gebhart/patrepeval huggingface dataset:
A Direct Current Comparator Bridge for High Resistance Measurements (1973)

A dc comparator bridge, which is suitable for measuring resistors from a fraction of an ohm to several megohms with partper-million accuracy or better is described. An analysis of errors which may occur when measuring high-value resistors and methods used for reducing these errors to negligible proportions are included. The bridge can be connected to make either four-terminal or three-terminal measurements. The four-terminal connection is best for measuring low-value resistors. When it was used for measuring high-value resistors, a systematic bridge error was detected, which was found to be primarily due to leakage paths through the insulation, permitting current to bypass one of the measured resistors. This error is avoided by using the three-terminal connection for measuring high-value resistors. The leakage resistance is then in parallel with a low resistance winding rather than one of the measured resistors. The bridge has automatic reversal and a chart recorder output, which continuously indicates the deviation from the set point. The comparator is adjustable in steps of 10-' of full scale, and measurements can be made at ratios up to 11.111/1.
Coupled-quantum-well field-effect resonant tunneling transistor for multi-valued logic/memory applications (1994)

A vertical field-effect resonant tunneling transistor is demonstrated consisting of a triple-barrier, double-well resonant tunneling diode (3bRTD) that can be depleted by the action of side gates. The 3bRTD features a double peak current-voltage characteristic in which the second valley current is less than the first valley current. Combination of the resonant tunneling transistor and a constant current load is shown to yield both binary and ternary logic and memory functions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Multicenter trial of an intraocular hydrogel lens implant (1987)

Several features suggest that hydrogels may have potential advantages as an intraocular lens material. The IOGEL lens is a single piece hydrogel composed of 38% poly HEMA. Clinical experience with the IOGEL lens in Australia has been published, and the safety and efficacy of the lens is currently being investigated in a multicenter trial in Europe, the U.S.A., Canada, Australia, and Japan. This is the first large-scale study of a hydrogel implant. The IOGEL lens clinical study was initiated in May 1986 in Europe, in September 1986 in the U.S.A., and in November 1986 in Canada and Australia. The enrollment progress in May 1987 showed that 501 cases had been implanted in Europe, Canada, and Australia and 100 cases in the U.S.A. The visual acuity outcome is equivalent to that reported in the literature. Patients in the multinational trial achieved 20/40 or better in 86% of cases and in 96% of cases excluding unrelated pathologies. Although hydrogels have only had limited use in the clinical situation, the results of this study suggest that the IOGEL lens is a viable alternative to polymethylmethacrylate lens implants.
A <i>Terminal Flower1</i>-Like Gene from Perennial Ryegrass Involved in Floral Transition and Axillary Meristem Identity (2001)

Control of flowering and the regulation of plant architecture have been thoroughly investigated in a number of well-studied dicot plants such as Arabidopsis, Antirrhinum, and tobacco. However, in many important monocot seed crops, molecular information on plant reproduction is still limited. To investigate the regulation of meristem identity and the control of floral transition in perennial ryegrass (Lolium perenne) we isolated a ryegrass TERMINAL FLOWER1-like gene, LpTFL1, and characterized it for its function in ryegrass flower development. Perennial ryegrass requires a cold treatment of at least 12 weeks to induce flowering. During this period a decrease in LpTFL1 message was detected in the ryegrass apex. However, upon subsequent induction with elevated temperatures and long-day photoperiods, LpTFL1 message levels increased and reached a maximum when the ryegrass apex has formed visible spikelets. Arabidopsis plants overexpressing LpTFL1 were significantly delayed in flowering and exhibited dramatic changes in architecture such as extensive lateral branching, increased growth of all vegetative organs, and a highly increased trichome production. Furthermore, overexpression of LpTFL1 was able to complement the phenotype of the severe tfl1-14 mutant of Arabidopsis. Analysis of the LpTFL1 promoter fused to the UidA gene in Arabidopsis revealed that the promoter is active in axillary meristems, but not the apical meristem. Therefore, we suggest that LpTFL1 is a repressor of flowering and a controller of axillary meristem identity in ryegrass.
An Optimal Orthogonal Decomposition Method for Kalman Filter-Based Turbofan Engine Thrust Estimation (2007)

A new linear point design technique is presented for the determination of tuning parameters that enable the optimal estimation of unmeasured engine outputs, such as thrust. The engine’s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends on knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined that accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least-squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman filter. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters’ ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.
Infrared-Transparent Visible-Opaque Fabrics for Wearable Personal Thermal Management (2015)

Personal cooling technologies locally control the temperature of an individual rather than a large space, thus, providing personal thermal comfort while supplementing cooling loads in thermally regulated environments. This can lead to significant energy and cost savings. In this study, a new approach to personal cooling was developed using an infrared-transparent visible-opaque fabric (ITVOF) that provides passive cooling via the transmission of thermal radiation emitted by the human body directly to the environment. Here, we present a conceptual framework to thermally and optically design an ITVOF. Using a heat transfer model, the fabric was found to require a minimum infrared (IR) transmittance of 0.644 and a maximum IR reflectance of 0.2 to ensure thermal comfort at ambient temperatures as high as 26.1 °C (79 °F). To meet these requirements, an ITVOF design was developed using synthetic polymer fibers with an intrinsically low IR absorptance. These fibers were then structured to minimize IR reflection via weak Rayleigh scattering while maintaining visible opaqueness via strong Mie scattering. For a fabric composed of parallel-aligned polyethylene fibers, numerical finite element simulations predict 1 μm diameter fibers bundled into 30 μm yarns can achieve a total hemispherical IR transmittance of 0.972, which is nearly perfectly transparent to mid- and far-IR radiation. The visible wavelength properties of the ITVOF are comparable to conventional textiles ensuring opaqueness to the human eye. By providing personal cooling in a form amenable to everyday use, ITVOF-based clothing offers a simple, low-cost solution to reduce energy consumption in HVAC systems.
Three-phase AC-to-AC series-resonant power converter with a reduced number of thyristors (1991)

Power pulse modulation with internal frequencies of tens of kHz and suited for multikilowatt power levels is applied to a series-resonant converter (SRC) system for generating synthesized multiphase bipolar waveforms with reversible power flow and low distortion. The high pulse frequency allows the application of the principle of modulation and demodulation for fast system response. The use of an SRC for power transfer and control obtains natural current commutation of the thyristors and the prevention of excessive stresses on components. Switches with bidirectional current conduction and voltage blocking ability are required. The conventional series-resonant AC-AC converter applies a total for 24 antiparallel thyristors. An alternative circuit configuration for the series-resonant AC-AC converter with only 12 thyristors is presented. Use of the converter results in a higher efficiency and lower costs.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
High-temperature superconducting magnets and coils from silver- sheathed Bi-2223 tapes (1993)

The extensive use of neonicotinoid pesticides has led to their widespread presence in the environment, resulting in considerable safety risks to the ecosystem and human health. In this study, we investigated the biotransformation behavior of a cocktail of multiple neonicotinoids and piperonyl butoxide (PBO) synergist <i>in vivo</i> and their potential environmental health risk. It was found that neonicotinoids with a cyano group, such as acetamiprid and thiacloprid, tended to accumulate in liver and spleen tissues, while others with nitro groups (imidacloprid, thiamethoxam, clothianidin, dinotefuran, and nitenpyram) were mostly excreted in urine. In the presence of the synergist PBO, the metabolism of neonicotinoids <i>in vivo</i> changed, mainly through the nitro reduction pathway, while a low abundance of related metabolites was observed in the conventional hydroxylation and demethylation metabolic pathways, due to inhibition of CYP450 enzymes by the synergist. Furthermore, DNA methylation damage <i>in vivo</i> was exacerbated by the induction of hydroxylamine metabolites formed in the intermediate process of neonicotinoid metabolism with the synergistic effect of PBO, which resulted in a higher level of the O<sup>6</sup>-methyldeoxyguanosine (O<sup>6</sup>-medG) biomarker in the liver. Therefore, during the comprehensive evaluation of pesticide environmental risks, attention should be paid not only to the co-exposure mode under real environmental conditions but also to the potential risks of intermediate metabolism and related intermediate metabolites. This study provides a referential strategy and theoretical support for the health risk assessment of co-exposure of chemicals.
Novel platinum initiators for ring‐opening polymerizations (1992)

Abstract Platinum complexes together with compounds containing silicon‐hydrogen bonds comprise a novel class of initiators for the ring‐opening polymerization of a wide variety of heterocyclic compounds including; epoxides, oxetanes and 1,3,5‐trioxane. This paper reports on a preliminary survey of the scope and limitations of these new initiator systems with special emphasis on the ring‐opening polymerization of epoxides. Considerable effort has been directed towards the elucidation of the mechanism of the polymerizations initiated by these systems. The best current evidence suggests that polymerization proceeds by a cationic mechanism. Data is also presented which suggests that platinum metal colloids may function as the active initiating species.
<title>Extraction of multiresolution watermark images for resolving rightful ownership</title> (1999)

Digital watermarking has been recently proposed as the mean for intellectual property right protection of multimedia data. We present some ways to 'visualize' the invisible watermarks, both statistically and perceptually, for proving the ownership. A system which is capable of embedding a good resolution meaningful binary watermark image and later extracting different versions of that watermark image with varying resolutions is proposed. The system has the nice feature that the watermark detector (rather than encoder) is allowed to adaptively choose the trade-off between robustness degree and resolution of the extracted watermark image. It takes advantage of the high spatial correlation of the watermark image and the human visual system's super ability to recognize a correlated pattern to enhance the detection performance. While a statistical technique which can quantify the false alarm detection probability should be considered as a fundamental measure for a valid ownership claim, the ability to extract a meaningful watermark image will greatly facilitate the process of convincing the jury of an ownership claim.
Photoelectrochemical plating of via GaAs FET's (1984)

A new photoelectrochemical (PEC) technique for filling via holes in GaAs FET's with a solid deposit of metal, such as gold, has been developed. Photogenerated electrons reduce solvated Au(CN) <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> -, directly on the FET source pads, allowing narrow straight-walled plasma-etched via holes to be filled without forming voids. The photogenerated holes cause the decomposition of a small amount of the semi-insulating (SI) substrate. With illumination from a 1200-W tungsten-halogen lamp, plating rates of 0.8 µm/min over a 2-in-diam wafer are achieved. The plating rate is insensitive to Au(CN) <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> - concentration in the range 0.01 to 0.15 M. The resulting GaAs FET's show improved mechanical stability and thermal resistance.
Sonic Hedgehog Promotes the Survival of Specific CNS Neuron Populations and Protects These Cells from Toxic Insult<i>In Vitro</i> (1997)

Sonic hedgehog (Shh), an axis-determining secreted protein, is expressed during early vertebrate embryogenesis in the notochord and ventral neural tube. In this site it plays a role in the phenotypic specification of ventral neurons along the length of the CNS. For example, Shh induces the differentiation of motor neurons in the spinal cord and dopaminergic neurons in the midbrain. Shh expression, however, persists beyond this induction period, and we have asked whether the protein shows novel activities beyond phenotype specification. Using cultures derived from embryonic day 14.5 (E14.5) rat ventral mesencephalon, we show that Shh is also trophic for dopaminergic neurons. Interestingly, Shh not only promotes dopaminergic neuron survival, but also promotes the survival of midbrain GABA-immunoreactive (GABA-ir) neurons. In cultures derived from the E15–16 striatum, Shh promotes the survival of GABA-ir interneurons to the exclusion of any other cell type. Cultures derived from E15–16 ventral spinal cord reveal that Shh is again trophic for interneurons, many of which are GABA-ir and some of which express the Lim-1/2 nuclear marker, but it does not appear to support motorneuron survival. Shh does not support the survival of sympathetic or dorsal root ganglion neurons. Finally, using the midbrain cultures, we show that in the presence of MPP + , a highly specific neurotoxin, Shh prevents dopaminergic neuron death that normally would have occurred. Thus Shh may have therapeutic value as a protective agent in neurodegenerative disease.
Design and analysis of a novel electro-optical MEMS gyroscope for navigation applications (2010)

A novel gyroscope design is presented that has potential to reach navigation-grade performance, i.e. bias instability <; 0.01 °/hr and Angle Random Walk (ARW) <; 0.001 °/√hr. The design is based on the incorporation of an optical transduction mechanism used to decouple drive and sense signals, a dual crystalline silicon spring fabrication approach along with a large drive mass and small sense mass to enhance Coriolis displacement.
Low pressure chemical vapor deposition of titanium silicide (1985)

The low pressure chemical vapor deposition (LPCVD) of titanium silicide is reported here for the first time. X-ray diffraction spectra show that the as-deposited films are polycrystalline and TiSi2 is the predominant phase. The as-deposited films had resistivities of 22 to 39 μΩ cm with film thicknesses ranging from 2000 to 15 500 Å, and Si/Ti ratios of 1.8 to 2.3 as determined by Rutherford backscattering spectroscopy. Auger analyses did not detect any impurities such as oxygen and carbon in these films. The LPCVD system consists of a cold wall reactor with the wafer being heated externally by infrared lamps. The reactor is capable of sequential deposition of polycrystalline silicon (polysilicon) and silicide films; moreover, the final annealing step, if necessary, can be performed in situ. Care has been taken to provide a clean environment by using a turbomolecular pump which is capable of keeping the base pressure of the reactor ≤10−7 Torr. We have deposited in situ sequential films of polysilicon and titanium silicide in this system. The silicide films were deposited by reacting SiH4 with TiCl4.
Real-time loop closure in 2D LIDAR SLAM (2016)

Portable laser range-finders, further referred to as LIDAR, and simultaneous localization and mapping (SLAM) are an efficient method of acquiring as-built floor plans. Generating and visualizing floor plans in real-time helps the operator assess the quality and coverage of capture data. Building a portable capture platform necessitates operating under limited computational resources. We present the approach used in our backpack mapping platform which achieves real-time mapping and loop closure at a 5 cm resolution. To achieve realtime loop closure, we use a branch-and-bound approach for computing scan-to-submap matches as constraints. We provide experimental results and comparisons to other well known approaches which show that, in terms of quality, our approach is competitive with established techniques.
Mass sensitivity of thin rod acoustic wave sensors (1996)

Theoretical and experimental investigations of mass sensitivities of thin rod acoustic wave sensor are presented. From the low-frequency approximation of the dispersion equations, explicit forms of the relation describing the mass sensitivity are derived with the consideration of the effects due to elasticity and inertia of the loading layer. The three lowest thin rod acoustic modes are presented. Mass sensing experiments are based on the electrodeposition of loading material on a thin metallic fiber (the thin rod). Copper has been used to load the propagation of acoustic waves in gold fibers. The mass of copper deposited and the phase shift of the acoustical thin rod delay line were monitored simultaneously by a computer. Mass response curves showing the variation in phase due to the mass deposited per unit surface area were then obtained in order to determine the mass sensitivity. Both flexural and extensional wave modes have been excited. Theoretical and experimental results were found to be consistent in both sign and magnitude.
Adaptive decoding for halftone orientation-based data hiding (2008)

Halftone image watermarking techniques that allow automated extraction of the embedded watermark data are useful in a variety of document security and workflow applications. The print-scan process inherent in these applications introduces distortions whose characteristics exhibit a strong spatial dependence on the cover image in which the data is embedded. In this paper, we demonstrate that a characterization of this channel dependence and the use of error correction coding that exploits this dependence via image adaptive decoding offers a significant performance gain. We show this advantage in the specific context of a high rate data embedding method that utilizes orientation modulation for data embedding in clustered dot halftones and moment based detection at the receiver. Channel coding for this scenario utilizing convolutional codes and Repeat Accumulate (RA) codes highlights the advantage of the proposed adaptive decoding methodology. The performance for the RA codes with adaptive decoding also reveals that the resulting system has significantly higher operational rates than prior schemes.
Buoyancy-induced, columnar vortices (2016)

A buoyancy-induced, columnar vortex is deliberately triggered in the unstably stratified air layer over a heated ground plane and is anchored within, and scales with, an azimuthal array of vertical, stator-like planar flow vanes that form an open-top enclosure and impart tangential momentum to the radially entrained air flow. The columnar vortex comprises three coupled primary flow domains: a spiraling surface momentum boundary layer of ground-heated air, an inner thermally driven vertical vortex core and an outer annular flow that is bounded by a helical shear layer and the vanes along its inner and outer edges, respectively, and by the spiraling boundary layer from below. In common with free buoyant columnar (dust devil) vortices that occur spontaneously over solar-heated terrain in the natural environment, the stationary anchored vortex is self-sustained by the conversion of the potential energy of the entrained surface-heated air layer to the kinetic energy of the induced vortical flow that persists as long as the thermal stratification is maintained. This conversion occurs as radial vorticity produced within the surface boundary layer is tilted vertically near the vortex centreline by the buoyant air to form the core of the columnar vortex. The structure and dynamics of the buoyant vortex are investigated using high-resolution stereo particle image velocimetry with specific emphasis on the evolution of the vorticity distributions and their effects on the characteristic scales of the ensuing vortex and on the kinetic energy of the induced flow.
Silicon nitride light pipes for image sensors (2010)

We describe a means for improving the performance of CMOS image sensors using vertical waveguides, known as light pipes. We describe experimental results on the etching of silicon nitride pillars, and the fabrication of photodiodes.
C3 R102G polymorphism increases risk of age-related macular degeneration (2008)

Inflammation has long been suspected to play a role in the pathogenesis of age-related macular degeneration (AMD). Association of variants in the complement factor H (CFH) and complement factor B (CFB) genes has targeted the search for additional loci to the alternative complement cascade, of which C3 is a major component. Two non-synonymous coding polymorphisms within C3, R102G and L314P, have previously been strongly associated with increased risk. These variants are in strong linkage disequilibrium (LD), making the contribution of this locus to AMD even more difficult to ascertain. We sought to determine whether the C3 association resulted primarily from only one of these two variants or from a combined effect of both in 223 families and an independent dataset of 701 cases and 286 unrelated controls. The C3 polymorphisms were in strong LD (r(2) = 0.85), and both were associated in the family-based and case-control datasets (R102G genoPDT P = 0.02, case-control genotypic P = 0.004; L314P genoPDT P = 0.001, case-control genotypic P = 0.04). In conditional analyses in the case-control dataset, R102G remained associated with disease in the L314P risk allele carriers (P = 0.01), but there was no effect of L314P in the R102G risk allele carriers (P = 0.2). After adjusting for age, smoking, CFH Y402H, LOC387715 A69S, and CFB R32Q, the effect of R102G remained strong [P = 0.015, odds ratio = 1.55, 95% confidence interval 1.09 to 2.21, adjusted PAR(population attributable risk) = 0.17]. Therefore, while the strong LD between R102G and L314P makes it difficult to disentangle their individual effects on disease risk, the R102G polymorphism acting alone provides the best model for disease in our data.