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Sample records for receives strong criticism

  1. Criticality classification of waste receiving and processing module 2A

    SciTech Connect

    Boothe, G.F.

    1994-10-01

    The purpose of this document is to evaluate the criticality potential of the Waste Receiving and Processing Module 2A (WRAP 2A) and to demonstrate that the facility is an exempt facility, under the provisions of the Nuclear Criticality Safety Manual. The WRAP 2A maximum potential transuranic (TRU) contents of feedstreams and product inventories are discussed. Total plant fissionable materials are estimated and compared with the fissionable material exempt quantity. The WRAP 2A operations and processes are also described, relative to the potential for concentrating or accumulating fissionable material within the facility.

  2. Quantum-criticality-induced strong Kerr nonlinearities in optomechanical systems

    PubMed Central

    Lü, Xin-You; Zhang, Wei-Min; Ashhab, Sahel; Wu, Ying; Nori, Franco

    2013-01-01

    We investigate a hybrid electro-optomechanical system that allows us to realize controllable strong Kerr nonlinearities even in the weak-coupling regime. We show that when the controllable electromechanical subsystem is close to its quantum critical point, strong photon-photon interactions can be generated by adjusting the intensity (or frequency) of the microwave driving field. Nonlinear optical phenomena, such as the appearance of the photon blockade and the generation of nonclassical states (e.g., Schrödinger cat states), are demonstrated in the weak-coupling regime, making the observation of strong Kerr nonlinearities feasible with currently available optomechanical technology. PMID:24126279

  3. Refined critical balance in strong Alfvénic turbulence

    NASA Astrophysics Data System (ADS)

    Mallet, A.; Schekochihin, A. A.; Chandran, B. D. G.

    2015-04-01

    We present numerical evidence that in strong Alfvénic turbulence, the critical balance principle - equality of the non-linear decorrelation and linear propagation times - is scale invariant, in the sense that the probability distribution of the ratio of these times is independent of scale. This result only holds if the local alignment of the Elsasser fields is taken into account in calculating the non-linear time. At any given scale, the degree of alignment is found to increase with fluctuation amplitude, supporting the idea that the cause of alignment is mutual dynamical shearing of Elsasser fields. The scale-invariance of critical balance (while all other quantities of interest are strongly intermittent, i.e. have scale-dependent distributions) suggests that it is the most robust of the scaling principles used to describe Alfvénic turbulence. The quality afforded by situ fluctuation measurements in the solar wind allows for direct verification of this fundamental principle.

  4. Superconductivity in Strong Magnetic Field (Greater Than Upper Critical Field)

    SciTech Connect

    Tessema, G.X.; Gamble, B.K.; Skove, M.J.; Lacerda, A.H.; Mielke, C.H.

    1998-08-22

    The National High Magnetic Field Laboratory, funded by the National Science Foundation and other US federal Agencies, has in recent years built a wide range of magnetic fields, DC 25 to 35 Tesla, short pulse 50 - 60 Tesla, and quasi-continuous 60 Tesla. Future plans are to push the frontiers to 45 Tesla DC and 70 to 100 Tesla pulse. This user facility, is open for national and international users, and creates an excellent tool for materials research (metals, semiconductors, superconductors, biological systems ..., etc). Here we present results of a systematic study of the upper critical field of a novel superconducting material which is considered a promising candidate for the search for superconductivity beyond H{sub c2} as proposed by several new theories. These theories predict that superconductors with low carrier density can reenter the superconducting phase beyond the conventional upper critical field H{sub c2}. This negates the conventional thinking that superconductivity and magnetic fields are antagonistic.

  5. Receiver Function Analysis of Strong-motion Stations in Kaohsiung-Pingtung area, Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, Che-Min; Wen, Kuo-Liang; Kuo, Chun-Hsiang; Huang, Jyun-Yan

    2016-04-01

    The Kaohsiung City and Pingtung County are located in southern Taiwan and bounded on the west side by several active faults. The shallow velocity structure of thick alluvium basin in this area should be delineated to understand the seismic site effect of strong ground motion. Receiver Function (RF) is a conventional technique for studying the structure of the crust and upper mantle beneath the seismometer. But, the RF analysis of high-frequency acceleration seismograms is also proved to be feasible for estimating shallow structures recently. This study applied the RF technique on the Strong-motion records of almost one-hundred TSMIP stations in Kaohsiung-Pingtung area to estimate the shallow shear-wave velocity structures. The averaged RFs of all stations exhibit the obvious variation because of the different geologies and site conditions. After the forward modeling of RFs based on the Genetic Algorithms (GA) searching, the shallow shear-wave velocity structures beneath all the strong-motion stations in the Kaohsiung-Pingtung area were estimated to delineate the iso-depth contour maps of the main formation interfaces and a preliminary shallow 3D velocity model.

  6. Receivers

    NASA Astrophysics Data System (ADS)

    Donnelly, H.

    1983-07-01

    Before discussing Deep Space Network receivers, a brief description of the functions of receivers and how they interface with other elements of the Network is presented. Different types of receivers are used in the Network for various purposes. The principal receiver type is used for telemetry and tracking. This receiver provides the capability, with other elements of the Network, to track the space probe utilizing Doppler and range measurements, and to receive telemetry, including both scientific data from the onboard experiments and engineering data pertaining to the health of the probe. Another type of receiver is used for radio science applications. This receiver measures phase perturbations on the carrier signal to obtain information on the composition of solar and planetary atmospheres and interplanetary space. A third type of receiver utilizes very long baseline interferometry (VLBI) techniques for both radio science and spacecraft navigation data. Only the telemetry receiver is described in detail in this document. The integration of the Receiver-Exciter subsystem with other portions of the Deep Space Network is described.

  7. Receivers

    NASA Technical Reports Server (NTRS)

    Donnelly, H.

    1983-01-01

    Before discussing Deep Space Network receivers, a brief description of the functions of receivers and how they interface with other elements of the Network is presented. Different types of receivers are used in the Network for various purposes. The principal receiver type is used for telemetry and tracking. This receiver provides the capability, with other elements of the Network, to track the space probe utilizing Doppler and range measurements, and to receive telemetry, including both scientific data from the onboard experiments and engineering data pertaining to the health of the probe. Another type of receiver is used for radio science applications. This receiver measures phase perturbations on the carrier signal to obtain information on the composition of solar and planetary atmospheres and interplanetary space. A third type of receiver utilizes very long baseline interferometry (VLBI) techniques for both radio science and spacecraft navigation data. Only the telemetry receiver is described in detail in this document. The integration of the Receiver-Exciter subsystem with other portions of the Deep Space Network is described.

  8. Flucytosine Pharmacokinetics in a Critically Ill Patient Receiving Continuous Renal Replacement Therapy

    PubMed Central

    Kunka, Megan E.; Cady, Elizabeth A.; Woo, Heejung C.; Thompson Bastin, Melissa L.

    2015-01-01

    Purpose. A case report evaluating flucytosine dosing in a critically ill patient receiving continuous renal replacement therapy. Summary. This case report outlines an 81-year-old male who was receiving continuous venovenous hemofiltration (CVVH) for acute renal failure and was being treated with flucytosine for the treatment of disseminated Cryptococcus neoformans infection. Due to patient specific factors, flucytosine was empirically dose adjusted approximately 50% lower than intermittent hemodialysis (iHD) recommendations and approximately 33% lower than CRRT recommendations. Peak and trough levels were obtained, which were supratherapeutic, and pharmacokinetic parameters were calculated. The patient experienced thrombocytopenia, likely due to elevated flucytosine levels, and flucytosine was ultimately discontinued. Conclusion. Despite conservative flucytosine dosing for a patient receiving CVVH, peak and trough serum flucytosine levels were supratherapeutic (120 μg/mL at 2 hours and 81 μg/mL at 11.5 hours), which increased drug-related adverse effects. The results indicate that this conservative dosing regimen utilizing the patient's actual body weight was too aggressive. This case report provides insight into flucytosine dosing in CVVH, a topic that has not been investigated previously. Further pharmacokinetic studies of flucytosine dosing in critically ill patients receiving CVVH are needed in order to optimize pharmacokinetic and pharmacodynamic parameters while avoiding toxic flucytosine exposure. PMID:26246919

  9. Disordered bosons in one dimension: from weak- to strong-randomness criticality.

    PubMed

    Hrahsheh, Fawaz; Vojta, Thomas

    2012-12-28

    We investigate the superfluid-insulator quantum phase transition of one-dimensional bosons with off-diagonal disorder by means of large-scale Monte Carlo simulations. For weak disorder, we find the transition to be in the same universality class as the superfluid-Mott insulator transition of the clean system. The nature of the transition changes for stronger disorder. Beyond a critical disorder strength, we find nonuniversal, disorder-dependent critical behavior. We compare our results to recent perturbative and strong-disorder renormalization group predictions. We also discuss experimental implications as well as extensions of our results to other systems. PMID:23368577

  10. Critical point in the QCD phase diagram for extremely strong background magnetic fields

    NASA Astrophysics Data System (ADS)

    Endrödi, Gergely

    2015-07-01

    Lattice simulations have demonstrated that a background (electro)magnetic field reduces the chiral/deconfinement transition temperature of quantum chromodynamics for eB < 1 GeV2. On the level of observables, this reduction manifests itself in an enhancement of the Polyakov loop and in a suppression of the light quark condensates (inverse magnetic catalysis) in the transition region. In this paper, we report on lattice simulations of 1 + 1 + 1-flavor QCD at an unprecedentedly high value of the magnetic field eB = 3 .25 GeV2. Based on the behavior of various observables, it is shown that even at this extremely strong field, inverse magnetic catalysis prevails and the transition, albeit becoming sharper, remains an analytic crossover. In addition, we develop an algorithm to directly simulate the asymptotically strong magnetic field limit of QCD. We find strong evidence for a first-order deconfinement phase transition in this limiting theory, implying the presence of a critical point in the QCD phase diagram. Based on the available lattice data, we estimate the location of the critical point.

  11. Fluconazole pharmacokinetics in a morbidly obese, critically ill patient receiving continuous venovenous hemofiltration.

    PubMed

    Lopez, Natasha D; Phillips, Kristy M

    2014-09-01

    Current fluconazole dosing strategies can be described using either standardized doses (800 or 400 mg) or as weight-based dosing recommendations (12 mg/kg loading dose followed by 6 mg/kg maintenance dose). The ideal method of fluconazole dosing is still unclear for certain patient populations, such as those receiving renal replacement therapy or the morbidly obese. We describe a 48-year-old man with a body mass index of 84 kg/m(2) who was receiving continuous venovenous hemofiltration (CVVH) and was treated with fluconazole by using a weight-based dose determined by lean body weight, infused at a rate of 200 mg/hour. Blood samples were collected at hour 0 (i.e., ~24 hrs after the loading dose was administered) and at 3.5, 6.8, and 11.3 hours after the start of the 600-mg maintenance dose, infused over 3 hours. Pharmacokinetic parameters calculated were maximum serum concentration 9.64 mg/L, minimum serum concentration 5.98 mg/L, area under the serum concentration-time curve from 0-24 hours (AUC0-24 ) 184.75 mg/L•hour, elimination rate constant 0.0199 hour(-1) , elimination half-life 34.8 hours, and total body clearance 3.25 L/hour. Our data, when combined with previously published literature, do not support using a linear dose-to-AUC approximation to estimate drug dosing needs in the critically ill patient population receiving CVVH. In addition, our results suggest that morbidly obese patients are able to achieve pharmacodynamic goals defined as an AUC:MIC ratio higher than 25 by using a lean body weight for fluconazole dosing calculations. PMID:25074285

  12. Critical experiments on an enriched uranium solution system containing periodically distributed strong thermal neutron absorbers

    SciTech Connect

    Rothe, R.E.

    1996-09-30

    A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution`s concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the `Poisoned Tube Tank` because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service.

  13. Existence of Global Strong Solutions in Critical Spaces for Barotropic Viscous Fluids

    NASA Astrophysics Data System (ADS)

    Haspot, Boris

    2011-11-01

    This paper is dedicated to the study of viscous compressible barotropic fluids in dimension N ≧ 2. We address the question of the global existence of strong solutions for initial data close to a constant state having critical Besov regularity. First, this article shows the recent results of C harve and Danchin (Arch Ration Mech Anal 198(1):233-271, 2010) and Chen et al. (Commun Pure Appl Math 63:1173-1224, 2010) with a new proof. Our result relies on a new a priori estimate for the velocity that we derive via the intermediary of the effective velocity, which allows us to cancel out the coupling between the density and the velocity as in Haspot (Well-posedness in critical spaces for barotropic viscous fluids, 2009). Second, we improve the results of Charve and Danchin (2010) and Chen et al. (2010) by adding as in Charve and Danchin (2010) some regularity on the initial data in low frequencies. In this case we obtain global strong solutions for a class of large initial data which rely on the results of Hoff (Arch Rational Mech Anal 139:303-354, 1997), Hoff (Commun Pure Appl Math 55(11):1365-1407, 2002), and Hoff (J Math Fluid Mech 7(3):315-338, 2005) and those of Charve and Danchin (2010) and Chen et al. (2010). We conclude by generalizing these results for general viscosity coefficients.

  14. Identifying early-warning signals of critical transitions with strong noise by dynamical network markers

    PubMed Central

    Liu, Rui; Chen, Pei; Aihara, Kazuyuki; Chen, Luonan

    2015-01-01

    Identifying early-warning signals of a critical transition for a complex system is difficult, especially when the target system is constantly perturbed by big noise, which makes the traditional methods fail due to the strong fluctuations of the observed data. In this work, we show that the critical transition is not traditional state-transition but probability distribution-transition when the noise is not sufficiently small, which, however, is a ubiquitous case in real systems. We present a model-free computational method to detect the warning signals before such transitions. The key idea behind is a strategy: “making big noise smaller” by a distribution-embedding scheme, which transforms the data from the observed state-variables with big noise to their distribution-variables with small noise, and thus makes the traditional criteria effective because of the significantly reduced fluctuations. Specifically, increasing the dimension of the observed data by moment expansion that changes the system from state-dynamics to probability distribution-dynamics, we derive new data in a higher-dimensional space but with much smaller noise. Then, we develop a criterion based on the dynamical network marker (DNM) to signal the impending critical transition using the transformed higher-dimensional data. We also demonstrate the effectiveness of our method in biological, ecological and financial systems. PMID:26647650

  15. Critical and strong-coupling phases in one- and two-bath spin-boson models.

    PubMed

    Guo, Cheng; Weichselbaum, Andreas; von Delft, Jan; Vojta, Matthias

    2012-04-20

    For phase transitions in dissipative quantum impurity models, the existence of a quantum-to-classical correspondence has been discussed extensively. We introduce a variational matrix product state approach involving an optimized boson basis, rendering possible high-accuracy numerical studies across the entire phase diagram. For the sub-Ohmic spin-boson model with a power-law bath spectrum ∝ω(s), we confirm classical mean-field behavior for s<1/2, correcting earlier numerical renormalization-group results. We also provide the first results for an XY-symmetric model of a spin coupled to two competing bosonic baths, where we find a rich phase diagram, including both critical and strong-coupling phases for s<1, different from that of classical spin chains. This illustrates that symmetries are decisive for whether or not a quantum-to-classical correspondence exists. PMID:22680701

  16. Use of subjective global assessment and clinical outcomes in critically ill geriatric patients receiving nutrition support.

    PubMed

    Atalay, Betül Gülsen; Yagmur, Cahide; Nursal, Tarik Zafer; Atalay, Hakan; Noyan, Turgut

    2008-01-01

    The objective of this study is to examine the prevalence of malnutrition and evaluate the nutrition status and clinical outcome in hospitalized patients aged 65 years and older receiving enteral-parenteral nutrition. This retrospective study was carried out at Başkent University Hospital, Adana, Turkey. A total of 119 patients older than 65 years were recruited. Patients were classified into 3 groups: protein-energy malnutrition (PEM), moderate PEM, and well nourished according to subjective global assessment (SGA) at admission. All patients were fed by enteral or parenteral route. Acute physiological and chronic health evaluation (APACHE-2) and simplified acute physiology (SAPS 2) scores were recorded in patients followed in the intensive care unit (ICU). Nutrition status was assessed with biochemical (serum albumin, serum prealbumin) parameters. These results were compared with mortality rate and length of hospital stay (LOS). The subjects' mean (+/-SD) age was 73.1 +/- 5.4 years. Using SGA, 5.9% (n = 7) of the patients were classified as severely PEM, 27.7% (n = 33) were classified as moderately PEM, and 66.4% (n = 79) were classified as well nourished. Some 73.1% (n = 87) of the patients were followed in the ICU. Among all patients, 42.9% (n = 51) were fed by a combined enteral-parenteral route, 31.1% (n = 37) by an enteral route, 18.5% (n = 22) by a parenteral route, and 7.6% (n = 9) by an oral route. The average length of stay for the patients was 18.9 +/- 13.7 days. The mortality rate was 44.5% (n = 53). The mortality rate was 43% (n = 34) in well-nourished patients (n = 79), 48.5% (n = 16) in moderately PEM patients (n = 33), and 42.9% (n = 3) in severely PEM patients (n = 7) (P = .86). The authors observed no difference between well-nourished and malnourished patients with regard to the serum protein values on admission, LOS, and mortality rate. In this study, malnutrition as defined by SGA did not influence the mortality rate of critically ill geriatric

  17. Entropy excess in strongly correlated Fermi systems near a quantum critical point

    SciTech Connect

    Clark, J.W.; Zverev, M.V.; Khodel, V.A.

    2012-12-15

    A system of interacting, identical fermions described by standard Landau Fermi-liquid (FL) theory can experience a rearrangement of its Fermi surface if the correlations grow sufficiently strong, as occurs at a quantum critical point where the effective mass diverges. As yet, this phenomenon defies full understanding, but salient aspects of the non-Fermi-liquid (NFL) behavior observed beyond the quantum critical point are still accessible within the general framework of the Landau quasiparticle picture. Self-consistent solutions of the coupled Landau equations for the quasiparticle momentum distribution n(p) and quasiparticle energy spectrum {epsilon}(p) are shown to exist in two distinct classes, depending on coupling strength and on whether the quasiparticle interaction is regular or singular at zero momentum transfer. One class of solutions maintains the idempotency condition n{sup 2}(p)=n(p) of standard FL theory at zero temperature T while adding pockets to the Fermi surface. The other solutions are characterized by a swelling of the Fermi surface and a flattening of the spectrum {epsilon}(p) over a range of momenta in which the quasiparticle occupancies lie between 0 and 1 even at T=0. The latter, non-idempotent solution is revealed by analysis of a Poincare mapping associated with the fundamental Landau equation connecting n(p) and {epsilon}(p) and validated by solution of a variational condition that yields the symmetry-preserving ground state. Significantly, this extraordinary solution carries the burden of a large temperature-dependent excess entropy down to very low temperatures, threatening violation of the Nernst Theorem. It is argued that certain low-temperature phase transitions, notably those involving Cooper-pair formation, offer effective mechanisms for shedding the entropy excess. Available measurements in heavy-fermion compounds provide concrete support for such a scenario. - Highlights: Black-Right-Pointing-Pointer Extension of Landau

  18. Entropy excess in strongly correlated Fermi systems near a quantum critical point

    NASA Astrophysics Data System (ADS)

    Clark, J. W.; Zverev, M. V.; Khodel, V. A.

    2012-12-01

    A system of interacting, identical fermions described by standard Landau Fermi-liquid (FL) theory can experience a rearrangement of its Fermi surface if the correlations grow sufficiently strong, as occurs at a quantum critical point where the effective mass diverges. As yet, this phenomenon defies full understanding, but salient aspects of the non-Fermi-liquid (NFL) behavior observed beyond the quantum critical point are still accessible within the general framework of the Landau quasiparticle picture. Self-consistent solutions of the coupled Landau equations for the quasiparticle momentum distribution n(p) and quasiparticle energy spectrum ɛ(p) are shown to exist in two distinct classes, depending on coupling strength and on whether the quasiparticle interaction is regular or singular at zero momentum transfer. One class of solutions maintains the idempotency condition n2(p)=n(p) of standard FL theory at zero temperature T while adding pockets to the Fermi surface. The other solutions are characterized by a swelling of the Fermi surface and a flattening of the spectrum ɛ(p) over a range of momenta in which the quasiparticle occupancies lie between 0 and 1 even at T=0. The latter, non-idempotent solution is revealed by analysis of a Poincaré mapping associated with the fundamental Landau equation connecting n(p) and ɛ(p) and validated by solution of a variational condition that yields the symmetry-preserving ground state. Significantly, this extraordinary solution carries the burden of a large temperature-dependent excess entropy down to very low temperatures, threatening violation of the Nernst Theorem. It is argued that certain low-temperature phase transitions, notably those involving Cooper-pair formation, offer effective mechanisms for shedding the entropy excess. Available measurements in heavy-fermion compounds provide concrete support for such a scenario.

  19. Fluconazole dosing predictions in critically-ill patients receiving prolonged intermittent renal replacement therapy: a Monte Carlo simulation approach.

    PubMed

    Gharibian, Katherine N; Mueller, Bruce A

    2016-07-01

    Fluconazole is a renally-eliminated antifungal commonly used to treat Candida species infections. In critically-ill patients receiving prolonged intermittent renal replacement therapy (PIRRT), limited pharmacokinetic (PK) data are available to guide fluconazole dosing. We used previously-published fluconazole clearance data and PK data of critically-ill patients with acute kidney injury to develop a PK model with the goal of determining a therapeutic dosing regimen for critically-ill patients receiving PIRRT. Monte Carlo simulations were performed to create a virtual cohort of patients receiving different fluconazole dosing regimens. Plasma drug concentration-time profiles were evaluated on the probability of attaining a mean 24-hour area under the drug concentration-time curve to minimum inhibitory concentration ratio (AUC24h : MIC) of 100 during the initial 48 hours of antifungal therapy. At the susceptibility breakpoint of Candida albicans (2 mg/L), 93 - 96% of simulated subjects receiving PIRRT attained the pharmacodynamic target with a fluconazole 800-mg loading dose plus 400 mg twice daily (q12h or pre and post PIRRT) regimen. Monte Carlo simulations of a PK model of PIRRT provided a basis for the development of an informed fluconazole dosing recommendation when PK data was limited. This finding should be validated in the clinical setting. PMID:27251341

  20. Healing of critical-size segmental defects in rat femora using strong porous bioactive glass scaffolds.

    PubMed

    Bi, Lianxiang; Zobell, Brett; Liu, Xin; Rahaman, Mohamed N; Bonewald, Lynda F

    2014-09-01

    The repair of structural bone defects such as segmental defects in the long bones of the limbs is a challenging clinical problem. In this study, the capacity of silicate (13-93) and borate (13-93B3) bioactive glass scaffolds (porosity=47-50%) to heal critical-size segmental defects in rat femurs was evaluated and compared with autografts. Defects were implanted with 13-93 and 13-93B3 scaffolds with a grid-like microstructure (compressive strength=86 MPa and 40 MPa, respectively), 13-93B3 scaffolds with an oriented microstructure (compressive strength=32 MPa) and autografts using intramedullary fixation. Twelve weeks post-implantation, the defects were harvested and evaluated using histomorphometric analysis. The percentage of new bone in the defects implanted with the three groups of glass scaffolds (25-28%) and the total von Kossa-positive area (32-38%) were not significantly different from the autografts (new bone=38%; von Kossa-positive area=40%) (p>0.05). New blood vessel area in the defects implanted with the glass scaffolds (4-8%) and the autografts (5%) showed no significant difference among the four groups. New cartilage formed in the 13-93 grid-like scaffolds (18%) was significantly higher than in 13-93B3 grid-like scaffolds (8%) and in the autografts (8%) (p=0.02). The results indicate that these strong porous bioactive glass scaffolds are promising synthetic implants for structural bone repair. PMID:25063184

  1. Effectiveness of pharmacist dosing adjustment for critically ill patients receiving continuous renal replacement therapy: a comparative study

    PubMed Central

    Jiang, Sai-Ping; Zhu, Zheng-Yi; Wu, Xiao-Liang; Lu, Xiao-Yang; Zhang, Xing-Guo; Wu, Bao-Hua

    2014-01-01

    Background The impact of continuous renal replacement therapy (CRRT) on drug removal is complicated; pharmacist dosing adjustment for these patients may be advantageous. This study aims to describe the development and implementation of pharmacist dosing adjustment for critically ill patients receiving CRRT and to examine the effectiveness of pharmacist interventions. Methods A comparative study was conducted in an intensive care unit (ICU) of a university-affiliated hospital. Patients receiving CRRT in the intervention group received specialized pharmacy dosing service from pharmacists, whereas patients in the no-intervention group received routine medical care without pharmacist involvement. The two phases were compared to evaluate the outcome of pharmacist dosing adjustment. Results The pharmacist carried out 233 dosing adjustment recommendations for patients receiving CRRT, and 212 (90.98%) of the recommendations were well accepted by the physicians. Changes in CRRT-related variables (n=144, 61.81%) were the most common risk factors for dosing errors, whereas antibiotics (n=168, 72.10%) were the medications most commonly associated with dosing errors. Pharmacist dosing adjustment resulted in a US$2,345.98 ICU cost savings per critically ill patient receiving CRRT. Suspected adverse drug events in the intervention group were significantly lower than those in the preintervention group (35 in 27 patients versus [vs] 18 in eleven patients, P<0.001). However, there was no significant difference between length of ICU stay and mortality after pharmacist dosing adjustment, which was 8.93 days vs 7.68 days (P=0.26) and 30.10% vs 27.36% (P=0.39), respectively. Conclusion Pharmacist dosing adjustment for patients receiving CRRT was well accepted by physicians, and was related with lower adverse drug event rates and ICU cost savings. These results may support the development of strategies to include a pharmacist in the multidisciplinary ICU team. PMID:24940066

  2. Screening and risk factors of exocrine pancreatic insufficiency in critically ill adult patients receiving enteral nutrition

    PubMed Central

    2013-01-01

    Introduction Malnutrition is a frequent problem associated with detrimental clinical outcomes in critically ill patients. To avoid malnutrition, most studies focus on the prevention of inadequate nutrition delivery, whereas little attention is paid to the potential role of exocrine pancreatic insufficiency (EPI). In this trial, we aim to evaluate the prevalence of EPI and identify its potential risk factors in critically ill adult patients without preexisting pancreatic diseases. Methods In this prospective cross-sectional study, we recruited 563 adult patients with critical illnesses. All details of the patients were documented, stool samples were collected three to five days following the initiation of enteral nutrition, and faecal elastase 1 (FE-1) concentrations were assayed using an enzyme-linked immunosorbent assay kit. Blood samples were also taken to determine serum amylase and lipase activity. Results The percentages of recruited patients with EPI (FE-1 concentration <200 μg/g) and severe EPI (FE-1 concentration <100 μg/g) were 52.2% and 18.3%, respectively. The incidences of steatorrhea were significantly different (P < 0.05) among the patients without EPI, with moderate EPI (FE-1 concentration = 100 to 200 μg/g) and severe EPI (FE-1 concentration < 100 μg/g). Both multivariate logistic regression analysis and z-tests indicated that the occurrence of EPI was closely associated with shock, sepsis, diabetes, cardiac arrest, hyperlactacidemia, invasive mechanical ventilation and haemodialysis. Conclusions More than 50% of critically ill adult patients without primary pancreatic diseases had EPI, and nearly one-fifth of them had severe EPI. The risk factors for EPI included shock, sepsis, diabetes, cardiac arrest, hyperlactacidemia, invasive mechanical ventilation and haemodialysis. Trial registration NCT01753024 PMID:23924602

  3. Asymptotically Exact Scenario of Strong-Disorder Criticality in One-Dimensional Superfluids

    NASA Astrophysics Data System (ADS)

    Pollet, Lode; Prokof'ev, Nikolay; Svistunov, Boris

    2014-03-01

    We present a controlled rare-weak-link theory of the superfluid-to-Bose/Mott glass transition in one-dimensional disordered systems. The transition has Kosterlitz-Thouless critical properties but may occur at an arbitrary large value of the Luttinger parameter K. In contrast to the scenario by Altman et al. [Phys. Rev. B 81, 174528 (2010)], the hydrodynamic description is valid under the correlation radius and defines criticality via the renormalization of microscopically weak links, along the lines of Kane and Fisher [Phys. Rev. Lett. 68, 1220 (1992)]. The hallmark of the theory is the relation K (c) = 1 / ζ between the critical value of the Luttinger parameter at macroscopic scales and the microscopic (irrenormalizable) exponent ζ describing the scaling ~ 1 /N 1 - ζ for the strength of the weakest link among the N / L >> 1 disorder realizations in a system of fixed mesoscopic size L.

  4. Evaluation of Critical Care Monitor Technology During the US Navy Strong Angel Exercise

    NASA Technical Reports Server (NTRS)

    Johannesen, John; Rasbury, Jack

    2003-01-01

    The NASA critical path road map identifies "trauma and acute medical problems" as a clinical capability risk category (http://criticalDath.isc.nasa.gov). Specific risks include major trauma, organ laceration or contusion, hemoperitoneum, pulmonary failure, pneumo- and hemothorax, burn, open bone fracture, blunt head trauma, and penetrating injury. Mitigation of these risks includes the capability for critical care monitoring. Currently, the International Space Station (ISS) Crew Health Care System (CHeCS) does not provide such a capability. The Clinical Space Medicine Strategic Planning Forum (4/8/97), sponsored by NASA Medical Operations, identified the development of trauma care capabilities as one of the top priorities for space medicine. The Clinical Care Capability Development Project (CCCDP) subsequently undertook the task to address this need.

  5. A Tool for Music Preference Assessment in Critically Ill Patients Receiving Mechanical Ventilatory Support

    PubMed Central

    CHLAN, LINDA; HEIDERSCHEIT, ANNIE

    2010-01-01

    Music is an ideal intervention to reduce anxiety and promote relaxation in critically ill patients. This article reviews the research studies on music-listening interventions to manage distressful symptoms in this population, and describes the development and implementation of the Music Assessment Tool (MAT) to assist professionals in ascertaining patients’ music preferences in the challenging, dynamic clinical environment of the intensive care unit (ICU). The MAT is easy to use with these patients who experience profound communication challenges due to fatigue and inability to speak because of endotracheal tube placement. The music therapist and ICU nursing staff are encouraged to work collaboratively to implement music in a personalized manner to ensure the greatest benefit for mechanically ventilated patients. PMID:24489432

  6. Ionic Vapor Composition in Critical and Supercritical States of Strongly Interacting Ionic Compounds.

    PubMed

    Chaban, Vitaly V; Prezhdo, Oleg V

    2016-05-12

    The critical point, CP (T, P), of the phase diagram quantifies the minimum amount of kinetic energy needed to prevent a substance from existing in a condensed phase. Therefore, the CP is closely related to the properties of the fluid far below the critical temperature. Approaches designed to predict thermophysical properties of a system necessarily aim to provide reliable estimates of the CP. Vice versa, CP estimation is impossible without knowledge of the vapor phase behavior. We report ab initio Born-Oppenheimer molecular dynamics (BOMD) simulations of sodium and potassium chlorides, NaCl and KCl, at and above their expected CPs. We advance the present knowledge regarding the existence of ionic species in the vapor phase by establishing significant percentages of atomic clusters: 29-30% in NaCl and 34-38% in KCl. A neutral pair of counterions is the most abundant cluster in the ionic vapors (ca. 35% of all vaporized ions exist in this form). Unexpectedly, an appreciable fraction of clusters is charged. The ionic vapor composition is determined by the vapor density, rather than the nature of the alkali ion. The previously suggested CPs of NaCl and KCl appear overestimated, based on the present simulations. The reported results offer essential insights into the ionic fluid properties and assist in development of thermodynamic theories. The ab initio BOMD method has been applied to investigate the vapor phase composition of an ionic fluid for the first time. PMID:27100933

  7. Strong interaction effects and criticality of bosons in shaken optical lattices.

    PubMed

    Zheng, Wei; Liu, Boyang; Miao, Jiao; Chin, Cheng; Zhai, Hui

    2014-10-10

    We study the quantum phase transitions and identify a tricritical point between a normal Bose superfluid, a superfluid that breaks additional Z(2) Ising symmetry, and a Mott insulator in a recent shaken optical lattice experiment. We show that near the transition between normal and Z(2) symmetry breaking superfluids, bosons can condense into a momentum state with high or even locally maximum kinetic energies due to the interaction effect. We present a general low-energy effective field theory that treats both the superfluid transition and the Ising transition in a uniform framework. Using the perturbative renormalization group method, we find that the critical behavior of the quantum phase transition belongs to a universality class different from that of a dilute Bose gas. PMID:25375720

  8. Neutron reflectometry of anionic surfactants on sapphire: A strong maximum in the adsorption near the critical micelle concentration.

    PubMed

    Li, Ning Ning; Thomas, Robert K; Rennie, Adrian R

    2016-06-01

    The adsorption of the anionic surfactants, lithium, sodium and cesium dodecylsulfates, and sodium decylsulfonate, on the positively charged C-plane (0001) of sapphire (alumina) has been measured using neutron reflection. For each of the four surfactants there is a strong maximum in the adsorption at about the critical micelle concentration. The maximum becomes more marked from lithium to cesium. The measurements were reproduced over a range of different physical conditions and could not be accounted for in terms of impurities. The maximum is explained quantitatively by using the combination of a mass action model to calculate the mean activity of the surfactant, and a cooperative model of the adsorption (Frumkin), in which saturation of the layer is not attained until well above the critical micelle concentration. PMID:26990955

  9. Universal lineshapes at the crossover between weak and strong critical coupling in Fano-resonant coupled oscillators

    NASA Astrophysics Data System (ADS)

    Zanotto, Simone; Tredicucci, Alessandro

    2016-04-01

    In this article we discuss a model describing key features concerning the lineshapes and the coherent absorption conditions in Fano-resonant dissipative coupled oscillators. The model treats on the same footing the weak and strong coupling regimes, and includes the critical coupling concept, which is of great relevance in numerous applications; in addition, the role of asymmetry is thoroughly analyzed. Due to the wide generality of the model, which can be adapted to various frameworks like nanophotonics, plasmonics, and optomechanics, we envisage that the analytical formulas presented here will be crucial to effectively design devices and to interpret experimental results.

  10. Universal lineshapes at the crossover between weak and strong critical coupling in Fano-resonant coupled oscillators.

    PubMed

    Zanotto, Simone; Tredicucci, Alessandro

    2016-01-01

    In this article we discuss a model describing key features concerning the lineshapes and the coherent absorption conditions in Fano-resonant dissipative coupled oscillators. The model treats on the same footing the weak and strong coupling regimes, and includes the critical coupling concept, which is of great relevance in numerous applications; in addition, the role of asymmetry is thoroughly analyzed. Due to the wide generality of the model, which can be adapted to various frameworks like nanophotonics, plasmonics, and optomechanics, we envisage that the analytical formulas presented here will be crucial to effectively design devices and to interpret experimental results. PMID:27091489

  11. Universal lineshapes at the crossover between weak and strong critical coupling in Fano-resonant coupled oscillators

    PubMed Central

    Zanotto, Simone; Tredicucci, Alessandro

    2016-01-01

    In this article we discuss a model describing key features concerning the lineshapes and the coherent absorption conditions in Fano-resonant dissipative coupled oscillators. The model treats on the same footing the weak and strong coupling regimes, and includes the critical coupling concept, which is of great relevance in numerous applications; in addition, the role of asymmetry is thoroughly analyzed. Due to the wide generality of the model, which can be adapted to various frameworks like nanophotonics, plasmonics, and optomechanics, we envisage that the analytical formulas presented here will be crucial to effectively design devices and to interpret experimental results. PMID:27091489

  12. Strong enhancement of s -wave superconductivity near a quantum critical point of Ca3Ir4Sn13

    DOE PAGESBeta

    Biswas, P. K.; Guguchia, Z.; Khasanov, R.; Chinotti, M.; Li, L.; Wang, Kefeng; Petrovic, C.; Morenzoni, E.

    2015-11-11

    We repormore » t microscopic studies by muon spin rotation/relaxation as a function of pressure of the Ca3Ir4Sn13 and Sr3Ir4Sn13 system displaying superconductivity and a structural phase transition associated with the formation of a charge density wave (CDW). Our findings show a strong enhancement of the superfluid density and a dramatic increase of the pairing strength above a pressure of ≈ 1.6 GPa giving direct evidence of the presence of a quantum critical point separating a superconducting phase coexisting with CDW from a pure superconducting phase. The superconducting order parameter in both phases has the same s-wave symmetry. In spite of the conventional phonon-mediated BCS character of the weakly correlated (Ca1-xSrx)3Ir4Sn13 system the dependence of the effective superfluid density on the critical temperature puts this compound in the “Uemura” plot close to unconventional superconductors. This system exemplifies that conventional BCS superconductors in the presence of competing orders or multi-band structure can also display characteristics of unconventional superconductors.« less

  13. An Investigation of the Relationship between the Fear of Receiving Negative Criticism and of Taking Academic Risk through Canonical Correlation Analysis

    ERIC Educational Resources Information Center

    Cetin, Bayram; Ilhan, Mustafa; Yilmaz, Ferat

    2014-01-01

    The aim of this study is to examine the relationship between the fear of receiving negative criticism and taking academic risk through canonical correlation analysis-in which a relational model was used. The participants of the study consisted of 215 university students enrolled in various programs at Dicle University's Ziya Gökalp Faculty of…

  14. Strong Opinions Are No Substitute for Balanced Arguments: Comments on Cicchetti, Kaufman, and Sparrow's Critical Appraisal of PCB Cohort Studies

    ERIC Educational Resources Information Center

    Winneke, Gerhard; Walkowiak, Jens; Kramer, Ursula

    2004-01-01

    This paper comments on a critical review of cohort studies on PCB-related neurodevelopmental deficit in young children by D.V. Cicchetti, A.S. Kaufman, and S.S. Sparrow (CKS). Major points of criticism of CKS, namely alleged violation of statistical principles, presumed lack of clinical significance of findings, and alleged insufficient control of…

  15. Evaluation of Sulfobutylether-β-Cyclodextrin Exposure in a Critically Ill Patient Receiving Intravenous Posaconazole While Undergoing Continuous Venovenous Hemofiltration

    PubMed Central

    Morris, Amanda A.; Mueller, Scott W.; Rower, Joseph E.; Washburn, Taylor

    2015-01-01

    We present a 31-year-old female who had undergone an allogeneic bone marrow transplantation and who was started on intravenous posaconazole for pulmonary mycosis while undergoing continuous venovenous hemofiltration (CVVH). We performed steady-state pharmacokinetic evaluations for both posaconazole and sulfobutylether-β-cyclodextrin (SBECD). SBECD was effectively removed by CVVH, with observed exposure similar to that for patients with moderate renal impairment. Intravenous posaconazole at standard doses may be utilized in critically ill patients undergoing CVVH without significant risk of SBECD accumulation. PMID:26259790

  16. Anion gap corrected for albumin, phosphate and lactate is a good predictor of strong ion gap in critically ill patients: a nested cohort study

    PubMed Central

    Zampieri, Fernando Godinho; Park, Marcelo; Ranzani, Otavio Tavares; Maciel, Alexandre Toledo; de Souza, Heraldo Possolo; da Cruz Neto, Luiz Monteiro; da Silva, Fabiano Pinheiro

    2013-01-01

    Objective Corrected anion gap and strong ion gap are commonly used to estimate unmeasured anions. We evaluated the performance of the anion gap corrected for albumin, phosphate and lactate in predicting strong ion gap in a mixed population of critically ill patients. We hypothesized that anion gap corrected for albumin, phosphate and lactate would be a good predictor of strong ion gap, independent of the presence of metabolic acidosis. In addition, we evaluated the impact of strong ion gap at admission on hospital mortality. Methods We included 84 critically ill patients. Correlation and agreement between the anion gap corrected for albumin, phosphate and lactate and strong ion gap was evaluated by the Pearson correlation test, linear regression, a Bland-Altman plot and calculating interclass correlation coefficient. Two subgroup analyses were performed: one in patients with base-excess <-2mEq/L (low BE group - lBE) and the other in patients with base-excess >-2mEq/L (high BE group - hBE). A logistic regression was performed to evaluate the association between admission strong ion gap levels and hospital mortality. Results There was a very strong correlation and a good agreement between anion gap corrected for albumin, phosphate and lactate and strong ion gap in the general population (r2=0.94; bias 1.40; limits of agreement -0.75 to 3.57). Correlation was also high in the lBE group (r2=0.94) and in the hBE group (r2=0.92). High levels of strong ion gap were present in 66% of the whole population and 42% of the cases in the hBE group. Strong ion gap was not associated with hospital mortality by logistic regression. Conclusion Anion gap corrected for albumin, phosphate and lactate and strong ion gap have an excellent correlation. Unmeasured anions are frequently elevated in critically ill patients with normal base-excess. However, there was no association between unmeasured anions and hospital mortality. PMID:24213083

  17. Impact of prospective payments on a tertiary care center receiving large numbers of critically ill patients by aeromedical transport.

    PubMed

    Thomas, F; Larsen, K; Clemmer, T P; Burke, J P; Orme, J F; Napoli, M; Christison, E

    1986-03-01

    To determine the economic impact of federal prospective payments and the potential effect if private insurance payers were to implement similar prospective payments, we examined payments under Medicare diagnosis-related grouping (DRG) reimbursement policies for 105 Medicare and 357 non-Medicare patients admitted to a tertiary care center via air transport. Among the 105 Medicare patients, the average length of stay was 11.4 days and the mortality rate was 24%. Hospital charges exceeded DRG reimbursement for 74% of Medicare patients. A comparison of previous Medicare payment policies to current federal DRG reimbursement resulted in a revenue loss to the hospital of $667,229 ($6335 per patient). For the 357 non-Medicare patients, the average length of stay was 10.8 days, the mortality rate was 10%, and hospital charges exceeded Medicare DRG reimbursement for 78% of the patients. Implementation of DRG-like payments by non-Medicare insurers would create a hospital revenue loss of $2,493,048 ($6983 per patient). We conclude that unless current and planned prospective payment policies are modified, the use of aeromedical transport services to recruit large numbers of critically ill patients to tertiary care centers is economically prohibitive. PMID:3080276

  18. Unusual strong spin-fluctuation effects around the critical pressure of the itinerant Ising-type ferromagnet URhAl

    NASA Astrophysics Data System (ADS)

    Shimizu, Yusei; Braithwaite, Daniel; Salce, Bernard; Combier, Tristan; Aoki, Dai; Hering, Eduardo N.; Ramos, Scheilla M.; Flouquet, Jacques

    2015-03-01

    Resistivity measurements were performed for the itinerant Ising-type ferromagnet URhAl at temperatures down to 40 mK under high pressure up to 7.5 GPa, using single crystals. We found that the critical pressure of the Curie temperature exists at around Pc˜ 5.2 GPa. Near Pc, the A coefficient of the A T2 Fermi-liquid resistivity term below T* is largely enhanced with a maximum around 5.2-5.5 GPa. Above Pc, the exponent of the resistivity ρ (T ) deviates from 2. At Pc, it is close to n =5 /3 , which is expected by the theory of three-dimensional ferromagnetic spin fluctuations for a second-order quantum-critical point (QCP). However, TC(P ) disappears as a first-order phase transition, and the critical behavior of resistivity in URhAl cannot be explained by the theory of a second-order QCP. The first-order nature of the phase transition is weak, and the electron system in URhAl is still dominated by the spin fluctuation at low temperature. With increasing pressure, the non-Fermi-liquid behavior is observed in higher fields. Magnetic field studies point out a ferromagnetic wing structure with a tricritical point (TCP) at ˜4.8 -4.9 GPa in URhAl. One open possibility is that the switch from the ferromagnetic to the paramagnetic states does not occur simply but an intermediate state arises below the TCP as suggested theoretically recently. Quite generally, if a drastic Fermi-surface change occurs through Pc, the nature of the interaction itself may change and lead to the observed unconventional behavior.

  19. Laser imprint reduction for the critical-density foam buffered target driven by a relatively strong foot pulse at early stage of laser implosions

    NASA Astrophysics Data System (ADS)

    Li, J. W.; Kang, W.; He, X. T.; Li, J. H.; Zheng, W. D.

    2015-12-01

    In order to reduce the effect of laser imprint in direct-drive ignition scheme a low-density foam buffered target has been proposed. This target is driven by a laser pulse with a low-intensity foot at the early stage of implosion, which heats the foam and elongates the thermal conduction zone between the laser absorption region and ablation front, increasing the thermal smoothing effect. In this paper, a relatively strong foot pulse is adopted to irradiate the critical-density foam buffered target. The stronger foot, near 1 × 1014 W/cm2, is able to drive a radiative shock in the low-density foam, which helps smooth the shock and further reduce the effect of laser imprint. The radiative shock also forms a double ablation front structure between the two ablation fronts to further stabilize the hydrodynamics, achieving the similar results to a target with a high-Z dopant in the ablator. 2D analysis shows that for the critical-density foam buffered target irradiated by the strong foot pulse, the laser imprint can be reduced due to the radiative shock in the foam and an increased thermal smoothing effect. It seems viable for the critical-density foam buffered target to be driven by a relatively strong foot pulse with the goal of reducing the laser imprint and achieving better implosion symmetry in the direct-drive laser fusion.

  20. Laser imprint reduction for the critical-density foam buffered target driven by a relatively strong foot pulse at early stage of laser implosions

    SciTech Connect

    Li, J. W. He, X. T.; Kang, W.; Li, J. H.; Zheng, W. D.

    2015-12-15

    In order to reduce the effect of laser imprint in direct-drive ignition scheme a low-density foam buffered target has been proposed. This target is driven by a laser pulse with a low-intensity foot at the early stage of implosion, which heats the foam and elongates the thermal conduction zone between the laser absorption region and ablation front, increasing the thermal smoothing effect. In this paper, a relatively strong foot pulse is adopted to irradiate the critical-density foam buffered target. The stronger foot, near 1 × 10{sup 14 }W/cm{sup 2}, is able to drive a radiative shock in the low-density foam, which helps smooth the shock and further reduce the effect of laser imprint. The radiative shock also forms a double ablation front structure between the two ablation fronts to further stabilize the hydrodynamics, achieving the similar results to a target with a high-Z dopant in the ablator. 2D analysis shows that for the critical-density foam buffered target irradiated by the strong foot pulse, the laser imprint can be reduced due to the radiative shock in the foam and an increased thermal smoothing effect. It seems viable for the critical-density foam buffered target to be driven by a relatively strong foot pulse with the goal of reducing the laser imprint and achieving better implosion symmetry in the direct-drive laser fusion.

  1. Anomalously slow relaxation of the system of strongly interacting liquid clusters in a disordered nanoporous medium: Self-organized criticality

    NASA Astrophysics Data System (ADS)

    Borman, V. D.; Tronin, V. N.

    2016-09-01

    It has been shown that changes in the energy of a system of nonwetting liquid clusters confined in a random nanoporous medium in the process of relaxation can be written in the quasiparticle approximation in the form of the sum of the energies of local (metastable) configurations of liquid clusters interacting with clusters in the connected nearest pores. The energy spectrum and density of states of the local configuration have been calculated. It has been shown that the relaxation of the state of the system occurs through the scenario of self-organized criticality (SOC). The process is characterized by the expectation of a fluctuation necessary for overcoming a local energy barrier of the metastable state with the subsequent rapid hydrodynamic extrusion of the liquid under the action of the surface buoyancy forces of the nonwetting framework. In this case, the dependence of the interaction between local configurations on the number of filled pores belonging to the infinite percolation cluster of filled pores serves as an internal feedback initiating the SOC process. The calculations give a power-law time dependence of the relative volume of the confined liquid θ ∼t-α(α ∼ 0.1) . The developed model of the relaxation of the porous medium with the nonwetting liquid demonstrates possible mechanisms and scenarios of SOC for disordered atomic systems.

  2. "I Have Remained Strong Because of That Food": Acceptability and Use of Lipid-Based Nutrient Supplements Among Pregnant HIV-Infected Ugandan Women Receiving Combination Antiretroviral Therapy.

    PubMed

    Young, Sera; Natamba, Barnabas; Luwedde, Flavia; Nyafwono, Dorcas; Okia, Ben; Osterbauer, Beth; Natureeba, Paul; Johnson, Lynn; Michel, Chloe; Zheng, Amy; Robine, Marion; Achan, Jane; Charlebois, Edwin; Cohan, Deb; Havlir, Diane

    2015-08-01

    We evaluated the acceptability and use of macronutrient supplementation among HIV-infected pregnant Ugandan women receiving antiretroviral therapy in a clinical study (NCT 00993031). We first conducted formative research among 56 pregnant and lactating women to select a supplement regimen. Acceptability and use of the supplementation regimen (35 sachets of lipid-based nutrient supplements (LNS) and 4 or 6 kg of instant soy porridge for the household provided monthly) were evaluated among 87 pregnant women. Organoleptic assessments of LNS were favorable. Participants reported consuming LNS a mean of 6.1 days per week, and adherence to recommended consumption behaviors (e.g. frequency, quantity, not sharing) was >80 %. Few women reported negative social consequences of supplementation. The majority of participants also consumed most of the porridge intended for the household. In sum, LNS was acceptable and used regularly. Larger studies to evaluate physical and psychosocial consequences of LNS during pregnancy among HIV-infected women are warranted. PMID:25416075

  3. Association between Accessory Gene Regulator Polymorphism and Mortality among Critically Ill Patients Receiving Vancomycin for Nosocomial MRSA Bacteremia: A Cohort Study

    PubMed Central

    Cechinel, Angélica; Machado, Denise P.; Turra, Eduardo; Pereira, Dariane; dos Santos, Rodrigo P.; Rosa, Regis G.; Goldani, Luciano Z.

    2016-01-01

    Background. Polymorphism of the accessory gene regulator group II (agr) in methicillin-resistant Staphylococcus aureus (MRSA) is predictive of vancomycin failure therapy. Nevertheless, the impact of group II agr expression on mortality of patients with severe MRSA infections is not well established. Objective. The goal of our study was to evaluate the association between agr polymorphism and all-cause in-hospital mortality among critically ill patients receiving vancomycin for nosocomial MRSA bacteremia. Methods. All patients with documented bacteremia by MRSA requiring treatment in the ICU between May 2009 and November 2011 were included in the study. Cox proportional hazards regression was performed to evaluate whether agr polymorphism was associated with all-cause in-hospital mortality. Covariates included age, APACHE II score, initial C-reactive protein plasma levels, initial serum creatinine levels, vancomycin minimum inhibitory concentration, vancomycin serum levels, and time to effective antibiotic administration. Results. The prevalence of group I and group II agr expression was 52.4% and 47.6%, respectively. Bacteremia by MRSA group III or group IV agr was not documented in our patients. The mean APACHE II of the study population was 24.3 (standard deviation 8.5). The overall cohort mortality was 66.6% (14 patients). After multivariate analysis, initial plasma C-reactive protein levels (P = 0.01), initial serum creatinine levels (P = 0.008), and expression of group II agr (P = 0.006) were positively associated with all-cause in-hospital mortality. Patients with bacteremia by MRSA with group II agr expression had their risk of death increased by 12.6 times when compared with those with bacteremia by MRSA with group I agr expression. Conclusion. Group II agr polymorphism is associated with an increase in mortality in critically ill patients with bacteremia by MRSA treated with vancomycin. PMID:27366180

  4. Association between Accessory Gene Regulator Polymorphism and Mortality among Critically Ill Patients Receiving Vancomycin for Nosocomial MRSA Bacteremia: A Cohort Study.

    PubMed

    Cechinel, Angélica; Machado, Denise P; Turra, Eduardo; Pereira, Dariane; Dos Santos, Rodrigo P; Rosa, Regis G; Goldani, Luciano Z

    2016-01-01

    Background. Polymorphism of the accessory gene regulator group II (agr) in methicillin-resistant Staphylococcus aureus (MRSA) is predictive of vancomycin failure therapy. Nevertheless, the impact of group II agr expression on mortality of patients with severe MRSA infections is not well established. Objective. The goal of our study was to evaluate the association between agr polymorphism and all-cause in-hospital mortality among critically ill patients receiving vancomycin for nosocomial MRSA bacteremia. Methods. All patients with documented bacteremia by MRSA requiring treatment in the ICU between May 2009 and November 2011 were included in the study. Cox proportional hazards regression was performed to evaluate whether agr polymorphism was associated with all-cause in-hospital mortality. Covariates included age, APACHE II score, initial C-reactive protein plasma levels, initial serum creatinine levels, vancomycin minimum inhibitory concentration, vancomycin serum levels, and time to effective antibiotic administration. Results. The prevalence of group I and group II agr expression was 52.4% and 47.6%, respectively. Bacteremia by MRSA group III or group IV agr was not documented in our patients. The mean APACHE II of the study population was 24.3 (standard deviation 8.5). The overall cohort mortality was 66.6% (14 patients). After multivariate analysis, initial plasma C-reactive protein levels (P = 0.01), initial serum creatinine levels (P = 0.008), and expression of group II agr (P = 0.006) were positively associated with all-cause in-hospital mortality. Patients with bacteremia by MRSA with group II agr expression had their risk of death increased by 12.6 times when compared with those with bacteremia by MRSA with group I agr expression. Conclusion. Group II agr polymorphism is associated with an increase in mortality in critically ill patients with bacteremia by MRSA treated with vancomycin. PMID:27366180

  5. CADM1 is a strong neuroblastoma candidate gene that maps within a 3.72 Mb critical region of loss on 11q23

    PubMed Central

    Michels, Evi; Hoebeeck, Jasmien; De Preter, Katleen; Schramm, Alexander; Brichard, Bénédicte; De Paepe, Anne; Eggert, Angelika; Laureys, Geneviève; Vandesompele, Jo; Speleman, Frank

    2008-01-01

    Background Recurrent loss of part of the long arm of chromosome 11 is a well established hallmark of a subtype of aggressive neuroblastomas. Despite intensive mapping efforts to localize the culprit 11q tumour suppressor gene, this search has been unsuccessful thus far as no sufficiently small critical region could be delineated for selection of candidate genes. Methods To refine the critical region of 11q loss, the chromosome 11 status of 100 primary neuroblastoma tumours and 29 cell lines was analyzed using a BAC array containing a chromosome 11 tiling path. For the genes mapping within our refined region of loss, meta-analysis on published neuroblastoma mRNA gene expression datasets was performed for candidate gene selection. The DNA methylation status of the resulting candidate gene was determined using re-expression experiments by treatment of neuroblastoma cells with the demethylating agent 5-aza-2'-deoxycytidine and bisulphite sequencing. Results Two small critical regions of loss within 11q23 at chromosomal band 11q23.1-q23.2 (1.79 Mb) and 11q23.2-q23.3 (3.72 Mb) were identified. In a first step towards further selection of candidate neuroblastoma tumour suppressor genes, we performed a meta-analysis on published expression profiles of 692 neuroblastoma tumours. Integration of the resulting candidate gene list with expression data of neuroblastoma progenitor cells pinpointed CADM1 as a compelling candidate gene. Meta-analysis indicated that CADM1 expression has prognostic significance and differential expression for the gene was noted in unfavourable neuroblastoma versus normal neuroblasts. Methylation analysis provided no evidence for a two-hit mechanism in 11q deleted cell lines. Conclusion Our study puts CADM1 forward as a strong candidate neuroblastoma suppressor gene. Further functional studies are warranted to elucidate the role of CADM1 in neuroblastoma development and to investigate the possibility of CADM1 haploinsufficiency in neuroblastoma. PMID

  6. CALUTRON RECEIVER

    DOEpatents

    Barnes, S.W.

    1959-06-16

    An improved receiver and receiver mount for calutrons are described. The receiver can be manipulated from outside the tank by a single control to position it with respect to the beam. A door can be operated exteriorly also to prevent undesired portions of the beam from entering the receiver. The receiver has an improved pocket which is more selective in the ions collected. (T.R.H.)

  7. Low Genetic Diversity and Strong Geographical Structure of the Critically Endangered White-Headed Langur (Trachypithecus leucocephalus) Inferred from Mitochondrial DNA Control Region Sequences

    PubMed Central

    Wang, Weiran; Qiao, Yu; Pan, Wenshi; Yao, Meng

    2015-01-01

    Many Asian colobine monkey species are suffering from habitat destruction and population size decline. There is a great need to understand their genetic diversity, population structure and demographic history for effective species conservation. The white-headed langur (Trachypithecus leucocephalus) is a Critically Endangered colobine species endemic to the limestone karst forests in southwestern China. We analyzed the mitochondrial DNA (mtDNA) control region sequences of 390 fecal samples from 40 social groups across the main distribution areas, which represented one-third of the total extant population. Only nine haplotypes and 10 polymorphic sites were identified, indicating remarkably low genetic diversity in the species. Using a subset of 77 samples from different individuals, we evaluated genetic variation, population structure, and population demographic history. We found very low values of haplotype diversity (h = 0.570 ± 0.056) and nucleotide diversity (π = 0.00323 ± 0.00044) in the hypervariable region I (HVRI) of the mtDNA control region. Distribution of haplotypes displayed marked geographical pattern, with one population (Chongzuo, CZ) showing a complete lack of genetic diversity (having only one haplotype), whereas the other population (Fusui, FS) having all nine haplotypes. We detected strong population genetic structure among habit patches (ΦST = 0.375, P < 0.001). In addition, the Mantel test showed a significant correlation between the pairwise genetic distances and geographical distances among social groups in FS (correlation coefficient = 0.267, P = 0.003), indicting isolation-by-distance pattern of genetic divergence in the mtDNA sequences. Analyses of demographic history suggested an overall stable historical population size and modest population expansion in the last 2,000 years. Our results indicate different genetic diversity and possibly distinct population history for different local populations, and suggest that CZ and FS should be

  8. CALUTRON RECEIVER

    DOEpatents

    Brunk, W.O.

    1959-09-29

    A description is given for an improved calutron receiver having a face plate lying at an angle to the direction of the entering ion beams but having an opening, the plane of which is substantially perpendicular to that of the entering ion beams. By so positioning the opening in the receiver, the effective area through which the desired material may enter the receiver is increased, and at the same time the effective area through which containattng material may enter the receiver is reduced.

  9. CALUTRON RECEIVER

    DOEpatents

    York, H.F.

    1959-07-01

    A receiver construction is presented for calutrons having two or more ion sources and an individual receiver unit for each source. Design requirements dictate that the face plate defining the receiver entrance slots be placed at an angle to the approaching beam, which means that ions striking the face plate are likely to be scattcred into the entrance slots of other receivers. According to the present invention, the face plate has a surface provided with parallel ridges so disposed that one side only of each ridge's exposed directly to the ion beam. The scattered ions are directed away from adjacent receivers by the ridges on the lace plate.

  10. Radio receivers

    NASA Astrophysics Data System (ADS)

    Bankov, V. N.; Barulin, L. G.; Zhodzishskii, M. I.; Malyshev, I. V.; Petrusinskii, V. V.

    The book is concerned with the design of microelectronic radio receivers and their components based on semiconductor and hybrid integrated circuits. Topics discussed include the hierarchical structure of radio receivers, the synthesis of structural schemes, the design of the principal functional units, and the design of radio receiver systems with digital signal processing. The discussion also covers the integrated circuits of multifunctional amplifiers, analog multipliers, charge-transfer devices, frequency filters, piezoelectronic devices, and microwave amplifiers, filters, and mixers.

  11. CALUTRON RECEIVERS

    DOEpatents

    Lofgren, E.J.

    1958-09-01

    Improvements are described in isotope separation devices of the calutron type and, in particular, deals with a novel caiutron receiver which passes the optimum portions of the ion beam to a collecting chamber. In broad aspects the receiver provides means for pass delimited pontion of the beam and an elongated collecting pocket disposed to receive ions passed by the beam delimiting means. The collecting pocket is transversely partitioned into a plurality of ion receiving compartments respectively defined by a corresponding plurality of separately removable liner elements.

  12. CALUTRON RECEIVERS

    DOEpatents

    Schmidt, F.H.; Stone, K.F.

    1958-09-01

    S>This patent relates to improvements in calutron devices and, more specifically, describes a receiver fer collecting the ion curreot after it is formed into a beam of non-homogeneous isotropic cross-section. The invention embodies a calutron receiver having an ion receiving pocket for separately collecting and retaining ions traveling in a selected portion of the ion beam and anelectrode for intercepting ions traveling in another selected pontion of the ion beam. The electrode is disposed so as to fix the limit of one side of the pontion of the ion beam admitted iato the ion receiving pocket.

  13. Whose Education Policies in Aid-Receiving Countries? A Critical Discourse Analysis of Quality and Normative Transfer through Cambodia and Laos

    ERIC Educational Resources Information Center

    McCormick, Alexandra

    2012-01-01

    Critical discourse analysis of policy contexts and documents has been employed in this research to analyze the role of language in promoting normative positions affecting the quality of education in Cambodia and Laos. The article examines the ways institutional normative influences at multiple levels within the Education for All (EFA) program have…

  14. CALUTRON RECEIVERS

    DOEpatents

    MacKenzie, K.R.

    1958-09-16

    A novel calutron receiver is described for collecting the constituent material of two closely adjacent selected portions of an ion beam in separate compartments. The receiver is so conntructed that ion scatter and intermixing of the closely adjacent beam portions do nnt occur when the ions strike the receiver structure, and the beam is sharply separated Into the two compartments. In essence, these desirable results are achieved by inclining the adjoining wall of one compartment with respect to the approaching ions to reduce possible rebounding of ions from the compartment into the adjacent compartment.

  15. Clinical Validation of Therapeutic Drug Monitoring of Imipenem in Spent Effluent in Critically Ill Patients Receiving Continuous Renal Replacement Therapy: A Pilot Study

    PubMed Central

    Wen, Aiping; Li, Zhe; Yu, Junxian; Li, Ren; Cheng, Sheng; Duan, Meili; Bai, Jing

    2016-01-01

    Objectives The primary objective of this pilot study was to investigate whether the therapeutic drug monitoring of imipenem could be performed with spent effluent instead of blood sampling collected from critically ill patients under continuous renal replacement therapy. Methods A prospective open-label study was conducted in a real clinical setting. Both blood and effluent samples were collected pairwise before imipenem administration and 0.5, 1, 1.5, 2, 3, 4, 6, and 8 h after imipenem administration. Plasma and effluent imipenem concentrations were determined by reversed-phase high-performance liquid chromatography with ultraviolet detection. Pharmacokinetic and pharmacodynamic parameters of blood and effluent samples were calculated. Results Eighty-three paired plasma and effluent samples were obtained from 10 patients. The Pearson correlation coefficient of the imipenem concentrations in plasma and effluent was 0.950 (P<0.0001). The average plasma-to-effluent imipenem concentration ratio was 1.044 (95% confidence interval, 0.975 to 1.114) with Bland-Altman analysis. No statistically significant difference was found in the pharmacokinetic and pharmacodynamic parameters tested in paired plasma and effluent samples with Wilcoxon test. Conclusion Spent effluent of continuous renal replacement therapy could be used for therapeutic drug monitoring of imipenem instead of blood sampling in critically ill patients. PMID:27093294

  16. Microscale receiver operating characteristic analysis of micrometastasis recognition using activatable fluorescent probes indicates leukocyte imaging as a critical factor to enhance accuracy

    NASA Astrophysics Data System (ADS)

    Spring, Bryan Q.; Palanisami, Akilan; Hasan, Tayyaba

    2014-06-01

    Molecular-targeted probes are emerging with applications for optical biopsy of cancer. An underexplored potential clinical use of these probes is to monitor residual cancer micrometastases that escape cytoreductive surgery and chemotherapy. Here, we show that leukocytes, or white blood cells, residing in nontumor tissues-as well as those infiltrating micrometastatic lesions-uptake cancer cell-targeted, activatable immunoconjugates nonspecifically, which limits the accuracy and resolution of micrometastasis recognition using these probes. Receiver operating characteristic analysis of freshly excised tissues from a mouse model of peritoneal carcinomatosis suggests that dual-color imaging, adding an immunostain for leukocytes, offers promise for enabling accurate recognition of single cancer cells. Our results indicate that leukocyte identification improves micrometastasis recognition sensitivity and specificity from 92 to 93%-for multicellular metastases >20 to 30 μm in size-to 98 to 99.9% for resolving metastases as small as a single cell.

  17. Strong Coupling Superconductivity in the Vicinity of the Structural Quantum Critical Point in (CaxSr1-x)3Rh4Sn13

    NASA Astrophysics Data System (ADS)

    Yu, Wing Chi; Cheung, Yiu Wing; Saines, Paul J.; Imai, Masaki; Matsumoto, Takuya; Michioka, Chishiro; Yoshimura, Kazuyoshi; Goh, Swee K.

    The family of the superconducting quasiskutterudites (CaxSr1-x)3Rh4Sn13 features a structural quantum critical point at xc = 0 . 9 , around which a dome-shaped variation of the superconducting transition temperature Tc is found. In this talk, we present the specific heat data for the normal and the superconducting states of the entire series straddling the quantum critical point. Our analysis indicates a significant lowering of the effective Debye temperature on approaching xc, which we interpret as a result of phonon softening accompanying the structural instability. Furthermore, a remarkably large enhancement of 2 Δ /kBTc and ΔC / γTc beyond the Bardeen-Cooper-Schrieffer values is found in the vicinity of the structural quantum critical point. Reference: Wing Chi Yu et al. Phys. Rev. Lett. (in press, 2015) This work was supported by the CUHK (Startup Grant, Direct Grant No. 4053071), UGC Hong Kong (ECS/24300214), Grants-in-Aid from MEXT (22350029 and 23550152), and Glasstone Bequest, Oxford.

  18. CALUTRON RECEIVER

    DOEpatents

    Barnes, S.W.

    1959-08-25

    An improvement in a calutron receiver for collecting the isotopes ts described. The electromagnetic separation of the isotopes produces a mass spectrum of closely adjacent beams of ions at the foci regions, and a dividing wall between the two pockets is arranged at an angle. Substantially all of the tons of the less abundant isotope enter one of the pockets and strike one side of the wall directly, while substantially none of the tons entering the other pocket strikes the wall directly.

  19. Strong Interaction

    SciTech Connect

    Karsch, F.; Vogelsang, V.

    2009-09-29

    We will give here an overview of our theory of the strong interactions, Quantum Chromo Dynamics (QCD) and its properties. We will also briefly review the history of the study of the strong interactions, and the discoveries that ultimately led to the formulation of QCD. The strong force is one of the four known fundamental forces in nature, the others being the electromagnetic, the weak and the gravitational force. The strong force, usually referred to by scientists as the 'strong interaction', is relevant at the subatomic level, where it is responsible for the binding of protons and neutrons to atomic nuclei. To do this, it must overcome the electric repulsion between the protons in an atomic nucleus and be the most powerful force over distances of a few fm (1fm=1 femtometer=1 fermi=10{sup -15}m), the typical size of a nucleus. This property gave the strong force its name.

  20. Radiation receiver

    DOEpatents

    Hunt, A.J.

    1983-09-13

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.

  1. Radiation receiver

    DOEpatents

    Hunt, Arlon J.

    1983-01-01

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.

  2. Pre-Transplant Donor-Specific T-Cell Alloreactivity Is Strongly Associated with Early Acute Cellular Rejection in Kidney Transplant Recipients Not Receiving T-Cell Depleting Induction Therapy

    PubMed Central

    Crespo, Elena; Lucia, Marc; Cruzado, Josep M.; Luque, Sergio; Melilli, Edoardo; Manonelles, Anna; Lloberas, Nuria; Torras, Joan; Grinyó, Josep M.; Bestard, Oriol

    2015-01-01

    Preformed T-cell immune-sensitization should most likely impact allograft outcome during the initial period after kidney transplantation, since donor-specific memory T-cells may rapidly recognize alloantigens and activate the effector immune response, which leads to allograft rejection. However, the precise time-frame in which acute rejection is fundamentally triggered by preformed donor-specific memory T cells rather than by de novo activated naïve T cells is still to be established. Here, preformed donor-specific alloreactive T-cell responses were evaluated using the IFN-γ ELISPOT assay in a large consecutive cohort of kidney transplant patients (n = 90), to assess the main clinical variables associated with cellular sensitization and its predominant time-frame impact on allograft outcome, and was further validated in an independent new set of kidney transplant recipients (n = 67). We found that most highly T-cell sensitized patients were elderly patients with particularly poor HLA class-I matching, without any clinically recognizable sensitizing events. While one-year incidence of all types of biopsy-proven acute rejection did not differ between T-cell alloreactive and non-alloreactive patients, Receiver Operating Characteristic curve analysis indicated the first two months after transplantation as the highest risk time period for acute cellular rejection associated with baseline T-cell sensitization. This effect was particularly evident in young and highly alloreactive individuals that did not receive T-cell depletion immunosuppression. Multivariate analysis confirmed preformed T-cell sensitization as an independent predictor of early acute cellular rejection. In summary, monitoring anti-donor T-cell sensitization before transplantation may help to identify patients at increased risk of acute cellular rejection, particularly in the early phases after kidney transplantation, and thus guide decision-making regarding the use of induction therapy. PMID:25689405

  3. Trends in Concentrator, Receiver, and Storage Development for Terrestrial Applications

    NASA Technical Reports Server (NTRS)

    Roschke, E. J.; Owen, W. A.; Menard, W. A.; Fujita, T.

    1984-01-01

    The experience gained and the technical trends of the DOE-sponsored terrestrial solar thermal power systems project are summarized with respect to concentrator and receiver/storage development. Relevance of this experience to space power applications, and the perceived critical barriers of this technology, are discussed. It is concluded that, despite different objectives, the terrestrial program provides a strong basis of expertise valuable to space power applications development.

  4. Strong enhancement of s-wave superconductivity near a quantum critical point of (Ca1-xSrx)3Ir4Sn13 and (Ca1-xSrx)3Rh4Sn13

    NASA Astrophysics Data System (ADS)

    Morenzoni, Elvezio; Biswas, Pabitra; Guguchia, Zurab; Khasanov, Rustem; Chinotti, Manuel; Krieger, Jonas; Li, L.; Wang, Kefeng; Petrovic, Cedomir; Pomjakushina, Ekaterina

    We report microscopic studies by muon spin rotation as a function of pressure of the (Ca1-xSrx)3Ir4Sn13 and (Ca1-xSrx)3Rh4Sn13 cubic compounds, which display superconductivity and a structural phase transition associated with the formation of a charge density wave (CDW). In Ca3Ir4Sn13 we find a strong enhancement of the superfluid density and a dramatic increase of the pairing strength above a pressure of ~ 1 . 6 GPa giving direct evidence of the presence of a quantum critical point separating a superconducting phase coexisting with CDW from a pure superconducting phase. The superconducting order parameter in both phases has the same s-wave symmetry. Similar behavior is found in the other family. In spite of the conventional phonon-mediated BCS character of these weakly correlated 3-4-13 systems, the dependence of the effective superfluid density on the critical temperature put these compounds in the ``Uemura'' plot close to unconventional superconductors. These systems exemplify that conventional BCS superconductors can also display characteristics of unconventional superconductors. Supported by the Swiss National Science Foundation and by the U.S. DOE under Contract No. DE-SC00112704.

  5. Myeloablative 131I-Tositumomab Radioimmunotherapy in Treating Non-Hodgkin’s Lymphoma: Comparison of Dosimetry Based on Whole-Body Retention and Dose to Critical Organ Receiving the Highest Dose

    SciTech Connect

    Rajendran, Joseph G.; Gopal, Ajay K.; Fisher, Darrell R.; Durack, L. D.; Gooley, Ted; Press, Oliver W.

    2008-05-01

    Objectives: Myeloablative radioimmunotherapy (RIT) using 131I tositumomab (anti-CD 20) monoclonal antibodies is an effective new therapy for B-cell non-Hodgkins lymphoma (NHL). The goal of this work is to determine optimum methods to deliver maximal myeloablative radioactivity without exceeding the radiation tolerance of critical normal organs such as liver and lungs, and avoiding serious toxicity. Methods: We reviewed dosimetry records for 100 consecutive patients who underwent biodistribution and dosimetry after a test infusion of 131I- tositumomab. Serial gamma camera images were used to determine organ and tissue activities over time and to calculate radiation-absorbed doses. Volumes of critical normal organs were determined from CT scans to adjust the dose estimates for the individual patient. These dose estimates helped us determine an appropriate therapy based on projected dose to the critical normal organ receiving a maximum tolerable radiation dose. We compared our method of organ-specific dosimetry for treatment planning with the standard clinical approaches using a whole-body dose-assessment method by assessing the difference in projected amounts of radiation-absorbed doses, as well as the ratios of projected amounts, that would be prescribed for therapy by each of these two strategies. Results: The mean organ doses (mGy/MBq) estimated by both methods were (1) Whole body method: liver = 0.33 and lungs = 0.33; and (2) Organ-specific method: liver 1.52 and lungs 1.72 (p = .0001). The median difference between the radiation-absorbed dose estimates was 3.40 (range of 1.37 to 7.96) for the lungs, 3.05 (range of 1.04 to 6.20) for the liver, and –0.05 for whole body (range of –0.18 to 0.16). The median ratio (OS divided by WB method) of radiation-absorbed dose estimates was 5.12 (range of 2.33 to 10.01) for the lungs, 4.14 (range of 2.16 to 6.67) for the liver, and 0.94 (range of 0.79 to 1.22) for whole body. There was significant difference between the

  6. 21 CFR 1020.10 - Television receivers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... designed to receive and display a television picture through broadcast, cable, or closed circuit television... parallel to the external surface of the receiver with an area of ten (10) square centimeters and no... from that component or circuit failure which maximizes x-radiation emissions. (4) Critical...

  7. 21 CFR 1020.10 - Television receivers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... designed to receive and display a television picture through broadcast, cable, or closed circuit television... parallel to the external surface of the receiver with an area of ten (10) square centimeters and no... from that component or circuit failure which maximizes x-radiation emissions. (4) Critical...

  8. 21 CFR 1020.10 - Television receivers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... designed to receive and display a television picture through broadcast, cable, or closed circuit television... parallel to the external surface of the receiver with an area of ten (10) square centimeters and no... from that component or circuit failure which maximizes x-radiation emissions. (4) Critical...

  9. 21 CFR 1020.10 - Television receivers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... designed to receive and display a television picture through broadcast, cable, or closed circuit television... parallel to the external surface of the receiver with an area of ten (10) square centimeters and no... from that component or circuit failure which maximizes x-radiation emissions. (4) Critical...

  10. 21 CFR 1020.10 - Television receivers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... designed to receive and display a television picture through broadcast, cable, or closed circuit television... parallel to the external surface of the receiver with an area of ten (10) square centimeters and no... from that component or circuit failure which maximizes x-radiation emissions. (4) Critical...

  11. Spaceborne receivers: Basic principles

    NASA Technical Reports Server (NTRS)

    Stacey, J. M.

    1984-01-01

    The underlying principles of operation of microwave receivers for space observations of planetary surfaces were examined. The design philosophy of the receiver as it is applied to operate functionally as an efficient receiving system, the principle of operation of the key components of the receiver, and the important differences among receiver types are explained. The operating performance and the sensitivity expectations for both the modulated and total power receiver configurations are outlined. The expressions are derived from first principles and are developed through the important intermediate stages to form practicle and easily applied equations. The transfer of thermodynamic energy from point to point within the receiver is illustrated. The language of microwave receivers is applied statistics.

  12. Solar heat receiver

    DOEpatents

    Hunt, A.J.; Hansen, L.J.; Evans, D.B.

    1982-09-29

    A receiver is described for converting solar energy to heat a gas to temperatures from 700 to 900/sup 0/C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

  13. Dealing with criticism

    NASA Astrophysics Data System (ADS)

    Morris, Giles

    2013-03-01

    Physics graduates are accustomed to receiving feedback from teachers, tutors and lecturers, but different expectations and norms prevail in the workplace. Giles Morris discusses how to handle criticism at work.

  14. Optical superheterodyne receiver.

    NASA Technical Reports Server (NTRS)

    Duval, K.; Lang, K.; Lucy, R. F.; Peters, C. J.

    1967-01-01

    Optical communication experiments to compare coherent and noncoherent optical detection fading characteristics in different weather conditions, using laser transmitter and optical superheterodyne receiver

  15. Hybrid receiver study

    NASA Technical Reports Server (NTRS)

    Stone, M. S.; Mcadam, P. L.; Saunders, O. W.

    1977-01-01

    The results are presented of a 4 month study to design a hybrid analog/digital receiver for outer planet mission probe communication links. The scope of this study includes functional design of the receiver; comparisons between analog and digital processing; hardware tradeoffs for key components including frequency generators, A/D converters, and digital processors; development and simulation of the processing algorithms for acquisition, tracking, and demodulation; and detailed design of the receiver in order to determine its size, weight, power, reliability, and radiation hardness. In addition, an evaluation was made of the receiver's capabilities to perform accurate measurement of signal strength and frequency for radio science missions.

  16. Data-fusion receiver

    DOEpatents

    Gabelmann, Jeffrey M.; Kattner, J. Stephen; Houston, Robert A.

    2006-12-19

    This invention is an ultra-low frequency electromagnetic telemetry receiver which fuses multiple input receive sources to synthesize a decodable message packet from a noise corrupted telemetry message string. Each block of telemetry data to be sent to the surface receiver from a borehole tool is digitally encoded into a data packet prior to transmission. The data packet is modulated onto the ULF EM carrier wave and transmitted from the borehole to the surface and then are simultaneously detected by multiple receive sensors disbursed within the rig environment. The receive sensors include, but are not limited to, electric field and magnetic field sensors. The spacing of the surface receive elements is such that noise generators are unequally coupled to each receive element due to proximity and/or noise generator type (i.e. electric or magnetic field generators). The receiver utilizes a suite of decision metrics to reconstruct the original, non noise-corrupted data packet from the observation matrix via the estimation of individual data frames. The receiver will continue this estimation process until: 1) the message validates, or 2) a preset "confidence threshold" is reached whereby frames within the observation matrix are no longer "trusted".

  17. 30 GHz Commercial Satellite Receivers

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Ponchak, George E.; Romanofsky, Robert R.

    1989-01-01

    NASA's research and development work in satellite communications for the past 10 years has included a major technology thrust aimed at opening the Ka frequency band to commercial exploitation. This has included the development and testing of advanced system network architectures, on-board switching and processing, multibeam and phased array antennas, and satellite and ground terminal RF and digital hardware. Development work in system hardware has focused on critical components including power amplifiers, satellite IF switch matrices, low noise receivers, baseband processors, and high data rate bandwidth efficient modems. This paper describes NASA's work in developing and testing 30 GHz low noise satellite receivers for commercial space communications uplink applications. Frequencies allotted for fixed service commercial satellite communications in the Ka band are 27.5 - 30.0 GHz for uplink transmission and 17.7 - 20.2 GHz for downlink transmission. The relatively large 2.5 GHz bandwidth lends itself to wideband, high data rate digital transmission applications.

  18. Right to Receive.

    ERIC Educational Resources Information Center

    Oborn, Richard

    The concept of a United States citizen's right to receive information is acquiring increased judicial recognition. This report traces the evolution of that right from its philosophical basis in the United States Consitution, through its interpretation by the Supreme Court, up to the current concern that the public receive certain economic…

  19. CALUTRON RECEIVER STRUCTURE

    DOEpatents

    Roush, J.L.

    1959-09-01

    A receiver is described for collecting isotopes in a calutron The receiver has several compartments, formed by a sertes of parallel metal plates and an open front. Each plate has flanges which space it from the other plates and a flexible extension pressing against a common supporting red to maintain the plate in assembled relation when all but the last rod is removed. The plates may be removed individualy from the front of the receiver, cleaned ard replaced without disturbing the alignment of the other plates.

  20. Critical dynamics in multicomponent lipid membranes.

    PubMed

    Haataja, Mikko

    2009-08-01

    The formation and dynamics of spatially extended compositional domains in multicomponent lipid membranes both in vivo and in vitro lie at the heart of many important biological and biophysical phenomena. While the thermodynamic basis for domain formation has been explored extensively in the past, the roles of membrane and exterior fluid hydrodynamics on domain formation kinetics have received less attention. A case in point is the impact of hydrodynamics on the dynamics of compositional heterogeneities in lipid membranes in the vicinity of a critical point. In this Rapid Communication it is argued that the asymptotic dynamic behavior of a lipid membrane system in the vicinity of a critical point is strongly influenced by hydrodynamic interactions. More specifically, a mode-coupling argument is developed which predicts a scaling behavior of lipid transport coefficients near the critical point for both symmetric and asymmetric bilayers immersed in a bulk fluid. PMID:19792068

  1. Ultrasonic pulser-receiver

    SciTech Connect

    Taylor, Steven C.

    2006-09-12

    Ultrasonic pulser-receiver circuitry, for use with an ultrasonic transducer, the circuitry comprising a circuit board; ultrasonic pulser circuitry supported by the circuit board and configured to be coupled to an ultrasonic transducer and to cause the ultrasonic transducer to emit an ultrasonic output pulse; receiver circuitry supported by the circuit board, coupled to the pulser circuitry, including protection circuitry configured to protect against the ultrasonic pulse and including amplifier circuitry configured to amplify an echo, received back by the transducer, of the output pulse; and a connector configured to couple the ultrasonic transducer directly to the circuit board, to the pulser circuitry and receiver circuitry, wherein impedance mismatches that would result if the transducer was coupled to the circuit board via a cable can be avoided.

  2. Ceramic Solar Receiver

    NASA Technical Reports Server (NTRS)

    Robertson, C., Jr.

    1984-01-01

    Solar receiver uses ceramic honeycomb matrix to absorb heat from Sun and transfer it to working fluid at temperatures of 1,095 degrees and 1,650 degrees C. Drives gas turbine engine or provides heat for industrial processes.

  3. Solar energy receiver

    DOEpatents

    Schwartz, Jacob

    1978-01-01

    An improved long-life design for solar energy receivers provides for greatly reduced thermally induced stress and permits the utilization of less expensive heat exchanger materials while maintaining receiver efficiencies in excess of 85% without undue expenditure of energy to circulate the working fluid. In one embodiment, the flow index for the receiver is first set as close as practical to a value such that the Graetz number yields the optimal heat transfer coefficient per unit of pumping energy, in this case, 6. The convective index for the receiver is then set as closely as practical to two times the flow index so as to obtain optimal efficiency per unit mass of material.

  4. Receiver Gain Modulation Circuit

    NASA Technical Reports Server (NTRS)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  5. Highly directional acoustic receivers.

    PubMed

    Cray, Benjamin A; Evora, Victor M; Nuttall, Albert H

    2003-03-01

    The theoretical directivity of a single combined acoustic receiver, a device that can measure many quantities of an acoustic field at a collocated point, is presented here. The formulation is developed using a Taylor series expansion of acoustic pressure about the origin of a Cartesian coordinate system. For example, the quantities measured by a second-order combined receiver, denoted a dyadic sensor, are acoustic pressure, the three orthogonal components of acoustic particle velocity, and the nine spatial gradients of the velocity vector. The power series expansion, which can be of any order, is cast into an expression that defines the directivity of a single receiving element. It is shown that a single highly directional dyadic sensor can have a directivity index of up to 9.5 dB. However, there is a price to pay with highly directive sensors; these sensors can be significantly more sensitive to nonacoustic noise sources. PMID:12656387

  6. Central solar energy receiver

    DOEpatents

    Drost, M. Kevin

    1983-01-01

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  7. Submillimeter wave heterodyne receiver

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam (Inventor); Manohara, Harish (Inventor); Siegel, Peter H. (Inventor); Ward, John (Inventor)

    2011-01-01

    In an embodiment, a submillimeter wave heterodyne receiver includes a finline ortho-mode transducer comprising thin tapered metallic fins deposited on a thin dielectric substrate to separate a vertically polarized electromagnetic mode from a horizontally polarized electromagnetic mode. Other embodiments are described and claimed.

  8. Olympus beacon receiver

    NASA Technical Reports Server (NTRS)

    Ostergaard, Jens

    1988-01-01

    A medium-size Beacon Receiving System for reception and processing of the B1 (20 GHz) and B2 (30 GHz) beacons from Olympus has been developed. Integration of B1 and B2 receiving equipment into one system using one antenna and a common computer for control and data processing provides the advantages of a compact configuration and synchronization of the two receiver chains. Range for co-polar signal attenuation meaurement is about 30 dB for both beacons, increasing to 40 dB for B2 if the receivers are synchronized to B1. The accuracy is better than 0.5 dB. Cross-polarization discriminations of the order of 10 to 30 dB may be determined with an accuracy of 1 to 2 dB. A number of radiometers for complementary measurements of atmospheric attenuation of 13 to 30 GHz has also been constructed. A small multi-frequency system for operation around 22 GHz and 31 GHz is presently under development.

  9. Simplified OMEGA receivers

    NASA Technical Reports Server (NTRS)

    Burhans, R. W.

    1974-01-01

    The details are presented of methods for providing OMEGA navigational information including the receiver problem at the antenna and informational display and housekeeping systems based on some 4 bit data processing concepts. Topics discussed include the problem of limiters, zero crossing detectors, signal envelopes, internal timing circuits, phase counters, lane position displays, signal integrators, and software mapping problems.

  10. A digital beacon receiver

    NASA Technical Reports Server (NTRS)

    Ransome, Peter D.

    1988-01-01

    A digital satellite beacon receiver is described which provides measurement information down to a carrier/noise density ratio approximately 15 dB below that required by a conventional (phase locked loop) design. When the beacon signal fades, accuracy degrades gracefully, and is restored immediately (without hysteresis) on signal recovery, even if the signal has faded into the noise. Benefits of the digital processing approach used include the minimization of operator adjustments, stability of the phase measuring circuits with time, repeatability between units, and compatibility with equipment not specifically designed for propagation measuring. The receiver has been developed for the European Olympus satellite which has continuous wave (CW) beacons at 12.5 and 29.7 GHz, and a switched polarization beacon at 19.8 GHz approximately, but the system can be reconfigured for CW and polarization-switched beacons at other frequencies.

  11. Galileo probe relay receiver

    NASA Technical Reports Server (NTRS)

    Prouty, D. A.; Von Der Embse, U. A.

    1982-01-01

    For the Jovian mission, the data link from the Galileo probe to the orbiter uses suppressed-carrier Manchester encoded BPSK modulation and is protected with R = 1/2, K = 7 convolutional coding. The receiver closes the link by acquiring, tracking, and demodulating the data. It has to operate in a highly stressed environment with severe frequency offset, frequency rate, wind gust, and antenna spin conditions. Salient features are described and breadboard test data presented.

  12. Multichannel homodyne receiver

    DOEpatents

    Landt, Jeremy A.

    1982-01-01

    A homodyne radar transmitter/receiver device which produces a single combined output which contains modulated backscatter information for all phase conditions of both modulated and unmodulated backscatter signals. The device utilizes taps along coaxial transmission lines, strip transmission line, and waveguides which are spaced by 1/8 wavelength or 1/6 wavelength, etc. This greatly reduces costs by eliminating separate transmission and reception antennas and an expensive arrangement of power splitters and mixers utilized in the prior art.

  13. Multichannel homodyne receiver

    DOEpatents

    Landt, J.A.

    1981-01-19

    A homodyne radar transmitter/receiver device which produces a single combined output which contains modulated backscatter information for all phase conditions of both modulated and unmodulated backscatter signals is described. The device utilizes taps along coaxial transmission lines, strip transmission line, and waveguides which are spaced by 1/8 wavelength or 1/6 wavelength, etc. This greatly reduces costs by eliminating separate transmission and reception antennas and an expensive arrangement of power splitters and mixers utilized in the prior art.

  14. Critical Thinking.

    ERIC Educational Resources Information Center

    Callison, Daniel

    1998-01-01

    Distinguishes between critical and creative thinking and discusses critical-thinking in relation to modern instructional programs and information literacy. Outlines goals in critical-thinking curriculum, critical thinking skills (student disposition, interpretation, analysis, evaluation, inference, presenting argument, and reflection), and…

  15. Requirements for high-temperature air-cooled central receivers

    SciTech Connect

    Wright, J.D.; Copeland, R.J.

    1983-12-01

    The design of solar thermal central receivers will be shaped by the end user's need for energy. This paper identifies the requirements for receivers supplying heat for industrial processes or electric power generation in the temperature range 540 to 1000/sup 0/C and evaluates the effects of the requirements on air-cooled central receivers. Potential IPH applications are identified as large baseload users that are located some distance from the receiver. In the electric power application, the receiver must supply heat to a pressurized gas power cycle. The difficulty in providing cost-effective thermal transport and thermal storage for air-cooled receivers is a critical problem.

  16. What Is Strong Correlation?

    ERIC Educational Resources Information Center

    Kozak, Marcin

    2009-01-01

    Interpretation of correlation is often based on rules of thumb in which some boundary values are given to help decide whether correlation is non-important, weak, strong or very strong. This article shows that such rules of thumb may do more harm than good, and instead of supporting interpretation of correlation--which is their aim--they teach a…

  17. Strong Navajo Marriages

    ERIC Educational Resources Information Center

    Skogrand, Linda; Mueller, Mary Lou; Arrington, Rachel; LeBlanc, Heidi; Spotted Elk, Davina; Dayzie, Irene; Rosenbrand, Reva

    2008-01-01

    The purpose of this qualitative study, conducted in two Navajo Nation chapters, was to learn what makes Navajo marriages strong because no research has been done on this topic. Twenty-one Navajo couples (42 individuals) who felt they had strong marriages volunteered to participate in the study. Couples identified the following marital strengths:…

  18. LANL receiver system development

    SciTech Connect

    Laubscher, B.; Cooke, B.; Cafferty, M.; Olivas, N.

    1997-08-01

    The CALIOPE receiver system development at LANL is the story of two technologies. The first of these technologies consists of off-the-shelf mercury-cadmium-telluride (MCT) detectors and amplifiers. The vendor for this system is Kolmar Technologies. This system was fielded in the Tan Trailer I (TTI) in 1995 and will be referred to in this paper as GEN I. The second system consists of a MCT detector procured from Santa Barbara Research Center (SBRC) and an amplifier designed and built by LANL. This system was fielded in the Tan Trailer II (TTII) system at the NTS tests in 1996 and will be referred to as GEN II. The LANL CALIOPE experimental plan for 1996 was to improve the lidar system by progressing to a higher rep rate laser to perform many shots in a much shorter period of time. In keeping with this plan, the receiver team set a goal of developing a detector system that was background limited for the projected 100 nanosecond (ns) laser pulse. A set of detailed simulations of the DIAL lidar experiment was performed. From these runs, parameters such as optimal detector size, field of view of the receiver system, nominal laser return power, etc. were extracted. With this information, detector physics and amplifier electronic models were developed to obtain the required specifications for each of these components. These derived specs indicated that a substantial improvement over commercially available, off-the-shelf, amplifier and detector technologies would be needed to obtain the goals. To determine if the original GEN I detector was usable, the authors performed tests on a 100 micron square detector at cryogenic temperatures. The results of this test and others convinced them that an advanced detector was required. Eventually, a suitable detector was identified and a number of these single element detectors were procured from SBRC. These single element detectors were witness for the detector arrays built for another DOE project.

  19. Ultra-wideband receiver

    DOEpatents

    McEwan, Thomas E.

    1994-01-01

    An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, .+-.UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals.

  20. Ultra-wideband receiver

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, .+-.UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals.

  1. Ultra-wideband receiver

    DOEpatents

    McEwan, T.E.

    1996-06-04

    An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, {+-}UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals. 21 figs.

  2. Ultra-wideband receiver

    DOEpatents

    McEwan, T.E.

    1994-09-06

    An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, [+-] UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals. 16 figs.

  3. Terahertz Array Receivers with Integrated Antennas

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Llombart, Nuria; Lee, Choonsup; Jung, Cecile; Lin, Robert; Cooper, Ken B.; Reck, Theodore; Siles, Jose; Schlecht, Erich; Peralta, Alessandro; Thomas, Bertrand; Mehdi, Imran

    2011-01-01

    Highly sensitive terahertz heterodyne receivers have been mostly single-pixel. However, now there is a real need of multi-pixel array receivers at these frequencies driven by the science and instrument requirements. In this paper we explore various receiver font-end and antenna architectures for use in multi-pixel integrated arrays at terahertz frequencies. Development of wafer-level integrated terahertz receiver front-end by using advanced semiconductor fabrication technologies has progressed very well over the past few years. Novel stacking of micro-machined silicon wafers which allows for the 3-dimensional integration of various terahertz receiver components in extremely small packages has made it possible to design multi-pixel heterodyne arrays. One of the critical technologies to achieve fully integrated system is the antenna arrays compatible with the receiver array architecture. In this paper we explore different receiver and antenna architectures for multi-pixel heterodyne and direct detector arrays for various applications such as multi-pixel high resolution spectrometer and imaging radar at terahertz frequencies.

  4. Thinking Critically about Critical Thinking

    ERIC Educational Resources Information Center

    Mulnix, Jennifer Wilson

    2012-01-01

    As a philosophy professor, one of my central goals is to teach students to think critically. However, one difficulty with determining whether critical thinking can be taught, or even measured, is that there is widespread disagreement over what critical thinking actually is. Here, I reflect on several conceptions of critical thinking, subjecting…

  5. Weather Data Receiver

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Northern Video Graphics, Inc. developed a low-cost satellite receiving system for users such as independent meteorologists, agribusiness firms, small airports or flying clubs, marine vessels and small TV stations. Called Video Fax, it is designed for use with certain satellites; the GOES (Geostationary Operational Environmental Satellite) spacecraft operated by the National Oceanic and Atmospheric Administration, the European Space Agency's Meteosat and Japan's Geostationary Meteorological Satellite. By dictum of the World Meteorological Organization, signals from satellites are available to anyone without cost so the Video Fax user can acquire signals directly from the satellite and cut out the middle man, enabling savings. Unit sells for about one-fifth the cost of the equipment used by TV stations. It consists of a two-meter antenna; a receiver; a microprocessor-controlled display computer; and a video monitor. Computer stores data from the satellites and converts it to an image which is displayed on the monitor. Weather map can be preserved as signal data on tape, or it can be stored in a video cassette as a permanent image.

  6. Digital Receiver Phase Meter

    NASA Technical Reports Server (NTRS)

    Marcin, Martin; Abramovici, Alexander

    2008-01-01

    The software of a commercially available digital radio receiver has been modified to make the receiver function as a two-channel low-noise phase meter. This phase meter is a prototype in the continuing development of a phase meter for a system in which radiofrequency (RF) signals in the two channels would be outputs of a spaceborne heterodyne laser interferometer for detecting gravitational waves. The frequencies of the signals could include a common Doppler-shift component of as much as 15 MHz. The phase meter is required to measure the relative phases of the signals in the two channels at a sampling rate of 10 Hz at a root power spectral density <5 microcycle/(Hz)1/2 and to be capable of determining the power spectral density of the phase difference over the frequency range from 1 mHz to 1 Hz. Such a phase meter could also be used on Earth to perform similar measurements in laser metrology of moving bodies. To illustrate part of the principle of operation of the phase meter, the figure includes a simplified block diagram of a basic singlechannel digital receiver. The input RF signal is first fed to the input terminal of an analog-to-digital converter (ADC). To prevent aliasing errors in the ADC, the sampling rate must be at least twice the input signal frequency. The sampling rate of the ADC is governed by a sampling clock, which also drives a digital local oscillator (DLO), which is a direct digital frequency synthesizer. The DLO produces samples of sine and cosine signals at a programmed tuning frequency. The sine and cosine samples are mixed with (that is, multiplied by) the samples from the ADC, then low-pass filtered to obtain in-phase (I) and quadrature (Q) signal components. A digital signal processor (DSP) computes the ratio between the Q and I components, computes the phase of the RF signal (relative to that of the DLO signal) as the arctangent of this ratio, and then averages successive such phase values over a time interval specified by the user.

  7. Living Bones, Strong Bones

    NASA Video Gallery

    In this classroom activity, engineering, nutrition, and physical activity collide when students design and build a healthy bone model of a space explorer which is strong enough to withstand increas...

  8. Solar thermal energy receiver

    NASA Technical Reports Server (NTRS)

    Baker, Karl W. (Inventor); Dustin, Miles O. (Inventor)

    1992-01-01

    A plurality of heat pipes in a shell receive concentrated solar energy and transfer the energy to a heat activated system. To provide for even distribution of the energy despite uneven impingement of solar energy on the heat pipes, absence of solar energy at times, or failure of one or more of the heat pipes, energy storage means are disposed on the heat pipes which extend through a heat pipe thermal coupling means into the heat activated device. To enhance energy transfer to the heat activated device, the heat pipe coupling cavity means may be provided with extensions into the device. For use with a Stirling engine having passages for working gas, heat transfer members may be positioned to contact the gas and the heat pipes. The shell may be divided into sections by transverse walls. To prevent cavity working fluid from collecting in the extensions, a porous body is positioned in the cavity.

  9. Critical Care

    MedlinePlus

    Critical care helps people with life-threatening injuries and illnesses. It might treat problems such as complications from surgery, ... attention by a team of specially-trained health care providers. Critical care usually takes place in an ...

  10. Advanced space solar dynamic receivers

    NASA Technical Reports Server (NTRS)

    Strumpf, Hal J.; Coombs, Murray G.; Lacy, Dovie E.

    1988-01-01

    A study has been conducted to generate and evaluate advanced solar heat receiver concepts suitable for orbital application with Brayton and Stirling engine cycles in the 7-kW size range. The generated receiver designs have thermal storage capability (to enable power production during the substantial eclipse period which accompanies typical orbits) and are lighter and smaller than state-of-the-art systems, such as the Brayton solar receiver being designed and developed by AiResearch for the NASA Space Station. Two receiver concepts have been developed in detail: a packed bed receiver and a heat pipe receiver. The packed bed receiver is appropriate for a Brayton engine; the heat pipe receiver is applicable for either a Brayton or Stirling engine. The thermal storage for both concepts is provided by the melting and freezing of a salt. Both receiver concepts offer substantial improvements in size and weight compared to baseline receivers.

  11. On Strong Anticipation

    PubMed Central

    Stepp, N.; Turvey, M. T.

    2009-01-01

    We examine Dubois's (2003) distinction between weak anticipation and strong anticipation. Anticipation is weak if it arises from a model of the system via internal simulations. Anticipation is strong if it arises from the system itself via lawful regularities embedded in the system's ordinary mode of functioning. The assumption of weak anticipation dominates cognitive science and neuroscience and in particular the study of perception and action. The assumption of strong anticipation, however, seems to be required by anticipation's ubiquity. It is, for example, characteristic of homeostatic processes at the level of the organism, organs, and cells. We develop the formal distinction between strong and weak anticipation by elaboration of anticipating synchronization, a phenomenon arising from time delays in appropriately coupled dynamical systems. The elaboration is conducted in respect to (a) strictly physical systems, (b) the defining features of circadian rhythms, often viewed as paradigmatic of biological behavior based in internal models, (c) Pavlovian learning, and (d) forward models in motor control. We identify the common thread of strongly anticipatory systems and argue for its significance in furthering understanding of notions such as “internal”, “model” and “prediction”. PMID:20191086

  12. Anchorage Receives Record Snowfall

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The forecast called for flurries, but the snow accumulated on the ground in Anchorage, Alaska, at the rate of 2 inches per hour (5 cm per hour) for much of Saturday, March 16, 2002. By the time the winter storm passed on Sunday afternoon, Anchorage had received 28.6 inches (72.6 cm) of snow, surpassing by far the previous record of 15.6 inches (39.6 cm) set on December 29, 1955. Flights were canceled and schools were closed as a result of the storm. This true-color image of Alaska was acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, on March 18. It appears another large, low-pressure system is heading toward the Anchorage region, which could bring substantially more snowfall. The low-pressure system can be identified by the characteristic spiral pattern of clouds located off Alaska's southwestern coast in this scene.

  13. ADMX Receiver and Analysis

    NASA Astrophysics Data System (ADS)

    Malagon, Ana; ADMX Collaboration

    2016-03-01

    ADMX looks for the excess radiation deposited into a cavity from the conversion of a dark matter axion into a microwave photon. The sensitivity of the experiment increases by reducing the background thermal noise and minimizing the electronic noise of the readout system. The axion masses that the experiment can detect are determined by the resonant frequency of the cavity mode of interest, which is tuned using a two rod configuration. One can also increase the search rate by measuring the output from two cavity modes at once, which requires two separate readout schemes. I will discuss the ADMX dual-channel receiver which has been upgraded to have near quantum-limited sensitivity on both channels, and describe how the correct modes are verified, using simulations, in the presence of dense electromagnetic structure. I conclude by describing upgrades to the ADMX analysis which allow for real-time exclusion limits. Supported by DOE Grants DE-FG02-97ER41029, DE-FG02-96ER40956, DE- AC52-07NA27344, DE-AC03-76SF00098, and the Livermore LDRD program.

  14. Strong acoustic wave action

    NASA Astrophysics Data System (ADS)

    Gokhberg, M. B.

    1983-07-01

    Experiments devoted to acoustic action on the atmosphere-magnetosphere-ionosphere system using ground based strong explosions are reviewed. The propagation of acoustic waves was observed by ground observations over 2000 km in horizontal direction and to an altitude of 200 km. Magnetic variations up to 100 nT were detected by ARIEL-3 satellite near the epicenter of the explosion connected with the formation of strong field aligned currents in the magnetosphere. The enhancement of VLF emission at 800 km altitude is observed.

  15. Critical Thoughts on Critical Thinking

    ERIC Educational Resources Information Center

    Cody, Dean E.

    2006-01-01

    Scholars in many academic areas, including librarians, devote a significant amount of thought to critical thinking. Surveying views of its use and possibility, the author considers some key librarians' thoughts on critical thinking. In conclusion, the inability to define critical thinking means that librarians need to emphasize control of…

  16. Critical Thinking vs. Critical Consciousness

    ERIC Educational Resources Information Center

    Doughty, Howard A.

    2006-01-01

    This article explores four kinds of critical thinking. The first is found in Socratic dialogues, which employ critical thinking mainly to reveal logical fallacies in common opinions, thus cleansing superior minds of error and leaving philosophers free to contemplate universal verities. The second is critical interpretation (hermeneutics) which…

  17. Critically Thinking about Critical Thinking

    ERIC Educational Resources Information Center

    Weissberg, Robert

    2013-01-01

    In this article, the author states that "critical thinking" has mesmerized academics across the political spectrum and that even high school students are now being called upon to "think critically." He furthers adds that it is no exaggeration to say that "critical thinking" has quickly evolved into a scholarly…

  18. How Critical Is Critical Thinking?

    ERIC Educational Resources Information Center

    Shaw, Ryan D.

    2014-01-01

    Recent educational discourse is full of references to the value of critical thinking as a 21st-century skill. In music education, critical thinking has been discussed in relation to problem solving and music listening, and some researchers suggest that training in critical thinking can improve students' responses to music. But what exactly is…

  19. A strong comeback

    SciTech Connect

    Marier, D.

    1992-03-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders.

  20. Strong Little Magnets

    ERIC Educational Resources Information Center

    Moloney, Michael J.

    2007-01-01

    Did you know that some strong little cylindrical magnets available in local hardware stores can have an effective circumferential current of 2500 A? This intriguing information can be obtained by hanging a pair of magnets at the center of a coil, as shown in Fig. 1, and measuring the oscillation frequency as a function of coil current.

  1. Strong enhancement of s -wave superconductivity near a quantum critical point of Ca3Ir4Sn13

    SciTech Connect

    Biswas, P. K.; Guguchia, Z.; Khasanov, R.; Chinotti, M.; Li, L.; Wang, Kefeng; Petrovic, C.; Morenzoni, E.

    2015-11-11

    We report microscopic studies by muon spin rotation/relaxation as a function of pressure of the Ca3Ir4Sn13 and Sr3Ir4Sn13 system displaying superconductivity and a structural phase transition associated with the formation of a charge density wave (CDW). Our findings show a strong enhancement of the superfluid density and a dramatic increase of the pairing strength above a pressure of ≈ 1.6 GPa giving direct evidence of the presence of a quantum critical point separating a superconducting phase coexisting with CDW from a pure superconducting phase. The superconducting order parameter in both phases has the same s-wave symmetry. In spite of the conventional phonon-mediated BCS character of the weakly correlated (Ca1-xSrx)3Ir4Sn13 system the dependence of the effective superfluid density on the critical temperature puts this compound in the “Uemura” plot close to unconventional superconductors. This system exemplifies that conventional BCS superconductors in the presence of competing orders or multi-band structure can also display characteristics of unconventional superconductors.

  2. [Fish oil containing lipid emulsions in critically ill patients: Critical analysis and future perspectives].

    PubMed

    Manzanares, W; Langlois, P L

    2016-01-01

    Third-generation lipid emulsions (LE) are soybean oil sparing strategies with immunomodulatory and antiinflammatory effects. Current evidence supporting the use of intravenous (i.v) fish oil (FO) LE in critically ill patients requiring parenteral nutrition or receiving enteral nutrition (pharmaconutrient strategy) mainly derives from small phase ii clinical trials in heterogenous intensive care unit patient's population. Over the last three years, there have been published different systematic reviews and meta-analyses evaluating the effects of FO containing LE in the critically ill. Recently, it has been demonstrated that i.v FO based LE may be able to significantly reduce the incidence of infections as well as mechanical ventilation days and hospital length of stay. Nonetheless, more robust evidence is required before giving a definitive recommendation. Finally, we strongly believe that a dosing study is required before new phase iii clinical trials comparing i.v FO containing emulsions versus other soybean oil strategies can be conducted. PMID:26403991

  3. Critical Care

    MedlinePlus

    Critical care helps people with life-threatening injuries and illnesses. It might treat problems such as complications from surgery, accidents, infections, and severe breathing problems. It involves ...

  4. Criticality Model

    SciTech Connect

    A. Alsaed

    2004-09-14

    The ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, ''Models'', in that they are procedural, rather than mathematical. These model reports document the detailed methodology necessary to implement the approach presented in the Disposal Criticality Analysis Methodology Topical Report and provide calculations utilizing the methodology. Thus, the governing procedure for this type of report is AP-3.12Q, ''Design Calculations and Analyses''. The ''Criticality Model'' is of this latter type, providing a process evaluating the criticality potential of in-package and external configurations. The purpose of this analysis is to layout the process for calculating the criticality potential for various in-package and external configurations and to calculate lower-bound tolerance limit (LBTL) values and determine range of applicability (ROA) parameters. The LBTL calculations and the ROA determinations are performed using selected benchmark experiments that are applicable to various waste forms and various in-package and external configurations. The waste forms considered in this calculation are pressurized water reactor (PWR), boiling water reactor (BWR), Fast Flux Test Facility (FFTF), Training Research Isotope General Atomic (TRIGA), Enrico Fermi, Shippingport pressurized water reactor, Shippingport light water breeder reactor (LWBR), N-Reactor, Melt and Dilute, and Fort Saint Vrain Reactor spent nuclear fuel (SNF). The scope of this analysis is to document the criticality computational method. The criticality

  5. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2007-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  6. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2006-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  7. Children's Expectancy of Criticism for Classroom Achievement Efforts.

    ERIC Educational Resources Information Center

    Potter, Ellen F.

    An expectancy of criticism scale was devised in order to measure children's expectations of giving criticism to and receiving criticism from different agents for public achievement efforts in class. Scores on the Children's Social Desirability Scale (CSD) and teacher ratings of amount of criticism the children received and of their participation…

  8. High temperature solar thermal receiver

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A design concept for a high temperature solar thermal receiver to operate at 3 atmospheres pressure and 2500 F outlet was developed. The performance and complexity of windowed matrix, tube-header, and extended surface receivers were evaluated. The windowed matrix receiver proved to offer substantial cost and performance benefits. An efficient and cost effective hardware design was evaluated for a receiver which can be readily interfaced to fuel and chemical processes or to heat engines for power generation.

  9. High-temperature ceramic receivers

    SciTech Connect

    Jarvinen, P. O.

    1980-01-01

    An advanced ceramic dome cavity receiver is discussed which heats pressurized gas to temperatures above 1800/sup 0/F (1000/sup 0/C) for use in solar Brayton power systems of the dispersed receiver/dish or central receiver type. Optical, heat transfer, structural, and ceramic material design aspects of the receiver are reported and the development and experimental demonstration of a high-temperature seal between the pressurized gas and the high-temperature silicon carbide dome material is described.

  10. Strong subadditivity and holography

    NASA Astrophysics Data System (ADS)

    Prudenziati, Andrea

    2016-05-01

    We study in detail the relationship between strong subadditivity for a boundary field theory and energy conditions for its bulk dual in 2 +1 dimensions. We provide a discussion of known facts and new results organized from the simplest case of a static system with collinear intervals to a time-dependent one in a generic configuration, with particular focus on the holographic geometric description.

  11. Receiving signals of any polarization

    NASA Technical Reports Server (NTRS)

    Ohlson, J. E.; Seidel, B. L.; Stelzried, C. H.

    1981-01-01

    Two-channel detection accomodates linear, circular, and elliptical polarization in one receiving unit. Receiver employs orthomode transducer which breaks any type signal into one left and one right circular component. These are processed in separate receiver channels with equal time-delay, and then recombined for data extraction. System eliminates losses due to polarization mismatch.

  12. Plasmons in strong superconductors

    SciTech Connect

    Baldo, M.; Ducoin, C.

    2011-10-15

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T{sub c} superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  13. Critical Muralism

    ERIC Educational Resources Information Center

    Rosette, Arturo

    2009-01-01

    This study focuses on the development and practices of Critical Muralists--community-educator-artist-leader-activists--and situates these specifically in relation to the Mexican mural tradition of los Tres Grandes and in relation to the history of public art more generally. The study examines how Critical Muralists address artistic and…

  14. Reflux solar receiver design considerations

    NASA Astrophysics Data System (ADS)

    Diver, R. B.

    Reflux heat-pipe and pool-boiler receivers are being developed to improve upon the performance and life of directly-illuminated tube receiver technology used in previous successful demonstrations of dish-Stirling systems. The design of a reflux receiver involves engineering tradeoffs. In this paper, on-sun performance measurements of the Sandia pool-boiler receiver are compared with results from the reflux receiver thermal analysis model, AEETES. Flux and performance implications of various design options are analyzed and discussed.

  15. Advanced solar thermal receiver technology

    NASA Technical Reports Server (NTRS)

    Kudirka, A. A.; Leibowitz, L. P.

    1980-01-01

    Development of advanced receiver technology for solar thermal receivers designed for electric power generation or for industrial applications, such as fuels and chemical production or industrial process heat, is described. The development of this technology is focused on receivers that operate from 1000 F to 3000 F and above. Development strategy is mapped in terms of application requirements, and the related system and technical requirements. Receiver performance requirements and current development efforts are covered for five classes of receiver applications: high temperature, advanced Brayton, Stirling, and Rankine cycle engines, and fuels and chemicals.

  16. Paranal Receives New Mirror

    NASA Astrophysics Data System (ADS)

    2008-04-01

    A 4.1-metre diameter primary mirror, a vital part of the world's newest and fastest survey telescope, VISTA (the Visible and Infrared Survey Telescope for Astronomy) has been delivered to its new mountaintop home at Cerro Paranal, Chile. The mirror will now be coupled with a small camera for initial testing prior to installing the main camera in June. Full scientific operations are due to start early next year. VISTA will form part of ESO's Very Large Telescope facility. ESO PR Photo 10d/08 ESO PR Photo 10d/08 The VISTA Mirror The mirror arrived over the Easter weekend at the Paranal Observatory where the telescope is being assembled at an altitude of 2518m, in Chile's Atacama Desert. VISTA Project Manager Alistair McPherson from STFC's UK Astronomy Technology Centre (UK ATC) accompanied the mirror on its journey to Chile: "This is a major milestone for the VISTA project. The precious mirror was loaded on to a plane in a special cradle that used tennis balls to cushion it from impact for its arduous journey across three continents. " "The mirror had a difficult four-day journey, by air and by road. It arrived in perfect condition and now that it has been coated, we will install the mirror in the telescope with a small test camera for about four weeks testing. We plan to install the main camera in June," said the Project Scientist on VISTA, Will Sutherland of Queen Mary, University of London, UK. The VISTA 4.1-metre diameter primary mirror is the most strongly curved large mirror ever polished to such a precise and exacting surface accuracy - deviations from a perfect surface of less than 1/3000th of the thickness of a human hair. On arrival at Cerro Paranal it was safely craned into the telescope dome where it was washed and coated with a thin layer of protected silver in the facility's coating plant. Silver is the best metal for the purpose since it reflects over 98% of near-infrared light, better than the more commonly used aluminium. To date, the reflectivity

  17. Bragg-cell receiver study

    NASA Technical Reports Server (NTRS)

    Wilson, Lonnie A.

    1987-01-01

    Bragg-cell receivers are employed in specialized Electronic Warfare (EW) applications for the measurement of frequency. Bragg-cell receiver characteristics are fully characterized for simple RF emitter signals. This receiver is early in its development cycle when compared to the IFM receiver. Functional mathematical models are derived and presented in this report for the Bragg-cell receiver. Theoretical analysis is presented and digital computer signal processing results are presented for the Bragg-cell receiver. Probability density function analysis are performed for output frequency. Probability density function distributions are observed to depart from assumed distributions for wideband and complex RF signals. This analysis is significant for high resolution and fine grain EW Bragg-cell receiver systems.

  18. RFI receiver. [deep space network

    NASA Technical Reports Server (NTRS)

    Lay, R.

    1980-01-01

    An S-band radio frequency interference (RFI) receiver to analyze and identify sources of RFI problems in the Deep Space Network DSN tracking stations is described. The RFI receiver is a constant gain, double conversion, open loop receiver with dual sine/cosine channel outputs, providing a total of 20 MHZ monitoring capability. This receiver is computer controlled using a MODCOMP II miniprocessor. The RFI receiver has been designed to operate at a 150 Kelvin system noise temperature accomplished by cascading two low noise field effect transistor (FET) amplifiers for the receiver front-end. The first stage low noise FET amplifier is mounted at the feed horn to minimize any cable losses to achieve a lower system noise temperature. The receiver is tunable over the frequency range of 2150 to 2450 MHz in both sine/cosine output channels with a resolution of 100 kHz.

  19. Performance testing of lidar receivers

    NASA Technical Reports Server (NTRS)

    Shams, M. Y.

    1986-01-01

    In addition to the considerations about the different types of noise sources, dynamic range, and linearity of a lidar receiver, one requires information about the pulse shape retaining capabilities of the receiver. For this purpose, relatively precise information about the height resolution as well as the recovery time of the receiver, due both to large transients and to fast changes in the received signal, is required. As more and more analog receivers using fast analog to digital converters and transient recorders will be used in the future lidar systems, methods to test these devices are essential. The method proposed for this purpose is shown. Tests were carried out using LCW-10, LT-20, and FTVR-2 as optical parts of the optical pulse generator circuits. A commercial optical receiver, LNOR, and a transient recorder, VK 220-4, were parts of the receiver system.

  20. EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Ronning, Filip; Batista, Cristian

    2011-03-01

    Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed

  1. Critics and Criticism of Education

    ERIC Educational Resources Information Center

    Ornstein, Allan C.

    1977-01-01

    Radical educational critics, such as Edgar Friedenberg, Paul Goodman, A. S. Neill, John Holt, Jonathan Kozol, Herbert Kohl, James Herndon, and Ivan Illich, have few constructive goals, no strategy for broad change, and a disdain for modernization and compromise. Additionally, these critics, says the author, fail to consider social factors related…

  2. Strongly correlated electronic materials

    SciTech Connect

    Bedell, K.; Albers, R.; Balatsky, A.; Bishop, A.; Bonca, J.; Gubernatis, J.; Gulasci, M.; Silver, R.; Trugman, S.

    1996-04-01

    This is the final report of a 3-year project. Novel electronic materials characterized by strong electronic correlations display a number of unexpected, often extraordinary, properties. These are likely to play a major role in purpose-specific high-technology electronic materials of the future developed for electronic, magnetic, and optical applications. This project sought to develop predictive control of the novel properties by formulating, solving and applying many-body models for the underlying microscopic physics. This predictive control required the development of new analytical and numerical many-body techniques and strategies for materials of varying strengths of interactions, dimensionality and geometry. Results are compared with experiment on classes of novel materials, and the robust techniques are used to predict additional properties and motivate key additional experiments.

  3. Strong, Lightweight, Porous Materials

    NASA Technical Reports Server (NTRS)

    Leventis, Nicholas; Meador, Mary Ann B.; Johnston, James C.; Fabrizio, Eve F.; Ilhan, Ulvi

    2007-01-01

    A new class of strong, lightweight, porous materials has been invented as an outgrowth of an effort to develop reinforced silica aerogels. The new material, called X-Aerogel is less hygroscopic, but no less porous and of similar density to the corresponding unmodified aerogels. However, the property that sets X-Aerogels apart is their mechanical strength, which can be as much as two and a half orders of magnitude stronger that the unmodified aerogels. X-Aerogels are envisioned to be useful for making extremely lightweight, thermally insulating, structural components, but they may also have applications as electrical insulators, components of laminates, catalyst supports, templates for electrode materials, fuel-cell components, and filter membranes.

  4. Strongly-correlated heterostructures

    SciTech Connect

    Okamoto, Satoshi

    2012-01-01

    Electronic phase behavior in correlated-electron systems is a fundamental problem of condensed matter physics. The change in the phase behavior near surfaces and interfaces, i.e., {\\em electronic reconstruction}, is therefore the fundamental issue of the correlated-electron surface or interface science. In addition to basic science, understanding of such a phase behavior is of crucial importance for potential devices exploiting the novel properties of the correlated systems. In this article, we present a general overview of the field, and then discuss the recent theoretical progress mainly focusing on the correlation effects. We illustrate the general concept of {\\em electronic reconstruction} by studying model heterostructures consisting of strongly-correlated systems. Future directions for research are also discussed.

  5. Immigration: perspectives from receiving countries.

    PubMed

    Weiner, M

    1990-01-01

    The author examines the issue of international migration from the standpoint of receiving countries. He attempts "to understand how and why migrant-receiving countries respond as they do, and to suggest some of the new issues in international migration that arise in a world in which the supply of would-be migrants and refugees is now greater than receiving countries are willing to accept." PMID:12283227

  6. Galileons and strong gravity

    SciTech Connect

    Chagoya, Javier; Koyama, Kazuya; Niz, Gustavo; Tasinato, Gianmassimo E-mail: kazuya.koyama@port.ac.uk E-mail: gianmassimo.tasinato@port.ac.uk

    2014-10-01

    In the context of a cubic Galileon model in which the Vainshtein mechanism suppresses the scalar field interactions with matter, we study low-density stars with slow rotation and static relativistic stars. We develop an expansion scheme to find approximated solutions inside the Vainshtein radius, and show that deviations from General Relativity (GR), while considering rotation, are also suppressed by the Vainshtein mechanism. In a quadratic coupling model, in which the scalarisation effect can significantly enhance deviations from GR in normal scalar tensor gravity, the Galileon term successfully suppresses the large deviations away from GR. Moreover, using a realistic equation of state, we construct solutions for a relativistic star, and show that deviations from GR are more suppressed for higher density objects. However, we found that the scalar field solution ceases to exist above a critical density, which roughly corresponds to the maximum mass of a neutron star. This indicates that, for a compact object described by a polytropic equation of state, the configuration that would collapse into a black hole cannot support a non-trivial scalar field.

  7. Criticism of News Media in City Magazines.

    ERIC Educational Resources Information Center

    Burd, Gene; Young, C. Dianne

    A survey of 80 city and regional magazines was undertaken to examine articles of media criticism. Of those, 78.5% responded. A total of 420 articles were received and were divided according to subject and geographical distribution. A critical analysis of representative articles determined that they represented significant criticism as defined in…

  8. Strongly correlated surface states

    NASA Astrophysics Data System (ADS)

    Alexandrov, Victor A.

    Everything has an edge. However trivial, this phrase has dominated theoretical condensed matter in the past half a decade. Prior to that, questions involving the edge considered to be more of an engineering problem rather than a one of fundamental science: it seemed self-evident that every edge is different. However, recent advances proved that many surface properties enjoy a certain universality, and moreover, are 'topologically' protected. In this thesis I discuss a selected range of problems that bring together topological properties of surface states and strong interactions. Strong interactions alone can lead to a wide spectrum of emergent phenomena: from high temperature superconductivity to unconventional magnetic ordering; interactions can change the properties of particles, from heavy electrons to fractional charges. It is a unique challenge to bring these two topics together. The thesis begins by describing a family of methods and models with interactions so high that electrons effectively disappear as particles and new bound states arise. By invoking the AdS/CFT correspondence we can mimic the physical systems of interest as living on the surface of a higher dimensional universe with a black hole. In a specific example we investigate the properties of the surface states and find helical spin structure of emerged particles. The thesis proceeds from helical particles on the surface of black hole to a surface of samarium hexaboride: an f-electron material with localized magnetic moments at every site. Interactions between electrons in the bulk lead to insulating behavior, but the surfaces found to be conducting. This observation motivated an extensive research: weather the origin of conduction is of a topological nature. Among our main results, we confirm theoretically the topological properties of SmB6; introduce a new framework to address similar questions for this type of insulators, called Kondo insulators. Most notably we introduce the idea of Kondo

  9. Foreshocks of strong earthquakes

    NASA Astrophysics Data System (ADS)

    Guglielmi, A. V.; Sobisevich, L. E.; Sobisevich, A. L.; Lavrov, I. P.

    2014-07-01

    The specific enhancement of ultra-low-frequency (ULF) electromagnetic oscillations a few hours prior to the strong earthquakes, which was previously mentioned in the literature, motivated us to search for the distinctive features of the mechanical (foreshock) activity of the Earth's crust in the epicentral zones of the future earthquakes. Activation of the foreshocks three hours before the main shock is revealed, which is roughly similar to the enhancement of the specific electromagnetic ULF emission. It is hypothesized that the round-the-world seismic echo signals from the earthquakes, which form the peak of energy release 2 h 50 min before the main events, act as the triggers of the main shocks due to the cumulative action of the surface waves converging to the epicenter. It is established that the frequency of the fluctuations in the foreshock activity decreases at the final stages of the preparation of the main shocks, which probably testifies to the so-called mode softening at the approach of the failure point according to the catastrophe theory.

  10. Strong-interaction nonuniversality

    SciTech Connect

    Volkas, R. R.; Foot, R.; He, X.; Joshi, G. C.

    1989-07-01

    The universal QCD color theory is extended to an SU(3)/sub 1//direct product/SU(3)/sub 2//direct product/SU(3)/sub 3/ gauge theory, where quarks of the /ital i/th generation transform as triplets under SU(3)/sub /ital i// and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements.

  11. Kinematics of Strong Discontinuities

    NASA Technical Reports Server (NTRS)

    Peterson, K.; Nguyen, G.; Sulsky, D.

    2006-01-01

    Synthetic Aperture Radar (SAR) provides a detailed view of the Arctic ice cover. When processed with the RADARSAT Geophysical Processor System (RGPS), it provides estimates of sea ice motion and deformation over large regions of the Arctic for extended periods of time. The deformation is dominated by the appearance of linear kinematic features that have been associated with the presence of leads. The RGPS deformation products are based on the assumption that the displacement and velocity are smooth functions of the spatial coordinates. However, if the dominant deformation of multiyear ice results from the opening, closing and shearing of leads, then the displacement and velocity can be discontinuous. This presentation discusses the kinematics associated with strong discontinuities that describe possible jumps in displacement or velocity. Ice motion from SAR data are analyzed using this framework. It is assumed that RGPS cells deform due to the presence of a lead. The lead orientation is calculated to optimally account for the observed deformation. It is shown that almost all observed deformation can be represented by lead opening and shearing. The procedure used to reprocess motion data to account for leads will be described and applied to regions of the Beaufort Sea. The procedure not only provides a new view of ice deformation, it can be used to obtain information about the presence of leads for initialization and/or validation of numerical simulations.

  12. UWB delay and multiply receiver

    DOEpatents

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  13. Morphogenesis at criticality?

    NASA Astrophysics Data System (ADS)

    Krotov, Dmitry; Dubuis, Julien; Gregor, Thomas; Bialek, William

    2014-03-01

    Spatial patterns in the early fruit fly embryo emerge from a network of interactions among transcription factors, the gap genes, driven by maternal inputs. Such networks can exhibit many qualitatively different behaviors, separated by critical surfaces. At criticality, we should observe strong correlations in the fluctuations of different genes around their mean expression levels, a slowing of the dynamics along some but not all directions in the space of possible expression levels, correlations of expression fluctuations over long distances in the embryo, and departures from a Gaussian distribution of these fluctuations. Analysis of recent experiments on the gap genes shows that all these signatures are observed, and that the different signatures are related in ways predicted by theory. While there might be other explanations for these individual phenomena, the confluence of evidence suggests that this genetic network is tuned to criticality.

  14. Morphogenesis at criticality

    PubMed Central

    Krotov, Dmitry; Dubuis, Julien O.; Gregor, Thomas; Bialek, William

    2014-01-01

    Spatial patterns in the early fruit fly embryo emerge from a network of interactions among transcription factors, the gap genes, driven by maternal inputs. Such networks can exhibit many qualitatively different behaviors, separated by critical surfaces. At criticality, we should observe strong correlations in the fluctuations of different genes around their mean expression levels, a slowing of the dynamics along some but not all directions in the space of possible expression levels, correlations of expression fluctuations over long distances in the embryo, and departures from a Gaussian distribution of these fluctuations. Analysis of recent experiments on the gap gene network shows that all these signatures are observed, and that the different signatures are related in ways predicted by theory. Although there might be other explanations for these individual phenomena, the confluence of evidence suggests that this genetic network is tuned to criticality. PMID:24516161

  15. Crossover from polariton lasing to exciton lasing in a strongly coupled ZnO microcavity

    NASA Astrophysics Data System (ADS)

    Lai, Ying-Yu; Chou, Yu-Hsun; Lan, Yu-Pin; Lu, Tien-Chang; Wang, Shing-Chung; Yamamoto, Yoshihisa

    2016-02-01

    Unlike conventional photon lasing, in which the threshold is limited by the population inversion of the electron-hole plasma, the exciton lasing generated by exciton-exciton scattering and the polariton lasing generated by dynamical condensates have received considerable attention in recent years because of the sub-Mott density and low-threshold operation. This paper presents a novel approach to generate both exciton and polariton lasing in a strongly coupled microcavity (MC) and determine the critical driving requirements for simultaneously triggering these two lasing operation in temperature <140 K and large negative polariton-exciton offset (<-133 meV) conditions. In addition, the corresponding lasing behaviors, such as threshold energy, linewidth, phase diagram, and angular dispersion are verified. The results afford a basis from which to understand the complicated lasing mechanisms in strongly coupled MCs and verify a new method with which to trigger dual laser emission based on exciton and polariton.

  16. Crossover from polariton lasing to exciton lasing in a strongly coupled ZnO microcavity

    PubMed Central

    Lai, Ying-Yu; Chou, Yu-Hsun; Lan, Yu-Pin; Lu, Tien-Chang; Wang, Shing-Chung; Yamamoto, Yoshihisa

    2016-01-01

    Unlike conventional photon lasing, in which the threshold is limited by the population inversion of the electron-hole plasma, the exciton lasing generated by exciton-exciton scattering and the polariton lasing generated by dynamical condensates have received considerable attention in recent years because of the sub-Mott density and low-threshold operation. This paper presents a novel approach to generate both exciton and polariton lasing in a strongly coupled microcavity (MC) and determine the critical driving requirements for simultaneously triggering these two lasing operation in temperature <140 K and large negative polariton-exciton offset (<−133 meV) conditions. In addition, the corresponding lasing behaviors, such as threshold energy, linewidth, phase diagram, and angular dispersion are verified. The results afford a basis from which to understand the complicated lasing mechanisms in strongly coupled MCs and verify a new method with which to trigger dual laser emission based on exciton and polariton. PMID:26838665

  17. Customizable Digital Receivers for Radar

    NASA Technical Reports Server (NTRS)

    Moller, Delwyn; Heavey, Brandon; Sadowy, Gregory

    2008-01-01

    Compact, highly customizable digital receivers are being developed for the system described in 'Radar Interferometer for Topographic Mapping of Glaciers and Ice Sheets' (NPO-43962), NASA Tech Briefs, Vol. 31, No. 7 (August 2007), page 72. The receivers are required to operate in unison, sampling radar returns received by the antenna elements in a digital beam-forming (DBF) mode. The design of these receivers could also be adapted to commercial radar systems. At the time of reporting the information for this article, there were no commercially available digital receivers capable of satisfying all of the operational requirements and compact enough to be mounted directly on the antenna elements. A provided figure depicts the overall system of which the digital receivers are parts. Each digital receiver includes an analog-to-digital converter (ADC), a demultiplexer (DMUX), and a field-programmable gate array (FPGA). The ADC effects 10-bit band-pass sampling of input signals having frequencies up to 3.5 GHz. The input samples are demultiplexed at a user-selectable rate of 1:2 or 1:4, then buffered in part of the FPGA that functions as a first-in/first-out (FIFO) memory. Another part of the FPGA serves as a controller for the ADC, DMUX, and FIFO memory and as an interface between (1) the rest of the receiver and (2) a front-panel data port (FPDP) bus, which is an industry-standard parallel data bus that has a high data-rate capability and multichannel configuration suitable for DBF. Still other parts of the FPGA in each receiver perform signal-processing functions. The digital receivers can be configured to operate in a stand-alone mode, or in a multichannel mode as needed for DBF. The customizability of the receiver makes it applicable to a broad range of system architectures. The capability for operation of receivers in either a stand-alone or a DBF mode enables the use of the receivers in an unprecedentedly wide variety of radar systems.

  18. Critical Thinking

    ERIC Educational Resources Information Center

    Villano, Matt

    2006-01-01

    True excellence in technology implementation emerges when IT, administrative, and academic leaders link IT to mission-critical institutional objectives, investing in hardware and software to serve an explicit purpose and a distinct population of users. This article illustrates that at public institutions of higher education in New Hampshire as…

  19. PREFACE: Strongly correlated electron systems Strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Saxena, Siddharth S.; Littlewood, P. B.

    2012-07-01

    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

  20. A GPS Receiver for Lunar Missions

    NASA Technical Reports Server (NTRS)

    Bamford, William A.; Heckler, Gregory W.; Holt, Greg N.; Moreau, Michael C.

    2008-01-01

    Beginning with the launch of the Lunar Reconnaissance Orbiter (LRO) in October of 2008, NASA will once again begin its quest to land humans on the Moon. This effort will require the development of new spacecraft which will safely transport people from the Earth to the Moon and back again, as well as robotic probes tagged with science, re-supply, and communication duties. In addition to the next-generation spacecraft currently under construction, including the Orion capsule, NASA is also investigating and developing cutting edge navigation sensors which will allow for autonomous state estimation in low Earth orbit (LEO) and cislunar space. Such instruments could provide an extra layer of redundancy in avionics systems and reduce the reliance on support and on the Deep Space Network (DSN). One such sensor is the weak-signal Global Positioning System (GPS) receiver "Navigator" being developed at NASA's Goddard Space Flight Center (GSFC). At the heart of the Navigator is a Field Programmable Gate Array (FPGA) based acquisition engine. This engine allows for the rapid acquisition/reacquisition of strong GPS signals, enabling the receiver to quickly recover from outages due to blocked satellites or atmospheric entry. Additionally, the acquisition algorithm provides significantly lower sensitivities than a conventional space-based GPS receiver, permitting it to acquire satellites well above the GPS constellation. This paper assesses the performance of the Navigator receiver based upon three of the major flight regimes of a manned lunar mission: Earth ascent, cislunar navigation, and entry. Representative trajectories for each of these segments were provided by NASA. The Navigator receiver was connected to a Spirent GPS signal generator, to allow for the collection of real-time, hardware-in-the-loop results for each phase of the flight. For each of the flight segments, the Navigator was tested on its ability to acquire and track GPS satellites under the dynamical

  1. Coe Receives 2007 Gilbert Award

    NASA Astrophysics Data System (ADS)

    Bogue, Scott W.; Coe, Robert S.

    2008-05-01

    Robert S. Coe received the 2007 William Gilbert Award at the 2007 AGU Fall Meeting in San Francisco, Calif. The award recognizes outstanding and unselfish work in magnetism of Earth materials and of the Earth and planets.

  2. Streak camera receiver definition study

    NASA Technical Reports Server (NTRS)

    Johnson, C. B.; Hunkler, L. T., Sr.; Letzring, S. A.; Jaanimagi, P.

    1990-01-01

    Detailed streak camera definition studies were made as a first step toward full flight qualification of a dual channel picosecond resolution streak camera receiver for the Geoscience Laser Altimeter and Ranging System (GLRS). The streak camera receiver requirements are discussed as they pertain specifically to the GLRS system, and estimates of the characteristics of the streak camera are given, based upon existing and near-term technological capabilities. Important problem areas are highlighted, and possible corresponding solutions are discussed.

  3. Transient simulation of molten salt central receiver

    NASA Astrophysics Data System (ADS)

    Doupis, Dimitri; Wang, Chuan; Carcorze-Soto, Jorge; Chen, Yen-Ming; Maggi, Andrea; Losito, Matteo; Clark, Michael

    2016-05-01

    Alstom is developing concentrated solar power (CSP) utilizing 60/40wt% NaNO3-KNO3 molten salt as the working fluid in a tower receiver for the global renewable energy market. In the CSP power generation cycle, receivers undergo a daily cyclic operation due to the transient nature of solar energy. Development of robust and efficient start-up and shut-down procedures is critical to avoiding component failures due to mechanical fatigue resulting from thermal transients, thus maintaining the performance and availability of the CSP plant. The Molten Salt Central Receiver (MSCR) is subject to thermal transients during normal daily operation, a cycle that includes warmup, filling, operation, draining, and shutdown. This paper describes a study to leverage dynamic simulation and finite element analysis (FEA) in development of start-up, shutdown, and transient operation concepts for the MSCR. The results of the FEA also verify the robustness of the MSCR design to the thermal transients anticipated during the operation of the plant.

  4. Next generation digital GPS receiver

    NASA Astrophysics Data System (ADS)

    Frank, G. B.; Yakos, Michael D.

    1990-07-01

    The architecture and technology features of the next-generation (NGR) digital GPS receiver manufactured by Collins are described. The project's objective was to develop an advanced GPS receiver chipset with high antijam capabilities. The program, initiated in 1985, has provided the technology for miniature receiver products for both unmanned and manned vehicle applications. A two-channel version of the receiver is currently in full-scale development for tactical missile applications. A five-channel version is being tested and evaluated as a drop-in replacement for RCVR-3A, the US Department of Defense standard high dynamic receiver. The NGR design started with the digital signal processing architecture developed for the Defense Advanced Research Project Agency (DARPA) hand-held GPS receiver. Enhancements were made to improve the antijam and signal acquisition performance. Producible, qualifiable and cost-effective silicon monolithic microwave integrated circuits and semicustom digital technologies were used to develop the core GPS chipset. A system design approach was established to permit reuse of mature and validated GPS software.

  5. Solar dynamic heat receiver technology

    NASA Technical Reports Server (NTRS)

    Sedgwick, Leigh M.

    1991-01-01

    A full-size, solar dynamic heat receiver was designed to meet the requirements specified for electrical power modules on the U.S. Space Station, Freedom. The heat receiver supplies thermal energy to power a heat engine in a closed Brayton cycle using a mixture of helium-xenon gas as the working fluid. The electrical power output of the engine, 25 kW, requires a 100 kW thermal input throughout a 90 minute orbit, including when the spacecraft is eclipsed for up to 36 minutes from the sun. The heat receiver employs an integral thermal energy storage system utilizing the latent heat available through the phase change of a high-temperature salt mixture. A near eutectic mixture of lithium fluoride and calcium difluoride is used as the phase change material. The salt is contained within a felt metal matrix which enhances heat transfer and controls the salt void distribution during solidification. Fabrication of the receiver is complete and it was delivered to NASA for verification testing in a simulated low-Earth-orbit environment. This document reviews the receiver design and describes its fabrication history. The major elements required to operate the receiver during testing are also described.

  6. Imaging the Crustal and Subducted Slab Structure Beneath Puerto Rico Using Receiver Function Analysis

    NASA Astrophysics Data System (ADS)

    Vanacore, E. A.; Lopez, A. M.; Huerfano Moreno, V. A.

    2015-12-01

    The determination of earthquake locations are dependent on the velocity model selected. Consequently, the refinement and updating of the velocity models used at the local and regional network level is a critical component for network efficiency through location accuracy. With the expansion of broadband instruments within the Puerto Rico -Virgin Islands region, updating the velocity model is a current long term goal of the Puerto Rico Seismic Network (PRSN). As a first step to this long term goal, receiver functions of ~20 broadband stations with data between 2010 and 2015 were calculated using iterative time domain deconvolution. The receiver function analysis not only provides insight into the crustal velocity structure but also leads to a better understanding of the region's larger tectonic structure. Preliminary results of the receiver function analysis exhibit evidence of a "slab signal"; the receiver function backazimuth sweeps for some stations particularly on the northern side of the island contain a strong P to S conversion at approximately 7 seconds which likely corresponds to the top of the slab beneath Puerto Rico. This strong slab signal implies that simple 1-D analyses of the data (e.g. H-K stacking) may lead to misleading results. To further understand the crustal structure of PRVI, we employ a 3D common-conversion-point analysis. This analysis yields a Moho beneath the island between 32-42km and a possible southward dipping slab structure between 60-80km depth. Further analysis is needed to determine the 2D or 3D velocity structure of Puerto Rico and the surrounding environs such as waveform modeling. Given the current geometry of the available array, detailed imaging of the slab and mantle wedge beneath Puerto Rico is limited. PRSN is currently seeking to install denser temporary networks to improve local imaging that will help understand the nature of the crust, mantle wedge and slab structure beneath the island as well as the structure's influence

  7. Alerting of Laboratory Critical Values

    NASA Astrophysics Data System (ADS)

    Song, Sang Hoon; Park, Kyoung Un; Song, Junghan; Paik, Hyeon Young; Lee, Chi Woo; Bang, Su Mi; Hong, Joon Seok; Lee, Hyun Joo; Cho, In-Sook; Kim, Jeong Ah; Kim, Hyun-Young; Kim, Yoon

    Critical value is defined as a result suggesting that the patient is in danger unless appropriate action is taken immediately. We designed an automated reporting system of critical values and evaluated its performance. Fifteen critical values were defined and 2-4 doctors were assigned to receive short message service (SMS).Laboratory results in LIS and EMR were called back to the DIA server. The rule engine named U-brain in the CDSS server was run in real-time and decision if the laboratory data was critical was made. The CDSS system for alerting of laboratory critical values was fast and stable without additional burden to the entire EMR system. Continuous communication with clinicians and feedback of clinical performance are mandatory for the refinement and development of user-friendly CDSS contents. Appropriate clinical parameters are necessary for demonstration of the usefulness of the system.

  8. PPM Receiver Implemented in Software

    NASA Technical Reports Server (NTRS)

    Gray, Andrew; Kang, Edward; Lay, Norman; Vilnrotter, Victor; Srinivasan, Meera; Lee, Clement

    2010-01-01

    A computer program has been written as a tool for developing optical pulse-position- modulation (PPM) receivers in which photodetector outputs are fed to analog-to-digital converters (ADCs) and all subsequent signal processing is performed digitally. The program can be used, for example, to simulate an all-digital version of the PPM receiver described in Parallel Processing of Broad-Band PPM Signals (NPO-40711), which appears elsewhere in this issue of NASA Tech Briefs. The program can also be translated into a design for digital PPM receiver hardware. The most notable innovation embodied in the software and the underlying PPM-reception concept is a digital processing subsystem that performs synchronization of PPM time slots, even though the digital processing is, itself, asynchronous in the sense that no attempt is made to synchronize it with the incoming optical signal a priori and there is no feedback to analog signal processing subsystems or ADCs. Functions performed by the software receiver include time-slot synchronization, symbol synchronization, coding preprocessing, and diagnostic functions. The program is written in the MATLAB and Simulink software system. The software receiver is highly parameterized and, hence, programmable: for example, slot- and symbol-synchronization filters have programmable bandwidths.

  9. Receiver-exciter controller design

    NASA Astrophysics Data System (ADS)

    Jansma, P. A.

    1982-06-01

    A description of the general design of both the block 3 and block 4 receiver-exciter controllers for the Deep Space Network (DSN) Mark IV-A System is presented along with the design approach. The controllers are designed to enable the receiver-exciter subsystem (RCV) to be configured, calibrated, initialized and operated from a central location via high level instructions. The RECs are designed to be operated under the control of the DMC subsystem. The instructions are in the form of standard subsystem blocks (SSBs) received via the local area network (LAN). The centralized control provided by RECs and other DSCC controllers in Mark IV-A is intended to reduce DSN operations costs from the Mark III era.

  10. Receiver-exciter controller design

    NASA Technical Reports Server (NTRS)

    Jansma, P. A.

    1982-01-01

    A description of the general design of both the block 3 and block 4 receiver-exciter controllers for the Deep Space Network (DSN) Mark IV-A System is presented along with the design approach. The controllers are designed to enable the receiver-exciter subsystem (RCV) to be configured, calibrated, initialized and operated from a central location via high level instructions. The RECs are designed to be operated under the control of the DMC subsystem. The instructions are in the form of standard subsystem blocks (SSBs) received via the local area network (LAN). The centralized control provided by RECs and other DSCC controllers in Mark IV-A is intended to reduce DSN operations costs from the Mark III era.

  11. UWB communication receiver feedback loop

    DOEpatents

    Spiridon, Alex; Benzel, Dave; Dowla, Farid U.; Nekoogar, Faranak; Rosenbury, Erwin T.

    2007-12-04

    A novel technique and structure that maximizes the extraction of information from reference pulses for UWB-TR receivers is introduced. The scheme efficiently processes an incoming signal to suppress different types of UWB as well as non-UWB interference prior to signal detection. Such a method and system adds a feedback loop mechanism to enhance the signal-to-noise ratio of reference pulses in a conventional TR receiver. Moreover, sampling the second order statistical function such as, for example, the autocorrelation function (ACF) of the received signal and matching it to the ACF samples of the original pulses for each transmitted bit provides a more robust UWB communications method and system in the presence of channel distortions.

  12. Frequency synthesizers for telemetry receivers

    NASA Astrophysics Data System (ADS)

    Stirling, Ronald C.

    1990-07-01

    The design of a frequency synthesizer is presented for telemetry receivers. The synthesizer contains two phase-locked loops, each with a programmable frequency counter, and incorporates fractional frequency synthesis but does not use a phase accumulator. The selected receiver design has a variable reference loop operating as a part of the output loop. Within the synthesizer, a single VTO generates the output frequency that is voltage-tunable from 375-656 MHz. The single-sideband phase noise is measured with an HP 8566B spectrum analyzer, and the receiver's bit error rate (BER) is measured with a carrier frequency of 250 MHz, synthesized LO at 410 MHz, and the conditions of BPSK, NRZ-L, and 2.3 kHz bit rate. The phase noise measurement limits and the BER performance data are presented in tabular form.

  13. Central solar-energy receiver

    DOEpatents

    Not Available

    1981-10-27

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan is described. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  14. Coping with Late-Life Challenges: Development and Validation of the Care-Receiver Efficacy Scale

    ERIC Educational Resources Information Center

    Cox, Enid O.; Green, Kathy E.; Seo, Honglan; Inaba, Miyuki; Quillen, Alicia Alyla

    2006-01-01

    Purpose: Measures are lacking that address the challenges that people think they face in their roles as elderly care receivers. However, the development of a sense of efficacy in this role by mentally competent care receivers is critical to successful partnerships between caregivers and care receivers. The purpose of this article is to report the…

  15. Digital Receiver for Microwave Radiometry

    NASA Technical Reports Server (NTRS)

    Ellingson, Steven W.; Hampson, Grant A.; Johnson, Joel T.

    2005-01-01

    A receiver proposed for use in L-band microwave radiometry (for measuring soil moisture and sea salinity) would utilize digital signal processing to suppress interfering signals. Heretofore, radio frequency interference has made it necessary to limit such radiometry to a frequency band about 20 MHz wide, centered at .1,413 MHz. The suppression of interference in the proposed receiver would make it possible to expand the frequency band to a width of 100 MHz, thereby making it possible to obtain greater sensitivity and accuracy in measuring moisture and salinity

  16. Optical receivers using rough reflectors

    NASA Technical Reports Server (NTRS)

    Vilnrotter, V. A.

    1985-01-01

    This report examines the possible use of rough, or nondiffraction-limited, reflectors for collecting optical signals. It is shown that in the absence of background radiation, the reflector's surface quality has little effect on the performance of a properly designed receiver, but that the presence of even small amounts of background radiation can lead to severe performance degradation. Techniques are suggested for improving receiver performance in high-background environments, and bounds and approximations to the exact error-probability expressions are derived.

  17. The GBT 4mm Receiver

    NASA Astrophysics Data System (ADS)

    Frayer, David T.; White, S.; Watts, G.; Stennes, M.; Maddalena, R. J.; Simon, R.; Pospieszalski, M.; Bryerton, E.

    2013-01-01

    The new 4mm receiver (67--93 GHz) for the Robert C. Byrd Green Bank Telescope (GBT) was built to take advantage of the improved surface accuracy of the dish. The low frequency end of the 3mm atmospheric window is not available with ALMA (<84 GHz), and the sensitivity of the GBT is better than any other facility within this band. We discuss the design and performance of this new receiver for the GBT, and highlight the science opportunities available with the instrument. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  18. A Multinational Study of Thromboprophylaxis Practice in Critically Ill Children*

    PubMed Central

    Faustino, Edward Vincent S.; Hanson, Sheila; Spinella, Philip C.; Tucci, Marisa; O'Brien, Sarah H.; Nunez, Antonio Rodriguez; Yung, Michael; Truemper, Edward; Qin, Li; Li, Simon; Marohn, Kimberly; Randolph, Adrienne G.

    2015-01-01

    Objectives Although critically ill children are at increased risk for developing deep venous thrombosis, there are few pediatric studies establishing the prevalence of thrombosis or the efficacy of thromboprophylaxis. We tested the hypothesis that thromboprophylaxis is infrequently used in critically ill children even for those in whom it is indicated. Design Prospective multinational cross-sectional study over four study dates in 2012. Setting Fifty-nine PICUs in Australia, Canada, New Zealand, Portugal, Singapore, Spain, and the United States. Patients All patients less than 18 years old in the PICU during the study dates and times were included in the study, unless the patients were 1) boarding in the unit waiting for a bed outside the PICU or 2) receiving therapeutic anticoagulation. Interventions None. Measurements and Main Results Of 2,484 children in the study, 2,159 (86.9%) had greater than or equal to 1 risk factor for thrombosis. Only 308 children (12.4%) were receiving pharmacologic thromboprophylaxis (e.g., aspirin, low-molecular-weight heparin, or unfractionated heparin). Of 430 children indicated to receive pharmacologic thromboprophylaxis based on consensus recommendations, only 149 (34.7%) were receiving it. Mechanical thromboprophylaxis was used in 156 of 655 children (23.8%) 8 years old or older, the youngest age for that device. Using nonlinear mixed effects model, presence of cyanotic congenital heart disease (odds ratio, 7.35; p < 0.001) and spinal cord injury (odds ratio, 8.85; p = 0.008) strongly predicted the use of pharmacologic and mechanical thromboprophylaxis, respectively. Conclusions Thromboprophylaxis is infrequently used in critically ill children. This is true even for children at high risk of thrombosis where consensus guidelines recommend pharmacologic thromboprophylaxis. PMID:24351371

  19. Advances in SIS receiver technology

    NASA Technical Reports Server (NTRS)

    Frerking, M. A.

    1988-01-01

    Significant advances in SIS receiver technology since the last Asilomar meeting include: superconductor materials, integrated inductive tuning elements, and planar mounting structures. The effect of these advances is to push the upper frequency operating limit from about 600 to 1500 GHz, and to enhance the feasibility of focal plane arrays of heterodyne receivers. A fundamental high frequency operating limit of SIS mixers is set by the superconducting energy gap. A practical limitation for high frequency operation of SIS junctions is their parasitic capacitance and resistance. The performance of the mixer will be degraded by the Resistor-Capacitor rolloff. Several designs were reported for inductive elements integrated on the same substrate as the SIS junctions to tune out the bulk junction capacitance. Most millimeter SIS-based heterodyne receivers have used waveguide coupling structures. Technology has advanced to the state where programs that have a high probability of success can be defined to produce arrays of SIS receivers for frequencies as high as 1500 GHz.

  20. Microwave blackbodies for spaceborne receivers

    NASA Technical Reports Server (NTRS)

    Stacey, J. M.

    1985-01-01

    The properties of microwave blackbody targets are explained as they apply to the calibration of spaceborne receivers. Also described are several practicable, blackbody targets used to test and calibrate receivers in the laboratory and in the thermal vacuum chamber. Problems with the precision and the accuracy of blackbody targets, and blackbody target design concepts that overcome some of the accuracy limitations present in existing target designs, are presented. The principle of the Brewster angle blackbody target is described where the blackbody is applied as a fixed-temperature test target in the laboratory and as a variable-temperature target in the thermal vacuum chamber. The reflectivity of a Brewster angle target is measured in the laboratory. From this measurement, the emissivity of the target is calculated. Radiatively cooled thermal suspensions are discussed as the coolants of blackbody targets and waveguide terminations that function as calibration devices in spaceborne receivers. Examples are given for the design of radiatively cooled thermal suspensions. Corrugated-horn antennas used to observe the cosmic background and to provide a cold-calibration source for spaceborne receivers are described.

  1. RFID receiver apparatus and method

    DOEpatents

    Scott, Jeffrey Wayne

    2006-12-26

    An RFID backscatter interrogator for transmitting data to an RFID tag, generating a carrier for the tag, and receiving data from the tag modulated onto the carrier, the interrogator including a single grounded-coplanar wave-guide circuit board and at least one surface mount integrated circuit supported by the circuit board.

  2. Clark Receives Ocean Sciences Award

    NASA Astrophysics Data System (ADS)

    Roman, Michael R.; Clark, H. Lawrence

    2008-09-01

    H. Lawrence Clark received the 2008 Ocean Sciences Award at the 2008 Ocean Sciences Meeting, held 2-7 March 2008 in Orlando, Fla. The award is given in recognition of outstanding and long-standing service to the ocean sciences.

  3. Converting accounts receivable into cash.

    PubMed

    Folk, M D; Roest, P R

    1995-09-01

    In recent years, increasing numbers of healthcare providers have converted their accounts receivable into cash through a process called securitization. This practice has gained popularity because it provides a means to raise capital necessary to healthcare organizations. Although securitization transactions can be complex, they may provide increased financial flexibility to providers as they prepare for continuing change in the healthcare industry. PMID:10145096

  4. CLASSSTRONG: Classical simulations of strong field processes

    NASA Astrophysics Data System (ADS)

    Ciappina, M. F.; Pérez-Hernández, J. A.; Lewenstein, M.

    2014-01-01

    A set of Mathematica functions is presented to model classically two of the most important processes in strong field physics, namely high-order harmonic generation (HHG) and above-threshold ionization (ATI). Our approach is based on the numerical solution of the Newton-Lorentz equation of an electron moving on an electric field and takes advantage of the symbolic languages features and graphical power of Mathematica. Like in the Strong Field Approximation (SFA), the effects of atomic potential on the motion of electron in the laser field are neglected. The SFA was proven to be an essential tool in strong field physics in the sense that it is able to predict with great precision the harmonic (in the HHG) and energy (in the ATI) limits. We have extended substantially the conventional classical simulations, where the electric field is only dependent on time, including spatial nonhomogeneous fields and spatial and temporal synthesized fields. Spatial nonhomogeneous fields appear when metal nanosystems interact with strong and short laser pulses and temporal synthesized fields are routinely generated in attosecond laboratories around the world. Temporal and spatial synthesized fields have received special attention nowadays because they would allow to exceed considerably the conventional harmonic and electron energy frontiers. Classical simulations are an invaluable tool to explore exhaustively the parameters domain at a cheap computational cost, before massive quantum mechanical calculations, absolutely indispensable for the detailed analysis, are performed.

  5. Advanced Stirling receiver development program, phase 1

    NASA Technical Reports Server (NTRS)

    Lurio, Charles A.

    1990-01-01

    Critical technology experiments were designed and developed to evaluate the Stirling cavity heat pipe receiver for a space solar power system. Theoretical criteria were applied to the design of a module for containing energy storage phase change material while avoiding thermal ratcheting. Zero-g drop tower tests, without phase change, were conducted to affirm that the bubble location required to avoid ratcheting could be achieved without the use of container materials that are wetted by the phase change material. A full scale module was fabricated, but not tested. A fabrication method was successfully developed for the sodium evaporator dome, with a sintered screen wick, to be used as the focal point for the receiver. Crushing of the screen during hydroforming was substantially reduced over the results of other researchers by using wax impregnation. Superheating of the sodium in the wick under average flux conditions is expected to be under 10K. A 2000K furnace which will simulate solar flux conditions for testing the evaporator dome was successfully built and tested.

  6. Fractional effective action at strong electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Kleinert, Hagen; Strobel, Eckhard; Xue, She-Sheng

    2013-07-01

    In 1936, Weisskopf [K. Dan. Vidensk. Selsk. Mat. Fys. Medd. XIV (1936)] showed that for vanishing electric or magnetic fields the strong-field behavior of the one-loop Euler-Heisenberg effective Lagrangian of quantum electro dynamics (QED) is logarithmic. Here we generalize this result for different limits of the Lorentz invariants E→2-B→2 and B→·E→. The logarithmic dependence can be interpreted as a lowest-order manifestation of an anomalous power behavior of the effective Lagrangian of QED, with critical exponents δ=e2/(12π) for spinor QED, and δS=δ/4 for scalar QED.

  7. Femtosecond Photon-Counting Receiver

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Rambo, Timothy M.; Yang, Guangning; Lu, Wei; Numata, Kenji

    2016-01-01

    An optical correlation receiver is described that provides ultra-precise distance and/or time-pulse-width measurements even for weak (single photons) and short (femtosecond) optical signals. A new type of optical correlation receiver uses a fourth-order (intensity) interferometer to provide micron distance measurements even for weak (single photons) and short (femtosecond) optical signals. The optical correlator uses a low-noise-integrating detector that can resolve photon number. The correlation (range as a function of path delay) is calculated from the variance of the photon number of the difference of the optical signals on the two detectors. Our preliminary proof-of principle data (using a short-pulse diode laser transmitter) demonstrates tens of microns precision.

  8. Femtosecond Photon-Counting Receiver

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Rambo, Timothy M.; Yang, Guangning; Lu, Wei; Numata, Kenji

    2016-01-01

    An optical correlation receiver is described that provides ultra-precise distance and/or time/pulse-width measurements even for weak (single photons) and short (femtosecond) optical signals. A new type of optical correlation receiver uses a fourth-order (intensity) interferometer to provide micron distance measurements even for weak (single photons) and short (femtosecond) optical signals. The optical correlator uses a low-noise-integrating detector that can resolve photon number. The correlation (range as a function of path delay) is calculated from the variance of the photon number of the difference of the optical signals on the two detectors. Our preliminary proof-of principle data (using a short-pulse diode laser transmitter) demonstrates tens of microns precision.

  9. SAW correlator spread spectrum receiver

    DOEpatents

    Brocato, Robert W

    2014-04-01

    A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n.times.m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.

  10. Scintillation-Hardened GPS Receiver

    NASA Technical Reports Server (NTRS)

    Stephens, Donald R.

    2015-01-01

    CommLargo, Inc., has developed a scintillation-hardened Global Positioning System (GPS) receiver that improves reliability for low-orbit missions and complies with NASA's Space Telecommunications Radio System (STRS) architecture standards. A software-defined radio (SDR) implementation allows a single hardware element to function as either a conventional radio or as a GPS receiver, providing backup and redundancy for platforms such as the International Space Station (ISS) and high-value remote sensing platforms. The innovation's flexible SDR implementation reduces cost, weight, and power requirements. Scintillation hardening improves mission reliability and variability. In Phase I, CommLargo refactored an open-source GPS software package with Kalman filter-based tracking loops to improve performance during scintillation and also demonstrated improved navigation during a geomagnetic storm. In Phase II, the company generated a new field-programmable gate array (FPGA)-based GPS waveform to demonstrate on NASA's Space Communication and Navigation (SCaN) test bed.

  11. Digital-data receiver synchronization

    DOEpatents

    Smith, Stephen F.; Turner, Gary W.

    2005-08-02

    Digital-data receiver synchronization is provided with composite phase-frequency detectors, mutually cross-connected comparison feedback or both to provide robust reception of digital data signals. A single master clock can be used to provide frequency signals. Advantages can include fast lock-up time in moderately to severely noisy conditions, greater tolerance to noise and jitter when locked, and improved tolerance to clock asymmetries.

  12. Simultaneous Detection And Estimation Amid Strong Dynamical Effects

    NASA Technical Reports Server (NTRS)

    Kumar, Rajendra

    1991-01-01

    Effective signal-to-noise ratio several decibels greater than in previous schemes. Proposed for digital processing of received noisy, binary-phase-modulated radio signal for simultaneous detection of binary modulation and estimation of Doppler phase, frequency, and frequency derivative. Intended for use where relative motion between transmitter and receiver includes large velocities, strong accelerations, and/or intense jerks, resulting in possibly large Doppler frequency shifts with respect to time. Improves reception in radar, mobile/satellite communications, and navigation systems.

  13. Strong-back safety latch

    SciTech Connect

    DeSantis, G.N.

    1995-03-06

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch.

  14. Recent advances of strong-strong beam-beam simulation

    SciTech Connect

    Qiang, Ji; Furman, Miguel A.; Ryne, Robert D.; Fischer, Wolfram; Ohmi,Kazuhito

    2004-09-15

    In this paper, we report on recent advances in strong-strong beam-beam simulation. Numerical methods used in the calculation of the beam-beam forces are reviewed. A new computational method to solve the Poisson equation on nonuniform grid is presented. This method reduces the computational cost by a half compared with the standard FFT based method on uniform grid. It is also more accurate than the standard method for a colliding beam with low transverse aspect ratio. In applications, we present the study of coherent modes with multi-bunch, multi-collision beam-beam interactions at RHIC. We also present the strong-strong simulation of the luminosity evolution at KEKB with and without finite crossing angle.

  15. The professions: a critical review.

    PubMed

    Cripps, Y

    1986-09-13

    The professions have recently been subjected to intense scrutiny in the media. Increasingly, criticism is levelled at the professions collectively rather than at individual professions. Even when difficulties afflict a particular profession the resulting public debate affects other professional bodies. The changes that one profession makes to meet such criticisms inevitably influence the others. If, for example, a professional group decides to permit advertising by its members, the case of those who prefer to retain a restriction is weakened. If barristers may at some future date be consulted without the intermediation of a solicitor, why should not surgeons receive patients who have not visited a general practitioner? PMID:3776027

  16. Stennis group receives NESC award

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The NASA Engineering & Safety Center recently presented its Group Achievement Award to a Stennis team in recognition of technical excellence in evaluating the operational anomalies and reliability improvements associated with the space shuttle engine cut-off system. Stennis employees receiving the award were: (standing, l to r) Freddie Douglas (NASA), George Drouant (Jacobs Technology Inc.), Fred Abell (Jacobs), Robert Drackett (Jacobs) and Mike Smiles (NASA); (seated, l to r): Binh Nguyen (Jacobs), Stennis Director Gene Goldman and Joseph Lacker (NASA). Phillip Hebert of NASA is not pictured.

  17. Titanium: light, strong, and white

    USGS Publications Warehouse

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  18. Multistatic GNSS Receiver Array for Passive Air Surveillance

    NASA Astrophysics Data System (ADS)

    Wachtl, Stefan; Koch, Volker; Westphal, Robert; Schmidt, Lorenz-Peter

    2016-03-01

    The performance of a passive air surveillance sensor based on Global Navigation Satellite Systems (GNSS) is mainly limited by the receiver noise efficiency, the achievable signal processing gain and the radar cross section (RCS) of an airplane. For surveillance applications large detection ranges as well as a high probability of detection are crucial parameters. Due to the very low GNSS signal powers received on the earth's surface, high radar cross sections are mandatory to achieve detection ranges for airplanes at some kilometers distance. This paper will discuss a multistatic transmitter and receiver arrangement, which is indispensable to get a reasonable detection rate with respect to a hemispheric field of view. The strong performance dependency of such a sensor on the number of transmitters and receivers will be shown by means of some exemplary simulation results.

  19. Autocorrelation function of channel matrix in few-mode fibers with strong mode coupling.

    PubMed

    Hu, Qian; Shieh, William

    2013-09-23

    Channel matrix plays a critical role in receiver design and ultimate channel performance. To fully describe the channel matrix of a few-mode fiber (FMF), we choose the generalized high-dimensional Gell-Mann matrices, an equivalent of the 2-dimensional Pauli matrices used for a single-mode fiber (SMF), as the basis for the channel matrix decomposition. The frequency dependence of channel matrix can be studied in terms of the autocorrelation function (ACF), showing how fast channel changes in frequency domain. In this paper, we derive a canonical stochastic differential equation (SDE) for the FMF channel matrix in the regime of strong coupling. With the SDE, we develop an analytical form for the ACF of FMF channel matrix, from which the channel correlation bandwidth is obtained. PMID:24104107

  20. Front end for GPS receivers

    NASA Technical Reports Server (NTRS)

    Thomas, Jr., Jess Brooks (Inventor)

    1999-01-01

    The front end in GPS receivers has the functions of amplifying, down-converting, filtering and sampling the received signals. In the preferred embodiment, only two operations, A/D conversion and a sum, bring the signal from RF to filtered quadrature baseband samples. After amplification and filtering at RF, the L1 and L2 signals are each sampled at RF at a high selected subharmonic rate. The subharmonic sample rates are approximately 900 MHz for L1 and 982 MHz for L2. With the selected subharmonic sampling, the A/D conversion effectively down-converts the signal from RF to quadrature components at baseband. The resulting sample streams for L1 and L2 are each reduced to a lower rate with a digital filter, which becomes a straight sum in the simplest embodiment. The frequency subsystem can be very simple, only requiring the generation of a single reference frequency (e.g. 20.46 MHz minus a small offset) and the simple multiplication of this reference up to the subharmonic sample rates for L1 and L2. The small offset in the reference frequency serves the dual purpose of providing an advantageous offset in the down-converted carrier frequency and in the final baseband sample rate.

  1. Solar receiver with integrated optics

    NASA Astrophysics Data System (ADS)

    Jiang, Lun; Winston, Roland

    2012-10-01

    The current challenge for PV/Thermal (PV/T) systems is the reduction of radiation heat loss. Compared to solar thermal selective coating, the solar cells cannot be used as an efficient thermal absorber due to their large emissivity of the encapsulation material. Many commercial PV/T products therefore require a high concentration (more than 10x) to reach an acceptable thermal efficiency for their receivers. Such a concentration system inevitably has to track or semi-track, which induces additional cost and collects only the direct radiation from the sun. We propose a new PV/T design using a vacuum encapsulated thin film cell to solve this problem. The proposed design also collects the diffuse sun light efficiently by using an external compound parabolic concentrator (XCPC). Since the transparent electrode (TCO) of thin film cell is inherently transparent in visible light and reflective beyond infrared, this design uses this layer instead of the conventional solar cell encapsulation as the outmost heat loss surface. By integrating such a vacuum design with a tube shaped absorber, we reduce the complexity of conducting the heat energy and electricity out of the device. A low concentration standalone non-tracking solar collector is proposed in this paper. We also analyzed the thermosyphon system configuration using heat transfer and ray tracing models. The economics of such a receiver are presented.

  2. Simulating strongly correlated electrons with a strongly interacting Fermi gas

    SciTech Connect

    Thomas, John E.

    2013-05-28

    The quantum many-body physics of strongly-correlated fermions is studied in a degenerate, strongly- interacting atomic Fermi gas, first realized by our group with DOE support in 2002. This system, which exhibits strong spin pairing, is now widely studied and provides an important paradigm for testing predictions based on state-of-the-art many-body theory in fields ranging from nuclear matter to high temperature superfluidity and superconductivity. As the system is strongly interacting, both the superfluid and the normal fluid are nontrivial and of great interest. A central part of our program on Fermi gases is the connection between the study of thermodynamics, supported by DOE and the study of hydrodynamic transport, supported by NSF. This connection is especially interesting in view of a recent conjecture from the string theory community on the concept of nearly perfect normal fluids, which exhibit a minimum ratio of shear viscosity to entropy density in strongly-interacting, scale-invariant systems.

  3. Critical Pedagogy for Critical Mathematics Education

    ERIC Educational Resources Information Center

    Tutak, Fatma Aslan; Bondy, Elizabeth; Adams, Thomasenia L.

    2011-01-01

    This article provides a brief introduction to critical pedagogy and further discussion on critical mathematics education. Critical mathematics education enables students to read the world with mathematics. Three emerging domains of mathematics education related to critical mathematics education are discussed in this manuscript: ethnomathematics,…

  4. Low Noise 1.2 THz SIS Receiver

    NASA Technical Reports Server (NTRS)

    Karpov, A.; Miller, D.; Rice, F.; Zmuidzinas, J.; Stern, J. A.; Bumble, B.; LeDuc, H. G.

    2001-01-01

    We present the development of a low noise superconductor insulator superconductor (SIS) mixer for the 1.1 - 1.25 THz heterodyne receiver of FIRST space radiotelescope. The quasi-optical SIS mixer has two NbTiN/AlN/Nb junctions with critical current density 30 kA/sq cm. The individual junction area is close to 0.65 square micrometers. The SIS junctions are coupled to the optical input beam through a planar double slot antenna and a Si hyperhemispherical lens. The minimum DSB receiver noise temperature is 650 K, about 12 hv/k.

  5. A cryogenic receiver for EPR.

    PubMed

    Narkowicz, R; Ogata, H; Reijerse, E; Suter, D

    2013-12-01

    Cryogenic probes have significantly increased the sensitivity of NMR. Here, we present a compact EPR receiver design capable of cryogenic operation. Compared to room temperature operation, it reduces the noise by a factor of ≈2.5. We discuss in detail the design and analyze the resulting noise performance. At low microwave power, the input noise density closely follows the emission of a cooled 50Ω resistor over the whole measurement range from 20K up to room temperature. To minimize the influence of the microwave source noise, we use high microwave efficiency (≈1.1-1.7mTW(-1/2)) planar microresonators. Their efficient conversion of microwave power to magnetic field permits EPR measurements with very low power levels, typically ranging from a few μW down to fractions of nW. PMID:24161681

  6. Criticality Safety Evaluation of a LLNL Training Assembly for Criticality Safety (TACS)

    SciTech Connect

    Heinrichs, D P

    2006-06-26

    Hands-on experimental training in the physical behavior of multiplying systems is one of ten key areas of training required for practitioners to become qualified in the discipline of criticality safety as identified in DOE-STD-1135-99, ''Guidance for Nuclear Criticality Safety Engineer Training and Qualification''. This document is a criticality safety evaluation of the training activities (or operations) associated with HS-3200, ''Laboratory Class for Criticality Safety''. These activities utilize the Training Assembly for Criticality Safety (TACS). The original intent of HS-3200 was to provide LLNL fissile material handlers with a practical hands-on experience as a supplement to the academic training they receive biennially in HS-3100, ''Fundamentals of Criticality Safety'', as required by ANSI/ANS-8.20-1991, ''Nuclear Criticality Safety Training''. HS-3200 is to be enhanced to also address the training needs of nuclear criticality safety professionals under the auspices of the NNSA Nuclear Criticality Safety Program.

  7. 47 CFR 80.913 - Radiotelephone receivers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... receivers. (a) If a medium frequency radiotelephone installation is provided, the receiver must be capable... kHz, and the receiving frequency(s) of public coast stations serving the area in which the vessel is... reception of H3E and J3E emissions on 2182 kHz and J3E emission on any receiving frequency...

  8. 47 CFR 80.913 - Radiotelephone receivers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... receivers. (a) If a medium frequency radiotelephone installation is provided, the receiver must be capable... kHz, and the receiving frequency(s) of public coast stations serving the area in which the vessel is... reception of H3E and J3E emissions on 2182 kHz and J3E emission on any receiving frequency...

  9. 47 CFR 80.913 - Radiotelephone receivers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... receivers. (a) If a medium frequency radiotelephone installation is provided, the receiver must be capable... kHz, and the receiving frequency(s) of public coast stations serving the area in which the vessel is... reception of H3E and J3E emissions on 2182 kHz and J3E emission on any receiving frequency...

  10. Strongly Secure Linear Network Coding

    NASA Astrophysics Data System (ADS)

    Harada, Kunihiko; Yamamoto, Hirosuke

    In a network with capacity h for multicast, information Xh=(X1, X2, …, Xh) can be transmitted from a source node to sink nodes without error by a linear network code. Furthermore, secret information Sr=(S1, S2, …, Sr) can be transmitted securely against wiretappers by k-secure network coding for k≤h-r. In this case, no information of the secret leaks out even if an adversary wiretaps k edges, i. e. channels. However, if an adversary wiretaps k+1 edges, some Si may leak out explicitly. In this paper, we propose strongly k-secure network coding based on strongly secure ramp secret sharing schemes. In this coding, no information leaks out for every (Si1, Si2, …,Sir-j) even if an adversary wiretaps k+j channels. We also give an algorithm to construct a strongly k-secure network code directly and a transform to convert a nonsecure network code to a strongly k-secure network code. Furthermore, some sufficient conditions of alphabet size to realize the strongly k-secure network coding are derived for the case of k

  11. Development of an Air Brayton solar receiver

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Various receiver configurations and operating conditions were examined. The interface requirements between the receiver/concentrator/power module were addressed. Production cost estimates were obtained to determine the cost of the receiver during the 1980 timeframe. A conceptual design of an air Brayton solar receiver is presented based on the results. The following design goals were established: (1)peak thermal input power - 85 KWt; (2)receiver outlet air temperature - 1500 F; (3)receiver inlet air temperature - 1050 F; (4)design mass flow rate - 0.533 lb/sec; and (5)design receiver inlet pressure - 36.75 psia.

  12. Strong correlations in gravity and biophysics

    NASA Astrophysics Data System (ADS)

    Krotov, Dmitry

    The unifying theme of this dissertation is the use of correlations. In the first part (chapter 2), we investigate correlations in quantum field theories in de Sitter space. In the second part (chapters 3,4,5), we use correlations to investigate a theoretical proposal that real (observed in nature) transcriptional networks of biological organisms are operating at a critical point in their phase diagram. In chapter 2 we study the infrared dependence of correlators in various external backgrounds. Using the Schwinger-Keldysh formalism we calculate loop corrections to the correlators in the case of the Poincare patch and the complete de Sitter space. In the case of the Poincare patch, the loop correction modifies the behavior of the correlator at large distances. In the case of the complete de Sitter space, the loop correction has a strong dependence on the infrared cutoff in the past. It grows linearly with time, suggesting that at some point the correlations become strong and break the symmetry of the classical background. In chapter 3 we derive the signatures of critical behavior in a model organism, the embryo of Drosophila melanogaster. They are: strong correlations in the fluctuations of different genes, a slowing of dynamics, long range correlations in space, and departures from a Gaussian distribution of these fluctuations. We argue that these signatures are observed experimentally. In chapter 4 we construct an effective theory for the zero mode in this system. This theory is different from the standard Landau-Ginsburg description. It contains gauge fields (the result of the broken translational symmetry inside the cell), which produce observable contributions to the two-point function of the order parameter. We show that the behavior of the two-point function for the network of N genes is described by the action of a relativistic particle moving on the surface of the N - 1 dimensional sphere. We derive a theoretical bound on the decay of the correlations and

  13. Strong Bragg backscattering in reflectometry

    NASA Astrophysics Data System (ADS)

    Gusakov, E. Z.; Heuraux, S.; Popov, A. Yu

    2009-06-01

    The reflection of the probing microwave occurring in the vicinity of the backscattering Bragg resonance point (far from the cut-off) at a high enough density fluctuation level and leading to a large jump of the reflected wave phase and a corresponding time delay is described analytically using a 1D model. Explicit expressions for the reflection and transmission coefficients are derived and compared against results of numerical modelling. The criteria for transition to the nonlinear regime of strong Bragg backscattering (BBS) is obtained for both O-mode and X-mode reflectometry. It is shown that a strong nonlinear regime of BBS may occur in ITER at the 0.5-2% relative density perturbation level both for the ordinary and extraordinary mode probing. The possibility of probing wave trapping leading to strong enhancement of the electric field and associated high phase variation of the reflected wave due to BBS is demonstrated.

  14. Strongly interacting ultracold polar molecules

    NASA Astrophysics Data System (ADS)

    Gadway, Bryce; Yan, Bo

    2016-08-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole–dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  15. The SNAP Strong Lens Survey

    SciTech Connect

    Marshall, P.

    2005-01-03

    Basic considerations of lens detection and identification indicate that a wide field survey of the types planned for weak lensing and Type Ia SNe with SNAP are close to optimal for the optical detection of strong lenses. Such a ''piggy-back'' survey might be expected even pessimistically to provide a catalogue of a few thousand new strong lenses, with the numbers dominated by systems of faint blue galaxies lensed by foreground ellipticals. After sketching out our strategy for detecting and measuring these galaxy lenses using the SNAP images, we discuss some of the scientific applications of such a large sample of gravitational lenses: in particular we comment on the partition of information between lens structure, the source population properties and cosmology. Understanding this partitioning is key to assessing strong lens cosmography's value as a cosmological probe.

  16. Strong Photoassociation in Ultracold Fermions

    NASA Astrophysics Data System (ADS)

    Jing, Li; Jamison, Alan; Rvachov, Timur; Ebadi, Sepher; Son, Hyungmok; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2016-05-01

    Despite many studies there are still open questions about strong photoassociation in ultracold gases. Photoassociation occurs only at short range and thus can be used as a tool to probe and control the two-body correlation function in an interacting many-body system and to engineer Hamiltonians using dissipation. We propose the possibility to slow down decoherence by photoassociation through the quantum Zeno effect. This can realized by shining strong photoassociation light on the superposition of the lowest two hyperfine states of Lithium 6. NSF, ARO-MURI, Samsung, NSERC.

  17. The Parkes Ultra-Wideband Receiver

    NASA Astrophysics Data System (ADS)

    Manchester, Richard N.

    2015-08-01

    An ultra-wideband receiver system for the Parkes 64-m radio telescope covering the frequency range 0.7 - 4.0 GHz is currently under construction. Its main applications will be to pulsar studies, but it will also be used for spectral-line and continuum background polarisation studies and VLBI. A new feed design with remarkably constant beam properties across the band and excellent polarisation performance will be used. We plan to directly digitise the RF signals in the focus cabin and transmit the digital data via optical fibre to a versatile signal processing system using FPGA processors and a GPU cluster located in the telescope tower. With the relatively low radio frequency and very wide band, dealing with radio frequency interference is a critical issue. We have undertaken surveys of the RFI environment at Parkes and are developing several complementary techniques for mitigating the effects on data quality of both broad-band transients and quasi-stationary narrow-band signals.

  18. Fluid absorption solar energy receiver

    NASA Technical Reports Server (NTRS)

    Bair, Edward J.

    1993-01-01

    A conventional solar dynamic system transmits solar energy to the flowing fluid of a thermodynamic cycle through structures which contain the gas and thermal energy storage material. Such a heat transfer mechanism dictates that the structure operate at a higher temperature than the fluid. This investigation reports on a fluid absorption receiver where only a part of the solar energy is transmitted to the structure. The other part is absorbed directly by the fluid. By proportioning these two heat transfer paths the energy to the structure can preheat the fluid, while the energy absorbed directly by the fluid raises the fluid to its final working temperature. The surface temperatures need not exceed the output temperature of the fluid. This makes the output temperature of the gas the maximum temperature in the system. The gas can have local maximum temperatures higher than the output working temperature. However local high temperatures are quickly equilibrated, and since the gas does not emit radiation, local high temperatures do not result in a radiative heat loss. Thermal radiation, thermal conductivity, and heat exchange with the gas all help equilibrate the surface temperature.

  19. Lunar Receiving Laboratory Project History

    NASA Technical Reports Server (NTRS)

    Mangus, Susan; Larsen, William

    2004-01-01

    As early as 1959, the Working Group on Lunar Exploration within NASA advocated that 'one of the prime objectives of the first lunar landing mission should be the collection of samples for return to Earth, where they could be subjected to detailed study and analysis.' Within NASA, neither this group nor any other scientists working with the Agency were concerned about back contamination issues. Outside of NASA, back contamination concerns had been raised as early as 1960. Although NASA did not seem to pay any attention to the concerns at that time, the scientific community continued to be interested in the topic. In 1962 and again in 1963, as the Apollo Program loomed large, further discussions were held. These early discussions of back contamination did not make their way into NASA's administration, however, and when Manned Spacecraft Center personnel began to articulate early concepts for the Lunar Receiving Laboratory (LRL), the back contamination issue was not considered. Once this concern became a major focus, however, the LRL's development became increasingly complex. This is the history of that development.

  20. Recent developments in superconducting receivers

    SciTech Connect

    Richards, P.L.

    1990-09-01

    A description is given of recent work at Berkeley on superconducting mixers and detectors for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. The next report describes accurate measurements and also theoretical modeling of an SIS quasiparticle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high {Tc} superconductor YBCO from 750 GHz to 21 THz. Finally, there are reports on the design and experimental performance of two different types of high {Tc} bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer.

  1. Direct broadcast satellite-radio, space-segment/receiver tradeoffs

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser

    1993-01-01

    The balance between receiver complexity and the required satellite equivalent isotropically radiated power (EIRP) for Direct Broadcast Satellite-Radio (DBS-R) service is addressed. In general the required receiver complexity and cost can be reduced at the expense of higher space-segment cost by allowing a higher satellite EIRP. The tradeoff outcome is sensitive to the total number of anticipated receivers in a given service area, the number of audio programs, and the required audio quality. An understanding of optimum choice of satellite EIRP for DBS-R under various service requirements is a critical issue at this time when International Radio Consultative Committee (CCIR) is soliciting input in preparation for the International Telecommunications Union (ITU) planning conference for the service.

  2. PREFACE: Strongly Coupled Coulomb Systems Strongly Coupled Coulomb Systems

    NASA Astrophysics Data System (ADS)

    Neilson, David; Senatore, Gaetano

    2009-05-01

    This special issue contains papers presented at the International Conference on Strongly Coupled Coulomb Systems (SCCS), held from 29 July-2 August 2008 at the University of Camerino. Camerino is an ancient hill-top town located in the Apennine mountains of Italy, 200 kilometres northeast of Rome, with a university dating back to 1336. The Camerino conference was the 11th in a series which started in 1977: 1977: Orleans-la-Source, France, as a NATO Advanced Study Institute on Strongly Coupled Plasmas (hosted by Marc Feix and Gabor J Kalman) 1982: Les Houches, France (hosted by Marc Baus and Jean-Pierre Hansen) 1986: Santa Cruz, California, USA (hosted by Forrest J Rogers and Hugh E DeWitt) 1989: Tokyo, Japan (hosted by Setsuo Ichimaru) 1992: Rochester, New York, USA (hosted by Hugh M Van Horn and Setsuo Ichimaru) 1995: Binz, Germany (hosted by Wolf Dietrich Kraeft and Manfred Schlanges) 1997: Boston, Massachusetts, USA (hosted by Gabor J Kalman) 1999: St Malo, France (hosted by Claude Deutsch and Bernard Jancovici) 2002: Santa Fe, New Mexico, USA (hosted by John F Benage and Michael S Murillo) 2005: Moscow, Russia (hosted by Vladimir E Fortov and Vladimir Vorob'ev). The name of the series was changed in 1996 from Strongly Coupled Plasmas to Strongly Coupled Coulomb Systems to reflect a wider range of topics. 'Strongly Coupled Coulomb Systems' encompasses diverse many-body systems and physical conditions. The purpose of the conferences is to provide a regular international forum for the presentation and discussion of research achievements and ideas relating to a variety of plasma, liquid and condensed matter systems that are dominated by strong Coulomb interactions between their constituents. Each meeting has seen an evolution of topics and emphases that have followed new discoveries and new techniques. The field has continued to see new experimental tools and access to new strongly coupled conditions, most recently in the areas of warm matter, dusty plasmas

  3. STRONG HEART STUDY DATA BOOK

    EPA Science Inventory

    Epidemiologic study of cardiovascular disease in American Indians. Examination on the prevalence of major risk factors of CVD in American Indian men and women ages 45-74 in the American Indian communities from the three centers that participate in the Strong Heart Study.

  4. Strong coupling electroweak symmetry breaking

    SciTech Connect

    Barklow, T.L.; Burdman, G.; Chivukula, R.S.

    1997-04-01

    The authors review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. They emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. They also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models.

  5. A strongly coupled anyon material

    NASA Astrophysics Data System (ADS)

    Brattan, Daniel K.

    2015-11-01

    We use alternative quantisation of the D3-D5 system to explore properties of a strongly coupled anyon material at finite density and temperature. We study the transport properties of the material and find both diffusion and massive holographic zero sound modes. By studying the anyon number conductivity we also find evidence for the anyonic analogue of the metal-insulator transition.

  6. Bounds on corner entanglement in quantum critical states

    NASA Astrophysics Data System (ADS)

    Bueno, Pablo; Witczak-Krempa, William

    2016-01-01

    The entanglement entropy in many gapless quantum systems receives a contribution from the corners in the entangling surface in 2+1d, which is characterized by a universal function a (θ ) depending on the opening angle θ , and contains pertinent low energy information. For conformal field theories (CFTs), the leading expansion coefficient in the smooth limit θ →π yields the stress tensor two-point function coefficient CT. Little is known about a (θ ) beyond that limit. Here, we show that the next term in the smooth limit expansion contains information beyond the two- and three-point correlators of the stress tensor. We conjecture that it encodes four-point data, making it much richer. Further, we establish strong constraints on this and higher-order smooth-limit coefficients. We also show that a (θ ) is lower-bounded by a nontrivial function multiplied by the central charge CT, e.g., a (π /2 ) ≥(π2ln2 ) CT/6 . This bound for 90-degree corners is nearly saturated by all known results, including recent numerics for the interacting Wilson-Fisher quantum critical points (QCPs). A bound is also given for the Rényi entropies. We illustrate our findings using O(N ) QCPs, free boson and Dirac fermion CFTs, strongly coupled holographic ones, and other models. Exact results are also given for Lifshitz quantum critical points, and for conical singularities in 3+1d.

  7. Thermal resistance model for CSP central receivers

    NASA Astrophysics Data System (ADS)

    de Meyer, O. A. J.; Dinter, F.; Govender, S.

    2016-05-01

    The receiver design and heliostat field aiming strategy play a vital role in the heat transfer efficiency of the receiver. In molten salt external receivers, the common operating temperature of the heat transfer fluid or molten salt ranges between 285°C to 565°C. The optimum output temperature of 565°C is achieved by adjusting the mass flow rate of the molten salt through the receiver. The reflected solar radiation onto the receiver contributes to the temperature rise in the molten salt by means of heat transfer. By investigating published work on molten salt external receiver operating temperatures, corresponding receiver tube surface temperatures and heat losses, a model has been developed to obtain a detailed thermographic representation of the receiver. The steady state model uses a receiver flux map as input to determine: i) heat transfer fluid mass flow rate through the receiver to obtain the desired molten salt output temperature of 565°C, ii) receiver surface temperatures iii) receiver tube temperatures iv) receiver efficiency v) pressure drop across the receiver and vi) corresponding tube strain per panel.

  8. Growing a strong middle class.

    PubMed

    O'Malley, Martin

    2009-01-01

    An important mission for the country is achieving sustainability while strengthening the middle class. American leadership and innovation can play a critical role in defining the interconnectedness of our economy and environment-and in unlocking, harnessing, and advancing green technologies. The State of Maryland has launched a Green Jobs Initiative focused on attracting green businesses, working with existing businesses to adopt sustainable practices, promoting clean energy research and use, and training the work force for ne, green-collar jobs. PMID:19608500

  9. Stimulated Superconductivity at Strong Coupling

    SciTech Connect

    Bao, Ning; Dong, Xi; Silverstein, Eva; Torroba, Gonzalo; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC

    2011-08-12

    Stimulating a system with time dependent sources can enhance instabilities, thus increasing the critical temperature at which the system transitions to interesting low-temperature phases such as superconductivity or superfluidity. After reviewing this phenomenon in non-equilibrium BCS theory (and its marginal fermi liquid generalization) we analyze the effect in holographic superconductors. We exhibit a simple regime in which the transition temperature increases parametrically as we increase the frequency of the time-dependent source.

  10. Quality control by <strong>HyperS>pectral <strong>I>maging (HSI) in solid waste recycling: logics, algorithms and procedures

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Serranti, Silvia

    2014-03-01

    In secondary raw materials and recycling sectors, the products quality represents, more and more, the key issue to pursuit in order to be competitive in a more and more demanding market, where quality standards and products certification play a preheminent role. These goals assume particular importance when recycling actions are applied. Recovered products, resulting from waste materials, and/or dismissed products processing, are, in fact, always seen with a certain suspect. An adequate response of the industry to the market can only be given through the utilization of equipment and procedures ensuring pure, high-quality production, and efficient work and cost. All these goals can be reached adopting not only more efficient equipment and layouts, but also introducing new processing logics able to realize a full control of the handled material flow streams fulfilling, at the same time, i) an easy management of the procedures, ii) an efficient use of the energy, iii) the definition and set up of reliable and robust procedures, iv) the possibility to implement network connectivity capabilities finalized to a remote monitoring and control of the processes and v) a full data storage, analysis and retrieving. Furthermore the ongoing legislation and regulation require the implementation of recycling infrastructure characterised by high resources efficiency and low environmental impacts, both aspects being strongly linked to the waste materials and/or dismissed products original characteristics. For these reasons an optimal recycling infrastructure design primarily requires a full knowledge of the characteristics of the input waste. What previously outlined requires the introduction of a new important concept to apply in solid waste recycling, the recycling-oriented characterization, that is the set of actions addressed to strategically determine selected attributes, in order to get goaloriented data on waste for the development, implementation or improvement of recycling

  11. EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Ronning, Filip; Batista, Cristian

    2011-03-01

    Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed

  12. PREFACE: Strongly correlated electron systems Strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Saxena, Siddharth S.; Littlewood, P. B.

    2012-07-01

    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

  13. Structuring a sound securitization of healthcare receivables.

    PubMed

    Spradling, Mark

    2003-02-01

    Securitization of receivables allows healthcare providers to obtain an additional funding source by selling their accounts receivables to investors. A double-lock-box structure allows providers to securitize Medicare and Medicaid receivables without violating federal laws. A 2001 revision to the Uniform Commercial Code facilitates providers' securitization of private healthcare insurance receivables by underscoring rights of a purchaser of those receivables. HIPAA privacy standards appear to permit the use and disclosure of protected health information in crafting a securitization program. The securitization should be structured to shield the value of the receivables to be transferred from the potential backruptcies of the originator and the purchaser. PMID:12602313

  14. Warren Receives 2004 Maurice Ewing Medal

    NASA Astrophysics Data System (ADS)

    Speer, Kevin

    2005-01-01

    Bruce A. Warren received the Ewing Medal at the 2004 Fall Meeting Honors Ceremony on 15 December, in San Francisco, California. The medal is given for significant original contributions to the scientific understanding of the processes in the ocean; for the advancement of oceanographic engineering, technology, and instrumentation; and for outstanding service to marine sciences. Citation. Bruce Warren is a physical oceanographer and scientist emeritus at the Woods Hole Oceanographic Institution, where he has spent his entire career. Few can claim to have personally unearthed so many distinct elements of the World Ocean circulation as Bruce. At the beginning of his career, oceanographers were working out the implications of the still relatively fresh idea that the large-scale circulation tends to concentrate flow at the western boundary of ocean basins in strong western boundary currents like the Gulf Stream and Kuroshio. During his Ph.D. years, Stommel and Arons published their simple but far-reaching dynamical framework for deep circulation in the ocean, and these concepts and extensions were nowhere better tested than in Bruce's field investigations of deep circulation in almost every major ocean basin in the world. Bruce never failed to point out how, for good reason, other explanations were usually less compelling. His application of Occam's Razor to all work, including his own, is fierce and famous.

  15. Inclusive Discourse in Greece: Strong Voices, Weak Policies

    ERIC Educational Resources Information Center

    Zoniou-Sideri, Athina; Deropoulou-Derou, Eudoxia; Karagianni, Panagiota; Spandagou, Ilektra

    2006-01-01

    This paper explores the inclusive discourse in Greece at a period characterized by change in policy and practice. The aim is to discuss critically the distance between the strong voices and weak practices that characterizes the Greek inclusive discourse. The first part focuses on disability and presents the ways that a "common sense" understanding…

  16. DYNAMICS OF STRONGLY TWISTED RELATIVISTIC MAGNETOSPHERES

    SciTech Connect

    Parfrey, Kyle; Beloborodov, Andrei M.; Hui, Lam

    2013-09-10

    Magnetar magnetospheres are believed to be strongly twisted due to shearing of the stellar crust by internal magnetic stresses. We present time-dependent axisymmetric simulations showing in detail the evolution of relativistic force-free magnetospheres subjected to slow twisting through large angles. When the twist amplitude is small, the magnetosphere moves quasi-statically through a sequence of equilibria of increasing free energy. At some twist amplitude the magnetosphere becomes tearing-mode unstable to forming a resistive current sheet, initiating large-scale magnetic reconnection in which a significant fraction of the magnetic free energy can be dissipated. This ''critical'' twist angle is insensitive to the resistive length scale. Rapid shearing temporarily stabilizes the magnetosphere beyond the critical angle, allowing the magnetosphere of a rapidly differentially rotating star to store and dissipate more free energy. In addition to these effects, shearing the surface of a rotating star increases the spindown torque applied to the star. If shearing is much slower than rotation, the resulting spikes in spindown rate can occur on timescales anywhere from the long twisting timescale to the stellar spin period or shorter, depending both on the stellar shear distribution and the existing distribution of magnetospheric twists. A model in which energy is stored in the magnetosphere and released by a magnetospheric instability therefore predicts large changes in the measured spindown rate before soft gamma repeater giant flares.

  17. Safe patient handling program in critical care using peer leaders: lessons learned in the Netherlands.

    PubMed

    Knibbe, Hanneke J J; Knibbe, Nico E; Klaassen, Annemarie J W M

    2007-06-01

    Occupational back pain remains a serious problem for nurses. In Dutch health care, ergonomic changes are stimulated through convenants. For acute and critical care, a covenant was drawn up and guidelines for nursing practice developed and implemented. Because of the diverse and rapidly changing nature of ergonomic problems, the process has to be specific. A strong emphasis thus was placed on self-management and empowerment of nurses. One or two nurses were appointed per ward as peer leaders, called ergocoaches. They received additional training and were given responsibility for safe work practices. This article reports on progress made to date, viewed as work in progress. PMID:17512476

  18. Radiation Dose Optimization For Critical Organs

    NASA Astrophysics Data System (ADS)

    Khodadadegan, Yasaman

    Ionizing radiation used in the patient diagnosis or therapy has negative effects on the patient body in short term and long term depending on the amount of exposure. More than 700,000 examinations are everyday performed on Interventional Radiology modalities, however; there is no patient-centric information available to the patient or the Quality Assurance for the amount of organ dose received. In this study, we are exploring the methodologies to systematically reduce the absorbed radiation dose in the Fluoroscopically Guided Interventional Radiology procedures. In the first part of this study, we developed a mathematical model which determines a set of geometry settings for the equipment and a level for the energy during a patient exam. The goal is to minimize the amount of absorbed dose in the critical organs while maintaining image quality required for the diagnosis. The model is a large-scale mixed integer program. We performed polyhedral analysis and derived several sets of strong inequalities to improve the computational speed and quality of the solution. Results present the amount of absorbed dose in the critical organ can be reduced up to 99% for a specific set of angles. In the second part, we apply an approximate gradient method to simultaneously optimize angle and table location while minimizing dose in the critical organs with respect to the image quality. In each iteration, we solve a sub-problem as a MIP to determine the radiation field size and corresponding X-ray tube energy. In the computational experiments, results show further reduction (up to 80%) of the absorbed dose in compare with previous method. Last, there are uncertainties in the medical procedures resulting imprecision of the absorbed dose. We propose a robust formulation to hedge from the worst case absorbed dose while ensuring feasibility. In this part, we investigate a robust approach for the organ motions within a radiology procedure. We minimize the absorbed dose for the critical

  19. Composite strongly interacting dark matter

    NASA Astrophysics Data System (ADS)

    Cline, James M.; Liu, Zuowei; Moore, Guy D.; Xue, Wei

    2014-07-01

    It has been suggested that cold dark matter (CDM) has difficulties in explaining tentative evidence for noncuspy halo profiles in small galaxies, and the low velocity dispersions observed in the largest Milky Way satellites ("too-big-to-fail" problem). Strongly self-interacting dark matter has been noted as a robust solution to these problems. The elastic cross sections required are much larger than predicted by generic CDM models, but could naturally be of the right size if dark matter is composite. We explore in a general way the constraints on models where strongly interacting CDM is in the form of dark "atoms" or "molecules," or bound states of a confining gauge interaction ("hadrons"). These constraints include considerations of relic density, direct detection, big bang nucleosynthesis, the cosmic microwave background, and LHC data.

  20. Heat transfer in a fluidized-bed solar thermal receiver

    SciTech Connect

    Bachovchin, D.M.; Archer, D.H.; Neale, D.H.

    1983-01-01

    The authors investigated the use of a fluidized bed as a solar thermal receiver. A 0.3 m diameter, quartz-walled bed was designed, built, and tested at a 325 kW, solar thermal test facility. Various large-particle bed materials were tested, and we found that strong temperature gradients existed in the fluidized bed exposed to concentrated solar radiation. A heat transfer analysis is presented and effective bed thermal conductivities are estimated.

  1. Multiscale hyporheic exchange through strongly heterogeneous sediments

    NASA Astrophysics Data System (ADS)

    Pryshlak, Timothy T.; Sawyer, Audrey H.; Stonedahl, Susa H.; Soltanian, Mohamad Reza

    2015-11-01

    Heterogeneity in hydraulic conductivity (K) and channel morphology both control surface water-groundwater exchange (hyporheic exchange), which influences stream ecosystem processes and biogeochemical cycles. Here we show that heterogeneity in K is the dominant control on exchange rates, residence times, and patterns in hyporheic zones with abrupt lithologic contrasts. We simulated hyporheic exchange in a representative low-gradient stream with 300 different bimodal K fields composed of sand and silt. Simulations span five sets of sand-silt ratios and two sets of low and high K contrasts (1 and 3 orders of magnitude). Heterogeneity increases interfacial flux by an order of magnitude relative to homogeneous cases, drastically changes the shape of residence time distributions, and decreases median residence times. The positioning of highly permeable sand bodies controls patterns of interfacial flux and flow paths. These results are remarkably different from previous studies of smooth, continuous K fields that indicate only moderate effects on hyporheic exchange. Our results also show that hyporheic residence times are least predictable when sand body connectivity is low. As sand body connectivity increases, the expected residence time distribution (ensemble average for a given sand-silt ratio) remains approximately constant, but the uncertainty around the expectation decreases. Including strong heterogeneity in hyporheic models is imperative for understanding hyporheic fluxes and solute transport. In streams with strongly heterogeneous sediments, characterizing lithologic structure is more critical for predicting hyporheic exchange metrics than characterizing channel morphology.

  2. Electrodynamics of strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Dordevic, Sasa V.

    2002-09-01

    In this thesis we study a variety of condensed matter systems with strongly correlated electrons, i.e. systems in which the electron-electron interactions cannot be ignored like in conventional metals, (gold, aluminum, copper, etc.). Infrared spectroscopy has proven to be a powerful tool for studying such systems. The latter experimental technique probes all excitations is solids that have a dipole moment associated with them, such as gap excitations, interband transitions, phonons, polarons, magnons etc. Strong electron correlations lead to a variety of interesting physical phenomena at low temperatures. In copper ox ides superconductivity sets in below an unprecedently high critical temperature, Tc. The mechanism of this unusual phenomenon is still unclear. In this thesis we discuss energy scales from which the superconducting condensate is collected and the response of cuprates to an external magnetic field applied parallel to the CuO2 planes. In so-called heavy fermion metals a coherent ground state develops at low temperatures where the electrons appear to have large effective mass, typically 50--1,000 free electron masses. We show that magnetic interactions play an important role for the mass renormalization in heavy fermion metals. In transition metal dichalcogenides reduced dimensionality of the electron gas leads to significant anisotropy of the electron-phonon interaction.

  3. Strongly interacting parton matter equilibration

    SciTech Connect

    Ozvenchuk, V.; Linnyk, O.; Bratkovskaya, E.; Gorenstein, M.; Cassing, W.

    2012-07-15

    We study the kinetic and chemical equilibration in 'infinite' parton matter within the Parton-Hadron-String Dynamics transport approach. The 'infinite' matter is simulated within a cubic box with periodic boundary conditions initialized at different energy densities. Particle abundances, kinetic energy distributions, and the detailed balance of the off-shell quarks and gluons in the strongly-interacting quarkgluon plasma are addressed and discussed.

  4. Strong CP and SUZ2

    NASA Astrophysics Data System (ADS)

    Albaid, Abdelhamid; Dine, Michael; Draper, Patrick

    2015-12-01

    Solutions to the strong CP problem typically introduce new scales associated with the spontaneous breaking of symmetries. Absent any anthropic argument for small overline{θ} , these scales require stabilization against ultraviolet corrections. Supersymmetry offers a tempting stabilization mechanism, since it can solve the "big" electroweak hierarchy problem at the same time. One family of solutions to strong CP, including generalized parity models, heavy axion models, and heavy η' models, introduces {Z}_2 copies of (part of) the Standard Model and an associated scale of {Z}_2 -breaking. We review why, without additional structure such as supersymmetry, the {Z}_2 -breaking scale is unacceptably tuned. We then study "SUZ2" models, supersymmetric theories with {Z}_2 copies of the MSSM. We find that the addition of SUSY typically destroys the {Z}_2 protection of overline{θ}=0 , even at tree level, once SUSY and {Z}_2 are broken. In theories like supersymmetric completions of the twin Higgs, where {Z}_2 addresses the little hierarchy problem but not strong CP, two axions can be used to relax overline{θ}.

  5. Percentage of Surgical Patients Receiving Recommended Care

    MedlinePlus

    ... Recommended Care Percentage of Surgical Patients Receiving Recommended Care This is a composite measure based on individual ... Age Group Percentage of Surgical Patients Receiving Recommended Care by Age Group uzrc-9bvr Download these data » ...

  6. 47 CFR 32.1170 - Receivables.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... demand or time notes, bills and drafts receivable, or other similar evidences (except interest coupons) of money receivable on demand or within a time not exceeding one year from date of issue. (d)...

  7. Optimization of MLS receivers for multipath environments

    NASA Technical Reports Server (NTRS)

    Mcalpine, G. A.; Irwin, S. H.; NELSON; Roleyni, G.

    1977-01-01

    Optimal design studies of MLS angle-receivers and a theoretical design-study of MLS DME-receivers are reported. The angle-receiver results include an integration of the scan data processor and tracking filter components of the optimal receiver into a unified structure. An extensive simulation study comparing the performance of the optimal and threshold receivers in a wide variety of representative dynamical interference environments was made. The optimal receiver was generally superior. A simulation of the performance of the threshold and delay-and-compare receivers in various signal environments was performed. An analysis of combined errors due to lateral reflections from vertical structures with small differential path delays, specular ground reflections with neglible differential path delays, and thermal noise in the receivers is provided.

  8. Advanced solar receivers for space power

    NASA Technical Reports Server (NTRS)

    Strumpf, H. J.; Coombs, M. G.; Lacy, D. E.

    1988-01-01

    A study has been conducted to generate and evaluate advanced solar heat receiver concepts suitable for orbital application with Brayton and Stirling engine cycles in the 7-kW size range. The generated receiver designs have thermal storage capability and, when implemented, will be lighter, smaller, and/or more efficient than baseline systems such as the configuration used for the Brayton solar receiver under development by Garrett AiResearch for the NASA Space Station. In addition to the baseline designs, four other receiver concepts were designed and evaluated with respect to Brayton and Stirling engines. These concepts include a higher temperature version of the baseline receiver, a packed bed receiver, a plate-fin receiver, and a heat pipe receiver. The thermal storage for all designs is provided by the melting and freezing of a salt.

  9. Trough Receiver Heat Loss Testing (Presentation)

    SciTech Connect

    Lewandowski, A.; Feik, C.; Hansen, R.; Phillips, S.; Bingham, C.; Netter, J.; Forristal, R.; Burkholder, F.; Meglan, B.; Wolfrum, E.

    2006-02-01

    This presentation describes the design, fabrication, and qualification of an experimental capability for thermal loss testing of full-size trough receiver elements; and the testing on a variety of receivers.

  10. How To Improve You Shipping and Receiving.

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2001-01-01

    Discusses how two universities improved their shipping and receiving operations and cut costs. Examples from the University of Texas at Dallas and John Hopkins University, Baltimore, Maryland, illustrate how they established greater shipping and receiving department efficiencies. (GR)