gebhart/patrepeval huggingface dataset:
Control of Variable Speed Wind Turbines with Doubly-Fed Induction Generators (2004)

The paper presents an overall control method for variable speed pitch controlled wind turbines with doubly-fed induction generators (DFIG). Emphasis is on control strategies and algorithms applied at each hierarchical control level of the wind turbine. The objectives of the control system are: 1) to control the power drawn from the wind turbine in order to track the wind turbine maximum power operation point, 2) to limit the power in case of large wind speeds, and 3) to control the reactive power interchanged between the wind turbine generator and the grid. The present control method is designed for normal continuous operations. The strongest feature of the implemented control method is that it allows the turbine to operate with the optimum power efficiency over a wider range of wind speeds. The model of the variable speed, variable pitch wind turbine with doubly-fed induction generator is implemented in the dynamic power system simulation tool DIgSILENT PowerFactory which allows investigation of the dynamic performance of grid-connected wind turbines within realistic electrical grid models. Simulation results are presented and analysed in different normal operating conditions.
Allenes in Asymmetric Catalysis: Asymmetric Ring Opening of meso-Epoxides Catalyzed by Allene-Containing Phosphine Oxides (2009)

Unsymmetrically substituted allenes (1,2-dienes) are inherently chiral and can be prepared in optically pure form. Nonetheless, to date the allene framework has not been incorporated into ligands for asymmetric catalysis. Since allenes project functionality differently than either tetrahedral carbon or chiral biaryls, they may create complementary chiral environments. This study demonstrates that optically active, C(2)-symmetric allene-containing bisphosphine oxides can catalyze the addition of SiCl(4) to meso-epoxides with high enantioselectivity. The epoxide opening likely involves generation of a Lewis acidic, cationic (bisphosphine oxide)SiCl(3) complex. The fact that high asymmetric induction is observed suggests that allenes may represent a new platform for the development of ligands and catalysts for asymmetric synthesis.
New control scheme for 3-phase PWM AC/DC converter without phase angle detection under unbalanced input voltage conditions (2002)

Generally, most of 3-phase PWM AC/DC converters have been implemented in the synchronous frame model to eliminate steady state errors effectively and have fast transient response characteristics. But such designed controllers have input current harmonics and DC-link voltage ripples under unbalanced input voltage conditions because they have been designed under assumption of balanced input voltage conditions. In this paper, the new control scheme is designed to minimize harmonic distortions of the input current and the output DC-link voltage in 3-phase PWM AC/DC converter systems under unbalanced input voltage conditions. The synchronous frame input voltage, which is considered as input side back-EMF component, is regulated pertinently according to input voltage condition. Where, the analysis of the input voltage is implemented without zero crossing and magnitude detecting of each phase voltage. The current reference is selected to eliminate the reactive power and the harmonic active power. The proposed control scheme is simple and minimizes effectively the harmonic distortions in input and output system under unbalanced input voltage conditions.
<title>Imaging Through Atmospheric Turbulence Using Modified Log Gradients</title> (1982)

A new approach to the problem of imaging through a time-varying randomly inhomogeneous medium is presented. This method assumes that an ensemble of short exposure images of a single fixed scene or object is available. It also assumes that knowledge of the average short-term optical transfer function is either known or estimated empirically from a point reference source. Restoration is performed by averaging a modified log gradient of the observed image spectra. This log gradient operator is an exact, mapping of discrete convolution into finite-field addi-tion, and is closely related to the complex &quot;cepstrum,&quot; popularized by Oppenheim, It is shown to be invertible to within a constant multiplicative factor by a series of eigenvector computations. The mathematics of this gradient operator are developed, and two-dimensional simulations are presented.
Flow Patterns and Characteristics in Multiphase Riser Pipelines (2006)

Abstract Flow characteristics (e.g. flow pattern, slug frequency and Froude number) in 45 degree pipeline and the effect of inclination on corrosion rates in 0°, 3° and 45° inclination were investigated using a 10.16 cm diameter, 36 m long, multiphase flow loop. Superficial liquid velocities between 0.5 and 1.5 m/s and superficial gas velocities between 2 and 6 m/s were studied. Light condensate oil with a viscosity of 2.5 cP was used and brine cut was 80%. The experiments were undertaken at pressures of 0.12 and 0.3 MPa and temperatures of 25 and 58 °C with carbon dioxide as the gas. Visual observations showed that the flow is substantially changed when the pipeline is set at a 45 degree inclination. It was noticed that back flow of liquid film between slugs was observed, which led to a higher slug frequency and higher Froude number. It was also seen that continuous whirling motion occurred between slugs, which led to higher turbulence in 45 degree inclination. The corrosion rates for both bottom and top of the pipes increased significantly when the pipeline inclination was changed from 3 degrees to 45 degrees. This is due to the fact that the slug frequency and the intensity of turbulence in 45 degrees are much higher. Comparisons of temperature, pressure and inclination on corrosion rates are discussed in this paper.
Determination and Optimization of the Luminescence External Quantum Efficiency of Silver-Clusters Zeolite Composites (2013)

We have measured for the first time the external quantum efficiency (EQE) of silver clusters containing zeolites (henceforth referred to as silver-clusters zeolite composites). These materials, fabricated by silver cation exchange followed by a thermal autoreduction process, have EQEs up to 69%. Because of their unique spectral features such as large Stokes shift and high EQE, these materials could be potentially used as phosphors for the fabrication of fluorescent lamps and as wavelength convertors in solar cells. An EQE comparison between less pure commercial silver-loaded zeolites and self-synthesized silver-zeolites showed the importance of the chemical and optical purity of the starting host material. Besides this, the zeolite topology and silver content play an important role on the luminescent performance of such materials. The ability to reliably measure the EQE enabled us to further optimize the synthesis of silver-zeolite composites. A new reduction–oxidation cycle is demonstrated not only to improve the luminescent performance of the silver-zeolite composites but also to enhance their water stability.
A Systematic Study on the Effects of Dimensional and Materials Tolerances on Permanent Magnet Synchronous Machines Based on the IEEE Std 1812 (2018)

In the process of designing and manufacturing an electrical machine, a systematic study of dimensional and material tolerances is of the utmost importance. This paper proposes a systematic method by which the effect of design specification variations on permanent magnet (PM) synchronous machine performance may be identified and quantified. The method combines design of experiments techniques, open-circuit and short-circuit physical measurements, and virtual test simulations conducted based on the recently approved IEEE Std 1812 testing guide. Three case studies, two provided by a spoke-type PM radial field machine configuration, in two designs with different electromagnetic loading, and an axial flux PM machine are discussed. It is shown that based on the output performance, out of specification tolerances for magnet remanence, steel grade, as well as dimensional variables, and stator to rotor eccentricity, may be identified under certain conditions. It is also exemplified that the ratings, magnetic loading, and configuration of the machine play critical roles and should be thoroughly considered as part of the studies.
Selective immunosuppression with anti‐interleukin 2 receptor‐targeted therapy: helper and suppressor cell activity in rat recipients of cardiac allografts (1987)

(LEW X BN)F1 cardiac allografts are rejected within 8 days in unmodified LEW rats. ART18, a mouse anti-rat IgG1 monoclonal antibody which binds specifically in vitro to the interleukin 2 receptor (IL 2R) molecule expressed primarily on activated T cells, prolongs allograft survival in a dose-dependent fashion to ca. 3 weeks (p less than 0.001) after being administered for 10 days after transplantation. This effect was related to the specificity of the antibody for IL 2R, as therapy with ART62 (a monoclonal antibody recognizing MHC class I antigen but not binding the rat IL 2R) was ineffectual. Suppressor activity was detected in spleen cells of ART18-treated grafted hosts: in vivo, splenic T suppressor/cytotoxic fraction adoptively transferred into normal LEW improved donor-specific but not third-party test graft survival (17 days, vs. 8 days, respectively, p less than 0.001); in vitro, mixed lymphocyte reaction was profoundly but nonspecifically inhibited (less than 5% of test mixed lymphocyte reaction, p less than 0.001 as compared to acutely rejecting controls). In contrast, splenic T helper (Th) cells from ART18-treated hosts were functionally depressed, as noted by their passive transfer into immunologically anergic B recipients of cardiac allografts (rejection in ca. 40 days, vs. ca. 13 days after transfer of Th from specifically sensitized rats). ART18 treatment also resulted in diminished elaboration of IL 2 as compared to normal (p less than 0.005) or acutely rejecting hosts (p less than 0.001); however, a remarkable increase in the production of IL 3 occurred (p less than 0.001). These results demonstrate that IL 2R-targeted therapy of immunocompetent graft recipients produces a selective immune defect in which donor-specific T suppressor cells are spared, but Th cells attenuated or destroyed. Decreased elaboration of IL2 concomitantly augments the release of IL 3, a lymphokine which might play a role in suppressor effect in vivo. In addition, IL 2R-targeted therapy of the immunodeficient graft recipients abrogates the capacity of alloactivated T cells to re-establish acute immune responsiveness.
Longitudinal optical imaging of tumor metabolism and hemodynamics (2010)

An important feature of tumor hypoxia is its temporal instability, or "cycling hypoxia." The primary consequence of cycling hypoxia is increased tumor aggressiveness and treatment resistance beyond that of chronic hypoxia. Longitudinal imaging of tumor metabolic demand, hemoglobin oxygen saturation, and blood flow would provide valuable insight into the mechanisms and distribution of cycling hypoxia in tumors. Fluorescence imaging of metabolic demand via the optical redox ratio (fluorescence intensity of FAD/NADH), absorption microscopy of hemoglobin oxygen saturation, and Doppler optical coherence tomography of vessel morphology and blood flow are combined to noninvasively monitor changes in oxygen supply and demand in the mouse dorsal skin fold window chamber tumor model (human squamous cell carcinoma) every 6 h for 36 h. Biomarkers for metabolic demand, blood oxygenation, and blood flow are all found to significantly change with time (p<0.05). These variations in oxygen supply and demand are superimposed on a significant (p<0.05) decline in metabolic demand with distance from the nearest vessel in tumors (this gradient was not observed in normal tissues). Significant (p<0.05), but weak (r<or=0.5) correlations are found between the hemoglobin oxygen saturation, blood flow, and redox ratio. These results indicate that cycling hypoxia depends on both oxygen supply and demand, and that noninvasive optical imaging could be a valuable tool to study therapeutic strategies to mitigate cycling hypoxia, thus increasing the effectiveness of radiation and chemotherapy.
Artificial Photosynthesis. 2. Investigations on the Mechanism of Photosensitization of Nanocrystalline TiO2 Solar Cells by Chlorophyll Derivatives (1994)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTArtificial Photosynthesis. 2. Investigations on the Mechanism of Photosensitization of Nanocrystalline TiO2 Solar Cells by Chlorophyll DerivativesAndreas Kay, Robin Humphry-Baker, and Michael GraetzelCite this: J. Phys. Chem. 1994, 98, 3, 952–959Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://pubs.acs.org/doi/10.1021/j100054a035https://doi.org/10.1021/j100054a035research-articleACS PublicationsRequest reuse permissionsArticle Views2490Altmetric-Citations318LEARN 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 options Get e-Alerts
Omics techniques and biobanks to find new biomarkers for the early detection of acute lymphoblastic leukemia in middle-income countries: a perspective from Mexico (2017)

Acute lymphoblastic leukemia (ALL) affects the quality of life of many children in the world and particularly in Mexico, where a high incidence has been reported. With a proper financial investment and with well-organized institutions caring for those patients, together with solid platforms to perform high-throughput analyses, we propose the creation of a Mexican repository system of serum and cells from bone marrow and blood samples derived from tissues of pediatric patients with ALL diagnosis. This resource, in combination with omics technologies, particularly proteomics and metabolomics, would allow longitudinal studies, offering an opportunity to design and apply personalized ALL treatments. Importantly, it would accelerate the development of translational science and will lead us to further discoveries, including the identification of new biomarkers for the early detection of leukemia.
Automatic verification methodology based on structural test patterns (2009)

Functional verification is a major bottleneck in today's design flow. Current technologies are not meeting the challenges imposed by design complexity. In this paper, we propose a new simulation-based verification methodology based on the use of automatically generated structural test patterns in the RTL simulation. The presented approach generally improves the simulation-based verification's quality, keeping the integration, the applicability and the automation aspects in close proximity.
Frequency measurement on the 5s5p P23−5s4d D33 transition of Sr88 atoms using the photon-momentum-transfer technique (2019)

We report a frequency measurement on the $5s5p\phantom{\rule{0.16em}{0ex}}^{3}P_{2}\ensuremath{-}5s4d\phantom{\rule{0.16em}{0ex}}^{3}D_{3}$ transition of $^{88}\mathrm{Sr}$ atoms at $2.9\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$. The excitation spectra are obtained by measuring the photon momenta transferred to ultracold atoms. The transition frequency is determined to be 102 550 196 205(9) kHz using an erbium fiber-based optical frequency comb. We numerically investigate possible frequency corrections by taking an acceleration of atoms and attenuation of the excitation light into account. This measurement technique is particularly useful for transitions where laser-induced fluorescence is difficult to observe but the spatial imaging of atoms is possible.
Pulling force generated by interacting SNAREs facilitates membrane hemifusion (2009)

In biological systems, membrane fusion is mediated by specialized proteins. Although soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptors (SNAREs) provide the minimal molecular machinery required to drive membrane fusion, the precise mechanism for SNARE-mediated fusion remains to be established. Here, we used atomic force microscope (AFM) spectroscopy to determine whether the pulling force generated by interacting SNAREs is directly coupled to membrane fusion. The mechanical strength of the SNARE binding interaction was determined by single molecule force measurements. It was revealed that the forced unbinding of the SNARE complex formed between opposing (trans) bilayers involves two activation barriers; where the steep inner barrier governs the transition from the bound to an intermediate state and the outer barrier governs the transition between the intermediate and the unbound state. Moreover, truncation of either SNAP-25 or VAMP 2 reduced the slope of the inner barrier significantly and, consequently, reduced the pulling strength of the SNARE complex; thus, suggesting that the inner barrier determines the binding strength of the SNARE complex. In parallel, AFM compression force measurements revealed that truncated SNAREs were less efficient than native SNAREs in facilitating hemifusion of the apposed bilayers. Together, these findings reveal a mechanism by which a pulling force generated by interacting trans-SNAREs reduces the slope of the hemifusion barrier and, subsequently, facilitates hemifusion and makes the membranes more prone to fusion.
A comparison of the high‐affinity peripheral benzodiazepine receptor ligands DAA1106 and (R)‐PK11195 in rat models of neuroinflammation: implications for PET imaging of microglial activation (2007)

Activated microglia are an important feature of many neurological diseases and can be imaged in vivo using 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK11195), a ligand that binds the peripheral benzodiazepine receptor (PBR). N-(2,5-dimethoxybenzyl)-N-(5-fluoro-2-phenoxyphenyl) acetamide (DAA1106) is a new PBR-specific ligand that has been reported to bind to PBR with higher affinity compared with PK11195. We hypothesized that this high-affinity binding of DAA1106 to PBR will enable better delineation of microglia in vivo using positron emission tomography. [(3)H]DAA1106 showed higher binding affinity compared with [(3)H](R)-PK11195 in brain tissue derived from normal rats and the rats injected intrastriatally with 6-hydroxydopamine or lipopolysaccharide at the site of the lesion. Immunohistochemistry combined with autoradiography in brain tissues as well as correlation analyses showed that increased [(3)H]DAA1106 binding corresponded mainly to activated microglia. Finally, ex vivo autoradiography and positron emission tomography imaging in vivo showed greater retention of [(11)C]DAA1106 compared with [(11)C](R)-PK11195 in animals injected with either lipopolysaccaride or 6-hydroxydopamine at the site of lesion. These results indicate that DAA1106 binds with higher affinity to microglia in rat models of neuroinflammation when compared with PK11195, suggesting that [(11)C]DAA1106 may represent a significant improvement over [(11)C](R)-PK11195 for in vivo imaging of activated microglia in human neuroinflammatory disorders.
Gradient Elution in Capillary Electrochromatography (1996)

In analogy to pressure-driven gradient techniques in high-performance liquid chromatography, a system has been developed for delivering electroosmotically driven solvent gradients for capillary electrochromatography (CEC). Dynamic gradients with submicroliter per minute flow rates are generated by merging two electroosmotic flows that are regulated by computer-controlled voltages. These flows are delivered by two fused-silica capillary arms attached to a T-connector, where they mix and then flow into a capillary column that has been electrokinetically packed with 3-μm reversed-phase particles. The inlet of one capillary arm is placed in a solution reservoir containing one mobile phase, and the inlet of the other is placed in a second reservoir containing a second mobile phase. Two independent computer-controlled, programmable, high-voltage power supplies (0-50 kV) [Formula: see text] one providing an increasing ramp and the other providing a decreasing ramp [Formula: see text] are used to apply variable high-voltage potentials to the mobile phase reservoirs to regulate the electroosmotic flow in each arm. The ratio of the electroosmotic flow rates between the two arms is changed with time according to the computer-controlled voltages to deliver the required gradient profile to the separation column. Experiments were performed to confirm the composition of the mobile phase during a gradient run and to determine the change of the composition in response to the programmed voltage profile. To demonstrate the performance of electroosmotically driven gradient elution in CEC, a mixture of 16 polycyclic aromatic hydrocarbons was separated in less than 90 min. This gradient technique is expected to be well-suited for generating not only solvent gradients in CEC but also other types of gradients, such as pH and ionic strength gradients, in capillary electrokinetic separations and analyses.
Task Group 174 Report: Utilization of [18F]Fluorodeoxyglucose Positron Emission Tomography ([18F]FDG‐PET) in Radiation Therapy (2019)

The use of positron emission tomography (PET) in radiation therapy (RT) is rapidly increasing in the areas of staging, segmentation, treatment planning, and response assessment. The most common radiotracer is <sup>18</sup> F-fluorodeoxyglucose ([<sup>18</sup> F]FDG), a glucose analog with demonstrated efficacy in cancer diagnosis and staging. However, diagnosis and RT planning are different endeavors with unique requirements, and very little literature is available for guiding physicists and clinicians in the utilization of [<sup>18</sup> F]FDG-PET in RT. The two goals of this report are to educate and provide recommendations. The report provides background and education on current PET imaging systems, PET tracers, intensity quantification, and current utilization in RT (staging, segmentation, image registration, treatment planning, and therapy response assessment). Recommendations are provided on acceptance testing, annual and monthly quality assurance, scanning protocols to ensure consistency between interpatient scans and intrapatient longitudinal scans, reporting of patient and scan parameters in literature, requirements for incorporation of [<sup>18</sup> F]FDG-PET in treatment planning systems, and image registration. The recommendations provided here are minimum requirements and are not meant to cover all aspects of the use of [<sup>18</sup> F]FDG-PET for RT.