Low-energy Component Research Articles

On the unified view of extragalactic sources based on their broadband emission properties

Our understanding of the unification of jetted AGNs has advanced greatly as the size of extragalactic sources increased. In the present paper, based on the large sample of radio sources, we compiled 680 blazars (279 FSRQs and 401 BL Lacs) from the 3FGL sample and 64 Seyfert galaxies (3 Narrow-line, 34 and 27 regular Seyfert 1 and Seyfert 2 respectively) from the INTEGRAL survey to statistically test the relationship between Seyfert galaxies and the blazar samples of FSRQs and BL Lacs. We compute the synchrotron (SS), Compton (CS) and inverse Compton (IC) continuous spectra from the low energy components of radio to X-ray, radio to gamma-ray and the high energy component of X-ray to gamma-ray bands, respectively. Results show from the distributions of the continuous spectra that Seyfert galaxies form the tail of the distributions, suggestive of similar underlying history and evolution. A two-sample Kolmogorov-Smirnov test (K.S test) of the continuous spectra showed that Seyfert galaxies differ from BL Lacs and FSRQs in the low energy components of the spectra, while there is no clear difference between them in the high energy component, which implies that high energy emissions in Seyfert galaxies, BL Lacs and FSRQs may be as a result of the same emission mechanism. There is a regular sequence of the distributions on SS/CS and IC/CS planes in each individual subsample. Linear regression analyses of our sample yield significant positive correlations (r greater than 0.60) between SS/CS and IC/CS data. This upturns into an anti-correlation (r greater than -0.60) in IC/SS data. These results are not only consistent with unified scheme for blazars but also show that Seyfert galaxies can be unified with the classical radio-loud AGNs counterparts.

Doublet luminescence due to coexistence of excitons and electron-hole plasmas in optically excited CH3NH3PbBr3 single crystal

Doublet luminescence from hybrid metal trihalide perovskite semiconductors is observed along with materials processing when high-quality single crystals are obtainable. Yet, the underlying physical mechanism remains poorly understood. Here, we report controllable solution-processed crystallization that affords high-quality CH3NH3PbBr3 single crystals with atomically flat pristine surfaces. Front-face photoluminescence (PL) shows doublet luminescence components with variable relative intensities depending on the crystal surface conditions. We further find that the low-energy PL component with asymmetric spectral line-shape becomes predominant when the atomically flat crystal surfaces are passivated in the ion-abundant saturated solutions, while poor-quality single crystal with visually rough surface only gives the high-energy PL with symmetric line-shape. The asymmetric spectral line-shape of the low-energy PL matches perfectly with the simulated bandedge emission. Therefore, the low-energy PL component is attributable to the intrinsic bandedge emission from the crystal bulk while the high-energy one to surface-specific emission. Elliott fitting to the absorption data and multi-exponential fitting to the time-resolved photoluminescence traces jointly indicate the coexistence of excitons and electron–hole plasmas in optically excited CH3NH3PbBr3 single crystals, thereby catching the physical merit that leads to the occurrence of doublet luminescence.

Asymmetric and symmetric fission of excited nuclei of Hg180,190 and Pb184,192,202 formed in the reactions with Ar36 and Ca40,48 ions

Background: Observation of asymmetric fission of $^{180}\mathrm{Hg}$ has led to intensive theoretical and experimental studies of fission of neutron-deficient nuclei in the lead region.Purpose: The study of asymmetric and symmetric fission modes of $^{180,190}\mathrm{Hg}$ and $^{184,192,202}\mathrm{Pb}$ nuclei.Methods: Mass-energy distributions of fission fragments of $^{180,190}\mathrm{Hg}$ and $^{184}\mathrm{Pb}$ formed in the $^{36}\mathrm{Ar}+^{144,154}\mathrm{Sm}$ and $^{40}\mathrm{Ca}+^{144}\mathrm{Sm}$ reactions, respectively, at energies near the Coulomb barrier have been measured using the double-arm time-of-flight spectrometer CORSET and compared with previously measured $^{192,202}\mathrm{Pb}$ isotopes produced in the $^{48}\mathrm{Ca}+^{144,154}\mathrm{Sm}$ reactions. The mass distributions for $^{180,190}\mathrm{Hg}$ and $^{184,192,202}\mathrm{Pb}$ together with old data for $^{187}\mathrm{Ir}, ^{195}\mathrm{Au}, ^{198}\mathrm{Hg}, ^{201}\mathrm{Tl}, ^{205,207}\mathrm{Bi}, ^{210}\mathrm{Po}$, and $^{213}\mathrm{At}$ [J. Nucl. Phys. 53, 1225 (1991)] have been decomposed into symmetric and asymmetric fission modes. The total kinetic-energy distributions for different fission fragment mass regions have been analyzed for $^{180,190}\mathrm{Hg}$ and $^{184}\mathrm{Pb}$.Results: The stabilization role of proton numbers at $Z\ensuremath{\approx}36$, 38, $Z\ensuremath{\approx}45$, 46, and $Z=28/50$ in asymmetric fission of excited preactinide nuclei has been observed. The high ($\ensuremath{\approx}145\text{\ensuremath{-}}\mathrm{MeV}$) and the low ($\ensuremath{\approx}128\text{\ensuremath{-}}\mathrm{MeV}$) energy components have been found in the total kinetic-energy distributions of $^{180,190}\mathrm{Hg}$ fission fragments corresponding to the fragments with proton numbers near $Z\ensuremath{\approx}46$ and $Z\ensuremath{\approx}36$, respectively. In the case of fission of $^{184}\mathrm{Pb}$ only the low-energy component ($\ensuremath{\approx}135\phantom{\rule{0.16em}{0ex}}\mathrm{MeV}$) for the fragments with masses corresponding to the proton numbers $Z\ensuremath{\approx}36$ and 46 has been found.Conclusions: The studied properties of asymmetric fission of $^{180,190}\mathrm{Hg}$ and $^{184,192,202}\mathrm{Pb}$ nuclei point out the existence of well deformed proton shell at $Z\ensuremath{\approx}36$ and less deformed proton shell at $Z\ensuremath{\approx}46$.

Exergy hub based modelling and performance evaluation of integrated energy system

Efficient energy deployment, fossil fuel sources reduction and Intermittent Renewable Energy Sources (IRES) integration has become a core goal of power system operators to attain sustainable and environmentally benign energy system. In such context, Integrated Energy System (IES) is a promising solution to improve system performance by coupling various energy carriers in an energy hub to fulfill diverse consumers’ energy needs. However, the widely used criteria for energy system modelling is based on energy analysis that considers energy quantity only and neglects energy quality. Consequently, exergy index computation becomes a vital issue that accounts energy quantity along with energy quality to provide an accurate assessment. Hence, this paper proposes an exergy hub approach to model IES that constitutes electricity, District Heating (DH) and Individual Heating (IH) infrastructure of China for the year 2020. At first, the exergy efficiency of energy-producing components is calculated by using Cycle-Tempo and Engineering Equation Solver (EES). Then, IES performance is evaluated by computing annual costs, Primary Energy Supply (PES), CO2 emissions and renewable energy share with the help of EnergyPLAN technical simulation strategy. These aforementioned performance indicators are investigated for three different cases like IRES maximum integration in electricity infrastructure (Case 1), Heat Pump (HP) inclusion in IH infrastructure (Case 2) and Thermal Storage (TS) addition in DH infrastructure (Case 3) and these cases comparison with energy hub results are also provided. Energy and exergy hub approaches substantiate different results as IRES integration proves the most cost-efficient and decarbonized alternative in exergy hub while in energy hub TS addition is the best case alternative. Though IRES integration deemed cost-efficient with reduced emissions in exergy hub but in comparison to energy hub, this case is costly as exergy efficiency of IRES are lower than energy efficiency. Similarly, HP and TS exergetic results are inferior to energetic because high quality energy is being exploited to produce low quality energy and heat producing components are less exergetically efficient.

Fermi/GBM Observations of the SGRJ1935+2154 Burst Forest

Abstract During 2020 April and May, SGR J1935+2154 emitted hundreds of short bursts and became one of the most prolific transient magnetars. At the onset of the active bursting period, a 130 s burst “forest,” which included some bursts with peculiar time profiles, were observed with the Fermi/Gamma-ray Burst Monitor (GBM). In this Letter, we present the results of time-resolved spectral analysis of this burst “forest” episode, which occurred on 2020 April 27. We identify thermal spectral components prevalent during the entire 130 s episode; high-energy maxima appear during the photon flux peaks, which are modulated by the spin period of the source. Moreover, the evolution of the ν F ν spectral hardness (represented by E peak or blackbody temperature) within the lightcurve peaks is anti-correlated with the pulse phases extrapolated from the pulsation observed within the persistent soft X-ray emission of the source six hours later. Throughout the episode, the emitting area of the high-energy (hotter) component is 1–2 orders of magnitude smaller than that for the low-energy component. We interpret this with a geometrical viewing angle scenario, inferring that the high-energy component likely originates from a low-altitude hotspot located within closed toroidal magnetic field lines.

Recent, Bioelectricity-Related Articles Selected by Ann M. Rajnicek, Media Editor of Bioelectricity.

Recent, Bioelectricity-Related Articles Selected by Ann M. Rajnicek, Media Editor of Bioelectricity.

A Systematic Study of Gamma-Ray Flares from the Crab Nebula with Fermi-LAT. I. Flare Detection

Abstract Significant flares of GeV γ-ray emission from the Crab Nebula were found by AGILE and Fermi-LAT years ago, indicating that extreme particle acceleration and radiation occurs in young pulsar wind nebulae. To enlarge the flare sample and to investigate their statistical properties will be very useful in understanding the nature of the γ-ray flares. In this paper, we investigate the flaring emission from the Crab Nebula with eleven year observations of the Fermi-LAT. We identify 17 significant flares in the light curve of the low-energy (synchrotron) component of the γ-ray emission. The flare rate is about 1.5 per year, without any significant change or clustering during the 11 years of the observation. We detect a special flare with an extremely long duration of nearly one month, that occurred in 2018 October, with synchrotron photons up to energies of about 1 GeV. The synchrotron component could be fitted by a steady power-law (PL) background and a variable flare component with an exponentially cutoff PL spectrum, not only for the individual flare but also for the combined data, which may favor a similar emission mechanism for all flares. However, we do not find a universal relation between the cutoff energy and the energy fluxes of the flares, which may reflect the complicated acceleration and/or cooling processes of the involved particles.

Investigation of the attenuation of the fluxes of the low-energy plasma component of electric rocket engines by the ventilation holes of the unpressurized instrument compartment of the spacecraft

The results of an experimental study of the attenuation of the fluxes of the low-energy component of the plasma formed during the operation of electric propulsion engines (ERE), ventilation holes (VH) of the non-sealed equipment compartment (NSEC) of the spacecraft (SC) are presented. Authors studied the attenuation of plasma fluxes by standard VHs made in honeycomb panels that form the NSEC. A Hall-effect engine of the SPT-70 type was used as a plasma source. The experiment consisted of measuring the plasma concentration at the inlet and outlet of the VH. The concentration at the inlet was measured with a flat Langmuir probe, and at the outlet with a Faraday probe, which allows collecting all ions passing through the VH. The aim of the work was to study the weakening of the fluxes of the lowenergy component of the EJE plasma when passing through the VH in the honeycomb-nels that form the NSEC. Based on the experimental data, a semi-empirical model was constructed that describes the dependence of the attenuation coefficient of plasma flows on the geometric parameters of the vent-holes. It has been established that a vent-holes of this design attenuates the plasma flows by 102 ... 104 times. The largest contribution to the weakening of plasma fluxes is made by the honeycomb filler, which is due to the recombination of ions during their collision with the channel walls. Taking into account the attenuation of the fluxes of the low-energy component of the plasma of electric rocket engines by ventilation holes is a key stage in assessing the effect of plasma on the power on-board equipment of spacecraft and should be used by spacecraft developers when analyzing the resistance to this factor.

Energy and angular distribution of photo-neutrons for 16.6 MeV polarized photon on medium–heavy targets

The energy spectra as well as the angular distribution of photo-neutrons, called the double differential cross sections (DDXs) of the (γ, xn) reaction were measured for 16.6 MeV linearly polarized photons on Pb, Au, Sn, Cu, Fe, and Ti targets. Polarized photons were prepared using the laser Compton scattering technique at BL01, NewSUBARU, Hyogo, Japan. The photo-neutrons were measured using liquid organic scintillators, placed at six different angles. The time-of-flight technique was used to determine the neutron energy. The low energy and high energy components on the DDXs were identified for all the targets. Flat angular dependence was observed for the low energy component; however, a cos(2Θ) distribution was observed for the high energy component, where Θ is the angle between the photon polarization direction and neutron emission. The angular dependences were parameterized by fitting the experimental data. The obtained parameters were compared with those from previous studies conducted decades ago.

Catechol functionalized hat-shape carriers for prolonging pesticide retention and flush resistance on foliage

• Cat-HSCs are synthesized via grafting foliar affinity polymer onto the surface of HSCs. • Cat-HSCs can take advantage of both non-covalent interactions and topology effect between the pesticide and foliage. • The target retention and flush resistance of Cat-HSCs on rice/wheat leaves are greatly enhanced. • Cat-HSCs possess a better release property and satisfactory efficacy in controlling wheat powdery mildew. Retention, a crucial process in pesticide spraying, is closely related to pesticide utilization efficiency and severely impacted by both low surface energy components and micro/nanostructures of foliage. To date, many pesticide carriers have been designed based on either foliar components or structures to enhance pesticide retention. However, as far as we know, there have been no reports taking these two factors into account simultaneously. Herein, we present a novel strategy to address this issue by taking advantage of both non-covalent interactions and topology effect between pesticide carriers and crop leaves. By grafting adhesive catechol-containing polymers onto the surface of hat-shape carriers (HSCs) via a one-step esterification reaction, a series of pesticide-loaded catechol functionalized hat shape carriers (pesticide-loaded Cat-HSCs ) with high loading capacity were successfully prepared. Upon spraying on rice and wheat leaves, these functionalized carriers could target both the micropapillae and nanosplinters on foliage driven by the “hanger-hat” topology effect and non-covalent interactions, resulting in great improvement of foliar affinity, pesticide retention, and flush resistance. Moreover, pesticide-loaded Cat-HSCs possess a 15-day sustained-release property and satisfactory efficacy in controlling wheat powdery mildew. Overall, our resource-saving pesticide carrier provides an effective strategy for prolonging pesticide retention and reducing pesticide loss in agro-production.

Dual-Energy X-ray Medical Imaging with Inverse Compton Sources: A Simulation Study

It has been long recognized that dual-energy imaging could help to enhance the detectability of lesions in diagnostic radiology, by removing the contrast of surrounding tissues. Furthermore, X-ray attenuation is material specific and information about the object constituents can be extracted for tissue characterisation, i.e., to assess whether lesions represent a malignant or benign process. However, a true separation between the low and high energy components is not possible with conventional sources because of their broad X-ray spectrum, and the artifacts produced in the subtracted image can be only partially removed. Finally, dose issues have also prevented so far the application of dual-energy techniques within the clinical context. Very recently, a new intense and monochromatic X-ray source was proposed to fill the gap between a synchrotron radiation facility and the standard X-ray tube. Indeed, inverse Compton scattering (ICS) sources, which are based on the interaction of a powerful laser beam and a bright beam of relativistic electrons, are among the most promising innovative sources of monochromatic X and gamma radiation. In this contribution, we review the main features that allow an ICS source to meet the requirements of a medical imaging application. Specific examples of K-edge subtraction are then provided, to show the potential of ICS in clinical applications that require intravenous injection of a contrast medium.

Scale-Phobic Surfaces Made of Rare Earth Oxide Ceramics.

Scaling or precipitation fouling involves crystallization of hard and chalky solid salts from a solution. Scaling results in significant production and energy losses and is a major concern in many industries. Here we investigate the scale-phobicity of rare earth oxide (REO) ceramics (particularly CeO2, Gd2O3, and Er2O3) in comparison with glass and stain-less steel. We quantify the surface energy and its polar and apolar components for these materials using the Van Oss-Chaudhury-Good approach and show a direct correlation between surface energy and scale deposition. We also show that the polar component of surface energy is the main contributor to scale deposition; hence, REOs with minimal polar component represent high barrier to scale deposition. Moreover, we study the weight gain due to calcium sulfate dihydrate (gypsum) scale accumulation on these materials and show 55% and 77% reduction on REOs in comparison with bare glass and stainless-steel, respectively. We also evaluate the adhesion forces between salt and test materials using atomic force microscopy with a gypsum microparticle adhered onto a tipless cantilever. We show adhesion force between salt particles and REO surfaces is about half that of bare glass and stainless-steel because of the lower surface energy and polar component. We expect REO ceramics would find widespread applicability as robust scale-phobic surfaces in various industries.

Influence of composition and size on the thermodynamic stability and structural evolution of CuAlNi nanoclusters

The heating process for CuAlNi nanoclusters with cuboctahedral structure was studied by molecular dynamics simulation with the embedded atom method. A diffusionless martensitic transformation from the cuboctahedral (CO) to the icosahedral (ICO) structure before the melting point was found in some CuAlNi nanoclusters. The effects of element composition and cluster size on the thermodynamic stability and structural transformation of trimetallic nanoclusters were investigated. The results show that the CO–ICO transformation temperature was size-dependent and occurred only for small clusters. It was also observed that the CO–ICO transformation temperature firstly dropped and then raised as Al concentration increased, which may be strongly related to the release of excess energy. Furthermore, the surface segregation phenomenon was also observed that the lower surface energy components, such as Al and Cu atoms, segregated to the surface of CuAlNi nanoclusters. The changes in the melting points of CuAlNi nanoclusters with different alloy compositions and cluster sizes were also studied. And furthermore, the physical basis of structural transition of CuAlNi nanoclusters was discussed.

An interfacial chemistry study of methylene diphenyl diisocyanate and tantalum for heat exchanger applications

The interactions between oxidised tantalum and methylene diphenyl diisocyanate (MDI) have been investigated by X‐ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (ToF‐SIMS). Thin (approximately 2 nm) and thick layers of polymeric MDI were deposited on tantalum; one set was cured at 200°C, the other dried at ambient temperature (20°C). The thick layers serve as a characteristic pMDI layer, and thin layers contain information relating to the nature of interfacial bonding. By careful fitting of the N1s region contributions relating to interfacial bonding have been established. All spectra show an Nδ+ contribution indicative of acid–base bonding; in the case of the thick films, this is of an intermolecular nature whereas in the thin films, the more intense contribution is a result of such forces between pMDI and substrate. This is confirmed by ToF‐SIMS. A lower binding energy component at ca 396 eV on the air‐dried thin layer of pMDI is the result of a formal reaction between pMDI and tantalum yielding a nitride‐like species in the N1s spectrum.

PLANNING AND PROGRAMMING OF TRAINING IN THE COMPETITIVE PERIOD IN WOMEN'S FOOTBALL

Training planning and programming make up a very complex process, especially planning and programming during the competition period. The women’s soccer competition lasts a total of five to six months and is divided into two subseasons. The competition period is a mesocycle period that is made up of multiple microcycles. During this period, intensive training work is carried out for the football players to reach the highest level of their abilities. Coaches need to know how to manage their sports form for football players to be most ready for the most important phase of the competition. In order to maintain it, it is necessary to conduct training of specific and situational fitness exercises that connect the functional, motor, and technical-tactical goals. The intensity of such training should be very high (80-100%). The share of fitness training in the competition period should be around 30%, and studies have shown that 1-2 stimuli per week are required to maintain fitness abilities, provided the intensity is high. The seven-day microcycle consists of 5 individual training sessions, matches, and rest days. The footballers play 20-25 games of different difficulty and importance during the season. The schedule of these matches determines the dynamics of the load, which means that if the match is important in the microcycle, the lower energy component of the load is applied and vice versa. Coaches and professional staff should be continuously educated in the form of planning and programming sports training, to acquire new knowledge about sports form management in all periods, phases, and conditions during the season, with special emphasis on the competition period.

Mitigating the Effects of Charged Particle Strikes on TES Arrays for Exotic Atom X-ray Experiments

Exotic atom experiments place transition-edge-sensor (TES) microcalorimeter arrays in a high-energy charged particle rich environment. When a high-energy charged particle passes through the silicon substrate of a TES array, a large amount of energy is deposited and small pulses are generated across multiple pixels in the TES array due to thermal crosstalk. We have developed analysis techniques to assess and reduce the effects of charged particle events on exotic atom X-ray measurements. Using this technique, the high-energy and low-energy components of the X-ray peaks due to pileup are eliminated, improving the energy resolution from 6.6 eV to 5.7 eV at 6.9 keV.

Multiferroic nanoparticles of Ni doped CoCr2O4: An XPS study

Three spinel compounds, namely CoCr2O4, (Co0.75Ni0.25)Cr2O4, and (Co0.5Ni0.5)Cr2O4 were investigated using x-ray photoelectron spectroscopy techniques. These compounds were synthesized using sol-gel techniques. The gel was dried and subsequently calcined at 600 °C to achieve crystallinity and the correct cubic phase. The survey scans of the analyzed samples with detailed spectra of the Co 2p, Ni 2p, Cr 2p, O 1s, and the valence band were collected. The core levels are found to be asymmetric and have multiple components. Ni and Co have 2+/3+ oxidation states, whereas Cr prefers 3+ oxidation state. The O 1s core level demonstrates three components. The low binding energy component refers to the lattice oxygen atoms, whereas the two high binding energy components correspond to the surface adsorbed hydroxyl groups resulting from water and the alcohol used for the synthesis of these nanoparticles. The data emanating from this study are reported.

Stochastic acceleration in the relativistic jets of BL Lacertae objects

BL Lacertae objects (BL Lacs) constitute a rare class of active galactic nuclei (AGNs) with the extreme observational features attributed to the Doppler-boosted emission from the relativistic jets, closely aligned along our line-of-sight. The spectral energy distribution (SED), extending over 17–19 orders of the frequency from the radio to the TeV energy range, is of nonthermal origin and shows a typical two-component structure. The lower-energy component, which ranges from the radio to the X-ray frequencies, is widely accepted to be a synchrotron radiation emitted by relativistic electrons. The latter can be accelerated and collimated via the Blandford-Znajek mechanism or magneto-hydrodynamic processes in the vicinity of the central super-massive black hole. However, the accelerated particles should loose the energy, sufficient for the emission of the KeV-TeV photons, very quickly and they require an additional acceleration via the mechanisms operating locally in the jet. According to the different studies and simulations, particles can undergo a strong stochastic (second-order Fermi) acceleration due to the resonant scattering of the magnetohydrodynamic waves, representing the turbulent magnetic irregularities. On the other hand, the jet turbulence can be strongly amplified due to the interaction between the shock front and the density inhomogeneities in the pre-shock relativistic jet fluid. Our intense X-ray spectral study of TeV-detected, bright BL Lacs (Mrk 421, 1ES 1959 + 650, Mrk 501) often demonstrate the signatures of the efficient stochastic acceleration (a low spectral curvature and different correlations expected within the stochastic process). We have also detected the cases when these sources show the relation between the synchrotron SED peak location Ep and peak height Sp in the form Sp∝Epα with the values of the exponent close to 0.6. The latter is expected when the momentum-diffusion coefficient and the turbulence spectrum are variable during the stochastic acceleration process: there is a transition from the Kraichnan-type into the hard-sphere turbulence.

Spectroscopic Studies of a Phosphonium Ionic Liquid in Supercritical CO2

Fluorescence spectroscopy was used to study a solution comprised of coumarin 153 (C153)+ trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide ([P6,6,6,14]+ [Tf2N]−)+ supercritical CO2 (scCO2). We compare the spectroscopy of C153 in neat scCO2 to that of C153/scCO2 with the addition of ionic liquid (IL). Excitation and emission peak frequencies of C153 in scCO2 and in IL/scCO2 diverged at reduced densities (ρr = ρ/ρc) below the CO2 critical density. At low fluid density, spectral changes in the IL/scCO2 solutions showed evidence that C153 experiences a very different microenvironment—one that is unlike neat scCO2. The data show that the presence of IL clearly influences the C153 excitation and emission profiles. Excitation was broadened and red shifted by >2000 cm−1 and the presence of an additional low-energy emission component that was red shifted by ~3000 cm−1 was clearly visible and not observed in neat scCO2. The solution heterogeneity was controlled by changing the scCO2 density and at high fluid density, both the excitation and emission spectra were more similar to those in neat scCO2. Steady-state anisotropy also showed that at low fluid density, the C153 emission was significantly polarized. Aggregation of C153 has been reported in the literature and this led us to hypothesize the possibility that C153 dimer (aggregation) formation may be occurring in scCO2. Another possible explanation is that dye–IL aggregates may dissolve into the scCO2 phase due to C153 acting as a “co-solvent” for the IL. Time-resolved intensity decay measurements yielded only slightly non-exponential decays with accompanying time constants of ~3–4 ns that were significantly shorter than the 5–6 ns time constants in neat scCO2, which are suggestive of C153–IL interactions. However, these data did not conclusively support dimer formation. Pre-exponential factors of the time constants showed that almost all of the emission was due to monomeric C153.

Evaluating Advancements in Bluetooth Technology for Travel Time and Segment Speed Studies

Application of Bluetooth technology has become ubiquitous in the current age of transportation research. The purpose of this article is to explore advancements of Bluetooth technology, applied to transportation studies, using performance metrics such as match rate, travel time, and segment speed through analyzing collected data from several Bluetooth devices. Specifically, the study explores the performance of two advanced Bluetooth devices coupled with classic Bluetooth technology: the demodulator (BT DM), and the low-energy Bluetooth signal additional component (BLE). Data were collected in two locations/phases: (1) along a 0.59-mi segment of interstate and (2) along a 0.52-mi segment of an urban arterial road in Baton Rouge, LA. The data collected were compared with benchmark data sets, gathered during the same period, using manual counts from video footage, radar data, and floating car data (FCD). Comparative analysis showed that BLE produced significantly higher matched rates than BT DM. Furthermore, BLE was able to maintain higher accuracy with increased levels of detection. Results of a Kruskal–Wallis test showed BT DM to have a statistically significant difference with FCD during only one out of three peak periods along the interstate segment. However, BLE matched closest with FCD along the interstate, but shared a significant difference with the benchmark data set during two peak periods along the urban arterial roadway. Considering the level of detection with the accuracy of travel times and segment speeds when compared with the benchmark data, it was evident that the BLE performed better than the BT DM.