gebhart/patrepeval huggingface dataset:
Projection reduction exposure with variable axis immersion lenses: Next generation lithography (1999)

Projection reduction exposure with variable axis immersion lenses (PREVAIL) represents the high throughput e-beam projection approach to NGL, which IBM is pursuing in cooperation with Nikon as alliance partner; another e-beam projection approach is SCALPEL pursued by Lucent Technologies. This article discusses the challenges and accomplishments of the PREVAIL project. It will focus on the results obtained with the proof of concept (POC) system. This system was developed to demonstrate key technical building blocks required for high throughput, high resolution e-beam step, and scan projection lithography. The supreme challenge facing all e-beam lithography approaches has been and still is throughput. Since the throughput of e-beam projection systems is severely limited by the available optical field size, the key to success is the ability to overcome this limitation. The PREVAIL technique overcomes field-limiting off-axis aberrations through the use of variable axis lenses, which electronically shift the optical axis simultaneously with the deflected beam, so that the beam effectively remains on axis. This technique developed by IBM has been successfully applied to probe-forming shaped beam systems (EL-4). It had to be modified and extended to provide the larger beam deflections and the wider beam images at the wafer plane used in projection reduction systems. The POC system projects sequentially 1×1 mm2 subfields, selected at the reticle, in 4:1 reduction mode onto the wafer, exposing and resolving patterns of 80 nm lines and spaces in resist; each subfield contains 107 pixels. The deflection capability demonstrated permits electronic selection of 20 1 mm subfields at the reticle and projection of these 20 subfields onto the wafer exposing a field with 5 mm scan length. The resist images provide proof that PREVAIL effectively eliminates off-axis aberrations affecting resolution, since the deflected and undeflected images are indistinguishable. PREVAIL also controls off-axis aberrations affecting placement accuracy of pixels, since distortions of the deflected subfield are corrected to within 12 nm. A high emittance gun has been developed to provide uniform illumination of the patterned subfield, and to fill the large numerical aperture of the projection optics required to significantly reduce beam blur caused by Coulomb interaction.
Spectral reflectance technique for retinal blood oxygen evaluation in humans (2003)

Retinal diseases such as diabetic retinopathy, glaucoma, vein occlusion and optic nerve atrophy are associated with abnormal oxygen tension and bloodflow in surface vessels of the retina. Visible reflected light spectroscopy has in the past been applied to hemoglobin oxygen saturation measurements from the body surface, as with measurements from skin and wounds, from intact brain vessels during surgical intervention, and as well, from the retinal vessels and other ocular structures inside the body. All of these measurements are complicated by lack of visible light penetration, interference from secondary chromophores, specular return of light and wavelength-dependent penetration to different layers in different structures. We present spectral reflectance curves obtained with a prism-grating-prism (PGP) spectrographic camera from structures producing hemoglobin signatures, including the retinal artery and vein, the pigmented retina and the optic disk, as well as from the macular area which is free of this signature. Oxygen-dependent changes in the hemoglobin signature are determined from vessels and tissue surround.
Elimination of Mutual Flux Effect on Rotor Position Estimation of Switched Reluctance Motor Drives (2014)

An approach to eliminate mutual flux effect on rotor position estimation of switched reluctance motor drives at rotating shaft conditions without a prior knowledge of mutual flux is proposed in this paper. Neglecting the magnetic saturation, the operation of conventional self-inductance estimation using phase current slope difference method can be classified into three modes: Mode I, II, and III. At positive-current-slope and negative-current-slope sampling point of one phase, the sign of current slope of the other phase changes in Mode I and II, but does not change in Mode III. Theoretically, based on characteristics of a 2.3 kW, 6000 rpm, three-phase 12/8 SRM, mutual flux introduces a maximum ±7% self-inductance estimation error in Mode I and II, while, in Mode III, mutual flux effect does not exist. Therefore, in order to ensure that self-inductance estimation is working in Mode III exclusively, two methods are proposed: variable-hysteresis-band current control for the incoming phase and variable-sampling self-inductance estimation for the outgoing phase. Compared with the conventional method which neglects mutual flux effect, the proposed position estimation method demonstrates an improvement in position estimation accuracy by 2°. The simulations and experiments with the studied motor validate the effectiveness of the proposed method.
Vehicular Networks for Collision Avoidance at Intersections (2011)

<div class="section abstract"><div class="htmlview paragraph">A substantial fraction of automotive collisions occur at intersections. Statistics collected by the Federal Highway Administration (FHWA) show that more than 2.8 million intersection-related crashes occur in the United States each year, with such crashes constituting more than 44 percent of all reported crashes [<span class="xref">12</span>]. In addition, there is a desire to increase throughput at intersections by reducing the delay introduced by stop signs and traffic signals. In the future, when dealing with autonomous vehicles, some form of co-operative driving is also necessary at intersections to address safety and throughput concerns.</div><div class="htmlview paragraph">In this paper, we investigate the use of vehicle-to-vehicle (V2V) communications to enable the navigation of traffic intersections, to mitigate collision risks, and to increase intersection throughput significantly. Specifically, we design a vehicular network protocol that integrates with mobile wireless radio communication standards such as Dedicated Short Range Communications (DSRC) and Wireless Access in a Vehicular Environment (WAVE). This protocol relies primarily on using V2V communications, GPS and other automotive sensors to safely navigate intersections and also to enable autonomous vehicle control. Vehicles use DSRC/WAVE wireless media to periodically broadcast their position information along with the driving intentions as they approach intersections. We used the hybrid simulator called GrooveNet [<span class="xref">1</span>, <span class="xref">2</span>] in order to study different driving scenarios at intersections using simulated vehicles interacting with each other. Our simulation results indicate that very reasonable improvements in safe throughput are possible across many practical traffic scenarios.</div></div>
Preparing high-efficiency perovskite solar cells (2014)

Organometal trihalide perovskites are emerging as a new generation of photovoltaic materials. They are abundant in nature and have rapidly increasing power conversion efficiencies (PCE) of above 15% in common hybrid (mixed organic/inorganic) thin-film-based solar cells.1–3 Up to now, perovskite films have been formed by film deposition approaches such as spin-coating, sequential deposition of the inorganic and organic precursor, and co-evaporation of the precursors.1, 2 Low-temperature solution processes are among the simplest ways to fabricate planar low-cost photovoltaic devices. However, perovskite crystallizes very rapidly, so it is very challenging to form uniform, continuous, and leakage-free perovskite films by solution methods.2 We developed two simple and effective low-temperature solution processes to fabricate high-efficiency perovskite devices (see Figure 1). In the first approach, we studied the influence of the ratio of the precursors methylammonium iodide (CH3NH3I) and lead iodide (PbI2) in a premixed solution. 3 We found that using a non-stoichiometric precursor solution (i.e., not in a simple ratio) was critical to forming stoichiometric (i.e., in a simple ratio) perovskite films. The compositions of the spun perovskite films were very sensitive to the substrate surface, and could be very different from those of the precursor solutions. We varied the composition of the precursor solution, and found a PbI2/CH3NH3Xmolar ratio of 0.6–0.7 gave the best surfacemorphology and electronic properties, such as doping concentration. We used a planar heterojunction device structure of ITO/ PEDOT:PSS/(CH3NH3I)/PCBMor ICBA/C60/BCP/aluminum, where ITO is a substrate of indium tin oxide, PEDOT:PSS is an electron-donating transparent conductive polymer, PCBM and ICBA are fullerene-derived electron acceptors, C60 is buckminsterfullerene (a spherical fullerene molecule), and BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, an electrontransporting but hole-blocking layer. Figure 1. Schematic of the prepation of perovskite films by (a) spin coating of pre-mixed precursor of lead iodide (PbI2) and methylammonium iodide (CH3NH3I) and (b) an interdiffusion approach. ITO: Indium tin oxide, a transparent conducting oxide. PEDOT:PSS: A transparent, conductive polymer. MAI: Methylammonium iodide. MAPbI3 Methylammonium lead iodide.
Production of novel manufactured plastic aggregate and its utilisation in concrete (2017)

Plastic waste and its low recycling rate make a significant contribution towards the pollution of the environment. Therefore , it is essential that plastic waste is utilised in different applications . One of the applications is its use either as an aggregate or to form aggregate for use in the concrete. New aggregates were developed using plastic waste and by-product or low cost granular materials. These aggregates have a relatively low density and water absorption as compared to conventional aggregates , and were successfully used to produce sustainable or green lightweight concrete. The new aggregates were used to replace the conventional coarse fraction of either nonnal weight or lightweight aggregates at full or partial replacements; where both properties of fresh and hardened concrete were investigated. It was found that the effect of the replacement level of the conventional aggregate with the manufactured recycled plastic aggregates was less prominent on density as compared to the other properties. The hardened concrete showed a reduction in mechanical properties , with an increase in the proportions of manufactured recycled plastic aggregates in the mix . The assessment of durability properties, thermal conductivity and curing temperature was also carried out. The concrete ductility, drying shrinkage, creep strain and thennal conductivity increased as the content of manufactured recycled plastic aggregate increased in the mix. Whilst, the chloride penneability was found to decrease with an increase in the percentage of recycled plastic aggregate. Finally, models were proposed to predict the mechanical and durability properties utilising the results of this study.
Tunable coupling cavity QED with a superconducting artificial atom (2012)

We present a tunable coupling qubit (TCQ), which has independent and fast control over the qubit energy and the coupling strength to a superconducting microwave cavity in a circuit quantum electrodynamics architecture.
Hepatic gene expression in patients with obesity‐related non‐alcoholic steatohepatitis (2005)

Several differentially expressed genes in patients with NASH are related to lipid metabolism and extracellular matrix remodeling. Additionally, genes related to liver regeneration, apoptosis, and the detoxification process were differentially expressed. These findings may help clarify the molecular pathogenesis of NASH and identify potential targets for therapeutic intervention.
Controlling the age of information: Buffer size, deadline, and packet replacement (2016)

We study the age of information, which is a recently introduced metric for measuring the freshness of a continually updated piece of information as observed at a remote monitor. The age of information metric has been studied for a variety of different queuing systems, and in this work, we consider the impact of buffer sizes, packet deadlines, and packet replacement on the average age of information for queuing systems. We conduct a simulation-based study in which we modeled a wide variety of queuing systems and control mechanisms in simulation and computed the average age of information. We first study the buffer size alone to see how it affects the average age, and then we look at adding a packet deadline for such a system. We consider packet deadline control in the buffer only and in both the buffer and server, and we also compare the performance with a random deadline. We observe how the buffer size and deadline are optimized for the age, and we identify general trends for how to choose values of control mechanisms under different conditions of the packet generation rate. Lastly, we study the ability to replace packets in the buffer with newly arriving packets, and we are particularly interested in whether we can achieve the performance of such a system by controlling buffer size and deadline alone, for systems in which we do not have the ability to do packet replacement.
Demonstration of damage-free mask repair using electron beam-induced processes (2004)

In this paper, we present the test results obtained from the first commercial electron beam mask repair tool. Repaired defect sites on chrome-on-glass masks are characterized with 193nm AIMS to quantify the edge placement precision as well as optical transmission loss. The electron beam mask repair tool is essentially based on a scanning electron microscope (SEM), therefore, it can be used for <i>in-situ</i> CD and defect metrology. E-beam for EUV mask defect repair is also discussed. These early results are very encouraging and demonstrate the basic advantages of electron beam mask repair as well as highlight the key challenge of charge control.
Contrasting Effects of Various Potassium Salts on Renal Citrate Excretion* (1991)

Mechanisms for the citraturic response to potassium citrate treatment were sought by assessing renal citrate clearance and acid-base status after oral administration of potassium citrate, potassium bicarbonate, and potassium chloride. After 2 weeks of treatment of eight patients with stones at a dose of 80 meq/day, urinary citrate rose significantly from 2.5 +/- 1.6 mmol/day (no drug) to 5.1 +/- 1.7 mmol/day with potassium citrate and to 4.5 +/- 1.5 mmol/day with potassium bicarbonate (P less than 0.05), but did not change significantly with potassium chloride. Citrate clearance increased from 8.0 to 27.4 mL/min with potassium citrate and 25.8 mL/min with potassium bicarbonate (P less than 0.05), but did not increase with potassium chloride. Both potassium citrate and potassium bicarbonate significantly raised urinary bicarbonate and decreased urinary ammonium, titratable acid, and net acid excretion. Potassium chloride was without effect. Effects of potassium citrate on urinary citrate, citrate clearance, and acid-base status tended to be more prominent than those of potassium bicarbonate, but these changes were not significant. Thus, the citraturic action of potassium citrate is largely accountable for by provision of an alkali load. Potassium itself had no effect in the absence of potassium deficiency.
Development of DFB Quantum Cascade Lasers and their Applications (2008)

We have developed single-mode quantum cascade lasers (QCLs) emitting at 5.2μm and 7.7 Em. Single-mode emission with narrow line width is achieved using a distributed feedback (DFB) technology. A narrow line width is interpreted in terms of an extremely small effective coupling efficiency of spontaneous emission, caused by ultrafast nonradiative scatterings. We have demonstrated absorption signal detection of NO, N2O, and CH4. The highest spectral resolution can be achieved with a CW mode DFB-QCL. We have observed lines of isotopomer of nitrous oxide, and signal detection limit is about 50 ppb.
Synthesis and Evaluation of Nonpeptide Substituted Spirobenzazepines as Potent Vasopressin Antagonists. (2004)

Abstract For Abstract see ChemInform Abstract in Full Text.
Revealing the Substructure of Single-Walled Carbon Nanotube Fibers (2005)

Single-walled carbon nanotubes (SWNTs) uniquely combine characteristics of polymers (e.g., they are molecules composed of repeat units) as well as nanoscale colloids (e.g., they are extremely stiff); because of these characteristics, they may qualify as the ideal building blocks for the long-sought Staudinger's “continuous crystal.” To this end, neat SWNT fibers have been produced by wet-spinning concentrated dispersions of 6−10 wt % SWNTs in 102% H2SO4. A unique protocol that combined UV−ozone dry chemical etching and cryoultramicrotoming was developed to directly visualize the internal voids, alignment, and composition of these SWNT neat fibers. A substructure of large aligned SWNT ropes, 200−500 nm in diameter, was revealed throughout the fibers. This substructure may be linked to the SWNT spaghetti, threadlike liquid-crystalline domains observed in dispersions of SWNTs in H2SO4.
Smart meter aggregation via secret-sharing (2013)

We design and prototype protocols for processing smart-meter readings while preserving user privacy. We provide support for computing non-linear functions on encrypted readings, implemented by adapting to our setting efficient secret-sharing-based secure multi-party computation techniques. Meter readings are jointly processed by a (public) storage service and a few independent authorities, each owning an additive share of the readings. For non-linear processing, these parties consume pre-shared materials, produced by an off-line trusted third party. This party never processes private readings; it may be implemented using trusted hardware or somewhat homomorphic encryption. The protocol involves minimal, off-line support from the meters---a few keyed hash computations and no communication overhead.
Interface Formation in Monolayer Graphene-Boron Nitride Heterostructures (2012)

The ability to control the formation of interfaces between different materials has become one of the foundations of modern materials science. With the advent of two-dimensional (2D) crystals, low-dimensional equivalents of conventional interfaces can be envisioned: line boundaries separating different materials integrated in a single 2D sheet. Graphene and hexagonal boron nitride offer an attractive system from which to build such 2D heterostructures. They are isostructural, nearly lattice-matched, and isoelectronic, yet their different band structures promise interesting functional properties arising from their integration. Here, we use a combination of in situ microscopy techniques to study the growth and interface formation of monolayer graphene-boron nitride heterostructures on ruthenium. In a sequential chemical vapor deposition process, boron nitride grows preferentially at the edges of existing monolayer graphene domains, which can be exploited for synthesizing continuous 2D membranes of graphene embedded in boron nitride. High-temperature growth leads to intermixing near the interface, similar to interfacial alloying in conventional heterostructures. Using real-time microscopy, we identify processes that eliminate this intermixing and thus pave the way to graphene-boron nitride heterostructures with atomically sharp interfaces.
A Silicon-Strip Detector for Photon-Counting Spectral CT: Energy Resolution From 40 keV to 120 keV (2014)

We are developing a segmented silicon-strip detector for spectral computed tomography. The detector operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we determine the energy resolution of a detector module using monoenergetic x-rays from 40 keV to 120 keV, provided at the European Synchrotron Radiation Facility, Grenoble. For each incident x-ray energy, pulse height spectra at different input photon fluxes are obtained. We investigate changes of the energy resolution due to charge sharing between pixels and pulse pileup. The different incident energies are used to channel-wise calibrate the pulse-height response in terms of signal gain and offset and to probe the homogeneity of the detector module. The detector shows a linear pulse-height response in the energy range from 40 keV to 120 keV. The gain variation among the channels is below 4%, whereas the variation of the offsets is on the order of 1 keV. We find an absolute energy resolution ( σE) that degrades from 1.5 keV to 1.9 keV with increasing x-ray energy from 40 keV to 100 keV. With increasing input count rate, σE degrades by approximately 4 ·10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> keV Mcps <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , which is, within error bars, the same for the different energies. The effect of charge sharing on the width of the response peak is found to be negligible.
Discovery of a Novel, Potent Spirocyclic Series of γ-Secretase Inhibitors (2015)

In the present paper, we described the design, synthesis, SAR, and biological profile of a novel spirocyclic sulfone series of γ-secretase inhibitors (GSIs) related to MRK-560. We utilized an additional spirocyclic ring system to stabilize the active chair conformation of the parent γ-secretase inhibitors. The resulting series is devoid of the CYP2C9 inhibition liability of MRK-560. A few representative analogs were assessed in a nontransgenic animal model of Alzheimer's disease (AD), demonstrating reduction of amyloid-β (Aβ) in the CNS after acute oral dosing. A spirocyclic phosphonate was identified as the optimal ring system for both potency and pharmacokinetics. Compared to GSIs studied in the clinic, representative spirocyclic phosphonate 18a(-) features improved selectivity for the inhibition of the PS-1 isoform of γ-secretase (33-fold vs PS-2), which may alleviate the adverse effect profile of the clinical GSIs.