gebhart/patrepeval huggingface dataset:
Laguerre filters with adaptive pole optimization (2002)

An algorithm for an adaptive Laguerre filter is described. The Laguerre weights are updated using standard RLS. As a new feature the Laguerre pole is adapted at each sampling instant for more flexibility. The additional complexity that is required to calculate the gradient w.r.t. the pole is small. A sign algorithm is used in order to have complete control of the step size with which the Laguerre pole is varied. The step size in the sign algorithm is pole dependent and chosen such that the cumulative transient signal caused by the persistent tuning of the Laguerre pole remains small enough. Also, the step size is chosen such that the Laguerre filter always remains stable. A computer experiment shows that the adaptive filter performs well.
<i>Colloquium</i>: Majorana fermions in nuclear, particle, and solid-state physics (2015)

Ettore Majorana (1906--1938) disappeared while traveling by ship from Palermo to Naples in 1938. His fate has never been fully resolved and several articles have been written that explore the mystery itself. His demise intrigues us still today because of his seminal work, published the previous year, that established symmetric solutions to the Dirac equation that describe a fermionic particle that is its own antiparticle. This work has long had a significant impact in neutrino physics, where this fundamental question regarding the particle remains unanswered. But the formalism he developed has found many uses as there are now a number of candidate spin-$1/2$ neutral particles that may be truly neutral with no quantum number to distinguish them from their antiparticles. If such particles exist, they will influence many areas of nuclear and particle physics. Most notably the process of neutrinoless double beta decay can exist only if neutrinos are massive Majorana particles. Hence, many efforts to search for this process are underway. Majorana's influence does not stop with particle physics, however, even though that was his original consideration. The equations he derived also arise in solid-state physics where they describe electronic states in materials with superconducting order. Of special interest here is the class of solutions of the Majorana equation in one and two spatial dimensions at exactly zero energy. These Majorana zero modes are endowed with some remarkable physical properties that may lead to advances in quantum computing and, in fact, there is evidence that they have been experimentally observed. This Colloquium first summarizes the basics of Majorana's theory and its implications. It then provides an overview of the rich experimental programs trying to find a fermion that is its own antiparticle in nuclear, particle, and solid-state physics.
Computer-aided design of a proton pump (1997)

The use of transmembrane proton gradients in energy transduction is an almost universal feature of life on earth. These proton gradients are established and maintained by specialized assemblies of proteins which actively pump protons across membranes. One broad class of proton pumps uses captured light energy to drive the proton pumping. Our goal is to elucidate the minimum structural requirements of a light-driven proton-pump. There are two basic components to a simple light-driven proton pump: a source of photo-generated protons and a which prevents these protons from reattaching themselves to their source. A wide variety of molecules in the membrane, even as simple as polycyclic aromatic hydrocarbons, are capable of releasing protons when illuminated. Our work is therefore focused on the design of the Our initial model involves a pair of proton acceptors, coupled to each other by a transient water bridge, and supported in the membrane by a small bundle of peptide helices. Upon illumination, the proton source transfers its proton to the:- first acceptor of the gate-keeper. While the reverse reaction is highly probable, all that is needed to ensure irreversibility is a nonvanishing probability that the proton will be transferred to the second acceptor across a transient water bridge. Back transfer of the proton to the first acceptor, and thence to the proton source, is impeded by the free energy required to move the proton uphill towards the. proton source and by the disruption of the transient water bridge. As a prototypical water-bridged proton transfer system, we are studying the transfer of a proton across a water bridge from a formic acid to a formate anion. With a pK(sub alpha), of 3.7. formic acid is a good model for the acidic amino acids glutamate and aspartate which are good candidates for gate-keeper proton acceptors. Simulations of proton transfer reactions in a membrane are complicated by the quantum mechanical nature of the process breaking and forming chemical bonds.
The Discovery of a Selective, Small Molecule Agonist for the Mas-Related Gene X1 Receptor (2009)

The novel 7-transmembrane receptor MrgX1 is located predominantly in the dorsal root ganglion and has consequently been implicated in the perception of pain. Here we describe the discovery and optimization of a small molecule agonist and initial docking studies of this ligand into the receptor in order to provide a suitable lead and tool compound for the elucidation of the physiological function of the receptor.
Design, fabrication and testing of a Dyneema/polyethylene radome for airborne remote sensing (1998)

Most radomes consist of a solid laminate or sandwich type structure made of fiberglass reinforced plastics. The use of Dyneema (trademark of DSM) fibers in a polyethylene (PE) matrix instead of fiberglass reinforced plastics for radomes is very interesting because of the excellent radar transparancy of Dyneema/PE. However, because of its sensitivity for creep, applications in aerodynamically loaded structures are limited. The key problems facing their use in radomes are how to improve the mechanical properties to an acceptable level and how to mount the radome on the radar pod. This paper presents the development of a Dyneema/PE radome for airborne remote sensing. Several electrical properties and design aspects of the radome are discussed. The effect of the consolidation conditions on the creep behaviour and the configuration of the mounting system are described. Test flight results are evaluated.
1.6.2 Generic Approach for Systems Design Optimization in MBSE1 (2012)

Abstract The complexity of contemporary systems causes Systems Engineers great pains during early architectural design phases. Model‐Based Systems Engineering (MBSE) proposes methodologies to deal with complexity and streamline design processes, but the penetration of the new approach is slow. This paper proposes a generic SysML based methodology for improving the Architectural Design phase of Systems and mitigate the barriers for MBSE adoption. The proposed methodology suggests an alternative way to formalize requirements, define design alternatives, automate design space exploration and examine optimization results in the original modeling format. A representative example is provided. A glossary is included at the end of the paper.
<i>Plasmas and Controlled Fusion</i> (1962)

Share Icon Share Twitter Facebook Reddit LinkedIn Reprints and Permissions Cite Icon Cite Search Site Citation David J. Rose, Melville Clark, Howard Chang; Plasmas and Controlled Fusion. Physics Today 1 June 1962; 15 (6): 58. https://doi.org/10.1063/1.3058226 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentPhysics Today Search Advanced Search
Coordination Chemistry of<i>N</i>-Alkylbenzamide-2,3-dithiolates as an Approach to Poly(dithiolate) Ligands:  1,4-Bis[(2,3-dimercaptobenzamido)methyl]benzene and Its Chelate Complex with the (C<sub>5</sub>H<sub>5</sub>)Ti Fragment (1998)

The bidentate dithiolate ligands N,N-diethyl-2,3-dimercaptobenzamide (H(2)-1), bis(N,N-diethyl-2,3-dimercaptoterephthalamide (H(2)-2), and 1,4-bis(hydroxymethyl)-2,3-dimercaptobenzene (H(4)-3) were synthesized from 2,3-dimercaptobenzoic acid or 2,3-dimercaptoterephthalic acid. The air-sensitive ligands form metallocene complexes of the type [(eta(5)-C(5)H(5))(2)Ti(1)] (13), [(eta(5)-C(5)H(5))(2)Mo(1)] (15), [(eta(5)-C(5)H(5))(2)Ti(3)] (16), and [(eta(5)-C(5)H(5))(2)Ti(2)] (17). Complexes 15 and 16 were characterized by X-ray diffraction. Selected crystallographic details for 15 are as follows: formula C(21)H(23)MoNOS(2); M = 465.49; Pbca; a = 12.536(3), b = 14.313(3), c = 22.463(3) Å; V = 4031(2) Å(3); Z = 8; R = 3.56 and R(w) = 4.49 for 2111 structure factors (F(o)(2) >/= 3sigma(F(o)(2))) and 254 refined parameters. The molybdenum complex 15 shows an almost planar Mo(&mgr;-S)(2)C(2) chelate ring. Selected crystallographic details for 16 are as follows: formula C(18)H(18)O(2)S(2)Ti; M = 378.35; P&onemacr;; a = 10.1778(11), b = 11.5806(14), c = 22.967(3) Å; alpha = 96.42(1), beta = 101.74(1), gamma = 108.82(1) degrees; V = 2462.3(5) Å(3); Z = 6; R = 4.79 and R(w) = 13.27 for 5426 structure factors (I >/= 2sigma(I)) and 766 refined parameters. All titanocene derivatives assume the envelope conformation. The free activation energy for the flip around the S-S axis was determined for 13 to be 69 kJ/mol. The bis(dithiolate) ligand 1,4-bis[(2,3-dimercaptobenzamido)methyl]benzene (H(4)-4) was prepared from 2,3-dimercaptobenzoic acid and converted into the dinuclear air-stable titanocene complex [{(eta(5)-C(5)H(5))(2)Ti}(2)(4)] (19). Complex 19 reacts with HCl/CHCl(3) with liberation of free H(4)-4 while reaction with NMe(4)Cl results in an intramolecular dithiolate shift under formal liberation of [(C(5)H(5))(3)TiCl] and formation of the square-pyramidal chelate complex (NMe(4))[(eta(5)-C(5)H(5))Ti(4)], (NMe(4))[20]. Crystallographic details for (NMe(4))[20].CH(2)Cl(2) are as follows: formula C(32)H(35)Cl(2)N(3)O(2)S(4)Ti; M = 740.67; P&onemacr;; a = 11.579(4), b = 12.210(4), c = 14.016(4) Å; alpha = 112.28(2), beta = 94.46(3), gamma = 104.22(3) degrees; V = 1744.9(10) Å(3); Z = 2; R = 5.35 and R(w) = 12.84 for 2870 structure factors (I >/= 2sigma(I)) and 397 refined parameters. The chelate rings in [20](-) assume an endo/exo conformation.
Average-power mediated ultrafast laser osteotomy using a mode-locked Nd:YVO[sub 4] laser oscillator (2007)

By using a novel temporal characterization technique, we determined that a threshold average laser power of 160 mW is required to drill through a 0.75-mm-thick cortical bone for a Nd:YVO(4) mode-locked laser oscillator with a peak intensity of 1.3 GWcm(2). The ablation mechanism is identified as average-power induced carbonization followed by peak-power induced avalanche ionization in the carbonized osseous tissue.
SURFACE TENSION, STICKINESS AND ENGULFMENT (1998)

ABSTRACT The thermodynamic conditions for the engulfment of one set of particles by another has been given in terms of interfacial energies. Experimentally, it has been shown that a polymer with a high glass transition temperature can be engulfed by a particle of low glass transition temperature; also, that Inorganic particles can be engulfed by polymer particles. As a precursor to the engulfment stage heterocoagulation can be used for bringing the particles together in a ‘sticking’ mode. This appears to be a general process which is applicable to a number of scientific areas, e.g. in biology, phagocytosis, and in material science for the preparation of composite particles.
<i>Colloquium</i>: Nonequilibrium dynamics of closed interacting quantum systems (2011)

This Colloquium gives an overview of recent theoretical and experimental progress in the area of nonequilibrium dynamics of isolated quantum systems. There is particularly a focus on quantum quenches: the temporal evolution following a sudden or slow change of the coupling constants of the system Hamiltonian. Several aspects of the slow dynamics in driven systems are discussed and the universality of such dynamics in gapless systems with specific focus on dynamics near continuous quantum phase transitions is emphasized. Recent progress on understanding thermalization in closed systems through the eigenstate thermalization hypothesis is also reviewed and relaxation in integrable systems is discussed. Finally key experiments probing quantum dynamics in cold atom systems are overviewed and put into the context of our current theoretical understanding.
Pupil-phase optimization for extended-focus, aberration-corrected imaging systems (2004)

The insertion of a suitably designed phase plate in the pupil of an imaging system makes it possible to encode the depth dimension of an extended three-dimensional scene by means of an approximately shift-invariant PSF. The so-encoded image can then be deblurred digitally by standard image recovery algorithms to recoup the depth dependent detail of the original scene. A similar strategy can be adopted to compensate for certain monochromatic aberrations of the system. Here we consider two approaches to optimizing the design of the phase plate that are somewhat complementary - one based on Fisher information that attempts to reduce the sensitivity of the phase encoded image to misfocus and the other based on a minimax formulation of the sum of singular values of the system blurring matrix that attempts to maximize the resolution in the final image. Comparisons of these two optimization approaches are discussed. Our preliminary demonstration of the use of such pupil-phase engineering to successfully control system aberrations, particularly spherical aberration, is also presented.
STAR TOPOLOGICAL SECURE SUM PROTOCOL WITH TRUSTED THIRD PARTY (2013)

Secure Multiparty Computation allows all parties to compute the common result of their individual data without disclosing their data to others party. Secure sum computation is one of the important tools of the Secure Multiparty Computation. In Secure Multiparty Computation lot of reputed researchers give their protocols, researchers show their interest. In this paper we proposed a new secure multi party computation protocol which is combination of both real and ideal model as well as the star topology for providing the highest privacy to the database with the zero percentage of data leakage and also the complexity of this protocol is very lesser as compare to other protocol and this protocol is useful for multi party computation. The complexity of this protocol is AE (n).
Dual optical control and mechanistic insights into photoswitchable group II and III metabotropic glutamate receptors (2017)

G protein-coupled receptor (GPCR) signaling occurs in complex spatiotemporal patterns that are difficult to probe using standard pharmacological and genetic approaches. A powerful approach for dissecting GPCRs is to use light-controlled pharmacological agents that are tethered covalently and specifically to genetically engineered receptors. However, deficits in our understanding of the mechanism of such photoswitches have limited application of this approach and its extension to other GPCRs. In this study, we have harnessed the power of bioorthogonal tethering to SNAP and CLIP protein tags to create a family of light-gated metabotropic glutamate receptors (mGluRs). We define the mechanistic determinants of photoswitch efficacy, including labeling efficiency, dependence on photoswitch structure, length dependence of the linker between the protein tag and the glutamate ligand, effective local concentration of the glutamate moiety, and affinity of the receptor for the ligand. We improve the scheme for photoswitch synthesis as well as photoswitch efficiency, and generate seven light-gated group II/III mGluRs, including variants of mGluR2, 3, 6, 7, and 8. Members of this family of light-controlled receptors can be used singly or in specifically labeled, independently light-controlled pairs for multiplexed control of receptor populations.
Differential packing as a possible display of bedding (1939)

ABSTRACT The possibility that bedding and cross-lamination can be displayed by only an alternation of packing patterns was demonstrated in the laboratory by an artificially deposited clastic rock. A model of a coarse sandstone built up of uniform wooden balls, thereby eliminating entirely differences in size, shape, and composition of the constituent particles and restricting the differentiating variable to packing, showed bedding. Although this arrangement has not been located in natural rocks, it may be found after appropriate search. Hope for its existence is strengthened by the fact that open and close packing within sands is well known.
Engineered cationic antimicrobial peptide (eCAP) prevents<i>Pseudomonas aeruginosa</i>biofilm growth on airway epithelial cells (2016)

While other studies have demonstrated the ability of natural and synthetic antimicrobial peptides to prevent abiotic bacterial biofilm formation, the current studies for the first time demonstrate the effective peptide treatment of a biotic bacterial biofilm in a setting similar to the CF airway, and without negative effects on human airway epithelial cells, thus highlighting the unique potential of this engineered cationic antimicrobial peptide for treatment of human respiratory infections.
Resistance to acetolactate synthase inhibitors and quinclorac in a biotype of false cleavers (<i>Galium spurium</i>) (1998)

A false cleavers population that survived treatment with triasulfuron/bromoxynil in 1996 was identified in central Alberta, Canada, in a field that had been treated with acetolactate synthase (ALS) inhibitors in 3 of the previous 6 yr. In greenhouse studies, this biotype was highly resistant to the ALS inhibitors triasulfuron, thifensulfuron/tribenuron, and sulfometuron and moderately resistant to imazethapyr; GR 50 , values were > 16, > 5, > 1.0, and 9.9, respectively. In addition, cross-resistance was identified to the auxin-type herbicide quinclorac (GR 50 value > 6.7) but not to fluroxypyr (GR 50 value 1) or MCPA/mecoprop/dicamba. Quinclorac had not been used previously in this field. Analysis of ALS extracted from the resistant biotype and a susceptible biotype from a nearby location indicated that resistance to ALS inhibitors was due to an altered target site with reduced sensitivity to a broad range of ALS inhibitors. The ALS I 50 values for triasulfuron, metsulfuron, chlorsulfuron, thifensulfuron, and imazethapyr were 36, 34, 92, 96, and 14 times higher, respectively, for the resistant compared to the susceptible biotype. The mechanism of resistance to quinclorac is unknown. This is the first report of high-level herbicide resistance in this weed species.
Respiratory function impairment and cardiopulmonary consequences in long-time residents of the Canadian Arctic. (1980)

Spirometry, roentgenography and electrocardiography were performed during community health surveys in 1976-78 in 176 Inuit and other long-time residents of the northeastern (Arctic Bay) and western (Inuvik) Canadian Arctic, and the results were related to age, ethnic origin, occupation and history of climatic exposure, smoking and hospitalization for tuberculosis. In Arctic Bay the young men showed excellent respiratory function, normal-sized pulmonary arteries and normal electrocardiograms, but abnormalities of all three types were increasingly frequent and severe after age 25. The forced mid-expiratory flow (FMF) fell to less than 50% of the norm by age 40, and dilatation of the pulmonary artery, hypertrophy of the right ventricle, right bundle branch block and a pseudoinfarction pattern on the ECG were frequently associated. In contrast, the men in Inuvik, an urbanized centre, maintained above normal respiratory function until age 40, and the FMF and pulmonary artery diameter remained normal in the older men except for Inuit and white trappers over 60 years old who had run fox trap lines along the Arctic coast in the 1920s and 30s. These data suggest that inhalation of extremely cold air at maximum ventilation may be a prime factor in the chronic obstructive lung disease of Inuit hunters, whereas smoking has only a minor role and hospitalization for tuberculosis appears to protect from rather than contribute to this disorder.
Characterization of alkyl grafted polyurethane block copolymers by variable takeoff angle X‐ray photoelectron spectroscopy (1990)

Abstract Variable takeoff angle x‐ray photoelectron spectroscopy was used to determine the surface composition of five polyurethane block copolymers. The high‐resolution C 1 s spectra from all five polyurethane samples had peaks at binding energies of 285.0, 286.5, and 289.5 eV, which are consistent with the presence of hydrocarbon, ether, and urethane carbon species. Both the measured elemental compositions at the low takeoff angles (deepest sampling depths) and the calculated elemental compositions for depths > 15 Å generally showed good agreement with the expected bulk compositions. The outer 15 Å of the surface of all five samples was depleted in the nitrogen‐containing hard segment. For the base polyurethane sample in this series, an enrichment of the poly(tetramethylene oxide) soft segment and the presence of an organic silicone impurity were detected. Doubling the chain length of both the hard and soft segments resulted in a further decrease of the hard segment concentration in the outer surface of the sample. The grafting of C2 and C18 alkyl groups onto 10 or 20% of the ure‐thane linkages resulted in an increase in the percentage of aliphatic carbon species present on the surface. In the case of the C18‐alkylated material, the presence of alkyl chains at the surface was inferred using contact angle measurements.
Dual‐film cassette technique for studying the effect of radiographic image quality on diagnostic accuracy (1984)

In order to investigate the relationship between diagnostic accuracy and radiographic image quality, we have developed a dual-film cassette which produces two radiographs simultaneously with a single exposure. One of these radiographs is of standard quality; the second is of lower quality because of degraded spatial resolution and a significantly lower exposure. We have studied the basic physical properties of the standard and low-dose screen-film systems which we use in the dual-film cassette by comparing their beam hardening, scatter fractions, contrasts, modulation transfer functions (MTFs), and Wiener spectra. The x-ray spectrum incident on the low-dose system contained more high-energy photons than that incident on the standard system, and the scatter fractions for the low-dose system were slightly less than or comparable to those for the standard system. While the radiographic contrast produced by the two systems were generally comparable, the standard system had a slightly higher contrast than the low-dose system in some cases. The MTF of the low-dose system was considerably lower than that of the standard system, and the low-dose system had a noise level considerably greater than did the standard system. Phantom images and clinical radiographs indicated that, for the low-dose system, the image quality degraded significantly.