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1

Ar I and Ne I spectral line shapes for an abnormal glow discharge diagnostics  

NASA Astrophysics Data System (ADS)

We report the results of an Ar I and Ne I line shape study in an abnormal glow discharge operating in argon and neon. The spectral lines were observed along the axis of a cylindrical glow discharge parallel (side-on) and perpendicular (end-on) to the cathode surface. The side-on spectra show spectral line shifting and sometimes simultaneous shifting and splitting in the cathode fall region of the glow discharge. The results of the measured line shift with available data for the dc Stark effect are used for measurement of electric field strength in the cathode fall region of the glow discharge. Electron temperatures of 2860 K and 4770 K in the negative glow region of argon and neon discharges, respectively, were determined from the relative intensities of Ar I or Ne I lines using the Boltzmann plot technique. An electron number density of ?1020 m-3 (±25%) in the negative glow region of the argon discharge was determined from the widths of two plasma-broadened Ar I lines using theoretical Stark broadening data. The end-on recorded line profiles show 10-40% larger half-widths than the side-on recorded line profiles from the negative glow. This effect is a result of the superposition of line emission in the cathode fall region under the influence of the dc Stark effect on the line profile from the negative glow.

Majstorovi?, G. Lj; Ivanovi?, N. V.; Šišovi?, N. M.; Djurovi?, S.; Konjevi?, N.

2013-08-01

2

The Evolution of Cone-Like Formations on The Cathode of Abnormal Glow Discharge of Ar  

NASA Astrophysics Data System (ADS)

The paper presents results of experimental studies and theoretical description of processes that occur during modification of cathode surface in glow discharge of Ar. The model is proposed for the experimentally observed phenomenon of the cone like microprotrusions growth. We consider the case when a strong electric field stipulated by the cathode layer of abnormal glow discharge was taken into consideration during sputtering. The model takes into account most important physical phenomena that accompany modification of the cathode surface in glow discharge. Within the framework of the model an analytical solution of the equation that describes the dynamics of surface microprofile evolution is obtained. From the analysis of this solution the evolution of cone microbulges on the cathode surface of metal in glow gas discharge is described.

Bobkov, V. V.; Alimov, S. S.; Andreiev, V. V.; Slyusarenko, Yu. V.; Starovoitov, R. I.

2003-06-01

3

Doppler spectroscopy of hydrogen and deuterium Balmer alpha line in an abnormal glow discharge  

Microsoft Academic Search

The results of hydrogen and deuterium Balmer alpha line shapes and line intensities study in an abnormal glow discharge are reported and analyzed. The Doppler shifts along line wings are used to determine energies of excited hydrogen and deuterium atoms. For 12 different cathodes, intensity and shape of line wings are examined and dependence upon cathode material is determined. Tentative

M. R. Gemisic Adamov; Bratislav M. Obradovic; Milorad M. Kuraica; N. Konjevic

2003-01-01

4

Array of surface-confined glow discharges in atmospheric pressure helium: Modes and dynamics  

NASA Astrophysics Data System (ADS)

Array of atmospheric pressure surface discharges confined by a two-dimensional hexagon electrode mesh is studied for its discharge modes and temporal evolution so as to a theoretical underpinning to their growing applications in medicine, aerodynamic control, and environmental remediation. Helium plasma surface-confined by one hexagon-shaped rim electrode is shown to evolve from a Townsend mode to a normal and abnormal glow mode, and its evolution develops from the rim electrodes as six individual microdischarges merging in the middle of the hexagon mesh element. Within one hexagon element, microdischarges remain largely static with the mesh electrode being the instantaneous cathode, but move towards the hexagon center when the electrode is the instantaneous anode. On the entire array electrode surface, plasma ignition is found to beat an unspecific hexagon element and then spreads to ignite surrounding hexagon elements. The spreading of microdischarges is in the form of an expanding circle at a speed of about 3 × 104 m/s, and their quenching starts in the location of the initial plasma ignition. Plasma modes influence how input electrical power is used to generate and accelerate electrons and as such the reaction chemistry, whereas plasma dynamics are central to understand and control plasma instabilities. The present study provides an important aspect of plasma physics of the atmospheric surface-confined discharge array and a theoretical underpinning to its future technological innovation.

Li, D.; Liu, D. X.; Nie, Q. Y.; Li, H. P.; Chen, H. L.; Kong, M. G.

2014-05-01

5

Common procedural execution failure modes during abnormal situations  

Microsoft Academic Search

The Abnormal Situation Management® Consortium11This research study was sponsored by the Abnormal Situation Management® (ASM®) Consortium. ASM and Abnormal Situation Management are registered trademarks of Honeywell International, Inc. funded a study to investigate procedural execution failures during abnormal situations. The study team analyzed 20 publically available and 12 corporate confidential incident reports using the TapRoot® methodology to identify root causes

Peter T. Bullemer; Liana Kiff; Anand Tharanathan

2011-01-01

6

Glow Dog Glow  

E-print Network

Broadcast Transcript: South Korean researchers, ever striving to be top in science, have cloned a glow-in-the-dark dog. The little beagle was engineered by inserting genes from species--like jellyfish--that produce fluorescent proteins. The gene...

Hacker, Randi

2011-08-17

7

Abnormal high-$Q$ modes of coupled stadium-shaped microcavities  

E-print Network

It is well known that the strongly deformed microcavity with fully chaotic ray dynamics cannot support high-Q modes due to its fast chaotic diffusion to the critical line of refractive emission. Here, we investigate how the Q factor is modified when two chaotic cavities are coupled, and show that some modes, whose Q factor is about 10 times higher than that of the corresponding single cavity, can exist. These abnormal high-Q modes are the result of an optimal combination of coupling and cavity geometry. As an example, in the coupled stadium-shaped microcavities, the mode pattern extends over both cavities such that it follows a whispering-gallery-type mode at both ends, whereas a big coupling spot forms at the closest contact of the two microcavities. The pattern of such a 'rounded bow tie' mode allows the mode to have a high-Q factor. This mode pattern minimizes the leakage of light at both ends of the microcavities as the pattern at both ends is similar to whispering gallery mode.

Jung-Wan Ryu; Soo-Young Lee; Inbo Kim; Muhan Choi; Martina Hentschel; Sang Wook Kim

2014-08-20

8

Abnormal high-$Q$ modes of coupled stadium-shaped microcavities  

E-print Network

It is well known that the strongly deformed microcavity with fully chaotic ray dynamics cannot support high-Q modes due to its fast chaotic diffusion to the critical line of refractive emission. Here, we investigate how the Q factor is modified when two chaotic cavities are coupled, and show that some modes, whose Q factor is about 10 times higher than that of the corresponding single cavity, can exist. These abnormal high-Q modes are the result of an optimal combination of coupling and cavity geometry. As an example, in the coupled stadium-shaped microcavities, the mode pattern extends over both cavities such that it follows a whispering-gallery-type mode at both ends, whereas a big coupling spot forms at the closest contact of the two microcavities. The pattern of such a 'rounded bow tie' mode allows the mode to have a high-Q factor. This mode pattern minimizes the leakage of light at both ends of the microcavities as the pattern at both ends is similar to whispering gallery mode.

Ryu, Jung-Wan; Kim, Inbo; Choi, Muhan; Hentschel, Martina; Kim, Sang Wook

2014-01-01

9

Abnormal lateralization of functional connectivity between language and default mode regions in autism  

PubMed Central

Background Lateralization of brain structure and function occurs in typical development, and abnormal lateralization is present in various neuropsychiatric disorders. Autism is characterized by a lack of left lateralization in structure and function of regions involved in language, such as Broca and Wernicke areas. Methods Using functional connectivity magnetic resonance imaging from a large publicly available sample (n?=?964), we tested whether abnormal functional lateralization in autism exists preferentially in language regions or in a more diffuse pattern across networks of lateralized brain regions. Results The autism group exhibited significantly reduced left lateralization in a few connections involving language regions and regions from the default mode network, but results were not significant throughout left- and right-lateralized networks. There is a trend that suggests the lack of left lateralization in a connection involving Wernicke area and the posterior cingulate cortex associates with more severe autism. Conclusions Abnormal language lateralization in autism may be due to abnormal language development rather than to a deficit in hemispheric specialization of the entire brain. PMID:24502324

2014-01-01

10

Modifying argon glow discharges by hydrogen addition: effects on analytical characteristics of optical emission and mass spectrometry detection modes.  

PubMed

An overview of the effects produced by the presence of hydrogen in a glow discharge (GD), generated either in argon or in neon, is given. Extensive work related to the addition of hydrogen to GDs, coupled with optical emission spectrometry (OES) and mass spectrometry (MS), has been published in the last few years in an attempt to explain the processes involved in the discharge of mixed gases. Although numerous experimental results have already been explained theoretically, a complete understanding of the effects brought about by mixing hydrogen with argon (or another discharge inert gas) has not been reported yet. The use of theoretical models implemented using a computer has allowed the importance of some collisional and radiative processes in the inert gas plasma when hydrogen is present to be evaluated. This review shows, however, that both experimental work and theoretical work are still needed. The influence of small quantities of hydrogen on discharge parameters, such as electrical current or dc bias voltage, on crater shapes and on sputtering rates is thoroughly reviewed along with the effect on the analytical signals measured by OES and MS. Also, hydrogen-effect corrections needed to carry out proper calibrations for direct solid quantitative analyses are discussed. PMID:17468855

Martín, A; Menéndez, A; Pereiro, R; Bordel, N; Sanz-Medel, A

2007-08-01

11

Abnormal Default-Mode Network Homogeneity in First-Episode, Drug-Naive Major Depressive Disorder  

PubMed Central

Background Default mode network (DMN) is one of the most commonly recognized resting-state networks in major depressive disorder (MDD). However, the homogeneity of this network in MDD is poorly understood. As such, this study was conducted to determine whether or not an abnormal network homogeneity (NH) of DMN is observed in patients with first-episode and drug-naive MDD. Methods Twenty-four first-episode drug-naive patients with MDD and twenty-four healthy control subjects participated in the study. NH and independent component analysis (ICA) methods were used to analyze data. Results Depressed patients exhibited a significantly increased NH in the left dorsal medial prefrontal cortex (MPFC) and decreased NH in the right inferior temporal gyrus (ITG) compared with the healthy control subjects. Receiver operating characteristic curves (ROC) were analyzed and results revealed that the NH values of MPFC and ITG could be applied as candidate markers with relatively high sensitivity and specificity to distinguish patients from healthy control subjects. No correlation was observed between the NH values of the two regions and clinical variables. Conclusions Our findings suggested that an abnormal DMN homogeneity could be observed in MDD, which highlight the importance of the DMN in the pathophysiology of MDD. PMID:24609111

Guo, Wenbin; Liu, Feng; Zhang, Jian; Zhang, Zhikun; Yu, Liuyu; Liu, Jianrong; Chen, Huafu; Xiao, Changqing

2014-01-01

12

Multiple solutions in the theory of dc glow discharges  

NASA Astrophysics Data System (ADS)

Multiple steady-state solutions existing in the theory of dc glow discharges are computed for the first time. The simulations are performed in 2D in the framework of the simplest self-consistent model, which accounts for a single ion species and employs the drift-diffusion approximation. Solutions describing up to nine different modes were found in the case where losses of the ions and the electrons due to diffusion to the wall were neglected. One mode is 1D, exists at all values of the discharge current, and represents in essence the well-known solution of von Engel and Steenbeck. The other eight modes are axially symmetric, exist in limited ranges of the discharge current, and are associated with different patterns of current spots on the cathode. The mode with a spot at the centre of the cathode exhibits a well pronounced effect of normal current density. Account of diffusion losses affects the solutions dramatically: the number of solutions is reduced, a mode appears that exists at all discharge currents and comprises the Townsend, subnormal, normal and abnormal discharges. The solutions that exist in limited current ranges describe patterns, and these patterns seem to represent axially symmetric analogues of the 3D patterns observed in dc glow microdischarges in xenon.

Almeida, P. G. C.; Benilov, M. S.; Faria, M. J.

2010-04-01

13

Thar She Glows!  

NSDL National Science Digital Library

Learners observe glow-in-the-dark objects in a homemade light-proof box. Objects can include glow sticks, glow-in-the-dark toys, and toys with fluorescent paint. The box is built with a black light installed, which can be controlled with a switch outside the box. Background information is provided about the difference between fluorescence (glows only when light is shined on it) and phosphorescence (continues to glow after light is removed), and an electron-level explanation is also provided.

Industry, Oregon M.

1997-01-01

14

Phenomena of oscillations in atmospheric pressure direct current glow discharges  

SciTech Connect

Self-sustained oscillations in a dc glow discharge with a semiconductor layer at atmospheric pressure were investigated by means of a one-dimensional fluid model. It is found that the dc glow discharge initially becomes unstable in the subnormal glow region and gives rise to oscillations of plasma parameters. A variety of oscillations with one or more frequencies have been observed under different conditions. The discharge oscillates between the glow discharge mode and the Townsend discharge mode in the oscillations with large amplitude while operates in the subnormal glow discharge mode all the while in the oscillations with small amplitude. Fourier Transform spectra of oscillations reveal the transition mechanism between different oscillations. The effects of semiconductor conductivity on the oscillation frequency of the dominant mode, gas voltage, as well as the discharge current have also been analyzed.

Liu, Fu-cheng [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)] [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Yan, Wen; Wang, De-zhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-12-15

15

Glowing in the Dark  

NSDL National Science Digital Library

In this activity, learners explore phosphorescence and how certain materials can absorb and store energy from a light source. Learners use critical thinking skills to hypothesize which type of light -- incandescent, ultraviolet, infrared or fluorescent -- will produce the brightest glow from a glow-in-the-dark star. Learners perform an experiment using cameras to observe the intensity of the resulting glow from each type of light source.

Friday, Science

2011-01-01

16

Glow discharge detector  

DOEpatents

A highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured.

Koo, Jackson C. (San Ramon, CA); Yu, Conrad M. (Antioch, CA)

2002-01-01

17

Abnormal functional connectivity of default mode sub-networks in autism spectrum disorder patients  

PubMed Central

Autism spectrum disorders (ASDs) are characterized by deficits in social and communication processes. Recent data suggest that altered functional connectivity (FC), i.e. synchronous brain activity, might contribute to these deficits. Of specific interest is the FC integrity of the default mode network (DMN), a network active during passive resting states and cognitive processes related to social deficits seen in ASD, e.g. Theory of Mind. We investigated the role of altered FC of default mode sub-networks (DM-SNs) in 16 patients with high-functioning ASD compared to 16 matched healthy controls of short resting fMRI scans using independent component analysis (ICA). ICA is a multivariate data-driven approach that identifies temporally coherent networks, providing a natural measure of FC. Results show that compared to controls, patients showed decreased FC between the precuneus and medial prefrontal cortex/anterior cingulate cortex, DMN core areas, and other DM-SNs areas. FC magnitude in these regions inversely correlated with the severity of patients' social and communication deficits as measured by the Autism Diagnostic Observational Schedule and the Social Responsiveness Scale. Importantly, supplemental analyses suggest that these results were independent of treatment status. These results support the hypothesis that DM-SNs under-connectivity contributes to the core deficits seen in ASD. Moreover, these data provide further support for the use of data-driven analysis with resting-state data for illuminating neural systems that differ between groups. This approach seems especially well suited for populations where compliance with and performance of active tasks might be a challenge, as it requires minimal cooperation. PMID:20621638

Assaf, Michal; Jagannathan, Kanchana; Calhoun, Vince D.; Miller, Laura; Stevens, Michael C.; Sahl, Robert; O'Boyle, Jacqueline G.; Schultz, Robert T.; Pearlson, Godfrey D.

2011-01-01

18

Chromosomal Abnormalities Chromosomal abnormalities  

E-print Network

Lecture 6 Chromosomal Abnormalities #12;Chromosomal abnormalities Numeric Polyploidy- abnormal # of chromosome sets Aneuploidy- abnormal chromosome number Structural Deletion syndromes Duplications Ring chromosomes Centromeric fusions (Robertsonian translocations) Insertion Inversion Paracentric Pericentric

Dellaire, Graham

19

Numerical Study on Glow Discharge of IEC Fusion  

SciTech Connect

An inertial electrostatic confinement (IEC) fusion device is possibly used for the neutron source that has the ability to produce the neutrons of 10{sup 5}-10{sup 8}/s by the glow discharge. It works more efficiently at the condition of the high voltage and the low pressure. It, however, is difficult to keep the continuous operation at the low-pressure because the glow discharge is apt to be unstable. We have made the three-dimensional Monte Carlo PIC code including atomic processes to investigate the glow discharge. The study reveals the spatial position where the ionization occurs and numerically reproduces the discharge called 'star mode'.

Osawa, Hodaka; Tabata, Takehiro; Ohnishi, Masami [Kansai University (Japan)

2005-05-15

20

Glowing Bacteria: Transformation Efficiency  

E-print Network

took up and expressed GFP after transformation. Background: Transformation efficiency is a quantitative1 Glowing Bacteria: Transformation Efficiency Purpose: To determine how well your E. coli cells. The number represents how many cells were transformed per microgram (µg) of plasmid DNA used

Rose, Michael R.

21

Glow-discharge-created electron beams and beam-excited lasers  

SciTech Connect

Efficiently created glow discharge electron beams have been developed and studied in detail. The beam mode of operation occurs in the abnormal glow adjacent to the glow-to-arc transition regime. In contrast to electron beams generated in high vacuum from thermionic electron emitting sources, this type of discharge creates electrons directly in soft vacuum by secondary electron emission from cold cathode surfaces following the bombardment of the cathode surface by fast ions and neutral atoms. Factors influencing the efficient electron emission from cold cathodes are presented with emphasis on cathode materials. Sintered ceramic-metal cathodes and oxide-coated cathodes are presented, both of which can produce high power, efficiently generated, d.c. electron beams with discharge currents up to 1 amp ({approx}130 mA/cm{sup 2}) at volt ages of up to 6 kV. Novel cathode designs and discharge geometries are presented with specific emphasis on both self-focussed beams emitted from circular cathodes and line-source electron beams emitted from rectangular cathodes forming a thin sheet of electrons. Electrostatically focussed line-source electron beams are spatially characterized by experimentally measuring the effect of discharge parameters and cathode design upon the focussed beam width, focal point, and uniformity. This is achieved by scanning a current collecting detector in three dimensions in order to profile the distribution of electron beam current. Discharge electron beams are further characterized by their electron energy distribution. Measured electron flux energy distributions of transmitted beam electrons in the negative glow are compared to theoretical models. The relative effects of elastic and inelastic collisions mechanisms upon both the overall form and detailed structure of the energy distribution are discussed.

Meyer, J.D.

1989-01-01

22

Excessive hydrogen and deuterium Balmer lines broadening in a hollow cathode glow discharges  

Microsoft Academic Search

Results of a Doppler spectroscopy study of hydrogen and deuterium Balmer lines in the stainless steel and copper hollow cathode glow discharge, operated in pure hydrogen, deuterium and mixtures of inert gases with hydrogen, are reported. For all gases and gas mixtures plasma observations perpendicular to electric field revealed the excessively large Doppler broadening. By changing mode of glow discharge

N. M. Sisovic; G. Lj. Majstorovic; N. Konjevic

2005-01-01

23

Abnormally low electron energy and heating-mode transition in a low-pressure argon rf discharge at 13. 56 MHz  

Microsoft Academic Search

The electron energy distribution function measured with improved energy resolution revealed a large number (â90%) of low-energy electrons having an abnormally low electron temperature ({ital T}â0.3 V) resulting in a considerably lower mean electron energy than found in all published probe measurements in argon rf discharges at 13.56 MHz. With increasing gas pressure an abrupt transition to a high-temperature mode

V. A. Godyak; R. B. Piejak

1990-01-01

24

Powerful glow discharge excilamp  

DOEpatents

A powerful glow discharge lamp comprising two coaxial tubes, the outer tube being optically transparent, with a cathode and anode placed at opposite ends of the tubes, the space between the tubes being filled with working gas. The electrodes are made as cylindrical tumblers placed in line to one other in such a way that one end of the cathode is inserted into the inner tube, one end of the anode coaxially covers the end of the outer tube, the inner tube penetrating and extending through the anode. The increased electrodes' surface area increases glow discharge electron current and, correspondingly, average radiation power of discharge plasma. The inner tube contains at least one cooling liquid tube placed along the axis of the inner tube along the entire lamp length to provide cathode cooling. The anode has a circumferential heat extracting radiator which removes heat from the anode. The invention is related to lighting engineering and can be applied for realization of photostimulated processes under the action of powerful radiation in required spectral range.

Tarasenko, Victor F. (Tomsk, RU); Panchenko, Aleksey N. (Tomsk, RU); Skakun, Victor S. (Tomsk, RU); Sosnin, Edward A. (Tomsk, RU); Wang, Francis T. (Danville, CA); Myers, Booth R. (Livermore, CA); Adamson, Martyn G. (Danville, CA)

2002-01-01

25

Detection of surface glow related to spacecraft glow phenomenon  

SciTech Connect

We have developed a high flux source of low energy neutral beams to study the spacecraft glow phenomena by using a biased limiter to neutralize plasma in ACT-1. Beams of nitrogen and nitrogen-oxygen mixtures with energies of 1 to 15 eV and fluxes greater than or equal to 10/sup 14//cm/sup 2//s were directed on target surfaces consisting of Z-302 and Z-306 paints. With the nitrogen beams we successfully detected a glow due to beam-surface interactions. In addition, we discovered a volume glow effect due to beam-gas interactions which may also play a role in spacecraft glow. 11 refs., 14 figs.

Langer, W.D.; Cohen, S.A.; Manos, D.M.; Motley, R.W.; Ono, M.; Paul, S.; Roberts, D.; Selberg, H.

1986-02-01

26

MODE OF ACTION: NEUROTOXICITY INDUCED BY DEVELOPMENTAL THYROID HORMONE INSUFFICIENCY -- NEUROLOGICAL ABNORMALITIES RESULTING FROM EXPOSURE TO PROPYLTHIOURACIL.  

EPA Science Inventory

A manuscript summarizes a workshop aimed at developing a framework to determine the relevancy of animal modes-of-action for extrapolation to humans. This specific report used animal data on neurodevelopmental effects of thyroid hormone disruption to test the framework. Polyhaloge...

27

Simulation of Direct-Current Air Glow Discharge Phenomena  

NASA Astrophysics Data System (ADS)

Surface plasma discharges are of increasing interest as actuators for flow control. Non-equilibrium glow discharges are particularly attractive for flow actuation since they have significantly lower power requirements compared to other discharges such as thermal arcs. While volumetric heating and electrostatic forcing can be important for flow actuation, the relative importance of each of these mechanisms needs to be understood. In this work develop a 2D computational model of air glow discharges in parallel-plate DC discharge under conditions similar to plasma flow actuator applications. The model is validated against experimental data and provides a good starting point for plasma flow actuator studies. All important positive and negative ions, radicals, and electrons are included with a finite-rate air chemistry mechanism. Results of model and comparison with experimental data are presented. Characteristics of the air glow discharge in the abnormal and normal glow discharge regime are represented well by the model. Voltage-current characteristics and charged species density profiles in the discharge are compared directly with experimental results and are shown to be in reasonably good agreement.

Mahadevan, Shankar; Raja, Laxminarayan

2007-10-01

28

Infrared spectral measurement of space shuttle glow  

Microsoft Academic Search

Infrared spectral measurements of the space shuttle glow were successfully conducted during the STS-39 space shuttle mission. Analysis indicates that NO, NO[sup +], OH, and CO are among the molecules associated with the infrared glow phenomenon. During orbiter thruster firings the glow intensities in the infrared are enhanced by factors of 10x to 100x with significant changes in spectral distribution.

Ahmadijian

1992-01-01

29

Abnormal Brain Activation in Neurofibromatosis Type 1: A Link between Visual Processing and the Default Mode Network  

PubMed Central

Neurofibromatosis type 1 (NF1) is one of the most common single gene disorders affecting the human nervous system with a high incidence of cognitive deficits, particularly visuospatial. Nevertheless, neurophysiological alterations in low-level visual processing that could be relevant to explain the cognitive phenotype are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to study early cortical visual pathways in children and adults with NF1. We employed two distinct stimulus types differing in contrast and spatial and temporal frequencies to evoke relatively different activation of the magnocellular (M) and parvocellular (P) pathways. Hemodynamic responses were investigated in retinotopically-defined regions V1, V2 and V3 and then over the acquired cortical volume. Relative to matched control subjects, patients with NF1 showed deficient activation of the low-level visual cortex to both stimulus types. Importantly, this finding was observed for children and adults with NF1, indicating that low-level visual processing deficits do not ameliorate with age. Moreover, only during M-biased stimulation patients with NF1 failed to deactivate or even activated anterior and posterior midline regions of the default mode network. The observation that the magnocellular visual pathway is impaired in NF1 in early visual processing and is specifically associated with a deficient deactivation of the default mode network may provide a neural explanation for high-order cognitive deficits present in NF1, particularly visuospatial and attentional. A link between magnocellular and default mode network processing may generalize to neuropsychiatric disorders where such deficits have been separately identified. PMID:22723888

Violante, Ines R.; Ribeiro, Maria J.; Cunha, Gil; Bernardino, Ines; Duarte, Joao V.; Ramos, Fabiana; Saraiva, Jorge; Silva, Eduardo; Castelo-Branco, Miguel

2012-01-01

30

Excessive hydrogen and deuterium Balmer lines broadening in a hollow cathode glow discharges  

Microsoft Academic Search

.  Results of a Doppler spectroscopy study of hydrogen and deuterium \\u000aBalmer lines in the stainless steel and copper hollow cathode glow \\u000adischarge, operated in pure hydrogen, deuterium and mixtures of inert gases \\u000awith hydrogen, are reported. For all gases and gas mixtures plasma \\u000aobservations perpendicular to electric field revealed the excessively large \\u000aDoppler broadening. By changing mode of glow discharge

N. M. Šišovi?; G. Lj. Majstorovi?; N. Konjevi?

2005-01-01

31

Second Workshop on Spacecraft Glow  

NASA Technical Reports Server (NTRS)

Various aspects of space glow were considered. Results of a workshop held on May 6 to 7, 1985, at the Space Science Laboratory of NASA/Marshall Space Flight Center, Huntsville, Alabama are presented. The topics of discussion are divided as follows: (1) in situ observations; (2) theoretical calculations; (3) laboratory measurements; and (4) future experiments.

Waite, J. H., Jr. (editor); Moorehead, T. W. (editor)

1985-01-01

32

Spectral characteristics of Shuttle glow  

NASA Technical Reports Server (NTRS)

The glowing cloud near the ram surfaces of the Space Shuttle was observed with a hand-held, intensified spectrograph operated by the astronauts from the aft-flight-deck of the Space Shuttle. The spectral measurements were made between 400 and 800 nm with a resolution of 3 nm. Analysis of the spectral response of the instrument and the transmission of the Shuttle window was performed on orbit using earth-airglow OH Meinel bands. This analysis resulted in a correction of the Shuttle glow intensity in the spectral region between 700 and 800 nm. The data presented in this report is in better agreement with laboratory measurements of the NO2 continuum.

Viereck, R. A.; Mende, S. B.; Murad, E.; Swenson, G. R.; Pike, C. P.; Culbertson, F. L.; Springer, R. C.

1992-01-01

33

Constricted glow discharge plasma source  

DOEpatents

A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.

Anders, Andre (Albany, CA); Anders, Simone (Albany, CA); Dickinson, Michael (San Leandro, CA); Rubin, Michael (Berkeley, CA); Newman, Nathan (Winnetka, IL)

2000-01-01

34

Common Gamma-ray Glows above Thunderclouds  

NASA Astrophysics Data System (ADS)

Gamma-ray glows are continuous, long duration gamma- and x-ray emission seen coming from thunderclouds. The Airborne for Energetic Lightning Emissions (ADELE) observed 12 gamma-ray glows during its summer 2009 flight campaign over the areas of Colorado and Florida in the United States. For these glows we shall present their spectra, relationship to lightning activity and how their duration and size changes as a function of distance. Gamma-ray glows follow the relativistic runaway electron avalanche (RREA) spectrum and have been previously measured from the ground and inside the cloud. ADELE measured most glows as it flew above the screening layer of the cloud. During the brightest glow on August 21, 2009, we can show that we are flying directly into a downward facing relativistic runaway avalanche, indicative of flying between the upper positive and negative screening layer of the cloud. In order to explain the brightness of this glow, RREA with an electric field approaching the limit for relativistic feedback must be occurring. Using all 12 glows, we show that lightning activity diminishes during the onset of the glow. Using this along with the fact that glows occur as the field approaches the level necessary for feedback, we attempt to distinguish between two possibilities: that glows are evidence that RREA with feedback, rather than lightning, is sometimes the primary channel for discharging the cloud, or else that the overall discharging is still controlled by lightning, with glows simply appearing during times when a subsidence of lightning allows the field to rise above the threshold for RREA.

Kelley, Nicole; Smith, David; Dwyer, Joseph; Hazelton, Bryna; Grefenstette, Brian; Lowell, Alex; Splitt, Michael; Lazarus, Steven; Rassoul, Hamid

2013-04-01

35

Spacecraft ram glow and surface temperature  

NASA Technical Reports Server (NTRS)

Space shuttle glow intensity measurements show large differences when the data from different missions are compared. In particular, on the 41-G mission the space shuttle ram glow was observed to display an unusually low intensity. Subsequent investigation of this measurement and earlier measurements suggest that there was a significant difference in temperature of the glow producing ram surfaces. The highly insulating properties coupled with the high emissivity of the shuttle tile results in surfaces that cool quickly when exposed to deep space on the night side of the orbit. The increased glow intensity is consistent with the hypothesis that the glow is emitted from excited NO2. The excited NO2 is likely formed through three body recombination (OI + NO + M = NO2*) where ramming of OI interacts with weakly surface bound NO. The NO is formed from atmospheric OI and NI which is scavenged by the spacecraft moving through the atmosphere. It is postulated that the colder surfaces retain a thicker layer of NO thereby increasing the probability of the reaction. It has been found from the glow intensity/temperature data that the bond energy of the surface bound precursor, leading to the chemical recombination producing the glow, is approximately 0.14 eV. A thermal analysis of material samples of STS-8 was made and the postulated temperature change of individual material samples prior to the time of glow measurements above respective samples are consistent with the thermal effect on glow found for the orbiter surface.

Swenson, G. R.; Mende, S. B.; Llewellyn, E. J.

1987-01-01

36

Glow Sticks: Spectra and Color Mixing  

NASA Astrophysics Data System (ADS)

Glow sticks are a popular Halloween staple familiar to most of our students. The production of light via a chemical reaction is called "chemiluminescence," and glow sticks are often used as demonstrations and experiments in the chemistry classroom to study reaction rates as a function of temperature.1-3 A black light can be used to illuminate glow sticks that have not been cracked or those that are "dead" in order to demonstrate fluorescence in liquid chemicals.4 In this article, we present the use of glow sticks as an inexpensive demonstration of spectra and color addition.

Birriel, Jennifer; Birriel, Ignacio

2014-10-01

37

Gas flow effects on the submicrosecond pulsed atmospheric pressure glow discharges  

SciTech Connect

The influence of gas flow on the discharge characteristics in the submicrosecond pulsed dielectric barrier discharge at atmospheric pressure was investigated by a one-dimensional self-consistent kinetic model. The convection-transport mechanism of the plasma species caused by a longitudinal gas flow was integrated into flux equation. Two discharge current pulses, the positive one and the negative one, are operated in a normal glow mode and a subnormal glow mode, respectively. It is shown that the gas flow has a significant impact on the discharge characteristics, especially on the positive discharge pulse. The spatial distribution of electrons is affected by the gas flow through the convection transport mechanism.

Liu Fucheng; Zhang Dingzong; Wang Dezhen [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2010-10-15

38

APEX reveals glowing stellar nurseries  

NASA Astrophysics Data System (ADS)

Illustrating the power of submillimetre-wavelength astronomy, an APEX image reveals how an expanding bubble of ionised gas about ten light-years across is causing the surrounding material to collapse into dense clumps that are the birthplaces of new stars. Submillimetre light is the key to revealing some of the coldest material in the Universe, such as these cold, dense clouds. Glowing Stellar Nurseries ESO PR Photo 40/08 Glowing Stellar Nurseries The region, called RCW120, is about 4200 light years from Earth, towards the constellation of Scorpius. A hot, massive star in its centre is emitting huge amounts of ultraviolet radiation, which ionises the surrounding gas, stripping the electrons from hydrogen atoms and producing the characteristic red glow of so-called H-alpha emission. As this ionised region expands into space, the associated shock wave sweeps up a layer of the surrounding cold interstellar gas and cosmic dust. This layer becomes unstable and collapses under its own gravity into dense clumps, forming cold, dense clouds of hydrogen where new stars are born. However, as the clouds are still very cold, with temperatures of around -250? Celsius, their faint heat glow can only be seen at submillimetre wavelengths. Submillimetre light is therefore vital in studying the earliest stages of the birth and life of stars. The submillimetre-wavelength data were taken with the LABOCA camera on the 12-m Atacama Pathfinder Experiment (APEX) telescope, located on the 5000 m high plateau of Chajnantor in the Chilean Atacama desert. Thanks to LABOCA's high sensitivity, astronomers were able to detect clumps of cold gas four times fainter than previously possible. Since the brightness of the clumps is a measure of their mass, this also means that astronomers can now study the formation of less massive stars than they could before. The plateau of Chajnantor is also where ESO, together with international partners, is building a next generation submillimetre telescope, ALMA, the Atacama Large Millimeter/submillimeter Array. ALMA will use over sixty 12-m antennas, linked together over distances of more than 16 km, to form a single, giant telescope. APEX is a collaboration between the Max-Planck-Institute for Radio Astronomy (MPIfR), the Onsala Space Observatory (OSO) and ESO. The telescope is based on a prototype antenna constructed for the ALMA project. Operation of APEX at Chajnantor is entrusted to ESO.

2008-11-01

39

Atmospheric sampling glow discharge ionization source  

DOEpatents

An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above.

McLuckey, Scott A. (Oak Ridge, TN); Glish, Gary L. (Oak Ridge, TN)

1989-01-01

40

Atmospheric sampling glow discharge ionization source  

DOEpatents

An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.

McLuckey, S.A.; Glish, G.L.

1989-07-18

41

Glow Plasma Discharges inside Externally Excited Porous Spherical Cavity Resonators  

NASA Astrophysics Data System (ADS)

A porous spherical cavity resonator (PSCR) provides amplification of externally incident electric fields a resonant frequencies corresponding to discrete modes. The PSCR has a mesh surface with a large number of polygon (hexagon and pentagon) holes. The size of the holes is adjusted to maximize the Q of the resonator for production of maximum internal electrical fields. Amplification factors for a PSCR are about 1000. The high resonator Q requires precise tuning of the incident wave frequency to a resonant frequency. The PSCR is placed in a low-pressure (1 T) gas chamber and excited by an external microwave horn for a chosen spherical cavity resonator mode. At the resonant frequency, a glow discharge occurs inside the cavity producing a plasma cloud in the shape of electric field modes. Varying the neutral gas pressure inside the chamber (1) yields variations in the glow discharge light intensity and (2) affects the shapes of the plasma cloud. If the plasma frequency in the electron cloud approaches the incident wave frequency, self-action produces localized regions of dense plasmas. The PSCR apparatus can be used to study cavity resonator modes in the low pressure environment and electromagnetic wave interactions in high pressure plasmas.

Bernhardt, Paul; Fliflet, Arne

2012-10-01

42

Meiotic abnormalities  

SciTech Connect

Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

NONE

1993-12-31

43

Probiotic Bacteria Induce a ‘Glow of Health’  

E-print Network

Radiant skin and hair are universally recognized as indications of good health. However, this ‘glow of health’ display remains poorly understood. We found that feeding of probiotic bacteria to aged mice induced integumentary ...

Levkovich, Tatiana

44

Auroral glow equatorward from the auroral oval  

NASA Astrophysics Data System (ADS)

On the basis of observations for the IGY period (visoplots) it is shown, that during magnetic storms diffuse glow is detected at all latitudes between the lowest latitude of the visually observed auroral glow at the zenith and the auroral oval. The diffuse glow region spatially coincides with the region of soft electron precipitation extending equatorward from the boundary of the oval to the latitude of the plasmopause projections along the magnetic force lines to the ionosphere. Using published materials on the diffuse glow dynamics and SAR arcs at the Yakutsk meridian, as well as simultaneous measurements of the DMSP F9 satellite, we discuss the contribution from low-energy electron precipitation transfered via convection toward Earth from the magnetosphere's plasma sheet to excitation of 630.0 nm emission in low-intensity (<1.0 kR) SAR arcs.

Zverev, V. L.; Feldstein, Ya. I.; Vorobjev, V. G.

2012-02-01

45

Infrared spectral measurement of space shuttle glow  

SciTech Connect

Infrared spectral measurements of the space shuttle glow were successfully conducted during the STS-39 space shuttle mission. Analysis indicates that NO, NO[sup +], OH, and CO are among the molecules associated with the infrared glow phenomenon. During orbiter thruster firings the glow intensities in the infrared are enhanced by factors of 10x to 100x with significant changes in spectral distribution. These measurements were obtained with the Spacecraft Kinetic Infrared Test (SKIRT) payload which included a cryogenic infrared circular variable filter (CVF) spectrometer (0.6 [mu]m to 5.4 [mu]) and a number of infrared, visible, and ultraviolet radiometers (0.2 [mu]m to 5.4 [mu]m and 9.9 [mu]m to 10.4 [mu]m). In addition, glow measurements were unsuccessfully attempted with the Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS-1A) with its 2.5 [mu]m to 25 [mu]m Fourier transform interferometer. SKIRT CVF obtained over 14,000 spectra of quiescent shuttle glow, thruster enhanced shuttle glow, upper atmosphere airglow, aurora, orbiter environment, and deep space non-glow backgrounds during its eight day mission. The SKIRT radiometers operated almost continuously throughout the mission to provide a detailed history of the IR/VIS/UV optical environment associated with the operation of large spacecraft structures in low earth orbit. This dissertation will primarily address those measurements conducted by the SKIRT spectrometer as they relate to space shuttle glow in the infrared. The STS-39 Space Shuttle Discovery was launched from the NASA Kennedy Space Center on 28 April 1991 into a 57 degree inclination circular orbit at an altitude of 260 km.

Ahmadijian, M.

1992-01-01

46

Discharge characteristics of atmospheric-pressure radio-frequency glow discharges with argon/nitrogen  

SciTech Connect

In this letter, atmospheric-pressure glow discharges in {gamma} mode with argon/nitrogen as the plasma-forming gas using water-cooled, bare copper electrodes driven by radio-frequency power supply at 13.56 MHz are achieved. The preliminary studies on the discharge characteristics show that, induced by the {alpha}-{gamma} coexisting mode or {gamma} mode discharge of argon, argon-nitrogen mixture with any mixing ratios, even pure nitrogen, can be employed to generate the stable {gamma} mode radio-frequency, atmospheric-pressure glow discharges and the discharge voltage rises with increasing the fraction of nitrogen in the argon-nitrogen mixture for a constant total gas flow rate.

Wang Huabo; Sun Wenting; Li Heping; Bao Chengyu; Gao Xing; Luo Huiying [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); School of Public Health and Family Medicine, Capital University of Medical Sciences, Beijing 100069 (China); Beijing Center for Diseases Control and Prevention, Beijing 100013 (China)

2006-10-16

47

Chromosomal abnormalities  

SciTech Connect

Cytogenetic studies from the peripheral blood of a patient with malignant lymphoma and rhematoid arthritis who was treated with intra-articular gold Au 198 revealed mosaicism with a normal female metaphase and a 43-chromosome metaphase. The abnormal cell line showed six missing normal chromosomes and three morphologically abnormal chromosomes. The trypsin-digested G-banding metaphases showed that the marker chromosomes were an isochromosome of the long arm of chromosome 17, a translocated chromosome that involved the long arm of chromosome 4 and a chromosome 16, and a translocated chromosome that involved the long arm of chromosome 4 and a chromosome 5. It is tempting to conclude that these abnormalities were due to the gold Au 198 treatment, but we cannot exclude other possibilities.

Goh, K.; Jacox, R.F.; Anderson, F.W.

1980-09-01

48

Mass dependency of turbulent parameters in stationary glow discharge plasmas  

SciTech Connect

A direct current glow discharge tube is used to determine how mass changes the effects of certain turbulence characteristics in a weakly ionized gas. Helium, neon, argon, and krypton plasmas were created, and an axial magnetic field, varied from 0.0 to 550.0 Gauss, was used to enhance mass dependent properties of turbulence. From the power spectra of light emission variations associated with velocity fluctuations, determination of mass dependency on turbulent characteristic unstable modes, energy associated with turbulence, and the rate at which energy is transferred from scale to scale are measured. The magnetic field strength is found to be too weak to overcome particle diffusion to the walls to affect the turbulence in all four types of plasmas, though mass dependency is still detected. Though the total energy and the rate at which the energy moves between scales are mass invariant, the amplitude of the instability modes that characterize each plasma are dependent on mass.

Titus, J. B.; Alexander, A. B. [Florida A and M University, Tallahassee, Florida 32310 (United States)] [Florida A and M University, Tallahassee, Florida 32310 (United States); Wiggins, D. L. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53703 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53703 (United States); Johnson, J. A. III [Pyramid Plasmas LLC, Lawrenceville, Georgia 30043 (United States)] [Pyramid Plasmas LLC, Lawrenceville, Georgia 30043 (United States)

2013-05-15

49

Mass dependency of turbulent parameters in stationary glow discharge plasmas  

NASA Astrophysics Data System (ADS)

A direct current glow discharge tube is used to determine how mass changes the effects of certain turbulence characteristics in a weakly ionized gas. Helium, neon, argon, and krypton plasmas were created, and an axial magnetic field, varied from 0.0 to 550.0 Gauss, was used to enhance mass dependent properties of turbulence. From the power spectra of light emission variations associated with velocity fluctuations, determination of mass dependency on turbulent characteristic unstable modes, energy associated with turbulence, and the rate at which energy is transferred from scale to scale are measured. The magnetic field strength is found to be too weak to overcome particle diffusion to the walls to affect the turbulence in all four types of plasmas, though mass dependency is still detected. Though the total energy and the rate at which the energy moves between scales are mass invariant, the amplitude of the instability modes that characterize each plasma are dependent on mass.

Titus, J. B.; Wiggins, D. L.; Alexander, A. B.; Johnson, J. A.

2013-05-01

50

Io Glowing in the Dark  

NASA Technical Reports Server (NTRS)

Volcanic hot spots and auroral emissions glow on the darkside of Jupiter's moon Io in the image at left. The image was taken by the camera onboard NASA's Galileo spacecraft on 29 June, 1996 UT while Io was in Jupiter's shadow. It is the best and highest-resolution image ever acquired of hot spots or auroral features on Io. The mosaic at right of 1979 Voyager images is shown with an identical scale and projection to identify the locations of the hot spots seen in the Galileo image. The grid marks are at 30 degree intervals of latitude and longitude. North is to the top.

In the nighttime Galileo image, small red ovals and perhaps some small green areas are from volcanic hot spots with temperatures of more than about 700 kelvin (about 1000 degrees Fahrenheit). Greenish areas seen near the limb, or edge of the moon, are probably the result of auroral or airglow emissions of neutral oxygen or sulfur atoms in volcanic plumes and in Io's patchy atmosphere. The image was taken from a range of 1,035,000 kilometers (about 643,000 miles).

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

1996-01-01

51

Suppression of the Glow-to-Arc Transition in Glow Discharges  

NASA Astrophysics Data System (ADS)

The operating regime of stble glow discharges is limited by instabilities, in particular by the well-known glow-to-arc-transition (GAT). The GAT arises in the cathode fall region of the glow discharge where the electric field is very high and causes a transition from a diffuse uniform glow and to a filamentary, high current arc discharge. While there have been previous efforts to stabilize glow discharges (see e.g. Akishev et al., Proc. XX. ICPIG, Bochum, 1991) even at atmospheric pressures, the proposed concepts tend to be energy inefficient, cumbersome to implement, and lend themselves only to the generation of very small stable glow discharge volumes. We introduce a novel cathode design (patent pending) which allows us to generate and maintain stable, uniform glow discharges at pressures up to atmospheric pressure. The novel cathode design facilitates stabilization by actively limiting the current density in the cathode fall. Full details of the novel concept and experimental results will be presented and discussed at the Conference.

Kunhardt, E. E.; Becker, K.; Armorer, L.; Palatini, L.

1997-10-01

52

A high resolution ultraviolet Shuttle glow spectrograph  

NASA Technical Reports Server (NTRS)

The High Resolution Shuttle Glow Spectrograph-B (HRSGS-B) is a small payload being developed by the Naval Research Laboratory. It is intended for study of shuttle surface glow in the 180-400 nm near- and middle-ultraviolet wavelength range, with a spectral resolution of 0.2 nm. It will search for, among other possible features, the band systems of excited NO which result from surface-catalyzed combination of N and O. It may also detect O2 Hertzberg bands and N2 Vegard-Kaplan bands resulting from surface recombination. This wavelength range also includes possible N2+ and OH emissions. The HRSGS-B will be housed in a Get Away Special canister, mounted in the shuttle orbiter payload bay, and will observe the glow on the tail of the orbiter.

Carruthers, George R.

1993-01-01

53

Normal glow discharge in axial magnetic field  

NASA Astrophysics Data System (ADS)

Theory and results of mathematical modeling of a glow discharge in a parallel-plate configuration with axial magnetic field is presented. The model consists of continuity equations for electron and ion fluids, the Poisson equation for the self-consistent electric field. Numerical simulation results are presented for two-dimensional glow discharge at various initial conditions. The results are obtained for molecular nitrogen at pressure 1–5 Torr, emf of power supply 1–2 kV, and magnetic field induction B = 0–0.5 T. It is shown that in the presence of the axial magnetic field the glow discharge is rotated around its axis of symmetry. Nevertheless it is shown that in the investigated range of discharge parameters in an axial magnetic field the law of the normal current density is retained.

Surzhikov, S.; Shang, J.

2014-10-01

54

The glow discharge as an atomization and ionization device  

SciTech Connect

All of our projects involve the glow discharge source as our basic research focus. Our primary effort is glow discharge mass spectrometry, but we frequently use complementary procedures such as atomic absorption and atomic emission in the glow discharge to obtain useful information about plasma processes. Our overall goal is to gain a better understanding of the glow discharge and to bring it to bear on real analytical problems.

Harrison, W.W.

1990-01-01

55

Application Feasibility of Detecting Glowing Contacts Using Acoustic Sensing Technology  

Microsoft Academic Search

Glowing contacts may be precursors to arc faults and could lead to fire hazards even before arc faults occur. As of today there is no cost effective technology available to detect overheated or glowing contacts. Experiments have been conducted in order to investigate both the acoustic characteristics associated with glowing contacts and the feasibility of their detection under various conditions

Xin Zhou; Jerome Hastings; Thomas J. Schoepf

2009-01-01

56

Evaluation of Thermal Activation Energies from Glow Curves  

Microsoft Academic Search

A new method for the evaluation of thermal activation energies from glow curves of excited crystals is described. Use is made of the symmetry of the glow peak, from which the activation energy is calculated by a simple formula: E=(qdelta)kTg2, where Tg is the peak temperature, k-Boltzmann's constant, delta-the half-width towards the falloff of the glow peak, and q-a factor

A. Halperin; A. A. Braner

1960-01-01

57

Protein destruction by atmospheric pressure glow discharges  

SciTech Connect

It is well established that atmospheric pressure glow discharges are capable of bacterial inactivation. Much less known is their ability to destruct infectious proteins, even though surgical instruments are often contaminated by both bacteria and proteinaceous matters. In this letter, the authors present a study of protein destruction using a low-temperature atmospheric dielectric-barrier discharge jet. Clear evidences of protein removal are presented with data of several complimentary experiments using scanning electron microscopy, electron dispersive x-ray analysis, electrophoresis, laser-induced fluorescence microscopy, and protein reduction kinetics. Considerable degradation is observed of protein fragments that remain on their substrate surface after plasma treatment.

Deng, X. T.; Shi, J. J.; Chen, H. L.; Kong, M. G. [Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); MRC Toxicology Unit, University of Leicester, Leicester, Leicestershire LE1 9HN (United Kingdom); Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)

2007-01-01

58

Dust Waves Excited in a DC Glow Discharge Plasma  

Microsoft Academic Search

We present a review of experimental studies to excite nonlinear dust waves in a dc glow discharge plasma. The experiments were performed in a vertically positioned glass tube filled with neon and the stratified glow discharge with cold electrodes was created inside it. Dust particles were injected into a plasma and formed ordered structures in the striations. The dust grains

V. M. Torchinsky; V. N. Naumkin; V. I. Molotkov; V. E. Fortov; O. F. Petrov; A. G. Khrapak; M. Y. Poustylnik

2005-01-01

59

Space shuttle Ram glow: Implication of NO2 recombination continuum  

Microsoft Academic Search

The ram glow data gathered to data from imaging experiments on space shuttle suggest the glow is a continuum (within 34 angstrom resolution); the continuum shape is such that the peak is near 7000 angstroms decreasing to the blue and red, and the average molecular travel leading to emission after leaving the surface is 20 cm (assuming isotropic scattering from

G. R. Swenson; S. B. Mende; S. Clifton

1985-01-01

60

Glow discharge based device for solving mazes  

NASA Astrophysics Data System (ADS)

A glow discharge based device for solving mazes has been designed and tested. The device consists of a gas discharge chamber and maze-transformer of radial-azimuth type. It allows changing of the maze pattern in a short period of time (within several minutes). The device has been tested with low pressure air. Once switched on, a glow discharge has been shown to find the shortest way through the maze from the very first attempt, even if there is a section with potential barrier for electrons on the way. It has been found that ionization waves (striations) can be excited in the maze along the length of the plasma channel. The dependancy of discharge voltage on the length of the optimal path through the maze has been measured. A reduction in discharge voltage with one or two potential barriers present has been found and explained. The dependency of the magnitude of discharge ignition voltage on the length of the optimal path through the maze has been measured. The reduction of the ignition voltage with the presence of one or two potential barriers has been observed and explained.

Dubinov, Alexander E.; Maksimov, Artem N.; Mironenko, Maxim S.; Pylayev, Nikolay A.; Selemir, Victor D.

2014-09-01

61

Spherical stratification of a glow discharge  

NASA Astrophysics Data System (ADS)

Spherically symmetrical strata (striation) in a dc glow discharge were discovered. Experiments were carried out in a low-pressure steel chamber that served as a cathode. An anode was placed in the center of the chamber. The stratification of the glow discharge was observed in some molecular gases: air, N2, O2, CO2, and acetone vapor. A simple relation between strata radii and their number rn/rn-1=?, where ?=1.4-2 (depending on gas composition), were found. Gas pressure dependences of strata radii were measured. The values of bulk charge and electric potential radial distributions were estimated. A simplified Boltzmann equation for the electron energy distribution function (EEDF) in spherical geometry was used for theoretical consideration. The so-called ``black wall law'' assumption was used in the collisional integral. An analytical solution for the isotropic part of EEDF was obtained. The existence of converging and decaying stagnant waves reproducing the variation of the observed strata radii was shown.

Nerushev, O. A.; Novopashin, S. A.; Radchenko, V. V.; Sukhinin, G. I.

1998-10-01

62

GLOW- The Goddard Lidar Observatory for Winds  

NASA Technical Reports Server (NTRS)

GLOW (Goddard Lidar Observatory for Winds) is a mobile Doppler lidar system which uses direct detection Doppler lidar techniques to measure wind profiles from the surface into the lower stratosphere. The system is contained in a modified van to allow deployment in field operations. The lidar system uses a Nd:YAG laser transmitter to measure winds using either aerosol backscatter at 1064 nm or molecular backscatter at 355 nm. The receiver telescope is a 45 cm Dall-Kirkham which is fiber coupled to separate Doppler receivers, one optimized for the aerosol backscatter wind measurement and another optimized for the molecular backscatter wind measurement. The receivers are implementations of the 'double edge' technique and use high spectral resolution Fabry-Perot etalons to measure the Doppler shift. A 45 cm aperture azimuth-over-elevation scanner is mounted on the roof of the van to allow full sky access and a variety of scanning options. GLOW is intended to be used as a deployable field system for studying atmospheric dynamics and transport and can also serve as a testbed to evaluate candidate technologies developed for use in future spaceborne systems. In addition, it can be used for calibration/validation activities following launch of spaceborne wind lidar systems. A description of the mobile system is presented along with the examples of lidar wind profiles obtained with the system.

Gentry, Bruce M.; Chen, Huailin; Li, Steven X.

2000-01-01

63

GLOW: The Goddard Lidar Observatory for Winds  

NASA Technical Reports Server (NTRS)

GLOW (Goddard Lidar Observatory for Winds) is a mobile Doppler lidar system which uses direct detection Doppler lidar techniques to measure wind profiles from the surface into the lower stratosphere. The system is contained in a modified van to allow deployment in field operations. The lidar system uses a Nd:YAG laser transmitter to measure winds using either aerosol backscatter at 1064 nm or molecular backscatter at 355 nm. The receiver telescope is a 45 cm Dall-Kirkham which is fiber coupled to separate Doppler receivers, one optimized for the aerosol backscatter wind measurement and another optimized for the molecular backscatter wind measurement. The receivers are implementations of the 'double edge' technique and use high spectral resolution Fabry-Perot etalons to measure the Doppler shift. A 45 cm aperture azimuth-over-elevation scanner is mounted on the roof of the van to allow full sky access and a variety of scanning options. GLOW is intended to be used as a deployable field system for studying atmospheric dynamics and transport and can also serve as a testbed to evaluate candidate technologies developed for use in future spaceborne systems. In addition, it can be used for calibration/validation activities following launch of spaceborne wind lidar systems. A description of the mobile system is presented along with the examples of lidar wind profiles obtained with the system.

Gentry, Bruce M.; Chen, Huailin; Li, Steven X.; Einaudi, Franco (Technical Monitor)

2000-01-01

64

Optical bleaching and radiation response of feldspar TL glow peaks separated by using computerized glow curve deconvolution  

NASA Astrophysics Data System (ADS)

The thermoluminescence (TL) peaks of feldspar were separated using the computerized glow curve deconvolution (CGCD) method combined with the second-derivative technique and were investigated not only for bleaching with different light sources (blue and infrared) but also for luminescence response to radiation dose. In the results, the TL glow peak was separated into four peaks at 280 °C, 315 °C, 360 °C, and 440 °C. Each separated TL glow peak exhibited two exponential decays in the signal bleached using blue or infrared stimulation. In view of all four separated glow peaks, the bleaching of the first (second) exponential component was faster (slower) for both the blue and the infrared stimulation as the peak temperature increased, and the bleaching of the first (second) exponential component with blue stimulation was faster (slower) than that with infrared stimulation. In addition, we found that with added beta dose, the shapes of the growth curves showed no substantial differences for the separated glow peaks.

Kim, Ki-Bum; Hong, Duk-Geun

2012-08-01

65

Mode transition and nonlinear self-oscillations in the beam-driven collisional discharge plasma  

E-print Network

different modes, anode-glow, temperature-limited, and double-layer modes, are observed in the system-oscillation in the double layer mode is examined along with period-doubling and chaotic oscillations. © 1998 American gas pressure, the double-layer mode DLM appears. In this mode, the elastic collision be- tween

Lee, Hae June

66

Particle beam glow discharge mass spectrometry: spectral characteristics of nucleobases.  

PubMed

Use of a particle beam glow discharge (PB-GD) source for mass spectrometric determinations of deoxy- and ribonucleosides and nucleotides is described. Use of this combination of sample introduction and ion source decouples the vaporization and ionization steps, leading to very simple spectral structure. The mass spectra of these compounds are EI-like in nature, with clearly identified molecular ions and fragmentation patterns that are easily rationalized. The PB-GDMS combination can be operated in a flow injection mode wherein the analyte is injected directly into the solvent flow, or can also be coupled to a high-performance liquid chromatography (HPLC) system allowing LC/MS analysis of mixtures. Mass spectra obtained for nucleic acid bases, nucleosides, and nucleotides are readily obtained with injections of low-nanomole quantities. Representative PB-GDMS spectra for deoxy- and ribonucleosides, nucleotides, and mixed-base oligonucleotides are presented to demonstrate the capabilities of the GD source. Characteristic fragmentation peaks from the spectra of adenine, cytosine, guanine, and thymine were identified in 22-base sequences of single-stranded DNA. The PB-GD source is capable of producing spectra that may be used to identify the individual bases present in mixed-base DNA and RNA fragments. PMID:12872280

Davis, W Clay; Venzie, Jacob L; Willis, Bert; Coffee, R Lane; Arya, Dev P; Marcus, R Kenneth

2003-01-01

67

Journal of Abnormal Psychology  

Microsoft Academic Search

This article is reprinted from the Journal of Abnormal Psychology, 1965, 70, 1. The Journal of Abnormal Psychology will give priority to articles on problems related to abnormal behavior, broadly defined. The Journal's interests thus include the following: (a) psychopathology--its development or acquisition, its treatment or remission, and its symptomatology and course; (b) normal processes in abnormal individuals; (c) pathological

Howard F. Hunt; William N. Thetford

1965-01-01

68

Probiotic bacteria induce a 'glow of health'.  

PubMed

Radiant skin and hair are universally recognized as indications of good health. However, this 'glow of health' display remains poorly understood. We found that feeding of probiotic bacteria to aged mice induced integumentary changes mimicking peak health and reproductive fitness characteristic of much younger animals. Eating probiotic yogurt triggered epithelial follicular anagen-phase shift with sebocytogenesis resulting in thick lustrous fur due to a bacteria-triggered interleukin-10-dependent mechanism. Aged male animals eating probiotics exhibited increased subcuticular folliculogenesis, when compared with matched controls, yielding luxuriant fur only in probiotic-fed subjects. Female animals displayed probiotic-induced hyperacidity coinciding with shinier hair, a feature that also aligns with fertility in human females. Together these data provide insights into mammalian evolution and novel strategies for integumentary health. PMID:23342023

Levkovich, Tatiana; Poutahidis, Theofilos; Smillie, Christopher; Varian, Bernard J; Ibrahim, Yassin M; Lakritz, Jessica R; Alm, Eric J; Erdman, Susan E

2013-01-01

69

Entrainment by Spatiotemporal Chaos in Glow Discharge-Semiconductor Systems  

E-print Network

Entrainment of limit cycles by chaos [1] is discovered numerically through specially designed unidirectional coupling of two glow discharge-semiconductor systems. By utilizing the auxiliary system approach [2], it is verified that the phenomenon is not a chaos synchronization. Simulations demonstrate various aspects of the chaos appearance in both drive and response systems. Chaotic control is through the external circuit equation and governs the electrical potential on the boundary. The expandability of the theory to collectives of glow discharge systems is discussed, and this increases the potential of applications of the results. Moreover, the research completes the previous discussion of the chaos appearance in a glow discharge-semiconductor system [3].

Marat Akhmet; Ismail Rafatov; Mehmet Onur Fen

2014-06-15

70

Glow discharge techniques for conditioning high vacuum systems  

SciTech Connect

A review is given of glow discharge techniques which are useful for conditioning vacuum vessels for high vacuum applications. Substantial development of glow discharge techniques has been done for the purpose of in-situ conditioning of the large ultrahigh vacuum systems for particle accelerators and magnetic fusion devices. In these applications the glow discharge treatments remove impurities from vessel surfaces in order to minimize particle-induced desorption coefficients. Cleaning mechanisms involve a mixture of sputtering and ion- (or neutral) induced desorption effects depending on the gas mixture (ArO/sub 2/ vs. H/sub 2/) and excitation method (DC, RF, and ECR). The author will review the methodology of glow discharge conditioning, diagnostic measurements provided by residual gas and surface composition analysis, and applications to vessel conditioning and materials processing. 76 refs., 16 figs.

Dylla, H.F.

1988-03-01

71

Ram vehicle glow spectrum - Implication of NO2 recombination continuum  

NASA Technical Reports Server (NTRS)

An experiment was operated on several Space Shuttle missions to provide spatial and spectral distributions of a ram glow associated with the Orbiter. The most recent data featured resolved spectrum and imagery of the glow with spectroscopic resolution of 34 A FWHM between 4000 and 8000 A. The spectrum of the glow on the Shuttle tail pod could be clearly separated from spectrum of the reflected light from the Orbiter. Analysis and comparison have been performed which strongly suggest the emission originates from recombination continuum of NO2. Both fast recombination (high temperature) and the spectral dependence in lifetime can describe the spectral difference. If the recombined NO2 retains 25 percent of the kinetic energy of the ram OI, the thickness of the glow layer can be explained by the lifetime of NO2 (2B1) recombination emission.

Swenson, G. R.; Mende, S. B.; Clifton, K. S.

1985-01-01

72

Vehicle/Atmosphere Interaction Glows: Far Ultraviolet, Visible, and Infrared  

NASA Technical Reports Server (NTRS)

Spacecraft glow information has been gathered from a number of spacecraft including Atmospheric and Dynamic satellites, and Space Shuttles (numerous flights) with dedicated pallet flow observations on STS-39 (DOD) and STS-62 (NASA). In addition, a larger number of laboratory experiments with low energy oxygen beam studies have made important contributions to glow understanding. The following report provides information on three engineering models developed for spacecraft glow including the far ultraviolet to ultraviolet (1400-4000 A), and infrared (0.9-40 microns) spectral regions. The models include effects resulting from atmospheric density/altitude, spacecraft temperature, spacecraft material, and ram angle. Glow brightness would be predicted as a function of distance from surfaces for all wavelengths.

Swenson, G.

1999-01-01

73

Investigation of Sheath Phenomena in Electronegative Glow Discharges.  

National Technical Information Service (NTIS)

Two different methods of analyzing the cathode fall region of low pressure glow discharge were developed and applied to three different electronegative gas mixtures. One method was based on a self-consistent numerical solution to Poisson's equation, the c...

G. L. Duke

1983-01-01

74

Investigation of Sheath Phenomena in Electronegative Glow Discharges.  

National Technical Information Service (NTIS)

Two different methods of analyzing the cathode fall region of low pressure glow discharges were developed and applied to three different electronegative gas mixtures. One method was based on a self-consistent numerical solution to Poisson's equation, the ...

G. L. Duke

1985-01-01

75

The measurements of vehicle glow on the Space Shuttle  

NASA Technical Reports Server (NTRS)

From the combined data set of glow observations on STS-3, STS-4 and STS-5 some of the properties of the shuttle glow were observed. Comparison of the STS-3 (240 km) and STS-5 (305 km) photographs show that the intensity of the glow is about a factor of 3.5 brighter on the low altitude (STS-3) flight. The orbiter was purposely rotated about the x axis in an experiment on STS-5 to observe the dependence of the intensity on the angle of incidence between the spacecraft surface normal and the velocity vector. For a relatively large angle between the velocity vector and the surface normal there is an appreciable glow, provided the surface is not shadowed by some other spacecraft structure. As the angle becomes less the glow intensifies. The grating experiments (STS-4 photography only, STS-5 image intensifier photography) provided a preliminary low resolution spectra of the spacecraft glow. Accurate wavelength calibrations of the STS-5 instrument permitted measuring of the spectrum and intensity of the Earth's airglow.

Mende, S. B.; Banks, P. M.; Nobles, R.; Garriott, O. K.; Hoffman, J.

1983-01-01

76

Skeletal limb abnormalities  

MedlinePLUS

Skeletal limb abnormalities may be due to: Cancer Genetic diseases and chromosomal abnormalities, including Marfan syndrome , Down syndrome, Apert syndrome , Basal cell nevus syndrome Improper position in the womb Infections during pregnancy ...

77

Congenital and Developmental Abnormalities  

Microsoft Academic Search

Congenital and developmental abnormalities influencing life are rare. They mainly consist of pectus deformities, sternal fusion\\u000a abnormalities and clavicular pseudoarthrosis. The most life-threatening abnormality is cleft sternum which may leave the heart\\u000a and great vessels unprotected.

Anne Grethe Jurik

78

Measuring Abnormal Bond Performance  

Microsoft Academic Search

We analyze the empirical power and specification of test statistics designed to detect abnormal bond returns in corporate event studies, using monthly and daily data. We find that test statistics based on frequently used methods of calculating abnormal monthly bond returns are biased. Most methods implemented in monthly data also lack power to detect abnormal returns. We also consider unique

Hendrik Bessembinder; Kathleen M. Kahle; William F. Maxwell; Danielle Xu

2009-01-01

79

Plasma sterilization using the RF glow discharge  

NASA Astrophysics Data System (ADS)

In the present work, glow discharge oxygen plasma was used to sterilize the Pseudomonas aeruginosa on the polyethylene terephthalate (PET) sheets. In a self-designed plasma reaction equipment, active species (electron, ion, radical, UV light, etc.) were separated effectively, and the discharge area, afterglow area and remote area were plotted out in the plasma field. Before and after plasma treatment the cell morphology was studied by scanning electron microscopy (SEM). The results showed that after treatment of 30 s the germicidal effect is 4.26, 3. 84, 2.61, respectively in the three areas on the following conditions: discharge power was 40 W and gas flux was 20 cm 3/min. SEM results revealed the cell morphology before and after plasma treatment. The walls or cell membrane cracking was testified by determining the content of protein using coomassie light blue technique. The results from electron spin resonance spectroscopy (ESR) and double Langmuir electron probe showed that electron, ion and oxygen free radical played important roles in sterilization in the discharge area, but only oxygen radicals acted to sterilize the bacteria in the afterglow area and the remote area.

Yang, Liqing; Chen, Jierong; Gao, Junling; Guo, Yafei

2009-08-01

80

Analysing bifurcations encountered in numerical modelling of current transfer to cathodes of dc glow and arc discharges  

NASA Astrophysics Data System (ADS)

Bifurcations and/or their consequences are frequently encountered in numerical modelling of current transfer to cathodes of gas discharges, also in apparently simple situations, and a failure to recognize and properly analyse a bifurcation may create difficulties in the modelling and hinder the understanding of numerical results and the underlying physics. This work is concerned with analysis of bifurcations that have been encountered in the modelling of steady-state current transfer to cathodes of glow and arc discharges. All basic types of steady-state bifurcations (fold, transcritical, pitchfork) have been identified and analysed. The analysis provides explanations to many results obtained in numerical modelling. In particular, it is shown that dramatic changes in patterns of current transfer to cathodes of both glow and arc discharges, described by numerical modelling, occur through perturbed transcritical bifurcations of first- and second-order contact. The analysis elucidates the reason why the mode of glow discharge associated with the falling section of the current-voltage characteristic in the solution of von Engel and Steenbeck seems not to appear in 2D numerical modelling and the subnormal and normal modes appear instead. A similar effect has been identified in numerical modelling of arc cathodes and explained.

Almeida, P. G. C.; Benilov, M. S.; Cunha, M. D.; Faria, M. J.

2009-10-01

81

Influence of cathode material on generation of energetic hydrogen atoms in a glow discharge  

SciTech Connect

In this paper influence of cathode material on formation of fast hydrogen atoms in an abnormal glow discharge is investigated using Balmer alpha emission spectroscopy. Energetic H atoms are generated in charge exchange reactions of hydrogen ions that are accelerated in the electric field, and also formed in the backscattering process at the cathode surface. Copper and graphite cathodes were used. Investigation was performed in two orthogonal directions of observation in pure hydrogen and argon-hydrogen mixture. The shapes of the profiles are examined together with the space intensity distribution of Balmer alpha line. Reduced atom reflection from graphite was manifested in the spectroscopic result, in accordance to the field acceleration model. The effect was evident only at high ion energies. This is explained by energy dependence of reflection coefficient for H atoms.

Cvetanovic, N. [Faculty of Transport and Traffic Engineering, University of Belgrade, Vojvode Stepe 305, Belgrade 11000 (Serbia); Obradovic, B. M.; Kuraica, M. M. [Faculty of Physics, University of Belgrade, P.O. Box 368, Belgrade 11000 (Serbia)

2011-01-01

82

Enhanced Glow Discharge Production of Oxygen  

NASA Technical Reports Server (NTRS)

Studies starting in late seventies have shown Mars atmosphere can be used as a feedstock for oxygen production using simple chemical processing systems during early phases of the Mars exploration program. This approach has been recognized as one of the most important in-situ resource utilization (ISRU) concepts for enabling future round trip Mars missions. It was determined a decade ago that separation of oxygen can be accomplished efficiently by permeation through a silver membrane at temperatures well below 1000 K. This process involves adsorption of atomic oxygen on the surface and its subsequent diffusion through a silver lattice via an oxygen concentration gradient. We have determined recently that glow discharge can be used to liberate atomic oxygen from Mars atmosphere and that the oxygen can be collected through a silver permeation membrane. Recently, we demonstrated a substantial increase in energy efficiency of the process by applying a radio frequency discharge in combination with a silver permeation membrane. The experiments were performed using pure carbon dioxide in the pressure range equal to Mars surface conditions. Energy efficiency was defined as the ratio of the energy required to dissociate a unit mass of oxygen from carbon dioxide to the (electrical) energy consumed by the overall system during the dissociation and collection process. The research effort, started at NASA Langley Research Center, continued with this project. Oxygen production apparatus, built and operated under the research grant NAG1-1140 was relocated to the Atomic Beams Laboratory at ODU in July 1996, being since then in fall operation.

Ash, Robert; Zhong, Shi

1998-01-01

83

Drift model of the cathode region of a glow discharge  

NASA Astrophysics Data System (ADS)

A one-dimensional drift model of the cathode region of a glow discharge with allowance for both electron-impact ionization and charged particle loss is proposed. An exact solution to the model equations is obtained for the case of similar power-law dependences of the ion and electron drift velocities on the electric field strength. It is shown that, even in the drift approximation, a relatively wide transition layer in which the ion-to-electron current ratio approaches a constant value typical of the positive column of a glow discharge should occur between the thin space-charge sheath and the quasineutral plasma, the voltage drop across the space-charge sheath being comparable to that across the transition layer. The calculated parameters of the normal and anomalous glow discharges are in good agreement with available experimental data.

Kozhevnikov, V. Yu.; Kozyrev, A. V.; Korolev, Yu. D.

2006-11-01

84

High-Energy Radiation from Thunderstorms with ADELE: TGFs, Steps, and Glows  

NASA Technical Reports Server (NTRS)

The biggest challenge in the study of high-energy processes in thunderstorms is getting a detector to the vicinity of the electrically active regions of a storm. The Airborne Detector for Energetic Lightning Emissions (ADELE) has been used to detect gamma rays from aircraft above storms and from a storm-chasing van on the ground. In August 2009, ADELE flew above Florida storms in a Gulfstream V jet, detecting the first terrestrial gamma-ray flash (TGF) seen from a plane and continuous glows of high-energy emission above thunderclouds. The presence of these glows suggests that a gradual process of relativistic runaway and feedback may help limit the total amount of charging in thunderstorms, in contrast to the traditional view that only lightning discharges compete with the charging process. The upper limits on TGF emission from intracloud and cloud-to-ground lightning from the ADELE flights demonstrated conclusively that a TGF of the sort seen from space is not associated with most lightning and not necessary to trigger it. In August 2010, observations from a van detected stepped-leader x-ray emission from at least four lightning strikes in ten days of operations. This mode of operation is therefore promising for future observations of the stepping process, although a more varied suite of instrumentation, in particular a flash-distance detector, would be useful. We will report on these results and on future possibilities for ADELE campaigns.

Smith, David M.; Kelley, Nicole; Martinez-McKinney, Forest; Zhang, Zi Yan; Hazelton, Bryna; Grefenstette, Brian; Splitt, Michael; Lazarus, Steven; Ulrich, William; Levine, Steven; Dwyer, Joseph; Schaal, Meagan; Saleh, Ziad; Cramer, Eric; Rassoul, Hamid; Cummer, Steven; Lu, Gaopeng; Shao, Xuan-Min; Ho, Cheng; Blakeslee, Richard

2011-01-01

85

Optimization of hollow cathode diameter for particle beam/hollow cathode glow discharge atomic emission spectrometry  

NASA Astrophysics Data System (ADS)

An evaluation of the effect of cathode diameter on analyte emission intensity for the particle beam/hollow cathode glow discharge atomic emission spectroscopy (PB-HC-AES) system is described. A high-efficiency thermoconcentric nebulizer is used to generate a fine aerosol of the aqueous solution flowing at rates of ˜1 ml/min. Desolvation and use of a momentum separator/particle beam interface serves to introduce analyte particles into a heated HC glow discharge source for subsequent vaporization, atomization and excitation. The effects of discharge gas (He) pressure and current on emission responses for sodium and copper are evaluated in flow injection mode using 200-?l injection volumes for a series of fixed-length (25 mm) cylindrical HC having inner diameters of 2, 3, 5 and 7 mm. Analytical response curves obtained with the 2-mm i.d. HC for sodium and copper yield detection limits of 0.6 and 1.3 ppb in elemental Na and Cu, respectively, with less than 10% relative standard deviation (R.S.D.) for triplicate injections over a concentration range of 0.5-20 ppm.

Dempster, Melissa A.; Marcus, R. Kenneth

2000-06-01

86

Chemiluminescence: Synthesis of Cyalume 3 Chemiluminescence: Synthesis of Cyalume and Making it Glow  

E-print Network

it Glow Intro Chemiluminescence is the process whereby light is produced by a chemical reaction Release and Glow Formation The chemistry that forms the color glow in a light stick is shown below. In this experiment we will make Cyalume, the chemical used in "light sticks." A light stick contains a solution

Jasperse, Craig P.

87

[Design and experiment of a needle-to-cylinder electrode structure realizing the negative DC glow discharge in ambient air].  

PubMed

A new needle-to-cylinder electrode structure was designed to realize the stable glow discharge in ambient air. The stainless steel needle tip with diameter 56.4 microm and the copper cylinder with diameter 4mm were chosen as the cathode and the anode respectively, which were kept parallel by accurate mechanical structure. In the condition that the distance between the needle and the cylinder is 2 mm, the ballasting resistor is 10 M(omega), the discharge resistor is 10 M(omega), the testing resistor is 1 k(omega), and the discharge voltage is -2 740 V, without air flow in ambient air and at room temperature, the stable glow discharge between the needle and the cylinder was realized. Three different discharge modes can be observed: corona discharge, glow discharge and spark, which were verified by the discharge waveform stored in the oscilloscope, and the discharge pictures were recorded by digital camera. The needle-to-cylinder electrode structure is easy to fabricate by the MEMS technology, which can be used as the ion source of the portable analyzing instruments. PMID:25269283

Li, Hua; Wei, Chang-Yan; Liu, Chun-Xia; Shen, Xian-Hao; Chen, Zhen-Cheng

2014-07-01

88

Effects of radiofrequency glow discharge on impression material surface wettability  

Microsoft Academic Search

Statement of problem. Argon radiofrequency glow discharge (RGD) may simultaneously sterilize and improve surface wettability of impression materials.Purpose. The purpose of this study was to define RGD technical parameters that influence the surface wettability of impression material (optimization phase). Definition of RGD was followed by an assessment of these optimized RGD parameters on the wettability of four impression materials either

Richard M. Hesby; Chris R. Haganman; Clark M. Stanford

1997-01-01

89

First Impressions in a Glowing Host-Microbe Partnership  

E-print Network

#12;First Impressions in a Glowing Host-Microbe Partnership Jennifer J. Wernegreen1,* 1Nicholas://dx.doi.org/10.1016/j.chom.2013.07.015 Despite the clear significance of beneficial animal-microbe associations & Microbe, Kremer et al. (2013) reveal that first contact within the squid-vibrio symbiosis triggers

McFall-Ngai, Margaret

90

SkyGlowNet as a Vehicle for STEM Education  

NASA Astrophysics Data System (ADS)

SkyGlowNet is an emerging network of internet-enabled sky brightness meters (iSBM) that continuously record and log sky brightness at the zenith of each network node site. Also logged are time and weather information. These data are polled at a user-defined frequency, typically about every 45 seconds. The data are uploaded to the SkyGlowNet website, initially to a proprietary area where the data for each institution are embargoed for one or two semesters as students conduct research projects with their data. When released from embargo, the data are moved to another area where they can be accessed by all SkyGlowNet participants. Some of the data are periodically released to a public area on the website. In this presentation we describe the data formats and provide examples of both data content and the structure of the website. Early data from two nodes in the SkyGlowNet have been characterized, both quantitatively and qualitatively, by undergraduate students at NCAT. A summary of their work is presented here. These analyses are of utility in helping those new to looking at these data to understand how to interpret them. In particular, we demonstrate differences between effects on light at night and sky brightness due to astronomical cycles, atmospheric phenomena, and artificial lighting. Quantitative characterization of the data includes statistical analyses of parsed segments of the temporal data stream. An attempt is made to relate statistical metrics to specific types of phenomena.

Flurchick, K. M.; Craine, E. R.; Culver, R. B.; Deal, S.; Foster, C.

2013-06-01

91

Glowing Bacteria! Purpose: To use your knowledge about  

E-print Network

transform E. coli cells to produce green fluorescent protein. Background: The gene encoding green (glow) and why? Materials: E. coli, pGLO plasmid, transformation solution, nutrient broth, inoculation traits of E. coli that were NOT changed by transformation. 6. If

Rose, Michael R.

92

Glow plug for diesel engines of motor vehicles  

Microsoft Academic Search

This patent describes a process for manufacturing an electric filament spiral for a glow plug, which spiral includes an initial length (Lâ) extending from a location at which a current feeder is to be connected and an end length (Lâ) remote from the location at which a current feeder is to be connected. The process is characterized by the following

Izzi

1987-01-01

93

Metal Mesh Smear Sampling for Glow Discharge Analytical Spectroscopy  

SciTech Connect

Metal mesh smear sampling is being developed and evaluated for use in a number of glow discharge and other optical and mass spectrometric techniques. Sensitive elemental and isotopic analyses thus will be coupled with a convenient sampling scheme similar to one that is common for radiological surveys.

Shaw, R.W.; Barshick, C.M.; Ramsey, J.M.; Smith, D.H.

2000-06-01

94

Comparative Spectroscopic Temperature Measurements In Hydrogen Hollow Cathode Glow Discharge  

Microsoft Academic Search

We report results of optical emission spectroscopy measurements of rotational Trot and translational temperature Ttr of hydrogen molecules. The light source was hollow cathode glow discharge with titanium cathode operated in hydrogen at low pressure. The rotational temperature of excited electronic states of H2 was determined either from relative line intensities of the R branch of the GK ? B

G. Lj. Majstorovic; N. M. Sisovic; N. Konjevic

2010-01-01

95

Laser-Excited Atomic Fluorescence in a Pulsed Glow Discharge.  

National Technical Information Service (NTIS)

A pulsed demountable glow discharge has been used as an atom cell for laser excited atomic fluorescence. Lead atoms are sputtered from the surface of copper and graphite cathodes and are excited by a pulsed frequency-doubled dye laser after the discharge ...

B. W. Smith, N. Omenetto, J. D. Winefordner

1984-01-01

96

Characteristics of atmospheric-pressure, radio-frequency glow discharges operated with argon added ethanol  

SciTech Connect

Rf, atmospheric-pressure glow discharge (APGD) plasmas with bare metal electrodes have promising prospects in the fields of plasma-aided etching, thin film deposition, disinfection and sterilization, etc. In this paper, the discharge characteristics are presented for the rf APGD plasmas generated with pure argon or argon-ethanol mixture as the plasma-forming gas and using water-cooled, bare copper electrodes. The experimental results show that the breakdown voltage can be reduced significantly when a small amount of ethanol is added into argon, probably due to the fact that the Penning ionization process is involved, and a pure {alpha}-mode discharge can be produced more easily with the help of ethanol. The uniformity of the rf APGDs of pure argon or argon-ethanol mixtures using bare metallic electrodes is identified with the aid of the intensified charge coupled device images.

Sun Wenting; Li Guo; Li Heping; Bao Chengyu; Wang Huabo; Zeng Shi; Gao Xing; Luo Huiying [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); School of Public Health and Family Medicine, Capital University of Medical Sciences, Beijing 100069 (China); Beijing Center for Diseases Control and Prevention, Beijing 100013 (China)

2007-06-15

97

Abnormal haemoglobins: detection & characterization  

PubMed Central

Haemoglobin (Hb) abnormalities though quite frequent, are generally detected in populations during surveys and programmes run for prevention of Hb disorders. Several methods are now available for detection of Hb abnormalities. In this review, the following are discussed: (i) the methods used for characterization of haemoglobin disorders; (ii) the problems linked to diagnosis of thalassaemic trait; (iii) the strategy for detection of common Hb variants; and (iv) the difficulties in identification of rare variants. The differences between developing and industrialized countries for the strategies employed in the diagnosis of abnormal haemoglobins are considered. We mention the limits and pitfalls for each approach and the necessity to characterize the abnormalities using at least two different methods. The recommended strategy is to use a combination of cation-exchange high performance chromatography (CE-HPLC), capillary electrophoresis (CE) and when possible isoelectric focusing (IEF). Difficult cases may demand further investigations requiring specialized protein and/or molecular biology techniques. PMID:22089618

Wajcman, Henri; Moradkhani, Kamran

2011-01-01

98

Tooth - abnormal colors  

MedlinePLUS

... Questions may involve: When the abnormal coloration began Foods you have been eating Medications you are taking Personal and family health history Exposure to fluoride Oral care habits Other symptoms ...

99

"Jeopardy" in Abnormal Psychology.  

ERIC Educational Resources Information Center

Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

Keutzer, Carolin S.

1993-01-01

100

EmergencyEmergency and Abnormal Situationsand Abnormal Situations  

E-print Network

SituationsAbnormal Situations Neil Johnston Aerospace Psychology Research Group Trinity College DublinEmergencyEmergency and Abnormal Situationsand Abnormal Situations in Aviation Symposiumin Aviation Symposium Santa Clara, June 2003 #12;Responding toResponding to Emergencies andEmergencies and Abnormal

101

Sensitive glow discharge ion source for aerosol and gas analysis  

DOEpatents

A high sensitivity glow discharge ion source system for analyzing particles includes an aerodynamic lens having a plurality of constrictions for receiving an aerosol including at least one analyte particle in a carrier gas and focusing the analyte particles into a collimated particle beam. A separator separates the carrier gas from the analyte particle beam, wherein the analyte particle beam or vapors derived from the analyte particle beam are selectively transmitted out of from the separator. A glow discharge ionization source includes a discharge chamber having an entrance orifice for receiving the analyte particle beam or analyte vapors, and a target electrode and discharge electrode therein. An electric field applied between the target electrode and discharge electrode generates an analyte ion stream from the analyte vapors, which is directed out of the discharge chamber through an exit orifice, such as to a mass spectrometer. High analyte sensitivity is obtained by pumping the discharge chamber exclusively through the exit orifice and the entrance orifice.

Reilly, Peter T. A. (Knoxville, TN)

2007-08-14

102

Radiation effects on ETFE polymer exposed to glow discharge  

NASA Astrophysics Data System (ADS)

The polymer ethylenetetrafluoroethylene (ETFE) is composed of alternating ethylene and tetrafluoroethylene segments. Because it has applications in areas such as medical physics and industrial coatings, there is a great interest in surface modification studies of ETFE polymer. When this material is exposed to ionizing radiation it suffers damage that depends on the type, energy and intensity of the irradiation. In order to determine the radiation damage mechanism from exposure to low voltage plasma, ETFE films were exposed to residual gas plasma in glow discharge regime to a fluence of 2 × 10 17 ions/cm 2. Irradiated films were analyzed with optical absorption photospectrometry, Fourier transform infrared (FTIR) and Raman spectroscopy to determine the chemical nature of the structural changes caused by low energy glow discharge.

Minamisawa, Renato Amaral; Abidzina, Volha; de Almeida, Adelaide; Budak, Satilmis; Tereshko, I.; Elkin, I.; Ila, Daryush

2007-08-01

103

Models of Abnormal Scarring  

PubMed Central

Keloids and hypertrophic scars are thick, raised dermal scars, caused by derailing of the normal scarring process. Extensive research on such abnormal scarring has been done; however, these being refractory disorders specific to humans, it has been difficult to establish a universal animal model. A wide variety of animal models have been used. These include the athymic mouse, rats, rabbits, and pigs. Although these models have provided valuable insight into abnormal scarring, there is currently still no ideal model. This paper reviews the models that have been developed. PMID:24078916

Seo, Bommie F.; Lee, Jun Yong; Jung, Sung-No

2013-01-01

104

Inception of Snapover and Gas Induced Glow Discharges  

NASA Technical Reports Server (NTRS)

Ground based experiments of the snapover phenomenon were conducted in the large vertical simulation chamber at the Glenn Research Center (GRC) Plasma Interaction Facility (PIF). Two Penning sources provided both argon and xenon plasmas for the experiments. The sources were used to simulate a variety of ionospheric densities pertaining to a spacecraft in a Low Earth Orbital (LEO) environment. Secondary electron emission is believed responsible for dielectric surface charging, and all subsequent snapover phenomena observed. Voltage sweeps of conductor potentials versus collected current were recorded in order to examine the specific charging history of each sample. The average time constant for sample charging was estimated between 25 and 50 seconds for all samples. It appears that current drops off by approximately a factor of 3 over the charging time of the sample. All samples charged in the forward and reverse bias directions, demonstrated hysteresis. Current jumps were only observed in the forward or positive swept voltage direction. There is large dispersion in tile critical snapover potential when repeating sweeps on any one sample. The current ratio for the first snapover region jumps between 2 and 4.6 times, with a standard deviation less than 1.6. Two of the samples showed even larger current ratios. It is believed the second large snapover region is due to sample outgassing. Under certain preset conditions, namely at the higher neutral gas background pressures, a perceptible blue-green glow was observed around the conductor. The glow is believed to be a result of secondary electrons undergoing collisions with an expelled tenuous cloud of gas, that is outgassed from the sample. Spectroscopic measurements of the glow discharge were made in an attempt to identify specific lines contributing to the observed glow.

Galofaro, J. T.; Vayner, B. V.; Degroot, W. A.; Ferguson, D. C.; Thomson, C. D.; Dennison, J. R.; Davies, R. E.

2000-01-01

105

Dynamical analysis of a helium glow discharge. I A model  

NASA Astrophysics Data System (ADS)

In this Letter, we investigate a model elaborated by Wilke et al. to explain various regimes observed in a helium glow discharge [Phys. Lett. A 136 (1989) 114] for which the underlying dynamics can be chaotic, quasi-periodic, etc. We found that this model does not obey all the required physical principles. A new one is therefore proposed. It is mainly based on separated balance equations for charged species resulting from the propagation of ionization waves.

Bultel, Arnaud; Letellier, Christophe; Bourdon, Anne

2004-03-01

106

The use of dc glow discharges as undergraduate educational tools  

NASA Astrophysics Data System (ADS)

Plasmas have a beguiling way of getting students interested in physics. We argue that plasmas can and should be incorporated into the undergraduate curriculum as both demonstrations and advanced investigations of electromagnetism and quantum effects. We describe a device, based on a direct-current (dc) glow discharge tube, which allows for a number of experiments into topics such as electrical breakdown, spectroscopy, magnetism, and electron temperature.

Wissel, Stephanie A.; Zwicker, Andrew; Ross, Jerry; Gershman, Sophia

2013-09-01

107

The Use of DC Glow Discharges as Undergraduate Educational Tools  

SciTech Connect

Plasmas have a beguiling way of getting students excited and interested in physics. We argue that plasmas can and should be incorporated into the undergraduate curriculum as both demonstrations and advanced investigations of electromagnetism and quantum effects. Our device, based on a direct current (DC) glow discharge tube, allows for a number of experiments into topics such as electrical breakdown, spectroscopy, magnetism, and electron temperature.

Stephanie A. Wissel and Andrew Zwicker, Jerry Ross, and Sophia Gershman

2012-10-09

108

Analysis of thermoluminescent glow peaks of zoisite under beta irradiations  

SciTech Connect

In this study, the thermoluminescence (TL) properties of natural crystal of zoisite were investigated after beta ({sup 90}Sr) irradiation at room temperature (RT). Zoisite, of chemical formula Ca{sub 2}Al{sub 3}(SiO{sub 4})(Si{sub 2}O{sub 7})O(OH), is found in Minas Gerais State, Brazil as natural mineral of silicate, member of the epidote group. The glow curve of a natural sample submitted to a heat treatment at 600 deg. C is composed of two broad peaks, centered at about 110-130 deg. C and another one at about 205-210 deg. C. A heating rate of 4 deg. C s{sup -1} was used in the temperature range from RT to 300 deg. C. The additive dose, T{sub m}-T{sub STOP} thermal cleaning, initial rise, variable heating rate and computerized glow curve deconvolution methods have shown that the glow curve is a superposition of six peaks at 100, 130, 155, 175, 200 and 230 deg. C. The trapping parameters for the individual peaks have been calculated. The TL dose response of 130 and 200 deg. C peaks has a linear response. Zoisite is a candidate for a TL dosimeter because of its high sensitivity.

Ccallata, Henry Javier; Watanabe, Shigueo [Department of Nuclear Physics, Institute of Physics, University of Sao Paulo, CP: 66.318, Sao Paulo-SP 05315-970 (Brazil)

2010-08-04

109

Development of blood compatible materials by glow discharge-treatment  

NASA Astrophysics Data System (ADS)

Glow discharge-treatment was applied to preparation of blood compatible materials. Plasticized polyvinylchloride (PVC) which is used for blood bags was treated in the presence of various gases or monomers. Wettability of PVC was modified by the treatment over a wide range. And leakage of plasticizer, di-(2-ethylhexyl)phthalate (DEHP), was prevented. When platelet concentrates were stored in the treated PVC bags, impairment of platelet functions was suppressed by the prevention of DEHP leakage. But platelet adhesion to the surfaces increased by the treatments. Aldehyde groups were grafted on polyethylene film (PE) by glow discharge-treatment in the presence of formaldehyde gas. Although the aldehyde-grafted PE (HCHO-PE) had higher reactivity with platelet than PE after albumin coating, it exhibited excellent antithrombogenicity after blood plasma coating. HCHO-PE adsorbed proteins with almost the same composition as blood plasma, although non-treated PE adsorbed proteins with higher fibinogen/albumin ratio. Segmented-polyurethane which is well known to exhibit good antithrombogenicity, also formed the adsorption layer having composition like that of blood plasma. These results suggest that protein layer adsorbed with blood plasma composition is hardly recognized by platelets. Glow discharge-treatment is a simple and effective method for surface modification of medical polymers.

Ishikawa, Y.; Sasakawa, S.

110

Space shuttle Ram glow: Implication of NO2 recombination continuum  

NASA Astrophysics Data System (ADS)

The ram glow data gathered to data from imaging experiments on space shuttle suggest the glow is a continuum (within 34 angstrom resolution); the continuum shape is such that the peak is near 7000 angstroms decreasing to the blue and red, and the average molecular travel leading to emission after leaving the surface is 20 cm (assuming isotropic scattering from the surface). Emission continuum is rare in molecular systems but the measured spectrum does resemble the laboratory spectrum of NO2 (B) recombination continuum. The thickness of the observed emission is consistent with the NO2 hypothesis given an exit velocity of approx. 2.5 km/sec (1.3 eV) which leaves approx. 3.7 eV of ramming OI energy available for unbonding the recombined NO2 from the surface. The NO2 is formed in a 3-body recombination of OI + NO + m = NO2 + m where OI originates from the atmosphere and NO is chemically formed on the surface from atmospheric NI and OI. The spacecraft surface then acts as the n for the reaction: Evidence exists from orbital mass spectrometer data that the NO and NO2 chemistry described in this process does occur on surfaces of spectrometer orifices in orbit. Surface temperature effects are likely a factor in the NO sticking efficiency and, therefore, glow intensities.

Swenson, G. R.; Mende, S. B.; Clifton, S.

1985-09-01

111

Detection of Abnormal Hemoglobins.  

National Technical Information Service (NTIS)

An intensive literature survey was performed to review the methods and products used to detect, identify and/or quantitate abnormal or variant hemoglobins in human erythrocytes. The report consists of a bibliography (198 citations, 1968-1979) and a summar...

J. Atwater, B. E. Hindman, K. Joseph

1979-01-01

112

Abnormal Psychology Psychology 280  

E-print Network

psychopathology perspective to understand: 2.1. risk and protective factors influencing the etiology abnormal behavior in everyday life and we need to gain a better understanding of the etiology, social worker, therapist, etc.) directly rely on having extensive knowledge of psychopathology. #12

Liu, Taosheng

113

Spatiotemporal laser perturbation of competing ionization waves in a neon glow discharge  

NASA Astrophysics Data System (ADS)

The experimental verification of spatiotemporal periodic pulling, a specific but universal phenomenon associated with driven, nonlinear, spatiotemporal systems, is reported as part of a study characterizing the ability of dc and chopped laser light to induce periodic pulling in ionization waves propagating in a neon glow-discharge plasma. The degree to which a single-mode laser beam at a metastable transition of 6401 Å (1s5-2p9) influences the discharge is found to depend on the location and magnitude of the perturbation. Cases of ac (chopping the light) and dc perturbation are presented. In a range of chopping frequencies above and below the ionization wave's undriven frequency, the wave can become synchronized to the perturbation. This entrainment range is shown to depend on the frequency difference between the wave and the perturbation, as well as on the perturbation distance from the cathode. Hysteresis is found in the value of the perturbation frequency associated with transitions into and out of entrainment. Outside of entrainment, periodic pulling of a self-excited, propagating, ionization wave by the laser perturbation is observed. This is a case of frequency pulling, or temporal periodic pulling. Inside of entrainment, the chopped laser light controls the frequency and amplitude of the mode. By properly adjusting the frequency and amplitude of one mode with respect to a second mode, periodic pulling of one ionization wave by the mode-locked, propagating, original ionization wave is demonstrated. This is a case of spatiotemporal pulling, involving both wavelength pulling and frequency pulling. Under proper conditions, competition between temporal and spatiotemporal periodic pulling results in a modulation in the dynamics of the system, a process referred to as dynamics modulation.

Weltmann, K.-D.; Koepke, M. E.; Selcher, C. A.

2000-08-01

114

Spatiotemporal laser perturbation of competing ionization waves in a neon glow discharge  

PubMed

The experimental verification of spatiotemporal periodic pulling, a specific but universal phenomenon associated with driven, nonlinear, spatiotemporal systems, is reported as part of a study characterizing the ability of dc and chopped laser light to induce periodic pulling in ionization waves propagating in a neon glow-discharge plasma. The degree to which a single-mode laser beam at a metastable transition of 6401 A (1s(5)-2p(9)) influences the discharge is found to depend on the location and magnitude of the perturbation. Cases of ac (chopping the light) and dc perturbation are presented. In a range of chopping frequencies above and below the ionization wave's undriven frequency, the wave can become synchronized to the perturbation. This entrainment range is shown to depend on the frequency difference between the wave and the perturbation, as well as on the perturbation distance from the cathode. Hysteresis is found in the value of the perturbation frequency associated with transitions into and out of entrainment. Outside of entrainment, periodic pulling of a self-excited, propagating, ionization wave by the laser perturbation is observed. This is a case of frequency pulling, or temporal periodic pulling. Inside of entrainment, the chopped laser light controls the frequency and amplitude of the mode. By properly adjusting the frequency and amplitude of one mode with respect to a second mode, periodic pulling of one ionization wave by the mode-locked, propagating, original ionization wave is demonstrated. This is a case of spatiotemporal pulling, involving both wavelength pulling and frequency pulling. Under proper conditions, competition between temporal and spatiotemporal periodic pulling results in a modulation in the dynamics of the system, a process referred to as dynamics modulation. PMID:11088758

Weltmann; Koepke; Selcher

2000-08-01

115

Numerical investigations of formation and realignment of regular current structures in elevated pressure glow discharge  

NASA Astrophysics Data System (ADS)

Within the frame of a fluid drift-diffusion model the possibility of a current instability growth in elevated gas discharge was numerically investigated. Under physically reasonable assumptions about the values of characteristic electron energy and secondary emission coefficient, we observed the growth of perturbations and formation of a periodic in space current structure. However, competition between the current stripes has a substantial effect on their evolution, leading to suppressing of the neighboring current stripes. Further inspection of numerical solution discloses that the instabilities growth begins in anode region, but the net result essentially depends on the processes in cathode region. The cathode spots are markedly less in size than the anode spots, and their current densities differ widely. To account for several phenomenological aspects of formation of constricted discharge structures and cooperative interplay thereof, a simple one-dimensional physical model is proposed. It should be noted that a development of the current structures of the abnormal glow exhibits a nonthreshold nature and owes its origin to the purely electrodynamical phenomenon long before the emergence of the bulk thermal, plasma chemistry, and nonlinear surface effects.

Islamov, R. S.

2002-04-01

116

Adequately address abnormal operations  

SciTech Connect

Abnormal situation management (ASM) is a safety issue, and safety long has been a top priority for companies in the chemical process industries (CPI). To investigate and identify root causes of abnormal operations and to pinpoint best practices for preventing these situations or at least handling them most effectively, the author formed a team and conducted surveys around the world, including the US, Canada, the United Kingdom, Europe, and Japan. The author visited a variety of facilities, including gas processing plants, oil refineries, a coker, ethylene plant, polyethylene units, steam-generating stations, as well as transportation and storage facilities. The team identified eight key issues: lack of management leadership; the significant role of human errors; inadequate design of the work environment; absence of procedures for dealing with abnormal operations (as opposed to emergencies); loss of valuable information from earlier minor incidents; the potential economic return; transferability of good ASM performance to other plants; and the importance of teamwork and job design. The paper looks at each of these in more detail, as well as what`s involved in assessing the ASM at a site.

Nimmo, I. [Honeywell Industrial Automation and Control, Phoenix, AZ (United States)

1995-09-01

117

Multiple solutions in the theory of dc glow discharges and cathodic part of arc discharges. Application of these solutions to the modeling of cathode spots and patterns: a review  

NASA Astrophysics Data System (ADS)

A new class of stationary solutions in the theory of glow discharges and plasma–cathode interaction in ambient-gas arc discharges has been found over the past 15 years. These solutions exist simultaneously with the solution given in textbooks, which describes a discharge mode with a uniform or smooth distribution of current over the cathode surface, and describes modes with various configurations of cathode spots: normal spots on glow cathodes, patterns of multiple spots recently observed on cathodes of glow microdischarges and spots on arc cathodes. In particular, these solutions show that cathode spots represent a manifestation of self-organization caused by basic mechanisms of the near-cathode space-charge sheath; another illustration of the richness of the gas discharge science. As far as arc cathodes are concerned, the new solutions have proved relevant for industrial applications. This work is dedicated to reviewing the multiple solutions obtained to date, their systematization, and analysis of their properties and physical meaning. The treatment is performed in the context of general trends of self-organization in bistable nonlinear dissipative systems, which allows one to consider glow discharges or arc–cathode interaction within a single physically transparent framework without going into mathematical details and offers a possibility of systematic computation of the multiple solutions. Relevant computational aspects and experimental data are discussed.

Benilov, M. S.

2014-10-01

118

Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.  

ERIC Educational Resources Information Center

Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal

Fernald, Charles D.

1980-01-01

119

Large Scale Modelling of Glow Discharges or Non - Plasmas  

NASA Astrophysics Data System (ADS)

The Electron Velocity Distribution Function (EVDF) in the cathode fall of a DC helium glow discharge was evaluated from a numerical solution of the Boltzmann Transport Equation(BTE). The numerical technique was based on a Petrov-Galerkin technique and a unique combination of streamline upwinding with self -consistent feedback-based shock-capturing. EVDF for the cathode fall was solved at 1 Torr, as a function of position x, axial velocity v_{rm x}, radial velocity v_{rm r}, and time t. The electron-neutral collisions consisted of elastic, excitation, and ionization processes. The algorithm was optimized and vectorized to speed execution by more than a factor of 10 on CRAY-XMP. Efficient storage schemes were used to save the memory allocation required by the algorithm. The analysis of the solution of BTE was done in terms of the 8-moments that were evaluated. Higher moments were found necessary to study the momentum and energy fluxes. The time and length scales were estimated and used as a basis for the characterization of DC glow discharges. Based on an exhaustive study of Knudsen numbers, it was observed that the electrons in the cathode fall were in the transition or Boltzmann regime. The shortest relaxation time was the momentum relaxation and the longest times were the ionization and energy relaxation times. The other times in the processes were that for plasma reaction, diffusion, convection, transit, entropy relaxation, and that for mean free flight between the collisions. Different models were classified based on the moments, time scales, and length scales in their applicability to glow discharges. These consisted of BTE with different number af phase and configuration dimensions, Bhatnagar-Gross-Krook equation, moment equations (e.g. Drift-Diffusion, Drift-Diffusion-Inertia), and spherical harmonic expansions.

Shankar, Sadasivan

120

Shock wave formation in a dc glow discharge dusty plasma.  

PubMed

A jump of dust density propagating through the dusty plasma structure has been observed. To excite the disturbance an impulse of axial magnetic field to the dusty plasma in a dc glow discharge striation has been applied. This impulse resulted in the dynamical stretching of the dusty plasma structure. During the reconstruction of the structure a ramp-shaped perturbation of dust density appeared. The perturbation was steepening and formed into a dust-acoustic shock. The anomalously high shock compression is observed. PMID:15903594

Fortov, V E; Petrov, O F; Molotkov, V I; Poustylnik, M Y; Torchinsky, V M; Naumkin, V N; Khrapak, A G

2005-03-01

121

Reproducing continuous radio blackout using glow discharge plasma.  

PubMed

A novel plasma generator is described that offers large-scale, continuous, non-magnetized plasma with a 30-cm-diameter hollow structure, which provides a path for an electromagnetic wave. The plasma is excited by a low-pressure glow discharge, with varying electron densities ranging from 10(9) to 2.5 × 10(11) cm(-3). An electromagnetic wave propagation experiment reproduced a continuous radio blackout in UHF-, L-, and S-bands. The results are consistent with theoretical expectations. The proposed method is suitable in simulating a plasma sheath, and in researching communications, navigation, electromagnetic mitigations, and antenna compensation in plasma sheaths. PMID:24182138

Xie, Kai; Li, Xiaoping; Liu, Donglin; Shao, Mingxu; Zhang, Hanlu

2013-10-01

122

NSTX Filament Preionization and Glow Discharge Cleaning Systems  

SciTech Connect

Initial NSTX GDC experiments were performed with one moveable anode and a biased filament preionization system that allowed D2 and He Glow Discharge breakdowns at the actual operating pressure, voltage and current. The biased filament system was also operated continuously during ohmic operations, and used to reduce volt-sec consumption for February 1999 plasma discharges up to 280 KA. An upgraded system has been installed with 2 fixed wall anodes and 3 biased filaments; 2 on the mid-plane and one in the divertor region; all separately controllable remotely using a PLC system. Recent applications include assisting in preionization for 800 KA plasma discharges.

H.W. Kugel, W. Blanchard, G. D'Amico, R. Gernhardt, T. Provost

1999-11-01

123

Reproducing continuous radio blackout using glow discharge plasma  

NASA Astrophysics Data System (ADS)

A novel plasma generator is described that offers large-scale, continuous, non-magnetized plasma with a 30-cm-diameter hollow structure, which provides a path for an electromagnetic wave. The plasma is excited by a low-pressure glow discharge, with varying electron densities ranging from 109 to 2.5 × 1011 cm-3. An electromagnetic wave propagation experiment reproduced a continuous radio blackout in UHF-, L-, and S-bands. The results are consistent with theoretical expectations. The proposed method is suitable in simulating a plasma sheath, and in researching communications, navigation, electromagnetic mitigations, and antenna compensation in plasma sheaths.

Xie, Kai; Li, Xiaoping; Liu, Donglin; Shao, Mingxu; Zhang, Hanlu

2013-10-01

124

Reproducing continuous radio blackout using glow discharge plasma  

SciTech Connect

A novel plasma generator is described that offers large-scale, continuous, non-magnetized plasma with a 30-cm-diameter hollow structure, which provides a path for an electromagnetic wave. The plasma is excited by a low-pressure glow discharge, with varying electron densities ranging from 10{sup 9} to 2.5 × 10{sup 11} cm{sup ?3}. An electromagnetic wave propagation experiment reproduced a continuous radio blackout in UHF-, L-, and S-bands. The results are consistent with theoretical expectations. The proposed method is suitable in simulating a plasma sheath, and in researching communications, navigation, electromagnetic mitigations, and antenna compensation in plasma sheaths.

Xie, Kai; Li, Xiaoping; Liu, Donglin; Shao, Mingxu [School of Aerospace Science and Technology, Xidian University, Xi'an 710071 (China)] [School of Aerospace Science and Technology, Xidian University, Xi'an 710071 (China); Zhang, Hanlu [School of Communication and Information Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121 (China)] [School of Communication and Information Engineering, Xi'an University of Posts and Telecommunications, Xi'an 710121 (China)

2013-10-15

125

Laser-excited atomic fluorescence in a pulsed glow discharge  

NASA Astrophysics Data System (ADS)

A pulsed demountable glow discharge has been used as an atom cell for laser excited atomic fluorescence. Lead atoms are sputtered from the surface of copper and graphite cathodes and are excited by a pulsed frequency-doubled dye laser after the discharge is switched off. The combination of a "dark" atom cell with non-resonance atomic fluorescence leads to a very low background signal. The detection limit for lead in copper is 0.1 ?g/g and for lead in aqueous solutions (5 ?l) deposited on graphite electrodes is 20 pg.

Smith, B. W.; Omenetto, N.; Winefordner, J. D.

126

High-rate carburizing in a glow discharge methane plasma  

Microsoft Academic Search

Carburizing at high temperature (1040?C) in a glow-discharge methane plasma signifi-cantly reduces carburizing time. Sufficient\\u000a carbon to produce a 1.0 mm case on conven-tional carburizing steels can be introduced in 10 min at methane pressures in the\\u000a range of 1.3 to 2.7 kPa (10 to 20 Torr). To reduce the carbon concentration at the surface to an acceptable level (007E1.0

William L. Grube; Jack G. Gay

1978-01-01

127

Roentgenologic Abnormalities in Down's Syndrome.  

National Technical Information Service (NTIS)

Roentgenograms of 28 patients with Down's syndrome were reviewed with emphasis on all previously reported abnormalities and any possible additional ones. Most of the abnormalities occurred with the same frequency as previously reported, but some less freq...

T. Higuchi, W. J. Russell, M. Komatsuda, S. Neriishi

1968-01-01

128

Bored By Non-Glowing Skin? Ultra-Flexible, Waterproof LED Implants Are What You Seek  

E-print Network

Bored By Non-Glowing Skin? Ultra-Flexible, Waterproof LED Implants Are What You Seek By Alasdair LEDs Pliable: Photo courtesy of iO9 Page 1 of 4Bored By Non-Glowing Skin? Ultra-Flexible, Waterproof your spine for the sexy Cylon look!) Take your boring old household pets and stick some LEDs in them

Rogers, John A.

129

The analysis of thermoluminescent glow peaks of CaF : Dy (TLD-200) after -irradiation  

E-print Network

at a heating rate of 6°C s-1 . It has been found that all the studied peaks in the glow curve of this material at stacks.iop.org/JPhysD/35/2526 Abstract Variable dose (VD), Tm­Tstop, initial rise (IR), variable heating rate (VHR), peak shape (PS) and computerized glow curve deconvolution (CGCD) methods are used

Chen, Reuven

130

A Review on Chemical Effects in Aqueous Solution induced by Plasma with Glow Discharge  

NASA Astrophysics Data System (ADS)

Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge characteristics are also reviewed. These are followed by a discussion of their mechanisms of both anodic and cathodic CGDE..

Gao, Jin-zhang; Wang, Xiao-yan; Hu, Zhong-ai; Hou, Jing-guo; Lu, Quan-fang

2001-06-01

131

Tropospheric wind measurements obtained with the Goddard Lidar Observatory for Winds (GLOW): validation and performance  

Microsoft Academic Search

The Goddard Lidar Observatory for Winds (GLOW) is a mobile Doppler lidar system which uses direct detection Doppler lidar techniques to measure wind profiles from the surface into the lower stratosphere. GLOW is intended to be used as a field deployable system for studying atmospheric dynamics and transport and can also serve as a testbed to evaluate candidate technologies developed

Bruce M. Gentry; Huailin Chen

2002-01-01

132

Epilepsy and chromosomal abnormalities  

Microsoft Academic Search

Background  Many chromosomal abnormalities are associated with Central Nervous System (CNS) malformations and other neurological alterations,\\u000a among which seizures and epilepsy. Some of these show a peculiar epileptic and EEG pattern. We describe some epileptic syndromes\\u000a frequently reported in chromosomal disorders.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Detailed clinical assessment, electrophysiological studies, survey of the literature.\\u000a \\u000a \\u000a \\u000a Results  In some of these congenital syndromes the clinical presentation and EEG

Giovanni Sorge; Anna Sorge

2010-01-01

133

Spirometric abnormalities among welders  

SciTech Connect

A group of manual welders age group 13-60 years having a mean exposure period of 12.4 {plus minus} 1.12 years were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The welders showed a significantly higher prevalence of respiratory impairment than that observed among the unexposed controls as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the expose group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment followed by a mixed ventilatory defect among the welders. The effect of age on pulmonary impairment was not discernible. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years. Smoking also had a contributory role.

Rastogi, S.K.; Gupta, B.N.; Husain, T.; Mathur, N.; Srivastava, S. (Industrial Toxicology Research Centre, Lucknow (India))

1991-10-01

134

Interaction of a surface glow discharge with a gas flow  

SciTech Connect

A surface glow discharge in a gas flow is of particular interest as a possible tool for controlling the flow past hypersonic aircrafts. Using a hydrodynamic model of glow discharge, two-dimensional calculations for a kilovolt surface discharge in nitrogen at a pressure of 0.5 Torr are carried out in a stationary gas, as well as in a flow with a velocity of 1000 m/s. The discharge structure and plasma parameters are investigated near a charged electrode. It is shown that the electron energy in a cathode layer reaches 250-300 eV. Discharge is sustained by secondary electron emission. The influence of a high-speed gas flow on the discharge is considered. It is shown that the cathode layer configuration is flow-resistant. The distributions of the electric field and electron energy, as well as the ionization rate profile in the cathode layer, do not change qualitatively under the action of the flow. The basic effect of the flow's influence is a sharp decrease in the region of the quasineutral plasma surrounding the cathode layer due to fast convective transport of ions.

Aleksandrov, A. L., E-mail: a_alex@itam.nsc.ru; Schweigert, I. V. [Russian Academy of Sciences, Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch (Russian Federation)

2010-05-15

135

Dust particle radial confinement in a dc glow discharge.  

PubMed

A self-consistent nonlocal model of the positive column of a dc glow discharge with dust particles is presented. Radial distributions of plasma parameters and the dust component in an axially homogeneous glow discharge are considered. The model is based on the solution of a nonlocal Boltzmann equation for the electron energy distribution function, drift-diffusion equations for ions, and the Poisson equation for a self-consistent electric field. The radial distribution of dust particle density in a dust cloud was fixed as a given steplike function or was chosen according to an equilibrium Boltzmann distribution. The balance of electron and ion production in argon ionization by an electron impact and their losses on the dust particle surface and on the discharge tube walls is taken into account. The interrelation of discharge plasma and the dust cloud is studied in a self-consistent way, and the radial distributions of the discharge plasma and dust particle parameters are obtained. It is shown that the influence of the dust cloud on the discharge plasma has a nonlocal behavior, e.g., density and charge distributions in the dust cloud substantially depend on the plasma parameters outside the dust cloud. As a result of a self-consistent evolution of plasma parameters to equilibrium steady-state conditions, ionization and recombination rates become equal to each other, electron and ion radial fluxes become equal to zero, and the radial component of electric field is expelled from the dust cloud. PMID:23410440

Sukhinin, G I; Fedoseev, A V; Antipov, S N; Petrov, O F; Fortov, V E

2013-01-01

136

Ozone generation using atmospheric pressure glow discharge in air  

NASA Astrophysics Data System (ADS)

This paper presents results from a study into the generation of ozone by a stable atmospheric glow discharge, using dry air as the feeding gas for ozone generation. The power supply is 50 Hz ac, with the use of a perforated aluminium sheet for the electrodes and soda lime glass as a dielectric layer in a parallel-plate configuration, stabilizing the generation process and enabling ozone to be produced. The stable glow discharge spreads uniformly at a gas breakdown voltage below 4.8 kV and requires only 330 mW discharge power, with a limitation of 3 mm on the maximum gap spacing for the dry air. With the technique providing a high collision rate between the electrons and gas molecules during the discharge process, a high ozone yield is obtained. An analysis of the effect on the production rate of parameters such as the input voltage, gas flow rate and reaction chamber dimensions resulted in a highest efficiency of production of almost 350 g kWh-1 and confirms its potential as an important ozone generation technology.

Buntat, Z.; Smith, I. R.; Razali, N. A. M.

2009-12-01

137

Closed form analytic solutions describing glow discharge plasma  

NASA Astrophysics Data System (ADS)

On the basis of an analytic model developed previously [S. T. Pai, J. Appl. Phys. 71, 5820 (1992)], an improved version of the model for the description of dc glow discharge plasma was successfully developed. A set of closed form solutions was obtained from the governing equations. The two-dimensional, analytic solutions are functional and completely satisfy the governing equations, the actual boundary conditions, and Maxwell equations. They can be readily used to carry out numerical calculations without the necessity of employing any assumed boundary conditions. Results obtained from the model reveal that as the discharge gap spacing or pressure increases the maximum value in the electron density distribution moves toward the cathode. At a sufficiently large value of gap spacing, the positive column phenomenon begins to appear in the discharge region. The model has the capability of treating the positive column and negative glow as a continuous system without the necessity of studying them separately. The model also predicts a sharp rise of the positive ion density near the cathode and field reversal in the anode region. Variation of the electrode radius produces little effect on the axial spatial distribution of physical quantities studied.

Pai, S. T.; Guo, X. M.; Zhou, T. D.

1996-10-01

138

A new technique of radiation thermometry using a consumer digital camcorder: Observations of red glow at Aso volcano, Japan  

NASA Astrophysics Data System (ADS)

We newly developed a technique of radiation thermometry using a Sony'fs consumer digital camcorder. Our system is not only convenience and cost effective but with a better performance than previous infrared thermometers, particularly in the place like a crater of volcano where is abundant in gas. This is because our system uses the submicron wavelength band, in which radiation is less influenced by absorption of gas than in the thermal infrared wavelength (>3 mm). We carried out observations of red glow at Aso volcano and succeeded in measuring the temperature of about 800°C, which is much more acceptable than previously reported values of 200-400°C. When we measure the temperature of about 300-700°C and 600-900°C in the place where is abundant in gas, using the camcorder with the near-infrared and with the visible wavelength mode is better than the thermal infrared region, respectively.

Saito, T.; Sakai, S.; Iizawa, I.; Suda, E.; Umetani, K.; Kaneko, K.; Furukawa, Y.; Ohkura, T.

2005-02-01

139

Flush-mounted probe diagnostics for argon glow discharge plasma  

NASA Astrophysics Data System (ADS)

A comparison is made between plasma parameters measured by a flush-mounted probe (FP) and a cylindrical probe (CP) in argon glow discharge plasma. Parameters compared include the space potential, the plasma density, and the effective electron temperature. It is found that the ion density determined by the FP agrees well with the electron density determined by the CP in the quasi-neutral plasma to better than 10%. Moreover, the space potential and effective electron temperature calculated from electron energy distribution function measured by the FP is consistent with that measured by the CP over the operated discharge current and pressure ranges. These results present the FP can be used as a reliable diagnostic tool in the stable laboratory plasma and also be anticipated to be applied in other complicated plasmas, such as tokamaks, the region of boundary-layer, and so on.

Xu, Liang; Cao, Jinxiang; Liu, Yu; Wang, Jian; Du, Yinchang; Zheng, Zhe; Zhang, Xiao; Wang, Pi; Zhang, Jin; Li, Xiao; Qin, Yongqiang; Zhao, Liang

2014-09-01

140

Fluorination of polymethylmethaacrylate with tetrafluoroethane using DC glow discharge plasma  

NASA Astrophysics Data System (ADS)

Fluorination of polymer surfaces has technological applications in various fields such as microelectronics, biomaterials, textile, packing, etc. In this study PMMA surfaces were fluorinated using DC glow discharge plasma. Tetrafluoroethane was used as the fluorinating agent. On the fluorinated PMMA surface, static water contact angle, surface energy, optical transmittance (UV-vis), XPS and AFM analyses were carried out. After the fluorination PMMA surface becomes hydrophobic with water contact angle of 107° without losing optical transparency. Surface energy of fluorine plasma-treated PMMA decreased from 35 mJ/cm 2 to 21.2 mJ/cm 2. RMS roughness of the fluorinated surface was 4.01 nm and XPS studies revealed the formation of C-CF x and CF 3 groups on the PMMA surface.

Guruvenket, S.; Iyer, Ganjigunte R. S.; Shestakova, Larisa; Morgen, Per; Larsen, N. B.; Mohan Rao, G.

2008-07-01

141

Determination of Actinide Isotope Ratios Using Glow Discharge Optogalvanic Spectroscopy  

SciTech Connect

Diode-laser excited optogalvanic spectroscopy (OGS) of a glow discharge has been utilized to measure U-235/U-235 + U-238 isotope ratios. This ``optical mass spectrometric`` measurement has been demonstrated for a number of samples including uranium oxide, fluoride, and metal. Various diode-laser accessible atomic transitions in the 775 to 835 nm region have been evaluated; these transitions were chosen by considering OGS sensitivity and isotope shift. Using the 831.84 nm uranium line, for example, it was possible to measure the U-235/U-235 + U-238 isotope ratio (0.0026) of depleted uranium samples. A prototypical field instrument to make these measurements has been assembled and demonstrated. A U-236 spectral line was identified in a sample of enriched uranium, and an abundance sensitivity was measured.

Young, J.P.; Shaw, R.W.; Barshick, C.M.; Ramsey, J.M.

1997-08-01

142

Hydrogen generation by glow discharge plasma electrolysis of ethanol solutions  

NASA Astrophysics Data System (ADS)

Glow discharge plasma electrolysis (GDPE) of ethanol solutions for hydrogen generation was investigated in terms of discharged voltage, discharged polarity and ethanol concentration. H2 and acetaldehyde are the dominant products of ethanol decomposition during GDPE. Discharged polarity, discharged voltage and ethanol concentration have important influences on the energy consumption, concentration and output of hydrogen and acetaldehyde. The hydrogen yield (G(H2)) by cathodic GDPE is higher than that of anodic GDPE. The energy consumption (Wr) was 5.12 kJ L-1 when the applied voltage of cathodic GDPE was 1000 V. The hydrogen concentration of cathodic GDPE in gases keeps above 80%. The experiments indicate that GDPE of ethanol solutions is an effective technology producing hydrogen and acetaldehyde simultaneously with low CO2 emission.

Yan, Zongcheng; Chen, Li; Wang, Honglin

2008-08-01

143

Critical parameters of a high-voltage glow discharge  

NASA Astrophysics Data System (ADS)

An equation (Ul'ianov, 1978) is presented defining the critical potential of a high-voltage glow discharge, and it is solved numerically. Self-maintained and externally maintained discharges are considered for the various elimination mechanisms of the charged particles. For the case of the externally maintained discharge, it is shown that (1) the field at the cathode begins to decrease with an increase of the potential when there is extensive gas ionization in the space-charge layer, and (2) the potential becomes zero at a certain critical value. Results are compared with those of an approximate analytic solution. An equation is also derived for the critical potential at higher pressures.

Ulianov, K. N.; Tskhai, A. B.

1981-07-01

144

Investigation of sheath phenomena in electronegative glow discharges  

NASA Astrophysics Data System (ADS)

Two different methods of analyzing the cathode fall region of low pressure glow discharge were developed and applied to three different electronegative gas mixtures. One method was based on a self-consistent numerical solution to Poisson's equation, the current continuity equations for electrons and negative ions, and the current conservation equation. This method assumes the electrons are always in equilibrium with the electric field. The other method was based on a self-consistent numerical solution of the Boltzmann transport equation for electrons, Poisson's equations, and the current conservation equation. This method allows the electrons not be in equilibrium with the field. Comparing these two methods revealed that nonequilibrium prevails throughout the cathode fall region. The electronegative gas mixtures investigated were small concentrations (less than 10%) of hydrogen chloride in helium, argon, or xenon.

Duke, G. L.

1983-12-01

145

The analysis of thermoluminescent glow peaks of natural calcite after beta irradiation.  

PubMed

In this study, the thermoluminescence properties of natural calcite samples were examined in detail. The glow curve of the sample irradiated with beta radiation shows two main peaks, P1 (at 115 °C) and P4 (at 254 °C). The additive dose, variable heating rate, computer glow curve deconvolution, peak shape and three point methods have been used to evaluate the trapping parameters, namely the order of kinetics (b), activation energy (E) and the frequency factor (s) associated with the dosimetric thermoluminescent glow peaks (P1 and P4) of natural calcite after different dose levels with beta irradiation. PMID:22355170

Yildirim, R Güler; Kafadar, V Emir; Yazici, A Necmeddin; Gün, Esen

2012-09-01

146

Dust Waves Excited in a DC Glow Discharge Plasma  

SciTech Connect

We present a review of experimental studies to excite nonlinear dust waves in a dc glow discharge plasma. The experiments were performed in a vertically positioned glass tube filled with neon and the stratified glow discharge with cold electrodes was created inside it. Dust particles were injected into a plasma and formed ordered structures in the striations. The dust grains were illuminated with a laser sheet and the scattered light was registered with a high-speed digital videocamera with the frame rate of 1000 fps and spatial resolution of 20 {mu}m/pixel. We performed experiments with different techniques of the wave excitation. First, we used the gas-dynamic impact to move the dusty plasma structure with respect to their trap. In this case a large-amplitude wave with two compressional regions separated by a rarefaction was generated. The second wave excitation method was the application of an electromagnetic impulse to the dusty plasma structure. The impulse was created by the discharge of a high-voltage capacitor into a flat coil reeled around the discharge tube. The impulse of the axial magnetic field excited a perturbation. The perturbation had a character of discontinuity of the dust density and velocity. The perturbation was steepening and formed into a dust-acoustic shock. One more method of the wave excitation was developed that allowed to get two pulses. This gives us a possibility to investigate an interaction of waves excited in the dust component and a propagation of waves in a dusty plasma media with changeable dust density as well.

Torchinsky, V.M.; Naumkin, V.N.; Molotkov, V.I.; Fortov, V.E.; Petrov, O.F.; Khrapak, A.G.; Poustylnik, M.Y. [Institute for High Energy Densities, Russian Academy of Sciences, Moscow, 125412, Izhorskaya13/19 (Russian Federation)

2005-10-31

147

Dust Waves Excited in a DC Glow Discharge Plasma  

NASA Astrophysics Data System (ADS)

We present a review of experimental studies to excite nonlinear dust waves in a dc glow discharge plasma. The experiments were performed in a vertically positioned glass tube filled with neon and the stratified glow discharge with cold electrodes was created inside it. Dust particles were injected into a plasma and formed ordered structures in the striations. The dust grains were illuminated with a laser sheet and the scattered light was registered with a high-speed digital videocamera with the frame rate of 1000 fps and spatial resolution of 20 ?m/pixel. We performed experiments with different techniques of the wave excitation. First, we used the gas-dynamic impact to move the dusty plasma structure with respect to their trap. In this case a large-amplitude wave with two compressional regions separated by a rarefaction was generated. The second wave excitation method was the application of an electromagnetic impulse to the dusty plasma structure. The impulse was created by the discharge of a high-voltage capacitor into a flat coil reeled around the discharge tube. The impulse of the axial magnetic field excited a perturbation. The perturbation had a character of discontinuity of the dust density and velocity. The perturbation was steepening and formed into a dust-acoustic shock. One more method of the wave excitation was developed that allowed to get two pulses. This gives us a possibility to investigate an interaction of waves excited in the dust component and a propagation of waves in a dusty plasma media with changeable dust density as well.

Torchinsky, V. M.; Naumkin, V. N.; Molotkov, V. I.; Fortov, V. E.; Petrov, O. F.; Khrapak, A. G.; Poustylnik, M. Y.

2005-10-01

148

Systemic abnormalities in liver disease  

PubMed Central

Systemic abnormalities often occur in patients with liver disease. In particular, cardiopulmonary or renal diseases accompanied by advanced liver disease can be serious and may determine the quality of life and prognosis of patients. Therefore, both hepatologists and non-hepatologists should pay attention to such abnormalities in the management of patients with liver diseases. PMID:19554648

Minemura, Masami; Tajiri, Kazuto; Shimizu, Yukihiro

2009-01-01

149

TMI abnormal waste project plan  

Microsoft Academic Search

This report discusses plans for the TMI Abnormal Waste Project, which is part of the EPICOR and Waste Research and Disposition Program and funded by the US Department of Energy. The sequence proposed for disposition of Three Mile Island (TMI) abnormal wastes includes: (a) packaging at TMI, (b) shipment to the Idaho National Engineering Laboratory (INEL), (c) storage at INEL

Ayers; A. L. Jr

1984-01-01

150

Students' reactions to abnormal psychology  

Microsoft Academic Search

As a result of some concern about the effect of courses in abnormal psychology on students, a questionnaire was presented to several classes at the close of the course. The majority answering the questionnaire felt the course to be beneficial, giving evidence that the study of abnormal psychology need not be generally harmful, and may have a significant place in

W. S. Taylor

1932-01-01

151

abnormalities in infants and toddlers  

E-print Network

, Akshoomoff 2000). Similarly, patients with fetal alcohol syndrome (FAS) have decreased cerebellar volumesCerebellar abnormalities in infants and toddlers with Williams syndrome Wendy Jones* PhD, The Salk-mail: jones@crl.ucsd.edu One commonly observed neuroanatomical abnormality in adults with Williams syndrome

Bellugi, Ursula

152

Analysis of Semi-Insulating Bulk GaAs Using Glow Discharge Mass Spectrometry.  

National Technical Information Service (NTIS)

The ability to perform sub-part per billion (ppb) analysis of semi-insulating (SI) GaAs substrate material is of critical importance for the development of electronic materials used in microelectronic device applications. Glow discharge mass spectrometry ...

A. E. Souzis, R. T. Lareau, R. Wittstruck

1993-01-01

153

Atmospheric DC Glow Microplasmas Using Miniature Gas Flow and Electrolyte Cathode  

NASA Astrophysics Data System (ADS)

We developed a new scheme to generate atmospheric dc glow discharges with a combination of an electrolyte cathode and a miniature gas flow. Stable glow discharges were obtained for a gap separation of 100-700 µm with a cathode of a sodium sulfate solution. The gap voltage increased with increasing a current up to 15 mA, above which the voltage became constant as the low-pressure glow discharges. Local boiling by the discharge at the surface of the sodium sulfate solution began at 15 mA. At the same time, the emission of an intense sodium atomic line appeared in the negative glow region. The pH of the solution decreased when the discharge was generated in ambient air. The reduction of pH was attributed to the existence of nitrogen oxide, which dissolved in the solution.

Shirai, Naoki; Nakazawa, Masato; Ibuka, Shinji; Ishii, Shozo

2009-03-01

154

Space Charge Structure of a Glow Discharge in the Presence of a Longitudinal Inhomogeneity.  

National Technical Information Service (NTIS)

A survey of space charge structures arising due to inhomogeneities in glow discharges was conducted. Space charge structures associated with tube geometries, the cathode sheath, striations, and shockwaves were examined. Space charge effects on the Electro...

F. A. Tersigni

1999-01-01

155

GlowBots: Designing and Implementing Engaging Human-Robot Interaction  

Microsoft Academic Search

GlowBots are small tangible, communicating and interactive robots that show eye-catching visual patterns on a round LED display. This paper details the development of the GlowBots from the early user-oriented design phase, through hardware and software development and onto preliminary user studies. In the design phase we outlined a robot application based on a study of how owners relate with

Mattias Jacobsson; Ylva Fernaeus; Lars Erik Holmquist

2008-01-01

156

Binary and ternary gas mixtures for use in glow discharge closing switches  

DOEpatents

Highly efficient binary and ternary gas mixtures for use in diffuse glow discharge closing switches are disclosed. The binary mixtures are combinations of helium or neon and selected perfluorides. The ternary mixtures are combinations of helium, neon, or argon, a selected perfluoride, and a small amount of gas that exhibits enhanced ionization characteristics. These mixtures are shown to be the optimum choices for use in diffuse glow discharge closing switches by virtue of the combined physio-electric properties of the mixture components.

Hunter, Scott R. (Oak Ridge, TN); Christophorou, Loucas G. (Oak Ridge, TN)

1990-01-01

157

Kinetic parameters, bleaching and radiation response of thermoluminescence glow peaks separated by deconvolution on Korean calcite  

NASA Astrophysics Data System (ADS)

Calcite has been of particular interest in studies of thermoluminescence (TL) because of its geological and archeological importance. Although extensive research on the TL glow curves of calcite has been conducted, most previous works have been based on the TL intensity integrated over a particular temperature range on the glow curve, without any separation of peaks. In this paper, the physical characteristics of the overlapping peaks in the TL glow curves of a calcite sample are investigated. These properties can provide useful information for determining the radiation dose absorbed to the sample in radiation dosimetry and luminescence dating research. The Tm-Tstop method is employed to identify the number of hidden glow peaks, and the kinetic parameters of each separated glow peak, including the thermal activation energy, kinetic order, and frequency factor, are evaluated using a computerized glow curve deconvolution (CGCD) method. The Tm-Tstop method indicates that the glow curve of calcite is the superposition of at least four components (P1 - P4) in the temperature range between room temperature and 450 °C. A bleaching experiment for two separated glow peaks (P3 and P4) using a solar simulator revealed that the bleaching rates of peak P3 show two exponential decays, and after bleaching, the TL intensity of peak P3 is reduced to approximately 4% of the initial value. In contrast, peak P4 is bleached exponentially to approximately 30% of the initial TL intensity and thereafter shows no detectable change in intensity. In addition, in a study of the radiation dose response of the two peaks, both peaks have a similar pattern, exhibiting a linear increment up to the maximum dose investigated, 520 Gy.

Kim, Ki-Bum; Hong, Duk-Geun

2014-10-01

158

Glow curve analysis applied to the discrimination of X ray versus proton irradiation.  

PubMed

Three types of thermoluminescence dosemeters (TLDs): LiF:Mg,Ti (TLD-100), CaF2:Tm (TLD-300), and alpha-Al2O3:C (TLD-500), were investigated for their glow curve response to separate X ray and proton irradiations. The glow curve structure for each individual TLD's exposure to the X ray and proton irradiations was analysed and compared. Distinguishable differences between the glow curve structure characteristic of each type of radiation were observed. The proton TLD-100 glow curve has revealed a complex high-temperature peak structure that was used for the proton/X ray discrimination algorithm. Proton irradiation of TLD-300 resulted in an apparent switch in the relative heights of peaks 3 and 5 as compared to X ray. In TLD-500, proton irradiation produced a more subtle difference in the glow curve with an increase in the ratio between high- and low-temperature peaks. Results demonstrate promising differences in glow curve structure present allowing for discrimination between X ray and proton radiation field exposures. PMID:12382714

Skopec, M; Price, J L; Guardala, N; Loew, M; Moscovitch, M

2002-01-01

159

Use of Atmospheric Glow Discharge Plasma to Modify Spaceport Materials  

NASA Technical Reports Server (NTRS)

Numerous materials used in spaceport operations require stringent evaluation before they can be utilized. It is critical for insulative polymeric materials that any surface charge be dissipated as rapidly as possible to avoid Electrostatic Discharges (ESD) that could present a danger. All materials must pass the Kennedy Space Center (KSC) standard electrostatic test [1]; however several materials that are considered favorable for Space Shuttle and International Space Station use have failed. Moreover, to minimize contamination of Mars spacecraft, spacecraft are assembled under cleanroom conditions and specific cleaning and sterilizing procedures are required for all materials. However, surface characteristics of these materials may allow microbes to survive by protecting them from sterilization and cleaning techniques. In this study, an Atmospheric Pressure Glow Discharge Plasma (APGD) [2] was used to modify the surface of several materials. This allowed the materials surface to be modified in terms of hydrophilicity, roughness, and conductivity without affecting the bulk properties. The objectives of this study were to alter the surface properties of polymers for improved electrostatic dissipation characteristics, and to determine whether the consequent surface modification on spaceport materials enhanced or diminished microbial survival.

Trigwell, S.; Shuerger, A. C.; Buhler, C. R.; Calle, C. J.

2006-01-01

160

Xenon doping of glow discharge polymer by ion implantation  

SciTech Connect

We demonstrate controlled doping of a glow discharge polymer by implantation with 500 keV Xe ions at room temperature. The Xe retention exhibits a threshold behavior, with a threshold dose of {approx}2 x 10{sup 14} cm{sup -2}. Doping is accompanied by irradiation-induced changes in the polymer composition, including gradual H loss and a more complex non-monotonic behavior of the O concentration. The matrix composition saturates at C{sub 0.77}H{sub 0.22}O{sub 0.01} for Xe doses above {approx}5 x 10{sup 14} cm{sup -2} and up to the maximum dose studied (5 x 10{sup 15} cm{sup -2}). The retention mechanism is attributed to the modification of the polymer from a chain-like to clustered ring structure. The dopant profile and the elemental composition of the implanted polymer exhibit good stability upon thermal annealing up to 305 deg. C.

Shin, Swanee J.; Kucheyev, Sergei O.; Orme, Christine A.; Hamza, Alex V. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Youngblood, Kelly P.; Nikroo, Abbas; Moreno, Kari A.; Chen, Bryan [General Atomics, San Diego, California 92186 (United States)

2012-05-01

161

Investigation of sheath phenomena in electronegative glow discharges  

NASA Astrophysics Data System (ADS)

Two different methods of analyzing the cathode fall region of low pressure glow discharges were developed and applied to three different electronegative gas mixtures. One method was based on a self-consistent numerical solution to Poisson's equation, the current continuity equations for electrons and negative ions, and the current conservation equation. This method assumes the electrons are always in equilibrium with the electric field. The other method was based on a self-consistent numerical solution of the Boltzmann transport equation for electrons, Poisson's equation, and the current conservation equation. This method allows the electrons not to be in equilibrium with the field. Comparing these two methods revealed that nonequilibrium prevails throughout the cathode fall region. The electronegative gas mixtures investigated were small concentrations (less that 10%) of hydrogen chloride in helium, argon, or xenon. The electric field, Townsend ionization and attachment coefficients, electron and negative ion current densities, and electron, positive ion, and negative ion number densities are plotted as functions of distance through the cathode fall region.

Duke, G. L.

1985-04-01

162

A MODULAR STEADY STATE GLOW DISCHARGE QUADRUPOLE MASS SPECTROMETER SYSTEM FOR THE AT-LINE ANALYSIS OF PLUTONIUM METAL  

SciTech Connect

Historically, glow discharge mass and optical spectrometric techniques have been used in industry for the characterization of processed metals, such as steels and other alloys. This technique is especially well suited for this type of product analysis because the glow discharge ionization source accommodates solid conducting samples with minimal or no sample preparation. This characteristic along with minimal matrix effect considerations makes the glow discharge source well suited for these types of applications.

R. STEINER; D. WAYNE

1998-12-01

163

Extraction of oxygen from the Mars atmosphere using glow-discharge and permeation techniques  

NASA Technical Reports Server (NTRS)

Oxygen can be extracted from carbon dioxide via thermal dissociation at elevated temperatures. However, temperatures in excess of 1000 K are needed to effect significant levels of dissociation. The experiments reported here have examined the feasibility of using a glow-discharge in low-pressure carbon dioxide to produce increased atomic oxygen yields at lower temperatures (on the order of 800 K). The experiments have shown that when silver membranes are used simultaneously as anodes for the glow discharge and as permeable membranes for oxygen separation, oxygen yields which are comparable to the permeation rates for pure oxygen, can be produced. Since the silver membrane can be employed as the electrode interface between Mars atmosphere and a stabilized-zirconia electrochemical pump, glow-discharge enhancement can be considered as a complementary technology which can be used with the zirconia-based oxygen extraction systems described previously by others. Not only can glow-discharge be used to increase oxygen yields at lowered temperatures, but it can also be considered as a possible way to avoid filtration and compression of Mars atmosphere, since the glow-discharge can be sustained in Mars ambient pressures.

Wu, Dongchuan; Ash, Robert; Outlaw, Ronald

1993-01-01

164

Experiments with Glow-in-the-Dark Toys: Kinetics of Doped ZnS Phosphorescence  

NASA Astrophysics Data System (ADS)

Many semiconductors exhibit the property of phosphorescence, the phenomenon whereby a material excited by visible or ultraviolet radiation glows (i.e., emits visible light) for a substantial time after the excitation source has been removed. One phosphorescent semiconductor commonly used in glow-in-the dark toys and emergency signs is copper-doped zinc sulfide (ZnS:Cu), a material that produces a yellow-green glow. The study of this light emission is a suitable introduction to kinetics and to semiconductors. Intensity data were recorded for a Glow-Yo yo-yo, an Amazing Glow Ball, Hanovia P-1000 pigment, and Glo-Vinyl Tape by spectrofluorophotometer and also by using a CdS photocell and ohmmeter. The emission of the ZnS semiconductor is not across the band gap, but involves interband traps associated with the Cu doping material. The phosphorescence decay of ZnS:Cu fits a second order equation, consistent with recombination of relatively equal populations of holes and electrons (n ~ p). Arrhenius data show the delocalized electrons in the conduction band must overcome a small but measurable activation energy of about 15 kJ/mol to fall back to the localized copper-site holes for the recombination that produces phosphorescence.

Lisensky, George C.; Patel, Manish N.; Reich, Megan L.

1996-11-01

165

Practical sensor for nitrogen in direct current glow discharges  

SciTech Connect

This paper presents a method for precise measurement of atomic and molecular nitrogen in an oxygen-nitrogen dc plasma. This is achieved by monitoring the intensities of the atomic nitrogen spectral line at 821.6 nm and the molecular nitrogen bandhead at 337.1 nm, relative to the atomic oxygen spectral line at 844.7 nm. Oxygen is one of the most frequently used gases for surface chemical treatment, including deposition and etching, therefore the ability to measure and control the process and chemical composition of the process is essential. To validate this oxygen actimometry method for N{sub 2}-xO{sub 2} (where x varies from 0 to 1) dc plasmas, threshold tests have been performed with Ar actinometry. The optical measurements have been performed using two methods. The first approach uses a USB2000 fiber optic spectrometer, calibrated with a Gigahertz-Optik BN-0102-1 reference standard source, to record the desired spectral lines. The second approach uses narrow bandwidth optical filters ({approx}0.7-0.07 nm) with central wavelengths of 821.6, 337.1, and 844.69 nm and photodiodes to detect the emission intensity, also calibrated with the same standard source. Optical data are collected for a range of experimental conditions in a flowing glow discharge of N{sub 2}-xO{sub 2} mixture. The maximum dc voltage is 2.2 kV and maximum chamber pressure is 266 Pa. Data from both optical methods are compared and used to interpret the relative atomic and molecular nitrogen concentrations under various operating conditions.

Popovic, D.; Milosavljevic, V.; Daniels, S. [Faculty of Physics, University of Belgrade, P. O. Box 368, Belgrade (Serbia); Faculty of Physics, University of Belgrade, P. O. Box 368, Belgrade (Serbia) and NCPST and School of Physics, Dublin City University, Dublin 9 (Ireland); NCPST and School of Electronic Engineering, Dublin City University, Dublin 9 (Ireland)

2007-11-15

166

Immune abnormalities in myelodysplastic syndromes.  

PubMed Central

The immune states of 52 patients with myelodysplastic syndromes classified according to the FAB criteria were studied. Serum electrophoresis and immunoelectrophoresis, direct Coombs test, and tests for organ and non-organ specific antibodies were performed. Twenty six patients had immunoglobulin abnormalities: six (11.5%) had monoclonal gammopathy; 17 (32.6%) had polyclonal increases in serum immunoglobulin; while in three (5.8%) immunoglobulin concentrations were decreased. The distribution of immunoglobulin abnormalities among the five myelodysplastic syndrome subtypes was fairly uniform. Results of direct Coombs test were negative in all cases. Organ specific antibodies were not detected in any of the patients tested, although two patients were found positive for antinuclear antibodies. The presence of immunoglobulin abnormalities indicates an involvement of the lymphoplasmatic system in myelodysplastic syndromes. PMID:3928701

Economopoulos, T; Economidou, J; Giannopoulos, G; Terzoglou, C; Papageorgiou, E; Dervenoulas, J; Arseni, P; Hadjioannou, J; Raptis, S

1985-01-01

167

Abnormal waves during Hurricane Camille  

NASA Astrophysics Data System (ADS)

A reanalysis is reported of the wave time series recorded during Hurricane Camille having as objective the identification of individual waves that satisfy current criteria defining abnormal or freak waves. It is shown that during the hurricane development, a very nonstationary situation has occurred during which the second-order sea state parameters changed significantly with time. The parameters of the largest individual waves in sea states which identify abnormal waves did not show any clear trend, and such waves occurred during the development stage and not when the significant wave height was the largest. It is argued that the present criteria of identification of abnormal waves are not satisfactory, as they do not take into account the nature of the sea states in which the waves occur.

Guedes Soares, C.; Cherneva, Z.; AntãO, E. M.

2004-08-01

168

Complex patterns of abnormal heartbeats  

NASA Astrophysics Data System (ADS)

Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical ``heartprints'' which reveal characteristic patterns in long clinical records encompassing ~105 heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch.; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

2002-09-01

169

Complex patterns of abnormal heartbeats  

NASA Technical Reports Server (NTRS)

Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

2002-01-01

170

[Hematological abnormalities in rheumatic diseases].  

PubMed

Haematological abnormalities are present in 25-50% patients with rheumatic diseases. The most common finding is anaemia of chronic disease which is driven by inflammatory cytokines. Hepcidin plays key role in iron homeostasis. It reduces iron absorption from duodenum and iron release from reticuloendothelial cells. Anaemia of chronic disease could be successfully treated by recombinant erythropoietin in combination with iron supplementation. Various abnormalities can be observed in the leukocyte and platelets counts. Other haematological disturbances are considered as part of autoimmune disease. Prolonged antigen stimulation can induce lymphomagenesis and lymphoma incidence in patients with rheumatic diseases is 5 to 6-fold increased compared to normal population. PMID:17580549

Radman, Ivo

2006-01-01

171

O2 and CO2 glow-discharge-assisted oxygen transport through Ag  

NASA Technical Reports Server (NTRS)

Experiments were conducted to determine whether dissociative adsorption is a possible limitation of the oxygen permeability through Ag, using the upstream glow-discharge dissociation of O2 and CO2 to provide a gas phase source of atomic oxygen. Results suggest that the dissociative adsorption step limits the supply of oxygen atoms to the upstream side of the membrane. When the upstream O2 was replaced by an equal pressure of CO2 in absence of glow discharge, only a small permeation signal was observed; the application of the glow discharge increasded the oxygen transport flux from 3.25 x 10 to the 12th/sq cm per sec to 1.74 x 10 to the 14th/sq cm per sec. It is suggested that this method of separating O2 from a CO2-rich atmosphere may be considered for providing oxygen for the astronauts in a manned expedition to Mars.

Outlaw, R. A.

1990-01-01

172

Self-Consistent Model for Pulsed Direct-Current N2 Glow Discharge  

NASA Astrophysics Data System (ADS)

A self-consistent analysis of a pulsed direct-current (DC) N2 glow discharge is presented. The model is based on a numerical solution of the continuity equations for electron and ions coupled with Poisson's equation. The spatial-temporal variations of ionic and electronic densities and electric field are obtained. The electric field structure exhibits all the characteristic regions of a typical glow discharge (the cathode fall, the negative glow, and the positive column). Current-voltage characteristics of the discharge can be obtained from the model. The calculated current-voltage results using a constant secondary electron emission coefficient for the gas pressure 133.32 Pa are in reasonable agreement with experiment.

Liu, Chengsen; Wang, Dezhen

2005-04-01

173

Tropospheric Wind Measurements Obtained with the Goddard Lidar Observatory for Winds (GLOW): Validation and Performance  

NASA Technical Reports Server (NTRS)

The Goddard Lidar Observatory for Winds (GLOW) is a mobile Doppler lidar system which uses direct detection Doppler lidar techniques to measure wind profiles from the surface into the lower stratosphere. GLOW is intended to be used as a field deployable system for studying atmospheric dynamics and transport and can also serve as a testbed to evaluate candidate technologies developed for use in future spaceborne systems. In September of 2000 GLOW participated in a three week intercomparison experiment at the GroundWinds facility in North Glen, NH. More than 50 hours of line-of-sight wind profile data were obtained in a wide variety of conditions including both day and night operation. Typical clear air lidar wind profiles extended to altitudes of 20 kin with a 1 km vertical resolution and 1 minute averaging. A description of the mobile system is presented along with the examples of lidar wind profiles obtained with the Goddard system during the New Hampshire experiment.

Gentry, Bruce M.; Chen, Huai-Lin; Einaudi, Franco (Technical Monitor)

2001-01-01

174

Tropospheric Wind Measurements Obtained with the Goddard Lidar Observatory for Winds (GLOW): Validation and Performance  

NASA Technical Reports Server (NTRS)

The Goddard Lidar Observatory for Winds (GLOW) is a mobile Doppler lidar system which uses direct detection Doppler lidar techniques to measure wind profiles from the surface into the lower stratosphere. GLOW is intended to be used as a field deployable system for studying atmospheric dynamics and transport and can also serve as a testbed to evaluate candidate technologies developed for use in future spaceborne systems. In September of 2000 GLOW participated in a three week intercomparison experiment at the GroundWinds facility in North Glen, NE. More than 50 hours of line-of-sight wind profile data was obtained in a wide variety of conditions including both day and night operation. Typical clear air lidar wind profiles extended to altitudes of 20 km with a 1 Ian vertical resolution and I minute averaging. A description of the mobile system is presented along with the examples of lidar wind profiles obtained with the Goddard system during the New Hampshire experiment.

Gentry, Bruce M.; Einaudi, Franco (Technical Monitor)

2001-01-01

175

Binary and ternary gas mixtures with temperature enhanced diffuse glow discharge characteristics for use in closing switches  

DOEpatents

An improvement to the gas mixture used in diffuse glow discharge closing switches is disclosed which includes binary and ternary gas mixtures which are formulated to exhibit decreasing electron attachment with increasing temperature. This increases the efficiency of the conductance of the glow discharge and further inhibits the formation of an arc. 11 figs.

Christophorou, L.G.; Hunter, S.R.

1988-06-28

176

A study of glow-discharge and permeation techniques for extraterrestrial oxygen beneficiation  

NASA Technical Reports Server (NTRS)

Extraction of oxygen from Martian atmosphere and compression of lunar oxygen can utilize stabilized zirconia electrochemical pumps. Silver membranes can be used as electrodes to increase oxygen yield at relatively low temperatures. This study has investigated oxygen permeation through Ag 0.05Zr membranes with glow-discharge assisted disassociation. Data show that the overall process is controlled by bulk diffusion but the slow dissociative adsorption onto the surface limited the overall transport substantially. With glow-discharge assisted dissociation, an order of magnitude increase in oxygen throughput can be produced at relatively low temperatures (450-550C).

Ash, R. L.; Wu, D.; Outlaw, R. A.

1994-01-01

177

An experimental study on discharge mechanism of pulsed atmospheric pressure glow discharges  

SciTech Connect

The discharge mechanism of pulsed atmospheric pressure glow discharges excited by the unipolar positive voltage pulses between two parallel plate electrodes with or without one dielectric barrier on the ground electrode in flowing helium has been characterized by nanosecond time resolved optical and electrical measurements. The uniform glow discharges can only be achieved when the voltage pulse duration is less than 1 {mu}s with bare electrodes. With introducing a dielectric barrier on the ground electrode, a model of electrons traveling on the background ions between two discharge events is proposed to explain the discharge mechanism and characteristics in terms of discharge ignition, discharge spatial profile and discharge current amplitude.

Huang Xiaojiang; Bao Yun [College of Science, Donghua University, Shanghai 201620 (China); Member of Magnetic Confinement Fusion Research Center, Ministry of Education of the People's Republic of China, Shanghai 201620 (China); Sun Liqun [College of Science, Donghua University, Shanghai 201620 (China); Zhang Jing; Shi, J. J. [College of Science, Donghua University, Shanghai 201620 (China); State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Member of Magnetic Confinement Fusion Research Center, Ministry of Education of the People's Republic of China, Shanghai 201620 (China)

2011-03-15

178

Binary and ternary gas mixtures for use in glow discharge closing switches  

DOEpatents

Highly efficient binary and ternary gas mixtures for use in diffuse glow discharge closing switches are disclosed. The binary mixtures are combinations of helium or neon and selected perfluorides. The ternary mixtures are combinations of helium, neon, or argon, a selected perfluoride, and a small amount of gas that exhibits enhanced ionization characteristics. These mixtures are shown to be the optimum choices for use in diffuse glow discharge closing switches by virtue if the combines physio-electric properties of the mixture components. 9 figs.

Hunter, S.R.; Christophorou, L.G.

1988-04-27

179

Thermoluminescence response and glow curve structure of Sc?TiO? ß-irradiated.  

PubMed

Discandium titanate (Sc2TiO5) powder was synthesized in order to analyze its thermoluminescence (TL) response. The TL glow curve structure shows two peaks: at 453-433 K and at 590-553 K. The TL beta dose-response has a linear behavior over the dose range 50-500 Gy. The T(stop) preheat method shows five glow peaks that were taken into account to calculate the kinetic parameters using the CGCD procedure. TL results support the possible use of Sc2TiO5 as a new phosphor in high ß-dose dosimetry. PMID:24698777

Muñoz, I C; Brown, F; Durán-Muñoz, H; Cruz-Zaragoza, E; Durán-Torres, B; Alvarez-Montaño, V E

2014-08-01

180

Abnormal Psychology, Spring 2008 1 Psychology 350  

E-print Network

Abnormal Psychology, Spring 2008 1 Psychology 350 Abnormal Psychology Spring 2008 N-101 Tuesdays 4 psychology. By the end of the semester, students will be able to: · Discuss extant models of abnormal in Foundation II.B., Social and Behavioral Sciences required." #12;Abnormal Psychology, Spring 2008 2 Course

Gallo, Linda C.

181

Abnormalities of human sex determination  

Microsoft Academic Search

Summary Cytogenetic and molecular studies in patients with abnormalities of sex determination have been the key to the isolation and investigation of candidates for the primary testis determining factor (TDF). A gene, SRY, isolated from the sex determining region of the Y chromosome within 5 kilobases of the pairing segment boundary, has been characterized recently which fulfils the expectations of

M. A. Ferguson-Smith

1992-01-01

182

Steganography with Least Histogram Abnormality  

Microsoft Academic Search

A novel steganographic scheme is proposed which avoids asymmetry inherent in conventional LSB embedding techniques so that abnormality in the image histogram is kept minimum. The proposed technique is capable of re- sisting the ?2 test and RS analysis, as well as a new steganalytic method named GPC analysis as introduced in this paper. In the described steganographic tech- nique,

Xinpeng Zhang; Shuozhong Wang; Kaiwen Zhang

2003-01-01

183

Extracellular Matrix Abnormalities in Schizophrenia  

PubMed Central

Emerging evidence points to the involvement of the brain extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Abnormalities affecting several ECM components, including Reelin and chondroitin sulfate proteoglycans (CSPGs), have been described in subjects with this disease. Solid evidence supports the involvement of Reelin, an ECM glycoprotein involved in corticogenesis, synaptic functions and glutamate NMDA receptor regulation, expressed prevalently in distinct populations of GABAergic neurons, which secrete it into the ECM. Marked changes of Reelin expression in SZ have typically been reported in association with GABA-related abnormalities in subjects with SZ and bipolar disorder. Recent findings from our group point to substantial abnormalities affecting CSPGs, a main ECM component, in the amygdala and entorhinal cortex of subjects with schizophrenia, but not bipolar disorder. Striking increases of glial cells expressing CSPGs were accompanied by reductions of perineuronal nets, CSPG- and Reelin-enriched ECM aggregates enveloping distinct neuronal populations. CSPGs developmental and adult functions, including neuronal migration, axon guidance, synaptic and neurotransmission regulation are highly relevant to the pathophysiology of SZ. Together with reports of anomalies affecting several other ECM components, these findings point to the ECM as a key component of the pathology of SZ. We propose that ECM abnormalities may contribute to several aspects of the pathophysiology of this disease, including disrupted connectivity and neuronal migration, synaptic anomalies and altered GABAergic, glutamatergic and dopaminergic neurotransmission. PMID:21856318

Berretta, Sabina

2011-01-01

184

Generation of Atmospheric-Pressure Glow Discharge and Its Applications 3.Applications of Atmospheric-Pressure Glow Plasma 3.1 Surface Treatment of Organic Materials  

NASA Astrophysics Data System (ADS)

Surface treatments of organic materials such as wool fabric and polymer films were done by glow plasma in two types of discharge systems at atmospheric pressure using He and Ar as carrier gases.Wool fabric was treated by C3F6/He plasma using a parallel plate-type reactor. On the fabric surface, fluorinated polymer was deposited. The surface has a high value of oil contact angle, so it retained anti-shrinking effect of wool fabrics even after repeated washing in water. Surface cleaning of organic contamination on a silicon wafer was done by after glow plasma in an atmospheric ambience using a new spray-type discharge reactor. Ashing (cleaning) rate was strongly dependent on the gas flow rate of O2/Ar gas and on the concentration of O2.

Kogoma, Masuhiro

185

Generation of Atmospheric-Pressure Glow Discharge and Its Applications 3.Applications of Atmospheric-Pressure Glow Plasma 3.1 Surface Treatment of Organic Materials  

Microsoft Academic Search

Surface treatments of organic materials such as wool fabric and polymer films were done by glow plasma in two types of discharge systems at atmospheric pressure using He and Ar as carrier gases.Wool fabric was treated by C3F6\\/He plasma using a parallel plate-type reactor. On the fabric surface, fluorinated polymer was deposited. The surface has a high value of oil

Masuhiro Kogoma

2003-01-01

186

The Rose-red Glow of Star Formation  

NASA Astrophysics Data System (ADS)

The vivid red cloud in this new image from ESO's Very Large Telescope is a region of glowing hydrogen surrounding the star cluster NGC 371. This stellar nursery lies in our neighbouring galaxy, the Small Magellanic Cloud. The object dominating this image may resemble a pool of spilled blood, but rather than being associated with death, such regions of ionised hydrogen - known as HII regions - are sites of creation with high rates of recent star birth. NGC 371 is an example of this; it is an open cluster surrounded by a nebula. The stars in open clusters all originate from the same diffuse HII region, and over time the majority of the hydrogen is used up by star formation, leaving behind a shell of hydrogen such as the one in this image, along with a cluster of hot young stars. The host galaxy to NGC 371, the Small Magellanic Cloud, is a dwarf galaxy a mere 200 000 light-years away, which makes it one of the closest galaxies to the Milky Way. In addition, the Small Magellanic Cloud contains stars at all stages of their evolution; from the highly luminous young stars found in NGC 371 to supernova remnants of dead stars. These energetic youngsters emit copious amounts of ultraviolet radiation causing surrounding gas, such as leftover hydrogen from their parent nebula, to light up with a colourful glow that extends for hundreds of light-years in every direction. The phenomenon is depicted beautifully in this image, taken using the FORS1 instrument on ESO's Very Large Telescope (VLT). Open clusters are by no means rare; there are numerous fine examples in our own Milky Way. However, NGC 371 is of particular interest due to the unexpectedly large number of variable stars it contains. These are stars that change in brightness over time. A particularly interesting type of variable star, known as slowly pulsating B stars, can also be used to study the interior of stars through asteroseismology [1], and several of these have been confirmed in this cluster. Variable stars play a pivotal role in astronomy: some types are invaluable for determining distances to far-off galaxies and the age of the Universe. The data for this image were selected from the ESO archive by Manu Mejias as part of the Hidden Treasures competition [2]. Three of Manu's images made the top twenty; his picture of NGC 371 was ranked sixth in the competition. Notes [1] Asteroseismology is the study of the internal structure of pulsating stars by looking at the different frequencies at which they oscillate. This is a similar approach to the study of the structure of the Earth by looking at earthquakes and how their oscillations travel through the interior of the planet. [2] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. Participants submitted nearly 100 entries and ten skilled people were awarded some extremely attractive prizes, including an all expenses paid trip for the overall winner to ESO's Very Large Telescope (VLT) on Cerro Paranal, in Chile, the world's most advanced optical telescope. The ten winners submitted a total of 20 images that were ranked as the highest entries in the competition out of the near 100 images. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO op

2011-03-01

187

The Blue Glow from the Back Row: Live Theater and the Wireless Teen  

ERIC Educational Resources Information Center

Every year the author and his colleagues take their grade 12 English students to see four plays at one of Canada's major theaters. Chatting about the series on the last day of class, his students asked him if he had seen "the blue glow from the back row." Laughing at his bewilderment, they told him that during the performances so many students…

Richardson, John M.

2012-01-01

188

Spatial distribution and accumulation of radicals arising in organic solids under the action of glow discharge  

Microsoft Academic Search

The method, based on analyzing the dipolar broadening of EPR spectra was applied for investigation of the spatial distribution of radicals generated by high-frequency glow discharge in organic molecular crystals (powders of malonic and dimethylmalonic acids) and glassy isopropanol contained electron scavenger. It was shown that in the first case the radical distribution does not depend on time of discharge.

A. M. Raitsimring; V. V. Kurshev

1994-01-01

189

Surface modification of cotton yarn with a DC glow discharge in ambient air  

Microsoft Academic Search

A direct-current atmospheric pressure glow discharge is used for surface treatment of cotton yarn. The envisaged plasma effect is an increase in the surface energy of the treated material, leading e.g. towards a better wettability, adhesion or dyeability. The electrode geometry is that of a negative corona with a plane anode and a cathode that consists of a single row

Eef Temmerman; Christophe Leys

2005-01-01

190

High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry  

SciTech Connect

The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

McLuckey, S.A.; Goeringer, D.E.; Asano, K.G. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

1996-02-01

191

Volume 2. number 7 CHEMICAL PHYSICS LETTERS November 1968 CALCULATION OF GLOW CURVES' ACTIVATION ENERGIES  

E-print Network

for the calculation of activation energies by the Ynitial rise Rportion of glow curves is given. The method is shown of finding the activation energy of a trap by using the "initial rise" range of thermoluminescence (TL A is a constant, E the activation energy, T the absolute temperature and k the Boltzmann constant. By plotting

Chen, Reuven

192

Utilizing a one-atmosphere uniform glow discharge plasma for chemical\\/biological warfare agent decontamination  

Microsoft Academic Search

Summary form only given, as follows. An innovative approach to the decontamination of chemical and\\/or biological warfare agents is described. This recently developed technology involves utilizing a one atmosphere uniform glow discharge plasma (OAUGDP) as the decontaminant\\/sterilant. The plasma provides a very powerful but environmentally safe oxidizing and disinfecting technique without the use of strong chemicals (chlorine bleach) or high

M. R. McLean; J. R. Roth

1998-01-01

193

Acoustic Shock Wave Propagation in a Glow Discharge(Supported by Accurate Automation Corporation.)  

Microsoft Academic Search

Experiments with weak acoustic shock waves propagating through glow discharges(A. I. Klimov et al., Sov. Tech Phys. Lett. 8), 192 (1982).^,(B. N. Ganguly et al., Phys. Lett. A 230), 218 (1997). have shown unexpected damping, dispersion, and propagation effects that still remain to be understood. Similar effects were observed for both monoatomic and molecular gas discharges. Increase of shock velocity

S. Popovic; L. Vuskovic

1999-01-01

194

Discrimination of photon from proton irradiation using glow curve feature extraction and vector analysis.  

PubMed

Two types of thermoluminescence dosemeters (TLDs), the Harshaw LiF:Mg,Ti (TLD-100) and CaF(2):Tm (TLD-300) were investigated for their glow curve response to separate photon and proton irradiations. The TLDs were exposed to gamma irradiation from a (137)Cs source and proton irradiation using a positive ion accelerator. The glow curve peak structure for each individual TLD exposure was deconvolved to obtain peak height, width, and position. Simulated mixed-field glow curves were obtained by superposition of the experimentally obtained single field exposures. Feature vectors were composed of two kinds of features: those from deconvolution and those taken in the neighbourhood of several glow curve peaks. The inner product of the feature vectors was used to discriminate among the pure photon, pure proton and simulated mixed-field irradiations. In the pure cases, identification of radiation types is both straightforward and effective. Mixed-field discrimination did not succeed using deconvolution features, but the peak-neighbourhood features proved to discriminate reliably. PMID:16614091

Skopec, M; Loew, M; Price, J L; Guardala, N; Moscovitch, M

2006-01-01

195

Glow Discharge Characteristics in Relation to Anode Size in Inertial Electrostatic Confinement Fusion  

Microsoft Academic Search

An Inertial Electrostatic Confinement Fusion device is a very simple and safe neutron source that uses a glow discharge for deuterium-deuterium fusion. The discharge characteristics of the device were studied experimentally. The relationship between gas pressure and applied voltage was examined by light changes of the device's anode size. The gas pressure ranges in which the device was able to

Hodaka Osawa; Shigehisa Yoshimura; Takehiro Tabata; Masami Ohnishi

2008-01-01

196

Numerical curve fitting for calculating glow N. S . MOHAN and R. CHENT  

E-print Network

. Cowell and Woods (1967) suggested a graphical method of curve fitting for finding activation energies activationenergies. Besidesusingthe numerical curvefitting method for glow peaks of first-order kinetics, the method is extended to the case of second-order thermoluminescenceor thermally stimulatedcurrent peaks. The method

Chen, Reuven

197

Period doubling cascade in glow discharges: Local versus global differential conductivity Danijela D. Sijaci,1  

E-print Network

, The Netherlands 2 Department of Physics, Eindhoven University of Technology, The Netherlands 3 American University and energy saving lamps, beamers, flat TV screens, car and street lamps, as well as in various industrial structures. An interesting series of experiments has been per- formed on such glow discharges with wide

Ebert, Ute

198

Plasma Processing with a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP)  

NASA Astrophysics Data System (ADS)

The vast majority of all industrial plasma processing is conducted with glow discharges at pressures below 10 torr. This has limited applications to high value workpieces as a result of the large capital cost of vacuum systems and the production constraints of batch processing. It has long been recognized that glow discharges would play a much larger industrial role if they could be operated at one atmosphere. The One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has been developed at the University of Tennessee Plasma Sciences Laboratory. The OAUGDP is non-thermal RF plasma with the time-resolved characteristics of a classical low pressure DC normal glow discharge. An interdisciplinary team was formed to conduct exploratory investigations of the physics and applications of the OAUGDP. This team includes collaborators from the UTK Textiles and Nonwovens Development Center (TANDEC) and the Departments of Electrical and Computer Engineering, Microbiology, Food Science and Technology, and Mechanical and Aerospace Engineering and Engineering Science. Exploratory tests were conducted on a variety of potential plasma processing and other applications. These include the use of OAUGDP to sterilize medical and dental equipment and air filters; diesel soot removal; plasma aerodynamic effects; electrohydrodynamic (EDH) flow control of the neutral working gas; increasing the surface energy of materials; increasing the wettability and wickability of fabrics; and plasma deposition and directional etching. A general overview of these topics will be presented.

Reece Roth, J.

2000-10-01

199

Force interaction of high pressure glow discharge with fluid flow for active separation control  

E-print Network

discharge DBD at high pressure to inhibit phenomena such as stall on airfoils, thus improving their liftForce interaction of high pressure glow discharge with fluid flow for active separation control modeling to lift limitations in the current understanding of the actuation mechanism. The present effort

Roy, Subrata

200

EFFECTS OF GLOW DISCHARGE WITH HYDROGEN ISOTOPE PLASMAS ON RADIOACTIVITY OF URANIUM  

Microsoft Academic Search

Uranium foils were attached to the cathode of a glow discharge apparatus. A plasma of either hydrogen or deuterium ions was used to bombard the uranium. The rates of alpha, beta, and gamma radiation emissions were significantly greater for the bombarded uranium than for the original material.

J. Dash; I. Savvatimova; S. Frantz; E. Weis; H. Kozima

201

Mechanical and Tribological Properties of LDX2101 Duplex Stainless Steel Submitted to Glow Discharge Ion Nitriding  

Microsoft Academic Search

In this paper, the mechanical and tribological proper- ties of LDX2101 duplex stainless steel submitted to glow discharge (GD) nitriding and conventional ion beam nitrogen implanta- tion (II) are reported. Different combinations of rich and poor nitrogen\\/hydrogen atmospheres and working GD temperatures are employed. Nitrogen II at room temperature and 350 ? Cw as performed at different energies and fluences

Andre Assmann; Carlos Eugenio Foerster; Francisco Carlos Serbena; Carlos Mauricio Lepienski; Adilson Luis Chinelatto

2011-01-01

202

Characterization of a Direct-Current Glow Discharge Plasma Actuator in Low-Pressure Supersonic Flow  

E-print Network

densities (1 A=m2 ) [9­11]. DBD discharges generate low (room) temperature plasmas and rely on the EHD on the generation of a Lorentz force on the bulk flow owing to the interaction of electrical currentsCharacterization of a Direct-Current Glow Discharge Plasma Actuator in Low-Pressure Supersonic Flow

Raja, Laxminarayan L.

203

On the accuracy and limitations of fluid models of the cathode region of dc glow discharges  

Microsoft Academic Search

This paper compares the performance and limitations of different models of the cathode region of cold-cathode low-pressure dc glow discharges: (i) we review known modelling approaches, (ii) develop our own simulation codes based on these approaches, (iii) perform calculations using these codes for reference sets of discharge conditions, which allows a critical comparison of the models and (iv) for a

A. Derzsi; P. Hartmann; I. Korolov; J. Karácsony; G. Bánó; Z. Donkó

2009-01-01

204

Glow Discharge Source Atomization for the Laser-Excited Atomic Fluorescence Spectrometric Studies of Indium.  

National Technical Information Service (NTIS)

A demountable glow discharge source has been used for the atomization of the analyte solutions deposited on graphite and copper rod cathodes. Indium atoms are sputtered-atomized from the cathode surface and are excited by a pulsed, frequency-doubled dye l...

B. M. Patel, J. D. Winefordner

1986-01-01

205

A glow discharge device for atomic emission spectrometry of microliter solution samples  

NASA Astrophysics Data System (ADS)

A novel glow discharge device designed specifically for solution analysis is described. The detection limits obtained are comparable to those obtained with demountable hollow cathode lamps, but with better precision. Rotational and excitation temperatures are examined as functions of fill gas pressure and discharge current. A sputtering constant is presented and the technique for measuring this parameter is described.

Brackett, J. M.; Vickers, T. J.

206

Self-Consistent Kinetic Model of the Cathode Fall of a Glow Discharge.  

National Technical Information Service (NTIS)

The electrons in the cathode-fall (CF) region of a helium dc glow discharge have been modeled at the kinetic level with a self-consistent electric field using a convective scheme (CS) (propagator or Green's-function) solution method. The CS is both straig...

T. J. Sommerer, W. N. Hitchon, J. E. Lawler

1989-01-01

207

Effects of Cloud on Goddard Lidar Observatory for Wind (GLOW) Performance and Analysis of Associated Errors  

Microsoft Academic Search

The Goddard Lidar Observatory for Wind (GLOW), a mobile direct detection Doppler LIDAR based on molecular backscattering for measurement of wind in the troposphere and lower stratosphere region of atmosphere is operated and its errors characterized. It was operated at Howard University Beltsville Center for Climate Observation System (BCCOS) side by side with other operating instruments: the NASA\\/Langely Research Center

Tulu Bacha

2011-01-01

208

Endotoxin removal by radio frequency gas plasma (glow discharge)  

NASA Astrophysics Data System (ADS)

Contaminants remaining on implantable medical devices, even following sterilization, include dangerous fever-causing residues of the outer lipopolysaccharide-rich membranes of Gram-negative bacteria such as the common gut microorganism E. coli. The conventional method for endotoxin removal is by Food & Drug Administration (FDA)-recommended dry-heat depyrogenation at 250°C for at least 45 minutes, an excessively time-consuming high-temperature technique not suitable for low-melting or heat-distortable biomaterials. This investigation evaluated the mechanism by which E. coli endotoxin contamination can be eliminated from surfaces during ambient temperature single 3-minute to cumulative 15-minute exposures to radio-frequency glow discharge (RFGD)-generated residual room air plasmas activated at 0.1-0.2 torr in a 35MHz electrodeless chamber. The main analytical technique for retained pyrogenic bio-activity was the Kinetic Chromogenic Limulus Amebocyte Lysate (LAL) Assay, sufficiently sensitive to document compliance with FDA-required Endotoxin Unit (EU) titers less than 20 EU per medical device by optical detection of enzymatic color development corresponding to < 0.5 EU/ml in sterile water extracts of each device. The main analytical technique for identification of chemical compositions, amounts, and changes during sequential reference Endotoxin additions and subsequent RFGD-treatment removals from infrared (IR)-transparent germanium (Ge) prisms was Multiple Attenuated Internal Reflection (MAIR) infrared spectroscopy sensitive to even monolayer amounts of retained bio-contaminant. KimaxRTM 60 mm x 15 mm and 50mm x 15mm laboratory glass dishes and germanium internal reflection prisms were inoculated with E. coli bacterial endotoxin water suspensions at increments of 0.005, 0.05, 0.5, and 5 EU, and characterized by MAIR-IR spectroscopy of the dried residues on the Ge prisms and LAL Assay of sterile water extracts from both glass and Ge specimens. The Ge prism MAIR-IR measurements were repeated after employing 3-minute RFGD treatments sequentially for more than 10 cycles to observe removal of deposited matter that correlated with diminished EU titers. The results showed that 5 cycles, for a total exposure time of 15 minutes to low-temperature gas plasma, was sufficient to reduce endotoxin titers to below 0.05 EU/ml, and correlated with concurrent reduction of major endotoxin reference standard absorption bands at 3391 cm-1, 2887 cm-1, 1646 cm -1 1342 cm-1, and 1103 cm-1 to less than 0.05 Absorbance Units. Band depletion varied from 15% to 40% per 3-minute cycle of RFGD exposure, based on peak-to-peak analyses. In some cases, 100% of all applied biomass was removed within 5 sequential 3-minute RFGD cycles. The lipid ester absorption band expected at 1725 cm-1 was not detectable until after the first RFGD cycle, suggesting an unmasking of the actual bacterial endotoxin membrane induced within the gas plasma environment. Future work must determine the applicability of this low-temperature, quick depyrogenation process to medical devices of more complicated geometry than the flat surfaces tested here.

Poon, Angela

209

Glow in the dark cats may lead to important advances in finding a cure for HIV  

NSDL National Science Digital Library

Cats That Glow For AIDS Research Join List of Animals That Shinehttp://www.npr.org/blogs/thetwo-way/2011/09/14/140465088/cats-that-glow-for-aids-research-join-list-of-animals-that-shine'Green-Glowing' Cats May Help to Fight Against HIV/AIDShttp://www.ibtimes.com/articles/213108/20110913/glowing-cats-mayo-clinic-japan-hiv-aids.htmThe Scientist: Fluorescent Cats Aid Researchhttp://the-scientist.com/2011/09/13/fluorescent-cats-aid-research/Glowing Animals: Pictures of Beasts Shining For Sciencehttp://news.nationalgeographic.com/news/2009/05/photogalleries/glowing-animal-picturesInternational Society for Transgenic Technologieshttp://www.transtechsociety.org/The Nobel Prize in Chemistry 2008http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2008/"Glow in the dark" animals have been around for a few years, but scientists at the Mayo Clinic in Minnesota and Yamaguchi University in Japan have come up with a rather curious use for such creatures. This week, researchers at these two institutions announced that they had genetically modified cats to glow in the dark. The cats were created by using a virus to carry a gene, called green fluorescent protein, into the eggs from which these animals eventually grew. It is hoped that this type of genetic modification will allow scholars to learn about vital clues for treating the AIDS virus. The idea is that scientists will now be able to monitor the activity of individual genes or cells in cats, and eventually in a number of different animals. This type of genetic modification expresses fluoresces when illuminated with UV light, which produces a green glow that scientists use to track the activity of individual genes or cells. Commenting on the work he shared with his colleagues, Eric Poeschla of the Mayo Clinic remarked, "One of the best things about this biomedical research is that it is aimed at benefiting both human and feline health." The first link will take visitors to a post from this Wednesday's NPR blog "The Two Way" about this recent discovery. The second link leads to an article from this Tuesday's International Business Times which offers some more details about the world of "green" cats. Moving along, the third link will take visitors to "The Nutshell" column from The Scientist website which also delves into fluorescence, kittens, and genetic modification. The fourth link will whisk users away to an interesting photographic feature on animals that have glowed in the name of science, courtesy of the folks at National Geographic. The fifth link leads to the homepage for the International Society for Transgenic Technologies (ISTT). Here visitors can learn about courses like "Genetics of Laboratory Rodents" and also view professional information about the ISTT and their activities. The last link will take interested parties to the official Nobel Prize page for the individuals who won the prize in 2008. They received the prize for developing the technique used by the researchers working on these cats, and the technique is now widely used throughout the world.

Grinnell, Max

2011-09-16

210

Tropospheric Wind Profiles Obtained with the GLOW Molecular Doppler Lidar during the 2002 International H2O Project  

NASA Technical Reports Server (NTRS)

The Goddard Lidar Observatory for Winds (GLOW) is a mobile direct detection Doppler lidar system which uses the double edge technique to measure the Doppler shift of the molecular backscattered laser signal at a wavelength of 355 nm. In the spring of 2002 GLOW was deployed to the western Oklahoma profiling site (36 deg 33.500 min N, 100 deg 36.371 min W) to participate in the International H2O Project (IHOP). During the IHOP campaign over 240 hours of wind profiles were obtained with the GLOW lidar in support of a variety of scientific investigations.

Gentry, Bruce M.; Chen, Huai-Lin; Li, Steven X.; Mathur, S.; Dobler, Jeremy; Hasselbrack, William

2003-01-01

211

Symphalangism with metacarpophalangeal fusions and elbow abnormalities  

Microsoft Academic Search

Three generations of a family manifest similar skeletal abnormalities: proximal symphalangism with several unusual features, metacarpophalangeal synostoses, massive tarsal and carpal fusions and abnormalities of the elbows (radial head dislocation, radiohumetal synosfosis).

E. G. Kassner; I. Katz; Q. H. Qazi

1976-01-01

212

Foot abnormalities of wild birds  

USGS Publications Warehouse

The various foot abnormalities that occur in birds, including pox, scaly-leg, bumble-foot, ergotism and freezing are reviewed. In addition, our findings at the Patuxent Wildlife Research Center include pox from dove, mockingbird, cowbird, grackle and several species of sparrows. Scaly-leg has been particularly prevalent on icterids. Bumble foot has been observed in a whistling swan and in a group of captive woodcock. Ergotism is reported from a series of captive Canada geese from North Dakota. Several drug treatments recommended by others are presented.

Herman, C.M.; Locke, L.N.; Clark, G.M.

1962-01-01

213

A model of abnormal gastric electrical activity  

Microsoft Academic Search

A mathematical model of abnormal gastric electrical activity is presented and used to investigate the accuracy of surface EGGs in the detection of gastric electrical abnormalities. The results show that current surface electrode configurations, cannot detect abnormalities that are not widespread. Substantial improvements can be obtained by using electrode arrays. Surface maps of the slow waves and the signal-to-noise ratio

B. O. Familoni; T. L. Abell; R. Praturu; S. Katragadda; P. Sabourin

1989-01-01

214

The profile of body abnormalities of bodybuilders  

Microsoft Academic Search

Situational abnormalities usually occur due to the non-standard use of body which leads in the deformity of body and has lost of side effects. The purpose of this study was to investigate the type and incidence of skeletal abnormalities in bodybuilders. Situational abnormality of 118 bodybuilders were assessed via posture screen and inserted in examination form. ?2 Test was used

Mahdi Rostami Haji-Abadi; Nader Rahnama

2010-01-01

215

Disorders caused by chromosome abnormalities  

PubMed Central

Many human genetic disorders result from unbalanced chromosome abnormalities, in which there is a net gain or loss of genetic material. Such imbalances often disrupt large numbers of dosage-sensitive, developmentally important genes and result in specific and complex phenotypes. Alternately, some chromosomal syndromes may be caused by a deletion or duplication of a single gene with pleiotropic effects. Traditionally, chromosome abnormalities were identified by visual inspection of the chromosomes under a microscope. The use of molecular cytogenetic technologies, such as fluorescence in situ hybridization and microarrays, has allowed for the identification of cryptic or submicroscopic imbalances, which are not visible under the light microscope. Microarrays have allowed for the identification of numerous new syndromes through a genotype-first approach in which patients with the same or overlapping genomic alterations are identified and then the phenotypes are described. Because many chromosomal alterations are large and encompass numerous genes, the ascertainment of individuals with overlapping deletions and varying clinical features may allow researchers to narrow the region in which to search for candidate genes. PMID:23776360

Theisen, Aaron; Shaffer, Lisa G

2010-01-01

216

Abnormality on Liver Function Test  

PubMed Central

Children with abnormal liver function can often be seen in outpatient clinics or inpatients wards. Most of them have respiratory disease, or gastroenteritis by virus infection, accompanying fever. Occasionally, hepatitis by the viruses causing systemic infection may occur, and screening tests are required. In patients with jaundice, the tests for differential diagnosis and appropriate treatment are important. In the case of a child with hepatitis B virus infection vertically from a hepatitis B surface antigen positive mother, the importance of the recognition of immune clearance can't be overstressed, for the decision of time to begin treatment. Early diagnosis changes the fate of a child with Wilson disease. So, screening test for the disease should not be omitted. Non-alcoholic fatty liver disease, which is mainly discovered in obese children, is a new strong candidate triggering abnormal liver function. Muscular dystrophy is a representative disease mimicking liver dysfunction. Although muscular dystrophy is a progressive disorder, and early diagnosis can't change the fate of patients, it will be better to avoid parent's blame for delayed diagnosis. PMID:24511518

2013-01-01

217

Quadrupole-based glow discharge mass spectrometer: Design and results compared to secondary ion mass spectrometry analyses  

Microsoft Academic Search

A design of quadrupole-based glow discharge mass spectrometer is briefly presented. A glow discharge occurs when a DC voltage (up to 3kV) is applied between two electrodes in a cell filled with Ar at ?1hPa pressure. In this configuration, the sample acts as the cathode, and its surface (?12mm2) is sputtered by impacting Ar ions. The sputtered neutral atoms are

Piotr Konarski; Krzysztof Kaczorek; Micha? ?wil; Jerzy Marks

2007-01-01

218

High-Voltage, glow-discharge electron sources and possibilities of its application in industry for realizing different technological operations  

Microsoft Academic Search

Important problems of generation and forming electron beams in electrode systems of a high-voltage glow discharge are discussed. Also considered are dependencies of energetic parameters on the formed electron beam as well as on anode plasma parameters from the discharge voltage and current. Examples are given of some up-to-date and advanced possibilities of using high-voltage, glow-discharge electron beam sources for

Stanislav V. Denbnovetsky; Vitaliy G. Melnyk; Igor V. Melnyk

2003-01-01

219

An assessment of the impact of spacecraft glow on the Hubble space telescope. Summary of existing observations and theory  

Microsoft Academic Search

Visible spacecraft glow was first observed on the Atmospheric Explorer spacecraft (AE-E) and studied in some detail with the Visible Airglow Experiment (VAE). The AE-E was a spin-stabilized spacecraft without thrusters at an altitude of 140 to 280 km. The VAE contained six visible wavelength photometers that measured a glow spectrum which: (1) rose steeply in the red, (2) decreased

J. T. Clarke

1985-01-01

220

Atomic iodine production in a gas flow by decomposing methyl iodide in a dc glow discharge  

SciTech Connect

The production of atomic iodine for an oxygen - iodine laser is studied by decomposing methyl iodide in a dc glow discharge in a vortex gas flow. The concentration of iodine atoms in discharge products was measured from the atomic iodine absorption of the radiation of a single-frequency tunable diode laser at a wavelength of 1.315 {mu}m. Atomic iodine concentrations sufficient for the operation of an oxygen - iodine laser were obtained. The concentration of atomic iodine amounted to 3.6 x 10{sup 15} cm{sup -3} for a pressure of the carrying argon gas of 15 Torr. The discharge stabilisation by a vortex gas flow allowed the glow discharge to be sustained in a strongly electronegative halogen-containing gas mixture for pressures up to 20 Torr. (active media)

Mikheyev, P A; Shepelenko, A A; Voronov, A I; Kupryaev, Nikolai V [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2002-01-31

221

Profiling Tropospheric Winds with the Goddard Lidar Observatory for Winds (GLOW)  

NASA Technical Reports Server (NTRS)

The Goddard Lidar Observatory for Winds (GLOW) is a mobile direct detection Doppler lidar system designed to measure wind profiles from the surface into the lower stratosphere. Recently, the GLOW lidar has participated in several field deployments measuring tropospheric winds in a variety of conditions including both daytime and night operation. More than 50 hours of line-of-sight wind profit data were obtained in September, 2000 during a three week intercomparison experiment at the Ground Winds facility in North Glen, NH. Typical clear air lidar wind profiles extended to altitudes of 20 km with a 1 km vertical resolution and 1 minute averaging. An additional 40 hours of lidar profiles of wind speed and direction were obtained during HARGLO-2, an intercomparison experiment held at Wallops Flight Facility, VA in November, 2001. A description of the mobile system is presented along with the examples of validated lidar wind profiles obtained during these experiments.

Gentry, Bruce M.; Chen, Huailin; Starr, David OC. (Technical Monitor)

2002-01-01

222

Glow corona generation and streamer inception at the tip of grounded objects during thunderstorms: revisited  

NASA Astrophysics Data System (ADS)

The initiation of streamers prior to a lightning strike can be reportedly inhibited by glow corona discharges generated from tall objects. In contrast to previous studies based on a simplified one-dimensional model of glow corona, a two-dimensional evaluation of the corona ion drift from tall objects is used here to analyse this effect quantitatively. Proper estimates for the corona space charge distribution generated during both the charging process of a thundercloud and the descent of the downward stepped leader are thus calculated. It is found that the shielding effect of the corona space charge on the streamer inception is not as severe as previously reported. Estimations of the effective height of the downward leader tip at which streamer inception takes place are presented and discussed for lightning rods and dissipation array systems.

Becerra, Marley

2013-04-01

223

Comparative study on nonlinear dynamics of magnetized and un-magnetized dc glow discharge plasma  

NASA Astrophysics Data System (ADS)

Various nonlinear dynamical behaviors are experimentally observed to exist in magnetized dc glow discharge plasma. Nonlinear plasma fluctuations are seen evolving when the initial parameters such as discharge voltage, filling pressures, etc are changed in the presence of external magnetic field. A transition pattern of chaotic to quasiperiodicity is experimentally observed when a magnetic field is applied, which is not the case in the un-magnetized one. Hence, a comparative analysis is being conducted for both the cases of magnetized and un-magnetized plasma. The nonlinear behavior of the plasma oscillations are diagnosed by different techniques namely: power spectrum, phase space plotting, correlation dimension, Liapunov exponent, fractal dimension and Hurst exponent. Furthermore, it is noticed that with increasing discharge voltage, the glow emerges from the cathode, slowly moves toward the anode and finally sinks into the anode in a ballooning manner.

Sarma, Bornali; Chauhan, Sourabh S.; Wharton, A. M.; Sekar Iyengar, A. N.

2013-12-01

224

Bidimensional characterization of the emission spectra in a direct current atmospheric pressure glow discharge  

NASA Astrophysics Data System (ADS)

An in-house atmospheric pressure glow discharge source, designed to be used as ionization/desorption source for ambient mass spectrometry, has been electrically characterized, and its optical emission spectra evaluated in detail. Electrical characterization showed that the plasma regime can vary from glow discharge to arc discharge depending on operating conditions (i.e. He flow rate and inter electrode distance). Furthermore, bidimensional images of the optical emission of some plasma species using filters as wavelength selectors, were registered from inside and outside the discharge chamber (inner region and afterglow region respectively), showing the spatial distribution of excited species (i.e. He*, N2+ and O*). These distribution patterns are useful to study the chemistry of the discharge plasma, since different production pathways and different excitation energies affect the presence of these species in the plasma regions.

Orejas, Jaime; Pisonero, Jorge; Bordel, Nerea; Nelis, Thomas; Guillot, Philippe; Sanz-Medel, Alfredo

2012-10-01

225

Estimation of electron temperature in transient glow discharge using ionization wave  

SciTech Connect

Through ionization waves (striation), the transition of glow discharge to arc discharge was observed and relevant electron temperatures were determined experimentally. The velocity of ionization waves in a cathode flare increased from twofold to threefold that in an anode flare. It was assumed that the electron temperature of an anode flare was 4.0-fold to 8.4-fold higher than that in a dark space, and the typical electron temperatures in a dark space and an anode flare were 1.8x10{sup 3} and 1.0x10{sup 4} K, respectively. The electron temperature of the anode flare agreed well with the theoretical value of a positive column in steady glow discharge.0.

Hoshi, Y.; Yokota, A.; Yoshida, H.; Akedo, J. [National Institute of Advanced Industrial Science and Technology, AIST Tsukuba East, Tsukuba, Ibaraki 305-8564 (Japan)

2006-07-01

226

Plasma Treatment of Polyethylene Powder Particles in Hollow Cathode Glow Discharge  

NASA Astrophysics Data System (ADS)

Polyethylen (PE) is widely used in the production of foils, insulators, packaging materials, plastic bottles etc. Untreated PE is hydrophobic due to its unpolar surface. Therefore, it is hard to print or glue PE and the surface has to be modified before converting. In the present experiments a hollow cathode glow discharge is used as plasma source which is mounted in a spiral conveyor in order to ensure a combines transport of PE powder particles. With this set-up a homogeneous surface treatment of the powder is possible while passing the glow discharge. The plasma treatment causes a remarkable enhancement of the hydrophilicity of the PE powder which can be verified by contact angle measurements and X-ray photoelectron spectroscopy.

Wolter, Matthias; Quitzau, Meike; Bornholdt, Sven; Kersten, Holger

2008-09-01

227

Time series analysis of ionization waves in dc neon glow discharge  

SciTech Connect

The dynamics of dc neon glow discharge is examined by calculating a Lyapunov exponent spectrum (LES) and correlation dimension (D{sub corr}) from experimental time series. The embedding theory is used to reconstruct an attractor with the delay coordinate method. The analysis refers to periodic, chaotic, and quasi-periodic attractors. The results obtained are confirmed by a comparison with other methods of time series analysis such as the Fourier power spectrum and autocorrelation function. The main object of the present work is the positive column of a dc neon glow discharge. The positive column is an excellent model for the study of a non-linearity plasma system because it is nonisothermal plasma far from equilibrium.

Hassouba, M. A.; Al-Naggar, H. I.; Al-Naggar, N. M.; Wilke, C. [Department of Physics, Faculty of Science, Benha University (Egypt); Institute of Physics, E. M. A. University, Domstrasse 10a, 17489 Greifswald (Germany)

2006-07-15

228

The impact of light source spectral power distribution on sky glow  

NASA Astrophysics Data System (ADS)

The effect of light source spectral power distribution on the visual brightness of anthropogenic sky glow is described. Under visual adaptation levels relevant to observing the night sky, namely with dark-adapted (scotopic) vision, blue-rich (“white”) sources produce a dramatically greater sky brightness than yellow-rich sources. High correlated color temperature LEDs and metal halide sources produce a visual brightness up to 8× brighter than low-pressure sodium and 3× brighter than high-pressure sodium when matched lumen-for-lumen and observed nearby. Though the sky brightness arising from blue-rich sources decreases more strongly with distance, the visual sky glow resulting from such sources remains significantly brighter than from yellow sources out to the limits of this study at 300 km.

Luginbuhl, Christian B.; Boley, Paul A.; Davis, Donald R.

2014-05-01

229

Plasma Treatment of Polyethylene Powder Particles in Hollow Cathode Glow Discharge  

SciTech Connect

Polyethylen (PE) is widely used in the production of foils, insulators, packaging materials, plastic bottles etc. Untreated PE is hydrophobic due to its unpolar surface. Therefore, it is hard to print or glue PE and the surface has to be modified before converting.In the present experiments a hollow cathode glow discharge is used as plasma source which is mounted in a spiral conveyor in order to ensure a combines transport of PE powder particles. With this set-up a homogeneous surface treatment of the powder is possible while passing the glow discharge. The plasma treatment causes a remarkable enhancement of the hydrophilicity of the PE powder which can be verified by contact angle measurements and X-ray photoelectron spectroscopy.

Wolter, Matthias; Quitzau, Meike; Bornholdt, Sven; Kersten, Holger [IEAP, University Kiel, Kiel (Germany)

2008-09-07

230

Differentiation of Chinese liquors by using ambient glow discharge ionization mass spectrometry.  

PubMed

Chinese liquors are often a very important part of social event in China. Driven by high profit, some illegal traders often use inferior liquors instead of the products with high quality to cheat the customer. Therefore, it is highly required to authenticate Chinese liquors. In this paper a novel method based on ambient glow discharge ionization mass spectrometry has been developed to differentiate Chinese liquors. Volatile components from liquor samples were ionized by the plasma generated by glow discharge and then detected by a commercial linear ion trap mass spectrometer. Consequently, the fingerprint mass spectra of several Chinese liquors were obtained. Combined with principal component analysis, this new method was successfully applied to differentiate different brands of Chinese liquors without any sample pretreatment. Compared with conventional methods, this novel method has the advantages of easy operation, high speed, and high efficiency, which make it a potential tool in the fields of food safety, atmosphere chemistry. PMID:23689281

Zhen, Cheng; Zhou, Yueming; Zhang, Ning; Wang, Jiyun; Xiong, Caiqiao; Chen, Suming; Nie, Zongxiu

2013-07-01

231

TECHNICAL NOTE: A miniaturized glow discharge applied for optical emission detection in aqueous analytes  

NASA Astrophysics Data System (ADS)

DC glow discharge atomic emission spectroscopy of aqueous analytes has been performed in a planar glass microstructure at close to atmospheric pressure using argon as a carrier gas. Sample introduction was achieved using a technique in which the liquid sample itself is employed as the cathode for the glow discharge. To attain sufficient transport of the sample into the discharge region to allow for emission spectroscopy, acidification of the liquid sample is required. Results demonstrate the detection of copper in solution is possible with the observation of five atomic emission lines of copper (at 325 nm, 327 nm, 511 nm, 515 nm and 522 nm). It is hoped that this detection method could be integrated with other micro-fluidic systems as part of a ?-TAS device as well as being useful as a portable, stand-alone detector. However, stability issues will need to be resolved to allow for further optimization and characterization of the device.

Jenkins, G.; Manz, A.

2002-09-01

232

Lidar Wind Measurements with the Goddard Lidar Observatory for Winds (GLOW)  

NASA Technical Reports Server (NTRS)

We report on the development of GLOW (Goddard Lidar Observatory for Winds), a mobile Doppler lidar system which uses direct detection Doppler lidar techniques to measure wind profiles from the surface into the lower stratosphere. The system employs a Nd:YAG laser transmitter to measure winds using either aerosol backscatter at a wavelength of 1064 run or molecular backscatter at 355 nm. The system is modular in design to allow the incorporation of new technologies as they become available. GLOW is intended to be used as a deployable field system for studying atmospheric dynamics and transport and can also serve as a testbed to evaluate candidate technologies developed for use in future spaceborne systems. Finally it can be used for calibration/validation activities following launch of spaceborne wind lidar systems. A description of the mobile system is presented along with the first validated lidar wind profiles obtained with the system using a new molecular 'double edge' receiver.

Gentry, Bruce M.; Li, Steven X.; Chen, Hualilin; Einaudi, Franco (Technical Monitor)

2000-01-01

233

Ion nitriding of titanium and zirconium by a dc-glow discharge method. [Surface phases  

Microsoft Academic Search

Nitrided surfaces of titanium and zirconium were prepared by operating a dc-glow discharge in a mixture of 20% Nâ and 80% Hâ at 20 to 40 Torr. The discharge was confined between a stainless steel anode and the sample at about 500 mA with a dc potential of 360 to 400 V. The temperature of the sample was about 900°C.

M. B. Liu; D. M. Gruen; A. R. Krauss; A. H. Jr. Reis; S. W. Peterson

1978-01-01

234

Ion nitriding of titanium and zirconium by a dc-glow discharge method  

Microsoft Academic Search

Nitrided surfaces of titanium and zirconium were prepared by operating a dc-glow discharge in a mixture of 20% Nâ and 80% Hâ at 20 to 40 Torr. The discharge was confined between a stainless steel anode and the sample at about 500 mA with a dc potential of 360 to 400 V. The temperature of the sample was about 900°C.

M. B. Liu; D. M. Gruen; A. R. Krauss; A. H. Jr. Reis; S. W. Peterson

1978-01-01

235

High-current, large volume glow plasma production using pulse modulator  

Microsoft Academic Search

Glow discharge plasma was produced with large current up to 150 A using a pulse modulator or a capacitor discharge in dry air (N2:O2=8:2) or pure nitrogen gas. Rogowski profile electrodes having 107 mm diameter were set in the discharge chamber. The gap length of the electrodes was changed from 1 mm to 20 mm in various gas pressures 1-20

Koichi Takaki; Ryuji Hasegawa; Seiji Mukaigawa; Tamiya Fujiwara; Daichi Taguchi

2002-01-01

236

Functionalizing Single-Wall Carbon Nanotubes in Hollow Cathode Glow Discharges  

Microsoft Academic Search

A hollow cathode glow discharge was used to functionalize single-wall carbon nanotubes. This low temperature, solvent free,\\u000a facile and fast process may be used to efficiently attach various functional groups (COOH, OH, CH, NH2, NO2 and NO) to the open ends and sidewalls of carbon nanotubes. The presented technique yields a broader set of functional groups\\u000a being attached to the

M. Bystrzejewski; M. H. Rümmeli; T. Gemming; T. Pichler; A. Huczko; H. Lange

2009-01-01

237

The effect of the gas temperature gradient on dust structures in a glow-discharge plasma  

Microsoft Academic Search

An experimental investigation is performed of the effect of the neutral gas temperature gradient on plasma-dust formations\\u000a in the positive column of a glow discharge. It is demonstrated that the thermophoretic forces arising due to the temperature\\u000a gradient are comparable with radial electric fields and define the condition of formation and different shapes of plasma-dust\\u000a structures, in particular, the formation

V. V. Balabanov; L. M. Vasilyak; S. P. Vetchinin; A. P. Nefedov; D. N. Polyakov; V. E. Fortov

2001-01-01

238

Study of the glow curve structure of the minerals separated from black pepper (Piper nigrum L.)  

Microsoft Academic Search

The inorganic mineral fraction extracted from black pepper (Piper nigrum L.) has been analysed using a thermoluminescence (TL) method, investigating the glow curve structure, including an evaluation of the kinetic parameters. Different grain sizes, i.e. 10, 74, and 149 ?m, were selected from commercial black pepper. The X-ray diffraction of the inorganic fraction shows that quartz is the main mineral present

S. Guzmán; B. Ruiz Gurrola; E. Cruz-Zaragoza; A. Tufiño; C. Furetta; A. Favalli; F. Brown

2011-01-01

239

Plasma immersion ion implantation using a glow discharge source with controlled plasma potential  

Microsoft Academic Search

A DC glow discharge plasma source was used in a plasma immersion ion implantation (PIII) experiment providing nitrogen plasmas with densities of 1–3×1010cm?3 and temperatures of 5–10 eV. Nitrogen ions were extracted from these plasmas and implanted in a variety of immersed samples (Al 5040, SS 304, Si) using repetitive high voltage pulses from two types of sources: PFN pulser

M. Ueda; G. F. Gomes; L. A. Berni; J. O. Rossi; J. J. Barroso; A. F. Beloto; E. Abramof; H. Reuther

2000-01-01

240

Spatially Resolved Temperature Measurements of Atmospheric-Pressure Normal Glow Microplasmas in Air  

Microsoft Academic Search

The rotational and vibrational temperatures of DC normal glow air discharges were measured by comparing modeled optical emission spectra of the N2 second positive system with spectroscopic measurements from the discharges. By using an imaging spectrometer and optical assembly, the temperature measurements were spatially resolved to about 6 mum. Results are presented for a 3.8-mA discharge at an electrode spacing

David Staack; Bakhtier Farouk; Alexander F. Gutsol; Alexander Fridman

2007-01-01

241

Etching of uranium dioxide in nitrogen trifluoride RF plasma glow discharge  

Microsoft Academic Search

A series of room temperature, low pressure (10.8 to 40 Pa), low power (25 to 210 W) RF plasma glow discharge experiments with UO2 were conducted to demonstrate that plasma treatment is a viable method for decontaminating UO2 from stainless steel substrates. Experiments were conducted using NF3 gas to decontaminate depleted uranium dioxide from stainless-steel substrates. Results demonstrated that UO2

John Mark Veilleux

1999-01-01

242

Abnormal iron homeostasis and neurodegeneration  

PubMed Central

Abnormal iron metabolism is observed in many neurodegenerative diseases, however, only two have shown dysregulation of brain iron homeostasis as the primary cause of neurodegeneration. Herein, we review one of these - hereditary ferritinopathy (HF) or neuroferritinopathy, which is an autosomal dominant, adult onset degenerative disease caused by mutations in the ferritin light chain (FTL) gene. HF has a clinical phenotype characterized by a progressive movement disorder, behavioral disturbances, and cognitive impairment. The main pathologic findings are cystic cavitation of the basal ganglia, the presence of ferritin inclusion bodies (IBs), and substantial iron deposition. Mutant FTL subunits have altered sequence and length but assemble into soluble 24-mers that are ultrastructurally indistinguishable from those of the wild type. Crystallography shows substantial localized disruption of the normally tiny 4-fold pores between the ferritin subunits because of unraveling of the C-termini into multiple polypeptide conformations. This structural alteration causes attenuated net iron incorporation leading to cellular iron mishandling, ferritin aggregation, and oxidative damage at physiological concentrations of iron and ascorbate. A transgenic murine model parallels several features of HF, including a progressive neurological phenotype, ferritin IB formation, and misregulation of iron metabolism. These studies provide a working hypothesis for the pathogenesis of HF by implicating (1) a loss of normal ferritin function that triggers iron accumulation and overproduction of ferritin polypeptides, and (2) a gain of toxic function through radical production, ferritin aggregation, and oxidative stress. Importantly, the finding that ferritin aggregation can be reversed by iron chelators and oxidative damage can be inhibited by radical trapping may be used for clinical investigation. This work provides new insights into the role of abnormal iron metabolism in neurodegeneration. PMID:23908629

Muhoberac, Barry B.; Vidal, Ruben

2013-01-01

243

The role of electronic mechanisms in surface erosion and glow phenomena  

NASA Technical Reports Server (NTRS)

Experimental studies of desorption induced by electronic transitions (DIET) are described. Such studies are producing an increasingly complete picture of the dynamical pathways through which incident electronic energy is absorbed and rechanneled to produce macroscopic erosion and glow. These mechanistic studies can determine rate constants for erosion and glow processes in model materials and provide valuable guidance in materials selection and development. Extensive experiments with electron, photon, and heavy particle irradiation of alkali halides and other simple model materials have produced evidence showing that: (1) surface erosion, consisting primarily in the ejection or desorption of ground-state neutral atoms, occurs with large efficiencies for all irradiated species; (2) surface glow, resulting from the radiative decay of desorbed atoms, likewise occurs for all irradiating species; (3) the typical mechanism for ground-state neutral desorption is exciton formation, followed by relaxation to a permanent, mobile electronic defect which is the precursor to bond-breaking in the surface or near-surface bulk of the material; and (4) the mechanisms for excited atom formation may include curve crossing in atomic collisions, interactions with surface defect or impurity states, or defect diffusion.

Haglund, Richard F., Jr.

1987-01-01

244

The interplanetary hydrogen and helium glow and the inferred interstellar gas properties  

NASA Technical Reports Server (NTRS)

Observations of the interplanetary hydrogen and helium glow have been obtained by a number of spacecraft and rocket experiments during the past fifteen years. Important results have been established on the temperature, density, velocity, spatial dependence, and hydrogen to helium ratio. However, only four spacecraft launched to date are investigating the outer solar system and of these four the Pioneer 10 spacecraft is the farthest out at 28 A.U. Observations from this spacecraft at great distances have permitted an improved analysis of the effects which are only evident at large distances from the Sun. Perhaps the most significant result in this regard is the clear evidence of the importance of multiple scattering of solar Ly-alpha; an effect which has not been observed in earlier work. Ignoring this effect can lead to a gross overestimate of the local galactic glow. Current best estimates of the galactic glow and the local interstellar wind parameters obtained by the Pioneer 10 photometer at great distances are presented, in addition to complementary experimental observations of particular interest.

Judge, D. L.

1983-01-01

245

Distribution and phylogenetic relationships of Australian glow-worms Arachnocampa (Diptera, Keroplatidae).  

PubMed

Glow-worms are bioluminescent fly larvae (Order Diptera, genus Arachnocampa) found only in Australia and New Zealand. Their core habitat is rainforest gullies and wet caves. Eight species are present in Australia; five of them have been recently described. The geographic distribution of species in Australia encompasses the montane regions of the eastern Australian coastline from the Wet Tropics region of northern Queensland to the cool temperate and montane rainforests of southern Australia and Tasmania. Phylogenetic trees based upon partial sequences of the mitochondrial genes cytochrome oxidase II and 16S mtDNA show that populations tend to be clustered into allopatric geographic groups showing overall concordance with the known species distributions. The deepest division is between the cool-adapted southern subgenus, Lucifera, and the more widespread subgenus, Campara. Lucifera comprises the sister groups, A. tasmaniensis, from Tasmania and the newly described species, A. buffaloensis, found in a high-altitude cave at Mt Buffalo in the Australian Alps in Victoria. The remaining Australian glow-worms in subgenus Campara are distributed in a swathe of geographic clusters that extend from the Wet Tropics in northern Queensland to the temperate forests of southern Victoria. Samples from caves and rainforests within any one geographic location tended to cluster together within a clade. We suggest that the morphological differences between hypogean (cave) and epigean (surface) glow-worm larvae are facultative adaptations to local microclimatic conditions rather than due to the presence of cryptic species in caves. PMID:18583158

Baker, Claire H; Graham, Glenn C; Scott, Kirsten D; Cameron, Stephen L; Yeates, David K; Merritt, David J

2008-08-01

246

Atmospheric pressure glow discharge deposition of thermo-sensitive poly (N-isopropylacrylamide)  

NASA Astrophysics Data System (ADS)

In this paper, a self-made atmospheric pressure dielectric barrier discharge reactor on intermediate frequency is brought forward and developed, which is equipped with power supply of 1-20 KHz, and the working gas is argon. The experimental results show that is a very stable and uniform atmospheric pressure glow discharge (APGD). Through a series of experiments, the waveforms of single pulse and multi-pulse glow discharge were both obtained. The voltage amplitude, discharge gap and dielectric material are studied, and the conditions of multi-pulse glow discharge are discussed as well. The novel methods of depositing poly (N-isopropylacrylamide) (PNIPAAm) coatings on the surface of glass slides and PS petri dish are provided by atmospheric pressure plasma polymerization. PNIPAAm can be obtained by plasma polymerization of N-isopropylacrylamide using the self-made equipment of atmospheric pressure plasma vapor treatment. The samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle. SEM analysis has revealed that the PNIPAAm coatings were formed on the surface of the smooth glass slides. Further evaluation by using XPS, it has shown the presence of PNIPAAm. The wettability can be significantly modified by changing of the temperatures at above and below of the lower critical solution temperature (LCST) from the data of the contact angle test. These results have advantage for further application on the thermo-sensitive textile materials.

Shao, M.; Tang, X. L.; Wen, D.; Chen, Y.; Qiu, G.

2013-12-01

247

Mechanism behind self-sustained oscillations in direct current glow discharges and dusty plasmas  

SciTech Connect

An alternative explanation to the mechanism behind self-sustained oscillations of ions in direct current (DC) glow discharges is provided. Such description is distinguished from the one provided by the fluid models, where oscillations are attributed to the positive feedback mechanism associated with photoionization of particles and photoemission of electrons from the cathode. Here, oscillations arise as consequence of interaction between an ion and the surface charges induced by it at the bounding electrodes. Such mechanism provides an elegant explanation to why self-sustained oscillations occur only in the negative resistance region of the voltage-current characteristic curve in the DC glow discharges. Furthermore, this alternative description provides an elegant explanation to the formation of plasma fireballs in the laboratory plasma. It has been found that oscillation frequencies increase with ion's surface charge density, but at the rate which is significantly slower than it does with the electric field. The presented mechanism also describes self-sustained oscillations of ions in dusty plasmas, which demonstrates that self-sustained oscillations in dusty plasmas and DC glow discharges involve common physical processes.

Cho, Sung Nae [Devices R and D Center, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Mt. 14-1 Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-712 (Korea, Republic of)

2013-04-15

248

Potential Industrial Applications of the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) Operating in Ambient Air  

NASA Astrophysics Data System (ADS)

The majority of industrial plasma processing with glow discharges has been conducted at pressures below 10 torr. This tends to limit applications to high value workpieces as a result of the high capital cost of vacuum systems and the production constraints of batch processing. It has long been recognized that glow discharge plasmas would play a much larger industrial role if they could be generated at one atmosphere. The One Atmosphere Uniform Glow Discharge Plasma (OAUGDP), developed at the University of Tennessee's Plasma Sciences Laboratory, is a non-thermal RF plasma operating on displacement currents with the time-resolved characteristics of a classical low pressure DC normal glow discharge. As a glow discharge, the OAUGDP operates with maximum electrical efficiency at the Stoletow point, where the energy input per ion-electron pair is a minimum [1, 2]. Several interdisciplinary teams have investigated potential applications of the OAUGDP. These teams included collaborators from the UTK Textiles and Nonwovens Development Center (TANDEC), and the Departments of Electrical and Computer Engineering, Microbiology, and Food Science and Technology, as well as the NASA Langley Research Center. The potential applications of the OAUGDP have all been at one atmosphere and room temperature, using air as the working gas. These applications include sterilizing medical and dental equipment; sterilizable air filters to deal with the "sick building syndrome"; removal of soot from Diesel engine exhaust; subsonic plasma aerodynamic effects, including flow re-attachment to airfoils and boundary layer modification; electrohydrodynamic (EDH) flow control of working gases; increasing the surface energy of materials; improving the adhesion of paints and electroplated layers: improving the wettability and wickability of fabrics; stripping of photoresist; and plasma deposition and directional etching of potential microelectronic relevance. [1] J. R. Roth, Industrial Plasma Engineering: Volume I, Principles. Institute of Physics Publishing, Bristol and Philadelphia 1995, ISBN 0-7503-0318-2. [2] Roth, J. R. Industrial Plasma Engineering: Volume II Applications to Nonthermal Plasma Processing Institute of Physics Publishing, Bristol and Philadelphia. 2001, ISBN 0-7503-0545-2.

Reece Roth, J.

2004-11-01

249

On detecting abnormalities in digital mammography  

Microsoft Academic Search

Breast cancer is the most common cancer in many countries all over the world. Early detection of cancer, in either diagnosis or screening programs, decreases the mortality rates. Computer Aided Detection (CAD) is software that aids radiologists in detecting abnormalities in medical images. In this article we present our approach in detecting abnormalities in mammograms using digital mammography. Each mammogram

Waleed A. Yousef; Waleed A. Mustafa; Ali A. Ali; Naglaa A. Abdelrazek; Ahmed M. Farrag

2010-01-01

250

Renal abnormalities and their developmental origin  

Microsoft Academic Search

Congenital abnormalities of the kidney and urinary tract (CAKUT) occur in 1 out of 500 newborns, and constitute approximately 20–30% of all anomalies identified in the prenatal period. CAKUT has a major role in renal failure, and there is increasing evidence that certain abnormalities predispose to the development of hypertension and cardiovascular disease in adult life. Moreover, defects in nephron

Andreas Schedl

2007-01-01

251

Dark Immunofluorescence: Correlation with Serum Immunoglobulin Abnormalities?  

PubMed Central

Occasional serum samples (<0.5%) tested by indirect immunofluorescence showed less fluorescence than did negative-control serum. A retrospective review of these patients' serum immunoglobulins revealed a high percentage of abnormalities (71%, versus 22% of controls). We suggest that this observation should be reported when seen and that the clinician should be alerted to an association with immunoglobulin abnormalities. PMID:16971516

List, J.; Buckland, M. S.; Thobhani, B.; Sheed, C. J.; Mann, J. C.; Claxton, M.; Heelan, B.

2006-01-01

252

Immune Abnormalities in Patients with Autism.  

ERIC Educational Resources Information Center

A study of 31 autistic patients (3-28 years old) has revealed several immune-system abnormalities, including decreased numbers of T lymphocytes and an altered ratio of helper-to-suppressor T cells. Immune-system abnormalities may be directly related to underlying biologic processes of autism or an indirect reflection of the actual pathologic…

Warren, Reed P.; And Others

1986-01-01

253

Multiparametric tissue abnormality characterization using manifold regularization  

NASA Astrophysics Data System (ADS)

Tissue abnormality characterization is a generalized segmentation problem which aims at determining a continuous score that can be assigned to the tissue which characterizes the extent of tissue deterioration, with completely healthy tissue being one end of the spectrum and fully abnormal tissue such as lesions, being on the other end. Our method is based on the assumptions that there is some tissue that is neither fully healthy or nor completely abnormal but lies in between the two in terms of abnormality; and that the voxel-wise score of tissue abnormality lies on a spatially and temporally smooth manifold of abnormality. Unlike in a pure classification problem which associates an independent label with each voxel without considering correlation with neighbors, or an absolute clustering problem which does not consider a priori knowledge of tissue type, we assume that diseased and healthy tissue lie on a manifold that encompasses the healthy tissue and diseased tissue, stretching from one to the other. We propose a semi-supervised method for determining such as abnormality manifold, using multi-parametric features incorporated into a support vector machine framework in combination with manifold regularization. We apply the framework towards the characterization of tissue abnormality to brains of multiple sclerosis patients.

Batmanghelich, Kayhan; Wu, Xiaoying; Zacharaki, Evangelia; Markowitz, Clyde E.; Davatzikos, Christos; Verma, Ragini

2008-03-01

254

Predicting Abnormal Returns Using Debt Ratios  

Microsoft Academic Search

This paper investigates the ability of the company capital structures to be used as a predictor for abnormal returns in the US stock market in the long run. The relationship between debt level and abnormal return over a three-year holding period is investigated. Robustness tests are carried out to determine the predictive ability of debt ratios when controlling for size

Brian Baturevich; Gulnur Muradoglu

255

Research Report: Students' knowledge of abnormal psychology  

Microsoft Academic Search

The present study aims to compare whether final year psychology students (n = 26) could answer more items on a multiple choice questionnaire (MCQ) correctly on abnormal psychology than prospective psychology candidates (n = 77) and final year engineering students (n = 26). The three groups of students completed MCQs in five different fields of abnormal psychology namely; eating disorders,

Adrian Furnham; Bahman Baluch; Fiona Starr

2003-01-01

256

COURSE SYLLABUS Psychology 350: Abnormal Psychology  

E-print Network

COURSE SYLLABUS Psychology 350: Abnormal Psychology Spring 2011 Instructor: Dennis P. Saccuzzo, Ph: Abnormal Psychology by Susan Holen-Hoeksema 4th edition This course covers the history, theories.D., J.D. Meeting Times: Wednesday:-6:40pm Professor of Psychology E-Mail: dsaccuzz

Gallo, Linda C.

257

The present status of abnormal psychology  

Microsoft Academic Search

A statistical analysis of the content of fifteen representative textbooks in abnormal psychology and seven textbooks in psychiatry. It is found that abnormal psychology is a dumping ground for miscellaneous topics left over from general psychology, including sleep, dreams, suggestion, etc. The most conspicuous defect is the lack of experimental material, of which there is only .8%. Another is the

W. A. Hunt; C. Landis

1935-01-01

258

An Abnormal Psychology Community Based Interview Assignment  

ERIC Educational Resources Information Center

A course option in abnormal psychology involves students in interviewing and observing the activities of individuals in the off-campus community who are concerned with some aspect of abnormal psychology. The technique generates student interest in the field when they interview people about topics such as drug abuse, transsexualism, and abuse of…

White, Geoffry D.

1977-01-01

259

Instability of a 550Base Pair DNA Segment and Abnormal Methylation in Fragile X Syndrome  

Microsoft Academic Search

The fragile X syndrome, a common cause of inherited mental retardation, is characterized by an unusual mode of inheritance. Phenotypic expression has been linked to abnormal cytosine methylation of a single CpG island, at or very near the fragile site. Probes adjacent to this island detected very localized DNA rearrangements that consti- tuted the fragile X mutations, and whose target

I. Oberle; F. Rousseau; D. Heitz; C. Kretz; D. Devys; A. Hanauer; J. Boue; M. F. Bertheas; J. L. Mandel

1991-01-01

260

Genetic effects of radio-frequency, atmospheric-pressure glow discharges with helium  

SciTech Connect

Due to low gas temperatures and high densities of active species, atmospheric-pressure glow discharges (APGDs) would have potential applications in the fields of plasma-based sterilization, gene mutation, etc. In this letter, the genetic effects of helium radio-frequency APGD plasmas with the plasmid DNA and oligonucleotide as the treated biomaterials are presented. The experimental results show that it is the chemically active species, instead of heat, ultraviolet radiation, intense electric field, and/or charged particles, that break the double chains of the plasmid DNA. The genetic effects depend on the plasma operating parameters, e.g., power input, helium flow rate, processing distance, time, etc.

Li Guo; Li Heping; Wang Sen; Sun Wenting; Bao Chengyu [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Wang Liyan; Zhao Hongxin; Xing Xinhui [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

2008-06-02

261

Effect of fluorine on the photovoltaic properties of amorphous silicon prepared by dc glow discharge  

NASA Astrophysics Data System (ADS)

Amorphous Si-F-H films were prepared by dc glow discharge in an atmosphere of SiF4 + H2. The electrical and optical properties have been described. Infrared spectra of amorphous Si-F-H have been studied for various deposition pressures. In the n-type doping characteristics, the maximum conductivity obtained is 10.0/ohm-cm with the addition of 500 vppm PH3. The Schottky barrier a-Si-F-H solar cell shows an efficiency of 3.5% under AM1, 100 mW/sq cm insolation.

Nishihata, K.; Konagai, M.; Takahashi, K.; Komori, K.

262

Generation of O2 From CO2 by Glow Discharge And Permeation  

NASA Technical Reports Server (NTRS)

Technique for generating supply of highly pure O2 from CO2 developed. First, atomic oxygen at useful partial pressure generated by glow-discharge dissociation of CO2. Atomic oxygen formed in vicinity of hot silver membrane and permeates through membrane to downstream region, where thermally recombined into O2 and pumped away to storage tank. Pure oxygen stored suitable for human consumption and other uses. Originally developed to convert Martian atmosphere of CO2 to O2 for astronaut consumption. Other potential applications include purification of atmospheres in Space Shuttle and Space Station Freedom. Byproduct CO must be handled by other techniques.

Outlaw, R. A.

1993-01-01

263

Ion focusing in enhanced glow discharge plasma immersion ion implantation of hydrogen and nitrogen into silicon  

NASA Astrophysics Data System (ADS)

Ion focusing in enhanced glow discharge plasma immersion ion implantation (EGD-PIII) of hydrogen into silicon affects the lateral ion fluence uniformity. The phenomenon and its effects are investigated experimentally and theoretically under different conditions and compared to those in nitrogen EGD-PIII. Consistent results are obtained from experiments and numerical simulation disclosing that the lower the plasma density, the more severe is the ion focusing effect. The influence of the negative high voltage on the ion focusing effect is small compared to that of the plasma density.

Lu, Qiu Yuan; Wang, Zhuo; Li, Liu He; Fu, Ricky K. Y.; Chu, Paul. K.

2010-08-01

264

Spot patterns and instabilities in a pulsed low-pressure rf glow discharge  

NASA Astrophysics Data System (ADS)

During the development of a plasma imaging system, luminous streaks and instabilities occurred in a pulsed rf glow discharge operated in Ar at reduced pressure. Sputtering sources with a flat cathode having an area of 10–50 cm2 were designed to reproduce the surface spatial structure of the cathode in the plasma emission, providing optical emission spectrometry with spatial resolution for the chemical analysis of the cathode material. Unfortunately, depending on the discharge parameters and design of the discharge cell, spot patterns appeared and disappeared, and at times were stable or unstable. The behavior and possible origin of these patterns are described in this article.

Voronov, M.; Hoffmann, V.; Steingrobe, T.; Buscher, W.; Engelhard, C.; Storey, A. P.; Ray, S. J.; Hieftje, G. M.

2014-10-01

265

Heating rate effect on thermoluminescence glow curves of LiF:Mg,Cu,P+PTFE phosphor.  

PubMed

The influence of heating rate on the thermoluminescence (TL) property of LiF:Mg,Cu,P+PTFE was analyzed. The activation energy and the frequency factor as a function of the heating rate were determined. The kinetic parameters and their dependence on the heating rate were evaluated using the sequential quadratic programming glow curve deconvolution (SQPGCD). The results showed that as the heating rate increases, the peak intensity at the maximum (I(M)) decreases and shifts to higher temperature; similar behavior of the kinetics parameters was observed. PMID:21683603

Cruz-Zaragoza, E; González, P R; Azorín, J; Furetta, C

2011-10-01

266

Characteristics of nanocomposite films deposited by atmospheric pressure uniform RF glow plasma  

Microsoft Academic Search

Characteristics of nanocomposite films synthesized and deposited by atmospheric pressure Radio-Frequency (RF) (13.56 MHz) uniform glow discharge are examined. The nanocomposite thin film deposition is carried out in the presence of titanium dioxide (TiO2) with polymerization of pyrrole, thiophene and furan monomers in acetonitrile medium containing lithium perchlorate (LiClO4). The chemical, morphological, thermal and electrical characteristics of polypyrrole\\/TiO2 (PPy\\/TiO2), polythiophene\\/TiO2 (PT\\/TiO2)

Aysegul Uygun; Lutfi Oksuz; Ayse Gul Yavuz; Ali Guleç; Songul Sen

2011-01-01

267

Nonlocal control of electron temperature in short direct current glow discharge plasma  

NASA Astrophysics Data System (ADS)

To demonstrate controlling the electron temperature in nonlocal plasma, experiments have been performed on a short (without positive column) dc glow discharge with a cold cathode by applying different voltages to the conducting discharge wall. The experiments have been performed for low-pressure noble gas discharges. The applied voltage can modify trapping the energetic electrons emitted from the cathode sheath and arising from the atomic and molecular processes in the plasma within the device volume. This phenomenon results in the energetic electrons heating the slow plasma electrons, which consequently modifies the electron temperature. Furthermore, a numerical model of the discharge has demonstrated the electron temperature modification for the above case.

Demidov, V. I.; Kudryavtsev, A. A.; Kurlyandskaya, I. P.; Stepanova, O. M.

2014-09-01

268

Self-organization in dc glow microdischarges in krypton: modelling and experiments  

NASA Astrophysics Data System (ADS)

Self-organized patterns of cathodic spots have been observed in microdischarges operated in xenon, but not in other gases. However, modelling has indicated that it is, in principle, possible to observe the patterns of spots in discharges operated in other gases provided that experimental conditions, in particular pressure, are right. In this work, self-organized patterns of cathodic spots are for the first time observed in dc glow microdischarges operated in a gas other than xenon: krypton. The experiments have been guided by the modelling. According to both the experiment and the modelling, patterns in krypton are similar to those found earlier in xenon, however occur at higher pressures.

Zhu, W.; Niraula, P.; Almeida, P. G. C.; Benilov, M. S.; Santos, D. F. N.

2014-10-01

269

Glow discharge simulation through solutions to the moments of the Boltzmann transport equation  

NASA Astrophysics Data System (ADS)

A self-consistent continuum model is presented for glow discharges based on the moments of the Boltzmann transport equation. The resultant set of governing equations consist of continuity and momentum equations for electrons and ions, an energy conservation equation for electrons and Poisson's equation. An efficient numerical scheme to solve the set of coupled equations is presented. Results from case studies of dc discharges are used to illustrate the model. A parametric study varying the cathode voltage, gas pressure, and secondary electron emission coefficient predicts many of the well-known features of dc discharges.

Meyyappan, M.; Kreskovsky, J. P.

1990-08-01

270

Investigation of a novel hollow cathode configuration for Grimm-type glow discharge emission  

NASA Astrophysics Data System (ADS)

A hollow cathode configuration was designed for a Grimm-type glow discharge atomic emission spectrometer (GD-AES). The operating conditions including the hollow cathode dimension, applied pulsed voltage and argon pressure, were optimized. The 10-?s pulses at 1.8 kV in a 3-torr discharge worked best. A pulsed hollow cathode Grimm discharge (HCG) offers several advantages: efficient excitation and ionization; high sensitivity; temporal spectral resolution; and rapid sample interchange. The capability of this source for the determination of elemental composition in metals, alloys and in solution residues is investigated. Samples used in this study included copper and steel standards.

Yang, Chenglong; Harrison, W. W.

2001-07-01

271

The preliminary study on the chemical synthesis between graphite and water by glow-discharge experiments  

NASA Astrophysics Data System (ADS)

Glow-discharge experiments were performed against water using a graphite rod as the anode and a silver thread as the cathode under an Ar atmosphere. UV-spectrum, FT-IR, 1H-NMR spectrum and GC-MS analyses of the solutions irradiated with plasma were studied. It was found that a small amount of carbon was transferred from anode into water and some organic compounds were produced by reaction between carbon and water. Among those, formic acid, acetic acid and propanoic acid were identified as the main products.

Shi, Huai-Bin; Shao, Chun-Lin; Yu, Zeng-Liang

2002-07-01

272

Glow discharge source atomization for the laser-excited atomic fluorescence spectrometric studies of indium  

NASA Astrophysics Data System (ADS)

A demountable glow discharge source has been used for the atomization of the analyte solutions deposited on graphite and copper rod cathodes. Indium atoms are sputtered-atomized from the cathode surface and are excited by a pulsed, frequency-doubled dye laser pumped by the nitrogen laser. Atomic fluorescence measurements were performed using the non-resonance fluorescence transition. The detection limits of indium in aqueous solutions (10?l) deposited on graphite and copper electrodes were 8 × 10 -9 and 11 × 10 -9g, respectively (8 ng and 11ng).

Patel, B. M.; Winefordner, J. D.

273

Numerically abnormal chromosome constitutions in humans  

SciTech Connect

Chapter 24, discusses numerically abnormal chromosome constitutions in humans. This involves abnormalities of human chromosome number, including polyploidy (when the number of sets of chromosomes increases) and aneuploidy (when the number of individual normal chromosomes changes). Chapter sections discuss the following chromosomal abnormalities: human triploids, imprinting and uniparental disomy, human tetraploids, hydatidiform moles, anomalies caused by chromosomal imbalance, 13 trisomy (D{sub 1} trisomy, Patau syndrome), 21 trisomy (Down syndrome), 18 trisomy syndrome (Edwards syndrome), other autosomal aneuploidy syndromes, and spontaneous abortions. The chapter concludes with remarks on the nonrandom participation of chromosomes in trisomy. 69 refs., 3 figs., 4 tabs.

NONE

1993-12-31

274

Development of ac corona discharge modes at atmospheric pressure  

SciTech Connect

Corona discharges in gases exist under several distinctive forms. In this paper, a survey study has been made of ac corona discharge modes generated in some different gases fed in a wire-duct reactor with a constant rate of flowing at atmospheric pressure. The properties of different corona modes are analyzed under some condition transitions from Trichel pulses to a steady glow. In the course of the presented experimental work, numerous apparent contradictions with earlier observations necessitated further study and are given to provide more information on the physical mechanisms of the ac corona discharges. Furthermore, we have gained insight into some new technologies and applications of the environmentally friendly corona and plasma discharges.

El-Koramy, Reda Ahmed; Yehia, Ashraf; Omer, Mohamed [Department of Physics, Faculty of Science, Assiut University, 71516 Assiut (Egypt)

2011-02-15

275

Liquid Sampling-Atmospheric Pressure Glow Discharge Ionization Source for Elemental Mass Spectrometry  

SciTech Connect

A new, low power ionization source for elemental MS analysis of aqueous solutions is described. The liquid sampling-atmospheric pressure glow discharge (LSAPGD) operates by a process wherein the surface of the liquid emanating from a 75 ?m i.d. glass capillary acts as the cathode of the direct current glow discharge. Analytecontaining solutions at a flow rate of 100 ?L min-1 are vaporized by the passage of current, yielding gas phase solutes that are subsequently ionized in the < 5 W (maximum of 60 mA and 500 V), ~1 mm3 volume, plasma. The LS-APGD is mounted in place of the normal electrospray ionization source of a Thermo Scientific Exactive orbitrap mass spectrometer system. Basic operating characteristics are described, including the role of discharge power on mass spectral composition, the ability to obtain ultra-high resolution elemental isotopic patterns, and preliminary limits of detection attainable based on the injection of aliquots of multielement standards. While much optimization remains, it is believed that the LS-APGD may present a practical alternative to high-powered (>1 kW) plasma sources typically employed in elemental mass spectrometry, particularly for those cases where costs, operational overhead, and simplicity considerations are important.

Marcus, R. Kenneth; Quarles, C. Derrick; Barinaga, Charles J.; Carado, Anthony J.; Koppenaal, David W.

2011-04-01

276

Growth of tungsten nanoparticles in direct-current argon glow discharges  

NASA Astrophysics Data System (ADS)

The growth of nanoparticles from the sputtering of a tungsten cathode in DC argon glow discharges is reported. The study was performed at fixed argon pressure and constant discharge current. The growth by successive agglomerations is evidenced. First, tungsten nanocrystallites agglomerate into primary particles, the most probable size of which being ˜30 nm. Primary particles of this size are observed for all plasma durations and always remain the most numerous in the discharge. Primary particles quickly agglomerate to form particles with size up to ˜150 nm. For short plasma duration, log-normal functions describe accurately the dust particle size distributions. On the contrary, for long discharge durations, a second hump appears in the distributions toward large particle sizes. In the meantime, the discharge voltage, electron density, and emission line intensities strongly evolve. Their evolutions can be divided in four separate phases and exhibit unusual distinctive features compared to earlier observations in discharges in which particles were growing. The evolution of the different parameters is explained by a competition between the surface state of the tungsten cathode and the influence of the growing nanoparticles. The differences with sputtering glow discharges and chemically active plasmas suggest that the nanoparticle growth and its influence on discharge parameters is system and material dependent.

Kishor Kumar, K.; Couëdel, L.; Arnas, C.

2013-04-01

277

ON FIFTY YEARS OF THE NEUTRON DISCOVERY: Glow discharge in a gas flow  

NASA Astrophysics Data System (ADS)

The status of research on glow discharges in a gas flow, used in pumping fast-flow lasers, is reviewed. Systematic study of this discharge began about 10 years ago. This discharge form, according to a number of properties (current flow mechanism, nature of the development of instabilities, etc.), differs considerably from the well-studied glow discharge in tubes. One of the distinguishing features of such a discharge is the negligibly small role of ionization in a large part of the positive column, so that narrow regions near the electrodes contribute most of the positive ions and electrons. Negative ions, which compensate the charge of the positive column, are generated in its volume. The discharge turns out to be weakly inhomogeneous in the direction from the cathode to the anode and the ion currents can form an appreciable part of the total current. These facts have not yet been sufficiently widely discussed in reviews and monographs. In this review, results of experimental investigations of the mechanism of current flow, energy balance, plasmochemical processes, and discharge instabilities are presented, the mathematical models used in their analysis are analyzed, and the possibilities for increasing the stability and efficiency of the discharge in fast-flow lasers are examined.

Velikhov, E. P.; Golubev, V. S.; Pashkin, S. V.

1982-05-01

278

A Study of Nonlocal Ionization Process in the Thermionic Cathode - Glow Discharge Model  

NASA Astrophysics Data System (ADS)

During high intensity discharge (HID) lamp starting, high cathode fall voltage (200-300 V) observed in the cold cathode glow discharge phase, collapses to 30-70 volts as the cathode heated up to thermionic emitting temperature. This low voltage thermionic arc phase can last up to minutes as the plasma transit to steady state arc discharge closed to local thermodynamic equilibrium. The thermionic arc phase plays an important role in the overall HID lamp starting and lumen maintenance. The hot cathode glow discharge model is being re-examined footnote Byszewski W. W., Gregor P. D., Budinger A. B., Li Y. M., "Tungsten radiation measurement during starting of metal halide lamps", J. Ill. Eng. Soc., Vol. 21, p. 85(1992) by including the nonlocal, nonequilibrium ionization process due to the thermionic emitted electrons gaining energy from the cathode fall. The cathode energy balance equation describing the hot cathode and thermionic emission will be set up. Various components of cathode heating power due to discharge ions, electrons, and neutrals will be analysis. The possible role of back diffusion of high energy plasma electron in cathode heating will be studied. Based on the numerical solution of the coupled plasma-cathode system, the current-voltage characteristics are determined and the change in cathode emission charateristics from secondary to thermionic will be explored. The effect of nonlocal ionization of thermionic emitted electrons on current-voltage characteristics of the plasma-cathode system will be presented.

Li, Yan-Ming

1998-10-01

279

Particle beam sample introduction into glow discharge plasmas for speciation analysis  

NASA Astrophysics Data System (ADS)

This paper reviews the use of the particle beam (PB) as a transport-type interface for the introduction of liquid samples into glow discharge (GD) plasmas. Emphasis is placed on the PB interface as a coupling for liquid chromatography (LC) with optical emission spectroscopy (OES) and mass spectrometry (MS) detection methods. Advantages and disadvantages of the particle beam sample introduction for LC-MS and LC-OES as well as a comparison with other interfaces (i.e. moving belt) are covered. Fundamental aspects of the particle beam such as solvent removal and analyte delivery are highlighted. Furthermore, the development of the particle beam interface is discussed regarding its potential for providing "comprehensive speciation" analysis of solution-phase samples. Specifically, the particle beam/hollow cathode-optical emission spectroscopy (PB/HC-OES) technique provides information towards metal and non-metals determinations as well molecular species identification of organic compounds, organometallics, and small biomolecules via empirical formulae determinations. Particle beam-glow discharge mass spectrometry (PB/GDMS) also provides molecular species information through fragmentation pattern analysis of plasma-produced mass spectra that are similar in structure to electron impact (EI) sources. The evolving capabilities of the PB/GD couplings deliver analytical information that is not available from any other spectrochemical source. The technique has relevance to an incredible range of analytical applications and warrants further investigation by other researchers and instrument manufacturers.

Brewer, Tim M.; Castro, Joaudimir; Marcus, R. Kenneth

2006-02-01

280

Modeling of the spatiotemporal behavior of an argon glow discharge at atmospheric pressure  

NASA Astrophysics Data System (ADS)

The spatiotemporal behavior of gas discharges is described by means of a fluid model which comprises the coupled set of balance equations for the densities of electrons, ions and neutral particles, the electron energy balance equation as well as Poisson's equation for the electric potential. This system of equations is numerically solved using a stabilized finite element method. The discharge voltage required for the solution of Poisson's equation is determined from the solution of the external electric circuit equations taking into account the time-dependent capacity and resistance of the plasma. In the present contribution first results related to an argon plasma at atmospheric pressure in a discharge configuration designed to generate small homogeneous high-pressure glow dischargesfootnotetextW. B"otticher et al., Appl. Phys. B 54 (1992) 295 are presented. Main features of the temporal evolution of the discharge, which can be divided into Townsend, ignition, quasi-steady-state and recombination phase, are discussed. It is found that the cathode-fall thickness and current density in the quasi-steady state are of the order of the values given by the similarity laws for normal glow discharges.

Becker, Markus M.; Loffhagen, Detlef

2009-10-01

281

Effect of volume and surface charges on discharge structure of glow dielectric barrier discharge  

SciTech Connect

The effect of volume and surface charges on the structure of glow dielectric barrier discharge (DBD) has been investigated numerically by using two-dimensional (2D) fluid modeling. The local increase of volume or surface charges induces a kind of activation-inhibition effect, which enhances the local volume discharge and inhibits the discharge in neighborhoods, resulting in non-uniform discharge. The activation-inhibition effect due to the non-uniform volume and/or surface charges depends on the non-uniformity itself and the applied voltage. The activation-inhibition of non-uniform charges has different effects on the volume charges and the accumulated surface charges. The distribution of remaining free charges (seed electrons) in volume at the beginning of voltage pulse plays a key role for the glow DBD structure, resulting in a patterned DBD, when the seed electrons are non-uniform at higher frequency and moderate voltage or uniform DBD, when the seed electrons are uniform at lower frequency or high voltage. The distribution of surface charges is not the determining factor but a result of the formed DBD structure.

Xu, Shao-Wei; He, Feng; Wang, Yu; Li, Lulu; Ouyang, Ji-Ting [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)] [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)

2013-08-15

282

Effect of surface modification of high-density polyethylene by direct current and radio frequency glow discharge on wetting and adhesion characteristics  

NASA Astrophysics Data System (ADS)

The present investigation aims to optimize the process parameters of Direct Current (DC) and Radio Frequency (RF) glow discharge treatment through air in terms of discharge power and time of exposure for the surface modification of high-density polyethylene (HDPE) sheet, for attaining best adhesive joint of the polymer to mild steel. In order to estimate the extent of surface modification, the surface energies of the polymer surfaces exposed to glow discharge have been determined by measuring contact angles using two standard test liquids of known surface energies. It is observed that at a given power level of DC glow discharge, surface energy and its polar component increase with increasing exposure time, attaining a maximum and then decreasing. In the case of RF glow discharge, surface energy and its polar component increase with increasing exposure time and then saturate. Surface modification by DC glow discharge increases the surface energy of HDPE relatively more at a lower power compared to that observed for RF glow discharge. The dispersion component of surface energy remains almost unaffected. The surfaces have also been studied by electron spectroscopy for chemical analysis (ESCA) and energy-dispersive spectra (EDS). A significant oxygen peak is observed for surface-modified polymer as detected by ESCA and EDS. Lap shear tensile test of an adhesive (Araldite AY 105) joint of HDPE with mild steel has been carried out in optimizing the parameters of DC and RF glow discharge for maximum joint strength. When HDPE is exposed to DC glow discharge, improvement of adhesive joint strength of HDPE to mild steel is found to be by a factor more than 7. On the other hand, when HDPE is exposed to RF glow discharge, results in improvement of adhesive joint strength of HDPE to mild steel by a factor nearer to 7 are found. Thus, DC glow discharge is more capable for increasing wetting and adhesion characteristics of the polymer.

Bhowmik, S.; Chaki, T. K.; Ray, S.; Hoffman, F.; Dorn, L.

2004-03-01

283

Hereditary abnormalities in pigs L. OLLIVIER  

E-print Network

to a single autosomal recessive gene,5to one autosomal dominant gene and I to a sexlinked recessive gene in production traits compensating for the disadvantages due to the abnormality itself; this is for instance

Paris-Sud XI, Université de

284

Pinna abnormalities and low-set ears  

MedlinePLUS

... because they do not affect hearing. However, sometimes cosmetic surgery is recommended. Skin tags may be tied off, ... 5 years old. More severe abnormalities may require surgery for cosmetic reasons as well as for function. Surgery to ...

285

Report to Congress on abnormal occurrences  

SciTech Connect

Section 208 of the Energy Reorganization Act of 1974 identified an abnormal occurrence as an unscheduled incident or event that the Nuclear Regulatory Commission determines to be significant from the standpoint of public health or safety and requires a quarterly report of such events to be made to Congress. This report covers the period from October 1 through December 31, 1990. The report discusses five abnormal occurrences, none of which involved a nuclear power plant. Two involved significant overexposures to the hands of two radiographers, two involved medical therapy misadministrations, and one involved a medical diagnostic misadministration. No abnormal occurrences were reported by the Agreement States. The report also contains information that updates a previously reported abnormal occurrence. 8 refs.

Not Available

1991-03-01

286

Abnormal Glucose Levels Found in Transportation Accidents.  

National Technical Information Service (NTIS)

The Federal Aviation Administration's Office of Aviation Medicine (OAM) is responsible for the certification of pilots with diabetic conditions. Therefore, it is essential for OAM to monitor pilots involved in fatal accidents for abnormal glucose levels, ...

D. V. Canfield, A. K. Chaturvedi, H. K. Boren, S. J. H. Veronneau, V. L. White

2000-01-01

287

Structural abnormality of the carburized layer  

Microsoft Academic Search

1.The tendency toward abnormality is characterized by the rate of decomposition of austentite into ferrite at definite temperatures.2.The horophilic elements (AI, V, W, Mn) increase the tendency toward abnormality; the horophobic substances (Mn, Cr, Ni) are conducive to the formation of a normal structure.3.By selecting the chemical composition it is possible in the process of melting to control the degree

B. S. Natapov

1962-01-01

288

Cosmic Glows  

E-print Network

This is the obligatory Cosmic Microwave Background review. I discuss the current status of CMB anisotropies, together with some points on the related topic of the Far-Infrared Background. We have already learned a number of important things from CMB anisotropies. Models which are in good shape have: approximately flat geometry; cold dark-matter, plus something like a cosmological constant; roughly scale invariant adiabatic fluctuations; and close to Gaussian statistics. The constraints from the CMB are beginning to be comparable to those from other cosmological measurements. With a wealth of new data coming in, it is expected that CMB anisotropies will soon provide the most stringent limits on fundamental cosmological parameters, as well as probing high energy particle physics and the Dark Ages of astrophysics. Nudge, nudge. Wink, wink. Say no more.

Douglas Scott

1999-12-02

289

Glowing Flowers  

NSDL National Science Digital Library

Student teams learn about engineering design of green fluorescent proteins (GFPs) and their use in medical research, including stem cell research. They simulate the use of GFPs by adding fluorescent dye to water and letting a flower or plant to transport the dye throughout its structure. Students apply their knowledge of GFPs to engineering applications in the medical, environmental and space exploration fields. Due to the fluorescing nature of the dye, plant life of any color, light or dark, can be used â unlike dyes that can only be seen in visible light.

Integrated Teaching And Learning Program

290

42 CFR 37.54 - Notification of abnormal radiographic findings.  

Code of Federal Regulations, 2013 CFR

...abnormality of cardiac shape or size, tuberculosis, lung cancer, or any other significant abnormal findings other...abnormality of cardiac shape or size, tuberculosis, cancer, complicated pneumoconiosis, and any other...

2013-10-01

291

An overview of research using the one atmosphere uniform glow discharge plasma (OAUGDP) for sterilization of surfaces and materials  

Microsoft Academic Search

The medical, food processing, and heating, ventilating, and air conditioning industries are searching for improved pasteurization, disinfection, and sterilization technologies. Candidate techniques must deal with and overcome such problems as thermal sensitivity and destruction by heat, formation of toxic by-products, costs, and inefficiency in performance. We report the results of a plasma source, the One Atmosphere Uniform Glow Discharge Plasma

Thomas C. Montie; Kimberly Kelly-Wintenberg; J. Reece Roth

2000-01-01

292

Spectroscopic studies and rotational and vibrational temperature measurements of atmospheric pressure normal glow plasma discharges in air  

Microsoft Academic Search

DC normal glow (NG) discharges were created in atmospheric pressure air for a pin to plate type geometry. The rotational and vibrational temperatures of the discharge were measured by comparing modelled optical emission spectra with spectroscopic measurements from the discharge. The temperatures were measured as a function of discharge current, ranging from 50 µA to 30 mA, and discharge length,

David Staack; Bakhtier Farouk; Alexander F. Gutsol; Alexander A. Fridman

2006-01-01

293

Rotational and vibrational temperature measurements of atmospheric pressure normal glow plasma discharges in air, nitrogen, argon, and helium  

Microsoft Academic Search

Summary form only given. Atmospheric pressure DC normal glow discharges were created in air and other gases. The rotational and vibrational temperature of the discharge was measured by comparing optical emission spectra modeled using SPECAIR to spectroscopic measurements from the discharge using the 2nd positive system of N2. In air the temperatures were measured as a function of discharge current,

D. Staack; B. Farouk; A. Gutsol; A. Fridman

2006-01-01

294

The physics and phenomenology of One Atmosphere Uniform Glow Discharge Plasma (OAUGDP™) reactors for surface treatment applications  

Microsoft Academic Search

In this paper, we present data on the physics and phenomenology of plasma reactors based on the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP™) that are useful in optimizing the conditions for plasma formation, uniformity and surface treatment applications. It is shown that the real (as opposed to reactive) power delivered to a reactor is divided between dielectric heating of

J. Reece Roth; Jozef Rahel; Xin Dai; Daniel M. Sherman

2005-01-01

295

A study of internal oxidation in carburized steels by glow discharge optical emission spectroscopy and scanning electron microscopy  

Microsoft Academic Search

The internal oxidation of Cr-Mn carburizing steel was studied. Internal oxidation was induced using a commercial carburizing process. Sputter erosion coupled with glow discharge optical emission spectroscopy (GDOES) was used to determine the depth profile elemental distribution within the internal oxidation layer (

X. An; J. Cawley; W. M. Rainforth; L. Chen

2003-01-01

296

Application of Radio-Frequency Plasma Glow Discharge to Removal of Uranium Dioxide from Metal Surfaces  

SciTech Connect

Recent experiments have shown that radio-frequency (rf) plasma glow discharge using NF{sub 3} gas is an effective technique for the removal of uranium oxide from metal surfaces. The results of these experiments are analyzed to explain the measured dependence of the UO{sub 2} removal or etch rate on the NF{sub 3} gas pressure and the absorbed power in the plasma. The NF{sub 3} gas pressure in the experiments was varied from 10.8 to 40 Pa, and the deposited power in the plasma was varied from 25 to 210 W. The UO{sub 2} etch rate was strongly dependent on the absorbed power and, to a lesser extent, on the NF{sub 3} pressure and decreased exponentially with immersion time. At 210 W and 17 Pa, all detectable UO{sub 2} in the samples ({approx}10.6 mg each) was removed at the endpoint, whereas the initial etch rate was {approx}3.11 {mu}m/min. When the absorbed power was {<=}50 W, however, the etch rate was initially {approx}0.5 {mu}g/min and almost zero at the endpoint, with UO{sub 2} only partially etched. This self-limiting etching of UO{sub 2} at low power is attributed to the formation of nonvolatile intermediates UF{sub 2}, UF{sub 3}, UF{sub 4}, UF{sub 5}, UO{sub 2}F, and UO{sub 2}F{sub 2} on the surface. Analysis indicated that the accumulation of UF{sub 6} and, to a lesser extent, O{sub 2} near the surface partially contributed to the exponential decrease in the UO{sub 2} etch rate with immersion time. Unlike fluorination with F{sub 2} gas, etching of UO{sub 2} using rf glow discharge is possible below 663 K. The average etch rates of the amorphous UO{sub 2} in the NF{sub 3} experiments are comparable to the peak values reported in other studies for crystalline UO{sub 2} using CF{sub 4}/O{sub 2} glow discharge performed at {approx}150 to 250 K higher sample temperatures.

El-Genk, Mohamed S.; Saber, Hamed H. [University of New Mexico (United States)

2000-11-15

297

Energy balance of the bulk, Maxwellian electrons in spatially inhomogeneous negative-glow plasmas  

NASA Astrophysics Data System (ADS)

The energy balance of the Maxwellian (bulk) electrons is analyzed in spatially inhomogeneous negative-glow plasmas (NGP). The purpose is to give a comprehensive model which enables the electron temperature in the NGP to be predicted. Since the bulk of the electron distribution function (EDF) in the NGP is Maxwellian, the rates of many important plasma processes (e.g., ambipolar diffusion, recombination, stepwise processes), as well as the plasma potential, are controlled by the electron temperature. Knowledge of the electron temperature is thus of particular importance for such types of plasma. In order to calculate the EDF in the elastic energy range (slow electrons), a spatially inhomogeneous kinetic equation is employed, in which the electron-electron collision integral is fully incorporated. Owing to the complicated (nonlinear integro-differential) form of the electron-electron collision integral, the direct numerical solution of the full kinetic equation represents a difficult task. An efficient way to render the problem tractable consists in breaking the slow electrons up into two distinct groups, namely, the Maxwellian (trapped) and superthermal (untrapped) electrons. The parameters of the Maxwellian EDF can be found from the particle- and energy-balance equations. The superthermal EDF can be found from a reduced kinetic equation. The separation of the electron population into two groups allowed us to obtain an energy-balance equation for the Maxwellian (cold, trapped) electrons, which properly accounts for the most important physical mechanisms, such as heating due to Coulomb collisions with the superthermal (hot, untrapped) electrons. It is shown that the problem of finding the electron temperature in a weakly collisional NGP can be described correctly only at the kinetic level. In this situation, the use of the fluid approximation, in which the electron ensemble is treated in terms of its density and mean energy, results in a physically incorrect energy-balance equation. Furthermore, it is demonstrated that the ``nonlocal'' effects may be critical for the problem of finding the EDF in general, and the electron temperature in particular, so that the ``local'' (kinetic) models may also produce erroneous results. The principal terms in the energy-balance equation are identified, and this equation is simplified to allow a ready solution and implementation into a plasma code. The validity of the proposed model for predicting the electron temperature was confirmed by numerical calculations of the EDF from the full kinetic equation. The results of the paper can be applied to the NGP generated in direct-current glow discharges with planar or hollow cathodes, as well as to negative-glow-like plasmas, such as beam-generated and afterglow (decaying) plasmas.

Arslanbekov, Robert R.; Kudryavtsev, Anatoly A.

1998-11-01

298

p53 Abnormalities and Potential Therapeutic Targeting in Multiple Myeloma  

PubMed Central

p53 abnormalities are regarded as an independent prognostic marker in multiple myeloma. Patients harbouring this genetic anomaly are commonly resistant to standard therapy. Thus, various p53 reactivating agents have been developed in order to restore its tumour suppressive abilities. Small molecular compounds, especially, have gained popularity in its efficacy against myeloma cells. For instance, promising preclinical results have steered both nutlin-3 and PRIMA-1 into phase I/II clinical trials. This review summarizes different modes of p53 inactivation in myeloma and highlights the current p53-based therapies that are being utilized in the clinic. Finally, we discuss the potential and promise that the novel small molecules possess for clinical application in improving the treatment outcome of myeloma. PMID:25028664

Teoh, P. J.; Chng, W. J.

2014-01-01

299

The masculinized female and investigation of abnormal sexual development.  

PubMed

The congenital adrenal hyperplasias are the commonest cause of ambiguity of the external genitalia at birth, although sexual differentiation in these disorders is strictly normal. The masculinized genetic female is invariably the result of 21-hydroxylase deficiency. The molecular features are well characterized and the phenotypic correlates are generally concordant. Prenatal treatment by maternal dexamethasone administration can successfully prevent virilization of the external genitalia in an affected female fetus. Placental aromatase is a rare and recently characterized alternative cause of a masculinized female which should be considered in the absence of fetal adrenal hyperplasia and maternal androgen-secreting tumours. The investigation of abnormal sexual development requires an initial karyotype analysis and serum 17OH progesterone measurement to determine whether 21-hydroxylase deficiency is the likeliest cause. Thereafter, the presence of a 46,XY karyotype determines the mode of investigation according to androgen production and action. Obtaining appropriate samples for DNA, biochemical and immunohistochemical analyses is essential if the diagnostic yield for the investigation of abnormal sexual development is to be improved. PMID:9890067

Hughes, I A

1998-04-01

300

Degradation of Methyl Orange in Water by Contact Glow Discharge Electrolysis  

NASA Astrophysics Data System (ADS)

The degradation of methyl orange in a neutral phosphate buffer solution was investigated by means of contact glow discharge electrolysis (CGDE). The methyl oranges were degraded and eventually decomposed into inorganic carbon when CGDE was conducted under the applied DC voltage of 480 V and current of ca. 80 mA. As the intermediate products, some phenolic compounds were detected as well as carboxylic acids. Experimental results showed that the oxidation process followed the first-order reaction law. Based on the analysis of the ultraviolet (UV) spectra of the solution and the intermediate products from High Pressure Liquid Chromatography-Mass Spectrum (HPLC-MS), the reaction pathway was proposed. The attack of hydroxyl radicals was considered to be a key step to start the whole oxidation process.

Gong, Jianying; Cai, Weimin

2007-04-01

301

Analysis of glow discharges for understanding the process of film formation  

NASA Technical Reports Server (NTRS)

The physical and chemical processes which occur during the formation of different types of films in a variety of glow discharge plasmas are discussed. Emphasis is placed on plasma diagnostic experiments using spectroscopic methods, probe analysis, mass spectrometric sampling and magnetic resonance techniques which are well suited to investigate the neutral and ionized gas phase species as well as some aspects of plasma surface interactions. The results on metallic, semi-conducting and insulating films are reviewed in conjunction with proposed models and the problem encountered under film deposition conditions. It is concluded that the understanding of film deposition process requires additional experimental information on plasma surface interactions of free radicals and the synergetic effects where photon, electron and ion bombardment change the reactivity of the incident radical with the surface.

Venugopalan, M.; Avni, R.

1984-01-01

302

Mechanisms for the adhesion of silver to glow discharge sensitized perfluorinated ethylene propylene (PEP)  

NASA Technical Reports Server (NTRS)

Details are given for the deposition of silver onto FEP for a batch coater capable of handling 864 square inches at a time. The effectiveness of the glow discharge is shown to be optimum when the FEP faces the anode. Using solid state theory based upon the work function difference, and the heuristic assumption that the surface of FEP is populated with fluoride ions, it is argued that an anode sensitized surface develops states receptive to electron transfer from silver, whereas a cathode sensitized surface is polarized only, and as a result cannot permanently trap charge. Thermodynamic arguments given show that an order of magnitude of 10 to the 9th power electrons are transferred into states to a depth of 10 nm.

Schutt, J. B.; Gilchrist, W. H.; Paczkowski, F. N.

1972-01-01

303

PREPARATION OF CU-DOPED GLOW DISCHARGE POLYMER COATINGS FOR ICF APPLICATIONS  

SciTech Connect

OAK-B135 Copper doped polymer shells can provide a very useful diagnostic for fast ignition experiments currently being performed at various laboratories around the world. The low concentration copper dopant acts as an efficient x-ray source providing information on the physics of fast ignition. They have developed copper doped glow discharge (GDP) coatings suitable for such purposes. Copper acetylacetonate (CuAcAC), a solid at room temperature, was used in a heated jacket as the dopant source. They used this technique to fabricate thin ({approx} 5-7 {micro}m) GDP shells doped with {approx} 1 at% copper through the depolymerizable mandrel process for fast ignition experiments. The details of the experimental set up and the range and limitations of the technique are discussed.

NIKROO,A; CASTILLO,E; HILL,D.W; GREENWOOD,A.L.

2003-06-01

304

Attenuation of microwaves propagating through parallel-plate helium glow discharge at atmospheric pressure  

SciTech Connect

The experimental study of microwave-plasma interaction has been performed to demonstrate the transmission and attenuation of microwaves in atmospheric pressure glow discharge plasma. The cold-collisional plasma produced at atmospheric pressure can absorb the microwave energy because of its complex dielectric constant. The microwave of 10 GHz frequency was launched into the plasma and attenuation was measured as a function of electron plasma density, plasma thickness, electron-neutral collision frequency, etc. It was observed that the attenuation significantly depends on electron plasma density and thickness. The microwave attenuation measurement was also used as a diagnostic to estimate electron plasma density. It was validated by optical emission spectroscopic measurements with helium line intensity ratio method. Both the methods show good agreement.

Srivastava, A. K.; Prasad, G.; Atrey, P. K.; Kumar, Vinay [Institute for Plasma Research, Bhat, Near Indira Bridge, Gandhinagar, Gujarat 382428 (India)

2008-02-01

305

Sub-microsecond pulsed atmospheric glow discharges with and without dielectric barrier  

SciTech Connect

The discharge characteristics and mechanism of glow discharges in atmospheric pressure helium excited by repetitive voltage pulses with and without dielectric barriers are numerically studied using a one-dimensional self-consistent fluid model. The waveforms of discharge current density show that one discharge event occurs during the voltage pulse with bare electrodes and two distinct discharge events happen at the rising and falling phases of voltage pulse with dielectric barrier electrodes, respectively. The spatial profiles of electron and electric field at the time instant of discharge current peak reveal that the electrons are trapped in the plasma bulk with bare electrodes, while the electrons are accumulated in the region between the sheath and plasma bulk with dielectric barrier electrodes. Furthermore, the spatio-temporal evolution of electron density and mean electron energy clearly demonstrate the dynamics of discharge ignition, especially the temporal evolution of sheath above the instantaneous cathode.

Song Shutong [College of Science, Donghua University, Shanghai 201620 (China); Guo Ying; Zhang Jie; Zhang Jing; Shi, J. J. [College of Science, Donghua University, Shanghai 201620 (China); Member of Magnetic Confinement Fusion Research Center, Ministry of Education of the People's Republic of China, Shanghai 201620 (China); Choe, Wonho [Department of Physics, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2012-12-15

306

Effect of metastable neon atoms in a positive column of glow discharge with dust particles  

NASA Astrophysics Data System (ADS)

The diffusion/drift model of the positive column of glow discharge in neon was used for the analysis of the role of neon metastable atoms in the interaction between neon plasma and dust particles. The radial profiles of electrons and metastable atoms were simulated in the typical range of neon pressure and discharge current where dust particles may form dense dust structures changing the plasma properties. The results showed the nonlocal effect of dust particles on the plasma composition. Within the dust structure, the metastable atom concentration was shown to be higher than in the discharge without dust particles at the same discharge parameters; the ratio of concentrations of metastable atoms and electrons may increase with increasing dust particle concentration in a certain range of discharge parameters. The partial contribution of metastable atoms to the ionization was found to be higher than their losses on the surface of dust particles and increased when the gas pressure was increased.

Shumova, V. V.; Polyakov, D. N.; Vasilyak, L. M.

2014-12-01

307

Isotopic analysis of uranium using glow discharge optogalvanic spectroscopy and diode lasers  

SciTech Connect

A hollow cathode glow discharge has been coupled with tunable lasers for isotopically selective excitation of gaseous uranium atoms produced by cathodic sputtering. A CW argon ion laser-pumped titanium:sapphire ring laser and a semiconductor diode laser were employed. Optogalvanic detection of the discharge atom population allowed identification of [sup 235]U at depleted, natural, and enriched abundances in uranium metal and uranium oxide samples based on the spectral signatures of two transitions. Isotope ratio measurements were precise from run to run (internal precision) to better than +1% relative standard deviation at 1[sigma]; external precision (sample to sample) was on the order of [+-]3% relative standard deviation at 1[sigma]. As in mass spectrometry, the most accurate analysis will be obtained when a bias correction is employed to correct for day to day variations in the laser and discharge conditions. 24 refs., 4 figs., 1 tab.

Barshick, C.M.; Shaw, R.W.; Young, J.P.; Ramsey, J.M. (Oak Ridge National Lab., TN (United States))

1994-12-01

308

Experimental And Theoretical Studies On The Characteristics Of Low-Pressure Glow Discharge With Liquid Cathode  

NASA Astrophysics Data System (ADS)

The characteristics of low-pressure air glow discharge with liquid cathode (electrolytic cathode low-pressure discharge, ELCLPD) has been investigated. Distilled water was utilized as a cathode. The electric field strength, gas temperature as well as emission intensity of some bands of N2(C3?u?B3 ?g) were measured at pressure from 76 to 760 torr at fixed discharge current of 40 mA. Based upon these data, the reduced electric field strength, E/N, effective vibrational temperatures for N2(C3?u, X1Sg+) and rotational temperatures for N2(X1Sg+) were investigated. The electron energy distribution function (EEDF) and some electron parameters (average energy, electron density) were obtained on the base of numerical solution of the Boltzmann kinetic equation.

Shutov, D.; Ivanov, A.; Smirnov, S.; Rybkin v.

2010-07-01

309

Self-consistent kinetic model of the cathode fall of a glow discharge  

NASA Astrophysics Data System (ADS)

The electrons in the cathode-fall (CF) region of a helium dc glow discharge have been modeled at the kinetic level with a self-consistent electric field using a ``convective-scheme'' (CS) (propagator or Green's-function) solution method. The CS is both straightforward to implement and numerically efficient. CS electron calculations using one spatial and two velocity variables are shown to match Monte Carlo simulations of swarms in uniform E/N and in the CF. The CS predictions are also shown to match experimental swarm results. A self-consistent CF solution is obtained through a slow relaxation of the electric field to that indicated by Poisson's equation. The electric field configuration as predicted by the CS agrees well with optogalvanic measurements. The discussion emphasizes both the physical nature of, and the difficulties associated with, a self-consistent-field calculation.

Sommerer, T. J.; Hitchon, W. N. G.; Lawler, J. E.

1989-06-01

310

An efficient numerical algorithm for simulating a two-dimensional glow discharge  

NASA Astrophysics Data System (ADS)

A numerical algorithm of the second approximation order with respect to the space variables for simulating a two-dimensional elevated pressure glow discharge in the framework of the drift-diffusion approximation is presented. A specific feature of this algorithm is the use of the Laplace resolving operator for the solution of the system of grid equations. This makes it possible to ensure the convergence of the solution in strong grid norms. Mathematical aspects of the statement of the differential-difference and finite difference problems (solvability, nonnegativity, approximation, stability, and convergence) are discussed, and bounds on the norms of the corresponding differential and difference operators that are required for constructing an optimal iterative process are obtained.

Islamov, R. Sh.

2006-11-01

311

Generation and Control of Electrolyte Cathode Atmospheric Glow Discharges using Miniature Gas Flow  

NASA Astrophysics Data System (ADS)

Stable electrolyte cathode atmospheric dc glow microdischarges were generated by using a miniature helium gas flow from a nozzle electrode in air. We developed two schemes to control the temporal evolution of the discharge and the interaction between the discharge column and the ambient air. The vaporization of electrolyte solutions takes place and affects the discharge characteristics. It takes time from the start of the discharge. Therefore the discharge was controlled by applying pulse modulated dc voltages. If the voltage was dropped down to zero before the vaporization, the gas discharge developed without the ionization of the components of solution. The helium gas discharge without air developed when the nozzle electrode was placed in a glass capillary. This was confirmed by examining the change in pH of the solution, which usually decreased owing to the generation of nitrogen oxides in the discharge in air.

Shirai, Naoki; Nakazawa, Masato; Ibuka, Shinji; Ishii, Shozo

312

Schizophrenia and abnormal brain network hubs  

PubMed Central

Schizophrenia is a heterogeneous psychiatric disorder of unknown cause or characteristic pathology. Clinical neuroscientists increasingly postulate that schizophrenia is a disorder of brain network organization. In this article we discuss the conceptual framework of this dysconnection hypothesis, describe the predominant methodological paradigm for testing this hypothesis, and review recent evidence for disruption of central/hub brain regions, as a promising example of this hypothesis. We summarize studies of brain hubs in large-scale structural and functional brain networks and find strong evidence for network abnormalities of prefrontal hubs, and moderate evidence for network abnormalities of limbic, temporal, and parietal hubs. Future studies are needed to differentiate network dysfunction from previously observed gray- and white-matter abnormalities of these hubs, and to link endogenous network dysfunction phenotypes with perceptual, behavioral, and cognitive clinical phenotypes of schizophrenia. PMID:24174905

Rubinov, Mikail; Bullmore, Ed.

2013-01-01

313

Spectroscopic study of hydrogen rotational, vibrational and translational temperatures in a hollow cathode glow discharge  

NASA Astrophysics Data System (ADS)

Hydrogen hollow cathode glow discharges (HCGD) have been extensively used for study of fundamental discharge processes as well as for wide variety of applications. For instance, recently, this type of discharge was utilized for producing hydrogen by reforming natural gas (da Silva et al. 2006). The translational or gas kinetic temperature in gas discharges is a parameter of utmost importance in the field of plasma chemistry while vibrationally excited neutral hydrogen molecules play significant role in the chemistry of weakly ionized hydrogen plasmas. This is why the modeling of cold, reactive hydrogen plasma includes rotational and vibrational energy of the hydrogen molecule. This is the reason why we study HC discharge parameters like rotational, translational and vibrational temperature. Several diagnostic techniques are developed to determine gas kinetic temperature T_g like coherent anti-stokes Raman scattering (CARS), laser-induced fluorescence (LIF) and optical emission spectroscopy (OES). Here we selected OES. This diagnostic technique provides information about atom, molecule and ion density in excited and ground state, as well as rotational, vibrational, and gas temperature including the excitation temperature of certain group of excited levels. The technique is applied for measurements of the rotational T_rot, vibrational T_vib and determines translational temperatures in a hollow cathode glow discharge in hydrogen. The rotational temperature of excited electron energy levels is determined from the Boltzmann plot of intensities of rotational moleculelar hydrogen lines belonging to Fulcher-alpha diagonal bands. Following procedure described elsewhere (Astashkevich et al. 2006) the temperature of ground state rovibronic levels is evaluated. The constrains of rotational temperature are discussed in detail. The vibrational temperature is also determined, but from the relative intensities of the H_2 Fulcher-alpha diagonal bands. The dependence of these temperatures and their radial distribution within HC upon HC wall temperature was determined and discussed (Majstorovic et al. 2007).

Majstorovic, G. Lj.

2008-07-01

314

Familial congenital symmastia: ultrastructurally abnormal breast tissue.  

PubMed

Reports about congenital symmastia and its surgical treatment are few. We report two patients - a mother and daughter - with congenital symmastia in whom breast and fatty tissue was found to be mobile adhering poorly to the chest wall. Although histological examination showed no abnormality of the tissue bridge between the breasts, ultrastructural investigation of breast tissue (including Cooper's ligaments) showed an abnormal arrangement of collagen fibres. Satisfying aesthetic results were achieved by resection of excess soft tissue in the cleavage area through a submammary incision and fixation of the skin with subcutaneous interrupted sutures to the sternal periosteum. PMID:19995254

Piza-Katzer, Hildegunde; Engelhardt, Timm Oliver; Steiner, Hans-Jörg; Zelger, Bettina

2009-01-01

315

Hemorheological abnormalities in human arterial hypertension  

NASA Astrophysics Data System (ADS)

Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the pathophysiology of arterial hypertension and its vascular complications.

Lo Presti, Rosalia; Hopps, Eugenia; Caimi, Gregorio

2014-05-01

316

Normal and abnormal human vestibular ocular function  

NASA Technical Reports Server (NTRS)

The major motivation of this research is to understand the role the vestibular system plays in sensorimotor interactions which result in spatial disorientation and motion sickness. A second goal was to explore the range of abnormality as it is reflected in quantitative measures of vestibular reflex responses. The results of a study of vestibular reflex measurements in normal subjects and preliminary results in abnormal subjects are presented in this report. Statistical methods were used to define the range of normal responses, and determine age related changes in function.

Peterka, R. J.; Black, F. O.

1986-01-01

317

Corpus Callosum Abnormalities and their Association with Psychotic Symptoms in Patients with Schizophrenia  

PubMed Central

Background Whilst the neuroanatomical underpinnings of the functional brain disconnectivity observed in patients with schizophrenia remain elusive, white matter fiber bundles of the brain are a likely candidate given that they represent the infrastructure for long-distance neural communication. Methods This study investigated for diffusion abnormalities in 19 patients with chronic schizophrenia (SZ), relative to 19 matched controls, across tractography-defined segments of the Corpus Callosum. Diffusion-weighted images were acquired with 51 non-collinear gradients on a 3T scanner (1.7mm isotropic voxels). The Corpus Callosum was extracted by means of whole-brain tractography and automated fiber-clustering, and was parcellated into six segments on the basis of fiber trajectories. The diffusion indices of Fractional Anisotropy (FA) and Mode were calculated for each segment. Results Relative to the healthy controls, the SZ patients exhibited Mode increases in the Parietal fibers, suggesting a relative absence of crossing fibers. SZ patients also exhibited FA reductions in the Frontal fibers, which were underpinned by increased in Radial Diffusivity, consistent with myelin abnormalities. Significant correlations were observed between patients' degree of Reality Distortion and their FA and Radial Diffusivity, such that the most severely psychotic patients were the least abnormal in terms of their Frontal fiber diffusivity. Conclusions The SZ patients exhibited a variety of diffusion abnormalities in the Corpus Callosum, which were related to the severity of their psychotic symptoms. To the extent that diffusion abnormalities influence axonal transmission velocities, these results provide support for those theories that emphasize neural timing abnormalities in the etiology of schizophrenia. PMID:20494336

Whitford, Thomas J.; Kubicki, Marek; Schneiderman, Jason S.; O'Donnell, Lauren J.; King, Rebecca; Alvarado, Jorge L.; Khan, Usman; Markant, Douglas; Nestor, Paul G.; Niznikiewicz, Margaret; McCarley, Robert W.; Westin, Carl-Fredrik; Shenton, Martha E.

2010-01-01

318

Gastric emptying abnormal in duodenal ulcer  

SciTech Connect

To investigate the possibility that an abnormality of gastric emptying exists in duodenal ulcer and to determine if such an abnormality persists after ulcer healing, scintigraphic gastric emptying measurements were undertaken in 16 duodenal ulcer patients before, during, and after therapy with cimetidine; in 12 patients with pernicious anemia, and in 12 control subjects. No difference was detected in the rate or pattern of gastric emptying in duodenal ulcer patients before and after ulcer healing with cimetidine compared with controls, but emptying of the solid component of the test meal was more rapid during treatment with the drug. Comparison of emptying patterns obtained in duodenal ulcer subjects during and after cimetidine treatment with those obtained in pernicious anemia patients and controls revealed a similar relationship that was characterized by a tendency for reduction in the normal differentiation between the emptying of solid and liquid from the stomach. The similarity in emptying patterns in these groups of subjects suggests that gastric emptying of solids may be influenced by changes in the volume of gastric secretion. The failure to detect an abnormality of gastric emptying in duodenal ulcer subjects before and after ulcer healing calls into question the widespread belief that abnormally rapid gastric emptying is a feature with pathogenetic significance in duodenal ulcer disease.

Holt, S.; Heading, R.C.; Taylor, T.V.; Forrest, J.A.; Tothill, P.

1986-07-01

319

Psychology Faculty Perceptions of Abnormal Psychology Textbooks  

ERIC Educational Resources Information Center

The problem. The purpose of the current study was to investigate the perceptions and opinions of psychology professors regarding the accuracy and inclusiveness of abnormal psychology textbooks. It sought answers from psychology professors to the following questions: (1) What are the expectations of the psychology faculty at a private university of…

Rapport, Zachary

2011-01-01

320

ADEPT - Abnormal Doppler Enteral Prescription Trial  

Microsoft Academic Search

BACKGROUND: Pregnancies complicated by abnormal umbilical artery Doppler blood flow patterns often result in the baby being born both preterm and growth-restricted. These babies are at high risk of milk intolerance and necrotising enterocolitis, as well as post-natal growth failure, and there is no clinical consensus about how best to feed them. Policies of both early milk feeding and late

Alison Leaf; Jon Dorling; Steve Kempley; Kenny McCormick; Paul Mannix; Peter Brocklehurst

2009-01-01

321

Motor Control Abnormalities in Parkinson's Disease  

E-print Network

Motor Control Abnormalities in Parkinson's Disease Pietro Mazzoni, Britne Shabbott, and Juan Camilo York 10032 Correspondence: pm125@columbia.edu The primary manifestations of Parkinson's disease control processes. In the case of Parkinson's disease, movement slowness, for example, would be explained

322

Emergency Abnormal Conditions 1. Bomb Threat  

E-print Network

1 Emergency Abnormal Conditions 1. Bomb Threat a. Bomb threats usually occur by telephone. b. Try OR PACKAGE OR MOVE IT IN ANY WAY! #12;UNIVERSITY OF TENNESSEE SPACE INSTITUTE BOMB THREAT CALL FORM: ___________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ QUESTIONS TO ASK THE CALLER CONCERNING THE BOMB Who are you

Davis, Lloyd M.

323

Imaging management of palpable breast abnormalities.  

PubMed

OBJECTIVE. Women commonly present to imaging departments with a palpable breast abnormality. However, widespread confusion remains regarding the most appropriate sequence and extent of imaging required. The purpose of this article is to discuss the evidence informing current management guidelines for the care of patients with palpable breast abnormalities. CONCLUSION. Ultrasound is a highly effective imaging tool for guiding effective evaluation of women with palpable breast abnormalities and should be used for all women with suspicious findings at clinical breast examination. The exception is cases in which mammography shows a clearly benign correlate or a normal, fatty area of breast tissue in the location of the palpable finding. Breast ultrasound should be the primary imaging tool for women with palpable lumps who are pregnant, lactating, or younger than 30 years. For women 40 years old and older, mammography, followed in most cases by ultrasound, is recommended. For women 30-39 years old, ultrasound or mammography may be performed first at the discretion of the radiologist or referring provider. There is little to no role for breast MRI or other advanced imaging technologies in the routine diagnostic evaluation of palpable breast abnormalities. PMID:25341156

Lehman, Constance D; Lee, Amie Y; Lee, Christoph I

2014-11-01

324

Emergency Abnormal Conditions Injury and Illness  

E-print Network

1 Emergency Abnormal Conditions Injury and Illness a. If you become aware of a seriously ill with the person until the police or emergency medical personnel arrive. (5) If the injured person is an employee immediately and contact the HR Office at 393-7226 before seeking medical treatment. c. The `Accident Report

Davis, Lloyd M.

325

NEW RESEARCH Abnormal Amygdalar Activation and  

E-print Network

of the most disabling symptoms associated with attention-deficit/hyperactivity disorder (ADHD). We aimedNEW RESEARCH Abnormal Amygdalar Activation and Connectivity in Adolescents With Attention- Deficit/Hyperactivity Words: ADHD, amygdala, effective connectivity, fear, stimulant medication A lthough attention-deficit/hyperactivity

326

Challenges in Emergency and Abnormal Checklist Design  

E-print Network

and Abnormal Checklist Design Smoke, Fire, and Fumes Checklists and Procedures #12;Smoke, Fire, and Fumes of fires are ignited, fed, and spread · Regulations, Advisory Circulars, etc. #12;Smoke, Fire, and Fumes Checklists and Procedures Ambiguity of cues / level of certainty about situation Conflicting warnings / cues

327

ORIGINAL ARTICLE Clinical characterization of cardiovascular abnormalities  

E-print Network

: As affected animals increased in age, more cardiac abnormalities were found with increasing severity not recognized. MPS I and MPS VI cats have similar cardiovascular findings to those seen in children and constitute important models for testing new MPS therapies. Abbreviations 2D two-dimensional ECG

Ponder, Katherine P.

328

ORIGINAL ARTICLE Prevalence of Specific Gait Abnormalities  

E-print Network

ORIGINAL ARTICLE Prevalence of Specific Gait Abnormalities in Children With Cerebral Palsy Influence of Cerebral Palsy Subtype, Age, and Previous Surgery Tishya A. L. Wren, PhD,* Susan Rethlefsen, PT. These findings provide important information for counsel- ing ambulatory children with cerebral palsy

Valero-Cuevas, Francisco

329

Neuropsychological Abnormalities in Schizophrenia and Major Mood  

E-print Network

Neuropsychological Abnormalities in Schizophrenia and Major Mood Disorders: Similarities in schizophrenia. This work has led to an increased emphasis on identifying and evaluating treatments that enhance cognition in schizophrenia, with the hope that this would translate into a better quality of life

330

Motor Control Abnormalities in Parkinson's Disease  

PubMed Central

The primary manifestations of Parkinson’s disease are abnormalities of movement, including movement slowness, difficulties with gait and balance, and tremor. We know a considerable amount about the abnormalities of neuronal and muscle activity that correlate with these symptoms. Motor symptoms can also be described in terms of motor control, a level of description that explains how movement variables, such as a limb’s position and speed, are controlled and coordinated. Understanding motor symptoms as motor control abnormalities means to identify how the disease disrupts normal control processes. In the case of Parkinson’s disease, movement slowness, for example, would be explained by a disruption of the control processes that determine normal movement speed. Two long-term benefits of understanding the motor control basis of motor symptoms include the future design of neural prostheses to replace the function of damaged basal ganglia circuits, and the rational design of rehabilitation strategies. This type of understanding, however, remains limited, partly because of limitations in our knowledge of normal motor control. In this article, we review the concept of motor control and describe a few motor symptoms that illustrate the challenges in understanding such symptoms as motor control abnormalities. PMID:22675667

Mazzoni, Pietro; Shabbott, Britne; Cortes, Juan Camilo

2012-01-01

331

William McDougall and abnormal psychology  

Microsoft Academic Search

In William McDougall psychology had a staunch systematist able to integrate the abnormal and the normal within a single conceptual whole. He was not greatly interested in the classification of mental diseases, except as he found it necessary to consider \\

J. Q. Holsopple

1939-01-01

332

Esophageal motility abnormalities in gastroesophageal reflux disease.  

PubMed

Esophageal motility abnormalities are among the main factors implicated in the pathogenesis of gastroesophageal reflux disease. The recent introduction in clinical and research practice of novel esophageal testing has markedly improved our understanding of the mechanisms contributing to the development of gastroesophageal reflux disease, allowing a better management of patients with this disorder. In this context, the present article intends to provide an overview of the current literature about esophageal motility dysfunctions in patients with gastroesophageal reflux disease. Esophageal manometry, by recording intraluminal pressure, represents the gold standard to diagnose esophageal motility abnormalities. In particular, using novel techniques, such as high resolution manometry with or without concurrent intraluminal impedance monitoring, transient lower esophageal sphincter (LES) relaxations, hypotensive LES, ineffective esophageal peristalsis and bolus transit abnormalities have been better defined and strongly implicated in gastroesophageal reflux disease development. Overall, recent findings suggest that esophageal motility abnormalities are increasingly prevalent with increasing severity of reflux disease, from non-erosive reflux disease to erosive reflux disease and Barrett's esophagus. Characterizing esophageal dysmotility among different subgroups of patients with reflux disease may represent a fundamental approach to properly diagnose these patients and, thus, to set up the best therapeutic management. Currently, surgery represents the only reliable way to restore the esophagogastric junction integrity and to reduce transient LES relaxations that are considered to be the predominant mechanism by which gastric contents can enter the esophagus. On that ground, more in depth future studies assessing the pathogenetic role of dysmotility in patients with reflux disease are warranted. PMID:24868489

Martinucci, Irene; de Bortoli, Nicola; Giacchino, Maria; Bodini, Giorgia; Marabotto, Elisa; Marchi, Santino; Savarino, Vincenzo; Savarino, Edoardo

2014-05-01

333

Craniofacial abnormalities among patients with Edwards Syndrome  

PubMed Central

OBJECTIVE To determine the frequency and types of craniofacial abnormalities observed in patients with trisomy 18 or Edwards syndrome (ES). METHODS This descriptive and retrospective study of a case series included all patients diagnosed with ES in a Clinical Genetics Service of a reference hospital in Southern Brazil from 1975 to 2008. The results of the karyotypic analysis, along with clinical data, were collected from medical records. RESULTS: The sample consisted of 50 patients, of which 66% were female. The median age at first evaluation was 14 days. Regarding the karyotypes, full trisomy of chromosome 18 was the main alteration (90%). Mosaicism was observed in 10%. The main craniofacial abnormalities were: microretrognathia (76%), abnormalities of the ear helix/dysplastic ears (70%), prominent occiput (52%), posteriorly rotated (46%) and low set ears (44%), and short palpebral fissures/blepharophimosis (46%). Other uncommon - but relevant - abnormalities included: microtia (18%), orofacial clefts (12%), preauricular tags (10%), facial palsy (4%), encephalocele (4%), absence of external auditory canal (2%) and asymmetric face (2%). One patient had an initial suspicion of oculo-auriculo-vertebral spectrum (OAVS) or Goldenhar syndrome. CONCLUSIONS: Despite the literature description of a characteristic clinical presentation for ES, craniofacial alterations may be variable among these patients. The OAVS findings in this sample are noteworthy. The association of ES with OAVS has been reported once in the literature. PMID:24142310

Rosa, Rafael Fabiano M.; Rosa, Rosana Cardoso M.; Lorenzen, Marina Boff; Zen, Paulo Ricardo G.; Graziadio, Carla; Paskulin, Giorgio Adriano

2013-01-01

334

Schizophrenogenic Parenting in Abnormal Psychology Textbooks.  

ERIC Educational Resources Information Center

Considers the treatment of family causation of schizophrenia in undergraduate abnormal psychology textbooks. Reviews texts published only after 1986. Points out a number of implications for psychologists which arise from the inclusion in these texts of the idea that parents cause schizophrenia, not the least of which is the potential for…

Wahl, Otto F.

1989-01-01

335

Teaching Abnormal Psychology in a Multimedia Classroom.  

ERIC Educational Resources Information Center

Examines the techniques used in teaching an abnormal psychology class in a multimedia environment with two computers and a variety of audiovisual equipment. Students respond anonymously to various questions via keypads mounted on their desks, then immediately view and discuss summaries of their responses. (MJP)

Brewster, JoAnne

1996-01-01

336

A microcontroller-based system for automated and continuous sky glow measurements with the use of digital single-lens reflex cameras  

NASA Astrophysics Data System (ADS)

In recent years, the scientific community has shown an increased interest in sky glow research. This has revealed an increased need for automated technology that enables continuous evaluation of sky glow. As a result, a reliable low-cost platform has been developed and constructed for automating sky glow measurement. The core of the system is embedded software and hardware managed by a microcontroller with ARM architecture. A monolithic photodiode transimpedance amplifier is used to allow linear light measurement. Data from the diode are collected and used to arrange the exposure time of every image captured by the digital single-lens reflex camera. This proposal supports experimenters by providing a low-cost system to analyse sky glow variations overnight without a human interface.

Solano Lamphar, Hétor Antonio; Kundracik, Frantisek

2014-02-01

337

Microstructural Evolution During Normal/Abnormal Grain Growth in Austenitic Stainless Steel  

NASA Astrophysics Data System (ADS)

The grain growth behavior of 304L stainless steel was studied in a wide range of annealing temperatures and times with emphasis on the distinction between normal and abnormal grain growth (AGG) modes. The dependence of AGG (secondary recrystallization) at homologous temperatures of around 0.7 upon microstructural features such as dispersed carbides, which were rich in Ti but were almost free of V, was investigated by optical micrographs, X-ray diffraction patterns, scanning electron microscopy images, and energy dispersive X-ray analysis spectra. The bimodality in grain-size distribution histograms signified that a transition in grain growth mode from normal to abnormal was occurred at homologous temperatures of around 0.7 due to the dissolution/coarsening of carbides. Continued annealing to a long time led to completion of secondary recrystallization and the subsequent reappearance of normal growth mode. Another noticeable abnormality in grain growth was observed at very high annealing temperatures, which may be related to grain boundary faceting/defaceting. Finally, a versatile grain growth map was proposed, which can be used as a practical guide for estimation of the resulting grain size after exposure to high temperatures.

Shirdel, Mohammad; Mirzadeh, Hamed; Habibi Parsa, Mohammad

2014-10-01

338

Enhancing DC Glow Discharge Tube Museuum Displays using a Theremin Controlled Helmholtz Coil to Demonstrate Magnetic Confinement  

NASA Astrophysics Data System (ADS)

Since their discovery in the mid 1800's, DC glow discharge apparatuses have commonly been used for spectral analysis, the demonstration of the Frank-Hertz experiment, and to study plasma breakdown voltages following from the Paschen Curve. A DC glow discharge tube museum display was outfitted with a Helmholtz Coil electromagnet in order to demonstrate magnetic confinement for a science museum display. A device commonly known as a ``theremin'' was designed and built in order to externally control the Helmholtz Coil current and the plasma current. Originally a musical instrument, a theremin has two variable capacitors connected to two radio frequency oscillators which determine pitch and volume. Using a theremin to control current and ``play'' the plasma adds appeal and durability by providing a new innovative means of interacting with a museum exhibit. Educationally, students can use the display to not only learn about plasma properties but also electronic properties of the human body.

Siu, Theodore; Wissel, Stephanie; Guttadora, Larry; Liao, Susan; Zwicker, Andrew

2010-11-01

339

Study of the glow dynamics in a laser-produced plasma jet expanding across the magnetic field  

SciTech Connect

Results are presented from experimental studies of the glow dynamics of a plasma jet generated during the irradiation of a plane aluminum target by an iodine laser pulse with the wavelength 1.315 {mu}m. The laser pulse energy was 330-480 J, the pulse duration was 0.5 ns, and the focal spot diameter was 3 mm, the laser intensity on the target surface being {approx}10{sup 13} W/cm{sup 2}. The jet expanded across an external magnetic field with the strength {approx}1 kOe. The residual air pressure in the vacuum chamber was {approx}10{sup -5} Torr. The spatiotemporal behavior of the jet glow was investigated using a nine-frame camera in two mutually perpendicular directions (along and across the magnetic field). The results of measurements indicate azimuthal asymmetry of the jet expansion.

Bessarab, A. V.; Bondarenko, G. A.; Garanin, S. G.; Zhidkov, N. V.; Nikitin, I. N.; Starodubtsev, V. A.; Sungatullin, R. R. [All-Russia Research Institute of Experimental Physics, Russian Federal Nuclear Center (Russian Federation)

2011-09-15

340

Investigation of the spatial and temporal distribution of plasma excited species produced in laser ablation-glow discharge  

NASA Astrophysics Data System (ADS)

Laser Ablation and Glow Discharge (LAGD) plasmas have been coupled and optical emission measurements have been performed in order to study the spatial and temporal distribution of LA and GD species and hence to get further insights into the interaction between them. The relative delay between the laser event and the emission measurement along the GD pulse has been found as a crucial parameter. In addition, no post excitation of the ablated material has been observed when laser ablation takes place during GD prepeak or plateau. In contrast, emission enhancements (e.g. Al I lines at ~ 877 nm presented an enhancement of up to 4 times in the LAGD plasma) were obtained during the afterglow or late plateau, when firing the laser at delays close (< 100 ?s) to GD pulse termination. Penning ionization of the ablated material within the GD afterglow, followed by recombination processes, seems to account for the emission enhancements obtained when combining laser ablation and glow discharge.

Valledor, Rebeca; Tarik, Mohamed; Pisonero, Jorge; Bordel, Nerea; Günther, Detlef

2014-10-01

341

The effects of selected Vesicular Arbuscular Mycorrhizae on growth and water relation of geranium (Pelargonium x hortorum 'cherry glow')  

E-print Network

THE EFFECTS OF S~ VESICULAR ARBUSCULAR MYCORRHIZAE OW GROWTH AWD WATER RELATION OF GERAWIUM (P~IUM x HORTORUM 'CHERRY GLOW' ) A Thesis MICHAEL RAYMOND SWEATT Apprcnred as to style and content by: (Chairman of Committee) (Member) (Head o... partment) August 1982 ABSTRACT The Effects of Selected Vesicular Arbuscular Mycorrhizae on Growth and Water Relations 2 G 2 (~*P) 2 h t 'Gh*&Gl ') ldg t)P82) Michael Raymond 'Sweatt, B. S. , West Tezas State University Chairman of Advisory Committeeg...

Sweatt, Michael Raymond

2012-06-07

342

Effect of deposition conditions on the nucleation and growth of glow-discharge aSi:H  

Microsoft Academic Search

Insitu ellipsometry experiments have been used to study the initial nucleation and growth of glow-discharge hydrogenated amorphous silicon (a-Si:H) deposited on c-Si substrates under different conditions. The substrate temperature (Ts), dc bias, and silane concentration in both hydrogen and inert gas diluents were varied. In the first ?30–60 A? of film growth, deviations of the insitu ellipsometry data from models

R. W. Collins; J. M. Cavese

1987-01-01

343

Effects of helium dilution on glow discharge depositions of aSi 1-xGex:H alloys  

Microsoft Academic Search

A study is made of the effects of helium feed gas dilution on the properties of a-Si1-xGex:H alloys deposited using radio-frequency glow discharge decomposition of silane and germane gas mixtures. Comparing a-Si1-xGex:H films deposited using 65% helium dilution with films deposited using 65% hydrogen dilution, it is found that films deposited with helium dilution have a longer charge carrier diffusion

Y. S. Tsuo; Y. Xu; I. Balberg; R. S. Crandall

1991-01-01

344

Inhibition of bacterial adhesion on PVC endotracheal tubes by RF-oxygen glow discharge, sodium hydroxide and silver nitrate treatments  

Microsoft Academic Search

Medical-grade poly(vinyl chloride) (PVC) was chemically modified to study how the incorporation of monovalent silver influences Pseudomonas aeruginosa adhesion and colonization. The modification investigated consisted of a radio frequency-oxygen (RF-O2) glow discharge pre-functionalization, followed by a two-step wet-treatment in sodium hydroxide and silver nitrate solutions. X-ray photoelectron spectroscopy (XPS) analysis and contact angle measurements were used to investigate the chemical

D. J. Balazs; K. Triandafillu; P. Wood; Y. Chevolot; C. van Delden; H. Harms; C. Hollenstein; H. J. Mathieu

2004-01-01

345

Experimental and numerical study of an atmospheric pressure glow discharge in helium  

NASA Astrophysics Data System (ADS)

. Atmospheric pressure glow discharges in helium have been reported to produce radially uniform plasmas and to show one single current pulse per half cycle of the AC high voltage [1]. However, in other studies the appearance of multiple periodic peaks per half cycle has been reported as well. Different interpretations have been given for this effect ranging from the oscillation of the cathode sheath [2] to multiple successive breakdowns [3]. We have performed studies with different dielectrics to investigate their effect on the discharge behavior: two circular 4 cm diameter electrodes have been covered with (1) 1.7 mm thick glass plates (er = 4.6) and with (2) 0.635 mm thick alumina plates (er = 9). At a gap of 5 mm, multiple current peaks were observed with both configurations. Time resolved measurements of the emission intensity using a gated intensified CCD camera were performed, both in axial and radial direction. These indicate that the first current pulse is produced by a radially propagating ionization front, while later peaks are related to breakdowns at the electrode edges. With 0.635 mm thick alumina plates we could observe the appearance of a strong cathode fall in front of the momentary cathode, together with a Faraday dark space and a positive column that extended for a length of 2-3 mm. A two-dimensional fluid model has been realized to study the glow discharge behavior. The numerical result is qualitatively in good agreement with the observed structure of the discharge. The model reproduces the radial propagation of the ionization wave. This work is supported by the Department of Energy under grant DE-FG02-00ER54583. [1] Massines F., Rabehi A., Decomps P., Gadri R.B., Segur P., and Mayoux C., J.Appl.Phys. 83, 2950- 2957 (1998). [2] Akishev Y.S., Dem'yanov A., Karal'nik V.B., Trushkin N.I., and Pan'kin M.V., Proc. Of XXIV ICPIG, Poland, July 11-16, 137-138, (1999). [3] Mangolini L., Orlov K., Kortshagen U., Heberlein J., and Kogelschatz U., Appl.Phys.Lett.80, 1723 (2002).

Mangolini, Lorenzo; Zhang, Peng; Anderson, Curtis; Kortshagen, Uwe; Heberlein, Joachim

2002-10-01

346

Analytic model of the cathode region of a short glow discharge in light gases  

NASA Astrophysics Data System (ADS)

A self-consistent analytic model of the cathode region of a dc glow discharge is suggested. The description is based on the division of the discharge gap into a space-charge sheath and a plasma region and on an approximate kinetic analysis of different groups of electrons. A one-dimensional short discharge is considered for which the positive column is absent and the energy relaxation length ?? of slow untrapped electrons exceeds the gap length L. In this case, a point exists in the negative glow (NG) region where the plasma density has a maximum and the electric field changes sign. Three groups of electrons are treated separately. The first of them includes fast electrons with energies exceeding the first excitation potential ?*. They are emitted by the cathode surface (primaries) or generated in the cathode fall region. These electrons are responsible for ionization and excitation processes and electron-current transport in the sheath and in the immediately adjacent plasma. The field reversal is caused by the nonlocal ionization in the plasma part of the NG, which is determined by the fast electrons. The slow electrons are subdivided into trapped and intermediate ones. The full energy ? (kinetic plus potential) of the trapped electrons is less than the anode potential e?a. These electrons determine the plasma density but give no contribution to the electron current. In the Faraday dark space, the electron current is due to diffusion of the intermediate electrons with energies e?aL does not depend on x. The plasma density profile is obtained from the ambipolar diffusion equation. The kinetic analysis of the trapped electrons is necessary only for the calculation of Te and ?a values. A criterion for the field reversal is proposed. The results are compared with experimental and simulation results of other authors.

Kolobov, V. I.; Tsendin, L. D.

1992-12-01

347

Abnormal Selective Attention in Psychopathic Female Offenders  

PubMed Central

Research on psychopathy in women has generated equivocal laboratory findings. This study examined the performance of psychopathic women in 2 laboratory tasks designed to assess abnormal selective attention associated with response modulation deficits: a computerized picture–word (PW) task, and a picture–word Stroop (PW Stroop) task. Consistent with data from psychopathic men, women receiving high scores on the Psychopathy Checklist—Revised (Hare, 1991) displayed reduced Stroop interference on the PW and PW Stroop tasks. Results suggest that despite some differences in the expression of psychopathy across gender, psychopathic women are characterized by selective attention abnormalities predicted by the response modulation hypothesis and similar to those exhibited by psychopathic men. PMID:17484593

Vitale, Jennifer E.; Brinkley, Chad A.; Hiatt, Kristina D.; Newman, Joseph P.

2011-01-01

348

[Epilepsy in patient with structural autosomal abnormality].  

PubMed

Few cases have been reported on the structural autosomal abnormality (SAA) focusing on epilepsy excluding those of Down syndrome and Klinefelter syndrome. We investigated patients who had SAA with special reference to epilepsy. Various types of epilepsy were observed in its severity in our cases as well as previously reported cases. There was no correlation between the degree of mental retardation, motor dysfunction, brain damage on CT scan, and severity of epilepsy. Some cases had brain dysplasia, such as agenesis of corpus callosum, pachygyria, and mega cisterna magna. No correlation was found between these brain dysplasia and severity of epilepsy. It is important for a pediatrician to find a common epileptic syndrome or EEG abnormality in a SAA. An observation of symptoms in patients with the same chromosomal deletion or duplication will lead to identification of responsible gene for an epileptic symptom. PMID:7803078

Sugama, S; Atsukawa, K; Kusano, K; Akatsuka, A; Ochiai, Y; Tsuzura, S; Maekawa, K

1994-11-01

349

Model Insensitive and Calibration Independent Method for Determination of the Downstream Neutral Hydrogen Density Through Ly-alpha Glow Observations  

NASA Technical Reports Server (NTRS)

Our knowledge of the various heliospheric phenomena (location of the solar wind termination shock, heliopause configuration and very local interstellar medium parameters) is limited by uncertainties in the available heliospheric plasma models and by calibration uncertainties in the observing instruments. There is, thus, a strong motivation to develop model insensitive and calibration independent methods to reduce the uncertainties in the relevant heliospheric parameters. We have developed such a method to constrain the downstream neutral hydrogen density inside the heliospheric tail. In our approach we have taken advantage of the relative insensitivity of the downstream neutral hydrogen density profile to the specific plasma model adopted. We have also used the fact that the presence of an asymmetric neutral hydrogen cavity surrounding the sun, characteristic of all neutral densities models, results in a higher multiple scattering contribution to the observed glow in the downstream region than in the upstream region. This allows us to approximate the actual density profile with one which is spatially uniform for the purpose of calculating the downstream backscattered glow. Using different spatially constant density profiles, radiative transfer calculations are performed, and the radial dependence of the predicted glow is compared with the observed I/R dependence of Pioneer 10 UV data. Such a comparison bounds the large distance heliospheric neutral hydrogen density in the downstream direction to a value between 0.05 and 0.1/cc.

Gangopadhyay, P.; Judge, D. L.

1996-01-01

350

Cortical thickness abnormality in juvenile myoclonic epilepsy  

Microsoft Academic Search

Previous studies on gray matter concentration changes in patients with juvenile myoclonic epilepsy (JME) are inconsistent.\\u000a To investigate cortical abnormality in JME differently, we measured the cortical thickness in 19 JME patients and 18 normal\\u000a controls. Results showed that the cortical thicknesses of superior\\/middle\\/medial frontal gyri, and superior\\/middle\\/ inferior\\u000a temporal gyri were decreased in JME patients. Moreover, cortical thicknesses of

Woo Suk Tae; Sun Hyung Kim; Eun Yun Joo; Sun Jung Han; I. Y. Kim; S. I. Kim; J.-M. Lee; S. B. Hong

2008-01-01

351

Urinary abnormalities in non gonococcal urethritis.  

PubMed Central

The association between urinary abnormalities detected by the two-glass urine test and objective urethritis was investigated in a study of 221 male patients with non-gonococcal urethritis. A strong correlation existed between urinary threads and urethritis, but use of the test for diagnosis and in the assessment of cure is limited by its poor predictive value in both treated and untreated patients. PMID:7326552

Munday, P E; Altman, D G; Taylor-Robinson, D

1981-01-01

352

Sonic Hedgehog Genetic Abnormalities and Tissue Donations  

NSDL National Science Digital Library

In this case study about a baby born with the genetic condition holoprosencephaly, students explore the “Sonic hedgehog” gene, signal transduction, and the ethics of body and tissue donation. The assignment involves students writing an informed consent document that explains the science behind this congenital abnormality. Designed for an upper-level undergraduate biology course, the case could also be used in a cell biology, developmental biology, neurobiology, or other related upper-level course.

Yaich, Lauren E.

2001-01-01

353

CT of trauma to the abnormal kidney  

SciTech Connect

Traumatic injuries to already abnormal kidneys are difficult to assess by excretory urography and clinical evaluation. Bleeding and urinary extravasation may accompany minor trauma; conversely, underlying tumors, perirenal hemorrhage, and extravasation may be missed on urography. Computed tomography (CT) was performed in eight cases including three neoplasms, one adult polycystic disease, one simple renal cyst, two hydronephrotic kidneys, and one horseshoe kidney. CT provided specific and clinically useful information in each case that was not apparent on excretory urography.

Rhyner, P.; Federle, M.P.; Jeffrey, R.B.

1984-04-01

354

Esophageal motility abnormalities in gastroesophageal reflux disease  

PubMed Central

Esophageal motility abnormalities are among the main factors implicated in the pathogenesis of gastroesophageal reflux disease. The recent introduction in clinical and research practice of novel esophageal testing has markedly improved our understanding of the mechanisms contributing to the development of gastroesophageal reflux disease, allowing a better management of patients with this disorder. In this context, the present article intends to provide an overview of the current literature about esophageal motility dysfunctions in patients with gastroesophageal reflux disease. Esophageal manometry, by recording intraluminal pressure, represents the gold standard to diagnose esophageal motility abnormalities. In particular, using novel techniques, such as high resolution manometry with or without concurrent intraluminal impedance monitoring, transient lower esophageal sphincter (LES) relaxations, hypotensive LES, ineffective esophageal peristalsis and bolus transit abnormalities have been better defined and strongly implicated in gastroesophageal reflux disease development. Overall, recent findings suggest that esophageal motility abnormalities are increasingly prevalent with increasing severity of reflux disease, from non-erosive reflux disease to erosive reflux disease and Barrett’s esophagus. Characterizing esophageal dysmotility among different subgroups of patients with reflux disease may represent a fundamental approach to properly diagnose these patients and, thus, to set up the best therapeutic management. Currently, surgery represents the only reliable way to restore the esophagogastric junction integrity and to reduce transient LES relaxations that are considered to be the predominant mechanism by which gastric contents can enter the esophagus. On that ground, more in depth future studies assessing the pathogenetic role of dysmotility in patients with reflux disease are warranted. PMID:24868489

Martinucci, Irene; de Bortoli, Nicola; Giacchino, Maria; Bodini, Giorgia; Marabotto, Elisa; Marchi, Santino; Savarino, Vincenzo; Savarino, Edoardo

2014-01-01

355

Abnormal calcium homeostasis in peripheral neuropathies  

PubMed Central

Abnormal neuronal calcium (Ca2+) homeostasis has been implicated in numerous diseases of the nervous system. The pathogenesis of two increasingly common disorders of the peripheral nervous system, namely neuropathic pain and diabetic polyneuropathy, has been associated with aberrant Ca2+ channel expression and function. Here we review the current state of knowledge regarding the role of Ca2+ dyshomeostasis and associated mitochondrial dysfunction in painful and diabetic neuropathies. The central impact of both alterations of Ca2+ signalling at the plasma membrane and also intracellular Ca2+ handling on sensory neuron function is discussed and related to abnormal endoplasmic reticulum performance. We also present new data highlighting sub-optimal axonal Ca 2+ signalling in diabetic neuropathy and discuss the putative role for this abnormality in the induction of axonal degeneration in peripheral neuropathies. The accumulating evidence implicating Ca2+ dysregulation with both painful and degenerative neuropathies, along with recent advances in understanding of regional variations in Ca2+ channel and pump structures, makes modulation of neuronal Ca2+ handling an increasingly viable approach for therapeutic interventions against the painful and degenerative aspects of many peripheral neuropathies. PMID:20034667

Fernyhough, Paul; Calcutt, Nigel A.

2010-01-01

356

Reversible abnormalities of myocardial relaxation in hypothyroidism.  

PubMed

Fifteen selected hypothyroid patients without symptoms or signs of cardiovascular disease and an equal number of matched control subjects underwent simultaneous recording of electrocardiogram and phono-, apex-, and echocardiography to assess dynamic systolic and diastolic left ventricular function. Both the systolic preejection period and the isovolumic relaxation period were significantly increased in the hypothyroid group. However, whereas the rate of myocardial contraction, assessed from the echocardiograph of the left ventricular posterior wall, was identical in patients and control subjects, the diastolic thinning rate of the muscle was markedly slowed in the hypothyroid individuals. The abnormalities demonstrated were in the main completely reversed after 3 months of T4 therapy. These results demonstrate a relatively selective and readily reversible disturbance of the rate of myocardial relaxation in hypothyroidism, suggesting an intrinsic abnormality of cardiac muscle. This allows an intriguing parallel to be drawn with the delayed relaxation phase of voluntary muscle contraction, long recognized as a direct measure of tissue thyroid function in hypothyroidism. The abnormality of diastolic function we have described is of similar character to that found in patients with other cardiomyopathies and which has been shown to be a major cause of disturbance of global cardiac action. PMID:4008607

Vora, J; O'Malley, B P; Petersen, S; McCullough, A; Rosenthal, F D; Barnett, D B

1985-08-01

357

Alcohol and abnormal outcomes of pregnancy.  

PubMed Central

Heavy alcohol consumption by the mother during pregnancy has long been suspected of being a risk factor for abnormalities in the fetus or infant. Only during the last decade have these assumptions been supported by scientific studies. A clustering of fetal defects observed in some cases has been labelled the fetal alcohol syndrome. The syndrome involves prenatal and postnatal growth retardation, central nervous system involvement and craniofacial abnormalities, some of which are characteristic of the syndrome. Fetal alcohol syndrome is relatively rare, affecting from 1 in 300 to 1 in 2000 infants; approximately 450 cases have been reported since the syndrome was identified. Despite this rarity, however, heavy alcohol consumption is an important risk factor during pregnancy. A review of the current literature indicates that in animals alcohol in high doses is embryotoxic and teratogenic, the heavy drinking is not uncommon before and during pregnancy and that the fetal alcohol syndrome and other effects on the fetus associated with alcohol abuse appear with significant frequency among mothers who drink heavily. Heavy alcohol consumption is a perinatal risk factor that not only can be detected by the physician, but also can be reduced in concerned, cooperative patients. Thus, awareness of this problem gives health care personnel an opportunity to help in the prevention of abnormal outcomes of pregnancy. Images FIG. 1 PMID:7023637

Sokol, R. J.

1981-01-01

358

Neurological abnormalities in young adults born preterm  

PubMed Central

Objective Individuals born before 33?weeks' gestation (very preterm, VPT) have an increased likelihood of neurological abnormality, impaired cognitive function, and reduced academic performance in childhood. It is currently not known whether neurological signs detected in VPT children persist into adulthood or become attenuated by maturation of the CNS. Method We assessed 153 VPT individuals and 71 term?born controls at 17–18?years old, using a comprehensive neurological examination. This examination divides neurological signs into primary and integrative domains, the former representing the localising signs of classical neurology, and the latter representing signs requiring integration between different neural networks or systems. Integrative signs are sub?divided into three groups: sensory integration, motor confusion, and sequencing. The VPT individuals have been followed up since birth, and neonatal information is available on them, along with the results of neurological assessment at 4 and 8?years of age and neuropsychological assessment at 18?years of age. Results The total neurology score and primary and integrative scores were significantly increased in VPT young adults compared to term?born controls. Within the integrative domain, sensory integration and motor confusion scores were significantly increased in the VPT group, but sequencing was not significantly different between the VPT and term groups. Integrative neurological abnormalities at 18 were strongly associated with reduced IQ but primary abnormalities were not. Conclusions Neurological signs are increased in VPT adults compared to term?born controls, and are strongly associated with reduced neuropsychological function. PMID:16543529

Allin, M; Rooney, M; Griffiths, T; Cuddy, M; Wyatt, J; Rifkin, L; Murray, R

2006-01-01

359

Trading networks, abnormal motifs and stock manipulation  

E-print Network

We study trade-based manipulation of stock prices from the perspective of complex trading networks constructed by using detailed information of trades. A stock trading network consists of nodes and directed links, where every trader is a node and a link is formed from one trader to the other if the former sells shares to the latter. Specifically, three abnormal network motifs are investigated, which are found to be formed by a few traders, implying potential intention of price manipulation. We further investigate the dynamics of volatility, trading volume, average trade size and turnover around the transactions associated with the abnormal motifs for large, medium and small trades. It is found that these variables peak at the abnormal events and exhibit a power-law accumulation in the pre-event time period and a power-law relaxation in the post-event period. We also find that the cumulative excess returns are significantly positive after buyer-initiated suspicious trades and exhibit a mild price reversal afte...

Jiang, Zhi-Qiang; Xiong, Xiong; Zhang, Wei; Zhang, Yong-Jie; Zhou, W -X

2013-01-01

360

Abnormal dynamics of language in schizophrenia.  

PubMed

Language could be conceptualized as a dynamic system that includes multiple interactive levels (sub-lexical, lexical, sentence, and discourse) and components (phonology, semantics, and syntax). In schizophrenia, abnormalities are observed at all language elements (levels and components) but the dynamic between these elements remains unclear. We hypothesize that the dynamics between language elements in schizophrenia is abnormal and explore how this dynamic is altered. We, first, investigated language elements with comparable procedures in patients and healthy controls. Second, using measures of reaction time, we performed multiple linear regression analyses to evaluate the inter-relationships among language elements and the effect of group on these relationships. Patients significantly differed from controls with respect to sub-lexical/lexical, lexical/sentence, and sentence/discourse regression coefficients. The intercepts of the regression slopes increased in the same order above (from lower to higher levels) in patients but not in controls. Regression coefficients between syntax and both sentence level and discourse level semantics did not differentiate patients from controls. This study indicates that the dynamics between language elements is abnormal in schizophrenia. In patients, top-down flow of linguistic information might be reduced, and the relationship between phonology and semantics but not between syntax and semantics appears to be altered. PMID:24629711

Stephane, Massoud; Kuskowski, Michael; Gundel, Jeanette

2014-05-30

361

Chromosomal Abnormality in Men with Impaired Spermatogenesis  

PubMed Central

Background: Chromosomal abnormalities and Y chromosome microdeletions are regarded as two most frequent genetic causes associated with failure of spermatogenesis in the Caucasian population. Materials and Methods: To investigate the distribution of genetic defects in the Romanian population with azoospermia or severe oligozoospermia, karyotype analysis by G-banding was carried out in 850 idiopathic infertile men and in 49 fertile men with one or more children. Screening for microdeletions in the azoospermia factor (AZF) region of Y chromosome was performed by multiplex polymerase chain reaction (PCR) on a group of 67 patients with no detectable chromosomal abnormality. The results of the two groups were compared by a two-tailed Fisher’s exact test. Results: In our study chromosomal abnormalities were observed in 12.70% and 8.16% of infertile and fertile individuals respectively. Conclusion: Our data suggests that infertile men with severe azoospermia have higher incidences of genetic defects than fertile men and also patients from any other group. Infertile men with normal sperm present a higher rate of polymorphic variants. It is important to know whether there is a genetic cause of male infertility before patients are subjected to intracytoplasmic sperm injection (ICSI) or testicular sperm extraction (TESE)/ICSI treatment. PMID:24696767

Mierla, Dana; Jardan, Dumitru; Stoian, Veronica

2014-01-01

362

Sensory abnormalities in autism. A brief report.  

PubMed

Sensory abnormalities were assessed in a population-based group of 208 20-54-month-old children, diagnosed with autism spectrum disorder (ASD) and referred to a specialized habilitation centre for early intervention. The children were subgrouped based upon degree of autistic symptoms and cognitive level by a research team at the centre. Parents were interviewed systematically about any abnormal sensory reactions in the child. In the whole group, pain and hearing were the most commonly affected modalities. Children in the most typical autism subgroup (nuclear autism with no learning disability) had the highest number of affected modalities. The children who were classified in an "autistic features" subgroup had the lowest number of affected modalities. There were no group differences in number of affected sensory modalities between groups of different cognitive levels or level of expressive speech. The findings provide support for the notion that sensory abnormality is very common in young children with autism. This symptom has been proposed for inclusion among the diagnostic criteria for ASD in the upcoming DSM-V. PMID:21111574

Klintwall, Lars; Holm, Anette; Eriksson, Mats; Carlsson, Lotta Höglund; Olsson, Martina Barnevik; Hedvall, Asa; Gillberg, Christopher; Fernell, Elisabeth

2011-01-01

363

List mode multichannel analyzer  

DOEpatents

A digital list mode multichannel analyzer (MCA) built around a programmable FPGA device for onboard data analysis and on-the-fly modification of system detection/operating parameters, and capable of collecting and processing data in very small time bins (<1 millisecond) when used in histogramming mode, or in list mode as a list mode MCA.

Archer, Daniel E. (Livermore, CA); Luke, S. John (Pleasanton, CA); Mauger, G. Joseph (Livermore, CA); Riot, Vincent J. (Berkeley, CA); Knapp, David A. (Livermore, CA)

2007-08-07

364

Fast Mode Decision Based on Mode Adaptation  

Microsoft Academic Search

This paper proposes an efficient algorithm for fast mode decision in H.264\\/advanced video coding by adaptively predicting the optimal mode for each macroblock (MB) to be coded. Firstly, encoding modes are projected as points onto a 2-D map, and an optimal 2-D point of the MB to be coded is predicted based on the encoding information of spatial-temporal neighboring blocks.

Tiesong Tiesong Zhao; Hanli Wang; Sam Kwong; C.-C. Jay Kuo

2010-01-01

365

Patients with chronic pain and abnormal pituitary function require investigation.  

PubMed

Misuse of opioids is associated with abnormalities of pituitary function. Patients with chronic pain frequently complain of fatigue and undergo endocrine testing. To test whether oral opioid treatment causes abnormal pituitary function we prospectively assessed pituitary function in 37 patients with chronic pain who were receiving either oral opioid analgesia or non-opioid analgesia. Oral opioid treatment was not associated with abnormal pituitary function although a few patients had abnormal results mainly related to obesity. Our results suggest that patients with chronic pain who have abnormal endocrine results should have a complete assessment, since abnormal test results cannot be attributed to their analgesia. PMID:12842375

Merza, Z; Edwards, N; Walters, S J; Newell-Price, J; Ross, R J M

2003-06-28

366

Optomechanical Dark Mode  

NASA Astrophysics Data System (ADS)

Thermal mechanical motion hinders the use of a mechanical system in applications such as quantum information processing. Whereas the thermal motion can be overcome by cooling a mechanical oscillator to its motional ground state, an alternative approach is to exploit the use of a mechanically dark mode that can protect the system from mechanical dissipation. We have realized such a dark mode by coupling two optical modes in a silica resonator to one of its mechanical breathing modes in the regime of weak optomechanical coupling. The dark mode, which is a superposition of the two optical modes and is decoupled from the mechanical oscillator, can still mediate an effective optomechanical coupling between the two optical modes. We show that the formation of the dark mode enables the transfer of optical fields between the two optical modes. Optomechanical dark mode opens the possibility of using mechanically mediated coupling in quantum applications without cooling the mechanical oscillator to its motional ground state.

Dong, Chunhua; Fiore, Victor; Kuzyk, Mark C.; Wang, Hailin

2012-12-01

367

Pulsed laser ablation of borax target in vacuum and hydrogen DC glow discharges  

NASA Astrophysics Data System (ADS)

The aim of our experiment was to produce a material with B sbnd H bonds for applications in hydrogen storage and generation. By using KrF excimer laser ( ? = 248 nm) ablation of borax (Na 2B 4O 7) target, thin films were deposited on KBr and silicon substrates. Ablation was performed both in vacuum and in hydrogen atmosphere. DC glow discharge technique was utilized to enhance hydrogen gas ionization. Experiments were performed using laser fluence from 5 to 20 J/cm 2. Films were deposited under gas pressure of 1 × 10 -5 to 5 × 10 -2 mbar and substrate temperatures of 130-450 °C. Scanning electron microscopy analysis of films showed presence of circular particulates. Film thickness, roughness and particulates number increased with increase in laser fluence. Energy dispersive X-ray spectroscopy analysis shows that sodium content in the particulates is higher than in the target. This effect is discussed in terms of atomic arrangements (both at surface and bulk) in systems where ionic and covalent bonds are present and by looking at the increased surface/bulk ratio of the particulates with respect to the deposited films. The Fourier transform infrared spectroscopy measurements showed presence of B sbnd O stretching and B sbnd O sbnd B bending bonds. Possible reasons for absence of B sbnd H bonds are attributed to binding enthalpy of the competing molecules.

Kale, A. N.; Miotello, A.; Mosaner, P.

2006-09-01

368

Ab initio based calculation of emission properties of Ar-AlCl3 glow discharge  

NASA Astrophysics Data System (ADS)

Emission properties of Ar-AlCl3 DC glow discharge were calculated using ``Chemical Workbench'' VIBRAKIN code in frame work of quasi 1D model. Unknown properties of atoms and molecules were calculated from first principles. Potential energy curves of AlxCly^- negative ions were performed by approximate quadratic coupled cluster (AQCC) and SCF methods. Potential energy curves, transition dipole moments of neutral species AlxCly were calculated based on many-body multipartitioning perturbation theory (MPPT). These data are used for evaluation of the cross sections of the electron impact dissociative attachment and vibrational excitation for AlCl3 and fragments of its decomposition. The cross sections of the electron impact excitation of electronic states of atoms and molecules are evaluated in frame work modified Born approximation with taking into account electron exchange. Based on calculated properties of molecular ions, the rate parameters of thermal ion-molecular reactions of molecular ions conversion were calculated. The calculation results present dependencies of the electron energy balance and the emission efficiency as a function of the plasma parameters.

Deminsky, Maxim; Potapkin, Boris; Umanskii, Stanislav; Zaitsevskii, Alexander; Smith, David; Michael, Darryl; Sommerer, Timothy

2009-10-01

369

Modification of surface properties of polypropylene (PP) film using DC glow discharge air plasma  

NASA Astrophysics Data System (ADS)

The industrial use of polypropylene (PP) films is limited because of undesirable properties such as poor adhesion and printability. In the present study, a DC glow discharge plasma has been used to improve the surface properties of PP films and make it useful for technical applications. The change in hydrophilicity of modified PP film surface was investigated by contact angle (CA) and surface energy measurements as a function of exposure time. In addition, plasma-treated PP films have been subjected to an ageing process to determine the durability of the plasma treatment. Changes in morphological and chemical composition of PP films were analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The improvement in adhesion was studied by measuring T-peel and lap shear strength. The results show that the surface hydrophilicity has been improved due to the increase in the roughness and the introduction of oxygen-containing polar groups. The AFM observation on PP film shows that the roughness of the surface increased due to plasma treatment. Analysis of chemical binding states and surface chemical composition by XPS showed an increase in the formation of polar functional groups and the concentration of oxygen content on the plasma-processed PP film surfaces. T-peel and lap shear test for adhesion strength measurement showed that the adhesion strength of the plasma-modified PP films increased compared with untreated films surface.

Pandiyaraj, K. Navaneetha; Selvarajan, V.; Deshmukh, R. R.; Gao, Changyou

370

Destruction of 4-phenolsulfonic acid in water by anodic contact glow discharge electrolysis.  

PubMed

Destruction of 4-phenolsulfonic acid (4-PSA) in water was carried out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon (TOC) in water correspondingly decreased, while the sulfonate group of 4-PSA was released as sulfate ion. Oxalate and formate were obtained as minor by-products. Additionally, phenol, 1,4-hydroquinone, hydroxyquinol and 1,4-benzoquinone were detected as primary intermediates in the initial stages of decomposition of 4-PSA. A reaction pathway involving successive attacks of hydroxyl and hydrogen radicals was assumed on the basis of the observed products and kinetics. It was revealed that the decay of both 4-PSA and TOC obeyed a first-order rate law. The effects of different Fe ions and initial concentrations of 4-PSA on the degradation rate were investigated. It was found that the presence of Fe ions could increase the degradation rate of 4-PSA, while initial concentrations lower than 80 mmol/L had no significant effect on kinetic behaviour. The disappearance rate of 4-PSA was significantly affected by pH. PMID:24191593

Yang, Haiming; An, Baigang; Wang, Shaoyan; Li, Lixiang; Jin, Wenjie; Li, Lihua

2013-06-01

371

Electrical double layers at shock fronts in glow discharges and afterglows  

SciTech Connect

This paper examines the propagation of spark-generated shockwaves (1.0glow discharges and their afterglow. Diagnostic methods were employed and expanded in order to capture the dynamics of the shock front in these weakly-ionized, nonmagnetized, collisional plasmas. We used a microwave hairpin resonator to measure the electron number density, and, for all cases, we measured an increase in the electron number density at the shock front. By comparing the increase in electron number density at the shock front in the active discharge and in the afterglow, we conclude that electrons with a temperature much greater than room temperature can be compressed at the shock front. The ratio of electron number density before and after the shock front can be approximately predicted using the Rankine-Hugoniot relationship. The large gradient in electron density, and hence a large gradient in the flux of charged species, created a region of space-charge separation, i.e., a double layer, at the shock front. The double layer balances the flux of charged particles on both sides of the shock front. The double layer voltage drop was measured in the current-carrying discharge using floating probes and compared with previous models. As well, we measured argon 1s{sup 5} metastable-state density and demonstrate that metastable-state neutral species can be compressed across a shock front and approximately predicted using the Rankine-Hugoniot relationship.

Siefert, Nicholas S. [Air Force Research Laboratory, Wright Patterson, Ohio 45433 (United States)

2010-12-15

372

Co-deposition of Ir-containing Zr coating by double glow plasma  

NASA Astrophysics Data System (ADS)

Ir-Zr co-deposition coatings with 71 at% Zr were deposited on graphite by double glow plasma at 1073-1123 K. The structure and composition of the coatings were confirmed by FE-SEM, XRD, XPS and EDS. The hardness and the elastic modulus of the coatings were estimated by nanoindentation instrument. The adhesion strength between the coating and the substrate was evaluated by a scratch tester. The results showed that the coating was composed of nanocrystalline grains with a size of 80-90 nm compared with 0.5 ?m for the pure Ir coating. The fine grains of the coatings might be attributed to the additional Zr element. New phases IrZr and ZrC were formed due to the high content of Zr and high deposition temperature. The hardness and elastic modulus of the coatings were about 7.5 GPa and 388 GPa, respectively. The adhesive force between the coating and the substrate was about 10 N.

Cong, Xiangna; Chen, Zhaofeng; Wu, Wangping; Chen, Zhou; Edmond Boafo, Fred

2012-10-01

373

SWIR sky-glow cloud correlation with NIR and visible clouds: an urban and rural comparison  

NASA Astrophysics Data System (ADS)

Between the wavelengths of the visible and the Short Wave Infrared (SWIR), the glow of the sky from chemical radiance and absorption changes dramatically. Thus too, the structure and appearance of clouds change. By directly and simultaneously examining clouds in an urban and a rural setting, we investigate the correlation between the appearance of clouds present in the SWIR, NIR, and visible. The experimental setup consists of two sensors, one a NIR to SWIR sensitive InGaAs array, and the other a visible CCD, both co-located on an AZ-EL mount, and both co-boresighted so that different viewing angles of the sky are possible. The SWIR sensor is sensitive from 0.9 ?m to 1.7 ?m. The CCD sensor collects cloud images in the visible region. By making corrections for focal length and pixel size, the visible and SWIR data can be compared. After taking several nights of data in the urban environment of Albuquerque, NM, the entire system was then re-located to a rural location in southern New Mexico.

Dayton, David C.; Gonglewski, John D.; St. Arnauld, Chad; Mons, Ishon; Burns, Dennis

2009-09-01

374

Terahertz Measurements of the Hot Hydronium Ion with an Extended Negative Glow Discharge  

NASA Astrophysics Data System (ADS)

Terahertz absorption spectroscopy was employed to detect the ground-state inversion transitions of the hydronium ion (H3O+). The highly excited ions were created with an extended negative glow discharge through a gas mixture of 1 mtorr of H2O, 2 mtorr of H2, and 12 mtorr of Ar, which allowed observation of transitions with J and K up to 12. In total, 47 transitions were measured in the 0.9-2.0 THz region and 22 of these were observed for the first time. The experimental uncertainties range from 100 to 300 kHz, which are much better than the range 0.3-1.2 MHz reported in previous work. Differences of up to 25.6 MHz were found between the observed positions and the catalog values that have been used for Herschel data analysis of observations of Sagittarius B2(N), NGC 4418, and Arp 220. The new and improved measurements were fit to experimental accuracies with an updated Hamiltonian, and better H3O+ predictions are reported to support the proper analysis of astronomical observations by high-resolution spectroscopy telescopes, such as Herschel, SOFIA, and ALMA.

Yu, Shanshan; Pearson, John C.

2014-05-01

375

Plasma immersion ion implantation using a glow discharge source with controlled plasma potential  

NASA Astrophysics Data System (ADS)

A DC glow discharge plasma source was used in a plasma immersion ion implantation (PIII) experiment providing nitrogen plasmas with densities of 1-3 ×10 10 cm-3 and temperatures of 5-10 eV. Nitrogen ions were extracted from these plasmas and implanted in a variety of immersed samples (Al 5040, SS 304, Si) using repetitive high voltage pulses from two types of sources: PFN pulser and a hard tube pulser. Due to the high potential present in our plasma (350 V), a significant sputter etching of the samples surface occurred at long irradiation times. An electron shower source was used to lower this potential allowing its control from 0 to 350 V. Operating the plasma source at potentials below 70 V reduced the sputtering to negligible levels and a retained dose of 1.5×10 17 cm-2 was achieved in a silicon surface, after irradiation of 1500 min. For plasma with potential of 350 V (no electron shower), the retained doses in Al 5040 and SS 304 samples were smaller than 5×10 16 cm-2, for same plasma and pulser conditions (but 2500 min irradiation), confirming the deleterious effects of sputtering measured in Si samples. Upon using the higher repetition rate pulser, the treatment time was reduced by a factor of 700, thus easing considerably the sputtering problem.

Ueda, M.; Gomes, G. F.; Berni, L. A.; Rossi, J. O.; Barroso, J. J.; Beloto, A. F.; Abramof, E.; Reuther, H.

2000-03-01

376

Modeling characteristics of nonequilibrium processes during breakdown of capacitive rf argon glow discharge  

SciTech Connect

A self-consistent, diffusion-drift approximated fluid model including ion and electron continuity equations and an electron energy equation is presented for simulating the nonequilibrium characteristics during breakdown of argon rf glow discharge. The nonlinear partial differential equations of the model are solved numerically by using a so-called finite volume method. The numerical results indicate that there exist two different phases on the breakdown curves, i.e., the low p{center_dot}d phase and high p{center_dot}d phase. The breakdown voltage, analyzed for three different gaps, varies little in low p{center_dot}d phase while in the high p{center_dot}d phase, it increases linearly with pressure increase. Time evolution of Ohmic heating and energy loss during breakdown are presented in detail. Analysis yields that the heating mechanisms are the dominant factors in breakdown. Moreover, the steady discharge characteristics are also studied specifically under breakdown voltage of 10 Torr. The charged particle densities are on the order of 10{sup 15}/m{sup 3} and the electron energy has two characteristic values at different rf phases.

Deng Yongfeng [State Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, School of Physics and Optoelectronic Technology, and College of Advanced Science and Technology, Dalian University of Technology, Dalian 116085 (China); OXi'an Space Power Institute, Xi'an 710100 (China); Han Xianwei [OXi'an Space Power Institute, Xi'an 710100 (China); Shafiq-ur-Rehman; Liu Yue [State Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, School of Physics and Optoelectronic Technology, and College of Advanced Science and Technology, Dalian University of Technology, Dalian 116085 (China)

2008-05-15

377

The use of matrix-specific calibrations for oxygen in analytical glow discharge spectrometry.  

PubMed

The performance of glow discharge optical emission spectroscopy and mass spectrometry for oxygen determination is investigated using a set of new conductive samples containing oxygen in the percent range in three different matrices (Al, Mg, and Cu) prepared by a sintering process. The sputtering rate corrected calibrations obtained at standard conditions for the 4 mm anode (700 V, 20 mA) in GD-OES are matrix independent for Mg and Al but not for Cu. The importance of a "blue shifted" line of oxygen at 130.22 nm (first reported by Köster) for quantitative analyses by GD-OES is confirmed. Matrix-specific calibrations for oxygen in GD-MS are presented. Two source concepts-fast flow (ELEMENT GD) and low gas flow (VG9000)-are evaluated obtaining higher sensitivity with the static flow source. Additional experiments using Ar-He mixtures or ?s pulsed GD are carried out in ELEMENT GD aiming to improve the oxygen sensitivity. PMID:25335819

Gonzalez-Gago, Cristina; Smid, Petr; Hofmann, Thomas; Venzago, Cornel; Hoffmann, Volker; Gruner, Wolfgang

2014-11-01

378

Non-local effects in a stratified glow discharge with dust particles  

NASA Astrophysics Data System (ADS)

The work is aimed at describing non-local effects in the positive column of a low-pressure stratified dc glow discharge in argon with dust particles in a vertical cylindrical discharge tube. Numerical calculations of plasma parameters in the axis of the discharge tube were performed with the help of a hybrid model based on the solution of a non-local Boltzmann equation for electron energy distribution function (EEDF). Axial distributions of optical emission from striations with dust particles were measured experimentally. Negatively charged dust particles in a low-pressure stratified gas discharge should levitate at the anode-side branch of an electric field distribution above its maximum. At the same time the experiments showed that the dust particles levitate at the cathode side of a stratum. This paradox is explained by the fact that in a low-pressure striated discharge the optical emission distribution is displaced relative to the electric field distribution that was shown both by numerical simulations and experimental measurements.

Sukhinin, G. I.; Fedoseev, A. V.; Ramazanov, T. S.; Amangaliyeva, R. Zh; Dosbalayev, M. K.; Jumabekov, A. N.

2008-12-01

379

Rf-powered glow discharges. Elemental analysis across the solids spectrum  

SciTech Connect

One of the newest and most exciting areas of glow discharge (GD) development is the coupling of radio frequency (rf)-powered GD sources with various analytical spectrometries. In this arrangement, analyses are not limited to conductive samples. Electrical insulators such as glasses, ceramics, and geological materials - some of the most difficult samples to dissolve for solution-based methods of elemental analysis - can readily be examined. The primary, distinct advantage of rf-GD over traditional spectrochemical sources is its inherent capability for the direct solids analysis of both conductive and nonconductive samples. In this report, we review the operational principles as well as the latest developments in rf-GD techniques. Because much of the initial work in the area has focused on the fundamental exploration and instrumental development of these techniques, we have chosen to focus on applications and to present some of the most recent results obtained on commercial instrumentation for both atomic emission spectrometry (AES) and MS. 41 refs., 7 figs., 1 tab.

Marcus, R.K.; Harville, T.R.; Mei, Y.; Shick, C.R. Jr. (Clemson Univ., SC (United States))

1994-09-15

380

Isotope dilution mass spectrometry for quantitative elemental analysis of powdered samples by radiofrequency pulsed glow discharge time of flight mass spectrometry.  

PubMed

In recent years particular effort is being devoted to the development of pulsed glow discharges (PGDs) for mass spectrometry because this powering operation mode could offer important ionization analytical advantages. However, the capabilities of radiofrequency (RF) PGD coupled to a time of flight mass spectrometry (ToFMS) for accurate isotope ratio measurements have not been demonstrated yet. This work is focused on investigating different time positions along the pulse profile for the accurate measurement of isotope ratios. As a result, a method has been developed for the direct and simultaneous multielement determination of trace elements in powdered geological samples by RF-PGD-ToFMS in combination with isotope dilution mass spectrometry (IDMS) as an absolute measurement method directly traceable to the International System of Units. Optimized operating conditions were 70 W of applied radiofrequency power, 250 Pa of pressure, 2 ms of pulse width and 4 ms of pulse period, being argon the plasma gas used. To homogeneously distribute the added isotopically-enriched standards, lithium borate fusion of powdered solid samples was used as sample preparation approach. In this way, Cu, Zn, Ba and Pb were successfully determined by RF-PGD-ToF(IDMS) in two NIST Standard Reference Materials (SRM 2586 and SRM 2780) representing two different matrices of geological interest (soil and rock samples). Cu, Zn, Ba and Pb concentrations determined by RF-PGD-ToF(IDMS) were well in agreement with the certified values at 95% confidence interval and precisions below 12% relative standard deviation were observed for three independent analyses. Elemental concentrations investigated were in the range of 81-5770 mg/kg, demonstrating the potential of RF-PGD-ToF(IDMS) for a sensitive, accurate and robust analysis of powdered samples. PMID:24054645

Alvarez-Toral, Aitor; Fernandez, Beatriz; Malherbe, Julien; Claverie, Fanny; Molloy, John L; Pereiro, Rosario; Sanz-Medel, Alfredo

2013-10-15

381

Genetics Home Reference: X-linked lissencephaly with abnormal genitalia  

MedlinePLUS

... PubMed Recent literature OMIM Genetic disorder catalog Conditions > X-linked lissencephaly with abnormal genitalia On this page: ... names Glossary definitions Reviewed August 2013 What is X-linked lissencephaly with abnormal genitalia? X-linked lissencephaly ...

382

Down's Syndrome and Leukemia: Mechanism of Additional Chromosomal Abnormalities  

ERIC Educational Resources Information Center

Chromosomal abnormalities, some appearing in a stepwise clonal evoluation, were found in five Down's syndrome patients (35 weeks to 12 years old), four with acute leukemia and one with abnormal regulation of leukopoiesis. (Author/SBH)

And Others; Goh, Kong-oo

1978-01-01

383

Structural Pituitary Abnormalities Associated With CHARGE Syndrome  

PubMed Central

Introduction: CHARGE syndrome is a multisystem disorder that, in addition to Kallmann syndrome/isolated hypogonadotrophic hypogonadism, has been associated with anterior pituitary hypoplasia (APH). However, structural abnormalities such as an ectopic posterior pituitary (EPP) have not yet been described in such patients. Objective: The aims of the study were: 1) to describe the association between CHARGE syndrome and a structurally abnormal pituitary gland; and 2) to investigate whether CHD7 variants, which are identified in 65% of CHARGE patients, are common in septo-optic dysplasia /hypopituitarism. Methods: We describe 2 patients with features of CHARGE and EPP. CHD7 was sequenced in these and other patients with septo-optic dysplasia/hypopituitarism. Results: EPP, APH, and GH, TSH, and probable LH/FSH deficiency were present in 1 patient, and EPP and APH with GH, TSH, LH/FSH, and ACTH deficiency were present in another patient, both of whom had features of CHARGE syndrome. Both had variations in CHD7 that were novel and undetected in control cohorts or in the international database of CHARGE patients, but were also present in their unaffected mothers. No CHD7 variants were detected in the patients with septo-optic dysplasia/hypopituitarism without additional CHARGE features. Conclusion: We report a novel association between CHARGE syndrome and structural abnormalities of the pituitary gland in 2 patients with variations in CHD7 that are of unknown significance. However, CHD7 mutations are an uncommon cause of septo-optic dysplasia or hypopituitarism. Our data suggest the need for evaluation of pituitary function/anatomy in patients with CHARGE syndrome. PMID:23526466

Gregory, Louise C.; Gevers, Evelien F.; Baker, Joanne; Kasia, Tessa; Chong, Kling; Josifova, Dragana J.; Caimari, Maria; Bilan, Frederic; McCabe, Mark J.

2013-01-01

384

Chromosome abnormalities in primary ovarian cancer  

SciTech Connect

Chromosome abnormalities that are specific and recurrent may occur in regions of the genome that are involved in the conversion of normal cells to those with tumorigenic potential. Ovarian cancer is the primary cause of death among patients with gynecological malignancies. We have performed cytogenetic analysis of 16 ovarian tumors from women age 28-82. Three tumors of low malignant potential and three granulosa cell tumors had normal karyotypes. To look for the presence of trisomy 12, which has been suggested to be a common aberration in this group of tumors, interphase fluorescence in situ hybridization was performed on direct preparations from three of these tumors using a probe for alpha satellite sequences of chromosome 12. In the 3 preparations, 92-98 percent of the cells contained two copies of chromosome 12, indicating that trisomy 12 is not a universal finding in low grade ovarian tumors. Endometrioid carcinoma of the ovary is histologically indistinguishable from endometial carcinoma of the uterus. We studied 10 endometrioid tumors to determine the degree of genetic similarity between these two carcinomas. Six out of ten endometrioid tumors showed a near-triploid modal number, and one presented with a tetraploid modal number. Eight of the ten contained structural chromosome abnormalities, of which the most frequent were 1p- (5 tumors), 19q+ (3 tumors), 6q- or ins(6) (4 tumors), 3q- or 3q+ (4 tumors). These cytogenetic results resemble those reported for papillary ovarian tumors and differ from those of endometrial carcinoma of the uterus. We conclude that despite the histologic similarities between the endometrioid and endometrial carcinomas, the genetic abnormalities in the genesis of these tumors differ significantly.

Yonescu, R.; Currie, J.; Griffin, C.A. [John Hopkins Univ., Baltimore, MD (United States)

1994-09-01

385

Radiological abnormalities in electric-arc welders.  

PubMed Central

Chest radiographs of 661 British electric-arc welders have been examined by three film readers experienced in the radiology of pneumoconiosis. About 7% of the welders showed signs of small rounded opacities of category 0/1 or greater. No definite evidence of large opacities (Progressive Massive Fibrosis) was seen. The prevalence of chest abnormalities other than pneumoconiosis was 7%. A clear association between prevalence of small rounded opacities of category 0/1 or greater and years of exposure to fumes was established, although few signs of severe grades of simple pneumoconiosis were seen. PMID:656335

Attfield, M D; Ross, D S

1978-01-01

386

The Challenge of Emergency and Abnormal Situations for  

E-print Network

/Abnormal Situation · Prevent Accident/Incident ­ Communicate needed information to flight deck ­ Fight fires · ReduceThe Challenge of Emergency and Abnormal Situations for Flight Attendants The Challenge of Emergency and Abnormal Situations for Flight Attendants By Nora C. Marshall Chief, Survival Factors Division NTSB #12

387

Detecting ECG Abnormalities via Transductive Transfer Department of Computer  

E-print Network

Detecting ECG Abnormalities via Transductive Transfer Learning Kang Li Department of Computer@buffalo.edu ABSTRACT Detecting Electrocardiogram (ECG) abnormalities is the pro- cess of identifying irregular cardiac-physic systems and health infor- matics, embedding the function of ECG abnormality detec- tion to various devices

Buffalo, State University of New York

388

Clinical Significance of Abnormal Electrocardiographic Patterns in Trained Athletes  

Microsoft Academic Search

Background—The prevalence, clinical significance, and determinants of abnormal ECG patterns in trained athletes remain largely unresolved. Methods and Results—We compared ECG patterns with cardiac morphology (as assessed by echocardiography) in 1005 consecutive athletes (aged 2466 years; 75% male) who were participating in 38 sporting disciplines. ECG patterns were distinctly abnormal in 145 athletes (14%), mildly abnormal in 257 (26%), and

Antonio Pelliccia; Barry J. Maron; Franco Culasso; Fernando M. Di Paolo; Antonio Spataro; Alessandro Biffi; Giovanni Caselli; Paola Piovano

2010-01-01

389

SOFTWARE AGENTS IN HANDLING ABNORMAL SITUATIONS IN INDUSTRIAL PLANTS  

E-print Network

SOFTWARE AGENTS IN HANDLING ABNORMAL SITUATIONS IN INDUSTRIAL PLANTS Sami Syrjälä and Seppo Kuikka. The abnormal situation handling in industrial plants is a challenging application area due to the complexity-model, abnormal situation handling, industrial plants 1. Introduction This paper is based on the work made

390

A Case of ADHD and a Major Y Chromosome Abnormality  

Microsoft Academic Search

Background: ADHD is a common, heritable disorder of childhood. Sex chromosome abnormalities are relatively rare conditions that are sometimes associated with behavioral disorders. Method: The authors present a male child with ADHD and a major de-novo Y chromosome abnormality consisting of deletion of the long arm and duplication of the short arm. It is possible that the Y chromosomal abnormality

Aisling Mulligan; Michael Gill; Michael Fitzgerald

2008-01-01

391

Application of the Abnormally Dangerous Activities Doctrine to Environmental Cleanups  

Microsoft Academic Search

The common law tort doctrine of strict liability for abnormally dangerous activities is emerging as a key element of the law of hazardous substance regulation, which has been dominated by CERCLA. Recent applications of the abnormally dangerous activities doctrine have shown the doctrine's formidable potential for expansion. Together with the related torts of nuisance and trespass, strict liability for abnormally

Jim C. Chen; Kyle E. McSlarrow

1992-01-01

392

Some of the present problems of abnormal psychology  

Microsoft Academic Search

Discusses the problems surfacing in the field of abnormal psychology. Abnormal psychology has thrown much light on the mechanisms of normal mental processes, for disease dissects the mind and brings into view the mechanisms. In the department of medicine, it has furnished an intelligible explanation of many unexplained derangements of the mind. The problems of abnormal psychology are largely the

Morton Prince

1905-01-01

393

Chromosomal abnormalities associated with cyclopia and synophthalmia.  

PubMed Central

At the present time, essentially all known facts concerning cyclopia are consistent with some chromosomal disease, including clinical features of the pregnancy (fetal wastage, prematurity, intrauterine growth retardation, maternal age factor, complications of pregnancy), the generalized developmental abnormalities, specific ocular dysgenesis, by the high incidence of chromosomal abnormality already demonstrated, and the possibility of error in those cases of cyclopia with normal chromosomes. Even if chromosomal aberrations represent only one group of several different etiologic factors leading to cyclopia, at the present time chromosomal errors would seem to be the most common cause of cyclopia now recognized. Further studies will establish or disprove a chromosomal error in those instances which are now considered to be the result of an environmental factor alone or those with apparent familial patterns of inheritance. This apparent diverse origin of cyclopia can be clarified if future cyclopic specimens are carefully investigated. The evaluation should include a careful gross and microscopic examination of all organs, including the eye, and chromosome banding studies of all organs, including the eye, and chromosome banding studies of at least two cyclopic tissues. Then the presence or absence of multiple causative factors can be better evaluated. Images FIGURE 2 A FIGURE 2 B FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 1 D FIGURE 1 E FIGURE 1 F FIGURE 3 A FIGURE 3 B FIGURE 4 A FIGURE 4 B FIGURE 4 C FIGURE 4 D FIGURE 5 FIGURE 6 FIGURE 7 A FIGURE 7 B PMID:418547

Howard, R O

1977-01-01

394

Superior temporal gyrus spectral abnormalities in schizophrenia  

PubMed Central

Considerable evidence indicates early auditory stimulus processing abnormalities in schizophrenia, but the mechanisms are unclear. The present study examined oscillatory phenomena during a paired-click paradigm in the superior temporal gyrus (STG) as a possible core problem. The primary question addressed is whether first click and/or second click group differences in the time-domain evoked response in patients with schizophrenia are due to (1) group differences in the magnitude of poststimulus oscillatory activity, (2) group differences in poststimulus phase-locking, and/or (3) group differences in the magnitude of ongoing background oscillatory activity. Dense-array magnetoencephalography from 45 controls and 45 patients with schizophrenia produced left- and right-hemisphere STG 50- and 100-ms time-frequency evoked, phase-locking, and total power measures. Whereas first click 100-ms evoked theta and alpha abnormalities were observed bilaterally, evoked low beta-band differences were specific to the left hemisphere. Compared to controls, patients with schizophrenia showed more low-frequency phase variability, and the decreased 100-ms S1 evoked response observed in patients was best predicted by the STG phase-locking measure. PMID:18665866

EDGAR, J. CHRISTOPHER; HANLON, FAITH M.; HUANG, MING-XIONG; WEISEND, MICHAEL P.; THOMA, ROBERT J.; CARPENTER, BRUCE; HOECHSTETTER, KARSTEN; CANIVE, JOSE M.; MILLER, GREGORY A.

2009-01-01

395

Superior temporal gyrus spectral abnormalities in schizophrenia.  

PubMed

Considerable evidence indicates early auditory stimulus processing abnormalities in schizophrenia, but the mechanisms are unclear. The present study examined oscillatory phenomena during a paired-click paradigm in the superior temporal gyrus (STG) as a possible core problem. The primary question addressed is whether first click and/or second click group differences in the time-domain evoked response in patients with schizophrenia are due to (1) group differences in the magnitude of poststimulus oscillatory activity, (2) group differences in poststimulus phase-locking, and/or (3) group differences in the magnitude of ongoing background oscillatory activity. Dense-array magnetoencephalography from 45 controls and 45 patients with schizophrenia produced left- and right-hemisphere STG 50- and 100-ms time-frequency evoked, phase-locking, and total power measures. Whereas first click 100-ms evoked theta and alpha abnormalities were observed bilaterally, evoked low beta-band differences were specific to the left hemisphere. Compared to controls, patients with schizophrenia showed more low-frequency phase variability, and the decreased 100-ms S1 evoked response observed in patients was best predicted by the STG phase-locking measure. PMID:18665866

Edgar, J Christopher; Hanlon, Faith M; Huang, Ming-Xiong; Weisend, Michael P; Thoma, Robert J; Carpenter, Bruce; Hoechstetter, Karsten; Cañive, José M; Miller, Gregory A

2008-09-01

396

Functional neuroimaging abnormalities in idiopathic generalized epilepsy  

PubMed Central

Magnetic resonance imaging (MRI) techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE) is characterized by bilateral synchronous spike–wave discharges on electroencephalography (EEG) but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray–white blurring, fractional anisotropy (FA) measures from diffusion tensor imaging (DTI) and fractional amplitude of low frequency fluctuations (fALFF) in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray–white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC) subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE. PMID:25383319

McGill, Megan L.; Devinsky, Orrin; Wang, Xiuyuan; Quinn, Brian T.; Pardoe, Heath; Carlson, Chad; Butler, Tracy; Kuzniecky, Ruben; Thesen, Thomas

2014-01-01

397

Protruding labia minora: abnormal or just uncool?  

PubMed

There is a wide variety in the appearance of normal female external genitalia. Nevertheless a specific prototype is promoted by the media, leading to a false sense that all other appearances are abnormal. As adolescents become sexually aware at an earlier age, most of them are worried about the appearance of their genitalia, especially when labia minora protrude beyond labia majora. This is a prospective audit of adolescents presenting for assessment of their perceived abnormal genitalia. Sixteen girls aged 10.2 to 17.8 years presented between June 2009 and December 2010 to a specialist adolescent gynecology service. Their mean labial width was 36?mm (range: 20-55?mm). In six girls, the reason for attending the service was inequality of the size of labia ranging between 6?mm and 35?mm (mean of 20?mm). Among the remaining 10 girls, the concern had arisen through comparison with a prepubescent sibling (one case), change of genitalia during puberty (four cases), looking at internet pictures (four cases), and looking at an anatomy book (one case). Risks of Female Genital Cosmetic Surgery (FGCS) have not been adequately documented, especially with regards to sexual function and long-term patient satisfaction. External genitalia are likely to change during puberty and therefore, any genital operation in the absence of clear pathology should be deferred until adulthood. Even then, women should have clear expectations of what will be achieved with the operation in terms of appearance and function. PMID:21696338

Michala, Lina; Koliantzaki, Sofia; Antsaklis, Aris

2011-09-01

398

[A case presented mediastinal abnormal shadow].  

PubMed

A 29-year-old Japanese man was admitted to our hospital because of further examination of his mediastinal abnormal shadow on the chest roentogenogram detected in an annual medical examination. He was asymptomatic and had no abnormal findings on physical examination. A CT scan of the chest demonstrated a well marginated large tumor, 8 x 6 cm in size, in the anterior mediastinum. Non-invasive thymoma, malignant lymphoma (Hodgkin's disease, T-cell lymphoblastic lymphoma, mediastinal large cell lymphoma with sclerosis etc) or germ cell tumor were considered for differential diagnosis and diagnostic procedures were taken. Results of venous blood examination were normal except for high titer of beta-HCG (20.4 mIU/ml). With a transcutaneous biopsy of the mediastinal tumor, it was diagnosed mediastinal seminoma. A three weeks-interval chemotherapy composed of cisplatin, etoposide, and bleomycin was performed. After four cycles of this chemotherapy the residual mass was resected and no viable tumor cells were shown in the specimen. Germ cell tumor is usually treated with combination of chemotherapy, radiotherapy and surgical resection. However, mediastinal germ call tumor is not a common disease and it remains to be clarified which treatment modalities are adequate. But it is obvious that surgical resection should not be the initial choice of treatment. Medical oncologists must carefully perform the most appropriate modality at an optimal timing. PMID:9474935

Andoh, M; Narabayashi, M

1998-01-01

399

Abnormal elastic and vibrational behaviors of magnetite at high pressures.  

PubMed

Magnetite exhibits unique electronic, magnetic, and structural properties in extreme conditions that are of great research interest. Previous studies have suggested a number of transitional models, although the nature of magnetite at high pressure remains elusive. We have studied a highly stoichiometric magnetite using inelastic X-ray scattering, X-ray diffraction and emission, and Raman spectroscopies in diamond anvil cells up to ~20 GPa, while complementary electrical conductivity measurements were conducted in a cubic anvil cell up to 8.5 GPa. We have observed an elastic softening in the diagonal elastic constants (C11 and C44) and a hardening in the off-diagonal constant (C12) at ~8 GPa where significant elastic anisotropies in longitudinal and transverse acoustic waves occur, especially along the [110] direction. An additional vibrational Raman band between the A1g and T2g modes was also detected at the transition pressure. These abnormal elastic and vibrational behaviors of magnetite are attributed to the occurrence of the octahedrally-coordinated Fe(2+)-Fe(3+)-Fe(2+) ions charge-ordering along the [110] direction in the inverse spinel structure. We propose a new phase diagram of magnetite in which the temperature for the metal-insulator and distorted structural transitions decreases with increasing pressure while the charge-ordering transition occurs at ~8 GPa and room temperature. PMID:25186916

Lin, Jung-Fu; Wu, Junjie; Zhu, Jie; Mao, Zhu; Said, Ayman H; Leu, Bogdan M; Cheng, Jinguang; Uwatoko, Yoshiya; Jin, Changqing; Zhou, Jianshi

2014-01-01

400

Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures  

NASA Astrophysics Data System (ADS)

Magnetite exhibits unique electronic, magnetic, and structural properties in extreme conditions that are of great research interest. Previous studies have suggested a number of transitional models, although the nature of magnetite at high pressure remains elusive. We have studied a highly stoichiometric magnetite using inelastic X-ray scattering, X-ray diffraction and emission, and Raman spectroscopies in diamond anvil cells up to ~20 GPa, while complementary electrical conductivity measurements were conducted in a cubic anvil cell up to 8.5 GPa. We have observed an elastic softening in the diagonal elastic constants (C11 and C44) and a hardening in the off-diagonal constant (C12) at ~8 GPa where significant elastic anisotropies in longitudinal and transverse acoustic waves occur, especially along the [110] direction. An additional vibrational Raman band between the A1g and T2g modes was also detected at the transition pressure. These abnormal elastic and vibrational behaviors of magnetite are attributed to the occurrence of the octahedrally-coordinated Fe2+-Fe3+-Fe2+ ions charge-ordering along the [110] direction in the inverse spinel structure. We propose a new phase diagram of magnetite in which the temperature for the metal-insulator and distorted structural transitions decreases with increasing pressure while the charge-ordering transition occurs at ~8 GPa and room temperature.

Lin, Jung-Fu; Wu, Junjie; Zhu, Jie; Mao, Zhu; Said, Ayman H.; Leu, Bogdan M.; Cheng, Jinguang; Uwatoko, Yoshiya; Jin, Changqing; Zhou, Jianshi

2014-09-01

401

Influence of liquid temperature on the characteristics of an atmospheric dc glow discharge using a liquid electrode with a miniature helium flow  

NASA Astrophysics Data System (ADS)

An atmospheric dc glow discharge using a liquid cathode and an axial miniature helium flow was generated stably between a nozzle anode and an electrolyte cathode (NaCl solution) in ambient air. Under low-current operation, the typical structure of dc glow discharges, i.e. a negative glow, a Faraday dark space and positive column, was observed. With increasing discharge current, the visible negative glow became weak and was replaced by an intense yellow-light emission, which was considered to originate from sodium atoms vaporized from the electrolyte surface by local heating due to ion bombardment from the glow discharge. To examine the effect of the liquid electrode temperature on the discharge characteristics, we controlled the electrolyte cathode temperature using an injection-type cooler or heater. The intensity of the sodium emission decreased when the electrolyte cathode was cooled, while it increased when the electrolyte cathode was heated. When a pulse-modulated dc voltage was applied, the sodium emission appeared with a delay relative to the inception of discharge, while nitrogen molecular lines appeared in the emission spectra and reached their peak intensities immediately. The temperature of the liquid cathode is an important factor in controlling the plasma-liquid interaction from the discharge and in resolving the detailed mechanism of the electrolyte cathode discharge.

Shirai, Naoki; Ichinose, Kosuke; Uchida, Satoshi; Tochikubo, Fumiyoshi

2011-06-01

402

Heat and Radiofrequency Plasma Glow Discharge Pretreatment of a Titanium Alloy Promote Bone Formation and Osseointegration  

PubMed Central

Orthopedic and dental implants manifest increased failure rates when inserted into low density bone. We determined whether chemical pretreatments of a titanium alloy implant material stimulated new bone formation to increase osseointegration in vivo in trabecular bone using a rat model. Titanium alloy rods were untreated or pretreated with heat (600°C) or radiofrequency plasma glow discharge (RFGD). The rods were then coated with the extracellular matrix protein fibronectin (1 nM) or left uncoated and surgically implanted into the rat femoral medullary cavity. Animals were euthanized 3 or 6 weeks later, and femurs were removed for analysis. The number of trabeculae in contact with the implant surface, surface contact between trabeculae and the implant, and the length and area of bone attached to the implant were measured by histomorphometry. Implant shear strength was measured by a pull-out test. Both pretreatments and fibronectin enhanced the number of trabeculae bonding with the implant and trabeculae-to-implant surface contact, with greater effects of fibronectin observed with pretreated compared to untreated implants. RFGD pretreatment modestly increased implant shear strength, which was highly correlated (r2 = 0.87 – 0.99) with measures of trabecular bonding for untreated and RFGD-pretreated implants. In contrast, heat pretreatment increased shear strength 3 to 5-fold for both uncoated and fibronectin-coated implants at 3 and 6 weeks, suggesting a more rapid increase in implant-femur bonding compared to the other groups. In summary, our findings suggest that the heat and RFGD pretreatments can promote the osseointegration of a titanium alloy implant material. PMID:23649564

MacDonald, Daniel E.; Rapuano, Bruce E.; Vyas, Parth; Lane, Joseph M.; Meyers, Kathleen; Wright, Timothy

2013-01-01

403

Glow discharge with electrostatic confinement of electrons in a chamber bombarded by fast electrons  

NASA Astrophysics Data System (ADS)

A metal substrate is immersed in plasma of glow discharge with electrostatic confinement of electrons inside the vacuum chamber volume V ? 0.12 m3 filled with argon or nitrogen at pressures 0.005-5 Pa, and dependence of discharge characteristics on negative substrate potential is studied. Emitted by the substrate secondary electrons bombard the chamber walls and it results in electron emission growth of the chamber walls and rise of gas ionization intensity inside the chamber. Increase of voltage U between the chamber and the substrate up to 10 kV at a constant discharge current I d in the anode circuit results in a manifold rise of current I in the substrate circuit and decrease of discharge voltage U d between the anode and the chamber from hundreds to tens of volts. At pressure p < 0.05 Pa nonuniformity of plasma density does not exceed ˜10%. Using the Child-Langmuir law, as well as measurement results of sheath width d between homogeneous plasma and a lengthy flat substrate dependent on voltage U ion current density j i on the substrate surface and ion-electron emission coefficient ? i are calculated. After the current in circuit of a substrate made of the same material is measured, the ? i values may be used to evaluate the average dose of ion implantation. The rate of dose rise at a constant high voltage U is by an order of magnitude higher than in known systems equipped with generators of square-wave high-voltage pulses. Application to the substrate of 10-ms-wide sinusoidal high-voltage pulses, which follow each other with 100-Hz frequency, results in synchronous oscillations of voltage U and ion current I i in the substrate circuit. In this case variation of the sheath width d due to oscillations of U and Ii is insignificant and d does not exceed several centimeters thus enabling substrate treatment in a comparatively small vacuum chamber.

Metel, A. S.; Grigoriev, S. N.; Melnik, Yu. A.; Prudnikov, V. V.

2011-07-01

404

Etching of UO{sub 2} in NF{sub 3} RF Plasma Glow Discharge  

SciTech Connect

A series of room temperature, low pressure (10.8 to 40 Pa), low power (25 to 210 W) RF plasma glow discharge experiments with UO{sub 2} were conducted to demonstrate that plasma treatment is a viable method for decontaminating UO{sub 2} from stainless steel substrates. Experiments were conducted using NF{sub 3} gas to decontaminate depleted uranium dioxide from stainless-steel substrates. Depleted UO{sub 2} samples each containing 129.4 Bq were prepared from 100 microliter solutions of uranyl nitrate hexahydrate solution. The amorphous UO{sub 2} in the samples had a relatively low density of 4.8 gm/cm{sub 3}. Counting of the depleted UO{sub 2} on the substrate following plasma immersion was performed using liquid scintillation counting with alpha/beta discrimination due to the presence of confounding beta emitting daughter products, {sup 234}Th and {sup 234}Pa. The alpha emission peak from each sample was integrated using a gaussian and first order polynomial fit to improve quantification. The uncertainties in the experimental measurement of the etched material were estimated at about {+-} 2%. Results demonstrated that UO{sub 2} can be completely removed from stainless-steel substrates after several minutes processing at under 200 W. At 180 W and 32.7 Pa gas pressure, over 99% of all UO{sub 2} in the samples was removed in just 17 minutes. The initial etch rate in the experiments ranged from 0.2 to 7.4 {micro}m/min. Etching increased with the plasma absorbed power and feed gas pressure in the range of 10.8 to 40 Pa. A different pressure effect on UO{sub 2} etching was also noted below 50 W in which etching increased up to a maximum pressure, {approximately}23 Pa, then decreased with further increases in pressure.

John M. Veilleux

1999-08-01

405

Protein destruction by a helium atmospheric pressure glow discharge: Capability and mechanisms  

SciTech Connect

Biological sterilization represents one of the most exciting applications of atmospheric pressure glow discharges (APGD). Despite the fact that surgical instruments are contaminated by both microorganisms and proteinaceous matters, sterilization effects of APGD have so far been studied almost exclusively for microbial inactivation. This work presents the results of a detailed investigation of the capability of a helium-oxygen APGD to inactivate proteins deposited on stainless-steel surfaces. Using a laser-induced fluorescence technique for surface protein measurement, a maximum protein reduction of 4.5 logs is achieved by varying the amount of the oxygen admixture into the background helium gas. This corresponds to a minimum surface protein of 0.36 femtomole/mm{sup 2}. It is found that plasma reduction of surface-borne protein is through protein destruction and degradation, and that its typically biphasic reduction kinetics is influenced largely by the thickness profile of the surface protein. Also presented is a complementary study of possible APGD protein inactivation mechanisms. By interplaying the protein inactivation kinetics with optical emission spectroscopy, it is shown that the main protein-destructing agents are excited atomic oxygen (via the 777 and 844 nm emission channels) and excited nitride oxide (via the 226, 236, and 246 nm emission channels). It is also demonstrated that the most effective protein reduction is achieved possibly through a synergistic effect between atomic oxygen and nitride oxide. This study is a useful step toward a full confirmation of the efficacy of APGD as a sterilization technology for surgical instruments contaminated by prion proteins.

Deng, X. T.; Shi, J. J.; Kong, M. G. [Department of Electronic and Electrical Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)

2007-04-01

406

Role of cathode identity in liquid chromatography particle beam glow discharge mass spectrometry  

NASA Astrophysics Data System (ADS)

A detailed evaluation of the role of cathode identity on the analytical and spectral characteristics of various organic, organometallic and metal analytes using liquid chromatography-particle beam/glow discharge mass spectrometry (LC-PB/GDMS) has been carried out. A d.c. discharge, operating with argon as the support gas, was used throughout this work. In this study, Cu which has a relatively high sputtering rate, Ni which has moderate sputtering rate and Ta which has very low sputtering rate, are taken as cathode materials to study the ionization, fragmentation, and analytical characteristics of organic (caffeine, epigallocatechin gallate, peptide as representative compounds), organometallic (selenomethionine, triethyl lead chloride as representative compounds) and metal (Fe, La, Cs and Pb) species. A range of discharge gas pressures (26.6-106.4 Pa) and currents (0.2-1.5 mA) were investigated with the test cathodes to determine their influence on the spectral composition and overall analytical response for the various test species. Calibration plots were obtained for all of the species for each of the three cathodes to determine the respective limits of detection. Relative detection limits in the range of 0.02 to 15 ng mL - 1 (0.002-1.5 ng, absolute) for the test species were found to be in the order of Cu > Ni > Ta; which follows the order of the sputtering characteristics of the respective cathodes. These studies rendered information about the respective discharge parameters' role in choosing the most appropriate cathode identity in PB-GDMS for application in the areas of organic, organometallic and inorganic species analysis.

Krishna, M. V. Balarama; Marcus, R. K.

2008-06-01

407

ULTRAVIOLET INDUCED MOTION OF A FLUORESCENT DUST CLOUD IN AN ARGON DIRECT CURRENT GLOW DISCHARGE PLASMA  

SciTech Connect

Dusty plasmas consist of electrons, ions, neutrals and nm-?m sized particles commonly referred to as dust. In man-made plasmas this dust may represent impurities in a tokamak or plasma etching processing. In astrophysical plasmas this dust forms structures such as planetary rings and comet tails. To study dusty plasma dynamics an experiment was designed in which a 3:1 silica (<5 ?m diameter) and fl uorescent dust mixture was added to an argon DC glow discharge plasma and exposed to UV radiation. This fl uorescent lighting technique offers an advantage over laser scattering (which only allows two-dimensional slices of the cloud to be observed) and is simpler than scanning mirror techniques or particle image velocimetry. Under typical parameters (P=150 mTorr, V anode= 100 V, Vcathode= -400 V, Itotal < 2mA) when the cloud is exposed to the UV light (100W, ? = 365 nm) the mixture fl uoresces, moves ~2mm towards the light source and begins rotating in a clockwise manner (as seen from the cathode). By calibrating a UV lamp and adjusting the relative intensity of the UV with a variable transformer it was found that both translational and rotational velocities are a function of UV intensity. Additionally, it was determined that bulk cloud rotation is not seen when the dust tray is not grounded while bulk translation is. This ongoing experiment represents a novel way to control contamination in man-made plasmas and a path to a better understanding of UV-bathed plasma systems in space..

Hvasta, M.G.; and Zwicker, A.

2008-01-01

408

Atmospheric pressure glow discharge desorption mass spectrometry for rapid screening of pesticides in food.  

PubMed

Flowing afterglow atmospheric pressure glow discharge tandem mass spectrometry (APGD-MS/MS) is used for the analysis of trace amounts of pesticides in fruit juices and on fruit peel. The APGD source was rebuilt after Andrade et al. (Andrade et al., Anal. Chem. 2008; 80: 2646-2653; 2654-2663) and mounted onto a hybrid quadrupole time-of-flight mass spectrometer. Apple, cranberry, grape and orange juices as well as fruit peel and salad leaves were spiked with aqueous solutions containing trace amounts of the pesticides alachlor, atrazine, carbendazim, carbofuran, dinoseb, isoproturon, metolachlor, metolcarb, propoxur and simazine. Best limits of determination (LODs) of pesticides in the fruit juices were achieved for metolcarb (1 microg/L in apple juice), carbofuran and dinoseb (2 microg/L in apple juice); for the analysis of apple skin best LODs were 10 pg/cm(2) of atrazine, metolcarb and propoxur which corresponds to an estimated concentration of 0.01 microg/kg apple, taking into account the surface area and the weight of the apple. The measured LODs were within or below the allowed maximum residue levels (MRLs) decreed by the European Union (1-500 microg/kg for pesticides in fruit juice and 0.01-5 microg/kg for apple skin). No sample pretreatment (extraction, pre-concentration, chromatographic separation) was necessary to analyze these pesticides by direct desorption/ionization using APGD-MS and to identify them using MS/MS. This makes APGD-MS a powerful high-throughput tool for the investigation of very low amounts of pesticides in fruit juices and on fruit peel/vegetable skin. PMID:18697232

Jecklin, Matthias Conradin; Gamez, Gerardo; Touboul, David; Zenobi, Renato

2008-09-01

409

Use of Helium Production to Screen Glow Discharges for Low Energy Nuclear Reactions (LENR)  

NASA Astrophysics Data System (ADS)

My working hypothesis of the conditions required to observe low energy nuclear reactions ( LENR ) follows: 1) High fluxes of deuterium atoms through interfaces of grains of metals that readily accommodate movement of hydrogen atoms interstitially is the driving variable that produces the widely observed episodes of excess heat above the total of all input energy. 2) This deuterium atom flux has been most often achieved at high electrochemical current densities on highly deuterium-loaded palladium cathodes but is clearly possible in other experimental arrangements in which the metal is interfacing gaseous deuterium, as in an electrical glow discharge. 3) Since the excess heat episodes must be producing the product(s) of some nuclear fusion reaction(s) screening of options may be easier with measurement of those "ashes" than the observance of the excess heat. 4) All but a few of the exothermic fusion reactions known among the first 5 elements produce He-4. Hence helium-4 appearance in an experiment may be the most efficient indicator of some fusion reaction without commitment on which reaction is occurring. This set of hypotheses led me to produce a series of sealed tubes of wire electrodes of metals known to absorb hydrogen and operate them for >100 days at the <1 watt power level using deuterium gas pressures of ˜100 torr powered by 40 Khz AC power supplies. Observation of helium will be by measurement of helium optical emission lines through the glass envelope surrounding the discharge. The results of the first 18 months of this effort will be described.

Passell, Thomas O.

2011-03-01

410

Effects of radiofrequency glow discharge and oligopeptides on the attachment of human endothelial cells to polyurethane.  

PubMed

Activation of the surface of small diameter polyurethane vascular grafts using radiofrequency glow discharge (RFGD) and covalent linkage of cell attachment oligopeptides may improve graft patency. The effects of RFGD treatment were investigated on a polyurethane-polydimethylsiloxane (PU-PDMS) copolymer (Cardiothane-51; Kontron Cardiovascular, Inc., Everett, MA) membrane fabricated using the spray, phase-inversion technique. RFGD using H2O vapor was used to functionalize the membrane surface, reacted with 1',1 carbonyldiimidazole and covalently bound with oligopeptides (RGDS, RGES). Membranes not subjected to RFGD, either unmodified or with adsorbed fibronectin (Fn), vitro-nectin (Vn), RGDS, RGDV, and RGES, were used as controls. RFGD treated membrane surfaces were evaluated using electron spectroscopy for chemical analysis, which demonstrated a qualitative increase in nitrogen and silicon compared to unmodified PU-PDMS. Indirect confirmation of surface hydroxylation was provided by metallization with palladium and nickel, demonstrating uniform metallization of RFGD treated PU-PDMS surfaces. Human umbilical vein endothelial cells (HUVEC) were seeded at a density of 10(4) cells/cm2 and cell attachment assessed at 3 hr, 24 hr, and 7 days. Untreated PU-PDMS and membrane with adsorbed oligopeptides demonstrated poor HUVEC attachment at all intervals. Adsorbed Fn and Vn had significantly better early cell attachment and growth (p < 0.01). RFGD improved initial attachment and growth over non-RFGD treated controls (p < 0.01) for RGDS bound membranes, which performed as well as Fn controls (N.S.). PU-PDMS membranes can be modified using RFGD to covalently link oligopeptides. RFGD treatment alone, or with covalent linkage of cell attachment oligopeptides, improves HUVEC attachment and growth in a static environment. PMID:8573880

Patterson, R B; Messier, A; Valentini, R F

1995-01-01

411

Heat and Radiofrequency Plasma Glow Discharge Pretreatment of a Titanium Alloy: Eveidence for Enhanced Osteoinductive Properties  

PubMed Central

It is believed that orthopedic and implant longevity can be improved by optimizing fixation, or direct bone-implant contact, through the stimulation of new bone formation around the implant. The purpose of this study was to determine whether heat (600°C) or radiofrequency plasma glow discharge (RFGD) pretreatment of Ti6Al4V stimulated calcium-phosphate mineral formation in cultures of attached MC3T3 osteoprogenitor cells with or without a fibronectin coating. Calcium-phosphate mineral was analyzed by flame atomic absorption spectrophotometry, scanning electron microscopy (SEM)/electron dispersive X-ray microanalysis (EDAX) and Fourier transformed infrared spectroscopy (FTIR). RFGD and heat pretreatments produced a general pattern of increased total soluble calcium levels, although the effect of heat pretreatment was greater than that of RFGD. SEM/EDAX showed the presence of calcium-and phosphorus-containing particles on untreated and treated disks that were more numerous on fibronectin-coated disks. These particles were observed earliest (1 week) on RFGD-pretreated surfaces. FTIR analyses showed that the heat pretreatment produced a general pattern of increased levels of apatite mineral at 2–4 weeks; a greater effect was observed for fibronectin-coated disks compared to uncoated disks. The observed findings suggest that heat pretreatment of Ti6Al4V increased the total mass of the mineral formed in MC3T3 osteoprogenitor cell cultures more than RFGD while the latter pretreatment hastened the early deposition of mineral. These findings help to support the hypothesis that the pretreatments enhance the osteoinductive properties of the alloy. PMID:23494951

Rapuano, Bruce E.; Singh, Herman; Boskey, Adele L.; Doty, Stephen B.; MacDonald, Daniel E.

2013-01-01

412

Investigation of spectrochemical matrix effects in the liquid sampling-atmospheric pressure glow discharge source  

NASA Astrophysics Data System (ADS)

The liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma was evaluated with regard to its spectrochemical robustness in its application as a miniaturized optical emission spectroscopy (OES) source for liquid samples. The susceptibility to perturbations in excitation/ionization conditions was probed across a wide range test species, including transition metals, easily ionized elements (group I), and elements with low second ionization potentials (group II). Spectrochemical metrics included the plasma excitation temperature (Texc), ionization temperatures (Tion), and magnesium (Mg) ionic:atomic (Mg II:Mg I) ratios. The introduction of the 11 different matrix elements into the LS-APGD at concentrations of 500 ?g mL- 1 yielded no significant changes in the optically-determined plasma characteristics, indicating a relative immunity to spectrochemical matrix effects. Texe values for the plasma, using He I as the spectrometric species averaged 2769 ± 79 K across the test matrix, with Mg-based ionization temperature values centered at 6665 ± 151 K. Typical Mg II:Mg I ratios (the so-called robustness parameter) were 0.95 ± 0.3. The lack of appreciable perturbation in excitation/ionization conditions observed here is also manifested in virtually no changes in the probe Mg II and I species' intensities, even at matrix loadings of up to 1000 ?g mL- 1 of Ba. These observations indicate that the LS-APGD could serve as an OES source for the analysis of diverse aqueous samples without appreciable spectroscopic matrix effects, though potential physical matrix effects including vaporization effects must be evaluated.

Manard, Benjamin T.; Gonzalez, Jhanis J.; Sarkar, Arnab; Mao, Xianglei; Zhang, Lynn X.; Konegger-Kappel, Stefanie; Marcus, R. Kenneth; Russo, Richard E.

2014-10-01

413

Novel application of the electrolyte cathode atmospheric glow discharge: Atomic absorption spectrometry studies  

NASA Astrophysics Data System (ADS)

The analytical characteristics of a capillary design of the electrolyte cathode atmospheric glow discharge (ELCAD), operated with a W-rod anode at a discharge current of 70 mA and a discharge voltage of 950 V, were exploited through spatially resolved atomic absorption spectrometry (AAS) experiments. For this purpose, the ELCAD cell, placed on a platform adjustable with micrometer screws, was inserted into the optical path of a commercial line-source AAS instrument. A flow injection system was developed and applied to introduce 3 mL of aqueous standards of a set of environmentally relevant metals (Ca, Cd, Cr, Cu, Na, Pb and Zn) into the plasma. The analyte atom distribution along the vertical axis of the conically-shaped ELCAD plasma (height: 3.5 mm) is element specific. All the absorbance maxima are observed in the near cathode region (e.g., in the range of 0.5-1.0 mm from the cathode), while the AA signal smoothly fades towards the anode. Several spectrochemical buffers (citric acid, EDTA, chlorides of Ca, Cs, La, Li, and Na) were studied for improving the sensitivity of the AAS determinations for Cr. A significant increase in the sensitivity (20%) was found only with the addition of 0.55% (m/v) La solution. The limit of detection data for Cd, Cu, Na and Zn are 3.4, 4.2, 9.2 and 0.9 mg L- 1, respectively. The AAS calibration curves for Cd, Cu, Na and Zn are linear up to 75, 200, 100 and 25 mg L- 1, respectively.

György, Krisztina; Bencs, László; Mezei, Pál; Cserfalvi, Tamás

2012-11-01

414

Large mode radius resonators  

NASA Technical Reports Server (NTRS)

Resonator configurations permitting operation with large mode radius while maintaining good transverse mode discrimination are considered. Stable resonators incorporating an intracavity telescope and unstable resonator geometries utilizing an output coupler with a Gaussian reflectivity profile are shown to enable large radius single mode laser operation. Results of heterodyne studies of pulsed CO2 lasers with large (11mm e sup-2 radius) fundamental mode sizes are presented demonstrating minimal frequency sweeping in accordance with the theory of laser-induced medium perturbations.

Harris, Michael R.

1987-01-01

415

The End of Days -- Chandra Catches X-ray Glow From Supernova  

NASA Astrophysics Data System (ADS)

Through a combination of serendipity and skill, scientists have used NASA's Chandra X-ray Observatory to capture a rare glimpse of X-radiation from the early phases of a supernova, one of the most violent events in nature. Although more than a thousand supernovas have been observed by optical astronomers, the early X-ray glow from the explosions has been detected in less than a dozen cases. The Chandra observations were made under the direction of a team of scientists from the Massachusetts Institute of Technology (MIT) in Cambridge, led by Walter Lewin and his graduate student, Derek Fox. When combined with simultaneous observations by radio and optical telescopes, the X-ray observations tell about the thickness of the shell that was blown off, its density, its speed, and how much material was shed by the star before it exploded. Chandra observed an X-ray glow from SN1999em with the total power of 50,000 suns. Ten days later it observed the supernova for another nine hours, and found that the X rays had faded to half their previous intensity. The optical luminosity, which had the brightness of 200 million suns, had faded somewhat less. No radio emission was detected at any time. With this information, the MIT group and their colleagues are already piecing together a picture of the catastrophic explosion. Observations by optical astronomers showed that SN1999em was a Type II supernova produced by the collapse of the core of a star ten or more times as massive as the Sun. The intense heat generated in the collapse produces a cataclysmic rebound that sends high speed debris flying outward at speeds in excess of 20 million miles per hour. The debris crashes into matter shed by the former star before the explosion. This awesome collision generates shock waves that heat expanding debris to three million degrees. The X-ray glow from this hot gas was detected by Chandra and gives astrophysicists a better understanding of the dynamics of the explosion, as well as the behavior of the doomed star in the years before the explosion. "The combination of X-ray detection and radio non-detection is unusual, but may have less to do with the supernova and more to do with the great sensitivity of Chandra," said Roger Chevalier of University of Virginia, Charlottesville. Chevalier explained that the combined observations indicate that SN1999em shed a relatively small amount of matter before it exploded, compared to other supernovas observed in X rays. The Chandra observation is important because it may represent a more common type of supernova. The Chandra observation also provides an inside look at the hectic, exciting world of the international "quick response" network that scientists have set up to track and investigate supernovas. On Friday, October 29, Alex Fillipenko of the University of California, Berkeley notified Bob Kirshner at Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., that his automated supernova search project had a good candidate in a relatively nearby spiral galaxy, NGC 1637. Nearby in this case means about 25 million light years from Earth. Wei Dong Li, who is visiting Fillipenko's group from the Beijing Astronomical Observatory in China, called his colleagues in Beijing, who confirmed the supernova when the Earth rotated into a position to make viewing from China possible. The astronomers also notified the International Astronomical Union's central bureau for astronomical telegrams in Cambridge, Mass., from which the discovery was broadcast worldwide. Radio astronomers Christina Lacey and Kurt Weiler at the Naval Research Laboratory in Washington, D.C., Schuyler van Dyk at the California Institute of Technology, Pasadena and Richard Sramek at the National Radio Astronomy Observatory's Very Large Array, Socorro, N.M. were alerted. Kirshner then got in touch via e-mail with Harvey Tananbaum, director of the Chandra X-ray Center at Harvard-Smithsonian a little before 11 p.m. on Saturday night. The Chandra operations team replanned the telescope's observation activities and by Monday mor

1999-12-01

416

Is Rolandic Epilepsy Associated With Abnormal Findings On Cranial MRI?  

PubMed Central

Rolandic epilepsy (RE) is designated an idiopathic epilepsy syndrome, and hence no lesional abnormalities are expected on MRI exam. Recent reports suggest that MRI abnormalities are not only common, but may be specific for temporal lobe epilepsy, and lateralized to the side of EEG discharges. However, no controlled study has been performed to test the hypothesis of association between MRI abnormalities and Rolandic epilepsy. We performed an unmatched case-control study to test the hypothesis of association between MRI abnormalities and Rolandic epilepsy, using 25 typical RE cases and 25 children with migraine. Two independent examiners rated the MRIs for abnormalities. Examiners were blinded to the study hypothesis and identity of case and control exams. Fifty-two percent of RE exams contained at least one abnormality: peri/hippocampal abnormality (1 case), non-localized congenital malformation (7 cases), subcortical parenchymal hyperintensities (2 cases), periventricular parenchymal hyperintensities (1 case), dilated perivascular spaces (6 cases). There was no difference between the number or type of abnormalities in cases and controls. No type of abnormality lateralized to the hemisphere from which the EEG spikes emanated. The odds ratio of association between MRI abnormalities and RE was 0.87, 95% CI: 0.18–4.33 after adjusting for potential demographic and technical factors. We conclude that routine cranial MRI abnormalities are common in RE, but no more common than in controls, and not specific for RE. PMID:17624735

Boxerman, Jerrold L.; Hawash, Karameh; Bali, Bhavna; Clarke, Tara; Rogg, Jeffrey; Pal, Deb K

2007-01-01

417

Observation and analysis of abnormal absorption signals in laser flash photolysis measurement  

NASA Astrophysics Data System (ADS)

In order to investigate a noise-like signal appearing in dynamic mode measurement during laser flash photolysis experiments, five compounds were chosen which show this abnormal phenomenon. The reproducibility of this phenomenon was done repeatedly, indicating that it originates from each molecular structural property. Also their two regulation pattern or features were found by our analysis. One is a U-shaped curve of main frequency intensity with time and it seems to be directly related to the concentration of the T1 excited state. The other is a high damping oscillation curve of the frequency shift with time and this curve seems to be indicating an energy transportation process from light into chemical energy. Finally, a possible origin of hydrogen nuclear optical resonance was proposed for the abnormal signal.

Li, Wen; Yuan, Yao-feng; Li, Xiao-lin; Su, Xiao-long; Sun, Wen-hua

2013-03-01

418

Development of an atmospheric-pressure homogeneous and cold Ar/O{sub 2} plasma source operating in glow discharge  

SciTech Connect

An atmospheric-pressure Ar/O{sub 2} glow discharge is generated in a parallel bare metal plate reactor with a radio-frequency power supply by introducing a dielectric strip in the inlet of the gas flow. The role of the dielectric strip is discussed experimentally. The allowable oxygen-to-argon ratio reaches 1.0 vol % and the generated Ar/O{sub 2} plasma discharge is characterized by a low gas temperature and good spatial homogeneity, implying its feasible application as a type of material treatment for a large-area surface, as illustrated experimentally by the ashing of carbon black.

Li Shouzhe; Wu Qi; Zhang Jialiang; Wang Dezhen [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); Uhm, Han S. [Kwangwoon Academy of Advanced Studies, Kwangwoon University, 447-1 Wolgye-dong, Nowon-gu, Seoul 137-701 (Korea, Republic of)

2010-06-15

419

Multi-scale dynamics of glow discharge plasma through wavelets: Self-similar behavior to neutral turbulence and dissipation  

E-print Network

The multiscale dynamics of glow discharge plasma is analysed through wavelet transform, whose scale dependent variable window size aptly captures both transients and non-stationary periodic behavior. The optimal time-frequency localization ability of the continuous Morlet wavelet is found to identify the scale dependent periodic modulations efficiently, as also the emergence of neutral turbulence and dissipation, whereas the discrete Daubechies basis set has been used for detrending the temporal behavior to reveal the multi-fractality of the underlying dynamics. The scaling ex- ponents and the Hurst exponent have been estimated through wavelet based detrended fluctuation analysis,and also Fourier methods and rescale range analysis.

Bapun K. Giri; Chiranjit Mitra; Prasanta K. Panigrahi; A. N. Sekar Iyengar

2014-01-13

420

Fragment L of Comet Shoemaker-Levy 9 slams into Jupiter near the still glowing remnant of the older  

NASA Technical Reports Server (NTRS)

Fragment L of Comet Shoemaker-Levy 9 slams into Jupiter near the still glowing remnant of the older K impact. In the upper left frame, only the K site is visible. The images were taken starting (top left) at 22:11 UT on July 19 (5:11 p.m. Chicago time). Subsequent images were taken at 22:20, 22:27, 22:39, 22:44 and 22:59 UT. These near infrared images were taken with the South Pole Infrared Explorer (SPIREX), a 24 inch telescope at the south pole. SPIREX team members are Mark Hereld, Hien Nguyen, Bernard Rauscher, and Scott Severson.

2002-01-01

421

Chromosome abnormalities in patients with syndactyly.  

PubMed

Chromosome studies on 105 patients with syndactyly included two trisomy-21 mongols, a chromatin-positive boy with 47, XXY, a chromatin-negative short girl with 45,X0 and a boy with a familial D/D translocation. Chromosome patterns were normal in the other cases which included three patients with acrocephalosyndactyly and one patient with oro-facial-digital syndrome.The incidence of chromosome abnormalies was greater than expected since syndactyly of the fingers is uncommon in the chromosome disorders.THIS INCIDENCE MAY BE RELATED TO THE INCREASED MATERNAL AGE (MEAN: 29.4 years) of the syndactyly group compared to maternal age (mean: 26.64 years) of the control group although, paradoxically, four mothers of the five patients with chromosome abnormalities were young. PMID:4310631

Conen, P E; Hampole, M K; Thomson, H G

1969-11-15

422

Pleural abnormalities: thoracic ultrasound to the rescue!  

PubMed

Diaphragmatic hernias that are diagnosed in adulthood may be traumatic or congenital in nature. Therefore, respiratory specialists need to be aware of the presentation of patients with these conditions. In this report, we describe a case series of patients with congenital and traumatic diaphragmatic hernias and highlight a varied range of their presentations. Abnormalities were noted in the thorax on the chest radiographs, but it was unclear as to the nature of the anomaly. The findings on thoracic ultrasound conducted by a pulmonologist helped to direct appropriate investigations avoiding unnecessary interventions. Instead of pleural effusions, consolidation or collapse, thoracic computed tomography demonstrated diaphragmatic hernias which were managed either conservatively or by surgery. There is increasing evidence that pulmonary specialists should be trained in thoracic ultrasonography to identify pleural pathology as well as safely conducting pleural-based interventions. PMID:23819018

Aslam, Imran; Pathmanathan, Sega; Lakshminarayana, Umesh B; Avery, Gerard R; Kastelik, Jack A; Morjaria, Jaymin B

2013-07-01

423

Pharmacological therapy for abnormal uterine bleeding.  

PubMed

Pharmacological therapies for the treatment of abnormal uterine bleeding are effective and generally well tolerated. This review presents an evidence-based approach to medical therapy. Selection depends on the etiology and amount of bleeding, need for contraception or preservation of fertility, perimenopause status, and medication efficacy and adverse effects.Available nonhormonal agents include nonsteroidal anti-inflammatory agents, which reduce bleeding by 25% to 35% and improve dysmenorrhea through reduced prostaglandin levels; tranexamic acid, which inhibits plasminogen activator with a 40% to 60% reduction in menstrual blood loss; and intranasal desmopressin, which is an antifibrinolytic for women with an underlying bleeding disorder (eg, von Willebrand disease).Hormonal regimens cause the inhibition of endometrial growth. Cyclic progestogen therapy for 21 days results in a significant reduction in menstrual blood loss. Limited data suggest that oral contraceptives reduce menstrual blood loss by 40% to 50% with decreased breast tenderness and dysmenorrhea and a reduction in risk of uterine and ovarian cancer. The progestin-releasing intrauterine devices are effective up to 97% by 6 months and provide relief of dysmenorrhea and contraception. Long-acting progestogen injections produce amenorrhea and provide contraception but are associated with irregular spotting and reversible bone loss. Danazol leads to endometrial atrophy with a reduced menstrual loss; androgenic adverse effects may be lessened with lower doses or vaginal use. Gonadotrophin agonists lead to ovarian suppression and are used to shrink fibroids or the endometrium preoperatively but are limited by hypoestrogenic adverse events. Emergency use of parenteral conjugated estrogens has a 70% chance of stopping abnormal bleeding but an increased risk of thrombosis. PMID:21701432

Pinkerton, JoAnn V

2011-04-01

424

Metabolic Abnormalities in Children with Asthma  

PubMed Central

Rationale: Childhood asthma and obesity have reached epidemic proportions worldwide, and the latter is also contributing to increasing rates of related metabolic disorders, such as diabetes. Yet, the relationship between asthma, obesity, and abnormal lipid and glucose metabolism is not well understood, nor has it been adequately explored in children. Objectives: To analyze the relationship between asthma diagnosis and body mass in children across the entire range of weight percentile categories, and to test the hypothesis that early derangement in lipid and glucose metabolism is independently associated with increased risk for asthma. Methods: Cross-sectional analysis of a representative sample of public school children from a statewide community-based screening program, including a total of 17,994 children, 4 to 12 years old, living in predominantly rural West Virginia, and enrolled in kindergarten, second, or fifth grade classrooms. Measurements and Main Results: We analyzed demographics; family history; smoke exposure; parent-reported asthma diagnosis; body mass index; evidence of acanthosis nigricans as a marker for developing insulin resistance; and fasting serum lipid profile including total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. Regardless of their body mass index percentile, children diagnosed with asthma were more likely than children without asthma to have higher triglyceride levels and acanthosis nigricans after controlling for sex differences and smoke exposure. Conclusions: This study provides the first set of community-based data linking asthma, body mass, and metabolic variables in children. In particular, these findings uniquely describe a statistically significant association between asthma and abnormal lipid and glucose metabolism beyond body mass index associations. PMID:20851922

Cottrell, Lesley; Neal, William A.; Ice, Christa; Perez, Miriam K.; Piedimonte, Giovanni

2011-01-01

425

Abnormal electroretinogram associated with developmental brain anomalies.  

PubMed Central

PURPOSE: We have encountered abnormal ERGs associated with optic nerve hypoplasia, macular, optic nerve and chorioretinal colobomata and developmental brain anomalies. Brain anomalies include cortical dysgenesis, lissencephaly, porencephaly, cerebellar and corpus callosum hypoplasia. We describe six exemplar cases. METHODS: Scotopic and photopic ERGs adherent to international standards were performed as well as photopic ERGs to long-duration stimuli. CT or MRI studies were also done. The ERGs were compared to age-matched normal control subjects. RESULTS: ERG changes include reduced amplitude b-waves to blue and red stimuli under scotopic testing conditions. Implicit times were often delayed. The photopic responses also showed reduced amplitude a- and b-waves with implicit time delays. The long-duration photopic ERG done in one case shows attenuation of both ON- and OFF-responses. CONCLUSIONS: Common underlying developmental genetic or environmental unifying casualties are speculated to be at fault in causing these cases of associated retinal and brain abnormalities. No single etiology is expected. Multiple potential causes acting early in embryogenesis effecting neuronal induction, migration and differentiation are theorized. These occur at a time when brain and retinal cells are sufficiently undifferentiated to be similarly effected. We call these cases examples of Brain Retina Neuroembryodysgenesis (BRNED). Homeobox and PAX genes with global neuronal developmental influences are gene candidates to unify the observed disruption of brain and retinal cell development. The ERG can provide a valuable clinical addition in understanding and ultimately classifying these disorders. Images FIGURE 1 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 PMID:8719676

Cibis, G W; Fitzgerald, K M

1995-01-01

426

Filling the vacuum chamber of a technological system with homogeneous plasma using a stationary glow discharge  

NASA Astrophysics Data System (ADS)

Experimental study of a glow discharge with electrostatic confinement of electrons is carried out in the vacuum chamber volume V ? 0.12 m3 of a technological system “Bulat-6” in argon pressure range 0.005-5 Pa. The chamber is used as a hollow cathode of the discharge with the inner surface area S ? 1.5 m2. It is equipped with two feedthroughs, which make it possible to immerse in the discharge plasma interchangeable anodes with surface area S a ranging from ˜0.001 to ˜0.1 m2, as well as floating electrodes isolated from both the chamber and the anode. Dependences of the cathode fall U c = 0.4-3 kV on the pressure p at a constant discharge current in the range I = 0.2-2 A proved that aperture of the electron escape out of the electrostatic trap is equal to the sum S o = S a + S f of the anode surface S a and the floating electrode surface S f . The sum S o defines the lower limit p o of the pressure range, in which U c is independent of p. At p < p o the cathode fall U c grows up dramatically, when the pressure decreases, and the pressure p tends to the limit p ex, which is in fact the discharge extinction pressure. At p ? p ex electrons emitted by the cathode and the first generation of fast electrons produced in the cathode sheath spend almost all their energy up to 3 keV on heating the anode and the floating electrode up to 600-800°C and higher. In this case the gas in the chamber is being ionized by the next generations of electrons produced in the cathode sheath, their energy being one order of magnitude lower. When S a < (2 m/ M)1/2 S, where m is the electron mass and M is the ion mass, the anode may be additionally heated by plasma electrons accelerated by the anode fall of potential U a up to 0.5 kV.

Metel, A. S.; Grigoriev, S. N.; Melnik, Yu. A.; Panin, V. V.

2009-12-01

427

Effect of hydrogen ratio on plasma parameters of N{sub 2}-H{sub 2} gas mixture glow discharge  

SciTech Connect

A dc plane glow discharge in a nitrogen-hydrogen (N{sub 2}-H{sub 2}) gas mixture has been operated at discharge currents of 10 and 20 mA. The electron energy distribution function (EEDF) at different hydrogen concentrations is measured. A Maxwellian EEDF is found in the positive column region, while in both cathode fall and negative glow regions, a non-Maxwellian one is observed. Langmuir electric probes are used at different axial positions, gas pressures, and hydrogen concentrations to measure the electron temperature and plasma density. The electron temperature is found to increase with increasing H{sub 2} concentration and decrease with increasing both the axial distance from the cathode and the mixture pressure. At first, with increasing distance from the cathode, the ion density decreases, while the electron density increases; then, as the anode is further approached, they remain nearly constant. At different H{sub 2} concentrations, the electron and ion densities decrease with increasing the mixture pressure. Both the electron and ion densities slightly decrease with increasing H{sub 2} concentration.

El-Brulsy, R. A.; Abd Al-Halim, M. A.; Abu-Hashem, A. [Benha University, Physics Department, Faculty of Science (Egypt); Rashed, U. M. [Alazhar University, Physics Department, Faculty of Science (Egypt); Hassouba, M. A. [Benha University, Physics Department, Faculty of Science (Egypt)

2012-05-15

428

Characterization of argon direct-current glow discharge with a longitudinal electric field applied at ambient air  

NASA Astrophysics Data System (ADS)

A direct-current-driven plasma jet is developed by applying a longitudinal electric field on the flowing argon at ambient air. This plasma shows a torch shape with its cross-section increased from the anode to the cathode. Comparison with its counterparts indicates that the gas flow plays a key role in variation of the plasma structure and contributes much to enlarging the plasma volume. It is also found that the circular hollow metal base promotes generation of plasma with a high-power volume density in a limited space. The optical emission spectroscopy (OES) diagnosis indicates that the plasma comprises many reactive species, such as OH, O, excited N2, and Ar metastables. Examination of the rotational and vibrational temperature indicates that the plasma is under nonequilibrium condition and the excited species OH(A 2?+), O(5P), and N2(C 3?u) are partly generated by energy transfer from argon metastables. The spatially resolved OES of plasma reveals that the negative glow, Faraday dark space, and positive column are distributed across the gas gap. The absence of the anode glow is attributed to the fact that many electrons in the vicinity of the anode follow ions into the positive column due to the ambipolar diffusion in the flowing gas.

Jiang, Weiman; Tang, Jie; Wang, Yishan; Zhao, Wei; Duan, Yixiang

2014-09-01

429

Carbon dioxide reforming of methane by pulsed glow discharge at atmospheric pressure: The effect of pulse compression  

SciTech Connect

Methane reforming by carbon dioxide in pulsed glow discharge at atmospheric pressure is examined. The plasma pulse is compressed to less than 50 ns. This compression enables one to work at higher frequencies, over 3 kHz, without glow-arc transition. The main products of the reaction are synthetic gases (H{sub 2}, CO) and C{sub 2} hydrocarbons. Approximately 42% of plasma energy goes to the chemical dissociation, when the reactant ratio is CO{sub 2}/CH{sub 4}=1. At this point, the energy expense is less than 3.8 eV per converted molecule while reactant conversions are relatively high reaching to 55% (CH{sub 4}) and 42% (CO{sub 2}). The reactor energy performance even gets better at higher CO{sub 2}/CH{sub 4} ratios. While energy efficiency reached about 45%, at feed ratio of CO{sub 2}/CH{sub 4}=5, the conversions of about 65% and 45% were obtained for methane and carbon dioxide, respectively. A model describing dissociation through molecular vibrations is introduced. According to the model, the high nonequilibrium state of vibrational energy at short pulses leads to this improvement, especially in carbon dioxide.

Ghorbanzadeh, A. M.; Modarresi, H. [Department of Physics, Tehran University, North Kargar Avenue, Tehran 1439955961 (Iran, Islamic Republic of); School of Mechanical Engineering, Sharif University of Technology, Tehran 11365-9567 (Iran, Islamic Republic of)

2007-06-15

430

Application of a tuned Langmuir probe for the diagnostic study of radio frequency glow discharges: instrumentation and theory  

NASA Astrophysics Data System (ADS)

A computer-controlled, tuned Langmuir probe system has been designed and implemented for the diagnostic study of analytical, radio frequency (r.f.) glow discharge sources. Use of an impedance-tuned probe eliminates deleterious effects created by the capacitive character of the r.f. plasma-induced probe sheath. Results indicate that r.f.-induced distortion of the probe characteristic does exist, but can be effectively mitigated by the use of the tuned probe. An automated Langmuir probe acquisition and processing system for the r.f. glow discharge plasma is developed to obtain complete and undistorted current-voltage ( i- V) curves over a wide potential range (± 100 V) with typical curves generated in less than 1 1/2min, though acquisition time can be less than 1 s. Various Langmuir probe theories are reviewed and evaluated for their suitability in the characterization of these plasmas. Evidence indicates that the collisionless theories can be effectively employed to evaluate the obtained i- V curves and to derive the parameters of electron temperature, electron average energy, electron density and ion density.

Ye, Yuancai; Marcus, R. Kenneth

1995-08-01

431

Elevated frequency of abnormalities in barn swallows from Chernobyl.  

PubMed

Ever since the Chernobyl accident in 1986, that contaminated vast areas in surrounding countries with radiation, abnormalities and birth defects have been reported in human populations. Recently, several studies suggested that the elevated frequency of such abnormalities can be attributed to poverty and stress in affected human populations. Here, we present long-term results for a free-living population of barn swallows, Hirundo rustica, demonstrating the presence of 11 morphological abnormalities in populations around Chernobyl, but much less frequently in an uncontaminated Ukrainian control population and three more distant control populations. The presence of these abnormalities in barn swallows is associated with reduced viability. These findings demonstrate a link between morphological abnormalities and radiation in an animal population that cannot be attributed to poverty and stress. The most parsimonious hypothesis for abnormalities in animal and human populations alike is that the effects are caused by the same underlying cause, viz. radiation derived from the Chernobyl accident. PMID:17439847

Møller, A P; Mousseau, T A; de Lope, F; Saino, N

2007-08-22

432

The time of onset of abnormal calcification in spondylometaepiphyseal dysplasia, short limb-abnormal calcification type.  

PubMed

A 1-month-old boy with shortness of extremities on prenatal US was referred to our department with a provisional diagnosis of achondroplasia. His height was normal but he had short extremities and platyspondyly, premature carpal epiphyses on both hands, and short tubular bones with irregular metaphyses on radiographs. Re-evaluation of the patient at the age of 1 year revealed very short height and premature calcification of the costal cartilages and epiphyses. Spondylometaepiphyseal dysplasia (SMED), short limb-abnormal calcification type was diagnosed. This condition is a very rare autosomal recessively inherited disorder, and most of the patients die in early childhood due to neurological involvement. At the age of 2 years and 5 months, a CT scan showed narrowing of the cervical spinal canal. One month later he died suddenly because of spinal cord injury. In conclusion early diagnosis is very important because the recurrence risk is high and patients may die due to early neurological complications. The time of onset of abnormal calcifications, a diagnostic finding of the disease, is at the age of around 1 year in most patients. When abnormal calcifications are not yet present, but radiological changes associated with SMED are present, this rare disease must be considered. PMID:19002453

Tüysüz, Beyhan; Gazio?lu, Nurperi; Ungür, Sava?; Aji, Dolly Yafet; Türkmen, Seval

2009-01-01

433

Review of congenital inner ear abnormalities on CT temporal bone  

PubMed Central

The aetiology of profound hearing loss in children is complex and multifactorial. Congenital inner ear abnormality is a major cause of hearing loss in children. CT temporal bone imaging is the modality of choice in the investigation of hearing loss. Recognising the congenital abnormalities of the inner ear guides the clinician's management of the condition. This pictorial essay illustrates the congenital abnormalities of the inner ear on high resolution CT temporal bone images and correlation with developmental arrest during embryology. PMID:21849370

Yiin, R S Z; Tang, P H; Tan, T Y

2011-01-01

434

Ordinary electromagnetic mode instability  

NASA Technical Reports Server (NTRS)

The instability of the ordinary electromagnetic mode propagating perpendicular to an external magnetic field is studied for a single-species plasma with ring velocity distribution. The marginal instability boundaries for both the purely growing mode and the propagating growing modes are calculated from the instability criteria. The dispersion characteristics for various sets of plasma parameters are also given. The typical growth rates are of the order of the cyclotron frequency.

Cheng, C. Z.

1974-01-01

435

Neoclassical Tearing Modes  

SciTech Connect

Tearing modes often limit the performance of tokamak plasmas, because the magnetic islands which they generate lead to a loss of confinement, or even a disruption. A particularly dangerous instability is the neoclassical tearing mode, which can grow to a large amplitude because of the amplification effect that the bootstrap current has on an initial 'seed' magnetic island. This paper will address the mechanisms which dominate the neoclassical tearing mode evolution, and thereby identify possible control techniques.

Wilson, H.R. [EURATOM/UKAEA Fusion Association (United Kingdom)

2004-03-15

436

Chandra Resolves Cosmic X-ray Glow and Finds Mysterious New Sources  

NASA Astrophysics Data System (ADS)

While taking a giant leap towards solving one of the greatest mysteries of X-ray astronomy, NASA's Chandra X-ray Observatory also may have revealed the most distant objects ever seen in the universe and discovered two puzzling new types of cosmic objects. Not bad for being on the job only five months. Chandra has resolved most of the X-ray background, a pervasive glow of X-rays throughout the universe, first discovered in the early days of space exploration. Before now, scientists have not been able to discern the background's origin, because no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. "This is a major discovery," said Dr. Alan Bunner, Director of NASA's Structure andEvolution of the universe science theme. "Since it was first observed thirty-seven years ago, understanding the source of the X-ray background has been aHoly Grail of X-ray astronomy. Now, it is within reach." The results of the observation will be discussed today at the 195th national meeting of the American Astronomical Society in Atlanta, Georgia. An article describing this work has been submitted to the journal Nature by Dr. Richard Mushotzky, of NASA Goddard Space Flight Center, Greenbelt, Md., Drs. Lennox Cowie and Amy Barger at the University of Hawaii, Honolulu, and Dr. Keith Arnaud of the University of Maryland, College Park. "We are all very excited by this finding," said Mushotzky. "The resolution of most of the hard X-ray background during the first few months of the Chandra mission is a tribute to the power of this observatory and bodes extremely well for its scientific future," Scientists have known about the X-ray glow, called the X-ray background, since the dawn of X-ray astronomy in the early 1960s. They have been unable to discern its origin, however, for no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. The German-led ROSAT mission, now completed, resolved much of the lower-energy X-ray background, showing that it arose in very faraway galaxies with extremely bright cores, called quasars or Active Galactic Nuclei (AGN). The Chandra team sampled a region of the sky about one-fifth the angular area of a full moon and resolved about 80 percent of the more-energetic X-ray background into discrete sources. Stretched across the entire sky, this would account for approximately 70 million sources, most of which would be identified with galaxies. Their analysis confirms that a significant fraction of the X-ray background cannot be due to diffuse radiation from hot, intergalactic gas. Combined X-ray and optical observations showed that nearly one third of the sources are galaxies whose cores are very bright in X rays yet emit virtually no optical light from the core. The observation suggests that these "veiled galactic nuclei" galaxies may number in the tens of millions over the whole sky. They almost certainly harbor a massive black hole at their core that produces X rays as the gas is pulled toward it at nearly the speed of light. Their bright X-ray cores place these galaxies in the AGN family. Because these numerous AGN are bright in X rays, but optically dim, the Chandra observation implies that optical surveys of AGN are very incomplete. A second new class of objects, comprising approximately one-third of the background, is assumed to be "ultra-faint galaxies." Mushotzky said that these sources may emit little or no optical light, either because the dust around the galaxy blocks the light totally or because the optical light is eventually absorbed by relatively cool gas during its long journey across the universe. In the latter scenario, Mushotzky said that these sources would have a redshift of 6 or higher, meaning that they are well over 14 billion light years away and thus the earliest, most distant objects ever identified. "This is a very exciting discovery," said Dr. Alan Bunner, Director of NASA's Structure and Evolution of the universe science theme. "Since it

2000-01-01

437

SAMPEX special pointing mode  

NASA Technical Reports Server (NTRS)

A new pointing mode has been developed for the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) spacecraft. This pointing mode orients the instrument boresights perpendicular to the field lines of the Earth's magnetic field in regions of low field strength and parallel to the field lines in regions of high field strength, to allow better characterization of heavy ions trapped by the field. The new mode uses magnetometer signals and is algorithmically simpler than the previous control mode, but it requires increased momentum wheel activity. It was conceived, designed, tested, coded, uplinked to the spacecraft, and activated in less than seven months.

Markley, F. Landis; Flatley, Thomas W.; Leoutsakos, Theodore

1995-01-01

438

Asymmetric Bessel modes.  

PubMed

We propose a new, three-parameter family of diffraction-free asymmetric elegant Bessel modes (aB-modes) with an integer and fractional orbital angular momentum (OAM). The aB-modes are described by the nth-order Bessel function of the first kind with complex argument. The asymmetry degree of the nonparaxial aB-mode is shown to depend on a real parameter c?0: when c=0, the aB-mode is identical to a conventional radially symmetric Bessel mode; with increasing c, the aB-mode starts to acquire a crescent form, getting stretched along the vertical axis and shifted along the horizontal axis for c?1. On the horizontal axis, the aB-modes have a denumerable number of isolated intensity zeros that generate optical vortices with a unit topological charge of opposite sign on opposite sides of 0. At different values of the parameter c, the intensity zeros change their location on the horizontal axis, thus changing the beam's OAM. An isolated intensity zero on the optical axis generates an optical vortex with topological charge n. The OAM per photon of an aB-mode depends near-linearly on c, being equal to ?(n+cI1(2c)/I0(2c)), where ? is the Planck constant and In(x) is a modified Bessel function. PMID:24979002

Kotlyar, V V; Kovalev, A A; Soifer, V A

2014-04-15

439

Myelodysplastic syndromes: pathogenesis, functional abnormalities, and clinical implications.  

PubMed Central

The myelodysplastic syndromes represent a preleukaemic state in which a clonal abnormality of haemopoietic stem cell is characterised by a variety of phenotypic manifestations with varying degrees of ineffective haemopoiesis. This state probably develops as a sequence of events in which the earliest stages may be difficult to detect by conventional pathological techniques. The process is characterised by genetic changes leading to abnormal control of cell proliferation and differentiation. Expansion of an abnormal clone may be related to independence from normal growth factors, insensitivity to normal inhibitory factors, suppression of normal clonal growth, or changes in the immunological or nutritional condition of the host. The haematological picture is of peripheral blood cytopenias: a cellular bone marrow, and functional abnormalities of erythroid, myeloid, and megakaryocytic cells. In most cases marrow cells have an abnormal DNA content, often with disturbances of the cell cycle: an abnormal karyotype is common in premalignant clones. Growth abnormalities of erythroid or granulocyte-macrophage progenitors are common in marrow cultures, and lineage specific surface membrane markers indicate aberrations of differentiation. Progression of the disorder may occur through clonal expansion or through clonal evolution with a greater degree of malignancy. Current attempts to influence abnormal growth and differentiation have had only limited success. Clinical recognition of the syndrome depends on an acute awareness of the signs combined with the identification of clonal and functional abnormalities. PMID:2999194

Jacobs, A

1985-01-01

440

Metabolic Abnormalities in Abstinent Methamphetamine Dependent Subjects  

PubMed Central

Introduction: Chronic methamphetamine use results in persistent neuropsychological deficits in abstinent methamphetamine dependent (AMD) subjects. We examined the hypothesis that elevated concentration of cerebral glutamate (Glu), an excitatory neurotransmitter and neurotoxin, occurs in human AMD. Materials and Methods: We examined 40 subjects, 18 of whom were AMD, abstinent more than 3 weeks and 22 were age matched controls. A Structured Clinical Interview was applied to exclude AMD with comorbid depression. We used TE-Averaged technique of MRS to uniquely identify and quantify the glutamate resonance at 2.35 ppm on a 3T clinical MR scanner. Statistics, including Bonferroni correction for multiple MRS variables were applied. Results: Glu was significantly higher in frontal white matter of AMD (+19%, P = 0.01) and N-acetylaspartate (NAA), an axonal marker, was lower (?14%, P = 0.004). No significant MRS abnormalities were detected in posterior gray matter. Significant correlations were observed between NAA and Glu (P = 0.002 for AMD and P = 0.06 for controls in the posterior gray matter and P = 0.01 for controls and not significant for AMD in the frontal white matter). Conclusion: Our results demonstrate a significant excess of glutamate in frontal white matter of AMD subjects and offer support for the hypothesis that methamphetamine abuse may exert its long-term neuro-toxicity via glutamate. PMID:20485533

Sailasuta, Napapon; Abulseoud, Osama; Hernandez, Martha; Haghani, Poone; Ross, Brian D

2010-01-01

441

Cardiovascular Abnormalities in Sickle Cell Disease  

PubMed Central

Sickle cell disease is characterized by recurrent episodes of ischemia-reperfusion injury to multiple vital organ systems and a chronic hemolytic anemia, both contributing to progressive organ dysfunction. The introduction of treatments that induce protective fetal hemoglobin and reduce infectious complications has greatly prolonged survival. However, with increased longevity, cardiovascular complications are increasingly evident, with the notable development of a progressive proliferative systemic vasculopathy, pulmonary hypertension (PH) and left ventricular diastolic dysfunction. Pulmonary hypertension is reported in autopsy studies and numerous clinical studies have shown that increased pulmonary pressures are an important risk marker for mortality in these patients. In epidemiological studies, the development of PH is associated with intravascular hemolysis, cutaneous leg ulceration, renal insufficiency, iron overload and liver dysfunction. Chronic anemia in sickle cell disease results in cardiac chamber dilation and a compensatory increase in left ventricular mass. This is often accompanied by left ventricular diastolic dysfunction which has also been a strong independent predictor of mortality patients with sickle cell disease. Both PH and diastolic dysfunction are associated with marked abnormalities in exercise capacity in these patients. Sudden death is an increasingly recognized problem and further cardiac investigations are necessary to recognize and treat high-risk patients. PMID:22440212

Gladwin, Mark T.; Sachdev, Vandana

2013-01-01

442

Abnormal Microvascular Reactivity with Hypercholesterolaemia in Pregnancy  

PubMed Central

Background: Post-occlusive skin reactive hyperaemia (PORH) is a model used to assess microvascular reactivity. This study aims to compare PORH response among pregnant hypercholesterolaemic patients with age and gestational age-matched controls. Methods: This cross sectional study involved 17 hypercholesterolaemic, pregnant women and 20 pregnant controls entering their early third trimester. Laser Doppler fluximetry (LDF) was used to measure skin perfusion. The process of PORH was performed by occluding the upper arm with an occlusion cuff at 200 mmHg for 3 minutes. Skin perfusion was recorded before, during, and after occlusion release. Baseline perfusion, time to achieve peak perfusion (Tp), peak perfusion after occlusion release (PORHpeak), and maximum change in perfusion due to occlusion (PORHmax) were recorded. Results: Serum total cholesterol (TC) was significantly different (P < 0.001) between the 2 groups: 7.25 (SEM 0.18) mmol/L for hypercholesterolaemic women and 5.54 (SEM 0.15) mmol/L for the control group. There were no significant differences in their baseline, PORHpeak, and PORHmax. However, Tp in the hypercholesterolaemic group was significantly increased (P = 0.024) compared with the controls at 14.9 (SEM 0.6) seconds and 13.1 (SEM 0.5) seconds, respectively. Conclusion: Pregnant hypercholesterolaemic patients showed an abnormal microvascular reactivity response. Tp with ischemia was significantly increased compared with normocholesterolaemic controls. PMID:22135556

Rasool, Aida Hanum Ghulam; Abdul Rahman, Aisyah Syairah; Abd Ghaffar, Nor Aliza; Nik Mahmood, Nik Mohd Zaki; Wong, Abd Rahim

2010-01-01

443

Atypical Protein Kinase C in Cardiometabolic Abnormalities  

PubMed Central

Purpose Review aberrations of insulin signaling to atypical protein kinase C (aPKC) in muscle and liver that generate cardiovascular risk factors, including, obesity, hypertriglyceridemia, hypercholesterolemia, insulin resistance and glucose intolerance in type 2 diabetes mellitus (T2DM), and obesity-associated metabolic syndrome (MetSyn). Recent Findings aPKC and/or Akt mediate insulin effects on glucose transport in muscle, and synthesis of lipids, cytokines and glucose in liver. In T2DM, whereas Akt and aPKC activation are diminished in muscle, and hepatic Akt activation is diminished, hepatic aPKC activation is conserved. Imbalance between muscle and hepatic aPKC activation (and expression of PKC-? in humans) by insulin results from differential downregulation of insulin receptor substrates that control phosphatidylinositol 3-kinase. Conserved activation of hepatic aPKC in hyperinsulinemic states of T2DM, obesity and MetSyn is problematic as excessive activation of aPKC-dependent lipogenic, gluconeogenic and proinflammatory pathways increases cardiovascular risk factors. Indeed, selective inhibition of hepatic aPKC by adenoviral-mediated expression of kinase-inactive aPKC, or newly-developed small-molecule biochemicals, dramatically improves abdominal obesity, hepatosteatosis, hypertriglyceridemia, hypercholesterolemia, insulin resistance and glucose intolerance in murine models of obesity and T2DM. Summary Hepatic aPKC is a unifying target for treating multiple clinical abnormalities that increase cardiovascular risk in insulin-resistant states of obesity, MetSyn and T2DM. PMID:22449812

Farese, Robert V.; Sajan, Mini P.

2012-01-01

444

[Gastrointestinal abnormalities in children with autism].  

PubMed

The autistic spectrum disorder (ASD) is a neurodevelopmental disorder characterized by socially aloof behavior and impairment of language and social interaction. This paper is a review of literature on gastrointestinal problems in children with ASD. Gastrointestinal symptoms are described in 9-54% of autistic children, among which most common are: constipation, diarrhea and abdominal distension. The gastro-intestinal abnormalities reported in autism include: inflammation (esophagitis, gastritis, duodenitis, enterocolitis) with or without autoimmunity, lymphoid nodular hyperplasia, increased intestinal permeability, low activities of disaccharidase enzymes, impairment of detoxification (e.g. defective sulfation of ingested phenolic amines), dysbiosis with bacterial overgrowth, food intolerance or exorphin intoxication (by opioid derived from casein and gluten). A beneficial effect of dietary intervention on behavior and cognition of some autistic children indicates a functional relationship between the alimentary tract and the central nervous system. There are no epidemiologic data concerning the incidence or prevalence of gastrointestinal problems within the population of children with ASD in comparison to the population of non-ASD children. PMID:19650428

Wasilewska, Jolanta; Jarocka-Cyrta, Elzbieta; Kaczmarski, Maciej

2009-07-01

445

Thyroid abnormalities after therapeutic external radiation  

SciTech Connect

The thyroid gland is the largest pure endocrine gland in the body and one of the organs most likely to produce clinically significant abnormalities after therapeutic external radiation. Radiation doses to the thyroid that exceed approximately 26 Gy frequently produce hypothyroidism, which may be clinically overt or subclinical, as manifested by increased serum thyrotropin and normal serum-free thyroxine concentrations. Pituitary or hypothalamic hypothyroidism may arise when the pituitary region receives doses exceeding 50 Gy with conventional, 1.8-2 Gy fractionation. Direct irradiation of the thyroid may increase the risk of Graves` disease or euthyroid Graves` ophthalmopathy. Silent thyroiditis, cystic degeneration, benign adenoma, and thyroid cancer have been observed after therapeutically relevant doses of external radiation. Direct or incidental thyroid irradiation increases the risk for well-differentiated, papillary, and follicular thyroid cancer from 15- to 53-fold. Thyroid cancer risk is highest following radiation at a young age, decreases with increasing age at treatment, and increases with follow-up duration. The potentially prolonged latent period between radiation exposure and the development of thyroid dysfunction, thyroid nodularity, and thyroid cancer means that individuals who have received neck or pituitary irradiation require careful, periodic clinical and laboratory evaluation to avoid excess morbidity. 39 refs.

Hancock, S.L.; McDougall, I.R. [Stanford Univ. School of Medicine, Stanford, CA (United States)] [Stanford Univ. School of Medicine, Stanford, CA (United States); Constine, L.S. [Strong Memorial Hospital, Rochester, NY (Unite