WorldWideScience
1

Ozone layer  

Energy Technology Data Exchange (ETDEWEB)

Governments around the world will soon make decisions on policies that could determine the fate of the ozone layer-the Earth's shield from harmful ultraviolet radiation. The Vienna Convention for the Protection of the Ozone Layer, signed on March 22, 1985, created a framework for scientific cooperation and information exchange that will form the basis for a protocol for controlling substances thought to threaten the ozone layer. As of mid-1987, 29 countries had signed the Convention, including the major producers and users of chlorofluorocarbons (CFCs), the most important of suspect chemicals.

1987-12-01

2

The wavelength dependence of ultraviolet enhanced reactivation in a mammalian cell-virus system  

International Nuclear Information System (INIS)

The effect of UV radiation in the wavelength region 230 nm to 302 nm on the ability of an irradiated mammalian cell to reactivate UV-irradiated mammalian virus was tested. An action spectrum for radiation enhanced reactivation (RER) is presented. The shape of the action spectrum points to a combined nucleic acid-protein target for UV radiation effects on this cellular parameter. An analysis of the results of others involving the biochemical and photobiological events involved in RER does not allow us to distinguish which macromolecule is the major contributor to this effect. Studies involving an analogous phenomenon in bacteris (Weigle reactivation) imply that RER and WR amy involve similar mechanisms. (author).

4

Evolution of ultraviolet dwarfs  

Science.gov (United States)

UV dwarf star evolution, using central and gap star models emphasizing photoneutrino emission

1969-01-01

5

An in vitro model to test relative antioxidant potential: Ultraviolet-induced lipid peroxidation in liposomes  

International Nuclear Information System (INIS)

Since antioxidants have been shown to play a major role in preventing some of the effects of aging and photoaging in skin, it is important to study this phenomenon in a controlled manner. This was accomplished by developing a simple and reliable in vitro technique to assay antioxidant efficacy. Inhibition of peroxidation by antioxidants was used as a measure of relative antioxidant potential. Liposomes, high in polyunsaturated fatty acids (PUFA), were dispersed in buffer and irradiated with ultraviolet (UV) light. Irradiated liposomes exhibited a significantly higher amount of hydroperoxides than liposomes containing antioxidants in a dose- and concentration-dependent manner. Lipid peroxidation was determined spectrophotometrically by an increase in thiobarbituric acid reacting substances. To further substantiate the production of lipid peroxides, gas chromatography was used to measure a decrease in PUFA substrate. In order of decreasing ...

6

Suppression of pitting corrosion with passive film modification on type 304 stainless steel by ultra-violet light irradiation; Shigaikoshosha ni yoru Type 304 stainless ko no fudotai himaku kaishitsu to koshoku yokusei  

Energy Technology Data Exchange (ETDEWEB)

In this study, the effects of 325nm wavelength ultraviolet light irradiation on pitting corrosion behavior of type 340 stainless steel in a neutral chloride solution are studied. Further, the change of passive film with the light irradiation is analyzed using x-ray photoelectron spectroscopy. The mains results obtained therefrom are stated below. Pitting potential can be shifted in noble direction by the ultraviolet light irradiation. The effect of ultraviolet light irradiation is ore prominent in the pitting corrosion process than that in the passive film formation. The result of the analysis in terms of the birth and death stochastic probability process shows that pitting corrosion rate is decreased remarkably by the ultraviolet light irradiation at the formation of passive film, while the repassivation is slightly expedited by the ultraviolet light irradiation. On the other hand, ...

1998-06-20

7

Photosynthetic Response of Seagrasses to Ultraviolet-A Radiation and the Influence of Visible Light Intensity 1  

UK PubMed Central (United Kingdom)

Inhibition of photosynthesis by ultraviolet-A radiation (UV-A, 315-380 nanometers) was examined in three marine angiosperms: Halophila engelmannii Aschers, Halodule wrightii...Full Text Available

1982-02-01

10

Vacuum ultraviolet radiometry of xenon positive column discharges  

Energy Technology Data Exchange (ETDEWEB)

In order to judge the potential fluorescent lamp applications of various low-pressure positive column discharges it is necessary to measure the absolute power emitted in the ultraviolet region of the spectrum. For rare-gas discharges the principle emission occurs in the vacuum ultraviolet so that it is difficult to measure the radiant emittance (power per unit area) of the resonance radiation by standard methods. Two independent techniques are discussed for measuring the radiant emittance of positive column discharges in the vacuum ultraviolet. These techniques are used to study xenon positive column discharges at the resonance wavelength of 147 nm. The first method relies on the measurement of the resonance level density by absorption techniques. The effective decay rate of the resonance level is then determined by the simulation of resonance radiation transport. These two quantities are combined to yield the radiant ...

1995-10-01

11

f 07821-6004-R0-00 RESEARCH PROGRAM ON HOLOGRAPHIC - NASA ...  

Science.gov (United States)

in a KDP crystal fed with red light from a Q-s_tched ruby laser. One reason for interest in holograms made with ultraviolet ...

12

Test and Evaluation of Liquid Polymers for Use in Army ...  

Science.gov (United States)

... The addition of 0.5 pphr of fine thermal carbon black to the polymers gave good resistance to 500 hours of ultraviolet (UV) xposure in a Weather ...

1972-10-01

13

Remote Sensor Systems for Unmanned Planetary Missions  

Science.gov (United States)

instrument is shown in Figure 4-9 The incoming radiation is focused onto ...... An early rocket-borne ultraviolet spectrometer of the Ebert type by ...

14

Photoconductive ultraviolet detectors based on ZnO films  

British Library Electronic Table of Contents (United Kingdom)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8mA, and a slow photoresponse with a rise time of 5min and a decay time of 7min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the d...

2006-01-01

15

Simultaneous ultraviolet spectrophotometric determination of nitrate and nitrite in water  

Energy Technology Data Exchange (ETDEWEB)

A rapid and accurate method for the direct simultaneous determination of nitrate and nitrite is proposed. The method is applied to the determination of nitrate and nitrite in rainwater and wastewater without preliminary separation. The determinations are performed by a CPA matrix method with ultraviolet spectrophotometric detection. The results obtained are in agreement with those obtained by conventional methods for the determination of nitrate and nitrite.

1991-02-01

16

Electronic structure of the Ru(0001) surface  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with the electronic structure of ruthenium. Synchrotron radiation in the range from 15 to 45 eV and angle-resolved ultraviolet photoemission are used to map the energies of the electronic states. The Fermi surface of Ru is determined using angle-resolved ultraviolet photoemission spectroscopy. The experimental results are compared with calculated photoemission spectra obtained within the framework of the one-step model of photoemission. (author)

2000-03-13

17

Effect of UV radiation on the killer phenotype in the wine yeast-saccharomycetes and spontaneous variation of this character  

International Nuclear Information System (INIS)

Spontaneous and ultraviolet-induced changeabilities of wine yeasts from the killer state to sensitive one have been studied. Observed often spontaneous changes of killer and neutral phenotypes under laboratory store conditions as well as high mutation frequency of genetic elements responsible for the killer indication on ultraviolet irradiation testify that often encounterability in nature and in the production of sensitive yeasts is attributed to high frequency of mutation changes of the killer and neutral phenotypes to the sensitive state.

18

Absolute absorption of ozone in the midinfrared  

Energy Technology Data Exchange (ETDEWEB)

The absolute absorption of ozone in the midinfrared has been measured relative to 253.7-nm ultraviolet absorption to an accuracy of 1% using a Bruker Fourier transform spectrometer. These new results agree with previous measurements by diode laser measurements after the latter are corrected for more recent infrared calculations and ultraviolet cross sections. They also agree with a determination based on refractive index measurements in the infrared. 16 refs., 4 figs., 3 tabs.

1992-12-20

19

Scientific Assessment of Ozone Depletion: 2002. Pursuant to Article 6 of the Montreal Protocol on Substances that Deplete the Ozone Layer  

Science.gov (United States)

Since the Scientific Assessment of Ozone Depletion: 1998, numerous laboratory investigations, atmospheric observations, and theoretical and modeling studies have produced new key findings and have strengthened overall understanding of the ozone layer and its effect on ultraviolet (UV) radiation. These advances are highlighted in the following summary of the current understanding of the impact of human activities and natural phenomena on the ozone layer and the coupling of the ozone layer and the climate system. In the troposphere (i.e., lower atmosphere), observations show that the total combined effective abundance of ozone-depleting compounds continues to decline slowly from the peak that occurred in 1992-1994. Total chlorine is declining, while bromine from industrial halons is still increasing, albeit at a slower rate than was occurring previously (and as reported in the 1998 Assessment). Analyses of air trapped in snow since the late 19th century have ...

2003-01-01

20

Real-time optical modelling and investigation of inorganic nano-layer growth onto flexible polymeric substrates  

Energy Technology Data Exchange (ETDEWEB)

A major factor for the achievement of the desirable performance, efficiency and lifetime of flexible organic electronic devices is the optimization of the encapsulation layers that protect the device active layers by atmospheric gas molecule permeation. The active layers consisted of small molecule and/or polymer organic semiconductors as well as the organic conductors need to be encapsulated into a transparent medium that will provide the necessary protection and maintain their charge generation and transport characteristics. The encapsulation layers are generally consisted of inorganic thin films (silicon oxide-SiO{sub x} and aluminium oxide-AlO{sub x}) deposited onto the polymeric substrates, such as PolyEthylene Terephthalate (PET). In this work, in situ and real-time Spectroscopic Ellipsometry in the ultraviolet spectral region has been implemented in order to investigate the growth of inorganic SiO{sub x} and AlO{sub x} nano-layers onto ...

2010-01-15

21

PROBING THE ORIGINS OF THE C IV AND Fe K? BALDWIN EFFECTS  

International Nuclear Information System (INIS)

We use UV/optical and X-ray observations of 272 radio-quiet Type 1 active galactic nuclei and quasars to investigate the C IV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan Digital Sky Survey archives. The X-ray spectra are from the Chandra and XMM-Newton archives. We apply correlation and partial-correlation analyses to the equivalent widths (EWs), continuum monochromatic luminosities, and ?ox, which characterizes the relative X-ray to UV brightness. The EW of the C IV ?1549 emission line is correlated with both ?ox and luminosity. We find that by regressing l?(2500 A) with EW(C IV) and ?ox, we can obtain tighter correlations than by regressing l?(2500 A) with only EW(C IV). Both correlation and regression analyses imply that l?(2500 A) is not the only factor controlling the changes of EW(C IV); ?ox (or, equivalently, the soft X-ray emission) plays a fundamental role in the ...

2009-09-01

22

ARM AND INTERARM STAR FORMATION IN SPIRAL GALAXIES  

International Nuclear Information System (INIS)

We investigate the relationship between spiral arms and star formation in the grand-design spirals NGC 5194 and NGC 628 and in the flocculent spiral NGC 6946. Filtered maps of near-IR (3.6 #mu#m) emission allow us to identify 'arm regions' that should correspond to regions of stellar mass density enhancements. The two grand-design spirals show a clear two-armed structure, while NGC 6946 is more complex. We examine these arm and interarm regions, looking at maps that trace recent star formation-far-ultraviolet (GALEX NGS) and 24 #mu#m emission (Spitzer SINGS)-and cold gas-CO (HERACLES) and H I (THINGS). We find the star formation tracers and CO more concentrated in the spiral arms than the stellar 3.6 #mu#m flux. If we define the spiral arms as the 25% highest pixels in the filtered 3.6 #mu#m images, we find that the majority (60%) of star formation tracers occur in the interarm regions; this result persists qualitatively even when considering ...

2010-12-10

23

Selective absorption of ultraviolet laser energy by human atherosclerotic plaque treated with tetracycline  

Energy Technology Data Exchange (ETDEWEB)

Tetracycline is an antibiotic that absorbs ultraviolet light at 355 nm and preferentially binds to atherosclerotic plaque both in vitro and in vivo. Tetracycline-treated human cadaveric aorta was compared with untreated aorta using several techniques: absorptive spectrophotometry; and tissue uptake of radiolabeled tetracycline, which showed 4-fold greater uptake by atheroma than by normal vessel. In addition, intravenous tetracycline administered to patients undergoing vascular surgery demonstrated characteristic fluorescence in surgically excised diseased arteries. Because of tetracycline's unique properties, the authors exposed tetracycline-treated and untreated aorta to ultraviolet laser radiation at a wavelength of 355 nm. They found enhanced ablation of tetracycline-treated atheroma compared with untreated atheroma. The plaque ablation caused by ultraviolet laser radiation was twice as extensive in ...

1985-05-01

24

Contact lens disinfection by ultraviolet light  

Energy Technology Data Exchange (ETDEWEB)

A 253.7-nm ultraviolet light with an intensity of 1,100 microW/cm2 was tested for its germicidal activity against contact lenses and storage solutions contaminated with various corneal pathogens. The exposure time necessary to reduce a concentration of organisms from 10(6)/ml to less than 10/ml was 30 seconds for Staphylococcus aureus, 60 seconds for Pseudomonas aeruginosa, and 84 seconds for Candida albicans. The time necessary to sterilize a suspension of 10(4)/ml Acanthamoeba polyphaga was less than three minutes with this technique. Four brands of soft contact lenses were exposed to ultraviolet light for over eight hours without changing their appearance, comfort, or refraction.

1989-12-15

25

A proposed linac cavity rf drive system for the Los Alamos extreme ultraviolet free-electron laser  

Energy Technology Data Exchange (ETDEWEB)

Since 1979, scientists and engineers at the Los Alamos National Laboratory have designed, constructed, and operated a radio-frequency (RF) linac free-electron laser (FEL) at wavelengths from 9 to 45 /mu/m. Coupled with success of other research centers investigating wavelengths from the visible to far-infrared, Los Alamos is now proposing a vacuum-ultraviolet and soft x-ray (referred to henceforth as extreme ultraviolet, (XUV)) FEL oscillator/Self-Amplified Spontaneous Emission amplifier with beam energies ranging from 100 MeV to 1 GeV. This paper will focus on the first milestone of the proposed Los Alamos XUV project, i.e., a 250-MeV linac with approximately 50 mA of average current, producing photons with wavelengths below 1000 /angstrom/. 3 refs., 3 figs.

1989-01-01

26

UV renormalons in QCD and their phenomenological implications  

International Nuclear Information System (INIS)

I report on some recent work done in collaboration with E. de Rafael on the connection between ultraviolet renormalons in QCD and Nambu-Jona-Lasinio-like Lagrangians as its effective description at low energies. (orig.)

1998-05-01

27

The Goddard Library - Goddard Projects Directory - NASA  

Science.gov (United States)

Oct 2, 2007 ... The Payload combines some of the most sensitive particle sensors .... provide state-of-the-art measurements of incoming x-ray, ultraviolet, .... It will be launched into a low-Earth orbit on a Delta 7320 rocket in September 2004. ...

28

Sunbed use during adolescence and early adulthood is associated with increased risk of early-onset melanoma  

UK PubMed Central (United Kingdom)

Sunbed use is associated with increased risk of melanoma. Younger people might be more susceptible to the carcinogenic effects of ultraviolet radiation. We investigated the association between...Full Text Available

2011-05-01

29

Simultaneous Reactivation of Ultraviolet Damage in Xanthium Leaves 1  

UK PubMed Central (United Kingdom)

Experiments on Xanthium leaf discs were carried out to determine whether concomitant photoreactivation could be detected and if so, to compare its effects with photoreactivation due...Full Text Available

1969-12-01

30

Simulation study of chiral two dimensional ultraviolet (2DUV) spectroscopy of the protein backbone  

UK PubMed Central (United Kingdom)

Amide n –π* and π-π* excitations around 200 nm are prominent spectroscopic...Full Text Available

2010-06-09

31

Photoelectron spectroscopy of carbonyls: benzoic acid and its derivatives  

Energy Technology Data Exchange (ETDEWEB)

The ultraviolet photoelectron spectra of benzoic acid and 20 of its derivatives are presented. The low-energy regions of these spectra are deconvoluted and assigned using chemical substitution effects. 5 figures, 3 tables.

1981-01-01

32

Photoconductive ultraviolet detectors based on ZnO films  

Energy Technology Data Exchange (ETDEWEB)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant {tau} obtained from the curve fitting represents the ...

2006-12-15

33

Photoconductive ultraviolet detectors based on ZnO films  

International Nuclear Information System (INIS)

Properties of photoconductive ultraviolet detectors fabricated on ZnO films were presented. Highly c-axis oriented ZnO films were grown on glass substrates by pulsed laser deposition. Ultraviolet photodetectors were fabricated based on metal-semiconductor-metal planar structures. The photoresponsivity and the quantum efficiency are much higher in the ultraviolet range than in the visible range, and the peak values are around 360 nm. Photocurrent transients show that the detector has a large photocurrent with the peak value of 2.8 mA, and a slow photoresponse with a rise time of 5 min and a decay time of 7 min. The response curve of the detector is fitted well with exponential curve. The large photocurrent should result from the both effects of the accumulation of conduction electrons and the decrease of the barrier height between crystallites. The relaxation time constant #tau# obtained from the curve fitting represents the ...

2006-12-15

34

Lack of adequate sun protection for children with oculocutaneous albinism in South Africa  

UK PubMed Central (United Kingdom)

BackgroundChildhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the...Full Text Available

35

In vitro and in vivo estrogenicity of UV screens.  

UK PubMed Central (United Kingdom)

Ultraviolet (UV) screens are increasingly used as a result of growing concern about UV radiation and skin cancer; they are also added to cosmetics and other products for light stability. Recent data...Full Text Available

2001-03-01

36

Chemoprevention of Nonmelanoma Skin Cancer With Celecoxib: A Randomized, Double-Blind, Placebo-Controlled Trial  

UK PubMed Central (United Kingdom)

BackgroundPreclinical studies indicate that the enzyme cyclooxygenase 2 plays an important role in ultraviolet-induced skin cancers. We evaluated the efficacy and safety of celecoxib,...Full Text Available

2010-12-15

37

A rational vision of stratospheric ozone  

Energy Technology Data Exchange (ETDEWEB)

This work deals with a rational vision of stratospheric ozone including the threats on ozone layer, the verifications and the fears. After a recalling on the ozone layer history, the authors treats the question of the ultraviolets particularly the beneficial effects. Then an explanation of the ozone layer decrease is given. (O.L.). 29 refs., 6 figs.

1995-03-01

38

Ultraviolet radiation for the sterilization of contact lenses  

Energy Technology Data Exchange (ETDEWEB)

Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally ...

1990-10-01

39

Ultraviolet radiation for the sterilization of contact lenses  

International Nuclear Information System (INIS)

Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally ...

40

Extreme Ultraviolet Emission from Abell 4059  

CERN Document Server

We present the results of a search for Extreme Ultraviolet emission in A4059, a cluster with an X-ray emitting cluster gas. Our analysis of Extreme Ultraviolet Explorer (EUVE) Deep Survey observations of this cluster shows that it is associated with diffuse EUV emission. Outside the central 2 arcmin radius the entire EUV emission detected is explained by the low energy tail of the X-ray emitting gas. Within the central 2 arcmin region of the cluster we find a deficit of EUV emission compared to that expected from the X-ray gas. This flux deficit is discussed in the context of the cluster's cooling flow. The results derived for A4059 are compared to EUVE results obtained for other clusters such as Coma, Virgo, A1795, and A2199. As part of the study we have carried out a detailed investigation of the stability of the EUVE Deep Survey detector background. Based on long integrations of blank sky over 27 months we disprove claims of substantial time ...

2000-01-01

41

Ultraviolet-B Phototoxicity and Hypothetical Photomelanomagenesis: Intraocular and Crystalline Lens Photoprotection  

British Library Electronic Table of Contents (United Kingdom)

Purpose Ultraviolet-B (UV-B) radiation can cause phototoxic macular injuries in young people who have been sunbathing but not sungazing and in welders. Welders have a reportedly increased risk of uveal melanoma. We analyze phakic and pseudophakic risks for solar and welding arc UV-B exposure. Design Optical radiation measurement, analysis, and perspective. Methods Spectral transmittances were measured for UV-transmitting, UV-blocking, and blue-blocking intraocular lenses (IOLs). The photoprotective performances of crystalline and intraocular lenses were analyzed using relevant epidemiologic and laboratory data and action spectra for acute retinal phototoxicity and melanoma photocarcinogenesis. Results Crystalline lens UV-B retinal protection is deficient in children and young adults, incre...

2010-01-01

42

Ultraviolet detectors based on ZnO films by thermal oxidation of Zn metallic films  

British Library Electronic Table of Contents (United Kingdom)

Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 ?C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.

2008-01-01

43

Thin-film UV detectors based on hydrogenated amorphous silicon and its alloys  

Energy Technology Data Exchange (ETDEWEB)

Thin film ultraviolet detectors based on hydrogenated amorphous silicon alloys are realized with different diode structures (PIN, NIP, PN, and NP). The PIN and NIP detectors exhibit higher sensitivity in the ultraviolet spectrum and a significant lower dark current in comparison to the PN or NP structures. The best detector performance was achieved with a 33 nm thick PIN diode. This detector shows a maximum of quantum efficiency of 36.3% at a wavelength of 310 nm. By varying the thickness of the semi-transparent Ag front contact the selectivity of the detectors with the quantum efficiency peak at 320 nm can be adjusted. Thus, the spectral sensitivity of the detector shifts from a broad UV to a selective UV-B spectrum. (orig.)

2001-05-16

44

The VOISE Algorithm: a Versatile Tool for Automatic Segmentation of Astronomical Images  

CERN Document Server

The auroras on Jupiter and Saturn can be studied with a high sensitivity and resolution by the Hubble Space Telescope (HST) ultraviolet (UV) and far-ultraviolet (FUV) Space Telescope spectrograph (STIS) and Advanced Camera for Surveys (ACS) instruments. We present results of automatic detection and segmentation of Jupiter's auroral emissions as observed by HST ACS instrument with VOronoi Image SEgmentation (VOISE). VOISE is a dynamic algorithm for partitioning the underlying pixel grid of an image into regions according to a prescribed homogeneity criterion. The algorithm consists of an iterative procedure that dynamically constructs a tessellation of the image plane based on a Voronoi Diagram, until the intensity of the underlying image within each region is classified as homogeneous. The computed tessellations allow the extraction of quantitative information about the auroral features such as mean intensity, latitudinal and longitudinal ...

2009-01-01

45

Synthesis of ultraviolet curable encapsulating adhesives and their package applications for organic optoelectronic devices  

British Library Electronic Table of Contents (United Kingdom)

With conventional heating process, ultraviolet (UV) illumination, and microwave irradiation, we have successfully synthesized UV curable encapsulating adhesives with excellent gas barrier capabilities, good adhesive strength, moderate hardness, and high refractive indices. The experimental results manifest that the physical properties of lab-made encapsulating adhesives are highly dependent on their chemical structures and synthetic procedure. We also discover that the encapsulating adhesive prepared by microwave irradiation (i.e. encapsulating adhesive VI-MW) exhibits better adhesive strength and higher gas resistance than those prepared by conventional heating process and UV illumination. Furthermore, encapsulating adhesive VI-MW has also been applied for the package of organic light emi...

2011-01-01

46

Liquid chromatography with ultraviolet and dual parallel mass spectrometric detection for analysis of vitamin D in retail fortified orange juice  

British Library Electronic Table of Contents (United Kingdom)

Samples of vitamin D fortified orange juice obtained from retail food stores were analyzed for vitamin D3 content using a method developed by combining the best features of two AOAC methods. Detection by ultraviolet absorption at 265nm was compared to detection by selected ion monitoring (SIM) using atmospheric pressure chemical ionization (APCI) mass spectrometry (MS). Furthermore, an ion trap (IT) mass spectrometer was employed in a 'dual parallel MS' arrangement to simultaneously obtain qualitative APCI-ITMS data. The method was applied to 33 samples of 3 national American orange juice brands and 7 samples of 5 other American brands collected using a statistically designed sampling plan as part of the National Food and Nutrient Analysis Program to provide values for the USDA National Nu...

2011-01-01

47

FUV and X-ray absorption in the Warm-Hot Intergalactic Medium  

CERN Document Server

The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas collapsing in large-scale filaments and probably harbours a substantial fraction of the baryons in the local Universe. Absorption-line measurements in the ultraviolet (UV) and in the X-ray band currently represent the best method to study the WHIM at low redshifts. We here describe the physical properties of the WHIM and the concepts behind WHIM absorption line measurements of H I and high ions such as O VI, O VII, and O VIII in the far-ultraviolet and X-ray band. We review results of recent WHIM absorption line studies carried out with UV and X-ray satellites such as FUSE, HST, Chandra, and XMM-Newton and discuss their implications for our knowledge of the WHIM.

2008-01-01

48

Detection of Free-Living Amoebae in Some Water Sources and its Control by Ultraviolet- Radiation  

International Nuclear Information System (INIS)

Among the numerous free-living amoebae (FLA) of soil and water habitats, certain species belonging to two genera Acanthamoeba and Naegleria are facultative parasites of man.They cause disease called primary amoebic meningoencephalitis where history of contact with water was recorded in most of the cases especially with Naegleria species. The present work aimed to search for presence of free-living amoebae in the water and trials for its control by Ultraviolet-radiation (UV-radiation). Samples from different water sources were examined for the presence of free-living amoebae. These samples were cultured on non-nutrient agar streaked with bacteria. Amoebae were detected and identified by means of their morphological characters. Twelve positive cases of one hundred and twenty examined samples could be detected. The positive samples were exposed to different doses of UV-radiation for different times.

49

Composition and method for encapsulating photovoltaic devices  

Energy Technology Data Exchange (ETDEWEB)

A composition and method for encapsulating a photovoltaic device which minimizes discoloration of the encapsulant. The composition includes an ethylene-vinyl acetate encapsulant, a curing agent, an optional ultraviolet light stabilizer, and/or an optional antioxidant. The curing agent is preferably 1,1-di-(t-butylperoxy)-3,3,5-trimethylcyclohexane; the ultraviolet light stabilizer is bis-(N-octyloxy-tetramethyl) piperidinyl sebacate and the antioxidant is selected from the group consisting of tris (2,4-di-tert-butylphenyl) phosphite, tetrakis methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) methane, octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, and 2,2'-ethylidene bis(4,6-di-t-butylphenyl) fluorophosponite. The composition is applied to a solar cell then cured. The cured product contains a minimal concentration of curing-generated chromophores and resists UV-induced degradation.

2000-01-01

50

Characteristics of lanthanides in pyrochemical systems observed by electrochemical and spectrophotometric measurements  

Energy Technology Data Exchange (ETDEWEB)

As research for the chemical properties of lanthanide molecules in the dry system, electrochemical and ultraviolet-visible optical measurements on the chloride molten salt system have been conducted at Research Reactor Institute, Kyoto University. The reduction behavior of Ln(III)-Ln(0) and Ln(II) are measured on La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Yb by the cyclic voltammetry. The molar absorption coefficients of the f-f transition are measured by the measurement of ultraviolet-visible absorption spectra on Pr, Nd, Ho and Gd. From the comparison of the optical data between wet and dry systems, the characteristics of photon absorption are discussed in the molten salt. (H. Katsuta)

2001-12-01

51

Synthesis, characterization and optical properties of a high NIR reflecting yellow inorganic pigment: Mo"6"+ doped Y_2Ce_2O_7 as a cool colorant  

International Nuclear Information System (INIS)

Full text: Pigments possessing the ability to confer high solar reflectance have received considerable attention in recent years. The inorganic class of NIR reflective pigments are mainly metal oxides and are primarily employed in two applications: (i) visual camouflage and (ii) reducing heat build up. More than half of the solar radiation consists of near-infrared radiation (52%), the remaining being 43% visible light and 5% ultraviolet radiation. Over heating due to solar radiation negatively affects comfort in the built environment and contributes substantially to electrical consumption for air conditioning and release of green house gases. A pigment which has strong reflections in the NIR region (780-2500 nm) can be referred to as a 'cool' pigment. However, most of the NIR reflective inorganic pigments particularly yellow (eg. cadmium yellow, lead chromate, chrome titanate yellow etc.) contain toxic metals and hence their consumption is being limited. Replacing ...

2010-11-24

52

Temperature dependence of the performance of ultraviolet detectors  

Energy Technology Data Exchange (ETDEWEB)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric ...

2003-08-21

53

Temperature dependence of the performance of ultraviolet detectors  

International Nuclear Information System (INIS)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric ...

2003-08-21

54

Spectrophotometric technique quantitatively determines NaMBT inhibitor in ethylene glycol-water solutions  

Science.gov (United States)

Spectrophotometric method, using a ratio-recording ultraviolet-absorption spectrophotometer, permits analysis of NaMBT in ethylene glycol-water solutions with high accuracy. It reduces analysis time, requires smaller samples, and is able to detect extremely small concentrations of mercaptobenzothiazole.

1967-01-01

55

S179D prolactin diminishes the effects of UV light on epidermal gamma delta T cells  

UK PubMed Central (United Kingdom)

Epidermal gamma delta T cells (γδ T) and Langerhans cells (LC) are immune cells altered by exposure to ultraviolet radiation (UVB), a powerful stressor resulting in immune suppression....Full Text Available

2008-01-02

56

Rayleigh Scattering in Rare Gas Liquids  

CERN Document Server

The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the gas phase, except in the case of xenon for which measurements are available in the liquid. The scattering length mayplace constraints on the design of some large-scale detectors, using uv luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas mixtures is also discussed.

2002-01-01

57

Lamp system for uniform semiconductor wafer heating  

Energy Technology Data Exchange (ETDEWEB)

A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

2001-01-01

58

Conductive, spin-cast carbon films from polyacrylonitrile  

Energy Technology Data Exchange (ETDEWEB)

Polyacrylonitrile films have been spin cast and pyrolyzed to produce thin (500--1500 A) carbon films. These films have higher electrical conductivities than films produced by other methods at similar temperatures. The conductivity can be varied by at least four orders of magnitude by changing the pyrolysis temperature. Ultraviolet, infrared, and Raman spectroscopies were used to investigate the chemical structure of the films during different stages of processing.

1987-05-18

59

Clinical translation of ultraviolet autofluorescence microscopy towards endomicroscopy for early detection of cancer  

Science.gov (United States)

The non-invasiveness of autofluorescence technology may reduce sampling error and time delay for histopathology diagnosis. We establish biophotonic methods and guidelines to visualize and interpret early epithelial tissue changes that signify disease. Flexible and rigid fiber endomicroscopy instrumentation design parameters feasible for translation towards clinical use are in development.

2010-12-01

60

Calculation of general p-adic Feynman amplitude  

Energy Technology Data Exchange (ETDEWEB)

The general n-point massless p-adic Feynman amplitude with arbitrary parameters of analytic regularization for each line is calculated. This result is presented in the form of a sum over hierarchies of a given graph. The structure of ultraviolet and infrared divergences of p-adic Feynman amplitudes is characterized and the star-triangle uniqueness identity in the p-adic case is derived. (orig.).

1992-10-01

61

Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions  

International Nuclear Information System (INIS)

Ultraviolet (UV) upconversion (UC) luminescence in Yb3+/Er3+-codoped yttrium oxide (Y2O3) nanocrystals can be enhanced by orders of magnitude via tridoping further with Li+ ions under diode laser excitation of 970 nm. Sensitized three-photon UC radiations at 390 and 409 nm, corresponding to the 4G11/2?4I15/2 and 4H9/2?4I15/2 of Er3+ ions, respectively, present an enhancement time of about 33 times, which is larger than the 24 times enhancement for the UC green radiation. The UV UC radiation at 320 nm that corresponds to the 2P3/2?4I15/2 of Er3+ ions has also been greatly enhanced. Theoretical calculations interpret that all the observed enhancement times of UV UC radiations arise from the prolonged lifetimes of their intermediate states.

2009-03-01

62

Ultraviolet radiation in Finland  

Energy Technology Data Exchange (ETDEWEB)

Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s ...

1996-12-31

63

Space nuclear power requirements for ozone layer modification  

International Nuclear Information System (INIS)

This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O_3) in the Earth's atmosphere is estimated to be about 4.7 x 10"3"7 molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 x 10"3"1 molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time #approx# 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O_2 (leading to production of atomic oxygen, which can combine with O_2 to form O_3) than in ozone ...

1992-01-13

64

Second Byurakan spectral sky survey. II. Results for region centered on alpha 09h50m, delta +55 deg 00 arcmin  

Energy Technology Data Exchange (ETDEWEB)

The second list of objects in the Second Biurakan Spectral Sky Survey of the region centered on alpha 09h50m, delta +55 deg 00 arcmin is given. The list contains data on 110 objects and galaxies of a peculiar physical nature and 24 blue stars. The observations were made with the 40-52 arcsec Schmidt telescope of the Biurakan Astrophysical Observatory with a set of three objective prisms using Kodak IIIaJ and IIIaF emulsions sensitized in nitrogen. The area is found to contain 20 quasar candidates and four Seyfert galaxies, 27 blue stellar objects, 24 galaxies with an appreciable ultraviolet continuum, and 39 emission galaxies without appreciable ultraviolet radiation. The surface brightness of the quasars and Seyferts on the considered area down to the limiting magnitude 19.5 M is more than 1.5 per square degree with allowance for the already known quasars. The surface density of emission galaxies is about four per square degree. 7 references.

1984-07-01

65

Photobiological activity of marmesin (5-B-hydroxyisopropyl-4-5 dihydrofurocoumarin) in Chinese hamster V79 cells  

Energy Technology Data Exchange (ETDEWEB)

Marmesin was isolated from the medicinal plant, Afraegle paniculata. Its cytotoxicity and mutagenicity in Chinese hamster V79 cells when sensitized to near ultraviolet (NUV) and long wavelength ultraviolet light or black light (BL) were assayed. Marmesin was extremely cytotoxic in the dark. This cytotoxicity was photoenhanced in NUV and BL; the photoenhanced lethality being higher in NUV than in BL. The LD/sub 50/ of marmesin under NUV and BL photosensitization were 0.002 ..mu..M and (0.012 ..mu..M), respectively. In the absence of NUV and BL, marmesin's LD/sub 50/ was 0.013 ..mu..M.NUV and BL without marmesin were not significantly cytotoxic at the fluence rates of 0.29 W/m/sup 2/ and 4.2 W/m/sup 2/, respectively, for up to 20 min. In contrast to the observed high cytotoxicity of marmesin, its mutagenicity at the HGPRT locus (Asub(z)Gsup(r)) was weak. The implication of this result in the high incidence of skin cancer in Nigeria in ...

1983-10-01

66

Observation of the Far-ultraviolet Continuum Background with SPEAR/FIMS  

CERN Document Server

We present the general properties of the far-ultraviolet (FUV; 1370-1720A) continuum background over most of the sky, obtained with the Spectroscopy of Plasma Evolution from Astrophysical Radiation instrument (SPEAR, also known as FIMS), flown aboard the STSAT-1 satellite mission. We find that the diffuse FUV continuum intensity is well correlated with N_{HI}, 100 $\\mu$m, and H-alpha intensities but anti-correlated with soft X-ray. The strongest correlation is with the H-alpha emission, and the correlation of the diffuse background with the direct stellar flux is weaker than the correlation with other parameters. The continuum spectra are relatively flat. However, a weak softening of the FUV spectra toward some sight lines, mostly at high Galactic latitudes, is found not only in direct-stellar but also in diffuse background spectra. The diffuse background is relatively softer that the direct stellar spectrum. We also find that the diffuse FUV background averaged ...

2010-01-01

67

Multilayer reflective coatings for extreme-ultraviolet lithography  

Energy Technology Data Exchange (ETDEWEB)

Multilayer mirror coatings which reflect extreme ultraviolet (EUV) radiation are a key enabling technology for EUV lithography. Mo/Si multilayers with reflectances of 67.5% at 13.4 nm are now routinely achieved and reflectances of 70 2% at 11.4 nm were obtained with MO/Be multilayers. High reflectance is achieved with careful control of substrate quality, layer thicknesses, multilayer materials, interface quality, and surface termination. Reflectance and film stress were found to be stable relative to the requirements for application to EUV lithography. The run-to-run reproducibility of the reflectance peak position was characterized to be better than 0.2%, providing the required wavelength matching among the seven multilayer-coated mirrors used in the present lithography system design. Uniformity of coating was improved to better than 0.5% across 150 mm diameter substrates. These improvements in EUV multilayer mirror technology will enable us to meet the stringent ...

1998-03-10

68

Mitochondrial genetic damage induced in yeast by a photoactivated furocoumarin in combination with ethidium bromide or ultraviolet light  

International Nuclear Information System (INIS)

Ethidium bromide (EB) and ultraviolet light (UV) in combination are known to produce a synergistic induction of 'petite' mutants in yeast. Two other agents were combined with EB, 3-Carbethoxypsoralene (3 CPs) activated by 365 nm light or #gamma# rays. EB in combination with 3 CPs also resulted in an enhanced production of 'petite' mutants. After the photoaddition of 3 CPs in exponential phase cells, recovery of the 'petite' mutation during dark liquid holding was inhibited by the presence of EB producing an enhanced number of 'petite' mutants. The behavior of mitochondrial antibiotic resistance markers after individual and combined treatments with EB and 3 CPs indicates a random loss of markers after EB and a preferential loss of a certain region for the 3 CPs photoaddition. The combination of the two agents leads to an additivity of total drug marker losses rather than a synergistic loss. The combination of EB with #gamma# rays produced no enhancement in 'petite' ...

69

Low-temperature synthesis and room temperature ultraviolet lasing of nanocrystalline ZnO films  

Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline ZnO films were fabricated via a simple method involving the oxidation of Zn films at a remarkably low temperature of 380 C. X-ray diffraction study confirmed that the Zn films were completely oxidized even at the low temperature of 380 C and the ZnO films fabricated were of polycrystalline wurtzite structure. Room temperature optical pumping using a frequency-quintupled Q-switched Nd:YAG laser ({lambda}=213 nm) exhibited that sharp peaks at around 3.12 eV emerged above excitation powers of {proportional_to}7 MW/cm{sup 2}, demonstrating lasing in the ZnO films. These results represent that the process is a simple, promising approach for fabricating ZnO of sufficient optical performance for use as ultraviolet (UV) light emitters and an alternative UV laser source; both are key components in short-wavelength photonic devices. (orig.)

2005-02-01

70

FT-IR spectroscopic studies of polycyclic aromatic hydrocarbons  

International Nuclear Information System (INIS)

Proper assessment of the hypothesis which correlates polycyclic aromatic hydrocarbons (PAHs) with the unidentified infrared emission bands requires additional experimental laboratory data. In order to address this need, thermal infrared emission studies were performed on a subset of PAHs suggested to be of astrophysical importance. It was proposed that infrared emission from interstellar PAHs occurs following absorption of an ultraviolet photon. Since energy transfer to the ground electronic state can be rapid for a species in which intersystem crossing is negligible, the emission spectrum may be viewed as resulting from an equilibrium vibrational temperature (Leger and d'Hendecourt, 1987). This has been the basis for using infrared absorption spectra to calculate the corresponding emission spectra at various temperatures. These calculations were made using room temperature infrared absorption coefficients instead of those at the temperature of interest because of ...

1990-04-01

71

Detection of H2 Emission from Mira B in UV Spectra from the Hubble Space Telescope  

CERN Document Server

We present ultraviolet spectra of Mira's companion star from the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope (HST). The companion is generally assumed to be a white dwarf surrounded by an accretion disk fed by Mira's wind, which dominates the UV emission from the system. The STIS UV spectrum is dominated by numerous, narrow H2 lines fluoresced by H I Ly-alpha, which were not detected in any of the numerous observations of Mira B by the International Ultraviolet Explorer (IUE). The high temperature lines detected by IUE (e.g., C IV 1550) still exist in the STIS spectrum but with dramatically lower fluxes. The continuum fluxes in the STIS spectra are also much lower, being more than an order of magnitude lower than ever observed by IUE, and also an order of magnitude lower than fluxes observed in more recent HST Faint Object Camera objective prism spectra from 1995. Thus, the accretion rate onto Mira ...

2001-01-01

72

Vibrational Circular Dichroism: A developing spectroscopic technique for peptide and protein conformational studies  

International Nuclear Information System (INIS)

Electronic circular dichroism (ECD) of the n-#pi# and #pi# -#pi# transitions of the amide groups in the ultraviolet has become an indispensable tool for qualitative characterization of proteins in solution. Since the existence of such a spectrum (that is, of natural optical activity) comes from the three dimensional interaction of the chromophores in the molecule, CD is exquisitely sensitive to molecular conformation. However, in proteins, the amide transitions available in the near UV are limited in number and are broads and overlapping. Interactions among them yield information about the polymeric backbone, but since such amide electronic excitation are relatively delocalized, the resulting

1996-11-01

73

Ultraviolet Complete Electroweak Model Without a Higgs Particle  

CERN Document Server

An electroweak model with running coupling constants described by an energy dependent entire function is utraviolet complete and avoids unitarity violations for energies above 1 TeV. The action contains no physical scalar fields and no Higgs particle and the physical electroweak model fields are local and satisfy microcausality. The $W$ and $Z$ masses are compatible with a symmetry breaking $SU(2)_L\\times U(1)_Y \\rightarrow U(1)_{\\rm em}$, which retains a massless photon. The vertex couplings possess an energy scale $\\Lambda_W > 1$ TeV predicting scattering amplitudes that can be tested at the LHC.

2010-01-01

74

Two-Loop Virtual Corrections to Drell-Yan Production at order alpha_s alpha^3  

CERN Document Server

The Drell-Yan mechanism for the production of lepton pairs is one of the most basic processes for physics studies at hadron colliders. It is therefore important to have accurate theoretical predictions. In this work we compute the two-loop virtual mixed QCD x QED corrections to Drell-Yan production. We evaluate the Feynman diagrams by decomposing the amplitudes into a set of known master integrals and their coefficients, which allows us to derive an analytical result. We also perform a detailed study of the ultraviolet and infrared structure of the two-loop amplitude and the corresponding poles in epsilon.

2011-01-01

75

Tunable VUV generation by anti-Stokes stimulated Raman conversion of XeCl laser radiation  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on the results of experiments into efficient higher-order anti-Stokes Raman conversion of tunable short-pulse XeCl laser radiation. The maximum output energy of the pumping laser, in which the radiation of a frequency-doubled dye laser is amplified by two XeCl laser amplifiers, is 55 mJ with a pulse duration of 1 ns FWHM. Using hydrogen gas as a Raman medium, a series of anti-Stokes lines up to the 12th order (121.5 nm) is generated in the vacuum ultraviolet (VUV) region. 16 references.

1987-06-01

76

Spectroscopy of color centers in yttrium-aluminium perovskite crystals  

International Nuclear Information System (INIS)

The color centers, which are generated in yttrium-aluminium perovskite (YAP):Nd(1 at.%) and YAP:Er(50 at.%) crystals under the influence of ultraviolet and #gamma#-irradiation, have been studied by absorption spectroscopy. The generated color centers are both stable and transient at room temperature. It is shown that the transient color centers are mainly responsible for the decrease of laser generation efficiency of Nd:YAP and YAP:Er irradiated crystals, although physical mechanisms leading to efficiency decrease are different in these materials. (orig.)

1998-07-24

77

Solid-state ozone synthesis by energetic ions  

International Nuclear Information System (INIS)

We have synthesized ozone by irradiating thin solid films of oxygen and oxygen-water mixtures with 100 keV protons, motivated by recent reports of condensed O_3 on icy satellites in the outer Solar system. We measured the depth of the Hartley absorption band in the ultraviolet by reflectance spectroscopy and used it to quantify the column density of ozone. We analyzed the results using a three-component (O, O_2 and O_3) model that successfully explains the fluence dependence of ozone production.

1999-08-02

78

Photoluminescence and cathodoluminescence properties of Tb3+ activated Sr3AlO4F emitting-color tunable phosphor  

British Library Electronic Table of Contents (United Kingdom)

Tb3+-activated Sr3AlO4F phosphors were synthesized by a high-temperature solid-state reaction method. The investigation of photoluminescence and cathodoluminescence indicates that these phosphors can be effectively excited by ultraviolet light and low-voltage electron beam. The phosphors exhibit a tunable-green emission. The luminescence behaviors are explained by the site occupancy of Tb3+ ions in the host crystal and the cross-relaxation of 5D3 to 5D4 state.

2011-01-01

79

Photoluminescence and cathodoluminescence properties of Tb3+ activated Sr3AlO4F emitting-color tunable phosphor  

Science.gov (United States)

Tb3+-activated Sr3AlO4F phosphors were synthesized by a high-temperature solid-state reaction method. The investigation of photoluminescence and cathodoluminescence indicates that these phosphors can be effectively excited by ultraviolet light and low-voltage electron beam. The phosphors exhibit a tunable-green emission. The luminescence behaviors are explained by the site occupancy of Tb3+ ions in the host crystal and the cross-relaxation of 5D3 to 5D4 state.

2011-03-01

80

Photochemical generation of E' centre from Si-H in amorphous SiO2 under pulsed ultraviolet laser radiation  

CERN Document Server

In situ optical absorption spectroscopy was used to study the generation of E' centres in amorphous SiO_2 occurring by photo-induced breaking of Si-H groups under 4.7eV pulsed laser radiation. The dependence from laser intensity of the defect generation rate is consistent with a two-photon mechanism for Si-H rupture, while the growth and the saturation of the defects are conditioned by their concurrent annealing due to reaction with mobile hydrogen arising from the same precursor. A rate equation is proposed to model the kinetics of the defects and tested on experimental data.

2006-01-01

81

Partial inhibition of in vitro pollen germination by simulated solar ultraviolet-B radiation  

Energy Technology Data Exchange (ETDEWEB)

Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined.

1984-01-01

82

Optimum plasma conditions for the efficient high-order harmonic generation in platinum plasma  

International Nuclear Information System (INIS)

We studied the optimum plasma conditions that are required for efficient high-order harmonic generation in platinum plume. Harmonics up to the 49th order (?=16.32 nm) are analyzed under various conditions of laser-plasma interaction. Time-resolved ultraviolet spectra of platinum plasma at both optimum and nonoptimum conditions of harmonic generation are presented. We calculated the ionization states of the plasma, free electron density, and singly charged ion density at different prepulse intensities and compared them with experimental results.

2007-06-01

83

Lasing below 200 nm in the NIJI-IV compact storage-ring-based free electron laser  

International Nuclear Information System (INIS)

Laser gain of the NIJI-IV compact storage-ring-based Free Electron Laser (FEL) system at AIST reached #approx#9% at 200 nm for an average beam current of 16.3 mA. In addition to such a drastic gain enhancement, improvement of the laser-cavity performance has led to successful FEL lasing in the vacuum ultraviolet below 200 nm even in a compact system. Temporal and spectral characteristics of the NIJI-IV FEL were examined around 200 nm. FEL performance will be briefly discussed from the application point of view.

2004-08-01

84

Endomicroscopy imaging of epithelial structures using tissue autofluorescence  

Science.gov (United States)

We explore autofluorescence endomicroscopy as a potential tool for real-time visualization of epithelial tissue microstructure and organization in a clinical setting. The design parameters are explored using two experimental systems--an Olympus Medical Systems Corp. stand-alone clinical prototype probe, and a custom built bench-top rigid fiber conduit prototype. Both systems entail ultraviolet excitation at 266 nm and/or 325 nm using compact laser sources. Preliminary results using ex vivo animal and human tissue specimens suggest that this technology can be translated toward in vivo application to address the need for real-time histology.

2011-04-01

85

Emission Line Spectra in the Soft X-Ray Region 20-75 (Angstrom)  

Energy Technology Data Exchange (ETDEWEB)

As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.

2002-06-18

86

Pharmacological optimization of tissue perfusion  

UK PubMed Central (United Kingdom)

After fluid resuscitation, vasoactive drug treatment represents the major cornerstone for correcting any major impairment of the circulation. However, debate still rages as to the choice of agent, dose,...Full Text Available

2009-07-01

87

Instrumentation for Materials Research - Major Instrumentation Projects  

Science.gov (United States)

... Materials Research - Major Instrumentation Project (IMR-MIP) program in the Division of Materials ... for materials preparation and characterization essential for researchers studying materials in a ...

88

FORMATION EPOCHS, STAR FORMATION HISTORIES, AND SIZES OF MASSIVE EARLY-TYPE GALAXIES IN CLUSTER AND FIELD ENVIRONMENTS AT z = 1.2: INSIGHTS FROM THE REST-FRAME ULTRAVIOLET  

International Nuclear Information System (INIS)

We derive stellar masses, ages, and star formation histories (SFHs) of massive early-type galaxies in the z = 1.237 RDCS1252.9-2927 cluster and compare them with those measured in a similarly mass-selected sample of field contemporaries drawn from the Great Observatories Origin Deep Survey South Field. Robust estimates of these parameters are obtained by comparing a large grid of composite stellar population models with 8-9 band photometry in the rest-frame near-ultraviolet, optical, and IR, thus sampling the entire relevant domain of emission of the different stellar populations. Additionally, we present new, deep U-band photometry of both fields, giving access to the critical far-ultraviolet rest frame, in order to empirically constrain the dependence of the most recent star formation processes on the environment. We also analyze the morphological properties of both samples to examine the dependence of their scaling relations on their mass ...

2010-01-20

89

Scarus fuscopurpureus (Purple-brown Parrotfish)  

Science.gov (United States)

... widely distributed from the Red Sea to the Arabian Gulf region and there are no known major threats. It ... ...

92

Wastewater treatment; Abwasserreinigung  

Energy Technology Data Exchange (ETDEWEB)

The methods introduced for the field of cleaning waste water can be classified under various processes. Chemical oxidation is done with ozone, hydrogen peroxide and ultraviolet irradiation with subsequent biological decomposition. Another method is ultra-filtration with recovery of valuable materials or waste water ponds with algae biomass to decompose ammonium compounds, nitrates and phosphates. (EF) [Deutsch] Die auf dem Gebiet der Abwasserreinigung vorgestellten Methoden kann man in verschiedene Verfahren einordnen. Die chemische Oxidation erfolgt mit Ozon, Wasserstoff-Peroxid, UV Bestrahlung und anschliessenden biologischen Abbau. Eine andere Methode ist die Ultrafiltration mit Rueckgewinnung von Wertstoffen oder Abwasserteiche mit Algenbiomasse zum Abbau von Ammoniumverbindungen, Nitraten und Phosphaten. (EF)

1994-11-01

93

Use of polarized light microscopy in porcine reproductive technologies  

British Library Electronic Table of Contents (United Kingdom)

The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) could be useful for a non-invasive evaluation of the meiotic spindle and may allow removal of nuclear structures without fluorochrome staining and ultraviolet exposure. In this study, PLM was used to assess its potential application in porcine reproductive technologies. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein in in vitro-matured porcine oocytes; to examine its effects on the oocyte developmental competence; to select oocytes based on the presence of the meiotic spindle detected by PLM; and to assess the efficiency oocyte enucleation assisted...

2011-01-01

94

Upper bound for a three-photon excitation cross section in atomic argon in the ultraviolet regime  

International Nuclear Information System (INIS)

A scheme of evaluating a generalized three-photon excitation cross section #sigma#/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p"6 "1S_0 state to the 3p"54s'[1/2]_1"0 state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of #DELTA##lambda#/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is #sigma#/sub (3)/ = 1.414 x 10/sup -80/ cm"6 s"2. .AE.

8800-01-01

95

UV inactivation: Combined effects of UV radiation and xenobiotics in two strains of Saccharomyces  

International Nuclear Information System (INIS)

The effects of eight chemicals on the inactivation rate of ultraviolet radiation on the colony building capabilities of two strains of Saccharomyces cervisae - a wild type strain and a mutant deficient in excision repair - were studied. The insecticide methoxychlor, the herbicide 2,4-dichlorophenoxyacetic acid, the fungicide pentachlorophenol and its metabolite tetrachlorohydroquinone, as well as the chemicals acrylonitrile and 2,3-dichloro-1-propene have no significant impact on the effects of UV radiation in Saccharomyces cerevisae. Depending on the concentration, trichloroethylene increases the sensitivity to UV radiation. The herbicide paraquat provides efficient protection against UV radiation at concentrations where a toxic effect cannot be observed even without UV. The results were rather similar for both strains. (orig.).

96

UPS fine structures of highest occupied band in vanadyl-phthalocyanine ultrathin film  

Energy Technology Data Exchange (ETDEWEB)

Ultraviolet photoelectron spectra were measured for vanadyl phthalocyanine (VOPc) ultrathin films prepared on graphite to study effects of the molecular orientation and the electric dipole layer on the organic electronic states. VOPc has a permanent electric dipole perpendicular to the molecular plane, hence a well-defined electric dipole layer could be intentionally prepared by using the oriented monolayer. The observed binding-energy difference of the highest occupied molecular orbital (HOMO) bands between the oriented monolayer and the double layer was found to agree with the vacuum level shift, leading to a conclusion that the molecular energy level with respect to the substrate Fermi level is changed when the molecule is in the electric dipole layer.

2005-06-15

97

Survival of gas phase amino acids and nucleobases in space radiation conditions  

CERN Document Server

We present experimental studies on the photoionization and photodissociation processes (photodestruction) of gaseous amino acids and nucleobases in interstellar and interplanetary radiation conditions analogs. The measurements have been undertaken at the Brazilian Synchrotron Light Laboratory (LNLS), employing vacuum ultraviolet (VUV) and soft X-ray photons. The experimental set up basically consists of a time-of-flight mass spectrometer kept under high vacuum conditions. Mass spectra were obtained using photoelectron photoion coincidence technique. We have shown that the amino acids are effectively more destroyed (up to 70-80%) by the stellar radiation than the nucleobases, mainly in the VUV. Since polycyclic aromatic hydrocarbons have the same survival capability and seem to be ubiquitous in the ISM, it is not unreasonable to predict that nucleobases could survive in the interstellar medium and/or in comets, even as a stable cation.

2008-01-01

98

Stabilizing effect of the electron-beam self-fields on the phase-space trajectory in a self-amplified spontaneous emission free-electron laser operating in ultraviolet and x-ray spectral ranges  

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the FEL interaction grows exponentially.

2004-02-28

99

Specific features and mechanisms of photoluminescence of nanostructured silicon carbide films grown on silicon in vacuum  

British Library Electronic Table of Contents (United Kingdom)

The light-emitting properties of cubic silicon carbide films grown by vacuum vapor phase epitaxy on Si(100) and Si(111) substrates under conditions of decreased growth temperatures (T gr ? 900?700?C) have been discussed. Structural investigations have revealed a nanocrystalline structure and, simultaneously, a homogeneity of the phase composition of the grown 3C-SiC films. Photoluminescence spectra of these structures under excitation of the electronic subsystem by a helium-cadmium laser (?excit = 325 nm) are characterized by a rather intense luminescence band with the maximum shifted toward the ultraviolet (?3 eV) region of the spectral range. It has been found that the integral curve of photoluminescence at low temperatures of measurements is split into a set of Lorentzian components. Th...

2011-01-01

100

Signatures of extra dimensions at e{gamma} and {gamma}{gamma} colliders  

Energy Technology Data Exchange (ETDEWEB)

The authors study the processes {gamma}e {r{underscore}arrow} {gamma}e and {gamma}{gamma} {r{underscore}arrow} {gamma}{gamma}, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff M{sub S} {approximately} 1 TeV for the effective gravity theory, the cross sections obtained for these processes at the Next Linear Collider (NLC), with the e{gamma} an {gamma}{gamma} options, deviate from the predictions of the Standard Model significantly. The results suggest that, for typical proposed NLC energies and luminosities, the predictions of WSQG can be tested in the range 1 TeV {approx{underscore}lt} M{sub S} {approx{underscore}lt} 10 TeV, making e{gamma} an {gamma}{gamma} colliders important tools for probing WSQG.

2000-01-26

101

Schottky barrier modulation on silicon nanowires  

Science.gov (United States)

Oxide charge on the sidewalls of SiO{sub 2} embedded silicon wires with 20x20 nm{sup 2} cross section is shown to influence the Schottky barrier height for Pd{sub 2}Si/Si junctions positioned on the end surfaces of the wires. Compared with results on planar silicon surfaces, the electron barrier height is 0.3 eV lower for wires investigated as fabricated. By increasing the oxide charge through irradiation by ultraviolet light, the electron barrier decreases by an additional 0.15 eV and the hole barrier correspondingly increases by about the same amount. The phenomenon is explained by assuming an oxide charge density in the range of 10{sup 12} cm{sup -2}.

2007-03-26

102

Quadrant anode image sensor  

Science.gov (United States)

A position-sensitive event-counting electronic readout system for microchannel plates (MCPs) is described that offers the advantages of high spatial resolution and fast time resolution. The technique relies upon a four-quadrant electron-collecting anode located behind the output face of the microchannel plate, so that the electron cloud from each detected event is partly intercepted by each of the four quadrants. The relative amounts of charge collected by each quadrant depend on event position, permitting each event to be localized with two ratio circuits. A prototype quadrant anode system for ion, electron, and extreme ultraviolet imaging is described. The spatial resolution achieved, approx. =10 ..mu.., allows individual MCP channels to be distinguished. (AIP)

1976-11-01

103

Quadrant anode image sensor  

International Nuclear Information System (INIS)

A position-sensitive event-counting electronic readout system for microchannel plates (MCPs) is described that offers the advantages of high spatial resolution and fast time resolution. The technique relies upon a four-quadrant electron-collecting anode located behind the output face of the microchannel plate, so that the electron cloud from each detected event is partly intercepted by each of the four quadrants. The relative amounts of charge collected by each quadrant depend on event position, permitting each event to be localized with two ratio circuits. A prototype quadrant anode system for ion, electron, and extreme ultraviolet imaging is described. The spatial resolution achieved, approx. =10 #mu#, allows individual MCP channels to be distinguished.

9472-01-01

104

Positive effects of UV radiation on a calanoid copepod in a transparent lake: do competition, predation or food availability play a role?  

British Library Electronic Table of Contents (United Kingdom)

Zooplankton tolerant to ultraviolet radiation (UVR) could be indirectly affected by UVR through interactions with UV-sensitive species in the same ecosystem. In Lake Giles, Pennsylvania, USA, the calanoid copepod Leptodiaptomus minutus is more UVR tolerant than the cohabiting species Daphnia catawba and Cyclops scutifer. We asked whether L. minutus is affected by UV-induced mortality of a food competitor (D. catawba) or a predator of its nauplii (C. scutifer). We conducted two in situ enclosure experiments with six treatments: L. minutus alone, L . minutus + Daphnia and L. minutus + Cyclops in the presence and absence of UVR. There were few differences in survival among treatments in Experiment 1, which had enhanced food and a cumulative UVR (320 nm) dose of 9.3 kJ m-2. In Experiment 2, wh...

2006-01-01

105

Photosensitization by drugs. [Ultraviolet radiation  

Science.gov (United States)

uv irradiation (365 nm) of air-saturated methanol solutions of 20 drugs absorbing in the 300 to 400 nm region gave rise to oxygen uptake, as determined with a polarographic oxygen electrode. The drugs were tested for photosensitizing capability by either a Type I (free radical) or a Type II (single molecular oxygen) mechanism. This testing was done by the inclusion of either acrylamide or 2,5-dimethylfuran in the irradiated drug solution, with observation of the subsequent polymerization or oxidation, respectively. Phenothiazine and thiazide derivatives appear capable of photosensitization by both mechanisms; promethazine, trifluoperazine, and furosemide show relatively high reactivity. Diazepam (weak), hexachlorophene, aminacrine, pyrilamine, tetracycline, demeclocyline, quinine, and anthracene (strong) react only by a Type II mechanism, with a photosensitizing efficiency increasing in the order given. A correlation appears to exist with reports of in vivo photosensitivity.

1977-09-01

106

Photohemolytic potency of tetracyclines  

Energy Technology Data Exchange (ETDEWEB)

Hemolysis induced by long-wave ultraviolet radiation (UVA) and 8 different commercial tetracycline derivatives was studied in a model using human red blood cells. Demethylchlortetracycline and doxycycline were shown to have pronounced hemolytic properties causing 88% and 85% hemolysis, respectively, at a concentration of 50 micrograms/ml and 72 J/ cm2 of UVA. Tetracycline, oxytetracycline, and chlortetracycline caused maximally 18% hemolysis at 200 micrograms/ml and lymecycline only 7% at 100 micrograms/ml. Methacycline showed intermediate hemolytic effect of 36% at 200 micrograms/ml. Minocycline had no hemolytic effect whatsoever. These experimental data correlate very well with clinical reports and comparative phototoxicity trials in humans. Photohemolysis may thus be of value for predicting tetracycline phototoxicity.

1985-04-01

107

Mechanism of the accumulation effect in laser damage to polymers: appearance of microdamage due to an ionization absorption wave  

Energy Technology Data Exchange (ETDEWEB)

An investigation was made of the accumulation of laser damage to transparent polymers irradiated with nanosecond pulses from neodymium and ruby lasers. The damage was investigated by the method of scattering and luminescence in the visible and near ultraviolet parts of the spectrum. It was established that there were two stages in laser damage by repeated irradiation with pulses of intensity below the single-shot damage threshold. An absorbing defect evolved during the first stage in such a way as to create a thermal instability in the surrounding matrix. During the second stage this thermal instability caused spatial growth of laser damage because of propagation of an ionization-inducing absorption wave with a front traveling at the rate governed by the electron component of the thermal conductivity.

1984-04-01

108

Luminescence properties of Ca- and Yb-codoped SiAlON phosphors  

International Nuclear Information System (INIS)

Luminescence properties of SiAlON phosphors codoped with Ca and Yb were investigated by changing the host lattice composition. These modifications of the host lattice were obtained by replacing Si-N bonds by Al-N and Al-O bonds. Their photoluminescence (PL) and cathodoluminescence (CL) properties were measured and compared with each other. PL allows observing the influence of the host lattice modifications by measuring wider areas. CL can excite all luminescent centers, in particular the UV luminescence centers, even if their amount is small. Thus, two additional peaks in the ultraviolet and infrared regions were observed in CL, which is not observed by PL. This work suggests that the combination of PL and CL gives more understanding about the luminescence of SiAlON phosphors, in particular the role of the secondary phases on their properties.

2008-01-15

109

Low temperature deposition and characterization of TiO{sub 2} photocatalytic film through cold spray  

Energy Technology Data Exchange (ETDEWEB)

Cold spray was employed as a novel low temperature approach to deposit titanium dioxide (TiO{sub 2}) photocatalytic film. The film microstructure was characterized using X-ray diffraction and scanning electron microscopy. The photocatalytic performance was examined through acetaldehyde degradation under ultraviolet illumination. Results showed that TiO{sub 2} film was successfully deposited on substrate surface through cold spray. The film thickness reached up to 15 {mu}m. The film presented a rough surface and porous structure. Owing to the low temperature of spray powder, no phase and particle size changes occurred to TiO{sub 2} during deposition. It was found that the cold-sprayed TiO{sub 2} film was active for photodegradation of acetaldehyde.

2008-04-30

110

Kinetics of the methylparathion hydrolysis in aqueous medium; Cinetica de la hidrolisis del metilparation en medio acuoso  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of alkaline hydrolysis of methylparathion was studied at different temperatures (0-50 Centigrade) in the p H range of 8-12 by ultraviolet-visible absorption spectroscopy. Optimum p H and wavelength conditions were defined to carry out the simultaneous determination of methylparathion and one of its hydrolysis product, paranitrophenol, in buffered aqueous medium. Based on the experimental data and the mathematical equation of the kinetics, a rate constant (k) of first-order and an activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author) activation energy (Ea) of 9.2 Kcal/mol, were estimated. (Author)

1997-12-31

111

Investigating the Ultraviolet Properties of Gravity with a Wilsonian Renormalization Group Equation  

CERN Document Server

We review and extend in several directions recent results on the asymptotic safety approach to quantum gravity. The central issue in this approach is the search of a Fixed Point having suitable properties, and the tool that is used is a type of Wilsonian renormalization group equation. We begin by discussing various cutoff schemes, i.e. ways of implementing the Wilsonian cutoff procedure. We compare the beta functions of the gravitational couplings obtained with different schemes, studying first the contribution of matter fields and then the so-called Einstein-Hilbert truncation, where only the cosmological constant and Newton's constant are retained. In this context we make connection with old results, in particular we reproduce the results of the epsilon expansion and the perturbative one loop divergences. We then apply the Renormalization Group to higher derivative gravity. In the case of a general action quadratic in curvature we recover, within certain approximations, the known ...

2008-01-01

112

Intrinsic fluorescence of the amniotic fluid  

International Nuclear Information System (INIS)

The intrinsic fluorescence of clear amniotic fluid from third-trimester pregnancy is reported. The fluorescence intensity peaked at 405 nm when excited by ultraviolet light in the range of 310 to 360 nm. All of the 33 samples tested fluoresced, and their emission spectrum had the same shape, varying only in magnitude. Changing sample temperature (20 to 50 C) and sample pH (7.2 to 7.7) had little effect on the emission spectrum. The same fluorescence, with higher intensity, was observed when some newborn urine was tested. The fluorescence of amniotic fluid may provide a new tool to determine fetal age, fetal organ maturation, and fetal distress. (author).

1981-01-01

113

High power testing of a 17 GHz photocathode RF gun  

Energy Technology Data Exchange (ETDEWEB)

The authors report experimental results on a high gradient 17 GHz RF photocathode gun. The photocathode RF gun is a novel electron beam source intended to meet the requirements set by future high-energy linear colliders and next generation free electron lasers. A coupled pair of pillbox TM{sub 010}-like resonators is excited by sidewall coupled microwaves at 17 GHz. A picosecond ultraviolet laser pulse illuminates one wall of the structure at the axis of symmetry. Electrons are released by the photoelectric effect and are accelerated by the electric field of the microwaves in the cavity. The high frequency of operation raises the RF breakdown limit allowing strong electric fields to be used. In turn, the intense fields result in rapid acceleration of the electrons to relativistic speeds and reduced space charge induced emittance growth.

1996-12-31

114

Green synthesis of iron nanoparticles and their application as a Fenton-like catalyst for the degradation of aqueous cationic and anionic dyes  

British Library Electronic Table of Contents (United Kingdom)

Iron nanoparticles were produced using extracts of green tea leaves (GT-Fe NPs). The materials were characterized using TEM, SEM/EDX, XPS, XRD, and FTIR techniques and were shown to contain mainly iron oxide and iron oxohydroxide. The obtained nanoparticles were then utilized as a Fenton-like catalyst for decolorization of aqueous solutions containing methylene blue (MB) and methyl orange (MO) dyes. The related experiments investigated the removal kinetics and the effect of concentration for both MB and MO. The concentrations of dyes in aqueous solution were monitored using ultraviolet-visible (UV-vis) spectroscopy. The results indicated fast removal of the dyes with the kinetic data of MB following a second order removal rate, while those of MO were closer to a first order removal rate. T...

2011-01-01

115

Extended Conjugation in Polyaniline Like Structure Prepared by Plasma Polymerization Suitable for Optoelectronic Applications  

British Library Electronic Table of Contents (United Kingdom)

Plasma polymerization of aniline is carried out in a radiofrequency plasma reactor and the effect of polymerization time is examined in the structural, optical and optoelectronic properties of deposited films. Conjugated structures of polyaniline like films are obtained with unique and broad optical absorption band in the ultraviolet and entire visible region. The width of the absorption band increases and hence the optical band gap decreases with polymerization time. The optical constants are extracted by Swanepoel method and the optical dispersion parameters are determined by employing the Wemple-DiDomenico single oscillator model. The films exhibit similar thermal stability in air and argon atmosphere in the region of interest for optoelectronic applications. The photoluminescence study...

2011-01-01

116

Exploring the binding of the strong organic acceptor F{sub 4}TCNQ to coinage metals  

Energy Technology Data Exchange (ETDEWEB)

Organic/metal interface properties are of high interest for the application of molecular (sub)monolayers to modify surface properties. They are applied for, e.g., molecular electronics, chemical sensing, or the tuning of injection barriers in organic electronic devices. We present a joint theoretical and experimental study of F{sub 4}TCNQ adsorbed on Cu(111). The electronic and structural properties were determined by ultraviolet photoelectron spectroscopy (UPS) and X-ray standing wave (XSW) measurements. To better understand the complex process of binding, we modelled the system using density-functional theory. We find forward-donation from the lone pairs of the molecule into metallic states and back-donation from the metal into the LUMO of the molecule. The data on Cu(111) are compared to F4TCNQ on Au(111) and Ag(111) as well as to investigations of pyrenetetraone on various coinage metals.

2008-07-01

117

Determination of molar extinction coefficients #epsilon#_m(Ce"4"+) of Ce"4"+-Ce"3"+ dosimetric system  

International Nuclear Information System (INIS)

#epsilon#_m(Ce"4"+) values of the ceric-cereus system have been measured and the experimental procedure is described. Both routine titration method and electrochemical measurement were used. Some interference factors, such as ultraviolet, acidity and temperature, were studied as well. The temperature coefficient of #epsilon#_m(Ce"4"+) value in this experiment is about -0.1% degree C"-"1. A statistic analysis was made for 24 experimental values of #epsilon#_m(Ce"4"+) and a Gaussian distribution was found. Ultimately, an average molar extinction coefficient of 553.2 +- 1.3 m"2#centre dot#mol"-"1 was obtained at #approx#320 nm in 0.4 mol/L H_2SO_4 system, with a relative standard deviation of 0.24% (95% confidence level) and a total uncertainty of 1.5%.

1996-01-01

118

Design considerations for the magnetic system of a prototype x-ray free electron laser  

Energy Technology Data Exchange (ETDEWEB)

A number of difficult technical challenges need to be solved in the fields of accelerator and free-electron laser (FEL) technologies in order to build an X-ray FEL. One of the tasks well suited to the Advanced Photon Source Low Energy Undulator Test Line (LEUTL) is to take the intermediate step of solving some of the problems of single-pass FEL operation in the ultraviolet range. The existing Advanced Photon Source (APS) linac, in addition to its role of supply positrons for the APS storage ring, will also be used to generate the particle beam for the LEUTL. Here, the design of the magnetic system for the high gain soft x-ray free electron laser is described.

1997-04-01

119

Construction and development of a UV free electron laser under the cooperation of Nihon U, KEK, PNC, ETL and Tohoku U  

Energy Technology Data Exchange (ETDEWEB)

The construction and the development of a UV free electron laser have been started under the cooperation of Nihon U, KEK, PNC, ETL and Tohaku U. The project requires a 100MeV S-band electron linear accelerator to expand the oscillation of FEL using fundamental mode to the UV region. The injection system consists of a thermionic RF-gun with a LaB cathode and an {alpha} magnet for magnetic bunching. We are studying to reduce the back-bombardment electrons to realize the macropulse length of 20{mu}sec. Electron beams, up to the energy of 100MeV, are injected into the optical oscillators. Changing the accelerating energy and/or undulator parameters, this system will cover the range from infrared to ultraviolet for the applications in various fields.

1995-12-31

120

Conceptual design of industrial free electron laser using superconducting accelerator  

International Nuclear Information System (INIS)

Paper presents conceptual design of free electron laser (FEL) complex for industrial applications. The FEL complex consists of three. FEL oscillators with the optical output spanning the infrared (IR) and ultraviolet (UV) wave-lengths (#lambda# = 0.3...20 #mu#m) and with the average output power 10 - 20 kW. The driving beam for the FELs is produced by a superconducting accelerator. The electron beam is transported to the FELs via three beam lines (125 MeV and 2 x 250 MeV). Peculiar feature of the proposed complex is a high efficiency of the. FEL oscillators, up to 20 %. This becomes possible due to the use of quasi-continuous electron beam and the use of the time-dependent undulator tapering.

1995-08-21

121

Clinical and experimental studies of octocrylene's allergenic potency  

British Library Electronic Table of Contents (United Kingdom)

Background. Reports of positive patch test and photopatch test reactions to the chemical ultraviolet filter octocrylene have increased during the last decade. Little is known about the reason for octocrylene's allergenic activity. Objectives. To present and discuss the results of patch tests and photopatch tests with octocrylene, and to investigate the possible cause of its allergenic properties. Methods. Results of patch tests and photopatch tests with octocrylene in patients with adverse skin reactions to sunscreen products and/or ketoprofen were collected. The allergenic potency of octocrylene was investigated in the murine local lymph node assay (LLNA). Chemical reactivity assays were used to mimic octocrylene's interaction with biomolecules. Results. We report 23 cases of positive tes...

2011-01-01

122

Chemical transformations of organic matter during the composting of wood industry wastes (residues); Transformacoes quimicas da materia organica durante a compostagem de residuos da industria madeireira  

Energy Technology Data Exchange (ETDEWEB)

Composting of sawdust and paper mill sludge, using a 'Kneer' process reactor, was studied in an attempt to elaborate upon organic matter transformation during the process and to define parameters to measure the compost maturity level. Temperature, electron paramagnetic resonance data, ash and C, H, N and S contents, and a spectroscopic method using ultraviolet-visible (UV-VIS) for alkaline (pH = 8.5) and solid samples was used to study the maturity of the compost samples. These parameters were measured in 6 humic acids extracted from the compost samples during 29 days. The results of this work show that the 'Kneer' process is efficient in transforming ligno-celulitic residues in a short time (29 days), into an organic fertilizer material with application perspectives (author)

2004-06-01

123

Broad-linewidth laser absorption measurements of oxygen between 211 and 235nm at high temperatures  

British Library Electronic Table of Contents (United Kingdom)

Absorption coefficient data are presented for molecular oxygen at temperatures between 1100 and 2000K and discrete wavelengths between 211 and 235nm. Measurements were made behind reflected shock waves using broad-linewidth ultraviolet laser radiation generated from a frequency-quadrupled, tunable, pulsed Ti:Sapphire laser. Test mixtures consisting of 15% O"2, 15% He and balance Ar were used to minimize the influence of vibrational relaxation on the reflected shock temperature. The experimental results are in good agreement with theoretical calculations and confirm that discrete features from the Schumann-Runge system dominate between 211 and 235nm at temperatures higher than 1100K.

2011-01-01

124

Bonding and microstructural stability in Ni55Ti45 studied by experimental and theoretical methods  

Energy Technology Data Exchange (ETDEWEB)

Spiral orbit tribometry friction tests performed on Ni-rich Ni55Ti45 titanium ball bearings indicate that this alloy is a promising candidate for future aerospace bearing applications. Microstructural characterization of the bearing specimens was performed using transmission electron microscopy and energy dispersive spectroscopy, with NiTi, Ni4Ti3, Ni3Ti, and Ni2Ti4Ox phases identified within the microstructure of the alloy. Density functional theory was applied to predict the electronic structure of the NixTiy phases, including the band structure and site projected density of states. Ultraviolet photoemission spectroscopy was used to verify the density of states results from the density functional theory calculations, with good agreement observed between experiment and theory.

2010-11-25

125

Asphalt emulsion sealing of uranium mill tailings. 1980 annual report  

International Nuclear Information System (INIS)

Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.

126

Application of asphalt emulsion seals to uranium mill tailings  

International Nuclear Information System (INIS)

Studies of asphalt emulsion sealants have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to less than background levels. Field tests at the tailings pile in Grand Junction, Colorado confirmed that an 8-cm admix seal containing 22 wt % asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and conpacted, overburden was applied over the seal to protect the seal from ultraviolet degradation. 14 figures.

127

Anisotropic forming of magnetic powders mixed with ultraviolet resin; Shigaisen koka jushi wo mochiita jisei funmatsu no haiko seikei  

Energy Technology Data Exchange (ETDEWEB)

For the purpose of solving the limitations such as shape and dimension for magnetic compact fabricated by conventional anisotropic forming under magnetic orienting field, the feasibility of a new magnetic forming process was studied. Ferrite powder mixed with UV resin was compacted in the die mold and followed by alignment under the magnetic field. Effects of viscosity of UV resin and forming condition on magnetic characteristics of the compact was investigated. Maximum degree of alignment for the ferrite powder reached to 0.826. It was predicted that the proposed method had make it possible to fabricate a high performance magnet having the anisotropic alignment of the magnetic powder. The UV resin is desirable to have low viscosity, good properties such as formability and configuration stability for the compact and also parting- ability between the metal mold and the compact. (author)

1999-01-15

128

Amperometric biosensor for hydrogen peroxide based on horseradish peroxidase onto gold nanowires and TiO2 nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

An electrochemical biosensor for determination of hydrogen peroxide (H2O2) was fabricated, based on the electrostatic immobilization of horseradish peroxidase (HRP) with one-dimensional gold nanowires (Au NWs) and TiO2 nanoparticles (nano-TiO2) on a gold electrode. The nano-TiO2 can give a biocompatible microenvironment and compact film, and the Au NWs can provide fast electron transferring rate and greatly add the amount of HRP molecules immobilized on the electrode surface. Au NWs were characterized by ultraviolet?visible spectra and transmission electron microscope. The electrode modification process was probed by cyclic voltammetry and electrochemical impedance spectroscopy. Chronoamperometry was used to study the electrochemical performance of the resulting biosensor. Under optimal co...

2011-01-01

129

AlxGa1-xN/GaN multi-quantum-well ultraviolet detector based on p-i-n heterostructures  

British Library Electronic Table of Contents (United Kingdom)

We report on characterization of a set of AlGaN/GaN multiple-quantum-well (MQW) photodetectors. The model structure used in the calculation is the p-i-n heterojunction with 20 AlGaN/GaN MQW structures in i-region. The MQW structures have 2nm GaN quantum well width and 15nm AlxGa1-xN barrier width. The cutoff wavelength of the MQW photodetectors can be tuned by adjusting the well width and barrier height. Including the polarization field effects, on increasing Al mole fraction, the transition energy decreases, the total noise increases, and the responsivity has a red shift, and so the detectivity decreases and has a red shift.

2009-01-01

130

Advanced oxidation process based on ozone/electron beam irradiation for treating groundwater  

International Nuclear Information System (INIS)

There are several methods of generating OH free radicals from ozone and/or hydrogen peroxide and ultraviolet light. They all have in common that the OH free radicals originate in one single source only whereas in the combination of ozone with ionizing radiation two simultaneous working sources for the OH free radicals exist. The resulting higher OH free radical concentration makes this process especially apt for the remediation of low level contaminated groundwater as for example trichloroethylene (TCE) contamination in the sub-ppm range. A cost comparison between O_3/UV and O_3/electron beam for remediation of a groundwater contaminated with 100 ppb TCE indicated that for a throughput of about 5 million gallons/day the O_3/electron beam process is more cost-effective. (authors).

131

A novel electrochemical alkylation of aniline with methanol over Zn/Cu salts modified kaolin  

British Library Electronic Table of Contents (United Kingdom)

A novel liquid phase alkylation of aniline with methanol over Zn/Cu salts modified kaolin assisted with a pair of porous carbon electrode in slurry-bed reactor under constant current intensity, room temperature and atmospheric pressure was reported. The Zn/Cu salts modified kaolin catalysts were synthesized and characterized by infrared spectrometer (IR), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM), which showed that the transition metals were completely supported on kaolins structure and formed a pored one. The effect parameters, such as initial pH, electrolysis time, metal ratio with kaolin and salts composition in this electrochemical catalytic system, were studied. The procedure was inspected by ultraviolet-visible spectrum (UV-vis), and the product distributi...

2008-01-01

132

Study on effectiveness of transfusion program in thalassemia major patients receiving multiple blood transfusions at a transfusion centre in Western India  

UK PubMed Central (United Kingdom)

Background:Children suffering from beta-thalassemia major require repeated blood transfusions which may be associated with dangers like iron overload and contraction of...Full Text Available

2010-07-01

133

Scaling up prevention programmes to reduce the sexual transmission of HIV in China  

UK PubMed Central (United Kingdom)

Background Since 2007, sex has been the major mode of HIV transmission in China, accounting for 75% of new infections in 2009. Reducing sexual transmission is a major challenge for China...Full Text Available

2010-12-01

134

Response conflict and frontocingulate dysfunction in unmedicated participants with Major Depression  

UK PubMed Central (United Kingdom)

Individuals with major depressive disorder (MDD) often exhibit impaired executive function, particularly in experimental tasks that involve response conflict and require adaptive behavioral...Full Text Available

2008-10-01

135

Penicillinase-producing Neisseria gonorrhoeae in California. Report of a major outbreak and control recommendations.  

UK PubMed Central (United Kingdom)

A major outbreak of penicillinase-producing Neisseria gonorrhoeae occurred in California beginning in late 1986. After a state public health emergency was declared in April 1987, a statewide, cooperative...Full Text Available

1989-09-01

136

OECD Pakistan Aid Statistics  

Science.gov (United States)

Profile of aid statistics to Pakistan. Shows the amount of aid received, the major donors and the form in which the majority of the aid is given. Especially useful when compared to the aid profile of similar countries. Shows that ODA accounts for about 1.5% of Pakistani GDP and that it is distributed over various sectors.

137

Major inducing factors of hypertensive complications and the interventions required to reduce their prevalence: an epidemiological study of hypertension in a rural population in China  

UK PubMed Central (United Kingdom)

BackgroundThe complications of hypertension cause severe health problems in rural areas in China. We (i) screened the major factors inducing hypertensive complications and provided...Full Text Available

138

Major evolutionary transitions in ant agriculture  

UK PubMed Central (United Kingdom)

Agriculture is a specialized form of symbiosis that is known to have evolved in only four animal groups: humans, bark beetles, termites, and ants. Here, we reconstruct the major evolutionary transitions...Full Text Available

2008-04-08

139

Lectin Binding of the Major Polar Tube Protein (PTP1) and its Role in Invasion  

Science.gov (United States)

... 2003)050[0600:LBOTMP]2.0.CO;2 Lectin Binding of the Major Polar Tube Protein (PTP1) ... PTP1. We, therefore, undertook a study ...

140

Inhibition of the visual cycle by A2E through direct interaction with RPE65 and implications in Stargardt disease  

UK PubMed Central (United Kingdom)

Stargardt disease (STGD) is the major form of inherited juvenile macular degeneration. Pyridinium bis-retinoid A2E is a major component of lipofuscin which accumulates in retinal pigment epithelium...Full Text Available

2010-10-12

141

Influence of major histocompatibility complex genotype on mating success in a free-ranging reptile population  

UK PubMed Central (United Kingdom)

Major histocompatibility complex (MHC) genes are highly polymorphic components of the vertebrate immune system, which play a key role in pathogen resistance. MHC genes may also function as odour-related...Full Text Available

2009-05-07

142

Functional significance of UDP-glucuronosyltransferase (UGT) variants in the metabolism of active tamoxifen metabolites  

UK PubMed Central (United Kingdom)

Tamoxifen (TAM) is a selective estrogen receptor modulator widely used in the prevention and treatment of breast cancer. A major mode of metabolism of the major active metabolites of TAM, 4-OH-TAM...Full Text Available

2009-03-01

143

Extended-release Trazodone in Major Depressive Disorder  

UK PubMed Central (United Kingdom)

Objective: To investigate the efficacy, safety, and clinical benefit of a once-daily formulation of trazodone (Trazodone Contramid® OAD) in the treatment of major depressive...Full Text Available

144

Exact moment of tendon of pectoralis major muscle rupture captured on video  

UK PubMed Central (United Kingdom)

A powerlifting athlete ruptured his left tendon of the pectoralis major muscle while attempting to lift 160 kg in a Brazilian bench press championship. The injury seemed to occur in the concentric...Full Text Available

2007-09-01

145

Amastigote stage-specific monoclonal antibodies against Leishmania major.  

UK PubMed Central (United Kingdom)

Monoclonal antibodies were produced against gamma-irradiated amastigotes of Leishmania major. Five antibodies (T16 through T20) were selected which reacted in enzyme-linked immunoassays with the intracellular...Full Text Available

1989-12-01

146

A genome-wide survey of Major Histocompatibility Complex (MHC) genes and their paralogues in zebrafish  

UK PubMed Central (United Kingdom)

BackgroundThe genomic organisation of the Major Histocompatibility Complex (MHC) varies greatly between different vertebrates. In mammals, the classical MHC consists of a large number...Full Text Available

147

White dwarfs  

Energy Technology Data Exchange (ETDEWEB)

A large majority of stars and their lines are white dwarfs, the ultimate stellar stage whose structure and properties still fascinate astrophysicists.

1985-04-01

149

Status and Challenges of the LHC Construction  

CERN Document Server

The LHC is designed to provide proton beams of 7 TeV and nominal luminosity of 10**34 cm**-2s**-1. This objective is achieved at an affordable cost by pushing all major collider components to the limits of technology, by upgrading the existing CERN accelerators and infrastructure, and by involving the technical expertise, resources and dedication of accelerator laboratories world-wide. Following a decade of intensive R&D and technical validation of major collider systems, the LHC construction is now fully underway. Major industrial contracts have been awarded and are in execution for the procurement of the magnet, cryogenics and other systems. In this report, the status of the design and construction of the major LHC systems is presented.

2001-01-01

150

Pros, Cons, and Alternatives to Weight Based Cost Estimating  

Science.gov (United States)

Many cost estimating tools use weight as a major parameter in projecting the cost. This is often

2011-01-01

151

Microsoft Word - June 11 Profile.doc  

Wastenet

These pipeline networks transport gas from WA's major onshore transmission pipelines to commercial and residential customers in

152

Lessons from the past and prospects for the future  

Energy Technology Data Exchange (ETDEWEB)

The author presents his impressions of the conference - that is - major lessons as presented in the talks on nonlinearities and their role in condensed matter physics. (WRF)

1986-05-04

153

Determination of major metals and their trace states in ground water in Lebanon  

International Nuclear Information System (INIS)

1999 p. 148 Lebanon Saad, Zeinab Commission Libanaise d'Energie Atomique,

1999-11-02

154

Control of Effluent Gases from Solid Waste Processing Using Carbon Nanotubes  

Science.gov (United States)

One of the major problems associated with solid waste processing technologies is the release of

2005-01-01

155

Coefficient of Variation Spectral Analysis: An Application to ...  

Science.gov (United States)

... A major problem in the analysis of power spectral density measurements is distinguishing between narrowband spectral components of interest ...

1983-05-03

156

Brochure 1 - NASA  

Science.gov (United States)

exposed to persistent saltwater intrusion, a major factor in the decline of marsh ecosystems. The resulting increase in salinity from persistent flooding due to ...

159

Chemical and Immunological characterization of the major structural protein (p28) of MMC-1, a rhesus monkey endogenous type C virus: homology with the major structural protein of avian reticuloendotheliosis virus.  

UK PubMed Central (United Kingdom)

The major core protein (p28) of MMC-1, an endogenous type C virus of the rhesus monkey (Macaca mulatta), was purified and subjected to structural and immunological analyses. The NH2-terminal amino acid...Full Text Available

1981-09-01

160

Associations of major bleeding and myocardial infarction with the incidence and timing of mortality in patients presenting with non-ST-elevation acute coronary syndromes: a risk model from the ACUITY trial  

UK PubMed Central (United Kingdom)

AimsTo evaluate the associations of myocardial infarction (MI) and major bleeding with 1-year mortality. Both MI and major bleeding predict 1-year mortality in patients presenting...Full Text Available

2009-06-01

161

Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)  

Energy Technology Data Exchange (ETDEWEB)

Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has a merit to mitigate heat effect of the first EUV mirror. The fabrication method has another merit to control not only density ...

2006-06-15

162

Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)  

International Nuclear Information System (INIS)

Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has a merit to mitigate heat effect of the first EUV mirror. The fabrication method has another merit to control not only density ...

2006-06-01

163

Some relationships between ultraviolet light and heme-protein-induced peroxidative lipid breakdown in liposomes, as reflected by fluorescence changes: the effect of negative surface charge  

International Nuclear Information System (INIS)

The water soluble, photolabile nitrene precursor, azidonaphthalene-2,7-disulfonic acid (ANDS) was encapsulated in small unilamellar, isoelectric (egg PC) or negatively charged (egg PC + dihexadecylphosphate) liposomes. The individual and combined effects of heme-proteins and UV irradiation on the fluorescence of these vesicles under aerobic conditions were studied. Consistent with the catalytic action of heme-proteins on lipid peroxidation and peroxide decomposition, addition of cytochrome c (positively charged) or catalase (negatively charged) to the vesicles elicited immediate formation of a fluorescence band at 470 nm, characteristic of Schiff bases that form from aldehyde byproducts of decomposing hydroperoxides. Ultraviolet irradiation of liposomes caused no significant changes in the fluorescence spectrum, in spite of the radiolysis of ANDS inside the vesicles with consequent formation of nitrene radicals. When isoelectric vesicles were irradiated with UV ...

164

Physical, biochemical and physiological effects of ultraviolet radiation on Brassica napus and Phaseolus vulgaris  

International Nuclear Information System (INIS)

In order to follow some of the changes induced by ultraviolet-B (UV-B, 280-320 nm) radiation in Phaseolus vulgaris and Brassica napus, experiments were designed to localize sites of changes in leaves and to correlate some of the physiological and biochemical changes with penetration of UV-B radiation. B.napus was exposed to 8.9 kJ m"-"2 day"-"1 biologically effective UV-B radiation (UV-B_B_E). The penetration of UV-B radiation into the leaf was followed using a quartz fibre optic microprobe. Monochromatic radiation at 310 nm was decreased by ca 50 and 34% in the adaxial and abaxial epidermis, respectively, in plants not exposed to UV-B, whereas the radiation was decreased by ca 70 and 42%, respectively, in the same region in UV-treated plants. Polychromatic radiation showed a wavelength dependent change mainly for the collimated radiation. The results correlated with the distribution of phenolic compounds analysed from 40 #mu#m paradermal leaf sections. The first ...

1991-11-05

165

Photoresponsivity of ultraviolet detectors based on In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloys  

Energy Technology Data Exchange (ETDEWEB)

We describe the growth, fabrication, and characterization of an ultraviolet (UV) photoconductive detector based on In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloy that is lattice matched to GaN. The detector consisted of 0.1 {mu}m In{sub x}Al{sub y}Ga{sub 1-x-y}N alloy grown on 0.5-1.0 {mu}m GaN epilayer by metalorganic chemical vapor deposition. With varying indium concentration, the cut-off wavelength of the In{sub x}Al{sub y}Ga{sub 1-x-y}N detectors could be varied to the deep UV range. The most important and intriguing result is that the responsivity of the In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloy exceeded that of AlGaN alloy of a comparable cutoff wavelength by a factor of five. This makes the nitride quaternary alloy very important material for solar blind UV detectors applications particularly in the deep UV range where Al rich AlGaN alloys have problems with low quantum efficiency and cracks due in part to lattice mismatch with GaN. The ...

2000-08-07

166

Photoresponsivity of ultraviolet detectors based on In_xAl_yGa_1_-_x_-_yN quaternary alloys  

International Nuclear Information System (INIS)

We describe the growth, fabrication, and characterization of an ultraviolet (UV) photoconductive detector based on In_xAl_yGa_1_-_x_-_yN quaternary alloy that is lattice matched to GaN. The detector consisted of 0.1 #mu#m In_xAl_yGa_1_-_x_-_yN alloy grown on 0.5-1.0 #mu#m GaN epilayer by metalorganic chemical vapor deposition. With varying indium concentration, the cut-off wavelength of the In_xAl_yGa_1_-_x_-_yN detectors could be varied to the deep UV range. The most important and intriguing result is that the responsivity of the In_xAl_yGa_1_-_x_-_yN quaternary alloy exceeded that of AlGaN alloy of a comparable cutoff wavelength by a factor of five. This makes the nitride quaternary alloy very important material for solar blind UV detectors applications particularly in the deep UV range where Al rich AlGaN alloys have problems with low quantum efficiency and cracks due in part to lattice mismatch with GaN. The advantages of In_xAl_yGa_1_-_x_-_yN quaternary over ...

2000-08-07

167

Ozone Layer Observations  

Science.gov (United States)

The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV ...

2002-01-01

168

Organ culture of mammalian skin and the effects of ultraviolet light and testosterone on melanocyte morphology and function  

Science.gov (United States)

Scrotal skin of black Long-Evans rats and human thigh skin were maintained in vitro as organ cultures for as long as 14 days, and examined histologically using the combined skin splitting and Dopa techniques. Selected rat skin cultures received testosterone in the culture medium and/or were irradiated with ultraviolet light (290 to 320 nm uvl). With increased time in culture, scrotal melanocytes round up and there is an increase in epidermal pigmentation. Human skin behaves similarly; after eight days in vitro human melanocytes also become rounded, but remain strongly Dopa-positive. Addition of exogenous testosterone to cultured rat skin maintains dendritic morphology of melanocytes, but cell body size is still reduced. uvl irradiation stimulates melanocytes in rat skin cultures, maintaining their dendritic morphology and increasing epidermal and dermal pigmentation. Cultured skin receiving both uvl and testosterone illustrates a synergistic effect. Electron ...

1978-05-01

169

Measurement of the population densities in Gd atomic vapor using diode laser absorption spectroscopy in UV transitions  

International Nuclear Information System (INIS)

We report on the ultraviolet laser absorption spectroscopy of atomic Gd at 394-554 nm where two transition lines are place very closely by using a frequency-doubled beam of external-cavity diode laser (ECDL). One is from 999.121 to 26337.071 cm-1 and the other from 0 to 25337.755 cm-1. If two transition lines are placed closely within a continuous fine tuning range, the real-time measurement of the atomic excitation temperature is possible without any significant time consumption because at least two transition lines originating from different low-lying energy levels need to be investigated for the Boltzmann-plot. Since the spectral difference between the two transitions is only about 0.195 cm-1 (5.85 GHz), it is possible to record both the absorption spectra simultaneously as shown in Fig. 1. But the transition probabilities (or oscillator strengths) of these lines have not been measured accurately yet to the best of our knowledge. We report on the newly measured ...

2003-11-07

170

Laser-assisted solar cell metallization processing. Quarterly report, September 13-December 12, 1983  

Energy Technology Data Exchange (ETDEWEB)

The Westinghouse Electric Corporation has undertaken to investigate, develop, and characterize laser-assisted processing techniques utilized to produce the fine line, thin metal grid structures that are required to fabricate high-efficiency solar cells. Two basic techniques for metal deposition will be investigated, as follows: (1) photochemical decomposition of liquid or gas phase organometallic compounds utilizing either a focused, CW ultraviolet laser (System 1) or a mask and ultraviolet flood illumination, such as that provided by a repetitively pulsed, defocused excimer laser (System 2), for pattern definition, and (2) thermal deposition of metals from organometallic solutions or vapors utilizing a focused, CW laser beam as a local heat source to draw the metallization pattern. The purpose of this contract is to investigate the various existing laser-assisted film deposition techniques in order to develop a new, cost-effective technology ...

1984-01-16

171

Growth-related variations in the glycosaminoglycan synthesis of ultraviolet light-induced murine cutaneous fibrosarcoma cells  

Energy Technology Data Exchange (ETDEWEB)

Glycosaminoglycan synthesis was studied in cell populations of ultraviolet light-induced murine cutaneous fibrosarcoma cells under conditions of varying growth rates in vitro. After labeling with the precursors, /sup 3/H-glucosamine and /sup 35/SO/sub 4/, sulfated glycosaminoglycans recoverable by direct proteolysis of the culture monolayers increased approximately 5-fold on a per cell basis from sparsely populated, exponential cell cultures (greater than 85% of cells in S, G2, or M phases) to stationary cultures inhibited by high cell density (greater than 50% of cells in G1). Within this cell surface-associated material, the relative ratio of heparan sulfate to the chondroitin sulfates was approximately 60/40% under conditions of exponential growth; in the growth-arrested cultures, the reverse ratio was found. The substratum attached material, obtained from the flask surface after ethyl glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid ...

1985-08-01

172

Benzene molecule is destroyed by ultraviolet and soft X-rays in circumstellar environment  

International Nuclear Information System (INIS)

Benzene molecules , present in the proto-planetary nebula CRL 618, are ionized and dissociated by ultraviolet (UV) and X-ray photons originated from the hot central star and by its fast wind. Ionic species and free radicals produced by these processes can lead to the formation of new organic molecules. The aim of this work is to study the photoionization and photodissociation processes of the benzene molecule, using synchrotron radiation and time-of-flight mass spectrometry. Mass spectra were recorded at different energies corresponding to the vacuum UV (21.21 eV) and soft X-ray (282-310 eV) spectral regions. The production of ions from the benzene dissociative photoionization is here quantified, indicating that C_6H_6 is more efficiently fragmented by soft X-ray than UV radiation, where 50% of the ionized benzene molecules survive to UV dissociation while only about 4% resist to C-rays. Partial ion yields of H and small hydrocarbons, such as C_2H_2"+, C_3H_3"+, ...

173

X-ray and UV-light irradiation effects on oxide superconducting thin films  

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 by the irradiation. From these results we can find that irradiation with the X-ray ...

174

Using light to bioactivate surfaces: A new way of creating oriented, active immunobiosensors  

International Nuclear Information System (INIS)

Ultraviolet light can be used to immobilize biomolecules onto thiol reactive surfaces in order to, e.g., make biosensors. The mechanism involves light-induced formation of free, reactive thiol groups in disulphide containing molecules. This technology allows for the creation of arrays of biomolecules with a high degree of reproducibility, circumventing the need for often expensive nano/micro-dispensing technologies. The ultimate size of the immobilized spots is defined by the focal area of the UV beam. Light-induced immobilization has the added benefit that the immobilized molecules will be spatially oriented and covalently bound to the surface. In this paper, we demonstrate the utility of a sensor array created with the new sensor technology when integrated into a microfluidic system. Protein arrays made using light-induced immobilization showed successful antigen/antibody binding in a flow cell allowing the visualisation of real time binding and enzyme activity. ...

2007-12-15

175

Upper bound for a three-photon excitation cross section in atomic argon in the ultraviolet regime  

Energy Technology Data Exchange (ETDEWEB)

A scheme of evaluating a generalized three-photon excitation cross section sigma/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p/sup 6/ /sup 1/S/sub 0/ state to the 3p/sup 5/4s'(1/2)/sub 1//sup 0/ state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of ..delta..lambda/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is sigma/sub (3)/ = 1.414 x 10/sup -80/ cm/sup 6/ s/sup 2/. .AE

1989-04-15

176

The non-constant slope of the CIV Baldwin effect in NGC 4151  

CERN Document Server

The relationship between the emission line equivalent width and the continuum luminosity, so called the Baldwin effect, plays an important role in studying the broad line region physics of AGNs. Using the archived ultraviolet spectra obtained by IUE, HST and HUT in 1978-2002, we investigated the intrinsic CIV Baldwin effect of a best-studied Seyfert 1 galaxy NGC 4151. Both its continuum flux and CIV emission line flux varied about two orders of magnitude in more than two decades, making it one of the best targets for studying the slope variation of the Baldwin effect. We fitted the CIV line profile of the 490 archived UV spectra of NGC 4151 with a same model consisting of a few Gaussian components, and derived the slope in the log-log plot for the total flux of CIV emission line against the UV continuum flux in different observation epochs.We found that the slope is not constant for NGC 4151, varying from 0.58 in the highest flux epoch to 0.83 in the lowest flux ...

2006-01-01

177

The distribution of Lyman-limit absorption systems during and after reionization  

CERN Document Server

Lyman-limit absorption systems can play many important roles during and after cosmological reionization. Unfortunately, due to the prohibitively large dynamic range required, it is impossible to self-consistently include these systems in cosmological simulations. Using fast and versatile semi-numeric simulations, we systematically explore the spatial distribution of absorption systems during and following reionization. We self-calibrate the resulting number of absorbers to the mean free path (mfp) of the ionizing ultraviolet background (UVB), and present results at a given mfp and neutral hydrogen fraction. We use a simple optical depth criterion to identify the locations of absorbers. Our approach is fairly robust to uncertainties such as missing subgrid structure. Unlike at lower redshifts where the UVB is relatively uniform, at higher redshifts the fluctuations in the UVB and the HII morphology of reionization can drive the large-scale distribution of absorption ...

2010-01-01

178

The Cross-Calibration of Swift-BAT and Fermi-GBM via Correlative Spectral Analysis of GRBs  

CERN Document Server

We report on recent inter-calibration studies featuring Swift's Burst Alert Telescope (BAT) and Fermi's Gamma-ray Burst Monitor (GBM) based upon correlated observations of GRBs 080804 and 080810, via their resultant joint spectral analysis. Swift's intrinsic multi-wavelength instrumentation and dynamical response complement Fermi's superior energy range. The addition of BAT's spectral response will (i) facilitate in-orbit GBM detector response calibration, (ii) augment Fermi's low energy sensitivity, (iii) enable ground-based follow-up efforts of Fermi GRBs, and (iv) help identify a subset of GRBs discovered via off-line GBM data analysis, for an annual estimate of ~30 GRBs. The synergy of BAT and GBM augments previous successful joint spectral fit efforts by enabling the study of peak photon energies (Epeak), while leveraging the over eleven energy decades afforded by Fermi's Large Area Telescope (LAT), in conjunction with Swift's X-Ray (XRT) and ...

2009-01-01

179

Study on wavelength shortening and upgrading of the free electron laser (FEL)  

International Nuclear Information System (INIS)

This study is a task of ''Comprehensive study'' in ''nuclear energy basic technology research'', which is promoted under cooperation of four research institutes. The Electrotechnical Laboratory conducted, in 1991 in the first period of colaboration, on successful oscillation at visible region (598 nm) as the first case in Japan, construction of small type accumulation ring NIJI-IV for FEL, successful oscillation of visible range from 595 to 488 nm by installing optical krystron with maximum frequency in the world, and successful emittance lowering of accumulation beam by wide improvement of the ring. In the optical resonator, studies on minute loss measuring technique and on recovery from mirror deterioration were promoted. In the second period started from fiscal year of 1994, studies on FEL oscillation technique in short wavelength and upgrading of FEL corresponding to a frontier area were started, to succeed an oscillation experiment at 350 nm in ultraviolet ...

180

Studies on the Evolution of Silver Nanoparticles in Micelle by UV-Photoactivation  

Energy Technology Data Exchange (ETDEWEB)

Ultraviolet (UV) photoirradiation of Ag(I) compounds in the presence of an aqueous Triton X-100 solution has been exploited for the first time to prepare reproducible yellow silver hydrosol. The evolution of nanosized silver particles has been examined critically under the influence of different anions/ligands. Hence, time dependent evolution of silver hydrosol from different silver compounds in micelle via photochemical reduction is observed. Anions/ligands of precursor salts have been found to show profound influence (due to electron scavenging property, solubility, stability etc.) on the evolution route and efficiency of photochemical reduction of Ag(I) to Ag(O) in micelle and thereby classification of silver compounds becomes possible. Kinetic results reveal that the formation of silver particles proceeds via autocatalytic growth mechanism. The observed variation in rate constant values for the evolution of nanoparticles from different silver compounds have ...

2003-12-15

181

Structural transformations in Sc/Si multilayers irradiated by EUVlasers  

Energy Technology Data Exchange (ETDEWEB)

Multilayer mirrors for the extreme ultraviolet (EUV) are keyelements for numerous applications of coherent EUV sources such as newtabletop lasers and free-electron lasers. However the field ofapplications is limited by the radiation and thermal stability of themultilayers. Taking into account the growing power of EUV sources thestability of the optics becomes crucial. To overcome this problem it isnecessary to study the degradation of multilayers and try to increasetheir temporal and thermal stability. In this paper we report the resultsof detailed study of structural changes in Sc/Simultilayers when exposedto intense EUV laser pulses. Various types of surface damage such asmelting, boiling, shockwave creation and ablation were observed asirradiation fluencies increase. Cross-sectional TEM study revealed thatthe layer structure was completely destroyed in the upper part ofmultilayer, but still survived below. The layers adjacent tothe substrateremained intact even ...

2007-08-21

182

Semirelativistic technique for k#centre dot#p calculations: Optical properties of Pd and Pt  

International Nuclear Information System (INIS)

A semirelativistic two-component extended linear augmented plane-wave k#centre dot#p method is described. In order to ensure a high accuracy of the k#centre dot#p method, it is necessary to include into the radial-basis set, which is used for the augmentation of the plane waves, functions that are neither solutions of the Schrodinger equation nor their energy derivatives. The usual scalar relativistic procedure, which is nonlinear in energy, is not applicable to such basis sets. As an alternative, we suggest an approximation to the Foldy-Wouthuysen Hamiltonian that produces an explicitly Hermitean matrix in the augmented plane wave representation. The technique is applied to the calculation of the full dielectric matrix and optical properties of palladium and platinum metals over the photon energy region up to 100 eV. Special attention is paid to the far ultraviolet absorption by the excitations of semicore Pd 4p and Pt 5p and 4f states. A strong effect of local ...

2001-06-15

183

Seiberg duality and e+e- experiments  

Energy Technology Data Exchange (ETDEWEB)

Seiberg duality in supersymmetric gauge theories is the claim that two different theories describe the same physics in the infrared limit. However, one cannot easily work out physical quantities in strongly coupled theories and hence it has been difficult to compare the physics of the electric and magnetic theories. In order to gain more insight into the equivalence of two theories, we study the ''e{sup +}e{sup -}'' cross sections into ''hadrons'' for both theories in the superconformal window. We describe a technique which allows us to compute the cross sections exactly in the infrared limit. They are indeed equal in the low-energy limit and the equality is guaranteed because of the anomaly matching condition. The ultraviolet behavior of the total ''e{sup +}e{sup -}'' cross section is different for the two theories. We comment on proposed nonsupersymmetric ...

1998-10-02

184

Probing the Origins of the CIV and Fe Kalpha Baldwin Effect  

CERN Document Server

We use UV/optical and X-ray observations of 272 radio-quiet Type 1 AGNs and quasars to investigate the CIV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan Digital Sky Survey archives. The X-ray spectra are from the Chandra and XMM-Newton archives. We apply correlation and partial-correlation analyses to the equivalent widths, continuum monochromatic luminosities, and alpha_ox, which characterizes the relative X-ray to UV brightness. The equivalent width of the CIV 1549 emission line is correlated with both alpha_ox and luminosity. We find that by regressing l_UV with EW(CIV) and alpha_ox, we can obtain tighter correlations than by regressing l_UV with only EW(CIV). Both correlation and regression analyses imply that l_UV is not the only factor controlling the changes of EW(CIV); alpha_ox (or, equivalently, the soft X-ray emission) plays a fundamental role in the formation and ...

2009-01-01

185

Potassium deposition on a thiophene-terminated alkanethiol monolayer  

International Nuclear Information System (INIS)

Potassium deposition in ultrahigh vacuum on 12-(3-thienyl)dodecanethiol monolayers assembled on gold surfaces has been investigated using X-ray and ultraviolet photoelectron spectroscopies (XPS and UPS). Angle-resolved XPS indicates that initially deposited potassium penetrates the self-assembled monolayer (SAM) and diffuses to the SAM/Au interface. Even after large metal doses, the presence of thiophene ring valence electronic states in the UPS spectra confirms that most of the thiophene rings (at the SAM/vacuum interface) are not covered by potassium. The binding energy shifts of the thiophene ring valence states and the C1s and thiophene S2p peaks, referenced to the Fermi level, are due to the work function changes of the gold substrate. This indicates that these electronic states are pinned to the vacuum level, in contrast to the thiolate S2p orbital, which is pinned to the Fermi level. For large potassium doses, the appearance of new features in the UPS ...

2009-05-01

186

Photoconducting properties of ultraviolet detectors based on GaN and Al{sub 1{minus}x}Ga{sub x}N films grown by ECR-MBE  

Energy Technology Data Exchange (ETDEWEB)

GaN and Al{sub 1{minus}x}Ga{sub x}N films were grown by the method of ECR-MBE. Absorption constants as a function of wavelength were determined from transmission measurements. Photoconducting detectors were fabricated from these films and characterized in terms of their spectral response and photoconductive gain. Mobility-lifetime products were determined from the measurement of photoconductive gain. The resistivity and mobility-lifetime products of the films were varied from 10--10{sup 9} ohm-cm and 10{sup {minus}3}--10{sup {minus}8} cm{sup 2}/V respectively by changing the microwave power in the ECR discharge from 20--60 watts. The change in the mobility-lifetime product is attributed to change in the lifetimes of the photogenerated carriers. This assumption is supported by direct measurement of detector response times. Finally, the authors report for the first time, the detection of alpha particles using GaN detectors.

1997-12-31

187

Photoconducting properties of ultraviolet detectors based on GaN and Al_1_-_xGa_xN films grown by ECR-MBE  

International Nuclear Information System (INIS)

GaN and Al_1_-_xGa_xN films were grown by the method of ECR-MBE. Absorption constants as a function of wavelength were determined from transmission measurements. Photoconducting detectors were fabricated from these films and characterized in terms of their spectral response and photoconductive gain. Mobility-lifetime products were determined from the measurement of photoconductive gain. The resistivity and mobility-lifetime products of the films were varied from 10--10"9 ohm-cm and 10"-"3--10"-"8 cm"2/V respectively by changing the microwave power in the ECR discharge from 20--60 watts. The change in the mobility-lifetime product is attributed to change in the lifetimes of the photogenerated carriers. This assumption is supported by direct measurement of detector response times. Finally, the authors report for the first time, the detection of alpha particles using GaN detectors.

1996-12-02

188

Observation of multiorder coherent Raman sidebands in solid hydrogen film  

Energy Technology Data Exchange (ETDEWEB)

We investigated the Raman coherence characteristics of a solid hydrogen film deposited on a sapphire substrate held at 5.3 K. Using Raman coherence prepared with two single-frequency pulsed lasers, we generated the multiorder coherent Raman sidebands in solid hydrogen film. The highorder Raman sidebands were obtained under strong pumping intensities (>= 230 MW/cm{sup 2}). The generated anti-Stokes(AS)-Raman sidebands extend from the ultraviolet (292 nm for the AS5 band) to the visible (565 nm for the AS1 band) region. The multiorder Raman sideband generation is found to be due to the parametric coupling of pump and coupling lasers. The frequency conversion efficiency from pumping beams to the first AS-Raman sideband shows a maximum (14 %) at a pumping intensity of 360 MW/cm{sup 2}. From an experiment that makes the multimode probe beam beat with the prepared Raman coherence, we found that the prepared Raman coherence replicates the probe beam to its Raman ...

2004-07-15

189

Observation of multiorder coherent Raman sidebands in solid hydrogen film  

International Nuclear Information System (INIS)

We investigated the Raman coherence characteristics of a solid hydrogen film deposited on a sapphire substrate held at 5.3 K. Using Raman coherence prepared with two single-frequency pulsed lasers, we generated the multiorder coherent Raman sidebands in solid hydrogen film. The highorder Raman sidebands were obtained under strong pumping intensities (? 230 MW/cm2). The generated anti-Stokes(AS)-Raman sidebands extend from the ultraviolet (292 nm for the AS5 band) to the visible (565 nm for the AS1 band) region. The multiorder Raman sideband generation is found to be due to the parametric coupling of pump and coupling lasers. The frequency conversion efficiency from pumping beams to the first AS-Raman sideband shows a maximum (14 %) at a pumping intensity of 360 MW/cm2. From an experiment that makes the multimode probe beam beat with the prepared Raman coherence, we found that the prepared Raman coherence replicates the probe beam to its Raman sidebands.

2004-07-01

190

Modeling paraxial wave propagation in free-electron laser oscillators  

International Nuclear Information System (INIS)

Modeling free-electron laser (FEL) oscillators requires calculation of both the light-beam interaction within the undulator and the light propagation outside the undulator. We have developed a paraxial optical propagation code that can be combined with various existing models of gain media, for example, Genesis 1.3 for FELs, to model oscillators with full paraxial wave propagation within the resonator. A flexible scripting interface is used both to describe the optical resonator and to control the codes for propagation and amplification. To illustrate its capabilities, we numerically investigate two significantly different FEL oscillators: the free-electron laser for infrared experiments (FELIX) system and the vacuum-ultraviolet (VUV)-FEL oscillator of the proposed high-gain fourth generation light source. For the FELIX system, we find that diffraction losses are a considerable part of the single-pass cavity loss (at a wavelength of 40 #mu#m). We also demonstrate ...

2006-11-01

191

Mercury-free fluorescent lighting  

Energy Technology Data Exchange (ETDEWEB)

A brief comparative review of possible mercury free fluorescent lighting technologies is presented, including rare-gas positive column discharges, molecular discharges, and dielectric barrier discharges. Detailed experimental results on xenon positive column discharges will then be considered. In order to judge whether xenon-based discharges are a viable UV source it is necessary to measure the radiant emittance (power per unit area) for the vacuum ultraviolet (VUV) resonance xenon emission at 147 nm. Two techniques to determine the VUV radiant emittance have been developed and applied to xenon discharges. One method combines the measured resonance level density using absorption spectroscopy and a calculation of the trapped decay rate for the resonance radiation to arrive at the radiant emittance at 147 nm. A second method utilizes a direct measurement of the radiance (power per unit area per unit solid angle) at 147 nm using a calibrated VUV photodiode, and a ...

1996-05-01

192

Matrix-assisted laser desorption fourier transform mass spectrometry for biological compounds  

Science.gov (United States)

The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons). This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurement, and ion trapping experiments suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have recently demonstrated that matrix-assisted ...

1990-01-01

193

Luminescence properties of europium and terbium activated yttrium niobium/tantalate phosphors under VUV-UV excitation  

International Nuclear Information System (INIS)

Various compositions of Y(Ta,Nb)O4:Eu3+,Tb3+ with different Nb and activator concentrations have been investigated under UV and VUV excitation. Some compounds with very strong emission under VUV excitation were found. Such phosphors could be proposed as very good emissive materials for Displays and Lightings. The growing interest in luminescence spectroscopy of rare earth ions in the vacuum ultraviolet (VUV) and the visible (VIS) spectral range is due to industrial demands for new applications. YTaO4 and YNbO4 phosphors are a perspective class of efficient materials that are generally used in X-ray intensifying screens. These phosphors exhibit satisfying luminescence whenever excited by UV light, cathode radiation or X ray. However, to our knowledge, no work has been published on the VUV-excited luminescence for Eu3+ and Tb3+ double activated yttrium niobate and yttrium tantalate based phosphors. In this paper, the VUV-UV PL and PLE spectra of Eu3+ and/or Tb3+ ion ...

194

Light-Powered Molecular Engineering : a new technology for medical safety applications  

DEFF Research Database (Denmark)

We present a new photonic technology and demonstrate that it allows for precise immobilisation of biomolecules to sensor surfaces. The technology secures spatially controlled molecular immobilisation since immobilisation of each molecule to a support surface can be limited to the focal point of the ultraviolet (UV) beam, as small as a few micrometers. We can immobilise molecules according to any pattern, from classical microarrays to diffraction patterns creating unique watermarking safety patterns. Given that suitable protein markers exists for all relevant diseases it is entirely feasible to test for a range of disease indicators (antigens and other markers) in a single test. Few micrometer spotsize allows for a virtually unlimited number of protein spots in a multipotent microarray. This new technology produces radically new photonics based microarray sensing technology and watermarking and has clear potential for biomedical, bioelectronic, surface chemistry, ...

2007-01-01

195

Isolation and characterization of humic acids from peat soil  

International Nuclear Information System (INIS)

In this study, two different humic acids extracted from England and China peat soil, as well as three purified products extracted from commercially available humic acids [Fluka (Fluka, Neu-Ulm, Germany, Alfa (Alfa Aesar, Ward Hill, USA) and Aldrich (Aldrich-Chemical Co, Gillingham-Dorset)] were obtained respectively with the modified IHSS (International humic substances society) procedure. The chemical and structural information of these humic acids were characterized by some techniques, such as elemental analysis, ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and electropotential titration. UV-Vis spectra, infrared spectra, values for elemental composition and the contents of carboxyls, phenolic hydroxyls and total acidities of these humic acids were acquired. It is indicated that all these humic acids are different in the aspect of chemical structure, respectively, and these humic acids would be used for the ...

2009-05-01

196

Investigations of the green- and infrared-stimulated luminescence using the recuperation effect  

Energy Technology Data Exchange (ETDEWEB)

We used the recuperation effect (see also 'Recuperation of infrared stimulated luminescence of feldspars' in this issue) for investigating the connection between infrared- and greenlight-stimulated luminescence (IRSL and GLSL) of feldspars by performing a 'double-bleach recuperation' experiment. A diode system was used for infrared (IR) stimulation, and a filtered-light unit for greenlight (GL) stimulation. Powdered feldspar samples (2 mg each) of known chemical characterisation from a mineral collection were used. After beta-irradiation with 180 Gy and storage in the dark for several weeks feldspar aliquots were bleached down to a residual level of {approx}1% of the initial level, first with IR and subsequently with GL. For both stimulations, detection of the stimulated luminescence was carried out in the near ultraviolet region (around 260-360 nm, peaked at 340 nm). Other aliquots were bleached in reverse order (1st GL, 2nd ...

2000-12-15

197

Investigations of the green- and infrared-stimulated luminescence using the recuperation effect  

International Nuclear Information System (INIS)

We used the recuperation effect (see also 'Recuperation of infrared stimulated luminescence of feldspars' in this issue) for investigating the connection between infrared- and greenlight-stimulated luminescence (IRSL and GLSL) of feldspars by performing a 'double-bleach recuperation' experiment. A diode system was used for infrared (IR) stimulation, and a filtered-light unit for greenlight (GL) stimulation. Powdered feldspar samples (2 mg each) of known chemical characterisation from a mineral collection were used. After beta-irradiation with 180 Gy and storage in the dark for several weeks feldspar aliquots were bleached down to a residual level of #approx#1% of the initial level, first with IR and subsequently with GL. For both stimulations, detection of the stimulated luminescence was carried out in the near ultraviolet region (around 260-360 nm, peaked at 340 nm). Other aliquots were bleached in reverse order (1st GL, 2nd IR). These bleaching sequences were ...

2000-12-15

198

Influence of duration and rate of pulse rise of the applied voltage on ozone concentration in the barrier glow discharge  

International Nuclear Information System (INIS)

The barrier glow discharge between two planar electrodes, covered with dielectric, is studied under high-voltage pulsed power supply. Wide applications of such type of discharges, in particular, for ozone production, stimulated a number of investigations in this direction. In this work we investigated the dependence of ozone concentration on the duration and the rate of pulse rise of the applied voltage. The thyristor converter circuit with the shortening of input pulses on the base of the saturable throttle was used for the realization of this task. The output pulses with amplitude up to 15 kV, repetition frequency of 1 kHz, pulse duration of 0.3 #mu#s (or 7 #mu#s) and the rate of pulse rise of 0.1 #mu#s were generated with this scheme. Measurements of the ozone concentration produced in the air mixture have shown that its value increased by factor two with variation of the rate of pulse rise from 0.5 #mu#s to 0.1 #mu#s (for pulse duration of 7 #mu#s). The dependence of the ozone ...

2005-09-06

199

Industrial applications of the Jefferson Lab high-power free-electron laser  

International Nuclear Information System (INIS)

In partnership with the US Navy, high-technology corporations, and research universities, Jefferson Lab is building a superconducting radio-frequency (SRF) accelerator-driven free-electron laser (FEL) and is outfitting an FEL user facility. This first fourth-generation light source - a 1 kW, 3 #mu#m infrared (IR) laser - is the first step in a program to develop high-average-power SRF-based IR and ultraviolet (UV) FELs for multiple manufacturing applications as well as for defense-related applied research and basic scientific research. This initial FEL will be driven by a 42 MeV, 5 m A recirculating SRF linac similar to the much larger SRF linac in Jefferson Lab's 4 GeV, 200 #mu#A Continuous Electron Beam Accelerator Facility (CEBAF). The FEL is expected to demonstrate 75% energy recovery. Its linac will be cooled by the existing CEBAF cryogenic system. At Jefferson Lab, an infrastructure of facilities and people already supports the advance of SRF and closely ...

1998-09-02

200

Genotoxic effects of sunlight-activated waste waters  

Energy Technology Data Exchange (ETDEWEB)

Natural sunlight induces a genotoxic response in cultured CHO cells pre-treated with shale oil retort process water. Near ultraviolet light (NUV) component of the solar spectrum is the apparent radiation responsible for photoactivation. Cultured human skin fibroblasts are acutely sensitive to the genotoxic effects of photoactivated process water. The mutagenic potential of photoactivated process water in human cells is the same as that witnessed for an equivalent killing dose of the potent skin carcinogen FUV. DNA repair processes are involved in modulating genotoxic effects of this photo-induced process. The exact magnitude of the potential health-related and environmental risks resulting from photoactivation of retort process waters and other oil shale by-products is unassessed at this time. Our demonstration that a significant rate of mutation occurs in cultured human cells exposed to high dilutions of process waters and fluences of NUV comparable to that ...

1981-01-01

201

Generational Structure of Models with Dynamical Symmetry Breaking  

CERN Document Server

In models with dynamical electroweak symmetry breaking, this breaking is normally communicated to quarks and leptons by a set of vector bosons with masses generated via sequential breaking of a larger gauge symmetry. In reasonably ultraviolet-complete theories of this type, the number of stages of breaking of the larger gauge symmetry is usually equal to the observed number of quark and lepton generations, $N_{gen.}=3$. Here we investigate the general question of how the construction and properties of these models depend on $N_{gen.}$, regarded as a variable. We build and analyze models with illustrative values of $N_{gen.}$ different from 3 (namely, $N_{gen.}=1,2,4$) that exhibit the necessary sequential symmetry breaking down to a strongly coupled sector that dynamically breaks electroweak symmetry. Our results for variable $N_{gen.}$ show that one can robustly obtain, for this latter sector, a theory with a gauge coupling that is large but slowly running, ...

2010-01-01

202

Free-Electron Lasers: Present Status and Future Prospects  

Energy Technology Data Exchange (ETDEWEB)

Free-electron lasers as scientific instruments are reviewed. The present status and future prospects are delineated with attention drawn to the size, complexity, availability, and performance capability of this new tool. The Free-Electron Laser (FEL) was proposed by John Madey in 1970 (1), although earlier work, relevant to the concept, had been performed by Motz (2) and by Phillips (3). Experimental demonstration was achieved by Madey, et. al. in 1975 and 1976 (4). Since that time, FELs of diverse configurations have been operated at several laboratories around the world. At present, FEL development is focused in two directions: in constructing reliable FELs for scientific research and in extending FEL capability to vacuum ultra-violet (VUV) and even shorter wavelengths. In this article we shall only very briefly review the principles of an FEL, putting emphasis on those aspects that limit performance, after which we shall discuss the applications, present status ...

1990-05-01

203

Electronic structure and proton spin-lattice relaxation in PdH  

International Nuclear Information System (INIS)

We report a detailed augmented-plane-wave energy-band study and wave-function analysis of stoichiometric PdH which shows that, even though the Fermi surface of PdH is qualitatively similar to that of silver, the simple ''proton model'' is not valid. Instead, the screening of the proton in PdH is found to be larger than in an isolated H atom due, in part, to the formation of a H-Pd bonding band below the bottom of the d-band complex. This result, which is in qualitative agreement with Switendick's earlier calculation, is confirmed by ultraviolet photoemission experiments. A partial density-of-states (DOS) analysis in the energy range spanned by the six valence and conduction bands reveals the quantitative details of the bonding mechanism between the Pd and H constituents. At the Fermi energy, the high Pd d to H s DOS ratio approx. 10.3 is found to be far higher than expected in silver, despite the fact that the Fermi-surface geometry is similar. The field-induced ...

204

Effects of gamma irradiation on medicinal plants and spices (2): Piper cubeba, piper nigrum, piper retrofractum, amomum cardamomum, and myristica fragrans  

Energy Technology Data Exchange (ETDEWEB)

Effects of gamma irradiation on essential oils of five medicinal plants i.e. dried seeds of piper cubeba(cubeb), piper nigrum(black pepper), piper retrofractum, amomum cardamomum(cardamom) and myristica fragrans(mace), packed in low density polyethylene bag of 0.13 mm thickness have been investigated. After being irradiated at doses of 5 and 10 kGy, a part of the samples was analysed, and the rest were stored for six months at temperature of 30 +- 2 degC, and humidity ranging from 70 to 95%. The essential oil characteristics of control, irradiated and six month stored samples were analysed using infrared and ultraviolet spectrophotometers, HPLC, GLC and refractometer. Other parameters observed were moisture content and essential oil content of the samples. Results showed that irradiation up to a dose of 10 kGy do not give any significant effect on these parameters. Significant changes were only found in the essential oil content of piper cubeba, caused by storage ...

1983-12-01

205

Effect of V-shaped defects on structural and optical properties of AlGaN/InGaN multiple quantum wells  

International Nuclear Information System (INIS)

We have investigated the correlation between V-shaped defect formation and the optical properties of AlGaN/(In)GaN multiple quantum wells (MQWs) grown under different growth conditions and then demonstrated the characteristics of fabricated ultraviolet (UV) light emitting diodes (LEDs). From the temperature-dependent photoluminescence (PL) measurement, the internal quantum efficiency for 300 K was obtained as 43.6% for a sample with a low density of V-defects in a MQW and 13.7% for a sample with a high density of V-defects. The carrier lifetime based on the time resolved PL measurement at room temperature was 0.32 ns for a sample with a high density of V-defects and 1.26 ns for a sample with a low density of V-defects. And we also found that the density of V-defects affected the external quantum efficiency and wall plug efficiency of the fabricated UV LEDs. (fast track communication)

2008-07-07

206

Edge filter and fringe imaging for laser Doppler wind speed measurement  

Science.gov (United States)

Optical measurement of the Doppler shift of laser backscatter, using a near-IR, visible, or ultraviolet laser, is potentially more robust and field reliable than coherent, heterodyne measurement with an IR laser. The direct measurement of the displacement of Fabry-Perot interference fringes is possible, but entails expensive, technically challenging, imaging detectors. The 'edge technique' permits Doppler shift measurements with relatively simple detectors and detector electronics, and has been implemented with Fabry-Perot etalons and with atomic line filters. Simple analytical models of the fringe imaging and edge detection techniques are presented, permitting ready calculation of the potential performance of either, for various atmospheric conditions and for various lidar hardware configurations. The predictions of the analytical models are confirmed by computer models, which in turn allow more detailed considerations of complicating factors such as solar ...

1997-08-01

207

Curing of natural rubber and epoxy adhesive  

International Nuclear Information System (INIS)

Low molecular weight epoxy resin based on diglycidyl ether of bisphenol A was synthesized and mixed at constant percentages with natural rubber. The rubber epoxy system was cured with various types of curing agents such as ethylene diamine, maleic anhydride as well as the prepared resole phenol formaldehyde. A study of the photo-induced crosslinking of the prepared elastic adhesives and film samples was carried out by exposure to ultraviolet lamp (300 w) for 2 weeks at 20 deg. C. Samples containing ethylene diamine were cured at 25 + - 1 deg. C. for 24 h while samples containing maleic anhydride or resole phenol formaldehyde resins were thermally cured at 150-170 deg. C. for 10 min. Cured adhesive compositions were tested mechanically and physically and evaluated as wood adhesives. While hardness, chemical resistance as well as heat stability of the prepared cured film sample were investigated. The obtained data indicate that the highest epoxy resin content and the ...

2001-06-01

208

Comparative action spectrum for ultraviolet light killing of mouse melanocytes from different genetic coat color backgrounds  

International Nuclear Information System (INIS)

The photobiology of mouse melanocyte lines with different pigment genotypes was studied by measuring colony-forming ability after irradiation. The cell lines were wild-type black (melan-a) and the mutants brown (melan-b) and albino (melan-c). Four lamps emitting various UV wavelengths were used. These were germicidal (UVC, 200-280 nm), 82.3% output at 254 nm, TL01 (UVB, 280-320 nm), 64.2% at 310-311 nm, FS20, broadband with peak output at 312 nm and Alisun-S (UVA, 320-400 nm), broadband with peak output at 350-354 nm. Appropriate filtration reduced the contaminating UVC to nonlethal levels for the longer waverange lamps. It is clear from these studies that, in pigment cells, monochromatic results cannot predict polychromatic responses and that cell death from solar irradiations is a complex phenomenon that depends on more than DNA damage. (author).

1997-01-01

209

Adiabatic interpretation of particle creation in a de Sitter universe  

Energy Technology Data Exchange (ETDEWEB)

The choice of vacuum state for a quantum scalar field propagating in a de Sitter spacetime (massive and arbitrarily coupled to the gravitational field) is discussed. The problem of finite-time initial conditions for the mode functions is analyzed, as well as how these determine the vacuum state of the quantum system. The principle guiding the choice of vacuum state is the following: one wants the vacuum contribution to the energy-momentum tensor to contain all the ultraviolet divergent terms, so that the particle creation terms are finite, and covariantly conserved. There is a suitable set of modes (instantaneous adiabatic basis) in which this splitting of the expectation value of the energy-momentum tensor can be carried out. Numerical results are presented for different finite-time initial conditions (m = 0.6, {zeta} = 1/6). The nature of the particle creation effect is described and its relationship to the concept of a horizon crossing time is shown. These ...

1998-06-10

210

A fluorescent aminolipid from a green photosynthetic bacterium  

Energy Technology Data Exchange (ETDEWEB)

A preliminary chemical characterization is presented of phosphate-free aminolipids isolation from Chlorobium limicola f. thiosulfatophilum. The lipid contains no phosphorus, glycerol, sugar, ornithine, or lysine. Ultraviolet absorption and fluorescence spectra indicate that the amino moiety of the lipid is an aromatic heterocyclic compound. Infrared spectra indicate that the lipid is a secondary or tertiary amide, and gas chromatograhic analysis of the hydrolyzed lipid shows that for each 1100 g of lipid, 1 mol of myristic acid (C/sub 14:0/) is linked in an amide bond. Acid hydrolysis of the lipid yields two fluorescent substances, A (ninhydrine positive) and B (negative), in addition to myristic acid. Proton nuclear magnetic resonance (NMR) studies indicate that substance A contains a butyl groups attached to a conjugated ring carbon, two equivalent ethyl groups attached to one or two nitrogen atoms, and two downfield protons (8.4 ppm), perhaps attached to a ring ...

1983-04-12

211

Genetic engineering approaches to enrich rice with iron and vitamin A  

British Library Electronic Table of Contents (United Kingdom)

Major staple crops are often deficient in some of the nutrients required in human diet. Thus, malnutrition is a major problem, especially in developing countries, where a diversified diet is not affordable for the majority. Several strategies have been adopted to improve nutrition. However, micronutrient deficiency is still widely spread. Rice is one of the most important staple foods for a large part of the world's population. Therefore, even a small improvement in nutritional content of rice seeds can have a dramatic impact on human health. Different approaches are being exploited to produce rice enhanced in nutrients with iron and provitamin A.

2006-01-01

212

What Would Major General John A. Lejeune Think?  

Science.gov (United States)

... In the general portion of the article it states, that no more than three family members are authorized a one time travel and per diem for ...

2005-02-08

213

Viruses and thyroiditis: an update  

UK PubMed Central (United Kingdom)

Viral infections are frequently cited as a major environmental factor involved in subacute thyroiditis and autoimmune thyroid diseases This review examines the data related to the role of viruses in...Full Text Available

214

UK coal liquefaction  

Energy Technology Data Exchange (ETDEWEB)

The National Coal Board is investigating two routes for production of oils: liquid solvent extraction and supercritical gas extraction. Both these processes are considered ready for major development to plants of the 1 t/h scale.

1980-06-01

215

The sites and topology of mitochondrial superoxide production  

UK PubMed Central (United Kingdom)

Mitochondrial superoxide production is an important source of reactive oxygen species in cells, and may cause or contribute to ageing and the diseases of ageing. Seven major sites of superoxide...Full Text Available

2010-08-01

216

The incidence of complications associated with local anesthesia in dentistry.  

UK PubMed Central (United Kingdom)

Local anesthetics are frequently administered in dentistry and thus can be expected to be a major source of drug-related complications in the dental office. Additionally, the dentist will more often...Full Text Available

1997-01-01

217

The dengue viruses.  

UK PubMed Central (United Kingdom)

Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration,...Full Text Available

1990-10-01

218

The Mitoscriptome in Aging and Disease  

UK PubMed Central (United Kingdom)

Mitochondria are the major sites where energy is produced in the cell. Functions of organs such as the heart which has high energy demand are seriously affected by dysfunction of mitochondria....Full Text Available

2011-04-19

219

The Financial War on Terrorism: Grading US Strategy for ...  

Science.gov (United States)

... that operated in Pakistan, Dubai, and throughout the Middle East ... identifies 'funds' as one of eight major terrorist ... techniques, and procedures (TTP). ...

2006-04-15

220

The Assessment of Fracture Risk  

UK PubMed Central (United Kingdom)

Bone mineral density is considered to be the standard measure for the diagnosis of osteoporosis and the assessment of fracture risk. The majority of fragility fractures occur in patients with bone mineral...Full Text Available

2010-03-01

221

Streptococcus agalactiae mastitis: a review.  

UK PubMed Central (United Kingdom)

Streptococcus agalactiae continues to be a major cause of subclinical mastitis in dairy cattle and a source of economic loss for the industry. Veterinarians are often asked to provide information on...Full Text Available

1997-07-01

222

SECTION 3.0 TRIAL CONDUCT  

Science.gov (United States)

... adverse events and potential major events. 3.2.2.4 Clinical Events Committee (CEC) The independent CEC (cardiologists and neurologists ...

223

Reversing B cell aging  

UK PubMed Central (United Kingdom)

Age-related alterations in the cellular composition of the B lineage are a major cause of the poor antibody response to vaccination and to infectious agents among the elderly population. The mechanisms...Full Text Available

224

Repair of a Complex Congenital Cardiac Defect  

Medline Plus

... stenosis. It looks from the transesophageal and the 3-D echo that most of the problem is really ... posterior leaflet, which you can see on the 3-D echo image is a major source. The anterior ...

225

Phospholemman: A Novel Cardiac Stress Protein  

UK PubMed Central (United Kingdom)

Phospholemman (PLM), a member of the FXYD family of regulators of ion transport, is a major sarcolemmal substrate for protein kinases A and C in cardiac and skeletal muscle. In the heart, PLM...Full Text Available

2010-08-01

226

Oxidative Damage and the Prevention of Age-Related Cataracts  

UK PubMed Central (United Kingdom)

PurposeCataracts are often considered to be an unavoidable consequence of aging. Oxidative damage is a major cause or consequence of cortical and nuclear cataracts, the most common...Full Text Available

2010-09-01

227

NASA's Next Major Space Observatory - Flight Projects - NASA  

Science.gov (United States)

of Earth Science data and information management capabilities. Dale Schulz/400 . For your exceptional achievement in leading the joint LaRC/GSFC team in ...

228

NASA - Hurricane Season 2008: Hurricane Ike (Atlantic Ocean)  

Science.gov (United States)

The company reports that with the help of outside companies, they completed all major fixes including high-voltage transmission lines to neighborhood ...

229

Mitochondrial uncoupling and lifespan  

UK PubMed Central (United Kingdom)

The quest to understand why we age has given rise to numerous lines of investigation that have gradually converged to include metabolic control by mitochondrial activity as a major player. That...Full Text Available

2010-01-01

230

Mapping Deforestation and Land Use in Amazon Rainforest Using ...  

Science.gov (United States)

Jan 22, 2011 ... Abstract: Land use changes and deforestation in tropical rainforests are among the major factors affecting the overall function of the global ...

231

Management of primary sclerosing cholangitis  

UK PubMed Central (United Kingdom)

Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease with major morbidity and mortality. Therapeutic management is difficult, due to lack of conclusive data and individual disease...Full Text Available

2011-06-27

232

MICRONUTRIENTS/TRACE ELEMENTS - Global Change Master Directory (GCMD)  

Science.gov (United States)

Total concentrations of major and trace elements were determined in samples of the epilithic lichen Umbilicaria decussata from 24 ice-free areas in coastal ...

233

Late cenozoic evolution of Fortymile Wash: Major change in drainage pattern in the Yucca Mountain, Nevada region during late miocene volcanism  

International Nuclear Information System (INIS)

The site characterization of Yucca Mountain, NV as a potential high level nuclear waste repository includes study of the surficial deposits as a record of the paleoenvironmental history of the Yucca Mountain region. An important aspect of this history is an understanding of the evolution of paleogeography leading to establishment of the present drainage pattern. Establishment of drainage basin evolution is needed before geomorphic response to paleoclimate and tectonics can be assessed, because a major change in drainage basin geometry can predominantly affect the sedimentary record. Because alluvial aquifers are significant to regional hydrology, a major change in surface drainage resulting in buried alluvium could have hydrogeologic significance. In this paper, we report on geologic evidence for a major modification in surface drainage pattern in the Yucca Mountain region, resulting in the probable establishment of the ...

1994-05-22

234

Ischemic-Anoxia of the Central Nervous System: Iron ...  

Science.gov (United States)

... Joint Staff and other US Military (ie, Army, Navy, Air ... The major products of this work are significant advances in ... Keywords: Dogs; Laboratory animals ...

1986-10-15

235

Infantry Behind the Lines-Still a Viable Concept?  

Science.gov (United States)

Page 1. S~Infantry Behind the Lines- Still A Viable Concept? A Monograph by Major Mike McMahon Infantry 4T-' School ...

1993-12-17

236

In-situ micro-FTIR study of thermal changes of organics in Tagish ...  

Science.gov (United States)

FT-IR spectroscopic studies of major organic matter in carbonaceous chondrites using microscopic technique and comparison with terrestrial kerogen. ...

237

Health effects of indoor odorants.  

UK PubMed Central (United Kingdom)

People assess the quality of the air indoors primarily on the basis of its odors and on their perception of associated health risk. The major current contributors to indoor odorants are human occupant...Full Text Available

1991-11-01

238

General Disclaimer One or more of the Following Statements may ...  

Science.gov (United States)

major radius of the toroidal containment volume. The containment time was calculated using equation (4) as derived in references 16 and 17. The solid ...

239

Finding the Demons in Our Midst: Utilizing DOD ISR Assets to ...  

Science.gov (United States)

... six major international terrorist attacks are considered ... Tanzania and Kenya), the USS COLE bombing of ... the September 11th terrorist attack on the ...

2002-02-04

240

Expression and regulation of the NALP3 inflammasome complex in periodontal diseases  

UK PubMed Central (United Kingdom)

Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated...Full Text Available

2009-09-01

241

Evaluation of CFD to Determine Two-Dimensional Airfoil ...  

Science.gov (United States)

rotor flow field in which the main rotor operates. The majority of ..... early separation predicted by their CFD code was ...... Airfoil, AGARD Fluid Dynamics Panel ...

242

Endothelial von Willebrand factor regulates angiogenesis  

UK PubMed Central (United Kingdom)

The regulation of blood vessel formation is of fundamental importance to many physiological processes, and angiogenesis is a major area for novel therapeutic approaches to diseases from ischemia to...Full Text Available

2011-01-20

243

Developmentally programmed endoreduplication in animals  

UK PubMed Central (United Kingdom)

Development of a fertilized egg into an adult human requires trillions of cell divisions, the vast majority of which duplicate their genome once and only once. Nevertheless, trophoblast giant...Full Text Available

2009-05-15

244

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants  

UK PubMed Central (United Kingdom)

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using...Full Text Available

245

Current Status of Cognitive Behavioral Therapy for Adult Attention-Deficit Hyperactivity Disorder  

UK PubMed Central (United Kingdom)

SynopsisAttention-deficit / hyperactivity disorder (ADHD) is a valid and impairing psychological disorder that persists into adulthood in a majority of cases and is associated...Full Text Available

2010-09-01

246

Computed tomography of head in Clinic Pediatrics  

Energy Technology Data Exchange (ETDEWEB)

138 unselected head tomographies of children by computer are reported and analysed. The major aspect stressed by the authors is the excellent precision of this radiological technique.

1982-02-01

247

Cholera and other vibrio-associated diarrhoeas*  

UK PubMed Central (United Kingdom)

In recent years, there have been major advances in knowledge of Vibrio species and related organisms that are responsible for diarrhoeal diseases, particularly V. cholerae...Full Text Available

1980-01-01

248

Cardiac Angiosarcoma-Associated Membranoproliferative Glomerulonephropathy  

UK PubMed Central (United Kingdom)

Primary cardiac angiosarcoma is a rare cardiac tumor. The initial clinical course is often asymptomatic, and metastatic disease is present in a majority of affected patients at diagnosis. We present...Full Text Available

2011-01-01

249

Bladder outlet obstruction in male cystinuria mice  

UK PubMed Central (United Kingdom)

BackgroundCystinuria is the most common inherited cause of urinary tract stones in children. It can lead to obstructive uropathy, which is a major cause of renal...Full Text Available

2010-03-01

250

Antinociceptive actions of honokiol and magnolol on glutamatergic and inflammatory pain  

UK PubMed Central (United Kingdom)

The antinociceptive effects of honokiol and magnolol, two major bioactive constituents of the bark of Magnolia officinalis, were investigated on animal paw licking responses and thermal...Full Text Available

251

Alpha-toxin of Staphylococcus aureus.  

UK PubMed Central (United Kingdom)

Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble...Full Text Available

1991-12-01

252

Agricultural intensification increases deforestation fire activity ...  

Science.gov (United States)

Fire-driven deforestation is the major source of carbon emissions from Amazonia. Recent expansion of mechanized agriculture in forested regions of Amazonia ...

253

Accelerator technology program, January-June 1982. Status report  

International Nuclear Information System (INIS)

The major projects of the Los Alamos National Laboratory's Accelerator Technology Division are discussed, covering activities that occurred during the first six months of calendar 1982.

254

AIAA 98-3403 Evaluation of Propulsion Options for Interstellar ...  

Science.gov (United States)

require a major space-based infrastructure consisting of ..... gas (5 ppm of the He, 1.3 kg/year) or from weapons (15 kg/year). Because of the difficulty of ...

255

A Cyanobacterial Circadian Clockwork  

UK PubMed Central (United Kingdom)

Cyanobacteria have become a major model system for analyzing clock phenomena. The temporal program in this organism enhances fitness in rhythmic environments and is truly global—essentially...Full Text Available

2008-09-09

256

A Call for an Official Naval Doctrine  

Science.gov (United States)

... 1. Major Grover E. Myers, Aerospace Power: The Case for Indivisible ... 19. Admiral James D. Watkins, The Maritime Strategy (Annapolis: US Naval ...

1992-02-13

257

European Space Agency announces contest to "Name the Cluster Quartet"  

Science.gov (United States)

1. Contest rules The European Space Agency (ESA) is launching a public competition to find the most suitable names for its four Cluster II space weather satellites. The quartet, which are currently known as flight models 5, 6, 7 and 8, are scheduled for launch from Baikonur Space Centre in Kazakhstan in June and July 2000. Professor Roger Bonnet, ESA Director of Science Programme, announced the competition for the first time to the European Delegations on the occasion of the Science Programme Committee (SPC) meeting held in Paris on 21-22 February 2000. The competition is open to people of all the ESA member states (*). Each entry should include a set of FOUR names (places, people, or things from history, mythology, or fiction, but NOT living persons). Contestants should also describe in a few sentences why their chosen names would be appropriate for the four Cluster II satellites. The winners will be those which are considered most suitable and relevant for the Cluster II mission. ...

2000-02-01

258

The microbiology of forest soils: a literature review  

Energy Technology Data Exchange (ETDEWEB)

This report discusses the activities of two major groups of forest soil microorganisms, the bacteria and the fungi. Special attention is paid to their participation in the decay of major forest litter substrates, including leaves, branches and roots. The influence of bacteria and fungi in symbiotic associations with woody plant roots upon the cycles of carbon and nitrogen is described. The impacts of certain forest mamagement alternatives are assessed in terms of the creation of elimination of suitable environments for the activity of soil microorganisms. A bibliography is included. 507 refs., 1 tab.

1982-01-01

259

Mapping of TH1 helper T-cell epitopes on major secreted mycobacterial antigen 85A in mice infected with live Mycobacterium bovis BCG.  

UK PubMed Central (United Kingdom)

TH1 cytokine secretion was examined in response to synthetic peptides of the 85A component of the major secreted, fibronectin-binding antigen 85 complex from Mycobacterium tuberculosis in seven different...Full Text Available

1994-02-01

260

Liver volume in thalassaemia major: relationship with body weight, serum ferritin, and liver function  

Energy Technology Data Exchange (ETDEWEB)

It is not known whether body weight alone can adjust for the volume of liver in the calculation of the chelating dose in {beta}-thalassaemia major patients, who frequently have iron overload and hepatitis. The hypothesis is that liver volume in children and adolescents suffering from {beta}-thalassaemia major is affected by ferritin level and liver function. Thirty-five {beta}-thalassaemia major patients aged 7-18 years and 35 age- and sex-matched controls had liver volume measured by MRI. Serum alanine aminotransferase (ALT) and ferritin levels were obtained in the thalassaemia major patients. Body weight explained 65 and 86% of the change in liver volume in {beta}-thalassaemia major patients and age-matched control subjects, respectively. Liver volume/kilogram body weight was significantly higher (P<0.001) in thalassaemia major patients than in control ...

2005-02-01

261

Incidents of major damage to steam turbines  

International Nuclear Information System (INIS)

The author furnishes a review of incidents of major damage to high-output steam turbines. At the same time, he thereby underlines the call for an improvement in the exchange of experience on such damage and its causes at international level. Only the careful observance of past damage experience - including that of foreign manufacturers and operators - complete and modern monitoring equipment and the painstaking evaluation of all data furnished by such equipment can keep the risk of new technical development within economically tolerable limits. (orig.).

262

Financial statistics of major US publicly owned electric utilities 1994  

Energy Technology Data Exchange (ETDEWEB)

This publication presents 5 years (1990--94) of summary financial data and current year detailed financial data on the major publicly owned electric utilities. Generator and nongenerator summaries are presented. Composite tables present: Aggregates of income statement and balance sheet data, financial indicators, electric operation and maintenance expenses, electric utility plant, number of consumers, sales of electricity, and operating revenue, and electric energy account data.

1995-12-15

263

FLASH-the first soft x-ray free electron laser (FEL) user facility  

Energy Technology Data Exchange (ETDEWEB)

The free electron laser (FEL) FLASH at DESY in Hamburg is the first x-ray FEL ever built. Many new developments were necessary in order to exploit the unique properties of this novel light source for scientific experiments. The facility has constantly been improved and several major upgrades have been made or are currently underway. This paper reviews the main characteristics of the user facility as well as the major developments and upgrades.

2010-10-14

264

Determination by enzyme-linked immunosorbent assay of immunoglobulin G (IgG), IgM, and IgA to Brucella melitensis major outer membrane proteins and whole-cell heat-killed antigens in sera of patients with brucellosis.  

UK PubMed Central (United Kingdom)

An enzyme-linked immunosorbent assay was used to compare Brucella melitensis major outer membrane proteins (MOMP) and whole-cell heat-killed antigens (HK) in measuring antibrucella immunoglobulin G...Full Text Available

1989-08-01

265

Design, fabrication, qualification and reliability of the major components of ''MONJU'' from a safety point of view  

International Nuclear Information System (INIS)

This paper will review code and standard and the safety related features of major components of Monju: Components of the Reactor Coolant Boundary; Components of the Reactor Shurdown Systems; Components of the Decay Heat Removal Systems; Components of the Engineered Safety Features; Other Safety Related Components. Their relationship to the system or plant function is emphasized, in reviewing these components.

1982-07-01

266

Decreased serum protein binding of diazepam and its major metabolite in the neonate during the first postnatal week relate to increased free fatty acid levels.  

UK PubMed Central (United Kingdom)

The protein binding of diazepam (D) and its major active metabolite N-desmethyl diazepam (DD) was investigated in vitro in the serum of 14 mothers at birth, 21 foetuses at birth, in 100 neonates between...Full Text Available

1984-01-01

267

Both the Fas Ligand and Inducible Nitric Oxide Synthase Are Needed for Control of Parasite Replication within Lesions in Mice Infected with Leishmania major whereas the Contribution of Tumor Necrosis Factor Is Minimal  

UK PubMed Central (United Kingdom)

Following infection with the protozoan parasite Leishmania major, C57BL/6 mice develop a small lesion that heals spontaneously. Resistance to infection is associated with the development...Full Text Available

2003-09-01

268

Annual report 1993-1994  

Energy Technology Data Exchange (ETDEWEB)

The Atlantic Wind Test Site was established in 1980 as a laboratory to facilitate the evaluation and demonstration of wind energy systems and equipment. This annual report describes its organization and management, facilities, major projects, and the outlook for the future. Major projects include wind diesel; AWTS-IREQ collaboration; remote community data acquisition; lagerwey test program; Alaska Energy Authority Project; public education; Atlantic Orient Corporation 15/50 Project; and the soft VAWT project.

1994-12-31

269

Albian clastics in the western Arabian Gulf region: a sedimentological and petroleum-geological interpretation  

Energy Technology Data Exchange (ETDEWEB)

Clastic sediments of Albian age provide hydrocarbon source rocks, reservoirs and seals. Major reservoirs occur in sandstones to the north, and have a limited reservoir potential in offshore Qatar. Distal shales are a major seal in offshore Qatar, the United Arab Emirates and Oman. Local source-rock potential exists in the northern part of the Arabian Gulf and in the extreme SE of Saudi Arabia (in the Rub Al Khali Basin). (author)

1994-07-01

270

Recent strategy and progress in Korean nuclear PLIM program  

International Nuclear Information System (INIS)

The strategy for the Korean nuclear power plant lifetime management (PLIM) program, which has been developed over the last 3 years, is introduced, together with descriptions of recent events and related maintenance activities. This leading Korean PLIM project has been focused on such areas as a plant data survey, screening and prioritization of systems, structures and components (SSCs), aging evaluation of major components, economic analysis and regulatory issues. The current status is outlined in terms of major tasks including aging evaluation of 13 major components. The future long-term plan which eventually aims at maximizing the economic benefit for both the utility and its customers is presented. Also described is the technical development required for plant life extension. (orig.).

1996-05-08

271

Isoflavone content and apoptotic effect in HT-29 cancer cells of a soy germ extract  

British Library Electronic Table of Contents (United Kingdom)

Colon cancer is one of the leading causes of death and a major public health problem in western countries. We examined the isoflavone content of 70% ethanol extract of soy germ (SG) and its apoptotic effect in HT-29 colon cancer cells. Our results showed that the major isoflavones of the SG extract were daidzein and genistein, and it effectively induced apoptosis in HT-29 cancer cells. In addition, nuclear factor-kappa B (NF-kB) expression was reduced in cells treated with the SG extract, which reduced cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) expression. These combined effects ultimately resulted in apoptosis via caspase-3 activation. In addition, daidzein and genistein, the major isoflavones of SG extract, also exerted the apoptotic effect against HT-29 cancer cells. Thes...

2012-01-01

272

Exxon Valdez oil spill. State/federal natural resource damage assessment final report. Sockeye salmon overescapement. Fish/shellfish study number 27  

Energy Technology Data Exchange (ETDEWEB)

The authors examined the effects of large escapements of sockeye salmon in to the Kenai River and into Red and Akalura Lakes on Kodiak Island. Estimated smolt numbers outmigrating from the Kenai River decreased from 30 million in 1989 to under 500,000 in 1992. Decreased overwintering survival of age-0 juvenile sockeye salmon rearing in Skilak and Kenai lakes is the major contributor to this decline. Preliminary examination of limnological data from Skilak and Kenai Lakes provided no obvious explanation for this major decline in winter survival of juvenile sockeye. Due to differences in diel vertical migration of zooplankton among glacial lakes on the Kenai Peninsula with varying planktivores levels, the authors hypothesize that behavioral changes of zooplankton induced by predation may be a major contributor to the juvenile sockeye decline.

1993-07-01

273

Total skin electron beam therapy followed by adjuvant psoralen/ultraviolet-a light in the management of patients with T1 and T2 cutaneous T-cell lymphoma (mycosis fungoides)  

International Nuclear Information System (INIS)

Purpose: Patients with mycosis fungoides [cutaneous T-cell lymphoma (CTCL)] may benefit from adjuvant therapy after completing total skin electron beam therapy (TSEBT). We report the results for (T1(T2)) CTCL patients treated with adjuvant oral psoralen plus ultraviolet light (PUVA) with respect to overall survival (OS), disease-free survival (DFS), salvage of recurrence, and toxicity. Methods and Materials: Between 1974 and 1993, TSEBT was administered to a total of 213 patients with CTCL. Records were reviewed retrospectively, and a total of 114 patients were identified as having T1 or T2 disease. Radiotherapy was provided via a 6-MeV linac to a total of 36 Gy, 1 Gy/day, 4 days/week, for 9 weeks. Beginning in 1988, patients were offered adjuvant PUVA within 2 months of completing TSEBT. This was started at 0.5-2 J/m"2, 1-2 treatments/week, with a taper over 3-6 months. Therapy then continued once per month. There were 39 T1 and 75 T2 patients. Six T1 (15%) and ...

1997-07-15

274

The correlation between accelerated and field corrosion tests performed in carbon steel and weathering steel coupons, coated and non-coated; Correlacao entre ensaios acelerados e ensaios de campo em corpos-de-provas de aco carbono e aco patinavel, sem e com revestimento  

Energy Technology Data Exchange (ETDEWEB)

The performance of four different organic coating systems applied to carbon and weathering steel coupons has been assessed in this investigation. applied on the surface of carbon steel and weathering steel coupons. The coupons have been evaluated using five different tests, three field tests and two accelerated tests. The field tests were carried out at three atmospheric stations, located at COSIPA in Cubatao-SP, at Alto da Serra in Cubatao-SP and at Paula Souza in Sao Paulo city. The accelerated tests consisted of (a) exposure to alternate cycles of ultraviolet radiation/condensation combined with salt spray cycles (UVCON combined with Salt Spray) and of (b) exposure to alternate cycles of ultraviolet radiation/condensation combined with the Prohesion test. The performance of the coatings was assessed by visual observation and photographs, using a method based on ASTM D-610, ASTM D-714 and ASTM-1654 standards to rank them. The oxide phases ...

2002-07-01

275

flhDC, the Flagellar Master Operon of Xenorhabdus nematophilus: Requirement for Motility, Lipolysis, Extracellular Hemolysis, and Full Virulence in Insects  

UK PubMed Central (United Kingdom)

Xenorhabdus is a major insect pathogen symbiotically associated with nematodes of the family Steinernematidae. This motile bacterium displays swarming behavior on suitable media, but...Full Text Available

2000-01-01

276

Vascular Access Procedures (Central Catheters)  

Science.gov (United States)

... the major types of vascular access catheters: A peripherally inserted central catheter (PICC) is a long catheter that extends ... the procedure performed? A midline catheter and some peripherally inserted central catheter (PICC) lines may be inserted at your ...

277

Use of oral miltefosine for cutaneous leishmaniasis in Canadian soldiers returning from Afghanistan  

UK PubMed Central (United Kingdom)

Old world cutaneous leishmaniasis (CL) is caused by Leishmania major and Leishmania tropica, and is endemic to several Asian and Middle-Eastern countries where the...Full Text Available

2008-11-01

278

Urinary Outflow Obstruction Increases Apoptosis and Deregulates Bcl-2 and Bax Expression in the Fetal Ovine Bladder  

UK PubMed Central (United Kingdom)

During organogenesis, net growth of tissues is determined by a balance between proliferation, hypertrophy, and apoptotic death. Human fetal bladder outflow obstruction is a major cause of end-stage...Full Text Available

2003-04-01

279

UHRF1, a modular multi-domain protein, regulates replication-coupled crosstalk between DNA methylation and histone modifications  

UK PubMed Central (United Kingdom)

Cytosine methylation in DNA is a major epigenetic signal, and plays a central role in propagating chromatin status during cell division. However the mechanistic links between DNA methylation...Full Text Available

2009-01-01

280

Tumor Necrosis Factor-? and Muc2 Mucin Play Major Roles in Disease Onset and Progression in Dextran Sodium Sulphate-Induced Colitis  

UK PubMed Central (United Kingdom)

The sequential events and the inflammatory mediators that characterize disease onset and progression of ulcerative colitis (UC) are not well known. In this study, we evaluated the early pathologic events...Full Text Available

281

Treatment with Selective Serotonin Reuptake Inhibitors and Mirtapazine Results in Differential Brain Activation by Visual Erotic Stimuli in Patients with Major Depressive Disorder  

UK PubMed Central (United Kingdom)

ObjectiveThe objective of this study was to identify patterns of brain activation elicited by erotic visual stimuli in patients treated with either Selective Serotonin Reuptake Inhibitors...Full Text Available

2009-06-01

282

Transposable elements are enriched within or in close proximity to xenobiotic-metabolizing cytochrome P450 genes  

UK PubMed Central (United Kingdom)

BackgroundTransposons, i.e. transposable elements (TEs), are the major internal spontaneous mutation agents for the variability of eukaryotic genomes. To address the general issue...Full Text Available

283

Transmitted drug resistance in nonsubtype B HIV-1 infection  

UK PubMed Central (United Kingdom)

HIV-1 nonsubtype B variants account for the majority of HIV infections worldwide. Drug resistance in individuals who have never undergone antiretroviral therapy can lead to early failure and...Full Text Available

2009-09-01

284

Transcriptome Profiling of a Toxic Dinoflagellate Reveals a Gene-Rich Protist and a Potential Impact on Gene Expression Due to Bacterial Presence  

UK PubMed Central (United Kingdom)

BackgroundDinoflagellates are unicellular, often photosynthetic protists that play a major role in the dynamics of the Earth's oceans and climate. Sequencing of dinoflagellate nuclear...Full Text Available

285

Trans-Species Polymorphism and Selection in the MHC Class II DRA Genes of Domestic Sheep  

UK PubMed Central (United Kingdom)

Highly polymorphic genes with central roles in lymphocyte mediated immune surveillance are grouped together in the major histocompatibility complex (MHC) in higher vertebrates. Generally, across vertebrate...Full Text Available

286

Towards Commercial Production of Sponge Medicines  

UK PubMed Central (United Kingdom)

Sponges can provide potential drugs against many major world-wide occurring diseases. Despite the high potential of sponge derived drugs no sustainable production method has been developed. Thus far...Full Text Available

287

Torpor induction in mammals: Recent discoveries fueling new ideas  

UK PubMed Central (United Kingdom)

When faced with a harsh climate or inadequate food, some mammals enter a state of suspended animation known as torpor. A major goal of torpor research is to determine mechanisms that integrate...Full Text Available

2009-12-01

288

The rapid generation of chimerical genes expanding protein diversity in zebrafish  

UK PubMed Central (United Kingdom)

BackgroundVariation of gene number among species indicates that there is a general process of new gene origination. One of the major mechanism providing raw materials for the origin...Full Text Available

289

The oncogenic transforming potential of the passage of single ? particles through mammalian cell nuclei  

UK PubMed Central (United Kingdom)

Domestic, low-level exposure to radon gas is considered a major environmental lung-cancer hazard involving DNA damage to bronchial cells by α particles from radon progeny. At domestic exposure...Full Text Available

1999-01-05

290

The mitochondrial p53 pathway  

UK PubMed Central (United Kingdom)

p53 is one of the most mutated tumor suppressors in human cancers and as such has been intensively studied for a long time. p53 is a major orchestrator of the cellular response to a broad array...Full Text Available

2009-05-01

291

The erratic mitochondrial clock: variations of mutation rate, not population size, affect mtDNA diversity across birds and mammals  

UK PubMed Central (United Kingdom)

BackgroundDuring the last ten years, major advances have been made in characterizing and understanding the evolution of mitochondrial DNA, the most popular marker of molecular biodiversity....Full Text Available

292

The effects of an HIV project on HIV and non-HIV services at local government clinics in urban Kampala  

UK PubMed Central (United Kingdom)

BackgroundHIV/AIDS is a major public health concern in Uganda. There is widespread consensus that weak health systems hamper the effective provision of HIV/AIDS services. In recent...Full Text Available

293

The effect of lipopolysaccharide on bovine mammary macrophage function.  

UK PubMed Central (United Kingdom)

The effect of Escherichia coli lipopolysaccharide (LPS) on the expression of major histocompatibility complex (MHC) class II molecules by bovine mammary macrophages was examined. The ability of LPS-treated...Full Text Available

1991-07-01

294

The costs of hospitalization in patients with acute exacerbation of chronic obstructive pulmonary disease  

UK PubMed Central (United Kingdom)

Introduction:Chronic obstructive pulmonary disease (COPD) is a major public health problem. It imparts a substantial economic burden on individuals and society. Acute exacerbations...Full Text Available

295

The burden of pneumococcal disease in children less than 5 years of age in Abu Dhabi, United Arab Emirates  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE:Streptococcus pneumoniae is a major cause of mortality and morbidity in both developing and industrialized countries, especially...Full Text Available

2011-07-01

296

The Blind NasoTracheal Aspiration Method Is Not a Useful Tool for Pathogen Detection of Pneumonia in Children  

UK PubMed Central (United Kingdom)

BackgroundAcute lower respiratory infection (ALRI) is a major cause of hospitalization for children in China, while the etiological diagnosis of ALRI remains a challenge. This study...Full Text Available

297

Testing the Efficacy of a Multi-Component DNA-Prime/DNA-Boost Vaccine against Trypanosoma cruzi Infection in Dogs  

UK PubMed Central (United Kingdom)

BackgroundTrypanosoma cruzi, the etiologic agent of Chagas Disease, is a major vector borne health problem in Latin America and an emerging...Full Text Available

298

TRPV1 in Brain Is Involved in Acetaminophen-Induced Antinociception  

UK PubMed Central (United Kingdom)

BackgroundAcetaminophen, the major active metabolite of acetanilide in man, has become one of the most popular over-the-counter analgesic and antipyretic agents, consumed by millions...Full Text Available

299

Submicromolar concentrations of 4-hydroxynonenal induce glutamate cysteine ligase expression in HBE1 cells  

UK PubMed Central (United Kingdom)

4-Hydroxynonenal (HNE), a major electrophilic product of lipid peroxidation, is regarded as both a marker of oxidative stress and a mediator of oxidative damage. At subtoxic concentrations,...Full Text Available

2007-01-01

300

Strategies for initial management of hypertension  

UK PubMed Central (United Kingdom)

High blood pressure (BP) is a major public health problem in India and its prevalence is rapidly increasing among urban and rural populations. Reducing systolic and diastolic BP can decrease cardiovascular...Full Text Available

2010-11-01

301

Statistical methods for the blood beryllium lymphocyte proliferation test.  

UK PubMed Central (United Kingdom)

The blood beryllium lymphocyte proliferation test (BeLPT) is a modification of the standard lymphocyte proliferation test that is used to identify persons who may have chronic beryllium disease. A major...Full Text Available

1996-10-01

302

Spark decomposition of SF/sub 6/  

Energy Technology Data Exchange (ETDEWEB)

Gas-insulated systems employing SF/sub 6/ are utilized in a variety of applications in power delivery systems. Because electric arcs, sparks or corona can decompose SF/sub 6/ into by-products having chemical properties different from SF/sub 6/, environmental concerns arise regarding inadvertent human exposures to electrically-decomposed SF/sub 6/. Biological assays in our laboratory using mammalian cell culture systems have revealed that SF/sub 6/, spark-decomposed under specific experimental conditions, can produce cell death. Chemical analysis of spark-decomposed SF/sub 6/ has identified the major decomposition pathways and by-products. Biological testing of individual by-products or by-product mixtures has indicated that these major decomposition products may not account for the majority of the cell killing effects seen in our assays. Further experiments have suggested that S/sub 2/F/sub 10/ may be produced and ...

1989-07-01

303

Sociology and Space Development  

Science.gov (United States)

As the presence of humans in space expands in scope and duration, the quality of life in space as well as on Earth becomes pertinent. .... Military uses of space, such as the introduction of space-based laser or particle beam weapons, may have a major impact on the way people think and relate to .... AIAA Student Journal. ...

304

Shiga Toxin Subtypes Display Dramatic Differences in Potency ?  

UK PubMed Central (United Kingdom)

Purified Shiga toxin (Stx) alone is capable of producing systemic complications, including hemolytic-uremic syndrome (HUS), in animal models of disease. Stx includes two major antigenic forms (Stx1...Full Text Available

2011-03-01

305

Shelterin complex and associated factors at human telomeres  

UK PubMed Central (United Kingdom)

The processes regulating telomere function have major impacts on fundamental issues in human cancer biology. First, active telomere maintenance is almost always required for full oncogenic transformation...Full Text Available

2011-03-01

306

Sexually transmitted diseases: meeting the 1990 objectives--a challenge for the 1980s.  

UK PubMed Central (United Kingdom)

Sexually transmitted diseases (STDs) represent a major public health problem in the country, cause patients enormous suffering, and cost the nation billions of dollars annually. Demographic, sociological,...Full Text Available

1982-09-01

307

Separate Mechanisms for Audio-Tactile Pitch and Loudness Interactions  

UK PubMed Central (United Kingdom)

A major goal in perceptual neuroscience is to understand how signals from different sensory modalities are combined to produce stable and coherent representations. We previously investigated interactions...Full Text Available

308

Secular changes in height, weight and body mass index in Hong Kong Children  

UK PubMed Central (United Kingdom)

BackgroundLarge population growth surveys of children and adolescents aged 6 to 18 y were undertaken in Hong Kong in 1963 and 1993. The global epidemic of obesity is a major public...Full Text Available

309

Salmonellosis in Botswana  

UK PubMed Central (United Kingdom)

Clinical salmonellosis in cattle is infrequently recorded in Botswana, the majority of salmonella isolations being made from apparently healthy animals. A salmonella carrier rate of 6·7% was...Full Text Available

1971-09-01

310

Safety and Immunogenicity of Novel Recombinant BCG and Modified Vaccinia Virus Ankara Vaccines in Neonate Rhesus Macaques ?  

UK PubMed Central (United Kingdom)

Although major inroads into making antiretroviral therapy available in resource-poor countries have been made, there is an urgent need for an effective vaccine administered shortly after birth, which...Full Text Available

2010-08-01

311

Roles of lead-binding proteins in mediating lead bioavailability.  

UK PubMed Central (United Kingdom)

The intracellular bioavailability of lead (Pb) at low dosage levels in major target organs such as the kidney and brain appears to be largely determined by complexation with a group of low molecular...Full Text Available

1998-12-01

312

Role of bile salt in regulating Mcl-1 phosphorylation and chemoresistance in hepatocellular carcinoma cells  

UK PubMed Central (United Kingdom)

BackgroundGlycochenodeoxycholate (GCDA) is one of the major human bile salts. Bile salts stimulate cell survival and proliferation through the mitogen-activated protein kinase, but...Full Text Available

313

Rifampin pharmacokinetics in children, with and without human immunodeficiency virus infection, hospitalized for the management of severe forms of tuberculosis  

UK PubMed Central (United Kingdom)

BackgroundRifampin is a key drug in antituberculosis chemotherapy because it rapidly kills the majority of bacilli in tuberculosis lesions, prevents relapse and thus enables 6-month...Full Text Available

314

Reversal of Depressed Behaviors by p11 Gene Therapy in the Nucleus Accumbens  

UK PubMed Central (United Kingdom)

The etiology of major depression remains unknown, but dysfunction of serotonergic signaling has long been implicated in the pathophysiology of this disorder. p11 is an S100 family member recently...Full Text Available

2010-10-20

315

Research on ethics in two large Human Biomonitoring projects ECNIS and NewGeneris: a bottom up approach  

UK PubMed Central (United Kingdom)

Assessment of ethical aspects and authorization by ethics committees have become a major constraint for health research including human subjects. Ethical reference values often are extrapolated from...Full Text Available

316

Renal functions in pediatric patients with beta-thalassemia major: relation to chelation therapy: original prospective study  

UK PubMed Central (United Kingdom)

BackgroundIn β-thalassemia, profound anemia and severe hemosiderosis cause functional and physiological abnormalities in various organ systems. In recent years, there have...Full Text Available

317

Reduced-Median-Network Analysis of Complete Mitochondrial DNA Coding-Region Sequences for the Major African, Asian, and European Haplogroups  

UK PubMed Central (United Kingdom)

The evolution of the human mitochondrial genome is characterized by the emergence of ethnically distinct lineages or haplogroups. Nine European, seven Asian (including Native American), and three African...Full Text Available

2002-05-01

318

Ravenscraig coke ovens 1988 and onwards  

Energy Technology Data Exchange (ETDEWEB)

The coking plant is described with some details of coal supplies and coke quality. Engineering improvements to the by-product system and coke oven machines, major repair of two batteries, installation of a PLC-based monitoring and control system, and training of personnel are dealt with at greater length.

1989-01-01

319

Rare mutations predisposing to familial adenomatous polyposis in Greek FAP patients  

UK PubMed Central (United Kingdom)

BackgroundFamilial Adenomatous Polyposis (FAP) is caused by germline mutations in the APC (Adenomatous Polyposis Coli) gene. The vast majority of APC mutations...Full Text Available

320

Rapid in vivo transport and catabolism of human apolipoprotein A-IV-1 and slower catabolism of the apoA-IV-2 isoprotein.  

UK PubMed Central (United Kingdom)

Apolipoprotein (apo) A-IV is a polymorphic, intestinally derived apolipoprotein that is genetically linked to and similar in structure to apoA-I, the major apolipoprotein in high density lipoproteins...Full Text Available

1993-08-01

321

Rab protein evolution and the history of the eukaryotic endomembrane system  

UK PubMed Central (United Kingdom)

Spectacular increases in the quantity of sequence data genome have facilitated major advances in eukaryotic comparative genomics. By exploiting homology with classical model organisms, this makes possible...Full Text Available

2010-10-01

322

Queen's discovery lauded by top scientific journal  

CERN Multimedia

A scientific breakthrough at Queen's University's Sudbury Neutrino Observatory has received major international recognition. The journal Science ranked the discovery that cracked the "neutrino problem" second, in the journal's top 10 scientific achievements of 2002 (1/2 page).

2002-01-01

323

Quantification and deconvolution of asymmetric LC-MS peaks using the bi-Gaussian mixture model and statistical model selection  

UK PubMed Central (United Kingdom)

BackgroundLiquid chromatography-mass spectrometry (LC-MS) is one of the major techniques for the quantification of metabolites in complex biological samples. Peak modeling is one...Full Text Available

324

Purification and translation of murine mammary tumor virus mRNA's.  

UK PubMed Central (United Kingdom)

We have studied the functions of the intracellular RNAs of mouse mammary tumor virus (MMTV) by purification and translation in vitro. Two major size classes of MMTV RNA, 35S and 24S RNA, were isolated...Full Text Available

1981-07-01

325

Public interest in predictive genetic testing, including direct-to-consumer testing, for susceptibility to major depression: preliminary findings  

UK PubMed Central (United Kingdom)

The past decade has seen rapid advances in the identification of associations between candidate genes and a range of common multifactorial disorders. This paper evaluates public attitudes towards the...Full Text Available

2010-01-01

326

Prostaglandin-mediated closure of paracellular pathway and not restitution is the primary determinant of barrier recovery in acutely injured porcine ileum  

UK PubMed Central (United Kingdom)

SUMMARYSmall bowel epithelium is at the frontline of intestinal barrier function. Restitution is considered to be the major determinant of epithelial repair as function recovers...Full Text Available

2003-11-01

327

Prostaglandin-induced Abortion: Assessment of Operative Complications and Early Morbidity  

UK PubMed Central (United Kingdom)

A total of 626 patients undergoing a prostaglandin-induced abortion, the majority in the second trimester, have been analysed for complications occurring during inpatient treatment. Of the last 155...Full Text Available

1974-12-21

328

Problematic renal calculi presenting during pregnancy.  

UK PubMed Central (United Kingdom)

Urinary tract calculi presenting during pregnancy are rare, with less than 0.1% of pregnancies being associated with stones, the vast majority being asymptomatic and a chance finding. We outline six...Full Text Available

1996-03-01

329

Prevention of cardiovascular disease: Obesity, diabetes and the metabolic syndrome  

UK PubMed Central (United Kingdom)

The current obesity pandemic is expected to result in considerable downstream morbidity, mortality and incremental costs to health care systems around the world. The major metabolic complications of...Full Text Available

2010-08-01

330

Preterm low birthweight and the role of oral bacteria  

UK PubMed Central (United Kingdom)

Preterm and low birthweight (PTLBW) continues to be a major cause of mortality and morbidity across the world. In recent years, maternal periodontal disease has been implicated as a risk factor for...Full Text Available

331

Presence of preactivated T cells in hemodialyzed patients: their possible role in altered immunity.  

UK PubMed Central (United Kingdom)

Interleukin 2 (IL-2) and B-cell growth factors I and II (BCGF I and BCGF II) are lymphokines produced by T cells that play a major role in T- and B-cell cooperation. Peripheral blood lymphocytes from...Full Text Available

1986-10-01

332

Positional Stretching of the Coracohumeral Ligament on a Patient with Adhesive Capsulitis: A Case Report  

UK PubMed Central (United Kingdom)

Idiopathic frozen shoulder is a common medical diagnosis for patients seeking physical therapy. Radiographic and surgical evidence exists that describes the coracohumeral ligament (CHL) as a major contributor...Full Text Available

2009-01-01

333

Poland's anomaly. Natural history and long-term results of chest wall reconstruction in 33 patients.  

UK PubMed Central (United Kingdom)

Poland's anomaly is an uncommon congenital aberration of the chest wall characterized by absence of the pectoralis major muscle and other nearby musculoskeletal components. In this series, a wide spectrum...Full Text Available

1988-12-01

334

Patch Clamp Studies on Root Cell Vacuoles of a Salt-Tolerant and a Salt-Sensitive Plantago Species 1  

UK PubMed Central (United Kingdom)

Plantago media L. and Plantago maritima L. differ in their strategy toward salt stress, a major difference being the uptake and distribution of ions. Patch clamp techniques...Full Text Available

1990-01-01

335

Partial Purification and Characterization of Aminopeptidase II from Chara australis  

UK PubMed Central (United Kingdom)

Aminopeptidase II, one of the two major aminopeptidases in the giant alga Chara australis, was partially purified. Its molecular weight was estimated to be about 80,000 by gel permeation...Full Text Available

1989-02-01

336

PRELIMINARY STUDY ON MODIFICATION OF YOLK SAC OF ZEBRAFISH EMBRYOS (DANIO RERIO) USING MICROINJECTION  

UK PubMed Central (United Kingdom)

Low membrane permeability is one of the major obstacles to the successful cryopreservation of zebrafish embryos. The aim of the present study was to explore if this could be overcome by yolk...Full Text Available

2006-01-01

337

Origins, evolution, and phenotypic impact of new genes  

UK PubMed Central (United Kingdom)

Ever since the pre-molecular era, the birth of new genes with novel functions has been considered to be a major contributor to adaptive evolutionary innovation. Here, I review the origin and evolution...Full Text Available

2010-10-01

338

Organophosphate acetylcholine esterase inhibitor poisoning from a home-made shampoo  

UK PubMed Central (United Kingdom)

Organophosphate acetylcholine esterase inhibitor poisoning is a major health problem in children. We report an unusual cause of organophosphate acetylcholine esterase inhibitor poisoning. Two children...Full Text Available

2011-07-01

339

Observations on the use of solid-phase-coupled antibodies in the radioimmunoassay of human placental lactogen  

UK PubMed Central (United Kingdom)

A detailed comparative assessment was made of the use of solid-phase-coupled antibodies in radioimmunoassay, by using an assay for human placental lactogen as a model system. The major advantages of...Full Text Available

1974-03-01

340

Nucleoside Drugs Induce Cellular Differentiation by Caspase-Dependent Degradation of Stem Cell Factors  

UK PubMed Central (United Kingdom)

BackgroundStem cell characteristics are an important feature of human cancer cells and play a major role in the therapy resistance of tumours. Strategies to target cancer stem cells...Full Text Available

341

Nucleocapsid and Matrix Protein Contributions to Selective Human Immunodeficiency Virus Type 1 Genomic RNA Packaging  

UK PubMed Central (United Kingdom)

The nucleocapsid protein (NC) of retroviruses plays a major role in genomic RNA packaging, and some evidence has implicated the matrix protein (MA) of certain retroviruses in viral RNA binding. To further...Full Text Available

1998-03-01

342

Nuclear Receptor Rev-erb Alpha (Nr1d1) Functions in Concert with Nr2e3 to Regulate Transcriptional Networks in the Retina  

UK PubMed Central (United Kingdom)

The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated...Full Text Available

343

Noninvasive analysis of skin iron and zinc levels in beta-thalassemia major and intermedia  

Energy Technology Data Exchange (ETDEWEB)

Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for noninvasive determination of iron and zinc in two distinct skin areas, representing predominantly dermal and epidermal tissues, in 56 patients with beta-thalassemia major and intermedia. The mean iron levels in the skin of patients with beta-thalassemia major and intermedia were elevated by greater than 200% and greater than 50%, respectively, compared with control values. The zinc levels of both skin areas examined were within the normal range. The data indicate that the rate and number of blood transfusions, which correlated well with serum ferritin levels (r . 0.8), are not the only factors that determine the amount of iron deposition in the skin (r less than 0.6). Other sources of iron intake contribute to the total iron load in the tissues, particularly in patients who are not given multiple transfusions. The noninvasive quantitation of skin levels ...

1985-01-01

344

Non-myeloablative conditioning with allogeneic hematopoietic cell transplantation for the treatment of high-risk acute lymphoblastic leukemia  

UK PubMed Central (United Kingdom)

BackgroundAllogeneic hematopoietic cell transplantation is a potentially curative treatment for patients with acute lymphoblastic leukemia. However, the majority of older adults...Full Text Available

2011-08-01

345

Neurophysiological Endophenotypes Across Bipolar and Schizophrenia Psychosis  

UK PubMed Central (United Kingdom)

The search for liability genes of the world's 2 major psychotic disorders, schizophrenia and bipolar disorder I (BP-I), has been extremely difficult even though evidence suggests that both are highly...Full Text Available

2008-07-01

346

Neurons derived from reprogrammed fibroblasts functionally integrate into the fetal brain and improve symptoms of rats with Parkinson's disease  

UK PubMed Central (United Kingdom)

The long-term goal of nuclear transfer or alternative reprogramming approaches is to create patient-specific donor cells for transplantation therapy, avoiding immunorejection, a major complication in...Full Text Available

2008-04-15

347

Multi-formalism modelling and simulation: application to cardiac modelling  

UK PubMed Central (United Kingdom)

Cardiovascular modelling has been a major research subject for the last decades. Different cardiac models have been developed at a cellular level as well as at the whole organ level. Most of...Full Text Available

2004-01-01

348

Molecular characterization of a mannoprotein with homology to chitin deacetylases that stimulates T cell responses to Cryptococcus neoformans  

UK PubMed Central (United Kingdom)

The fungus Cryptococcus neoformans is a major cause of morbidity and mortality in patients with impaired CD4+ T cell function, particularly those with AIDS. To identify...Full Text Available

2001-08-28

349

Molecular Epidemiology of Escherichia coli Producing Extended-Spectrum ?-Lactamases Isolated in Rome, Italy?  

UK PubMed Central (United Kingdom)

Escherichia coli strains producing extended-spectrum β-lactamases (ESBLs) are a major problem in many different hospitals worldwide, causing outbreaks as well as sporadic infections....Full Text Available

2008-01-01

350

Modeling the emergence of universality in color naming patterns  

UK PubMed Central (United Kingdom)

The empirical evidence that human color categorization exhibits some universal patterns beyond superficial discrepancies across different cultures is a major breakthrough in cognitive science. As observed...Full Text Available

2010-02-09

351

Memorandum : No. 013-M : 01/20/95:More than 200 soldiers ...  

Science.gov (United States)

... has rotated active duty battalions from its light infantry divisions. ... the departure should contact Major Jim Hinnant, 82nd Airborne Division PAO, at ...

352

Malfunction of a Heimlich flutter valve causing tension pneumothorax: case report of a rare complication  

UK PubMed Central (United Kingdom)

BackgroundThoracic injuries play an important role in major trauma patients due to their high incidence and critical relevance. A serious consequence of thoracic trauma is pneumothorax,...Full Text Available

353

Malaria vectors and transmission dynamics in coastal south-western Cameroon  

UK PubMed Central (United Kingdom)

BackgroundMalaria is a major public health problem in Cameroon. Unlike in the southern forested areas where the epidemiology of malaria has been better studied prior to the implementation...Full Text Available

354

Making Clean Gasoline: The Effect on Jet Fuels.  

Science.gov (United States)

Persistently high concentrations of carbon monoxide and low-altitude ozone in the air of the Nation's major urban centers led Congress in the 1990 Clean Air Act Amendments to mandate changes to the composition of gasoline and diesel fuel. Those gasoline c...

1992-01-01

355

MULTITARGETED THERAPY OF CANCER BY GREEN TEA POLYPHENOLS  

UK PubMed Central (United Kingdom)

Tea ranks second only to water as a major component of fluid intake worldwide and has been considered a health-promoting beverage since ancient times. For the past two decades, we and others...Full Text Available

2008-10-08

356

Looking backward, 1984-1959: twenty-five years of library automation--a personal view.  

UK PubMed Central (United Kingdom)

A brief profile of Janet Doe is given. Twenty-five years of library automation are reviewed from the author's point of view. Major projects such as the SUNY Biomedical Communication Network and the...Full Text Available

1984-10-01

357

Long-lived states to sustain hyperpolarized magnetization  

UK PubMed Central (United Kingdom)

Major breakthroughs have recently been reported that can help overcome two inherent drawbacks of NMR: the lack of sensitivity and the limited memory of longitudinal magnetization. Dynamic nuclear polarization...Full Text Available

2009-11-03

358

Long-lasting inhibition of presynaptic metabolism and neurotransmitter release by protein S-nitrosylation  

UK PubMed Central (United Kingdom)

Nitric oxide (NO) and related reactive nitrogen species (RNS) play a major role in the pathophysiology of stroke and other neurodegenerative diseases. One of the poorly understood consequences...Full Text Available

2010-09-01

359

Localization of a critical restriction site on the I-A beta chain that determines susceptibility to collagen-induced arthritis in mice.  

UK PubMed Central (United Kingdom)

Type II collagen-induced arthritis (CIA) in mice is an autoimmune experimental model for rheumatoid arthritis. Susceptibility to CIA is associated with certain major histocompatibility complex class...Full Text Available

1989-12-01

360

Levels and Patterns of Nucleotide Variation in Domestication QTL Regions on Rice Chromosome 3 Suggest Lineage-Specific Selection  

UK PubMed Central (United Kingdom)

Oryza sativa or Asian cultivated rice is one of the major cereal grass species domesticated for human food use during the Neolithic. Domestication of this species from the wild grass...Full Text Available

361

Late onset muscle plasticity in the whisker pad of enucleated rats  

UK PubMed Central (United Kingdom)

Blindness leads to a major reorganization of neural pathways associated with touch. Because incoming somatosensory information influences motor output, it is plausible that motor plasticity occurs in...Full Text Available

2008-10-14

362

Landscape determinants and remote sensing of anopheline mosquito larval habitats in the western Kenya highlands  

UK PubMed Central (United Kingdom)

BackgroundIn the past two decades the east African highlands have experienced several major malaria epidemics. Currently there is a renewed interest in exploring the possibility...Full Text Available

363

Lack of LDL Receptor Enhances Amyloid Deposition and Decreases Glial Response in an Alzheimer's Disease Mouse Model  

UK PubMed Central (United Kingdom)

BackgroundApolipoprotein E (ApoE), a cholesterol carrier associated with atherosclerosis, is a major risk factor for Alzheimer's disease (AD). The low-density lipoprotein receptor...Full Text Available

364

Invasion and control of water hyacinth (Eichhornia crassipes) in China*  

UK PubMed Central (United Kingdom)

By the time of primary 21st century, water hyacinth had become a serious environmental problem in China. Water hyacinth contributes to the major part of ecological hazards from the invasion of foreign...Full Text Available

2006-08-01

365

Integrase-directed recovery of functional genes from genomic libraries  

UK PubMed Central (United Kingdom)

Large population sizes, rapid growth and 3.8 billion years of evolution firmly establish microorganisms as a major source of the planet's biological and genetic diversity. However, up to 99% of the...Full Text Available

2009-09-01

366

Institute of Plasma Physics, Academy of Sciences of the Czech Republic  

International Nuclear Information System (INIS)

The major activities of the various Institute's departments are highlighted. The following departments are included: (i) Tokamak; (ii) Pulse plasma systems; (iii) Thermal plasma; (iv) Materials engineering; (v) Laser plasma; and (vi) Optical diagnosis. (P.A.)

367

Induction and transmission of Bacillus thuringiensis tolerance in the flour moth Ephestia kuehniella  

UK PubMed Central (United Kingdom)

The use of Bacillus thuringiensis (Bt) endotoxins to control insect vectors of human diseases and agricultural pests is threatened by the possible evolution of resistance in major pest...Full Text Available

2004-03-02

368

IgE antibodies to D. pteronyssinus in atopic patients.  

UK PubMed Central (United Kingdom)

An aqueous house dust mite extract was separated by SDS-PAGE and transferred to nitrocellulose membranes by Western Blotting. Two major allergens, Der pI and Der pII associated with the mite faeces...Full Text Available

1988-06-01

369

Identification of plasmid and Bacillus subtilis chromosomal recombination sites used for pE194 integration.  

UK PubMed Central (United Kingdom)

The plasmid pE194 (3.7 kilobases) is capable of integrating into the genome of the bacterial host Bacillus subtilis in the absence of the major homology-dependent RecE recombination system. Multiple...Full Text Available

1989-05-01

370

Identification of cell cycle-related regulatory motifs using a kernel canonical correlation analysis  

UK PubMed Central (United Kingdom)

BackgroundGene regulation is a key mechanism in higher eukaryotic cellular processes. One of the major challenges in gene regulation studies is to identify regulators affecting the...Full Text Available

371

Identification of Human Prostate Cancer Stem Cells by ...  

Science.gov (United States)

... The basal markers CK5, alpha 6 integrin (CD49f), CD44, and p63 were strongly expressed by the majority of sphere-forming cells. ... p63 p63 PSCA ...

2008-04-01

372

Identification and Characterization of Novel MicroRNAs from Schistosoma japonicum  

UK PubMed Central (United Kingdom)

BackgroundSchistosomiasis japonica remains a major public health problem in China. Its pathogen, Schistosoma japonicum has a complex life cycle and a unique repertoire...Full Text Available

373

Host plant shifts affect a major defense enzyme in Chrysomela lapponica  

UK PubMed Central (United Kingdom)

Chrysomelid leaf beetles use chemical defenses to overcome predatory attack and microbial infestation. Larvae of Chrysomela lapponica that feed on willow sequester plant-derived salicin...Full Text Available

2011-03-22

374

High-speed railway systems for Europe; Eisenbahn-Hochgeschwindigkeitssysteme fuer Europa  

Energy Technology Data Exchange (ETDEWEB)

How can the inhabitants of the European Union be brought closer together? One way of doing it is to expand and improve the trans-European railway network and to have interoperable highspeed trains connecting Europe's major centres. (orig.)

2008-03-15

375

High-pressure/low-temperature neutron scattering of gas inclusion compounds: Progress and prospects  

UK PubMed Central (United Kingdom)

Alternative energy resources such as hydrogen and methane gases are becoming increasingly important for the future economy. A major challenge for using hydrogen is to develop suitable materials to store...Full Text Available

2007-04-03

376

High prevalence of syphilis among demobilized child soldiers in Eastern Congo: a cross-sectional study  

UK PubMed Central (United Kingdom)

BackgroundSyphilis, a known major public health issue for soldiers during periods of conflict, is exacerbated in the Democratic Republic of Congo due to widespread sexual violence....Full Text Available

377

Helicobacter pylori infection, oncogenic pathways and epigenetic mechanisms in gastric carcinogenesis  

UK PubMed Central (United Kingdom)

Chronic colonization of the human stomach by Helicobacter pylori, a Gram-negative bacterium, is the major cause of chronic gastritis, peptic ulcers and gastric cancer. Recent...Full Text Available

2010-05-01

378

Health education for microcredit clients in Peru: a randomized controlled trial  

UK PubMed Central (United Kingdom)

BackgroundPoverty, lack of female empowerment, and lack of education are major risk factors for childhood illness worldwide. Microcredit programs, by offering small loans to poor...Full Text Available

379

Glycyrrhizin as antiviral agent against Hepatitis C Virus  

UK PubMed Central (United Kingdom)

BackgroundHepatitis C virus is a major cause of chronic liver diseases which can lead to permanent liver damage, hepatocellular carcinoma and death. The presently available treatment...Full Text Available

380

Glutamate Transporter EAAT2 Expression is Up-Regulated in Reactive Astrocytes in Human Periventricular Leukomalacia  

UK PubMed Central (United Kingdom)

The major neuropathological correlate of cerebral palsy in premature infants is periventricular leukomalacia (PVL), a disorder of the immature cerebral white matter. Cerebral ischemia leading...Full Text Available

2008-05-10

381

Germ cell sex determination in mammals  

UK PubMed Central (United Kingdom)

One of the major decisions that germ cells make during their development is whether to differentiate into oocytes or sperm. In mice, the germ cells’ decision to develop as male or female depends...Full Text Available

2009-04-01

382

Genomic Evidence for the Evolution of Streptococcus equi: Host Restriction, Increased Virulence, and Genetic Exchange with Human Pathogens  

UK PubMed Central (United Kingdom)

The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered....Full Text Available

2009-03-01

383

Genome-Wide Analysis Reveals a Major Role in Cell Fate Maintenance and an Unexpected Role in Endoreduplication for the Drosophila FoxA Gene Fork Head  

UK PubMed Central (United Kingdom)

Transcription factors drive organogenesis, from the initiation of cell fate decisions to the maintenance and implementation of these decisions. The Drosophila embryonic salivary gland...Full Text Available

384

Gene expression patterns in four brain areas associate with quantitative measure of estrous behavior in dairy cows  

UK PubMed Central (United Kingdom)

BackgroundThe decline noticed in several fertility traits of dairy cattle over the past few decades is of major concern. Understanding of the genomic factors underlying fertility,...Full Text Available

385

Fungal recognition is mediated by the association of dectin-1 and galectin-3 in macrophages  

UK PubMed Central (United Kingdom)

Dectin-1, the major β-glucan receptor in leukocytes, triggers an effective immune response upon fungal recognition. Here we use sortase-mediated transpeptidation, a technique that allows placement...Full Text Available

2011-08-23

386

Forschungszentrum Juelich, Institut fuer Kernphysik/COSY. Annual report 2004  

Energy Technology Data Exchange (ETDEWEB)

The following topics are dealt with: Detectors at COSY, major physics results at COSY, physics at external facilities, theoretical investigations, COSY operation and developments, preparations for FAIR, technical developments. (HSI)

2005-03-01

387

Food Advertising and Marketing Directed at Children and Adolescents in the US  

UK PubMed Central (United Kingdom)

In recent years, the food and beverage industry in the US has viewed children and adolescents as a major market force. As a result, children and adolescents are now the target of intense and specialized...Full Text Available

388

FY1995 transduction method and CAD database systems for integrated design; 1995 nendo transduction ho to CAD database togo sekkei shien system  

Energy Technology Data Exchange (ETDEWEB)

Transduction method developed by the research coordinator and Prof. Muroga is one of the most popular methods to design large-scale integrated circuits, and thus used by major design tool companies in USA and Japan. The major objectives of the research is to improve capability and utilize its reusable property by combining with CAD databases. Major results of the project is as follows, (1) Improvement of Transduction method : Efficiency, capability and the maximum circuit size are improved. Error compensation method is also improved. (2) Applications to new logic elements : Transduction method is modified to cope with wired logic and FPGAs. (3) CAD databases : One of the major advantages of Transduction methods is 'reusability' of already designed circuits. It is suitable to combine with CAD databases. We design CAD databases suitable for cooperative design using Transduction method. ...

1997-03-01

389

FELIX Experiments: Measurements of Electromagnetic Effects.  

Science.gov (United States)

Three major series of experiments have been conducted with the FELIX facility at ANL. Experiments on the coupling between eddy currents and angular displacements of loops and plates in crossed constant and changing magnetic fields demonstrated that the co...

1985-01-01

390

Extracellular Administration of BCL2 Protein Reduces Apoptosis and Improves Survival in a Murine Model of Sepsis  

UK PubMed Central (United Kingdom)

BackgroundSevere sepsis and septic shock are major causes of morbidity and mortality worldwide. In experimental sepsis there is prominent apoptosis of various cell types, and genetic...Full Text Available

391

Expression of CD1d in human scalp skin and hair follicles: hair cycle related alterations  

UK PubMed Central (United Kingdom)

Background: CD1d belongs to a family of antigen presenting molecules that are structurally and distantly related to the classic major histocompatibility complex class I (MHC I)...Full Text Available

2005-12-01

392

Exploring the impact of a decision support intervention on vascular access decisions in chronic hemodialysis patients: study protocol  

UK PubMed Central (United Kingdom)

BackgroundIn patients with Stage 5 Chronic Kidney Disease who require renal replacement therapy a major decision concerns modality choice. However, many patients defer the decision...Full Text Available

393

Evidence of a general 2/3-power law of scaling leaf nitrogen to phosphorus among major plant groups and biomes  

UK PubMed Central (United Kingdom)

Scaling relations among plant traits are both cause and consequence of processes at organ-to-ecosystem scales. The relationship between leaf nitrogen and phosphorus is of particular interest, as both...Full Text Available

2010-03-22

394

Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull  

UK PubMed Central (United Kingdom)

The fossil record is a unique source of evidence for important evolutionary phenomena such as transitions between major clades. Frustratingly, relevant fossils are still comparatively rare, most transitions...Full Text Available

2010-02-07

395

Evidence That Two Major Replicons Comprise the Genome of Staphylococcus Aureus.  

Science.gov (United States)

In Staphylococcus aureus, a pronounced shift in position of the acriflavin resistance locus was observed when gene order was determined by marker frequency analysis of cells of various ages. In young cells (2-hour culture), acriflavin resistance was mappe...

1967-01-01

396

Evaluation of the PHQ-2 as a Brief Screen for Detecting Major Depression among Adolescents  

UK PubMed Central (United Kingdom)

ObjectiveTo examine the validity of the Patient Health Questionnaire - 2 (PHQ-2), a 2-item depression screening scale among adolescents.Full Text Available

2010-05-01

397

Epidemiology of underweight and overweight-obesity among term pregnant Sudanese women  

UK PubMed Central (United Kingdom)

BackgroundThe increasing prevalence of obesity in young women is a major public health concern. Few data are available concerning the epidemiology of malnutrition especially obesity...Full Text Available

398

Enhancing Patient Safety by Reducing Healthcare-Associated Infections: The Role of Discovery and Dissemination  

UK PubMed Central (United Kingdom)

Healthcare-associated infections (HAIs) take a major human toll on society and reduce public confidence in the healthcare system. The current convergence of scientific, public, and legislative...Full Text Available

2010-02-01

399

Effect of Dexrazoxane and Amifostine on the Vertebral Bone Quality of Doxorubicin Treated Male Rats  

UK PubMed Central (United Kingdom)

Doxorubicin (DOX) is widely used in combination cocktails for treatment of childhood hematological cancers and solid tumors. A major factor limiting DOX usage is DOX-induced cardiotoxicity. However,...Full Text Available

400

Direct liquefaction contractors' review meeting: Proceedings  

Energy Technology Data Exchange (ETDEWEB)

Research programs on coal liquefaction are presented. Major topics include: coprocessing, two-stage liquefaction, low severity liquefaction, coal/catalyst and liquefaction chemistry. Individual projects are processed separately for the data bases. (CBS)

1988-01-01

401

Differential chemosensitization of P-glycoprotein overexpressing K562/Adr cells by withaferin A and Siamois polyphenols  

UK PubMed Central (United Kingdom)

BackgroundMultidrug resistance (MDR) is a major obstacle in cancer treatment and is often the result of overexpression of the drug efflux protein, P-glycoprotein (P-gp), as a consequence...Full Text Available

402

Detection of trypanosomes in small ruminants and pigs in western Kenya: important reservoirs in the epidemiology of sleeping sickness?  

UK PubMed Central (United Kingdom)

BackgroundTrypanosomosis is a major impediment to livestock farming in sub-Saharan Africa and limits the full potential of agricultural development in the 36 countries where it is...Full Text Available

403

Detection of Streptococcus mutans Genomic DNA in Human DNA Samples Extracted from Saliva and Blood  

UK PubMed Central (United Kingdom)

Caries is a multifactorial disease, and studies aiming to unravel the factors modulating its etiology must consider all known predisposing factors. One major factor is bacterial colonization,...Full Text Available

2011-01-01

404

Defective major histocompatibility complex class I expression on lymphoid cells in autoimmunity.  

UK PubMed Central (United Kingdom)

Lymphocytes from patients with insulin-dependent diabetes mellitus (IDDM), a chronic autoimmune disease, have recently been shown to have decreased surface expression of MHC class I antigens. Since...Full Text Available

1993-05-01

405

DNA sequencing using biotinylated dideoxynucleotides and mass spectrometry  

UK PubMed Central (United Kingdom)

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) has been explored widely for DNA sequencing. The major requirement for this method is that the DNA sequencing fragments...Full Text Available

2001-11-01

406

DNA methylation and gene expression differences in children conceived in vitro or in vivo  

UK PubMed Central (United Kingdom)

Epidemiological data indicate that children conceived in vitro have a greater relative risk of low birth-weight, major and minor birth defects, and rare disorders involving imprinted...Full Text Available

2009-10-15

407

D2-40, Podoplanin, and CD31 as a Prognostic Predictor in Invasive Ductal Carcinomas of the Breast  

UK PubMed Central (United Kingdom)

PurposeDistant metastasis and recurrence are major prognostic factors associated with breast cancer. Both lymphovascular invasion (LVI) and blood vessel invasion (BVI) are important...Full Text Available

2011-06-01

408

Cystic neoplasms of the pancreas: A diagnostic challenge  

UK PubMed Central (United Kingdom)

Cystic neoplasms of the pancreas are increasingly recognized due to the expanding use and improved sensitivity of cross-sectional abdominal imaging. Major advances in the last decade have led to an...Full Text Available

2009-01-07

409

Current and potential future drug treatments for osteoporosis.  

UK PubMed Central (United Kingdom)

There has been a major interest in the drug treatment of osteoporosis and an increase in the number of drugs available in most countries. The ideal drug (one which increases or restores bone density...Full Text Available

1996-10-01

410

Coolant rate distribution in horizontal steam generator under natural circulation  

Energy Technology Data Exchange (ETDEWEB)

In the presentation the major factors determining the conditions of NCC (Natural Coolant Circulation) in the primary circuit and in particular conditions of coolant rate distribution on the horizontal tubes of PGV-1000 in NPP with VVER-1000 under NCC are considered. 5 refs.

1997-12-31

411

Convection-enhanced Delivery of Free Gadolinium with the Recombinant Immunotoxin MR1-1  

UK PubMed Central (United Kingdom)

PurposeA major obstacle in glioblastoma (GBM) therapy is the restrictive nature of the blood-brain barrier (BBB). Convection-enhanced delivery (CED) is a novel method...Full Text Available

2010-05-01

412

Contrasting Population Structures of the Genes Encoding Ten Leading Vaccine-Candidate Antigens of the Human Malaria Parasite, Plasmodium falciparum  

UK PubMed Central (United Kingdom)

The extensive diversity of Plasmodium falciparum antigens is a major obstacle to a broadly effective malaria vaccine but population genetics has rarely been used to guide vaccine design....Full Text Available

413

Consumer purchasing patterns in response to calorie labeling legislation in New York City  

UK PubMed Central (United Kingdom)

BackgroundObesity is a major public health threat and policies aimed at curbing this epidemic are emerging. National calorie labeling legislation is forthcoming and requires rigorous...Full Text Available

414

Construction and Characterization of Genetically Defined aro omp Mutants of Enterotoxigenic Escherichia coli and Preliminary Studies of Safety and Immunogenicity in Humans  

UK PubMed Central (United Kingdom)

Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea in travelers to countries where the disease is endemic and causes a major disease burden in the indigenous population,...Full Text Available

2001-08-01

415

Confronting the scientific obstacles to global control of tuberculosis  

UK PubMed Central (United Kingdom)

Tuberculosis (TB) is a major threat to global health, recently exacerbated by the emergence of highly drug-resistant forms of the disease-causing pathogen and synergy with HIV/AIDS. In 2006, the Stop...Full Text Available

2008-04-01

416

Concomitant use of ibuprofen and paracetamol and the risk of major clinical safety outcomes  

UK PubMed Central (United Kingdom)

AIMSTo evaluate and compare the risk of specific safety outcomes in patients prescribed ibuprofen and paracetamol concomitantly with those in patients prescribed ibuprofen or paracetamol...Full Text Available

2010-09-01

417

Computational approaches to discovering semantics in molecular biology  

Energy Technology Data Exchange (ETDEWEB)

One of the central questions of molecular biology is the discovery of the semantics of DNA. This discovery relies in a critical way on a variety of expensive computations. In order to solve these computations, both parallel computers and special-purpose hardware play a major role.

1989-07-01

418

Complete Sequencing of pNDM-HK Encoding NDM-1 Carbapenemase from a Multidrug-Resistant Escherichia coli Strain Isolated in Hong Kong  

UK PubMed Central (United Kingdom)

BackgroundThe emergence of plasmid-mediated carbapenemases, such as NDM-1 in Enterobacteriaceae is a major public health issue. Since they mediate resistance to...Full Text Available

419

Comparative study of nonlinear properties of EEG signals of normal persons and epileptic patients  

UK PubMed Central (United Kingdom)

BackgroundInvestigation of the functioning of the brain in living systems has been a major effort amongst scientists and medical practitioners. Amongst the various disorder of the...Full Text Available

420

Comparative in vitro activity of Meropenem, Imipenem and Piperacillin/tazobactam against 1071 clinical isolates using 2 different methods: a French multicentre study  

UK PubMed Central (United Kingdom)

BackgroundMeropenem is a carbapenem that has an excellent activity against many gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria. The major objective...Full Text Available

421

Comparative aspects of cortical neurogenesis in vertebrates  

UK PubMed Central (United Kingdom)

The mammalian neocortex consists of six layers. By contrast, the reptilian and avian cortices have only three, which are believed to be equivalent to layers I, V and VI of mammals. In mammals, the majority...Full Text Available

2007-08-01

422

Common Familial Colorectal Cancer Linked to Chromosome 7q31: a genome-wide analysis  

UK PubMed Central (United Kingdom)

Present investigations suggest that approximately 30% of colorectal cancer (CRC) cases arise on the basis of inherited factors. We hypothesize that the majority of inherited factors are moderately...Full Text Available

2008-11-01

423

Collapse and Restoration of MHC Class-I-Dependent Immune Privilege  

UK PubMed Central (United Kingdom)

The collapse of major histocompatiblity complex (MHC) class-I-dependent immune privilege can lead to autoimmune disease or fetal rejection. Pragmatic and instructive models are needed to clarify the...Full Text Available

2004-02-01

424

Clinical review: Patency of the circuit in continuous renal replacement therapy  

UK PubMed Central (United Kingdom)

Premature circuit clotting is a major problem in daily practice of continuous renal replacement therapy (CRRT), increasing blood loss, workload, and costs. Early clotting is related to bioincompatibility,...Full Text Available

2007-01-01

425

Climatic changes: a major challenge; Changement climatique: un defi majeur  

Energy Technology Data Exchange (ETDEWEB)

To sensitize the public opinion and change the energy consumption habits, the ADEME (french Agency for the environment and the energy mastership) published a document on the climatic change problem and its consequences. A state of the art of the situation, the international agreements and solutions are provided. (A.L.B.)

2001-07-01

426

Cholesterol and Heart Disease: Current Concepts in Pathogenesis and Treatment  

UK PubMed Central (United Kingdom)

One of the modifiable risk factors associated with coronary heart disease (CHD) is hypercholesterolemia. This paper reviews the major plasma lipids and how they relate to coronary heart disease. Among...Full Text Available

1986-08-01

427

China pursues major role in particle physics  

CERN Multimedia

Mao Zedong dreamed of splitting an electron; this was no idle diversion. According to natural dialectics, which formed the philosophical underpinnings of Marxism, the entire universe, from top to bottom, was seething with tension and change. (1 page)

2006-01-01

428

Cerebrospinal fluid zinc concentrations in febrile convulsions.  

UK PubMed Central (United Kingdom)

Zinc modulates the activity of glutamic acid decarboxylase, the rate limiting enzyme in the synthesis of gamma-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. Low cerebrospinal...Full Text Available

1995-10-01

429

Carotid Stenting vs Endarterectomy: New Results in Perspective  

UK PubMed Central (United Kingdom)

Carotid artery stenosis is a major risk factor for stroke, and treatments for this condition to decrease the risk of stroke include medical therapy, carotid endarterectomy (CEA), and, more recently,...Full Text Available

2010-12-01

430

Blood Flow and Pressure Telemetry.  

Science.gov (United States)

The major emphasis of this past year's research effort toward characterizing the responses of the cardiovascular system of the military working dog has been to obtain renal hemodynamic information from dogs involved in various stages of obedience, scoutin...

1973-01-01

431

Bistability of Mitochondrial Respiration Underlies Paradoxical Reactive Oxygen Species Generation Induced by Anoxia  

UK PubMed Central (United Kingdom)

Increased production of reactive oxygen species (ROS) in mitochondria underlies major systemic diseases, and this clinical problem stimulates a great scientific interest in the mechanism of ROS generation....Full Text Available

2009-12-01

432

Biomechanical Issues in Endovascular Device Design  

UK PubMed Central (United Kingdom)

The biomechanical nature of the arterial system and its major disease states provides a series of challenges to treatment strategies. Endovascular device design objectives have mostly centered on short-term...Full Text Available

2009-02-01

433

Application of rhenium-188 HEDP in bone metastases therapy  

International Nuclear Information System (INIS)

Radionuclide bone metastases therapy is a major achievement of nuclear medicine. Development of less radiotoxic and more effective radiopharmaceuticals is therefore a challenge for radiopharmacists and industry. This paper reviews the application of rhenium-188 HEDP as a reactor- or generator-produced nuclide for bone metastases therapy. (author)

434

Application of Cryopreserved Human Hepatocytes in Trichloroethylene Risk Assessment: Relative Disposition of Chloral Hydrate to Trichloroacetate and Trichloroethanol  

UK PubMed Central (United Kingdom)

BackgroundTrichloroethylene (TCE) is a suspected human carcinogen and a common ground-water contaminant. Chloral hydrate (CH) is the major metabolite of TCE formed in the liver by...Full Text Available

2006-08-01

435

Antibodies to synthetic peptides from the tubulin regulatory domain interact with tubulin and microtubules.  

UK PubMed Central (United Kingdom)

The carboxyl-terminal region of tubulin alpha and beta subunits plays a major role in regulating its assembly into microtubules and constitutes an essential domain for the selective interaction of microtubule-associated...Full Text Available

1988-09-01

436

Anti-erythrocyte autoantibody production in mice associated with the injection of rat erythrocytes.  

UK PubMed Central (United Kingdom)

Mice injected with rat erythrocytes developed anti-erythrocyte autoantibodies which reached a plateau at 4-12 weeks, then gradually declined until at about 24 weeks the majority of mice were negative....Full Text Available

1980-04-01

437

Anti-beta-endorphin immunoglobulin G in humans.  

UK PubMed Central (United Kingdom)

Human IgG specific for beta-endorphin was identified by enzyme-linked immunoabsorbent assay and isolated by affinity chromatography. From a sample of 27 subjects, three individuals with major depression...Full Text Available

1986-11-01

438

Analyzing the simplicial decomposition of spatial protein structures  

UK PubMed Central (United Kingdom)

BackgroundThe fast growing Protein Data Bank contains the three-dimensional description of more than 45000 protein- and nucleic-acid structures today. The large majority of the data...Full Text Available

439

An ALMT1 Gene Cluster Controlling Aluminum Tolerance at the Alt4 Locus of Rye (Secale cereale L.)  

UK PubMed Central (United Kingdom)

Aluminum toxicity is a major problem in agriculture worldwide. Among the cultivated Triticeae, rye (Secale cereale L.) is one of the most Al tolerant and represents an important potential...Full Text Available

2008-05-01

440

Age- and Gender-Related Differences in the Geometric Properties and Biomechanical Significance of Intracortical Porosity in the Distal Radius and Tibia  

UK PubMed Central (United Kingdom)

Cortical bone contributes the majority of overall bone mass and bears the bulk of axial loads in the peripheral skeleton. Bone metabolic disorders often are manifested by cortical microstructural changes...Full Text Available

2010-05-01

441

Adenomatous Polyposis Coli and Hypoxia-inducible Factor-1? Have an Antagonistic Connection  

UK PubMed Central (United Kingdom)

The tumor suppressor adenomatous polyposis coli (APC) is mutated in the majority of colorectal cancers and is best known for its role as a scaffold in a Wnt-regulated protein complex that determines...Full Text Available

2010-11-01

442

Adaptation of a Foot Plate for Use in an Isokinetic and Isotonic Leg Press  

UK PubMed Central (United Kingdom)

The use of isokinetic equipment and the leg press exercise have been major components of rehabilitation for the past several years when redeveloping muscular strength. Recently, closed kinetic chain...Full Text Available

1996-04-01

443

Acetylation of Histones and Transcription-Related Factors  

UK PubMed Central (United Kingdom)

The state of chromatin (the packaging of DNA in eukaryotes) has long been recognized to have major effects on levels of gene expression, and numerous chromatin-altering strategies—including...Full Text Available

2000-06-01

444

Accumulation of Long-Chain Glycosphingolipids during Aging Is Prevented by Caloric Restriction  

UK PubMed Central (United Kingdom)

BackgroundChronic kidney disease and end-stage renal disease are major causes of morbidity and mortality that are seen far more commonly in the aged population. Interestingly, kidney...Full Text Available

445

Accelerator technology program, January-June 1982. Status report  

Science.gov (United States)

The major projects of the Los Alamos National Laboratory's Accelerator Technology Division are discussed, covering activities that occurred during the first six months of calendar 1982.

1983-12-01

446

A neurodegenerative disease mutation that accelerates the clearance of apoptotic cells  

UK PubMed Central (United Kingdom)

Frontotemporal lobar degeneration is a progressive neurodegenerative syndrome that is the second most common cause of early-onset dementia. Mutations in the progranulin gene are a major cause of familial...Full Text Available

2011-03-15

447

A direct role for serum albumin in the cellular uptake of long-chain fatty acids.  

UK PubMed Central (United Kingdom)

The interaction of long-chain fatty acids with cells is important for their uptake and metabolism, as well as their involvement in signalling processes. The majority of long-chain fatty acids circulating...Full Text Available

1995-05-15

448

A comparative study of sexual dysfunction involving risperidone, quetiapine, and olanzapine  

UK PubMed Central (United Kingdom)

Background:With the advent of newer antipsychotic drugs, side effects such as sexual dysfunction have been a major contributor toward treatment compliance. There are only...Full Text Available

2009-10-01

449

A Sea Change in Eta Carinae  

CERN Document Server

Major stellar-wind emission features in the spectrum of Eta Car have recently decreased by factors of order 2 relative to the continuum. This is unprecedented in the modern observational record. The simplest, but unproven, explanation is a rapid decrease in the wind density.

2010-01-01

450

A Review of the Pathophysiology and Novel Treatments for Erectile Dysfunction  

UK PubMed Central (United Kingdom)

Erectile dysfunction (ED) affects up to 50% of men between the ages of 40 and 70. Treatment with PDE-5 inhibitors is effective in the majority of men with ED. However, PDE-5 inhibitors are not effective...Full Text Available

2010-01-01

451

A Motivation-Focused Weight Loss Maintenance Program is an Effective Alternative to a Skill-Based Approach  

UK PubMed Central (United Kingdom)

ObjectiveMaintaining weight loss is a major challenge in obesity treatment. Individuals often indicate that waning motivation prompts cessation of effective weight...Full Text Available

2011-02-01

452

A Dominant Role for the Immunoproteasome in CD8+ T Cell Responses to Murine Cytomegalovirus  

UK PubMed Central (United Kingdom)

Murine cytomegalovirus (MCMV) is an important animal model of human cytomegalovirus (HCMV), a β-Herpesvirus that infects the majority of the world's population and causes disease in neonates...Full Text Available

453

?Activation of the mitogen-activated protein kinase pathways by heat shock  

UK PubMed Central (United Kingdom)

In addition to inducing new transcriptional activities that lead within a few hours to the accumulation of heat shock proteins (Hsps), heat shock activates within minutes the major signaling transduction...Full Text Available

2002-04-01

454

3D Hepatic Cultures Simultaneously Maintain Primary Hepatocyte and Liver Sinusoidal Endothelial Cell Phenotypes  

UK PubMed Central (United Kingdom)

Developing in vitro engineered hepatic tissues that exhibit stable phenotype is a major challenge in the field of hepatic tissue engineering. However, the rapid dedifferentiation of...Full Text Available

455

Zephyr: A secure Internet process to streamline engineering  

Energy Technology Data Exchange (ETDEWEB)

Lawrence Livermore National Laboratory (LLNL) is implementing an Internet-based process pilot called `Zephyr` to streamline engineering and commerce using the Internet. Major benefits have accrued by using Zephyr in facilitating industrial collaboration, speeding the engineering development cycle, reducing procurement time, and lowering overall costs. Programs at LLNL are potentializing the efficiencies introduced since implementing Zephyr. Zephyr`s pilot functionality is undergoing full integration with Business Systems, Finance, and Vendors to support major programs at the Laboratory.

1998-05-12

456

Transportation cask decontamination and maintenance at the potential Yucca Mountain repository; Yucca Mountain Site characterization project  

Energy Technology Data Exchange (ETDEWEB)

This study investigates spent fuel cask handling experience at existing nuclear facilities to determine appropriate cask decontamination and maintenance operations at the potential Yucca Mountain repository. These operations are categorized as either routine or nonroutine. Routine cask decontamination and maintenance tasks are performed in the cask preparation area at the repository. Casks are taken offline to a separate cask maintenance area for major nonroutine tasks. The study develops conceptual designs of the cask preparation area and cask maintenance area. The functions, layouts, and major features of these areas are also described.

1992-04-01

457

The nucleotide sequence of a major species of leucine tRNA from bovine liver.  

UK PubMed Central (United Kingdom)

Through the use of a variety of post-labeling techniques, the nucleotide sequence of a major species of leucine tRNA from bovine liver was determined to be pG-G-U-A-G-C-G-U-G-m-G-C-ac-C-G-A-G-C-G-G-D-C-psi-A-A-G-G-C-m-G-C-U-G-G-A-psim-...Full Text Available

1980-02-25

458

Significance of major, minor and trace elements analysis of rocks by WDXRFS in litho geochemistry vis a vis uranium exploration in parts of India  

International Nuclear Information System (INIS)

This paper discusses essentially the role of WDXRFS based multi element data in uranium exploration, with special reference to India. The state of art MagiX-PRO WDXRFS with 4 kW end window x-ray tubes has been used in the present study as an indispensable geo-analytical tool for the analysis of major and selected trace elements at ppm to percentage level, with high precision and relatively better accuracy

2010-10-01

459

International Water Power and Dam Construction Handbook 1993  

Energy Technology Data Exchange (ETDEWEB)

In this handbook, technical reports on a number of hydro plants under construction are provided. In addition tables of compiled data are presented on a world-wide basis for the following: turbine and hydro generator contracts; hydropower resource potential and development; pumped storage plants; the major dams and hydro plants; roller compacted concrete dams and concrete faced rockfill dams; small hydropower. An address database of international organizations of relevance to hydropower development, national power authorities and nation committees of the International Commission an Large Dams is included. A final and major section of the handbook is a buyer's guide providing extensive company data and information on products and services. (UK)

1993-01-01

460

Innovative Design of New Geothermal Generating Plants  

Energy Technology Data Exchange (ETDEWEB)

This very significant and useful report assessed state-of-the-art geothermal technologies. The findings presented in this report are the result of site visits and interviews with plant owners and operators, representatives of major financial institutions, utilities involved with geothermal power purchases and/or wheeling. Information so obtained was supported by literature research and data supplied by engineering firms who have been involved with designing and/or construction of a majority of the plants visited. The interviews were conducted by representatives of the Bonneville Power Administration, the Washington State Energy Office, and the Oregon Department of Energy during the period 1986-1989. [DJE-2005

1989-07-01

461

Improvement of assessment methodology for fluid flow characteristics of passive flow control device  

International Nuclear Information System (INIS)

The objective of this study is to establish evaluation and verification guideline for the APR 1400 and to investigate the thermal-hydraulic characteristics for fluidic device is analyzed using FLUENT. The scope and major results of research are flow characteristics for fluidic device. In this study, three-dimensional numerical model for fluidic device is developed adequately for, and results are compared with experimental data performed by VAPER (VAlve Performance Evaluation test Rig) in KAERI with an aim to verify numerical simulation. In addition, the parametric study has also carried out to investigate the effect of major parameters such as velocity and pressure inside FD chamber.

2002-10-01

462

INEEL Advanced Radiotherapy Research Program Annual Report 2001  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.

2002-04-01

463

INEEL Advanced Radiotherapy Research Program Annual Report 2001  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.

2002-04-30

464

Hazardous waste and environmental trade: China`s issues  

Energy Technology Data Exchange (ETDEWEB)

By presenting some case studies, this paper analyzes China`s situation with regard to hazardous waste: its environmental trade, treatment, and management. The paper describes China`s experiences with the environmental trade of hazardous waste in both the internal and international market. Regulations for managing the import of waste are discussed, as are China`s major approaches to the trading of hazardous waste both at home and overseas. The major reasons for setting up the Asian-Pacific Regional Training Center for Technology Transfer and Environmental Sound Management of Wastes in China and the activities involved in this effort are also described. 1 tab.

1996-12-31

465

Energy conservation in the United Kingdom: a major industrial opportunity  

Energy Technology Data Exchange (ETDEWEB)

Energy conservation presents major opportunities to industry, both to improve its energy efficiency (hence its competitiveness and profitability) and to supply services and equipment. There are vast markets, both in the United Kingdom and overseas, but there are also barriers. There is reluctance on one hand to make new investment on the scale required. On the other hand, the problems of meeting a fragmented new demand are complicated by the fragmentation of the conservation supply industry. This calls for a new coherent, and innovative approach by both the conservation supply industry and the financial institutions. 3 tables.

1984-01-01

466

Astronomy in Ukraine  

CERN Document Server

The current and prospective status of astronomical research in Ukraine is discussed. A brief history of astronomical research in Ukraine is presented and the system organizing scientific activity is described, including astronomy education, institutions and staff, awarding higher degrees/titles, government involvement, budgetary investments and international cooperation. Individuals contributing significantly to the field of astronomy and their accomplishments are mentioned. Major astronomical facilities, their capabilities, and their instrumentation are described. In terms of the number of institutions and personnel engaged in astronomy, and of past accomplishments, Ukraine ranks among major nations of Europe. Current difficulties associated with political, economic and technological changes are addressed and goals for future research activities presented.

2005-01-01

467

Two and 8-azido photoaffinity probes. 2. Studies on the binding process of 2-5A synthetase by photosensitive ATP analogues  

International Nuclear Information System (INIS)

The photoaffinity probes [#gamma#-"3"2P]2-azidoATP (2-N_3ATP) and [#alpha#-"3"2P]8-azido-ATP (8-N_3ATP) were used to investigate the binding of ATP to highly purified 2-5A synthetase. 2-N_3APT and 8-N_3ATP are substrates for 2-5A synthetase. In this study the authors show that 2- and 8-N_3ATP are competitive inhibitors of the enzymatic conversion of ATP to 2-5A. Ultraviolet irradiation results in the photoinsertion of 2-N_3ATP and 8-N_3ATP into the enzyme. The covalent photoinsertion of [#alpha#-"3"2P]8-N_3ATP into the 2-5A synthetase is proportional to the inactivation of the enzyme as UV irradiation is increased. Photolabeling of 2-5A synthetase is saturated at 1.5 mM 2-N_3ATP and 2.0 mM 8-N_3ATP. Computer analysis of the curvilinear Scatchard plots of the 2-5A synthetase suggest the presence of high-affinity and low-affinity binding sites that may correspond to the acceptor and the 2'-adenylation sites of the enzyme. The competition of nucleotides for the ...

468

Toxicity of ultraviolet-irradiated halothane in mice  

Energy Technology Data Exchange (ETDEWEB)

One such agent is the widely used anesthetic, halothane. To study the toxicity of u.v. decomposed halothane, mice were exposed to anesthetic concentrations (1.3%) of non- and u.v.-irradiated halothane in oxygen for 90 min. Halothane sleeping times increased from 14.3 min to 72.5 min. Microsomal mixed function oxidase activity decreased, as shown by prolonged pentobarbital sleeping times 1 day after exposure to halothane and irradiated halothane (54.6 min and 149.1 min, respectively, as compared to a 34.6-min control). Quantitative and qualitative differences were found in the amount of (/sup 14/C)-pentobarbital metabolites excreted by u.v. irradiated halothane-exposed mice compared to either oxygen or non-irradiated halothane-exposed groups. In addition, serum glutamic-oxalacetic transaminase (SGOT) of irradiated halothane-exposed mice increased to 233% of the control values, and serum glutamic-pyruvic transaminase (SGPT) were 377% of control values. No significant changes in SGOT or ...

1982-01-01

469

Three novel mutations responsible for Cockayne syndrome group A  

International Nuclear Information System (INIS)

Cockayne syndrome (CS) is a rare autosomal recessive disease, which shows diverse clinical symptoms such as photosensitivity, severe mental retardation and developmental defects. CS cells are hypersensitive to killing by ultraviolet (UV)-irradiation and defective in transcription-coupled repair. Two genetic complementation groups in CS (CS-A and CS-B) have been identified. We analyzed mutations of the CSA gene in 5 CS-A patients and identified 3 types of mutations. Four unrelated CS-A patients (CS2OS, CS2AW, Nps2 and CS2SE) had a deletion including exon 4, suggesting that there is a founder effect on the CSA mutation in Japanese CS-A patients. Patient CS2SE was a compound heterozygote for this deletion and an amino acid substitution at the 106th glutamine to proline (Q106P) in the WD-40 repeat motif of the CSA protein, which resulted in a defective nucleotide excision repair. Patient Mps1 had a large deletion in the upstream region including exon 1 of the CSA gene. ...

2003-02-01

470

The earth is warming up while the sky is getting a chill; La terre se rechauffe, le ciel a un coup de froid  

Energy Technology Data Exchange (ETDEWEB)

The phenomenon of global warming, its causes and implications for the future, and the relationship between global warming and the depletion of the ozone layer are discussed. The Shindell model of the greenhouse effect, which is responsible for planetary warming, also contributes to the high altitude thinning of the ozone layer. While greenhouse gas emissions contribute to retaining infrared radiation, thus warming the surface of the earth, their effect is reduced at stratospheric altitudes resulting in reduced temperatures in this region. At this altitude temperatures can reach minus 90 degrees C, creating a whirlwind effect, with ice crystals forming at the heart of the vortex, causing the surface to accelerate chemical reactions which in turn leads to destruction of ozone. Although since the signing of the Montreal Protocol in 1987 the industrialized countries have significantly reduced their emissions of refrigerating gas (chlorofluorocarbons or CFC), which were considered to have ...

2001-03-01

471

The Sorcerer II Global Ocean Sampling Expedition: Expanding theUniverse of Protein Families  

Energy Technology Data Exchange (ETDEWEB)

Metagenomics projects based on shotgun sequencing of populations of micro-organisms yield insight into protein families. We used sequence similarity clustering to explore proteins with a comprehensive dataset consisting of sequences from available databases together with 6.12 million proteins predicted from an assembly of 7.7 million Global Ocean Sampling (GOS) sequences. The GOS dataset covers nearly all known prokaryotic protein families. A total of 3,995 medium- and large-sized clusters consisting of only GOS sequences are identified, out of which 1,700 have no detectable homology to known families. The GOS-only clusters contain a higher than expected proportion of sequences of viral origin, thus reflecting a poor sampling of viral diversity until now. Protein domain distributions in the GOS dataset and current protein databases show distinct biases. Several protein domains that were previously categorized as kingdom specific are shown to have GOS examples in other kingdoms. About ...

2006-03-23

472

Synthesis, crystal structure and photoluminescence of Eu-#alpha#-SiAlON  

International Nuclear Information System (INIS)

Eu-#alpha#-SiAlON (Eu_m_/_2Si_1_2_-_m_-_nAl_m_+_nO_nN_1_6_-_n) was synthesized with nominal compositions having small m and n values, by firing the powder mixture of Eu_2Si_5N_8, #alpha#-Si_3N_4, AlN, and Al_2O_3 at 1900 "oC for 6 h under 1 MPa nitrogen atmosphere. The ratio of the oxidation state of Eu"2"+/Eu"3"+ was estimated from the X-ray absorption fine structure (XAFS) measurement. The observed X-ray absorption near edge spectrum (XANES) showed that the Eu ion in Eu-#alpha#-SiAlON was mainly in divalent state but also coexisted with a small amount of Eu in the trivalent state. The crystal structure of Eu-#alpha#-SiAlON was refined by the Rietveld analysis of the X-ray powder diffraction patterns. The lattice constants of the samples increased with increasing m and n values. The excitation band of Eu-#alpha#-SiAlON ranged from the ultraviolet to the visible light region and a broad emission band centered at about 590 nm were observed. The emission intensity ...

2010-08-20

473

Studies of aerosol formation in power plant plumes - II. Secondary aerosol formation in the Navajo generating station plume  

Energy Technology Data Exchange (ETDEWEB)

Aerosol and gas measurements were made with the University of Minnesota Mobile Laboratory (UMML) during the VISTTA programme near Page, Arizona. The UMML was stationed on Zilnez Mesa approx. 65 km east of the Navajo coal-fired power plant. Measurements were made both in and out of the power plant plume and were made during the day and night. Measured parameters included aerosol size distributions, Aitken nuclei count, ozone and sulphur dioxide concentrations, the aerosol light scattering coefficient, and meteorological parameters including ultraviolet radiation intensity. Concentrations of NO and NO/SUB/x were occasionally measured. Data show clear evidence of gas-to-particle conversion in the plume with aerosol volume being added in the 0.01 MUm - 0.32 MUm dia. range and new particles being formed. The observed excess aerosol volume depends strongly upon the SO/SUB/2 concentrations and the time of day with none observed in plume parcels which were not exposed to ...

1981-01-01

474

Scaling method for fast Monte Carlo simulation of diffuse reflectance spectra from multilayered turbid media  

Science.gov (United States)

A scaling Monte Carlo method has been developed to calculate diffuse reflectance from multilayered media with a wide range of optical properties in the ultraviolet-visible wavelength range. This multilayered scaling method employs the photon trajectory information generated from a single baseline Monte Carlo simulation of a homogeneous medium to scale the exit distance and exit weight of photons for a new set of optical properties in the multilayered medium. The scaling method is particularly suited to simulating diffuse reflectance spectra or creating a Monte Carlo database to extract optical properties of layered media, both of which are demonstrated in this paper. Particularly, it was found that the root-mean-square error (RMSE) between scaled diffuse reflectance, for which the anisotropy factor and refractive index in the baseline simulation were, respectively, 0.9 and 1.338, and independently simulated diffuse reflectance was less than or equal to 5% for ...

2007-04-01

475

Photodegradation and photostabilization of weathered wood flour filled polyethylene composites  

Science.gov (United States)

Wood plastic composites (WPCs) have gained popularity as building materials because of their usefulness in replacing solid wood in a variety of applications. These composites are promoted as being low-maintenance, high-durability products. However, it has been shown that WPCs exposed to weathering may experience a color change and/or loss in mechanical properties. An important requirement for building materials used in outdoor applications is the retention of their aesthetic qualities and mechanical properties during service life. Therefore, it is critical to understand the photodegradation mechanisms of WPCs exposed to UV radiation and to develop approaches to stabilize these composites against ultraviolet light. In this dissertation, the surface chemistries of weathered composites (both unstabilized and stabilized) as well as the effect of weathering on the color fade and the retention of mechanical properties were characterized. Since different methods of ...

2003-01-01

476

Methods and results for calibration and track separation of a GEM based TPC using an UV-laser  

Energy Technology Data Exchange (ETDEWEB)

In the last 30 years high energy physics could write an impressive story of success. Since the introduction of the Standard Model (SM), it has met every experimental test. However the final confirmation has to prove the mechanism of electroweak symmetry breaking, which could not be confirmed yet. The most favored theory, which includes the introduction of a Higgs field, could not be verified experimentally. Furthermore there is clear evidence, that the SM is only a low energy description of nature and its principles, as the SM describes only 4 % of the known matter in the universe. There are two different approaches in accelerator driven high energy physics to clarify the open questions. The Large Hadron Collider (LHC) have a good opportunity to measure some of the missing pieces with its high center of mass energy. The International Linear Collider (ILC) will then measure their parameters with high precision. To guarantee this high precision the detectors have to be able to identify ...

2008-12-15

477

Luminescent properties of Eu3+-activated Sr3B2SiO8: A red-emitting phosphor for white light-emitting diodes  

International Nuclear Information System (INIS)

Single-phased Sr3B2SiO8:Eu3+ phosphor was prepared by a solid-state method at 1020 oC. The luminescence spectra showed that Sr3B2SiO8:Eu3+ phosphor can be effectively excited by near ultraviolet light (393 nm) and blue light (464 nm). When excited at 393 or 464 nm Sr3B2SiO8:Eu3+ exhibited the main emission peaks at 611 and 620 nm, which resulted from the supersensitive 5D0#->#7F2 transition of Eu3+. The luminescence intensity of Sr3B2SiO8:Eu3+ at 611 and 620 nm reached the maximum when the doping content of Eu3+ was 4.5 mol%. Its chromaticity coordinates (0.646, 0.354) were very close to the NTSC standard values (0.67, 0.33). Thus, Sr3B2SiO8:Eu3+ is considered to be an efficient red-emitting phosphor for long-UV InGaN-based light-emitting diodes. - Highlights: ? Sr3B2SiO8:Eu3+ was synthesized using solid-state reaction method for the first time. ? The phosphor can be efficiently excited by the near-UV chips and gives strong red emission. ? The phosphor is a ...

2011-07-01

478

Lifetime measurements of singlet ungerade states in isotopic molecular nitrogen  

International Nuclear Information System (INIS)

Full text: In the upper layers of the Earth's atmosphere, molecular nitrogen absorbs the extreme ultraviolet (XUV) solar radiation. The absorption is associated with dipole-allowed excitation of states of singlet ungerade symmetry ("1#SIGMA#"+_u and "1#PI#_u), which are known to undergo predissociation due to coupling with a mainfold of "1#PI#_u states. We determined new N_2 isotopic lifetimes of many "1#SIGMA#"+_u and "1#PI#_u states via line broadening measurements in the frequency domain. Ultrahigh resolution XUV + UV ionization spectra were recorded (bandwidth #approx# 250 MHz, resolving power 10"7), from which the natural linewidth, i.e. lifetime, was determined. These lifetimes provide new information about the predissociation of the singlet ungerade states in N_2. Tunable narrowband XUV radiation was produced by successively pulsed amplification of cw dye laser radiation, frequency doubling the pulsed visible laser beam into the UV and frequency tripling the ...

2004-07-19

479

Investigation of ultrafast photothermal surface expansion and diffusivity in GaAs via laser-induced dynamic gratings  

Energy Technology Data Exchange (ETDEWEB)

This thesis details the first direct ultrafast measurements of the dynamic thermal expansion of a surface and the temperature dependent surface thermal diffusivity using a two-color reflection transient grating technique. Studies were performed on p-type, n-type, and undoped GaAs(100) samples over a wide range of temperatures. By utilizing a 90 fs ultraviolet probe with visible excitation beams, the effects of interband saturation and carrier dynamics become negligible; thus lattice expansion due to heating and subsequent contraction caused by cooling provided the dominant influence on the probe. At room temperature a rise due to thermal expansion was observed, corresponding to a maximum net displacement of {approximately} 1 {Angstrom} at 32 ps. The diffracted signal was composed of two components, thermal expansion of the surface and heat flow away from the surface, thus allowing a determination of the rate of expansion as well as the surface thermal diffusivity, ...

1992-04-01

480

Interface engineering in chalcopyrite thin film solar devices  

Energy Technology Data Exchange (ETDEWEB)

Successful interface engineering requires compositional and electronic material characterization as a prerequisite for understanding and intentionally generating interfaces in photovoltaic devices. The paper gives an overview with several examples, all referring to Cu(In,Ga)(S,Se){sub 2} ('CIGSSe')-based solar cells, with an emphasis on characterization using highly specialized methods, such as elastic recoil detection analysis, X-ray emission spectroscopy and photoelectron spectroscopy using synchrotron and ultraviolet light for excitation, inverse photoemission spectroscopy and Kelvin probe force microscopy. First, the determination of the depth profile of the band gap energy E{sub g} in the absorber layer is demonstrated. The modification of E{sub g} towards both interfaces is discussed in terms of beneficial electronic effects. Next, the interface between absorber and buffer layers with alternative and promising non-toxic materials is ...

2006-06-15

481

Identification of a nucleoside triphosphate binding site on calf thymus RNA polymerase II  

Energy Technology Data Exchange (ETDEWEB)

A nucleoside triphosphate binding site on calf thymus RNA polymerase II was identified by using photoaffinity analogues of adenosine 5'-triphosphate and guanosine 5'-triphosphate. Both radiolabeled 8-azidoadenosine 5'-triphosphate (8-N3ATP) and radiolabeled 8-azidoguanosine 5'-triphosphate (8-N3GTP) bound to a single polypeptide of this enzyme. This polypeptide has a molecular mass of 37 kilodaltons and an isoelectric point of 5.4. Ultraviolet (UV) irradiation was necessary for photolabeling to occur. In addition, no labeling occurred when the probe was prephotolyzed or when the enzyme was inactivated. Furthermore, photolabeling of the enzyme could be decreased by preincubation with natural substrates. To provide evidence that the radiolabeled polypeptide forms a part of the domain of the nucleoside triphosphate binding site, experiments were performed using unlabeled 8-N3ATP. Although this unlabeled analogue was not a substrate ...

1986-01-14

482

Growth and characterization of new semi-organic L-proline strontium chloride monohydrate single crystals  

International Nuclear Information System (INIS)

The present communication deals with the synthesis, single crystal growth and characterization of a new nonlinear optical material L-proline strontium chloride monohydrate (L-PSCM). Single crystals have been grown using the slow solvent evaporation technique. Single crystal XRD analysis confirmed that the crystal belongs to the orthorhombic structure with lattice parameter a=6.6966(3) A, b=12.4530(5) A, c=15.2432(5) A and space group P2_12_12_1. Presence of various functional groups in L-PSCM and protonation of the ions were confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis. The melting point of the single crystal was found to be 126 "oC using DSC. Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 226 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 5.82 eV. Capacitance and dielectric-loss measurements were carried out at different temperatures in the ...

2011-01-01

483

Facile synthesis and the sensitized luminescence of europium ions-doped titanate nanowires  

International Nuclear Information System (INIS)

Europium (Eu) ions-doped titanate nanowires were synthesized via a sol-gel-hydrothermal chemistry and they were found to be roll multilayered trititanate-type nanowires intercalated with Eu3+ and alkali ions. The average diameter was about 20 nm for nanowires synthesized in NaOH solution and about 10 nm for nanowires synthesized in KOH solution. Under ultraviolet excitation the nanowires showed bright red emission corresponding to 5D0-7Fj of Eu3+ ions at room temperature, which was attributed to the non-radiative energy transfer from the surrounding Ti-O octahedral nanosheets to the central Eu3+ ions in interlayer. The luminescent properties of nanowires were influenced by the type of co-intercalated alkali ions, doping degree, hydrothermal and annealing temperatures. The intensity ratio of 5D0-7F2 to 5D0-7F1 of titanate nanowires intercalated with Eu3+ and Na+ ions was higher than that of titanate nanowires intercalated with Eu3+ and K+ ions. The emission ...

2009-04-15

484

Exposure of Finnish population to solar UV radiation and consequent carcinogenic effects  

Energy Technology Data Exchange (ETDEWEB)

Depletion of stratospheric ozone increases irradiance of terrestrial ultraviolet (UV) radiation at short wavelengths, which may be harmful to the human health. To understand quantitatively the risks caused by increasing UV radiation to the Finnish population, the actual UV exposure of the population has to be assessed. It was shown that the snow reflection increases the UV exposure to the face and eyes particularly in the northern Finland. In 1993 exceptionally low ozone levels persisted up to the end of May, which resulted in a theoretical increase in the annual UV dose ranging from 8 % to 13 % in Finland. The maximal increase in the measured erythemally effective dose rate was 34 % on 23 April, when compared with the theoretical normal value. During this study exposure models have been developed. The models have been combined them with Green`s radiation transfer model to estimate annual facial UV doses received by different groups of Finnish population. Also, an ...

1996-12-31

485

Effective laser luminescence of nanocomposites Eu(TTA)2(Ph3PO)2NO3-polyvinylpyrrolidone  

International Nuclear Information System (INIS)

Thin films (1-10 ?m thickness) of nanocomposites (NC) based on organic coordinated compound (OCC) Eu(TTA)2(Ph3PO)2NO3 (where TTA is thenoyl trifluoroacetonate (C8H5F3O2S), Ph3PO - triphenylphosphine (C6H5PO) and polymer-polyvinylpyrrolidone ((C6H9NO)n) (PVP)) were obtained by chemical methods and with different molar ratios into organic polymer matrix. NC have been characterized by measurements of optical transmission, excitation spectra of photoluminescence (PL) and photoluminescence of NC at different concentrations of Eu(TTA)2(Ph3PO)2NO3 in NC. In the optical transmission of NC, the characteristic parameters of NC such as threshold absorbance, dependence on the concentration of the organic coordinated compound in NC, etc., have been determined The displacement of threshold absorption to infrared is observed with increasing of the concentration of the coordination material in NC. The excitation spectrum of photoluminescence of NC led the range from 200 to 400 nm energy at which takes ...

2011-07-07

486

Automated ARXPS goniometer/diffractometer. Final report, April 1995--March 1997  

Energy Technology Data Exchange (ETDEWEB)

This award provided for an automated computer-controlled goniometer/diffractometer/manipulator with hot and cold stages and data acquisition system that was interfaced with the high resolution Scienta ESCA-300 X-ray photoelectron spectrometer at Lehigh University. The automation allows angular dependent X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) data to be accurately and rapidly collected without the very time-consuming and labor-intensive manual method that was previously required. It also provides for automated multi-sample analyses, collecting both wide survey scans and selected binding energy range analyses, with complete computer control and data storage. This allows 24 hour data collection without requiring the continuous presence of operators. The overall result is a greater productivity for the XPS laboratory, approximately doubling the output of the laboratory. While the automated computer-controlled ...

1998-07-01

487

An ultraviolet-inducible adenosine-adenosine cross-link reflects the catalytic structure of the Tetrahymena ribozyme  

Energy Technology Data Exchange (ETDEWEB)

When a shortened enzymatic version of the Tetrahymena self-splicing intervening sequence (IVS) RNA is placed under catalytic conditions and irradiated at 254 nm, a covalent cross-link forms with high efficiency. The position of the cross-link was mapped by using three independent methods: RNase H digestion, primer extension with reverse transcriptase, and partial hydrolysis of end-labeled RNA. The cross-link is chemically unusual in that it joins two adenosines, A57 and A95. Formation of this cross-link depends upon the identity and concentration of divalent cations present and upon heat-cool renaturation of the IVS in a manner that parallels conditions required for optimal catalytic activity. Furthermore, cross-linking requires the presence of sequences within the core structure, which is conserved among group I intervening sequences and necessary for catalytic activity. Together these correlations suggest that a common folded structure permits cross-linking and catalytic activity. ...

1990-06-12

488

Amplified spontaneous emission from ZnO in n-ZnO/ZnO nanodots-SiO_2 composite/p-AlGaN heterojunction light-emitting diodes  

International Nuclear Information System (INIS)

This study demonstrates amplified spontaneous emission (ASE) of the ultraviolet (UV) electroluminescence (EL) from ZnO at #lambda##approx#380 nm in the n-ZnO/ZnO nanodots-SiO_2 composite/p- Al_0_._1_2Ga_0_._8_8N heterojunction light-emitting diode. A SiO_2 layer embedded with ZnO nanodots was prepared on the p-type Al_0_._1_2Ga_0_._8_8N using spin-on coating of SiO_2 nanoparticles followed by atomic layer deposition (ALD) of ZnO. An n-type Al-doped ZnO layer was deposited upon the ZnO nanodots-SiO_2 composite layer also by the ALD technique. High-resolution transmission electron microscopy (HRTEM) reveals that the ZnO nanodots embedded in the SiO_2 matrix have diameters of 3-8 nm and the wurtzite crystal structure, which allows the transport of carriers through the thick ZnO nanodots-SiO_2 composite layer. The high quality of the n-ZnO layer was manifested by the well crystallized lattice image in the HRTEM picture and the low-threshold optically pumped stimulated ...

2009-04-22

489

Utilization of cold in LNG baseload and peakshaving plants  

Science.gov (United States)

This report presents the results of a survey of the uses of the refrigeration available from vaporizing liquefied natural gas. The major emphasis of the study is on peakshaving plants, which liquefy and regasify domestic gas; the minor emphasis is on base-load terminals, which gasify imported LNG continuously. There are 54 full-scale LNG peakshaving plants in the US and several others under construction. The US has three operating base-load import terminals. One more is under construction and several more large terminals have been proposed. There are at least 12 foreign base-load import terminals in operation, and more are under construction or are proposed. The report presents a survey of operating conditions for about 15 large domestic peakshaving plants. It also presents published design data for the existing US import terminals, for the major proposed import terminals, and for the major overseas import terminals. The ...

1979-10-15

490

The expression of stratigraphic surfaces and deltaic geometries during the scale change from well data to seismic data; Traduction des surfaces stratigraphiques et des geometries deltaiques lors du passage de l`echelle puits a l`echelle sismique  

Energy Technology Data Exchange (ETDEWEB)

The sedimentary geometry is determined by several types of stratigraphic surfaces: transgressive surfaces (TS), maximum flooding surfaces (MFS) and downward shift surfaces (DS). They are organized hierarchically into major and minor surfaces from the facies stacking-pattern. These surfaces which are observable on well logs and cores structure the sedimentary architecture and are, therefore, the best candidates to form major seismic reflectors. The well (logs and cores) to seismic (surface seismic) passage involves inherently a change of observation scale. That is from a high resolution sequence stratigraphy (metric to pluri-metric) to a sequence stratigraphy s.l. (decametric to pluri-decametric). This passage is composed of two phases. The first phase consists of the validation of density and sonic logs whose product corresponds to the acoustic impedance. The second phase allows for the modelling of the geological cross section of a field in a ...

1996-12-31

491

Serum immunoglobulin E and hyaluronate levels in children living along major roads  

Energy Technology Data Exchange (ETDEWEB)

To assess the effects of automobile exhaust on human health, we determined serum concentrations of total immunoglobulin E and hyaluronate in 185 schoolchildren who lived in a district that contained major roads. Serum immunoglobulin E levels were elevated in children who had asthma or wheezing, but levels did no t differ with respect to distance of their homes from the major roads. Serum hyaluronate levels were higher in children who lived less than 50 m from the roadside, compared with children who resided a greater distance from roads. The difference, however, was significant only in a subgroup of children in whom immunoglobulin E levels exceeded 250 IU/ml. Our results suggest that serum hyaluronate levels in children reflect the effects of traffic-related air pollution. Children with high immunoglobulin E levels appeared to be particularly susceptible to the effects of automobile exhaust. 34 refs., 2 figs., 3 tabs.

1996-11-01

492

Oil shale today : thoughts on why the majors stay away  

Energy Technology Data Exchange (ETDEWEB)

This article discussed potential reasons why most major oil companies are not currently investing in oil shale resources. At present, only Shell, Chevron-Texaco, and ExxonMobil are engaged in oil shale pilot schemes. It was suggested that one of the reasons oil companies are reluctant to become involved is due to weak responses to experimental leasing programs conducted by the federal government of the United States, which are not favourable for commercial-scale operations. A federally sponsored leasing program and clear unconventional resource energy policies are needed, and unconventional oil resources must be developed in order to prevent escalating oil prices. The economics of oil shale recovery are equivalent to those obtained by Alberta's oil sands operators. Large amounts of char and hydrogen in the oil shale add value. However, oil shale processing has significant environmental impacts. Major oil companies in Brazil and China ...

2008-07-15

493

Nuclear energy, its social impact to the environment. The renewable energy sources, a viable alternative  

International Nuclear Information System (INIS)

The authors present arguments against nuclear energy and pro renewable energy sources. Thus, the water used in Uranium mining and primary ore processing becomes contaminated in long lived radioisotopes and so a threat for local ecosystems and communities. Then, during the fabrication, enrichment, and handling of nuclear fuel the workers are exposed to radiations and dangerous accidental radioactive leaks can occur. But, by far, the most menacing aspect of nuclear power exploitation remains the human errors in operating the nuclear plants which can result in major accidents like that from Chernobyl which spread radioactivity all over the Europe. The equipment used in nuclear facilities which is highly contaminated as well as the burned fuel implies transportation and long term storage which also present high risks. The major advantage of the nuclear energy consists in its very low environment impact and its null contribution to the greenhouse ...

1996-03-15

494

Multielement determination of major-to-ultratrace elements in salmon egg by ICP-AES and ICP-MS  

Energy Technology Data Exchange (ETDEWEB)

The multielement determination of major-to-ultratrace elements in salmon egg was carried out by ICP-AES and ICP-MS. First, salmon eggs (30 eggs used) were digested with conc. nitric acid and 60% perchloric acid by heating almost to dryness repeatedly. Finally, the residues of salmon eggs were dissolved in 1 M nitric acid and the sample solutions were analyzed by ICP-AES and ICP-MS. About 40 elements could be determined over the concentration range in 9 orders of magnitude. The concentrations of bio-essential elements, such as Zn, Fe, and Cu, in salmon egg were 10-100 times higher than those in human blood serum. In addition, the major-to-ultratrace elements in cell cytoplasm and cell membrane were separately determined in a similar manner to those in whole egg cell. The concentrations of most bio-essential elements were higher in cell cytoplasm than in cell membrane, while those of Fe and Cu were higher in cell membrane than in cell cytoplasm ...

2002-04-01

495

Gulf of Mexico petroleum accumulations a review of recent studies on sources of the oils, modes of source rock maturation and oil migration  

Energy Technology Data Exchange (ETDEWEB)

Recent organic geochemical studies differ radically in their interpretation of the origin of the Gulf coast oils. However all studies since (and including) Thompson, et al. 1989, emphasize the considerable geographic variation in genetic oil types and are in generalized agreement as to the genetic oil types present and their spatial and stratigraphic relationships. In particular it is accepted that the Gulf rim (both north and south) is encircled by a ring of Mesozoic carbonate-sourced oils and that there is also at least one major deep water trend of carbonate-sourced oils in the northern Gulf. It is also generally agreed that many of the Gulf rim oils are of Oxfordian-Kimmeridgian age, though some, like the Sunniland oils of Florida, are of lower Cretaceous origin. Major disagreement still occurs over the sources of the Louisiana offshore oils and onshore Wilcox reservoired oils. One {open_quotes}school of thought{close_quotes} assigns all ...

1996-09-01

496

Environmental pollutant isotope measurements and natural radioactivity assessment for North Tushki area, south western desert, Egypt  

Energy Technology Data Exchange (ETDEWEB)

Natural radioactive materials under certain conditions can reach hazardous radiological levels. The natural radionuclide ({sup 238}U, {sup 232}Th, {sup 40}K) contents of rock samples at various locations in the North Tushki area were investigated using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for the absorbed dose rate of gamma radiation. The equivalent radium (R{sub eq}) and the external hazard index (H{sub ex}) which resulted from the natural radionuclides in soil are also calculated and tabulated. The studied samples have been collected from various rock exposures in the North Tushki area. The distribution of major oxides, U and Th were studied. It is found that the enrichment and depletion of the major oxides are mainly due to the effect of hydrothermal alteration, which caused mobility of some major oxides, which increases some elements and decreases others. It is ...

2002-09-01

497

Computed radiography for major airway in pediatrics  

International Nuclear Information System (INIS)

This paper shows the efficacy of computed radiography for major airway in pediatrics. For this purpose, we examined 40 children (range 2 weeks to 14 years; mean 2.3 years) using Fuji Computed Radiography (FCR) and radiation dose using pediatric phantom under FCR and conventional film and screen system. In comparison study with FCR and conventional film and screen system, FCR images are superior to conventional system in all cases. Scorings were done for the quality of the image of the pharynx, the trachea, and both main bronchi. In phantom study to check radiation dose, radiation dose could be reduced 1/6 of the value using high speed film and screen and 1/15 of the value using conventional speed film and screen. FCR also showed clear airway images in all cases but technical failure to evaluate the clinical lesion. These results suggest that FCR is the adequate imaging modality to evaluate the major airway in children. (author).

1986-01-01