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1

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

SciTech Connect

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?×?10{sup 4} 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., E-mail: liudingxin@gmail.com, E-mail: mglin5g@gmail.com [Center for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi (China); Nie, Q. Y.; Li, H. P. [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Chen, H. L. [Frank Reidy Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Kong, M. G., E-mail: liudingxin@gmail.com, E-mail: mglin5g@gmail.com [Center for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi (China); Frank Reidy Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States)

2014-05-19

2

On a Self-Sustained Oscillating Mode for Operation of a Glow Discharge  

NASA Astrophysics Data System (ADS)

A self-sustained oscillating mode for operation of a hollow cathode discharge (HCD) is analyzed based on a equivalent glow discharge RCL scheme. The oscillation takes place under i-V operating point of positive differential resistance and its frequency (approx kHz) depends on the discharge current value. The oscillation arising is found to require reasonable date values characterizing glow discharge plasma in general.

Zhechev, D.; Steflekova, V.

2008-07-01

3

An abnormal mode of torsion pendulum and its suppression  

NASA Astrophysics Data System (ADS)

The numerical solution of non-linear equations shows that the abnormal mode observed in our torsion pendulum experiments is an intrinsic mode of the pendulum. Further analysis shows that the amplitude of abnormal mode increasing with of swing modes can be suppressed with a magnetic damper effectively.

Tu, Ying; Zhao, Liang; Liu, Qi; Ye, Hong-Ling; Luo, Jun

2004-11-01

4

Abnormal activity of default mode network in GERD patients  

PubMed Central

Background Abnormal processing of esophageal sensation at the level of the central nervous system has been proven to be involved in gastroesophageal reflux disease (GERD). However, most studies were focused on the possible functions of perceptual processing related network during task status, little attention has been paid to default mode network, which has been manifested to be important in the pathogenesis of many diseases. In our study, we compared the brain activity characteristic in GERD patients with the healthy subjects (HS) at baseline, looking for whether activities of default mode network were abnormal in GERD patients and attempting to identify their possible roles in GERD. In present study, fractional amplitude of low-frequency fluctuation was adopted to detect the brain activities at baseline. Group-level analyses were conducted by one-sample t test within groups (voxel thresholds were p?42, corrected P?90, corrected P?mode network such as medial superior frontal gyrus, precuneus, posterior cingulate gyrus, etc. However, the activities of precuneus and posterior cingulate gyrus were significantly lower in GERD patients than those in the HS. Conclusions The activities of precuneus and posterior cingulate gyrus of default mode network in GERD patients were significantly lower compared to the HS, suggesting abnormal activities of brain regions in default mode network may be involved in pathophysiology of GERD symptom generation. PMID:23844702

2013-01-01

5

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

6

Self-sustained unstable modes for operation of glow discharge. An application  

NASA Astrophysics Data System (ADS)

Two self-sustained unstable modes for operation dependent on the operating i-V point are observed in a hollow cathode discharge (HCD). They manifest themselves as either galvanic oscillation or pulsation. The instabilities take place under i-V sections of both positive and negative differential resistance. The frequency f of the instabilities is found depending on the current discharge value i. The function f(i) is a precondition some deviations of the both gas pressure and purity fixed to be noticed.

Steflekova, V.; Slavov, D.; Zhechev, D.; Todorov, G.

2008-07-01

7

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

PubMed

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 the whispering gallery mode. PMID:25121685

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

2014-07-15

8

The Effect of Abnormal Granulation on Acoustic Wave Travel Times and Mode Frequencies  

E-print Network

Observations indicate that in plage areas (i.e. in active regions outside sunspots) acoustic waves travel faster than in quiet sun, leading to shortened travel times and higher p-mode frequencies. While it is clear that the ultimate cause of any difference between quiet sun and plage is the presence of magnetic fields of order 100 G in the latter, the mechanism by which the magnetic field exerts its influence has not yet been conclusively identified. One possible such mechanism is suggested by the observation that granular motions in plage areas tend to be slightly ``abnormal'', dampened compared to quiet sun. In this paper we consider the effect that abnormal granulation observed in active regions should have on the propagation of acoustic waves. Any such effect is found to be limited to a shallow surface layer where sound waves propagate nearly vertically. The magnetically suppressed turbulence implies higher sound speeds, leading to shorter travel times. This time shift Dt is independent of the travel distance, while it shows a characteristic dependence on the assumed plage field strength. As a consequence of the variation of the acoustic cutoff with height, Dt is expected to be significantly higher for higher frequency waves within the observed regime of 3-5 mHz. The lower group velocity near the upper reflection point further leads to an increased envelope time shift, as compared to the phase shift. $p$-mode frequencies in plage areas are increased by a corresponding amount, Dnu/nu = nu*Dt. These characteristics of the time and frequency shifts are in accordance with observations. The calculated overall amplitude of the time and frequency shifts are comparable to, but still significantly (factor of 2 to 5) less than suggested by measurements.

K. Petrovay; R. Erdelyi; M. J. Thompson

2007-02-02

9

Oscillations in glow discharges  

E-print Network

OSCILLATIONS IN GLOW DISCHARGES A Dissertation By Tom Prickett, Jr. June 1950 Approved as to style and content by Chairman of Committee OSCILLATIONS IN GLOW DISCHARGES A Dissertation By Tom Prickett, Jr* June 1950 OSCILLATIONS IN GLOW...* Comparison of Frequencies with Pierce*s Equation........................................ ?Jj-7 VI. Mobility of G a s e s .................................... I4.9 OSCILLATIONS IN GLOW DISCHARGES INTRODUCTION In a library investigation of the different...

Prickett, Tom

2013-10-04

10

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

11

Glow in the Dark  

NSDL National Science Digital Library

Learners experiment to see which colors of light will cause a phosphorescent (glow-in-the-dark) material to glow. Different colors of light have different wavelengths, and different amounts of energy. Only the colors which shine with sufficient energy can charge up the phosphorescent material enough to glow in the dark. This activity starts on p.26 of the manual. This manual contains four activities related to the Spectra: The Original Laser Superhero Force comic book published by the American Physical Society.

2012-12-27

12

Abnormal electron-heating mode and formation of secondary-energetic electrons in pulsed microwave-frequency atmospheric microplasmas  

SciTech Connect

The formation of secondary energetic electrons induced by an abnormal electron-heating mode in pulsed microwave-frequency atmospheric microplasmas was investigated using particle-in-cell simulation. We found that additional high electron heating only occurs during the first period of the ignition phase after the start of a second pulse at sub-millimeter dimensions. During this period, the electrons are unable to follow the abruptly retreating sheath through diffusion alone. Thus, a self-consistent electric field is induced to drive the electrons toward the electrode. These behaviors result in an abnormal electron-heating mode that produces high-energy electrons at the electrode with energies greater than 50?eV.

Kwon, H. C. [Department of Electrical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of) [Department of Electrical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Research and Development Division, SK Hynix Semiconductor Inc., Icheon 467-701 (Korea, Republic of); Jung, S. Y. [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of)] [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Kim, H. Y.; Won, I. H.; Lee, J. K., E-mail: jkl@postech.ac.kr [Department of Electrical Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2014-03-15

13

Glow: Living Lights  

NSDL National Science Digital Library

This 48-page Teacher's Guide accompanies the "Glow: Living Lights" exhibit at the San Diego Natural History Museum. In PDF format, the guide contains 12 lesson plans that explore the chemical compounds and adaptations of bioluminescence, symbiosis, fireflies and other "glowing" terrestrial animals, dinoflagellates, ocean submersibles, blue vs. bright red light, the organization of life, defense, mating, and predator/prey mechanisms of bioluminescent organisms, human applications, and potential research and careers in science.

2009-07-28

14

Glow-worms  

Microsoft Academic Search

SHELLEY sings of a ``glow-worm golden in a dell of dew,'' but last night, at 10 o'clock, while travelling on a bridle path among the bleak lonely mountains of Tynron, Dumfriesshire, bearing up against a high wind with cold rain, I espied three glow-worms shining among the grass and ferns. I had seen them in the same locality before, but

J. S

1879-01-01

15

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

Microsoft Academic Search

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,

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

2010-01-01

16

Asymmetric superradiant scattering and abnormal mode amplification induced by atomic density distortion.  

PubMed

The superradiant Rayleigh scattering using a pump laser incident along the short axis of a Bose-Einstein condensate with a density distortion is studied, where the distortion is formed by shocking the condensate utilizing the residual magnetic force after the switching-off of the trapping potential. We find that very small variation of the atomic density distribution would induce remarkable asymmetrically populated scattering modes by the matter-wave superradiance with long time pulse. The optical field in the diluter region of the atomic cloud is more greatly amplified, which is not an ordinary mode amplification with the previous cognition. Our numerical simulations with the density envelop distortion are consistent with the experimental results. This supplies a useful method to reflect the geometric symmetries of the atomic density profile by the superradiance scattering. PMID:23787626

Wang, Zhongkai; Niu, Linxiao; Zhang, Peng; Wen, Mingxuan; Fang, Zhen; Chen, Xuzong; Zhou, Xiaoji

2013-06-17

17

Abnormal Brain Default-Mode Network Functional Connectivity in Drug Addicts  

Microsoft Academic Search

BackgroundThe default mode network (DMN) is a set of brain regions that exhibit synchronized low frequency oscillations at resting-state, and is believed to be relevant to attention and self-monitoring. As the anterior cingulate cortex and hippocampus are impaired in drug addiction and meanwhile are parts of the DMN, the present study examined addiction-related alteration of functional connectivity of the DMN.MethodologyResting-state

Ning Ma; Ying Liu; Xian-Ming Fu; Nan Li; Chang-Xin Wang; Hao Zhang; Ruo-Bing Qian; Hu-Sheng Xu; Xiaoping Hu; Da-Ren Zhang; Ben Harrison

2011-01-01

18

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

19

The Glow-worm  

Microsoft Academic Search

ALTHOUGH in several Natural History Encyclopædias Scotland is excluded from the list of countries containing the glow-worm, I can aver that in Nithsdale and in the parish of Tynron, Dumfriesshire, they are quite plentiful. Yestreen, in Tynron, I ohserved one, to my surprise, shining by the wayside. It is a proof of the mildness of the season, no doubt, as

J. Shaw

1876-01-01

20

Science Nation: Glowing Squid  

NSDL National Science Digital Library

In deep ocean waters, it's sometimes difficult to hide from predators. That's why so many sea creatures have evolved extraordinary methods of disguise. Cephalopods, such as octopus, squid and cuttlefish, are big on camouflage, by day or night. In fact, the Hawaiian bobtail squid has several means of stealthy self- preservation. With support from the National Science Foundation (NSF), a team from the University of Wisconsin-Madison study one bobtail squid camouflage scheme; one that glows in the dark!

21

Light of Glow-worms  

Microsoft Academic Search

THE letter by Dr. Ramdas and Dr. Venkiteshwaran1 on the ``Spectrum of Glow-worm'' will surely arouse interest in the fascinating subject of animal luminescence and stimulate photophysical research on the phenomenon. The writers note that their worm glowed only by night, could be stimulated by shaking, and that the light was apparently under voluntary control. These details I am able

Michael Perkins

1931-01-01

22

Glow-Worms nu Snails  

Microsoft Academic Search

YOUR correspondent, Mr. R. S. Newall, has unconsciously reversed the natural condition of affairs in his note (NATURE, vol. xx. p. 197). The heading should have been as above Glow-worms devour snails, which are their natural food. The particular snail in question had probably been attacked by the one of the glow-worms, which had left some of its phosphorescent matter

R. McLachlan

1879-01-01

23

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

24

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

25

THz imaging of inexpensive glow discharge detector (GDD) pixel  

Microsoft Academic Search

A new kind of 8??8 focal plane array (FPA) based on glow discharge detector (GDD) elements was constructed and tested experimentally. First THz images of this FPA are presented. The data acquisition of this system is performed with a special VLSI board designed for this system. Switching mode is necessary in order to save energy and video rate operation. Recent

N. S. Kopeika; A. Abramovich; H. Joseph; A. Akram; O. Yadid-Pecht; A. Belenky; S. Lineykin

2009-01-01

26

Modeling of asymmetric pulsed phenomena in dielectric-barrier atmospheric-pressure glow discharges  

SciTech Connect

Asymmetric current pulses in dielectric-barrier atmospheric-pressure glow discharges are investigated by a self-consistent, one-dimensional fluid model. It is found that the glow mode and Townsend mode can coexist in the asymmetric discharge even though the gas gap is rather large. The reason for this phenomenon is that the residual space charge plays the role of anode and reduces the gap width, resulting in the formation of a Townsend discharge.

Ha Yan [College of Mathematics and Computer Science, Hebei University, Baoding 071002 (China); Wang Huijuan [School of Mathematics and Physics, North China Electric Power University, Baoding 071003 (China); Wang Xiaofei [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)

2012-01-15

27

Mode of initial presentation and chromosomal abnormalities in Irish patients with Turner syndrome: a single-centre experience.  

PubMed

Abstract Background: Age at diagnosis of girls with Turner syndrome (TS) is an important indicator of successful management. We determined the age, initial clinical presentation, and chromosomal abnormalities in patients with TS. Methods: This was a retrospective evaluation of the clinical and laboratory records of patients with TS. Results: Sixty-five patients with TS were identified; 40 (62%) were diagnosed after age 5 years. The main presenting features were short stature, delayed puberty, dysmorphic features, and neonatal lymphoedema. Chromosomal analysis of this cohort showed that 31 patients demonstrated mosaicism, while a 45,X karyotype was observed in 19. The remaining patients had variable abnormalities including deletion, translocation, isochromosome, and ring chromosome. Y-chromosome material was found in four cases. Conclusions: Most patients with TS were diagnosed after age 5 years, had a varied clinical presentation, and had a wide range of chromosomal abnormalities. PMID:25381945

Mohamed, Sarar; Roche, Edna F; Hoey, Hilary M C V

2014-11-01

28

Mechanistic investigations of shuttle glow  

SciTech Connect

A series of laboratory measurements have been performed in order to provide a mechanistic interpretation for the visible shuttle glow. These studies involved interactions in an 8 km/s oxygen atom beam with both contaminant dosed surfaces and gaseous targets. The authors conclude that visible shuttle glow arises from surface mediated O + NO recombination via a Langmuir-Hinshelwood mechanism and that the gas-phase exchange reaction O + N[sub 2] [r arrow] NO + N provides a viable source of precursor NO above surfaces oriented in the ram direction. 35 refs., 4 figs.

Caledonia, G.E.; Holtzclaw, K.W.; Krech, R.H.; Sonnenfroh, D.M. (Physical Sciences Inc., Andover, MA (United States)); Leone, A. (Lockhead Palo Alto Research Lab., CA (United States)); Blumber, W.A.M. (Hanscom Air Force Base, Bedford, MA (United States))

1993-03-01

29

GlowFit—a new tool for thermoluminescence glow-curve deconvolution  

Microsoft Academic Search

A new computer program, GlowFit, for deconvoluting first-order kinetics thermoluminescence (TL) glow-curves has been developed. A non-linear function describing a single glow-peak is fitted to experimental points using the least squares Levenberg–Marquardt method. The main advantage of GlowFit is the ability to resolve complex TL glow-curves consisting of strongly overlapping peaks, as those observed in heavily-doped LiF:Mg,Ti (MTT) detectors. This

M. Puchalska; P. Bilski

2006-01-01

30

Simulation of stationary glow patterns in dielectric barrier discharges at atmospheric pressure  

NASA Astrophysics Data System (ADS)

Self-organized stationary patterns in dielectric barrier discharges operating in glow regime at atmospheric pressure are investigated by a self-consistent two-dimensional fluid model. The simulation results show that two different modes, namely, the diffuse mode and the static patterned mode, can be formed in different ranges of the driving frequency. The discharge operates in Townsend regime in the diffuse mode, while it operates in a glow regime inside the filaments and in a Townsend regime outside the filaments in the stable pattered mode. The forming process of the stationary filaments can be divided into three stages, namely, destabilizing stage, self-assembling stage, and stable stage. The space charge associated with residual electron density and surface charge is responsible for the formation of these stationary glow patterns.

Liu, Fucheng; He, Yafeng; Dong, Lifang

2014-12-01

31

Electrical Features of Radio-frequency, Atmospheric-pressure, Bare-metallic-electrode Glow Discharges  

Microsoft Academic Search

Radio-frequency (RF), atmospheric-pressure glow discharge (APGD) plasmas with bare metallic electrodes have promising prospects\\u000a in the fields of plasma-aided etching, deposition, disinfection and sterilization, etc. In this paper, an induced gas discharge\\u000a approach is proposed for obtaining the RF, atmospheric-pressure, ?-mode, glow discharges with pure nitrogen or air as the\\u000a primary plasma-working gas using bare metallic electrodes. The discharge characteristics,

He-Ping Li; Wen-Ting Sun; Hua-Bo Wang; Guo Li; Cheng-Yu Bao

2007-01-01

32

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

33

Snails nu. Glow-Worms  

Microsoft Academic Search

SOME years ago I brought three glow-worms from Wales to London, and at night I put them on the grass, when all showed their lights ; but on looking for them a short time after, one had nearly disappeared, and on searching for it my hand came against something cold, and on taking it to the light I found it

R. S. Newall

1879-01-01

34

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

2012-01-01

35

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

36

Transition to the obstructed discharge and a sharp change in the voltage-current characteristic as a result of gas heating in a short (positive-column-free) high-pressure glow discharge  

NASA Astrophysics Data System (ADS)

The formation of a high-pressure glow discharge is studied under conditions when the discharge evolves from the normal glow to the abnormal glow. It is shown that the transition to the voltage-current characteristic of the obstructed discharge may take place as a result of heating the gas and a decrease in its density. The obstructed discharge follows the left-hand branch of the Paschen curve and features a sharp voltage rise and current density limitation.

Bogdanov, E. A.; Kudryavtsev, A. A.; Chirtsov, A. S.

2011-01-01

37

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

38

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

39

Glow Fast, Glow Slow: Alter the Rate of a Reaction!  

NSDL National Science Digital Library

Learners investigate one factor affecting reaction rates: temperature. In a darkened room, two identical lightsticks are placed in water -- one in hot water and one in cold water. The lightstick in the hot water glows brighter than the lightstick in the cold water since the light-producing reaction is faster in hot water. This activity, located on page 2 of the PDF, is one of three activities in the Take Home guide for the Chemical Reactions unit in OMSI's Chemistry Lab. Also included on the PDF are two additional activities: Cloudy Globs and Gas Production.

Oregon Museum of Science and Industry

1997-01-01

40

Glow Sticks: Spectra and Color Mixing  

ERIC Educational Resources Information Center

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. A black light can be used to…

Birriel, Jennifer; Birriel, Ignacio

2014-01-01

41

GLOWS: A High Fidelity Worm Simulator  

Microsoft Academic Search

This work presents our GLOWS (Gate- way Level Oregon Worm Simulator) simulator, de- signed to produce realistic worm traffic over a broad range of scenarios. GLOWS simulates the spread of a worm across the Internet and its propagation into a single domain with the goal of capturing the worm traffic that crosses the gateway point separating the monitored domain from

Shad Stafford; Jun Li; Toby Ehrenkranz; Paul Knickerbocker

42

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

43

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

44

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

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

Congenital Abnormalities  

MedlinePLUS

... Ask your pediatrician for a referral to a genetic counseling service . These services have expertise with a variety ... Family Health History & Genetics Detecting Genetic Abnormalities Prenatal Genetic Counseling Children with Down Syndrome: Health Care Information for ...

47

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

48

A large gap of radio frequency dielectric barrier atmospheric pressure glow discharge  

SciTech Connect

A large gap was acquired between electrodes (up to 5.5 mm) of Ar atmospheric pressure glow discharge in radio frequency dielectric barrier discharge (rf-DBD). The discharge of Ar plasma was characterized by I-V curve and Lissajous plot, and the effective power of the discharge was calculated based on the measured Lissajous plot and found to be higher than 90% of the input power. To gain a thorough understanding of the mechanism, the rf-DBD with a single dielectric barrier layer operating in gamma mode glow discharge of N{sub 2} plasma was diagnosed in spatial resolution through optical emission spectroscopy. It was concluded that secondary electron emission might be responsible for the sustainable glow discharge in the large gap rf-DBD plasma.

Li, B.; Chen, Q.; Liu, Z. W. [Laboratory of Plasma Physics and Materials, Beijing Institute of Graphic Communication, Beijing 102600 (China)

2010-01-25

49

Organosilicon thin film deposition in glow discharges  

SciTech Connect

Thin films have been deposited from hexamethyldisiloxane-oxygen fed radio-frequency glow discharges under the following conditions: O{sub 2}-to-HMDS ratio ranging from 0 to 20, fixed total flow rate of 15 sccm, 200 W input power, 100 mTorr pressure. The substrates are held at room temperature. The effect of oxygen-to-monomer ratio in the feed on both plasma species distribution and film chemical composition has been studied with a variety of diagnostics, i.e. Actinometric Optical Emission Spectroscopy, AOES, (plasma phase), Infrared Spectroscopy and Electron Spectroscopy for Chemical Analysis, ESCA, (surface). A mechanism of deposition is proposed, based on the role of Si-containing precursors and of SiO-containing ones, which accounts for the deposition rate and the film composition. The experimental apparatus consists of a stainless-steel parallel plate reactor with a 13.56 MHz rf power. Silicon substrates are positioned in the gap between the two electrodes on a grounded stainless-steel holder. Deposition rates have been evaluated, after each experiment, by means of gravimetric measurements. The optical emission from the discharges has been sampled through a quartz window and focused on the entrance slit of a 1 m focal length Jarrel-Ash monochromator. The relative concentration trends of Si, O, H, and C atoms and of SiO, OH, CH, and CO molecules in plasma phase, have been obtained by AOES as a function of feed composition, by utilizing Ar and He actinometers. ESCA analyses have been performed by means of a PHI 5300 Perkin Elmer spectrometer used in the fixed analyser transmission mode with pass ene of 35.75 eV.

d`Agostino, R.; Lamendola, R. [Universita di Bari (Italy)

1995-12-31

50

Sound wave propagation through glow discharge plasma  

NASA Astrophysics Data System (ADS)

This work investigates the use of glow discharge plasma for acoustic wave manipulation. The broader goal is the suppression of aerodynamic noise using atmospheric glow discharge plasma as a sound barrier. Part of the effort was devoted to the development of a system for the generation of a large volume stable DC glow discharge in air both at atmospheric and at reduced pressures. The single tone sound wave propagation through the plasma was systematically studied. Attenuation of the acoustic wave passing through the glow discharge was measured for a range of experimental conditions including different discharge currents, electrode configurations, air pressures and sound frequencies including audible sound and ultrasound. Sound attenuation by glow discharge plasma as high as -28 dB was recorded in the experiments. Two types of possible mechanisms were considered that can potentially cause the observed sound attenuation. One is a global mechanism and the other is a local mechanism. The global mechanism considered is based on the reflection and refraction of acoustic wave due to the gas temperature gradients that form around the plasma. The local mechanism, on the other hand, is essentially the interaction of the acoustic wave with the plasma as it propagates inside the discharge and it can be viewed as a feedback system. Detailed temperature measurements, using laser-induced Rayleigh scattering technique, were carried out in the glow discharge plasma in order to evaluate the role of global mechanism in the observed attenuation. These measurements were made for a range of conditions in the atmospheric glow discharge. Theoretical analysis of the sound attenuation was carried out to identify the physical mechanism for the observed sound attenuation by plasma. It was demonstrated that the global mechanism is the dominant mechanism of sound attenuation. As a result of this study, the potentials and limitations of the plasma noise suppression technology were determined and the feasibility of the approach for actual sound manipulation applications was demonstrated.

Stepaniuk, Vadim P.

51

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

52

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

53

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

54

Saddle-field glow-discharge deposition of amorphous semiconductors  

SciTech Connect

The authors present a dc saddle-field glow-discharge deposition procedure which combines the positive attributes of the conventional dc and rf glow-discharge techniques. Preliminary mass spectra analyses of both silane and methane glow-discharges demonstrates that ions constitute a significant fraction of the species reaching the film surface. Growth rate analyses suggest that ions play a significant role in the saddle-field glow-discharge deposition of amorphous semiconducting films.

Gaspari, F.; Sidhu, L.S.; O`Leary, S.K.; Zukotynski, S. [Univ. of Toronto, Ontario (Canada). Dept. of Electrical and Computer Engineering

1996-12-31

55

Electrical properties of pulsed glow discharge Two new aspects  

NASA Astrophysics Data System (ADS)

At the application of pulsed glow discharge (PGD) a transient power of several kW can be reached. This leads to a significant increase of the excitation and ionization efficiency of the sputtered sample atoms. Moreover, with pulsed mode temporally resolved optical emission spectrometry (OES) and mass spectrometry (MS) deliver additional information about the chemical bonds (Harrison 1998, Bengtson et al. 2000, Hang et al. 1996, Klingler et al. 1990, Lewis et al. 2001, Jackson and King 2003). However, the practical application of pulsed glow discharge (PGD) requires an understanding of the processes taking place in the pulsed system. There are some publications, where attention was paid on the voltage current characteristics and the current signal shape of PGD (King and Pan 1993, Lewis et al. 2003). Nevertheless more attention should be paid on the electrical properties of the PGD. In this work the shapes of current, voltage and emission intensity signals, obtained with two different pulse generators are compared. For better understanding of processes, taking place in the discharge the knowledge of the gas temperature is very important. Several authors have mentioned that heating of the cathode leads to changes of the voltage current curve, mainly a decrease of the current at the same voltage. This can be explained by a lower gas density at the same pressure but at higher temperatures (Chenlong et al. 1999, Tian and Chu 2001, Kasik et al. 2002). This phenomenon gives an approach to estimate the gas temperature of the plasma.

Efimova, V. V.; Voronov, M. V.; Hoffmann, V.; Eckert, J.

2008-07-01

56

Glow and pseudo-glow discharges in a surface discharge generator  

NASA Astrophysics Data System (ADS)

The glow discharge in flowing argon at one atmospheric pressure is realized in a surface discharge generator. The discharge current presents one peak per half-cycle of the applied voltage. The duration of the discharge pulse is more than 1?s when the frequency of the applied voltage is 60kHz. For the glow discharge in argon, the power consumption increases with the increase of voltage or the decrease of gas pressure. This relation is explained qualitatively based on the theory of the Townsend breakdown mechanism. In contrast, the discharge current in one atmospheric pressure air gives many spikes in each half-cycle and correspondingly this kind of discharge is called pseudo-glow discharge. Every current spike oscillates with high-frequency damping. The pseudo-glow discharge in one atmospheric pressure air might result from the streamer breakdown mechanism.

Li, Xue-Chen; Dong, Li-Fang; Wang, Long

2005-07-01

57

Study of atmospheric pressure glow discharge  

Microsoft Academic Search

Summary form only given. Atmospheric pressure glow discharges (APGD) in gases such as Helium, Argon and air were studied. APGD in Helium between two parallel plane electrodes covered with dielectric plates was simulated on the basis of one-dimensional fluid model and the parameters' distributions along the discharge channel were obtained. The development of an electron avalanche in one atmosphere air

Mingze Lu; Xinxin Wang; Yikang Pu; Zhicheng Guan

2002-01-01

58

Spark to glow discharge transition in cavities  

Microsoft Academic Search

The occurrence of spark, pseudoglow, and glow discharge in short gaps is discussed. The effect of gap spacing and overvoltage is examined in terms of both experimental observations and theoretical calculations. It is found that gaps or cavity diameters are more likely to undergo spark-type discharge, since the larger gas volume is more conductive to an uninterrupted exponential growth of

R. Bartnikas; J. P. Novak; Y. McNicoll

1990-01-01

59

Glow-worm and Thunderstorm; also Milk  

Microsoft Academic Search

IN the Daily News of July 14 is printed an observation by a Mr. Haswell, of Handsworth, which bears the marks of genuineness, that during a thunderstorm a glow-worm extinguished its light for a second or a second and a half before each flash, relighting at an equal interval after the flash. May I ask if this has been noticed

Oliver Lodge

1903-01-01

60

The Glow-worm in Scotland  

Microsoft Academic Search

MR. J. SHAW'S interesting note on the Glow-worm leads me to remark that it is common about Loch Lomond, and recalls the pleasant surprise with which I met one there, shining brilliantly by the wayside, so late as twelve o'clock on a dark midsummer's night.

Wm. McLaurin

1876-01-01

61

Mode transition in homogenous dielectric barrier discharge in argon at atmospheric pressure  

NASA Astrophysics Data System (ADS)

The influence of driving frequency on the discharge regime of a homogenous dielectric barrier discharge in argon at atmospheric pressure is studied through a one-dimensional self-consistent fluid model. The simulation results show that the discharge exhibits five notable discharge modes, namely the Townsend mode, stable glow mode, chaotic mode, asymmetric glow, and multiple period glow mode in a broad frequency range. The transition mechanisms of these modes should be attributed to the competition between the applied voltage and the memory voltage induced by the surface charges.

Liu, Fu-Cheng; He, Ya-Feng; Wang, Xiao-Fei

2014-07-01

62

Spatially resolved observation of a radio-frequency-powered glow discharge plasma for emission spectrometric analysis.  

PubMed

In glow discharge optical emission spectrometry, two-dimensional emission images for iron atomic lines were measured by using an imaging spectrograph equipped with a CCD detector, when a radio-frequency (r.f.) power source was employed for excitation. Emission images at the Fe I 371.99-nm and the Fe I 375.82-nm lines, having different excitation energies, were analyzed by the two-line method to obtain the spatial distribution of the excitation temperature in the plasma. Their emission intensities had a concentric-circle-like distribution along the radial direction of the plasma to become weaker towards the surrounding portion, which was very similar to a direct-current (d.c.) glow discharge plasma. On the other hand, the spatial distribution in the excitation temperature became relatively uniform over the central portion of the plasma, also being analogous between the r.f. and the d.c. glow discharge plasmas. These results imply that there is a major excitation process that occurs in a glow discharge plasma regardless of the power modes. PMID:23665634

Oka, Ryuichiro; Wagatsuma, Kazuaki

2013-01-01

63

Use of glow discharge in fluidized beds  

NASA Technical Reports Server (NTRS)

Static charges and agglomerization of particles in a fluidized bed systems are minimized by maintaining in at least part of the bed a radio frequency glow discharge. This approach is eminently suitable for processes in which the conventional charge removing agents, i.e., moisture or conductive particle coatings, cannot be used. The technique is applied here to the disproportionation of calcium peroxide diperoxyhydrate to yield calcium superoxide, an exceptionally water and heat sensitive reaction.

Wydeven, T.; Wood, P. C.; Ballou, E. V.; Spitze, L. A. (inventor)

1981-01-01

64

NASA CONNECT: 'Glow with the Flow'  

NASA Technical Reports Server (NTRS)

'Geometry and Algebra: Glow with the Flow' is the second of five programs in the 2000-2001 NASA CONNECT series. Produced by NASA Langley Research Center's Office of Education, NASA CONNECT is an award-winning series of instructional programs designed to enhance the teaching of math, science and technology in grades 5-8. NASA CONNECT establishes teh 'connection' between the mathematics, science, and tehcnology concepts taught in the classroom and NASA research. NASA CONNECT is FREE and the programs in the series are in the public domain. Visit our web site adn register http://connect.larc.nasa.gov In 'Geometry and Algebra: Glow with the Flow', students will learn about the force of drag and how NASA engineers use models and glowing paints to see how air flows over vehicles in a wind tunnel. Students will also discover how the blended wing body(BWB), a concept super jumbo jet that resembles a flying wing, will affect air travelers of the future. Students will observe NASA engineers using geometry and algebra when they measure and design models to be tested in wind tunnels. By conducting classroom and on-line activities, students will make connections between NASA research and the mathematics, science and technology they learn in their classroom.

1999-01-01

65

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

66

The one atmosphere uniform glow discharge plasma (OAUGDP) as a classical normal glow discharge  

Microsoft Academic Search

Summary form only given, as follows. The one atmosphere uniform glow discharge plasma (OAUGDP) operating in air and other gases, has been recently developed at the UTK Plasma Sciences Laboratory and is proprietary to the University of Tennessee. The plasma is driven at low RF frequency, on the order of a few kilohertz, and is formed in a relatively large

R. B. Gadri; D. M. Sherman; Zhiyu Chen; F. Karakaya; J. R. Roth

1999-01-01

67

Physical model of spherical glow discharge stratification  

NASA Astrophysics Data System (ADS)

A physical model of spherical glow discharge stratification is suggested where the striations represent the electric double layers, where opposite charges, initially separated in space due to fluctuations or ambipolar diffusion, are then stabilized by the specific conditions of the gas media with negative differential conductivity. These conditions appear and disappear during the discharge development owing to plasma-chemical reactions. The model has been tested using time-dependent mass-spectrometry, as well as numerical calculations of the electron transport coefficients for the observed composition.

Belikov, A. E.; Sakhapov, S. Z.

2011-02-01

68

Protein destruction by atmospheric pressure glow discharges  

NASA Astrophysics Data System (ADS)

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.

2007-01-01

69

The theory of positive glow corona  

NASA Astrophysics Data System (ADS)

A theory for the current and light pulses of positive glow corona from a point in air is presented; this phenomenon was first observed as an apparently continuous glow by Michael Faraday. Results are obtained, in concentric sphere geometry, for air at atmospheric pressure, by solving the continuity equations for electrons, positive ions, negative ions and metastable oxygen molecules, coupled with Poisson's equation. A series of `saw-toothed' current pulses of period about 0022-3727/30/22/008/img1 is predicted with a DC current level. Accompanying the current peaks are discrete pulses of light 30 ns wide. Successive `shells' of positive ions, from successive current pulses, carry 96% of the mean current. The mean current - voltage relationship has the classic square-law form. The seed electrons required for successive pulses are detached from negative ions by metastable oxygen molecules. Photo-ionization is crucial for the discharge at the anode and for the formation of negative ions throughout the gap. The pulse frequency varies with applied voltage and is found to be approximately proportional to the positive-ion mobility. The surface electric field at the central electrode remains close to Peek's onset field. The origin of onset streamers is explained and sub-microsecond voltage pulses are found to produce streamers. The results for concentric-cylinder electrodes are described briefly.

Morrow, R.

1997-11-01

70

Glow discharge based device for solving mazes  

SciTech Connect

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., E-mail: dubinov-ae@yandex.ru; Mironenko, Maxim S.; Selemir, Victor D. [Russian Federal Nuclear Center ? All-Russian Scientific and Research Institute of Experimental Physics (RFNC-VNIIEF), Sarov, Nizhni Novgorod region 607188 (Russian Federation); Sarov Institute of Physics and Technology (SarFTI) of National Research Nuclear University “MEPhI,” Sarov, Nizhni Novgorod region 607188 (Russian Federation); Maksimov, Artem N.; Pylayev, Nikolay A. [Russian Federal Nuclear Center ? All-Russian Scientific and Research Institute of Experimental Physics (RFNC-VNIIEF), Sarov, Nizhni Novgorod region 607188 (Russian Federation)

2014-09-15

71

Acting green elicits a literal warm glow  

NASA Astrophysics Data System (ADS)

Environmental policies are often based on the assumption that people only act environmentally friendly if some extrinsic reward is implicated, usually money. We argue that people might also be motivated by intrinsic rewards: doing the right thing (such as acting environmentally friendly) elicits psychological rewards in the form of positive feelings, a phenomenon known as warm glow. Given the fact that people's psychological state may affect their thermal state, we expected that this warm glow could express itself quite literally: people who act environmentally friendly may perceive the temperature to be higher. In two studies, we found that people who learned they acted environmentally friendly perceived a higher temperature than people who learned they acted environmentally unfriendly. The underlying psychological mechanism pertains to the self-concept: learning you acted environmentally friendly signals to yourself that you are a good person. Together, our studies show that acting environmentally friendly can be psychologically rewarding, suggesting that appealing to intrinsic rewards can be an alternative way to encourage pro-environmental actions.

Taufik, Danny; Bolderdijk, Jan Willem; Steg, Linda

2015-01-01

72

Diffuse ?-mode atmospheric pressure radio-frequency discharge in neon  

NASA Astrophysics Data System (ADS)

In this work, a radio-frequency (RF) atmospheric pressure glow discharge burning in neon between planar metal electrodes is achieved for the first time. The RF discharge can operate in two stable modes: in a diffuse ?-mode with uniformly covered electrode surfaces and in a constricted ?-mode. Similarities are revealed when the discharge is compared against the RF atmospheric pressure glow discharge in helium, namely both discharges show a discontinuity and a hysteresis in the current-voltage characteristic at the mode transition; the spatio-temporal profiles of the light emission in the ?-mode from neon, helium and atomic oxygen are also similar.

Navrátil, Z.; Dosoudilová, L.; Josepson, R.; Dvo?ák, P.; Trunec, D.

2014-08-01

73

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

74

The influence of transverse acoustic oscillations on contraction of the glow discharge  

NASA Astrophysics Data System (ADS)

The results of investigations of the interaction of longitudinal acoustic waves with electric gas discharge. Describes the phenomenon the formation of vortex flows in the acoustic gas discharge under the influence of a standing acoustic longitudinal waves. The phenomenon of occurrence vortex in the presence of transverse acoustic oscillations of the first tangential mode are analyzed. Presents the rationale of effective influence of the transverse acoustic oscillations on the glow discharge, which leads to the preservation of its diffuse form and, consequently, improve the energy input in the CO2-laser.

Fadeev, S. A.; Kashapov, N. F.

2013-12-01

75

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

76

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

77

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

78

Glowing Bacteria! Purpose: To use your knowledge about  

E-print Network

1 Glowing Bacteria! Purpose: To use your knowledge about genetic transformation to successfully fluorescent protein (GFP) was originally isolated from Aequora victoria, a bioluminescent jellyfish. The p, agar plates, ampicillin, arabinose Procedures: ALWAYS USE ASEPTIC TECHNIQUE WHEN HANDLING BACTERIA

Rose, Michael R.

79

Organic thin film deposition in atmospheric pressure glow discharge  

SciTech Connect

The stabilization of a homogeneous glow discharge at atmospheric pressure has been studied since 1987. On flat surfaces, various plasma surface treatments and film depositions at atmospheric pressure have been examined. A practical application of the atmospheric pressure glow plasma on inner surfaces of flexible polyvinyl chloride tubes was tested for thin film deposition of polytetrafluoroethylene. Deposited film surfaces were characterized by ESCA and FT-IR/ATR measurements. Also SEM observation was done for platelet adhesion on the plasma treated polyvinyl chloride surface. These results showed remarkable enhancement in the inhibition to platelet adhesion on the inner surface of PVC tube, and homogeneous organic film deposition was confirmed. The deposition mechanism of polytetrafluoroethylene film in atmospheric pressure glow plasma is the same as the mechanism of film formation in the low pressure glow plasma, except for radical formation source. {copyright} {ital 1996 American Institute of Physics.}

Okazaki, S.; Kogoma, M.; Yokoyama, T. [Sophia University, Kioi-cho 7-1, Chiyoda-ku, Tokyo 102 (Japan); Kodama, M. [Ministry of International Trade and Industry, Agency of Industrial Science and Technology, Higashi 1-1-4, Tsukuba-shi, Ibarki-k en 305 (Japan); Nomiyama, H.; Ichinohe, K. [Kawasumi Laboratories, Inc., Tamada 7-1, Miemachi, Ohno-gun, Ohita-ken 879-71 (Japan)

1996-01-01

80

Abnormal Head Position  

MedlinePLUS

... cause. Can a longstanding head turn lead to any permanent problems? Yes, a significant abnormal head posture could cause permanent ... occipitocervical synostosis and unilateral hearing loss. Are there any ... postures? Yes. Abnormal head postures can usually be improved depending ...

81

Thermoluminescence glow curve analysis of natural onyx from Turkey.  

PubMed

In this study, the thermoluminesce (TL) properties of natural onyx were determined after ?-irradiation ((9)(0)Sr/(90)Y) at room temperature. The effect of the additive dose and variable heating rate for TL glow peaks of the sample were investigated. Computerized glow curve deconvolution (CGCD) methods were used to determine the number of peaks and kinetic parameters related to the TL glow peaks in natural onyx from Turkey. It was also determined kinetic parameters of onyx by means of the variable heating rate (VHR) method. The sample was exposed to ?-irradiation between 2.4Gy and 2.457kGy. The CGCD methods showed that the glow curve of sample is the superposition of at least six first order components which were ascribed as P1-P6. The dose responses of some peaks have similar patterns and they follow linearity. The effect of heating rates on the response of dosimetric glow peaks of sample was studied. The maximum TL peak intensities of glow curve are decreasing with increasing heating rate and maximum TL peak intensities at 1°C/s drops to 20% of the initial value when the sample is read at 6°C/s. PMID:25474767

Dogan, Tamer; Toktam??, Hüseyin; Yüksel, Mehmet; Topaksu, Mustafa; Necmeddin Yazici, A

2015-02-01

82

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

83

Lunar horizon glow and the Clementine mission  

NASA Technical Reports Server (NTRS)

The Clementine spacecraft is to be launched into Earth orbit in late January for subsequent insertion into lunar orbit in late February, 1994. There, its primary mission is to produce -- over a period of about two months -- a new photographic map of the entire surface of the Moon; this will be done, in a variety of wavelengths and spatial resolutions, in a manner greatly superior to that previously accomplished for the whole Moon. It will then go on to fly by and photograph the asteroid Geographos. A secondary goal that has been accepted for this mission is to take a series of photographs designed to capture images of, and determine the brightness and extent of, the Lunar Horizon Glow (LHG). One form of LHG is caused by the solar stimulation of emission from Na and K atoms in the lunar exosphere. The scale height of this exosphere is of the order of 100 km. There are also brighter LHG components, with much smaller scale heights, that appear to be caused by scattered off of an exospheric lunar dust cloud.

Zook, H. A.; Potter, A. E.

1994-01-01

84

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

85

Research Into Characteristics of X-Ray Emission Laser Beams from Solid-State Cathode Medium of High-Current Glow Discharge  

NASA Astrophysics Data System (ADS)

X-ray emissions ranging 1.2-3.0 keV with dose rate up to 1.0 Gy/s have been registered in experiments with high-current Glow Discharge. The emissions energy and intensity depend on the cathode material, the kind of plasma-forming gas, and the discharge parameters. The experiments were carried out on the high-current glow discharge device using D2, H2, Kr, and Xe at pressure up to 10 Torr, as well as cathode samples made from Al, Sc, Ti, Ni, Nb, Zr, Mo, Pd, Ta, W, Pt, at current up to 500 mA, and discharge voltage of 500-2500 V. Two emission modes were revealed under the experiments: (1) Diffusion X-rays was observed as separate X-ray bursts (up to 5 × 105 bursts a second and up to 106 X-ray quanta in a burst), (2) X-rays in the form of laser microbeams (up to 104 beams a second and up to 1010 X-ray of quanta in a beam, angular divergence was up to 10-4, the duration of the separate laser beams must be ? = 3 × 10-13-3 × 10-14 s, the separate beam power must be 107-108 W). The emission of the X-ray laser beams occurred when the discharge occurred and within 100 ms after turning off the current. The results of experimental research into the characteristics of secondary penetrating radiation occurring when interacting primary X-ray beams from a solid-state cathode medium with targets made of various materials are reported. It was shown that the secondary radiation consisted of fast electrons. Secondary radiation of two types was observed: (1) The emission with a continuous temporal spectrum in the form of separate bursts with intensity up to 106 fast electrons a burst. (2) The emission with a discrete temporal spectrum and emission rate up to 1010 fast electrons a burst. A third type of the penetrating radiation was observed as well. This type was recorded directly by the photomultiplier placed behind of the target without the scintillator. The abnormal high penetrating ability of this radiation type requires additional research to explain. The obtained results show that creating optically active medium with long-living metastable levels with the energy of 1.0-3.0 keV and more is possible in the solid state.

Karabut, Alexander B.

2006-02-01

86

Active Noise Control Using Glow Discharge Plasma Panels Christopher Ali Merchant  

E-print Network

Active Noise Control Using Glow Discharge Plasma Panels by Christopher Ali Merchant B Using Glow Discharge Plasma Panels by Christopher Ali Merchant Submitted to the Department of the payload fairing cavity. Structural control techniques, using piezoelectric actuators, have previously been

87

Evidence of Low Dimensional Chaos in Glow Curves of Thermoluminescence  

E-print Network

Electron trapping following exposition to ionising radiations and consequent electron release during variation of temperature in solids represent processes happening at the quantum microphysical level. The interesting feature of the thermally stimulated process, that in fact deserves further investigation, is that the dynamic of electrons release during, variation of the temperature, here examined through the so called thermoluminescent Glow Curve, evidences chaotic and fractal regimes. Phase space reconstruction, Correlation Dimension, largest Lyapunov exponent, Recurrence Quantification Analysis(RQA) and fractal dimension analysis, developed by calculation of Hurst exponent, are performed on three samples. The results unequivocally fix that Glow Curves respond to a chaotic regime. RQA supports such results revealing the inner structure of Glow Curve signals in relation to their properties of recurrence, determinism and intermittency signed from laminarity as well as chaos-chaos and chaos order transitions.

Conte, Elio

2008-01-01

88

Evidence of Low Dimensional Chaos in Glow Curves of Thermoluminescence  

E-print Network

Electron trapping following exposition to ionising radiations and consequent electron release during variation of temperature in solids represent processes happening at the quantum microphysical level. The interesting feature of the thermally stimulated process, that in fact deserves further investigation, is that the dynamic of electrons release during, variation of the temperature, here examined through the so called thermoluminescent Glow Curve, evidences chaotic and fractal regimes. Phase space reconstruction, Correlation Dimension, largest Lyapunov exponent, Recurrence Quantification Analysis(RQA) and fractal dimension analysis, developed by calculation of Hurst exponent, are performed on three samples. The results unequivocally fix that Glow Curves respond to a chaotic regime. RQA supports such results revealing the inner structure of Glow Curve signals in relation to their properties of recurrence, determinism and intermittency signed from laminarity as well as chaos-chaos and chaos order transitions.

Elio Conte; Joseph P. Zbilut

2008-12-04

89

Investigation of helium ion production in constricted direct current plasma ion source with layered-glows  

SciTech Connect

Generation of helium ions is experimentally investigated with a constricted direct current (DC) plasma ion source operated at layered-glow mode, in which electrons could be accelerated through multiple potential structures so as to generate helium ions including He{sup 2+} by successive ionization collisions in front of an extraction aperture. The helium discharge is sustained with the formation of a couple of stable layers and the plasma ball with high density is created near the extraction aperture at the operational pressure down to 0.6 Torr with concave cathodes. The ion beam current extracted with an extraction voltage of 5 kV is observed to be proportional to the discharge current and inversely proportional to the operating pressure, showing high current density of 130 mA/cm{sup 2} and power density of 0.52 mA/cm{sup 2}/W. He{sup 2+} ions, which were predicted to be able to exist due to multiple-layer potential structure, are not observed. Simple calculation on production of He{sup 2+} ions inside the plasma ball reveals that reduced operating pressure and increased cathode area will help to generate He{sup 2+} ions with the layered-glow DC discharge.

Lee, Yuna [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Park, Yeong-Shin [Samsumg Electronics Co. Ltd., Gyeonggi 445-701 (Korea, Republic of)] [Samsumg Electronics Co. Ltd., Gyeonggi 445-701 (Korea, Republic of); Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of) [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2014-02-15

90

Investigation of helium ion production in constricted direct current plasma ion source with layered-glows.  

PubMed

Generation of helium ions is experimentally investigated with a constricted direct current (DC) plasma ion source operated at layered-glow mode, in which electrons could be accelerated through multiple potential structures so as to generate helium ions including He(2+) by successive ionization collisions in front of an extraction aperture. The helium discharge is sustained with the formation of a couple of stable layers and the plasma ball with high density is created near the extraction aperture at the operational pressure down to 0.6 Torr with concave cathodes. The ion beam current extracted with an extraction voltage of 5 kV is observed to be proportional to the discharge current and inversely proportional to the operating pressure, showing high current density of 130 mA/cm(2) and power density of 0.52 mA/cm(2)/W. He(2+) ions, which were predicted to be able to exist due to multiple-layer potential structure, are not observed. Simple calculation on production of He(2+) ions inside the plasma ball reveals that reduced operating pressure and increased cathode area will help to generate He(2+) ions with the layered-glow DC discharge. PMID:24593635

Lee, Yuna; Chung, Kyoung-Jae; Park, Yeong-Shin; Hwang, Y S

2014-02-01

91

Influences of impedance matching network on pulse-modulated radio frequency atmospheric pressure glow discharges  

SciTech Connect

Pulse-modulated RF atmospheric pressure glow discharges (APDGs) were investigated in recent years to reduce the thermal accumulation and extend the operation region of the stable alpha glow mode. Different pulse-modulated voltage and current waveforms were acquired in previous experiments, but no attention was paid to the interpretation. We investigated this issue and associated phenomenon via positive and negative feedback effects derived from varying the series capacitor in the inversely L-shaped matching network used in our pulse-modulated RF APGD source. The evolutions of pulse-modulated RF waveforms were found to be associated with the feedback region and the pulsed plasma absorbed RF power. In the positive feedback region, pulse-modulated RF APGDs are relatively stable. In the negative feedback region, wide spikes as well as undershoots occur in RF voltage and current waveforms and the plasma absorbed RF power. In case of a high RF power discharge with a low modulation frequency, the pulse-modulated RF APGD is extinguished and re-ignited due to the enhanced undershoot during the initial pulse phase. The pulse-modulated RF APGD can transit from positive to negative feedback region in a range of series capacitance. Experimental results are discussed by the aid of equivalent circuit, negative and positive feedback effects.

Huo, W. G. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029 (China); Xu, K.; Sun, B.; Ding, Z. F. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China)

2012-08-15

92

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

93

Structurally abnormal human autosomes  

SciTech Connect

Chapter 25, discusses structurally abnormal human autosomes. This discussion includes: structurally abnormal chromosomes, chromosomal polymorphisms, pericentric inversions, paracentric inversions, deletions or partial monosomies, cri du chat (cat cry) syndrome, ring chromosomes, insertions, duplication or pure partial trisomy and mosaicism. 71 refs., 8 figs.

NONE

1993-12-31

94

Dynamics of pulse phenomena in helium dielectric-barrier atmospheric-pressure glow discharges  

E-print Network

Dynamics of pulse phenomena in helium dielectric-barrier atmospheric-pressure glow discharges of pulse phenomena in conventional parallel-plate dielectric-barrier controlled atmospheric-pressure glow. DOI: 10.1063/1.1625414 I. INTRODUCTION There is rapidly growing interest in atmospheric- pressure glow

Raja, Laxminarayan L.

95

Role of trace impurities in large-volume noble gas atmospheric-pressure glow discharges  

E-print Network

Role of trace impurities in large-volume noble gas atmospheric-pressure glow discharges Xiaohui 2002 A computational study of capacitively coupled atmospheric-pressure glow discharges in high atmospheric-pressure glow discharges. © 2002 American Institute of Physics. DOI: 10.1063/1.1497445 Several

Raja, Laxminarayan L.

96

Glow discharge detector for terahertz and millimeter wave radiation detection and imaging  

Microsoft Academic Search

Glow discharge plasma, deriving from direct current gas breakdown, was investigated in order to realize an inexpensive THz room temperature detector. Preliminary results for THz radiation show that glow discharge indicator lamps as room temperature detectors yield good responsivity and NEP. Development of a Focal Plane Array (FPA) using such devices as detectors is advantageous since the costs of glow

A. Abromovich; N. S. Kopeika; D. Rozban

2007-01-01

97

GLOWS: A High Fidelity Worm Simulator Shad Stafford, Jun Li, Toby Ehrenkranz, and Paul Knickerbocker  

E-print Network

1 GLOWS: A High Fidelity Worm Simulator Shad Stafford, Jun Li, Toby Ehrenkranz, and Paul}@cs.uoregon.edu Abstract--This work presents our GLOWS (Gate- way Level Oregon Worm Simulator) simulator, de- signed to produce realistic worm traffic over a broad range of scenarios. GLOWS simulates the spread of a worm

Li, Jun

98

Morphological abnormalities among lampreys  

USGS Publications Warehouse

The experimental control of the sea lamprey (Petromyzon marinus) in the Great Lakes has required the collection of thousands of lampreys. Representatives of each life stage of the four species of the Lake Superior basin were examined for structural abnormalities. The most common aberration was the presence of additional tails. The accessory tails were always postanal and smaller than the normal tail. The point of origin varied; the extra tails occurred on dorsal, ventral, or lateral surfaces. Some of the extra tails were misshaped and curled, but others were normal in shape and pigment pattern. Other abnormalities in larval sea lampreys were malformed or twisted tails and bodies. The cause of the structural abnormalities is unknown. The presence of extra caudal fins could be genetically controlled, or be due to partial amputation or injury followed by abnormal regeneration. Few if any lampreys with structural abnormalities live to sexual maturity.

Manion, Patrick J.

1967-01-01

99

Glow discharge detector for terahertz and millimeter wave radiation detection and imaging  

NASA Astrophysics Data System (ADS)

Glow discharge plasma, deriving from direct current gas breakdown, was investigated in order to realize an inexpensive THz room temperature detector. Preliminary results for THz radiation show that glow discharge indicator lamps as room temperature detectors yield good responsivity and NEP. Development of a Focal Plane Array (FPA) using such devices as detectors is advantageous since the costs of glow discharge detector is around 0.2-0.5 per lamp, and the FPA images will be diffraction limited. The detection mechanism of the glow discharge detector was found to be enhanced diffusion current which causes decrease of glow discharge detector bias current when exposed to THz radiation.

Abromovich, A.; Kopeika, N. S.; Rozban, D.

2007-10-01

100

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

101

Degradation of Organics in a Glow Discharge Under Martian Conditions  

NASA Technical Reports Server (NTRS)

The primary objective of this project is to understand the consequences of glow electrical discharges on the chemistry and biology of Mars. The possibility was raised some time ago that the absence of organic material and carbonaceous matter in the Martian soil samples studied by the VikinG Landers might be due in part to an intrinsic atmospheric mechanism such as glow discharge. The high probability for dust interactions during Martian dust storms and dust devils, combined with the cold, dry climate of Mars most likely results in airborne dust that is highly charged. Such high electrostatic potentials generated during dust storms on Earth are not permitted in the low-pressure CO2 environment on Mars; therefore electrostatic energy released in the form of glow discharges is a highly likely phenomenon. Since glow discharge methods are used for cleaning and sterilizing surfaces throughout industry, the idea that dust in the Martian atmosphere undergoes a cleaning action many times over geologic time scales appears to be a plausible one.

Hintze, P. E.; Calle, L. M.; Calle, C. I.; Buhler, C. R.; Trigwell, S.; Starnes, J. W.; Schuerger, A. C.

2006-01-01

102

Thin Film Adhesion: Effect of Glow Discharge on Substrate  

Microsoft Academic Search

Glow discharge treatment of soda lime glass and silica substrates prior to depositing copper films in oil-free ultra high vacuum as well as in conventional vacuum has been found to increase film adhesion suggesting that gross contamination removal is not the only effect of importance in this method of improving film adhesion. There is evidence from Auger electron emission spectroscopy

C. T. H. Stoddart; D. R. Clarke; C. J. Robbie

1970-01-01

103

Immobilization of proteins on glow discharge treated polymers  

NASA Astrophysics Data System (ADS)

Certain glow discharge-treated surfaces have been shown to enhance retention of adsorbed proteins. On the basis of this phenomenon, we have investigated the possibility of immobilizing (a) albumin for developing thromboresistant and non-fouling surfaces, (b) antibodies for immuno-diagnostic assays and (c) enzymes for various biosensors and industrial bioprocesses. Albumin retention was highest on surfaces treated with tetrafluoroethylene (TFE) compared to untreated surfaces or other glow discharge treatments studied. Preadsorption of albumin on TFE-treated surfaces resulted in low fibrinogen adsorption and platelet adhesion. IgG retention was also highest on TFE-treated surfaces. The lower detection limits of both malaria antigen and circulating anodic antigen of the schistosomiasis worm were enhanced following glow discharge treatment of the assay plates with TFE. Both TFE and tetrachloroethylene (TCE) glow discharge treated surfaces showed high retention of adsorbed horseradish peroxidase (HRP). However, the retained specific activity of HRP after adsorption on TCE-treated surfaces was remarkably higher than on TFE-treated surfaces.

Kiaei, D.; Safranj, A.; Chen, J. P.; Johnston, A. B.; Zavala, F.; Deelder, A.; Castelino, J. B.; Markovic, V.; Hoffman, A. S.

104

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

105

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

NASA Astrophysics Data System (ADS)

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 ?-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, Wen-Ting; Li, Guo; Li, He-Ping; Bao, Cheng-Yu; Wang, Hua-Bo; Zeng, Shi; Gao, Xing; Luo, Hui-Ying

2007-06-01

106

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

107

"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

108

Abnormal Uterine Bleeding  

MedlinePLUS

... as cancer of the uterus, cervix, or vagina • Polycystic ovary syndrome How is abnormal bleeding diagnosed? Your health care ... before the fetus can survive outside the uterus. Polycystic Ovary Syndrome: A condition characterized by two of the following ...

109

Tooth - abnormal colors  

MedlinePLUS

... age when teeth are forming Poor oral care Porphyria Severe neonatal jaundice Too much fluoride from environmental ... abnormal coloration began Foods you have been eating Medications you are taking Personal and family health history ...

110

The back-diffusion effect of air on the discharge characteristics of atmospheric-pressure radio-frequency glow discharges using bare metal electrodes  

Microsoft Academic Search

Radio-frequency (RF), atmospheric-pressure glow discharge (APGD) plasmas using bare metal electrodes have promising prospects in the fields of plasma-aided etching, deposition, surface treatment, disinfection, sterilization, etc. In this paper, the discharge characteristics, including the breakdown voltage and the discharge voltage for sustaining a stable and uniform alpha mode discharge of the RF APGD plasmas are presented. The experiments are conducted

Wen-Ting Sun; Tian-Ran Liang; Hua-Bo Wang; He-Ping Li; Cheng-Yu Bao

2007-01-01

111

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

112

San Diego Natural History Museum: Glow: Living Lights  

NSDL National Science Digital Library

The San Diego Natural History Museum (SDNHM) has recently added a downloadable Teacher's Guide to its Web site for Glow: Living Lights -- "the first-ever museum exhibition to explore the phenomenon of bioluminescence." The 48-page Teacher's Guide is loaded with great lesson plans for grades 3-6. The activities may be used without a visit to the actual exhibit, although the Teacher's Guide also includes useful material for those lucky enough to make the trip. Glow: Living Lights "is an excellent platform for a number of scientific disciplines, including chemistry, biology, ecology, and oceanography." In addition to the Teacher's Guide, this Web site provides a fun, general guide to bioluminescence geared toward kids, which includes games, quick facts, a glossary, and related Web links.

113

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

114

Novel plasma polymerized films under dc glow discharge  

SciTech Connect

It has been reported that various dielectric films can be readily prepared by plasma polymerization, but these films have been made using AC glow discharge at a specific frequency (such as RF). in this paper, we examined the plasma polymerization of non-fluorinated and fluorinated aromatic hydrocarbons using a new plasma polymerization system that used DC glow discharge. Features of this DC system are; (1) polymerization proceeds under an isotropic electric field, (2) density of cations around the substrate on the cathode is high, (3) the polymer that accumulates during the initial stage is exposed to the DC discharge for a long period of time, (4) depth profile of the polymer films is isotropic, especially when polar monomers are used. The results of ESCA of plasma polymerized films indicated that the content of fluorine in the polymer films was isotropic with the film depth. Dielectric properties of the films were also examined.

Kakimoto, Masa-aki; Suwa, Toshihiro; Imai, Yoshio [Tokyo Institute of Technology (Japan)

1995-12-01

115

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

116

Sterilization of medical productsin low-pressure glow discharges  

Microsoft Academic Search

Results are presented from experimental and theoretical studies of the sterilization of medical products by the plasmas of\\u000a dc glow discharges in different gas media. The sterilization efficiency is obtained as a function of discharge parameters.\\u000a The plasma composition in discharges in N2 and O2 is investigated under the operating conditions of a plasma sterilizer. It is shown that free

I. A. Soloshenko; V. V. Tsiolko; V. A. Khomich; A. I. Shchedrin; A. V. Ryabtsev; V. Yu. Bazhenov; I. L. Mikhno

2000-01-01

117

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

118

Imaging of atmospheric pressure glow discharges in helium and argon  

Microsoft Academic Search

We present images of atmospheric pressure glow discharges (APGD) in pure noble gases, helium and argon, for a needle-plane (N-P) electrode geometry. The images have been obtained using an intensified charge-coupled device (ICCD) digital camera, at nanosecond exposure times. We present time-dependence of discharge images perpendicular and parallel to the interelectrode gap for both helium and argon.

I. Radu; R. Bartnikas; M. R. Wertheimer

2005-01-01

119

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

120

Electron concentration distribution in a glow discharge in air flow  

NASA Astrophysics Data System (ADS)

Electron concentration distributions in a glow discharge in longitudinal and vortex air flows are determined from the attenuation of the electromagnetic wave passing through the plasma using microwave probes. An analysis of the distribution curves obtained indicates that electron concentration decreases in the direction of the anode. This can be explained by charge diffusion toward the chamber walls and electron recombination and sticking within the discharge.

Mukhamedzianov, R. B.; Gaisin, F. M.; Sabitov, R. A.

1989-04-01

121

Plasma sterilization using glow discharge at atmospheric pressure  

Microsoft Academic Search

Recent development of atmospheric pressure glow discharge was compared with the performance of an apparatus used in the first APG experiment, in terms of sterilization of newly classified biological indicator: Bacillus atrophaeus, former Bacillus subtilis var. niger and Geobacillus stearothermophilus. Stabilization was attained by controlling the experimental conditions, at low frequency: 100 kHz and Radio Frequency: 13.56 MHz, water vapor\\/He

Tetsuya Akitsu; Hiroshi Ohkawa; Masao Tsuji; Hideo Kimura; Masuhiro Kogoma

2005-01-01

122

Effect of glow discharge air plasma on grain crops seed  

SciTech Connect

Oat and barley seeds have been exposed to both continuous and pulsed glow discharge plasmas in air to investigate the effects on germination and sprout growth. Statistical analysis was used to evaluate the effect of plasma exposure on the percentage germination and length of sprout growth. A stimulating effect of plasma exposure was found together with a strong dependence on whether continuous or pulsed discharges were used.

Dubinov, A.E.; Lazarenko, E.M.; Selemir, V.D.

2000-02-01

123

[Study on magnesium ionization in cathodic sputtering glow discharge plasma].  

PubMed

A method, based on the Doppler broadening-dependent absorption width and the ionization degree measured by the ratio of relative atomic and ionic absorbance in cathodic sputtering glow discharge (CSGD) plasma with aluminum-magnesium alloys as cathodes, is proposed. The experimental reveals that the plentiful magnesium ions in the plasma under the conventional discharge conditions of the atomizer do influence the analytic working curves. Corrected method is derived and factors which result in magnesium ionization degree are disscused. PMID:15822315

You, J; Wang, Z; Zhang, G; Ren, J; Jiang, G

1999-12-01

124

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.

125

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

126

Abnormal Psychology Psychology 280  

E-print Network

1 Abnormal Psychology Psychology 280 1st Summer Session 2013 May 13June 27, 2013 Tuesday" Kalibatseva, M.A. Office: 127B Psychology Building Email: kalibats@msu.edu Phone Psychology PhD program at Michigan State University. I completed my bachelor's dual degree in psychology

Liu, Taosheng

127

Simulation of Atmospheric Pressure Direct Current Glow Discharge along a Miniature Helium Flow in Nitrogen  

NASA Astrophysics Data System (ADS)

In this work, we carried out two-dimensional numerical simulation of atmospheric pressure dc glow discharge with miniature helium flow in nitrogen. The glow discharge is generated along the helium flow, which is injected from the nozzle anode into the discharge region filled with nitrogen. The purpose of this study is to clarify the relationship between the glow discharge structure and the helium flow. We found that the glow discharge generation is limited in the region with a very high helium mole fraction. Therefore, the helium mole fraction is an important parameter to determine the discharge structure along the helium flow.

Tochikubo, Fumiyoshi; Shirai, Naoki; Uchida, Satoshi

2011-05-01

128

Abnormal pressures as hydrodynamic phenomena  

USGS Publications Warehouse

So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

Neuzil, C.E.

1995-01-01

129

Thalassemia and abnormal hemoglobin  

Microsoft Academic Search

Thalassemia and abnormal hemoglobins are common genetic disorders in Asia. Thalassemia is not only an important public health\\u000a problem but also a socio-economic problem of many countries in the region. The approach to deal with the thalassemic problem\\u000a is to prevent and control birth of new cases. This requires an accurate identification of the couple at high risk for thalassemia.

Suthat Fucharoen; Pranee Winichagoon

2002-01-01

130

Anatomical Abnormalities in Autism?  

PubMed

Substantial controversy exists regarding the presence and significance of anatomical abnormalities in autism spectrum disorders (ASD). The release of the Autism Brain Imaging Data Exchange (?1000 participants, age 6-65 years) offers an unprecedented opportunity to conduct large-scale comparisons of anatomical MRI scans across groups and to resolve many of the outstanding questions. Comprehensive univariate analyses using volumetric, thickness, and surface area measures of over 180 anatomically defined brain areas, revealed significantly larger ventricular volumes, smaller corpus callosum volume (central segment only), and several cortical areas with increased thickness in the ASD group. Previously reported anatomical abnormalities in ASD including larger intracranial volumes, smaller cerebellar volumes, and larger amygdala volumes were not substantiated by the current study. In addition, multivariate classification analyses yielded modest decoding accuracies of individuals' group identity (<60%), suggesting that the examined anatomical measures are of limited diagnostic utility for ASD. While anatomical abnormalities may be present in distinct subgroups of ASD individuals, the current findings show that many previously reported anatomical measures are likely to be of low clinical and scientific significance for understanding ASD neuropathology as a whole in individuals 6-35 years old. PMID:25316335

Haar, Shlomi; Berman, Sigal; Behrmann, Marlene; Dinstein, Ilan

2014-10-14

131

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

132

Exercises to Improve Gait Abnormalities  

MedlinePLUS

... Home About Goals Articles Directories Videos Resources Contact Exercises to Improve Gait Abnormalities Home » Article Categories » Exercise and Fitness Font Size: A A A A Exercises to Improve Gait Abnormalities Next Page The manner ...

133

Abnormal human sex chromosome constitutions  

SciTech Connect

Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

NONE

1993-12-31

134

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

135

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

136

Persistence of phosphor glow in microchannel plate image intensifiers  

NASA Technical Reports Server (NTRS)

Image intensifier tubes using microchannel plate amplification stages and phosphor output stages are being increasingly used in various detection applications. In this paper, measurements of the decay times of what are attributed to be the P20 phosphors in various image intensifiers are reported. It is found that the long tail on the decay curve of the phosphor following illumination can be a limitation for certain observations. In addition, the background level of phosphor glow (which is seen by the subsequent detection system as a light signal) continues to build with continuing illumination.

Torr, M. R.

1985-01-01

137

LANL Transfers Glowing Bio Technology to Sandia Biotech  

SciTech Connect

Partnering with Los Alamos National Laboratory, an Albuquerque-based company is seeking to transform the way protein and peptide analysis is conducted around the world. Sandia Biotech is using a biological technology licensed from Los Alamos called split green fluorescent protein (sGFP), as a detecting and tracking tool for the protein and peptide industry, valuable in the fields of Alzheimer's research, drug development and other biotechnology fields using protein folding to understand protein expression and mechanisms of action. http://www.lanl.gov/news/stories/glowing-future-for-los-alamos-and-sandia-b iotech-partnership.html

Rorick, Kevin

2012-01-01

138

LANL Transfers Glowing Bio Technology to Sandia Biotech  

ScienceCinema

Partnering with Los Alamos National Laboratory, an Albuquerque-based company is seeking to transform the way protein and peptide analysis is conducted around the world. Sandia Biotech is using a biological technology licensed from Los Alamos called split green fluorescent protein (sGFP), as a detecting and tracking tool for the protein and peptide industry, valuable in the fields of Alzheimer's research, drug development and other biotechnology fields using protein folding to understand protein expression and mechanisms of action. http://www.lanl.gov/news/stories/glowing-future-for-los-alamos-and-sandia-b iotech-partnership.html

Rorick, Kevin

2012-08-02

139

Prenatal screening for chromosome abnormalities  

Microsoft Academic Search

An abnormal chromosome complement (aneuploidy) contributes significantly to fetal loss during pregnancy, as well as to perinatal morbidity and mortality. The contribution of chromosomal abnormalities to fetal loss decreases as pregnancy continues with an estimated 50% of first trimester spontaneous abortions due to chromosomal abnormalities, but only 5% of stillbirths (after 28 weeks). Prenatal screening for aneuploidy (in particular Down

Lyn Chitty

140

LOX/Methane Main Engine Glow Plug Igniter Tests and Modeling  

NASA Technical Reports Server (NTRS)

Ignition data for tests with a LOX/methane igniter that utilized a glow plug as the ignition source are presented. The tests were conducted in a vacuum can with thermally conditioned (cold) hardware. Data showing the effects of glow plug geometry, type, and igniter operating conditions are discussed. Comparisons between experimental results and multidimensional, transient computer models are also made.

Breisacher, Kevin; Ajmani, Kumud

2009-01-01

141

Glow experiment documentation of OMS/RCS pods and vertical stabilizer  

NASA Technical Reports Server (NTRS)

Glow experiment documentation of orbital maneuvering system (OMS) reaction control system (RCS) pods and vertical stabilizer shows chemoluminescent effect resulting from atomic oxygen impacting the spacecraft and building to the point that the atomic oxygen atoms combine to form molecules of oxygen. Image intensifier on NIKON 35mm camera used to record glow on vertical tail and OMS pods.

1982-01-01

142

Glow experiment documentation of OMS/RCS pods and vertical stabilizer  

NASA Technical Reports Server (NTRS)

Glow experiment documentation of orbital maneuvering system (OMS) reaction control system (RCS) pods and vertical stabilizer shows chemo-luminescent effect resulting from atomic oxygen impacting the spacecraft and building to the point that the atomic oxygen atoms combine to form molecules of oxygen. Image intensifier on NIKON 35mm camera was used to record glow on vertical tail and OMS pods.

1982-01-01

143

Glow experiment documentation of OMS/RCS pod and vertical stabilizer  

NASA Technical Reports Server (NTRS)

Glow experiment documentation of one of the orbital maneuvering system (OMS) reaction control system (RCS) pods and a portion of the vertical stabilizer shows chemoluminescent effectresulting from atomic oxygen impacting the spacecraft and building to the point that the atomic oxygen atoms combine to form molecules of oxygen. The Image Intensifier on NIKON 35mm camera was used to record the glow.

1982-01-01

144

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

E-print Network

The analysis of thermoluminescent glow peaks of CaF 2 : Dy (TLD-200) after -irradiation of thermoluminescent glow peaks of CaF2 : Dy (TLD-200) after -irradiation A Necmeddin Yazici1,4 , Reuven Chen2 , Semra : Dy, LiF : Mg : Ti(TLD-100) and some other thermoluminescent materials, relatively little work has

Chen, Reuven

145

Method of inducing differential etch rates in glow discharge produced amorphous silicon  

DOEpatents

A method of inducing differential etch rates in glow discharge produced amorphous silicon by heating a portion of the glow discharge produced amorphous silicon to a temperature of about 365.degree. C. higher than the deposition temperature prior to etching. The etch rate of the exposed amorphous silicon is less than the unheated amorphous silicon.

Staebler, David L. (Lawrenceville, NJ); Zanzucchi, Peter J. (Lawrenceville, NJ)

1980-01-01

146

Glow-worm larvae bioluminescence (Coleoptera: Lampyridae) operates as an aposematic signal upon toads (Bufo bufo)  

Microsoft Academic Search

It is an established fact that the spectacular bioluminescent displays of adult fireflies and glow-worms are used as courtship signals; however, the survival value of the glowing behavior of their larvae remained the subject of speculation for many years. Our study is the first that demonstrates that lampyrid larvae use luminescence to signal unpalatability to nocturnal, visually guided predators. Wild-caught

Erik Matthysen

2003-01-01

147

Influence of driving frequency on discharge modes in a dielectric-barrier discharge with multiple current pulses  

SciTech Connect

A one-dimensional self-consistent fluid model was employed to investigate the effect of the driving frequency on the discharge modes in atmospheric-pressure argon discharge with multiple current pulses. The discharge mode was discussed in detail not only at current peaks but also between two adjacent peaks. The simulation results show that different transitions between the Townsend and glow modes during the discharge take place with the driving frequency increased. A complicated transition from the Townsend mode, through glow, Townsend, and glow, and finally back to the Townsend one is found in the discharge with the driving frequency of 8 kHz. There is a tendency of transition from the Townsend to glow mode for the discharge both at the current peaks and troughs with the increasing frequency. The discharge in the half period can all along operate in the glow mode with the driving frequency high enough. This is resulted from the preservation of more electrons in the gas gap and acquisition of more electron energy from the swiftly varying electric field with the increase in driving frequency. Comparison of the spatial and temporal evolutions of the electron density at different driving frequencies indicates that the increment of the driving frequency allows the plasma chemistry to be enhanced. This electrical characteristic is important for the applications, such as surface treatment and biomedical sterilization.

Jiang, Weiman; Tang, Jie; Wang, Yishan; Zhao, Wei [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics of CAS, Xi'an 710119 (China)] [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics of CAS, Xi'an 710119 (China); Duan, Yixiang [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics of CAS, Xi'an 710119 (China) [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics of CAS, Xi'an 710119 (China); Research Center of Analytical Instrumentation, Sichuan University, Chengdu 610064 (China)

2013-07-15

148

On electron bunching and stratification of glow discharges  

SciTech Connect

Plasma stratification and excitation of ionization waves is one of the fundamental problems in gas discharge physics. Significant progress in this field is associated with the name of Lev Tsendin. He advocated the need for the kinetic approach to this problem contrary to the traditional hydrodynamic approach, introduced the idea of electron bunching in spatially periodic electric fields, and developed a theory of kinetic resonances for analysis of moving striations in rare gases. The present paper shows how Tsendin's ideas have been further developed and applied for understanding the nature of the well-known S-, P-, and R-striations observed in glow discharges of inert gases at low pressures and currents. We review numerical solutions of a Fokker-Planck kinetic equation in spatially periodic electric fields under the effects of elastic and inelastic collisions of electrons with atoms. We illustrate the formation of kinetic resonances at specific field periods for different shapes of injected Electron Distribution Functions (EDF). Computer simulations illustrate how self-organization of the EDFs occurs under nonlocal conditions and how Gaussian-like peaks moving along resonance trajectories are formed in a certain range of discharge conditions. The calculated EDFs agree well with the experimentally measured EDFs for the S, P, and R striations in noble gases. We discuss how kinetic resonances affect dispersion characteristics of moving striations and mention some non-linear effects associated with glow discharge stratification. We propose further studies of stratification phenomena combining physical kinetics and non-linear physics.

Golubovskii, Yuri B. [St. Petersburg State University, St. Petersburg 198504 (Russian Federation)] [St. Petersburg State University, St. Petersburg 198504 (Russian Federation); Kolobov, Vladimir I. [CFD Research Corporation, Huntsville, Alabama 35805 (United States)] [CFD Research Corporation, Huntsville, Alabama 35805 (United States); Nekuchaev, Vladimir O. [Ukhta State Technical University, Ukhta 169300 (Russian Federation)] [Ukhta State Technical University, Ukhta 169300 (Russian Federation)

2013-10-15

149

On electron bunching and stratification of glow discharges  

NASA Astrophysics Data System (ADS)

Plasma stratification and excitation of ionization waves is one of the fundamental problems in gas discharge physics. Significant progress in this field is associated with the name of Lev Tsendin. He advocated the need for the kinetic approach to this problem contrary to the traditional hydrodynamic approach, introduced the idea of electron bunching in spatially periodic electric fields, and developed a theory of kinetic resonances for analysis of moving striations in rare gases. The present paper shows how Tsendin's ideas have been further developed and applied for understanding the nature of the well-known S-, P-, and R-striations observed in glow discharges of inert gases at low pressures and currents. We review numerical solutions of a Fokker-Planck kinetic equation in spatially periodic electric fields under the effects of elastic and inelastic collisions of electrons with atoms. We illustrate the formation of kinetic resonances at specific field periods for different shapes of injected Electron Distribution Functions (EDF). Computer simulations illustrate how self-organization of the EDFs occurs under nonlocal conditions and how Gaussian-like peaks moving along resonance trajectories are formed in a certain range of discharge conditions. The calculated EDFs agree well with the experimentally measured EDFs for the S, P, and R striations in noble gases. We discuss how kinetic resonances affect dispersion characteristics of moving striations and mention some non-linear effects associated with glow discharge stratification. We propose further studies of stratification phenomena combining physical kinetics and non-linear physics.

Golubovskii, Yuri B.; Kolobov, Vladimir I.; Nekuchaev, Vladimir O.

2013-10-01

150

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

151

Electrical characteristics of a millisecond pulsed glow discharge  

NASA Astrophysics Data System (ADS)

A ?s and ms pulsed argon glow discharge was investigated with respect to the breakdown condition (Paschen curve). Moreover, current-voltage profiles were acquired for different discharge frequencies, pulse durations, cathode-anode spacing and discharge pressures. The breakdown voltage was dependent on the cathode material (Cu, steel, Ti and Al). No severe change in the breakdown voltage was observed for a 1 ms pulse at different frequencies. However, the theoretical breakdown curve, calculated based on the Paschen equation did not fit the experimental data. The current plots for different cathode-anode spacing showed a maximum at intermediate distance (8-10 mm). These data were consistent with mass spectrometric data acquired using the same instrument in a GC-GD-TOFMS chemical speciation study. A higher discharge frequency with constant pulse duration leads to an increase in discharge current, probably due to a more dense plasma during the pulse. This is supported by the total emission of the plasma, which was not reaching the baseline for short delays in-between the plasma pulses. In addition, the total emission of the plasma shows that at least 2 ms is needed for the plasma to reach a stable quasi steady-state. The current-voltage (traces) for different discharge pressures show a constant relationship for different pulse durations. The current-voltage relation is pressure dependent and similar to dc-glow discharges. A fast photodiode was used for precise observation of the entire Penning ionization in the afterpeak at different pressure settings.

Fliegel, Daniel; Günther, Detlef

2008-06-01

152

A Rare Stapes Abnormality  

PubMed Central

The aim of this study is to increase awareness of rare presentations, diagnostic difficulties alongside management of conductive hearing loss and ossicular abnormalities. We report the case of a 13-year-old female reporting progressive left-sided hearing loss and high resolution computed tomography was initially reported as normal. Exploratory tympanotomy revealed an absent stapedius tendon and lack of connection between the stapes superstructure and footplate. The footplate was fixed. Stapedotomy and stapes prosthesis insertion resulted in closure of the air-bone gap by 50?dB. A review of world literature was performed using MedLine. Middle ear ossicular discontinuity can result in significant conductive hearing loss. This can be managed effectively with surgery to help restore hearing. However, some patients may not be suitable or decline surgical intervention and can be managed safely conservatively. PMID:25628909

Kanona, Hala; Virk, Jagdeep Singh; Kumar, Gaurav; Chawda, Sanjiv; Khalil, Sherif

2015-01-01

153

A rare stapes abnormality.  

PubMed

The aim of this study is to increase awareness of rare presentations, diagnostic difficulties alongside management of conductive hearing loss and ossicular abnormalities. We report the case of a 13-year-old female reporting progressive left-sided hearing loss and high resolution computed tomography was initially reported as normal. Exploratory tympanotomy revealed an absent stapedius tendon and lack of connection between the stapes superstructure and footplate. The footplate was fixed. Stapedotomy and stapes prosthesis insertion resulted in closure of the air-bone gap by 50?dB. A review of world literature was performed using MedLine. Middle ear ossicular discontinuity can result in significant conductive hearing loss. This can be managed effectively with surgery to help restore hearing. However, some patients may not be suitable or decline surgical intervention and can be managed safely conservatively. PMID:25628909

Kanona, Hala; Virk, Jagdeep Singh; Kumar, Gaurav; Chawda, Sanjiv; Khalil, Sherif

2015-01-01

154

On copper diffusion in silicon measured by glow discharge mass spectrometry.  

PubMed

Copper contamination occurs frequently in silicon for photovoltaic applications due to its very fast diffusion coupled with a low solid solubility, especially at room temperature. The combination of these properties exerts a challenge on the direct analysis of Cu bulk concentration in Si by sputtering techniques like glow discharge mass spectrometry (GDMS). This work aims at addressing the challenges in quantitative analysis of fast diffusing elements in Si matrix by GDMS. N-type, monocrystalline (Czochralski) silicon samples were intentionally contaminated with Cu after solidification and consequently annealed at 900 °C to ensure a homogeneous distribution of Cu in the bulk. The samples were quenched after annealing to control the extent of the diffusion to the surface prior to the GDMS analyses, which were carried out at different time intervals from within few minutes after cooling onward. The Cu profiles were measured by high-resolution GDMS operating in a continuous direct current mode, where the integration step length was set to ?0.5 ?m over a total sputtered depth of 8-30 ?m. The temperature of the samples during the GDMS analyses was also measured in order to evaluate the diffusion. The Cu contamination of n-type Si samples was observed to be highly material dependent. The practical impact of Cu out-diffusion on the calculation of the relative sensitivity factor (RSF) of Cu in Si is discussed. PMID:25146357

Modanese, Chiara; Gaspar, Guilherme; Arnberg, Lars; Di Sabatino, Marisa

2014-11-01

155

Microfabricated glow discharge plasma (MFGDP) for ambient desorption/ionization mass spectrometry.  

PubMed

A novel ambient ionization technique for mass spectrometry, microfabricated glow discharge plasma (MFGDP), is reported. This device is made of a millimeter-sized ceramic cavity with two platinum electrodes positioned face-to-face. He or Ar plasma can be generated by a direct current voltage of several hundreds of volts requiring a total power below 4 W. The thermal plume temperature of the He plasma was measured and found to be between 25 and 80 °C at a normal discharge current. Gaseous, liquid, creamy, and solid samples with molecular weights up to 1.5 kDa could be examined in both positive and negative mode, giving limits of detection (LOD) at or below the fg/mm(2) level. The relative standard deviation (RSD) of manual sampling ranged from 10% to ~20%, while correlation coefficients of the working curve (R(2)) are all above 0.98 with the addition of internal standards. The ionization mechanisms are examed via both optical and mass spectrometry. Due to the low temperature characteristics of the microplasma, nonthermal momentum desorption is considered to dominate the desorption process. PMID:24000803

Ding, Xuelu; Zhan, Xuefang; Yuan, Xin; Zhao, Zhongjun; Duan, Yixiang

2013-10-01

156

Surface morphology of a glow discharge electrode in a solution  

NASA Astrophysics Data System (ADS)

This paper describes the surface morphology of a glow discharge electrode in a solution. In the experiments detailed in the paper, the effects of electrolysis time, solution temperature, voltage, electrolyte concentration, and surface area on the size of nanoparticles formed and their amount of nanoparticles produced were examined to study the surface morphologies of the electrodes. The results demonstrated that the amount of nanoparticles produced increased proportionally with the electrolysis time and current. When the voltages were below 140 V, surfaces with nanoparticles attached, called "Particles" type surfaces, were formed on the electrode. These surfaces changed and displayed ripples, turning into "Ripple" type surfaces, and the nanoparticle sizes increased with an increase in the amount of nanoparticles produced. In contrast, at voltages over 160 V, the surfaces of the electrodes were either "Random" or "Hole" type and the particle sizes were constant at different amount of nanoparticles produced.

Saito, Genki; Hosokai, Sou; Tsubota, Masakatsu; Akiyama, Tomohiro

2012-07-01

157

Ambipolar diffusion theory of the hot-cathode negative glow  

NASA Astrophysics Data System (ADS)

Ambipolar diffusion theory of the negative glow (NG) and Faraday dark space (FDS) of a cylindrical gas discharge maintained by thermionic emission from a hot cathode is discussed. Electrons are divided into two groups: thermionic beam electrons and plasma electrons. Radial diffusion losses are handled by introducing the usual diffusion length. Inputs to the model include probabilities of excitation and ionization by thermionic beam electrons and by plasma electrons, electron and ion temperatures and mobilities, and discharge tube radius. The model predicts the following measured quantities with good qualitative agreement: (a) combined length of NG plus FDS, (b) axial distribution of plasma electron density, and (c) ion current to cathode. The model also predicts two reversals in axial electric field: one in the NG near the cathode where axial current is supported by ambipolar diffusion, and one near the end of the FDS at the beginning of the positive column where axial current can no longer be supported by ambipolar diffusion.

Ingold, J. H.

1991-03-01

158

Flush-mounted probe diagnostics for argon glow discharge plasma.  

PubMed

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. PMID:25273724

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

159

Glow discharge cleaning of carbon fiber composite and stainless steel  

NASA Astrophysics Data System (ADS)

The paper experimentally investigates and analyses the features and mechanisms of both of oxygen removal by deuterium glow discharge from CFC, pyrolytic graphite and stainless steel subjected to irradiation in oxygen contaminated plasma. It is shown that oxygen implanted in pyrolytic graphite (PG) perpendicular to basal plates is removed after sputtering the layer slightly thicker than oxygen stopping zone (?2 nm). Fast deuterium ions penetrating into CFC during GDC transfer the trapped oxygen atoms into the bulk. Thus, much thicker surface layer has to be removed (500-1000 nm) for oxygen release. Irradiation of stainless steel in plasma leads to formation of a barrier layer with thickness (2-4 nm) equal, or slightly higher than stopping range of oxygen ions. The layer accumulates the main fraction of implanted oxygen and prevents its penetration into the bulk. After barrier layer sputtering oxygen spreads into the bulk. Parameters and conditions of optimum GDC are discussed.

Airapetov, A.; Begrambekov, L.; Brémond, S.; Douai, D.; Kuzmin, A.; Sadovsky, Ya.; Shigin, P.; Vergasov, S.

2011-08-01

160

Modelling of tokamak glow discharge cleaning I: physical principles  

NASA Astrophysics Data System (ADS)

Glow discharge cleaning (GDC) is a common technique for the conditioning of tokamak vessel walls in order to improve plasma performance and will be one of the primary conditioning techniques in ITER. The GDC discharge is a dc low-temperature plasma discharge, operated in the absence of the toroidal magnetic field, between one or more anodes inserted into the vessel, and the entire vessel wall serving as a cathode. This paper presents a self-consistent 2D model of the GDC discharge with the aim of improving fundamental understanding and predicting the wall ion current density distribution in ITER. The model combines a standard fluid model of the quasineutral plasma bulk with non-standard fluid equations for the fast electrons accelerated by the cathode sheath, based on transport coefficients and rate coefficients deduced from a Monte Carlo simulation. Examples of model results are shown in order to illustrate the general principles of the GDC discharge and the influence of the model input parameters. An important insight gained from this work is that the GDC discharge operates basically as a hollow-cathode discharge: the plasma is sustained mainly by ionization by secondary electrons emitted from the cathode, accelerated ballistically through a thin cathode sheath, penetrating the plasma as a fast electron beam, and trapped by the cathode fall surrounding the plasma on all sides. The electric field distribution inside the plasma, which determines the ion flux distribution on the vessel walls, is controlled by low-energy plasma bulk electrons. The relatively small surface area of the anode leads to the formation of an anode glow affecting the plasma uniformity. Comparisons with experimental data and predictions for ITER are presented in a companion paper.

Hagelaar, G. J. M.; Kogut, D.; Douai, D.; Pitts, R. A.

2015-02-01

161

Malicious Web Pages Detection Based on Abnormal Visibility Recognition  

Microsoft Academic Search

In recent years, Web sites have already become the attackers' main target. When attackers embed malicious code in the Web pages, they generally change the display mode of the corresponding HTML tags to make the display effect of malicious code invisible or almost invisible to the browser users. In this paper, the concept of abnormal visibility is proposed to describe

Bin Liang; Jianjun Huang; Fang Liu; Dawei Wang; Daxiang Dong; Zhaohui Liang

2009-01-01

162

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

163

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

164

Abnormal pressure in hydrocarbon environments  

USGS Publications Warehouse

Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

Law, B.E.; Spencer, C.W.

1998-01-01

165

Dynamics of multiple double layers in high pressure glow discharge in a simple torus  

SciTech Connect

Parametric characterization of multiple double layers is done during high pressure glow discharge in a toroidal vessel of small aspect ratio. Although glow discharge (without magnetic field) is known to be independent of device geometry, but the toroidal boundary conditions are conducive to plasma growth and eventually the plasma occupy the toroidal volume partially. At higher anode potential, the visibly glowing spots on the body of spatially extended anode transform into multiple intensely luminous spherical plasma blob structures attached to the tip of the positive electrode. Dynamics of multiple double layers are observed in argon glow discharge plasma in presence of toroidal magnetic field. The radial profiles of plasma parameters measured at various toroidal locations show signatures of double layer formation in our system. Parametric dependence of double layer dynamics in presence of toroidal magnetic field is presented here.

Kumar Paul, Manash, E-mail: manashkr@gmail.com [Department of Physics, National Institute of Technology Agartala, Tripura–799 046 (India); Sharma, P. K.; Thakur, A.; Kulkarni, S. V.; Bora, D. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat–382 428 (India)

2014-06-15

166

Dynamics of multiple double layers in high pressure glow discharge in a simple torus  

NASA Astrophysics Data System (ADS)

Parametric characterization of multiple double layers is done during high pressure glow discharge in a toroidal vessel of small aspect ratio. Although glow discharge (without magnetic field) is known to be independent of device geometry, but the toroidal boundary conditions are conducive to plasma growth and eventually the plasma occupy the toroidal volume partially. At higher anode potential, the visibly glowing spots on the body of spatially extended anode transform into multiple intensely luminous spherical plasma blob structures attached to the tip of the positive electrode. Dynamics of multiple double layers are observed in argon glow discharge plasma in presence of toroidal magnetic field. The radial profiles of plasma parameters measured at various toroidal locations show signatures of double layer formation in our system. Parametric dependence of double layer dynamics in presence of toroidal magnetic field is presented here.

Kumar Paul, Manash; Sharma, P. K.; Thakur, A.; Kulkarni, S. V.; Bora, D.

2014-06-01

167

Experimental installation to study the influence of acoustic oscillations on the characteristics of a glow discharge  

NASA Astrophysics Data System (ADS)

It is proposed a sketchy scheme of experimental installation to study the influence of acoustic oscillations having longitudinal, tangential, radial and combined forms on the parameters of a glow discharge.

Fadeev, S. A.; Kashapov, N. F.; Larionov, V. M.

2014-12-01

168

Synthesis of Single-Walled Carbon Nanotubes in a Glow Discharge Fine Particle Plasma  

SciTech Connect

Carbon fine particles were synthesized being negatively charged and confined in a glow discharge plasma. The deposited fine particles were analyzed by Raman spectroscopy and transmission electron microscopy (TEM) and were confirmed to include single-walled carbon nanotubes.

Imazato, N.; Imano, M.; Hayashi, Y. [Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan)

2008-09-07

169

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

170

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

171

Dependence of peak height of glow curves on heating rate in thermoluminescence  

Microsoft Academic Search

The area under the glow curve (no thermal quenching and same dose) is conserved only in TL–time plots and is not conserved (scales by a factor by which heating rate is increased) in TL–temperature plots. This increase in area under TL–temperature glow curves with increase in heating rate at a constant dose should not be interpreted as increase in sensitivity

Munish Kumar; G. Chourasiya; B. C. Bhatt; C. M. Sunta

2010-01-01

172

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

Microsoft Academic Search

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

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

2011-01-01

173

Glow-curve deconvolution of thermoluminescence curves in the simplified OTOR equation using the Hybrid Genetic Algorithm  

NASA Astrophysics Data System (ADS)

A novel method of analyzing thermoluminescence TL glow curves is presented here. This method is based on the recently derived simplified OTOR equation. It employs the Hybrid Genetic Algorithm for the extraction of the TL parameters. This method has been tested against theoretical glow-curve data that were generated using the full iteration method without any prior approximation in the OTOR model, and it has also been tested using the complex glow curve of NaCl.

Lovedy Singh, L.; Gartia, R. K.

2014-01-01

174

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

175

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

176

The deconvolution of thermoluminescence glow-curves using general expressions derived from the one trap-one recombination (OTOR) level model.  

PubMed

The new developed thermoluminescence (TL) glow-peak expressions derived from the one trap-one recombination (OTOR) level model were used to analyze the TL glow-curves recorded with linear and exponential heating function profiles under various experimental conditions. The results showed that these expressions can, accurately, analyze the TL glow-curves even with the overlapped glow-peaks. Low values of R=An/Am were reported for glow-peaks in different TL materials. A glow-peak with the possibility of An>Am was also pointed out. PMID:25464201

Sadek, A M; Eissa, H M; Basha, A M; Carinou, E; Askounis, P; Kitis, G

2014-11-11

177

Columnar discharge mode between parallel dielectric barrier electrodes in atmospheric pressure helium  

SciTech Connect

Using a fast-gated intensified charge-coupled device, end- and side-view photographs were taken of columnar discharge between parallel dielectric barrier electrodes in atmospheric pressure helium. Based on three-dimensional images generated from end-view photographs, the number of discharge columns increased, whereas the diameter of each column decreased as the applied voltage was increased. Side-view photographs indicate that columnar discharges exhibited a mode transition ranging from Townsend to glow discharges generated by the same discharge physics as atmospheric pressure glow discharge.

Hao, Yanpeng; Zheng, Bin; Liu, Yaoge [School of Electric Power, South China University of Technology, Guangzhou 510640 (China)] [School of Electric Power, South China University of Technology, Guangzhou 510640 (China)

2014-01-15

178

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

NASA Astrophysics Data System (ADS)

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 Validation Lidar (VALIDAR), Leosphere WLS70, and other standard wind sensing instruments. The performance of Goddard Lidar Observatory for Wind (GLOW) is presented for various optical thicknesses of cloud conditions. It was also compared to VALIDAR under various conditions. These conditions include clear and cloudy sky regions. The performance degradation due to the presence of cirrus clouds is quantified by comparing the wind speed error to cloud thickness. The cloud thickness is quantified in terms of aerosol backscatter ratio (ASR) and cloud optical depth (COD). ASR and COD are determined from Howard University Raman Lidar (HURL) operating at the same station as GLOW. The wind speed error of GLOW was correlated with COD and aerosol backscatter ratio (ASR) which are determined from HURL data. The correlation related in a weak linear relationship. Finally, the wind speed measurements of GLOW were corrected using the quantitative relation from the correlation relations. Using ASR reduced the GLOW wind error from 19% to 8% in a thin cirrus cloud and from 58% to 28% in a relatively thick cloud. After correcting for cloud induced error, the remaining error is due to shot noise and atmospheric variability. Shot-noise error is the statistical random error of backscattered photons detected by photon multiplier tube (PMT) can only be minimized by averaging large number of data recorded. The atmospheric backscatter measured by GLOW along its line-of-sight direction is also used to analyze error due to atmospheric variability within the volume of measurement. GLOW scans in five different directions (vertical and at elevation angles of 45° in north, south, east, and west) to generate wind profiles. The non-uniformity of the atmosphere in all scanning directions is a factor contributing to the measurement error of GLOW. The atmospheric variability in the scanning region leads to difference in the intensity of backscattered signals for scanning directions. Taking the ratio of the north (east) to south (west) and comparing the statistical differences lead to a weak linear relation between atmospheric variability and line-of-sights wind speed differences. This relation was used to make correction which reduced by about 50%.

Bacha, Tulu

179

Thermally stimulated luminescence glow curve structure of ?-irradiated CaB4 O7 :Dy.  

PubMed

Thermally stimulated luminescence glow curves of CaB4 O7 :Dy samples after ?-irradiation showed glow peaks at ~335, 530 and 675 K, with a heating rate of 2 K/s. The main peak at 530 K was analyzed using the Tmax -Tstop method and was found to be composed of at least five overlapping glow peaks. A curve-fitting program was used to perform computerized glow curve deconvolution (CGCD) analysis of the complex peak of the dosimetric material of interest. The kinetic parameters, namely activation energy (E) and frequency factor (s), associated with the main glow peak of CaB4 O7 :Dy at 520 K were evaluated using peak shape (PS) and isothermal luminescence decay (ILD) methods. In addition, the kinetics was determined to be first order (b =1) by applying the additive dose method. The activation energies and frequency factors obtained using PS and ILD methods are calculated to be 0.72 and 0.72 eV and 8.76 × 10(5) and 1.44 × 10(6) /s, respectively. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25428760

Ak?n, Aycan; Ekdal, Elçin; Tuncer Arslanlar, Yasemin; Ayvac?kl?, Mehmet; Karal?, Turgay; Can, Nurdo?an

2014-11-27

180

Determination of trap parameters for thermoluminescence glow peaks of red thermoluminescence of quartz from Japan  

NASA Astrophysics Data System (ADS)

Red thermoluminescence in quartz has been generally observed in samples from volcanic deposits or archaeological burnt materials. Red thermoluminescence emission quartz has gained attention as a radiation dosimeter for thermoluminescence dating due to the high-dose saturation level and long-term stability of the thermoluminescence signal. The technique for this application can be improved with an understanding of various trap parameters associated with thermoluminescence glow peaks. The repeated initial rise and computerized glow curve deconvolution methods are used to determine the number of thermoluminescence glow peaks and trap parameters for red thermoluminescence from two types of quartz (Tazawa and Yuda samples) from Japan. For both quartz samples, the glow curves were best described as a superposition of seven glow peaks with activation energies of 0.76-1.95 eV and 0.89-1.91 eV for the Tazawa and Yuda samples, respectively. These results provide useful information for the investigation of the intrinsic characteristics of quartz crystals in the research fields relevant to dating and dosimetry.

Song, K. W.; Kim, K. B.; Hong, D. G.

181

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

182

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

183

Immune abnormalities in myelodysplastic syndromes.  

PubMed

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

1985-08-01

184

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

185

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.

186

Physics of self-sustained oscillations in the positive glow corona  

SciTech Connect

The physics of self-sustained oscillations in the phenomenon of positive glow corona is presented. The dynamics of charged-particle oscillation under static electric field has been briefly outlined; and, the resulting self-sustained current oscillations in the electrodes have been compared with the measurements from the positive glow corona experiments. The profile of self-sustained electrode current oscillations predicted by the presented theory qualitatively agrees with the experimental measurements. For instance, the experimentally observed saw-tooth shaped electrode current pulses are reproduced by the presented theory. Further, the theory correctly predicts the pulses of radiation accompanying the abrupt rises in the saw-tooth shaped current oscillations, as verified from the various glow corona experiments.

Cho, Sung Nae [Micro Devices Group, Micro Systems Laboratory, 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)

2012-07-15

187

A computerized glow curve analysis (GCA) method for WinREMS thermoluminescent dosimeter data using MATLAB.  

PubMed

A computerized glow curve analysis (GCA) program for handling of thermoluminescence data originating from WinREMS is presented. The MATLAB program fits the glow peaks using the first-order kinetics model. Tested materials are LiF:Mg,Ti, CaF(2):Dy, CaF(2):Tm, CaF(2):Mn, LiF:Mg,Cu,P, and CaSO(4):Dy, with most having an average figure of merit (FOM) of 1.3% or less, with CaSO(4):Dy 2.2% or less. Output is a list of fit parameters, peak areas, and graphs for each fit, evaluating each glow curve in 1.5 s or less. PMID:21561783

Harvey, John A; Rodrigues, Miesher L; Kearfott, Kimberlee J

2011-09-01

188

Computerized glow curve deconvolution of thermoluminescent emission from polyminerals of Jamaica Mexican flower  

NASA Astrophysics Data System (ADS)

The aim of this work is to study the main thermoluminescence (TL) characteristics of the inorganic polyminerals extracted from dehydrated Jamaica flower or roselle (Hibiscus sabdariffa L.) belonging to Malvaceae family of Mexican origin. TL emission properties of the polymineral fraction in powder were studied using the initial rise (IR) method. The complex structure and kinetic parameters of the glow curves have been analysed accurately using the computerized glow curve deconvolution (CGCD) assuming an exponential distribution of trapping levels. The extension of the IR method to the case of a continuous and exponential distribution of traps is reported, such as the derivation of the TL glow curve deconvolution functions for continuous trap distribution. CGCD is performed both in the case of frequency factor, s, temperature independent, and in the case with the s function of temperature.

Favalli, A.; Furetta, C.; Zaragoza, E. Cruz; Reyes, A.

189

Green long-after-glow luminescence of Tb3+ in Sr2SiO4  

NASA Astrophysics Data System (ADS)

The green long-after-glow luminescence from Tb3+-doped Sr2SiO4 phosphors, which are synthesized by the high temperature solid state reaction in a reductive atmosphere, is observed in this paper. The results show that under ultraviolet excitation, the obtained phosphors produce an intense green-lighting-emission from the Tb3+, and the green-lighting long-after-glow luminescence related to Tb3+ can last half an hour after the irradiation source has been removed. Moreover, the effects of co-doping Li+, Dy3+, Er3+, Gd3+, and Yb3+ with Tb3+ on the decay properties and thermoluminescence properties are investigated to confirm the long-after-glow mechanism.

Wang, Qi; Qiu, Jian-Bei; Song, Zhi-Guo; Zhou, Da-Cheng; Xu, Xu-Hui

2014-06-01

190

Neurophysiological model of the normal and abnormal human pupil  

NASA Technical Reports Server (NTRS)

Anatomical, experimental, and computer simulation studies were used to determine the structure of the neurophysiological model of the pupil size control system. The computer simulation of this model demonstrates the role played by each of the elements in the neurological pathways influencing the size of the pupil. Simulations of the effect of drugs and common abnormalities in the system help to illustrate the workings of the pathways and processes involved. The simulation program allows the user to select pupil condition (normal or an abnormality), specific site along the neurological pathway (retina, hypothalamus, etc.) drug class input (barbiturate, narcotic, etc.), stimulus/response mode, display mode, stimulus type and input waveform, stimulus or background intensity and frequency, the input and output conditions, and the response at the neuroanatomical site. The model can be used as a teaching aid or as a tool for testing hypotheses regarding the system.

Krenz, W.; Robin, M.; Barez, S.; Stark, L.

1985-01-01

191

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.

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

1990-01-01

192

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

193

Colour vision in the glow-worm Lampyris noctiluca (L.) (Coleoptera: Lampyridae): evidence for a green-blue chromatic mechanism  

Microsoft Academic Search

Male glow-worms Lampyris noctiluca find their bioluminescent mates at night by phototaxis. There is good evidence that location of mates by lampyrid beetles is achieved by a single spectral class of photoreceptor, whose spectral sensitivity is tuned to the bioluminescent spectrum emitted by conspecifics, and is achromatic. We ask whether glow-worm phototaxis involves interactions between two spectral classes of photoreceptor.

David Booth; Alan J. A. Stewart; Daniel Osorio

2004-01-01

194

Multiple steady states in a radio frequency chlorine glow discharge Eray S. Aydil and Demetre J. Economoua)  

E-print Network

Multiple steady states in a radio frequency chlorine glow discharge Eray S. Aydil and Demetre J in a 13.56 MHz chlorine glow discharge in a parallel plate radial flow reactor. Measurements of the flux of atomic chlorine (Cl) concentration and etch rate of polysilicon for different states of the plasma

Economou, Demetre J.

195

[A boy with nail abnormalities].  

PubMed

A 12-year-old boy consulted the dermatologist for nail abnormalities. Three weeks earlier, he was treated with doxycycline 100 mg BID for 10 days because of erythema chronicum migrans. Following sun exposure, the patient had developed distal onycholysis surrounded by a hyperpigmented zone. He was diagnosed with doxycycline-induced photo-onycholysis. PMID:23838405

Atiq, Nasirah; van Meurs, Tim

2013-01-01

196

Second Order Fluid Glow Discharge Model Sustained by Different Source Terms  

NASA Astrophysics Data System (ADS)

Behavior of charged particles in a DC low pressure glow discharge is studied. The electric properties of the glow discharge in argon, maintained by a constant source term with uniform electron and ion generation, between two plane electrodes or by secondary electron emission at the cathode, are determined. A fluid model is used to solve self-consistently the first three moments of the Boltzmann equation coupled with the Poisson equation. The stationary spatial distribution of the electron and ion densities, the electric potential, the electric field, and the electron energy, in a two-dimensional (2D) configuration, are presented.

Guendouz, D.; Hamid, A.; Hennad, A.

2011-10-01

197

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

198

Detrapping of tungsten nanoparticles in a direct-current argon glow discharge  

NASA Astrophysics Data System (ADS)

Nanoparticles are grown from the sputtering of a tungsten cathode in a direct current argon glow discharge. Laser light scattering of a vertical laser sheet going through the plasma reveals that the dust particle cloud is compressed and pushed towards the anode during the discharge. Scanning electron microscopy images of substrates exposed to the plasma for given durations show that dust particles are continuously falling down on the anode during the discharge. These observations are explained by the fact that the electrostatic force at the negative glow-anode sheath boundary cannot balance the ion drag, gravity, and thermophoresis forces for particles of more than a few tens of nanometres in diameter.

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

2014-12-01

199

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

NASA Astrophysics Data System (ADS)

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.

1994-06-01

200

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

201

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

202

Normal and abnormal skin color.  

PubMed

The varieties of normal skin color in humans range from people of "no color" (pale white) to "people of color" (light brown, dark brown, and black). Skin color is a blend resulting from the skin chromophores red (oxyhaemoglobin), blue (deoxygenated haemoglobin), yellow-orange (carotene, an exogenous pigment), and brown (melanin). Melanin, however, is the major component of skin color ; it is the presence or absence of melanin in the melanosomes in melanocytes and melanin in keratinocytes that is responsible for epidermal pigmentation, and the presence of melanin in macrophages or melanocytes in the dermis that is responsible for dermal pigmentation. Two groups of pigmentary disorders are commonly distinguished: the disorders of the quantitative and qualitative distribution of normal pigment and the abnormal presence of exogenous or endogenous pigments in the skin. The first group includes hyperpigmentations, which clinically manifest by darkening of the skin color, and leukodermia, which is characterized by lightening of the skin. Hypermelanosis corresponds to an overload of melanin or an abnormal distribution of melanin in the skin. Depending on the color, melanodermia (brown/black) and ceruloderma (blue/grey) are distinguished. Melanodermia correspond to epidermal hypermelanocytosis (an increased number of melanocytes) or epidermal hypermelanosis (an increase in the quantity of melanin in the epidermis with no modification of the number of melanocytes). Ceruloderma corresponds to dermal hypermelanocytosis (abnormal presence in the dermis of cells synthesizing melanins) ; leakage in the dermis of epidermal melanin also exists, a form of dermal hypermelanosis called pigmentary incontinence. Finally, dyschromia can be related to the abnormal presence in the skin of a pigment of exogenous or endogenous origin. PMID:23522626

Ortonne, J P

2012-12-01

203

Glutamatergic Neurotransmission Abnormalities and Schizophrenia  

Microsoft Academic Search

\\u000a Schizophrenia affects approximately 1% of the adult population worldwide and requires lifelong therapy. Hyperfunction of the\\u000a dopaminergic system has long been hypothesized as the underlying cause of schizophrenia. However, this hypothesis explains\\u000a mostly the positive symptoms associated with schizophrenia. Several lines of evidence point to the glutamatergic system and\\u000a suggest that abnormalities in this system may play a crucial role

Yogesh Dwivedi; Ghanshyam N. Pandey

204

Surface Treatment of Polyethylene Terephthalate Film Using Atmospheric Pressure Glow Discharge in Air  

Microsoft Academic Search

Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of

Zhi Fang; Yuchang Qiu; Hui Wang

2004-01-01

205

Atmospheric Pressure Glow Discharge Plasma and Surface Modification of PET Textile by APGDP  

Microsoft Academic Search

Comparing with traditional chemistry method, surface modification of Polyethylene terephthalate (PET) fabrics by using of Atmospheric Pressure Glow Discharge Plasma (APGDP) has many advantages, such as low cost, low pollution and low energy consumption. So it has huge application in textile industry due to no requirement for vacuum system. In this paper, the generation and the characteristics of APGDP on

Biao Gu; Ru Chen; Yin Xu; Xiang Deng; Qingjun Shi

2002-01-01

206

Comparison of Dielectric Barrier Discharge and Atmospheric Pressure Glow Discharge for Surface Modification of PET Film  

Microsoft Academic Search

Non-equilibrium plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In the present work polyethylene terephthalate (PET) film surface is modified using the non-equilibrium plasma generated by the atmospheric pressure glow discharge (APGD) and dielectric barrier discharge (DBD) in ambient air. The differences in discharge characteristics between APGD and

Zhi Fang; Yuchang Qiu; Edmund Kuffel

2007-01-01

207

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

208

Qualitative gas temperature distribution in positive DC glow corona using spectral image processing in atmospheric air  

NASA Astrophysics Data System (ADS)

An experimental method of determining a qualitative two-dimensional image of the gas temperature in stationary atmospheric nonthermal plasma by spectral image processing was presented. In the experiment, a steady-state glow corona discharge was generated by applying a positive DC voltage to a rod-plane electrode in synthetic air. The changes in the gas temperature distribution due to the amplitude of applied voltage and the ambient gas pressure were investigated. Spectral images of a positive DC glow corona were taken using a gated ICCD camera with ultranarrow band-pass filters, corresponding to the head and tail of a N2 second positive system band (0–2). The qualitative gas temperature was obtained from the emission intensity ratio between the head and tail of the N2 second positive system band (0–2). From the results, we confirmed that the gas temperature and its distribution of a positive DC glow corona increased with increasing applied voltage. In particular, just before the sparkover voltage, a distinctly high temperature region was formed in the positive DC glow at the tip of the rod electrode. In addition, the gas temperature decreased and its distribution spread diffusely with decreasing ambient gas pressure.

Matsumoto, Takao; Inada, Yoichi; Shimizu, Daisuke; Izawa, Yasuji; Nishijima, Kiyoto

2015-01-01

209

Images of biological samples undergoing sterilization by a glow discharge at atmospheric pressure  

Microsoft Academic Search

Among the various industrial uses of the glow discharge at atmospheric pressure (GDAP), biological applications such as sterilization are under investigation. In this paper, we present images of a liquid medium (Luria-Bertani broth with tetracycline) contaminated by Escherichia coli bacteria (strain PER 322) undergoing plasma treatment. In most cases, it is found that an exposure time of two to 20

Mounir Laroussi; Gary S. Sayler; Battle B. Glascock; Bruce McCurdy; Mary E. Pearce; Nathan G. Bright; Chad M. Malott

1999-01-01

210

Plasma degradation of dyes in water with contact glow discharge electrolysis  

Microsoft Academic Search

Contact glow discharge electrolysis (CGDE) of two dyes, weak acid brilliant red B and weak acid flavine G, was investigated under different concentrations, temperature and mediums. From the variation of their concentration with the reaction time, it was demonstrated that the oxidation would be a first-order reaction. On the base line of UV spectra of solution in the degradation process,

Jinzhang Gao; Xiaoyan Wang; Zhongai Hu; Hualing Deng; Jingguo Hou; Xiaoquan Lu; Jingwan Kang

2003-01-01

211

Glow discharge-like characteristics of a OAUGDP revealed by computer modeling  

Microsoft Academic Search

Summary form only given. Previously, we experimentally and numerically demonstrated the existence and operation of the one atmosphere uniform glow discharge plasma (OAUGDP). In this discharge, the electron energy and density, as well as other plasma characteristics, are functions of time. This time-dependence is best studied by computer modeling, and has been extensively carried out for an atmospheric helium plasma.

R. B. Gadri; J. Reece Roth

1998-01-01

212

Influences of gas flow on atmospheric pressure glow discharge in helium  

Microsoft Academic Search

Atmospheric pressure glow discharge (APGD) was produced in a 5-mm helium gap between two plane-parallel electrodes of 50 mm in diameter, each covered by a 1-mm thick quartz plate. The influence of the helium gas flowing in parallel through the helium gap on APGD was studied. The helium flow rate varies up to 12 liter per minute, corresponding to helium

H. Luo; Z. Liang; B. Lv; X. Wang; Z. Guan; L. Wang

2008-01-01

213

Radio-Frequency Glow Discharges of Different Gases Using Bare Metallic Electrodes at Atmospheric Pressure  

Microsoft Academic Search

The images of the atmospheric-pressure glow discharges driven by the radio-frequency power supply using He, Ar, N2, O2, air, or their mixture as the primary plasma-working gas are presented in this paper. The plasma jet, produced using the planar-type plasma generator behaving like a \\

He-Ping Li; Guo Li; Sen Wang; Pei-Si Le; Cheng-Yu Bao

2008-01-01

214

XVI. On the distribution of electric force and rise of temperature in the glow discharge  

Microsoft Academic Search

1. 1. It is suggested that the results of Messrs. Finch and Cowen's experiments upon gaseous combustion and ignition in electric discharges might be explained equally well upon the thermal theory.2. 2. Experiments made to test the accuracy of the two-probe method of' determining the electric force in glow discharges are described. These lead to the conclusion that above a

John M. Holm

1931-01-01

215

Nanosecond repetitively pulsed discharges in air at atmospheric pressure—the glow regime  

NASA Astrophysics Data System (ADS)

In atmospheric-pressure air preheated to 1000 K, nanosecond repetitively pulsed (NRP) discharges are shown to generate three plasma discharge regimes. In addition to the well-known corona and spark regimes, there exists a glow-like regime that develops through an initial cathode-directed streamer, followed by a return wave of potential redistribution. The applied electric field is then switched off before the formation of the cathode fall, resulting in an 'imminent' glow discharge. Previously, this regime had been observed only at 2000 K in air at atmospheric pressure. Measurements of the plasma dynamics, current-voltage characteristics, gas temperature and plasma chemistry of the excited species N2(B), N2(C), N_{2}^{+}(B) , NO(A) and O(3p 5P) in the pulsed glow regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that this glow regime generates an estimated electron number density of 1013 cm-3, while consuming only 1-10 µJ per pulse and heating the gas by less than 200 K.

Pai, David Z.; Stancu, Gabi D.; Lacoste, Deanna A.; Laux, Christophe O.

2009-11-01

216

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 Wilkins/io9 Posted 10.19.2010 at 12:15 pm LED Lights Could Be Implanted Under Skin Photo courtesy of iO9 LEDs are, on small scales, the cheapest, most reliable, and most technologically powerful light sources

Rogers, John A.

217

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

218

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

219

The Spectrum of the Light emitted by the Glow-worm  

Microsoft Academic Search

I AM not aware that any account has been published of the nature of the light emitted by the glow-worm, and therefore venture to send the results of some observations I made on the evenings of the 21st and 22nd of the month.

John Conroy

1882-01-01

220

Spatially resolved optical emission spectroscopy of the secondary glow observed during biasing of a microwave plasma  

Microsoft Academic Search

A secondary glow region is commonly observed between the main plasma ball and the substrate during biased enhanced nucleation (BEN) of diamond films grown using the process of microwave plasma-enhanced chemical vapour deposition. Under conditions of very careful optimisation BEN can allow (100) oriented polycrystalline diamond films to be grown on (100) silicon substrate; such films are industrial important. Recently

Michael D Whitfield; Richard B Jackman; J. S Foord

2000-01-01

221

Measurements of levels of non-ionising radiation emitted by a glow discharge display globe  

Microsoft Academic Search

Measurements of electric and magnetic fields and of optical radiation emissions from a glow discharge display globe are reported. This type of discharge globe can be purchased for domestic entertainment and display purposes. Reference levels for electric field strength recommended by the National Radiological Protection Board are exceeded at distances closer than 0.5 m from the centre of the globe.

C. M. H. Driscoll; M. J. Whillock; R. P. Blackwell

1990-01-01

222

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

2011-12-01

223

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

224

Modelling of tokamak glow discharge cleaning II: comparison with experiment and application to ITER  

NASA Astrophysics Data System (ADS)

The primary function of the ITER glow discharge cleaning (GDC) system will be the preparation of in-vessel component surfaces prior to the machine start-up. It may also contribute to tritium removal in the nuclear phase. In GDC, conditioning efficiency is strongly dependent on the homogeneity of the flux of ions impinging onto wall surfaces. In order to assess the wall particle flux distribution in ITER, a novel 2D multi-fluid model, described in a companion paper, has recently been developed and is benchmarked here against both experimental glow discharge data obtained in a small laboratory chamber with cylindrical geometry and from two large toroidal devices: the JET tokamak and the RFX reverse field pinch. In the laboratory plasma, simulated and measured plasma electron density and temperature are in a good agreement in the negative glow region, while discrepancies exist in the anode glow, where the fluid description of the model is inaccurate due to long mean free paths of electrons. Calculated and measured ion flux distribution profiles in RFX are found in good agreement, whereas in JET comparison it is more difficult, due to the complex geometry of the first wall which leads to local inhomogeneities in the measured flux. Simulations of H2-GDC for ITER with one or two anodes indicate fairly homogeneous plasma parameters and wall ion flux in the negative glow at 0.5?Pa, a commonly used gas pressure for GDC in existing fusion devices. Although the axisymmetric geometry in the model does not allow all seven ITER anodes to be powered simultaneously in the simulations, the results can be extrapolated to the full system and predict ion current densities on wall surfaces close to the simple expectation of total anode current divided by wall surface area (0.21?A?m?2), which is relevant to GDC in JET and other machines.

Kogut, D.; Douai, D.; Hagelaar, G.; Pitts, R. A.

2015-02-01

225

Effects of various dopants on NaCl and KCl glow curves  

NASA Astrophysics Data System (ADS)

We have measured the thermoluminescence of a number of NaCl and KCl crystals following irradiation at ambient temperature with the same dose (10 kGy) of Co-60 ? rays. We compare the TL of pure samples and of samples doped with europium and calcium ions. In the case of NaCl, additional impurities (Ni, Pb, Sr and Cr) have been investigated. The effects of irradiation are determined using optical absorption and thermoluminescence. Factors investigated include the effects of different dopants on TL glow curves and the effects of thermal annealing samples at 400 °C before the irradiation. Changes in TL glow curves relating to changes in the state of aggregation of the impurities produced by pre-irradiation annealing are reported in this paper. Perhaps the most significant effect is a temperature shift of the main glow peak in pre-annealed compared to not pre-annealed samples in the case of Eu doped NaCl. The magnitude of the shift depends on the concentration of the Eu dopant. Shifts are also observed for Ni and Sr impurities in NaCl, but not for Ca and Cr impurities in NaCl. In the case of KCl, glow peaks generally occur at similar temperatures in doped samples and do not shift when doped samples are pre-annealed. Here the main effect of different impurities is to influence the size of the emission and not the structure of the glow curve. Results are discussed in terms of current theories of thermoluminescence.

Davidson, A. T.; Kozakiewicz, A. G.; Derry, T. E.; Comins, J. D.; Suszynska, M.

2004-06-01

226

How to Interpret Abnormal Pap Smear Results  

MedlinePLUS

... Cervical Cancer | How to Interpret Abnormal Pap Smear Results What does an abnormal Pap smear mean? A ... are located in your cervix or uterus. These results mean that some of your glandular cells are ...

227

Pathology Case Study: Sensory Abnormalities  

NSDL National Science Digital Library

The Department of Pathology at the University of Pittsburgh Medical Center has compiled a wide range of pathology case studies to aid students and instructors in the medical/health science field. This particular case focuses on a 30-year-old man with a history of focal numbness, bladder and bowel dysfunction, and progressive sensory abnormalities. The patientâÂÂs history, images from an MRI, microscopic images of a specimen collected during his laminectomy, and final diagnosis are provided in this case for your review. Students will find this resource especially helpful, as it provides experience with patient history, lab results, and diagnostics.

Duggal, Neil; Hammond, Robert R.; Lownie, Steven P.; Smith, Sharyn

2007-12-10

228

Lower extremity abnormalities in children.  

PubMed

Rotational and angular problems are two types of lower extremity abnormalities common in children. Rotational problems include intoeing and out-toeing. Intoeing is caused by one of three types of deformity: metatarsus adductus, internal tibial torsion, and increased femoral anteversion. Out-toeing is less common than intoeing, and its causes are similar but opposite to those of intoeing. These include femoral retroversion and external tibial torsion. Angular problems include bowlegs and knock-knees. An accurate diagnosis can be made with careful history and physical examination, which includes torsional profile (a four-component composite of measurements of the lower extremities). Charts of normal values and values with two standard deviations for each component of the torsional profile are available. In most cases, the abnormality improves with time. A careful physical examination, explanation of the natural history, and serial measurements are usually reassuring to the parents. Treatment is usually conservative. Special shoes, cast, or braces are rarely beneficial and have no proven efficacy. Surgery is reserved for older children with deformity from three to four standard deviations from the normal. PMID:12924829

Sass, Pamela; Hassan, Ghinwa

2003-08-01

229

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

230

Cardiac abnormalities in liver cirrhosis.  

PubMed Central

Cirrhosis is associated with several circulatory abnormalities. A hyperkinetic circulation characterized by increased cardiac output and decreased arterial pressure and peripheral resistance is typical. Despite this hyperkinetic circulation, some patients with alcoholic cirrhosis have subclinical cardiomyopathy with evidence of abnormal ventricular function unmasked by physiologic or pharmacologic stress. Florid congestive alcoholic cardiomyopathy develops in a small percentage, but the concurrent presence of cirrhosis seems to retard the occurrence of overt heart failure. Even nonalcoholic cirrhosis may be associated with latent cardiomyopathy, although overt heart failure is not observed. Tense ascites is associated with some cardiac compromise, and removing or mobilizing ascitic fluid by paracentesis or peritoneovenous shunting results in short-term increases in cardiac output. Cirrhosis also appears to be associated with a decreased risk of major coronary atherosclerosis and an increased risk of bacterial endocarditis. Small hemodynamically insignificant pericardial effusions may be seen in ascitic patients. The release of atrial natriuretic peptide appears to be unimpaired in cirrhosis, although the kidney may be hyporesponsive to its natriuretic effects. PMID:2690463

Lee, S S

1989-01-01

231

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

232

Impact of reading pre-irradiation background signal on the post-irradiation glow curves of thermoluminescence dosimeters.  

PubMed

Due to their sensitivity, signal reproducibility and stability, lithium fluoride thermoluminescence dosimeters are widely used in many applications. It was noticed that post-irradiation glow curves of LiF dosimeters that had undergone pre-irradiation background dose measurements dramatically differed from the curves of dosimeters irradiated without such preliminary measurements. Three types of dosimeters were studied in this respect, namely, TLD-700, TLD-600, and TLD-100. Impact of pre-irradiation background measurements on the glow curve areas, peak positions, and individual peak intensities were investigated using computerized glow curve analysis. Similarities in the behavior of the dosimeters of all three types were found. Areas of the glow peaks P?a, P?, P?, P?, and P? increased. Peak P? grew most significantly, followed by P?, and P?. Also, one of the common features was a shift of T(max) of P? to higher temperatures. Pre-irradiation background readings increase the total area of the glow curve in general and affect relative intensities and positions of specific peaks, which changes the shape of the glow curve. It is strongly recommended to perform pre-irradiation background measurements for all LiF-based dosimeters regardless of the values of the background doses relative to the radiation doses to be given. PMID:21724407

Abd El-Hafez, A I; Maghraby, A

2011-10-01

233

Study of the glow curves of TLD exposed to thermal neutrons.  

PubMed

The glow curves of thermoluminescent dosimeters (TLD600, TLD700 and MCP), exposed to a mixed field of thermal neutrons and gamma photons are analysed. The fluence values of thermal neutrons used, comparable with those used in radiotherapy, allow one to define the reliability of the TLDs, in particular the most sensitive MCP, in this radiation field and to get information on the dose absorbed values. The glow curves obtained have been deconvoluted using general order kinetics and the observed differences for the different LET components have been analysed. In particular, the ratio of the n(0) parameter of two different peaks seems to allow to discriminate the different contributions of neutrons and gamma photons in the beam. PMID:17502321

Triolo, A; Brai, M; Marrale, M; Gennaro, G; Bartolotta, A

2007-01-01

234

Surface modification of PDMS using atmospheric glow discharge polymerization of tetrafluoroethane for immobilization of biomolecules  

NASA Astrophysics Data System (ADS)

In this study an atmospheric glow discharge with a fluorocarbon gas as precursor was used to modify the surface of polydimethyl siloxane (PDMS -[(CH 3) 2SiO] n-). The variation in protein immobilizing capability of PDMS was studied for different times of exposure. It was observed that the concentration of proteins adsorbed on the surface varied in an irregular manner with treatment time. The fluorination results in the formation of a thin film of fluorocarbon on the PDMS surface. The AFM and XPS data suggest that the film cracks due to stress and regains its uniformity thereafter. This Stranski-Krastanov growth model of the film was due to the high growth rate offered by atmospheric glow discharge.

Anand, V.; Ghosh, S.; Ghosh, M.; Rao, G. M.; Railkar, R.; Dighe, R. R.

2011-08-01

235

Boundary Layer Flow Control with a One Atmosphere Uniform Glow Discharge Surface Plasma  

NASA Technical Reports Server (NTRS)

Low speed wind tunnel data have been acquired for planar panels covered by a uniform, glow-discharge surface plasma in atmospheric pressure air known as the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP). Streamwise and spanwise arrays of flush, plasma-generating surface electrodes have been studied in laminar, transitional, and fully turbulent boundary layer flow. Plasma between symmetric streamwise electrode strips caused large increases in panel drag, whereas asymmetric spanwise electrode configurations produced a significant thrust. Smoke wire flow visualization and mean velocity diagnostics show the primary cause of the phenomena to be a combination of mass transport and vortical structures induced by strong paraelectric ElectroHydroDynamic (EHD) body forces on the flow.

Roth, J. Reece; Sherman, Daniel M.; Wilkinson, Stephen P.

1998-01-01

236

Nanostructural evolution of steel and titanium alloys exposed to glow-discharge plasma  

NASA Astrophysics Data System (ADS)

We have investigated the formation process of nanostructures with different dimensions and the modification of materials after their treatment by low-energy ion irradiation in glow-discharge plasma. The materials under investigation were armco-iron, high-speed steel and titanium alloys. Low-energy ion impact was carried out in a specially constructed plasma generator, where materials were irradiated by ions of residual gases in vacuum. The ion energy was 1-3 keV. After the low-energy ion treatment, microhardness of the irradiated materials, their fine dislocation structures and electrical resistivity were investigated. Simultaneously, a computer simulation of material behavior after a glow-discharge plasma impact was made. We showed that nanostructures may be formed by self-organizing processes development in nonlinear media after low-energy irradiation. This result is confirmed by computer simulation of the influence of low-energy ions on nonlinear crystal structures.

Tereshko, I.; Abidzina, V.; Tereshko, A.; Elkin, I.

2007-08-01

237

Attenuation of single-tone ultrasound by an atmospheric glow discharge plasma barrier  

NASA Astrophysics Data System (ADS)

Propagation of 143 kHz ultrasound through an atmospheric pressure glow discharge in air was studied experimentally. The plasma was a continuous dc discharge formed by a multipin electrode system. Distributions of the gas temperature were also obtained in and around the plasma using laser-induced Rayleigh scattering technique. Results show significant attenuation of the ultrasound by the glow discharge plasma barrier (up to -24 dB). The results indicate that sound attenuation does not depend on the thickness of the plasma and attenuation is caused primarily by reflection of the sound waves from the plasma due to the sharp gas temperatures gradients that form at the plasma boundary. These gradients can be as high as 80 K/mm.

Stepaniuk, Vadim P.; Ioppolo, Tindaro; Ötügen, M. Volkan; Sheverev, Valery A.

2010-09-01

238

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

239

On the possibility of using commercial software packages for thermoluminescence glow curve deconvolution analysis.  

PubMed

This paper explores the possibility of using commercial software for thermoluminescence glow curve deconvolution (GCD) analysis. The program PEAKFIT has been used to perform GCD analysis of complex glow curves of quartz and dosimetric materials. First-order TL peaks were represented successfully using the Weibull distribution function. Second-order and general-order TL peaks were represented accurately by using the Logistic asymmetric functions with varying symmetry parameters. Analytical expressions were derived for determining the energy E from the parameters of the Logistic asymmetric functions. The accuracy of these analytical expressions for E was tested for a wide variety of kinetic parameters and was found to be comparable to the commonly used expressions in the TL literature. The effectiveness of fit of the analytical functions used here was tested using the figure of merit (FOM) and was found to be comparable to the accuracy of recently published GCD expressions for first- and general-order kinetics. PMID:12382713

Pagonis, V; Kitis, G

2002-01-01

240

Effect of hydrogen glow discharge conditioning on Zr/Al getter pumps  

SciTech Connect

Zr/Al bulk getter pumps are presently being considered for use in the Tokamak Fusion Test Reactor (TFTR) to reduce impurities and limit the recycling of hydrogenic species. It is necessary that these pumps not be adversely affected by the hydrogen glow discharge cleaning (GDC) which is planned as part of the routine TFTR vessel wall conditioning. The GDC procedure involves the use of a dc glow discharge with a 400 V bias voltage. The total fluence of hydrogenic ions given to the affected surfaces during a typical conditioning period is 10/sup 18/ cm/sup -2/. We have investigated the effects of typical GDC runs on a getter-pump module containing 25 g of Zr/Al mounted in a 100 liter test stand. Pumping speed, capacity, and regeneration characteristics have been studied after various exposures to GDC.

Dylla, H.F.; Cecchi, J.L.; Ulrickson, M.

1981-01-01

241

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

242

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

243

Model of microsecond pulsed glow discharge in hollow cathode for mass spectrometry  

NASA Astrophysics Data System (ADS)

A new model for microsecond pulsed glow discharge in a hollow cathode and its afterglow is described. The model is based on the Monte-Carlo method together with a new method for electrical field calculation, which is based on some phenomenological laws of plasma behavior. The afterglow model uses continuity and Poisson equations. A qualitative agreement between the model results and results published in experimental and theoretical works is demonstrated. Some processes in the microsecond pulsed discharge in the hollow cathode, such as sputtering, ionization and transfer of sample, are investigated. The model is successfully used for the optimization of the operational parameters of the time-of-flight mass spectrometer with ionization by microsecond pulsed glow discharge in a hollow cathode.

Voronov, M.; Ganeev, A.

2009-05-01

244

Charge formation in polyimide films under the action of low-frequency glow-discharge plasma  

SciTech Connect

The authors showed previously that treatment of the surface of PM polyimide films (produced in Russia) with a low-frequency (LF) glow-discharge plasma resulted in considerable changes in their wettability and surface energy. Similar results were also obtained abroad for Kapton films. It was shown that the formation of polar NH and OH groups (in unbound carboxyl groups) occurred in the surface layer as a result of decyclization processes. In addition, the concentration of free radicals was shown to increase. These changes in chemical structure are probably responsible for increasing the hydrophilicity of the surface of polyimide films. However, estimations showed that the concentrations of free radicals were comparatively low. Apparently, the significant changes of the polar component of the surface energy that were observed (by 2-3 orders of magnitude) cannot be fully explained by the formation of radicals. The study of the effect of LF glow discharge on polytetrafluoroethylene revealed an essential decrease of the contact angles on the film surface and formation of the surface electric charge. It was shown that the neutralization of this charge resulted in increased contact angles for polytetrafluoroethylene nearly up to the values for the original films. Thus, the charged (or electret) states appear to play an important part in modifying the energetic characteristics of the film surface in the case of polytetrafluoroethylene. Similar states may also result from the glow-discharge treatment of polyimide and play a certain part in modifying the surface characteristics of this polymer. In this work the authors carried out measurements of the charge generated in polyimide films modified with glow discharge and investigated the mechanism of charge accumulation in the samples.

Drachev, A.I.; Gil`man, A.B.; Tuzov, L.S.; Potapov, V.K. [Karpov Institute of Physical Chemistry, Moscow (Russian Federation)

1995-07-01

245

Physicomathematical analysis of surface modification of polymers by glow discharge in SF 6 + N 2 medium  

Microsoft Academic Search

In this paper, surface modification of dielectric polymers, having different physical and chemical properties (polyimide—PI, polystyrene—PS, Polyethylene terephthalate—PET), treated in contourized glow discharge in SF6+N2 gas medium near cathode was studied. The electret state, formed as a result of modification, caused an increase in the surface energy. Surface charge densities and contact angles of dielectric polymers whose surfaces were activated

H. Z. Alisoy; A. Baysar; G. T. Alisoy

2005-01-01

246

Physicomathematical analysis of surface modification of polymers by glow discharge in SF6+N2 medium  

Microsoft Academic Search

In this paper, surface modification of dielectric polymers, having different physical and chemical properties (polyimide---PI, polystyrene---PS, Polyethylene terephthalate---PET), treated in contourized glow discharge in SF6+N2 gas medium near cathode was studied. The electret state, formed as a result of modification, caused an increase in the surface energy. Surface charge densities and contact angles of dielectric polymers whose surfaces were activated

H. Z. Alisoy; A. Baysar; G. T. Alisoy

2005-01-01

247

Influence of gap width on discharge asymmetry in atmospheric pressure glow dielectric barrier discharges  

SciTech Connect

In this letter, a one-dimensional fluid model is used to investigate the mechanism of discharge asymmetry in atmospheric pressure helium glow dielectric barrier discharges (GDBDs). By observing the evolutionary process between the successive peak currents, the effect of the gap width on the discharge asymmetry is thoroughly discussed. It is shown that when the gap width is too large, the very severe nonuniformity of electric field distribution over the gas gap leads to the discharge asymmetry.

Dai, D. [School of Electric Power, South China University of Technology, Guangzhou 510641 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); Hou, H. X. [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); Hao, Y. P. [School of Electric Power, South China University of Technology, Guangzhou 510641 (China)

2011-03-28

248

Frequency and voltage dependence of glow and pseudoglow discharges in helium under atmospheric pressure  

Microsoft Academic Search

The pseudoglow and glow discharge behavior of a 0.5-mm metallic-dielectric electrode gap in helium under atmospheric pressure was examined as a function of ac voltage between 0.3 and 32 kHz. The number of discharge current pulses per half-cycle within the pseudoglow was found to diminish with rising frequency, as opposed to the increase observed with rising voltage. The reduction in

Ion Radu; Ray Bartnikas; Michael R. Wertheimer

2003-01-01

249

Dielectric Electrode Surface Effects on Atmospheric Pressure Glow Discharges in Helium  

Microsoft Academic Search

Comparative experimental and theoretical studies are carried with 0.5-mm gaps using metallic and dielectric electrodes to examine the influence of dielectric surfaces upon the behavior of atmospheric pressure glow discharges in helium at frequencies of up to 22 kHz. The charge transfers associated with the discrete discharge current pulses exhibit a direct proportionality to the difference between the breakdown Vb

R. Bartnikas; I. Radu; M. R. Wertheimer

2007-01-01

250

Ozone production by nanoporous dielectric barrier glow discharge in atmospheric pressure air  

SciTech Connect

This study is aimed at demonstrating plasma-chemical ozone production based on low temperature atmospheric pressure glow discharge through nanoporous dielectric barriers. The 20 kHz ac driven discharge is formed in air or oxygen gas flowing in the axial direction of the cylindrical plasma reactor containing four parallel aluminum rods covered with nanoporous alumina films. The discharge utilizing nanoporous dielectric barrier is more uniform and more energy efficient in ozone generation than the discharge through smooth-surface dielectric barriers.

Cho, J. H.; Koo, I. G.; Choi, M. Y.; Lee, W. M. [Department of Chemistry and Division of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of)

2008-03-10

251

High frequency glow discharges at atmospheric pressure with micro-structured electrode arrays  

Microsoft Academic Search

Micro-structured electrode (MSE) arrays allow the generation of large-area uniform glow discharges over a wide pressure range up to atmospheric pressure. The electrode widths, thicknesses and distances in the micrometre range are realized by means of modern micro-machining and galvanic techniques. The electrode distance, the gap width d, is small enough to generate sufficiently high electric field strengths to ignite

L. Baars-Hibbe; P. Sichler; C. Schrader; N. Lucas; K.-H. Gericke; S. Büttgenbach

2005-01-01

252

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

Microsoft Academic Search

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

Wen-Ting Sun; Guo Li; He-Ping Li; Cheng-Yu Bao; Hua-Bo Wang; Shi Zeng; Xing Gao; Hui-Ying Luo

2007-01-01

253

Dynamic behaviors and stability of atmospheric glow plasmas at 1 - 10 MHz  

Microsoft Academic Search

Summary form only given. Radio-frequency atmospheric-pressure glow discharges (APGD) have been used in a wide range of applications including etching, deposition, surface sterilization and biological manipulation. Most RF APGD are generated at 13.56 MHz, of which the current understanding is sound and the application prospect is excellent. Recently we have shown that plasma stability of RF APGD can be improved

D. W. Liu; J. J. Shi; M. G. Kong

2006-01-01

254

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

Microsoft Academic Search

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

Guo Li; He-Ping Li; Li-Yan Wang; Sen Wang; Hong-Xin Zhao; Wen-Ting Sun; Xin-Hui Xing; Cheng-Yu Bao

2008-01-01

255

Atmospheric pressure glow discharge desorption mass spectrometry for rapid screening of pesticides in food  

Microsoft Academic Search

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 Andradeet al. (Andradeetal.,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

Matthias Conradin Jecklin; Gerardo Gamez; David Touboul; Renato Zenobi

2008-01-01

256

Glow Worms as a Tourist Attraction in Springbrook National Park: Visitor Attitudes and Economic Issues  

Microsoft Academic Search

Insect-based tourism mainly caters to a niche market, but its popularity has been growing in recent years. Despite its popularity this form of tourism has remained under-researched and in a sense its contribution to the tourism industry has gone mostly unnoticed. This paper reports the results of a study undertaken on one form of popular insect-based tourism, namely glow worms.

Clevo Wilson; Clement A. Tisdell; David Merritt

2004-01-01

257

Dynamic of the Dust Structures under Magnetic Field Effect in DC Glow Discharges  

SciTech Connect

In this work, we investigate dust structures in the striation of DC glow discharges under magnetic field actions. The dependence of rotation frequency of dusty plasma structures as a function of the magnetic field was investigated. For various magnetic fields kinetic temperatures of the dust particles, diffusion coefficients, and effective coupling coefficient {gamma}* have been determined. Obtained results are analyzed and compared with theoretical predictions.

Vasiliev, M. M.; D'yachkov, L. G.; Antipov, S. N.; Petrov, O. F.; Fortov, V. E. [Joint Institute for High Temperatures, RAS, Izhorskaya 13/19, Moscow, Russia, 125412 (Russian Federation)

2008-09-07

258

Clostridium beijerinckii mutant obtained atmospheric pressure glow discharge generates enhanced electricity in a microbial fuel cell.  

PubMed

A Clostridium beijerinckii mutant M13 was derived from C. beijerinckii NCIMB 8052 by atmospheric pressure glow discharge. C. beijerinckii M13 generated a maximum output power density of 79.2 mW m(-2) and a maximum output voltage of 230 mV in a microbial fuel cell containing 1 g glucose l(-1) as carbon source and 0.15 g methyl viologen l(-1) as an electron carrier. PMID:25179822

Liu, Jun; Guo, Ting; Wang, Dong; Ying, Hanjie

2015-01-01

259

Glow discharge mass spectrometry studies on nephrite minerals formed by different metallogenic mechanisms and geological environments  

Microsoft Academic Search

Glow discharge mass spectrometry (GD-MS) was applied to study the nephrite minerals formed by different metallogenic mechanisms and geological environments from deposits in China, Canada, New Zealand and Russia. The GD-MS analysis and multivariate statistic analysis results indicated that two types of nephrite minerals of different metallogenic mechanisms could be classified by some typical elements. It was shown that serpentine-related

Bilige Siqin; Rong Qian; Shangjun Zhuo; Fuxi Gan; Min Dong; Yanfen Hua

260

Femtosecond Laser Ablation Particle Introduction to a Liquid Sampling-Atmospheric Pressure Glow Discharge Ionization Source  

Microsoft Academic Search

This work describes the use of a compact, liquid sampling atmospheric pressure glow discharge (LS-APGD) ionization source to ionize metal particles within a laser ablation aerosol. Mass analysis was performed with a Thermo Scientific Exactive Mass Spectrometer which utilizes an orbitrap mass analyzer capable of producing mass resolution exceeding M\\/M > 160,000. The LS-APGD source generates a low-power plasma between

Anthony J. Carado; C. Derrick Quarles; Andrew M. Duffin; Charles J. Barinaga; Richard Russo; R. Kenneth Marcus; Gregory C. Eiden; David W. Koppenaal

2012-01-01

261

Surface Modification of Commercial Low-Carbon Steel using Glow Discharge Nitrogen Plasma and its Characterization  

NASA Astrophysics Data System (ADS)

Plasma nitriding under glow discharge nitrogen plasma has been undertaken on laboratory scale for surface engineering of commercial low carbon steels. The treatment has been shown to confer exceptional improvement in surface properties, viz., hardness and corrosion resistance. The results have been discussed in light of microstructural changes occurring on steel surface and its interior as a result of Fickian nitrogen diffusion and correlated with influences of nitriding-temperature and alloying elements (Mn, Nb, and Si) in steel.

Srikanth, S.; Saravanan, P.; Joseph, Alphonsa; Ravi, K.

2013-09-01

262

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

263

Adults with Chromosome 18 Abnormalities.  

PubMed

The identification of an underlying chromosome abnormality frequently marks the endpoint of a diagnostic odyssey. However, families are frequently left with more questions than answers as they consider their child's future. In the case of rare chromosome conditions, a lack of longitudinal data often makes it difficult to provide anticipatory guidance to these families. The objective of this study is to describe the lifespan, educational attainment, living situation, and behavioral phenotype of adults with chromosome 18 abnormalities. The Chromosome 18 Clinical Research Center has enrolled 483 individuals with one of the following conditions: 18q-, 18p-, Tetrasomy 18p, and Ring 18. As a part of the ongoing longitudinal study, we collect data on living arrangements, educational level attained, and employment status as well as data on executive functioning and behavioral skills on an annual basis. Within our cohort, 28 of the 483 participants have died, the majority of whom have deletions encompassing the TCF4 gene or who have unbalanced rearrangement involving other chromosomes. Data regarding the cause of and age at death are presented. We also report on the living situation, educational attainment, and behavioral phenotype of the 151 participants over the age of 18. In general, educational level is higher for people with all these conditions than implied by the early literature, including some that received post-high school education. In addition, some individuals are able to live independently, though at this point they represent a minority of patients. Data on executive function and behavioral phenotype are also presented. Taken together, these data provide insight into the long-term outcome for individuals with a chromosome 18 condition. This information is critical in counseling families on the range of potential outcomes for their child. PMID:25403900

Soileau, Bridgette; Hasi, Minire; Sebold, Courtney; Hill, Annice; O'Donnell, Louise; Hale, Daniel E; Cody, Jannine D

2014-11-19

264

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

265

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

266

Validity of the similarity law for the glow discharges in non-plane-parallel gaps  

NASA Astrophysics Data System (ADS)

The glow discharges in the gaps geometrically similar to that used in glow discharge cleaning of the International Thermonuclear Experimental Reactor (ITER) were numerically simulated based on a two-dimensional fluid model in which the linear dimensions of gap A are two times that of gap B and the pressure of gap A is half that of gap B. Under an applied voltage of 1000 V, the physical parameters at the corresponding point pz in these two gaps were compared. It was found that the electric potential U(pz), the reduced field E(pz)/p and the electron temperature Te(pz) are equal in values for these two gaps, but the electron density ne(pz) and ion density ni(pz) for gap B are four times that of gap A. All these parameter ratios are the same as that defined by similarity law, which confirmed that the similarity law is valid for the glow discharges in non-plane-parallel gaps.

Fu, Yangyang; Luo, Haiyun; Zou, Xiaobing; Wang, Xinxin

2014-12-01

267

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

268

Atmospheric sampling glow discharge ionizataion and triple quadrupole tandem mass spectrometry for explosives vapor detection  

SciTech Connect

The detection and identification of trace vapors of hidden high explosives is an excellent example of a targeted analysis problem. It is desirable to push to ever lower levels the quantity or concentration of explosives material that provides an analytical signal, while at the same time discriminating against all other uninteresting material. The detection system must therefore combine high sensitivity with high specificity. This report describes the philosophy behind the use of atmospheric sampling glow discharge ionization, which is a sensitive, rugged, and convenient means for forming anions from explosives molecules, with tandem mass spectrometry, which provides unparalleled specificity in the identification of explosives-related ions. Forms of tandem mass spectrometry are compared and contrasted to provide a summary of the characteristics to be expected from an explosives detector employing mass spectrometry/mass spectrometry. The instrument developed for the FAA, an atmospheric sampling glow discharge/triple quadrupole mass spectrometer, is described in detail with particular emphasis on the ion source/spectrometer interface and on the capabilities of the spectrometer. Performance characteristics of the system are also described as they pertain to explosives of interest including a description of an automated procedure for the detection and identification of specific explosives. A comparison of various tandem mass spectrometers mated with atmospheric sampling glow discharge is then described and preliminary studies with a vapor preconcentration system provided by the FAA will be described.

McLuckey, S.A.; Goeringer, D.E.; Asano, K.G.; Hart, K.J.; Glish, G.L.; Grant, B.C.; Chambers, D.M.

1993-08-01

269

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

270

Normal Modes  

NSDL National Science Digital Library

Play with a 1D or 2D system of coupled mass-spring oscillators. Vary the number of masses, set the initial conditions, and watch the system evolve. See the spectrum of normal modes for arbitrary motion. See longitudinal or transverse modes in the 1D system.

Simulations, Phet I.; Dubson, Michael; Olson, Jon; Paul, Ariel; Loeblein, Trish

2012-05-14

271

Evaluation of abnormal liver function tests  

PubMed Central

Interpretation of abnormalities in liver function tests is a common problem faced by clinicians. This has become more common with the introduction of automated routine laboratory testing. Not all persons with one or more abnormalities in these tests actually have liver disease. The various biochemical tests, their pathophysiology, and an approach to the interpretation of abnormal liver function tests are discussed in this review. PMID:12840117

Limdi, J; Hyde, G

2003-01-01

272

Holoprosencephaly due to Numeric Chromosome Abnormalities  

PubMed Central

Holoprosencephaly (HPE) is the most common malformation of the human forebrain. When a clinician identifies a patient with HPE, a routine chromosome analysis is often the first genetic test sent for laboratory analysis in order to assess for a structural or numerical chromosome anomaly. An abnormality of chromosome number is overall the most frequently identified etiology in a patient with HPE. These abnormalities include trisomy 13, trisomy 18, and triploidy, though several others have been reported. Such chromosome number abnormalities are almost universally fatal early in gestation or in infancy. Clinical features of specific chromosome number abnormalities may be recognized by phenotypic manifestations in addition to the HPE. PMID:20104610

Solomon, Benjamin D.; Rosenbaum, Kenneth N.; Meck, Jeanne M.; Muenke, Maximilian

2009-01-01

273

Mode Segregation Analysis of Pulsar B1237+25  

NASA Astrophysics Data System (ADS)

Pulsar radiation exhibits “modes” of two types: “profile modes” refer to intervals (seconds to hours) during which the individual pulse trains differ significantly in total power, polarization or other properties—thus exhibiting distinct average profiles—and “orthogonal polarization modes” (OPMs) representing radiation propagating parallel or perpendicular to the projected magnetic field direction. Pulsar B1237+25 provides a remarkable example of both types of modal effects. Moreover, its five-component profile results from a line-of-sight passage through both an outer and inner cone of emission and a central core beam. Here, we report on analysis of an Arecibo 327-MHz observation wherein the pulses were segregated first according to whether they belonged to the star's “normal” or “abnormalmode and then according to the primary or secondary OPM. Using these methods we develop a new understanding of the pulsar's abnormal mode and identify intensity-dependent aberration/retardation in the abnormal core emission.

Smith, E. M.; Rankin, J. M.

2012-12-01

274

[Neuromuscular abnormalities in critical illness].  

PubMed

The spectrum of neuromuscular disease encountered in today's intensive care units (ICU) has evolved over the last few decades. However, in spite of many studies on neuromuscular disorders complicating critical illness as well as its epidemiology, etiology, treatment and prognosis, several key areas remain unclear. Two main groups are found among these neuromuscular abnormalities. The first group includes primary neuromuscular disorders present on admission to the ICU in which a possible etiology can be identified. Guillain-Barré syndrome and myasthenia gravis are two of the most common diseases admitted to ours units. In the second group, weakness is acquired in the ICU in the absence of preexisting neuromuscular disease. It is believed to reflect illnesses or treatments occurring in the ICU. Critical illness polyneuropathy (CIP) is the most clearly defined neuromuscular complication in this group. However, although we have better knowledge of its clinical, diagnosis, and prognosis features, its pathophysiological substrate has not been fully elucidated. Neuromuscular junction defects and specially myopathies, that frequently coexist with CIP, are the others main causes of acquired weakness in critically ill patients. Advances in understanding of these neuromuscular disorders could have an important impact in terms of developing effective preventive and therapeutic interventions that could help to improve the poor prognosis of these patients. PMID:19406085

Amaya Villar, R; Garnacho-Montero, J; Rincón Ferrari, M D

2009-04-01

275

The XXXXY sex chromosome abnormality.  

PubMed

The most common sex chromosome complex in sex chromatin-positive males with Klinefelter's syndrome is XXY. When the complex is XXYY or XXXY, the clinical findings do not seem to differ materially from those seen in XXY subjects, although more patients with these intersexual chromosome complements need to be studied to establish possible phenotypical expressions of the chromosomal variants.Two male children with an XXXXY sex chromosome abnormality are described. The data obtained from the study of these cases and five others described in the literature suggest that the XXXXY patient is likely to have congenital defects not usually seen in the common form of the Klinefelter syndrome. These include a triad of (1) skeletal anomalies (including radioulnar synostosis), (2) hypogenitalism (hypoplasia of penis and scrotum, incomplete descent of testes and defective prepubertal development of seminiferous tubules), and (3) greater risk of severe mental deficiency.That the conclusions are based on data from a small number of patients is emphasized, together with the need for a cytogenetic survey of a large control or unselected population. PMID:13969480

BARR, M L; CARR, D H; POZSONYI, J; WILSON, R A; DUNN, H G; JACOBSON, T S; MILLER, J R; LEWIS, M; CHOWN, B

1962-10-27

276

Ultrastructural Differentiation of Abnormal Scars  

PubMed Central

Summary Aim: To evaluate the differences between keloid and hypertrophic scars by biochemical and ultrastructural techniques. Method: Over 1000 patients with different types of scars were studied and followed up for a period of 20 years. The histochemical and biochemical analysis with respect to the composition of the extracellular matrix of the dermis was conducted. At the ultrastructural level, collagen deposition and assembly were studied using electron microscopy. The rate of proliferation and metabolic activity of the dermal fibroblasts isolated from the normal skin and scar biopsies were studied to assess the cause of excess matrix deposition in scar tissues. Results: Evaluation of different types of scars showed that both keloid and hypertrophic scars have excess matrix deposition in terms of collagen and proteoglycans. Keloid shows a high amount of acid-soluble collagen. The assembly of collagen fibrils is also abnormal in keloids. Studies on the proliferation and metabolic activity showed that keloid fibroblasts have a higher rate of proliferation and metabolic activity than fibroblasts from hypertrophic scars and normal skin. Finally, keloid fibroblasts show high and intense staining for the endoplasmic reticulum, suggesting a possible reason for high activity of these fibroblasts. Conclusion: Keloids and hypertrophic scars show distinct ultrastructural patterns of both collagen deposition and assembly. These parameters could be refined by further research, and they would thus serve as a useful tool for surgeons to distinguish different types of scars and adopt suitable therapeutic strategies. PMID:21990984

Meenakshi, J.; Jayaraman, V.; Ramakrishnan, K.M..; Babu, M.

2005-01-01

277

Optical and electrical characteristics of air dielectric barrier discharges in mode transition at atmospheric pressure  

NASA Astrophysics Data System (ADS)

Atmospheric pressure dielectric barrier discharges (DBDs) have a wide range of industrial applications, generally exhibiting either filamentary or diffuse (i.e. glow) discharges. The focus of this investigation is on the formation mechanisms of the discharge current pulse width, on the order of tens of microseconds, accompanied by a light source formation, which is called a light source (LS) mode in air DBDs at atmospheric pressure. From a macroscopic point of view, the characteristics of the discharge current in the LS mode are similar with those of the glow mode. The optical and electrical characteristics of air DBDs at atmospheric pressure are investigated in the transition from the filamentary mode to the LS mode by measuring the optical emission spectroscopy and electrical signals. It is shown that in the manual increasing voltage stage, the vibrational temperature almost never changes and the gas temperature, electron temperature, dielectric capacitance, gas voltage (Vg) and discharge power (P) increase with an increase in the applied voltage. In the automatic decreasing voltage stage, all of these parameters, except Vg and P, increase with a decrease in the voltage. But, when the voltage decreases to a minimum value corresponding to the LS mode, P reaches a maximum value. In this paper, the variations of these parameters are analyzed and discussed in detail. The formation of the LS mode originates from the secondary electrons. The formation mechanisms of the secondary electrons are also discussed.

Wang, Weiwei; Liu, Feng; Wang, Xue; Han, Haiyan; Huang, Yanbin; Liang, Rongqing

2015-04-01

278

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

279

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

280

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

281

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

282

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

283

Abnormal Web Usage Control by Proxy Strategies.  

ERIC Educational Resources Information Center

Approaches to designing a proxy server with Web usage control and to making the proxy server effective on local area networks are proposed to prevent abnormal Web access and to prioritize Web usage. A system is implemented to demonstrate the approaches. The implementation reveals that the proposed approaches are effective, such that the abnormal

Yu, Hsiang-Fu; Tseng, Li-Ming

2002-01-01

284

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

285

Ultrastructurally abnormal mitochondria in the pituitary oncocytoma  

Microsoft Academic Search

Summary A pituitary adenoma in a 67-year-old man was characterized by abundant mitochondria and identified as an oncocytoma, which clinically and histologically appeared as a chromophobe adenoma. In addition to the numerous mitochondria within the neoplastic cells, structurally abnormal mitochondria were also present. Compared with other pituitary oncocytomas reported in the literature, abnormally structured mitochondria appear rare among the mitochondrial

H. H. Goebel; F. Schulz; B. Rama

1980-01-01

286

Chromosomal Anomalies in Abnormal Human Pregnancies  

Microsoft Academic Search

Objective: The aim of this study was to describe the cytogenetic observations on abnormal human pregnancies (anembryonic pregnancy, early fetal loss, and hydatidiform moles), and to detect the most frequent or typical chromosomal aberration for anembryonic pregnancy and early fetal loss. Study Design: Abnormal pregnancies were divided into three clinical and morphological groups: (a) anembryonic pregnancy; (b) early fetal loss,

1998-01-01

287

Breathing abnormalities in sleep in achondroplasia  

Microsoft Academic Search

Overnight sleep studies were performed in 20 subjects with achondroplasia to document further the respiratory abnormalities present in this group. Somatosensory evoked potentials (SEPs) were recorded in 19 of the subjects to screen for the presence of brainstem abnormalities, which are one of the potential aetiological mechanisms. Fifteen children aged 1 to 14 years, and five young adults, aged 20

K A Waters; F Everett; D Sillence; E Fagan; C E Sullivan

1993-01-01

288

Irradiation of silver and agar/silver nanoparticles with argon, oxygen glow discharge plasma, and mercury lamp.  

PubMed

The irradiation effect of argon, oxygen glow discharge plasma, and mercury lamp on silver and agar/silver nanoparticle samples is studied. The irradiation time dependence of the synthesized silver and agar/silver nanoparticle absorption spectra and their antibacterial effect are studied and compared. In the agar/silver nanoparticle sample, as the irradiation time of argon glow discharge plasma or mercury lamp increases, the peak intensity and the full width at half maximum, FWHM, of the surface plasmon resonance absorption band is increased, however a decrease of the peak intensity with oxygen glow plasma has been observed. In the silver nanoparticle sample, as the irradiation time of argon, oxygen glow discharge plasma or mercury lamp increases, the peak intensity of the surface plasmon resonance absorption band is increased, however, there is no significant change in the FWHM of the surface plasmon resonance absorption band. The SEM results for both samples showed nanoparticle formation with mean size about 50 nm and 40 nm respectively. Throughout the irradiation time with the argon, oxygen glow discharge plasma or mercury lamp, the antibacterial activity of several kinds of Gram-positive and Gram-negative bacteria has been examined. PMID:25184109

Ahmad, Mahmoud M; Abdel-Wahab, Essam A; El-Maaref, A A; Rawway, Mohammed; Shaaban, Essam R

2014-01-01

289

The Chemically Synthesized Ageladine A-Derivative LysoGlow84 Stains Lysosomes in Viable Mammalian Brain Cells and Specific Structures in the Marine Flatworm Macrostomum lignano.  

PubMed

Based on the chemical structure and the known chemical synthesis of the marine sponge alkaloid ageladine A, we synthesized the ageladine A-derivative 4-(naphthalene-2-yl)-1H-imidazo[4,5-c]pyridine trifluoroacetate (LysoGlow84). The two-step synthesis started with the Pictet-Spengler reaction of histamine and naphthalene-2-carbaldehyde to a tetrahydropyridine intermediate, which was dehydrogenated with activated manganese (IV) oxide to LysoGlow84. Structure and purity of the synthesized LysoGlow84 were confirmed by NMR spectroscopy and mass spectrometry. The fluorescence intensity emitted by LysoGlow84 depended strongly on the pH of the solvent with highest fluorescence intensity recorded at pH 4. The fluorescence maximum (at 315 nm excitation) was observed at 440 nm. Biocompatibility of LysoGlow84 was investigated using cultured rat brain astrocytes and the marine flatworm Macrostomum lignano. Exposure of the astrocytes for up to 6 h to micromolar concentrations of LysoGlow84 did not compromise cell viability, as demonstrated by several viability assays, but revealed a promising property of this compound for staining of cellular vesicles. Conventional fluorescence microscopy as well as confocal scanning microscopy of LysoGlow84-treated astrocytes revealed co-localization of LysoGlow84 fluorescence with that of LysoTracker® Red DND-99. LysoGlow84 stained unclear structures in Macrostomum lignano, which were identified as lysosomes by co-staining with LysoTracker. Strong fluorescence staining by LysoGlow84 was further observed around the worms' anterior gut and the female genital pore which were not counterstained by LysoTracker Red. Thus, LysoGlow84 is a new promising dye that stains lysosomes and other acidic compartments in cultured cells and in worms. PMID:25679913

Mordhorst, Thorsten; Awal, Sushil; Jordan, Sebastian; Petters, Charlotte; Sartoris, Linda; Dringen, Ralf; Bickmeyer, Ulf

2015-01-01

290

On the mode switching timescales of pulsar PSR B0329+54  

NASA Astrophysics Data System (ADS)

Chen et al. (2011) found that the durations (timescales) of the normal and abnormal modes of PSR B0329+54 follow a gamma distribution, and constrained the parameters of the distribution function. In this paper, we perform a further analysis on the relationship between the timescales of the two modes. The ratio between the durations of a normal mode and the succeeding abnormal mode is calculated for 54 such pairs. It is found that the cumulative distribution function (CDF) of the ratio is consistent with the CDF obtained by assuming random mode switching, suggesting that the two modes work independently.

Wang, Hong-Guang; Chen, Jian-Ling; Wen, Zhi-Gang; Pi, Fei-Peng

2013-03-01

291

Glow discharge spectrometry for the characterization of nuclear and radioactively contaminated environmental samples  

NASA Astrophysics Data System (ADS)

Glow discharge (GD) spectrometry as applied to characterize nuclear samples as well as for the determination of radionuclides in environmental samples is reviewed. The use of instrumentation for direct current (d.c.) glow discharge mass spectrometry (GDMS) and radio frequency glow discharge optical emission spectrometry (rf GDOES), installed inside a glove-box for the handling of radioactive samples as well as the two installations and their analytical possibilities, is described in detail. The applications of GD techniques for the characterization of samples of nuclear concern both with respect to their major and trace elements, as well as to the matrix isotopic composition are presented. Procedures for quantitative determination of major, minor, and trace elements in conductive samples are reported. As for non-conductive samples three different approaches for their measurement can be followed. Namely, the use of rf sources, the mixing of the sample with a binder conducting host matrix, and the use of a secondary cathode. In the case of oxide-based samples, the employment of a tantalum secondary cathode, acting as an oxygen getter, reduces the availability of oxygen to form polyatomic species and to produce quenching. Considerations on the use of the relative sensitivity factors (RSFs) in different matrices are reported. The analytical capabilities of GDMS are compared with ICP-MS in terms of accuracy, precision, and detection limit for the determination of trace elements in uranium oxide specimens. As for the determination of isotopic composition, GDMS was found to be competitive with thermal ionisation mass spectrometry (TIMS) as well as for bulk determinations of major elements with titration methods. Applications of GDMS to the determination of radioisotopes in environmental samples, as well for depth profiling of trace elements in oxide layers, are discussed.

Betti, Maria; Aldave de las Heras, Laura

2004-09-01

292

Electrophysiological abnormalities in the transplanted human heart.  

PubMed Central

Fourteen relatively long term survivors of cardiac transplantation underwent systematic electrophysiological evaluation and ambulatory electrocardiographic monitoring. Six patients had prolonged conduction intervals during sinus rhythm. Sinus node function could be assessed in all donor atria and in 10 recipient atria. Sinus node recovery times were prolonged in four of the donor atria and in six recipient atria. In the donor atria abnormalities of sinus node automaticity were invariably associated with abnormalities of sinoatrial conduction. Four patients showed functional duality of atrioventricular nodal conduction during programmed extrastimulation, but no patient developed re-entrant arrhythmia. During ambulatory electrocardiographic monitoring no pronounced tachyarrhythmias were recorded. Three patients showed abnormalities of sinus node impulse formation. All three patients had abnormal sinus node recovery times during their electrophysiological study. Long term survivors of cardiac transplantation have a high incidence of electrophysiological abnormalities. Abnormalities of donor sinus node function are probably of clinical significance. The clinical significance of abnormalities detected within the atrioventricular conduction system of the denervated heart remains to be elucidated. PMID:6360191

Bexton, R S; Nathan, A W; Hellestrand, K J; Cory-Pearce, R; Spurrell, R A; English, T A; Camm, A J

1983-01-01

293

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

SciTech Connect

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. [Department of Optics and Spectroscopy, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); International Laboratory “Nonlocal Plasma in Nanotechnology and Medicine”, ITMO University, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States); Kudryavtsev, A. A.; Stepanova, O. M. [Department of Optics and Spectroscopy, St. Petersburg State University, St. Petersburg 199034 (Russian Federation); Kurlyandskaya, I. P. [International Laboratory “Nonlocal Plasma in Nanotechnology and Medicine”, ITMO University, Kronverkskiy pr. 49, St. Petersburg 197101 (Russian Federation); St. Petersburg University of State Fire Service of EMERCOM RF, Murmansk Branch, Murmansk 183040 (Russian Federation)

2014-09-15

294

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.

295

Submillimeter-Wave Observations of C_3N^- in AN Extended Negative Glow Discharge  

NASA Astrophysics Data System (ADS)

Extended negative glow and hollow anode discharges are found to be good sources of negative ions, such as CN^-, C_2H^-, and C_4H^-, for observations of pure rotational lines in the submillimeter-wave region. Thaddeus et al. detected C_3N^- in a glow discharge in HC_3N diluted in Ar buffer gas, and its rotational lines up to 378 GHz (J=39-38) were measured. In the present investigation, this anion has been observed in an extended negative glow discharge in a gas mixture of C_2N_2 (˜ 2 mTorr) and C_2H_2 (˜ 3 mTorr) in Ar buffer gas of ˜ 15 mTorr at the cell wall temperature of 230 K. The optimum discharge current was 2-4 mA with 250 Gauss longitudinal magnetic field. The rotational lines of up to J=51-50 in the 495 GHz region have been measured, and the improved rotational and centrifugal distortion constants are obtained. In the discharge optimum for production of C_3N^-, neither CN nor C_3N was detected with a similar signal accumulation time used for observations of the anion. However, this reaction has been found to be an excellent source for HC_3N, and the dominant formation mechanism of C_3N^- is likely to be the dissociative electron attachment to HC_3N. The radiative association of C_3N with electrons seems to be unlikely at least for the extended negative glow discharge. Apparently HC_3N is synthesized by a fast neutral and neutral reaction (C_2{H}_2 + CN ? HC_3{N} + {H} It is interesting to see that an isomer, HCCNC, is also detected in the discharge, although the number density of this species is found to be about two orders of magnitude smaller than that of HC_3N. Another isomer, HNCCC, has also been observed with much weaker signal intensity. This species might have been produced by the dissociative recombination reaction of HC_3NH^+ with electrons, although the detection of this cation has not been successful in this type of discharge. T. Amano, J. Chem. Phys., 129, 244305 (2008). P. Thaddeus et al.,Astrophys. J., 677,1132-1139 (2008) K. Graupner et al., New J. Phys., 8,117 (2006) I. R. Sims et al.,Chem. Phys. Lett., 211, 461-468(1992) D. E. Woon and E. Herbst,Astrophys. J., 477, 204-208(1997)

Amano, T.

2009-06-01

296

Influence of annular magnet on discharge characteristics in enhanced glow discharge plasma immersion ion implantation  

SciTech Connect

A permanent annular magnet positioned at the grounded anode alters the discharge characteristics in enhanced glow discharge plasma immersion ion implantation (EGD-PIII). The nonuniform magnetic field increases the electron path length and confines electron motion due to the magnetic mirror effect and electron-neutral collisions thus occur more frequently. The plasma potential and ion density measured by a Langmuir probe corroborate that ionization is improved near the grounded anode. This hybrid magnetic field EGD-PIII method is suitable for implantation of gases with low ionization rates.

Li Liuhe; Wang Zhuo [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Department 702, School of Mechanical and Automation Engineering, Beijing University of Aeronautics and Astronautics, Beijing (China); Lu Qiuyuan; Fu, Ricky K. Y.; Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Pang Enjing; Dun Dandan; He Fushun; Li Fen [Department 702, School of Mechanical and Automation Engineering, Beijing University of Aeronautics and Astronautics, Beijing (China)

2011-01-10

297

Power enhancement in chemical oxygen-iodine lasers by iodine predissociation via corona/glow discharge  

NASA Astrophysics Data System (ADS)

The gain and power in a supersonic chemical oxygen-iodine laser (COIL) are enhanced by applying dc corona/glow discharge in the transonic section of the secondary flow in the supersonic nozzle, dissociating I2 prior to its mixing with O2(?1). The loss of O2(?1) consumed for dissociation is thus reduced, and the consequent dissociation rate downstream of the discharge increases, resulting in up to 80% power enhancement. The implication of this method for COILs operating beyond the specific conditions reported here is assessed.

Katz, A.; Dahan, Z.; Rybalkin, V.; Waichman, K.; Barmashenko, B. D.; Rosenwaks, S.

2007-04-01

298

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

299

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

NASA Astrophysics Data System (ADS)

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, He-Ping; Wang, Li-Yan; Wang, Sen; Zhao, Hong-Xin; Sun, Wen-Ting; Xing, Xin-Hui; Bao, Cheng-Yu

2008-06-01

300

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

301

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

302

Spatially-resolved observation of glow discharge plasma for atomic emission spectrometry.  

PubMed

An imaging spectrograph equipped with a CCD detector was employed to measure two-dimensional emission images from a glow discharge plasma in atomic emission spectrometry. The emission images at Zn I 334.50 nm for a zinc sample and at Cu I 324.75 nm for a copper sample could be obtained. Their emission intensities were not uniform in the radial direction of the plasma region but became weaker at larger distance from the central zone. The two-dimensional distribution would result from a spatial variation in the excitation efficiency of the plasma and thus provide useful information for understanding the excitation processes occurring in the plasma. PMID:18469457

Zenitani, Yoshitaka; Wagatsuma, Kazuaki

2008-05-01

303

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

304

Study of TL glow curves of YPO 4 double doped with lanthanide ions  

Microsoft Academic Search

Thermoluminescence (TL) emission spectra and TL glow curves of samples of YPO4:Ce3+, Ln3+ (Ln3+ = Pr3+, Nd3+, Sm3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+) and YPO4:Tb3+, Ln3+ (Ln3+ = Nd3+, Ho3+, Dy3+, Sm3+, Tm3+) were measured in order to investigate the nature of the trapping centres and to compare the lanthanide energy levels in the band gap with a predictive energy level scheme developed earlier.

Adrie J. J. Bos; Pieter Dorenbos; Aurélie Bessière; Aurélie Lecointre; Melanie Bedu; Marco Bettinelli; Fabio Piccinelli

305

Sleep Physiology, Abnormal States, and Therapeutic Interventions  

PubMed Central

Sleep is essential. Unfortunately, a significant portion of the population experiences altered sleep states that often result in a multitude of health-related issues. The regulation of sleep and sleep-wake cycles is an area of intense research, and many options for treatment are available. The following review summarizes the current understanding of normal and abnormal sleep-related conditions and the available treatment options. All clinicians managing patients must recommend appropriate therapeutic interventions for abnormal sleep states. Clinicians' solid understanding of sleep physiology, abnormal sleep states, and treatments will greatly benefit patients regardless of their disease process. PMID:22778676

Wickboldt, Alvah T.; Bowen, Alex F.; Kaye, Aaron J.; Kaye, Adam M.; Rivera Bueno, Franklin; Kaye, Alan D.

2012-01-01

306

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

307

Abnormal dermatoglyphics in absence of thumb.  

PubMed

Dermatoglyphics of six patients with absence of thumb are described. Two specific abnormal configurations were seen in the palmar area. In the first, there was no axial triradius and the course of the ridges in the proximal part of the palm was transversal. In the second, a peculiar distal loop on the radial border was present with a palmar triradius. These abnormal patterns are probably due to the absence of a thenar volar pad or the presence of an abnormal one when the ridges are formed. PMID:7170953

Borbolla, L

1982-01-01

308

Thermoluminescence kinetics for multipeak glow curves produced by the release of electrons This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

Thermoluminescence kinetics for multipeak glow curves produced by the release of electrons-1334. Printed in Great Britain Thermoluminescence kinetics for multipeak glow curves produced by the releaseof applicationsof the model are briefly discussed. 1. Introduction A knowledge of thermoluminescence(TL) kinetics

Chen, Reuven

309

Four families with immunodeficiency and chromosome abnormalities.  

PubMed Central

Six children, with severe deficiency of some or all of the immunoglobulins and minor somatic abnormalities, had chromosomal abnormalities: (1) 45,XY,t(13q/18q), (2) 46,XY,21ps +, (3) two brothers 46,XY (inv. 7) (4) 45,X,t(11p/10p)/46X,iXq,t(11p/10p) and, (5) in addendum, 45,XX,-18;46,XX, r18. The chromosome abnormalities were detected in B- as well as T-lymphocytes (as evidenced by using both PHA- and PWM-stimulated cultures) in all probands, but one was mosaic in PHA culture, although all his PWM-stimulated cells were abnormal. Chromosomal variants were also detected in relatives of three and immunodeficiency in relatives of two. Images Fig. 1 Fig. 3 PMID:314782

Candy, D C; Hayward, A R; Hughes, D T; Layward, L; Soothill, J F

1979-01-01

310

ICSN Data - Abnormal Result Technologies and Procedures  

Cancer.gov

Skip to Main Content Search International Cancer Screening Network Sponsored by the National Cancer Institute Home | About ICSN | Collaborative Projects | Meetings | Cancer Sites | Publications | Contact Us Breast Cancer (Archived Tables): Home Abnormal

311

Abnormal Position and Presentation of the Fetus  

MedlinePLUS

... Sections Symptoms Multimedia Table Index In This Topic Women's Health Issues Complications of Labor and Delivery Abnormal Position ... Older People's Health Issues Skin Disorders Special Subjects Women's Health Issues Chapters in Women's Health Issues Biology of ...

312

Lens aplasia: a new mutation producing lens abnormality in the mouse.  

PubMed

One female with bilaterally closed eyelids was observed in a breeding colony of BALB/c mice in our laboratories. This eye abnormality was considered to be heritable because offspring with the same abnormality were produced from the mating of this female with a normal male littermate. From the results of various crosses made to determine the mode of inheritance, this abnormality is considered to be attributable to a mutation on a single autosomal recessive gene. Histologic observations of 30-day-old and adult mutant mice revealed various eye abnormalities such as microphthalmia, aphakia, absence of the anterior chamber, dystrophy of the cornea and vitreous body, and retinal disorganization. Observations of fetal eye development from days 9 to 17 of gestation, indicated that the eye developed normally until the start of invagination of the lens placode at day 10. However, formation of the lens vesicle progressed abnormally to form a mass of cells without a cavity at day 11; this mass was reduced in size at day 12 and had vanished by day 13 or 14 of gestation. Also abnormal development was observed in the cornea, vitreous body, or retina after day 12 of gestation. Complementary mating between mice homozygous for this mutation and homozygous aphakia mice, which have similar modes of inheritance and lens development, produced no F1 newborns with abnormal eyes. From these results, the present mutation is considered to be a new one. Because lens development in this mutant is disrupted at an early stage and the anlage vanishes soon after, we propose the name lens aplasia, with the suggested symbol "lap."(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7752613

Aso, S; Horiwaki, S; Noda, S

1995-02-01

313

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

314

Atmospheric Pressure Glow Discharge Plasma and Surface Modification of PET Textile by APGDP  

NASA Astrophysics Data System (ADS)

Comparing with traditional chemistry method, surface modification of Polyethylene terephthalate (PET) fabrics by using of Atmospheric Pressure Glow Discharge Plasma (APGDP) has many advantages, such as low cost, low pollution and low energy consumption. So it has huge application in textile industry due to no requirement for vacuum system. In this paper, the generation and the characteristics of APGDP on a homemade device were investigated experimentally. The volt-ampere characteristic and the Lissajous figure demonstrated that, different from dielectric barrier discharge (DBD), there is no filaments appeared between electrodes. It is a glow discharge in one atmospheric pressure. Furthermore we investigated the surface modification of PET by APGDP. The relationship between PET characteristics (wettability, critical surface tension, timing-effect, dyeablity etc.) and various discharge parameters are discussed. At last, the measurements of ATR-FTIR (Attenuated Total Refraction-Fourier Transform Infarared Spectroscopy) and dyeing properties are demonstrated, and the mechanism of modification is analyzed basically. Key words: APGDP£¬Surface modification , PET

Gu, Biao; Chen, Ru; Xu, Yin; Deng, Xiang; Shi, Qingjun

2002-11-01

315

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

316

Growth of tungsten nanoparticles in direct-current argon glow discharges  

SciTech Connect

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 {approx}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 {approx}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.; Coueedel, L.; Arnas, C. [Laboratoire de Physique des Interactions Ioniques et Moleculaires, CNRS-Aix-Marseille Universite, 13397 Marseille (France)

2013-04-15

317

PRODUCTION OF HIGHER STRENGTH THIN WALLED GLOW DISCHARGE POLYMER SHELLS FOR CRYOGENIC EXPERIMENTS AT OMEGA  

SciTech Connect

OAK A271 PRODUCTION OF HIGHER STRENGTH THIN WALLED GLOW DISCHARGE POLYMER SHELLS FOR CRYOGENIC EXPERIMENTS AT OMEGA. Thin walled polymer shells are needed for OMEGA cryogenic laser experiments. These capsules need to be about 900 {micro}m in diameter and as thin as possible (approx 1-2 {micro}m), while having enough strength to be filled with DT as fast as possible to about 1000 atm. The authors have found that by optimizing the coating parameters in the glow discharge polymer (GDP) deposition system, traditionally used for making ICF targets, they can routinely make robust, {approx} 1.5 {micro}m thick, 900 {micro}m diameter GDP shells with buckle strengths of over 0.3 atm. This is twice the strength of shells made prior to the optimization and is comparable to values quoted for polyimide shells. In addition, these shells were found to be approximately three times more permeable and over 20% denser than previously made GDP shells. The combination of higher strength and permeability is ideal for direct drive cryogenic targets at OMEGA. Shells as thin as 0.5 {micro}m have been made. In this paper, the authors discuss the shell fabrication process, effects of modifying various GDP deposition parameters on shell properties and chemical composition.

NIKROO,A; CZECHOWICZ,DG; CASTILLO,ER; PONTELANDOLFO,JM

2002-04-01

318

High-purity intense lithium-ion-beam sources using glow-discharge cleaning techniques  

SciTech Connect

High purity, 1 MV, 50 ns, 300 A/cm[sup 2] lithium beams have been produced using an extraction diode driven by Cornell's Light Ion Accelerator. Both passive and active anodes were studied with the highest-purity beams being generated by active anodes. These anodes were approximately 200 cm[sup 2] in area and consisted of 0.1 [mu]m films of Al and LiF evaporated onto a glass substrate. The anode plasma was formed by using a plasma opening switch to divert 50 kA from the main power pulse through the Al foil for 20 ns. Without glow-discharge cleaning, the ion beam produced by the LiF Al anode was over 55% hydrogen and only 20% Li[sup +]. In order to remove impurities, especially the hydrogen, the anodes were cleaned with a 110 mA, 33 W, 60 Hz glow discharge. The stoichiometry of the ion beam after discharge cleaning was 65% Li[sup +], 20% Al[sup +2], and 15% H[sup +]. The results are presented and a model of the cleaning mechanism is discussed.

Struckman, C.K.; Kusse, B.R. (Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States))

1993-09-15

319

Radio-frequency powered glow discharge device and method with high voltage interface  

DOEpatents

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)

1994-01-01

320

Radio-frequency powered glow discharge device and method with high voltage interface  

DOEpatents

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

1994-06-28

321

Influence of the transverse dimension on the structure and properties of dc glow discharges  

SciTech Connect

Two-dimensional (2D) simulations of a dc glow discharge with a cold cathode in argon have been performed for various radii of the discharge tube. It is shown that the loss of the charged particles to the walls can significantly affect plasma parameters as well as properties of the cathode sheath. The longitude dimensions of the negative glow and Faraday dark space depend on the transverse loss of the charge particles and are not consistently predicted with a 1D model. The common assumption that the cathode sheath can be analyzed independently of the plasma also may not be valid. The transverse inhomogeneity of the plasma leads to a change in the current density distribution over the cathode surface. The thickness of the cathode sheath can vary with radial distance from the discharge axis, even for the case of negligible radial loss of the charge particles. The 2D model results provide an analysis of the conditions of applicability of the 1D model.

Bogdanov, E. A. [St. Petersburg State University, St. Petersburg 198904 (Russian Federation); Adams, S. F. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Demidov, V. I. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Kudryavtsev, A. A. [Department of Optics, St. Petersburg State University, St. Petersburg 198904 (Russian Federation); Williamson, J. M. [UES, Inc., 4401 Dayton-Xenia Rd., Beavercreek, Ohio 45432 (United States)

2010-10-15

322

Glow Discharge-Tracer Technique for Velocity Profile Measurement in Hypersonic Boundary Layer Flows  

NASA Astrophysics Data System (ADS)

Spark-tracer technique using glow discharge is presented to measure velocity profiles across boundary layers around models in hypersonic flows. At first, a high voltage and high frequency discharge circuit and a discharge electrodes system used in the measurement are described. Next, to demonstrate the capability of the technique, the measurement of a velocity profile across a flat plate boundary layer is performed. The experimental result agrees well with the computational one based on the Navier-Stokes equations. Moreover, to clarify characteristics of the high frequency glow discharge generated in hypersonic flows, discharge gap voltage and current measurement is carried out and the follows are concluded. A positive column region is used as a tracer in the technique. Its characteristics are affected by retained ions in the column and also by the column length. Finally, from the fact that the experimental and numerical velocity profiles agree well, we may conclude that 1mJ of electric energy which is released in an impulsive discharge does not disturb the flow.

Itoh, Hajime

323

Thermoluminescence in pure LiF crystals: Glow peaks and their connection with color centers  

SciTech Connect

Nominally pure LiF crystals were irradiated with the same dose (0.85 10{sup 6} R) of gamma rays at ambient and low temperatures (-60 deg. C) and the resulting thermoluminescence (TL) is reported. Various optical and thermal treatments were applied in order to change the concentration of color centers (CCs). The effect of such treatments on the glow curves is observed. Knowing the coloration from optical transmission and photoluminescence measurements made on the same samples, we attribute many of the glow peaks (GPs) to the annealing of F center aggregates. For the present conditions of irradiation and dose, TL processes begin with decay of F{sub 3}{sup +} centers that display a GP at 164 deg. C. F{sub 3}(R) centers follow and are responsible for GPs at 193 and 228 deg. C. A GP at 263 deg. C is ascribed to F{sub 2} centers. Several peaks at temperatures in the range of 280-380 deg. C are associated with impurity perturbed F centers. A GP at 410 deg. C is associated with a complex of aggregated F and H centers. These attributions are accomplished by means of TL spectra, optical transmission spectra, and annealing procedures, and are critically discussed. The experimental data confirm the general trend of thermal stability of CCs, which decreases by moving from simple F centers to more complex ones, and the existence of exchange dynamics among CCs.

Baldacchini, G.; Montereali, R. M. [Department of Physical Technologies and New Materials-Frascati Research Center, ENEA, Via E. Fermi 45, Frascati, Roma 00044 (Italy); Nichelatti, E. [Department of Physical Technologies and New Materials-Casaccia Research Center, ENEA, S. Maria di Galeria, Roma 00123 (Italy); Kalinov, V. S.; Voitovich, A. P. [Institute of Physics, Academy of Sciences of Belarus, 70 Nezavisimosti Ave., 220067 Minsk (Belarus); Davidson, A. T.; Kozakiewicz, A. G. [Department of Chemistry, University of Zululand, Kwadlangezwa 3886 (South Africa)

2008-09-15

324

Thermoluminescence in pure LiF crystals: Glow peaks and their connection with color centers  

NASA Astrophysics Data System (ADS)

Nominally pure LiF crystals were irradiated with the same dose (0.85 106 R) of gamma rays at ambient and low temperatures (-60 °C) and the resulting thermoluminescence (TL) is reported. Various optical and thermal treatments were applied in order to change the concentration of color centers (CCs). The effect of such treatments on the glow curves is observed. Knowing the coloration from optical transmission and photoluminescence measurements made on the same samples, we attribute many of the glow peaks (GPs) to the annealing of F center aggregates. For the present conditions of irradiation and dose, TL processes begin with decay of F3+ centers that display a GP at 164 °C. F3(R) centers follow and are responsible for GPs at 193 and 228 °C. A GP at 263 °C is ascribed to F2 centers. Several peaks at temperatures in the range of 280-380 °C are associated with impurity perturbed F centers. A GP at 410 °C is associated with a complex of aggregated F and H centers. These attributions are accomplished by means of TL spectra, optical transmission spectra, and annealing procedures, and are critically discussed. The experimental data confirm the general trend of thermal stability of CCs, which decreases by moving from simple F centers to more complex ones, and the existence of exchange dynamics among CCs.

Baldacchini, G.; Montereali, R. M.; Nichelatti, E.; Kalinov, V. S.; Voitovich, A. P.; Davidson, A. T.; Kozakiewicz, A. G.

2008-09-01

325

The effect of pre-irradiation annealing on TL glow curves of LiF (Mg)  

NASA Astrophysics Data System (ADS)

The practice of pre-annealing dosimeter crystals before irradiation is examined in this investigation. LiF crystals with high (2000 ppm) and low (100 ppm) concentrations of Mg impurities are investigated using optical absorption (OA), photoluminescence (PL) and thermoluminescence (TL) techniques. Pre-annealing was at 400°C for 1 h and irradiations were with ?-rays from an Am241 source in the dose range 0.6-8.0 kGy. In 2000 ppm samples pre-annealing produces noticeable effects at low doses, namely enhanced optical absorption at 310 nm compared with untreated crystals but reduced intensity in the glow curves. At higher doses, the glow curves are similar but pre-annealed samples have a significantly smaller TL response. Pre-annealing 100 ppm samples produces smaller changes. Some implications for thermoluminescences are considered. The present results can be explained by considering the effects of pre-irradiation annealing on the distribution of Mg which acts as a trapping centre for interstitial fluorine atoms.

Kozakiewicz, A. G.; Davidson, A. T.; Wilkinson, D. J.

2000-05-01

326

Characterization of a glow discharge ion source for the mass spectrometric analysis of organic compounds.  

PubMed

A glow discharge ion source has been constructed for the mass spectrometric analysis of organic compounds. Characterization of the source has been made by studying the effect of pressure and discharge current on ionic distributions by anodic ion sampling along the discharge axis. Ion and electron densities and electronic temperatures have been calculated by using the single Langmuir probe technique to correlate the extraction efficiency with measured ion distributions and gain some insight into the ionization of organic molecules. The spectra obtained for several classes of organic compounds show that formation of parent-molecular ions by proton transfer, resulting partly from the background water molecules, is a major low energy process while charge transfer, Penning ionization, and electron ionization ace probably responsible for the fragmentation observed. The spectra result from the simultaneous occurrence of high and low energy reactions, and their structural information content is very high, yielding both molecular and extensive fragment ion information. The glow discharge ion source has proved to be essentially maintenance-free, easy to operate, stable, and can be used at reasonable mass resolution (up to 70001. The source also provides picogram range detection limits and has a linear response range of about six orders of magnitude, which makes it an interesting ion source for routine analysis. Preliminary work conducted with chromatographic interfaces indicates that its use can be easily extended to both gas and liquid chromatography. PMID:24222568

Carazzato, D; Bertrand, M J

1994-04-01

327

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

328

42 CFR 37.54 - Notification of abnormal radiographic findings.  

...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...

2014-10-01

329

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

330

Abnormal brain connectivity in schizophrenia : investigations into episodic memory networks.  

E-print Network

??Abnormal connectivity between the prefrontal cortex (PFC) and other brain regions has been demonstrated in subjects with schizophrenia. We tested if abnormal connectivity, particularly between… (more)

Pelletier, Marc, 1973-

2005-01-01

331

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

332

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

333

Glow Up  

NSDL National Science Digital Library

In this activity, learners explore chemiluminescence and fluorescence. Learners examine 3 different solutions in regular light, in the dark with added bleach solution, and under a black light. This resource includes information about chemiluminescence and fluorescence including how these properties pertain to molecular and cell biology.

Yu, Julie

2008-01-01

334

They Glow!  

NSDL National Science Digital Library

This fun web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, kids learn about bioluminescence. The article contains two engaging, kid-friendly sections. One, a sing-along animated explanation that looks at how marine animals use bioluminescence and the other a quick look at how lantern fish and flashlight fish use bioluminescence to protect themselves against predators.

335

LONG-TERM MONITORING OF MODE SWITCHING FOR PSR B0329+54  

SciTech Connect

The mode-switching phenomenon of PSR B0329+54 is investigated based on the long-term monitoring from 2003 September to 2009 April made with the Urumqi 25 m radio telescope at 1540 MHz. At that frequency, the change of relative intensity between the leading and trailing components is the predominant feature of mode switching. The intensity ratios between the leading and trailing components are measured for the individual profiles averaged over a few minutes. It is found that the ratios follow normal distributions, where the abnormal mode has a greater typical width than the normal mode, indicating that the abnormal mode is less stable than the normal mode. Our data show that 84.9% of the time for PSR B0329+54 was in the normal mode and 15.1% was in the abnormal mode. From the two passages of eight-day quasi-continuous observations in 2004, supplemented by the daily data observed with the 15 m telescope at 610 MHz at Jodrell Bank Observatory, the intrinsic distributions of mode timescales are constrained with the Bayesian inference method. It is found that the gamma distribution with the shape parameter slightly smaller than 1 is favored over the normal, log-normal, and Pareto distributions. The optimal scale parameters of the gamma distribution are 31.5 minutes for the abnormal mode and 154 minutes for the normal mode. The shape parameters have very similar values, i.e., 0.75{sup +0.22}{sub -0.17} for the normal mode and 0.84{sup +0.28}{sub -0.22} for the abnormal mode, indicating that the physical mechanisms in both modes may be the same. No long-term modulation of the relative intensity ratios was found for either mode, suggesting that the mode switching was stable. The intrinsic timescale distributions, constrained for this pulsar for the first time, provide valuable information to understand the physics of mode switching.

Chen, J. L.; Wang, N.; Liu, Z. Y.; Yuan, J. P. [Xinjiang Astronomical Observatory, 150, Science-1 Street, Urumqi, Xinjiang, 830011 (China); Wang, H. G. [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China); Lyne, A. [University of Manchester, Jodrell Bank (United Kingdom); Jessner, A.; Kramer, M., E-mail: hgwang@gzhu.edu.cn [Max-Planck Institute for Radio Astronomy, Bonn 53121 (Germany)

2011-11-01

336

Development of ac corona discharge modes at atmospheric pressure  

NASA Astrophysics Data System (ADS)

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

2011-02-01

337

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

338

The effects of moon illumination, moon angle, cloud cover, and sky glow on night vision goggle flight performance  

NASA Astrophysics Data System (ADS)

This study was designed to examine moon illumination, moon angle, cloud cover, sky glow, and Night Vision Goggle (NVG) flight performance to determine possible effects. The research was a causal-comparative design. The sample consisted of 194 Fort Rucker Initial Entry Rotary Wing NVG flight students being observed by 69 NVG Instructor Pilots. The students participated in NVG flight training from September 1992 through January 1993. Data were collected using a questionnaire. Observations were analyzed using a Kruskal-Wallis one-way analysis of variance and a Wilcox matched pairs signed-ranks test for difference. Correlations were analyzed using Pearson's r. The analyses results indicated that performance at high moon illumination levels is superior to zero moon illumination, and in most task maneuvers, superior to >0%--50% moon illumination. No differences were found in performance at moon illumination levels above 50%. Moon angle had no effect on night vision goggle flight performance. Cloud cover and sky glow have selective effects on different maneuvers. For most task maneuvers, cloud cover does not affect performance. Overcast cloud cover had a significant effect on seven of the 14 task maneuvers. Sky glow did not affect eight out of 14 task maneuvers at any level of sky glow.

Loro, Stephen Lee

339

Monte Carlo analysis of the electron thermalization process in the afterglow of a microsecond dc pulsed glow discharge  

Microsoft Academic Search

A Monte Carlo model is utilized for studying the behavior of electrons in the afterglow of an analytical microsecond dc pulsed glow discharge. This model uses several quantities as input data, such as electric field and potential, ion flux at the cathode, the fast argon ion and atom impact ionization rates, slow electron density, the electrical characterization of the pulse

A. Martin; N. Bordel; R. Pereiro; A. Bogaerts

2008-01-01

340

'Ebony Embers', 'Ebony Fire', 'Ebony Flame','Ebony Glow' and 'Ebony and Ivory' Dark-Leaf Crapemyrtles  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Ebony Embers’, ‘Ebony Fire’, ‘Ebony Flame’, ‘Ebony Glow’ and ‘Ebony and Ivory’ are cultivars which are predominantly L. indica in heritage that combine persistent black-purple leaves and a range of flower colors with intermediate growth habits. ‘Ebony Embers’ has a vase shaped growth habit with dim...

341

Novel mm-wave and THz radiation active imaging system based on glow discharge detector (GDD) pixel  

Microsoft Academic Search

A novel imaging system for mm wavelength and THz radiation is presented in this paper. The imaging system is based upon an inexpensive neon indicator lamp or glow discharge detector (GDD) that serves as a pixel in a focal plane array (FPA). It was shown in previous investigations that inexpensive neon indicator lamp GDDs are quite sensitive to mm wavelength

N. S. Kopeika; A. Abramovich; D. Rozban

2008-01-01

342

Ergastoplasmic paracrystalline inclusion bodies in the adipose gonadal envelope and fat body of the glow worm, Lampyris noctiluca (Insecta, Coleoptera)  

Microsoft Academic Search

The gonads of glow worm larvae are enveloped by adipose tissue which represents a specialized fat body. The adipose gonadal envelope, and also to a lesser extent the fat body cells, contain tubular paracrystalline inclusion bodies (PIBs). Cells of other tissues are devoid of such inclusions. The PIBs form in the cisternae of rough ER. In young larvae PIB formation

U. Maas; E. Sehn; J. R. Harris; A. Dorn

2001-01-01

343

An enzyme histochemical and electron microscopical study of the light organ of the glow-worm, Lampyris noctiluca  

Microsoft Academic Search

Summary The light organs of female specimens of the glow-worm Lampyris noctiluca were investigated by enzyme histochemical tests, lipid stains, and electron microscopy. Differences, both histochemical and in fine structure, were found between the cells of the photocyte and reflector layers. The photocytes contained a vesiculated reticulum, photocyte granules, amorphous granules, and numerous mitochondria. The reflectcr layer did not contain

V. C. BARBER; C. W. T. PILCHER

1965-01-01

344

Infrared and Raman spectra of the silicon-hydrogen bonds in amorphous silicon prepared by glow discharge and sputtering  

Microsoft Academic Search

We have studied the number and nature of the silicon-hydrogen bonds in amorphous silicon films prepared in plasmas either of silane or of hydrogen and argon. The films from silane glow discharges have qualitatively different Raman and infrared spectra which depend on deposition parameters such as substrate temperature and silane gas pressure. Three main groups of spectral bands are seen

M. H. Brodsky; Manuel Cardona; J. J. Cuomo

1977-01-01

345

Abnormal hepatocellular mitochondria in methylmalonic acidemia.  

PubMed

Methylmalonic acidemia (MMA) is one of the most frequently encountered forms of branched-chain organic acidemias. Biochemical abnormalities seen in some MMA patients, such as lactic acidemia and increased tricarboxylic acid cycle intermediate excretion, suggest mitochondrial dysfunction. In order to investigate the possibility of mitochondrial involvement in MMA, we examined liver tissue for evidence of mitochondrial ultrastructural abnormalities. Five explanted livers obtained from MMA mut(0) patients undergoing liver transplantation were biopsied. All patients had previous episodes of metabolic acidosis, lactic acidemia, ketonuria, and hyperammonemia. All biopsies revealed a striking mitochondriopathy by electron microscopy. Mitochondria were markedly variable in size, shape, and conformation of cristae. The inner matrix appeared to be greatly expanded and the cristae were diminutive and disconnected. No crystalloid inclusions were noted. This series clearly documents extensive mitochondrial ultrastructure abnormalities in liver samples from MMA patients undergoing transplantation, providing pathological evidence for mitochondrial dysfunction in the pathophysiology of MMA mut(0). Considering the trend to abnormally large mitochondria, the metabolic effects of MMA may restrict mitochondrial fission or promote fusion. The correlation between mitochondrial dysfunction and morphological abnormalities in MMA may provide insights for better understanding and monitoring of optimized or novel therapeutic strategies. PMID:24933007

Wilnai, Yael; Enns, Gregory M; Niemi, Anna-Kaisa; Higgins, John; Vogel, Hannes

2014-10-01

346

The back-diffusion effect of air on the discharge characteristics of atmospheric-pressure radio-frequency glow discharges using bare metal electrodes  

NASA Astrophysics Data System (ADS)

Radio-frequency (RF), atmospheric-pressure glow discharge (APGD) plasmas using bare metal electrodes have promising prospects in the fields of plasma-aided etching, deposition, surface treatment, disinfection, sterilization, etc. In this paper, the discharge characteristics, including the breakdown voltage and the discharge voltage for sustaining a stable and uniform ? mode discharge of the RF APGD plasmas are presented. The experiments are conducted by placing the home-made planar-type plasma generator in ambient and in a vacuum chamber, respectively, with helium as the primary plasma-forming gas. When the discharge processes occur in ambient, particularly for the lower plasma-working gas flow rates, the experimental measurements show that it is the back-diffusion effect of air in atmosphere, instead of the flow rate of the gas, that results in the obvious decrease in the breakdown voltage with increasing plasma-working gas flow rate. Further studies on the discharge characteristics, e.g. the luminous structures, the concentrations and distributions of chemically active species in plasmas, with different plasma-working gases or gas mixtures need to be conducted in future work.

Sun, Wen-Ting; Liang, Tian-Ran; Wang, Hua-Bo; Li, He-Ping; Bao, Cheng-Yu

2007-05-01

347

First operation of 8×8 glow discharge detector VLSI focal plane array toward mm wave and THz radiation video rate imaging  

NASA Astrophysics Data System (ADS)

A new kind of 8×8 focal plane array (FPA) based on glow discharge detector (GDD) elements was constructed and tested experimentally. First THz images of this FPA are presented. The data acquisition of this system is performed with a special VLSI board designed for this system. Previously, signal detection of the FPA elements was based upon a lock in amplifier (LIA) which limited the rate of image formation. This was in order to detect weak signals required for stand-off remote detection. Switching mode is necessary in order to save energy but stabilization time of the GDD found to be 0.5 sec. Recent investigations proved that it is possible to overcome the above timing limitations. It was shown that heterodyne detection yielded 40 times more sensitivity than the direct detection, thus in many circumstances obviating the need for a LIA. Moreover, GDD stabilization time of less than 1 msec was achieved. These developments should enable video rate THz imaging using GDD FPAs.

Kopeika, N. S.; Abramovich, A.; Joseph, H.; Akram, A.; Yadid-Pecht, O.; Belenky, A.; Lineykin, S.

2009-09-01

348

Study of Energetic and Temporal Characteristics of X-Ray Emission from Solid-State Cathode Medium of High-Current Glow Discharge  

NASA Astrophysics Data System (ADS)

Experimental results on X-ray emission characteristics from the cathode material in the high-current Glow Discharge (GD) are presented. The X-ray emission ranging 0.6-6.0 keV and more with the dose rate up to 0.01 J/s has been registered. Two emission modes were obtained in the experiments: (1) diffusion X-rays were observed as separate X-ray bursts (up to 5 × 105 bursts a second and up to 106 X-ray quanta in a burst); (2) X-rays in the form of laser micro-beams were registered (up to 104 beams per second and up to 1010 X-ray of quanta in a beam, angular divergence being up to 10-4, the duration of separate laser beam about ? = 3 × 10-13-3 × 10-14 s, the estimated separate beam power of 107-108 W). The emission of the X-ray laser beams occurred during the GD operation, and, after the GD current switch off.

Karabut, A. B.

349

Endocrine abnormalities in Townes-Brocks syndrome.  

PubMed

Townes-Brocks syndrome is a recognizable variable pattern of malformation caused by mutations to the SALL1 gene located on chromosome 16q12.1. Only three known cases of Townes-Brocks syndrome with proven SALL1 gene mutation and concurrent endocrine abnormalities have been previously documented to our knowledge [Kohlhase et al., 1999; Botzenhart et al., 2005; Choi et al., 2010]. We report on two unrelated patients with Townes-Brocks syndrome who share an identical SALL1 mutation (c.3414_3415delAT), who also have endocrine abnormalities. Patient 1 appears to be the first known case of growth hormone deficiency, and Patient 2 extends the number of documented mutation cases with hypothyroidism to four. We suspect endocrine abnormalities, particularly treatable deficiencies, may be an underappreciated component to Townes-Brocks syndrome. PMID:23894113

Lawrence, Cara; Hong-McAtee, Irene; Hall, Bryan; Hartsfield, James; Rutherford, Andrew; Bonilla, Tracy; Bay, Carolyn

2013-09-01

350

Physicomathematical analysis of surface modification of polymers by glow discharge in SF6+N2 medium  

NASA Astrophysics Data System (ADS)

In this paper, surface modification of dielectric polymers, having different physical and chemical properties (polyimide-PI, polystyrene-PS, Polyethylene terephthalate-PET), treated in contourized glow discharge in SF6+N2 gas medium near cathode was studied. The electret state, formed as a result of modification, caused an increase in the surface energy. Surface charge densities and contact angles of dielectric polymers whose surfaces were activated under identical conditions, were measured. Upon activation, formation of electret state on the dielectrics strained the sessile drop and consequently the contact angle changed. A mathematical model relating the contact angle and the surface charge density was derived. Experimental results agreed well with the theoretical model.

Alisoy, H. Z.; Baysar, A.; Alisoy, G. T.

2005-06-01

351

Application of Glow Discharge Aes for Investigation of Metal Ions and Water in Biology and Medicine  

E-print Network

AES VHF inductively coupled plasmatron may be applied to wide range of studies. It enables rapid microanalysis of various solutions including biological objects and peripheral blood serum. In addition, it may be used for investigation of water desorption from solid bodies and for determination of energetic metal-macromolecule complexes. Study of hydration energy and hydration number by kinetic curves of water glow discharge atomic spectral analysis of hydrogen (GD EAS analysis of hydrogen) desorption from Na-DNA humidified fibers allowed to reveal that structural and conformational changes in activation energy of hydrated water molecules increases by 0.65kcal/Mole of water. The developed method of analysis of elements in solutions containing high concentrations of organic materials allows systematic study of practically healthy persons and reveals risk factors for several diseases. Microelemental content of blood serum fractions showed that amount of not bounded with ceruloplasmin copper was three times more ...

Bregadze, Vasil G; Tsakadze, Ketevan J

2007-01-01

352

Plasma sheath physics and dose uniformity in enhanced glow discharge plasma immersion ion implantation and deposition  

SciTech Connect

Based on the multiple-grid particle-in-cell code, an advanced simulation model is established to study the sheath physics and dose uniformity along the sample stage in order to provide the theoretical basis for further improvement of enhanced glow discharge plasma immersion ion implantation and deposition. At t=7.0 mus, the expansion of the sheath in the horizontal direction is hindered by the dielectric cage. The electron focusing effect is demonstrated by this model. Most of the ions at the inside wall of the cage are implanted into the edge of the sample stage and a relatively uniform ion fluence distribution with a large peak is observed at the end. Compared to the results obtained from the previous model, a higher implant fluence and larger area of uniformity are disclosed.

Li Liuhe; Li Jianhui [Department 702, School of Mechanical and Automation Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Kwok, Dixon T. K.; Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Wang Zhuo [Department 702, School of Mechanical and Automation Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China)

2009-07-01

353

Some properties of a microwave boosted glow discharge source using neon as the operating gas.  

PubMed

The use of neon as the operating gas for the analysis of aluminium samples with the microwave boosted glow discharge source has been studied. A new type of anode tube allowed the gas to enter the source near the sample surface so that more material was transported into the discharge. Erosion rates have been measured under conditions optimised for high line-to-background ratios and found to be lower than with argon (9 and 21 n/s, respectively). Despite the lower erosion rate the detection limits measured for a number of elements in aluminium are in the range 0.02-1 microg/g and comparable to those obtained with argon as the operating gas. PMID:15045284

Leis, F; Steers, E B

1996-07-01

354

A study of the glow discharge characteristics of contact electrodes at atmospheric pressure in air  

SciTech Connect

Electric field distributions and discharge properties of rod-rod contact electrodes were studied under the condition of DBD for the steady generation of atmospheric pressure glow discharge plasma (APGD) in air. We found that under the effect of the initial electrons generated in a nanometer-scale gap, the rod-rod cross-contact electrodes yielded APGD plasma in air. Regarding the rod-rod cross-contact electrodes, increasing the working voltage expanded the strong electric field area of the gas gap so that both discharge area and discharge power increased, and the increase in the number of contact points kept the initial discharge voltage unchanged and caused an increase in the plasma discharge area and discharge power. A mesh-like structure of cross-contact electrodes was designed and used to generate more APGD plasma, suggesting high applicability.

Liu, Wenzheng, E-mail: wzhliu@bjtu.edu.cn; Sun, Guangliang, E-mail: 11121659@bjtu.edu.cn; Li, Chuanhui; Zhang, Rongrong [School of Electrical Engineering, Beijing Jiaotong University, Beijing 100044 (China)] [School of Electrical Engineering, Beijing Jiaotong University, Beijing 100044 (China)

2014-04-15

355

Fourier transform atomic emission studies using a glow discharge as the emission source  

NASA Astrophysics Data System (ADS)

The glow discharge (GD) is investigated as a possible atomic emission source for Fourier transform atomic emission spectroscopy (FT-AES). Noise power spectra are presented to demonstrate that GD emission is primarily characterized by photon noise, although a drift noise component exists at extremely low frequencies. The photon noise character is important, since photon noise limited sources are expected to outperform source flicker noise limited sources in terms of measurement precision. The implementation of bandpass restriction and dual channel subtractive noise cancellation as possible means of improving measurement precision are also presented. In both cases, the improvements were found to be minimal, a fact attributed to the probable suitability of the GD for FT-AES.

Winchester, Michael R.; Travis, John C.; Salit, Marc L.

1993-09-01

356

Synthesis of Poly (Butyl Methacrylate/Butyl Acrylate) Highly Absorptive Resin Using Glow Discharge Electrolysis  

NASA Astrophysics Data System (ADS)

A highly absorptive resin poly (butyl methacrylate (BMA)-co-butyl acrylate (BA)) was prepared by emulsion polymerization, which was initiated by glow discharge electrolysis plasma (GDEP). The effects of discharge voltage, discharge time, monomer ratio and the amounts of cross-linking agent were examined and discussed in detail. The chemical structure of the obtained resin was characterized by means of attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The optimal conditions were obtained as: discharge voltage was 600 V, discharge time was 8 min, the ratios of BMA:BA being 2:1 for chloroform and 3:1 for xylene, with 2% N, N'-methylenebis. Under optimal conditions, the oil absorbency was 70 g/g for chloroform and 46 g/g for xylene. Moreover, the absorptive dynamical behavior of the resulting resin was also investigated.

Li, Yan; Yao, Mengqi; Liao, Ruirui; Yang, Wu; Gao, Jinzhang; Ren, Jie

2014-08-01

357

Dynamic contraction of the positive column of a self-sustained glow discharge in air flow  

SciTech Connect

We study the dynamic contraction of a self-sustained glow discharge in air in a rectangular duct with convective cooling. A two dimensional numerical model of the plasma contraction was developed in a cylindrical frame. The process is described by a set of time-dependent continuity equations for the electrons, positive and negative ions; gas and vibrational temperature; and equations which account for the convective heat and plasma losses by the transverse flux. Transition from the uniform to contracted state was analyzed. It was shown that such transition experiences a hysteresis, and that the critical current of the transition increases when the gas density drops. Possible coexistence of the contracted and uniform state of the plasma in the discharge, where the current flows along the density gradient of the background gas, is discussed.

Shneider, M. N. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)] [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Mokrov, M. S. [Institute for Problems in Mechanics, RAS, Moscow (Russian Federation)] [Institute for Problems in Mechanics, RAS, Moscow (Russian Federation); Milikh, G. M. [Department of Astronomy, University of Maryland, College Park, Maryland 20742 (United States)] [Department of Astronomy, University of Maryland, College Park, Maryland 20742 (United States)

2014-03-15

358

Developments in explosives vapor detection by glow discharge/ion trap MS  

SciTech Connect

The quadrupole ion trap has found great utility in the analytical community due to its high sensitivity and MS{sup n} capabilities. Problems associated with matrix ions filling ion traps have been addressed by mass-selective ion accumulation methods. The atmospheric sampling glow discharge ionization (ASGDI) source coupled to a quadrupole ion trap used for explosives detection is prone to matrix ion effects because of its large abundance of background ions at low mass. By using a mass selective ion accumulation method such as a filtered-noise field (FNF), matrix ions are ejected allowing for the analyte ions to be concentrated in the trap. This paper will report on the detection limits found for explosives on the ASGDI/Finnigan ITMS using the FNF technology and on initial studies on the performance of the ASGDI/Teledyne 3DQ.

Asano, K.; Vaidyanathan, G.; Goeringer, D.; McLuckey, S. [Oak Ridge National Lab., TN (United States)

1995-12-31

359

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

360

Synthesis of zinc oxide films in glow discharge of various configurations  

NASA Astrophysics Data System (ADS)

The structure of zinc oxide (ZnO) films deposited on silicon substrates using dc glow discharge in oxygen have been studied for two electrode configurations—with tubular (hollow) and planar cathodes. At a substrate temperature of 670 K and oxygen pressure of 0.5 Torr, ZnO films synthesized in the hollow cathode geometry possess a columnar structure, while those obtained in the planar geometry are continuous. A decrease in the oxygen pressure from 0.5 to 0.2 Torr in discharge with the hollow cathode geometry leads to a change from a columnar to continuous film structure, while the morphology of films obtained in the planar geometry remains unchanged. The synthesized films exhibit a high degree of crystallographic orientation [001]ZnO ? [001]Si with complete azimuthal disorientation in the plane of film conjugation with the substrate.

Zinchenko, S. P.; Lyanguzov, N. V.; Zakharchenko, I. N.; Ratushnyi, V. I.; Shirokov, V. B.

2014-11-01

361

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

362

Structural analysis of nitride layer formed on uranium metal by glow plasma surface nitriding  

NASA Astrophysics Data System (ADS)

The nitride layer was formed on uranium metal by a glow plasma surface nitriding method. The structure and composition of the layer were investigated by X-ray diffraction and Auger electron spectroscopy. The nitride layer mainly consisted of ?-phase U2N3 nanocrystals with an average grain size about 10-20 nm. Four zones were identified in the layer, which were the oxide surface zone, the nitride mainstay zone, the oxide-existence interface zone, and the nitrogen-diffusion matrix zone. The gradual decrease of binding energies of uranium revealed the transition from oxide to nitride to metal states with the layer depth, while the chemical states of nitrogen and oxygen showed small variation.

Liu, Kezhao; Bin, Ren; Xiao, Hong; Long, Zhong; Hong, Zhanglian; Yang, Hui; Wu, Sheng

2013-01-01

363

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

364

Thermally stimulated glow peaks in Ge-doped cultured quartz crystals and their radiation response  

SciTech Connect

Ge-doped crystalline quartz has been examined for its thermally stimulated luminescence and has been found to exhibit TL-glow peaks at 100, 200, and 310 degree sign C. While the peaks at 100 and 310 degree sign C have already been noticed in conventionally grown quartz, the new peak at 200 degree sign C, observed in the present studies, appears to be due to the presence of Ge in quartz lattice. The radiation dependence of this peak upon irradiation at 300 K by high energy electrons (1.75 MeV) has been presented and the results have been compared and discussed in terms of the hydroxyl defects in natural, cultured, and Ge-doped cultured quartz.

Bahadur, Harish [National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-110012 (India)

2007-02-01

365

Design and construction of uniform glow discharge plasma system operating under atmospheric condition  

SciTech Connect

The design of a uniform glow discharge plasma system operating without vacuum is presented. A full-bridge switching circuit was used to switch the transformers. The primary windings of transformers were connected in parallel, but in opposite phase to double the output voltage. Theoretically, 20 000 V{sub pp} was obtained. Rectangle copper electrodes were used, and placed parallel to each other. To prevent the spark production that is, to obtain uniformity, two 2 mm Teflon sheets were glued to the electrodes. However, it was observed that the operating frequency also affected the uniformity. For the system presented here, the frequency at which more uniformity was obtained was found to be 14 kHz.

Kocum, C.; Ayhan, H. [Biomedical Engineering Department, Baskent University, Ankara 06530 (Turkey); Chemistry Department, Biochemistry Division, Mugla University, Faculty of Science, Koetekli, 48170 Mugla (Turkey)

2007-06-15

366

Non-local Effects in a Stratified Glow Discharge With Dusty Particles  

SciTech Connect

The work is aimed to describe non-local effects in the positive column of a low pressure stratified DC glow discharge in argon with dusty particles in a vertical cylindrical discharge tube. The numerical calculations of plasma parameters in the axis of the discharge tube were performed with the help of hybrid model based on the solution of non-local Boltzmann equation for EEDF. Distributions of optical emission from striations were measured experimentally. It is shown that in a stratified positive column the EEDF is not Maxwellian and even non-monotonous. Also, the effect of displacing of optical emission distribution relative to the electric field is shown both by numerical simulation and experimental measurements.

Sukhinin, G. I. [Institute of Thermophysics SB RAS, Lavrentyev Ave., 1, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Pirogova Str., 2, Novosibirsk, 630090 (Russian Federation); Fedoseev, A. V. [Institute of Thermophysics SB RAS, Lavrentyev Ave., 1, Novosibirsk, 630090 (Russian Federation); Ramazanov, T. S.; Amangaliyeva, R. Zh.; Dosbolayev, M. K.; Jumabekov, A. N. [Institute of Experimental and Theoretical Physics, Al Farabi Kazakh National University, Tole Bi, 96a, Almaty, 050012 (Kazakhstan)

2008-09-07

367

Measurements and models of transient and stationary regimes of glow discharge in argon  

NASA Astrophysics Data System (ADS)

The experimental and theoretical analyses of different regimes of argon DC glow discharge are reported. The experiments were carried out on the argon gas tube with a plane- parallel electrode system made from OFHC (oxygen-free high thermal conductivity) copper. Modelling of the static breakdown voltages was performed by simple fluid model. The applicability of fluid models for modelling of I - U (current-voltage) characteristics at different values of pd (pressure times inter-electrode distance) is tested. The formative time delays are determined from experiment and compared to modeled values obtained by [1D] and [2D] fluid models. The memory curve bar td (?) (the dependence of the mean value of breakdown time delay on the relaxation time) is presented and the main processes responsible for the memory effect were determined by applying the analytical and numerical models.

Stankov, M. N.

2014-12-01

368

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

369

Abnormal Selective Attention Normalizes P3 Amplitudes in PDD  

ERIC Educational Resources Information Center

This paper studied whether abnormal P3 amplitudes in PDD are a corollary of abnormalities in ERP components related to selective attention in visual and auditory tasks. Furthermore, this study sought to clarify possible age differences in such abnormalities. Children with PDD showed smaller P3 amplitudes than controls, but no abnormalities in…

Hoeksma, Marco R.; Kemner, Chantal; Kenemans, J. Leon; van Engeland, Herman

2006-01-01

370

NASA Ames Research Center Emergency and Abnormal Situations in  

E-print Network

NASA Ames Research Center Emergency and Abnormal Situations in Aviation Symposium June 10 -11, 2003 San Jose, California "Dealing with Emergency/Abnormal Situations with New Security Guidelines" Captain MANAGEMENT Emergency/Abnormal SituationsEmergency/Abnormal Situations & Security& Security #12;Agenda

371

Disease-specific perception of fracture risk and incident fracture rates: GLOW cohort study  

PubMed Central

Purpose Accurate patient risk perception of adverse health events promotes greater autonomy over, and motivation towards, health-related lifestyles. We compared self-perceived fracture risk and 3-year incident fracture rates in postmenopausal women with a range of morbidities in the Global Longitudinal study of Osteoporosis in Women (GLOW). Methods GLOW is an international cohort study involving 723 physician practices across 10 countries (Europe, North America, Australasia). 60,393 women aged ?55 years completed baseline questionnaires detailing medical history and self-perceived fracture risk. Annual follow-up determined self-reported incident fractures. Results In total 2,945/43,832 (6.8%) sustained an incident fracture over 3 years. All morbidities were associated with increased fracture rates, particularly Parkinson’s disease (hazard ratio [HR]; 95% confidence interval [CI], 3.89; 2.78–5.44), multiple sclerosis (2.70; 1.90–3.83), cerebrovascular events (2.02; 1.67–2.46), and rheumatoid arthritis (2.15; 1.53–3.04) (all p<0.001). Most individuals perceived their fracture risk as similar to (46%) or lower than (36%) women of the same age. While increased self-perceived fracture risk was strongly associated with incident fracture rates, only 29% experiencing a fracture perceived their risk as increased. Under-appreciation of fracture risk occurred for all morbidities, including neurological disease, where women with low self-perceived fracture risk had a fracture HR 2.39 (CI 1.74–3.29) compared with women without morbidities. Conclusions Postmenopausal women with morbidities tend to under-appreciate their risk, including in the context of neurological diseases, where fracture rates were highest in this cohort. This has important implications for health education, particularly among women with Parkinson’s disease, multiple sclerosis, or cerebrovascular disease. PMID:23884437

Gregson, C. L.; Dennison, E. M.; Compston, J. E.; Adami, S.; Adachi, J. D.; Anderson, F. A.; Boonen, S.; Chapurlat, R.; Díez-Pérez, A.; Greenspan, S. L.; Hooven, F. H.; LaCroix, A. Z.; Nieves, J. W.; Netelenbos, J. C.; Pfeilschifter, J.; Rossini, M.; Roux, C.; Saag, K. G.; Silverman, S.; Siris, E. S.; Watts, N. B.; Wyman, A.; Cooper, C.

2013-01-01

372

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

373

PSY 350 Abnormal Psychology Spring 2008  

E-print Network

disorders, dissociative and somatoform disorders, mood disorders, substance abuse and dependence, eating of major behavior disorders. A sampling of the specific topics will include: stress and health, #12;anxiety disorders, gender and sexuality, psychotic disorders, personality disorders, abnormal behavior in childhood

Gallo, Linda C.

374

COURSE SYLLABUS Psychology 350: Abnormal Psychology  

E-print Network

Personality Disorders Ch 12 Feb 23 Test 2--100 points; Ch11, 7, 12 plus lecture notes March 2 Abnormal readings, and are objective (multiple choice, true false, matching). Test 1 will be on Jan 26th, test 2 applies to you and your life personally, or to someone you know, including your own reactions and your

Gallo, Linda C.

375

Chromosome abnormalities in Japanese quail embryos  

E-print Network

Chromosome abnormalities in Japanese quail embryos CA de la Sena NS Fechheimer KE Nestor The Ohio-Auzeville, 10-13 July 1990) Japanese quail / embryos / heteroploidy / chromosomes INTRODUCTION Embryos zygotes and the etiology of heteroploid zygotes and embryos (Fechheimer, 1981, 1990). The Japanese quail

Paris-Sud XI, Université de

376

Sensory Abnormalities in Autism: A Brief Report  

ERIC Educational Resources Information Center

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…

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

2011-01-01

377

Challenges in Emergency and Abnormal Checklist Design  

E-print Network

is funded through the NASA Aviation Safety and Security Program. #12;Emergency and Abnormal Situations to merger) Manufacturers: Regulatory and Governmental Agencies: Unions and Trade Groups: Accident smoke alarm rate EROPS ­ nearest airport is far away Ditching while on fire How much troubleshooting

378

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

379

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

380

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

381

Renal abnormalities in sickle cell disease  

Microsoft Academic Search

Renal abnormalities in sickle cell disease. Sickle cell nephropathy is indicated by sickled erythrocytes, with the consequent effects of decreased medullary blood flow, ischemia, microinfarct and papillary necrosis. Impaired urinary concentrating ability, renal acidification, hematuria, and potassium secretion are also found. There may be a causal relationship between an increase in nitric oxide synthesis and experimental sickle cell nephropathy, and

Phuong-Thu T Pham; Phuong-Chi T Pham; Alan H Wilkinson; Susie Q Lew

2000-01-01

382

Abnormal children of a 47,XYY father  

Microsoft Academic Search

Abnormal children of two 47,XYY men were studied. One of these men had 2 normal daughters and a child, 45,X\\/46,XY, with gonadal dysgenesis. The other man had 2 normal sons and a child with Down's syndrome. The extra chromosome 21 of this child came from the mother. Another 47,XYY man had 4 normal children.

C Stoll; E Flori; A Clavert; D Beshara; P Buck

1979-01-01

383

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

384

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.

385

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

386

On (ab)normality: Einstein's fusiform gyrus.  

PubMed

Recently, Hines (2014) wrote an evocative paper challenging findings from both histological and morphological studies of Einstein's brain. In this discussion paper, I extend Hines' theoretical point and further discuss how best to determine 'abnormal' morphology. To do so, I assess the sulcal patterning of Einstein's fusiform gyrus (FG) for the first time. The sulcal patterning of the FG was unconsidered in prior studies because the morphological features of the mid-fusiform sulcus have only been clarified recently. On the one hand, the sulcal patterning of Einstein's FG is abnormal relative to averages of 'normal' brains generated from two independent datasets (N=39 and N=15, respectively). On the other hand, within the 108 hemispheres used to make these average brains, it is not impossible to find FG sulcal patterns that resemble those of Einstein. Thus, concluding whether a morphological pattern is normal or abnormal heavily depends on the chosen analysis method (e.g. group average vs. individual). Such findings question the functional meaning of morphological 'abnormalities' when determined by comparing an individual to an average brain or average frequency characteristics. These observations are not only important for analyzing a rare brain such as that of Einstein, but also for comparing macroanatomical features between typical and atypical populations. PMID:25562419

Weiner, Kevin S

2015-03-01

387

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

388

Abnormally high formation pressures, Potwar Plateau, Pakistan  

USGS Publications Warehouse

Abnormally high formation pressures in the Potwar Plateau of north-central Pakistan are major obstacles to oil and gas exploration. Severe drilling problems associated with high pressures have, in some cases, prevented adequate evaluation of reservoirs and significantly increased drilling costs. Previous investigations of abnormal pressure in the Potwar Plateau have only identified abnormal pressures in Neogene rocks. We have identified two distinct pressure regimes in this Himalayan foreland fold and thrust belt basin: one in Neogene rocks and another in pre-Neogene rocks. Pore pressures in Neogene rocks are as high as lithostatic and are interpreted to be due to tectonic compression and compaction disequilibrium associated with high rates of sedimentation. Pore pressure gradients in pre-Neogene rocks are generally less than those in Neogene rocks, commonly ranging from 0.5 to 0.7 psi/ft (11.3 to 15.8 kPa/m) and are most likely due to a combination of tectonic compression and hydrocarbon generation. The top of abnormally high pressure is highly variable and doesn't appear to be related to any specific lithologic seal. Consequently, attempts to predict the depth to the top of overpressure prior to drilling are precluded.

Law, B.E.; Shah, S.H.A.; Malik, M.A.

1998-01-01

389

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

390

OXIDATIVE STRESS AS A POSSIBLE MODE OF ACTION FOR ARSENIC CARCINOGENESIS  

EPA Science Inventory

Abstract Many modes of action for arsenic carcinogenesis have been proposed, but few theories have a substantial mass of supporting data. Three stronger theories of arsenic carcinogenesis are production of chromosomal abnormalities, promotion of carcinogenesis and oxidati...

391

Influence of the water surface on the glow-to-spark transition in a metal-pin-to-water electrode system  

NASA Astrophysics Data System (ADS)

The glow-to-spark transition in a pin-to-water anode electrode system is investigated and compared with a pin-to-metal-plate system with 20 ns time resolution by fast imaging and corresponding current and voltage measurements. A contraction of the anode spot and cathode spot of the glow is observed in the pin-metal-plate system leading to a narrow filamentary spark, while the anode spot on the water anode electrode remains diffuse. In the latter case only a significant radial constriction of the glow in the bulk and near the metal cathode of the discharge gap is observed which causes a broadening of the spark near the water anode. Constriction of this broadened spark channel occurs several 100 ns after spark ignition. Additionally, the influence of the conductivity of the liquid electrode on the glow-to-spark transition is investigated.

Bruggeman, Peter; Guns, Peter; Degroote, Joris; Vierendeels, Jan; Leys, Christophe

2008-11-01

392

The use of cathodoluminescence for the development of durable self-glowing crystals based on solid solutions YPO 4 -EuPO 4  

Microsoft Academic Search

Local cathodoluminescence spectroscopy has been suggested for the development of durable self-glowing crystals based on crystalline\\u000a solid solutions (Y, Eu)PO4. Nonradioactive ions of Eu3+ in these crystals cause strong luminescence in the visible range, initiated by small admixture (less than 1 wt %) of ?-radioactive\\u000a 238Pu. The intensity of self-glowing depends on the Y: Eu ratio and the 238Pu content.

B. E. Burakov; V. M. Garbuzov; A. A. Kitsay; V. A. Zirlin; M. A. Petrova; Ya. V. Domracheva; M. V. Zamoryanskaya; E. V. Kolesnikova; M. A. Yagovkina; M. P. Orlova

2007-01-01

393

Fabrication of Dense Non-Circular Nanomagnetic Device Arrays Using Self-Limiting Low-Energy Glow-Discharge Processing  

PubMed Central

We describe a low-energy glow-discharge process using reactive ion etching system that enables non-circular device patterns, such as squares or hexagons, to be formed from a precursor array of uniform circular openings in polymethyl methacrylate, PMMA, defined by electron beam lithography. This technique is of a particular interest for bit-patterned magnetic recording medium fabrication, where close packed square magnetic bits may improve its recording performance. The process and results of generating close packed square patterns by self-limiting low-energy glow-discharge are investigated. Dense magnetic arrays formed by electrochemical deposition of nickel over self-limiting formed molds are demonstrated. PMID:23967340

Zheng, Zhen; Chang, Long; Nekrashevich, Ivan; Ruchhoeft, Paul; Khizroev, Sakhrat; Litvinov, Dmitri

2013-01-01

394

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

395

Additional chromosomal abnormalities in patients with a previously detected abnormal karyotype, mental retardation, and dysmorphic features.  

PubMed

The detection of chromosomal abnormalities in patients with mental retardation (MR) and dysmorphic features increases with improvements of molecular cytogenetic methods. We report on six patients referred for detailed characterization of chromosomal abnormalities (four translocations, one inversion, one deletion) detected by conventional cytogenetics, in whom metaphase CGH revealed imbalances not involved in the initially detected rearrangements. The detected abnormalities were validated by real-time PCR. Parents were investigated by CGH in four cases. The genomic screening revealed interstitial deletions of 2q33.2-q34, 3p21, 4q12-q13.1, 6q25, 13q22.2-q31.1, and 14q12. The estimated minimum sizes of the deletions ranged from 2.65 to 9.27 Mb. The CGH assay did not reveal imbalances that colocalized with the breakpoints of the inversion or the translocations. The deletion of 6q included ESR1, in which polymorphisms are associated with variation of adult height. FOXG1B, known to be involved in cortical development, was located in the 14q deletion. The results illustrate that whole-genome molecular cytogenetic analysis of phenotypically affected patients with abnormal conventional karyotypes may detect inapparent molecular cytogenetic abnormalities in patients with microscopic chromosomal abnormalities and that these data provide additional information of clinical importance. PMID:16955412

Bisgaard, Anne-Marie; Kirchhoff, Maria; Tümer, Zeynep; Jepsen, Birgit; Brøndum-Nielsen, Karen; Cohen, Monika; Hamborg-Petersen, Bente; Bryndorf, Thue; Tommerup, Niels; Skovby, Flemming

2006-10-15

396

Carbon CoDeposition Studies in DIII-D L- and H-Mode Plasmas and Implications to the ITER Tritium Inventory  

Microsoft Academic Search

A carbon-13 tracer injection experiment into ITER-like lower single-null partially detached ELMy H-mode plasma was carried out on DIII-D. 2.2x10^22 ^13C atoms were injected as ^13CH4 in a toroidally symmetric way in 17 identical 5s shots. Residual gas analysis of effluent during He glow indicated that ˜1% of ^13C atoms escaped as ^13CD4. 64 tiles were removed from the vessel

A. G. McLean; S. L. Allen; W. R. Wampler; D. G. Whyte; N. H. Brooks; A. Nagy; D. L. Rudakov; V. Phillips; G. F. Matthews

2005-01-01

397

What is Local Mode (LM)? Global Mode (GM)? Calibration Mode?  

The MISR instrument can acquire measurement in Global Mode (GM), Local Mode (LM), and Calibration. Global Mode is the normal acquisition with pole to pole coverage on the day-lit side or the orbit, full resolution (275m) in all 4 nadir bands and...

2013-04-26

398

Lie algebroids and optimal control: abnormality  

NASA Astrophysics Data System (ADS)

Candidates to be solutions to optimal control problems, called extremals, are found using Pontryagin's Maximum Principle [9]. This Principle gives necessary conditions for optimality and, under suitable assumptions, starts a presymplectic constraint algorithm in the sense given in [3]. This procedure, first considered in optimal control theory in [6], can be adapted to characterize the different kinds of extremals [1]. In this paper, we describe the constraints given by the algorithm for the so-called abnormal extremals for optimal control problems defined on Lie algebroids [4, 7, 8]. The peculiarity of the abnormal extremals is their independence on the cost function to characterize them. In particular, we are interested in how useful the geometry provided by the Lie algebroid is to study the constraints obtained in the optimal control problems for affine connection control systems. These systems model the motion of different types of mechanical systems such as rigid bodies, nonholonomic systems and robotic arms [2].

Barbero-Liñán, M.; de Diego, D. Martín; Muñoz-Lecanda, M. C.

2009-05-01

399

Behavioral correlates of epileptiform abnormalities in autism.  

PubMed

There is a high incidence of epileptiform abnormalities in children with autism even in the absence of clinical seizures. These findings are most prominent during sleep recordings. The significance of these abnormalities is unclear. Although studies do not all agree, there may be some association between cognitive function, behavior, and the presence or absence of epileptiform discharges. Small studies of anticonvulsant treatment mostly suggest an improvement in certain aspects of cognitive or behavioral functioning in these children, but larger and more comprehensive studies are needed to determine the potential relationship between epileptiform discharges on EEG, cognitive and behavioral functioning, and treatment effects in the population with autism. This article is part of a Special Issue entitled "Autism and Epilepsy". PMID:25453621

Trauner, Doris A

2014-11-01

400

[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

401

Chromosomal abnormalities in a psychiatric population  

SciTech Connect

Over a 3.5 year period of time, 345 patients hospitalized for psychiatric problems were evaluated cytogenetically. The patient population included 76% males and 94% children with a mean age of 12 years. The criteria for testing was an undiagnosed etiology for mental retardation and/or autism. Cytogenetic studies identified 11, or 3%, with abnormal karyotypes, including 4 fragile X positive individuals (2 males, 2 females), and 8 with chromosomal aneuploidy, rearrangements, or deletions. While individuals with chromosomal abnormalities do not demonstrate specific behavioral, psychiatric, or developmental problems relative to other psychiatric patients, our results demonstrate the need for an increased awareness to order chromosomal analysis and fragile X testing in those individuals who have combinations of behavioral/psychiatric, learning, communication, or cognitive disturbance. 5 refs., 1 fig., 2 tabs.

Lewis, K.E.; Lubetsky, M.J.; Wenger, S.L.; Steele, M.W. [Univ. of Pittsburgh Medical Center, PA (United States)

1995-02-27

402

Selective mutism and abnormal electroencephalography (EEG) tracings.  

PubMed

Epileptic discharges are not considered a part of the clinical picture of selective mutism, and electroencephalography is generally not recommended in its work-up. This report describes 6 children with selective mutism who were found to have a history of epilepsy and abnormal interictal or subclinical electroencephalography recordings. Two of them had benign epilepsy of childhood with centro-temporal spikes. The mutism was not related in time to the presence of active seizures. While seizures could be controlled in all children by medications, the mutism resolved only in 1. Although the discharges could be coincidental, they might represent a co-morbidity of selective mutism or even play a role in its pathogenesis. Selective mutism should be listed among the psychiatric disorders that may be associated with electroencephalographic abnormalities. It can probably be regarded as a symptom of a more complicated organic brain disorder. PMID:21596703

Politi, Keren; Kivity, Sara; Goldberg-Stern, Hadassa; Halevi, Ayelet; Shuper, Avinoam

2011-11-01

403

Modification of the surface of polytetrafluoroethylene in a glow discharge plasma in vapors of various organic compounds  

SciTech Connect

The process of modifying the surface of polytetrafluoroethylene in a glow discharge plasma in vapors of organic compounds of various classes was investigated. It was established that the greatest increase of wettability is seen when modification is done in acrylic acid vapor. Multiple attenuated total internal reflection infrared spectroscopy was used to study the spectra of the coatings that formed and to demonstrate their difference in the case of acrylic acid. 10 refs., 3 figs., 1 tab.

Gol`dshtein, D.V.; Gil`man, A.B.; Shifrina, R.R.; Potapov, V.K.

1992-01-01

404

Investigations of processes in a glow electrical discharge singlet-oxygen generator for oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Singlet oxygen (SO) concentration exceeding 20% is obtained in pure oxygen with the help of a glow-discharge singlet oxygen generator (DSOG). SO concentration exceeding 30% is obtained using homogeneous or heterogeneous catalysts at 0.5-1 Torr of pure oxygen. The possibility to develop an electrical discharge singlet oxygen generator for oxygen-iodine lasers, which is an alternative to a SO chemical generator is demonstrated.

Lodin, V. J.; Ikonnikov, V. C.; Sirotin, S. A.; Zhdanovich, S. I.; Savin, Yuri V.; Adamenkov, Yu. A.; Rogojnikov, Yu. K.

2005-03-01

405

Investigations of processes in a glow electrical discharge singlet-oxygen generator for oxygen-iodine laser  

Microsoft Academic Search

Singlet oxygen (SO) concentration exceeding 20% is obtained in pure oxygen with the help of a glow-discharge singlet oxygen generator (DSOG). SO concentration exceeding 30% is obtained using homogeneous or heterogeneous catalysts at 0.5-1 Torr of pure oxygen. The possibility to develop an electrical discharge singlet oxygen generator for oxygen-iodine lasers, which is an alternative to a SO chemical generator

V. J. Lodin; V. C. Ikonnikov; S. A. Sirotin; S. I. Zhdanovich; Yuri V. Savin; Yu. A. Adamenkov; Yu. K. Rogojnikov

2005-01-01

406

Grafting of synthetic polyelectrolyte onto polymer surfaces--comparison of glow discharge and sup 60 Co-gamma-irradiation method  

SciTech Connect

Water soluble polyelectrolyte synthesized from natural rubber contains sulfamate and carboxylate groups similar to that of heparin. It is observed that synthetic heparinoid polyelectrolyte is capable of inhibiting blood coagulation. In the present study, we attempted to graft the same onto polystyrene and polymethylmethacrylate surfaces using glow discharge technique and {sup 60}Co-gamma-irradiation method, and the surfaces were compared with respect to water contact angle and platelet adhesion parameters. Heparinized surfaces are also evaluated for relative comparison.

Hari, P.R.; Sharma, C.P. (Sree Chitra Tirunal Institute for Medical Sciences Technology, Poojapura, Trivandrum (India))

1990-07-01

407

Rf glow discharge optical emission spectrometry for the analysis of arrays of Ni nanowires in nanoporous alumina and titania membranes  

Microsoft Academic Search

Anodic alumina (Al2O3) and titania (TiO2) nanoporous oxide membranes are among the most widely studied self-organized nanopore templates, formed by uniform and well aligned arrays of synthetized nanometric pores or tubes. Here, we perform a comparative study of the depth profiling analysis in self-ordered alumina and titania nanoporous membrane templates by means of the radiofrequency glow discharge coupled to optical

V. M. Prida; D. Navas; K. R. Pirota; M. Hernandez-Velez; A. Menéndez; N. Bordel; R. Pereiro; A. Sanz-Medel; B. Hernando; M. Vazquez

2006-01-01

408

Observation of Discharge Instability Induced by Shockwave in Self-Sustained High-Pressure Pulsed Glow Discharge  

Microsoft Academic Search

Self-sustained high-pressure pulsed glow discharge is applied to excitation discharge on transversely excited atmospheric (TEA) gas lasers. Influence of shockwaves with Mach number MS of 1.1 and 1.35 on the discharge has been investigated. The normal Shockwave, which is normal to gas flow direction in TEA gas lasers, is produced by a shock tube with gas mixture of helium and

Go Imada; Masataro Suzuki; Wataru Masuda

2007-01-01

409

Rare, or simply overlooked? Practical notes for survey and monitoring of the small glow-worm Phosphaenus hemipterus (Coleoptera: Lampyridae)  

Microsoft Academic Search

Phosphaenus hemipterus (Fourcroy, 1785) is considered a very rare glow-worm and has conse- quently been studied very little. This paper unites the scattered data on the known distribution of P. hemipterus and gives descriptions of habitat use, phenology and activity patterns at recently discovered sites in Belgium. Adult males were found from mid-June to mid-July and were most abundant on

Raphaël De Cock

2000-01-01

410

Investigation of the electron energy distribution function in hollow-cathode glow discharges in nitrogen and oxygen  

Microsoft Academic Search

The mechanism for the formation of the inverse electron distribution function is proposed and realized experimentally in a\\u000a nitrogen plasma of a hollow-cathode glow discharge. It is shown theoretically and experimentally that, for a broad range of\\u000a the parameters of an N2 discharge, it is possible to form a significant dip in the profile of the electron distribution function in

V. Yu. Bazhenov; A. V. Ryabtsev; I. A. Soloshenko; A. G. Terent'eva; V. A. Khomich; V. V. Tsiolko; A. I. Shchedrin

2001-01-01

411

[TMJ morphological changes in abnormal occlusion].  

PubMed

TMJ dysfunction is one of the most common diseases among all disorders of the maxillofacial region. Any abnormality in synchrony or amplitude of motion of the TMJ results in the malposition of the articular disc. Researchers and clinicians were always interested in topographic anatomy of the TMJ. There is currently no consensus on matters relating to changes in anatomical features of the TMJ by occlusal disturbances. PMID:23715443

Volkov, S I; Bazhenov, D V; Semkin, V A; Bogdanov, A O

2013-01-01

412

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

413

The handicap of abnormal colour vision.  

PubMed

All people with abnormal colour vision, except for a few mildly affected deuteranomals, report that they experience problems with colour in everyday life and at work. Contemporary society presents them with increasing problems because colour is now so widely used in printed materials and in computer displays. Equal opportunity law gives them protection against unfair discrimination in employment, so a decision to exclude a person from employment on the grounds of abnormal colour vision must now be well supported by good evidence and sound argument. This paper reviews the investigations that have contributed to understanding the nature and consequences of the problems they have. All those with abnormal colour vision are at a disadvantage with comparative colour tasks that involve precise matching of colours or discrimination of fine colour differences either because of their loss of colour discrimination or anomalous perception of metamers. The majority have problems when colour is used to code information, in man-made colour codes and in naturally occurring colour codes that signal ripeness of fruit, freshness of meat or illness. They can be denied the benefit of colour to mark out objects and organise complex visual displays. They may be unreliable when a colour name is used as an identifier. They are slower and less successful in search when colour is an attribute of the target object or is used to organise the visual display. Because those with the more severe forms of abnormal colour vision perceive a very limited gamut of colours, they are at a disadvantage in the pursuit and appreciation of those forms of art that use colour. PMID:15312030

Cole, Barry L

2004-07-01

414

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

415

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

416

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

417

Effects of traces of molecular gases (hydrogen, nitrogen) in glow discharges in noble gases  

NASA Astrophysics Data System (ADS)

The "Grimm" type of low pressure glow discharge source, introduced some forty years ago, has proved to be a versatile analytical source. A flat sample is used as the cathode and placed about 0.2mm away from the end of a hollow tubular anode leading to an obstructed discharge. When the source was first developed, it was used for the direct analysis of solid metallic samples by optical emission spectroscopy (OES), normally with argon as the plasma gas; it was soon found that, using suitable electrical parameters, the cathode material was sputtered uniformly from a circular crater of diameter equal to that of the tubular anode, so that the technique could be used for compositional depth profile analysis (CDPA). Over the years the capability and applications of the technique have steadily increased. The use of rf powered discharges now permits the analysis of non-conducting layers and samples; improved instrumental design now allows CDPA of ever thinner layers (e.g. resolution of layers 5 nm thick in multilayer stacks is possible). For the original bulk material application, pre-sputtering could be used to remove any surface contamination but for CDPA, analysis must start immediately the discharge is ignited, so that any surface contamination can introduce molecular gases into the plasma gas and have significant analytical consequences, especially for very thin layers; in addition, many types of samples now analysed contain molecular gases as components (either as occluded gas, or e.g. as a nitride or oxide), and this gas enters the discharge when the sample is sputtered. It is therefore important to investigate the effect of such foreign gases on the discharge, in particular on the spectral intensities and hence the analytical results. The presentation will concentrate mainly on the effect of hydrogen in argon discharges, in the concentration range 0-2 % v/v but other gas mixtures (e.g. Ar/N_2, Ne/H_2) will be considered for comparison. In general, the introduction of molecular gases can change the discharge impedance, alter the sputtering rate and crater profile and cause changes in the absolute and relative intensities of lines in both the atomic and ionic spectra of the sample element and the plasma gas. The authors wish to acknowledge financial support from EC funded Analytical Glow Discharge Research Training Network GLADNET, contract no. MRTN-CT-2006-035459. P. Smid thanks the Deutsche Forschungsgemeinschaft (Ref 436 TSE 17/7/06) for support while carrying out experiments at IFW Dresden.

Steers, E. B. M.; Smid, P.; Hoffmann, V.

2008-07-01

418

Abnormal functional connectivity density in Parkinson's disease.  

PubMed

The pathology of Parkinson's disease (PD) is not confined to the nigrostriatal pathway, but also involves widespread cerebral cortical areas. Using seed-based resting state functional connectivity, many previous studies have demonstrated that PD patients have abnormal functional integration. However, this technique strongly relies on a priori selection of the seed regions and may miss important unpredictable findings. Using an ultrafast voxel-wise functional connectivity density approach, this study performed a whole brain functional connectivity analysis to investigate the abnormal resting-state functional activities in PD patients. Compared with healthy controls, PD patients exhibited decreased short-range functional connectivity densities in regions that were mainly located in the ventral visual pathway and decreased long-range functional connectivity densities in the right middle and superior frontal gyrus, which have been speculated to be associated with visual hallucinations and cognitive dysfunction, respectively. PD patients also exhibited increased short- and long-range functional connectivity densities in the bilateral precuneus and posterior cingulate cortex, which may represent a compensatory process for maintaining normal brain function. The observed functional connectivity density alterations might be related to the disturbed structural connectivity of PD patients, leading to abnormal functional integration. Our results suggest that functional connectivity density mapping may provide a useful means to assess PD-related neurodegeneration and to study the pathophysiology of PD. PMID:25496782

Zhang, Jiuquan; Bi, Wenwei; Zhang, Yuling; Zhu, Maohu; Zhang, Yanling; Feng, Hua; Wang, Jian; Zhang, Yuanchao; Jiang, Tianzi

2015-03-01

419

Dynamic Abnormal Grain Growth in Molybdenum  

NASA Astrophysics Data System (ADS)

A new abnormal grain growth phenomenon that occurs only during continuous plastic straining, termed dynamic abnormal grain growth (DAGG), was observed in molybdenum (Mo) at elevated temperature. DAGG was produced in two commercial-purity molybdenum sheets and in a commercial-purity molybdenum wire. Single crystals, centimeters in length, were created in these materials through the DAGG process. DAGG was observed only at temperatures of 1713 K (1440 °C) and above and occurred across the range of strain rates investigated, ~10-5 to 10-4 s-1. DAGG initiates only after a critical plastic strain, which decreases with increasing temperature but is insensitive to strain rate. Following initiation of an abnormal grain, the rate of boundary migration during DAGG is on the order of 10 mm/min. This rapid growth provides a convenient means of producing large single crystals in the solid state. When significant normal grain growth occurs prior to DAGG, island grains result. DAGG was observed in sheet materials with two very different primary recrystallization textures. DAGG grains in Mo favor boundary growth along the tensile axis in a <110> direction, preferentially producing single crystals with orientations from an approximately <110> fiber family of orientations. A mechanism of boundary unpinning is proposed to explain the dependence of boundary migration on plastic straining during DAGG.

Worthington, Daniel L.; Pedrazas, Nicholas A.; Noell, Philip J.; Taleff, Eric M.

2013-11-01

420

Abnormal hemoglobins in a quarter million people.  

PubMed

Hemolysates of erythrocytes from more than a quarter million people in Alabama were electrophoresed on cellulose acetate, pH 8.4, and those samples exhibiting an abnormality were also electrophoresed in citrate agar, pH 6.0. The globin chains of mutants other than Hb S and C were electrophoresed in urea-mercaptoethanol buffers at both pH 8.9 and pH 6.0, and 60 of them were also analyzed structurally. Of about 6000 samples from whites, only three contained abnormal hemoglobins--Hb D Los Angeles, Hb J Baltimore, and one unidentified. Of 249,000 samples from blacks, about 29,000 contained electrophoretically detectable abnormalities, most of them associated with Hb S or C, present in a frequency of about 9% and 3%, respectively. About 1000 samples resolved into patterns of potential clinical significance. Twenty other mutant hemoglobins were detected, in various genetic combinations in 164 kindreds; four of these-Hb Alabama, Montgomery, Titusville, and Mobile--were previously unknown. The methods used are rapid, economical, and well suited for large scale surveys. They provide highly specific characterizations of many mutant hemoglobins, and no discrepancies were found between the presumptive identifications based on these characterizations and the definitive identifications obtained from structural analyses. PMID:974261

Schneider, R G; Hightower, B; Hosty, T S; Ryder, H; Tomlin, G; Atkins, R; Brimhall, B; Jones, R T

1976-11-01

421

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

422

Abnormal Asymmetry of Brain Connectivity in Schizophrenia  

PubMed Central

Recently, a growing body of data has revealed that beyond a dysfunction of connectivity among different brain areas in schizophrenia patients (SCZ), there is also an abnormal asymmetry of functional connectivity compared with healthy subjects. The loss of the cerebral torque and the abnormalities of gyrification, with an increased or more complex cortical folding in the right hemisphere may provide an anatomical basis for such aberrant connectivity in SCZ. Furthermore, diffusion tensor imaging studies have shown a significant reduction of leftward asymmetry in some key white-matter tracts in SCZ. In this paper, we review the studies that investigated both structural brain asymmetry and asymmetry of functional connectivity in healthy subjects and SCZ. From an analysis of the existing literature on this topic, we can hypothesize an overall generally attenuated asymmetry of functional connectivity in SCZ compared to healthy controls. Such attenuated asymmetry increases with the duration of the disease and correlates with psychotic symptoms. Finally, we hypothesize that structural deficits across the corpus callosum may contribute to the abnormal asymmetry of intra-hemispheric connectivity in schizophrenia. PMID:25566030

Ribolsi, Michele; Daskalakis, Zafiris J.; Siracusano, Alberto; Koch, Giacomo

2014-01-01

423

Electrocardiographic abnormalities in centenarians: impact on survival  

PubMed Central

Background The centenarian population is gradually increasing, so it is becoming more common to see centenarians in clinical practice. Electrocardiogram abnormalities in the elderly have been reported, but several methodological biases have been detected that limit the validity of their results. The aim of this study is to analyse the ECG abnormalities in a prospective study of the centenarian population and to assess their impact on survival. Method We performed a domiciliary visit, where a medical history, an ECG and blood analysis were obtained. Barthel index (BI), cognitive mini-exam (CME) and Charlson index (ChI) were all determined. Patients were followed up by telephone up until their death. Results A total of 80 centenarians were studied, 26 men and 64 women, mean age 100.8 (SD 1.3). Of these, 81% had been admitted to the hospital at least once in the past, 81.3% were taking drugs (mean 3.3, rank 0–11). ChI was 1.21 (SD 1.19). Men had higher scores both for BI (70 -SD 34.4- vs. 50.4 -SD 36.6-, P?=?.005) and CME (16.5 -SD 9.1- vs. 9.1 –SD 11.6-, P?=?.008); 40.3% of the centenarians had anaemia, 67.5% renal failure, 13% hyperglycaemia, 22.1% hypoalbuminaemia and 10.7% dyslipidaemia, without statistically significant differences regarding sex. Only 7% had a normal ECG; 21 (26.3%) had atrial fibrillation (AF), 30 (37.5%) conduction defects and 31 (38.8%) abnormalities suggestive of ischemia, without sex-related differences. A history of heart disease was significantly associated with the presence of AF (P?=?.002, OR 5.2, CI 95% 1.8 to 15.2) and changes suggestive of ischemia (P?=?.019, OR 3.2, CI 95% 1.2-8.7). Mean survival was 628?days (SD 578.5), median 481?days. Mortality risk was independently associated with the presence of AF (RR 2.0, P?=?.011), hyperglycaemia (RR 2.2, P?=?.032), hypoalbuminaemia (RR 3.5, P?abnormalities are common in centenarians, they are not related to sex, functional capacity or cognitive impairment. The only abnormality that has an impact on survival is AF. PMID:22520618

2012-01-01

424

How to Assess Changes in Feet: Normal or Abnormal  

MedlinePLUS

... in Feet: Normal or Abnormal How to Assess Changes in Feet: Normal or Abnormal Page Content The ... this extensive repetitive use leads to several normal changes associated with aging: The foot becomes wider and ...

425

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

426

NEW FRONTIER IN UNDERSTANDING THE MECHANISMS OF DEVELOPMENTAL ABNORMALITIES  

EPA Science Inventory

Recent advancements in molecular developmental biology afford an opportunity to apply newly developed tools for understanding the mechanisms of both normal and abnormal development. lthough a number of agents have been identified as causing developmental abnormalities, knowledge ...

427

Calibration of double focusing Glow Discharge Mass Spectrometry instruments with pin-shaped synthetic standards  

NASA Astrophysics Data System (ADS)

Calibration of two commercially available glow discharge double focusing mass spectrometers, the VG 9000 and Element GD, is described using synthetic pin standards pressed from solution doped copper and zinc matrices. A special pressing die was developed for this purpose and optimal results were obtained with the highest possible pressures, i.e., 95 kN·cm - 2 . This calibration approach permits the determination of trace element mass fractions down to ?g·kg - 1 with small uncertainties and additionally provides traceability of the GD-MS results in the most direct manner to the SI (International System of Units). Results were validated by concurrent measurements of a number of compact copper and zinc certified reference materials. The impact of the sample pin cross-section (circular or square) was investigated with the use of a new pin-sample holder system for the Element GD. The pin-sample holder was designed by the manufacturer for pin-samples having circular cross-section; however, samples with square pin cross-section were also shown to provide acceptable results. Relative Sensitivity Factors for some 50 analytes in copper (VG 9000, Element GD) and zinc matrices (VG 9000) are presented. The field of applicability of GD-MS may be considerably extended via analysis of pin geometry samples based on their ease of preparation, especially with respect to the accuracy and traceability of the results and the enhanced number of analytes which can be reliably calibrated using such samples.

Gusarova, T.; Methven, B.; Kipphardt, H.; Sturgeon, R.; Matschat, R.; Panne, U.

2011-11-01

428

Possible Mechanism of ``Additional'' Production of H^- in a Glow Discharge  

NASA Astrophysics Data System (ADS)

Based on measurements of H^- and H densities a DC glow discharge in H2 (P=0.1-3 Torr) the rate coefficient of H^- production as a function of E/N was determined. To analyze the mechanisms of H^- production, a simple model of H2 vibrational excitation was developed. Estimations of vibrational level densities (v=3-5) obtained from VUV absorption measurements were in reasonable agreement with the calculated data. The analysis revealed that standard mechanisms of H^- production (dissociative attachment to vibrationally excited molecules H2(v) and molecules in Rydberg states H2(Ry)) were not enough to explain the experimental results. In order to describe both the shape (vs E/N) and the magnitude of the measured H^- production rate coefficient, an ``additional'' source of H^-, having a strong resonant electron attachment CS in the range of ˜5-9 eV, should be invoked. Although H2 has no resonances in the 5-9 eV range, water is known to strongly dissociatively attach in this range. Thus, even small amounts (0.1-1%) of water vapor in the apparatus can explain the origin of the ``additional'' H^- production. This result is corroborated by the work of Cadez et. al. in Proc. of XXVII ICPIG, 2005. This work was supported by the RFBR (No.05-02-17649a), Scientific School - 171113.2003.2 and NATO Collaborative Linkage Grant (No.980097).

Belostotskiy, S.; Economou, D.; Lopaev, D.; Rakhimova, T.

2006-10-01

429

Surface Treatment of Polyethylene Terephthalate Film Using Atmospheric Pressure Glow Discharge in Air  

NASA Astrophysics Data System (ADS)

Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the surface oxygen content of PET surface increases to 39%, and the water contact angle decreases to 19°, respectively.

Fang, Zhi; Qiu, Yuchang; Wang, Hui

2004-12-01

430

Comparison of Dielectric Barrier Discharge and Atmospheric Pressure Glow Discharge for Surface Modification of PET Film  

NASA Astrophysics Data System (ADS)

Non-equilibrium plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In the present work polyethylene terephthalate (PET) film surface is modified using the non-equilibrium plasma generated by the atmospheric pressure glow discharge (APGD) and dielectric barrier discharge (DBD) in ambient air. The differences in discharge characteristics between APGD and DBD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena. The effects of APGD and DBD on PET surface modification are studied by comparing their surface properties, which are characterized by contact angle measurement, X-ray photoelectron spectroscopy (XPS) and scanning electronic microscopy (SEM). It is found that the APGD is quite homogeneous and stable in the whole gas gap, which differs from the filamentary micro-discharge of the DBD. It is concluded that the APGD and DBD treatments modify the PET surface in both morphology and composition, but APGD is more effective in PET surface modification than DBD as it can modify the surface more uniformly and make the contact angle decline to a lower level.

Fang, Zhi; Qiu, Yuchang; Kuffel, Edmund

431

Liquid-phase reactions induced by atmospheric pressure glow discharge with liquid electrode  

NASA Astrophysics Data System (ADS)

We experimentally investigated some of the initial reactions in a liquid induced by electron or positive-ion irradiation from an atmospheric-pressure dc glow discharge in contact with the liquid. We used an H-shaped glass reactor to observe the effects of electron irradiation and positive-ion irradiation on the liquid-phase reaction separately and simultaneously. Aqueous solutions of NaCl, AgNO3, HAuCl4, and FeCl2 are used as the electrolyte. Solutions of AgNO3 and HAuCl4 are used for the generation of Ag and Au nanoparticles, respectively. Solution of FeCl2 is used for the generation of ferromagnetic particles. Experimental results showed that electron irradiation of the liquid surface generates OH? in water and that positive-ion irradiation of the liquid surface generates H+ in water even without the dissolution of gas-phase nitrogen oxide. A possible reaction process is qualitatively discussed. We also showed that the control of reductive and oxidative environment in the liquid is possible not only by the gas composition for the plasma generation but also by the liquid composition.

Tochikubo, Fumiyoshi; Shirai, Naoki; Uchida, Satoshi

2014-12-01

432

Studies on gas breakdown in pulsed radio frequency atmospheric pressure glow discharges  

SciTech Connect

In pulsed RF atmospheric pressure glow discharges, the gas breakdown judged by the rapid drop in the amplitude of the pulsed RF voltage is no longer universally true. The steep increment of the plasma-absorbed RF power is proposed to determine the gas breakdown. The averaged plasma-absorbed RF power over a pulse period is used to evaluate effects of the preceding pulsed RF discharge on the breakdown voltage of the following one, finding that the breakdown voltage decreases with the increment in the averaged plasma-absorbed RF power under constant pulse duty ratio. Effects of the pulse off-time on the breakdown voltage and the breakdown delay time are also studied. The obtained dependence of the breakdown voltage on the pulse off-time is indicative of the transitional plasma diffusion processes in the afterglow. The breakdown voltage varies rapidly as the plasma diffuses fast in the region of moderate pulse off-time. The contribution of nitrogen atom recombination at the alumina surface is demonstrated in the prolonged memory effect on the breakdown delay time vs. the pulse off-time and experimentally validated by introducing a trace amount of nitrogen into argon at short and long pulse off-times.

Huo, W. G. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029 (China); Jian, S. J.; Yao, J.; Ding, Z. F., E-mail: zfding@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China)

2014-05-15

433

Oxygen-iodine active medium with external production of iodine in a DC glow discharge  

NASA Astrophysics Data System (ADS)

Experiments with a flow cell apparatus imitating conditions of oxygen-iodine laser, equipped with a chemical jet singlet oxygen generator and an electric discharge iodine generator have been performed. I II and CH 3I in the flow of Ar were used as atomic iodine precursors. The distributions of the electronically excited species along the flow were examined detecting their optical emissions. A straightforward comparison of two methods of oxygen-iodine medium production - conventional, by means of I II dissociation in the singlet oxygen flow and with iodine atoms produced externally in the electric discharge - was performed. It was found that stored electron energy lifetime had been about 30% longer, when iodine was produced from CH 3I in the discharge, compared to the conventional I II dissociation in the singlet oxygen flow. It was observed that maximums of the I(2P 1/2) and I II(B) concentrations had shifted to the nozzle plane, when I II in Ar carrier was subjected to the glow discharge, pointing to a nearly twofold increase in the I II dissociation rate. Contrary to the known results for low iodine and singlet oxygen concentrations, squared dependence of the amplitude of the I II(B) luminescence maximum with I(2P 1/2) concentration was observed in the dissociation region for both methods of iodine production.

Mikheyev, Pavel A.; Azyazov, Valeriy N.; Mezhenin, Adrew V.; Ufimtsev, Nikolay I.; Shepelenko, Alexander A.; Voronov, Anatoly I.; Kupryaev, Nikolay V.; Pichugin, Sergey Yu.; Vorobyov, Mikhail V.

2007-05-01

434

A surface chemistry model for the production of N 2 LBH spacecraft glow  

NASA Astrophysics Data System (ADS)

Spacecraft-atmosphere interactions leading to N 2 Lyman-Birge-Hopfield (LBH) bands in the 1400-1700 Å ultraviolet (reported by Conway et at., 1987, Geophys. Res. Lett.14, 628) have been proposed to result from surface recombination of N (Kofsky, 1988, Geophys. Res. Lett.15, 241; Swenson and Meyerott, 1988, Geophys. Res. Lett. 15, 245). The surface recombination of N( 4S) can populate the a1? g, state (which leads to N 2 LBH emission) either (1) directly, or (2) by cascade from higher excited states of N 2. Gas phase recombination produces a1? q populations in ? = 4-6, whereas the observed spacecraft surface interactions lower the vibrational population. This study describes and explores the possible cascade (2) mechanism where the upper states of N 2 (particularly c' 41?+u) are populated with the translational energy of ramming N on surface bound N, in recombination. The cascade mechanism would populate the a1?g, ? = 0-1 directly. The proposed cascade mechanism predicts additional emissions at ˜ 3000 Å (Gaydon Herman band system) and ˜ 958 Å from the surface recombination. The 958 Å photons can resonant scatter in the spacecraft cloud and atmospheric N 2 which would result in extended spacecraft glows in low Earth orbit. The altitude profile is predicted and compared with observations. The predicted emissions offer criteria for experimental confirmation of the (1) "direct" vs (2) "cascade" mechanisms.

Meyerott, R. E.; Swenson, G. R.

1990-04-01

435

Characteristics of line pulsed glow discharge plasma at atmospheric pressure for preparation of amorphous carbon films  

NASA Astrophysics Data System (ADS)

Diamond-like carbon (DLC) films have excellent physical and chemical properties for applications such as high mechanical hardness, low friction, chemical inertness, electrical insulation, optical transparency, and biological compatibility. For preparation of large-area amorphous carbon film, the line glow discharge plasma (LGDP) at atmospheric pressure was produced with a high-voltage, high-repetition bipolar pulse using the three-electrode configuration in our experiment. The DBD source plasma was generated by a high-voltage, high-repetition bipolar pulse with a fast rise time using the parallel-plate geometry with a gap width of 2 mm. Two quartz glasses were placed between two electrodes made of stainless-steel to produce DBD. A mixed gas of He as a carrier gas and CH4 as a precursor was supplied to the discharge region. Applying another pulsed bias voltage to the gap between the parallel plate electrode and the bias electrode (stainless-steel substrate), the LGDP was extracted on the substrate for a film deposition. When the pulsed bias voltage was applied to the substrate at several ?s later, the largest intensity of LGDP was observed at the both polarity of bias voltage. We will show the detail characteristics of the LGDP.

Fukui, K.; Miyamae, M.; Kikuchi, Y.; Matsuo, Y.; Horiguchi, Y.; Nishimura, Y.; Nagata, M.; Yatsuzuka, M.

2011-11-01

436

Subsonic Plasma Aerodynamics using Lorentzian Momentum Transfer in Atmospheric Normal Glow Discharge Plasmas  

NASA Astrophysics Data System (ADS)

The recent development of the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has made it possible to cover large areas, including the wings and fuselage of aircraft, with a thin layer of plasma at low energy cost. The Lorentzian collisions between the ions and neutral gas in the plasma layer couple the electric field and the neutral gas in this layer. The coupling is strong enough at one atmosphere to accelerate the boundary layer flow. One EHD flow acceleration method is based on paraelectric EHD effects, the electrostatic analog of paramagnetism, in which a plasma is accelerated toward increasing electric field gradients, while dragging the neutral gas with it. By using paraelectric effects to add momentum to the flow, we have recently achieved improved flow attachment and increased stall angles in airfoils for external aerodynamic applications. In a second approach, peristaltic flow acceleration, we have used a polyphase power supply to excite the OAUGDP at progressive voltage phase angles on successive linear electrode strips. This excitation produces a traveling wave analogous to the "moving" lights on a theatre marquee, which accelerates the ions and neutral gas to velocities of aerodynamic interest.

Reece Roth, J.; Sin, Hojung; Mohan Madhan, Raja Chandra

2002-10-01

437

High frequency glow discharges at atmospheric pressure with micro-structured electrode arrays  

NASA Astrophysics Data System (ADS)

Micro-structured electrode (MSE) arrays allow the generation of large-area uniform glow discharges over a wide pressure range up to atmospheric pressure. The electrode widths, thicknesses and distances in the micrometre range are realized by means of modern micro-machining and galvanic techniques. The electrode distance, the gap width d, is small enough to generate sufficiently high electric field strengths to ignite gas discharges by applying only moderate radio frequency (RF, 13.56 MHz) voltages (80-390 V in Ne, He, Ar, N2 and air). The non-thermal plasma system is characterized by a special probe measuring the electric parameters. We tested MSE arrays with d = 70, 25 and 15 µm. The MSE driven plasmas show a different behaviour from conventional RF discharge plasmas. Due to the very small electrode gap width we can describe the behaviour of the charged particles in the RF field of our system with the dc Townsend breakdown theory, depending on the pressure range and gas. With decreasing pressure, the gas discharges, especially in Ne and He, are increasingly dominated by field electron emission. With the MSE arrays as plasma sources several applications were developed and successfully tested, e.g. decomposition of waste gases and sterilization of food packaging materials at atmospheric pressure.

Baars-Hibbe, L.; Sichler, P.; Schrader, C.; Lucas, N.; Gericke, K.-H.; Büttgenbach, S.

2005-02-01

438

Surface characterization of radio-frequency glow discharged and autoclaved titanium surfaces.  

PubMed

To characterize titanium surfaces treated with radio-frequency glow discharge (RFGD) after media exposure, surface chemical analyses were performed using x-ray photoelectron spectroscopy. Auger electron spectroscopy, and Fourier transform infrared-reflection absorption spectroscopy (FTIR-RAS). The RFGD treatments resulted in a cleaner surface as compared to as-sputtered or as-autoclaved titanium specimens. The oxide thickness of RFGD-treated titanium specimens was not statistically different from the as-autoclaved and as-sputter cleaned titanium specimens. Exposure to a phosphate-buffered saline solution revealed a greater deposition of calcium and phosphorous on the RFGD-treated surfaces. Auger electron spectroscopy depth profiles showed that calcium and phosphorous ions diffused into the titanium oxide layer. The calcium and phosphorous deposits were identified as amorphous calcium phosphate compounds using FTIR-RAS. These results suggest that RFGD treatments of titanium enhance calcium and/or phosphate affinity because of an increase in elemental interactions at the surface, thereby resulting in the formation of amorphous calcium phosphate compounds. PMID:8803338

Kawahara, D; Ong, J L; Raikar, G N; Lucas, L C; Lemons, J E; Nakamura, M

1996-01-01

439

Electrical double layers at shock fronts in glow discharges and afterglows  

NASA Astrophysics Data System (ADS)

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 1s5 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.

2010-12-01

440

Femtosecond Laser Ablation Particle Introduction to a Liquid Sampling-Atmospheric Pressure Glow Discharge Ionization Source  

SciTech Connect

This work describes the use of a compact, liquid sampling – atmospheric pressure glow discharge (LS-APGD) ionization source to ionize metal particles within a laser ablation aerosol. Mass analysis was performed with a Thermo Scientific Exactive Mass Spectrometer which utilizes an orbitrap mass analyzer capable of producing mass resolution exceeding M/?M > 160,000. The LS-APGD source generates a low-power plasma between the surface of an electrolytic solution flowing at several µl min-1 through a fused silica capillary and a counter electrode consisting of a stainless steel capillary employed to deliver the laser ablation particles into the plasma. Sample particles of approximately 100 nm were generated with an Applied Spectra femtosecond laser located remotely and transported through 25 meters of polyurethane tubing by means of argon carrier gas. Samples consisted of an oxygen free copper shard, a disk of solder, and a one-cent U.S. coin. Analyte signal onset was readily detectable relative to the background signal produced by the carrier gas alone. The high mass resolution capability of the orbitrap mass spectrometer was demonstrated on the solder sample with resolution exceeding 90,000 for Pb and 160,000 for Cu. In addition, results from a laser ablation depth-profiling experiment of a one cent coin revealed retention of the relative locations of the ~10 µm copper cladding and zinc rich bulk layers.

Carado, Anthony J.; Quarles, C. Derrick; Duffin, Andrew M.; Barinaga, Charles J.; Russo, Richard; Marcus, R. Kenneth; Eiden, Gregory C.; Koppenaal, David W.

2012-01-16

441

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

442

Inhibition of monocyte adhesion and fibrinogen adsorption on glow discharge plasma deposited tetraethylene glycol dimethyl ether.  

PubMed

Monocytes and macrophages play important roles in host responses to implanted biomedical devices. Monocyte and macrophage interactions with biomaterial surfaces are thought to be mediated by adsorbed adhesive proteins such as fibrinogen and fibronectin. Non-fouling surfaces that minimize protein adsorption may therefore minimize monocyte adhesion, activation, and the foreign body response. Radio-frequency glow discharge plasma deposition (RF-GDPD) of tetraethylene glycol dimethyl ether (tetraglyme) was used to produce polyethylene oxide (PEO)-like coatings on a fluorinated ethylene-propylene (FEP) surface. Electron spectroscopy for chemical analysis (ESCA) and static time of flight secondary ion mass spectrometry (ToF-SIMS) were used to characterize the surface chemistry of tetraglyme coating. Fibrinogen adsorption to the tetraglyme surface was measured with 125I-labeled fibrinogen and ToF-SIMS. Adsorption of fibrinogen to plasma deposited tetraglyme was less than 10 ng cm(-2), a 20-fold decrease compared to untreated FEP or tissue culture polystyrene (TCPS). Monocyte adhesion to plasma deposited tetraglyme was significantly lower than adhesion to FEP or TCPS. In addition, when the surfaces were preadsorbed with fibrinogen, fibronectin, or blood plasma, monocyte adhesion to plasma deposited tetraglyme after 2 h or 1 day was much lower than adhesion to FEP. RF-GDPD tetraglyme coating provides a promising approach to make non-fouling biomaterials that can inhibit non-specific material-host interactions and reduce the foreign body response. PMID:11787523

Shen, M; Pan, Y V; Wagner, M S; Hauch, K D; Castner, D G; Ratner, B D; Horbett, T A

2001-01-01

443

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

444

PSY 350 Spring 2011 Page 1 of 5 ABNORMAL PSYCHOLOGY  

E-print Network

PSY 350 Spring 2011 Page 1 of 5 - 1 - PSY 350 ABNORMAL PSYCHOLOGY SPRING 2011 Course Information students with the major concepts, theoretical perspectives and empirical findings in abnormal psychology., Johnson, S.L., Davison, Gerald C., Neale, John M. (2004). Abnormal Psychology, 11th Edition. New York

Gallo, Linda C.

445

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

446

PSYCHOLOGY 280: ABNORMAL PSYCHOLOGY Summer 2014 -Section 101  

E-print Network

PSYCHOLOGY 280: ABNORMAL PSYCHOLOGY Summer 2014 - Section 101 Tuesdays, Wednesdays, and Thursdays variety of topics in the field of abnormal psychology, including its history and the methods used). Abnormal psychology in a changing world (9th ed.). Upper Saddle River, NJ: Pearson Education, Inc. Textbook

Liu, Taosheng

447

Physics Division ESH Bulletin 03-1 ABNORMAL EVENT RESPONSE  

E-print Network

: Abnormal Event Response The expectation of ORNL management is a bias toward identifying and reporting allPhysics Division ESH Bulletin 03-1 ABNORMAL EVENT RESPONSE Reference ORNL Program Description abnormal events, even small, seemingly insignificant or low-level events or conditions. Fixing lower level

448

Eye Movement Abnormalities in Joubert Syndrome  

PubMed Central

Purpose Joubert syndrome is a genetic disorder characterized by hypoplasia of the midline cerebellum and deficiency of crossed connections between neural structures in the brain stem that control eye movements. The goal of the study was to quantify the eye movement abnormalities that occur in Joubert syndrome. Methods Eye movements were recorded in response to stationary stimuli and stimuli designed to elicit smooth pursuit, saccades, optokinetic nystagmus (OKN), vestibulo-ocular reflex (VOR), and vergence using video-oculography or Skalar search coils in 8 patients with Joubert syndrome. All patients underwent high-resolution magnetic resonance imaging (MRI). Results All patients had the highly characteristic molar tooth sign on brain MRI. Six patients had conjugate pendular (n = 4) or see-saw nystagmus (n = 2); gaze holding was stable in four patients. Smooth-pursuit gains were 0.28 to 1.19, 0.11 to 0.68, and 0.33 to 0.73 at peak stimulus velocities of 10, 20, and 30 deg/s in six patients; smooth pursuit could not be elicited in four patients. Saccade gains in five patients ranged from 0.35 to 0.91 and velocities ranged from 60.9 to 259.5 deg/s. Targeted saccades could not be elicited in five patients. Horizontal OKN gain was uniformly reduced across gratings drifted at velocities of 15, 30, and 45 deg/s. VOR gain was 0.8 or higher and phase appropriate in three of seven subjects; VOR gain was 0.3 or less and phase was indeterminate in four subjects. Conclusions The abnormalities in gaze-holding and eye movements are consistent with the distributed abnormalities of midline cerebellum and brain stem regions associated with Joubert syndrome. PMID:19443711

Weiss, Avery H.; Doherty, Dan; Parisi, Melissa; Shaw, Dennis; Glass, Ian; Phillips, James O.

2011-01-01

449

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

450

Gynaecological abnormalities found at a cytology clinic.  

PubMed

A survey was made of abnormalities found on pelvic examination of 2,656 women who attended for cervical smears in the three years 1967-9. Eight women had malignant cells in their smears, and 68 women pelvic tumours, four of them malignant. Severe vulvitis was common in women over 46. Many of the women who had non-malignant conditions were treated though they had no complaints. They were among the most appreciative and subsequently sought out the clinic staff to thank them. It is important that a full examination should be made by an experienced gynaecologist. PMID:4419175

Edwards, D

1974-10-26

451

Nail abnormalities associated with systemic pathologies.  

PubMed

Nail abnormalities can arise in conjunction with or as a result of systematic pathologies. These pathologies include single-organ diseases, multisystemic diseases, and drug-induced insults. Clinical signs associated with these conditions include dyschromias, vascular alterations, periungual tissue changes, textural dystrophies, contour alterations, and growth-rate alterations. The associated systemic pathologies may affect any part of the nail apparatus, including the nail matrix, the nail plate, the nail bed, the underlying vasculature, and the periungual tissues. The anatomical location and extent of damage determine the clinically manifested anomaly. PMID:24079592

Zaiac, Martin N; Walker, Ashley

2013-01-01

452

Vision function abnormalities in Alzheimer disease.  

PubMed

Alzheimer disease (AD) is a progressive, age-related debilitating condition that is a growing public health problem in the developed world. Visual system abnormalities in AD were recognized in the early 1970s, but were initially considered to be of strictly cortical origin. Studies in the past 20 years reveal that all parts of the visual system may be affected, including the optic nerve and the retina. Some aspects of this involvement are still not well understood and are the subjects of intensive research. We summarize and focus on findings that may be of more practical interest to the ophthalmologist. PMID:24309127

Tzekov, Radouil; Mullan, Michael

2014-01-01

453

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

454

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

455

Abnormal Elastic and Vibrational Behaviors of Magnetite at High Pressures  

PubMed Central

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. 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

456

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; CAÑIVE, JOSÉ M.; MILLER, GREGORY A.

2009-01-01

457

Native fluorescence characterization of human liver abnormalities  

NASA Astrophysics Data System (ADS)

Fluorescence spectroscopy of intrinsic biomolecules has been extensively used in biology and medicine for the past several decades. In the present study, we report the native fluorescence characteristics of blood plasma from normal human subjects and patients with different liver abnormalities such as hepatitis, leptospirosis, jaundice, cirrhosis and liver cell failure. Native fluorescence spectra of blood plasma -- acetone extract were measured at 405 nm excitation. The average spectrum of normal blood plasma has a prominent emission peak around 464 nm whereas in the case of liver diseased subjects, the primary peak is red shifted with respect to normal. In addition, liver diseased cases show distinct secondary emission peak around 615 nm, which may be attributed to the presence of endogenous porphyrins. The red shift of the prominent emission peak with respect to normal is found to be maximum for hepatitis and minimum for cirrhosis whereas the secondary emission peak around 615 nm was found to be more prominent in the case of cirrhosis than the rest. The ratio parameter I465/I615 is found to be statistically significant (p less than 0.001) in discriminating liver abnormalities from normal.

Ganesan, Singaravelu; Madhuri, S.; Aruna, Prakasa R.; Suchitra, S.; Srinivasan, T. G.

1999-05-01

458

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

459

Brain Abnormalities in Neuromyelitis Optica Spectrum Disorder  

PubMed Central

Neuromyelitis optica (NMO) is an idiopathic inflammatory syndrome of the central nervous system that is characterized by severe attacks of optic neuritis (ON) and myelitis. Until recently, NMO was considered a disease without brain involvement. However, since the discovery of NMO-IgG/antiaqaporin-4 antibody, the concept of NMO was broadened to NMO spectrum disorder (NMOSD), and brain lesions are commonly recognized. Furthermore, some patients present with brain symptoms as their first manifestation and develop recurrent brain symptoms without ON or myelitis. Brain lesions with characteristic locations and configurations can be helpful in the diagnosis of NMOSD. Due to the growing recognition of brain abnormalities in NMOSD, these have been included in the NMO and NMOSD diagnostic criteria or guidelines. Recent technical developments such as diffusion tensor imaging, MR spectroscopy, and voxel-based morphometry reveal new findings related to brain abnormalities in NMOSD that were not identified using conventional MRI. This paper focuses on the incidence and characteristics of the brain lesions found in NMOSD and the symptoms that they cause. Recent studies using advanced imaging techniques are also introduced. PMID:23259063

Kim, Woojun; Kim, Su-Hyun; Huh, So-Young; Kim, Ho Jin

2012-01-01

460

Control of Abnormal Synchronization in Neurological Disorders  

PubMed Central

In the nervous system, synchronization processes play an important role, e.g., in the context of information processing and motor control. However, pathological, excessive synchronization may strongly impair brain function and is a hallmark of several neurological disorders. This focused review addresses the question of how an abnormal neuronal synchronization can specifically be counteracted by invasive and non-invasive brain stimulation as, for instance, by deep brain stimulation for the treatment of Parkinson’s disease, or by acoustic stimulation for the treatment of tinnitus. On the example of coordinated reset (CR) neuromodulation, we illustrate how insights into the dynamics of complex systems contribute to successful model-based approaches, which use methods from synergetics, non-linear dynamics, and statistical physics, for the development of novel therapies for normalization of brain function and synaptic connectivity. Based on the intrinsic multistability of the neuronal populations induced by spike timing-dependent plasticity (STDP), CR neuromodulation utilizes the mutual interdependence between synaptic connectivity and dynamics of the neuronal networks in order to restore more physiological patterns of connectivity via desynchronization of neuronal activity. The very goal is to shift the neuronal population by stimulation from an abnormally coupled and synchronized state to a desynchronized regime with normalized synaptic connectivity, which significantly outlasts the stimulation cessation, so that long-lasting therapeutic effects can be achieved. PMID:25566174

Popovych, Oleksandr V.; Tass, Peter A.

2014-01-01

461

'Abnormalization' of ethnic minorities in conversation.  

PubMed

Social psychologists studying intergroup relations have shown a renewed interest in social norms. In doing so, norms are treated typically as a non-problematic given and independent of the actual practices people are involved in. This study examines the discursive construction and representation of abnormality by analysing discussions held by some ethnically Dutch inhabitants of old inner-city quarters in Rotterdam. It is shown how these people in focus-group type talk construct the behaviour of ethnic minority residents as 'abnormal' in a recognizable number of ways. They set the ethnic minority residents in contrast with 'obviously normal' practices; they use extreme case formulations in describing their behaviour; and they draw upon 'unarguable' human values in explaining their judgments. Further, specific versions of reality were constructed in providing a justificatory account of their assessment, and undermining cultural interpretations were managed by criticizing ethnic minority culture, questioning particular behaviour as an instance of culture, and arguing for the need for adaptation. PMID:11446230

Verkuyten, M

2001-06-01

462

What proportion of congenital abnormalities can be prevented?  

PubMed Central

OBJECTIVE--To estimate the proportion of preventable congenital abnormalities in Hungary. DESIGN--Analysis of available Hungarian data-bases and of the effectiveness of primary, secondary, and tertiary preventive methods. SETTING--Databases of ad hoc epidemiological studies and of the Hungarian congenital abnormality registry. MAIN OUTCOME MEASURES--Prevalence at birth and prevalence after prevention in 73 congenital abnormality types or groups. RESULTS--Preventive methods are available for 51 (70%) of the 73 congenital abnormality types or groups evaluated. The birth prevalence of all congenital abnormalities could be reduced from 65 to 26 per 1000; thus 39 per 1000 (60%) are preventable. Without congenital dislocation of the hip, which is unusually common in Hungary, the preventable proportion of congenital abnormalities is 52%. CONCLUSION--Many congenital abnormalities can be prevented, but as they do not represent a single pathological category there is no single strategy for their prevention. Images p502-a p503-a PMID:8448464

Czeizel, A E; Intôdy, Z; Modell, B

1993-01-01

463

Hepatic perfusion abnormalities during CT angiography: Detection and interpretation  

SciTech Connect

Twenty-seven perfusion abnormalities were detected in 17 of 50 patients who underwent computed tomographic angiography (CTA) of the liver. All but one of the perfusion abnormalities occurred in patients with primary or metastatic liver tumors. Perfusion abnormalities were lobar in nine cases, segmental in 11, and subsegmental in seven; 14 were hypoperfusion and 13 were hyperperfusion abnormalities. The causes for the abnormalities included nonperfusion of a replaced hepatic artery (n = 11), cirrhosis and nodular regeneration (n = 3), altered hepatic hemodynamics (e.g., siphoning, laminar flow) caused by tumor (n = 7), contrast media washout from a nonperfused vessel (n = 1), compression of adjacent hepatic parenchyma (n = 1), and unknown (n = 4). Differentiation of perfusion abnormalities from tumor usually can be made by comparing the morphology of the known tumor with the suspected perfusion abnormality, changes of each on delayed CTA scans, and review of initial angiograms and other imaging studies.

Freeny, P.C.; Marks, W.M.

1986-06-01

464

Prenatal diagnosis of limb abnormalities: role of fetal ultrasonography  

PubMed Central

Fetal ultrasonografy is the most important tool to provide prenatal diagnosis of fetal anomalies. The detection of limb abnormalities may be a complex problem if the correct diagnostic approch is not established. A careful description of the abnormality using the rigth nomenclature is the first step. Looking for other associated abnormalities is the threshold to suspect chromosomal abnormalities or single gene disorder. According to the patogenic point of view, limb abnormalities may be the result of malformation, deformation, or disruption. The prenatal diagnosis and the management of limb abnormalities involve a multidisciplinary team of ostetrician, radiologist/sonologist, clinical geneticist, neonatologist, and orthopedic surgeons to provide the parents with the information regarding etiology of the disorder, prognosis, option related to the pregnancy and recurrence risk for future pregnancies. The aim of this review is to describe the importance of detailed fetal ultrasonography in prenatal diagnosis of limb abnormalities. PMID:22439035

Ermito, Santina; Dinatale, Angela; Carrara, Sabina; Cavaliere, Alessandro; Imbruglia, Laura; Recupero, Stefania

2009-01-01

465

Stability analysis of abnormal multiplication of plankton using parameter identification technique  

NASA Astrophysics Data System (ADS)

This paper presents the mathematical approach for the abnormal multiplication of plankton. An abnormal multiplication can be expressed as an unstable problem and the stability of the system is investigated by introducing eigenvalues of a mathematical equation. The stability of the system can be judged by an eigenvalue based on the Lyapunov's stability theory. In this paper, the Arnoldi-QR method is used to obtain eigenvalues and eigenvectors of the system. The mode superposition method is employed to create spatial distribution needed to analyse the stability. To obtain the objective eigenvalue, the parameter identification technique is employed. The finite element method is used for the discretization in space. Lake Kasumigaura, which is located in Ibaraki Prefecture in Japan, is selected and actual data in 1975, 1976, 1991 and 2000 are used in order to investigate the stability of the specified lake in Japan.

Ohno, G.; Kawahara, M.

2004-01-01

466

Enhanced tissue integration of implantable electrodes for sensing, and stimulation, via radio frequency glow discharge  

NASA Astrophysics Data System (ADS)

Biopotential electrodes are conductive materials that convert electronic currents to or from ionic currents for sensing, and stimulating specific tissue sites for medical applications. Implanted electrodes become "walled off" by the foreign body tissue reactions producing poorly attached scar capsules dominated by surrounding dense collagenous lamellae and source fibroblasts which are electrically resistive. The conductive interstitial fluid that is typical between an electrode and the resistive capsule allows spurious current paths. The insulating layer increases the distance between the electrode and the target sites and poor attachment often results in electrode migration within the host tissue. This investigation tested the hypothesis that surface-energy modulation of electrodes, via Radio Frequency Glow Discharge Treatment (RFGDT), can improve the performance of tissue-implantable electrodes by reducing the foreign body tissue reaction and enhancing interfacial bonding between the tissue and electrode material. Previously published findings were reproduced in a pilot study of explanted reference grade medical-grade methyl silicone (PDMS) and commercially pure titanium (cpTi) materials and their tissue capsules from 30-day subcutaneous exposures in Balb/C mice. The low-critical surface tension PDMS produced thick, dense, poorly attached scar capsules while the higher-surface-energy commercially pure titanium (cpTi) produced more cellular and strongly attached tissue layers difficult to delaminate from the biomaterial. For the main body of work, cpTi, capacitor-grade Tantalum (Ta), and synthetic heart valve-quality Pyrolytic Carbon (PyC) were evaluated, representative of potential high-surface-energy implant electrode materials. Their surface characteristics were determined as-manufactured and after Radio Frequency Glow Discharge Treatment (RFGDT) by Critical Surface Tension (CST) measurement, Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and Electron Spectroscopy for Chemical Analysis (ESCA). Representative tissue/electrode interfaces were created through subcutaneous implantation and harvest from Balb/C mice after 7, 28 and 56 days. The recovered, formalin preserved conductive implant/tissue specimens were examined by Electrical Impedance Spectroscopy (EIS) over the range from 0.1 Hz to 100,000 Hz, in Bode plot and Nyquist plot formats. After EIS the implants were extracted from the tissue for surface examination by SEM and the separated tissue capsules were evaluated by histological examination in hematoxylin and eosin (H&E)-stained light microscopic thin sections. The differential findings were that the RFGDT PyC and Ta implants had significantly increased interface resistance and capacitance over their sterilized-only controls, correlating with more flattened cellular layers retained on the RFGDT specimens. The cpTi specimens, earlier identified as promoting hard tissue-to-surface integration in dental implants, showed only marginal improvements in soft tissue attachment following RFGDT. These experimental findings were confirmed through equivalent circuit modeling by the conversion from a standard Randles model with constant phase elements, which described the pre-implant materials, to a modified Randles model with additional resistance and capacitance to describe the implants with well-integrated surface coatings. Future work with RFGDT-modified electrode materials must include actual signal acquisition/stimulation trials in implant host tissues, to assess possible improvements in electrical energy-transfer efficiency and battery lifetime extensions.

O'Connor, Laurie M.

467

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

468

Determination of the Trapping Parameters of Glow Peaks of CAF2:DY(TLD-200) by Using Computer Glov Curve Deconcolution Method  

NASA Astrophysics Data System (ADS)

Computerized glow curve deconvolution method is used to determine the number of peaks, the order of kinetics b, the activation energy Ea,frequency factor s and number of the trapped electrons n0 associated with the glow peaks in single crystal of CaF2:Dy (TLD-200). Glow curve analysis indicate that the glow curve in the temperature region between room temperature and 250 oC can be best described as a superposition of six peaks. First five peaks are described by first-order kinetics and sixth peak general-order kinetic. The number of trapped electrons, activation energies and frequency factor for individual glow peaks are as follows: (Peak 1) 3x1013, 1.27 and 2.13x1017, (Peak 2) 6.3x1013, 1.01 and 9.2x1012, (Peak 3) 3.3x1014, 0.7 and 6.12x107, (Peak 4) 2.4x1014, 1.14 and 3.28x1012, (Peak 5) 1.5x1014, 0.84 and 2.56x108, (Peak 6) 2.4x1014, 0.98 and 1.76x109.

Yazici, A. Necmeddýn; Haciýbrahýmoðlu, M. Yakup

2001-05-01

469

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