gebhart/patrepeval huggingface dataset:
Production of mixed carbonate phases using ammonium carbonate-metal acetate reactions (2012)

Materials such as bone, nacre, and fish scales have unique structures that give the material strength as well as ductility. The ultimate goal of our research is to develop new composite materials that have improved strength and ductility compared to conventional materials. The US Army Engineer Research and Development Center is incorporating these design principles to develop hierarchical materials for structural applications. In the present study, the mineralogy and morphology of calcium-containing carbonates precipitated by reacting (NH4) 2 CO 3 with mixed Ca, Sr, Mg, and Mn-acetates was investigated. As the proportion of the non-Ca component increased, the products shifted toward double carbonates and mixtures of double carbonates with single carbonates. Characterization by scanning electron microscopy and X-ray diffraction to determine crystal sizes, morphology, and structure of precipitated phases indicated a potential for re-crystallizing the products to form new composite materials. Ongoing research efforts are focused on using information obtained in the present study to develop composites by hydrothermal recrystallization of metastable phases.
Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy (2013)

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Peter McIntyre, Saeed Assadi, Karie Badgley, William Baker, Justin Comeaux, James Gerity, Joshua Kellams, Al McInturff, Nathaniel Pogue, Supathorn Phongikaroon, Akhdiyor Sattarov, Michael Simpson, Elizabeth Sooby, Pavel Tsvetkov; Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy. AIP Conf. Proc. 19 April 2013; 1525 (1): 636–642. https://doi.org/10.1063/1.4802405 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search
Performance comparison between MC/DS-CDMA and MC-CDMA for reverse link broadband packet wireless access (2003)

This paper compares the radio link capacity between multi-carrier/DS-CDMA (MC/DS-CDMA) and multi-carrier CDMA (MC-CDMA) for reverse-link broadband packet wireless access, taking into consideration all major subject factors: the asynchronous signal reception at the receiver; the path timing or symbol timing detection; and channel estimation error. Simulation results show that, although the influence of the asynchronous signal reception on the packet error rate (PER) performance in MC-CDMA is slight, the degradation caused by the channel estimation error in MC-CDMA is severe compared to that caused by the path timing detection error in MC/DS-CDMA. Consequently, the required average received signal energy per bit-to-background noise power spectrum density ratio (E/sub b//N/sub 0/) at the average PER of 10/sup -2/ in MC/DS-CDMA is reduced by approximately 4.5 dB compared to that in MC-CDMA assuming a 12-path exponential decayed Rayleigh fading channel. Furthermore, the number of accommodated users in MC/DS-CDMA is 2.5 fold greater than that in MC-CDMA employing two-branch antenna diversity reception. Therefore, we conclude that MC/DS-CDMA is more appropriate than MC-CDMA for the reverse link broadband packet wireless access, along with its advantageous features such as an inherently much lower peak-to-average power ratio (PAPR) compared to MC-CDMA, which accompanies a high PAPR causing an Increase in the back-off of the power amplifier.
Recombination in Polymer:Fullerene Solar Cells with Open‐Circuit Voltages Approaching and Exceeding 1.0 V (2012)

Abstract Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open‐circuit voltages ( V oc ) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc ’s above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage‐dependent, steady state and time‐resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of –0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V oc values above 1.0 V and that non‐fullerene acceptor materials with large optical gaps (&gt;1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V oc exceeding 1.0 V.
Lamb dip studies of the nuclear quadrupole coupling and dipole moment in an excited vibrational state of NH2D (1976)

The hyperfine structure of two transitions in the ν2=0→1 vibrational band of the asymmetric rotor NH2D is resolved. These spectra represent the first direct observation of 14N nuclear quadrupole splittings in the optical region. The transitions were observed using Lamb dip spectroscopy in which a Stark field is used to tune the spectral components through resonance with a CO2 laser. Splittings of less than 1 MHz are resolved, and the nuclear quadrupole coupling constants in the excited vibrational state are determined to be χaa=2.52±0.24, χbb=1.46±0.36, χcc=−3.98±0.29 MHz. In addition, we find μc=1.09±0.04 D for the excited state permanent dipole moment. These values differ significantly from the ground state values, and some discussion of their physical implications is presented.
Analytical Model and Study of Continuous Parallel Plate Waveguide Lens-like Multiple-Beam Antennas (2018)

An analytical model based on geometrical optics is proposed to design and analyze continuous parallel plate waveguide (PPW) lens-like antennas. The proposed design is based on a transversal PPW section working as a lens-like beamformer. By simplifying the propagation inside this transversal section, a bifocal constrained lens model is first defined; it provides a relevant starting point to design the proposed beamformer. A refined model based on ray tracing and with an enhanced performance prediction is achieved by accounting the wave propagation inside the transversal cavity. The numerical analysis of phase aberrations and radiation demonstrate the performance of the proposed beamformer. The results of the ray-tracing model are in a very good agreement with the corresponding full-wave model, while providing a significant reduction in the computational effort, making the proposed model more suitable for advanced optimization processes.
System-environment correlations in qubit initialization and control (2019)

This paper presents numerical results on the coupling between qubits and a low-temperature bath. The results show that there exist a strong coupling that gives rise to Lamb shift and bath entanglement and uncover a trade-off between speed and accuracy. However, this does not pose an issue for the execution of quantum gates and these can be modeled using the standard, weak-coupling approach
Comparison of simulated parallel transmit body arrays at 3 T using excitation uniformity, global SAR, local SAR, and power efficiency metrics (2014)

PTx coils can simultaneously improve the excitation uniformity and reduce SAR compared to a birdcage coil when SAR metrics are explicitly constrained in the pulse design.
IRIM - Indexation et Recherche d'Information Multimedia GDR-ISIS (2012)

The IRIM group is a consortium of French teams working on Multimedia Indexing and Retrieval. This paper describes its participation to the TRECVID 2012 semantic indexing and instance search tasks. For the semantic indexing task, our approach uses a six-stages
processing pipelines for computing scores for the likelihood of a video shot to contain a target concept. These scores are then used for producing a ranked list of images or shots that are the most likely to contain the target concept. The pipeline is composed of the following steps: descriptor extraction, descriptor optimization, classification, fusion of descriptor variants, higher-level fusion, and re-ranking. We evaluated a number of different descriptors and tried dierent fusion strategies. The best IRIM run has a Mean Inferred Average Precision of 0.2378, which ranked us 4th out of 16 participants.
For the instance search task, our approach uses two steps. First individual methods of participants are used to compute similrity between an example image of instance and keyframes of a video clip. Then a two-step fusion method is used to combine these individual results and obtain a score for the likelihood of an instance to appear in a video clip. These scores are used to obtain a ranked list of clips the most likely to contain the queried instance. The best IRIM run has a MAP of 0.1192, which ranked us 29th on 79 fully automatic runs.
High-speed multispectral videography with a periscope array in a spectral shaper (2014)

We present a simple method for continuous snapshot multispectral imaging or multispectral videography that achieves high-speed spectral video recording without the need for mechanical scanning and much computation for datacube construction. The enabling component of this method is an array of periscopes placed in a prism-based spectral shaper that spectrally separates the image without image deformation. As a proof-of-principle demonstration, we show five-color multispectral video recording in the visible range (200×200 pixels per spectral image frame) at a record high frame rate of at least 2800 frames per second. Our experimental results indicate that this method holds promise for various industrial and biomedical applications such as remote sensing, food inspection, and endoscopy.
Quantification of local strain distributions in nanoscale strained SiGe FinFET structures (2017)

Strain within nanoscale strained SiGe FinFET structures has been investigated using a combination of X-ray diffraction and transmission electron microscopy-based nanobeam diffraction (NBD) techniques to reveal the evolution of the stress state within the FinFETs. Reciprocal space maps collected using high-resolution X-ray diffraction exhibited distinct features corresponding to the SiGe fin width, pitch, and lattice deformation and were analyzed to quantify the state of stress within the fins. Although the majority of the SiGe fin volume exhibited a uniaxial stress state due to elastic relaxation of the transverse in-plane stress, NBD measurements confirmed a small interaction region near the SOI interface that is mechanically constrained by the underlying substrate. We have quantitatively characterized the evolution of the fin stress state from biaxial to uniaxial as a function of fin aspect ratio and Ge fraction and confirmed that the fins obey elastic deformation based on a model that depends on the relative difference between the equilibrium Si and SiGe lattice constants and relative fraction of in-plane stress transverse to the SiGe fins. Spatially resolved, nanobeam X-ray diffraction measurements conducted near the SiGe fin edge indicate the presence of additional elastic relaxation from a uniaxial stress state to a fully relaxed state at the fin edge. Mapping of the lattice deformation within 500 nm of this fin edge by NBD revealed large gradients, particularly at the top corner of the fin. The values of the volume averaged lattice deformation obtained by nanoXRD and NBD are qualitatively consistent. Furthermore, the modulation of strain at the fin edge obtained by quantitative analysis of the nanoXRD results agrees with the lattice deformation profile obtained by NBD.
Crack Detection for Welded Joint With Surface Coating Using Unsaturated AC Magnetic Flux Leakage (2022)

Fatigue cracks occurred in the welds of steel structure are easily propagated. Therefore, it is important to detect the fatigue cracks at an early stage. However, most of the steel structures are protected by surface coating, which requires removing and restoring the coating for the inspection. This makes the inspection time-consuming. Magnetic methods such as eddy current testing (ECT) and magnetic flux leakage (MFL) can be used without removal of surface coating. However, these magnetic methods are difficult to apply to the shape of the welds and affected by nonuniform magnetic permeability. In this study, we developed a sensor probe adapted to the shape of the welded joint using the unsaturated ac MFL (USAC-MFL), which is less affected by the nonuniform magnetic permeability. To evaluate the performance of the developed sensor probe, the welded joint samples with the surface coating and shallow cracks of which depth ranges from 1 to 5 mm were measured. The measurement results showed a strong correlation between the intensity of the MFL and the crack depth. The detection performance was evaluated using the confusion matrix and the receiver-operating characteristic (ROC) curve. The area under curves (AUCs) of the ROC curves were around 0.9. In order to maximize the true positive rate (TPR) and minimize the false negative rate, the threshold of the intensity to identify a crack was obtained using the ROC curve. As the results of evaluating the detection performance using the obtained threshold, the four metrics (accuracy, precision, recall, and specification) were all above 0.8.
Ac-side admittance calculation for modular multilevel converters (2017)

Power electronic converters may interact with the grid, thereby influencing dynamic behavior and resonances. Impedance and passivity based stability criteria are two useful methods that allow for studying the grid-converter system as a feedback system, whose behavior is determined by the ratio of grid and converter impedances. In this paper, the ac-side admittance of the modular multilevel converter is calculated using harmonic linearization and considering five specific frequency components of the converter variables. The proposed model features remarkable accuracy, verified through simulations, and insight into the influence of converter and control parameters on the admittance frequency characteristics, which is useful for understanding grid-converter interaction and designing the system.
Pulsed organometallic beam epitaxy of complex oxide films (1991)

We report the results of a pulsed organometallic beam epitaxy (POMBE) process for growing complex oxide films at low background gas pressure (10−4–10−2 Torr) and low substrate temperature (600–680 °C) using organometallic precursors in an oxygen plasma environment. Our results show that POMBE can extend the capability of organometallic chemical vapor deposition to growing complex oxide films with high precision both in composition and structure without the need for post-deposition oxidation and heat treatments. The growth of phase-pure, highly oriented Y-Ba-Cu-O superconducting oxide films {[Tc (R=0)=90.5 K] and Jc (77 K, 50 K gauss)=1.1×105 A/cm2} is given as an example. Similar to the pulsed laser deposition process, the POMBE method has the potential for in situ processing of multilayer structures (e.g., junctions).
ChemInform Abstract: Synthesis and Pharmacological Evaluation of 1‐Isopropyl‐1,2,3,4‐tetrahydroisoquinoline Derivatives as Novel Antihypertensive Agents. (2011)

Abstract Different strategies are employed for the synthesis of 1‐isopropyl‐1,2,3,4‐tetrahydroisoquinoline derivatives such as (VII) or (X).
Tailorable Thermal Properties Through Reactive Blending Using Orthogonal Chemistries and Layer‐by‐Layer Deposition of Poly(1,3,5‐hexahydro‐1,3,5‐triazine) Networks (2016)

The ability to tune both the thermal and mechanical properties of poly(1,3,5‐hexahydro‐1,3,5‐triazine)s (PHTs) is critical to meet the increasingly stringent demands of structural materials. To this end, PHTs are modified during the process of vitrification using a reactive blending technique. Two strategies are employed: (i) the incorporation of a monomer or oligomer that contains amino end groups that are integrated into the network via hemiaminal chemistry and (ii) the incorporation of functional monomers bearing reactive end groups capable of self‐polymerization, as well as insertion by copolymerization with the PHT‐forming reagents to form mixed networks. Both strategies produce homogeneous materials, mitigating any adverse thermal properties of the parent PHT material. Here, a deposition method bringing the PHT technology platform to more diverse, economical and large‐scale applications is also introduced. A unique layer‐by‐layer spray‐coating approach of solutions containing 4,4′‐oxydianiline (ODA) and multifunctional amines obtained by conjugate addition to acrylates is developed, allowing for the preparation of large‐scale PHT‐polymer blend films. The ODA–PHT enables high strength and modulus of the final material, while incorporation of acrylates provide an economical approach to polymer blends with tremendous functional group diversity and will allow for recyclability under mild conditions.
Wireless network cloud: Architecture and system requirements (2010)

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> With the growth of the mobile communication network, from second-generation to third-generation or fourth-generation networks, technologists in the mobile industry continue to consider advanced wireless network architectures that have the potential to reduce networking costs and provide increased flexibility with respect to network features. In this paper, we propose the wireless network cloud (WNC), a wireless system architecture for a wireless access network. This system makes use of emerging cloud-computing technology and various technologies involved with wireless infrastructure, such as software radio technology and remote radio head technology. Based on open information technology architecture, the WNC provides all the necessary transmission and processing resources for a wireless access network operating in a cloud mode. Note that it is useful to separate the hardware and software for different wireless standards and various services and business models, as well as to meet the new system requirements for emerging wireless technologies, such as collaborative processing at different scales of network use. We analyze several important system challenges involving computational requirements of virtual base stations, I/O throughput, and timing networks for synchronization. Based on current information technologies, we make several suggestions with respect to future system design. </para>
Weakly supervised object detection with 2D and 3D regression neural networks (2020)

Finding automatically multiple lesions in large images is a common problem in medical image analysis. Solving this problem can be challenging if, during optimization, the automated method cannot access information about the location of the lesions nor is given single examples of the lesions. We propose a new weakly supervised detection method using neural networks, that computes attention maps revealing the locations of brain lesions. These attention maps are computed using the last feature maps of a segmentation network optimized only with global image-level labels. The proposed method can generate attention maps at full input resolution without need for interpolation during preprocessing, which allows small lesions to appear in attention maps. For comparison, we modify state-of-the-art methods to compute attention maps for weakly supervised object detection, by using a global regression objective instead of the more conventional classification objective. This regression objective optimizes the number of occurrences of the target object in an image, e.g. the number of brain lesions in a scan, or the number of digits in an image. We study the behavior of the proposed method in MNIST-based detection datasets, and evaluate it for the challenging detection of enlarged perivascular spaces - a type of brain lesion - in a dataset of 2202 3D scans with point-wise annotations in the center of all lesions in four brain regions. In MNIST-based datasets, the proposed method outperforms the other methods. In the brain dataset, the weakly supervised detection methods come close to the human intrarater agreement in each region. The proposed method reaches the best area under the curve in two out of four regions, and has the lowest number of false positive detections in all regions, while its average sensitivity over all regions is similar to that of the other best methods. The proposed method can facilitate epidemiological and clinical studies of enlarged perivascular spaces and help advance research in the etiology of enlarged perivascular spaces and in their relationship with cerebrovascular diseases.
Development and Novel Characterization of All-Solid-State Thin Film Batteries (2016)

All-solid-state batteries are looked to for their high energy density and reduced capacity fade, and are a safer alternative to the conventional liquid electrolyte batteries currently being manufactured. However, few solid electrolytes are currently known. Amorphous lithium phosphorus oxynitride (LiPON) is a well-established solid electrolyte and is currently the only viable solid-state electrolyte for thin film batteries. LiPON is stable in contact with Li metal, but exhibits a relatively low ionic conductivity (10 -6 S/cm 2 ) [1]. A variety of other solid electrolytes with higher ionic conductivities are currently being explored, such as lithium lanthanum titanate (LLTO), achieving high lattice ionic conductivity of &gt;10 -3 S/cm 2 [2]. We aim to enable LLTO as an electrolyte for thin film batteries via pulsed laser deposition. Additionally, performance of all-solid-state batteries is largely influenced by interfacial impedance and phase evolution during charge and discharge. The thin film geometry provides an ideal platform for analyzing the various electrode/electrolyte interfaces. Using novel focused ion beam and dynamic in situ transmission electron microscopy techniques, we have fabricated electrochemically active nanobatteries and observed their cycling behavior in situ . These techniques have been demonstrated on the layered lithium cobalt oxide (LCO)/LiPON interface, elucidating the mechanism of interfacial impedance which was previously unknown via ex-situ cycling experiments [3]. [1] N.J. Dudney, “Solid-state thin film rechargeable batteries,” Materials Science and Engineering: B, 116 (2005) 245-249. [2] O. Bohnke, “The fast lithium-ion conducting oxides Li 3x La 2/3 − x TiO 3 from fundamentals to application,” Solid State Ionics, 179 (2008) 9-15. [3] Z. Wang, D. Santhanagopalan, W. Zhang, F. Wang, H. Xin, K. He, J. Li, N. Dudney and Y.S. Meng, “In situ STEM/EELS Observation of Nanoscale Interfacial Phenomena in All-Solid-State Batteries,” Submitted.