotron self Compton (SSC) processes.

High Spatial Resolution Laser Desorption/Ionization Mass Spectrometry Imaging of Organic Layers in an Organic Light-Emitting Diode.

To improve the durability of organic materials in electronic devices, an analytical method that can obtain information about the molecular structure directly from specific areas on a device is desired. For this purpose, laser desorption/ionization mass spectrometry imaging (LDI-MSI) is one of the most promising methods. The high spatial resolution stigmatic LDI-MSI with MULTUM-IMG2 in the direct analysis of organic light-emitting diodes was shown to obtain a detailed mass image of organic material in the degraded area after air exposure. The mass image was observed to have a noticeably improved spatial resolution over typical X-ray photoelectron spectroscopy, generally used technique in analysis of electronic devices. A prospective m/z was successfully deduced from the high spatial resolution MSI data. Additionally, mass resolution and accuracy using a spiral-orbit TOF mass spectrometer, SpiralTOF, were also investigated. The monoisotopic mass for the main component, N,N'-di-1-naphthalenyl-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (m/z 588), was measured with a mass resolution of approximately 80,000 and a mass error of about 5 mDa using an external calibrant. This high mass resolution and accuracy data successfully deduced a possible elemental composition of partially remained material in the degraded area, C36H24, which was determined as anthracene, 9-[1,1'-biphenyl]-4-yl-10-(2-naphthalenyl) by combining structural information with high-energy CID data. The high spatial resolution of 1 μm in LDI-MSI along with high mass resolution and accuracy could be useful in obtaining molecular structure information directly from specific areas on a device, and is expected to contribute to the evolution of electrical device durability.

MCNP6 updated proton-induced fission cross section calculations at intermediate energies

MCNP6 has been Validated and Verified against intermediate- and high-energy fission cross-section experimental data. Recent improvements contained in CEM03.03F and MCNP6-F to consider precompound emission of heavy clusters up to 28 Mg has necessitated a re-calculation of fission cross sections. With our re-calculation, we find that CEM03.03F, which is used in MCNP6-F, predicts fission cross sections in good agreement with available experimental data for reactions induced by protons on both subactinide and actinide nuclei at incident energies from several tens of MeV to several GeV.

Non-standard interactions with high-energy atmospheric neutrinos at IceCube

Non-standard interactions in the propagation of neutrinos in matter can lead to significant deviations from expectations within the standard neutrino oscillation framework and atmospheric neutrino detectors have been considered to set constraints. However, most previous works have focused on relatively low-energy atmospheric neutrino data. Here, we consider the one-year high-energy through-going muon data in IceCube, which has been already used to search for light sterile neutrinos, to constrain new interactions in the μτ-sector. In our analysis we include several systematic uncertainties on both, the atmospheric neutrino flux and on the detector properties, which are accounted for via nuisance parameters. After considering different primary cosmic-ray spectra and hadronic interaction models, we improve over previous analysis by using the latest data and showing that systematics currently affect very little the bound on the off-diagonal εμτ , with the 90% credible interval given by −6.0 × 10−3< εμτ< 5.4 × 10−3, comparable to previous results. In addition, we also estimate the expected sensitivity after 10 years of collected data in IceCube and study the precision at which non-standard parameters could be determined for the case of εμτ near its current bound.

How to retrieve additional information from the multiplicity distributions

Multiplicity distributions (MDs) measured in multiparticle production processes are most frequently described by the negative binomial distribution (NBD). However, with increasing collision energy some systematic discrepancies have become more and more apparent. They are usually attributed to the possible multi-source structure of the production process and described using a multi-NBD form of the MD. We investigate the possibility of keeping a single NBD but with its parameters depending on the multiplicity N. This is done by modifying the widely known clan model of particle production leading to the NBD form of . This is then confronted with the approach based on the so-called cascade-stochastic formalism which is based on different types of recurrence relations defining . We demonstrate that a combination of both approaches allows the retrieval of additional valuable information from the MDs, namely the oscillatory behavior of the counting statistics apparently visible in the high energy data.

Searches for correlation between UHECR events and high-energy gamma-ray Fermi-LAT data

The astrophysical sources responsible for ultra high-energy cosmic rays (UHECRs) continue to be one of the most intriguing mysteries in astrophysics. We present a comprehensive search for correlations between high-energy (≳ 1 GeV) gamma-ray events from the Fermi Large Area Telescope (LAT) and UHECRs (≳ 60 EeV) detected by the Telescope Array and the Pierre Auger Observatory. We perform two separate searches. First, we conduct a standard cross-correlation analysis between the arrival directions of 148 UHECRs and 360 gamma-ray sources in the Second Catalog of Hard Fermi-LAT sources (2FHL). Second, we search for a possible correlation between UHECR directions and unresolved Fermi-LAT gamma-ray emission. For the latter, we use three different methods: a stacking technique with both a model-dependent and model-independent background estimate, and a cross-correlation function analysis. We also test for statistically significant excesses in gamma rays from signal regions centered on Cen A and the Telescope Array hotspot. No significant correlation is found in any of the analyses performed, except a weak (≲ 2σ) hint of signal with the correlation function method on scales ∼ 1°. Upper limits on the flux of possible power-law gamma-ray sources of UHECRs are derived.

Crystal Plasticity Model Validation Using Combined High-Energy Diffraction Microscopy Data for a Ti-7Al Specimen

High-Energy Diffraction Microscopy (HEDM) is a 3-d X-ray characterization method that is uniquely suited to measuring the evolving micro-mechanical state and microstructure of polycrystalline materials during in situ processing. The near-field and far-field configurations provide complementary information; orientation maps computed from the near-field measurements provide grain morphologies, while the high angular resolution of the far-field measurements provides intergranular strain tensors. The ability to measure these data during deformation in situ makes HEDM an ideal tool for validating micro-mechanical deformation models that make their predictions at the scale of individual grains. Crystal Plasticity Finite Element Models (CPFEM) are one such class of micro-mechanical models. While there have been extensive studies validating homogenized CPFEM response at a macroscopic level, a lack of detailed data measured at the level of the microstructure has hindered more stringent model validation efforts. We utilize an HEDM dataset from an alpha-titanium alloy (Ti-7Al), collected at the Advanced Photon Source, Argonne National Laboratory, under in situ tensile deformation. The initial microstructure of the central slab of the gage section, measured via near-field HEDM, is used to inform a CPFEM model. The predicted intergranular stresses for 39 internal grains are then directly compared to data from 4 far-field measurements taken between ~4 and ~80 pct of the macroscopic yield strength. The evolution of the elastic strain state from the CPFEM model and far-field HEDM measurements up to incipient yield are shown to be in good agreement, while residual stress at the individual grain level is found to influence the intergranular stress state even upon loading. Implications for application of such an integrated computational/experimental approach to phenomena such as fatigue are discussed.

Investigating the Puzzling Synchrotron Behaviour of Mrk 421

We investigate the multiwavelength behaviour of the high-energy peaked BL Lac object (HBL) Mrk 421 at redshift z = 0 . 031 in the period 2007–2015. We use optical photometric, spectroscopic, and polarimetric data and near-infrared data obtained by 35 observatories participating in the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT), as well as by the Steward Observatory Support of the Fermi Mission. We also employ high-energy data from the Swift (UV and X-rays) satellite to study correlations among emission in different bands.

Unifying leptogenesis, dark matter and high-energy neutrinos with right-handed neutrino mixing via Higgs portal

We revisit a model in which neutrino masses and mixing are described by a two right-handed (RH) neutrino seesaw scenario, implying a strictly hierarchical light neutrino spectrum. A third decoupled RH neutrino, NDM with mass MDM, plays the role of cold dark matter (DM) and is produced by the mixing with a source RH neutrino, NS with mass MS, induced by Higgs portal interactions. The same interactions are also responsible for NDM decays. We discuss in detail the constraints coming from DM abundance and stability conditions showing that in the hierarchical case, for MDM ≫ MS, there is an allowed window on MDM values necessarily implying a contribution, from DM decays, to the high-energy neutrino flux recently detected by IceCube. We also show how the model can explain the matter-antimatter asymmetry of the Universe via leptogenesis in the quasi-degenerate limit. In this case, the DM mass should be within the range 300 GeV ≲ MS < MDM ≲ 10 PeV. We discuss the specific properties of this high-energy neutrino flux and show the predicted event spectrum for two exemplary cases. Although DM decays, with a relatively hard spectrum, cannot account for all the IceCube high-energy data, we illustrate how this extra source of high-energy neutrinos could reasonably explain some potential features in the observed spectrum. In this way, this represents a unified scenario for leptogenesis and DM that could be tested during the next years with more high-energy neutrino events.

Architecture of smart clothing for standardized wearable sensor systems

The field of wearable computing has great implications in the measurement of the human body and its surrounding environment, with potentially high impact in medical applications such as early detection, treatment, compliance monitoring, care for the frail and elderly, telemedicine, physical therapy, etc. [1]. Unfortunately, the field of wearable computing is still held back by the lack of a standardized framework and development process, forcing developers into custom and time intensive solutions. In this paper, the current progress of development of a universal smart textile system is discussed which would solve this problem and accelerate the field of smart wearable electronics, providing a universal platform for attaching several hundreds of sensors to clothing in convenient, unobtrusive and energy efficient ways. The main problems and potential solutions discussed in this article include power and data transfer wire topology, allowing the textile to be arbitrarily cut and sewn into smart clothing, data transmission architecture, providing high bandwidth and low energy data transfer, and support for miniaturization and elasticity, making the potential end product as unobtrusive as possible.

Phosphorus in Sintered Steels: Effect of Phosphorus Content and P Carrier in Sintered Steel Fe-C-P

Abstract Phosphorus as an alloy element is quite common in powder metallurgy, the contents industrially used being markedly higher than those present in wrought steels. In this study, the influence of phosphorus addition through different P carriers was investigated. PM steels of the type Fe-0.7%C-x%P (x = 0.0 … 0.8%) were manufactured by pressing and sintering in H2. It showed that Fe3P is the best phosphorus carrier, resulting in fine and regular microstructure and in high impact energy data at 0.3 … 0.45%P while red P and also Fe2P showed a tendency to agglomeration, with resulting secondary porosity. At high P levels the mechanical properties tend to drop, for the tensile strength at P &gt; 0.60%P while for the impact energy the threshold is 0.45%P. The dimensional behaviour of Fe-C-P can be related to PM aluminium alloys, expansion by transient liquid phase being followed by shrinkage by persistent liquid phase, at least at higher temperatures. In contrast to the dimensional behaviour, degassing and reduction is hardly affected by the phosphorus content.

The structure of molten CuCl: Reverse Monte Carlo modeling with high-energy X-ray diffraction data and molecular dynamics of a polarizable ion model.

The results of the structural properties of molten copper chloride are reported from high-energy X-ray diffraction measurements, reverse Monte Carlo modeling method, and molecular dynamics simulations using a polarizable ion model. The simulated X-ray structure factor reproduces all trends observed experimentally, in particular the shoulder at around 1 Å(-1) related to intermediate range ordering, as well as the partial copper-copper correlations from the reverse Monte Carlo modeling, which cannot be reproduced by using a simple rigid ion model. It is shown that the shoulder comes from intermediate range copper-copper correlations caused by the polarized chlorides.

Spectral CT: On the accuracy of concentration and effective atomic number estimation

Introduction Spectral CT has been an emerging new clinical innovation that enables better discrimination and characterization of tissues. Purpose To assess the accuracy of a new fast kVp-switch spectral CT scanner in estimating the concentration and effective atomic number (Zeff) of iodine (I) in contrast enhanced tissue mimicking vessels. Materials and methods A cardiac CT phantom that simulates the chest of a medium-sized patient with respect to density and attenuation characteristics was coupled with four cylindrical vessels filled with I at 2.5 mg I/ml, 5 mg I/ml, 10 mg I/ml, and 15 mg I/ml. CT acquisitions were performed on a Revolution GSI CT scanner (General Electric, USA). The tube potential was switched from 80 kVp to 140 kVp at 4.8 kHz, while the fast response detector captured the low and high energy data sets. Spectral images in the range of 40–140 keV, iodine density images, as well as Zeff image maps were reconstructed. To investigate the effect of radiation dose on the accuracy of concentration and Zeff estimation, acquisitions were performed at different radiation dose levels. Results Measured iodine concentration and Zeff showed a strong correlation with nominal values (P〈0.001). Measurement error of iodine concentration and Zeff decreased with increasing dose from ±0.489 mg I/ml and ±0.08 at 8.91 mGy to ±0.197 mg I/ml and ±0.02 at 32.01 mGy, respectively. Conclusion Fast kVp-switch spectral CT provides accurate measurements of iodine concentration and Zeff allowing for a reliable estimate of blood volume supply in contrast-enhanced tissue vasculatures.