gebhart/patrepeval huggingface dataset:
Oscillatory fluxes in highly porous membranes (1974)

Abstract When a steady electric current is passed through a porous membrane which separates two electrolyte solutions at different concentrations the system can, in a suitable experimental configuration and when the current exceeds a critical value, enter a state of stable oscillations of the trans-membrane pressure and potential. In this system, sometimes called the Teorell membrane oscillator, the pressure driven and electro-osmotic flows are opposed. The former is almost independent of the concentration of the solution in the membrane pores; the latter is greater with dilute solutions than with concentrated ones. Oscillatory states can arise when pressure is applied to the concentrated side. Such states have been studied here by using, as membranes, Nuclepore filters which have readily characterized uniform, circular and parallel pores. Several pore sizes, concentrations and electrolytes have been examined. A theoretical treatment of the phenomenon has been developed by assuming that the relaxation rates of the concentration profiles in the membrane pores are large compared with the rates of change of the membrane boundary states during the oscillations. This assumption has permitted the stationary state theory (Meares & Page 1972) to be applied here also. Inertial forces are included but shown to be of little consequence at most times in the apparatus used here. Oscillations are a consequence of the nonlinear character of the equation relating fluid flow in the membrane to the imposed forces. A relatively satisfactory agreement between theory and experiment is found for pressure and potential limit cycles and for flow rates and periodic times. Imperfect mixing in the solution phases is an important complication. It is treated in the theory by the consideration of stagnant membrane boundary films. It appears that at the cycle limits, when the volume flow reverses, the rate of relaxation of these stagnant films may not be large compared with the rates of other processes. This distorts the voltage against time plots from their steady state forms and affects the oscillation times. Inertial and relaxation effects in the membrane at the cycle limits are masked by these effects in the stagnant films. It is suggested that the upper pressure limit may be depressed in practice by the influence of a few large pores which trigger a premature switch from electro-osmotic to hydrostatic pressure control.
Integration of Vibro‐Acoustography Imaging Modality with the Traditional Mammography (2007)

Vibro-acoustography (VA) is a new imaging modality that has been applied to both medical and industrial imaging. Integrating unique diagnostic information of VA with other medical imaging is one of our research interests. In this work, we establish correspondence between the VA images and traditional X-ray mammogram by adopting a flexible control-point selection technique for image registration. A modified second-order polynomial, which simply leads to a scale/rotation/translation invariant registration, was used. The results of registration were used to spatially transform the breast VA images to map with the X-ray mammography with a registration error of less than 1.65 mm. The fused image is defined as a linear integration of the VA and X-ray images. Moreover, a color-based fusion technique was employed to integrate the images for better visualization of structural information.
PHYSIOLOGICAL DEPENDENCE OF BRAIN METHIONINE AND <i>S</i>‐ADENOSYLMETHIONINE CONCENTRATIONS ON SERUM AMINO ACID PATTERN (1974)

Abstract— Animals maintained on rat chow and water ad libitum in quarters illuminated for 12 h/day show diurnal rhythms in serum methionine and brain S ‐adenosylmethionine (SAM) concentrations. Brain methionine exhibits no such variation, nor does the ratio of serum methionine to the serum concentrations of six neutral amino acids which are believed to compete with methionine for uptake into brain. Administration of methionine to rats in doses that elevate serum methionine, but keep it within the daily physiological range, significantly increases brain concentrations of both methionine and SAM. The acute feeding of either a protein‐free or a 40% casein meal also increases brain methionine and SAM, but does not affect serum methionine; however, both diets also increase the ratio of serum methionine to tyrosine, an amino acid whose postprandial concentration is indicative of the concentrations of the other amino acids that compete with methionine for transport into brain. These findings suggest that brain methionine levels increase physiologically after eating as a result of changes in the serum amino acid pattern. Furthermore, such naturally occurring increases in brain methionine appear to be associated with elevations in brain SAM.
A Low-Temperature Microscope Stage (1950)

A simple `cold chamber' is described for the optical observation of crystals below room temperature, under conditions relatively free from frosting. It is designed for the polarizing microscope with objectives up to × 20. The low temperatures are obtained by means of cooling gas from the evaporation of liquid air and they can be regulated to within ± 0.1° C. down to -140°C. by manual control of the heating elements.
Design of a subcutaneous implantable biochip for monitoring of glucose and lactate (2005)

The design, fabrication, and in-vitro evaluation of an amperometric biochip that is designed for the continuous in vivo monitoring of physiological analytes is described. The 2 /spl times/4 /spl times/0.5 mm biochip contains two platinum working enzyme electrodes that adopt the microdisc array design to minimize diffusional limitations associated with enzyme kinetics. This configuration permits either dual analyte sensing or a differential response analytical methodology during amperometric detection of a single analyte. The working enzyme electrodes are complemented by a large area platinized platinum counter electrode and a silver reference electrode. The biorecognition layer of the working electrodes was fabricated from around 1.0-/spl mu/m-thick composite membrane of principally tetraethylene glycol (TEGDA) cross-linked poly(2-hydroxyethyl methacrylate) that also contained a derivatized polypyrrole component and a biomimetic methacrylate component with pendant phosphorylcholine groups. These two additional components were introduced to provide interference screening and in vivo biocompatibility, respectively. This composite membrane was used to immobilize glucose oxidase and lactate oxidase onto both planar and microdisc array electrode designs, which were then used to assay for in vitro glucose and lactate, respectively. The glucose biosensor exhibited a dynamic linear range of 0.10-13.0 mM glucose with a response time (t/sub 95/) of 50 s. The immobilized glucose oxidase within the hydrogel yielded a K/sub m(app)/ of 35 mM, not significantly different from that for the native, solution-borne enzyme (33 mM). The microdisc array biosensor displayed linearity for assayed lactate up to 90 mM, which represented a 30-fold increase in linear dynamic lactate range compared to the biosensor with the planar electrode configuration. Preliminary in vitro operational stability tests performed with the microdisc array lactate biosensor demonstrated retention of 80% initial biosensor response after five days of continuous operation in buffer under physiologic conditions of pH and temperature.
Use of degenerate primers for polymerase chain reaction cloning and sequencing of the Lactococcus lactis subsp. lactis recA gene (1992)

Two particularly well-conserved stretches in the RecA protein sequences were chosen as templates to synthesize degenerate oligonucleotides, which were used in polymerase chain reaction to amplify an internal recA DNA fragment of Lactococcus lactis subsp. lactis ML3. Using this fragment, we recovered and sequenced the entire lactococcal recA gene. The end of an open reading frame present upstream of the recA gene shows strong homology with formamidopyrimidine-DNA-glycosylase, a protein involved in DNA repair.
Growth and Gibberellin A<sub>1</sub> Metabolism in Excised Lettuce Hypocotyls (1977)

Excised lettuce (Lactuca sativa L. cv. Arctic) hypocotyls retain the ability to elongate in response to exogenously supplied gibberellic acid and gibberellin A(1) (GA(1)). We have studied the relationship between metabolism of GA(1) and elongation in this tissue. In 24 hours at 28 C, hypocotyls treated with 3 mum GA(1) double in length while controls elongate less than 45%. After an exogenous hormone supply is removed, hypocotyls continue to grow faster than untreated controls, although as the hormone application time is decreased, the GA(1) concentration required to effect a given length change increases. [(3)H]GA(1) was used to determine rates of hormone uptake, efflux, and metabolism. In the presence of [(3)H]GA(1), hypocotyls accumulate and metabolize lable for at least 24 hours. When the exogenous label is removed, the amount of acidic GA in the hypocotyl declines rapidly to a constant level while ethyl acetate-insoluble metabolites increase rapidly to a constant level. Lable accumulation and metabolism at any time are proportional to the external GA(1) concentration below 50 mum GA(1). Chromatographic analysis of radioactive compounds present in tissue extracts suggests that unaltered GA(1) is the major component of the acidic ethyl acetate-soluble fraction, and gibberellin A(8) is a minor component. The ethyl acetate-insoluble fraction appears to contain an unidentified GA(1) metabolite with chromatographic properties similar to those of GA(1). The strong retention of accumulated GA(1) confirms the possibility of a continuing requirement for GA(1) during the sustained response to a GA(1) "pulse" but raises the question of accessibility of the stored hormone for growth promotion.
Subjective assessment of cable impairments on television picture quality (1992)

The subjective assessment of NTSC television pictures that have been subjected to a number of levels of commonly encountered cable-system impairments is discussed. The impairments included random noise, phase noise, microreflections, composite triple beat, and chroma/luma or group delay. The evaluations were performed in controlled-viewing experiments using psychological test methods with both expert and nonexpert viewers. The tests evaluated picture impairments, using the CCIR impairment scale with terms describing a continuum of annoyance. A comparison of the random noise test results with data from earlier similar studies in 1958 and 1983 demonstrates a continuing rise in view expectations for improved picture quality.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Wavefront control in space with MEMS deformable mirrors for exoplanet direct imaging (2013)

To meet the high contrast requirement of 1×10 −10 to image an Earth-like planet around a sun-like star, space telescopes equipped with coronagraphs require wavefront control systems. Deformable mirrors (DMs) are a key element of a wavefront control system, as they correct for imperfections, thermal distortions, and diffraction that would otherwise corrupt the wavefront and ruin the contrast. The goal of the CubeSat DM technology demonstration mission is to test the ability of a microelectromechanical system (MEMS) DM to perform wavefront control on-orbit on a nanosatellite platform. We consider two approaches for an MEMS DM technology demonstration payload that will fit within the mass, power, and volume constraints of a CubeSat: (1) a Michelson interferometer and (2) a Shack-Hartmann wavefront sensor. We clarify the constraints on the payload based on the resources required for supporting CubeSat subsystems drawn from subsystems that we have developed for a different CubeSat flight project. We discuss results from payload laboratory prototypes and their utility in defining mission requirements.
The Test Support Program (TSP) a real-time interactive simulation system (1976)

The Test Support Program (TSP) is a real-time interactive computer-based simulation model that provides the environment for testing and verifying the operation of netted air control systems. It provides computer-to-computer simulation of data link timing; message interpretation, response, and transmission; and on-line data analysis and recording for up to nine interfaced systems of various types.
A New Dynamic Method for Detection of Internal Jugular Valve Incompetence Using Air Contrast Ultrasonography (1999)

The internal jugular (IJ) valve is the only valve between the heart and the brain, preventing venous reflux into the IJ vein. Internal jugular valve competence has been tested by IJ venography. Doppler ultrasonography of the IJ vein and M-mode ultrasonography of the IJ valve, and color flow imaging (CFI) of the IJ vein. However, interpretation of venous Doppler and CFI is difficult, and venography is invasive. The purpose of this study was to evaluate the feasibility of a new dynamic method to test IJ valve competency, and to review the literature regarding the potential clinical importance of this pathophysiology. Ten patients had intravenous injection of agitated air and saline during Valsalva maneuver with B-mode monitoring and CFI of the right IJ vein. Contrast bubbles were clearly identified refluxing into the right IJ vein in 50% of patients. Air contrast studies more often showed IJ valve incompetence than CFI. Bubbles appeared in the IJ vein within 19.2 sec and persisted up to 282 sec. Bubble aggregation was also observed. There was no correlation between positive bubbles and the presence of spontaneous echo contrast on baseline B-mode imaging. Air contrast ultrasound venography (ACUV) is a new noninvasive method to assess competency of the IJ valves. This technique is feasible, appears to be more sensitive than CFI, and adds a new dimension to the study of the venous system in cerebrovascular disease. Potential clinical application includes evaluation of patients with increased central venous pressure, those with morning headaches, and those on positive end-expiratory pressure ventilators.
<i>Phaseolus vulgaris</i> leucoagglutinin (PHA‐L): A neuroanatomical tracer for electron microscopic analysis of synaptic circuitry in the cat's dorsal lateral geniculate nucleus (1990)

Phaseolus vulgaris leucoagglutinin (PHA-L) is a plant lectin that is anterogradely transported by neurons in the central nervous system. PHA-L is selectively taken up by cells at iontophoretic injection sites and, when immunohistochemically demonstrated, labels individual neurons completely, including their dendrites, axons, and terminal boutons. PHA-L is generally not taken up by fibers passing through the injection site and, because it produces a Golgi-like staining of even very fine axons over long distances, it is sometimes possible to light microscopically reconstruct individual neurons and their entire axon terminal arbors. When prepared for electron microscopy, the PHA-L-labeled terminals are densely and completely stained, allowing their synaptic relationships to be defined. These properties make PHA-L advantageous for studying the patterns of projection and the modes of termination of select groups of neurons in their target nuclei. We used PHA-L to study the extraretinal innervation of the cat's dorsal lateral geniculate nucleus, a thalamic visual center. Although much is known about the retinal contribution to geniculate synaptic circuitry, relatively little is known about other sources of innervation, even though these provide the majority of synaptic terminals in the nucleus (Guillery: Z. Zellforsch., 96:1-38, 39-48, 1969; Wilson et al.: Proc. R. Soc. Lond. [Biol.], 221:441-436, 1984). We used both light and electron microscopy to describe synaptic circuitry from three extraretinal sources of projections to the lateral geniculate nucleus: the visual cortex, the perigeniculate nucleus, and the parabrachial region of the brainstem. Cortical terminals labeled with PHA-L were small and formed asymmetrical synaptic contacts onto small-caliber dendrites of geniculate neurons. Perigeniculate terminals formed symmetrical synaptic contacts primarily onto small-caliber dendrites, but some synapses were also formed onto the proximal, retinorecipient portions of geniculate dendrites. Parabrachial terminals synaptically contacted the retinorecipient portions of dendritic appendages and shafts, small-caliber dendrites, and the specialized dendritic (F2) terminals of geniculate interneurons. The symmetry of the parabrachial synaptic contacts was variable and was related to the postsynaptic target. Contacts onto dendritic appendages were asymmetrical while those onto dendritic shafts and F2 terminals were symmetrical. Our data suggest that in unlabeled material these brainstem terminals would be difficult to distinguish from cortical or perigeniculate profiles. The positioning of the parabrachial input onto the retinorecipient portions of geniculate dendrites indicates that this projection is well situated to control primary retinal transmission through the nucleus, while the location of most cortical and perigeniculate innervations implicates them in secondary feedback interactions or other aspects of geniculate function.
Design, Modeling, and Analysis of a Compact Planar Transformer (2012)

This paper presents a new design of a planar transformer. Over the surface of a flat core, meander-type design was engraved, so that symmetrically adjusted primary and secondary coils, of the same meander-type, can fit into the engraved design. Primary and secondary coils were covered with another flat core consequently forming a compact planar transformer. Windings of primary and secondary coils are printed on both sides of PCB. Conductive stripes of a winding from upper and bottom layer are connected by vias. The transformer was analyzed when the primary and secondary coils were without a core and with a core. High frequency parameters of the transformer were obtained by finite element modeling software and Impedance Analyzer HP4194A in the frequency range from 50 kHz to 1 MHz. The transformer is intended to be used in DC-DC converters (for switching frequency up to several hundred kHz).
Antimicrobial activity and mechanism of action of Nu-3, a protonated modified nucleotide (2011)

These results provide additional experimental data that are consistent with the hypothesis that Nu-3 represents a new class of antibacterial agents for treating topical infections and acts via a different mechanism from conventional antibiotics.
<title>E-O framing camera flight test results</title> (1994)

Recon/Optical, Inc. (ROI) has developed the CA-260 Advanced Development E-O Framing Camera specifically to provide near-photographic quality images while enhancing the survivability of the tactical reconnaissance platforms at low to medium altitudes. The CA-260, mounted in a T-33 jet trainer, completed three successful engineering flight tests over the Edwards AFB test range on July 17 - 31, 1993. The flight tests were part of ROI's research and development program to develop E-O framing camera technology. These tests marked a major milestone in the program and proved that an E-O framing camera can successfully perform tactical reconnaissance missions. This paper presents the details of the engineering flight tests performed at Mojave, Calif. By way of introduction, the concept of E-O framing tactical reconnaissance and its advantages in terms of aircraft survivability are reviewed. The purpose, equipment configuration, mission specifics and flight summaries are discussed. Examples of flight test imagery are presented with some analysis of the CA-260's performance.
INVESTIGATIONS OF ISOLATION IMPROVEMENT TECHNIQUES FOR MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) WLAN PORTABLE TERMINAL APPLICATIONS (2008)

Various isolation improvement techniques for MIMO WLAN card bus applications consisted of three closely spaced loop antennas are presented and investigated both numerically and experimentally in this paper. The proposed techniques are easily implemented and proven effective to achieve high isolation among the antennas which is a must for MIMO terminals to receive uncorrelated signals with good system throughputs.
Physical, mineralogical, and durability studies on the building and monumental granites of the United States (1940)

Tests on 116 samples of granite (including the "black granites") from the principal producing districts of the United States gave range values for various physical properties, as foll ows: Compressive str ength, 7,700 to 53,800 Ib/in.2; absorption (48-hr immersion), 0.02 to 0.58 percent; porosity, 0.40 to 3.84 percent; weights per cubic foot, 157 to 187 lb. The "black granites" (gabbros and basalts) were indicated to be stron ger, denser, and less absorptive than the normal granites. Tests on a few select ed samples gave a range of values for shearing strength of 3,900 to 4,600 Ib/in . 2 ; modulus of rupture, 1,430 to 5,190 Ib/in.2 ; abrasive hardn ess, (Ha) 37 to 88; toughness, 8 to 27.
Representing circuits more efficiently in symbolic model checking (1991)

Article Representing circuits more efficiently in symbolic model checking Share on Authors: J. R. Burch School of Computer Science, Carnegie Mellon University School of Computer Science, Carnegie Mellon UniversityView Profile , E. M. Clarke School of Computer Science, Carnegie Mellon University School of Computer Science, Carnegie Mellon UniversityView Profile , D. E. Long School of Computer Science, Carnegie Mellon University School of Computer Science, Carnegie Mellon UniversityView Profile Authors Info & Claims DAC '91: Proceedings of the 28th ACM/IEEE Design Automation ConferenceJune 1991 Pages 403–407https://doi.org/10.1145/127601.127702Online:01 June 1991Publication History 134citation365DownloadsMetricsTotal Citations134Total Downloads365Last 12 Months6Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access
DECT standardisation: status and future activities (2002)

The standardisation of DECT in ETSI has been very productive, the DECT standard is one of the first to be completed. The basic DECT standards were approved in 1992 after which type approval (regulatory) standards were made (approved 1993/1994). During the last year the focus of standardisation has shifted towards application standards, e.g. DECT/GSM and DECT/ISDN Interworking Profiles. One of the latest developments in DECT has been the Generic Access Profile, which ensures full interoperability.
Lithium Insertion in Hydrogen-Containing Carbonaceous Materials (1996)

Heated carbon materials were made from organic precursors between 550 and 1000 °C. High capacities for lithium were found in all of the samples heated below 800 °C, which all contain substantial hydrogen. The majority of this high capacity shows large hysteresis; that is the lithium is inserted near 0 V (versus lithium metal) and removed near 1 V. We show that the capacity exhibiting large hysteresis is proportional to the hydrogen content of the samples. We believe that lithium atoms can bind quasi-reversibly on hydrogen-terminated edges of graphene fragments in carbonaceous materials.