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Sample records for root surface radiated

  1. [Changes of root biomass, root surface area, and root length density in a Populus cathayana plantation].

    PubMed

    Yan, Hui; Liu, Guang-quan; Li, Hong-sheng

    2010-11-01

    By using soil core method, the biomass, surface area, and length density of roots < or =2 mm and 2-5 mm in diameter in a 50-year-old Populus cathayana plantation on the northern slope of Qinling Mountains were determined during growth season. Among the roots <5 mm in diameter, those < or =2 mm and 2-5 mm in diameter accounted for 77.8% and 22.2% of the total root biomass, respectively. The surface area and length density of the roots < or =2 mm in diameter accounted for more than 97% of the total, and those of the roots 2-5 mm in diameter only occupied less than 3%. The biomass, surface area, and root length density of roots < or =2 mm in diameter decreased with soil depth, while those of the roots 2-5 mm in diameter were the least in 20-30 cm soil layer. The biomass, surface area, and length density of roots < or =2 mm in diameter were significantly correlated with soil organic matter and available nitrogen, but no significant correlations were found for the roots 2-5 mm in diameter. PMID:21360997

  2. Scaling of root surfaces with lasers: an in vitro study

    NASA Astrophysics Data System (ADS)

    Sievers, Martin; Frentzen, Matthias; Kosina, A.; Koort, Hans J.

    1993-12-01

    The purpose of this study was to examine the effects of root preparation with different laser types in order to replace hand-held instruments in periodontal surgery. The advantage should be a more selective and atraumatic technique promoting periodontal regeneration. The root surfaces of extracted human teeth were irradiated with pulsed laser radiation of IR lasers (CO2, Ho:YAG and Tm:YAG laser) and excimer lasers (ArF* and XeCl* laser). For the light microscopic investigation the specimen were cut into undecalcified sections of 10 micrometers thickness and stained with Toluidine-blue.

  3. Lunar Surface Radiation Display

    NASA Astrophysics Data System (ADS)

    Burke, James; Albalat, Andrea Jaime; Tlustos, Reinhard

    2014-05-01

    Effects of the lunar surface environment can be observed with a simple passive experiment consisting of small material samples placed in view of a lander or rover camera. This paper will describe, advocate and demonstrate the creation, ideally by students or young professionals, of a small standard sample holder, for example a string of different glass beads in front of a white or detector background, that can be replicated and installed on any of the coming series of lunar surface spacecraft. Effects of solar and cosmic ionizing radiation and local temperature, such as darkening and annealing, will be readily apparent in different kinds of glass, plastic and crystalline beads. Costs of preparation and installation, and impact on the main mission, can be kept to a level essentially negligible in proportion to project budgets.

  4. Factors influencing the future need for treatment of root surfaces.

    PubMed

    Ettinger, R L; Hand, J S

    1994-10-01

    This paper discusses the current status of root surface caries in the elderly population and the need for treatment of this condition in the future. Although root surface exposure and root caries have been reported for adults at all ages, the people at greatest risk for these conditions are the elderly. In the United States, life expectancy and the population aged 65 years and older has increased substantially, and the proportion of the elderly population who are dentate has increased and is projected to increase further. Utilization of dental services by the elderly is similar to that of employed adults. Interpretation of studies of the prevalence and incidence of root surface caries are difficult due to differences in sampling, definition of lesions, and reporting conventions. Root surface caries prevalence is related to age and continues to be a significant problem for this population as they age. Factors that may affect the future need for treatment are explored. PMID:7986448

  5. ROOT DENSITY AND ROOT SURFACE AREA OF SELECTED PACIFIC NORTHWEST CROPS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root length density and root surface area were evaluated for soft white winter and spring wheat (Triticum aestivum L), spring peas (Pisum sativum) and winter canola (Brassica napus L.) for at least two years at two locations (Pendleton, OR and Pullman, WA). Spring wheat was sampled at 3-leaf, anthe...

  6. Surface modification of tooth root canal after application of an X-ray opaque waveguide

    NASA Astrophysics Data System (ADS)

    Dostálová, T.; Jelínková, H.; Šulc, J.; Němec, M.; Koranda, P.; Bartoňová, M.; Radina, P.; Miyagi, M.; Shi, Y.-W.; Matsuura, Y.

    The interest in endodontic use of dental laser systems has been increasing. With the development of thin and flexible delivery systems for various wavelengths, laser applications in endodontics may become even more desirable. The aim of this study is to check the X-ray opacity of a hollow waveguide and to observe the results after laser root canal treatment. The root canal systems of 10 molars were treated endodontically by laser. For the laser radiation source, an Er:YAG laser system generating a wavelength of 2940 nm and an Alexandrite laser system generating a wavelength of 375 nm were used. The hollow waveguide used was checked under X-ray . A root canal surface treated by laser radiation was analyzed by a scanning electron microscope (SEM). The special hollow glass waveguide used was visible in the root canal system under X-ray imaging. Surface modification of the root canal after laser treatment was not found. After conventional treatment the root canal was enlarged. The surface was covered with a smear layer. After application of both laser systems, the smear layer was removed. The resulting canal surface was found to be clean and smooth. Under SEM observation open dentinal tubules were visible. No cracks were present, nor were surface modifications observed.

  7. In vitro attachment of human gingival fibroblasts to root surfaces.

    PubMed

    Aleo, J J; De Renzis, F A; Farber, P A

    1975-11-01

    Human gingival fibroblasts were used to study the in vitro attachment of cells to the root surface of periodontally-involved teeth. The portion of the root exposed to the disease process had little or no cell attachment; on the remainder of the root, the cells attached normally. Prior extraction of the roots with phenol-water or the mechanical removal of diseased cementum allowed the cells to attach normally. All things being equal, the extrapolation of these data to an in vivo situation dictates that a clinical success would depend upon complete removal of toxic materials from diseased cementum or the removal of the cementum itself. PMID:1058944

  8. Root canal surface after application of an x-ray opaque waveguide

    NASA Astrophysics Data System (ADS)

    Dostalova, Tatjana; Jelinkova, Helena; Bartonova, Marie; Sulc, Jan; Nemec, Michal; Koranda, Petr; Miyagi, Mitsunobu; Shi, Yi-Wei; Matsuura, Yuji

    2004-05-01

    The success of endodontic treatment depends on the methods used for shaping, cleaning, disinfecting, and sealing of a root canal. In the last few decades, big progress has been achieved in the application of the following methods: manual instrumentation, sonic and ultrasonic devices, and rotary instruments. The procedures used in the root canal system preparation result in a smear layer creation. The aim of this study was to give more precision to the smear layer removal using laser radiation. The root canal systems of 20 human teeth were treated endodontically. As laser radiation sources, Er:YAG laser system generating a wavelength of 2940 nm (rep. rate 1.5 Hz, spot size diameter 320 um, number of pulses 55, energy 100 mJ) and Alexandrite laser system generating a wavelength of 375 nm (rep. rate 1 Hz, spot size diameter 320 um, number of pulses 200, energy 1 mJ) were used. As a delivery system, a hollow glass waveguide with the special X-ray contrast cover was used. The flexible waveguide was moved via root canal and the laser radiation cleaned the wall surface. After application of Er:YAG laser radiation, the smear layer was fully removed, the surface was clean and smooth, and in the SEM investigation the open dentinal tubules were visible. No cracks were determined. The surface modifications were also not observed after endodontic preparation as well as Alexandrite laser radiation therapy. The whole treatment can be checked by X-ray machine.

  9. Surface Power Radiative Cooling Tests

    SciTech Connect

    Vaughn, Jason; Schneider, Todd

    2006-01-20

    Terrestrial nuclear power plants typically maintain their temperature through convective cooling, such as water and forced air. However, the space environment is a vacuum environment, typically 10-8 Torr pressure, therefore in proposed missions to the lunar surface, power plants would have to rely on radiative cooling to remove waste heat. Also, the Martian surface has a very tenuous atmosphere (e.g. {approx}5 Torr CO2), therefore, the main heat transfer method on the Martian surface is also radiative. Because of the lack of atmosphere on the Moon and the tenuous atmosphere on Mars, surface power systems on both the Lunar and Martian surface must rely heavily on radiative heat transfer. Because of the large temperature swings on both the lunar and the Martian surfaces, trying to radiate heat is inefficient. In order to increase power system efficiency, an effort is underway to test various combinations of materials with high emissivities to demonstrate their ability to survive these degrading atmospheres to maintain a constant radiator temperature improving surface power plant efficiency. An important part of this effort is the development of a unique capability that would allow the determination of a materials emissivity at high temperatures. A description of the test capability as well as initial data is presented.

  10. Surface Power Radiative Cooling Tests

    NASA Astrophysics Data System (ADS)

    Vaughn, Jason; Schneider, Todd

    2006-01-01

    Terrestrial nuclear power plants typically maintain their temperature through convective cooling, such as water and forced air. However, the space environment is a vacuum environment, typically 10-8 Torr pressure, therefore in proposed missions to the lunar surface, power plants would have to rely on radiative cooling to remove waste heat. Also, the Martian surface has a very tenuous atmosphere (e.g. ~5 Torr CO2), therefore, the main heat transfer method on the Martian surface is also radiative. Because of the lack of atmosphere on the Moon and the tenuous atmosphere on Mars, surface power systems on both the Lunar and Martian surface must rely heavily on radiative heat transfer. Because of the large temperature swings on both the lunar and the Martian surfaces, trying to radiate heat is inefficient. In order to increase power system efficiency, an effort is underway to test various combinations of materials with high emissivities to demonstrate their ability to survive these degrading atmospheres to maintain a constant radiator temperature improving surface power plant efficiency. An important part of this effort is the development of a unique capability that would allow the determination of a materials emissivity at high temperatures. A description of the test capability as well as initial data is presented.

  11. Nd:YAG Laser Irradiation of the Tooth Root Surface Inhibits Demineralization and Root Surface Softening Caused by Minocycline Application

    PubMed Central

    Watanabe, Tomohisa; Mitani, Akio; Ting, Chun-Chan; Osawa, Kazuhiro; Nagahara, Ayako; Satoh, Sohta; Fujimura, Takeki; Takahashi, Shinko; Iwamura, Yuki; Murakami, Taeko; Noguchi, Toshihide

    2013-01-01

    Abstract Objective: The aim of this study was to investigate the effect of laser irradiation on root surface demineralization caused by local drug delivery systems (DDS), and to evaluate the effect of sealing on drug retention. Background data: The duration of supportive periodontal treatment (SPT) has increased with increasing life expectancy. Repeated root planing and DDS application during SPT should be reconsidered with regard to their effects on the root surface. Methods: Extracted human teeth were collected, cut into 3×3×2 mm root dentin specimens, and divided randomly into eight groups with various combinations of Nd:YAG laser power (0, 0.5, 1, and 2 W), with and without DDS (minocycline HCl). Specimen microhardness and calcium (Ca) solubility were measured after treatment. The specimens (control and laser and DDS groups) were examined by scanning electron microscopy. Forty SPT patients were recruited, to assess the effect of periodontal pocket sealing on drug retention. Results: Laser irradiation increased the microhardness of root specimens in an energy-dependent manner. Calcium solubilities decreased from the 0 W+DDS group to the 2.0 W+DDS group. The mean Ca solubilities in the 1.0 W+DDS and 2.0 W+DDS groups were significantly lower than in the 0 W+DDS group (p<0.01, p<0.001, respectively). Laser irradiation counteracted the softening effect of DDS. Morphologic change was observed in the 2W+DDS group; however, no morphologic changes were observed in the control and the 1W+DDS groups. The mean concentration of minocycline in the periodontal pocket 24 h after application was 252.79±67.50 μg/mL.Conclusions: Laser irradiation of the root surface inhibited the softening and decalcification caused by minocycline HCl. Sealing the periodontal pockets effectively improved drug retention. These results suggest that the combination of laser irradiation and DDS could benefit patients receiving repeated SPT. PMID:24219120

  12. Effect of diode laser radiation in root canal wall dentine: a microbiological study

    NASA Astrophysics Data System (ADS)

    Gutknecht, Norbert; Conrads, Georg; Apel, Christian; Schubert, Claus; Lampert, Friedrich

    2000-03-01

    The aim of this study was to investigate the antibacterial effect of a diode laser in deep root canal dentine. The microbial colonization of root canal dentine can lead to failures in conventional endodontic treatment if only an inadequate bacterial reduction is achieved through canal treatment and chemical disinfection. 100 micrometer, 300 micrometer and 500 micrometer bovine dentine slices obtained by longitudinal sections were sterilized and inoculated on one side with an Enterococcus faecalis suspension. Laser radiation was performed on the opposite side with the diode laser, emits light at 810 nm and operates in the continuous wave mode (cw). Radiation was performed using a 400 micrometer tapered fiber tip at an angle of approx. 5 degrees to the surface over a period of 30 s. The output power at the distal end of the tip was 0.6 watt. The bacteria were then eluted through vibration and cultured on blood agar plates. The colony count reflected the antibacterial effect of laser radiation as a function of the layer thickness. A mean bacterial reduction of 74% was achieved even with a 500 micrometer thick slice. This investigation indicates that the diode laser can support the bacterial reduction in endodontic treatment.

  13. Development of a space radiation Monte Carlo computer simulation based on the FLUKA and ROOT codes.

    PubMed

    Pinsky, L S; Wilson, T L; Ferrari, A; Sala, P; Carminati, F; Brun, R

    2001-01-01

    This NASA funded project is proceeding to develop a Monte Carlo-based computer simulation of the radiation environment in space. With actual funding only initially in place at the end of May 2000, the study is still in the early stage of development. The general tasks have been identified and personnel have been selected. The code to be assembled will be based upon two major existing software packages. The radiation transport simulation will be accomplished by updating the FLUKA Monte Carlo program, and the user interface will employ the ROOT software being developed at CERN. The end-product will be a Monte Carlo-based code which will complement the existing analytic codes such as BRYNTRN/HZETRN presently used by NASA to evaluate the effects of radiation shielding in space. The planned code will possess the ability to evaluate the radiation environment for spacecraft and habitats in Earth orbit, in interplanetary space, on the lunar surface, or on a planetary surface such as Mars. Furthermore, it will be useful in the design and analysis of experiments such as ACCESS (Advanced Cosmic-ray Composition Experiment for Space Station), which is an Office of Space Science payload currently under evaluation for deployment on the International Space Station (ISS). FLUKA will be significantly improved and tailored for use in simulating space radiation in four ways. First, the additional physics not presently within the code that is necessary to simulate the problems of interest, namely the heavy ion inelastic processes, will be incorporated. Second, the internal geometry package will be replaced with one that will substantially increase the calculation speed as well as simplify the data input task. Third, default incident flux packages that include all of the different space radiation sources of interest will be included. Finally, the user interface and internal data structure will be melded together with ROOT, the object-oriented data analysis infrastructure system. Beyond

  14. Surface wave chemical detector using optical radiation

    DOEpatents

    Thundat, Thomas G.; Warmack, Robert J.

    2007-07-17

    A surface wave chemical detector comprising at least one surface wave substrate, each of said substrates having a surface wave and at least one measurable surface wave parameter; means for exposing said surface wave substrate to an unknown sample of at least one chemical to be analyzed, said substrate adsorbing said at least one chemical to be sensed if present in said sample; a source of radiation for radiating said surface wave substrate with different wavelengths of said radiation, said surface wave parameter being changed by said adsorbing; and means for recording signals representative of said surface wave parameter of each of said surface wave substrates responsive to said radiation of said different wavelengths, measurable changes of said parameter due to adsorbing said chemical defining a unique signature of a detected chemical.

  15. Profilometric analysis of root surfaces after using various polishing agents

    PubMed Central

    Jana, Anjan; Chakraborty, Abhijit; Pal, Tamal Kanti; Datta, Someswar

    2016-01-01

    Background: Polishing is an important step in oral prophylaxis procedure which retards further accumulation of plaque on the root surfaces. Though polishing was done with various abrasive particles with different sizes over a long period of time, it was never been highlighted to evaluate the ideal polishing material and the particle size that would produce the ideal surface smoothness (Ra <0.2 μm). Materials and Methods: The present study was carried out on 70 periodontally involved, caries-free extracted human teeth from 42 patients. All the teeth were collected from the region of incisors, canines, and premolars. In vitro scaling and root planing were performed by piezoelectric scaler and Gracey's area specific curettes, respectively. All the teeth were grouped at random into control and experimental. The collections of abrasive materials were done directly from the market, and the different particle sizes were prepared in the laboratory. Experimentation: The polishing was done at a constant speed of 200 rpm with cylindrical nylon bristle brush followed by rubber prophy cup. Each group belonging to control and experimental was subjected to profilometric study for evaluation of surface roughness. Results: Regular polishing abrasives are not able to produce the surface smoothness of our desire level (i.e., Ra <0.2 μm), which can be achieved only by submicron-sized particles. Conclusion: Regular size polishing particles available in the market (>5 μm) are not able to produce the surface smoothness <0.2 μm. Only, submicron sized particles are able to produce the desired smoothness. PMID:27041833

  16. What is the Best Root Surface Treatment for Avulsed Teeth?

    PubMed Central

    Tuna, Elif B; Yaman, Duygu; Yamamato, Seiko

    2014-01-01

    Dental avulsion is the most severe type of traumatic tooth injuries since it causes damage to several structures and results in avulsion of the tooth from its socket. Management protocols for avulsed teeth should include management of the pulp and periodontal ligament (PDL) cells in order to improve the long-term prognosis and survival of these teeth. The prognosis of the treatment as well as the survival of an avulsed tooth depends on intrinsic and extrinsic factors, such as the duration of the tooth’s extra-alveolar period, replantation time, the type of storage medium, PDL status and duration of splinting. Recent research has led to the development of storage media. However, there is not yet a single solution that fulfills all requirements to be considered as the ideal medium for temporary storage of avulsed teeth, and research on this field should carry on. On the other hand in case of delayed replantation, due to the great risk of tooth loss after avulsion, different root surface treatments have been proposed to prevent and delay root resorption before replantation. For this purpose, researchers have applied some different root surface treatment modalities in delayed replantation of avulsed teeth. Several protocols have been used to maintain PDL viability; some involve fluorides, steroids, sodium alendronate, enamel matrix derivatives (EMD) and basic fibroblast growth factor (bFGF, FGF-2). Among these applications, bFGF shows promising results in the regeneration of natural tooth structures and tissues. Better understanding of mechanism of bFGF may help to improve new technologies of regeneration of tooth structures. PMID:25317212

  17. Root hairs aid soil penetration by anchoring the root surface to pore walls.

    PubMed

    Bengough, A Glyn; Loades, Kenneth; McKenzie, Blair M

    2016-02-01

    The physical role of root hairs in anchoring the root tip during soil penetration was examined. Experiments using a hairless maize mutant (Zea mays: rth3-3) and its wild-type counterpart measured the anchorage force between the primary root of maize and the soil to determine whether root hairs enabled seedling roots in artificial biopores to penetrate sandy loam soil (dry bulk density 1.0-1.5g cm(-3)). Time-lapse imaging was used to analyse root and seedling displacements in soil adjacent to a transparent Perspex interface. Peak anchorage forces were up to five times greater (2.5N cf. 0.5N) for wild-type roots than for hairless mutants in 1.2g cm(-3) soil. Root hair anchorage enabled better soil penetration for 1.0 or 1.2g cm(-3) soil, but there was no significant advantage of root hairs in the densest soil (1.5g cm(-3)). The anchorage force was insufficient to allow root penetration of the denser soil, probably because of less root hair penetration into pore walls and, consequently, poorer adhesion between the root hairs and the pore walls. Hairless seedlings took 33h to anchor themselves compared with 16h for wild-type roots in 1.2g cm(-3) soil. Caryopses were often pushed several millimetres out of the soil before the roots became anchored and hairless roots often never became anchored securely.The physical role of root hairs in anchoring the root tip may be important in loose seed beds above more compact soil layers and may also assist root tips to emerge from biopores and penetrate the bulk soil. PMID:26798027

  18. Root hairs aid soil penetration by anchoring the root surface to pore walls

    PubMed Central

    Bengough, A. Glyn; Loades, Kenneth; McKenzie, Blair M.

    2016-01-01

    The physical role of root hairs in anchoring the root tip during soil penetration was examined. Experiments using a hairless maize mutant (Zea mays: rth3–3) and its wild-type counterpart measured the anchorage force between the primary root of maize and the soil to determine whether root hairs enabled seedling roots in artificial biopores to penetrate sandy loam soil (dry bulk density 1.0–1.5g cm−3). Time-lapse imaging was used to analyse root and seedling displacements in soil adjacent to a transparent Perspex interface. Peak anchorage forces were up to five times greater (2.5N cf. 0.5N) for wild-type roots than for hairless mutants in 1.2g cm−3 soil. Root hair anchorage enabled better soil penetration for 1.0 or 1.2g cm−3 soil, but there was no significant advantage of root hairs in the densest soil (1.5g cm−3). The anchorage force was insufficient to allow root penetration of the denser soil, probably because of less root hair penetration into pore walls and, consequently, poorer adhesion between the root hairs and the pore walls. Hairless seedlings took 33h to anchor themselves compared with 16h for wild-type roots in 1.2g cm−3 soil. Caryopses were often pushed several millimetres out of the soil before the roots became anchored and hairless roots often never became anchored securely.The physical role of root hairs in anchoring the root tip may be important in loose seed beds above more compact soil layers and may also assist root tips to emerge from biopores and penetrate the bulk soil. PMID:26798027

  19. Reflective overcoats for radiation control surfaces

    NASA Technical Reports Server (NTRS)

    White, Susan M.

    1991-01-01

    Theoretical models are developed to predict the surface properties of a coating layer composed of particles of a known size distribution, applied to an opaque substrate, such as a metal or reaction cured glass (RCG). The surface temperature attained at radiative equilibrium by an overcoated surface subject to a given heat flux is calculated. The incident radiation was assumed to exhibit the spectral distribution characteristic of a black body at different temperatures or equivalently, having different peak wavelengths, with the energy level scaled to give a range of desired surface radiative heat fluxes. This approach allows a straightforward comparison of the thernal response of a surface to incident radiation having the energy predominantly in a characteristic wavelength band and a well-defined spectral distribution. The ratio of the radiative heat flux to the total heat flux was varied, and the different geometric and material parameters of such overcoat layers were explored. The model was applied to representative surface heating rates to the Aeroasssisted Flight Experiment (AFE) and to Aeroassisted Space Transfer Vehicles (ASTVs). The predicted radiative energy flux to the surface of the AFE vehicle gives a single-point comparison of the surface temperatures attained with and without a selective-reflector overcoat on the vehicle surface. The specific objective of this work is to identify the most desirable radiative properties of an overcoat/substrate system for this environment.

  20. The effect of post surface treatments on the bond strength of fiber posts to root surfaces.

    PubMed

    Tuncdemir, Ali Riza; Yildirim, Cihan; Güller, Fatma; Ozcan, Erhan; Usumez, Aslihan

    2013-01-01

    The aim of the present study was to evaluate the influence of post surface treatment methods on the push-out bond strength of adhesively luted quartz fiber posts. Thirty freshly extracted and endodontically treated human incisor teeth were prepared for quartz fiber posts. The posts were submitted to three different surface treatments (n = 10), including no treatment, 50-µm aluminum-oxide (Al(2)O(3)) airborne-particle abrasion and Er:YAG laser (10 Hz, 150 mJ) irradiation. The posts were luted with resin cement. Each root was sectioned perpendicularly to its long axis to create specimens of 1-mm thickness. After the specimens were stored in distilled water at 37°C for 24 h, their push-out bond strength was tested using a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed by two-way ANOVA (α = .05). The two-way ANOVA indicated that push-out test values did not vary significantly according to surface treatments applied (control, airborne particle abrasion, Er:YAG laser irradiation) (p > 0.05), however, values varied according to the root segments (cervical, middle, and apical) (p < 0.01). The push-out bond strength values of the coronal root sections were the highest (p < 0.05) and there were no significant differences between the middle and apical root sections in push-out bond strength of fiber posts (p > 0.05). Air-borne particle abrasion or Er:YAG laser irradiation applied on the quartz fiber posts did not affect the push-out bond strengths relative to the root surfaces. The highest bond strength was observed in the cervical third of the roots in all groups. PMID:22274875

  1. Salinity-induced reduction in root surface area and changes in major root and shoot traits at the phytomer level in wheat.

    PubMed

    Robin, Arif Hasan Khan; Matthew, Cory; Uddin, Md Jasim; Bayazid, Khandaker Nafiz

    2016-06-01

    The aim of this study was to investigate the effect of salinity stress on root growth at the phytomer level in wheat to provide novel site-specific understanding of salinity damage in roots. Seedlings of 13 wheat varieties were grown hydroponically. Plants were exposed to three concentrations of NaCl, 0 (control), 50 and 100mM, from 47 days after sowing. In a destructive harvest 12 days later we determined the number of live leaves, adventitious roots, seminal roots and newly formed roots at the youngest phytomer; length and diameter of main axes; and length and diameter of root hairs and their number per millimetre of root axis. Elongation rate of main axes and root hair density were then derived. Root surface area at each root-bearing phytomer (Pr) was mechanistically modelled. New root formation was increased by salt exposure, while number of live leaves per plant decreased. The greatest salinity effect on root axis elongation was observed at the youngest roots at Pr1 and Pr2. Both the 50mM and the 100mM levels of salinity reduced root hair length by approximately 25% and root hair density by 40% compared with the control whereas root hairs alone contributed around 93% of the estimated total root surface area of an individual tiller. Decrease in main axis length of new roots, root hair density and root hair length combined to reduce estimated root surface area by 36-66% at the higher NaCl concentration. The varietal response towards the three salinity levels was found to be trait-specific. The data highlight reduction in root surface area as a major but previously largely unrecognized component of salinity damage. Salinity resistance is trait-specific. Selection for retention of root surface area at a specific phytomer position following salt exposure might be useful in development of salinity-tolerant crop varieties. PMID:26951370

  2. Surface radiation budget for climate applications

    NASA Technical Reports Server (NTRS)

    Suttles, J. T. (Editor); Ohring, G. (Editor)

    1986-01-01

    The Surface Radiation Budget (SRB) consists of the upwelling and downwelling radiation fluxes at the surface, separately determined for the broadband shortwave (SW) (0 to 5 micron) and longwave (LW) (greater than 5 microns) spectral regions plus certain key parameters that control these fluxes, specifically, SW albedo, LW emissivity, and surface temperature. The uses and requirements for SRB data, critical assessment of current capabilities for producing these data, and directions for future research are presented.

  3. Red food coloring stain: new, safer procedures for staining nematodes in roots and egg masses on root surfaces.

    PubMed

    Thies, Judy A; Merrill, Sharon B; Corley, E Luther

    2002-06-01

    Acid fuchsin and phloxine B are commonly used to stain plant-parasitic nematodes in roots and egg masses on root surfaces, respectively. Both stains can be harmful to both the user and the environment and require costly waste disposal procedures. We developed safer methods to replace both stains using McCormick Schilling red food color. Eggs, juveniles, and adults of Meloidogyne incognita stained in roots with red food color were equally as visible as those stained with acid fuchsin. Egg masses stained with red food color appeared as bright-red spheres on the root surfaces and were highly visible even without magnification. Replacement of acid fuchsin and phloxine B with red food color for staining nematodes is safer for the user and the environment, and eliminates costly waste disposal of used stain solutions. PMID:19265929

  4. First global WCRP shortwave surface radiation budget dataset

    NASA Technical Reports Server (NTRS)

    Whitlock, C. H.; Charlock, T. P.; Staylor, W. F.; Pinker, R. T.; Laszlo, I.; Ohmura, A.; Gilgen, H.; Konzelman, T.; Dipasquale, R. C.; Moats, C. D.

    1995-01-01

    Shortwave radiative fluxes that reach the earth's surface are key factors that influence atmospheric and oceanic circulations as well as surface climate. Yet, information on these fluxes is meager. Surface site data are generally available from only a limited number of observing stations over land. Much less is known about the large-scale variability of the shortwave radiative fluxes over the oceans, which cover most of the globe. Recognizing the need to produce global-scale fields of such fluxes for use in climate research, the World Climate Research Program has initiated activities that led to the establishment of the Surface Radiation Budget Climatology Project with the ultimate goal to determine various components of the surface radiation budget from satellite data. In this paper, the first global products that resulted from this activity are described. Monthly and daily data on a 280-km grid scale are available. Samples of climate parameters obtainable from the dataset are presented. Emphasis is given to validation and limitations of the results. For most of the globe, satellite estimates have bias values between +/- 20 W/sq m and root mean square (rms) values are around 25 W/sq m. There are specific regions with much larger uncertainties however.

  5. Conditional dependence of evaporative fraction on surface and root-zone soil moisture and its application to soil moisture retrieval

    NASA Astrophysics Data System (ADS)

    Ryu, D.; Akuraju, V.

    2013-12-01

    Thermal infrared (TIR) or evapotranspiration (ET) estimates from space have been gaining growing attention as an input to retrieve root-zone soil moisture. The rationale behind the approach is that i) there exists a strong causal link between the evapotranspiration and the vegetation canopy temperature and ii) under water-limited conditions soil water available for transpiration controls the evaporative fraction (EF) or the actual evapotranspiration (AET) to potential evapotranspiration (PET) ratio of vegetated surfaces. In this work, we examine the relationship between EF and surface to root-zone soil moisture content collected from two study sites (wheat and pasture fields) at the Dookie research farm site in Victoria, Australia. EF estimated from the eddy covariance system is compared with soil moisture content under various ranges of soil depths (5 depths from surface to 120 cm), net radiation, soil wetness and biomass. In both wheat and pasture fields, EF is highly correlated with surface (0-8 cm) soil moisture when the soil surface is bare-to-lightly vegetated, but the correlation decreases as vegetation grows or as the net radiation decreases. On the other hand, EF shows strong correlation with root-zone soil moisture during the growing seasons of the fields. Under similar ranges of soil moisture and net radiation, EF can have different ranges depending on the vegetation height and density. These results indicate the importance of biophysical parameters and processes in estimating surface and root-zone soil moisture contents using surface energy flux. We propose an exponential and a spherical model to fit EF versus soil moisture and show how their uncertainty changes with biophysical parameters.

  6. Tooth root growth impairment after mantle radiation in long-term survivors of Hodgkin's disease

    SciTech Connect

    McGinnis, J.P. Jr.; Hopkins, K.P.; Thompson, E.I.; Hustu, H.O.

    1985-10-01

    The tooth root growth impairment that resulted from 35 to 37 Gy mantle port radiation in 47 long-term survivors of childhood Hodgkin's disease was quantified and related to specific age groups and categories of teeth. Root measurements of the mandibular permanent canines, first and second premolars, and first and second molars were made from sequential panoramic radiographs taken at the time of radiation therapy and after the closure of root apexes. The severity of root growth impairment was greatest in patients who received radiation during the early stages of odontogenesis. With later stages of odontogenesis, and as the age increased at the time of treatment, less impairment occurred. The potential difficulties of using repeated panoramic radiographs to assess tooth lengths in longitudinal studies also were discussed.

  7. Tooth root growth impairment after mantle radiation in long-term survivors of Hodgkin's disease.

    PubMed

    McGinnis, J P; Hopkins, K P; Thompson, E I; Hustu, H O

    1985-10-01

    The tooth root growth impairment that resulted from 35 to 37 Gy mantle port radiation in 47 long-term survivors of childhood Hodgkin's disease was quantified and related to specific age groups and categories of teeth. Root measurements of the mandibular permanent canines, first and second premolars, and first and second molars were made from sequential panoramic radiographs taken at the time of radiation therapy and after the closure of root apexes. The severity of root growth impairment was greatest in patients who received radiation during the early stages of odontogenesis. With later stages of odontogenesis, and as the age increased at the time of treatment, less impairment occurred. The potential difficulties of using repeated panoramic radiographs to assess tooth lengths in longitudinal studies also were discussed. PMID:3863857

  8. Arabidopsis thaliana sku mutant seedlings show exaggerated surface-dependent alteration in root growth vector

    NASA Technical Reports Server (NTRS)

    Rutherford, R.; Masson, P. H.

    1996-01-01

    Roots of wild-type Arabidopsis thaliana seedlings in the Wassilewskija (WS) and Landsberg erecta (Ler) ecotypes often grow aslant on vertical agar surfaces. Slanted root growth always occurs to the right of the gravity vector when the root is viewed through the agar surface, and is not observed in the Columbia ecotype. Right-slanted root growth is surface-dependent and does not result directly from directional environmental stimuli or gradients in the plane of skewing. We have isolated two partially dominant mutations in WS (sku1 and sku2) that show an exaggerated right-slanting root-growth phenotype on agar surfaces. The right-slanting root-growth phenotype of wild-type and mutant roots is not the result of diagravitropism or of an alteration in root gravitropism. It is accompanied by a left-handed rotation of the root about its axis within the elongation zone, the rate of which positively correlates with the degree of right-slanted curvature. Our data suggest that the right-slanting root growth phenotype results from an endogenous structural asymmetry that expresses itself by a directional root-tip rotation.

  9. Arabidopsis thaliana sku mutant seedlings show exaggerated surface-dependent alteration in root growth vector.

    PubMed

    Rutherford, R; Masson, P H

    1996-08-01

    Roots of wild-type Arabidopsis thaliana seedlings in the Wassilewskija (WS) and Landsberg erecta (Ler) ecotypes often grow aslant on vertical agar surfaces. Slanted root growth always occurs to the right of the gravity vector when the root is viewed through the agar surface, and is not observed in the Columbia ecotype. Right-slanted root growth is surface-dependent and does not result directly from directional environmental stimuli or gradients in the plane of skewing. We have isolated two partially dominant mutations in WS (sku1 and sku2) that show an exaggerated right-slanting root-growth phenotype on agar surfaces. The right-slanting root-growth phenotype of wild-type and mutant roots is not the result of diagravitropism or of an alteration in root gravitropism. It is accompanied by a left-handed rotation of the root about its axis within the elongation zone, the rate of which positively correlates with the degree of right-slanted curvature. Our data suggest that the right-slanting root growth phenotype results from an endogenous structural asymmetry that expresses itself by a directional root-tip rotation. PMID:8756492

  10. Root Surface Bio-modification with Erbium Lasers- A Myth or a Reality??

    PubMed Central

    Lavu, Vamsi; Sundaram, Subramoniam; Sabarish, Ram; Rao, Suresh Ranga

    2015-01-01

    The objective of this literature review was to critically review the evidence available in the literature regarding the expediency of erbium family of lasers for root bio modification as a part of periodontal therapy. The literature search was performed on the Pubmed using MeSH words such as "lasers/therapeutic use, scaling, dental calculus, tooth root/anatomy and histology, ultrasonic therapy". The studies were screened and were grouped as follows: those evaluating a) efficacy for calculus removal with the Erbium family of laser b) root surface changes following Er YAG and Er Cr YSGG application c) comparative studies of the Er YAG, Er Cr YSGG lasers versus conventional methods of root surface modification d) Bio compatibility of root surface following Erbium laser treatment e) Studies on the combined efficacy of laser root modification with conventional methods towards root surface bio-modification f) Studies on effectiveness of root surface bio-modification prior to root coverage procedures. In conclusion, the erbium family has a proven anti-bacterial action, predictable calculus removal, minimal root substance removal, and appears to favor cell attachment. The Erbium family of lasers appears to be a useful adjunct for the management of periodontal disease. PMID:25713635

  11. [Improvement of root parameters in land surface model (LSM )and its effect on the simulated results].

    PubMed

    Cai, Kui-ye; Liu, Jing-miao; Zhang, Zheng-qiu; Liang, Hong; He, Xiao-dong

    2015-10-01

    In order to improve root parameterization in land surface model, the sub-model for root in CERES-Maize was coupled in the SSiB2 after calibrating of maize parameters in SSiB2. The effects of two improved root parameterization schemes on simulated results of land surface flux were analyzed. Results indicated that simulation accuracy of land surface flux was enhanced when the root module provided root depth only with the SSiB2 model (scheme I). Correlation coefficients between observed and simulated values of latent flux and sensible flux increased during the whole growing season, and RMSE of linear fitting decreased. Simulation accuracy of CO2 flux was also enhanced from 121 days after sowing to mature period. On the other hand, simulation accuracy of the flux was enhanced when the root module provided root depth and root length density simultaneously for the SSiB2 model (scheme II). Compared with the scheme I, the scheme II was more comprehensive, while its simulation accuracy of land surface flux decreased. The improved root parameterization in the SSiB2 model was better than the original one, which made simulated accuracy of land-atmospheric flux improved. The scheme II overestimated root relative growth in the surface layer soil, so its simulated accuracy was lower than that of the scheme I. PMID:26995920

  12. The radiation from apertures in curved surfaces

    NASA Technical Reports Server (NTRS)

    Pathak, P. H.; Kouyoumjian, R. G.

    1973-01-01

    The geometrical theory of diffraction is extended to treat the radiation from apertures or slots in convex, perfectly-conducting surfaces. It is assumed that the tangential electric field in the aperture is known so that an equivalent, infinitesimal source can be defined at each point in the aperture. Surface rays emanate from this source which is a caustic of the ray system. A launching coefficient is introduced to describe the excitation of the surface ray modes. If the field radiated from the surface is desired, the ordinary diffraction coefficients are used to determine the field of the rays shed tangentially from the surface rays. The field of the surface ray modes is not the field on the surface; hence if the mutual coupling between slots is of interest, a second coefficient related to the launching coefficient must be employed. In the region adjacent to the shadow boundary, the component of the field directly radiated from the source is presented by Fock-type functions. In the illuminated region the incident radiation from the source (this does not include the diffracted field components) is treated by geometrical optics. This extension of the geometrical theory of diffraction is applied to calculate the radiation from slots on elliptic cylinders, spheres and spheroids.

  13. Polysaccharide extraction from Sphallerocarpus gracilis roots by response surface methodology.

    PubMed

    Ma, Tingting; Sun, Xiangyu; Tian, Chengrui; Luo, Jiyang; Zheng, Cuiping; Zhan, Jicheng

    2016-07-01

    The extraction process of Sphallerocarpus gracilis root polysaccharides (SGRP) was optimized using response surface methodology with two methods [hot-water extraction (HWE) and ultrasonic-assisted extraction (UAE)]. The antioxidant activities of SGRP were determined, and the structural features of the untreated materials (HWE residue and UAE residue) and the extracted polysaccharides were compared by scanning electron microscopy. Results showed that the optimal UAE conditions were extraction temperature of 81°C, extraction time of 1.7h, liquid-solid ratio of 17ml/g, ultrasonic power of 300W and three extraction cycles. The optimal HWE conditions were 93°C extraction temperature, 3.6h extraction time, 21ml/g liquid-solid ratio and three extraction cycles. UAE offered a higher extraction yield with a shorter time, lower temperature and a lower solvent consumption compared with HWE, and the extracted polysaccharides possessed a higher antioxidant capacity. Therefore, UAE could be used as an alternative to conventional HWE for SGRP extraction. PMID:27032488

  14. Mitigation of radiation induced surface contamination

    DOEpatents

    Klebanoff, Leonard E.; Stulen, Richard H.

    2003-01-01

    A process for mitigating or eliminating contamination and/or degradation of surfaces having common, adventitious atmospheric contaminants adsorbed thereon and exposed to radiation. A gas or a mixture of gases is introduced into the environment of a surface(s) to be protected. The choice of the gaseous species to be introduced (typically a hydrocarbon gas, water vapor, or oxygen or mixtures thereof) is dependent upon the contaminant as well as the ability of the gaseous species to bind to the surface to be protected. When the surface and associated bound species are exposed to radiation reactive species are formed that react with surface contaminants such as carbon or oxide films to form volatile products (e.g., CO, CO.sub.2) which desorb from the surface.

  15. How and why do root apices sense light under the soil surface?

    PubMed Central

    Mo, Mei; Yokawa, Ken; Wan, Yinglang; Baluška, František

    2015-01-01

    Light can penetrate several centimeters below the soil surface. Growth, development and behavior of plant roots are markedly affected by light despite their underground lifestyle. Early studies provided contrasting information on the spatial and temporal distribution of light-sensing cells in the apical region of root apex and discussed the physiological roles of plant hormones in root responses to light. Recent biological and microscopic advances have improved our understanding of the processes involved in the sensing and transduction of light signals, resulting in subsequent physiological and behavioral responses in growing root apices. Here, we review current knowledge of cellular distributions of photoreceptors and their signal transduction pathways in diverse root tissues and root apex zones. We are discussing also the roles of auxin transporters in roots exposed to light, as well as interactions of light signal perceptions with sensing of other environmental factors relevant to plant roots. PMID:26442084

  16. Reverse surface-polariton cherenkov radiation

    NASA Astrophysics Data System (ADS)

    Tao, Jin; Wang, Qi Jie; Zhang, Jingjing; Luo, Yu

    2016-08-01

    The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections.

  17. Reverse surface-polariton cherenkov radiation.

    PubMed

    Tao, Jin; Wang, Qi Jie; Zhang, Jingjing; Luo, Yu

    2016-01-01

    The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections. PMID:27477061

  18. Reverse surface-polariton cherenkov radiation

    PubMed Central

    Tao, Jin; Wang, Qi Jie; Zhang, Jingjing; Luo, Yu

    2016-01-01

    The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections. PMID:27477061

  19. Parametric Study of Variable Emissivity Radiator Surfaces

    NASA Technical Reports Server (NTRS)

    Grob, Lisa M.; Swanson, Theodore D.

    2000-01-01

    The goal of spacecraft thermal design is to accommodate a high function satellite in a low weight and real estate package. The extreme environments that the satellite is exposed during its orbit are handled using passive and active control techniques. Heritage passive heat rejection designs are sized for the hot conditions and augmented for the cold end with heaters. The active heat rejection designs to date are heavy, expensive and/or complex. Incorporating an active radiator into the design that is lighter, cheaper and more simplistic will allow designers to meet the previously stated goal of thermal spacecraft design Varying the radiator's surface properties without changing the radiating area (as with VCHP), or changing the radiators' views (traditional louvers) is the objective of the variable emissivity (vary-e) radiator technologies. A parametric evaluation of the thermal performance of three such technologies is documented in this paper. Comparisons of the Micro-Electromechanical Systems (MEMS), Electrochromics, and Electrophoretics radiators to conventional radiators, both passive and active are quantified herein. With some noted limitations, the vary-e radiator surfaces provide significant advantages over traditional radiators and a promising alternative design technique for future spacecraft thermal systems.

  20. Surface contributions to radiated sound power.

    PubMed

    Marburg, Steffen; Lösche, Eric; Peters, Herwig; Kessissoglou, Nicole

    2013-06-01

    This paper presents a method to identify the surface areas of a vibrating structure that contribute to the radiated sound power. The surface contributions of the structure are based on the acoustic radiation modes and are computed for all boundaries of the acoustic domain. The surface contributions are compared to the acoustic intensity, which is a common measure for near-field acoustic energy. Sound intensity usually has positive and negative values that correspond to energy sources and sinks on the surface of the radiating structure. Sound from source and sink areas partially cancel each other and only a fraction of the near-field acoustic energy reaches the far-field. In contrast to the sound intensity, the surface contributions are always positive and no cancelation effects exist. The technique presented here provides a method to localize the relevant radiating surface areas on a vibrating structure. To illustrate the method, the radiated sound power from a baffled square plate is presented. PMID:23742325

  1. Enzyme and root activities in surface-flow constructed wetlands.

    PubMed

    Kong, Ling; Wang, Yu-Bin; Zhao, Li-Na; Chen, Zhang-He

    2009-07-01

    Sixteen small-scale wetlands planted with four plant species were constructed for domestic wastewater purification. The objective of this study was to determine the correlations between contaminant removal and soil enzyme activity, root activity, and growth in the constructed wetlands. The results indicated that correlations between contaminant removal efficiency and enzyme activity varied depending on the contaminants. The removal efficiency of NH4+ was significantly correlated with both urease and protease activity in all wetlands, and the removal of total phosphorus and soluble reactive phosphorus was significantly correlated with phosphatase activity in most wetlands, while the removal of total nitrogen, NO3(-) , and chemical oxygen demand (COD) was significantly correlated with enzyme activity only in a few instances. Correlations between soil enzyme activity and root activity varied among species. Activities of all enzymes were significantly correlated with root activity in Vetiveria zizanioides and Phragmites australis wetlands, but not in Hymenocallis littoralis wetlands. Significant correlations between enzyme activity and root biomass and between enzyme activity and root growth were found mainly in Cyperus flabelliformis wetlands. Root activity was significantly correlated with removal efficiencies of all contaminants except NO3(-) and COD in V. zizanioides wetlands. Enzyme activities and root activity showed single-peak seasonal patterns. Activities of phosphatase, urease, and cellulase were significantly higher in the top layer of the substrate than in the deeper layers, and there were generally no significant differences between the deeper layers (deeper than 15 cm). PMID:19497608

  2. X-ray photoelectron spectroscopy surface analysis of aluminum ion stress in barley roots. [Hordeum vulgare

    SciTech Connect

    Millard, M.M.; Foy, C.D.; Coradetti, C.A.; Reinsel, M.D. )

    1990-06-01

    X-ray photoelectron spectroscopy (XPS) has been used to analyze root surface changes when Dayton barley (Hordeum vulgare) (Al tolerant) and Kearney barley (Al sensitive) seedlings were grown in nutrient solution in the presence and absence of 37.0 micromolar Al. The electron spectra from root surfaces contained strong lines in order of decreasing intensity from organic forms of carbon, oxygen, and nitrogen and weak lines due to inorganic elements in the form of anions and cations on the surface. The surface composition of root tips from Kearney was C, 65.6%; 0, 26.8%; N, 4.4% and tips from Dayton was C, 72.7%; O, 23.6%; N, 1.9%, grown in the absence of aluminum. Electron lines characteristic of nitrate, potassium, chloride, phosphate were also present in the spectra from those roots. Dayton roots grown in the presence of 37.0 micromolar aluminum contained 2.1% aluminum while Kearney contained 1.3% aluminum. The ratio of aluminum to phosphate was close to 1.0. Dayton roots usually contained twice as much aluminum phosphate in the surface region as Kearney. Dayton may be less susceptible to Al toxic effects by accumulation of aluminum phosphate on the root surface which then acts as a barrier to the transport of aluminum into the interior of the roots.

  3. Atmospheric radiation model for water surfaces

    NASA Technical Reports Server (NTRS)

    Turner, R. E.; Gaskill, D. W.; Lierzer, J. R.

    1982-01-01

    An atmospheric correction model was extended to account for various atmospheric radiation components in remotely sensed data. Components such as the atmospheric path radiance which results from singly scattered sky radiation specularly reflected by the water surface are considered. A component which is referred to as the virtual Sun path radiance, i.e. the singly scattered path radiance which results from the solar radiation which is specularly reflected by the water surface is also considered. These atmospheric radiation components are coded into a computer program for the analysis of multispectral remote sensor data over the Great Lakes of the United States. The user must know certain parameters, such as the visibility or spectral optical thickness of the atmosphere and the geometry of the sensor with respect to the Sun and the target elements under investigation.

  4. Processing of polymer surfaces by laser radiation

    NASA Astrophysics Data System (ADS)

    Kreutz, E. W.; Frerichs, H.; Stricker, J.; Wesner, D. A.

    1995-11-01

    The processing of polymer surfaces by laser radiation is investigated as a function of laser parameters (fluence, mode of operation) and processing variables (repetition rate, pulse number). Polymers under investigation are polyamide, polymethylmethacrylate, polypropylene, polystyrene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, styrene-acrylonitrile copolymer, polybutadiene terephtalate, and polyoxymethylene, which are studied in air within different processing regimes such as modification of surface properties for subsequent metallization and removal of material for structuring of surface geometry. The metallization of polymers, which are pretreated by laser irradiation, wet chemical etching or plasma etching, is performed via electroplating and physical vapour deposition as a function of surface properties. The removal of polymers including non-thermal and thermal processes is done by direct processing techniques in the demagnification mode within one processing step. The diagnosis and the modelling of physical processes involved in tailoring the surface properties of polymers with laser radiation have to be implied to improve any application of these materials.

  5. Europa Surface Radiation Environment for Lander Assessment

    NASA Technical Reports Server (NTRS)

    Cooper, John F.; Sturner, Steven J.

    2006-01-01

    The Jovian magnetospheric particle environment at Europa's surface is critical to assessment of landed astrobiological experiments in three respects: (1) the landing site must be chosen for the best prospects for detectable organic or inorganic signs of Life, e.g. regions of freshly emergent flows from the subsurface; (2) lander systems must reach the surface through the Jovian magnetospheric environment and operate long enough on the surface to return useful data; (3) lander instrumentation must be capable of detecting signs of life in the context of the local environmental radiation and associated chemistry. The Galileo, Voyager, and Pioneer missions have provided a wealth of data on energetic particle intensities throughout the Jovian magnetosphere including from many flybys of Europa. cumulative radiation dosages for spacecraft enroute to Europa can be well characterized, but knowledge of the surface radiation environment is very limited. Energetic electrons should primarily impact the trailing hemisphere with decreasing intensity towards the center of the leading hemisphere and are the most significant radiation component down to meter depths in the surface regolith due to secondary interactions. Observed surface distribution for sulfates is suggestive of electron irradiation but may have alternative interpretations. Having much-larger magnetic gyroradii than electrons, energetic protons and heavier ions irradiate more of the global surface. The particular orientations of electron, proton, and ion gyromotion would project into corresponding directional (e.g., east-west) anisotropies of particle flu into the surface. Particular topographic features at the landing site may therefore offer shielding from part of the incident radiation.

  6. Effect of citric acid, tetracycline, and doxycycline on instrumented periodontally involved root surfaces: A SEM study

    PubMed Central

    Chahal, Gurparkash Singh; Chhina, Kamalpreet; Chhabra, Vipin; Bhatnagar, Rakhi; Chahal, Amna

    2014-01-01

    Background: A surface smear layer consisting of organic and inorganic material is formed on the root surface following mechanical instrumentation and may inhibit the formation of new connective tissue attachment to the root surface. Modification of the tooth surface by root conditioning has resulted in improved connective tissue attachment and has advanced the goal of reconstructive periodontal treatment. Aim: The aim of this study was to compare the effects of citric acid, tetracycline, and doxycycline on the instrumented periodontally involved root surfaces in vitro using a scanning electron microscope. Settings and Design: A total of 45 dentin samples obtained from 15 extracted, scaled, and root planed teeth were divided into three groups. Materials and Methods: The root conditioning agents were applied with cotton pellets using the Passive burnishing technique for 5 minutes. The samples were then examined by the scanning electron microscope. Statistical Analysis Used: The statistical analysis was carried out using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 15.0 for Windows). For all quantitative variables means and standard deviations were calculated and compared. For more than two groups ANOVA was applied. For multiple comparisons post hoc tests with Bonferroni correction was used. Results: Upon statistical analysis the root conditioning agents used in this study were found to be effective in removing the smear layer, uncovering and widening the dentin tubules and unmasking the dentin collagen matrix. Conclusion: Tetracycline HCl was found to be the best root conditioner among the three agents used. PMID:24744541

  7. Biological effects of a root conditioning agent for dentin surface modification in vitro

    PubMed Central

    Lee, Jue-Yeon; Seol, Yang-Jo; Park, Jang-Ryul; Park, Yoon-Jeong

    2010-01-01

    Purpose Connective tissue reattachment to periodontally damaged root surfaces is one of the most important goals of periodontal therapy. The aim of this study was to develop a root conditioning agent that can demineralize and detoxify the infected root surface. Methods Dentin slices obtained from human teeth were treated with a novel root planing agent for 2 minutes and then washed with phosphate-buffered saline. Smear layer removal and type I collagen exposure were observed by scanning electron microscopy (SEM) and type I collagen immunostaining, respectively. Cell attachment and lipopolysaccharides (LPS) removal demonstrated the efficiency of the root conditioning agent. Results SEM revealed that the smear layer was entirely removed and the dentinal tubules were opened by the experimental gel. Type I collagen was exposed on the surfaces of the dentin slices treated by the experimental gel, which were compared with dentin treated with other root planing agents. Dentin slices treated with the experimental gel showed the highest number of attached fibroblasts and flattened cell morphology. The agar diffusion assay demonstrated that the experimental gel also has effective antimicrobial activity. Escherichia coli LPS were effectively removed from well plates by the experimental gel. Conclusions These results demonstrated that this experimental gel is a useful tool for root conditioning of infected root surfaces and can also be applied for detoxification of ailing implant surface threads. PMID:21246015

  8. Ultraviolet Radiation on the Surface of Mars

    NASA Technical Reports Server (NTRS)

    Catling, D. C.; Cockell, C. S.; McKay, C. P.

    1999-01-01

    An evaluation of the ultraviolet (UV) flux incident on the Martian surface is important for a number of issues. UV-induced photolysis of water changes the chemistry of the soil and atmosphere, inducing its oxidizing nature. Alternatively, UV may directly affect surface chemistry by generating silicate defects. UV also rapidly degrades organic material delivered by meteoritic infall. Consequently, UV affects the overall chemistry of the Martian surface and atmosphere. The extent of UV breakdown of organic molecules is also relevant to concerns regarding contaminants on lander or rover surfaces that could interfere with life-detection experiments causing "false positives". The radiation flux at a point on the surface of Mars depends on factors such as cloud cover, atmospheric dust loading, season, local time, and latitude. Previously, the UV spectrum incident on the surface of Mars has been calculated from a simple radiative transfer model. Limitations of this earlier model include no accounting for the effect of dust, which may be a perennial constituent of the atmosphere, and also the use of gas absorption data measured at room temperature that overestimate absorption for lower Martian temperatures. We present an updated model for UV radiation (200-400 nm) that incorporates dust and more recent data for the solar spectrum, gas absorption, and UV surface albedo. Additional information is contained in the original extended abstract.

  9. Estimating root zone soil moisture using near-surface observations from SMOS

    NASA Astrophysics Data System (ADS)

    Ford, T. W.; Harris, E.; Quiring, S. M.

    2014-01-01

    Satellite-derived soil moisture provides more spatially and temporally extensive data than in situ observations. However, satellites can only measure water in the top few centimeters of the soil. Root zone soil moisture is more important, particularly in vegetated regions. Therefore estimates of root zone soil moisture must be inferred from near-surface soil moisture retrievals. The accuracy of this inference is contingent on the relationship between soil moisture in the near-surface and the soil moisture at greater depths. This study uses cross correlation analysis to quantify the association between near-surface and root zone soil moisture using in situ data from the United States Great Plains. Our analysis demonstrates that there is generally a strong relationship between near-surface (5-10 cm) and root zone (25-60 cm) soil moisture. An exponential decay filter is used to estimate root zone soil moisture using near-surface soil moisture derived from the Soil Moisture and Ocean Salinity (SMOS) satellite. Root zone soil moisture derived from SMOS surface retrievals is compared to in situ soil moisture observations in the United States Great Plains. The SMOS-based root zone soil moisture had a mean R2 of 0.57 and a mean Nash-Sutcliffe score of 0.61 based on 33 stations in Oklahoma. In Nebraska, the SMOS-based root zone soil moisture had a mean R2 of 0.24 and a mean Nash-Sutcliffe score of 0.22 based on 22 stations. Although the performance of the exponential filter method varies over space and time, we conclude that it is a useful approach for estimating root zone soil moisture from SMOS surface retrievals.

  10. The surface of root canal irradiated by Nd:YAG laser with TiO2

    NASA Astrophysics Data System (ADS)

    Ebihara, Arata; Anjo, Tomoo; Takeda, Atsushi; Suda, Hideaki

    2004-05-01

    The aim of this study was to determine the appropriateness of Nd:YAG laser irradiation for root canal preparation. Tooth crowns were removed from single-rooted human teeth and a quartz optical fiber (diameter 400 μm) was inserted into the root canal orifice towards the apical foramen. The length of the fiber within the root canal was measured, and the irradiating length determined. Root canals were then filled with 3% TiO2 emulsion solution (a photosensitizer) and irradiated using a pulsed Nd:YAG laser at 600 mJ/pulse (pulse frequency; 5 or 10 pps). During laser irradiation, the fiber was moved coronally from the apical region towards the canal orifice at a rate of 1 mm/s. Contact microradiographs (CMR) were taken before and after laser irradiation. Each root was then halved longitudinally, and the root canal surface observed by scanning electron microscopy (SEM). The CMR images of the tooth revealed that the root canal was slightly enlarged as a result of treatment. Carbonization of the root canal dentin was not seen, but a smear layer and melted dentin were observed by SEM. Nd:YAG laser irradiation using TiO2 emulsion solution appears to be a useful tool for root canal preparation.

  11. Er:YAG and alexandrite laser radiation propagation in the root canal and its effect on bacteria

    NASA Astrophysics Data System (ADS)

    Jelinkova, Helena; Dostalova, Tatjana; Duskova, Jana; Miyagi, Mitsunobu; Shoji, Shigeru; Sulc, Jan; Nemec, Michal

    1999-05-01

    The goal of the study was to verify differences between the alexandrite and Er:YAG laser energy distribution in the root canal and in the surrounding dentin and bone tissues. For the experiment, two lasers were prepared: the Er:YAG laser (λ=2.94 μm) with a delivery system fluorocarbon polymer-coated silver hollow glass waveguide ended by a special sapphire tip and the alexandrite laser (λ=0.75 μm) with a silicon fiber. The Er:YAG laser was operated in a free-running mode, the length of the generated pulses was 250 μsec and the output energy ranged from 100 to 350 mJ. The pulse length of the free- running alexandrite laser was 70 μsec and the output energy was ranged from 80 up to 200 mJ. For the experiment prepared root canals of molars were used. It was ascertained that the radiation of the alexandrite laser passes through the root canal and hits the surrounding tissue. Nocardia asteroids, Filaments, Micrococcus albus, Lactobacillus sp and Streptococcus sanguis colonies were treated by the Er:YAG or alexandrite laser radiation. The surface was checked by scanning electron microscopy. From the result it follows that the Er:YAG laser destroyed microbial colonies but the differences is in the depth of the affected area.

  12. Thermal and microstructural effects of nanosecond pulsed Nd:YAG laser irradiation on tooth root surface

    NASA Astrophysics Data System (ADS)

    Wilder-Smith, Petra B. B.; Arrastia-Jitosho, Anna-Marie A.; Grill, G.; Liaw, Lih-Huei L.; Berns, Michael W.

    1995-05-01

    Plaque, calculus and altered cementum removal by scaling and root planing is a fundamental procedure in periodontal treatment. However, the residual smear layer contains cytotoxic and inflammatory mediators which adversely affect healing. Chemical smear layer removal is also problematic. In previous investigations effective smear layer removal was achieved using long pulsed irradiation at 1.06 (mu) . However, laser irradiation was not adequate as an alternative to scaling and root planing procedures and concurrent temperature rises exceeded thermal thresholds for pulpal and periodontal safety. It was the aim of this study to determine whether nanosecond pulsed irradiation at 1.06 (mu) could be used as an alternative or an adjunct to scaling and root planing. Sixty freshly extracted teeth were divided as follows: 5 control, 5 root planed only, 25 irradiated only, 25 root planed and irradiated. Irradiation was performed at fluences of 0.5 - 2.7 J/cm2, total energy densities of 12 - 300 J/cm2, frequencies of 2 - 10 Hz using the Medlite (Continuum) laser. Irradiation-induced thermal events were recorded using a thermocouple within the root canal and a thermal camera to monitor surface temperatures. SEM demonstrated effective smear layer removal with minimal microstructural effects. Surface temperatures increased minimally (< 3 C) at all parameters, intrapulpal temperature rises remained below 4 C at 2 and 5 Hz, F < 0.5 J/cm2. Without prior scaling and root planing, laser effects did not provide an adequately clean root surface.

  13. Detection of Root Surface Fractures with Swept-Source Optical Coherence Tomography (SS-OCT)

    PubMed Central

    Yoshioka, Toshihiko; Sakaue, Hitoshi; Ishimura, Hitomi; Suda, Hideaki; Sumi, Yasunori

    2013-01-01

    Abstract Objective: The purpose of this study was to compare optical coherence tomography (OCT) with the existing technologies, to assess its accuracy and utility in detecting vertical root fractures of extracted human teeth. Background data: The detection of root fractures in teeth that have undergone root canal treatment is challenging because of the great difficulty in differentiating these fractures from morphologic or radiographic anomalies. OCT methods are based on depth-resolved optical reflectivity and have been developed to reduce the invasiveness and radiation exposure inherent to other techniques. Methods: Twelve extracted human mandibular teeth (totaling 25 roots) that were free of caries, calculus, and root treatment were used, and assessed by microfocus computed tomography, the current gold standard for fracture detection. The ability of appropriately trained observers to detect root fractures using visual, microscopic, and swept-source OCT (SS-OCT) techniques were compared. micro-CT and SS-OCT produce three-dimensional images of the tooth from which to diagnose fractures, but CT scanning involves radiation exposure that is not required in SS-OCT. Results: Seventeen of the 25 roots were found to have fractures by microfocus CT. These findings were replicated by SS-OCT, which revealed fractures exhibiting identical origin, size, and angulation within the root. We found that SS-OCT gave results compatible to the gold standard technique, and that SS-OCT and microscopy were more effective for identifying root fractures than was visual observation alone. Conclusions: SS-OCT may represent a novel, noninvasive, noncontact and nonexposure alternative to the conventional methods used for assessing root fractures in teeth. PMID:23240873

  14. Sorption of fibronectin to human root surfaces in vitro

    SciTech Connect

    Mendieta, C.; Caravana, C.; Fine, D.H. )

    1990-05-01

    The purpose of this study was to determine the conditions that favor the sorption and retention of human plasma fibronectin to cementum. Rectangular root segments prepared from teeth extracted for orthodontic reasons were mounted on a capillary pipette and immersed in solutions of {sup 125}I fibronectin for assay of cementum sorption under various conditions. Kinetic studies showed sorption to be rapid, with 77% of the maximum fibronectin sorption occurring within 1 minute. Fibronectin sorption was reduced when added in conjunction with serum and was inhibited by monovalent ions (such as sodium), but enhanced in the presence of divalent cations (such as calcium). Exposure of cementum to serum partially blocked subsequent sorption of fibronectin, while cementum bound fibronectin was eluted by subsequent exposure to serum. Treatment of cementum with citric acid pH 1.1 (4 minutes) followed by 5% sodium hypochlorite (5 minutes) caused a significant increase in fibronectin sorption with maximum retention upon subsequent exposure to serum (P less than 0.05). Fibronectin sorption to cementum was: rapid, electrostatic in nature, competitive, reversible, Ca+(+)-facilitated, and maximized by prior treatment of the root with citric acid and sodium hypochlorite. It is concluded that sorption of fibronectin to cementum can be achieved for clinical gain; however, conditions of application can significantly influence both accumulation and subsequent release of root sorbed material.

  15. Calculus removal on a root cement surface by ultrashort laser pulses

    NASA Astrophysics Data System (ADS)

    Kraft, Johan F.; Vestentoft, Kasper; Christensen, Bjarke H.; Løvschall, Henrik; Balling, Peter

    2008-01-01

    Ultrashort-pulse-laser ablation of dental calculus (tartar) and cement is performed on root surfaces. The investigation shows that the threshold fluence for ablation of calculus is a factor of two to three times smaller than that of a healthy root cement surface. This indicates that ultrashort laser pulses may provide an appropriate tool for selective removal of calculus with minimal damage to the underlying root cement. Future application of an in situ profiling technique allows convenient on-line monitoring of the ablation process.

  16. Space station thermal control surfaces. [space radiators

    NASA Technical Reports Server (NTRS)

    Maag, C. R.; Millard, J. M.; Jeffery, J. A.; Scott, R. R.

    1979-01-01

    Mission planning documents were used to analyze the radiator design and thermal control surface requirements for both space station and 25-kW power module, to analyze the missions, and to determine the thermal control technology needed to satisfy both sets of requirements. Parameters such as thermal control coating degradation, vehicle attitude, self eclipsing, variation in solar constant, albedo, and Earth emission are considered. Four computer programs were developed which provide a preliminary design and evaluation tool for active radiator systems in LEO and GEO. Two programs were developed as general programs for space station analysis. Both types of programs find the radiator-flow solution and evaluate external heat loads in the same way. Fortran listings are included.

  17. Remineralization of root surfaces demineralized in solutions of differing fluoride levels.

    PubMed

    Heilman, J R; Jordan, T H; Warwick, R; Wefel, J S

    1997-01-01

    The beneficial effects of fluoride on enamel have been well documented. However, limited data are available concerning the amount of fluoride required for beneficial effects on tooth root. Although studies have shown that fluoride inhibits root demineralization, the aim of this study was to investigate the location, extent and amount of remineralization on root dentin substrates after demineralization has occurred. The root surfaces of extracted human teeth were demineralized in a pure chemical buffer containing varying concentrations of sodium fluoride. After this lesion initiation, the same root sections were then placed into a remineralizing solution. The root sections were characterized after demineralization, and again after remineralization, by polarized light microscopy (PLM) and microradiography (MRG). Lesion depths after the demineralization phase were found to be inversely proportional to the fluoride concentration. When fluoride was present, bands or lines within the body of the lesion were observed with PLM and MRG. Using quantitative MRG, variations in mineral content and distribution were recorded. Examination of the root sections after the remineralization phase showed remineralization to have occurred on the remaining mineral and not on organic matrix devoid of mineral. The amount and location of mineral deposition may be of great significance in the arrestment and treatment of in vivo root surface caries. PMID:9353581

  18. Comparison of surface radiative flux parameterizations. Part II. Shortwave radiation

    NASA Astrophysics Data System (ADS)

    Niemelä, Sami; Räisänen, Petri; Savijärvi, Hannu

    This paper presents a comparison of several shortwave (SW) downwelling radiative flux parameterizations with hourly averaged pointwise surface radiation observations made at Jokioinen and Sodankylä, Finland, in 1997. Both clear and cloudy conditions are considered. The clear-sky comparisons included six simple SW parameterizations, which use screen level input data, and three radiation schemes from numerical weather prediction (NWP) models: the former European Centre for Medium-Range Weather Forecast (ECMWF) scheme, the Deutscher Wetterdienst (DWD) scheme, and the High Resolution Limited Area Model (HIRLAM) scheme. Atmospheric-sounding profiles were used as input for the NWP schemes. For the cases with clouds, three simple cloud correction methods (mainly dependent on the total cloud cover) were tested. In the SW clear-sky comparisons, the relatively simple scheme by Iqbal provided the best results, surprisingly outperforming even the NWP radiation models. Simple cloud corrections performed poorly in the SW region. Out of these schemes, a new cloud correction method developed using the present data provided the best results.

  19. Evaluation of Arctic broadband surface radiation measurements

    NASA Astrophysics Data System (ADS)

    Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Niebergall, O.; Wendell, J.; Albee, R.

    2012-02-01

    The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse) SW measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

  20. SEM Analysis of MTAD Efficacy for Smear Layer Removal from Periodontally Affected Root Surfaces

    PubMed Central

    Houshmand, B.; Ghandi, M.; Nekoofar, MH.; Gholamii, Gh. A.; Tabor, R. K.; Dummer, P. M. H.

    2011-01-01

    Objective Biopure® MTAD (Dentsply Tulsa Dental, USA) has been developed as a final irrigant following root canal shaping to remove intracanal smear layer. Many of the unique properties of MTAD potentially transfer to the conditioning process of tooth roots during periodontal therapy. The aim of this ex vivo study was to evaluate the effect of MTAD on the removal of smear layer from root surfaces. Materials and Methods Thirty two longitudinally sectioned specimens from 16 freshly extracted teeth diagnosed with advanced periodontal disease were divided into four groups. In group 1 and 2, the root surfaces were scaled using Gracey curettes. In group 3 and 4, 0.5 mm of the root surface was removed using a fissure bur. The specimens in group 1 and 3 were then irrigated by normal saline. The specimens in groups 2 and 4 were irrigated with Biopure MTAD. All specimens were prepared for SEM and scored according to the presence of smear layer. Results MTAD significantly increased (P=0.001) the smear layer removal in both groups 2 and 4 compared to the associated control groups, in which only saline was used. Conclusion MTAD increased the removal of the smear layer from periodontally affected root surfaces. Use of MTAD as a periodontal conditioner may be suggested. PMID:22509454

  1. Scanning electron microscopic analysis of the effect of Carisolv gel on periodontally compromised human root surfaces.

    PubMed

    Grisi, Daniela Corrêa; Theodoro, Letícia Helena; Sampaio, José Eduardo César; Grisi, Márcio Fernando de Moraes; Salvador, Sérgio Luiz de Souza

    2006-01-01

    The aim of this study was to analyze, under scanning electron microscopy (SEM), the morphologic characteristics of root surfaces after application of Carisolv gel in association with scaling and root planing (SRP). Sixty periodontally compromised extracted human teeth were randomly assigned to 6 groups: 1) SRP alone; 2) passive topical application of Carisolv + SRP; 3) active topical application of Carisolv + SRP; 4) multiple applications of Carisolv + SRP; 5) SRP + 24% EDTA; 6) topical application of Carisolv + SRP + 24% EDTA. Carisolv gel was applied to root surfaces for 30 s, followed by scaling and root planing, consisting of 50 strokes with Gracey curettes in an apical-coronal direction, parallel to the long axis of the tooth. The only exception was group 4, in which the roots were instrumented until a smooth, hard and glass-like surface was achieved. All specimens were further analyzed by SEM. The results showed that the treatment with Carisolv caused significant changes in root surface morphology of periodontally compromised teeth only when the chemical agent was actively applied (burnishing technique). Carisolv failed to remove the smear layer completely, especially with a single application, independently of the method of application. Multiple applications of Carisolv were necessary to achieve a smear layer reduction comparable to that obtained with 24% EDTA conditioning. PMID:16924336

  2. Deposition of corrosion products from dowels on human dental root surfaces measured with proton microprobe technique

    NASA Astrophysics Data System (ADS)

    Brune, D.; Brunell, G.; Lindh, U.

    1982-06-01

    Distribution of copper, mercury and zinc on human teeth root surfaces adjacent to dowels of gold alloy or brass as well as dowels of brass in conjunction with an amalgam crown has been measured with a proton microprobe using PIXE techniques. Upper limits of the contents of gold and silver on the root surfaces were established. Pronounced concentration profiles of copper and zinc were observed on the root surfaces of teeth prepared with dowels of brass. The dowel of gold alloy revealed only zinc deposition. The major part of copper on the root surfaces is assumed to arise from corrosion of the dowels, and has been transported to the surface by diffusion through the dential tubuli. Zinc in the volume analysed is a constituent of dentin tissue as well as a corrosion product of the brass dowel. Part of the zinc level could also be ascribed to erosion of the zinc phosphate cement matrix. The volumes analysed were (25×25×25)μm 3. The levels of copper, mercury and zinc on the tooth root surfaces attained values up to about 200, 20 and 600 ppm, respectively.

  3. Effects of nature of cooling surface on radiator performance

    NASA Technical Reports Server (NTRS)

    Parsons, S R; Kleinschmidt, R V

    1921-01-01

    This report discusses the effects of roughness, smoothness, and cleanness of cooling surfaces on the performance of aeronautic radiators, as shown by experimental work, with different conditions of surface, on (1) heat transfer from a single brass tube and from a radiator; (2) pressure drop in an air stream in a single brass tube and in a radiator; (3) head resistance of a radiator; and (4) flow of air through a radiator. It is shown that while smooth surfaces are better than rough, the surfaces usually found in commercial radiators do not differ enough to show marked effect on performance, provided the surfaces are kept clean.

  4. Healing of the root surface-associated periodontium: an immunohistochemical study of orthodontic root resorption in man.

    PubMed

    Sismanidou, C; Hilliges, M; Lindskog, S

    1996-10-01

    The purpose of the present investigation was to study resorption and regeneration of periodontal tissues incident to orthodontic tooth movement, in particular cells resorbing the root surface and the subsequent regeneration of the periodontal epithelial network and forming reparative cementum. The study was carried out using a select number of immunohistochemical markers on extracted human teeth which had been treated orthodontically. The most striking finding in the resorbing areas was the presence of what appeared to be two populations of KP 1+ mononuclear cells located at a distance of 50-100 microns from the root surface and multinucleated cells in resorption lacunae in close contact with the root surface. KP 1+ has previously not been reported for odontoclasts. The mononuclear KP 1+ cells in the periodontal ligament may represent either precursors to odontoclasts or phagocytic scavenger cells of the macrophage lineage. The subsequent healing of the resorption lacunae was characterized by re-establishment of nervous, vascular and epithelial tissues as evidenced by S-100+ filamentous delicate structures, factor VIII+ vessels and cytokeratin+ clusters of cells, respectively. However, cytokeratin+ single cells in close contact with the unresorbed cementum did not re-appear within the healing period. Although the present results are not quantitative in nature, cementoblasts located in the vicinity of resorption lacunae, especially healing ones, appeared to show an up-regulation of epidermal growth factor (EGF) receptors. It may be suggested the intense positive staining for EGF receptors may be an expression of an auto- or paracrine stimulatory pathway increasing the rate of reparative cementum formation. PMID:8942091

  5. Annual Cycles of Surface Shortwave Radiative Fluxes

    NASA Technical Reports Server (NTRS)

    Wilber, Anne C.; Smith, G. Louis; Gupta, Shashi K.; Stackhouse, Paul W.

    2006-01-01

    The annual cycles of surface shortwave flux are investigated using the 8-yr dataset of the surface radiation budget (SRB) components for the period July 1983-June 1991. These components include the downward, upward, and net shortwave radiant fluxes at the earth's surface. The seasonal cycles are quantified in terms of principal components that describe the temporal variations and empirical orthogonal functions (EOFs) that describe the spatial patterns. The major part of the variation is simply due to the variation of the insolation at the top of the atmosphere, especially for the first term, which describes 92.4% of the variance for the downward shortwave flux. However, for the second term, which describes 4.1% of the variance, the effect of clouds is quite important and the effect of clouds dominates the third term, which describes 2.4% of the variance. To a large degree the second and third terms are due to the response of clouds to the annual cycle of solar forcing. For net shortwave flux at the surface, similar variances are described by each term. The regional values of the EOFs are related to climate classes, thereby defining the range of annual cycles of shortwave radiation for each climate class.

  6. Surface daytime net radiation estimation using artificial neural networks

    DOE PAGESBeta

    Jiang, Bo; Zhang, Yi; Liang, Shunlin; Zhang, Xiaotong; Xiao, Zhiqiang

    2014-11-11

    Net all-wave surface radiation (Rn) is one of the most important fundamental parameters in various applications. However, conventional Rn measurements are difficult to collect because of the high cost and ongoing maintenance of recording instruments. Therefore, various empirical Rn estimation models have been developed. This study presents the results of two artificial neural network (ANN) models (general regression neural networks (GRNN) and Neuroet) to estimate Rn globally from multi-source data, including remotely sensed products, surface measurements, and meteorological reanalysis products. Rn estimates provided by the two ANNs were tested against in-situ radiation measurements obtained from 251 global sites between 1991–2010more » both in global mode (all data were used to fit the models) and in conditional mode (the data were divided into four subsets and the models were fitted separately). Based on the results obtained from extensive experiments, it has been proved that the two ANNs were superior to linear-based empirical models in both global and conditional modes and that the GRNN performed better and was more stable than Neuroet. The GRNN estimates had a determination coefficient (R2) of 0.92, a root mean square error (RMSE) of 34.27 W·m–2 , and a bias of –0.61 W·m–2 in global mode based on the validation dataset. In conclusion, ANN methods are a potentially powerful tool for global Rn estimation.« less

  7. Thermal measurement of root surface temperatures during application of intracanal laser energy in vitro

    NASA Astrophysics Data System (ADS)

    Goodis, Harold E.; White, Joel M.; Neev, Joseph

    1993-07-01

    The use of laser energy to clean, shape, and sterilize a root canal system space involves the generation of heat due to the thermal effect of the laser on the organic tissue contents and dentin walls of that space. If heat generation is above physiologic levels, irreparable damage may occur to the periodontal ligament and surrounding bone. This study measured temperature rise on the outer root surfaces of extracted teeth during intracanal laser exposure. Thirty single rooted, recently extracted teeth free of caries and restorations were accessed pulps extirpated and divided into three groups. Each root canal system was treated with a 1.06 micrometers pulsed Nd:YAG laser with quartz contact probes. Temperatures were recorded for all surfaces (mesial distal, buccal, lingual, apical) with infrared thermography utilizing a detector response time of 1 (mu) sec, sensitivity range (infrared) of 8 to 12 micrometers and a scan rate of 30 frames/sec.

  8. Annual Cycle of Surface Longwave Radiation

    NASA Technical Reports Server (NTRS)

    Mlynczak, Pamela E.; Smith, G. Louis; Wilber, Anne C.; Stackhouse, Paul W.

    2011-01-01

    The annual cycles of upward and downward longwave fluxes at the Earth s surface are investigated by use of the NASA/GEWEX Surface Radiation Budget Data Set. Because of the immense difference between the heat capacity of land and ocean, the surface of Earth is partitioned into these two categories. Principal component analysis is used to quantify the annual cycles. Over land, the first principal component describes over 95% of the variance of the annual cycle of the upward and downward longwave fluxes. Over ocean the first term describes more than 87% of these annual cycles. Empirical orthogonal functions show the corresponding geographical distributions of these cycles. Phase plane diagrams of the annual cycles of upward longwave fluxes as a function of net shortwave flux show the thermal inertia of land and ocean.

  9. Biophysical characterization and surface radiation balance

    NASA Technical Reports Server (NTRS)

    Walter-Shea, Elizabeth A.; Blad, Blaine L.; Mesarch, Mark A.; Hays, Cynthia J.; Starks, Patrick J.

    1993-01-01

    The Kursk 1991 Experiment (KUREX-91) was conducted as one of a suite of international studies to develop capabilities to monitor global change. The studies were designed specifically to understand the earth's land-surface vegetation and atmospheric boundary layer interaction. An intensive field campaign was conducted at a site near Kursk, Russia during the month of July in 1991 by a team of international scientists to aid in the understanding of land-surface-atmosphere interactions in an agricultural/grassland setting. We were one of several teams of scientists participating at KUREX-91 at the Streletskaya Steppe Researve near Kursk, Russia. The main goals of our research were to: (1) characterize biophysical properties of the prairie vegetation; and (2) to characterize radiation regime through measurements and from estimates derived from canopy bidirectional reflectance data. Four objectives were defined to achieve these goals: (1) determine dependence of leaf optical properties on leaf water potential of some dominant species in discrete wavebands in the visible, near-infrared, and mid-infrared (spanning 0.4-2.3 microns range); (2) characterize the effective leaf area index (LAI) and leaf angle distribution of prairie vegetation; (3) characterize the radiation regime of the prairie vegetation through measures of the radiation balance components; and (4) examine, develop, and test methods for estimating albedo, APAR, and LAI from canopy bidirectional reflectance data. Papers which were the result of the research efforts are included.

  10. Isolation of a novel mutant gene for soil-surface rooting in rice (Oryza sativa L.)

    PubMed Central

    2013-01-01

    Background Root system architecture is an important trait affecting the uptake of nutrients and water by crops. Shallower root systems preferentially take up nutrients from the topsoil and help avoid unfavorable environments in deeper soil layers. We have found a soil-surface rooting mutant from an M2 population that was regenerated from seed calli of a japonica rice cultivar, Nipponbare. In this study, we examined the genetic and physiological characteristics of this mutant. Results The primary roots of the mutant showed no gravitropic response from the seedling stage on, whereas the gravitropic response of the shoots was normal. Segregation analyses by using an F2 population derived from a cross between the soil-surface rooting mutant and wild-type Nipponbare indicated that the trait was controlled by a single recessive gene, designated as sor1. Fine mapping by using an F2 population derived from a cross between the mutant and an indica rice cultivar, Kasalath, revealed that sor1 was located within a 136-kb region between the simple sequence repeat markers RM16254 and 2935-6 on the terminal region of the short arm of chromosome 4, where 13 putative open reading frames (ORFs) were found. We sequenced these ORFs and detected a 33-bp deletion in one of them, Os04g0101800. Transgenic plants of the mutant transformed with the genomic fragment carrying the Os04g0101800 sequence from Nipponbare showed normal gravitropic responses and no soil-surface rooting. Conclusion These results suggest that sor1, a rice mutant causing soil-surface rooting and altered root gravitropic response, is allelic to Os04g0101800, and that a 33-bp deletion in the coding region of this gene causes the mutant phenotypes. PMID:24280269

  11. Comparison of Root Surface Roughness Produced By Hand Instruments and Ultrasonic Scalers: An Invitro Study

    PubMed Central

    Das, Swarga Jyoti; Sonowal, Saindhya Tora; Chawla, Jitendra

    2015-01-01

    Background Instrumentation on tooth surface for debridement of hard and soft debris forms the basis of periodontal therapy. This involves periodic removal of accumulated material using different methods of instrumentation. An ideal instrument should eliminate all the deposits from the root surfaces with no or minimal alteration of the natural morphology. Aim To compare the root surface roughness after root planing performed with gracey curette and by ultrasonic scalers (Satelec P-5 Booster) set at different power modes. Materials and Methods The root surface roughness and its surface microtopography resulting from the use of Gracey curette, ultrasonic instrument at low, medium and high power setting on 35 healthy premolars extracted for orthodontic treatment purpose were examined using Optical Profilometer and the surface topography was assessed using Field Emission Microscope. Statistical Analysis Analysis of variance (ANOVA) test was used to observe the variance in a particular variable is partitioned into components attributable to different sources of variation. Duncan multiple range tests were used to determine whether three or more means differ significantly. Results and Conclusion The mean roughness was found to be the highest in group where Scaling and Root Planing (SRP) was performed using ultrasonic scaler at low power mode (3.03±1.54 μm) whereas the lowest surface roughness was seen on the samples where SRP was performed using ultrasonic scaler at medium power mode. The surface roughness in group where SRP was performed with ultrasonic scaler at high power mode (2.22±0.74μm) was found to be similar to that of group in which root planing was carried out using curette (2.24±1.71μm). PMID:26675445

  12. Regional Climatology and Surface Radiation Budget

    NASA Technical Reports Server (NTRS)

    Wilber, Anne C.; Smith, G. Louis; Stackhouse, Paul W., Jr.

    1999-01-01

    The climatology and surface radiation budget (SRB) of a region are intimately related. This paper presents a brief examination of this relationship. An 8-year surface radiation budget data set has been developed based on satellite measurements. In that data set and in this paper a region is defined as a quasi-square 2.5o in latitude and approximately the same physical distance in longitude. A pilot study by Wilber et al. (1998) showed a variety of behaviors of the annual cycles for selected regions. Selected desert regions form a loop in a specific part of the plot, with large NLW and large NSW. Tropical wet regions form much smaller loops in a different part of the plot, with small NLW and large NSW. For regions selected in high latitude the annual cycles form nearly linear figures in another part of the plot. The question arises as to whether these trajectories are characteristic of the climatology of the region or simply the behavior of the few regions selected from the set of 6596 regions. In order to address this question, it is necessary to classify the climatology of the each region, e.g. as classified by Koeppen (1936) or Trenwarthe and Horne (1980). This paper presents a method of classifying climate of the regions on the basis of the surface radiation behavior such that the results are very similar to the classification of Trenwarthe and Horne. The characteristics of the annual cycle of SRB components can then be investigated further, based on the climate classification of each region.

  13. Can the KTP laser change the cementum surface of healthy and diseased teeth providing an acceptable root surface for fibroblast attachment?

    NASA Astrophysics Data System (ADS)

    Mailhot, Jason M.; Garnick, Jerry J.

    1996-04-01

    The purpose of our research is to determine the effects of KTP laser on root cementum and fibroblast attachment. Initial work has been completed in testing the effect of different energy levels on root surfaces. From these studies optimal energy levels were determined. In subsequent studies the working distance and exposure time required to obtain significant fibroblast attachment to healthy cementum surfaces were investigated. Results showed that lased cemental surfaces exhibited changes in surface topography which ranged from a melted surface to an apparent slight fusion of the surface of the covering smear layer. When the optimal energy level was used, fibroblasts demonstrate attachment on the specimens, resulting in the presence of a monolayer of cells on the control surfaces as well as on the surfaces lased with this energy level. The present study investigates the treatment of pathological root surfaces and calculus with a KTP laser utilizing these optimal parameters determine previously. Thirty single rooted teeth with advanced periodontal disease and ten healthy teeth were obtained, crowns were sectioned and roots split longitudinally. Forty test specimens were assigned into 1 of 4 groups; pathologic root--not lased, pathologic root--lased, root planed root and health root planed root. Human gingival fibroblasts were seeded on specimens and cultured for 24 hours. Specimens were processed for SEM. The findings suggest that with the KTP laser using a predetermined energy level applied to pathological root surfaces, the lased surfaces provided an unacceptable surface for fibroblast attachment. However, the procedural control using healthy root planed surfaces did demonstrate fibroblast attachment.

  14. Validation and Spatiotemporal Analysis of CERES Surface Net Radiation Product

    DOE PAGESBeta

    Jia, Aolin; Jiang, Bo; Liang, Shunlin; Zhang, Xiaotong; Ma, Han

    2016-01-23

    The Clouds and the Earth’s Radiant Energy System (CERES) generates one of the few global satellite radiation products. The CERES ARM Validation Experiment (CAVE) has been providing long-term in situ observations for the validation of the CERES products. However, the number of these sites is low and their distribution is globally sparse, and particularly the surface net radiation product has not been rigorously validated yet. Therefore, additional validation efforts are highly required to determine the accuracy of the CERES radiation products. In this study, global land surface measurements were comprehensively collected for use in the validation of the CERES netmore » radiation (Rn) product on a daily (340 sites) and a monthly (260 sites) basis, respectively. The validation results demonstrated that the CERES Rn product was, overall, highly accurate. The daily validations had a Mean Bias Error (MBE) of 3.43 W·m−2, Root Mean Square Error (RMSE) of 33.56 W·m−2, and R2 of 0.79, and the monthly validations had an MBE of 3.40 W·m−2, RMSE of 25.57 W·m−2, and R2 of 0.84. The accuracy was slightly lower for the high latitudes. Following the validation, the monthly CERES Rn product, from March 2000 to July 2014, was used for a further analysis. We analysed the global spatiotemporal variation of the Rn, which occurred during the measurement period. In addition, two hot spot regions, the southern Great Plains and south-central Africa, were then selected for use in determining the driving factors or attribution of the Rn variation. We determined that Rn over the southern Great Plains decreased by −0.33 W·m−2 per year, which was mainly driven by changes in surface green vegetation and precipitation. In south-central Africa, Rn decreased at a rate of −0.63 W·m−2 per year, the major driving factor of which was surface green vegetation.« less

  15. Status of the Space Radiation Monte Carlos Simulation Based on FLUKA and ROOT

    NASA Technical Reports Server (NTRS)

    Andersen, Victor; Carminati, Federico; Empl, Anton; Ferrari, Alfredo; Pinsky, Lawrence; Sala, Paola; Wilson, Thomas L.

    2002-01-01

    The NASA-funded project reported on at the first IWSSRR in Arona to develop a Monte-Carlo simulation program for use in simulating the space radiation environment based on the FLUKA and ROOT codes is well into its second year of development, and considerable progress has been made. The general tasks required to achieve the final goals include the addition of heavy-ion interactions into the FLUKA code and the provision of a ROOT-based interface to FLUKA. The most significant progress to date includes the incorporation of the DPMJET event generator code within FLUKA to handle heavy-ion interactions for incident projectile energies greater than 3GeV/A. The ongoing effort intends to extend the treatment of these interactions down to 10 MeV, and at present two alternative approaches are being explored. The ROOT interface is being pursued in conjunction with the CERN LHC ALICE software team through an adaptation of their existing AliROOT software. As a check on the validity of the code, a simulation of the recent data taken by the ATIC experiment is underway.

  16. Root surface acid phosphatases and their role in phosphorus assimilation by Eriophorum vaginatum

    SciTech Connect

    Kroehler, C.J.; Linkins, A.E.

    1988-01-01

    Eriophorum vaginatum is a dominant plant in much of the arctic tundra ecosystem where phosphorus is frequently a limiting nutrient. The mineralization of this organic phosphorus was thought to be principally controlled by microbial respiration, however, more recent work shows that extracellular soil phosphatases are the principal regulators. The existence of plant root and mycorrhizal surface phosphatases which are capable of hydrolyzing organic phosphorus compounds, suggests that soil organic phosphorus may be directly utilized by plants. Since E. vaginatum is a tussock forming sedge with a very dense annually produced rooting system which can exploit most of the tussock soil volume, its surface phosphatases may play a dominant role in organic phosphorus hydrolysis into inorganic phosphorus. Of equal significance would be the potential for this activity to contribute to the phosphorus nutrition through the coupling of phosphorus hydrolysis on the root and root uptake of the resultant inorganic phosphorus. Phosphatase activity was investigated and found to be uniformly distributed along the surface of the root. Kinetic analysis of the enzyme gave estimates of 9.23 mM for the apparent Km and 1.61 * 10/sup -3/ ..mu..moles mm-2 hr/sup -1/ for the apparent Vmax. Saturation values for E. vaginatum phosphatases are about 3 times higher than average soil solution organic phosphorus concentrations. 12 refs., 4 figs.

  17. Holmium:YAG laser: effect on pulpal tissues and root surfaces

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1996-04-01

    The effects of the Holmium:YAG irradiation on the pulpal tissues and surface topography on root surface dentin in human teeth in vivo were studied. The exposed root surfaces of seventeen pre-immediate denture patients were scaled and root planed with a Gracey 3 - 4 curette apical to the dentinoenamel junction until smooth and hard. The prepared root surfaces of two teeth per patient were exposed with Holmium:YAG laser energy after an application of nonfilled resin/fluoride mixture. The laser exposed areas were below the dentinoenamel junction around one-half of each root surface. The opposing sides of each of the teeth received resin/fluoride but no laser energy. A third tooth was identified as a nontreated control. The HO:YAG at 2.12 microns wavelength with a defocused beam size of 3 mm was used. The amount of laser energy delivered per 3 X 5 mm area was 0.450 (+/- .05) joules with a fluence of 2.66 - 3.30 J/cm2. The teeth were extracted after periods of 45 - 120 days. The specimens were fixed in formalin and prepared for histological examination using hematoxylin and eosin stains. Microscopic evaluation of room surfaces showed increased smoothness on the laser treated sites compared to their opposing non-lased sides. Histological examination of the pulpal tissues exhibited no abnormal changes. No clinical symptoms of pulpal pathology were produced. HO:YAG laser energy proved safe for treating room surfaces of human teeth in vivo under conditions presented in this study.

  18. Parametrization of net radiation at the surface using data from the Wangara experiment

    SciTech Connect

    Edson, R T

    1980-07-01

    Hourly Wangara boundary layer data (Clark et al., 1971) was used to substantiate previously derived empirical equations of the surface radiation budget. These equations only require measurements taken by a surface observer in order to be evaluated. A parameterization was made for infrared (IR) radiation. From this procedure, a residual radiation was obtained from the measured daytime net radiation data in order to approximate short wave (SW) radiation. Diurnal trends in radiation and other related meteorological parameters were also evaluated. For IR radiation, the Brunt equation was found to adequately represent effective radiation without clouds. IR attenuation (K-values) of 0.89, 0.64, and 0.51 were calculated for low, middle, and high clouds, respectively. A modification of Beer's Law was derived to evaluate the residual radiation under clear skies as suggested by Flowers et al. (1969) for SW radiation. With the surface albedo assumed at 0.15, a mean turbidity coefficient of 0.16 was determined. Also, the square root of the optical air mass was found to best represent the data in this equation. An analysis of SW cloud attenuation coefficients (C-values) from the residual radiation proved inconclusive. Of considerable importance is the finding that cloud attenuation of the residual radiation behaved nonlinearly. Whereas solutions as high as the fourth order fit the data at noon, quadratic solutions fit well near sunset and sunrise. Overall; relative deviations during the day of the combined parameterization were approximately 20% at noon and just less than 30% for periods up to one hour before sunset or sunrise. Predictions within these one-hour periods, however, contained considerable error, partially due, to the scatter and small magnitude of the measurements. Diurnal trends in surface radiation and other meteorological parameters were established.

  19. Effect of phosphorus levels on the protein profiles of secreted protein and root surface protein of rice.

    PubMed

    Shinano, Takuro; Yoshimura, Tomoko; Watanabe, Toshihiro; Unno, Yusuke; Osaki, Mitsuru; Nanjo, Yohei; Komatsu, Setsuko

    2013-11-01

    Plant roots are complicated organs that absorb water and nutrients from the soil. Roots also play an essential role in protecting plants from attack by soil pathogens and develop a beneficial role with some soil microorganisms. Plant-derived rhizosphere proteins (e.g., root secretory proteins and root surface binding proteins) are considered to play important roles in developing mutual relationships in the rhizosphere. In the rhizosphere, where plant roots meet the surrounding environment, it has been suggested that root secretory protein and root surface binding protein are important factors. Furthermore, it is not known how the physiological status of the plant affects the profile of these proteins. In this study, rice plants were grown aseptically, with or without phosphorus nutrition, and proteins were obtained from root bathing solution (designated as root secretory proteins) and obtained using 0.2 M CaCl2 solution (designated as root surface binding proteins). The total number of identified proteins in the root bathing solution was 458, and the number of root surface binding proteins was 256. More than half of the proteins were observed in both fractions. Most of the proteins were categorized as either having signal peptides or no membrane transport helix sites. The functional categorization suggested that most of the proteins seemed to have secretory pathways and were involved in defense/disease-related functions. These characteristics seem to be unique to rhizosphere proteins, and the latter might be part of the plants strategy to defeat pathogens in the soil. The low phosphorus treatment significantly increased the number of pathogenesis-related proteins in the root secretory proteins, whereas the change was small in the case of the root surface binding proteins. The results suggested that the roots are actively and selectively secreting protein into the rhizosphere. PMID:24083427

  20. Radiation guiding with surface plasmon polaritons

    NASA Astrophysics Data System (ADS)

    Han, Zhanghua; Bozhevolnyi, Sergey I.

    2013-01-01

    Surface plasmon polaritons (SPPs) are electromagnetic (EM) modes propagating along metal-dielectric interfaces, in which surface collective excitations of free electrons in the metal are coupled to evanescent EM fields in the dielectric. Various SPP modes can be supported by flat and curved, single and multiple surfaces, exhibiting remarkable properties, including the possibility of concentrating EM fields beyond the diffraction limit, i.e. on the nanoscale, while enhancing local field strengths by several orders of magnitude. This unique feature of SPP modes, along with the ever-increasing demands for miniaturization of photonic components and circuits, generates an exponentially growing interest in SPP-mediated radiation guiding and SPP-based waveguide components. Here we review the current status of this rapidly developing field, starting with a brief presentation of the main planar SPP modes along with the techniques employed for their excitation and manipulation by sets of nanoparticles. We then describe in detail various SPP-based waveguide configurations that ensure two-dimensional mode confinement in the plane perpendicular to the propagation direction and compare their characteristics. Excitation of SPP waveguide modes and recent progress in the development of SPP-based waveguide components are also discussed, concluding with our outlook on challenges and possible future developments in this field.

  1. Toward Improved Solar Irradiance Forecasts: Derivation of Downwelling Surface Shortwave Radiation in Arizona from Satellite

    NASA Astrophysics Data System (ADS)

    Kim, Chang Ki; Holmgren, William F.; Stovern, Michael; Betterton, Eric A.

    2016-05-01

    Over the past few decades, substantial progress has been made in the retrieval of surface shortwave radiation from satellite measurements for the Earth's energy budget as well as solar energy applications. We present a new algorithm to derive the downwelling surface shortwave radiation for the Southwestern US using geostationary satellite products. A look-up table generated by the Goddard Space Flight Center Radiative Transfer Model is employed to derive the shortwave radiation at the ground by comparing observed and modeled top of atmosphere shortwave albedo. The algorithm was compared to ground observation stations at three locations, such as the University of Arizona, the University of Nevada, Las Vegas, and Desert Rock, NV. For all sky conditions, the average values of root-mean-square error between the instantaneous estimates and in situ measurements ranged from 84.2 to 89.4 W m-2 and were 30 W m-2 when evaluated on daily time scales. The error statistics were considerably better for clear sky than for cloudy sky. The average values of instantaneous root-mean-square error for the clear-sky conditions range from 39.4 to 43.7 W m-2, while average root-mean-square error for the cloudy-sky conditions is between 137.0 and 141.2 W m-2.

  2. Toward Improved Solar Irradiance Forecasts: Derivation of Downwelling Surface Shortwave Radiation in Arizona from Satellite

    NASA Astrophysics Data System (ADS)

    Kim, Chang Ki; Holmgren, William F.; Stovern, Michael; Betterton, Eric A.

    2016-07-01

    Over the past few decades, substantial progress has been made in the retrieval of surface shortwave radiation from satellite measurements for the Earth's energy budget as well as solar energy applications. We present a new algorithm to derive the downwelling surface shortwave radiation for the Southwestern US using geostationary satellite products. A look-up table generated by the Goddard Space Flight Center Radiative Transfer Model is employed to derive the shortwave radiation at the ground by comparing observed and modeled top of atmosphere shortwave albedo. The algorithm was compared to ground observation stations at three locations, such as the University of Arizona, the University of Nevada, Las Vegas, and Desert Rock, NV. For all sky conditions, the average values of root-mean-square error between the instantaneous estimates and in situ measurements ranged from 84.2 to 89.4 W m-2 and were 30 W m-2 when evaluated on daily time scales. The error statistics were considerably better for clear sky than for cloudy sky. The average values of instantaneous root-mean-square error for the clear-sky conditions range from 39.4 to 43.7 W m-2, while average root-mean-square error for the cloudy-sky conditions is between 137.0 and 141.2 W m-2.

  3. Lunar surface fission power supplies: Radiation issues

    SciTech Connect

    Houts, M.G.; Lee, S.K.

    1994-07-01

    A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to these seen in free space. For a well designed shield, the additional mass required to be brought fro earth should be less than 1000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield.

  4. The roots of coronal structure in the Sun's surface

    NASA Technical Reports Server (NTRS)

    Golub, Leon; Zirin, Harold; Wang, Haimin

    1994-01-01

    We have compared the structures seen on X-ray images obtained by a flight of the NIXT sounding rocket payload on July 11, 1991 with near-simultaneous photospheric and chromospheric structures and magnetic fields observed at Big Bear. The X-ray images reflect emission of both Mg X and Fe XVI, formed at 1 x 10(exp 6) K and 3 x 10(exp 6) K, respectively. The brightest H(alpha) sources correspond to a dying sub-flare and other active region components, all of which reveal coronal enhancements situated spatially well above the H(alpha) emission. The arches appear to lie in a small range of angle in the meridian plane connecting their footpoints. Sunspots are dark on the surface and in the corona. For the first time we see an emerging flux region in X-rays and find the emission extends twice as high as the H(alpha) arches. Many features which we believe to correspond to `X-ray bright points' (XBPs) were observed. Whether by resolution or spectral band, the number detected greatly exceeds that from previous work. All of the brighter XBPs correspond to bipolar H(alpha) features, while unipolar H(alpha) bright points are the base of more diffuse comet-like coronal arches, generally vertical. These diverge from individual features by less than 30 deg, and give a good measure of what the `canopies' must do. The H(alpha) data shows that all the H(alpha) features were present present the entire day, so they are not clearly disappearing or reappearing. We find a new class of XBPs which we call `satellite points', elements of opposite polarity linked to nearby umbrae by invisible field lines. The satellite points change rapidly in X-ray brightness during the flight. An M1.9 flare occurred four hours after the flight; examination of the pre-flare structures reveals nothing unusual.

  5. Influence of low-intensity laser radiation upon the microflora of carious cavities and root canal

    NASA Astrophysics Data System (ADS)

    Shumilovitch, Bogdan R.; Nekrylov, Valery; Mazo, Leonid

    1995-04-01

    Laser stomatology- a relatively young branch of stomatology -has been developing actively lately. Bactericidal action of laser radiation enables to use it widely for processing carious cavities and root canals in the treatment of caries and its complications. 113 patients were studied by us. The 40 patients had antiseptic procedure of the caries cavity and then the procedure of laser therapy, so micro-organisms were found out in 26% cases. The 63 patients had antiseptic procedure only, so micro-organisms were found out in 70% cases. Control group were consisted of patients, where laser therapy was carried out without antiseptic remedies.

  6. Surface Soil Moisture Assimilation From ASAR Imagery for Root Zone Moisture Predictions at Basin Scale

    NASA Astrophysics Data System (ADS)

    Caschili, A.; Montaldo, N.; Mancini, M.; Albertson, J. D.; Botti, P.; Dessena, M. A.; Carboni, E.

    2003-12-01

    The state of the root-zone soil moisture is a key variable controlling surface water and energy balances. Emerging efforts in data assimilation seek to guide land surface models (LSMs) with periodic observations of surface soil moisture. Montaldo et al. (Water Resour. Res., 2001) and Montaldo and Albertson (Adv. Water Resour., 2003) developed an operational multi-scale assimilation system for robust root zone soil moisture predictions at the local scale. The assimilation scheme, developed for a force-restore method based LSM, updates the measured surface soil moisture, the root zone soil water content and the soil hydraulic conductivity, in a manner that compensates for both inaccurate initial conditions and model parameter estimates. In this presentation we describe the development and testing of an operational assimilation system for robust root-zone soil moisture predictions at the basin scale. High resolution data of the new ASAR (advanced synthetic aperture radar) sensor aboard European Space Agency's Envisat satellite offers the opportunity for monitoring surface soil moisture at high resolution (up to 30 m), which is suitable for distributed mapping within the small scales of typical Mediterranean basins. Indeed, adequate spatio-temporal monitoring of the soil moisture is essential to improve our capability to simulate the water balance. As part of a recently-approved European Space Agency (ESA) Envisat AO project, ASAR-based soil moisture mapping of the Mulargia basin (area of about 65 sq.km), sub-basin of the Flumendosa basin in Sardinia, are available . This semi-arid basin has a key role in the water resources management of Sardinia. Semi-arid regions, such as Sardinia island, suffers from water scarcity, which is increasingly due to the broad desertification processes of the Mediterranean area. Within the basin, land surface fluxes are well monitored through two evapotraspiration measurement systems (one eddy correlation technique based station, and one

  7. High emittance surfaces for high temperature space radiator applications

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Rutledge, Sharon K.; Hotes, Deborah

    1990-01-01

    Surface modification techniques are evaluated for emittance enhancement of radiator surfaces. These techniques include acid etching, heat treating, abrasion, sputter texturing, electrochemical texturing, arc texturing, and atomic oxygen beam texturing. Candidate radiator surface materials under consideration include Nb-1 pct Zr, Cu, Ti, Ti-6 pct Al-4 pct V, 304 stainless steel, Al6061-T6, Mo, W, and Ta.

  8. Surface daytime net radiation estimation using artificial neural networks

    SciTech Connect

    Jiang, Bo; Zhang, Yi; Liang, Shunlin; Zhang, Xiaotong; Xiao, Zhiqiang

    2014-11-11

    Net all-wave surface radiation (Rn) is one of the most important fundamental parameters in various applications. However, conventional Rn measurements are difficult to collect because of the high cost and ongoing maintenance of recording instruments. Therefore, various empirical Rn estimation models have been developed. This study presents the results of two artificial neural network (ANN) models (general regression neural networks (GRNN) and Neuroet) to estimate Rn globally from multi-source data, including remotely sensed products, surface measurements, and meteorological reanalysis products. Rn estimates provided by the two ANNs were tested against in-situ radiation measurements obtained from 251 global sites between 1991–2010 both in global mode (all data were used to fit the models) and in conditional mode (the data were divided into four subsets and the models were fitted separately). Based on the results obtained from extensive experiments, it has been proved that the two ANNs were superior to linear-based empirical models in both global and conditional modes and that the GRNN performed better and was more stable than Neuroet. The GRNN estimates had a determination coefficient (R2) of 0.92, a root mean square error (RMSE) of 34.27 W·m–2 , and a bias of –0.61 W·m–2 in global mode based on the validation dataset. In conclusion, ANN methods are a potentially powerful tool for global Rn estimation.

  9. Surface Electrical Potentials of Root Cell Plasma Membranes: Implications for Ion Interactions, Rhizotoxicity, and Uptake

    PubMed Central

    Wang, Yi-Min; Kinraide, Thomas B.; Wang, Peng; Hao, Xiu-Zhen; Zhou, Dong-Mei

    2014-01-01

    Many crop plants are exposed to heavy metals and other metals that may intoxicate the crop plants themselves or consumers of the plants. The rhizotoxicity of heavy metals is influenced strongly by the root cell plasma membrane (PM) surface’s electrical potential (ψ0). The usually negative ψ0 is created by negatively charged constituents of the PM. Cations in the rooting medium are attracted to the PM surface and anions are repelled. Addition of ameliorating cations (e.g., Ca2+ and Mg2+) to the rooting medium reduces the effectiveness of cationic toxicants (e.g., Cu2+ and Pb2+) and increases the effectiveness of anionic toxicants (e.g., SeO42− and H2AsO4−). Root growth responses to ions are better correlated with ion activities at PM surfaces ({IZ}0) than with activities in the bulk-phase medium ({IZ}b) (IZ denotes an ion with charge Z). Therefore, electrostatic effects play a role in heavy metal toxicity that may exceed the role of site-specific competition between toxicants and ameliorants. Furthermore, ψ0 controls the transport of ions across the PM by influencing both {IZ}0 and the electrical potential difference across the PM from the outer surface to the inner surface (Em,surf). Em,surf is a component of the driving force for ion fluxes across the PM and controls ion-channel voltage gating. Incorporation of {IZ}0 and Em,surf into quantitative models for root metal toxicity and uptake improves risk assessments of toxic metals in the environment. These risk assessments will improve further with future research on the application of electrostatic theory to heavy metal phytotoxicity in natural soils and aquatic environments. PMID:25493475

  10. Restoration of root surface caries in vulnerable elderly patients: a review of the literature.

    PubMed

    Amer, R S; Kolker, J L

    2013-01-01

    The authors conducted a review to evaluate the current literature addressing root surface caries treatment in the vulnerable elderly, to identify any gaps in the literature that will need to be addressed in the future. The authors conducted a literature search of the electronic databases using MEDLINE, PubMed, to identify original clinical research articles regarding treatment of root caries lesions, with emphasis on research focused on the vulnerable elderly. Five articles were clinical studies of root caries restorations. Only one was conducted on a vulnerable elderly population. The results of the literature review show that there is a need for further studies addressing the restorative needs of the vulnerable elderly. With the aging of the American population, more research is needed to provide adequate care to this population. At this time, glass ionomers are a good treatment option. PMID:23600986

  11. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    PubMed

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-12-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1: 13.8% chlorine dioxide, Group 2: 17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5 ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth. PMID:26767238

  12. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    PubMed

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-09-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1:13.8% chlorine dioxide, Group 2:17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth. PMID:26591249

  13. In Vivo Delivery of Tinospora cordifolia Root Extract Preventing Radiation-Induced Dystrophies in Mice Ovaries.

    PubMed

    Sharma, Riddhi

    2015-01-01

    Unconscious and unplanned radiation exposures are a severe threat to gonads particularly ovaries. The present study aims at finding radioprotective effect of Tinospora cordifolia (Willd.) Miers root extract (TCRE) in ovaries. Swiss albino mice were divided into four groups: Group 1 served as "normal" and is administered double distilled water and Group 2 is given TCRE with optimum dosage selected as 75 mg/mice. Group 3 serving the purpose of "irradiated control" were exposed to 2.5 Gy gamma radiation. Group 4 (experimental) were administered optimum dosage of TCRE with prior exposure to 2.5 Gy gamma radiation. Follicle cell counts were scored at autopsy intervals of 24 hrs, 3 days, 7 days, 15 days, and 30 days after gamma irradiation. To understand the mechanism of radioprotection, lipid peroxidation (LPO) and glutathione (GSH) levels were also measured in all groups. TCRE supplementation rendered significant protection to ovaries by restoring follicle counts; it also reduced LPO levels and increased GSH levels in ovaries. It implies that TCRE administration protects ovaries against radiation exposure. PMID:26357520

  14. In Vivo Delivery of Tinospora cordifolia Root Extract Preventing Radiation-Induced Dystrophies in Mice Ovaries

    PubMed Central

    Sharma, Riddhi

    2015-01-01

    Unconscious and unplanned radiation exposures are a severe threat to gonads particularly ovaries. The present study aims at finding radioprotective effect of Tinospora cordifolia (Willd.) Miers root extract (TCRE) in ovaries. Swiss albino mice were divided into four groups: Group 1 served as “normal” and is administered double distilled water and Group 2 is given TCRE with optimum dosage selected as 75 mg/mice. Group 3 serving the purpose of “irradiated control” were exposed to 2.5 Gy gamma radiation. Group 4 (experimental) were administered optimum dosage of TCRE with prior exposure to 2.5 Gy gamma radiation. Follicle cell counts were scored at autopsy intervals of 24 hrs, 3 days, 7 days, 15 days, and 30 days after gamma irradiation. To understand the mechanism of radioprotection, lipid peroxidation (LPO) and glutathione (GSH) levels were also measured in all groups. TCRE supplementation rendered significant protection to ovaries by restoring follicle counts; it also reduced LPO levels and increased GSH levels in ovaries. It implies that TCRE administration protects ovaries against radiation exposure. PMID:26357520

  15. Effect of nickel titanium file design on the root surface strain and apical microcracks.

    PubMed

    Jamleh, Ahmed; Adorno, Carlos G; Ebihara, Arata; Suda, Hideaki

    2016-04-01

    The aim of this study was to determine the effect of nickel titanium file design on the root surface strain generated and apical microcracks caused during canal shaping. Thirty-three mandibular incisors were distributed into LightSpeed X, FlexMaster and a control group. A strain gauge was fixed apically on the proximal root surface to determine the maximum strain during canal shaping. Except for the control group, all root canals were enlarged to size 50. Images were taken after removing the apical 1 and 2 mm of the root end. Mean maximum strain values and presence of microcracks were statistically compared using the t-test and chi-square test, respectively. During canal shaping, the strain increased cumulatively with mean maximum strains of 808.2 ± 228.8 and 525.1 ± 168.9 microstrain in LightSpeed X and FlexMaster, respectively (P = 0.004). Both systems caused comparable microcracks. Although LightSpeed X produced higher maximum strain, no difference in microcrack development was found between both systems. PMID:26420627

  16. The Correlation of Profiles of Surface pH and Elongation Growth in Maize Roots1

    PubMed Central

    Peters, Winfried S.; Felle, Hubert H.

    1999-01-01

    High-resolution profiles of surface pH and growth along vertically growing maize (Zea mays) primary root tips were determined simultaneously by pH-sensitive microelectrodes and marking experiments. Methodological tests were carried out that proved the reliability of our kinematic growth analysis, while questioning the validity of an alternative technique employed previously. A distal acidic zone around the meristematic region and a proximal one around the elongation zone proper were detected. This pattern as such persisted irrespective of the bulk pH value. The proximal acidic region coincided with maximum relative elemental growth rates (REGR), and both characters reacted in a correlated manner to auxin and cyanide. The distal acidic band was unrelated to growth, but was abolished by cyanide treatment. We conclude that: (a) the pattern of surface pH as such is a regulated feature of growing root tips; (b) the correlation of extracellular pH and growth rate suggests a functional relationship only along proximal portions of the growing root tip; and (c) the distal acidic band is not caused by pH buffering by root cap mucilage, as suggested previously, but rather is controlled by cellular activity. PMID:10557239

  17. Subcellular distribution of uranium in the roots of Spirodela punctata and surface interactions

    NASA Astrophysics Data System (ADS)

    Nie, Xiaoqin; Dong, Faqin; Liu, Ning; Liu, Mingxue; Zhang, Dong; Kang, Wu; Sun, Shiyong; Zhang, Wei; Yang, Jie

    2015-08-01

    The subcellular distribution of uranium in roots of Spirodela punctata (duckweed) and the process of surface interaction were studied upon exposure to U (0, 5-200 mg/L) at pH 5. The concentration of uranium in each subcelluar fraction increased significantly with increasing solution U level, after 200 mg/L uranium solution treatment 120 h, the proportion of uranium concentration approximate as 8:2:1 in the cell wall organelle and cytosol fractions of roots of S. punctata. OM SEM and EDS showed after 5-200 mg/L U treatment 4-24 h, some intracellular fluid released from the root cells, after 100 mg/L U treatment 48 h, the particles including 35% Fe (wt%) and other organic matters such as EPS released from the cells, most of the uranium bound onto the root surface and contacted with phosphorus ligands and formed as nano-scales U-P lamellar crystal, similar crystal has been found in the cell wall and organelle fractions after 50 mg/L U treatment 120 h. FTIR and XPS analyses result indicates the uranium changed the band position and shapes of phosphate group, and the region of characteristic peak belongs to U(VI) and U(IV) were also observed.

  18. Strain Distribution in Root Surface Dentin of Maxillary Central Incisors during Lateral Compaction

    PubMed Central

    Pilo, Raphael; Metzger, Zvi; Brosh, Tamar

    2016-01-01

    Aim To precisely quantify the circumferential strains created along the radicular dentin of maxillary incisors during a simulated clinical procedure of lateral compaction. Methods Six miniature strain gauges were bonded on the roots of fourteen recently extracted maxillary central incisors that were subjected to root canal instrumentation. The strain gauges were bonded at three levels (apical, middle, and coronal) and four aspects (buccal, lingual, mesial, and distal) of the roots. Each tooth was embedded in a PVC cylinder containing polyvinyl-siloxane impression material. Root filling was then performed by simulating the clinical procedure of lateral compaction using nickel-titanium finger spreaders. The force applied to the spreader and the strains developing in the surface root dentin were continuously recorded at a frequency of 10 Hz. Results The highest strains that developed during lateral compaction were in the mesial and distal aspects at the apical level of the root. The magnitudes of the maximal mesial/distal strains at the apical as well as the mid-root levels were approximately 2.5–3 times higher than those at the buccal/lingual aspects (p = 0.041). The strains decreased significantly (p<0.04) from the apical through the mid-root levels to the coronal level, yielding gradients of 2.5- and 6-fold, respectively. The mesial and distal strains were consistently tensile and did not differ significantly; however, the buccal strains were generally 35–65% higher than the lingual strains (p = 0.078). Lateral compaction resulted in the gradual build-up of residual strains, resulting in generation of a 'stair-step' curve. These strains declined gradually and almost completely disappeared after 1000 sec. Conclusions With proper mounting of several miniature strain gauges at various levels and aspects of the root, significant circumferential strains can be monitored under clinically relevant compaction forces. The residual strains at the end of lateral

  19. Scanning electron microscopy study to analyze the morphological characteristics of root surfaces after application of Carisolv gel in association with scaling and root planing: In vitro study

    PubMed Central

    Verma, Sharmila J.; Gohil, Meera H.

    2012-01-01

    Context: There has been considerable interest in the use of chemical-assisted root detoxification. Chemical agents have been proposed to facilitate calculus removal. Aims: A study was carried out to analyze the morphological characteristics of the root surfaces after application of Carisolv gel in association with scaling and root planing under scanning electron microscopy (SEM). Settings and Design: The Department of Periodontics of the K. M. Shah Dental College and Hospital, Vadodara, (Gujarat, India). Materials and Methods: Sixty periodontally compromised extracted human teeth were randomly assigned to four groups: (1) scaling and root planning (SRP) alone; (2) passive topical application of Carisolv + SRP; (3) active topical application of Carisolv + SRP; (4) multiple applications of Carisolv + SRP. Carisolv gel was applied to the root surfaces for 30 seconds, followed by scaling and root planing, consisting of 30 strokes, with Gracey curettes in an apical-coronal direction, parallel to the long axis of the tooth. The only exception was group 4, where the roots were instrumented until a smooth, hard, and glass-like surface was achieved. All specimens were further analyzed by SEM. Statistical Analysis: The Analysis of Variance (ANOVA) method was used. Results: Active application of Carisolv gel produced more extensive morphological changes than passive application and SRP alone. When multiple applications of Carisolv with SRP were performed, there was a significant decrease in the smear layer compared to a single application of the gel, either passively or actively. Conclusions: The Carisolv gel failed to remove the smear layer completely, especially with a single application, independently of the method of application. This study documented that the Carisolv gel produced changes in the root morphology of periodontally compromised teeth, only when it was applied actively and multiple times. PMID:23162324

  20. Climate radiative feedbacks and adjustments at the Earth's surface

    NASA Astrophysics Data System (ADS)

    Colman, R. A.

    2015-04-01

    Climate radiative feedbacks are traditionally defined at top of atmosphere (TOA); however, strong radiative feedbacks also occur at the surface, with profound effect on the surface heat budget and hydrological cycle. "Rapid responses" to radiative forcing also occur and may also be expected to affect the surface. This study evaluates surface radiation changes, using a combined Partial Radiative Perturbation-Gregory approach, under abrupt increases in CO2 in a climate model. We find significant surface rapid radiative response from changes in clouds, relative humidity, and latent heat flux. As surface temperature increases, strong water vapor feedback exceeds net cooling from atmospheric and surface temperature changes, resulting in increased surface evaporation. Feedbacks from clouds are smaller, with complex horizontal and vertical structures. Surface longwave feedback structures differ widely from those of the TOA and are dominated by lower troposphere changes. Lapse rate, cloud, and albedo feedbacks are small equatorward of around 50° of latitude but stronger at high latitudes. The approach here allows precise evaluation of the rich structure of surface radiative feedbacks.

  1. Effect of energy (J) on temperature changes at apical root surface when using Er:YAG laser to enlarge root canals

    NASA Astrophysics Data System (ADS)

    Pecora, Jesus D.; Brugnera, Aldo, Jr.; Zanin, Fatima A. A.; Marchesan, Melissa A.; Daghastanli, Naser A.; Silva, Reginaldo S.

    2000-03-01

    The use of lasers for cleaning, shaping and disinfecting root canals must not produce heat which damages periapical tissue and alveolar bone. The aim of the present study was to determine the increase of external temperature at the apical surface of the root canal after Er:YAG laser irradiation with a 250 micrometer diameter fiberoptic guide with and without distilled and deionized water at 3 different total energies. Thirty single-rooted teeth were instrumented to #25 K-file using distilled and deionized water for irrigation. They were divided into three groups according to total energy (15J, 30J and 45J with 15 Hz and 140 mJ per pulse). Each group was irradiated with water and then without water. The increase in temperature at the apical root surface was measured with a multimeter and a thermocouple. Changes in apical temperature were significantly different in all groups (p less than 0.01; 15 J less than 45 J less than 30 J). Less time was necessary for return to initial room temperature at 15 J. We conclude that in vitro use of the Er:YAG laser (total energy of 15, 30, and 45 J) increased external apical root temperature and that the root canal must be filled with distilled and deionized water to reduce the risk of an increase in temperature.

  2. Spoof plasmon radiation using sinusoidally modulated corrugated reactance surfaces.

    PubMed

    Panaretos, Anastasios H; Werner, Douglas H

    2016-02-01

    In this paper we theoretically investigate the feasibility of creating leaky wave antennas capable of converting spoof plasmons to radiating modes. Spoof plasmons are surface waves excited along metallic corrugated surfaces and they are considered the microwave and THz equivalent of optical surface plasmon polaritons. Given that a corrugated surface is essentially a reactance surface, the proposed design methodology relies on engineering a corrugated surface so that it exhibits a sinusoidally modulated reactance profile. Through such non-uniform periodic reactance surfaces, guided surface waves can efficiently couple into free-space radiating modes. This requires the development of a realistic methodology that effectively maps the necessary sinusoidal reactance variation to a sinusoidal variation corresponding to the depth of the grooves. Both planar and cylindrical corrugated surfaces are examined and it is numerically demonstrated that the corresponding sinusoidally modulated leaky wave structures can very efficiently convert guided spoof plasmons to radiating modes. PMID:26906820

  3. Net surface radiation retrieval using Earth Observation Satellite data and machine learning algorithm

    NASA Astrophysics Data System (ADS)

    Mahalakshmi, D. V.; Paul, A.; Dutta, D.; Ali, M. M.; Jha, C. S.; Dadhwal, V. K.

    2014-11-01

    We present a method to estimate net surface radiation (NSR) from Terra MODIS data using Artificial Neural Network (ANN) technique. For this purpose, we trained the ANN model using MODIS atmospheric profile product of air temperature, dew point temperature, solar zenith angle and land surface temperature from Terra as independent parameters and the net surface radiation from eddy flux tower measurements at Bonnie camp location of Sundarban region as the dependent variable. The NSR is estimated with a root mean square accuracy of 64 w/m2 and the square of the correlation coefficient (R2) is 0.75 respectively. This technique is extended to estimate NSR over the entire Sundarban area and has a potential for climate and agricultural water management studies.

  4. A new method to estimate average hourly global solar radiation on the horizontal surface

    NASA Astrophysics Data System (ADS)

    Pandey, Pramod K.; Soupir, Michelle L.

    2012-10-01

    A new model, Global Solar Radiation on Horizontal Surface (GSRHS), was developed to estimate the average hourly global solar radiation on the horizontal surfaces (Gh). The GSRHS model uses the transmission function (Tf,ij), which was developed to control hourly global solar radiation, for predicting solar radiation. The inputs of the model were: hour of day, day (Julian) of year, optimized parameter values, solar constant (H0), latitude, and longitude of the location of interest. The parameter values used in the model were optimized at a location (Albuquerque, NM), and these values were applied into the model for predicting average hourly global solar radiations at four different locations (Austin, TX; El Paso, TX; Desert Rock, NV; Seattle, WA) of the United States. The model performance was assessed using correlation coefficient (r), Mean Absolute Bias Error (MABE), Root Mean Square Error (RMSE), and coefficient of determinations (R2). The sensitivities of parameter to prediction were estimated. Results show that the model performed very well. The correlation coefficients (r) range from 0.96 to 0.99, while coefficients of determination (R2) range from 0.92 to 0.98. For daily and monthly prediction, error percentages (i.e. MABE and RMSE) were less than 20%. The approach we proposed here can be potentially useful for predicting average hourly global solar radiation on the horizontal surface for different locations, with the use of readily available data (i.e. latitude and longitude of the location) as inputs.

  5. Effect of Mulch Surface Color on Root-knot of Tomato Grown in Simulated Planting Beds.

    PubMed

    Fortnum, B A; Kasperbauer, M J; Decoteau, D R

    2000-03-01

    The effect of different-colored polyethylene mulches on quantity and spectra of reflected light, plant morphology, and root-knot disease was studied in tomato (Lycopersicon esculentum) grown in simulated planting beds. Tomato plants were inoculated with Meloidogyne incognita at initial populations (Pi) of 0, 1,000, 10,000, or 50,000 eggs/plant, and grown in a greenhouse for 50 days over white, red, or black mulch. Soil temperature was kept constant among the mulch treatments by placing an insulation barrier between the colored mulch and the soil surface. Soil temperature varied less than 0.5 degrees C between soil chambers at solar noon. Tomatoes grown over white mulch received more reflected photosynthetic light and had greater shoot weights (27%), root weights (32%), and leaf area (20%) than plants grown over black mulch. Plants grown over red mulch received a higher far-red-to-red ratio in the reflected light. Mulch color altered the plant's response to root-knot nematode infection by changing the distribution of mass in axillary shoots. At high Pi, axillary leaf area and leaf weight were greater in tomato grown over white mulch than when grown over red mulch. The root-gall index was lower for plants grown over white mulch than similar plants grown over red mulch. PMID:19270954

  6. Measurement of solar radiation at the Earth's surface

    NASA Technical Reports Server (NTRS)

    Bartman, F. L.

    1982-01-01

    The characteristics of solar energy arriving at the surface of the Earth are defined and the history of solar measurements in the United States presented. Radiation and meteorological measurements being made at solar energy meteorological research and training sites and calibration procedures used there are outlined. Data illustrating the annual variation in daily solar radiation at Ann Arbor, Michigan and the diurnal variation in radiation at Albuquerque, New Mexico are presented. Direct normal solar radiation received at Albuquerque is contrasted with that received at Maynard, Massachusetts. Average measured global radiation for a period of one year for four locations under clear skies, 50% cloud cover, and 100% cloud cover is given and compared with the solar radiation at the top of the atmosphere. The May distribution of mean daily direct solar radiation and mean daily global solar radiation over the United States is presented. The effects of turbidity on the direct and circumsolar radiation are shown.

  7. Morphological Changes Of The Root Surface And Fracture Resistance After Treatment Of Root Fracture By CO2 Laser And Glass Ionomer Or Mineral Trioxide Aggregates

    NASA Astrophysics Data System (ADS)

    Badr, Y. A.; Abd El-Gawad, L. M.; Ghaith, M. E.

    2009-09-01

    This in vitro study evaluates the morphological changes of the root surface and fracture resistance after treatment of root cracks by CO2 laser and glass Ionomer or mineral trioxide aggregates (MTA). Fifty freshly extracted human maxillary central incisor teeth with similar dimension were selected. Crowns were sectioned at the cemento-enamel junction, and the lengths of the roots were adjusted to 13 mm. A longitudinal groove with a dimension of 1×5 mm2 and a depth of 1.5 mm was prepared by a high speed fissure bur on the labial surface of the root. The roots were divided into 5 groups: the 10 root grooves in group 1 were remained unfilled and were used as a control group. The 10 root grooves in group 2 were filled with glass Ionomer, 10 root grooves in group 3 were filled with MTA, the 10 root grooves in group 4 were filled with glass Ionomer and irradiated by CO2 laser and the 10 root grooves in group 5 were filled with MTA and irradiated with CO2 laser. Scanning electron microscopy was performed for two samples in each group. Tests for fracture strength were performed using a universal testing machine and a round tip of a diameter of 4 mm. The force was applied vertically with a constant speed of 1 mm min 1. For each root, the force at the time of fracture was recorded in Newtons. Results were evaluated statistically with ANOVA and Turkey's Honestly Significant Difference (HSD) tests. SEM micrographs revealed that the melted masses and the plate-like crystals formed a tight Chemical bond between the cementum and glass Ionomer and melted masses and globular like structure between cementum and MTA. The mean fracture resistance was the maximum fracture resistance in group 5 (810.8 N). Glass Ionomer and MTA with the help of CO2 laser can be an alternative to the treatment of tooth crack or fracture. CO2 laser increase the resistance of the teeth to fracture.

  8. Surface Radiation from GOES: A Physical Approach; Preprint

    SciTech Connect

    Habte, A.; Sengupta, M.; Wilcox, S.

    2012-09-01

    Models to compute Global Horizontal Irradiance (GHI) and Direct Normal Irradiance (DNI) have been in development over the last 3 decades. These models can be classified as empirical or physical, based on the approach. Empirical models relate ground based observations with satellite measurements and use these relations to compute surface radiation. Physical models consider the radiation received from the earth at the satellite and create retrievals to estimate surface radiation. While empirical methods have been traditionally used for computing surface radiation for the solar energy industry the advent of faster computing has made operational physical models viable. The Global Solar Insolation Project (GSIP) is an operational physical model from NOAA that computes GHI using the visible and infrared channel measurements from the GOES satellites. GSIP uses a two-stage scheme that first retrieves cloud properties and uses those properties in a radiative transfer model to calculate surface radiation. NREL, University of Wisconsin and NOAA have recently collaborated to adapt GSIP to create a 4 km GHI and DNI product every 30 minutes. This paper presents an outline of the methodology and a comprehensive validation using high quality ground based solar data from the National Oceanic and Atmospheric Administration (NOAA) Surface Radiation (SURFRAD) (http://www.srrb.noaa.gov/surfrad/sitepage.html) and Integrated Surface Insolation Study (ISIS) http://www.srrb.noaa.gov/isis/isissites.html), the Solar Radiation Research Laboratory (SRRL) at National Renewable Energy Laboratory (NREL), and Sun Spot One (SS1) stations.

  9. Treatment of root surface in delayed tooth replantation: a review of literature.

    PubMed

    Panzarini, Sônia Regina; Gulinelli, Jéssica Lemos; Poi, Wilson Roberto; Sonoda, Celso Koogi; Pedrini, Denise; Brandini, Daniela Atili

    2008-06-01

    The time elapsed between a trauma and tooth replantation usually ranges from 1 to 4 h. The chances of root surface damage are higher when tooth replantation is not performed immediately or if the avulsed tooth is not stored in an adequate medium. This invariably leads to necrosis of pulp tissue, periodontal ligament cells and cementum, thus increasing the possibility of root resorption, which is the main cause of loss of replanted teeth. This paper presents a comprehensive review of literature on root surface treatments performed in cases of delayed tooth replantation with necrotic cemental periodontal ligament. Journal articles retrieved from PubMed/MedLine, Bireme and Scielo databases were reviewed. It was observed that, when there are no periodontal ligament remnants and contamination is under control, replacement resorption and ankylosis are the best results and that, although these events will end up leading to tooth loss, this will happen slowly with no loss of the alveolar ridge height, which is important for future prosthesis planning. PMID:18410388

  10. Radiation protection for human interplanetary spaceflight and planetary surface operations

    SciTech Connect

    Clark, B.C. ||

    1993-12-31

    Radiation protection issues are reviewed for five categories of radiation exposure during human missions to the moon and Mars: trapped radiation belts, galactic cosmic rays, solar flare particle events, planetary surface emissions, and on-board radiation sources. Relative hazards are dependent upon spacecraft and vehicle configurations, flight trajectories, human susceptibility, shielding effectiveness, monitoring and warning systems, and other factors. Crew cabins, interplanetary mission modules, surface habitats, planetary rovers, and extravehicular mobility units (spacesuits) provide various degrees of protection. Countermeasures that may be taken are reviewed relative to added complexity and risks that they could entail, with suggestions for future research and analysis.

  11. Texturing Carbon-carbon Composite Radiator Surfaces Utilizing Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Raack, Taylor

    2004-01-01

    Future space nuclear power systems will require radiator technology to dissipate excess heat created by a nuclear reactor. Large radiator fins with circulating coolant are in development for this purpose and an investigation of how to make them most efficient is underway. Maximizing the surface area while minimizing the mass of such radiator fins is critical for obtaining the highest efficiency in dissipating heat. Processes to develop surface roughness are under investigation to maximize the effective surface area of a radiator fin. Surface roughness is created through several methods including oxidation and texturing. The effects of atomic oxygen impingement on carbon-carbon surfaces are currently being investigated for texturing a radiator surface. Early studies of atomic oxygen impingement in low Earth orbit indicate significant texturing due to ram atomic oxygen. The surface morphology of the affected surfaces shows many microscopic cones and valleys which have been experimentally shown to increase radiation emittance. Further study of this morphology proceeded in the Long Duration Exposure Facility (LDEF). Atomic oxygen experiments on the LDEF successfully duplicated the results obtained from materials in spaceflight by subjecting samples to 4.5 eV atomic oxygen from a fixed ram angle. These experiments replicated the conical valley morphology that was seen on samples subjected to low Earth orbit.

  12. Predicting root zone soil moisture with satellite near-surface moisture data in semiarid environments

    NASA Astrophysics Data System (ADS)

    Manfreda, S.; Baldwin, D. C.; Keller, K.; Smithwick, E. A. H.; Caylor, K. K.

    2015-12-01

    One of the most critical variables in semiarid environment is the soil water content that represents a controlling factor for both ecological and hydrological processes. Soil moisture monitoring over large scales may be extremely useful, but it is limited by the fact that most of the available tools provides only surface measurements not representative of the effective amount of water stored in the subsurface. Therefore, a methodology able to infer root-zone soil moisture starting from surface measurements is highly desirable. Recently a new simplified formulation has been introduced to provide a formal description of the mathematical relationship between surface measurements and root-zone soil moisture (Manfreda et al., HESS 2014). This is a physically based approach derived from the soil water balance equation, where different soil water loss functions have been explored in order to take into account for the non-linear processes governing soil water fluxes. The study highlighted that the soil loss function is the key for such relationship that is therefore strongly influenced by soil type and physiological plant types. The new formulation has been tested on soil moisture based on measurements taken from the African Monsoon Multidisciplinary Analysis (AMMA) and the Soil Climate Analysis Network (SCAN) databases. The method sheds lights on the physical controls for soil moisture dynamics and on the possibility to use such a simplified method for the description of root-zone soil moisture. Furthermore, the method has been also couple with an Enasamble Kalman Filter (EnKF) in order to optimize its performances for the large scale monitoring based the new satellite near-surface moisture data (SMAP). The optimized SMAR-EnKF model does well in both wet and dry climates and across many different soil types (51 SCAN locations) providing a strategy for real-time soil moisture monitoring.

  13. Evaluation of Arctic Broadband Surface Radiation Measurements

    SciTech Connect

    Matsui, N.; Long, Charles N.; Augustine, J. A.; Halliwell, D.; Uttal, Taneil; Longenecker, D.; Niebergale, J.; Wendell, J.; Albee, R.

    2012-02-24

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  14. Evaluation of arctic broadband surface radiation measurements

    NASA Astrophysics Data System (ADS)

    Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Nievergall, O.; Wendell, J.; Albee, R.

    2011-08-01

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  15. Effect of UV-C radiation and vapor released from a water hyacinth root absorbent containing bergamot oil to control mold on storage of brown rice.

    PubMed

    Songsamoe, Sumethee; Matan, Narumol; Matan, Nirundorn

    2016-03-01

    The aims of this study were to develop absorbent material from a water hyacinth root containing bergamot oil and to improve its antifungal activity by using ultraviolet C (UV-C) against the growth of A. flavus on the brown rice. Process optimization was studied by the immersion of a water hyacinth root into a water and bergamot oil (300, 500 and 700 μl ml(-1)). The root (absorbent material) was dried at 50, 70, and 90 °C for 10 min. Then, ultraviolet C (UV-C) was used for enhancing the antifungal activity of bergamot oil for 10, 15, and 20 min. The shelf-life of the brown rice with the absorbent after incubation at 25 ° C with 100 % RH for 12 weeks was also investigated. A microscope and a Fourier transform infrared spectroscopy (FTIR) were used to find out possible mode of action. Results indicated that the absorbent material produced from the water hyacinth root containing bergamot oil at 500 μl ml(-1) in the water solution, dried at 70 ° C and UV for 15 min showed the highest antifungal activity in a vapor phase against A. flavus on the brown rice. A microscopy investigation confirmed that the water hyacinth root could absorb bergamot oil from an outside water solution into root cells. Limonene in vapor phase was shown to be a stronger inhibitor than essential oil after UV-C radiation and should be the key factor in boosting bergamot oil antifungal activity. A vapor phase of bergamot oil could be released and inhibit natural mold on the surface of the brown rice for up to 12 weeks; without the absorbent, mold covered the brown rice in only 4 weeks. PMID:27570269

  16. The Greenhouse Effect - Determination From Accurate Surface Longwave Radiation Measurements

    NASA Astrophysics Data System (ADS)

    Philipona, R.

    Longwave radiation measurements have been drastically improved in recent years. Uncertainty levels down to s2 Wm-2 are realistic and achieved during long-term ´ longwave irradiance measurements. Longwave downward irradiance measurements together with temperature and humidity measurements at the station are used to sepa- rate clear-sky from cloudy-sky situations. Longwave net radiation separated between clear-sky and all-sky situations allows to determine the longwave cloud radiative forc- ing at the station. For clear-sky situations radiative transfer models demonstrate a lin- ear relation between longwave downward radiation and the greenhouse radiative flux. Clear-sky longwave radiation, temperature and humidity for different atmospheres and different altitudes were modeled with the MODTRAN radiative transfer code and compared to longwave radiation, temperature and humidity measured at 4 radiation stations of the Alpine Surface Radiation Budget (ASRB) network at similar altitude and with corresponding atmospheres. At the 11 ASRB stations the clear-sky green- house effect was determined by using clear-sky longwave downward measurements and MODTRAN model calculations. The all-sky greenhouse effect was determined by adding the longwave cloud radiative forcing to the clear-sky greenhouse radiative flux. The altitude dependence of annual and seasonal mean values of the greenhouse effect will be shown for the altitude range of 400 to 3600 meter a.s.l. in the Alps.

  17. Interaction of hyperthermia and radiation: the survival surface.

    PubMed

    Loshek, D D; Orr, J S; Solomonidis, E

    1977-12-01

    The interaction of hyperthermia and radiation on cell survival is illustrated by the increase in sensitivity to radiation caused by hyperthermia and the increase in sensitivity to hyperthermia caused by radiation. A method of expressing the total response to a combination of these two agents by means of a survival surface in three dimensions is explained and discussed. A simple mathematical model of the suface is formulated in which is a first order interaction term is separated from the two terms representing unperturbed radiation survival and unperturbed hyperthermia survival. An experiment is described in which survival data points were obtained for 77 combinations of radiation and hypertermia doses in the form of a matrix. These data points are plotted as 11 radiation survival curves and seven hyperthermia survival curves. The results are also analysed to give the parameters of the survival surface model. The model with its three components is shown to be a good approximation to the experimental results. PMID:588919

  18. Effect of lipid/polysaccharide ratio on surface activity of model root mucilage in its solid and liquid states

    NASA Astrophysics Data System (ADS)

    Chen, Fengxian; Arye, Gilboa

    2016-04-01

    The rhizosphere can be defined as the volume of soil around living roots, which is influenced by root activity. The biological, chemical and physical conditions that prevail in the rhizosphere are significantly different from those of the bulk soil. Plant roots can release diverse organic materials in the rhizosphere which may have different effects on its bio-chemo-physical activity. Among these exudates is the root mucilage which can play a role on the maintenance of root-soil contact, lubrication of the root tip, protection of roots from desiccation and disease, stabilization of soil micro-aggregates and the selective absorption and storage of ions. The surface activity of the root mucilage at the liquid-air interface deduced from its surface tension depression relative to water, implying on its amphiphilic nature. Consequently as the rhizosphere dry out, hydrophobic functional groups may exhibit orientation at the solid-air interface and thus, the wettability of the rhizosphere may temporarily decrease. The major fraction of the root mucilage comprise of polysaccharides and to a much lesser extent, amino acids, organic acids, and phospholipids. The most frequent polysaccharide and phospholipids detected in root mucilage are polygalacturonic acid (PGA) and Phosphatidylcholine (PC), respectively. The latter, is thought to be main cause for the surface active nature of root mucilage. Nevertheless, the role and function of root mucilage in the rhizosphere is commonly studied based on model root mucilage that comprise of only one component, where the most frequent ones are PGA or PC (or lecithin). The main objective of this study was to quantify the effect of concentration and PGA/PC ratios on the wettability of a model rhizosphere soil and the surface tension of the model root mucilage at the liquid-air interface. The PGA/PC mixtures were measured for their equilibrium and dynamic surface tension using the Wilhelmy-Plate method. Quartz sand or glass slides were

  19. Harmonics radiation of graphene surface plasmon polaritons in terahertz regime

    NASA Astrophysics Data System (ADS)

    Li, D.; Wang, Y.; Nakajima, M.; Hashida, M.; Wei, Y.; Miyamoto, S.

    2016-06-01

    This letter presents an approach to extract terahertz radiation from surface plasmon polaritons excited in the surface of a uniform graphene structure by an electron beam. A sidewall configuration is proposed to lift the surface plasmon mode to be close to the light line, so that some of its harmonics have chances to go above the light line and become radiative. The harmonics are considered to be excited by a train of periodic electron bunches. The physical mechanism in this scheme is analyzed with three-dimensional theory, and the harmonics excitation and radiation are demonstrated through numerical calculations. The results show that this technique could be an alternative to transform the surface plasmon polaritons into radiation.

  20. Exposure to 915 MHz radiation induces micronuclei in Vicia faba root tips.

    PubMed

    Gustavino, Bianca; Carboni, Giovanni; Petrillo, Roberto; Paoluzzi, Giovanni; Santovetti, Emanuele; Rizzoni, Marco

    2016-03-01

    The increasing use of mobile phones and wireless networks raised a great debate about the real carcinogenic potential of radiofrequency-electromagnetic field (RF-EMF) exposure associated with these devices. Conflicting results are reported by the great majority of in vivo and in vitro studies on the capability of RF-EMF exposure to induce DNA damage and mutations in mammalian systems. Aimed at understanding whether less ambiguous responses to RF-EMF exposure might be evidenced in plant systems with respect to mammalian ones, in the present work the mutagenic effect of RF-EMF has been studied through the micronucleus (MN) test in secondary roots of Vicia faba seedlings exposed to mobile phone transmission in controlled conditions, inside a transverse electro magnetic (TEM) cell. Exposure of roots was carried out for 72h using a continuous wave (CW) of 915 MHz radiation at three values of equivalent plane wave power densities (23, 35 and 46W/m(2)). The specific absorption rate (SAR) was measured with a calorimetric method and the corresponding values were found to fall in the range of 0.4-1.5W/kg. Results of three independent experiments show the induction of a significant increase of MN frequency after exposure, ranging from a 2.3-fold increase above the sham value, at the lowest SAR level, up to a 7-fold increase at the highest SAR. These findings are in agreement with the limited number of data on cytogenetic effects detected in other plant systems exposed to mobile phone RF-EMF frequencies and clearly show the capability of radiofrequency exposure to induce DNA damage in this eukaryotic cell system. PMID:26476436

  1. Heat generation on root surfaces after KTP:NdYAG use in endodontic treatment

    NASA Astrophysics Data System (ADS)

    Nammour, S.; Kowalyk, Kenneth; Valici, Ch.; Guillaume, Patrick

    1997-05-01

    The canals of 30 recently extracted human teeth were filled with a photosensitizer. A series of 5 shots, separated by a resting time of 1 second also, was delivered by means of the KTP:YAG fiber tip. The temperature increases were measured on the topical point of the root surfaces by the use of a thermocouple. For laser settings, the rises were always below the safety threshold of 7 C. We conclude that the KTP:NdYAG laser can be harmless for periodontal tissues under some conditions.

  2. Proximity of the mandibular molar root apex from the buccal bone surface: a cone-beam computed tomographic study

    PubMed Central

    Kim, Dokyung; Jin, Myoung-Uk

    2016-01-01

    Objectives The purpose of this study was to evaluate the proximity of the mandibular molar apex to the buccal bone surface in order to provide anatomic information for apical surgery. Materials and Methods Cone-beam computed tomography (CBCT) images of 127 mandibular first molars and 153 mandibular second molars were analyzed from 160 patients' records. The distance was measured from the buccal bone surface to the root apex and the apical 3.0 mm on the cross-sectional view of CBCT. Results The second molar apex and apical 3 mm were located significantly deeper relative to the buccal bone surface compared with the first molar (p < 0.01). For the mandibular second molars, the distance from the buccal bone surface to the root apex was significantly shorter in patients over 70 years of age (p < 0.05). Furthermore, this distance was significantly shorter when the first molar was missing compared to nonmissing cases (p < 0.05). For the mandibular first molars, the distance to the distal root apex of one distal-rooted tooth was significantly greater than the distance to the disto-buccal root apex (p < 0.01). In mandibular second molar, the distance to the apex of C-shaped roots was significantly greater than the distance to the mesial root apex of non-C-shaped roots (p < 0.01). Conclusions For apical surgery in mandibular molars, the distance from the buccal bone surface to the apex and apical 3 mm is significantly affected by the location, patient age, an adjacent missing anterior tooth, and root configuration. PMID:27508159

  3. The SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) Product

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf; Crow, Wade; Koster, Randal; Kimball, John

    2010-01-01

    The Soil Moisture Active and Passive (SMAP) mission is being developed by NASA for launch in 2013 as one of four first-tier missions recommended by the U.S. National Research Council Committee on Earth Science and Applications from Space in 2007. The primary science objectives of SMAP are to enhance understanding of land surface controls on the water, energy and carbon cycles, and to determine their linkages. Moreover, the high resolution soil moisture mapping provided by SMAP has practical applications in weather and seasonal climate prediction, agriculture, human health, drought and flood decision support. In this paper we describe the assimilation of SMAP observations for the generation of the planned SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) product. The SMAP mission makes simultaneous active (radar) and passive (radiometer) measurements in the 1.26-1.43 GHz range (L-band) from a sun-synchronous low-earth orbit. Measurements will be obtained across a 1000 km wide swath using conical scanning at a constant incidence angle (40 deg). The radar resolution varies from 1-3 km over the outer 70% of the swath to about 30 km near the center of the swath. The radiometer resolution is 40 km across the entire swath. The radiometer measurements will allow high-accuracy but coarse resolution (40 km) measurements. The radar measurements will add significantly higher resolution information. The radar is however very sensitive to surface roughness and vegetation structure. The combination of the two measurements allows optimal blending of the advantages of each instrument. SMAP directly observes only surface soil moisture (in the top 5 cm of the soil column). Several of the key applications targeted by SMAP, however, require knowledge of root zone soil moisture (approximately top 1 m of the soil column), which is not directly measured by SMAP. The foremost objective of the SMAP L4_SM product is to fill this gap and provide estimates of root zone soil moisture

  4. Surface plasmons leaky radiation of the flat metal

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Hu, Dejiao; Pang, Lin

    2015-08-01

    Surface plasmons have been widely investigated in many fields due to the unique property. ATR (attenuated totalreflection) is the common method to excite surface plasmons. We derive the Fano-type analysis to present the reflection spectrum of ATR configuration derived from the three-layer Fresnel reflection equation, which are asymmetric curves resulted from interference between direct reflectance and surface plasmons leaky radiation. In the fitting progress, we obtain the relationship between surface plasmons leaky radiation and metal thickness. When the metal thickness is greater than 25nm, surface plasmons leaky radiation rate is less than 0.07. We also compare the ATR and grating coupler excitement mechanism, which provide a reference to evaluate their application.

  5. Annual Cycle of Cloud Forcing of Surface Radiation Budget

    NASA Technical Reports Server (NTRS)

    Wilber, Anne C.; Smith, G. Louis; Stackhouse, Paul W., Jr.; Gupta, Shashi K.

    2006-01-01

    The climate of the Earth is determined by its balance of radiation. The incoming and outgoing radiation fluxes are strongly modulated by clouds, which are not well understood. The Earth Radiation Budget Experiment (Barkstrom and Smith, 1986) provided data from which the effects of clouds on radiation at the top of the atmosphere (TOA) could be computed (Ramanathan, 1987). At TOA, clouds increase the reflected solar radiation, tending to cool the planet, and decrease the OLR, causing the planet to retain its heat (Ramanathan et al., 1989; Harrison et al., 1990). The effects of clouds on radiation fluxes are denoted cloud forcing. These shortwave and longwave forcings counter each other to various degrees, so that in the tropics the result is a near balance. Over mid and polar latitude oceans, cloud forcing at TOA results in large net loss of radiation. Here, there are large areas of stratus clouds and cloud systems associated with storms. These systems are sensitive to surface temperatures and vary strongly with the annual cycle. During winter, anticyclones form over the continents and move to the oceans during summer. This movement of major cloud systems causes large changes of surface radiation, which in turn drives the surface temperature and sensible and latent heat released to the atmosphere.

  6. Radiation exposure for manned Mars surface missions

    SciTech Connect

    Simonsen, L.C.; Nealy, J.E.; Townsend, L.W.; Wilson, J.W.

    1990-03-01

    The Langley cosmic ray transport code and the Langley nucleon transport code (BRYNTRN) are used to quantify the transport and attenuation of galactic cosmic rays (GCR) and solar proton flares through the Martian atmosphere. Surface doses are estimated using both a low density and a high density carbon dioxide model of the atmosphere which, in the vertical direction, provides a total of 16 g/sq cm and 22 g/sq cm of protection, respectively. At the Mars surface during the solar minimum cycle, a blood-forming organ (BFO) dose equivalent of 10.5 to 12 rem/yr due to galactic cosmic ray transport and attenuation is calculated. Estimates of the BFO dose equivalents which would have been incurred from the three large solar flare events of August 1972, November 1960, and February 1956 are also calculated at the surface. Results indicate surface BFO dose equivalents of approximately 2 to 5, 5 to 7, and 8 to 10 rem per event, respectively. Doses are also estimated at altitudes up to 12 km above the Martian surface where the atmosphere will provide less total protection.

  7. Radiation exposure for manned Mars surface missions

    NASA Technical Reports Server (NTRS)

    Simonsen, Lisa C.; Nealy, John E.; Townsend, Lawrence W.; Wilson, John W.

    1990-01-01

    The Langley cosmic ray transport code and the Langley nucleon transport code (BRYNTRN) are used to quantify the transport and attenuation of galactic cosmic rays (GCR) and solar proton flares through the Martian atmosphere. Surface doses are estimated using both a low density and a high density carbon dioxide model of the atmosphere which, in the vertical direction, provides a total of 16 g/sq cm and 22 g/sq cm of protection, respectively. At the Mars surface during the solar minimum cycle, a blood-forming organ (BFO) dose equivalent of 10.5 to 12 rem/yr due to galactic cosmic ray transport and attenuation is calculated. Estimates of the BFO dose equivalents which would have been incurred from the three large solar flare events of August 1972, November 1960, and February 1956 are also calculated at the surface. Results indicate surface BFO dose equivalents of approximately 2 to 5, 5 to 7, and 8 to 10 rem per event, respectively. Doses are also estimated at altitudes up to 12 km above the Martian surface where the atmosphere will provide less total protection.

  8. Effects of the Nd:YAG laser and combined treatments on in vitro fibroblast attachment to root surfaces.

    PubMed

    Thomas, D; Rapley, J; Cobb, C; Spencer, P; Killoy, W

    1994-01-01

    The purpose of this in vitro study was to evaluate the effects of the Nd:YAG laser either alone or in combination with root planning or air-powder abrasive treatment on fibroblast attachment to non-diseased root surfaces. 28, 4 x 4 mm root specimens and four disc-shaped root specimens 6 mm in diameter were obtained from unerupted 3rd molars. The root segments were randomly assigned to 4 treatment groups: (1) control; (2) laser-only treated; (3) laser treated followed by root planning; (4) laser treated followed by air-powder abrasive treatment. Laser-treated root specimens were exposed for 1 min with the Nd:YAG laser calibrated at an energy setting of 75 mJ at 20 pulses/s using a 320 microns contact fiber. The contact fiber was held parallel to the root segments and the root segments were kept moist with distilled water. Following the prescribed treatments, the root specimens were incubated with fibroblast cultures and then prepared for SEM examination. Results of cell counts of fibroblasts attached to specimens within each treatment group yielded the following means and standard deviations: control groups, 181.64 +/- 44.74; lased only, 78.57 +/- 21.35; lased and root planed 125.35 +/- 26.13; and lased followed by an air-powder abrasive, 177.28 +/- 55.71. Application of ANOVA followed by the Dunn Multiple Comparison test revealed significant differences (p < 0.01) in the number of attached cells between the control and laser-only treated groups; and between the laser-only and laser/air-powder abrasive treated groups.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8126242

  9. Computer-based video digitizer analysis of surface extension in maize roots: kinetics of growth rate changes during gravitropism.

    PubMed

    Ishikawa, H; Hasenstein, K H; Evans, M L

    1991-02-01

    We used a video digitizer system to measure surface extension and curvature in gravistimulated primary roots of maize (Zea mays L.). Downward curvature began about 25 +/- 7 min after gravistimulation and resulted from a combination of enhanced growth along the upper surface and reduced growth along the lower surface relative to growth in vertically oriented controls. The roots curved at a rate of 1.4 +/- 0.5 degrees min-1 but the pattern of curvature varied somewhat. In about 35% of the samples the roots curved steadily downward and the rate of curvature slowed as the root neared 90 degrees. A final angle of about 90 degrees was reached 110 +/- 35 min after the start of gravistimulation. In about 65% of the samples there was a period of backward curvature (partial reversal of curvature) during the response. In some cases (about 15% of those showing a period of reverse bending) this period of backward curvature occurred before the root reached 90 degrees. Following transient backward curvature, downward curvature resumed and the root approached a final angle of about 90 degrees. In about 65% of the roots showing a period of reverse curvature, the roots curved steadily past the vertical, reaching maximum curvature about 205 +/- 65 min after gravistimulation. The direction of curvature then reversed back toward the vertical. After one or two oscillations about the vertical the roots obtained a vertical orientation and the distribution of growth within the root tip became the same as that prior to gravistimulation. The period of transient backward curvature coincided with and was evidently caused by enhancement of growth along the concave and inhibition of growth along the convex side of the curve, a pattern opposite to that prevailing in the earlier stages of downward curvature. There were periods during the gravitropic response when the normally unimodal growth-rate distribution within the elongation zone became bimodal with two peaks of rapid elongation separated by

  10. Computer-based video digitizer analysis of surface extension in maize roots: kinetics of growth rate changes during gravitropism

    NASA Technical Reports Server (NTRS)

    Ishikawa, H.; Hasenstein, K. H.; Evans, M. L.

    1991-01-01

    We used a video digitizer system to measure surface extension and curvature in gravistimulated primary roots of maize (Zea mays L.). Downward curvature began about 25 +/- 7 min after gravistimulation and resulted from a combination of enhanced growth along the upper surface and reduced growth along the lower surface relative to growth in vertically oriented controls. The roots curved at a rate of 1.4 +/- 0.5 degrees min-1 but the pattern of curvature varied somewhat. In about 35% of the samples the roots curved steadily downward and the rate of curvature slowed as the root neared 90 degrees. A final angle of about 90 degrees was reached 110 +/- 35 min after the start of gravistimulation. In about 65% of the samples there was a period of backward curvature (partial reversal of curvature) during the response. In some cases (about 15% of those showing a period of reverse bending) this period of backward curvature occurred before the root reached 90 degrees. Following transient backward curvature, downward curvature resumed and the root approached a final angle of about 90 degrees. In about 65% of the roots showing a period of reverse curvature, the roots curved steadily past the vertical, reaching maximum curvature about 205 +/- 65 min after gravistimulation. The direction of curvature then reversed back toward the vertical. After one or two oscillations about the vertical the roots obtained a vertical orientation and the distribution of growth within the root tip became the same as that prior to gravistimulation. The period of transient backward curvature coincided with and was evidently caused by enhancement of growth along the concave and inhibition of growth along the convex side of the curve, a pattern opposite to that prevailing in the earlier stages of downward curvature. There were periods during the gravitropic response when the normally unimodal growth-rate distribution within the elongation zone became bimodal with two peaks of rapid elongation separated by

  11. Mitigating errors in surface temperature forecasts using approximate radiation updates

    NASA Astrophysics Data System (ADS)

    Hogan, Robin J.; Bozzo, Alessio

    2015-06-01

    Due to computational expense, the radiation schemes in many weather and climate models are called infrequently in time and/or on a reduced spatial grid. The former can lead to a lag in the diurnal cycle of surface temperature, while the latter can lead to large surface temperature errors at coastal land points due to surface fluxes computed over the ocean being used where the skin temperature and surface albedo are very different. This paper describes a computationally efficient solution to these problems, in which the surface longwave and shortwave fluxes are updated every time step and grid point according to the local skin temperature and albedo. In order that energy is conserved, it is necessary to compute the change to the net flux profile consistent with the changed surface fluxes. The longwave radiation scheme has been modified to compute also the rate of change of the profile of upwelling longwave flux with respect to the value at the surface. Then at each grid point and time step, the upwelling flux and heating-rate profiles are updated using the new value of skin temperature. The computational cost of performing approximate radiation updates in the ECMWF model is only 2% of the cost of the full radiation scheme, so increases the overall cost of the model by only of order 0.2%. Testing the new scheme by running daily 5 day forecasts over an 8 month period reveals significant improvement in 2 m temperature forecasts at coastal stations compared to observations.

  12. Surface space-charge dynamics and surface recombination on silicon (111) surfaces measured with combined laser and synchrotron radiation

    SciTech Connect

    Long, J.P.; Sadeghi, H.R.; Rife, J.C.; Kabler, M.N. )

    1990-03-05

    The results of a new experiment, which records transient, pulsed-laser-induced surface photovoltages by following photoemission shifts measured with synchrotron radiation, are reported. Comparison of the surface photovoltage decays with numerical simulations reveals large surface recombination rates for a variety of Si(111) surface preparations. The space-charge layer near the surface is found to govern the surface and bulk carrier concentrations to a remarkable extent, particularly when band bending is large.

  13. The effect of MTAD, an endodontic irrigant, on fibroblast attachment to periodontally affected root surfaces: A SEM analysis

    PubMed Central

    Ghandi, Mostafa; Houshmand, Behzad; Nekoofar, Mohammad H.; Tabor, Rachel K.; Yadeghari, Zahra; Dummer, Paul M. H.

    2013-01-01

    Background: Root surface debridement (RSD) is necessary to create an environment suitable for reattachment of the periodontium. Root surface conditioning may aid the formation of a biocompatible surface suitable for cell reattachment. BioPure™ MTAD (mixture of Doxycycline, citric acid and a detergent) is an endodontic irrigant with antibacterial properties and the ability to remove smear layer. It was hypothesized that MTAD may be useful for root surface conditioning. The efficacy of MTAD as a conditioner was measured by examining fibroblast attachment to root surfaces. Materials and Methods: Thirty-two specimens of human teeth with advanced periodontal disease were used. The surfaces were root planed until smooth. Half of the specimens were treated with 0.9% saline and the other samples with Biopure MTAD. As a negative control group, five further samples were left unscaled with surface calculus. Human gingival fibroblast cells HGF1-PI1 were cultured and poured over the tooth specimens and incubated. After fixation, the samples were sputter-coated with gold and examined with a SEM. The morphology and number of attached, fixed viable cells were examined. The data was analysed using the Mann-Whitney-U statistical test. Results: There was no significant difference between the numbers of attached cells in the experimental group treated with MTAD and the control group treated with saline. Little or no attached cells were seen in the negative control group. Conclusion: RSD created an environment suitable for cell growth and attachment in a laboratory setting. The use of MTAD did not promote the attachment and growth of cells on the surface of human roots following RSD. PMID:23869124

  14. Root Surface Roughness After Scaling and Root Planing with Er:YAG Laser Compared to Hand and Ultrasonic Instruments by Profilometry

    PubMed Central

    Yaghini, Jaber; Naghsh, Narges; Attaei, Elaheh; Birang, Reza; Birang, Ehsan

    2015-01-01

    Objectives: Scaling and root planing (SRP) is one of the most commonly used procedures during periodontal treatment. The aim of this study was to evaluate the root surface roughness after SRP with erbium: yttrium aluminum garnet (Er:YAG) laser compared to ultrasonic and hand instruments. Materials and Methods: In this experimental study, 56 extracted sound single-rooted teeth with moderate level of calculus were selected and randomly divided into four groups: SRP was performed with Er:YAG laser (100 mJ pulse, 1W, 10Hz, VSP and contact mode, with 50% water and air) in group one, hand instrument in group two and ultrasonic tool in group three. Group four was considered as the control group. After SRP, all samples were cut by Servocut cutting machine into pieces with 3×3×2mm dimensions. The samples were mounted in acrylic resin. The surface roughness of the samples was evaluated with profilometry, and the data were analyzed using one-way ANOVA and Tukey’s test in SPSS software. Results: Surface roughness was higher in laser and lower in ultrasonic group compared to other groups. There was a significant difference in surface roughness between laser and ultrasonic groups (P=0.043), but there was no significant difference in surface roughness among other groups (P>0.05). Conclusion: The results of this study showed that surface roughness after SRP with Er:YAG laser was not higher than that after manual SRP, but the former value was higher than that after SRP with ultrasonic instrument. PMID:27559349

  15. The effects of CO2, Nd:YAG and Er:YAG lasers with and without surface coolant on tooth root surfaces. An in vitro study.

    PubMed

    Israel, M; Cobb, C M; Rossmann, J A; Spencer, P

    1997-09-01

    The objective of this study was to compare and contrast the morphologic changes in tooth root surfaces treated in vitro by scaling and root planing followed by irradiation with the Er:YAG laser using air/water surface cooling and the CO2 and Nd:YAG lasers, both with and without surface coolant. The experimental unit consisted of 42 freshly extracted teeth which were divided equally and randomly assigned to the following 7 treatment groups: untreated control, S/RP only, CO2 laser with and without air/water surface cooling, Nd:YAG laser with and without/air water surface cooling, and Er:YAG laser with air/water surface coolant. Specimens treated with CO2 laser irradiation were subjected to energy densities ranging from 100 to 400 J/cm2; those treated with the Nd:YAG from 286 to 1857 J/cm2; and the Er:YAG was used within a range of 20 to 120 J/cm2. The degree of morphologic change following CO2 and Nd:YAG irradiation appeared directly related to energy density but unrelated to the use of surface coolant. Laser induced surface changes included cavitation, globules of melted and resolidified mineral, surface crazing, and production of a superficial char layer. In contrast, the Er:YAG laser produced root surface changes that might be expected from acid etching, i.e., removal of the smear layer and exposure of the collagen matrix. In addition, sharply defined microfractures of the mineralized structure were noted and unlike the CO2 and Nd:YAG lasers, there was no evidence of melting or surface char. Given the parameters of this study, it appears that both the CO2 and Nd:YAG lasers alter the root surface in an undesirable manner. The Er:YAG laser, however, when used at low energy densities shows sufficient potential for root surface modification to warrant further investigation. PMID:9378829

  16. Intracanal Antibiotic Medication for Sustained Root Surface Disinfection–A Laboratory Evaluation

    PubMed Central

    Zaruba, Markus Tobias Winfried; Filli, Tilla; Rechenberg, Dan-Krister; Thurnheer, Thomas; Attin, Thomas; Schmidlin, Patrick Roger

    2015-01-01

    Purpose: To measure the release of an antibiotic mixture of ciprofloxacin, cerfuroxim and metronidazole (TreVitaMix, TVM) through human dentine and to assess the growth inhibition of Fusobacterium nucleatum. Material and Methods: Twenty-four extracted human incisors were scaled and endodontically treated. Root canals were either filled with antibiotic tri-mixture (TVM) or with the carrier material alone (propylene glycol, PG) and were coronally and apically sealed with a flowable composite. Transradicular medicament release was spectrophotometrically measured at 277 nm in simulated body fluid for up to 21 days. In a second part, an agar diffusion assay (F. nucleatum) with representative TVM concentrations as determined in the first part was performed to study the growth inhibition. Samples were anaerobical incubated for 48 h and inhibition zones were measured. Results: TVM was spectrophotometrically detectable in the immersion solution and released in decreasing concentrations up to 21 days (222.5 ± 65.2 mg/ml at day 1 and 35.1 ± 15.6 mg/ml at day 21). In addition, inhibition zones were shown in the agar diffusion assay at representative TVM concentrations. The carrier material showed no antibacterial effect. Conlusion: TVM showed the potential to penetrate through dentine and to inhibit bacterial growth. Therefore, it might have the potential to disinfect the outer root surface in perio-endo lesions, but further research is needed to confirm these observations. PMID:26966464

  17. The NASA/GEWEX Surface Radiation Budget Dataset

    NASA Astrophysics Data System (ADS)

    Gupta, Shashi; Stackhouse, Paul; Cox, Stephen; Mikovitz, Colleen; Zhang, Taiping

    The surface radiation budget (SRB), consisting of downward and upward components of shortwave (SW) and longwave (LW) radiation, is a major component of the energy exchanges between the atmosphere and land/ocean surfaces and thus affects surface temperature fields, fluxes of sensible and latent heat, and every aspect of energy and hydrological cycles. The NASA Global Energy and Water-cycle Experiment (GEWEX) SRB project has recently updated and improved a global dataset of surface radiative fluxes on a 1-degree grid for a 23-year period (July 1983 to June 2006). Both SW and LW fluxes have been produced with two sets of algorithms: one designated as primary and the other as quality-check. The primary algorithms use a more explicit treatment of surface and atmospheric processes while quality-check algorithms use a more parameterized approach. Cloud and surface properties for input to the algorithms have been derived from ISCCP pixel level (DX) data, temperature and humidity profiles from GEOS- 4 reanalysis products, and column ozone from a composite of TOMS, TOVS, and assimilated SBUV-2 datasets. Several top-of-atmosphere (TOA) radiation budget parameters have also been derived with the primary algorithms. Surface fluxes from all algorithms are extensively validated with ground-based measurements obtained from the Baseline Surface Radiation Network (BSRN), the Global Energy Balance Archive (GEBA), and the World Radiation Data Center (WRDC) archives. The SRB dataset is a major contributor to the GEWEX Radiative Flux Assessment activity. An overview of the latest version (Release-3.0) of the dataset with global and zonal statistics of fluxes, inferred cloud radiative forcing, and results of the validation activities will be presented. Time series of SRB parameters at the TOA and surface for global, land, ocean, and tropical area means will be presented along with analysis of flux anomalies related to El Nino/La Nina episodes, phases of North Atlantic Oscillation (NAO

  18. Trends in Surface Radiation Budgets at Climatic Time Scales

    NASA Astrophysics Data System (ADS)

    Pinker, R. T.; Zhang, B.; Ma, Y.

    2015-12-01

    For assessment of variability and trends in the Earth Radiation Balance, information is needed at climatic time scales. Satellite observations have been instrumental for advancing the understanding of radiative balance at global scale, however, the length of available satellite records is limited due to the frequent changes in the observing systems. In this paper we report on an effort to synthesize satellite observations from independent sources to estimates shortwave and longwave surface radiative fluxes at climatic time scales and use them to learn about their variability and trends at global scale with a focus on the tropics. An attempt will be made to learn from the comparison about possible causes of observed trends. The radiative fluxes were derived in the framework of the MEaSURES and NEWS programs; they are evaluated against ground observations and compared to independent satellite and model estimates. Attention is given to updated knowledge on radiative balance as compared to what is known from shorter time records.

  19. Trends in Surface Radiation Budgets at Climatic Time Scales

    NASA Astrophysics Data System (ADS)

    Pinker, Rachel T.; Zhang, Banglin; Ma, Yingtao

    2015-04-01

    For assessment of variability and trends in the Earth Radiation Balance, information is needed at climatic time scales. Satellite observations have been instrumental for advancing the understanding of the radiative balance at global scale, however, due to the frequent changes in the observing systems, the length of available satellite records is limited. In this paper we report on an effort to synthesize satellite observations from independent sources to estimates shortwave, longwave and spectral surface radiative fluxes at climatic time scales and use them to learn about their variability and trends. The radiative fluxes were derived in the framework of the MEaSURES and NEWS programs; they are evaluated against ground observations and compared to independent satellite and model estimates. Attention is given to updates on the radiative balance as compared to what is known from shorter time records and from models.

  20. Strong emission of terahertz radiation from nanostructured Ge surfaces

    SciTech Connect

    Kang, Chul; Maeng, Inhee; Kee, Chul-Sik; Leem, Jung Woo; Yu, Jae Su; Kim, Tae Heon; Lee, Jong Seok

    2015-06-29

    Indirect band gap semiconductors are not efficient emitters of terahertz radiation. Here, we report strong emission of terahertz radiation from germanium wafers with nanostructured surfaces. The amplitude of THz radiation from an array of nano-bullets (nano-cones) is more than five (three) times larger than that from a bare-Ge wafer. The power of the terahertz radiation from a Ge wafer with an array of nano-bullets is comparable to that from n-GaAs wafers, which have been widely used as a terahertz source. We find that the THz radiation from Ge wafers with the nano-bullets is even more powerful than that from n-GaAs for frequencies below 0.6 THz. Our results suggest that introducing properly designed nanostructures on indirect band gap semiconductor wafers is a simple and cheap method to improve the terahertz emission efficiency of the wafers significantly.

  1. A surface radiation climatology across two Meteosat satellite generations

    NASA Astrophysics Data System (ADS)

    Posselt, Rebekka; Müller, Richard; Trentmann, Jörg; Stöckli, Reto; Liniger, Mark A.

    2013-04-01

    Long term observations of the surface radiation budget are essential for climate monitoring, for climate model evaluation and for applications such as in the solar energy or agriculture sector. The Satellite Application Facility on Climate Monitoring (CM SAF) released a Climate Data Record (CDR) of global and direct surface irradiance as well as effective cloud albedo derived from observations of the Meteosat First Generation satellites (MFG, 1983-2005). We will present an extension of this CDR using measurements from the Meteosat Second Generation satellites (MSG, 2004-present). The differences in the spectral properties of the radiometers aboard the MFG and MSG satellites requires a modification of the original MagicSol algorithm. In order to guarantee a climatologically homogeneous continuation of MFG-based CDR, the two narrowband visible channels of the MSG satellites are combined to simulate the MFG broadband visible channel. The combination of the MFG and MSG based datasets is tested for homogeneity and no significant breaks are detected during the overlap period of 2004-2005. Validation of the extended global radiation dataset against ground based observations from the Baseline Surface Radiation Network yields a mean monthly absolute bias of 8.15 Wm-2. This complies to the target accuracy threshold of 15 Wm-2 (including a measurement uncertainty of the surface observations of 5 Wm-2) required for satellite-derived CDR's of global radiation by the Global Climate Observing System. Climatological analysis of the extended surface radiation dataset shows an overall positive trend of the global radiation for the Meteosat disc (with variable extents and significances for different regions) which can be attributed to a negative trend in the effective cloud albedo, i.e., a decrease in cloudiness. Trends due to changes in the clear sky radiation are small and only induced by trends in the water vapour fields. Trends caused by changes in the direct effects of

  2. Outgroup effects on root position and tree topology in the AFLP phylogeny of a rapidly radiating lineage of cichlid fish☆

    PubMed Central

    Kirchberger, Paul C.; Sefc, Kristina M.; Sturmbauer, Christian; Koblmüller, Stephan

    2014-01-01

    Phylogenetic analyses of rapid radiations are particularly challenging as short basal branches and incomplete lineage sorting complicate phylogenetic inference. Multilocus data of presence-absence polymorphisms such as obtained by AFLP genotyping overcome some of the difficulties, but also present their own intricacies. Here we analyze >1000 AFLP markers to address the evolutionary history of the Limnochromini, a cichlid fish lineage endemic to Lake Tanganyika, and to test for potential effects of outgroup composition on tree topology. The data support previous mitochondrial evidence on the tribe’s taxonomy by confirming the polyphyly of the genus Limnochromis and – in contradiction to a recent taxonomic revision – nesting the genus Greenwoodochromis within the Limnochromini. Species relationships suggest that ecological segregation occurred during the rapid basal radiation of the Limnochromini. The large phylogenetic distance between candidate outgroup taxa and the Limnochromini radiation caused random outgroup effects. Bootstrap support for ingroup nodes was lower in outgroup-rooted than in midpoint-rooted trees, and root positions and ingroup tree topologies varied in response to the composition of the outgroup. These observations suggest that the predisposition for homoplastic evolution makes AFLP-based phylogenetic analyses particularly susceptible to random biases introduced by too-distant outgroup taxa. PMID:24055738

  3. A Study of Surface Temperatures, Clouds and Net Radiation

    NASA Technical Reports Server (NTRS)

    Dhuria, Harbans

    1996-01-01

    This study focused on the seasonal relationships and interactions of climate parameters such as the surface temperatures, net radiation, long wave flux, short wave flux, and clouds on a global basis. Five years of observations (December 1984 to November 1989) from the Earth Radiation Budget Experiment (ERBE) and the International Satellite Cloud Climatology Program (ISCCP) were used to study both seasonal variations and interannual variations by use of a basic radiation budget equation. In addition, the study was extended to include an analysis of the cloud forcing due El-Nino's impact on the ERBE parameters.

  4. A study of surface temperatures, clouds and net radiation

    NASA Technical Reports Server (NTRS)

    Dhuria, Harbans

    1994-01-01

    The study is continuing and it is focused on examining seasonal relationships between climate parameters such as the surface temperatures, the net radiation and cloud types and amount on a global basis for the period February 1985 to January 1987. The study consists of an analysis of the combined Earth Radiation Budget Experiment (ERBE) and International Satellite Cloud Climatology Program (ISCCP) products. The main emphasis is on obtaining the information about the interactions and relationships of Earth Radiation Budget parameters, cloud and temperature information. The purpose is to gain additional qualitative and quantitative insight into the cloud climate relationship.

  5. Radiative decay of surface plasmons on nonspherical silver particles

    NASA Astrophysics Data System (ADS)

    Little, J. W.; Ferrell, T. L.; Callcott, T. A.; Arakawa, E. T.

    The radiation emitted by electron bombarded silver particles was studied. Electron micrographs have shown that the particles, obtained by heating thin (5 nm) silver films, were oblate (flattened) with minor axes aligned along the substrate normal. The characteristic wavelength obtained by bombarding these particles with 15 keV electrons was found to vary with angle of photon emission. This wavelength shift was modeled as a result of the mixture of radiation from dipole and quadrupole surface plasmon oscillations on oblate spheroids. Experimental observations of the energy, polarization, and angular distribution of the emitted radiation are in good agreement with theoretical calculations.

  6. Space radiation dose estimates on the surface of Mars.

    PubMed

    Simonsen, L C; Nealy, J E; Townsend, L W; Wilson, J W

    1990-01-01

    A future goal of the U.S. space program is a commitment to the manned exploration and habitation of Mars. An important consideration of such missions is the exposure of crew members to the damaging effects of ionizing radiation from high-energy galactic cosmic ray fluxes and solar proton flares. The crew will encounter the most harmful radiation environment in transit to Mars from which they must be adequately protected. However, once on the planet's surface, the Martian environment should provide a significant amount of protection from free-space radiative fluxes. In current Mars scenario descriptions, the crew flight time to Mars is estimated to be anywhere from 7 months to over a year each way, with stay times on the surface ranging from 20 days to 2 years. To maintain dose levels below established astronaut limits, dose estimates need to be determined for the entire mission length. With extended crew durations on the surface anticipated, the characterization of the Mars radiation environment is important in assessing all radiation protection requirements. This synopsis focuses on the probable doses incurred by surface inhabitants from the transport of galactic cosmic rays and solar protons through the Mars atmosphere. PMID:11537609

  7. Scanning electron microscopy of the root surface texture of extracted periodontally diseased teeth following various etching and chelating regimens.

    PubMed

    Bergenholtz, A; Babay, N

    1998-04-01

    Scanning electron microscopy of root surfaces that had been ultrasonically scaled and subjected to various conditioning regimens revealed the presence of two distinct types of cracks: extensive cracks, presumed to have been caused by drying before and during sputter-coating procedures; and smaller cracks that reflected the pattern of the irregular underlying dentin. Both etching and chelating agents appear to cause demineralization of the interfacial layer between cementum and dentin, causing a "peeling off" of cementum and exposure of the underlying dentin. The results suggest that burnishing the scaled root surface with either saline or any of the etching or chelating agents for at least 10 seconds, followed by soaking the cementum in 8% ethylenediaminetetraacetic acid for about 40 seconds, achieved a root surface that might be regarded as optimal for regeneration of periodontal tissues. PMID:9663095

  8. First global WCRP shortwave surface radiation budget dataset

    NASA Technical Reports Server (NTRS)

    Whitlock, C. H.; Charlock, T. P.; Staylor, W. F.; Pinker, R. T.; Laszlo, I.; Ohmura, A.; Gilgen, H.; Konzelman, T.; DiPasquale, R. C.; Moats, C. D.

    1995-01-01

    Shortwave radiative fluxes that reach the Earth's surface are key factors that influence atmospheric and oceanic circulations as well as surface climate. Yet, information on these fluxes is meager. Surface site data are generally available from only a limited number of observing stations over land. Much less is known about the large-scale variability of the shortwave radiative fluxes over the oceans, which cover most of the globe. Recognizing the need to produce global-scale fields of such fluxes for use in climate research, the World Climate Research Program has initiated activities that led to the establishment of the Surface Radiation Budget Climatology Project with the ultimate goal to determine various components of the surface radiation budget from satellite data. In this paper, the first global products that resulted from this activity are described. Monthly and daily data on a 280-km grid scale are available. Samples of climate parameters obtainable from the dataset are presented. Emphasis is given to validation and limitations of the results. For most of the globe, satellite estimates have bias values between +/- 20 W/sq m and rms values are around 25 W/sq m. There are specific regions with much larger uncertainties however.

  9. Surface radiation governs precipitation responses in transient and equilibrium climates

    NASA Astrophysics Data System (ADS)

    Sun, Shanshan; Moyer, Elisabeth

    2014-05-01

    Changes in radiative forcing are important not only for their impact on the Earth's temperature but also for their impact on the hydrological cycle. We show that model predictions of an amplified hydrological cycle under higher-CO2 conditions are well explained by changes in the surface energy budget: increased latent heat export largely balances increased downwelling longwave radiation, primarily due to increased humidity in a warmer atmosphere (see also Wild and Liepert 2010). We demonstrate that similar fundamental radiative adjustments govern global precipitation evolution across models, using twenty different GCMs in the Coupled Model Intercomparison Project phase 5 (CMIP5), purpose-run simulations with a fully-coupled GCM (CCSM3), and a simple one-column climate model (CliMT) with no cloud feedbacks but full representations of radiation, convection, turbulence, and surface ocean-atmosphere interaction. Physically understandable surface energy balance changes explain precipitation evolution in both equilibrium and transient climates (the well-documented 'fast' and 'slow' responses), in cases with different forcing agents (solar insolation and CO2), and in geo-engineering simulations where reduced shortwave forcing compensates for increased longwave opacity. We show that the enhancement in precipitation after an increase in radiative forcing is primarily due to the radiative effects of increased water vapor, which in turn produces the similarity in precipitation evolution in solar- and CO2-forced climates. We also show that differences in precipitation evolution between GCMs are due largely to differences in model shortwave feedbacks. The results of this study suggest that changes in the Earth's hydrological cycle under climate change can best be monitored and understood with surface measurements of longwave and shortwave fluxes, especially in the tropics and subtropics that account for the majority of the global moisture supply. References Wild, M. and B

  10. Surface plasmon amplification by stimulated emission of radiation (SPASER)

    DOEpatents

    Stockman, Mark I.; Bergman, David J.

    2009-08-04

    A nanostructure is used to generate a highly localized nanoscale optical field. The field is excited using surface plasmon amplification by stimulated emission of radiation (SPASER). The SPASER radiation consists of surface plasmons that undergo stimulated emission, but in contrast to photons can be localized within a nanoscale region. A SPASER can incorporate an active medium formed by two-level emitters, excited by an energy source, such as an optical, electrical, or chemical energy source. The active medium may be quantum dots, which transfer excitation energy by radiationless transitions to a resonant nanosystem that can play the same role as a laser cavity in a conventional laser. The transitions are stimulated by the surface plasmons in the nanostructure, causing the buildup of a macroscopic number of surface plasmons in a single mode.

  11. ENSO surface longwave radiation forcing over the tropical Pacific

    NASA Astrophysics Data System (ADS)

    Pavlakis, K. G.; Hatzidimitriou, D.; Drakakis, E.; Matsoukas, C.; Fotiadi, A.; Hatzianastassiou, N.; Vardavas, I.

    2006-12-01

    We have studied the spatial and temporal variation of the surface longwave radiation (downwelling and net) over a 21-year period in the tropical and subtropical Pacific Ocean (40 S-40 N, 90 E-75 W). The fluxes were computed using a deterministic model for atmospheric radiation transfer, along with satellite data from the ISCCP-D2 database and reanalysis data from NCEP/NCAR (acronyms explained in main text), for the key atmospheric and surface input parameters. An excellent correlation was found between the downwelling longwave radiation (DLR) anomaly and the Niño-3.4 index time-series, over the Niño-3.4 region located in the central Pacific. A high anti-correlation was also found over the western Pacific (15-0 S, 105-130 E). There is convincing evidence that the time series of the mean downwelling longwave radiation anomaly in the western Pacific precedes that in the Niño-3.4 region by 3-4 months. Thus, the downwelling longwave radiation anomaly is a complementary index to the SST anomaly for the study of ENSO events and can be used to asses whether or not El Niño or La Niña conditions prevail. Over the Niño-3.4 region, the mean DLR anomaly values range from +20 Wm-2 during El Niño episodes to -20 Wm-2 during La Niña events, while over the western Pacific (15-0 S, 105-130 E) these values range from -15 Wm-2 to +10 Wm-2, respectively. The long- term average (1984-2004) distribution of the net surface longwave radiation to the surface over the tropical and subtropical Pacific for the three month period November-December-January shows a net thermal cooling of the ocean surface. When El Niño conditions prevail, the thermal radiative cooling in the central and south-eastern tropical Pacific becomes weaker by 10 Wm-2 south of the equator in the central Pacific (7-0 S, 160-120 W) for the three-month period of NDJ, because the DLR increase is larger than the increase in surface thermal emission. In contrast

  12. Simultaneous Quantitative and Qualitative Analysis of Flavonoids from Ultraviolet-B Radiation in Leaves and Roots of Scutellaria baicalensis Georgi Using LC-UV-ESI-Q/TOF/MS.

    PubMed

    Tang, Wen-Ting; Fang, Min-Feng; Liu, Xiao; Yue, Ming

    2014-01-01

    Scutellaria baicalensis Georgi is one of the most widely used traditional Chinese herbal medicines. It has been used for anti-inflammatory, anticancer, antibacterial activities, and so forth. Long-term enhanced ultraviolet-B (UV-B) radiation caused more effect on leaves than on roots of the plant. Liquid chromatography-ultraviolet detection coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (LC-UV-ESI-Q/TOF/MS) method was applied for simultaneous quantitative and qualitative analysis of flavonoids in leaves and roots of S. baicalensis by enhanced UV-B radiation. Both low-intensity radiation and high-intensity radiation were not significantly increaseing the contents of baicalin, wogonoside, and wogonin in roots. However different intensity of radiation has different effects on several flavonoids in leaves. Both low-intensity radiation and high-intensity radiation had no significant effect on contents of baicalin and tectoridin in leaves; the content of scutellarin was significantly decreased by low-intensity radiation; chrysin was detected in low-intensity radiation and high-intensity radiation, and chrysin content is the highest in low-intensity radiation, but chrysin was not detected in control group. Different changes of different flavonoids under enhanced UV-B radiation indicate that induction on flavonoids is selective by enhanced UV-B radiation. PMID:24757579

  13. Shortwave spectral radiative forcing of cumulus clouds from surface observations

    NASA Astrophysics Data System (ADS)

    Kassianov, E.; Barnard, J.; Berg, L. K.; Long, C. N.; Flynn, C.

    2011-04-01

    The spectral changes of the shortwave total, direct and diffuse cloud radiative forcing (CRF) at surface are examined for the first time using spectrally resolved all-sky flux observations and clear-sky fluxes. The latter are computed applying a physically based approach, which accounts for the spectral changes of aerosol optical properties and surface albedo. Application of this approach to 13 summertime days with single-layer continental cumuli demonstrates: (i) the substantial contribution of the diffuse component to the total CRF, (ii) the well-defined spectral variations of total CRF in the visible spectral region, and (iii) the strong statistical relationship between spectral (500 nm) and shortwave broadband values of total CRF. Our results suggest that the framework based on the visible narrowband fluxes can provide important radiative quantities for rigorous evaluation of radiative transfer parameterizations and also can be applied for estimation of the shortwave broadband CRF.

  14. Surface Solar Radiation in North America: Observations, Reanalyses, Satellite and Derived Products

    NASA Astrophysics Data System (ADS)

    Slater, A. G.

    2015-12-01

    Observations of daily surface solar/shortwave radiation data from over 4000 stations have been gathered, covering much of the lower 48 continental states of the US as well as portions of Alberta and British Columbia, Canada. The quantity of data increases almost linearly from 1998 when only several hundred stations had data. A quality control procedure utilizing threshold values along with computing the clear sky radiation envelope for individual stations was implemented to both screen bad data and rescue informative data. Over two thirds of the observations are seen as acceptable. Fifteen different surface solar radiation products are assessed relative to observations, including reanalyses (20thC, CFSRR, ERAI, JRA-55, MERRA, NARR, NCEP), derived products (CRU_NCEP, DAYMET, GLDAS, GSWP3, MsTMIP, NLDAS) and two satellite products (CERES and GOES). All except the CERES product are daily or finer in temporal resolution. The root mean square error of spatial biases is greater than 18Wm-2 for 13 of the 15 products over the summer season (June, July, August). None of the daily resolution products fulfill all three desirable criteria of low (<5%) annual or seasonal bias, high correlation with observed cloudiness and correct distribution of clear sky radiation. Some products display vestiges of underlying algorithm issues (e.g. from MTCLIM ver4.3) or bias correction methods. A new bias correction method is introduced that preserves clear sky radiation values and better replicates cloudiness statistics. The current quantity of data over the continental US suggests a solar radiation product based on, or enhanced with, observations is feasible.

  15. Evaluation of surface energy and radiation balance systems for FIFE

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.; Qian, Ping

    1988-01-01

    The energy balance and radiation balance components were determined at six sites during the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) conducted south of Manhattan, Kansas during the summer of 1987. The objectives were: to determine the effect of slope and aspect, throughout a growing season, on the magnitude of the surface energy balance fluxes as determined by the Energy Balance Method (EBM); to investigate the calculation of the soil heat flux density at the surface as calculated from the heat capacity and the thermal conductivity equations; and to evaluate the performance of the Surface Energy and Radiation Balance System (SERBS). A total of 17 variables were monitored at each site. They included net, solar (up and down), total hemispherical (up and down), and diffuse radiation, soil temperature and heat flux density, air and wet bulb temperature gradients, wind speed and direction, and precipitation. A preliminary analysis of the data, for the season, indicate that variables including net radiation, air temperature, vapor pressure, and wind speed were quite similar at the sites even though the sites were as much as 16 km apart and represented four cardinal slopes and the top of a ridge.

  16. The NOAA Integrated Surface Irradiance Study (ISIS) - A new surface radiation monitoring program

    SciTech Connect

    Hicks, B.B.; DeLuisi, J.J.

    1996-12-01

    This paper describes a new radiation monitoring program, the Integrated Surface Irradiance Study (ISIS), that builds upon and takes over from earlier NOAA networks monitoring components of solar radiation [both the visible component (SOLRAD) and the shortwave component that causes sunburn, UV-B] across the continental United States. ISIS is implemented in two levels. Level 1 addresses incoming radiation only, and level 2 addresses the surface radiation balance. Level 2 also constitutes the SURFRAD (Surface Radiation) program of the NOAA Office of Global Programs, specifically intended to provide radiation data to support large-scale hydrologic studies that will be conducted under the Global Energy and Water Cycle Experiment. Eventually, it is planned for level 2 sites to monitor all components of the surface energy balance. Both levels of ISIS will eventually measure both visible and UV radiation components. At present, there are nine sites that are considered to be at ISIS level 1 standard and an additional four level 2 SURFRAD sites. A 10th level 1 site will be in operation soon. Plans call for an increase in the number of sites of both kinds, up to about 15 ISIS sites, of which 6 will be at the SURFRAD level. 20 refs., 2 figs., 1 tab.

  17. Ultraviolet Radiation-induced Alteration of Martian Surface Materials

    NASA Technical Reports Server (NTRS)

    Yen, A. S.

    1999-01-01

    The nature and origin of martian surface materials cannot be fully characterized without addressing the unusual reactivity of the soil and the effects of exposure to the unique martian environment. Our laboratory experiments show that ultraviolet radiation at the martian surface can result in the oxidation of metal atoms and the creation of reactive oxygen species on grain surfaces. This process is important in understanding the nature and evolution of martian soils. It can explain the reactivity discovered by the Viking Landers and possibly the origin of the ferric component of the soil.

  18. Effect of power settings versus temperature change at the root surface when using multiple fiber sizes with a Holmium YAG laser while enlarging a root canal.

    PubMed

    Cohen, B I; Deutsch, A S; Musikant, B L; Pagnillo, M K

    1998-12-01

    The aim of this study was to determine if there is an increase in temperature at the root surface as the canal is enlarged when using a Holmium:YAG laser. An increase might be expected because, as the canal is enlarged, there is less dentin between the canal walls and the outer cementum surface of the root to absorb the heat. Sixty single-rooted human teeth were randomly assigned to 1 of 3 groups according to laser power settings: 0.50, 0.75, and 1.00 W. Each tooth in each power group was subjected to lasing using fiber sizes of 140, 245, 355, and 410 microns. The dependent variables in these analyses included: (a) change in temperature, measured with T-type thermocouples placed 2 mm from the coronal and apical ends of the root; (b) depth of laser in the tooth; (c) depth that a conventional fiber could be inserted after lasing; and (d) tooth physical dimensions. ANOVA for coronal temperature showed no interaction between fibers and power settings. Repeated-measures ANOVA for apical temperature showed a significant difference between fibers, but not between power settings. No interaction between fibers and power settings was observed. For the depth of tooth during lasing (how far the fiberoptic guide penetrated into the tooth), no interaction between fibers and power settings was observed. Pairwise contrasts revealed that all fibers were different from one another, with depth decreasing as fiber size increased. Depth files could be inserted that showed the depth significantly decreased as file size increased from 50 through 70. ANOVAs illustrated that there were no significant differences between power settings for any of the five tooth physical dimensions. All temperature differences observed apically and coronally were between 0 degree to 10 degrees C, with the majority (> 98%) being between 0 degree to 5 degrees C. After lasing with the 410-micron fiber, the root canals were widened to at least 45 or 50 K-files (450 or 500 microns). However, by using a 410-micron

  19. ENSO surface longwave radiation forcing over the tropical Pacific

    NASA Astrophysics Data System (ADS)

    Pavlakis, K. G.; Hatzidimitriou, D.; Drakakis, E.; Matsoukas, C.; Fotiadi, A.; Hatzianastassiou, N.; Vardavas, I.

    2007-04-01

    We have studied the spatial and temporal variation of the surface longwave radiation (downwelling and net) over a 21-year period in the tropical and subtropical Pacific Ocean (40 S-40 N, 90 E-75 W). The fluxes were computed using a deterministic model for atmospheric radiation transfer, along with satellite data from the ISCCP-D2 database and reanalysis data from NCEP/NCAR (acronyms explained in main text), for the key atmospheric and surface input parameters. An excellent correlation was found between the downwelling longwave radiation (DLR) anomaly and the Niño-3.4 index time-series, over the Niño-3.4 region located in the central Pacific. A high anti-correlation was also found over the western Pacific (15-0 S, 105-130 E). There is convincing evidence that the time series of the mean downwelling longwave radiation anomaly in the western Pacific precedes that in the Niño-3.4 region by 3-4 months. Thus, the downwelling longwave radiation anomaly is a complementary index to the SST anomaly for the study of ENSO events and can be used to asses whether or not El Niño or La Niña conditions prevail. Over the Niño-3.4 region, the mean DLR anomaly values range from +20 Wm-2 during El Niño episodes to -20 Wm-2 during La Niña events, while over the western Pacific (15-0 S, 105-130 E) these values range from -15 Wm-2 to +10 Wm-2, respectively. The long- term average (1984-2004) distribution of the net downwelling longwave radiation at the surface over the tropical and subtropical Pacific for the three month period November-December-January shows a net thermal cooling of the ocean surface. When El Niño conditions prevail, the thermal radiative cooling in the central and south-eastern tropical Pacific becomes weaker by 10 Wm-2 south of the equator in the central Pacific (7-0 S, 160-120 W) for the three-month period of NDJ, because the DLR increase is larger than the increase in surface thermal emission. In contrast

  20. Parameterisation of incoming longwave radiation over glacier surfaces in the semiarid Andes of Chile

    NASA Astrophysics Data System (ADS)

    MacDonell, Shelley; Nicholson, Lindsey; Kinnard, Christophe

    2013-02-01

    A good understanding of radiation fluxes is important for calculating energy, and hence, mass exchange at glacier surfaces. This study evaluates incoming longwave radiation measured at two nearby glacier stations in the high Andes of the Norte Chico region of Chile. These data are the first published records of atmospheric longwave radiation measurements in this region. Nine previously published optimised parameterisations for clear sky emissivity all produced results with a root mean square error (RMSE) ~20 W m-2 and bias within ±5 W m-2, which is inline with findings from other regions. Six optimised parameterisations for incoming longwave in all sky conditions were trialled for application to this site, five of which performed comparably well with RMSE on daytime data <18 W m-2 and bias within ±6 W m-2 when applied to the optimisation site and RMSE <20 W m-2 and bias within ±10 W m-2 when applied to the validation site. The parameterisation proposed by Mölg et al. (J Glaciol 55:292-302, 2009) was selected for use in this region. Incorporating the proposed elevation modification into the equation reduced the bias in the modelled incoming longwave radiation for the validation site. It was found that applying the parameterisation optimised in the original work at Kilimanjaro produced good results at both the primary and validation site in this study, suggesting that this formulation may be robust for different high mountain regions.

  1. Changes in biologically active ultraviolet radiation reaching the Earth's surface.

    PubMed

    Madronich, S; McKenzie, R L; Björn, L O; Caldwell, M M

    1998-10-01

    Stratospheric ozone levels are near their lowest point since measurements began, so current ultraviolet-B (UV-B) radiation levels are thought to be close to their maximum. Total stratospheric content of ozone-depleting substances is expected to reach a maximum before the year 2000. All other things being equal, the current ozone losses and related UV-B increases should be close to their maximum. Increases in surface erythemal (sunburning) UV radiation relative to the values in the 1970s are estimated to be: about 7% at Northern Hemisphere mid-latitudes in winter/spring; about 4% at Northern Hemisphere mid-latitudes in summer/fall; about 6% at Southern Hemisphere mid-latitudes on a year-round basis; about 130% in the Antarctic in spring; and about 22% in the Arctic in spring. Reductions in atmospheric ozone are expected to result in higher amounts of UV-B radiation reaching the Earth's surface. The expected correlation between increases in surface UV-B radiation and decreases in overhead ozone has been further demonstrated and quantified by ground-based instruments under a wide range of conditions. Improved measurements of UV-B radiation are now providing better geographical and temporal coverage. Surface UV-B radiation levels are highly variable because of cloud cover, and also because of local effects including pollutants and surface reflections. These factors usually decrease atmospheric transmission and therefore the surface irradiances at UV-B as well as other wavelengths. Occasional cloud-induced increases have also been reported. With a few exceptions, the direct detection of UV-B trends at low- and mid-latitudes remains problematic due to this high natural variability, the relatively small ozone changes, and the practical difficulties of maintaining long-term stability in networks of UV-measuring instruments. Few reliable UV-B radiation measurements are available from pre-ozone-depletion days. Satellite-based observations of atmospheric ozone and clouds are

  2. Effect of Citric Acid and Ethylenediaminetetraacetic Acid on the Surface Morphology of Young and Old Root Dentin

    PubMed Central

    Scelza, Miriam Zaccaro; de Noronha, Fernando; da Silva, Licinio Esmeraldo; Maurício, Marcos; Gallito, Marco Antonio; Scelza, Pantaleo

    2016-01-01

    Introduction: The aim of this in vitro study was to evaluate the effect of 10% citric acid and 17% ethylenediaminetetraacetic acid (EDTA) irrigating solutions on the surface morphology of young and old root dentin by determining the number and diameter of dentinal tubules using scanning electron microscopy (SEM). Methods and Materials: Fifty healthy human teeth collected from young (≤30 years) and old (≥60 years) individuals (n=25) were first prepared with a Largo bur #2 to produce smear layer on the root canal surface. Subsequently, the crowns and the root middle and apical thirds were sectioned and removed, and the cervical thirds were sectioned vertically in the buccal-lingual direction into two equal halves. The obtained samples were then immersed in 2.5% sodium hypochlorite for 30 min and randomly separated into two treatment groups for each age group. In each age group, ten samples were selected as controls and did not receive any type of treatment. The rest of the specimens were then rinsed, dried and treated for 4 min with 10% citric acid or 17% EDTA. The samples were then assessed with SEM regarding the number and diameter of dentinal tubules. All data were assessed using Student’s t-test. The level of significance was set at 0.05. Results: Regardless of the type of treatment, no significant differences were observed in the number of open tubules between the young and old root dentin (P>0.05). Nonetheless, the diameter of the tubules in the old root dentin was larger when 17% EDTA was used (P<0.05). Both, young and old root dentin did not differ with the 10% citric acid treatment (P>0.05). Conclusion: The results showed that 17% EDTA treatment induced a significant demineralization in old root dentin. PMID:27471529

  3. DELAYED TOOTH REPLANTATION AFTER ROOT SURFACE TREATMENT WITH SODIUM HYPOCHLORITE AND SODIUM FLUORIDE: HISTOMORPHOMETRIC ANALYSIS IN RATS

    PubMed Central

    Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

    2006-01-01

    In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin-embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other. PMID:19089038

  4. Simulation and Comparison of Martian Surface Ionization Radiation

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Zeitlin, Cary; Hassler, Donald M.; Cucinotta, Francis A.

    2013-01-01

    The spectrum of energetic particle radiation and corresponding doses at the surface of Mars is being characterized by the Radiation Assessment Detector (RAD), one of ten science instruments on the Mars Science Laboratory (MSL) Curiosity Rover. The time series of dose rate for the first 300 Sols after landing on Mars on August 6, 2012 is presented here. For the comparison to RAD measurements of dose rate, Martian surface ionization radiation is simulated by utilizing observed space quantities. The GCR primary radiation spectrum is calculated by using the Badhwar-O'Neill 2011 (BO11) galactic cosmic ray (GCR) model, which has been developed by utilizing all balloon and satellite GCR measurements since 1955 and the newer 1997-2012 Advanced Composition Explorer (ACE) measurements. In the BO11 model, solar modulation of the GCR primary radiation spectrum is described in terms of the international smoothed sunspot number and a time delay function. For the transport of the impingent GCR primary radiation through Mars atmosphere, a vertical distribution of atmospheric thickness at each elevation is calculated using the vertical profiles of atmospheric temperature and pressure made by Mars Global Surveyor measurements. At Gale Crater in the southern hemisphere, the seasonal variation of atmospheric thickness is accounted for the daily atmospheric pressure measurements of the MSL Rover Environmental Monitoring Station (REMS) by using low- and high-density models for cool- and warm-season, respectively. The spherically distributed atmospheric distance is traced along the slant path, and the resultant directional shielding by Martian atmosphere is coupled with Curiosity vehicle for dose estimates. We present predictions of dose rate and comparison to the RAD measurements. The simulation agrees to within +/- 20% with the RAD measurements showing clearly the variation of dose rate by heliospheric conditions, and presenting the sensitivity of dose rate by atmospheric pressure

  5. Mutations in Arabidopsis thaliana genes involved in the tryptophan biosynthesis pathway affect root waving on tilted agar surfaces

    NASA Technical Reports Server (NTRS)

    Rutherford, R.; Gallois, P.; Masson, P. H.

    1998-01-01

    Arabidopsis thaliana roots grow in a wavy pattern upon a slanted surface. A novel mutation in the anthranilate synthase alpha 1 (ASA1) gene, named trp5-2wvc1, and mutations in the tryptophan synthase alpha and beta 1 genes (trp3-1 and trp2-1, respectively) confer a compressed root wave phenotype on tilted agar surfaces. When trp5-2wvc1 seedlings are grown on media supplemented with anthranilate metabolites, their roots wave like wild type. Genetic and pharmacological experiments argue that the compressed root wave phenotypes of trp5-2wvc1, trp2-1 and trp3-1 seedlings are not due to reduced IAA biosynthetic potential, but rather to a deficiency in L-tryptophan (L-Trp), or in a L-Trp derivative. Although the roots of 7-day-old seedlings possess higher concentrations of free L-Trp than the shoot as a whole, trp5-2wvc1 mutants show no detectable alteration in L-Trp levels in either tissue type, suggesting that a very localized shortage of L-Trp, or of a L-Trp-derived compound, is responsible for the observed phenotype.

  6. Effect of surface treatments on radiation buildup in steam generators

    SciTech Connect

    Not Available

    1991-11-01

    A study of the effect of surface preparation on the radiation buildup of steam generator materials of construction was conducted. The tests consisted of exposing treated manway seal plates to primary reactor coolant during the second through the fifth fuel cycle of the Chinon B1 pressurized water reactor. The pretreatments included: mechanical polishing, electropolishing (either on the as received surface or on a surface which had been previously mechanically polished), and passivation via the RCT (laboratory) process or the Framatome (in situ) process. Radioactivity buildup was determined at the end of each fuel cycle. A selected number of the seal plates were removed from the steam generators after each exposure cycle for destructive examinations. The electropolished surfaces exhibited a significantly lower radioactive buildup rate; an average factor of five less buildup compared to an as-received surface. Passivation of the electropolished surface, especially via the RCT process, reduced the buildup rate still further by a factor of two over the electropolished-only surface. Examination of the surfaces by profilometry, scanning electron microscopy, etc., after exposure indicated no detrimental effects on the surface characteristics attributable to the surface treatments. A program has now been instituted to electropolish the steam generator channel heads of all new reactors in France, as well as the steam generators intended for replacement in existing plants. 1 ref., 5 figs., 10 tabs.

  7. [In vivo study of bacterial invasion in root planed and citric acid treated radicular surfaces of periodontally involved human teeth].

    PubMed

    Ito, K; Arai, N; Otogoto, J; Murai, S

    1989-06-01

    The purpose of this study was to investigate whether plaque bacteria invade the exposed radicular dentin after root planing or chemical root treatment in vivo. Eighteen caries-free human periodontally involved teeth with hopeless prognoses were studied. Fourteen teeth were scaled and root planed with hand curette type scalers. The proximal surface of each treated tooth was designated as the RP surface. The remaining half of the proximal surface was treated with citric acid (pH 1.0) for 3 minutes and was designated as the CA surface. Four untreated teeth served as controls. After 4 weeks, the teeth were extracted, and were processed for light microscopy and for scanning electron microscopy concerning bacterial invasion into the supragingival radicular dentin. The following results were obtained. 1. Radicular cementum was present on most untreated tooth surfaces. However, bacteria were never seen in the dentinal tubules. 2. Bacterial invasion into the dentinal tubules was observed in five of the 10 proximal surfaces (50% of the RP surfaces) and in nine of the 10 proximal surfaces (90% of the CA surfaces). 3. The depth (9.5 +/- 24.1 microns vs 84.6 +/- 136.3 microns) and percentage (0.8 +/- 2.1% vs 20.3 +/- 17.3%) of bacterial invasion in the dentinal tubules of the RP surfaces was lower than that of the CA surfaces. 4. Cocci and short rods were present in the supragingival dentinal tubules. 5. Since CA surfaces may accelerate bacterial invasion the citric acid treatment might be harmful in patients with inadequate plaque control. PMID:2700200

  8. Aeolian removal of dust from radiator surfaces on Mars

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Perez-Davis, Marla E.; Rutledge, Sharon K.; Hotes, Deborah

    1990-01-01

    Simulated radiator surfaces made of arc-textured Cu and Nb-1 percent-Zr and ion beam textured graphite and C-C composite were fabricated and their integrated spectral emittance characterized from 300 to 3000 K. A thin layer of aluminum oxide, basalt, or iron (III) oxide dust was then deposited on them, and they were subjected to low pressure winds in the Martian Surface Wind Tunnel. It was found that dust deposited on simulated radiator surfaces may or may not seriously lower their integrated spectral emittance, depending upon the characteristics of the dust. With Al2O3 there is no appreciable degradation of emittance on a dusted sample, with basaltic dust there is a 10 to 20 percent degradation, and with Fe2O3 a 20 to 40 percent degradation. It was also found that very high winds on dusted highly textured surfaces can result in their abrasion. Degradation in emittance due to abrasion was found to vary with radiator material. Arc-textured Cu and Nb-1 percent Zr was found to be more susceptible to emittance degradation than graphite or C-C composite. The most abrasion occurred at low angles, peaking at the 22.5 deg test samples.

  9. Aeolian removal of dust from radiator surfaces on Mars

    SciTech Connect

    Gaier, J.R.; Perez-Davis, M.E.; Rutledge, S.K.; Hotes, D.

    1994-09-01

    Simulated radiator surfaces made of arc-textured copper and niobium-one percent-zirconium, and ion beam textured graphite and carbon-carbon composite were fabricated and their integrated spectral emittance characterized from 300 to 3000 K. A thin layer of aluminum oxide, basalt, or iron (III) oxide dust was then deposited on them, and they were subjected to low pressure winds in the Martian Surface Wind Tunnel. It has been found that dust deposited on simulated radiator surfaces may or may not seriously lower their integrated spectral emittance, depending upon the characteristics of the dust. With Al{sub 2}O{sub 3} there is no appreciable degradation of emittance on a dusted sample, with basaltic dust there is a 10-20 percent degradation, and with Fe{sub 2}O{sub 3} a 20-40 percent degradation. It was also found that very high winds on dusted highly textured surfaces can result in their abrasion. Degradation in emittance due to abrasion was found to vary with radiator material. Arc-textured copper and Nb-1%Zr was found to be more susceptible to emittance degradation than graphite or carbon-carbon composite. The most abrasion occurred at low angles, peaking at the 22.5{degrees} test samples.

  10. Healing of periodontal defects treated with enamel matrix proteins and root surface conditioning--an experimental study in dogs.

    PubMed

    Sakallioğlu, Umur; Açikgöz, Gökhan; Ayas, Bülent; Kirtiloğlu, Tuğrul; Sakallioğlu, Eser

    2004-05-01

    Application of enamel matrix proteins has been introduced as an alternative method for periodontal regenerative therapy. It is claimed that this approach provides periodontal regeneration by a biological approach, i.e. creating a matrix on the root surfaces that promotes cementum, periodontal ligament (PDL) and alveolar bone regeneration, thus mimicking the events occurring during tooth development. Although there have been numerous in vitro and in vivo studies demonstrating periodontal regeneration, acellular cementum formation and clinical outcomes via enamel matrix proteins usage, their effects on the healing pattern of soft and hard periodontal tissues are not well-established and compared with root conditioning alone. In the present study, the effects of Emdogain (Biora, Malmö, Sweden), an enamel matrix derivative mainly composed of enamel matrix proteins (test), on periodontal wound healing were evaluated and compared with root surface conditioning (performed with 36% orthophosphoric acid) alone (control) histopathologically and histomorphometrically by means of the soft and hard tissue profile of periodontium. An experimental periodontitis model performed at premolar teeth of four dogs were used in the study and the healing pattern of periodontal tissues was evaluated at days 7, 14, 21, 28 (one dog at each day), respectively. At day 7, soft tissue attachment evaluated by means of connective tissue and/or epithelial attachment to the root surfaces revealed higher connective tissue attachment rate in the test group and the amount of new connective tissue proliferation in the test group was significantly greater than the control group (p<0.01). New bone formation by osteoconduction initiated at day 14 in the test and control group. At day 21, the orientation of supra-alveolar and PDL fibers established, and new cementum formation observed in both groups. At day 28, although regenerated cementum was cellular in all of the roots in the control samples, an

  11. Mars Surface Ionizing Radiation Environment: Need for Validation

    NASA Astrophysics Data System (ADS)

    Wilson, J. W.; Kim, M. Y.; Clowdsley, M. S.; Heinbockel, J. H.; Tripathi, R. K.; Singleterry, R. C.; Shinn, J. L.; Suggs, R.

    1999-01-01

    Protection against the hazards from exposure to ionizing radiation remains an unresolved issue in the Human Exploration and Development of Space (HEDS) enterprise [1]. The major uncertainty is the lack of data on biological response to galactic cosmic ray (GCR) exposures but even a full understanding of the physical interaction of GCR with shielding and body tissues is not yet available and has a potentially large impact on mission costs. "The general opinion is that the initial flights should be short-stay missions performed as fast as possible (so-called 'Sprint' missions) to minimize crew exposure to the zero-g and space radiation environment, to ease requirements on system reliability, and to enhance the probability of mission success." The short-stay missions tend to have long transit times and may not be the best option due to the relatively long exposure to zero-g and ionizing radiation. On the other hand the short-transit missions tend to have long stays on the surface requiring an adequate knowledge of the surface radiation environment to estimate risks and to design shield configurations. Our knowledge of the surface environment is theoretically based and suffers from an incomplete understanding of the physical interactions of GCR with the Martian atmosphere, Martian surface, and intervening shield materials. An important component of Mars surface robotic exploration is the opportunity to test our understanding of the Mars surface environment. The Mars surface environment is generated by the interaction of Galactic Cosmic Rays (GCR) and Solar Particle Events (SPEs) with the Mars atmosphere and Mars surface materials. In these interactions, multiple charged ions are reduced in size and secondary particles are generated, including neutrons. Upon impact with the Martian surface, the character of the interactions changes as a result of the differing nuclear constituents of the surface materials. Among the surface environment are many neutrons diffusing from

  12. Surface shortwave aerosol radiative forcing during the Atmospheric Radiation Measurement Mobile Facility deployment in Niamey, Niger

    SciTech Connect

    McFarlane, Sally A.; Kassianov, Evgueni I.; Barnard, James C.; Flynn, Connor J.; Ackerman, Thomas P.

    2009-03-18

    This study presents ground-based remote sensing measurements of aerosol optical properties and corresponding shortwave surface radiative effect calculations for the deployment of the Atmospheric Radiation Measurement (ARM) Program’s Mobile Facility (AMF) to Niamey, Niger during 2006. Aerosol optical properties including aerosol optical depth (AOD), single scattering albedo (SSA), and asymmetry parameter (AP) were derived from multi-filter rotating shadowband radiometer (MFRSR) measurements during the two dry seasons (Jan-Apr and Oct-Dec) at Niamey. The vertical distribution of aerosol extinction was derived from the collocated micropulse lidar (MPL). The aerosol optical properties and vertical distribution of extinction varied significantly throughout the year, with higher AOD, lower SSA, and deeper aerosol layers during the Jan-Apr time period, when biomass burning aerosol layers were more frequent. Using the retrieved aerosol properties and vertical extinction profiles, broadband shortwave surface fluxes and atmospheric heating rate profiles were calculated. Corresponding calculations with no aerosol were used to estimate the aerosol direct radiative effect at the surface. Comparison of the calculated surface fluxes to observed fluxes for non-cloudy periods indicated that the remote sensing retrievals provided a reasonable estimation of the optical properties, with mean differences between calculated and observed fluxes of less than 5 W/m2 and RMS differences less than 25 W/m2. Sensitivity tests for a particular case study showed that the observed fluxes could be matched with variations of < 10% in the inputs to the radiative transfer model. We estimated the daily-averaged aerosol radiative effect at the surface by subtracting the clear calculations from the aerosol calculations. The average daily SW aerosol radiative effect over the study period was -27 W/m2, which is comparable to values estimated from satellite data and from climate models with sophisticated

  13. Dentin Morphology of Root Canal Surface: A Quantitative Evaluation Based on a Scanning Electronic Microscopy Study

    PubMed Central

    Lo Giudice, Giuseppe; Cutroneo, Giuseppina; Centofanti, Antonio; Artemisia, Alessandro; Bramanti, Ennio; Militi, Angela; Rizzo, Giuseppina; Favaloro, Angelo; Irrera, Alessia; Lo Giudice, Roberto; Cicciù, Marco

    2015-01-01

    Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm) than the middle zone (3.74 μm) and the apical zone (1.73 μm). The average number of dentinal tubules (in an area of 1 mm2) was similar in coronal zone (46,798 ± 10,644) and apical zone (45,192 ± 10,888), while in the middle zone they were lower in number (30,940 ± 7,651). However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system. PMID:26413504

  14. Rhizophagus irregularis MUCL 41833 can colonize and improve P uptake of Plantago lanceolata after exposure to ionizing gamma radiation in root organ culture.

    PubMed

    Kothamasi, David; Wannijn, Jean; van Hees, May; Nauts, Robin; van Gompel, Axel; Vanhoudt, Nathalie; Cranenbrouck, Sylvie; Declerck, Stéphane; Vandenhove, Hildegarde

    2016-04-01

    Long-lived radionuclides such as (90)Sr and (137)Cs can be naturally or accidentally deposited in the upper soil layers where they emit β/γ radiation. Previous studies have shown that arbuscular mycorrhizal fungi (AMF) can accumulate and transfer radionuclides from soil to plant, but there have been no studies on the direct impact of ionizing radiation on AMF. In this study, root organ cultures of the AMF Rhizophagus irregularis MUCL 41833 were exposed to 15.37, 30.35, and 113.03 Gy gamma radiation from a (137)Cs source. Exposed spores were subsequently inoculated to Plantago lanceolata seedlings in pots, and root colonization and P uptake evaluated. P. lanceolata seedlings inoculated with non-irradiated AMF spores or with spores irradiated with up to 30.35 Gy gamma radiation had similar levels of root colonization. Spores irradiated with 113.03 Gy gamma radiation failed to colonize P. lanceolata roots. P content of plants inoculated with non-irradiated spores or of plants inoculated with spores irradiated with up to 30.35 Gy gamma radiation was higher than in non-mycorrhizal plants or plants inoculated with spores irradiated with 113.03 Gy gamma radiation. These results demonstrate that spores of R. irregularis MUCL 41833 are tolerant to chronic ionizing radiation at high doses. PMID:26467250

  15. Clouds, surface temperature, and the tropical and subtropical radiation budget

    NASA Technical Reports Server (NTRS)

    Dhuria, Harbans L.; Kyle, H. Lee

    1980-01-01

    Solar energy drives both the Earth's climate and biosphere, but the absorbed energy is unevenly distributed over the Earth. The tropical regions receive excess energy which is then transported by atmospheric and ocean currents to the higher latitudes. All regions at a given latitude receive the same top of the atmosphere solar irradiance (insolation). However, the net radiation received from the Sun in the tropics and subtropics varies greatly from one region to another depending on local conditions. Over land, variations in surface albedo are important. Over both land and ocean, surface temperature, cloud amount, and cloud type are also important. The Nimbus-7 cloud and Earth radiation budget (ERB) data sets are used to examine the affect of these parameters.

  16. SALTS AND RADIATION PRODUCTS ON THE SURFACE OF EUROPA

    SciTech Connect

    Brown, M. E.; Hand, K. P.

    2013-04-15

    The surface of Europa could contain the compositional imprint of an underlying interior ocean, but competing hypotheses differ over whether spectral observations from the Galileo spacecraft show the signature of ocean evaporates or simply surface radiation products unrelated to the interior. Using adaptive optics at the W. M. Keck Observatory, we have obtained spatially resolved spectra of most of the disk of Europa at a spectral resolution {approx}40 times higher than seen by the Galileo spacecraft. These spectra show a previously undetected distinct signature of magnesium sulfate salts on Europa, but the magnesium sulfate is confined to the trailing hemisphere and spatially correlated with the presence of radiation products like sulfuric acid and SO{sub 2}. On the leading, less irradiated, hemisphere, our observations rule out the presence of many of the proposed sulfate salts, but do show the presence of distorted water ice bands. Based on the association of the potential MgSO{sub 4} detection on the trailing side with other radiation products, we conclude that MgSO{sub 4} is also a radiation product, rather than a constituent of a Europa ocean brine. Based on ocean chemistry models, we hypothesize that, prior to irradiation, magnesium is primarily in the form of MgCl{sub 2}, and we predict that NaCl and KCl are even more abundant, and, in fact, dominate the non-ice component of the leading hemisphere. We propose observational tests of this new hypothesis.

  17. Influence of Solar Radiation Pressure on Satellite Surfaces

    NASA Astrophysics Data System (ADS)

    Kigel, Maryna; Bremer, Stefanie; List, Meike; Rievers, Benny; Rievers, Benny

    In its orbit the satellite's motion is affected by several environmental disturbances. One of these disturbing effects is the solar radiation pressure, which can be modeled adequately by assuming that incident radiation is absorbed, reflected specularly or/and reflected diffuse. At the German institute ZARM (Center of Applied Space Technology and Microgravity) an al-gorithm for the determination of resulting disturbance forces and torques due to solar radiation pressure has been developed. The source code has been tested and compared with analytically obtained values, results will be presented. Since the solar radiation pressure will be considered in the disturbance analysis of the small satellite mission MICROSCOPE, an accurate modelling of the resulting effects is necessary. Thus the algorithm has to be considered for the end-to-end simulation of this mission anyway. For these purposes a finite element model (FEM) of the MICROSCOPE satellite's surfaces structure is built, geometry and surface properties are taken from this model. First results of this study will be reported.

  18. Salts and Radiation Products on the Surface of Europa

    NASA Astrophysics Data System (ADS)

    Brown, M. E.; Hand, K. P.

    2013-04-01

    The surface of Europa could contain the compositional imprint of an underlying interior ocean, but competing hypotheses differ over whether spectral observations from the Galileo spacecraft show the signature of ocean evaporates or simply surface radiation products unrelated to the interior. Using adaptive optics at the W. M. Keck Observatory, we have obtained spatially resolved spectra of most of the disk of Europa at a spectral resolution ∼40 times higher than seen by the Galileo spacecraft. These spectra show a previously undetected distinct signature of magnesium sulfate salts on Europa, but the magnesium sulfate is confined to the trailing hemisphere and spatially correlated with the presence of radiation products like sulfuric acid and SO2. On the leading, less irradiated, hemisphere, our observations rule out the presence of many of the proposed sulfate salts, but do show the presence of distorted water ice bands. Based on the association of the potential MgSO4 detection on the trailing side with other radiation products, we conclude that MgSO4 is also a radiation product, rather than a constituent of a Europa ocean brine. Based on ocean chemistry models, we hypothesize that, prior to irradiation, magnesium is primarily in the form of MgCl2, and we predict that NaCl and KCl are even more abundant, and, in fact, dominate the non-ice component of the leading hemisphere. We propose observational tests of this new hypothesis.

  19. Radiation shielding in transit to Mars and on the surface

    NASA Technical Reports Server (NTRS)

    Conway, Edmund J.; Townsend, Lawrence W.

    1992-01-01

    An evaluation is presented of the current understanding of the space radiation environment and the primary considerations of spacecrew exposure effects and limits. By using a two-solar particle event scenario for a 'sprint' mission to Mars, estimates are developed for the requisite shielding of the transfer vehicle and Martian surface habitat. Many uncertainties, however, are noted to have gone into these mission dose estimates; the combination of these uncertainties into an error-bar on shield mass lies beyond current capabilities.

  20. SARAH - A new homogeneous climate data record of surface radiation

    NASA Astrophysics Data System (ADS)

    Müller, Richard; Trentmann, Jörg; Träger-Chatterjee, Christine; Pfeifroth, Uwe

    2015-04-01

    Long-term observations of the surface radiation budget and cloud radiation properties are crucial for climate monitoring. Ground-based measurements provide accurate information for specific sites, but only satellite observations and data from reanalysis can provide consistent spatial information on the surface radiation budget for climate monitoring, in particular in regions with limited coverage of well maintained ground based measurements (e.g. ocean, Africa). Here, we present the new release of solar surface irradiance and cloud albedo derived from geostationary Meteosat imagery (1983 to 2013) within the EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF). The first release of the data set is widely used, e.g. in the solar energy community (e.g. PVGIS, http://re.jrc.ec.europa.eu/pvgis) and for validation of numerical weather prediction (e.g. ECMWF, DWD). The data set has a high temporal (hourly, daily and monthly means) and spatial resolution (0.05x0.05 deg) and is available free of charge from www.cmsaf.eu. The data cover Europe, Africa and the surrounding oceans. The quality of the data have been evaluated with surface measurements and compared with other satellite-based data sets. Respective results will be briefly presented. It will be shown that the CM SAF data set is well suited for climate monitoring, e.g for monitoring and analysis of extremes and trends. Within this scope key applications of the data will be presented. These include the analysis of radiation processes, extremes (heat waves) and trends for Europe, Africa and the ocean as well as solar energy applications.

  1. Radiation shielding in transit to Mars and on the surface

    NASA Astrophysics Data System (ADS)

    Conway, Edmund J.; Townsend, Lawrence W.

    An evaluation is presented of the current understanding of the space radiation environment and the primary considerations of spacecrew exposure effects and limits. By using a two-solar particle event scenario for a 'sprint' mission to Mars, estimates are developed for the requisite shielding of the transfer vehicle and Martian surface habitat. Many uncertainties, however, are noted to have gone into these mission dose estimates; the combination of these uncertainties into an error-bar on shield mass lies beyond current capabilities.

  2. Towards a continuous operational system to estimate the root-zone soil moisture from intermittent remotely sensed surface moisture

    NASA Astrophysics Data System (ADS)

    Ragab, R.

    1995-12-01

    A study has been carried out to develop and evaluate a system to estimate soil moisture content in the root-zone using active microwaves from the European Remote Sensing Satellite, ERS-1, to measure moisture content in the top 10 cm of the soil profile. Two permanent grass sites in the UK with contrasting soil types, clayey and sandy, were selected for this study. The system consists of an initialization phase, which provides surface and root-zone moisture contents as initial values for the dynamic phase of a soil water balance model. The initial value of surface moisture can be either a remotely sensed or a measured value. The surface moisture value for a given day is in turn used to derive the initial value of the root-zone moisture for the same day. This can be obtained either from an empirical relationship for drying or wetting conditions, or during drying conditions alone. Both types of relationship have been established for each of the sites, with strong coefficient of determination, R2. The two-layer soil dynamic model requires as input daily rainfall, evapotranspiration and three soil physical parameters—soil moisture at field capacity, wilting point and a pseudo-diffusivity coefficient. The first layer represents the remotely sensed layer, taken as 0-10 cm, and the second represents the root-zone, taken as 0-50 cm, for both sites. The model has been run for 1992 and 1993. The model was not initialized by remote sensing data owing to an insufficient number of microwave backscatter-surface moisture data pairs to produce a relationship with good R2. It is hoped that the continuing collection of data will improve the relationships. Initial soil moisture contents of both layers were considered to be at field capacity, which is usually the case during winter time. The dynamic model, which offers a good balance between accurate description of the processes and minimum input of data, proved capable of simulating both surface and root-zone moisture content

  3. Simulation of the UV-radiation at the Martian surface

    NASA Astrophysics Data System (ADS)

    Kolb, C.; Stimpfl, P.; Krenn, H.; Lammer, H.; Kargl, G.; Abart, R.; Patel, M. R.

    The UV-radiation at the Martian surface is for several reasons of importance. UV radiation can cause specific damages in the DNA-containing living systems and is involved in the formation of catalytically produced oxidants such as superoxide ions and peroxides. These are capable to oxidize and subsequently destroy organic matter. Lab simulations are necessary to investigate and understand the effects of organic matter removal at the Martian surface. We designed a radiation apparatus which simulates the solar spectrum at the Martian surface between 200 and 700 nm. The system consists of an UV-enhanced xenon arc lamp and special exchangeable filter-sets and mirrors for simulating the effects of the Martian atmospheric column and dust loading. A special collimating system bundles the final parallel beam so that the intensity at the target spot is independent from the distance between the ray source and the sample. The system was calibrated by means of an optical photo-spectrometer to align the ray output with the theoretical target spectrum and to ensure spectral homogeneity. We present preliminary data on calibration and performance of our system, which is integrated in the Austrian Mars simulation facility.

  4. Simultaneous decay of contact-angle and surface-tension during the rehydration of air-dried root mucilage

    NASA Astrophysics Data System (ADS)

    Arye, Gilboa; Chen, Fengxian

    2016-04-01

    Plants can extract or exude water and solutes at their root surface. Among the root exudates, the mucilage exhibits a surfactant like properties - depressing the surface-tension (ST, mN/m) at the water-air interface. The amphipathic nature of some of the mucilage molecules (e.g. lipids) is thought to be the reason for its surfactant like behavior. As the rhizosphere dries out, re-orientation and/or re-configuration of amphipathic molecules at the solid-air interface, may impart hydrophobic nature to the rhizosphere. Our current knowledge on the ST of natural and/or model root mucilage is based on measurements of the equilibrium ST. However, adsorption of amphipathic molecules at the water-air interface is not reached instantaneously. The hydrophobic nature of the rhizosphere was deduced from the initial advancing CA, commonly calculated from the first few milliseconds up to few seconds (depending on the method employed). We hypothesized that during the rehydration of the root mucilage; both quantities are dynamic. Processes such as water absorbance and dissolution, may vary the interfacial tensions as a function of time. Consequently, simultaneous reduction of both CA and ST as a function of time can be expected. The main objective of this study was to characterize and quantify the extent, persistency and dynamic of the CA and ST during rehydration of air-dried root mucilage. The study was involved with measurements of dynamic and equilibrium ST using the pedant drop or Wilhelmy plate method, respectively. Glass slides were coated with naturally occurring or model root mucilage and the CA of a sessile drop was measured optically, as a function of time. The results were analyzed based on the Young-Dupré and Young-Laplace equations, from which the simultaneous decay of CA and ST was deduced. The implication for the wettability and water flow in the rhizosphere will be discussed.

  5. An In-Situ Root-Imaging System in the Context of Surface Detection of CO2

    NASA Astrophysics Data System (ADS)

    Apple, M. E.; Prince, J. B.; Bradley, A. R.; Zhou, X.; Lakkaraju, V. R.; Male, E. J.; Pickles, W.; Thordsen, J. J.; Dobeck, L.; Cunningham, A.; Spangler, L.

    2009-12-01

    Carbon sequestration is a valuable method of spatially confining CO2 belowground. The Zero Emissions Research Technology, (ZERT), site is an experimental facility in a former agricultural field on the Montana State University campus in Bozeman, Montana, where CO2 was experimentally released at a rate of 200kg/day in 2009 into a 100 meter underground injection well running parallel to the ground surface. This injection well, or pipe, has deliberate leaks at intervals, and CO2 travels from these leaks upward to the surface of the ground. The ZERT site is a model system designed with the purpose of testing methods of surface detection of CO2. One important aspect of surface detection is the determination of the effects of CO2 on the above and belowground portions of plants growing above sequestration fields. At ZERT, these plants consist of a pre-existing mixture of herbaceous species present at the agricultural field. Species growing at the ZERT site include several grasses, Dactylis glomerata (Orchard Grass), Poa pratensis (Kentucky Bluegrass), and Bromus japonicus (Japanese Brome); the nitrogen-fixing legumes Medicago sativa, (Alfalfa), and Lotus corniculatus, (Birdsfoot trefoil); and an abundance of Taraxacum officinale, (Dandelion). Although the aboveground parts of the plants at high CO2 are stressed, as indicated by changes in hyperspectral plant signatures, leaf fluorescence and leaf chlorophyll content, we are interested in determining whether the roots are also stressed. To do so, we are combining measurements of soil conductivity and soil moisture with root imaging. We are using an in-situ root-imaging system manufactured by CID, Inc. (Camas, WA), along with image analysis software (Image-J) to analyze morphometric parameters in the images and to determine what effects, if any, the presence of leaking and subsequently upwelling CO2 has on the phenology of root growth, growth and turnover of individual fine and coarse roots, branching patterns, and root

  6. Effect of various concentrations of tetracycline hydrochloride demineralization on root dentin surface: A scanning electron microscopic study

    PubMed Central

    Penmatsa, Tanuja; Varma, Satish; Mythili; Rao, Killi Prabhakar; Kishore, Trinath; Bindu, Hima

    2013-01-01

    Introduction: Within the last 20 years root demineralization has attracted attention as a periodontal regenerative technique. Topical tetracycline application has been widely reported for use as a conditioner, to decontaminate the root surface and to promote periodontal regeneration. The purpose of this scanning electron microscopic (SEM) study is to evaluate the surface characteristics of demineralized diseased and non-diseased dentine root surfaces using different concentrations of tetracycline hydrochloride (TTC-HCl). Material and Methods: This SEM study was carried out in 20 dentin samples obtained from non-diseased human premolars and 20 dentin samples obtained from diseased human premolars. Pure TTC-HCl was applied to the dentin surface at 50 mg/ml, 100 mg/ml and 150 mg/ml concentrations for 3 min in experimental groups while distilled (0 mg/ml) water was applied to the control groups. Statistical Analysis: Mean and standard deviation were estimated from the sample for each study group. Mean values were compared by either one-way ANOVA with Tukey-Honestly significant difference procedure or Kruskal - Wallis one way ANOVA with Mann-Whitney u-test. Further Student′s independent t-test/Mann-Whitney u-test was used appropriately to compare the mean values between two independent groups. Results: In the present study using 100 mg/ml tetracycline seems to be more effective on both diseased and non-diseased dentin surfaces. Conclusions: The results of this study confirm that pure TTC-HCl conditioning produced comparable surface characteristics on dentin of both diseased and non-diseased roots with 100 mg/ml concentration for 3 min. PMID:23946576

  7. Changes in Surface Radiation and Associated Effects on Climate

    NASA Astrophysics Data System (ADS)

    Wild, M.

    2005-12-01

    Variations in solar and thermal radiation incident at the Earth's surface profoundly affect the human environment. Increasing greenhouse gas concentrations in the atmosphere enhance the greenhouse effect at the surface manifest as a gradual increase of thermal radiation from the atmosphere down to the surface. Recent analyses of observational records confirm this expectation. Yet not only the thermal fluxes, but also solar fluxes are currently undergoing major changes. A decline of solar radiation at the land surface has become apparent in many observational records prior to 1990, a phenomenon now popularly known as "global dimming." Dimming of solar radiation was probably caused by increased air pollution, and associated levels of aerosol, as well as increasing cloud amounts. The dimming of solar radiation may also be the cause of reduced evaporation between 1960 and 1990 measured worldwide with evaporation pans, documenting the potential influence of solar dimming on the global hydrological cycle. Newly available surface observations from 1990 to present show, however, that the solar dimming did not persist into the 1990s. Instead, a widespread brightening has been observed since the mid-1980s. The brightening is consistent with reduction in cloudiness and an atmosphere which has recently become more transparent for sunlight. This has been favored by reduced aerosol loadings related to enhanced air pollution control and the economic breakdown in formerly communist countries in the late 1980s. The transition towards more sunlight at the Earth's surface since the late 1980s after decades of decline may have significantly affected surface climate and the global hydrological cycle. While from the 1960s to the 1980s the dimming of sunlight might have been able to counterbalance and mask to some extent the increasing greenhouse effect, leading to only moderate global temperature changes observed in this period, this has no longer been the case after the mid 1980s. The

  8. Comparison of Different Global Information Sources Used in Surface Radiative Flux Calculation: Radiative Properties of the Surface

    NASA Technical Reports Server (NTRS)

    Zhang, Yuanchong; Rossow, William B.; Stackhouse, Paul W., Jr.

    2007-01-01

    Direct estimates of surface radiative fluxes that resolve regional and weather-scale variabilty over the whole globe with reasonable accuracy have only become possible with the advent of extensive global, mostly satellite, datasets within the past couple of decades. The accuracy of these fluxes, estimated to be about 10-15 W per square meter is largely limited by the accuracy of the input datasets. The leading uncertainties in the surface fluxes are no longer predominantly induced by clouds but are now as much associated with uncertainties in the surface and near-surface atmospheric properties. This study presents a fuller, more quantitative evaluation of the uncertainties for the surface albedo and emissivity and surface skin temperatures by comparing the main available global datasets from the Moderate-Resolution Imaging Spectroradiometer product, the NASA Global Energy and Water Cycle Experiment Surface Radiation Budget project, the European Centre for Medium-Range Weather Forecasts, the National Aeronautics and Space Administration, the National Centers for Environmental Prediction, the International Satellite Cloud Climatology Project (ISCCP), the Laboratoire de Meteorologie Dynamique, NOAA/NASA Pathfinder Advanced Very High Resolution Radiometer project, NOAA Optimum Interpolation Sea Surface Temperature Analysis and the Tropical Rainfall Measuring Mission (TRMM) Microwave Image project. The datasets are, in practice, treated as an ensemble of realizations of the actual climate such that their differences represent an estimate of the uncertainty in their measurements because we do not possess global truth datasets for these quantities. The results are globally representative and may be taken as a generalization of our previous ISCCP-based uncertainty estimates for the input datasets. Surface properties have the primary role in determining the surface upward shortwave (SW) and longwave (LW) flux. From this study, the following conclusions are obtained

  9. Imaging crustal roots in the Europe-Mediterranean region: a surface wave perspective

    NASA Astrophysics Data System (ADS)

    Villaseñor, Antonio

    2016-04-01

    The thickness of crustal roots is a fundamental constrain to understand the geodynamic evolution of mountain ranges. Crustal thickness can be inferred from a variety of geophysical observables (e.g. gravity anomalies, active and passive seismic methods, etc). Deep seismic sounding (DSS) using controlled sources usually provides the most accurate images of the crustal structure and thickness. However it is an expensive method, and often only used for 2D profiles. On the other hand, passive seismology experiments based on earthquakes or ambient noise have generally lower resolution, but are cheaper to conduct and can provide 3D images. As a result of the success of USArray, experiments consisting of dense deployments of broadband seismometers have become the modern standard approach for imaging continental regions. This, in combination with the densification of permanent regional monitoring networks and the use of seismic ambient noise, has allowed to use surface waves to image with increased resolution regions such as Europe and the Mediterranean basin. Surface waves are not very sensitive to the location of discontinuities such as the Moho, but can provide good constraints on the lateral variation of crustal thickness. Here, by combining continuous recordings of array experiments and permanent networks, I present a new tomographic model of surface wave velocities in the Europe-Mediterranean region that can be used as a proxy for crustal thickness. Large low velocity anomalies corresponding to thick crust are observed as expected in mountain ranges such as the Atlas, Pyrenees and Alps where crustal thickening has occurred as a result of continental collision. In addition, similarly large low velocity anomalies are observed in regions where slab roll-back/break-off has occurred (Betic-Rif, NW and SE Carpathians, Apennines, western Balkan peninsula). While these anomalies might not all be originated by thick crust, in some cases such as the Rif-western Betics

  10. The Martian Radiation Environment from Orbit and on the Surface

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Howe, S. D.

    1999-01-01

    A good knowledge of the Martian radiation environment and its interactions with Mars is needed for many reasons. It is needed to help unfold the results of the Mars-2001 orbiter's gamma-ray spectrometer (GRS) and neutron spectrometers (NS) to determine elemental abundances on the Martian surface. It is needed to interpret the measurements of the Martian Radiation Environment Experiments (MARIE) on both the Mars 2001 orbiter and lander. It is needed to calculate production rates of cosmogenic nuclides that will be measured in samples returned from Mars. It is needed to determine the doses that astronauts would receive in Martian orbit and especially on the surface of Mars. We discuss the two types of energetic particles in the vicinity of Mars and the nature of their interactions. Solar energetic particles (SEPs) occur very rarely but can have high fluxes that are dangerous in space. However, their energies are low enough that few solar energetic particles reach the surface of Mars. Their interactions can be fairly easily modeled because SEPs create few secondary particles. Galactic cosmic rays (GCRs) have high energies and are the dominant source of energetic particles on the Martian surface, mainly secondary neutrons. Modeling their interactions is complicated because of the range of nuclei in the GCR and their high energies. Work at Los Alamos on GCR interactions will be presented.

  11. Evaluation of root water uptake in the ISBA-A-gs land surface model using agricultural yield statistics over France

    NASA Astrophysics Data System (ADS)

    Canal, N.; Calvet, J.-C.; Decharme, B.; Carrer, D.; Lafont, S.; Pigeon, G.

    2014-12-01

    The simulation of root water uptake in land surface models is affected by large uncertainties. The difficulty in mapping soil depth and in describing the capacity of plants to develop a rooting system is a major obstacle to the simulation of the terrestrial water cycle and to the representation of the impacts of drought. In this study, long time series of agricultural statistics are used to evaluate and constrain root water uptake models. The inter-annual variability of cereal grain yield and permanent grassland dry matter yield is simulated over France by the Interactions between Soil, Biosphere and Atmosphere, CO2-reactive (ISBA-A-gs) generic land surface model (LSM). The two soil profile schemes available in the model are used to simulate the above-ground biomass (Bag) of cereals and grasslands: a two-layer force-restore (FR-2L) bulk reservoir model and a multi-layer diffusion (DIF) model. The DIF model is implemented with or without deep soil layers below the root zone. The evaluation of the various root water uptake models is achieved by using the French agricultural statistics of Agreste over the 1994-2010 period at 45 cropland and 48 grassland départements, for a range of rooting depths. The number of départements where the simulated annual maximum Bag presents a significant correlation with the yield observations is used as a metric to benchmark the root water uptake models. Significant correlations (p value < 0.01) are found for up to 29 and 77% of the départements for cereals and grasslands, respectively. A rather neutral impact of the most refined versions of the model is found with respect to the simplified soil hydrology scheme. This shows that efforts should be made in future studies to reduce other sources of uncertainty, e.g. by using a more detailed soil and root density profile description together with satellite vegetation products. It is found that modelling additional subroot-zone base flow soil layers does not improve (and may even degrade

  12. Filimonas endophytica sp. nov., isolated from surface-sterilized root of Cosmos bipinnatus.

    PubMed

    Han, Ji-Hye; Kim, Tae-Su; Joung, Yochan; Kim, Seung Bum

    2015-12-01

    A Gram-stain-negative, yellow, motile by gliding, filamentous bacterium, designated SR 2-06T, was isolated from surface-sterilized root of garden cosmos. 16S rRNA gene sequence analysis indicated that SR 2-06T was related most closely to Filimonas lacunae YT21T of the family Chitinophagaceae at a sequence similarity of 96.90 %, while levels of similarity to other related taxa were less than 93.08 %. Strain SR 2-06T exhibited similar features to F. lacunae in that it contained MK-7 as the major respiratory quinone, and iso-C15 : 1 G, iso-C15 : 0 and a summed feature consisting of C16 : 1ω6c and/or C16 : 1ω7c as the major fatty acids. However, strain SR 2-06T was distinguished from F. lacunae using a combination of physiological and biochemical properties. The cellular polar lipids were phosphatidylethanolamine, unknown aminophospholipids, unknown aminolipids, an unknown phospholipid and unidentified polar lipids. The DNA G+C content was 46.0 mol%. The phenotypic and phylogenetic evidence clearly indicates that strain SR 2-06T represents a novel species of the genus Filimonas, for which the name Filimonas endophytica sp. nov. is proposed. The type strain is SR 2-06T ( = KCTC 42060T = JCM 19844T). PMID:26443022

  13. Changes in the size of the apparent surface area and adsorption energy of the rye roots by low pH and the presence of aluminium ions induced

    NASA Astrophysics Data System (ADS)

    Szatanik-Kloc, Alicja

    2016-07-01

    The plant reactions on Al-stress include i.a. change of the surface area of the roots, which in the physicochemistry of plants characterizes the transport of water and ions through the root. The object of this study is the specific surface area of the roots of plants which are tolerant to aluminium, such as rye. Plants of rye were grown in a nutrient solution for 14 days at pH 4.5 in the presence of Al3+ ions of concentration 10, 20, and 40 mg dm-3. The control plants were grown continuously at pH 7 or pH 4.5 without Al3+. The apparent surface area and adsorption energy of the plants roots were determined from water vapour adsorption - desorption data. The apparent surface area of roots growing in the aluminium was (with respect to control) statistically significantly lower. There were no statistically significant differences in the apparent surface area of the roots which grew in pH 7, pH 4.5 without Al3+. The average water vapour adsorption energy of the root surface, under stress conditions decreased. In the roots grown in the presence of Al+3, there was a slight decrease in high energy adsorption centres and an increase in the amount of low-energy centres.

  14. Surface energy and radiation balance systems - General description and improvements

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.; Simpson, James R.

    1989-01-01

    Surface evaluation of sensible and latent heat flux densities and the components of the radiation balance were desired for various vegetative surfaces during the ASCOT84 experiment to compare with modeled results and to relate these values to drainage winds. Five battery operated data systems equipped with sensors to determine the above values were operated for 105 station days during the ASCOT84 experiment. The Bowen ratio energy balance technique was used to partition the available energy into the sensible and latent heat flux densities. A description of the sensors and battery operated equipment used to collect and process the data is presented. In addition, improvements and modifications made since the 1984 experiment are given. Details of calculations of soil heat flow at the surface and an alternate method to calculate sensible and latent heat flux densities are provided.

  15. Radiative Properties of Smoke and Aerosol Over Land Surfaces

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2000-01-01

    This talk discusses smoke and aerosol's radiative properties with particular attention to distinguishing the measurement over clear sky from clouds over land, sea, snow, etc. surfaces, using MODIS Airborne Simulator data from (Brazil, arctic sea ice and tundra and southern Africa, west Africa, and other ecosystems. This talk also discusses the surface bidirectional reflectance using Cloud Absorption Radiometer, BRDF measurements of Saudi Arabian desert, Persian Gulf, cerrado and rain forests in Brazil, sea ice, tundra, Atlantic Ocean, Great Dismal Swamp, Kuwait oil fire smoke. Recent upgrades to instrument (new TOMS UVA channels at 340 and 380 planned use in Africa (SAFARI 2000) and possibly for MEIDEX will also be discussed. This talk also plans to discuss the spectral variation of surface reflectance over land and the sensitivity of off-nadir view angles to correlation between visible near-infrared reflectance for use in remote sensing of aerosol over land.

  16. Radiative interactions with micromachined surfaces: Spectral polarized emittance. Final report

    SciTech Connect

    Zemel, J.N.

    1995-05-01

    This report covers work aimed at obtaining additional information on the electromagnetic emissions from heated, microstructured surface. Earlier work had established that thermal emission was a useful means for obtaining broad band information on the electromagnetic properties of these surfaces. Among the earlier results obtained was a demonstration that there was an increased amount of coherent radiation emitted from these structures. Also found was that the nature of the emission was dependent on the carrier concentration of the emitting material as well as the details of the geometry of surface structures. Described in this report is the normal polarized emissivity of undoped silicon gratings of different dimensions measured with a new emissometer. Deep grating fabrication, formation of a titanium silicide layer, and wafer cutting is described.

  17. A semi-empirical model for estimating surface solar radiation from satellite data

    NASA Astrophysics Data System (ADS)

    Janjai, Serm; Pattarapanitchai, Somjet; Wattan, Rungrat; Masiri, Itsara; Buntoung, Sumaman; Promsen, Worrapass; Tohsing, Korntip

    2013-05-01

    This paper presents a semi-empirical model for estimating surface solar radiation from satellite data for a tropical environment. The model expresses solar irradiance as a semi-empirical function of cloud index, aerosol optical depth, precipitable water, total column ozone and air mass. The cloud index data were derived from MTSAT-1R satellite, whereas the aerosol optical depth data were obtained from MODIS/Terra satellite. The total column ozone data were derived from OMI/AURA satellite and the precipitable water data were obtained from NCEP/NCAR. A five year period (2006-2010) of these data and global solar irradiance measured at four sites in Thailand namely, Chiang Mai (18.78 °N, 98.98 °E), Nakhon Pathom (13.82 °N, 100.04 °E), Ubon Ratchathani (15.25 °N, 104.87 °E) and Songkhla (7.20 °N, 100.60 °E), were used to derive the coefficients of the model. To evaluate its performance, the model was used to calculate solar radiation at four sites in Thailand namely, Phisanulok (16.93 °N, 100.24 °E), Kanchanaburi (14.02 °N, 99.54 °E), Nongkhai (17.87 °N, 102.72 °E) and Surat Thani (9.13 °N, 99.15 °E) and the results were compared with solar radiation measured at these sites. It was found that the root mean square difference (RMSD) between measured and calculated values of hourly solar radiation was in the range of 25.5-29.4%. The RMSD is reduced to 10.9-17.0% for the case of monthly average hourly radiation. The proposed model has the advantage in terms of the simplicity for applications and reasonable accuracy of the results.

  18. Conjugate natural convection flow over a vertical surface with radiation

    NASA Astrophysics Data System (ADS)

    Siddiqa, Sadia; Hossain, Md. Anwar; Gorla, Rama Subba Reddy

    2016-06-01

    Numerical study of conjugate natural convection flow over a finite vertical surface with radiation is reported in this article. Rosseland diffusion approximation is used to express the radiative heat flux term. The governing boundary-layer equations are made dimensionless by means of a suitable form of non-similarity transformation. These equations are obtained in three regimes: (1) upstream (when ξ → 0), (2) downstream (when ξ → ∞ ) and (3) entire regime and are solved numerically. The solutions in the upstream and downstream regimes are obtained via shooting method whereas two-point implicit finite difference method is used to get the solutions for the entire regime. It is seen that asymptotic solutions give accurate results when compared with the numerical solution of the entire regime. The results indicate that the flow field and the temperature distributions are greatly influenced by thermal radiation parameter , R_d, surface temperature parameter, θ _w and Prandtl number Pr. It is established from the analysis that recirculation occurs in the flow specifically for R_d=1.5.

  19. Effect of surface treatments on radiation buildup in steam generators

    SciTech Connect

    Asay, R.H. ); Pick, M.E. . Berkeley Nuclear Labs.); Roofthooft, R. , Linkebeek ); van Melsen, C. )

    1991-11-01

    Test coupons of typical PWR materials of construction were prepared using a number of pretreatments to minimize radiation buildup. The coupons were then exposed to primary coolant at the Doel-2 PWR in Belgium. The exposure periods for the coupons ranged from one to three fuel cycles. After removal from the primary system, doserate and gamma spectroscopy measurements were made to determine the radioactivity levels on the coupons. Varying levels of success were achieved for the preconditioning techniques tested. Electropolishing alone provided some degree of resistance to radiation buildup on the treated surface and electropolishing plus passivation was shown to be even better. Radiation buildup resistance of the palladium-coated coupons was poor; radiation levels on these coupons were even higher than on the untreated reference coupons. The poor performance of the palladium-coated coupons was possibly due to the method used to apply the coating. In contrast to palladium coating, very encouraging results were achieved with chromium plating plus passivation. Preliminary results show that this technique can inhibit activity deposition by as much as a factor of ten. 4 refs., 64 figs., 26 tabs.

  20. Isolated True Surface Wave in a Radiative Band on a Surface of a Stressed Auxetic

    NASA Astrophysics Data System (ADS)

    Trzupek, D.; Zieliński, P.

    2009-08-01

    We demonstrate that a surface resonance (pseudosurface wave) may transform into a true surface wave, i.e., acquire an infinite lifetime, at a single isolated point within a bulk band (radiative region) in a model of a stressed auxetic material. In contrast with the secluded supersonic elastic surface waves, the one found here does not belong to a dispersion line of true surface waves. Therefore we propose to call it an isolated true surface wave (ITSW). The ITSW manifests itself by a deltalike peak in the local density of states and by anomalies in reflection coefficients. The phenomenon may be useful in redirecting energy and/or information from the bulk to the surface in devices supporting guided acoustic waves.

  1. Extension of Kirchhoff's formula to radiation from moving surfaces

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Myers, M. K.

    1988-01-01

    Kirchhoff's formula for radiation from a closed surface has been used recently for prediction of the noise of high speed rotors and propellers. Because the closed surface on which the boundary data are prescribed in these cases is in motion, an extension of Kirchhoff's formula to this condition is required. In this paper such a formula, obtained originally by Morgans for the interior problem, is derived for regions exterior to surfaces moving at speeds below the wave propagation speed by making use of some results of generalized function theory. It is shown that the usual Kirchhoff formula is a special case of the main result of the paper. The general result applies to a deformable surface. However, the special form it assumes for a rigid surface in motion is also noted. In addition, Morgans' result is further extended by showing that edge line integrals appear in the formula when applied to a surface that is piecewise smooth. Some possible areas of application of the formula to problems of current interest in aeroacoustics are discussed.

  2. Extension of Kirchhoff's formula to radiation from moving surfaces

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Myers, M. K.

    1987-01-01

    Kirchhoff's formula for radiation from a closed surface has been used recently for prediction of the noise of high speed rotors and propellers. Because the closed surface on which the boundary data are prescribed in these cases is in motion, an extension of Kirchhoff's formula to this condition is required. In this paper such a formula, obtained originally by Morgans for the interior problem, is derived for regions exterior to surfaces moving at speeds below the wave propagation speed by making use of some results of generalized function theory. It is shown that the usual Kirchhoff formula is a special case of the main result of the paper. The general result applies to a deformable surface. However, the special form it assumes for a rigid surface in motion is also noted. In addition, Morgans' result is further extended by showing that edge line integrals appear in the formula when applied to a surface that is piecewise smooth. Some possible areas of application of the formula to problems of current interest in aeroacoustics are discussed.

  3. Surface radiation environment of Saturn's icy moon Mimas

    NASA Astrophysics Data System (ADS)

    Nordheim, T.; Hand, K. P.; Paranicas, C.; Kollmann, P.; Jones, G. H.; Coates, A. J.; Krupp, N.

    2012-09-01

    The majority of the large icy satellites that orbit Jupiter and Saturn are embedded within the magnetospheres of their respective parent bodies. The inner regions of these magnetospheric environments are characterized by populations of trapped charged particles, from thermal plasma to high energy energetic ions and electrons. Moons orbiting within these magnetospheres are therefore often subject to continuous bombardment by multiple particle species over a wide range of energies. It is known that such bombardment may induce chemical alterations within icy surfaces through the process of radiolysis, an effect which has the potential to significantly change surface and near-surface composition over typical geological timescales. In order to make quantifiable predictions on the surface composition of these moons, it is therefore critical to have a detailed measure of deposited dose into the surface from the relevant magnetospheric particle species. Saturn's innermost large moon Mimas orbits within one of the harshest radiation environments of the Saturnian magnetosphere and remote sensing observations of the moon have revealed a surface that displays strong signs of magnetospheric weathering. It is therefore of great interest to further quantify the interaction of magnetospheric particles with the Mimantean surface, particularly with regards to determining which bombarding species dominate at different moon surface locations and surface depths and to compare this with remote sensing observations. We will present dose-depth profiles for the nearsurface which have been computed using a Monte Carlo particle transport code and representative energetic electron and proton spectra derived from measurements made by the MIMI-LEMMS particle instrument on the Cassini spacecraft.

  4. Charactering the Surface Radiation Budget over the Tibetan Plateau Using Ground Observations, Reanalysis, and Satellite Datasets

    NASA Astrophysics Data System (ADS)

    Shi, Q.; Liang, S.

    2013-12-01

    The importance of the surface radiation budget (SRB) over the Tibetan Plateau (TP) to impact not only the local climate but also the remote area (i.e., the drought and flood in China) attracts increasing attentions in the scientific communities. Observed evidences support a continuous dimming trend with predominant warming, wind stilling, and moistening trends since 1980s. Cautions, however, need to be exercised when using ground observations or satellite retrievals alone, which are limited with large errors and sparse distributions, respectively. This study aims to characterize the monthly SRB at 0.5° over the TP extending two decades by incorporating multiple datasets, including ground-measured datasets, reanalysis datasets, and satellite datasets. The fused SRB was first generated using a multiple linear regression method to synthesize reanalysis and satellite datasets with ground observations from 1984 to 2007, and was then applied not only to analyze the characteristics (spatial distribution, temporal variation, and trend) of the SRB but also to compare with selected atmospheric (cloud cover, precipitation, and water vapor) and surface (temperature, snow cover, and the Normalized Difference Vegetation Index (NDVI)) anomalies over the TP. The cross validation results suggested that the fused data lowered the root mean square errors (RMSEs) at the monthly scale (<19 W/m2) by constraining uncertainties from multiple sources (i.e., inputs, preprocessing, and data fusion). The major finding is that the interaction of solar dimming with changes of surface albedo has dominated the marked decrease of all-wave net radiation since the mid-1980s regardless of the increase of downward longwave radiation (that counteracts the increase of upward longwave radiation). Furthermore, the weakening and strengthening of the relationships between the components of SRB and the correlated variables of atmospheric or surface conditions exhibit a seasonal dependency over the TP, where

  5. Toward Improved Solar Irradiance Forecasts: Comparison of Downwelling Surface Shortwave Radiation in Arizona Derived from Satellite with the Gridded Datasets

    NASA Astrophysics Data System (ADS)

    Kim, Chang Ki; Holmgren, William F.; Stovern, Michael; Betterton, Eric A.

    2016-08-01

    The downwelling surface shortwave radiation derived from geostationary satellite imagery was compared with the available datasets for the Southwestern United States. The averaged root mean square errors for our instantaneous estimates ranged from 95.0 to 122.7 W m-2, which is lower than those derived from the MODerate resolution Imaging Spectroradiometer (MODIS). The Modern Era Retrospective-analysis for Research and Applications (MERRA) products were used to compare the hourly mean solar insolation. The three hourly mean downwelling surface shortwave radiation was evaluated by comparing the North American Regional Reanalysis (NARR) and the Clouds and the Earth's Radiant Energy System (CERES) products. Our estimates show the better performance than MERRA, NARR and CERES datasets because of coarse resolution that limits determining the solar dimming due to small clouds.

  6. Toward Improved Solar Irradiance Forecasts: Comparison of Downwelling Surface Shortwave Radiation in Arizona Derived from Satellite with the Gridded Datasets

    NASA Astrophysics Data System (ADS)

    Kim, Chang Ki; Holmgren, William F.; Stovern, Michael; Betterton, Eric A.

    2016-05-01

    The downwelling surface shortwave radiation derived from geostationary satellite imagery was compared with the available datasets for the Southwestern United States. The averaged root mean square errors for our instantaneous estimates ranged from 95.0 to 122.7 W m-2, which is lower than those derived from the MODerate resolution Imaging Spectroradiometer (MODIS). The Modern Era Retrospective-analysis for Research and Applications (MERRA) products were used to compare the hourly mean solar insolation. The three hourly mean downwelling surface shortwave radiation was evaluated by comparing the North American Regional Reanalysis (NARR) and the Clouds and the Earth's Radiant Energy System (CERES) products. Our estimates show the better performance than MERRA, NARR and CERES datasets because of coarse resolution that limits determining the solar dimming due to small clouds.

  7. Spatial regression between soil surface elevation, water storage in root zone and biomass productivity of alfalfa within an irrigated field

    NASA Astrophysics Data System (ADS)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2014-05-01

    Efficiency of water use for the irrigation purposes is connected to the variety of circumstances, factors and processes appearing along the transportation path of water from its sources to the root zone of the plant. Water efficiency of agricultural irrigation is connected with variety of circumstances, the impacts and the processes occurring during the transportation of water from water sources to plant root zone. Agrohydrological processes occur directly at the irrigated field, these processes linked to the infiltration of the applied water subsequent redistribution of the infiltrated water within the root zone. One of them are agrohydrological processes occurring directly on an irrigated field, connected with infiltration of water applied for irrigation to the soil, and the subsequent redistribution of infiltrated water in the root zone. These processes have the strongly pronounced spatial character depending on the one hand from a spatial variation of some hydrological characteristics of soils, and from other hand with distribution of volume of irrigation water on a surface of the area of an irrigated field closely linked with irrigation technology used. The combination of water application parameters with agrohydrological characteristics of soils and agricultural vegetation in each point at the surface of an irrigated field leads to formation of a vector field of intensity of irrigation water. In an ideal situation, such velocity field on a soil surface should represent uniform set of vertically directed collinear vectors. Thus values of these vectors should be equal to infiltration intensities of water inflows on a soil surface. In soil profile the field of formed intensities of a water flow should lead to formation in it of a water storage accessible to root system of irrigated crops. In practice this ideal scheme undergoes a lot of changes. These changes have the different nature, the reasons of occurrence and degree of influence on the processes connected

  8. Decadal Variability of Surface Incident Solar Radiation over China

    NASA Astrophysics Data System (ADS)

    Wang, Kaicun

    2015-04-01

    Observations have reported a widespread dimming of surface incident solar radiation (Rs) from the 1950s to the 1980s and a brightening afterwards. However, none of the state-of-the-art earth system models, including those from the Coupled Model Intercomparison Project phase 5 (CMIP5), could successfully reproduce the dimming/brightening rates over China. This study provides metadata and reference data to investigate the observed variability of Rs in China. From 1958 to 1990, diffuse solar radiation (Rsdif) and direct solar radiation (Rsdir) was measured separately in China, from which Rs was calculated a sum. However, pyranometers used to measure Rsdif had a strong sensitivity drift problem, which introduced a spurious decreasing trend to Rsdif and Rs measurements. The observed Rsdir did not suffer from such sensitivity drift problem. From 1990 to 1993, the old instruments were replaced and measuring stations were relocated in China, which introduced an abrupt increase in the observed Rs. After 1993, Rs was measured by solid black thermopile pyranometers. Comprehensive comparisons between observation-based and model-based Rs performed in this research have shown that sunshine duration (SunDu)-derived Rs is of high quality and provide accurate estimate of decadal variability of Rs over China. SunDu-derived Rs averaged over 105 stations in China decreased at -2.9 W m-2 per decade from 1961 to 1990 and remained stable afterward. This decadal variability has been confirmed by the observed Rsdir, independent studies on aerosols and diurnal temperature range, and can be reproduced by certain high-quality earth system models. However, neither satellite retrievals (the Global Energy and Water Exchanges Project Surface Radiation Budget (GEWEX SRB)) nor reanalyses (ERA-Interim and Modern-Era Retrospective analysis for Research and Applications (MERRA)) can accurately reproduce such decadal variability of Rs over China for their exclusion of annual variability of tropospheric

  9. Global Surface Ultraviolet Radiation Climatology from TOMS and ERBE Data

    NASA Technical Reports Server (NTRS)

    Lubin, Dan

    1998-01-01

    The overall goal of this project has been to develop a method for calculating the distribution of solar ultraviolet radiation (UVR) over most of the earth's surface using NASA's Total Ozone Mapping Spectrometer (TOMS) and Earth Radiation Budget Experiment (ERBE) data, and to use this method to develop a UVR climatology that is useful in the context of the global ozone depletion issue. The research carried out with this support has resulted the following accomplishments: (1) a radioactive transfer method. based on the delta-Eddington approximation, was successfully developed; (2) the method was applied to the five years of overlapping TOMS and ERBE Monthly-Hourly data to examine the impact of global variability in cloud cover on trends in surface UVR; (3) a presentation was made on effects of stratospheric ozone depletion; (4) the radioactive transfer model was finally applied to all daylight hours to make a through study of the global effect of cloud cover;and (6) a five-year global climatology of surface UVR based on all of the research has been prepared for general distribution.

  10. Impact of buildings on surface solar radiation over urban Beijing

    NASA Astrophysics Data System (ADS)

    Zhao, Bin; Liou, Kuo-Nan; Gu, Yu; He, Cenlin; Lee, Wee-Liang; Chang, Xing; Li, Qinbin; Wang, Shuxiao; Tseng, Hsien-Liang R.; Leung, Lai-Yung R.; Hao, Jiming

    2016-05-01

    The rugged surface of an urban area due to varying buildings can interact with solar beams and affect both the magnitude and spatiotemporal distribution of surface solar fluxes. Here we systematically examine the impact of buildings on downward surface solar fluxes over urban Beijing by using a 3-D radiation parameterization that accounts for 3-D building structures vs. the conventional plane-parallel scheme. We find that the resulting downward surface solar flux deviations between the 3-D and the plane-parallel schemes are generally ±1-10 W m-2 at 800 m grid resolution and within ±1 W m-2 at 4 km resolution. Pairs of positive-negative flux deviations on different sides of buildings are resolved at 800 m resolution, while they offset each other at 4 km resolution. Flux deviations from the unobstructed horizontal surface at 4 km resolution are positive around noon but negative in the early morning and late afternoon. The corresponding deviations at 800 m resolution, in contrast, show diurnal variations that are strongly dependent on the location of the grids relative to the buildings. Both the magnitude and spatiotemporal variations of flux deviations are largely dominated by the direct flux. Furthermore, we find that flux deviations can potentially be an order of magnitude larger by using a finer grid resolution. Atmospheric aerosols can reduce the magnitude of downward surface solar flux deviations by 10-65 %, while the surface albedo generally has a rather moderate impact on flux deviations. The results imply that the effect of buildings on downward surface solar fluxes may not be critically significant in mesoscale atmospheric models with a grid resolution of 4 km or coarser. However, the effect can play a crucial role in meso-urban atmospheric models as well as microscale urban dispersion models with resolutions of 1 m to 1 km.

  11. Surface summertime radiative forcing by shallow cumuli at the Atmospheric Radiation Measurement Southern Great Plains site

    SciTech Connect

    Berg, Larry K.; Kassianov, Evgueni I.; Long, Charles N.; Mills Jr., David L.

    2011-01-08

    Although shallow cumuli are common over large areas of the globe, their impact on the surface radiative forcing has not been carefully evaluated. This study addresses this shortcoming by analyzing data from days with shallow cumuli collected over eight summers (2000-2007) at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (collectively ACRF) Southern Great Plains site. During periods with clouds, the average shortwave and longwave radiative forcings are 45.5 W m-2 and +11.6 W m-2, respectively. The forcing has been defined so that a negative (positive) forcing indicates a surface cooling (warming). On average, the shortwave forcing is negative, however, instances with positive shortwave forcing are observed approximately 20% of the time. These positive values of shortwave forcing are associated with three-dimensional radiative effects of the clouds. The three-dimensional effects are shown to be largest for intermediate cloud amounts. The magnitude of the three-dimensional effects decreased with averaging time, but it is not negligibly small even for large averaging times as long as four hours.

  12. Evaluation of root water uptake in the ISBA-A-gs land surface model using agricultural yield statistics over France

    NASA Astrophysics Data System (ADS)

    Canal, N.; Calvet, J.-C.; Decharme, B.; Carrer, D.; Lafont, S.; Pigeon, G.

    2014-05-01

    The interannual variability of cereal grain yield and permanent grassland dry matter yield is simulated over French sites by the Interactions between Soil, Biosphere and Atmosphere, CO2-reactive (ISBA-A-gs) generic Land Surface Model (LSM). The two soil profile schemes available in the model are used to simulate the above-ground biomass (Bag) of cereals and grasslands: a 2-layer force-restore (FR-2L) bulk reservoir model and a multi-layer diffusion (DIF) model. The DIF model is implemented with or without deep soil layers below the root-zone. The evaluation of the various root water uptake models is achieved by using the French agricultural statistics of Agreste over the 1994-2010 period at 45 cropland and 48 grassland sites, for a range of rooting depths. The number of sites where the simulated annual maximum Bag presents a significant correlation with the yield observations is used as a metric to benchmark the root water uptake models. Significant correlations (p value < 0.01) are found for up to 29% of the cereal sites and 77% of the grassland sites. It is found that modelling additional subroot zone base flow soil layers does not improve (and may even degrade) the representation of the interannual variability of the vegetation above-ground biomass. These results are particularly robust for grasslands as calibrated simulations are able to represent the extreme 2003 and 2007 years corresponding to unfavourable and favourable fodder production, respectively.

  13. Large Scale Surface Radiation Budget from Satellite Observation

    NASA Technical Reports Server (NTRS)

    Pinker, R. T.

    1995-01-01

    During the current reporting period, the focus of our work was on preparing and testing an improved version of our Surface Radiation Budget algorithm for processing the ISCCP D1 data routinely at the SRB Satellite Data Analysis Center (SDAC) at NASA Langley Research Center. The major issues addressed are related to gap filling and to testing whether observations made from ERBE could be used to improve current procedures of converting narrowband observations, as available from ISCCP, into broadband observations at the TOA. The criteria for selecting the optimal version are to be based on results of intercomparison with ground truth.

  14. Response of nickel surface to pulsed fusion plasma radiations

    SciTech Connect

    Niranjan, Ram Rout, R. K. Srivastava, R. Gupta, Satish C.; Chakravarthy, Y.; Patel, N. N.; Alex, P.

    2014-04-24

    Nickel based alloys are being projected as suitable materials for some components of the next generation fusion reactor because of compatible thermal, electrical and mechanical properties. Pure nickel material is tested here for possibility of similar application purpose. Nickel samples (> 99.5 % purity) are exposed here to plasma radiations produced due to D-D fusion reaction inside an 11.5 kJ plasma focus device. The changes in the physical properties of the nickel surface at microscopic level which in turn change the mechanical properties are analyzed using scanning electron microscope, optical microscope, glancing incident X-ray diffractometer and Vicker's hardness gauge. The results are reported here.

  15. Variability of surface solar radiation in unforced CMIP5 simulations

    NASA Astrophysics Data System (ADS)

    Folini, Doris; Wild, Martin

    2016-04-01

    We examine the natural variability of surface solar radiation (SSR) under pre-industrial conditions with time-invariant forcing in control runs in global climate simulations of the latest coupled model intercomparison project, CMIP5. We consider global and regional scales, as well as annual and seasonal data. Special emphasis is given to the likelihood of spurious SSR trends. To address this question, we determine for each model the range of linear SSR trends as function of the number of years over which the trend is taken. We discuss our findings with regard to potential aerosol induced dimming and its detectability in the second half of the 20th century.

  16. Quantum-radiative cooling for solar cells with textured surface

    NASA Astrophysics Data System (ADS)

    Gilman, Boris; Ivanov, Igor

    2004-11-01

    Efficient technique of Quantum Radiative Cooling (QRC) of textured Solar Cells and Modules is described that is capable of Solar Module (SM) temperature reduction by 5-20C, resulting in 3-10% efficiency increase. Novel methods are based on the quantum assisted IR emission from the surface covered by either multi-layer coatings made of Si-nitride, SiO or Si oxy-nitride films or specifically designed insulating sun-transparent chamber (QRC zone) that contains Selective Emissive (SE) gas or gas mix. QRC zone is mounted on the top of Solar Module replacing existing lamination coatings. To enhance the efficiency of QRC some specific methods and fabrication procedures are proposed to form an electricly charged textured surface that provide a high Electric Field at the surface thus enhancing IR emissivity from the surface. Such procedure can be also used to form the field Induced Surface Barriers in the Si-based Solar Cells that can substitute the existing diffused Emitters resulting in significant reduction of the Cycle Time as well as prospective Fabrication Cost.

  17. SYRA3 COST Action--Microbeam radiation therapy: Roots and prospects.

    PubMed

    Bravin, Alberto; Olko, Pawel; Schültke, Elisabeth; Wilkens, Jan J

    2015-09-01

    Microbeam radiation therapy (MRT) is an irradiation modality for therapeutic purposes which uses arrays of collimated quasi parallel microbeams, each up to 100 μm wide, to deliver high radiation doses. Several studies have reported the extraordinary tolerance of normal tissues to MRT irradiation; conversely, MRT has been shown to be highly efficient on tumor growth control. The original and most widely developed application of MRT, yet in the preclinical phase, consists in using spatially fractionated X-ray beams issued from a synchrotron radiation source in the treatment of brain tumors. More recently, MRT has been tested in successful pioneering assays to reduce or interrupt seizures in preclinical models of epilepsy. The MRT concept has also been extended to proton therapy. The development of MRT towards its clinical implementation is presently driven by an EU-supported consortium of laboratories from 16 countries within the COST Action TD1205 (SYRA3). The results of the first SYRA3 workshop on "Radiation Therapy with Synchrotron Radiation: Achievements and Challenges" held in Krakow (Poland) during March 25-26 2014 are summarized in this issue with an overview presented in this paper. The papers reflect the multidisciplinary international activities of SYRA3. The topics covered in this focus issue include medical physics aspects, pre-clinical studies, clinical applications, and an industrial perspective; finally an outlook towards future prospects of compact sources and proton microbeams. PMID:26123367

  18. Surface modification of nanoparticles for radiation curable acrylate clear coatings

    NASA Astrophysics Data System (ADS)

    Bauer, F.; Gläsel, H.-J.; Hartmann, E.; Bilz, E.; Mehnert, R.

    2003-08-01

    To obtain transparent, scratch and abrasion resistant coatings a high content of nanosized silica and alumina filler was embedded in radiation-curable acrylate formulations by acid catalyzed silylation using trialkoxysilanes. 29SiMAS NMR and MALDI-TOF mass spectrometry were employed to elucidate the structure of the surface-grafted methacryloxypropyl-, vinyl- and n-propyl-trimethoxysilane. In accordance with NMR findings, MALDI-TOF MS showed highly condensed oligomeric siloxanes of more than 20 monomeric silane units. A ladder-like structure of bound polysiloxanes is proposed rather than a simplified picture of tridentate silane bonding. Hence, silane coupling agents do not only modify the chemical nature of the filler surface but also strongly effect the rheological properties of the acrylate nanodispersions.

  19. Estimating surface longwave radiative fluxes from satellites utilizing artificial neural networks

    NASA Astrophysics Data System (ADS)

    Nussbaumer, Eric A.; Pinker, Rachel T.

    2012-04-01

    A novel approach for calculating downwelling surface longwave (DSLW) radiation under all sky conditions is presented. The DSLW model (hereafter, DSLW/UMD v2) similarly to its predecessor, DSLW/UMD v1, is driven with a combination of Moderate Resolution Imaging Spectroradiometer (MODIS) level-3 cloud parameters and information from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim model. To compute the clear sky component of DSLW a two layer feed-forward artificial neural network with sigmoid hidden neurons and linear output neurons is implemented; it is trained with simulations derived from runs of the Rapid Radiative Transfer Model (RRTM). When computing the cloud contribution to DSLW, the cloud base temperature is estimated by using an independent artificial neural network approach of similar architecture as previously mentioned, and parameterizations. The cloud base temperature neural network is trained using spatially and temporally co-located MODIS and CloudSat Cloud Profiling Radar (CPR) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations. Daily average estimates of DSLW from 2003 to 2009 are compared against ground measurements from the Baseline Surface Radiation Network (BSRN) giving an overall correlation coefficient of 0.98, root mean square error (rmse) of 15.84 W m-2, and a bias of -0.39 W m-2. This is an improvement over an earlier version of the model (DSLW/UMD v1) which for the same time period has an overall correlation coefficient 0.97 rmse of 17.27 W m-2, and bias of 0.73 W m-2.

  20. Urban Surface Radiative Energy Budgets Determined Using Aircraft Scanner Data

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.; Estes, Maury G.; Arnold, James E. (Technical Monitor)

    2002-01-01

    the surface energy budget. Knowledge of it is important in any attempt to describe the radiative and mass fluxes which occur at the surface. Use of energy terms in modeling surface energy budgets allows the direct comparison of various land surfaces encountered in a urban landscape, from vegetated (forest and herbaceous) to non-vegetated (bare soil, roads, and buildings). These terms are also easily measured using remote sensing from aircraft or satellite platforms allowing one to examine the spacial variability. The partitioning of energy budget terms depends on the surface type. In natural landscapes, the partitioning is dependent on canopy biomass, leaf area index, aerodynamic roughness, and moisture status, all of which are influenced by the development stage of the ecosystem. In urban landscapes, coverage by man-made materials substantially alters the surface face energy budget. The remotely sensed data obtained from aircraft and satellites, when properly calibrated allows the measurement of important terms in the radiative surface energy budget a urban landscape scale.

  1. Surface Radiation Budget Variability at Climatic Time Scales

    NASA Astrophysics Data System (ADS)

    Pinker, R. T.; Ma, Y.; Nussbaumer, E.

    2014-12-01

    Information on Earth Radiation Balance is needed at climatic time scales for enabling assessment of variability and trends in the forcing functions of the climate system. Satellite observations have been instrumental for advancing the understanding of such balance at global scale; yet, the length of available records does not meet climatic needs. Major issues hindering such efforts are related to the frequent changes in satellite observing systems, including the specification of the satellite instruments, and changes in the quality of atmospheric inputs that drive the inference schemes. In this paper we report on an effort to synthesize estimates of shortwave, longwave and spectral surface radiative fluxes by fusing observations from numerous satellite platforms that include MODIS observations. This information was obtained in the framework of the MEaSURES and NEWS programs; it will be evaluated against ground observations and compared to independent satellite and model estimates. Attention will be given to updates on our knowledge on the radiative balance as compared to what is known from shorter time records.

  2. Extracting Metrics for Three-dimensional Root Systems: Volume and Surface Analysis from In-soil X-ray Computed Tomography Data.

    PubMed

    Suresh, Niraj; Stephens, Sean A; Adams, Lexor; Beck, Anthon N; McKinney, Adriana L; Varga, Tamas

    2016-01-01

    Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to climate change and crop management. Quantitative size information on roots in their native environment is invaluable for studying root growth and environmental processes involving plants. X-ray computed tomography (XCT) has been demonstrated to be an effective tool for in situ root scanning and analysis. We aimed to develop a costless and efficient tool that approximates the surface and volume of the root regardless of its shape from three-dimensional (3D) tomography data. The root structure of a Prairie dropseed (Sporobolus heterolepis) specimen was imaged using XCT. The root was reconstructed, and the primary root structure was extracted from the data using a combination of licensed and open-source software. An isosurface polygonal mesh was then created for ease of analysis. We have developed the standalone application imeshJ, generated in MATLAB(1), to calculate root volume and surface area from the mesh. The outputs of imeshJ are surface area (in mm(2)) and the volume (in mm(3)). The process, utilizing a unique combination of tools from imaging to quantitative root analysis, is described. A combination of XCT and open-source software proved to be a powerful combination to noninvasively image plant root samples, segment root data, and extract quantitative information from the 3D data. This methodology of processing 3D data should be applicable to other material/sample systems where there is connectivity between components of similar X-ray attenuation and difficulties arise with segmentation. PMID:27168248

  3. Changes in biologically active ultraviolet radiation reaching the Earth's surface.

    PubMed

    McKenzie, Richard L; Björn, Lars Olof; Bais, Alkiviadis; Ilyasad, Mohammad

    2003-01-01

    Since publication of the 1998 UNEP Assessment, there has been continued rapid expansion of the literature on UV-B radiation. Many measurements have demonstrated the inverse relationship between column ozone amount and UV radiation, and in a few cases long-term increases due to ozone decreases have been identified. The quantity, quality and availability of ground-based UV measurements relevant to assessing the environmental impacts of ozone changes continue to improve. Recent studies have contributed to delineating regional and temporal differences due to aerosols, clouds, and ozone. Improvements in radiative transfer modelling capability now enable more accurate characterization of clouds, snow-cover, and topographical effects. A standardized scale for reporting UV to the public has gained wide acceptance. There has been increased use of satellite data to estimate geographic variability and trends in UV. Progress has been made in assessing the utility of satellite retrievals of UV radiation by comparison with measurements at the Earth's surface. Global climatologies of UV radiation are now available on the Internet. Anthropogenic aerosols play a more important role in attenuating UV irradiances than has been assumed previously, and this will have implications for the accuracy of UV retrievals from satellite data. Progress has been made inferring historical levels of UV radiation using measurements of ozone (from satellites or from ground-based networks) in conjunction with measurements of total solar radiation obtained from extensive meteorological networks. We cannot yet be sure whether global ozone has reached a minimum. Atmospheric chlorine concentrations are beginning to decrease. However, bromine concentrations are still increasing. While these halogen concentrations remain high, the ozone layer remains vulnerable to further depletion from events such as volcanic eruptions that inject material into the stratosphere. Interactions between global warming and

  4. A conductive surface coating for Si-CNT radiation detectors

    NASA Astrophysics Data System (ADS)

    Valentini, Antonio; Valentini, Marco; Ditaranto, Nicoletta; Melisi, Domenico; Aramo, Carla; Ambrosio, Antonio; Casamassima, Giuseppe; Cilmo, Marco; Fiandrini, Emanuele; Grossi, Valentina; Guarino, Fausto; Angela Nitti, Maria; Passacantando, Maurizio; Santucci, Sandro; Ambrosio, Michelangelo

    2015-08-01

    Silicon-Carbon Nanotube radiation detectors need an electrically conductive coating layer to avoid the nanotube detachment from the silicon substrate and uniformly transmit the electric field to the entire nanotube active surface. Coating material must be transparent to the radiation of interest, and must provide the drain voltage necessary to collect charges generated by incident photons. For this purpose various materials have been tested and proposed in photodetector and photoconverter applications. In this article interface properties and electrical contact behavior of Indium Tin Oxide films on Carbon Nanotubes have been analyzed. Ion Beam Sputtering has been used to grow the transparent conductive layer on the nanotubes. The films were deposited at room temperature with Oxygen/Argon mixture into the sputtering beam, at fixed current and for different beam energies. Optical and electrical analyses have been performed on films. Surface chemical analysis and in depth profiling results obtained by X-ray Photoelectron Spectroscopy of the Indium Tin Oxide layer on nanotubes have been used to obtain the interface composition. Results have been applied in photodetectors realization based on multi wall Carbon Nanotubes on silicon.

  5. Rice rhizosphere soil and root surface bacterial community response to water management changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Different water management practices could affect microbial populations in the rice rhizosphere. A field-scale study was conducted to evaluate microbial populations in the root plaque and rhizosphere of rice in response to continuous and intermittent flooding conditions. Microbial populations in rhi...

  6. Surface shortwave aerosol radiative forcing during the Atmospheric Radiation Measurement Mobile Facility deployment in Niamey, Niger

    NASA Astrophysics Data System (ADS)

    McFarlane, S. A.; Kassianov, E. I.; Barnard, J.; Flynn, C.; Ackerman, T. P.

    2009-07-01

    The Atmospheric Radiation Measurement (ARM) Program's Mobile Facility (AMF) was deployed to Niamey, Niger, during 2006. Niamey, which is located in sub-Saharan Africa, is affected by both dust and biomass burning emissions. Column aerosol optical properties were derived from multifilter rotating shadowband radiometer, measurements and the vertical distribution of aerosol extinction was derived from a micropulse lidar during the two observed dry seasons (January-April and October-December). Mean aerosol optical depth (AOD) and single scattering albedo (SSA) at 500 nm during January-April were 0.53 ± 0.4 and 0.94 ± 0.05, while during October-December mean AOD and SSA were 0.33 ± 0.25 and 0.99 ± 0.01. Aerosol extinction profiles peaked near 500 m during the January-April period and near 100 m during the October-December period. Broadband shortwave surface fluxes and heating rate profiles were calculated using retrieved aerosol properties. Comparisons for noncloudy periods indicated that the remote sensing retrievals provided a reasonable estimation of the aerosol optical properties, with mean differences between calculated and observed fluxes of less than 5 W m-2 and RMS differences less than 25 W m-2. Sensitivity tests showed that the observed fluxes could be matched with variations of <10% in the inputs to the radiative transfer model. The calculated 24-h averaged SW instantaneous surface aerosol radiative forcing (ARF) was -21.1 ± 14.3 W m-2 and was estimated to account for 80% of the total radiative forcing at the surface. The ARF was larger during January-April (-28.5 ± 13.5 W m-2) than October-December (-11.9 ± 8.9 W m-2).

  7. Projections onto the Pareto surface in multicriteria radiation therapy optimization

    SciTech Connect

    Bokrantz, Rasmus E-mail: rasmus.bokrantz@raysearchlabs.com; Miettinen, Kaisa

    2015-10-15

    Purpose: To eliminate or reduce the error to Pareto optimality that arises in Pareto surface navigation when the Pareto surface is approximated by a small number of plans. Methods: The authors propose to project the navigated plan onto the Pareto surface as a postprocessing step to the navigation. The projection attempts to find a Pareto optimal plan that is at least as good as or better than the initial navigated plan with respect to all objective functions. An augmented form of projection is also suggested where dose–volume histogram constraints are used to prevent that the projection causes a violation of some clinical goal. The projections were evaluated with respect to planning for intensity modulated radiation therapy delivered by step-and-shoot and sliding window and spot-scanned intensity modulated proton therapy. Retrospective plans were generated for a prostate and a head and neck case. Results: The projections led to improved dose conformity and better sparing of organs at risk (OARs) for all three delivery techniques and both patient cases. The mean dose to OARs decreased by 3.1 Gy on average for the unconstrained form of the projection and by 2.0 Gy on average when dose–volume histogram constraints were used. No consistent improvements in target homogeneity were observed. Conclusions: There are situations when Pareto navigation leaves room for improvement in OAR sparing and dose conformity, for example, if the approximation of the Pareto surface is coarse or the problem formulation has too permissive constraints. A projection onto the Pareto surface can identify an inaccurate Pareto surface representation and, if necessary, improve the quality of the navigated plan.

  8. Intrapulpal temperature changes during root surface irradiation with dual-wavelength laser (2780 and 940 nm): in vitro study

    NASA Astrophysics Data System (ADS)

    Franzen, Rene; Rashidisangsary, Borna; Ozturan, Seda; Vanweersch, Leon; Gutknecht, Norbert

    2015-01-01

    The present study evaluated the intrapulpal thermal changes that occurred during the treatment of the root surfaces with a laser system emitting Er,Cr:YSGG 2780- and 940-nm diode laser irradiation in an alternating sequence. Thirty single-rooted human teeth were collected. The teeth were divided into three groups (n=10 each) and irradiated with Er,Cr:YSGG alone or combined with a 940-nm diode laser. To investigate the intrapulpal temperature changes, specimens were embedded in a resin block with a set of thermocouples introduced at different positions within the root canals. The first group was irradiated with only Er,Cr:YSGG (25 mJ, 50 Hz, 50 μs pulse duration, water and air spray); the second group was irradiated with Er,Cr:YSGG (same setting) and a 940-nm diode (2 W, chopped mode with 20% duty cycle); the third group was irradiated with Er,Cr:YSGG (same setting) and a diode (2 W, chopped mode with 50% duty cycle). During all irradiations, thermal changes were recorded in real time with thermocouples. While group 3 showed thermal rises on average of 1.68±0.98°C in the pulp chamber, groups 1 and 2 showed average temperature rises of <0.5°C. The combined laser emission of 2780 and 940 nm is a promising way for root surface debridement without inducing intrapulpal thermal damage when using an appropriate water/air spray. All measured temperatures were considerably below the critical value of 5.6°C.

  9. Radiation induced chemical activity at iron and copper oxide surfaces

    NASA Astrophysics Data System (ADS)

    Reiff, Sarah C.

    The radiolysis of three iron oxides, two copper oxides, and aluminum oxide with varying amounts of water were performed using gamma-rays and 5 MeV 4He ions. The adsorbed water on the surfaces was characterized using temperature programmed desorption and diffuse reflectance infrared spectroscopy, which indicated that all of the oxides had chemisorbed water on the surface. Physisorbed water was observed on the Fe2O 3 and Al2O3 surfaces as well. Molecular hydrogen was produced from adsorbed water only on Fe2O3 and Al 2O3, while the other compounds did not show any hydrogen production due to the low amounts of water on the surfaces. Slurries of varying amounts of water were also examined for hydrogen production, and they showed yields that were greater than the yield for bulk water. However, the yields of hydrogen from the copper compounds were much lower than those of the iron suggesting that the copper oxides are relatively inert to radiation induced damage to nearby water. X-ray diffraction measurements did not show any indication of changes to the bulk crystal structure due to radiolysis for any of the oxides. The surfaces of the oxides were analyzed using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). For the iron samples, FeO and Fe3O4, Raman spectroscopy revealed areas of Fe2O3 had formed following irradiation with He ions. XPS indicated the formation of a new oxygen species on the iron oxide surfaces. Raman spectroscopy of the copper oxides did not reveal any changes in the surface composition, however, XPS measurements showed a decrease in the amount of OH groups on the surface of Cu2O, while for the CuO samples the amount of OH groups were found to increase following radiolysis. Pristine Al2O3 showed the presence of a surface oxyhydroxide layer which was observed to decrease following radiolysis, consistent with the formation of molecular hydrogen.

  10. Hypothetical Protein Avin_16040 as the S-Layer Protein of Azotobacter vinelandii and Its Involvement in Plant Root Surface Attachment

    PubMed Central

    Jong, Bor Chyan

    2015-01-01

    A proteomic analysis of a soil-dwelling, plant growth-promoting Azotobacter vinelandii strain showed the presence of a protein encoded by the hypothetical Avin_16040 gene when the bacterial cells were attached to the Oryza sativa root surface. An Avin_16040 deletion mutant demonstrated reduced cellular adherence to the root surface, surface hydrophobicity, and biofilm formation compared to those of the wild type. By atomic force microscopy (AFM) analysis of the cell surface topography, the deletion mutant displayed a cell surface architectural pattern that was different from that of the wild type. Escherichia coli transformed with the wild-type Avin_16040 gene displayed on its cell surface organized motifs which looked like the S-layer monomers of A. vinelandii. The recombinant E. coli also demonstrated enhanced adhesion to the root surface. PMID:26276116

  11. Near-polytropic stellar simulations with a radiative surface

    NASA Astrophysics Data System (ADS)

    Barekat, A.; Brandenburg, A.

    2014-11-01

    Context. Studies of solar and stellar convection often employ simple polytropic setups using the diffusion approximation instead of solving the proper radiative transfer equation. This allows one to control separately the polytropic index of the hydrostatic reference solution, the temperature contrast between top and bottom, and the Rayleigh and Péclet numbers. Aims: Here we extend such studies by including radiative transfer in the gray approximation using a Kramers-like opacity with freely adjustable coefficients. We study the properties of such models and compare them with results from the diffusion approximation. Methods: We use the Pencil code, which is a high-order finite difference code where radiation is treated using the method of long characteristics. The source function is given by the Planck function. The opacity is written as κ = κ0ρaTb, where a = 1 in most cases, b is varied from -3.5 to + 5, and κ0 is varied by four orders of magnitude. We adopt a perfect monatomic gas. We consider sets of one-dimensional models and perform a comparison with the diffusion approximation in one- and two-dimensional models. Results: Except for the case where b = 5, we find one-dimensional hydrostatic equilibria with a nearly polytropic stratification and a polytropic index close to n = (3 - b)/(1 + a), covering both convectively stable (n> 3/2) and unstable (n< 3/2) cases. For b = 3 and a = -1, the value of n is undefined a priori and the actual value of n depends then on the depth of the domain. For large values of κ0, the thermal adjustment time becomes long, the Péclet and Rayleigh numbers become large, and the temperature contrast increases and is thus no longer an independent input parameter, unless the Stefan-Boltzmann constant is considered adjustable. Conclusions: Proper radiative transfer with Kramers-like opacities provides a useful tool for studying stratified layers with a radiative surface in ways that are more physical than what is possible with

  12. Caries resistance of lased human root surface with 10.6 μm CO2 laser-thermal, morphological, and microhardness analysis

    NASA Astrophysics Data System (ADS)

    de Souza-Zaroni, W. C.; Freitas, A. C. P.; Hanashiro, F. S.; Steiner-Oliveira, C.; Nobre-Dos-Santos, M.; Youssef, M. N.

    2010-02-01

    Although the cariostatic effects of CO2 laser on enamel have been shown, its effects on root surface demineralization remains uncertain. The objectives of this in vitro research was to establish safe parameters for a pulsed 10.6 μm CO2 laser and to evaluate its effect on morphological features of the root surface, as well as on the reduction of root demineralization. Ninety-five human root surfaces were randomly divided into five groups: G1-No treatment (control); G2—2.5 J/cm2; G3—4.0 J/cm2; G4—5.0 J/cm2; and G5—6.0 J/cm2. Intrapulpal temperature was evaluated during root surface irradiation by a thermocouple and morphological changes were evaluated by SEM. After the surface treatment, the specimens were submitted to a 7-day pH-cycling model. Subsequently, the cross-sectional Knoop microhardness values were measured. For all irradiated groups, intrapulpal temperature changes were less than 1.5°C. Scanning electron microscopy images indicated that fluences as low as 4.0 J/cm2 were sufficient to induce morphological changes in the root surface. Additionally, for fluences reaching or exceeding 4.0 J/cm2, laser-induced inhibitory effects on root surface demineralization were observed. It was concluded that laser energy density in the range of 4.0 to 6.0 J/cm2 could be applied to a dental root to reduce demineralization of this surface without compromising pulp vitality.

  13. Effects of Er,Cr:YSGG Laser Treatment on Human Gingival Fibroblast Attachment, Viability and Morphology of Root Surface: An In Vitro Study.

    PubMed

    Amid, Reza; Azizi, Elahe; Ardakani, Mohammad Reza Talebi; Ashnagar, Sajjad; Moiahedi, Seyed Masoud

    2016-05-01

    Rehabilitation of periodontal support is the main goal of therapies for periodontitis. Hand instrumentation with curettes, piezoelectric ultrasonic scalers and lasers, such as Er,Cr:YSGG, are used for this purpose. This study was designed to evaluate human gingival fibroblast viability attachment to root surfac after modification with the mentioned therapeutic alternatives. Lasers showed significantly lower cell viability after 72 hours compared to hand instrumentation and ultrasound, probably due to more irregular root surfaces after treatment. PMID:27290823

  14. Estimating photosynthetically available radiation at the ocean surface from GOCI data

    NASA Astrophysics Data System (ADS)

    Frouin, Robert; McPherson, John

    2012-09-01

    A technique is presented to estimate photosynthetically available radiation (PAR) at the ocean surface from Geostationary Ocean Color Imager (GOCI) data. The sensor is adapted to the problem, since it measures at visible wavelengths and does not saturate over clouds, and the hourly data provides adequate temporal sampling to describe diurnal variability of clouds. Instantaneous surface PAR is computed as the difference between the solar irradiance incident at the top of the atmosphere (known) and the solar irradiance reflected back to space (derived from GOCI radiance), taking into account absorption and scattering by the clear atmosphere (modeled). Knowledge of pixel composition is not required. Apart from planetary albedo and sun zenith angle, the model parameters are fixed at their climatological values. The instantaneous PAR estimates at hourly intervals are integrated over time to provide daily values. The technique is applied to GOCI imagery acquired on 5 April 2011, and the GOCI daily PAR estimates are compared with those obtained from MODerate Resolution Imaging Spectrometer (MODIS) data. Agreement is good between the two types of estimates, with a coefficient of determination ( r 2) of 0.778, a bias of 0.23 Em-2d-1 (0.5% with higher GOCI values), and a root-mean-squared difference of 5.00 Em-2d-1 (11.2%). Differences in cloudy conditions are attributed to daily cloudiness changes not captured by the MODIS observations. The comparison statistics indicate that GOCI PAR estimates have acceptable accuracy for regional studies of aquatic photosynthesis.

  15. Can radiation therapy treatment planning system accurately predict surface doses in postmastectomy radiation therapy patients?

    SciTech Connect

    Wong, Sharon; Back, Michael; Tan, Poh Wee; Lee, Khai Mun; Baggarley, Shaun; Lu, Jaide Jay

    2012-07-01

    Skin doses have been an important factor in the dose prescription for breast radiotherapy. Recent advances in radiotherapy treatment techniques, such as intensity-modulated radiation therapy (IMRT) and new treatment schemes such as hypofractionated breast therapy have made the precise determination of the surface dose necessary. Detailed information of the dose at various depths of the skin is also critical in designing new treatment strategies. The purpose of this work was to assess the accuracy of surface dose calculation by a clinically used treatment planning system and those measured by thermoluminescence dosimeters (TLDs) in a customized chest wall phantom. This study involved the construction of a chest wall phantom for skin dose assessment. Seven TLDs were distributed throughout each right chest wall phantom to give adequate representation of measured radiation doses. Point doses from the CMS Xio Registered-Sign treatment planning system (TPS) were calculated for each relevant TLD positions and results correlated. There were no significant difference between measured absorbed dose by TLD and calculated doses by the TPS (p > 0.05 (1-tailed). Dose accuracy of up to 2.21% was found. The deviations from the calculated absorbed doses were overall larger (3.4%) when wedges and bolus were used. 3D radiotherapy TPS is a useful and accurate tool to assess the accuracy of surface dose. Our studies have shown that radiation treatment accuracy expressed as a comparison between calculated doses (by TPS) and measured doses (by TLD dosimetry) can be accurately predicted for tangential treatment of the chest wall after mastectomy.

  16. Sensor intercomparison of distributed surface radiation measurement system

    NASA Astrophysics Data System (ADS)

    Dou, Baocheng; Wen, Jianguang; Li, Xiuhong; Liu, Qiang; Xiao, Qing; Bai, Junhua; Peng, Jingjing; Lin, Xingwen; Zhang, Zhigang; Wu, Xiaodan; Cai, Erli; Zhang, Jialin; Chang, Chongyan

    2015-12-01

    The Wireless Sensor Networks of Coarse-resolution Pixel Parameters (CPP-WSN) was established to monitor the heterogeneity of coarse spatial resolution pixel, with consideration of different categories of land surface parameters in Huailai, Hebei province, China (40.349°N, 115.785°E). The observation network of radiation parameters (RadNet) in CPP-WSN was developed for multi-band radiation measurement and consisted of 6 nodes covering 2km*2km area to capture its heterogeneity. Each node employed four sensors to observe the five radiation parameters. The number and location of nodes in RadNet were determined through the representativeness-based sampling method. Thus, the RadNet is a distributed observation system with nodes work synchronously and measurements used together. The intercomparison experiment for RadNet is necessary and was conducted in Huailai Remote Sensing Station from 5th Aug to 10th Aug in 2012. Time series observations from various sensors were collected and analyzed. The maximum relative differences among sensors of UVR, SWR, LWR, PAR, and LST are 4.83%, 5.3%, 3.71%, 11%, and 0.54%, respectively. Sensor/parameter differences indeed exist and are considerable large for PAR, SWR, UVR, and LWR, which cannot be ignored. The linear normalization and quadratic polynomial normalization perform similar for CUV5/UVR, PQS1/PAR, CNR4/SWR, and SI-111/LST. As for CNR4/LWR, quadratic polynomial normalization show higher accuracy than linear normalization, especially in node2, node4, and node5. Thus, the LWR measured by CNR4 is proved to be nonlinear, and should be normalized with quadratic polynomial coefficients for higher precision.

  17. Colonization on Root Surface by a Phenanthrene-Degrading Endophytic Bacterium and Its Application for Reducing Plant Phenanthrene Contamination

    PubMed Central

    Liu, Juan; Liu, Shuang; Sun, Kai; Sheng, Yuehui; Gu, Yujun; Gao, Yanzheng

    2014-01-01

    A phenanthrene-degrading endophytic bacterium, Pn2, was isolated from Alopecurus aequalis Sobol grown in soils contaminated with polycyclic aromatic hydrocarbons (PAHs). Based on morphology, physiological characteristics and the 16S rRNA gene sequence, it was identified as Massilia sp. Strain Pn2 could degrade more than 95% of the phenanthrene (150 mg·L−1) in a minimal salts medium (MSM) within 48 hours at an initial pH of 7.0 and a temperature of 30°C. Pn2 could grow well on the MSM plates with a series of other PAHs, including naphthalene, acenaphthene, anthracene and pyrene, and degrade them to different degrees. Pn2 could also colonize the root surface of ryegrass (Lolium multiflorum Lam), invade its internal root tissues and translocate into the plant shoot. When treated with the endophyte Pn2 under hydroponic growth conditions with 2 mg·L−1 of phenanthrene in the Hoagland solution, the phenanthrene concentrations in ryegrass roots and shoots were reduced by 54% and 57%, respectively, compared with the endophyte-free treatment. Strain Pn2 could be a novel and useful bacterial resource for eliminating plant PAH contamination in polluted environments by degrading the PAHs inside plants. Furthermore, we provide new perspectives on the control of the plant uptake of PAHs via endophytic bacteria. PMID:25247301

  18. Do satellites detect trends in surface solar radiation?

    PubMed

    Pinker, R T; Zhang, B; Dutton, E G

    2005-05-01

    Long-term variations in solar radiation at Earth's surface (S) can affect our climate, the hydrological cycle, plant photosynthesis, and solar power. Sustained decreases in S have been widely reported from about the year 1960 to 1990. Here we present an estimate of global temporal variations in S by using the longest available satellite record. We observed an overall increase in S from 1983 to 2001 at a rate of 0.16 watts per square meter (0.10%) per year; this change is a combination of a decrease until about 1990, followed by a sustained increase. The global-scale findings are consistent with recent independent satellite observations but differ in sign and magnitude from previously reported ground observations. Unlike ground stations, satellites can uniformly sample the entire globe. PMID:15879215

  19. The initial attachment of cemental fibrils to the root dentin surface in acellular and cellular cementogenesis in rat molars.

    PubMed

    Yamamoto, T; Domon, T; Takahashi, S; Islam, M N; Suzuki, R

    2001-03-01

    To elucidate the initial attachment mechanism of cemental fibrils to the root dentin surface in acellular and cellular cementogenesis, developing rat molars were observed by light microscopy and scanning electron microscopy combined with NaOH maceration. The NaOH maceration was used to observe details of the positional association of cemental and dentinal fibrils during cementogenesis. An initial hematoxylin stained, cementum layer began to form on the root dentin surface with the first dentin mineralization in both acellular and cellular cementogenesis. The initial attachment of cemental fibrils to the dentin surface also began at this point. At the initial attachment the intermingling of cemental and dentinal fibrils occurred only in places. With advanced cementogenesis the initial cementum layer became the fibril-poor cemento-dentinal junction. This suggests that cemental fibrils attach on the initial cementum layer, and not directly on dentinal fibrils, so that the layer results in the fibril-poor cemento-dentinal junction. The present study suggests that an intervening adhesive is necessary for the cemento-dentinal attachment at any stage of cementogenesis in rat molars. PMID:11325058

  20. Calibration facilities for borehole and surface environmental radiation measurements

    SciTech Connect

    Stromswold, D.C.

    1994-04-01

    Measuring radiation from contaminated soil and buildings is important in the cleanup of land areas and facilities. It provides the means for quantifying the amount of contamination and assessing the success of efforts to restore areas to acceptable conditions for public use. Instruments that measure in situ radiation from natural or radiochemically-contaminated earth formations must be calibrated in appropriate facilities to provide quantitative assessments of concentrations of radionuclides. For instruments that are inserted into boreholes, these calibration facilities are typically special models having holes for probe insertion and having sufficient size to appear radiometrically ``infinite`` in extent. The US Department of Energy (DOE) has such models at Hanford, Washington, and Grand Junction, Colorado. They are concrete cylinders having a central borehole and containing known, enhanced amounts of K, U, and Th for spectral gamma-ray measurements. Additional models contain U for calibrating neutron probes for fissile materials and total-count gamma-ray probes. Models for calibrating neutron probes for moisture measurements in unsaturated formations exist for steel-cased boreholes at Hanford and for uncased boreholes at the DOE`s Nevada Test Site. Large surface pads are available at Grand Junction for portable, vehicle-mounted, or airplane-mounted spectral gamma-ray detectors.

  1. A tunable terahertz radiation source based on a surface wave transformed into Cherenkov radiation in a subwavelength array

    NASA Astrophysics Data System (ADS)

    Zhang, Ping; Hu, Min; Zhong, Renbin; Cheng, Xiaoxing; Gong, Sen; Zhao, Tao; Liu, Shenggang

    2016-04-01

    A tunable THz radiation source based on the Cherenkov radiation mechanism is proposed. In the structure of a dielectric medium rod covered by subwavelength metal ring array, the surface wave is excited by electron bunch on the subwavelength metal ring array, and then transformed into Cherenkov radiation in the dielectric medium rod. The working frequency is determined by the intersection of the surface wave dispersion curve and electron beam line, and could be tuned by adjusting the beam energy. The source, which is compact and operable at room temperature, generates radiation with peak power from microwatts up to milliwatts.

  2. Comparative SEM study on the effect of different demineralization methods with tetracycline HCl on healthy root surfaces.

    PubMed

    Işik, G; Ince, S; Sağlam, F; Onan, U

    1997-09-01

    Periodontal regeneration through the use of root demineralization received a lot of interest in periodontology. Topical application of acid to dentin surfaces produced a zone of demineralization, exposing dentin collagen fibrils and opening dentin tubules. In this study, the in vitro effects of different tetracycline HCl application techniques were investigated. According to the results of this SEM study, it may be desirable to apply tetracycline HCl using burnishing technique to expose maximum intertubular fibrils and for the tubular openings. However, this technique should be studied when placed in an in vivo system. PMID:9378828

  3. Shallow Subsurface Soil Moisture Dynamics in the Root-Zone and Bulk Soil of Sparsely Vegetated Land Surfaces as Impacted by Near-Surface Atmospheric State

    NASA Astrophysics Data System (ADS)

    Trautz, A.; Illangasekare, T. H.; Tilton, N.

    2015-12-01

    Soil moisture is a fundamental state variable that provides the water necessary for plant growth and evapotranspiration. Soil moisture has been extensively studied in the context of bare surface soils and root zones. Less attention has focused on the effects of sparse vegetation distributions, such as those typical of agricultural cropland and other natural surface environments, on soil moisture dynamics. The current study explores root zone, bulk soil, and near-surface atmosphere interactions in terms of soil moisture under different distributions of sparse vegetation using multi-scale laboratory experimentation and numerical simulation. This research is driven by the need to advance our fundamental understanding of soil moisture dynamics in the context of improving water conservation and next generation heat and mass transfer numerical models. Experimentation is performed in a two-dimensional 7.3 m long intermediate scale soil tank interfaced with a climate-controlled wind tunnel, both of which are outfitted with current sensor technologies for measuring atmospheric and soil variables. The soil tank is packed so that a sparsely vegetated soil is surrounded by bulk bare soil; the two regions are separated by porous membranes to isolate the root zone from the bulk soil. Results show that in the absence of vegetation, evaporation rates vary along the soil tank in response to longitudinal changes in humidity; soil dries fastest upstream where evaporation rates are highest. In the presence of vegetation, soil moisture in the bulk soil closest to a vegetated region decreases more rapidly than the bulk soil farther away. Evapotranspiration rates in this region are also higher than the bulk soil region. This study is the first step towards the development of more generalized models that account for non-uniformly distributed vegetation and land surfaces exhibiting micro-topology.

  4. Formation of micron and submicron structures on a zirconium oxide surface exposed to nanosecond laser radiation

    SciTech Connect

    Ganin, D V; Mikolutskiy, S I; Khomich, V Yu; Yamshchikov, V A; Tokarev, V N; Shmakov, V A

    2014-04-28

    Possibility of forming quasi-periodic structures of micron and submicron dimensions on a surface of zirconium dioxide under the action of eximer ArF laser radiation is shown experimentally and theoretically. (interaction of laser radiation with matter)

  5. Radiation dominated acoustophoresis driven by surface acoustic waves.

    PubMed

    Guo, Jinhong; Kang, Yuejun; Ai, Ye

    2015-10-01

    Acoustophoresis-based particle manipulation in microfluidics has gained increasing attention in recent years. Despite the fact that experimental studies have been extensively performed to demonstrate this technique for various microfluidic applications, numerical simulation of acoustophoresis driven by surface acoustic waves (SAWs) has still been largely unexplored. In this work, a numerical model taking into account the acoustic-piezoelectric interaction was developed to simulate the generation of a standing surface acoustic wave (SSAW) field and predict the acoustic pressure field in the liquid. Acoustic radiation dominated particle tracing was performed to simulate acoustophoresis of particles with different sizes undergoing a SSAW field. A microfluidic device composed of two interdigital transducers (IDTs) for SAW generation and a microfluidic channel was fabricated for experimental validation. Numerical simulations could well capture the focusing phenomenon of particles to the pressure nodes in the experimental observation. Further comparison of particle trajectories demonstrated considerably quantitative agreement between numerical simulations and experimental results with fitting in the applied voltage. Particle switching was also demonstrated using the fabricated device that could be further developed as an active particle sorting device. PMID:26070191

  6. Tunable surface plasmon instability leading to emission of radiation

    SciTech Connect

    Gumbs, Godfrey; Iurov, Andrii; Huang, Danhong; Pan, Wei

    2015-08-07

    We propose a new approach for energy conversion from a dc electric field to tunable terahertz emission based on hybrid semiconductors by combining two-dimensional (2D) crystalline layers and a thick conducting material with possible applications for chemical analysis, security scanning, medical (single-molecule) imaging, and telecommunications. The hybrid nano-structure may consist of a single or pair of sheets of graphene, silicene, or a 2D electron gas. When an electric current is passed through a 2D layer, we discover that two low-energy plasmon branches exhibit a characteristic loop in their dispersion before they merge into an unstable region beyond a critical wave vector q{sub c}. This finite q{sub c} gives rise to a wavenumber cutoff in the emission dispersion of the surface plasmon induced instability and emission of radiation (spiler). However, there is no instability for a single driven layer far from the conductor, and the instability of an isolated pair of 2D layers occurs without a wavenumber cutoff. The wavenumber cutoff is found to depend on the conductor electron density, layer separation, distances of layers from the conductor surface, and the driving-current strength.

  7. Development of a Space Radiation Monte-Carlo Computer Simulation Based on the FLUKE and Root Codes

    NASA Technical Reports Server (NTRS)

    Pinsky, L. S.; Wilson, T. L.; Ferrari, A.; Sala, Paola; Carminati, F.; Brun, R.

    2001-01-01

    The radiation environment in space is a complex problem to model. Trying to extrapolate the projections of that environment into all areas of the internal spacecraft geometry is even more daunting. With the support of our CERN colleagues, our research group in Houston is embarking on a project to develop a radiation transport tool that is tailored to the problem of taking the external radiation flux incident on any particular spacecraft and simulating the evolution of that flux through a geometrically accurate model of the spacecraft material. The output will be a prediction of the detailed nature of the resulting internal radiation environment within the spacecraft as well as its secondary albedo. Beyond doing the physics transport of the incident flux, the software tool we are developing will provide a self-contained stand-alone object-oriented analysis and visualization infrastructure. It will also include a graphical user interface and a set of input tools to facilitate the simulation of space missions in terms of nominal radiation models and mission trajectory profiles. The goal of this project is to produce a code that is considerably more accurate and user-friendly than existing Monte-Carlo-based tools for the evaluation of the space radiation environment. Furthermore, the code will be an essential complement to the currently existing analytic codes in the BRYNTRN/HZETRN family for the evaluation of radiation shielding. The code will be directly applicable to the simulation of environments in low earth orbit, on the lunar surface, on planetary surfaces (including the Earth) and in the interplanetary medium such as on a transit to Mars (and even in the interstellar medium). The software will include modules whose underlying physics base can continue to be enhanced and updated for physics content, as future data become available beyond the timeframe of the initial development now foreseen. This future maintenance will be available from the authors of FLUKA as

  8. In Vitro Adhesion of Streptococcus sanguinis to Dentine Root Surface After Treatment with Er:Yag Laser, Ultrasonic System, or Manual Curette

    PubMed Central

    Martins, Fernanda L.; Giorgetti, Ana Paula O.; de Freitas, Patrícia M.; Duarte, Poliana M.

    2009-01-01

    Abstract Objective: The purpose of this in vitro study was to evaluate the dentine root surface roughness and the adherence of Streptococcus sanguinis (ATCC 10556) after treatment with an ultrasonic system, Er:YAG laser, or manual curette. Background Data: Bacterial adhesion and formation of dental biofilm after scaling and root planing may be a challenge to the long-term stability of periodontal therapy. Materials and Methods: Forty flattened bovine roots were randomly assigned to one of the following groups: ultrasonic system (n = 10); Er:YAG laser (n = 10); manual curette (n = 10); or control untreated roots (n = 10). The mean surface roughness (Ra, μm) of the specimens before and after exposure to each treatment was determined using a surface profilometer. In addition, S. sanguinis was grown on the treated and untreated specimens and the amounts of retained bacteria on the surfaces were measured by culture method. Results: All treatments increased the Ra; however, the roughest surface was produced by the curettes. In addition, the specimens treated with curettes showed the highest S. sanguinis adhesion. There was a significant positive correlation between roughness values and bacterial cells counts. Conclusion: S. sanguinis adhesion was the highest on the curette-treated dentine root surfaces, which also presented the greatest surface roughness. PMID:19712018

  9. Mapping photosynthetically available radiation at the sea surface using GOCI

    NASA Astrophysics Data System (ADS)

    Choi, Jongkuk; Kim, Jihye; Yang, Hyun; Moon, Jeong-Eon; Frouin, Robert

    2016-04-01

    Photosynthetically available radiation (PAR) controls the composition of marine ecosystem by affecting the growth of phytoplankton, thus estimating PAR at the ocean surface accurately is important to understand the marine ecological environment. Although many studies have been attempted to estimate PAR employing ocean colour satellite data since 2003, previous studies using data from the polar orbit systems had spatial and temporal limitations to estimate accurate daily PAR. Here, we estimate daily PAR from Geostationary Ocean Colour Imager (GOCI) which collects data eight times a day at an hour interval in daytime and compare it with in-situ measurement and MODIS-based daily PAR. The algorithm we developed in this study, employed GOCI visible bands (centred at (412, 443, 490, 555, 660, 680 nm) which belongs to the range of PAR by calculating albedo at the layer of clouds and the sea surface to estimate daily PAR. The resultant value was validated by comparing the in-situ measurements acquired from an ocean research station, Socheongcho between February and May 2015, which showed a similar pattern with somewhat GOCI-base PAR's overestimations. The comparison with the results from MODIS, a polar orbit system showed that a good agreement with each other was illustrated at clear sky conditions, while MODIS showed some over- or underestimations at cloudy conditions with irregular patterns. This study shows that GOCI can estimate effectively the daily PAR with its advantages of acquiring data more frequently than other polar orbit ocean colour satellites by reducing the uncertainties induced by insufficient images to map the daily PAR at ocean surface.

  10. Diversity patterns of Rhizobiaceae communities inhabiting soils, root surfaces and nodules reveal a strong selection of rhizobial partners by legumes.

    PubMed

    Miranda-Sánchez, Fabiola; Rivera, Javier; Vinuesa, Pablo

    2016-09-01

    Current knowledge about rhizobial diversity patterns in non-nodule habitats is scarce, limiting our understanding of basic aspects of rhizobial ecology like competitiveness for nodule occupancy and host effects on community structure. We used a combination of cultivation-dependent and independent approaches to analyse alpha and beta diversity patterns of Rhizobiaceae communities from a conserved seasonally dry tropical forest site in central Mexico and two nearby agricultural fields. Lineage-specific recA amplicon libraries were generated from soil DNA and their sequences compared with those from root surface and nodule isolates recovered in trapping experiments from two native Acacia species and two Phaseolus vulgaris cultivars. Rarefaction analyses revealed that Rhizobiaceae diversity in soils is larger than on root surfaces, and smallest in nodules. A 'rare biosphere'-like distribution of species was found in the three habitats. Multivariate statistical analyses demonstrated that the plant genus exerted a stronger influence than the land-usage regime on the diversity of rhizobia associated with hosts. Rhizobium etli was the dominant Rhizobiaceae found in the soil libraries. It dominated nodulation of Acacia spp. and predominately harboured symbiovar mimosae-like nodC genes. A novel Rhizobium lineage (Rsp1) dominated bean nodulation. Specialist and generalist genotypes for host nodulation were detected in both species. PMID:26395550