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Sample records for pumped nanolaser based

  1. Plasmon-Assisted Nd(3+)-Based Solid-State Nanolaser.

    PubMed

    Molina, Pablo; Yraola, Eduardo; Ramírez, Mariola O; Tserkezis, Christos; Plaza, José L; Aizpurua, Javier; Bravo-Abad, Jorge; Bausá, Luisa E

    2016-02-10

    Solid-state lasers constitute essential tools in a variety of scientific and technological areas, being available in many different designs. However, although nanolasing has been successfully achieved for dyes and semiconductor gain media associated with plasmonic structures, the operation of solid-state lasers beyond the diffraction limit has not been reported yet. Here, we demonstrate room temperature laser action with subwavelength confinement in a Nd(3+)-based solid-state laser by means of the localized surface plasmon resonances supported by chains of metallic nanoparticles. We show a 50% reduction of the pump power at threshold and a remarkable 15-fold improvement of the slope efficiency with respect to the bulk laser operation. The results can be extended to the large diversity of solid-state lasers with the subsequent impact on their applications. PMID:26751848

  2. Plasmon-Assisted Nd(3+)-Based Solid-State Nanolaser.

    PubMed

    Molina, Pablo; Yraola, Eduardo; Ramírez, Mariola O; Tserkezis, Christos; Plaza, José L; Aizpurua, Javier; Bravo-Abad, Jorge; Bausá, Luisa E

    2016-02-10

    Solid-state lasers constitute essential tools in a variety of scientific and technological areas, being available in many different designs. However, although nanolasing has been successfully achieved for dyes and semiconductor gain media associated with plasmonic structures, the operation of solid-state lasers beyond the diffraction limit has not been reported yet. Here, we demonstrate room temperature laser action with subwavelength confinement in a Nd(3+)-based solid-state laser by means of the localized surface plasmon resonances supported by chains of metallic nanoparticles. We show a 50% reduction of the pump power at threshold and a remarkable 15-fold improvement of the slope efficiency with respect to the bulk laser operation. The results can be extended to the large diversity of solid-state lasers with the subsequent impact on their applications.

  3. Towards Photonic-Plasmonic Integrated Circuits: Study and Fabrication Of Electrically-Pumped Plasmonic Nano-Laser

    NASA Astrophysics Data System (ADS)

    Hseih, Chunhan Michael

    For the next generation of optical communication, Photonic Integrated Circuits (PIC) and optoelectronic integrated circuits has been of great interest because of the possibility of integrating multiple optical components and electronics together to give high performance opto-electronic system on a small chip that can be produced cost-effectively. Integrated semiconductor laser, as the main light source for generating signals in optical communications, is one of the most important function on a photonic integrated circuit. In the recent advancements in nanophotonics, strong confinement of light in strongly-guiding optical waveguide structure comparing to conventional structures, has been used to improve certain performances of on-chip semiconductor lasers and miniaturize the laser device sizes. However, compared to electronics, even with use of nanophotonic device technology, optoelectronic device footprints are still relatively large due to the diffraction limit of light, which poses a limit on the sizes of optoelectronic devices. Plasmonic photonic device area has been an intensive field of research that utilizes plamonic photonic waveguides to confine light smaller than the diffraction limit through the effect of surface plasmon polariton, a coupling between photons and plasmon along a metal-dielectric interface. In this dissertation, an electrically pumped Plasmonic nanolaser has been designed using 2D-FDTD simulation. The nanolaser has the potential of lasing utilizing achievable optical gain in the typical compound (group III-V) semiconductor materials. The laser electrical pumping structure is compatible with device integration on silicon photonics platform utilizing silicon-on-insulator (SOI) substrate. Electrically pumped thin film based laser structure is shown to be realizable with the use of TCO material as transparent electrodes on the waveguide cladding. Indium oxide (In2O3) and Zinc-Indium-Tin-Oxide (ZITO) deposited by ion-beam-assisted deposition

  4. Ultrahigh Purcell factor in low-threshold nanolaser based on asymmetric hybrid plasmonic cavity

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Yan, Xin; Zhang, Xia

    2016-09-01

    A low-threshold nanolaser with all three dimensions at the subwavelength scale is proposed and investigated. The nanolaser is constructed based on an asymmetric hybrid plasmonic F-P cavity with Ag-coated end facets. Lasing characteristics are calculated using finite element method at the wavelength of 1550 nm. The results show that owing to the low modal loss, large modal confinement factor of the asymmetric plasmonic cavity structure, in conjunction with the high reflectivity of the Ag reflectors, a minimum threshold gain of 240 cm-1 is predicted. Furthermore, the Purcell factor as large as 2518 is obtained with optimized structure parameters to enhance rates of spontaneous and stimulated emission.

  5. Ultrahigh Purcell factor in low-threshold nanolaser based on asymmetric hybrid plasmonic cavity.

    PubMed

    Wei, Wei; Yan, Xin; Zhang, Xia

    2016-01-01

    A low-threshold nanolaser with all three dimensions at the subwavelength scale is proposed and investigated. The nanolaser is constructed based on an asymmetric hybrid plasmonic F-P cavity with Ag-coated end facets. Lasing characteristics are calculated using finite element method at the wavelength of 1550 nm. The results show that owing to the low modal loss, large modal confinement factor of the asymmetric plasmonic cavity structure, in conjunction with the high reflectivity of the Ag reflectors, a minimum threshold gain of 240 cm(-1) is predicted. Furthermore, the Purcell factor as large as 2518 is obtained with optimized structure parameters to enhance rates of spontaneous and stimulated emission. PMID:27616768

  6. Ultrahigh Purcell factor in low-threshold nanolaser based on asymmetric hybrid plasmonic cavity

    PubMed Central

    Wei, Wei; Yan, Xin; Zhang, Xia

    2016-01-01

    A low-threshold nanolaser with all three dimensions at the subwavelength scale is proposed and investigated. The nanolaser is constructed based on an asymmetric hybrid plasmonic F-P cavity with Ag-coated end facets. Lasing characteristics are calculated using finite element method at the wavelength of 1550 nm. The results show that owing to the low modal loss, large modal confinement factor of the asymmetric plasmonic cavity structure, in conjunction with the high reflectivity of the Ag reflectors, a minimum threshold gain of 240 cm−1 is predicted. Furthermore, the Purcell factor as large as 2518 is obtained with optimized structure parameters to enhance rates of spontaneous and stimulated emission. PMID:27616768

  7. Nano-laser on silicon quantum dots

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Qi; Liu, Shi-Rong; Qin, Chao-Jian; Lü, Quan; Xu, Li

    2011-04-01

    A new conception of nano-laser is proposed in which depending on the size of nano-clusters (silicon quantum dots (QD)), the pumping level of laser can be tuned by the quantum confinement (QC) effect, and the population inversion can be formed between the valence band and the localized states in gap produced from the surface bonds of nano-clusters. Here we report the experimental demonstration of nano-laser on silicon quantum dots fabricated by nanosecond pulse laser. The peaks of stimulated emission are observed at 605 nm and 693 nm. Through the micro-cavity of nano-laser, a full width at half maximum of the peak at 693 nm can reach to 0.5 nm. The theoretical model and the experimental results indicate that it is a necessary condition for setting up nano-laser that the smaller size of QD (d < 3 nm) can make the localized states into band gap. The emission energy of nano-laser will be limited in the range of 1.7-2.3 eV generally due to the position of the localized states in gap, which is in good agreement between the experiments and the theory.

  8. Dipole-dipole interaction between nanolaser and external atom

    NASA Astrophysics Data System (ADS)

    Larionov, N. V.

    2016-03-01

    We consider the single-emitter nanolaser coupled through dipole-dipole interaction with the external atom placed into the coherent pump field. We show that varying of the coherent pump parameters allows to control the quantum fluctuations of the laser field.

  9. Dipole nano-laser: Theory and properties

    SciTech Connect

    Ghannam, T.

    2014-03-31

    In this paper we outline the main quantum properties of the system of nano-based laser called Dipole Nano-Laser emphasizing mainly on its ability to produce coherent light and for different configurations such as different embedding materials and subjecting it to an external classical electric field.

  10. Semiconductor plasmonic nanolasers: current status and perspectives

    NASA Astrophysics Data System (ADS)

    Gwo, Shangjr; Shih, Chih-Kang

    2016-08-01

    Scaling down semiconductor lasers in all three dimensions holds the key to the development of compact, low-threshold, and ultrafast coherent light sources, as well as integrated optoelectronic and plasmonic circuits. However, the minimum size of conventional semiconductor lasers utilizing dielectric cavity resonators (photonic cavities) is limited by the diffraction limit. To date, surface plasmon amplification by stimulated emission of radiation (spaser)-based plasmonic nanolaser is the only photon and plasmon-emitting device capable of this remarkable feat. Specifically, it has been experimentally demonstrated that the use of plasmonic cavities based on metal-insulator-semiconductor (MIS) nanostructures can indeed break the diffraction limit in all three dimensions. In this review, we present an updated overview of the current status for plasmonic nanolasers using the MIS configuration and other related metal-cladded semiconductor microlasers. In particular, by using composition-varied indium gallium nitride/gallium nitride core–shell nanorods, it is possible to realize all-color, single-mode nanolasers in the full visible wavelength range with ultralow continuous-wave (CW) lasing thresholds. The lasing action in these subdiffraction plasmonic cavities is achieved via a unique auto-tuning mechanism based on the property of weak size dependence inherent in plasmonic nanolasers. As for the choice of metals in the plasmonic structures, epitaxial silver films and giant colloidal silver crystals have been shown to be the superior constituent materials for plasmonic cavities due to their low plasmonic losses in the visible and near-infrared (NIR) spectral regions. In this review, we also provide some perspectives on the challenges and opportunities in this exciting new research frontier.

  11. Semiconductor plasmonic nanolasers: current status and perspectives.

    PubMed

    Gwo, Shangjr; Shih, Chih-Kang

    2016-08-01

    Scaling down semiconductor lasers in all three dimensions holds the key to the development of compact, low-threshold, and ultrafast coherent light sources, as well as integrated optoelectronic and plasmonic circuits. However, the minimum size of conventional semiconductor lasers utilizing dielectric cavity resonators (photonic cavities) is limited by the diffraction limit. To date, surface plasmon amplification by stimulated emission of radiation (spaser)-based plasmonic nanolaser is the only photon and plasmon-emitting device capable of this remarkable feat. Specifically, it has been experimentally demonstrated that the use of plasmonic cavities based on metal-insulator-semiconductor (MIS) nanostructures can indeed break the diffraction limit in all three dimensions. In this review, we present an updated overview of the current status for plasmonic nanolasers using the MIS configuration and other related metal-cladded semiconductor microlasers. In particular, by using composition-varied indium gallium nitride/gallium nitride core-shell nanorods, it is possible to realize all-color, single-mode nanolasers in the full visible wavelength range with ultralow continuous-wave (CW) lasing thresholds. The lasing action in these subdiffraction plasmonic cavities is achieved via a unique auto-tuning mechanism based on the property of weak size dependence inherent in plasmonic nanolasers. As for the choice of metals in the plasmonic structures, epitaxial silver films and giant colloidal silver crystals have been shown to be the superior constituent materials for plasmonic cavities due to their low plasmonic losses in the visible and near-infrared (NIR) spectral regions. In this review, we also provide some perspectives on the challenges and opportunities in this exciting new research frontier. PMID:27459210

  12. Semiconductor plasmonic nanolasers: current status and perspectives

    NASA Astrophysics Data System (ADS)

    Gwo, Shangjr; Shih, Chih-Kang

    2016-08-01

    Scaling down semiconductor lasers in all three dimensions holds the key to the development of compact, low-threshold, and ultrafast coherent light sources, as well as integrated optoelectronic and plasmonic circuits. However, the minimum size of conventional semiconductor lasers utilizing dielectric cavity resonators (photonic cavities) is limited by the diffraction limit. To date, surface plasmon amplification by stimulated emission of radiation (spaser)-based plasmonic nanolaser is the only photon and plasmon-emitting device capable of this remarkable feat. Specifically, it has been experimentally demonstrated that the use of plasmonic cavities based on metal-insulator-semiconductor (MIS) nanostructures can indeed break the diffraction limit in all three dimensions. In this review, we present an updated overview of the current status for plasmonic nanolasers using the MIS configuration and other related metal-cladded semiconductor microlasers. In particular, by using composition-varied indium gallium nitride/gallium nitride core-shell nanorods, it is possible to realize all-color, single-mode nanolasers in the full visible wavelength range with ultralow continuous-wave (CW) lasing thresholds. The lasing action in these subdiffraction plasmonic cavities is achieved via a unique auto-tuning mechanism based on the property of weak size dependence inherent in plasmonic nanolasers. As for the choice of metals in the plasmonic structures, epitaxial silver films and giant colloidal silver crystals have been shown to be the superior constituent materials for plasmonic cavities due to their low plasmonic losses in the visible and near-infrared (NIR) spectral regions. In this review, we also provide some perspectives on the challenges and opportunities in this exciting new research frontier.

  13. Photonic Crystal Nanolaser Biosensors

    NASA Astrophysics Data System (ADS)

    Kita, Shota; Otsuka, Shota; Hachuda, Shoji; Endo, Tatsuro; Imai, Yasunori; Nishijima, Yoshiaki; Misawa, Hiroaki; Baba, Toshihiko

    High-performance and low-cost sensors are critical devices for high-throughput analyses of bio-samples in medical diagnoses and life sciences. In this paper, we demonstrate photonic crystal nanolaser sensor, which detects the adsorption of biomolecules from the lasing wavelength shift. It is a promising device, which balances a high sensitivity, high resolution, small size, easy integration, simple setup and low cost. In particular with a nanoslot structure, it achieves a super-sensitivity in protein sensing whose detection limit is three orders of magnitude lower than that of standard surface-plasmon-resonance sensors. Our investigations indicate that the nanoslot acts as a protein condenser powered by the optical gradient force, which arises from the strong localization of laser mode in the nanoslot.

  14. Lunar base heat pump

    NASA Technical Reports Server (NTRS)

    Goldman, Jeffrey H.; Tetreault, R.; Fischbach, D.; Walker, D.

    1994-01-01

    A heat pump is a device which elevates the temperature of a heat flow by a means of an energy input. By doing this, the heat pump can cause heat to transfer faster from a warm region to a cool region, or it can cause heat to flow from a cool region to a warmer region. The second case is the one which finds vast commercial applications such as air conditioning, heating, and refrigeration. Aerospace applications of heat pumps include both cases. The NASA Johnson Space Center is currently developing a Life Support Systems Integration Facility (LSSIF, previously SIRF) to provide system-level integration, operational test experience, and performance data that will enable NASA to develop flight-certified hardware for future planetary missions. A high lift heat pump is a significant part of the TCS hardware development associated with the LSSIF. The high lift heat pump program discussed here is being performed in three phases. In Phase 1, the objective is to develop heat pump concepts for a lunar base, a lunar lander, and for a ground development unit for the SIRF. In Phase 2, the design of the SIRF ground test unit is being performed, including identification and evaluation of safety and reliability issues. In Phase 3, the SIRF unit will be manufactured, tested, and delivered to the NASA Johnson Space Center.

  15. Lunar Base Heat Pump

    NASA Technical Reports Server (NTRS)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  16. ZnO nanolasers on graphene films

    NASA Astrophysics Data System (ADS)

    Baek, Hyeonjun; Park, Jun Beom; Park, Jong-woo; Hyun, Jerome K.; Yoon, Hosang; Oh, Hongseok; Yoon, Jiyoung

    2016-06-01

    We grew and characterized zinc oxide (ZnO) nanolasers on graphene films. By using graphene as a growth medium, we were able to prepare position-controlled and vertically aligned ZnO nanotube lasers. The ZnO nanolasers grown on graphene films showed good optical characteristics, evidenced by a low lasing threshold. Furthermore, the nanolaser/graphene system was easily lifted off the original substrate and transferred onto foreign substrates. The lasing performance was observed to be significantly enhanced by depositing a layer of silver on the back of the graphene film during this transfer process, which was quantitatively investigated using finite-difference time-domain simulations. Due to the wide selection of substrates enabled by the use of graphene films, our results suggest promising strategies for preparing practical nanolasers with improved performance.

  17. A high-resolution strain-gauge nanolaser

    PubMed Central

    Choi, Jae-Hyuck; No, You-Shin; So, Jae-Pil; Lee, Jung Min; Kim, Kyoung-Ho; Hwang, Min-Soo; Kwon, Soon-Hong; Park, Hong-Gyu

    2016-01-01

    Interest in mechanical compliance has been motivated by the development of flexible electronics and mechanosensors. In particular, studies and characterization of structural deformation at the fundamental scale can offer opportunities to improve the device sensitivity and spatiotemporal response; however, the development of precise measurement tools with the appropriate resolution remains a challenge. Here we report a flexible and stretchable photonic crystal nanolaser whose spectral and modal behaviours are sensitive to nanoscale structural alterations. Reversible spectral tuning of ∼26 nm in lasing wavelength, with a sub-nanometre resolution of less than ∼0.6 nm, is demonstrated in response to applied strain ranging from −10 to 12%. Instantaneous visualization of the sign of the strain is also characterized by exploring the structural and corresponding modal symmetry. Furthermore, our high-resolution strain-gauge nanolaser functions as a stable and deterministic strain-based pH sensor in an opto-fluidic system, which may be useful for further analysis of chemical/biological systems. PMID:27175544

  18. A high-resolution strain-gauge nanolaser.

    PubMed

    Choi, Jae-Hyuck; No, You-Shin; So, Jae-Pil; Lee, Jung Min; Kim, Kyoung-Ho; Hwang, Min-Soo; Kwon, Soon-Hong; Park, Hong-Gyu

    2016-01-01

    Interest in mechanical compliance has been motivated by the development of flexible electronics and mechanosensors. In particular, studies and characterization of structural deformation at the fundamental scale can offer opportunities to improve the device sensitivity and spatiotemporal response; however, the development of precise measurement tools with the appropriate resolution remains a challenge. Here we report a flexible and stretchable photonic crystal nanolaser whose spectral and modal behaviours are sensitive to nanoscale structural alterations. Reversible spectral tuning of ∼26 nm in lasing wavelength, with a sub-nanometre resolution of less than ∼0.6 nm, is demonstrated in response to applied strain ranging from -10 to 12%. Instantaneous visualization of the sign of the strain is also characterized by exploring the structural and corresponding modal symmetry. Furthermore, our high-resolution strain-gauge nanolaser functions as a stable and deterministic strain-based pH sensor in an opto-fluidic system, which may be useful for further analysis of chemical/biological systems. PMID:27175544

  19. A high-resolution strain-gauge nanolaser

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hyuck; No, You-Shin; So, Jae-Pil; Lee, Jung Min; Kim, Kyoung-Ho; Hwang, Min-Soo; Kwon, Soon-Hong; Park, Hong-Gyu

    2016-05-01

    Interest in mechanical compliance has been motivated by the development of flexible electronics and mechanosensors. In particular, studies and characterization of structural deformation at the fundamental scale can offer opportunities to improve the device sensitivity and spatiotemporal response; however, the development of precise measurement tools with the appropriate resolution remains a challenge. Here we report a flexible and stretchable photonic crystal nanolaser whose spectral and modal behaviours are sensitive to nanoscale structural alterations. Reversible spectral tuning of ~26 nm in lasing wavelength, with a sub-nanometre resolution of less than ~0.6 nm, is demonstrated in response to applied strain ranging from -10 to 12%. Instantaneous visualization of the sign of the strain is also characterized by exploring the structural and corresponding modal symmetry. Furthermore, our high-resolution strain-gauge nanolaser functions as a stable and deterministic strain-based pH sensor in an opto-fluidic system, which may be useful for further analysis of chemical/biological systems.

  20. Ultrastrong Mode Confinement in ZnO Surface Plasmon Nanolasers.

    PubMed

    Chou, Yu-Hsun; Chou, Bo-Tsun; Chiang, Chih-Kai; Lai, Ying-Yu; Yang, Chun-Ting; Li, Heng; Lin, Tzy-Rong; Lin, Chien-Chung; Kuo, Hao-Chung; Wang, Shing-Chung; Lu, Tien-Chang

    2015-01-01

    Nanolasers with an ultracompact footprint can provide high-intensity coherent light, which can be potentially applied to high-capacity signal processing, biosensing, and subwavelength imaging. Among various nanolasers, those with cavities surrounded by metals have been shown to have superior light emission properties because of the surface plasmon effect that provides enhanced field confinement capability and enables exotic light-matter interaction. In this study, we demonstrated a robust ultraviolet ZnO nanolaser that can operate at room temperature by using silver to dramatically shrink the mode volume. The nanolaser shows several distinct features including an extremely small mode volume, a large Purcell factor, and a slow group velocity, which ensures strong interaction with the exciton in the nanowire. PMID:25853853

  1. Rigorous theoretical analysis of a surface-plasmon nanolaser with monolayer MoS2 gain medium.

    PubMed

    Meng, Xiang; Grote, Richard R; Jin, Wencan; Dadap, Jerry I; Panoiu, Nicolae C; Osgood, Richard M

    2016-06-01

    Lasers based on monolayer (ML) transition-metal dichalcogenide semiconductor crystals have the potential for low threshold operation and a small device footprint; however, nanophotonic engineering is required to maximize the interaction between the optical fields and the three-atom-thick gain medium. Here, we develop a theoretical model to design a direct bandgap optically pumped nanophotonic integrated laser. Our device utilizes a gap-surface-plasmon optical mode to achieve subwavelength optical confinement and consists of a high-index GaP nanowire atop an ML MoS2 film on an Ag substrate. The optical field and material medium are analyzed using a three dimensional finite-difference time-domain method and a first-principles calculation based on the density functional theory, respectively. The nanolaser is designed to have a threshold of ∼0.6  μW under quasi-continuous wave operation on an excitonic transition at room temperature. PMID:27244433

  2. Random nanolasing in the Anderson localized regime

    NASA Astrophysics Data System (ADS)

    Liu, J.; Garcia, P. D.; Ek, S.; Gregersen, N.; Suhr, T.; Schubert, M.; Mørk, J.; Stobbe, S.; Lodahl, P.

    2014-04-01

    The development of nanoscale optical devices for classical and quantum photonics is affected by unavoidable fabrication imperfections that often impose performance limitations. However, disorder may also enable new functionalities, for example in random lasers, where lasing relies on random multiple scattering. The applicability of random lasers has been limited due to multidirectional emission, lack of tunability, and strong mode competition with chaotic fluctuations due to a weak mode confinement. The regime of Anderson localization of light has been proposed for obtaining stable multimode random lasing, and initial work concerned macroscopic one-dimensional layered media. Here, we demonstrate on-chip random nanolasers where the cavity feedback is provided by the intrinsic disorder. The strong confinement achieved by Anderson localization reduces the spatial overlap between lasing modes, thus preventing mode competition and improving stability. This enables highly efficient, stable and broadband wavelength-controlled lasers with very small mode volumes. Furthermore, the complex interplay between gain, dispersion-controlled slow light, and disorder is demonstrated experimentally for a non-conservative random medium. The statistical analysis shows a way towards optimizing random-lasing performance by reducing the localization length, a universal parameter.

  3. Nano-lasers and nano-LEDs

    NASA Astrophysics Data System (ADS)

    Willander, Magnus

    2014-03-01

    One-dimensional nanostructures have been of great interest for photonic devices. In this talk I will give a review of the one-dimensional ZnO nanostructures for ultraviolet and visible regions. I will discuss earlier and last results regarding room temperature and low temperature spontaneous and stimulated emission. For lasers we will discuss both optically and electrically pumped lasers. For the LEDs particularly I will discuss the white light emission from LEDs. Substrates like graphene, paper, textile and semiconductors will be discussed. Finally, also results from other devices based on hybrid materials will be analyzed.

  4. Array integration of thousands of photonic crystal nanolasers

    NASA Astrophysics Data System (ADS)

    Watanabe, Takumi; Abe, Hiroshi; Nishijima, Yoshiaki; Baba, Toshihiko

    2014-03-01

    Photonic crystal (PC) nanolasers often consist of air-bridge PC slab, which enhances optical confinement while limiting its size to 30 × 30 μm2 due to the mechanical fragileness. This limit is broken by resin-mediated bonding of the PC slab on a host substrate. In this paper, we demonstrate a GaInAsP PC slab with a size of over 100 × 100 μm2 in which 1089, 2376, and 11 664 nanolasers showing high-yield laser operation are integrated.

  5. Array integration of thousands of photonic crystal nanolasers

    SciTech Connect

    Watanabe, Takumi Abe, Hiroshi; Nishijima, Yoshiaki; Baba, Toshihiko

    2014-03-24

    Photonic crystal (PC) nanolasers often consist of air-bridge PC slab, which enhances optical confinement while limiting its size to 30 × 30 μm{sup 2} due to the mechanical fragileness. This limit is broken by resin-mediated bonding of the PC slab on a host substrate. In this paper, we demonstrate a GaInAsP PC slab with a size of over 100 × 100 μm{sup 2} in which 1089, 2376, and 11 664 nanolasers showing high-yield laser operation are integrated.

  6. Lunar base heat pump, phase 1

    NASA Technical Reports Server (NTRS)

    Goldman, Jeffrey H.; Harvey, A.; Lovell, T.; Walker, David H.

    1994-01-01

    This report describes the Phase 1 process and analysis used to select a refrigerant and thermodynamic cycle as the basis of a vapor compression heat pump requiring a high temperature lift, then to perform a preliminary design to implement the selected concept, including major component selection. Use of a vapor compression heat pump versus other types was based on prior work performed for the Electric Power Research Institute. A high lift heat pump is needed to enable a thermal control system to remove heat down to 275 K from a habitable volume when the external thermal environment is severe. For example, a long-term lunar base habitat will reject heat from a space radiator to a 325 K environment. The first step in the selection process was to perform an optimization trade study, quantifying the effect of radiator operating temperature and heat pump efficiency on total system mass; then, select the radiator operating temperature corresponding to the lowest system mass. Total system mass included radiators, all heat pump components, and the power supply system. The study showed that lunar night operation, with no temperature lift, dictated the radiator size. To operate otherwise would require a high mass penalty to store power. With the defined radiation surface, and heat pump performances assumed to be from 40 percent to 60 percent of the Carnot ideal, the optimum heat rejection temperature ranged from 387 K to 377 K, as a function of heat pump performance. Refrigerant and thermodynamic cycles were then selected to best meet the previously determined design conditions. The system was then adapted as a ground-based prototype lifting temperature to 360 K (versus 385 K for flight unit) and using readily available commercial-grade components. Over 40 refrigerants, separated into wet and dry compression behavioral types, were considered in the selection process. Refrigerants were initially screened for acceptable critical temperature. The acceptable refrigerants were

  7. Cavity-free plasmonic nanolasing enabled by dispersionless stopped light

    PubMed Central

    Pickering, Tim; Hamm, Joachim M.; Page, A. Freddie; Wuestner, Sebastian; Hess, Ortwin

    2014-01-01

    When light is brought to a standstill, its interaction with gain media increases dramatically due to a singularity in the density of optical states. Concurrently, stopped light engenders an inherent and cavity-free feedback mechanism, similar in effect to the feedback that has been demonstrated and exploited in large-scale disordered media and random lasers. Here we study the spatial, temporal and spectral signatures of lasing in planar gain-enhanced nanoplasmonic structures at near-infrared frequencies and show that the stopped-light feedback mechanism allows for nanolasing without a cavity. We reveal that in the absence of cavity-induced feedback, the subwavelength lasing mode forms dynamically as a phase-locked superposition of quasi dispersion-free waveguide modes. This mechanism proves remarkably robust against interface roughness and offers a new route towards nanolasing, the experimental realization of ultra-thin surface emitting lasers, and cavity-free active quantum plasmonics. PMID:25230337

  8. Single-crystalline aluminum film for ultraviolet plasmonic nanolasers

    PubMed Central

    Chou, Bo-Tsun; Chou, Yu-Hsun; Wu, Yen-Mo; Chung, Yi-Cheng; Hsueh, Wei-Jen; Lin, Shih-Wei; Lu, Tien-Chang; Lin, Tzy-Rong; Lin, Sheng-Di

    2016-01-01

    Significant advances have been made in the development of plasmonic devices in the past decade. Plasmonic nanolasers, which display interesting properties, have come to play an important role in biomedicine, chemical sensors, information technology, and optical integrated circuits. However, nanoscale plasmonic devices, particularly those operating in the ultraviolet regime, are extremely sensitive to the metal and interface quality. Thus, these factors have a significant bearing on the development of ultraviolet plasmonic devices. Here, by addressing these material-related issues, we demonstrate a low-threshold, high-characteristic-temperature metal-oxide-semiconductor ZnO nanolaser that operates at room temperature. The template for the ZnO nanowires consists of a flat single-crystalline Al film grown by molecular beam epitaxy and an ultrasmooth Al2O3 spacer layer synthesized by atomic layer deposition. By effectively reducing the surface plasmon scattering and metal intrinsic absorption losses, the high-quality metal film and the sharp interfaces formed between the layers boost the device performance. This work should pave the way for the use of ultraviolet plasmonic nanolasers and related devices in a wider range of applications. PMID:26814581

  9. Single-crystalline aluminum film for ultraviolet plasmonic nanolasers.

    PubMed

    Chou, Bo-Tsun; Chou, Yu-Hsun; Wu, Yen-Mo; Chung, Yi-Cheng; Hsueh, Wei-Jen; Lin, Shih-Wei; Lu, Tien-Chang; Lin, Tzy-Rong; Lin, Sheng-Di

    2016-01-01

    Significant advances have been made in the development of plasmonic devices in the past decade. Plasmonic nanolasers, which display interesting properties, have come to play an important role in biomedicine, chemical sensors, information technology, and optical integrated circuits. However, nanoscale plasmonic devices, particularly those operating in the ultraviolet regime, are extremely sensitive to the metal and interface quality. Thus, these factors have a significant bearing on the development of ultraviolet plasmonic devices. Here, by addressing these material-related issues, we demonstrate a low-threshold, high-characteristic-temperature metal-oxide-semiconductor ZnO nanolaser that operates at room temperature. The template for the ZnO nanowires consists of a flat single-crystalline Al film grown by molecular beam epitaxy and an ultrasmooth Al2O3 spacer layer synthesized by atomic layer deposition. By effectively reducing the surface plasmon scattering and metal intrinsic absorption losses, the high-quality metal film and the sharp interfaces formed between the layers boost the device performance. This work should pave the way for the use of ultraviolet plasmonic nanolasers and related devices in a wider range of applications. PMID:26814581

  10. Which Breast Pump for Which Mother: An Evidenced-Based Approach to Individualizing Breast Pump Technology

    PubMed Central

    Meier, Paula P.; Patel, Aloka L.; Hoban, Rebecca; Engstrom, Janet L.

    2015-01-01

    The majority of new mothers in the United States use breast pumps in the first four months post-birth in order to achieve their personal human milk feeding goals. Although these mothers seek guidance from health care professionals with respect to the type and use of breast pumps, there are few evidence-based guidelines to guide this professional advice. This paper reviews the evidence to facilitate professional individualization of breast pump recommendations using three categories of literature: the infant as the gold standard to which the pump is compared; the degree of maternal breast pump dependency (e.g., the extent to which the breast pump replaces the infant for milk removal and mammary gland stimulation); and the stage of lactation for which the pump replaces the infant. This review can also serve to inform public and private payers with respect to individualizing breast pump type to mother-dyad characteristics. PMID:26914013

  11. Higher-order photon correlations in pulsed photonic crystal nanolasers

    SciTech Connect

    Elvira, D.; Hachair, X.; Braive, R.; Beaudoin, G.; Robert-Philip, I.; Sagnes, I.; Abram, I.; Beveratos, A.; Verma, V. B.; Baek, B.; Nam, S. W.; Stevens, M. J.; Dauler, E. A.

    2011-12-15

    We report on the higher-order photon correlations of a high-{beta} nanolaser under pulsed excitation at room temperature. Using a multiplexed four-element superconducting single-photon detector we measured g{sup (n)}(0-vector) with n=2,3,4. All orders of correlation display partially chaotic statistics, even at four times the threshold excitation power. We show that this departure from coherence and Poisson statistics is due to the quantum fluctuations associated with the small number of photons at the lasing threshold.

  12. Detection of endotoxin using a photonic crystal nanolaser

    NASA Astrophysics Data System (ADS)

    Takahashi, Daichi; Hachuda, Shoji; Watanabe, Takumi; Nishijima, Yoshiaki; Baba, Toshihiko

    2015-03-01

    Fast and reliable detection of endotoxin (ET) in medical equipment and pharmaceutical products is an essential precursor to clinical treatment. In this study, we demonstrate the use of shifts in wavelength of photonic crystal nanolasers for sensing the Limulus amebocyte lysate reaction, which is a standard method for detecting ET. From working curves of wavelength shift vs ET concentration, whose correlation factors were as high as 98%, we detected a required concentration of 0.001 EU/ml within 33 min and detected a low concentration of 0.0001 EU/ml.

  13. Detection of endotoxin using a photonic crystal nanolaser

    SciTech Connect

    Takahashi, Daichi; Hachuda, Shoji; Watanabe, Takumi; Nishijima, Yoshiaki; Baba, Toshihiko

    2015-03-30

    Fast and reliable detection of endotoxin (ET) in medical equipment and pharmaceutical products is an essential precursor to clinical treatment. In this study, we demonstrate the use of shifts in wavelength of photonic crystal nanolasers for sensing the Limulus amebocyte lysate reaction, which is a standard method for detecting ET. From working curves of wavelength shift vs ET concentration, whose correlation factors were as high as 98%, we detected a required concentration of 0.001 EU/ml within 33 min and detected a low concentration of 0.0001 EU/ml.

  14. A handy liquid metal based electroosmotic flow pump.

    PubMed

    Gao, Meng; Gui, Lin

    2014-06-01

    A room temperature liquid metal based electroosmotic flow (EOF) pump has been proposed in this work. This low-cost EOF pump is convenient for both fabrication and integration. It utilizes polydimethylsiloxane (PDMS) microchannels filled with the liquid-metal as non-contact pump electrodes. The electrode channels are fabricated symmetrically to both sides of the pumping channel, having no contact with the pumping channel. To test the pumping performance of the EOF pump, the mean flow velocities of the fluid (DI water) in the EOF pumps were experimentally measured by tracing the fluorescent microparticles in the flow. To provide guidance for designing a low voltage EOF pump, parametric studies on dimensions of the electrode and pumping channels were performed in this work. According to the experimental results, the pumping speed can reach 5.93 μm s(-1) at a driving voltage of only 1.6 V, when the gap between the electrode and the pumping channel is 20 μm. Injecting a room temperature liquid metal into microchannels can provide a simple, rapid, low-cost but accurately self-aligned way to fabricate microelectrodes for EOF pumps, which is a promising method to achieve the miniaturization and integration of the EOF pump in microfluidic systems. The non-contact liquid electrodes have no influence on the fluid in the pumping channel when pumping, reducing Joule heat generation and preventing gas bubble formation at the surface of electrodes. The pump has great potential to drive a wide range of fluids, such as drug reagents, cell suspensions and biological macromolecule solutions.

  15. A handy liquid metal based electroosmotic flow pump.

    PubMed

    Gao, Meng; Gui, Lin

    2014-06-01

    A room temperature liquid metal based electroosmotic flow (EOF) pump has been proposed in this work. This low-cost EOF pump is convenient for both fabrication and integration. It utilizes polydimethylsiloxane (PDMS) microchannels filled with the liquid-metal as non-contact pump electrodes. The electrode channels are fabricated symmetrically to both sides of the pumping channel, having no contact with the pumping channel. To test the pumping performance of the EOF pump, the mean flow velocities of the fluid (DI water) in the EOF pumps were experimentally measured by tracing the fluorescent microparticles in the flow. To provide guidance for designing a low voltage EOF pump, parametric studies on dimensions of the electrode and pumping channels were performed in this work. According to the experimental results, the pumping speed can reach 5.93 μm s(-1) at a driving voltage of only 1.6 V, when the gap between the electrode and the pumping channel is 20 μm. Injecting a room temperature liquid metal into microchannels can provide a simple, rapid, low-cost but accurately self-aligned way to fabricate microelectrodes for EOF pumps, which is a promising method to achieve the miniaturization and integration of the EOF pump in microfluidic systems. The non-contact liquid electrodes have no influence on the fluid in the pumping channel when pumping, reducing Joule heat generation and preventing gas bubble formation at the surface of electrodes. The pump has great potential to drive a wide range of fluids, such as drug reagents, cell suspensions and biological macromolecule solutions. PMID:24706096

  16. Simultaneous detection of refractive index and surface charges in nanolaser biosensors

    SciTech Connect

    Watanabe, Keisuke; Kishi, Yoji; Hachuda, Shoji; Watanabe, Takumi; Sakemoto, Mai; Nishijima, Yoshiaki; Baba, Toshihiko

    2015-01-12

    The emission intensity of a GaInAsP photonic crystal nanolaser is affected by the pH of the solution, in which the nanolaser is immersed. This phenomenon can be explained by the change in the redox potential, which modifies the filling of electrons at surface states of the semiconductor and hence the nonradiative surface recombination. This phenomenon allows the nanolaser to simultaneously and independently detect the refractive index and electric charges near the surface on the basis of the variation in emission wavelength and intensity, respectively. This paper demonstrates this function through alternate deposition of charged polyelectrolytes and hybridization of deoxyribonucleic acids.

  17. PUMPS

    DOEpatents

    Thornton, J.D.

    1959-03-24

    A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.

  18. Key techniques for space-based solar pumped semiconductor lasers

    NASA Astrophysics Data System (ADS)

    He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

    2014-12-01

    In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

  19. High-Operation-Temperature Plasmonic Nanolasers on Single-Crystalline Aluminum.

    PubMed

    Chou, Yu-Hsun; Wu, Yen-Mo; Hong, Kuo-Bin; Chou, Bo-Tsun; Shih, Jheng-Hong; Chung, Yi-Cheng; Chen, Peng-Yu; Lin, Tzy-Rong; Lin, Chien-Chung; Lin, Sheng-Di; Lu, Tien-Chang

    2016-05-11

    The recent development of plasmonics has overcome the optical diffraction limit and fostered the development of several important components including nanolasers, low-operation-power modulators, and high-speed detectors. In particular, the advent of surface-plasmon-polariton (SPP) nanolasers has enabled the development of coherent emitters approaching the nanoscale. SPP nanolasers widely adopted metal-insulator-semiconductor structures because the presence of an insulator can prevent large metal loss. However, the insulator is not necessary if permittivity combination of laser structures is properly designed. Here, we experimentally demonstrate a SPP nanolaser with a ZnO nanowire on the as-grown single-crystalline aluminum. The average lasing threshold of this simple structure is 20 MW/cm(2), which is four-times lower than that of structures with additional insulator layers. Furthermore, single-mode laser operation can be sustained at temperatures up to 353 K. Our study represents a major step toward the practical realization of SPP nanolasers. PMID:27089144

  20. Ultrafast nanolaser device for detecting cancer in a single live cell.

    SciTech Connect

    Gourley, Paul Lee; McDonald, Anthony Eugene

    2007-11-01

    Emerging BioMicroNanotechnologies have the potential to provide accurate, realtime, high throughput screening of live tumor cells without invasive chemical reagents when coupled with ultrafast laser methods. These optically based methods are critical to advancing early detection, diagnosis, and treatment of disease. The first year goals of this project are to develop a laser-based imaging system integrated with an in- vitro, live-cell, micro-culture to study mammalian cells under controlled conditions. In the second year, the system will be used to elucidate the morphology and distribution of mitochondria in the normal cell respiration state and in the disease state for normal and disease states of the cell. In this work we designed and built an in-vitro, live-cell culture microsystem to study mammalian cells under controlled conditions of pH, temp, CO2, Ox, humidity, on engineered material surfaces. We demonstrated viability of cell culture in the microsystem by showing that cells retain healthy growth rates, exhibit normal morphology, and grow to confluence without blebbing or other adverse influences of the material surfaces. We also demonstrated the feasibility of integrating the culture microsystem with laser-imaging and performed nanolaser flow spectrocytometry to carry out analysis of the cells isolated mitochondria.

  1. Polypyrrole-Based Implantable Electroactive Pump for Controlled Drug Microinjection.

    PubMed

    Yan, Bingxi; Li, Boyi; Kunecke, Forest; Gu, Zhen; Guo, Liang

    2015-07-15

    Implantable devices for long-lasting controlled insulin microinjection are of great value to diabetic patients. To address this need, we develop a flexible electroactive pump based on a biocompatible polypyrrole composite film that comprises a polypyrrole matrix and a macromolecular dopant of polycaprolactone-block-polytetrahydrofuran-block-polycaprolactone. Using phosphate-buffered saline as the electrolyte, this film demonstrates much higher electroactivity and reproducibility than conventional Cl--doped polypyrrole, making it an excellent actuator for driving an implantable pump. At a driving current density of 1 mA/cm2, the pump demonstrates a consistent output capacity of 10.5 at 0.35 μL/s over 20 cycles. This work paves the way for the development of an implantable electroactive pump to improve the quality of life of diabetics.

  2. The numerical simulation based on CFD of hydraulic turbine pump

    NASA Astrophysics Data System (ADS)

    Duan, X. H.; Kong, F. Y.; Liu, Y. Y.; Zhao, R. J.; Hu, Q. L.

    2016-05-01

    As the functions of hydraulic turbine pump including self-adjusting and compensation with each other, it is far-reaching to analyze its internal flow by the numerical simulation based on CFD, mainly including the pressure field and the velocity field in hydraulic turbine and pump.The three-dimensional models of hydraulic turbine pump are made by Pro/Engineer software;the internal flow fields in hydraulic turbine and pump are simulated numerically by CFX ANSYS software. According to the results of the numerical simulation in design condition, the pressure field and the velocity field in hydraulic turbine and pump are analyzed respectively .The findings show that the static pressure decreases systematically and the pressure gradient is obvious in flow area of hydraulic turbine; the static pressure increases gradually in pump. The flow trace is regular in suction chamber and flume without spiral trace. However, there are irregular traces in the turbine runner channels which contrary to that in flow area of impeller. Most of traces in the flow area of draft tube are spiral.

  3. Pumped shot noise in adiabatically modulated graphene-based double-barrier structures.

    PubMed

    Zhu, Rui; Lai, Maoli

    2011-11-16

    Quantum pumping processes are accompanied by considerable quantum noise. Based on the scattering approach, we investigated the pumped shot noise properties in adiabatically modulated graphene-based double-barrier structures. It is found that compared with the Poisson processes, the pumped shot noise is dramatically enhanced where the dc pumped current changes flow direction, which demonstrates the effect of the Klein paradox.

  4. Pumped shot noise in adiabatically modulated graphene-based double-barrier structures

    NASA Astrophysics Data System (ADS)

    Zhu, Rui; Lai, Maoli

    2011-11-01

    Quantum pumping processes are accompanied by considerable quantum noise. Based on the scattering approach, we investigated the pumped shot noise properties in adiabatically modulated graphene-based double-barrier structures. It is found that compared with the Poisson processes, the pumped shot noise is dramatically enhanced where the dc pumped current changes flow direction, which demonstrates the effect of the Klein paradox.

  5. Peristaltic pump-based low range pressure sensor calibration system

    SciTech Connect

    Vinayakumar, K. B.; Naveen Kumar, G.; Rajanna, K. E-mail: krajanna2011@gmail.com; Nayak, M. M.; Dinesh, N. S.

    2015-11-15

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  6. Peristaltic pump-based low range pressure sensor calibration system

    NASA Astrophysics Data System (ADS)

    Vinayakumar, K. B.; Naveen Kumar, G.; Nayak, M. M.; Dinesh, N. S.; Rajanna, K.

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  7. Peristaltic pump-based low range pressure sensor calibration system.

    PubMed

    Vinayakumar, K B; Naveen Kumar, G; Nayak, M M; Dinesh, N S; Rajanna, K

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory. PMID:26628178

  8. Peristaltic pump-based low range pressure sensor calibration system.

    PubMed

    Vinayakumar, K B; Naveen Kumar, G; Nayak, M M; Dinesh, N S; Rajanna, K

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  9. An Alternating Current Electroosmotic Pump Based on Conical Nanopore Membranes.

    PubMed

    Wu, Xiaojian; Ramiah Rajasekaran, Pradeep; Martin, Charles R

    2016-04-26

    Electroosmotic flow (EOF) is used to pump solutions through microfluidic devices and capillary electrophoresis columns. We describe here an EOF pump based on membrane EOF rectification, an electrokinetic phenomenon we recently described. EOF rectification requires membranes with asymmetrically shaped pores, and conical pores in a polymeric membrane were used here. We show here that solution flow through the membrane can be achieved by applying a symmetrical sinusoidal voltage waveform across the membrane. This is possible because the alternating current (AC) carried by ions through the pore is rectified, and we previously showed that rectified currents yield EOF rectification. We have investigated the effect of both the magnitude and frequency of the voltage waveform on flow rate through the membrane, and we have measured the maximum operating pressure. Finally, we show that operating in AC mode offers potential advantages relative to conventional DC-mode EOF pumps. PMID:27046145

  10. Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Hashi, S.; Ishiyama, K.

    2011-01-01

    This paper presents a centrifugal force based magnetic micro-pump for the pumping of blood. Most blood pumps are driven by an electrical motor with wired control. To develop a wireless and battery-free blood pump, the proposed pump is controlled by external rotating magnetic fields with a synchronized impeller. Synchronization occurs because the rotor is divided into multi-stage impeller parts and NdFeB permanent magnet. Finally, liquid is discharged by the centrifugal force of multi-stage impeller. The proposed pump length is 30 mm long and19 mm in diameter which much smaller than currently pumps; however, its pumping ability satisfies the requirement for a blood pump. The maximum pressure is 120 mmHg and the maximum flow rate is 5000ml/min at 100 Hz. The advantage of the proposed pump is that the general mechanical problems of a normal blood pump are eliminated by the proposed driving mechanism.

  11. A Physically Based Model for Air-Lift Pumping

    NASA Astrophysics Data System (ADS)

    FrançOis, Odile; Gilmore, Tyler; Pinto, Michael J.; Gorelick, Steven M.

    1996-08-01

    A predictive, physically based model for pumping water from a well using air injection (air-lift pumping) was developed for the range of flow rates that we explored in a series of laboratory experiments. The goal was to determine the air flow rate required to pump a specific flow rate of water in a given well, designed for in-well air stripping of volatile organic compounds from an aquifer. The model was validated against original laboratory data as well as data from the literature. A laboratory air-lift system was constructed that consisted of a 70-foot-long (21-m-long) pipe, 5.5 inches (14 cm) inside diameter, in which an air line of 1.3 inches (3.3 cm) outside diameter was placed with its bottom at different elevations above the base of the long pipe. Experiments were conducted for different levels of submergence, with water-pumping rates ranging from 5 to 70 gallons/min (0.32-4.4 L/s), and air flow ranging from 7 to 38 standard cubic feet/min (0.2-1.1 m3 STP/min). The theoretical approach adopted in the model was based on an analysis of the system as a one-dimensional two-phase flow problem. The expression for the pressure gradient includes inertial energy terms, friction, and gas expansion versus elevation. Data analysis revealed that application of the usual drift-flux model to estimate the air void fraction is not adequate for the observed flow patterns: either slug or churn flow. We propose a modified drift-flux model that accurately predicts air-lift pumping requirements for a range of conditions representative of in-well air-stripping operations.

  12. Digital background calibration of charge pump based pipelined ADC

    NASA Astrophysics Data System (ADS)

    Singh, Anil; Agarwal, Alpana

    2016-11-01

    In the presented work, digital background calibration of a charge pump based pipelined ADC is presented. A 10-bit 100 MS/s pipelined ADC is designed using TSMC 0.18 µm CMOS technology operating on a 1.8 V power supply voltage. A power efficient opamp-less charge pump based technique is chosen to achieve the desired stage voltage gain of 2 and digital background calibration is used to calibrate the inter-stage gain error. After calibration, the ADC achieves an SNDR of 66.78 dB and SFDR of 79.3 dB. Also, DNL improves to +0.6/-0.4 LSB and INL improves from +9.3/-9.6 LSB to within ±0.5 LSB, consuming 16.53 mW of power.

  13. Pipe flow of pumping wet shotcrete based on lubrication layer.

    PubMed

    Chen, Lianjun; Liu, Guoming; Cheng, Weimin; Pan, Gang

    2016-01-01

    Wet shotcrete can reduce dust and improve supporting strength, however, safe and efficient pipage is a key technical part of wet shotcrete process. The paper studied the pipe flow law of wet shotcrete based on lubrication layer by build the experimental pumping circuit of wet shotcrete that can carry out a number of full-scale pumping tests. The experimental results show there was a linear relationship between pressure loss and flow rate. Combined with the Buckingham rheological equation, the computing equations of the yield shear stress and plastic viscosity were deduced through linear regression. A simple analytical method allowing for a rough estimation of the pumping pressure was proposed and used when considering the lubrication layer of wet shotcrete in pipes. In addition, two kinds of particulate distributive models were established along the time axial to analyze the formation of lubrication layer which is related with particles migration. By computational fluid dynamics simulation, the lubrication layer thickness of different mix proportions was estimated. A new method for measuring the thickness of lubrication layer was proposed to verify it by binarization processing. Finally, according to the comparative analysis of experiments, simulation and computed value, it can be seen that the lubrication layer plays a key role in the process of wet shotcrete flow and with the increase of lubrication layer thickness pipe pressure declines gradually.

  14. Pipe flow of pumping wet shotcrete based on lubrication layer.

    PubMed

    Chen, Lianjun; Liu, Guoming; Cheng, Weimin; Pan, Gang

    2016-01-01

    Wet shotcrete can reduce dust and improve supporting strength, however, safe and efficient pipage is a key technical part of wet shotcrete process. The paper studied the pipe flow law of wet shotcrete based on lubrication layer by build the experimental pumping circuit of wet shotcrete that can carry out a number of full-scale pumping tests. The experimental results show there was a linear relationship between pressure loss and flow rate. Combined with the Buckingham rheological equation, the computing equations of the yield shear stress and plastic viscosity were deduced through linear regression. A simple analytical method allowing for a rough estimation of the pumping pressure was proposed and used when considering the lubrication layer of wet shotcrete in pipes. In addition, two kinds of particulate distributive models were established along the time axial to analyze the formation of lubrication layer which is related with particles migration. By computational fluid dynamics simulation, the lubrication layer thickness of different mix proportions was estimated. A new method for measuring the thickness of lubrication layer was proposed to verify it by binarization processing. Finally, according to the comparative analysis of experiments, simulation and computed value, it can be seen that the lubrication layer plays a key role in the process of wet shotcrete flow and with the increase of lubrication layer thickness pipe pressure declines gradually. PMID:27386389

  15. Magnetic plasmonic metamaterials in actively pumped host medium and plasmonic nanolaser

    NASA Astrophysics Data System (ADS)

    Sarychev, Andrey K.; Tartakovsky, Gennady

    2006-08-01

    We consider plasmonic nanoantennas immersed in active host medium. Specifically shaped metal nanoantennas can exhibit strong magnetic properties in the optical spectral range due to the excitation of Magnetic Resonance Plasmons (MRP). A case when a metamaterial comprising such nanoantennas can demonstrate both "left-handiness" and negative permeability in the optical range is considered. We show that high losses predicted for optical "left-handed" materials can be compensated in the gain medium. Gains required to achieve local generation in such magnetic active metamaterials are calculated for real metals

  16. Perspectives of Increasing Efficiency and Productivity of Electromagnetic Induction Pumps for Mercury Basing on Permanent Magnets

    SciTech Connect

    Bucenieks, I.

    2006-07-01

    In the next generation neutron sources the HLM (heavy liquid metals) such as lead, lead based eutectic alloys and mercury will be used both as spallation target material and simultaneously as the cooling liquid. In this aspect the design of safe and effective pumps for HLM recirculation at high pressure heads and big flow rates becomes important. For this purpose electromagnetic inductions pumps having no problems of hydraulic seals being in contact with liquid metal (electromagnetic forces in the liquid metal are induced by magnetic system located outside of the channel of pump) are more perspective from the point of view of their safety for operation at high temperature and radiation conditions in comparison with mechanical pumps. At the Institute of Physics of University of Latvia (IPUL) the design concept of electromagnetic induction pumps basing on the principle of rotating permanent magnets (PMP) have been developed. Such design concept of electromagnetic induction pumps has many advantages in comparison with traditionally used electromagnetic induction pumps basing on 3-phase linear flat or cylindrical inductors. The estimations of parameters of powerful pumps (such as overall dimensions of the active magnetic system, power of motor needed for pump drive, the efficiency of pump) for mercury for the developed by pump pressure heads in the range up to 10.0 bar and provided flow rates in the range up to 20 litres per second are demonstrated. (author)

  17. A fused side-pumping optical fiber coupler based on twisting

    NASA Astrophysics Data System (ADS)

    Yi, Bokai; Chang, Xinzu; Zhou, Xuanfeng; Chen, Zilun; Zhao, Guomin

    2014-12-01

    Pumping coupler technology is one of the critical technologies for high power laser and amplifier. Side-pumping technology can couple pumping beam into inner cladding of the double-clad fiber through the side of the fiber. Compared to the end-pumping technology by tapered fused bundle (TFB), it has many superiorities. That the signal fiber was not disconnected guarantees high transmission efficiency, providing the possibility of transmitting a high power signal. Additionally, the pump light is coupled into the double-cladding fiber all along the coupler's body (~5-10 cm long), which reduces the thermal effects caused by leakage of pumping light, resulting in high pump power handling capabilities. For the realization of reliable, rugged and efficient high power fiber amplifiers and fiber laser systems, a novel kind of fused side-pumping coupler based on twisting is developed. The complete simulations were carried out for the process of side-pumping. From detailed information about simulations, we found that the pump efficiencies, one of the vital parameters of pumping coupler, have a significant influence with coupling length, the numerical aperture (NA) and taper ratio of pump fiber. However, the diversification of the parameters drops the high transmission efficiency barely. Optimized the parameters in the simulations, the pump and signal coupling efficiencies are 97.3% and 99.4%, respectively. Based on theoretical analysis, the side-pumping coupler was demonstrated at the pump and signal coupling efficiencies are 91.2% and 98.4%, respectively. This fiber coupler can be implemented in almost any fiber laser or amplifier architecture.

  18. GaAs-based high temperature electrically pumped polariton laser

    SciTech Connect

    Baten, Md Zunaid; Bhattacharya, Pallab Frost, Thomas; Deshpande, Saniya; Das, Ayan; Lubyshev, Dimitri; Fastenau, Joel M.; Liu, Amy W. K.

    2014-06-09

    Strong coupling effects and polariton lasing are observed at 155 K with an edge-emitting GaAs-based microcavity diode with a single Al{sub 0.31}Ga{sub 0.69}As/Al{sub 0.41}Ga{sub 0.59}As quantum well as the emitter. The threshold for polariton lasing is observed at 90 A/cm{sup 2}, accompanied by a reduction of the emission linewidth to 0.85 meV and a blueshift of the emission wavelength by 0.89 meV. Polariton lasing is confirmed by the observation of a polariton population redistribution in momentum space and spatial coherence. Conventional photon lasing is recorded in the same device at higher pump powers.

  19. Pump-stopping water hammer simulation based on RELAP5

    NASA Astrophysics Data System (ADS)

    Yi, W. S.; Jiang, J.; Li, D. D.; Lan, G.; Zhao, Z.

    2013-12-01

    RELAP5 was originally designed to analyze complex thermal-hydraulic interactions that occur during either postulated large or small loss-of-coolant accidents in PWRs. However, as development continued, the code was expanded to include many of the transient scenarios that might occur in thermal-hydraulic systems. The fast deceleration of the liquid results in high pressure surges, thus the kinetic energy is transformed into the potential energy, which leads to the temporary pressure increase. This phenomenon is called water hammer. Generally water hammer can occur in any thermal-hydraulic systems and it is extremely dangerous for the system when the pressure surges become considerably high. If this happens and when the pressure exceeds the critical pressure that the pipe or the fittings along the pipeline can burden, it will result in the failure of the whole pipeline integrity. The purpose of this article is to introduce the RELAP5 to the simulation and analysis of water hammer situations. Based on the knowledge of the RELAP5 code manuals and some relative documents, the authors utilize RELAP5 to set up an example of water-supply system via an impeller pump to simulate the phenomena of the pump-stopping water hammer. By the simulation of the sample case and the subsequent analysis of the results that the code has provided, we can have a better understand of the knowledge of water hammer as well as the quality of the RELAP5 code when it's used in the water-hammer fields. In the meantime, By comparing the results of the RELAP5 based model with that of other fluid-transient analysis software say, PIPENET. The authors make some conclusions about the peculiarity of RELAP5 when transplanted into water-hammer research and offer several modelling tips when use the code to simulate a water-hammer related case.

  20. Nanolaser spectroscopy of Normal and Genetically Defective Mitochondria: New Biostatistical Tool for Studying Disease

    NASA Astrophysics Data System (ADS)

    Gourley, Paul; Hendricks, Judy; Naviaux, Robert; Yaffe, Michael

    2007-03-01

    We report an analysis of wild and mutant strains of mitochondria from yeast cells using nanolaser spectroscopy to measure cytochrome density and its statistical variation in the population. The first strain 110 was derived from wild-type strain 104 (Saccharomyces cerevisiae) by removal of its mitochondrial DNA (mtDNA), resulting in loss of all mtDNA-encoded proteins and RNAs, and loss of the pigmented, heme-containing cytochromes a and b that can be detected in the laser spectra. Histograms of laser wavelengths produced by wild-type mitochondria produced peaked distributions, while mutant mitochondria exhibit asymmetric, highly skewed distributions. Surprisingly, all of these distributions exhibit extended tails and can be self-consistently fit with log-normal distribution functions. In striking contrast, the mitochondrial diameters (measured separately by microscopy) exhibit normal Gaussian distributions. These results indicate that the nanolaser spectra are useful for quantifying cytochrome content in mitochondria and may have important implications for quantifying defects in mitochondria that manifest human disease.

  1. Nanolaser Spectroscopy of Genetically Engineered Yeast: New Tool for a Better Brew?

    NASA Astrophysics Data System (ADS)

    Gourley, Paul L.; Hendricks, Judy K.; Naviaux, Robert K.; Yaffe, Michael P.

    2006-03-01

    A basic function of the cell membrane is to selectively uptake ions or molecules from its environment to concentrate them into the interior. This concentration difference results in an osmostic pressure difference across the membrane. Ultimately, this pressure and its fluctuation from cell to cell will be limited by the availability and fluctuations of the solute concentrations in solution, the extent of inter-cell communication, and the state of respiring intracellular mitochondria that fuel the process. To measure these fluctuations, we have employed a high-speed nanolaser technique that samples the osmotic pressure in individual yeast cells and isolated mitochondria. We analyzed 2 yeast cell strains, normal baker’s yeast and a genetically-altered version, that differ only by the presence of mitochondrial DNA. The absence of mitochondrial DNA results in the complete loss of all the mtDNA-encoded proteins and RNAs, and loss of the pigmented, heme-containing cytochromes. These cells have mitochondria, but the mitochondria lack most normal respiratory chain complexes. The frequency distributions in the nanolaser spectra produced by wild-type and modified cells and mitochondria show a striking shift from Gaussian to Poissonian distributions, revealing a powerful novel method for studying statistical physics of yeast.

  2. Nanostructured carbon materials based electrothermal air pump actuators

    NASA Astrophysics Data System (ADS)

    Liu, Qing; Liu, Luqi; Kuang, Jun; Dai, Zhaohe; Han, Jinhua; Zhang, Zhong

    2014-05-01

    Actuator materials can directly convert different types of energy into mechanical energy. In this work, we designed and fabricated electrothermal air pump-type actuators by utilization of various nanostructured carbon materials, including single wall carbon nanotubes (SWCNTs), reduced graphene oxide (r-GO), and graphene oxide (GO)/SWCNT hybrid films as heating elements to transfer electrical stimulus into thermal energy, and finally convert it into mechanical energy. Both the actuation displacement and working temperature of the actuator films show the monotonically increasing trend with increasing driving voltage within the actuation process. Compared with common polymer nanocomposites based electrothermal actuators, our actuators exhibited better actuation performances with a low driving voltage (<10 V), large generated stress (tens of MPa), high gravimetric density (tens of J kg-1), and short response time (few hundreds of milliseconds). Besides that, the pump actuators exhibited excellent stability under cyclic actuation tests. Among these actuators, a relatively larger actuation strain was obtained for the r-GO film actuator due to the intrinsic gas-impermeability nature of graphene platelets. In addition, the high modulus of the r-GO and GO/SWCNT films also guaranteed the large generated stress and high work density. Specifically, the generated stress and gravimetric work density of the GO/SWCNT hybrid film actuator could reach up to more than 50 MPa and 30 J kg-1, respectively, under a driving voltage of 10 V. The resulting stress value is at least two orders of magnitude higher than that of natural muscles (~0.4 MPa).Actuator materials can directly convert different types of energy into mechanical energy. In this work, we designed and fabricated electrothermal air pump-type actuators by utilization of various nanostructured carbon materials, including single wall carbon nanotubes (SWCNTs), reduced graphene oxide (r-GO), and graphene oxide (GO)/SWCNT hybrid

  3. Diode-Laser Pumped Far-Infrared Local Oscillator Based on Semiconductor Quantum Wells

    NASA Technical Reports Server (NTRS)

    Kolokolov, K.; Li, J.; Ning, C. Z.; Larrabee, D. C.; Tang, J.; Khodaparast, G.; Kono, J.; Sasa, S.; Inoue, M.; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    The contents include: 1) Tetrahertz Field: A Technology Gap; 2) Existing THZ Sources and Shortcomings; 3) Applications of A THZ Laser; 4) Previous Optical Pumped LW Generations; 5) Optically Pumped Sb based Intersubband Generation Whys; 6) InGaAs/InP/AlAsSb QWs; 7) Raman Enhanced Optical Gain; 8) Pump Intensity Dependence of THZ Gain; 9) Pump-Probe Interaction Induced Raman Shift; 10) THZ Laser Gain in InGaAs/InP/AlAsSb QWs; 11) Diode-Laser Pumped Difference Frequency Generation (InGaAs/InP/AlAsSb QWs); 12) 6.1 Angstrom Semiconductor Quantum Wells; 13) InAs/GaSb/AlSb Nanostructures; 14) InAs/AlSb Double QWs: DFG Scheme; 15) Sb-Based Triple QWs: Laser Scheme; and 16) Exciton State Pumped THZ Generation. This paper is presented in viewgraph form.

  4. Sol-Gel Based Polybenzimidazole Membranes for Hydrogen Pumping Devices

    SciTech Connect

    Benicewicz, Brian

    2014-02-26

    Electrochemical hydrogen pumping using a high temperature (>100°C) PBI membrane was demonstrated under non-humidified and humidified conditions at ambient pressures. Relatively low voltages were required to operate the pump over a wide range of hydrogen flow rates. The advantages of the high temperature capability were shown by operating the pump on reformate feed gas mixtures containing various amounts of CO and CO{sub 2}. Gas purity measurements on the cathode gas product were conducted and significant reductions in gas impurities were detected. The applicability of the PBI membrane for electrochemical hydrogen pumping and its durability under typical operating conditions was established with tests that lasted for nearly 4000 hours.

  5. Electromagnetic liquid pistons for capillarity-based pumping.

    PubMed

    Malouin, Bernard A; Vogel, Michael J; Olles, Joseph D; Cheng, Lili; Hirsa, Amir H

    2011-02-01

    The small scales associated with lab-on-a-chip technologies lend themselves well to capillarity-dominated phenomena. We demonstrate a new capillarity-dominated system where two adjoining ferrofluid droplets can behave as an electronically-controlled oscillator or switch by an appropriate balance of magnetic, capillary, and inertial forces. Their oscillatory motion can be exploited to displace a surrounding liquid (akin to an axial piston pump), forming electromagnetic "liquid pistons." Such ferrofluid pistons can pump a precise volume of liquid via finely tunable amplitudes (cf. pump stroke) or resonant frequencies (cf. pump speed) with no solid moving parts for long-term operation without wear in a small device. Furthermore, the rapid propagation of electromagnetic fields and the favorable scaling of capillary forces with size permit micron sized devices with very fast operating speeds (∼kHz). The pumping dynamics and performance of these liquid pistons is explored, with experimental measurements showing good agreement with a spherical cap model. While these liquid pistons may find numerous applications in micro- and mesoscale fluidic devices (e.g., remotely activated drug delivery), here we demonstrate the use of these liquid pistons in capillarity-dominated systems for chip-level, fast-acting adaptive liquid lenses with nearly perfect spherical interfaces.

  6. Computational Fluid Dynamics-Based Design Optimization Method for Archimedes Screw Blood Pumps.

    PubMed

    Yu, Hai; Janiga, Gábor; Thévenin, Dominique

    2016-04-01

    An optimization method suitable for improving the performance of Archimedes screw axial rotary blood pumps is described in the present article. In order to achieve a more robust design and to save computational resources, this method combines the advantages of the established pump design theory with modern computer-aided, computational fluid dynamics (CFD)-based design optimization (CFD-O) relying on evolutionary algorithms and computational fluid dynamics. The main purposes of this project are to: (i) integrate pump design theory within the already existing CFD-based optimization; (ii) demonstrate that the resulting procedure is suitable for optimizing an Archimedes screw blood pump in terms of efficiency. Results obtained in this study demonstrate that the developed tool is able to meet both objectives. Finally, the resulting level of hemolysis can be numerically assessed for the optimal design, as hemolysis is an issue of overwhelming importance for blood pumps. PMID:26526039

  7. Computational Fluid Dynamics-Based Design Optimization Method for Archimedes Screw Blood Pumps.

    PubMed

    Yu, Hai; Janiga, Gábor; Thévenin, Dominique

    2016-04-01

    An optimization method suitable for improving the performance of Archimedes screw axial rotary blood pumps is described in the present article. In order to achieve a more robust design and to save computational resources, this method combines the advantages of the established pump design theory with modern computer-aided, computational fluid dynamics (CFD)-based design optimization (CFD-O) relying on evolutionary algorithms and computational fluid dynamics. The main purposes of this project are to: (i) integrate pump design theory within the already existing CFD-based optimization; (ii) demonstrate that the resulting procedure is suitable for optimizing an Archimedes screw blood pump in terms of efficiency. Results obtained in this study demonstrate that the developed tool is able to meet both objectives. Finally, the resulting level of hemolysis can be numerically assessed for the optimal design, as hemolysis is an issue of overwhelming importance for blood pumps.

  8. A sliding mode-based starling-like controller for implantable rotary blood pumps.

    PubMed

    Bakouri, Mohsen A; Salamonsen, Robert F; Savkin, Andrey V; AlOmari, Abdul-Hakeem H; Lim, Einly; Lovell, Nigel H

    2014-07-01

    Clinically adequate implementation of physiological control of a rotary left ventricular assist device requires a sophisticated technique such as the recently proposed method based on the Frank-Starling mechanism. In this mechanism, the stroke volume of the heart increases in response to an increase in the volume of blood filling the left ventricle at the end of diastole. To emulate this process, changes in pump speed need to automatically regulate pump flow to ensure that the combined output of the left ventricle and pump match the output of the right ventricle across changing cardiovascular states. In this approach, we exploit the linear relationship between estimated mean pump flow (Q ̅ est) and pump flow pulsatility (PIQp) in a tracking control algorithm based on sliding mode control. The immediate response of the controller was assessed using a lumped parameter model of the cardiovascular system (CVS) and pump from which could be extracted both Q ̅ est and PIQp. Two different perturbations from the resting state in the presence of left ventricular failure were tested. The first was blood loss requiring a reduction in pump flow to match the reduced output from the right ventricle and to avoid the complication of ventricular suction. The second was exercise, requiring an increase in pump flow. The sliding mode controller induced the required changes in Qp within approximately five heart beats in the blood loss simulation and eight heart beats in the exercise simulation without clinically significant transients or steady-state errors.

  9. Selective detection of sub-atto-molar Streptavidin in 10(13)-fold impure sample using photonic crystal nanolaser sensors.

    PubMed

    Hachuda, Shoji; Otsuka, Shota; Kita, Shota; Isono, Toshinari; Narimatsu, Michimasa; Watanabe, Keisuke; Goshima, Yoshio; Baba, Toshihiko

    2013-05-20

    Biosensors selectively detecting a very small amount of biomarker protein in human blood are desired for early and reliable diagnoses of severe diseases. This paper reports the detection of protein (streptavidin: SA) in ultra-low concentration, with an ultra-high selectivity against contaminants, using photonic crystal nanolasers. For biotin-modified nanolasers in pure water with SA, an extremely-low detection limit of 16 zM is evaluated. Even in a mixture with 1 μM bovine serum albumin as the contaminant, 100 zM SA is detected, meaning a selectivity of 10(13). These are remarkable capabilities that are promising for practical biosensing in the medical applications mentioned above.

  10. Auto-control of pumping operations in sewerage systems by rule-based fuzzy neural networks

    NASA Astrophysics Data System (ADS)

    Chiang, Y.-M.; Chang, L.-C.; Tsai, M.-J.; Wang, Y.-F.; Chang, F.-J.

    2011-01-01

    Pumping stations play an important role in flood mitigation in metropolitan areas. The existing sewerage systems, however, are facing a great challenge of fast rising peak flow resulting from urbanization and climate change. It is imperative to construct an efficient and accurate operating prediction model for pumping stations to simulate the drainage mechanism for discharging the rainwater in advance. In this study, we propose two rule-based fuzzy neural networks, adaptive neuro-fuzzy inference system (ANFIS) and counterpropagation fuzzy neural network for on-line predicting of the number of open and closed pumps of a pivotal pumping station in Taipei city up to a lead time of 20 min. The performance of ANFIS outperforms that of CFNN in terms of model efficiency, accuracy, and correctness. Furthermore, the results not only show the predictive water levels do contribute to the successfully operating pumping stations but also demonstrate the applicability and reliability of ANFIS in automatically controlling the urban sewerage systems.

  11. Auto-control of pumping operations in sewerage systems by rule-based fuzzy neural networks

    NASA Astrophysics Data System (ADS)

    Chiang, Y.-M.; Chang, L.-C.; Tsai, M.-J.; Wang, Y.-F.; Chang, F.-J.

    2010-09-01

    Pumping stations play an important role in flood mitigation in metropolitan areas. The existing sewerage systems, however, are facing a great challenge of fast rising peak flow resulting from urbanization and climate change. It is imperative to construct an efficient and accurate operating prediction model for pumping stations to simulate the drainage mechanism for discharging the rainwater in advance. In this study, we propose two rule-based fuzzy neural networks, adaptive neuro-fuzzy inference system (ANFIS) and counterpropagatiom fuzzy neural network (CFNN) for on-line predicting of the number of open and closed pumps of a pivotal pumping station in Taipei city up to a lead time of 20 min. The performance of ANFIS outperforms that of CFNN in terms of model efficiency, accuracy, and correctness. Furthermore, the results not only show the predictive water levels do contribute to the successfully operating pumping stations but also demonstrate the applicability and reliability of ANFIS in automatically controlling the urban sewerage systems.

  12. A Relevance Vector Machine-Based Approach with Application to Oil Sand Pump Prognostics

    PubMed Central

    Hu, Jinfei; Tse, Peter W.

    2013-01-01

    Oil sand pumps are widely used in the mining industry for the delivery of mixtures of abrasive solids and liquids. Because they operate under highly adverse conditions, these pumps usually experience significant wear. Consequently, equipment owners are quite often forced to invest substantially in system maintenance to avoid unscheduled downtime. In this study, an approach combining relevance vector machines (RVMs) with a sum of two exponential functions was developed to predict the remaining useful life (RUL) of field pump impellers. To handle field vibration data, a novel feature extracting process was proposed to arrive at a feature varying with the development of damage in the pump impellers. A case study involving two field datasets demonstrated the effectiveness of the developed method. Compared with standalone exponential fitting, the proposed RVM-based model was much better able to predict the remaining useful life of pump impellers. PMID:24051527

  13. Jet pumps for thermoacoustic applications: Design guidelines based on a numerical parameter study.

    PubMed

    Oosterhuis, Joris P; Bühler, Simon; Wilcox, Douglas; van der Meer, Theo H

    2015-10-01

    The oscillatory flow through tapered cylindrical tube sections (jet pumps) is characterized by a numerical parameter study. The shape of a jet pump results in asymmetric hydrodynamic end effects which cause a time-averaged pressure drop to occur under oscillatory flow conditions. Hence, jet pumps are used as streaming suppressors in closed-loop thermoacoustic devices. A two-dimensional axisymmetric computational fluid dynamics model is used to calculate the performance of a large number of conical jet pump geometries in terms of time-averaged pressure drop and acoustic power dissipation. The investigated geometrical parameters include the jet pump length, taper angle, waist diameter, and waist curvature. In correspondence with previous work, four flow regimes are observed which characterize the jet pump performance and dimensionless parameters are introduced to scale the performance of the various jet pump geometries. The simulation results are compared to an existing quasi-steady theory and it is shown that this theory is only applicable in a small operation region. Based on the scaling parameters, an optimum operation region is defined and design guidelines are proposed which can be directly used for future jet pump design. PMID:26520283

  14. Studies of cryocooler based cryosorption pump with activated carbon panels operating at 11K

    NASA Astrophysics Data System (ADS)

    Kasthurirengan, S.; Behera, Upendra; Gangradey, Ranjana; Udgata, Swarup; Krishnamoorthy, V.

    2012-11-01

    Cryosorption pump is the only solution for pumping helium and hydrogen in fusion reactors. It is chosen because it offers highest pumping speed as well as the only suitable pump for the harsh environments in a tokamak. Towards the development of such cryosorption pumps, the optimal choice of the right activated carbon panels is essential. In order to characterize the performance of the panels with indigenously developed activated carbon, a cryocooler based cryosorption pump with scaled down sizes of panels is experimented. The results are compared with the commercial cryopanel used in a CTI cryosorption (model: Cryotorr 7) pump. The cryopanel is mounted on the cold head of the second stage GM cryocooler which cools the cryopanel down to 11K with first stage reaching about ~50K. With no heat load, cryopump gives the ultimate vacuum of 2.1E-7 mbar. The pumping speed of different gases such as nitrogen, argon, hydrogen, helium are tested both on indigenous and commercial cryopanel. These studies serve as a bench mark towards the development of better cryopanels to be cooled by liquid helium for use with tokamak.

  15. Jet pumps for thermoacoustic applications: Design guidelines based on a numerical parameter study

    NASA Astrophysics Data System (ADS)

    Oosterhuis, Joris P.; Bühler, Simon; Wilcox, Douglas; van der Meer, Theo H.

    2015-10-01

    The oscillatory flow through tapered cylindrical tube sections (jet pumps) is characterized by a numerical parameter study. The shape of a jet pump results in asymmetric hydrodynamic end effects which cause a time-averaged pressure drop to occur under oscillatory flow conditions. Hence, jet pumps are used as streaming suppressors in closed-loop thermoacoustic devices. A two-dimensional axisymmetric computational fluid dynamics model is used to calculate the performance of a large number of conical jet pump geometries in terms of time-averaged pressure drop and acoustic power dissipation. The investigated geometrical parameters include the jet pump length, taper angle, waist diameter and waist curvature. In correspondence with previous work, four flow regimes are observed which characterize the jet pump performance and dimensionless parameters are introduced to scale the performance of the various jet pump geometries. The simulation results are compared to an existing quasi-steady theory and it is shown that this theory is only applicable in a small operation region. Based on the scaling parameters, an optimum operation region is defined and design guidelines are proposed which can be directly used for future jet pump design.

  16. In vivo assessment of a new method of pulsatile perfusion based on a centrifugal pump.

    PubMed

    Herreros, Jesús; Ubilla, Matías; Berjano, Enrique J; Vila-Nuñez, Juan E; Páramo, José A; Sola, Josu; Mercé, Salvador

    2010-02-01

    The aim of this study was to assess platelet dysfunction and damage to organs after extracorporeal circulation using a pump based on a new method that adds a pulsatile flow to the continuous flow provided by a centrifugal pump. The continuous component of the total flow (2-3 L/min) is created by a Bio-Pump centrifugal pump, while the pulsatile component is created by the pulsating of an inner membrane pneumatically controlled by an intra-aortic counterpulsation balloon console (systolic volume of 37.5 mL in an asynchronous way with a frequency of 60 bpm). Six pigs were subjected to a partial cardiopulmonary bypass lasting 180 min and were sacrificed 60 min after extracorporeal circulation was suspended. The hematological study included the measurement of hematocrit, hemoglobin, leukocytes, and platelet function. The new pump did not significantly alter either platelet count or platelet function. In contrast, hematocrit and hemoglobin were significantly reduced during extracorporeal circulation (approximately 5% P = 0.011, and 2 g/dL P = 0.01, respectively). The leukocyte count during extracorporeal circulation showed a tendency to decrease, but this was not significant. In general, the short-term use of the new pump (4 h) did not cause any serious morphological damage to the heart, lung, kidney, or liver. The results suggest that the hemodynamic performance of the new pump is similar to a conventional centrifugal pump and could therefore be appropriate for use in extracorporeal circulation.

  17. Growth of GaN micro/nanolaser arrays by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Liu, Haitao; Zhang, Hanlu; Dong, Lin; Zhang, Yingjiu; Pan, Caofeng

    2016-09-01

    Optically pumped ultraviolet lasing at room temperature based on GaN microwire arrays with Fabry–Perot cavities is demonstrated. GaN microwires have been grown perpendicularly on c-GaN/sapphire substrates through simple catalyst-free chemical vapor deposition. The GaN microwires are [0001] oriented single-crystal structures with hexagonal cross sections, each with a diameter of ∼1 μm and a length of ∼15 μm. A possible growth mechanism of the vertical GaN microwire arrays is proposed. Furthermore, we report room-temperature lasing in optically pumped GaN microwire arrays based on the Fabry–Perot cavity. Photoluminescence spectra exhibit lasing typically at 372 nm with an excitation threshold of 410 kW cm‑2. The result indicates that these aligned GaN microwire arrays may offer promising prospects for ultraviolet-emitting micro/nanodevices.

  18. Growth of GaN micro/nanolaser arrays by chemical vapor deposition.

    PubMed

    Liu, Haitao; Zhang, Hanlu; Dong, Lin; Zhang, Yingjiu; Pan, Caofeng

    2016-09-01

    Optically pumped ultraviolet lasing at room temperature based on GaN microwire arrays with Fabry-Perot cavities is demonstrated. GaN microwires have been grown perpendicularly on c-GaN/sapphire substrates through simple catalyst-free chemical vapor deposition. The GaN microwires are [0001] oriented single-crystal structures with hexagonal cross sections, each with a diameter of ∼1 μm and a length of ∼15 μm. A possible growth mechanism of the vertical GaN microwire arrays is proposed. Furthermore, we report room-temperature lasing in optically pumped GaN microwire arrays based on the Fabry-Perot cavity. Photoluminescence spectra exhibit lasing typically at 372 nm with an excitation threshold of 410 kW cm(-2). The result indicates that these aligned GaN microwire arrays may offer promising prospects for ultraviolet-emitting micro/nanodevices.

  19. Growth of GaN micro/nanolaser arrays by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Liu, Haitao; Zhang, Hanlu; Dong, Lin; Zhang, Yingjiu; Pan, Caofeng

    2016-09-01

    Optically pumped ultraviolet lasing at room temperature based on GaN microwire arrays with Fabry-Perot cavities is demonstrated. GaN microwires have been grown perpendicularly on c-GaN/sapphire substrates through simple catalyst-free chemical vapor deposition. The GaN microwires are [0001] oriented single-crystal structures with hexagonal cross sections, each with a diameter of ˜1 μm and a length of ˜15 μm. A possible growth mechanism of the vertical GaN microwire arrays is proposed. Furthermore, we report room-temperature lasing in optically pumped GaN microwire arrays based on the Fabry-Perot cavity. Photoluminescence spectra exhibit lasing typically at 372 nm with an excitation threshold of 410 kW cm-2. The result indicates that these aligned GaN microwire arrays may offer promising prospects for ultraviolet-emitting micro/nanodevices.

  20. Pump dependence of the dynamics of quantum dot based waveguide absorbers

    NASA Astrophysics Data System (ADS)

    Viktorov, Evgeny A.; Erneux, Thomas; Piwonski, Tomasz; Pulka, Jaroslaw; Huyet, Guillaume; Houlihan, John

    2012-06-01

    The nonlinear two stage recovery of quantum dot based reverse-biased waveguide absorbers is investigated experimentally and analytically as a function of the initial ground state occupation probability of the dot. The latter is controlled experimentally by the pump pulse power. The slow stage of the recovery is exponential and its basic timescale is independent of pump power. The fast stage of the recovery is a logistic function which we analyze in detail. The relative strength of slow to fast components is highlighted and the importance of higher order absorption processes at the highest pump level is demonstrated.

  1. Chemical-contrast imaging with pulse-shaping based pump-probe spectroscopy

    NASA Astrophysics Data System (ADS)

    Flynn, Daniel C.; Bhagwat, Amar R.; Ogilvie, Jennifer P.

    2013-02-01

    Ultrafast pump-probe spectroscopy and pulse-shaping techniques are providing new modes of contrast for the field of multiphoton microscopy. Endogenous species such as heme proteins show rich nonlinear spectroscopic signatures of excited state absorption, stimulated emission and ground-state bleaching. Commercially available octave-spanning Ti:sapphire oscillators offer new opportunities for imaging based on pump-probe contrast. Spatial light modulators take advantage of this large bandwidth, shaping pulses of light to selectively excite molecular structures with similar spectral properties. We present two-color pump-probe imaging of heme proteins solutions and red blood cells.

  2. An opto-isolator based linearization technique of a typical thyristor driven pump.

    PubMed

    Bera, S C; Sarkar, R; Mandal, N

    2012-01-01

    A thyristor driven pump is operated by varying the DC input signal in the firing circuit of thyristor drive. This operation suffers from difficulties due to the nonlinear relation between thyristor output and DC input. In the present paper, an opto-isolator based linearization technique of a typical thyristor driven pump has been proposed. The design, fabrication and the necessary circuit diagram along with theoretical explanations of the resultant output has been described. The operation of the linearized thyristor driven pump has been studied experimentally and the experimental data before and after linearization are reported. The characteristic graphs are found to have very good linearity.

  3. Modeling of a Membrane-Based Absorption Heat Pump

    SciTech Connect

    Woods, J.; Pellegrino, J.; Kozubal, E.; Slayzak, S.; Burch, J.

    2009-01-01

    In this paper, a membrane heat pump is proposed and analyzed. Fundamentally, the proposed heat pump consists of an aqueous CaCl{sub 2} solution flow separated from a water flow by a vapor-permeable membrane. The low activity of the solution results in a net flux of water vapor across the membrane, which heats the solution stream and cools the water stream. This mechanism upgrades water-side low-temperature heat to solution-side high-temperature heat, creating a 'temperature lift.' The modeling results show that using two membranes and an air gap instead of a single membrane increases the temperature lift by 185%. The model predicts temperature lifts for the air-gap design of 24, 16, and 6 C for inlet temperatures of 55, 35, and 15 C, respectively. Membranes with lower thermal conductivities and higher porosities improve the performance of single-membrane designs while thinner membranes improve the performance of air-gap designs. This device can be used with a solar heating system which already uses concentrated salt solutions for liquid-desiccant cooling.

  4. Improvement of photovoltaic pumping systems based on standard frequency converters by means of programmable logic controllers

    SciTech Connect

    Fernandez-Ramos, Jose; Narvarte-Fernandez, Luis; Poza-Saura, Fernando

    2010-01-15

    Photovoltaic pumping systems (PVPS) based on standard frequency converters (SFCs) are currently experiencing a growing interest in pumping programmes implemented in remote areas because of their high performance in terms of component reliability, low cost, high power range and good availability of components virtually anywhere in the world. However, in practical applications there have appeared a number of problems related to the adaptation of the SFCs to the requirements of the photovoltaic pumping systems (PVPS). Another disadvantage of dedicated PVPS is the difficulty in implementing maximum power point tracking (MPPT). This paper shows that these problems can be solved through the addition of a basic industrial programmable logic controller (PLC) to the system. This PLC does not increase the cost and complexity of the system, but improves the adaptation of the SFC to the photovoltaic pumping system, and increases the overall performance of the system. (author)

  5. Monolithic III-V on Silicon Plasmonic Nanolaser Structure for Optical Interconnects

    NASA Astrophysics Data System (ADS)

    Li, Ning; Liu, Ke; Sorger, Volker J.; Sadana, Devendra K.

    2015-09-01

    Monolithic integration of III-V semiconductor lasers with Si circuits can reduce cost and enhance performance for optical interconnects dramatically. We propose and investigate plasmonic III-V nanolasers as monolithically integrated light source on Si chips due to many advantages. First, these III-V plasmonic light sources can be directly grown on Si substrates free of crystallographic defects due to the submicron cavity footprint (250 nm × 250 nm) being smaller than the average defect free region size of the heteroepitaxial III-V material on Si. Secondly, the small lateral and vertical dimensions facilitate process co-integration with Si complementary metal-oxide-semiconductor (CMOS) in the front end of the line. Thirdly, combining with monolithically integrated CMOS circuits with low device capacitance and parasitic capacitance, the nano-cavity optoelectronic devices consume orders of magnitude less power than the conventional lasers and reduce the energy consumption. Fourthly, the modulation bandwidth of the plasmonic light-sources is enhanced to significantly higher than conventional lasers due to enhanced photon state density and transition rate. In addition, we show that these device performance are very robust after taking into account the surface recombination and variations in device fabrication processes.

  6. Monolithic III–V on Silicon Plasmonic Nanolaser Structure for Optical Interconnects

    PubMed Central

    Li, Ning; Liu, Ke; Sorger, Volker J.; Sadana, Devendra K.

    2015-01-01

    Monolithic integration of III–V semiconductor lasers with Si circuits can reduce cost and enhance performance for optical interconnects dramatically. We propose and investigate plasmonic III–V nanolasers as monolithically integrated light source on Si chips due to many advantages. First, these III–V plasmonic light sources can be directly grown on Si substrates free of crystallographic defects due to the submicron cavity footprint (250 nm × 250 nm) being smaller than the average defect free region size of the heteroepitaxial III–V material on Si. Secondly, the small lateral and vertical dimensions facilitate process co-integration with Si complementary metal-oxide-semiconductor (CMOS) in the front end of the line. Thirdly, combining with monolithically integrated CMOS circuits with low device capacitance and parasitic capacitance, the nano-cavity optoelectronic devices consume orders of magnitude less power than the conventional lasers and reduce the energy consumption. Fourthly, the modulation bandwidth of the plasmonic light-sources is enhanced to significantly higher than conventional lasers due to enhanced photon state density and transition rate. In addition, we show that these device performance are very robust after taking into account the surface recombination and variations in device fabrication processes. PMID:26369698

  7. Condition Based vs. Time Based Maintenance: Case Study on Hypergolic Pumps

    NASA Technical Reports Server (NTRS)

    Gibson, Lewis J.

    2007-01-01

    Two Pad 39B Ox pumps were monitored with the Baker Instruments Explorer Motor tester. Using the torque spectrum it was determined that Ox pump #2 had a significant peak at a frequency, which indicated lubricant fluid whirl. Similar testing on Ox pump #1 didn't indicate this peak, an indication that this pump was in good mechanical condition. Subsequent disassembly of both motors validated these findings. Ox pump #2 rear bearing showed significant wear, the front bearing showed little wear. Ox pump #1 was still within manufacturers tolerances.

  8. A Subfemtotesla Atomic Magnetometer Based on Hybrid Optical Pumping of Potassium and Rubidium

    NASA Astrophysics Data System (ADS)

    Li, Yang; Cai, Hongwei; Ding, Ming; Quan, Wei; Fang, Jiancheng

    2016-05-01

    Atomic magnetometers, based on detection of Larmor spin precession of optically pumped atoms, have been researched and applied extensively. Higher sensitivity and spatial resolution combined with no cryogenic cooling of atomic magnetometers would enable many applications with low cost, including the magnetoencephalography (MEG). Ultrahigh sensitivity atomic magnetometer is considered to be the main development direction for the future. Hybrid optical pumping has been proposed to improve the efficiency of nuclear polarization. But it can also be used for magnetic field measurement. This method can control absorption of optical pumping light, which is benefit for improving the uniformity of alkali metal atoms polarization and the sensitivity of atomic magnetometer. In addition, it allows optical pumping in the absence of quenching gas. We conduct experiments with a hybrid optically pumped atomic magnetometer using a cell containing potassium and rubidium. By adjusting the density ratio of alkali metal and the pumping laser conditions, we measured the magnetic field sensitivity better than 0.7 fT/sqrt(Hz).

  9. Recursive pump-adding scheme for optical superchannel multicasting based on FWM

    NASA Astrophysics Data System (ADS)

    Zhu, Paikun; Li, Juhao; Wu, Zhongying; Chen, Xin; Xu, Yingying; Lin, Bangjiang; Chen, Zhangyuan; He, Yongqi

    2015-07-01

    Optical superchannel multicasting, whereby a superchannel is replicated simultaneously to multiple spectral locations in a single device, is potentially a promising functionality for future optical networks. Multiple-pump four-wave mixing (FWM) in highly nonlinear fiber (HNLF) is an effective approach to implement superchannel multicasting. However, if the frequencies of the pumps are not carefully configured, the generated replicas would be spectrally scattered, which would increase the difficulty of controlling replicas' performance and managing spectral resource. In this paper, we propose a recursive pump-adding (RPA) scheme, which makes the replicas more spectrally aggregated than our previous exponentially-growing-spaced (EGS) pump scheme. Such replica aggregation technique can reduce phase mismatching of replicas remote from the original channel, which is beneficial to replicas' performance. RPA scheme also provides an additional option of replica allocation for multicasting. Based on the RPA scheme, we have experimentally demonstrated 1-to-21 superchannel multicasting with 5 pumps. More than 2.3 dB Q-factor margin is achieved across all the replicas compared with the typical 7% forward error correction (FEC) threshold. The performance comparison between RPA and EGS pump scheme is also investigated.

  10. An accurate single-electron pump based on a highly tunable silicon quantum dot.

    PubMed

    Rossi, Alessandro; Tanttu, Tuomo; Tan, Kuan Yen; Iisakka, Ilkka; Zhao, Ruichen; Chan, Kok Wai; Tettamanzi, Giuseppe C; Rogge, Sven; Dzurak, Andrew S; Möttönen, Mikko

    2014-06-11

    Nanoscale single-electron pumps can be used to generate accurate currents, and can potentially serve to realize a new standard of electrical current based on elementary charge. Here, we use a silicon-based quantum dot with tunable tunnel barriers as an accurate source of quantized current. The charge transfer accuracy of our pump can be dramatically enhanced by controlling the electrostatic confinement of the dot using purposely engineered gate electrodes. Improvements in the operational robustness, as well as suppression of nonadiabatic transitions that reduce pumping accuracy, are achieved via small adjustments of the gate voltages. We can produce an output current in excess of 80 pA with experimentally determined relative uncertainty below 50 parts per million.

  11. Cavity-free stopped-light nanolasing in nanoplasmonic heterostructures (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Hess, Ortwin

    2015-09-01

    Going beyond traditional cavity-concepts, recently conceived nanolasers employ plasmonic resonances for feedback, allowing them to concentrate light into mode volumes that are no longer limited by diffraction [1]. The use of localized surface plasmon resonances as cold-cavity modes, however, is only one route to lasing on subwavelength scales. Lasing, in fact, does not require modes predefined by geometry but merely a feedback mechanism [2]. Here we demonstrate that the concept of dispersion-less stopped-light [3] allows by combination of nanoplasmonics with quantum gain materials [4] stopped-light lasing in hybrid nanoplasmonic heterostructures. Thereby, photons are trapped and amplified in space just at the point of their emission. It will be discussed that, at the stopped-light point, a stable lasing mode can form over a finite region of gain material due to the arising local (cavity-free) feedback in the form of a sub-wavelength optical vortex. We discuss the remarkable spatio-temporal dynamics of nanoplasmonic stopped-light lasing is studied on the basis of a Maxwell-Bloch Langevin approach [4]. Moreover, a new rate-equation framework is shown to grasp the particular physics of stopped-light lasing involving [4]. The observed high-β characteristics and picosecond relaxation oscillations of cavity-free stopped-light lasing can potentially allow for the design of thresholdless plasmonic laser diodes that can be modulated with THz speeds. References [1] O Hess and KL Tsakmakidis, Science 339, 654 (2013). [2] J M Hamm and O Hess, Science 340, 1298 (2013). [3] KL Tsakmakidis, TW Pickering, JM Hamm, AF Page and O Hess, Phys Rev Lett 112, 167401 (2014). [4] T Pickering, J M Hamm, A F Page, S Wuestner and O Hess, Nature Communications 5, 4971 (2014).

  12. Wireless implantable chip with integrated nitinol-based pump for radio-controlled local drug delivery.

    PubMed

    Fong, Jeffrey; Xiao, Zhiming; Takahata, Kenichi

    2015-02-21

    We demonstrate an active, implantable drug delivery device embedded with a microfluidic pump that is driven by a radio-controlled actuator for temporal drug delivery. The polyimide-packaged 10 × 10 × 2 mm(3) chip contains a micromachined pump chamber and check valves of Parylene C to force the release of the drug from a 76 μL reservoir by wirelessly activating the actuator using external radio-frequency (RF) electromagnetic fields. The rectangular-shaped spiral-coil actuator based on nitinol, a biocompatible shape-memory alloy, is developed to perform cantilever-like actuation for pumping operation. The nitinol-coil actuator itself forms a passive 185 MHz resonant circuit that serves as a self-heat source activated via RF power transfer to enable frequency-selective actuation and pumping. Experimental wireless operation of fabricated prototypes shows successful release of test agents from the devices placed in liquid and excited by radiating tuned RF fields with an output power of 1.1 W. These tests reveal a single release volume of 219 nL, suggesting a device's capacity of ~350 individual ejections of drug from its reservoir. The thermal behavior of the activated device is also reported in detail. This proof-of-concept prototype validates the effectiveness of wireless RF pumping for fully controlled, long-lasting drug delivery, a key step towards enabling patient-tailored, targeted local drug delivery through highly miniaturized implants. PMID:25473933

  13. Wireless implantable chip with integrated nitinol-based pump for radio-controlled local drug delivery.

    PubMed

    Fong, Jeffrey; Xiao, Zhiming; Takahata, Kenichi

    2015-02-21

    We demonstrate an active, implantable drug delivery device embedded with a microfluidic pump that is driven by a radio-controlled actuator for temporal drug delivery. The polyimide-packaged 10 × 10 × 2 mm(3) chip contains a micromachined pump chamber and check valves of Parylene C to force the release of the drug from a 76 μL reservoir by wirelessly activating the actuator using external radio-frequency (RF) electromagnetic fields. The rectangular-shaped spiral-coil actuator based on nitinol, a biocompatible shape-memory alloy, is developed to perform cantilever-like actuation for pumping operation. The nitinol-coil actuator itself forms a passive 185 MHz resonant circuit that serves as a self-heat source activated via RF power transfer to enable frequency-selective actuation and pumping. Experimental wireless operation of fabricated prototypes shows successful release of test agents from the devices placed in liquid and excited by radiating tuned RF fields with an output power of 1.1 W. These tests reveal a single release volume of 219 nL, suggesting a device's capacity of ~350 individual ejections of drug from its reservoir. The thermal behavior of the activated device is also reported in detail. This proof-of-concept prototype validates the effectiveness of wireless RF pumping for fully controlled, long-lasting drug delivery, a key step towards enabling patient-tailored, targeted local drug delivery through highly miniaturized implants.

  14. Experimental performance evaluation of heat pump-based steam supply system

    NASA Astrophysics Data System (ADS)

    Kaida, T.; Sakuraba, I.; Hashimoto, K.; Hasegawa, H.

    2015-08-01

    Heat pumps have become increasingly important as a technology to reduce primary energy consumption and greenhouse effect gas emission. They are presently used mainly on residential air-conditioning and domestic hot water and are expected to spread to industrial heating processes. In 2011, Kobe Steel, Ltd. developed and commercialized two heat pump- based steam supply systems; the high efficiency steam supply system with a steam temperature of 120°C (SGH120) and the system which enables a steam temperature of 165°C (sGh165). For promoting the spread of these industrial heat pumps and enhancing the reliability of them, we investigate experimentally steam generation rate, energy efficiency and controlled performance of the SGH165 under various operating conditions on the assumption of actual different industrial processes, and evaluate technical possibilities for better performance.

  15. Active radiation hardening of Tm-doped silica fiber based on pump bleaching.

    PubMed

    Xing, Ying-bin; Zhao, Nan; Liao, Lei; Wang, Yi-bo; Li, Hai-qing; Peng, Jing-gang; Yang, Lv-yun; Dai, Neng-li; Li, Jin-yan

    2015-09-21

    Tm-doped fiber laser or amplifier can be applied in varied adverse environments. In this work, we demonstrate the pump bleaching of Tm-doped silica fiber with 793nm pump source under gamma-ray irradiation in the range 50Gy-675Gy. The recovery time, the fiber slope efficiency and the fiber cladding absorption spectra after irradiation and bleaching have been measured. It is found that the recovery time and radiation induce absorption are positively associated with doses, however, the fiber slope efficiency of irradiated TDF and bleached TDF are both negatively correlated with doses. Based on the simulation of the fiber core temperature, the probable mechanism of pump bleaching is also discussed.

  16. Micro pumping methods based on AC electrokinetics and Electrorheologically actuated PDMS valves

    NASA Astrophysics Data System (ADS)

    Soni, Gaurav; Squires, Todd; Meinhart, Carl

    2006-11-01

    We have developed 2 different micropumping methods for transporting ionic fluids through microchannels. The first method is based on Induced Charge Electroosmosis (ICEO) and AC flow field-effect. We used an AC electric field to produce a symmetric ICEO flow on a planar electrode, called `gate'. In order to break the symmetry of ICEO, we applied an additional AC voltage to the gate electrode. Such modulation of the gate potential is called field effect and produces a unidirectional pumping over the gate surface. We used micro PIV to measure pumping velocities for a range of ionic concentration, AC frequency and gate voltage. We have also conducted numerical simulations to understand the deteriorating effect of lateral conduction of surface charge on the pumping velocities. The second method is based on vibration of a flexible PDMS diaphragm actuated by an electrorheological (ER) fluid. ER fluid is a colloidal suspension exhibiting a reversible liquid-to-solid transition under an electric field. This liquid-to-solid transition can yield very high shear stress and can be used to open and close a PDMS valve. Three such valves were fabricated and actuated in a peristaltic fashion in order to achieve positive displacement pumping of fluids.

  17. Hydration induced material transfer in membranes of osmotic pump tablets measured by synchrotron radiation based FTIR.

    PubMed

    Wu, Li; Yin, Xianzhen; Guo, Zhen; Tong, Yajun; Feng, Jing; York, Peter; Xiao, Tiqiao; Chen, Min; Gu, Jingkai; Zhang, Jiwen

    2016-03-10

    Osmotic pump tablets are reliable oral controlled drug delivery systems based on their semipermeable membrane coating. This research used synchrotron radiation-based Fourier transform infrared (SR-FTIR) microspectroscopy and imaging to investigate the hydration induced material transfer in the membranes of osmotic pump tablets. SR-FTIR was applied to record and map the chemical information of a micro-region of the membranes, composed of cellulose acetate (CA, as the water insoluble matrix) and polyethylene glycol (PEG, as the soluble pore forming agent and plasticizing agent). The microstructure and chemical change of membranes hydrated for 0, 5, 10 and 30min were measured using SR-FTIR, combined with scanning electronic microscopy and atom force microscopy. The SR-FTIR microspectroscopy results indicated that there was a major change at the absorption range of 2700-3100cm(-1) in the membranes after different periods of hydration time. The absorption bands at 2870-2880cm(-1) and 2950-2960cm(-1) were assigned to represent CA and PEG, respectively. The chemical group signal distribution illustrated by the ratio of PEG to CA demonstrated that the trigger of drug release in the preliminary stage was due to the rapid transfer of PEG into liquid medium with a sharp decrease of PEG in the membranes. The SR-FTIR mapping results have demonstrated the hydration induced material transfer in the membranes of osmotic pump tablets and enabled reassessment of the drug release mechanism of membrane controlled osmotic pump systems. PMID:26802550

  18. Hydration induced material transfer in membranes of osmotic pump tablets measured by synchrotron radiation based FTIR.

    PubMed

    Wu, Li; Yin, Xianzhen; Guo, Zhen; Tong, Yajun; Feng, Jing; York, Peter; Xiao, Tiqiao; Chen, Min; Gu, Jingkai; Zhang, Jiwen

    2016-03-10

    Osmotic pump tablets are reliable oral controlled drug delivery systems based on their semipermeable membrane coating. This research used synchrotron radiation-based Fourier transform infrared (SR-FTIR) microspectroscopy and imaging to investigate the hydration induced material transfer in the membranes of osmotic pump tablets. SR-FTIR was applied to record and map the chemical information of a micro-region of the membranes, composed of cellulose acetate (CA, as the water insoluble matrix) and polyethylene glycol (PEG, as the soluble pore forming agent and plasticizing agent). The microstructure and chemical change of membranes hydrated for 0, 5, 10 and 30min were measured using SR-FTIR, combined with scanning electronic microscopy and atom force microscopy. The SR-FTIR microspectroscopy results indicated that there was a major change at the absorption range of 2700-3100cm(-1) in the membranes after different periods of hydration time. The absorption bands at 2870-2880cm(-1) and 2950-2960cm(-1) were assigned to represent CA and PEG, respectively. The chemical group signal distribution illustrated by the ratio of PEG to CA demonstrated that the trigger of drug release in the preliminary stage was due to the rapid transfer of PEG into liquid medium with a sharp decrease of PEG in the membranes. The SR-FTIR mapping results have demonstrated the hydration induced material transfer in the membranes of osmotic pump tablets and enabled reassessment of the drug release mechanism of membrane controlled osmotic pump systems.

  19. Computation of stress distribution in a mixed flow pump based on fluid-structure interaction analysis

    NASA Astrophysics Data System (ADS)

    Hu, F. F.; Chen, T.; Wu, D. Z.; Wang, L. Q.

    2013-12-01

    The internal flow evolution of the pump was induced with impeller movement. In various conditions, the peak load on centrifugal blade under the change of rotational speed or flow rate was also changed. It would cause an error when inertia load with a safety coefficient (that was difficult to ascertain) was applied in structure design. In order to accurately analyze the impeller stress under various conditions and improve the reliability of pump, based on a mixed flow pump model, the stress distribution characteristic was analyzed under different flow rates and rotational speeds. Based on a three-dimensional calculation model including impeller, guide blade, inlet and outlet, the three-dimension incompressible turbulence flow in the centrifugal pump was simulated by using the standard k-epsilon turbulence model. Based on the sequentially coupled simulation approach, a three-dimensional finite element model of impeller was established, and the fluid-structure interaction method of the blade load transfer was discussed. The blades pressure from flow simulation, together with inertia force acting on the blade, was used as the blade loading on solid surface. The Finite Element Method (FEM) was used to calculate the stress distribution of the blade respectively under inertia load, or fluid load, or combined load. The results showed that the blade stress changed with flow rate and rotational speed. In all cases, the maximum stress on the blade appeared on the pressure side near the hub, and the maximum static stress increased with the decreasing of the flow rate and the increasing of rotational speed. There was a big difference on the static stress when inertia load, fluid load and combined loads was applied respectively. In order to more accurately calculate the stress distribution, the structure analysis should be conducted due to combined loads. The results could provide basis for the stress analysis and structure optimization of pump.

  20. Atomic-based stabilization for laser-pumped atomic clocks.

    PubMed

    Gerginov, V; Shah, V; Knappe, S; Hollberg, L; Kitching, J

    2006-06-15

    We describe a novel technique for stabilizing frequency shifts in laser-interrogated vapor-cell atomic clocks. The method suppresses frequency shifts due to changes in the laser frequency, intensity, and modulation index as well as atomic vapor density. The clock operating parameters are monitored by using the atoms themselves, rather than by using conventional schemes for laser frequency and cell temperature control. The experiment is realized using a chip-scale atomic clock. The novel atomic-based stabilization approach results in a simpler setup and improved long-term performance.

  1. Prognostic for hydraulic pump based upon DCT-composite spectrum and the modified echo state network.

    PubMed

    Sun, Jian; Li, Hongru; Xu, Baohua

    2016-01-01

    Prognostic is a key step of the condition-based maintenance (CBM). In order to improve the predicting performance, a novel method for prognostic for the hydraulic pump is proposed in this paper. Based on the improvement of the traditional composite spectrum, the DCT-composite spectrum (DCS) fusion algorithm is initially presented to make fusion of multi-channel vibration signals. The DCS composite spectrum entropy is extracted as the feature. Furthermore, the modified echo state networks (ESN) model is established for prognostic using the extracted feature. The reservoir is updated and the elements of the neighboring matrix are redefined for improving predicting accuracy. Analysis of the application in the hydraulic pump degradation experiment demonstrates that the proposed algorithm is feasible and is meaningful for CBM.

  2. Prognostic for hydraulic pump based upon DCT-composite spectrum and the modified echo state network.

    PubMed

    Sun, Jian; Li, Hongru; Xu, Baohua

    2016-01-01

    Prognostic is a key step of the condition-based maintenance (CBM). In order to improve the predicting performance, a novel method for prognostic for the hydraulic pump is proposed in this paper. Based on the improvement of the traditional composite spectrum, the DCT-composite spectrum (DCS) fusion algorithm is initially presented to make fusion of multi-channel vibration signals. The DCS composite spectrum entropy is extracted as the feature. Furthermore, the modified echo state networks (ESN) model is established for prognostic using the extracted feature. The reservoir is updated and the elements of the neighboring matrix are redefined for improving predicting accuracy. Analysis of the application in the hydraulic pump degradation experiment demonstrates that the proposed algorithm is feasible and is meaningful for CBM. PMID:27547667

  3. Use of insulin pumps in India: suggested guidelines based on experience and cultural differences.

    PubMed

    Kesavadev, Jothydev; Das, Ashok Kumar; Unnikrishnan, Ranjit; Joshi, Shashank R; Ramachandran, Ambady; Shamsudeen, Jisha; Krishnan, Gopika; Jothydev, Sunitha; Mohan, Viswanathan

    2010-10-01

    All type 1 diabetes mellitus (T1DM) subjects and the majority of type 2 diabetes mellitus (T2DM) subjects at one time or another require insulin to sustain life. Syringes and pens are presently the most popular insulin delivery devices. Though in use for more than 3 decades, insulin pumps are now being more commonly used because of their unique ability to continuously infuse insulin, closely mimicking that of physiological secretion from a normal pancreas. Unlike insulin shots with syringes, pump infusion sites need to be changed less frequently. Scientific evidence from published studies have proven added benefit of insulin pumps in improving quality of life, normalizing sugars in recalcitrant diabetes, improving sexual function, and relieving the intractable pain of neuropathy. In the western world, pumps are commonly used with T1DM subjects, whereas in India 80% of pumpers are T2DM subjects. The success of insulin pump therapy depends on selection of the right candidate, extensive education, motivation, and implementing the sophisticated programs with skill. However, all affordable patients are not ideal candidates for pump therapy because for successful continuation of pump therapy other inclusion criteria should also be fulfilled. Among the other indications discussed are a high level of insulin resistance, brittle diabetes, chronic kidney disease on renal replacement therapy, and continuous glucose monitoring pattern strongly suggesting need for a variable basal insulin infusion rate. In International Diabetes Foundation data released in 2009, estimated diabetes prevalence for 2010 is 285 million, representing 6.4% of the world's adult population, with a prediction that by 2030 the number of people with diabetes will have increased to 438 million. Considering this massive growth in T2DM and its propensity after 10–15 years to lead to an insulin-deficient state, available evidence from studies is a compelling indication not to deny the benefits of continuous

  4. Dynamic stress analysis of sewage centrifugal pump impeller based on two-way coupling method

    NASA Astrophysics Data System (ADS)

    Pei, Ji; Yuan, Shouqi; Yuan, Jianping

    2014-03-01

    Current research on the operational reliability of centrifugal pumps has mainly focused on hydrodynamic instability. However, the interaction between the fluid and structure has not been sufficiently considered; this interaction can cause vibration and dynamic stress, which can affect the reliability. In this study, the dynamic stresses in a single-blade centrifugal pump impeller are analysed under different operating conditions; the two-way coupling method is used to calculate the fluid-structure interaction. Three-dimensional unsteady Reynolds-averaged Navier-Stokes equations are solved with the SST k-ω turbulence model for the fluid in the whole flow passage, while transient structure dynamic analysis is used with the finite element method for the structure side. The dynamic stresses in the rotor system are computed according to the fourth strength theory. The stress results show that the highest stress is near the loose bearing and that the equivalent stress increases with the flow rate because the dynamic stresses are closely related to the pressure load. The stress distributions on the blade pressure side, suction side, leading edge, and trailing edge are each analysed for different flow rates; the highest stress distribution is found on the pressure side. On the blade pressure side, a relatively large stress is found near the trailing edge and hub side. Based on these results, a stress distribution prediction method is proposed for centrifugal pumps, which considers the interaction between the fluid and structure. The method can be used to check the dynamic stress at different flow rates when optimising the pump design to increase the pump reliability.

  5. A Pressure Control Method for Emulsion Pump Station Based on Elman Neural Network

    PubMed Central

    Tan, Chao; Qi, Nan; Yao, Xingang; Wang, Zhongbin; Si, Lei

    2015-01-01

    In order to realize pressure control of emulsion pump station which is key equipment of coal mine in the safety production, the control requirements were analyzed and a pressure control method based on Elman neural network was proposed. The key techniques such as system framework, pressure prediction model, pressure control model, and the flowchart of proposed approach were presented. Finally, a simulation example was carried out and comparison results indicated that the proposed approach was feasible and efficient and outperformed others. PMID:25861253

  6. A practical approach for implementing risk-based inservice testing of pumps at nuclear power plants

    SciTech Connect

    Hartley, R.S.; Maret, D.; Seniuk, P.; Smith, L.

    1996-12-01

    The American Society of Mechanical Engineers (ASME) Center for Research and Technology Development`s (CRTD) Research Task Force on Risk-Based Inservice Testing has developed guidelines for risk-based inservice testing (IST) of pumps and valves. These guidelines are intended to help the ASME Operation and Maintenance (OM) Committee to enhance plant safety while focussing appropriate testing resources on critical components. This paper describes a practical approach for implementing those guidelines for pumps at nuclear power plants. The approach, as described in this paper, relies on input, direction, and assistance from several entities such as the ASME Code Committees, United States Nuclear Regulatory Commission (NRC), and the National Laboratories, as well as industry groups and personnel with applicable expertise. Key parts of the risk-based IST process that are addressed here include: identification of important failure modes, identification of significant failure causes, assessing the effectiveness of testing and maintenance activities, development of alternative testing and maintenance strategies, and assessing the effectiveness of alternative testing strategies with present ASME Code requirements. Finally, the paper suggests a method of implementing this process into the ASME OM Code for pump testing.

  7. Electro-osmotic pumping and ion-concentration polarization based on conical nanopores

    NASA Astrophysics Data System (ADS)

    Yeh, Hung-Chun; Chang, Chih-Chang; Yang, Ruey-Jen

    2015-06-01

    A numerical investigation is performed into the characteristics of an electro-osmotic pump consisting of a negatively charged conical nanopore. It is shown that the dependence of the flow rectification effect on the bias direction is the reverse of that of the ion current rectification effect. Moreover, the nozzle mode (i.e., the bias is applied from the base side of the nanopore to the tip side) has a higher flow rate compared to the diffuser mode (i.e., the bias is applied from the tip side of the nanopore to the base side). The results showed that the ion-concentration polarization effect occurred inside the conical nanopore, resulting in surface conduction dominating in the ionic current. The ions inside the nanopore are depleted and enriched under the nozzle mode and the diffuser mode, respectively. As a result, the electro-osmotic pump yields a greater pumping pressure, flow rate, and energy conversion efficiency when operating in the nozzle mode. In addition, we also investigated the flow rate rectification behavior for the conical nanopore. The best flow rate rectification factor in this work is 2.06 for an electrolyte concentration of 10-3M .

  8. Thermodynamics of information processing based on enzyme kinetics: An exactly solvable model of an information pump

    NASA Astrophysics Data System (ADS)

    Cao, Yuansheng; Gong, Zongping; Quan, H. T.

    2015-06-01

    Motivated by the recent proposed models of the information engine [Proc. Natl. Acad. Sci. USA 109, 11641 (2012), 10.1073/pnas.1204263109] and the information refrigerator [Phys. Rev. Lett. 111, 030602 (2013), 10.1103/PhysRevLett.111.030602], we propose a minimal model of the information pump and the information eraser based on enzyme kinetics. This device can either pump molecules against the chemical potential gradient by consuming the information to be encoded in the bit stream or (partially) erase the information initially encoded in the bit stream by consuming the Gibbs free energy. The dynamics of this model is solved exactly, and the "phase diagram" of the operation regimes is determined. The efficiency and the power of the information machine is analyzed. The validity of the second law of thermodynamics within our model is clarified. Our model offers a simple paradigm for the investigating of the thermodynamics of information processing involving the chemical potential in small systems.

  9. 1.2-kW single-mode fiber laser based on 100-W high-brightness pump diodes

    NASA Astrophysics Data System (ADS)

    Yu, Hongbo; Kliner, Dahv A. V.; Liao, Kai-Hsiu; Segall, Jeff; Muendel, Martin H.; Morehead, James J.; Shen, Jane; Kutsuris, Matt; Luu, Johnny; Franke, Justin; Nguyen, Kelvin; Woods, Dave; Vance, Fred; Vecht, David; Meng, David; Duesterberg, Richard; Xu, Lei; Skidmore, Jay; Peters, Matthew; Guerin, Nicolas; Guo, James; Cheng, Jane; Du, Jihua; Johnson, Brad; Yin, Dongliang; Hsieh, Allen; Cheng, Peter; Demir, Abdullah; Cai, Jason; Gurram, Rupa; Lee, Kong-Weng; Raju, Reddy; Zou, Daniel; Srinivasan, Raman; Saini, Mandeep; Zavala, Laura; Rossin, Victor; Zucker, Erik P.; Ishiguro, Hiroaki; Sako, Hiroshi

    2012-02-01

    We have demonstrated a monolithic (fully fused), 1.2-kW, Yb-doped fiber laser with near-single-mode beam quality. This laser employs a new generation of high-brightness, fiber-coupled pump sources based on spatially multiplexed single emitters, with each pump providing 100 W at 915 nm within 0.15 NA from a standard 105/125 μm fiber. The fiber laser is end pumped through the high-reflector FBG using a 19:1 fused-fiber pump combiner, eliminating the need for pump/signal combiners. The output wavelength is 1080 nm, with a linewidth of < 0.5 nm FWHM. A peak power of 1.5 kW was reached in modulated operation (1-ms pulse duration) with M2 < 1.2.

  10. High-performance optically pumped GaSb-based semiconductor disk lasers for the 2.Xμm wavelength range

    NASA Astrophysics Data System (ADS)

    Rattunde, M.; Schulz, N.; Rösener, B.; Manz, C.; Köhler, K.; Wagner, J.; Hopkins, J.-M.; Burns, D.

    2008-02-01

    We report on recent advances in the performance of GaSb-based optically pumped semiconductor disk lasers (OPSDLs), emitting in the 2.0 - 2.3 μm wavelength range. Both barrier pumped OPSDL (using 980 nm laser diodes as pump source) and in-well pumped OPSDL (using 1.96 μm pump radiation) have been fabricated and characterized. Using alternative SiC or diamond intracavity heatspreader, multiple-watt CW-output powers have been achieved (e.g. >3W at 2.3 μm and >5W at 2.0 μm), with power efficiencies in the range of 18 % - 25 %. For an optimised resonator setup, the beam profile is close to the diffraction limit with M2 values around 1.2; and even for the highest power levels, M2 is in the range of 2-5.

  11. Electrically pumped random lasing based on an Au-ZnO nanowire Schottky junction.

    PubMed

    Gao, Fan; Morshed, Muhammad M; Bashar, Sunayna B; Zheng, Youdou; Shi, Yi; Liu, Jianlin

    2015-06-01

    Electrically pumped random lasing based on an Au-ZnO nanowire Schottky junction diode is demonstrated. The device exhibits typical Schottky diode current-voltage characteristics with a turn-on voltage of 0.7 V. Electroluminescence characterization shows good random lasing behavior and the output power is about 67 nW at a drive current of 100 mA. Excitonic recombination is responsible for lasing generation. Zn plasma is only observed under high applied bias, which can be distinguished from the random lasing spectral features near 380 nm. The laser diode based on the Schottky junction provides an alternative approach towards semiconductor random lasers. PMID:25946977

  12. Synchronously pumped picosecond all-fibre Raman laser based on phosphorus-doped silica fibre.

    PubMed

    Kobtsev, Sergey; Kukarin, Sergey; Kokhanovskiy, Alexey

    2015-07-13

    Reported for the first time is picosecond-range pulse generation in an all-fibre Raman laser based on P₂O₅-doped silica fibre. Employment of phosphor-silicate fibre made possible single-cascade spectral transformation of pumping pulses at 1084 nm into 270-ps long Raman laser pulses at 1270 nm. The highest observed fraction of the Stokes component radiation at 1270 nm in the total output of the Raman laser amounted to 30%. The identified optimal duration of the input pulses at which the amount of Stokes component radiation in a ~16-m long phosphorus-based Raman fibre converter reaches its maximum was 140-180 ps.

  13. Finite Volume Based Computer Program for Ground Source Heat Pump System

    SciTech Connect

    Menart, James A.

    2013-02-22

    This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled ?Finite Volume Based Computer Program for Ground Source Heat Pump Systems.? The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump

  14. Recovery Act: Finite Volume Based Computer Program for Ground Source Heat Pump Systems

    SciTech Connect

    James A Menart, Professor

    2013-02-22

    This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled Finite Volume Based Computer Program for Ground Source Heat Pump Systems. The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump. The

  15. An efficient 2-stage fractional charge pump based on frequency regulation

    NASA Astrophysics Data System (ADS)

    Saiz-Vela, A.; Miribel-Catala, P.; Puig-Vidal, M.; Samitier, J.

    2005-06-01

    An efficient 2-stage charge pump based on two-phase voltage doublers is proposed in this paper. Pulse skipping frequency regulators have been used to obtain a high efficiency over a wide range of loads. Since this charge pump has been designed for battery-powered portable devices, a power-up control system that combines a linear and a switched charging sequence has been included in each stage in order to avoid great current spikes at the beginning of the start-up process that could damage or shorten the battery life. The result is a power efficient 2-stage charge pump capable to generate a maximum regulated output voltage up to 10V from a 2.7V-3.3V battery source and deliver a maximum power of 100mW. If it is desired, the regulated output voltage can be downscaled to a required lower regulated voltage through a simple programming method using external resistors plus internal digital circuitry. This circuit has been designed using a 0.7μI2T technology from AMI semiconductor.

  16. Global design optimization for an axial-flow tandem pump based on surrogate method

    NASA Astrophysics Data System (ADS)

    Li, D. H.; Zhao, Y.; Y Wang, G.

    2013-12-01

    Tandem pump, compared with multistage pump, goes without guide vanes between impellers. Better cavitation performance and significant reduction of the axial geometry scale is important for high-speed propulsion. This study presents a global design optimization method based on surrogated method for an axial-flow tandem pump to enhance trade-off performances: energy and cavitation performances. At the same time, interactions between impellers and impacts on the performances are analyzed. Fixed angle of blades in impellers and phase angle are performed as design variables. Efficiency and minimum average pressure coefficient (MAPC) on axial sectional surface in front impeller are the objective function, which can represent energy and cavitation performances well. Different surrogate models are constructed, and Global Sensitivity Analysis and Pareto Front method are used. The results show that, 1) Influence from phase angle on performances can be neglected compared with other two design variables, 2) Impact ratio of fixed angle of blades in two impellers on efficiency are the same as their designed loading distributions, which is 4:6, 3) The optimization results can enhance the trade-off performances well: efficiency is improved by 0.6%, and the MAPC is improved by 4.5%.

  17. A microchip-based proteolytic digestion system driven by electroosmotic pumping.

    PubMed

    Jin, Lian Ji; Ferrance, Jerome; Sanders, Joshua C; Landers, James P

    2003-02-01

    Microchip-based proteomic analysis requires proteolytic digestion of proteins in microdevices. Enzyme reactors in microdevices, fabricated in glass, silicon, and PDMS substrates, have recently been demonstrated for model protein digestions. The common approach used for these enzyme reactors is employment of a syringe pump(s) to generate hydrodynamic flow, driving the proteins through the reactors. Here we present a novel approach, using electroosmotic flow (EOF) to electrokinetically pump proteins through a proteolytic system. The existence of EOF in the proteolytic system packed with immobilized trypsin gel beads was proven by imaging the movement of a neutral fluorescent marker. Digestions of proteins were subsequently carried out for 12 min, and the tryptic peptides were analyzed independently using capillary electrophoresis (CE) and MALDI-TOF mass spectrometry (MS). The results from CE analysis of the tryptic peptides from the EOF-driven proteolytic system and a conventional water bath digestion were comparable. MALDI-TOF MS was used to identify the parent protein and the tryptic peptides using MS-Fit database searching. The potential utility of the EOF-driven proteolytic system was demonstrated by direct electro-elution of proteins from an acrylamide gel into the proteolytic system, with elution and tryptic digestion achieved in a single step. The EOF-driven proteolytic system, thus, provides a simple way to integrate protein digestion into an electrophoretic micro total analysis system for protein analysis and characterization.

  18. Narrowband tunable filter based on velocity-selective optical pumping in an atomic vapor.

    PubMed

    Cerè, Alessandro; Parigi, Valentina; Abad, Marta; Wolfgramm, Florian; Predojević, Ana; Mitchell, Morgan W

    2009-04-01

    We demonstrate a tunable narrowband filter based on optical-pumping-induced circular dichroism in rubidium vapor. The filter achieves a peak transmission of 14.6%, a linewidth of 80 MHz, and an out-of-band extinction of >or=35 dB. The transmission peak can be tuned within the range of the Doppler linewidth of the D1 line of atomic rubidium at 795 nm. While other atomic filters work at frequencies far from absorption, the presented technique provides light resonant with atomic media, useful for atom-photon interaction experiments. The technique could readily be extended to other alkali atoms.

  19. Helmholtz resonance in a piezoelectric-hydraulic pump-based hybrid actuator

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Woo; Wang, K. W.

    2011-01-01

    This paper demonstrates that a hydraulically acting Helmholtz resonator can exist in a piezoelectric-hydraulic pump (PHP) based hybrid actuator, which in turn affects the volumetric efficiency of the PHP. The simulation and experimental results illustrate the effect of Helmholtz resonance on the flow rate performance of the PHP. The study also shows how to shift the Helmholtz resonant frequency to a higher value through changing parameters such as the cylinder diameter and the effective bulk modulus of the working fluid, which will improve the volumetric efficiency and broaden the operating frequency range of the PHP actuator.

  20. Vane Pump Casing Machining of Dumpling Machine Based on CAD/CAM

    NASA Astrophysics Data System (ADS)

    Huang, Yusen; Li, Shilong; Li, Chengcheng; Yang, Zhen

    Automatic dumpling forming machine is also called dumpling machine, which makes dumplings through mechanical motions. This paper adopts the stuffing delivery mechanism featuring the improved and specially-designed vane pump casing, which can contribute to the formation of dumplings. Its 3D modeling in Pro/E software, machining process planning, milling path optimization, simulation based on UG and compiling post program were introduced and verified. The results indicated that adoption of CAD/CAM offers firms the potential to pursue new innovative strategies.

  1. A Fault Diagnosis Methodology for Gear Pump Based on EEMD and Bayesian Network

    PubMed Central

    Liu, Zengkai; Liu, Yonghong; Shan, Hongkai; Cai, Baoping; Huang, Qing

    2015-01-01

    This paper proposes a fault diagnosis methodology for a gear pump based on the ensemble empirical mode decomposition (EEMD) method and the Bayesian network. Essentially, the presented scheme is a multi-source information fusion based methodology. Compared with the conventional fault diagnosis with only EEMD, the proposed method is able to take advantage of all useful information besides sensor signals. The presented diagnostic Bayesian network consists of a fault layer, a fault feature layer and a multi-source information layer. Vibration signals from sensor measurement are decomposed by the EEMD method and the energy of intrinsic mode functions (IMFs) are calculated as fault features. These features are added into the fault feature layer in the Bayesian network. The other sources of useful information are added to the information layer. The generalized three-layer Bayesian network can be developed by fully incorporating faults and fault symptoms as well as other useful information such as naked eye inspection and maintenance records. Therefore, diagnostic accuracy and capacity can be improved. The proposed methodology is applied to the fault diagnosis of a gear pump and the structure and parameters of the Bayesian network is established. Compared with artificial neural network and support vector machine classification algorithms, the proposed model has the best diagnostic performance when sensor data is used only. A case study has demonstrated that some information from human observation or system repair records is very helpful to the fault diagnosis. It is effective and efficient in diagnosing faults based on uncertain, incomplete information. PMID:25938760

  2. A Fault Diagnosis Methodology for Gear Pump Based on EEMD and Bayesian Network.

    PubMed

    Liu, Zengkai; Liu, Yonghong; Shan, Hongkai; Cai, Baoping; Huang, Qing

    2015-01-01

    This paper proposes a fault diagnosis methodology for a gear pump based on the ensemble empirical mode decomposition (EEMD) method and the Bayesian network. Essentially, the presented scheme is a multi-source information fusion based methodology. Compared with the conventional fault diagnosis with only EEMD, the proposed method is able to take advantage of all useful information besides sensor signals. The presented diagnostic Bayesian network consists of a fault layer, a fault feature layer and a multi-source information layer. Vibration signals from sensor measurement are decomposed by the EEMD method and the energy of intrinsic mode functions (IMFs) are calculated as fault features. These features are added into the fault feature layer in the Bayesian network. The other sources of useful information are added to the information layer. The generalized three-layer Bayesian network can be developed by fully incorporating faults and fault symptoms as well as other useful information such as naked eye inspection and maintenance records. Therefore, diagnostic accuracy and capacity can be improved. The proposed methodology is applied to the fault diagnosis of a gear pump and the structure and parameters of the Bayesian network is established. Compared with artificial neural network and support vector machine classification algorithms, the proposed model has the best diagnostic performance when sensor data is used only. A case study has demonstrated that some information from human observation or system repair records is very helpful to the fault diagnosis. It is effective and efficient in diagnosing faults based on uncertain, incomplete information.

  3. Predicting performance of axial pump inducer of LOX booster turbo-pump of staged combustion cycle based rocket engine using CFD

    NASA Astrophysics Data System (ADS)

    Mishra, Arpit; Ghosh, Parthasarathi

    2015-12-01

    For low cost, high thrust, space missions with high specific impulse and high reliability, inert weight needs to be minimized and thereby increasing the delivered payload. Turbopump feed system for a liquid propellant rocket engine (LPRE) has the highest power to weight ratio. Turbopumps are primarily equipped with an axial flow inducer to achieve the high angular velocity and low suction pressure in combination with increased system reliability. Performance of the turbopump strongly depends on the performance of the inducer. Thus, for designing a LPRE turbopump, demands optimization of the inducer geometry based on the performance of different off-design operating regimes. In this paper, steady-state CFD analysis of the inducer of a liquid oxygen (LOX) axial pump used as a booster pump for an oxygen rich staged combustion cycle rocket engine has been presented using ANSYS® CFX. Attempts have been made to obtain the performance characteristic curves for the LOX pump inducer. The formalism has been used to predict the performance of the inducer for the throttling range varying from 80% to 113% of nominal thrust and for the different rotational velocities from 4500 to 7500 rpm. The results have been analysed to determine the region of cavitation inception for different inlet pressure.

  4. Pump for Saturated Liquids

    NASA Technical Reports Server (NTRS)

    Elliott, D. G.

    1986-01-01

    Boiling liquids pumped by device based on proven components. Expanding saturated liquid in nozzle and diverting its phases along separate paths in liquid/vapor separator raises pressure of liquid. Liquid cooled in process. Pump makes it unnecessary to pressurize cryogenic liquids in order to pump them. Problems of introducing noncondensable pressurizing gas avoided.

  5. Effects of bank storage and well pumping on base flow, Carmel River, Monterey County, California

    NASA Astrophysics Data System (ADS)

    Kondolf, G. M.; Maloney, L. M.; Williams, J. G.

    1987-06-01

    Bank storage contributions to base flow may be important on alluvial rivers with highly permeable bank materials, such as the lower Carmel River, Monterey County, California. The recharge phase of bank storage occurs during flood stage in the river when a hydraulic gradient exists from the river into the banks. In general, discharge from bank storage is most important on the recession limb of individual floods, with most stored water typically being discharged within 2-3 flood periods. As the river stage continues to fall, a hydraulic gradient from the banks to the river will be maintained and stored water will drain from the banks. On the Carmel River, the seasonal recession limb provides conditions of a gradually declining stage over several months. In 1982, a moderately wet year, bank storage contributions were detected two months after the last peak flow of the winter rainy season, during a period of critical importance to steelhead trout and probably to riparian vegetation. However, in 1983, an extremely wet year, bank storage was undetectable two months after the season's last peak flow, probably because the sustained base flow from the upper basin overwhelmed the more transient bank storage contribution. Groundwater withdrawal from the alluvial aquifer locally lowered the water table so that streamflow was influent to the banks in the reach of major pumping wells. This effect was striking in its persistence, whether the Carmel River was gaining or losing overall in its alluvial reach. Pumping rates were roughly comparable to flow losses across the well field.

  6. Hybrid distributed Raman amplification combining random fiber laser based 2nd-order and low-noise LD based 1st-order pumping.

    PubMed

    Jia, Xin-Hong; Rao, Yun-Jiang; Yuan, Cheng-Xu; Li, Jin; Yan, Xiao-Dong; Wang, Zi-Nan; Zhang, Wei-Li; Wu, Han; Zhu, Ye-Yu; Peng, Fei

    2013-10-21

    A configuration of hybrid distributed Raman amplification (H-DRA), that is formed by incorporating a random fiber laser (RFL) based 2nd-order pump and a low-noise laser-diode (LD) based 1st-order pump, is proposed in this paper. In comparison to conventional bi-directional 1st-order DRA, the effective noise figure (ENF) is found to be lower by amount of 0 to 4 dB due to the RFL-based 2nd-order pump, depending on the on-off gain, while the low-noise 1st-order Raman pump is used for compensating the worsened signal-to-noise ratio (SNR) in the vicinity towards the far end of the fiber and avoiding the potential nonlinear impact induced by excess injection of pump power and suppressing the pump-signal relative intensity noise (RIN) transfer. As a result, the gain distribution can be optimized along ultra-long fiber link, due to combination of the 2nd-order RFL and low-noise 1st-order pumping, making the transmission distance be extended significantly. We utilized such a configuration to achieve ultra-long-distance distributed sensing based on Brillouin optical time-domain analysis (BOTDA). A repeater-less sensing distance record of up to 154.4 km with 5 m spatial resolution and ~ ± 1.4 °C temperature uncertainty is successfully demonstrated.

  7. A high carrier injection terahertz quantum cascade laser based on indirectly pumped scheme

    SciTech Connect

    Razavipour, S. G. Xu, C.; Wasilewski, Z. R.; Ban, D.; Dupont, E.; Laframboise, S. R.; Chan, C. W. I.; Hu, Q.

    2014-01-27

    A Terahertz quantum cascade laser with a rather high injection coupling strength based on an indirectly pumped scheme is designed and experimentally implemented. To effectively suppress leakage current, the chosen quantum cascade module of the device is based on a five-well GaAs/Al{sub 0.25}Ga{sub 0.75}As structure. The device lases up to 151 K with a lasing frequency of 2.67 THz. This study shows that the effect of higher energy states in carrier transport and the long-range tunnel coupling between states that belong to non-neighbouring modules have to be considered in quantum design of structures with a narrow injector barrier. Moreover, the effect of interface roughness scattering between the lasing states on threshold current is crucial.

  8. Transition to an elastomeric infusion pump in home care: an evidence-based approach.

    PubMed

    Broadhurst, Daphne

    2012-01-01

    A fatal overdose of a chemotherapeutic agent delivered to a patient via an electronic infusion device served as a stark reminder of the risks that infusion therapy poses to patients and health care providers and as the impetus for a strategy to optimize safe and efficient delivery of home infusion therapy. The Academic Center for Evidence-Based Practice Star Model of Knowledge Transformation was used as the evidence-based framework for the implementation of a portable infusion pump that supports home infusion of high-risk medications, leading to increased patient and caregiver satisfaction. Evaluation of this implementation supports the use of an elastomeric infusion device for a high-risk therapy. PMID:22498484

  9. Analysis on pressure characteristics of pump turbine guide bearing rotating sump based on VOF model

    NASA Astrophysics Data System (ADS)

    Zhai, L. M.; Yao, Z.; Huang, Q. S.; Xiao, Y. X.; Wang, Z. W.

    2013-12-01

    With the technology of Computational Fluid Dynamics (CFD), this paper conducts a 3D numerical simulation for the oil and gas flow field in the Pump turbine guide bearing rotating sump. VOF model is adopted in this simulation. This study calculates distribution of the oil-air phase and characteristics of the pressure. The influence of sump rotating speed, oil level and oil viscosity on the pressure at the inlet of oil-immersion plate are discussed. The results demonstrate that the static pressure at the inlet is roughly proportional to oil level. Too low level may result in the separation between lubrication oil and supply hole on the oil-immersion plate, which then disables the oil supply. The static pressure at the inlet increases parabola as the sump rotating speed increases. To ensure the supply pressure, the unit is not suitable for long time operation under low rotating speed. The temperature-viscosity effect of the lubricant oil has little influence on the oil pressure at the supply hole. This paper provides a theoretical base for the safe design and operation of the pump turbine rotating sump, and offers the inlet boundary condition for the analysis of the oil film dynamic characteristics of the turbine guide bearing.

  10. Expression and functioning of retinal-based proton pumps in a saltern crystallizer brine.

    PubMed

    Oren, Aharon; Abu-Ghosh, Said; Argov, Tal; Kara-Ivanov, Eliahu; Shitrit, Dror; Volpert, Adi; Horwitz, Rael

    2016-01-01

    We examined the presence of bacteriorhodopsin and other retinal protein pigments in the microbial community of the saltern crystallizer ponds in Eilat, Israel, and assessed the effect of the retinal-based proton pumps on the metabolic activity. The biota of the hypersaline (~309 g salts l(-1)) brine consisted of ~2200 β-carotene-rich Dunaliella cells and ~3.5 × 10(7) prokaryotes ml(-1), most of which were flat, square or rectangular Haloquadratum-like archaea. No indications were obtained for massive presence of Salinibacter. We estimated a concentration of bacteriorhodopsin and bacteriorhodopsin-like pigments of 3.6 nmol l(-1). When illuminated, the community respiration activity of the brine samples in which oxygenic photosynthesis was inhibited by 3-(3-4-dichlorophenyl)-1,1-dimethylurea, decreased by 40-43 %. This effect was interpreted to be the result of competition between two energy yielding systems: the bacteriorhodopsin proton pump and the respiratory chain. The results presented have important implications for the interpretation of many published data on photosynthetic and respiratory activities in hypersaline environments. PMID:26507954

  11. Atomistic study of a nanometer-scale pump based on the thermal ratchet concept

    NASA Astrophysics Data System (ADS)

    Oyarzua, Elton; Walther, J. H.; Zambrano, Harvey

    2015-11-01

    In this study, a novel concept of nanoscale pump fabricated using Carbon Nanotubes (CNTs) is presented. The development of nanofluidic systems provides unprecedented possibilities for the control of biology and chemistry at the molecular level with potential applications in low energy cost devices, novel medical tools, and a new generation of sensors. CNTs offer a number of attractive features for the fabrication of fluidic nanodevices including fast flow, useful electronic and thermal properties, high mechanical strength and biocompatibility. Therefore, the transport of liquids in CNTs is now of great interest in nanofluidics. Thermophoresis is the phenomenon observed when a mixture of two or more types of motile objects experience a force induced by a thermal gradient and the different types of objects respond to it differently, inducing a motion and segregation of the objects. Using molecular dynamics simulations, we explore the possibility to design thermophoretic pumping devices fabricated of CNTs for water transport in nanoconduits. The design of the nanopumps is based on the concept of the Feynman-Smoluchowski ratchet. We aknowledge partial support from Fondecyt project 11130559 and Redoc udec.

  12. MBE growth of active regions for electrically pumped, cw-operating GaSb-based VCSELs

    NASA Astrophysics Data System (ADS)

    Kashani-Shirazi, K.; Bachmann, A.; Boehm, G.; Ziegler, S.; Amann, M.-C.

    2009-03-01

    Electrically pumped, cw-operating, single-mode GaSb-based VCSELs are attractive light sources for trace-gas sensing systems using tunable diode laser absorption spectroscopy (TDLAS) [A. Vicet, D.A. Yarekha, A. Pérona, Y. Rouillard, S. Gaillard, Spectrochimica Acta Part A 58 (2002) 2405-2412]. Only recently, the first electrically pumped (EP) devices emitting at 2.325 μm in cw-mode at room temperature have been reported [A. Bachmann, T. Lim, K. Kashani-Shirazi, O. Dier, C. Lauer, M.-C. Amann, Electronics Letters 44(3) (2008) 202-203]. The fabrication of these devices employs the molecular beam epitaxy (MBE) growth of GaSb/AlAsSb-distributed Bragg mirrors, a multi-quantum-well active region made of AlGaAsSb/InGaAsSb and an InAsSb/GaSb-buried-tunnel junction. As VCSELs are usually driven under high injection rates, an optimum electrical design of active regions is essential for high-performance devices. In this paper we present an enhanced simulation of current flow in the active region under operation conditions. The calculation includes carrier transport by drift, diffusion and tunneling. We discuss different design criteria and material compositions for active regions. Active regions with various barrier materials were incorporated into edge emitter samples to evaluate their performance. Aluminum-containing barriers show better internal efficiency compared to active regions with GaSb as the barrier material.

  13. Disulphide cross linked pullulan based cationic polymer for improved gene delivery and efflux pump inhibition.

    PubMed

    S, Priya S; R, Rekha M

    2016-10-01

    Multidrug resistance is a hurdle to successful cancer chemotherapy. Over expression of P-glycoprotein (P-gp) is a prime contributing factor for drug resistance. In this study, a disulphide cross-linked pullulan-based cationic polymer (PPSS) was synthesized to act simultaneously as gene delivery vehicle and efflux pump inhibitor. The PPSS nanoplexes were of size <200nm with the zeta potential of +15 to +20mV. The cytotoxicity studies using C6 and L929 cells showed that PPSS polymers are non-toxic even at high polymer concentrations. The PPSS/pDNA nanoplex showed superior uptake in confocal microscopy with 97% uptake by flow cytometry. The efficacy of efflux pump inhibition by the PPSS nanoplex was established by the enhanced intracellular retention of DOX. The enhanced cell death by p53/PPSS/DOX nanoplexes was attributed to the synergistic effect of P-gp inhibition and p53 transfection efficiency. Therefore, this multifunctional polymeric system may have significant promise for therapeutic application against cancer drug resistance. PMID:27459414

  14. Design and evaluation of osmotic pump-based controlled release system of Ambroxol Hydrochloride.

    PubMed

    Cheng, Xiongkai; Sun, Min; Gao, Yan; Cao, Fengliang; Zhai, Guangxi

    2011-08-01

    The purpose of the present study was to design and evaluate an osmotic pump-based drug delivery system for controlling the release of Ambroxol Hydrochloride (Amb). Citric acid, lactose and polyethylene glycol 6000 (PEG 6000) were employed as osmotic agents. Surelease EC containing polyethylene glycol 400 (PEG 400) controlling the membrane porosity was used as semi-permeable membrane. The formulation of tablet core was optimized by orthogonal design and evaluated by weighted mark method. The influences of the amount of PEG 400 and membrane thickness on Amb release were investigated. The optimal osmotic pump tablet (OPT) was evaluated in different release media and at different stirring rates. The major release power confirmed was osmotic pressure. The release of Amb from OPT was verified at a rate of approximately zero-order, and cumulative release percentage at 12?h was 92.6%. The relative bioavailability of Amb OPT in rabbits relative to the commercial sustained capsule was 109.6%. Our results showed that Amb OPT could be a practical preparation with a good prospect.

  15. Progress and challenges in electrically pumped GaN-based VCSELs

    NASA Astrophysics Data System (ADS)

    Haglund, A.; Hashemi, E.; Bengtsson, J.; Gustavsson, J.; Stattin, M.; Calciati, M.; Goano, M.

    2016-04-01

    ABSTRACT The Vertical-Cavity Surface-Emitting Laser (VCSEL) is an established optical source in short-distance optical communication links, computer mice and tailored infrared power heating systems. Its low power consumption, easy integration into two-dimensional arrays, and low-cost manufacturing also make this type of semiconductor laser suitable for application in areas such as high-resolution printing, medical applications, and general lighting. However, these applications require emission wavelengths in the blue-UV instead of the established infrared regime, which can be achieved by using GaN-based instead of GaAs-based materials. The development of GaN-based VCSELs is challenging, but during recent years several groups have managed to demonstrate electrically pumped GaN-based VCSELs with close to 1 mW of optical output power and threshold current densities between 3-16 kA/cm2. The performance is limited by challenges such as achieving high-reflectivity mirrors, vertical and lateral carrier confinement, efficient lateral current spreading, accurate cavity length control and lateral optical mode confinement. This paper summarizes different strategies to solve these issues in electrically pumped GaN-VCSELs together with state-of-the-art results. We will highlight our work on combined transverse current and optical mode confinement, where we show that many structures used for current confinement result in unintentionally optically anti-guided resonators. Such resonators can have a very high optical loss, which easily doubles the threshold gain for lasing. We will also present an alternative to the use of distributed Bragg reflectors as high-reflectivity mirrors, namely TiO2/air high contrast gratings (HCGs). Fabricated HCGs of this type show a high reflectivity (>95%) over a 25 nm wavelength span.

  16. Quantification of the secondary flow in a radial coupled centrifugal blood pump based on particle tracking velocimetry.

    PubMed

    Watanabe, Nobuo; Masuda, Takaya; Iida, Tomoya; Kataoka, Hiroyuki; Fujimoto, Tetsuo; Takatani, Setsuo

    2005-01-01

    Secondary flow in the centrifugal blood pump helps to enhance the washout effect and to minimize thrombus formation. On the other hand, it has an adverse effect on pump efficiency. Excessive secondary flow may induce hemolytic effects. Understanding the secondary flow is thus important to the design of a compact, efficient, biocompatible blood pump. This study examined the secondary flow in a radial coupled centrifugal blood pump based on a simple particle tracking velocimetry (PTV) technique. A radial magnetically coupled centrifugal blood pump has a bell-shaped narrow clearance between the impeller inner radius and the pump casing. In order to vary the flow levels through the clearance area, clearance widths of 0.25 mm and 0.50 mm and impeller washout holes with diameters of 0 mm, 2.5 mm, and 4 mm were prepared. A high-speed video camera (2000 frames per second) was used to capture the particle images from which radial flow components were derived. The flow in the space behind the impeller was assumed to be laminar and Couette type. The larger the inner clearance or diameter of washout hole, the greater was the secondary flow rate. Without washout holes, the flow behind the impeller resulted in convection. The radial flow through the washout holes of the impeller was conserved in the radial as well as in the axial direction behind the impeller. The increase in the secondary flow reduced the net pump efficiency. Simple PTV was successful in quantifying the flow in the space behind the impeller. The results verified the hypothesis that the flow behind the impeller was theoretically Couette along the circumferential direction. The convection flow observed behind the impeller agreed with the reports of other researchers. Simple PTV was effective in understanding the fluid dynamics to help improve the compact, efficient, and biocompatible centrifugal blood pump for safe clinical applications.

  17. Pump jack

    SciTech Connect

    Stanton, G. E.

    1985-02-26

    A pump jack of the type comprising a rocker arm pivotably mounted intermediate its ends on a support member, said rocker arm being divided by said pivot mounting into a sucker-rod limb and a drive limb wherein the improvement comprises a pneumatic motor pivotably attached to the drive support member and further pivotably attached to the mounting base of the pump jack to provide the power to reciprocate the pump jack. The working fluid of said pneumatic motor being natural gas which is available from the well casing of the well without any interference with the flow of the oil in the oil tube of the well thereby making use of an energy source available at any oil well without having to provide gasoline to drive a rotating type gasoline engine or electricity to drive an electric motor usually of the rotating variety. Also the stroke of a pneumatic cylinder inherently smooths out and eliminates the shock loading at the extremes of motion at the piston mounted to the sucker rods of such pump jack at the bottom of the well.

  18. Limits of Bioparticle Detection in NanoLaser Microfluidic Chips and Application to Cancer Detection in Single Cells and Mitochondria

    NASA Astrophysics Data System (ADS)

    Gourley, Paul L.; Gourley, Brett A.

    2010-03-01

    BioChips comprising light-emitting semiconductors can be configured as microfluidic laser cavities used for ultrafast analysis of bioparticles such as whole cells, organelles, virons, and macromolecules (protein,DNA,RNA). Three regimes of operation include: 1.Geometrical limit (particle radius a>>λ the laser wavelength), laser exhibits multimode spectra useful to study particle morphology, shape, and composition. 2. Mie regime (a λ) laser exhibits nano-squeezed light with single mode operation to study particle size and composition. 3.Rayleigh limit (a<<λ) laser exhibits cavity mode fluctuations to study nanoparticle mass and motion. We have recently used these biochips to study the nanolaser spectra of submicron mitochondrial bioparticles as a new probe of cancer in single cells. These high-speed, nanophotonic tools may play an important role in advancing early detection of cancer and offer improvements over conventional tumor pathology that relies on labor-intensive microscopic examination and/or older cell-staining methods that can be time-consuming and may give false readings.

  19. Continuously pumping and reactivating gas pump

    DOEpatents

    Batzer, Thomas H.; Call, Wayne R.

    1984-01-01

    Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

  20. Continuously pumping and reactivating gas pump

    DOEpatents

    Batzer, T.H.; Call, W.R.

    Apparatus for continuous pumping using cycling cryopumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels that alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independant pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

  1. Model-Following Controller Based on Neural Network for Variable Displacement Pump

    NASA Astrophysics Data System (ADS)

    Chu, Ming-Hui; Kang, Yuan; Chang, Yih-Fong; Liu, Yuan-Liang; Chang, Chuan-Wei

    The variable displacement axial piston pump (VDAPP) is inherently nonlinear, time variant and subjected to load disturbance. The controls of flow and pressure of VDAPP are achieved by changing the swashplate angle. The swashplate actuators are controlled by an electro-hydraulic proportional valve (EHPV). It is reasonable for swashplate angle of a VDAPP to employ neural network based on adaptive control. In this study, the nonlinear model of the VDAPP with a three-way electro-hydraulic proportional valve is proposed, and a neural network model-following controller is designed to control the swashplate swivel angle. The time response for the swashplate angle is analyzed by simulation and experiment, and a favorable model-following characteristic is achieved. The proposed neural controller can conduct nonlinear control in VDAPP, enhance adaptability and robustness, and improve the performance of the control system.

  2. Computational design of mixers and pumps for microfluidic systems, based on electrochemically-active conducting polymers.

    PubMed

    Kannappan, Karthik; Bogle, Gib; Travas-Sejdic, Jadranka; Williams, David E

    2011-03-28

    We present a theoretical description of the propagation of composition waves along a strip of electrochemically-active conducting polymer, upon electrochemical stimulation. We develop an efficient solution of the electro-neutral Nernst-Plank equations in 2-D for electromigration and diffusional transport in the solution based on an extension of the methods of Scharfetter and Gummel [D. L. Scharfetter and H. K. Gummel, IEEE Trans. Electron Devices, 1969, ED16, 64-77.] and of Cohen and Cooley [H. Cohen and J. W. Cooley, Biophys. J., 1965, 5, 145-162.], and demonstrate important effects of the geometry of the cell. Under some circumstances, waves reflecting back from the end of the strip are predicted. We then demonstrate theoretically how such waves, associated as they are with expansion of the polymer, could be employed to enhance mixing or induce pumping in microfluidic systems.

  3. Characterization of a ferrofluid-based thermomagnetic pump for microfluidic applications

    NASA Astrophysics Data System (ADS)

    Pal, Souvik; Datta, Amitava; Sen, Swarnendu; Mukhopdhyay, Achintya; Bandopadhyay, Kallol; Ganguly, Ranjan

    2011-11-01

    We experimentally characterize the performance of a miniature thermomagnetic pump, where suitably imposed temperature and magnetic field gradients are used to drive ferrofluid in a 2 mm diameter glass capillary tube, without application of any external pressure gradient. Such a pump can operate in a hermetically sealed micro electromechanical system configuration without any moving part, and is thus capable of handling microfluidic samples with little risk of contamination. In the experiment, the ferrofluid in the capillary is exposed to a magnetic field using a solenoid; a small resistive heater wrapped on the tube wall is used to create temperature gradient in such a way that the Kelvin body force in the medium produces a net unbalanced axial component. This causes a thermomagnetic pumping action, transporting the ferrofluid in the capillary tube from the colder end to the warmer end. Performance of the thermomagnetic pump is investigated experimentally to characterize the pump pressure head and discharge under different working conditions, namely, the magnetic field strength, heating power, and ferrofluid properties. A comparison with two other field actuation pumps at comparable length scales is also presented. The pump produces higher output at lower power supplies and magnetic field compared to the other two pumps.

  4. The pipeline oil pumping engineering based on the Plant Wide Control technology

    NASA Astrophysics Data System (ADS)

    Starikov, D. P.; Rybakov, E. A.; Gromakov, E. I.

    2015-04-01

    This article provides recommendations for the use technology Plant Wide Control to control the pumping of oil through the pipeline. The proposed engineering using pipeline management in general (Pipe Wide Control) will reduce the loss of electric power at the expense of the balance of pumping stations located along the pipeline route.

  5. A biomolecular detection method based on charge pumping in a nanogap embedded field-effect-transistor biosensor

    NASA Astrophysics Data System (ADS)

    Kim, Sungho; Ahn, Jae-Hyuk; Park, Tae Jung; Lee, Sang Yup; Choi, Yang-Kyu

    2009-06-01

    A unique direct electrical detection method of biomolecules, charge pumping, was demonstrated using a nanogap embedded field-effect-transistor (FET). With aid of a charge pumping method, sensitivity can fall below the 1 ng/ml concentration regime in antigen-antibody binding of an avian influenza case. Biomolecules immobilized in the nanogap are mainly responsible for the acute changes of the interface trap density due to modulation of the energy level of the trap. This finding is supported by a numerical simulation. The proposed detection method for biomolecules using a nanogap embedded FET represents a foundation for a chip-based biosensor capable of high sensitivity.

  6. [Initial research of one-beam pumping up-conversion 3D volumetric display based on Er:ZBLAN glass].

    PubMed

    Chen, Xiao-bo; Li, Mei-xian; Wen, Ou; Zhang, Fu-chu; Song, Zeng-fu

    2003-06-01

    This paper investigates one-beam pumping up-conversion three-dimensional volumetric display, which is based on a Er:ZBLAN fluoride glass. The light-length of the facula of one-beam up-conversion luminescence was studied by a 966 nm semiconductor laser. The up-conversion luminescence spectrum was also obtained. It was found that the property of one-beam pumping three-dimensional volumetric display can be improved significantly by 1.52 microns LD laser multi-photon up-conversion, this finding has not been reported.

  7. [Research on flow characteristics in a non-blade centrifugal blood pump based on CFD technology].

    PubMed

    Cheng, Yunzhang; Luo, Binhai; Wu, Wenquan; Jiang, Lei

    2010-10-01

    The problem of thrombus and hemolysis in blood pump has always been an important topic to study in the development of the blood pump. Numbers of research results show that it is the complicated flow and the high shear stress of the mechanical movement that result in the thrombus and hemolysis. In this study, with the cooperation of Shanghai Children's Medical Center, we have used computational fluid dynamics (CFD) commercial software FLUENT to compute and analyze the flow characteristics in a non-blade centrifugal blood pump. The results figure out that this pump has a reasonable flow distribution and the shear stress distribution is under the critical broken state of red blood cell; meanwhile, there is less thrombus and hemolysis in this pump. So it is in the foreground for clinical use.

  8. Municipal water-based heat pump heating and/or cooling systems: Findings and recommendations. Final report

    SciTech Connect

    Bloomquist, R.G.; Wegman, S.

    1998-04-01

    The purpose of the present work was to determine if existing heat pump systems based on municipal water systems meet existing water quality standards, to analyze water that has passed through a heat pump or heat exchanger to determine if corrosion products can be detected, to determine residual chlorine levels in municipal waters on the inlet as well as the outlet side of such installations, to analyses for bacterial contaminants and/or regrowth due to the presence of a heat pump or heat exchanger, to develop and suggest criteria for system design and construction, to provide recommendations and specifications for material and fluid selection, and to develop model rules and regulations for the installation, operation, and monitoring of new and existing systems. In addition, the Washington State University (WSU) has evaluated availability of computer models that would allow for water system mapping, water quality modeling and system operation.

  9. GAS-PHASE AND PARTICULATE EMISSIONS DURING APPLICATION OF A WATER-BASED CLEANER WITH A HAND-PUMP SPRAYER

    EPA Science Inventory

    The paper gives results of tests in a controlled environment test room to measure concentrations of 2-butoxyethanol and particles during application of a cleaner to realistic surfaces (counter tops, glass, walls). (NOTE: Users of water-based cleaners applied with hand-pump spray...

  10. PUMP CONSTRUCTION

    DOEpatents

    Strickland, G.; Horn, F.L.; White, H.T.

    1960-09-27

    A pump which utilizes the fluid being pumped through it as its lubricating fluid is described. This is achieved by means of an improved bearing construction in a pump of the enclosed or canned rotor type. At the outlet end of the pump, adjacent to an impeller mechanism, there is a bypass which conveys some of the pumped fluid to a chamber at the inlet end of the pump. After this chamber becomes full, the pumped fluid passes through fixed orifices in the top of the chamber and exerts a thrust on the inlet end of the pump rotor. Lubrication of the rotor shaft is accomplished by passing the pumped fluid through a bypass at the outlet end of the rotor shaft. This bypass conveys Pumped fluid to a cooling means and then to grooves on the surface of the rotor shait, thus lubricating the shaft.

  11. Particle size distribution of aerosols sprayed from household hand-pump sprays containing fluorine-based and silicone-based compounds.

    PubMed

    Kawakami, Tsuyoshi; Isama, Kazuo; Ikarashi, Yoshiaki

    2015-01-01

    Japan has published safety guideline on waterproof aerosol sprays. Furthermore, the Aerosol Industry Association of Japan has adopted voluntary regulations on waterproof aerosol sprays. Aerosol particles of diameter less than 10 µm are considered as "fine particles". In order to avoid acute lung injury, this size fraction should account for less than 0.6% of the sprayed aerosol particles. In contrast, the particle size distribution of aerosols released by hand-pump sprays containing fluorine-based or silicone-based compounds have not been investigated in Japan. Thus, the present study investigated the aerosol particle size distribution of 16 household hand-pump sprays. In 4 samples, the ratio of fine particles in aerosols exceeded 0.6%. This study confirmed that several hand-pump sprays available in the Japanese market can spray fine particles. Since the hand-pump sprays use water as a solvent and their ingredients may be more hydrophilic than those of aerosol sprays, the concepts related to the safety of aerosol-sprays do not apply to the hand pump sprays. Therefore, it may be required for the hand-pump spray to develop a suitable method for evaluating the toxicity and to establish the safety guideline. PMID:26821469

  12. Silicon-Based Chemical Motors: An Efficient Pump for Triggering and Guiding Fluid Motion Using Visible Light

    PubMed Central

    2015-01-01

    We report a simple yet highly efficient chemical motor that can be controlled with visible light. The motor made from a noble metal and doped silicon acts as a pump, which is driven through a light-activated catalytic reaction process. We show that the actuation is based on electro-osmosis with the electric field generated by chemical reactions at the metal and silicon surfaces, whereas the contribution of diffusio-osmosis to the actuation is negligible. Surprisingly, the pump can be operated using water as fuel. This is possible because of the large ζ-potential of silicon, which makes the electro-osmotic fluid motion sizable even though the electric field generated by the reaction is weak. The electro-hydrodynamic process is greatly amplified with the addition of reactive species, such as hydrogen peroxide, which generates higher electric fields. Another remarkable finding is the tunability of silicon-based pumps. That is, it is possible to control the speed of the fluid with light. We take advantage of this property to manipulate the spatial distribution of colloidal microparticles in the liquid and to pattern colloidal microparticle structures at specific locations on a wafer surface. Silicon-based pumps hold great promise for controlled mass transport in fluids. PMID:26349036

  13. Analysis of the performances of an axial flow tandem pump based on CFD computations

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Bai, Z. Y.; Zhang, M. D.; Wang, G. Y.

    2012-11-01

    Tandem pump, compared with multistage pump, goes without guide vanes between impellers. Significant reduction of the axial geometry scale, resulting from lack of guide vanes, makes great sense to high-speed propulsion. Direct interactions between front and rear impellers may lead to special flows, which are different from those in a multistage pump. There are few studies of these differences. In this article, CFD computations of flows in an axial flow tandem pump are conducted to predict the performances. FBM turbulence model, which is introduced to commercial software, is used for the simulations. Circulation coefficient is defined to help analyze energy characteristics. The results demonstrate that power of the tandem pump increases slowly as discharge is getting larger. The tandem pump has better adaptability under large discharge conditions. The head of the rear impeller is not sensitive to discharge's change, which results from that the front impeller weakens the influence of discharge's change on the rear impeller, so pump's energy characteristics may be improved.

  14. Development of a pump-turbine runner based on multiobjective optimization

    NASA Astrophysics Data System (ADS)

    Xuhe, W.; Baoshan, Z.; Lei, T.; Jie, Z.; Shuliang, C.

    2014-03-01

    As a key component of reversible pump-turbine unit, pump-turbine runner rotates at pump or turbine direction according to the demand of power grid, so higher efficiencies under both operating modes have great importance for energy saving. In the present paper, a multiobjective optimization design strategy, which includes 3D inverse design method, CFD calculations, response surface method (RSM) and multiobjective genetic algorithm (MOGA), is introduced to develop a model pump-turbine runner for middle-high head pumped storage plant. Parameters that controlling blade shape, such as blade loading and blade lean angle at high pressure side are chosen as input parameters, while runner efficiencies under both pump and turbine modes are selected as objective functions. In order to validate the availability of the optimization design system, one runner configuration from Pareto front is manufactured for experimental research. Test results show that the highest unit efficiency is 91.0% under turbine mode and 90.8% under pump mode for the designed runner, of which prototype efficiencies are 93.88% and 93.27% respectively. Viscous CFD calculations for full passage model are also conducted, which aim at finding out the hydraulic improvement from internal flow analyses.

  15. [Numerical assessment of impeller features of centrifugal blood pump based on fast hemolysis approximation model].

    PubMed

    Shou, Chen; Guo, Yongjun; Su, Lei; Li, Yongqian

    2014-12-01

    The impeller profile, which is one of the most important factors, determines the creation of shear stress which leads to blood hemolysis in the internal flow of centrifugal blood pump. The investigation of the internal flow field in centrifugal blood pump and the estimation of the hemolysis within different impeller profiles will provide information to improve the performance of centrifugal blood pump. The SST kappa-omega with low Reynolds correction was used in our laboratory to study the internal flow fields for four kinds of impellers of centrifugal blood pump. The flow fields included distributions of pressure field, velocity field and shear stress field. In addition, a fast numerical hemolysis approximation was adopted to calculate the normalized index of hemolysis (NIH). The results indicated that the pressure field distribution in all kinds of blood pump were reasonable, but for the log spiral impeller pump, the vortex and backflow were much lower than those of the other pumps, and the high shear stress zone was just about 0.004%, and the NIH was 0.0089.

  16. PV Array Driven Adjustable Speed Drive for a Lunar Base Heat Pump

    NASA Technical Reports Server (NTRS)

    Domijan, Alexander, Jr.; Buchh, Tariq Aslam

    1995-01-01

    A study of various aspects of Adjustable Speed Drives (ASD) is presented. A summary of the relative merits of different ASD systems presently in vogue is discussed. The advantages of using microcomputer based ASDs is now widely understood and accepted. Of the three most popular drive systems, namely the Induction Motor Drive, Switched Reluctance Motor Drive and Brushless DC Motor Drive, any one may be chosen. The choice would depend on the nature of the application and its requirements. The suitability of the above mentioned drive systems for a photovoltaic array driven ASD for an aerospace application are discussed. The discussion is based on the experience of the authors, various researchers and industry. In chapter 2 a PV array power supply scheme has been proposed, this scheme will have an enhanced reliability in addition to the other known advantages of the case where a stand alone PV array is feeding the heat pump. In chapter 3 the results of computer simulation of PV array driven induction motor drive system have been included. A discussion on these preliminary simulation results have also been included in this chapter. Chapter 4 includes a brief discussion on various control techniques for three phase induction motors. A discussion on different power devices and their various performance characteristics is given in Chapter 5.

  17. Cyanobacterial Light-Driven Proton Pump, Gloeobacter Rhodopsin: Complementarity between Rhodopsin-Based Energy Production and Photosynthesis

    PubMed Central

    Choi, Ah Reum; Shi, Lichi; Brown, Leonid S.; Jung, Kwang-Hwan

    2014-01-01

    A homologue of type I rhodopsin was found in the unicellular Gloeobacter violaceus PCC7421, which is believed to be primitive because of the lack of thylakoids and peculiar morphology of phycobilisomes. The Gloeobacter rhodopsin (GR) gene encodes a polypeptide of 298 amino acids. This gene is localized alone in the genome unlike cyanobacterium Anabaena opsin, which is clustered together with 14 kDa transducer gene. Amino acid sequence comparison of GR with other type I rhodopsin shows several conserved residues important for retinal binding and H+ pumping. In this study, the gene was expressed in Escherichia coli and bound all-trans retinal to form a pigment (λmax  = 544 nm at pH 7). The pKa of proton acceptor (Asp121) for the Schiff base, is approximately 5.9, so GR can translocate H+ under physiological conditions (pH 7.4). In order to prove the functional activity in the cell, pumping activity was measured in the sphaeroplast membranes of E. coli and one of Gloeobacter whole cell. The efficient proton pumping and rapid photocycle of GR strongly suggests that Gloeobacter rhodopsin functions as a proton pumping in its natural environment, probably compensating the shortage of energy generated by chlorophyll-based photosynthesis without thylakoids. PMID:25347537

  18. Hydrogen-bonding interaction of the protonated schiff base with halides in a chloride-pumping bacteriorhodopsin mutant.

    PubMed

    Shibata, Mikihiro; Ihara, Kunio; Kandori, Hideki

    2006-09-01

    Bacteriorhodopsin (BR) and halorhodopsin (HR) are light-driven proton and chloride ion pumps, respectively, in Halobacterium salinarum. The amino acid identity of these proteins is about 25%, suggesting that each has been optimized for their own functions during evolution. However, it is known that the BR mutants, D85T and D85S, can pump chloride ions. This fact implies that the Schiff base region is important in determining ionic selectivity. The X-ray crystallographic structure of D85S(Br(-)) showed the presence of a bromide ion in the Schiff base region (Facciotti, M. T., Cheung, V. S., Nguyen, D., Rouhani, S., and Glaeser, R. M. (2003) Biophys. J. 85, 451-458). In this article, we report on the study of hydrogen bonds of the Schiff base and water molecules in D85S in the absence and presence of various halides, assigning their N-D and O-D stretching vibrations in D(2)O, respectively, in low-temperature Fourier-transform infrared (FTIR) spectroscopy. We found that the hydrogen bond of the Schiff base in D85S(Cl(-)) is much stronger than that in HR, being as strong as that in wild-type BR. Similar halide dependence in D85S and in solution implies that the Schiff base forms a direct hydrogen bond with a halide, consistent with the X-ray structure. Photoisomerization causes a weakened hydrogen bond of the Schiff base, and halide dependence on the stretching frequency is lost. These spectral features are similar to those in the photocycle of proton-pumping BR, though the weakened hydrogen bond is more significant for BR. However, the spectral features of water bands in D85S are closer to chloride-pumping HR because O-D stretching vibrations of water are observed only at >2500 cm(-)(1). Unlike in BR, we did not observe strongly hydrogen-bonded water molecules for halide-pumping D85S mutants. This observation agrees with our recent hypothesis that strongly hydrogen-bonded water molecules are required for the proton-pumping activity of archaeal rhodopsins. Hydrogen

  19. Numerical analysis of the internal flow field in screw centrifugal blood pump based on CFD

    NASA Astrophysics Data System (ADS)

    Han, W.; Han, B. X.; Y Wang, H.; Shen, Z. J.

    2013-12-01

    As to the impeller blood pump, the high speed of the impeller, the local high shear force of the flow field and the flow dead region are the main reasons for blood damage. The screw centrifugal pump can effectively alleviate the problems of the high speed and the high shear stress for the impeller. The softness and non-destructiveness during the transfer process can effectively reduce the extent of the damage. By using CFD software, the characteristics of internal flow are analyzed in the screw centrifugal pump by exploring the distribution rules of the velocity, pressure and shear deformation rate of the blood when it flows through the impeller and the destructive effects of spiral blades on blood. The results show that: the design of magnetic levitation solves the sealing problems; the design of regurgitation holes solves the problem of the flow dead zone; the magnetic levitated microcirculation screw centrifugal pump can effectively avoid the vortex, turbulence and high shear forces generated while the blood is flowing through the pump. Since the distribution rules in the velocity field, pressure field and shear deformation rate of the blood in the blood pump are comparatively uniform and the gradient change is comparatively small, the blood damage is effectively reduced.

  20. Electrically pumped near-ultraviolet lasing from ZnO Nanowire Based Heterojunctions

    NASA Astrophysics Data System (ADS)

    Mu, Richard; Xu, Haiyang; Liu, Yichun

    2014-03-01

    ZnO with a band gap (3.37 eV) and an exciton binding energy (60 meV) is a promising material for ultraviolet (UV) light-emitting diodes (LEDs) and low-threshold lasing diodes. Much progress has been made recently to enhance band edge emission of ZnO nanowire (NW) structure through surface passivation and local surface plasmon enahncement with metal nanparticles. Efforts have been made to fabricate electrically pumped near-ultraviolet lasing devices with metal/insulator/semiconductor laser diode based on ZnO/MgO core/shell nanowires with and without metal nanoparticle presences. The nanowire diode shows higher emission intensity at relatively low operating current density compared with the planar device. The improved efficiency is attributed to enhanced exciton oscillator strength and superior carrier transport properties of single-crystalline ZnO nanowires, and effective surface passivation by MgO coating. Random laser action was confirmed by the calculation of quality factor and the real-time changes of lasing spectra. The results reveal that the MgO coating serves as electron blocking, hole supplying and surface passivation layer for the nanowire heterostructure. Other approaches will also be presented and discussed in the presentation. DMR-0423914, NSF-CREST HRD-0420516, and DOD W911NF-11-1-0156 and -13-1-0153.

  1. Energy-efficient miniature-scale heat pumping based on shape memory alloys

    NASA Astrophysics Data System (ADS)

    Ossmer, Hinnerk; Wendler, Frank; Gueltig, Marcel; Lambrecht, Franziska; Miyazaki, Shuichi; Kohl, Manfred

    2016-08-01

    Cooling and thermal management comprise a major part of global energy consumption. The by far most widespread cooling technology today is vapor compression, reaching rather high efficiencies, but promoting global warming due to the use of environmentally harmful refrigerants. For widespread emerging applications using microelectronics and micro-electro-mechanical systems, thermoelectrics is the most advanced technology, which however hardly reaches coefficients of performance (COP) above 2.0. Here, we introduce a new approach for energy-efficient heat pumping using the elastocaloric effect in shape memory alloys. This development is mainly targeted at applications on miniature scales, while larger scales are envisioned by massive parallelization. Base materials are cold-rolled textured Ti49.1Ni50.5Fe0.4 foils of 30 μm thickness showing an adiabatic temperature change of +20/-16 K upon superelastic loading/unloading. Different demonstrator layouts consisting of mechanically coupled bridge structures with large surface-to-volume ratios are developed allowing for control by a single actuator as well as work recovery. Heat transfer times are in the order of 1 s, being orders of magnitude faster than for bulk geometries. Thus, first demonstrators achieve values of specific heating and cooling power of 4.5 and 2.9 W g-1, respectively. A maximum temperature difference of 9.4 K between heat source and sink is reached within 2 min. Corresponding COP on the device level are 4.9 (heating) and 3.1 (cooling).

  2. Evidence-based support for the use of proton pump inhibitors in cancer therapy.

    PubMed

    Fais, Stefano

    2015-01-01

    'We can only cure what we can understand first', said Otto H. Warburg, the 1931 Nobel laureate for his discovery on tumor metabolism. Unfortunately, we still don't know too much the mechanisms underlying of cancer development and progression. One of the unsolved mystery includes the strategies that cancer cells adopt to cope with an adverse microenvironment. However, we knew, from the Warburg's discovery, that through their metabolism based on sugar fermentation, cancer cells acidify their microenvironment and this progressive acidification induces a selective pressure, leading to development of very malignant cells entirely armed to survive in the hostile microenvironment generated by their own metabolism. One of the most mechanism to survive to the acidic tumor microenvironment are proton exchangers not allowing intracellular acidification through a continuous elimination of H(+) either outside the cells or within the internal vacuoles. This article wants to comment a translational process through which from the preclinical demonstration that a class of proton pump inhibitors (PPI) exploited worldwide for peptic ulcer treatment and gastroprotection are indeed chemosensitizers as well, we have got to the clinical proof of concept that PPI may well be included in new anti-cancer strategies, and with a solid background and rationale. PMID:26597250

  3. Study on water lubricated bearings of high speed pump based on numerical simulation

    NASA Astrophysics Data System (ADS)

    Bai, Y. X.; Kong, F. Y.; Sun, J. R.; Yuan, X.

    2016-05-01

    A method is presented for calculating and analyzing the performance of water lubricated bearing of high speed pump under different structure. In present work, six kinds of bearings in different radial clearance(C), which are 0.02, 0.04, 0.06, 0.08, 0.10and0.12 respectively, under the same minimum water film thickness, have been designed. The models are built by CREO and numerical simulated by ansys. The main content of the present work is to analyze the relationship between the pressure and the load carrying capacity with different radial clearance(C) by ansys workbench based on Fluid-Solid coupling through ansys workbench.The stress deformations of bearings are also acquired through thermal-structure coupling. From the comparing result among the numerical analysis under the six different model of water lubricated bearing, the relationship between radial clearance(C) and load carrying capacity, as well as the deformation of bearing under different radial clearance(C), are obtained. Further, results indicates that, a proper selection of radial clearance(C) is essential to enhance the bearing performance.

  4. Energy-efficient miniature-scale heat pumping based on shape memory alloys

    NASA Astrophysics Data System (ADS)

    Ossmer, Hinnerk; Wendler, Frank; Gueltig, Marcel; Lambrecht, Franziska; Miyazaki, Shuichi; Kohl, Manfred

    2016-08-01

    Cooling and thermal management comprise a major part of global energy consumption. The by far most widespread cooling technology today is vapor compression, reaching rather high efficiencies, but promoting global warming due to the use of environmentally harmful refrigerants. For widespread emerging applications using microelectronics and micro-electro-mechanical systems, thermoelectrics is the most advanced technology, which however hardly reaches coefficients of performance (COP) above 2.0. Here, we introduce a new approach for energy-efficient heat pumping using the elastocaloric effect in shape memory alloys. This development is mainly targeted at applications on miniature scales, while larger scales are envisioned by massive parallelization. Base materials are cold-rolled textured Ti49.1Ni50.5Fe0.4 foils of 30 μm thickness showing an adiabatic temperature change of +20/‑16 K upon superelastic loading/unloading. Different demonstrator layouts consisting of mechanically coupled bridge structures with large surface-to-volume ratios are developed allowing for control by a single actuator as well as work recovery. Heat transfer times are in the order of 1 s, being orders of magnitude faster than for bulk geometries. Thus, first demonstrators achieve values of specific heating and cooling power of 4.5 and 2.9 W g‑1, respectively. A maximum temperature difference of 9.4 K between heat source and sink is reached within 2 min. Corresponding COP on the device level are 4.9 (heating) and 3.1 (cooling).

  5. Robust monolithic silica-based on-chip electro-osmotic micro-pump.

    PubMed

    Nie, Fu-Qiang; Macka, Mirek; Barron, Leon; Connolly, Damian; Kent, Nigel; Paull, Brett

    2007-05-01

    A robust, compact, on-chip, electro-osmotic micro-pump (EOP) for micro-flow analysis, based on parallel, encased, 10 x 0.1 mm I.D. monolithic silica capillary columns has been developed. A 15 x 40 x 2 mm poly(methyl methacrylate) (PMMA) chip, containing a total of nine parallel EOP systems was fabricated, allowing the use of single, double or triple monolithic columns to produce increased flow as required. The monolithic silica was compatible with both aqueous and organic solvents without swelling or shrinking problems, with the triple column EOP capable of generating flow of up to 0.6 microL min(-1) under zero pressure load and over 0.1 microL min(-1) with an applied pressure of ca. 2.4 bar using an applied voltage of just 2 kV. Current generated at the 2 kV applied voltage for a 2 mM acetate buffer solution (pH 4.5) was under 4 microA, allowing stable, bubble-free flow. The developed triple column EOP was incorporated within a micro-fluidic chip (5.0 x 2.0 x 0.4 cm) integrated with a second single 10 x 0.1 mm column EOP, for combined sample injection and simple on-chip micro-flow analysis.

  6. Pumping of helium and hydrogen by sputter-ion pumps. II. Hydrogen pumping

    SciTech Connect

    Welch, K.M.; Pate, D.J.; Todd, R.J. )

    1994-05-01

    The pumping of helium by various forms of sputter-ion pumps (i.e., SIPs) is given in part I [K. M. Welch, D. J. Pate, and R. J. Todd, J. Vac. Sci. Technol. A [bold 11], 1607 (1993)]. The pumping of hydrogen in diode and triode SIPs is herein discussed. The type of cathode material used in these pumps is shown to have a significant impact on the effectiveness with which hydrogen is pumped. Examples of this include data for pumps with aluminum, titanium, and titanium-alloy cathodes. Diode pumps with aluminum cathodes are shown to be no more effective in the pumping of hydrogen than in the pumping of helium. The use of titanium anodes and titanium [ital shielding] of a pump body is also shown to impact measurably the speed of a pump at very low pressures. This stems from the fact that hydrogen is [times]10[sup 6] more soluble in titanium than in stainless steel. Hydrogen becomes resident in the anodes because of fast neutral burial. Ions and fast neutrals of hydrogen are also buried in the walls of pump bodies. Outgassing of this hydrogen from the anodes and pump bodies results in a gradual increase in pump base pressure and consequential decrease in hydrogen pump speed at very low base pressures.

  7. Ferromagnetic Resonance Spin Pumping and Electrical Spin Injection in Silicon-Based Metal-Oxide-Semiconductor Heterostructures

    NASA Astrophysics Data System (ADS)

    Pu, Y.; Odenthal, P. M.; Adur, R.; Beardsley, J.; Swartz, A. G.; Pelekhov, D. V.; Flatté, M. E.; Kawakami, R. K.; Pelz, J.; Hammel, P. C.; Johnston-Halperin, E.

    2015-12-01

    We present the measurement of ferromagnetic resonance (FMR-)driven spin pumping and three-terminal electrical spin injection within the same silicon-based device. Both effects manifest in a dc spin accumulation voltage Vs that is suppressed as an applied field is rotated to the out-of-plane direction, i.e., the oblique Hanle geometry. Comparison of Vs between these two spin injection mechanisms reveals an anomalously strong suppression of FMR-driven spin pumping with increasing out-of-plane field Happz . We propose that the presence of the large ac component to the spin current generated by the spin pumping approach, expected to exceed the dc value by 2 orders of magnitude, is the origin of this discrepancy through its influence on the spin dynamics at the oxide-silicon interface. This convolution, wherein the dynamics of both the injector and the interface play a significant role in the spin accumulation, represents a new regime for spin injection that is not well described by existing models of either FMR-driven spin pumping or electrical spin injection.

  8. Magnetocaloric pump

    NASA Technical Reports Server (NTRS)

    Brown, G. V.

    1973-01-01

    Very cold liquids and gases such as helium, neon, and nitrogen can be pumped by using magnetocaloric effect. Adiabatic magnetization and demagnetization are used to alternately heat and cool slug of pumped fluid contained in closed chamber.

  9. Casing pump

    SciTech Connect

    Bass, H.E.; Bass, R.E.

    1987-09-29

    A natural gas operated pump is described for use in the casing of an oil well, comprising: a tubular pump body having an open lower end for admitting well fluids to the interior of the pump body and an open upper end, wherein a downwardly facing seating surface is formed on the inner periphery of the pump body adjacent the upper end thereof; means for forming a seal between the pump body and the casing of the well; a rod extending longitudinally through the seating surface formed in the pump body and protruding from the upper end of the pump body; a valve member mounted on the rod below the seating surface and shaped to mate with the seating surface; and means for vertically positioning the rod in proportion to fluid pressure within the pump body.

  10. ELECTROMAGNETIC PUMP

    DOEpatents

    Pulley, O.O.

    1954-08-17

    This patent reiates to electromagnetic pumps for electricity-conducting fluids and, in particular, describes several modifications for a linear conduction type electromagnetic interaction pump. The invention resides in passing the return conductor for the current traversing the fiuid in the duct back through the gap in the iron circuit of the pump. Both the maximum allowable pressure and the efficiency of a linear conduction electromagnetic pump are increased by incorporation of the present invention.

  11. Accuracy of a new patch pump based on a microelectromechanical system (MEMS) compared to other commercially available insulin pumps: results of the first in vitro and in vivo studies.

    PubMed

    Borot, Sophie; Franc, Sylvia; Cristante, Justine; Penfornis, Alfred; Benhamou, Pierre-Yves; Guerci, Bruno; Hanaire, Hélène; Renard, Eric; Reznik, Yves; Simon, Chantal; Charpentier, Guillaume

    2014-11-01

    The JewelPUMP™ (JP) is a new patch pump based on a microelectromechanical system that operates without any plunger. The study aimed to evaluate the infusion accuracy of the JP in vitro and in vivo. For the in vitro studies, commercially available pumps meeting the ISO standard were compared to the JP: the MiniMed® Paradigm® 712 (MP), Accu-Chek® Combo (AC), OmniPod® (OP), Animas® Vibe™ (AN). Pump accuracy was measured over 24 hours using a continuous microweighing method, at 0.1 and 1 IU/h basal rates. The occlusion alarm threshold was measured after a catheter occlusion. The JP, filled with physiological serum, was then tested in 13 patients with type 1 diabetes simultaneously with their own pump for 2 days. The weight difference was used to calculate the infused insulin volume. The JP showed reduced absolute median error rate in vitro over a 15-minute observation window compared to other pumps (1 IU/h): ±1.02% (JP) vs ±1.60% (AN), ±1.66% (AC), ±2.22% (MP), and ±4.63% (OP), P < .0001. But there was no difference over 24 hours. At 0.5 IU/h, the JP was able to detect an occlusion earlier than other pumps: 21 (19; 25) minutes vs 90 (85; 95), 58 (42; 74), and 143 (132; 218) minutes (AN, AC, MP), P < .05 vs AN and MP. In patients, the 24-hour flow error was not significantly different between the JP and usual pumps (-2.2 ± 5.6% vs -0.37 ± 4.0%, P = .25). The JP was found to be easier to wear than conventional pumps. The JP is more precise over a short time period, more sensitive to catheter occlusion, well accepted by patients, and consequently, of potential interest for a closed-loop insulin delivery system.

  12. Accuracy of a new patch pump based on a microelectromechanical system (MEMS) compared to other commercially available insulin pumps: results of the first in vitro and in vivo studies.

    PubMed

    Borot, Sophie; Franc, Sylvia; Cristante, Justine; Penfornis, Alfred; Benhamou, Pierre-Yves; Guerci, Bruno; Hanaire, Hélène; Renard, Eric; Reznik, Yves; Simon, Chantal; Charpentier, Guillaume

    2014-11-01

    The JewelPUMP™ (JP) is a new patch pump based on a microelectromechanical system that operates without any plunger. The study aimed to evaluate the infusion accuracy of the JP in vitro and in vivo. For the in vitro studies, commercially available pumps meeting the ISO standard were compared to the JP: the MiniMed® Paradigm® 712 (MP), Accu-Chek® Combo (AC), OmniPod® (OP), Animas® Vibe™ (AN). Pump accuracy was measured over 24 hours using a continuous microweighing method, at 0.1 and 1 IU/h basal rates. The occlusion alarm threshold was measured after a catheter occlusion. The JP, filled with physiological serum, was then tested in 13 patients with type 1 diabetes simultaneously with their own pump for 2 days. The weight difference was used to calculate the infused insulin volume. The JP showed reduced absolute median error rate in vitro over a 15-minute observation window compared to other pumps (1 IU/h): ±1.02% (JP) vs ±1.60% (AN), ±1.66% (AC), ±2.22% (MP), and ±4.63% (OP), P < .0001. But there was no difference over 24 hours. At 0.5 IU/h, the JP was able to detect an occlusion earlier than other pumps: 21 (19; 25) minutes vs 90 (85; 95), 58 (42; 74), and 143 (132; 218) minutes (AN, AC, MP), P < .05 vs AN and MP. In patients, the 24-hour flow error was not significantly different between the JP and usual pumps (-2.2 ± 5.6% vs -0.37 ± 4.0%, P = .25). The JP was found to be easier to wear than conventional pumps. The JP is more precise over a short time period, more sensitive to catheter occlusion, well accepted by patients, and consequently, of potential interest for a closed-loop insulin delivery system. PMID:25079676

  13. Piezoelectric-hydraulic pump based band brake actuation system for automotive transmission control

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Woo; Wang, K. W.

    2007-04-01

    The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic pump to the input of the band brake. Compared with the current systems, this new actuator features much simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated using experimental data. Performance tests on the hardware and system simulations utilizing the validated model are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for AT shift control.

  14. High repetition rate collisional soft x-ray lasers based on grazing incidence pumping

    SciTech Connect

    Luther, B M; Wang, Y; Larotonda, M A; Alessi, D; Berrill, M; Rocca, J J; Dunn, J; Keenan, R; Shlyaptsev, V N

    2005-11-18

    We discuss the demonstration of gain-saturated high repetition rate table-top soft x-ray lasers producing microwatt average powers at wavelengths ranging from 13.9 to 33 nm. The results were obtained heating a pre-created plasma with a picosecond optical laser pulse impinging at grazing incidence onto a pre-created plasma. This pumping geometry increases the energy deposition efficiency of the pump beam into the gain region, making it possible to saturate soft x-ray lasers in this wavelength range with a short pulse pump energy of only 1 J at 800 nm wavelength. Results corresponding to 5 Hz repetition rate operation of gain-saturated 14.7 nm Ni-like Pd and 32.6 nm line Ne-like Ti lasers pumped by a table-top Ti:sapphire laser are reported. We also discuss results obtained using a 1 {omega} 1054 nm pre-pulse and 2{omega} 527 nm short pulse from a Nd:glass pump laser. This work demonstrates the feasibility of producing compact high average power soft x-ray lasers for applications.

  15. Numerical prediction of pressure fluctuations in a prototype pump turbine base on PANS methods

    NASA Astrophysics Data System (ADS)

    Liu, J. T.; Li, Y.; Gao, Y.; Hu, Q.; Wu, Y. L.

    2016-05-01

    Unsteady flow and pressure fluctuations within a prototypel pump turbine are numerically studied using a nonlinear Partial Averaged Navier Stokes (PANS) model. Pump turbine operating at different conditions with guide vanes opening angle 6° is simulated. Results revealed that the predictions of performance and relative peak-to-peak amplitude by PANS approach agree well with the experimental data. The amplitude of the pressure fluctuation in the vaneless space at turbine mode on a “S” curve increases with the decrease of the flow rate, and it has maximum value when it runs close to runaway line at turbine braking mode. The amplitude of the pressure fluctuation in the vaneless space at turbine braking mode on a “S” curve decreases with the reduce of the flow rate. The above high pressure fluctuations should be avoided during the design of pump turbines especially those operating at high-head condition.

  16. Tunable optical parametric generator based on the pump spatial walk-off.

    PubMed

    Cavanna, Andrea; Just, Felix; Sharapova, Polina R; Taheri, Michael; Leuchs, Gerd; Chekhova, Maria V

    2016-02-01

    We suggest a novel optical parametric generator (OPG) in which one of the downconverted beams is spontaneously generated along the Poynting vector of the pump beam. In this configuration, the generation takes advantage of the walk-off of the extraordinary pump, rather than being degraded by it. As a result, the generated signal and idler beams are bright due to a high conversion efficiency, spatially nearly single mode due to the preferred direction of the Poynting vector, tunable over a wide range of wavelengths and broadband. The two beams are also correlated in frequency and in the photon number per pulse. Furthermore, due to their thermal statistics, these beams can be used as a pump to efficiently generate other nonlinear processes. PMID:26907445

  17. Evaluation of 100G DP-QPSK long-haul transmission performance using second order co-pumped Raman laser based amplification.

    PubMed

    Tan, Mingming; Rosa, Paweł; Le, Son Thai; Phillips, Ian D; Harper, Paul

    2015-08-24

    We present, for the first time, a detailed investigation of the impact of second order co-propagating Raman pumping on long-haul 100G WDM DP-QPSK coherent transmission of up to 7082 km using Raman fibre laser based configurations. Signal power and noise distributions along the fibre for each pumping scheme were characterised both numerically and experimentally. Based on these pumping schemes, the Q factor penalties versus co-pump power ratios were experimentally measured and quantified. A significant Q factor penalty of up to 4.15 dB was observed after 1666 km using symmetric bidirectional pumping, compared with counter-pumping only. Our results show that whilst using co-pumping minimises the intra-cavity signal power variation and amplification noise, the Q factor penalty with co-pumping was too great for any advantage to be seen. The relative intensity noise (RIN) characteristics of the induced fibre laser and the output signal, and the intra-cavity RF spectra of the fibre laser are also presented. We attribute the Q factor degradation to RIN induced penalty due to RIN being transferred from the first order fibre laser and second order co-pump to the signal. More importantly, there were two different fibre lasing regimes contributing to the amplification. It was random distributed feedback lasing when using counter-pumping only and conventional Fabry-Perot cavity lasing when using all bidirectional pumping schemes. This also results in significantly different performances due to different laser cavity lengths for these two classes of laser.

  18. Optimizing wind pumps system for crop irrigation based on wind data processing

    NASA Astrophysics Data System (ADS)

    Ruiz, Fernando; Tarquis, Ana M.; Sanchez, Raúl; Garcia, Jose Luis

    2015-04-01

    Crop irrigation is a major consumer of energy that can be resolved with renewable ones, such as wind, which has experienced recent developments in the area of power generation. Therefore, wind power can play an interesting role in irrigation projects in different areas [1]. A simple methodology has been developed in previous papers for technical evaluation of windmills for irrigation water pumping [2]. This methodology can determine the feasibility of the technology and the levels of daily irrigation demand satisfied by windmills. The present work compared the possibilities of this methodology adjusting the three-hourly wind velocity to the Weibull II distribution function, without considering the time sequence [2], or processing wind data using time series analysis. The study was applied to practical cases of wind pumps for irrigation of crops, both in the outside (corn) and inside greenhouses (tomato). The analysis showed that the use of three hourly time series analysis supplied a more realistic modelling of the situation with a better optimization of the water storage tank of the wind pump facility taking into account the risk of calm periods in which the pumping is null. A factor to consider in this study is available precision of the wind sampling rate. References [1] Díaz-Méndez, R., Adnan Rasheed, M. Peillón, A. Perdigones, R. Sánchez, A.M. Tarquis, José L. García-Fernández. Wind pumps for irrigating greenhouse crops: comparison in different socio-economical frameworks. Biosystems Engineering, 128, 21-28, 2014. [2] Peillón, M., Sánchez, R., Tarquis, A.M., García, J.L. The use of wind pumps for greenhouse microirrigation: A case study for tomato in Cuba. Agricultural Water Management, 120, 107-114, 2013.

  19. Potential Coastal Pumped Hydroelectric Energy Storage Locations Identified using GIS-based Topographic Analysis

    NASA Astrophysics Data System (ADS)

    Parsons, R.; Barnhart, C. J.; Benson, S. M.

    2013-12-01

    Large-scale electrical energy storage could accommodate variable, weather dependent energy resources such as wind and solar. Pumped hydroelectric energy storage (PHS) and compressed energy storage area (CAES) have life cycle energy and financial costs that are an order of magnitude lower than conventional electrochemical storage technologies. However PHS and CAES storage technologies require specific geologic conditions. Conventional PHS requires an upper and lower reservoir separated by at least 100 m of head, but no more than 10 km in horizontal distance. Conventional PHS also impacts fresh water supplies, riparian ecosystems, and hydrologic environments. A PHS facility that uses the ocean as the lower reservoir benefits from a smaller footprint, minimal freshwater impact, and the potential to be located near off shore wind resources and population centers. Although technologically nascent, today one coastal PHS facility exists. The storage potential for coastal PHS is unknown. Can coastal PHS play a significant role in augmenting future power grids with a high faction of renewable energy supply? In this study we employ GIS-based topographic analysis to quantify the coastal PHS potential of several geographic locations, including California, Chile and Peru. We developed automated techniques that seek local topographic minima in 90 m spatial resolution shuttle radar topography mission (SRTM) digital elevation models (DEM) that satisfy the following criteria conducive to PHS: within 10 km from the sea; minimum elevation 150 m; maximum elevation 1000 m. Preliminary results suggest the global potential for coastal PHS could be very significant. For example, in northern Chile we have identified over 60 locations that satisfy the above criteria. Two of these locations could store over 10 million cubic meters of water or several GWh of energy. We plan to report a global database of candidate coastal PHS locations and to estimate their energy storage capacity.

  20. OSCILLATORY PUMP

    DOEpatents

    Underwood, N.

    1958-09-23

    This patent relates to a pump suitable fur pumping highly corrosive gases wherein no lubricant is needed in the pumping chamber thus eliminating possible contamination sources. The chamber contains a gas inlet and outlet in each side, with a paddle like piston suspended by a sylphon seal between these pcrts. An external arrangement causes the paddle to oscillate rapidly between the ports, alternately compressing and exhausting the gas trapped on each side of the paddle. Since the paddle does nnt touch the chamber sides at any point, no lubricant is required. This pump is useful for pumping large quantities of uranium hexafluorine.

  1. Champagne Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2004-01-01

    The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

  2. PUMP SETS NO. 5 AND NO. 4. Each pump set ...

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

    PUMP SETS NO. 5 AND NO. 4. Each pump set consists of a Worthington Pump and a General Electric motor - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Flame Deflector Water System, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  3. MEMS based pumped liquid cooling systems for micro/nano spacecraft thermal control

    NASA Technical Reports Server (NTRS)

    Birur, G. C.; Shakkottai, P.; Sur, T. W.

    2000-01-01

    The electronic and other payload power densities in future micro/nano spacecraft are expected to exceed 25 Watts/cm(sup 2) and require advanced thermal control concepts and technologies to keep their payload within allowable temperature limits. This paper presents background on the need for pumped liquid cooling systems for future micro/nano spacecraft and results from this ongoing experimental investigation.

  4. Dynamic Behavior of Reciprocating Plunger Pump Discharge Valve Based on Fluid Structure Interaction and Experimental Analysis.

    PubMed

    Wang, Guorong; Zhong, Lin; He, Xia; Lei, Zhongqing; Hu, Gang; Li, Rong; Wang, Yunhai

    2015-01-01

    The influence of spring stiffness and valve quality on the motion behaviors of reciprocating plunger pump discharge valves was investigated by fluid structure interaction (FSI) simulation and experimental analysis. The mathematical model of the discharge valve motion of a 2000-fracturing pump was developed and the discrete differential equations were solved according to FSI and results obtained by ANDINA software. Results indicate that spring stiffness influences the maximum lift, the opening resistance and shut-off lag angle, as well as the fluid velocity of the clearance, the impact stress and the volume efficiency of the pump valve in relation to the valve quality. An optimal spring stiffness parameter of 14.6 N/mm was obtained, and the volumetric efficiency of the pumping valve increased by 4‰ in comparison to results obtained with the original spring stiffness of 10.09N/mm. The experimental results indicated that the mathematical model and FSI method could provide an effective approach for the subsequent improvement of valve reliability, volumetric efficiency and lifespan. PMID:26488290

  5. Dynamic Behavior of Reciprocating Plunger Pump Discharge Valve Based on Fluid Structure Interaction and Experimental Analysis

    PubMed Central

    Wang, Guorong; Zhong, Lin; He, Xia; Lei, Zhongqing; Hu, Gang; Li, Rong; Wang, Yunhai

    2015-01-01

    The influence of spring stiffness and valve quality on the motion behaviors of reciprocating plunger pump discharge valves was investigated by fluid structure interaction (FSI) simulation and experimental analysis. The mathematical model of the discharge valve motion of a 2000-fracturing pump was developed and the discrete differential equations were solved according to FSI and results obtained by ANDINA software. Results indicate that spring stiffness influences the maximum lift, the opening resistance and shut-off lag angle, as well as the fluid velocity of the clearance, the impact stress and the volume efficiency of the pump valve in relation to the valve quality. An optimal spring stiffness parameter of 14.6 N/mm was obtained, and the volumetric efficiency of the pumping valve increased by 4‰ in comparison to results obtained with the original spring stiffness of 10.09N/mm. The experimental results indicated that the mathematical model and FSI method could provide an effective approach for the subsequent improvement of valve reliability, volumetric efficiency and lifespan. PMID:26488290

  6. All-optical logical gates based on pump-induced resonant nonlinearity in an erbium-doped fiber coupler.

    PubMed

    Li, Qiliang; Zhang, Zhen; Li, Dongqiang; Zhu, Mengyun; Tang, Xianghong; Li, Shuqin

    2014-12-01

    In this paper, we theoretically investigate all-optical logical gates based on the pump-induced resonant nonlinearity in an erbium-doped fiber coupler. The resonant nonlinearity yielded by the optical transitions between the (4)I(15/2) states and (4)I(13/2) states in Er(3+) induces the refractive index to change, which leads to switching between two output ports. First, we do a study on the switching performance, and calculate the extinction ratio (Xratio) of the device. Second, using the Xratio, we obtain the truth tables of the device. The results reveal that compared with other undoped nonlinear couplers, the erbium-doped fiber coupler can drop the switching threshold power. We also obtain different logic gates and logic operations in the cases of the same phase and different phase of two initial signals by changing the pump power.

  7. Yb fiber laser pumped mid-IR source based on difference frequency generation and its application to ammonia detection

    NASA Technical Reports Server (NTRS)

    Matsuoka, N.; Yamaguchi, S.; Nanri, K.; Fujioka, T.; Richter, D.; Tittel, F. K.

    2001-01-01

    A Yb fiber laser pumped cw narrow-linewidth tunable mid-IR source based on a difference frequency generation (DFG) in a periodically poled LiNbO3 (PPLN) crystal for trace gas detection was demonstrated. A high power Yb fiber laser and a distributed feedback (DFB) laser diode were used as DFG pump sources. This source generated mid-IR at 3 microns with a powers of 2.5 microW and a spectral linewidth of less than 30 MHz. A frequency tuning range of 300 GHz (10 cm-1) was obtained by varying the current and temperature of the DFB laser diode. A high-resolution NH3 absorption Doppler-broadened spectrum at 3295.4 cm-1 (3.0345 microns) was obtained at a cell pressure of 27 Pa from which a detection sensitivity of 24 ppm m was estimated.

  8. A power management system for energy harvesting and wireless sensor networks application based on a novel charge pump circuit

    NASA Astrophysics Data System (ADS)

    Aloulou, R.; De Peslouan, P.-O. Lucas; Mnif, H.; Alicalapa, F.; Luk, J. D. Lan Sun; Loulou, M.

    2016-05-01

    Energy Harvesting circuits are developed as an alternative solution to supply energy to autonomous sensor nodes in Wireless Sensor Networks. In this context, this paper presents a micro-power management system for multi energy sources based on a novel design of charge pump circuit to allow the total autonomy of self-powered sensors. This work proposes a low-voltage and high performance charge pump (CP) suitable for implementation in standard complementary metal oxide semiconductor (CMOS) technologies. The CP design was implemented using Cadence Virtuoso with AMS 0.35μm CMOS technology parameters. Its active area is 0.112 mm2. Consistent results were obtained between the measured findings of the chip testing and the simulation results. The circuit can operate with an 800 mV supply and generate a boosted output voltage of 2.835 V with 1 MHz as frequency.

  9. Yb fiber laser pumped mid-IR source based on difference frequency generation and its application to ammonia detection.

    PubMed

    Matsuoka, N; Yamaguchi, S; Nanri, K; Fujioka, T; Richter, D; Tittel, F K

    2001-02-01

    A Yb fiber laser pumped cw narrow-linewidth tunable mid-IR source based on a difference frequency generation (DFG) in a periodically poled LiNbO3 (PPLN) crystal for trace gas detection was demonstrated. A high power Yb fiber laser and a distributed feedback (DFB) laser diode were used as DFG pump sources. This source generated mid-IR at 3 microns with a powers of ~2.5 microW and a spectral linewidth of less than 30 MHz. A frequency tuning range of 300 GHz (10 cm-1) was obtained by varying the current and temperature of the DFB laser diode. A high-resolution NH3 absorption Doppler-broadened spectrum at 3295.4 cm-1 (3.0345 microns) was obtained at a cell pressure of 27 Pa from which a detection sensitivity of 24 ppm m was estimated. PMID:11676447

  10. Microfluidic pumping, routing and metering by contactless metal-based electro-osmosis.

    PubMed

    Fu, Xiaotong; Mavrogiannis, Nicholas; Doria, Steven; Gagnon, Zachary

    2015-09-01

    Over the past decade, many microfluidic platforms for fluid processing have been developed in order to perform on-chip fluidic manipulations. Many of these methods, however, require expensive and bulky external supporting equipment, which are not typically applicable for microsystems requiring portability. We have developed a new type of portable contactless metal electro-osmotic micropump capable of on-chip fluid pumping, routing and metering. The pump operates using two pairs of gallium metal electrodes, which are activated using an external voltage source, and separated from a main flow channel by a thin micron-scale PDMS membrane. The thin contactless membrane allows for field penetration and electro-osmotic (EO) flow within the microchannel, but eliminates electrode damage and sample contamination commonly associated with traditional DC electro-osmotic pumps that utilize electrodes in direct contact with the working fluid. The maximum flow rates and pressures generated by the pump using DI water as a working buffer are 10 nL min(-1) and 30 Pa, respectively. With our current design, the maximum operational conductivity where fluid flow is observed is 0.1 mS cm(-1). Due to the small size and simple fabrication procedure, multiple micropump units can be integrated into a single microfluidic device for automated on-chip routing and sample metering applications. We experimentally demonstrated the ability to quantify micropump electro-osmotic flowrate and pressure as a function of applied voltage, and developed a mathematical model capable of predicting the performance of a contactless micropump for a given external load and internal hydrodynamic microchannel resistance. Finally, we showed that by activating specific pumps within a microchannel network, our micropumps are capable of routing microchannel fluid flow and generating plugs of solute. PMID:26053965

  11. Intermittent chaos and sliding window symbol sequence statistics-based early fault diagnosis for hydraulic pump on hydraulic tube tester

    NASA Astrophysics Data System (ADS)

    Zhao, Zhen; Jia, Mingxing; Wang, Fuli; Wang, Shu

    2009-07-01

    To ensure the safety, continuity of production, make a reasonable maintenance plan, save the cost of maintenance for hydraulic tube tester, it is needed to quickly identify an assignable cause of a fault. This paper is concerned with early fault diagnosis of hydraulic pump which are the heart of hydraulic tube tester. Considering that the signal of the hydraulic pump early fault is a periodic weak signal, an intermittent chaos, sliding window symbol sequence statistics-based method is proposed to detect the early fault of one single piston loose shoes of hydraulic pump on a hydraulic tube tester. The approach presented is based on the insight that the phase transition of chaos oscillator, for example, the Duffing oscillator, is very sensitive to a periodic weak signal having little angular frequency difference with the referential signal of the oscillator. While observing the intermittent chaos phenomenon through figure is not easy for computer, a sliding window symbol sequence statistics is developed to realize real-time computer observation of this phenomenon. Rather more, this paper takes a trick to decreasing the computational complexity of the sliding window symbol sequence statistics method, also analyzes the influences of different window size, depths of the symbol tree on the information entropy. At last, a control limit is introduced to realize automatic early fault alarm. The resultant approach is experimented with data simulated from an AMESim model of hydraulic tube tester. The results indicate that the proposed approach is capable of detecting the signal of hydraulic pump early fault on hydraulic tube tester.

  12. Normetex Pump Alternatives Study

    SciTech Connect

    Clark, Elliot A.

    2013-04-25

    A mainstay pump for tritium systems, the Normetex scroll pump, is currently unavailable because the Normetex company went out of business. This pump was an all-metal scroll pump that served tritium processing facilities very well. Current tritium system operators are evaluating replacement pumps for the Normetex pump and for general used in tritium service. An all-metal equivalent alternative to the Normetex pump has not yet been identified. 1. The ideal replacement tritium pump would be hermetically sealed and contain no polymer components or oils. Polymers and oils degrade over time when they contact ionizing radiation. 2. Halogenated polymers (containing fluorine, chlorine, or both) and oils are commonly found in pumps. These materials have many properties that surpass those of hydrocarbon-based polymers and oils, including thermal stability (higher operating temperature) and better chemical resistance. Unfortunately, they are less resistant to degradation from ionizing radiation than hydrocarbon-based materials (in general). 3. Polymers and oils can form gaseous, condensable (HF, TF), liquid, and solid species when exposed to ionizing radiation. For example, halogenated polymers form HF and HCl, which are extremely corrosive upon reaction with water. If a pump containing polymers or oils must be used in a tritium system, the system must be designed to be able to process the unwanted by-products. Design features to mitigate degradation products include filters and chemical or physical traps (eg. cold traps, oil traps). 4. Polymer components can work in tritium systems, but must be replaced regularly. Polymer components performance should be monitored or be regularly tested, and regular replacement of components should be viewed as an expected normal event. A radioactive waste stream must be established to dispose of used polymer components and oil with an approved disposal plan developed based on the facility location and its regulators. Polymers have varying

  13. Qualification Testing of Laser Diode Pump Arrays for a Space-Based 2-micron Coherent Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Singh, Upendra N.; Kavaya, Michael J.

    2007-01-01

    The 2-micron thulium and holmium-based lasers being considered as the transmitter source for space-based coherent Doppler lidar require high power laser diode pump arrays operating in a long pulse regime of about 1 msec. Operating laser diode arrays over such long pulses drastically impact their useful lifetime due to the excessive localized heating and substantial pulse-to-pulse thermal cycling of their active regions. This paper describes the long pulse performance of laser diode arrays and their critical thermal characteristics. A viable approach is then offered that allows for determining the optimum operational parameters leading to the maximum attainable lifetime.

  14. Prospects for diode-pumped alkali-atom-based hollow-core photonic-crystal fiber lasers.

    PubMed

    Sintov, Yoav; Malka, Dror; Zalevsky, Zeev

    2014-08-15

    By employing large hollow-core Kagome fiber in a double-clad configuration, the performance of a potentially rubidium vapor-based fiber laser is explored. The absorbed power and laser efficiency versus pump power are calculated utilizing a simple laser model. Our results show that a Kagome-based high-power fiber laser is feasible provided that the value of the collisional fine-structure mixing rate will be elevated by increasing the ambient temperature or by increasing the helium pressure.

  15. A compact diode-pumped pulsed Nd:YAG slab laser based on a master oscillator power amplifier configuration

    NASA Astrophysics Data System (ADS)

    Maleki, A.; Kavosh Tehrani, M.; Saghafifar, H.; Moghtader Dindarlu, M. H.; Ebadian, H.

    2016-02-01

    In this paper, the design and construction of a pulsed Nd:YAG laser is described. The structure of this laser is based on a master oscillator power amplifier system. A master oscillator is an electro-optical Q-switched Nd:YAG rod laser. Face-pumping is used for the excitation of the slab structure, and a double-pass method is designed for the amplification stages. Two Nd:YAG zigzag slabs are utilized as power amplification stages in this laser. The laser diodes are stacked in a compact configuration and are used for rod and slabs pumping. The total pump energy in the amplifier stages is 3200 mJ at 808 nm. The output pulse energy achieved at 1064 nm is about 850 mJ of 10 ns pulse duration corresponding to 26.5% optical-to-optical conversion efficiency. Moreover, this laser can generate pulse energies around 430 mJ at 532 nm. The dependence of the output energy of MOPA and second harmonic generation operations on different pulse repetition rates (PRRs) from 1 to 100 Hz has been investigated. Experimental results show that the maximum fluctuations of the output energies are about 2.5 and 4% for 1064 and 532 nm, respectively.

  16. In situ monitoring of atmospheric nitrous acid based on multi-pumping flow system and liquid waveguide capillary cell.

    PubMed

    Liu, Yuhan; Lu, Keding; Dong, Huabin; Li, Xin; Cheng, Peng; Zou, Qi; Wu, Yusheng; Liu, Xingang; Zhang, Yuanhang

    2016-05-01

    In the last four decades, various techniques including spectroscopic, wet chemical and mass spectrometric methods, have been developed and applied for the detection of ambient nitrous acid (HONO). We developed a HONO detection system based on long path photometry which consists of three independent modules i.e., sampling module, fluid propulsion module and detection module. In the propulsion module, solenoid pumps are applied. With solenoid pumps the pulsed flow can be computer controlled both in terms of pump stroke volume and pulse frequency, which enables the attainment of a very stable flow rate. In the detection module, a customized Liquid Waveguide Capillary Cell (LWCC) is used. The customized LWCC pre-sets the optical fiber in-coupling with the liquid wave guide, providing the option of fast startup and easy maintenance of the absorption photometry. In summer 2014, our system was deployed in a comprehensive campaign at a rural site in the North China Plain. More than one month of high quality HONO data spanning from the limit of detection to 5ppb were collected. Intercomparison of our system with another established system from Forschungszentrum Juelich is presented and discussed. In conclusion, our instrument achieved a detection limit of 10pptV within 2min and a measurement uncertainty of 7%, which is well suited for investigation of the HONO budget from urban to rural conditions in China. PMID:27155434

  17. Insulin pumps.

    PubMed

    Pickup, J

    2010-02-01

    Insulin pump therapy is now more than 30 years old, and is an established part of the routine care of selected people with type 1 diabetes. Nevertheless, there are still significant areas of concern, particularly how pumps compare with modern injection therapy, whether the increasingly sophisticated pump technologies like onboard calculators and facility for computer download offer any real benefit, and whether we have a consensus on the clinical indications. The following papers offer some insight into these and other current questions.

  18. Silicon microring-based wavelength converter with integrated pump and signal suppression.

    PubMed

    Ong, Jun Rong; Kumar, Ranjeet; Mookherjea, Shayan

    2014-08-01

    We fabricate a two-stage wavelength converter in silicon by cascading a microring wavelength mixer with a five-ring coupled-resonator filter. A p-i-n diode is incorporated into the microring for electronic carrier sweep-out, and microheaters are incorporated into the filter for tunability. The generated idler wavelength is effectively separated from the input pump and signal, with nearly 50 dB of suppression.

  19. A robust controller for insulin pumps based on H-infinity theory.

    PubMed

    Kienitz, K H; Yoneyama, T

    1993-11-01

    The feedback control of insulin pumps for diabetic patients is discussed. Because the parameters in the mathematical model of the blood glucose dynamics present a considerable amount of uncertainty, the H-infinity framework is well suited for the design of controllers that take into account a nice compromise between robust closed-loop regulation of a constant set point and performance expressed in terms of peak values of the plasma glucose concentration.

  20. Space rocket engine on the base of the reactor-pumped laser for the interplanetary flights and earth orbital applications

    NASA Astrophysics Data System (ADS)

    Gulevich, Andrey V.; Dyachenko, Peter P.; Kukharchuk, Oleg F.; Zrodnikov, Anatoly V.

    2000-01-01

    In this report the concept of vehicle-based reactor-laser engine for long time interplanetary and interorbital (LEO to GEO) flights is proposed. Reactor-pumped lasers offer the perspective way to create on the base of modern nuclear and lasers technologies the low mass and high energy density, repetitively pulsed vehicle-based laser of average power 100 kW. Nowadays the efficiency of nuclear-to-optical energy conversion reached the value of 2-3%. The demo model of reactor-pumped laser facility is under construction in Institute for Physics and Power Engineering (Obninsk, Russia). It enable us to hope that using high power laser on board of the vehicle could make the effective space laser engine possible. Such engine may provide the high specific impulse ~1000-2000 s with the thrust up to 10-100 n. Some calculation results of the characteristics of vehicle-based reactor-laser thermal engine concept are also presented. .

  1. High-power efficient cw and pulsed lasers based on bulk Yb : KYW crystals with end diode pumping

    SciTech Connect

    Kim, G H; Yang, G H; Lee, D S; Kulik, Alexander V; Sall', E G; Chizhov, S A; Yashin, V E; Kang, U

    2012-04-30

    End-diode-pumped lasers based on one and two Yb : KYW crystals operating in cw and Q-switched regimes, as well as in the regime of mode-locking, are studied. The single-crystal laser generated stable ultrashort (shorter than 100 fs) laser pulses at wavelengths of 1035 and 1043 nm with an average power exceeding 1 W. The average output power of the two-crystal laser exceeded 18 W in the cw regime and 16 W in the Q-switched regime with a slope efficiency exceeding 30%.

  2. Use of expert judgment in the development and evaluation of risk-based inservice testing strategies for pumps and valves

    SciTech Connect

    McAllister, W.J.; Perdue, R.K.; Balkey, K.R.; Closky, N.B.

    1996-12-01

    This paper describes a rigorous approach for quantitatively evaluating inservice testing effectiveness that evolved from two pilot plant studies. These studies prototyped methodologies for designing and selecting inservice testing (IST) strategies in a manner structured to insure that the targeted components will perform their required safety functions while minimizing life cycle inservice testing costs. The paper concentrates on the use of expert judgment in developing test effectiveness measures that move risk-based methods beyond ranking to optimization of plant IST programs. Selected results for check valves and pumps are shown to illustrate the practical significance of the approach.

  3. Ferroelectric Pump

    NASA Technical Reports Server (NTRS)

    Jalink, Antony, Jr. (Inventor); Hellbaum, Richard F. (Inventor); Rohrbach, Wayne W. (Inventor)

    2000-01-01

    A ferroelectric pump has one or more variable volume pumping chambers internal to a housing. Each chamber has at least one wall comprising a dome shaped internally prestressed ferroelectric actuator having a curvature and a dome height that varies with an electric voltage applied between an inside and outside surface of the actuator. A pumped medium flows into and out of each pumping chamber in response to displacement of the ferroelectric actuator. The ferroelectric actuator is mounted within each wall and isolates each ferroelectric actuator from the pumped medium, supplies a path for voltage to be applied to each ferroelectric actuator, and provides for positive containment of each ferroelectric actuator while allowing displacement of the entirety of each ferroelectric actuator in response to the applied voltage.

  4. Axial Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  5. RENEWABLE LIQUID GETTERING PUMP

    DOEpatents

    Batzer, T.H.

    1962-08-21

    A method and structure were developed for pumping gases by simple absorption into a liquid gettering material. The invention comprises means ror continuously pumping a liquid getterrng material from a reservoir to the top of a generally vertical surface disposed in a vacuum pumping chamber to receive gaseous and other particles in the liquid gettering material which continuously flows downward over the vertical suiface. Means are provided for continuous removal, degassing, and return of a portion of the liquid gettering material from the reservoir connected with collectrng means at the base of the generally vertical plate. (AEC)

  6. Diode laser pumped green light source based on intracavity sum frequency generation

    NASA Astrophysics Data System (ADS)

    Fu, X. H.; Che, Y.; Li, Y. L.; Jiang, H. L.

    2011-07-01

    We report a continuous-wave (CW) green laser emission by sum-frequency mixing in Nd:GdVO4 and Nd:YLF crystals. Using type-I critical phase-matching (CPM) LBO crystal, a green laser at 538 nm is obtained by 912 and 1313 nm intracavity sum-frequency mixing. The maximum output power of 185 mW is obtained when an incident pump laser of 18.2 W is used. At the output power level of 185 mW, the output stability is better than 3.3%.

  7. Power scaling of a side-pumped Nd:YLF laser based on DBMC technology

    NASA Astrophysics Data System (ADS)

    Wetter, Niklaus U.; Deana, Alessandro M.

    2014-12-01

    This work demonstrates the power scalability of double-beam-mode controlling, a technique that has generated the highest optical efficiency reported so far for Nd:YLF lasers. We analyze two types of power scaling possibilities by numerical simulations: multiplication of intracavity pump modules and MOPA configuration. About 44 W of TEM00 output power at 1053 nm was experimentally demonstrated with a beam-parameter product of 1.07 × 1.15. The results show great ease of power scaling without sacrificing beam quality.

  8. Bidirectional Wavelength Reconfigurable Module Based on Tunable Fiber Bragg Grating and Remote Pump Amplifier

    NASA Astrophysics Data System (ADS)

    Yu, Yi-Lin; Liaw, Shien-Kuei; Skaljo, Edvin; Le Minh, Hoa; Ghassemlooy, Zabih

    2014-09-01

    This article presents a novel bidirectional wavelength reconfigurable optical network utilizing a remotely pumped erbium-doped fiber amplifier and tunable fiber Bragg gratings. The system is experimentally demonstrated at a 10-Gb/s per channel over 20-km fiber span that verifies the metro-network range system performance. The achieved power penalty is less than 1 dB when compared to the back-to-back transmission link. An example of practical application where the proposed module is used as an add/drop multiplexer and a remote node in the bidirectional wavelength division multiplexing passive optical network system is described.

  9. Evidence-based assessment of proton-pump inhibitors in Helicobacter pylori eradication: A systematic review

    PubMed Central

    Nagaraja, Vinayak; Eslick, Guy D

    2014-01-01

    Peptic ulcer disease continues to be issue especially due to its high prevalence in the developing world. Helicobacter pylori (H. pylori) infection associated duodenal ulcers should undergo eradication therapy. There are many regimens offered for H. pylori eradication which include triple, quadruple, or sequential therapy regimens. The central aim of this systematic review is to evaluate the evidence for H. pylori therapy from a meta-analytical outlook. The consequence of the dose, type of proton-pump inhibitor, and the length of the treatment will be debated. The most important risk factor for eradication failure is resistance to clarithromycin and metronidazole. PMID:25356018

  10. Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Woo; Wang, K. W.

    2009-08-01

    In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT 1\\to 2 up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements.

  11. Design and Analysis of a Getter-Based Vacuum Pumping System for a Rocket-Borne Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Everett, E. A.; Syrstad, E. A.; Dyer, J. S.

    2010-12-01

    The mesosphere / lower thermosphere (MLT) is a transition region where the turbulent mixing of earth’s lower atmosphere gives way to the molecular diffusion of space. This region hosts a rich array of chemical processes and atmospheric phenomena, and serves to collect and distribute particles of all sizes in thin layers. Spatially resolved in situ characterization of these layers is very difficult, due to the elevated pressure of the MLT, limited access via high-speed sounding rockets, and the enormous variety of charged and neutral species that range in size from atoms to smoke and dust particles. In terrestrial applications, time-of-flight mass spectrometry (TOF-MS) is the technique of choice for performing fast, sensitive composition measurements with extremely large mass range. However, because of its reliance on high voltages and microchannel plate (MCP) detectors prone to discharge at elevated pressures, TOF-MS has rarely been employed for measurements of the MLT, where ambient pressures approach 10 mTorr. We present a novel, compact mass spectrometer design appropriate for deployment aboard sounding rockets. This Hadamard transform time-of-flight mass spectrometer (HT-TOF-MS) applies a multiplexing technique through pseudorandom beam modulation and spectral deconvolution to achieve very high measurement duty cycles (50%), with a theoretically unlimited mass range. The HT-TOF-MS employs a simple, getter-based vacuum pumping system and pressure-tolerant MCP to allow operation in the MLT. The HT-TOF-MS must provide sufficient vacuum pumping to 1) maintain a minimum mean free path inside the instrument, to avoid spectral resolution loss, and 2) to avoid MCP failure through electrostatic discharge. The design incorporates inexpensive, room temperature tube getters loaded with nano-structured barium to meet these pumping speed requirements, without the use of cryogenics or mechanical pumping systems. We present experimental results for gettering rates and

  12. Stochastic pumping of ions based on colored noise in bacterial channels under acidic stress

    NASA Astrophysics Data System (ADS)

    López, M. Lidón; Queralt-Martín, María; Alcaraz, Antonio

    2016-07-01

    Fluctuation-driven ion transport can be obtained in bacterial channels with the aid of different types of colored noise including the biologically relevant Lorentzian one. Using the electrochemical rectification of the channel current as a ratchet mechanism we observe transport of ions up to their concentration gradient under conditions similar to that met in vivo, namely moderate pH gradients and asymmetrically charged lipid membranes. We find that depending on the direction of the concentration gradient the channel can pump either cations or anions from the diluted side to the concentrated one. We discuss the possible relevance of this phenomenon for the pH homeostasis of bacterial cells.Fluctuation-driven ion transport can be obtained in bacterial channels with the aid of different types of colored noise including the biologically relevant Lorentzian one. Using the electrochemical rectification of the channel current as a ratchet mechanism we observe transport of ions up to their concentration gradient under conditions similar to that met in vivo, namely moderate pH gradients and asymmetrically charged lipid membranes. We find that depending on the direction of the concentration gradient the channel can pump either cations or anions from the diluted side to the concentrated one. We discuss the possible relevance of this phenomenon for the pH homeostasis of bacterial cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02638a

  13. Analysis of a 10 megawatt space-based solar-pumped neodymium laser system

    NASA Technical Reports Server (NTRS)

    Kurweg, U. H.

    1984-01-01

    A ten megawatt solar-pumped continuous liquid laser system for space applications is examined. It is found that a single inflatable mirror of 434 m diameter used in conjunction with a conical secondary concentrator is sufficient to side pump a liquid neodymium lasant in an annular tube of 6 m length and 1 m outer and 0.8 m inner diameter. About one fourth of intercepted radiation converging on the laser tube is absorbed and one fifth of this radiation is effective in populating the upper levels. The liquid lasant is flowed through the annular laser cavity at 1.9 m/s and is cooled via a heat exchanger and a large radiator surface comparable in size to the concentrating mirror. The power density of incident light within the lasant of approximately 68 watt/cu cm required for cw operation is exceeded in the present annular configuration. Total system weight corresponds to 20,500 kg and is thus capable of being transported to near Earth orbit by a single shuttle flight.

  14. The pump parameters optimization in LDA pumped solid-state laser

    NASA Astrophysics Data System (ADS)

    Han, Yaofeng; Zhang, Ruofan; Yang, Hongru

    2015-02-01

    Based on the propagation of Gaussian light, Zemax program is used to simulate the pump light propagating process and absorbing distribution for LDA side-pump laser rod,and the corresponding heat load distribution analysis of the rod is done by using Lascad program.On the basis of simulation results,the pump parameters of LDA side-pump Nd:YAG are optimized which provide valuable guidances for side-pump LDA designing and pump module engineering.

  15. Submersible pump

    SciTech Connect

    Todd, D. B.

    1985-08-27

    A method and apparatus for using a submersible pump to lift reservoir fluids in a well while having the tubing/casing annulus isolated from the produced fluids. The apparatus allows the submersible pump to be positioned above the annular packoff device. The apparatus comprises an outer shield that encloses the pump and can be attached to the production tubing. The lower end of the shield attaches to a short tubing section that seals with the annular packoff device or a receptacle above the annular packoff device.

  16. Direct electro-optical pumping for hybrid CdSe nanocrystal/III-nitride based nano-light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Mikulics, M.; Arango, Y. C.; Winden, A.; Adam, R.; Hardtdegen, A.; Grützmacher, D.; Plinski, E.; Gregušová, D.; Novák, J.; Kordoš, P.; Moonshiram, A.; Marso, M.; Sofer, Z.; Lüth, H.; Hardtdegen, H.

    2016-02-01

    We propose a device concept for a hybrid nanocrystal/III-nitride based nano-LED. Our approach is based on the direct electro-optical pumping of nanocrystals (secondary excitation) by electrically driven InGaN/GaN nano-LEDs as the primary excitation source. To this end, a universal hybrid optoelectronic platform was developed for a large range of optically active nano- and mesoscopic structures. The advantage of the approach is that the emission of the nanocrystals can be electrically induced without the need of contacting them. The proof of principal was demonstrated for the electro-optical pumping of CdSe nanocrystals. The nano-LEDs with a diameter of 100 nm exhibit a very low current of ˜8 nA at 5 V bias which is several orders of magnitude smaller than for those conventionally used. The leakage currents in the device layout were typically in the range of 8 pA to 20 pA/cm2 at 5 V bias. The photon-photon down conversion efficiency was determined to be 27%. Microphotoluminescence and microelectroluminescence characterization demonstrate the potential for future optoelectronics and highly secure "green" information technology applications.

  17. In vivo performance evaluation and establishment of IVIVC for osmotic pump based extended release formulation of milnacipran HCl.

    PubMed

    Parejiya, Punit B; Barot, Bhavesh S; Patel, Hetal K; Chorawala, Mehul R; Shelat, Pragna K; Shukla, Arunkumar

    2013-05-01

    The objective of the present study was to carry out a pharmacokinetics evaluation of an oral modified release formulation [Aquarius EKX 19102 SRX-2 based osmotic pump (OP)] containing highly soluble milnacipran HCl (MH) as a model drug. It was also aimed at developing an in vitro-in vivo correlation (IVIVC) model for a developed OP. In vivo plasma concentration data were obtained from six healthy male New Zealand albino rabbits after administration of immediate-release milnacipran HCl solution (IRMHSOL) and milnacipran HCl osmotic pump (MHOP). In vitro samples were analysed using an in house developed spectrophotometry method and in vivo samples were analysed using a RP-HPLC method developed by the author. A deconvolution based Level A model was attempted through a correlation of the percent in vivo input obtained through deconvolution and the percent in vitro dissolution obtained experimentally. A good correlation between the percentages dissolved vs absorbed (R(2) = 0.978) was obtained using level A correlation. Evaluation of the internal predictability of level A correlation was calculated in terms of the percent prediction error, which was found to be below 15%. In a nutshell, the success of the present study warrants further studies in patient volunteers to assess the ability of the MHOP to provide an effective therapy for depression. PMID:23463628

  18. Fiber-laser-based, green-pumped, picosecond optical parametric oscillator using fan-out grating PPKTP.

    PubMed

    Chaitanya Kumar, S; Parsa, S; Ebrahim-Zadeh, M

    2016-01-01

    We report a stable, Yb-fiber-laser-based, green-pumped, picosecond optical parametric oscillator (OPO) for the near-infrared based on periodically poled potassium titanyl phosphate (PPKTP) nonlinear crystal, using fan-out grating design and operating near room temperature. The OPO is continuously tunable across 726-955 nm in the signal and 1201-1998 nm in the idler, resulting in a total signal plus idler wavelength coverage of 1026 nm by grating tuning at a fixed temperature. The device generates up to 580 mW of average power in the signal at 765 nm and 300 mW in the idler at 1338 nm, with an overall extraction efficiency of up to 52% and a pump depletion >76%. The extracted signal at 765 nm and idler at 1746 nm exhibit excellent passive power stability better than 0.5% and 0.8% rms, respectively, over 1 h with good beam quality in TEM00 mode profile. The output signal pulses have a Gaussian temporal duration of 13.2 ps, with a FWHM spectral bandwidth of 3.4 nm at 79.5 MHz repetition rate. Power scaling limitations of the OPO due to the material properties of PPKTP are studied.

  19. Fiber-laser-based, green-pumped, picosecond optical parametric oscillator using fan-out grating PPKTP.

    PubMed

    Chaitanya Kumar, S; Parsa, S; Ebrahim-Zadeh, M

    2016-01-01

    We report a stable, Yb-fiber-laser-based, green-pumped, picosecond optical parametric oscillator (OPO) for the near-infrared based on periodically poled potassium titanyl phosphate (PPKTP) nonlinear crystal, using fan-out grating design and operating near room temperature. The OPO is continuously tunable across 726-955 nm in the signal and 1201-1998 nm in the idler, resulting in a total signal plus idler wavelength coverage of 1026 nm by grating tuning at a fixed temperature. The device generates up to 580 mW of average power in the signal at 765 nm and 300 mW in the idler at 1338 nm, with an overall extraction efficiency of up to 52% and a pump depletion >76%. The extracted signal at 765 nm and idler at 1746 nm exhibit excellent passive power stability better than 0.5% and 0.8% rms, respectively, over 1 h with good beam quality in TEM00 mode profile. The output signal pulses have a Gaussian temporal duration of 13.2 ps, with a FWHM spectral bandwidth of 3.4 nm at 79.5 MHz repetition rate. Power scaling limitations of the OPO due to the material properties of PPKTP are studied. PMID:26696156

  20. ION PUMP

    DOEpatents

    Milleron, N.

    1961-01-01

    An ion pump and pumping method are given for low vacuum pressures in which gases introduced into a pumping cavity are ionized and thereafter directed and accelerated into a quantity of liquid gettering metal where they are absorbed. In the preferred embodiment the metal is disposed as a liquid pool upon one electrode of a Phillips ion gauge type pump. Means are provided for continuously and remotely withdrawing and degassing the gettering metal. The liquid gettering metal may be heated if desired, although various combinations of gallium, indium, tin, bismuth, and lead, the preferred metals, have very low melting points. A background pressure of evaporated gettering metal may be provided by means of a resistance heated refractory metal wick protruding from the surface of the pcol of gettering metal.

  1. Electrokinetic pump

    DOEpatents

    Patel, Kamlesh D.

    2007-11-20

    A method for altering the surface properties of a particle bed. In application, the method pertains particularly to an electrokinetic pump configuration where nanoparticles are bonded to the surface of the stationary phase to alter the surface properties of the stationary phase including the surface area and/or the zeta potential and thus improve the efficiency and operating range of these pumps. By functionalizing the nanoparticles to change the zeta potential the electrokinetic pump is rendered capable of operating with working fluids having pH values that can range from 2-10 generally and acidic working fluids in particular. For applications in which the pump is intended to handle highly acidic solutions latex nanoparticles that are quaternary amine functionalized can be used.

  2. Ultrafast pump-probe dynamics of iron oxide based earth pigments for applications to ancient pottery manufacture

    NASA Astrophysics Data System (ADS)

    Villafana, Tana E.; Brown, William; Warren, Warren S.; Fischer, Martin

    2015-06-01

    We demonstrate that ultrafast pump-probe microscopy provides unique dynamics for natural iron oxide and iron hydroxide earth pigments, despite their chemical similarity. First, we conducted a pump-probe spectroscopy study on heat-treated hematite (the pure red iron oxide mineral) and found the pump-probe dynamics to be temperature dependent. Second, we investigated pottery fired under known conditions and observed firing dependent pump-probe dynamics. Finally, we imaged a New World potshard from the North Carolina Museum of Art. Our results indicate that pump-probe microscopy could be a useful tool in elucidating pottery manufacture.

  3. Variable stiffness actuator based on fluidic flexible matrix composites and piezoelectric-hydraulic pump

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Woo; Li, Suyi; Wang, K. W.

    2010-04-01

    Recently, a new biological-inspired fluidic flexible matrix composite (in short, F2MC) concept has been developed for linear/torsional actuation and structural stiffness tailoring. Although the actuation and the variable stiffness features of the F2MC have been successfully demonstrated individually, their combined functions and full potentials were not yet manifested. In addition, the current hydraulic pressurization systems are bulky and heavy, limiting the potential of the F2MC actuator. To address these issues, we synthesize a new variable stiffness actuator concept that can provide both effective actuation and tunable stiffness (dual-mode), incorporating the F2MC with a compact piezoelectric-hydraulic pump (in short, PHP). This dual-mode mechanism will significantly enhance the potential of the F2MC adaptive structures.

  4. Heat Pump Water Heater Technology Assessment Based on Laboratory Research and Energy Simulation Models: Preprint

    SciTech Connect

    Hudon, K.; Sparn, B.; Christensen, D.; Maguire, J.

    2012-02-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. Laboratory results demonstrate the efficiency of this technology under most of the conditions tested and show that differences in control schemes and design features impact the performance of the individual units. These results were used to understand current model limitations, and then to bracket the energy savings potential for HPWH technology in various US climate regions. Simulation results show that HPWHs are expected to provide significant energy savings in many climate zones when compared to other types of water heaters (up to 64%, including impact on HVAC systems).

  5. Hydraulic performance improvement of the bidirectional pit pump installation based on CFD

    NASA Astrophysics Data System (ADS)

    Chen, H. X.; Zhou, D. Q.

    2013-12-01

    At present, the efficiency of bidirectional pit pump installation with lift under 2m is still low because of lack of research on it in the past. In the paper, the CFD numerical method and experimental test were applied to study flow characteristic of bidirectional pit pump installation under positive and reverse condition. Through changing airfoil type and position of blade and stay vane, the comprehensive performance of improved model were obtained by calculating many different models. The results showed that when improved model is obtained with type A runner with 4 blades that is 0.7D away from pit exit and unsymmetrical guide vane 0.25dh which away from the impeller outlet, and the flow pattern of the improved solution is steady with high efficiency. Compared with the original scheme, the efficiency of positive and reverse design condition reach to 67.23% and 58.32% respectively, which is increased 6% more than original model on the design condition and 5% on the optimum operating condition, and it achieved the purpose of improvement. According to the runner blade angle of the optimization solution, model synthetic characteristic curve was drawn and internal flow field characteristics was analyzed under optimal positive and reverse conditions. The numerical calculation shows that owing to the lack of stay vane to recycle the energy in outlet runner chamber, the water flow regime is not steady enough in the outlet passage, and that is the main reason for lower efficiency at reverse condition than that at positive condition.

  6. Charge pump-based MOSFET-only 1.5-bit pipelined ADC stage in digital CMOS technology

    NASA Astrophysics Data System (ADS)

    Singh, Anil; Agarwal, Alpana

    2016-10-01

    A simple low-power and low-area metal-oxide-semiconductor field-effect transistor-only fully differential 1.5-bit pipelined analog-to-digital converter stage is proposed and designed in Taiwan Semiconductor Manufacturing Company 0.18 μm-technology using BSIM3v3 parameters with supply voltage of 1.8 V in inexpensive digital complementary metal-oxide semiconductor (CMOS) technology. It is based on charge pump technique to achieve the desired voltage gain of 2, independent of capacitor mismatch and avoiding the need of power hungry operational amplifier-based architecture to reduce the power, Si area and cost. Various capacitances are implemented by metal-oxide semiconductor capacitors, offering compatibility with cheaper digital CMOS process in order to reduce the much required manufacturing cost.

  7. High-energy kHz mid-IR tunable PPSLT-based OPO pumped at 1064 nm

    SciTech Connect

    Gaydardzhiev, A; Chuchumishev, D; Draganov, D; Buchvarov, I

    2012-06-30

    We report a single-frequency sub-nanosecond optical parametric oscillator (OPO) based on periodically poled stoichiometric lithium tantalate (PPSLT), pumped by a 1064-nm amplified microchip laser at a repetition rate of 0.5 kHz. Using a 11-mm-long PPSLT crystal polled with three different domain periods (30.2, 30.3, 30.4 {mu}m) and changing the temperature of the crystal from 20 Degree-Sign C to 265 Degree-Sign C, we have achieved wavelength tuning between 2990 nm and 3500 nm. The high nonlinearity of the used medium and the large aperture (2 mm) ensure the maximum idler output energy of {approx}0.5 mJ in the whole tuning range, corresponding to average {approx}10.5 % idler conversion efficiency and {approx}250 mW of average power. Sub-nanosecond pulse durations have been obtained for the idler at 0.88-ns pulse duration of the pump.

  8. 100 mW deep-ultraviolet emission from aluminium-nitride-based quantum wells pumped by an electron beam

    NASA Astrophysics Data System (ADS)

    Oto, Takao; Banal, Ryan G.; Kataoka, Ken; Funato, Mitsuru; Kawakami, Yoichi

    2010-11-01

    Ultraviolet light sources, represented by excimer and mercury lamps, are currently used for various applications, including water purification/sterilization, biotechnology, photolithography and surface modification. However, they have the disadvantages of limited portability, low emission efficiency and the presence of harmful constituents. Finding a compact, efficient and environmentally friendly alternative ultraviolet light source is therefore of considerable technological interest. Aluminium-nitride-based semiconductors show promise as materials for this purpose, but because of difficulties in controlling electronic conductivity, in light-emitting diodes are hampered by low external quantum efficiencies. Here, we use an electron-beam pumping technique, demonstrating an output of 100 mW and a record power efficiency of ~40% from AlxGa1-xN/AlN quantum wells emitting at ~240 nm. This achievement is attributed to carrier confinement within the high-quality quantum wells, as well as the appropriate design of sample structures for electron-beam pumping, and may be a milestone in the path to realizing next-generation ultraviolet light sources with great ecological and economic benefits.

  9. Hydrogen-bonding alterations of the protonated Schiff base and water molecule in the chloride pump of Natronobacterium pharaonis.

    PubMed

    Shibata, Mikihiro; Muneda, Norikazu; Sasaki, Takanori; Shimono, Kazumi; Kamo, Naoki; Demura, Makoto; Kandori, Hideki

    2005-09-20

    Halorhodopsin is a light-driven chloride ion pump. Chloride ion is bound in the Schiff base region of the retinal chromophore, and unidirectional chloride transport is probably enforced by the specific hydrogen-bonding interaction with the protonated Schiff base and internal water molecules. In this article, we study hydrogen-bonding alterations of the Schiff base and water molecules in halorhodopsin of Natronobacterium pharaonis (pHR) by assigning their N-D and O-D stretching vibrations in D(2)O, respectively. Highly accurate low-temperature Fourier transform infrared spectroscopy revealed that hydrogen bonds of the Schiff base and water molecules are weak in the unphotolyzed state, whereas they are strengthened upon retinal photoisomerization. Halide dependence of the stretching vibrations enabled us to conclude that the Schiff base forms a direct hydrogen bond with Cl(-) only in the K intermediate. Hydrogen bond of the Schiff base is further strengthened in the L(1) intermediate, whereas the halide dependence revealed that the acceptor is not Cl(-), but presumably a water molecule. Thus, it is concluded that the hydrogen-bonding interaction between the Schiff base and Cl(-) is not a driving force of the motion of Cl(-). Rather, the removal of its hydrogen bonds with the Schiff base and water(s) makes the environment around Cl(-) less polar in the L(1) intermediate, which presumably drives the motion of Cl(-) from its binding site to the cytoplasmic domain.

  10. Optimizations of spin-exchange relaxation-free magnetometer based on potassium and rubidium hybrid optical pumping

    SciTech Connect

    Fang, Jiancheng; Wang, Tao Li, Yang; Zhang, Hong; Zou, Sheng

    2014-12-15

    The hybrid optical pumping atomic magnetometers have not realized its theoretical sensitivity, the optimization is critical for optimal performance. The optimizations proposed in this paper are suitable for hybrid optical pumping atomic magnetometer, which contains two alkali species. To optimize the parameters, the dynamic equations of spin evolution with two alkali species were solved, whose steady-state solution is used to optimize the parameters. The demand of the power of the pump beam is large for hybrid optical pumping. Moreover, the sensitivity of the hybrid optical pumping magnetometer increases with the increase of the power density of the pump beam. The density ratio between the two alkali species is especially important for hybrid optical pumping magnetometer. A simple expression for optimizing the density ratio is proposed in this paper, which can help to determine the mole faction of the alkali atoms in fabricating the hybrid cell before the cell is sealed. The spin-exchange rate between the two alkali species is proportional to the saturated density of the alkali vapor, which is highly dependent on the temperature of the cell. Consequently, the sensitivity of the hybrid optical pumping magnetometer is dependent on the temperature of the cell. We proposed the thermal optimization of the hybrid cell for a hybrid optical pumping magnetometer, which can improve the sensitivity especially when the power of the pump beam is low. With these optimizations, a sensitivity of approximately 5 fT/Hz{sup 1/2} is achieved with gradiometer arrangement.

  11. Optimizations of spin-exchange relaxation-free magnetometer based on potassium and rubidium hybrid optical pumping.

    PubMed

    Fang, Jiancheng; Wang, Tao; Zhang, Hong; Li, Yang; Zou, Sheng

    2014-12-01

    The hybrid optical pumping atomic magnetometers have not realized its theoretical sensitivity, the optimization is critical for optimal performance. The optimizations proposed in this paper are suitable for hybrid optical pumping atomic magnetometer, which contains two alkali species. To optimize the parameters, the dynamic equations of spin evolution with two alkali species were solved, whose steady-state solution is used to optimize the parameters. The demand of the power of the pump beam is large for hybrid optical pumping. Moreover, the sensitivity of the hybrid optical pumping magnetometer increases with the increase of the power density of the pump beam. The density ratio between the two alkali species is especially important for hybrid optical pumping magnetometer. A simple expression for optimizing the density ratio is proposed in this paper, which can help to determine the mole faction of the alkali atoms in fabricating the hybrid cell before the cell is sealed. The spin-exchange rate between the two alkali species is proportional to the saturated density of the alkali vapor, which is highly dependent on the temperature of the cell. Consequently, the sensitivity of the hybrid optical pumping magnetometer is dependent on the temperature of the cell. We proposed the thermal optimization of the hybrid cell for a hybrid optical pumping magnetometer, which can improve the sensitivity especially when the power of the pump beam is low. With these optimizations, a sensitivity of approximately 5 fT/Hz(1/2) is achieved with gradiometer arrangement.

  12. Monitoring of Building Heating and Cooling Systems Based on Geothermal Heat Pump in Galicia (Spain)

    NASA Astrophysics Data System (ADS)

    Iglesias, M.; Rodriguez, J.; Franco, D.

    2012-10-01

    In November 2009 was signed an agreement between Galicia's Government and EnergyLab to develop a project related with the geothermal heatpumps (hereafter, GSHP) technology. That project consisted in replacing the existing thermal equipment generators (diesel boilers and air-water heat pumps) by GSHP systems in representative public buildings: two nursery schools, a university library, a health centre and a residential building. This new systems will reach the demands of existing heating, cooling and domestic hot water (hereafter, DHW). These buildings can serve as examples of energy and economic savings that can offer this technology. We will show detailed analysis of the GSHP facilities monitored, since the starting-up of them. Which includes: COP's, EER's, energy consumption, operating costs, operation hours of the system, economic and emissions comparative, geothermal exchange evolution graphs, environmental conditions evolution graphs (temperature and demands), etc. The results presented show an example of the important benefits of the GSHP technology and the significant savings that can offer its implementation for heating, cooling and DHW production. Note to the reader: The article number has been corrected on web pages on November 22, 2013.

  13. DIFFUSION PUMP

    DOEpatents

    Levenson, L.

    1963-09-01

    A high-vacuum diffusion pump is described, featuring a novel housing geometry for enhancing pumping speed. An upright, cylindrical lower housing portion is surmounted by a concentric, upright, cylindrical upper housing portion of substantially larger diameter; an uppermost nozzle, disposed concentrically within the upper portion, is adapted to eject downwardly a conical sheet of liquid outwardly to impinge upon the uppermost extremity of the interior wall of the lower portion. Preferably this nozzle is mounted upon a pedestal rising coaxially from within the lower portion and projecting up into said upper portion. (AEC)

  14. Electrokinetic pump

    DOEpatents

    Hencken, Kenneth R.; Sartor, George B.

    2004-08-03

    An electrokinetic pump in which the porous dielectric medium of conventional electrokinetic pumps is replaced by a patterned microstructure. The patterned microstructure is fabricated by lithographic patterning and etching of a substrate and is formed by features arranged so as to create an array of microchannels. The microchannels have dimensions on the order of the pore spacing in a conventional porous dielectric medium. Embedded unitary electrodes are vapor deposited on either end of the channel structure to provide the electric field necessary for electroosmotic flow.

  15. Design and simulation of an electrically pumped Schottky-junction-based plasmonic amplifier.

    PubMed

    Livani, Abdolber Mallah; Kaatuzian, Hassan

    2015-03-20

    We have investigated an amplifier which operates on surface plasmon polaritons (SPPs). A semiconductor is considered instead of dielectric since its interface with metal can support transverse-magnetic-polarized SPP propagation. A T-shaped cross section for the analyzed waveguide is considered. Metal-semiconductor interface conditions in particular can be regarded as a Schottky junction that has the capability of being pumped electrically. So compensation of propagation loss imposed by metal is possible and beyond that, amplification occurs. This configuration has advantages such as a simple fabrication process and compact size. This scheme has been implemented previously in 3.16, 1.7, and 0.8 μm for increasing the propagation length of the SPP but here, the free-space wavelength of 1.55 μm is considered for designing a plasmonic amplifier. This wavelength is selected because this is the most used wavelength in fiber-optic telecommunications due to its ultralow attenuation in silica. However, designing such an amplifier with too many effects that arise in a Schottky junction may be an extremely difficult process. So simplification, which regards essential effects and ignores nonimportant ones, is included. In this work, gold is considered as the metal and n+-doped In0.53Ga0.47As as the semiconductor to form a Schottky junction. The semiconductor has a doping concentration of 1×1018  cm-3. In forward bias of 1.25 V, the gain coefficient of the SPP mode is estimated up to 337  cm-1 which corresponds to 14.62 dB power gain for a 100 μm long amplifier. PMID:25968496

  16. Variable pump flow-based Doppler ultrasound method: a novel approach to the measurement of access flow in hemodialysis patients.

    PubMed

    Lin, Chih-Ching; Chang, Chao-Fu; Chiou, Hong-Jen; Sun, Ying-Chou; Chiang, Shou-Shan; Lin, Ming-Wei; Lee, Pui-Ching; Yang, Wu-Chang

    2005-01-01

    Decreasing vascular access flow (Qa) is an important predictor of future access thrombosis and malfunction for hemodialysis (HD) patients. Among all of the methods for determining Qa, the variable pump flow (VPF) Doppler method measures Qa according to the change in Doppler signal between the arterial and the venous needles under different pump flow. After this technique was combined with spectral analysis of Duplex Doppler imaging, the variable pump flow-based Doppler ultrasound method (VPFDUM) for Qa measurement was developed. This study compared the reproducibility and correlation of Qa measurements for three different methods-VPFDUM, ultrasound dilution method (UDM), and conventional Doppler ultrasound method (CDUM)-in 55 HD patients. The mean value of Qa by VPFDUM (870.8 +/- 412.0 ml/min) was close to that by UDM (868.6 +/- 417.9 ml/min) but higher than that by CDUM (either of the above values versus 685.1 +/- 303.6 ml/min; P < 0.005). The mean values of coefficient of variation were similar by VPFDUM (1.6%) and UDM (1.4%) but lower than that by CDUM (either of the above values versus 6.8%; P < 0.01). The correlation coefficient and intraclass correlation coefficient of the repeated Qa measurements by VPFDUM (0.985 and 0.993; P < 0.001) were also similar to those by UDM (0.992 and 0.995; P < 0.001) but slightly higher than those by CDUM (0.917 and 0.948; P < 0.005). Either the reproducibility of VPFDUM (r=0.98, P < 0.0001) or the correlation between VPFDUM and UDM (r=0.99, P < 0.0001) in Qa measurements is good. The unassisted patency of vascular access at 6 mo was significantly poorer in patients with Qa <500 ml/min than those with Qa >500 ml/min (13.6% versus 92.2%; P < 0.0001). In conclusion, VPFDUM is a noninvasive, accurate, and reliable procedure for Qa measurement and prediction of the prognosis of vascular access in HD patients.

  17. A temperature-based variable for monitoring outdoor coil airflow in an air-source heat pump during frost-forming conditions

    SciTech Connect

    Payne, W.V. II; O`Neal, D.L.

    1994-12-31

    Frost-buildup tests were conducted on a 3-ton (10.6kW) nominal cooling capacity air-source heat pump with an orifice expansion device. This study was conducted to determine if a simple temperature-based control variable could be used to determine the amount of degradation in the outdoor airflow (and heating capacity) of the unit. Refrigerant pressures and temperatures were monitored through-out the system in addition to power requirements and airflow rates. A temperature-based variable was developed that could be used to predict airflow degradation across the outdoor heat exchanger. This variable was defined using the difference between ambient air temperature and a measured refrigerant temperature. Eight refrigerant temperatures in the system were recorded and evaluated. Plots of airflow as a function of this temperature variable, along with plots of the absolute value percent changes of this temperature variable and airflow, were evaluated to determine which refrigerant temperatures could best be used in the variable to predict degradation in airflow. The best fit between the temperature-based variable and airflow degradation occurred with the inclusion of the refrigerant temperature at the outlet from the evaporator. Calculations of percent changes based on values sampled after a defrost showed a polynomial or linear relationship between airflow and the temperature-based variable. Data from two previously tested heat pumps were also used to compare changes in the outdoor airflow to changes in the temperature-based variable. The base-case heat pump and another heat pump both used an orifice as the expansion device in the heating mode. A third heat pump, which used a thermostatic expansion valve (TXV) as the expansion device in the heating mode, failed to show the same goodness of fit between airflow and the temperature-based variable.

  18. Ultra-broadband Superradiant Pulses from Femtosecond Laser Pumped InP based Quantum Well Laser Diode

    NASA Astrophysics Data System (ADS)

    Liu, Jingjing

    Laser techniques, such as gain / Q switching, mode-locking, have successfully overcome the energy restriction of gain clamping in the stead-state operated lasers, and allowed the generation of giant pulses with short pulse durations. However, gain saturation further limits the amount of stored energy in a gain medium, and therefore limits the possible maximum pulse energy obtained by laser techniques. Here we circumvent both gain clamping and the capacity limitation of energy storage by operating the double-quantum-well laser diode chips on ultrafast gain-switching model using femtosecond (fs) laser pulses as the optical pump. The advantage of our pumping approach is that the fs pulse can instantly produce a very large number of carriers, and therefore enable the formation of non-equilibrium coherent e-h BCS-like condensate state in a large energy region from the lowest QW subband edges to the highest subband and then obtain the ultra-broadband superradiant pulses. Superradiance (SR) or the coherent spontaneous emission is not a new quantum optics phenomenon, which has been proposed in 1954 by R. Dicke, even earlier than the invention of laser. It is famous as by its ultrashort duration, high peak power, high coherence and high timing jitter. Recently, femtosecond SR pulses have been generated from semiconductors. This investigation has revived both theoretical and experimental studies of SR emission. In this thesis, we have demonstrated the generation of intense, delayed SR pulses from the InP based double quantum well laser diode at room temperature. The 1040 nm femtosecond laser was applied as the optical pumping source, and when the pump power is high enough, the cooperative recombination of e-h pairs from higher order quantum energy levels can occur to generate SR bursts earlier than the cooperative emission from the lower quantum energy levels. Then, ultra-broadband TM polarized SR pulses have been firstly generated at room temperature. Our experiments also

  19. Long life coolant pump technology

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Design concepts were investigated to improve space system coolant pump technology to be suitable for mission durations of two years and greater. These design concepts included an improved bearing system for the pump rotating elements, consisting of pressurized conical bearings. This design was satisfactorily endurance tested as was a new prototype pump built using various other improved design concepts. Based upon an overall assessment of the results of the program it is concluded that reliable coolant pumps can be designed for three year space missions.

  20. A low sample volume particle separation device with electrokinetic pumping based on circular travelling-wave electroosmosis.

    PubMed

    Lin, Shiang-Chi; Lu, Jau-Ching; Sung, Yu-Lung; Lin, Chih-Ting; Tung, Yi-Chung

    2013-08-01

    Particle separation is a crucial step in sample preparation processes. The preparation of low volume samples is especially important for clinical diagnosis and chemical analysis. The advantages of microfluidic techniques have lead them to become potential candidates for particle separation. However, existing microfluidic devices require external pumping sources and extensive geometric patterns to attain high separation efficiency, which is disadvantageous when handling low volume samples. This paper presents a low sample volume particle separation microfluidic device with low voltage electrokinetic pumping based on circular travelling-wave electroosmosis (TWEO). Computational numerical software was utilized to simulate two electrokinetic mechanisms: circular TWEO and dielectrophoresis (DEP). The circular TWEO shear flow generates a velocity gradient in the radial direction which causes a shear stress-induced force to drag particles into the center region of the device. In contrast, the non-parallel electrodes induce negative DEP forces which push polystyrene beads towards the peripheral regions; the magnitude of the DEP forces are dependent on the sizes of the polystyrene beads. We used particles of various sizes to experimentally prove the concept of particle separation. Our experiments show that 15 μm beads are dragged into the center region due to the shear stress-induced force, and 1 μm beads move towards the outer region because of the large negative DEP force. The results show a separation purity of 94.4% and 80.0% for 15 μm and 1 μm beads respectively. We further demonstrated particle isolation from a sample of containing a small proportion of 6 μm beads mixed with 1 μm beads at a concentration ratio of 1 : 300. Therefore, the innovative device developed in this paper provides a promising solution to allow particle separation in sample volumes as low as 50 nL. PMID:23753015

  1. 123. UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751). PUMP ...

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

    123. UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751). PUMP ON LEFT; HYDRAULIC CONTROL PANEL FOR UMBILICAL MAST AND TRENCH DOORS IN CENTER OF ROOM, FACING WEST. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  2. Direct comparison of shot-to-shot noise performance of all normal dispersion and anomalous dispersion supercontinuum pumped with sub-picosecond pulse fiber-based laser

    PubMed Central

    Klimczak, Mariusz; Soboń, Grzegorz; Kasztelanic, Rafał; Abramski, Krzysztof M.; Buczyński, Ryszard

    2016-01-01

    Coherence of supercontinuum sources is critical for applications involving characterization of ultrafast or rarely occurring phenomena. With the demonstrated spectral coverage of supercontinuum extending from near-infrared to over 10 μm in a single nonlinear fiber, there has been a clear push for the bandwidth rather than for attempting to optimize the dynamic properties of the generated spectrum. In this work we provide an experimental assessment of the shot-to-shot noise performance of supercontinuum generation in two types of soft glass photonic crystal fibers. Phase coherence and intensity fluctuations are compared for the cases of an anomalous dispersion-pumped fiber and an all-normal dispersion fiber. With the use of the dispersive Fourier transformation method, we demonstrate that a factor of 100 improvement in signal-to-noise ratio is achieved in the normal-dispersion over anomalous dispersion-pumped fiber for 390 fs long pump pulses. A double-clad design of the photonic lattice of the fiber is further postulated to enable a pump-related seeding mechanism of normal-dispersion supercontinuum broadening under sub-picosecond pumping, which is otherwise known for similar noise characteristics as modulation instability driven, soliton-based spectra. PMID:26759188

  3. Direct comparison of shot-to-shot noise performance of all normal dispersion and anomalous dispersion supercontinuum pumped with sub-picosecond pulse fiber-based laser.

    PubMed

    Klimczak, Mariusz; Soboń, Grzegorz; Kasztelanic, Rafał; Abramski, Krzysztof M; Buczyński, Ryszard

    2016-01-01

    Coherence of supercontinuum sources is critical for applications involving characterization of ultrafast or rarely occurring phenomena. With the demonstrated spectral coverage of supercontinuum extending from near-infrared to over 10 μm in a single nonlinear fiber, there has been a clear push for the bandwidth rather than for attempting to optimize the dynamic properties of the generated spectrum. In this work we provide an experimental assessment of the shot-to-shot noise performance of supercontinuum generation in two types of soft glass photonic crystal fibers. Phase coherence and intensity fluctuations are compared for the cases of an anomalous dispersion-pumped fiber and an all-normal dispersion fiber. With the use of the dispersive Fourier transformation method, we demonstrate that a factor of 100 improvement in signal-to-noise ratio is achieved in the normal-dispersion over anomalous dispersion-pumped fiber for 390 fs long pump pulses. A double-clad design of the photonic lattice of the fiber is further postulated to enable a pump-related seeding mechanism of normal-dispersion supercontinuum broadening under sub-picosecond pumping, which is otherwise known for similar noise characteristics as modulation instability driven, soliton-based spectra. PMID:26759188

  4. [Improved Response to 5-FU Using Dose Adjustment and Elastomeric Pump Selection Based on Monitoring of the 5-FU Level--A Case Report].

    PubMed

    Muneoka, Katsuki; Shirai, Yoshio; Kanda, Junkichi; Sasaki, Masataka; Wakai, Toshifumi; Wakabayashi, Hiroyuki

    2015-10-01

    A 6 1-year-old man with unresectable multiple hepatic metastases after resection of sigmoid colon carcinoma was treated with irinotecan and infused 5-fluorouracil (5-FU) plus Leucovorin (FOLFIRI). Since the levels of tumor markers increased, the 5-FU dose was increased from 2,700 to 3,000 mg/m2 using a Jackson-type pump and an extended infusion time of 53 hours. The blood level of 5-FU was 507 ng/mL 16 hours after starting the infusion. The pump was then changed to a bottle-type pump with the same dose of 3,000 mg/m2. At 16 hours, the 5-FU level was 964.5 ng/mL. The areas under the concentration vs. time curve (AUC mg・h/L)were 21 and 44 mg・h/L for the Jackson- and bottle-type pumps, respectively. Owing to the development of Grade 3 stomatitis and hand-foot syndrome, 5-FU was reduced to 2,700 mg/m2 with a bottle-type pump. The AUC decreased to 27 mg・h/L, but the liver metastases were reduced and the adverse effects subsided to Grade 1. This case shows that individual dose adjustment of 5-FU to the appropriate AUC based on pharmacokinetic monitoring of the blood 5-FU level can improve the response, reduce adverse effects, and have a clinical benefit. PMID:26489552

  5. Low-noise and high-gain Brillouin optical amplifier for narrowband active optical filtering based on a pump-to-signal optoelectronic tracking.

    PubMed

    Souidi, Yahia; Taleb, Fethallah; Zheng, Junbo; Lee, Min Won; Du Burck, Frédéric; Roncin, Vincent

    2016-01-10

    We implement and characterize an optical narrowband amplifier based on stimulated Brillouin scattering with pump-to-signal relative frequency fluctuations overcome thanks to an active pump tracking. We achieve a precise characterization of this amplifier in terms of gain and noise degradation (noise figure). The performances of this stable selective amplification are compared to those of a conventional erbium-doped fiber amplifier in order to highlight the interest of the Brillouin amplification solution for active narrow optical filtering with a bandpass of 10 MHz. Thanks to the simple optoelectronic pump-to-signal tracking, the Brillouin active filter appears as a stable and reliable solution for narrowband optical processing in the coherent optical communication context and optical sensor applications. PMID:26835759

  6. Quasilinear theory of terahertz free-electron lasers based on Compton scattering of incoherent pump wave by intense relativistic electron beam

    NASA Astrophysics Data System (ADS)

    Ginzburg, N. S.; Kocharovskaya, E. R.

    2016-08-01

    The use of incoherent broadband pump radiation for improving the electron efficiency in the free-electron lasers (FEL) based on stimulated backscattering is considered. On the basis of a quasilinear approach, it is shown that the efficiency increases in proportion to the width of the pump spectrum. The effect is owing to a broadening of the spectrum of synchronous combination waves and realization of a mechanism of stochastic particle deceleration. The injection of a monochromatic seed signal in a single pass FEL amplifier or the implementation of a selective high-Q resonator in an FEL oscillator makes the high-frequency scattered radiation be monochromatic in spite of an incoherent pumping. In the regime of stochastic particle deceleration, the efficiency only slightly depends on the spread of the beam parameters, which is beneficial for a terahertz FEL powered by intense relativistic electron beams.

  7. 18. Electrically driven pumps in Armory Street Pump House. Pumps ...

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

    18. Electrically driven pumps in Armory Street Pump House. Pumps in background formerly drew water from the clear well. They went out of service when use of the beds was discontinued. Pumps in the foreground provide high pressure water to Hamden. - Lake Whitney Water Filtration Plant, Armory Street Pumphouse, North side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  8. Gallic acid-based indanone derivative interacts synergistically with tetracycline by inhibiting efflux pump in multidrug resistant E. coli.

    PubMed

    Dwivedi, Gaurav Raj; Tiwari, Nimisha; Singh, Aastha; Kumar, Akhil; Roy, Sudeep; Negi, Arvind Singh; Pal, Anirban; Chanda, Debabrata; Sharma, Ashok; Darokar, Mahendra P

    2016-03-01

    The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition.

  9. Reactor coolant pump flywheel

    SciTech Connect

    Finegan, John Raymond; Kreke, Francis Joseph; Casamassa, John Joseph

    2013-11-26

    A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.

  10. Bioinspired artificial single ion pump.

    PubMed

    Zhang, Huacheng; Hou, Xu; Zeng, Lu; Yang, Fu; Li, Lin; Yan, Dadong; Tian, Ye; Jiang, Lei

    2013-10-30

    Bioinspired artificial functional nanochannels for intelligent molecular and ionic transport control at the nanoscale have wide potential applications in nanofluidics, energy conversion, and biosensors. Although various smart passive ion transport properties of ion channels have been artificially realized, it is still hugely challenging to achieve high level intelligent ion transport features in biological ion pumps. Here we show a unique bioinspired single ion pump based on a cooperative pH response double-gate nanochannel, whose gates could be opened and closed alternately/simultaneously under symmetric/asymmetric pH environments. With the stimulation of the double-gate nanochannel by continuous switching of the symmetric/asymmetric pH stimuli, the bioinspired system systematically realized three key ionic transport features of biological ion pumps, including an alternating gates ion pumping process under symmetric pH stimuli, transformation of the ion pump into an ion channel under asymmetric pH stimuli, and a fail-safe ion pumping feature under both symmetric and asymmetric pH stimuli. The ion pumping processes could well be reproduced under a concentration gradient. With the advantages of the extraordinary ionic transport functions of biological ion pumps, the bioinspired ion pump should find widespread applicability in active transportation-controlling smart nanofluidic devices, efficient energy conversions, and seawater desalinization, and open the way to design and develop novel bioinspired intelligent artificial nanochannel materials.

  11. Bioinspired artificial single ion pump.

    PubMed

    Zhang, Huacheng; Hou, Xu; Zeng, Lu; Yang, Fu; Li, Lin; Yan, Dadong; Tian, Ye; Jiang, Lei

    2013-10-30

    Bioinspired artificial functional nanochannels for intelligent molecular and ionic transport control at the nanoscale have wide potential applications in nanofluidics, energy conversion, and biosensors. Although various smart passive ion transport properties of ion channels have been artificially realized, it is still hugely challenging to achieve high level intelligent ion transport features in biological ion pumps. Here we show a unique bioinspired single ion pump based on a cooperative pH response double-gate nanochannel, whose gates could be opened and closed alternately/simultaneously under symmetric/asymmetric pH environments. With the stimulation of the double-gate nanochannel by continuous switching of the symmetric/asymmetric pH stimuli, the bioinspired system systematically realized three key ionic transport features of biological ion pumps, including an alternating gates ion pumping process under symmetric pH stimuli, transformation of the ion pump into an ion channel under asymmetric pH stimuli, and a fail-safe ion pumping feature under both symmetric and asymmetric pH stimuli. The ion pumping processes could well be reproduced under a concentration gradient. With the advantages of the extraordinary ionic transport functions of biological ion pumps, the bioinspired ion pump should find widespread applicability in active transportation-controlling smart nanofluidic devices, efficient energy conversions, and seawater desalinization, and open the way to design and develop novel bioinspired intelligent artificial nanochannel materials. PMID:23773031

  12. Size-based cell sorting with a resistive pulse sensor and an electromagnetic pump in a microfluidic chip.

    PubMed

    Song, Yongxin; Li, Mengqi; Pan, Xinxiang; Wang, Qi; Li, Dongqing

    2015-02-01

    An electrokinetic microfluidic chip is developed to detect and sort target cells by size from human blood samples. Target-cell detection is achieved by a differential resistive pulse sensor (RPS) based on the size difference between the target cell and other cells. Once a target cell is detected, the detected RPS signal will automatically actuate an electromagnetic pump built in a microchannel to push the target cell into a collecting channel. This method was applied to automatically detect and sort A549 cells and T-lymphocytes from a peripheral fingertip blood sample. The viability of A549 cells sorted in the collecting well was verified by Hoechst33342 and propidium iodide staining. The results show that as many as 100 target cells per minute can be sorted out from the sample solution and thus is particularly suitable for sorting very rare target cells, such as circulating tumor cells. The actuation of the electromagnetic valve has no influence on RPS cell detection and the consequent cell-sorting process. The viability of the collected A549 cell is not impacted by the applied electric field when the cell passes the RPS detection area. The device described in this article is simple, automatic, and label-free and has wide applications in size-based rare target cell sorting for medical diagnostics.

  13. Recursive approach of EEG-segment-based principal component analysis substantially reduces cryogenic pump artifacts in simultaneous EEG-fMRI data.

    PubMed

    Kim, Hyun-Chul; Yoo, Seung-Schik; Lee, Jong-Hwan

    2015-01-01

    Electroencephalography (EEG) data simultaneously acquired with functional magnetic resonance imaging (fMRI) data are preprocessed to remove gradient artifacts (GAs) and ballistocardiographic artifacts (BCAs). Nonetheless, these data, especially in the gamma frequency range, can be contaminated by residual artifacts produced by mechanical vibrations in the MRI system, in particular the cryogenic pump that compresses and transports the helium that chills the magnet (the helium-pump). However, few options are available for the removal of helium-pump artifacts. In this study, we propose a recursive approach of EEG-segment-based principal component analysis (rsPCA) that enables the removal of these helium-pump artifacts. Using the rsPCA method, feature vectors representing helium-pump artifacts were successfully extracted as eigenvectors, and the reconstructed signals of the feature vectors were subsequently removed. A test using simultaneous EEG-fMRI data acquired from left-hand (LH) and right-hand (RH) clenching tasks performed by volunteers found that the proposed rsPCA method substantially reduced helium-pump artifacts in the EEG data and significantly enhanced task-related gamma band activity levels (p=0.0038 and 0.0363 for LH and RH tasks, respectively) in EEG data that have had GAs and BCAs removed. The spatial patterns of the fMRI data were estimated using a hemodynamic response function (HRF) modeled from the estimated gamma band activity in a general linear model (GLM) framework. Active voxel clusters were identified in the post-/pre-central gyri of motor area, only from the rsPCA method (uncorrected p<0.001 for both LH/RH tasks). In addition, the superior temporal pole areas were consistently observed (uncorrected p<0.001 for the LH task and uncorrected p<0.05 for the RH task) in the spatial patterns of the HRF model for gamma band activity when the task paradigm and movement were also included in the GLM.

  14. CHARACTERIZATION OF AEROSOLS FROM A WATER-BASED CLEANER APPLIED WITH A HAND-PUMP SPRAYER

    EPA Science Inventory

    The paper gives results of tests that were performed in a controlled-environment test room to measure particle concentrations and size distributions and concentrations of selected volatily organic compounds during, and following, application of water-based cleaners to realistic s...

  15. Efficient, green laser based on a blue-diode pumped rare-earth-doped fluoride crystal in an extremely short resonator

    NASA Astrophysics Data System (ADS)

    Strotkamp, Michael; Schwarz, Thomas; Jungbluth, Bernd; Faidel, Heinrich; Leers, Michael

    2010-02-01

    The green cw laser presented in this work is realized by means of a Pr:YLF crystal emitting at 523 nm that is pumped by a blue GaN laser diode in an extremely short resonator. With a 500 mW-diode a laser has been achieved with M2 = 1, a slope of 40 % and an output power of 140mW with an absorbed pump power of 410 mW which results in an electrooptical efficiency of 6.5 %. Despite the reduced overlap with a 1 W-diode the output power rises to 290 mW with an absorbed pump power of 850 mW and the M2 increases only slightly. Based on these results a compact laser package has been accomplished using a monolithic micro optics for the beam shaping of the diode light and joining all components with a low-shrinkage adhesive on a common base plate. In a first test of the alignment strategy a laser with an output power of 92 mW has been achieved by means of the 500 mW pump power.

  16. Highly efficient cladding-pumped fibre laser based on an ytterbium-doped optical fibre and a fibre Bragg grating

    SciTech Connect

    Kurkov, Andrei S; Karpov, V I; Medvedkov, O I; Dianov, Evgenii M; Vasil'ev, Sergei A; Paramonov, Vladimir M; Protopopov, V N; Laptev, A Yu; Gur'yanov, A N; Umnikov, A A; Vechkanov, N I; Artyushenko, V G; Frahm, J

    1999-06-30

    Ytterbium-ion-doped double-clad optical fibres were developed. The differential quantum efficiency of a diode-pumped fibre laser, fabricated on the basis of such optical fibres with a fibre Bragg grating, was 90%. (lasers)

  17. Pump-free gradient-based micro-device enables quantitative and high-throughput bacterial growth inhibition analysis.

    PubMed

    Ran, Min; Wang, Ying; Wang, Sida; Luo, Chunxiong

    2015-08-01

    Antibiotic susceptibility testing is very important in antibiotic therapy. Traditional methods to determine antibiotic susceptibility include disk diffusion and broth dilution. However, these tests are always labor intensive, time-consuming, and need large amounts of reagents. In this paper, we demonstrated a novel pump-free micro-device that enables quantitative and high-throughput bacterial growth inhibition analysis. This device consists of a series of wells and diffusion-based antibiotic gradient channels. The wells serve as antibiotic sources and buffer sinks, and we could easily observe the bacterial growth in the gradient channels .The design of the multi-wells is adapted to the commercialized multi-channel pipette, which makes it very convenient for loading reagents into the wells. For each assay, only about 20 μL antibiotic solution is needed. As a demonstration, we used both fluorescence images and dark-field images to quantify the bacterial growth inhibition effect under different antibiotics. The quantitative data of bacterial growth inhibition under different antibiotics can be obtained within 3 to 4 h. Considering the simple operation process and the high-throughput and quantitative result this device can offer, it has great potential to be widely used in clinics and may be useful for the study of the kinetics of bacterial growth.

  18. X-ray studies and time-resolved photoluminescence on optically pumped antimonide-based midinfrared type-II lasers.

    PubMed

    Schwender, Carsten; Drumm, Jan Oliver; Hoffmann, Goetz; Vogelgesang, Birgit; Fouckhardt, Henning

    2004-12-01

    We report on high-resolution X-ray diffraction and time-resolved photoluminescence (TR-PL) studies of antimonide-based midinfrared (MIR) type-II laser samples. A structural characterization taking into account asymmetrical strain, layer tilting, and relaxation enables an accurate determination of the average lattice constant of the active region and the composition of the cladding layers. By designing the antimonide-to-arsenide interfaces, we achieve exact lattice matching of the active region to the substrate. Non-radiative recombination processes are investigated with time-resolved photoluminescence. The samples are also characterized under optically pumped laser operation. By an examination of the time-integrated and time-resolved amplified spontaneous emission (TR-ASE), we investigate the modal gain and gain dynamics. The variable stripe length method is combined with the TR-PL approach. Compared to the time-integrated gain spectra the spectral dependence of the maximum and minimum time-resolved gain shows a broad plateau. The full width half maximum (FWHM) of the TR-ASE pulse is 5.5 +/- 0.5 ps. Thus, short pulses in this range should be achievable upon laser operation. The active regions of the laser structures investigated here are promising subunits of type-II quantum cascade lasers.

  19. Ultrasound based mitral valve annulus tracking for off-pump beating heart mitral valve repair

    NASA Astrophysics Data System (ADS)

    Li, Feng P.; Rajchl, Martin; Moore, John; Peters, Terry M.

    2014-03-01

    Mitral regurgitation (MR) occurs when the mitral valve cannot close properly during systole. The NeoChordtool aims to repair MR by implanting artificial chordae tendineae on flail leaflets inside the beating heart, without a cardiopulmonary bypass. Image guidance is crucial for such a procedure due to the lack of direct vision of the targets or instruments. While this procedure is currently guided solely by transesophageal echocardiography (TEE), our previous work has demonstrated that guidance safety and efficiency can be significantly improved by employing augmented virtuality to provide virtual presentation of mitral valve annulus (MVA) and tools integrated with real time ultrasound image data. However, real-time mitral annulus tracking remains a challenge. In this paper, we describe an image-based approach to rapidly track MVA points on 2D/biplane TEE images. This approach is composed of two components: an image-based phasing component identifying images at optimal cardiac phases for tracking, and a registration component updating the coordinates of MVA points. Preliminary validation has been performed on porcine data with an average difference between manually and automatically identified MVA points of 2.5mm. Using a parallelized implementation, this approach is able to track the mitral valve at up to 10 images per second.

  20. Diode-pumped two-frequency lasers based on c-cut vanadate crystals

    SciTech Connect

    Sirotkin, A A; Garnov, Sergei V; Zagumennyi, A I; Zavartsev, Yu D; Kutovoi, S A; Vlasov, V I; Shcherbakov, Ivan A

    2009-09-30

    The luminescent and lasing properties of the neo-dymium ion at the {sup 4}F{sub 3/2}-{sup 4}I{sub 11/2} transition in c-cut vanadate crystals (Nd:YVO{sub 4}, Nd:GdVO{sub 4}, and Nd:Gd{sub 1-x}Y{sub x}VO{sub 4}) are studied. Tuning of the laser radiation wavelength ({Delta}{lambda} = 5.4 nm) is demonstrated. Two-frequency laser schemes with the use of a Lyot filter, a Fabry-Perot etalon, and a Brewster prism as spectral selection elements are proposed and experimentally realised. Stable two-frequency lasing of a laser based on the c-cut Nd:GdVO{sub 4} crystal was obtained in the cw, Q-switched (nanosecond pulses), and active acousto-optic mode-locked (picosecond pulses) regimes. (lasers)

  1. The first field-based descriptions of pumping-induced saltwater intrusion and upconing

    NASA Astrophysics Data System (ADS)

    Houben, Georg; Post, Vincent E. A.

    2016-09-01

    Development of the ideas about the equilibrium between freshwater and saline water has received considerable attention in the literature, but little has been written so far about the earliest scientific works about well salinization. Based on a review of the literature from the second half of the 19th century and the early 20th century, this historical note explores how insights into groundwater abstraction and saltwater intrusion developed, and examples of the earliest field studies are provided. Fundamental research was driven by the need for increasing water supply, but the progress of science did not lead to sustainable management practices everywhere. Research outcomes were shared between scientists of different countries, marking the beginning of coastal hydrogeology as a scientific specialization in the first decade of the 20th century.

  2. Well pump

    DOEpatents

    Ames, Kenneth R.; Doesburg, James M.

    1987-01-01

    A well pump includes a piston and an inlet and/or outlet valve assembly of special structure. Each is formed of a body of organic polymer, preferably PTFE. Each includes a cavity in its upper portion and at least one passage leading from the cavity to the bottom of the block. A screen covers each cavity and a valve disk covers each screen. Flexible sealing flanges extend upwardly and downwardly from the periphery of the piston block. The outlet valve block has a sliding block and sealing fit with the piston rod.

  3. Well pump

    SciTech Connect

    Page, J.S.

    1983-03-08

    Well fluid pumping apparatus comprises: (A) body structure defining an upright plunger bore, (B) a plunger reciprocable in that bore, (C) the body structure also defining a chamber sidewardly offset from an axis defined by the plunger bore and communicating with the bore, and (D) valving carried by the body structure to pass intake fluid via the chamber into the plunger bore in response to stroking of the plunger in one direction in the bore, and to pass discharge fluid from the plunger bore into and from the chamber in response to stroking of the plunger in the opposite direction in the bore.

  4. High-power multichannel PPMgLN-based optical parametric oscillator pumped by a master oscillation power amplification-structured Q-switched fiber laser.

    PubMed

    Chen, Tao; Wei, Kaihua; Jiang, Peipei; Wu, Bo; Shen, Yonghang

    2012-10-01

    We experimentally demonstrated a compact fiber laser-pumped multichannel PPMgLN-based optical parametric oscillator (OPO) generating total OPO output power of 15.8, 15.2, 14.2, 12.9, and 8.8 W with idler output power of 4.7, 4.3, 4.1, 3.3, and 2.1 W at the wavelength of 3.43, 3.63, 3.72, 3.83, and 3.99 μm, respectively. The OPO was pumped by a fully fiberized polarization maintaining (PM) ytterbium-doped pulsed fiber master oscillation power amplifier (MOPA) operating at 1064 nm at a repetition rate of 65 kHz with effective pump power of 28.7 W. The MOPA system was constructed with an acousto-optic Q-switched fiber laser seed and only one stage PM fiber amplifier without any free space components, which makes the pump system compact and stable in the long-term. Comparisons on efficiencies and signal wavelength shifts between different channels showed that the idler absorption was the main factor preventing high average-power OPO operation with long idler wavelength. PMID:23033106

  5. Dimerization, trimerization and quantum pumping

    NASA Astrophysics Data System (ADS)

    Guo, Huaiming

    2014-03-01

    We study one-dimensional topological models with dimerization and trimerization and show that these models can be generated using interaction or optical superlattice. The topological properties of these models are demonstrated by the appearance of edge states and the mechanism of dimerization and trimerization is analyzed. Then we show that a quantum pumping process can be constructed based on each one-dimensional topological model. The quantum pumping process is explicitly demonstrated by the instantaneous energy spectrum and local current. The result shows that the pumping is assisted by the gapless states connecting the bands and one charge is pumped during a cycle, which also defines a nonzero Chern number. Our study systematically shows the connection of one-dimensional topological models and quantum pumping, and is useful for the experimental studies on topological phases in optical lattices and photonic quasicrystals.

  6. Expression profile analysis based on DNA microarray for patients undergoing off-pump coronary artery bypass surgery

    PubMed Central

    SUN, YUNPENG; GAO, YONGSHENG; SUN, JINGNAN; LIU, XUGUANG; MA, DASHI; MA, CHUNYE; WANG, YONG

    2016-01-01

    Off-pump coronary artery bypass (OPCAB) surgery is the most effective treatment for coronary heart disease. The aim of this study was to explore the effects of OPCAB on the basis of the associated molecular mechanisms. GSE12486 expression profiles downloaded from the Gene Expression Omnibus database (GEO) were analyzed to identify the differentially expressed genes (DEGs). Principal component analysis (PCA) was conducted based on the expression profiles of DEGs. Function and pathway enrichment of upregulated DEGs was performed, followed by protein-protein interaction (PPI) network construction. Gene Set Enrichment Analysis (GSEA) was used for miRNA enrichment analysis based on expression profiles and prediction of their association with the disease. Cytoscape was applied to construct miRNA regulatory networks of DEGs. In total 64 DEGs were identified, including 63 upregulated and 1 downregulated gene. The first principal component in the PCA analysis was able to distinguish between pre- and post-OPCAB samples. Upregulated DEGs mainly enriched 20 Gene Ontology terms, such as chemokine activity, and 5 pathways including the chemokine signaling pathway. The constructed PPI network contained 234 edges and 55 nodes, and 10 upregulated hub nodes, including FBJ murine osteosarcoma viral oncogene homolog (FOS), were screened. A total of 36 miRNAs, including MIR-224 and MIR-7, were screened by GSEA enrichment analysis. A miRNA regulatory network including 176 edges and 97 nodes was constructed, showing the regulatory relationships between miRNAs and DEGs. For example, early growth response 2 (EGR2) was regulated by 8 miRNAs including MIR-150, MIR-142-3P, MIR-367 and MIR-224. The identified DEGs might play important roles in patients pre- and post-OPCAB surgery via the regulation of associated genes. PMID:26998004

  7. Human Aorta Is a Passive Pump

    NASA Astrophysics Data System (ADS)

    Pahlevan, Niema; Gharib, Morteza

    2012-11-01

    Impedance pump is a simple valveless pumping mechanism that operates based on the principles of wave propagation and reflection. It has been shown in a zebrafish that a similar mechanism is responsible for the pumping action in the embryonic heart during early stages before valve formation. Recent studies suggest that the cardiovascular system is designed to take advantage of wave propagation and reflection phenomena in the arterial network. Our aim in this study was to examine if the human aorta is a passive pump working like an impedance pump. A hydraulic model with different compliant models of artificial aorta was used for series of in-vitro experiments. The hydraulic model includes a piston pump that generates the waves. Our result indicates that wave propagation and reflection can create pumping mechanism in a compliant aorta. Similar to an impedance pump, the net flow and the flow direction depends on the frequency of the waves, compliance of the aorta, and the piston stroke.

  8. Pump apparatus

    SciTech Connect

    Kime, J.A.

    1987-02-17

    This patent describes a gas-oil well production system for pumping formation fluid wherein a down hole pump is provided having a barrel including a barrel fluid inlet, a barrel fluid outlet, a barrel chamber, and a plunger mounted in the barrel chamber having a plunger chamber. The plunger is reciprocally driven between an upper terminal position at the end of the plunger upstroke and a lower terminal position at the end of the plunger downstroke. The method for removing developed gaseous fluids in the formation fluid from the barrel chamber comprises: drawing formation fluid into the barrel chamber during the plunger upstroke; providing gas port means in the barrel; expelling the developed gaseous fluids from the barrel chamber through the gas port means during the occurrence of that portion of the plunger downstroke from the upper terminal position of the gas port means; and substantially blocking the gas port means and moving formation fluid into the plunger chamber during the occurrence of that portion of the plunger downstroke from below the gas port means to the lower terminal position.

  9. [Research on magnetic coupling centrifugal blood pump control based on a self-tuning fuzzy PI algorithm].

    PubMed

    Yang, Lei; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Wang, Wei; Zhang, Haibo; Han, Lu; Xu, Liang

    2014-10-01

    The purpose of this paper is to report the research and design of control system of magnetic coupling centrifugal blood pump in our laboratory, and to briefly describe the structure of the magnetic coupling centrifugal blood pump and principles of the body circulation model. The performance of blood pump is not only related to materials and structure, but also depends on the control algorithm. We studied the algorithm about motor current double-loop control for brushless DC motor. In order to make the algorithm adjust parameter change in different situations, we used the self-tuning fuzzy PI control algorithm and gave the details about how to design fuzzy rules. We mainly used Matlab Simulink to simulate the motor control system to test the performance of algorithm, and briefly introduced how to implement these algorithms in hardware system. Finally, by building the platform and conducting experiments, we proved that self-tuning fuzzy PI control algorithm could greatly improve both dynamic and static performance of blood pump and make the motor speed and the blood pump flow stable and adjustable. PMID:25764720

  10. [Research on magnetic coupling centrifugal blood pump control based on a self-tuning fuzzy PI algorithm].

    PubMed

    Yang, Lei; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Wang, Wei; Zhang, Haibo; Han, Lu; Xu, Liang

    2014-10-01

    The purpose of this paper is to report the research and design of control system of magnetic coupling centrifugal blood pump in our laboratory, and to briefly describe the structure of the magnetic coupling centrifugal blood pump and principles of the body circulation model. The performance of blood pump is not only related to materials and structure, but also depends on the control algorithm. We studied the algorithm about motor current double-loop control for brushless DC motor. In order to make the algorithm adjust parameter change in different situations, we used the self-tuning fuzzy PI control algorithm and gave the details about how to design fuzzy rules. We mainly used Matlab Simulink to simulate the motor control system to test the performance of algorithm, and briefly introduced how to implement these algorithms in hardware system. Finally, by building the platform and conducting experiments, we proved that self-tuning fuzzy PI control algorithm could greatly improve both dynamic and static performance of blood pump and make the motor speed and the blood pump flow stable and adjustable.

  11. Multipass pumped Nd-based thin-disk lasers: continuous-wave laser operation at 1.06 and 0.9 microm with intracavity frequency doubling.

    PubMed

    Pavel, Nicolaie; Lünstedt, Kai; Petermann, Klaus; Huber, Günter

    2007-12-01

    The laser performances of the 1.06 microm (4)F(3/2) --> (4)I(11/2) four-level transition and of the 0.9 microm (4)F(3/2) --> I(9/2)4 quasi-three-level transition were investigated using multipass pumped Nd-based media in thin-disk geometry. When pumping at 0.81 microm into the (4)F(5/2) level, continuous-wave laser operation was obtained with powers in excess of 10 W at 1.06 microm, in the multiwatt region at 0.91 microm in Nd:YVO(4) and Nd:GdVO(4), and at 0.95 microm in Nd:YAG. Intracavity frequency-doubled Nd:YVO(4) thin-disk lasers with output powers of 6.4 W at 532 nm and of 1.6 W at 457 nm were realized at this pumping wavelength. The pumping at 0.88 microm, which is directed into the (4)F(3/2) emitting level, was also employed, and Nd:YVO(4) and Nd:GdVO(4) thin-disk lasers with ~9 W output power at 1.06 microm and visible laser radiation at 0.53 microm with output power in excess of 4 W were realized. Frequency-doubled Nd:vanadate thin-disk lasers with deep blue emission at 0.46 microm were obtained under pumping directly into the (4)F(3/2) emitting level.

  12. Efflux Pump Blockers in Gram-Negative Bacteria: The New Generation of Hydantoin Based-Modulators to Improve Antibiotic Activity

    PubMed Central

    Otręebska-Machaj, Ewa; Chevalier, Jacqueline; Handzlik, Jadwiga; Szymańska, Ewa; Schabikowski, Jakub; Boyer, Gérard; Bolla, Jean-Michel; Kieć-Kononowicz, Katarzyna; Pagès, Jean-Marie; Alibert, Sandrine

    2016-01-01

    Multidrug resistant (MDR) bacteria are an increasing health problem with the shortage of new active antibiotic agents. Among effective mechanisms that contribute to the spread of MDR Gram-negative bacteria are drug efflux pumps that expel clinically important antibiotic classes out of the cell. Drug pumps are attractive targets to restore the susceptibility toward the expelled antibiotics by impairing their efflux activity. Arylhydantoin derivatives were investigated for their potentiation of activities of selected antibiotics described as efflux substrates in Enterobacter aerogenes expressing or not AcrAB pump. Several compounds increased the bacterial susceptibility toward nalidixic acid, chloramphenicol and sparfloxacin and were further pharmacomodulated to obtain a better activity against the AcrAB producing bacteria. PMID:27199950

  13. Efflux Pump Blockers in Gram-Negative Bacteria: The New Generation of Hydantoin Based-Modulators to Improve Antibiotic Activity.

    PubMed

    Otręebska-Machaj, Ewa; Chevalier, Jacqueline; Handzlik, Jadwiga; Szymańska, Ewa; Schabikowski, Jakub; Boyer, Gérard; Bolla, Jean-Michel; Kieć-Kononowicz, Katarzyna; Pagès, Jean-Marie; Alibert, Sandrine

    2016-01-01

    Multidrug resistant (MDR) bacteria are an increasing health problem with the shortage of new active antibiotic agents. Among effective mechanisms that contribute to the spread of MDR Gram-negative bacteria are drug efflux pumps that expel clinically important antibiotic classes out of the cell. Drug pumps are attractive targets to restore the susceptibility toward the expelled antibiotics by impairing their efflux activity. Arylhydantoin derivatives were investigated for their potentiation of activities of selected antibiotics described as efflux substrates in Enterobacter aerogenes expressing or not AcrAB pump. Several compounds increased the bacterial susceptibility toward nalidixic acid, chloramphenicol and sparfloxacin and were further pharmacomodulated to obtain a better activity against the AcrAB producing bacteria. PMID:27199950

  14. A tunable dual-wavelength pump source based on simulated polariton scattering for terahertz-wave generation

    NASA Astrophysics Data System (ADS)

    Sun, Bo; Liu, Jinsong; Yao, Jianquan; Li, Enbang

    2013-11-01

    We propose a dual-wavelength pump source by utilizing stimulated polariton scattering in a LiNbO3 crystal. The residual pump and the generated tunable Stokes waves can be combined to generate THz-wave generation via difference frequency generation (DFG). With a pump energy of 49 mJ, Stokes waves with a tuning range from 1067.8 to 1074 nm have been generated, and an output energy of up to 14.9 mJ at 1070 nm has been achieved with a conversion efficiency of 21.7%. A sum frequency generation experiment was carried out to demonstrate the feasibility of the proposed scheme for THz-wave DFG.

  15. Efficient, reliable, long-lifetime, diode-pumped Nd:YAG laser for space-based vegetation topographical altimetry.

    PubMed

    Coyle, Donald B; Kay, Richard B; Stysley, Paul R; Poulios, Demetrios

    2004-09-20

    A highly efficient, diode-pumped, Nd:YAG laser is described. The oscillator utilizes an unstable resonator design with a Gaussian reflectivity output coupler and a side-pumped zigzag slab gain medium. The laser produces 18-mJ, 10-ns pulses at a repetition rate of 242 Hz in a near-TEM00 mode with an optical efficiency of up to 14%. An extended performance test was recently concluded in which the transmitter operated at reduced output for more than 4.8 x 10(9) shots with no optical damage. Design criteria, beam quality, and lifetime data are presented. PMID:15473245

  16. A finite-element-based perturbation model for the rotordynamic analysis of shrouded pump impellers: Part 2: User's guide

    NASA Technical Reports Server (NTRS)

    Baskharone, Erian A.

    1993-01-01

    This report describes the computational steps involved in executing a finite-element-based perturbation model for computing the rotor dynamic coefficients of a shrouded pump impeller or a simple seal. These arise from the fluid/rotor interaction in the clearance gap. In addition to the sample cases, the computational procedure also applies to a separate category of problems referred to as the 'seal-like' category. The problem, in this case, concerns a shrouded impeller, with the exception that the secondary, or leakage, passage is totally isolated from the primary-flow passage. The difference between this and the pump problem is that the former is analytically of the simple 'seal-like' configuration, with two (inlet and exit) flow-permeable stations, while the latter constitutes a double-entry / double-discharge flow problem. In all cases, the problem is that of a rotor clearance gap. The problem here is that of a rotor excitation in the form of a cylindrical whirl around the housing centerline for a smooth annular seal. In its centered operation mode, the rotor is assumed to give rise to an axisymmetric flow field in the clearance gap. As a result, problems involving longitudinal or helical grooves, in the rotor or housing surfaces, go beyond the code capabilities. Discarding, for the moment, the pre- and post-processing phases, the bulk of the computational procedure consists of two main steps. The first is aimed at producing the axisymmetric 'zeroth-order' flow solution in the given flow domain. Detailed description of this problem, including the flow-governing equations, turbulence closure, boundary conditions, and the finite-element formulation, was covered by Baskharone and Hensel. The second main step is where the perturbation model is implemented, with the input being the centered-rotor 'zeroth-order' flow solution and a prescribed whirl frequency ratio (whirl frequency divided by the impeller speed). The computational domain, in the latter case, is treated

  17. LMFBR with booster pump in pumping loop

    DOEpatents

    Rubinstein, H.J.

    1975-10-14

    A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation.

  18. Winding for linear pump

    DOEpatents

    Kliman, Gerald B.; Brynsvold, Glen V.; Jahns, Thomas M.

    1989-01-01

    A winding and method of winding for a submersible linear pump for pumping liquid sodium is disclosed. The pump includes a stator having a central cylindrical duct preferably vertically aligned. The central vertical duct is surrounded by a system of coils in slots. These slots are interleaved with magnetic flux conducting elements, these magnetic flux conducting elements forming a continuous magnetic field conduction path along the stator. The central duct has placed therein a cylindrical magnetic conducting core, this core having a cylindrical diameter less than the diameter of the cylindrical duct. The core once placed to the duct defines a cylindrical interstitial pumping volume of the pump. This cylindrical interstitial pumping volume preferably defines an inlet at the bottom of the pump, and an outlet at the top of the pump. Pump operation occurs by static windings in the outer stator sequentially conveying toroidal fields from the pump inlet at the bottom of the pump to the pump outlet at the top of the pump. The winding apparatus and method of winding disclosed uses multiple slots per pole per phase with parallel winding legs on each phase equal to or less than the number of slots per pole per phase. The slot sequence per pole per phase is chosen to equalize the variations in flux density of the pump sodium as it passes into the pump at the pump inlet with little or no flux and acquires magnetic flux in passage through the pump to the pump outlet.

  19. Winding for linear pump

    DOEpatents

    Kliman, G.B.; Brynsvold, G.V.; Jahns, T.M.

    1989-08-22

    A winding and method of winding for a submersible linear pump for pumping liquid sodium are disclosed. The pump includes a stator having a central cylindrical duct preferably vertically aligned. The central vertical duct is surrounded by a system of coils in slots. These slots are interleaved with magnetic flux conducting elements, these magnetic flux conducting elements forming a continuous magnetic field conduction path along the stator. The central duct has placed therein a cylindrical magnetic conducting core, this core having a cylindrical diameter less than the diameter of the cylindrical duct. The core once placed to the duct defines a cylindrical interstitial pumping volume of the pump. This cylindrical interstitial pumping volume preferably defines an inlet at the bottom of the pump, and an outlet at the top of the pump. Pump operation occurs by static windings in the outer stator sequentially conveying toroidal fields from the pump inlet at the bottom of the pump to the pump outlet at the top of the pump. The winding apparatus and method of winding disclosed uses multiple slots per pole per phase with parallel winding legs on each phase equal to or less than the number of slots per pole per phase. The slot sequence per pole per phase is chosen to equalize the variations in flux density of the pump sodium as it passes into the pump at the pump inlet with little or no flux and acquires magnetic flux in passage through the pump to the pump outlet. 4 figs.

  20. Liquid metal pump

    DOEpatents

    Pennell, William E.

    1982-01-01

    The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair.

  1. Microfluidic solid phase suspension transport with an elastomer-based, single piezo-actuator, micro throttle pump.

    PubMed

    Johnston, I D; Tracey, M C; Davis, J B; Tan, C K L

    2005-03-01

    We report a Micro Throttle Pump (MTP) which has been shown to pump 5 microm diameter polystyrene beads at a concentration of 4.5 x 10(7) beads ml(-1). This new MTP design is constructed in a straightforward manner and actuated by a single piezoelectric (PZT) element. Maximum flow rates at 800 Hz drive frequency of 132 microl min(-1) with water and 108 microl min(-1) with a bead suspension were obtained. Maximum back-pressures of 6 kPa were observed in both cases. The reported MTP employs specific location of distinct internal microfluid structures cast in a single compliant elastomeric substrate to exploit the opposing directions of flexure of regions of a piezoelectric-glass composite bonded to the elastomer. By this novel means, distinct flexural regions, exhibiting compressive and tensile stresses respectively, allow both the pump's integrated input and output throttles and its pump chamber to be actuated concurrently by a single PZT. To support MTP design we also report the characterisation of an individual throttle's resistance as a function of actuator deflection and discuss the underlying mechanism of the throttling effect.

  2. Prediction of performance of centrifugal pumps during starts under pressure

    NASA Technical Reports Server (NTRS)

    Rostafinski, W.

    1969-01-01

    Method which calculates start-up characteristics of centrifugal pumps reveals a capacity to predict pressure drop characteristics of pumps with vaned diffusers. Calculations are based on pump geometry, design-point flow, speed, and pressure rise, and the pump characteristic within range of approximately ten percent of the design-point flow.

  3. An electro-osmotic micro-pump based on monolithic silica for micro-flow analyses and electro-sprays.

    PubMed

    Chen, Zilin; Wang, Ping; Chang, Hsueh-Chia

    2005-06-01

    A high-pressure electro-osmotic micro-pump fabricated by a sol-gel process is reported as a fluid-driving unit in a flow-injection analysis (FIA) system. The micro FIA system consists of a monolithic micro-pump on a glass slide (2.5 x 7.5 cm), a micro-injector, and a micro-sensor (2.5 x 1.5 cm). The monolithic silica matrix has a continuous skeleton morphology with micrometer-sized through-pores. The micrometer-size pores with a large negative surface charge density build up a large pressure under a DC electric field to drive fluid through the downstream units. A novel Nafion joint for the downstream cathode eliminates flow into the electrode reservoir and further enhances pressure build-up. The measured pump-pressure curve indicated a maximum pressure of 0.4 MPa at flow rate of 0.4 microL min(-1) at 6 kV. Despite the large voltage, the small current transmission area through the monolith produced a negligible current (less than 100 microA) that did not generate bubbles or ion contaminants. The flow rate can be precisely controlled in the range 200 nL to 2.5 microL min(-1) by varying the voltage from 1 to 6 kV. The high pump pressure and the large current-free DC field also enabled the pump to act as an electro-spray interface with a downstream analytical instrument.

  4. Development of a miniaturized mass-flow meter for an axial flow blood pump based on computational analysis.

    PubMed

    Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu; Yamane, Takashi

    2011-09-01

    In order to monitor the condition of patients with implantable left ventricular assist systems (LVAS), it is important to measure pump flow rate continuously and noninvasively. However, it is difficult to measure the pump flow rate, especially in an implantable axial flow blood pump, because the power consumption has neither linearity nor uniqueness with regard to the pump flow rate. In this study, a miniaturized mass-flow meter for discharged patients with an implantable axial blood pump was developed on the basis of computational analysis, and was evaluated in in-vitro tests. The mass-flow meter makes use of centrifugal force produced by the mass-flow rate around a curved cannula. An optimized design was investigated by use of computational fluid dynamics (CFD) analysis. On the basis of the computational analysis, a miniaturized mass-flow meter made of titanium alloy was developed. A strain gauge was adopted as a sensor element. The first strain gauge, attached to the curved area, measured both static pressure and centrifugal force. The second strain gauge, attached to the straight area, measured static pressure. By subtracting the output of the second strain gauge from the output of the first strain gauge, the mass-flow rate was determined. In in-vitro tests using a model circulation loop, the mass-flow meter was compared with a conventional flow meter. Measurement error was less than ±0.5 L/min and average time delay was 0.14 s. We confirmed that the miniaturized mass-flow meter could accurately measure the mass-flow rate continuously and noninvasively. PMID:21537972

  5. Hydraulic pump

    SciTech Connect

    Polak, P.R.; Jantzen, D.E.

    1984-05-15

    This invention relates to an improved pump jack characterized by a hollow piston rod which telescopes down over the sucker rod to which it is clamped for reciprocating motion. The cylinder, in turn, is fastened in fixed position directly to the upper exposed end of the well casing. As fluid is introduced into the lower end of the cylinder it raises the piston into engagement with a pushrod housed in the upper cylinder head that lifts switch-actuating means associated therewith into a position operative to actuate a switch located adjacent thereto thereby causing the latter to change state and actuate a multi-function solenoid valve so as to cut off fluid flow to the cylinder. As gravity lowers the sucker rod and piston exhausting the hydraulic fluid therebeneath, an adjustable stop engages the pushrod from above so as to return it together with the switch-actuating means associated therewith to their original positions thereby resetting the switch to complete the operating cycle.

  6. Stirling Engine Heat Pump

    NASA Astrophysics Data System (ADS)

    Kagawa, Noboru

    Recent advances in the feasibility studies related to the Stirling engines and Stirling engine heat pumps which have been considered attractive due to their promising role in helping to solve the global environmental and energy problems,are reviewed. This article begins to describe the brief history of the Stirling engines and theoretical thermodynamic analysis of the Stirling cycle in order to understand several advantages on the Stirling engine. Furthermore,they could throw light on our question why the dream engines had not been promoted to practical applications during two hundred years. The present review shows that the Stirling engines with several unique advantages including 30 to 40% thermal efficiency and preferable exhaust characteristics,had been designed and constructed by recent tackling for the development of the advanced automobile and other applications using them. Based on the current state of art,it is being provided to push the Stirling engines combined with heat pumps based on the reversed Rankine cycle to the market. At present,however, many problems, especially for the durability, cost, and delicate engine parts must be enforced to solve. In addition,there are some possibilities which can increase the attractiveness of the Stirling engines and heat pumps. The review closes with suggestions for further research.

  7. A 3.3-to-25V all-digital charge pump based system with temperature and load compensation for avalanche photodiode cameras with fixed sensitivity

    NASA Astrophysics Data System (ADS)

    Mandai, S.; Charbon, E.

    2013-03-01

    This paper presents a digitally controlled charge pump (DCP) to supply high voltages, while ensuring temperature and load current independence of excess bias in cameras based on avalanche photodiodes. This is achieved through a single-photon avalanche diode (SPAD) based monitoring mechanism that continuously reconfigures the DCP using a feedback loop to compensate breakdown voltage variations by temperature and load current in real time. The sensitivity of the SPADs, or photon detection probability (PDP), is maintained to within 1.9% when the temperature shifts from 28°C to 65°C and the load current changes from 0 μA to 100 μA.

  8. Water Pump Development for the EVA PLSS

    NASA Technical Reports Server (NTRS)

    Schuller, Michael; Kurwitz, Cable; Goldman, Jeff; Morris, Kim; Trevino, Luis

    2009-01-01

    This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design, fabricate, and test a preflight prototype pump for use in the Extravehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump will accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting noncondensable gas without becoming "air locked." The chosen pump design consists of a 28 V DC, brushless, sealless, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. Although the planned flight unit will use a sensorless motor with custom designed controller, the preflight prototype to be provided for this project incorporates Hall effect sensors, allowing an interface with a readily available commercial motor controller. This design approach reduced the cost of this project and gives NASA more flexibility in future PLSS laboratory testing. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES will simulate the vacuum environment in which the flight pump will operate. Testing will verify that the pump meets design requirements for range of flow rates, pressure rise, power consumption, working fluid temperature, operating time, and restart capability. Pump testing is currently

  9. Pump-tuned deep-infrared femtosecond optical parametric oscillator across 6-7  μm based on CdSiP2.

    PubMed

    Chaitanya Kumar, S; Esteban-Martin, A; Santana, A; Zawilski, K T; Schunemann, P G; Ebrahim-Zadeh, M

    2016-07-15

    We report on a high-power femtosecond optical parametric oscillator (OPO) at 80 MHz repetition rate, tunable across 6318-7061 nm in the deep-infrared (deep-IR) using pump wavelength tuning. The OPO, based on CdSiP2 (CSP), is synchronously pumped by a commercial Ti:sapphire-pumped femtosecond OPO in the near-IR, enabling rapid static tuning of the CSP OPO with minimal adjustments to its cavity length. The deep-IR CSP OPO provides as much as 32 mW of average idler power at 6808 nm with spectral bandwidth >1000  nm (at -10  dB level) across the tuning range. By implementing intracavity dispersion control, near-transform-limited signal pulses of ∼100  fs duration with smooth single-peak spectrum are achieved at 1264 nm, corresponding to an idler wavelength at 6440 nm. To the best of our knowledge, this is the first time such practical idler powers in the deep-IR have been generated from a dispersion-compensated CSP femtosecond OPO at sub-100 MHz repetition rate.

  10. Pump-tuned deep-infrared femtosecond optical parametric oscillator across 6-7  μm based on CdSiP2.

    PubMed

    Chaitanya Kumar, S; Esteban-Martin, A; Santana, A; Zawilski, K T; Schunemann, P G; Ebrahim-Zadeh, M

    2016-07-15

    We report on a high-power femtosecond optical parametric oscillator (OPO) at 80 MHz repetition rate, tunable across 6318-7061 nm in the deep-infrared (deep-IR) using pump wavelength tuning. The OPO, based on CdSiP2 (CSP), is synchronously pumped by a commercial Ti:sapphire-pumped femtosecond OPO in the near-IR, enabling rapid static tuning of the CSP OPO with minimal adjustments to its cavity length. The deep-IR CSP OPO provides as much as 32 mW of average idler power at 6808 nm with spectral bandwidth >1000  nm (at -10  dB level) across the tuning range. By implementing intracavity dispersion control, near-transform-limited signal pulses of ∼100  fs duration with smooth single-peak spectrum are achieved at 1264 nm, corresponding to an idler wavelength at 6440 nm. To the best of our knowledge, this is the first time such practical idler powers in the deep-IR have been generated from a dispersion-compensated CSP femtosecond OPO at sub-100 MHz repetition rate. PMID:27420534

  11. A chemical heat pump based on the reaction of calcium chloride and methanol for solar heating, cooling and storage

    NASA Astrophysics Data System (ADS)

    Offenhartz, P. O.

    1981-03-01

    An engineering development test prototype of the CaCl2-CheOH chemical heat pump was tested. The unit, which has storage capacity in excess of 100,000 BTU, completed over 100 full charge-discharge cycles. Cycling data show that the rate of heat pumping depends strongly on the absorber-evaporator temperature difference. These rates are more than adequate for solar heating or for solar cooling using dry ambient air heat rejection. Performance degradation after 100 cycles, expressed as a contact resistance, was less than 2 C. The heat exchangers showed some warpage due to plastic flow of the salt, producing the contact resistance. The experimental COP for cooling was 0.52, close to the theoretically predicted value.

  12. Multiple pump housing

    DOEpatents

    Donoho, II, Michael R.; Elliott; Christopher M.

    2010-03-23

    A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

  13. Method for controlling powertrain pumps

    DOEpatents

    Sime, Karl Andrew; Spohn, Brian L; Demirovic, Besim; Martini, Ryan D; Miller, Jean Marie

    2013-10-22

    A method of controlling a pump supplying a fluid to a transmission includes sensing a requested power and an excess power for a powertrain. The requested power substantially meets the needs of the powertrain, while the excess power is not part of the requested power. The method includes sensing a triggering condition in response to the ability to convert the excess power into heat in the transmission, and determining that an operating temperature of the transmission is below a maximum. The method also includes determining a calibrated baseline and a dissipation command for the pump. The calibrated baseline command is configured to supply the fluid based upon the requested power, and the dissipation command is configured to supply additional fluid and consume the excess power with the pump. The method operates the pump at a combined command, which is equal to the calibrated baseline command plus the dissipation command.

  14. Physiologically Based Pharmacokinetic Modeling for Substitutability Analysis of Venlafaxine Hydrochloride Extended-Release Formulations Using Different Release Mechanisms: Osmotic Pump Versus Openable Matrix.

    PubMed

    Lin, Ho-Pi; Sun, Dajun; Zhang, Xinyuan; Wen, Hong

    2016-10-01

    A Food and Drug Administration-approved generic oral product of venlafaxine hydrochloride (HCl) extended-release (ER) tablets has used a release mechanism based on an openable matrix, which is different from the push-pull osmotic pump system of its reference-listed drug. In an extreme case, a delay in the bursting of the openable matrix may be considered a product failure mode that alters the intended profile of systemic exposure. A physiologically based pharmacokinetic absorption model was established and verified to simulate the pharmacokinetic profiles after a single-dose oral administration of ER venlafaxine HCl tablets based on an osmotic pump or openable matrix design. This model adequately predicted the observed human mean pharmacokinetic metrics with <20% difference between the predicted and observed data. Based on the modeling and simulation results, Cmax and AUCt of the venlafaxine openable matrix tablets were entirely within the bioequivalence acceptance limits (i.e., 80%-125%) when the lag time varied from 0 to 4 h and using drug-release profiles under most dissolution conditions. The results indicated that a bioinequivalence risk is minimal for a delayed onset of drug release from the approved generic venlafaxine HCl ER tablets with an openable matrix design, supporting its substitutability to the reference product. PMID:27449228

  15. A compact spin-exchange optical pumping system for 3He polarization based on a solenoid coil, a VBG laser diode, and a cosine theta RF coil

    NASA Astrophysics Data System (ADS)

    Lee, Sungman; Kim, Jongyul; Moon, Myung Kook; Lee, Kye Hong; Lee, Seung Wook; Ino, Takashi; Skoy, Vadim R.; Lee, Manwoo; Kim, Guinyun

    2013-02-01

    For use as a neutron spin polarizer or analyzer in the neutron beam lines of the HANARO (High-flux Advanced Neutron Application ReactOr) nuclear research reactor, a 3He polarizer was designed based on both a compact solenoid coil and a VBG (volume Bragg grating) diode laser with a narrow spectral linewidth of 25 GHz. The nuclear magnetic resonance (NMR) signal was measured and analyzed using both a built-in cosine radio-frequency (RF) coil and a pick-up coil. Using a neutron transmission measurement, we estimated the polarization ratio of the 3He cell as 18% for an optical pumping time of 8 hours.

  16. High power, diffraction limited picosecond oscillator based on Nd:GdVO4 bulk crystal with σ polarized in-band pumping.

    PubMed

    Lin, Hua; Guo, Jie; Gao, Peng; Yu, Hai; Liang, Xiaoyan

    2016-06-27

    We report on a high power passively mode-locked picosecond oscillator based on Nd:GdVO4 crystal with σ polarized in-band pumping. Thermal gradient and thermal aberration was greatly decreased with proposed configuration. Maximum output power of 37 W at 81 MHz repetition rate with 19.3 ps pulse duration was achieved directly from Nd:GdVO4 oscillator, corresponding to 51% optical efficiency. The oscillator maintained diffraction limited beam quality of M2 < 1.05 at different output coupling with pulse duration between 11.2 ps to 19.3 ps.

  17. Diode-pumped Nd:YVO4 laser emitting at 1074 nm based on the 4 F 3/2-4 I 11/2 transition

    NASA Astrophysics Data System (ADS)

    Ma, Z. Y.; Li, C. L.; Liang, W.; Wang, J. G.

    2011-09-01

    We report a diode-pumped Nd:YVO4 laser emitting at 1074 nm, based on the 4 F 3/2-4 I 11/2 transition, generally used for a 1064 nm emission. A power of 323 mW at 1074 nm has been achieved in continuouswave (CW) operation with a fiber-coupled laser diode emitting 18.2 W at 808 nm. Intracavity second-harmonic generation in CW mode has also been demonstrated with a power of 18 mW at 537 nm by using a LiB3O5 (LBO) nonlinear crystal.

  18. Alternative backing up pump for turbomolecular pumps

    DOEpatents

    Myneni, Ganapati Rao

    2003-04-22

    As an alternative to the use of a mechanical backing pump in the application of wide range turbomolecular pumps in ultra-high and extra high vacuum applications, palladium oxide is used to convert hydrogen present in the evacuation stream and related volumes to water with the water then being cryo-pumped to a low pressure of below about 1.e.sup.-3 Torr at 150.degree. K. Cryo-pumping is achieved using a low cost Kleemenco cycle cryocooler, a somewhat more expensive thermoelectric cooler, a Venturi cooler or a similar device to achieve the required minimization of hydrogen partial pressure.

  19. Femtosecond wavelength-tunable OPCPA system based on picosecond fiber laser seed and picosecond DPSS laser pump.

    PubMed

    Danilevičius, R; Zaukevičius, A; Budriūnas, R; Michailovas, A; Rusteika, N

    2016-07-25

    We present a compact and stable femtosecond wavelength-tunable optical parametric chirped pulse amplification (OPCPA) system. A novel OPCPA front-end was constructed using a multi-channel picosecond all-in-fiber source for seeding DPSS pump laser and white light supercontinuum generation. Broadband chirped pulses were parametrically amplified up to 1 mJ energy and compressed to less than 40 fs duration. Pulse wavelength tunability in the range from 680 nm to 930 nm was experimentally demonstrated. PMID:27464199

  20. Second generation high data-rate inter-orbit link based on diode-pumped Nd:YAG laser technology

    NASA Astrophysics Data System (ADS)

    Sontag, H.; Johann, U.; Pribil, K.

    1991-05-01

    The SILEX experimental program is concerned with demonstrating the technologies of an optical communications link between two satellites; in order to expand system capabilities to the high data rates required for future LEO-GEO interorbit links, a detailed design study has been conducted for a system predicated on diode-pumped Nd:YAG laser technology. Even with telescopes whose apertures are less than 10 cm on the LEO satellite, and transmitter powers of less than 1 W, system transmission performance is greater than 1 Gbit/sec.

  1. An experimental study on pump clogging

    NASA Astrophysics Data System (ADS)

    Isono, M.; Nohmi, M.; Uchida, H.; Kawai, M.; Kudo, H.; Kawahara, T.; Miyagawa, K.; Saito, S.

    2014-03-01

    For sewage pump that various foreign substance is flowed into, anti-clogging performance is a factor as important as pump efficiency in order to avoid clogging trouble by foreign substance. Many investigations about pump inner flow and pump efficiency estimation have been carried out conventionally in order to realize coexistence with anti-clogging performance and pump performance. And these results have been reflected in construction of the running water section design method. As a index of anti-clogging performance, "impeller passage diameter" which is diameter of spherical solid that can pass through the pump is used widely. And there are various type of the sewage pump which have large impeller passage diameter. However real cause of clog is not a solid, and it is fibrous material such as towel and clothes, vinyl and paper diaper. In most case these material accumulate in the pump, so that clog is occurred. In this study, for the purpose of quantification of anti-clogging performance against fibrous materials, the factor that affect to clogging of pump was investigated by pump model test using a string. The test is done based on Taguchi method. In this test, type of the pump model, diameter of the string, material of the string, length of the string and flow rate are selected for the factor, and the effect that they have on the clogging of the pump was investigated. As a result of this test, it was made clear that length of the string has a strong influence on the clogging of the pump. And from the result of this test, evaluation method of anti-clogging performance of the pump against fibrous material by using string was considered. According to the result of above test based on Taguchi method, it was assumed that quantification of anti-clogging performance against fibrous materials is possible by flowing plural strings into the pump and calculating the probability of passing. Plurality sewage pumps of different types were evaluated based on this assumption

  2. Tritium gas transfer pump development

    SciTech Connect

    Sharpe, C.L.

    1985-01-01

    Non-lubricated, hermetically sealed pumps for tritium service have been selected to replace Sprengel pumps in the existing Tritium Facility. These pumps will be the primary gas-transfer pumps in the planned Replacement Tritium Facility. The selected pumps are Metal Bellows Corporation's bellows pumps and Normetex scroll pumps. Pumping range for a Normetex/Metal Bellows system is from 0.01 torr suction to 2300 torr discharge. Performance characteristics of both pumps are presented. 10 figs.

  3. Novel limiter pump topologies

    SciTech Connect

    Schultz, J.H.

    1981-01-01

    The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topolgies are suggested which allow high erosion without limiter failure.

  4. Gas pump with movable gas pumping panels

    DOEpatents

    Osher, J.L.

    Apparatus for pumping gas continuously a plurality of articulated panels of getter material, each of which absorbs gases on one side while another of its sides is simultaneously reactivated in a zone isolated by the panels themselves from a working space being pumped.

  5. Proton pump inhibitors

    MedlinePlus

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  6. Insulin pump (image)

    MedlinePlus

    The catheter at the end of the insulin pump is inserted through a needle into the abdominal ... with diabetes. Dosage instructions are entered into the pump's small computer and the appropriate amount of insulin ...

  7. Photovoltaic pump systems

    NASA Astrophysics Data System (ADS)

    Klockgether, J.; Kiessling, K. P.

    1983-09-01

    Solar pump systems for the irrigation of fields and for water supply in regions with much sunshine are discussed. For surface water and sources with a hoisting depth of 12 m, a system with immersion pumps is used. For deep sources with larger hoisting depths, an underwater motor pump was developed. Both types of pump system meet the requirements of simple installation and manipulation, safe operation, maintenance free, and high efficiency reducing the number of solar cells needed.

  8. 500.5-nm blue-green laser based on sum-frequency mixing of diode pumped neodymium lasers

    NASA Astrophysics Data System (ADS)

    Wang, S. F.; Na, Y. X.

    2011-07-01

    We report for the first time a continuous-wave (CW) coherent radiation at 500.5 nm by intracavity sum-frequency generation of 1063 nm Nd:GdVO4 laser and 946 nm Nd:YAG laser. Blue-green laser is obtained by using a doubly cavity, type-II critical phase matching KTiOPO4 (KTP) crystal sum-frequency mixing. With total pump power of 27.8 W, TEM00 mode blue-green laser at 500.5 nm of 421 mW is obtained. At the output power level of 421 mW, the blue-green power stability is better than 2.8% and laser beam quality M 2 factor is 1.37.

  9. Rotary magnetic heat pump

    DOEpatents

    Kirol, Lance D.

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  10. Multiwell pumping device

    SciTech Connect

    Dysarz, E.D.

    1987-06-30

    This patent describes a balanced pumping apparatus for pumping two laterally spaced wells comprising: a left conductor on a left well; a right conductor on a right the well; a left pump casing inside the well conductor; a right pump casing inside the right well conductor; a left sucker rod inside the left pump casing; a right sucker rod inside the right pump casing; flexible linkage means for attachment to the top ends of the right sucker rod and left sucker rod; a drive motor with a rotating shaft; a drive sprocket rotatably engaging the flexible linkage means; a separate pump casing flange attached to the upper section of each well conductors; a separate upper flange attached to the upper section of each pump casing and positioned at an axial location above the point attached to the pump casing; a separate transition piece attached to the top of each pump casing flange; a separate pump support attached to the top of each transition piece; a plate-like structural support means placed in a vertical plane above the well conductors and supporting the drive motor, the drive sprocket, the flexible linkage means, and the sucker rods; a structural load transfer means connecting the plate-like structural support means to the well conductors; a motor control unit for supporting itself and controlling the drive motor; and a separate shaft extending across each pump support.

  11. Types of Breast Pumps

    MedlinePlus

    ... uses batteries or a cord plugged into an electrical outlet to power a small motorized pump that creates suction to ... pumping. Because these breast pumps rely on a power source, women who use ... situations when electricity or extra batteries may not be available. If ...

  12. Rotary magnetic heat pump

    DOEpatents

    Kirol, L.D.

    1987-02-11

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  13. Green pumped Alexandrite lasers

    NASA Astrophysics Data System (ADS)

    Kuper, Jerry W.; Brown, David C.

    2005-04-01

    Initial experiments with pulsed and CW pumping an alexandrite laser rod at 532 nm are presented. This pumping architecture holds promise for the production of scalable diode-pumped, tunable alexandrite laser systems operating in the near infrared (750 nm), and the ultraviolet (375 and 250 nm) spectral regions.

  14. Polarization-insensitive wavelength-division-multiplexing optical millimeter wave generation based on copolarized pump four wave mixing in a semiconductor optical amplifier.

    PubMed

    Li, Ying; Zheng, Zhiwei; Chen, Lin; Wen, Shuangchun; Fan, Dianyuan

    2009-06-01

    We proposed a novel scheme to generate polarization-insensitive optical millimeter-wave (mm-wave) wavelength-division-multiplexing (WDM) signals by using an external modulator and a semiconductor optical amplifier (SOA). In the scheme, two copolarized pumps and a WDM signal are mixed in the SOA based on four wave mixing (FWM), and the quadruple frequency mm-wave signal, similar to the single-sideband mm-wave signal, is obtained by using an optical filter to remove one sideband after FWM. Based on the scheme, we have experimentally demonstrated the generation of a two-channel 2.5 Gbit/s WDM optical mm-wave signal with a repetitive frequency up to 40 GHz by a 10 GHz local oscillator, and the downstream signal delivery over a 20 km fiber with power penalty less than 1 dB.

  15. Toward an ultra-broadband emission source based on the bismuth and erbium co-doped optical fiber and a single 830nm laser diode pump.

    PubMed

    Zhang, Jianzhong; Sathi, Zinat M; Luo, Yanhua; Canning, John; Peng, Gang-Ding

    2013-03-25

    We demonstrate a broadband optical emission from Bi/Er co-doped fiber and a single 830nm laser diode pump. The ultra-broadband mechanism is studied and discussed in details based on a combination of experimental measurements, including luminescence, differential luminescence and ESA, on fiber samples of different Bi and Er concentrations. The Er co-doping in Bi doped fiber is found to be effective for broadband emission, by enhancing not only luminescence at C and L bands but also that at O and shorter wavelength bands. The luminescence intensity between 1100 and 1570nm is over -45dBm/5nm in single mode fiber using a few meters of Bi/Er co-doped fiber and offers a modest ~40dB dynamic range and a broad bandwidth of ~470nm for an OSA based spectral measurement.

  16. Floating intake reduces pump damage

    SciTech Connect

    Kronig, A.

    1993-12-31

    The solution to a costly sand erosion problem at the Grande Dixence hydroelectric project in Switzerland turned out to be as simple as a floating pump. The 726-MW Grande Dixence project drains a 350-square-kilometer reach of the Zermatt and Herens valleys in the southwestern Swiss Alps. About half of the drainage area is covered by active glaciers. Because the glaciers in Zermatt Valley are so low in altitude, their water is collected in Z`mutt Reservoir at the base of the Matterhorn, then pumped up 500 meters for transport to the main Grande Disence Reservoir near Sion. The glacier water is heavily laden with sand. In spite of a gravel pass and a desilter, the 700,000-acubic-meter Z`mutt Reservoir receives large quantities of sand. The sand tends to remain in solution because of the low water temperatures (1 to 2 degrees Centigrade). In the original intake system, the sand would be sucked into the pump intakes, causing extensive erosion to the pump wheels and an expensive yearly program of repair. (Pump damage averaged 200,000 Swiss Francs ($284,000 U.S.) per year between 1980 and 1985.)

  17. Jet pump assisted artery

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A procedure for priming an arterial heat pump is reported; the procedure also has a means for maintaining the pump in a primed state. This concept utilizes a capillary driven jet pump to create the necessary suction to fill the artery. Basically, the jet pump consists of a venturi or nozzle-diffuser type constriction in the vapor passage. The throat of this venturi is connected to the artery. Thus vapor, gas, liquid, or a combination of the above is pumped continuously out of the artery. As a result, the artery is always filled with liquid and an adequate supply of working fluid is provided to the evaporator of the heat pipe.

  18. Liquid metal electric pump

    DOEpatents

    Abbin, Joseph P.; Andraka, Charles E.; Lukens, Laurance L.; Moreno, James B.

    1992-01-01

    An electrical pump for pumping liquid metals to high pressures in high temperature environments without the use of magnets or moving mechanical parts. The pump employs a non-porous solid electrolyte membrane, typically ceramic, specific to the liquid metal to be pumped. A DC voltage is applied across the thickness of the membrane causing ions to form and enter the membrane on the electrically positive surface, with the ions being neutralized on the opposite surface. This action provides pumping of the liquid metal from one side of the non-porous solid electrolyte membrane to the other.

  19. Surface micromachined electrostatically actuated micro peristaltic pump.

    PubMed

    Xie, Jun; Shih, Jason; Lin, Qiao; Yang, Bozhi; Tai, Yu-Chong

    2004-10-01

    An electrostatically actuated micro peristaltic pump is reported. The micro pump is entirely surface micromachined using a multilayer parylene technology. Taking advantage of the multilayer technology, the micro pump design enables the pumped fluid to be isolated from the electric field. Electrostatic actuation of the parylene membrane using both DC and AC voltages was demonstrated and applied to fluid pumping based on a 3-phase peristaltic sequence. A maximum flow rate of 1.7 nL min(-1) and an estimated pumping pressure of 1.6 kPa were achieved at 20 Hz phase frequency. A dynamic analysis was also performed with a lumped-parameter model for the peristaltic pump. The analysis results allow a quantitative understanding of the peristaltic pumping operation, and correctly predict the trends exhibited by the experimental data. The small footprint of the micro pump is well suited for large-scale integration of microfluidics. Moreover, because the same platform technology has also been used to fabricate other devices (e.g. valves, electrospray ionization nozzles, filters and flow sensors), the integration of these different devices can potentially lead to versatile and functional micro total analysis systems (microTAS).

  20. Absorption heat pump for space applications

    NASA Technical Reports Server (NTRS)

    Nguyen, Tuan; Simon, William E.; Warrier, Gopinath R.; Woramontri, Woranun

    1993-01-01

    In the first part, the performance of the Absorption Heat Pump (AHP) with water-sulfuric acid and water-magnesium chloride as two new refrigerant-absorbent fluid pairs was investigated. A model was proposed for the analysis of the new working pairs in a heat pump system, subject to different temperature lifts. Computer codes were developed to calculate the Coefficient of Performance (COP) of the system with the thermodynamic properties of the working fluids obtained from the literature. The study shows the potential of water-sulfuric acid as a satisfactory replacement for water-lithium bromide in the targeted temperature range. The performance of the AHP using water-magnesium chloride as refrigerant-absorbent pair does not compare well with those obtained using water-lithium bromide. The second part concentrated on the design and testing of a simple ElectroHydrodynamic (EHD) Pump. A theoretical design model based on continuum electromechanics was analyzed to predict the performance characteristics of the EHD pump to circulate the fluid in the absorption heat pump. A numerical method of solving the governing equations was established to predict the velocity profile, pressure - flow rate relationship and efficiency of the pump. The predicted operational characteristics of the EHD pump is comparable to that of turbomachinery hardware; however, the overall efficiency of the electromagnetic pump is much lower. An experimental investigation to verify the numerical results was conducted. The pressure - flow rate performance characteristics and overall efficiency of the pump obtained experimentally agree well with the theoretical model.

  1. An overview of multiphase helicoaxial pumps

    SciTech Connect

    Falcimaigne, J.

    1996-02-01

    The helicoaxial concept developed by the Inst. Francais du Petrole (IFP) is one of two types of multiphase pumps extensively tested on fields and now used commercially. Helicoaxial pumps are rotodynamic turbomachines that are, in fact, hybrids between pumps and axial compressors. Helicoaxial pumps are based on special patented hydraulics designed to limit the phase separation that occurs in two-phase flow with conventional centrifugal pumps that produce a tremendous head loss. Developers have carried out extensive research and testing on actual production sites to develop helicoaxial pumping. The favorable results obtained so far confirm the soundness and versatility of the technology over a wide range of operating conditions. Helicoaxial pumps cover a larger domain of application than anticipated some years ago. They can be used with high gas volume fraction (94 to 95%) and/or low suction pressures. The pumps` inherent low weight should make them particularly attractive for large flow rates and offshore operations. Helicoaxial pumps are reliable products, technically and commercially read for field deployment.

  2. Nuclear pumped gas laser research

    NASA Technical Reports Server (NTRS)

    Thom, K.

    1976-01-01

    Nuclear pumping of lasers by fission-fragments from nuclear chain reactions is discussed. Application of the newly developed lasers to spacecraft propulsion or onboard power, to lunar bases for industrial processing, and to earth for utilization of power without pollution and hazards is envisioned. Emphasis is placed on the process by which the fission-fragement kinetic energy is converted into laser light.

  3. Strategy Plan A Methodology to Predict the Uniformity of Double-Shell Tank Waste Slurries Based on Mixing Pump Operation

    SciTech Connect

    J.A. Bamberger; L.M. Liljegren; P.S. Lowery

    1990-12-01

    This document presents an analysis of the mechanisms influencing mixing within double-shell slurry tanks. A research program to characterize mixing of slurries within tanks has been proposed. The research program presents a combined experimental and computational approach to produce correlations describing the tank slurry concentration profile (and therefore uniformity) as a function of mixer pump operating conditions. The TEMPEST computer code was used to simulate both a full-scale (prototype) and scaled (model) double-shell waste tank to predict flow patterns resulting from a stationary jet centered in the tank. The simulation results were used to evaluate flow patterns in the tank and to determine whether flow patterns are similar between the full-scale prototype and an existing 1/12-scale model tank. The flow patterns were sufficiently similar to recommend conducting scoping experiments at 1/12-scale. Also, TEMPEST modeled velocity profiles of the near-floor jet were compared to experimental measurements of the near-floor jet with good agreement. Reported values of physical properties of double-shell tank slurries were analyzed to evaluate the range of properties appropriate for conducting scaled experiments. One-twelfth scale scoping experiments are recommended to confirm the prioritization of the dimensionless groups (gravitational settling, Froude, and Reynolds numbers) that affect slurry suspension in the tank. Two of the proposed 1/12-scale test conditions were modeled using the TEMPEST computer code to observe the anticipated flow fields. This information will be used to guide selection of sampling probe locations. Additional computer modeling is being conducted to model a particulate laden, rotating jet centered in the tank. The results of this modeling effort will be compared to the scaled experimental data to quantify the agreement between the code and the 1/12-scale experiment. The scoping experiment results will guide selection of parameters to be

  4. Microfluidic Pumps Containing Teflon [Trademark] AF Diaphragms

    NASA Technical Reports Server (NTRS)

    Willis, Peter; White, Victor; Grunthaner, Frank; Ikeda, Mike; Mathies, Richard A.

    2009-01-01

    Microfluidic pumps and valves based on pneumatically actuated diaphragms made of Teflon AF polymers are being developed for incorporation into laboratory-on-a-chip devices that must perform well over temperature ranges wider than those of prior diaphragm-based microfluidic pumps and valves. Other potential applications include implanted biomedical microfluidic devices, wherein the biocompatability of Teflon AF polymers would be highly advantageous. These pumps and valves have been demonstrated to function stably after cycling through temperatures from -125 to 120 C. These pumps and valves are intended to be successors to similar prior pumps and valves containing diaphragms made of polydimethylsiloxane (PDMS) [commonly known as silicone rubber]. The PDMS-containing valves ae designed to function stably only within the temperature range from 5 to 80 C. Undesirably, PDMS membranes are somwehat porous and retain water. PDMS is especially unsuitable for use at temperatures below 0 C because the formation of ice crystals increases porosity and introduces microshear.

  5. Demonstration of motionless Knudsen pump based micro-gas chromatography featuring micro-fabricated columns and on-column detectors.

    PubMed

    Liu, Jing; Gupta, Naveen K; Wise, Kensall D; Gianchandani, Yogesh B; Fan, Xudong

    2011-10-21

    This paper reports the investigation of a micro-gas chromatography (μGC) system that utilizes an array of miniaturized motionless Knudsen pumps (KPs) as well as microfabricated separation columns and optical detectors. A prototype system was built to achieve a flow rate of 1 mL min(-1) and 0.26 mL min(-1) for helium and dry air, respectively, when they were used as carrier gas. This system was then employed to evaluate GC performance compromises and demonstrate the ability to separate and detect gas mixtures containing analytes of different volatilities and polarities. Furthermore, the use of pressure programming of the KP array was demonstrated to significantly shorten the analysis time while maintaining a high detection resolution. Using this method, we obtained a high resolution detection of 5 alkanes of different volatilities within 5 min. Finally, we successfully detected gas mixtures of various polarities using a tandem-column μGC configuration by installing two on-column optical detectors to obtain complementary chromatograms.

  6. Preliminary conceptual design and weight of a one-megawatt space-based laser power station utilizing a solar-pumped iodine lasant

    NASA Technical Reports Server (NTRS)

    De Young, R. J.; Walker, G. H.; Williams, M. D.; Schuster, G. L.; Conway, E. J.

    1987-01-01

    A preliminary conceptual design of a space-based solar-pumped iodide laser emitting 1 MW of laser power for space-to-space power transmission is described. A near-parabolic solar collector focuses sunlight onto the t-C4F9I lasant within a transverse-flow optical cavity. Using waste heat, a thermal system supplies compressor and auxiliary power. The major system components are designed with weight estimates assigned. In particular, it is found that laser efficiency is not a dominant weight factor, the dominant factor being the laser transmission optics. The station mass is 92,000 kg, requiring approximately eight Shuttle flights to LEO, where an orbital transfer vehicle can transport it to the final altitude of 6378 km.

  7. A high-repetition rate scheme for synchrotron-based picosecond laser pump/x-ray probe experiments on chemical and biological systems in solution

    SciTech Connect

    Lima, Frederico A.; Milne, Christopher J.; Amarasinghe, Dimali C. V.; Rittmann-Frank, Mercedes Hannelore; Veen, Renske M. van der; Reinhard, Marco; Pham, Van-Thai; Karlsson, Susanne; Mourik, Frank van; Chergui, Majed; Johnson, Steven L.; Grolimund, Daniel; Borca, Camelia; Huthwelker, Thomas; Janousch, Markus; Abela, Rafael

    2011-06-15

    We present the extension of time-resolved optical pump/x-ray absorption spectroscopy (XAS) probe experiments towards data collection at MHz repetition rates. The use of a high-power picosecond laser operating at an integer fraction of the repetition rate of the storage ring allows exploitation of up to two orders of magnitude more x-ray photons than in previous schemes based on the use of kHz lasers. Consequently, we demonstrate an order of magnitude increase in the signal-to-noise of time-resolved XAS of molecular systems in solution. This makes it possible to investigate highly dilute samples at concentrations approaching physiological conditions for biological systems. The simplicity and compactness of the scheme allows for straightforward implementation at any synchrotron beamline and for a wide range of x-ray probe techniques, such as time-resolved diffraction or x-ray emission studies.

  8. Optimization of a Raman/EDFA hybrid amplifier based on dual-order stimulated Raman scattering using a single-pump

    NASA Astrophysics Data System (ADS)

    Li, Zhaohui; Zhao, Chun-Liu; Wen, Yang Jing; Lu, Chao; Wang, Yixin; Chen, Jian

    2006-09-01

    Based on dual-order stimulated Raman scattering (SRS) of a single 1395 nm Raman fiber laser in 75 km single mode fiber and its corresponding dispersion compensation module, a hybrid Raman/Erbium doped fiber amplifier (EDFA) for long wavelength band (L-band) amplification is realized by inserting a segment of EDF within the span. By comparing the performance of gain and noise in four hybrid amplifiers with different span configurations, we find that the distribution of the secondary L-band amplification obtained from the EDF along the link has a great influence on the performance of the hybrid amplifier. Both gain and noise performance of hybrid amplifier can be improved significantly by optimizing the location of the EDF. Moreover, we can extend the flat gain bandwidth from L-band to central wavelength band (C-band) plus L-band by recycling the residual first-order SRS to pump a segment of EDF with proper length.

  9. Ultra-low phase-noise microwave generation using a diode-pumped solid-state laser based frequency comb and a polarization-maintaining pulse interleaver.

    PubMed

    Portuondo-Campa, Erwin; Buchs, Gilles; Kundermann, Stefan; Balet, Laurent; Lecomte, Steve

    2015-12-14

    We report ultra-low phase-noise microwave generation at a 9.6 GHz carrier frequency from optical frequency combs based on diode-pumped solid-state lasers emitting at telecom wavelength and referenced to a common cavity-stabilized continuous-wave laser. Using a novel fibered polarization-maintaining pulse interleaver, a single-oscillator phase-noise floor of -171 dBc/Hz at 10 MHz offset frequency has been measured with commercial PIN InGaAs photodiodes, constituting a record for this type of detector. Also, a direct optical measurement of the stabilized frequency combs' timing jitter was performed using a balanced optical cross correlator, allowing for an identification of the origin of the phase-noise limitations in the system. PMID:26699033

  10. 11. VIEW SOUTH OF INTERIOR OF PUMP HOUSE NEAR SOUTHEAST ...

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

    11. VIEW SOUTH OF INTERIOR OF PUMP HOUSE NEAR SOUTHEAST CORNER OF BUILDING 7; PUMP WAS MOUNTED ON BASE AT CENTER OF PHOTO; PUMP WAS DRIVEN BY AN ELECTRIC MOTOR (STATOR REMAINS AT BOTTOM CENTER) AND COULD ALSO BE DRIVEN BY A TERRY STEAM TURBINE AT CENTER - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

  11. Consensus evidence-based guidelines for use of insulin pump therapy in the management of diabetes as per Indian clinical practice.

    PubMed

    Kesavadev, Jothydev; Jain, Sunil M; Muruganathan, A; Das, Ashok Kumar

    2014-07-01

    The use of insulin pump in diabetes is likely to increase with recent advances in technology. Although the evidence for the superiority of pumps over multiple daily injections (MDI) is inconsistent, data from accumulating uncontrolled studies indicate greater reductions in glycated haemoglobin in patients switching to continuous subcutaneous insulin infusion (CSII) from MDI therapy. Due to the variability in insulin requirements and sensitivity to CSII pumps, hyperglycaemia in these patients is managed by endocrinologists using individualised therapy. A panel of experts reviewed the existing guidelines and framed recommendations specific to the clinical practice in Indian conditions for use of CSII pumps in the management of hyperglycaemia. Selection of right patient with basic education, motivation and learning skills are essential for successful implementation of CSII therapy with sophisticated programmes. Rapid acting insulin analogues with better pharmacokinetic and pharmacodynamic profile, physical and chemical stability and compatibility with most commercially available insulin pumps are preferred over regular insulin to achieve safe and stable glycaemic control. Further, educating pump users on proper use of CSII pumps, insulin dose adjustments, and handling of accessories are recommended in the current consensus guidelines. Practice of self-monitoring of blood glucose and glycated haemoglobin levels are essential to adjust insulin dosage for the management of diabetes. Use of CSII pumps in special patient populations should be carefully assessed and initiated by endocrinologist. The proposed guidelines can form a basis for use of CSII pumps in the management of hyperglycaemia in the Indian scenario. PMID:25668935

  12. Pump isolation valve

    DOEpatents

    Kinney, Calvin L.; Wetherill, Todd M.

    1983-08-02

    The pump isolation valve provides a means by which the pump may be selectively isolated from the remainder of the coolant system while being compatible with the internal hydraulic arrangement of the pump during normal operation of the pump. The valve comprises a valve cylinder disposed around the pump and adjacent to the last pump diffuser with a turning vane attached to the lower end of the valve cylinder in a manner so as to hydraulically match with the discharge diffuser. The valve cylinder is connected to a drive means for sliding the valve cylinder relative to the diffuser support cylinder so as to block flow in either direction through the discharge diffuser when the valve is in the closed position and to aid in the flow of the coolant from the discharge diffuser by means of the turning vane when the valve is in the open position.

  13. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J. (Inventor); Akkerman, James W. (Inventor); Aber, Greg S. (Inventor); Vandamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1993-01-01

    A rotary blood pump is presented. The pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial, and radial clearances of the blades associated with the flow straightener, inducer portion, impeller portion, and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with crosslinked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  14. DIRECT CURRENT ELECTROMAGNETIC PUMP

    DOEpatents

    Barnes, A.H.

    1957-11-01

    An improved d-c electromagnetic pump is presented in which the poles, and consequently the magetic gap at the poles, are tapered to be wider at the upstream end. In addition, the cross section of the tube carryiQ the liquid metal is tapered so that the velocity of the pumped liquid increases in the downstream direction at a rate such that the counter-induced voltage in the liquid metal remains constant as it traverses the region between the poles. This configuration compensates for the distortion of the magnetic field caused by the induced voltage that would otherwise result in the lowering of the pumping capacity. This improved electromagnetic pump as practical application in the pumping of liquid metal coolants for nuclear reactors where conventional positive displacement pumps have proved unsatisfactory due to the high temperatures and the corrosive properties of the liquid metals involved.

  15. Electrokinetic pumps and actuators

    SciTech Connect

    Phillip M. Paul

    2000-03-01

    Flow and ionic transport in porous media are central to electrokinetic pumping as well as to a host of other microfluidic devices. Electrokinetic pumping provides the ability to create high pressures (to over 10,000 psi) and high flow rates (over 1 mL/min) with a device having no moving parts and all liquid seals. The electrokinetic pump (EKP) is ideally suited for applications ranging from a high pressure integrated pump for chip-scale HPLC to a high flow rate integrated pump for forced liquid convection cooling of high-power electronics. Relations for flow rate and current fluxes in porous media are derived that provide a basis for analysis of complex microfluidic systems as well as for optimization of electrokinetic pumps.

  16. Detection of pump degradation

    SciTech Connect

    Greene, R.H.; Casada, D.A.; Ayers, C.W.

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  17. Low socioeconomic status is associated with adverse events in children and teens on insulin pumps under a universal access program: a population-based cohort study

    PubMed Central

    Shulman, Rayzel; Stukel, Therese A; Miller, Fiona A; Newman, Alice; Daneman, Denis; Wasserman, Jonathan D; Guttmann, Astrid

    2016-01-01

    Objective To describe adverse events in pediatric insulin pump users since universal funding in Ontario and to explore the role of socioeconomic status and 24-hour support. Research design and methods Population-based cohort study of youth (<19 years) with type 1 diabetes (n=3193) under a universal access program in Ontario, Canada, from 2006 to 2013. We linked 2012 survey data from 33 pediatric diabetes centers to health administrative databases. The relationship between patient and center-level characteristics and time to first diabetic ketoacidosis (DKA) admission or death was tested using a Cox proportional hazards model and the rate of diabetes-related emergency department visits and hospitalizations with a Poisson model, both using generalized estimating equations. Results The rate of DKA was 5.28/100 person-years and mortality 0.033/100 person-years. Compared with the least deprived quintile, the risk of DKA or death for those in the most deprived quintile was significantly higher (HR 1.58, 95% CI 1.05 to 2.38) as was the rate of diabetes-related acute care use (RR 1.60, 95% CI 1.27 to 2.00). 24-hour support was not associated with these outcomes. Higher glycated hemoglobin, prior DKA, older age, and higher nursing patient load were associated with a higher risk of DKA or death. Conclusions The safety profile of pump therapy in the context of universal funding is similar to other jurisdictions and unrelated to 24-hour support. Several factors including higher deprivation were associated with an increased risk of adverse events and could be used to inform the design of interventions aimed at preventing poor outcomes in high-risk individuals. PMID:27547416

  18. Submersible sodium pump

    DOEpatents

    Brynsvold, G.V.; Lopez, J.T.; Olich, E.E.; West, C.W.

    1989-11-21

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates. 14 figs.

  19. Submersible sodium pump

    DOEpatents

    Brynsvold, Glen V.; Lopez, John T.; Olich, Eugene E.; West, Calvin W.

    1989-01-01

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates.

  20. Detection of pump degradation

    SciTech Connect

    Casada, D.

    1995-04-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous special vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Pump head and flow rate are also monitored, per code requirements. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition; advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  1. Wind pumping: A handbook

    SciTech Connect

    van Meel, J.; Smulders, P.

    1989-01-01

    The handbook is meant to provide energy and water-supply professionals and economists as well as field officers with an easily accessible source of information on wind pumping. It consolidates information acquired by institutions, professionals, and research centers in an easily extractable form. An overview of the characteristics of the technology is provided. The techniques for sizing of wind pumps and the sizing of alternative small pumps is discussed. Guidelines for financial and economic assessment of wind pumping are given. Particulars on installation, maintenance, and other logistical matters are also given. Several annexes provide supporting details and examples.

  2. Enhanced notification of infusion pump programming errors.

    PubMed

    Evans, R Scott; Carlson, Rick; Johnson, Kyle V; Palmer, Brent K; Lloyd, James F

    2010-01-01

    Hospitalized patients receive countless doses of medications through manually programmed infusion pumps. Many medication errors are the result of programming incorrect pump settings. When used appropriately, smart pumps have the potential to detect some programming errors. However, based on the current use of smart pumps, there are conflicting reports on their ability to prevent patient harm without additional capabilities and interfaces to electronic medical records (EMR). We developed a smart system that is connected to the EMR including medication charting that can detect and alert on potential pump programming errors. Acceptable programming limits of dose rate increases in addition to initial drug doses for 23 high-risk medications are monitored. During 22.5 months in a 24 bed ICU, 970 alerts (4% of 25,040 doses, 1.4 alerts per day) were generated for pump settings programmed outside acceptable limits of which 137 (14%) were found to have prevented potential harm. Monitoring pump programming at the system level rather than the pump provides access to additional patient data in the EMR including previous dosage levels, other concurrent medications and caloric intake, age, gender, vitals and laboratory results.

  3. Liquid-Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, K. A.

    2007-01-01

    Multiple liquid-metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to test prototypical space nuclear system components. Conduction, induction, and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated with incorporation into a reactor system. The thermoelectric pump is recommended for inclusion in the planned system at NASA MSFC based on its relative simplicity, low power supply mass penalty, flight heritage, and the promise of increased pump efficiency over earlier flight pump designs through the use of skutterudite thermoelectric elements.

  4. APPLICATIONS OF LASERS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Laser system based on a commercial microwave oscillator with time compression of a microwave pump pulse

    NASA Astrophysics Data System (ADS)

    Arteev, M. S.; Vaulin, V. A.; Slinko, V. N.; Chumerin, P. Yu; Yushkov, Yu G.

    1992-06-01

    An analysis is made of the possibility of using a commercial microsecond microwave oscillator, supplemented by a device for time compression of microwave pulses, in pumping of industrial lasers with a high efficiency of conversion of the pump source energy into laser radiation. The results are reported of preliminary experiments on the commissioning of an excimer XeCl laser.

  5. High-power PPMgLN-based optical parametric oscillator pumped by a linearly polarized, semi-fiber-coupled acousto-optic Q-switched fiber master oscillator power amplifier.

    PubMed

    Chen, Tao; Jiang, Peipei; Yang, Dingzhong; Hu, Chengzhi; Wu, Bo; Shen, Yonghang

    2013-09-01

    We have experimentally demonstrated a periodically poled magnesium-oxide-doped lithium niobate (PPMgLN)-based, fiber-laser-pumped optical parametric oscillator (OPO) generating idler wavelength of 3.82 μm. The pump fiber laser was constructed with a linearly polarized, semi-fiber-coupled acousto-optic Q-switched fiber oscillator and a polarization-maintaining fiber amplifier with pulse duration of 190 ns at the highest output power. The OPO was specifically configured in single-pass, singly resonant linear cavity structure to avoid the damage risk of the pump fiber laser, which is always a serious issue in the fiber-laser-pumped, double-pass, singly oscillating structured OPOs. Under the highest pump power of 25 W, an idler average output power of 3.27 W with one-hour peak-to-peak instability of 5.2% was obtained. The measured M2 factors were 1.98 and 1.44 for horizontal and vertical axis, respectively. The high power stability and good beam quality demonstrated the suitability of such technology for practical application. PMID:24085093

  6. Particulate problem solutions for rod pumped producing wells

    SciTech Connect

    Williams, S.J.

    1995-12-31

    Sand and other fluid entrained particulates can cause substantial operational problems for rod pumped producing wells. These problems take the form of down-hole pump wear, plunger sticking, and/or catastrophic breakage of pump components. A six year study of 600+ pump investigations shows that problems with particulates account for a substantial number of the total barrel and plunger failures. Many of these failures could have been avoided through the proper application of API and special pump designs as well as certain choices of pump variables. These pump variables and designs will be addressed along with operating parameters. How hard is sand? How large is it? Should plunger and barrel choices take these variables into account? Also, metal plungers must {open_quotes}slip{close_quotes} fluid for proper lubrication. Too much slippage leads to pump inefficiencies. However, down-hole pump efficiencies based on slippage need to be balanced against pump longevity due to proper selection for particulate production. Some time-proven rules of thumb can be applied to make these choices, and an included chart will make plunger slippage calculations simple and straightforward. Scale which sticks to pump surfaces dictates the choice of a different style down-hole pump. A straight-forward modification of an RH style API pump has proved successful in these conditions. Fluid and particulate production with and without attendant gas production requires a different approach to down-hole pump selection. Several successful older pump designs as well as some recently proven new designs will be described. A test program has been completed and actual applications have shown that an API Tubing Pump derivative can pump large volumes of particulate laden fluid without characteristic sticking of the plunger.

  7. An efficient continuous-wave 591 nm light source based on sum-frequency mixing of a diode pumped Nd:GdVO4-Nd:CNGG laser

    NASA Astrophysics Data System (ADS)

    Zhao, Y. D.; Liu, J. H.

    2013-08-01

    We report a laser architecture to obtain continuous-wave (CW) yellow-orange light sources at the 591 nm wavelength. An 808 nm diode pumped a Nd:GdVO4 crystal emitting at 1063 nm. A part of the pump power was then absorbed by the Nd:CNGG crystal. The remaining pump power was used to pump a Nd:CNGG crystal emitting at 1329 nm. Intracavity sum-frequency mixing at 1063 and 1329 nm was then realized in a LiB3O5 (LBO) crystal to reach the yellow-orange radiation. We obtained a CW output power of 494 mW at 591 nm with a pump laser diode emitting 17.8 W at 808 nm.

  8. Demonstration of optical parametric gain generation in the 1 μm regime based on a photonic crystal fiber pumped by a picosecond mode-locked ytterbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Yang, Si-Gang; Wang, Xiao-Jian; Gou, Dou-Dou; Chen, Hong-Wei; Chen, Ming-Hua; Xie, Shi-Zhong

    2014-01-01

    We report the experimental demonstration of the optical parametric gain generation in the 1 μm regime based on a photonic crystal fiber (PCF) with a zero group velocity dispersion (GVD) wavelength of 1062 nm pumped by a homemade tunable picosecond mode-locked ytterbium-doped fiber laser. A broad parametric gain band is obtained by pumping the PCF in the anomalous GVD regime with a relatively low power. Two separated narrow parametric gain bands are observed by pumping the PCF in the normal GVD regime. The peak of the parametric gain profile can be tuned from 927 to 1038 nm and from 1099 to 1228 nm. This widely tunable parametric gain band can be used for a broad band optical parametric amplifier, large span wavelength conversion or a tunable optical parametric oscillator.

  9. Liquid pump for astronaut cooling

    NASA Technical Reports Server (NTRS)

    Carson, M. A.

    1972-01-01

    The Apollo portable life support system water-recirculation pump used for astronaut cooling is described. The problems associated with an early centrifugal pump and how these problems were overcome by the use of a new diaphragm pump are discussed. Performance comparisons of the two pump designs are given. Developmental problems and flight results with the diaphragm pump are discussed.

  10. Well-pump alignment system

    DOEpatents

    Drumheller, Douglas S.

    1998-01-01

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping.

  11. Gastrostomy feeding tube - pump - child

    MedlinePlus

    Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Your child has a gastrostomy tube (G-tube). This is a soft, plastic tube placed into your child's stomach. It delivers nutrition (food) and medicines until your ...

  12. METHOD FOR PUMPING GASES AT LOW VACUUM PRESSURES

    DOEpatents

    Milleron, N.

    1962-06-01

    A method is given for pumping overpressure "pulses" or "bursts" of gases without a significant rise in base pressure within a "gettering-type" vacuum pump having surfaces within the pumping cavity coated with or comprising clean gettering metal, e.g., Mo or Ta. The cavity is first pumped down by any convenient means to an equilibrium base pressure in the range desired, generally below 10/sup -6/ mm Hg. At this pressure, the metal immediately adsorbs overpressures or "bursts" of gases striking same with thermal motion without raising the base pressure significantiy. Desorption takes place at an equilibrium rate which, of course, is dependent upon the equilibrium pressure, and such desorbed gases are continuously removed by diffuaion pump or other pumping, whereby said overpressures or "bursts" of gases are removed without a rise in the equilibrium pressure and/or back diffusion of the gaseous pulse from the pumping cavity. (AEC)

  13. 33. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING ...

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

    33. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING PLAN AND LOCATION OF PROPOSED ADDITIONS, METROPOLITAN WATER AND SEWERAGE BOARD, METROPOLITAN SEWERAGE WORKS, JULY 1908. Aperture card 6417. - Deer Island Pumping Station, Boston, Suffolk County, MA

  14. 32. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING ...

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

    32. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING PLANT AND LOCATION OF PROPOSED ADDITIONS, JULY 1898 SHEET NO. 1. Aperture card 4966-1 - Deer Island Pumping Station, Boston, Suffolk County, MA

  15. Looking south at boiler feedwater pumps (steam turbine pump on ...

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

    Looking south at boiler feedwater pumps (steam turbine pump on left, electric motor pump on right). - Wheeling-Pittsburgh Steel Corporation, Allenport Works, Boiler House, Route 88 on West bank of Monongahela River, Allenport, Washington County, PA

  16. NEUTRONIC REACTOR FUEL PUMP

    DOEpatents

    Cobb, W.G.

    1959-06-01

    A reactor fuel pump is described which offers long life, low susceptibility to radiation damage, and gaseous fission product removal. An inert-gas lubricated bearing supports a journal on one end of the drive shsft. The other end has an impeller and expansion chamber which effect pumping and gas- liquid separation. (T.R.H.)

  17. Pump apparatus including deconsolidator

    SciTech Connect

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  18. Cryogenic Vacuum Pump

    NASA Technical Reports Server (NTRS)

    Zachman, C. A.

    1983-01-01

    System provides high pumping capacity even for noble gases. First stage, removes water and CO2 from input gas. Second stage, removes noble gases except helium and some lighter gases not trapped by first stage. Third stage, traps all remaining gases. All three stages mounted inside liquid-nitrogen Dewar that cools first stage. Pump small enough for general laboratory use.

  19. Water Treatment Technology - Pumps.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on pumps provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pumps in plant and distribution systems, pump…

  20. Micromachined peristaltic pumps

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T. (Inventor)

    1999-01-01

    Micromachined pumps including a channel formed between a first membrane and a substrate or between first and second flexible membranes. A series of electrically conductive strips is applied to a surface of the substrate or one of the membranes. Application of a sequential voltage to the series of strips causes a region of closure to progress down the channel to achieve a pumping action.

  1. A Shocking New Pump

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Hydro Dynamics, Inc. received a technical helping hand from NASA that made their Hydrosonic Pump (HPump) a reality. Marshall engineers resolved a bearing problem in the rotor of the pump and recommended new bearings, housings and mounting hardware as a solution. The resulting HPump is able to heat liquids with greater energy efficiency using shock waves to generate heat.

  2. Magnetic heat pump design

    NASA Astrophysics Data System (ADS)

    Kirol, L. D.; Dacus, M. W.

    1988-03-01

    Heat pumps utilizing the magnetocaloric effect offer a potentially attractive alternative to conventional heat pumps and refrigerators. Many physical configurations of magnetic heat pumps are possible. Major classes include those requiring electrical energy input and those with mechanical energy input. Mechanical energy is used to move magnets, working material, or magnetic shielding. Each type of mechanical magnetic heat pump can be built in a rotary (recuperative) or reciprocal (regenerative) configuration. Machines with electrical energy input utilize modulation of the magnetic field to cause working material to execute the desired thermodynamic cycle, and can also be recuperative or regenerative. Recuperative rotary heat pumps in which working material is moved past stationary magnets is the preferred configuration. Regenerative devices suffer performance degradation from temperature change of regenerator material and mixing and conduction in the regenerator. Field modulated cycles are not practical due to ac losses in superconducting magnets. Development of methods for recuperator fluid pumping is the major challenge in design of rotary recuperative devices. Several pumping options are presented, and the design of a bench scale heat pump described.

  3. Detection of pump degradation

    SciTech Connect

    Casada, D.

    1994-12-31

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous spectral vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition: advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  4. Dielectric elastomer pump for artificial organisms

    NASA Astrophysics Data System (ADS)

    Bowers, Amy E.; Rossiter, Jonathan M.; Walters, Peter J.; Ieropoulos, Ioannis A.

    2011-04-01

    This paper presents a bio-inspired, dielectric elastomer (DE) based tubular pumping unit, developed for eventual use as a component of an artificial digestive tract onboard a microbial fuel cell powered robot (EcoBot). The pump effects fluid displacement by direct actuation of the tube wall as opposed to excitation by an external body. The actuator consists of a DE tube moulded from silicone, held in a negative pressure chamber, which is used for prestraining the tube. The pump is coupled with custom designed polymeric check valves in order to rectify the fluid flow and assess the performance of the unit. The valves exhibited the necessary low opening pressures required for use with the actuator. The tube's actuation characteristics were measured both with and without liquid in the system. Based on these data the optimal operating conditions for the pump are discussed. The pump and valve system has achieved flowrates in excess of 40μl/s. This radially contracting/expanding actuator element is the fundamental component of a peristaltic pump. This 'soft pump' concept is suitable for biomimetic robotic systems, or for the medical or food industries where hard contact with the delivered substrate may be undesirable. Future work will look at connecting multiple tubes in series in order to achieve peristalsis.

  5. Deep well solar pump

    SciTech Connect

    Vanek, J.

    1990-02-06

    This patent describes, in a pump having a source of gas under pressure, and a gas operated pump, a mechanism periodically injecting gas from the source of gas into the gas operated pump. It comprises: a long period pendulum turning towards a first position by gravity, an injection valve connected between the source of gas under pressure and the gas operated pump, a linkage between the pendulum and the injection valve. The linkage opening the injection valve when the pendulum is in the first position, an impulse tube connected between the injection valve and the gas operated pump, a member having a surface adjacent to the first position of the pendulum, and an elastic impulse bladder connected to the impulse tube adjacent to the surface so that inflation of the impulse bladder on the opening of the injection valve forces the impulse bladder against the pendulum urging the pendulum against the force of gravity toward a second position.

  6. Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1996-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  7. Solar-pumped solid-state lasers

    SciTech Connect

    Weksler, M.; Shwartz, J.

    1988-06-01

    Results are presented for direct solar pumping of a ND:YAG rod laser. Stable CW output of more than 60 W was obtained with a slope efficiency exceeding 2 percent. A compound parabolic concentrator, designed to increase the solar radiation coupled into the laser rod, was used in these experiments. The results are consistent with predictions based on a simple solar-pumped laser model, which is also presented. Using this model, it is shown that existing laser materials with broad-band absorption characteristics (e.g., alexandrite and Nd:Cr:GSGG) have a potential for better than 10 percent overall conversion efficiency when solar pumped.

  8. Apparatus for Pumping a Fluid

    NASA Technical Reports Server (NTRS)

    Boeyen, Robert Van; Reeh, Jonathan

    2013-01-01

    A fluid pump has been developed for mechanically pumped fluid loops for spacecraft thermal control. Lynntech's technology utilizes a proprietary electrochemically driven pumping mechanism. Conventional rotodynamic and displacement pumps typically do not meet the stringent power and operational reliability requirements of space applications. Lynntech's developmental pump is a highly efficient solid-state pump with essentially no rotating or moving components (apart from metal bellows).

  9. A finite-element-based perturbation model for the rotordynamic analysis of shrouded pump impellers: Part 1: Model development and applications

    NASA Technical Reports Server (NTRS)

    Baskharone, Erian A.

    1993-01-01

    This study concerns the rotor dynamic characteristics of fluid-encompassed rotors, with special emphasis on shrouded pump impellers. The core of the study is a versatile and categorically new finite-element-based perturbation model, which is based on a rigorous flow analysis and what we have generically termed the 'virtually' deformable finite-element approach. The model is first applied to the case of a smooth annular seal for verification purposes. The rotor excitation components, in this sample problem, give rise to a purely cylindrical, purely conical, and a simultaneous cylindrical/conical rotor whirl around the housing centerline. In all cases, the computed results are compared to existing experimental and analytical data involving the same seal geometry and operating conditions. Next, two labyrinth-seal configurations, which share the same tooth-to-tooth chamber geometry but differ in the total number of chambers, were investigated. The results, in this case, are compared to experimental measurements for both seal configurations. The focus is finally shifted to the shrouded-impeller problem, where the stability effects of the leakage flow in the shroud-to-housing secondary passage are investigated. To this end, the computational model is applied to a typical shrouded-impeller pump stage, fabricated and rotor dynamically tested by Sulzer Bros., and the results compared to those of a simplified 'bulk-flow' analysis and Sulzer Bros.' test data. In addition to assessing the computed rotor dynamic coefficients, the shrouded-impeller study also covers a controversial topic, namely that of the leakage-passage inlet swirl, which was previously cited as the origin of highly unconventional (resonance-like) trends of the fluid-exerted forces. In order to validate this claim, a 'microscopic' study of the fluid/shroud interaction mechanism is conducted, with the focus being on the structure of the perturbed flow field associated with the impeller whirl. The conclusions

  10. Custom Unit Pump Development for the EVA PLSS

    NASA Technical Reports Server (NTRS)

    Schuller, Michael; Kurwitz, Cable; Little, Frank; Oinuma, Ryoji; Larsen, Ben; Goldman, Jeff; Reinis, Filip; Trevino, Luis

    2010-01-01

    This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design and test a pre-flight prototype pump for use in the Extra-vehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump must accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting non-condensable gas without becoming air locked. The chosen pump design consists of a 28 V DC, brushless, seal-less, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES verified that the pump meets the design requirements for range of flow rates, pressure drop, power consumption, working fluid temperature, operating time, gas ingestion, and restart capability under both ambient and vacuum conditions. The pump operated at 40 to 240 lbm/hr flow rate, 35 to 100 oF pump temperature, and 5 to 10 psid pressure rise. Power consumption of the pump controller at the nominal operating point in both ambient and vacuum conditions was 9.5 W, which was less than the 12 W predicted. Gas ingestion capabilities were tested by injecting 100 cc of air into the fluid line; the pump operated normally throughout this test.

  11. Modular pump head design of diffused, metal, and hybrid pump geometry for diode-side-pumped high power Nd:YAG laser.

    PubMed

    Sundar, R; Ranganathan, K; Hedaoo, P; Bindra, K S

    2016-09-20

    In this paper, we present a comparative study on pump heads for a high power diode-side-pumped Nd:YAG laser. The pump head is a modular type, which is in the form of discs, with each disc holding three pump diodes kept at 120° with respect to each other. Unabsorbed pump light from the active medium is reflected by reflectors mounted adjacent to the pump diodes. The performance of a high power pump head made of modular discs mounted with specular or diffused type reflectors was studied. Hybrid pump geometry was also investigated, where the pump head is made up of discs loaded with metal and diffused reflectors, alternately. The discs are loaded around the active medium in such a way that successive discs are rotated by sixty degrees with respect to each other. Fluorescence profiles, thermal lensing, laser output power, and M2 values were studied for pump heads made up of metal, diffused, and hybrid type reflectors. All of the pump heads were studied for three different resonator lengths to maximize the output power with the best beam quality. The experimental results show that the diffused reflector-based geometry in a sixty degree rotated configuration produced the maximum output power and best beam quality in terms of the M2 value. PMID:27661579

  12. Diamagnetic pumping in a rotating convection zone

    NASA Astrophysics Data System (ADS)

    Kitchatinov, L. L.; Nepomnyashchikh, A. A.

    2016-10-01

    Solar dynamo models require some mechanism for magnetic field concentration near the base of the convection zone in order to generate super-kilogauss toroidal fields with sufficiently large (∼ 1024 Mx) magnetic flux. We consider the downward diamagnetic pumping near the base of the convection zone as a possible concentration mechanism and derive the pumping velocities with allowance for the effect of rotation. Transport velocities for poloidal and toroidal fields differ in rotating fluid. The toroidal field is transported downward along the radius only but the pumping velocity for the poloidal field has an equatorward meridional component also. Previous results for cases of slow and rapid rotation are reproduced and the diamagnetic pumping expressions adapted for use in dynamo models are presented.

  13. Mid-infrared rotated image singly resonant twisted rectangle optical parametric oscillator based on HgGa(2)S(4) pumped at 1064 nm.

    PubMed

    Marchev, Georgi; Reza, Manuel; Badikov, Valeriy; Esteban-Martin, Adolfo; Stöppler, Georg; Starikova, Marina; Badikov, Dmitrii; Panyutin, Vladimir; Eichhorn, Marc; Shevyrdyaeva, Galina; Tyazhev, Aleksey; Sheina, Svetlana; Agnesi, Antonio; Fintisova, Anna; Petrov, Valentin

    2014-11-20

    We compare linear, planar ring, and rotated image singly resonant twisted rectangle (RISTRA) type nanosecond optical parametric oscillator cavities using HgGa2S4 nonlinear crystal pumped by 8 ns pulses at 1064 nm from a low beam quality pump source. The input-output characteristics and the output idler beam quality at 6300 nm are compared for two values of the pump beam diameter presenting different cavity Fresnel numbers and magnitudes of the spatial walk-off effect due to birefringence. The RISTRA cavity ensures in all cases a circular output beam profile but is advantageous in terms of beam quality with respect to the planar ring only at a large pump beam diameter. PMID:25607872

  14. Pressure charged airlift pump

    DOEpatents

    Campbell, Gene K.

    1983-01-01

    A pumping system is described for pumping fluids, such as water with entrained mud and small rocks, out of underground cavities such as drilled wells, which can effectively remove fluids down to a level very close to the bottom of the cavity and which can operate solely by compressed air pumped down through the cavity. The system utilizes a subassembly having a pair of parallel conduit sections (44, 46) adapted to be connected onto the bottom of a drill string utilized for drilling the cavity, the drill string also having a pair of coaxially extending conduits. The subassembly includes an upper portion which has means for connection onto the drill string and terminates the first conduit of the drill string in a plenum (55). A compressed air-driven pump (62) is suspended from the upper portion. The pump sucks fluids from the bottom of the cavity and discharges them into the second conduit. Compressed air pumped down through the first conduit (46) to the plenum powers the compressed air-driven pump and aerates the fluid in the second conduit to lift it to the earth's surface.

  15. Deep well pump

    SciTech Connect

    Downen, J.L.; Sutliff, W.N.

    1981-06-16

    A pump barrel open at its lower end is coupled at its upper end by a tubular adapter assembly to the lower end of a pump tubing string. This assembly presents an internal bevelled sealing latching annulus, an axially bored pump head being radially expansively spring latched in a fixed axial sealed relation with the annulus to seal the upper end of the pump barrel from the adapter assembly to form a pump compression chamber surrounding a hollow polish rod extending upwardly from a plunger mounted on the lower end of the polish rod for reciprocation in the pump barrel. The plunger carries tandem travelling valves close beneath its connection with the polish rod. The lower valve opening to receive oil through the barrel and plunger on the down stroke and concurrently delivering such oil into the compression chamber. The upper valve closes on the down stroke and opening on the up stroke during which the lower valve closes to expel oil trapped in the compression chamber upward through the upper valve into the lower end of the hollow polish rod which oil is discharged at the upper end thereof into the pump tubing string through the fitting adapting the polish rod to the lower end of the sucker rod.

  16. Performance of mosquito's pump

    NASA Astrophysics Data System (ADS)

    Kikuchi, Kenji

    2005-11-01

    The flow of human blood in Mosquito's proboscis on Hagen-Poiseuille flow is investigated by using micro PIV system to apply mosquito's sucking system for micro-TAS devises. We want to know how high the power of Mosquito's pump is and how small the resistance in a proboscis is, a structure of Mosquito's sucking pump, and its characteristics as mechanical pump. We made the mosquito suck blood of our arm to obtain the average value, made many slices of a mosquito with 2μm thickness after fixed by wax. We anatomized the mosquito's head and picked up the sucking pump under the microscope to know its volume. Mosquito's pump shows high performance compared with the artificial pumps. The surfaces of proboscis were taken by using SEM, AFM because it is important factor for interaction between flow and its wall. Visualization of the blood flows near the tip of and inside proboscis are taken by micro PIV system to know the flow rate. We estimate the power of pump and the friction drag of proboscis by using these data.

  17. Fuel injection pump

    SciTech Connect

    Iiyama, A.; Nishimura, T.

    1988-12-06

    This patent describes a fuel injection pump comprising: (a) engageable first and second cam members, the first cam member reciprocating axially as the first cam member moves angularly relative to the second cam member when the first and second cam members are in engagement; (b) means for urging the first cam member toward the second cam member to engage the first and second cam members; (c) a plunger connected to the first cam member for reciprocation with the first cam member, the plunger defining at least a part of a pumping chamber, the pumping chamber contracting and expanding as the plunger reciprocates; (d) means for allowing fuel to move into the pumping chamber as the pumping chamber expands in a fuel intake stroke; (e) means for allowing the fuel to move out of the pumping chamber as the pumping chamber contracts in a fuel compression stroke; and (f) means for resisting movement of the plunger in at least part of the fuel compression stroke and relieving resistance to the movement of the plunger in the fuel intake stroke wherein the resisting means comprises a piston slidably mounted on the plunger, a spring urging the piston to seat the piston on a shoulder on the plunger so that the piston reciprocates as the plunger reciprocates, wherein the piston is seated on the shoulder in the fuel compression stroke and separates from the shoulder against the force of the spring in the fuel intake stroke, a second fluid chamber at least partially defined by the piston.

  18. Design optimization of flow channel and performance analysis for a new-type centrifugal blood pump

    NASA Astrophysics Data System (ADS)

    Ji, J. J.; Luo, X. W.; Y Wu, Q.

    2013-12-01

    In this paper, a new-type centrifugal blood pump, whose impeller is suspended inside a pump chamber with hydraulic bearings, is presented. In order to improve the hydraulic performance of the pump, an internal flow simulation is conducted to compare the effects of different geometrical parameters of pump flow passage. Based on the numerical results, the pumps can satisfy the operation parameters and be free of hemolysis. It is noted that for the pump with a column-type supporter at its inlet, the pump head and hydraulic efficiency decreases compared to the pump with a step-type support structure. The performance drop is caused by the disturbed flow upstream impeller inlet. Further, the unfavorable flow features such as reverse flow and low velocity in the pump may increases the possibility of thrombus. It is also confirmed that the casing shape can little influence pump performance. Those results are helpful for design optimization in blood pump development.

  19. spin pumping occurred under nonlinear spin precession

    NASA Astrophysics Data System (ADS)

    Zhou, Hengan; Fan, Xiaolong; Ma, Li; Zhou, Shiming; Xue, Desheng

    Spin pumping occurs when a pure-spin current is injected into a normal metal thin layer by an adjacent ferromagnetic metal layer undergoing ferromagnetic resonance, which can be understood as the inverse effect of spin torque, and gives access to the physics of magnetization dynamics and damping. An interesting question is that whether spin pumping occurring under nonlinear spin dynamics would differ from linear case. It is known that nonlinear spin dynamics differ distinctly from linear response, a variety of amplitude dependent nonlinear effect would present. It has been found that for spin precession angle above a few degrees, nonlinear damping term would present and dominated the dynamic energy/spin-moment dissipation. Since spin pumping are closely related to the damping process, it is interesting to ask whether the nonlinear damping term could be involved in spin pumping process. We studied the spin pumping effect occurring under nonlinear spin precession. A device which is a Pt/YIG microstrip coupled with coplanar waveguide was used. High power excitation resulted in spin precession entering in a nonlinear regime. Foldover resonance lineshape and nonlinear damping have been observed. Based on those nonlinear effects, we determined the values of the precession cone angles, and the maximum cone angle can reach a values as high as 21.5 degrees. We found that even in nonlinear regime, spin pumping is still linear, which means the nonlinear damping and foldover would not affect spin pumping process.

  20. Design of a Bearingless Blood Pump

    NASA Technical Reports Server (NTRS)

    Barletta, Natale; Schoeb, Reto

    1996-01-01

    In the field of open heart surgery, centrifugal blood pumps have major advantages over roller pumps. The main drawbacks to centrifugal pumps are however problems with the bearings and with the sealing of the rotor shaft. In this paper we present a concept for a simple, compact and cost effective solution for a blood pump with a totally magnetically suspended impeller. It is based on the new technology of the 'Bearingless Motor' and is therefore called the 'Bearingless Blood Pump.' A single bearingless slice motor is at the same time a motor and a bearing system and is able to stabilize the six degrees of freedom of the pump impeller in a very simple way. Three degrees of freedom are stabilized actively (the rotation and the radial displacement of the motor slice). The axial and the angular displacement are stabilized passively. The pump itself (without the motor-stator and the control electronics) is built very simply. It consists of two parts only: the impeller with the integrated machine rotor and the housing. So the part which gets in contact with blood and has therefore to be disposable, is cheap. Fabricated in quantities, it will cost less than $10 and will therefore be affordable for the use in a heart-lung-machine.

  1. Simulation and performance analysis of an ammonia-water absorption heat pump based on the generator-absorber heat exchange (GAX) cycle

    SciTech Connect

    Grossman, G.; DeVault, R.C.; Creswick, F.A.

    1995-02-01

    A computer simulation has been conducted to investigate the performance of an absorption heat pump, based on the Generator-Absorber Heat Exchange (GAX) cycle employing ammonia-water as the working fluid pair. The particular feature of this cycle is the ability to recover heat from the absorber and employ it to partially heat the generator, thus improving the COP. In the present study, a detailed simulation has been conducted of one of the preferred configurations for the cycle. A modular computer code for flexible simulation of absorption systems (ABSIM) was employed. Performance parameters, including COP and capacity, were investigated as functions of different operating parameters over a wide range of conditions in both the cooling and heating mode. The effect of the ambient temperature, the rectifier performance, the flowrate in the GAX heat transfer loop and the refrigerant flow control were investigated. COP`s on the order of 1.0 for cooling and 2.0 for heating have been calculated.

  2. Blue diode-pumped solid-state-laser based on ytterbium doped laser crystals operating on the resonance zero-phonon transition

    DOEpatents

    Krupke, William F.; Payne, Stephen A.; Marshall, Christopher D.

    2001-01-01

    The invention provides an efficient, compact means of generating blue laser light at a wavelength near .about.493+/-3 nm, based on the use of a laser diode-pumped Yb-doped laser crystal emitting on its zero phonon line (ZPL) resonance transition at a wavelength near .about.986+/-6 nm, whose fundamental infrared output radiation is harmonically doubled into the blue spectral region. The invention is applied to the excitation of biofluorescent dyes (in the .about.490-496 nm spectral region) utilized in flow cytometry, immunoassay, DNA sequencing, and other biofluorescence instruments. The preferred host crystals have strong ZPL fluorecence (laser) transitions lying in the spectral range from .about.980 to .about.992 nm (so that when frequency-doubled, they produce output radiation in the spectral range from 490 to 496 nm). Alternate preferred Yb doped tungstate crystals, such as Yb:KY(WO.sub.4).sub.2, may be configured to lase on the resonant ZPL transition near 981 nm (in lieu of the normal 1025 nm transition). The laser light is then doubled in the blue at 490.5 nm.

  3. Targeting efflux pumps to overcome antifungal drug resistance.

    PubMed

    Holmes, Ann R; Cardno, Tony S; Strouse, J Jacob; Ivnitski-Steele, Irena; Keniya, Mikhail V; Lackovic, Kurt; Monk, Brian C; Sklar, Larry A; Cannon, Richard D

    2016-08-01

    Resistance to antifungal drugs is an increasingly significant clinical problem. The most common antifungal resistance encountered is efflux pump-mediated resistance of Candida species to azole drugs. One approach to overcome this resistance is to inhibit the pumps and chemosensitize resistant strains to azole drugs. Drug discovery targeting fungal efflux pumps could thus result in the development of azole-enhancing combination therapy. Heterologous expression of fungal efflux pumps in Saccharomyces cerevisiae provides a versatile system for screening for pump inhibitors. Fungal efflux pumps transport a range of xenobiotics including fluorescent compounds. This enables the use of fluorescence-based detection, as well as growth inhibition assays, in screens to discover compounds targeting efflux-mediated antifungal drug resistance. A variety of medium- and high-throughput screens have been used to identify a number of chemical entities that inhibit fungal efflux pumps. PMID:27463566

  4. Pressurized Vessel Slurry Pumping

    SciTech Connect

    Pound, C.R.

    2001-09-17

    This report summarizes testing of an alternate ''pressurized vessel slurry pumping'' apparatus. The principle is similar to rural domestic water systems and ''acid eggs'' used in chemical laboratories in that material is extruded by displacement with compressed air.

  5. Regenerative Hydride Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  6. Keeping Hearts Pumping

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A collaboration between NASA, Dr. Michael DeBakey, Dr. George Noon, and MicroMed Technology, Inc., resulted in a life-saving heart pump for patients awaiting heart transplants. The MicroMed DeBakey VAD functions as a "bridge to heart transplant" by pumping blood throughout the body to keep critically ill patients alive until a donor heart is available. Weighing less than 4 ounces and measuring 1 inch by 3 inches, the pump is approximately one-tenth the size of other currently marketed pulsatile VADs. This makes it less invasive and ideal for smaller adults and children. Because of the pump's small size, less than 5 percent of the patients implanted developed device-related infections. It can operate up to 8 hours on batteries, giving patients the mobility to do normal, everyday activities.The MicroMed DeBakey VAD is a registered trademark of MicroMed Technology, Inc.

  7. Absorption heat pump system

    DOEpatents

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  8. Absorption heat pump system

    DOEpatents

    Grossman, Gershon

    1984-01-01

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  9. GAS METERING PUMP

    DOEpatents

    George, C.M.

    1957-12-31

    A liquid piston gas pump is described, capable of pumping minute amounts of gas in accurately measurable quantities. The pump consists of a flanged cylindrical regulating chamber and a mercury filled bellows. Sealed to the ABSTRACTS regulating chamber is a value and having a gas inlet and outlet, the inlet being connected by a helical channel to the bellows. A gravity check valve is in the gas outlet, so the gas passes through the inlet and the helical channel to the bellows where the pumping action as well as the metering is accomplished by the actuation of the mercury filled bellows. The gas then flows through the check valve and outlet to any associated apparatus.

  10. Direct nuclear pumped laser

    DOEpatents

    Miley, George H.; Wells, William E.; DeYoung, Russell J.

    1978-01-01

    There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

  11. Liquid Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.

    2007-01-01

    Multiple liquid metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to test prototypical space nuclear system components. Conduction, induction, and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated incorporation into a reactor system. The thermoelectric electromagnetic pump is recommended for inclusion in the present system based on favorable quantitative and qualitative measures relative to the other options under consideration.

  12. Basic program analyzes fluid rheology to determine pump rates

    SciTech Connect

    Moftah, K.R. )

    1994-05-09

    The use of statistical methods can improve the selection of a rheological model and the subsequent calculations for critical pump rate and pressure drop for cementing operations. The accompanying interactive Basic computer program allows the user to analyze fluid rheology to help determine the best data for use in predicting cementing pump rates. An accurate critical pump rate and pressure drop can then be calculated based on the correctly calculated rheological parameters. For cementing operations, the important methods of calculating the critical pump rate are the Hedstrom analysis, based on the Bingham plastic rheological model, and the Metzner and Reed analysis, based on the power law rheological model.

  13. Remotely Adjustable Hydraulic Pump

    NASA Technical Reports Server (NTRS)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  14. Hydraulic well pump

    SciTech Connect

    Dollison, W.W.

    1987-09-08

    This patent describes a system for operating a sucker rod string connected with a well pump comprising: a double-acting fluid cylinder having opposing power ends; means for connecting the cylinder with the sucker rod string for raising and lowering the string to operate the pump; hydraulic pump means for supplying pressurized fluid alternately to the cylinder ends including a direction control movable between extend and retract conditions to extend and retract the cylinder; drive means for shifting the direction control; control means for operating the drive means responsive to the extend and retract movements of the cylinder; and means for applying a fluid counterbalancing force into the cylinder for offsetting the combined weights of the sucker rod string. A production fluid column in a well bore above the pump, and movable surface equipment supported on the cylinder include an accumulator connected with the hydraulic pump means and the direction control for supercharging the intake of the pump during the extend movement of the cylinder and for applying an opposing hydraulic force to the cylinder during the retract movement.

  15. Smart'' pump and treat

    SciTech Connect

    Isherwood, W.; Rice, D. Jr.; Ziagos, J. ); Nichols, E. )

    1991-09-01

    Lawrence Livermore National Laboratory (LLNL) is approaching the final phase of the Superfund decision-making process for site restoration and will soon initiate full scale cleanup. Despite some well-publicized failings of the pump and treat approach, we have concluded that intelligent application of this strategy if the best choice for ground water restoration at LLNL. Our proposed approach differs sufficiently from the pump and treat methods implemented at other sites that we call it smart'' pump and treat. Smart pump and treat consists of four distinct, but interrelated, elements: three preremediation strategies and one modification to pump and treat itself. Together, these techniques are an integrated program that utilizes an understanding of crucial aspects of contaminant flow and transport to speed up the remediation of contaminated aquifers. The four elements are: (1) a spatially detailed site characterization, linked with regional hydrogeologic models; (2) directed extraction, where the extraction and recharge locations are controlled by field-determined hydrogeologic parameters; (3) field-validated modeling that the matches the complexity of the collected data; and (4) adaptive pumping, whose pattern varies with time. Together, these techniques minimize the cost and the time to reach regulatory directed cleanup goals and maximize the rate of contaminant removal. 8 refs.

  16. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Benkowski, Robert J. (Inventor); Kiris, Cetin (Inventor); Kwak, Dochan (Inventor); Rosenbaum, Bernard J. (Inventor); Bacak, James W. (Inventor); DeBakey, Michael E. (Inventor)

    1999-01-01

    A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein.

  17. Auxiliary lubrication pump apparatus

    SciTech Connect

    Glesmann, H.C.; Thomas, R.G.

    1987-02-10

    This patent describes an auxiliary lubrication pump apparatus for use with a towing vehicle having an engine switch, a battery, and an interior compartment, and a towed vehicle having an automatic transmission which requires forced lubrication while being towed. The apparatus comprises: (a) a lubrication pump; (b) a transmission to pump hose connected between the automatic transmission and the lubrication pump; (c) a valve having at least one signal output and two inputs: (d) a hose means for connecting an output of the lubrication pump to one of the inputs of the valve; (e) a first outflow hose for connecting the automatic transmission to another input of the valve; (f) a second output hose for connecting the output of the valve to the automatic transmission; (g) pressure sensing means positioned to sense pressure as regards the second outflow hose; and (h) control means responsive to the pressure sensing means and having switch means for providing electricity to the lubrication pump and to provide an alarm whenever the control means detects through the pressure sensing means that inadequate pressure exists.

  18. Satellite Propellant Pump Research

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Veres, Joseph P.; Hah, Chunill; Nerone, Anthony L.; Cunningham, Cameron C.; Kraft, Thomas G.; Tavernelli, Paul F.; Fraser, Bryan

    2005-01-01

    NASA Glenn initiated a satellite propellant pump technology demonstration program. The goal was to demonstrate the technologies for a 60 percent efficient pump at 1 gpm flow rate and 500 psia pressure rise. The pump design and analysis used the in-house developed computer codes named PUMPA and HPUMP3D. The requirements lead to a 4-stage impeller type pump design with a tip diameter of 0.54 inches and a rotational speed of 57,000 rpm. Analyses indicated that flow cavitation was not a problem in the design. Since the flow was incompressible, the stages were identical. Only the 2-stage pump was designed, fabricated, assembled, and tested for demonstration. Water was selected as the surrogate fluid for hydrazine in this program. Complete mechanical design including stress and dynamic analyses were conducted. The pump was driven by an electric motor directly coupled to the impellers. Runs up to 57,000 rpm were conducted, where a pressure rise of 200 psia at a flow rate of 0.8 gpm was measured to validate the design effort.

  19. The Evolution of Ion Pumps.

    ERIC Educational Resources Information Center

    Maloney, Peter C.; Wilson, T. Hastings

    1985-01-01

    Constructs an evolutionary sequence to account for the diversity of ion pumps found today. Explanations include primary ion pumps in bacteria, features and distribution of ATP-driven pumps, preference for cation transport, and proton pump reversal. The integrated evolutionary hypothesis should encourage new experimental approaches. (DH)

  20. Apply reliability centered maintenance to sealless pumps

    SciTech Connect

    Pradhan, S. )

    1993-01-01

    This paper reports on reliability centered maintenance (RCM) which is considered a crucial part of future reliability engineering. RCM determines the maintenance requirements of plants and equipment in their operating context. The RCM method has been applied to the management of critical sealless pumps in fire/toxic risk services, typical of the petrochemical industry. The method provides advantages from a detailed study of any critical engineering system. RCM is a team exercise and fosters team spirit in the plant environment. The maintenance strategy that evolves is based on team decisions and relies on maximizing the inherent reliability built into the equipment. RCM recommends design upgrades where this inherent reliability is being questioned. Sealless pumps of canned motor design are used as main reactor charge pumps in PVC plants. These pumps handle fresh vinyl chloride monomer (VCM), which is both carcinogenic and flammable.

  1. Horizontal pumping system installed at East Texas gas plant

    SciTech Connect

    Lopez, M.; Goodwin, B.

    1998-07-20

    Installation of horizontal, multistage centrifugal pumps in lean-amine service has proven successful and economical at Union Pacific Resources (UPR) East Texas gas plant (ETGP), Carthage, Tex. In the past, UPR had used either vertical can pumps or positive displacement (PD) pumps for amine circulation in gas-treating operations. When the need to replace a PD pump in the No. 4 amine plant arose, UPR solicited bids from both traditional pump suppliers. Additionally, UPR solicited a bid from REDA for its horizontal pumping system (HPS) based on previous success of this type of pump at ETGP for saltwater disposal. The first pump was installed in May 1996 and designed to circulate a maximum of 80 gpm. Since installation of the pump in No. 4 amine-treating unit, UPR has experienced no downtime and realized a significant cost savings on maintenance labor and parts over the previous positive displacement installation. The success of this HPS in amine service has led UPR to invest in five additional HPS pumps for ETGP`s amine service. The paper describes the decision, economics, pumping systems, preventive maintenance, and post installation performance.

  2. The purine efflux pump PbuE in Bacillus subtilis modulates expression of the PurR and G-box (XptR) regulons by adjusting the purine base pool size.

    PubMed

    Nygaard, Per; Saxild, Hans H

    2005-01-01

    In Bacillus subtilis, the expression of genes encoding enzymes and other proteins involved in purine de novo synthesis and salvage is affected by purine bases and phosphoribosylpyrophosphate (PRPP). The transcription of the genes belonging to the PurR regulon is negatively regulated by the PurR protein and PRPP. The expression of the genes belonging to the G-box (XptR) regulon, including the pbuE gene, is negatively regulated by a riboswitch-controlled transcription termination mechanism. The G-box regulon effector molecules are hypoxanthine and guanine. pbuE encodes a purine base efflux pump and is now recognized as belonging to a third purine regulon. The expression of the pbuE gene is positively regulated by a riboswitch that recognizes adenine. Here we show that the expression of pbuE'-lacZ transcriptional fusions are induced by adenine to the highest extent in mutants which do not express a functional PbuE pump. In a mutant defective in the metabolism of adenine, the ade apt mutant, we found a high intracellular level of adenine and constitutive high levels of PbuE. A growth test using a purine auxotroph provided further evidence for the role of PbuE in lowering the intracellular concentration of purine bases, including adenine. Purine analogs also affect the expression of pbuE, which might be of importance for the protection against toxic analogs. In a mutant that overexpresses PbuE, the expression of genes belonging to the PurR regulon was increased. Our findings provide further evidence for important functions of the PbuE protein, such as acting as a pump that lowers the purine base pool and affects the expression of the G-box and PurR regulons, including pbuE itself, and as a pump involved in protection against toxic purine base analogs.

  3. Pulsed Optically Pumped Rb clock

    NASA Astrophysics Data System (ADS)

    Micalizio, S.; Levi, F.; Godone, A.; Calosso, C. E.; François, B.; Boudot, R.; Affolderbach, C.; Kang, S.; Gharavipour, M.; Gruet, F.; Mileti, G.

    2016-06-01

    INRIM demonstrated a Rb vapour cell clock based on pulsed optical pumping (POP) with unprecedented frequency stability performances, both in the short and in the medium-long term period. In the frame of a EMRP project, we are developing a new clock based on the same POP principle but adopting solutions aimed at reducing the noise sources affecting the INRIM clock. At the same time, concerning possible technological applications, particular care are devoted in the project to reduce the size and the weight of the clock, still keeping the excellent stability of the INRIM clock. The paper resumes the main results of this activity.

  4. Thermally Actuated Hydraulic Pumps

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  5. Tokamak pump limiters

    NASA Astrophysics Data System (ADS)

    Conn, Robert W.

    1984-12-01

    Experiments with pump limiters on several operating tokamaks have established them as efficient collectors of particles. The gas pressure rise within the chamber behind the limiters has been as high as 50 mTorr when there is no internal chamber pumping. Observations of the plasma power distribution over the front face of these limiter modules yield estimates for the scale length of radial power decay consistent with predictions of relatively simple theory. Interaction of the in-flowing plasma with recycling neutral gas near the limiter deflector plate is predicted to become important when the effective ionization mean free path is comparable to or less than the neutral atom mean path length within the throat structure of the limiter. Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6 MW of auxiliary neutral beam heating. Experiments have also been performed with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a regime may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased

  6. Well-pump alignment system

    DOEpatents

    Drumheller, D.S.

    1998-10-20

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump are disclosed, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping. 6 figs.

  7. Efficient green continuous-wave lasing of blue-diode-pumped solid-state lasers based on praseodymium-doped LiYF4.

    PubMed

    Hansen, Nils-Owe; Bellancourt, Aude-Reine; Weichmann, Ulrich; Huber, Günter

    2010-07-10

    We report highly efficient laser operation of praseodymium-doped LiYF(4) in the green spectral range. The influence of the crystal length and pump light focusing on the laser performance has been studied. The pump radiation was delivered by InGaN laser diodes. Optimizing the setup for a 2.9 mm long crystal with a doping concentration of 0.5% led to an electric to green laser power conversion efficiency as high as 7.4%. With 500 and 1000 mW of pump light power, output powers of 179 and 358 mW have been reached, respectively. With respect to absorbed power, slope efficiencies of up to approximately 60% have been achieved.

  8. Multilayer impedance pump: a bio-inspired valveless pump with medical applications

    NASA Astrophysics Data System (ADS)

    Loumes, Laurence

    This thesis introduces the concept of multilayer impedance pump, a novel pumping mechanism inspired from the embryonic heart structure.The multilayer impedance pump is a composite two-layer fluid-filled elastic tube featuring a thick, gelatin-like internal layer similar in nature to the embryonic cardiac jelly, and that is used to amplify longitudinal elastic waves. Pumping is based on the impedance pumping mechanism. Elastic waves are generated upon small external periodic compressions of the elastic tube. They propagate along the tube's walls, reflect at the tube's extremities and drive the flow in a preferential direction. This fully coupled fluid-structure interaction problem is solved for the flow and the structure using the finite element method over a relevant range of frequencies of excitation. Results show that the two-layer configuration can be an efficient wave propagation combination, and that it allows the pump to produce significant flow for small excitations. The multilayer impedance pump is a complex system in which flow and structure exhibit a resonant behavior. At resonance, a constructive elastic wave interaction coupled with a most efficient energy transmission between the elastic walls and the fluid is responsible for the maximum exit flow. The pump efficiency reaches its highest at resonance, highlighting furthermore the concept of resonance pumping.Using the proposed multilayer impedance pump model, we are able to bring an additional proof on the impedance nature of the embryonic heart by comparing a peristaltic and an impedance multilayer pump both excited in similar fashion to the one observed in the embryonic heart.The gelatin layer that models the embryonic cardiac jelly occupies most of the tube walls and is essential to the propagation of elastic waves. A comparison between the exact same impedance pump with and without the additional gelatin layer sheds light on the dynamic role of the cardiac jelly in the embryonic heart and on nature

  9. ac electroosmotic pumping induced by noncontact external electrodes.

    PubMed

    Wang, Shau-Chun; Chen, Hsiao-Ping; Chang, Hsueh-Chia

    2007-01-01

    Electroosmotic (EO) pumps based on dc electroosmosis is plagued by bubble generation and other electrochemical reactions at the electrodes at voltages beyond 1 V for electrolytes. These disadvantages limit their throughput and offset their portability advantage over mechanical syringe or pneumatic pumps. ac electroosmotic pumps at high frequency (>100 kHz) circumvent the bubble problem by inducing polarization and slip velocity on embedded electrodes,1 but they require complex electrode designs to produce a net flow. We report a new high-throughput ac EO pump design based on induced-polarization on the entire channel surface instead of just on the electrodes. Like dc EO pumps, our pump electrodes are outside of the load section and form a cm-long pump unit consisting of three circular reservoirs (3 mm in diameter) connected by a 1x1 mm channel. The field-induced polarization can produce an effective Zeta potential exceeding 1 V and an ac slip velocity estimated as 1 mmsec or higher, both one order of magnitude higher than earlier dc and ac pumps, giving rise to a maximum throughput of 1 mulsec. Polarization over the entire channel surface, quadratic scaling with respect to the field and high voltage at high frequency without electrode bubble generation are the reasons why the current pump is superior to earlier dc and ac EO pumps. PMID:19693362

  10. In vivo evaluation of centrifugal blood pump for cardiopulmonary bypass-Spiral Pump.

    PubMed

    da Silva, Cibele; da Silva, Bruno Utiyama; Leme, Juliana; Uebelhart, Beatriz; Dinkhuysen, Jarbas; Biscegli, José F; Andrade, Aron; Zavaglia, Cecília

    2013-11-01

    The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This rotor is supported by two ball bearings, attached to a stainless steel shaft fixed to the housing base. Worm gears provide axial motion to the blood column, and the rotational motion of the conically shaped impeller generates a centrifugal pumping effect, improving pump efficiency without increasing hemolysis. In vitro tests were performed to evaluate the SP's hydrodynamic performance, and in vivo experiments were performed to evaluate hemodynamic impact during usual CPB. A commercially available centrifugal blood pump was used as reference. In vivo experiments were conducted in six male pigs weighing between 60 and 90 kg, placed on CPB for 6 h each. Blood samples were collected just before CPB (T0) and after every hour of CPB (T1-T6) for hemolysis determination and laboratory tests (hematological and biochemical). Values of blood pressure, mean flow, pump rotational speed, and corporeal temperature were recorded. Also, ergonomic conditions were recorded: presence of noise, difficulty in removing air bubbles, trouble in installing the pump in the drive module (console), and difficulties in mounting the CPB circuit. Comparing the laboratory and hemolysis results for the SP with those of the reference pump, we can conclude that there is no significant difference between the two devices. In addition, reports made by medical staff and perfusionists described a close similarity between the two devices. During in vivo experiments, the SP maintained blood flow and pressure at physiological levels, consistent with those applied in cardiac surgery with CPB, without presenting any malfunction. Also, the SP needed lower rotational

  11. Yb-fiber laser pumped high-power, broadly tunable, single-frequency red source based on a singly resonant optical parametric oscillator.

    PubMed

    Shukla, Mukesh Kumar; Maji, Partha Sona; Das, Ritwick

    2016-07-01

    We present an efficient and tunable source generating multi-watt single-frequency red radiation by intra-cavity frequency doubling of the signal in a MgO-doped periodically poled LiNbO3 (MgO:PPLN)-based singly resonant optical parametric oscillator (SRO). By optimally designing the SRO cavity in a six-mirror configuration, we generate ≈276  nm tunable idler radiation in mid-infrared with a maximum power of Pi=2.05  W at a pump power of Pp=14.0  W. The resonant signal is frequency doubled using a 10 mm-long BiB3O6 (BiBO) crystal which resulted in tunability of a red beam from ≈753 to 780 nm band with maximum power Pr≈4.0  W recorded at λr≈756  nm. The deployment of a six-mirror SRO ensures single-frequency generation of red across the entire tuning range by inducing additional losses to Raman modes of LiNbO3 and, thus, inhibiting their oscillation. Using a scanning Fabry-Perot interferometer (FPI), nominal linewidth of the red beam is measured to ≈3  MHz which changes marginally over the entire tuning range. Long-term (over 1 h) peak-to-peak frequency fluctuation of the generated red beam is estimated to be about 3.3 GHz under free-running conditions at Pp=14.0  W. The generated red beam is delivered in a TEM00 mode profile with M2≤1.32 at maximum power in a red beam.

  12. Yb-fiber laser pumped high-power, broadly tunable, single-frequency red source based on a singly resonant optical parametric oscillator.

    PubMed

    Shukla, Mukesh Kumar; Maji, Partha Sona; Das, Ritwick

    2016-07-01

    We present an efficient and tunable source generating multi-watt single-frequency red radiation by intra-cavity frequency doubling of the signal in a MgO-doped periodically poled LiNbO3 (MgO:PPLN)-based singly resonant optical parametric oscillator (SRO). By optimally designing the SRO cavity in a six-mirror configuration, we generate ≈276  nm tunable idler radiation in mid-infrared with a maximum power of Pi=2.05  W at a pump power of Pp=14.0  W. The resonant signal is frequency doubled using a 10 mm-long BiB3O6 (BiBO) crystal which resulted in tunability of a red beam from ≈753 to 780 nm band with maximum power Pr≈4.0  W recorded at λr≈756  nm. The deployment of a six-mirror SRO ensures single-frequency generation of red across the entire tuning range by inducing additional losses to Raman modes of LiNbO3 and, thus, inhibiting their oscillation. Using a scanning Fabry-Perot interferometer (FPI), nominal linewidth of the red beam is measured to ≈3  MHz which changes marginally over the entire tuning range. Long-term (over 1 h) peak-to-peak frequency fluctuation of the generated red beam is estimated to be about 3.3 GHz under free-running conditions at Pp=14.0  W. The generated red beam is delivered in a TEM00 mode profile with M2≤1.32 at maximum power in a red beam. PMID:27367094

  13. A theoretical study of induction eletrohydrodynamic pumping in outer space

    SciTech Connect

    Seyed-Yagoobi, J. )

    1990-11-01

    The challenge for designers of a space station is to meet requirements ofweight, reliability, power, and maintainability. Several new technologies must be developed to insure the success of the space station. Electrohydrodynamic (EHD) pumping may have an impact on the design of novel pumping devices for space stations or other space-related operations. The principal advantage of EHD pumping is that it is non-mechanical; therefore, it has neither moving mechanical parts nor the need for external pressure for operation. Typical applications of EHD pumping include cooling of underground cables, transformers and similar electrical equipment. An EHD pump uses electric fields acting on electric charges embedded in a fluid to move that fluid. One way of setting up the free charges is induction charging, based on establishing an electrical conductivity gradient perpendicular to the desired direction of fluid motion. This gradient perpendicular to the desired direction of fluid motion. This gradient can be established in the presence of a temperature gradient. There are two basic kinds of induction EHD pump: attraction (forward) and repulsion (backward) pumps. In the attraction pump, the pipe is cooled at the wall, giving a negative electric conductivity gradient. In the repulsion pump, the pipe is heated at the wall, causing a positive electric conductivity gradient. In the attraction pump, the fluid is pumped in the same direction as the traveling electric wave. In this mode, the fluid velocity is limited by the speed of the moving electric field (synchronous speed), which depends on frequency and on the spacing of the electrodes (wavelength) along the channel. Unlike the attraction pump, a repulsion pump has no velocity limit. In the repulsion mode, the fluid is pumped in the opposite direction to the traveling electric wave.

  14. 110  W 1678  nm laser based on high-efficiency optical parametric interactions pumped by high-power slab laser.

    PubMed

    Wei, Xingbin; Peng, Yuefeng; Peng, Jue; Luo, Xingwang; Nie, Zan; Zhou, Tangjian; Gao, Jianrong

    2016-04-01

    This Letter presents a high-efficiency optical parametric amplifier pumped by a high-power slab laser with approximate uniform rectangular distribution. By optimizing the overlapping, spectrum matching, and pulse synchronization for the pump and signal lasers, output power of 110.8 W at 1678 nm with corresponding conversion efficiency of 32.3% was achieved in addition to sufficient usage of the effective area in MgO doped periodically poled lithium niobate crystal. It could also provide a designable and tunable wavelength of the amplified laser in a wide infrared region. PMID:27192299

  15. On the possibility of realizing the singlet oxygen generator on the base of optically pumped fullerenes and of fullerene-like nanoparticles

    NASA Astrophysics Data System (ADS)

    Danilov, Oleg B.; Belousova, I. M.; Mak, A. A.; Belousov, V. P.; Grenishin, A. S.; Kiselev, V. I.; Kris'ko, A. V.; Ponomaryev, A. N.; Sosnov, E. N.

    2003-11-01

    We present the experimental results on singlet oxygen generation via interaction of pumping photons (laser or lamp light), fullerenes (or fullerene-like nanoparticles - astralens) and oxygen in solid-state structures, in solutions and in suspensions. It was shown that the singlet oxygen is adsorbed by the solid-state fullerene coating and by powder-like astralen. It was shown that in course of evaporation of the solution (due to the pump action) is observed the singlet oxygen extraction to the gaseous phase, and the lifetime of 1ΔO2 grows significantly.

  16. A two-stage photonic crystal fiber / silicon photonic wire short-wave infrared wavelength converter/amplifier based on a 1064 nm pump source.

    PubMed

    Kuyken, B; Leo, F; Mussot, A; Kudlinski, A; Roelkens, G

    2015-05-18

    We demonstrate a two-stage wavelength converter that uses compact near-infrared sources to amplify and convert short-wave infrared signals. The first stage consists of a photonic crystal fiber wavelength converter pumped by a Q-switched 1064 nm pump source, while the second stage consists of a silicon photonic wire waveguide wavelength converter. The system enables on-chip amplification and conversion of up to 30 dB . We demonstrate amplification in a broad wavelength range around 2344 nm using temporally long pulses (>300ps).

  17. Narrow bandwidth, picosecond, 1064  nm pumped optical parametric generator for the mid-IR based on HgGa₂S₄.

    PubMed

    Piccoli, Riccardo; Pirzio, Federico; Agnesi, Antonio; Badikov, Valeriy; Badikov, Dmitrii; Marchev, Georgi; Panyutin, Vladimir; Petrov, Valentin

    2014-08-15

    We report on optical parametric generation in a mercury thiogallate (HgGa2S4) crystal pumped by 16 ps, 1064 nm pulses at 250 kHz. A broad tuning range extending from 1.19 to 1.47 μm (signal) and from 3.85 to 10 μm (idler) is achieved. Narrow bandwidth, quasi-Fourier limited operation with high beam quality for the signal/idler pulses and >14% pump depletion is obtained by continuous wave seed injection at 1.29 μm.

  18. Overview of the Lucia laser program: toward 100-Joules, nanosecond-pulse, kW averaged power based on ytterbium diode-pumped solid state laser

    NASA Astrophysics Data System (ADS)

    Chanteloup, J.-C.; Yu, H.; Bourdet, G.; Dambrine, C.; Ferre, S.; Fulop, A.; Le Moal, S.; Pichot, A.; Le Touze, G.; Zhao, Z.

    2005-04-01

    We present the current status of the Lucia laser being built at the LULI laboratory, the national civil facility for intense laser matter interaction in France. This diode pumped laser will deliver a 100 Joules, 10 ns, 10 Hz pulse train from Yb:YAG using 4400 power diode laser bars. We first focus on the amplifier stage by describing the reasons for selecting our extraction architecture. Thermal issues and solutions for both laser and pumping heads are then described. Finally, we emphasize more specifically the need for long-lifetime high-laser-damage-threshold coatings and optics.

  19. Credit PSR. Northeast and southwest facades of Sewage Pumping Station ...

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

    Credit PSR. Northeast and southwest facades of Sewage Pumping Station (Building 4330). Building retains its World War II construction materials and character. In the background at the extreme left is Building 4305 (Unicon Portable Hangar) - Edwards Air Force Base, North Base, Sewage Pumping Station, Southwest of E Street, Boron, Kern County, CA

  20. Heat driven pulse pump

    NASA Technical Reports Server (NTRS)

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

    2000-01-01

    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  1. Flow reversal in enzymatic microfluidic pumps

    NASA Astrophysics Data System (ADS)

    Shum, Henry; Ortiz-Rivera, Isamar; Agrawal, Arjun; Sen, Ayusman; Balazs, Anna

    A chemical reaction occurring at an enzyme-covered patch in a closed fluid chamber generates local solute concentration gradients and, hence, fluid density gradients. This has recently been shown to drive fluid flows with speeds of the order of microns per second. We develop and analyze a model that accounts for fluid density changes due to consumption of the reaction substrate and accumulation of products for such a fluid pump based on the enzyme urease. Hydrolysis of urea by urease produces ammonium bicarbonate, which leads to a net increase in solution density. Higher density fluid is expected to sink and spread horizontally away from the pump. Modeling reveals, however, that the local fluid density is not necessarily greatest near the pump and fluid flow can even reverse in direction after some time. The qualitative behavior depends on two dimensionless parameters, the ratio of solutal expansion coefficients and the ratio of diffusion coefficients for the reaction substrate and product. The predicted reversal of pumping direction is experimentally verified and we show that the direction of pumping also depends on the amount of enzyme present on the patch. A better understanding of these pumps will aid in the design of responsive, chemically powered microfluidic flow control.

  2. Pump tank divider plate for sump suction sodium pumps

    DOEpatents

    George, John A.; Nixon, Donald R.

    1977-01-01

    A circular plate extends across the diameter of "sump suction" pump, with a close clearance between the edge of the plate and the wall of the pump tank. The plate is located above the pump impeller, inlet and outlet flow nozzles but below the sodium free surface and effectively divides the pump tank into two separate chambers. On change of pump speed, the close fitting flow restriction plate limits the rate of flow into or out of the upper chamber, thereby minimizing the rate of level change in the tank and permitting time for the pump cover gas pressure to be varied to maintain an essentially constant level.

  3. 20. Station Unwatering Pumps and Sump Pump, view to the ...

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

    20. Station Unwatering Pumps and Sump Pump, view to the north. The station unwatering pumps are the two large units in the center and right foreground of photograph and are marked with the numbers 1 and 2. The sump pump is the smaller unit in left foreground of photograph. These pumps are used for unwatering the draft chests for maintenance. Note the draft tube unwatering valve visible in background between the two unwatering pumps. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  4. Hydrodynamic performance and heat generation by centrifugal pumps.

    PubMed

    Ganushchak, Y; van Marken Lichtenbelt, W; van der Nagel, T; de Jong, D S

    2006-11-01

    of some commercially-available pumps, is the use of the pump outside the allowable operating region. It is potentially dangerous and should, therefore, never be used in clinical settings. (2) Using centrifugal pumps for kinetic-assisted venous return can only be performed safely when the negative pressure at the inlet of the pump is monitored continuously. The maximum allowable negative pressure has to be defined for each type of pump, and must be based on pump performance.

  5. [Insulin pump therapy in children, adolescents and adults].

    PubMed

    Stadler, Marietta; Zlamal-Fortunat, Sandra; Schütz-Fuhrmann, Ingrid; Rami-Merhar, Birgit; Fröhlich-Reiterer, Elke; Hofer, Sabine; Mader, Julia; Resl, Michael; Kautzky-Willer, Alexandra; Weitgasser, Raimund; Prager, Rudolf; Bischof, Martin

    2016-04-01

    This position statement is based on the current evidence available on the safety and benefits of continuous subcutaneous insulin pump therapy (CSII) in diabetes with an emphasis on the effects of CSII on glycemic control, hypoglycaemia rates, occurrence of ketoacidosis, quality of life and the use of insulin pump therapy in pregnancy. The current article represents the recommendations of the Austrian Diabetes Association for the clinical praxis of insulin pump treatment in children, adolescents and adults. PMID:27052245

  6. Fuel injection pump

    SciTech Connect

    Hishinuma, O.; Masuda, A.; Ohmori, T.; Miyaki, M.; Takemoto, E.

    1987-06-09

    This patent describes a fuel injection pump for an internal combustion engine comprising: a housing having a cylindrical inner surface; a shaft having a portion disposed in rotatably sliding engagement with the cylindrical inner surface and having a first axial bore and a second radial bore therein; at least one pumping plunger slidably disposed in the second radial bore to cooperate therewith to define a compression chamber; a pumping plunger is adapted to be moved in the second radial bore to vary the volume of the compression chamber; an injection plunger slidably disposed in the first axial, bore to cooperate in defining the first and second pressure chambers separated from each other by the injection plunger.

  7. Miniature Lightweight Ion Pump

    NASA Technical Reports Server (NTRS)

    Sinha, Mahadeva P.

    2010-01-01

    This design offers a larger surface area for pumping of active gases and reduces the mass of the pump by eliminating the additional vacuum enclosure. There are three main components to this ion pump: the cathode and anode pumping elements assembly, the vacuum enclosure (made completely of titanium and used as the cathode and maintained at ground potential) containing the assembly, and the external magnet. These components are generally put in a noble diode (or differential) configuration of the ion pump technology. In the present state of the art, there are two cathodes, one made of titanium and the other of tantalum. The anodes are made up of an array of stainless steel cylinders positioned between the two cathodes. All the elements of the pump are in a vacuum enclosure. After the reduction of pressure in this enclosure to a few microns, a voltage is applied between the cathode and the anode elements. Electrons generated by the ionization are accelerated toward the anodes that are confined in the anode space by the axial magnetic field. For the generation of the axial field along the anode elements, the magnet is designed in a C-configuration and is fabricated from rare earth magnetic materials (Nd-B-Fe or Sm-Co) possessing high energy product values, and the yoke is fabricated from the high permeability material (Hiperco-50A composed of Fe-Co-V). The electrons in this region collide with the gas molecules and generate their positive ions. These ions are accelerated into the cathode and eject cathode material (Ti). The neutral atoms deposit on the anode surfaces. Because of the chemical activity of Ti, the atoms combine with chemically active gas molecules (e.g. N2, O2, etc.) and remove them. New layers of Ti are continually deposited, and the pumping of active gases is thus accomplished. Pumping of the inert gases is accomplished by their burial several atomic layers deep into the cathode. However, they tend to re-emit if the entrapping lattice atoms are

  8. Fluid pumping apparatus

    DOEpatents

    West, Phillip B.

    2006-01-17

    A method and apparatus suitable for coupling seismic or other downhole sensors to a borehole wall in high temperature and pressure environments. In one embodiment, one or more metal bellows mounted to a sensor module are inflated to clamp the sensor module within the borehole and couple an associated seismic sensor to a borehole wall. Once the sensing operation is complete, the bellows are deflated and the sensor module is unclamped by deflation of the metal bellows. In a further embodiment, a magnetic drive pump in a pump module is used to supply fluid pressure for inflating the metal bellows using borehole fluid or fluid from a reservoir. The pump includes a magnetic drive motor configured with a rotor assembly to be exposed to borehole fluid pressure including a rotatable armature for driving an impeller and an associated coil under control of electronics isolated from borehole pressure.

  9. New class of diode-pumped, mid-IR, broadly-tunable lasers based on TM{sup 2+} lons in T{sub d} coordination: Cr{sup 2+}:ZnX (X=S,Se)

    SciTech Connect

    Krupke, W.F.; Page, R.H.; Schaffers, K.I.; Payne, S.A.; Beach, R.J.; Skidmore, J.A.; Emmanuel, M.A.

    1997-01-01

    A new class of room-temperature, diode-pumped solid state lasers, that are broadly tunable in the mid-infrared spectral region, has been conceptualized and demonstrated. These lasers are based on intra-ion transitions of divalent transition metals placed in substitutional cation sites of tetrahedral symmetry in large bandgap chalcogenide semiconductor crystals. These combinations of laser-ions and host crystals are seen to provide favorable radiative and non-radiative transition processes for the realization of the desired laser performance characteristics. Spectroscopic data for candidate schemes are reviewed and divalent chromium doped zinc chalcogenides are identified as potentially superior laser candidates. Preparation of laser quality Cr{sup 2+}:ZnSe crystals is described and experimental results to date for a diode-pumped laser are given. Remaining laser development issues are discussed briefly.

  10. A High Vacuum High Speed Ion Pump

    DOE R&D Accomplishments Database

    Foster, J. S. Jr.; Lawrence, E. O.; Lofgren, E. J.

    1952-08-27

    A vacuum pump based on the properties of a magnetically collimated electric discharge is described. It has a speed in the range 3000 to 7000 liters a second and a base pressure in the order of 10{sup -6} mm. (auth)

  11. Air-Operated Sump Pump

    NASA Technical Reports Server (NTRS)

    Nolt, Gary D.

    1988-01-01

    Pump removes liquid seepage from small, restricted area and against large pressure head. Developed for moving small amounts of water and oil from sump pit 85 ft (25.91 m) deep. Fits in space only 6 1/2 in. (16.5 cm) in diameter and 18 in. (45.7 cm) long. In discharge part of pumping cycle, air forces liquid out of pump chamber through pipe. During filling part of pumping cycle, water enters pump chamber from sump pit. Float in chamber next to pump chamber controls pressurization through timer and solenoid valve.

  12. Acoustical heat pumping engine

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

  13. Regenerative adsorbent heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  14. Velocity pump reaction turbine

    DOEpatents

    House, P.A.

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  15. Velocity pump reaction turbine

    DOEpatents

    House, Palmer A.

    1984-01-01

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  16. Velocity pump reaction turbine

    DOEpatents

    House, Palmer A.

    1982-01-01

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  17. Fusion reactor pumped laser

    DOEpatents

    Jassby, Daniel L.

    1988-01-01

    A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

  18. Acoustical heat pumping engine

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

  19. High pressure reciprocating pump

    SciTech Connect

    Besic, D.

    1990-05-01

    This patent describes an improvement in a reciprocating pump having a plunger and a pumping chamber. It comprises: the plunger having a bore communicating with an intersection opening and wherein the plunger incudes a central axis; a suction valve and a discharge valve, each having an axis of actuation parallel to a central axis of the plunger; the suction valve comprising a cylindrical core having a central passageway, and the core is slidably received by a seating member and resiliently biased to the seating member.

  20. Measuring axial pump thrust

    DOEpatents

    Suchoza, B.P.; Becse, I.

    1988-11-08

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices. 1 fig.

  1. Measuring axial pump thrust

    DOEpatents

    Suchoza, Bernard P.; Becse, Imre

    1988-01-01

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices.

  2. Double-effect absorption heat pump, phase 3

    NASA Astrophysics Data System (ADS)

    Cook, F. B.; Cremean, S. P.; Jatana, S. C.; Johnson, R. A.; Malcosky, N. D.

    1987-06-01

    The RD&D program has resulted in design, development and testing of a packaged prototype double-effect generator cycle absorption gas heat pump for the residential and small commercial markets. The 3RT heat pump prototype has demonstrated a COPc of 0.82 and a COPh of 1.65 at ARI rating conditions. The heat pump prototype includes a solid state control system with built-in diagnostics. The absorbent/refrigerant solution thermophysical properties were completely characterized. Commercially available materials of construction were identified for all heat pump components. A corrosion inhibitor was identified and tested in both static and dynamic environments. The safety of the heat pump was analyzed by using two analytical approaches. Pioneer Engineering estimated the factory standard cost to produce the 3RT heat pump at $1,700 at a quantity of 50,000 units/year. One United States patent was allowed covering the heat pump technology, and two divisional applications and three Continuation-in-Park Applications were filed with the U.S.P.T.O. Corresponding patent coverage was applied for in Canada, the EEC, Australia, and Japan. Testing of the prototype heat pump is continuing, as are life tests of multiple pump concepts amd long-term dynamic corrosion tests. Continued development and commercialization of gas absorption heat pumps based on the technology are recommended.

  3. Development of a miniature intraventricular axial flow blood pump.

    PubMed

    Yamazaki, K; Umezu, M; Koyanagi, H; Outa, E; Ogino, S; Otake, Y; Shiozaki, H; Fujimoto, T; Tagusari, O; Kitamura, M

    1993-01-01

    A new intraventricular axial flow blood pump has been designed and developed as a totally implantable left ventricular assist device (LVAD). This pump consists of an impeller combined with a guide-vane, a tube housing, and a DC motor. The pump is introduced into the LV cavity through the LV apex, and the outlet cannula is passed antegrade across the aortic valve. Blood is withdrawn from the LV through the inlet ports at the pump base, and discharged to the ascending aorta. Our newly developed axial flow pump system has the following advantages: 1) it is a simple and compact system, 2) minimal blood stasis both in the device and the LV cavity, 3) minimal blood contacting surface of the pump, 4) easy accessibility with a less invasive surgical procedure, and 5) low cost. A pump flow > 5 L/min was obtained against 100 mmHg differential pressure in the mock circulatory system. The pump could produce a passive pulsatile flow effect with a beating heart more efficiently than other non-pulsatile pumps because of minimal pressure drop and inertia along the bypass tract. Anatomic fit studies using dissected hearts of dilated cardiomyopathy (DCM) cadavers showed that this pump could smoothly pass through the aortic valve without any interference with mitral valve function. Recently, a dynamic pressure groove bearing and a miniature lip seal have been developed. The dynamic pressure groove bearing has a simple structure and acts as a pressure resistant sealing mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. 12. Sewage Ejector Pumps, view to the southwest. These pumps ...

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

    12. Sewage Ejector Pumps, view to the southwest. These pumps are connected to sewage treatment tanks. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  5. Portable engine-pump assembly

    SciTech Connect

    Eberhardt, H.A.

    1987-02-17

    This patent describes a portable engine-pump assembly that is compact and light in weight comprising: an internal combustion engine mounted with its crankshaft extending vertically, a centrifugal pump having an impeller mounted for rotation on a pump shaft within a volute chamber, means mounting the pump on and immediately beneath the engine with the pump shaft extending vertically in accurate alignment and concentricity with the engine crankshaft, means coupling the engine crankshaft and the pump shaft together so that the engine crankshaft drives the pump shaft, the pump comprising a pump body defining the volute chamber and providing a pump inlet passage and a pump discharge passage oriented in generally horizontal directions, the pump body defining an inlet chamber providing passages for the flow of liquid from the pump inlet passage into the impeller from both above and below same and including an upper body portion and a lower body portion, and an exhaust system for the engine including an exhaust passage contained in the upper body portion, a muffler having an inlet, and means providing flow communication between the exhaust passage and the inlet of the muffler.

  6. 13. The River Pump House pump room, in this case ...

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

    13. The River Pump House pump room, in this case in the 100-F Area in January 1945. In the 100 Area, the pumps supplied water to the 100 Area and to the export water system that ran to D and F reactors and the 200 areas. D-8248 - B Reactor, Richland, Benton County, WA

  7. Overview of Pump Room, showing pumps at right and power ...

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

    Overview of Pump Room, showing pumps at right and power distribution cabinets for valve motors along north wall at left. View to east - Wellton-Mohawk Irrigation System, Pumping Plant No. 1, Bounded by Gila River & Union Pacific Railroad, Wellton, Yuma County, AZ

  8. 24. Pump Room interiordewatering pump motor on upper level. Note ...

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

    24. Pump Room interior-dewatering pump motor on upper level. Note the removable roof hatch (steel frame) directly above motor. Dewatering pumps motor control center at left - Hunters Point Naval Shipyard, Drydock No. 4, East terminus of Palou Avenue, San Francisco, San Francisco County, CA

  9. 29. WORTHINGTON FIRE PUMP WITH TURBINE HIDDEN BEHIND. PUMP HOUSE ...

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

    29. WORTHINGTON FIRE PUMP WITH TURBINE HIDDEN BEHIND. PUMP HOUSE IS LOCATED AT HEAD OF OLD TRASH GATES. PUMP ENTERS WATER ON EXTERIOR OF WALL IN FAR SIDE OF PHOTO. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  10. 39. THREECYLINDER HYDRAULIC OIL PUMP (MANUFACTURED BY WORTHINGTON: PUMP AND ...

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

    39. THREE-CYLINDER HYDRAULIC OIL PUMP (MANUFACTURED BY WORTHINGTON: PUMP AND MACHINERY COMPANY, HOLYOKE MASSACHUSETTS) IN MACHINERY CHAMBER FOR SLUICE GATE WORKS ON GALLERY 1. NOTE OIL TANK ABOVE PUMP MOTOR. VIEW TO NORTHWEST. - Owyhee Dam, Across Owyhee River, Nyssa, Malheur County, OR

  11. High sensitivity optically pumped quantum magnetometer.

    PubMed

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz(½) over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz(½) in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  12. High Sensitivity Optically Pumped Quantum Magnetometer

    PubMed Central

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz1/2 over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz1/2 in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  13. High sensitivity optically pumped quantum magnetometer.

    PubMed

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz(½) over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz(½) in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz.

  14. Magnetic-flux pump

    NASA Technical Reports Server (NTRS)

    Hildebrandt, A. F.; Elleman, D. D.; Whitmore, F. C. (Inventor)

    1966-01-01

    A magnetic flux pump is described for increasing the intensity of a magnetic field by transferring flux from one location to the magnetic field. The device includes a pair of communicating cavities formed in a block of superconducting material, and a piston for displacing the trapped magnetic flux into the secondary cavity producing a field having an intense flux density.

  15. Pump Flow Analysis

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Ingersoll-Rand Research, Inc.'s use of COSMIC's computer program MERIDL permits designers to evaluate performance and efficiency characteristics to be expected from the pump's impeller. It also provides information that enables a trained hydraulic engineer to make design improvements. Company was able to avoid the cost of developing new software and to improve some product design features.

  16. Well pumping apparatus

    SciTech Connect

    Meyer, E.D.

    1981-12-15

    A pumping apparatus that may be used with a well in which a sucker rod is connected with the well so as to remain in axial alignment with the same during shifting of the well and the sucker rod is supported clear of the well and the structure for operating the same.

  17. Hydraulic well pump

    SciTech Connect

    Dollison, W.W.

    1986-02-25

    This patent describes a system for operating a sucker rod string connected with a well pump. This pump consists of: a double-acting fluid cylinder having opposing power ends; means for connecting the cylinder with the sucker rod string for raising and lowering the string to operate the pump; means for supplying pressurized fluid alternately to the cylinder ends including a direction control movable between extend and retract conditions to extend and retract the cylinder; drive means for shifting the direction control; control means for operating the drive means responsive to the extend and retract movements of the cylinder; including limit valves positioned to simulate the hydraulic cylinder extend and retract stroke end locations, the limit valves being movably mounted for changing the location of each limit valve and the distance between the limit valves for selectively adjusting the length of the strokes of the hydraulic cylinder and the end limit of the extend and retract strokes of the cylinder. A cam operator is for opening and closing each of the limit valves at the end locations and means connecting the cam operator means with the hydraulic cylinder. Cable is reeved over the movable and fixed sheave means and secured along the second end thereof at a fixed location; and means for applying a fluid counterbalancing force into the cylinder for offsetting the combined weights of the sucker rods string, a production fluid column in a well core above the pump, and movable surface equipment supported on the cylinder.

  18. Heat pumps for industry

    NASA Astrophysics Data System (ADS)

    1991-09-01

    Research activities, both in the laboratory and in the field, confirm that heat pumps can improve energy efficiency and productivity for a multitude of process types. By using heat pumps, process industries can save significant amounts of energy and money and successfully control emissions. Those industries with special needs, such as recovering solvents, can meet them more energy efficiently and cost effectively with heat pumps. Through the years, the Office of Industrial Technologies (OIT) has helped industry solve its energy problems by joining in cooperative agreements with companies willing to do the research. The companies involved in these agreements share the costs of the research and benefit directly from the technology developed. OIT then has information from demonstration projects that it can pass on to others within industry. All the projects described in this brochure were joint ventures between DOE and industry participants. OIT will assist in accelerating the use of heat pumps in the industrial marketplace by continuing to work with industry on research and demonstration projects and to transfer research results and project performance information to the rest of industry. Successfully transferring this technology could conserve as much as 1.5 quads of energy annually at a savings of more than $4 billion at today's prices.

  19. Linear induction pump

    DOEpatents

    Meisner, John W.; Moore, Robert M.; Bienvenue, Louis L.

    1985-03-19

    Electromagnetic linear induction pump for liquid metal which includes a unitary pump duct. The duct comprises two substantially flat parallel spaced-apart wall members, one being located above the other and two parallel opposing side members interconnecting the wall members. Located within the duct are a plurality of web members interconnecting the wall members and extending parallel to the side members whereby the wall members, side members and web members define a plurality of fluid passageways, each of the fluid passageways having substantially the same cross-sectional flow area. Attached to an outer surface of each side member is an electrically conductive end bar for the passage of an induced current therethrough. A multi-phase, electrical stator is located adjacent each of the wall members. The duct, stators, and end bars are enclosed in a housing which is provided with an inlet and outlet in fluid communication with opposite ends of the fluid passageways in the pump duct. In accordance with a preferred embodiment, the inlet and outlet includes a transition means which provides for a transition from a round cross-sectional flow path to a substantially rectangular cross-sectional flow path defined by the pump duct.

  20. An Improved Archimedes Pump

    NASA Astrophysics Data System (ADS)

    Akoglu, Resat

    2002-12-01

    In this note we propose a slightly improved version of the Archimedes pump which was advertised as a toy model in The Physics Teacher. It consists of a hose wound densely around a tube (or pipe made of metallic or plastic material) which can be rotated mechanically (a hand driven one is the most primitive case as shown in the Picture 1) or electrically.

  1. Explosively pumped laser light

    DOEpatents

    Piltch, Martin S.; Michelotti, Roy A.

    1991-01-01

    A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

  2. Progressive cavity pump

    SciTech Connect

    Mueller, J.W.

    1989-04-04

    A progressive cavity pump is described, comprising: a first housing portion defining an inlet; a second housing portion attachable to the first housing portion and defining an outlet; a substantially elastomeric stator comprising an outer portion removably attached to the first and second housing portions, having a first end and a second end spaced from the first end, an inner portion defining a pumping chamber and spaced an annular end portion interconnecting the first ends of the outer and inner portions; a rotor disposed in the inner portion of the stator and extending through the pumping chamber for pumping fluid from the inlet to the outlet in response to rotation of the rotor; and an elongated member disposed in the housing portions and generally annularly between the inner and outer portions of the stator and longitudinally between the annular end portion of the stator and a portion of the second housing portion, the member being removable from the housing portions and separable from the stator.

  3. Downhold hydraulic actuated pump

    SciTech Connect

    Roeder, G.K.

    1987-05-12

    This patent describes a downhole pump of the type having a main housing within which there is formed an engine chamber and a production chamber. A piston is reciprocatingly received within the engine chamber, a plunger reciprocatingly received within the production chamber, a connecting rod by which the piston and plunger are connected together; the combination with the main housing, piston, plunger.

  4. Downhole hydraulic actuated pump

    SciTech Connect

    Roeder, G.K.

    1988-09-06

    This patent describes a downhole hydraulically actuated pump assembly of the type having a main housing within which an engine and pump is enclosed; a connecting rod, an engine piston, a pump plunger, means by which the engine and connecting rod reciprocate the pump plunger and thereby produces fluid; the main housing has a lower end having a formation fluid inlet; and upper end having a power fluid inlet; and, a produced fluid outlet; the plunger divides one marginal end of the housing into upper and lower production chambers; the lower end of the connecting rod is hollow and extends through the plunger into fluid communication with the formation fluid inlet to provide a source of formation fluid for the upper and lower production chambers; a traveling value assembly contained within the plunger and arranged to transfer formation fluid from the hollow rod, through the plunger, and into the upper and lower production chambers, respectively, as the plunger upstrokes and downstrokes; produced fluid valve means by which fluid flows from the upper and lower production chambers and through the produced fluid outlet.

  5. Piezohydraulic Pump Development

    NASA Technical Reports Server (NTRS)

    Lynch, Christopher S.

    2005-01-01

    Reciprocating piston piezohydraulic pumps were developed originally under the Smart Wing Phase II program (Lynch) and later under the CHAP program (CSA, Kinetic Ceramics). These pumps focused on 10 cm scale stack actuators operating below resonance and, more recently, at resonance. A survey of commercially available linear actuators indicates that obtaining power density and specific power greater than electromagnetic linear actuators requires driving the stacks at frequencies greater than 1 KHz at high fields. In the case of 10 cm scale actuators the power supply signal conditioning becomes large and heavy and the soft PZT stack actuators generate a lot of heat due to internal losses. Reciprocation frequencies can be increased and material losses significantly decreased through use of millimeter scale single crystal stack actuators. We are presently targeting the design of pumps that utilize stacks at the 1-10 mm length scale and run at reciprocating frequencies of 20kHz or greater. This offers significant advantages over current approaches including eliminating audible noise and significantly increasing the power density and specific power of the system (including electronics). The pump currently under development will comprise an LC resonant drive of a resonant crystal and head mass operating against a resonant fluid column. Each of these resonant systems are high Q and together should produce a single high Q second order system.

  6. Shrouded inducer pump

    DOEpatents

    Meng, Sen Y.

    1989-01-01

    An improvement in a pump including a shrouded inducer, the improvement comprising first and second sealing means 32,36 which cooperate with a first vortex cell 38 and a series of secondary vortex cells 40 to remove any tangential velocity components from the recirculation flow.

  7. RSES heat pump technician certification

    SciTech Connect

    Zeiner, J.

    1996-06-01

    In 1987 the National Heat Pump certification test was developed by the Refrigeration Service Engineers Society (RSES), and in 1994, the program was more specifically named Heat Pump Service Technician Certification. This report describes the benefits of certification.

  8. Fuel Pumping System And Method

    DOEpatents

    Shafer, Scott F.; Wang, Lifeng

    2005-12-13

    A fuel pumping system that includes a pump drive is provided. A first pumping element is operatively connected to the pump drive and is operable to generate a first flow of pressurized fuel. A second pumping element is operatively connected to the pump drive and is operable to generate a second flow of pressurized fuel. A first solenoid is operatively connected to the first pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the first flow of pressurized fuel. A second solenoid is operatively connected to the second pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the second flow of pressurized fuel.

  9. Fuel pumping system and method

    DOEpatents

    Shafer, Scott F.; Wang, Lifeng ,

    2006-12-19

    A fuel pumping system that includes a pump drive is provided. A first pumping element is operatively connected to the pump drive and is operable to generate a first flow of pressurized fuel. A second pumping element is operatively connected to the pump drive and is operable to generate a second flow of pressurized fuel. A first solenoid is operatively connected to the first pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the first flow of pressurized fuel. A second solenoid is operatively connected to the second pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the second flow of pressurized fuel.

  10. Assessment of the value of microgravity to estimate the principal directions of the anisotropic transmissivity of aquifers from pumping tests: A study using a Hough transform based automatic algorithm

    NASA Astrophysics Data System (ADS)

    Fernández-Álvarez, José-Paulino; González-Quirós, Andrés; Rubio-Melendi, David

    2016-11-01

    Estimation of the hydraulic parameters of an aquifer is usually performed via interpretation of pumping tests. This invasive method requires drilling both pumping and observation wells. As the process is expensive, only a single pumping well and one or two observation wells or piezometers are generally drilled, at most. The interpretation is done assuming aquifer isotropy and homogeneity. However, in many aquifers, horizontal anisotropy in hydraulic conductivity greatly affects the flow regime. Its disregard may lead to important misinterpretations, especially for environmental impact assessments. This paper studies the capabilities of gravity for the identification and determination of the principal directions of anisotropy. This has been automatized using a methodology based on the Hough Transform. The results show how a microgravity survey could be an adequate and relatively cheap monitoring tool for the identification of anisotropy. This is valuable information that can be used in the decision making process for performing or discarding additional studies. Even more, the presented methodology can be extended to other studies in which contour maps are used to identify directionality in any process or property.

  11. Oil well pumping apparatus

    SciTech Connect

    Whatley, D. L.; Chaviers, W. M.

    1985-07-23

    The present system and apparatus for pumping an oil well damps out the stretch and over travel in sucker rod over travel particularly when the rod string approaches its point of reversal of direction either up or down. This is accomplished by decelerating the rate of travel of the rod string and at its end of travel pausing for a time period sufficient to allow rod string oscillations to damp out prior to reversal of rod string direction which due to the long length of the rod string, its weight and the weight of the trapped oil avoids breaking the rod string and the time loss occasioned thereby in both loss of well production and costly replacement of equipment and the time loss resulting therefrom. The present invention also achieves substantial recovery of hi-viscosity oil not recoverable at present by standard recovery procedures. This is accomplished with a sensor positioned to be actuated by the ram of the hydraulic drive. When the sensor is actuated, it energizes a time delay relay which holds the sucker rod string in the upper most raised position allowing the suction to be maintained on the bottom hole pump with the standing valve open. This allows the hi-viscus oil to enter the bottom hole pump barrel. When the time delay relay is released, the sucker rod string starts its downward movement closing the bottom hole standing valve. This traps the hi-viscus oil in the pump barrel which is then displaced by the downward-movement of the plunger in the bottom hole pump.

  12. Absorption heat pumps

    NASA Astrophysics Data System (ADS)

    Huhtinen, M.; Heikkilae, M.; Andersson, R.

    1987-03-01

    The aim of the study was to analyze the technical and economic feasibility of absorption heat pumps in Finland. The work was done as a case study: the technical and economic analyses have been carried out for six different cases, where in each the suitable size and type of the heat pump plant and the auxiliary components and connections were specified. The study also detailed the costs concerning the procurement, installation and test runs of the machinery, as well as the savings in energy costs incurred by the introduction of the plant. Conclusions were drawn of the economic viability of the applications studied. The following cases were analyzed: heat recovery from flue gases and productin of district heat in plants using peat, natural gas, and municipal wastes as a fuel. Heat recovery in the pulp and paper industry for the upgrading of pressure of secondary steam and for the heating of white liquor and combustion and drying the air. Heat recovery in a peat-fulled heat and power plant from flue gases that have been used for the drying of peat. According to the study, the absorption heat pump suits best to the production of district heat, when the heat source is the primary energy is steam produced by the boiler. Included in the flue as condensing is the purification of flue gases. Accordingly, benefit is gained on two levels in thick applications. In heat and power plants the use of absorption heat pumps is less economical, due to the fact that the steam used by the pump reduces the production of electricity, which is rated clearly higher than heat.

  13. Shoring pumping station excavation

    SciTech Connect

    Glover, J.B.; Reardon, D.J. )

    1991-11-01

    The city of San Mateo, Calif., operates three 12- to 50-year old wastewater pumping stations on a 24-m (80-ft) wide lot located in a residential area near San Francisco Bay. Because the aging stations have difficulty pumping peak 2.19-m{sup 3}/s (50-mgd) wet-weather flows and have structural and maintenance problems, a new 2.62-m{sup 3}/s (60-mgd) station was proposed - the Dale Avenue Pumping Station - to replace the existing ones. To prevent potential damage to adjacent homes, the new station was originally conceived as a circular caisson type; however, a geotechnical investigation recommended against this type of structure because the stiff soils could make sinking the structure difficult. This prompted an investigation of possible shoring methods for the proposed structure. Several shoring systems were investigated, including steel sheeting, soldier beams and lagging, tieback systems, open excavation, and others; however, each had disadvantages that prevented its use. Because these conventional techniques were unacceptable, attention was turned to using deep soil mixing (DSM) to create a diaphragm wall around the area to be excavated before constructing the pumping station. Although this method has been used extensively in Japan since 1983, the Dale Avenue Pumping Station would be the technology's first US application. The technology's anticipated advantages were its impermeability, its fast and efficient installation that did not require tiebacks under existing homes, its adaptability to subsurface conditions ranging from soft ground to stiff clay to gravels, and its lack of pile-driving requirements that would cause high vibration levels during installation.

  14. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  15. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    1999-01-01

    Methods and apparatus are provided for a blood pump bearing system within a pump housing to support long-term high-speed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the shaft to support high speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  16. Prediction of pump cavitation performance

    NASA Technical Reports Server (NTRS)

    Moore, R. D.

    1974-01-01

    A method for predicting pump cavitation performance with various liquids, liquid temperatures, and rotative speeds is presented. Use of the method requires that two sets of test data be available for the pump of interest. Good agreement between predicted and experimental results of cavitation performance was obtained for several pumps operated in liquids which exhibit a wide range of properties. Two cavitation parameters which qualitatively evaluate pump cavitation performance are also presented.

  17. Spin current and inverse spin Hall effect in ferromagnetic metals probed by Y{sub 3}Fe{sub 5}O{sub 12}-based spin pumping

    SciTech Connect

    Wang, Hailong; Du, Chunhui; Chris Hammel, P. Yang, Fengyuan

    2014-05-19

    Using ferromagnetic (FM) resonance spin pumping, we observe injection of spin currents from Y{sub 3}Fe{sub 5}O{sub 12} (YIG) films to FM metals, including Ni{sub 81}Fe{sub 19} (Py), Fe, Co, and Ni, and detection of spin currents by inverse spin Hall effect (ISHE) in the FM metals. We obtain a high effective spin mixing conductance of 6.3 × 10{sup 18} m{sup −2} in a YIG/Cu/Py trilayer and a spin Hall angle of 0.020 for Py. The spin pumping signals in Fe, Co, and Ni confirm the mechanism of ISHE in FMs is the inverse process of the anomalous Hall effect.

  18. Natural Circulation in the Blanket Heat Removal System During a Loss-of-Pumping Accident (LOFA) Based on Initial Conceptual Design

    SciTech Connect

    Hamm, L.L.

    1998-10-07

    A transient natural convection model of the APT blanket primary heat removal (HR) system was developed to demonstrate that the blanket could be cooled for a sufficient period of time for long term cooling to be established following a loss-of-flow accident (LOFA). The particular case of interest in this report is a complete loss-of-pumping accident. For the accident scenario in which pumps are lost in both the target and blanket HR systems, natural convection provides effective cooling of the blanket for approximately 68 hours, and, if only the blanket HR systems are involved, natural convection is effective for approximately 210 hours. The heat sink for both of these accident scenarios is the assumed stagnant fluid and metal on the secondary sides of the heat exchangers.

  19. 5. Station Unwatering Pumps and Sump Pump for Units 1 ...

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

    5. Station Unwatering Pumps and Sump Pump for Units 1 and 2, view to the west. The unwatering pumps are the two larger items toward the right side of the photograph (one in foreground and one in background. The smaller item toward the left of the photograph is the sump pump. These pumps are used for draining water from the draft chest for maintenance. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  20. Guide to Geothermal Heat Pumps

    SciTech Connect

    2011-02-01

    Geothermal heat pumps, also known as ground source heat pumps, geoexchange, water-source, earth-coupled, and earth energy heat pumps, take advantage of this resource and represent one of the most efficient and durable options on the market to heat and cool your home.

  1. A novel osmotic pump-based controlled delivery system consisting of pH-modulated solid dispersion for poorly soluble drug flurbiprofen: in vitro and in vivo evaluation.

    PubMed

    Li, Shujuan; Wang, Xiaoyu; Wang, Yingying; Zhao, Qianqian; Zhang, Lina; Yang, Xinggang; Liu, Dandan; Pan, Weisan

    2015-01-01

    In this study, a novel controlled release osmotic pump capsule consisting of pH-modulated solid dispersion for poorly soluble drug flurbiprofen (FP) was developed to improve the solubility and oral bioavailability of FP and to minimize the fluctuation of plasma concentration. The pH-modulated solid dispersion containing FP, Kollidon® 12 PF and Na2CO3 at a weight ratio of 1/4.5/0.02 was prepared using the solvent evaporation method. The osmotic pump capsule was assembled by semi-permeable capsule shell of cellulose acetate (CA) prepared by the perfusion method. Then, the solid dispersion, penetration enhancer, and suspending agents were tableted and filled into the capsule. Central composite design-response surface methodology was used to evaluate the influence of factors on the responses. A second-order polynomial model and a multiple linear model were fitted to correlation coefficient of drug release profile and ultimate cumulative release in 12 h, respectively. The actual response values were in good accordance with the predicted ones. The optimized formulation showed a complete drug delivery and zero-order release rate. Beagle dogs were used to be conducted in the pharmacokinetic study. The in vivo study indicated that the relative bioavailability of the novel osmotic pump system was 133.99% compared with the commercial preparation. The novel controlled delivery system with combination of pH-modulated solid dispersion and osmotic pump system is not only a promising strategy to improve the solubility and oral bioavailability of poorly soluble ionizable drugs but also an effective way to reduce dosing frequency and minimize the plasma fluctuation.

  2. Rotating magnetic poles used to pump mercury

    NASA Technical Reports Server (NTRS)

    Ebihara, B. T.; Lowdermilk, W. H.; Vary, A.

    1966-01-01

    Rotating magnetic pump with redesigned pump cell is used for pumping mercury. The modified pump has better electrical continuity, more efficient heat removal, and good wetting characteristics in the mercury flow channel.

  3. Advanced high-temperature electromagnetic pump

    NASA Technical Reports Server (NTRS)

    Gahan, J. W.; Powell, A. H.

    1972-01-01

    Three phase helical, electromagnetic induction pump for use as boiler feed pump in potassium Rankine-cycle power system is described. Techniques for fabricating components of pump are discussed. Specifications of pump are analyzed.

  4. A regenerative elastocaloric heat pump

    NASA Astrophysics Data System (ADS)

    Tušek, Jaka; Engelbrecht, Kurt; Eriksen, Dan; Dall’Olio, Stefano; Tušek, Janez; Pryds, Nini

    2016-10-01

    A large fraction of global energy use is for refrigeration and air-conditioning, which could be decarbonized if efficient renewable energy technologies could be found. Vapour-compression technology remains the most widely used system to move heat up the temperature scale after more than 100 years; however, caloric-based technologies (those using the magnetocaloric, electrocaloric, barocaloric or elastocaloric effect) have recently shown a significant potential as alternatives to replace this technology due to high efficiency and the use of green solid-state refrigerants. Here, we report a regenerative elastocaloric heat pump that exhibits a temperature span of 15.3 K on the water side with a corresponding specific heating power up to 800 W kg‑1 and maximum COP (coefficient-of-performance) values of up to 7. The efficiency and specific heating power of this device exceeds those of other devices based on caloric effects. These results open up the possibility of using the elastocaloric effect in various cooling and heat-pumping applications.

  5. Quantum mechanical features of optically pumped CW FIR lasers

    NASA Technical Reports Server (NTRS)

    Seligson, D.; Leite, J. R. R.; Sanchez, A.; Feld, M. S.; Ducloy, M.

    1977-01-01

    Quantum mechanical predictions for the gain of an optically pumped CW FIR laser are presented for cases in which one or both of the pump and FIR transitions are pressure or Doppler broadened. The results are compared to those based on the rate equation model. Some of the quantum mechanical predictions are verified in CH3OH.

  6. Generic Safety Requirements for Developing Safe Insulin Pump Software

    PubMed Central

    Zhang, Yi; Jetley, Raoul; Jones, Paul L; Ray, Arnab

    2011-01-01

    Background The authors previously introduced a highly abstract generic insulin infusion pump (GIIP) model that identified common features and hazards shared by most insulin pumps on the market. The aim of this article is to extend our previous work on the GIIP model by articulating safety requirements that address the identified GIIP hazards. These safety requirements can be validated by manufacturers, and may ultimately serve as a safety reference for insulin pump software. Together, these two publications can serve as a basis for discussing insulin pump safety in the diabetes community. Methods In our previous work, we established a generic insulin pump architecture that abstracts functions common to many insulin pumps currently on the market and near-future pump designs. We then carried out a preliminary hazard analysis based on this architecture that included consultations with many domain experts. Further consultation with domain experts resulted in the safety requirements used in the modeling work presented in this article. Results Generic safety requirements for the GIIP model are presented, as appropriate, in parameterized format to accommodate clinical practices or specific insulin pump criteria important to safe device performance. Conclusions We believe that there is considerable value in having the diabetes, academic, and manufacturing communities consider and discuss these generic safety requirements. We hope that the communities will extend and revise them, make them more representative and comprehensive, experiment with them, and use them as a means for assessing the safety of insulin pump software designs. One potential use of these requirements is to integrate them into model-based engineering (MBE) software development methods. We believe, based on our experiences, that implementing safety requirements using MBE methods holds promise in reducing design/implementation flaws in insulin pump development and evolutionary processes, therefore improving

  7. SHINE Vacuum Pump Test Verification

    SciTech Connect

    Morgan, Gregg A; Peters, Brent

    2013-09-30

    Normetex pumps used world-wide for tritium service are no longer available. DOE and other researchers worldwide have spent significant funds characterizing this pump. Identification of alternate pumps is required for performance and compatibility with tritium gas. Many of the pumps that could be used to meet the functional performance requirements (e.g. pressure and flow conditions) of the Normetex pump have features that include the use of polymers or oils and greases that are not directly compatible with tritium service. This study assembles a test system to determine the flow characteristics for candidate alternate pumps. These tests are critical to the movement of tritium through the SHINE Tritium Purification System (TPS). The purpose of the pump testing is two-fold: (1) obtain baseline vacuum pump characteristics for an alternate (i.e. ''Normetex replacement'') pump intended for use in tritium service; and (2) verify that low pressure hydrogen gas can be transported over distances up to 300 feet by the candidate pumps. Flow rates and nominal system pressures have been identified for the SHINE Mo-99 production process Tritium Purification System (TPS). To minimize the line sizes for the transfer of low pressure tritium from the Neutron Driver Accelerator System (NDAS) to the primary processing systems in the TPS, a ''booster'' pump has been located near the accelerator in the design. A series of pump tests were performed at various configurations using hydrogen gas (no tritium) to ensure that this concept is practical and maintains adequate flow rates and required pressures. This report summarizes the results of the tests that have been performed using various pump configurations. The current design of the Tritium Purification System requires the ''booster'' pump to discharge to or to be backed by another vacuum pump. Since Normetex pumps are no longer manufactured, a commercially available Edwards scroll pump will be used to back the booster pump. In this

  8. Cold Climates Heat Pump Design Optimization

    SciTech Connect

    Abdelaziz, Omar; Shen, Bo

    2012-01-01

    Heat pumps provide an efficient heating method; however they suffer from sever capacity and performance degradation at low ambient conditions. This has deterred market penetration in cold climates. There is a continuing effort to find an efficient air source cold climate heat pump that maintains acceptable capacity and performance at low ambient conditions. Systematic optimization techniques provide a reliable approach for the design of such systems. This paper presents a step-by-step approach for the design optimization of cold climate heat pumps. We first start by describing the optimization problem: objective function, constraints, and design space. Then we illustrate how to perform this design optimization using an open source publically available optimization toolbox. The response of the heat pump design was evaluated using a validated component based vapor compression model. This model was treated as a black box model within the optimization framework. Optimum designs for different system configurations are presented. These optimum results were further analyzed to understand the performance tradeoff and selection criteria. The paper ends with a discussion on the use of systematic optimization for the cold climate heat pump design.

  9. An Experimental Evaluation of Oil Pumping Rings

    NASA Technical Reports Server (NTRS)

    Eusepi, M. W.; Walowit, J.; Cohen, M.

    1981-01-01

    The design and construction of a reciprocating test vehicle to be used in evaluating hydrodynamic oil pumping rings are discussed. In addition, experimental test data are presented for three pumping ring designs that were constructed from Tin-Based Babbitt (SAE 11), Bearing Bronze (SAE 660), and Mechanical Carbon Graphite (Union Carbide Grade CNF-J). Data of pumped flow rate versus delivered pressure, as well as friction loss, are reported for the following conditions: frequencies of 10, 35 and 45 Hz; strokes of 25.4 mm (1.00 in.), 38.1 mm (1.50 in.) and 50.8 mm (2.00 in.) oil inlet temperature of 49 degrees (120 degrees); and pumping ring close-in pressures of 10.3 MPa (1500 lb/square inch. A 20W40 automotive oil was used for all tests. The maximum delivered pressure was 11 MPa (1600 lb/square inch. An analysis of hydrodynamic oil pumping rings was performed and the results of the analysis were compared to measured test data.

  10. Bearing for liquid metal pump

    DOEpatents

    Dickinson, Robert J.; Wasko, John; Pennell, William E.

    1984-01-01

    A liquid metal pump bearing support comprises a series of tangentially oriented spokes that connect the bearing cylinder to the pump internals structure. The spokes may be arranged in a plurality of planes extending from the bearing cylinder to the pump internals with the spokes in one plane being arranged alternately with those in the next plane. The bearing support structure provides the pump with sufficient lateral support for the bearing structure together with the capability of accommodating differential thermal expansion without adversely affecting pump performance.

  11. Advancements in flowing diode pumped alkali lasers

    NASA Astrophysics Data System (ADS)

    Pitz, Greg A.; Stalnaker, Donald M.; Guild, Eric M.; Oliker, Benjamin Q.; Moran, Paul J.; Townsend, Steven W.; Hostutler, David A.

    2016-03-01

    Multiple variants of the Diode Pumped Alkali Laser (DPAL) have recently been demonstrated at the Air Force Research Laboratory (AFRL). Highlights of this ongoing research effort include: a) a 571W rubidium (Rb) based Master Oscillator Power Amplifier (MOPA) with a gain (2α) of 0.48 cm-1, b) a rubidium-cesium (Cs) Multi-Alkali Multi-Line (MAML) laser that simultaneously lases at both 795 nm and 895 nm, and c) a 1.5 kW resonantly pumped potassium (K) DPAL with a slope efficiency of 50%. The common factor among these experiments is the use of a flowing alkali test bed.

  12. Effective absorption in cladding-pumped fibers

    NASA Astrophysics Data System (ADS)

    Zervas, Michalis N.; Marshall, Andy; Kim, Jaesun

    2011-02-01

    We investigate experimentally and theoretically the wavelength dependence of the pump absorption along Yb3+-doped fibers, for cladding-pumped single as well as coupled multimode (GTWaveTM) fibers. We show that significant spectral absorption distortions occur along the length with the 976nm absorption peak affected the most. We have developed a novel theoretical approach, based on coupled mode theory, to explain the observed effects. We have also investigated the mode mixing requirements in order to improve the absorption spectral distribution along the increase the overall absorption efficiency and discuss the implications on fiber laser performance.

  13. 21 CFR 880.5725 - Infusion pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Infusion pump. 880.5725 Section 880.5725 Food and... Infusion pump. (a) Identification. An infusion pump is a device used in a health care facility to pump fluids into a patient in a controlled manner. The device may use a piston pump, a roller pump, or...

  14. 21 CFR 880.5725 - Infusion pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Infusion pump. 880.5725 Section 880.5725 Food and... Infusion pump. (a) Identification. An infusion pump is a device used in a health care facility to pump fluids into a patient in a controlled manner. The device may use a piston pump, a roller pump, or...

  15. 21 CFR 880.5725 - Infusion pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Infusion pump. 880.5725 Section 880.5725 Food and... Infusion pump. (a) Identification. An infusion pump is a device used in a health care facility to pump fluids into a patient in a controlled manner. The device may use a piston pump, a roller pump, or...

  16. Rod pumping and proppant flowback at the Lost Hills Field

    SciTech Connect

    Roberts, I.G.

    1995-12-31

    Proppant flowback from hydraulically fractured wells can lead to sand wear on the pump barrel and plunger and increased pulling costs on rod pumped wells. Two approaches for lengthening run times of the pumps were tried. One approach was to install pumps that will allow production of a sand laden fluid. Pressure actuated plunger (PAP) pumps were field tested and showed an average increase of 81.6% in run time. These split ring wiper pumps clean the barrel of sand prior to the passing of the plunger. The other approach was to keep the sand and from entering the pumps. When down hole filters were utilized, run life of the pumps with the filters increases 135%. Well pulling cost savings of $11.91 per well-day and $9.24 per well-day are documented for the PAP pumps and filters, respectively. Application guidelines based on the sand loading rate and gross liquid production of the wells are presented, as well as some operational experiences.

  17. Numerical modeling of hemodynamics with pulsatile impeller pump support.

    PubMed

    Shi, Yubing; Lawford, Patricia V; Hose, D Rodney

    2010-08-01

    There is significant interest in the development and application of variable speed impeller-pump type ventricular assist devices designed to generate pulsatile blood flow. However, no study has so far been carried out to investigate the systemic cardiovascular response to various aspects of pump motion. In this article, a numerical model is constructed for the simulation of the cardiovascular response in the heart failure condition under representative cases of pulsatile impeller pump support. The native cardiovascular model is based on a previously validated model, and the impeller pump is modeled by directly fitting the pressure-flow curves that describe the pump characteristics. The model developed is applied to study circulatory dynamics under different degrees of phase shift and pulsation ratio in the pump motion profile. The characteristic variables are discussed as criteria for the evaluation of system response for comparison of the pulsatile flows. Simulation results show that a constant pump speed is the most efficient work mode for the rotary pump, and with the application of either a phase shift of 75% and a pulsation ratio of 0.5, or a phase shift of 42% and a pulsation ratio of 0.55, it is possible to generate arterial pulse pressure with the maximal magnitude of about 28 mmHg. However, this is achieved at the cost of reduced cardiac output and pump efficiency.

  18. Topological charge pump by surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Yi, Zheng; Shi-Ping, Feng; Shi-Jie, Yang

    2016-06-01

    Quantized electron pumping by the surface acoustic wave across barriers created by a sequence of split metal gates is interpreted from the viewpoint of topology. The surface acoustic wave serves as a one-dimensional periodical potential whose energy spectrum possesses the Bloch band structure. The time-dependent phase plays the role of an adiabatic parameter of the Hamiltonian which induces a geometrical phase. The pumping currents are related to the Chern numbers of the filled bands below the Fermi energy. Based on this understanding, we predict a novel effect of quantized but non-monotonous current plateaus simultaneously pumped by two homodromous surface acoustic waves. Project supported by the National Natural Science Foundation of China (Grant No. 11374036) and the National Basic Research Program of China (Grant No. 2012CB821403).

  19. Optically-electrically pumped THz source

    NASA Astrophysics Data System (ADS)

    Haji-Saeed, Bahareh; Khoury, Jed; Buchwald, Walter; Woods, Charles; Wentzell, Sandra; Krejca, Brian; Kierstead, John

    2010-08-01

    In this paper, we propose a design for a widely tunable solid-state optically and electrically pumped THz source based on the Smith-Purcell free-electron laser. Our design consists of a thin dielectric layer sandwiched between an upper corrugated structure and a lower layer of thin metal, semiconductor, or high electron mobility material. The lower layer is for current streaming, which replaces the electron beam in the Smith-Purcell free-electron laser design. The upper layer consists of two micro-gratings for optical pumping, and a nano-grating to couple with electrical pumping in the lower layer. The optically generated surface plasmon waves from the upper layer and the electrically induced surface plasmon waves from the lower layer are then coupled. Emission enhancement occurs when the plasmonic waves in both layers are resonantly coupled.

  20. Thermoelectric pump performance analysis computer code

    NASA Technical Reports Server (NTRS)

    Johnson, J. L.

    1973-01-01

    A computer program is presented that was used to analyze and design dual-throat electromagnetic dc conduction pumps for the 5-kwe ZrH reactor thermoelectric system. In addition to a listing of the code and corresponding identification of symbols, the bases for this analytical model are provided.