Energetic Data Research Articles

Magnetospheric Multiscale Observations of the Source Region of Energetic Electron Microinjections Along the Duskside, High‐Latitude Magnetopause Boundary Layer

AbstractThe present paper demonstrates the first observations by the Magnetospheric Multiscale (MMS) mission of the counter‐streaming energetic electrons and trapped energetic protons, localized in the magnetic field depressions between the mirror mode peaks, in the Earth's dusk sector high‐latitude magnetosphere. This region is characterized by high plasma beta, strong ion temperature anisotropy, and intermediate plasma density between magnetospheric and magnetosheath plasma. We show that these plasma conditions are unstable for the drift mirror instability. The counter‐streaming electron feature resembles those of the previously reported energetic electron microinjections, but without the energy‐time dispersion signature. This suggests that MMS is passing through one of the potential microinjection source regions. The energetic ion data in the present study is mainly used to estimate the scale size of the mirror mode structures.

A Quire Polycyclic Structure of N8 - A DFT Treatise

The present study considers a quire polycyclic structure of N8 and biradicals constructed from it which keep molecular integrity within the limitations of density functional theory at the levels of UB3LYP/6-311++G(2df,2p) and UB3LYP/cc-PVTZ. Certain structural, energetic, quantum chemical and spectral data have been obtained for them and discussed. The both methods of calculations generally produce parallel results.

Impact of metals on (star)dust chemistry: a laboratory astrophysics approach.

Laboratory experiments are essential in exploring the mechanisms involved in stardust formation. One key question is how a metal is incorporated into dust for an environment rich in elements involved in stardust formation (C, H, O, Si). To address experimentally this question we have used a radiofrequency cold plasma reactor in which cyclic organosilicon dust formation is observed. Metallic (silver) atoms were injected in the plasma during the dust nucleation phase to study their incorporation in the dust. The experiments show formation of silver nanoparticles (~15 nm) under conditions in which organosilicon dust of size 200 nm or less is grown. The presence of AgSiO bonds, revealed by infrared spectroscopy, suggests the presence of junctions between the metallic nanoparticles and the organosilicon dust. Even after annealing we could not conclude on the formation of silver silicates, emphasizing that most of silver is included in the metallic nanoparticles. The molecular analysis performed by laser mass spectrometry exhibits a complex chemistry leading to a variety of molecules including large hydrocarbons and organometallic species. In order to gain insights into the involved chemical molecular pathways, the reactivity of silver atoms/ions with acetylene was studied in a laser vaporization source. Key organometallic species, Ag n C2H m (n=1-3; m=0-2), were identified and their structures and energetic data computed using density functional theory. This allows us to propose that molecular Ag-C seeds promote the formation of Ag clusters but also catalyze hydrocarbon growth. Throughout the article, we show how the developed methodology can be used to characterize the incorporation of metal atoms both in the molecular and dust phases. The presence of silver species in the plasma was motivated by objectives finding their application in other research fields than astrochemistry. Still, the reported methodology is a demonstration laying down the ground for future studies on metals of astrophysical interest such as iron.

Formation of a penta- or hexacoordinated Cu−(II) semicarbazone complex: Revisiting semicarbazone metal complexes

The structural characterization of a new pentacoordinated semicarbazone copper complex, [Cu(N,N',O-HSCPy)(N,N'-HSCPy)][ClO4]2 (1) is reported. The structure of 1 was compared to the hexacoordinated complex, [Cu(N,N',O-HSCPy)2][ClO4]2⋅H2O (2), which was already published, to shed some light on the formation of both forms. Energetic data of Cu-ligand bonds showed that the absence of a Cu-O bond in cation 1 does not significantly change the total stabilization energy in the pentacoordinate cation relative to the hexacoordinate cation (less than 4%). This is because the Cu-ligand bonds have their energies redistributed into the five existing bonds of 1. Additionally, we extended the study revisiting analogous HSCPy complexes with other coordinated metals (M), with general formula [M(N,N',O-HSCPy)2][X]2⋅solvent, where M = Ni (3), Co (4), Zn (5), Fe (6), and Mn (7); X = ClO4, and solvent = H2O (3-6) or EtOH (7); and complex [Cu(N,N',O-HSCPy)2][ClO4][I3] (8) was included in this series. In general, all additional complexes showed similar behavior to that of the Cu-hexacoordinated complex (2). In this sense, was possible to observe that the energies of the bonds M-O and M-N have strong linear correlation in the three groups: M-O3′//M-O3, M-N1′//M-N1, and M-N2′//M-N2, for complexes 2-7 (r = 0.9766; N = 18). Also, a strong correlation between stabilization energy data of metal-ligand and their respective bond lengths (r =0.9393; N = 47) was observed in all studied complexes (1-8). The supramolecular geometric similarity index ID was calculated comparing 2 with 1, 3-8. It was observed a high geometric similarity between 2 and 3-6 (ID < 0.95), indicating an isostructural behavior. The comparison between 2 and complexes 1,8 indicated values in the intermediate region (ID = 0.75) and close to a border region with an intermediate-to-high region of similarity (ID = 0.83), respectively. The similarity comparison between 2 and 7 had a value of 0.77, in the intermediate region of similarity, showing that the change of a water molecule for an ethanol molecule considerably affected the crystal packing.

Body condition and energy content of shore crab Carcinus maenas in a temperate coastal system: temporal variability

The body condition of the shore crabCarcinus maenasin a temperate coastal system (western Dutch Wadden Sea) was followed over 14 mo. Fulton’s condition factorK, dry weight condition and the percentage of dry weight were determined as indirect indices, while bomb calorimetry was applied to obtain the energy density and total energy, as direct biochemical measures of condition. General linear models identified sex, size and season as relevant regressors explaining observed variance in crab condition, whereas colour morphotype effect was negligible. The seasonal pattern was consistent with the natural cycling in temperature and expected food availability, but the peak in body condition differed depending on the type of measure used: energy peaked in autumn, while morphometric condition was at its highest in winter, uncovering different latencies in the response of direct and indirect indices. Concordant with higher energy investment in reproduction, body condition and energy content of non-ovigerous females were higher than those of males, and egg-bearing females always had the lowest condition values. Energy content of adult females ranged from 16.37 ± 1.30 (winter 2013) to 19.83 ± 0.54 kJ g-1ash-free dry weight (AFDW) (autumn 2013), attaining 18.77 ± 1.22 kJ g-1AFDW prior to the onset of reproduction in 2012, while maximum energy density of ovigerous females (eggs excluded) was 16.49 ± 0.64 kJ g-1AFDW. Besides low correlation between indirect and direct indices, fluctuations were more pronounced in the energetic data. Therefore, the morphometric measures seem weak surrogates to estimate energy density of these crabs.

Influence of Solar Disturbances on Galactic Cosmic Rays in the Solar Wind, Heliosheath, and Local Interstellar Medium: Advanced Composition Explorer, New Horizons, and Voyager Observations

Abstract We augment the heliospheric network of galactic cosmic ray (GCR) monitors using 2012–2017 penetrating radiation measurements from the New Horizons (NH) Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI), obtaining intensities of ≳75 MeV particles. The new, predominantly GCR observations provide critical links between the Sun and Voyager 2 and Voyager 1 (V2 and V1), in the heliosheath and local interstellar medium (LISM), respectively. We provide NH, Advanced Composition Explorer (ACE), V2, and V1 GCR observations, using them to track solar cycle variations and short-term Forbush decreases from the Sun to the LISM, and to examine the interaction that results in the surprising, previously reported V1 LISM anisotropy episodes. To investigate these episodes and the hitherto unexplained lagging of associated in situ shock features at V1, propagating disturbances seen at ACE, NH, and V2 were compared to V1. We conclude that the region where LISM magnetic field lines drape around the heliopause is likely critical for communicating solar disturbance signals upstream of the heliosheath to V1. We propose that the anisotropy-causing physical process that suppresses intensities at ∼90° pitch angles relies on GCRs escaping from a single compression in the draping region, not on GCRs trapped between two compressions. We also show that NH suprathermal and energetic particle data from PEPSSI are consistent with the interpretation that traveling shocks and corotating interaction region (CIR) remnants can be distinguished by the existence or lack of Forbush decreases, respectively, because turbulent magnetic fields at local shocks inhibit GCR transport while older CIR structures reaching the outer heliosphere do not.

Saturn's Nightside Dynamics During Cassini's F Ring and Proximal Orbits: Response to Solar Wind and Planetary Period Oscillation Modulations

AbstractWe examine the final 44 orbits of the Cassini spacecraft traversing the midnight sector of Saturn's magnetosphere to distances of ~21 Saturn radii, to investigate responses to heliospheric conditions inferred from model solar wind and Cassini galactic cosmic ray flux data. Clear storm responses to anticipated magnetospheric compressions are observed in magnetic field and energetic particle data, together with Saturn kilometric radiation (SKR), auroral hiss, and ultraviolet auroral emissions. Most compression events are associated with corotating interaction regions, producing ~2–3.5 day intervals of magnetospheric activity that are recurrent with the ~26 day solar rotation period (one or two such events per rotation), though one on the final pass is related to a nonrecurrent interplanetary shock possibly associated with an earlier X‐class solar flare. The response to compressions is modulated by the concurrent relative phasing of the northern and southern planetary period oscillation (PPO) systems, with long (&gt;1 planetary rotation) SKR low‐frequency extension (LFE) intervals associated with strong field‐aligned coupling currents being favored when the two PPO systems act together to thin and thicken the tail plasma sheet during each PPO cycle. LFE onsets/intensifications are then favored at thin plasma sheet phases most unstable to reconnection, producing energetic nightside particle injections and poleward contractions of dawn‐brightened auroras. Correspondingly, solar rotation recurrent intervals of magnetospheric quiet conditions also occur with weak energetic particle fluxes and auroral emissions, associated with extended solar wind rarefactions. Overall, the results emphasize how strongly activity in Saturn's magnetosphere is modulated by concurrent heliospheric conditions.

Generation of simultaneous H+ and He+ band EMIC waves in the nightside radiation belt

Previous studies have shown that EMIC waves occur preferentially in the afternoon sector of the magnetosphere. Here we report obliquely propagating H+ and He+ band EMIC waves detected by Van Allen Probe B in the region of MLT=22.7–23.5 during the June 20, 2013 substorm. Using the correlated energetic proton data, we present continuous calculations on EMIC wave growth rates along the inward orbit in the region L=5.5−4.2. The modeled growth rate shows remarkable agreement with the observed double band EMIC waves in both temporal and spatial evolutions. The current results demonstrate that H+ and He+ band EMIC waves can be simultaneously excited in the midnight sector under appropriate conditions.

Statistical Study of Oxygen Ions Abundance and Spatial Distribution in the Dayside Magnetopause Boundary Layer: MMS Observations

AbstractUsing energetic ion composition data at the dayside magnetopause measured by Magnetospheric Multiscale (MMS) satellites, we study the responses of H+, O+ density (1–40 keV), and their ratio to geomagnetic activity and solar wind conditions; their spatial distributions in the XYGSM plane for different ranges of the above parameters are presented as well. The dependencies of the H+ and O+ fluxes spatial distributions on different energy ranges are also investigated. Statistical results show that the dependencies of the H+ density on SYM‐H index, IMF By, and IMF Bz are weak, while the O+ density and its abundance (O+/H+) vary with SYM‐H index and solar wind dynamic pressure exponentially. The IMF directions not only affect the O+ density and its abundance but also play a major role in their spatial distributions. The O+ density shows duskside asymmetry under southward IMF with positive IMF By and shows dawnside asymmetry under northward IMF with negative IMF By. The influence of the dawn‐dusk IMF direction on dawn‐dusk asymmetry is significant. The positive and negative IMF By can strengthen the O+ duskside asymmetry and dawnside asymmetry when the IMF is southward and northward, respectively. Otherwise, as particle energy enhances from ~10 to ~35 keV, the H+ fluxes concentrate more on the duskside magnetopause boundary layer while the O+ fluxes dawn‐dusk asymmetry shows minor difference. This suggests that the H+ and O+ at energies below 40 keV experience different processes when they are transported to the dayside magnetopause boundary layer.

Cis- and trans-2,5,7,9-Tetranitro-2,5,7,9-tetraazabicyclo[4,3,0]nonan-8-one and Some of its Isomers-A DFT Treatise

Some geometrical isomers of tetranitro-tetraazabicyclonanones (the titled compounds) and some of their constitutional isomers are investigated quantum chemically at the level of B3LYP/6-311++G(d,p). The constitutional isomers differ from the title compounds by the position of the carbonyl group. All the structures are nitramines (actually nitramides of organic sense). The constitutional isomers considered are capable of exhibiting proton tautomerism (keto-enol type). The tautomers have also been subjected to density functional treatment at the same level of calculation. For all the structures various electronic, energetic and spectral data have been collected and discussed.

Food web transfer of plastics to an apex riverine predator.

As a rapidly accelerating expression of global change, plastics now occur extensively in freshwater ecosystems, yet there is barely any evidence of their transfer through food webs. Following previous observations that plastics occur widely in their prey, we used a field study of free-living Eurasian dippers (Cinclus cinclus), to test the hypotheses that (1) plastics are transferred from prey to predators in rivers, (2) plastics contained in prey are transferred by adults to altricial offspring during provisioning and (3) plastic concentrations in faecal and regurgitated pellets from dippers increase with urbanization. Plastic occurred in 50% of regurgitates (n=74) and 45% of faecal samples (n=92) collected non-invasively from adult and nestling dippers at 15 sites across South Wales (UK). Over 95% of particles were fibres, and concentrations in samples increased with urban land cover. Fourier transform infrared spectroscopy identified multiple polymers, including polyester, polypropylene, polyvinyl chloride and vinyl chloride copolymers. Although characterized by uncertainty, steady-state models using energetic data along with plastic concentration in prey and excreta suggest that around 200 plastic particles are ingested daily by dippers, but also excreted at rates that suggest transitory throughput. As some of the first evidence revealing that plastic is now being transferred through freshwater food webs, and between adult passerines and their offspring, these data emphasize the need to appraise the potential ecotoxicological consequences of increasing plastic pollution.

Mixed Langmuir Monolayers of C18 Fatty Acids: Effect of Degree of Saturation

The degree of unsaturation of hydrocarbon chains in the lipid diversity of biological membrane will greatly influence the membrane protein function. Lipid-lipid interactions in the membrane domain are crucial in the development of novel liposomal nanocarrier as the stability and function of liposomes are important points to be considered. The embedded therapeutic proteins are dependent on lipid membrane composition and their physical properties. In this study, we elucidated lipid-lipid interactions in the biological membrane domain with energetic quantitative data by mixing any two C18 fatty acids namely, stearic acid (SA), oleic acid (L1), linoleic acid (L2), and linolenic acid (L3) in Langmuir-Blodgett trough with water subphase. In general, SA has a saturated hydrocarbon chain; meanwhile, L1, L2 and L3 have increasing degree of unsaturation in their respective hydrocarbon chain. The tail-to-tail interactions were studied by the combinations of SA/L1, SA/L2, SA/L3, L1/L2, L1/L3 and L2/L3 at various mole ratios ranging from 9:1, 8:2, 7:3 ... to 1:9. Among the mixtures of C18 fatty acids, L2/L3 is considered as the energetically stable at the optimum amount of XL2 and XL3 = 0.5 respectively, at all discrete surface pressure.

The Interactive Influence of Climate and Energetic Factors on Human Nasal Morphology

Cold‐dry environments require considerable transfers of heat and moisture from the respiratory tract to inspired air in order to prevent thermal damage and desiccation of the lungs. Accordingly, humans indigenous to cold‐dry environments typically exhibit narrow nasal passages, as these enhance intranasal air‐conditioning by increasing contact between respired air and the heat/moisture‐rich nasal mucosa. Yet, cold‐dry environments are also metabolically expensive due to thermoregulatory demands, requiring greater oxygen intake than in tropical environments. Thus, humans from colder environments are also predicted to possess larger nasal passages (i.e., cross‐sectional areas) in order to transmit larger volumes of air during each breath. Still, despite substantial evidence that both climate and metabolism likely influence nasal size and shape, virtually no research has investigated the interplay of these two factors on nasal anatomy. Here it is hypothesized that climate‐mediated nasal narrowing may necessitate a compensatory increase in nasal height to ensure the airways remain large enough to transmit a metabolically adequate volume of oxygen. To test this, we collected 17 linear measurements from the nasal skeleton of 119 modern humans from 10 climatically diverse geographic areas (Arctic Circle, Europe, Iran, Australia, North Africa, Khoisan, South African Bantu, East Africa, West Africa, Papua New Guinea). Measurements of associated postcranial elements were then used to estimate body mass and basal metabolic rate (BMR) for each individual. Climatic data (i.e., monthly air temperature and absolute humidity) were similarly collected for the geographic provenance of each individual. These morphological, energetic, and climatic data were subsequently employed in multivariate analyses to assess potential interactive influences of climate and metabolism on nasal morphology. Our results indicate that most measurements of nasal complex breadth are significantly correlated with climate (all r‐values &gt;0.45, all p‐values &lt;0.009), but not BMR. Conversely, nasal height is more strongly correlated with BMR (r=0.47, p=0.02) than climate. Additionally, nasal passage cross‐sectional area demonstrates a positive association with BMR (r=0.74, p=0.0007), while passage cross‐sectional shape exhibits a significant relationship with climate (r=0.52, p=0.0017) with taller/narrower airways found in colder‐drier environments. Our results support assertions that nasal narrowing in colder climates necessitates a concomitant increase in nasal height to maintain an overall airway size capable of meeting energetic demands for oxygen intake. Moreover, these patterns of nasal morphology appear consistent with well‐established ecogeographic distributions in human body size/shape attributed to Bergmann’s and Allen’s Rules. Thus, future research employing larger and more diverse samples appears poised to provide far‐reaching insights regarding climatic adaptation during human evolution.

Prediction of Rate Coefficients for the H2CO + OH → HCO + H2O Reaction at Combustion, Atmospheric and Interstellar Medium Conditions.

Despite the relevance of the H2CO + OH → HCO + H2O reaction for combustion, atmospheric, and interstellar medium conditions, a large discrepancy on energetic and kinetic data for this reaction is still observed in the previous literature. In this work, this hydrogen abstraction reaction has been investigated at the CCSD(T)/CBS level of theory, suggesting that both the prebarrier complex and saddle point are stabilized in relation to the reactants by 3.31 and 1.35 kcal mol-1, respectively. Moreover, from the Gibbs free energy profile of the reaction coordinate, it has been verified that the formation of the prebarrier complex is endergonic, for temperatures above 550 K. Hence, for temperatures lower than 550 K, the reaction is described by a mechanism consisting of three elementary steps, while for higher temperatures it can be assumed to be an elementary reaction. Finally, the prediction of rate coefficients suggests that unified statistical rate theory best applies to the low temperature regime, while canonical variational rate coefficients better fit experimental data at the high temperature regime.

Energetic Map Data Imputation: A Machine Learning Approach

Despite a rapid increase of public interest for electric mobility, several factors still impede Battery Electric Vehicles’ (BEVs) acceptance. These factors include their limited range and inconvenient charging. For mitigating these limitations to users, certain BEV-specific services are required. Therefore, such services provide a reliable range prediction and routing, including charging-stop planning. The basis of these services is a precise and reliable Energy Demand (ED) prediction. For that matter, aggregated fleet-vehicle data combined with map-specific data (e.g., road slope) form an energetic map, which can serve for precise ED predictions. However, data coverage is paramount for these predictions, more specifically regarding gapless energetic maps. This work aims to eliminate the energetic map’s gaps using two Machine Learning (ML) approaches: regression and classification. The proposed ML solution builds upon the synergy between map-information and crowdsourced driving profiles of 4.6 million kilometres of training and test traces. For evaluation, two test-scenarios capture the models’ performance for the analysed problem in two perspectives. First, we evaluate our ML models, followed by the problem-specific energetic evaluation perspective for better interpretability. From the latter, the results indicate energetic map data imputation performs promisingly better when using the regression instead of the classification model.

Toward Rational Understandings of α-C-H Functionalization: Energetic Studies of Representative Tertiary Amines.

SummaryFunctionalization of α-C–H bonds of tertiary amines to build various α-C–X bonds has become a mainstream in synthetic chemistry nowadays. However, due to lack of fundamental knowledge on α-C–H bond strength as an energetic guideline, rational exploration of new synthetic methodologies remains a far-reaching anticipation. Herein, we report a unique hydricity-based approach to establish the first integrated energetic scale covering both the homolytic and heterolytic energies of α-C–H bonds for 45 representative tertiary amines and their radical cations. As showcased from the studies on tetrahydroisoquinolines (THIQs) by virtue of their thermodynamic criteria, the feasibility and mechanisms of THIQ oxidation were deduced, which, indeed, were found to correspond well with experimental observations. This integrated scale provides a good example to relate bond energetics with mechanisms and thermodynamic reactivity of amine α-C–H functionalization and hence, may be referenced for analyzing similar structure-property problems for various substrates.

Buckling of blue phosphorus nanotubes under axial compression: Insights from molecular dynamics simulations

We report on mechanical properties of blue phosphorus nanotubes (BluePNTs) from systematic molecular dynamics simulations, adopting a Stillinger-Weber potential with parameters determined by fitting to energetic and structural data from first-principles calculations. Our results corroborate the previously reported bending poison effect and size-dependent buckling behaviors. Under axial compression, current simulations predict a shell-to-column buckling mode transition for BluePNTs with increasing aspect ratios; further compression of BluePNTs with large aspect ratios results in a column-to-shell buckling mode transition. Associated critical buckling strains can be described by the continuum mechanics theory. We also simulated buckling behavior of black phosphorus nanotubes (BlackPNTs) and found that the buckling modes of BluePNTs exhibit much less chirality dependence compared to BlackPNTs, stemming from subtle structural differences between these two closely related yet distinct systems. The present results offer insights into key structural and mechanical properties of BluePNTs for fundamental understanding and potential applications of this relatively new member of the large and diverse nanotube family of materials.

Composite Methods and DFT Investigations of the Structures, Vibrational Frequencies and Energies of SF5OOX (X=H, F and Cl) and their Anions

AbstractA complete characterization of the vibrational modes has been performed for neutral and anionic pentafluorosulfur peroxides SF5OOX (X=H, F, and Cl) structures using density functional theory (DFT). The adiabatic electron affinity, bond dissociation energy and heat of formation of neutral pentafluorosulfur peroxides molecules were calculated using several Gn methods, starting from geometries optimized with B3LYP, M06‐2X and MP2 levels of theory. The most accurate enthalpies at 298 K for SF5OOH, SF5OOF, and SF5OOCl are obtained with the G4 level of theory and were used as a reference. S−F and S−Cl bonds present low energy of dissociation compared to the S−H bond. This makes possible a dissociative electron attachment (DEA) of the S−X bond (with X=F, Cl) represented by the SF5OO−X + e‐ → SF5OO− + X− reaction, while a S−H dissociation presents a low probability. This work provides crucial energetic data to improve the chemical information and characterization of these structures previously obtained through experimental studies.

Protonation of Propene on Silica-Grafted Hydroxylated Molybdenum and Tungsten Oxide Metathesis Catalysts: A DFT Study

Theoretical assessment of the protonation reaction in the activation of propene on hydroxylated Mo(VI) and W(VI) metathesis catalysts is presented in this paper using the density functional theory calculations and five support clusters varying from simple SiO4H3 clusters to a large Si4O13H9 cluster. The bond distances and thermochemical data were similar for most of the clusters. The formation of isopropoxide was more favorable than a propoxide counterpart bonded via the primary carbon atom, with the Gibbs free energies of –3.73 and –7.78 kcal/mol, respectively, for the W catalyst. Overall, the 1T cluster models with optimized H atoms or an all-relaxed alternative would be considered appropriate replacements for a larger 4T cluster model saturated with OH groups and optimized terminal hydrogen atoms. The largest deviations in the energetic data were observed between the protonated structures formed on the two larger clusters saturated with either OH or H groups.

A possible explanation for the enhancement of energetic particles downstream of the heliospheric termination shock

Voyager 2 observations of the energetic particle “time-intensity” profiles from ~1.8 to ~40 MeV show that the flux peaks downstream of the heliospheric termination shock (HTS), which is inconsistent with the predictions of classical diffusive shock acceleration (DSA). Previous studies suggest that shocks are effective in generating downstream magnetic flux ropes, islands or plasmoids. These dynamically interacting small-scale structures can accelerate charged particles statistically through reconnection-related processes. We present a preliminary study of the magnetic field and plasma properties together with the energetic particle data during the V2 crossing of the HTS. We apply a local stochastic acceleration model associated with solar wind magnetic island dynamics to explain the unusual behavior of energetic particles observed in the vicinity of the HTS. An analytic solution for the particle velocity distribution function derived from the Zank et al. statistical transport theory is used to fit the observed particle flux amplification downstream of the HTS. The results show that stochastic acceleration by interacting magnetic islands can successfully predict the observed (i) peaking of particle intensities behind the HTS, instead of at the shock front; (ii) increasing of the particle flux amplification factor with increasing particle energy; and (iii) increase in distance between the particle intensity peak and the HTS with increasing particle energy; This study illustrates the possibility of local acceleration in the inner heliosheath due to the dynamical interaction of magnetic islands.