gebhart/patrepeval huggingface dataset:
Frequency Offset Estimation with Increased Nyquist Frequency (2010)

In wireless communication systems, there is a need to estimate and compensate for frequency offsets. What is common to frequency offset estimators, is that they only can give correct results within a certain range, up to the Nyquist frequency. This makes a difference especially in OFDM systems with pilots only at certain symbols, such as LTE. In this paper we present an algorithm where the Nyquist frequency is increased, up to the same value as if pilots were present in all OFDM symbols. The algorithm is based on using two or more frequency offset estimators, with lower, but different, Nyquist frequencies.
Experimental And Numerical Study Of A Gas Turbine Exhaust Diffuser Applying Different Hub Extension Geometries (2015)

Exhaust diffusers are utilized to recover the residual kinetic energy of the last turbine stage. The investigated diffuser consists of an annular duct and an attached Carnot diffuser. The baseline diffuser of the investigated gas turbine features a blunt end at hub, which leads to an extensive separated flow region in the Carnot diffuser. In order to reduce the separation size and the implicated losses, four different hub extension geometries and the baseline are examined numerically and experimentally for two operating conditions. The wind tunnel tests are compared to the numerical results, which are obtained by using the CFD code TRACE. Three competing performance parameters are used for analysis: pressure recovery coefficient, total pressure loss and flow uniformity factor. The investigated hub extensions lead to a reduction of the separation zones downstream of the hubs end. This results in a better diffuser performance in terms of pressure recovery coefficient and total pressure loss of all extensions compared to the baseline. As expected, the ellipsoidal extension gives the highest pressure recovery coefficient for an infinite Carnot diffuser length. At the given length of the Carnot in this case, the Hollow Cylinder lead to the best compromise for all performance parameters. In sum, the choice of the geometry depends on the available length of the Carnot diffuser and its related costs.
Ongoing Development of a Low Emission Axisymmetric Annular Vortex Combustor for an Industrial Gas Turbine (1980)

An axisymmetric annular vortex combustor was tested atmospherically to determine the feasibility of meeting the 1977 proposed EPA emission standards for stationary gas turbines. Flame stabilization was achieved solely by swirl induced recirculation without the jet assisted recirculation of conventional practice. Buoyancy forces are used to enhance or diminish turbulent mixing. It was found that by uniformly mixing gaseous fuel and air prior to combustion and burning fuel lean it was possible to meet the proposed emission standards. The resultant narrow range of flame stability necessitated fuel staging for light-off and off-design operation. Fuel staging was achieved by stratified charge combustion (diffusion flame). Changes in combustor geometry were made and extensive traversing of the flame zone was carried out to measure concentrations of chemical species.
New Moveout Approximation for Walkaway VSP Geometry in a 3D Anisotropic Model (2013)

I introduce a new explicit form of vertical seismic profile (VSP) traveltime approximation for a 3D model with non-horizontal boundaries and anisotropic layers. The goal of the new approximation is to dramatically decrease cost of time calculations by reducing the number of calculated rays in a complex multi-layered anisotropic model for VSP walkaway data with many sources. This traveltime approximation extends the generalized moveout approximation proposed by Fomel and Stovas. The new equation is designed for borehole seismic geometry where the receivers are placed in a well while the sources are on the surface. Testing this new approximation for the 3D anisotropic model with dipping boundaries shows its very high accuracy for offsets up to three depths. The new approximation can be used for 3D anisotropic models with tilted symmetry axes for practical VSP geometry calculations. The new explicit approximation eliminates the need of massive raytracing in a complicated velocity model for multi-source VSP surveys.
Experimental Observation of Multifrequency Patterns in Arrays of Coupled Nonlinear Oscillators (2003)

Frequency-related oscillations in coupled oscillator systems, in which one or more oscillators oscillate at different frequencies than the other oscillators, have been studied using group theoretical methods by Armbruster and Chossat [Phys. Lett. A 254, 269 (1999)] and more recently by Golubitsky and Stewart [in Geometry, Mechanics, and Dynamics, edited by P. Newton, P. Holmes, and A. Weinstein (Springer, New York, 2002), p. 243]. We demonstrate, experimentally, via electronic circuits, the existence of frequency-related oscillations in a network of two arrays of N oscillators, per array, coupled to one another. Under certain conditions, one of the arrays can be induced to oscillate at N times the frequency of the other array. This type of behavior is different from the one observed in a driven system because it is dictated mainly by the symmetry of the coupled system.
Efficient Oligomerization of Pentene into Liquid Fuels on Nanocrystalline Beta Zeolites (2017)

Light alkenes oligomerization, performed in the presence of heterogeneous acid catalysts, is an interesting alternative for the production of clean liquid fuels. The process, when catalyzed by zeolites, is flexible and can be directed to the formation of oligomers in the gasoline, jet fuel, or diesel range by adjusting the reaction conditions and the zeolite’s structure. Herein we show how reducing the crystal size of large-pore Beta zeolites down to 10–15 nm and controlling the number and strength distribution of their Brønsted acid sites leads to highly active and stable catalysts, selective to true oligomers within the naphtha and, especially, the diesel range. The shorter diffusion path lengths in the smaller crystallites and the reduced Brønsted acid site density of the two nanosized beta zeolites (10–15 nm) synthesized with Si/Al = 15 lead to 1-pentene conversion above 80% during the 6 h time on stream (TOS) at a space time (W/F) of 2.8 g·h·mol–1. This value is higher than the olefin conversion obtained for a commercial nanobeta (30 nm) at a 3-fold space time of 9.1 g·h·mol–1.
Structure-Based Design of an Organoruthenium Phosphatidyl-inositol-3-kinase Inhibitor Reveals a Switch Governing Lipid Kinase Potency and Selectivity (2008)

Mutations that constitutively activate the phosphatidyl-inositol-3-kinase (PI3K) signaling pathway, including alterations in PI3K, PTEN, and AKT, are found in a variety of human cancers, implicating the PI3K lipid kinase as an attractive target for the development of therapeutic agents to treat cancer and other related diseases. In this study, we report on the combination of a novel organometallic kinase inhibitor scaffold with structure-based design to develop a PI3K inhibitor, called E5E2, with an IC 50 potency in the mid-low-nanomolar range and selectivity against a panel of protein kinases. We also show that E5E2 inhibits phospho-AKT in human melanoma cells and leads to growth inhibition. Consistent with a role for the PI3K pathway in tumor cell invasion, E5E2 treatment also inhibits the migration of melanoma cells in a 3D spheroid assay. The structure of the PI3Kgamma/E5E2 complex reveals the molecular features that give rise to this potency and selectivity toward lipid kinases with implications for the design of a subsequent generation of PI3K-isoform-specific organometallic inhibitors.
Photochromism of side-chain liquid crystal polymers containing spironaphthoxazines (1990)

Abstract Side-chain liquid crystal polyacrylates and polysiloxanes containing different photochromic spironaphthoxazine side groups were synthesized. Thermodynamic, spectral and kinetic properties of the polymers were investigated. The structure of the mesophase is discussed.
Monoclonal Antibodies Specific for the Beer-Spoilage Ability of Lactic Acid Bacteria (2000)

Lactobacillus brevis, L. lindneri, and Pediococcus damnosus are primary dangerous contaminants for packaged beer; however, all of the strains classified in these species are not able to grow in beer. Our goal was to obtain monoclonal antibodies (MAbs) specific for the beer-spoilage ability of lactic acid bacteria. Mice were immunized with whole cells of lactic acid bacteria cultured in beer, and three MAbs (BLb2F37, BG3A5b4, and PQ3H8a9) were obtained. The BLb2F37 reacted with all beer-spoilage strains of L. brevis and several beer-spoilage strains of P. damnosus, whereas it did not react with the nonbeer-spoilage strains of L. brevis, P. damnosus, and other lactic acid bacteria. The PQ3H8a9 significantly reacted with all the beer-spoilage strains of P. damnosus and also reacted weakly with many of the beer-spoilage strains of L. brevis. The BG3A5b4 specifically reacted with L. lindneri. When the lactic acid bacteria growing in beer were inoculated and successively cultured in modified DeMan-Rogosa-Sharpe broth (pH 5.2), L. brevis began to lose reactivity with the MAbs, whereas L. lindneri and P. damnosus did not. Culturing in medium including isohumulones or treatment of cells with sodium hydroxide improved the reactivity of L. brevis with the MAbs; however, the improved reactivity was not as high as the reactivity of L. brevis growing in beer. It was suggested that the antigens were optimally expressed on the cells growing in beer regardless of the presence of the isohumulones. Using these MAbs, we also developed a simple, rapid, and sensitive kit for prediction of the beer-spoilage ability of lactic acid bacteria.
Transgenic Plants Created for Oral Immunization Against Diarrheal Diseases (1996)

We have created transgenic plants that express subunit antigens of infectious bacteria and viruses. These proteins have been isolated and characterized to demonstrate that they retain immunogenic properties. When raw potatoes containing the recombinant immunogens were fed to mice, the animals were orally immunized. Research completed to date has demonstrated the feasibility of using a genetically-engineered food as an inexpensive oral vaccine production and delivery system for diarrheal disease. The system could be a convenient means to deliver vaccines to travelers. It also has great potential as an appropriate technology for producing vaccines "in country" in the developing world. This review focuses on work from our group on recombinant subunit vaccines in potato tubers against enterotoxigenic Escherichia coli and Norwalk virus.
Preferential Inhibition of BMAL2-CLOCK Activity by PER2 Reemphasizes Its Negative Role and a Positive Role of BMAL2 in the Circadian Transcription (2009)

In the molecular oscillatory mechanism governing circadian rhythms, positive regulators, including CLOCK and BMAL1, transactivate Per and Cry genes through E-box elements, and translated PER and CRY proteins negatively regulate their own transactivation. Like BMAL1, its paralog BMAL2 dimerizes with CLOCK to activate the E-box-dependent transcription, but the role of BMAL2 in the circadian clockwork is still elusive. Here we characterized BMAL2 function in NIH3T3 cells and found that the cellular rhythms monitored by Bmal1 promoter-driven bioluminescence signals were blunted by RNA interference-mediated suppression of Bmal2 as well as that of Bmal1. Transcription assays with a 2.1-kb mPer1 promoter revealed that CRY2 inhibited the transactivation mediated by BMAL1-CLOCK more strongly than that by BMAL2-CLOCK. In contrast, PER2 showed a stronger inhibitory effect on BMAL2-CLOCK than on BMAL1-CLOCK. The molecular link between BMAL2 and PER2 was further strengthened by the fact that PER2 exhibited a greater affinity for BMAL2 than for BMAL1 in co-immunoprecipitation experiments. These results indicate a functional partnership between BMAL2 and PER2 and reemphasize the negative role of PER2 in the circadian transcription. As a broad spectrum function, BMAL2-CLOCK activated transcription from a variety of SV40-driven reporters harboring various E/E'-box-containing sequences present in the upstream regions of clock and clock-controlled genes. Importantly, the efficiencies of BMAL2-CLOCK-mediated transactivation relative to that achieved by BMAL1-CLOCK were dependent heavily on the E-box-containing sequences, supporting distinguishable roles of the two BMALs. Collectively, it is strongly suggested that BMAL2 plays an active role in the circadian transcription.
Scaling and statistical dependencies of second-order polarization mode dispersion in optical fibers (2003)

Muller-matrix-method measurements of fibers with mean differential group delays (DGD) ranging from 1.3 ps to 17.0 ps and simulations confirm that the depolarization scales with the mean DGD while the polarization-dependent chromatic dispersion scales with the square of the mean DGD.
MEMS phase shifters using cascaded slow-wave structures for improved impedance matching and/or phase shift (2004)

A new true time delay MEM phase shifter topology based on impedance-matched slow-wave CPW sections is presented. Experimental data for a 4.6 mm long device shows 317/spl deg//dB phase shift at 50 GHz (or 91/spl deg//mm) with S11 less than -21 dB from 1-50 GHz. In a second design, the slow wave phase shifter was additionally loaded with MEM capacitors to result in a phase shift of 257/spl deg//dB at 50 GHz, while keeping S11 below -19dB. The beams are actuated using high resistance bias lines with typical actuation voltage around 30-45V.
Mucoadhesive formulation of Bidens pilosa L. (Asteraceae) reduces intestinal injury from 5-fluorouracil-induced mucositis in mice (2015)

Gastrointestinal mucositis induced during cancer treatment is considered a serious dose-limiting side effect of chemotherapy and/or radiotherapy. Frequently, interruption of the cancer treatment due to this pathology leads to a reduction in cure rates, increase of treatment costs and decrease life quality of the patient. Natural products such as <i>Bidens pilosa</i> L. (Asteraceae), represent a potential alternative for the treatment of mucositis given its anti-inflammatory properties. In this study, <i>B. pilosa</i> glycolic extract was formulated (BPF) with poloxamer, a mucoadhesive copolymer, was used for treatment of 5-fluorouracil (5-FU)-induced mucositis in mice. As expected, animals only treated with 5-FU (200 mg/kg) presented marked weight loss, reduction of intestinal villi, crypts and muscular layer, which was associated with severe disruption of crypts, edema, inflammatory infiltrate and vacuolization in the intestinal tissue, as compared to the control group and healthy animals only treated with BPF. On the other hand, the treatment of intestinal mucositis-bearing mice with BPF (75, 100 or 125 mg/kg) managed to mitigate clinical and pathologic changes, noticeably at 100 mg/kg. This dose led to the restoration of intestinal proliferative activity through increasing Ki-67 levels; modulated the expression of Bax, Bcl2 and p53 apoptotic markers protecting intestinal cells from cell death. Moreover, this treatment regulated lipid peroxidation and inflammatory infiltration. No acute toxic effects were observed with this formulation. This work demonstrated that BPF was safe and effective against 5-FU-induced intestinal mucositis in mice. Additional studies are already in progress to further characterize the mechanisms involved in the protective effects of this technological formulation toward the development of a new medicine for the prevention and treatment of intestinal injury in patients undergoing chemotherapy/radiotherapy.
Achievement of the saturation limit and double pass amplification in a discharge pumped soft X-ray amplifier (2002)

Previously we have reported the demonstration of large soft X-ray amplification by collisional excitation of neon-like argon in the plasma column of a fast compressional capillary discharge. Herein we report the generation of laser pulse energies up to 30 /spl mu/J at 46.9 nm in the plasma column of such a discharge, and the first clear demonstration of gain saturation of a table-top soft X-ray amplifier. Single pass amplification experiments yielded laser pulse energies up to 6 /spl mu/J. Greater energies were obtained by using an iridium mirror.
Cytotoxic and antitumor activity of a recombinant immunotoxin composed of disulfide‐stabilized anti‐TAC Fv fragment and truncated <i>pseudomonas</i> exotoxin (1994)

Disulfide-stabilized Fv (dsFv)-immunotoxins are recombinant immunotoxins in which the inherently unstable Fv moiety, composed of the VH-VL heterodimer, is stabilized by a disulfide bond engineered between structurally conserved framework positions of VH and VL. Anti-Tac(dsFv)-PE38KDEL is composed of such a dsFv, directed to the alpha subunit of the IL2 receptor (IL2R), and containing a truncated form of Pseudomonas exotoxin (PE38KDEL). We have found this new type of immunotoxin to be indistinguishable in its in vitro activity and specificity from its single-chain immunotoxin counterpart, anti-Tac(Fv)-PE38KDEL. We have now examined the therapeutically relevant factors, including stability, pharmacokinetics, and antitumor activity of this new disulfide-stabilized Fv-immunotoxin. We found that anti-Tac(dsFv)-PE38KDEL was specifically cytotoxic to human activated T-lymphocytes in addition to IL2R bearing cell lines. Anti-Tac(dsFv)-PE38KDEL was considerably more stable at 37 degrees C in human serum and in buffered saline than the single-chain immunotoxin, anti-Tac(Fv)-PE38KDEL. The half-life in blood was similar for both immunotoxins (approx. 20 min). The therapeutic potential of the disulfide-stabilized immunotoxin was evaluated using an animal model of immunodeficient mice bearing subcutaneous tumor xenografts of human IL2R-bearing cells. Anti-Tac(dsFv)-PE38KDEL caused complete regression of tumors with no toxic effects in mice. Because dsFv-immunotoxins are more stable and can be produced with significantly improved yields compared to scFv-immunotoxins, dsFv-immunotoxin may be more useful for therapeutic applications.
Biomimetic Bidirectional Switchable Adhesive Inspired by the Gecko (2013)

The gecko adhesive system has attracted significant attention since the discovery that van der Waals interactions, which are always present between surfaces, are predominantly responsible for their adhesion. The unique anisotropic frictional–adhesive capabilities of the gecko adhesive system originate from complex hierarchical structures and just as importantly, the anisotropic articulation of the structures. Here, by cleverly engineering asymmetric polymeric microstructures, a reusable switchable gecko‐like adhesive can be fabricated yielding steady high adhesion ( ≈ 1.25 N/cm 2 ) and friction ( ≈ 2.8 N/cm 2 ) forces when actuated for “gripping”, yet release easily with minimal adhesion ( ≈ 0.34 N/cm 2 ) and friction ( ≈ 0.38 N/cm 2 ) forces during detachment or “releasing”, over multiple attachment/detachment cycles, with a relatively small normal preload of 0.16 N/cm 2 to initiate the adhesion. These adhesives can also be used to reversibly suspend weights from vertical (e.g., walls), and horizontal (e.g., ceilings) surfaces by simultaneously and judiciously activating anisotropic friction and adhesion forces. This design opens the way for new gecko‐like adhesive surfaces and articulation mechanisms that do not rely on intensive nanofabrication in order to recover the anisotropic tribological property of gecko adhesive pads, albeit with lower adhesive forces compared to geckos.
Real-Time GPS Spoofing Detection via Correlation of Encrypted Signals (2013)

A method for detecting the spoofing of civilian GPS signals has been implemented and successfully tested in a real-time system. GPS signal spoofing is an attack method whereby a third party transmits a signal that appears authentic but induces the receiver under attack to compute an erroneous navigation solution, time, or both. The detection system described herein provides a defense against such attacks. It makes use of correlations between the unknown encrypted GPS L1 P(Y) code signals from two narrow-band civilian receivers to verify the presence or absence of spoofing. One of these receivers is assumed to be at a secure location that is not subject to spoofing. The other receiver is the potential spoofing victim for which the present developments constitute a defense. Successful detection results are presented using a reference receiver in Ithaca, New York, a victim receiver in Austin, Texas, and a spoofer in Austin, Texas. Copyright © 2013 Institute of Navigation.
Blurred/No-Blurred Image Alignment using Kernel Sparseness Prior (2007)

Aligning a pair of blurred and non-blurred images is a prerequisite for many image and video restoration and graphics applications. The traditional alignment methods such as direct and feature-based approaches cannot be used due to the presence of motion blur in one image of the pair. In this paper, we present an effective and accurate alignment approach for a blurred/non-blurred image pair. We exploit a statistical characteristic of the real blur kernel – the marginal distribution of kernel value is sparse. Using this sparseness prior, we can search the best alignment which produces the sparsest blur kernel. The search is carried out in scale space with a coarse-to-fine strategy for efficiency. Finally, we demonstrate the effectiveness of our algorithm for image deblurring, video restoration, and image matting.
Chemical and Physical Characterization of a TiO<sub>2</sub>-Coated Fiber Optic Cable Reactor (1996)

Practical application of metal oxide photocatalysts for the remediation of contaminated wastestreams often requires immobilization of the photocatalyst in a fixed-bed reactor configuration that allows the continu ous use of the photocatalyst by eliminating the need for post-process filtration. A novel optical fiber cable reactor (OFR) is used to transmit UV light to solid-supported TiO2 in order to investigate the photocatalytic degradation of pentachlorophenol (PCP), 4-chlorophenol (4-CP), dichloroacetate (DCA), and oxalate (OX). The distribution of light as a function of fiber diameter and the quantum efficiencies as a function of incident light intensity are investigated. Light propagation down individual fibers is found to increase with increasing fiber diameter. An increased linear transmission of light results in increased quantum efficiencies, while a 2-order of magnitude reduction in incident light intensity results in a 4-fold increase (φ = 0.010−0.042) in quantum efficiency for the degradation of 4-chlorophenol. The rates of degradation of dichloroacetate and oxalate have strong pH de pendencies. Relatively high apparent quantum efficien cies of φ = 0.010, 0.015, 0.08, and 0.17 for PCP, 4-CP, DCA, and OX, respectively, and complete mineralization to CO2, H2O, and HCl are observed in the OFR system.