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Dopant profiles near the semiconductor–oxide interface are critical for microelectronic device performance. As the incorporation of Si1−xGex into transistors continues to increase, it is necessary to understand the behavior of dopants in Si1−xGex. In this paper, the diffusion and electrical activation of phosphorus within a strained, single-crystal Si0.7Ge0.3 layer on Si during oxidation are reported. Both layers were uniformly doped, in situ, with an average phosphorus concentration of 4 × 1019 atoms/cm3. After high-temperature oxidation, secondary ion mass spectrometry measurements revealed that the bulk of the phosphorus diffuses out of only the SiGe layer and segregates at the oxidizing SiGe–SiO2 interface. Hall effect measurements corroborate the observed phosphorus loss and show that the phosphorus diffusing to the oxidizing interface is electrically inactive. Through density functional theory (DFT) calculations, it is shown that phosphorus interstitials prefer sites near the SiGe–SiO2 interface. Finally, based on a combination of experimental data and DFT calculations, we propose that the phosphorus atoms are displaced from their lattice sites by Ge interstitials that are generated during SiGe oxidation. The phosphorus atoms then migrate toward the SiGe–SiO2 interface through a novel mechanism of hopping between Ge sites as P–Ge split interstitials. Once they reach the interface, they are electrically inactive, potentially in the form of interstitial clusters or as part of the reconstructed interface or oxide. [ABSTRACT FROM AUTHOR]

The goal of inductive logic programming (ILP) is to learn a program that explains a set of examples. Until recently, most research on ILP targeted learning Prolog programs. The ILASP system instead learns answer set programs (ASP). Learning such expressive programs widens the applicability of ILP considerably; for example, enabling preference learning, learning common-sense knowledge, including defaults and exceptions, and learning non-deterministic theories. Early versions of ILASP can be considered meta-level ILP approaches, which encode a learning task as a logic program and delegate the search to an ASP solver. More recently, ILASP has shifted towards a new method, inspired by conflict-driven SAT and ASP solvers. The fundamental idea of the approach, called Conflict-driven ILP (CDILP), is to iteratively interleave the search for a hypothesis with the generation of constraints which explain why the current hypothesis does not cover a particular example. These coverage constraints allow ILASP to rule out not just the current hypothesis, but an entire class of hypotheses that do not satisfy the coverage constraint. This article formalises the CDILP approach and presents the ILASP3 and ILASP4 systems for CDILP, which are demonstrated to be more scalable than previous ILASP systems, particularly in the presence of noise. [ABSTRACT FROM AUTHOR]

Logic-based machine learning aims to learn general, interpretable knowledge in a data-efficient manner. However, labelled data must be specified in a structured logical form. To address this limitation, we propose a neural-symbolic learning framework, called Feed-Forward Neural-Symbolic Learner (FFNSL), that integrates a logic-based machine learning system capable of learning from noisy examples, with neural networks, in order to learn interpretable knowledge from labelled unstructured data. We demonstrate the generality of FFNSL on four neural-symbolic classification problems, where different pre-trained neural network models and logic-based machine learning systems are integrated to learn interpretable knowledge from sequences of images. We evaluate the robustness of our framework by using images subject to distributional shifts, for which the pre-trained neural networks may predict incorrectly and with high confidence. We analyse the impact that these shifts have on the accuracy of the learned knowledge and run-time performance, comparing FFNSL to tree-based and pure neural approaches. Our experimental results show that FFNSL outperforms the baselines by learning more accurate and interpretable knowledge with fewer examples. [ABSTRACT FROM AUTHOR]

β-Ga2O3 rectifiers fabricated on lightly doped epitaxial layers on bulk substrates were exposed to CF4 plasmas. This produced a significant decrease in Schottky barrier height relative to unexposed control diodes (0.68 eV compared to 1.22 eV) and degradation in ideality factor (2.95 versus 1.01 for the control diodes). High levels of F (>1022 cm−3) were detected in the near-surface region by Secondary Ion Mass Spectrometry. The diffusion of fluorine into the Ga2O3 was thermally activated with an activation energy of 1.24 eV. Subsequent annealing in the range 350–400 °C brought recovery of the diode characteristics and an increase in barrier height to a value larger than in the unexposed control diodes (1.36 eV). Approximately 70% of the initial F was removed from the Ga2O3 by 400 °C, with the surface outgas rate also being thermally activated with an activation energy of 1.23 eV. Very good fits to the experimental data were obtained by integrating physics of the outdiffusion mechanisms into the Florida Object Oriented Process Simulator code and assuming that the outgas rate from the surface was mediated through fluorine molecule formation. The fluorine molecule forward reaction rate had an activation energy of 1.24 eV, while the reversal rate of this reaction had an activation energy of 0.34 eV. The net carrier density in the drift region of the rectifiers decreased after CF4 exposure and annealing at 400 °C. The data are consistent with a model in which near-surface plasma-induced damage creates degraded Schottky barrier characteristics, but as the samples are annealed, this damage is removed, leaving the compensation effect of Si donors by F− ions. The barrier lowering and then enhancement are due to the interplay between surface defects and the chemical effects of the fluorine. [ABSTRACT FROM AUTHOR]

Neonates with symptomatic tetralogy of Fallot (sTOF) may undergo palliations with varying physiology, namely systemic to pulmonary artery connections (SPC) or right ventricular outflow tract interventions (RVOTI). A comparison of palliative strategies based on the physiology created is lacking. Consecutive sTOF neonates undergoing SPC or RVOTI from 2005–2017 were reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was survival with successful complete repair (CR) by 18 months. A variety of secondary outcomes were assessed including overall survival, hospitalization-related comorbidities, and interstage reinterventions. Propensity score adjustment was utilized to compare treatment strategies. The cohort included 252 SPC (surgical shunt = 226, ductus arteriosus stent = 26) and 68 RVOTI (balloon pulmonary valvuloplasty = 48, RVOT stent = 11, RVOT patch = 9) patients. Genetic syndrome (29 [42.6%] v 75 [29.8%], p = 0.04), weight < 2.5 kg (28 [41.2%] v 68 [27.0%], p = 0.023), bilateral pulmonary artery Z-score < − 2 (19 [28.0%] v 36 [14.3%], p = 0.008), and pre-intervention antegrade flow (48 [70.6%] v 104 [41.3%], p < 0.001) were more common in RVOTI. Significant center differences were noted (p < 0.001). Adjusted survival to CR by 18 months (HR = 0.87, 95% CI = 0.63–1.21, p = 0.41) and overall survival (HR = 2.08, 95% CI = 0.93–4.65, p = 0.074) were similar. RVOTI had increased interstage reintervention (HR = 2.15, 95% CI = 1.36–3.99, p = 0.001). Total anesthesia (243 [213, 277] v 328 [308, 351] minutes, p < 0.001) and cardiopulmonary bypass times (117 [103, 132] v 151 [143, 160] minutes, p < 0.001) favored RVOTI. In this multicenter comparison of physiologic palliation strategies for sTOF, survival to successful CR and overall survival were similar; however, reintervention burden was significantly higher in RVOTI. [ABSTRACT FROM AUTHOR]

Many industrial applications require finding solutions to challenging combinatorial problems. Efficient elimination of symmetric solution candidates is one of the key enablers for high-performance solving. However, existing model-based approaches for symmetry breaking are limited to problems for which a set of representative and easily solvable instances is available, which is often not the case in practical applications. This work extends the learning framework and implementation of a model-based approach for Answer Set Programming to overcome these limitations and address challenging problems, such as the Partner Units Problem. In particular, we incorporate a new conflict analysis algorithm in the Inductive Logic Programming system ILASP, redefine the learning task, and suggest a new example generation method to scale up the approach. The experiments conducted for different kinds of Partner Units Problem instances demonstrate the applicability of our approach and the computational benefits due to the first-order constraints learned. [ABSTRACT FROM AUTHOR]

We report the development of a process/device simulation platform to model superconductor electronics. The process simulator leverages the back-end modeling capabilities of Florida object-oriented process/device/reliability simulator (FLOOXS) and builds on the existing models to simulate processes specific to Josephson junction (JJ) fabrication. The device simulator uses the process generated models and computes the normal-state electrical properties of a Nb/Al-AlO/Nb JJ. It is used to predict key operational figures of merit and how they vary with changes in process models. By integrating the process and device simulation tools, this research aims to offer an environment for the simulation of JJ circuits. [ABSTRACT FROM AUTHOR]

N+ ion implantation to form resistive regions for edge termination at the anode contact periphery was used to maximize the breakdown voltage (VB) of vertical geometry β-Ga2O3 rectifiers. The design was examined via simulations using the Florida object oriented device and process Technology Computer-Aided Design (TCAD) simulator. The configuration of the implanted region was investigated with these simulations and then implemented experimentally. Significant increases of ∼200%–250% in VB were achieved for 50–1000 μm diameter rectifiers with an unbounded resistive region and an implantation depth of ∼0.5 μm. The on-state resistance and on/off ratios of the rectifiers were essentially unchanged by the addition of the implanted regions. An optimized implanted edge termination structure maximizes the breakdown voltage with no associated increase in device resistance in vertical geometry Ga2O3 rectifiers. [ABSTRACT FROM AUTHOR]

The understanding and availability of quantitative measurements of the diffusion of dopants and impurities in Ga2O3 are currently at an early stage. In this work, we summarize what is known about the diffusivity of the common donor dopants, Sn, Ge, and Si, as well as some of the deep acceptors, N, Fe, and Mg, and donors, Ir. Two commonly encountered interstitial impurities are H and F, the former through growth and processing ambients and the latter through its use in plasmas used for stripping dielectrics from Ga2O3. Both are found to have high diffusion coefficients and an effect on electrical conductivity, and H shows anisotropy in its diffusion behavior. Si, Ge, and Sn implanted into bulk β-Ga2O3 at total doses from 2 × 1013 to 2 × 1015 cm−2 and annealed at 1100 °C for 10–120 s in either O2 or N2 ambients showed a significant effect of the annealing ambient on the donor's diffusivity. In the case of O2 annealing, there was extensive redistribution of the Si, Sn, and Ge across the entire dose range, while, in sharp contrast, the use of N2 annealing suppressed this diffusion. The N2 ambient also suppressed loss of dopants to the surface, with >90% of the initial dose retained after annealing at 1100 °C for 120 s, compared to 66%–77% with O2 anneals under the same conditions. [ABSTRACT FROM AUTHOR]

By modeling the propagation of a seed layer with various crystal orientations, this study explores the influence of process variations on grain formation with the help of a physics-based process simulator. Grain boundaries allow easy diffusion of foreign atoms through the lattice, which causes Al to move inside the Nb bottom electrode layer and more interestingly, O to penetrate through the Al layer during oxidation and create a barrier with non-uniform thickness. In addition to thickness variations, the grain structure exhibited by Nb and Al can cause significant suppression of supercurrent at the boundaries depending on the degree of lattice mismatch, impurity deposition, etc. This work details the process simulation of grain boundary formation and aims to provide geometrical models that may be used in the simulation of device performance to account for process-induced variations. [ABSTRACT FROM AUTHOR]

The high breakdown voltage and low on-state resistance of Schottky rectifiers fabricated on β-Ga2O3 leads to low switching losses, making them attractive for power inverters. One of the main goals is to achieve high forward currents, requiring the fabrication of large area (>1 cm2) devices in order to keep the current density below the threshold for thermally driven failure. A problem encountered during the measurement of these larger area devices is the dependence of current spreading on the probe size, resistance, number, and geometry, which leads to lower currents than expected. We demonstrate how a multiprobe array (6 × 8 mm2) provides a means of mitigating this effect and measure a single sweep forward current up to 135 A on a 1.15 cm2 rectifier fabricated on a vertical Ga2O3 structure. Technology computer-aided design simulations using the floods code, a self-consistent partial differential equation solver, provide a systematic insight into the role of probe placement, size (40–4120 μm), number (1–5), and the sheet resistance of the metal contact on the resultant current-voltage characteristics of the rectifiers. [ABSTRACT FROM AUTHOR]

Full-dimensional variational calculations are reported for the isomerising disilyne molecule, Si2H2. Large-scale calculations using coordinates based on orthogonal satellite vectors permitted the computation of excited vibrational state energies and wavefunctions for all four isomeric forms: dibridged Si(H2)Si, monobridged Si(H)SiH, disilavinylidene H2SiSi, and trans-bent HSiSiH. Energies and wavefunctions have been determined for the lowest 2400 totally symmetric vibrational states; this set includes highly excited states above all three chemically relevant isomerisation barriers - up to about 8300 cm-1 above the (dibridged) ground state. States strongly localised in the dibridged, monobridged, and disilavinylidene regions of the potential energy surface have been found as well as many partially or fully delocalised states. For the trans-bent form, only partially localised states have been identified. Comparisons are made with similar literature calculations on the isovalent acetylene-vinylidene system HCCH/H2CC. [ABSTRACT FROM AUTHOR]

One of the key areas for implementation of high-power Ga2O3 rectifiers is the mitigation of electric field crowding at the edge of the depletion region to avoid premature breakdown. Floating metal field rings (FMRs) are a relatively simple approach for achieving this. We report simulations of the spacing (1–10 μm), width (2–15 μm), number of rings, and also the effect of biasing the rings (0–280 V) and including a field plate at the periphery of the rings on the breakdown voltage of a vertical geometry rectifier with a range of doping concentrations (5 × 1015–4 × 1016 cm−3) in the drift region. Improvements in breakdown voltage of 19%–54% relative to an unterminated rectifier are found with an optimum design of the field rings. The experimental results on rectifiers with different FMR geometries show an RON of 4.5–4.9 mΩ cm2, a turn-on voltage of 0.96–0.94 V, a high on-off ratio of >5 × 106, an ideality factor of 1.03, and a Schottky barrier height of 1.03 eV at room temperature. These devices have similar forward electrical characteristics, indicating that FMRs do not degrade the device rectifying performance. [ABSTRACT FROM AUTHOR]

General game playing (GGP) is a framework for evaluating an agent's general intelligence across a wide range of tasks. In the GGP competition, an agent is given the rules of a game (described as a logic program) that it has never seen before. The task is for the agent to play the game, thus generating game traces. The winner of the GGP competition is the agent that gets the best total score over all the games. In this paper, we invert this task: a learner is given game traces and the task is to learn the rules that could produce the traces. This problem is central to inductive general game playing (IGGP). We introduce a technique that automatically generates IGGP tasks from GGP games. We introduce an IGGP dataset which contains traces from 50 diverse games, such as Sudoku, Sokoban, and Checkers. We claim that IGGP is difficult for existing inductive logic programming (ILP) approaches. To support this claim, we evaluate existing ILP systems on our dataset. Our empirical results show that most of the games cannot be correctly learned by existing systems. The best performing system solves only 40% of the tasks perfectly. Our results suggest that IGGP poses many challenges to existing approaches. Furthermore, because we can automatically generate IGGP tasks from GGP games, our dataset will continue to grow with the GGP competition, as new games are added every year. We therefore think that the IGGP problem and dataset will be valuable for motivating and evaluating future research. [ABSTRACT FROM AUTHOR]

A general, full-dimensional computational method for the accurate calculation of rotationally and vibrationally excited states of tetra-atomic molecules is further developed. The resulting computer program may be run in serial and parallel modes and is particularly appropriate for molecules executing wide-amplitude motions and isomerizations. An application to the isomerizing acetylene/vinylidene system is presented. Large-scale calculations using a coordinate system based on orthogonal satellite vectors have been performed in six dimensions and vibrational term values and wave functions for acetylene and vinylidene states up to ≈23 000 cm-1 above the potential minimum have been determined. This has permitted the characterization of acetylene and vinylidene states at and above the isomerization barrier. These calculations employ more extensive vibrational basis sets and hence consider a much higher density of states than in any variational calculations reported hitherto for this system. Comparison of the calculated density of states with that determined empirically suggests that our calculations are the most realistic achieved for this system to date. Indeed more states have been converged than in any previous study of this system. Calculations on lower lying excited states of acetylene based on HC–CH diatom-diatom coordinates give nearly identical results to those based on orthogonal satellite vectors. Comparisons are also made with calculations based on HH–CC diatom-diatom coordinates. [ABSTRACT FROM AUTHOR]

We have investigated the electrical activation of implanted boron in silicon-on-insulator (SOI) material using Hall effect, four-point probe, and secondary ion mass spectrometry. Boron was implanted at energies ranging from 1 keV to 6.5 keV with a dose of 3×1014 cm-2 into bonded SOI wafers with surface silicon thickness ranging from 300 Å to 1600 Å. In one sample set, furnace anneals at 750 °C were performed in a nitrogen ambient for times ranging from 5 min to 48 h. A second sample consisted of isochronal furnace anneals performed from 450 °C to 1050 °C for 30 min. Significantly less activation of boron is observed in SOI at temperatures below 750 °C, regardless of the implant energy and surface silicon thickness. Between 750 °C and 900 °C, the active dose of boron in SOI is similar to that of bulk Si. As the implant energy increases, the fractional activation in thin SOI increases, due to a reduction in boron interstitial clusters (BIC) in the surface Si layer. It is concluded that an increase in the BIC population is the likely source of the low activation observed in SOI. This may be due to an increase in the interstitial supersaturation within the surface Si layer, due to the interface acting as a reflective boundary for interstitials. [ABSTRACT FROM AUTHOR]

End of range (EOR) defects are the most commonly observed defects in ultrashallow junction devices. They nucleate at the amorphous-crystalline interface upon annealing after amorphization due to ion implantation. EOR defects range from small interstitial clusters of a few atoms to {311} defects and dislocation loops. They are extrinsic defects and evolve during annealing. Li and Jones [Appl. Phys. Lett., 73, 3748 (1998)] showed that {311} defects are the source of the projected range dislocation loops. In this article, the same theory is applied to EOR dislocation loops to model the nucleation and evolution of the loops. The model is verified with experimental data and accurately represents the nucleation, growth, and Ostwald ripening stages of dislocation loop evolution. The density and the number of interstitials trapped by dislocation loops are compared with the experimental results for several annealing times and temperatures. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A general, six-dimensional computational method for the accurate calculation of rotationally and vibrationally excited states of tetra-atomic molecules is developed. The resulting program is particularly appropriate for molecules executing wide-amplitude motions and isomerizations. An application to the Ar[sub 2]HF van der Waals trimer is presented in which the HF intramolecular stretching coordinate is separated out adiabatically and is not treated explicitly. Vibrational term values up to about 100 cm[sup -1] with absolute convergence to better than 0.1 cm[sup -1] are reported. These calculations employ more extensive vibrational basis sets and hence consider a much higher density of states than hitherto. States that sample Ar-Ar-HF linear configurations and approach Ar-HF-Ar linear configurations are characterized for the first time. Results for total angular momentum J = 0 and 1 provide the first accurate calculations of rotational constants for this system. The rotational constants for the HF bending states of Ar[sub 2]HF in the ground and first vibrationally excited states of the HF monomer are in good agreement with experiment, confirming the accuracy of the potential used in this work. [ABSTRACT FROM AUTHOR]

Scaling the gate oxide thickness is one of many process development challenges facing device engineers today. Nitrogen implantation has been used to control gate oxide thickness. By varying the dose of the nitrogen implant, process engineers can have multiple gate oxide thicknesses in the same process. Although it has been observed that nitrogen retards gate oxidation kinetics, the physics of how this occurs is not yet well understood. Since the retardation in oxide growth is due to the diffusion of nitrogen and its subsequent incorporation at the silicon/silicon oxide interface, the study of the diffusion behavior of nitrogen in silicon becomes important. Further, it is also necessary to study how this diffusion behavior impacts oxide growth. Models have been developed to explore these issues. The diffusion model is based on ab initio results and is compared to experimental results at two temperatures. The oxide reduction model is based on the diffusion of nitrogen to the surface. The surface nitrogen is coupled to the surface reaction rate of silicon and oxygen to moderate oxide growth. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Studies the interdiffusion of Si/Si0.85Ge0.15/Si single quantum well structures subjected to inert- and oxidizing-ambient annealing. Extraction of diffusion coefficients; Similarity in diffusion profiles of samples processed.

Some packaging technologies of electronic devices introduce compressive biaxial stress and variable vertical stress. In unipolar MOS devices, stress variations typically only linearly affect drain current via carrier mobility. Collector currents of bipolar devices are additionally affected by variations in intrinsic carrier concentration. This leads to increased variability of key device parameters in the compressive stress regime. Reducing package-induced compressive stress, or inducing tensile stress, should improve device variability due to local stress variations. [ABSTRACT FROM AUTHOR]

The n-type dopants, Ge and Sn, were implanted into bulk (−201) β-Ga2O3 at multiple energies (60, 100, 200 keV) and total doses of ∼1014 cm−2 and annealed at 1100 °C for 10–120 s under either O2 or N2 ambients. The Ge-implanted samples showed almost complete recovery of the initial damage band under these conditions, with the disordered region decreasing from 130 to 17 nm after 1100 °C anneals. Fitting of secondary ion mass spectrometry profiles was used to obtain the diffusivity of both Ge and Sn, with values at 1100 °C of 1.05 × 10−11 cm s−1 for Ge and 2.7 × 10−13 cm s−1 for Sn for annealing under O2 ambients. Some of the dopant is lost to the surface during these anneals, with a surface outgas rate of 1–3 × 10−7 s−1. By sharp contrast, the redistribution of both dopants was almost completely suppressed during annealing in N2 ambients under the same conditions, showing the strong influence of point defects on dopant diffusivity of these implanted dopants in β-Ga2O3. [ABSTRACT FROM AUTHOR]

Dysphagia and vocal cord dysfunction are frequent complications after congenital heart surgery. Both are risk factors for aspiration, which can lead to pneumonia, progressive lung disease, and respiratory arrest. A protocol was implemented to promote early detection of aspiration in a high-risk cohort of patients. Retrospective data were collected on all patients under 120 days old who underwent the Norwood procedure, aortic arch repair, Blalock–Taussig shunt placement, or cervical cannulation for extracorporeal membrane oxygenation from 10/2012 to 05/2016 at a single institution. Patients underwent an assessment of symptoms, fiberoptic endoscopic evaluation of swallowing (FEES), and modified barium swallow (MBS) study in the postoperative period prior to initiating oral feeds. Patients with and without aspiration were compared. Of the 96 patients included in the study, one-third (33%) of patients had evidence of vocal cord dysfunction by FEES and just over half (51%) had evidence of aspiration by FEES or MBS. Most (73%) of the patients with aspiration were asymptomatic and a majority (53%) of patients with aspiration had normal vocal cord function. Aspiration is common after congenital heart surgery, and an assessment of vocal cord or swallow function in isolation may lead to underdiagnosis. A comprehensive protocol including MBS and FEES is necessary for the early detection of vocal cord dysfunction and aspiration and may prevent adverse outcomes in high-risk postoperative patients. [ABSTRACT FROM AUTHOR]

The most common n-type dopant, Si, was implanted into bulk (-201) β-Ga2O3 at total doses from 2x1013-2x1015 cm-2 and annealed at 1100 °C for 10-120 secs in either O2 or N2 ambients. Secondary Ion Mass Spectrometry profiling showed a significant effect of the annealing ambient on the Si diffusivity. In the case of O2 annealing, there was extensive redistribution of the Si across the entire dose range, while in sharp contrast, the use of N2 annealing suppressed the Si diffusion. The results are consistent with a defect-assisted process. Excellent fits to the Si profiles were obtained with the FLOOPS simulator, assuming mobile vacancy/defect concentrations as the important factor for the difference in the O2 vs N2 annealing ambients. One possibility is that for N2 anneals, more Ga vacancies are created, enabling interstitial Si to migrate onto a substitutional Ga site where it has low diffusivity. The N2 ambient also suppresses loss of Si to the surface, with >90% of the initial dose retained after annealing at 1100 °C for 120 secs, compared to 66-77% with O2 anneals under the same conditions. [ABSTRACT FROM AUTHOR]

Shoe manufacturers launch running shoes with increased (e.g., maximalists) or decreased (e.g., minimalists) midsole thickness and claim that they may prevent running injury. Previous studies tested footwear models with different midsole thicknesses on the market but the shoe construct was not strictly comparable. Therefore, in the present study, we examined the effect of midsole thickness, from 1-mm to 29-mm, in a standard test shoe prototype on the vertical loading rates, footstrike angle and temporal spatial parameters in distance runners. Fifteen male habitual rearfoot strikers were recruited from local running clubs. They were asked to run on an instrumented treadmill in shoes with different midsole thicknesses. We found significant interactions between midsole thickness with vertical loading rates (p < 0.001), footstrike angle (p = 0.013), contact time (p < 0.001), cadence (p = 0.003), and stride length (p = 0.004). Specifically, shoes with thinner midsole (1- and 5-mm) significantly increased the vertical loading rates and shortened the contact time, when compared with thicker midsole shoes (25- and 29-mm). However, we did not observe any substantial differences in the footstrike angle, cadence and stride length between other shod conditions. The present study provides biomechanical data regarding the relationship between full spectrum midsole thicknesses and running biomechanics in a group of rearfoot strikers. [ABSTRACT FROM AUTHOR]

Two potential energy surfaces for CO2–Ar are obtained by least-squares fitting to the high-resolution spectra of Van der Waals complexes and the second virial coefficients of Ar+CO2 gas mixtures. The potentials incorporate a repulsive wall based on monomer ab initio calculations and the assumption that the repulsion potential is proportional to the overlap of the monomer charge densities. The dispersion energy is represented in a two-site model, with dispersion centers located along the C–O bonds of CO2. The resulting potentials give a good representation of all the experimental data with only three or four adjustable parameters. They are quite different from previous empirical CO2–Ar potentials, which all have either a poor representation of the attractive well or a poor representation of the repulsive wall. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We have observed a microwave spectrum of the HeKr+ ion in which all of the observed levels lie within a few cm-1 of either the first or second dissociation limit. We use an ion beam technique in which HeKr+ ions, formed by electron impact, are mass analyzed. Passage of the ion beam through an electric field lens results in selective fragmentation of energy levels lying close to dissociation. Kr+ ions formed in the lens are separated from all other ions by means of an electrostatic analyzer, and are detected with an electron multiplier. Microwave radiation induces transitions which result in population transfer and produce detected changes in the electric field-induced Kr+ fragment ion current. Additional transitions have been detected by a microwave–microwave double resonance method, and we have also made extensive use of the Zeeman effects produced by small applied coaxial magnetic fields to identify the J quantum numbers of the levels involved. Coupled channel calculations of the bound states of the He...Kr+ ion are carried out, fully including all the couplings between different electronic states correlating with He+Kr+ (2P3/2 and 2P1/2). The calculations allow the spectra to be assigned to pure rotational transitions involving levels in the X, A1, and A2 states that lie within 2.5 cm-1 of the dissociation limits. Because of a systematic near degeneracy between vibrational levels in the X and A1 states, the long-range He...Kr+ ion provides a very good example of Hund’s case (e) in the form introduced by Mulliken, in which there are no projection quantum numbers onto the interatomic axis. Mulliken’s case (e) is rather different from the Rydberg case (e) described by Lefebvre–Brion, and this is the first time that Mulliken’s case (e) has been observed. The spectra allow the interaction potential for He...Kr+ to be determined accurately, for the first time, by least-squares fitting of potential parameters to the experimental... [ABSTRACT FROM AUTHOR]

We have measured and interpreted a microwave spectrum of the HeAr+ ion in which all of the observed energy levels lie within 8 cm-1 of the lowest dissociation limit, He(1S)+Ar+(2P3/2). We use an ion beam technique in which the HeAr+ ions are formed by electron impact, accelerated to kilovolt potentials, and mass-analyzed. After passage through an appropriate section of waveguide, the ions enter an electric field lens in which state-selective fragmentation occurs; the Ar+ ions produced in the lens are separated from all other ions by means of an electrostatic analyser and detected with an electron multiplier. Microwave transitions induced in the waveguide section result in population transfer which produces detected changes in the electric field-induced Ar+ fragment current. Many transitions have also been observed by a microwave–microwave double resonance technique. We have observed 68 lines spanning the frequency range 6–170 GHz; no immediately recognizable pattern is apparent. We have measured the Zeeman splitting produced by a small axial magnetic field for almost every line, which enables us to determine the values of the total angular momentum J involved in each transition, and also effective g factors for the two levels involved. We are therefore able to construct a purely experimental pattern of 37 levels lying within 8 cm-1 of the dissociation limit. The data are treated first by means of a conventional effective Hamiltonian in a case (c) basis, which allows electronic and vibrational quantum numbers to be assigned to most of the levels; the assignments are approximate, however, because very strong rotational-electronic coupling undermines the Born–Oppenheimer approximation.A more complete theoretical treatment is then presented, using the coupled-channel method in a case (e) representation to calculate the energy levels without making the Born–Oppenheimer approximation. The microwave transition frequencies and g-factors are... [ABSTRACT FROM AUTHOR]

Studies the behavior of silicon semiconductor devices that are scaled to sub-micron dimensions when exposed to stress. Degradation of device characteristics by generation and propagation of dislocations in the silicon substrate; Comparison of volume of trapped atoms in dislocation loop in nitride films versus nitride films with underlying oxide layers.

Compares transient enhanced diffusion effects between boron and phosphorus of dopants in silicon. Significant enhancement of phosphorus during damage annealing; Indications of dislocation growths; Agreement between dislocation growth saturation time and phosphorus diffusion saturation.

Studies the effects of hydrostatic pressure on dopant diffusion in silicon. Method of the study; Results and discussion; Conclusion.

Describes the point defect based modeling of low dose silicon implant damage and oxidation effects on phosphorus and boron diffusion in silicon. Comparison with experimental results for intrinsically doped material; Significance of the theory of dopant-defect pairing; Information on the dopant equations used.

Thrombosis and systemic embolization are important complications of extracorporeal membrane oxygenation (ECMO). We present a 2.5 kg neonate born at 37.4 weeks with hypoplastic left heart supported on ECMO that developed an acute, occlusive distal aortic thrombus that was emergently managed by transcatheter Angiojet® (Boston Scientific, Boston, MA) thrombectomy. The procedure successfully restored perfusion to the lower extremities with sustained result upon 1-week follow-up. This case highlights the Angiojet® thrombectomy as a treatment option for limb- or organ-threatening acute thrombus in even the most complex ECMO patients. [ABSTRACT FROM AUTHOR]

Fontan operation can be complicated by persistent chest tube output (CTO) leading to prolonged hospital length of stay (LOS). Postoperative sildenafil administration has been shown to improve clinical outcomes in selected patients after Fontan. We initiated a practice change utilizing intravenous (IV) sildenafil in early postoperative period in all patients undergoing Fontan operation with aim to decrease LOS and CTO. Nineteen patients (February 2014-May 2016) received 0.35 mg/kg sildenafil IV (three doses) followed by enteral, 1 mg/kg every eight hours until hospital discharge. Clinical outcomes were compared to 84 pre-protocol controls. Vital signs were recorded after second sildenafil dose. Demographics were similar between groups. Sildenafil group had longer median LOS [9 (7, 11) vs. 13 (8, 25) days, p = 0.016]. CTO days were longer [6 (5, 8) vs. 8 (6, 13) days, p = 0.011]. Sildenafil group had longer mechanical ventilation [6.9 (3.5, 11.1) vs. 4 (2, 7) h, p = 0.045] and longer oxygen therapy [99 (52, 225) vs. 14.5 (14, 56) h, p = 0.001]. There was a trend towards more albumin 5% resuscitation in first 24 h [17 (1, 30) vs. 21 (10, 40) ml/kg, p = 0.069]. There was no difference in inotrope score at 24 h, maximum lactate, or fluid balance. Readmission rates were similar. There was no mortality. IV sildenafil was well tolerated, and no doses were held. Routine early administration of sildenafil after Fontan operation is not associated with an improvement in any measured clinical outcome, including postoperative CTO, LOS, colloid administration, or duration of mechanical ventilation. [ABSTRACT FROM AUTHOR]

The interdiffusion of a Si/Si[sub 0.85]Ge[sub 0.15]/Si single quantum well heterostructure subjected to thermal annealing in a nitriding ambient was investigated as a function of anneal temperature and time. Nitridation of the silicon surface alters equilibrium vacancy point defect populations throughout the structure, which allows the determination of the point defect species important in interdiffusion. Diffusion coefficients of Ge after nitridation of ∼1x10[sup -14] cm[sup 2]/s for 1100 °C and ∼1x10[sup -13] cm[sup 2]/s for 1200 °C were extracted. The extent of diffusion in a nitriding ambient was much less than in an inert ambient, which indicates minimal vacancy contribution to interdiffusion. This is in contrast to results from previously published studies performed in an oxidizing ambient. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]