gebhart/patrepeval huggingface dataset:
Comparison of vibratory and rotating-wheel gyroscopic rate indicators (1960)

RECENT ADVANCES in atmospheric and space flight have increased the need for reliable and accurate instrumentation for sensing the angular motions of aircraft, missiles, and space ships. Such measurements are especially needed for guidance and control purposes. At the present time, the preferred devices for measuring angular motion are based on the rotating-wheel gyroscope. By the expenditure of much research and development effort these gyroscopic devices have been brought to a state of perfection which makes inertial navigation technically feasible but very expensive. The present reliance on the rotating wheel does not mean that other devices have not been considered. Over the years a number of alternatives to the rotating wheel have been devised and some of these have been developed to the point where practical limitations on performance were found. In general, however, the total research and development effort that has been devoted to these alternatives has been rather small compared with the effort that has been expended in the refinement of the rotating-wheel gyroscope.
Influence of Externally Imposed and Internally Generated Electrical Fields on Grain Growth, Diffusional Creep, Sintering and Related Phenomena in Ceramics (2011)

Microwaves and spark plasma sintering ( SPS ) enhance sinterability. Simple electrical fields, applied by means of a pair of electrodes to bare specimens, have been shown to accelerate the rate of superplastic deformation, reduce the time and temperature for sintering, and to retard the rate of grain growth. By inference, the influence of electrical and electromagnetic fields on grain boundary energetics and kinetics is unmistakable. Often, in ceramics, grain boundaries are themselves endowed with space charge that can couple with externally applied fields. The frequency dependence of this coupling ranging from zero frequency to microwave frequencies is discussed. The classical approach for modeling grain growth, creep, and sintering, considers chemical diffusion (self‐diffusion) under a thermodynamic driving force, underpinned by a physical mechanism that visualizes the flow of mass transport in a way that reproduces the phenomenological observations. In all instances, the final analytical result can be separated into a product of three functions: one of the grain size, the second related to the thermodynamic driving force, and the third to the kinetics of mass transport. The influence of an electrical field on each of these functions is addressed.The fundamental mechanisms of these electrical interactions are discussed in the following ways: (i) dielectric loss and Joule heating in the crystal and at the grain boundary, (ii) the coupling between mechanical stress and the electrochemical potential of charged species, (iii) the interaction between applied electrical fields and the intrinsic fields that exist within the space charge layers, (iv) and the possibility of nucleating defect avalanches under electrical fields. We limit ourselves to ceramics that have at least some degree of ionic character. In these experiments the electrical fields range from several volts to several hundred volts per centimeter, and the power dissipation from Joule heating is of the order of several watts per cubic centimeter of the specimen. Metals, where very high current densities are obtained at relatively low applied electric fields, leading to phenomenon such as electromigration, are not considered.
Dynamics of Fly-Contact Head Disk Interface (2008)

Fly-contact head disk interface (HDI) is known as a promising approach for the further reduction of the magnetic spacing between the head and media for ultra high recording density. In this paper, we report a numerical simulation study on the dynamics of the fly-contact head disk interface. It is found that design of a stable and reliable fly-contact HDI needs to consider the balance of minimizing both the fly-height (FH) variation and the contact force. The critical contact force - the minimal contact force for a stable fly-contact HDI is explored and a critical contact force of as low as 3.1 mN is obtained. It is found that the critical contact force depends on the combined effect of air bearing force, adhesive force and suspension load, which can be optimized by a proper air bearing surface and suspension design.
Two-Dimensional Nitroxide-Based Molecular Magnetic Materials (1998)

Manganese(II) complexes of imidazolyl-substituted chelating nitronylnitroxides are characterized by a stereoselective arrangement of the metal centers and the ligands to give a honeycomblike layer structure (shown on the right). The magnetic properties at high temperature indicate the presence of a ferrimagnetic structure within the layers. At low temperatures, ferromagnetic ordering is observed.
Rapid Detection of <i>vanA</i> and <i>vanB</i> Genes Directly from Clinical Specimens and Enrichment Broths by Real-Time Multiplex PCR Assay (2003)

A real-time PCR assay previously developed for use on the Roche LightCycler platform was investigated as an alternative to culture for the direct detection of vancomycin-resistant enterococci (VRE) in clinical specimens. PCR primers and fluorescence resonance energy transfer hybridization probes specific for the vanA and vanB genes were combined in a multiplex real-time PCR assay performed directly with fecal material obtained by rectal swabbing and with enrichment broth samples. DNA was prepared from the rectal swabs and enrichment broths with a commercially available DNA preparation column designed specifically for use with fecal specimens. One hundred eighty duplicate rectal swabs were obtained from 42 patients who were previously found to be positive for VRE and who were being monitored for carriage of VRE. Direct and enrichment broth cultures were performed with one swab, while PCR was performed with the other swab as well as any corresponding presumptive positive enrichment broth. In total, 100 specimens from 30 patients remained positive for VRE by at least one method. The multiplex real-time PCR was positive for 88 enrichment broths of rectal swabs from 27 patients but for only 45 rectal swabs from 15 patients. Direct culture was positive for VRE for only 43 specimens from 11 patients, while enrichment broth culture was positive for VRE for 75 specimens from 22 patients. Inhibition studies for the multiplex real-time PCR assay, performed by spiking the DNA extracts from 50 negative rectal swabs and the corresponding enrichment broths with between 1 and 10 CFU of a VanB Enterococcus faecium strain, detected inhibition rates of 55.1 and 10%, respectively. PCR performed directly with enrichment broths was found to be significantly more sensitive than enrichment broth culture (P < 0.025). Negative samples were identified significantly earlier by PCR than by culture alone.
Capillary phenomena on a liquid surface (1970)

Contraction of a liquid sheet of an incompressible Newtonian fluid in a passive ambient fluid is studied computationally to provide insights into the dynamics of capillary wave created during contraction. The problem composed of the Navier-Stokes system is associated with initial and boundary conditions that govern the time evolution of the capillary wave and the pressure and velocity fields within it. The correctness of the algorithm is verified with the data of experiment. It can be found that the prediction of the computation agrees well with the experiment. The algorithm is capable of capturing the capillary wave and therefore it is used to study the characteristic phenomena of that wave created on the surface of the liquid. Results show that the capillary wave is radiated from the tip of the liquid sheet caused by surface tension. The amplitude of the tip wave is much larger than any other waves and the asymptotic approach of the wave peaks can be observed during the propagation of waves. The tip wave contains the highest pressure and gradually the peak values of both high and low pressures decrease with the propagation of waves. Fluid velocity is motivated by both pressure due to surface tension and recirculation in peak and trough of the wave. During the contraction of the liquid sheet, the tip velocity is not uniform. Initially the length of the sheet increases a little and very soon the contraction occurs and continues. After long time, the gradient of tip velocity becomes very small. Keywords: Capillary wave, liquid sheet.DOI: 10.3329/jme.v38i0.900 Journal of Mechanical Engineering Vol.38 Dec. 2007 pp.45-51
Development of novel chemical sensor devices based on LB films from phthalocyaninato-polysiloxane polymers (1990)

The formation of LB films by substituted phthalocyaninato-polysiloxanes indicates a new principle in the design of LB-suitable molecules since this material lacks the amphiphilic nature which has been thought of as being the basic requirement for successful LB film production. These completely hydrophobic polymers allow for the controlled and highly reproducible deposition of ultrathin films, the structure of which is examined. The LB films show a macroscopic anisotropy which can be described as a frozen-in liquid crystalline phase of rod-like molecules. The high chemical and thermal stability as well as the interesting redox and optical properties give rise to various applications in the field of electronic and optical devices. The use of this type of polymeric LB film as membranes in field-effect transistors is a new approach in designing chemical sensors. A device is presented which is stable for months when in contact with aqueous electrolyte. By changing the pH of the electrolyte solution, a fast and nearly Nernstian response is observed without long-time drifts. Several methods for the introduction of further chemical sensitivities are discussed.
A decision-directed network for dual-polarization crosstalk cancellation (1979)

Frequency reuse in the specific form of dual-polarized microwave communication systems has grown in importance in recent years as a practical means of radio spectrum conservation. Ideally the capacity of a given frequency allocation can be doubled through dual-polarization. However, hardware imperfections and propagation effects, particularly rain depolarization, prevent the achievement of this doubling without severe system performance degradation. A decision-directed cross-polarization correction network is presented whose operation depends on only simple base-band signal processing. No pilot tones or frequency offsets are required. The loop can work with any two-dimensional signal set for digital data transmission. The loop has been experimentally verified and provides a means of doubling the data capacity with little performance degradation.
A wideband analog multi-resolution spectrum sensing (MRSS) technique for cognitive radio (CR) systems (2006)

Spectrum sensing technology is most vital to the implementation of a CR system using dynamic spectrum resource management. This paper suggested a CR system architecture with a wideband dual-stage spectrum sensing technique - a coarse and a fine spectrum sensing. Specifically, the coarse spectrum sensing technique adopted wavelet transforms in this architecture to provide a multi-resolution spectrum sensing (MRSS) feature. Analog implementation of the MRSS block offers wideband, low-power, and real-time operation. From the system simulation results, MRSS achieved 15-, 20-, and 30-dB detection margin for FM, VSB, and OFDM signals, having the corresponding signal power of -110, -120, and -120 dBm, respectively
The end-to-end performance of multimedia information services: data analysis and simulation (2003)

The end-to-end performance of a general multimedia information retrieval service, operating across a local area network (LAN) using the TCP/IP packet protocols, is evaluated for various message sizes representative of full-color and gray-scale images, and a typical text article. The hardware and software component of the source and user terminals and the total number of users requesting service at one time are taken into account. Several parameters of each component are precisely analyzed using measurements and a decomposition method; these are used in a queuing model for computer simulation. The simulation model is tuned and verified by comparing its results with measurements taken on a laboratory prototype. Then, by varying component parameters in the model and observing the effect on the overall performance, the effects of many critical parameters can be quantified. The model is also used to predict the performance of future systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
A 3‐D display method of fuzzy shapes obtained from medical images (1991)

Abstract A three‐dimensional (3‐D) display of medical images allows better perception of the continuity of structures and spatial relationships than a display of individual slices. These 3‐D display methods consist of a contour extraction, a shape reconstruction and a shading. However, the boundary judgment of soft tissues, like a tumor, is difficult even for expert doctors. Especially, 3‐D display depends largely on a result of the contour extraction. The 3‐D display method is required to display the presentation of the continuity of organ shapes. This paper presents the development of a display method to preserve the continuity of organ shapes. The display method consists of the extraction of fuzzy shapes and their shading. The extraction of fuzzy shapes is executed by operation of the fuzzy c‐means clustering algorithm on medical images and the use of a connectivity of an organ shape. The shading of fuzzy shapes uses a volume rendering, which is analyzed numerically and improved to realize a powerfully interactive 3‐D display. The effectiveness of the proposed 3‐D display method is shown using head MRI images.
Cartographic Data Structures (1975)

Efficient and flexible data structures are important to the development of computer mapping. Most current data banks are characterized by 1) structures which are convenient at the input stage rather than at the stages of use within computer programs, 2) separate and uncoordinated files for different types of geographic features, and 3) a lack of information about neighboring entities. The term "neighborhood function" may be used to indicate the relative location of a geographic entity and is a concept which is involved in all three of these characteristics. Ongoing research on data structures had led to work on the GEOGRAF system for encoding planar data and the GDS ("Geographic Data Structure") for encoding three-dimensional surfaces. Both involve data manipulation between the digitizing stage and the actual use of the data within computer mapping programs.
Role of mechanical deformation in the texturing of coated conductor composites (2003)

Ni and Ni-based alloys have received considerable attention as the substrates for HTS coated conductors. A critical step in the successful fabrication of coated conductor composites on metal substrates is to produce cube texture by mechanical deformation using the rolling assisted biaxial textured substrate (RABiTS) approach. In this paper, we investigated the effects of mechanical deformation and heat treatment on the growth of texture in nickel and nickel–tungsten alloys with the objective of understanding mechanisms of mechanical texturing in coated conductor substrates. The results show that the sharpest cube texture is obtained by cold rolling nickel and nickel tungsten alloys in passes of less than 5% deformation followed by annealing at high temperature.
High-frequency germinal transposition of DsALS in Arabidopsis. (1993)

We have established an efficient transposontagging system in Arabidopsis thaliana using the Activator/Dissociation (Ac/Ds) elements from maize. This system consists of two components, a stable trans-activator, Acst, that supplies transposase, and a cis-responsive Ds element. Ds and Acst were constructed with different selectable and screenable markers to facilitate monitoring of Ds excisions and insertions as well as segregation of Ds and Acst. Fusions of the 35S, rbcS, or CHS promoters to Ac transposase were used to trans-activate DsALS, a Ds element carrying an herbicide-resistance gene. The ALS gene encoding acetolactase synthase, which confers resistance to chlorsulfuron, functioned as a versatile marker for selection of plants grown in tissue culture as well as in soil. Thirty-five Acst lines were crossed to two DsALS lines, and the resulting progeny were assayed for germinal transposition of DsALS. Trans-activation of DsALS by Acst resulted in germinal excision frequencies of up to 64% when using 35S promoter-Ac transposase fusions, up to 67% when using rbcS-transposase fusions, and up to 1% when using CHS-transposase fusions. Amongst progeny bearing terminal excisions, Southern analysis revealed that 45% from 35S-Acst crosses and 29% from rbcS-Acst crosses carried reintegrated DsALS elements. The Ac/Ds system we have developed should prove to be an effective tool for stable gene tagging in Arabidopsis.
Multiple design point optimization of high-speed proprotors (1996)

Davis and G. J. Walker, Univ. of Tasmania, Australia, 1992, pp. 219-222. Standingford, D. W. R, Lazauskas, L. V., and Tuck, E. O., On the Numerics of the Lifting Surface Equation, Applied Mathematics Dept, Univ. of Adelaide, Adelaide, Australia, 1995. Tuck, E. O., Some Accurate Solutions of the Lifting Surface Equation, Journal of the Australian Mathematical Society (Series B), Vol. 35(2), Oct. 1993, pp. 127-144. Lan, C. E., A Quasi-Vortex-Lattice Method in Thin Wing Theory, Journal of Aircraft, Vol. 11, No. 9, 1974, pp. 518-527. ^urrill, D., Wings and Free Speed, Open Wheel Magazine, May 1992, p. 63.
A Combined Vector and Direct Power Control for DFIG-Based Wind Turbines (2014)

In this paper, a combined vector and direct power control (CVDPC) is proposed for the rotor side converter (RSC) of doubly fed induction generators (DFIGs). The control system is based on a direct current control by selecting appropriate voltage vectors from a switching table. In fact, the proposed CVDPC enjoys the benefits of vector control (VC) and direct power control (DPC) in a compacted control system. Its benefits in comparison with VC include fast dynamic response, robustness against the machine parameters variation, lower computation, and simple implementation. On the other hand, it has benefits in comparison with DPC, including less harmonic distortion and lower power ripple. An extensive simulation study, using MATLAB/Simulink, is conducted on a 9-MW wind farm composed of six 1.5-MW DFIG-based wind turbines. The performance of the proposed CVDPC method is compared with both VC and DPC under steady-state and transient conditions. Simulation results confirm the superiority of the CVDPC over either VC or DPC.
Resolution of coherent signals using a linear array (2005)

A high resolution algorithm for resolving closely spaced incident plane waves impinging on a linear array is presented. Unlike many existing "noise eigenvector" based methods, this "signal eigenvector" algorithm is not susceptible to the difficulties arising from coherent signal sources. A complete theoretical development of this algorithm is provided. Its improved performance relative to the spacial smoothed version of MUSIC is illustrated by simulated examples.
Longitudinal Determination of Serum Placental Protein 13 during Development of Preeclampsia (2008)

This preliminary study indicates that low levels of PP13 in early pregnancy identify at-risk pregnancies, whereas high levels precede the syndrome in late pregnancy and suggest syncytiotrophoblast necrosis.
Search committee seeks new AAP executive director (1992)

The AAP Executive Committee has appointed an eight-member search committee to seek a successor for retiring AAP Executive Director James Strain, M.D. The committee, chaired by AAP President Daniel Shea, M.D., represents a cross-section of AAP members and will be responsible for reviewing all applications, interviewing qualified candidates and making a final recommendation to the AAP Executive Board.
Synthesis and Characterization of New Poly(thieno[3,4-<i>d</i>]thiazole) Derivatives for Photovoltaic Applications (2011)

We report the synthesis of new push–pull conjugated polymers for bulk heterojunction solar cells based on benzo[1,2-b:4,5-b′]dithiophene (push) and thieno[3,4-d]thiazole (TTz) (pull) derivatives. Stille polycondensation between distannyl-BDT derivatives with 4,6-dibromo-2-octylthieno[3,4-d]thiazole led to two alternating copolymers, namely PBDTTTz-1 and PBDTTTz-2, which have a bandgap of 1.8 and 1.7 eV, respectively. Both copolymers are stable in air with HOMO energy level of −5.3 eV for PBDTTTz-1 and −5.4 eV for PBDTTTz-2. Both copolymers have been tested in bulk heterojunction solar cells, and preliminary results (without any optimization process) show promising power conversion efficiency of 1.4% for PBDTTTz-1 and 1.7% for PBDTTTz-2.
Wireline Coring and Analysis under Pressure: Recent Use and Future Developments of the HYACINTH System (2009)

<strong class="journal-contentHeaderColor">Abstract.</strong> No abstract available. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.7.07.2009" target="_blank">10.2204/iodp.sd.7.07.2009</a>
Catalytic multiecho phase unwrapping scheme (CAMPUS) in multiecho gradient echo imaging: Removing phase wraps on a voxel‐by‐voxel basis (2012)

Phase images reflect local field variations including susceptibility contributions and play a key role in a number of imaging applications. However, due to the limited dynamic range of phase values, phase wrapping invariably occurs at long echo times. High pass filtering and region-growing approaches have been common themes in the effort of removing phase wraps. In this article, a novel voxel-by-voxel phase unwrapping scheme taking advantage of short interecho spacing of multiecho gradient echo imaging is proposed. By removing spurious sources of phase variations and exploiting the special features of the flow-induced phase component, phase increments during adjacent echoes can be unveiled that exhibit no phase aliasing. This unaliased phase information is then used to unwrap all the phase images at all of the echoes. Data of 15 volunteers scanned at 3 and 1.5T were processed with the proposed algorithm and two other algorithms in the literature (PhUN and branch cut). It is shown that the proposed approach is fast and effective in unwrapping all the phase values even for voxels in the eyes and the skull, which the other algorithms failed to unwrap. Thus, in multiecho gradient echo imaging, the proposed algorithm has major potential in various applications involving phase processing.
The Alkali Metal Photoelectric Cell (1926)

In the development of the commercial system of picture transmission now in operation over certain of the Bell System lines, one of the initial problems was the choice of a method of transforming the light and shade of the picture to be transmitted into properties of an electric current. There are in general two methods of accomplishing this. The first, which we may term the photo-mechanical met hod, utilizes some photographic process to produce a mechanical structure, which may be used either to make and break contact, or to produce mechanical movement of some element whose motion produces a variable electric current. The second method consists in the utilization of some light sensitive device which produces or varies an electric current.