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Sample records for condensation nucleus counter

  1. Operation of the Airmodus A11 nano Condensation Nucleus Counter at various inlet pressures, various operation temperatures and design of a new inlet system

    NASA Astrophysics Data System (ADS)

    Kangasluoma, J.; Franchin, A.; Duplissy, J.; Ahonen, L.; Korhonen, F.; Attoui, M.; Mikkilä, J.; Lehtipalo, K.; Vanhanen, J.; Kulmala, M.; Petäjä, T.

    2015-08-01

    Measuring sub-3 nm particles outside of controlled laboratory conditions is a challenging task, as many of the instruments are operated at their limits and are subjected to changing ambient conditions. In this study, we advance the current understanding on the operation of Airmodus A11 nano Condensation Nucleus Counter (nCNC), which consists of a A10 Particle Size Magnifier (PSM) and A20 condensation particle counter (CPC). We explore the effect of the inlet line pressure on the measured particle concentration. We identify two different regions inside the instrument where supersaturation of working fluid can take place. We show the possibility of varying the cut-off of the instrument from 1 to 6 nm, a wider size range than the one usually covered by the PSM. We also present a new inlet system, which allows automated measurements of the background, minimizes the diffusion losses in the sampling line and is equipped with an electrostatic filter to remove ions. Finally, our view of the guidelines for optimal use of the Airmodus nCNC are provided.

  2. Operation of the Airmodus A11 nano Condensation Nucleus Counter at various inlet pressures and various operation temperatures, and design of a new inlet system

    NASA Astrophysics Data System (ADS)

    Kangasluoma, Juha; Franchin, Alessandro; Duplissy, Jonahtan; Ahonen, Lauri; Korhonen, Frans; Attoui, Michel; Mikkilä, Jyri; Lehtipalo, Katrianne; Vanhanen, Joonas; Kulmala, Markku; Petäjä, Tuukka

    2016-07-01

    Measuring sub-3 nm particles outside of controlled laboratory conditions is a challenging task, as many of the instruments are operated at their limits and are subject to changing ambient conditions. In this study, we advance the current understanding of the operation of the Airmodus A11 nano Condensation Nucleus Counter (nCNC), which consists of an A10 Particle Size Magnifier (PSM) and an A20 Condensation Particle Counter (CPC). The effect of the inlet line pressure on the measured particle concentration was measured, and two separate regions inside the A10, where supersaturation of working fluid can take place, were identified. The possibility of varying the lower cut-off diameter of the nCNC was investigated; by scanning the growth tube temperature, the range of the lower cut-off was extended from 1-2.5 to 1-6 nm. Here we present a new inlet system, which allows automated measurement of the background concentration of homogeneously nucleated droplets, minimizes the diffusion losses in the sampling line and is equipped with an electrostatic filter to remove ions smaller than approximately 4.5 nm. Finally, our view of the guidelines for the optimal use of the Airmodus nCNC is provided.

  3. Improved Cloud Condensation Nucleus Spectrometer

    NASA Technical Reports Server (NTRS)

    Leu, Ming-Taun

    2010-01-01

    An improved thermal-gradient cloud condensation nucleus spectrometer (CCNS) has been designed to provide several enhancements over prior thermal- gradient counters, including fast response and high-sensitivity detection covering a wide range of supersaturations. CCNSs are used in laboratory research on the relationships among aerosols, supersaturation of air, and the formation of clouds. The operational characteristics of prior counters are such that it takes long times to determine aerosol critical supersaturations. Hence, there is a need for a CCNS capable of rapid scanning through a wide range of supersaturations. The present improved CCNS satisfies this need. The improved thermal-gradient CCNS (see Figure 1) incorporates the following notable features: a) The main chamber is bounded on the top and bottom by parallel thick copper plates, which are joined by a thermally conductive vertical wall on one side and a thermally nonconductive wall on the opposite side. b) To establish a temperature gradient needed to establish a supersaturation gradient, water at two different regulated temperatures is pumped through tubes along the edges of the copper plates at the thermally-nonconductive-wall side. Figure 2 presents an example of temperature and supersaturation gradients for one combination of regulated temperatures at the thermally-nonconductive-wall edges of the copper plates. c) To enable measurement of the temperature gradient, ten thermocouples are cemented to the external surfaces of the copper plates (five on the top plate and five on the bottom plate), spaced at equal intervals along the width axis of the main chamber near the outlet end. d) Pieces of filter paper or cotton felt are cemented onto the interior surfaces of the copper plates and, prior to each experimental run, are saturated with water to establish a supersaturation field inside the main chamber. e) A flow of monodisperse aerosol and a dilution flow of humid air are introduced into the main

  4. Calibration of TSI model 3025 ultrafine condensation particle counter

    SciTech Connect

    Kesten, J.; Reineking, A.; Porstendoerfer, J. )

    1991-01-01

    The registration efficiency of the TSI model 3025 ultrafine condensation particle counter for Ag and NaCl particles of between 2 and 20 nm in diameter was determined. Taking into account the different shapes of the input aerosol size distributions entering the differential mobility analyzer (DMA) and the transfer function of the DMA, the counting efficiencies of condensation nucleus counters (CNC) for monodisperse Ag and NaCl particles were estimated. In addition, the dependence of the CNC registration efficiency on the particle concentration was investigated.

  5. Development of a Mobile Ice Nucleus Counter

    SciTech Connect

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70°C, and a single stage system can operate the warm wall at -45C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  6. Condensation Particle Counter Instrument Handbook

    SciTech Connect

    Kuang, C.

    2016-02-01

    The Model 3772 CPC is a compact, rugged, and full-featured instrument that detects airborne particles down to 10 nm in diameter, at an aerosol flow rate of 1.0 lpm, over a concentration range from 0 to 1x104 #/cc. This CPC is ideally suited for applications without high concentration measurements, such as basic aerosol research, filter and air-cleaner testing, particle counter calibrations, environmental monitoring, mobile aerosol studies, particle shedding and component testing, and atmospheric and climate studies.

  7. Ultrafine Condensation Particle Counter Instrument Handbook

    SciTech Connect

    Kuang, C.

    2016-02-01

    The Model 3776 Ultrafine Condensation Particle Counter (UCPC; pictured in Appendix A) is designed for researchers interested in airborne particles smaller than 20 nm. With sensitivity to particles down to 2.5 nm in diameter, this UCPC is ideally suited for atmospheric and climate research, particle formation and growth studies, combustion and engine exhaust research, and nanotechnology research.

  8. Rapid Scan Humidified Growth Cloud Condensation Nuclei Counter

    SciTech Connect

    Gregory L. Kok; Athanasios Nenes

    2013-03-13

    This research focused on enhancements to the streamwise thermal gradient cloud condensation nuclei counter to support the rapid scan mode and to enhance the capability for aerosol humidified growth measurements. The research identified the needs for flow system modifications and range of capability for operating the conventional instrument in the rapid scan and humidified growth modes.

  9. Cloud condensation nucleus-sulfate mass relationship and cloud albedo

    NASA Technical Reports Server (NTRS)

    Hegg, Dean A.

    1994-01-01

    Analysis of previously published, simultaneous measurements of cloud condensation nucleus number concentration and sulfate mass concentration suggest a nonlinear relationship between the two variables. This nonlinearity reduces the sensitivity of cloud albedo to changes in the sulfur cycle.

  10. Two New Water-Based Condensation Particle Counters

    NASA Astrophysics Data System (ADS)

    Hering, S. V.; Quant, F. R.

    2005-12-01

    Described here are two new, thermally-diffusive, water-based condensation particle counters (WCPC) for determination of aerosol number concentrations. One of these, the TSI Model 3786 ultrafine WCPC, detects particles as small as 2.5 nm at an aerosol flow rate of 300 cm3/min. The second is a not-yet-commercialized, compact, 12-volt instrument (ME-WCPC) weighing 2.5 kg with a lower size limit of 5 nm, and an upper concentration limit in single-count mode of ~10E7cm-3. In contrast to the cold-walled condensers of the older butanol-based particle counters, these WCPCs use a warm, wet-walled "growth tube" that explicitly takes into account the high diffusivity of water vapor. Because the mass diffusivity of water vapor exceeds the thermal diffusivity of air, the flux of water vapor to the centerline is faster than the heat flux from the walls, thereby producing the supersaturation necessary for particle activation and growth (1). An obvious advantage of the WCPCs over the butanol-based particle counters is the elimination of odor, toxicity and waste disposal issues with the use of butanol. Reported is the field evaluation of the ultrafine- and ME-WCPCs, with comparison to the more well-established butanol-based TSI Model 3010 and 3025 counters. A passive flow system provided a 9:1 dilution of ambient air for the TSI 3010 in order to stay within an acceptable concentration range for that instrument. Equivalency of aerosol sampling rates for all instruments was evaluated through comparison of counting efficiency for near-monodisperse aerosols at with diameters ranging from 50 to 200 nm. Over four weeks of measurements the ultrafine WCPC reported 6% higher concentrations than the ultrafine butanol Model 3025 counter, consistent with the slightly lower size cutoff of the ultrafine WCPC. Concentrations from the ME-WCPC units were higher than for the 10nm cutpoint TSI 3010, but lower than for the 3 nm cutpoint TSI 3025 ultrafine. For all comparisons, the correlation

  11. Ammonium nitrate evaporation and nitric acid condensation in DMT CCN counters

    NASA Astrophysics Data System (ADS)

    Romakkaniemi, S.; Jaatinen, A.; Laaksonen, A.; Nenes, A.; Raatikainen, T.

    2014-05-01

    The effect of inorganic semivolatile aerosol compounds on the cloud condensation nucleus (CCN) activity of aerosol particles was studied by using a computational model for a DMT-CCN counter, a cloud parcel model for condensation kinetics and experiments to quantify the modelled results. Concentrations of water vapour and semivolatiles as well as aerosol trajectories in the CCN column were calculated by a computational fluid dynamics model. These trajectories and vapour concentrations were then used as an input for the cloud parcel model to simulate mass transfer kinetics of water and semivolatiles between aerosol particles and the gas phase. Two different questions were studied: (1) how big a fraction of semivolatiles is evaporated from particles after entering but before particle activation in the DMT-CCN counter? (2) How much can the CCN activity be increased due to condensation of semivolatiles prior to the maximum water supersaturation in the case of high semivolatile concentration in the gas phase? Both experimental and modelling results show that the evaporation of ammonia and nitric acid from ammonium nitrate particles causes a 10 to 15 nm decrease to the critical particle size in supersaturations between 0.1% and 0.7%. On the other hand, the modelling results also show that condensation of nitric acid or similar vapour can increase the CCN activity of nonvolatile aerosol particles, but a very high gas phase concentration (as compared to typical ambient conditions) would be needed. Overall, it is more likely that the CCN activity of semivolatile aerosol is underestimated than overestimated in the measurements conducted in ambient conditions.

  12. A Balloon-Borne Cloud Condensation Nuclei Counter

    NASA Technical Reports Server (NTRS)

    Delene, David J.; Deshler, Terry; Wechsler, Perry; Vali, Gabor A.

    1997-01-01

    A balloon-borne instrument was constructed for observations of vertical profiles of cloud condensation nucleus (CCN) concentrations, active at 1% supersaturation. Droplet concentration in the static thermal-gradient diffusion chamber is deduced from the amount of scattered laser light detected by a photodetector. The photodetector is calibrated using a video camera and computer system to count the number of droplets produced from NaCl aerosol. Preliminary data are available from nine early morning profiles obtained at Laramie, Wyoming, between June 1995 and January 1997. To complement the CCN measurements, instruments that measure condensation nuclei (CN) and aerosols with diameter greater than 0.30 micrometers (D(sub 0.3) were also included on the balloon package. CCN concentrations exhibited a general decrease from the surface to the top of the boundary layers, were generally uniform through well-mixed layers, and show variability above well-mixed layers. In general, the structure of the CCN profile appears to be closely related to the structure in the CN and D(sub 0.3) profiles. Summer profiles generally have CCN concentration greater than 200/cu cm up to 500 mbar, whereas winter profiles are less than 200/cu cm at all levels.

  13. The south pole automatic condensation nuclei counter: instrument details and five years of observations

    SciTech Connect

    Murphy, M.E.; Bodhaine, B.A.

    1980-02-01

    An automatic General Electric (G.E.) condensation nuclei counter has been operating continuously at the Amundson-Scott South Pole station since 1974 as part of the Geophysical Monitoring for Climatic Change (GMCC) program. This instrument (calibrated by a Pollak nuclei counter standard), with its high sensitivity and fast response, can provide continuous aerosol climatology and identify periods of contamination from local sources. The annual variation of nuclei concentration is apparent and is repeatably consistent over the five year period. Nuclei concentrations occasionally reach values as low as 7/cu cm during the austral winter (April through September), begin to increase near the time of astronomical sunrise, and reach values as high as about 240/cu cm during summer months. The continuously operating G.E. condensation nuclei counter in conjunction with the Pollak nuclei counter, have produced an excellent data set over the five year period, 1974-1978.

  14. DESIGN AND PERFORMANCE CHARACTERISTICS OF A TURBULENT MIXING CONDENSATION NUCLEI COUNTER. (R826654)

    EPA Science Inventory

    The design and optimization of operation parameters of a Turbulent Mixing Condensation Nuclei Counter (TMCNC) are discussed as well as its performance using dibutylphthalate (DBP) as the working fluid. A detection limit of 3 nm has been achieved at a flow rate of 2.8 lmin-1<...

  15. Modification of the TSI 3025 condensation particle counter forpulse height analysis

    SciTech Connect

    Marti, J.J.; Weber, R.J.; Saros, M.T.; Vasiliou, J.G.; McMurry, P.H.

    1996-08-01

    Ultrafine particle sizes may be measured over a limited range with an ultrafine condensation particle counter (UCPC) by analyzing photodetector pulse heights. The pulse height analysis(PHA) technique has been employed successfully in our laboratory with a prototype UCPC. However, attempts to incorporate PHA into a commercial UCPC (the TSI model 3025) met with initial lack of success, yielding anomalous and irreproducible pulse height spectra. Operating parameters and subsystems of the commercial UCPC, including condenser/saturator temperatures, aerosol flows, optical system (light source and detector), and post-photodetector electronics, were examined for contributions to the observed pulse height spectra. The optical system, specifically the light source and scattering geometry, was found to be the cause of the anomalous pulse height performance. Replacing the existing 90{degree} scattering, laser light-photodiode detection system with aforward-scattering, white halogen light source and photodiode from an older condensation particle counter (the TSI 3020) resulted in satisfactory pulse height response from the instrument, allowing pulse height analysis with the commercially available UCPC. 4 refs., 2 figs.

  16. Modification of laminar flow ultrafine condensation particle counters for the enhanced detection of 1 nm condensation nuclei

    SciTech Connect

    Kuang, C.; Chen, M.; McMurry, P. H.; Wang, J.

    2011-10-01

    This paper describes simple modifications to thermally diffusive laminar flow ultrafine condensation particle counters (UCPCs) that allow detection of {approx}1 nm condensation nuclei with much higher efficiencies than have been previously reported. These nondestructive modifications were applied to a commercial butanol based UCPC (TSI 3025A) and to a diethylene glycol-based UCPC (UMN DEG-UCPC). Size and charge dependent detection efficiencies using the modified UCPCs (BNL 3025A and BNL DEGUCPC) were measured with high resolution mobility classified aerosols composed of NaCl, W, molecular ion standards of tetraalkyl ammonium bromide, and neutralizer-generated ions. With negatively charged NaCl aerosol, the BNL 3025A and BNL DEGUCPC achieved detection efficiencies of 37% (90x increase over TSI 3025A) at 1.68 nm mobility diameter (1.39 nm geometric diameter) and 23% (8x increase over UMN DEG-UCPC) at 1.19 nm mobility diameter (0.89 nm geometric diameter), respectively. Operating conditions for both UCPCs were identified that allowed negatively charged NaCl and W particles, but not negative ions of exactly the same mobility size, to be efficiently detected. This serendipitous material dependence, which is not fundamentally understood, suggests that vapor condensation might sometimes allow for the discrimination between air 'ions' and charged 'particles.' As a detector in a scanning mobility particle spectrometer (SMPS), a UCPC with this strong material dependence would allow for more accurate measurements of sub-2 nm aerosol size distributions due to the reduced interference from neutralizer-generated ions and atmospheric ions, and provide increased sensitivity for the determination of nucleation rates and initial particle growth rates.

  17. Comparison between two Aitken counters and with cloud condensation nuclei counters at the 1980 International CCN Workshop

    NASA Technical Reports Server (NTRS)

    Rogers, C. F.; Mckenzie, R. L.

    1981-01-01

    The Pollak and the TSI 3020 counters agreed to within about 10% at concentrations below 1000 cu cm, whereas above that concentration, substantial systematic differences were observed. When the test aerosol was monodisperse and the CCN counters were operated at supersaturations that should nucleate all the aerosol, the Pollak counter read about 6% to 20% lower than the CCN counter in the concentration range from 250/cu cm to 1800/cu cm. The TSI 3020 read about 20% lower than the CCN counter at concentrations less than 1000/cu cm, and a factor of about two higher at concentrations above 1000/cu cm.

  18. Detection near 1-nm with a laminar-flow, water-based condensation particle counter

    SciTech Connect

    Hering, Susanne V.; Lewis, Gregory S.; Spielman, Steven R.; Eiguren-Fernandez, Arantzazu; Kreisberg, Nathan M.; Kuang, Chongai; Attoui, Michel

    2016-11-18

    Presented is a laminar-flow, water-based condensation particle counter capable of particle detection near 1 nm. This instrument employs a three-stage, laminar-flow growth tube with a “moderator” stage that reduces the temperature and water content of the output flow without reducing the peak supersaturation, and makes feasible operation at the large temperature differences necessary for achieving high supersaturations. The instrument has an aerosol flow of 0.3 L/min, and does not use a filtered sheath flow. It is referred to as a “versatile” water condensation particle counter, or vWCPC, as operating temperatures can be adjusted in accordance with the cut-point desired. When operated with wall temperatures of ~2°C, >90°C, and ~22°C for the three stages, respectively, the vWCPC detects particles generated from a heated nichrome wire with a 50% efficiency cut-point near 1.6 nm mobility diameter. At these operating temperatures, it also detects 10–20% of large molecular ions formed from passing filtered ambient air through a bipolar ion source. Decreasing the temperature difference between the first two stages, with the first and second stages operated at 10 and 90°C, respectively, essentially eliminates the response to charger ions, and raises the 50% efficiency cut-point for the nichrome wire particles to 1.9 nm mobility diameter. Here, the time response, as measured by rapid removal of an inlet filter, yields a characteristic time constant of 195 ms.

  19. Detection near 1-nm with a laminar-flow, water-based condensation particle counter

    DOE PAGES

    Hering, Susanne V.; Lewis, Gregory S.; Spielman, Steven R.; ...

    2016-11-18

    Presented is a laminar-flow, water-based condensation particle counter capable of particle detection near 1 nm. This instrument employs a three-stage, laminar-flow growth tube with a “moderator” stage that reduces the temperature and water content of the output flow without reducing the peak supersaturation, and makes feasible operation at the large temperature differences necessary for achieving high supersaturations. The instrument has an aerosol flow of 0.3 L/min, and does not use a filtered sheath flow. It is referred to as a “versatile” water condensation particle counter, or vWCPC, as operating temperatures can be adjusted in accordance with the cut-point desired. Whenmore » operated with wall temperatures of ~2°C, >90°C, and ~22°C for the three stages, respectively, the vWCPC detects particles generated from a heated nichrome wire with a 50% efficiency cut-point near 1.6 nm mobility diameter. At these operating temperatures, it also detects 10–20% of large molecular ions formed from passing filtered ambient air through a bipolar ion source. Decreasing the temperature difference between the first two stages, with the first and second stages operated at 10 and 90°C, respectively, essentially eliminates the response to charger ions, and raises the 50% efficiency cut-point for the nichrome wire particles to 1.9 nm mobility diameter. Here, the time response, as measured by rapid removal of an inlet filter, yields a characteristic time constant of 195 ms.« less

  20. Performance of TSI 3760 condensation nuclei counter at reduced pressures and flow rates

    SciTech Connect

    Zhiqun Zhang; Liu, B.Y.H. )

    1991-01-01

    This article describes an experimental study of the performance of the TSI model 3760 clean room condensation nuclei counter (CNC) at various pressures and flow rates. Studies were made to determine the counting efficiency of the instrument in the pressure range of 0.1-1 atom and flow rate range of 0.15-1.4 L/min. The counting efficiency curves were found to be shifted to larger particle sizes as the pressure or flow rate was reduced. The low pressure and low flow rate limits of the instrument were also determined. The numerical model developed in a previous study was used to predict the performance of the CNC. The numerical results were compared with the experimental data and found to agree well in the pressure range of 0.2-1.0 atm and flow rate range of 0.3-1.4 L/min. Discrepancies were found to be more significant at the lower pressures and flow rates.

  1. Water-based condensation particle counters for environmental monitoring of ultrafine particles.

    PubMed

    Liu, Wei; Kaufman, Stanley L; Osmondson, Brian L; Sem, Gilmore J; Quant, Frederick R; Oberreit, Derek R

    2006-04-01

    TSI Inc. (Shoreview, MN) has introduced three new water-based condensation particle counters (WCPCS) that were designed to detect airborne particles larger than 2.5 nm (model 3786), 5 nm (model 3785), and either 10 or 20 nm (model 3782). These WCPCs are well suited for real-time, environmental monitoring of number concentration of airborne ultrafine particles. Their unique design incorporates the use of water as the working fluid instead of alcohol. Water is odor free, readily available, and eliminates the problem of water condensation and absorption into alcohol working fluids during operation in humid environments. In this study, the performance of three TSI WCPCs was characterized for several aerosol compositions, including sucrose, salt (NaCl), dioctyl sebacate (DOS), dioctyl phthalate (DOP), emery oil (poly-alpha-olefin), silver, impurity residue particles, and ambient aerosol particles. All particles were size selected using a nano differential mobility analyzer (nano-DMA; model 3085, TSI Inc.) to create monodisperse challenge aerosols. The challenge aerosol was mixed uniformly with clean makeup flow and split into a WCPC and a reference instrument to determine the counting efficiency of the WCPC. For the model 3785 WCPC, the D50 (i.e., the particle diameter with 50% counting efficiency) was determined to be 3.1 nm for salt particles, 4.7 nm for sucrose and ambient particles, 5.6 nm for silver particles, and >50 nm for ultrapure oil particles. The sensitivity to oil droplets increased dramatically (D50 < 10 nm) when the oil was slightly contaminated. The D50 of model 3786 ultrafine water-based CPC (UWCPC) was 2.4 nm for impurity residue particles. The D50 of the model 3782 WCPC was 10.8 (with a nominal setting of 10 nm) or 19.8 nm (with a nominal setting of 20 nm) for sucrose particles. All three WCPCs have response times of less than 2 or 3 sec and are therefore able to detect fast-changing events.

  2. Scanning supersaturation condensation particle counter applied as a nano-CCN counter for size-resolved analysis of the hygroscopicity and chemical composition of nanoparticles

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Su, H.; Wang, X.; Ma, N.; Wiedensohler, A.; Poschl, U.; Cheng, Y.

    2015-05-01

    Knowledge about the chemical composition of aerosol particles is essential to understand their formation and evolution in the atmosphere. Due to analytical limitations, however, relatively little information is available for sub-10 nm particles. We present the design of a nano-cloud condensation nuclei counter (nano-CCNC) for measuring size-resolved hygroscopicity and inferring chemical composition of sub-10 nm aerosol particles. We extend the use of counting efficiency spectra from a water-based condensation particle counter (CPC) and link it to the analysis of CCN activation spectra, which provides a theoretical basis for the application of a scanning supersaturation CPC (SS-CPC) as a nano-CCNC. Measurement procedures and data analysis methods are demonstrated through laboratory experiments with monodisperse particles of diameter down to 2.5 nm, where sodium chloride, ammonium sulfate, sucrose and tungsten oxide can be easily discriminated by different characteristic supersaturations of water droplet formation. A near-linear relationship between hygroscopicity parameter κ and organic mass fraction is also found for sucrose-ammonium sulfate mixtures. The design is not limited to the water CPC, but also applies to CPCs with other working fluids (e.g. butanol, perfluorotributylamine). We suggest that a combination of SS-CPCs with multiple working fluids may provide further insight into the chemical composition of nanoparticles and the role of organic and inorganic compounds in the initial steps of atmospheric new particle formation and growth.

  3. Manchester Ice Nucleus Counter (MINC) measurements from the 2007 International workshop on Comparing Ice nucleation Measuring Systems (ICIS-2007)

    NASA Astrophysics Data System (ADS)

    Jones, H. M.; Flynn, M. J.; Demott, P. J.; Möhler, O.

    2011-01-01

    An ice nucleus counter was developed and constructed to enable investigation of potential ice nucleating materials. The Manchester Ice Nucleus Chamber (MINC) is a concentric-cylinder continuous flow diffusion chamber (CFDC). A full explanation of the MINC instrument is given here, along with first results and a comparison to an established instrument of similar design (Colorado State University CFDC) during sampling of common ice nucleating aerosols at the 2007 International workshop on Comparing Ice nucleation Measuring Systems (ICIS-2007). MINC and CSU-CFDC detected the onset of ice nucleation under similar conditions of temperature and supersaturation for several different types of ice nuclei. Comparisons of the ratio of ice nuclei to total aerosol concentrations as a function of supersaturation with respect to water (SSw) showed agreement within one order of magnitude. Possible reasons for differences between the two instruments relating to differences in their design are discussed, along with suggestions to future improvements to the current design.

  4. Manchester Ice Nucleus Counter (MINC) measurements from the 2007 International workshop on Comparing Ice nucleation Measuring Systems (ICIS-2007)

    NASA Astrophysics Data System (ADS)

    Jones, H. M.; Flynn, M. J.; Demott, P. J.; Möhler, O.

    2010-08-01

    An ice nucleus counter was developed and constructed to enable investigation of potential ice nucleating materials. The Manchester Ice Nucleus Chamber (MINC) is a concentric-cylinder continuous flow diffusion chamber (CFDC). A full explanation of the MINC instrument is given here, along with first results and a comparison to an established instrument of similar design (Colorado State University CFDC) during sampling of common ice nucleating aerosols at the 2007 International workshop on Comparing Ice nucleation Measuring Systems (ICIS-2007). Both instruments detected the onset of ice nucleation under similar conditions of temperature and supersaturation for several different types of ice nuclei. Comparisons of the ratio of ice nuclei to total aerosol concentrations as a function of relative humidity (RH) showed agreement within one order of magnitude. Possible reasons for differences between the two instruments relating to differences in their design are discussed, along with suggestions to future improvements to the current design.

  5. Cloud condensation nucleus activity of secondary organic aerosol particles mixed with sulfate

    NASA Astrophysics Data System (ADS)

    King, Stephanie M.; Rosenoern, Thomas; Shilling, John E.; Chen, Qi; Martin, Scot T.

    2007-12-01

    The cloud condensation nucleus (CCN) activity of organic-sulfate particles was investigated using a steady-state environmental chamber. The organic component consisted of secondary organic aerosol (SOA) generated in the dark from 24 +/- 2 ppb α-pinene for conditions of 300 +/- 5 ppb ozone, 40 +/- 2% relative humidity, and 25 +/- 1°C, with the organic mass loading in the chamber ranging from 23 to 37 μg m-3. CCN analysis was performed for 80- to 150-nm particles having variable organic-sulfate volume fractions, which were estimated from the diameter of the organic-sulfate particle relative to that of the seed as well as independently from mass spectra. Critical supersaturation, which increased for greater SOA volume fraction and smaller particle diameter, was well predicted by a Köhler model having two components, one for ammonium sulfate and another for SOA. The entire data set could be successfully modeled by a single suite of effective chemical parameters for SOA. The results suggest that the effects of limited organic solubility in mixed SOA-sulfate particles may be reliably omitted in the treatment of cloud droplet formation.

  6. Opposite counter-ion effects on condensed bundles of highly charged supramolecular nanotubes in water.

    PubMed

    Wei, Shenghui; Chen, Mingming; Wei, Chengsha; Huang, Ningdong; Li, Liangbin

    2016-07-20

    Although ion specificity in aqueous solutions is well known, its manifestation in unconventional strong electrostatic interactions remains implicit. Herein, the ionic effects in dense packing of highly charged polyelectrolytes are investigated in supramolecular nanotube prototypes. Distinctive behaviors of the orthorhombic arrays composed of supramolecular nanotubes in various aqueous solutions were observed by Small Angle X-ray Scattering (SAXS), depending on the counter-ions' size and affiliation to the surface -COO(-) groups. Bigger tetra-alkyl ammonium (TAA(+)) cations weakly bonding to -COO(-) will compress the orthorhombic arrays, while expansion is induced by smaller alkaline metal (M(+)) ions with strong affiliation to -COO(-). Careful analysis of the changes in the SAXS peaks with different counter/co-ion combinations indicates dissimilar mechanisms underlying the two explicit types of ionic effects. The pH measurements are in line with the ion specificity by SAXS and reveal the strong electrostatic character of the system. It is proposed that the small distances between the charged surfaces, in addition to the selective adsorption of counter-ions by the surface charge, bring out the observed distinctive ionic effects. Our results manifest the diverse mechanisms and critical roles of counter-ion effects in strong electrostatic interactions.

  7. Electrical Mobility Spectrometer Using a Diethylene Glycol Condensation Particle Counter for Measurement of Aerosol Size Distributions Down to 1 nm

    SciTech Connect

    Jiang, J.; Kuang, C.; Chen, M.; Attoui, M.; McMurry, P. H.

    2011-02-01

    We report a new scanning mobility particle spectrometer (SMPS) for measuring number size distributions of particles down to {approx}1 nm mobility diameter. This SMPS includes an aerosol charger, a TSI 3085 nano differential mobility analyzer (nanoDMA), an ultrafine condensation particle counter (UCPC) using diethylene glycol (DEG) as the working fluid, and a conventional butanol CPC (the 'booster') to detect the small droplets leaving the DEG UCPC. The response of the DEG UCPC to negatively charged sodium chloride particles with mobility diameters ranging from 1-6 nm was measured. The sensitivity of the DEG UCPC to particle composition was also studied by comparing its response to positively charged 1.47 and 1.70 nm tetra-alkyl ammonium ions, sodium chloride, and silver particles. A high resolution differential mobility analyzer was used to generate the test particles. These results show that the response of this UCPC to sub-2 nm particles is sensitive to particle composition. The applicability of the new SMPS for atmospheric measurement was demonstrated during the Nucleation and Cloud Condensation Nuclei (NCCN) field campaign (Atlanta, Georgia, summer 2009). We operated the instrument at saturator and condenser temperatures that allowed the efficient detection of sodium chloride particles but not of air ions having the same mobility. We found that particles as small as 1 nm were detected during nucleation events but not at other times. Factors affecting size distribution measurements, including aerosol charging in the 1-10 nm size range, are discussed. For the charger used in this study, bipolar charging was found to be more effective for sub-2 nm particles than unipolar charging. No ion induced nucleation inside the charger was observed during the NCCN campaign.

  8. Measurements of Cloud Characteristics with a Ceilometer and Supporting Measurements with a Water Based Condensation Particle Counter

    NASA Astrophysics Data System (ADS)

    Vishnu, R.; Muralidas, S.; Mohankumar, G.; Varikoden, Hamza; v, Sasi Kumar; Sampath, S.; Vishnu, R.

    A Vaisala Laser Ceilometer which employs the LIDAR technique with a 910 nm laser diode for measurement of cloud base height, sky condition and vertical visibility was set up at a tropical coastal station Thiruvananthapuram (8.29° N, 76.59° E)at Kerala state, India. Measurements of cloud base height during different rain spells were made to understand the basic nature of cloud during different types of rain episodes such as convective and stratiform rains. Information on diurnal variation of cloud base height for different seasons has been obtained. The dominant altitude range of cloud occurrence is found to be below 1.5 km for clouds of all rainy seasons. The southwest monsoon clouds were dominant below 500 m also. The Ceilometer with its data on visibility also gave a picture of particles that can scatter the laser which includes water in liquid and ice phases. During dry weather conditions visibility below 1 km was found to be relatively low. To understand the cause of visibility change, a water based condensation nuclei counter manufactured by M/s TSI Inc, USA was employed and concentration monitored. An attempt was also made to get the cloud base height characteristics on a mountain slope to understand the orographic lifting of clouds due to mountain slope during different rainy seasons. At the mountain location data on cloud base measurements during cloud formation by orographic lifting of water vapour during thunderstorm months of the region is also presented and discussed.

  9. Partitioning of mobile ions between ion exchange polymers and aqueous salt solutions: importance of counter-ion condensation.

    PubMed

    Kamcev, Jovan; Galizia, Michele; Benedetti, Francesco M; Jang, Eui-Soung; Paul, Donald R; Freeman, Benny D; Manning, Gerald S

    2016-02-17

    Equilibrium partitioning of ions between a membrane and a contiguous external solution strongly influences transport properties of polymeric membranes used for water purification and energy generation applications. This study presents a theoretical framework to quantitatively predict ion sorption from aqueous electrolytes (e.g., NaCl, MgCl2) into charged (i.e., ion exchange) polymers. The model was compared with experimental NaCl, MgCl2, and CaCl2 sorption data in commercial cation and anion exchange membranes. Ion sorption in charged polymers was modeled using a thermodynamic approach based on Donnan theory coupled with Manning's counter-ion condensation theory to describe non-ideal behavior of ions in the membrane. Ion activity coefficients in solution were calculated using the Pitzer model. The resulting model, with no adjustable parameters, provides remarkably good agreement with experimental values of membrane mobile salt concentration. The generality of the model was further demonstrated using literature data for ion sorption of various electrolytes in charged polymers, including HCl sorption in Nafion.

  10. Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol: the significance of soluble material

    NASA Astrophysics Data System (ADS)

    Garimella, S.; Huang, Y.-w.; Seewald, J. S.; Cziczo, D. J.

    2013-11-01

    This study examines the interaction of clay mineral particles and water vapor to determine the conditions required for cloud droplet formation. Droplet formation conditions are investigated for three clay minerals: illite, sodium-rich montmorillonite, and Arizona Test Dust. Using wet and dry particle generation coupled to a differential mobility analyzer (DMA) and cloud condensation nuclei counter, the critical activation of the clay mineral particles as cloud condensation nuclei is characterized. Electron microscopy (EM) is used to determine non-sphericity in particle shape. EM is also used to determine particle surface area and account for transmission of multiply charged particles by the DMA. Single particle mass spectrometry and ion chromatography are used to investigate soluble material in wet-generated samples and demonstrate that wet and dry generation yield compositionally different particles. Activation results are analyzed in the context of both κ-Köhler theory and Frenkel, Halsey, and Hill (FHH) adsorption activation theory. This study has two main results: (1) κ-Köhler is a suitable framework, less complex than FHH theory, to describe clay mineral nucleation activity despite apparent differences in κ with respect to size. For dry-generated particles the size dependence is likely an artifact of the shape of the size distribution: there is a sharp drop-off in particle concentration at ~300 nm, and a large fraction of particles classified with a mobility diameter less than ~300 nm are actually multiply charged, resulting in a much lower critical supersaturation for droplet activation than expected. For wet-generated particles, deviation from κ-Köhler theory is likely a result of the dissolution and redistribution of soluble material. (2) Wet-generation is found to be unsuitable for simulating the lofting of fresh dry dust because it changes the size-dependent critical supersaturations by fractionating and re-partitioning soluble material.

  11. Cloud Condensation Nucleus Activity of calcite and calcite coated with model humic and fulvic acids

    NASA Astrophysics Data System (ADS)

    Hatch, C. D.; Gierlus, K. M.; Schuttlefield, J. D.; Grassian, V. H.

    2007-12-01

    Many recent studies have shown that organics can alter the water adsorption and cloud condensation nuclei (CCN) activity of common deliquescent species in the Earth's atmosphere. However, very little is known about the effect of organics on water adsorption and CCN activity of common inactive cloud nuclei, such as mineral aerosol. As many studies have shown that a large fraction of unidentified organic material in aerosol particles is composed of polycarboxylic acids resembling humic substances, the presence of these large molecular weight Humic-Like Substances (HULIS) may also alter the water adsorption and CCN activity of mineral aerosol. Thus, we have measured the water adsorption and CCN activity of model humic and fulvic acids. Additionally, the water adsorption and CCN activity of mineral aerosol particles coated with humic and fulvic acids have been studied. We find that humic and fulvic acids show continual multilayer water adsorption as the relative humidity is raised. Additionally, we find that calcite particles mixed with humic and fulvic acids take up more water by mass, by a factor of two, compared to the uncoated calcite particles at approximately 70% RH. CCN measurements also indicate that internally mixed calcite-humic or fulvic acid aerosols are more CCN active than the otherwise inactive, uncoated calcite particles. Our results suggest that mineral aerosol particles coated with high molecular weight organic materials will take up more water and become more efficient CCN in the Earth's atmosphere than single-component mineral aerosol.

  12. Cloud condensation nucleus activity comparison of dry- and wet-generated mineral dust aerosol: the significance of soluble material

    NASA Astrophysics Data System (ADS)

    Garimella, S.; Huang, Y.-W.; Seewald, J. S.; Cziczo, D. J.

    2014-06-01

    This study examines the interaction of clay mineral particles and water vapor for determining the conditions required for cloud droplet formation. Droplet formation conditions are investigated for two common clay minerals, illite and sodium-rich montmorillonite, and an industrially derived sample, Arizona Test Dust. Using wet and dry particle generation coupled to a differential mobility analyzer (DMA) and cloud condensation nuclei counter, the critical activation of the clay mineral particles as cloud condensation nuclei is characterized. Electron microscopy (EM) is used in order to determine non-sphericity in particle shape. It is also used in order to determine particle surface area and account for transmission of multiply charged particles by the DMA. Single particle mass spectrometry and ion chromatography are used to investigate soluble material in wet-generated samples and demonstrate that wet and dry generation yield compositionally different particles. Activation results are analyzed in the context of both κ-Köhler theory (κ-KT) and Frenkel-Halsey-Hill (FHH) adsorption activation theory. This study has two main results: (1) κ-KT is the suitable framework to describe clay mineral nucleation activity. Apparent differences in κ with respect to size arise from an artifact introduced by improper size-selection methodology. For dust particles with mobility sizes larger than ~300 nm, i.e., ones that are within an atmospherically relevant size range, both κ-KT and FHH theory yield similar critical supersaturations. However, the former requires a single hygroscopicity parameter instead of the two adjustable parameters required by the latter. For dry-generated particles, the size dependence of κ is likely an artifact of the shape of the size distribution: there is a sharp drop-off in particle concentration at ~300 nm, and a large fraction of particles classified with a mobility diameter less than ~300 nm are actually multiply charged, resulting in a much

  13. Chemical aging of single and multicomponent biomass burning aerosol surrogate particles by OH: implications for cloud condensation nucleus activity

    NASA Astrophysics Data System (ADS)

    Slade, J. H.; Thalman, R.; Wang, J.; Knopf, D. A.

    2015-09-01

    Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low-soluble single-component OA by OH and O3 can increase their water solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate particles exposed to OH and O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH and O3 exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~ 0.1, indicating that chemically aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH-exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions, chemical

  14. Chemical aging of single and multicomponent biomass burning aerosol surrogate-particles by OH: implications for cloud condensation nucleus activity

    NASA Astrophysics Data System (ADS)

    Slade, J. H.; Thalman, R.; Wang, J.; Knopf, D. A.

    2015-03-01

    Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low soluble single-component OA by OH and O3 can increase their water-solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water-solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate-particles exposed to OH and O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH/O3 exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~0.1, indicating that chemically-aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally-mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions, chemical aging

  15. Chemical aging of single and multicomponent biomass burning aerosol surrogate-particles by OH: Implications for cloud condensation nucleus activity

    DOE PAGES

    Thalman, R.; Thalman, R.; Wang, J.; ...

    2015-03-06

    Multiphase OH and O₃ oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low soluble single-component OA by OH and O₃ can increase their water-solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water-solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate-particles exposed to OH andmore » O₃ is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH/O₃ exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O₃ exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~0.1, indicating that chemically-aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally-mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH exposed MNC-coated KS particles is similar to the OH unexposed atomized 1:1 by mass MNC: KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions

  16. Chemical aging of single and multicomponent biomass burning aerosol surrogate particles by OH: implications for cloud condensation nucleus activity

    DOE PAGES

    Slade, J. H.; Thalman, R.; Wang, J.; ...

    2015-09-14

    Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low-soluble single-component OA by OH and O3 can increase their water solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate particles exposed tomore » OH and O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH and O3 exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~ 0.1, indicating that chemically aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH-exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions

  17. Chemical aging of single and multicomponent biomass burning aerosol surrogate-particles by OH: Implications for cloud condensation nucleus activity

    SciTech Connect

    Thalman, R.; Thalman, R.; Wang, J.; Knopf, D. A.

    2015-03-06

    Multiphase OH and O₃ oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low soluble single-component OA by OH and O₃ can increase their water-solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water-solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate-particles exposed to OH and O₃ is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH/O₃ exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O₃ exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~0.1, indicating that chemically-aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally-mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH exposed MNC-coated KS particles is similar to the OH unexposed atomized 1:1 by mass MNC: KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions, chemical

  18. The influence of the form of condensation nucleus on the formation and propagation of acid precipitation near operating TPS

    NASA Astrophysics Data System (ADS)

    Gvozdyakov, D. V.; Gubin, V. E.

    2015-01-01

    The results of numerical studies of condensation on the surface of the air component of atmospheric condensation nuclei of various shapes. Mathematical modeling performed at ambient temperatures typical of summer and winter seasons. It is found that the trajectory of motion of particles of various shapes differ significantly. Numerical studies were carried out at atmospheric parameters corresponding airspace adjacent to the areas of the TPP. Testing results obtained audited conservative difference scheme.

  19. Particle production in the Color Glass Condensate: from electron-proton DIS to proton-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Lappi, T.; Mäntysaari, H.

    2014-06-01

    We study single inclusive hadron production in proton-proton and proton-nucleus collisions in the CGC framework. The parameters in the calculation are obtained by fitting electron-proton deep inelastic scattering data. The obtained dipole-proton amplitude is generalized to dipole-nucleus scattering without any additional nuclear parameters other than the Woods-Saxon distribution. We show that it is possible to use an initial condition without an anomalous dimension and still obtain a good description of the HERA inclusive cross section and LHC single particle production measurements. We argue that one must consistently use the proton transverse area as measured by a high virtuality probe in DIS also for the single inclusive cross section in proton-proton and proton-nucleus collisions, and obtain a nuclear modification factor RpA that at midrapidity approaches unity at large momenta and at all energies.

  20. Comparison of the DiSCmini aerosol monitor to a handheld condensation particle counter and a scanning mobility particle sizer for submicrometer sodium chloride and metal aerosols

    PubMed Central

    Mills, Jessica B.; Park, Jae Hong; Peters, Thomas M.

    2016-01-01

    We evaluated the robust, lightweight DiSCmini (DM) aerosol monitor for its ability to measure the concentration and mean diameter of submicrometer aerosols. Tests were conducted with monodispersed and polydispersed aerosols composed of two particle types (sodium chloride, NaCl, and spark generated metal particles, which simulate particles found in welding fume) at three different steady-state concentration ranges (Low, <103; Medium, 103–104; and High, >104 particles/cm3). Particle number concentration, lung deposited surface area (LDSA) concentration, and mean size measured with the DM were compared to those measured with reference instruments, a scanning mobility particle sizer (SMPS) and a handheld condensation particle counter (CPC). Particle number concentrations measured with the DM were within 21% of those measured by reference instruments for polydisperse aerosols. Poorer agreement was observed for monodispersed aerosols (±35% for most tests and +130% for 300-nm NaCl). LDSA concentrations measured by the DM were 96% to 155% of those estimated with the SMPS. The geometric mean diameters measured with the DM were within 30% of those measured with the SMPS for monodispersed aerosols and within 25% for polydispersed aerosols (except for the case when the aerosol contained a substantial number of particles larger than 300 nm). The accuracy of the DM is reasonable for particles smaller than 300 nm but caution should be exercised when particles larger than 300 nm are present. PMID:23473056

  1. Comparison of the DiSCmini aerosol monitor to a handheld condensation particle counter and a scanning mobility particle sizer for submicrometer sodium chloride and metal aerosols.

    PubMed

    Mills, Jessica B; Park, Jae Hong; Peters, Thomas M

    2013-01-01

    We evaluated the robust, lightweight DiSCmini (DM) aerosol monitor for its ability to measure the concentration and mean diameter of submicrometer aerosols. Tests were conducted with monodispersed and polydispersed aerosols composed of two particle types (sodium chloride [NaCl] and spark-generated metal particles, which simulate particles found in welding fume) at three different steady-state concentration ranges (Low, <10(3); Medium, 10(3)-10(4); and High, >10(4) particles/cm(3)). Particle number concentration, lung deposited surface area (LDSA) concentration, and mean size measured with the DM were compared with those measured with reference instruments, a scanning mobility particle sizer (SMPS), and a handheld condensation particle counter (CPC). Particle number concentrations measured with the DM were within 16% of those measured by the CPC for polydispersed aerosols. Poorer agreement was observed for monodispersed aerosols (±35% for most tests and +101% for 300-nm NaCl). LDSA concentrations measured by the DM were 96% to 155% of those estimated with the SMPS. The geometric mean diameters measured with the DM were within 30% of those measured with the SMPS for monodispersed aerosols and within 25% for polydispersed aerosols (except for the case when the aerosol contained a substantial number of particles larger than 300 nm). The accuracy of the DM is reasonable for particles smaller than 300 nm, but caution should be exercised when particles larger than 300 nm are present. [Supplementary materials are available for this article. Go to the publisher's online edition of the Journal of Occupational and Environmental Hygiene for the following free supplemental resources: manufacturer-reported capabilities of instruments used, and information from the SMPS measurements for polydispersed test particles.].

  2. Radiation Counters

    DOEpatents

    Simpson, Jr, J A

    1950-01-31

    Geiger-Mueller and proportional counters operating at low potentials (about 125-300 v) obtained by utilizing certain ratios of diameters of the electrodes and particular mixtures of noble gases as the ionizing medium are covered in this application.

  3. Observations of anthropogenic cloud condensation nuclei

    NASA Technical Reports Server (NTRS)

    Hudson, James G.

    1990-01-01

    Cloud Condensation Nuclei (CCN) concentrations and spectral measurements obtained with the DRI instantaneous CCN spectrometer (Hudson, 1989) over the last few years are presented. The climatic importance of cloud microphysics has been pointed out. The particles which affect cloud microphysics are cloud condensation nuclei (CCN). The commonly-observed order of magnitude difference in cloud droplet concentrations between maritime and continental air masses (i.e., Squires, 1958) was determined to be caused by systematic differences in the concentrations of CCN between continental and maritime air masses (e.g., Twomey and Wojciechowski, 1969). Twomey (1977) first pointed out that cloud microphysics also affects the radiative properties of clouds. Thus continental and anthropogenic CCN could affect global temperature. Resolution of this Twomey effect requires answers to two questions - whether antropogenic CCN are a significant contribution to atmospheric CCN, and whether they are actually affecting cloud microphysics to an extent which is of climatic importance. The reasons for the contrast between continental and maritime CCN concentration are not understood. The question of the relative importance of anthropogenic CCN is addressed. These observations should shed light on this complex question although further research is being conducted in order to produce more quantitative answers. Accompanying CN measurements made with a TSI 3020 condensation nucleus (CN) counter are also presented.

  4. Aerosol particle number concentration measurements in five European cities using TSI-3022 condensation particle counter over a three-year period during health effects of air pollution on susceptible subpopulations.

    PubMed

    Aalto, Pasi; Hämeri, Kaarle; Paatero, Pentti; Kulmala, Markku; Bellander, Tom; Berglind, Niklas; Bouso, Laura; Castaño-Vinyals, Gemma; Sunyer, Jordi; Cattani, Giorgio; Marconi, Achille; Cyrys, Josef; von Klot, Stephanie; Peters, Annette; Zetzsche, Katrin; Lanki, Timo; Pekkanen, Juha; Nyberg, Fredrik; Sjövall, Billy; Forastiere, Francesco

    2005-08-01

    In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The measurements have been carried out in Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation particle counter (TSI model 3022). The results show that in all of the studied cities, the winter concentrations are higher than the summer concentrations. In Helsinki and in Stockholm, winter concentrations are higher by a factor of two and in Augsburg almost by a factor of three compared with summer months. The winter maximum of the monthly average concentrations in these cities is between 10,000 cm(-3) and 20,000 cm(-3), whereas the summer min is approximately 5000-6000 cm(-3). In Rome and in Barcelona, the winters are more polluted compared with summers by as much as a factor of 4-10. The winter maximum in both Rome and Barcelona is close to 100,000 cm(-3), whereas the summer minimum is > 10,000 cm(-3). During the weekdays the maximum of the hourly average concentrations in all of the cities is detected during the morning hours between 7 and 10 a.m. The evening maxima were present in Barcelona, Rome, and Augsburg, but these were not as pronounced as the morning ones. The daily maxima in Helsinki and Stockholm are close or even lower than the daily minima in the more polluted cities. The concentrations between these two groups of cities are different with a factor of about five during the whole day. The study pointed out the influence of the selection of the measurement site and the configuration of the sampling line on the observed concentrations.

  5. PULSE COUNTER

    DOEpatents

    Trumbo, D.E.

    1959-02-10

    A transistorized pulse-counting circuit adapted for use with nuclear radiation detecting detecting devices to provide a small, light weight portable counter is reported. The small size and low power requirements of the transistor are of particular value in this instance. The circuit provides an adjustable count scale with a single transistor which is triggered by the accumulated charge on a storage capacitor.

  6. Cherenkov Counters

    SciTech Connect

    Barbero, Marlon

    2012-04-19

    When a charged particle passes through an optically transparent medium with a velocity greater than the phase velocity of light in that medium, it emits prompt photons, called Cherenkov radiation, at a characteristic polar angle that depends on the particle velocity. Cherenkov counters are particle detectors that make use of this radiation. Uses include prompt particle counting, the detection of fast particles, the measurement of particle masses, and the tracking or localization of events in very large, natural radiators such as the atmosphere, or natural ice fields, like those at the South Pole in Antarctica. Cherenkov counters are used in a number of different fields, including high energy and nuclear physics detectors at particle accelerators, in nuclear reactors, cosmic ray detectors, particle astrophysics detectors and neutrino astronomy, and in biomedicine for labeling certain biological molecules.

  7. AUTOMATIC COUNTER

    DOEpatents

    Robinson, H.P.

    1960-06-01

    An automatic counter of alpha particle tracks recorded by a sensitive emulsion of a photographic plate is described. The counter includes a source of mcdulated dark-field illumination for developing light flashes from the recorded particle tracks as the photographic plate is automatically scanned in narrow strips. Photoelectric means convert the light flashes to proportional current pulses for application to an electronic counting circuit. Photoelectric means are further provided for developing a phase reference signal from the photographic plate in such a manner that signals arising from particle tracks not parallel to the edge of the plate are out of phase with the reference signal. The counting circuit includes provision for rejecting the out-of-phase signals resulting from unoriented tracks as well as signals resulting from spurious marks on the plate such as scratches, dust or grain clumpings, etc. The output of the circuit is hence indicative only of the tracks that would be counted by a human operator.

  8. RADIATION COUNTER

    DOEpatents

    Goldsworthy, W.W.

    1958-02-01

    This patent relates to a radiation counter, and more particularly, to a scintillation counter having high uniform sensitivity over a wide area and capable of measuring alpha, beta, and gamma contamination over wide energy ranges, for use in quickly checking the contami-nation of personnel. Several photomultiplier tubes are disposed in parallel relationship with a light tight housing behind a wall of scintillation material. Mounted within the housing with the photomultipliers are circuit means for producing an audible sound for each pulse detected, and a range selector developing a voltage proportional to the repetition rate of the detected pulses and automatically altering its time constant when the voltage reaches a predetermined value, so that manual range adjustment of associated metering means is not required.

  9. Distributed performance counters

    DOEpatents

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  10. CONDENSATION CAN

    DOEpatents

    Booth, E.T. Jr.; Pontius, R.B.; Jacobsohn, B.A.; Slade, C.B.

    1962-03-01

    An apparatus is designed for condensing a vapor to a solid at relatively low back pressures. The apparatus comprises a closed condensing chamber, a vapor inlet tube extending to the central region of the chamber, a co-axial tubular shield surrounding the inlet tube, means for heating the inlet tube at a point outside the condensing chamber, and means for refrigeratirg the said chamber. (AEC)

  11. Condensation polyimides

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M.

    1989-01-01

    Polyimides belong to a class of polymers known as polyheterocyclics. Unlike most other high temperature polymers, polyimides can be prepared from a variety of inexpensive monomers by several synthetic routes. The glass transition and crystalline melt temperature, thermooxidative stability, toughness, dielectric constant, coefficient of thermal expansion, chemical stability, mechanical performance, etc. of polyimides can be controlled within certain boundaries. This versatility has permitted the development of various forms of polyimides. These include adhesives, composite matrices, coatings, films, moldings, fibers, foams and membranes. Polyimides are synthesized through both condensation (step-polymerization) and addition (chain growth polymerization) routes. The precursor materials used in addition polyimides or imide oligomers are prepared by condensation method. High molecular weight polyimide made via polycondensation or step-growth polymerization is studied. The various synthetic routes to condensation polyimides, structure/property relationships of condensation polyimides and composite properties of condensation polyimides are all studied. The focus is on the synthesis and chemical structure/property relationships of polyimides with particular emphasis on materials for composite application.

  12. Real-time {sup 90}Sr Counter

    SciTech Connect

    Kaneko, Naomi; Kawai, Hideyuki; Kodama, Satoshi; Kobayashi, Atsushi; Tabata, Makoto; Ito, Hiroshi; Han, Soorim

    2015-07-01

    Radioisotopes have been emitted around Japan due to a nuclear accident at the Fukushima Daiichi nuclear power station in March 2011. A problem is the contaminated water including the atomic nucleus which relatively has a long half- life time and soluble such as {sup 90}Sr, {sup 137}Cs. Internal exposures by {sup 90}Sr are more dangerous than {sup 137}Cs's because Sr has effective half-life time of 18 years and property of accumulation in a born. We have developed real-time {sup 90}Sr counter which is sensitive beta-ray of maximum kinematic energy of 2.28 MeV from {sup 90}Sr and insensitive of beta-ray of maximum kinematic energy of 1.17 MeV and gamma-ray from {sup 90}Sr by Cherenkov detection. This counter composes of Cerenkov counter, trigger scintillation counter and veto counter. Silica aerogel for Cherenkov counter can obtain refractive index between 1.017 and 1.049 easily. And wavelength shifting fiber (WLSF) is used as a light guide for extending effective area and producing lower cost. A mechanism of the identification of {sup 90}Sr is explained in following. In case of {sup 90}Sr, when the trigger counter reacts on the beta-ray from {sup 90}Sr, aerogel emits the Cherenkov light and WLSF reacts and read the Cherenkov light. On the other hand, in case of {sup 137}Cs, the trigger counter reacts on the beta-ray, aerogel stops the beta- ray and Cherenkov light is not emitted. Therefore, aerogel has a function as a radiator and shielding material. the gamma-ray is not reacted on the lower density detector. Cosmic rays would be also reacted by the veto counter. A prototype counter whose the effective area is 30 cm x 10 cm was obtained (2.0±1.2){sup 3} of mis-identification as {sup 137}Cs/{sup 90}Sr. Detection limit in the surface contamination inspection depends on measurement time and effective area mainly. The sensitivity of wide range, 10{sup -2} - 10{sup 4} Bq/cm{sup 2}, is obtained by adjustment of detection level in circuit of this counter. A lower

  13. FLEXIBLE GEIGER COUNTER

    DOEpatents

    Richter, H.G.; Gillespie, A.S. Jr.

    1963-11-12

    A flexible Geiger counter constructed from materials composed of vinyl chloride polymerized with plasticizers or co-polymers is presented. The counter can be made either by attaching short segments of corrugated plastic sleeving together, or by starting with a length of vacuum cleaner hose composed of the above materials. The anode is maintained substantially axial Within the sleeving or hose during tube flexing by means of polystyrene spacer disks or an easily assembled polyethylene flexible cage assembly. The cathode is a wire spiraled on the outside of the counter. The sleeving or hose is fitted with glass end-pieces or any other good insulator to maintain the anode wire taut and to admit a counting gas mixture into the counter. Having the cathode wire on the outside of the counter substantially eliminates the objectional sheath effect of prior counters and permits counting rates up to 300,000 counts per minute. (AEC)

  14. Condensation nuclei measurement in the stratosphere for the NASA ACE program

    NASA Technical Reports Server (NTRS)

    Wilson, James Charles

    1994-01-01

    A condensation nucleus counter which operated at stratospheric pressures was developed, designed, and constructed. It was calibrated in the laboratory. Its response as a function of particle size and concentration was reported. This was the first time that the response of such an instrument was verified in the laboratory. An inlet was constructed which provided near isokinetic sampling. The resulting instrument, the U-2 CNC, was deployed on NASA U-2 aircraft in the study of the climatic effects of aerosol. These studies occurred in March, April, May, July, November, and December of 1992 and in April, May, June, and December of 1983. The U-2 CNC was used in the study of the aerosol cloud resulting from the eruption of El Chichon. It permitted the observation of new particle formation in the stratosphere.

  15. Countering Internet Extremism

    DTIC Science & Technology

    2009-01-01

    literally examine hundreds of books and speeches. Since the purpose of this work is examining ways to counter an extremist’s Internet use of the...provide differing perspectives on how to counter extremist Internet use . A 2008 New York Times article indirectly offers some methods. Writers Eric...or scholars have the most potential to effectively counter extremist Internet use . Such efforts could help to stifle some of the issues that

  16. Air Proportional Counter

    DOEpatents

    Simpson, Jr, J A

    1950-12-05

    A multiple wire counter utilizing air at atmospheric pressure as the ionizing medium and having a window of a nylon sheet of less than 0.5 mil thickness coated with graphite. The window is permeable to alpha particles so that the counter is well adapted to surveying sources of alpha radiation.

  17. An Inexpensive Radiation Counter.

    ERIC Educational Resources Information Center

    Holton, Brian; Balla, Zsolt

    1985-01-01

    Describes a radiation counter comparable to commercial units which costs less than $100. It consists of six sections: Geiger-Mueller tube and holder; high voltage supply; low voltage supply; pulse shaping circuit; "start/stop counts" gating circuit; and counter/display. List of materials needed and schematic diagrams are included. (JN)

  18. Proportional counter radiation camera

    DOEpatents

    Borkowski, C.J.; Kopp, M.K.

    1974-01-15

    A gas-filled proportional counter camera that images photon emitting sources is described. A two-dimensional, positionsensitive proportional multiwire counter is provided as the detector. The counter consists of a high- voltage anode screen sandwiched between orthogonally disposed planar arrays of multiple parallel strung, resistively coupled cathode wires. Two terminals from each of the cathode arrays are connected to separate timing circuitry to obtain separate X and Y coordinate signal values from pulse shape measurements to define the position of an event within the counter arrays which may be recorded by various means for data display. The counter is further provided with a linear drift field which effectively enlarges the active gas volume of the counter and constrains the recoil electrons produced from ionizing radiation entering the counter to drift perpendicularly toward the planar detection arrays. A collimator is interposed between a subject to be imaged and the counter to transmit only the radiation from the subject which has a perpendicular trajectory with respect to the planar cathode arrays of the detector. (Official Gazette)

  19. Samus Counter Lifting Fixture

    SciTech Connect

    Stredde, H.; /Fermilab

    1998-05-27

    A lifting fixture has been designed to handle the Samus counters. These counters are being removed from the D-zero area and will be transported off site for further use at another facility. This fixture is designed specifically for this particular application and will be transferred along with the counters. The future use of these counters may entail installation at a facility without access to a crane and therefore a lift fixture suitable for both crane and/or fork lift usage has been created The counters weigh approximately 3000 lbs. and have threaded rods extended through the counter at the top comers for lifting. When these counters were first handled/installed these rods were used in conjunction with appropriate slings and handled by crane. The rods are secured with nuts tightened against the face of the counter. The rod thread is M16 x 2({approx}.625-inch dia.) and extends 2-inch (on average) from the face of the counter. It is this cantilevered rod that the lift fixture engages with 'C' style plates at the four top comers. The strongback portion of the lift fixture is a steel rectangular tube 8-inch (vertical) x 4-inch x .25-inch wall, 130-inch long. 1.5-inch square bars are welded perpendicular to the long axis of the rectangular tube at the appropriate lift points and the 'C' plates are fastened to these bars with 3/4-10 high strength bolts -grade 8. Two short channel sections are positioned-welded-to the bottom of the rectangular tube on 40 feet centers, which are used as locators for fork lift tines. On the top are lifting eyes for sling/crane usage and are rated at 3500 lbs. safe working load each - vertical lift only.

  20. Cerenkov counters for high energy nuclei: Some new developments

    NASA Technical Reports Server (NTRS)

    Swordy, S. P.; Muller, D.

    1985-01-01

    A method to determine with gas Cerenkov counters the Lorentz factor, gamma = E/mc, of cosmic ray nuclei with high accuracy over the range gamma approx. 20 to 100 is discussed. The measurement of the Cerenkov emission angle theta, by use of a suitable imaging system is considered. Imaging counters, the ring imaging Cerenkov counters (RICH), were developed for use on accelerators. The image of off-axis particles to determine the amount of image distortion as a function of the direction of the incoming nucleus is examined and an acceptance solid angle, relative to the optical axis, within which the nucleus produces an image with an acceptable level of distortion is defined. The properties of the image, which becomes elliptical, for off-axis particles are analyzed.

  1. GASEOUS SCINTILLATION COUNTER

    DOEpatents

    Eggler, C.; Huddleston, C.M.

    1959-04-28

    A gaseous excitation counter for detecting the presence amd measuring the energy of subatomic particles and electromagnetic radiation is described. The counter includes a gas-tight chamber filled with an elemental gas capable of producing ultra-violet excitation quanta when irradiated with subatomic particles and electromagnetic radiation. The gas has less than one in a thousand parts ultra-violet absorbing contamination. When nuclear radiation ps present the ultra-violet light produced by the gas strikes a fluorescent material within the counter, responsive to produce visible excitation quanta, and photo-sensitive counting means detect the visible emission.

  2. Coincidence Proportional Counter

    DOEpatents

    Manley, J H

    1950-11-21

    A coincidence proportional counter having a plurality of collecting electrodes so disposed as to measure the range or energy spectrum of an ionizing particle-emitting source such as an alpha source, is disclosed.

  3. Portable multiplicity counter

    DOEpatents

    Newell, Matthew R.; Jones, David Carl

    2009-09-01

    A portable multiplicity counter has signal input circuitry, processing circuitry and a user/computer interface disposed in a housing. The processing circuitry, which can comprise a microcontroller integrated circuit operably coupled to shift register circuitry implemented in a field programmable gate array, is configured to be operable via the user/computer interface to count input signal pluses receivable at said signal input circuitry and record time correlations thereof in a total counting mode, coincidence counting mode and/or a multiplicity counting mode. The user/computer interface can be for example an LCD display/keypad and/or a USB interface. The counter can include a battery pack for powering the counter and low/high voltage power supplies for biasing external detectors so that the counter can be configured as a hand-held device for counting neutron events.

  4. Comparison of a designed virtual counter with a real counter

    NASA Astrophysics Data System (ADS)

    Tektas, G.; Celiktas, C.

    2017-02-01

    A counter is a device which counts the incident pulses within a fixed time. In this work, a virtual counter was designed by developing a code by LabVIEW software. Generator signals were sent to the virtual counter via a National Instruments multifunction data acquisition device. Analog and PFI (Programmable Function Interface) inputs of the device was used for the process. A real counter was also used for comparison. Counts acquired from both counters in different time intervals were compared with each other. It was concluded from the obtained results that the developed virtual counter could be used as a real counter.

  5. Counting Condensation Nuclei in the Antarctic Ozone Mission

    NASA Technical Reports Server (NTRS)

    Wilson, James Charles

    1994-01-01

    The work done on this grant primarily concerns the measurement of aerosol in the stratosphere from NASA ER-2 aircraft in studies of stratospheric ozone depletion in the northern and southern hemispheres. The ER-2 Condensation Nucleus Counter (CNC) measures the number concentration of particles in the diameter range of approximately 0.01 to 1 micron. The Passive Cavity Aerosol Spectrometer measures size distributions in the 0.17 to 3 micron diameter range. This instrument was upgraded during this grant period to a Focused Cavity Aerosol Spectrometer (FCAS). This upgrade permitted the instrument to measure particles as small as 0.05 micron in diameter. The inlet for the PCAS and FCAS was modified and characterized under this grant so that the modifications to the aerosol due to anisokinetic sampling and heating upon sampling and in transport to the measurement location were accounted for in the data analysis. These measurements permitted observations of particle production in the southern hemisphere winter polar vortex and observation of the impact of denitrification on the number concentration of the aerosol in the denitrified air. In the northern polar vortex, the measurements provided a characterization of the sulfate aerosol. Following the eruption of Mount Pinatubo in 1991, the measurements permitted an accurate characterization of the sulfate aerosol enhancements resulting from the eruption. This led to studies of the impact of heterogeneous chemistry on the partitioning of the partitioning of the reactive nitrogen species and the partitioning of the chlorine reservoir.

  6. Condensation nuclei and aerosol-scattering extinction measurements at Mauna Loa Observatory: 1974-1985. Data report

    SciTech Connect

    Massey, D.M.; Quakenbush, T.K.; Bodhaine, B.A.

    1987-07-01

    The observatory at Mauna Loa, Hawaii measures the characteristics of surface aerosols under background conditions. The instruments provide data that are representative of the background-aerosol climatology at Mauna Loa. These data can also be used to identify potential local contamination periods. The nephelometer's light-scattering measurements show an annual cycle: a maximum in April and a minimum in November, with a variation of a factor of 5.5. The Condensation Nucleus (CN) counter shows a much smaller annual cycle: a maximum in September and a minimum in March, with a variation of a factor of 1.5. A local decrease in CN concentration occurs in August. The Angstrom exponent minimum occurs in May. This indicates larger aerosol particles within the month as compared with the remainder of the year.

  7. Measurements of condensation nuclei in the Airborne Arctic Stratospheric Expedition - Observations of particle production in the polar vortex

    NASA Technical Reports Server (NTRS)

    Wilson, J. C.; Stolzenburg, M. R.; Clark, W. E.; Loewenstein, M.; Ferry, G. V.; Chan, K. R.

    1990-01-01

    The ER-2 Condensation Nucleus Counter (ER-2 CNC) was operated in the Airborne Arctic Stratospheric Expedition (AASE) in January and February 1989. The ER-2 CNC measures the mixing ratio of particles, CN, with diameters from approximately 0.02 to approximately 1 micron. The spatial distribution of CN in the Arctic polar vortex was found to resemble that measured in the Antarctic in the Spring of 1987. The vertical profile of CN in the vortex was lowered by subsidence. At altitudes above the minimum in the CN mixing ratio profile, CN mixing ratios correlated negatively with that of N2O, demonstrating new particle production. CN serve as nuclei in the formation of Polar Stratospheric Clouds (PSCs) and the concentration of CN can affect PSC properties.

  8. High energy nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Wosiek, B.

    1986-01-01

    Experimental results on high energy nucleus-nucleus interactions are presented. The data are discussed within the framework of standard super-position models and from the point-of-view of the possible formation of new states of matter in heavy ion collisions.

  9. Hydraulic drag at the condensing steam flow in tubes

    NASA Astrophysics Data System (ADS)

    Leontiev, A. I.; Milman, O. O.

    2014-12-01

    The dependency of condensing steam flow parameters in tubes and channels was studied as a function of different flow modes for the coolant: counter-flow, co-flow, cross-flow. The drop for the total pressure of steam is higher for the counter-flow than for the co-flow or cross-flow modes. The pressure drop was estimated with different computation models as a function flow mode. Calculation results were compared with experimental data.

  10. Compressor surge counter

    DOEpatents

    Castleberry, Kimberly N.

    1983-01-01

    A surge counter for a rotating compressor is provided which detects surging by monitoring the vibration signal from an accelerometer mounted on the shaft bearing of the compressor. The circuit detects a rapid increase in the amplitude envelope of the vibration signal, e.g., 4 dB or greater in less than one second, which is associated with a surge onset and increments a counter. The circuit is rendered non-responsive for a period of about 5 seconds following the detection which corresponds to the duration of the surge condition. This prevents multiple registration of counts during the surge period due to rapid swings in vibration amplitude during the period.

  11. Counter-propeller

    NASA Technical Reports Server (NTRS)

    De Caria, Ugo

    1931-01-01

    A counter-propeller is a fixed propeller smaller than the main propeller, mounted either fore or aft of the latter and performing the function of changing the direction of motion of the fluid filaments, which naturally tend to adopt a helicoidal form. This paper presents a consideration of the real advantage of counter-propellers on aircraft and the best shape of the blades. First, the author determines the possible energy absorption by the tangential increments. This process will be facilitated by the examination of the polygons of the relative velocities fore and aft of the generic section, of radius r, of one of the blades of the propeller.

  12. Electromagnetically Operated Counter

    DOEpatents

    Goldberg, H D; Goldberg, M I

    1951-12-18

    An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.

  13. Condensation model for the ESBWR passive condensers

    SciTech Connect

    Revankar, S. T.; Zhou, W.; Wolf, B.; Oh, S.

    2012-07-01

    In the General Electric's Economic simplified boiling water reactor (GE-ESBWR) the passive containment cooling system (PCCS) plays a major role in containment pressure control in case of an loss of coolant accident. The PCCS condenser must be able to remove sufficient energy from the reactor containment to prevent containment from exceeding its design pressure following a design basis accident. There are three PCCS condensation modes depending on the containment pressurization due to coolant discharge; complete condensation, cyclic venting and flow through mode. The present work reviews the models and presents model predictive capability along with comparison with existing data from separate effects test. The condensation models in thermal hydraulics code RELAP5 are also assessed to examine its application to various flow modes of condensation. The default model in the code predicts complete condensation well, and basically is Nusselt solution. The UCB model predicts through flow well. None of condensation model in RELAP5 predict complete condensation, cyclic venting, and through flow condensation consistently. New condensation correlations are given that accurately predict all three modes of PCCS condensation. (authors)

  14. The Third International Cloud Condensation Nuclei Workshop. [conference

    NASA Technical Reports Server (NTRS)

    Kocmond, W. C.; Rogers, C. R. (Editor); Rea, S. W. (Editor)

    1981-01-01

    Twenty-five instruments were tested, including size characterization devices and two Aitken counters. The test aerosols were supplied to the instruments by an on-line generation system, thereby eliminating the need for storage bags. Cloud condensation chambers and haze chambers are highlighted.

  15. Development of a thermal gradient cloud condensation nucleus spectrometer

    NASA Technical Reports Server (NTRS)

    Leu, Ming-Taun; Friedl, R.

    2004-01-01

    Droplet clouds are one of the most important factors controlling the albedo and hence the temperature of out planet. Anthropogenic aerosols, such as black carbon (BC) organic carbon (OC) and sulfate, have a strong influence on cloud albedo. IPCC (2001) has estimated the global mean forcing from aerosols to be potentially as large as that of green house gases but opposite in sign. However, the uncertainties associated with the indirect aerosol forcing preclude a quantitative estimate. An additional impact on the indirect aerosol forcing, not quantified by IPCC, arises from recently identified chemical factors, for examples, interactions of atmospheric soluble gases, slightly soluble solutes, and organic substance with aerosols, which may influence the formation of cloud droplets. Recent studies suggest that inclusion of chemical effects on aerosol droplets. We plan to conduct several critical laboratory experiments that will reduce the uncertainty associated with indirect radiative forcing due to chemical modification of sulfate and BC aerosols by ambient gases.

  16. Condensate Mixtures and Tunneling

    SciTech Connect

    Timmermans, E.

    1998-09-14

    The experimental study of condensate mixtures is a particularly exciting application of the recently developed atomic-trap Bose-Einstein condensate (BEC) technology: such multiple condensates represent the first laboratory systems of distinguishable boson superfluid mixtures. In addition, as the authors point out in this paper, the possibility of inter-condensate tunneling greatly enhances the richness of the condensate mixture physics. Not only does tunneling give rise to the oscillating particle currents between condensates of different chemical potentials, such as those studied extensively in the condensed matter Josephson junction experiments, it also affects the near-equilibrium dynamics and stability of the condensate mixtures. In particular, the stabilizing influence of tunneling with respect to spatial separation (phase separation) could be of considerable practical importance to the atomic trap systems. Furthermore, the creation of mixtures of atomic and molecular condensates could introduce a novel type of tunneling process, involving the conversion of a pair of atomic condensate bosons into a single molecular condensate boson. The static description of condensate mixtures with such type of pair tunneling suggests the possibility of observing dilute condensates with the liquid-like property of a self-determined density.

  17. Countering antivaccination attitudes

    PubMed Central

    Horne, Zachary; Powell, Derek; Hummel, John E.; Holyoak, Keith J.

    2015-01-01

    Three times as many cases of measles were reported in the United States in 2014 as in 2013. The reemergence of measles has been linked to a dangerous trend: parents refusing vaccinations for their children. Efforts have been made to counter people’s antivaccination attitudes by providing scientific evidence refuting vaccination myths, but these interventions have proven ineffective. This study shows that highlighting factual information about the dangers of communicable diseases can positively impact people’s attitudes to vaccination. This method outperformed alternative interventions aimed at undercutting vaccination myths. PMID:26240325

  18. Condensates in Jovian Atmospheres

    NASA Technical Reports Server (NTRS)

    West, R.

    1999-01-01

    Thermochemical equilibrium theory which starts with temperature/pressure profiles, compositional information and thermodynamic data for condensable species in the jovian planet atmospheres predicts layers of condensate clouds in the upper troposphere.

  19. Low latency counter event indication

    DOEpatents

    Gara, Alan G.; Salapura, Valentina

    2010-08-24

    A hybrid counter array device for counting events with interrupt indication includes a first counter portion comprising N counter devices, each for counting signals representing event occurrences and providing a first count value representing lower order bits. An overflow bit device associated with each respective counter device is additionally set in response to an overflow condition. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits. An operatively coupled control device monitors each associated overflow bit device and initiates incrementing a second count value stored at a corresponding memory location in response to a respective overflow bit being set. The incremented second count value is compared to an interrupt threshold value stored in a threshold register, and, when the second counter value is equal to the interrupt threshold value, a corresponding "interrupt arm" bit is set to enable a fast interrupt indication. On a subsequent roll-over of the lower bits of that counter, the interrupt will be fired.

  20. Low latency counter event indication

    DOEpatents

    Gara, Alan G.; Salapura, Valentina

    2008-09-16

    A hybrid counter array device for counting events with interrupt indication includes a first counter portion comprising N counter devices, each for counting signals representing event occurrences and providing a first count value representing lower order bits. An overflow bit device associated with each respective counter device is additionally set in response to an overflow condition. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits. An operatively coupled control device monitors each associated overflow bit device and initiates incrementing a second count value stored at a corresponding memory location in response to a respective overflow bit being set. The incremented second count value is compared to an interrupt threshold value stored in a threshold register, and, when the second counter value is equal to the interrupt threshold value, a corresponding "interrupt arm" bit is set to enable a fast interrupt indication. On a subsequent roll-over of the lower bits of that counter, the interrupt will be fired.

  1. Space and power efficient hybrid counters array

    DOEpatents

    Gara, Alan G.; Salapura, Valentina

    2010-03-30

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  2. Space and power efficient hybrid counters array

    DOEpatents

    Gara, Alan G.; Salapura, Valentina

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  3. The microstrip proportional counter

    NASA Technical Reports Server (NTRS)

    Ramsey, B. D.

    1992-01-01

    Microstrip detectors in which the usual discrete anode and cathode wires are replaced by conducting strips on an insulating or partially insulating substrate are fabricated using integrated circuit-type photolithographic techniques and hence offer very high spatial accuracy and uniformity, together with the capability of producing extremely fine electrode structures. Microstrip proportional counters have now been variously reported having an energy resolution of better than 11 percent FWHM at 5.9 keV. They have been fabricated with anode bars down to 2 microns and on a variety of substrate materials including thin films which can be molded to different shapes. This review will examine the development of the microstrip detector with emphasis on the qualities which make this detector particularly interesting for use in astronomy.

  4. [The perichromatin compartment of the cell nucleus].

    PubMed

    Bogoliubov, D S

    2014-01-01

    In this review, the data on the structure and composition of the perichromatin compartment, a special border area between the condensed chromatin and the interchromatin space of the cell nucleus, are discussed in the light of the concept of nuclear functions in complex nuclear architectonics. Morphological features, molecular composition and functions of main extrachromosomal structures of the perichromatin compartment, perichromatin fibrils (PFs) and perichromatin granules (PGs) including nuclear stress-bodies (nSBs) that are derivates of the PGs under heat shock, are presented. A special attention was paid to the features of the molecular compositions of PFs and PGs in different cell types and at different physiological conditions.

  5. Over-the-Counter Medicines

    MedlinePlus

    Over-the-counter (OTC) medicines are drugs you can buy without a prescription. Some OTC medicines relieve aches, pains and itches. Some prevent or cure ... the Food and Drug Administration decides whether a medicine is safe enough to sell over-the-counter. ...

  6. Counter-Learning under Oppression

    ERIC Educational Resources Information Center

    Kucukaydin, Ilhan

    2010-01-01

    This qualitative study utilized the method of narrative analysis to explore the counter-learning process of an oppressed Kurdish woman from Turkey. Critical constructivism was utilized to analyze counter-learning; Frankfurt School-based Marcusian critical theory was used to analyze the sociopolitical context and its impact on the oppressed. Key…

  7. Cloud condensation nuclei over the Arctic Ocean in early spring

    SciTech Connect

    Hegg, D.A.; Ferek, R.J.; Hobbs, P.V.

    1995-09-01

    Cloud condensation nucleus (CCN) spectral data are presented for the Arctic in spring, which considerably augment the existing meager CCN database for the Arctic. Concurrent measurements of sulfate mass suggest that most of the CCN were commonly not sulfate. Sulfate was more closely associated with particles below the CCN size range. Some measurements of the microphysical structure of Arctic Stratus clouds are also described.

  8. The Nucleus Introduced

    PubMed Central

    Pederson, Thoru

    2011-01-01

    Now is an opportune moment to address the confluence of cell biological form and function that is the nucleus. Its arrival is especially timely because the recognition that the nucleus is extremely dynamic has now been solidly established as a paradigm shift over the past two decades, and also because we now see on the horizon numerous ways in which organization itself, including gene location and possibly self-organizing bodies, underlies nuclear functions. PMID:20660024

  9. High resolution time interval counter

    NASA Technical Reports Server (NTRS)

    Zhang, Victor S.; Davis, Dick D.; Lombardi, Michael A.

    1995-01-01

    In recent years, we have developed two types of high resolution, multi-channel time interval counters. In the NIST two-way time transfer MODEM application, the counter is designed for operating primarily in the interrupt-driven mode, with 3 start channels and 3 stop channels. The intended start and stop signals are 1 PPS, although other frequencies can also be applied to start and stop the count. The time interval counters used in the NIST Frequency Measurement and Analysis System are implemented with 7 start channels and 7 stop channels. Four of the 7 start channels are devoted to the frequencies of 1 MHz, 5 MHz or 10 MHz, while triggering signals to all other start and stop channels can range from 1 PPS to 100 kHz. Time interval interpolation plays a key role in achieving the high resolution time interval measurements for both counters. With a 10 MHz time base, both counters demonstrate a single-shot resolution of better than 40 ps, and a stability of better than 5 x 10(exp -12) (sigma(sub chi)(tau)) after self test of 1000 seconds). The maximum rate of time interval measurements (with no dead time) is 1.0 kHz for the counter used in the MODEM application and is 2.0 kHz for the counter used in the Frequency Measurement and Analysis System. The counters are implemented as plug-in units for an AT-compatible personal computer. This configuration provides an efficient way of using a computer not only to control and operate the counters, but also to store and process measured data.

  10. Oscillatory counter-centrifugation

    NASA Astrophysics Data System (ADS)

    Xu, Shujing; Nadim, Ali

    2016-02-01

    In ordinary centrifugation, a suspended particle that is heavier than the displaced fluid migrates away from the rotation axis when the fluid-filled container rotates steadily about that axis. In contrast a particle that is lighter than the displaced fluid (e.g., a bubble) migrates toward the rotation axis in a centrifuge. In this paper, we show theoretically that if a fluid-filled container rotates in an oscillatory manner as a rigid body about an axis, at high enough oscillation frequencies, the sense of migration of suspended particles is reversed. That is, in that case particles denser than the fluid migrate inward, while those that are lighter than the fluid move outward. We term this unusual phenomenon "Oscillatory Counter-Centrifugation" or OCC, for short. Through application of the method of averaging to the equations of motion, we derive a simple criterion to predict the occurrence of OCC. The analysis also reveals that the time-average of the Coriolis force in the radial direction is the term that is responsible for this effect. In addition, we analyze the effects of the Basset history force and the Rubinow-Keller lift force on particle trajectories and find that OCC persists even when these forces are active. The phenomenon awaits experimental verification.

  11. EPRI condensate polisher guidelines

    SciTech Connect

    Larkin, B.A.; Webb, L.C.; Sawochka, S.G.; Crits, G.J.; Pocock, F.J.; Wirth, L.

    1995-01-01

    Cycle chemistry is one of the most important contributors to the loss of availability of generating units. Condensate polishing can significantly improve cycle chemistry by improving cycle water quality and minimizing the transport of contaminants in the power cycle. The EPRI-funded project described in this paper developed comprehensive guidelines for condensate polishing based upon information gathered from utility surveys, equipment vendors, and resin suppliers. Existing literature was also surveyed for pertinent input. Comprehensive guidelines which outline guidance for design, operation, maintenance, surveillance, management, and retrofitting of condensate polishing systems were developed. Economics of condensate polishing were evaluated and a roadmap for economic evaluation for utilities to follow was produced.

  12. Multiple channel programmable coincidence counter

    DOEpatents

    Arnone, Gaetano J.

    1990-01-01

    A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the seralizer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

  13. Measure Guideline: Evaporative Condensers

    SciTech Connect

    German, A; Dakin, B.; Hoeschele, M.

    2012-03-01

    This measure guideline on evaporative condensers provides information on properly designing, installing, and maintaining evaporative condenser systems as well as understanding the benefits, costs, and tradeoffs. This is a prescriptive approach that outlines selection criteria, design and installation procedures, and operation and maintenance best practices.

  14. Cloud condensation nuclei near marine cumulus

    NASA Technical Reports Server (NTRS)

    Hudson, James G.

    1993-01-01

    Extensive airborne measurements of cloud condensation nucleus (CCN) spectra and condensation nuclei below, in, between, and above the cumulus clouds near Hawaii point to important aerosol-cloud interactions. Consistent particle concentrations of 200/cu cm were found above the marine boundary layer and within the noncloudy marine boundary layer. Lower and more variable CCN concentrations within the cloudy boundary layer, especially very close to the clouds, appear to be a result of cloud scavenging processes. Gravitational coagulation of cloud droplets may be the principal cause of this difference in the vertical distribution of CCN. The results suggest a reservoir of CCN in the free troposphere which can act as a source for the marine boundary layer.

  15. Large magnetic storage ring for Bose-Einstein condensates

    SciTech Connect

    Arnold, A. S.; Garvie, C. S.; Riis, E.

    2006-04-15

    Cold atomic clouds and Bose-Einstein condensates have been stored in a 10 cm diameter vertically oriented magnetic ring. An azimuthal magnetic field enables low-loss propagation of atomic clouds over a total distance of 2 m, with a heating rate of less than 50 nK/s. The vertical geometry was used to split an atomic cloud into two counter-rotating clouds which were recombined after one revolution. The system will be ideal for studying condensate collisions and ultimately Sagnac interferometry.

  16. Geothermal steam condensate reinjection

    NASA Technical Reports Server (NTRS)

    Chasteen, A. J.

    1974-01-01

    Geothermal electric generating plants which use condensing turbines and generate and excess of condensed steam which must be disposed of are discussed. At the Geysers, California, the largest geothermal development in the world, this steam condensate has been reinjected into the steam reservoir since 1968. A total of 3,150,000,000 gallons of steam condensate has been reinjected since that time with no noticeable effect on the adjacent producing wells. Currently, 3,700,000 gallons/day from 412 MW of installed capacity are being injected into 5 wells. Reinjection has also proven to be a satisfactory method of disposing of geothermal condensate a Imperial Valley, California, and at the Valles Caldera, New Mexico.

  17. Kaon-nucleus scattering

    NASA Technical Reports Server (NTRS)

    Hong, Byungsik; Maung, Khin Maung; Wilson, John W.; Buck, Warren W.

    1989-01-01

    The derivations of the Lippmann-Schwinger equation and Watson multiple scattering are given. A simple optical potential is found to be the first term of that series. The number density distribution models of the nucleus, harmonic well, and Woods-Saxon are used without t-matrix taken from the scattering experiments. The parameterized two-body inputs, which are kaon-nucleon total cross sections, elastic slope parameters, and the ratio of the real to the imaginary part of the forward elastic scattering amplitude, are presented. The eikonal approximation was chosen as our solution method to estimate the total and absorptive cross sections for the kaon-nucleus scattering.

  18. Kaon-nucleus scattering

    NASA Technical Reports Server (NTRS)

    Hong, Byungsik; Buck, Warren W.; Maung, Khin M.

    1989-01-01

    Two kinds of number density distributions of the nucleus, harmonic well and Woods-Saxon models, are used with the t-matrix that is taken from the scattering experiments to find a simple optical potential. The parameterized two body inputs, which are kaon-nucleon total cross sections, elastic slope parameters, and the ratio of the real to imaginary part of the forward elastic scattering amplitude, are shown. The eikonal approximation was chosen as the solution method to estimate the total and absorptive cross sections for the kaon-nucleus scattering.

  19. A multi-field approach to DNA condensation

    NASA Astrophysics Data System (ADS)

    Ran, Shi-Yong; Jia, Jun-Li

    2015-12-01

    DNA condensation is an important process in many fields including life sciences, polymer physics, and applied technology. In the nucleus, DNA is condensed into chromosomes. In polymer physics, DNA is treated as a semi-flexible molecule and a polyelectrolyte. Many agents, including multi-valent cations, surfactants, and neutral poor solvents, can cause DNA condensation, also referred to as coil-globule transition. Moreover, DNA condensation has been used for extraction and gene delivery in applied technology. Many physical theories have been presented to elucidate the mechanism underlying DNA condensation, including the counterion correlation theory, the electrostatic zipper theory, and the hydration force theory. Recently several single-molecule studies have focused on DNA condensation, shedding new light on old concepts. In this document, the multi-field concepts and theories related to DNA condensation are introduced and clarified as well as the advances and considerations of single-molecule DNA condensation experiments are introduced. Project supported by the National Natural Science Foundation of China (Grant Nos. 21204065 and 20934004) and the Natural Science Foundation of Zhejiang Province, China (Grant No. Y4110357).

  20. Capillary condensation as a morphological transition.

    PubMed

    Kornev, Konstantin G; Shingareva, Inna K; Neimark, Alexander V

    2002-02-25

    The process of capillary condensation/evaporation in cylindrical pores is considered within the idea of symmetry breaking. Capillary condensation/evaporation is treated as a morphological transition between the wetting film configurations of different symmetry. We considered two models: (i) the classical Laplace theory of capillarity and (ii) the Derjaguin model which takes into account the surface forces expressed in terms of the disjoining pressure. Following the idea of Everett and Haynes, the problem of condensation/evaporation is considered as a transition from bumps/undulations to lenses. Using the method of phase portraits, we discuss the mathematical mechanisms of this transition hidden in the Laplace and Derjaguin equations. Analyzing the energetic barriers of the bump and lens formation, it is shown that the bump formation is a prerogative of capillary condensation: for the vapor-liquid transition in a pore, the bump plays the same role as the spherical nucleus in a bulk fluid. We show also that the Derjaguin model admits a variety of interfacial configurations responsible for film patterning at specific conditions.

  1. Experimental Investigation of Flow Condensation in Microgravity

    NASA Technical Reports Server (NTRS)

    Lee, Hyoungsoon; Park, Ilchung; Konishi, Christopher; Mudawar, Issam; May, Rochelle I.; Juergens, Jeffery R.; Wagner, James D.; Hall, Nancy R.; Nahra, Henry K.; Hasan, Mohammed M.; Mackey, Jeffery R.

    2013-01-01

    Future manned missions to Mars are expected to greatly increase the space vehicle's size, weight, and heat dissipation requirements. An effective means to reducing both size and weight is to replace single-phase thermal management systems with two-phase counterparts that capitalize upon both latent and sensible heat of the coolant rather than sensible heat alone. This shift is expected to yield orders of magnitude enhancements in flow boiling and condensation heat transfer coefficients. A major challenge to this shift is a lack of reliable tools for accurate prediction of two-phase pressure drop and heat transfer coefficient in reduced gravity. Developing such tools will require a sophisticated experimental facility to enable investigators to perform both flow boiling and condensation experiments in microgravity in pursuit of reliable databases. This study will discuss the development of the Flow Boiling and Condensation Experiment (FBCE) for the International Space Station (ISS), which was initiated in 2012 in collaboration between Purdue University and NASA Glenn Research Center. This facility was recently tested in parabolic flight to acquire condensation data for FC-72 in microgravity, aided by high-speed video analysis of interfacial structure of the condensation film. The condensation is achieved by rejecting heat to a counter flow of water, and experiments were performed at different mass velocities of FC-72 and water and different FC-72 inlet qualities. It is shown that the film flow varies from smooth-laminar to wavy-laminar and ultimately turbulent with increasing FC-72 mass velocity. The heat transfer coefficient is highest near the inlet of the condensation tube, where the film is thinnest, and decreases monotonically along the tube, except for high FC-72 mass velocities, where the heat transfer coefficient is enhanced downstream. This enhancement is attributed to both turbulence and increased interfacial waviness. One-ge correlations are shown to

  2. Sedimentary condensation and authigenesis

    NASA Astrophysics Data System (ADS)

    Föllmi, Karl

    2016-04-01

    Most marine authigenic minerals form in sediments, which are subjected to condensation. Condensation processes lead to the formation of well individualized, extremely thin (< 1m) beds, which were accumulated during extremely long time periods (> 100ky), and which experienced authigenesis and the precipitation of glaucony, verdine, phosphate, iron and manganese oxyhydroxides, iron sulfide, carbonate and/or silica. They usually show complex internal stratigraphies, which result from an interplay of sediment accumulation, halts in sedimentation, sediment winnowing, erosion, reworking and bypass. They may include amalgamated faunas of different origin and age. Hardgrounds may be part of condensed beds and may embody strongly condensed beds by themselves. Sedimentary condensation is the result of a hydrodynamically active depositional regime, in which sediment accumulation, winnowing, erosion, reworking and bypass are processes, which alternate as a function of changes in the location and intensity of currents, and/or as the result of episodic high-energy events engendered by storms and gravity flow. Sedimentary condensation has been and still is a widespread phenomenon in past and present-day oceans. The present-day distribution of glaucony and verdine-rich sediments on shelves and upper slopes, phosphate-rich sediments and phosphorite on outer shelves and upper slopes, ferromanganese crusts on slopes, seamounts and submarine plateaus, and ferromanganese nodules on abyssal seafloors is a good indication of the importance of condensation processes today. In the past, we may add the occurrence of oolitic ironstone, carbonate hardgrounds, and eventually also silica layers in banded iron formations as indicators of the importance of condensation processes. Besides their economic value, condensed sediments are useful both as a carrier of geochemical proxies of paleoceanographic and paleoenvironmental change, as well as the product of episodes of paleoceanographic and

  3. Onset of deconfinement in nucleus-nucleus collisions

    SciTech Connect

    Gazdzicki, M.; Gorenstein, M. I.; Seyboth, P.

    2012-05-15

    The energy dependence of hadron production in relativistic nucleus-nucleus collisions reveals anomalies-the kink, horn, and step. They were predicted as signals of the deconfinement phase transition and observed by the NA49 Collaboration in central PbPb collisions at the CERN SPS. This indicates the onset of the deconfinement in nucleus-nucleus collisions at about 30 A GeV.

  4. Electrolyte vapor condenser

    DOEpatents

    Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.

    1983-02-08

    A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.

  5. Condensation of chondrules

    NASA Technical Reports Server (NTRS)

    Blander, M.

    1983-01-01

    Analysis of current experimental results concerned with the kinetic constraints on chondrule formation showed that the major physical properties of chondrules could have been produced by direct condensation of metastable liquid silicates droplets from a hot gas in the primordial nebula. It is argued that such a condensation process would have to be followed by crystallization, accretion, and partial comminution of the droplets. The chemical mechanisms driving this process are described, including: nucleation constraints on comminution and crystallization; slow transformations and chemical reactions in chain silicates; and the slow diffusion of ions. It is shown that the physical mechanisms for chondrule condensation are applicable to a broad spectrum of chondrule sources.

  6. Pyrochemical neutron multiplicity counter design

    SciTech Connect

    Langner, D.G.; Ensslin, N.; Krick, M.S.

    1990-01-01

    Pyrochemical process materials are difficult to measure using conventional neutron counting methods because of significant self- multiplication and variable ({alpha},n) reaction rates. Multiplicity counters measure the first three moments of the neutron multiplicity distribution and thus make it possible to determine sample mass even when multiplication and ({alpha},n) rate are unknown. A new multiplicity counter suitable for inplant measurement of pyrochemical process materials has been designed using Monte Carlo simulations. The goals were to produce a counter that has high neutron detection efficiency, low die-away time, a flat spatial efficiency profile, and is insensitive to the neutron energy spectrum. Monte Carlo calculations were performed for several prototype models consisting of four rings of 71-cm active length {sup 3}He tubes in a polyethylene body. The cadmium-lined sample well is 25 cm in diameter to accommodate a wide variety of inplant sample containers. The counter can be free-standing or in-line without mechanical modification. The calculations were performed to determine the above design criteria for several configurations of tube spacing, cadmium liners, and sample height. Calculations were also performed for distributed sample sources to understand the integrated effects of variable neutron spectra on the counter. 5 refs., 8 figs., 1 tab.

  7. Key condenser failure mechanisms

    SciTech Connect

    Buecker, B.

    2009-04-15

    Eight practical lessons highlight many of the factors that can influence condenser tube corrosion at coal-fired utilities and the effects contaminant in-leakage can have on steam generating units. 1 ref., 4 figs.

  8. Measure Guideline: Evaporative Condensers

    SciTech Connect

    German, A.; Dakin, B.; Hoeschele, M.

    2012-03-01

    The purpose of this measure guideline on evaporative condensers is to provide information on a cost-effective solution for energy and demand savings in homes with cooling loads. This is a prescriptive approach that outlines selection criteria, design and installation procedures, and operation and maintenance best practices. This document has been prepared to provide a process for properly designing, installing, and maintaining evaporative condenser systems as well as understanding the benefits, costs, and tradeoffs.

  9. Molecular equilibrium with condensation

    NASA Astrophysics Data System (ADS)

    Sharp, C. M.; Huebner, W. F.

    1990-02-01

    Minimization of the Gibbs energy of formation for species of chemical elements and compounds in their gas and condensed phases determines their relative abundances in a mixture in chemical equilibrium. The procedure is more general and more powerful than previous abundance determinations in multiphase astrophysical mixtures. Some results for astrophysical equations of state are presented, and the effects of condensation on opacity are briefly indicated.

  10. Condensate dark matter stars

    SciTech Connect

    Li, X.Y.; Harko, T.; Cheng, K.S. E-mail: harko@hkucc.hku.hk

    2012-06-01

    We investigate the structure and stability properties of compact astrophysical objects that may be formed from the Bose-Einstein condensation of dark matter. Once the critical temperature of a boson gas is less than the critical temperature, a Bose-Einstein Condensation process can always take place during the cosmic history of the universe. Therefore we model the dark matter inside the star as a Bose-Einstein condensate. In the condensate dark matter star model, the dark matter equation of state can be described by a polytropic equation of state, with polytropic index equal to one. We derive the basic general relativistic equations describing the equilibrium structure of the condensate dark matter star with spherically symmetric static geometry. The structure equations of the condensate dark matter stars are studied numerically. The critical mass and radius of the dark matter star are given by M{sub crit} ≈ 2(l{sub a}/1fm){sup 1/2}(m{sub χ}/1 GeV){sup −3/2}M{sub s}un and R{sub crit} ≈ 1.1 × 10{sup 6}(l{sub a}/1 fm){sup 1/2}(m{sub χ}/1 GeV){sup −3/2} cm respectively, where l{sub a} and m{sub χ} are the scattering length and the mass of dark matter particle, respectively.

  11. Condensed Matter Nuclear Science

    NASA Astrophysics Data System (ADS)

    Takahashi, Akito; Ota, Ken-Ichiro; Iwamura, Yashuhiro

    wave function near surface of palladium lattice / X. Z. Li ... [et al.]. Theoretical comparison between semi-classical and quantum tunneling effect / F. Frisone. New cooperative mechanisms of low-energy nuclear reactions using super low-energy external field / F. A. Gareev and I. E. Zhidkova. Polyneutron theory of transmutation / J. C. Fisher. The thermal conduction from the centers of the nuclear reactions in solids / K.-I. Tsuchiya. Four-body RST general nuclear wavefunctions and matrix elements / I. Chaudhary and P. L. Hagelstein. Study on formation of tetrahedral or octahedral symmetric condensation by hopping of alkali or alkaline-earth metal ion / H. Miura. Calculations of nuclear reactions probability in a crystal lattice of lanthanum deuteride / V. A. Kirkinskii and Yu. A. Novikov. Possible coupled electron and electron neutrino in nucleus and its physical catalysis effect on D-D cold fusion into helium in Pd / M. Fukuhara. Tunnel resonance of electron wave and force of fluctuation / M. Ban. Types of nuclear fusion in solids / N. Yabuuchi. Neutrino-dineutron reactions (low-energy nuclear reactions induced by D[symbol] gas permeation through Pd complexes - Y. Iwamura effect) / V. Muromtsev, V. Platonov and I. Savvatimova. An explanation of earthquakes by the blacklight process and hydrogen fusion / H. Yamamoto. Theoretical modeling of electron flow action on probability of nuclear fusion of deuterons / A. I. Goncharov and V. A. Kirkinskii.

  12. The Eros of Counter Education

    ERIC Educational Resources Information Center

    Luzon, Pinhas

    2016-01-01

    Erotic Counter Education (ECE) is the educational position of the late Ilan Gur-Ze'ev. In ECE Gur-Ze'ev combines two opposing positions in the philosophy of education, one teleological and anti-utopian, the other teleological and utopian. In light of this unique combination, I ask what mediates between these two poles and suggest that the answer…

  13. High resolution time interval counter

    DOEpatents

    Condreva, K.J.

    1994-07-26

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured. 3 figs.

  14. High resolution time interval counter

    DOEpatents

    Condreva, Kenneth J.

    1994-01-01

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.

  15. Particles from a Diesel ship engine: Mixing state on the nano scale and cloud condensation abilities

    NASA Astrophysics Data System (ADS)

    Lieke, K. I.; Rosenørn, T.; Fuglsang, K.; Frederiksen, T.; Butcher, A. C.; King, S. M.; Bilde, M.

    2012-04-01

    Transport by ship plays an important role in global logistics. Current international policy initiatives by the International Maritime Organization (IMO) are taken to reduce emissions from ship propulsion systems (NO and SO, primarily). However, particulate emissions (e.g. soot) from ships are yet not regulated by legislations. To date, there is still a lack of knowledge regarding the global and local effects of the particulate matter emitted from ships at sea. Particles may influence the climate through their direct effects (scattering and absorption of long and shortwave radiation) and indirectly through formation of clouds. Many studies have been carried out estimating the mass and particle number from ship emissions (e.g. Petzold et al. 2008), many of them in test rig studies (e.g. Kasper et al. 2007). It is shown that particulate emissions vary with engine load and chemical composition of fuels. Only a few studies have been carried out to characterize the chemical composition and cloud-nucleating ability of the particulate matter (e.g. Corbett et al. 1997). In most cases, the cloud-nucleating ability of emission particles is estimated from number size distribution. We applied measurements to characterize particulate emissions from a MAN B&W Low Speed engine on test bed. A unique data set was obtained through the use of a scanning mobility particle sizing system (SMPS), combined with a cloud condensation nucleus (CCN) counter and a thermodenuder - all behind a dilution system. In addition, impactor samples were taken on nickel grids with carbon foil for use in an electron microscope (EM) to characterize the mineral phase and mixing state of the particles. The engine was operated at a series of different load conditions and an exhaust gas recirculation (EGR) system was applied. Measurements were carried out before and after the EGR system respectively. Our observations show significant changes in number size distribution and CCN activity with varying conditions

  16. Formation of mammalian erythrocytes: chromatin condensation and enucleation.

    PubMed

    Ji, Peng; Murata-Hori, Maki; Lodish, Harvey F

    2011-07-01

    In all vertebrates, the cell nucleus becomes highly condensed and transcriptionally inactive during the final stages of red cell biogenesis. Enucleation, the process by which the nucleus is extruded by budding off from the erythroblast, is unique to mammals. Enucleation has critical physiological and evolutionary significance in that it allows an elevation of hemoglobin levels in the blood and also gives red cells their flexible biconcave shape. Recent experiments reveal that enucleation involves multiple molecular and cellular pathways that include histone deacetylation, actin polymerization, cytokinesis, cell-matrix interactions, specific microRNAs and vesicle trafficking; many evolutionarily conserved proteins and genes have been recruited to participate in this uniquely mammalian process. In this review, we discuss recent advances in mammalian erythroblast chromatin condensation and enucleation, and conclude with our perspectives on future studies.

  17. Basic Research Needs for Countering Terrorism

    SciTech Connect

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  18. Neutrino-nucleus interactions

    SciTech Connect

    Gallagher, H.; Garvey, G.; Zeller, G.P.; /Fermilab

    2011-01-01

    The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.

  19. Reality of comet nucleus.

    NASA Technical Reports Server (NTRS)

    Lyttleton, R. A.

    1972-01-01

    The prime problem of a comet mission must be to settle whether the cometary nucleus has an actual tangible material existence, or whether it arises from some optical effect present only at times within comets. The absence of any large particles in a comet seems to be demonstrated by certain meteor showers. A feature that would seem to indicate that a comet consists primarily of a swarm of particles is that the coma in general contracts as the comet approaches the sun, roughly in proportion within the distance, and then expands again as it recedes.

  20. Nucleus from string theory

    NASA Astrophysics Data System (ADS)

    Hashimoto, Koji; Morita, Takeshi

    2011-08-01

    In generic holographic QCD, we find that baryons are bound to form a nucleus, and that its radius obeys the empirically-known mass-number (A) dependence r∝A1/3 for large A. Our result is robust, since we use only a generic property of D-brane actions in string theory. We also show that nucleons are bound completely in a finite volume. Furthermore, employing a concrete holographic model (derived by Hashimoto, Iizuka, and Yi, describing a multibaryon system in the Sakai-Sugimoto model), the nuclear radius is evaluated as O(1)×A1/3[fm], which is consistent with experiments.

  1. Lossy Counter Machines Decidability Cheat Sheet

    NASA Astrophysics Data System (ADS)

    Schnoebelen, Philippe

    Lossy counter machines (LCM's) are a variant of Minsky counter machines based on weak (or unreliable) counters in the sense that they can decrease nondeterministically and without notification. This model, introduced by R. Mayr [TCS 297:337-354 (2003)], is not yet very well known, even though it has already proven useful for establishing hardness results.

  2. Science Experimenter: Experimenting with a Geiger Counter.

    ERIC Educational Resources Information Center

    Mims, Forrest M., III

    1992-01-01

    Describes the use of geiger counters for scientific investigations and experiments. Presents information about background radiation, its sources and detection. Describes how geiger counters work and other methods of radiation detection. Provides purchasing information for geiger counters, related computer software and equipment. (MCO)

  3. Keeping condensers clean

    SciTech Connect

    Wicker, K.

    2006-04-15

    The humble condenser is among the biggest contributors to a steam power plant's efficiency. But although a clean condenser can provide great economic benefit, a dirty one can raise plant heat rate, resulting in large losses of generation revenue and/or unnecessarily high fuel bills. Conventional methods for cleaning fouled tubes range form chemicals to scrapers to brushes and hydro-blasters. This article compares the available options and describes how one power station, Omaha Public Power District's 600 MW North Omaha coal-fired power station, cleaned up its act. The makeup and cooling water of all its five units comes from the Missouri River. 6 figs.

  4. Higgs-boson production in nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Norbury, J. W.; Townsend, L. W. (Principal Investigator)

    1990-01-01

    Cross-section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two-photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two-photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

  5. Higgs-Boson Production in Nucleus-Nucleus Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    1992-01-01

    Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

  6. Networking the nucleus

    PubMed Central

    Rajapakse, Indika; Scalzo, David; Tapscott, Stephen J; Kosak, Steven T; Groudine, Mark

    2010-01-01

    The nuclei of differentiating cells exhibit several fundamental principles of self-organization. They are composed of many dynamical units connected physically and functionally to each other—a complex network—and the different parts of the system are mutually adapted and produce a characteristic end state. A unique cell-specific signature emerges over time from complex interactions among constituent elements that delineate coordinate gene expression and chromosome topology. Each element itself consists of many interacting components, all dynamical in nature. Self-organizing systems can be simplified while retaining complex information using approaches that examine the relationship between elements, such as spatial relationships and transcriptional information. These relationships can be represented using well-defined networks. We hypothesize that during the process of differentiation, networks within the cell nucleus rewire according to simple rules, from which a higher level of order emerges. Studying the interaction within and among networks provides a useful framework for investigating the complex organization and dynamic function of the nucleus. PMID:20664641

  7. Condensed Matter Theories - Volume 22

    NASA Astrophysics Data System (ADS)

    Reinholz, Heidi; Röpke, Gerd; de Llano, Manuel

    2007-09-01

    . Arikawa. Frustrated quantum antiferromagnets: application of high-order coupled cluster method / J. Richter ... [et al.]. Vorticity and antivorticity in submicron ferromagnetic films / H. Wang, M. Yan and C.E. Campbell -- pt. E. Conductivity. D-wave checkerboard bose condensate of mobile bipolarons / A.S. Alexandrov. Five possible reasons why high-Tc superconductivity is stalled / M. Grether and M. de Llano. Multistability and Multi 2[Pie symbol]-Kinks in the Frenkel-Kontorova model: an application to arrays of Josephson junctions / K.E. Kürten and C. Krattenthaler. Lowering of Boson-Fermion system energy with a gapped cooper resonant-pair dispersion relation / T.A. Mamedov and M. de Llano. The concept of correlated density and its application / K. Morawetz ... [et al.]. Competing local and non-local phase correlations in Fermionic systems with resonant pairing: the Boson-Fermion scenario / J. Ranninger. Superconducting order parameters in the extended Hubbard model: a simple mean-field study / J.S. Thakur and M.P. Das -- pt. F. Nuclear systems. Distribution of maxima of the antisymmetized wave function for the nucleons of a closed-shell and for the nucleons of all closed-shells in a nucleus / G.S. Anagnostatos. Pairing of strongly correlated nucleons / W.H. Dickhoff. Short range correlations in relativistic nuclear models / P.K. Panda, C. Providência and J. da Providência. Quartetting in attractive Fermi-systems and alpha particle condensation in nuclear systems / P. Schuck ... [et al.]. Alpha-alpha and Alpha-nucleus potentials: an energy-density fucntional approach / Z.F. Shehadeh ... [et al.]. -- pt. G. Density functional theory and MD simulations. Dynamics of metal clusters in rare gas clusters / M. Baer ... [et al.]. Reinhard and E. Suraud. Kohn-Sham calculations combined with an average pair-density functional theory / P. Gori-Giorgi and A. Savin. Correlations, collision frequency and optical properties in laser excited clusters / H. Reinholz, T. Raitza and G. R

  8. Simple simulations of DNA condensation.

    PubMed Central

    Stevens, M J

    2001-01-01

    Molecular dynamics simulations of a simple, bead-spring model of semiflexible polyelectrolytes such as DNA are performed. All charges are explicitly treated. Starting from extended, noncondensed conformations, condensed structures form in the simulations with tetravalent or trivalent counterions. No condensates form or are stable for divalent counterions. The mechanism by which condensates form is described. Briefly, condensation occurs because electrostatic interactions dominate entropy, and the favored coulombic structure is a charge-ordered state. Condensation is a generic phenomenon and occurs for a variety of polyelectrolyte parameters. Toroids and rods are the condensate structures. Toroids form preferentially when the molecular stiffness is sufficiently strong. PMID:11159388

  9. Simple Simulations of DNA Condensation

    SciTech Connect

    STEVENS,MARK J.

    2000-07-12

    Molecular dynamics simulations of a simple, bead-spring model of semiflexible polyelectrolytes such as DNA are performed. All charges are explicitly treated. Starting from extended, noncondensed conformations, condensed structures form in the simulations with tetravalent or trivalent counterions. No condensates form or are stable for divalent counterions. The mechanism by which condensates form is described. Briefly, condensation occurs because electrostatic interactions dominate entropy, and the favored Coulombic structure is a charge ordered state. Condensation is a generic phenomena and occurs for a variety of polyelectrolyte parameters. Toroids and rods are the condensate structures. Toroids form preferentially when the molecular stiffness is sufficiently strong.

  10. Mitotic chromosome condensation in vertebrates

    SciTech Connect

    Vagnarelli, Paola

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes of

  11. Tidal waves in 102Pd: a rotating condensate of multiple d bosons.

    PubMed

    Ayangeakaa, A D; Garg, U; Caprio, M A; Carpenter, M P; Ghugre, S S; Janssens, R V F; Kondev, F G; Matta, J T; Mukhopadhyay, S; Patel, D; Seweryniak, D; Sun, J; Zhu, S; Frauendorf, S

    2013-03-08

    Low-lying collective excitations in even-even vibrational and transitional nuclei may be described semiclassically as quadrupole running waves on the surface of the nucleus ("tidal waves"), and the observed vibrational-rotational behavior can be thought of as resulting from a rotating condensate of interacting d bosons. These concepts have been investigated by measuring lifetimes of the levels in the yrast band of the (102)Pd nucleus with the Doppler shift attenuation method. The extracted B(E2) reduced transition probabilities for the yrast band display a monotonic increase with spin, in agreement with the interpretation based on rotation-induced condensation of aligned d bosons.

  12. Detail of Bright Angel stone vault, containing condenser, Hoffman condensation ...

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

    Detail of Bright Angel stone vault, containing condenser, Hoffman condensation pump, Jennings vacuum heating pump, and misc. pipes and valves. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  13. Condensate removal device

    DOEpatents

    Maddox, James W.; Berger, David D.

    1984-01-01

    A condensate removal device is disclosed which incorporates a strainer in unit with an orifice. The strainer is cylindrical with its longitudinal axis transverse to that of the vapor conduit in which it is mounted. The orifice is positioned inside the strainer proximate the end which is remoter from the vapor conduit.

  14. Boron-10 Lined Proportional Counter Wall Effects

    SciTech Connect

    Siciliano, Edward R.; Kouzes, Richard T.

    2012-05-01

    The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube based system in the configuration of a coincidence counter. This report provides information about how variations in proportional counter radius and gas pressure in a typical coincident counter design might affect the observed signal from boron-lined tubes. A discussion comparing tubes to parallel plate counters is also included.

  15. Meson multiplicity versus energy in relativistic nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Atwater, T. W.; Freier, P. S.

    1986-01-01

    A systematic study of meson multiplicity as a function of energy at energies up to 100 GeV/u in nucleus-nucleus collisions has been made, using cosmic-ray data in nuclear emulsion. The data are consistent with simple nucleon-nucleon superposition models. Multiplicity per interacting nucleon in AA collisions does not appear to differ significantly from pp collisions.

  16. Momentum loss in proton-nucleus and nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Khan, Ferdous; Townsend, Lawrence W.

    1993-01-01

    An optical model description, based on multiple scattering theory, of longitudinal momentum loss in proton-nucleus and nucleus-nucleus collisions is presented. The crucial role of the imaginary component of the nucleon-nucleon transition matrix in accounting for longitudinal momentum transfer is demonstrated. Results obtained with this model are compared with Intranuclear Cascade (INC) calculations, as well as with predictions from Vlasov-Uehling-Uhlenbeck (VUU) and quantum molecular dynamics (QMD) simulations. Comparisons are also made with experimental data where available. These indicate that the present model is adequate to account for longitudinal momentum transfer in both proton-nucleus and nucleus-nucleus collisions over a wide range of energies.

  17. SIMULATING THE IN SITU CONDENSATION PROCESS OF SOLAR PROMINENCES

    SciTech Connect

    Xia, C.; Keppens, R.; Antolin, P.; Porth, O.

    2014-09-10

    Prominences in the solar corona are a hundredfold cooler and denser than their surroundings, with a total mass of 10{sup 13} up to 10{sup 15} g. Here, we report on the first comprehensive simulations of three-dimensional, thermally and gravitationally stratified magnetic flux ropes where in situ condensation to a prominence occurs due to radiative losses. After a gradual thermodynamic adjustment, we witness a phase where runaway cooling occurs while counter-streaming shearing flows drain off mass along helical field lines. After this drainage, a prominence-like condensation resides in concave upward field regions, and this prominence retains its overall characteristics for more than two hours. While condensing, the prominence establishes a prominence-corona transition region where magnetic field-aligned thermal conduction is operative during the runaway cooling. The prominence structure represents a force-balanced state in a helical flux rope. The simulated condensation demonstrates a right-bearing barb, as a remnant of the drainage. Synthetic images at extreme ultraviolet wavelengths follow the onset of the condensation, and confirm the appearance of horns and a three-part structure for the stable prominence state, as often seen in erupting prominences. This naturally explains recent Solar Dynamics Observatory views with the Atmospheric Imaging Assembly on prominences in coronal cavities demonstrating horns.

  18. Nanostructure-induced DNA condensation

    NASA Astrophysics Data System (ADS)

    Zhou, Ting; Llizo, Axel; Wang, Chen; Xu, Guiying; Yang, Yanlian

    2013-08-01

    The control of the DNA condensation process is essential for compaction of DNA in chromatin, as well as for biological applications such as nonviral gene therapy. This review endeavours to reflect the progress of investigations on DNA condensation effects of nanostructure-based condensing agents (such as nanoparticles, nanotubes, cationic polymer and peptide agents) observed by using atomic force microscopy (AFM) and other techniques. The environmental effects on structural characteristics of nanostructure-induced DNA condensates are also discussed.

  19. Recovery of condensate water quality in power generator's surface condenser

    NASA Astrophysics Data System (ADS)

    Kurniawan, Lilik Adib

    2017-03-01

    In PT Badak NGL Plant, steam turbines are used to drive major power generators, compressors, and pumps. Steam exiting the turbines is condensed in surface condensers to be returned to boilers. Therefore, surface condenser performance and quality of condensate water are very important. One of the recent problem was caused by the leak of a surface condenser of Steam Turbine Power Generator. Thesteam turbine was overhauled, leaving the surface condenser idle and exposed to air for more than 1.5 years. Sea water ingress due to tube leaks worsens the corrosionof the condenser shell. The combination of mineral scale and corrosion product resulting high conductivity condensate at outlet condenser when we restarted up, beyond the acceptable limit. After assessing several options, chemical cleaning was the best way to overcome the problem according to condenser configuration. An 8 hour circulation of 5%wt citric acid had succeed reducing water conductivity from 50 μmhos/cm to below 5 μmhos/cm. The condensate water, then meets the required quality, i.e. pH 8.3 - 9.0; conductivity ≤ 5 μmhos/cm, therefore the power generator can be operated normally without any concern until now.

  20. Feshbach-Einstein Condensates

    SciTech Connect

    Rousseau, V. G.; Denteneer, P. J. H.

    2009-01-09

    We investigate the phase diagram of a two-species Bose-Hubbard model describing atoms and molecules on a lattice, interacting via a Feshbach resonance. We identify a region where the system exhibits an exotic super-Mott phase and regions with phases characterized by atomic and/or molecular condensates. Our approach is based on a recently developed exact quantum Monte Carlo algorithm: the stochastic Green function algorithm with tunable directionality. We confirm some of the results predicted by mean-field studies, but we also find disagreement with these studies. In particular, we find a phase with an atomic but no molecular condensate, which is missing in all mean-field phase diagrams.

  1. Gravity triggered neutrino condensates

    SciTech Connect

    Barenboim, Gabriela

    2010-11-01

    In this work we use the Schwinger-Dyson equations to study the possibility that an enhanced gravitational attraction triggers the formation of a right-handed neutrino condensate, inducing dynamical symmetry breaking and generating a Majorana mass for the right-handed neutrino at a scale appropriate for the seesaw mechanism. The composite field formed by the condensate phase could drive an early epoch of inflation. We find that to the lowest order, the theory does not allow dynamical symmetry breaking. Nevertheless, thanks to the large number of matter fields in the model, the suppression by additional powers in G of higher order terms can be compensated, boosting them up to their lowest order counterparts. This way chiral symmetry can be broken dynamically and the infrared mass generated turns out to be in the expected range for a successful seesaw scenario.

  2. Gravitational vacuum condensate stars

    PubMed Central

    Mazur, Pawel O.; Mottola, Emil

    2004-01-01

    A new final state of gravitational collapse is proposed. By extending the concept of Bose–Einstein condensation to gravitational systems, a cold, dark, compact object with an interior de Sitter condensate pv = -ρv and an exterior Schwarzschild geometry of arbitrary total mass M is constructed. These regions are separated by a shell with a small but finite proper thickness ℓ of fluid with equation of state p = +ρ, replacing both the Schwarzschild and de Sitter classical horizons. The new solution has no singularities, no event horizons, and a global time. Its entropy is maximized under small fluctuations and is given by the standard hydrodynamic entropy of the thin shell, which is of the order kBℓMc/, instead of the Bekenstein–Hawking entropy formula, SBH = 4πkBGM2/c. Hence, unlike black holes, the new solution is thermodynamically stable and has no information paradox. PMID:15210982

  3. The intercalatus nucleus of Staderini.

    PubMed

    Cascella, Marco

    2016-01-01

    Rutilio Staderini was one of the leading Italian anatomists of the twentieth century, together with some scientists, such as Giulio Chiarugi, Giovanni Vitali, and others. He was also a member of a new generation of anatomists. They had continued the tradition of the most famous Italian scientists, which started from the Renaissance up until the nineteenth century. Although he carried out important studies of neuroanatomy and comparative anatomy, as well as embryology, his name is rarely remembered by most medical historians. His name is linked to the nucleus he discovered: the Staderini nucleus or intercalated nucleus, a collection of nerve cells in the medulla oblongata located lateral to the hypoglossal nucleus. This article focuses on the biography of the neuroanatomist as well as the nucleus that carries his name and his other research, especially on comparative anatomy and embryology.

  4. Sidestream condensate polishing for PWRs

    SciTech Connect

    Shor, S.W.W.; Yim, S.L.; Rios, J.; Liu, J.

    1986-06-01

    Condensate polishers are used in power plant condensate system to remove both particulate matter and ionized corrodents. Their conventional location is just downstream of the hotwell pumps (condensate pumps). Most polisher installations have enough flow capacity to polish 100% of the condensate. This inline configuration has some disadvantage, including a flow that varies with unit load and tends to disturb the polisher beds and reduce their effectiveness, and a potential for interrupting flow to the feedwater pumps. An alternate arrangement where water is extracted from either the condenser or the condensate system, polished and returned to the system, has been used in a few plants. Three different ways of doing this have been used: divide the condenser hotwell into two parts, one of which receives condensate from the tube bundles and the other of which is sheltered. Take unpolished condensate from the first part, purify it and return it to the other part from which the condensate pumps take suction; take unpolished condensate from one end of a divided header on the suction side of the hotwell pumps and after polishing it return it to the other end; and take unpolished condensate from a header on the discharge side of the condensate pumps, purify it and return it to the condensate system a short distance downstream. The three variants are analyzed in this report. It is concluded that the variant where the connections are on the discharge side of the condensate pumps is the most desirable for retrofitting, in all cases being far easier to retrofit than an inline polisher. In many cases it will be most desirable for new construction.

  5. Bose-Einstein Condensation

    SciTech Connect

    El-Sherbini, Th.M.

    2005-03-17

    This article gives a brief review of Bose-Einstein condensation. It is an exotic quantum phenomenon that was observed in dilute atomic gases for the first time in 1995. It exhibits a new state of matter in which a group of atoms behaves as a single particle. Experiments on this form of matter are relevant to many different areas of physics- from atomic clocks and quantum computing to super fluidity, superconductivity and quantum phase transition.

  6. Asymmetric condensed dark matter

    SciTech Connect

    Aguirre, Anthony; Diez-Tejedor, Alberto E-mail: alberto.diez@fisica.ugto.mx

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  7. Counter tube window and X-ray fluorescence analyzer study

    NASA Technical Reports Server (NTRS)

    Hertel, R.; Holm, M.

    1973-01-01

    A study was performed to determine the best design tube window and X-ray fluorescence analyzer for quantitative analysis of Venusian dust and condensates. The principal objective of the project was to develop the best counter tube window geometry for the sensing element of the instrument. This included formulation of a mathematical model of the window and optimization of its parameters. The proposed detector and instrument has several important features. The instrument will perform a near real-time analysis of dust in the Venusian atmosphere, and is capable of measuring dust layers less than 1 micron thick. In addition, wide dynamic measurement range will be provided to compensate for extreme variations in count rates. An integral pulse-height analyzer and memory accumulate data and read out spectra for detail computer analysis on the ground.

  8. A Compact Water-Based Particle Condensation Monitor

    NASA Astrophysics Data System (ADS)

    Hering, S. V.

    2006-12-01

    A water-based, condensation particle counter (ME-WCPC, TSI-3781) has been developed to provide monitoring of particle number concentrations in ambient air and in occupied spaces. This instrument weighs 2.3 kg and has a lower size detection limit near 7 nm. Its internal data logging can date-stamp and store up to two weeks of one-minute data. Reported here is the evaluation of this instrument under field conditions. Comparison is made to three types of butanol-based counters (TSI Models 3010, 3022, 3025) and to bench- scale water based counters (TSI Models 3785 and 3786). Ambient sampling was done in the summer and winter in Riverside, California, and in the winter in Berkeley, California. Residential measurements were made at two homes, including one kitchen. Direct assessment of automotive emissions was made through measurements from the air duct of the Caldecott Freeway Tunnel. At all locations the collocated ME-WCPCs agreed with each other, with the square of the correlation coefficient above 0.97 and slopes near 1. For particle number concentrations below 200,000 cm-3, measurements from the ME-WCPC are within a 10 percent, on average, of those from the butaonol-based TSI-3022, and higher than those from the dilution- corrected TSI-3010, consistent with the differences in the lower particle size limits cutpoints of the instruments (7 nm for the TSI-3022, 10 nm for the TSI-3010). The two ultrafine condensation particle counters, the water- based TSI-3786, and the butanol based TSI-3025, both have lower detection limits of 2.5 nm. These instruments were tightly correlated, with R2 greater than 0.99 with 2% to 9% higher concentrations reported on average from the water-based ultrafine instrument. The one-minute data show consistent diurnal variations, with maxima occurring during the morning, evening hours, and often again near midnight.

  9. Counter machines and crystallographic structures

    PubMed Central

    Krajcevski, M.; McColm, G.

    2016-01-01

    One way to depict a crystallographic structure is by a periodic (di)graph, i.e., a graph whose group of automorphisms has a translational subgroup of finite index acting freely on the structure. We establish a relationship between periodic graphs representing crystallographic structures and an infinite hierarchy of intersection languages 𝒟𝒞ℒd, d = 0, 1, 2, …, within the intersection classes of deterministic context-free languages. We introduce a class of counter machines that accept these languages, where the machines with d counters recognize the class 𝒟𝒞ℒd An intersection of d languages in 𝒟𝒞ℒ1 defines 𝒟𝒞ℒd. We prove that there is a one-to-one correspondence between sets of walks starting and ending in the same unit of a d-dimensional periodic (di)graph and the class of languages in 𝒟𝒞ℒd. The proof uses the following result: given a digraph Δ and a group G, there is a unique digraph Γ such that G ≤ Aut Γ, G acts freely on the structure, and Γ/G ≅ Δ. PMID:27616944

  10. Osmotic stress alters chromatin condensation and nucleocytoplasmic transport

    SciTech Connect

    Finan, John D.; Leddy, Holly A.; Guilak, Farshid

    2011-05-06

    Highlights: {yields} The rate of nucleocytoplasmic transport increases under hyper-osmotic stress. {yields} The mechanism is a change in nuclear geometry, not a change in permeability of the nuclear envelope. {yields} Intracytoplasmic but not intranuclear diffusion is sensitive to osmotic stress. {yields} Pores in the chromatin of the nucleus enlarge under hyper-osmotic stress. -- Abstract: Osmotic stress is a potent regulator of biological function in many cell types, but its mechanism of action is only partially understood. In this study, we examined whether changes in extracellular osmolality can alter chromatin condensation and the rate of nucleocytoplasmic transport, as potential mechanisms by which osmotic stress can act. Transport of 10 kDa dextran was measured both within and between the nucleus and the cytoplasm using two different photobleaching methods. A mathematical model was developed to describe fluorescence recovery via nucleocytoplasmic transport. As osmolality increased, the diffusion coefficient of dextran decreased in the cytoplasm, but not the nucleus. Hyper-osmotic stress decreased nuclear size and increased nuclear lacunarity, indicating that while the nucleus was getting smaller, the pores and channels interdigitating the chromatin had expanded. The rate of nucleocytoplasmic transport was increased under hyper-osmotic stress but was insensitive to hypo-osmotic stress, consistent with the nonlinear osmotic properties of the nucleus. The mechanism of this osmotic sensitivity appears to be a change in the size and geometry of the nucleus, resulting in a shorter effective diffusion distance for the nucleus. These results may explain physical mechanisms by which osmotic stress can influence intracellular signaling pathways that rely on nucleocytoplasmic transport.

  11. Effect of spontaneous condensation on condensation heat transfer in the presence of non-condensable gases

    SciTech Connect

    Karl, J.; Hein, D.

    1999-07-01

    The presence of non condensable gases like nitrogen or air reduces the condensation heat transfer during condensation of binary steam mixtures. The non condensable gas accumulates in the vapor phase boundary layer and causes a high heat transfer resistance. Especially with high pressures and low water temperatures spontaneous condensation reduces heat transfer additionally. Fog forms within the steam-nitrogen boundary layer and the steam condenses on the water droplets of the fog layer. The convective mass transfer to the cooling water interface diminishes. Raman spectroscopy and film theory are used to quantify this effect locally. The calculation of overall condensation rates in large steam nitrogen systems requires to use three dimensional CFD codes. The paper presents equations to predict fog formation in the boundary layer which can be implemented in CFD codes.

  12. Vertical Profiles of Cloud Condensation Nuclei, Condensation Nuclei, Optical Aerosol, Aerosol Optical Properties, and Aerosol Volatility Measured from Balloons

    NASA Technical Reports Server (NTRS)

    Deshler, T.; Snider, J. R.; Vali, G.

    1998-01-01

    Under the support of this grant a balloon-borne gondola containing a variety of aerosol instruments was developed and flown from Laramie, Wyoming, (41 deg N, 105 deg W) and from Lauder, New Zealand (45 deg S, 170 deg E). The gondola includes instruments to measure the concentrations of condensation nuclei (CN), cloud condensation nuclei (CCN), optically detectable aerosol (OA.) (r greater than or equal to 0.15 - 2.0 microns), and optical scattering properties using a nephelometer (lambda = 530 microns). All instruments sampled from a common inlet which was heated to 40 C on ascent and to 160 C on descent. Flights with the CN counter, OA counter, and nephelometer began in July 1994. The CCN counter was added in November 1994, and the engineering problems were solved by June 1995. Since then the flights have included all four instruments, and were completed in January 1998. Altogether there were 20 flights from Laramie, approximately 5 per year, and 2 from Lauder. Of these there were one or more engineering problems on 6 of the flights from Laramie, hence the data are somewhat limited on those 6 flights, while a complete data set was obtained from the other 14 flights. Good CCN data are available from 12 of the Laramie flights. The two flights from Lauder in January 1998 were successful for all measurements. The results from these flights, and the development of the balloon-bome CCN counter have formed the basis for five conference presentations. The heated and unheated CN and OA measurements have been used to estimate the mass fraction of the aerosol volatile, while comparisons of the nephelometer measurements were used to estimate the light scattering, associated with the volatile aerosol. These estimates were calculated for 0.5 km averages of the ascent and descent data between 2.5 km and the tropopause, near 11.5 km.

  13. Condensed Matter Nuclear Science

    NASA Astrophysics Data System (ADS)

    Biberian, Jean-Paul

    2006-02-01

    1. General. A tribute to gene Mallove - the "Genie" reactor / K. Wallace and R. Stringham. An update of LENR for ICCF-11 (short course, 10/31/04) / E. Storms. New physical effects in metal deuterides / P. L. Hagelstein ... [et al.]. Reproducibility, controllability, and optimization of LENR experiments / D. J. Nagel -- 2. Experiments. Electrochemistry. Evidence of electromagnetic radiation from Ni-H systems / S. Focardi ... [et al.]. Superwave reality / I. Dardik. Excess heat in electrolysis experiments at energetics technologies / I. Dardik ... [et al.]. "Excess heat" during electrolysis in platinum/K[symbol]CO[symbol]/nickel light water system / J. Tian ... [et al.]. Innovative procedure for the, in situ, measurement of the resistive thermal coefficient of H(D)/Pd during electrolysis; cross-comparison of new elements detected in the Th-Hg-Pd-D(H) electrolytic cells / F. Celani ... [et al.]. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for superstoihiometric H/D sites / A. Lipson ... [et al.]. Plasma electrolysis. Calorimetry of energy-efficient glow discharge - apparatus design and calibration / T. B. Benson and T. O. Passell. Generation of heat and products during plasma electrolysis / T. Mizuno ... [et al.]. Glow discharge. Excess heat production in Pd/D during periodic pulse discharge current in various conditions / A. B. Karabut. Beam experiments. Accelerator experiments and theoretical models for the electron screening effect in metallic environments / A. Huke, K. Czerski, and P. Heide. Evidence for a target-material dependence of the neutron-proton branching ratio in d+d reactions for deuteron energies below 20keV / A. Huke ... [et al.]. Experiments on condensed matter nuclear events in Kobe University / T. Minari ... [et al.]. Electron screening constraints for the cold fusion / K. Czerski, P. Heide, and A. Huke. Cavitation. Low mass 1.6 MHz sonofusion reactor / R. Stringham. Particle detection. Research

  14. Structures and functions in the crowded nucleus: new biophysical insights

    NASA Astrophysics Data System (ADS)

    Hancock, Ronald

    2014-09-01

    Concepts and methods from the physical sciences have catalysed remarkable progress in understanding the cell nucleus in recent years. To share this excitement with physicists and encourage their interest in this field, this review offers an overview of how the physics which underlies structures and functions in the nucleus is becoming more clear thanks to methods which have been developed to simulate and study macromolecules, polymers, and colloids. The environment in the nucleus is very crowded with macromolecules, making entropic (depletion) forces major determinants of interactions. Simulation and experiments are consistent with their key role in forming membraneless compartments such as nucleoli, PML and Cajal bodies, and discrete "territories" for chromosomes. The chromosomes, giant linear polyelectrolyte polymers, exist in vivo in a state like a polymer melt. Looped conformations are predicted in crowded conditions, and have been confirmed experimentally and are central to the regulation of gene expression. Polymer theory has revealed how the chromosomes are so highly compacted in the nucleus, forming a "crumpled globule" with fractal properties which avoids knots and entanglements in DNA while allowing facile accessibility for its replication and transcription. Entropic repulsion between looped polymers can explain the confinement of each chromosome to a discrete region of the nucleus. Crowding and looping are predicted to facilitate finding the specific targets of factors which modulate activities of DNA. Simulation shows that entropic effects contribute to finding and repairing potentially lethal double-strand breaks in DNA by increasing the mobility of the broken ends, favouring their juxtaposition for repair. Signaling pathways are strongly influenced by crowding, which favours a processive mode of response (consecutive reactions without releasing substrates). This new information contributes to understanding the sometimes counter-intuitive consequences.

  15. Nanocarbon condensation in detonation

    NASA Astrophysics Data System (ADS)

    Bastea, Sorin

    2017-02-01

    We analyze the definition of the Gibbs free energy of a nanoparticle in a reactive fluid environment, and propose an approach for predicting the size of carbon nanoparticles produced by the detonation of carbon-rich explosives that regards their condensation as a nucleation process and takes into account absolute entropy effects of the cluster population. The results are consistent with experimental observations and indicate that such entropy considerations are important for determining chemical equilibrium states in energetic materials that contain an excess of carbon. The analysis may be useful for other applications that deal with the nucleation of nanoparticles under reactive conditions.

  16. Condensed Plasmas under Microgravity

    NASA Technical Reports Server (NTRS)

    Morfill, G. E.; Thomas, H. M.; Konopka, U.; Rothermel, H.; Zuzic, M.; Ivlev, A.; Goree, J.; Rogers, Rick (Technical Monitor)

    1999-01-01

    Experiments under microgravity conditions were carried out to study 'condensed' (liquid and crystalline) states of a colloidal plasma (ions, electrons, and charged microspheres). Systems with approximately 10(exp 6) microspheres were produced. The observed systems represent new forms of matter--quasineutral, self-organized plasmas--the properties of which are largely unexplored. In contrast to laboratory measurements, the systems under microgravity are clearly three dimensional (as expected); they exhibit stable vortex flows, sometimes adjacent to crystalline regions, and a central 'void,' free of microspheres.

  17. Nanocarbon condensation in detonation

    PubMed Central

    Bastea, Sorin

    2017-01-01

    We analyze the definition of the Gibbs free energy of a nanoparticle in a reactive fluid environment, and propose an approach for predicting the size of carbon nanoparticles produced by the detonation of carbon-rich explosives that regards their condensation as a nucleation process and takes into account absolute entropy effects of the cluster population. The results are consistent with experimental observations and indicate that such entropy considerations are important for determining chemical equilibrium states in energetic materials that contain an excess of carbon. The analysis may be useful for other applications that deal with the nucleation of nanoparticles under reactive conditions. PMID:28176827

  18. Confinement Contains Condensates

    SciTech Connect

    Brodsky, Stanley J.; Roberts, Craig D.; Shrock, Robert; Tandy, Peter C.

    2012-03-12

    Dynamical chiral symmetry breaking and its connection to the generation of hadron masses has historically been viewed as a vacuum phenomenon. We argue that confinement makes such a position untenable. If quark-hadron duality is a reality in QCD, then condensates, those quantities that have commonly been viewed as constant empirical mass-scales that fill all spacetime, are instead wholly contained within hadrons; i.e., they are a property of hadrons themselves and expressed, e.g., in their Bethe-Salpeter or light-front wave functions. We explain that this paradigm is consistent with empirical evidence, and incidentally expose misconceptions in a recent Comment.

  19. Compact fission counter for DANCE

    SciTech Connect

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J

    2010-11-06

    The Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 BF{sub 2} crystals with equal solid-angle coverage. DANCE is a 4{pi} {gamma}-ray calorimeter and designed to study the neutron-capture reactions on small quantities of radioactive and rare stable nuclei. These reactions are important for the radiochemistry applications and modeling the element production in stars. The recognition of capture event is made by the summed {gamma}-ray energy which is equivalent of the reaction Q-value and unique for a given capture reaction. For a selective group of actinides, where the neutron-induced fission reaction competes favorably with the neutron capture reaction, additional signature is needed to distinguish between fission and capture {gamma} rays for the DANCE measurement. This can be accomplished by introducing a detector system to tag fission fragments and thus establish a unique signature for the fission event. Once this system is implemented, one has the opportunity to study not only the capture but also fission reactions. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to {alpha} particles, which is important for experiments with {alpha}-emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. A PPAC with an ingenious design was fabricated in 2006 by integrating amplifiers into the target assembly. However, this counter was proved to be unsuitable for this application because of issues related to the stability of amplifiers and the ability to separate fission fragments from {alpha}'s. Therefore, a new design is needed. A LLNL proposal to develop a new PPAC for DANCE was funded by NA22 in FY09. The design goal is to minimize the mass for the proposed counter

  20. Surface albedo of cometary nucleus

    NASA Astrophysics Data System (ADS)

    Mukai, T.; Mukai, S.

    A variation of the albedo on the illuminated disk of a comet nucleus is estimated, taking into account the multiple reflection of incident light due to small scale roughness. The dependences of the average albedo over the illuminated disk on the degree of roughness and on the complex refractive index of the surface materials are examined. The variation estimates are compared with measurements of the nucleus albedo of Comet Halley (Reitsema et al., 1987).

  1. Cosmic curvature and condensation

    NASA Technical Reports Server (NTRS)

    Harwit, Martin

    1992-01-01

    It is shown that the universe may consist of a patchwork of domains with different Riemann curvature constants k = 0, +/-1. Features of a phase transition in which flat space breaks up in a transition 2k0 - k(-) + k(+) with initial scale factors R(-) = R(+) are postulated and explored. It is shown that such a transition is energetically permitted, has the equivalent of a Curie temperature, and can lead in a natural way to the formation of voids and galaxies. It is predicted that, if the ambient universe on average is well fitted by a purely k(-) space, with only occasional domains of k(+) containing galaxies, a density parameter of (A(z sub c + 1)) super -1 should be expected, where z sub c represents the redshift of the earliest objects to have condensed, and A takes on values ranging from about 5 to 3. Present observations of quasars would suggest a density of about 0.03 or 0.05, respectively, but it could be lower if earlier condensation took place.

  2. Drying of pulverized material with heated condensible vapor

    DOEpatents

    Carlson, Larry W.

    1986-01-01

    Apparatus for drying pulverized material utilizes a high enthalpy condensable vapor such as steam for removing moisture from the individual particles of the pulverized material. The initially wet particulate material is tangentially delivered by a carrier vapor flow to an upper portion of a generally vertical cylindrical separation drum. The lateral wall of the separation drum is provided with a plurality of flow guides for directing the vapor tangentially therein in the direction of particulate material flow. Positioned concentrically within the separation drum and along the longitudinal axis thereof is a water-cooled condensation cylinder which is provided with a plurality of collection plates, or fins, on the outer lateral surface thereof. The cooled collection fins are aligned counter to the flow of the pulverized material and high enthalpy vapor mixture to maximize water vapor condensation thereon. The condensed liquid which includes moisture removed from the pulverized material then flows downward along the outer surface of the coolant cylinder and is collected and removed. The particles travel in a shallow helix due to respective centrifugal and vertical acceleration forces applied thereto. The individual particles of the pulverized material are directed outwardly by the vortex flow where they contact the inner cylindrical surface of the separation drum and are then deposited at the bottom thereof for easy collection and removal. The pulverized material drying apparatus is particularly adapted for drying coal fines and facilitates the recovery of the pulverized coal.

  3. Drying of pulverized material with heated condensible vapor

    DOEpatents

    Carlson, L.W.

    1984-08-16

    Apparatus for drying pulverized material utilizes a high enthalpy condensable vapor such as steam for removing moisture from the individual particles of the pulverized material. The initially wet particulate material is tangentially delivered by a carrier vapor flow to an upper portion of a generally vertical cylindrical separation drum. The lateral wall of the separation drum is provided with a plurality of flow guides for directing the vapor tangentially therein in the direction of particulate material flow. Positioned concentrically within the separation drum and along the longitudinal axis thereof is a water-cooled condensation cylinder which is provided with a plurality of collection plates, or fines, on the outer lateral surface thereof. The cooled collection fines are aligned counter to the flow of the pulverized material and high enthalpy vapor mixture to maximize water vapor condensation thereon. The condensed liquid which includes moisture removed from the pulverized materials then flows downward along the outer surface of the coolant cylinder and is collected and removed. The particles travel in a shallow helix due to respective centrifugal and vertical acceleration forces applied thereto. The individual particles of the pulverized material are directed outwardly by the vortex flow where they contact the inner cylindrical surface of the separation drum and are then deposited at the bottom thereof for easy collection and removal. The pulverized material drying apparatus is particularly adapted for drying coal fines and facilitates the recovery of the pulverized coal. 2 figs.

  4. Pion condensation in holographic QCD

    SciTech Connect

    Albrecht, Dylan; Erlich, Joshua

    2010-11-01

    We study pion condensation at zero temperature in a hard-wall holographic model of hadrons with isospin chemical potential. We find that the transition from the hadronic phase to the pion condensate phase is first order except in a certain limit of model parameters. Our analysis suggests that immediately across the phase boundary the condensate acts as a stiff medium approaching the Zel'dovich limit of equal energy density and pressure.

  5. Light Obscuration Particle Counter Fuel Contamination Limits

    DTIC Science & Technology

    2015-10-08

    The 3 UNCLASSIFIED Energy Institute (EI) has published guidance documents and test methods relating to fuel quality measurement using... Energy (11) have conducted laboratory and field evaluations of particle counter technologies for fuel contamination monitoring. Testing has concluded...AND USE OF LIQUID FUELS Charleston, South Carolina USA 4-8 October 2015 LIGHT OBSCURATION PARTICLE COUNTER FUEL CONTAMINATION LIMITS Joel

  6. Pressure losses during steam flow and condensation in tubes and channels

    NASA Astrophysics Data System (ADS)

    Leontiev, A. I.; Milman, O. O.

    2014-12-01

    Theoretical and experimental investigations have revealed the dependence of parameters of the process of steam condensation in tubes and channels on the scheme of heat-exchange fluid flow, including counter, forward, and cross flow systems. The total pressure losses in the case of counter flow are greater than those in the case of forward and cross flow. This dependence is valid for the flow of gases and plasma in channels with significant density variation (e.g., due to heating and cooling). Pressure losses have been evaluated using various computational models, and the results are compared to experimental data.

  7. Condensation heat transfer in a microgravity environment

    NASA Technical Reports Server (NTRS)

    Chow, L. C.; Parish, R. C.

    1986-01-01

    In the present treatment of the condensation heat transfer process in a microgravity environment, two mechanisms for condensate removal are analyzed in light of two problems: (1) film condensation on a flat, porous plate, with condensate being removed by wall suction; and (2) the analytical prediction of the heat transfer coefficient of condensing annular flows, where the condensate film is driven by vapor shear. Both suction and vapor shear can effectively drain the condensate, ensuring continuous operation in microgravity.

  8. Counter traction makes endoscopic submucosal dissection easier.

    PubMed

    Oyama, Tsuneo

    2012-11-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

  9. Over-the-counter Acne Treatments

    PubMed Central

    Graber, Emmy M.

    2012-01-01

    Acne is a common dermatological disorder that most frequently affects adolescents; however, individuals may be affected at all ages. Many people who suffer from acne seek treatment from both prescription and over-the-counter acne medications. Due to convenience, lower cost, and difficulty getting an appointment with a dermatologist, the use of over-the-counter acne treatments is on the rise. As the plethora of over-the-counter acne treatment options can be overwhelming, it is important that dermatologists are well-versed on this subject to provide appropriate information about treatment regimens and potential drug interactions and that their patients see them as well-informed. This article reviews the efficacy of various over-the-counter acne treatments based on the current literature. A thorough literature review revealed there are many types of over-the-counter acne treatments and each are designed to target at least one of the pathogenic pathways that are reported to be involved in the development of acne lesions. Many of the key over-the-counter ingredients are incorporated in different formulations to broaden the spectrum and consumer appeal of available products. Unfortunately, many over-the-counter products are not well-supported by clinical studies, with a conspicuous absence of double-blind or investigator-blind, randomized, vehicle-controlled studies. Most studies that do exist on over-the-counter acne products are often funded by the manufacturer. Use of over-the-counter acne treatments is a mainstay in our society and it is important that dermatologists are knowledgeable about the different options, including potential benefits and limitations. Overall, over-the-counter acne therapies can be classified into the following five major groups: cleansers, leave-on products, mechanical treatments, essential oils, and vitamins. PMID:22808307

  10. Sensitivity of cross sections for elastic nucleus-nucleus scattering to halo nucleus density distributions

    SciTech Connect

    Alkhazov, G. D.; Sarantsev, V. V.

    2012-12-15

    In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the {sup 6}He and {sup 11}Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in {sup 6}He and {sup 11}Li.

  11. Current Over-the-Counter Medicine Label: Take a Look

    MedlinePlus

    ... Over-the-Counter Medicines The Over-the-Counter Medicine Label: Take a Look Share Tweet Linkedin Pin ... your family when using over-the-counter (OTC) medicines (available without a prescription). This is especially true ...

  12. Condenser for photolithography system

    DOEpatents

    Sweatt, William C.

    2004-03-02

    A condenser for a photolithography system, in which a mask image from a mask is projected onto a wafer through a camera having an entrance pupil, includes a source of propagating radiation, a first mirror illuminated by the radiation, a mirror array illuminated by the radiation reflected from said first mirror, and a second mirror illuminated by the radiation reflected from the array. The mirror array includes a plurality of micromirrors. Each of the micromirrors is selectively actuatable independently of each other. The first mirror and the second mirror are disposed such that the source is imaged onto a plane of the mask and the mirror array is imaged into the entrance pupil of the camera.

  13. Microgravity condensing heat exchanger

    NASA Technical Reports Server (NTRS)

    Thomas, Christopher M. (Inventor); Ma, Yonghui (Inventor); North, Andrew (Inventor); Weislogel, Mark M. (Inventor)

    2011-01-01

    A heat exchanger having a plurality of heat exchanging aluminum fins with hydrophilic condensing surfaces which are stacked and clamped between two cold plates. The cold plates are aligned radially along a plane extending through the axis of a cylindrical duct and hold the stacked and clamped portions of the heat exchanging fins along the axis of the cylindrical duct. The fins extend outwardly from the clamped portions along approximately radial planes. The spacing between fins is symmetric about the cold plates, and are somewhat more closely spaced as the angle they make with the cold plates approaches 90.degree.. Passageways extend through the fins between vertex spaces which provide capillary storage and communicate with passageways formed in the stacked and clamped portions of the fins, which communicate with water drains connected to a pump externally to the duct. Water with no entrained air is drawn from the capillary spaces.

  14. Cytoskeletal tension induces the polarized architecture of the nucleus

    PubMed Central

    Kim, Dong-Hwee; Wirtz, Denis

    2016-01-01

    The nuclear lamina is a thin filamentous meshwork that provides mechanical support to the nucleus and regulates essential cellular processes such as DNA replication, chromatin organization, cell division, and differentiation. Isolated horizontal imaging using fluorescence and electron microscopy has long suggested that the nuclear lamina is composed of structurally different A-type and B-type lamin proteins and nuclear lamin-associated membrane proteins that together form a thin layer that is spatially isotropic with no apparent difference in molecular content or density between the top and bottom of the nucleus. Chromosomes are condensed differently along the radial direction from the periphery of the nucleus to the nuclear center; therefore, chromatin accessibility for gene expression is different along the nuclear radius. However, 3D confocal reconstruction reveals instead that major lamin protein lamin A/C forms an apically polarized Frisbee-like dome structure in the nucleus of adherent cells. Here we show that both A-type lamins and transcriptionally active chromatins are vertically polarized by the tension exercised by the perinuclear actin cap (or actin cap) that is composed of highly contractile actomyosin fibers organized at the apical surface of the nucleus. Mechanical coupling between actin cap and lamina through LINC (linkers of nucleoskeleton and cytoskeleton) protein complexes induces an apical distribution of transcription-active subnucleolar compartments and epigenetic markers of transcription-active genes. This study reveals that intranuclear structures, such as nuclear lamina and chromosomal architecture, are apically polarized through the extranuclear perinuclear actin cap in a wide range of somatic adherent cells. PMID:25701041

  15. Amine catalyzed condensation of tetraethylorthosilicate

    NASA Technical Reports Server (NTRS)

    Jones, S.

    2001-01-01

    The catalysis of the condensation of hydrolyzed metal alkoxides by amines has been mentioned in the literature, but there has been no systematic study of their influence on the rate of the condensation reaction of the alkoxide and the microstructure of the resultant gel.

  16. Instability of counter-rotating stellar disks

    NASA Astrophysics Data System (ADS)

    Hohlfeld, R. G.; Lovelace, R. V. E.

    2015-09-01

    We use an N-body simulation, constructed using GADGET-2, to investigate an accretion flow onto an astrophysical disk that is in the opposite sense to the disk's rotation. In order to separate dynamics intrinsic to the counter-rotating flow from the impact of the flow onto the disk, we consider an initial condition in which the counter-rotating flow is in an annular region immediately exterior the main portion of the astrophysical disk. Such counter-rotating flows are seen in systems such as NGC 4826 (known as the "Evil Eye Galaxy"). Interaction between the rotating and counter-rotating components is due to two-stream instability in the boundary region. A multi-armed spiral density wave is excited in the astrophysical disk and a density distribution with high azimuthal mode number is excited in the counter-rotating flow. Density fluctuations in the counter-rotating flow aggregate into larger clumps and some of the material in the counter-rotating flow is scattered to large radii. Accretion flow processes such as this are increasingly seen to be of importance in the evolution of multi-component galactic disks.

  17. Exact periodic and solitonic states of the spinor condensates in a uniform external potential

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Hai; Yang, Shi-Jie

    2016-08-01

    We propose a method to analytically solve the one-dimensional coupled nonlinear Gross-Pitaevskii equations which govern the motion of the spinor Bose-Einstein condensates. In a uniform external potential, several classes of exact periodic and solitonic solutions, either in real or in complex forms, are obtained for both the F=1 and F=2 condensates for the Hamiltonian comprising the kinetic energy, the linear and the quadratic Zeeman energies. Real solutions take the form of composite soliton trains. Complex solutions correspond to the mass counter-flows as well as spin currents. These solutions are general that contains neither approximations nor constraints on the system parameters.

  18. APPARATUS FOR CONDENSATION AND SUBLIMATION

    DOEpatents

    Schmidt, R.J.; Fuis, F. Jr.

    1958-10-01

    An apparatus is presented for the sublimation and condensation of uranium compounds in order to obtain an improved crystalline structure of this material. The apparatus comprises a vaporizing chamber and condensing structure connected thereto. There condenser is fitted with a removable liner having a demountable baffle attached to the liner by means of brackets and a removable pin. The baffle is of spiral cross-section and is provided with cooling coils disposed between the surfaces of the baffle for circulation of a temperature controlling liquid within the baffle. The cooling coll provides for controlllng the temperature of the baffle to insure formatlon of a satisfactory condensate, and the removable liner facilitates the removal of condensate formed during tbe sublimation process.

  19. Chromatin condensation during terminal erythropoiesis.

    PubMed

    Zhao, Baobing; Yang, Jing; Ji, Peng

    2016-09-02

    Mammalian terminal erythropoiesis involves gradual but dramatic chromatin condensation steps that are essential for cell differentiation. Chromatin and nuclear condensation is followed by a unique enucleation process, which is believed to liberate more spaces for hemoglobin enrichment and enable the generation of a physically flexible mature red blood cell. Although these processes have been known for decades, the mechanisms are still unclear. Our recent study reveals an unexpected nuclear opening formation during mouse terminal erythropoiesis that requires caspase-3 activity. Major histones, except H2AZ, are partially released from the opening, which is important for chromatin condensation. Block of the nuclear opening through caspase inhibitor or knockdown of caspase-3 inhibits chromatin condensation and enucleation. We also demonstrate that nuclear opening and histone release are cell cycle regulated. These studies reveal a novel mechanism for chromatin condensation in mammalia terminal erythropoiesis.

  20. Detecting the elusive blazar counter-jets

    NASA Astrophysics Data System (ADS)

    Liodakis, I.; Pavlidou, V.; Angelakis, E.

    2017-02-01

    Detection of blazar pc scale counter-jets is difficult, but it can provide invaluable insight into the relativistic effects, radiative processes and the complex mechanisms of jet production, collimation and accelation in blazars. We build on recent populations models (optimized using the MOJAVE apparent velocity and redshift distributions) in order to derive the distribution of jet-to-counter-jet ratios and the flux densities of the counter-jet at different frequencies, in an effort to set minimum sensitivity limits required for existing and future telescope arrays in order to detect these elusive counter-jets. We find that: for the BL Lacs, 5 per cent of their counter-jets have a flux density higher than 100 mJy, 15 per cent are higher than 10 mJy, and 32 per cent have higher flux density than 1 mJy, whereas for the FSRQs, 8 per cent have a flux density higher than 10 mJy, 17 per cent are higher than 1 mJy, and 32 per cent are higher than 0.1 mJy (at 15 GHz). Future telescopes like the SKA and newly operating like e-MERLIN and JVLA may detect up to 99 per cent of the BL Lac and 77 per cent of the FSRQ counter-jets. Sources with both low apparent velocity and a low Doppler factor make prime candidates for counter-jet detection. Combining our findings with the literature values, we have identified five such counter-jet detection candidates. Finally, we discuss possible effects beyond relativistic deboosting that may complicate the detection of counter-jets and that need to be accounted for in the interpretation of detections.

  1. Acoustic counter-sniper system

    NASA Astrophysics Data System (ADS)

    Duckworth, Gregory L.; Gilbert, Douglas C.; Barger, James E.

    1997-02-01

    BBN has developed, tested, and fielded pre-production versions of a versatile acoustics-based counter-sniper system. This system was developed by BBN for the DARPA Tactical Technology Office to provide a low cost and accurate sniper detection and localization system. The system uses observations of the shock wave from supersonic bullets to estimate the bullet trajectory, Mach number, and caliber. If muzzle blast observations are also available from unsilenced weapons, the exact sniper location along the trajectory is also estimated. A newly developed and very accurate model of the bullet ballistics and acoustic radiation is used which includes bullet deceleration. This allows the use of very flexible acoustic sensor types and placements, since the system can model the bullet's flight, and hence the acoustic observations, over a wide area very accurately. System sensor configurations can be as simple as two small four element tetrahedral microphone arrays on either side of the area to be protected, or six omnidirectional microphones spread over the area to be monitored. Increased performance can be obtained by expanding the sensor field in size or density, and the system software is easily reconfigured to accommodate this at deployment time. Sensor nodes can be added using wireless network telemetry or hardwired cables to the command node processing and display computer. The system has been field tested in three government sponsored tests in both rural and simulated urban environments at the Camp Pendleton MOUT facility. Performance was characterized during these tests for various shot geometries and bullet speeds and calibers.

  2. Monte Carlo Shower Counter Studies

    NASA Technical Reports Server (NTRS)

    Snyder, H. David

    1991-01-01

    Activities and accomplishments related to the Monte Carlo shower counter studies are summarized. A tape of the VMS version of the GEANT software was obtained and installed on the central computer at Gallaudet University. Due to difficulties encountered in updating this VMS version, a decision was made to switch to the UNIX version of the package. This version was installed and used to generate the set of data files currently accessed by various analysis programs. The GEANT software was used to write files of data for positron and proton showers. Showers were simulated for a detector consisting of 50 alternating layers of lead and scintillator. Each file consisted of 1000 events at each of the following energies: 0.1, 0.5, 2.0, 10, 44, and 200 GeV. Data analysis activities related to clustering, chi square, and likelihood analyses are summarized. Source code for the GEANT user subprograms and data analysis programs are provided along with example data plots.

  3. Disruption of human vigilin impairs chromosome condensation and segregation.

    PubMed

    Wei, Ling; Xie, Xiaoyan; Li, Junhong; Li, Ran; Shen, Wenyan; Duan, Shuwang; Zhao, Rongce; Yang, Wenli; Liu, Qiuying; Fu, Qiang; Qin, Yang

    2015-11-01

    Appropriate packaging and condensation are critical for eukaryotic chromatin's accommodation and separation during cell division. Human vigilin, a multi-KH-domain nucleic acid-binding protein, is associated with alpha satellites of centromeres. DDP1, a vigilin's homolog, is implicated with chromatin condensation and segregation. The expression of vigilin was previously reported to elevate in highly proliferating tissues and increased in a subset of hepatocellular carcinoma patients. Other studies showed that vigilin interacts with CTCF, contributes to regulation of imprinted genes Igf2/H19, and colocalizes with HP1α on heterochromatic satellite 2 and β-satellite repeats. These studies indicate that human vigilin might be involved in chromatin remodeling and regular cell growth. To investigate the potential role of human vigilin in cell cycle, the correlations between vigilin and chromosomal condensation and segregation were studied. Depletion of human vigilin by RNA interference in HepG2 cells resulted in chromosome undercondensation and various chromosomal defects during mitotic phase, including chromosome misalignments, lagging chromosomes, and chromosome bridges. Aberrant polyploid nucleus in telophase was also observed. Unlike the abnormal staining pattern of chromosomes, the shape of spindle was normal. Furthermore, the chromatin showed a greater sensitivity to MNase digestion. Collectively, our findings show that human vigilin apparently participates in chromatin condensation and segregation.

  4. Scintillation counter with WLS fiber readout

    NASA Astrophysics Data System (ADS)

    Bukin, D. A.; Druzhinin, V. P.; Golubev, V. B.; Serednyakov, S. I.

    1997-02-01

    The parameters of a cylindrical scintillation counter of 126 mm in diameter and 370 mm in length with wavelength shifter (WLS) fiber readout are presented. The fibers are glued into machined grooves along the scintillator. Light from both ends of the WLS fibers is transmitted to separate photomultipliers by 1 m long clear optical fibers. The average total signal, collected from both sides of the counter is equivalent to 8 photoelectrons per minimum ionizing particle. The described cylindrical scintillation counter is a part of inner system of collider detector SND.

  5. Asymmetric counter propagation of domain walls

    NASA Astrophysics Data System (ADS)

    Andrade-Silva, I.; Clerc, M. G.; Odent, V.

    2016-07-01

    Far from equilibrium systems show different states and domain walls between them. These walls, depending on the type of connected equilibria, exhibit a rich spatiotemporal dynamics. Here, we investigate the asymmetrical counter propagation of domain walls in an in-plane-switching cell filled with a nematic liquid crystal. Experimentally, we characterize the shape and speed of the domain walls. Based on the molecular orientation, we infer that the counter propagative walls have different elastic deformations. These deformations are responsible of the asymmetric counter propagating fronts. Theoretically, based on symmetry arguments, we propose a simple bistable model under the influence of a nonlinear gradient, which qualitatively describes the observed dynamics.

  6. GEIGER-MULLER TYPE COUNTER TUBE

    DOEpatents

    Fowler, I.L.; Watt, L.A.K.

    1959-12-15

    A single counter tube capable of responding to a wide range of intensities is described. The counter tube comprises a tubular cathode and an anode extending centrally of the cathode. The spacing between the outer surface of the anode and the inner surface of the cathode is varied along the length of the tube to provide different counting volumes in adjacent portions of the tube. A large counting volume in one portion adjacent to a low-energy absorption window gives adequate sensitivity for measuring lowintensity radiation, while a smaller volume with close electrode spacing is provided in the counter to make possible measurement of intense garnma radiation fields.

  7. Micronucleus formation during chromatin condensation and under apoptotic conditions.

    PubMed

    Kiraly, Gabor; Simonyi, Athene S; Turani, Melinda; Juhasz, Istvan; Nagy, Gabor; Banfalvi, Gaspar

    2017-02-01

    In early S phase the newly replicated DNA is folded back to increasingly compact structures. The process of chromatin condensation inside the nucleus starts with the formation of a micronucleus observed in five established cell lines (K562, CHO, Indian muntjac, murine preB and SCC). Supercoiling of chromatin generates a polarized end-plate region extruded from the nucleus. The extruded chromatin is turned around itself forming the head portion (micronucleus) visible by fluorescence microscopy until the middle of S phase when chromatin structures are succeeded by distinguishable early forms of chromosomes. The generation of micronuclei upon apoptotic treatment was achieved by the methotrexate (MTX) treatment of cells. A close correlation was found between the frequency of micronucleus and MTX concentration, with low frequency at low (0.1 µM) and increasingly higher frequency between 1 and 100 µM concentrations. Characteristic deformation and shrinkage of nuclei indicated apoptosis. High MTX concentration (100 µM) caused the enlargement and necrotic disruption of nuclei. Inhibition of DNA synthesis during replicative DNA synthesis by biotinylated nucleotide prevented the formation of metaphase chromosomes and elevated the frequency of early intermediates of chromosome condensation including micronucleus formation. Based on these observations the micronucleus is regarded as: (a) a regularly occuring element of early chromatin condensation and (b) a typical sign of nuclear membrane damage under toxic conditions. Explanation is given why the micronucleus is hidden in nuclei under normal chromatin condensation and why chromatin motifs including micronuclei become visible upon cellular damage.

  8. Formin' actin in the nucleus.

    PubMed

    Baarlink, Christian; Grosse, Robert

    2014-01-01

    Many if not most proteins can, under certain conditions, change cellular compartments, such as, for example, shuttling from the cytoplasm to the nucleus. Thus, many proteins may exert functions in various and very different subcellular locations, depending on the signaling context. A large amount of actin regulatory proteins has been detected in the mammalian cell nucleus, although their potential roles are much debated and are just beginning to emerge. Recently, members of the formin family of actin nucleators were also reported to dynamically localize to the nuclear environment. Here we discuss our findings that specific diaphanous-related formins can promote nuclear actin assembly in a signal-dependent manner.

  9. Functionalized active-nucleus complex sensor

    DOEpatents

    Pines, Alexander; Wemmer, David E.; Spence, Megan; Rubin, Seth

    2003-11-25

    A functionalized active-nucleus complex sensor that selectively associates with one or more target species, and a method for assaying and screening for one or a plurality of target species utilizing one or a plurality of functionalized active-nucleus complexes with at least two of the functionalized active-nucleus complexes having an attraction affinity to different corresponding target species. The functionalized active-nucleus complex has an active-nucleus and a targeting carrier. The method involves functionalizing an active-nucleus, for each functionalized active-nucleus complex, by incorporating the active-nucleus into a macromolucular or molecular complex that is capable of binding one of the target species and then bringing the macromolecular or molecular complexes into contact with the target species and detecting the occurrence of or change in a nuclear magnetic resonance signal from each of the active-nuclei in each of the functionalized active-nucleus complexes.

  10. Binary Quantum Turbulence Arising from Countersuperflow Instability in Two-Component Bose-Einstein Condensates

    SciTech Connect

    Takeuchi, Hiromitsu; Ishino, Shungo; Tsubota, Makoto

    2010-11-12

    We theoretically study the development of quantum turbulence from two counter-propagating superfluids of miscible Bose-Einstein condensates by numerically solving the coupled Gross-Pitaevskii equations. When the relative velocity exceeds a critical value, the countersuperflow becomes unstable and quantized vortices are nucleated, which leads to isotropic quantum turbulence consisting of two superflows. It is shown that the binary turbulence can be realized experimentally in a trapped system.

  11. Binary quantum turbulence arising from countersuperflow instability in two-component Bose-Einstein condensates.

    PubMed

    Takeuchi, Hiromitsu; Ishino, Shungo; Tsubota, Makoto

    2010-11-12

    We theoretically study the development of quantum turbulence from two counter-propagating superfluids of miscible Bose-Einstein condensates by numerically solving the coupled Gross-Pitaevskii equations. When the relative velocity exceeds a critical value, the countersuperflow becomes unstable and quantized vortices are nucleated, which leads to isotropic quantum turbulence consisting of two superflows. It is shown that the binary turbulence can be realized experimentally in a trapped system.

  12. Characterization of spacecraft humidity condensate

    NASA Technical Reports Server (NTRS)

    Muckle, Susan; Schultz, John R.; Sauer, Richard L.

    1994-01-01

    When construction of Space Station Freedom reaches the Permanent Manned Capability (PMC) stage, the Water Recovery and Management Subsystem will be fully operational such that (distilled) urine, spent hygiene water, and humidity condensate will be reclaimed to provide water of potable quality. The reclamation technologies currently baselined to process these waste waters include adsorption, ion exchange, catalytic oxidation, and disinfection. To ensure that the baseline technologies will be able to effectively remove those compounds presenting a health risk to the crew, the National Research Council has recommended that additional information be gathered on specific contaminants in waste waters representative of those to be encountered on the Space Station. With the application of new analytical methods and the analysis of waste water samples more representative of the Space Station environment, advances in the identification of the specific contaminants continue to be made. Efforts by the Water and Food Analytical Laboratory at JSC were successful in enlarging the database of contaminants in humidity condensate. These efforts have not only included the chemical characterization of condensate generated during ground-based studies, but most significantly the characterization of cabin and Spacelab condensate generated during Shuttle missions. The analytical results presented in this paper will be used to show how the composition of condensate varies amongst enclosed environments and thus the importance of collecting condensate from an environment close to that of the proposed Space Station. Although advances were made in the characterization of space condensate, complete characterization, particularly of the organics, requires further development of analytical methods.

  13. Condensation in Nanoporous Packed Beds.

    PubMed

    Ally, Javed; Molla, Shahnawaz; Mostowfi, Farshid

    2016-05-10

    In materials with tiny, nanometer-scale pores, liquid condensation is shifted from the bulk saturation pressure observed at larger scales. This effect is called capillary condensation and can block pores, which has major consequences in hydrocarbon production, as well as in fuel cells, catalysis, and powder adhesion. In this study, high pressure nanofluidic condensation studies are performed using propane and carbon dioxide in a colloidal crystal packed bed. Direct visualization allows the extent of condensation to be observed, as well as inference of the pore geometry from Bragg diffraction. We show experimentally that capillary condensation depends on pore geometry and wettability because these factors determine the shape of the menisci that coalesce when pore filling occurs, contrary to the typical assumption that all pore structures can be modeled as cylindrical and perfectly wetting. We also observe capillary condensation at higher pressures than has been done previously, which is important because many applications involving this phenomenon occur well above atmospheric pressure, and there is little, if any, experimental validation of capillary condensation at such pressures, particularly with direct visualization.

  14. Epimerization in peptide thioester condensation.

    PubMed

    Teruya, Kenta; Tanaka, Takeyuki; Kawakami, Toru; Akaji, Kenichi; Aimoto, Saburo

    2012-11-01

    Peptide segment couplings are now widely utilized in protein chemical synthesis. One of the key structures for the strategy is the peptide thioester. Peptide thioester condensation, in which a C-terminal peptide thioester is selectively activated by silver ions then condensed with an amino component, is a powerful tool. But the amino acid adjacent to the thioester is at risk of epimerization. During the preparation of peptide thioesters by the Boc solid-phase method, no substantial epimerization of the C-terminal amino acid was detected. Epimerization was, however, observed during a thioester-thiol exchange reaction and segment condensation in DMSO in the presence of a base. In contrast, thioester-thiol exchange reactions in aqueous solutions gave no epimerization. The epimerization during segment condensation was significantly suppressed with a less polar solvent that is applicable to segments in thioester peptide condensation. These results were applied to a longer peptide thioester condensation. The epimer content of the coupling product of 89 residues was reduced from 27% to 6% in a condensation between segments of 45 and 44 residues for the thioester and the amino component, respectively.

  15. Water condensation: a multiscale phenomenon.

    PubMed

    Jensen, Kasper Risgaard; Fojan, Peter; Jensen, Rasmus Lund; Gurevich, Leonid

    2014-02-01

    The condensation of water is a phenomenon occurring in multiple situations in everyday life, e.g., when fog is formed or when dew forms on the grass or on windows. This means that this phenomenon plays an important role within the different fields of science including meteorology, building physics, and chemistry. In this review we address condensation models and simulations with the main focus on heterogeneous condensation of water. The condensation process is, at first, described from a thermodynamic viewpoint where the nucleation step is described by the classical nucleation theory. Further, we address the shortcomings of the thermodynamic theory in describing the nucleation and emphasize the importance of nanoscale effects. This leads to the description of condensation from a molecular viewpoint. Also presented is how the nucleation can be simulated by use of molecular models, and how the condensation process is simulated on the macroscale using computational fluid dynamics. Finally, examples of hybrid models combining molecular and macroscale models for the simulation of condensation on a surface are presented.

  16. Foot-operated cell-counter

    NASA Technical Reports Server (NTRS)

    Eisler, W. J., Jr.; Fry, R. J. M.; Le Buis, D.

    1969-01-01

    Cell-counter for cell indices consists of a footboard with four pressure sensitive switches and an enclosure for the components and circuitry. This device increases the operators efficiency by reducing the number of required hand movements.

  17. Using over-the-counter medicines safely

    MedlinePlus

    ... ency/patientinstructions/000882.htm Using over-the-counter medicines safely To use the sharing features on this ... need to know about OTC drugs. About OTC Medicines You can buy OTC medicines without a prescription ...

  18. Over-the-counter pain relievers

    MedlinePlus

    ... Analgesics; Acetaminophen; NSAID; Nonsteroidal anti-inflammatory drug; Pain medicine - over-the-counter; Pain medicine - OTC ... Pain medicines are also called analgesics. Each kind of pain medicine has benefits and risks. Some types of pain ...

  19. Position sensitive counter development at the linac

    SciTech Connect

    Becker, J.A.

    1981-05-20

    In a novel application of the multiwire proportional counter we have imaged a collimated neutron beam. Although preliminary, the results are of sufficient import to be described here because of the potential wide application of the multiwire proportional counter to Laboratory problems. The counter was operated with a counting gas pressure of 20 Torr; the counting gas was pure C/sub 4/H/sub 10/. The radiator was a /sup 235/U foil. Under these conditions, the counter is (1) relatively insensitive to charged particles (other than fission fragments), (2) insensitive to ..gamma..-radiation, and (3) has an efficiency for the detection of fission fragments independent of incident neutron energy over a wide range of neutron energies.

  20. Steam condenser thermal design theories

    NASA Astrophysics Data System (ADS)

    Davidson, B. J.

    Test data and prediction methods for condensation in steam condenser tube banks are reviewed. Standards for thermal rating; effect of vapor velocity; vapor shear and inundation in tube banks; correction factors to the Nusselt equation; and equations for the combined effect of vapor shear and inundation are discussed. Effects of noncondensible gases; tube side heat transfer; and expressions for combined tube side and shell side heat transfer are considered. Frictional, gravitational, momentum, and pressure drop trends; and the role of access lanes to reduce pressure drop are outlined. Computer models of condensers, including algebraic representations of the field equations, are summarized.

  1. Novel Designs of Quantum Reversible Counters

    NASA Astrophysics Data System (ADS)

    Qi, Xuemei; Zhu, Haihong; Chen, Fulong; Zhu, Junru; Zhang, Ziyang

    2016-11-01

    Reversible logic, as an interesting and important issue, has been widely used in designing combinational and sequential circuits for low-power and high-speed computation. Though a significant number of works have been done on reversible combinational logic, the realization of reversible sequential circuit is still at premature stage. Reversible counter is not only an important part of the sequential circuit but also an essential part of the quantum circuit system. In this paper, we designed two kinds of novel reversible counters. In order to construct counter, the innovative reversible T Flip-flop Gate (TFG), T Flip-flop block (T_FF) and JK flip-flop block (JK_FF) are proposed. Based on the above blocks and some existing reversible gates, the 4-bit binary-coded decimal (BCD) counter and controlled Up/Down synchronous counter are designed. With the help of Verilog hardware description language (Verilog HDL), these counters above have been modeled and confirmed. According to the simulation results, our circuits' logic structures are validated. Compared to the existing ones in terms of quantum cost (QC), delay (DL) and garbage outputs (GBO), it can be concluded that our designs perform better than the others. There is no doubt that they can be used as a kind of important storage components to be applied in future low-power computing systems.

  2. Characteristics of central collision events in Fe-nucleus interactions for 20 - 60 GeV/nucleon

    NASA Technical Reports Server (NTRS)

    Burnett, T. H.; Drake, S.; Derrickson, J. H.; Fountain, W.; Fuki, M.; Gregory, J. C.; Hayashi, T.; Hayashi, T.; Holynski, R.; Iwai, J.; Jones, W. V.

    1985-01-01

    A counter emulsion hybrid chamber in Japanese-American Cooperative Emulsion Experiment (JACEE-3) was flown on a balloon at the altitude (5.4 g/sq cm) in 1982 with the objective of probing the heavy nuclear collisions above 20 GeV per nucleon. In the energy region, it is suggested that nucleus-nucleus collisions provide dense collisions complex through compression and secondary particle production. In the lower energy region, an evidence of collective flow has been reported. And also, at higher energy region, it has been argued that nucleus has rather large stopping power. In this paper, the high multiplicity characteristics of Fe nucleus central collisions with energies 20 to 50 GeV/nucleon are presented. This is considered to be relevant to compressibility and collective flow of nuclear matter.

  3. Higgs and Particle Production in Nucleus-Nucleus Collisions

    NASA Astrophysics Data System (ADS)

    Liu, Zhe

    We apply a diagrammatic approach to study Higgs boson, a color-neutral heavy particle, pro- duction in nucleus-nucleus collisions in the saturation framework without quantum evolution. We assume the strong coupling constant much smaller than one. Due to the heavy mass and colorless nature of Higgs particle, final state interactions are absent in our calculation. In order to treat the two nuclei dynamically symmetric, we use the Coulomb gauge which gives the appropriate light cone gauge for each nucleus. To further eliminate initial state interactions we choose specific prescriptions in the light cone propagators. We start the calculation from only two nucleons in each nucleus and then demonstrate how to generalize the calculation to higher orders diagrammatically. We simplify the diagrams by the Slavnov-Taylor-Ward identities. The resulting cross section is factorized into a product of two Weizsacker-Williams gluon distributions of the two nuclei when the transverse momentum of the produced scalar particle is around the saturation momentum. To our knowledge this is the first process where an exact analytic formula has been formed for a physical process, involving momenta on the order of the saturation momentum, in nucleus-nucleus collisions in the quasi-classical approximation. Since we have performed the calculation in an unconventional gauge choice, we further confirm our results in Feynman gauge where the Weizsacker-Williams gluon distribution is interpreted as a transverse momentum broadening of a hard gluons traversing a nuclear medium. The transverse momentum factorization manifests itself in light cone gauge but not so clearly in Feynman gauge. In saturation physics there are two different unintegrated gluon distributions usually encountered in the literature: the Weizsacker-Williams gluon distribution and the dipole gluon distribution. The first gluon distribution is constructed by solving classical Yang-Mills equation of motion in the Mc

  4. Sign-And-Magnitude Up/Down Counter

    NASA Technical Reports Server (NTRS)

    Cole, Steven W.

    1991-01-01

    Magnitude-and-sign counter includes conventional up/down counter for magnitude part and special additional circuitry for sign part. Negative numbers indicated more directly. Counter implemented by programming erasable programmable logic device (EPLD) or programmable logic array (PLA). Used in place of conventional up/down counter to provide sign and magnitude values directly to other circuits.

  5. Modeling reaction fronts of separated condensed phase reactants

    NASA Astrophysics Data System (ADS)

    Koundinyan, Sushilkumar; Stewart, D. Scott; Matalon, Moshe

    2017-01-01

    We present a Gibbs free energy approach to modeling reaction fronts in condensed phase reactive materials. The current interest is in chemical reactions of condensed phase reactants that are initially separated. In energetic materials such reactions are observed to occur extremely fast and at relatively sharp fronts. The condensed phase combustion process differs in several aspects from classical gaseous combustion due to the disparity between the characteristic thermal conductivity length and the mass diffusion lengths and a volume, temperature, stress, mass fraction equation of state that principally depends only on the component reference volumes and the current mixture composition. To retain a simple planar configuration, we consider the two reactants, in solid phase, are in motion towards each other characterized by counter-flow geometry. We apply the model to a simplified Titanium-Boron system and present the analysis of reaction zone length for various strain rates. The numerical results are validated with asymptotic approximations at the Burke-Schumann (complete combustion) limit.

  6. Condensation heat transfer under a microgravity environment

    NASA Technical Reports Server (NTRS)

    Chow, L. C.

    1986-01-01

    A description of the condensation heat transfer process in microgravity is given. A review of the literature is also reported. The most essential element of condensation heat transfer in microgravity is the condensate removal mechanism. Two mechanisms for condensate removal are analyzed by looking into two problems. The first problem is concerned with film condensation on a flat porous plate with the condensate being removed by suction at the wall. The second problem is an analytical prediction of the heat transfer coefficient for condensing annular flows with the condensate film driven by the vapor shear. It is concluded that both suction and vapor shear can effectively drain the condensate to ensure continuous operation of the condensers operated under a microgravity environment. It is recommended that zero-g flight experiments be carried out to verify the prediction made in the present report. The results contained in this report should also aid in the design of future space condensers.

  7. Monitoring by Control Technique - Condensers

    EPA Pesticide Factsheets

    Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about condenser control techniques used to reduce pollutant emissions.

  8. Flow Boiling and Condensation Experiment

    NASA Video Gallery

    The Flow Boiling and Condensation Experiment is another investigation that examines the flow of a mixture of liquids and the vapors they produce when in contact with hot space system equipment. Coo...

  9. Mixing-height measurement by lidar, particle counter, and rawinsonde in the Williamette Valley, Oregon

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Melfi, S. H.; Olsson, L. E.; Tuft, W. L.; Elliott, W. P.; Egami, R.

    1972-01-01

    The feasibility of using laser radar (lidar) to measure the spatial distribution of aerosols and water vapor in the earth's mixing or boundary layer is shown. From these data the important parameter of actual mixing height was determined, that is, the maximum height to which particulate pollutants actually mix. Data are shown for simultaneous lidar, rawinsonde, and aircraft-mounted condensation nuclei counter and temperature measurements. The synoptic meteorology is also presented. The Williamette Valley, Oregon, was chosen for the measurements because of its unique combination of meteorology, terrain, and pollutant source, along with an ongoing Oregon State University study of the natural ventilation of this valley.

  10. Modular high speed counter employing edge-triggered code

    DOEpatents

    Vanstraelen, G.F.

    1993-06-29

    A high speed modular counter (100) utilizing a novel counting method in which the first bit changes with the frequency of the driving clock, and changes in the higher order bits are initiated one clock pulse after a 0'' to 1'' transition of the next lower order bit. This allows all carries to be known one clock period in advance of a bit change. The present counter is modular and utilizes two types of standard counter cells. A first counter cell determines the zero bit. The second counter cell determines any other higher order bit. Additional second counter cells are added to the counter to accommodate any count length without affecting speed.

  11. Modular high speed counter employing edge-triggered code

    DOEpatents

    Vanstraelen, Guy F.

    1993-06-29

    A high speed modular counter (100) utilizing a novel counting method in which the first bit changes with the frequency of the driving clock, and changes in the higher order bits are initiated one clock pulse after a "0" to "1" transition of the next lower order bit. This allows all carries to be known one clock period in advance of a bit change. The present counter is modular and utilizes two types of standard counter cells. A first counter cell determines the zero bit. The second counter cell determines any other higher order bit. Additional second counter cells are added to the counter to accommodate any count length without affecting speed.

  12. Single nucleon emission in relativistic nucleus-nucleus reactions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Townsend, Lawrence W.

    1992-01-01

    Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parameterized formulas developed by those authors.

  13. Analysis of relativistic nucleus-nucleus interactions in emulsion chambers

    NASA Technical Reports Server (NTRS)

    Mcguire, Stephen C.

    1987-01-01

    The development of a computer-assisted method is reported for the determination of the angular distribution data for secondary particles produced in relativistic nucleus-nucleus collisions in emulsions. The method is applied to emulsion detectors that were placed in a constant, uniform magnetic field and exposed to beams of 60 and 200 GeV/nucleon O-16 ions at the Super Proton Synchrotron (SPS) of the European Center for Nuclear Research (CERN). Linear regression analysis is used to determine the azimuthal and polar emission angles from measured track coordinate data. The software, written in BASIC, is designed to be machine independent, and adaptable to an automated system for acquiring the track coordinates. The fitting algorithm is deterministic, and takes into account the experimental uncertainty in the measured points. Further, a procedure for using the track data to estimate the linear momenta of the charged particles observed in the detectors is included.

  14. Dynamical nucleus-nucleus potential at short distances

    SciTech Connect

    Jiang Yongying; Wang Ning; Li Zhuxia; Scheid, Werner

    2010-04-15

    The dynamical nucleus-nucleus potentials for fusion reactions {sup 40}Ca+{sup 40}Ca, {sup 48}Ca+{sup 208}Pb, and {sup 126}Sn+{sup 130}Te are studied with the improved quantum molecular dynamics model together with the extended Thomas-Fermi approximation for the kinetic energies of nuclei. The obtained fusion barrier for {sup 40}Ca+{sup 40}Ca is in good agreement with the extracted fusion barrier from the measured fusion excitation function, and the depths of the fusion pockets are close to the results of time-dependent Hartree-Fock calculations. The energy dependence of the fusion barrier is also investigated. The fusion pocket becomes shallow for a heavy fusion system and almost disappears for heavy nearly symmetric systems, and the obtained potential at short distances is higher than the adiabatic potential.

  15. Azimuthal correlation and collective behavior in nucleus-nucleus collisions

    SciTech Connect

    Mali, P.; Mukhopadhyay, A. Sarkar, S.; Singh, G.

    2015-03-15

    Various flow effects of nuclear and hadronic origin are investigated in nucleus-nucleus collisions. Nuclear emulsion data collected from {sup 84}Kr + Ag/Br interaction at an incident energy of 1.52 GeV per nucleon and from {sup 28}Si + Ag/Br interaction at an incident energy of 14.5 GeV per nucleon are used in the investigation. The transverse momentum distribution and the flow angle analysis show that collective behavior, like a bounce-off effect of the projectile spectators and a sidesplash effect of the target spectators, are present in our event samples. From an azimuthal angle analysis of the data we also see a direct flow of the projectile fragments and of the produced charged particles. On the other hand, for both data samples the target fragments exhibit a reverse flow, while the projectile fragments exhibit an elliptic flow. Relevant flow parameters are measured.

  16. Complex chromatin condensation patterns and nuclear protein transitions during spermiogenesis: examples from mollusks.

    PubMed

    Chiva, M; Saperas, N; Ribes, E

    2011-12-01

    In this paper we review and analyze the chromatin condensation pattern during spermiogenesis in several species of mollusks. Previously, we had described the nuclear protein transitions during spermiogenesis in these species. The results of our study show two types of condensation pattern: simple patterns and complex patterns, with the following general characteristics: (a) When histones (always present in the early spermatid nucleus) are directly replaced by SNBP (sperm nuclear basic proteins) of the protamine type, the spermiogenic chromatin condensation pattern is simple. However, if the replacement is not direct but through intermediate proteins, the condensation pattern is complex. (b) The intermediate proteins found in mollusks are precursor molecules that are processed during spermiogenesis to the final protamine molecules. Some of these final protamines represent proteins with the highest basic amino acid content known to date, which results in the establishment of a very strong electrostatic interaction with DNA. (c) In some instances, the presence of complex patterns of chromatin condensation clearly correlates with the acquisition of specialized forms of the mature sperm nuclei. In contrast, simple condensation patterns always lead to rounded, oval or slightly cylindrical nuclei. (d) All known cases of complex spermiogenic chromatin condensation patterns are restricted to species with specialized sperm cells (introsperm). At the time of writing, we do not know of any report on complex condensation pattern in species with external fertilization and, therefore, with sperm cells of the primitive type (ect-aquasperm). (e) Some of the mollusk an spermiogenic chromatin condensation patterns of the complex type are very similar (almost identical) to those present in other groups of animals. Interestingly, the intermediate proteins involved in these cases can be very different.In this study, we discuss the biological significance of all these features and

  17. Multi-K¯ nuclei and kaon condensation

    NASA Astrophysics Data System (ADS)

    Gazda, D.; Friedman, E.; Gal, A.; Mareš, J.

    2008-04-01

    We extend previous relativistic mean-field (RMF) calculations of multi-K¯ nuclei, using vector boson fields with SU(3) PPV coupling constants and scalar boson fields constrained phenomenologically. For a given core nucleus, the resulting K¯ separation energy BK¯, as well as the associated nuclear and K¯-meson densities, saturate with the number κ of K¯ mesons for κ>κsat~10. Saturation appears robust against a wide range of variations, including the RMF nuclear model used and the type of boson fields mediating the strong interactions. Because BK¯ generally does not exceed 200 MeV, it is argued that multi-K¯ nuclei do not compete with multihyperonic nuclei in providing the ground state of strange hadronic configurations and that kaon condensation is unlikely to occur in strong-interaction self-bound strange hadronic matter. Last, we explore possibly self-bound strange systems made of neutrons and K¯0 mesons, or protons and K- mesons, and study their properties.

  18. Hummingbird Comet Nucleus Analysis Mission

    NASA Technical Reports Server (NTRS)

    Kojiro, Daniel; Carle, Glenn C.; Lasher, Larry E.

    2000-01-01

    Hummingbird is a highly focused scientific mission, proposed to NASA s Discovery Program, designed to address the highest priority questions in cometary science-that of the chemical composition of the cometary nucleus. After rendezvous with the comet, Hummingbird would first methodically image and map the comet, then collect and analyze dust, ice and gases from the cometary atmosphere to enrich characterization of the comet and support landing site selection. Then, like its namesake, Hummingbird would carefully descend to a pre-selected surface site obtaining a high-resolution image, gather a surface material sample, acquire surface temperature and then immediately return to orbit for detailed chemical and elemental analyses followed by a high resolution post-sampling image of the site. Hummingbird s analytical laboratory contains instrumentation for a comprehensive molecular and elemental analysis of the cometary nucleus as well as an innovative surface sample acquisition device.

  19. Micro-structural Change During Nucleation: From Nucleus To Bicontinuous Morphology

    PubMed Central

    Jeong, Seongmin; Jho, Yongseok; Zhou, Xin

    2015-01-01

    Although the microstructure of coexistence phase provides direct insights of the nucleation mechanism and their change is substantial in the phase transition, their study is limited due to the lack of suitable tools capturing the thermodynamically unstable transient states. We resolve this problem in computational study by introducing a generalized canonical ensemble simulation and investigate the morphological change of the nucleus during the water evaporation and condensation. We find that at very low pressure, where the transition is first order, classical nucleation theory holds approximately. A main nucleus is formed in the supersaturation near spinodal, and the overall shape of the nucleus is finite and compact. On increasing the pressure of the system, more nuclei are formed even before spinodal. They merge into a larger nuclei with a smaller free energy penalty to form ramified shapes. We suggest order parameters to describe the extent of fluctuation, and their relation to the free energy profile. PMID:26526871

  20. Micro-structural Change During Nucleation: From Nucleus To Bicontinuous Morphology

    NASA Astrophysics Data System (ADS)

    Jeong, Seongmin; Jho, Yongseok; Zhou, Xin

    2015-11-01

    Although the microstructure of coexistence phase provides direct insights of the nucleation mechanism and their change is substantial in the phase transition, their study is limited due to the lack of suitable tools capturing the thermodynamically unstable transient states. We resolve this problem in computational study by introducing a generalized canonical ensemble simulation and investigate the morphological change of the nucleus during the water evaporation and condensation. We find that at very low pressure, where the transition is first order, classical nucleation theory holds approximately. A main nucleus is formed in the supersaturation near spinodal, and the overall shape of the nucleus is finite and compact. On increasing the pressure of the system, more nuclei are formed even before spinodal. They merge into a larger nuclei with a smaller free energy penalty to form ramified shapes. We suggest order parameters to describe the extent of fluctuation, and their relation to the free energy profile.

  1. Checkerboard Theory of the Nucleus.

    NASA Astrophysics Data System (ADS)

    Lach, Theodore

    2006-04-01

    The Checker Board Model (CBM) is a 2D model of the nucleus that proposes that the synchronization of the 2 outer rotating quarks in the nucleons accounts for magnetic moment of the nucleons and that the magnetic flux from the nucleons couples (weaves) into the 2D checker board array structures and this magnetic coupling in addition to electrostatic forces of the rotating and stationary quarks accounts for the apparent strong nuclear force. The symmetry of the He nucleus helps explain why this 2D structure is so stable. This model explain the mass of the proton and neutron, along with their magnetic moments and their absolute and relative sizes in terms of the above structure and predict the masses of two newly proposed quarks ^(1): the ``up'' and the ``dn'' quarks. Since the masses of the ``up'' and ``dn'' quark determined by the CBM (237.31 MeV and 42.392 MeV respectively) did not fit within the standard model as candidates for u and d, a new model (New Physics) had to be invented. This new particle physics model predicts that nature has 5 generations not 3. (1). T.M. Lach, Checkerboard Structure of the Nucleus, Infinite Energy, Vol. 5, issue 30, (2000). (2). T.M. Lach, Masses of the Sub-Nuclear Particles, nucl-th/0008026, @http://xxx.lanl.gov/

  2. Advances in shell side condensation for refrigerants

    NASA Astrophysics Data System (ADS)

    Webb, Ralph L.

    The design of shell and tube condensers used in air conditioning and refrigeration applications is discussed. The geometry of interest involves condensation on the shell side of a horizontal tube bundle. Enhanced heat transfer geometries are typically used for condensation on the shell side. The heat transfer is removed by water on the tube side, which typically have tube side enhancement. Single tube and row effect condensation data are presented. Thermal design methods for sizing of the condenser are outlined.

  3. Counter-balanced, multiple cable construction crane

    NASA Astrophysics Data System (ADS)

    Mikulas, Martin M., Jr.; Yang, Li-Farn

    1993-10-01

    The invention is a counter-balanced, multiple cable construction crane. The apparatus for hoisting payloads comprises a crane having a lifting means, the lifting means comprising an end effector means and three suspension means or cables. One end of each cable attaches to a different winding means located on the lifting means, and the other end of each cable attaches to a different point on the end effector, such that the three cables have a theoretical point of convergence with this point corresponding to the center of mass of the payload. Three controls command rotation of the winding means to a predetermined position. Accordingly, the crane provides precise and autonomous positioning of the payload without human guidance. The crane further comprises a counter-balancing means. Two controls position the counter-balancing means to offset the overturning moment which arises during the lifting of heavy payloads.

  4. Counter-balanced, multiple cable construction crane

    NASA Astrophysics Data System (ADS)

    Mikulas, Martin M., Jr.; Yang, Li-Farn

    1991-11-01

    The invention is a counter-balanced, multiple cable construction crane. The apparatus for hoisting payloads comprises a crane having a lifting means, the lifting means comprising an end effector means and three suspension means or cables. One end of each cable attaches to a different winding means located on the lifting means, and the other end of each cable attaches to a different point on the end effector, such that the three cables have a theoretical point of convergence with this point corresponding to the center of mass of the payload. Three controls command rotation of the winding means to a predetermined position. Accordingly, the crane provides precise and autonomous positioning of the payload without human guidance. The crane further comprises a counter-balancing means. Two controls position the counter-balancing means to offset the overturning moment which arises during the lifting of heavy payloads.

  5. Counter-balanced, multiple cable construction crane

    NASA Technical Reports Server (NTRS)

    Mikulas, Martin M., Jr. (Inventor); Yang, Li-Farn (Inventor)

    1993-01-01

    The invention is a counter-balanced, multiple cable construction crane. The apparatus for hoisting payloads comprises a crane having a lifting means, the lifting means comprising an end effector means and three suspension means or cables. One end of each cable attaches to a different winding means located on the lifting means, and the other end of each cable attaches to a different point on the end effector, such that the three cables have a theoretical point of convergence with this point corresponding to the center of mass of the payload. Three controls command rotation of the winding means to a predetermined position. Accordingly, the crane provides precise and autonomous positioning of the payload without human guidance. The crane further comprises a counter-balancing means. Two controls position the counter-balancing means to offset the overturning moment which arises during the lifting of heavy payloads.

  6. An energy-dependent numerical model for the condensation probability, γj

    NASA Astrophysics Data System (ADS)

    Kerby, Leslie M.

    2017-04-01

    The "condensation" probability, γj, is an important variable in the preequilibrium stage of nuclear spallation reactions. It represents the probability that pj excited nucleons (excitons) will "condense" to form complex particle type j in the excited residual nucleus. It has a significant impact on the emission width, or probability of emitting fragment type j from the residual nucleus. Previous formulations for γj were energy-independent and valid for fragments up to 4He only. This paper explores the formulation of a new model for γj, one which is energy-dependent and valid for up to 28Mg, and which provides improved fits compared to experimental fragment spectra.

  7. Bose-Einstein condensate strings

    NASA Astrophysics Data System (ADS)

    Harko, Tiberiu; Lake, Matthew J.

    2015-02-01

    We consider the possible existence of gravitationally bound general relativistic strings consisting of Bose-Einstein condensate (BEC) matter which is described, in the Newtonian limit, by the zero temperature time-dependent nonlinear Schrödinger equation (the Gross-Pitaevskii equation), with repulsive interparticle interactions. In the Madelung representation of the wave function, the quantum dynamics of the condensate can be formulated in terms of the classical continuity equation and the hydrodynamic Euler equations. In the case of a condensate with quartic nonlinearity, the condensates can be described as a gas with two pressure terms, the interaction pressure, which is proportional to the square of the matter density, and the quantum pressure, which is without any classical analogue, though, when the number of particles in the system is high enough, the latter may be neglected. Assuming cylindrical symmetry, we analyze the physical properties of the BEC strings in both the interaction pressure and quantum pressure dominated limits, by numerically integrating the gravitational field equations. In this way we obtain a large class of stable stringlike astrophysical objects, whose basic parameters (mass density and radius) depend sensitively on the mass and scattering length of the condensate particle, as well as on the quantum pressure of the Bose-Einstein gas.

  8. Polariton condensates at room temperature

    NASA Astrophysics Data System (ADS)

    Guillet, Thierry; Brimont, Christelle

    2016-10-01

    We review the recent developments of the polariton physics in microcavities featuring the exciton-photon strong coupling at room temperature, and leading to the achievement of room-temperature polariton condensates. Such cavities embed active layers with robust excitons that present a large binding energy and a large oscillator strength, i.e. wide bandgap inorganic or organic semiconductors, or organic molecules. These various systems are compared, in terms of figures of merit and of common features related to their strong oscillator strength. The various demonstrations of polariton laser are compared, as well as their condensation phase diagrams. The room-temperature operation indeed allows a detailed investigation of the thermodynamic and out-of-equilibrium regimes of the condensation process. The crucial role of the spatial dynamics of the condensate formation is discussed, as well as the debated issue of the mechanism of stimulated relaxation from the reservoir to the condensate under non-resonant excitation. Finally the prospects of polariton devices are presented.

  9. Neutron spectrometry with He-3 proportional counters

    SciTech Connect

    Manolopoulou, M.; Fragopoulou, M.; Stoulos, S.; Vagena, E.; Westmeier, W.; Zamani, M.

    2011-07-01

    Helium filled proportional counters are widely used in the field of neutron detection and spectrometry. In this work the response of a commercially available He-3 counter is studied experimentally and calculated with Monte Carlo for the neutron energy range from 230 keV up to about 7 MeV. The calculated response of the system is used to determine neutron yield energy distribution emitted from an extended {sup nat}U/Pb assembly irradiated with 1.6 GeV deuterons. The results are in acceptable agreement with the calculated neutron distribution with DCM-DEM code. (authors)

  10. High-speed counter-current chromatographic separation of phytosterols.

    PubMed

    Schröder, Markus; Vetter, Walter

    2011-07-01

    Phytosterols are bioactive compounds which occur in low concentrations in plant oils. Due to their beneficial effects on human health, phytosterols have already been supplemented to food. Commercial phytosterol standards show insufficient purity and/or are very expensive. In this study, we developed a high-speed counter-current chromatography (HSCCC) method for the fractionation and analysis of a commercial crude β-sitosterol standard (purity ∼60% according to supplier). Different solvent systems were tested in shake-flask experiments, and the system n-hexane/methanol/aqueous silver nitrate solution (34/24/1, v/v/v) was finally used for HSCCC fractionation. About 50 mg phytosterols was injected and distributed into 57 fractions. Selected fractions were condensed and re-injected into the HSCCC system. This measure provided pure sitostanol (>99%) and β-sitosterol (∼99%), as well as a mixture of campesterol and stigmasterol without further phytosterols. An enriched HSCCC fraction facilitated the mass spectrometric analysis of further 11 minor phytosterols (after trimethylsilylation). It was also shown that the commercial product contained about 0.3% carotinoids which eluted without delay into an early HSCCC fraction and which were separated from the phytosterols.

  11. Classifiers for centrality determination in proton-nucleus and nucleus-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Altsybeev, Igor; Kovalenko, Vladimir

    2017-03-01

    Centrality, as a geometrical property of the collision, is crucial for the physical interpretation of nucleus-nucleus and proton-nucleus experimental data. However, it cannot be directly accessed in event-by-event data analysis. Common methods for centrality estimation in A-A and p-A collisions usually rely on a single detector (either on the signal in zero-degree calorimeters or on the multiplicity in some semi-central rapidity range). In the present work, we made an attempt to develop an approach for centrality determination that is based on machine-learning techniques and utilizes information from several detector subsystems simultaneously. Different event classifiers are suggested and evaluated for their selectivity power in terms of the number of nucleons-participants and the impact parameter of the collision. Finer centrality resolution may allow to reduce impact from so-called volume fluctuations on physical observables being studied in heavy-ion experiments like ALICE at the LHC and fixed target experiment NA61/SHINE on SPS.

  12. Photoproduction of lepton pairs in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies

    SciTech Connect

    Moreira, B. D.; Goncalves, V. P.; De Santana Amaral, J. T.

    2013-03-25

    In this contribution we study coherent interactions as a probe of the nonlinear effects in the Quantum Electrodynamics (QED). In particular, we study the multiphoton effects in the production of leptons pairs for proton-nucleus and nucleus-nucleus collisions for heavy nuclei. In the proton-nucleus we assume the ultrarelativistic proton as a source of photons and estimate the photoproduction of lepton pairs on nuclei at RHIC and LHC energies considering the multiphoton effects associated to multiple rescattering of the projectile photon on the proton of the nucleus. In nucleus - nucleus colllisions we consider the two nuclei as a source of photons. As each scattering contributes with a factor {alpha}Z to the cross section, this contribution must be taken into account for heavy nuclei. We consider the Coulomb corrections to calculate themultiple scatterings and estimate the total cross section for muon and tau pair production in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies.

  13. Spacecraft Crew Cabin Condensation Control

    NASA Technical Reports Server (NTRS)

    Carrillo, Laurie Y.; Rickman, Steven L.; Ungar, Eugene K.

    2013-01-01

    A report discusses a new technique to prevent condensation on the cabin walls of manned spacecraft exposed to the cold environment of space, as such condensation could lead to free water in the cabin. This could facilitate the growth of mold and bacteria, and could lead to oxidation and weakening of the cabin wall. This condensation control technique employs a passive method that uses spacecraft waste heat as the primary wallheating mechanism. A network of heat pipes is bonded to the crew cabin pressure vessel, as well as the pipes to each other, in order to provide for efficient heat transfer to the cabin walls and from one heat pipe to another. When properly sized, the heat-pipe network can maintain the crew cabin walls at a nearly uniform temperature. It can also accept and distribute spacecraft waste heat to maintain the pressure vessel above dew point.

  14. Condensed Astatine: Monatomic and Metallic

    NASA Astrophysics Data System (ADS)

    Hermann, Andreas; Hoffmann, Roald; Ashcroft, N. W.

    2013-09-01

    The condensed matter properties of the nominal terminating element of the halogen group with atomic number 85, astatine, are as yet unknown. In the intervening more than 70 years since its discovery significant advances have been made in substrate cooling and the other techniques necessary for the production of the element to the point where we might now enquire about the key properties astatine might have if it attained a condensed phase. This subject is addressed here using density functional theory and structural selection methods, with an accounting for relativistic physics that is essential. Condensed astatine is predicted to be quite different in fascinating ways from iodine, being already at 1 atm a metal, and monatomic at that, and possibly a superconductor (as is dense iodine).

  15. Condensed astatine: monatomic and metallic.

    PubMed

    Hermann, Andreas; Hoffmann, Roald; Ashcroft, N W

    2013-09-13

    The condensed matter properties of the nominal terminating element of the halogen group with atomic number 85, astatine, are as yet unknown. In the intervening more than 70 years since its discovery significant advances have been made in substrate cooling and the other techniques necessary for the production of the element to the point where we might now enquire about the key properties astatine might have if it attained a condensed phase. This subject is addressed here using density functional theory and structural selection methods, with an accounting for relativistic physics that is essential. Condensed astatine is predicted to be quite different in fascinating ways from iodine, being already at 1 atm a metal, and monatomic at that, and possibly a superconductor (as is dense iodine).

  16. Neuroamine condensations in human subjects.

    PubMed

    Collins, M A

    1980-01-01

    Non-enzymatic products of neuroamines and endogenous carbonyl compounds are apparent "normal" products in human metabolism, and their levels become increased during pathological conditions. DA condensation products--salsolinol, its O-methylated derivative, and methylated derivatives of 1-carboxyl-THP--are found normally in human urine, and the last TIQ is in human brain. Potential beta-carboline condensation products also occur in (aging) human lens tissue. Chronic drinking in alcoholics causes significant increases in urinary salsolinol and O-methyl-salsolinol, presumably due to the increased AcH which is made available. L-DOPA therapy (in Parkinson's disease) elevates urinary and tissue levels of the carboxylated THP derivatives, as well as of salsolinol and THP itself; hyperphenylalaninemia during PKU also increases tissue levels of a DA/phenylpyruvate-derived TIQ and an imine condensate of phenylethylamine and vitamin B6. These unusual products may interfere with neural dynamic processes, and produce cytotoxic metabolites.

  17. Introduction. Cosmology meets condensed matter.

    PubMed

    Kibble, T W B; Pickett, G R

    2008-08-28

    At first sight, low-temperature condensed-matter physics and early Universe cosmology seem worlds apart. Yet, in the last few years a remarkable synergy has developed between the two. It has emerged that, in terms of their mathematical description, there are surprisingly close parallels between them. This interplay has been the subject of a very successful European Science Foundation (ESF) programme entitled COSLAB ('Cosmology in the Laboratory') that ran from 2001 to 2006, itself built on an earlier ESF network called TOPDEF ('Topological Defects: Non-equilibrium Field Theory in Particle Physics, Condensed Matter and Cosmology'). The articles presented in this issue of Philosophical Transactions A are based on talks given at the Royal Society Discussion Meeting 'Cosmology meets condensed matter', held on 28 and 29 January 2008. Many of the speakers had participated earlier in the COSLAB programme, but the strength of the field is illustrated by the presence also of quite a few new participants.

  18. Scrutinizing the pion condensed phase

    NASA Astrophysics Data System (ADS)

    Carignano, Stefano; Lepori, Luca; Mammarella, Andrea; Mannarelli, Massimo; Pagliaroli, Giulia

    2017-02-01

    When the isospin chemical potential exceeds the pion mass, charged pions condense in the zero-momentum state forming a superfluid. Chiral perturbation theory provides a very powerful tool for studying this phase. However, the formalism that is usually employed in this context does not clarify various aspects of the condensation mechanism and makes the identification of the soft modes problematic. We re-examine the pion condensed phase using different approaches within the chiral perturbation theory framework. As a first step, we perform a low-density expansion of the chiral Lagrangian valid close to the onset of the Bose-Einstein condensation. We obtain an effective theory that can be mapped to a Gross-Pitaevskii Lagrangian in which, remarkably, all the coefficients depend on the isospin chemical potential. The low-density expansion becomes unreliable deep in the pion condensed phase. For this reason, we develop an alternative field expansion deriving a low-energy Lagrangian analog to that of quantum magnets. By integrating out the "radial" fluctuations we obtain a soft Lagrangian in terms of the Nambu-Goldstone bosons arising from the breaking of the pion number symmetry. Finally, we test the robustness of the second-order transition between the normal and the pion condensed phase when next-to-leading-order chiral corrections are included. We determine the range of parameters for turning the second-order phase transition into a first-order one, finding that the currently accepted values of these corrections are unlikely to change the order of the phase transition.

  19. On the onset of surface condensation: formation and transition mechanisms of condensation mode

    PubMed Central

    Sheng, Qiang; Sun, Jie; Wang, Qian; Wang, Wen; Wang, Hua Sheng

    2016-01-01

    Molecular dynamics simulations have been carried out to investigate the onset of surface condensation. On surfaces with different wettability, we snapshot different condensation modes (no-condensation, dropwise condensation and filmwise condensation) and quantitatively analyze their characteristics by temporal profiles of surface clusters. Two different types of formation of nanoscale droplets are identified, i.e. the formations with and without film-like condensate. We exhibit the effect of surface tensions on the formations of nanoscale droplets and film. We reveal the formation mechanisms of different condensation modes at nanoscale based on our simulation results and classical nucleation theory, which supplements the ‘classical hypotheses’ of the onset of dropwise condensation. We also reveal the transition mechanism between different condensation modes based on the competition between surface tensions and reveal that dropwise condensation represents the transition states from no-condensation to filmwise condensation. PMID:27481071

  20. On the onset of surface condensation: formation and transition mechanisms of condensation mode.

    PubMed

    Sheng, Qiang; Sun, Jie; Wang, Qian; Wang, Wen; Wang, Hua Sheng

    2016-08-02

    Molecular dynamics simulations have been carried out to investigate the onset of surface condensation. On surfaces with different wettability, we snapshot different condensation modes (no-condensation, dropwise condensation and filmwise condensation) and quantitatively analyze their characteristics by temporal profiles of surface clusters. Two different types of formation of nanoscale droplets are identified, i.e. the formations with and without film-like condensate. We exhibit the effect of surface tensions on the formations of nanoscale droplets and film. We reveal the formation mechanisms of different condensation modes at nanoscale based on our simulation results and classical nucleation theory, which supplements the 'classical hypotheses' of the onset of dropwise condensation. We also reveal the transition mechanism between different condensation modes based on the competition between surface tensions and reveal that dropwise condensation represents the transition states from no-condensation to filmwise condensation.

  1. Long-lived Dark Solitons in Ring-Trap Condensates

    NASA Astrophysics Data System (ADS)

    Proukakis, Nick; Gallucci, Donatello

    2016-05-01

    We demonstrate the feasibility of generation of quasi-stable counter-propagating solitonic structures in an atomic Bose-Einstein condensate confined in a realistic toroidal geometry, and identify optimal parameter regimes for their experimental observation. Using density engineering we numerically identify distinct regimes of motion of the emerging macroscopic excitations, including both solitonic motion along the azimuthal ring direction, such that structures remain visible after multiple collisions even in the presence of thermal fluctuations, and snaking instabilities leading to the decay of the excitations into vortical structures. Our analysis, which considers both mean field effects and fluctuations, is based on the JQC ring trap geometry. Funding: EPSRC (Grants No. EP/I019413/1 and EP/K03250X/1).

  2. Condensed Matter Physics - Biology Resonance

    NASA Astrophysics Data System (ADS)

    Baskaran, G.

    The field of condensed matter physics had its genesis this century and it has had a remarkable evolution. A closer look at its growth reveals a hidden aim in the collective consciousness of the field - a part of the development this century is a kind of warm up exercise to understand the nature of living condensed matter, namely the field of biology, by a growing new breed of scientists in the coming century. Through some examples the vitality of this interaction will be pointed out.

  3. Tripol condensate polishing - operational experience

    SciTech Connect

    Swainsbury, D.

    1995-01-01

    This paper gives a brief outline of the Mission Energy Management Australia Company who operate and maintain the Loy Yang B Power Station in the Latrobe Valley, Victoria, Australia. Details of the plant configuration, the water/steam circuit and cycle chemistry are discussed. The arrangement of the TRIPOL Condensate Polishing Plant and it`s operational modes are examined. Results of the first twelve months operation of the TRIPOL plant are detailed. Levels of crud removal during early commissioning phases employing the pre-filter are presented. Typical parameters achieved during a simulated condenser leak and an operational run beyond the ammonia break point are also documented.

  4. Andreev Reflection in Bosonic Condensates

    SciTech Connect

    Zapata, I.; Sols, F.

    2009-05-08

    We study the bosonic analog of Andreev reflection at a normal-superfluid interface where the superfluid is a boson condensate. We model the normal region as a zone where nonlinear effects can be neglected. Against the background of a decaying condensate, we identify a novel contribution to the current of reflected atoms. The group velocity of this Andreev reflected component differs from that of the normally reflected one. For a three-dimensional planar or two-dimensional linear interface Andreev reflection is neither specular nor conjugate.

  5. Exceptionally bright, compact starburst nucleus

    SciTech Connect

    Margon, B.; Anderson, S.F.; Mateo, M.; Fich, M.; Massey, P.

    1988-11-01

    Observations are reported of a remarkably bright (V about 13) starburst nucleus, 0833 + 652, which has been detected at radio, infrared, optical, ultraviolet, and X-ray wavelengths. Despite an observed flux at each of these wavelengths which is comparable to that of NGC 7714, often considered the 'prototypical' example of the starburst phenomenon, 0833 + 652 appears to be a previously uncataloged object. Its ease of detectability throughout the electromagnetic spectrum should make it useful for a variety of problems in the study of compact emission-line galaxies. 30 references.

  6. Nucleus morphology of Comet Halley

    NASA Technical Reports Server (NTRS)

    Reitsema, H. J.; Delamere, W. A.; Huebner, W. F.; Keller, H. U.; Schmidt, W. K. H.; Wilhelm, K.; Schmidt, H. U.; Whipple, Fred L.

    1986-01-01

    Images obtained by the Halley multicolor camera were used to determine the projected size and shape of the nucleus. The location of the terminator and numerous surface features were determined. There is good correlation between the brightest surface features and the dust jets; however, many bright features are seen which are not associated with jets. Most of the observed features are circular and appear to be related to surface elevation. The angularity of the terminator gives an indication of the three-dimensional structure of the face which was observed.

  7. High School Equivalency as Counter-Space

    ERIC Educational Resources Information Center

    Schwartz, Joni

    2014-01-01

    This chapter is based on the findings of an ethnographic study of an urban General Education Development (GED®) program and suggests that, for some marginalized African American and other young men of color, adult education programs are counter-spaces (Yosso, Ceja, Smith, & Solorzano, [Yosso, T., 2009]) of spatial justice in opposition to…

  8. Diasporic Philosophy, Counter-Education and Improvisation

    ERIC Educational Resources Information Center

    Gur-Ze'ev, Ilan

    2010-01-01

    Counter-education that addresses seriously the challenge of loss, exile, and the deceiving "home-returning" projects accepts that no positive Utopia awaits us as "truth", "genuine life", "worthy struggle", "pleasure" or worthy self-annihilation. Loss is not to be recovered or compensated; not for the individual nor for any kind of "we". And yet,…

  9. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    SciTech Connect

    Cayatte, V.; Sauty, C.; Vlahakis, N.; Tsinganos, K.; Matsakos, T.; Lima, J. J. G.

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  10. Educator Response to the Counter Culture.

    ERIC Educational Resources Information Center

    Loken, Joel

    Differences in political attitudes, opinions, and responses toward the counter culture exist among educators of the right, the new and old left, and conservative, liberal and radical outlooks. Differences in response to student radicalism and dissent involve the function of the school system and its teachers, the nature of the students' role in…

  11. Effectiveness of a Television Counter Advertisement.

    ERIC Educational Resources Information Center

    Lull, James T.; Mulac, Anthony

    This paper investigates the potential effectiveness of counter advertising in influencing the buying habits of a convinced audience. One month before the actual study, 109 subjects indicated a brand preference in a consumer questionnaire. The subjects were randomly assigned to groups that viewed one of the following: (1) a pro-Bayer aspirin…

  12. COUNTER-REVOLUTION IN FOREIGN LANGUAGE TEACHING.

    ERIC Educational Resources Information Center

    HOCKING, ELTON

    THE AUTHOR STATES THAT THE AUDIOLINGUAL REVOLUTION IS BEING SUBJECTED TO A COUNTER-REVOLUTION IS APPARENT IN SUCH RECENT DEVELOPMENTS AS THE 1966 NORTHEAST CONFERENCE, WHEN CARROLL, FERGUSON, AND CHOMSKY DENIED THAT PSYCHOLOGY AND LINGUISTICS PROVIDE DIRECT SUPPORT FOR AUDIOLINGUAL TEACHING, THE WRITINGS OF RIVERS, HAYES, BELASCO, AND VALDMAN WHO…

  13. Tracing the origin of azimuthal gluon correlations in the color glass condensate

    SciTech Connect

    Lappi, T.; Schenke, B.; Schlichting, S.; Venugopalan, R.

    2016-01-11

    Here we examine the origins of azimuthal correlations observed in high energy proton-nucleus collisions by considering the simple example of the scattering of uncorrelated partons off color fields in a large nucleus. We demonstrate how the physics of fluctuating color fields in the color glass condensate (CGC) effective theory generates these azimuthal multiparticle correlations and compute the corresponding Fourier coefficients vn within different CGC approximation schemes. We discuss in detail the qualitative and quantitative differences between the different schemes. Lastly, we will show how a recently introduced color field domain model that captures key features of the observed azimuthal correlations can be understood in the CGC effective theory as a model of non-Gaussian correlations in the target nucleus.

  14. Tracing the origin of azimuthal gluon correlations in the color glass condensate

    DOE PAGES

    Lappi, T.; Schenke, B.; Schlichting, S.; ...

    2016-01-11

    Here we examine the origins of azimuthal correlations observed in high energy proton-nucleus collisions by considering the simple example of the scattering of uncorrelated partons off color fields in a large nucleus. We demonstrate how the physics of fluctuating color fields in the color glass condensate (CGC) effective theory generates these azimuthal multiparticle correlations and compute the corresponding Fourier coefficients vn within different CGC approximation schemes. We discuss in detail the qualitative and quantitative differences between the different schemes. Lastly, we will show how a recently introduced color field domain model that captures key features of the observed azimuthal correlationsmore » can be understood in the CGC effective theory as a model of non-Gaussian correlations in the target nucleus.« less

  15. Visualization of early chromosome condensation

    PubMed Central

    Kireeva, Natashe; Lakonishok, Margot; Kireev, Igor; Hirano, Tatsuya; Belmont, Andrew S.

    2004-01-01

    Current models of mitotic chromosome structure are based largely on the examination of maximally condensed metaphase chromosomes. Here, we test these models by correlating the distribution of two scaffold components with the appearance of prophase chromosome folding intermediates. We confirm an axial distribution of topoisomerase IIα and the condensin subunit, structural maintenance of chromosomes 2 (SMC2), in unextracted metaphase chromosomes, with SMC2 localizing to a 150–200-nm-diameter central core. In contrast to predictions of radial loop/scaffold models, this axial distribution does not appear until late prophase, after formation of uniformly condensed middle prophase chromosomes. Instead, SMC2 associates throughout early and middle prophase chromatids, frequently forming foci over the chromosome exterior. Early prophase condensation occurs through folding of large-scale chromatin fibers into condensed masses. These resolve into linear, 200–300-nm-diameter middle prophase chromatids that double in diameter by late prophase. We propose a unified model of chromosome structure in which hierarchical levels of chromatin folding are stabilized late in mitosis by an axial “glue.” PMID:15353545

  16. Magnetofermionic condensate in two dimensions

    PubMed Central

    Kulik, L. V.; Zhuravlev, A. S.; Dickmann, S.; Gorbunov, A. V.; Timofeev, V. B.; Kukushkin, I. V.; Schmult, S.

    2016-01-01

    Coherent condensate states of particles obeying either Bose or Fermi statistics are in the focus of interest in modern physics. Here we report on condensation of collective excitations with Bose statistics, cyclotron magnetoexcitons, in a high-mobility two-dimensional electron system in a magnetic field. At low temperatures, the dense non-equilibrium ensemble of long-lived triplet magnetoexcitons exhibits both a drastic reduction in the viscosity and a steep enhancement in the response to the external electromagnetic field. The observed effects are related to formation of a super-absorbing state interacting coherently with the electromagnetic field. Simultaneously, the electrons below the Fermi level form a super-emitting state. The effects are explicable from the viewpoint of a coherent condensate phase in a non-equilibrium system of two-dimensional fermions with a fully quantized energy spectrum. The condensation occurs in the space of vectors of magnetic translations, a property providing a completely new landscape for future physical investigations. PMID:27848969

  17. Linker DNA destabilizes condensed chromatin.

    PubMed

    Green, G R; Ferlita, R R; Walkenhorst, W F; Poccia, D L

    2001-01-01

    The contribution of the linker region to maintenance of condensed chromatin was examined in two model systems, namely sea urchin sperm nuclei and chicken red blood cell nuclei. Linkerless nuclei, prepared by extensive digestion with micrococcal nuclease, were compared with Native nuclei using several assays, including microscopic appearance, nuclear turbidity, salt stability, and trypsin resistance. Chromatin in the Linkerless nuclei was highly condensed, resembling pyknotic chromatin in apoptotic cells. Linkerless nuclei were more stable in low ionic strength buffers and more resistant to trypsin than Native nuclei. Analysis of histones from the trypsinized nuclei by polyacrylamide gel electrophoresis showed that specific histone H1, H2B, and H3 tail regions stabilized linker DNA in condensed nuclei. Thermal denaturation of soluble chromatin preparations from differentially trypsinized sperm nuclei demonstrated that the N-terminal regions of histones Sp H1, Sp H2B, and H3 bind tightly to linker DNA, causing it to denature at a high temperature. We conclude that linker DNA exerts a disruptive force on condensed chromatin structure which is counteracted by binding of specific histone tail regions to the linker DNA. The inherent instability of the linker region may be significant in all eukaryotic chromatins and may promote gene activation in living cells.

  18. Magnetofermionic condensate in two dimensions.

    PubMed

    Kulik, L V; Zhuravlev, A S; Dickmann, S; Gorbunov, A V; Timofeev, V B; Kukushkin, I V; Schmult, S

    2016-11-16

    Coherent condensate states of particles obeying either Bose or Fermi statistics are in the focus of interest in modern physics. Here we report on condensation of collective excitations with Bose statistics, cyclotron magnetoexcitons, in a high-mobility two-dimensional electron system in a magnetic field. At low temperatures, the dense non-equilibrium ensemble of long-lived triplet magnetoexcitons exhibits both a drastic reduction in the viscosity and a steep enhancement in the response to the external electromagnetic field. The observed effects are related to formation of a super-absorbing state interacting coherently with the electromagnetic field. Simultaneously, the electrons below the Fermi level form a super-emitting state. The effects are explicable from the viewpoint of a coherent condensate phase in a non-equilibrium system of two-dimensional fermions with a fully quantized energy spectrum. The condensation occurs in the space of vectors of magnetic translations, a property providing a completely new landscape for future physical investigations.

  19. Approaching Bose-Einstein Condensation

    ERIC Educational Resources Information Center

    Ferrari, Loris

    2011-01-01

    Bose-Einstein condensation (BEC) is discussed at the level of an advanced course of statistical thermodynamics, clarifying some formal and physical aspects that are usually not covered by the standard pedagogical literature. The non-conventional approach adopted starts by showing that the continuum limit, in certain cases, cancels out the crucial…

  20. Magnetofermionic condensate in two dimensions

    NASA Astrophysics Data System (ADS)

    Kulik, L. V.; Zhuravlev, A. S.; Dickmann, S.; Gorbunov, A. V.; Timofeev, V. B.; Kukushkin, I. V.; Schmult, S.

    2016-11-01

    Coherent condensate states of particles obeying either Bose or Fermi statistics are in the focus of interest in modern physics. Here we report on condensation of collective excitations with Bose statistics, cyclotron magnetoexcitons, in a high-mobility two-dimensional electron system in a magnetic field. At low temperatures, the dense non-equilibrium ensemble of long-lived triplet magnetoexcitons exhibits both a drastic reduction in the viscosity and a steep enhancement in the response to the external electromagnetic field. The observed effects are related to formation of a super-absorbing state interacting coherently with the electromagnetic field. Simultaneously, the electrons below the Fermi level form a super-emitting state. The effects are explicable from the viewpoint of a coherent condensate phase in a non-equilibrium system of two-dimensional fermions with a fully quantized energy spectrum. The condensation occurs in the space of vectors of magnetic translations, a property providing a completely new landscape for future physical investigations.

  1. Sinus Pain: Can Over-the-Counter Medications Help?

    MedlinePlus

    ... Near You Sinus Pain: Can Over-the-Counter Medications Help? Sinus Pain: Can Over-the-Counter Medications ... OTC) medications. What Is The Role Of OTC Medication For Sinus Pain? There are many different OTC ...

  2. DNA condensates organized by the capsid protein VP15 in White Spot Syndrome Virus.

    PubMed

    Liu, Yingjie; Wu, Jinlu; Chen, Hu; Hew, Choy Leong; Yan, Jie

    2010-12-20

    The White Spot Syndrome Virus (WSSV) has a large circular double-stranded DNA genome of around 300kb and it replicates in the nucleus of the host cells. The machinery of how the viral DNA is packaged has been remained unclear. VP15, a highly basic protein, is one of the major capsid proteins found in the virus. Previously, it was shown to be a DNA binding protein and was hypothesized to participate in the viral DNA packaging process. Using Atomic Force Microscopy imaging, we show that the viral DNA is associated with a (or more) capsid proteins. The organized viral DNA qualitatively resembles the conformations of VP15 induced DNA condensates in vitro. Furthermore, single-DNA manipulation experiments revealed that VP15 is able to condense single DNA against forces of a few pico Newtons. Our results suggest that VP15 may aid in the viral DNA packaging process by directly condensing DNA.

  3. Effects of aerosol organics on cloud condensation nucleus (CCN) concentration and first indirect aerosol effect

    SciTech Connect

    Wang, J. X.; Lee, Y.- N.; Daum, Peter H.; Jayne, John T.; Alexander, M. L.

    2008-11-03

    Abstract. Aerosol microphysics, chemical composition, and CCN properties were measured on the Department of Energy Gulfstream-1 aircraft during the Marine Stratus/ Stratocumulus Experiment (MASE) conducted over the coastal waters between Point Reyes National Seashore and Monterey Bay, California, in July 2005. Aerosols measured during MASE included free tropospheric aerosols, marine boundary layer aerosols, and aerosols with high organic concentration within a thin layer above the cloud. Closure analysis was carried out for all three types of aerosols by comparing the measured CCN concentrations at 0.2% supersaturation to those predicted based on size distribution and chemical composition using K¨ohler theory. The effect of aerosol organic species on predicted CCN concentration was examined using a single hygroscopicity parameterization.

  4. Heavy nucleus collisions between 20 and 60 GeV/nucleon

    NASA Technical Reports Server (NTRS)

    Burnett, T. H.; Dake, S.; Fuki, M.; Gregory, J. C.; Hayashi, T.; Holynski, R.; Iwai, J.; Jones, W. V.; Jurak, A.; Lord, J. J.

    1985-01-01

    Interest in studying relativistic nucleus-nucleus interations arises from the fact that they offer an opportunity to probe nuclear matter at high density and temperature. It is expected that under such extreme conditions a transition from hadronic matter into quark-gluon plasma occurs and that in the interactions of highly relativistic nuclei such conditions are created. Cosmic rays remain a unique source of high energy heavy nuclei. The Japanese-American Cooperative Emulsion Experiment (JACEE-3) was designed to study the collisions of heavy cosmic ray nuclei with different nuclear targets at energies beyond 20 GeV/nucleon. JACEE-3 experiment was carried out using a combined electronic counters and an emulsion chamber detector, which was exposed to the cosmic rays on a balloon at an altitude of 5 g/sq cm.

  5. Internally drained condenser for spacecraft thermal management

    NASA Technical Reports Server (NTRS)

    Valenzuela, Javier A.; Drew, Brian C.

    1989-01-01

    This paper presents the results obtained to date in a program to develop a high heat flux condenser for use in two-phase spacecraft thermal management loops. The objective is to obtain a several fold increase in condensation heat transfer coefficient over those which can be achieved with shear-controlled or capillary-wick condensers. The internally drained condenser relies on shaped fins to develop a capillary pressure gradient over the surface of the fins and drive the condensate toward narrow drainage grooves separating the fins. The condensate then flows through a drainage network embedded in the condenser walls. Heat transfer coefficients of up to 8 W/sq cm C were measured in steam, providing a heat transfer enhancement ratio greater than a factor of 8. In the paper the proof-of-concept experiments are described and simplified models to predict the performance of the internally drained condenser are presented.

  6. 21 CFR 892.1130 - Nuclear whole body counter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear whole body counter. 892.1130 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1130 Nuclear whole body counter. (a) Identification. A nuclear whole body counter is a device intended to measure the amount of radionuclides in...

  7. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated cell counter. 864.5200 Section 864.5200....5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or semi-automated device used to count red blood cells, white blood cells, or blood platelets using a sample of...

  8. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated cell counter. 864.5200 Section 864.5200....5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or semi-automated device used to count red blood cells, white blood cells, or blood platelets using a sample of...

  9. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated cell counter. 864.5200 Section 864.5200....5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or semi-automated device used to count red blood cells, white blood cells, or blood platelets using a sample of...

  10. 21 CFR 892.1130 - Nuclear whole body counter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nuclear whole body counter. 892.1130 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1130 Nuclear whole body counter. (a) Identification. A nuclear whole body counter is a device intended to measure the amount of radionuclides in...

  11. 21 CFR 892.1130 - Nuclear whole body counter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nuclear whole body counter. 892.1130 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1130 Nuclear whole body counter. (a) Identification. A nuclear whole body counter is a device intended to measure the amount of radionuclides in...

  12. 21 CFR 892.1130 - Nuclear whole body counter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nuclear whole body counter. 892.1130 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1130 Nuclear whole body counter. (a) Identification. A nuclear whole body counter is a device intended to measure the amount of radionuclides in...

  13. 21 CFR 892.1130 - Nuclear whole body counter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nuclear whole body counter. 892.1130 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1130 Nuclear whole body counter. (a) Identification. A nuclear whole body counter is a device intended to measure the amount of radionuclides in...

  14. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated cell counter. 864.5200 Section 864.5200....5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or semi-automated device used to count red blood cells, white blood cells, or blood platelets using a sample of...

  15. 21 CFR 864.5200 - Automated cell counter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated cell counter. 864.5200 Section 864.5200....5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or semi-automated device used to count red blood cells, white blood cells, or blood platelets using a sample of...

  16. Exciton-polariton condensation in transition metal dichalcogenide bilayer heterostructure

    NASA Astrophysics Data System (ADS)

    Lee, Ki Hoon; Jeong, Jae-Seung; Min, Hongki; Chung, Suk Bum

    For the bilayer heterostructure system in an optical microcavity, the interplay of the Coulomb interaction and the electron-photon coupling can lead to the emergence of quasiparticles consisting of the spatially indirect exciton and cavity photons known as dipolariton, which can form the Bose-Einstein condensate above a threshold density. Additional physics comes into play when each layer of the bilayer system consists of the transition metal dichalcogenide (TMD) monolayer. The TMD monolayer band structure in the low energy spectrum has two valley components with nontrivial Berry phase, which gives rise to a selection rule in the exciton-polariton coupling, e.g. the exciton from one (the other) valley can couple only to the clockwise (counter-clockwise) polarized photon. We investigate possible condensate phases of exciton-polariton in the bilayer TMD microcavity changing relevant parameters such as detuning, excitation density and interlayer distance. This work was supported in part by the Institute for Basic Science of Korea (IBS) under Grant IBS-R009-Y1 and by the National Research Foundation of Korea (NRF) under the Basic Science Research Program Grant No. 2015R1D1A1A01058071.

  17. Modeling reaction fronts of separated condensed phase reactants

    NASA Astrophysics Data System (ADS)

    Koundinyan, Sushilkumar; Matalon, Moshe; Stewart, D. Scott; Bdzil, John

    2015-06-01

    We present a Gibbs free energy approach to modeling reaction fronts in condensed phase reactive materials. The current interest is in chemical reactions of condensed phase reactants that are initially separated. In energetic materials such reactions are observed to occur extremely fast and at relatively sharp fronts. The solid-to-solid combustion process differs in several aspects from classical gaseous combustion due to the disparity between the characteristic thermal conductivity length and the mass diffusion lengths and a volume, temperature, stress, mass fraction equation of state that principally depends only on the component reference volumes and the current mixture composition. To retain a simple planar configuration, we consider the two reactants, in solid phase, are in motion towards each other characterized by counter-flow geometry. We apply the model to a simplified Titanium-Boron system and present the analysis of reaction zone length for various strain rates. The numerical results are validated with asymptotic approximations at the Burke-Schumann limit. Supported by HDTRA1-10-1-0020 (DTRA), AF Sub MO C00039417-1 (AFOSR/TRE).

  18. NEUTRONIC REACTOR COUNTER METHOD AND SYSTEM

    DOEpatents

    Graham, C.B.; Spiewak, I.

    1960-05-31

    An improved method is given for controlling the rate of fission in circulating-fuel neutronic reactors in which the fuel is a homogeneous liquid containing fissionable material and a neutron moderator. A change in the rate of flssion is effected by preferentially retaining apart from the circulating fuel a variable amount of either fissionable material or moderator, thereby varying the concentration of fissionable material in the fuel. In the case of an aqueous fuel solution a portion of the water may be continuously vaporized from the circulating solution and the amount of condensate, or condensate plus make-up water, returned to the solution is varied to control the fission rate.

  19. Film condensation in a horizontal rectangular duct

    NASA Technical Reports Server (NTRS)

    Lu, Qing; Suryanarayana, N. V.

    1992-01-01

    Condensation heat transfer in an annular flow regime with and without interfacial waves was experimentally investigated. The study included measurements of heat transfer rate with condensation of vapor flowing inside a horizontal rectangular duct and experiments on the initiation of interfacial waves in condensation, and adiabatic air-liquid flow. An analytical model for the condensation was developed to predict condensate film thickness and heat transfer coefficients. Some conclusions drawn from the study are that the condensate film thickness was very thin (less than 0.6 mm). The average heat transfer coefficient increased with increasing the inlet vapor velocity. The local heat transfer coefficient decreased with the axial distance of the condensing surface, with the largest change at the leading edge of the test section. The interfacial shear stress, which consisted of the momentum shear stress and the adiabatic shear stress, appeared to have a significant effect on the heat transfer coefficients. In the experiment, the condensate flow along the condensing surface experienced a smooth flow, a two-dimensional wavy flow, and a three-dimensional wavy flow. In the condensation experiment, the local wave length decreased with the axial distance of the condensing surface and the average wave length decreased with increasing inlet vapor velocity, while the wave speed increased with increasing vapor velocity. The heat transfer measurements are reliable. And, the ultrasonic technique was effective for measuring the condensate film thickness when the surface was smooth or had waves of small amplitude.

  20. Proceedings: 2000 Workshop on Condensate Polishing

    SciTech Connect

    2001-06-01

    Condensate polishing maintains control of impurities in the nuclear power plant and allows the unit to operate more reliably. This report presents proceedings of EPRI's 2000 Workshop on Condensate Polishing, where 30 papers were presented on current issues and utility experience involving condensate polishing at both pressurized water reactor (PWR) and boiling water reactor (BWR) plants.

  1. Exciton-polaritons condensate in a microwire

    NASA Astrophysics Data System (ADS)

    Kamoun, O.; Jaziri, S.

    2013-12-01

    Recently, polariton condensation has been claimed in microwires. Numerical solutions of the time-dependent Gross-Pitaevskii equation that describes the behavior of the condensate in a trap and exciton-polariton interaction, have been obtained. In this work we study theoretically exciton-polariton one dimensional condensation in several quantized states.

  2. Condensed matter analogues of cosmology

    NASA Astrophysics Data System (ADS)

    Kibble, Tom; Srivastava, Ajit

    2013-10-01

    It is always exciting when developments in one branch of physics turn out to have relevance in a quite different branch. It would be hard to find two branches farther apart in terms of energy scales than early-universe cosmology and low-temperature condensed matter physics. Nevertheless ideas about the formation of topological defects during rapid phase transitions that originated in the context of the very early universe have proved remarkably fruitful when applied to a variety of condensed matter systems. The mathematical frameworks for describing these systems can be very similar. This interconnection has led to a deeper understanding of the phenomena in condensed matter systems utilizing ideas from cosmology. At the same time, one can view these condensed matter analogues as providing, at least in a limited sense, experimental access to the phenomena of the early universe for which no direct probe is possible. As this special issue well illustrates, this remains a dynamic and exciting field. The basic idea is that when a system goes through a rapid symmetry-breaking phase transition from a symmetric phase into one with spontaneously broken symmetry, the order parameter may make different choices in different regions, creating domains that when they meet can trap defects. The scale of those domains, and hence the density of defects, is constrained by the rate at which the system goes through the transition and the speed with which order parameter information propagates. This is what has come to be known as the Kibble-Zurek mechanism. The resultant scaling laws have now been tested in a considerable variety of different systems. The earliest experiments illustrating the analogy between cosmology and condensed matter were in liquid crystals, in particular on the isotropic-to-nematic transition, primarily because it is very easy to induce the phase transition (typically at room temperature) and to image precisely what is going on. This field remains one of the

  3. The Timing Counter of the MEG Experiment

    NASA Astrophysics Data System (ADS)

    Fratini, K.

    2010-04-01

    The MEG experiment is searching for the rare μ+ → e+γ decay with a sensitivity on the BR at the level of 10-13. This kind of precision needs stringent requirements on the performances of the detectors involved in the project. In particular, the Timing Counter detector has been designed to measure the time and the position of the positron at the end of its path inside the MEG detector, reaching a resolution of 100 ps FWHM and 1 cm, respectively. The Timing Counter consists of two subdetectors: one made of contiguous scintillator bars having PMTs at their opposite ends, and the other one made of scintillating fibers read by APDs. Both sub-detectors also generate a first level trigger signal for timing and direction of the positron, respectively.

  4. Boron-10 Lined Proportional Counter Model Validation

    SciTech Connect

    Lintereur, Azaree T.; Siciliano, Edward R.; Kouzes, Richard T.

    2012-06-30

    The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project “Coincidence Counting With Boron-Based Alternative Neutron Detection Technology” at Pacific Northwest National Laboratory (PNNL) for the development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube-based alternative system in the configuration of a coincidence counter. This report discusses the validation studies performed to establish the degree of accuracy of the computer modeling methods current used to simulate the response of boron-lined tubes. This is the precursor to developing models for the uranium neutron coincidence collar under Task 2 of this project.

  5. Coaxial anode wire for gas radiation counters

    NASA Technical Reports Server (NTRS)

    Kraushaar, W. L. (Inventor)

    1974-01-01

    The design and characteristics of a gas radiation counter are discussed. The coaxial anode consists of an elongated central wire covered with an electrically insulating sleeve. Several longitudinally discontinuous segments of an electrically conductive coating are disposed about the insulating sleeve in a coaxial pattern along the length of the central wire. The conductive coating segments form a veto or rejection anode at each end of the central wire and a main or primary charge detecting anode between the ends. The segments are coupled together so that the primary charge detecting anode is connected to detection circuitry in anti-coincidence with the veto anodes. Background radiation detected by either of the veto anodes and the primary charge detecting anode is rejected and the sensitivity of the radiation counter device is increased.

  6. Projections from the central amygdaloid nucleus to the precuneiform nucleus in the mouse.

    PubMed

    Liang, Huazheng; Watson, Charles; Paxinos, George

    2015-01-01

    The mouse precuneiform nucleus has been proposed as the midbrain locomotion center, a function ascribed to its caudal neighbor, cuneiform nucleus, in the rat, cat and other species. The present study investigated the projections from the central amygdaloid nucleus to the precuneiform nucleus in the mouse using retrograde tracer injections (fluoro-gold) into the precuneiform nucleus and anterograde tracer injections (biotinylated dextran amine) into the central amygdaloid nucleus. The entire central amygdaloid nucleus except the rostral pole had retrogradely labeled neurons, especially in the middle portion where labeled neurons were densely packed. Anterogradely labeled amygdaloid fibers approached the precuneiform nucleus from the area ventrolateral to it and terminated in the entire precuneiform nucleus. Labeled fibers were also found in laminae 5 and 6 in the upper cervical cord on the ipsilateral side. The present study is the first demonstration of projections from the central amygdaloid nucleus to the precuneiform nucleus. This projection may underpin the role of the precuneiform nucleus in the modulation of the cardiovascular activity.

  7. Solar nebula condensates and the composition of comets

    NASA Technical Reports Server (NTRS)

    Lunine, J. I.

    1989-01-01

    Interpretation of the volatile abundances in Halley's comet in terms of models for chemical and physical processes in the solar nebula are discussed. Key ratios of the oxidized and reduced species of nitrogen and carbon are identified which tell something of the chemical history of the environment in which cometary grains accreted to form the nucleus. Isotopic abundances are also applied to this problem. It will be shown that the abundances of methane and carbon monoxide are consistent both with models of solar nebula chemistry and chemical processing on grains in star-forming regions. Ultimately, limitations of the current data set on molecular abundances in comets and star-forming regions prevent a definitive choice between the two. Processes important to the composition of outer solar system bodies are: (1) gas phase chemistry in the solar nebula; (2) imperfect mixing in the solar nebula; (3) condensation; (4) clathration; (5) adsorption; and (6) processing of interstellar material.

  8. Gamma heating measurements with proportional counters

    SciTech Connect

    Chiu, H.; Bennett, E.F.; Micklich, B.J.

    1990-05-01

    A new data acquisition technique (the Continuously-varied Bias- voltage Acquisition mode) has been developed and tested for the low-flux broad-energy regime characteristic of existing fusion blanket mock-ups. This method of analysis allows for the acquisition of data spanning several orders of magnitude in energy with a single proportional counter. Utilizing this method, the gamma energy deposition in a mixed neutron and gamma field was measured. 7 refs., 5 figs.

  9. Neutron counter based on beryllium activation

    SciTech Connect

    Bienkowska, B.; Prokopowicz, R.; Kaczmarczyk, J.; Paducha, M.; Scholz, M.; Igielski, A.; Karpinski, L.; Pytel, K.

    2014-08-21

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction {sup 9}Be(n, α){sup 6}He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, {sup 6}He, decays with half-life T{sub 1/2} = 0.807 s emitting β{sup −} particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of β–particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known β–source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5–the Monte Carlo transport code. It allowed proper application of the results of transport calculations of β{sup −} particles emitted from radioactive {sup 6}He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  10. Universal Fast Breeder Reactor Subassembly Counter manual

    SciTech Connect

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications.

  11. Polymer Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Castellanos, E.; Chacón-Acosta, G.

    2013-05-01

    In this work we analyze a non-interacting one-dimensional polymer Bose-Einstein condensate in a harmonic trap within the semiclassical approximation. We use an effective Hamiltonian coming from the polymer quantization that arises in loop quantum gravity. We calculate the number of particles in order to obtain the critical temperature. The Bose-Einstein functions are replaced by series, whose high order terms are related to powers of the polymer length. It is shown that the condensation temperature presents a shift respect to the standard case, for small values of the polymer scale. In typical experimental conditions, it is possible to establish a bound for λ2 up to ≲10-16 m2. To improve this bound we should decrease the frequency of the trap and also decrease the number of particles.

  12. Brake for counter rotating bladed members

    SciTech Connect

    Cedoz, R.W.

    1987-02-10

    This patent describes a propulsion system including a gas turbine engine having an output shaft and a gear drive having a planetary gear set with a first element connected to the engine output shaft and a second element connected to a first bladed member and a third element connected to a second bladed member whereby the first and second bladed members are rotated in opposite directions by the output shaft. A brake is described comprising, a first transfer shaft supported on a stationary housing for rotation about an axis of the latter, a second transfer shaft supported on the stationary housing for rotation about the axis, gear means between one of the counter rotating bladed members and the first transfer shaft and gear means between the other of the counter rotating bladed members and the second transfer shaft. The brake also includes a selectively operable brake actuator on the housing movable between an extended position and a retracted position, and friction means between the brake actuator and each of first and second transfer shafts operative in the extended position of the brake actuator to simultaneously frictionally retard rotation of each of the first and the second transfer shafts whereby each of the counter rotating bladed members is simultaneously braked.

  13. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Pooser, Eric; GlueX Collaboration

    2015-03-01

    The GlueX experiment will study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information which is used in the level-1 trigger of the experiment. This detector is designed to operate at photon intensities of up to 108 γ / s in the coherent peak and provide a timing resolution < 350 ps so as to provide successful identification of the electron beam buckets to within 99 % accuracy. Furthermore, the Start Counter detector will provide excellent solid angle coverage, ~ 90 % of 4 π hermeticity , and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Silicon PhotoMultiplier (SiPM) detectors have been selected as the readout system. The physical properties of the Start Counter have been studied extensively. The results of theses studies are discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177 & DE-FG02-99ER41065.

  14. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Pooser, Eric; GlueX Collaboration

    2015-04-01

    The GlueX experiment will study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information which is used in the level-1 trigger of the experiment. This detector is designed to operate at photon intensities of up to 108 γ / s in the coherent peak and provide a timing resolution < 350ps so as to provide successful identification of the electron beam buckets to within 99 % accuracy. Furthermore, the Start Counter detector will provide excellent solid angle coverage, ~ 90 % of 4 π hermeticity , and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Silicon PhotoMultiplier (SiPM) detectors have been selected as the readout system. The physical properties of the Start Counter have been studied extensively. The results of theses studies are discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contracts DE-AC05-06OR23177 & DE-FG02-99ER41065.

  15. Extreme-UV lithography condenser

    DOEpatents

    Sweatt, William C.; Sweeney, Donald W.; Shafer, David; McGuire, James

    2001-01-01

    Condenser system for use with a ringfield camera in projection lithography where the condenser includes a series of segments of a parent aspheric mirror having one foci at a quasi-point source of radiation and the other foci at the radius of a ringfield have all but one or all of their beams translated and rotated by sets of mirrors such that all of the beams pass through the real entrance pupil of a ringfield camera about one of the beams and fall onto the ringfield radius as a coincident image as an arc of the ringfield. The condenser has a set of correcting mirrors with one of the correcting mirrors of each set, or a mirror that is common to said sets of mirrors, from which the radiation emanates, is a concave mirror that is positioned to shape a beam segment having a chord angle of about 25 to 85 degrees into a second beam segment having a chord angle of about 0 to 60 degrees.

  16. Condensation on Slippery Asymmetric Bumps

    NASA Astrophysics Data System (ADS)

    Park, Kyoo-Chul; Kim, Philseok; Aizenberg, Joanna

    Controlling dropwise condensation by designing surfaces that enable droplets to grow rapidly and be shed as quickly as possible is fundamental to water harvesting systems, thermal power generation, distillation towers, etc. However, cutting-edge approaches based on micro/nanoscale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach based on principles derived from Namib desert beetles, cacti, and pitcher plants that synergistically couples both aspects of condensation and outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle's bump geometry in promoting condensation, we show how to maximize vapor diffusion flux at the apex of convex millimetric bumps by optimizing curvature and shape. Integrating this apex geometry with a widening slope analogous to cactus spines couples rapid drop growth with fast directional transport, by creating a free energy profile that drives the drop down the slope. This coupling is further enhanced by a slippery, pitcher plant-inspired coating that facilitates feedback between coalescence-driven growth and capillary-driven motion. We further observe an unprecedented six-fold higher exponent in growth rate and much faster shedding time compared to other surfaces. We envision that our fundamental understanding and rational design strategy can be applied to a wide range of phase change applications.

  17. Condensation on Slippery Asymmetric Bumps

    NASA Astrophysics Data System (ADS)

    Park, Kyoo-Chul; Kim, Philseok; Aizenberg, Joanna

    2016-11-01

    Controlling dropwise condensation by designing surfaces that enable droplets to grow rapidly and be shed as quickly as possible is fundamental to water harvesting systems, thermal power generation, distillation towers, etc. However, cutting-edge approaches based on micro/nanoscale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach based on principles derived from Namib desert beetles, cacti, and pitcher plants that synergistically couples both aspects of condensation and outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle's bump geometry in promoting condensation, we show how to maximize vapor diffusion flux at the apex of convex millimetric bumps by optimizing curvature and shape. Integrating this apex geometry with a widening slope analogous to cactus spines couples rapid drop growth with fast directional transport, by creating a free energy profile that drives the drop down the slope. This coupling is further enhanced by a slippery, pitcher plant-inspired coating that facilitates feedback between coalescence-driven growth and capillary-driven motion. We further observe an unprecedented six-fold higher exponent in growth rate and much faster shedding time compared to other surfaces. We envision that our fundamental understanding and rational design strategy can be applied to a wide range of phase change applications.

  18. Hardware support for software controlled fast multiplexing of performance counters

    DOEpatents

    Salapura, Valentina; Wisniewski, Robert W.

    2013-01-01

    Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

  19. Hardware support for software controlled fast multiplexing of performance counters

    DOEpatents

    Salapura, Valentina; Wisniewski, Robert W

    2013-10-01

    Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

  20. Actomyosin contractility rotates the cell nucleus.

    PubMed

    Kumar, Abhishek; Maitra, Ananyo; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G V

    2014-01-21

    The cell nucleus functions amidst active cytoskeletal filaments, but its response to their contractile stresses is largely unexplored. We study the dynamics of the nuclei of single fibroblasts, with cell migration suppressed by plating onto micro-fabricated patterns. We find the nucleus undergoes noisy but coherent rotational motion. We account for this observation through a hydrodynamic approach, treating the nucleus as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and coherence of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be an intrinsic property of cells.

  1. Forward Physics in Proton-Nucleus and Nucleus-Nucleus Collisions

    SciTech Connect

    Nemchik, J.; Potashnikova, I. K.

    2008-10-13

    We present an universal treatment for a substantial nuclear suppression representing a common feature of all known reactions on nuclear targets (forward production of high-p{sub T} hadrons, production of direct photons, the Drell-Yan process, heavy flavor production, etc.). Such a suppression at large Feynman x{sub F}, corresponding to region of minimal light-cone momentum fraction variable x{sub 2} in nuclei, is tempting to interpret as a manifestation of coherence or the Color Glass Condensate. We demonstrate, however, that it is actually a simple consequence of energy conservation and takes place even at low energies, where no effects of coherence are possible. We analyze this common suppression mechanism for several processes performing model predictions in the light-cone dipole approach. Our calculations agree with the data.

  2. Condensation shocks in hypersonic nitrogen tunnels

    NASA Technical Reports Server (NTRS)

    Hudson, Susan T.; Griffith, Wayland C.; Lederer, Melissa; Ragsdale, William C.; Yanta, William J.

    1990-01-01

    Experimental observations and a theoretical model for the onset and disappearance of condensation are provided for hypersonic flows of pure nitrogen at M = 10, 14, and 18. A method for analyzing the thermodynamic and flow properties of a partially condensed mixture from known supply conditions and measured Pitot pressure yields the local static pressure and temperature, mass fraction of the nitrogen condensed, and the Mach number of the partially condensed flow based on frozen sound speed. The transition between partially condensed-supercooled flow is found to occur at 22-25 K isobaric supercooling with the corresponding mass fraction condensed being 12-14 percent over a range of two orders of magnitude in local static pressure. The heat released and vapor mass removed during condensation ultimately raise the local pressure and temperature and reduce the flow Mach number.

  3. Music and the nucleus accumbens.

    PubMed

    Mavridis, Ioannis N

    2015-03-01

    Music is a universal feature of human societies over time, mainly because it allows expression and regulation of strong emotions, thus influencing moods and evoking pleasure. The nucleus accumbens (NA), the most important pleasure center of the human brain (dominates the reward system), is the 'king of neurosciences' and dopamine (DA) can be rightfully considered as its 'crown' due to the fundamental role that this neurotransmitter plays in the brain's reward system. Purpose of this article was to review the existing literature regarding the relation between music and the NA. Studies have shown that reward value for music can be coded by activity levels in the NA, whose functional connectivity with auditory and frontal areas increases as a function of increasing musical reward. Listening to music strongly modulates activity in a network of mesolimbic structures involved in reward processing including the NA. The functional connectivity between brain regions mediating reward, autonomic and cognitive processing provides insight into understanding why listening to music is one of the most rewarding and pleasurable human experiences. Musical stimuli can significantly increase extracellular DA levels in the NA. NA DA and serotonin were found significantly higher in animals exposed to music. Finally, passive listening to unfamiliar although liked music showed activations in the NA.

  4. Condensing efficiency of the truncated cone condenser and its comparison with the Winston cone condenser in terahertz region

    NASA Astrophysics Data System (ADS)

    Aoki, Makoto; Hiromoto, Norihisa

    2015-01-01

    The angle-dependent condensing efficiency of a truncated cone condenser (TCC) in the terahertz (THz) region has been examined by 2D ray tracing and 3D electromagnetic simulation. The condensing efficiency in the THz region is transferred to that in the optical region by theoretical dispersive reflection from a rough surface, and it is confirmed that the latter is consistent with the measured condensing efficiency in the optical region. Although the TCC has a gradual field of view (FOV) compared with the Winston cone condenser (WCC), we improved the steepness of the FOV by adding a baffle before the input aperture of the TCC. We also proved that the TCC has a high condensing efficiency at around normal incidence in comparison with the WCC in the THz region.

  5. Detecting stripe phase in spin-orbit coupled condensates via optical Bragg scattering

    NASA Astrophysics Data System (ADS)

    Putra, Andika; Carcoba, Francisco Salces; Yue, Yuchen; Sugawa, Seiji; Spielman, Ian

    2016-05-01

    The stripe phase in spin-orbit coupled condensates has been predicted theoretically but not yet been observed. This peculiar feature, analogue to supersolidity, originates from the interaction effects and spin-momentum locking between different spin states. Motivated by recent observation of antiferromagnetic correlations in cold atoms, we explore the feasibility of Bragg diffraction to observe the stripe phase. Here, we create spin-orbit coupled condensates in f = 1 ground state manifold of Rb87 using a pair of cross-polarized 790.02 nm counter-propagating laser beams. Using similar setup, we make a spin-dependent one dimensional lattice and demonstrate Bragg scattering of light to calibrate the atomic density distribution. This enables us to do a direct measure of the stripe phase.

  6. Condensation on slippery asymmetric bumps.

    PubMed

    Park, Kyoo-Chul; Kim, Philseok; Grinthal, Alison; He, Neil; Fox, David; Weaver, James C; Aizenberg, Joanna

    2016-03-03

    Controlling dropwise condensation is fundamental to water-harvesting systems, desalination, thermal power generation, air conditioning, distillation towers, and numerous other applications. For any of these, it is essential to design surfaces that enable droplets to grow rapidly and to be shed as quickly as possible. However, approaches based on microscale, nanoscale or molecular-scale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach--based on principles derived from Namib desert beetles, cacti, and pitcher plants--that synergistically combines these aspects of condensation and substantially outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle's bumpy surface geometry in promoting condensation, and using theoretical modelling, we show how to maximize vapour diffusion fluxat the apex of convex millimetric bumps by optimizing the radius of curvature and cross-sectional shape. Integrating this apex geometry with a widening slope, analogous to cactus spines, directly couples facilitated droplet growth with fast directional transport, by creating a free-energy profile that drives the droplet down the slope before its growth rate can decrease. This coupling is further enhanced by a slippery, pitcher-plant-inspired nanocoating that facilitates feedback between coalescence-driven growth and capillary-driven motion on the way down. Bumps that are rationally designed to integrate these mechanisms are able to grow and transport large droplets even against gravity and overcome the effect of an unfavourable temperature gradient. We further observe an unprecedented sixfold-higher exponent of growth rate, faster onset, higher steady-state turnover rate, and a greater volume of water collected compared to other surfaces. We envision that this fundamental understanding and rational design strategy can be

  7. Condensation on slippery asymmetric bumps

    NASA Astrophysics Data System (ADS)

    Park, Kyoo-Chul; Kim, Philseok; Grinthal, Alison; He, Neil; Fox, David; Weaver, James C.; Aizenberg, Joanna

    2016-03-01

    Controlling dropwise condensation is fundamental to water-harvesting systems, desalination, thermal power generation, air conditioning, distillation towers, and numerous other applications. For any of these, it is essential to design surfaces that enable droplets to grow rapidly and to be shed as quickly as possible. However, approaches based on microscale, nanoscale or molecular-scale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach—based on principles derived from Namib desert beetles, cacti, and pitcher plants—that synergistically combines these aspects of condensation and substantially outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle’s bumpy surface geometry in promoting condensation, and using theoretical modelling, we show how to maximize vapour diffusion fluxat the apex of convex millimetric bumps by optimizing the radius of curvature and cross-sectional shape. Integrating this apex geometry with a widening slope, analogous to cactus spines, directly couples facilitated droplet growth with fast directional transport, by creating a free-energy profile that drives the droplet down the slope before its growth rate can decrease. This coupling is further enhanced by a slippery, pitcher-plant-inspired nanocoating that facilitates feedback between coalescence-driven growth and capillary-driven motion on the way down. Bumps that are rationally designed to integrate these mechanisms are able to grow and transport large droplets even against gravity and overcome the effect of an unfavourable temperature gradient. We further observe an unprecedented sixfold-higher exponent of growth rate, faster onset, higher steady-state turnover rate, and a greater volume of water collected compared to other surfaces. We envision that this fundamental understanding and rational design strategy can be

  8. J/ψ production and suppression in high-energy proton-nucleus collisions

    SciTech Connect

    Ma, Yan -Qing; Venugopalan, Raju; Zhang, Hong -Fei

    2015-10-02

    In this study, we apply a color glass condensate+nonrelativistic QCD (CGC+NRQCD) framework to compute J/ψ production in deuteron-nucleus collisions at RHIC and proton-nucleus collisions at the LHC. Our results match smoothly at high p⊥ to a next-to-leading order perturbative QCD+NRQCD computation. Excellent agreement is obtained for p⊥ spectra at the RHIC and LHC for central and forward rapidities, as well as for the normalized ratio RpA of these results to spectra in proton-proton collisions. In particular, we observe that the RpA data are strongly bounded by our computations of the same for each of the individual NRQCD channels; this result provides strong evidence that our description is robust against uncertainties in initial conditions and hadronization mechanisms.

  9. J/ψ production and suppression in high-energy proton-nucleus collisions

    DOE PAGES

    Ma, Yan -Qing; Venugopalan, Raju; Zhang, Hong -Fei

    2015-10-02

    In this study, we apply a color glass condensate+nonrelativistic QCD (CGC+NRQCD) framework to compute J/ψ production in deuteron-nucleus collisions at RHIC and proton-nucleus collisions at the LHC. Our results match smoothly at high p⊥ to a next-to-leading order perturbative QCD+NRQCD computation. Excellent agreement is obtained for p⊥ spectra at the RHIC and LHC for central and forward rapidities, as well as for the normalized ratio RpA of these results to spectra in proton-proton collisions. In particular, we observe that the RpA data are strongly bounded by our computations of the same for each of the individual NRQCD channels; this resultmore » provides strong evidence that our description is robust against uncertainties in initial conditions and hadronization mechanisms.« less

  10. Marine Steam Condenser Design Optimization.

    DTIC Science & Technology

    1983-12-01

    Rerf . 61. !kS 2XLI: Those parametars which the opti heztion proqran ms--faitted to change in order to improre’the esign. Pesin variablis appear oely on...subroutine SEC& LC is called. 5. jZ.~ This subroutine determines all the parameters of each of the sectors in the condenser by row. The first...force the pressure losses to converge to a single value. Once steam flow to the sectors has been adjusted, the sector and row analysis in SEC& LC is

  11. Direct condensation by humid air

    NASA Astrophysics Data System (ADS)

    Schwab, S.; Schiebelsberger, B.

    1980-12-01

    The practicability of direct condensation with humid air (DKFL) for waste heat removal from thermal power plants was investigated with regard to technical, economical and environmental aspects. The adjustment of a uniform trickling-water film was examined. A vertical test tube was erected to study the phenomenon of a trickling-water film. A pilot plant with a vertical tube-bundle was installed to evaluate the main process parameters. The applicability of the cooling system is judged. A theoretical model was derived for the design of a DKFL apparatus. A vertical geometry for the test tube has essential operational and economical advantages in comparison with a horizontal one.

  12. Turbulent Distortion of Condensate Accretion

    NASA Technical Reports Server (NTRS)

    Hazoume, R.; Orou Chabi, J.; Johnson, J. A., III

    1997-01-01

    When a simple model for the relationship between the density-temperature fluctuation correlation and mean values is used, we determine that the rate of change of turbulent intensity can influence directly the accretion rate of droplets. Considerable interest exists in the accretion rate for condensates in nonequilibrium flow with icing and the potential role which reactant accretion can play in nonequilibrium exothermic reactant processes. Turbulence is thought to play an important role in such flows. It has already been experimentally determined that turbulence influences the sizes of droplets in the heterogeneous nucleation of supersaturated vapors. This paper addresses the issue of the possible influence of turbulence on the accretion rate of droplets.

  13. Self-regulating neutron coincidence counter

    DOEpatents

    Baron, N.

    1980-06-16

    A device for accurately measuring the mass of /sup 240/Pu and /sup 239/Pu in a sample having arbitrary moderation and mixed with various contaminants. The device utilizes a thermal neutron well counter which has two concentric rings of neutron detectors separated by a moderating material surrounding the well. Neutron spectroscopic information derived by the two rings of detectors is used to measure the quantity of /sup 239/Pu and /sup 240/Pu in device which corrects for background radiation, deadtime losses of the detector and electronics and various other constants of the system.

  14. Test of lead glass shower counters

    SciTech Connect

    Kawabata, S.; Ogawa, K.; Sugahara, R.; Sumiyoshi, T.; Takahashi, K.; Awaji, N.; Hayashii, H.; Iwata, S.; Gearhart, R.A.; Miyamoto, A.

    1983-10-01

    Lead glass counters made of wedge shaped blocks of SF6 were tested with positrons at SLAC. The beam energy ranged from 2 to 17.5 GeV. Energy dependence and beam position dependence of pulse height and energy resolution were studied with lead glass blocks of various lengths. The effect of a BK-7 light guide on pulse height was clearly observed. Degradation of the energy resolution due to aluminum absorbers of various lengths was investigated. A mesh type photomultiplier was also tested.

  15. Shared address collectives using counter mechanisms

    DOEpatents

    Blocksome, Michael; Dozsa, Gabor; Gooding, Thomas M; Heidelberger, Philip; Kumar, Sameer; Mamidala, Amith R; Miller, Douglas

    2014-02-18

    A shared address space on a compute node stores data received from a network and data to transmit to the network. The shared address space includes an application buffer that can be directly operated upon by a plurality of processes, for instance, running on different cores on the compute node. A shared counter is used for one or more of signaling arrival of the data across the plurality of processes running on the compute node, signaling completion of an operation performed by one or more of the plurality of processes, obtaining reservation slots by one or more of the plurality of processes, or combinations thereof.

  16. Structural tailoring of counter rotation propfans

    NASA Technical Reports Server (NTRS)

    Brown, Kenneth W.; Hopkins, D. A.

    1989-01-01

    The STAT program was designed for the optimization of single rotation, tractor propfan designs. New propfan designs, however, generally consist of two counter rotating propfan rotors. STAT is constructed to contain two levels of analysis. An interior loop, consisting of accurate, efficient approximate analyses, is used to perform the primary propfan optimization. Once an optimum design has been obtained, a series of refined analyses are conducted. These analyses, while too computer time expensive for the optimization loop, are of sufficient accuracy to validate the optimized design. Should the design prove to be unacceptable, provisions are made for recalibration of the approximate analyses, for subsequent reoptimization.

  17. Counter-Revolutionary Warfare: Strategy Considerations

    DTIC Science & Technology

    1986-05-01

    countering revolutionary war after it has broken out and suggests some ways to best aid our allies in revolutionary warfighting. 2 1,’ _ I’A.4J J- v g r...terms. This is the best way to avoid entanglement in alliances like the one we had in Iran where we were allied with the Shah and ignored his...of the support we provide changes character. The ratio of military to other forms of aid rises, perhaps dramatically. How can we best help an ally

  18. Taxing Junk Food to Counter Obesity

    PubMed Central

    Franck, Caroline; Grandi, Sonia M.

    2013-01-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity. PMID:24028245

  19. Taxing junk food to counter obesity.

    PubMed

    Franck, Caroline; Grandi, Sonia M; Eisenberg, Mark J

    2013-11-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity.

  20. Ice Nucleus Characteristics of Mount St. Helens Effluents

    SciTech Connect

    Schnell, R.C.; Pueschel, R.F.; Wellman, D.L.

    1982-12-20

    Aerosols were studied in situ and captured on membrane filters from an aircraft flown around Mount St. Helens during its phreatic period in April 1980. Bulk samples of volcanic ash were collected at ground level 120 km downwind on May 19, 1980 and reaerosolized in a laboratory in ash cloud simulation studies. The aerosol and/or ash samples were tested for ice nucleus (IN) activity using four different IN measurement systems (NCAR acoustical counter, bulk drop freezing, NCAR dynamic thermal diffusion chamber, and filter drop freezing). Although threshold IN activity was observed at -8/sup 0/C in bulk ash, in aerosols there were few IN active at temperatures warmer than -12/sup 0/C. At -12/sup 0/C, IN concentrations were less than 0.4 l/sup -1/ (400 m/sup -3/) even when the aerosol concentrations were as high as 3000 ..mu..g m/sup -3/. At aerosol concentrations of 500 ..mu..g m/sup -3/ and less, the IN content of the ash was below background threshold temperatures of -18/sup 0/C.

  1. Label-free three-dimensional imaging of cell nucleus using third-harmonic generation microscopy

    SciTech Connect

    Lin, Jian; Zheng, Wei; Wang, Zi; Huang, Zhiwei

    2014-09-08

    We report the implementation of the combined third-harmonic generation (THG) and two-photon excited fluorescence (TPEF) microscopy for label-free three-dimensional (3-D) imaging of cell nucleus morphological changes in liver tissue. THG imaging shows regular spherical shapes of normal hepatocytes nuclei with inner chromatin structures while revealing the condensation of chromatins and nuclear fragmentations in hepatocytes of diseased liver tissue. Colocalized THG and TPEF imaging provides complementary information of cell nuclei and cytoplasm in tissue. This work suggests that 3-D THG microscopy has the potential for quantitative analysis of nuclear morphology in cells at a submicron-resolution without the need for DNA staining.

  2. Investigation of condensed matter fusion

    SciTech Connect

    Jones, S.E.; Berrondo, M.; Czirr, J.B.; Decker, D.L.; Harrison, K.; Jensen, G.L.; Palmer, E.P.; Rees, L.B.; Taylor, S.; Vanfleet, H.B.; Wang, J.C.; Bennion, D.N.; Harb, J.N.; Pitt, W.G.; Thorne, J.M.; Anderson, A.N.; McMurtry, G.; Murphy, N.; Goff, F.E.

    1990-12-01

    Work on muon-catalyzed fusion led to research on a possible new type of fusion occurring in hydrogen isotopes embedded in metal lattices. While the nuclear-product yields observed to date are so small as to require careful further checking, rates observed over short times appear sufficiently large to suggest that significant neutrons and triton yields could be realized -- if the process could be understood and controlled. During 1990, we have developed two charged-particle detection systems and three new neutron detectors. A segmented, high-efficiency neutron counter was taken into 600 m underground in a mine in Colorado for studies out of the cosmic-ray background. Significant neutron emissions were observed in this environment in both deuterium-gas-loaded metals and in electrolytic cells, confirming our earlier observations.

  3. Spatially Resolved Quantification of Chromatin Condensation through Differential Local Rheology in Cell Nuclei Fluorescence Lifetime Imaging.

    PubMed

    Spagnol, Stephen T; Dahl, Kris Noel

    2016-01-01

    The linear sequence of DNA encodes access to the complete set of proteins that carry out cellular functions. Yet, much of the functionality appropriate for each cell is nested within layers of dynamic regulation and organization, including a hierarchy of chromatin structural states and spatial arrangement within the nucleus. There remain limitations in our understanding of gene expression within the context of nuclear organization from an inability to characterize hierarchical chromatin organization in situ. Here we demonstrate the use of fluorescence lifetime imaging microscopy (FLIM) to quantify and spatially resolve chromatin condensation state using cell-permeable, DNA-binding dyes (Hoechst 33342 and PicoGreen). Through in vitro and in situ experiments we demonstrate the sensitivity of fluorescence lifetime to condensation state through the mechanical effects that accompany the structural changes and are reflected through altered viscosity. The establishment of FLIM for resolving and quantifying chromatin condensation state opens the door for single-measurement mechanical studies of the nucleus and for characterizing the role of genome structure and organization in nuclear processes that accompany physiological and pathological changes.

  4. Bio-oil fractionation and condensation

    DOEpatents

    Brown, Robert C; Jones, Samuel T; Pollard, Anthony

    2013-07-02

    A method of fractionating bio-oil vapors which involves providing bio-oil vapors comprising bio-oil constituents is described. The bio-oil vapors are cooled in a first stage which comprises a condenser having passages for the bio-oil separated by a heat conducting wall from passages for a coolant. The coolant in the condenser of the first stage is maintained at a substantially constant temperature, set at a temperature in the range of 75 to 100.degree. C., to condense a first liquid fraction of liquefied bio-oil constituents in the condenser of the first stage. The first liquid fraction of liquified bio-oil constituents from the condenser in the first stage is collected. Also described are steps for subsequently recovering further liquid fractions of liquefied bio-oil constituents. Particular compositions of bio-oil condensation products are also described.

  5. DNA condensation in one dimension

    NASA Astrophysics Data System (ADS)

    Pardatscher, Günther; Bracha, Dan; Daube, Shirley S.; Vonshak, Ohad; Simmel, Friedrich C.; Bar-Ziv, Roy H.

    2016-12-01

    DNA can be programmed to assemble into a variety of shapes and patterns on the nanoscale and can act as a template for hybrid nanostructures such as conducting wires, protein arrays and field-effect transistors. Current DNA nanostructures are typically in the sub-micrometre range, limited by the sequence space and length of the assembled strands. Here we show that on a patterned biochip, DNA chains collapse into one-dimensional (1D) fibres that are 20 nm wide and around 70 µm long, each comprising approximately 35 co-aligned chains at its cross-section. Electron beam writing on a photocleavable monolayer was used to immobilize and pattern the DNA molecules, which condense into 1D bundles in the presence of spermidine. DNA condensation can propagate and split at junctions, cross gaps and create domain walls between counterpropagating fronts. This system is inherently adept at solving probabilistic problems and was used to find the possible paths through a maze and to evaluate stochastic switching circuits. This technique could be used to propagate biological or ionic signals in combination with sequence-specific DNA nanotechnology or for gene expression in cell-free DNA compartments.

  6. CPU Performance Counter-Based Problem Diagnosis for Software Systems

    DTIC Science & Technology

    2009-09-01

    that affects the entire system. Studies [31, 36] demonstrate that a wide variety of these sorts of failures occur in e-commerce applications. Failures...CPU Performance Counters Nearly any software that makes use of CPU performance counters uses some sort library and/or kernel API to access and control...processor’s counters. Most approaches that use a processor’s performance monitoring features do some sort of sta- tistical profiling. Anderson et al

  7. Using DMA for copying performance counter data to memory

    DOEpatents

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

    2012-09-25

    A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance counter data.

  8. Ultra-low threshold polariton condensation

    NASA Astrophysics Data System (ADS)

    Steger, Mark; Fluegel, Brian; Alberi, Kirstin; Snoke, David W.; Pfeiffer, Loren N.; West, Ken; Mascarenhas, Angelo

    2017-03-01

    We demonstrate condensation of microcavity polaritons with a very sharp threshold occuring at two orders of magnitude lower pump intensity than previous demonstrations of condensation. The long cavity-lifetime and trapping and pumping geometries are crucial to the realization of this low threshold. Polariton condensation, or "polariton lasing" has long been proposed as a promising source of coherent light at lower threshold than traditional lasing, and these results suggest methods to bring this threshold even lower.

  9. High-temperature condensates in carbonaceous chondrites

    NASA Technical Reports Server (NTRS)

    Grossman, L.

    1977-01-01

    Equilibrium thermodynamic calculations of the sequence of condensation of minerals from a cooling gas of solar composition play an important role in explaining the mineralogy and trace element content of different types of inclusions in carbonaceous chondrites. Group IV B iron meteorites and enstatite chondrites may also be direct condensates from the solar nebula. Condensation theory provides a framework within which chemical fractionations between different classes of chondrites may be understood.

  10. Ultra-low threshold polariton condensation.

    PubMed

    Steger, Mark; Fluegel, Brian; Alberi, Kirstin; Snoke, David W; Pfeiffer, Loren N; West, Ken; Mascarenhas, Angelo

    2017-03-15

    We demonstrate the condensation of microcavity polaritons with a very sharp threshold occurring at a two orders of magnitude pump intensity lower than previous demonstrations of condensation. The long cavity lifetime and trapping and pumping geometries are crucial to the realization of this low threshold. Polariton condensation, or "polariton lasing" has long been proposed as a promising source of coherent light at a lower threshold than traditional lasing, and these results indicate some considerations for optimizing designs for lower thresholds.

  11. Dynamic risk control by human nucleus accumbens.

    PubMed

    Nachev, Parashkev; Lopez-Sosa, Fernando; Gonzalez-Rosa, Javier Jesus; Galarza, Ana; Avecillas, Josue; Pineda-Pardo, Jose Angel; Lopez-Ibor, Juan José; Reneses, Blanca; Barcia, Juan Antonio; Strange, Bryan

    2015-12-01

    Real-world decisions about reward often involve a complex counterbalance of risk and value. Although the nucleus accumbens has been implicated in the underlying neural substrate, its criticality to human behaviour remains an open question, best addressed with interventional methodology that probes the behavioural consequences of focal neural modulation. Combining a psychometric index of risky decision-making with transient electrical modulation of the nucleus accumbens, here we reveal profound, highly dynamic alteration of the relation between probability of reward and choice during therapeutic deep brain stimulation in four patients with treatment-resistant psychiatric disease. Short-lived phasic electrical stimulation of the region of the nucleus accumbens dynamically altered risk behaviour, transiently shifting the psychometric function towards more risky decisions only for the duration of stimulation. A critical, on-line role of human nucleus accumbens in dynamic risk control is thereby established.

  12. Microtubules move the nucleus to quiescence.

    PubMed

    Laporte, Damien; Sagot, Isabelle

    2014-01-01

    The nucleus is a cellular compartment that hosts several macro-molecular machines displaying a highly complex spatial organization. This tight architectural orchestration determines not only DNA replication and repair but also regulates gene expression. In budding yeast microtubules play a key role in structuring the nucleus since they condition the Rabl arrangement in G1 and chromosome partitioning during mitosis through their attachment to centromeres via the kinetochore proteins. Recently, we have shown that upon quiescence entry, intranuclear microtubules emanating from the spindle pole body elongate to form a highly stable bundle that spans the entire nucleus. Here, we examine some molecular mechanisms that may underlie the formation of this structure. As the intranuclear microtubule bundle causes a profound re-organization of the yeast nucleus and is required for cell survival during quiescence, we discuss the possibility that the assembly of such a structure participates in quiescence establishment.

  13. Dynamic risk control by human nucleus accumbens

    PubMed Central

    Lopez-Sosa, Fernando; Gonzalez-Rosa, Javier Jesus; Galarza, Ana; Avecillas, Josue; Pineda-Pardo, Jose Angel; Lopez-Ibor, Juan José; Reneses, Blanca; Barcia, Juan Antonio

    2015-01-01

    Real-world decisions about reward often involve a complex counterbalance of risk and value. Although the nucleus accumbens has been implicated in the underlying neural substrate, its criticality to human behaviour remains an open question, best addressed with interventional methodology that probes the behavioural consequences of focal neural modulation. Combining a psychometric index of risky decision-making with transient electrical modulation of the nucleus accumbens, here we reveal profound, highly dynamic alteration of the relation between probability of reward and choice during therapeutic deep brain stimulation in four patients with treatment-resistant psychiatric disease. Short-lived phasic electrical stimulation of the region of the nucleus accumbens dynamically altered risk behaviour, transiently shifting the psychometric function towards more risky decisions only for the duration of stimulation. A critical, on-line role of human nucleus accumbens in dynamic risk control is thereby established. PMID:26428667

  14. Differentiating neutrophils using the optical coulter counter

    NASA Astrophysics Data System (ADS)

    Schonbrun, Ethan; Di Caprio, Giuseppe

    2015-11-01

    We present an optofluidic measurement system that quantifies cell volume, dry mass, and nuclear morphology of neutrophils in high-throughput. While current clinical hematology analyzers can differentiate neutrophils from a blood sample, they do not give other quantitative information beyond their count. In order to better understand the distribution of neutrophil phenotypes in a blood sample, we perform two distinct multivariate measurements. In both measurements, white blood cells are driven through a microfluidic channel and imaged while in flow onto a color camera using a single exposure. In the first measurement, we quantify cell volume, scattering strength, and cell dry mass by combining quantitative phase imaging with dye exclusion cell volumetric imaging. In the second measurement, we quantify cell volume and nuclear morphology using a nucleic acid fluorescent stain. In this way, we can correlate cell volume to other cellular characteristics, which would not be possible using an electrical coulter counter. Unlike phase imaging or cell scattering analysis, the optical coulter counter is capable of quantifying cell volume virtually independent of the cell's refractive index and unlike optical tomography, measurements are possible on quickly flowing cells, enabling high-throughput.

  15. Differentiating neutrophils using the optical coulter counter

    NASA Astrophysics Data System (ADS)

    Schonbrun, E.; Di Caprio, G.

    2015-03-01

    We present an opto-fluidic measurement system that quantifies cell volume, dry mass and nuclear morphology of neutrophils in high-throughput. While current clinical hematology analyzers can differentiate neutrophils from a blood sample, they do not give other quantitative information beyond their count. In order to better understand the distribution of neutrophil phenotypes in a blood sample, we perform two distinct multivariate measurements. In both measurements, white blood cells are driven through a microfluidic channel and imaged while in flow onto a color camera using a single exposure. In the first measurement, we quantify cell volume, scattering strength, and cell dry mass by combining quantitative phase imaging with dye exclusion cell volumetric imaging. In the second measurement, we quantify cell volume and nuclear morphology using a nucleic acid fluorescent stain. In this way, we can correlate cell volume to other cellular characteristics, which would not be possible using an electrical coulter counter. Unlike phase imaging or cell scattering analysis, the optical coulter counter is capable of quantifying cell volume virtually independent of the cell's refractive index and unlike optical tomography, measurements are possible on quickly flowing cells, enabling high-throughput.

  16. Finding Feasible Abstract Counter-Examples

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina S.; Dwyer, Matthew B.; Visser, Willem; Clancy, Daniel (Technical Monitor)

    2002-01-01

    A strength of model checking is its ability to automate the detection of subtle system errors and produce traces that exhibit those errors. Given the high computational cost of model checking most researchers advocate the use of aggressive property-preserving abstractions. Unfortunately, the more aggressively a system is abstracted the more infeasible behavior it will have. Thus, while abstraction enables efficient model checking it also threatens the usefulness of model checking as a defect detection tool, since it may be difficult to determine whether a counter-example is feasible and hence worth developer time to analyze. We have explored several strategies for addressing this problem by extending an explicit-state model checker, Java PathFinder (JPF), to search for and analyze counter-examples in the presence of abstractions. We demonstrate that these techniques effectively preserve the defect detection ability of model checking in the presence of aggressive abstraction by applying them to check properties of several abstracted multi-threaded Java programs. These new capabilities are not specific to JPF and can be easily adapted to other model checking frameworks; we describe how this was done for the Bandera toolset.

  17. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Llodra, Anthony; Pooser, Eric; GlueX Collaboration

    2015-04-01

    The GlueX experiment, which is online as of October of 2014, will study meson photo production with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target kept at a few degrees Kelvin. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 nanoseconds apart, and to provide accurate timing information. This detector is designed to operate at photon intensities of up to 108 γ/s in the coherent peak and provide a timing resolution of less than 350 picoseconds so as to provide successful identification of the electron beam buckets. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. The EJ-200 scintillator is best suited for the Start Counter due to its fast decay time on the order of 2 nanoseconds and long attenuation length. Silicon Photo Multiplier (SiPM) detectors have been selected as the readout system and are to be placed as close as possible, less than 300 micron, to the upstream end of each scintillator. The methods/details of the assembly and the optimization of the surface quality of scintillator paddles are discussed. This work was supported in part by DoE Contracts DE-FG02-99ER41065 and DE-AC05-06OR23177.

  18. Counter-sniper 3D laser radar

    NASA Astrophysics Data System (ADS)

    Shepherd, Orr; LePage, Andrew J.; Wijntjes, Geert J.; Zehnpfennig, Theodore F.; Sackos, John T.; Nellums, Robert O.

    1999-01-01

    Visidyne, Inc., teaming with Sandia National Laboratories, has developed the preliminary design for an innovative scannerless 3-D laser radar capable of acquiring, tracking, and determining the coordinates of small caliber projectiles in flight with sufficient precision, so their origin can be established by back projecting their tracks to their source. The design takes advantage of the relatively large effective cross-section of a bullet at optical wavelengths. Kay to its implementation is the use of efficient, high- power laser diode arrays for illuminators and an imaging laser receiver using a unique CCD imager design, that acquires the information to establish x, y (angle-angle) and range coordinates for each bullet at very high frame rates. The detection process achieves a high degree of discrimination by using the optical signature of the bullet, solar background mitigation, and track detection. Field measurements and computer simulations have been used to provide the basis for a preliminary design of a robust bullet tracker, the Counter Sniper 3-D Laser Radar. Experimental data showing 3-D test imagery acquired by a lidar with architecture similar to that of the proposed Counter Sniper 3-D Lidar are presented. A proposed Phase II development would yield an innovative, compact, and highly efficient bullet-tracking laser radar. Such a device would meet the needs of not only the military, but also federal, state, and local law enforcement organizations.

  19. Treatment of evaporator condensates by pervaporation

    DOEpatents

    Blume, Ingo; Baker, Richard W.

    1990-01-01

    A pervaporation process for separating organic contaminants from evaporator condensate streams is disclosed. The process employs a permselective membrane that is selectively permeable to an organic component of the condensate. The process involves contacting the feed side of the membrane with a liquid condensate stream, and withdrawing from the permeate side a vapor enriched in the organic component. The driving force for the process is the in vapor pressure across the membrane. This difference may be provided for instance by maintaining a vacuum on the permeate side, or by condensing the permeate. The process offers a simple, economic alternative to other separation techniques.

  20. Evaporative condensing minimizes system power requirements

    SciTech Connect

    Knebel, D.E.

    1997-04-01

    Evaporative condensing is a heat-rejection technology widely applied with industrial refrigeration. When employed with HVAC systems it can reduce electrical energy and demand consumption of an HVAC system by 20 to 40%, depending on location, compared to air-cooled condensing. Evaporative condensing allows direct-expansion (DX) systems to achieve energy and demand consumption comparable to the most efficient chilled water central plant systems. As the industry focuses its attention on solving the problems of energy conservation, demand reduction, and global warming, high-efficiency air conditioning systems utilizing evaporative condensing provide a reliable and cost-effective solution today. This article addresses the advantages of evaporative condensing over air-cooled and water-cooled condensing in DX packaged systems as well as chiller/cooling tower systems. A review of condensing methods and standard system operating characteristics will be used as examples to illustrate the thermodynamic benefits of evaporative condensing. Requirements for successful operation of evaporative condensers will be discussed.

  1. Vapor condensation on a turbulent liquid interface

    NASA Technical Reports Server (NTRS)

    Helmick, M. R.; Khoo, B. C.; Sonin, A. A.

    1987-01-01

    An experimental investigation which seeks the fundamental relationship between the interfacial condensation rate and the parameters which control it when the liquid side is turbulent is discussed. The scaling laws for free-surface condensation are discussed for this case. It is argued that the condensation of cryogenic liquids can, in principle, be simulated in experiments using steam and water. Data are presented for the condensation rate in terms of the dimensionless scaling parameters which involve the fluid properties and the liquid-side turbulence velocity and length scales.

  2. Advances in modelling of condensation phenomena

    SciTech Connect

    Liu, W.S.; Zaltsgendler, E.; Hanna, B.

    1997-07-01

    The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUF are described.

  3. Combined boiler feed and condensate pump

    SciTech Connect

    Paul Cooper, Titusville, N.J.

    1993-06-01

    A pump for drawing the condensate from a condenser and feeding it to a steam boiler is described, the combination comprising: an elongate casing adapted to be connected in a pipeline having an inlet for receiving the condensate from a steam condenser and an outlet for feeding the condensate to a steam boiler; a pump shaft mounted in said casing rotating in a pair of bearings spaced along said shaft and fixed in said casing; an electric motor mounted in said casing connected to one end of said shaft for driving it; control means for operating said electric motor; an inducer pump mounted at the other end of said shaft, driven by said shaft; a multiple stage centrifugal feed pump located in said casing driven by said shaft and receiving condensate from the inducer pump, pumping said condensate to a higher pressure suitable for feeding a steam boiler and delivering said condensate to the outlet of said pump, the multiple stage centrifugal feed pump being located adjacent said inducer pump; and said inducer pump being of the type to produce sufficient positive pressure for properly feeding condensate to said feed pump.

  4. Interior view of Dispatch Office and counter, facing south ...

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

    Interior view of Dispatch Office and counter, facing south - International Longshoremen's & Warehousemen's Union Hall, Naval Civil Engineering Laboratory, Port Hueneme Road, Port Hueneme, Ventura County, CA

  5. Hardware support for software controlled fast reconfiguration of performance counters

    DOEpatents

    Salapura, Valentina; Wisniewski, Robert W

    2013-09-24

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  6. Hardware support for software controlled fast reconfiguration of performance counters

    DOEpatents

    Salapura, Valentina; Wisniewski, Robert W.

    2013-06-18

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  7. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: NEW CONDENSATOR, INC.--THE CONDENSATOR DIESEL ENGINE RETROFIT CRANKCASE VENTILATION SYSTEM

    EPA Science Inventory

    EPA's Environmental Technology Verification Program has tested New Condensator Inc.'s Condensator Diesel Engine Retrofit Crankcase Ventilation System. Brake specific fuel consumption (BSFC), the ratio of engine fuel consumption to the engine power output, was evaluated for engine...

  8. BFKL Pomeron calculus: solution to equations for nucleus-nucleus scattering in the saturation domain

    NASA Astrophysics Data System (ADS)

    Contreras, Carlos; Levin, Eugene; Meneses, Rodrigo

    2013-04-01

    In this paper we solve the equation for nucleus-nucleus scattering in the BFKL Pomeron calculus, suggested by Braun [1-3]. We find these solutions analytically at high energies as well as numerically in the entire region of energies inside the saturation region. The semi-classical approximation is used to select out the infinite set of the parasite solutions. The nucleus-nucleus cross sections at high energy are estimated and compared with the Glauber-Gribov approach. It turns out that the exact formula gives the estimates that are very close to the ones based on Glauber-Gribov formula which is important for the practical applications.

  9. Compact counter-flow cooling system with subcooled gravity-fed circulating liquid nitrogen

    NASA Astrophysics Data System (ADS)

    Ivanov, Yu.; Radovinsky, A.; Zhukovsky, A.; Sasaki, A.; Watanabe, H.; Kawahara, T.; Hamabe, M.; Yamaguchi, S.

    2010-11-01

    A liquid nitrogen (LN2) is usually used to keep the high-temperature superconducting (HTS) cable low temperature. A pump is utilized to circulate LN2 inside the cryopipes. In order to minimize heat leakage, a thermal siphon circulation scheme can be realized instead. Here, we discuss the effectiveness of thermal siphon with counter-flow circulation loop composed of cryogen flow channel and inner cable channel. The main feature of the system is the existence of essential parasitic heat exchange between upwards and downwards flows. Feasibility of the proposed scheme for cable up to 500 m in length has been investigated numerically. Calculated profiles of temperature and pressure show small differences of T and p in the inner and the outer flows at the same elevation, which allows not worrying about mechanical stability of the cable. In the case under consideration the thermal insulating properties of a conventional electrical insulating material (polypropylene laminated paper, PPLP) appear to be sufficient. Two interesting effects were disclosed due to analysis of subcooling of LN2. In case of highly inclined siphon subcooling causes significant increase of temperature maximum that can breakup of superconductivity. In case of slightly inclined siphon high heat flux from outer flow to inner flow causes condensation of nitrogen gas in outer channel. It leads to circulation loss. Results of numerical analyses indicate that counter-flow thermosiphon cooling system is a promising way to increase performance of short-length power transmission (PT) lines, but conventional subcooling technique should be applied carefully.

  10. Deuteron disintegration in condensed media

    NASA Astrophysics Data System (ADS)

    Ragheb, M.; Miley, G. H.

    1990-12-01

    We discuss the Oppenheimer-Phillips process as a possible phenomenon leading to deuteron disintegration due to polarization in the Coulomb field of a target nucleus. This reaction may be possible in the context of electrochemically compressed deuterons in a palladium cathode. The process is exothermic and may lead to neutron capture from the deuterons into the palladium isotopes, as well as between the deuterons themselves. In the last case, the equivalent of the proton branch of the D-D fusion reaction occurs in preference to the neutron branch. Such a process could provide a model for the processes involved in the observed energy release and tritium production in conjunction with neutron suppression in recent experiments. Possible interactions with Be and fertile isotopes are discussed in the context of breeding fissile isotopes in subcritical configurations.

  11. Demonstration of Nautilus Centripetal Capillary Condenser Technology

    NASA Technical Reports Server (NTRS)

    Wheeler, RIchard; Tang, Linh; Wambolt, Spencer; Golliher, Eric; Agui, Juan

    2016-01-01

    This paper describes the results of a proof of concept effort for development of a Nautilus Centripetal Capillary Condenser (NCCC or NC3) used for microgravity compatible water recovery from moist air with integral passive phase separation. Removal of liquid condensate from the air stream exiting a condenser is readily performed here on Earth. In order to perform this function in space however, without gravity or mechanical action, other tactics including utilization of inertial, drag and capillary forces are required. Within the NC3, liquid water forms via condensation on cold condenser surfaces as humid air passes along multiple spiral channels, each in its own plane, all together forming a stacked plate assembly. Non-mechanical inertial forces are employed to transfer condensate, as it forms, via centripetal action to the outer perimeter of each channel. A V-shaped groove, constructed on this outer edge of the spiral channel, increases local capillary forces thereby retaining the liquid. Air drag then pulls the liquid along to a collection region near the center of the device. Dry air produced by each parallel spiral channel is combined in a common orthogonal, out-of-plane conduit passing down the axial center of the stacked device. Similarly, the parallel condensate streams are combined and removed from the condenser/separator through yet another out-of-plane axial conduit. NC3 is an integration of conventional finned condenser operation, combined with static phase separation and capillary transport phenomena. A Mars' transit mission would be a logical application for this technology where gravity is absent and the use of vibrating, energy-intensive, motor-driven centrifugal separators is undesired. Here a vapor stream from either the Heat Melt Compactor or the Carbon dioxide Reduction Assembly, for example, would be dried to a dew point of 10 deg using a passive NC3 condenser/separator with the precious water condensate recycled to the water bus.

  12. An Experimental Study of Filmwise Condensation on Horizontal Enhanced Condenser Tubing.

    DTIC Science & Technology

    1979-12-01

    with a 51 mm thick sheet of Johns - Manville Aerotube insulation. 22 D. CONDENSATE AND FEEDWATER SYSTEMS The condensate and feedwater systems are shown...desuperheater. The condensate and feedwater lines are insulated with 25.4 mm thick Johns - Manville Aerotube insulation. E. COOLING WATER SYSTEM The cooling

  13. Counterion condensation on heparin oligomers.

    PubMed

    Minsky, Burcu Baykal; Atmuri, Anand; Kaltashov, Igor A; Dubin, Paul L

    2013-04-08

    The electropherogram of native heparin shows a broad distribution of mobilities μ, which truncates abruptly at a notably high μ = 4.7 × 10(-4) cm(2) V(-1) s(-1). This highly skewed mobility distribution is also found for the 20-saccharide chain, which shows from mass spectrometry a more uniform (symmetrical) with respect to sulfation level. Since a partially degraded heparin exhibits oligomer peaks with μ> 5 × 10(-4) cm(2) V(-1) s(-1) (appearing to escape the limitation of the mobility value for native heparin), we examined the electrophoretic behavior of chain-length monodisperse heparin oligomers. Their mobilities varied inversely with the logarithm of the contour length, L, for L from 3 to 10 nm and reached an asymptotic limit for L > 20 nm. The generality of this effect was indicated by similar behavior for oligomers of poly(styrene sulfonate). A recent theory of polyelectrolyte end effects (Manning, G. S. Macromolecules2008, 41, 6217-6227), in which chain termini exhibit reduced counterion condensation was found to quantitatively account for these results. A qualitative explanation for the anomalously high value of μ of native heparin, 10-20% higher than those seen for synthetic polyelectrolytes of higher linear charge density, is suggested on the basis of similar junction effects (Manning, G. S. Macromolecules2008, 41, 6217-6227), which reduce counterion condensation at the interfaces of regions of high and low sulfation. We suggest that these effects should be considered in models for the biofunctionality of the regulated high and low sulfation (NS/NA) domains of heparan sulfate.

  14. Tunable Vapor-Condensed Nanolenses

    PubMed Central

    2015-01-01

    Nanostructured optical components, such as nanolenses, direct light at subwavelength scales to enable, among others, high-resolution lithography, miniaturization of photonic circuits, and nanoscopic imaging of biostructures. A major challenge in fabricating nanolenses is the appropriate positioning of the lens with respect to the sample while simultaneously ensuring it adopts the optimal size and shape for the intended use. One application of particular interest is the enhancement of contrast and signal-to-noise ratio in the imaging of nanoscale objects, especially over wide fields-of-view (FOVs), which typically come with limited resolution and sensitivity for imaging nano-objects. Here we present a self-assembly method for fabricating time- and temperature-tunable nanolenses based on the condensation of a polymeric liquid around a nanoparticle, which we apply to the high-throughput on-chip detection of spheroids smaller than 40 nm, rod-shaped particles with diameter smaller than 20 nm, and biofunctionalized nanoparticles, all across an ultralarge FOV of >20 mm2. Previous nanoparticle imaging efforts across similar FOVs have detected spheroids no smaller than 100 nm, and therefore our results demonstrate the detection of particles >15-fold smaller in volume, which in free space have >240 times weaker Rayleigh scattering compared to the particle sizes detected in earlier wide-field imaging work. This entire platform, with its tunable nanolens condensation and wide-field imaging functions, is also miniaturized into a cost-effective and portable device, which might be especially important for field use, mobile sensing, and diagnostics applications, including, for example, the measurement of viral load in bodily fluids. PMID:24979060

  15. Molecular attraction of condensed bodies

    NASA Astrophysics Data System (ADS)

    Derjaguin, B. V.; Abrikosova, I. I.; Lifshitz, E. M.

    2015-09-01

    From the Editorial Board. As a contribution to commemorating the 100th anniversary of the birth of Evgenii Mikhailovich Lifshitz, it was found appropriate by the Editorial Board of Uspekhi Fizicheskikh Nauk (UFN) [Physics-Uspekhi] journal that the materials of the jubilee-associated Scientific Session of the Physical Sciences Division of the Russian Academy of Sciences published in this issue (pp. 877-905) be augmented by the review paper "Molecular attraction of condensed bodies" reproduced from a 1958 UFN issue. Included in this review, in addition to an account by Evgenii Mikhailovich Lifshitz of his theory of molecular attractive forces between condensed bodies (first published in Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki (ZhETF) in 1955 and in its English translation Journal of Experimental and Theoretical Physics (JETP) in 1956), is a summary of a series of experimental studies beginning in 1949 by Irina Igorevna Abrikosova at the Institute of Physical Chemistry of the Academy of Sciences of the USSR in a laboratory led by Boris Vladimirovich Derjaguin (1902-1994), a Corresponding Member of the USSR Academy of Sciences. In 1958, however, UFN was not yet available in English translation, so the material of the review is insufficiently accessible to the present-day English-speaking reader. This is the reason why the UFN Editorial Board decided to contribute to celebrating the 100th anniversary of E M Lifshitz's birthday by reproducing on the journal's pages a 1958 review paper which contains both E M Lifshitz's theory itself and the experimental data that underpinned it (for an account of how Evgenii Mikhailovich Lifshitz was enlisted to explain the experimental results of I I Abrikosova and B V Derjaguin, see the letter to the editors N P Danilova on page 925 of this jubilee collection of publications).

  16. New technology in condensate polishing

    SciTech Connect

    Kunin, R.; Salem, E.; Libutti, B. . Water Div.)

    1992-08-01

    Sulfonic acid ion exchange resins. when carried into a boiler or steam generator, thermally decompose releasing large amounts of corrosive, sulfates. Replacement of the sulfonic acid resin with a carboxylic acid resin would eliminate this source of contamination. The sulfonic acid resin is a strong acid: the carboxylic acid resin is a weak acid. The carboxylic acid resin alone is not capable of splitting salts which limits its use to mixed resin beds or to its use in single or individual beds with feeds of high alkalinity or high pH values. Laboratory, pilot plant and full scale plant tests compared the two resins in precoat filters. When the resins in mixed beds were in the acid form, the weakly acid resin was almost as effective in removing sodium ion as the strongly acid resin. In the ammonium form. the weakly acid resin was generally more effective in removing sodium than the strongly acid resin. Condensate polishing reduced the sodium ion to a few parts per billion (ppB). Complete resin separation before regeneration is more important for the weakly acid resin than for the strongly acid resin. Another development found that the hydrazine reaction with oxygen could be catalyzed by powdered activated carbon combined with microfibers on a Powdex substrate. The carbon should be thoroughly washed to reduce its residual sodium content. In plant tests, the carbon reduced the oxygen concentration in condensate about 50% during startup. In preliminary tests believed to be typical, carbon lowered the oxygen concentration below 10 ppB in about 6 hours compared to 18 hours without the carbon. Oxygen is also reduced during normal operation.

  17. CFD simulation of water vapour condensation in the presence of non-condensable gas in vertical cylindrical condensers

    PubMed Central

    Li, Jun-De

    2013-01-01

    This paper presents the simulation of the condensation of water vapour in the presence of non-condensable gas using computational fluid dynamics (CFD) for turbulent flows in a vertical cylindrical condenser tube. The simulation accounts for the turbulent flow of the gas mixture, the condenser wall and the turbulent flow of the coolant in the annular channel with no assumptions of constant wall temperature or heat flux. The condensate film is assumed to occupy a negligible volume and its effect on the condensation of the water vapour has been taken into account by imposing a set of boundary conditions. A new strategy is used to overcome the limitation of the currently available commercial CFD package to solve the simultaneous simulation of flows involving multispecies and fluids of gas and liquid in separate channels. The results from the CFD simulations are compared with the experimental results from the literature for the condensation of water vapour with air as the non-condensable gas and for inlet mass fraction of the water vapour from 0.66 to 0.98. The CFD simulation results in general agree well with the directly measured quantities and it is found that the variation of heat flux in the condenser tube is more complex than a simple polynomial curve fit. The CFD results also show that, at least for flows involving high water vapour content, the axial velocity of the gas mixture at the interface between the gas mixture and the condensate film is in general not small and cannot be neglected. PMID:24850953

  18. Sagnac interferometry with coherent vortex superposition states in exciton-polariton condensates

    NASA Astrophysics Data System (ADS)

    Moxley, Frederick Ira; Dowling, Jonathan P.; Dai, Weizhong; Byrnes, Tim

    2016-05-01

    We investigate prospects of using counter-rotating vortex superposition states in nonequilibrium exciton-polariton Bose-Einstein condensates for the purposes of Sagnac interferometry. We first investigate the stability of vortex-antivortex superposition states, and show that they survive at steady state in a variety of configurations. Counter-rotating vortex superpositions are of potential interest to gyroscope and seismometer applications for detecting rotations. Methods of improving the sensitivity are investigated by targeting high momentum states via metastable condensation, and the application of periodic lattices. The sensitivity of the polariton gyroscope is compared to its optical and atomic counterparts. Due to the large interferometer areas in optical systems and small de Broglie wavelengths for atomic BECs, the sensitivity per detected photon is found to be considerably less for the polariton gyroscope than with competing methods. However, polariton gyroscopes have an advantage over atomic BECs in a high signal-to-noise ratio, and have other practical advantages such as room-temperature operation, area independence, and robust design. We estimate that the final sensitivities including signal-to-noise aspects are competitive with existing methods.

  19. Dynamical evolution of comet nucleus rotation

    NASA Astrophysics Data System (ADS)

    Scheeres, D. J.; Sidorenko, V. V.; Neishtadt, A. I.; Vasiliev, A. A.

    2001-11-01

    The rotational dynamics of outgassing cometary nuclei are investigated analytically using dynamical systems theory. We develop a general theory for the averaged evolution of a comet nucleus rotation state assuming that the nucleus is a spheroid (either prolate or oblate) and that the outgassing torques are a function of solar insolation and heliocentric distance. The resulting solutions are a function of the comet outgassing properties, its heliocentric orbit, and the assumed distribution of active regions on its surface. We find that the long-term evolution of the comet nucleus rotation is a strong function of the distribution of active regions over its surface. Specifically, we find that a comet nucleus with a uniformly active surface will tend towards a rotation state with a nutation angle of ~ 55 degrees and an angular momentum perpendicular to the sun-perihelion direction. Conversely, a comet nucleus with an isolated active region will tend towards a zero nutation angle with its symmetry axis and angular momentum aligned parallel to the sun-perihelion direction. For active surface regions between these extremes we find 4 qualitatively different dynamical outcomes. In all cases, the theory predicts that the comet nucleus angular momentum will have a secular increase, a phenomenon that could contribute to nucleus splitting of active comets. These results can be used to discriminate between competing theories of comet outgassing based on a nucelus' rotation state. They also allow for a range of plausible a priori constraints to be placed on a comet's rotation state to aid in the interpretation of its outgassing structure. This work was supported by the NASA JURRISS program under Grant NAG5-8715. AIN, AAV and VVS acknowledge support from Russian Foundation for Basic research via Grants 00-01-00538 and 00-01-0174 respectively. DJS acknowledges support from the PG&G program via Grant NAG5-9017.

  20. Fast-neutron coincidence-counter manual

    SciTech Connect

    Ensslin, N.; Atwell, T.L.; Lee, D.M.; Erkkila, B.; Marshall, R.S.; Morgan, A.; Shonrock, C.; Tippens, B.; Van Lyssel, T.

    1982-03-01

    The fast neutron counter (FNC) described in this report is a computer-based assay system employing fast-pulse counting instrumentation. It is installed below a glove box in the metal electrorefining area of the Los Alamos National Laboratory Plutonium Processing Facility. The instrument was designed to assay plutonium salts and residues from this process and to verify the mass of electrorefined metal. Los Alamos National Laboratory Groups Q-1, Q-3, and CMB-11 carried out a joint test and evaluation plan of this instrument between May 1978 and May 1979. The results of that evaluation, a description of the FNC, and operating instructions for further use are given in this report.

  1. Microstrip proportional counter development at MSFC

    NASA Technical Reports Server (NTRS)

    Fulton, M. A.; Kolodziejczak, J. J.; Ramsey, B. D.

    1992-01-01

    Microstrip detectors are an exciting new development in proportional counter design fabricated using integrated circuit-type photolithography techniques; they therefore offer very high spatial accuracy and uniformity. A development program is underway at NASA-Marshall to produce large-area microstrips for use in an X-ray detector balloon flight program and to investigate the general performance limits of these new devices. Microstrips tested so far have been fabricated both in-house using standard photolithographic techniques and by an outside contractor using electron beam technology. Various substrate materials have been tested along with different electrode configurations. The distributions of pickup on subdivided cathodes on both top and bottom surfaces of the microstrips are also being investigated for use as two-dimensional imaging detectors. Data from these tests in the development of a large-area device will be presented.

  2. Actively suspended counter-rotating machine

    NASA Technical Reports Server (NTRS)

    Studer, Philip A. (Inventor)

    1983-01-01

    A counter-rotating machine, such as a positive displacement pump having a pair of meshed, non-contacting helical screws (10,12), subjects its rotating members to axial and radial thrust forces when used for such purposes as compression of liquid or gaseous phase fluids while transporting them through a pump cavity (11,13). Each helical screw (10,12) has a shaft (17,17') which is actively suspended at opposite ends (11a,11b) of the pump cavity by a servo-controlled magnetic bearing assembly (19) and a servo-controlled rotary drive motor (20). Both bearing assemblies and drive motors are mounted on the outside of the pump cavity (11,13). Opto-electric angular position sensors (250) provide synchronization between radial orientation of the drive motors. The bearing assemblies and drive motors conjugately provide axial stabilization and radial centering of the helical screws during volumetric compression of aspirated liquid or gaseous phase fluids.

  3. Dynamic Condensation of Mass and Stiffness Matrices

    NASA Astrophysics Data System (ADS)

    Zhang, N.

    1995-12-01

    Details are given of a procedure for condensing the mass and stiffness matrices of a structure for dynamic analysis. The condensed model is based on choosing ncnatural frequencies and the corresponding modes of original model. The model is constructed so that (1) it has ncnatural frequencies equal to those of the original model, (2) the modes φ ifcless than i,j = 1, 2, . . . , ncare the same as those for the master co-ordinates in the corresponding modes of the original and (3) the responses of the condensed system at the co-ordinates Xcdue to forces at these co-ordinates, at one particular chosen frequency, are the same as those of the original system. The natural frequencies, the corresponding modes and the dynamic responses used for the condensation can be obtained from finite element analysis of the original structure. The method has been applied to the modelling of two common structures to examine its applicability. Comparisons between the performance of the condensed models obtained by means of the dynamic condensation method and that of the models obtained by the Guyan method have been conducted. The results of the example show that the condensed models determined by the dynamic condensation method retain the natural frequencies and modal shapes and perform better in describing the dynamic responses of the structures than do the corresponding models obtained by the Guyan method.

  4. Drinking influences exhaled breath condensate acidity.

    PubMed

    Kullmann, Tamás; Barta, Imre; Antus, Balázs; Horváth, Ildikó

    2008-01-01

    Exhaled breath condensate analysis is a developing method for investigating airway pathology. Impact of food and drink on breath condensate composition has not been systematically addressed. The aim of the study was to follow exhaled breath condensate pH after drinking an acidic and a neutral beverage. Breath condensate, capillary blood, and urine of 12 healthy volunteers were collected before and after drinking either 1 l of coke or 1 l of mineral water. The pH of each sample was determined with a blood gas analyzer. The mean difference between the pH of two breath condensate samples collected within 15 min before drinking was 0.13+/-0.03. Condensate pH decreased significantly from 6.29+/-0.02 to 6.24+/-0.02 (p<0.03) after drinking coke and from 6.37+/-0.03 to 6.22+/-0.04 (p<0.003) after drinking water. Drinking coke induced significant changes in blood and urine pH as well. Drinking influences exhaled breath condensate composition and may contribute to the variability of exhaled breath condensate pH.

  5. Soliton resonance in bose-einstein condensate

    NASA Technical Reports Server (NTRS)

    Zak, Michail; Kulikov, I.

    2002-01-01

    A new phenomenon in nonlinear dispersive systems, including a Bose-Einstein Condensate (BEC), has been described. It is based upon a resonance between an externally induced soliton and 'eigen-solitons' of the homogeneous cubic Schrodinger equation. There have been shown that a moving source of positive /negative potential induces bright /dark solitons in an attractive / repulsive Bose condensate.

  6. Nephron induction revisited: from caps to condensates.

    PubMed

    Sariola, Hannu

    2002-01-01

    Conversion of mesenchyme to epithelium in the metanephric kidney is clearly a multimolecular, multistep and partly redundant process. The present short review focuses on a neglected morphological aspect of kidney differentiation: the development of two transitory mesenchymal condensations that precede epithelial differentiation of nephrons. The first appearing condensate covers the tips of the collecting ducts and is termed a cap condensate. In the early kidney rudiment this structure has been referred to as a primary or early condensate. A few cells of the cap condensate (maybe only four to six cells), situated at the lateral edge of the cap, start proliferating rapidly and form a pretubular aggregate (or pretubular condensate), which converts to secretory nephron epithelia and finally segregates to different tubule segments. Throughout nephrogenesis, the cap condensates and pretubular aggregates are clearly distinguishable structures that show only partly overlapping gene expression profiles. Apart from being the source for the pretubular aggregates, the role of the cap condensate is unknown. It is now proposed that the cap regulates ureteric branching morphogenesis.

  7. Proceedings: 2002 Workshop on Condensate Polishing

    SciTech Connect

    2002-06-01

    Condensate polishing aims to control impurities in a nuclear power plant, thus allowing the unit to operate more reliably. This report contains the work presented at EPRI's 2002 Workshop on Condensate Polishing, where 36 papers were presented on current issues, research, and utility experiences involving polishing issues at both pressurized water reactor (PWR) and boiling water reactor (BWR) units.

  8. Fragmentation of Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Mueller, Erich J.; Ho, Tin-Lun; Ueda, Masahito; Baym, Gordon

    2006-09-01

    We present the theory of bosonic systems with multiple condensates, providing a unified description of various model systems that are found in the literature. We discuss how degeneracies, interactions, and symmetries conspire to give rise to this unusual behavior. We show that as degeneracies multiply, so do the varieties of fragmentation, eventually leading to strongly correlated states with no trace of condensation.

  9. Enhancement of Condensation on a Vertical Plate

    NASA Astrophysics Data System (ADS)

    Chu, Rencai; Hatanaka, Tsutomu; Nishio, Shigefumi

    In previous study, the characteristic of the condensation heat transfer on the dispersed vertical surface were investigated experimentally for the application of the finned surface to the thermoelectric generator utilizing boiling and condensation as the electrodes of the thermoelectric module. A prediction model for this diapered finned surface was proposed, based on Adamek-Webb model of the condensation on a finned tube. In this study, a condensation heat transfer experiment on a vertical dispersed finned surfaces using FC5312 was carried out, in order to enhance the condensation heat transfer coefficient by optimizing the fin size on a dispersed heat transfer surface. Experimental parameters were the fin width, thickness, height and the dispersed fin length. As the results, it was found from the experiment there was a dispersed fin length corresponding to the condensation at the maximum and its value was 1.75 mm. As the characteristic, the condensation changed from slowly increasing to rapidly increasing and then decreasing at a steep grade, with decreasing the dispersed fin length. In addition, the fin height did not affect this optimum dispersed fin length and the dispersed fin length affects the dependence of the condensation on different fin thickness. Further, the prediction values have a good agreement with the experimental data except the case of short dispersed fin length.

  10. Hydrophilic structures for condensation management in appliances

    DOEpatents

    Kuehl, Steven John; Vonderhaar, John J.; Wu, Guolian; Wu, Mianxue

    2016-02-02

    An appliance that includes a cabinet having an exterior surface; a refrigeration compartment located within the cabinet; and a hydrophilic structure disposed on the exterior surface. The hydrophilic structure is configured to spread condensation. The appliance further includes a wicking structure located in proximity to the hydrophilic structure, and the wicking structure is configured to receive the condensation.

  11. Collision of Bose Condensate Dark Matter structures

    SciTech Connect

    Guzman, F. S.

    2008-12-04

    The status of the scalar field or Bose condensate dark matter model is presented. Results about the solitonic behavior in collision of structures is presented as a possible explanation to the recent-possibly-solitonic behavior in the bullet cluster merger. Some estimates about the possibility to simulate the bullet cluster under the Bose Condensate dark matter model are indicated.

  12. The Counter Terrorist Classroom: Religion, Education, and Security

    ERIC Educational Resources Information Center

    Gearon, Liam

    2013-01-01

    The article identifies international cases--from the United States, Europe, and the United Nations--of an emergent interface of religion, education, and security. This is manifest in the uses of religion in education to counter religious extremism, the notional "counter terrorist classroom." To avoid an over-association of extremism with…

  13. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated differential cell counter. 864.5220... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell... have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the...

  14. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated differential cell counter. 864.5220... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell... have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the...

  15. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated differential cell counter. 864.5220... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell... have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the...

  16. Using a PC as a Frequency Meter or a Counter.

    ERIC Educational Resources Information Center

    Sartori, J.; And Others

    1995-01-01

    Describes hardware that enables the use of an IBM PC microcomputer as a frequency meter or a counter by using the parallel printer port. Eliminates the 16-bit time-day counter through the use of an external time base that can be conveniently set depending on the desired frequency range. (JRH)

  17. Analog Microcontroller Model for an Energy Harvesting Round Counter

    DTIC Science & Technology

    2012-07-01

    Technical Report ARWSB-TR-12012 Analog Microcontroller Model for an Energy Harvesting Round Counter Sara...YYYY) 06-06-2012 2. REPORT TYPE FINAL 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Analog Microcontroller Model for an Energy ... Microcontroller The greatest energy requirements of the round counter circuitry are associated with the Microchip PIC12LF1822 microcontroller [4]. An analog

  18. Automatic platelet counting with the Coulter particle counter

    PubMed Central

    Davis, R. E.; Green, R. E.

    1967-01-01

    A method for accurately counting platelets is described using the Coulter counter model B fitted with a standard 100μ aperture tube. This enables the counter to be used for red and white cell as well as platelet counts using the same aperture tube. The method uses standard equipment except for a small inexpensive electronic speed controller. PMID:5602990

  19. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated differential cell counter. 864.5220... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell... have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the...

  20. 21 CFR 864.5220 - Automated differential cell counter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated differential cell counter. 864.5220... § 864.5220 Automated differential cell counter. (a) Identification. An automated differential cell... have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the...

  1. Drugs, Race, The Counter Culture and the Soldier.

    ERIC Educational Resources Information Center

    Fitzsimons General Hospital, Denver, CO.

    This week long conference of senior and junior ranking military officers along with civilians dealt with military social work in the content areas of drugs and race. Theodore Roszak's concept of Counter Culture provided the unifying theme. The following papers were presented: 1) The Theme of the Counter-Culture; 2) Drugs, Race and the Counter…

  2. 11. Detail view of the original counter and builtin merchandise ...

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

    11. Detail view of the original counter and built-in merchandise drawers along the store's east wall; open shelving for dry goods can be seen above the counter; looking northeast - Horsepasture Store, U.S. Route 58 & State Route 687, Horse Pasture, Henry County, VA

  3. Four pi-recoil proportional counter used as neutron spectrometer

    NASA Technical Reports Server (NTRS)

    Bennett, E. F.

    1968-01-01

    Study considers problems encountered in using 4 pi-recoil counters for neutron spectra measurement. Emphasis is placed on calibration, shape discrimination, variation of W, the average energy loss per ion pair, and the effects of differentiation on the intrinsic counter resolution.

  4. Film condensation in a horizontal rectangular duct

    NASA Technical Reports Server (NTRS)

    Lu, Qing; Suryanarayana, N. V.

    1993-01-01

    Condensation heat transfer in a horizontal rectangular duct was experimentally and analytically investigated. To prevent the dripping of condensate on the film, the experiment was conducted inside a horizontal rectangular duct with vapor condensing only on the bottom cooled plate of the duct. R-113 and FC-72 (Fluorinert Electronic Fluid developed by the 3M Company) were used as the condensing fluids. The experimental program included measurements of film thickness, local and average heat transfer coefficients, wave length, wave speed, and a study of wave initiation. The measured film thickness was used to obtain the local heat transfer coefficient. The wave initiation was studied both with condensation and with an adiabatic air-liquid flow. The test sections used in both experiments were identical.

  5. Direct measurement of activation time and nucleation rate in capillary-condensed water nanomeniscus

    NASA Astrophysics Data System (ADS)

    Sung, Baekman; Kim, Jongwoo; Stambaugh, Corey; Chang, Sung-Jin; Jhe, Wonho

    2013-11-01

    We demonstrate real-time observation of nucleation of the single water nanomeniscus formed via capillary condensation. We directly measure (i) activation time by time-resolved atomic force microscopy and (ii) nucleation rate by statistical analysis of its exponential distribution, which is the experimental evidence that the activation process is stochastic and follows the Poisson statistics. It implies that formation of the water nanomeniscus is triggered by nucleation, which requires activation for producing a nucleus. We also find the dependence of the nucleation rate on the tip-sample distance and temperature.

  6. What is the link of the abundances of volatile species in the coma with the ones in the nucleus ?

    NASA Astrophysics Data System (ADS)

    Marboeuf, U.; Schmitt, B.

    2014-04-01

    The chemical composition of comets is frequently assumed to be directly provided by the observations of the abundances of volatile molecules in the coma. The present work aims to determine the relationship between the chemical composition of the coma, the outgassing profile of volatile molecules and the physicochemical composition of the nucleus. To do this, we have developed a quasi 3D model of a cometary nucleus which takes into account all phase changes and water ice structures and applied this model to the comet 67P/Churyumov-Gerasimenko, the target of the Rosetta mission. We find that the outgassing profile of volatile molecules is a strong indicator of the physical and thermal properties of the solid nucleus. The relative abundance (to H2O) of volatile molecules released from the nucleus interior varies by some orders of magnitude as a function of the distance to the sun, the volatility of species, their abundance and distribution between the 'trapped' and 'condensed' states, the structure of water ice, and the thermal inertia and other physical assumptions (dust mantle, ...) on the nucleus.

  7. High Resolution Radio Imaging of the Nucleus of NGC 1275

    NASA Astrophysics Data System (ADS)

    Dhawan, V.; Kellermann, K. I.; Romney, J. D.

    1995-03-01

    We have used the VLBA to observe the nucleus of NGC 1275 at 15 and 43 GHz with angular resolution of 1.0 and 0.3 milliarcsec, respectively. Our observations reveal a bright core and two-sided, more extended structure. The peak intensity of the more prominent, southward-extending jet is located at a distance from the core consistent with apparent subluminal motion at 0.58 c (for H_0 = 50 km s(-1) Mpc(-1) ), continuing since this velocity was first measured (J. D. Romney, W. Alef, I. I. K. Pauliny-Toth, E. Preuss, & K. I. Kellermann 1982, in I. A. U. Symposium No. 97: Extragalactic Radio Sources, p. 291) from primitive maps made in 1979-81. The northward ``counter-jet'' extension is well detected at 15 GHz, with intensity relative to the core intermediate between the two observations at 8.4 GHz (R. C. Walker, J. D. Romney, & J. M. Benson 1994, ApJ, 430, L45) and at 22 GHz (R. C. Vermeulen, A. C. S. Readhead, & D. C. Backer 1994, ApJ, 430, L41) in which this feature was first discovered. In our observations at 43 GHz, the counter-jet is detected, but barely so. Both results are consistent with the model proposed by Vermeulen, Readhead, and Backer, in which the inverted spectrum of this component is a result of free-free absorption in a toroidal or disk-like region. Our 43-GHz observations resolve the core into two bright components separated by about 0.5 milliarcsec in a position angle close to the -9 degrees seen at 10-milliarcsec and indeed at much larger angular scales. A more diffuse structure extends about 1.1 milliarcsec at 45 degrees position angle from the more southerly of the two bright components, and then bends back to the original orientation. This structure is quite different from that seen previously at this frequency. Indications of large position-angle changes in the core on timescales of perhaps six months can be seen in our previous maps at 15, 10.7, and at 8.4 GHz as well.

  8. DETAIL VIEW OF MARISCAL WORKS CONDENSER STACK, THE END OF ...

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

    DETAIL VIEW OF MARISCAL WORKS CONDENSER STACK, THE END OF THE CONDENSING SYSTEM, REUSED BY VIVIANNA WORKS AS THE END OF THEIR CONDENSING SYSTEM, LOOKING SOUTHWEST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  9. 26. DETAIL VIEW OF MARISCAL WORKS CONDENSER STACK, THE END ...

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

    26. DETAIL VIEW OF MARISCAL WORKS CONDENSER STACK, THE END OF THE CONDENSING SYSTEM, REUSED BY VIVIANNA WORKS AS THE END OF THEIR CONDENSING SYSTEM, LOOKING SOUTHWEST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  10. Early stage of Superradiance from Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Buchmann, Lukas

    2011-05-01

    We investigate the dynamics of matter and optical waves at the early stage of superradiant Rayleigh scattering from Bose-Einstein condensates, an instance of four-wave-mixing of matter and optical waves. Our analysis is within a spatially dependent model which treats the matter-waves as well as the optical end-fire modes quantum mechanically and is capable of providing analytic solutions for the operators of interest. In particular, we study the statistical properties of the outgoing scattered light which provide insight into the rich internal dynamics of the system at this early stage. Furthermore, we investigate coherence properties of pairs of counter propagating atomic sidemodes produced during the process. It is shown that these clouds exhibit long-range spatial coherence and strong nonclassical density cross-correlations due to entanglement between the clouds. These findings make this scheme a promising candidate for the production of highly directional nonclassically correlated atomic pulses. Our prediction of number difference squeezing between the clouds was observed in another instance of a four-wave mixing process using metastable helium. Work performed at IESL-FORTH in Crete, Greece

  11. Vortex dynamics in coherently coupled Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Calderaro, Luca; Fetter, Alexander L.; Massignan, Pietro; Wittek, Peter

    2017-02-01

    In classical hydrodynamics with uniform density, vortices move with the local fluid velocity. This description is rewritten in terms of forces arising from the interaction with other vortices. Two such positive straight vortices experience a repulsive interaction and precess in a positive (anticlockwise) sense around their common centroid. A similar picture applies to vortices in a two-component, two-dimensional uniform Bose-Einstein condensate (BEC) coherently coupled through rf Rabi fields. Unlike the classical case, however, the rf Rabi coupling induces an attractive interaction and two such vortices with positive signs now rotate in the negative (clockwise) sense. Pairs of counter-rotating vortices are instead found to translate with uniform velocity perpendicular to the line joining their cores. This picture is extended to a single vortex in a two-component trapped BEC. Although two uniform vortex-free components experience familiar Rabi oscillations of particle-number difference, such behavior is absent for a vortex in one component because of the nonuniform vortex phase. Instead the coherent Rabi coupling induces a periodic vorticity transfer between the two components.

  12. The dynamic landscape of the cell nucleus.

    PubMed

    Austin, Christopher M; Bellini, Michel

    2010-01-01

    While the cell nucleus was described for the first time almost two centuries ago, our modern view of the nuclear architecture is primarily based on studies from the last two decades. This surprising late start coincides with the development of new, powerful strategies to probe for the spatial organization of nuclear activities in both fixed and live cells. As a result, three major principles have emerged: first, the nucleus is not just a bag filled with nucleic acids and proteins. Rather, many distinct functional domains, including the chromosomes, resides within the confines of the nuclear envelope. Second, all these nuclear domains are highly dynamic, with molecules exchanging rapidly between them and the surrounding nucleoplasm. Finally, the motion of molecules within the nucleoplasm appears to be mostly driven by random diffusion. Here, the emerging roles of several subnuclear domains are discussed in the context of the dynamic functions of the cell nucleus.

  13. Organisation of the human dorsomedial hypothalamic nucleus.

    PubMed

    Koutcherov, Yuri; Mai, Juergen K; Ashwell, Ken W; Paxinos, George

    2004-01-19

    This study used acetylcholinesterase (AChE) histochemistry to reveal the organization of the dorsomedial hypothalamic nucleus (DM) in the human. Topographically, the human DM is similar to DM in the monkey and rat. It is wedged between the paraventricular nucleus, dorsally, and the ventromedial nucleus, ventrally. Laterally, DM borders the lateral hypothalamic area while medially it approaches the 3rd ventricle. The AChE staining distinguished two subcompartments of the human DM: the larger diffuse and the smaller compact DM. The subcompartmental organization of the human DM appears homologous to that found in the monkey and less complex than that reported in rats. Understanding of the organization of DM creates meaningful anatomical reference for physiological and pharmacological studies in the human hypothalamus.

  14. Enhancing dropwise condensation through bioinspired wettability patterning.

    PubMed

    Ghosh, Aritra; Beaini, Sara; Zhang, Bong June; Ganguly, Ranjan; Megaridis, Constantine M

    2014-11-04

    Dropwise condensation (DWC) heat transfer depends strongly on the maximum diameter (Dmax) of condensate droplets departing from the condenser surface. This study presents a facile technique implemented to gain control of Dmax in DWC within vapor/air atmospheres. We demonstrate how this approach can enhance the corresponding heat transfer rate by harnessing the capillary forces in the removal of the condensate from the surface. We examine various hydrophilic-superhydrophilic patterns, which, respectively, sustain and combine DWC and filmwise condensation on the substrate. The material system uses laser-patterned masking and chemical etching to achieve the desired wettability contrast and does not employ any hydrophobizing agent. By applying alternating straight parallel strips of hydrophilic (contact angle ∼78°) mirror-finish aluminum and superhydrophilic regions (etched aluminum) on the condensing surface, we show that the average maximum droplet size on the less-wettable domains is nearly 42% of the width of the corresponding strips. An overall improvement in the condensate collection rate, up to 19% (as compared to the control case of DWC on mirror-finish aluminum) was achieved by using an interdigitated superhydrophilic track pattern (on the mirror-finish hydrophilic surface) inspired by the vein network of plant leaves. The bioinspired interdigitated pattern is found to outperform the straight hydrophilic-superhydrophilic pattern design, particularly under higher humidity conditions in the presence of noncondensable gases (NCG), a condition that is more challenging for maintaining sustained DWC.

  15. Boson condensation in topologically ordered quantum liquids

    NASA Astrophysics Data System (ADS)

    Neupert, Titus; He, Huan; von Keyserlingk, Curt; Sierra, Germán; Bernevig, B. Andrei

    2016-03-01

    Boson condensation in topological quantum field theories (TQFT) has been previously investigated through the formalism of Frobenius algebras and the use of vertex lifting coefficients. While general, this formalism is physically opaque and computationally arduous: analyses of TQFT condensation are practically performed on a case by case basis and for very simple theories only, mostly not using the Frobenius algebra formalism. In this paper, we provide a way of treating boson condensation that is computationally efficient. With a minimal set of physical assumptions, such as commutativity of lifting and the definition of confined particles, we can prove a number of theorems linking Boson condensation in TQFT with chiral algebra extensions, and with the factorization of completely positive matrices over Z+. We present numerically efficient ways of obtaining a condensed theory fusion algebra and S matrices; and we then use our formalism to prove several theorems for the S and T matrices of simple current condensation and of theories which upon condensation result in a low number of confined particles. We also show that our formalism easily reproduces results existent in the mathematical literature such as the noncondensability of five and ten layers of the Fibonacci TQFT.

  16. Diquark Bose-Einstein condensation

    SciTech Connect

    Nawa, K.; Nakano, E.; Yabu, H.

    2006-08-01

    Bose-Einstein condensation of composite diquarks in quark matter (the color superconductor phase) is discussed using the quasichemical equilibrium theory at a relatively low-density region near the deconfinement phase transition, where dynamical quark-pair fluctuations are assumed to be described as bosonic degrees of freedom (diquarks). A general formulation is given for the diquark formation and particle-antiparticle pair-creation processes in the relativistic framework, and some interesting properties are shown, which are characteristic for the relativistic many-body system. Behaviors of transition temperature and phase diagram of the quark-diquark matter are generally presented in model parameter space, and their asymptotic behaviors are also discussed. As an application to the color superconductivity, the transition temperatures and the quark and diquark density profiles are calculated in case with constituent/current quarks, where the diquark is in the bound/resonant state. We obtained T{sub C}{approx}60-80 MeV for constituent quarks and T{sub C}{approx}130 MeV for current quarks at a moderate density ({rho}{sub b}{approx}3{rho}{sub 0}). The method is also developed to include interdiquark interactions into the quasichemical equilibrium theory within a mean-field approximation, and it is found that a possible repulsive diquark-diquark interaction lowers the transition temperature by {approx}50%.

  17. Condensation Processes in Astrophysical Environments

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A., III; Rietmeijer, Frans J. M.; Hill, Hugh G. M.

    2002-01-01

    Astrophysical systems present an intriguing set of challenges for laboratory chemists. Chemistry occurs in regions considered an excellent vacuum by laboratory standards and at temperatures that would vaporize laboratory equipment. Outflows around Asymptotic Giant Branch (AGB) stars have timescales ranging from seconds to weeks depending on the distance of the region of interest from the star and, on the way significant changes in the state variables are defined. The atmospheres in normal stars may only change significantly on several billion-year timescales. Most laboratory experiments carried out to understand astrophysical processes are not done at conditions that perfectly match the natural suite of state variables or timescales appropriate for natural conditions. Experimenters must make use of simple analog experiments that place limits on the behavior of natural systems, often extrapolating to lower-pressure and/or higher-temperature environments. Nevertheless, we argue that well-conceived experiments will often provide insights into astrophysical processes that are impossible to obtain through models or observations. This is especially true for complex chemical phenomena such as the formation and metamorphism of refractory grains under a range of astrophysical conditions. Data obtained in our laboratory has been surprising in numerous ways, ranging from the composition of the condensates to the thermal evolution of their spectral properties. None of this information could have been predicted from first principals and would not have been credible even if it had.

  18. Ice-condenser aerosol tests

    SciTech Connect

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. )

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

  19. Nucleus model for periodic Comet Tempel 2

    NASA Technical Reports Server (NTRS)

    Sekanina, Zdenek

    1991-01-01

    Observational data obtained primarily during 1988 are analyzed and synthesized to develop a comprehensive physical model for the nucleus of Periodic Comet Tempel 2, one of the best studied members of Jupiter's family of short-period comets. It is confirmed that a previous investigation provided reliable information on the comet's spin-axis orientation, which implies and obliquity of 54 degrees of the orbit plane to the equatorial plane and which appears to have varied little - if at all - with time. This conclusion is critical for fitting a triaxial ellipsoid to approximate the figure of the nucleus.

  20. UNCOVERING THE NUCLEUS CANDIDATE FOR NGC 253

    SciTech Connect

    Günthardt, G. I.; Camperi, J. A.; Agüero, M. P.; Díaz, R. J.; Gomez, P. L.; Schirmer, M.; Bosch, G. E-mail: camperi@oac.uncor.edu E-mail: rdiaz@gemini.edu E-mail: mschirmer@gemini.edu

    2015-11-15

    NGC 253 is the nearest spiral galaxy with a nuclear starburst that becomes the best candidate for studying the relationship between starburst and active galactic nucleus activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus to the point that there is no strong evidence that the galaxy harbors a supermassive black hole co-evolving with the starburst as was supposed earlier. Near-infrared (NIR) spectroscopy, especially NIR emission line analysis, could be advantageous in shedding light on the true nucleus identity. Using Flamingos-2 at Gemini South we have taken deep K-band spectra along the major axis of the central structure and through the brightest infrared source. In this work, we present evidence showing that the brightest NIR and mid-infrared source in the central region, already known as radio source TH7 and so far considered just a large stellar supercluster, in fact presents various symptoms of a genuine galactic nucleus. Therefore, it should be considered a valid nucleus candidate. Mentioning some distinctive aspects, it is the most massive compact infrared object in the central region, located at 2.″0 of the symmetry center of the galactic bar, as measured in the K-band emission. Moreover, our data indicate that this object is surrounded by a large circumnuclear stellar disk and it is also located at the rotation center of the large molecular gas disk of NGC 253. Furthermore, a kinematic residual appears in the H{sub 2} rotation curve with a sinusoidal shape consistent with an outflow centered in the candidate nucleus position. The maximum outflow velocity is located about 14 pc from TH7, which is consistent with the radius of a shell detected around the nucleus candidate, observed at 18.3 μm (Qa) and 12.8 μm ([Ne ii]) with T-ReCS. Also, the Brγ emission line profile shows a pronounced blueshift and this emission line also has the highest equivalent width at this

  1. Uncovering the Nucleus Candidate for NGC 253

    NASA Astrophysics Data System (ADS)

    Günthardt, G. I.; Agüero, M. P.; Camperi, J. A.; Díaz, R. J.; Gomez, P. L.; Bosch, G.; Schirmer, M.

    2015-11-01

    NGC 253 is the nearest spiral galaxy with a nuclear starburst that becomes the best candidate for studying the relationship between starburst and active galactic nucleus activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus to the point that there is no strong evidence that the galaxy harbors a supermassive black hole co-evolving with the starburst as was supposed earlier. Near-infrared (NIR) spectroscopy, especially NIR emission line analysis, could be advantageous in shedding light on the true nucleus identity. Using Flamingos-2 at Gemini South we have taken deep K-band spectra along the major axis of the central structure and through the brightest infrared source. In this work, we present evidence showing that the brightest NIR and mid-infrared source in the central region, already known as radio source TH7 and so far considered just a large stellar supercluster, in fact presents various symptoms of a genuine galactic nucleus. Therefore, it should be considered a valid nucleus candidate. Mentioning some distinctive aspects, it is the most massive compact infrared object in the central region, located at 2.″0 of the symmetry center of the galactic bar, as measured in the K-band emission. Moreover, our data indicate that this object is surrounded by a large circumnuclear stellar disk and it is also located at the rotation center of the large molecular gas disk of NGC 253. Furthermore, a kinematic residual appears in the H2 rotation curve with a sinusoidal shape consistent with an outflow centered in the candidate nucleus position. The maximum outflow velocity is located about 14 pc from TH7, which is consistent with the radius of a shell detected around the nucleus candidate, observed at 18.3 μm (Qa) and 12.8 μm ([Ne ii]) with T-ReCS. Also, the Brγ emission line profile shows a pronounced blueshift and this emission line also has the highest equivalent width at this

  2. Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application

    NASA Astrophysics Data System (ADS)

    Weigel, R.; Hermann, M.; Curtius, J.; Voigt, C.; Walter, S.; Böttger, T.; Lepukhov, B.; Belyaev, G.; Borrmann, S.

    2009-06-01

    A characterization of the ultra-fine aerosol particle counter COPAS (COndensation PArticle counting System) for operation on board the Russian high altitude research aircraft M-55 Geophysika is presented. The COPAS instrument consists of an aerosol inlet and two dual-channel continuous flow Condensation Particle Counters (CPCs) operated with the chlorofluorocarbon FC-43. It operates at pressures between 400 and 50 hPa for aerosol detection in the particle diameter (dp) range from 6 nm up to 1 μm. The aerosol inlet, designed for the M-55, is characterized with respect to aspiration, transmission, and transport losses. The experimental characterization of counting efficiencies of three CPCs yields dp50 (50% detection particle diameter) of 6 nm, 11 nm, and 15 nm at temperature differences (ΔT) between saturator and condenser of 17°C, 30°C, and 33°C, respectively. Non-volatile particles are quantified with a fourth CPC, with dp50=11 nm. It includes an aerosol heating line (250°C) to evaporate H2SO4-H2O particles of 11 nm

  3. Counter-terrorism threat prediction architecture

    NASA Astrophysics Data System (ADS)

    Lehman, Lynn A.; Krause, Lee S.

    2004-09-01

    This paper will evaluate the feasibility of constructing a system to support intelligence analysts engaged in counter-terrorism. It will discuss the use of emerging techniques to evaluate a large-scale threat data repository (or Infosphere) and comparing analyst developed models to identify and discover potential threat-related activity with a uncertainty metric used to evaluate the threat. This system will also employ the use of psychological (or intent) modeling to incorporate combatant (i.e. terrorist) beliefs and intent. The paper will explore the feasibility of constructing a hetero-hierarchical (a hierarchy of more than one kind or type characterized by loose connection/feedback among elements of the hierarchy) agent based framework or "family of agents" to support "evidence retrieval" defined as combing, or searching the threat data repository and returning information with an uncertainty metric. The counter-terrorism threat prediction architecture will be guided by a series of models, constructed to represent threat operational objectives, potential targets, or terrorist objectives. The approach would compare model representations against information retrieved by the agent family to isolate or identify patterns that match within reasonable measures of proximity. The central areas of discussion will be the construction of an agent framework to search the available threat related information repository, evaluation of results against models that will represent the cultural foundations, mindset, sociology and emotional drive of typical threat combatants (i.e. the mind and objectives of a terrorist), and the development of evaluation techniques to compare result sets with the models representing threat behavior and threat targets. The applicability of concepts surrounding Modeling Field Theory (MFT) will be discussed as the basis of this research into development of proximity measures between the models and result sets and to provide feedback in support of model

  4. Counter-Rotating Tandem Motor Drilling System

    SciTech Connect

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger than

  5. 12. ANGLED VIEW OF THE SCOTT FURNACE WITH PRIMARY CONDENSER ...

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

    12. ANGLED VIEW OF THE SCOTT FURNACE WITH PRIMARY CONDENSER AND SOUTH SECONDARY CONDENSER IN BACKGROUND, LOOKING SOUTHWEST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  6. Dropwise condensation dynamics in humid air

    NASA Astrophysics Data System (ADS)

    Castillo Chacon, Julian Eduardo

    Dropwise condensation of atmospheric water vapor is important in multiple practical engineering applications. The roles of environmental factors and surface morphology/chemistry on the condensation dynamics need to be better understood to enable efficient water-harvesting, dehumidication, and other psychrometric processes. Systems and surfaces that promote faster condensation rates and self-shedding of condensate droplets could lead to improved mass transfer rates and higher water yields in harvesting applications. The thesis presents the design and construction of an experimental facility that allows visualization of the condensation process as a function of relative humidity. Dropwise condensation experiments are performed on a vertically oriented, hydrophobic surface at a controlled relative humidity and surface subcooling temperature. The distribution and growth of water droplets are monitored across the surface at different relative humidities (45%, 50%, 55%, and 70%) at a constant surface subcooling temperature of 15 °C below the ambient temperature. The droplet growth dynamics exhibits a strong dependency on relative humidity in the early stages during which there is a large population of small droplets on the surface and single droplet growth dominates over coalescence effects. At later stages, the dynamics of droplet growth is insensitive to relative humidity due to the dominance of coalescence effects. The overall volumetric rate of condensation on the surface is also assessed as a function of time and ambient relative humidity. Low relative humidity conditions not only slow the absolute rate of condensation, but also prolong an initial transient regime over which the condensation rate remains significantly below the steady-state value. The current state-of-the-art in dropwise condensation research indicates the need for systematic experimental investigations as a function of relative humidity. The improved understanding of the relative humidity

  7. Vortices and turbulence in trapped atomic condensates

    PubMed Central

    White, Angela C.; Anderson, Brian P.; Bagnato, Vanderlei S.

    2014-01-01

    After more than a decade of experiments generating and studying the physics of quantized vortices in atomic gas Bose–Einstein condensates, research is beginning to focus on the roles of vortices in quantum turbulence, as well as other measures of quantum turbulence in atomic condensates. Such research directions have the potential to uncover new insights into quantum turbulence, vortices, and superfluidity and also explore the similarities and differences between quantum and classical turbulence in entirely new settings. Here we present a critical assessment of theoretical and experimental studies in this emerging field of quantum turbulence in atomic condensates. PMID:24704880

  8. Heterogeneous Vapor Condensation in Boundary Layers

    SciTech Connect

    Bonilla, L. L.; Carpio, A.; Neu, J. C.

    2008-09-01

    We consider heterogeneous condensation of vapors mixed with a carrier gas in stagnation point boundary layer flow near a cold wall in the presence of solid particles much larger than the mean free path of vapor particles. The supersaturated vapor condenses on the particles by diffusion, particles and droplets are thermophoretically attracted to the wall. We sketch three asymptotic theories of the condensation process, calculate the flow-induced shift in the dew point interface, vapor density profile and deposition rates at the wall, and compare them to direct numerical simulation.

  9. Microscopic theory of equilibrium polariton condensates

    NASA Astrophysics Data System (ADS)

    Xue, Fei; Wu, Fengcheng; Xie, Ming; Su, Jung-Jung; MacDonald, A. H.

    2016-12-01

    We present a microscopic theory of the equilibrium polariton condensate state of a semiconductor quantum well in a planar optical cavity. The theory accounts for the adjustment of matter excitations to the presence of a coherent photon field, predicts effective polariton-polariton interaction strengths that are weaker and condensate exciton fractions that are smaller than in the commonly employed exciton-photon model, and yields effective Rabi coupling strengths that depend on the detuning of the cavity-photon energy relative to the bare exciton energy. The dressed quasiparticle bands that appear naturally in the theory provide a mechanism for electrical manipulation of polariton condensates.

  10. Counter-Punishment, Communication, and Cooperation among Partners.

    PubMed

    Andrighetto, Giulia; Brandts, Jordi; Conte, Rosaria; Sabater-Mir, Jordi; Solaz, Hector; Székely, Áron; Villatoro, Daniel

    2016-01-01

    We study how communication affects cooperation in an experimental public goods environment with punishment and counter-punishment opportunities. Participants interacted over 30 rounds in fixed groups with fixed identifiers that allowed them to trace other group members' behavior over time. The two dimensions of communication we study are asking for a specific contribution level and having to express oneself when choosing to counter-punish. We conduct four experimental treatments, all involving a contribution stage, a punishment stage, and a counter-punishment stage in each round. In the first treatment communication is not possible at any of the stages. The second treatment allows participants to ask for a contribution level at the punishment stage and in the third treatment participants are required to send a message if they decide to counter-punish. The fourth combines the two communication channels of the second and third treatments. We find that the three treatments involving communication at any of the two relevant stages lead to significantly higher contributions than the baseline treatment. We find no difference between the three treatments with communication. We also relate our results to previous results from treatments without counter-punishment opportunities and do not find that the presence of counter-punishment leads to lower cooperation level. The overall pattern of results shows that given fixed identifiers the key factor is the presence of communication. Whenever communication is possible contributions and earnings are higher than when it is not, regardless of counter-punishment opportunities.

  11. Counter-Punishment, Communication, and Cooperation among Partners

    PubMed Central

    Andrighetto, Giulia; Brandts, Jordi; Conte, Rosaria; Sabater-Mir, Jordi; Solaz, Hector; Székely, Áron; Villatoro, Daniel

    2016-01-01

    We study how communication affects cooperation in an experimental public goods environment with punishment and counter-punishment opportunities. Participants interacted over 30 rounds in fixed groups with fixed identifiers that allowed them to trace other group members' behavior over time. The two dimensions of communication we study are asking for a specific contribution level and having to express oneself when choosing to counter-punish. We conduct four experimental treatments, all involving a contribution stage, a punishment stage, and a counter-punishment stage in each round. In the first treatment communication is not possible at any of the stages. The second treatment allows participants to ask for a contribution level at the punishment stage and in the third treatment participants are required to send a message if they decide to counter-punish. The fourth combines the two communication channels of the second and third treatments. We find that the three treatments involving communication at any of the two relevant stages lead to significantly higher contributions than the baseline treatment. We find no difference between the three treatments with communication. We also relate our results to previous results from treatments without counter-punishment opportunities and do not find that the presence of counter-punishment leads to lower cooperation level. The overall pattern of results shows that given fixed identifiers the key factor is the presence of communication. Whenever communication is possible contributions and earnings are higher than when it is not, regardless of counter-punishment opportunities. PMID:27092065

  12. High-resolution imaging studies of the near-nucleus regions of comets

    NASA Astrophysics Data System (ADS)

    Goldberg, B. A.; Slavin, J. A.; Halliday, I.; McIntosh, B. A.; Aikman, G. C. L.; Cook, A. F.

    1986-12-01

    High-resolution, calibrated images of the near-nucleus regions of Halley, Giacobini-Zinner (for ICE encounter) and additional comets displaying widely differing levels of activity were acquired with a CCD sensor at the Cassegrain focus of the 3.6 m Canada-France-Hawaii Telescope (CFHT). The International Halley Watch designated interference filters were used. Successful correlation of ICE magnetic field data with the optical images obtained with the CFHT on the night of encounter (11 Sept. 1985) primarily through the H2O(+) and neighboring continuum passbands and with 300 km spatial resolution provokes reinterpretation of the observed structure of cometary ion tails. The observations of Halley, limited by bad weather, were made at significant periods of the apparition: the first, in December 1984 with the comet at 5.3 AU during the period of the onset of activity; and the last, in November 1985 with the comet near opposition. The December observations show evidence of residual activity. The 18 November data show a highly-condensed inner coma with an extreme falloff in brightness from the region of the nucleus. These data provide the basis for characterizing the gas and dust environment in the immediate vicinity of the active nucleus.

  13. Over-the-Counter Medications in Pregnancy.

    PubMed

    Servey, Jessica; Chang, Jennifer

    2014-10-15

    Many pregnant women take over-the-counter (OTC) medications despite the absence of randomized controlled trials to guide their use during pregnancy. Most data come from case-control and cohort studies. In 1979, the U.S. Food and Drug Administration began reviewing all prescription and OTC medications to develop risk categories for use in pregnancy. Most OTC medications taken during pregnancy are for allergy, respiratory, gastrointestinal, or skin conditions, as well as for general analgesia. Acetaminophen, which is used by about 65% of pregnant women, is generally considered safe during any trimester. Cold medications are also commonly used and are considered safe for short-term use outside of the first trimester. Many gastrointestinal medications are now available OTC. Histamine H2 blockers and proton pump inhibitors have not demonstrated significant fetal effects. Nonsteroidal anti-inflammatory drugs are generally not recommended in pregnancy, especially during organogenesis and in the third trimester. There are even fewer data regarding use of individual herbal supplements. Ginger is considered safe and effective for treating nausea in pregnancy. Topical creams are considered safe based on small studies and previous practice. All OTC medication use should be discussed with patients, and the effects of the symptoms should be balanced with the risks and benefits of each medication. Because of the expanding OTC market, formalized studies are warranted for patients to make a safe and informed decision about OTC medication use during pregnancy.

  14. Training options for countering nuclear smuggling

    SciTech Connect

    Ball, D Y; Erickson, S A

    1999-07-01

    The burden of stopping a nuclear smuggling attempt at the border rests most heavily on the front-line customs inspector. He needs to know how to use the technological tools at his disposal, how to discern tell-tale anomalies in export documents and manifests, how to notice psychological signs of a smuggler's tension, and how to search anything that might hide nuclear material. This means that assistance in the counter-nuclear smuggling training of customs officers is one of the most critical areas of help that the United States can provide. This paper discusses the various modes of specialized training, both in the field and in courses, as well as the types of assistance that can be provided. Training for nuclear customs specialists, and supervisors and managers of nuclear smuggling detection systems is also important, and differs from front-line inspector training in several aspects. The limitations of training and technological tools such as expert centers that will overcome these limitations are also discussed. Training assistance planned by DOE/NN-43 to Russia within the Second Line of Defense program is discussed in the light of these options, and future possibilities for such training are projected.

  15. Countering GPS jamming and EW threat

    NASA Astrophysics Data System (ADS)

    Pereira, Carlos M.; Rastegar, J.; McLain, Clifford E.; Alanson, T.; McMullan, Charles; Nguyen, H.-L.

    2007-09-01

    Efforts at the U.S. Army Research, Development and Engineering Center (ARDEC) at Picatinny, New Jersey are focused on developing methods to counter GPS jamming and electronic warfare (EW) threat by eliminating GPS dependency entirely. In addition, the need for munitions cost reduction requires alternatives to expensive high-grade inertia components. Efforts at ARDEC include investigations of novel methods for onboard measurement of munitions full position and angular orientation independent of GPS signals or high-grade inertia components. Currently, two types of direct angular measurement sensors are being investigated. A first sensor, Radio Frequency Polarized Sensor (RFPS), uses an electromagnetic field as a reference. A second sensor is based on magnetometers, using the Earth magnetic field for orientation measurement. Magnetometers, however, can only provide two independent orientation measurements. The RFPS may also be used to make full object position and angular orientation measurement relative to a reference coordinate system, which may be moving or stationary. The potential applications of novel RFPS sensors is in providing highly effective inexpensive replacement for GPS, which could be used in a "Layered Navigation" scheme employing alternate referencing methods and reduce the current dependency on GPS as a primary reference for guided gun-fired munitions. Other potential applications of RFPSs is in UAVs, UGVs, and robotic platforms.

  16. Fermi-motion effect on the intermediate energy nucleus-nucleus collision

    NASA Astrophysics Data System (ADS)

    Fan, G. W.; Kong, W. Y.; Han, T. F.; Li, X. C.; Ma, J. B.; Sheng, Z. Q.; Shi, G. Z.; Tian, F.; Wang, J.; Zhang, C.

    2016-11-01

    The Glauber model is modified with the Fermi-motion effect in the calculation of elastic differential cross-sections and momentum distributions of a fragment from mother nucleus. Different reaction systems at low energies are calculated with the modified Glauber model. It is found that calculations including the Fermi-motion provide a better prescription relating the model to a proper nuclear density distribution by comparing with the experimental data. On the basis of the studies, the influence of the correction on the extracted nuclear radius is quantified. The results further confirm the importance of the Fermi-motion in the nucleus-nucleus collision reactions at low energies.

  17. Hardware support for collecting performance counters directly to memory

    DOEpatents

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

    2012-09-25

    Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

  18. Condensed Matter Theories: Volume 25

    NASA Astrophysics Data System (ADS)

    Ludeña, Eduardo V.; Bishop, Raymond F.; Iza, Peter

    2011-03-01

    dynamics and density functional theory. Exchange-correlation functionals from the identical-particle Ornstein-Zernike equation: Basic formulation and numerical algorithms / R. Cuevas-Saavedra and P. W. Ayers. Features and catalytic properties of RhCu: A review / S. Gonzalez, C. Sousa and F. Illas. Kinetic energy functionals: Exact ones from analytic model wave functions and approximate ones in orbital-free molecular dynamics / V. V. Karasiev ... [et al.]. Numerical analysis of hydrogen storage in carbon nanopores / C. Wexler ... [et al.] -- pt. F. Superconductivity. Generalized Bose-Einstein condensation in superconductivity / M. de Llano. Kohn anomaly energy in conventional superconductors equals twice the energy of the superconducting gap: How and why? / R. Chaudhury and M. P. Das. Collective excitations in superconductors and semiconductors in the presence of a condensed phase / Z. Koinov. Thermal expansion of ferromagnetic superconductors: Possible application to UGe[symbol] / N. Hatayama and R. Konno. Generalized superconducting gap in a Boson-Fermion model / T. A. Mamedov and M. de Llano. Influence of domain walls in the superconductor/ferromagnet proximity effect / E. J. Patino. Spin singlet and triplet superconductivity induced by correlated hopping interactions / L. A. Perez, J. S. Millan and C. Wang -- pt. G. Statistical mechanics, relativistic quantum mechanics. Boltzmann's ergodic hypothesis: A meeting place for two cultures / M. H. Lee. Electron-electron interaction in the non-relativistic limit / F. B. Malik.

  19. The Checkerboard Model of the Nucleus

    NASA Astrophysics Data System (ADS)

    Lach, Theodore

    2015-04-01

    The Checker Board Model (CBM) of the nucleus and the associated extended standard model predicts that nature has 5 generations of quarks not 3 and that Nucleus is 2 dimensional. The CBM theory began with an insight into the structure of the He nucleus around the year 1989. Details of how this theory evolved which took many years, and is found on my web site (http://checkerboard.dnsalias.net) or in the following references One independent check of this model is that the wavelength of the ``up'' quark orbiting inside the proton at 84.8123% the speed of light (around the ``dn'' quark in the center of the proton) turns out to be exactly one de Broglie wavelength something determined after the mass and speed of the up quark were determined by other means. This theory explains the mass of the proton and neutron and their magnetic moments and this along with the beautiful symmetric 2D structure of the He nucleus led to the evolution of this theory. When this theory was first presented at Argonne in 1996, it was the first time that anyone had predicted the quarks orbited inside the proton at relativistic speeds and it was met with skepticism.

  20. New developments in nucleus pulposus replacement technology.

    PubMed

    Carl, Allen; Ledet, Eric; Yuan, Hansen; Sharan, Alok

    2004-01-01

    Attempts to alleviate the pain attributed to degeneration of the nucleus pulposus using replacement or reinforcement techniques dating back to the 1950s are reviewed. The various materials and their insertion techniques are discussed as are results available from early clinical experiences. These techniques are in evolution and clinical outcomes will be necessary to establish the efficacy of these approaches.

  1. Nucleus-associated actin in Amoeba proteus.

    PubMed

    Berdieva, Mariia; Bogolyubov, Dmitry; Podlipaeva, Yuliya; Goodkov, Andrew

    2016-10-01

    The presence, spatial distribution and forms of intranuclear and nucleus-associated cytoplasmic actin were studied in Amoeba proteus with immunocytochemical approaches. Labeling with different anti-actin antibodies and staining with TRITC-phalloidin and fluorescent deoxyribonuclease I were used. We showed that actin is abundant within the nucleus as well as in the cytoplasm of A. proteus cells. According to DNase I experiments, the predominant form of intranuclear actin is G-actin which is associated with chromatin strands. Besides, unpolymerized actin was shown to participate in organization of a prominent actin layer adjacent to the outer surface of nuclear envelope. No significant amount of F-actin was found in the nucleus. At the same time, the amoeba nucleus is enclosed in a basket-like structure formed by circumnuclear actin filaments and bundles connected with global cytoplasmic actin cytoskeleton. A supposed architectural function of actin filaments was studied by treatment with actin-depolymerizing agent latrunculin A. It disassembled the circumnuclear actin system, but did not affect the intranuclear chromatin structure. The results obtained for amoeba cells support the modern concept that actin is involved in fundamental nuclear processes that have evolved in the cells of multicellular organisms.

  2. Nucleon-nucleus interactions from JACEE

    NASA Technical Reports Server (NTRS)

    Burnett, T. H.; Dake, S.; Fuki, M.; Gregory, J. C.; Hayashi, T.; Holynski, R.; Iwai, J.; Jones, W. V.; Jurak, A.; Lord, J. J.

    1985-01-01

    Results on hadron-nucleus interactions from the Japanese-American Cooperation Emulsion Experiment experiment are presented. Angular distributions for charged particles, and angular and transverse momentum spectra for photons have been measured for a sample of events with sigma epsilon sub gamma. Results on central rapidity density and transverse energy flow are discussed.

  3. The condensation of water on adsorbed viruses.

    PubMed

    Alonso, José María; Tatti, Francesco; Chuvilin, Andrey; Mam, Keriya; Ondarçuhu, Thierry; Bittner, Alexander M

    2013-11-26

    The wetting and dewetting behavior of biological nanostructures and to a greater degree single molecules is not well-known even though their contact with water is the basis for all biology. Here, we show that environmental electron microscopy (EM) can be applied as a means of imaging the condensation of water onto viruses. We captured the formation of submicrometer water droplets and filaments on single viral particles by environmental EM and by environmental transmission EM. The condensate structures are compatible with capillary condensation between adsorbed virus particles and with known droplet shapes on patterned surfaces. Our results confirm that such droplets exist down to <50 nm. The viruses preserved their shape after a condensation/evaporation cycle as expected from their stability in air and water. Moreover we developed procedures that overcome problems of beam damage and of resolving structures with a low atomic number.

  4. Nonlinear interactions in an organic polariton condensate.

    PubMed

    Daskalakis, K S; Maier, S A; Murray, R; Kéna-Cohen, S

    2014-03-01

    Under the right conditions, cavity polaritons form a macroscopic condensate in the ground state. The fascinating nonlinear behaviour of this condensate is largely dictated by the strength of polariton-polariton interactions. In inorganic semiconductors, these result principally from the Coulomb interaction between Wannier-Mott excitons. Such interactions are considerably weaker for the tightly bound Frenkel excitons characteristic of organic semiconductors and were notably absent in the first reported demonstration of organic polariton lasing. In this work, we demonstrate the realization of an organic polariton condensate, at room temperature, in a microcavity containing a thin film of 2,7-bis[9,9-di(4-methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl)fluorene. On reaching threshold, we observe the spontaneous formation of a linearly polarized condensate, which exhibits a superlinear power dependence, long-range order and a power-dependent blueshift: a clear signature of Frenkel polariton interactions.

  5. Scanning Tunneling Microscopy Observation of Phonon Condensate.

    PubMed

    Altfeder, Igor; Voevodin, Andrey A; Check, Michael H; Eichfeld, Sarah M; Robinson, Joshua A; Balatsky, Alexander V

    2017-02-22

    Using quantum tunneling of electrons into vibrating surface atoms, phonon oscillations can be observed on the atomic scale. Phonon interference patterns with unusually large signal amplitudes have been revealed by scanning tunneling microscopy in intercalated van der Waals heterostructures. Our results show that the effective radius of these phonon quasi-bound states, the real-space distribution of phonon standing wave amplitudes, the scattering phase shifts, and the nonlinear intermode coupling strongly depend on the presence of defect-induced scattering resonance. The observed coherence of these quasi-bound states most likely arises from phase- and frequency-synchronized dynamics of all phonon modes, and indicates the formation of many-body condensate of optical phonons around resonant defects. We found that increasing the strength of the scattering resonance causes the increase of the condensate droplet radius without affecting the condensate fraction inside it. The condensate can be observed at room temperature.

  6. Condenser design for AMTEC power conversion

    NASA Technical Reports Server (NTRS)

    Crowley, Christopher J.

    1991-01-01

    The condenser and the electrodes are the two elements of an alkali metal thermal-to-electric conversion (AMTEC) cell which most greatly affect the energy conversion performance. A condenser is described which accomplishes two critical functions in an AMTEC cell: management of the fluid under microgravity conditions and optimization of conversion efficiency. The first function is achieved via the use of a controlled surface shape, along with drainage grooves and arteries to collect the fluid. Capillary forces manage the fluid in microgravity and dominate hydrostatic effects on the ground so the device is ground-testable. The second function is achieved via a smooth film of highly reflective liquid sodium on the condensing surface, resulting in minimization of parasitic heat losses due to radiation heat transfer. Power conversion efficiencies of 25 percent to 30 percent are estimated with this condenser using present technology for the electrodes.

  7. Ferromagnetic properties of charged vector boson condensate

    SciTech Connect

    Dolgov, Alexander D.; Lepidi, Angela; Piccinelli, Gabriella E-mail: lepidi@fe.infn.it

    2010-08-01

    Bose-Einstein condensation of W bosons in the early universe is studied. It is shown that, in the broken phase of the standard electroweak theory, the condensed W bosons form a ferromagnetic state with aligned spins. In this case the primeval plasma may be spontaneously magnetized inside macroscopically large domains and form magnetic fields which may be the seeds for the observed today galactic and intergalactic fields. However, in a modified theory, e.g. in a theory with stronger quartic self interactions of gauge bosons e.g. due to a smaller value of the weak mixing angle, antiferromagnetic condensation is possible. In the latter case W bosons form scalar condensate with macroscopically large electric charge density i.e. with a large average value of the bilinear product of W-vector fields but with microscopically small average value of the field itself.

  8. Kaon condensation in dense stellar matter

    SciTech Connect

    Lee, Chang-Hwan; Rho, M. |

    1995-03-01

    This article combines two talks given by the authors and is based on Works done in collaboration with G.E. Brown and D.P. Min on kaon condensation in dense baryonic medium treated in chiral perturbation theory using heavy-baryon formalism. It contains, in addition to what was recently published, astrophysical backgrounds for kaon condensation discussed by Brown and Bethe, a discussion on a renormalization-group analysis to meson condensation worked out together with H.K. Lee and S.J. Sin, and the recent results of K.M. Westerberg in the bound-state approach to the Skyrme model. Negatively charged kaons are predicted to condense at a critical density 2 {approx_lt} {rho}/{rho}o {approx_lt} 4, in the range to allow the intriguing new phenomena predicted by Brown and Bethe to take place in compact star matter.

  9. Ghost Condensation in N=1 Supergravity

    NASA Astrophysics Data System (ADS)

    Koehn, Michael; Lehners, Jean-Luc; Ovrut, Burt

    We present the theory of an N=1 supersymmetric ghost condensate coupled to supergravity using a general formalism for constructing locally supersymmetric higher-derivative chiral superfield actions. The theory admits a ghost condensate vacuum in de Sitter spacetime. Expanded around this vacuum, the scalar sector is shown to be ghost-free with no spatial gradient instabilities. The fermion sector is found to consist of a massless chiral fermion and a massless gravitino. The ghost condensate vacuum spontaneously breaks local supersymmetry with the chiral field as the Goldstone fermion. Although potentially able to get a mass through the super-Higgs effect, the vanishing superpotential in the ghost condensate theory renders the gravitino massless.

  10. Condensation and Hydrolysis - An Optical Problem?

    ERIC Educational Resources Information Center

    Kellett, N. C.; Johnstone, A. H.

    1974-01-01

    Recent surveys have shown that pupils find the topics of esterification and condensation difficult. Reasons for the difficulty are not clear. Described is research designed to determine where the difficulties were visual or conceptual in origin. (RH)

  11. Scanning Tunneling Microscopy Observation of Phonon Condensate

    PubMed Central

    Altfeder, Igor; Voevodin, Andrey A.; Check, Michael H.; Eichfeld, Sarah M.; Robinson, Joshua A.; Balatsky, Alexander V.

    2017-01-01

    Using quantum tunneling of electrons into vibrating surface atoms, phonon oscillations can be observed on the atomic scale. Phonon interference patterns with unusually large signal amplitudes have been revealed by scanning tunneling microscopy in intercalated van der Waals heterostructures. Our results show that the effective radius of these phonon quasi-bound states, the real-space distribution of phonon standing wave amplitudes, the scattering phase shifts, and the nonlinear intermode coupling strongly depend on the presence of defect-induced scattering resonance. The observed coherence of these quasi-bound states most likely arises from phase- and frequency-synchronized dynamics of all phonon modes, and indicates the formation of many-body condensate of optical phonons around resonant defects. We found that increasing the strength of the scattering resonance causes the increase of the condensate droplet radius without affecting the condensate fraction inside it. The condensate can be observed at room temperature. PMID:28225066

  12. Condensed-matter trio scoop Dirac prize

    NASA Astrophysics Data System (ADS)

    Durrani, Matin

    2012-09-01

    Three condensed-matter physicists, who have advanced our understanding of a strange type of material known as a "topological insulator", have won this year's Dirac medal from the International Centre for Theoretical Physics (ICTP) in Trieste, Italy.

  13. Recent developments in Bose-Einstein condensation

    SciTech Connect

    Kalman, G.

    1997-09-22

    This paper contains viewgraphs on developments on Bose-Einstein condensation. Some topics covered are: strongly coupled coulomb systems; standard response functions of the first and second kind; dynamical mean field theory; quasi localized charge approximation; and the main equations.

  14. Passive control of unsteady condensation shock wave

    NASA Astrophysics Data System (ADS)

    Setoguchi, Toshiaki; Matsuo, Shigeru; Shimamoto, Katsumi; Yasugi, Shinichi; Yu, Shen

    2000-12-01

    A rapid expansion of moist air or steam in a supersonic nozzle gives rise to nonequilibrium condensation phenomena. Thereby, if the heat released by condensation of water vapour exceeds a certain quantity, the flow will become unstable and periodic flow oscillations of the unsteady condensation shock wave will occur. For the passive control of shock-boundary layer interaction using the porous wall with a plenum underneath, many papers have been presented on the application of the technique to transonic airfoil flows. In this paper, the passive technique is applied to three types of oscillations of the unsteady condensation shock wave generated in a supersonic nozzle in order to suppress the unsteady behavior. As a result, the effects of number of slits and length of cavity on the aspect of flow field have been clarified numerically using a 3rd-order MUSCL type TVD finite-difference scheme with a second-order fractional-step for time integration.

  15. Condensation Front Migration in a Protoplanetary Nebula

    NASA Technical Reports Server (NTRS)

    Davis, Sanford S.

    2004-01-01

    Condensation front dynamics are investigated in the mid-solar nebula region. A quasi-steady model of the evolving nebula is combined with equilibrium vapor pressure curves to determine evolutionary condensation fronts for selected species. These fronts are found to migrate inwards from the far-nebula to final positions during a period of 10(exp 7) years. The physical process governing this movement is a combination of local viscous heating and luminescent heating from the central star. Two luminescent heating models are used and their effects on the ultimate radial position of the condensation front are discussed. At first the fronts move much faster than the nebular accretion velocity, but after a time the accreting gas and dust overtakes the slowing condensation front.

  16. Molecular equilibrium with condensation. [in astrophysics

    NASA Technical Reports Server (NTRS)

    Sharp, C. M.; Huebner, W. F.

    1990-01-01

    Minimization of the Gibbs energy of formation for species of chemical elements and compounds in their gas and condensed phases determines their relative abundances in a mixture in chemical equilibrium. The procedure is more general and more powerful than previous abundance determinations in multiphase astrophysical mixtures. Some results for astrophysical equations of state are presented, and the effects of condensation on opacity are briefly indicated.

  17. Condensate polishers add operating reliability and flexibility

    SciTech Connect

    Layman, C.M.; Bennett, L.L.

    2008-08-15

    Many of today's advanced steam generators favour either an all-volatile treatment or oxygenated treatment chemistry programme, both of which require strict maintenance of an ultra-pure boiler fedwater ro condensate system. Those requirements are many times at odds with the lower-quality water sources, such as greywater, available for plant makeup and cooling water. Adding a condensate polisher can be a simple, cost-effective solution. 4 figs.

  18. Dynamic simulation recalls condensate piping event

    SciTech Connect

    Farrell, R.J.; Reneberg, K.O. ); Moy, H.C. )

    1994-05-01

    This article describes how experience gained from simulating and reconstructing a condensate piping event will be used by Consolidated Edison to analyze control system problems. A cooperative effort by Con Edison and the Chemical Engineering Department at Polytechnic University used modular modeling system to investigate the probable cause of a Con Edison condensate piping event. Con Edison commissioned the work to serve as a case study for the more general problem of control systems analysis using dynamic simulation and MMS.

  19. Enhancement of Condensation on a Vertical Plate

    NASA Astrophysics Data System (ADS)

    Chu, Rencai; Hatanaka, Tsutomu; Nishio, Shigefumi

    In previous study, the characteristic of the condensation heat transfer on the dispersed vertical surface were investigated experimentally for the application of the finned surface to the thermoelectric generator utilizing boiling and condensation as the electrodes of the thermoelectric module. A prediction model for this diapered finned surface was proposed, based on Adamek-Webb model of the condensation on a finned tube. In this study, a condensation heat transfer experiment on a vertical dispersed finned surfaces using FC5312 was carried out, in order to enhance the condensation heat transfer coefficient by optimizing the fin size on a dispersed heat transfer surface. The object of the experiment was limited to the rectangular fin with the height of 3 mm. Experimental parameters were the temperature difference, the fin groove width, the fin thickness and the dispersing size on the vertical direction. As the results, it was found from the experiment that the dependence of the condensation heat transfer coefficient on the dispersed size is controlled by the fin groove width. That is, the condensation heat transfer coefficient will increase for a smaller fin groove width and will decrease for a larger fin groove width, with decreasing of the dispersing size. Moreover, there is an optimum fin thickness at which the condensation heat transfer coefficient becomes the maximum in the case of constant fin groove width for both size of the fin groove width. This effect of the fin thickness is more significant for the smaller fin groove width. Further, the prediction values exhibit a good agreement with the experimental data in the present experiment.

  20. Dual condensates at finite isospin chemical potential

    NASA Astrophysics Data System (ADS)

    Zhang, Zhao; Miao, Qing

    2016-02-01

    The dual observables as order parameters for center symmetry are tested at finite isospin chemical potential μI in a Polyakov-loop enhanced chiral model of QCD with physical quark masses. As a counterpart of the dressed Polyakov-loop, the first Fourier moment of pion condensate is introduced for μI >mπ / 2 under the temporal twisted boundary conditions for quarks. We demonstrate that this dual condensate exhibits the similar temperature dependence as the conventional Polyakov-loop. We confirm that its rapid increase with T is driven by the evaporating of pion condensation. On the other hand, the dressed Polyakov-loop shows abnormal thermal behavior, which even decreases with T at low temperatures due to the influence of pion condensate. We also find that the dressed Polyakov-loop always rises most steeply at the chiral transition temperature, which is consistent with the previous results in Nambu-Jona-Lasinio (NJL) model and its variants without considering the center symmetry. Since both quantities are strongly affected by the chiral symmetry and pion condensation, we conclude that it is difficult to clarify the deconfinement transition from the dual condensates in this situation within this model.

  1. Interstitial Condensation Risk at Thermal Rehabilitated Buildings

    NASA Astrophysics Data System (ADS)

    Baran, I.; Bliuc, I.; Iacob, A.; Dumitrescu, L.; Pescaru, R. A.; Helepciuc, C.

    2016-11-01

    The increasing thermal insulation degree of existing residential buildings, aiming to reduce the energy requirements for ensuring the indoor comfort, has as expected effect the elimination of condensation risk. However, in some cases this phenomenon occurs, both on the inner surface of the closing element and also in its structure. The surface condensation causes can be identified and can be easily removed. Instead, the causes and even the presence of interstitial condensation are more difficult to be observed. But the moistening of the insulation materials and the reduction of thermal insulation capacity or even its total degradation, contravene into a large extent or totally to the main purpose of the additional thermal protection. To avoid such situations, it is necessary to respect some principles concerning the structure, resulted from the knowledge of the water vapour diffusion behaviour of various materials. It is known that condensation vulnerability is higher for the additional thermal protection solutions by disposing the insulating material on the inside surface of the closing element. But practice has shown that the condensation phenomenon is not totally excluded neither in the case of outside thermal insulation - which is the current solution applied to the rehabilitation works - if the principles mentioned above are not known and respected. In this paper two models are compared on which the risk of interstitial condensation can be checked. The analysis made on two structures of exterior walls with thermal insulation demonstrates the need for additional verifications before proposing a solution for thermal rehabilitation of the envelope elements.

  2. Numerical simulation of condensation on structured surfaces.

    PubMed

    Fu, Xiaowu; Yao, Zhaohui; Hao, Pengfei

    2014-11-25

    Condensation of liquid droplets on solid surfaces happens widely in nature and industrial processes. This phase-change phenomenon has great effect on the performance of some microfluidic devices. On the basis of micro- and nanotechnology, superhydrophobic structured surfaces can be well-fabricated. In this work, the nucleating and growth of droplets on different structured surfaces are investigated numerically. The dynamic behavior of droplets during the condensation is simulated by the multiphase lattice Boltzmann method (LBM), which has the ability to incorporate the microscopic interactions, including fluid-fluid interaction and fluid-surface interaction. The results by the LBM show that, besides the chemical properties of surfaces, the topography of structures on solid surfaces influences the condensation process. For superhydrophobic surfaces, the spacing and height of microridges have significant influence on the nucleation sites. This mechanism provides an effective way for prevention of wetting on surfaces in engineering applications. Moreover, it suggests a way to prevent ice formation on surfaces caused by the condensation of subcooled water. For hydrophilic surfaces, however, microstructures may be submerged by the liquid films adhering to the surfaces. In this case, microstructures will fail to control the condensation process. Our research provides an optimized way for designing surfaces for condensation in engineering systems.

  3. Condensation of the air-steam mixture in a vertical tube condenser

    NASA Astrophysics Data System (ADS)

    Havlík, Jan; Dlouhý, Tomáš

    2016-03-01

    This paper deals with the condensation of water vapour in the presence of non-condensable air. Experimental and theoretical solutions of this problem are presented here. A heat exchanger for the condensation of industrial waste steam containing infiltrated air was designed. The condenser consists of a bundle of vertical tubes in which the steam condenses as it flows downwards with cooling water flowing outside the tubes in the opposite direction. Experiments with pure steam and with mixtures of steam with added air were carried out to find the dependence of the condensation heat transfer coefficient (HTC) on the air concentration in the steam mixture. The experimental results were compared with the theoretical formulas describing the cases. The theoretical determination of the HTC is based on the Nusselt model of steam condensation on a vertical wall, where the analogy of heat and mass transfer is used to take into account the behaviour of air in a steam mixture during the condensation process. The resulting dependencies obtained from the experiments and obtained from the theoretical model have similar results. The significant decrease in the condensation HTC, which begins at very low air concentrations in a steam mixture, was confirmed.

  4. Implementation of non-condensable gases condensation suppression model into the WCOBRA/TRAC-TF2 LOCA safety evaluation code

    SciTech Connect

    Liao, J.; Cao, L.; Ohkawa, K.; Frepoli, C.

    2012-07-01

    The non-condensable gases condensation suppression model is important for a realistic LOCA safety analysis code. A condensation suppression model for direct contact condensation was previously developed by Westinghouse using first principles. The model is believed to be an accurate description of the direct contact condensation process in the presence of non-condensable gases. The Westinghouse condensation suppression model is further revised by applying a more physical model. The revised condensation suppression model is thus implemented into the WCOBRA/TRAC-TF2 LOCA safety evaluation code for both 3-D module (COBRA-TF) and 1-D module (TRAC-PF1). Parametric study using the revised Westinghouse condensation suppression model is conducted. Additionally, the performance of non-condensable gases condensation suppression model is examined in the ACHILLES (ISP-25) separate effects test and LOFT L2-5 (ISP-13) integral effects test. (authors)

  5. 16. INTERIOR OF KITCHEN SHOWING UPDATED CABINETS AND COUNTER TOP, ...

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

    16. INTERIOR OF KITCHEN SHOWING UPDATED CABINETS AND COUNTER TOP, AND ORIGINAL WOOD-FRAMED SLIDING GLASS WINDOW IN NORTH WALL OVERLOOKING FRONT ENTRY. VIEW TO NORTHEAST. - Rush Creek Hydroelectric System, Worker Cottage, Rush Creek, June Lake, Mono County, CA

  6. Test-Aerosol Generator For Calibrating Particle Counters

    NASA Technical Reports Server (NTRS)

    Mogan, Paul A.; Adams, Alois J.; Schwindt, Christian J.; Hodge, Timothy R.; Mallow, Tim J.; Duong, Anh A.; Bukauskas, Vyto V.

    1996-01-01

    Apparatus generates clean, stable aerosol stream for use in testing and calibrating laser-based aerosol-particle counter. Size and concentration of aerosol particles controlled to ensure accurate calibration. Cheap, widely available medical nebulizers used to generate aerosols.

  7. INTERIOR OF THE WORKSHOP, LOOKING SOUTH. (On the counter of ...

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

    INTERIOR OF THE WORKSHOP, LOOKING SOUTH. (On the counter of the workshop are instructions and supplies for artificially inseminating pigs.) - Jenne Farm, Workshop, 538 Engle Road, Coupeville, Island County, WA

  8. Multianode cylindrical proportional counter for high count rates

    DOEpatents

    Hanson, J.A.; Kopp, M.K.

    1980-05-23

    A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (< 60 keV) at count rates of greater than 10/sup 5/ counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

  9. Multianode cylindrical proportional counter for high count rates

    DOEpatents

    Hanson, James A.; Kopp, Manfred K.

    1981-01-01

    A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (<60 keV) at count rates of greater than 10.sup.5 counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

  10. Average transverse momentum and energy density in high-energy nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Burnett, T. H.; Dake, S.; Fuki, M.; Gregory, J. C.; Hayashi, T.; Holynski, R.; Iwai, J.; Jones, W. V.; Jurak, A.; Lord, J. J.

    1986-01-01

    Emulsion chambers were used to measure the transverse momenta of photons or pi(0) mesons produced in high-energy cosmic-ray nucleus-nucleus collisions. A group of events having large average transverse momenta has been found which apparently exceeds the expected limiting values. Analysis of the events at early interaction times, of the order of 1 fm/c, indicates that the observed transverse momentum increases with both rapidity density and energy density.

  11. Condensation and Evaporation of Solar System Materials

    NASA Astrophysics Data System (ADS)

    Davis, A. M.; Richter, F. M.

    2003-12-01

    It is widely believed that the materials making up the solar system were derived from a nebular gas and dust cloud that went through an early high-temperature stage during which virtually all of the material was in the gas phase. At one time, it was thought that the entire inner solar nebula was hot, but it is now believed that most material was processed through regions where high temperatures were achieved. Certainly some material, such as presolar grains (cf., Mendybaev et al., 2002a), has never been exposed to high temperatures. As the system cooled, solids and perhaps liquids began to condense, but at some point the partially condensed materials became isolated from the remaining gas. Various lines of evidence support this view. At the largest scale, there is the observation that the Earth, Moon, Mars, and all chondritic meteorites except for the CI chondrites are depleted to varying degrees in the abundances of moderately volatile elements relative to bulk solar system composition. The CI chondrites reflect the bulk composition of the solar system for all but hydrogen, carbon, nitrogen, oxygen, and the rare gases, the most volatile elements (see Chapter 1.03; Palme et al., 1988; McDonough and Sun, 1995; Humayun and Cassen, 2000). The depletions in moderately volatile elements are, to a significant degree, correlated with condensation temperature, suggesting progressive removal of gas as condensation proceeded ( Cassen, 1996). Additional observations that can be explained by partial condensation are that various particularly primitive components of meteorites (e.g., calcium-, aluminum-rich refractory inclusions, and certain metal grains) have mineralogy and/or details of their chemical composition that are remarkably similar to what is calculated for equilibrium condensates from a solar composition gas. For example, the calcium-, aluminum-rich inclusions (CAIs) in chondritic meteorites have compositions very similar to that calculated for the first 5% of total

  12. Bathroom Buddies: Countering your Clockwise Rotation

    NASA Astrophysics Data System (ADS)

    Cooper, C. M.; Stegman, D. R.

    2006-12-01

    Which way does your bathtub, toilet, sink, or other favorite plumbing basin drain? Popular television shows perpetuate the fact that water spins the opposite direction in the southern hemisphere, and sometimes even explicitly point to the Coriolis effect (or Earth's rotation) as the cause. Skeptics disagree: "No way. Water doesn't obey your rules: it goes where it wants...like me, babe." [1]. Fact: Cyclones rotate clockwise in the southern hemisphere and hurricanes counter-clockwise in the northern hemisphere. But does your hemisphere also determine the direction water spirals down your toilet? In the ideal scenario of water draining out a sink (i.e. a defect-free, perfectly-leveled basin in which water has remained undisturbed for sufficient enough time to quiet any background motions or eddies) --- then yes, maybe it is possible. However, in everyday life, not even the most decadent of bathtubs provide us a large enough lengthscale to observe the Coriolis effect on the direction which water spirals towards the drain. Thus, we are left confronting the possibility that something heard on television isn't true. But is just "telling" students, friends, or strangers in bars enough to debunk this urban myth? Rather, we offer a practical demonstration involving a friend from the opposite hemisphere (if not one in existence, then find one on the internet!), a bathroom, a funnel, a bucket, some food coloring, a camera, a pitcher and some equations and scalings for extra credit and fun. 1) Simpson, B., "Bart vs. Australia", Season 6, Episode 119, 1995.

  13. Introduction to Neutron Coincidence Counter Design Based on Boron-10

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-01-22

    The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

  14. A Gas Proportional Scintillation Counter with krypton filling

    NASA Astrophysics Data System (ADS)

    Monteiro, C. M. B.; Mano, R. D. P.; Barata, E. C. G. M.; Fernandes, L. M. P.; Freitas, E. D. C.

    2016-12-01

    A Gas Proportional Scintillation Counter filled with pure krypton was studied. Energy resolution below 10% for 5.9-keV X-rays was obtained with this prototype. This value is much better than the energy resolution obtained with proportional counters or other MPGDs with krypton filling. The krypton electroluminescence scintillation and ionisation thresholds were found to be about 0.5 and 3.5 kV cm-1bar-1, respectively.

  15. Over-the-counter treatments for acne and rosacea.

    PubMed

    Rosamilia, Lorraine Larsen

    2016-06-01

    Acne and rosacea are common inflammatory processes historically classified in the same disease category, but evolving understanding of their disparate pathophysiology and exacerbating factors have generated an enormous armamentarium of therapeutic possibilities. Patients seek over-the-counter therapies first when managing cutaneous disease; therefore, this review defines ingredients considered to be effective over-the-counter acne and rosacea products, their mechanisms, and safe formulations, including botanical components, oral supplements, and other anecdotal options in this vast skin care domain.

  16. Liberty and Order: Reintegration as Counter-Insurgency in Colombia

    DTIC Science & Technology

    2003-01-01

    experienced the same fits and starts as others in the region. There have been successes , including the reintegration of the M-19 (Movimiento del 19... REINTEGRATION AS COUNTER-INSURGENCY IN COLOMBIA Mr. GREGORY E. PHILLIPS, DOS COURSE 5601 and 5602 FUNDAMENTALS OF STRATEGIC LOGIC and THE NATURE OF...COVERED 00-00-2003 to 00-00-2003 4. TITLE AND SUBTITLE Liberty and Order: Reintegration as Counter-Insurgency in Colombia 5a. CONTRACT NUMBER 5b

  17. Systems Approach to Terrorism: Countering the Terrorist Training Subsystem

    DTIC Science & Technology

    2006-12-01

    TERRORISM : COUNTERING THE TERRORIST TRAINING SUBSYSTEM by Erdogan Celebi December 2006 Thesis Advisor: Nancy Roberts Second Reader...REPORT DATE December 2006 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE: Systems Approach to Terrorism : Countering the...distribution is unlimited 12b. DISTRIBUTION CODE A 13. ABSTRACT This study on terrorism training follows the logic that terrorism is a

  18. Electromagnetically Induced Guiding of Counter-propagating Lasers in Plasmas

    SciTech Connect

    First Author = G. Shvets; A. Pukhov

    1998-05-01

    The interaction of counter-propagating laser pulses in a plasma is considered. When the frequencies of the two lasers are close, nonlinear modification of the refraction index results in the mutual focusing of the two beams. A short (of order the plasma period) laser pulse can also be nonlinearly focused by a long counter-propagating beam which extends over the entire guiding length. This phenomenon of electromagnetically induced guiding can be utilized in laser-driven plasma accelerators.

  19. Using DMA for copying performance counter data to memory

    DOEpatents

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W

    2013-12-31

    A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance data.

  20. Evaluation of dual flow counter-current chromatography and intermittent counter-current extraction.

    PubMed

    Ignatova, Svetlana; Hewitson, Peter; Mathews, Ben; Sutherland, Ian

    2011-09-09

    The aim of this research is to compare two continuous extraction technologies, intermittent counter-current extraction (ICcE) and dual flow counter-current chromatography (DFCCC), in terms of loading and throughput using the GUESSmix, and show the advantages and disadvantages of the two methods. A model sample containing caffeine, vanillin, naringenin and carvone, with a total load of 11.2 g, was employed with a hexane-ethyl acetate-methanol-water (2:3:2:3) phase system to evaluate an ICcE method on a preparative (912 ml coil volume) DE-Midi instrument. While DFCCC was carried out on a specially designed preparative (561 ml coil volume) bobbin installed in a similar Midi instrument case. While similar throughputs of 7.8 g/h and 6.9 g/h were achieved for the ICcE and DFCCC methods respectively, ICcE was demonstrated to have a number of advantages over DFCCC.

  1. SAIC SENTINEL acoustic counter-sniper system

    NASA Astrophysics Data System (ADS)

    Stoughton, Roland B.

    1997-02-01

    An acoustic surveillance system tailored to the detection and location of sniper fire was designed and a prototype built and tested. The SENTINEL system by Science Applications International Corporation exploits 100 kHz 16- bit digitization of signals from 16 condenser microphones in two volumetric arrays to make robust determinations of bearing, range, bullet trajectory, weapon caliber, and muzzle velocity. Signal processing is accomplished on VME hardware with C40 DSPs. Solutions are displayed within three seconds of a detected event on a ruggedized full-daylight- readable color laptop console. Typical accuracies are 1 degree to 2 degrees in azimuth and 2% to 10% in range, depending on range and environmental conditions. The large bandwidth and dynamic range, and exploitation of shock waveform period and amplitude estimates, give the system good capability even in difficult geometries and highly reverberant environments. In-depth study of the phenomenology of the ballistic shock wave was undertaken during the design phase. Results of this study are summarized.

  2. The Neutrophil Nucleus and Its Role in Neutrophilic Function.

    PubMed

    Carvalho, Leonardo Olivieri; Aquino, Elaine Nascimento; Neves, Anne Caroline Dias; Fontes, Wagner

    2015-09-01

    The cell nucleus plays a key role in differentiation processes in eukaryotic cells. It is not the nucleus in particular, but the organization of the genes and their remodeling that provides the data for the adjustments to be made according to the medium. The neutrophil nucleus has a different morphology. It is a multi-lobed nucleus where some researchers argue no longer function. However, studies indicate that it is very probable the occurrence of chromatin remodeling during activation steps. It may be that the human neutrophil nucleus also contributes to the mobility of neutrophils through thin tissue spaces. Questions like these will be discussed in this small review. The topics include morphology of human neutrophil nucleus, maturation process and modifications of the neutrophil nucleus, neutrophil activation and chromatin modifications, causes and consequences of multi-lobulated segmented morphology, and importance of the nucleus in the formation of neutrophil extracellular traps (NETs).

  3. 46 CFR 56.50-35 - Condensate pumps.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Condensate pumps. 56.50-35 Section 56.50-35 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-35 Condensate pumps. Two means shall be provided for discharging the condensate from the main condenser, one of which shall be...

  4. 46 CFR 56.50-35 - Condensate pumps.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Condensate pumps. 56.50-35 Section 56.50-35 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-35 Condensate pumps. Two means shall be provided for discharging the condensate from the main condenser, one of which shall be...

  5. 46 CFR 56.50-35 - Condensate pumps.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Condensate pumps. 56.50-35 Section 56.50-35 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-35 Condensate pumps. Two means shall be provided for discharging the condensate from the main condenser, one of which shall be...

  6. 46 CFR 56.50-35 - Condensate pumps.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Condensate pumps. 56.50-35 Section 56.50-35 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-35 Condensate pumps. Two means shall be provided for discharging the condensate from the main condenser, one of which shall be...

  7. 46 CFR 56.50-35 - Condensate pumps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Condensate pumps. 56.50-35 Section 56.50-35 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-35 Condensate pumps. Two means shall be provided for discharging the condensate from the main condenser, one of which shall be...

  8. Infinite statistics condensate as a model of dark matter

    SciTech Connect

    Ebadi, Zahra; Mirza, Behrouz; Mohammadzadeh, Hosein E-mail: b.mirza@cc.iut.ac.ir

    2013-11-01

    In some models, dark matter is considered as a condensate bosonic system. In this paper, we prove that condensation is also possible for particles that obey infinite statistics and derive the critical condensation temperature. We argue that a condensed state of a gas of very weakly interacting particles obeying infinite statistics could be considered as a consistent model of dark matter.

  9. Advertising health: the case for counter-ads.

    PubMed Central

    Dorfman, L; Wallack, L

    1993-01-01

    Public service advertisements have been used by many in hopes of "selling" good health behaviors. But selling good behavior--even if it could be done more effectively--is not the best goal for using mass media to prevent health problems. Personal behavior is only part of what determines health status. Social conditions and the physical environment are important determinants of health that are usually ignored by health promotion advertising. Public service advertising may be doing more harm than good if it is diverting attention from more effective socially based health promotion strategies. Counter-ads are one communications strategy that could be used to promote a broader responsibility for rectifying health problems. In the tradition of advocacy advertising directly promoting policy rather than products, counter-ads promote views consistent with a public health perspective. Counter-ads set the agenda for health issues, conferring status on policy-oriented strategies for addressing health problems. The primary purpose of counter-ads is to challenge the dominant view that public health problems reflect personal health habits. They are controversial because they place health issues in a social and political context. Advertising strategies for health promotion range over a spectrum from individually oriented public service advertising to socially oriented counter-advertising. The recent anti-tobacco campaign from the California Department of Health Services represents advertisements across the spectrum. Counter-ads that focus on a politically controversial definition for health problems are an appropriate and necessary alternative to public service advertising. PMID:8265756

  10. A high resolution Timing Counter for the MEG II experiment

    NASA Astrophysics Data System (ADS)

    De Gerone, M.; Bevilacqua, A.; Biasotti, M.; Boca, G.; Cattaneo, P. W.; Gatti, F.; Nishimura, M.; Ootani, W.; Pizzigoni, G.; Rossella, M.; Shibata, N.; Siccardi, F.; Simonetta, M.; Uchiyama, Y.; Yoshida, K.

    2016-07-01

    The development of a Timing Counter detector designed for the MEGII upgrade of the MEG experiment, which strives to improve the sensitivity on the μ+ →e+ γ decay of an order of magnitude, is presented. It is based on two sets of counters (sectors) arranged on a semi-cylindrical structure; each sector consists of 256 counters. Each counter consists of tile of fast scintillator with a dual-side read-out based on SiPM arrays in series connection. The high granularity has two advantages: optimized size for achieving high resolution (75 ps) for the single counter, and a signal e+ crosses several counters, so that resolution improves by averaging multiple time measurements. A prototype has been built and tested both in BTF and PSI facilities in order to prove the multi-hit scheme in MEG-like beam conditions. A 35 ps resolution with eight hits has been obtained with a e+ beam at 100 kHz. The first sector will be tested in the MEG II pre-engineering run planned at the end of 2015.

  11. Advertising health: the case for counter-ads.

    PubMed

    Dorfman, L; Wallack, L

    1993-01-01

    Public service advertisements have been used by many in hopes of "selling" good health behaviors. But selling good behavior--even if it could be done more effectively--is not the best goal for using mass media to prevent health problems. Personal behavior is only part of what determines health status. Social conditions and the physical environment are important determinants of health that are usually ignored by health promotion advertising. Public service advertising may be doing more harm than good if it is diverting attention from more effective socially based health promotion strategies. Counter-ads are one communications strategy that could be used to promote a broader responsibility for rectifying health problems. In the tradition of advocacy advertising directly promoting policy rather than products, counter-ads promote views consistent with a public health perspective. Counter-ads set the agenda for health issues, conferring status on policy-oriented strategies for addressing health problems. The primary purpose of counter-ads is to challenge the dominant view that public health problems reflect personal health habits. They are controversial because they place health issues in a social and political context. Advertising strategies for health promotion range over a spectrum from individually oriented public service advertising to socially oriented counter-advertising. The recent anti-tobacco campaign from the California Department of Health Services represents advertisements across the spectrum. Counter-ads that focus on a politically controversial definition for health problems are an appropriate and necessary alternative to public service advertising.

  12. Message passing with a limited number of DMA byte counters

    DOEpatents

    Blocksome, Michael; Chen, Dong; Giampapa, Mark E.; Heidelberger, Philip; Kumar, Sameer; Parker, Jeffrey J.

    2011-10-04

    A method for passing messages in a parallel computer system constructed as a plurality of compute nodes interconnected as a network where each compute node includes a DMA engine but includes only a limited number of byte counters for tracking a number of bytes that are sent or received by the DMA engine, where the byte counters may be used in shared counter or exclusive counter modes of operation. The method includes using rendezvous protocol, a source compute node deterministically sending a request to send (RTS) message with a single RTS descriptor using an exclusive injection counter to track both the RTS message and message data to be sent in association with the RTS message, to a destination compute node such that the RTS descriptor indicates to the destination compute node that the message data will be adaptively routed to the destination node. Using one DMA FIFO at the source compute node, the RTS descriptors are maintained for rendezvous messages destined for the destination compute node to ensure proper message data ordering thereat. Using a reception counter at a DMA engine, the destination compute node tracks reception of the RTS and associated message data and sends a clear to send (CTS) message to the source node in a rendezvous protocol form of a remote get to accept the RTS message and message data and processing the remote get (CTS) by the source compute node DMA engine to provide the message data to be sent.

  13. Why do we have a caudate nucleus?

    PubMed

    Villablanca, Jaime R

    2010-01-01

    In order to understand the physiological role of the caudate nucleus, we combine here our laboratory data on cats with reports of patients with selective damage to this nucleus. Cats with bilateral removal of the caudate nuclei showed a stereotyped behavior consisting of persistently approaching and then following a person, another cat, or any object, and attempting to contact the target. Simultaneously, the animals exhibited a friendly disposition and persistent docility together with purring and forelimbs treading/kneading. The magnitude and duration of this behavior was proportional to the extent of the removal reaching a maximum after ablations of 65% or more of the caudate tissue. These cats were hyperactive but they had lost the feline elegance of movements. Additional features of acaudate cats were: (1) postural and accuracy deficits (plus perseveration) in paw usage tasks including bar pressing for food reward; (2) cognitive and perceptual impairments on a T-maze battery of tasks and on the bar pressing tasks; (3) blockage or blunting of the species-specific behavioral response to a single injection of morphine; Unilateral caudate nucleus removal did not produce global behavioral effects, but only deficit in the contralateral paw contact placing reaction and paw usage/bar pressing. Moreover and surprisingly, we found hypertrophy of the ipsilateral caudate nucleus following prenatal focal neocortical removal. The findings in human were also behavioral (not neurological) and also occurred with unilateral caudate damage. The main manifestations consisted of loss of drive (apathy), obsessive-compulsive behavior, cognitive deficits, stimulus-bound perseverative behavior, and hyperactivity. Based on all of the above data we propose that the specific function of the caudate nucleus is to control approach-attachment behavior, ranging from plain approach to a target, to romantic love. This putative function would account well for the caudate involvement in the

  14. Collateral projections from the lateral parabrachial nucleus to the paraventricular thalamic nucleus and the central amygdaloid nucleus in the rat.

    PubMed

    Liang, Shao-Hua; Yin, Jun-Bin; Sun, Yi; Bai, Yang; Zhou, Kai-Xiang; Zhao, Wen-Jun; Wang, Wei; Dong, Yu-Lin; Li, Yun-Qing

    2016-08-26

    Combined the retrograde double tracing with immunofluorescence histochemical staining, we examined the neurons in the lateral parabrachial nucleus (LPB) sent collateral projections to the paraventricular thalamic nucleus (PVT) and central amygdaloid nucleus (CeA) and their roles in the nociceptive transmission in the rat. After the injection of Fluoro-gold (FG) into the PVT and tetramethylrhodamine-dextran (TMR) into the CeA, respectively, FG/TMR double-labeled neurons were observed in the LPB. The percentages of FG/TMR double-labeled neurons to the total number of FG- or TMR-labeled neurons were 6.18% and 9.09%, respectively. Almost all of the FG/TMR double-labeled neurons (95%) exhibited calcitonin gene-related peptide (CGRP) immunoreactivity. In the condition of neuropathic pain, 94% of these neurons showed FOS immunoreactivity. The present data indicates that some of CGRP-expressing neurons in the LPB may transmit nociceptive information toward the PVT and CeA by way of axon collaterals.

  15. Enhanced tubes for steam condensers. Volume 1, Summary of condensation and fouling; Volume 2, Detailed study of steam condensation

    SciTech Connect

    Webb, R.L.; Chamra, L.; Jaber, H.

    1992-02-01

    Electric utility steam condensers typically use plain tubes made of titanium, stainless steel, or copper alloys. Approximately two-thirds of the total thermal resistance is on the water side of the plain tube. This program seeks to conceive and develop a tube geometry that has special enhancement geometries on the tube (water) side and the steam (shell) side. This ``enhanced`` tube geometry, will provide increased heat transfer coefficients. The enhanced tubes will allow the steam to condense at a lower temperature. The reduced condensing temperature will reduce the turbine heat rate, and increase the plant peak load capability. Water side fouling and fouling control is a very important consideration affecting the choice of the tube side enhancement. Hence, we have consciously considered fouling potential in our selection of the tube side surface geometry. Using appropriate correlations and theoretical models, we have designed condensation and water side surface geometries that will provide high performance and be cleanable using sponge ball cleaning. Commercial tube manufacturers have made the required tube geometries for test purposes. The heat transfer test program includes measurement of the condensation and water side heat transfer coefficients. Fouling tests are being run to measure the waterside fouling resistance, and to the test the ability of the sponge ball cleaning system to clean the tubes.

  16. Sandwich-type Au-PEI/DNA/PEI-Dexa nanocomplex for nucleus-targeted gene delivery in vitro and in vivo.

    PubMed

    Chen, Zhenzhen; Zhang, Lifen; He, Yuling; Li, Yanfeng

    2014-08-27

    Many synthetic Au-based cationic nanoparticles (AuNPs) for nonviral gene delivery show high efficiency in vitro, but their excessive charge density, harsh reducing conditions, and nontarget delivery prevent their application in vivo. Herein, we constructed a sandwich-type layered polyethylenimine (PEI)-coated gold nanocomposite outerlaid with a nucleus-targeted Dexamethasone (Dexa), namely, Au-PEI/DNA/PEI-Dexa nanocomplex, for DNA delivery system using a low molecular weight PEI as a mild reducing agent. The nucleus-targeting Au-PEI/DNA/PEI-Dexa nanocomplex with low positive charge and low cytotoxicity condensed DNA and protected from enzymatic degradation. In vitro transfection studies demonstrated that Au-PEI/DNA/PEI-Dexa nanocomplex exhibited much more efficient nucleus transfection than Au-PEI/DNA/PEI without nucleus-targeted residues and commercially available PEI 25 kDa due to the Dexa targeting of the nucleus. Furthermore, the nanocomplex markedly transfected pTRAIL (TRAIL = tumor-necrosis-factor-related apoptosis-inducing ligand) to tumors in vivo and subsequently inhibited the tumor growth with minimal side effects. These findings suggest that nucleus-targeting Au-PEI/DNA/PEI-Dexa ternary complexes have promising potential in gene delivery.

  17. Nanoscopic structure of DNA condensed for gene delivery.

    PubMed Central

    Dunlap, D D; Maggi, A; Soria, M R; Monaco, L

    1997-01-01

    Scanning force microscopy was used to examine DNA condensates prepared with varying stoichiometries of lipospermine or polyethylenimine in physiological solution. For the first time, individual DNA strands were clearly visualized in incomplete condensates without drying. Using lipospermine at sub-saturating concentrations, discrete nuclei of condensation were observed often surrounded by folded loops of DNA. Similar packing of DNA loops occurred for polyethylenimine-induced condensation. Increasing the amount of the condensing agent led to the progressive coalescence or aggregation of initial condensation nuclei through folding rather than winding the DNA. At over-saturating charge ratios of the cationic lipid or polymer to DNA, condensates had sizes smaller than or equal to those measured previously in electron micrographs. Polyethylenimine condensates were more compact than lipospermine condensates and both produced more homogeneously compacted plasmids when used in a 2-4-fold charge excess. The size and morphology of the condensates may affect their efficiency in transfection. PMID:9224610

  18. Nucleus accumbens GLP-1 receptors influence meal size and palatability.

    PubMed

    Dossat, Amanda M; Diaz, Ryan; Gallo, Lindsay; Panagos, Alyssa; Kay, Kristen; Williams, Diana L

    2013-06-15

    Recent evidence suggests that the glucagon-like peptide-1 (GLP-1) neuronal projection to the nucleus accumbens core (NAcC) contributes to food intake control. To investigate the role of endogenous stimulation of GLP-1 receptors (GLP-1R) in NAcC, we examined the effects of the GLP-1R antagonist exendin-(9-39) (Ex9) on meal pattern and microstructure of ingestive behavior in rats. Intra-NAcC Ex9 treatment selectively increased meal size relative to vehicle in rats consuming 0.25 M sucrose solution or sweetened condensed milk. Microstructural analysis revealed effects of NAcC Ex9 on initial lick rate and the size and duration of licking bursts in rats consuming 0.1 or 0.25 M sucrose, suggesting that blockade of NAcC GLP-1R increases palatability. Because NAcC Ex9 did not affect licking for nonnutritive saccharin (0.1%), we suggest that the presence of nutrients in the gut may be required for endogenous stimulation of NAcC GLP-1R. Consistent with this, we also found that the meal size-suppressive effects of intragastric nutrient infusion were attenuated by NAcC delivery of Ex9 at a dose that had no effect when delivered alone. Analysis of licking patterns revealed that NAcC Ex9 did not reverse intragastric nutrient-induced suppression of burst number but rather blunted the effect of nutrient infusion on meal size primarily by increasing the size and duration of licking bursts. Together, our results suggest that NAcC Ex9 influences taste evaluation. We conclude that GLP-1 released in NAcC in response to gastrointestinal nutrients reduces the hedonic value of food.

  19. Cell Nucleus-Targeting Zwitterionic Carbon Dots

    PubMed Central

    Jung, Yun Kyung; Shin, Eeseul; Kim, Byeong-Su

    2015-01-01

    An innovative nucleus-targeting zwitterionic carbon dot (CD) vehicle has been developed for anticancer drug delivery and optical monitoring. The zwitterionic functional groups of the CDs introduced by a simple one-step synthesis using β-alanine as a passivating and zwitterionic ligand allow cytoplasmic uptake and subsequent nuclear translocation of the CDs. Moreover, multicolor fluorescence improves the accuracy of the CDs as an optical code. The CD-based drug delivery system constructed by non-covalent grafting of doxorubicin, exhibits superior antitumor efficacy owing to enhanced nuclear delivery in vitro and tumor accumulation in vivo, resulting in highly effective tumor growth inhibition. Since the zwitterionic CDs are highly biocompatible and effectively translocated into the nucleus, it provides a compelling solution to a multifunctional nanoparticle for substantially enhanced nuclear uptake of drugs and optical monitoring of translocation. PMID:26689549

  20. Gustatory Reward and the Nucleus Accumbens

    PubMed Central

    Norgren, R.; Hajnal, A.; Mungarndee, S.S.

    2011-01-01

    The concept of reward is central to psychology, but remains a cipher for neuroscience. Considerable evidence implicates dopamine in the process of reward and much of the data derives from the nucleus accumbens. Gustatory stimuli are widely used for animal studies of reward, but the connections between the taste and reward systems are unknown. In a series of experiments, our laboratory has addressed this issue using functional neurochemistry and neuroanatomy. First, using microdialysis probes, we demonstrated that sapid sucrose releases dopamine in the nucleus accumbens. The effect is dependent on oral stimulation and concentration. We subsequently determined that this response was independent of the thalamocortical gustatory system, but substantially blunted by damage to the parabrachial limbic taste projection. Further experiments using c-fos histochemistry confirmed that the limbic pathway was the prime carrier for the gustatory afferent activity that drives accumbens dopamine release. PMID:16822531

  1. Cell Nucleus-Targeting Zwitterionic Carbon Dots.

    PubMed

    Jung, Yun Kyung; Shin, Eeseul; Kim, Byeong-Su

    2015-12-22

    An innovative nucleus-targeting zwitterionic carbon dot (CD) vehicle has been developed for anticancer drug delivery and optical monitoring. The zwitterionic functional groups of the CDs introduced by a simple one-step synthesis using β-alanine as a passivating and zwitterionic ligand allow cytoplasmic uptake and subsequent nuclear translocation of the CDs. Moreover, multicolor fluorescence improves the accuracy of the CDs as an optical code. The CD-based drug delivery system constructed by non-covalent grafting of doxorubicin, exhibits superior antitumor efficacy owing to enhanced nuclear delivery in vitro and tumor accumulation in vivo, resulting in highly effective tumor growth inhibition. Since the zwitterionic CDs are highly biocompatible and effectively translocated into the nucleus, it provides a compelling solution to a multifunctional nanoparticle for substantially enhanced nuclear uptake of drugs and optical monitoring of translocation.

  2. Core-nucleus distortation in hypernuclei

    SciTech Connect

    Bodmer, A.R.; Usmani, Q.N.

    1995-08-01

    We are completing a study of the effects of the spherical distortion of the {open_quotes}core{close_quotes} nucleus by the {Lambda} in a hypernucleus. The response of the core was determined by an appropriately chosen energy-density functional which depends, in particular, on the nuclear compressibility. The forcing action of the A is determined by the nuclear density dependence of the {Lambda} binding in nuclear matter which is obtained from our work on the {Lambda} single-particle energies. Because of the strongly repulsive {Lambda}NN forces, this {Lambda} binding {open_quotes}saturates{close_quotes} at a density close to the central density of nuclei, and results in a reduced core-nucleus distortion much less than would otherwise be obtained. The effects of the core distortion then turn out to be very small even for quite light hypernuclei. This result justifies the assumption that spherical core nuclei are effectively undistorted in a hypernucleus.

  3. Finite nucleus effects on relativistic energy corrections

    NASA Technical Reports Server (NTRS)

    Dyall, Kenneth G.; Faegri, Knut, Jr.

    1993-01-01

    The effect of using a finite nucleus model in quantum-chemical calculations is examined. Relativistic corrections from the first order Foldy-Wouthuysen terms are affected indirectly by the change in wavefunction, but also directly as a result of revised expressions for the Darwin and spin-orbit terms due to the change in nuclear potential. A calculation for the Rn atom indicates that the mass-velocity and Darwin corrections are much more sensitive to the finite nucleus than the non-relativistic total energy, but that the total contribution for these two terms is quite stable provided the revised form of the Darwin term is used. The spin-orbit interaction is not greatly affected by the choice of nuclear model.

  4. GENOTOXICITY OF TEN CIGARETTE SMOKE CONDENSATES IN FOUR TEST SYSTEMS: COMPARISONS BETWEEN ASSAYS AND CONDENSATES

    EPA Science Inventory

    What is the study?
    This the first assessment of a set of cigarette smoke condensates from a range of cigarette types in a variety (4) of short-term genotoxicity assays.
    Why was it done?
    No such comparative study of cigarette smoke condensates has been reported. H...

  5. Physical Properties of Cometary Nucleus Candidates

    NASA Technical Reports Server (NTRS)

    Jewitt, David; Hillman, John (Technical Monitor)

    2003-01-01

    In this proposal we aim to study the physical properties of the Centaurs and the dead comets, these being the precursors to, and the remnants from, the active cometary nuclei. The nuclei themselves are very difficult to study, because of the contaminating effects of near-nucleus coma. Systematic investigation of the nuclei both before they enter the zone of strong sublimation and after they have depleted their near-surface volatiles should neatly bracket the properties of these objects, revealing evolutionary effects.

  6. Pygmy dipole response in 238U nucleus

    NASA Astrophysics Data System (ADS)

    Guliyev, Ekber; Kuliev, Ali Akbar; Quliyev, Huseynqulu

    2017-02-01

    The presence of the El pygmy dipole resonance (PDR) in the actinide nucleus 238U was shown via QRPA. Below the particle threshold energy, 24 excitation states were calculated. The calculations, is demonstrating the presence of a PDR with evidence for K splitting. The calculations further suggest that the PDR in 238U is predominantly K=0. The obtained results show universality of the PDR in atomic nuclei.

  7. Absolute cross sections of compound nucleus reactions

    NASA Astrophysics Data System (ADS)

    Capurro, O. A.

    1993-11-01

    The program SEEF is a Fortran IV computer code for the extraction of absolute cross sections of compound nucleus reactions. When the evaporation residue is fed by its parents, only cumulative cross sections will be obtained from off-line gamma ray measurements. But, if one has the parent excitation function (experimental or calculated), this code will make it possible to determine absolute cross sections of any exit channel.

  8. How to build a yeast nucleus.

    PubMed

    Wong, Hua; Arbona, Jean-Michel; Zimmer, Christophe

    2013-01-01

    Biological functions including gene expression and DNA repair are affected by the 3D architecture of the genome, but the underlying mechanisms are still unknown. Notably, it remains unclear to what extent nuclear architecture is driven by generic physical properties of polymers or by specific factors such as proteins binding particular DNA sequences. The budding yeast nucleus has been intensely studied by imaging and biochemical techniques, resulting in a large quantitative data set on locus positions and DNA contact frequencies. We recently described a quantitative model of the interphase yeast nucleus in which chromosomes are represented as passively moving polymer chains. This model ignores the DNA sequence information except for specific constraints at the centromeres, telomeres, and the ribosomal DNA (rDNA). Despite its simplicity, the model accounts for a large majority of experimental data, including absolute and relative locus positions and contact frequency patterns at chromosomal and subchromosomal scales. Here, we also illustrate the model's ability to reproduce observed features of chromatin movements. Our results strongly suggest that the dynamic large-scale architecture of the yeast nucleus is dominated by statistical properties of randomly moving polymers with a few sequence-specific constraints, rather than by a large number of DNA-specific factors or epigenetic modifications. In addition, we show that our model accounts for recently measured variations in homologous recombination efficiency, illustrating its potential for quantitatively understanding functional consequences of nuclear architecture.

  9. Comet nucleus and asteroid sample return missions

    NASA Astrophysics Data System (ADS)

    1992-06-01

    Three Advanced Design Projects have been completed this academic year at Penn State. At the beginning of the fall semester the students were organized into eight groups and given their choice of either a comet nucleus or an asteroid sample return mission. Once a mission had been chosen, the students developed conceptual designs. These were evaluated at the end of the fall semester and combined into three separate mission plans, including a comet nucleus same return (CNSR), a single asteroid sample return (SASR), and a multiple asteroid sample return (MASR). To facilitate the work required for each mission, the class was reorganized in the spring semester by combining groups to form three mission teams. An integration team consisting of two members from each group was formed for each mission so that communication and information exchange would be easier among the groups. The types of projects designed by the students evolved from numerous discussions with Penn State faculty and mission planners at the Johnson Space Center Human/Robotic Spacecraft Office. Robotic sample return missions are widely considered valuable precursors to manned missions in that they can provide details about a site's environment and scientific value. For example, a sample return from an asteroid might reveal valuable resources that, once mined, could be utilized for propulsion. These missions are also more adaptable when considering the risk to humans visiting unknown and potentially dangerous locations, such as a comet nucleus.

  10. Theoretical predictions for the nucleus 296118

    NASA Astrophysics Data System (ADS)

    Sobiczewski, A.

    2016-11-01

    Theoretical predictions for the α -decay chain of the nucleus 296118 are performed. The synthesis of this nucleus is being attempted in experiments running in Dubna. The α -decay energies Qα, and the α -decay and spontaneous-fission half-lives, Tα and Tsf, are studied. The analysis of the α decay is based on a phenomenological model using only three parameters. The calculations are performed in nine variants using masses obtained within nine nuclear-mass models describing masses of the heaviest nuclei. The experimental Qα energies, known from earlier experiments for the potential daughter, 292Lv, and grand-daughter, 288Fl, nuclei are reproduced with an average of the absolute values of the discrepancies: from 0.13 to 1.52 MeV within the considered variants. Measured half-lives Tα are reconstructed within average ratios: from 1.7 to 1054. Within all variants considered, the half-life Tα of the nucleus 296118 is obtained larger than needed (around 1 μ s ) for its observation.

  11. Comet nucleus and asteroid sample return missions

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Three Advanced Design Projects have been completed this academic year at Penn State. At the beginning of the fall semester the students were organized into eight groups and given their choice of either a comet nucleus or an asteroid sample return mission. Once a mission had been chosen, the students developed conceptual designs. These were evaluated at the end of the fall semester and combined into three separate mission plans, including a comet nucleus same return (CNSR), a single asteroid sample return (SASR), and a multiple asteroid sample return (MASR). To facilitate the work required for each mission, the class was reorganized in the spring semester by combining groups to form three mission teams. An integration team consisting of two members from each group was formed for each mission so that communication and information exchange would be easier among the groups. The types of projects designed by the students evolved from numerous discussions with Penn State faculty and mission planners at the Johnson Space Center Human/Robotic Spacecraft Office. Robotic sample return missions are widely considered valuable precursors to manned missions in that they can provide details about a site's environment and scientific value. For example, a sample return from an asteroid might reveal valuable resources that, once mined, could be utilized for propulsion. These missions are also more adaptable when considering the risk to humans visiting unknown and potentially dangerous locations, such as a comet nucleus.

  12. Structure of vacuum Cu–Ta condensates

    NASA Astrophysics Data System (ADS)

    Zubkov, A. I.; Zubarev, E. N.; Sobol', O. V.; Hlushchenko, M. A.; Lutsenko, E. V.

    2017-02-01

    The structure of vacuum condensate foils (separated from substrates) of the binary Cu-Ta system has been investigated both in the initial condensed state and after annealings at temperatures of up to 1000°C. It has been shown that the alloying of a vapor flow of the matrix metal (copper) with tantalum to 0.5 at % makes it possible to reduce the grain size from 3 μm to 50 nm. Depending on the tantalum concentration, condensates exhibit a broad spectrum of structural states, i.e., single- and two-phase, a supersaturated solution of tantalum in the fcc lattice of copper, etc. The structure of the objects possesses a high thermal stability. The temperature of the start of grain growth in the copper matrix depends on the tantalum content and can reach 900°C. The dispersion of the structure of copper condensates and its thermal stability is due to the formation of segregates of tantalum atoms at the boundaries of grains of the copper matrix both in the process of condensation and upon subsequent annealing.

  13. Laser Isotope Separation Employing Condensation Repression

    SciTech Connect

    Eerkens, Jeff W.; Miller, William H.

    2004-09-15

    Molecular laser isotope separation (MLIS) techniques using condensation repression (CR) harvesting are reviewed and compared with atomic vapor laser isotope separation (AVLIS), gaseous diffusion (DIF), ultracentrifuges (UCF), and electromagnetic separations (EMS). Two different CR-MLIS or CRISLA (Condensation Repression Isotope Separation by Laser Activation) approaches have been under investigation at the University of Missouri (MU), one involving supersonic super-cooled free jets and dimer formation, and the other subsonic cold-wall condensation. Both employ mixtures of an isotopomer (e.g. {sup i}QF{sub 6}) and a carrier gas, operated at low temperatures and pressures. Present theories of VT relaxation, dimerization, and condensation are found to be unsatisfactory to explain/predict experimental CRISLA results. They were replaced by fundamentally new models that allow ab-initio calculation of isotope enrichments and predictions of condensation parameters for laser-excited and non-excited vapors which are in good agreement with experiment. Because of supersonic speeds, throughputs for free-jet CRISLA are a thousand times higher than cold-wall CRISLA schemes, and thus preferred for large-quantity Uranium enrichments. For small-quantity separations of (radioactive) medical isotopes, the simpler coldwall CRISLA method may be adequate.

  14. Infrared applications for steam turbine condenser systems

    NASA Astrophysics Data System (ADS)

    Lanius, Mark A.

    2000-03-01

    Infrared inspection of the main steam condensers at the Peach Bottom Atomic Power Station has been utilized successfully in detecting condenser air in-leakage problems. Air in-leakage lowers the condenser's vacuum, thus decreasing the condenser's efficiency. This creates backpressure on the turbine which lowers its efficiency, resulting in fewer megawatts generated. Air in-leakage also creates an increase in off-gas flow which is a radiological concern for both the plant and the public. Inspections are normally performed on the condenser's manway covers and rupture disks prior to an outage during coast down and post outage. The optimum conditions are 100% power and temperature, however, a high radiation field prevents the inspection until reactor power is down to 65% or less. Anomalies are typically indicated by cooling in the effected areas of the air in-leakage. The anomalies are not limited to air in-leakage. Intermittent water out-leakage, due to a heater dump valve cycling, has been detected when visual inspections field nothing.

  15. Why double-stranded RNA resists condensation.

    PubMed

    Tolokh, Igor S; Pabit, Suzette A; Katz, Andrea M; Chen, Yujie; Drozdetski, Aleksander; Baker, Nathan; Pollack, Lois; Onufriev, Alexey V

    2014-01-01

    The addition of small amounts of multivalent cations to solutions containing double-stranded DNA leads to inter-DNA attraction and eventual condensation. Surprisingly, the condensation is suppressed in double-stranded RNA, which carries the same negative charge as DNA, but assumes a different double helical form. Here, we combine experiment and atomistic simulations to propose a mechanism that explains the variations in condensation of short (25 base-pairs) nucleic acid (NA) duplexes, from B-like form of homopolymeric DNA, to mixed sequence DNA, to DNA:RNA hybrid, to A-like RNA. Circular dichroism measurements suggest that duplex helical geometry is not the fundamental property that ultimately determines the observed differences in condensation. Instead, these differences are governed by the spatial variation of cobalt hexammine (CoHex) binding to NA. There are two major NA-CoHex binding modes--internal and external--distinguished by the proximity of bound CoHex to the helical axis. We find a significant difference, up to 5-fold, in the fraction of ions bound to the external surfaces of the different NA constructs studied. NA condensation propensity is determined by the fraction of CoHex ions in the external binding mode.

  16. The NSF Condensed Matter Physics Program

    NASA Astrophysics Data System (ADS)

    Sokol, Paul

    The Condensed Matter Physics (CMP) program in the NSF Division of Materials Research (DMR) supports experimental, as well as combined experiment and theory projects investigating the fundamental physics behind phenomena exhibited by condensed matter systems. CMP is the largest Individual Investigator Award program in DMR and supports a broad portfolio of research spanning both hard and soft condensed matter. Representative research areas include: 1) phenomena at the nano- to macro-scale including: transport, magnetic, and optical phenomena; classical and quantum phase transitions; localization; electronic, magnetic, and lattice structure or excitations; superconductivity; topological insulators; and nonlinear dynamics. 2) low-temperature physics: quantum fluids and solids; 1D & 2D electron systems. 3) soft condensed matter: partially ordered fluids, granular and colloid physics, liquid crystals, and 4) understanding the fundamental physics of new states of matter as well as the physical behavior of condensed matter under extreme conditions e.g., low temperatures, high pressures, and high magnetic fields. In this talk I will review the current CMP portfolio and discuss future funding trends for the program. I will also describe recent activities in the program aimed at addressing the challenges facing current and future principal investigators.

  17. Unique condensation patterns of triplex DNA: physical aspects and physiological implications

    PubMed Central

    Goobes, Rivka; Cohen, Orit; Minsky, Abraham

    2002-01-01

    Triple-stranded DNA structures can be formed in living cells, either by native DNA sequences or following the application of antigene strategies, in which triplex-forming oligonucleotides are targeted to the nucleus. Recent studies imply that triplex motifs may play a role in DNA transcription, recombination and condensation processes in vivo. Here we show that very short triple-stranded DNA motifs, but not double-stranded segments of a comparable length, self-assemble into highly condensed and ordered structures. The condensation process, studied by circular dichroism and polarized-light microscopy, occurs under conditions that mimic cellular environments in terms of ionic strength, ionic composition and crowding. We argue that the unique tendency of triplex DNA structures to self-assemble, a priori unexpected in light of the very short length and the large charge density of these motifs, reflects the presence of strong attractive interactions that result from enhanced ion correlations. The results provide, as such, a direct experimental link between charge density, attractive interactions between like-charge polymers and DNA packaging. Moreover, the observations strongly support the notion that triple-stranded DNA motifs may be involved in the regulation of chromosome organization in living cells. PMID:12000835

  18. Application of the string method to the study of critical nuclei in capillary condensation.

    PubMed

    Qiu, Chunyin; Qian, Tiezheng; Ren, Weiqing

    2008-10-21

    We adopt a continuum description for liquid-vapor phase transition in the framework of mean-field theory and use the string method to numerically investigate the critical nuclei for capillary condensation in a slit pore. This numerical approach allows us to determine the critical nuclei corresponding to saddle points of the grand potential function in which the chemical potential is given in the beginning. The string method locates the minimal energy path (MEP), which is the most probable transition pathway connecting two metastable/stable states in configuration space. From the MEP, the saddle point is determined and the corresponding energy barrier also obtained (for grand potential). Moreover, the MEP shows how the new phase (liquid) grows out of the old phase (vapor) along the most probable transition pathway, from the birth of a critical nucleus to its consequent expansion. Our calculations run from partial wetting to complete wetting with a variable strength of attractive wall potential. In the latter case, the string method presents a unified way for computing the critical nuclei, from film formation at solid surface to bulk condensation via liquid bridge. The present application of the string method to the numerical study of capillary condensation shows the great power of this method in evaluating the critical nuclei in various liquid-vapor phase transitions.

  19. Dynamical evolution of comet nucleus rotation

    NASA Astrophysics Data System (ADS)

    Scheeres, D. J.; Sidorenko, V. V.; Neishtadt, A. I.; Vasiliev, A. A.

    2002-09-01

    The rotational dynamics of outgassing cometary nuclei are investigated analytically. We develop a general theory for the evolution of a comet nucleus' rotation state using averaging theory and assuming that the outgassing torques are a function of solar insolation and heliocentric distance. The resulting solutions are a function of the nucleus inertia ellipsoid, its outgassing properties, its heliocentric orbit, and the assumed distribution of active regions on its surface. We find that the long-term evolution of the comet nucleus rotation is a strong function of the distribution of active regions over its surface. In particular, we find that nuclei with nearly axisymmetric inertia ellipsoids and a uniformly active surface will tend towards a rotation state that has a nutation angle of ~ 55 degrees and its angular momentum perpendicular to the sun-perihelion direction. If such a comet nucleus has only one isolated active region, it will tend towards a zero nutation angle with its approximate symmetry axis and rotational angular momentum aligned parallel to the sun-perihelion direction. In the general case for an inertia ellipsoid that is not close to being axisymmetric we find a much richer set of possible steady-state solutions that are stable, ranging from rotation about the maximum moment of the inertia axis, to SAM and LAM non-principal axis rotation states. The resulting stable rotation states are a strong function of outgassing activity distribution, which we show using a simplified model of the comet Halley nucleus. Also, we demonstrate that comet Borrely observations are consistent with a stable rotation state. Our results can be used to discriminate between competing theories of comet outgassing based on a nucelus' rotation state. They also allow for a range of plausible a priori constraints to be placed on a comet's rotation state to aid in the interpretation of its outgassing structure. This work was supported by the NASA JURRISS program under Grant NAG5

  20. Dropwise condensation over superhydrophobic aluminium surfaces

    NASA Astrophysics Data System (ADS)

    Parin, R.; Del, D., Col; Bortolin, S.; Martucci, A.

    2016-09-01

    Superhydrophobic aluminum surfaces have been analyzed being a promising solution to promote dropwise condensation. Superhydrophobicity has been obtained on an aluminum substrate by etching it with two different reagents and by depositing a fluorosilane film over them to lower the surface energy. The samples are characterized by means of contact angle measurements and Scanning Electron Microscopy (SEM). Experimental tests of pure steam condensation have been carried out on the samples and DWC has been visualized. Images of the dropwise condensation have been captured with high speed camera and, furthermore, the phenomenon of the jumping droplets has been observed. A heat transfer coefficient higher than 50 kW m-2 K-1 has been measured over the samples.