gebhart/patrepeval huggingface dataset:
Synthesis of Single-Walled Carbon Nanotubes (C-SWNTs) with a Plasma Torch: A Parametric Study (2004)

In this study, we examine, in detail, the synthesis of single wall carbon nanotubes (C-SWNTs) with a plasma torch, using molecular sources for both carbon and catalyst (typically a carbon-containing gas such as ethylene and ferrocene for the metal catalyst). A comparison of the results obtained by Raman spectroscopy, using two different excitation wavelengths, permitted us to evaluate the importance of certain experimental parameters affecting the quality of the samples; these include the growth temperature of the nanotubes, and the temperature gradient between the flame and the oven. We have found that our method provides results that are qualitatively similar to those obtained using arc and laser techniques: C-SWNTs mixed with catalyst nanoparticles and amorphous carbon. Although the yields of C-SWNTs in the experiments reported here are somewhat lower than other approaches, our method avoids the inconveniences related to the solid phase of the initial material. Observations from scanning electron micrographs (SEM) and transmission electron micrographs (TEM) suggest that the mechanisms involved in the synthesis of the C-SWNTs by our plasma torch are similar to these latter techniques. An industrial-scale process based on a plasma torch could produce large amounts of C-SWNTs with good efficiency, since the present set-up produces continuously 1.5 g/h of deposit while using only 1 kW of power.
When does a camera see rain? (2005)

Rain produces sharp intensity fluctuations in images and videos, which degrade the performance of outdoor vision systems. These intensity fluctuations depend on various factors, such as the camera parameters, the properties of rain, and the brightness of the scene. We show that the properties of rain - its small drop size, high velocity, and low density - make its visibility strongly dependent on camera parameters such as exposure time and depth of field. We show that these parameters can be selected so as to reduce or even remove the effects of rain without altering the appearance of the scene. Conversely, the parameters of a camera can also be set to enhance the visual effects of rain. This can be used to develop an inexpensive and portable camera-based rain gauge that provides instantaneous rain rate measurements. The proposed methods serve to make vision algorithms more robust to rain without any necessity for post-processing. In addition, they can be used to control the visual effects of rain during the filming of movies
ISOLATION OF THREE NOVEL LONG-CHAIN POLYUNSATURATED FATTY ACID Δ9-ELONGASES AND THE TRANSGENIC ASSEMBLY OF THE ENTIRE PAVLOVA SALINA DOCOSAHEXAENOIC ACID PATHWAY IN NICOTIANA BENTHAMIANA1 (2010)

The transgenic aerobic synthesis of long-chain polyunsaturated fatty acids (LC-PUFA) will in most land plants commence with either a Δ6-desaturation or a Δ9-elongation. Numerous Δ6-desaturases have been characterized, but only one Δ9-elongase has been reported in peer-reviewed literature. In the present study, we describe the isolation of three additional Δ9-elongases from the class Haptophyceae and demonstrate that the Δ9-elongase group contains highly conserved regions, which differentiate them from other ELO-type elongases. One such important difference is the presence of an LQxFHH motif instead of the usual LHxYHH motif, a feature that should simplify further gene discovery efforts in this group of enzymes. Moreover, the identification of the Pavlova salina (N. Carter) J. C. Green Δ9-elongase completes the isolation of the entire P. salina docosahexaenoic acid (DHA) pathway, and we describe the assembly of this pathway in Nicotiana benthamiana. Finally, we comment on possible explanations for the widespread presence of the Δ6-desaturated fatty acid stearidonic acid (SDA, 18:4Δ6,9,12,15) in the plastidial lipids of organisms using the Δ9-elongase pathway.
Enhancing the Angular Sensitivity of Plasmonic Sensors Using Hyperbolic Metamaterials (2016)

Surface plasmon resonance (SPR) sensors operate mainly on prism and grating coupling techniques, with spectral and angular scans being the two major interrogation schemes. Among them, the angular scan technique has several advantages including higher measurement precision owing to its higher signal-to-noise ratio. The currently available SPR sensor arrangements provide a maximum angular sensitivity of 500°-600° per RIU. Here, we report the study of grating coupled-hyperbolic metamaterial (GC-HMM) sensors with high angular sensitivity. The experimental studies show extraordinary angular sensitivities from visible to near infrared (NIR) wavelengths by exciting bulk plasmon polaritons associated with hyperbolic metamaterials, with a maximum of 7000° per RIU. This angular-scan plasmonic biosensor has been used for the detection of low molecular weight biomolecules such as biotin (244 Da) and high molecular weight macromolecules such as Cowpea mosaic virus (CPMV, 5.6 × 10<sup>6</sup> Da) at ultralow concentrations. The miniaturized sensing device can be integrated with microfluidic systems for the development of next-generation biosensors for lab-on-a-chip and point-of-care applications.
Multirotor dynamics based online scale estimation for monocular SLAM (2019)

This paper proposes a novel method to estimate the scale online for monocular SLAM. Unlike conventional scale estimation methods that require a metric sensor such as an IMU and apriori knowledge of its biases, this approach estimates the scale online by solely using the monocular camera and multirotor dynamics model in an extended Kalman Filter framework. Further, we discuss the observability of scale and theoretically show that the scale becomes observable when multirotor dynamics model and monocular vision are used in conjunction. We validate our proposition with extensive experimentation on the local as well as on the standard datasets and compare the same with other state of the art methods.
EUV mask development: material and process (2002)

Extreme ultraviolet lithography (EUVL) is one of the most promising technologies for wafer feature sizes of below 50nm. The illumination wavelength will be approximately 13.5nm and consequently no transmissive optics can be used for this soft X-ray light. For several years intensive research work has been performed in different programs mainly through EUV-LLC, ASET and PREUVE. This has resulted in providing solutions for the most critical tasks of EUVL - powerful sources, defect free mask blanks and environmentally stable optics of high reflectivity. During the development with EUV-LLC an engineering test stand for illumination has been built which will be a powerful tool for the development for EUVL masks. We have studied the patterning of a EUVL mask for process development and repair tests. The material was a standard Cr absorber (as used in production) and a SiO<SUB>2</SUB> buffer layer. The process investigation was focused on the dry etch stop behaviour of the etch processes and also on cleaning issues. The mask concept favoured today for EUVL masks is very similar to the masks used in production; consequently most work is performed on Cr as the absorber material and SiO<SUB>2</SUB> as the buffer material. From results presented in recent years we can surmise that Cr and TaN are at present the most promising candidates as absorber materials. However it is also known that it will be very difficult to develop an etch-bias free process for Cr. In this paper we shall present our results detailing the etch properties of Ta and TaN as an absorber material. TaN is shown to be a promising absorber material. In addition, the impact of mask properties on placement and bow has been investigated with finite element calculations.
Polarization diversity improves RSSI based location estimation for wireless sensor networks (2009)

Signal strength based wireless location estimation suffers accuracy in indoor environments since the distance to RSSI (received signal strength indicator) function is not monotonic and gives multiple distance estimates for a specific signal strength value. In this paper an advancement of the existing estimation techniques is proposed by establishing the use of polarization diversity in getting robust location estimation. The measurements done in indoor environment clearly bring to fore the need to compute the signal strengths on different polarization vectors of radiated E-field, for prediction of location of wireless communication nodes with a better accuracy. Experiments conducted for both line-of sight and non-line of sight cases show that an optimal weighted sum of the respective signal strengths for different polarizations lead to a monotonic path loss expression which can be used for predicting the locations even with minimal initial training sequence. This novel approach enables precision indoor localization with a minimal set of measurements by exploiting the easily available RSSI information.
Angle Random Walk Minimization for Frequency Modulated Gyroscopes (2019)

Compared to amplitude modulated gyroscopes, frequency modulated (FM) gyroscopes have demonstrated excellent long-term stability. A notable limitation with FM gyroscopes is FM operation can decrease short-term stability. Short-term stability is typically quantified via angle random walk (ARW). This work presents an FM gyroscope ARW minimization method. As the measured and predicted values of minimized ARW are in agreement, this work provides a means to account for the competing effects associated with amplitude and frequency stability.
A comparison study of regularization techniques on the theoretical design of phased array RF coils in MRI (2008)

In MRI engineering, regularization techniques can be effectively used to solve ill-posed problems in electromagnetics, such as the inverse design of phased array RF coils. In this work, a comparison on various regularization methods which are employed to numerically reconstruct a divergence-free cylindrical surface of current distribution is investigated. It is found that a coil current pattern is very sensitive to the modes of the basis function describing the current densities on the coil surface; and iterative regularization techniques generally produce better B(1) field profiles compared with direct approaches.
Analysis of Weighted Fan-out/Fan-in Volume Holographic Interconnections (1992)

Volume holography has often been proposed as an interconnection technology for photonic neural network implementations [1] because it appears to potentially meet the critical requirements of providing both large numbers of interconnections and a weighted fan-out/fan-in topology. The feasibility of using volume holograms for large-scale weighted fan-out/fan-in interconnection applications depends in part on the fidelity with which the interconnection weights can be implemented, and on the throughput that can be achieved in the volume holographic interconnection system. In addition, an important implementation issue is the number of exposures required to record a particular interconnection configuration because this can impact the total writing time and required exposure schedule.
Adapalene-benzoyl peroxide, a unique fixed-dose combination topical gel for the treatment of acne vulgaris: a transatlantic, randomized, double-blind, controlled study in 1670 patients (2009)

Adapalene-BPO provides significantly greater and synergistic efficacy and a faster onset of action with an acceptable safety profile in the treatment of acne vulgaris when compared with the corresponding vehicle and the adapalene and BPO monotherapies.
High-sensitivity, high-resolution, high-thermal-resistant negative electron x-ray resist (1981)

A novel negative-working electron/x-ray resist with high sensitivity, high resolution, and good dry etch resistance was obtained by the free radical copolymerization of an unsaturated methacrylate and a hydroxy alkyl methacrylate. Depending on the copolymer ratio, sensitivity of at least 0.2 μC/cm2 was achieved with 10 keV electrons in most cases with polymers with a ?w well below 100 000. Resolution of 1.0 μm line and space was obtained from a 0.95-μm-thick resist by either direct e-beam writing or by exposure to soft x-rays through a mask. The sensitivity to 7 Å tungsten M lines was 9 mJ/cm2 and the contrast was ∠1.3. An aspect ratio of ∠2 was obtained with isolated submicron lines 7000 Å thick. The resist had good resistance to both chemical and dry etching. The plasma etch resistance was at least twice that of PMMA.
Multiplexing radiography using a carbon nanotube based x-ray source (2006)

Speed and temporal resolution are critical for tomographic imaging of objects in rapid motion. Current x-ray scanners record images sequentially in the time domain. The serial approach limits their performance and demands increasingly high x-ray peak power and gantry speed. We have developed a multipixel carbon nanotube based field emission x-ray source that produces spatially and temporally modulated radiations. Using this device we show the feasibility of multiplexing radiography that enables simultaneous collection of multiple projection images using frequency multiplexing. A drastic increase of the speed and reduction of the x-ray peak power are achieved without compromising the imaging quality.
Performance of 1 Meter Straw Detector for High Rate Neutron Imaging (2006)

Instrument requirements at the newly commissioned Spallation Neutron Source call for large area detectors that can sustain rates up to <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> 7 neutrons/s and millimeter-level spatial resolution. Although <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> He pressurized area detectors can provide good spatial resolution, sensitivity and gamma ray discrimination, this technology cannot support the required rates without further development. We propose a detector technology based on thin-walled straws, lined with enriched boron carbide ( <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> C. A panel detector consisting of several thousand close-packed individual straws, which are read out independently, can easily support high event rates. We present test results for a sub-scale 100times4 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> prototype detector, consisting of three 50-straw array modules. Each straw in the array has a diameter of 4 mm and a length of 1 m. Tests conducted in a thermal neutron beam focused on the count rate capability of the detector and the effect of high neutron rates and a high gamma ray flux on spatial resolution. Results showed that the detector can maintain a 7times4 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> resolution up to an integral rate of 40,000 cps, and a gamma ray flux of 1000 mrem/hr.
Development of a quadrupole mass spectrometer using the second stable zone in Mathieu’s stability diagram (1991)

A quadrupole mass spectrometer (QMS) utilizing the second stable zone in Mathieu’s stability diagram was developed. The system performance was experimentally compared with the conventional QMS using the first stable zone. The peak shapes obtained were sharper and the tail components arising from adjacent peaks were less than those of the conventional QMS, although the analyzable range was limited to lower mass and the attenuation in sensitivity was about 1/50. This improved QMS is usable in detecting very small peaks adjoining large ones.
<i>In situ</i> thin film and multilayer structural characterization using x-ray fluorescence induced by reflection high energy electron diffraction (2009)

The angular dependence of the x-ray fluorescence from Y and Mn inner K shell ionization induced by a grazing angle incident electron beam in several multilayered Y/Mn structures was analyzed using the distorted-wave approximation. Estimates of structural parameters, thickness, and interfacial roughness were obtained from the x-ray fluorescence measured in the total reflection regime and compared with ex situ x-ray reflectivity results. Although the sensitivity to the surface and interface roughness was relatively low, the thickness values for both single and buried layers were in good agreement with the x-ray reflectivity measurements.
Efficient encoding of dense motion fields for motion-compensated video compression (2003)

A dense motion field provides a number of advantages over the traditional block-based motion models in interpreting the temporal correlation between video frames. However, until now, its application to motion-compensated video coding has been limited due to the inhibitive rate needed to encode the motion field. We present an efficient scheme for encoding a dense motion field which makes it possible to apply it in a forward motion-compensated video coding framework. A multi-scale motion field is first estimated to represent the motion at different scales. This full multi-scale motion field is then reduced adaptively by a tree pruning algorithm, resulting in a motion field that is represented at different scales from region to region. The pruned motion vector components are coded by a backward context-based arithmetic coding scheme. The motion vector encoding scheme is then incorporated into a complete video codec in which a much greater percentage of the overall bit-rate is allocated to the motion information (+30%). Simulations show that such a system provides substantial improvements over standard block-based coders.
Combinatorial-mold imprint lithography: A versatile technique for fabrication of three-dimensional polymer structures (2006)

A two-step fabrication technique based on nanoimprint lithography is described for the fabrication of three-dimensional micro- and nanostructures. By combining simple two-dimensional geometries from two molds, complex and useful three-dimensional structures are obtained. The careful selection of mold geometries constitutes a simplified and efficient approach toward building up desirable three-dimensional structures without resorting to the use of a sacrificial process or components. Three-dimensional structures fabricated for a variety of specific applications are presented using both thermoplastic and cross-linked polymer materials.
A Supramolecular Vaccine Platform Based on α-Helical Peptide Nanofibers (2017)

A supramolecular peptide vaccine system was designed in which epitope-bearing peptides self-assemble into elongated nanofibers composed almost entirely of alpha-helical structure. The nanofibers were readily internalized by antigen presenting cells and produced robust antibody, CD4+ T-cell, and CD8+ T-cell responses without supplemental adjuvants in mice. Epitopes studied included a cancer B-cell epitope from the epidermal growth factor receptor class III variant (EGFRvIII), the universal CD4+ T-cell epitope PADRE, and the model CD8+ T-cell epitope SIINFEKL, each of which could be incorporated into supramolecular multi-epitope nanofibers in a modular fashion.
Gaussian mixture models for classification of neonatal seizures using EEG (2010)

A real-time neonatal seizure detection system is proposed based on a Gaussian mixture model classifier. The system includes feature transformation techniques and classifier output postprocessing. The detector was evaluated on a database of 20 patients with 330 h of recordings. A detailed analysis of the choice of parameters for the detector is provided. A mean good detection rate of 79% was obtained with only 0.5 false detections per hour. A thorough review of all misclassified events was performed, from which a number of patterns causing false detections were identified.
58. Engineered Cas9 Variants with Novel PAM Specificities Expand the Targeting Range of CRISPR/Cas Nucleases (2015)

Specificity and targeting range are important considerations when selecting an engineered nuclease platform for functional studies or therapeutic applications. The use of CRISPR/Cas9 to edit virtually any genome has enabled researchers to rapidly knock out genes or to introduce precise genomic changes. A number of studies have explored and improved the specificity of the CRISPR/Cas9 platform but the targeting range remains limited to certain sequences. The most widely used Cas9 from Streptococcus pyogenes (SpCas9) recognizes a protospacer adjacent motif (PAM) of the form NGG, a constraint that restricts the range of sequences that can be edited. Combined with the 5’ nucleotide requirement for guide-RNA expression from a polIII promoter, this restriction can be limiting particularly when one is using CRISPR/Cas9 nucleases to introduce precise mutations by homology-directed repair (HDR), which requires that double-strand breaks be introduced very closely to the site of sequence alteration. To address this challenge, we developed a heterologous genetic system that enabled us to rapidly screen libraries of Cas9 clones and identify variants with distinct cleavage specificities. Using this technology, we identified and optimized two different Cas9 variants that recognize novel PAMs. We demonstrate that these variants enable targeting of sites with non-canonical PAM sequences that were previously inaccessible with wild-type SpCas9, more than doubling the total range of sequences that can be edited by HDR and by error-prone non-homologous end-joining (NHEJ). We demonstrate that these variants can robustly modify endogenous genes in human cells and that they are compatible with previously described specificity improvements to SpCas9 such as truncated gRNAs. Furthermore, we also show Cas9 nucleases from other bacterial species such as Staphylococcus aureus and Streptococcus thermophilus can also be assessed for activity in our heterologous genetic system, suggesting that these alternative Cas9s might also be modified in their PAM specificities using the same approach we undertook with SpCas9. These orthogonal Cas9 nucleases offer the advantage of being substantially smaller in size than SpCas9, an important factor when considering packaging limits for viral delivery of CRISPR/Cas9 components. Taken together, our results more than double the targeting range of CRISPR/Cas9 nuclease platform and improve the prospects for translation of these reagents to clinical settings.