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Sample records for lt fountain codes

  1. Prioritized LT Codes

    NASA Technical Reports Server (NTRS)

    Woo, Simon S.; Cheng, Michael K.

    2011-01-01

    The original Luby Transform (LT) coding scheme is extended to account for data transmissions where some information symbols in a message block are more important than others. Prioritized LT codes provide unequal error protection (UEP) of data on an erasure channel by modifying the original LT encoder. The prioritized algorithm improves high-priority data protection without penalizing low-priority data recovery. Moreover, low-latency decoding is also obtained for high-priority data due to fast encoding. Prioritized LT codes only require a slight change in the original encoding algorithm, and no changes at all at the decoder. Hence, with a small complexity increase in the LT encoder, an improved UEP and low-decoding latency performance for high-priority data can be achieved. LT encoding partitions a data stream into fixed-sized message blocks each with a constant number of information symbols. To generate a code symbol from the information symbols in a message, the Robust-Soliton probability distribution is first applied in order to determine the number of information symbols to be used to compute the code symbol. Then, the specific information symbols are chosen uniform randomly from the message block. Finally, the selected information symbols are XORed to form the code symbol. The Prioritized LT code construction includes an additional restriction that code symbols formed by a relatively small number of XORed information symbols select some of these information symbols from the pool of high-priority data. Once high-priority data are fully covered, encoding continues with the conventional LT approach where code symbols are generated by selecting information symbols from the entire message block including all different priorities. Therefore, if code symbols derived from high-priority data experience an unusual high number of erasures, Prioritized LT codes can still reliably recover both high- and low-priority data. This hybrid approach decides not only "how to encode

  2. Compressed image transmission based on fountain codes

    NASA Astrophysics Data System (ADS)

    Wu, Jiaji; Wu, Xinhong; Jiao, L. C.

    2011-11-01

    In this paper, we propose a joint source-channel coding (JSCC) scheme for image transmission over wireless channel. In the scheme, fountain codes are integrated into bit-plane coding for channel coding. Compared to traditional erasure codes for error correcting, such as Reed-Solomon codes, fountain codes are rateless and can generate sufficient symbols on the fly. Two schemes, the EEP (Equal Error Protection) scheme and the UEP (Unequal Error Protection) scheme are described in the paper. Furthermore, the UEP scheme performs better than the EEP scheme. The proposed scheme not only can adaptively adjust the length of fountain codes according to channel loss rate but also reconstruct image even on bad channel.

  3. FOG: Fighting the Achilles' Heel of Gossip Protocols with Fountain Codes

    NASA Astrophysics Data System (ADS)

    Champel, Mary-Luc; Kermarrec, Anne-Marie; Le Scouarnec, Nicolas

    Gossip protocols are well known to provide reliable and robust dissemination protocols in highly dynamic systems. Yet, they suffer from high redundancy in the last phase of the dissemination. In this paper, we combine fountain codes (rateless erasure-correcting codes) together with gossip protocols for a robust and fast content dissemination in large-scale dynamic systems. The use of fountain enables to eliminate the unnecessary redundancy of gossip protocols. We propose the design of FOG, which fully exploits the first exponential growth phase (where the data is disseminated exponentially fast) of gossip protocols while avoiding the need for the shrinking phase by using fountain codes. FOG voluntarily increases the number of disseminations but limits those disseminations to the exponential growth phase. In addition, FOG creates a split-graph overlay that splits the peers between encoders and forwarders. Forwarder peers become encoders as soon as they have received the whole content. In order to benefit even further and quicker from encoders, FOG biases the dissemination towards the most advanced peers to make them complete earlier.

  4. On the Energy Efficiency of LT Codes in Proactive Wireless Sensor Networks

    NASA Astrophysics Data System (ADS)

    Abouei, Jamshid; Brown, J. David; Plataniotis, Konstantinos N.; Pasupathy, Subbarayan

    2011-03-01

    This paper presents an in-depth analysis on the energy efficiency of Luby Transform (LT) codes with Frequency Shift Keying (FSK) modulation in a Wireless Sensor Network (WSN) over Rayleigh fading channels with pathloss. We describe a proactive system model according to a flexible duty-cycling mechanism utilized in practical sensor apparatus. The present analysis is based on realistic parameters including the effect of channel bandwidth used in the IEEE 802.15.4 standard, active mode duration and computation energy. A comprehensive analysis, supported by some simulation studies on the probability mass function of the LT code rate and coding gain, shows that among uncoded FSK and various classical channel coding schemes, the optimized LT coded FSK is the most energy-efficient scheme for distance d greater than the pre-determined threshold level d_T , where the optimization is performed over coding and modulation parameters. In addition, although the optimized uncoded FSK outperforms coded schemes for d < d_T , the energy gap between LT coded and uncoded FSK is negligible for d < d_T compared to the other coded schemes. These results come from the flexibility of the LT code to adjust its rate to suit instantaneous channel conditions, and suggest that LT codes are beneficial in practical low-power WSNs with dynamic position sensor nodes.

  5. A hybrid quantum key distribution protocol based on extended unitary operations and fountain codes

    NASA Astrophysics Data System (ADS)

    Lai, Hong; Xue, Liyin; Orgun, Mehmet A.; Xiao, Jinghua; Pieprzyk, Josef

    2015-02-01

    In 1984, Bennett and Brassard designed the first quantum key distribution protocol, whose security is based on quantum indeterminacy. Since then, there has been growing research activities, aiming in designing new, more efficient and secure key distribution protocols. The work presents a novel hybrid quantum key distribution protocol. The key distribution is derived from both quantum and classical data. This is why it is called hybrid. The protocol applies extended unitary operations derived from four basic unitary operations and distributed fountain codes. Compared to other protocols published so far, the new one is more secure (provides authentication of parties and detection of eavesdropping) and efficient. Moreover, our protocol still works over noisy and lossy channels.

  6. SWAAM-LT: The long-term, sodium/water reaction analysis method computer code

    SciTech Connect

    Shin, Y.W.; Chung, H.H.; Wiedermann, A.H.; Tanabe, H.

    1993-01-01

    The SWAAM-LT Code, developed for analysis of long-term effects of sodium/water reactions, is discussed. The theoretical formulation of the code is described, including the introduction of system matrices for ease of computer programming as a general system code. Also, some typical results of the code predictions for available large scale tests are presented. Test data for the steam generator design with the cover-gas feature and without the cover-gas feature are available and analyzed. The capabilities and limitations of the code are then discussed in light of the comparison between the code prediction and the test data.

  7. Designing an efficient LT-code with unequal error protection for image transmission

    NASA Astrophysics Data System (ADS)

    S. Marques, F.; Schwartz, C.; Pinho, M. S.; Finamore, W. A.

    2015-10-01

    The use of images from earth observation satellites is spread over different applications, such as a car navigation systems and a disaster monitoring. In general, those images are captured by on board imaging devices and must be transmitted to the Earth using a communication system. Even though a high resolution image can produce a better Quality of Service, it leads to transmitters with high bit rate which require a large bandwidth and expend a large amount of energy. Therefore, it is very important to design efficient communication systems. From communication theory, it is well known that a source encoder is crucial in an efficient system. In a remote sensing satellite image transmission, this efficiency is achieved by using an image compressor, to reduce the amount of data which must be transmitted. The Consultative Committee for Space Data Systems (CCSDS), a multinational forum for the development of communications and data system standards for space flight, establishes a recommended standard for a data compression algorithm for images from space systems. Unfortunately, in the satellite communication channel, the transmitted signal is corrupted by the presence of noise, interference signals, etc. Therefore, the receiver of a digital communication system may fail to recover the transmitted bit. Actually, a channel code can be used to reduce the effect of this failure. In 2002, the Luby Transform code (LT-code) was introduced and it was shown that it was very efficient when the binary erasure channel model was used. Since the effect of the bit recovery failure depends on the position of the bit in the compressed image stream, in the last decade many e orts have been made to develop LT-code with unequal error protection. In 2012, Arslan et al. showed improvements when LT-codes with unequal error protection were used in images compressed by SPIHT algorithm. The techniques presented by Arslan et al. can be adapted to work with the algorithm for image compression

  8. Molecular fountain.

    SciTech Connect

    Strecker, Kevin E.; Chandler, David W.

    2009-09-01

    A molecular fountain directs slowly moving molecules against gravity to further slow them to translational energies that they can be trapped and studied. If the molecules are initially slow enough they will return some time later to the position from which they were launched. Because this round trip time can be on the order of a second a single molecule can be observed for times sufficient to perform Hz level spectroscopy. The goal of this LDRD proposal was to construct a novel Molecular Fountain apparatus capable of producing dilute samples of molecules at near zero temperatures in well-defined user-selectable, quantum states. The slowly moving molecules used in this research are produced by the previously developed Kinematic Cooling technique, which uses a crossed atomic and molecular beam apparatus to generate single rotational level molecular samples moving slowly in the laboratory reference frame. The Kinematic Cooling technique produces cold molecules from a supersonic molecular beam via single collisions with a supersonic atomic beam. A single collision of an atom with a molecule occurring at the correct energy and relative velocity can cause a small fraction of the molecules to move very slowly vertically against gravity in the laboratory. These slowly moving molecules are captured by an electrostatic hexapole guiding field that both orients and focuses the molecules. The molecules are focused into the ionization region of a time-of-flight mass spectrometer and are ionized by laser radiation. The new molecular fountain apparatus was built utilizing a new design for molecular beam apparatus that has allowed us to miniaturize the apparatus. This new design minimizes the volumes and surface area of the machine allowing smaller pumps to maintain the necessary background pressures needed for these experiments.

  9. Fountain rainbows.

    PubMed

    Gedzelman, Stanley David; Hernández-Andrés, Javier

    2008-12-01

    We present the first measurements of radiance spectra of rainbows. The bows on two sunny days (3 and 6 June 2008) were produced by the fountain in the Parque de las Ciencias, Granada, Spain, that consists of a rectangular perimeter of 40 spray nozzles. Optical thickness of the spray from each nozzle was approximately 0.5. Spectral purity of the primary bow was highest for orange and blue, reaching values of 23% and 7%, respectively, while skylight 90 degrees from the Sun had a color purity of 34% (on 6 June). The secondary bow had much lower color purity with red absent because the regions around the bows and in Alexander's dark band were pale blue. The narrow sickle shape of the chromaticity curves for the primary bows and the absence of supernumerary bows indicated that the drop radius was between 0.2 and 0.4 mm. PMID:19037346

  10. Convolutional fountain distribution over fading wireless channels

    NASA Astrophysics Data System (ADS)

    Usman, Mohammed

    2012-08-01

    Mobile broadband has opened the possibility of a rich variety of services to end users. Broadcast/multicast of multimedia data is one such service which can be used to deliver multimedia to multiple users economically. However, the radio channel poses serious challenges due to its time-varying properties, resulting in each user experiencing different channel characteristics, independent of other users. Conventional methods of achieving reliability in communication, such as automatic repeat request and forward error correction do not scale well in a broadcast/multicast scenario over radio channels. Fountain codes, being rateless and information additive, overcome these problems. Although the design of fountain codes makes it possible to generate an infinite sequence of encoded symbols, the erroneous nature of radio channels mandates the need for protecting the fountain-encoded symbols, so that the transmission is feasible. In this article, the performance of fountain codes in combination with convolutional codes, when used over radio channels, is presented. An investigation of various parameters, such as goodput, delay and buffer size requirements, pertaining to the performance of fountain codes in a multimedia broadcast/multicast environment is presented. Finally, a strategy for the use of 'convolutional fountain' over radio channels is also presented.

  11. Carbon Dioxide Fountain

    ERIC Educational Resources Information Center

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  12. Multi-jurisdictional investigation of interactive fountain-associated cryptosporidiosis and salmonellosis outbreaks.

    PubMed

    Kirian, M L; Meregillano, G; Gennette, D; Weintraub, J M

    2008-11-01

    Interactive water fountains are established sources of gastrointestinal infections yet most health codes fail to regulate their design and operation. This report describes multi-agency, concurrent interactive fountain-associated cryptosporidiosis and salmonellosis outbreak investigations and highlights the need for the adoption of appropriate regulations for interactive fountains. PMID:18838018

  13. Multi-jurisdictional investigation of interactive fountain-associated cryptosporidiosis and salmonellosis outbreaks

    PubMed Central

    KIRIAN, M. L.; MEREGILLANO, G.; GENNETTE, D.; WEINTRAUB, J. M.

    2008-01-01

    Summary Interactive water fountains are established sources of gastrointestinal infections yet most health codes fail to regulate their design and operation. This report describes multi-agency, concurrent interactive fountain-associated cryptosporidiosis and salmonellosis outbreak investigations and highlights the need for the adoption of appropriate regulations for interactive fountains. PMID:18838018

  14. The USNO rubidium fountains

    NASA Astrophysics Data System (ADS)

    Peil, Steven; Hanssen, James; Swanson, Thomas B.; Taylor, Jennifer; Ekstrom, Christopher R.

    2016-06-01

    Four rubidium fountains at the U.S. Naval Observatory (USNO) have been in operation for 4.5 years. Each fountain has demonstrated periods of stability marked by Total or Theo deviation below 10‑16 Occasional frequency changes, on order of 1.5 times per year per fountain, introduce deviations from white-frequency noise behavior. Averaged together, the four fountains form an ensemble with a white-frequency noise level of 10‑13 and excellent long-term stability as compared to the primary frequency standards contributing to TAI. Progress on using the clocks at USNO for improving limits on coupling of fundamental constants to gravity by measuring the universality of the gravitational redshift for different types of clocks is discussed.

  15. Laser Soap Fountain

    NASA Astrophysics Data System (ADS)

    Foley, Tyler; Pegram, Matthew; Jenkins, Zachary; Hester, Brooke C.; Burris, Jennifer L.

    2015-01-01

    We have developed an eye-catching demonstration that showcases a variety of physics topics from total internal reflection to electrostatics to non-Newtonian fluid dynamics, including the Kaye effect. The essential components of the demonstration include a vertical stream of liquid soap in which a laser pointer is internally reflected, and which subsequently hits an inclined plane. As the liquid soap, a non-Newtonian fluid, begins to accumulate into a pile, its shear properties change and the incoming fluid rebounds from the pile, forming striking parabolic arcs. We present here a readily reproducible and inexpensive version of a laser soap fountain.

  16. Margaret Fountaine: a lepidopterist remembered

    PubMed Central

    Waring, Sophie

    2015-01-01

    Margaret Fountaine (1862–1940) was a lepidopterist during a period of transition and professionalization in natural history. Over her lifespan she collected more than 22 000 butterflies, published extensively and wrote a diary of more than a million words. Wealthy and independent, Fountaine toured Europe in her early twenties and then, over the next 50 years, travelled the globe collecting butterflies. Fountaine straddles many of the boundaries that historians have constructed to aid understanding of natural history in this period, specifically those defining gender roles, the nature of scientific knowledge and the divide between amateur and professional. Fountaine reminds us that these categories are never a clear or perfect division and that the reality of natural history research and exchange was much more complex than these boundaries often allow for. Fountaine herself is under-researched and this article contains a useful account of her entomological career. PMID:26489183

  17. Quantum Fountain Unipolar Lasers

    NASA Astrophysics Data System (ADS)

    Julien, Francois H.

    2001-03-01

    There is a strong interest in the development of semiconductor lasers for long-wavelength infrared applications. In the 2-20 um band, the recent demonstration of Quantum Cascade (QC) unipolar lasers is already challenging the currently available technology relying on electron-hole radiative recombination in narrow-gap semiconductors. Recently, an alternate type of unipolar laser relying on intersubband emission, the so-called Quantum Fountain intersubband laser (QF) has been proposed and demonstrated. The active region consists of periods of two GaAs/AlGaAs coupled quantum wells exhibiting three bound electron states. Electrons are optically excited from the ground state to the upper state. The radiative intersubband transition to the intermediate state gives rise to the infrared emission. Population inversion as well as fast recycling of electrons into the ground state is provided by insuring a short lifetime of electrons in the intermediate state through an enhanced scattering with LO-phonons. Although their operation imposes an external pumping source, QF lasers offer the advantages of a simplified design, of less stringent material requirements and of low internal losses due to free-carrier absorption as compared to QC lasers. In the talk, we will review the latest developments on high-brightness QF unipolar lasers emitting in the 8-16 um band. We will show that record high optical powers and single-transverse mode operation can be achieved by designing broad-area lasers with a top grating [1]. Novel designs relying on superlattice active regions will also be discussed. [1] O. Gauthier-Lafaye, B. Seguin-Roa, F. H. Julien, G. Strasser, P. Collot, C. Sirtori, J.-Y. Duboz, Physica E 7, p.12 (2000).

  18. Energy efficient rateless codes for high speed data transfer over free space optical channels

    NASA Astrophysics Data System (ADS)

    Prakash, Geetha; Kulkarni, Muralidhar; Acharya, U. S.

    2015-03-01

    Terrestrial Free Space Optical (FSO) links transmit information by using the atmosphere (free space) as a medium. In this paper, we have investigated the use of Luby Transform (LT) codes as a means to mitigate the effects of data corruption induced by imperfect channel which usually takes the form of lost or corrupted packets. LT codes, which are a class of Fountain codes, can be used independent of the channel rate and as many code words as required can be generated to recover all the message bits irrespective of the channel performance. Achieving error free high data rates with limited energy resources is possible with FSO systems if error correction codes with minimal overheads on the power can be used. We also employ a combination of Binary Phase Shift Keying (BPSK) with provision for modification of threshold and optimized LT codes with belief propagation for decoding. These techniques provide additional protection even under strong turbulence regimes. Automatic Repeat Request (ARQ) is another method of improving link reliability. Performance of ARQ is limited by the number of retransmissions and the corresponding time delay. We prove through theoretical computations and simulations that LT codes consume less energy per bit. We validate the feasibility of using energy efficient LT codes over ARQ for FSO links to be used in optical wireless sensor networks within the eye safety limits.

  19. LT25, LT50, and LT75 determinations for a diverse selection of vaccinium genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Freeze-bath cold hardiness results were used to calculate LT25 and LT75 values (temperatures causing 25% and 75% lethality, respectively) for a diverse selection of Vaccinium genotypes which had been previously analyzed for LT50 values. Overall, LT25 and LT75 values paralleled the LT50 values. Acros...

  20. Maximizing the Spectacle of Water Fountains

    ERIC Educational Resources Information Center

    Simoson, Andrew J.

    2009-01-01

    For a given initial speed of water from a spigot or jet, what angle of the jet will maximize the visual impact of the water spray in the fountain? This paper focuses on fountains whose spigots are arranged in circular fashion, and couches the measurement of the visual impact in terms of the surface area and the volume under the fountain's natural…

  1. A comparative analysis of XV-15 tiltrotor hover test data and WOPWOP predictions incorporating the fountain effect

    NASA Technical Reports Server (NTRS)

    Rutledge, Charles K.; Coffen, Charles D.; George, Albert R.

    1991-01-01

    Acoustic measurements from a hovering full scale XV-15 tilt rotor with the advanced technology blades are presented which show the directionality of fountain effect noise. Predicted acoustic directivity results are also presented which show agreement with the measured data. The aeroacoustic code, WOPWOP, was used in conjunction with a mathematical model which simulated the fountain recirculation aerodynamic effect on the rotor blade surface pressures. The predictions were used to identify the spike character in the measured data as fountain effect associated noise. The directivity of the fountain effect noise was observed to be dominant at the rear of the aircraft with increased intensities 45 degrees below the rotor disk planes.

  2. Galactic Fountains and Gas Accretion

    NASA Astrophysics Data System (ADS)

    Marinacci, F.; Binney, J.; Fraternali, F.; Nipoti, C.; Ciotti, L.; Londrillo, P.

    2010-06-01

    Star-forming disc galaxies such as the Milky Way need to accrete >~1 Msolar of gas each year to sustain their star formation. This gas accretion is likely to come from the cooling of the hot corona, however it is still not clear how this process can take place. We present simulations supporting the idea that this cooling and the subsequent accretion are caused by the passage of cold galactic-fountain clouds through the hot corona. The Kelvin-Helmholtz instability strips gas from these clouds and the stripped gas causes coronal gas to condense in the cloud's wake. For likely parameters of the Galactic corona and of typical fountain clouds we obtain a global accretion rate of the order of that required to feed the star formation.

  3. 2. Fountain without its gazebo, taken February 16, 1961, eight ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Fountain without its gazebo, taken February 16, 1961, eight years before its removal. Photographed by Jack E. Boucher. - Sons of Temperance Fountain, Independence Square (moved from Centennial Exhibition grounds at Belmont & Fountain Avenues), Philadelphia, Philadelphia County, PA

  4. Delayed-onset cytomegalovirus disease coded during hospital readmission in a multicenter retrospective cohort of liver transplant recipients (Manuscript ID LT-14-570)

    PubMed Central

    Santos, Carlos A. Q.; Brennan, Daniel C.; Chapman, William C.; Fraser, Victoria J.; Olsen, Margaret A.

    2015-01-01

    Background Delayed-onset cytomegalovirus (CMV) disease can occur among liver transplant recipients after stopping CMV prophylaxis. We hypothesized that delayed-onset CMV disease (> 100 days post-transplant) occurs more commonly than early-onset CMV disease and is associated with clinical sepsis and death. Methods We assembled a large and more representative cohort of 7,229 adult liver transplant recipients from 26 transplant centers using 2004 to 2010 ICD-9-CM billing data from 4 Healthcare Cost and Utilization Project State Inpatient Databases, and identified demographics, comorbidities, CMV disease and clinical sepsis coded during readmission, and inpatient death. Multivariate analysis was performed using Cox proportional hazards models. Results Delayed-onset CMV disease occurred in 4.3% (n=309), while early-onset CMV disease occurred in 2% (n=142). Delayed-onset CMV disease was associated with previous transplant failure or rejection (aHR 1.4, 95% CI 1.1-1.7). Clinical sepsis > 100 days post-transplant was associated with previous CMV disease (aHR 1.3, 95% CI 1.0-1.7), previous transplant failure or rejection (aHR 2.1, 95% CI 1.8-2.4), female sex (aHR 1.3, 95% CI 1.1-1.5) and several comorbidities. Death > 100 days post-transplant was associated with delayed-onset CMV disease (aHR 2.0, 95% CI 1.6-2.6), transplant failure or rejection (aHR 4.3, 95% CI 3.4-5.5), increasing age (by decade: aHR 1.1, 95% CI 1.0-1.2) and some comorbidities. Conclusions Delayed-onset CMV disease is more common than early-onset CMV disease among liver transplant recipients. Previous CMV disease may be a risk factor for clinical sepsis > 100 days post-transplant, and delayed-onset CMV disease may be a risk factor for death > 100 days post-transplant. PMID:25678072

  5. LT-HSC Methylcellulose Assay

    PubMed Central

    Kerenyi, Marc A.

    2016-01-01

    Hematopoietic differentiation is a highly complex process originating from an extraordinary population of cells called long-term repopulating hematopoietic stem cells (LT-HSCs). The unique feature of all stem cells, including HSCs, is their exceptional ability to divide asymmetrically giving rise to two different kinds of offspring. One daughter cell becomes an LT-HSC itself (self-renews) to maintain the LT-HSC pool, whereas the second daughter cell pursues a differentiation fate to ultimately give rise to terminally differentiated mature blood cells (Orkin and Zon, 2008). Quantification of phenotypic LT-HSCs can be performed by multi-color flow cytometry and the gold standard for assessment of LT-HSC self-renewal and function is competitive bone marrow transplantation (Miller et al., 2008). Although these methods are irreplaceable to determine LT-HSC abundance and functionality, they have their disadvantages and limitations. For example, competitive bone marrow transplantation is typically monitored as a function of peripheral blood donor contribution over 12–16 weeks. While reduced peripheral blood donor contribution by itself signifies impairment in the stem/progenitor cells compartment, it cannot unambiguously discriminate between reduced LT-HSC self-renewal, impaired LT-HSC differentiation or compromised progenitor cell differentiation. Here we describe an LT-HSCs methylcellulose colony-forming assay, as a fast complementary in vitro method to directly assess LT-HSC differentiation capacity. As described in Kerenyi et al. (2013), this technique acts as a powerful tool to differentiate between LT-HSC or progenitor cell differentiation defects.

  6. Is there a stratospheric fountain?

    NASA Astrophysics Data System (ADS)

    Pommereau, J.-P.; Held, G.

    2007-06-01

    of convective overshoots as proposed by Danielsen (1982) do not appear as episodic isolated features, but common and systematic events over a land convective area, that is a Stratospheric Fountain. Though the two-stages process proposed by Sherwood (2000) may also be operative, it offers a mechanism for producing the chemical, moisture and thermal properties observed in the stratosphere. The consistency between convective cooling of the TTL and weather radar echoes heights observed during the summer over South-East Brazil and the TRMM radar OPFs and LIS lightning events maximum frequencies, the latter showing also maximum events over Africa, South-East Asia, the Indonesian Islands and Northern Australia depending on the season (Liu and Zipser, 2005), suggests the existence of several "Stratospheric Fountains" over continents instead of the oceanic area of Micronesia as proposed by Newell and Gould-Stewart (1982), which appears a region of little overshoot.

  7. 2. Photocopy of the fountain in front of Philadelphia Museum ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopy of the fountain in front of Philadelphia Museum of Art, ca. 1928, courtesy of Philadelphia Museum of Art - Fountain of the Sea Horses, Aquarium Lane, Philadelphia, Philadelphia County, PA

  8. 1. FOUNTAIN IN FRONT (SOUTH) OF CLUBHOUSE. VIEW TO SOUTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. FOUNTAIN IN FRONT (SOUTH) OF CLUBHOUSE. VIEW TO SOUTHWEST. - Rainbow Hydroelectric Facility, Fountain, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  9. Physics of the granite sphere fountain

    NASA Astrophysics Data System (ADS)

    Snoeijer, Jacco H.; der Weele, Ko van

    2014-11-01

    A striking example of levitation is encountered in the "kugel fountain" where a granite sphere, sometimes weighing over a ton, is kept aloft by a thin film of flowing water. In this paper, we explain the working principle behind this levitation. We show that the fountain can be viewed as a giant ball bearing and thus forms a prime example of lubrication theory. It is demonstrated how the viscosity and flow rate of the fluid determine (i) the remarkably small thickness of the film supporting the sphere and (ii) the surprisingly long time it takes for rotations to damp out. The theoretical results compare well with measurements on a fountain holding a granite sphere of one meter in diameter. We close by discussing several related cases of levitation by lubrication.

  10. Legionellosis Outbreak Associated With a Hotel Fountain

    PubMed Central

    Smith, Shamika S.; Ritger, Kathy; Samala, Usha; Black, Stephanie R.; Okodua, Margaret; Miller, Loretta; Kozak-Muiznieks, Natalia A.; Hicks, Lauri A.; Steinheimer, Craig; Ewaidah, Saadeh; Presser, Lance; Siston, Alicia M.

    2015-01-01

    Background. In August 2012, the Chicago Department of Public Health (CDPH) was notified of acute respiratory illness, including 1 fatality, among a group of meeting attendees who stayed at a Chicago hotel during July 30–August 3, 2012. Suspecting Legionnaires' disease (LD), CDPH advised the hotel to close their swimming pool, spa, and decorative lobby fountain and began an investigation. Methods. Case finding included notification of individuals potentially exposed during July 16–August 15, 2012. Individuals were interviewed using a standardized questionnaire. An environmental assessment was performed. Results. One hundred fourteen cases were identified: 11 confirmed LD, 29 suspect LD, and 74 Pontiac fever cases. Illness onsets occurred July 21–August 22, 2012. Median age was 48 years (range, 22–82 years), 64% were male, 59% sought medical care (15 hospitalizations), and 3 died. Relative risks for hotel exposures revealed that persons who spent time near the decorative fountain or bar, both located in the lobby were respectively 2.13 (95%, 1.64–2.77) and 1.25 (95% CI, 1.09–1.44) times more likely to become ill than those who did not. Legionella pneumophila serogroup 1 was isolated from samples collected from the fountain, spa, and women's locker room fixtures. Legionella pneumophila serogroup 1 environmental isolates and a clinical isolate had matching sequence-based types. Hotel maintenance records lacked a record of regular cleaning and disinfection of the fountain. Conclusions. Environmental testing identified Legionella in the hotel's potable water system. Epidemiologic and laboratory data indicated the decorative fountain as the source. Poor fountain maintenance likely created favorable conditions for Legionella overgrowth. PMID:26716104

  11. 46 CFR 153.216 - Shower and eyewash fountains.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Vessel Requirements § 153.216 Shower and eyewash fountains. (a) Each non-self-propelled ship must have a fixed or portable shower and eyewash fountain that operates during cargo transfer and meets paragraph (c... 46 Shipping 5 2010-10-01 2010-10-01 false Shower and eyewash fountains. 153.216 Section...

  12. Department of Amplification: The Perpetual Salt Fountain.

    ERIC Educational Resources Information Center

    Arons, Arnold B.

    1995-01-01

    Presents the story of "The Perpetual Salt Fountain" to illustrate some fairly typical ramifications and vagaries in the workings of science. Outlines the discovery of double diffusive convection and uses the fact that it had been observed in the laboratory a century before its independent rediscovery to emphasize the vagaries of discovery. (23…

  13. Systematic Effects in Atomic Fountain Clocks

    NASA Astrophysics Data System (ADS)

    Gibble, Kurt

    2016-06-01

    We describe recent advances in the accuracies of atomic fountain clocks. New rigorous treatments of the previously large systematic uncertainties, distributed cavity phase, microwave lensing, and background gas collisions, enabled these advances. We also discuss background gas collisions of optical lattice and ion clocks and derive the smooth transition of the microwave lensing frequency shift to photon recoil shifts for large atomic wave packets.

  14. Radiative heating rates near the stratospheric fountain

    NASA Technical Reports Server (NTRS)

    Doherty, G. M.; Newell, R. E.; Danielsen, E. F.

    1984-01-01

    Radiative heating rates are computed for various sets of conditions thought to be appropriate to the stratospheric fountain region: with and without a layer of cirrus cloud between 100 and 150 mbar; with standard ozone and with decreased ozone in the lower stratosphere, again with and without the cirrus cloud; and with different temperatures in the tropopause region. The presence of the cloud decreases the radiative cooling below the cloud in the upper troposphere and increases the cooling above it in the lower stratosphere. The cloud is heated at the base and cooled at the top and thus radiatively destabilized; overall it gains energy by radiation. Decreasing ozone above the cloud also tends to cool the lower stratosphere. The net effect is a tendency for vertical convergence and horizontal divergence in the cloud region. High resolution profiles of temperature, ozone, and cloudiness within the fountain region are required in order to assess the final balance of the various processes.

  15. A distinctive type of ascending prominence - 'Fountain'

    NASA Technical Reports Server (NTRS)

    Tandberg-Hanssen, E.; Hansen, R. T.; Riddle, A. C.

    1975-01-01

    Cinematographic observations of solar prominences made at Mauna Loa, Hawaii, during the past few years suggest that there is a well-defined subclass of ascending prominences characterized by closed-system transference of chromospheric material along an arch or loop (up one leg and down the other). While this occurs, the entire prominence envelope steadily rises upward and expands through the corona. These prominences are denoted as 'fountains'. Several examples are described. Fountains appear to be well contained by coronal magnetic fields. Their total kinetic energy is of the order of 10 to the 30th power erg, but dissipation is typically quite slow (over time periods of 100 min or so), so that the correlative disturbances (radio bursts, coronal transients, chromospheric brightenings) are generally not spectacular or nonexistent.

  16. Hydrogen masers and cesium fountains at NRC

    NASA Technical Reports Server (NTRS)

    Boulanger, J.-S.; Morris, D.; Douglas, R. J.; Gagne, M.-C.

    1994-01-01

    The NRC masers H-3 and H-4 have been operating since June 1993 with cavity servo control. These low-flux active H masers are showing stabilities of about 10(exp -15) from 1 hour to several days. Stability results are presented, and the current and planned uses of the masers are discussed. A cesium fountain primary frequency standard project has been started at NRC. Trapping and launching experiments with the goal of 7 m/s launches are beginning. We discuss our plans for a local oscillator and servo that exploit the pulsed aspect of cesium fountain standards, and meet the challenge of 10(exp -14) tau(exp -1/2) stability without requiring masers. At best, we expect to run this frequency standard initially for periods of hours each working day rather than continuously for years, and so frequency transfer to outside laboratories has been carefully considered. We conclude that masers (or other even better secondary clocks) are required to exploit this potential accuracy of the cesium fountain. We present and discuss our conclusion that it is feasible to transfer frequency in this way with a transfer-induced uncertainty of less than 10(exp -15), even in the presence of maser frequency drift and random walk noise.

  17. Can soda fountains be recommended in hospitals?

    PubMed

    Chaberny, Iris F; Kaiser, Peter; Sonntag, Hans-Günther

    2006-09-01

    Mineral water (soda water) is very popular in Germany. Therefore, soda fountains were developed as alternatives to the traditional deposit bottle system. Nowadays, different systems of these devices are commercially available. For several years, soda fountains produced by different companies have been examined at the University Hospital of Heidelberg. In 1998, it was possible for the first time to observe and evaluate one of these systems over a period of 320 days in a series of microbiological examinations. The evaluation was implemented on the basis of the German drinking water regulation (Anonymous, 1990. Gesetz über Trinkwasser und Wasser für Lebensmittelbetriebe (Trinkwasserverordnung - TrinkwV) vom 12. Dezember 1990. Bundesgesetzblatt 66, 2613ff). Initially, the bacteria counts exceeded the reference values imposed by the German drinking water regulation in almost 50% of the analyses. Pseudomonas aeruginosa was also detected in almost 38% of the samples. After a re-arrangement of the disinfection procedure and the removal of the charcoal filter, Pseudomonas aeruginosa was not detectable any more. However, the bacteria counts still frequently exceeded the reference values of the German drinking water regulation. Following our long-term analysis, we would not recommend soda fountains in high-risk areas of hospitals. If these devices are to be used in hospitals, the disinfection procedures should be executed in weekly or fortnightly intervals and the water quality should be examined periodically. PMID:16740412

  18. Concerns about infectious hepatitis and Delacorte's Welfare Island Fountain.

    PubMed

    Spiegel, Allen D; Kavaler, Florence; Metz, Arielle A

    2004-06-01

    In 1969, philanthropist George T. Delacorte donated a spectacular water fountain to New York City on the southern tip of Welfare Island. Architects designed the fountain's jet geyser to pump a plume of water from the East River more than 400 feet into the air. Public health experts feared that the water from the heavily polluted East River could be a possible source for the spread of infectious hepatitis. Water droplets could be airborne by the prevailing winds to land on the densely populated east side of Manhattan. Upon the insistence of the New York City Department of Health, the fountain's water intake source was chlorinated. This action was initiated before the discovery of the hepatitis A virus (HAV) in 1973. A miscellany of continuing problems plagued the fountain for about two decades, causing the donor to label the fountain "Delacorte's Folly." Eventually, Delacorte gave up. In the late 1980s, the fountain ceased spouting and was finally dismantled. PMID:15141899

  19. Accuracy Evaluation of NIM5 Cesium Fountain Clock

    NASA Astrophysics Data System (ADS)

    Liu, Nian-Feng; Fang, Fang; Chen, Wei-Liang; Lin, Ping-Wei; Wang, Ping; Liu, Kun; Suo, Rui; Li, Tian-Chu

    2013-01-01

    The NIM5 fountain clock is the second fountain clock built at NIM (National Institute of Metrology, China), and has been operating stably and sub-continually since 2008. The fountain operates with a simple one-stage optical molasses to collect cold atoms, which reduces the collisional frequency shift dramatically. The fractional frequency uncertainty is estimated to be 2 × 10-15. The typical frequency instability of 2.5 × 10-14 is obtained at 10 s. Comparisons with other fountain frequency standards worldwide demonstrate agreement within the stated uncertainties.

  20. Flattening Earth acceleration in atomic fountains

    SciTech Connect

    Bertoldi, Andrea

    2010-07-15

    A method to compensate for Earth's gravity tide over an extended axial region is reported. Flattening acceleration is important in experiments where the coupling of the dynamics of free-falling probes to the gravity gradient generates stochastic noise on the measurement. Optimized cylindrically symmetric mass distributions lower Earth's tidal effect over 10 cm by a factor 10{sup 3}. A multimass compensation system with comparable performance is devised for tall atom interferometers. Reducing the gravity gradient is essential in terrestrial experiments based on atom fountain configurations being developed to precisely test general relativity or the neutrality of matter.

  1. Simulation of the formation and characteristics of ultrasonic fountain.

    PubMed

    Xu, Zheng; Yasuda, Keiji; Liu, Xiaojun

    2016-09-01

    In order to design an ultrasonic apparatus with a high throughput rate for generating atomization, the mechanism of fountain characteristics is important because the throughput rate of the ultrasonic atomization is decided by the area of the fountain surface. The formation of the fountain can be numerically studied by taking into account the effect of surface tension and radiation pressure. We have investigated the shape of the fountain with different ultrasound parameters or different kinds of solutions. When the amplitude of input sound pressure is higher than 1.3×10(5)Pa, the liquid separates from the ultrasonic fountain after irradiation for a very short period. It is further found that the area of the fountain surface increases with the concentration of the ethanol due to its low surface tension, density and sound speed. Finally, we discuss the difference between the ultrasonic fountain and the pump fountain, and find that the velocity field in the reactor induced by the pump is higher than that by the ultrasound. PMID:27150767

  2. Performance of the PARCS Testbed Cesium Fountain Frequency Standard

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna G.; Klipstein, William M.

    2004-01-01

    A cesium fountain frequency standard has been developed as a ground testbed for the PARCS (Primary Atomic Reference Clock in Space) experiment, an experiment intended to fly on the International Space Station. We report on the performance of the fountain and describe some of the implementations motivated in large part by flight considerations, but of relevance for ground fountains. In particular, we report on a new technique for delivering cooling and trapping laser beams to the atom collection region, in which a given beam is recirculated three times effectively providing much more optical power than traditional configurations. Allan deviations down to 10 have been achieved with this method.

  3. View looking down to the Oscar S. Straus Memorial Fountain. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View looking down to the Oscar S. Straus Memorial Fountain. The monument was authorized by Congress in 1927 and dedicated in 1947. It consists of the fountain and two groups of statues, Religious Freedom and Reason. It was disassembled in 1991 and reinstalled after the construction of the Ronald Reagan Building and the International Trade Center. The rededication took place in 1998 and the fountain is located near the west entrance of the building complex. - Ronald Reagan Building and International Trade Center, 1300 Pennsylvania Avenue, NW, Washington, District of Columbia, DC

  4. Benefit of combined triiodothyronine (LT(3)) and thyroxine (LT(4)) treatment in athyreotic patients unresponsive to LT(4) alone.

    PubMed

    Solter, D; Solter, M

    2012-02-01

    Despite some reports, the usefulness of levothyroxine (LT(4)) and levotriiodothyronine (LT(3)) combination therapy in hypothyroidism remains controversial. The objective of this paper is to study a benefit of additional LT(3) in athyreotic patients who failed to normalize TSH on LT(4) alone even with hyperthyroid serum T(4) values. In a survey of 200 athyreotic patients treated between 2006 and 2009, about 7% failed to normalize serum TSH levels following treatment with LT(4), though serum T(4) values in the hyperthyroid range were achieved. These patients (characterized by serum T(4)≥160 nmol/L and TSH≥5.0 mIU/L), were additionally treated with 10 μg b. i. d LT(3). LT(3) and LT(4) combination therapy resulted in decreased serum TSH levels into the normal range (12.8 vs. 1.22 mIU/L; p<0.01) and reduced LT(4) dose (153.3 vs. 117.5 μg; p<0.01) required for normalization of serum T(4) values (170.6 vs. 123.3 nmol/L; p<0.01). Serum T(3) values were higher (1.3 vs. 2.26 nmol/L; p<0.01) than those during monotherapy with LT(4). Our results indicate a subpopulation of athyreotic patients that could significantly benefit from combined LT(4) + LT(3) therapy in restoring normal TSH and thyroid hormone patterns. Further research should be undertaken to provide a genetic basis for these findings. PMID:22187290

  5. The fluid dynamics of the chocolate fountain

    NASA Astrophysics Data System (ADS)

    Townsend, Adam K.; Wilson, Helen J.

    2016-01-01

    We consider the fluid dynamics of the chocolate fountain. Molten chocolate is a mildly shear-thinning non-Newtonian fluid. Dividing the flow into three main domains—the pumped flow up the centre, the film flow over each dome, and the freely falling curtain flow between the domes—we generate a wide-ranging study of Newtonian and non-Newtonian fluid mechanics. The central pumped flow is a benchmark to elucidate the effects of shear-thinning. The dome flow can be modelled as a thin-film flow with the leading-order effects being a simple balance of gravity and viscosity. Finally, the curtain flow is analytically intractable but is related to the existing theory of water bells (both inviscid and viscous). In pipe flow, Newtonian fluids exhibit a parabolic velocity profile; shear-thinning makes the profile more blunted. In thin-film flow over the dome, gravitational and viscous effects balance and the dome shape is not important beyond the local slope. We find that the chocolate thins and slows down as it travels down the dome. Finally, in the curtain flow, we predict the shape of the falling sheet for an inviscid fluid, and compare this with the literature to predict the shape for a viscous fluid, having shown that viscous forces are too great to ignore. We also find that the primary effect driving the shape of the curtain (which falls inwards towards the axis of the fountain) is surface tension. We find that the three domains provide excellent introductions to non-Newtonian mechanics, the important mathematical technique of scaling, and how to manipulate existing data to make our own predictions. We also find that the topic generates interest among the public in our engagement work.

  6. 1. EXTERIOR VIEW, FRONT (EAST) FACADE WITH FIVE POINTS FOUNTAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR VIEW, FRONT (EAST) FACADE WITH FIVE POINTS FOUNTAIN (CENTER), DULION APARTMENTS AND ELEVENTH AVENUE SOUTH (RIGHT). VIEW TAKEN JUST AFTER BIRMINGHAM BLIZZARD OF 1993. - Highlands United Methodist Church, 1045 Twentieth Street South, Birmingham, Jefferson County, AL

  7. Intensive Exercise a Fountain of Youth for Aging Muscles

    MedlinePlus

    ... Intensive Exercise a Fountain of Youth for Aging Muscles Study found muscle tissues of elderly athletes more robust and younger ... 6, 2016 (HealthDay News) -- One key to keeping muscles young is as close as the nearest gym, ...

  8. 19th Century Textbook Illustrations - XLI, Hero's Fountain.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B.

    1982-01-01

    Presents background information on and instructions for constructing a Hero's water fountain. Includes photographs of the apparatus from old textbooks and one in the collection of the National Museum of History and Technology at the Smithsonian Institution. (SK)

  9. Unsteady three-dimensional simulation of VTOL upwash fountain turbulence

    NASA Technical Reports Server (NTRS)

    Childs, Robert E.; Nixon, David

    1987-01-01

    Numerical simulations of a planar turbulent wall jet and a planar VTOL upwash fountain were performed. These are three dimensional simulations which resolve large scale unsteady motions in the flows. The wall jet simulation shows good agreement with experimental data and is presented to verify the simulation methodology. Simulation of the upwash fountain predicts elevated shear stress and a half velocity width spreading rate of 33% which agrees well with experiment. Turbulence mechanisms which contribute to the enhanced spreading rate are examined.

  10. Cancellation of the Collisional Frequency Shift in Caesium Fountain Clocks

    SciTech Connect

    Szymaniec, K.; Chalupczak, W.; Tiesinga, E.; Williams, C. J.; Weyers, S.; Wynands, R.

    2007-04-13

    We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F=4,m{sub F}=0> atoms, depending on the initial cloud parameters. We present a theoretical model explaining our observations. The possibility of the collisional shift cancellation implies an improvement in the performance of caesium fountain standards and a simplification in their operation.

  11. Effects of either LT4 monotherapy or LT4/LT3 combined therapy in patients totally thyroidectomized for thyroid cancer.

    PubMed

    Regalbuto, Concetto; Maiorana, Raffaella; Alagona, Corradina; Paola, Roberto Di; Cianci, Michelangela; Alagona, Giovanna; Sapienza, Salvatore; Squatrito, Sebastiano; Pezzino, Vincenzo

    2007-04-01

    After total thyroidectomy all thyroid cancer patients require lifelong treatment with thyroid hormones; the treatment of choice is synthetic levothyroxine (LT4). The question of whether these patients might benefit from the combined LT4 and liothyronine (LT3) treatment has been addressed with conflicting conclusions. The aim of the present study was to compare the effects of combined low LT4/LT3 molar ratio therapy versus LT4 monotherapy on various target organs and tissues in patients thyroidectomized for thyroid cancer. Urine collection (24 hour), a fasting blood sample for laboratory examinations, thyroid function clinical score, and cardiovascular, neurological, and neuropsychological evaluations were obtained. Clinical parameters and peripheral markers of thyroid function were measured during the two different treatment regimens in 20 patients. Mean serum aspartate aminotransferase, alanine aminotransferase, sex hormone binding globulin, and osteocalcin values were significantly higher during the combined treatment. No significant differences in the clinical score, the systolic and diastolic performance, and the neurological and neuropsychological evaluations were observed between the two treatment regimens. Moreover, no alteration due to subclinical hyperthyroidism or to the fluctuations in serum T3 concentrations during the combined therapy was observed. In conclusion, we found no evidence that combined therapy with a low LT4/LT3 molar ratio resulted in improved well-being and cognitive function or in increased thyroid hormone action on peripheral tissues in respect to LT4 monotherapy. Until future large, blind, randomized, and controlled trials prove otherwise, LT4 should remain the standard treatment for thyroid cancer patients. PMID:17465862

  12. VIEW OF THE FOUNTAIN IN THE BANNEKER OVERLOOK DESIGNED BY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE FOUNTAIN IN THE BANNEKER OVERLOOK DESIGNED BY DAN URBAN KILEY AND COMPLETED AROUND 1968 - Southwest Washington, Urban Renewal Area, Bounded by Independence Avenue, Washington Avenue, South Capitol Street, Canal Street, P Street, Maine Avenue & Washington Channel, Fourteenth Street, D Street, & Twelfth Street, Washington, District of Columbia, DC

  13. Mapping the magnetic field vector in a fountain clock

    SciTech Connect

    Gertsvolf, Marina; Marmet, Louis

    2011-12-15

    We show how the mapping of the magnetic field vector components can be achieved in a fountain clock by measuring the Larmor transition frequency in atoms that are used as a spatial probe. We control two vector components of the magnetic field and apply audio frequency magnetic pulses to localize and measure the field vector through Zeeman spectroscopy.

  14. Ultrasonic atomization of liquids in drop-chain acoustic fountains

    PubMed Central

    Simon, Julianna C.; Sapozhnikov, Oleg A.; Khokhlova, Vera A.; Crum, Lawrence A.; Bailey, Michael R.

    2015-01-01

    When focused ultrasound waves of moderate intensity in liquid encounter an air interface, a chain of drops emerges from the liquid surface to form what is known as a drop-chain fountain. Atomization, or the emission of micro-droplets, occurs when the acoustic intensity exceeds a liquid-dependent threshold. While the cavitation-wave hypothesis, which states that atomization arises from a combination of capillary-wave instabilities and cavitation bubble oscillations, is currently the most accepted theory of atomization, more data on the roles of cavitation, capillary waves, and even heat deposition or boiling would be valuable. In this paper, we experimentally test whether bubbles are a significant mechanism of atomization in drop-chain fountains. High-speed photography was used to observe the formation and atomization of drop-chain fountains composed of water and other liquids. For a range of ultrasonic frequencies and liquid sound speeds, it was found that the drop diameters approximately equalled the ultrasonic wavelengths. When water was exchanged for other liquids, it was observed that the atomization threshold increased with shear viscosity. Upon heating water, it was found that the time to commence atomization decreased with increasing temperature. Finally, water was atomized in an overpressure chamber where it was found that atomization was significantly diminished when the static pressure was increased. These results indicate that bubbles, generated by either acoustic cavitation or boiling, contribute significantly to atomization in the drop-chain fountain. PMID:25977591

  15. The Ammonia Smoke Fountain: An Interesting Thermodynamic Adventure.

    ERIC Educational Resources Information Center

    Alexander, M. Dale

    1999-01-01

    Describes a new demonstration that uses an apparatus like the ammonia-fountain apparatus but with modifications designed to produce ammonium-chloride smoke. This demonstration is easy to perform, interesting to observe, and allows demonstration of the solubility of ammonia in water, the basic nature of ammonia, the acidic nature of hydrogen…

  16. HyBoLT Flight Experiment

    NASA Technical Reports Server (NTRS)

    Chen, Fang-Jeng (Frank); Berry, Scott A.

    2010-01-01

    HyBoLT was a Hypersonic Boundary Layer Transition flight experiment funded by the Hypersonics Project of the Fundamental Aeronautics Program in NASA's Aeronautics Research Mission Directorate. The HyBoLT test article mounted on the top of the ALV X-1 rocket was launched from Virginia's Wallops Island on August 22, 2008. Unfortunately a problem in the rocket's flight control system caused the vehicle to veer off the designed flight course. Launch officials activated a self-destruct mechanism in the rocket's nose cone after 20 seconds into flight. This report is a closeout document about the HyBoLT flight experiment. Details are provided of the objectives and approach associated with this experimental program as well as the 20 seconds flight data acquired before the vehicle was destroyed.

  17. ISMuLT Guidelines for muscle injuries

    PubMed Central

    Maffulli, Nicola; Oliva, Francesco; Frizziero, Antonio; Nanni, Gianni; Barazzuol, Michele; Via, Alessio Giai; Ramponi, Carlo; Brancaccio, Paola; Lisitano, Gianfranco; Rizzo, Diego; Freschi, Marco; Galletti, Stefano; Melegati, Gianluca; Pasta, Giulio; Testa, Vittorino; Valent, Alessandro; Del Buono, Angelo

    2013-01-01

    Summary Muscle injuries are frequent in high demand sports. No guidelines are available in the scientific literature. ISMuLT, the “Italian Society of Muscles, Ligaments and Tendons”, in line with its multidisciplinary mission, is proud to cover this gap. PMID:24596685

  18. The LT1 and LT2 variants of the enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LT) are associated with major ETEC lineages.

    PubMed

    Joffré, Enrique; Sjöling, Åsa

    2016-01-01

    The heat-labile toxin (LT) is one of the major virulence factors of enterotoxigenic Escherichia coli (ETEC). We recently described that 20 polymorphic LT variants are present in ETEC strains isolated globally. Two of the variants, LT1 and LT2, are particularly common and we found that they were associated with clonal ETEC lineages that express the colonization factors (CFs), CFA/I, CS1+CS3, CS2+CS3, and CS5+CS6. ETEC expressing these CFs are frequently found among ETEC strains isolated from cases with diarrhea. ETEC expressing the colonization factors CS1+CS3, and CS2+CS3 are found in 2 discrete clonal lineages and express the LT1 variant and heat stable toxin (STh). Although they clearly are virulent they neither produce, nor secrete, high amounts of LT toxin. On the other hand ETEC strains expressing LT, STh, CFA/I and LT, STh, CS5+CS6, carry the LT2 variant and produce and secrete significantly more LT toxin. Despite differences in toxin production, LT1 and LT2 are found in ETEC lineages that have managed to spread globally confirming that these variants are important for ETEC virulence. PMID:26939855

  19. The LT1 and LT2 variants of the enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LT) are associated with major ETEC lineages

    PubMed Central

    Joffré, Enrique; Sjöling, Åsa

    2016-01-01

    ABSTRACT The heat-labile toxin (LT) is one of the major virulence factors of enterotoxigenic Escherichia coli (ETEC). We recently described that 20 polymorphic LT variants are present in ETEC strains isolated globally. Two of the variants, LT1 and LT2, are particularly common and we found that they were associated with clonal ETEC lineages that express the colonization factors (CFs), CFA/I, CS1+CS3, CS2+CS3, and CS5+CS6. ETEC expressing these CFs are frequently found among ETEC strains isolated from cases with diarrhea. ETEC expressing the colonization factors CS1+CS3, and CS2+CS3 are found in 2 discrete clonal lineages and express the LT1 variant and heat stable toxin (STh). Although they clearly are virulent they neither produce, nor secrete, high amounts of LT toxin. On the other hand ETEC strains expressing LT, STh, CFA/I and LT, STh, CS5+CS6, carry the LT2 variant and produce and secrete significantly more LT toxin. Despite differences in toxin production, LT1 and LT2 are found in ETEC lineages that have managed to spread globally confirming that these variants are important for ETEC virulence. PMID:26939855

  20. Storm Enhanced Density (SED) plumes as possible suppliers of dayside cleft ion fountain

    NASA Astrophysics Data System (ADS)

    Horwitz, James

    Foster et al. [2002] have observed elevated ionospheric density regions being convected from the subauroral plasmaspheric region toward noon, in association with convection of plasmaspheric tails in the dayside magnetosphere. These so-called Storm Enhanced Density (SED) regions could serve as ionospheric plasma source populations for cleft ion fountain outflows. Here we examine this scenario and employ our fluid-kinetic ionospheric plasma transport code to simulate the entry of a high-density "plasmasphere-like" flux tube entering the cleft region and subjected to an episode of wave-driven transverse ion heating. We find that such pronounced intervals of SED at F-region and topside altitudes passing through regions of CIF processes indeed appear capable of supporting episodes of strong CIF outflows. Foster, J. C., P. J. Erickson, A. J. Coster, J. Goldstein, and F. J. Rich, Ionospheric signatures of plasmaspheric tails, Geophys. Res. Lett., 29(13), 1623, doi:10.1029/2002GL015067, 2002.

  1. Impaired physical function following pediatric LT.

    PubMed

    Feldman, Amy G; Neighbors, Katie; Mukherjee, Shubhra; Rak, Melanie; Varni, James W; Alonso, Estella M

    2016-04-01

    The purpose of this article is to investigate the spectrum of physical function of pediatric liver transplantation (LT) recipients 12-24 months after LT. Review data were collected through the functional outcomes group, an ancillary study of the Studies of Pediatric Liver Transplantation registry. Patients were eligible if they had survived LT by 12-24 months. Children ≥ 8 years and parents completed the Pediatric Quality of Life Inventory™ 4.0 generic core scales, which includes 8 questions assessing physical function. Scores were compared to a matched healthy child population (n = 1658) and between survivors with optimal versus nonoptimal health. A total of 263 patients were included. Median age at transplant and survey was 4.8 years (interquartile range [IQR], 1.3-11.4 years) and 5.9 years (IQR, 2.6-13.1 years), respectively. The mean physical functioning score on child and parent reports were 81.2 ± 17.3 and 77.1 ± 23.7, respectively. Compared to a matched healthy population, transplant survivors and their parents reported lower physical function scores (P < 0.001); 32.9% of patients and 35.0% of parents reported a physical function score <75, which is > 1 standard deviation below the mean of a healthy population. Physical functioning scores were significantly higher in survivors with optimal health than those with nonoptimal health (P < 0.01). There was a significant relationship between emotional functioning and physical functioning scores for LT recipients (r = 0.69; P < 0.001). In multivariate analysis, primary disease, height z score < -1.64 at longterm follow-up (LTF) visit,  > 4 days of hospitalization since LTF visit, and not being listed as status 1 were predictors of poor physical function. In conclusion, pediatric LT recipients 1-2 years after LT and their parents report lower physical function than a healthy population. Findings suggest practitioners need to routinely assess physical function, and

  2. Weak-intensity, basaltic, explosive volcanism: Dynamics of Hawaiian fountains

    NASA Astrophysics Data System (ADS)

    Parcheta, Carolyn

    Hawaiian fountains, typically occurring on basaltic volcanoes, are sustained, weakly-explosive jets of gas and juvenile ejecta. A broad range of Hawaiian fountaining styles occurred during twelve episodes of the Mauna Ulu eruption on Kilauea between May and December 1969. The western episode 1 fissure system is currently well exposed, providing an exclusive opportunity to study processes of low-intensity fissure fountains. Episode 1 fountains occurred along a 5 km long fissure system that exploited the eastern-most kilometer of the Ko'ai fault system. A low, near-continuous, spatter rampart is present on the northern upwind and upslope side of the fissure. Most pyroclastic products, however, fell downwind to the south and little was preserved because of two processes: 1) incorporation of proximal spatter in rheomorphic lava flows 10--20 meters from the vents, and 2) downslope transport of cooler spatter falling on top of these flows >20 meters from vent. There is a clear 'lava-shed' delineation between lava that drained back into the fissure and lava that continued flowing into the flowfield. Vents range in surface geometry from linear--circular, with superimposed irregularity and sinuosity, and range from straight-sided--flaring cross-sectional geometries. Irregularity results from joints in the pre-existing wall rock. Sinuosity results from the local stress field. Geometry of non-flared vents could indicate the true geometry of the dike. Flared vents likely formed through mechanical erosion and thermo-mechanical abrasion. Vent positions along the fissure likely resulted from flow focusing. Uniquely, these vents drained and remain unobstructed (some >100 m depth), despite subsequent nearby eruptive activity. Three vents were imaged .16 m in depth at <4 cm resolution with tripodmounted LiDAR. Textural analyses of pyroclasts from eruptive episodes 2.12 show three distinct degassing and outgassing paths: 1) rapid degassing and quenching with minimal outgassing, 2

  3. Factors influencing the height of Hawaiian lava fountains: implications for the use of fountain height as an indicator of magma gas content

    USGS Publications Warehouse

    Parfitt, E.A.; Wilson, L.; Neal, C.A.

    1995-01-01

    The heights of lava fountains formed in Hawaiian-style eruptions are controlled by magma gas content, volume flux and the amounts of lava re-entrainment and gas bubble coalescence. Theoretical models of lava fountaining are used to analyse data on lava fountain height variations collected during the 1983-1986 Pu'u 'O'o vent of Kilauea volcano, Hawaii. The results show that the variable fountain heights can be largely explained by the impact of variations in volume flux and amount of lava re-entrainment on erupting magmas with a constant gas content of ???0.32 wt.% H2O. However, the gas content of the magma apparently declined by ???0.05 wt.% during the last 10 episodes of the eruption series and this decline is attributed to more extensive pre-eruption degassing due to a shallowing of the sub-vent feeder dike. It is concluded that variations in lava fountain height cannot be simply interpreted as variations in gas content, as has previously been suggested, but that fountain height can still be a useful guide to minimum gas contents. Where sufficient data are available on eruptive volume fluxes and extent of lava entrainment, greatly improved estimates can be made of magma gas content from lava fountain height. ?? 1995 Springer-Verlag.

  4. Phase Separators And Fountain-Effect Pumps For He 11

    NASA Technical Reports Server (NTRS)

    Whitehouse, Paul L.

    1989-01-01

    Fused-glass microchannel arrays for use as HE 11 phase separators and fountain-effect pumps. Microchannel devices for use in low-gravity storage and cooling systems containing superfluid helium. Phase separators and pumps take advantage of thermomechanical effect peculiar to He 11 in restricted spaces. By creating thermal gradient in porous plug, direction of flow reversed, turning phase separator into pump. However, addition of heat disadvantage. Thermal gradient created by using Peltier effect to transfer heat across array, removing heat from He 11 supply and overcoming undesirable addition of heat.

  5. Granular fountains: Convection cascade in a compartmentalized granular gas

    NASA Astrophysics Data System (ADS)

    van der Meer, Devaraj; van der Weele, Ko; Reimann, Peter

    2006-06-01

    This paper extends the two-compartment granular fountain [D. van der Meer, P. Reimann, K. van der Weele, and D. Lohse, Phys. Rev. Lett. 92, 184301 (2004)] to an arbitrary number of compartments: The tendency of a granular gas to form clusters is exploited to generate spontaneous convective currents, with particles going down in the well-filled compartments and going up in the diluted ones. We focus upon the bifurcation diagram of the general K -compartment system, which is constructed using a dynamical flux model and which proves to agree quantitatively with results from molecular dynamics simulations.

  6. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  7. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  8. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  9. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  10. 78 FR 39628 - Endangered and Threatened Wildlife and Plants; Critical Habitat Map for the Fountain Darter

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ...We, the U.S. Fish and Wildlife Service (Service), are correcting the critical habitat map for the fountain darter (Etheostoma fonticola) in our regulations. We are taking this action to ensure regulated entities and the general public have an accurate critical habitat map for the species. This action does not change the designated critical habitat for the fountain...

  11. 21 CFR 1250.85 - Drinking fountains and coolers; ice; constant temperature bottles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... temperature bottles. 1250.85 Section 1250.85 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... Drinking fountains and coolers; ice; constant temperature bottles. (a) Drinking fountains and coolers shall... temperature bottles. (c) Constant temperature bottles and other containers used for storing or...

  12. NIM5 Cs fountain clock and its evaluation

    NASA Astrophysics Data System (ADS)

    Fang, Fang; Li, Mingshou; Lin, Pingwei; Chen, Weiliang; Liu, Nianfeng; Lin, Yige; Wang, Ping; Liu, Kun; Suo, Rui; Li, Tianchu

    2015-08-01

    The cesium fountain primary frequency standard NIM5 has been developed at the National Institute of Metrology in China. The NIM5 loads atoms in an optical molasses from the background Cs vapor directly. Atoms are then cooled to a temperature of about 2 μK and launched to a height of 81 cm. The fringes of the Ramsey pattern have a width of 0.98 Hz. The NIM5 operates for more than 300 d a year, operating nearly continuously for 15 d at a time. By stabilizing the 9.19 GHz microwave frequency to the center of the central Ramsey fringe, a typical fractional frequency instability of 3 × 10-13 (τ/s)-1/2 is obtained when running at high atom density, and a combined uncertainty, including Type A and B uncertainties, is typically 1.6 × 10-15. Comparisons of data between NIM5 and 5 other fountain clocks were carried out in May 2013 via two-way satellite time and frequency transfer (TWSTFT), and the results show good agreement within the uncertainties. Six groups of NIM5 data from January to June 2014 have been published in Circular T 319 and 320.

  13. Low-Light-Shift Cesium Fountain without Mechanical Shutters

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna

    2008-01-01

    A new technique for reducing errors in a laser-cooled cesium fountain frequency standard provides for strong suppression of the light shift without need for mechanical shutters. Because mechanical shutters are typically susceptible to failure after operating times of the order of months, the elimination of mechanical shutters could contribute significantly to the reliability of frequency standards that are required to function continuously for longer time intervals. With respect to the operation of an atomic-fountain frequency standard, the term "light shift" denotes an undesired relative shift in the two energy levels of the atoms (in this case, cesium atoms) in the atomic fountain during interrogation by microwaves. The shift in energy levels translates to a frequency shift that reduces the precision and possibly accuracy of the frequency standard. For reasons too complex to describe within the space available for this article, the light shift is caused by any laser light that reaches the atoms during the microwave- interrogation period, but is strongest for near-resonance light. In the absence of any mitigating design feature, the light shift, expressed as a fraction of the standard fs frequency, could be as large as approx. 2 x 10(exp -11), the largest error in the standard. In a typical prior design, to suppress light shift, the intensity of laser light is reduced during the interrogation period by using a single-pass acoustooptic modulator to deflect the majority of light away from the main optical path. Mechanical shutters are used to block the remaining undeflected light to ensure complete attenuation. Without shutters, this remaining undeflected light could cause a light shift of as much as .10.15, which is unacceptably large in some applications. The new technique implemented here involves additionally shifting the laser wavelength off resonance by a relatively large amount (typically of the order of nanometers) during microwave interrogation. In this

  14. Recirculation of Laser Power in an Atomic Fountain

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna G.; Klipstein, WIlliam M.; Moore, James D.

    2007-01-01

    A new technique for laser-cooling atoms in a cesium atomic fountain frequency standard relies on recirculation of laser light through the atom-collection region of the fountain. The recirculation, accomplished by means of reflections from multiple fixed beam-splitter cubes, is such that each of two laser beams makes three passes. As described below, this recirculation scheme offers several advantages over prior designs, including simplification of the laser system, greater optical power throughput, fewer optical and electrical connections, and simplification of beam power balancing. A typical laser-cooled cesium fountain requires the use of six laser beams arranged as three orthogonal pairs of counter-propagating beams to decelerate the atoms and hold them in a three-dimensional optical trap in vacuum. Typically, these trapping/cooling beams are linearly polarized and are positioned and oriented so that (1) counter-propagating beams in each pair have opposite linear polarizations and (2) three of the six orthogonal beams have the sum of their propagation directions pointing up, while the other three have the sum of their propagation directions pointing down. In a typical prior design, two lasers are used - one to generate the three "up" beams, the other to generate the three "down" beams. For this purpose, the output of each laser is split three ways, then the resulting six beams are delivered to the vacuum system, independently of each other, via optical fibers. The present recirculating design also requires two lasers, but the beams are not split before delivery. Instead, only one "up" beam and one oppositely polarized "down" beam are delivered to the vacuum system, and each of these beams is sent through the collection region three times. The polarization of each beam on each pass through the collection region is set up to yield the same combination of polarization and propagation directions as described above. In comparison with the prior design, the present

  15. Large-eddy simulations of excitation effects on a VTOL upwash fountain

    NASA Astrophysics Data System (ADS)

    Rizk, Magdi H.; Menon, Suresh

    1989-04-01

    The responses of an upwash fountain to various azimuthal and axisymmetric excitations, applied at the exits of its neighboring jets, are investigated. Kinematic arguments are used to determine the interactions of large-scale structures in the fountain and the effects of these interactions on the fountain's characteristics. Numerical simulations of a row of impinging jets, which contain the essential features of twin jets impinging on the ground, are used to simulate the hovering configuration of a vertical takeoff and landing (VTOL) aircraft. The flow is assumed to be governed by the time-dependent, incompressible Navier-Stokes equations. The large-eddy simulation approach is followed. Distinct fountain characteristics are shared among the cases in which azimuthal perturbations are applied at both jet exits in the same direction. These include a high fountain spreading rate, a strong lateral interaction with the neighboring jets, and a weak upload at the aircraft's undersurface. A strong similarity in fountain characteristics also exists for the cases of axisymmetric forcing and azimuthal forcing in opposite directions at the two jet exits. The similar characteristics here include a low fountain spreading rate and a strong upload at the aircraft's undersurface.

  16. Nosocomial outbreak of Pseudomonas aeruginosa associated with a drinking water fountain.

    PubMed

    Costa, D; Bousseau, A; Thevenot, S; Dufour, X; Laland, C; Burucoa, C; Castel, O

    2015-11-01

    Over a four-month period, ten patients were suspected of having acquired nosocomial infection to P. aeruginosa in the ear, nose, and throat department. Environmental and clinical isolates were compared. Only water from a drinking water fountain was contaminated by P. aeruginosa. This isolate and those of three patients had indistinguishable random amplified polymorphic DNA profiles. These patients had serious oncology diseases. The drinking water fountain was used for their alimentation by percutaneous endoscopic gastrostomy and was the origin of the outbreak. Another type of drinking fountain with a terminal ultraviolet treatment was installed, following which no new infections linked to drinking water were identified. PMID:26341271

  17. Recent improvements on the atomic fountain clock at SIOM

    NASA Astrophysics Data System (ADS)

    Du, Yuan-Bo; Wei, Rong; Dong, Ri-Chang; Zou, Fan; Wang, Yu-Zhu

    2015-07-01

    We report the recent advance in our rubidium atomic fountain clock (AFC). The parameters of the Ramsey cavity are optimized by balancing the coupling from the two ports. The temperature control system of the Ramsey interaction region is renovated, and the resonant temperature of the Ramsey cavity is regulated to be slightly above the room temperature. The quality of magnetic environment in the Ramsey interaction region is also improved. A new digital-to-analog converter (DAC) circuit that controls the local oscillator is adopted to decrease the noise of the oven-controlled crystal oscillator output. As a result, the short-term fractional frequency stability of 2.7 × 10-13τ-1/2 and the long-term fractional frequency stability of 1.6 × 10-15 at the average time of 32800 s are achieved. Project supported by the National Natural Science Foundation of China (Grant Nos. 61275204 and 91336105).

  18. Operating characteristics of isocaloric fountain-effect pumps

    NASA Technical Reports Server (NTRS)

    Kittel, Peter

    1988-01-01

    The governing equations of thermomechanical (fountain-effect) pumps are usually given for pumps operating at a constant temperature difference. These are the thermomechanical and mechanocaloric effects in which the pressure head and mass flow are independent of each other. Here, these equations are recast for a pump operating at a constant heat input (isocaloric). This form more closely represents how such pumps are likely to be used. Under these conditions, the pressure head and mass flow are shown to be related. For ideal pumps, the head and flow are related by a universal curve. For real pumps (those that have normal fluid leakage), a family of curves is developed. These curves approach the curve for an ideal pump at high flow rates. The isocaloric equations are also extended to multistage pumps.

  19. On the transition from strombolian to fountaining activity: a thermal energy-based driver

    NASA Astrophysics Data System (ADS)

    Bombrun, Maxime; Spampinato, Letizia; Harris, Andrew; Barra, Vincent; Caltabiano, Tommaso

    2016-02-01

    Since 1999, Mount Etna's (Italy) South-East crater system has been characterised by episodic lava fountaining. Each episode is characterised by initial strombolian activity followed by transition to sustained fountaining to feed high-effusion rate lava flow. Here, we use thermal infrared data recorded by a permanent radiometer station to characterise the transition to sustained fountaining fed by the New South-East crater that developed on the eastern flank of the South-East crater starting from January 2011. We cover eight fountaining episodes that occurred between 2012 and 2013. We first developed a routine to characterise event waveforms apparent in the precursory, strombolian phase. This allowed extraction of a database for thermal energy and waveform shape for 1934 events. We detected between 66 and 650 events per episode, with event durations being between 4 and 55 s. In total, 1508 (78 %) of the events had short waxing phases and dominant waning phases. Event frequency increased as climax was approached. Events had energies of between 3.0 × 106 and 5.8 × 109 J, with rank order analysis indicating the highest possible event energy of 8.1 × 109 J. To visualise the temporal evolution of retrieved parameters during the precursory phase, we applied a dimensionality reduction technique. Results show that weaker events occur during an onset period that forms a low-energy "sink". The transition towards fountaining occurs at 107 J, where subsequent events have a temporal trend towards the highest energies, and where sustained fountaining occurs when energies exceed 109 J. Such an energy-based framework allows researchers to track the evolution of fountaining episodes and to predict the time at which sustained fountaining will begin.

  20. Regular and chaotic dynamics of a fountain in a stratified fluid

    NASA Astrophysics Data System (ADS)

    Druzhinin, O. A.; Troitskaya, Yu. I.

    2012-06-01

    In the present paper, we study by direct numerical simulation (DNS) and theoretical analysis, the dynamics of a fountain penetrating a pycnocline (a sharp density interface) in a density-stratified fluid. A circular, laminar jet flow of neutral buoyancy is considered, which propagates vertically upwards towards the pycnocline level, penetrates a distance into the layer of lighter fluid, and further stagnates and flows down under gravity around the up-flowing core thus creating a fountain. The DNS results show that if the Froude number (Fr) is small enough, the fountain top remains axisymmetric and steady. However, if Fr is increased, the fountain top becomes unsteady and oscillates in a circular flapping (CF) mode, whereby it retains its shape and moves periodically around the jet central axis. If Fr is increased further, the fountain top rises and collapses chaotically in a bobbing oscillation mode (or B-mode). The development of these two modes is accompanied by the generation of different patterns of internal waves (IW) in the pycnocline. The CF-mode generates spiral internal waves, whereas the B-mode generates IW packets with a complex spatial distribution. The dependence of the amplitude of the fountain-top oscillations on Fr is well described by a Landau-type two-mode-competition model.

  1. Regular and chaotic dynamics of a fountain in a stratified fluid.

    PubMed

    Druzhinin, O A; Troitskaya, Yu I

    2012-06-01

    In the present paper, we study by direct numerical simulation (DNS) and theoretical analysis, the dynamics of a fountain penetrating a pycnocline (a sharp density interface) in a density-stratified fluid. A circular, laminar jet flow of neutral buoyancy is considered, which propagates vertically upwards towards the pycnocline level, penetrates a distance into the layer of lighter fluid, and further stagnates and flows down under gravity around the up-flowing core thus creating a fountain. The DNS results show that if the Froude number (Fr) is small enough, the fountain top remains axisymmetric and steady. However, if Fr is increased, the fountain top becomes unsteady and oscillates in a circular flapping (CF) mode, whereby it retains its shape and moves periodically around the jet central axis. If Fr is increased further, the fountain top rises and collapses chaotically in a bobbing oscillation mode (or B-mode). The development of these two modes is accompanied by the generation of different patterns of internal waves (IW) in the pycnocline. The CF-mode generates spiral internal waves, whereas the B-mode generates IW packets with a complex spatial distribution. The dependence of the amplitude of the fountain-top oscillations on Fr is well described by a Landau-type two-mode-competition model. PMID:22757523

  2. Scanning Electron Microscopy and Petrography of Glassy Particles Produced by Lava Fountain Eruptions. Ph.D. Thesis - Final Report

    NASA Technical Reports Server (NTRS)

    Ladle, G. H.

    1978-01-01

    A conceptual model of a lava fountain consists of a vent, spatter ramparts, fountain column, downwind plume and associated pumice deposits. Glassy particles produced by lava fountain eruptions consist primarily of sideromelane glass and minor to moderate amounts of vesicles and crystals. Particles are classified on the basis of morphology as: (1) spherical, (2) elongate, (3) glass-coated mineral grain, (4) shard, (5) reticulite, (6) composite particle, and (7) lithic fragment.

  3. Open-path FTIR spectroscopy of magma degassing processes during eight lava fountains on Mount Etna

    NASA Astrophysics Data System (ADS)

    La Spina, Alessandro; Burton, Mike; Allard, Patrick; Alparone, Salvatore; Murè, Filippo

    2016-04-01

    In June-July 2001 a series of 16 discrete lava fountain paroxysms occurred at the Southeast summit crater (SEC) of Mount Etna, preceding a 28-day long violent flank eruption. Each paroxysm was preceded by lava effusion, growing seismic tremor and a crescendo of Strombolian explosive activity culminating into powerful lava fountaining up to 500m in height. During 8 of these 16 events we could measure the chemical composition of the magmatic gas phase (H2O, CO2, SO2, HCl, HF and CO), using open-path Fourier transform infrared (OP-FTIR) spectrometry at ˜1-2km distance from SEC and absorption spectra of the radiation emitted by hot lava fragments. We show that each fountaining episode was characterized by increasingly CO2-rich gas release, with CO2/SO2and CO2/HCl ratios peaking in coincidence with maxima in seismic tremor and fountain height, whilst the SO2/HCl ratio showed a weak inverse relationship with respect to eruption intensity. Moreover, peak values in both CO2/SO2ratio and seismic tremor amplitude for each paroxysm were found to increase linearly in proportion with the repose interval (2-6 days) between lava fountains. These observations, together with a model of volatile degassing at Etna, support the following driving process. Prior to and during the June-July 2001 lava fountain sequence, the shallow (˜2km) magma reservoir feeding SEC received an increasing influx of deeply derived carbon dioxide, likely promoted by the deep ascent of volatile-rich primitive basalt that produced the subsequent flank eruption. This CO2-rich gas supply led to gas accumulation and overpressure in SEC reservoir, generating a bubble foam layer whose periodical collapse powered the successive fountaining events. The anti-correlation between SO2/HCl and eruption intensity is best explained by enhanced syn-eruptive degassing of chlorine from finer particles produced during more intense magma fragmentation.

  4. Open-path FTIR spectroscopy of magma degassing processes during eight lava fountains on Mount Etna

    NASA Astrophysics Data System (ADS)

    La Spina, Alessandro; Burton, Mike; Allard, Patrick; Alparone, Salvatore; Muré, Filippo

    2015-03-01

    In June-July 2001 a series of 16 discrete lava fountain paroxysms occurred at the Southeast summit crater (SEC) of Mount Etna, preceding a 28-day long violent flank eruption. Each paroxysm was preceded by lava effusion, growing seismic tremor and a crescendo of Strombolian explosive activity culminating into powerful lava fountaining up to 500 m in height. During 8 of these 16 events we could measure the chemical composition of the magmatic gas phase (H2O, CO2, SO2, HCl, HF and CO), using open-path Fourier transform infrared (OP-FTIR) spectrometry at ∼1-2 km distance from SEC and absorption spectra of the radiation emitted by hot lava fragments. We show that each fountaining episode was characterized by increasingly CO2-rich gas release, with CO2/SO2 and CO2/HCl ratios peaking in coincidence with maxima in seismic tremor and fountain height, whilst the SO2/HCl ratio showed a weak inverse relationship with respect to eruption intensity. Moreover, peak values in both CO2/SO2 ratio and seismic tremor amplitude for each paroxysm were found to increase linearly in proportion with the repose interval (2-6 days) between lava fountains. These observations, together with a model of volatile degassing at Etna, support the following driving process. Prior to and during the June-July 2001 lava fountain sequence, the shallow (∼2 km) magma reservoir feeding SEC received an increasing influx of deeply derived carbon dioxide, likely promoted by the deep ascent of volatile-rich primitive basalt that produced the subsequent flank eruption. This CO2-rich gas supply led to gas accumulation and overpressure in SEC reservoir, generating a bubble foam layer whose periodical collapse powered the successive fountaining events. The anti-correlation between SO2/HCl and eruption intensity is best explained by enhanced syn-eruptive degassing of chlorine from finer particles produced during more intense magma fragmentation.

  5. Star Trek's Lt. Uhura's Warp-Speed Visit to Dryden

    NASA Video Gallery

    Actress Nichelle Nichols warped to many worlds as Lt. Uhura in the 1960s Star Trek TV show. However, her real-life adventures have taken her to where no one has gone before in advocacy for NASA and...

  6. Copper dimer interactions on a thermomechanical superfluid {sup 4}He fountain

    SciTech Connect

    Popov, Evgeny; Eloranta, Jussi

    2015-05-28

    Laser induced fluorescence imaging and frequency domain excitation spectroscopy of the copper dimer (B{sup 1}Σ{sub g}{sup +}←X{sup 1}Σ{sub u}{sup +}) in thermomechanical helium fountain at 1.7 K are demonstrated. The dimers penetrate into the fountain provided that their average propagation velocity is ca. 15 m/s. This energy threshold is interpreted in terms of an imperfect fountain liquid-gas interface, which acts as a trap for low velocity dimers. Orsay-Trento density functional theory calculations for superfluid {sup 4}He are used to characterize the dynamics of the dimer solvation process into the fountain. The dimers first accelerate towards the fountain surface and once the surface layer is crossed, they penetrate into the liquid and further slow down to Landau critical velocity by creating a vortex ring. Theoretical lineshape calculations support the assignment of the experimentally observed bands to Cu{sub 2} solvated in the bulk liquid. The vibronic progressions are decomposed of a zero-phonon line and two types of phonon bands, which correlate with solvent cavity interface compression (t < 200 fs) and expansion (200 < t < 500 fs) driven by the electronic excitation. The presented experimental method allows to perform molecular spectroscopy in bulk superfluid helium where the temperature and pressure can be varied.

  7. Balancing bulk gas accumulation and gas output before and during lava fountaining episodes at Mt. Etna

    NASA Astrophysics Data System (ADS)

    Carbone, Daniele; Zuccarello, Luciano; Messina, Alfio; Scollo, Simona; Rymer, Hazel

    2015-12-01

    We focus on a sequence of 9 lava fountains from Etna that occurred in 2011, separated by intervals of 5 to 10 days. Continuous measurements allowed to discover the occurrence of gravity decreases before the onset of most fountaining episodes. We propose that the gravity changes are due to the pre-fountaining accumulation of a foam layer at shallow levels in the plumbing system of the volcano. Relying on the relationship between amount of gas trapped in the foam and amount of gas emitted during each episode, we develop a conceptual model of the mechanism controlling the passage from Strombolian to lava fountaining activity. Gas leakage from the foam layer during the late stages of its accumulation increases the gas volume fraction at upper levels, thus inducing a decrease of the magma-static pressure in the trapping zone and a further growth of the foam. This feedback mechanism eventually leads to the collapse of the foam layer and to the onset of lava fountaining. The possibility to detect the development of a foam layer at depth and to set quantitative constraints on the amount of trapped gas is important because of the implications for forecasting explosive eruptions and predicting their intensity.

  8. Balancing bulk gas accumulation and gas output before and during lava fountaining episodes at Mt. Etna

    PubMed Central

    Carbone, Daniele; Zuccarello, Luciano; Messina, Alfio; Scollo, Simona; Rymer, Hazel

    2015-01-01

    We focus on a sequence of 9 lava fountains from Etna that occurred in 2011, separated by intervals of 5 to 10 days. Continuous measurements allowed to discover the occurrence of gravity decreases before the onset of most fountaining episodes. We propose that the gravity changes are due to the pre-fountaining accumulation of a foam layer at shallow levels in the plumbing system of the volcano. Relying on the relationship between amount of gas trapped in the foam and amount of gas emitted during each episode, we develop a conceptual model of the mechanism controlling the passage from Strombolian to lava fountaining activity. Gas leakage from the foam layer during the late stages of its accumulation increases the gas volume fraction at upper levels, thus inducing a decrease of the magma-static pressure in the trapping zone and a further growth of the foam. This feedback mechanism eventually leads to the collapse of the foam layer and to the onset of lava fountaining. The possibility to detect the development of a foam layer at depth and to set quantitative constraints on the amount of trapped gas is important because of the implications for forecasting explosive eruptions and predicting their intensity. PMID:26656099

  9. Balancing bulk gas accumulation and gas output before and during lava fountaining episodes at Mt. Etna.

    PubMed

    Carbone, Daniele; Zuccarello, Luciano; Messina, Alfio; Scollo, Simona; Rymer, Hazel

    2015-01-01

    We focus on a sequence of 9 lava fountains from Etna that occurred in 2011, separated by intervals of 5 to 10 days. Continuous measurements allowed to discover the occurrence of gravity decreases before the onset of most fountaining episodes. We propose that the gravity changes are due to the pre-fountaining accumulation of a foam layer at shallow levels in the plumbing system of the volcano. Relying on the relationship between amount of gas trapped in the foam and amount of gas emitted during each episode, we develop a conceptual model of the mechanism controlling the passage from Strombolian to lava fountaining activity. Gas leakage from the foam layer during the late stages of its accumulation increases the gas volume fraction at upper levels, thus inducing a decrease of the magma-static pressure in the trapping zone and a further growth of the foam. This feedback mechanism eventually leads to the collapse of the foam layer and to the onset of lava fountaining. The possibility to detect the development of a foam layer at depth and to set quantitative constraints on the amount of trapped gas is important because of the implications for forecasting explosive eruptions and predicting their intensity. PMID:26656099

  10. THE FIRST ''WATER FOUNTAIN'' COLLIMATED OUTFLOW IN A PLANETARY NEBULA

    SciTech Connect

    Gómez, José F.; Miranda, Luis F.; Guerrero, Martín A.; Rizzo, J. Ricardo; García-García, Enrique; Green, James A.; Uscanga, Lucero; Ramos-Larios, Gerardo

    2015-02-01

    ''Water fountains'' (WFs) are evolved objects showing high-velocity, collimated jets traced by water maser emission. Most of them are in the post-asymptotic giant branch (post-AGB) and they may represent one of the first manifestations of collimated mass loss in evolved stars. We present water maser, carbon monoxide, and mid-infrared spectroscopic data (obtained with the Australia Telescope Compact Array, Herschel Space Observatory, and the Very Large Telescope, respectively) toward IRAS 15103–5754, a possible planetary nebula (PN) with WF characteristics. Carbon monoxide observations show that IRAS 15103–5754 is an evolved object, while the mid-IR spectrum displays unambiguous [Ne II] emission, indicating that photoionization has started and thus, its nature as a PN is confirmed. Water maser spectra show several components spreading over a large velocity range (≅ 75 km s{sup –1}) and tracing a collimated jet. This indicates that the object is a WF, the first WF known that has already entered the PN phase. However, the spatial and kinematical distribution of the maser emission in this object are significantly different from those in other WFs. Moreover, the velocity distribution of the maser emission shows a ''Hubble-like'' flow (higher velocities at larger distances from the central star), consistent with a short-lived, explosive mass-loss event. This velocity pattern is not seen in other WFs (which are presumably in earlier evolutionary stages). We therefore suggest that we are witnessing a fundamental change of mass-loss processes in WFs, with water masers being pumped by steady jets in post-AGB stars, but tracing explosive/ballistic events as the object enters the PN phase.

  11. The First "Water Fountain" Collimated Outflow in a Planetary Nebula

    NASA Astrophysics Data System (ADS)

    Gómez, José F.; Suárez, Olga; Bendjoya, Philippe; Rizzo, J. Ricardo; Miranda, Luis F.; Green, James A.; Uscanga, Lucero; García-García, Enrique; Lagadec, Eric; Guerrero, Martín A.; Ramos-Larios, Gerardo

    2015-02-01

    "Water fountains" (WFs) are evolved objects showing high-velocity, collimated jets traced by water maser emission. Most of them are in the post-asymptotic giant branch (post-AGB) and they may represent one of the first manifestations of collimated mass loss in evolved stars. We present water maser, carbon monoxide, and mid-infrared spectroscopic data (obtained with the Australia Telescope Compact Array, Herschel Space Observatory, and the Very Large Telescope, respectively) toward IRAS 15103-5754, a possible planetary nebula (PN) with WF characteristics. Carbon monoxide observations show that IRAS 15103-5754 is an evolved object, while the mid-IR spectrum displays unambiguous [Ne II] emission, indicating that photoionization has started and thus, its nature as a PN is confirmed. Water maser spectra show several components spreading over a large velocity range (sime 75 km s-1) and tracing a collimated jet. This indicates that the object is a WF, the first WF known that has already entered the PN phase. However, the spatial and kinematical distribution of the maser emission in this object are significantly different from those in other WFs. Moreover, the velocity distribution of the maser emission shows a "Hubble-like" flow (higher velocities at larger distances from the central star), consistent with a short-lived, explosive mass-loss event. This velocity pattern is not seen in other WFs (which are presumably in earlier evolutionary stages). We therefore suggest that we are witnessing a fundamental change of mass-loss processes in WFs, with water masers being pumped by steady jets in post-AGB stars, but tracing explosive/ballistic events as the object enters the PN phase.

  12. Loading a fountain clock with an enhanced low-velocity intense source of atoms

    NASA Astrophysics Data System (ADS)

    Dobrev, G.; Gerginov, V.; Weyers, S.

    2016-04-01

    We present experimental work for improved atom loading in the optical molasses of a cesium fountain clock, employing a low-velocity intense source of atoms [Lu et al., Phys. Rev. Lett 77, 3331 (1996), 10.1103/PhysRevLett.77.3331], which we modify by adding a dark-state pump laser. With this modification the atom source has a mean flux of 4 ×108 atoms/s at a mean atom velocity of 8.6 m/s. Compared to fountain operation using background gas loading, we achieve a significant increase of the loaded and detected atom number by a factor of 40. Operating the fountain clock with a total number of detected atoms Nat=2.9 ×106 in the quantum projection noise-limited regime, a frequency instability σy(1 s ) =2.7 ×10-14 is demonstrated.

  13. Discrete blasts in granular material yield two-stage process of cavitation and granular fountaining

    NASA Astrophysics Data System (ADS)

    Andrews, Robin; White, James; Dürig, Tobi; Zimanowski, Bernd

    2014-05-01

    A discrete blast within granular material, such as a single subterranean explosion within a debris-filled diatreme structure, is typically considered to produce a single uprush of material. Our experiments demonstrate that apparent "debris jet deposits" can be formed by a two-stage process of cavitation and subsequent granular fountaining. Bench-scale experiments reported here demonstrate that for a range of overpressures and depths, individual, discrete, buried gas blasts open space and expel particles from the blast site in two largely decoupled stages. Expanding gas initially pierces material nearest the blast source to open a cavity above it; then a fountain of grains rises from the source into the cavity. This staged motion dynamically segregates source grains from host-material grains, and the rates of cavity opening vs. fountain rise show a power-law decay relationship with initial pressure. Our experimental analysis has implications for maar-diatreme systems, field-scale detonation experiments, and underground nuclear testing.

  14. Discrete blasts in granular material yield two-stage process of cavitation and granular fountaining

    NASA Astrophysics Data System (ADS)

    Andrews, Robin G.; White, James D. L.; Dürig, Tobi; Zimanowski, Bernd

    2014-01-01

    A discrete blast within granular material, such as a single subterranean explosion within a debris-filled diatreme structure, is typically considered to produce a single uprush of material. Our experiments demonstrate that apparent "debris jet deposits" can be formed by a two-stage process of cavitation and subsequent granular fountaining. Bench-scale experiments reported here demonstrate that for a range of overpressures and depths, individual, discrete, buried gas blasts open space and expel particles from the blast site in two largely decoupled stages. Expanding gas initially pierces material nearest the blast source to open a cavity above it; then a fountain of grains rises from the source into the cavity. This staged motion dynamically segregates source grains from host-material grains, and the rates of cavity opening versus fountain rise show a power law decay relationship with initial pressure. Our experimental analysis has implications for maar-diatreme systems, field-scale detonation experiments, and underground nuclear testing.

  15. Ground water in Fountain and Jimmy Camp Valleys, El Paso County, Colorado with a section on Computations of drawdowns caused by the pumping of wells in Fountain Valley

    USGS Publications Warehouse

    Jenkins, Edward D.; Glover, Robert E.

    1964-01-01

    The part of Fountain Valley considered in this report extends from Colorado Springs to the Pueblo County line. It is 23 miles long and has an area of 26 square miles. The part of Jimmy Camp Valley discussed is 11 miles long and has an area of 9 square miles. The topography is characterized by level flood plains and alluvial terraces that parallel the valley and by rather steep hills along the valley sides. The climate is semiarid, average annual precipitation being about 13 inches. Farming and stock raising are the principal occupations in the valleys; however, some of the agricultural land near Colorado Springs is being used for housing developments. The Pierre Shale and alluvium underlie most of the area, and mesa gravel caps the shale hills adjacent to Fountain Valley. The alluvium yields water to domestic, stock, irrigation, and public-supply wells and is capable of yielding large quantities of water for intermittent periods. Several springs issue along the sides of the valley at the contact of the mesa gravel and the underlying Pierre Shale. The water table ranges in depth from less than 10 feet along the bottom lands to about 80 feet along the sides of the valleys; the saturated thickness ranges from less than a foot to about 50 feet. The ground-water reservoir in Fountain Valley is recharged by precipitation that falls within the area, by percolation from Fountain Creek, which originates in the Pikes Peak, Monument Valley, and Rampart Range areas, and by seepage from irrigation water. This reservoir contains about 70,000 acre-feet of ground water in storage. The ground-water reservoir in Jimmy Camp Valley is recharged from precipitation that falls within the area, by percolation from Jimmy Camp Creek during periods of streamflow, and by seepage from irrigation water. The Jimmy Camp ground-water reservoir contains about 25,000 acre-feet of water in storage. Ground water is discharged from the area by movement to the south, by evaporation and transpiration in

  16. Perceptions of Tap Water and School Water Fountains and Association with Intake of Plain Water and Sugar-Sweetened Beverages

    ERIC Educational Resources Information Center

    Onufrak, Stephen J.; Park, Sohyun; Sharkey, Joseph R.; Merlo, Caitlin; Dean, Wesley R.; Sherry, Bettylou

    2014-01-01

    Background: Little is known regarding youth perceptions of tap water and school water fountains and how these relate to water and sugar-sweetened beverage (SSB) intake. Methods: We used national 2010 YouthStyles data to assess perceptions of tap water and school water fountains and associations with water and SSB intake. Results: Nearly 1 in 5…

  17. Contrasting patterns of vesiculation in low, intermediate, and high Hawaiian fountains: A case study of the 1969 Mauna Ulu eruption

    NASA Astrophysics Data System (ADS)

    Parcheta, C. E.; Houghton, B. F.; Swanson, D. A.

    2013-04-01

    Hawaiian-style eruptions, or Hawaiian fountains, typically occur at basaltic volcanoes and are sustained, weakly explosive jets of gas and dominantly coarse, juvenile ejecta (dense spatter to delicate reticulite). Almost the entire range of styles and mass eruption rates within Hawaiian fountaining occurred during twelve fountaining episodes recorded at Mauna Ulu, Kīlauea between May and December 1969. Such diversity in intensity and style is controlled during magma ascent by many processes that can be constrained by the size and shape of vesicles in the 1969 pyroclasts. This paper describes pyroclast vesicularity from high, intermediate, and low fountaining episodes with eruption rates from 0.05 to 1.3 × 106 m3 h- 1. As each eruptive episode progressed, magma ascent slowed in and around the vent system, offering extended time for bubbles to grow and coalesce. Late ejected pyroclasts are thus characterized by populations of fewer and larger vesicles with relaxed shapes. This progression continued in the intervals between episodes after termination of fountain activity. The time scale for this process of shallow growth, coalescence and relaxation of bubbles is typically tens of hours. Rims and cores of pumiceous pyroclasts from moderate to high fountaining episodes record a second post-fragmentation form of vesicle maturation. Partially thermally insulated pyroclasts can have internal bubble populations evolve more dynamically with continued growth and coalescence, on a time scale of only minutes, during transport in the fountains. Reticulite, which formed in a short-lived fountain 540 m in height, underwent late, short-lived bubble nucleation followed by rapid growth of a uniform bubble population in a thermally insulated fountain, and quenched at the onset of permeability before significant coalescence. These contrasting patterns of shallow degassing and outgassing were the dominant controls in determining both the form and duration of fountaining episodes at

  18. SODA FOUNTAIN-LUNCHEONETTE EQUIPMENT AND APPURTENANCES. NATIONAL SANITATION FOUNDATION STANDARD NO. 1.

    ERIC Educational Resources Information Center

    National Sanitation Foundation, Ann Arbor, MI.

    THIS STANDARD OF SODA FOUNTAIN-LUNCHEONETTE EQUIPMENT IS THE FIRST IN A SERIES OF NATIONAL SANITATION FOUNDATION STANDARDS. THESE STANDARDS ARE ISSUED IN RECOGNITION OF THE LONG FELT NEED FOR A COMMON UNDERSTANDING OF THE PROBLEMS OF SANITATION INVOLVING INDUSTRIAL AND ADMINISTRATIVE HEALTH OFFICIALS WHOSE OBLIGATION IT IS TO ENFORCE REGULATIONS.…

  19. Status and prospect of the Swiss continuous Cs fountain FoCS-2

    NASA Astrophysics Data System (ADS)

    Jallageas, A.; Devenoges, L.; Petersen, M.; Morel, J.; Bernier, L.-G.; Thomann, P.; Südmeyer, T.

    2016-06-01

    The continuous cesium fountain clock FoCS-2 at METAS presents many unique characteristics and challenges in comparison with standard pulsed fountain clocks. For several years FoCS-2 was limited by an unexplained frequency sensitivity on the velocity of the atoms, in the range of 140 • 10-15. Recent experiments allowed us to identify the origin of this problem as undesirable microwave surface currents circulating on the shield of the coaxial cables that feed the microwave cavity. A strong reduction of this effect was obtained by adding microwave absorbing coatings on the coaxial cables and absorbers inside of the vacuum chamber. This breakthrough opens the door to a true metrological validation of the fountain. A series of simulation tools have already been developed and proved their efficiency in the evaluation of some of the uncertainties of the continuous fountain. With these recent improvements, we are confident in the future demonstration of an uncertainty budget at the 10-15 level and below.

  20. Operation Facelift: Cover Makeovers Can Be the Fountain of Youth for Many Titles

    ERIC Educational Resources Information Center

    Jones, Leigh Ann

    2009-01-01

    Aging covers and those that miss their mark and lead to sluggish sales are often targeted for makeovers, many times with good results. Up to 75 percent of Viking's books get redesigned, says Assistant Art Director Jim Hoover, because the publisher sees it as a chance to reintroduce a book to the market. Makeovers are considered the fountain of…

  1. Lava Fountaining Discharge Regime driven by Slug-to-Churn Flow Transition. (Invited)

    NASA Astrophysics Data System (ADS)

    Ripepe, M.; Pioli, L.; Marchetti, E.; Ulivieri, G.

    2013-12-01

    Lava fountaining episodes at Etna volcano appear characterized by the transition between Strombolian and Hawaiian end-member eruptive styles. There is no evidence for this transition in the seismic (i.e. seismic tremor) signal. However, infrasonic records provide unprecedented evidence on this flow transition. Each eruptive episode is characterized by distinctive common trend in the amplitude, waveform and frequency content of the infrasonic wavefield, which evidences the shift from discrete, and transient, strombolian to sustained, and oscillatory, lava fountain dynamics. Large scale experiments on the dynamics of two-phase flow of basaltic magmas show how the transition between different regimes mainly depends on gas volume flow, which in turn controls pressure distribution within the conduit and also magma vesicularity. In particular, while regular large bubble bursting is associated with slug flow regime, large amplitude and low frequency column oscillations are associated with churn flow. In large pipes, transition from slug to churn flow regime is independent on conduit diameter and it is reached at high superficial gas velocity. Lava fountaining episodes at Etna can be thus interpreted as induced by the transition from the slug (discrete strombolian) to churn flow (sustained lava fountain) regimes that is reflecting an increase in the gas discharge rate. Based on laboratory experiments, we calculate that transition between these two end-member explosive regimes at Etna occurs when gas superficial velocity is 76 m/s for near-the-vent stagnant magma conditions.

  2. Simplified thermodynamic functions for vapor-liquid phase separation and fountain effect pumps

    NASA Technical Reports Server (NTRS)

    Yuan, S. W. K.; Hepler, W. A.; Frederking, T. H. K.

    1984-01-01

    He-4 fluid handling devices near 2 K require novel components for non-Newtonian fluid transport in He II. Related sizing of devices has to be based on appropriate thermophysical property functions. The present paper presents simplified equilibrium state functions for porous media components which serve as vapor-liquid phase separators and fountain effect pumps.

  3. 16. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. SHEET 3 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  4. 18. EXISTING FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. EXISTING FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. Sheet 5 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  5. 17. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. WEST ELEVATION. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. Sheet 4 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  6. 15. SECOND FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. SECOND FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. SHEET 2 OF 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  7. 14. FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. FIRST FLOOR PLAN. MONOMOY POINT LT. STATION, MASS., SHOWING PROPOSED ALTERATION AND IMPROVEMENT OF DWELLING. No. 1343. SHEET 1 of 5. July 1899. - Monomoy Point Light Station, Approximately 3500 feet Northeast Powder Hole Pond, Monomoy National Wildlife Refuge, Chatham, Barnstable County, MA

  8. DEMONSTRATION BULLETIN: LOW TEMPERATURE THERMAL TREATMENT (LT3®) SYSTEM

    EPA Science Inventory

    The Roy F. Weston, Inc. (Weston) low temperature thermal treatment (LT3®) system thermally desorbs organic compounds from contaminated soil without heating the soil to combustion temperatures. The transportable system is comprised of equipment assembled on thre...

  9. Unexpected hazards from tephra fallouts at Mt Etna: The 23 November 2013 lava fountain

    NASA Astrophysics Data System (ADS)

    Andronico, Daniele; Scollo, Simona; Cristaldi, Antonio

    2015-10-01

    Hundreds of paroxysmal episodes and a few long-lasting ash-emissions eruptions make Mt. Etna, in Italy, one of the most productive basaltic volcanoes in the world over recent years. This frequent explosive activity certainly gives volcanologists plenty of stimulating scientific material for study. Volcanic hazard from tephra fallout associated with lava fountains is still an issue that has not been fully assessed, albeit having to face this scenario several times in 2013. The 23 November 2013 lava fountain was exceptionally intense despite the short duration of the paroxysmal phase (< 1 h). Abundant decimetric-sized bombs fell within the first 5-6 km from the vent, and a macroscopically thicker and coarser tephra deposit than usual formed between 5 and 25 km; in addition, ash was reported to fall up to distances of 400 km. The analysis of fallout deposit provided a total erupted mass of 1.3 ± 1.1 × 109 kg (for a mass eruption rate of 4.5 ± 3.6 × 105 kg/s), in agreement with the value of 2.4 × 109 kg estimated by modeling. Grain-size distribution of samples shows poor sorting at least up to 25 km from the vent. By comparing dispersal, sedimentological features and physical parameters of the fallout deposit with other lava fountains of Etna, the 23 November 2013 episode may well be one of the largest events of the 21st Century in terms of eruption column height, total erupted mass and mass eruption rate. Furthermore, the impact of tephra on the territory was so high as to make it opportune to introduce a distinction, within the class of lava fountains, between small- and large-scale episodes. This classification can be a starting point for hazard assessment and help prevent the hazards from large-scale lava fountains at Etna in the future.

  10. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  11. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  12. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  13. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  14. 7 CFR 28.525 - Symbols and code numbers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... grade Symbol Code No. Good Middling GM 11 Strict Middling SM 21 Middling Mid 31 Strict Low Middling SLM... Middling Light Spotted SLM Lt Sp 42 Low Middling Light Spotted LM Lt Sp 52 Stict Good Ordinary Light... Sp 33 Strict Low Middling Spotted SLM Sp 43 Low Middling Spotted LM Sp 53 Strict Good...

  15. Dynamic Fluid-Kinetic (DyFK) Simulations of Storm-Enhanced Density Supply of Cleft Ion Fountain Outflows

    NASA Astrophysics Data System (ADS)

    Horwitz, J. L.; Zeng, W.; Foster, J. C.; Strangeway, R. J.; Adrian, M. L.; Moore, T. E.

    2008-12-01

    Elevated ionospheric density regions frequently appear to be convected from the subauroral plasmaspheric region toward noon, in association with convection of plasmaspheric tails in the dayside magnetosphere, typically during large geomagnetic storms. In this presentation, we explore the possibility that these Storm Enhanced Density (SED) regions could provide ionospheric plasma source populations for cleft ion fountain outflows. We use our Dynamic Fluid Kinetic (DyFK) code to simulate the entry of a high-density "plasmasphere-like" flux tube entering the cleft region and subjected to an episode of wave-driven transverse ion heating. The results of including different proportions of SED and soft electron precipitation levels, together with transverse ion heating effects on the resulting outflows, will be presented, including the O+ and H+ ion density and related parameter profiles for the simulated SED involved events. We will also compare these modeling results with SED-outflow observations from GPS TEC, and the FAST and IMAGE spacecraft. Foster, J. C., P. J. Erickson, A. J. Coster, J. Goldstein, and F. J. Rich, Ionospheric signatures of plasmaspheric tails, Geophys. Res. Lett., 29(13), 1623, doi:10.1029/2002GL015067, 2002.

  16. Doppler radar retrievals from lava fountaining paroxysms generating tephra plumes at Mt. Etna

    NASA Astrophysics Data System (ADS)

    Valentin, Freret-Lorgeril; Franck, Donnadieu; Mauro, Coltelli; Simona, Scollo; Patrick, Fréville; Claude, Hervier; Michele, Prestifilippo

    2016-04-01

    Etna volcano is one of the most active European volcanoes. Between January 2011 and December 2013, a new crater called the New South East Crater (NSEC) was built during 46 eruptive episodes characterized by lava fountaining generating tephra plumes that reached up to 10 km (a.s.l). A 23 cm-wavelength Doppler radar (VOLDORAD 2B), located about 3 km from NSEC at the Montagnola station and integrated into the INGV-OE instrumental network, has been continuously monitoring the explosive activity of Mt. Etna's summit craters since 2009. We have studied these paroxysms by analyzing the radar echoes and Doppler signals coming from adjacent volumes of the fixed beam probing the lava fountains close to the eruptive crater, in combination with thermal and visible imagery. The range gating (150 m-deep probed volumes along-beam) allows us to discriminate the active summit craters and to roughly estimate the lava fountain width. The backscattered power, which is related to the erupted tephra mass load in the beam, and Doppler velocities help to mark the transition from Strombolian activity to lava fountaining, providing onset and end times of the fountain. Both radar parameters directly provide a proxy for the mass eruption rate, which is found to follow the time variations of tephra plume height. Oscillations of the echo power during lava fountaining indicate a pulsatile behavior likely originating in the magmatic conduit or deeper reservoir. Ejection velocities retrieved from positive along-beam velocities measured near the emission source, are found to range from 140 to almost 350 m/s during the climax. Maximum along-beam Doppler velocity components from fallouts allow us to infer maximum particle sizes (pluri-decimetric) in agreement with field observations. The mode of power spectral distribution could further be used to constrain the mean diameter of proximal fallout. A reliable quantification of the source mass loading parameters requires more stringent constraints on the

  17. SEU design consideration for MESFETs on LT GaAs

    SciTech Connect

    Weatherford, T.R.; Radice, R.; Eskins, D.

    1997-12-01

    Computer simulation results are reported on transistor design and single-event charge collection modeling of metal-semiconductor field effect transistors (MESFETs) fabricated in the Vitesse H-GaAsIII{reg_sign} process on Low Temperature grown (LT) GaAs epitaxial layers. Tradeoffs in Single Event Upset (SEU) immunity and transistor design are discussed. Effects due to active loads and diffusion barriers are examined.

  18. Sensitive CO and 13CO survey of water fountain stars. Detections towards IRAS 18460-0151 and IRAS 18596+0315

    NASA Astrophysics Data System (ADS)

    Rizzo, J. R.; Gómez, J. F.; Miranda, L. F.; Osorio, M.; Suárez, O.; Durán-Rojas, M. C.

    2013-12-01

    Context. Water fountain stars represent a stage between the asymptotic giant branch (AGB) and planetary nebulae phases, when the mass loss changes from spherical to bipolar. These types of evolved objects are characterized by high-velocity jets in the 22 GHz water maser emission. Aims: The objective of this work is to detect and study in detail the circumstellar gas in which the bipolar outflows are emerging. The detection and study of thermal lines may help in understanding the nature and physics of the envelopes in which the jets are developing. Methods: We surveyed the CO and 13CO line emission towards a sample of ten water fountain stars through observing the J = 1 → 0 and 2 → 1 lines of CO and 13CO, using the 30 m IRAM radio-telescope at Pico Veleta. All the water fountains visible from the observatory were surveyed. Results: Most of the line emission arises from foreground or background Galactic clouds, and we had to thoroughly analyse the spectra to unveil the velocity components related to the stars. In two sources, IRAS 18460-0151 and IRAS 18596+0315, we identified wide velocity components with a width of 35 - 40 km s-1 that are centred at the stellar velocities. These wide components can be associated with the former AGB envelope of the progenitor star. A third case, IRAS 18286-0959, is reported as tentative; in this case a pair of narrow velocity components, symmetrically located with respect to the stellar velocity, have been discovered. We also modelled the line emission using an LVG code and derived some global physical parameters, which allowed us to discuss the possible origin of this gas in relation to the known bipolar outflows. For IRAS 18460-0151 and IRAS 18596+0315, we derived molecular masses close to 0.2 M⊙, mean densities of 104 cm-3, and mass-loss rates of 10-4 M⊙ yr-1. The kinetic temperatures are rather low, between 10 and 50 K in both cases, which suggests that the CO emission is arising from the outer and cooler regions of the

  19. Light shift measurements in a Cesium Fountain without the use of mechanical shutters

    NASA Technical Reports Server (NTRS)

    Tjoelker, Robert L.; Enzer, D. G.; Klipstein, W. M.

    2005-01-01

    We present measurements confirming operation of a cesium fountain frequency standard with light shift below 10^-15 (and with evidence suggesting it is several orders of magnitude below this level) but without the use of mechanical shutters. Suppression of the light shift is realized using a master-slave laser configuration by reducing the overall optical power delivered to the physics package as well as spoiling the injection of the slave, causing it to lase far off resonance (1-2 nm) as proposed by the authors several years ago [l]. In the absence of any mitigation, this (AC Stark) shift, due to near-resonant laser light reaching the atoms during their microwave interrogation period, is the largest shift in such frequency standards (2x10^-11 for Our fountain). Mechanical shutters provided adequate light attenuation but have been prone to failure.

  20. In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization

    NASA Astrophysics Data System (ADS)

    Yano, Yohko F.; Douguchi, Junya; Kumagai, Atsushi; Iijima, Takao; Tomida, Yukinobu; Miyamoto, Toshiaki; Matsuura, Kazuo

    2006-11-01

    In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the "ultrasonic ethanol separation" reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For the 20mol% ethanol-water mixture, the estimated ethanol mole fraction in the ultrasonic fountain jet by using the position of the main maximum in the x-ray diffraction profile coincided with that in the reservoir. This result suggests that the ethanol separation is not caused by any distorted liquid structure under the ultrasound irradiation and occurs when or after the generation of the liquid droplet mist.

  1. In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization.

    PubMed

    Yano, Yohko F; Douguchi, Junya; Kumagai, Atsushi; Iijima, Takao; Tomida, Yukinobu; Miyamoto, Toshiaki; Matsuura, Kazuo

    2006-11-01

    In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the "ultrasonic ethanol separation" reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For the 20 mol % ethanol-water mixture, the estimated ethanol mole fraction in the ultrasonic fountain jet by using the position of the main maximum in the x-ray diffraction profile coincided with that in the reservoir. This result suggests that the ethanol separation is not caused by any distorted liquid structure under the ultrasound irradiation and occurs when or after the generation of the liquid droplet mist. PMID:17100459

  2. Euler's friction of fluids theory and the estimation of fountain jet heights

    NASA Astrophysics Data System (ADS)

    Bistafa, Sylvio R.

    2015-09-01

    In 1761, Leonhard Euler (1707-1783) published a treatise with the title "Attempt at a Theory of the Friction of Fluids", in which he assumed that, as is the case for solid friction, fluid friction is proportional to pressure. Several experiments were proposed by Euler to derive a friction factor, which were intended to experimentally confirm his equations. Detailed developments of five different problems of discharge were presented in his treatise, taking into account the loss of head in the conduits. In the Appendix, an example is given of the calculation of the jet heights of a particular fountain, fed with conduits of different cross-sectional areas. Application of the current method for the calculation of head losses in pipes reveals that Euler grossly overestimated the fountain jet heights.

  3. Status of the atomic fountain clock at the National Research Council of Canada

    NASA Astrophysics Data System (ADS)

    Beattie, S.; Alcock, J.; Jian, B.; Gertsvolf, M.; Bernard, J.

    2016-06-01

    Despite the rapid advances in optical frequency standards, caesium fountain clocks retain a critical role as the most accurate primary frequency standards available. At the National Research Council Canada, we are working to develop a second generation caesium fountain clock. Work is currently underway to improve several systems of FCs1, such as the laser system and microwave local oscillator, which will be incorporated into its refurbished version, FCs2. In addition, we have added an optical pumping stage which has increased the detected atom number by over a factor of six. In collaboration with the National Physical Laboratory (NPL), we are planning on replacing the physics package of FCs1. We will report on several recent improvements to FCs1, along with our progress in the development of FCs2.

  4. Focusing a fountain of neutral cesium atoms with an electrostatic lens triplet

    SciTech Connect

    Kalnins, Juris G.; Amini, Jason M.; Gould, Harvey

    2005-10-15

    An electrostatic lens with three focusing elements in an alternating-gradient configuration is used to focus a fountain of cesium atoms in their ground (strong-field-seeking) state. The lens electrodes are shaped to produce only sextupole plus dipole equipotentials which avoids adding the unnecessary nonlinear forces present in cylindrical lenses. Defocusing between lenses is greatly reduced by having all of the main electric fields point in the same direction and be of nearly equal magnitude. The addition of the third lens gave us better control of the focusing strength in the two transverse planes and allowed focusing of the beam to half the image size in both planes. The beam envelope was calculated for lens voltages selected to produced specific focusing properties. The calculations, starting from first principles, were compared with measured beam sizes and found to be in good agreement. Application to fountain experiments, atomic clocks, and focusing polar molecules in strong-field-seeking states is discussed.

  5. Laser Cooling of 87Rb to 1.5 μK in a Fountain Clock

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Lü, De-Sheng; Qu, Qiu-Zhi; Zhao, Jian-Bo; Li, Tang; Liu, Liang; Wang, Yu-Zhu

    2011-06-01

    We report an experiment on the adiabatic cooling of 87Rb atoms in an atomic fountain to a temperature as low as 1.5 μK, which is roughly twice the recoil temperature. The atomic fountain has the (1,1,1) optical geometry for cooling and launching of cold atoms. The atoms are first cooled in an optical molasses of 6 beams to 3.4 μK by polarization gradient geometry and then are adiabatically cooled by decreasing the intensity of laser from 1.8Is per beam to zero in 1 ms during the launching of cold atoms. We also study the dependences of atomic temperature on different laser parameters. The method we used is useful in any cold atom physics experiment.

  6. Non-Linear Dependence of the Height of a Chain Fountain on Drop Height

    ERIC Educational Resources Information Center

    Andrew, Y.; Kearns, F.; Mustafa, T.; Salih, R.; Ioratim-Uba, A.; Udall, I.; Usama, M.

    2015-01-01

    If the end of a long chain, which is contained in an elevated beaker, is dropped over the edge of the beaker and falls, it is observed that as the speed of the chain increases the chain rises to form a loop well above the top of the beaker. The name "chain fountain" has been applied to this phenomenon. In this study the dependence of the…

  7. Training plan for the 1164 {lt}90-day non-radioactive hazardous waste storage building

    SciTech Connect

    Demarest, J.L., Westinghouse Hanford

    1996-07-01

    In accordance with Washington Administrative Code (WAC), Chapter 173- 303, `Dangerous Waste Regulations,` a written training plan is required for a {lt}90-day accumulation area. WAC 173-303-200, `Accumulating Dangerous Waste On-site,` requires compliance with WAC- 173-303-330, Personnel Training. This training plan complies with WAC 173-303-330. This training plan, including the names of personnel in Table 1, may be given to a regulatory agency inspector upon request provided that this plan is cleared for public release. Training records associated with personnel identified in this plan are not be given to an outside regulatory agency inspector unless prior approval by the specific individual is obtained. Training records requests by regulatory agency inspectors without the individual`s approval are to be processed via a Freedom of Information Act request through the U.S. Department of Energy, Richland Operations Office.

  8. WATER MASER SURVEY ON AKARI AND IRAS SOURCES: A SEARCH FOR ''LOW-VELOCITY'' WATER FOUNTAINS

    SciTech Connect

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Kwok, Sun; Imai, Hiroshi; Deguchi, Shuji; Henkel, Christian

    2013-05-20

    We present the results of a 22 GHz H{sub 2}O maser survey toward a new sample of asymptotic giant branch (AGB) and post-AGB star candidates. Most of the objects are selected for the first time based on the AKARI data, which have high flux sensitivity in the mid-infrared ranges. We aim at finding H{sub 2}O maser sources in the transient phase between the AGB and post-AGB stages of evolution, where the envelopes start to develop large deviations from spherical symmetry. The observations were carried out with the Effelsberg 100 m radio telescope. Among 204 observed objects, 63 detections (36 new) were obtained. We found four objects that may be ''water fountain'' sources (IRAS 15193+3132, IRAS 18056-1514, OH 16.3-3.0, and IRAS 18455+0448). They possess an H{sub 2}O maser velocity coverage much smaller than those in other known water fountains. However, the coverage is still larger than that of the 1612 MHz OH maser. It implies that there is an outflow with a higher velocity than the envelope expansion velocity (typically {<=}25 km s{sup -1}), meeting the criterion of the water fountain class. We suggest that these candidates are possibly oxygen-rich late AGB or early post-AGB stars in a stage of evolution immediately after the spherically symmetric AGB mass loss has ceased.

  9. Atomic fountain clock with very high frequency stability employing a pulse-tube-cryocooled sapphire oscillator.

    PubMed

    Takamizawa, Akifumi; Yanagimachi, Shinya; Tanabe, Takehiko; Hagimoto, Ken; Hirano, Iku; Watabe, Ken-ichi; Ikegami, Takeshi; Hartnett, John G

    2014-09-01

    The frequency stability of an atomic fountain clock was significantly improved by employing an ultra-stable local oscillator and increasing the number of atoms detected after the Ramsey interrogation, resulting in a measured Allan deviation of 8.3 × 10(-14)τ(-1/2)). A cryogenic sapphire oscillator using an ultra-low-vibration pulse-tube cryocooler and cryostat, without the need for refilling with liquid helium, was applied as a local oscillator and a frequency reference. High atom number was achieved by the high power of the cooling laser beams and optical pumping to the Zeeman sublevel m(F) = 0 employed for a frequency measurement, although vapor-loaded optical molasses with the simple (001) configuration was used for the atomic fountain clock. The resulting stability is not limited by the Dick effect as it is when a BVA quartz oscillator is used as the local oscillator. The stability reached the quantum projection noise limit to within 11%. Using a combination of a cryocooled sapphire oscillator and techniques to enhance the atom number, the frequency stability of any atomic fountain clock, already established as primary frequency standard, may be improved without opening its vacuum chamber. PMID:25167146

  10. NPL Cs fountain frequency standards and the quest for the ultimate accuracy

    NASA Astrophysics Data System (ADS)

    Szymaniec, K.; Lea, S. N.; Gibble, K.; Park, S. E.; Liu, K.; Głowacki, P.

    2016-06-01

    NPL operates a system of two primary caesium fountain clocks consisting of a fully characterised standard NPL-CsF2 together with a new standard NPL-CsF3, which has recently become operational. Both fountains feature a single-stage vapour-loaded magneto-optical trap as the source of cold atoms and an approximate cancellation of the potentially large cold collision frequency shift. As a result, the collision-shift type-B uncertainty is less than 10-16. Subsequently, more subtle systematic effects, including the frequency shifts from distributed cavity phase, microwave lensing and collisions with background gas have also been evaluated at the level of 10-16 or below. Now, as several systematic effects contribute to the fountains’ uncertainty budgets similarly, further significant improvement of their accuracies is expected to be even more difficult. The short-term stability of these standards is also a significant factor limiting the overall precision as many days or even weeks of averaging is required for the type-A statistical uncertainty to approach the declared type-B systematic uncertainty. Going forward, further improvements in the reliability and robustness of operation of fountain standards is one of our priorities.

  11. Similarity and pleasantness assessments of water-fountain sounds recorded in urban public spaces.

    PubMed

    Ekman, Maria Rådsten; Lundén, Peter; Nilsson, Mats E

    2015-11-01

    Water fountains are potential tools for soundscape improvement, but little is known about their perceptual properties. To explore this, sounds were recorded from 32 fountains installed in urban parks. The sounds were recorded with a sound-field microphone and were reproduced using an ambisonic loudspeaker setup. Fifty-seven listeners assessed the sounds with regard to similarity and pleasantness. Multidimensional scaling of similarity data revealed distinct groups of soft variable and loud steady-state sounds. Acoustically, the soft variable sounds were characterized by low overall levels and high temporal variability, whereas the opposite pattern characterized the loud steady-state sounds. The perceived pleasantness of the sounds was negatively related to their overall level and positively related to their temporal variability, whereas spectral centroid was weakly correlated to pleasantness. However, the results of an additional experiment, using the same sounds set equal in overall level, found a negative relationship between pleasantness and spectral centroid, suggesting that spectral factors may influence pleasantness scores in experiments where overall level does not dominate pleasantness assessments. The equal-level experiment also showed that several loud steady-state sounds remained unpleasant, suggesting an inherently unpleasant sound character. From a soundscape design perspective, it may be advisable to avoid fountains generating such sounds. PMID:26627778

  12. The Dynamics of Prolonged Low Fountaining Behaviour at Halemaumau, Kilauea, in December 2013.

    NASA Astrophysics Data System (ADS)

    Houghton, B. F.; Orr, T. R.; Taddeucci, J.; Gonnermann, H. M.; Scarlato, P.; Del Bello, E.; Carey, R.; Patrick, M. R.

    2014-12-01

    Episodes of low-fountaining eruption lasting minutes to tens of minutes alternated with passive degassing at Halema`uma`u during 5 days of observations in December 2013. Some low fountains were triggered by small collapses from the vent walls and originated close to the margin of the lava lake. Others began in the lake interior and migrated to its margins without any obvious link to rock falls. Observations using high-frequency (50-500 Hz) thermal and visible imaging reveal that the fountains consist of sequences of close-spaced, meter-scale pockets of gas that burst through the free surface. Bursts lasted between 0.15 and 1.5 seconds, often partially overlapping in time and space. Bursts entrain both relatively brittle plates from the crust of the lava lake and very ductile thin crust that formed between successive pockets. The latter form spectacular 'lace-work' pyroclasts, of meter-scale diameter, which rise, deform, tear, and fall back into the lava lake. The process can be treated as a form of hydrodynamic fragmentation involving the transformation of masses of accelerating liquid into jets via the generation of liquid films that experience strong stretching during highly non-linear fluid motion.

  13. Fast Screening of Whole Blood Samples and Pharmaceutical Compounds for Enantiorecognition of Free L-T3 , L-T4 , and D-T4.

    PubMed

    Mitrofan, Grigorina; Stefan-van Staden, Raluca-Ioana; Comnea-Stancu, Ionela Raluca; van Staden, Jacobus Frederick; Bazylak, Grzegorz; Kapnissi-Christodoulou, Constantina P; Aboul-Enein, Hassan Y

    2015-12-01

    A fast screening method of whole blood was proposed for enantiorecognition of free L-T3 , L-T4 , and D-T4 . Stochastic microsensors based on four inulins (IN, IQ, TEX, and HD) immobilized on diamond paste (DP) were used for recognition of free L-T3 , L-T4 , and D-T4 . For the enantiorecognition of free L-T4 and D-T4 in whole blood and pharmaceutical samples, the best microsensor was the one based on TEX/DP (wide linear concentration ranges, and low limits of quantification). The best limit of detection for the assay of free L-T3 (400 fmol/L) was recorded using the microsensors based on HD/DP, while for the assay of free L-T4, and D-T4 the best limit of determination (1 pmol/L) was recorded using the TX/DP-based microsensor. For the enantiorecognition of free L-T3 in whole blood and pharmaceutical samples the best microsensor was the one based on HD/DP (the wider linear concentration range, and the lower limit of quantification - of pmol/L magnitude order). For the enantiorecognition of free L-T3 in whole blood and pharmaceutical samples the best microsensor was the one based on HD/DP (the wider linear concentration range, and the lower limit of quantification - of pmol/L magnitude order). Free L-T3 , L-T4 , and D-T4 were recovered with high reliabilities in whole blood samples (recoveries higher than 99.00%, with RSD values lower than 1.00%) and pharmaceutical samples (recoveries higher than 95.00% with RSD values lower than 1.00%). PMID:26447904

  14. Sliding-window raptor codes for efficient scalable wireless video broadcasting with unequal loss protection.

    PubMed

    Cataldi, Pasquale; Grangetto, Marco; Tillo, Tammam; Magli, Enrico; Olmo, Gabriella

    2010-06-01

    Digital fountain codes have emerged as a low-complexity alternative to Reed-Solomon codes for erasure correction. The applications of these codes are relevant especially in the field of wireless video, where low encoding and decoding complexity is crucial. In this paper, we introduce a new class of digital fountain codes based on a sliding-window approach applied to Raptor codes. These codes have several properties useful for video applications, and provide better performance than classical digital fountains. Then, we propose an application of sliding-window Raptor codes to wireless video broadcasting using scalable video coding. The rates of the base and enhancement layers, as well as the number of coded packets generated for each layer, are optimized so as to yield the best possible expected quality at the receiver side, and providing unequal loss protection to the different layers according to their importance. The proposed system has been validated in a UMTS broadcast scenario, showing that it improves the end-to-end quality, and is robust towards fluctuations in the packet loss rate. PMID:20215084

  15. On the estimation of jet-induced fountain lift and additional suckdown in hover for two-jet configurations

    NASA Technical Reports Server (NTRS)

    Kuhn, Richard E.; Bellavia, David C.; Corsiglia, Victor R.; Wardwell, Douglas A.

    1991-01-01

    Currently available methods for estimating the net suckdown induced on jet V/STOL aircraft hovering in ground effect are based on a correlation of available force data and are, therefore, limited to configurations similar to those in the data base. Experience with some of these configurations has shown that both the fountain lift and additional suckdown are overestimated but these effects cancel each other for configurations within the data base. For other configurations, these effects may not cancel and the net suckdown could be grossly overestimated or underestimated. Also, present methods do not include the prediction of the pitching moments associated with the suckdown induced in ground effect. An attempt to develop a more logically based method for estimating the fountain lift and suckdown based on the jet-induced pressures is initiated. The analysis is based primarily on the data from a related family of three two-jet configurations (all using the same jet spacing) and limited data from two other two-jet configurations. The current status of the method, which includes expressions for estimating the maximum pressure induced in the fountain regions, and the sizes of the fountain and suckdown regions is presented. Correlating factors are developed to be used with these areas and pressures to estimate the fountain lift, the suckdown, and the related pitching moment increments.

  16. Eruptive Processes Leading to the Most explosive Lava fountain at Etna Volcano: The 23 November 2013 episode

    NASA Astrophysics Data System (ADS)

    Bonaccorso, Alessandro; Calvari, Sonia

    2015-04-01

    After the end of the last effusive flank eruption on 2008-2009, in January 2011 the eruptive activity resumed at Etna producing a new phase with 44 lava fountain episodes through December 2013. The paroxysmal events took place from a summit vent, the New SE Crater (NSEC), formed on the flank of the SE Crater that in the last few decades was the most active of the summit craters. The 23 November 2013 lava fountain at Etna volcano was the most explosive of these episodes. We infer the total magma volume erupted by thermal images analysis and show that it was characterized by a very high time-averaged-discharge-rate (TADR) of ~360 m^3/s, having erupted ~1.6 × 106 m3 of dense-rock equivalent magma volume in just 45 min, which is more than 3 times the TADR observed during previous episodes. Two borehole dilatometers confirmed the eruption dynamics inferred from the thermal images. When compared to the other lava fountains, this episode can be considered as the explosive end-member. However, the erupted volume was still comparable to the other lava fountain events. We interpret that the 23 November explosive end-member event was caused by more primitive and gas-rich magma entering the system, as demonstrated by the exceptional height reached by the lava fountain.

  17. Suspended sediment and sediment-source areas in the Fountain Creek drainage basin upstream from Widefield, southeastern Colorado

    USGS Publications Warehouse

    Von Guerard, Paul

    1989-01-01

    Suspended-sediment samples were collected from synoptic-sampling sites to determine suspended-sediment concentrations, loads, yields, and sediment-source areas in the Fountain Creek drainage basin upstream from Widefield, Colorado. Suspended-sediment yields ranged from 0.004 to 278 tons/sq mi/day. Twenty-four sites were sampled that represent urban and rural land use. The median suspended-sediment yield from urban drainage basins was 7.7 tons/sq mi/day and the median suspended-sediment yield from rural drainage basins was 0.46 ton/sq mi/day. Sediment-transport equations were derived for total suspended-sediment discharge and suspended-sand discharge at seven periodic-sampling sites. Annual suspended-sediment loads and yields were computed for the 1985 water year. Urbanization in the downstream parts of the Monument Creek drainage basin, the main tributary to Fountain Creek, affected sediment loads. The downstream 14% of the Monument Creek drainage basin contributed about 61% of the annual suspended-sediment load transported at the mouth of Monument Creek. About 73% of the annual suspended-sediment load for Fountain Creek at Colorado Springs was contributed by Monument Creek. Abandoned mill tailings along Fountain Creek contributed little to total suspended sediment load. Contributions of streambank erosion to basin sediment yields were not quantified. However, the measured rate of streambank erosion at a site on Fountain Creek has increased during a 37-year period. (USGS)

  18. Reticulite, Scoria and Lava: Foam Formation in Hawaiian Fire Fountain Eruptions

    NASA Astrophysics Data System (ADS)

    Rust, A. C.; Cashman, K. V.

    2006-12-01

    Hawaiian fire fountain eruptions can generate three types of foams: 1) scoria pyroclasts characterized by spherical bubbles and typical vesicularities of 70-85%, 2) reticulite pyroclasts consisting of a polygonal network of trigonal glass struts and vesicularities of 95-99% and 3) lava flows with bubble contents as high as 70-80%. We use bubble textures to explore the origins of these three distinct foams. With these data and the observation that all three foam types can erupt simultaneously, we discuss the dynamics of Hawaiian eruptions. Our main focus is reticulite, which is a minor but ubiquitous product of relatively high Hawaiian fountains. Compared to scoria, reticulite is more vesicular and has a larger mean bubble size and a much more uniform bubble size distribution. It was previously suggested that reticulite results from further expansion of hot scoria foam. However, to form reticulite from scoria requires not only that gas expand faster than it can percolate through bubble networks in scoria, but also requires processes such as Ostwald ripening that will reduce the range of bubble sizes. Such processes commonly occur in the formation of polygonal soap foams for instance. However, we suggest that a better analogue for reticulite formation is popcorn. In particular we propose that reticulite did not evolve from scoria but from magma that experienced (1) near-instantaneous bubble nucleation followed by (2) rapid and uniform expansion to generate (3) a polyhedral 'dry' foam that then (4) experienced near-instantaneous film rupture and quenching throughout the foam. In contrast, it seems that there are other parts of the system where bubble nucleation is not instantaneous and yields a broader size distribution of bubbles that expand more slowly, maintain spherical shapes, and become permeable through coalescence of small melt films between spherical bubble walls. We suggest that reticulite only forms in relatively high fire fountains, not because of longer

  19. Comparability among four invertebrate sampling methods, Fountain Creek Basin, Colorado, 2010-2012

    USGS Publications Warehouse

    Zuellig, Robert E.; Bruce, James F.; Stogner, Robert W.; Brown, Krystal D.

    2014-01-01

    The U.S. Geological Survey, in cooperation with Colorado Springs City Engineering and Colorado Springs Utilities, designed a study to determine if sampling method and sample timing resulted in comparable samples and assessments of biological condition. To accomplish this task, annual invertebrate samples were collected concurrently using four sampling methods at 15 U.S. Geological Survey streamflow gages in the Fountain Creek basin from 2010 to 2012. Collectively, the four methods are used by local (U.S. Geological Survey cooperative monitoring program) and State monitoring programs (Colorado Department of Public Health and Environment) in the Fountain Creek basin to produce two distinct sample types for each program that target single-and multiple-habitats. This study found distinguishable differences between single-and multi-habitat sample types using both community similarities and multi-metric index values, while methods from each program within sample type were comparable. This indicates that the Colorado Department of Public Health and Environment methods were compatible with the cooperative monitoring program methods within multi-and single-habitat sample types. Comparisons between September and October samples found distinguishable differences based on community similarities for both sample types, whereas only differences were found for single-habitat samples when multi-metric index values were considered. At one site, differences between September and October index values from single-habitat samples resulted in opposing assessments of biological condition. Direct application of the results to inform the revision of the existing Fountain Creek basin U.S. Geological Survey cooperative monitoring program are discussed.

  20. Fountain effect of laser-driven relativistic electrons inside a solid dielectric

    SciTech Connect

    Sarkisov, G. S.; Jobe, D.; Spielman, R.; Leblanc, P.; Ivanov, V. V.; Sentoku, Y.; Yates, K.; Wiewior, P.; Bychenkov, V. Yu.

    2011-09-26

    Ultrafast interferometry with sub-ps resolution has been applied for the direct measurement of an electron density induced by a laser-driven relativistic electron beam inside a solid dielectric. The topology of the interference phase shift shows the signature of the ''fountain effect,'' a narrow electron beam that fans out from the propagation axis and heads back to the target surface. Two-dimensional particle-in-cell (PIC) computer simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields. The very low ionization, {approx}0.1%, observed after the heating pulse suggests a fast recombination at the sub-ps time scale.

  1. Selected hydrologic data for Fountain Creek and Monument Creek basins, east-central Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Ortiz, Roderick F.

    1989-01-01

    Selected hydrologic data were collected during 1986, 1987, and 1988 by the U.S. Geological Survey for the Fountain Creek and Monument Creek basins, east-central Colorado. The data were obtained as part of a study to determine the present and projected effects of wastewater discharges on the two creeks. The data, which are available for 129 surface-water sites, include: (1) About 1,100 water quality analyses; (2) about 420 measurements of discharge, (3) characteristics of about 50 dye clouds associated with measurements of traveltime and reaeration , and (4) about 360 measurements of channel geometry. (USGS)

  2. Design for a fountain of YbF molecules to measure the electron's electric dipole moment

    NASA Astrophysics Data System (ADS)

    Tarbutt, M. R.; Sauer, B. E.; Hudson, J. J.; Hinds, E. A.

    2013-05-01

    We propose an experiment to measure the electric dipole moment (EDM) of the electron using ultracold YbF molecules. The molecules are produced as a thermal beam by a cryogenic buffer gas source, and brought to rest in an optical molasses that cools them to the Doppler limit or below. The molecular cloud is then thrown upward to form a fountain in which the EDM of the electron is measured. A non-zero result would be unambiguous proof of new elementary particle interactions, beyond the standard model.

  3. Simultaneous differential measurement of a magnetic-field gradient by atom interferometry using double fountains

    SciTech Connect

    Hu Zhongkun; Duan Xiaochun; Zhou Minkang; Sun Buliang; Zhao Jinbo; Huang Maomao; Luo Jun

    2011-07-15

    Precisely measuring the magnetic-field gradient within a vacuum chamber is important for many precision experiments and can be realized by atom interferometry using magnetically sensitive sublevels at different times to make a differential measurement, which had been demonstrated in our previous work. In this paper, we demonstrate a differential method to measure the magnetic-field gradient by means of two simultaneously operated atom interferometers using double atomic fountains. By virtue of this simultaneous differential measurement to reject common-mode noise, the resolution can be improved by one order of magnitude for about a 1000-s integration time.

  4. The Effects of Crossflow on the Pressures and Lift Induced by the Fountain Generated Between Two Impinging Jets

    NASA Technical Reports Server (NTRS)

    Kuhn, Richard E.

    1998-01-01

    When a jet STOVL aircraft is hovering, or in a crossflow, while close to the ground wall jets flowing radially outward from the impingement points of the jets are generated. An upflow, or fountain, is generated where the wall jets from adjacent jets meet on the ground surface. The induced lift and suckdown generated by the impingement of the fountain on the lower surface of the configuration has been the subject of previous studies. This study analyzes the limited available pressure and force data on the effect of crossflow on the fountain induced lift and suckdown. The analysis includes the effects of jet spacing, height and operating conditions. However, it is limited to twin jet configurations of circular, vertical jets operating at subcritical nozzle pressure ratios over a fixed ground surface.

  5. Eruption dynamics of Hawaiian-style fountains: the case study of episode 1 of the Kīlauea Iki 1959 eruption

    NASA Astrophysics Data System (ADS)

    Stovall, Wendy K.; Houghton, B. F.; Gonnermann, H.; Fagents, S. A.; Swanson, D. A.

    2011-07-01

    Hawaiian eruptions are characterized by fountains of gas and ejecta, sustained for hours to days that reach tens to hundreds of meters in height. Quantitative analysis of the pyroclastic products from the 1959 eruption of Kīlauea Iki, Kīlauea volcano, Hawai`i, provides insights into the processes occurring during typical Hawaiian fountaining activity. This short-lived but powerful eruption contained 17 fountaining episodes and produced a cone and tephra blanket as well as a lava lake that interacted with the vent and fountain during all but the first episode of the eruption, the focus of this paper. Microtextural analysis of Hawaiian fountaining products from this opening episode is used to infer vesiculation processes within the fountain and shallow conduit. Vesicle number densities for all clasts are high (106-107 cm-3). Post-fragmentation expansion of bubbles within the thermally-insulated fountain overprints the pre-fragmentation bubble populations, leading to a reduction in vesicle number density and increase in mean vesicle size. However, early quenched rims of some clasts, with vesicle number densities approaching 107 cm-3, are probably a valid approximation to magma conditions near fragmentation. The extent of clast evolution from low vesicle-to-melt ratio and corresponding high vesicle number density to higher vesicle-to-melt ratio and lower vesicle-number density corresponds to the length of residence time within the fountain.

  6. Density, Grain-size, and Vesicle Analysis of Hawaiian Fountains During the 1969 Mauna Ulu Eruption at Kilauea

    NASA Astrophysics Data System (ADS)

    Parcheta, C. E.; Houghton, B. F.; Swanson, D.

    2011-12-01

    Fountains from the Mauna Ulu eruption in 1969 produced a tephra cone and blanket similar in size to that of Kilauea Iki a decade earlier. The 12 episodes from the eruption displayed a range of fountain behaviors, from low fissure fountains on May 24 (episode 1) to high paired and single circular-sourced fountains in episodes 2 through 12. The highest fountain from this eruption was during the 9-hr long episode 9 (Sep 6-7), and reached 540 m, the second highest fountain recorded at Kilauea. Differences in the vigor and eruption style of these Hawaiian fountains are broadly related to the gas content driving magma ascent through the plumbing system in the east rift zone and the rate and timing of exsolution of this gas. While the tephra cone is now buried under 70 m of a lava shield, and lava flows cover the eastern half of the tephra blanket, the western half of the tephra blanket is still exposed. The nearest possible sample location to the vent is 1.7 km SW of the summit of Mauna Ulu. Transects across (east to west) and down (north to south) the wind direction were made to obtain a partial data set for the Mauna Ulu tephra remaining on the surface. Density, grain-size, and vesicle analysis was performed for a complete stratigraphic column recreated with the crosswind transect data; maximum class dimensions were measured in downwind pits. Median density shifts and the occurrence of bimodal density samples suggest gradual outgassing of the whole system with at least one injection of gas-rich material coming into the system during the seven months of eruption in 1969. Median grain-size is consistent at -2.5 to -2.0 phi. Polished thin sections show microlites in some pyroclasts, which may indicate magma mixing (also suggested in Swanson et al., 1979) either with previously erupted and recycled material from the Mauna Ulu eruption or a second magma source stored in the easternmost portion of the Koa'e fault system. We present here new data on vesicle number density and

  7. A User's Manual for ROTTILT Solver: Tiltrotor Fountain Flow Field Prediction

    NASA Technical Reports Server (NTRS)

    Tadghighi, Hormoz; Rajagopalan, R. Ganesh

    1999-01-01

    A CFD solver has been developed to provide the time averaged details of the fountain flow typical for tiltrotor aircraft in hover. This Navier-Stokes solver, designated as ROTTILT, assumes the 3-D fountain flowfield to be steady and incompressible. The theoretical background is described in this manual. In order to enable the rotor trim solution in the presence of tiltrotor aircraft components such as wing, nacelle, and fuselage, the solver is coupled with a set of trim routines which are highly efficient in CPU and suitable for CFD analysis. The Cartesian grid technique utilized provides the user with a unique capability for insertion or elimination of any components of the bodies considered for a given tiltrotor aircraft configuration. The flowfield associated with either a semi or full-span configuration can be computed through user options in the ROTTILT input file. Full details associated with the numerical solution implemented in ROTTILT and assumptions are presented. A description of input surface mesh topology is provided in the appendices along with a listing of all preprocessor programs. Input variable definitions and default values are provided for the V22 aircraft. Limited predicted results using the coupled ROTTILT/WOPWOP program for the V22 in hover are made and compared with measurement. To visualize the V22 aircraft and predictions, a preprocessor graphics program GNU-PLOT3D was used. This program is described and example graphic results presented.

  8. Shrinking galaxy disks with fountain-driven accretion from the halo

    SciTech Connect

    Elmegreen, Bruce G.; Struck, Curtis; Hunter, Deidre A. E-mail: curt@iastate.edu

    2014-12-01

    Star formation in most galaxies requires cosmic gas accretion because the gas consumption time is short compared to the Hubble time. This accretion presumably comes from a combination of infalling satellite debris, cold flows, and condensation of hot halo gas at the cool disk interface, perhaps aided by a galactic fountain. In general, the accretion will have a different specific angular momentum than the part of the disk that receives it, even if the gas comes from the nearby halo. The gas disk then expands or shrinks over time. Here we show that condensation of halo gas at a rate proportional to the star formation rate in the fountain model will preserve an initial shape, such as an exponential, with a shrinking scale length, leaving behind a stellar disk with a slightly steeper profile of younger stars near the center. This process is slow for most galaxies, producing imperceptible radial speeds, and it may be dominated by other torques, but it could be important for blue compact dwarfs, which tend to have large, irregular gas reservoirs and steep blue profiles in their inner stellar disks.

  9. ALMA Reveals a Galaxy-Scale Fountain of Cold Molecular Gas Pumped by a Black Hole

    NASA Astrophysics Data System (ADS)

    Tremblay, Grant

    2016-01-01

    A new ALMA observation of the cool core brightest cluster galaxy in Abell 2597 reveals that a supermassive black hole can act much like a mechanical pump in a water fountain, driving a convective flow of molecular gas that drains into the black hole accretion reservoir, only to be pushed outward again in a jet-driven outflow that then rains back toward the galaxy center from which it came. The ALMA data reveal "shadows" cast by giant molecular clouds falling on ballistic trajectories towards the black hole in the innermost 500 parsecs of the galaxy, manifesting as deep redshifted continuum absorption features. The black hole accretion reservoir, fueled by these infalling cold clouds, powers an AGN that drives a jet-driven molecular outflow in the form of a 10 kpc-scale, billion solar mass expanding molecular bubble or plume. The molecular shell is permeated with young stars, perhaps triggered in situ by the jet. Buoyant X-ray cavities excavated by the propagating radio source may further uplift the molecular filaments, which are observed to fall inward toward the center of the galaxy from which they came, presumably keeping the fountain long-lived. The results show that cold molecular gas can couple to black hole growth via both feedback and feeding, in alignment with "cold chaotic accretion" models for the regulation of star formation in galaxies.

  10. The First Water Fountain in a Planetary Nebula with Synchrotron Emission

    NASA Astrophysics Data System (ADS)

    Suárez, O.; Gómez, J. F.; Bendjoya, Ph.; Miranda, L. F.; Guerrero, M. A.; Uscanga, L.; Green, J. A.; Rizzo, J. R.; Ramos-Larios, G.

    2015-12-01

    Planetary nebulae (PNe) show a great variety of morphologies at optical wavelengths that might be due to the effects of jets (Sahai & Trauger [8]) and where magnetic fields might also play an important role. The special class of "water fountain" stars, showing high-velocity, collimated jets traced by water maser emission are key objects to understand the transition to the PN phase and the effect of the jets. IRAS 15103-5754 has been revealed as the youngest PN known, caught just at its birth. It is the first PN that shows water fountain characteristics (Gómez et al. [5]), and it shows, for the first time, direct evidence of the presence of synchrotron emission in a PN, tracing energetic, magnetized shocks (Suárez et al. [9]). Moreover, we observed a sudden change in the spectral distribution of its radio continuum emission, which marks the fast, recent passage of the ionization front over the radio-emitting region (Suárez et al. [9]).

  11. The impact of galactic fountains on the global evolution of galaxy disks

    NASA Astrophysics Data System (ADS)

    Fraternali, F.

    2016-06-01

    The evolution of the Milky Way, and its thin disc in particular, is a history of continuous accretion of fresh gas from the surrounding environment. Evidence for this accretion taking place include high-velocity clouds (HVCs) that appear to be raining down from the halo. I present a model that explains the formation of the prototypical HVC Complex C as gas cooling of the Galactic corona triggered by the explosion of a superbubble in the Outer arm occurred 150 Myr ago. This result is obtained with a new galactic fountain model combined with high-resolution hydrodynamical simulations. The material ejected by the superbubble has triggered the condensation of a large portion of the circumgalactic medium and caused its subsequent accretion on to the disc. This is a local manifestation of fountain-driven cooling of the lower Galactic corona that can contribute significantly in brining fresh low-metallicity gas to the disc of our Galaxy. The same model also reproduces the global-scale kinematics of the extraplanar gas and predicts a gas accretion that evolves inside-out.

  12. Evidences of increasing primary production in the ocean by Stommel's perpetual salt fountain

    NASA Astrophysics Data System (ADS)

    Maruyama, Shigenao; Yabuki, Takashi; Sato, Tetsuya; Tsubaki, Koutaro; Komiya, Atsuki; Watanabe, Mikihito; Kawamura, Hiroshi; Tsukamoto, Katsumi

    2011-05-01

    The American physical oceanographer Henry Stommel and co-workers proposed "the perpetual salt fountain" and suggested the possibility of upwelling deep seawater without an energy source. In the open ocean, deep seawater containing rich nutrients becomes a source of primary production. Previously, we have tested Stommel's hypothesis by numerical simulations and in ocean experiments, and confirmed the upwelling of a perpetual salt fountain. In the present study, we conducted an open-ocean experiment in the Philippines Sea, and succeeded to demonstrate an increase in chlorophyll concentration. The chlorophyll concentration at the pipe outlet was much greater than that in the surrounding seawater. Satellite ocean-color image around the pipe was analyzed, and the signal of artificial upwelling is investigated. Composite analysis of satellite chlorophyll image indicates an increased surface chlorophyll distribution in the vicinity of pipe position, in which the increasing signal is much larger than the expected production based on nutrient supply. Although the problem must be further discussed, this increased signal is shown to be statistically significant. This mechanism may contribute to effective utilization of fishery resources in subtropical oligotrophic region.

  13. Proposal of a truncated atomic beam fountain for reduction of collisional frequency shift

    SciTech Connect

    Takamizawa, A.; Yanagimachi, S.; Ikegami, T.; Shirakawa, Y.

    2010-07-15

    We propose an atomic fountain clock with a truncated cold atomic beam to achieve both a low collisional frequency shift and high frequency stability. In this clock, the launching velocity of a cold atomic beam can be swept to reduce the atomic density in the interrogation region for the Ramsey resonance and to increase the atomic density in the detection region. Before the top of the beam arrives at the interrogation region, the cold atomic beam is truncated by turning off the cooling laser beams to remove the unnecessary light shift. The atomic density in the interrogation region is theoretically evaluated to be 0.04 times that in an ordinary atomic fountain with optical molasses for the same number of detected atoms. The frequency stability limit due to quantum projection noise is calculated to reach 6.4x10{sup -14} in 1 s from the number of detected atoms while the fractional collisional shift is estimated to be {approx}{sup -}2x10{sup -16}.

  14. Remediation scenarios for attenuating peak flows and reducing sediment transport in Fountain Creek, Colorado, 2013

    USGS Publications Warehouse

    Kohn, Michael S.; Fulton, John W.; Williams, Cory A.; Stogner, Robert W.

    2014-01-01

    The U.S. Geological Survey (USGS) in cooperation with the Fountain Creek Watershed, Flood Control and Greenway District assessed remediation scenarios to attenuate peak flows and reduce sediment loads in the Fountain Creek watershed. To evaluate these strategies, the U.S. Army Corps of Engineers Hydrologic Engineering Center (HEC) hydrologic and hydraulic models were employed. The U.S. Army Corps of Engineers modeling system HEC-HMS (Hydrologic Modeling System) version 3.5 was used to simulate runoff in the Fountain Creek watershed, Colorado, associated with storms of varying magnitude and duration. Rain-gage precipitation data and radar-based precipitation data from the April 28–30, 1999, and September 14–15, 2011, storm events were used in the calibration process for the HEC-HMS model. The curve number and lag time for each subwatershed and Manning's roughness coefficients for each channel reach were adjusted within an acceptable range so that the simulated and measured streamflow hydrographs for each of the 12 USGS streamgages approximated each other. The U.S. Army Corps of Engineers modeling system HEC-RAS (River Analysis System) versions 4.1 and 4.2 were used to simulate streamflow and sediment transport, respectively, for the Fountain Creek watershed generated by a particular storm event. Data from 15 USGS streamgages were used for model calibration and 7 of those USGS streamgages were used for model validation. The calibration process consisted of comparing the simulated water-surface elevations and the cross-section-averaged velocities from the model with those surveyed in the field at the cross section at the corresponding 15 and 7 streamgages, respectively. The final Manning’s roughness coefficients were adjusted between –30 and 30 percent at the 15 calibration streamgages from the original left, right, and channel-averaged Manning's roughness coefficients upon completion of calibration. The U.S. Army Corps of Engineers modeling system HEC

  15. Identification and dating of the fountain pen ink entries on documents by ion-pairing high-performance liquid chromatography.

    PubMed

    Wang, Xiang-Feng; Yu, Jing; Xie, Meng-Xia; Yao, Ya-Tong; Han, Jie

    2008-08-25

    A novel approach for the identification and dating of the fountain pen ink entries on paper has been established by ion-pairing high-performance liquid chromatography (IP-HPLC). Twelve black and six red fountain inks have been collected, and their ink entries have been prepared by drawing lines on paper. The chromatographic conditions for separation of their dye components after extraction with solvents were optimized. Under the optimized conditions, the 18 fountain pen inks were differentiated individually by comparing the number of detectable main or minor dye components, and the relative peak intensities of each component. The ink entries were artificially and naturally aged, and the analysis results showed that the ink dye components were significantly decomposed when exposed to UV or fluorescent light compare to those of inks stored under natural condition. The changes of the relative peak height for the dye components were linearly related to the aging time, especially under natural aging conditions. The degradation characteristics of the dye components under different aging conditions provide scientific evidences for dating of the suspicious fountain pen ink entries on document. PMID:18703295

  16. Merit Pay in Arkansas: An Evaluation of the Cobra Pride Incentive Program in the Fountain Lake School District

    ERIC Educational Resources Information Center

    Jensen, Nathan C.

    2012-01-01

    Starting in the 2010-11, administrators at the Fountain Lake School District implemented the Cobra Pride Incentive Program (CPIP), a merit pay program designed to financially reward all school employees with year-end bonuses primarily for significant improvements in student achievement. At the conclusion of the 2010-11 school year, over $800,000…

  17. SuperLab LT: Evaluation and Uses in Teaching Experimental Psychology

    ERIC Educational Resources Information Center

    Ragozzine, Frank

    2002-01-01

    I describe and evaluate SuperLab LT (Chase & Abboud, 1990), a software package that enables students to replicate classic experiments in cognitive psychology. I also discuss the package with respect to its uses in teaching an undergraduate course in Experimental Psychology. Although the package has minor flaws, SuperLab LT provides numerous…

  18. Loss Reduction on Adoption of High Voltage LT Less Distribution

    NASA Astrophysics Data System (ADS)

    Tiwari, Deepika; Adhikari, Nikhileshwar Prasad; Gupta, Amit; Bajpai, Santosh Kumar

    2015-03-01

    In India there is a need to improve the quality of the electricity distribution process which has increased varying from year to year. In distribution networks, the limiting factor to load carrying capacity is generally the voltage reduction. High voltage distribution system (HVDS) is one of the steps to reduce line losses in electrical distribution network. It helps to reduce the length of low tension (LT) lines and makes the power available close to the users. The high voltage power distribution system reduces the probability of power theft by hooking HVDS suggests an increase in installation of small capacity single-phase transformers in the network which again save considerable energy. This paper is compared to existing conventional low tension distribution network with HVDS. The paper gives a clear picture of reduction in distribution losses with adoption of HVDS system. Losses Reduction of 11 kV Feeder in Nuniya (India) with adoption of HVDS have been worked out/ quantified and benefits thereby in generating capacity have discussed.

  19. Loss Reduction on Adoption of High Voltage LT Less Distribution

    NASA Astrophysics Data System (ADS)

    Tiwari, Deepika; Adhikari, Nikhileshwar Prasad; Gupta, Amit; Bajpai, Santosh Kumar

    2016-06-01

    In India there is a need to improve the quality of the electricity distribution process which has increased varying from year to year. In distribution networks, the limiting factor to load carrying capacity is generally the voltage reduction. High voltage distribution system (HVDS) is one of the steps to reduce line losses in electrical distribution network. It helps to reduce the length of low tension (LT) lines and makes the power available close to the users. The high voltage power distribution system reduces the probability of power theft by hooking HVDS suggests an increase in installation of small capacity single-phase transformers in the network which again save considerable energy. This paper is compared to existing conventional low tension distribution network with HVDS. The paper gives a clear picture of reduction in distribution losses with adoption of HVDS system. Losses Reduction of 11 kV Feeder in Nuniya (India) with adoption of HVDS have been worked out/ quantified and benefits thereby in generating capacity have discussed.

  20. Modeling ash dispersal of the 23 February 2013 Etna lava fountain

    NASA Astrophysics Data System (ADS)

    Poret, Matthieu; Costa, Antonio; Andronico, Daniele; Scollo, Simona; Gouhier, Mathieu

    2016-04-01

    Most plumes generated by explosive eruptions from Mt. Etna, Italy, are affected by winds towards East driving volcanic ash over the sea. It implies that erupted tephra can be collected only at proximal area around the volcano, i.e. within 20-25 km. It follows that the quantification of fine ash component and the Total Grain Size Distribution (TGSD) are very difficult and highly uncertain. Among the five lava fountain episodes occurred on the New South-East Crater of Mt. Etna, from the 17 to 23 February 2013, the 23 February paroxysmal phase lasted 1 hour and produced magma jets higher than 500 m and an eruptive plume that reached ~9 km above sea level. Winds oriented toward North-East advected the plume and produced an extended tephra fallout deposit from the slope of Etna up to Puglia region (~ 400 km from the volcano), allowing lapilli and ash to be sampled at different locations. Here, we first estimate the TGSD and the fine ash content associated to 12 samples collected after the paroxysmal episode over the entire tephra blanket. The TGSD is compared with the one related to the 12-13 January 2011 lava fountain showing a similar distribution with a mode around phi = -3. Satellite data describing the evolution of PM10 from the vent up to Calabria region were used to quantify the tail of the distribution and the fraction of the very fine ash. In order to reproduce both the field and spaceborne (MSG-SEVIRI) observations we simulated the tephra dispersal using the computational model Fall3D after modifying the TGSD by adding the fine ash component empirically. A set of simulations allowed us to assess key volcanological parameters such as the column height, the mass distribution within the plume and the effective TGSD. Best fit results indicate a Mass Eruption Rate around 1.0d+6 kg/s, a Total Erupted Mass of about 3.8d+9 kg and a PM10 fraction of ~0.73% respect to the total mass. Results lead the 23 February 2013 lava fountain episode as one of the most intense in

  1. Regulation of L-arabinose transport in Salmonella typhimurium LT2.

    PubMed

    Lee, J H; Russo, R J; Heffernan, L; Wilcox, G

    1982-01-01

    The inducible L-arabinose transport system was characterized in Salmonella typhimurium LT2. Only one L-arabinose transport system with a Km of 2 X 10(-4) M was identified. The results suggested that araE may be the only gene which codes for L-arabinose transport activity under the conditions tested. An araE-lac fusion strain was used to study the induction of the araE gene. No araE expression was detected when the L-arabinose concentration was lower than 1 mM. The expression of araE reached a maximum in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of D-glucose. Expression of the araBAD and araE genes was coordinately regulated. The concentration of L-arabinose that allowed maximum araBAD gene expression was 50-fold lower in an araE+ strain compared to an araE strain. PMID:6283309

  2. Cholera toxin, LT-I, LT-IIa, and LT-IIb: the critical role of ganglioside-binding in immunomodulation by Type I and Type II heat-labile enterotoxins

    PubMed Central

    Connell, Terry D.

    2010-01-01

    The heat-labile enterotoxins (HLT) expressed by Vibrio cholerae (cholera toxin) and Escherichia coli (LT-I, LT-IIa, and LT-IIb) are potent systemic and mucosal adjuvants. Co-administration of the enterotoxins with a foreign antigen (Ag) produces an augmented immune response to that antigen. Although each enterotoxin has potent adjuvant properties, the means by which the enterotoxins induce various immune responses are distinctive for each adjuvant. Various mutants have been engineered to dissect the functions of the enterotoxins required for their adjuvanticity. The capacity to strongly bind to one or more specific ganglioside receptors appears to drive the distinctive immunomodulatory properties associated with each enterotoxin. Mutant enterotoxins with ablated or altered ganglioside binding affinities have been employed to investigate the role of gangliosides in enterotoxin-dependent immunomodulation. PMID:17931161

  3. Pharmacological characterization of conotoxin lt14a as a potent non-addictive analgesic.

    PubMed

    Ren, Zhenghua; Wang, Lei; Qin, Mengying; You, Yuwen; Pan, Wuguang; Zhou, Liang; Sun, Dandan; Xu, Anlong

    2015-03-01

    Conotoxin lt14a is a small peptide consisting of 13 amino acids. It was originally identified from the cDNA of Conus litteratus in the South China Sea. Previous reports showed lt14a exhibited antinociceptive activity using a hot plate-induced pain mouse model and acted as an antagonist of neuronal nicotinic acetylcholine receptors. We confirmed that conotoxin lt14a administration resulted in antinociception activity using a mouse inflammatory pain model and a rat model of mechanically-induced pain. The mRNA expression of c-fos and NOS in the spinal cord of rats was suppressed by lt14a. Labeling of lt14a with an Alexa Fluor 488 ester showed that lt14a was bound to the surface of PC12 cells and that this binding was inhibited by pre-application of the nicotinic acetylcholine receptor (nAChR) antagonist tubocurarine chloride (TUB) and the nAChR blocker hexamethonium bromide (HB). These data confirm previous reports that showed lt14a binds to the surface of PC12 cells via nAChRs with patch clamp whole-cell recordings. Additional results showed that lt14a suppressed extracellular signal-regulated kinase (ERK1/2) phosphorylation in PC12 cells activated by Ach. Our results showed that lt14a did not induce drug dependence but rather suppressed morphine withdrawal symptoms. Our work suggests that lt14a is a novel antinociceptive agent that targets the nAChR receptor without inducing drug dependence. PMID:25617597

  4. Suckdown, fountain lift, and pressures induced on several tandem jet V/STOL configurations

    NASA Technical Reports Server (NTRS)

    Bellavia, David C.; Wardwell, Douglas A.; Corsiglia, Victor R.; Kuhn, Richard E.

    1991-01-01

    As part of a program to improve the methods for predicting the suckdown and hot gas ingestion for jet V/STOL aircraft in ground effect, a data base is being created that provides a systematic variation of parameters so that a new empirical prediction procedure can be developed. The first series of tests in this program was completed. Suckdown, fountain lift, and pressures induced on several two-jet V/STOL configurations are described. It is one of three reports that present the data obtained from tests conducted at Lockheed Aeronautical Systems-Rye Canyon Facility and in the High Bay area of the 40 by 80 foot wind tunnel complex at NASA Ames Research Center.

  5. Darcy's Public Fountains of the City of Dijon, Past and Present

    NASA Astrophysics Data System (ADS)

    Bobeck, P.; Ritzi, R. W.; Bair, E. S.

    2006-12-01

    Les Fountaines Publiques de la Ville de Dijon (Darcy, 1856) is well known for introducing the equation of ground-water motion. The monograph is a summary of Darcy's career-long study of hydraulics including water flow in canals, aqueducts, pipes, sand filters, and ground-water wells. He presented his knowledge in these areas in reviewing his construction of the public water supply system for Dijon, a system completed in 1840. The authors have recently traveled the length of Darcy's aqueduct system from its source at Rosoir spring, to the Porte Guillaume reservoir (at Jardin Darcy as it enters Dijon), through the city, to the terminal reservoir. We present the state of Darcy's original aqueduct (no longer in use) and public water supply system, and compare his design to the modern public water supply system serving Dijon.

  6. Effect of turbulent fluctuations on the behaviour of fountains in stratified environments

    NASA Astrophysics Data System (ADS)

    Freire, D.; Cabeza, C.; Pauletti, S.; Sarasúa, G.; Bove, I.; Usera, G.; Martí, A. C.

    2010-09-01

    The interaction between a turbulent fountain and its stratified environment was studied. A heavy fluid, cold water, was injected vertically upwards into a linearly stratified medium. The round heavy-fluid jet reaches a maximum height before it begins to fall due to the effect of gravity. Because of the effects of friction and mixing, the vertical momentum and density of the jet fluid decrease as it submerges to an intermediate height of zero buoyancy. At this point, the jet fluid spreads as a horizontal front, intruding into the stratified environment. The degree of fluctuation in the proximity of the injection point was studied under both unrestricted- and restricted-flow configurations at the injection, using two differently sized stainless-steel woven-wire screens at the injection port as flow-restricting means. Using visualization and velocimetry techniques, both maximum and spreading heights were found to decrease with increasing turbulence at the point of injection.

  7. Obscuring Fraction of Active Galactic Nuclei: Implications from Radiation-driven Fountain Models

    NASA Astrophysics Data System (ADS)

    Wada, Keiichi

    2015-10-01

    Active galactic nuclei (AGNs) are believed to be obscured by an optical thick “torus” that covers a large fraction of solid angles for the nuclei. However, the physical origin of the tori and the differences in the tori among AGNs are not clear. In a previous paper based on three-dimensional radiation-hydorodynamic calculations, we proposed a physics-based mechanism for the obscuration, called “radiation-driven fountains,” in which the circulation of the gas driven by central radiation naturally forms a thick disk that partially obscures the nuclear emission. Here, we expand this mechanism and conduct a series of simulations to explore how obscuration depends on the properties of AGNs. We found that the obscuring fraction fobs for a given column density toward the AGNs changes depending on both the AGN luminosity and the black hole mass. In particular, fobs for NH ≥ 1022 cm-2 increases from ˜0.2 to ˜0.6 as a function of the X-ray luminosity LX in the LX = 1042-44 erg s-1 range, but fobs becomes small (˜0.4) above a luminosity (˜1045 erg s-1). The behaviors of fobs can be understood by a simple analytic model and provide insight into the redshift evolution of the obscuration. The simulations also show that for a given LAGN, fobs is always smaller (˜0.2-0.3) for a larger column density (NH ≥ 1023 cm-2). We also found cases that more than 70% of the solid angles can be covered by the fountain flows.

  8. Bioaccumulation of Selenium by the Bryophyte Hygrohypnum ochraceum in the Fountain Creek Watershed, Colorado

    NASA Astrophysics Data System (ADS)

    Herrmann, S. J.; Turner, J. A.; Carsella, J. S.; Lehmpuhl, D. W.; Nimmo, D. R.

    2012-12-01

    Aquatic bryophytes, Hygrohypnum ochraceum, were deployed "in situ" at 14 sites in the Fountain Creek Watershed, spring and fall, 2007 to study selenium (Se) accumulation. Dissolved, total, and pore (sediment derived) water samples were collected and water quality parameters determined while plants were exposed to the water for 10 days. There was a trend showing plant tissue-Se uptake with distance downstream and we found a strong correlation between Se in the water with total hardness in both seasons. There was a modest association between Se-uptake in plants with hardness in the spring of 2007 but not the fall. Plants bioconcentrated Se from the water by a factor of 5.8 × 103 at Green Mountain Falls and 1.5 × 104 at Manitou Springs in the fall of 2007. Both are examples of the bioconcentration abilities of the plants, primarily in the upper reaches of the watershed where bioconcentration factors were highest. However, the mean minima and maxima of Se in the plants in each of the three watershed segments appeared similar during both seasons. We found direct relationships between the pore and dissolved Se in water in the spring ( R 2 = 0.84) and fall ( R 2 = 0.95) and dissolved Se and total hardness in the spring and fall ( R 2 = 0.92). The data indicate that H. ochraceum was a suitable indicator of Se bioavailability and Se uptake in other trophic levels in the Fountain Creek Watershed based on a subsequent study of Se accumulation in fish tissues at all 14 sites.

  9. Mercury and selenium in fish of Fountain Creek, Colorado (USA): possible sources and implications.

    PubMed

    Nimmo, D R; Herrmann, S J; Carsella, J S; McGarvy, C M; Foutz, H P; Herrmann-Hoesing, L M; Gregorich, J M; Turner, J A; Vanden Heuvel, B D

    2016-01-01

    Fountain Creek in Colorado USA is a major tributary that confluences with the Arkansas River at Pueblo, Colorado, the result being the tributary's influence on Arkansas River water quality affecting down-stream users. In a previous study, we found that bryophytes (aquatic plants) accumulated selenium in Fountain Creek watershed and this finding prompted us to investigate the extent of the metalloid in the whole-body tissues of fish. One hundred 11 fish (six species) were collected and analyzed for Se by inductively-coupled plasma emission mass spectrometry. Analysis of all analytical data also showed mercury in all of the fish whole bodies and selected tissues. There was a general increase in selenium but a decrease in mercury in fish with downstream travel-distance. The highest whole-body selenium was in Pueblo, Colorado (3393 µg/kg, dry weight; 906 µg/kg, wet weight); the highest mercury in fish was in the Monument Creek tributary north of Colorado Springs, Colorado (71 µg/kg, dry weight; 19 µg/kg, wet weight). In four tissues of 11 female fish captured, selenium was highest in the livers at eight sites but highest in the ovaries at three sites. Mercury was highest in the epaxial muscle at all sites. Selenium availability could be due to the watershed lithology and land uses; however, mercury could be carried by atmospheric deposition from coal-fired power plants and historic mining activities. Selenium in fish tissues and water samples were compared to U.S. national water quality criteria. PMID:27104125

  10. Magma mixing and high fountaining during the 1959 Kīlauea Iki eruption, Hawai‘i

    USGS Publications Warehouse

    Sides, I.; Edmonds, M.; Maclennan, J.; Houghton, B. F.; Swanson, Don; Steele-MacInnis, M.J.

    2014-01-01

    The 1959 Kīlauea Iki eruption provides a unique opportunity to investigate the process of shallow magma mixing, its impact on the magmatic volatile budget and its role in triggering and driving episodes of Hawaiian fountaining. Melt inclusions hosted by olivine record a continuous decrease in H2O concentration through the 17 episodes of the eruption, while CO2 concentrations correlate with the degree of post-entrapment crystallization of olivine on the inclusion walls. Geochemical data, when combined with the magma budget and with contemporaneous eruption observations, show complex mixing between episodes involving hot, geochemically heterogeneous melts from depth, likely carrying exsolved vapor, and melts which had erupted at the surface, degassed and drained-back into the vent. The drained-back melts acted as a coolant, inducing rapid cooling of the more primitive melts and their olivines at shallow depths and inducing crystallization and vesiculation and triggering renewed fountaining. A consequence of the mixing is that the melts became vapor-undersaturated, so equilibration pressures cannot be inferred from them using saturation models. After the melt inclusions were trapped, continued growth of vapor bubbles, caused by enhanced post-entrapment crystallization, sequestered a large fraction of CO2 from the melt within the inclusions. This study, while cautioning against accepting melt inclusion CO2 concentrations “as measured” in mixed magmas, also illustrates that careful analysis and interpretation of post-entrapment modifications can turn this apparent challenge into a way to yield novel useful insights into the geochemical controls on eruption intensity.

  11. From the ashes: JVLA observations of water fountain nebula candidates show the rebirth of IRAS 18455+0448

    NASA Astrophysics Data System (ADS)

    Vlemmings, W. H. T.; Amiri, N.; van Langevelde, H. J.; Tafoya, D.

    2014-09-01

    Context. The class of water fountain nebulae is thought to represent the stage of the earliest onset of collimated bipolar outflows during the post-asymptotic giant branch phase. They thus play a crucial role in the study of the formation of bipolar planetary nebulae (PNe). To date, 14 water fountain nebulae have been identified. The identification of more sources in this unique stage of stellar evolution will enable us to study the origin of bipolar PNe morphologies in more detail. Aims: Water fountain candidates can be identified based on the often double peaked 22 GHz H2O maser spectrum with a large separation between the maser peaks (often >100 km s-1). However, even a fast bipolar outflow will only have a moderate velocity extent in its maser spectrum when located close to the plane of the sky. In this project we aim to enhance the water fountain sample by identifying objects whose jets are aligned close to the plane of the sky. Methods: We present the results of seven sources observed with the Jansky Very Large Array (JVLA) that were identified as water fountain candidates in an Effelsberg 100 m telescope survey of 74 AGB and early post-AGB stars. Results: We find that our sample of water fountain candidates displays strong variability in their 22 GHz H2O maser spectra. The JVLA observations show an extended bipolar H2O maser outflow for one source, the OH/IR star IRAS 18455+0448. This source was previously classified as a dying OH/IR star based on the exponential decrease of its 1612 MHz OH maser and the lack of H2O masers. We therefore also re-observed the 1612, 1665, and 1667 MHz OH masers. We confirm that the 1612 MHz masers have not reappeared and find that the1665/1667 MHz masers have decreased in strength by several orders of magnitude during the last decade. The JVLA observations also reveal a striking asymmetry in the red-shifted maser emission of IRAS 19422+3506. Conclusions: The OH/IR star IRAS 18455+0448 is confirmed to be a new addition to the

  12. Volcanic jets, plumes, and collapsing fountains: evidence from large-scale experiments, with particular emphasis on the entrainment rate

    NASA Astrophysics Data System (ADS)

    Dellino, P.; Dioguardi, F.; Mele, D.; D'Addabbo, M.; Zimanowski, B.; Büttner, R.; Doronzo, D. M.; Sonder, I.; Sulpizio, R.; Dürig, T.; La Volpe, L.

    2014-06-01

    The source conditions of volcanic plumes and collapsing fountains are investigated by means of large-scale experiments. In the experiments, gas-particle jets issuing from a cylindrical conduit are forced into the atmosphere at different mass flow rates. Dense jets (high particle volumetric concentration, e.g., C 0 > 0.01) generate collapsing fountains, whose height scales with the squared exit velocity. This is consistent with Bernoulli's equation, which is a good approximation if air entrainment is negligible. In this case, kinetic energy is transformed into potential energy without any significant loss by friction with the atmosphere. The dense collapsing fountain, on hitting the ground, generates an intense shear flow similar to a pyroclastic density current. Dilute hot jets (low particle volumetric concentration, e.g., C 0 < 0.01) dissipate their initial kinetic energy at much smaller heights than those predicted by Bernoulli's equation. This is an indication that part of the total mechanical energy is lost by friction with the atmosphere. Significant air entrainment results in this case, leading to the formation of a buoyant column (plume) from which particles settle similarly to pyroclastic fallout. The direct measurement of entrainment coefficient in the experiments suggests that dense collapsing fountains form only when air entrainment is not significant. This is a consequence of the large density difference between the jet and the atmosphere. Cold dilute experiments result in an entrainment coefficient of about 0.06, which is typical of pure jets of fluid dynamics. Hot dilute experiments result in an entrainment coefficient of about 0.11, which is typical of thermally buoyant plumes. The entrainment coefficients obtained by experiments were used as input data in numerical simulations of fountains and plumes. A numerical model was used to solve the classic top-hat system of governing equations, which averages the field variables (e.g., column velocity and

  13. The Application of LT-Table in TRIZ Contradiction Resolving Process

    NASA Astrophysics Data System (ADS)

    Wei, Zihui; Li, Qinghai; Wang, Donglin; Tian, Yumei

    TRIZ is used to resolve invention problems. ARIZ is the most powerful systematic method which integrates all of TRIZ heuristics. Definition of ideal final result (IFR), identification of contradictions and resource utilization are main lines of ARIZ. But resource searching of ARIZ has fault of blindness. Alexandr sets up mathematical model of transformation of the hereditary information in an invention problem using the theory of catastrophes, and provides method of resource searching using LT-table. The application of LT-table on contradiction resolving is introduced. Resource utilization using LT-table is joined into ARIZ step as an addition of TRIZ, apply this method in separator paper punching machine design.

  14. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT LASER TOUCH AND TECHNOLOGIES, LLC LASER TOUCH MODEL LT-B512

    EPA Science Inventory

    The Environmental Technology Verification report discusses the technology and performance of Laser Touch model LT-B512 targeting device manufactured by Laser Touch and Technologies, LLC, for manual spray painting operations. The relative transfer efficiency (TE) improved an avera...

  15. LT and MLT Dependencies of Pc 4 Amplitudes at CPMN Conjugate Stations

    NASA Astrophysics Data System (ADS)

    OBANA, Y.; Yoshikawa, A.; Morris, R. J.; Fraser, B. J.; Olson, J. V.; Solovyev, S. I.; Yumoto, K.

    2001-12-01

    Amplitude of magnetic pulsations observed on the ground can be expressed by B=A F(MLT) f(LT) σ where A is amplitude of source wave, F(MLT) shows MLT dependence of amplitude, f(LT) is a function of ionospheric conductivities at local time of station, and σ is a geological factor at station. In order to clarify F(MLT) and f(LT) of Pc 4 pulsations observed at the Circum-pan Pacific Magnetometer Network (CPMN) conjugate stations, we analyzed the CPMN magnetic data at Chokurdakh (CHD; M.lat.=64.67 deg.,M.lon.=212.12 deg., L=5.46), Kotzebue (KOT; 64.52, 249.72, 5.40), and Macquarie Isl. (MCQ; -64.50, 247.84, 5.40) during the interval of 15 - 17 September, 1994. Contaminated information of F(MLT) and f(LT) can be distributed by estimate the power ratio of CHD-KOT and CHD-MCQ. If we use the magnetic stations in the one-hemisphere, it is difficult to separate F(MLT) and f(LT). However, if we can analyzed data from the magnetic conjugate stations, the f(LT) can be extracted from the observed data, because F(MLT) at the conjugate points must be almost the same. From the analysis, the following results are obtained. (1) The F(MLT) of Pc 4 shows maximum in the prenoon sector and minimum in the afternoon sector. The maximum power is more than 3 times stronger than the minimum power. (2) The f(LT) of Pc 4 has the maximum around 6 and 18 LT, and minimum around 12 LT. The maximum power is 1.59 times stronger than the minimum power. In the present paper, we will compare the F(MLT) of Pc 4 on the ground and in space, and also discuss the LT dependence of obtained f(LT) on the ground.

  16. Field Operations Program - U.S. Postal Service - Fountain Valley Electric Carrier Route Vehicle Testing

    SciTech Connect

    Francfort, J.E.

    2002-01-21

    The United States Postal Service (USPS) has ordered 500 light-duty electric carrier route vehicles (ECRV) mostly for their delivery carriers to use in several California locations. The 500 ECRVs have been defined as a demonstration fleet to support a decision of potentially ordering 5,500 additional ECRVs. Several different test methods are being used by the USPS to evaluate the 500-vehicle deployment. One of these test methods is the ECRV Customer Acceptance Test Program at Fountain Valley, California. Two newly manufactured ECRVs were delivered to the Fountain Valley Post Office and eighteen mail carriers primarily drove the ECRVs on ''park and loop'' mail delivery routes for a period of 2 days each. This ECRV testing consisted of 36 route tests, 18 tests per vehicle. The 18 mail carriers testing the ECRVs were surveyed for the opinions on the performance of the ECRVs. The U.S. Department of Energy, through its Field Operations Program, is supporting the USPS's ECRV testing activities both financially and with technical expertise. As part of this support, Field Operations Program personnel at the Idaho National Engineering and Environmental Laboratory have compiled this report based on the data generated by the USPS and its testing contractor (Ryerson, Master and Associates, Inc.) During the 36 route tests, the two test vehicles were driven a total of 474 miles, averaging 13 mile per test. The distance of the 36 route tests ranged from 4 to 34 miles. Both miles driven and State-of-Charge (SOC) data was collected for only 28 of the route tests. During these 28 tests, the ECRVs were driven a total of 447 miles. The SOC used during the 28 tests averaged a 41% decrease and the average distance driven was 16 miles. This suggests that a 16-mile route uses almost half of the ECRV's battery energy. The 18 carriers also rated 12 ECRV traits that included the physical design of the ECRVs as well as their performance. Based on a scale of 1 being the lowest and 5 being

  17. Field Operations Program - US Postal Service Fountain Valley Electric Carrier Route Vehicle Testing

    SciTech Connect

    Francfort, James Edward

    2002-01-01

    The United States Postal Service (USPS) has ordered 500 light-duty electric carrier route vehicles (ECRV) mostly for their delivery carriers to use in several California locations. The 500 ECRVs have been defined as a demonstration fleet to support a decision of potentially ordering 5,500 additional ECRVs. Several different test methods are being used by the USPS to evaluate the 500-vehicle deployment. One of these test methods is the ECRV Customer Acceptance Test Program at Fountain Valley, California. Two newly manufactured ECRVs were delivered to the Fountain Valey Post Office and eighteen mail carriers primarily drove the ECRVs on "park and loop" mail delivery routes for a period of 2 days each. This ECRV testing consisted of 36 route tests, 18 tests per vehicle. The 18 mail carriers testing the ECRVs were surveyed for the opinions on the performance of the ECRVs. The U.S. Department of Energy, through its Field Operations Program, is supporting the USPS's ECRV testing activities both financially and with technical expertise. As part of this support, Field Operations Program personnel at the Idaho National Engineering and Environmental Laboratory have compiled this report based on the data generated by the USPS and its testing contractor (Ryerson, Master and Associates, Inc.) During the 36 route tests, the two test vehicles were driven a total of 474 miles, averaging 13 mile per test. The distance of the 36 route tests ranged from 4 to 34 miles. Both miles driven and State-of-Charge (SOC) data was collected for only 28 of the route tests. During these 28 tests, the ECRVs were driven a total of 447 miles. The SOC used during the 28 tests averaged a 41% decrease and the average distance driven was 16 miles. This suggests that a 16-mile route uses almost half of the ECRV's battery energy. The 18 carriers also rated 12 ECRV traits that included the physical design of the ECRVs as well as their performance. Based on a scale of 1 being the lowest and 5 being highest

  18. Periglacial Features in the Paleoequatorial Fountain Formation (Permo-Pennsylvanian), Colorado?

    NASA Astrophysics Data System (ADS)

    Sweet, D. E.; Soreghan, G. S.

    2005-12-01

    The Fountain Formation, along the east flank of the Front Range, Colorado, comprises coarse clastics shed as an alluvial wedge off the Ancestral Front range during the Ancestral Rocky Mountains orogeny. Locally, bedding-plane exposures within the Fountain exhibit a distinct geometric pattern composed of white, erosionally resistant ridges 2-10 cm wide and 13-61 cm deep rimming red polygons 15-76 cm across with depth-to-width ratios averaging 5.80. Both the white and the red lithologies comprise very poorly sorted, coarse arkose. However, in thin section, the white lithology exhibits a silicified micro-brecciated texture whereas the red lithology exhibits a diamictite texture with clasts suspended in a muddy matrix comprising ~25% of the rock. FTIR analysis of the <62 micron fraction (matrix) indicates that, relative to one another, the white lithology contains more quartz, whereas the red lithology contains more clay minerals. In addition to the polygons, downwardly tapering, clastic wedges occur locally. The wedges are 10-32 cm in width, penetrate to depths of 41- >220 cm, and have depth-to-width ratios averaging 4.31. Most wedges taper to a single terminus, but some splay downward. Granular to coarse arkosic sandstone fills wedges and locally exhibits a faint vertical foliation; laminae within host strata commonly bend upward adjacent to wedge edges. These preliminary data are most consistent with the hypothesis that both features relate to thermal contraction wherein the polygonal features represent fossil patterned ground and the clastic wedges record ice-wedge or seasonal frost crack casts. The color contrast is a diagenetic enhancement, the result of bleaching of the original polygonal surface by reducing fluids channeled by permeability contrasts between the muddy arkose (red) and the granule fills (now white). Contractional polygonal fractures have been related to (1) desiccation in an arid environment with either mud or evaporites providing cohesion and (2

  19. Quantum Dynamics in Atomic-Fountain Experiments for Measuring the Electric Dipole Moment of the Electron with Improved Sensitivity

    NASA Astrophysics Data System (ADS)

    Wundt, B. J.; Munger, C. T.; Jentschura, U. D.

    2012-10-01

    An improved measurement of the electron electric dipole moment (EDM) appears feasible using ground-state alkali atoms in an atomic fountain in which a strong electric field, which couples to a conceivable EDM, is applied perpendicular to the fountain axis. In a practical fountain, the ratio of the atomic tensor Stark shift to the Zeeman shift is a factor μ˜100. We expand the complete time-evolution operator in inverse powers of this ratio; complete results are presented for atoms of total spin F=3, 4, and 5. For a specific set of entangled hyperfine sublevels (coherent states), potential systematic errors enter only as even powers of 1/μ, making the expansion rapidly convergent. The remaining EDM-mimicking effects are further suppressed in a proposed double-differential setup, where the final state is interrogated in a differential laser configuration, and the direction of the strong electric field also is inverted. Estimates of the signal available at existing accelerator facilities indicate that the proposed apparatus offers the potential for a drastic improvement in EDM limits over existing measurements, and for constraining the parameter space of supersymmetric (SUSY) extensions of the Standard Model.

  20. A novel formulation of L-thyroxine (L-T4) reduces the problem of L-T4 malabsorption by coffee observed with traditional tablet formulations.

    PubMed

    Vita, Roberto; Saraceno, Giovanna; Trimarchi, Francesco; Benvenga, Salvatore

    2013-02-01

    The purpose of this work is to evaluate if the coffee-associated malabsorption of tablet levothyroxine (L-T4) is reduced by soft gel capsule. We recruited 8 patients with coffee-associated L-T4 malabsorption including one hypothyroid patient. For 6 months, the patients were switched to the capsule maintaining the L-T4 daily dose. Patients took the capsule with water, having coffee 1 h later (proper habit, PH) on days 1-90, or with coffee ≤ 5 min later (improper habit, IH) on days 91-180. After 6 months, 2 patients volunteered for an acute loading test of 600 μg L-T4 (capsule) ingested with water (PH) or with coffee (IH). In the single hypothyroid patient, the post-switch TSH ranged 0.06-0.16 mU/L (PH) versus 5.8-22.4 mU/L pre-switch (PH) and 0.025-0.29 mU/L (IH) versus 26-34 mU/L pre-switch (IH). In the other 7 patients, post-switch TSH was 0.41 ± 0.46 (PH) versus 0.28 ± 0.20 pre-switch (PH) (P = 0.61) and 0.34 ± 0.30 (IH) versus 1.23 ± 1.47 pre-switch (IH) (P < 0.001). Importantly, TSH levels in PH versus IH habit did not differ post-switch (P = 0.90), but they did pre-switch (P < 0.0001). The proportions of post-switch TSH levels <0.10 mU/L with PH (33.3 %) or with IH (33.3 %) were borderline significantly greater than the corresponding pre-switch levels with PH (10.3 %) (P = 0.088) or with IH (0 %) (P = 0.0096). In the two volunteers, the L-T4 loading test showed that coffee influenced L-T4 pharmacokinetics minimally. Soft gel capsules can be used in patients who are unable/unwilling to change their IH of taking L-T4. PMID:22932947

  1. High Velocity Precessing Jet from the Water Fountain IRAS 18286-0959 Revealed by VLBA Observations

    NASA Astrophysics Data System (ADS)

    Yung, Bosco; Nakashima, J.; Imai, H.; Deguchi, S.; Diamond, P. J.; Kwok, S.

    2011-05-01

    We report the multi-epoch VLBA observations of 22.2GHz water maser emission associated with the "water fountain" star IRAS 18286-0959. The detected maser emission are distributed in the velocity range from -50km/s to 150km/s. The spatial distribution of over 70% of the identified maser features is found to be highly collimated along a spiral jet (namely, jet 1) extended from southeast to northwest direction, and the rest of the features appear to trace another spiral jet (jet 2) with a different orientation. The two jets form a "double-helix" pattern which lies across 200 milliarcseconds (mas). The maser features are reasonably fit by a model consisting of two precessing jets. The velocities of jet 1 and jet 2 are derived to be 138km/s and 99km/s, respectively. The precession period of jet 1 is about 56 years, and for jet 2 it is about 73 years. We propose that the appearance of two jets observed are the result of a single driving source with a significant proper motion. This research was supported by grants from the Research Grants Council of the Hong Kong Special Administrative Region, China, the Seed Funding Programme for Basic Research of the University of Hong Kong, Grant-in-Aid for Young Scientists from the Ministry 9 of Education, Culture, Sports, Science, and Technology, and Grant-in-Aid for Scientific Research from Japan Society for Promotion Science.

  2. Galactic fountains and outflows in star forming dwarf galaxies: ISM expulsion and chemical enrichment

    NASA Astrophysics Data System (ADS)

    Melioli, Claudio

    2015-08-01

    We investigated the impact of supernova feedback in gas-rich dwarf galaxies experiencing a low-to-moderate star formation rate, typical of relatively quiescent phases between starbursts. We calculated the long term evolution of the ISM and the metal-rich SN ejecta using 3D hydrodynamical simulations, in which the feedback energy is deposited by SNII exploding in distinct OB associations. We found that a circulation flow similar to galactic fountains is generally estabilished, with some ISM lifted at heights of one to few kpc above the galactic plane. This gas forms an extra-planar layer, which falls back to the plane in about 108 yr, once the star formation stops. Very little or no ISM is expelled outside the galaxy system for the considered SFRs, even though in the most powerful model the SN energy is comparable to the gas binding energy. The metal-rich SN ejecta is instead more vulnerable to the feedback and we found that a significant fraction (25-80%) is vented in the intergalactic medium, even for low SN rate. About half of the metals retained by the galaxy are located far (z > 500 pc) from the galactic plane. Moreover, our models indicate that the circulation of the metal-rich gas out from and back to the galactic disk is not able to erase the chemical gradients imprinted by the (centrally concentrated) SN explosions.

  3. RADIATION-DRIVEN FOUNTAIN AND ORIGIN OF TORUS AROUND ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Wada, Keiichi

    2012-10-10

    We propose a plausible mechanism to explain the formation of the so-called obscuring tori around active galactic nuclei (AGNs) based on three-dimensional hydrodynamic simulations including radiative feedback from the central source. The X-ray heating and radiation pressure on the gas are explicitly calculated using a ray-tracing method. This radiation feedback drives a 'fountain', that is, a vertical circulation of gas in the central few to tens parsecs. Interaction between the non-steady outflows and inflows causes the formation of a geometrically thick torus with internal turbulent motion. As a result, the AGN is obscured for a wide range of solid angles. In a quasi-steady state, the opening angles for the column density toward a black hole <10{sup 23} cm{sup -2} are approximately {+-}30 Degree-Sign and {+-}50 Degree-Sign for AGNs with 10% and 1% Eddington luminosity, respectively. Mass inflows through the torus coexist with the outflow and internal turbulent motion, and the average mass accretion rate to the central parsec region is 2 Multiplication-Sign 10{sup -4} {approx} 10{sup -3} M{sub Sun} yr{sup -1}; this is about 10 times smaller than accretion rate required to maintain the AGN luminosity. This implies that relatively luminous AGN activity is intrinsically intermittent or that there are other mechanisms, such as stellar energy feedback, that enhance the mass accretion to the center.

  4. Lonely drinking fountains and comforting coolers: paradoxes of water value and ironies of water use.

    PubMed

    Kaplan, Martha

    2011-01-01

    This article focuses ethnographically on Americans and technologies of drinking water, as tokens of and vehicles for health, agency, and surprising kinds of community. Journalists and water scholars have argued that bottled water is a material concomitant of privatization and alienation in U.S. society. But, engaging Latour, this research shows that water technologies and the groups they assemble, are plural. Attention to everyday entwining of workplace lives with drinking fountains, single-serve bottles, and spring water coolers shows us several different quests, some individualized, some alienated, but some seeking health via public, collective care, acknowledgment of stakeholding, and community organizing. Focused on water practices on a college campus, in the roaring 1990s and increasingly sober 2000s in the context of earlier U.S. water histories of inclusion and exclusion, I draw on ethnographic research from the two years that led up to the recession and the presidential election of 2008. I argue for understanding of water value through attention to water use, focusing both on the social construction of water and the use of water for social construction. PMID:22171409

  5. The Fountain of Health: Bringing Seniors’ Mental Health Promotion into Clinical Practice

    PubMed Central

    Thoo, Vanessa; Freer, Janya; Cassidy, Keri-Leigh

    2015-01-01

    Background The Fountain of Health (FoH) initiative offers valuable evidence-based mental health knowledge and provides clinicians with evaluated tools for translating knowledge into practice, in order to reduce seniors’ risks of mental disorders, including dementia. Methods A presentation on mental health promotion and educational materials were disseminated to mental health clinicians including physicians and other allied health professionals either in-person or via tele-education through a provincial seniors’ mental health network. Measures included: 1) a tele-education quality evaluation form, 2) a knowledge transfer questionnaire, 3) a knowledge translation-to-practice evaluation tool, and 4) a quality assurance questionnaire. Results A total of 74 mental health clinicians received the FoH education session. There was a highly significant (p < .0001) difference in clinicians’ knowledge transfer questionnaire scores pre- and post-educational session. At a two-month follow-up, 19 (25.7%) participants completed a quality assurance questionnaire, with all 19 (100%) of respondents stating they would positively recommend the FoH information to colleagues and patients. Eleven (20.4%) translation-to-practice forms were also collected at this interval, tracking clinician use of the educational materials. Conclusions The use of a formalized network for knowledge transfer allows for education and evaluation of health-care practitioners in both acquisition of practical knowledge and subsequent clinical behavior change. PMID:26740830

  6. Improved tests of local position invariance using 87Rb and 133Cs fountains.

    PubMed

    Guéna, J; Abgrall, M; Rovera, D; Rosenbusch, P; Tobar, M E; Laurent, Ph; Clairon, A; Bize, S

    2012-08-24

    We report tests of local position invariance based on measurements of the ratio of the ground state hyperfine frequencies of 133Cs and 87Rb in laser-cooled atomic fountain clocks. Measurements extending over 14 years set a stringent limit to a possible variation with time of this ratio: d ln(ν(Rb)/ν(Cs))/dt=(-1.39±0.91)×10(-16) yr(-1). This improves by a factor of 7.7 over our previous report [H. Marion et al., Phys. Rev. Lett. 90, 150801 (2003)]. Our measurements also set the first limit to a fractional variation of the Rb/Cs frequency ratio with gravitational potential at the level of c(2)d ln(ν(Rb)/ν(Cs))/dU=(0.11±1.04)×10(-6), providing a new stringent differential redshift test. The above limits equivalently apply to the fractional variation of the quantity α(-0.49)(g(Rb)/g(Cs)), which involves the fine-structure constant α and the ratio of the nuclear g-factors of the two alkalis. The link with variations of the light quark mass is also presented together with a global analysis combining other available highly accurate clock comparisons. PMID:23002732

  7. Herschel/HIFI CO, ^{13}CO and H_2O thermal emission in Water Fountain stars

    NASA Astrophysics Data System (ADS)

    García-García, E.; Rizzo, J. R.; Gómez, J. F.

    2015-05-01

    Water fountain stars are low- and intermediate-mass (0.8-8 M_⊙) evolved object whose water maser emission trace high velocity (>100 km s^{-1}) bipolar jets. They can be found in late AGB phase up to young PNe, although most of them are in the post-AGB phase. These stars may be key objects to understand how planetary nebulae are shaped. Besides the jets, WFs are expected to be surrounded by a large envelope expelled during the AGB and, in some cases, by a circumstellar toroid. We present a study of thermal lines (mid and high-J CO and ^{13}CO, and the lowest transitions of H_2O) from 8 WFs with the Herschel Space Observatory, in order to characterise their circumstellar material. The detected lines have been analysed with LTE and LVG models, to obtain the parameters of their circumstellar envelops. Our results also suggest the presence of thermal emission associated with the outflows. Isotope ratios of CO are compared with those in other post-AGB stars.

  8. Atomic fountain of laser-cooled Yb atoms for precision measurements

    SciTech Connect

    Pandey, Kanhaiya; Rathod, K. D.; Singh, Alok K.; Natarajan, Vasant

    2010-10-15

    We demonstrate launching of laser-cooled Yb atoms in a cold atomic fountain. Atoms in a collimated thermal beam are first cooled and captured in a magneto-optical trap (MOT) operating on the strongly allowed {sup 1}S{sub 0}{yields}{sup 1}P{sub 1} transition at 399 nm (blue line). They are then transferred to a MOT on the weakly allowed {sup 1}S{sub 0}{yields}{sup 3}P{sub 1} transition at 556 nm (green line). Cold atoms from the green MOT are launched against gravity at a velocity of around 2.5 m/s using a pair of green beams. We trap more than 10{sup 7} atoms in the blue MOT and transfer up to 70% into the green MOT. The temperature for the odd isotope {sup 171}Yb is {approx}1 mK in the blue MOT, and reduces by a factor of 40 in the green MOT.

  9. Polar Wind in the Context of the Auroral Plasma Fountain for 2 to 8 RE

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Giles, B. L.; Chandler, M. O.; Chappell, C. R.; Craven, P. D.; Su, Y.-J.; Horwitz, J. L.; Pollock, C. J.

    1997-01-01

    Operations of the POLAR Plasma Source Instrument have provided adequate observing time with controlled spacecraft potential to begin a 3D characterization of the polar wind as it exists in the context of the auroral plasma fountain. The principal periods of such polar wind observation to date have been 15-18 Apr. 96, 28 may 96, 14 Jun. - 6 Sep. 96, 17-29 Mar. 97, 29 May - 12 Jun. 97, 13-27 Aug. 97. Separate observations have been made near 2 RE geocentric in the south polar perigee passes and between 6-8 RE geocentric in the north polar apogee passes. Analyses of data from the Thermal Ion Dynamics Experiment during these periods are used to characterize the altitude, local time, and invariant latitude distribution of the polar wind. Data from these and other periods are used to establish the auroral plasma heating context within which the polar wind outflows exist. The available data will be used to address the temporal variability of the polar wind during the period of operations to date. Comparisons between the observations and a coupled fluid-semikinetic model are used to interpret the observed spatial structure and temporal variability.

  10. UTC(OP) based on LNE-SYRTE atomic fountain primary frequency standards

    NASA Astrophysics Data System (ADS)

    Rovera, G. D.; Bize, S.; Chupin, B.; Guéna, J.; Laurent, Ph; Rosenbusch, P.; Uhrich, P.; Abgrall, M.

    2016-06-01

    UTC(OP), the French national realization of the international coordinated universal time, was redesigned and rebuilt. The first step was the implementation in October 2012 of a new algorithm based on a H-maser and on atomic fountain data. Thanks to the new implementation, the stability of UTC(OP) was dramatically improved and UTC(OP) competes with the best time scales available today. Then the hardware generation and distribution of the UTC(OP) physical signals were replaced. Part of the new hardware is composed of commercial devices, but the key elements were specifically developed. One of them is a special switch that allows the UTC(OP) signals to be derived from one of two time scales, based on two different H-masers, which are generated simultaneously. This insures the continuity of the UTC(OP) signal even when a change of the reference H-maser is required. With the new hardware implementation, UTC(OP) is made available through three coherent signals: 100 MHz, 10 MHz and 1 PPS. For more than 3 years, UTC(OP) remained well below 10 ns close to UTC, with a difference even less than 5 ns if we except a short period around MJD 56650.

  11. L-T4 bioequivalence and hormone replacement studies via feedback control simulations.

    PubMed

    Eisenberg, Marisa; Samuels, Mary; DiStefano, Joseph J

    2006-12-01

    FDA Guidance for testing bioequivalence of levothyroxine (L-T(4)) preparations has been challenged by several groups, based on multiple issues. The efficacy of single versus combined hormone therapy also is receiving additional scrutiny. To examine these concerns, we developed a new nonlinear feedback system simulation model of whole-body regulation mechanisms involving dynamics of T(3), T(4), TSH, plasma protein binding, extravascular regulatory enzyme systems, and the hypothalamic-pituitary-thyroid axis, all quantified from human data. To address bioequivalence, we explored how to best account for varying and unmeasured endogenous T(4) following dosing with exogenous oral L-T(4) in euthyroid volunteers in required pharmacokinetic (PK) studies, by simulating various dosing scenarios and developing a new and simple correction method. We computed and assessed dosing error effects and baseline corrections using simulator-predicted endogenous T(4) level variations, due to actual closed-loop effects, and compared these with approximate corrections computed directly from PK data. Predicted dose-responses were quite linear, and for constant baseline, 7-day half-life, and our new formula-correction methods, we established some bounds on bioequivalent dosages. Simulated replacement after thyroidectomy required 141 microg L-T(4) only to normalize T(3) tissue levels and 162 microg L-T(4) to normalize plasma T(3) levels. A combined dose of approximately 103 microg L-T(4) plus approximately 6 microg T(3) ( approximately 18:1 ratio) was needed to normalize both plasma T(3) and T(4) and average tissue T(3) levels. However, simulated average tissue T(3) levels were normalized with standard L-T(4)-only therapy, and plasma T(3) levels were still within the normal range. We suggest a simple and more accurate correction for endogenous T(4) in PK studies. Current standard L-T(4)-only treatment is supported for routine replacement needs. PMID:17199439

  12. CysLT1R Antagonists Inhibit Tumor Growth in a Xenograft Model of Colon Cancer

    PubMed Central

    Savari, Sayeh; Liu, Minghui; Zhang, Yuan; Sime, Wondossen; Sjölander, Anita

    2013-01-01

    The expression of the inflammatory G-protein coupled receptor CysLT1R has been shown to be upregulated in colon cancer patients and associated with poor prognosis. The present study investigated the correlation between CysLT1R and colon cancer development in vivo using CysLT1R antagonists (ZM198,615 or Montelukast) and the nude mouse xenograft model. Two drug administration regimens were established. The first regimen was established to investigate the importance of CysLT1R in tumor initiation. Nude mice were inoculated with 50 µM CysLT1R antagonist-pretreated HCT-116 colon cancer cells and received continued treatment (5 mg/kg/day, intraperitoneally). The second regimen aimed to address the role of CysLT1R in tumor progression. Nude mice were inoculated with non-pretreated HCT-116 cells and did not receive CysLT1R antagonist treatment until recordable tumor appearance. Both regimens resulted in significantly reduced tumor size, attributed to changes in proliferation and apoptosis as determined by reduced Ki-67 levels and increased levels of p21WAF/Cip1 (P<0.01), cleaved caspase 3, and the caspase-cleaved product of cytokeratin 18. Decreased levels of VEGF (P<0.01) and reduced vessel size (P<0.05) were also observed, the latter only in the ZM198,615-pretreatment group. Furthermore, we performed a series of in vitro studies using the colon cancer cell line HCT-116 and CysLT1R antagonists. In addition to significant reductions in cell proliferation, adhesion and colony formation, we observed induction of cell cycle arrest and apoptosis in a dose-dependent manner. The ability of Montelukast to inhibit growth of human colon cancer xenograft was further validated by using two additional colon cancer cell lines, SW-480 and HT-29. Our results demonstrate that CysLT1R antagonists inhibit growth of colon cancer xenografts primarily by reducing proliferation and inducing apoptosis of the tumor cells. PMID:24039952

  13. Comparative analysis of SV40 17kT and LT function in vivo demonstrates that LT's C-terminus re-programs hepatic gene expression and is necessary for tumorigenesis in the liver

    PubMed Central

    Comerford, S A; Schultz, N; Hinnant, E A; Klapproth, S; Hammer, R E

    2012-01-01

    Transformation by Simian Virus 40 (SV40) large T antigen (LT) is mediated in large part by its interaction with a variety of cellular proteins at distinct binding domains within LT. While the interaction of LT's N-terminus with the tumor suppressor Rb is absolutely required for LT-dependent transformation, the requirement for the interaction of LT's C-terminus with p53 is less clear and cell- and context-dependent. Here, we report a line of transgenic mice expressing a doxycycline-inducible liver-specific viral transcript that produces abundant 17kT, a naturally occurring SV40 early product that is co-linear with LT for the first 131 amino acids and that binds to Rb, but not p53. Comparative analysis of livers of transgenic mice expressing either 17kT or full length LT demonstrates that 17kT stimulates cell proliferation and induces hepatic hyperplasia but is incapable of inducing hepatic dysplasia or promoting hepatocarcinogenesis. Gene expression profiling demonstrates that 17kT and LT invoke a set of shared molecular signatures consistent with the action of LT's N-terminus on Rb-E2F-mediated control of hepatocyte transcription. However, 17kT also induces a unique set of genes, many of which are known transcriptional targets of p53, while LT actively suppresses them. LT also uniquely deregulates the expression of a subset of genes within the imprinted network and rapidly re-programs hepatocyte gene expression to a more fetal-like state. Finally, we provide evidence that the LT/p53 complex provides a gain-of-function for LT-dependent transformation in the liver, and confirm the absolute requirement for LT's C-terminus for liver tumor development by demonstrating that phosphatase and tensin homolog (PTEN)-deficiency readily cooperates with LT, but not 17kT, for tumorigenesis. These results confirm independent and inter-dependent functions for LT's N- and C-terminus and emphasize differences in the requirements for LT's C-terminus in cell-type dependent

  14. Polarized structure function sigma_lt' for kaon electroproduction in the nucleon resonance region

    SciTech Connect

    Rakhsha Nasseripour; B. Raue; Daniel Carman; Pawel Ambrozewicz

    2008-02-19

    The first measurements of the polarized structure function $\\sigma_{LT'}$ for the reaction $p(\\vec e,e'K^+)\\Lambda$ in the nucleon resonance region are reported. Measurements are included from threshold up to $W$=2.05~GeV for central values of $Q^2$ of 0.65 and 1.00~GeV$^2$, and nearly the entire kaon center-of-mass angular range. $\\sigma_{LT'}$ is the imaginary part of the longitudinal-transverse response and is expected to be sensitive to interferences between competing intermediate $s$-channel resonances, as well as resonant and non-resonant processes. The results for $\\sigma_{LT'}$ are comparable in magnitude to previously reported results from CLAS for $\\sigma_{LT}$, the real part of the same response. An intriguing sign change in $\\sigma_{LT'}$ is observed in the high $Q^2$ data at $W\\approx 1.9$~GeV. Comparisons to several existing model predictions are shown.

  15. Evaluation of fecal contamination by human and ruminant sources in upper Fountain Creek, Colorado, 2007-2008, by using multiple lines of evidence:

    USGS Publications Warehouse

    Stoeckel, Donald

    2011-01-01

    Fountain Creek is a high-gradient stream on the Front Range of the Rocky Mountains in Colorado. The headwaters of Fountain Creek drain Pikes Peak, a major destination for tourism. Fountain Creek is a drinking-water source for the City of Colorado Springs, Colorado, and is used for irrigation, recreation, and other purposes between Colorado Springs and the confluence with the Arkansas River at Pueblo, Colorado. In 2008, Fountain Creek was placed on the Colorado 303(d) list of impaired streams because of fecal contamination. Colorado uses a 30-day geometric mean standard of 126 Escherichia coli per 100 milliliters as its management goal for recreational waters. The objective of this study was to identify major sources of Escherichia coli in upper Fountain Creek during exceedances of the State recreational water standard. To meet this objective, a new approach was developed and tested that uses genetic marker analysis for microbial source tracking, along with other information, to evaluate potential contributions of fecal contamination from various sources.

  16. Coupled textural and compositional characterization of basaltic scoria: Insights into the transition from Strombolian to fire fountain activity at Mount Etna, Italy

    NASA Astrophysics Data System (ADS)

    Polacci, Margherita; Corsaro, Rosa Anna; Andronico, Daniele

    2006-03-01

    Strombolian and fire fountain activities represent a common expression of explosive basaltic eruptions. However, the transition between these two eruptive styles and their source mechanisms are still debated. We use textural and compositional studies to characterize pyroclastic material from both the Strombolian and Hawaiian-style fire fountain phases of the January June 2000 Etna activity. We find that basaltic scoria presents distinctive textural and compositional features that reflect different modes of magma vesiculation and crystallization in the two eruptive regimes. Overall, magma that forms Strombolian scoria is far more crystallized, less vesicular, and more evolved, indicating strong volatile depletion and longer residence time before being erupted. Fire fountain scoria indicates a fast-rising magma with evidence of moderate syneruptive volatile exsolution. The new textural and compositional data set is integrated with previous volcanological and geophysical investigations to provide further insights into the dynamics of fire fountains, and to frame the transition from Strombolian explosions to fire fountain activity into a model that may apply to future eruptions at Mount Etna as well as other active basaltic volcanoes.

  17. VLA Monitoring of the Water Masers in the Water Fountain Nebula IRAS16342-3814

    NASA Astrophysics Data System (ADS)

    Fagrelius, Eric; Claussen, M.; Sahai, R.; Morris, M.

    2010-01-01

    This study of water maser emission from the "water fountain" pre-planetary nebula IRAS16342-3814 used 1.35 cm observations made with the Very Large Array of the National Radio Astronomy Observatory. Seven observing epochs over one year sampled an LSR velocity range of 370 km/sec (since masers are known over a range of more than 250 km/s). The wide range reveals maser spots at several different velocities, including the well-known features at extreme red-shifted ( LSR +180 km/sec) and blue-shifted ( LSR -66 km/sec) velocities, relative to the stellar velocity. Identification of maser spots over time gives a better picture of the growth, orientation, and physical nature of the bipolar outflow lobes. The data reveals maser spots at previously unreported velocities ( LSR -10 to +5 km/s). Some maser spots identified in the past are no longer seen. Masers from different velocity ranges differ in intensity by 100x. Within the year, some individual masers vary in intensity by 10x. Besides revealing growth and decline of the different masers, we hoped to observe the separation of the extremely shifted masers. Previous studies measured about 3 arcsec in breadth. The angular resolution of the VLA images was typically 0.7 - 1.2 arcseconds, and the data were imaged with 0.2 arcsec per pixel, so we expected to resolve the separation of extremely shifted masers by 15 pixels. This separation was not observed. Existing, near-simultaneous observations with the Very Large Baseline Array will be used to investigate this expected separation. This research was performed under the National Science Foundation's Research Experience for Teachers program during the summer of 2009. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. RS and MM were funded by a Long Term Space Astrophysics award from NASA for this work

  18. Lava discharge during Etna's January 2011 fire fountain tracked using MSG-SEVIRI

    NASA Astrophysics Data System (ADS)

    Gouhier, Mathieu; Harris, Andrew; Calvari, Sonia; Labazuy, Philippe; Guéhenneux, Yannick; Donnadieu, Franck; Valade, Sébastien

    2012-05-01

    Etna's January 2011 eruption provided an excellent opportunity to test the ability of Meteosat Second Generation satellite's Spinning Enhanced Visible and InfraRed Imager (SEVIRI) sensor to track a short-lived effusive event. The presence of lava fountaining, the rapid expansion of lava flows, and the complexity of the resulting flow field make such events difficult to track from the ground. During the Etna's January 2011 eruption, we were able to use thermal data collected by SEVIRI every 15 min to generate a time series of the syn-eruptive heat flux. Lava discharge waxed over a ~1-h period to reach a peak that was first masked from the satellite view by a cold tephra plume and then was of sufficient intensity to saturate the 3.9-μm channel. Both problems made it impossible to estimate time-averaged lava discharge rates using the syn-eruptive heat flux curve. Therefore, through integration of data obtained by ground-based Doppler radar and thermal cameras, as well as ancillary satellite data (from Moderate Resolution Imaging Spectrometer and Advanced Very High Resolution Radiometer), we developed a method that allowed us to identify the point at which effusion stagnated, to allow definition of a lava cooling curve. This allowed retrieval of a lava volume of ~1.2 × 106 m3, which, if emitted for 5 h, was erupted at a mean output rate of ~70 m3 s-1. The lava volume estimated using the cooling curve method is found to be similar to the values inferred from field measurements.

  19. Broadening and shifting of Bragg reflections of nanoscale-microtwinned LT-Ni3Sn2

    NASA Astrophysics Data System (ADS)

    Leineweber, Andreas; Krumeich, Frank

    2013-12-01

    The effect of nanoscale microtwinning of long-range ordered domains in LT-Ni3Sn2 on its diffraction behaviour was studied by X-ray powder diffraction and electron microscopy. LT-Ni3Sn2 exhibits a Ni2In/NiAs-type structure with a superstructure breaking the symmetry relative to the hexagonal high-temperature (HT) to the orthorhombic low-temperature (LT) phase, implying three different twin-domain orientations. The microstructure was generated by annealing HT-Ni3Sn2 considerably below the order-disorder transition temperature, establishing the LT phase avoiding too much domain coarsening. High-resolution electron microscopy reveals domain sizes of 100-200 Å compatible with the Scherrer broadening of the superstructure reflections recorded by X-ray diffraction. Whereas the orthorhombic symmetry of the LT phase leads in powder-diffraction patterns from coarse-domain size material to splitting of the fundamental reflections, this splitting does not occur for the LT-Ni3Sn2 with nanoscale domains. Instead, a (pseudo)hexagonal indexing is possible giving hexagonal lattice parameters, which are, however, incompatible with the positions of the superstructure reflections. This can be attributed to interference between X-rays scattered by the differently oriented, truly orthorhombic domains leading to merging of the fundamental reflections. These show pronounced anisotropic microstrain-like broadening, where the integral breadths ? on the reciprocal d-spacing scale of a series of higher order reflection increase in a non-linear fashion with upward curvature with the reciprocal d-spacings ? of these reflections. Such a type of unusual microstrain broadening appears to be typical for microstructures which are inhomogeneous on the nanoscale, and in which the structural inhomogeneities lead to small phase shifts of the scattered radiation from different locations (e.g. domains).

  20. A Search for L/T Transition Dwarfs with Pan-STARRS1 and WISE. II. L/T Transition Atmospheres and Young Discoveries

    NASA Astrophysics Data System (ADS)

    Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Deacon, Niall R.; Aller, Kimberly M.; Redstone, Joshua; Burgett, W. S.; Chambers, K. C.; Draper, P.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Metcalfe, N.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.

    2015-12-01

    The evolution of brown dwarfs from L to T spectral types is one of the least understood aspects of the ultracool population, partly for lack of a large, well-defined, and well-characterized sample in the L/T transition. To improve the existing census, we have searched ≈28,000 deg2 using the Pan-STARRS1 and Wide-field Infrared Survey Explorer surveys for L/T transition dwarfs within 25 pc. We present 130 ultracool dwarf discoveries with estimated distances ≈9-130 pc, including 21 that were independently discovered by other authors and 3 that were previously identified as photometric candidates. Seventy-nine of our objects have near-IR spectral types of L6-T4.5, the most L/T transition dwarfs from any search to date, and we have increased the census of L9-T1.5 objects within 25 pc by over 50%. The color distribution of our discoveries provides further evidence for the “L/T gap,” a deficit of objects with (J - K)MKO ≈ 0.0-0.5 mag in the L/T transition, and thus reinforces the idea that the transition from cloudy to clear photospheres occurs rapidly. Among our discoveries are 31 candidate binaries based on their low-resolution spectral features. Two of these candidates are common proper motion companions to nearby main sequence stars; if confirmed as binaries, these would be rare benchmark systems with the potential to stringently test ultracool evolutionary models. Our search also serendipitously identified 23 late-M and L dwarfs with spectroscopic signs of low gravity implying youth, including 10 with vl-g or int-g gravity classifications and another 13 with indications of low gravity whose spectral types or modest spectral signal-to-noise ratio do not allow us to assign formal classifications. Finally, we identify 10 candidate members of nearby young moving groups (YMG) with spectral types L7-T4.5, including three showing spectroscopic signs of low gravity. If confirmed, any of these would be among the coolest known YMG members and would help to determine

  1. Lidar measurements carried out during the 28 February 2013 lava fountain event at Mt. Etna, in Italy

    NASA Astrophysics Data System (ADS)

    Scollo, Simona; Boselli, Antonella; Coltelli, Mauro; Leto, Giuseppe; Pisani, Gianluca; Spinelli, Nicola; Wang, Xuan; Zanmar Sanchez, Ricardo

    2015-04-01

    Mt. Etna, in Italy, is one of the most active volcanoes in the world. Since 2011, the New South East Crater produced lava fountains that formed eruption columns rising up to several kilometers above sea level and fine ash dispersed hundreds kilometers away from the central craters. One of these events occurred during the 28 February 2013. The volcanic plume was directed toward the E and reached, during the climax phase, an height greater than 9 km above sea level. Lidar measurements were performed immediately after the lava fountain activity by a new portable Raman scanning Lidar system that is operating in Catania since 2013. The Lidar is operated at the Serra La Nave station, only 7 km away far from the Etna summits, and, during the winter seasons, at the INAF-Astrophysical Observatory in Catania. The Lidar named AMPLE is a portable multiwavelength scanning lidar system with depolarization measurement capability, able to carry out high quality 3D map of particle optical and microphysical properties. The laser source is a doubled and tripled diode pumped Nd:YAG laser, with a repetition rate of 1KHz. The Lidar system detects the elastic Lidar returns at 355nm and the N2 Raman Lidar echoes at 386nm. Each signal is acquired with a raw spatial resolution varying from 30cm to 30m. Results of the measurements performed on 28 February 2013 show different layers: the first layer below 1.5 km corresponds to smaller not depolarizing particles of local origin while the layer up to 7 km, is related to volcanic ash coming from Etna. A discrimination between spherical and non-spherical particles in the volcanic plume is clear from the aerosol depolarization values in the atmospheric column interested by the volcanic plume. Some differences in the aerosol size and typology are also highlighted by the Lidar Ratio values. Lidar measurements presented here show new insights on the plume dynamics during Etna lava fountain events.

  2. Superfund record of decision (EPA Region 4): Beaunit Circular Knit and Dyeing, Greenville County, Fountain Inn, SC, September 29, 1995

    SciTech Connect

    1996-03-01

    This decision document presents the selected remedial action for the Beaunit Circular Knit and Dying Superfund Site (the Site) in Fountain Inn, South Carolina. The major components of the selected remedy include: containment of soils and sediments contaminated with volatile organic compounds (VOCs) and metals by capping of the lagoon area; and additional monitoring of groundwater and soils on a regular schedule to determine effects of construction of lagoon cap, and to insure effectiveness of cap after construction. Modifications to the frequency or termination of continued monitoring will be determined during the Remedial Action and the Five Year Review.

  3. Testing Local Position Invariance with Four Cesium-Fountain Primary Frequency Standards and Four NIST Hydrogen Masers

    SciTech Connect

    Ashby, N.; Heavner, T. P.; Jefferts, S. R.; Parker, T. E.; Radnaev, A. G.; Dudin, Y. O.

    2007-02-16

    We report the most sensitive tests to date of the assumption of local position invariance (LPI) underlying general relativity, based on a 7 yr comparison of cesium and hydrogen atomic clocks (frequency standards). The latest results place an upper limit that is over 20 times smaller than the previous most sensitive tests; this is consistent with the null shift predicted by LPI. The result is based on precise comparisons of frequencies of four hydrogen masers maintained by NIST, with four independent Cs fountain clocks--one at NIST and three in Europe--as the Sun's gravitational potential at Earth's surface varies due to Earth's orbital eccentricity.

  4. Clinical coding. Code breakers.

    PubMed

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships. PMID:15768716

  5. LOW TEMPERATURE THERMAL TREATMENT (LT3®) TECHNOLOGY - ROY F. WESTON, INC. - APPLICATIONS ANALYSIS REPORT

    EPA Science Inventory

    This report evaluates the Low Temperature Thermal Treatment (LT3®) system's ability to remove VOC and SVOC compounds from solid wastes. This evaluation is based on treatment performance and cost data from the Superfund Innovative Technology (SITE) demonstration and fi...

  6. TSH-Based Protocol, Tablet Instability, and Absorption Effects on L-T4 Bioequivalence

    PubMed Central

    DiStefano, Joseph J.

    2009-01-01

    Background FDA Guidance for pharmacokinetic (PK) testing of levothyroxine (L-T4) for interbrand bioequivalence has evolved recently. Concerns remain about efficacy and safety of the current protocol, based on PK analysis following supraphysiological L-T4 dosing in euthyroid volunteers, and recent recalls due to intrabrand manufacturing problems also suggest need for further refinement. We examine these interrelated issues quantitatively, using simulated what-if scenarios testing efficacy of a TSH-based protocol and tablet stability and absorption, to enhance precision of L-T4 bioequivalence methods. Methods We use an updated simulation model of human thyroid hormone regulation quantified and validated from data that span a wide range of normal and abnormal thyroid system function. Bioequivalence: We explored a TSH-based protocol, using normal replacement dosing in simulated thyroidectomized patients, switching brands after 8 weeks of full replacement dosing. We simulated effects of tablet potency differences and intestinal absorption differences on predicted plasma TSH, T4, and triiodothyronine (T3) dynamics. Stability: We simulated effects of potency decay and lot-by-lot differences in realistic scenarios, using actual tablet potency data spanning 2 years, comparing the recently reduced 95–105% FDA-approved potency range with the original 90–110% range. Results A simulated decrease as small as 10–15% in L-T4 or its absorption generated TSH concentrations outside the bioequivalence target range (0.5–2.5 mU/L TSH), whereas T3 and T4 plasma levels were maintained normal. For a 25% reduction, steady-state TSH changed 300% (from 1.5 to 6 mU/L) compared with <25% for both T4 and T3 (both within their reference ranges). Stability: TSH, T4, and T3 remained within normal ranges for most potency decay scenarios, but tablets of the same dose strength and brand were not bioequivalent between lots and between fresh and near-expired tablets. Conclusions A

  7. Genetic Fusions of Heat-Labile Toxoid (LT) and Heat-Stable Toxin b (STb) of Porcine Enterotoxigenic Escherichia coli Elicit Protective Anti-LT and Anti-STb Antibodies ▿

    PubMed Central

    Zhang, Weiping; Francis, David H.

    2010-01-01

    Enterotoxigenic Escherichia coli (ETEC)-associated diarrhea causes a substantial economic loss to swine producers worldwide. The majority of ETEC strains causing porcine diarrhea, especially postweaning diarrhea (PWD), produce heat-labile toxin (LT) and heat-stable toxin b (STb). LT is commonly used in vaccine development, but STb has not been included because of its poor immunogenicity. As a virulence factor in porcine diarrhea, STb needs to be included as an antigen for development of broad-spectrum vaccines. In this study, we used an LT toxoid (LTR192G [hereafter, LT192]) derived from porcine ETEC to carry a mature STb peptide for LT192-STb fusions to enhance STb immunogenicity for potential vaccine application. Anti-LT and anti-STb antibodies were detected in immunized rabbits and pigs. In addition, when challenged with an STb-positive ETEC strain, all 10 suckling piglets borne by immunized gilts remained healthy, whereas 7 out 9 piglets borne by unimmunized gilts developed moderate diarrhea. This study indicates that the LT192-STb fusion enhanced anti-STb immunogenicity and suggests the LT192-STb fusion antigen can be used in future vaccine development against porcine ETEC diarrhea. PMID:20505006

  8. Galactic fountains and their connection with high and intermediate velocity clouds

    NASA Astrophysics Data System (ADS)

    Spitoni, E.; Recchi, S.; Matteucci, F.

    2008-06-01

    Context: Sequential supernova explosions create supershells which can break out a stratified medium, producing bipolar outflows. The gas of the supershells can fragment into clouds which eventually fall toward the disk producing so-called galactic fountains. Aims: The aim of this paper is to calculate the expansion law and chemical enrichment of a supershell powered by the energetic feedback of a typical Galactic OB association at various galactocentric radii. We study the orbits of the fragments created when the supershell breaks out and we compare their kinetic and chemical properties with the available observations of high - and intermediate - velocity clouds. Methods: We use the Kompaneets (1960, Soviet Phys. Dokl., 5, 46) approximation for the evolution of the superbubble driven by sequential supernova explosions and we compute the abundances of oxygen and iron residing in the thin cold supershell. We assume that supershells are fragmented by Rayleigh-Taylor instabilities and we follow the orbit of the clouds either ballistically or by means of a hybrid model considering viscous interaction between the clouds and the extra-planar gas. Results: Given the self-similarity of the solutions, clouds are always formed ~448 pc above the plane. If the initial metallicity is solar, the pollution from dying stars of the OB association has a negligible effect on the chemical composition of the clouds. The maximum height reached by the clouds above the plane seldom exceeds 2 kpc and when averaging over different throwing angles, the landing coordinate differs from the throwing coordinate by ~1 kpc at most. Conclusions: The range of heights and [O/Fe] ratios spanned by our clouds suggest that the high velocity clouds cannot have a Galactic origin, whereas intermediate velocity clouds have kinematic properties similar to our modeled clouds but have overabundances observed for the [O/Fe] ratios that can be reproduced only with initial metallicities that are too low compared

  9. The structure of basaltic scoria and reticulite and inferences for vesiculation, foam formation, and fragmentation in lava fountains

    NASA Astrophysics Data System (ADS)

    Mangan, Margaret T.; Cashman, Katharine V.

    1996-09-01

    In this investigation pyroclast structures are used to constrain degassing in basaltic lava fountains. Vesicle size, shape, number density, interconnectedness and packing character are quantified and related to (1) the kinetics of bubble nucleation and growth, (2) the structural evolution of magmatic foams and (3) the influence of vesiculation rate on magma fragmentation. Measurements made on a diverse suite of pyroclasts from Kilauea volcano indicate that basaltic foams evolve through an initially disordered, closed-celled, spherical state to a well-ordered, open-celled, polyhedral state as the vesicularity rises from ~ 75 to 98%. The structural changes occur rapidly (< 10 s) in the conduit and fountain in response to an intense vesiculation burst. Vesicle size distribution systematics indicate bubble nucleation rates (~ 2 × 10 4 events cm -3s -1) that are approximately three orders of magnitude greater than those found for effusive eruptive activity. Bubble growth rates (~ 9 × 10 -4 cm/s) exceed effusive estimates by a factor of 3. The observed "runaway" rate of bubble production indicates strong supersaturations at the onset of nucleation. We speculate that the rise speed of the magma, as it reaches the level where significant volatile exsolution begins, determines the intensity of the vesiculation burst, and hence the vigor of the eruption. Rapid expansion and acceleration of the magma under these conditions may provide the impetus for fragmentation.

  10. Dayside observations of thermal-ion upwellings at 800-km altitude - An ionospheric signature of the cleft ion fountain

    NASA Technical Reports Server (NTRS)

    Tsunoda, R. T.; Livingston, R. C.; Vickrey, J. F.; Heelis, R. A.; Hanson, W. B.

    1989-01-01

    There is a growing body of evidence that energetic heavy ions observed at one or more earth radii over the polar cap originate from the dayside ionosphere in the vicinity of the dayside cleft. The ions, consisting mostly of O(+), are often characterized by conic pitch-angle distributions, suggesting that they have undergone acceleration transverse to geomagnetic field lines. This process of ion injection from a latitudinally localized source region in the dayside auroral oval followed by dispersal throughout the entire polar cap has been called the 'cleft ion fountain'. Here, results are presented of upward thermal-ion flows measured at 800-km altitude in the dayside polar ionosphere by the Hilat satellite. The characteristics of these thermal-ion upwellings (TIU) are described and shown to be closely associated with the cleft ion fountain. It is shown that TIU events are latitudinally confined and spatially collocated with cleft electron precipitation, upward field-aligned currents, and velocity gradients in magnetospheric convection.

  11. An efficient algorithm for encoding and decoding of raptor codes over the binary erasure channel

    NASA Astrophysics Data System (ADS)

    Zhang, Ya-Hang; Cheng, Bo-Wen; Zou, Guang-Nan; Wen, Wei-Ping; Qing, Si-Han

    2009-12-01

    As the most advanced rateless fountain codes, Systematic Raptor codes has been adopted by the 3GPP standard as a forward error correction scheme in Multimedia Broadcast/Multicast Services (MBMS). It has been shown to be an efficient channel coding technique which guarantees high symbol diversity in overlay networks. The 3GPP standard outlined a time-efficient maximum-likelihood (ML) decoding scheme that can be implemented using Gaussian elimination. But when the number of encoding symbols grows large, Gaussian elimination need to deal with a large matrix with O (K3) binary arithmetic operations, so the larger K becomes, the worse ML decoding scheme performs. This paper presents a better time-efficient encoding and decoding scheme while maintaining the same symbol recoverable performance, this encoding and decoding scheme is named Rapid Raptor Code. It will be shown that the proposed Rapid Raptor code Scheme significantly improves traditional Raptor codes' efficiency while maintaining the same performance.

  12. Simultaneous oral immunization of mice with live attenuated Escherichia coli expressing LT192-STa 13 and LT 192-STb fusion immunogen, respectively, for polyvalent vaccine candidate.

    PubMed

    Liu, Wenxin; Li, Jinping; Bao, Jun; Li, Xingyue; Guan, Weikun; Yuan, Chaowen; Tang, Jie; Zhao, Zhiteng; Shi, Dongfang

    2015-05-01

    Previous epidemiological study showed that most of the porcine enterotoxin Escherichia coli (ETEC) strains harbor multiple enterotoxins but lack any of the fimbriae or non-fimbrial adhesion genes. Therefore, effective ETEC vaccines need to aim directly at all the enterotoxin antigens. The objective of this study was to evaluate the simultaneous immune effect of two live attenuated E. coli strains expressing LTR192G-STaA13Q and LTR192G-STb fusion immunogen, respectively. The results showed that both local mucosal and systemic immune responses against LT, STa, STb, and F41 were induced in BALB/c mice immunized orally with the recombinant E. coli strains ER-A and ER-B simultaneously. In addition, results of cellular immune responses showed that stimulation index (SI) values of immunized mice were significantly higher than control mice (P < 0.05) and a marked shift toward type-2 helper T lymphocyte (Th 2) immunity. Moreover, the induced antibodies demonstrated neutralizing effects on LT, STa, and STb producing E. coli infection. These data indicated that the use of recombinant E. coli ER-A and ER-B could be a valuable strategy for future polyvalent vaccine development of ETEC. PMID:25549617

  13. Genetic Fusions of Heat-Labile (LT) and Heat-Stable (ST) Toxoids of Porcine Enterotoxigenic Escherichia coli Elicit Neutralizing Anti-LT and Anti-STa antibodies ▿

    PubMed Central

    Zhang, Weiping; Zhang, Chengxian; Francis, David H.; Fang, Ying; Knudsen, David; Nataro, James P.; Robertson, Donald C.

    2010-01-01

    Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of diarrheal disease in humans and farm animals. E. coli fimbriae, or colonization factor antigens (CFAs), and enterotoxins, including heat-labile enterotoxins (LT) and heat-stable enterotoxins (ST), are the key virulence factors in ETEC diarrhea. Unlike fimbriae or LT, STa has not often been included as an antigen in development of vaccines against ETEC diarrhea because of its poor immunogenicity. STa becomes immunogenic only after being coupled with a strongly immunogenic carrier protein. However, native or shorter STa antigens either had to retain toxic activity in order to become antigenic or elicited anti-STa antibodies that were not sufficiently protective. In this study, we genetically mutated the porcine LT (pLT) gene for a pLT192(R→G) toxoid and the porcine STa (pSTa) gene for three full-length pSTa toxoids [STa11(N→K), STa12(P→F), and STa13(A→Q)] and used the full-length pLT192 as an adjuvant to carry the pSTa toxoid for pLT192:pSTa-toxoid fusion antigens. Rabbits immunized with pLT192:pSTa12 or pLT192:pSTa13 fusion protein developed high titers of anti-LT and anti-STa antibodies. Furthermore, rabbit antiserum and antifecal antibodies were able to neutralize purified cholera toxin (CT) and STa toxin. In addition, preliminary data suggested that suckling piglets born by a sow immunized with the pLT192:pSTa13 fusion antigen were protected when challenged with an STa-positive ETEC strain. This study demonstrated that pSTa toxoids are antigenic when fused with a pLT toxoid and that the elicited anti-LT and anti-STa antibodies were protective. This fusion strategy could provide instructive information to develop effective toxoid vaccines against ETEC-associated diarrhea in animals and humans. PMID:19858307

  14. Prevention of Ocular Scarring After Glaucoma Filtering Surgery Using the Monoclonal Antibody LT1009 (Sonepcizumab) in a Rabbit Model

    PubMed Central

    Lukowski, Zachary L.; Min, Jeff; Beattie, Ashley R.; Meyers, Craig A.; Levine, Monica A.; Stoller, Glenn; Schultz, Gregory S.; Samuelson, Don A.; Sherwood, Mark B.

    2013-01-01

    Purpose Excessive scarring leading to failure of the filtering bleb continues to be a major problem after glaucoma filtration surgery. This study examines the antifibrotic effects of the anti-S1P monoclonal antibody LT1009 (Sonepcizumab) in prolonging bleb survival in a rabbit model of glaucoma filtering surgery. Methods The frequency of LT1009 dosage was determined initially using an enzyme-linked immunosorbent assay assay measuring LT1009 eye tissue retention in 6 New Zealand White rabbits. A further 21 New Zealand White rabbits underwent glaucoma filtering surgery. Bleb tissues were observed and compared clinically and histologically. The duration of bleb elevation was compared among LT1009, balanced saline solution (BSS) negative control, and mitomycin-C (MMC)-positive control. Results The mean duration of bleb survival was 28.5 ± 8.5 days for rabbits receiving injections of LT1009, 21.0 ± 5.6 days for those receiving injections of BSS, and 33.8 ± 5.6 days for rabbits receiving MMC. Analysis of variance with post hoc testing suggests a statistically significant trend of improvement in bleb duration for LT1009 when compared with BSS controls. Non-painful, upper eyelid edema was noted after 5 injections of LT1009, which resolved over a 10-day period. MMC eyes developed avascular conjunctivas with areas of thinning and sparse cellularity, whereas the conjunctiva of LT1009 and BSS eyes remained relatively normal. Conclusions The monoclonal antibody LT1009 demonstrated a longer duration of bleb elevation than BSS control without adverse conjunctival effects associated with MMC. However, after multiple doses LT1009 use was associated with short-term upper eyelid edema. PMID:21946553

  15. Arsenic Removal from Drinking Water by Iron Removal - U.S. EPA Demonstration Project at Northeastern Elementary School in Fountain City, IN - Final Performance Evaluation Report

    EPA Science Inventory

    This report documents the activities performed and the results obtained from the arsenic removal treatment technology demonstration project at Northeastern Elementary School in Fountain City, IN. The main objective of the project was to evaluate the effectiveness of US Water Sys...

  16. Long term therapy with a new liquid L-thyroxine preparation: bioequivalence with L-T4 tablets.

    PubMed

    Carpi, A; Toni, M G; Maccheroni, M; De Gaudio, C

    1992-12-01

    Seventy-four euthyroid patients with nodular goiter (55) or primary hypothyroidism (19) were selected for long term treatment with a new preparation containing L-T4 in solution (Tiroxen, Laboratori Baldacci, Pisa, Italy). Each patient underwent, before or after receiving the L-T4 in solution, long term treatment with L-T4 in tablet form at the same dose. The serum concentrations of TSH, TT4, TT3, FT4 and FT3 were measured basally and during therapy with each of the two L-T4 preparations (liquid and tablet). In the golter group, mean serum TSH concentration was 1.4 microUI/ml basally, while it was 0.47 microUI/ml following both L-T4 tablet therapy and L-T4 solution administration. Mean basal TSH value was significantly different from the two values on the therapy (p < 0.001 in each instance). Mean basal serum TT4 concentration was 8.2 +/- 0.25 microgram/dl basally while it was 9.9 +/- 0.28 microgram/dl (p < 0.001) on L-T4 tablet therapy and 9.7 +/- 0.26 (p < 0.001) on L-T4 solution administration. Mean basal serum concentration of TT3, FT4, FT3 was not significantly different from the value on the therapy, either with L-T4 tablet or with L-T4 solution. In the hypothyroid patients the high mean basal serum TSH concentration (23.6 microUI/ml) returned to normal similar values on L-T4 tablet therapy (0.96 microUI/ml; p < 0.01) and on L-T4 solution administration (1.24 microUI/ml; p < 0.01). The serum TSH concentration value during L-T4 therapy varied from unmeasurable level to 3.5 microUI/ml during the tablet administration and to 4.8 microUI/ml during the solution administration.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1285037

  17. A new intense lava fountain episode at Voragine crater (Mt. Etna): the event of 3 December 2015

    NASA Astrophysics Data System (ADS)

    Andronico, Daniele; Bonadonna, Costanza; Cioni, Raffaello; Cristaldi, Antonio; Pascual, Aurélie Joy; Russo, Alessandro; Scollo, Simona

    2016-04-01

    On 3 December 2015 Voragine crater, one of the five summit craters of Mt. Etna (Italy), produced a powerful lava fountain. The last paroxysmal episodes from this crater had occurred on July 1998 and September 1999; both events had been very intense, the first one classified as subPlinian and the latter causing significant disruption to road traffic due dense tephra sedimentation. Afterward, the Voragine entered in a period of relative quiescence interrupted by short events of Strombolian activity and weak ash emissions. In August 2015 the crater resumed its activity with discontinuous ash puffs that were followed by periods of relatively intense ash blasts in September. In October, this activity was clearly replaced by weak, pulsating Strombolian explosions confined inside the crater, which was several tens of meter deep. Gradually the Strombolian blasts became more continuous and intense and lapilli started to sediment around the crater rim. In the night between 2 and 3 December, the increase of seismic tremor coevally to the Strombolian activity heralded the lava fountain episode. During the paroxysm, that lasted around 40 minutes, vigorous magma jets were also produced by the adjacent Bocca Nuova summit crater, contributing to form a unique eruption column up to at least 7-8 km above the volcano and dispersed to the NE. Lighting was recurrently observed inside the column. Field survey, carried out between 3 and 5 December from a distance of 5 km from the vent, allowed to map the fallout dispersal and collect tephra samples. Estimation of uncertainty associated with ash sampling were also performed. Due to low-intense winds, the fallout mostly affected the area close to the volcanic slopes, but it also reached both the Tyrrhenian Sea to the N and the Ionian Sea to the E, more than 100 km of distance from the crater. Measurements of shape and density on the largest clasts collected within the first km from the Voragine were performed. Furthermore, we measured the

  18. Upward Bound: An Untapped Fountain Of Youth Wanting To Learn About Math And Science

    NASA Astrophysics Data System (ADS)

    Gillis-Davis, J. J.; Sherman, S. B.; Gillis-Davis, L. C.; Svelling, K. L.

    2009-12-01

    , physics, math, and engineering. In addition, learning science through inquiry and experimentation lends tangible examples to abstract principles. Our curricula (available on-line for sharing) are comprised of (1) modular classroom lesson plans, (2) teacher tutorials, and (3) hands-on laboratory experiments. Each set of summer classes has a theme; the first set of summer classes centered on factors that affect climate on any planet. For example, students measured solar activity by counting sunspots and learned about the greenhouse effect by conducting experiments with colored bottles. The second summer focused on how the electromagnetic spectrum is fundamental to remote sensing. During our summer 2009 program the Lunar Reconnaissance Orbiter launched, and with its many instruments served as a shining example of how the electromagnetic spectrum is used to study planetary bodies. Thus, NASA archived and student-collected data sets used in a PBL setting provide the basic foundation for helping students learn science and math concepts, while the UB programs ensure sustainability by providing a fountain of youth who want to learn.

  19. A laser-cooled cesium fountain frequency standard and a measurement of the frequency shift due to ultra-cold collisions

    NASA Technical Reports Server (NTRS)

    Gibble, Kurt; Kasapi, Steven; Chu, Steven

    1993-01-01

    A frequency standard based on an atomic fountain of cesium atoms may have an accuracy of 10(exp -16) due to longer interaction times and smaller anticipated systematic errors. All of the known systematic effects that now limit the accuracy of the Cs frequency standard increase either linearly or as some higher power of the atom's velocity. The one systematic frequency shift which is dramatically different is the frequency shift due to the collisions between the laser cooled atoms. At a temperature of a few micro-K, the de Broglie wavelength (lambda(sub deB) = h/p, where h is Planck's constant and p is the momentum of the atom) is much larger than the scale of the interatomic potential. Under these conditions the collision cross sections can be as large as (lambda(sub deB)(sup 2))/Pi and the frequency shift due to these collisions was recently calculated. In our Cs atomic fountain, we laser cooled and trapped 10(exp 10) Cs atoms in 0.4 s. By shifting the frequencies of the laser beams, the atoms were launched upwards at 2.5 m/s and a fraction of the atoms were optically pumped into the F=3 ground state. The unwanted atoms in the F=4 ground state were removed from the fountain with radiation pressure from a laser beam tuned to excite only those atoms. The Cs atoms in the F=3 state traveled ballistically upwards, were excited by the microwave cavity, and then returned back through the same cavity in the atomic fountain configuration. By varying the cold atom density, a density dependent shift of -12.9 +/- 0.7 mHz or -1.4 x 10-12 for an average fountain density of (2.7 +/- 1.5) 10(exp 9) atoms/cm(sup 3) was measured.

  20. Measurement of the blackbody radiation shift of the {sup 133}Cs hyperfine transition in an atomic fountain

    SciTech Connect

    Levi, Filippo; Calonico, Davide; Lorini, Luca; Micalizio, Salvatore; Godone, Aldo

    2004-09-01

    We used a Cs fountain to measure the Stark shift of the ground-state hyperfine transition frequency in cesium (9.2 GHz) due to the electric field of the blackbody radiation. The relative shift at 300 K deduced from our measurements, including the leading and the second-order term in temperature, is (-1.45{+-}0.09)x10{sup -14} and agrees with our recent theoretical evaluation (-1.51{+-}0.07)x10{sup -14} [Micalizio et al. Phys. Rev. A 69, 053401 (2004)]. These values differ from that currently used (-1.735{+-}0.003)x10{sup -14}, with significant implications on frequency standards accuracy, on clocks comparison and on a variety of high-precision physics tests, such as the time stability of fundamental constants.

  1. Artificial-recharge tests in Upper Black Squirrel Creek basin, Jimmy Camp Valley, and Fountain Valley, El Paso County, Colorado

    USGS Publications Warehouse

    Emmons, P.J.

    1977-01-01

    Artificial-recharge tests were conducted in the alluvium in upper Black Squirrel Creek basin, the alluvium in Jimmy Camp Valley, and in the alluvium overlying the Widefield aquifer which is located in an ancestral channel in Fountain Valley, Colo. Nine artificial-recharge pits with areas of approximately 9,200 square feet each were excavated in the unsaturated zones above the three aquifers. Each artificial-recharge site was instrumented to measure inflow, stage fluctuations, and water-table fluctuations. Artificial-recharge tests of approximately 10 days ' duration were conducted at each of the nine artificial-recharge sites and one extended test of approximately 30 days ' duration was conducted in each of the three study areas. Periphyton growth, present in most of the artificial-recharge ponds, was insufficient to cause noticeable decline in the rate of infiltration. (Woodard-USGS)

  2. Decadal evolution of a degassing magma reservoir unravelled from fire fountains produced at Etna volcano (Italy) between 1989 and 2001

    NASA Astrophysics Data System (ADS)

    Vergniolle, Sylvie; Gaudemer, Yves

    2012-04-01

    Between 1989 and 2001, five eruptions at Etna displayed a regular alternation between repose periods and episodes rich in gas, termed quasi-fire fountains and consisting of a series of Strombolian explosions sometimes leading to a fire fountain. This behaviour results from the coalescence of a foam layer trapped at the top of the reservoir which was periodically rebuilt prior to each episode (Vergniolle and Jaupart, J Geophys Res 95:2793-2809, 1990). Visual observations of fire fountains are combined with the foam dynamics to estimate the five degassing parameters characteristic of the degassing reservoir, i.e. the number of bubbles, gas volume fraction, bubble diameter, reservoir thickness and reservoir volume. The study of decadal cycles of eruptive patterns (Allard et al., Earth Sci Rev 78:85-114, 2006) suggests that the first eruption with fire fountains occurred in 1995 while the last one happened in 2001. The number of bubbles and the gas volume fraction increase smoothly from the beginning of the cycle (1995) to its end (2001). The increasing number of bubbles per cubic metre, from 0.61-20×105 to 0.1-3.4×109, results from cooling of the magma within the reservoir. The simultaneously decreasing bubble diameter, from 0.67-0.43 to 0.30-0.19 mm, is related to the decreasing amount of dissolved volatiles. Meanwhile, the thickness and the volume of the degassing reservoir diminish, from values typical of the magma reservoir to values characteristic of a very thin bubbly layer, marking the quasi-exhaustion of volatiles. The magma reservoir has a slender vertical shape, with a maximum thickness of 3,300-8,200 m and a radius of 240 m (Vergniolle 2008), making its detection from seismic studies difficult. Its volume, at most 0.58-1.4 km3, is in agreement with geochemical studies (0.5 km3) (Le Cloarec and Pennisi, J Volcanol Geotherm Res 108:141-155, 2001). The time evolution of both the total gas volume expelled per eruption, and the inter-eruptive gas flux results

  3. Low intensity hawaiian fountaining as exemplified by the March 2011, Kamoamoa eruption at Kilauea Volcano, Hawai`i (Invited)

    NASA Astrophysics Data System (ADS)

    Orr, T. R.; Houghton, B. F.; Poland, M. P.; Patrick, M. R.; Thelen, W. A.; Sutton, A. J.; Parcheta, C. E.; Thornber, C. R.

    2013-12-01

    The latest 'classic' hawaiian high-fountaining activity at Kilauea Volcano occurred in 1983-1986 with construction of the Pu`u `O`o pyroclastic cone. Since then, eruptions at Kilauea have been dominated by nearly continuous effusive activity. Episodes of sustained low hawaiian fountaining have occurred but are rare and restricted to short-lived fissure eruptions along Kilauea's east rift zone. The most recent of these weakly explosive fissure eruptions--the Kamoamoa eruption--occurred 5-9 March 2011. The Kamoamoa eruption was probably the consequence of a decrease in the carrying capacity of the conduit feeding the episode 58 eruptive vent down-rift from Pu`u `O`o in Kilauea's east rift zone. As output from the vent waned, Kilauea's summit magma storage and east rift zone transport system began to pressurize, as manifested by an increase in seismicity along the upper east rift zone, inflation of the summit and Pu`u `O`o, expansion of the east rift zone, and rising lava levels at both the summit and Pu`u `O`o. A dike began propagating towards the surface from beneath Makaopuhi Crater, 6 km west of Pu`u `O`o, at 1342 Hawaiian Standard Time (UTC - 10 hours) on 5 March. A fissure eruption started about 3.5 hours later near Nāpau Crater, 2 km uprift of Pu`u `O`o. Activity initially jumped between numerous en echelon fissure segments before centering on discrete vents near both ends of the 2.4-km-long fissure system for the final two days of the eruption. About 2.6 mcm of lava was erupted over the course of four days with a peak eruption rate of 11 m3/s. The petrologic characteristics of the fissure-fed lava indicate mixing between hotter mantle-derived magma and cooler rift-stored magma, with a greater proportion of the cooler component than was present in east rift zone lava erupting before March 2011. The fissure eruption was accompanied by the highest SO2 emission rates since 1986. Coincidentally, the summit and Pu`u `O`o deflated as magma drained away, causing

  4. CysLT1 Receptor Is Protective against Oxidative Stress in a Model of Irritant-Induced Asthma.

    PubMed

    McGovern, Toby; Goldberger, Madison; Chen, Michael; Allard, Benoit; Hamamoto, Yoichiro; Kanaoka, Yoshihide; Austen, K Frank; Powell, William S; Martin, James G

    2016-07-01

    The bronchoconstrictive and proinflammatory properties of cysteinyl leukotrienes (cysLTs) in allergic asthma mediate their effects predominantly through the cysLT1 receptor (cysLT1R). However, the role of cysLTs and cysLT1R in innate immune-triggered asthma is largely unexplored. We explored the synthesis of cysLTs and cysLT1R as determinants of airway responses in an oxidative stress-induced model of irritant asthma. Wild-type (WT) mice exposed to 100 ppm Cl2 for 5 min had airway neutrophilia, increased cysLT production, and pulmonary expression of cysLT-related biosynthetic genes. CysLT1R-deficient (CysLTr1(-/-)) mice that were exposed to Cl2 demonstrated airway hyperresponsiveness to inhaled methacholine significantly greater than in WT BALB/c mice. Compared to WT mice, airway neutrophilia and keratinocyte chemoattractant production levels were higher in CysLTr1(-/-) mice and airway hyperresponsiveness was ameliorated using a granulocyte depletion Ab. CysLTr1(-/-) mice also demonstrated prolonged bronchial epithelial cell apoptosis following Cl2 WT mice showed increased antioxidant and NF erythroid 2-related factor 2 (Nrf2) gene expression, Nrf2 nuclear translocation in bronchial epithelial cells, and increased reduced glutathione/oxidized glutathione following Cl2 exposure whereas CysLTr1(-/-) mice did not. Furthermore, CysLTr1(-/-) mice demonstrated increased pulmonary E-cadherin expression and soluble E-cadherin shedding compared with WT mice. Loss of a functional cysLT1R results in aberrant antioxidant response and increased susceptibility to oxidative injury, apparently via a cysLT1R-dependent impairment of Nrf2 function. PMID:27226094

  5. Repeated detection of microbes in beverages dispensed from soda fountain machines and the effect of flushing on microbial density.

    PubMed

    Godard, Renee D; Sharma, Puja; Wagner, Carlie Jo; Wilson, C Morgan; Fleming-Haddock, Amie; Beach, Rebecca L

    2013-05-15

    Few studies have examined patterns of microbial contamination in soda fountain beverages. In this study, patterns of microbial contamination in beverages dispensed from soda fountain machines (SFMs) sampled in June 2009 and then again 13 months later were compared. Over 70% of beverages contained microbes in both years, suggesting that contamination of beverages dispensed from SFMs can continue for long periods of time. In addition, the impact of disinfecting the dispensing nozzles and plastic tubing of SFMs, as well as the impact of machine use on microbial contamination was assessed. Managers from 26 establishments (fast-food and convenience stores) were interviewed about their SFM disinfecting practices and no correlation was found between the self-reported disinfecting practices and levels of microbial contamination in beverages dispensed from SFMs. Furthermore, in a direct study of two SFMs with an established disinfecting regimen, CFU/mL in beverages increased significantly immediately after disinfecting of plastic tubing yet returned to pre-disinfecting concentrations within 11 days. These results suggest that disinfecting may disturb microbial communities, resulting in increased planktonic microbes, but not the ultimate removal of communities themselves. Additionally, samples of a sugar and a diet soda were collected from 15 different SFMs before and after dispensing of ~0.95 L (the approximate size of a large beverage cup). Samples collected before dispensing this volume had significantly higher microbial counts than those collected after, suggesting that planktonic microbes in the beverage lines had been reduced by flushing. As there are currently no regulations regarding the disinfecting of SFM tubing or periodic inspections of beverages dispensed from SFMs, it would be valuable for consumers to encourage increased surveillance of SFMs, and to dispense some beverage before filling their cups. PMID:23562835

  6. A tripartite fusion, FaeG-FedF-LT(192)A2:B, of enterotoxigenic Escherichia coli (ETEC) elicits antibodies that neutralize cholera toxin, inhibit adherence of K88 (F4) and F18 fimbriae, and protect pigs against K88ac/heat-labile toxin infection.

    PubMed

    Ruan, Xiaosai; Liu, Mei; Casey, Thomas A; Zhang, Weiping

    2011-10-01

    Enterotoxigenic Escherichia coli (ETEC) strains expressing K88 (F4) or F18 fimbriae and heat-labile (LT) and/or heat-stable (ST) toxins are the major cause of diarrhea in young pigs. Effective vaccines inducing antiadhesin (anti-K88 and anti-F18) and antitoxin (anti-LT and anti-ST) immunity would provide broad protection to young pigs against ETEC. In this study, we genetically fused nucleotides coding for peptides from K88ac major subunit FaeG, F18 minor subunit FedF, and LT toxoid (LT(192)) A2 and B subunits for a tripartite adhesin-adhesin-toxoid fusion (FaeG-FedF-LT(192)A2:B). This fusion was used for immunizations in mice and pigs to assess the induction of antiadhesin and antitoxin antibodies. In addition, protection by the elicited antiadhesin and antitoxin antibodies against a porcine ETEC strain was evaluated in a gnotobiotic piglet challenge model. The data showed that this FaeG-FedF-LT(192)A2:B fusion elicited anti-K88, anti-F18, and anti-LT antibodies in immunized mice and pigs. In addition, the anti-porcine antibodies elicited neutralized cholera toxin and inhibited adherence against both K88 and F18 fimbriae. Moreover, immunized piglets were protected when challenged with ETEC strain 30302 (K88ac/LT/STb) and did not develop clinical disease. In contrast, all control nonvaccinated piglets developed severe diarrhea and dehydration after being challenged with the same ETEC strain. This study clearly demonstrated that this FaeG-FedF-LT(192)A2:B fusion antigen elicited antibodies that neutralized LT toxin and inhibited the adherence of K88 and F18 fimbrial E. coli strains and that this fusion could serve as an antigen for vaccines against porcine ETEC diarrhea. In addition, the adhesin-toxoid fusion approach used in this study may provide important information for developing effective vaccines against human ETEC diarrhea. PMID:21813665

  7. Characterization of a mutant Escherichia coli heat-labile toxin, LT(R192G/L211A), as a safe and effective oral adjuvant.

    PubMed

    Norton, Elizabeth B; Lawson, Louise B; Freytag, Lucy C; Clements, John D

    2011-04-01

    Despite the fact that the adjuvant properties of the heat-labile enterotoxins of Escherichia coli (LT) and Vibrio cholerae (CT) have been known for more than 20 years, there are no available oral vaccines containing these molecules as adjuvants, primarily because they are both very potent enterotoxins. A number of attempts with various degrees of success have been made to reduce or eliminate the enterotoxicity of LT and CT so they can safely be used as oral adjuvants or immunogens. In this report we characterize the structural, enzymatic, enterotoxic, and adjuvant properties of a novel mutant of LT, designated LT(R192G/L211A), or dmLT. dmLT was not sensitive to trypsin activation, had reduced enzymatic activity for induction of cyclic AMP in Caco-2 cells, and exhibited no enterotoxicity in the patent mouse assay. Importantly, dmLT retained the ability to function as an oral adjuvant for a coadministered antigen (tetanus toxoid) and to elicit anti-LT antibodies. In vitro and in vivo data suggest that the reduced enterotoxicity of this molecule compared to native LT or the single mutant, LT(R192G), is a consequence of increased sensitivity to proteolysis and rapid intracellular degradation in mammalian cells. In conclusion, dmLT is a safe and powerful detoxified enterotoxin with the potential to function as a mucosal adjuvant for coadministered antigens and to elicit anti-LT antibodies without undesirable side effects. PMID:21288994

  8. Characterization of a Mutant Escherichia coli Heat-Labile Toxin, LT(R192G/L211A), as a Safe and Effective Oral Adjuvant ▿

    PubMed Central

    Norton, Elizabeth B.; Lawson, Louise B.; Freytag, Lucy C.; Clements, John D.

    2011-01-01

    Despite the fact that the adjuvant properties of the heat-labile enterotoxins of Escherichia coli (LT) and Vibrio cholerae (CT) have been known for more than 20 years, there are no available oral vaccines containing these molecules as adjuvants, primarily because they are both very potent enterotoxins. A number of attempts with various degrees of success have been made to reduce or eliminate the enterotoxicity of LT and CT so they can safely be used as oral adjuvants or immunogens. In this report we characterize the structural, enzymatic, enterotoxic, and adjuvant properties of a novel mutant of LT, designated LT(R192G/L211A), or dmLT. dmLT was not sensitive to trypsin activation, had reduced enzymatic activity for induction of cyclic AMP in Caco-2 cells, and exhibited no enterotoxicity in the patent mouse assay. Importantly, dmLT retained the ability to function as an oral adjuvant for a coadministered antigen (tetanus toxoid) and to elicit anti-LT antibodies. In vitro and in vivo data suggest that the reduced enterotoxicity of this molecule compared to native LT or the single mutant, LT(R192G), is a consequence of increased sensitivity to proteolysis and rapid intracellular degradation in mammalian cells. In conclusion, dmLT is a safe and powerful detoxified enterotoxin with the potential to function as a mucosal adjuvant for coadministered antigens and to elicit anti-LT antibodies without undesirable side effects. PMID:21288994

  9. Speech coding

    NASA Astrophysics Data System (ADS)

    Gersho, Allen

    1990-05-01

    Recent advances in algorithms and techniques for speech coding now permit high quality voice reproduction at remarkably low bit rates. The advent of powerful single-ship signal processors has made it cost effective to implement these new and sophisticated speech coding algorithms for many important applications in voice communication and storage. Some of the main ideas underlying the algorithms of major interest today are reviewed. The concept of removing redundancy by linear prediction is reviewed, first in the context of predictive quantization or DPCM. Then linear predictive coding, adaptive predictive coding, and vector quantization are discussed. The concepts of excitation coding via analysis-by-synthesis, vector sum excitation codebooks, and adaptive postfiltering are explained. The main idea of vector excitation coding (VXC) or code excited linear prediction (CELP) are presented. Finally low-delay VXC coding and phonetic segmentation for VXC are described.

  10. Survey of A{sub LT'} asymmetries in semi-exclusive electron scattering on He4 and C12

    SciTech Connect

    Dan Protopopescu; et. Al.

    2005-02-21

    Single spin azimuthal asymmetries A{sub LT'} were measured at Jefferson Lab using 2.2 and 4.4 GeV longitudinally polarized electrons incident on {sup 4}He and {sup 12}C targets in the CLAS detector. A{sub LT'} is related to the imaginary part of the longitudinal-transverse interference and in quasifree nucleon knockout it provides an unambiguous signature for final state interactions (FSI). Experimental values of A{sub LT'} were found to be below 5%, typically |A{sub LT'}| < 3% for data with good statistical precision. Optical Model in Eikonal Approximation (OMEA) and Relativistic Multiple-Scattering Glauber Approximation (RMSGA) calculations are shown to be consistent with the measured asymmetries.

  11. Uplink Coding

    NASA Technical Reports Server (NTRS)

    Pollara, Fabrizio; Hamkins, Jon; Dolinar, Sam; Andrews, Ken; Divsalar, Dariush

    2006-01-01

    This viewgraph presentation reviews uplink coding. The purpose and goals of the briefing are (1) Show a plan for using uplink coding and describe benefits (2) Define possible solutions and their applicability to different types of uplink, including emergency uplink (3) Concur with our conclusions so we can embark on a plan to use proposed uplink system (4) Identify the need for the development of appropriate technology and infusion in the DSN (5) Gain advocacy to implement uplink coding in flight projects Action Item EMB04-1-14 -- Show a plan for using uplink coding, including showing where it is useful or not (include discussion of emergency uplink coding).

  12. Evaluating the A-Subunit of the Heat-Labile Toxin (LT) As an Immunogen and a Protective Antigen Against Enterotoxigenic Escherichia coli (ETEC)

    PubMed Central

    Norton, Elizabeth B.; Branco, Luis M.; Clements, John D.

    2015-01-01

    Diarrheal illness contributes to malnutrition, stunted growth, impaired cognitive development, and high morbidity rates in children worldwide. Enterotoxigenic Escherichia coli (ETEC) is a major contributor to this diarrheal disease burden. ETEC cause disease in the small intestine by means of colonization factors and by production of a heat-labile enterotoxin (LT) and/or a small non-immunogenic heat-stable enterotoxin (ST). Overall, the majority of ETEC produce both ST and LT. LT induces secretion via an enzymatically active A-subunit (LT-A) and a pentameric, cell-binding B-subunit (LT-B). The importance of anti-LT antibodies has been demonstrated in multiple clinical and epidemiological studies, and a number of potential ETEC vaccine candidates have included LT-B as an important immunogen. However, there is limited information about the potential contribution of LT-A to development of protective immunity. In the current study, we evaluate the immune response against the A-subunit of LT as well as the A-subunit’s potential as a protective antigen when administered alone or in combination with the B-subunit of LT. We evaluated human sera from individuals challenged with a prototypic wild-type ETEC strain as well as sera from individuals living in an ETEC endemic area for the presence of anti-LT, anti-LT-A and anti-LT-B antibodies. In both cases, a significant number of individuals intentionally or endemically infected with ETEC developed antibodies against both LT subunits. In addition, animals immunized with the recombinant proteins developed robust antibody responses that were able to neutralize the enterotoxic and cytotoxic effects of native LT by blocking binding and entry into cells (anti-LT-B) or the intracellular enzymatic activity of the toxin (anti-LT-A). Moreover, antibodies to both LT subunits acted synergistically to neutralize the holotoxin when combined. Taken together, these data support the inclusion of both LT-A and LT-B in prospective vaccines

  13. Type II heat-labile enterotoxins from 50 diverse Escherichia coli isolates belong almost exclusively to the LT-IIc family and may be prophage encoded.

    PubMed

    Jobling, Michael G; Holmes, Randall K

    2012-01-01

    Some enterotoxigenic Escherichia coli (ETEC) produce a type II heat-labile enterotoxin (LT-II) that activates adenylate cyclase in susceptible cells but is not neutralized by antisera against cholera toxin or type I heat-labile enterotoxin (LT-I). LT-I variants encoded by plasmids in ETEC from humans and pigs have amino acid sequences that are ≥ 95% identical. In contrast, LT-II toxins are chromosomally encoded and are much more diverse. Early studies characterized LT-IIa and LT-IIb variants, but a novel LT-IIc was reported recently. Here we characterized the LT-II encoding loci from 48 additional ETEC isolates. Two encoded LT-IIa, none encoded LT-IIb, and 46 encoded highly related variants of LT-IIc. Phylogenetic analysis indicated that the predicted LT-IIc toxins encoded by these loci could be assigned to 6 subgroups. The loci corresponding to individual toxins within each subgroup had DNA sequences that were more than 99% identical. The LT-IIc subgroups appear to have arisen by multiple recombinational events between progenitor loci encoding LT-IIc1- and LT-IIc3-like variants. All loci from representative isolates encoding the LT-IIa, LT-IIb, and each subgroup of LT-IIc enterotoxins are preceded by highly-related genes that are between 80 and 93% identical to predicted phage lysozyme genes. DNA sequences immediately following the B genes differ considerably between toxin subgroups, but all are most closely related to genomic sequences found in predicted prophages. Together these data suggest that the LT-II loci are inserted into lambdoid type prophages that may or may not be infectious. These findings raise the possibility that production of LT-II enterotoxins by ETEC may be determined by phage conversion and may be activated by induction of prophage, in a manner similar to control of production of Shiga-like toxins by converting phages in isolates of enterohemmorhagic E. coli. PMID:22242186

  14. Evaluating the A-Subunit of the Heat-Labile Toxin (LT) As an Immunogen and a Protective Antigen Against Enterotoxigenic Escherichia coli (ETEC).

    PubMed

    Norton, Elizabeth B; Branco, Luis M; Clements, John D

    2015-01-01

    Diarrheal illness contributes to malnutrition, stunted growth, impaired cognitive development, and high morbidity rates in children worldwide. Enterotoxigenic Escherichia coli (ETEC) is a major contributor to this diarrheal disease burden. ETEC cause disease in the small intestine by means of colonization factors and by production of a heat-labile enterotoxin (LT) and/or a small non-immunogenic heat-stable enterotoxin (ST). Overall, the majority of ETEC produce both ST and LT. LT induces secretion via an enzymatically active A-subunit (LT-A) and a pentameric, cell-binding B-subunit (LT-B). The importance of anti-LT antibodies has been demonstrated in multiple clinical and epidemiological studies, and a number of potential ETEC vaccine candidates have included LT-B as an important immunogen. However, there is limited information about the potential contribution of LT-A to development of protective immunity. In the current study, we evaluate the immune response against the A-subunit of LT as well as the A-subunit's potential as a protective antigen when administered alone or in combination with the B-subunit of LT. We evaluated human sera from individuals challenged with a prototypic wild-type ETEC strain as well as sera from individuals living in an ETEC endemic area for the presence of anti-LT, anti-LT-A and anti-LT-B antibodies. In both cases, a significant number of individuals intentionally or endemically infected with ETEC developed antibodies against both LT subunits. In addition, animals immunized with the recombinant proteins developed robust antibody responses that were able to neutralize the enterotoxic and cytotoxic effects of native LT by blocking binding and entry into cells (anti-LT-B) or the intracellular enzymatic activity of the toxin (anti-LT-A). Moreover, antibodies to both LT subunits acted synergistically to neutralize the holotoxin when combined. Taken together, these data support the inclusion of both LT-A and LT-B in prospective vaccines

  15. Silver Linings: Using Cloud Maps to Understand the L/T Spectral Transtion

    NASA Astrophysics Data System (ADS)

    Radigan, Jacqueline

    2013-10-01

    Recent observations in the time domain have revealed large amplitude variability for a subset of objects at the transition between cloudy L and clear T spectral types, indicative of patchy cloud coverage. We propose to obtain time-resolved near-infrared spectra of two highly variable L/T transition brown dwarfs and an unusually blue L dwarf in order to make spectrally and spatially resolved maps of their surfaces. By decomposing the spectral time series into principal components we can determine the number of different surface spectra that contribute to the variability and test whether the current paradigm--namely that variability for these objects results due to holes in the cloud layer--is accurate. Our previous Cycle 18 observations {GO12314, PI:Apai} of two early T-dwarfs suggest a simple two-surface scenario where variability across a wide range of atmospheric pressures is correlated, and presumably governed by the horizontal distribution of condensates {Apai, Radigan & Buenzli et al., submitted}, while the behavior of a T6.5 dwarf was observed to be significantly more complex {Buenzli et al. 2012}. While these data are suggestive, a pattern cannot be inferred from observations of only two objects. The proposed observations will double the sample of variable L/T transition objects mapped with WFC3 grism spectroscopy from 2 to 4, and allow us to establish a pattern; namely, do all L/T transition objects share similar spectral variations, indicative of a common mechanism and number of surface components? We will then investigate whether this pattern extends to unusually blue L-dwarfs, also hypothesized to have patchy clouds.

  16. [Rhizopus microsporus strain UzLT-I--a thermotolerant producer of lipase].

    PubMed

    Zakirov, M Z; Sultanova, I G; Davranov, K

    1975-01-01

    The properties of the thermotolerant fungus Rhizopus microsporus strain UzLT-1--producer of lipolyptic enzymes are described. Optimal cultivation conditions--40 degrees, C, pH 4.5--Are determined. The lipolytic activity of the culture on the medium consisting of corn extract (2%), cotton-seed oil (1%) and water is 850 ml 0.1 n KOH per 100 ml culture liquid. The enzymic preparations of lipase have been precipitated by isopropanol and ammonium sulphate. The preparation precipitated by isopropanol shows its macimum activity at pH 4.2 and 7.8 and a temperature of 40--50 degrees C. PMID:1738

  17. Field measurements and interpretation of TMI-2 instrumentation: CF-2-LT2

    SciTech Connect

    Jones, J E; Smith, J T; Mathis, M V

    1982-01-01

    This report describes the measurements and results of the Core Flood Tank 1A level monitor CF-2-LT2. This instrument consists of a Bailey Type BY Process Computer Transmitter connected to a readout module by approximately 500 feet of cable through a penetration junction and an instrument mounting junction. The status of this instrument is uncertain, but it was producing a reasonable output reading which implied it had not failed. As a result, measurements on this instrument were designed to determine if it were properly functioning.

  18. Lava fountain heights at Pu'u 'O'o, Kilauea, Hawaii - Indicators of amount and variations of exsolved magma volatiles

    NASA Technical Reports Server (NTRS)

    Head, James W., III; Wilson, Lionel

    1987-01-01

    Factors most important in determining fountain height in Hawaiian-type basaltic eruptions were assessed on the basis of theoretical calculations and observations at Pu'u 'O'o vent, east rift zone of Kilauea, Hawaii. It is shown that fountain height is very sensitive to changes in exsolved gas content (and, thus, can be used to estimate variability in exsolved gas content) and relatively insensitive to large variations in volume flux. Volume flux was found to be the most important parameter determining the equilibrium vent diameter. The results of calculations also indicate that there was a general increase in magma gas content over the first 20 episodes of the Pu'u 'O'o eruption and that gas depletion took place in the conduit beneath the vent during repose periods.

  19. Description and User Manual for a Web-Based Interface to a Transit-Loss Accounting Program for Monument and Fountain Creeks, El Paso and Pueblo Counties, Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Krammes, Gary S.; Beal, Vivian J.

    2007-01-01

    The U.S. Geological Survey, in cooperation with Colorado Springs Utilities, the Colorado Water Conservation Board, and the El Paso County Water Authority, began a study in 2004 with the following objectives: (1) Apply a stream-aquifer model to Monument Creek, (2) use the results of the modeling to develop a transit-loss accounting program for Monument Creek, (3) revise an existing accounting program for Fountain Creek to easily incorporate ongoing and future changes in management of return flows of reusable water, and (4) integrate the two accounting programs into a single program and develop a Web-based interface to the integrated program that incorporates simple and reliable data entry that is automated to the fullest extent possible. This report describes the results of completing objectives (2), (3), and (4) of that study. The accounting program for Monument Creek was developed first by (1) using the existing accounting program for Fountain Creek as a prototype, (2) incorporating the transit-loss results from a stream-aquifer modeling analysis of Monument Creek, and (3) developing new output reports. The capabilities of the existing accounting program for Fountain Creek then were incorporated into the program for Monument Creek and the output reports were expanded to include Fountain Creek. A Web-based interface to the new transit-loss accounting program then was developed that provided automated data entry. An integrated system of 34 nodes and 33 subreaches was integrated by combining the independent node and subreach systems used in the previously completed stream-aquifer modeling studies for the Monument and Fountain Creek reaches. Important operational criteria that were implemented in the new transit-loss accounting program for Monument and Fountain Creeks included the following: (1) Retain all the reusable water-management capabilities incorporated into the existing accounting program for Fountain Creek; (2) enable daily accounting and transit

  20. Operation of NIM5 fountain with 1.5x10-15 uncertainty and design of new NIM6 in NIM

    NASA Astrophysics Data System (ADS)

    Fang, F.; Liu, N.; Liu, K.; Chen, W.; Suo, R.; Li, Tianchu

    2016-06-01

    The cesium fountain primary frequency standard NIM5 started to operate since 2008 and started to report to BIPM since 2014. The major constrains of NIM5 is a relatively large background signal at the detection and microwave leakages due to the Ramsey cavity. A new fountain clock NIM6 is under construction. Besides some improvements on the vacuum system, a new Ramsey cavity and a microwave synthesizer are made to reduce the Type B uncertainty. Another feature of NIM6 is collecting atoms from a MOT loading optical molasses to get more atoms with a more uniform density distribution. With a new frequency synthesizer based on cryogenic sapphire oscillator (CSO), NIM6 is aiming to reach the quantum projection noise, thus leading to a reduced Type A uncertainty compared with NIM5.

  1. Products of Submarine Fountains and Bubble-burst Eruptive Activity at 1200 m on West Mata Volcano, Lau Basin

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Rubin, K. H.; Keller, N. S.

    2009-12-01

    An eruption was observed and sampled at West Mata Volcano using ROV JASON II for 5 days in May 2009 during the NSF-NOAA eruption response cruise to this region of suspected volcanic activity. Activity was focused near the summit at the Prometheus and Hades vents. Prometheus erupted almost exclusively as low-level fountains. Activity at Hades cycled between vigorous degassing, low fountains, and bubble-bursts, building up and partially collapsing a small spatter/scoria cone and feeding short sheet-like and pillow flows. Fire fountains at Prometheus produced mostly small primary pyroclasts that include Pele's hair and fluidal fragments of highly vesicular volcanic glass. These fragments have mostly shattered and broken surfaces, although smooth spatter-like surfaces also occur. As activity wanes, glow in the vent fades, and denser, sometimes altered volcanic clasts are incorporated into the eruption. The latter are likely from the conduit walls and/or vent-rim ejecta, drawn back into the vent by inrushing seawater that replaces water entrained in the rising volcanic plume. Repeated recycling of previously erupted materials eventually produces rounded clasts resembling beach cobbles and pitted surfaces on broken phenocrysts of pyroxene and olivine. We estimate that roughly 33% of near vent ejecta are recycled. Our best sample of this ejecta type was deposited in the drawer of the JASON II ROV during a particularly large explosion that occurred during plume sampling immediately above the vent. Elemental sulfur spherules up to 5 mm in diameter are common in ejecta from both vents and occur inside some of the lava fragments Hades activity included dramatic bubble-bursts unlike anything previously observed under water. The lava bubbles, sometimes occurring in rapid-fire sequence, collapsed in the water-column, producing fragments that are quenched in less than a second to form Pele's hair, limu o Pele, spatter-like lava blobs, and scoria. All are highly vesicular

  2. Cusp Ion Fountain Observations from the e-POP Suprathermal Electron Imager (SEI) with DMSP and RISR-N conjunctions

    NASA Astrophysics Data System (ADS)

    Shen, Y.; Knudsen, D. J.; Burchill, J. K.; Howarth, A. D.; Yau, A. W.; Redmon, R. J.

    2015-12-01

    Low-energy (<10 eV) ion upflows associated with ambipolar ion acceleration in the cusp/cleft and polar cap regions are investigated using conjunctions of the Enhanced Polar Outflow Probe (e-POP) satellite, the Resolute Bay Incoherent Scatter Radar (RISR-N) and the DMSP satellites in June 2014. e-POP encountered the cusp/cleft ion fountain at 10-14 MLT and around 1000 km altitude during these experiments. Such intermediate-altitude observations of ion upflow have been sampled only rarely by previous satellite missions and ground-based radars. The Suprathermal Electron Imager (SEI) onboard e-POP measures two-dimensional ion distribution functions with a frame rate of 100 images per second, from which, high-precision energy and angle information of entering ions can be inferred. Large field-aligned ion bulk flow velocities (2.5 km/s) are estimated from the angle information with a resolution of the order of 25 m/s. The ion velocities were, in general, upward in the cusp region and downward in the polar cap region. The ion temperatures have been resolved by investigating the slop shape of the distribution function. It has been found that only weak perpendicular (to B) heating occurred during these events, which when combined with the simultaneous soft electron precipitation observed by the DMSP SSJ/4 instrument, suggests that ambipolar electric fields play a dominant role in accelerating ions upward at and below 1000 km. Also, structured DC field-aligned currents derived from the magnetic field instrument (MGF) onboard e-POP are found to be well-correlated with upflow velocities. In addition, ion composition information is available from e-POP's ion mass spectrometer (IRM). Oxygen ions (O+) were found to dominate (85%) in the identified events, accompanied by a small fraction (15%) of hydrogen ions (H+) and helium ions (He+). We will compare these in situ measurements with RISR-N observations in order to further our understanding of the mechanisms responsible for, and

  3. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, Ashley G.; Keszthelyi, Laszlo P.; McEwen, Alfred S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μm) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

  4. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, A.G.; Keszthelyi, L.; McEwen, A.S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 ??m) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale. ?? 2011 by the American Geophysical Union.

  5. A reconnaissance water-quality appraisal of the Fountain Creek alluvial aquifer between Colorado Springs and Pueblo, Colorado, including trace elements and organic constituents

    USGS Publications Warehouse

    Cain, Doug; Edelmann, Patrick

    1986-01-01

    This report describes the hydrology and chemical quality of water in the stream-aquifer system along Fountain Creek and relates groundwater quality to land use, water use, and wastewater discharges. The alluvial aquifer, which is underlain by shale bedrock, is transmissive, extensively pumped, and primarily is recharged by Fountain Creek and irrigation-return flow. Groundwater flows south about 20 ft/day, average residence time is less than 10 yr. Land use primarily is urban in the northern one-third and agricultural in the southern two-thirds of the area. Major ions, boron, iron, lithium, selenium, strontium, and uranium increased in concentration downgradient. The largest concentrations of nitrogen and detergents were in the northern end of the area because of recharge of sewage effluent in Fountain Creek. Other trace elements usually were present in concentrations less than 20 mg/L. Volatile organic compounds were detected in water from 11 of 20 wells sampled. Samples from 4 of the 20 wells were analyzed for semivolatile organics using a closed-loop stripping technique, which detected additional compounds at nanogram/L concentrations. (USGS)

  6. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    NASA Astrophysics Data System (ADS)

    Davies, Ashley Gerard; Keszthelyi, Laszlo; McEwen, Alfred S.

    2011-11-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μm) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

  7. Reconnaissance water quality appraisal of the Fountain Creek alluvial aquifer between Colorado Springs and Pueblo, Colorado, including trace elements and organic constituents

    SciTech Connect

    Cain, D.; Edelmann, P.

    1986-01-01

    This report describes the hydrology and chemical quality of water in the stream-aquifer system along Fountain Creek and relates groundwater quality to land use, water use, and wastewater discharges. The alluvial aquifer, which is underlain by shale bedrock, is transmissive, extensively pumped, and primarily is recharged by Fountain Creek and irrigation-return flow. Groundwater flows south about 20 ft/day, average residence time is less than 10 yr. Land use primarily is urban in the northern one-third and agricultural in the southern two-thirds of the area. Major ions, boron, iron, lithium, selenium, strontium, and uranium increased in concentration downgradient. The largest concentrations of nitrogen and detergents were in the northern end of the area because of recharge of sewage effluent in Fountain Creek. Other trace elements usually were present in concentrations less than 20 mg/L. Volatile organic compounds were detected in water from 11 of 20 wells sampled. Samples from 4 of the 20 wells were analyzed for semivolatile organics using a closed-loop stripping technique, which detected additional compound at nanogram/L concentrations. 35 refs., 11 figs., 6 tabs.

  8. FOREWORD: 27th International Conference on Low Temperature Physics (LT27)

    NASA Astrophysics Data System (ADS)

    Calzetta, Esteban

    2014-12-01

    The Low Temperature Physics Conference is an international event held every three years, under the auspices of the IUPAP through its Commission C5 on Low Temperature Physics. These conferences aim at the exchange of information and views among the members of the international scientific community in the general field of Low Temperature Physics, promoting the excellence of invited and contributed presentations. It is a tradition that LT offers updates on the various topics, provided by the highest representatives of the field, as well as oral and poster contributions in the different areas. LT27 was the first conference of the series that took place in South America. It was therefore a particular challenge for us and it is a source of pride to present these Proceedings as proof of the wonderful scientific atmosphere at the meeting. We wish to acknowledge our host institutions, sponsors, and the many people whose work made this meeting possible. Our appreciation goes to all of them, as well as to speakers and attendants.

  9. Simulation-Based e-Learning Tools for Science,Engineering, and Technology Education(SimBeLT)

    NASA Astrophysics Data System (ADS)

    Davis, Doyle V.; Cherner, Y.

    2006-12-01

    The focus of Project SimBeLT is the research, development, testing, and dissemination of a new type of simulation-based integrated e-learning set of modules for two-year college technical and engineering curricula in the areas of thermodynamics, fluid physics, and fiber optics that can also be used in secondary schools and four-year colleges. A collection of sophisticated virtual labs is the core component of the SimBeLT modules. These labs will be designed to enhance the understanding of technical concepts and underlying fundamental principles of these topics, as well as to master certain performance based skills online. SimBeLT software will help educators to meet the National Science Education Standard that "learning science and technology is something that students do, not something that is done to them". A major component of Project SimBeLT is the development of multi-layered technology-oriented virtual labs that realistically mimic workplace-like environments. Dynamic data exchange between simulations will be implemented and links with instant instructional messages and data handling tools will be realized. A second important goal of Project SimBeLT labs is to bridge technical skills and scientific knowledge by enhancing the teaching and learning of specific scientific or engineering subjects. SimBeLT builds upon research and outcomes of interactive teaching strategies and tools developed through prior NSF funding (http://webphysics.nhctc.edu/compact/index.html) (Project SimBeLT is partially supported by a grant from the National Science Foundation DUE-0603277)

  10. Computer Code

    NASA Technical Reports Server (NTRS)

    1985-01-01

    COSMIC MINIVER, a computer code developed by NASA for analyzing aerodynamic heating and heat transfer on the Space Shuttle, has been used by Marquardt Company to analyze heat transfer on Navy/Air Force missile bodies. The code analyzes heat transfer by four different methods which can be compared for accuracy. MINIVER saved Marquardt three months in computer time and $15,000.