gebhart/patrepeval huggingface dataset:
Hybrid Axial and Cross-Flow Fan Propulsion for Transonic Blended Wing Body Aircraft (2012)

Ideally, standard fan/engine designs can directly be embedded within the airframe of a vehicle. Unfortunately, doing so causes both performance penalties and structural challenges due to boundary layer flow ingested into the propulsors. For the present design concept, a dual-propulsion axial fan (AF) and cross-flow fan (CFF) system is investigated. This system provides the excellent efficiency of the axial fan, but with the benefit of the cross-flow fan system providing boundary layer flow mitigation. The purpose of this research was to develop the necessary computational tools to analyze this configuration, and then to show that the combined propulsor solution has performance benefits over the single axial fan system. Using both 2D and 3D CFD simulations, axial fan compression efficiency improvements of up to 2.5% were shown when the CFF propulsor was included. Also, the CFD data showed significant changes in the flow field due to the inclusion (or exclusion) of the distributed propulsors, demonstrating that it is impossible to segregate the airframe force calculations from those for the individual fans, thus necessitating a coupled airframe and propulsion approach to the design of such a vehicle.
Improvements in the modulation amplitude of submicron gratings produced in <i>n</i>-InP by direct photoelectrochemical etching (1985)

The modulation amplitude of gratings produced by maskless etching techniques decreases rapidly at spatial frequencies &gt;500 mm−1. This has limited the usefulness of these techniques for producing the submicron gratings required for distributed feedback lasers. We report improvements as large as a factor of 100 in the direct photoelectrochemical (PEC) etching of gratings in n-InP which were accomplished by changing the composition and concentration of the electrolyte solutions. Measurements on the PEC etching characteristics of n-InP in HF, HCl, HBr, and H2SO4 solvents are presented.
Phase noise in oscillators: a unifying theory and numerical methods for characterization (2000)

Phase noise is a topic of theoretical and practical interest in electronic circuits, as well as in other fields, such as optics. Although progress has been made in understanding the phenomenon, there still remain significant gaps, both in its fundamental theory and in numerical techniques for its characterization. In this paper, we develop a solid foundation for phase noise that is valid for any oscillator, regardless of operating mechanism. We establish novel results about the dynamics of stable nonlinear oscillators in the presence of perturbations, both deterministic and random. We obtain an exact nonlinear equation for phase error, which we solve without approximations for random perturbations. This leads us to a precise characterization of timing jitter and spectral dispersion, for computing of which we have developed efficient numerical methods. We demonstrate our techniques on a variety of practical electrical oscillators and obtain good matches with measurements, even at frequencies close to the carrier, where previous techniques break down. Our methods are more than three orders of magnitude faster than the brute-force Monte Carlo approach, which is the only previously available technique that can predict phase noise correctly.
Polymers for Chemical Sensors Using Hydrosilylation Chemistry (2001)

Sorbent and functionalized polymers play a key role in a diverse set of fields, including chemical sensors, separation membranes, solid phase extraction techniques, and chromatography. Sorbent polymers are critical to a number of sensor array or ''electronic nose'' systems. The responses of the sensors in the array give rise to patterns that can be used to distinguish one compound from another, provided that a sufficiently diverse set of sensing materials is present in the array. Figure 1 illustrates the concept of several sensors, each with a different sensor coating, giving rise to variable responses to an analyte that appear as a pattern in bar graph format. Using hydrosilylation as the bond-forming reaction, we have developed a versatile and efficient approach to developing sorbent polymers with diverse interactive properties for sensor applications. Both the chemical and physical properties of these polymers are predictable and tunable by design.
Metal–dielectric filters for solar–blind silicon ultraviolet detectors (2015)

We report on the fabrication of metal-dielectric thin film stacks deposited directly onto silicon substrates for use as ultraviolet bandpass filters. Integration of these filters onto silicon improves the admittance matching of the structure when compared to similar designs fabricated on transparent substrates, leading to higher peak transmission or improved out-of-band rejection if used with a Si-based sensor platform. Test structures fabricated with metallic Al and atomic layer deposited Al2O3 were characterized with spectroscopic ellipsometry and agree well with optical models. These models predict transmission as high as 90% the spectral range of 200-300 nm for simple three-layer coatings.
Evolution of Basal Plane Dislocations during 4H-SiC Epitaxial Growth (2008)

The evolution of basal plane dislocations (BPDs) in 4H-SiC epitaxy during its growth is investigated by using two types of interrupted growth in conjunction with ultraviolet photoluminescence (UVPL) imaging of the dislocations. For the first, each epitaxial growth was stopped after 10-20 μm and a UVPL map was collected. For the second, changing the gas flow interrupted the growth and the BPDs were imaged at the end. The first sequence made it possible to track the formation of half-loop arrays and show that they arise from BPDs that glide perpendicular to the offcut direction. For both types, each interruption causes between 30 – 50% of the BPDs to be converted to threading edge dislocations (TEDs). This result suggests that using interrupted growth may be an alternate method to producing epitaxial layers with low BPD concentration.
Biodiversity of lactococcal bacteriophages isolated from 3 Gouda-type cheese-producing plants (2013)

This study reports on the identification and characterization of bacteriophages isolated from cheese-production facilities that use undefined, mixed starter cultures. Phage screening was carried out on whey samples isolated from 3 factories, 2 utilizing one particular undefined starter mixture and 1 utilizing another undefined starter mixture. Phage screening was carried out using 40 strains isolated from the 2 mixed starter cultures, and phages were profiled using host range, electron microscopy, multiplex PCR, and DNA restriction analysis. Twenty distinct lactococcal phages were identified based on host range and DNA restriction profiles, all belonging to the 936-type phage species. Nineteen of these phages were found to be able to infect both recognized subspecies of Lactococcus lactis. Restriction of phage DNA isolated using a newly developed guanidinium thiocyanate disruption method showed that the genomes of the 20 isolated phages were between 26 and 31 kb in size. It is evident from this study that the use of mixed starters creates an ideal environment for the proliferation of different phages with slightly varying host ranges. Furthermore, in this environment, members of the 936-type phage species clearly dominated the phage population.
Cooperative Carbon Dioxide Capture in Diamine-Appended Magnesium–Olsalazine Frameworks (2023)

Diamine-appended Mg<sub>2</sub>(dobpdc) (dobpdc<sup>4-</sup> = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) metal-organic frameworks have emerged as promising candidates for carbon capture owing to their exceptional CO<sub>2</sub> selectivities, high separation capacities, and step-shaped adsorption profiles, which arise from a unique cooperative adsorption mechanism resulting in the formation of ammonium carbamate chains. Materials appended with <i>primary</i>,<i>secondary</i>-diamines featuring bulky substituents, in particular, exhibit excellent stabilities and CO<sub>2</sub> adsorption properties. However, these frameworks display double-step adsorption behavior arising from steric repulsion between ammonium carbamates, which ultimately results in increased regeneration energies. Herein, we report frameworks of the type diamine-Mg<sub>2</sub>(olz) (olz<sup>4-</sup> = (<i>E</i>)-5,5'-(diazene-1,2-diyl)bis(2-oxidobenzoate)) that feature diverse diamines with bulky substituents and display desirable single-step CO<sub>2</sub> adsorption across a wide range of pressures and temperatures. Analysis of CO<sub>2</sub> adsorption data reveals that the basicity of the pore-dwelling amine─in addition to its steric bulk─is an important factor influencing adsorption step pressure; furthermore, the amine steric bulk is found to be inversely correlated with the degree of cooperativity in CO<sub>2</sub> uptake. One material, ee-2-Mg<sub>2</sub>(olz) (ee-2 = <i>N</i>,<i>N</i>-diethylethylenediamine), adsorbs >90% of the CO<sub>2</sub> from a simulated coal flue stream and exhibits exceptional thermal and oxidative stability over the course of extensive adsorption/desorption cycling, placing it among top-performing adsorbents to date for CO<sub>2</sub> capture from a coal flue gas. Spectroscopic characterization and van der Waals-corrected density functional theory calculations indicate that diamine-Mg<sub>2</sub>(olz) materials capture CO<sub>2</sub> via the formation of ammonium carbamate chains. These results point more broadly to the opportunity for fundamentally advancing materials in this class through judicious design.
Enumeration and characterization of circulating multiple myeloma cells in patients with plasma cell disorders (2017)

We have developed an automated assay to enumerate and characterize circulating multiple myeloma cells (CMMC) from peripheral blood of patients with plasma cell disorders. CMMC show expression of genes characteristic of myeloma and fluorescence in situ hybridisation results on CMMC correlated well with bone marrow results. We enumerated CMMC from over 1000 patient samples including separate cohorts of newly diagnosed multiple myeloma and high/intermediate risk smouldering multiple myeloma (SMM) with clinical follow-up data. In newly diagnosed myeloma patient samples, CMMC counts correlated with other clinical measures of disease burden, including the percentage of bone marrow plasma cells, serum M protein, and International Staging System stage. CMMC counts decreased significantly from baseline when a remission was achieved due to treatment (P < 0·001). Patients with CMMC counts ≥100 at remission showed reduced survival relative to patients with CMMC counts <100. Patients with undetectable CMMC in remission showed further overall survival benefits. In the SMM cohort, there was a trend toward higher CMMC in patients with higher-risk myeloma precursor states. Significantly higher CMMC counts were observed between intermediate/high risk SMM patients that progressed versus those without progression (P = 0·031). CMMC allow a non-invasive means of monitoring tumour biology and may have use as a prognostic test for patients with plasma cell disorders.
Effect of conductivity and dielectric constant on the modulation voltage for optoelectronic devices based on nonlinear optical polymers (2001)

Presented is the effect of using various cladding materials with different conductivities and dielectric constants on the applied voltage for optoelectronic (OE) devices based on nonlinear optical (NLO) polymers. Using a conductive polymer, we have demonstrated a 3 to 13 times increase in the effective electro-optic (EO) coefficient of electrode- poled NLO polymers, compared to using passive polymer claddings. We have achieved the lowest poling voltage to date for maximum EO coefficient, 300 V, for a two-layer waveguide structure consisting of a 2-?m- thick NLO polymer layer and a 2-?m-thick conductive cladding layer. The dielectric constants of both the NLO polymer core and passive polymer cladding materials used for conventional polymer-based integrated optic devices are typically very similar in magnitude. This suggests that only a small fraction of the applied modulation voltage is reaching the NLO polymer core layer, requiring 4 to 5 times higher modulation voltage than the desired V?. We have demonstrated a factor-of-2 decrease in the modulation voltage using the same conductive polymer, due to its possessing a much higher dielectric constant than the core material at the modulation frequency tested. The results show promise for shorter, lower-operating-voltage devices.
OC095: Synthetic aperture imaging in medical ultrasound (2004)

Synthetic Aperture (SA) ultrasound imaging is a relatively new and unexploited imaging technique. The images are perfectly focused both in transmit and receive, and have a better resolution and higher dynamic range than conventional ultrasound images. The blood flow can be estimated from SA images with high precision, and the imaging is easily extended to real-time 3D scanning. This paper presents the work done at the Center for Fast Ultrasound Imaging in the area of SA imaging. Three areas that benefit from SA imaging are described. Firstly a preliminary in-vivo evaluation comparing conventional B-mode imaging with STAI is presented. In this study 7 male volunteers were scanned abdominally, and resulting images were compared by 3 medical doctors using randomized blinded presentation. All 3 examiners scored a significant better image quality in STA images (P-value < 0.001). Secondly the performance of a flow estimator is evaluated in a flow rig and in-vivo scans are shown. The method uses beamforming along the flow direction, which has the advantage that the signals are strongly correlated. A 7.5 MHz commercial transducer was used to measure the flow in a plastic tube with an entrance length of 1 m an a diameter of 17 mm. The velocity profile was measured for flow angles of 60 and 90 degrees. The standard deviation of the measurements was 0.36% (0.65 mm/s) for 60 degrees and 1.2% (2.1 mm/s) for the purely transverse flow. Finally the application of SA imaging to real-time 3D scanning is presented. The method uses a combination of a rotating transducer and STA imaging. Due to the rotation of the transducer, a 2D array is synthesized. Images from point targets in a tissue mimicking phantom show that the −6 dB resolution is 1.5 deg. in both elevation and azimuth planes, and that the side-lobes are 50 dB below the peak. The system can potentially acquire 10 fully focused volumes per second.
Summary-based routing for content-based event distribution networks (2004)

Providing scalable distributed Web-based eventing services has been an important research topic. It is desirable to have an effective mechanism for the servers to summarize their filters for in-network preprocessing in order to optimize system performance. In this paper, we propose a summary-based routing mechanism and introduce the notion of imprecise summaries to provide a trade-off between routing overhead and event traffic. Our system uses similarity-based filter clustering to reduce overall event traffic and performs self-tuning summary precision selection to optimize throughput. We have implemented summary-based routing on top of an XML-based infrastructure that closely follows the proposed Web services standards. Measurements from the actual implementation validate our analytical and simulation results, and demonstrate the practical benefits of the proposed techniques.
Erbium fiber laser–pumped continuous-wave microchip Cr^2+:ZnS and Cr^2+:ZnSe lasers (2002)

Efficient continuous-wave (cw) lasing of Cr(2+):ZnS and Cr(2+):ZnSe crystals in external hemispherical cavities and in a microchip configuration under Er-fiber-laser pumping at room temperature are reported. The key result is what is believed to be the first successful demonstration of cw Cr(2+):ZnS and Cr(2+):ZnSe microchip lasers with maximum output powers of 63 and 100 mW at 2320 and 2520 nm, with slope efficiencies of 53% and 20%, respectively.
The Catalytic Subunit of <i>Dictyostelium</i> cAMP‐Dependent Protein Kinase (1997)

The C subunit of Dictyostelium cAMP-dependent protein kinase (PKA) is unusually large (73 kDa) due to the presence of 330 amino acids N-terminal to the conserved catalytic core. The sequence following the core, including a C-terminal -Phe-Xaa-Xaa-Phe-COOH motif, is highly conserved. We have characterized the catalytic activity and stability of C subunits mutated in sequences outside the catalytic core and we have analyzed their ability to interact with the R subunit and with the heat-stable protein-kinase inhibitor PKI. Mutants carrying deletions in the N-terminal domain displayed little difference in their kinetic properties and retained their capacity to be inhibited by R subunit and by PKI. In contrast, the mutation of one or both of the phenylalanine residues in the C-terminal motif resulted in a decrease of catalytic activity and stability of the proteins. Inhibition by the R subunit or by PKI were however unaffected. Sequence-comparison analysis of other protein kinases revealed that a -Phe-Xaa-Xaa-Phe- motif is present in many Ser/Thr protein kinases, although its location at the very end of the polypeptide is a particular feature of the PKA family. We propose that the presence of this motif may serve to identify isoforms of protein kinases.
Enhanced discrimination of DNA molecules in nanofluidic channels through multiple measurements (2012)

Nanofluidic sensing elements have been the focus of recent experiments for numerous applications ranging from nucleic acid fragment sizing to single-molecule DNA sequencing. These applications critically rely on high measurement fidelity, and methods to increase resolution are required. Herein, we describe fabrication and testing of a nanochannel device that enhances measurement resolution by performing multiple measurements (>100) on single DNA molecules. The enhanced measurement resolution enabled length discrimination between a mixture of λ-DNA (48.5 kbp) and T7 DNA (39.9 kbp) molecules, which were detected as transient current changes during translocation of the molecules through the nanochannel. As long DNA molecules are difficult to resolve quickly and with high fidelity with conventional electrophoresis, this approach may yield potentially portable, direct electrical sizing of DNA fragments with high sensitivity and resolution.
Electrostatic Endothelial Cell Seeding Technique for Small Diameter (&lt; 6 mm) Vascular Prostheses: <i>In Vitro</i> Evaluation (1996)

Abstract The occurrence of vascular disease due to atherosclerosis interrupts the normal function (delivery of blood flow) and physiology of the blood vessels. One treatment for this condition is to by-pass the occluded section using a non-essential, autologous vessel (Saphenous vein) or a synthetic graft (Dacron or e-PTFE). Synthetic graft materials as by-pass grafts prove to be problematic when using the small diameter (&lt; 6 mm) diameter grafts.
Very high temperature silicon on silicon pressure transducers (1992)

A silicon on silicon pressure sensor has been developed for use at very high temperatures (1000 F). The design principles used to fabricate the pressure sensor are outlined and results are presented of its high temperature performance.
Fluorine-cycle incandescent lamps (1977)

Tungsten-halogen incandescent lamps containing either bromine or iodine as the halogen are commercially available and exhibit a life or light output superior to that of nonhalogen lamps. To further increase the life of this kind of lamp, fluorine was tried as the halogen. By adding bromotrifluoromethane (CBrF3) to the fill gas, lamp life more than twice that of lamps containing bromine alone was achieved. To avoid deleterious side effects of the fluorine cycle, a small amount of oxygen is required in the lamp. This oxygen can be supplied simply by omitting some of the processing steps normally used to remove residual oxygen.
Partial Aortic Occlusion and Cerebral Venous Steal (2011)

Acute ischemic stroke therapy emphasizes early arterial clot lysis or removal. Partial aortic occlusion has recently emerged as an alternative hemodynamic approach to augment cerebral perfusion in acute ischemic stroke. The exact mechanism of cerebral flow augmentation with partial aortic occlusion remains unclear and may involve more than simple diversion of arterial blood flow from the lower body to cerebral collateral circulation. The cerebral venous steal hypothesis suggests that even a small increase in tissue pressure in the ischemic area will divert blood flow to surrounding regions with lesser tissue pressures. This may cause no-reflow (absence of flow after restoration of arterial patency) in the ischemic core and "luxury perfusion" in the surrounding regions. Such maldistribution may be reversed with increased venous pressure titrated to avoid changes in intracranial pressure. We propose that partial aortic occlusion enhances perfusion in the brain by offsetting cerebral venous steal. Partial aortic occlusion redistributes blood volume into the upper part of the body, manifested by an increase in central venous pressure. Increased venous pressure recruits the collapsed vascular network and, by eliminating cerebral venous steal, corrects perifocal perfusion maldistribution analogous to positive end-expiratory pressure recruitment of collapsed airways to decrease ventilation/perfusion mismatch in the lungs.
Time encoded fast neutron/gamma imager for large standoff SNM detection (2011)

Passive detection of special nuclear material (SNM) at long range or under heavy shielding can only be directly achieved by observing the penetrating neutral particles that it emits: gamma rays and neutrons in the MeV energy range. The ultimate SNM standoff detector system would have sensitivity to both gamma and neutron radiation, a large area and high efficiency to capture as many signal particles as possible, and good discrimination against background particles via directional and energy information. We are exploring the use of time-modulated collimators that may lead to practical gamma-neutron imaging detector systems that are highly efficient with the potential to exhibit simultaneously high angular and energy resolution. We will present results from a large standoff SNM detection demonstration using a prototype high sensitivity time encoded modulation imager.
A High-Speed Large-Range Tip-Tilt-Piston Micromirror Array (2016)

This paper introduces the design of a high fill-factor (>99%) micromirror array that consists of 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> hexagonal mirrors, which are expected to each independently achieve continuous, closed-loop control of three degrees of freedom (DOFs)-tip, tilt, and piston-over large ranges (> ± 10° rotation and > ± 30μm translation) at high speeds (~45 kHz for a 1° amplitude of rotational oscillation). The flexure topology of this array is designed using the freedom, actuation, and constraint topologies synthesis approach, which utilizes geometric shapes to help designers rapidly consider every flexure topology that best achieves a desired set of DOFs driven by decoupled actuators. The geometry of this array's comb-drive actuators is optimized in conjunction with the geometry of the system's flexures using a novel approach. The analytical models underlying this approach are verified using finite-element analysis and validated using experimental data. The capabilities of this new mirror array will enable, or significantly improve, the performance of a variety of high-impact optical technologies such as advanced optical switches, spatial-light modulators, displays, and laser steering or scanning devices.