gebhart/patrepeval huggingface dataset:
Space Active Optics: toward optimized correcting mirrors for future large spaceborne observatories (2011)

Wave-front correction in optical instruments is often needed, either to compensate Optical Path Differences, off-axis aberrations or mirrors deformations. Active optics techniques are developed to allow efficient corrections with deformable mirrors. In this paper, we will present the conception of particular deformation systems which could be used in space telescopes and instruments in order to improve their performances while allowing relaxing specifications on the global system stability. A first section will be dedicated to the design and performance analysis of an active mirror specifically designed to compensate for aberrations that might appear in future 3m-class space telescopes, due to lightweight primary mirrors, thermal variations or weightless conditions. A second section will be dedicated to a brand new design of active mirror, able to compensate for given combinations of aberrations with a single actuator. If the aberrations to be corrected in an instrument and their evolutions are known in advance, an optimal system geometry can be determined thanks to the elasticity theory and Finite Element Analysis.
Synthetic approaches to adriamycin. Degradation of daunorubicin to nonasymmetric tetracyclic ketone and refunctionalization of the A-ring to adriamycin (1976)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthetic approaches to adriamycin. Degradation of daunorubicin to nonasymmetric tetracyclic ketone and refunctionalization of the A-ring to adriamycinThomas H. Smith, Allan N. Fujiwara, David W. Henry, and William W. LeeCite this: J. Am. Chem. Soc. 1976, 98, 7, 1969–1971Publication Date (Print):March 1, 1976Publication History Published online1 May 2002Published inissue 1 March 1976https://pubs.acs.org/doi/10.1021/ja00423a057https://doi.org/10.1021/ja00423a057research-articleACS PublicationsRequest reuse permissionsArticle Views201Altmetric-Citations38LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Improving Mechanical Strength and Surface Uniformity to Prepare High Quality Thinned 4H-SiC Epitaxial Wafer Using Si-Vapor Etching Technology (2017)

As a new thinning and surface planarizing process of Silicon Carbide (SiC) wafer, we propose the completely thermal-chemical etching process; Si-vapor etching (Si-VE) technology. In this work, the effects of mechanical strength and surface step-terrace structure by Si-VE are investigated on the 4° off-axis 4H-SiC (0001) Si-face substrates. The indentation hardness of Si-VE surface is superior to the conventional chemo-mechanical polishing (CMP) surface even after epitaxial growth. The transverse strength of thinned Si-VE substrate is also superior to the conventional mechanically ground substrate. The surface step-terrace structures are observed by the low energy electron channeling contrast (LE-ECC) imaging technique. The latent scratch causes bunched step lines (BSLs) with various inhomogeneous step morphologies only on the CMP surface.
Variable semiconductor all-optical buffer (2002)

A compact variable all-optical buffer using semiconductor quantum dot structures is proposed. The buffering effect is achieved by slowing down the optical signal using an external control light source to vary the dispersion characteristic of the medium. The theoretical model shows that a slow-down factor of more than 104 with negligible group velocity dispersion is achievable.
Efficient Sphere Detector Algorithm for Massive MIMO Using GPU Hardware Accelerator (2016)

To further enhance the capacity of next generation wireless communication systems, massive multiple-input multiple-output (MIMO) has recently appeared as a necessary enabling technology to achieve high performance signal processing for large-scale multiple antennas. However, massive MIMO systems inevitably generate signal processing overheads, which translate into ever-increasing rate of complexity, and therefore, such systems may not maintain the inherent real-time requirement of wireless systems. We redesign the nonlinear sphere decoder method to increase the performance of the system, cast most memory-bound computations into compute-bound operations to reduce the overall complexity, and maintain the real-time processing thanks to the graphics processing unit (GPU) computational power. We show a comprehensive complexity and performance analysis on an unprecedented MIMO system scale, which can ease the design phase toward simulating future massive MIMO wireless systems.
Responsive Pore Size Properties of Composite NF Membranes Based on PVDF Graft Copolymers (2009)

Abstract Uncharged nanofiltration (NF) membranes can potentially perform size-based separations of small molecules. Thin film composite (TFC) membranes, prepared by coating a porous support membrane with a thin layer of poly(vinylidene fluoride)-graft-poly(oxyethylene) methacrylate (PVDF-g-POEM), were shown previously to have such capability, as well as exceptional fouling resistance and high pure water permeability (Macromolecules 2004, 37, 7663–7668). The selectivity and permeability of these membranes arises from the microphase separation of the PVDF backbone and polyethylene oxide (PEO) side chains into bicontinuous hydrophobic and hydrophilic phases, the PVDF domains providing mechanical integrity, and the PEO domains acting as “nanochannels” whose dimensions control molecular transport through the membrane. This study explores the influence of process and solution parameters on the permeability and selectivity of PVDF-g-POEM TFC NF membranes. By controlling the degree of swelling of the hydrated PEO chains filling the channels, the effective pore size of the membrane is shown to be tunable. Membrane permeability to water and to organic dye molecules of approximately 1 nm diameter is found to increase when the solvent quality of the feed for the PEO chains is reduced by raising the temperature, pressure, or ionic strength, or by the addition of ethanol. This property holds promise for applications in the biochemical, pharmaceutical, and food industries for low-cost, high-throughput fractionation of molecules.
Synthesis of fluorinated catharanthine analogues and investigation of their biomimetic coupling with vindoline (2013)

The syntheses of 20,20-difluorocatharanthine and congeners, starting from the naturally occurring catharanthine, are reported. The fluorinated catharanthine analogues were investigated as potential precursors to dimeric Vinca alkaloids of the vinflunine family. However, the biomimetic coupling of the fluorinated catharanthine derivatives with vindoline led to unexpected alkaloid structures, the formation of which was rationalized.
Generational Association Studies of Dopaminergic Genes in Reward Deficiency Syndrome (RDS) Subjects: Selecting Appropriate Phenotypes for Reward Dependence Behaviors (2011)

Although our sample size was limited, and linkage analysis is necessary, the results support the putative role of dopaminergic polymorphisms in RDS behaviors. This study shows the importance of a nonspecific RDS phenotype and informs an understanding of how evaluating single subset behaviors of RDS may lead to spurious results. Utilization of a nonspecific "reward" phenotype may be a paradigm shift in future association and linkage studies involving dopaminergic polymorphisms and other neurotransmitter gene candidates.
Fiber-optic gyroscope with polarization-holding fiber (1983)

A fiber gyroscope is reported that uses polarization-holding fiber in the coil, the phase modulator, and the coupler. The random-drift coefficient, calculated from rms noise levels, was 8.10(-4) deg/ radicalh, within a factor of 2 of an experimentally determined quantum and thermal limit. White-noise behavior was observed for integration time constants from 1 to 40 sec. Device characteristics and performance are presented.
ReflecTech® Mirror Film Attributes and Durability for CSP Applications (2009)

Reflectors are an essential part of parabolic trough solar electric and other concentrating solar power (CSP) systems. Reflectors in CSP systems require a high reflectance over the solar wavelength spectrum and they must be durable to outdoor exposure and resist all forms of degradation over time. All utility-scale CSP systems installed to date use glass reflectors. Glass mirrors have maintained their reflectance very well in CSP environments, but they are susceptible to wind-related breakage and are expensive to transport and install. Alternative lower-cost reflectors are needed to reduce the cost of CSP systems [1]. ReflecTech® Mirror Film is a highly reflective polymer-based film co-developed with the National Renewable Energy Laboratory (NREL) for concentrating solar energy applications. The attributes of ReflecTech® Mirror Film and test results for weatherability are described herein. This paper discusses field and lab test results and properties of ReflecTech® Mirror Film, specifically: 1. Stability under ultraviolet (UV) light through accelerated testing and outdoor real-time testing. 2. Mechanical stability and resistance to moisture through water immersion tests for delamination and “tunneling”. 3. Mechanical resistance to high wind events common in utility-scale concentrating solar power applications. 4. Lighter weight and resistance to breakage that reduces transportation and installation costs, and allows greater design flexibility of concentrator geometries. 5. Lower initial cost compared with curved glass mirrors. To test for weatherability, reflector samples were subjected to controlled conditions more extreme than actual outdoor environments. NREL maintains a world-class testing capability for solar reflectors that includes a Solar Simulator (SS), QUV (an accelerated exposure chamber manufactured by Q-Lab Corp. that subjects materials to alternating cycles of light and condensation at elevated temperatures), and several WeatherOmeter® (WOM) exposure chambers that allow accelerated testing of reflector samples. In addition, samples of ReflecTech® Mirror Film have been subjected to ACUVEX® accelerated outdoor weathering tests (natural sunlight in Phoenix, AZ, concentrated 7 to 8 times with a Fresnel-reflector while the samples are cooled with a fan to near ambient conditions and sprayed with de-ionized water 8 min per natural sun hour). Immersion tests were also performed to test the resistance of ReflecTech® Mirror Film to extreme moisture. Test results compared ReflecTech® film performance to past film products like 3M’s ECP-300 and ECP-305+ which suffered from “tunneling” [2], a problem whereby the silver reflective layer delaminates from the polymer film in the presence of moisture.
Polyhedral oligomeric silsesquioxane(POSS)-based polymers (1998)

A diverse and entirely new class of monomer and polymer technology based on polyhedral oligomeric silsesquioxane (POSS) reagents has been developed. POSS reagents are unique in that they are physically large (approx. 15 Å diameter and 1000 amu) and are composed of a robust silicon–oxygen framework that can be easily functionalized with a variety of organic substituents. Appropriate functionalization of POSS cages allows for their incorporation into traditional thermoplastic resins without modification of existing manufacturing processes. The incorporation of POSS segments into linear copolymer systems results in increased glass transition and decomposition temperatures, increased oxygen permeability and reduced flammability and heat evolution, as well as modified mechanical properties relative to conventional organic systems. © 1998 John Wiley & Sons, Ltd.
Repetitive transcranial magnetic stimulator with controllable pulse parameters (2011)

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.
Hepcidin Mitigates Renal Ischemia-Reperfusion Injury by Modulating Systemic Iron Homeostasis (2015)

Iron-mediated oxidative stress is implicated in the pathogenesis of renal ischemia-reperfusion injury. Hepcidin is an endogenous acute phase hepatic hormone that prevents iron export from cells by inducing degradation of the only known iron export protein, ferroportin. In this study, we used a mouse model to investigate the effect of renal ischemia-reperfusion injury on systemic iron homeostasis and determine if dynamic modulation of iron homeostasis with hepcidin has therapeutic benefit in the treatment of AKI. Renal ischemia-reperfusion injury induced hepatosplenic iron export through increased ferroportin expression, which resulted in hepatosplenic iron depletion and an increase in serum and kidney nonheme iron levels. Exogenous hepcidin treatment prevented renal ischemia-reperfusion-induced changes in iron homeostasis. Hepcidin also decreased kidney ferroportin expression and increased the expression of cytoprotective H-ferritin. Hepcidin-induced restoration of iron homeostasis was accompanied by a significant reduction in ischemia-reperfusion-induced tubular injury, apoptosis, renal oxidative stress, and inflammatory cell infiltration. Hepcidin -: deficient mice demonstrated increased susceptibility to ischemia-reperfusion injury compared with wild-type mice. Reconstituting hepcidin-deficient mice with exogenous hepcidin induced hepatic iron sequestration, attenuated the reduction in renal H-ferritin and reduced renal oxidative stress, apoptosis, inflammation, and tubular injury. Hepcidin-mediated protection was associated with reduced serum IL-6 levels. In summary, renal ischemia-reperfusion injury results in profound alterations in systemic iron homeostasis. Hepcidin treatment restores iron homeostasis and reduces inflammation to mediate protection in renal ischemia-reperfusion injury, suggesting that hepcidin-ferroportin pathway holds promise as a novel therapeutic target in the treatment of AKI.
Beneficial Effects of Defibrotide against Myocardial Ischemia and Decline of β-Adrenoceptor Function in the Rabbit (1986)

Defibrotide is a polydeoxyribonucleotide of mammalian origin which possesses profibrinolytic effect and PGI2-releasing capacity. Because of these properties, defibrotide has antithrombotic effects which are demonstrated in various experimental models of venous and arterial thrombosis. The present study indicates that defibrotide clearly protects against myocardial damage in the rabbit 3 days after total coronary artery occlusion. Furthermore, defibrotide prevents the decline of beta-adrenergic receptor function, a phenomenon related to excessive circulating catecholamines that occurs during the myocardial infarct. Defibrotide prevents the dramatic fall of creatine phosphokinase activity in the ischemic ventricle: metabolic changes which reflect changes in the cells affected by prolonged ischemia. Assumptions about the mode of action of defibrotide are given particularly in consideration of the interaction between the fibrinolytic activity and the PGI2-releasing capacity of this substance.
Experimental investigation of a general real-time 3D target localization method using sequential kV imaging combined with respiratory monitoring (2012)

The goal of this work was to experimentally quantify the geometric accuracy of a novel real-time 3D target localization method using sequential kV imaging combined with respiratory monitoring for clinically realistic arc and static field treatment delivery and target motion conditions. A general method for real-time target localization using kV imaging and respiratory monitoring was developed. Each dimension of internal target motion T(x, y, z; t) was estimated from the external respiratory signal R(t) through the correlation between R(t(i)) and the projected marker positions p(x(p), y(p); t(i)) on kV images by a state-augmented linear model: T(x, y, z; t) = aR(t) + bR(t - τ) + c. The model parameters, a, b, c, were determined by minimizing the squared fitting error ∑‖p(x(p), y(p); t(i)) - P(θ(i)) · (aR(t(i)) + bR(t(i) - τ) + c)‖(2) with the projection operator P(θ(i)). The model parameters were first initialized based on acquired kV arc images prior to MV beam delivery. This method was implemented on a trilogy linear accelerator consisting of an OBI x-ray imager (operating at 1 Hz) and real-time position monitoring (RPM) system (30 Hz). Arc and static field plans were delivered to a moving phantom programmed with measured lung tumour motion from ten patients. During delivery, the localization method determined the target position and the beam was adjusted in real time via dynamic multileaf collimator (DMLC) adaptation. The beam-target alignment error was quantified by segmenting the beam aperture and a phantom-embedded fiducial marker on MV images and analysing their relative position. With the localization method, the root-mean-squared errors of the ten lung tumour traces ranged from 0.7-1.3 mm and 0.8-1.4 mm during the single arc and five-field static beam delivery, respectively. Without the localization method, these errors ranged from 3.1-7.3 mm. In summary, a general method for real-time target localization using kV imaging and respiratory monitoring has been experimentally investigated for arc and static field delivery. The average beam-target error was 1 mm.
ChemInform Abstract: THE ANODIC EVOLUTION OF OZONE (1982)

Abstract Die Trends der anodischen O3‐Entwicklungsreaktion werden für eine Reihe unterschiedlicher Anodenmaterialien und Elektrolytkombinationen charakterisiert.
<title>Compression of concentric mosaic scenery with alignment and 3D wavelet transform</title> (2000)

As a new scene representation scheme, the concentric mosaic offers a quick way to capture and model a realistic 3D environment. This is achieved by shooting a lot of photos of the scene. Novel views can be rendered by patching vertical slits of the captured shots. The data amount in the concentric mosaic is huge. In this work, we compress the concentric mosaic image array with a 3D wavelet scheme. The proposed scheme first aligns the mosaic images, and then applies a 3D wavelet transform on the aligned mosaic image array. After that, the wavelet coefficients in each subband are split into cubes, where each of the cubes is encoded independently with an embedded block coder. Various cube bitstreams are then assembled to form the final compressed bitstream. Experimental result shows that the proposed 3D wavelet coder achieves a good compression performance.
Acoustic Source Separation Using Rigid Spherical Microphone Arrays Via Spatially Weighted Orthogonal Matching Pursuit (2018)

Acoustic source separation refers to the extraction of individual source signals from microphone array recordings of multiple sources made in multipath environments such as rooms. The most straightforward approach to acoustic source separation involves spatial filtering via beamforming. While beamforming works well for a few sources and under low reverberation, its performance diminishes for a high number of sources and/or high reverberation. An informed acoustic source separation method based on the application of orthogonal matching pursuit (OMP) on complex-valued steered response (SR) maps is presented in this paper. It is shown that the proposed method is robust to a high level of reverberation and affords better source separation than maximally directive steered beamforming in terms of signal-to-interference and signal-to-distortion ratios.
Load balancing for multiple traffic matrices using SDN hybrid routing (2014)

Classical traffic engineering (TE) methods calculate the optimal routing based on a single traffic matrix. However, they are unable to handle unexpected traffic changes. Thus, it is of interest to find a good routing configuration to accommodate multiple possible traffic scenarios. There are two major approaches to achieve load balancing for multiple traffic matrices: destination-based routing and explicit routing. It has been shown that explicit routing performs better than destination-based routing for multiple traffic matrices. However, explicit routing has high complexity and requires large Ternary Content Addressable Memory (TCAM) in the routers. Thus, it is power hungry and unscalable. This paper presents an approach called hybrid routing to achieve load balancing for multiple traffic matrices with low complexity and good scalability. Our basic idea is to complement destination-based routing with a small number of explicit routing forwarding entries to take advantage of both two routing approaches. Hybrid routing greatly reduces the number of forwarding entries compared with pure explicit routing. This has great value for practice in that the scheme requires very small TCAM to implement. Hybrid routing is very suitable for implementation using SDN. A heuristic algorithm is developed to obtain the near-optimal hybrid routing configuration. Extensive evaluation demonstrates the effectiveness of hybrid routing. The results show that hybrid routing achieves near-optimal load balancing compared with pure explicit routing. In particular, hybrid routing saves at least 84.6% TCAM resources in all practical networks used in our evaluation.
Improved Ruthenium Catalysts for <i>Z</i>-Selective Olefin Metathesis (2011)

Several new C-H-activated ruthenium catalysts for Z-selective olefin metathesis have been synthesized. Both the carboxylate ligand and the aryl group of the N-heterocyclic carbene have been altered and the resulting catalysts evaluated using a range of metathesis reactions. Substitution of bidentate with monodentate X-type ligands led to a severe attenuation of metathesis activity and selectivity, while minor differences were observed between bidentate ligands within the same family (e.g., carboxylates). The use of nitrato-type ligands in place of carboxylates afforded a significant improvement in metathesis activity and selectivity. With these catalysts, turnover numbers approaching 1000 were possible for a variety of cross-metathesis reactions, including the synthesis of industrially relevant products.