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Sample records for simulated clinical conditions

  1. Resin-based composite light-cured properties assessed by laboratory standards and simulated clinical conditions.

    PubMed

    Ilie, N; Bauer, H; Draenert, M; Hickel, R

    2013-01-01

    SUMMARY The following parameters were varied: 1) irradiation technique: top and bottom polymerization according to the ISO standard, and polymerization from only the top, simulating clinical situations; 2) polymerization time: 5, 10, 20, and 40 seconds; 3) storage conditions: 24 hours in distilled water, thermocycling followed by storage for four weeks in artificial saliva or alcohol. Flexural strength (FS), flexural modulus (Eflexural), indentation modulus (E), Vickers hardness (HV), and degree of conversion (DC) were measured. The laboratory results were similar to those measured by mimicking clinical conditions only at high polymerization times and mild storage conditions (20 seconds and 40 seconds and storage for 24 hours in water, and 40 seconds with aging and storing in saliva). Significantly higher DC values were measured on the top than on the bottom of a 2-mm layer for all polymerization times. Overall, 5-second and 10-second irradiation times induced significantly lower DC values compared to the currently recommended polymerization times of 20 and 40 seconds at both the top and bottom of the samples. The initial DC differences as a function of irradiation time are leveled at 24 hours of storage but seem to do well in predicting long-term material behavior. A minimum irradiation time of 20 seconds is necessary clinically to achieve the best mechanical properties with modern high-intensity light emitting diode (LED) units.

  2. In vitro simulation of pathological bone conditions to predict clinical outcome of bone tissue engineered materials

    NASA Astrophysics Data System (ADS)

    Nguyen, Duong Thuy Thi

    According to the Centers for Disease Control, the geriatric population of ≥65 years of age will increase to 51.5 million in 2020; 40% of white women and 13% of white men will be at risk for fragility fractures or fractures sustained under normal stress and loading conditions due to bone disease, leading to hospitalization and surgical treatment. Fracture management strategies can be divided into pharmaceutical therapy, surgical intervention, and tissue regeneration for fracture prevention, fracture stabilization, and fracture site regeneration, respectively. However, these strategies fail to accommodate the pathological nature of fragility fractures, leading to unwanted side effects, implant failures, and non-unions. Compromised innate bone healing reactions of patients with bone diseases are exacerbated with protective bone therapy. Once these patients sustain a fracture, bone healing is a challenge, especially when fracture stabilization is unsuccessful. Traditional stabilizing screw and plate systems were designed with emphasis on bone mechanics rather than biology. Bone grafts are often used with fixation devices to provide skeletal continuity at the fracture gap. Current bone grafts include autologous bone tissue and donor bone tissue; however, the quality and quantity demanded by fragility fractures sustained by high-risk geriatric patients and patients with bone diseases are not met. Consequently, bone tissue engineering strategies are advancing towards functionalized bone substitutes to provide fracture reconstruction while effectively mediating bone healing in normal and diseased fracture environments. In order to target fragility fractures, fracture management strategies should be tailored to allow bone regeneration and fracture stabilization with bioactive bone substitutes designed for the pathological environment. The clinical outcome of these materials must be predictable within various disease environments. Initial development of a targeted

  3. [Clinical aspects and the course of psychopathologic conditions simulating vertebrogenic pathology].

    PubMed

    Ostroglazov, V G; Lisina, M A

    1989-01-01

    The study of clinical picture and the course of unclear pathological states simulating the vertebral pathology suggested that the major signs were centered around the primary general and muscular sensory disorders. These served as a basis for development of more complicated psychosensory and psychomotor disorders and creation of an interpretative hypochondriac++ delirium system. Domination of psychomotor disorders led to a high incidence of social and labor dysadaptation of the patients. Thus, the study of this unclear mental pathology has a major theoretic, clinico-psychopathological and also practical medico-social importance.

  4. Wear of novel ceramic-on-ceramic bearings under adverse and clinically relevant hip simulator conditions.

    PubMed

    Al-Hajjar, Mazen; Jennings, Louise M; Begand, Sabine; Oberbach, Thomas; Delfosse, Daniel; Fisher, John

    2013-11-01

    Further development of ceramic materials for total hip replacement aim to increase fracture toughness and further reduce the incidence of bearing fracture. Edge loading due to translational mal positioning (microseparation) has replicated stripe wear, wear rates, and bimodal wear debris observed on retrievals. This method has replicated the fracture of early zirconia ceramic-on-ceramic bearings. This has shown the necessity of introducing microseparation conditions to the gait cycle when assessing the tribological performance of new hip replacement bearings. Two novel ceramic matrix composite materials, zirconia-toughened alumina (ZTA) and alumina-toughened zirconia (ATZ), were developed by Mathys Orthopädie GmbH. In this study, ATZ-on-ATZ and ZTA-on-ZTA bearing combinations were tested and compared with alumina-on-alumina (Al2O3-on-Al2O3) bearings under adverse microseparation and edge loading conditions using the Leeds II physiological anatomical hip joint simulator. The wear rate (±95% confidence limit) of ZTA-on-ZTA was 0.14 ± 0.10 mm(3)/million cycles and that of ATZ-on-ATZ was 0.06 ± 0.004 mm(3)/million cycles compared with a wear rate of 0.74 ± 1.73 mm(3)/million cycles for Al2O3-on-Al2O3 bearings. Stripe wear was evident on all bearing combinations; however, the stripe formed on the ATZ and ZTA femoral heads was thinner and shallower that that formed on the Al2O3 heads. Posttest phase composition measurements for both ATZ and ZTA materials showed no significant change in the monoclinic zirconia content. ATZ-on-ATZ and ZTA-on-ZTA showed superior wear resistance properties when compared with Al2O3-on-Al2O3 under adverse edge loading conditions.

  5. Measuring the Influence of Galilean Loupe System on Near Visual Acuity of Dentists under Simulated Clinical Conditions

    PubMed Central

    Urlic, Iris; Verzak, Željko; Vranic, Dubravka Negovetic

    2016-01-01

    Aim The purpose of this study was to compare near visual acuity of dentists without optical aids (VSC) with near visual acuity of those using the Galilean telescope system (VGA2) with magnification of x 2.5, and the distance of 350 mm in simulated clinical conditions. Methods The study included 46 dentists (visual acuity 1.0 without correction). A visual acuity testing was carried out using a miniaturized Snellen visual acuity chart which was placed in the cavity of molar teeth mounted in a phantom head in simulated clinical conditions. Near visual acuity for the vicinity was examined: 1) without correction at a distance of 300-400 mm (VSC); 2) with Galilean loupes with magnification of x2.5, focal length of 350mm. Results The distributions of near visual acuity recorded using VSC and VGA2, 5 systems were compared by the Wilcoxon Signed Rank test. The results obtained by Wilcoxon Signed Rank test pointed to a statistically significant difference in the distribution of recorded visual acuity between the VSC and VGA2 optical systems (W = - 403.5; p <0.001). Conclusion If using the VGA2, 5 systems, higher values of the near visual acuity were recorded and subsequently compared to near visual acuity without magnifying aids (VSC). PMID:27847397

  6. Bacteria under simulated Martian conditions.

    PubMed

    Young, R S; Deal, P H; Bell, J; Allen, J L

    1964-01-01

    The behavior of organisms in simulated Martian conditions is of great importance to exobiology for two reasons: (1) Because of the extreme environment of Mars, the likelihood of contamination of the planet by earth organisms is considered slight by some scientists. To date, there has been little evidence to contradict this supposition. Such evidence is presented. (2) The selection and adaptation of earth bacteria to Martian conditions is potentially significant in understanding Martian life, if it exists, and may be helpful in designing life-detection techniques and devices. Of course, simulation attempts, based on current knowledge of the Mars environment, may be far from the actual conditions, and extrapolations made from such situations of no real significance. However, generalizations can be made and cautious interpretation of the results of those experiments seems well worth reporting. A new technique for simulation of known parameters of the Martian environment is discussed along with possible biological implications. The response of bacteria to such simulation is demonstrated in terms of survival and growth, showing that certain bacteria will not only survive, but grow during simulated Martian freeze-thaw cycling if water is present. Ways are demonstrated in which water can be present on Mars although not detectable with current technology. Plans for future experimentation are discussed.

  7. PET-based dose delivery verification in proton therapy: a GATE based simulation study of five PET system designs in clinical conditions.

    PubMed

    Robert, Charlotte; Fourrier, Nicolas; Sarrut, David; Stute, Simon; Gueth, Pierre; Grevillot, Loïc; Buvat, Irène

    2013-10-07

    PET is a promising technique for in vivo treatment verification in hadrontherapy. Three main PET geometries dedicated to in-beam treatment monitoring have been proposed in the literature: the dual-head PET geometry, the OpenPET geometry and the slanted-closed ring geometry. The aim of this work is to characterize the performance of two of these dedicated PET detectors in realistic clinical conditions. Several configurations of the dual-head PET and OpenPET systems were simulated using GATE v6.2. For the dual-head configuration, two aperture angles (15° and 45°) were studied. For the OpenPET system, two gaps between rings were investigated (110 and 160 mm). A full-ring PET system was also simulated as a reference. After preliminary evaluation of the sensitivity and spatial resolution using a Derenzo phantom, a real small-field head and neck treatment plan was simulated, with and without introducing patient displacements. No wash-out was taken into account. 3D maps of the annihilation photon locations were deduced from the PET data acquired right after the treatment session (5 min acquisition) using a dedicated OS-EM reconstruction algorithm. Detection sensitivity at the center of the field-of-view (FOV) varied from 5.2% (45° dual-head system) to 7.0% (full-ring PET). The dual-head systems had a more uniform efficiency within the FOV than the OpenPET systems. The spatial resolution strongly depended on the location within the FOV for the ϕ = 45° dual-head system and for the two OpenPET systems. All investigated architectures identified the magnitude of mispositioning introduced in the simulations within a 1.5 mm accuracy. The variability on the estimated mispositionings was less than 2 mm for all PET systems.

  8. PET-based dose delivery verification in proton therapy: a GATE based simulation study of five PET system designs in clinical conditions

    NASA Astrophysics Data System (ADS)

    Robert, Charlotte; Fourrier, Nicolas; Sarrut, David; Stute, Simon; Gueth, Pierre; Grevillot, Loïc; Buvat, Irène

    2013-10-01

    PET is a promising technique for in vivo treatment verification in hadrontherapy. Three main PET geometries dedicated to in-beam treatment monitoring have been proposed in the literature: the dual-head PET geometry, the OpenPET geometry and the slanted-closed ring geometry. The aim of this work is to characterize the performance of two of these dedicated PET detectors in realistic clinical conditions. Several configurations of the dual-head PET and OpenPET systems were simulated using GATE v6.2. For the dual-head configuration, two aperture angles (15° and 45°) were studied. For the OpenPET system, two gaps between rings were investigated (110 and 160 mm). A full-ring PET system was also simulated as a reference. After preliminary evaluation of the sensitivity and spatial resolution using a Derenzo phantom, a real small-field head and neck treatment plan was simulated, with and without introducing patient displacements. No wash-out was taken into account. 3D maps of the annihilation photon locations were deduced from the PET data acquired right after the treatment session (5 min acquisition) using a dedicated OS-EM reconstruction algorithm. Detection sensitivity at the center of the field-of-view (FOV) varied from 5.2% (45° dual-head system) to 7.0% (full-ring PET). The dual-head systems had a more uniform efficiency within the FOV than the OpenPET systems. The spatial resolution strongly depended on the location within the FOV for the ϕ = 45° dual-head system and for the two OpenPET systems. All investigated architectures identified the magnitude of mispositioning introduced in the simulations within a 1.5 mm accuracy. The variability on the estimated mispositionings was less than 2 mm for all PET systems.

  9. Thrombin generation in clinical conditions.

    PubMed

    Ten Cate, Hugo

    2012-03-01

    Commercial assays for determining thrombin generation in plasma are being tested in clinical conditions associated with thrombosis or bleeding. While pre-analytical conditions remain a source of inter laboratory variation, demanding for further standardization, clinical research proceeds. In patients at risk of venous thrombosis thrombin generation (TG) analysis may be utilized to detect underlying thrombophilia and this has been achieved both with addition of thrombomodulin or activated protein C, to test the contribution of the protein C system. In patients with documented venous thromboembolism, increased TG values are seen in those patients at greatest risk for recurrence, although the data are not consistent yet. In patients with arterial vascular disease, effects on TG patterns are seen that both reflect atherosclerosis (and its risk factors) and link to risk of recurrent atherothrombosis (coronary or stroke), but the data are limited. In patients with a bleeding diathesis, like hemophilia, the main importance of TG assays lies in the application for monitoring replacement therapy, either with factor concentrate or rFVIIa. An interesting application is in conjunction with thromboelastography, for monitoring peri-operative transfusion policy. Finally, TG analysis may contribute to monitoring anticoagulant drug treatment, but these and other applications would greatly benefit from whole blood, point of care applications of TG testing.

  10. Clinic Workflow Simulations using Secondary EHR Data

    PubMed Central

    Hribar, Michelle R.; Biermann, David; Read-Brown, Sarah; Reznick, Leah; Lombardi, Lorinna; Parikh, Mansi; Chamberlain, Winston; Yackel, Thomas R.; Chiang, Michael F.

    2016-01-01

    Clinicians today face increased patient loads, decreased reimbursements and potential negative productivity impacts of using electronic health records (EHR), but have little guidance on how to improve clinic efficiency. Discrete event simulation models are powerful tools for evaluating clinical workflow and improving efficiency, particularly when they are built from secondary EHR timing data. The purpose of this study is to demonstrate that these simulation models can be used for resource allocation decision making as well as for evaluating novel scheduling strategies in outpatient ophthalmology clinics. Key findings from this study are that: 1) secondary use of EHR timestamp data in simulation models represents clinic workflow, 2) simulations provide insight into the best allocation of resources in a clinic, 3) simulations provide critical information for schedule creation and decision making by clinic managers, and 4) simulation models built from EHR data are potentially generalizable. PMID:28269861

  11. Flux boundary conditions in particle simulations.

    PubMed

    Flekkøy, Eirik G; Delgado-Buscalioni, Rafael; Coveney, Peter V

    2005-08-01

    Flux boundary conditions are interesting in a number of contexts ranging from multiscale simulations to simulations of molecular hydrodynamics in nanoscale systems. Here we introduce, analyze, and test a general scheme to impose boundary conditions that simultaneously control the momentum and energy flux into open particle systems The scheme is shown to handle far from equilibrium simulations. It acquires its main characteristics from the requirement that it fulfills the second law of thermodynamics and thus minimizes the entropy production, when it is applied to reversible processes. It is shown both theoretically and through simulations that the scheme emulates the effect of an extended particle system as far as particle number fluctuations, temperature, and density profiles are concerned. The numerical scheme is further shown to be accurate and stable in both equilibrium and far from equilibrium contexts.

  12. Lunar Polar Environmental Testing: Regolith Simulant Conditioning

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie

    2014-01-01

    As ISRU system development approaches flight fidelity, there is a need to test hardware in relevant environments. Extensive laboratory and field testing have involved relevant soil (lunar regolith simulants), but the current design iterations necessitate relevant pressure and temperature conditions. Including significant quantities of lunar regolith simulant in a thermal vacuum chamber poses unique challenges. These include facility operational challenges (dust tolerant hardware) and difficulty maintaining a pre-prepared soil state during pump down (consolidation state, moisture retention).For ISRU purposes, the regolith at the lunar poles will be of most interest due to the elevated water content. To test at polar conditions, the regolith simulant must be doped with water to an appropriate percentage and then chilled to cryogenic temperatures while exposed to vacuum conditions. A 1m tall, 28cm diameter bin of simulant was developed for testing these simulant preparation and drilling operations. The bin itself was wrapped with liquid nitrogen cooling loops (100K) so that the simulant bed reached an average temperature of 140K at vacuum. Post-test sampling was used to determine desiccation of the bed due to vacuum exposure. Depth dependent moisture data is presented from frozen and thawed soil samples.Following simulant only evacuation tests, drill hardware was incorporated into the vacuum chamber to test auguring techniques in the frozen soil at thermal vacuum conditions. The focus of this testing was to produce cuttings piles for a newly developed spectrometer to evaluate. This instrument, which is part of the RESOLVE program science hardware, detects water signatures from surface regolith. The drill performance, behavior of simulant during drilling, and characteristics of the cuttings piles will be offered.

  13. The Impact of Human Patient Simulation on Nursing Clinical Knowledge

    ERIC Educational Resources Information Center

    Shinnick, Mary Ann

    2010-01-01

    Public health relies on well trained nurses and clinical experience is an important component of that training. However, clinical experience training for student nurses also has significant challenges, as it can place patients at risk. Also it is difficult to schedule/predict patient conditions and procedures. Human patient simulation (HPS) can…

  14. Computer Clinical Simulations in Health Sciences.

    ERIC Educational Resources Information Center

    Jones, Gary L; Keith, Kenneth D.

    1983-01-01

    Discusses the key characteristics of clinical simulation, some developmental foundations, two current research studies, and some implications for the future of health science education. Investigations of the effects of computer-based simulation indicate that acquisition of decision-making skills is greater than with noncomputerized simulations.…

  15. Conditional simulations for fields of extreme precipitation

    NASA Astrophysics Data System (ADS)

    Bechler, Aurélien; Vrac, Mathieu; Bel, Liliane

    2014-05-01

    Many environmental models, such as hydrological models, require input data, e.g. precipitation values, correctly simulated and distributed, even at locations where no observation is available. This is particularly true for extreme events that may be of high importance for impact studies. The last decade has seen max-stable processes emerge as a powerful tool for the statistical modeling of spatial extremes. Recently, such processes have been used in climate context to perform simulations at ungauged sites based on empirical distributions of a spatial field conditioned by observed values in some locations. In this work conditional simulations of extremal t process are investigated, taking benefits of its spectral construction. The methodology of conditional simulations proposed by Dombry et al. [2013] for Brown-Resnick and Schlather models is adapted for the extremal t process with some improvements which enlarge the possible number of conditional points. A simulation study enables to highlight the role of the different parameters of the model and to emphasize the importance of the steps of the algorithm. In this work, we focus on the French Mediterranean basin, which is a key spot of occurrences of meteorological extremes such as heavy precipitation. Indeed, major extreme precipitation are regularly observed in this region near the 'cévenol" mountains. The modeling and the understanding of these extreme precipitation - the so-called 'cévenol events" - are of major importance for hydrological studies in this complex terrain since they often trigger major floods in this region. The application of our methodology on real data in this region shows that the model and the algorithm perform well provided the stationary assumptions are fulfilled.

  16. Numerical simulation and nasal air-conditioning

    PubMed Central

    Keck, Tilman; Lindemann, Jörg

    2011-01-01

    Heating and humidification of the respiratory air are the main functions of the nasal airways in addition to cleansing and olfaction. Optimal nasal air conditioning is mandatory for an ideal pulmonary gas exchange in order to avoid desiccation and adhesion of the alveolar capillary bed. The complex three-dimensional anatomical structure of the nose makes it impossible to perform detailed in vivo studies on intranasal heating and humidification within the entire nasal airways applying various technical set-ups. The main problem of in vivo temperature and humidity measurements is a poor spatial and time resolution. Therefore, in vivo measurements are feasible only to a restricted extent, solely providing single temperature values as the complete nose is not entirely accessible. Therefore, data on the overall performance of the nose are only based on one single measurement within each nasal segment. In vivo measurements within the entire nose are not feasible. These serious technical issues concerning in vivo measurements led to a large number of numerical simulation projects in the last few years providing novel information about the complex functions of the nasal airways. In general, numerical simulations merely calculate predictions in a computational model, e.g. a realistic nose model, depending on the setting of the boundary conditions. Therefore, numerical simulations achieve only approximations of a possible real situation. The aim of this review is the synopsis of the technical expertise on the field of in vivo nasal air conditioning, the novel information of numerical simulations and the current state of knowledge on the influence of nasal and sinus surgery on nasal air conditioning. PMID:22073112

  17. Simulation of hydrocephalus condition in infant head

    NASA Astrophysics Data System (ADS)

    Wijayanti, Erna; Arif, Idam

    2014-03-01

    Hydrocephalus is a condition of an excessive of cerebrospinal fluid in brain. In this paper, we try to simulate the behavior of hydrocephalus conditions in infant head by using a hydro-elastic model which is combined with orthotropic elastic skull and with the addition of suture that divide the skull into two lobes. The model then gives predictions for the case of stenosis aqueduct by varying the cerebral aqueduct diameter, time constant and brain elastic modulus. The hydrocephalus condition which is shown by the significant value of ventricle displacement, as the result shows, is occurred when the aqueduct is as resistant as brain parenchyma for the flow of cerebrospinal fluid. The decrement of brain elastic modulus causes brain parenchyma displacement value approach ventricle displacement value. The smaller of time constant value causes the smaller value of ventricle displacement.

  18. Assessment of Clinical Skills Using Simulator Technologies

    ERIC Educational Resources Information Center

    Srinivasan, Malathi; Hwang, Judith C.; West, Daniel; Yellowlees, Peter M.

    2006-01-01

    Objective: Simulation technologies are used to assess and teach competencies through the provision of reproducible stimuli. They have exceptional utility in assessing responses to clinical stimuli that occur sporadically or infrequently. In this article, the authors describe the utility of emerging simulation technologies, and discuss critical…

  19. Galena weathering under simulated calcareous soil conditions.

    PubMed

    Lara, René H; Briones, Roberto; Monroy, Marcos G; Mullet, Martine; Humbert, Bernard; Dossot, Manuel; Naja, Ghinwa M; Cruz, Roel

    2011-09-01

    Exploitation of polymetallic deposits from calcareous mining sites exposes galena and others sulfides to weathering factors. Galena weathering leads to the formation of lead phases (e.g., PbSO(4), PbCO(3)) with a higher bioaccessibility than galena, thus increasing the mobility and toxicity of lead. Despite the environmental impacts of these lead phases, the mechanisms of galena oxidation and the transformation of lead secondary phases, under neutral-alkaline carbonated conditions, have rarely been studied. In this work, an experimental approach, combining electrochemical and spectroscopic techniques, was developed to examine the interfacial processes involved in the galena weathering under simulated calcareous conditions. The results showed an initial oxidation stage with the formation of an anglesite-like phase leading to the partial mineral passivation. Under neutral-alkaline carbonated conditions, the stability of this phase was limited as it transformed into a cerussite-like one. Based on the surface characterization and the formation of secondary species, the weathering mechanisms of galena in calcareous soil and its environmental implications were suggested.

  20. Biogeochemical Reactions Under Simulated Europa Ocean Conditions

    NASA Astrophysics Data System (ADS)

    Amashukeli, X.; Connon, S. A.; Gleeson, D. F.; Kowalczyk, R. S.; Pappalardo, R. T.

    2007-12-01

    Galileo data have demonstrated the probable presence of a liquid water ocean on Europa, and existence of salts and carbon dioxide in the satellite's surface ice (e.g., Carr et al., 1998; McCord et al., 1999, Pappalardo et al., 1999; Kivelson et al., 2000). Subsequently, the discovery of chemical signatures of extinct or extant life in Europa's ocean and on its surface became a distinct possibility. Moreover, understanding of Europa's potential habitability is now one of the major goals of the Europa Orbiter Flagship mission. It is likely, that in the early stages of Europa's ocean formation, moderately alkaline oceanic sulfate-carbonate species and a magnetite-silicate mantel could have participated in low-temperature biogeochemical sulfur, iron and carbon cycles facilitated by primitive organisms (Zolotov and Shock, 2004). If periodic supplies of fresh rock and sulfate-carbonate ions are available in Europa's ocean, then an exciting prospect exists that life may be present in Europa's ocean today. In our laboratory, we began the study of the plausible biogeochemical reactions under conditions appropriate to Europa's ocean using barophilic psychrophilic organisms that thrive under anaerobic conditions. In the near absence of abiotic synthetic pathways due to low Europa's temperatures, the biotic synthesis may present a viable opportunity for the formation of the organic and inorganic compounds under these extreme conditions. This work is independent of assumptions regarding hydrothermal vents at Europa's ocean floor or surface-derived oxidant sources. For our studies, we have fabricated a high-pressure (5,000 psi) reaction vessel that simulates aqueous conditions on Europa. We were also successful at reviving barophilic psychrophilic strains of Shewanella bacterium, which serve as test organisms in this investigation. Currently, facultative barophilic psychrophilic stains of Shewanella are grown in the presence of ferric food source; the strains exhibiting iron

  1. Neutral Chemistry in Titan's Ionospheric Simulated Conditions

    NASA Astrophysics Data System (ADS)

    Dubois, David; Carrasco, Nathalie; Petrucciani, Marie; Tigrine, Sarah; Vettier, Ludovic

    2016-10-01

    Titan's atmospheric gas phase chemistry leading to the formation of organic aerosols can be simulated in laboratory experiments. Typically, plasma reactors can be used to achieve Titan-like conditions. Such a discharge induces dissociation and ionization processes to the N2-CH4 mixture by electron impact. This faithfully reproduces the electron energy range of magnetospheric electrons entering Titan's atmosphere and can also approximate the solar UV input at Titan's ionosphere. In this context, it is deemed necessary to apply and exploit such a technique in order to better understand the chemical reactivity occurring in Titan-like conditions.In the present work, we use the PAMPRE cold dusty plasma experiment with an N2-CH4 gaseous mixture under controlled pressure and gas influx, hence, emphasizing on the gas phase which we know is key to the formation of aerosols on Titan. Besides, an internal cryogenic trap has been developed to accumulate the gas products during their formation and facilitate their detection. These products are identified and quantified by in situ mass spectroscopy and Fourier-Transform Infrared Spectroscopy. We present here results from this experiment in two experimental conditions: 90-10% and 99-1% N2-CH4 mixing ratios respectively. We use a quantitative approach on nitriles and polycyclic aromatic hydrocarbons.Key organic compounds reacting with each other are thus detected and quantified in order to better follow the chemistry occuring in the gas phase of Titan-like conditions. Indeed, these species acting as precursors to the solid phase are assumed to be relevant in the formation of Titan's organic aerosols. These organic aerosols are what make up Titan's hazy atmosphere.

  2. Clinical examination simulation: getting to real.

    PubMed

    Salud, Lawrence H; Ononye, Chiagozie I; Kwan, Calvin; Salud, Jonathan C; Pugh, Carla M

    2012-01-01

    Verschuren and Hartog's six-stage methodology for design-oriented research is a process that is ideally suited to the development of artifacts that meet a desired outcome. We discuss the methodology and its relevance to simulation development for establishing a wide variety of realistic clinical breast examination models that can be used for assessment.

  3. [Gastric adenomyoma clinically simulating hypertrophic pyloric stenosis].

    PubMed

    Sánchez García, S; Rubio Solís, D; Anes González, G; González Sánchez, S

    2016-01-01

    Gastric adenomyomas are extremely uncommon benign tumors in children. On histologic examination, these tumors have an epithelial component similar to pancreatic ducts. We present a case of a pyloric adenomyoma that clinically simulated hypertrophic pyloric stenosis in a newborn girl. Imaging tests, fundamentally magnetic resonance imaging, were very important in the characterization and diagnosis of this entity.

  4. Characteristics of Effective Clinical Teachers in Simulated Clinical Experiences Compared to Traditional Clinical Experiences

    ERIC Educational Resources Information Center

    Sieh-Bliss, Selina

    2014-01-01

    While there is evidence in the literature measuring effective clinical teacher characteristics in traditional experiences, little is known of effective characteristics expected from clinical teachers during simulated clinical experiences. This study examined which clinical teaching behaviors and characteristics are perceived by nursing students'…

  5. Mathematical simulation of power conditioning systems. Volume 1: Simulation of elementary units. Report on simulation methodology

    NASA Technical Reports Server (NTRS)

    Prajous, R.; Mazankine, J.; Ippolito, J. C.

    1978-01-01

    Methods and algorithms used for the simulation of elementary power conditioning units buck, boost, and buck-boost, as well as shunt PWM are described. Definitions are given of similar converters and reduced parameters. The various parts of the simulation to be carried out are dealt with; local stability, corrective network, measurements of input-output impedance and global stability. A simulation example is given.

  6. 42 CFR 484.48 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition of participation: Clinical records. 484....48 Condition of participation: Clinical records. A clinical record containing pertinent past and... information; name of physician; drug, dietary, treatment, and activity orders; signed and dated clinical...

  7. Organic degradation under simulated Martian conditions.

    PubMed

    Stoker, C R; Bullock, M A

    1997-05-25

    We report on laboratory experiments which simulate the breakdown of organic compounds under Martian surface conditions. Chambers containing Mars-analog soil mixed with the amino acid glycine were evacuated and filled to 100 mbar pressure with a Martian atmosphere gas mixture and then irradiated with a broad spectrum Xe lamp. Headspace gases were periodically withdrawn and analyzed via gas chromatography for the presence of organic gases expected to be decomposition products of the glycine. The quantum efficiency for the decomposition of glycine by light at wavelengths from 2000 to 2400 angstroms was measured to be 1.46 +/- 1.0 x 10(-6) molecules/photon. Scaled to Mars, this represents an organic destruction rate of 2.24 +/- 1.2 x 10(-4) g of C m-2 yr-1. We compare this degradation rate with the rate that organic compounds are brought to Mars as a result of meteoritic infall to show that organic compounds are destroyed on Mars at rates far exceeding the rate that they are deposited by meteorites. Thus the fact that no organic compounds were found on Mars by the Viking Lander Gas Chromatograph Mass Spectrometer experiment can be explained without invoking the presence of strong oxidants in the surface soils. The organic destruction rate may be considered as an upper bound for the globally averaged biomass production rate of extant organisms at the surface of Mars. This upper bound is comparable to the slow growing cryptoendolithic microbial communities found in dry Antarctica deserts. Finally, comparing these organic destruction rates to recently reported experiments on the stability of carbonate on the surface of Mars, we find that organic compounds may currently be more stable than calcite.

  8. [Clinical evaluation of oxypertine in anxiety conditions].

    PubMed

    Somohano, M D; Broissin, M C; Sobrino Z, A

    1976-01-01

    suspended the treatment when placebo was to be substituted. In this same group, six cases initiated treatment with oxypertine, and after two weeks or more the medication was changed to placebo due to the same reasons mentioned above. Results were fair in one and poor in five. A significant response was observed in those cases where oxypertine replaced placebo and no response was obtained when placebo substituted oxypertine. Few cases abandoned mainly for two reasons: satisfactory remission of the anxiety or symptoms exacerbation. Investigators emphasize that the psychological conditions of the patients studied in this trial were different from the ones who ordinarily assist to the out patient clinics or private practice, mainly because were subjects with legal and social problems, as already mentioned, confined in a rehabilitation center. The conclusion of the stldy is that the administration of oxpertine at the dosage of 20 mg to patients with severe anxiety and with the special conditions mentioned above, provides a relative anxiolytic effect.

  9. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 3 2011-10-01 2011-10-01 false Condition of participation: Clinical records. 418.104 Section 418.104 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND... Environment § 418.104 Condition of participation: Clinical records. A clinical record containing past...

  10. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 3 2014-10-01 2014-10-01 false Condition of participation: Clinical records. 418.104 Section 418.104 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...: Organizational Environment § 418.104 Condition of participation: Clinical records. A clinical record...

  11. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Condition of participation: Clinical records. 418.104 Section 418.104 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...: Organizational Environment § 418.104 Condition of participation: Clinical records. A clinical record...

  12. 42 CFR 493.1225 - Condition: Clinical cytogenetics.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Clinical cytogenetics. 493.1225 Section... Testing § 493.1225 Condition: Clinical cytogenetics. If the laboratory provides services in the specialty of Clinical cytogenetics, the laboratory must meet the requirements specified in §§ 493.1230...

  13. 42 CFR 485.60 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition of participation: Clinical records. 485... of participation: Clinical records. The facility must maintain clinical records on all patients in accordance with accepted professional standards and practice. The clinical records must be...

  14. Space conditioning performance analysis and simulation study

    NASA Astrophysics Data System (ADS)

    Patani, A.; Bonne, U.

    1981-07-01

    The engine driven heat pump model was expanded to incorporate an approach for evaluating the influence of cycling and systems included the sensitivity of performance to electric consumption, compressor speed, mixing, and climate. A modular program for evaluating the steady state performance of absorption heat pumps was developed. Initial simulations indicated performance trends as a function of outdoor temperature and the refrigerant absorber charge. The combustion heating system model, HFLAME, was used to simulate the benefits of fan/pump overrun and the dependence of corresponding setpoints on off period losses and electric costs. Benefits of fuel, fuel/air modulation as compared to cyclic performance were also analyzed. An energy distribution factor was defined to describe the effect of the distribution system on realizing savings of retrofits.

  15. [Psychopathologic characteristics of conditions simulating spinal diseases].

    PubMed

    Ostroglazov, V G; Lisina, M A

    1989-01-01

    Combined investigation of 27 patients with unclear pathological states in a vertebral pathology unit yielded a description of a type of concealed mental pathology. A complex of three major determinants of the patients' state was detected: pathological hypochondric notions of delirious or hallucinatory type, psychosensory and psychomotor disorders. The latter were prevalent in clinical picture suggesting the vertebral pathology and thus leading to misdiagnosis of vertebral disorders.

  16. [Clinical condition and therapy of bone diseases].

    PubMed

    Miura, Kohji; Oznono, Keiichi

    2013-12-01

    Skeletal dysplasia is the term which represents disorders including growth and differentiation of bone, cartilage and ligament. A lot of diseases are included, and new disorders have been added. However, the therapy of most bone diseases is less well-established. Achondroplasia, hypochondroplasia, and osteogenesis imperfecta are most frequent bone diseases. There is no curative treatment for these diseases, however, supportive therapies are available ; for example, growth-hormone therapy for achondroplasia and hypochondroplasia, and bisphosphonate therapy for osteogenesis imperfecta. In addition, enzyme replacement therapy for hypophosphatasia is now on clinical trial.

  17. Graphite Oxidation Simulation in HTR Accident Conditions

    SciTech Connect

    El-Genk, Mohamed

    2012-10-19

    Massive air and water ingress, following a pipe break or leak in steam-generator tubes, is a design-basis accident for high-temperature reactors (HTRs). Analysis of these accidents in both prismatic and pebble bed HTRs requires state-of-the-art capability for predictions of: 1) oxidation kinetics, 2) air helium gas mixture stratification and diffusion into the core following the depressurization, 3) transport of multi-species gas mixture, and 4) graphite corrosion. This project will develop a multi-dimensional, comprehensive oxidation kinetics model of graphite in HTRs, with diverse capabilities for handling different flow regimes. The chemical kinetics/multi-species transport model for graphite burning and oxidation will account for temperature-related changes in the properties of graphite, oxidants (O2, H2O, CO), reaction products (CO, CO2, H2, CH4) and other gases in the mixture (He and N2). The model will treat the oxidation and corrosion of graphite in geometries representative of HTR core component at temperatures of 900°C or higher. The developed chemical reaction kinetics model will be user-friendly for coupling to full core analysis codes such as MELCOR and RELAP, as well as computational fluid dynamics (CFD) codes such as CD-adapco. The research team will solve governing equations for the multi-dimensional flow and the chemical reactions and kinetics using Simulink, an extension of the MATLAB solver, and will validate and benchmark the model's predictions using reported experimental data. Researchers will develop an interface to couple the validated model to a commercially available CFD fluid flow and thermal-hydraulic model of the reactor , and will perform a simulation of a pipe break in a prismatic core HTR, with the potential for future application to a pebble-bed type HTR.

  18. Clinical Inquiry. Does turmeric relieve inflammatory conditions?

    PubMed

    White, Brett; Judkins, Dolores Zegar

    2011-03-01

    Yes, but data aren't plentiful. Limited evidence suggests that turmeric and its active compound, curcumin, are effective for rheumatoid arthritis and other inflammatory conditions (strength of recommendation [SOR]: C, primarily low-quality cohort studies with small patient numbers). Curcumin has shown limited benefit for patients with psoriasis, inflammatory bowel disease (IBS), inflammatory eye diseases, familial adenomatous polyposis, and kidney transplantation (SOR: B, small, short randomized controlled trials [RCTs]). No evidence indicates that curcumin helps patients with human immunodeficiency virus (HIV) (SOR: B, single RCT).

  19. Preignition Characteristics of Several Fuels Under Simulated Engine Conditions

    NASA Technical Reports Server (NTRS)

    Spencer, R C

    1941-01-01

    The preignition characteristics of a number of fuels have been studied under conditions similar to those encountered in an engine. These conditions were simulated by suddenly compressing a fuel-air mixture in contact with an electrically heated hot spot in the cylinder head of the NACA combustion apparatus. Schlieren photographs and indicator cards were taken of the burning, and the hot-spot temperatures necessary to cause ignition under various conditions were determined.

  20. The apparatus "Photostat-I" for simulating Martian environmental conditions.

    PubMed

    Zaar, E I; Zelikson, V G; Kitaigorodsky, M G; Lozina-Lozinsky, L K; Koshelev, G V; Rybin, M A

    1970-01-01

    One of the main tasks of exobiology is to determine conditions required for life on different planets of our solar system. At present, experimental ecological methods permitting the study of responses of living systems to extreme influences and, in particular, to simulated environmental Martian conditions, are widely used. To study the reaction of Earth organisms, special chambers and mechanisms are used which allow the modelling of conditions different from ours, mainly Martian. Existing devices capable of simulating the Martian environment. Our apparatus "Photostat-I" permits the simulation of pressure and visible light illumination (up to 60,000 lux), the irradiation of biological objectives in UV light (220-400 nm) and the production of a daily temperature cycle typical of Mars with a high degree of accuracy.

  1. DSMC Simulations of Apollo Capsule Aerodynamics for Hypersonic Rarefied Conditions

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Glass, Christopher E.; Greene, Francis A.

    2006-01-01

    Direct simulation Monte Carlo DSMC simulations are performed for the Apollo capsule in the hypersonic low density transitional flow regime. The focus is on ow conditions similar to that experienced by the Apollo Command Module during the high altitude portion of its reentry Results for aerodynamic forces and moments are presented that demonstrate their sensitivity to rarefaction that is for free molecular to continuum conditions. Also aerodynamic data are presented that shows their sensitivity to a range of reentry velocity encompasing conditions that include reentry from low Earth orbit lunar return and Mars return velocities to km/s. The rarefied results are anchored in the continuum regime with data from Navier Stokes simulations

  2. Extremophiles survival to simulated space conditions: an astrobiology model study.

    PubMed

    Mastascusa, V; Romano, I; Di Donato, P; Poli, A; Della Corte, V; Rotundi, A; Bussoletti, E; Quarto, M; Pugliese, M; Nicolaus, B

    2014-09-01

    In this work we investigated the ability of four extremophilic bacteria from Archaea and Bacteria domains to resist to space environment by exposing them to extreme conditions of temperature, UV radiation, desiccation coupled to low pressure generated in a Mars' conditions simulator. All the investigated extremophilic strains (namely Sulfolobus solfataricus, Haloterrigena hispanica, Thermotoga neapolitana and Geobacillus thermantarcticus) showed a good resistance to the simulation of the temperature variation in the space; on the other hand irradiation with UV at 254 nm affected only slightly the growth of H. hispanica, G. thermantarcticus and S. solfataricus; finally exposition to Mars simulated condition showed that H. hispanica and G. thermantarcticus were resistant to desiccation and low pressure.

  3. Suitable Conditions of Reservoir Simulation for Searching Rule Curves

    NASA Astrophysics Data System (ADS)

    Kangrang, Anongrit; Chaleeraktrakoon, Chavalit

    The objective of this study is to carry out a suitable length of inflow record using in the simulation model. The second objective is to find an effect of initial reservoir capacity of reservoir simulation for searching the optimal rule curves. The reservoir simulation model was connected with genetic algorithms to search the optimal rule curves quickly. The model has been applied to determine the optimal rule curves of the Bhumibol and Sirikit Reservoirs (the Chao Phraya River Basin, Thailand). The optimal rule curves of each condition were used to assess by a Monte Carlo simulation. The results show that the shortest period of dry inflow record using in the simulation model in order to search the optimal rule curves is 10 year. Furthermore, the minimum initial capacity of reservoir for searching optimal rule curves is 10% of full capacity.

  4. Protection of chemolithoautotrophic bacteria exposed to simulated Mars environmental conditions

    NASA Astrophysics Data System (ADS)

    Gómez, Felipe; Mateo-Martí, Eva; Prieto-Ballesteros, Olga; Martín-Gago, Jose; Amils, Ricardo

    2010-10-01

    Current surface conditions (strong oxidative atmosphere, UV radiation, low temperatures and xeric conditions) on Mars are considered extremely challenging for life. The question is whether there are any features on Mars that could exert a protective effect against the sterilizing conditions detected on its surface. Potential habitability in the subsurface would increase if the overlaying material played a protective role. With the aim of evaluating this possibility we studied the viability of two microorganisms under different conditions in a Mars simulation chamber. An acidophilic chemolithotroph isolated from Río Tinto belonging to the Acidithiobacillus genus and Deinococcus radiodurans, a radiation resistant microorganism, were exposed to simulated Mars conditions under the protection of a layer of ferric oxides and hydroxides, a Mars regolith analogue. Samples of these microorganisms were exposed to UV radiation in Mars atmospheric conditions at different time intervals under the protection of 2 and 5 mm layers of oxidized iron minerals. Viability was evaluated by inoculation on fresh media and characterization of their growth cultures. Here we report the survival capability of both bacteria to simulated Mars environmental conditions.

  5. Anticipatory postural adjustments in conditions of simulated reduced gravity.

    PubMed

    Li, Xiaoyan; Aruin, Alexander S

    2008-11-01

    The study investigates the role of decreased gravity on anticipatory postural adjustments (APAs). Subjects performed fast bilateral arm-raising movements and load releases while in conditions of normal and reduced gravity. Reduced gravity conditions were simulated by changing the ratio between the body weight and mass. Electromyographic (EMG) activity of dorsal and ventral trunk and leg muscles, as well as ground reaction forces, were recorded and quantified within the time intervals typical of APAs. Anticipatory postural adjustments were seen in normal gravity conditions as well as in simulated reduced gravity conditions. However, in decreased gravity conditions, the magnitudes of the anticipatory integrals of electromyography muscle activity (EMG) were smaller compared to normal gravity. Moreover, there was a linear relation between EMG and simulated decreased gravity and between the displacement of the center of pressure (COP) and simulated gravity. The study provides new data on the effect of gravity in feed-forward postural control and stresses the importance of taking into consideration its role in the control of upright posture.

  6. The accuracy of linear measurements of maxillary and mandibular edentulous sites in cone-beam computed tomography images with different fields of view and voxel sizes under simulated clinical conditions

    PubMed Central

    Ramesh, Aruna; Pagni, Sarah

    2016-01-01

    Purpose The objective of this study was to investigate the effect of varying resolutions of cone-beam computed tomography images on the accuracy of linear measurements of edentulous areas in human cadaver heads. Intact cadaver heads were used to simulate a clinical situation. Materials and Methods Fiduciary markers were placed in the edentulous areas of 4 intact embalmed cadaver heads. The heads were scanned with two different CBCT units using a large field of view (13 cm×16 cm) and small field of view (5 cm×8 cm) at varying voxel sizes (0.3 mm, 0.2 mm, and 0.16 mm). The ground truth was established with digital caliper measurements. The imaging measurements were then compared with caliper measurements to determine accuracy. Results The Wilcoxon signed rank test revealed no statistically significant difference between the medians of the physical measurements obtained with calipers and the medians of the CBCT measurements. A comparison of accuracy among the different imaging protocols revealed no significant differences as determined by the Friedman test. The intraclass correlation coefficient was 0.961, indicating excellent reproducibility. Inter-observer variability was determined graphically with a Bland-Altman plot and by calculating the intraclass correlation coefficient. The Bland-Altman plot indicated very good reproducibility for smaller measurements but larger discrepancies with larger measurements. Conclusion The CBCT-based linear measurements in the edentulous sites using different voxel sizes and FOVs are accurate compared with the direct caliper measurements of these sites. Higher resolution CBCT images with smaller voxel size did not result in greater accuracy of the linear measurements. PMID:27358816

  7. Clinical Audit of Gastrointestinal Conditions Occurring among Adults with Down Syndrome Attending a Specialist Clinic

    ERIC Educational Resources Information Center

    Wallace, Robyn A.

    2007-01-01

    Background: Adults with Down syndrome (DS) are predisposed to syndromic and environmental gastrointestinal conditions. Method: In a hospital-based clinic for adults with DS, a chart audit was conducted to assess the range and frequency of gastrointestinal conditions. Results: From January 2003 to March 2005, 57 patients attended the clinic,…

  8. Phase Distribution Phenomena for Simulated Microgravity Conditions: Experimental Work

    NASA Technical Reports Server (NTRS)

    Singhal, Maneesh; Bonetto, Fabian J.; Lahey, R. T., Jr.

    1996-01-01

    This report summarizes the work accomplished at Rensselaer to study phase distribution phenomenon under simulated microgravity conditions. Our group at Rensselaer has been able to develop sophisticated analytical models to predict phase distribution in two-phase flows under a variety of conditions. These models are based on physics and data obtained from carefully controlled experiments that are being conducted here. These experiments also serve to verify the models developed.

  9. Phase Distribution Phenomena for Simulated Microgravity Conditions: Experimental Work

    NASA Technical Reports Server (NTRS)

    Singhal, Maneesh; Bonetto, Fabian J.; Lahey, R. T., Jr.

    1996-01-01

    This report summarizes the work accomplished at Rensselaer to study phase distribution phenomenon under simulated microgravity conditions. Our group at Rensselaer has been able to develop sophisticated analytical models to predict phase distribution in two-phase flows under variety of conditions. These models are based on physics and data obtained from carefully controlled experiments that are being conducted here. These experiments also serve to verify the models developed.

  10. Potentially reversible conditions in 1000 consecutive memory clinic patients

    PubMed Central

    Hejl, A; Hogh, P; Waldemar, G

    2002-01-01

    Objectives: To investigate the prevalence and classification of potentially reversible conditions in a prospective memory clinic cohort of younger and elderly patients with cognitive symptoms. Patients: 1000 consecutive patients referred during a period of 54 months to a university hospital multidisciplinary memory clinic based in neurology. Methods: All patients were referred for diagnostic evaluation and treatment of cognitive symptoms. The multidisciplinary staff prospectively established a standardised consensus report for each patient based on the results of clinical and ancillary investigations with classification of cognitive profile, primary underlying cause, and concomitant conditions. Results: The mean age of the patients was 66.1 years (range 17–98) and 43% met diagnostic criteria for dementia. A potentially reversible primary aetiology for cognitive symptoms was identified in 19% and a potentially reversible concomitant condition in 23% of all patients. In the subgroup of patients with dementia, 4% had a potentially reversible primary aetiology. Careful clinical examination, routine laboratory tests, and cranial computed tomography identified most of these conditions. Conclusions: Reversible conditions are most often encountered in patients with mild cognitive disturbances. Although treatment may not always result in full reversal of cognitive symptoms, potentially reversible conditions should be identified in the diagnostic evaluation of the patient. PMID:12235305

  11. Analysis of Boundary Conditions for Crystal Defect Atomistic Simulations

    NASA Astrophysics Data System (ADS)

    Ehrlacher, V.; Ortner, C.; Shapeev, A. V.

    2016-12-01

    Numerical simulations of crystal defects are necessarily restricted to finite computational domains, supplying artificial boundary conditions that emulate the effect of embedding the defect in an effectively infinite crystalline environment. This work develops a rigorous framework within which the accuracy of different types of boundary conditions can be precisely assessed. We formulate the equilibration of crystal defects as variational problems in a discrete energy space and establish qualitatively sharp regularity estimates for minimisers. Using this foundation we then present rigorous error estimates for (i) a truncation method (Dirichlet boundary conditions), (ii) periodic boundary conditions, (iii) boundary conditions from linear elasticity, and (iv) boundary conditions from nonlinear elasticity. Numerical results confirm the sharpness of the analysis.

  12. Activity of sulfate-reducing bacteria under simulated reservoir conditions

    SciTech Connect

    Rosnes, J.T.; Graue, A.; Lien, T. )

    1991-05-01

    This paper reports on sulfate-reducing bacteria (SRB) that have been isolated from hot oilfield waters from subsea oil reservoirs in the North Sea. Experiments with these bacteria in a reservoir simulator indicate that SRB may maintain their activity in the conditions found in most North Sea reservoirs and, if precautions are not taken, may contribute to souring of the oil and gas.

  13. Fabric Force Sensors for the Clinical Breast Examination Simulator

    PubMed Central

    LAUFER, Shlomi; RASSKE, Kristen; STOPFER, Lauren; KURZYNSKI, Clair; ABBOTT, Tim; PLATNER, Megan; TOWLES, Joseph; PUGH, Carla M

    2016-01-01

    Sensor enabled simulators may help in training and assessing clinical skill. Their are imitations on the locations current sensors can be placed without interfering with the clinical examination. In this study novel fabric force sensors were developed and tested. These sensors are soft and flexible and undetectable when placed in different locations in the simulator. Five sensors were added to our current sensor enabled breast simulator. Eight participants performed the clinical breast examination on the simulator and documented their findings. There was a significant relationship for both clinical breast examination time (r(6) = 0.99, p < 0.001 ) and average force (r(6) = 0.92, p < 0.005) between our current sensors and the new fabric sensors. In addition the senors were not noticed by the participants. These new sensors provide new methods to measure and assess clinical skill and performance. PMID:27046577

  14. Application of nitric oxide measurements in clinical conditions beyond asthma

    PubMed Central

    Malinovschi, Andrei; Ludviksdottir, Dora; Tufvesson, Ellen; Rolla, Giovanni; Bjermer, Leif; Alving, Kjell; Diamant, Zuzana

    2015-01-01

    Fractional exhaled nitric oxide (FeNO) is a convenient, non-invasive method for the assessment of active, mainly Th2-driven, airway inflammation, which is sensitive to treatment with standard anti-inflammatory therapy. Consequently, FeNO serves as a valued tool to aid diagnosis and monitoring in several asthma phenotypes. More recently, FeNO has been evaluated in several other respiratory, infectious, and/or immunological conditions. In this short review, we provide an overview of several clinical studies and discuss the status of potential applications of NO measurements in clinical conditions beyond asthma. PMID:26672962

  15. Stochastic Simulation of Microseisms Using Theory of Conditional Random Fields

    NASA Astrophysics Data System (ADS)

    Morikawa, H.; Akamatsu, J.; Nishimura, K.; Onoue, K.; Kameda, H.

    -We examine the applicability of conditional stochastic simulation to interpretation of microseisms observed on soft soil sediments at Kushiro, Hokkaido, Japan. The theory of conditional random fields developed by Kameda and Morikawa (1994) is used, which allows one to perform interpolation of a Gaussian stochastic time-space field that is conditioned by realized values of time functions specified at some discrete locations. The applicability is examined by a blind test, that is, by comparing a set of simulated seismograms and recorded ones obtained from three-point array observa tions. A test of fitness was performed by means of the sign test. It is concluded that the method is applicable to interpretation of microseisms, and that the wave field of microseisms can be treated as Gaussian random fields both in time and space.

  16. Periodic boundary conditions for dislocation dynamics simulations in three dimensions

    SciTech Connect

    Bulatov, V V; Rhee, M; Cai, W

    2000-11-20

    This article presents an implementation of periodic boundary conditions (PBC) for Dislocation Dynamics (DD) simulations in three dimensions (3D). We discuss fundamental aspects of PBC development, including preservation of translational invariance and line connectivity, the choice of initial configurations compatible with PBC and a consistent treatment of image stress. On the practical side, our approach reduces to manageable proportions the computational burden of updating the long-range elastic interactions among dislocation segments. The timing data confirms feasibility and practicality of PBC for large-scale DD simulations in 3D.

  17. 42 CFR 484.48 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Condition of participation: Clinical records. 484.48 Section 484.48 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION HOME HEALTH SERVICES Furnishing of Services §...

  18. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM HOSPICE CARE Conditions of participation: Organizational... revokes the election of hospice care, or is discharged from hospice in accordance with § 418.26, the... current findings is maintained for each hospice patient. The clinical record must contain correct...

  19. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM (CONTINUED) HOSPICE CARE Conditions of participation... revokes the election of hospice care, or is discharged from hospice in accordance with § 418.26, the... past and current findings is maintained for each hospice patient. The clinical record must...

  20. DSMC Shock Simulation of Saturn Entry Probe Conditions

    NASA Technical Reports Server (NTRS)

    Higdon, Kyle J.; Cruden, Brett A.; Brandis, Aaron; Liechty, Derek S.; Goldstein, David B.; Varghese, Philip L.

    2016-01-01

    This work describes the direct simulation Monte Carlo (DSMC) investigation of Saturn entry probe scenarios and the influence of non-equilibrium phenomena on Saturn entry conditions. The DSMC simulations coincide with rarefied hypersonic shock tube experiments of a hydrogen-helium mixture performed in the Electric Arc Shock Tube (EAST) at NASA Ames Research Center. The DSMC simulations are post-processed through the NEQAIR line-by-line radiation code to compare directly to the experimental results. Improved collision cross-sections, inelastic collision parameters, and reaction rates are determined for a high temperature DSMC simulation of a 7-species H2-He mixture and an electronic excitation model is implemented in the DSMC code. Simulation results for 27.8 and 27.4 kms shock waves are obtained at 0.2 and 0.1 Torr respectively and compared to measured spectra in the VUV, UV, visible, and IR ranges. These results confirm the persistence of non-equilibrium for several centimeters behind the shock and the diffusion of atomic hydrogen upstream of the shock wave. Although the magnitude of the radiance did not match experiments and an ionization inductance period was not observed in the simulations, the discrepancies indicated where improvements are needed in the DSMC and NEQAIR models.

  1. DSMC Shock Simulation of Saturn Entry Probe Conditions

    NASA Technical Reports Server (NTRS)

    Higdon, Kyle J.; Cruden, Brett A.; Brandis, Aaron M.; Liechty, Derek S.; Goldstein, David B.; Varghese, Philip L.

    2016-01-01

    This work describes the direct simulation Monte Carlo (DSMC) investigation of Saturn entry probe scenarios and the influence of non-equilibrium phenomena on Saturn entry conditions. The DSMC simulations coincide with rarefied hypersonic shock tube experiments of a hydrogen-helium mixture performed in the Electric Arc Shock Tube (EAST) at the NASA Ames Research Center. The DSMC simulations are post-processed through the NEQAIR line-by-line radiation code to compare directly to the experimental results. Improved collision cross-sections, inelastic collision parameters, and reaction rates are determined for a high temperature DSMC simulation of a 7-species H2-He mixture and an electronic excitation model is implemented in the DSMC code. Simulation results for 27.8 and 27.4 km/s shock waves are obtained at 0.2 and 0.1 Torr, respectively, and compared to measured spectra in the VUV, UV, visible, and IR ranges. These results confirm the persistence of non-equilibrium for several centimeters behind the shock and the diffusion of atomic hydrogen upstream of the shock wave. Although the magnitude of the radiance did not match experiments and an ionization inductance period was not observed in the simulations, the discrepancies indicated where improvements are needed in the DSMC and NEQAIR models.

  2. Piloting Augmented Reality Technology to Enhance Realism in Clinical Simulation.

    PubMed

    Vaughn, Jacqueline; Lister, Michael; Shaw, Ryan J

    2016-09-01

    We describe a pilot study that incorporated an innovative hybrid simulation designed to increase the perception of realism in a high-fidelity simulation. Prelicensure students (N = 12) cared for a manikin in a simulation lab scenario wearing Google Glass, a wearable head device that projected video into the students' field of vision. Students reported that the simulation gave them confidence that they were developing skills and knowledge to perform necessary tasks in a clinical setting and that they met the learning objectives of the simulation. The video combined visual images and cues seen in a real patient and created a sense of realism the manikin alone could not provide.

  3. Benchmarking sheath subgrid boundary conditions for macroscopic-scale simulations

    NASA Astrophysics Data System (ADS)

    Jenkins, T. G.; Smithe, D. N.

    2015-02-01

    The formation of sheaths near metallic or dielectric-coated wall materials in contact with a plasma is ubiquitous, often giving rise to physical phenomena (sputtering, secondary electron emission, etc) which influence plasma properties and dynamics both near and far from the material interface. In this paper, we use first-principles PIC simulations of such interfaces to formulate a subgrid sheath boundary condition which encapsulates fundamental aspects of the sheath behavior at the interface. Such a boundary condition, based on the capacitive behavior of the sheath, is shown to be useful in fluid simulations wherein sheath scale lengths are substantially smaller than scale lengths for other relevant physical processes (e.g. radiofrequency wavelengths), in that it enables kinetic processes associated with the presence of the sheath to be numerically modeled without explicit resolution of spatial and temporal sheath scales such as electron Debye length or plasma frequency.

  4. Simulation of Earth textures by conditional image quilting

    NASA Astrophysics Data System (ADS)

    Mahmud, K.; Mariethoz, G.; Caers, J.; Tahmasebi, P.; Baker, A.

    2014-04-01

    Training image-based approaches for stochastic simulations have recently gained attention in surface and subsurface hydrology. This family of methods allows the creation of multiple realizations of a study domain, with a spatial continuity based on a training image (TI) that contains the variability, connectivity, and structural properties deemed realistic. A major drawback of these methods is their computational and/or memory cost, making certain applications challenging. It was found that similar methods, also based on training images or exemplars, have been proposed in computer graphics. One such method, image quilting (IQ), is introduced in this paper and adapted for hydrogeological applications. The main difficulty is that Image Quilting was originally not designed to produce conditional simulations and was restricted to 2-D images. In this paper, the original method developed in computer graphics has been modified to accommodate conditioning data and 3-D problems. This new conditional image quilting method (CIQ) is patch based, does not require constructing a pattern databases, and can be used with both categorical and continuous training images. The main concept is to optimally cut the patches such that they overlap with minimum discontinuity. The optimal cut is determined using a dynamic programming algorithm. Conditioning is accomplished by prior selection of patches that are compatible with the conditioning data. The performance of CIQ is tested for a variety of hydrogeological test cases. The results, when compared with previous multiple-point statistics (MPS) methods, indicate an improvement in CPU time by a factor of at least 50.

  5. Validity and Use of Written Simulation Tests of Clinical Performance

    ERIC Educational Resources Information Center

    Palva, Ilmari P.; Korhonen, Vieno

    1976-01-01

    The outcome of a simulated clinical problem (drug-induced agranulocytosis) was compared with the outcome of similar cases in real medical service. The total performance of 100 sixth-year medical students at the end of their clerkship in internal medicine resulted in a mortality of 10 percent in the simulation exercise. (Editor/LBH)

  6. Designing Nursing Simulation Clinical Experiences to Promote Critical Inquiry

    ERIC Educational Resources Information Center

    Beattie, Bev; Koroll, Donna; Price, Susan

    2010-01-01

    The use of high fidelity simulation (HFS) learning opportunities in nursing education has received increased attention in the literature. This article describes the design of a systematic framework used to promote critical inquiry and provide meaningful simulation clinical experiences for second year nursing students. Critical inquiry, as defined…

  7. Simulation and the Development of Clinical Judgment: A Quantitative Study

    ERIC Educational Resources Information Center

    Holland, Susan

    2015-01-01

    The purpose of this quantitative pretest posttest quasi-experimental research study was to explore the effect of the NESD on clinical judgment in associate degree nursing students and compare the differences between groups when the Nursing Education Simulation Design (NESD) guided simulation in order to identify educational strategies promoting…

  8. Multiscale molecular simulations of proteins in cell-like conditions

    NASA Astrophysics Data System (ADS)

    Samiotakis, Antonios

    Proteins are the workhorses of all living organisms, performing a broad range of functions in the crowded cellular interior. However, little is known about how proteins function in cell-like conditions since most studies focus in dilute aqueous environments. In order to address this problem we incorporated molecular simulations and coarse-grained models that capture the protein dynamics in the cellular interior. We study the macromolecular crowding effects of cell-like environments on protein Borrelia Burgdorferi VlsE (variable major protein-like sequence-expressed), an aspherical membrane protein, and the enzyme Phosphoglycerate kinase. We show that protein conformation can be significantly perturbed under crowded cell-like conditions which, in turn, can have dramatic effects to the proteins' function. In addition, we look into the effects of mutations in the folding pathways of the topologically frustrated protein apoflavodoxin while correlation with experiments is also achieved. We further developed a multiscale simulation scheme that combines the sampling efficiency of low-resolution models with the detail of all-atomistic simulations. An algorithm that reconstructs all-atomistic conformations from coarse-grained representations was developed, in addition to an energy function that accounts for chemical interference based on the Boltzamn inversion method. The multiscale simulation scheme manages to sample all-atomistic structures of the protein Trp-cage that match very well with experiments. The folding kinetic behavior of Trp-cage was also studied in the combined presence of urea denaturant and macromolecular crowding.

  9. Boundary conditions for simulating large SAW devices using ANSYS.

    PubMed

    Peng, Dasong; Yu, Fengqi; Hu, Jian; Li, Peng

    2010-08-01

    In this report, we propose improved substrate left and right boundary conditions for simulating SAW devices using ANSYS. Compared with the previous methods, the proposed method can greatly reduce computation time. Furthermore, the longer the distance from the first reflector to the last one, the more computation time can be reduced. To verify the proposed method, a design example is presented with device center frequency 971.14 MHz.

  10. Exploring Iconic Interpretation and Mathematics Teacher Development through Clinical Simulations

    ERIC Educational Resources Information Center

    Dotger, Benjamin; Masingila, Joanna; Bearkland, Mary; Dotger, Sharon

    2015-01-01

    Field placements serve as the traditional "clinical" experience for prospective mathematics teachers to immerse themselves in the mathematical challenges of students. This article reports data from a different type of learning experience, that of a clinical simulation with a standardized individual. We begin with a brief background on…

  11. Improving initial conditions for cosmological N-body simulations

    NASA Astrophysics Data System (ADS)

    Garrison, Lehman H.; Eisenstein, Daniel J.; Ferrer, Douglas; Metchnik, Marc V.; Pinto, Philip A.

    2016-10-01

    In cosmological N-body simulations, the representation of dark matter as discrete `macroparticles' suppresses the growth of structure, such that simulations no longer reproduce linear theory on small scales near kNyquist. Marcos et al. demonstrate that this is due to sparse sampling of modes near kNyquist and that the often-assumed continuum growing modes are not proper growing modes of the particle system. We develop initial conditions (ICs) that respect the particle linear theory growing modes and then rescale the mode amplitudes to account for growth suppression. These ICs also allow us to take advantage of our very accurate N-body code ABACUS to implement second-order Lagrangian perturbation theory (2LPT) in configuration space. The combination of 2LPT and rescaling improves the accuracy of the late-time power spectra, halo mass functions, and halo clustering. In particular, we achieve 1 per cent accuracy in the power spectrum down to kNyquist, versus kNyquist/4 without rescaling or kNyquist/13 without 2LPT, relative to an oversampled reference simulation. We anticipate that our 2LPT will be useful for large simulations where fast Fourier transforms are expensive and that rescaling will be useful for suites of medium-resolution simulations used in cosmic emulators and galaxy survey mock catalogues. Code to generate ICs is available at https://github.com/lgarrison/zeldovich-PLT.

  12. Program Code Generator for Cardiac Electrophysiology Simulation with Automatic PDE Boundary Condition Handling

    PubMed Central

    Punzalan, Florencio Rusty; Kunieda, Yoshitoshi; Amano, Akira

    2015-01-01

    Clinical and experimental studies involving human hearts can have certain limitations. Methods such as computer simulations can be an important alternative or supplemental tool. Physiological simulation at the tissue or organ level typically involves the handling of partial differential equations (PDEs). Boundary conditions and distributed parameters, such as those used in pharmacokinetics simulation, add to the complexity of the PDE solution. These factors can tailor PDE solutions and their corresponding program code to specific problems. Boundary condition and parameter changes in the customized code are usually prone to errors and time-consuming. We propose a general approach for handling PDEs and boundary conditions in computational models using a replacement scheme for discretization. This study is an extension of a program generator that we introduced in a previous publication. The program generator can generate code for multi-cell simulations of cardiac electrophysiology. Improvements to the system allow it to handle simultaneous equations in the biological function model as well as implicit PDE numerical schemes. The replacement scheme involves substituting all partial differential terms with numerical solution equations. Once the model and boundary equations are discretized with the numerical solution scheme, instances of the equations are generated to undergo dependency analysis. The result of the dependency analysis is then used to generate the program code. The resulting program code are in Java or C programming language. To validate the automatic handling of boundary conditions in the program code generator, we generated simulation code using the FHN, Luo-Rudy 1, and Hund-Rudy cell models and run cell-to-cell coupling and action potential propagation simulations. One of the simulations is based on a published experiment and simulation results are compared with the experimental data. We conclude that the proposed program code generator can be used to

  13. Program Code Generator for Cardiac Electrophysiology Simulation with Automatic PDE Boundary Condition Handling.

    PubMed

    Punzalan, Florencio Rusty; Kunieda, Yoshitoshi; Amano, Akira

    2015-01-01

    Clinical and experimental studies involving human hearts can have certain limitations. Methods such as computer simulations can be an important alternative or supplemental tool. Physiological simulation at the tissue or organ level typically involves the handling of partial differential equations (PDEs). Boundary conditions and distributed parameters, such as those used in pharmacokinetics simulation, add to the complexity of the PDE solution. These factors can tailor PDE solutions and their corresponding program code to specific problems. Boundary condition and parameter changes in the customized code are usually prone to errors and time-consuming. We propose a general approach for handling PDEs and boundary conditions in computational models using a replacement scheme for discretization. This study is an extension of a program generator that we introduced in a previous publication. The program generator can generate code for multi-cell simulations of cardiac electrophysiology. Improvements to the system allow it to handle simultaneous equations in the biological function model as well as implicit PDE numerical schemes. The replacement scheme involves substituting all partial differential terms with numerical solution equations. Once the model and boundary equations are discretized with the numerical solution scheme, instances of the equations are generated to undergo dependency analysis. The result of the dependency analysis is then used to generate the program code. The resulting program code are in Java or C programming language. To validate the automatic handling of boundary conditions in the program code generator, we generated simulation code using the FHN, Luo-Rudy 1, and Hund-Rudy cell models and run cell-to-cell coupling and action potential propagation simulations. One of the simulations is based on a published experiment and simulation results are compared with the experimental data. We conclude that the proposed program code generator can be used to

  14. Morphea Simulating Paucibacillary Leprosy Clinically and Histopathologically

    PubMed Central

    Delgado, José Saulo Torres; Cavalcanti, Marília Lopes; Kac, Bernard Kawa; Pires, Claudia Lopes

    2013-01-01

    Clinically and histopathologically paucibacillary leprosy shows similar features with initial morphea. In this case we report a 24 yr-old male patient who presented to our dermatology department with diagnosed paucibacillary leprosy by his local dermatologist, and confirmed by perineurovascular lymphocytic infiltrate in the histopathological exam. On physical examination we found new plaque lesions that were suggestive of morphea with alteration of sensitivity. A new biopsy was performed showing sclerotic superficial dermis with thickening of the collagen bundles in deep dermis and linear arrays lymphocytic infiltrate between the collagen bundles that confirm the diagnosis of morphea. PMID:23372229

  15. Simulated Fission Gas Behavior in Silicide Fuel at LWR Conditions

    SciTech Connect

    Miao, Yinbin; Mo, Kun; Yacout, Abdellatif; Harp, Jason

    2016-09-15

    As a promising candidate for the accident tolerant fuel (ATF) used in light water reactors (LWRs), the fuel performance of uranium silicide (U3Si2) at LWR conditions needs to be well-understood. However, existing experimental post-irradiation examination (PIE) data are limited to the research reactor conditions, which involve lower fuel temperature compared to LWR conditions. This lack of appropriate experimental data significantly affects the development of fuel performance codes that can precisely predict the microstructure evolution and property degradation at LWR conditions, and therefore evaluate the qualification of U3Si2 as an AFT for LWRs. Considering the high cost, long timescale, and restrictive access of the in-pile irradiation experiments, this study aims to utilize ion irradiation to simulate the inpile behavior of the U3Si2 fuel. Both in situ TEM ion irradiation and ex situ high-energy ATLAS ion irradiation experiments were employed to simulate different types of microstructure modifications in U3Si2. Multiple PIE techniques were used or will be used to quantitatively analyze the microstructure evolution induced by ion irradiation so as to provide valuable reference for the development of fuel performance code prior to the availability of the in-pile irradiation data.

  16. Comparison of conditional bias-adjusted estimators for interim analysis in clinical trials with survival data.

    PubMed

    Shimura, Masashi; Gosho, Masahiko; Hirakawa, Akihiro

    2017-02-17

    Group sequential designs are widely used in clinical trials to determine whether a trial should be terminated early. In such trials, maximum likelihood estimates are often used to describe the difference in efficacy between the experimental and reference treatments; however, these are well known for displaying conditional and unconditional biases. Established bias-adjusted estimators include the conditional mean-adjusted estimator (CMAE), conditional median unbiased estimator, conditional uniformly minimum variance unbiased estimator (CUMVUE), and weighted estimator. However, their performances have been inadequately investigated. In this study, we review the characteristics of these bias-adjusted estimators and compare their conditional bias, overall bias, and conditional mean-squared errors in clinical trials with survival endpoints through simulation studies. The coverage probabilities of the confidence intervals for the four estimators are also evaluated. We find that the CMAE reduced conditional bias and showed relatively small conditional mean-squared errors when the trials terminated at the interim analysis. The conditional coverage probability of the conditional median unbiased estimator was well below the nominal value. In trials that did not terminate early, the CUMVUE performed with less bias and an acceptable conditional coverage probability than was observed for the other estimators. In conclusion, when planning an interim analysis, we recommend using the CUMVUE for trials that do not terminate early and the CMAE for those that terminate early. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Patient care simulations: role playing to enhance clinical understanding.

    PubMed

    Comer, Shirley K

    2005-01-01

    Role-play techniques can serve as an effective substitute for, and supplement to, simulation technology when teaching clinical nursing skills. They provide risk-free opportunities to practice clinical skills and develop clinical judgment. A two-phase patient care simulation, performed in real time, is described. Students are presented with a scenario and work cooperatively in role-playing appropriate care, with one student using a prepared script to assume the role of patient. The class functions as a resource for four students who assume the nursing role. Students reported increased understanding of course material as a result of participation in the clinical simulation scenario. Faculty observed a decreased failure rate on the corresponding course examination.

  18. Boundary conditions for direct simulations of compressible viscous flows

    NASA Technical Reports Server (NTRS)

    Poinsot, T. J.; Lele, S. K.

    1992-01-01

    The present consideration of procedures for the definition of boundary conditions for the Navier-Stokes equations emphasizes the derivation of boundary conditions that are compatible with nondissipative algorithms applicable to direct simulations of turbulent flows. A novel formulation for the Euler equations is derived on the basis of characteristic wave relations through boundaries; this formulation is generalized to the Navier-Stokes equations. The method, which applies to both sub- and supersonic flows, is used in reflecting and nonreflecting boundary-condition treatments. Attention is given to practical implementations involving inlet and outlet boundaries and slip and nonslip walls, as well as the test cases of a ducted shear layer, vortices propagating through boundaries, and Poiseuille flow.

  19. Modelling and simulation of air-conditioning cycles

    NASA Astrophysics Data System (ADS)

    Rais, Sandi; Kadono, Yoshinori; Murayama, Katsunori; Minakuchi, Kazuya; Takeuchi, Hisae; Hasegawa, Tatsuya

    2017-02-01

    The heat-pump cycle for air conditioning was investigated both numerically and experimentally by evaluating the coefficient of performance (COP) under Japanese Industrial Standard (JIS B 8619:1999) and ANSI/AHRI standard 750-2007 operating conditions. We used two expansion valve coefficients Cv_{(φ)} = 0.12 for standard operating conditions (Case 1) approaching 1.3 MPa at high pressure and 0.2 MPa at low pressure, and Cv_{(φ)} = 0.06 namely poor operating conditions (Case 2). To improve the performance of the air conditioner, we compared the performance for two outside air temperatures, 35 and 40 °C (Case 3). The simulation and experiment comparison resulted the decreasing of the COP for standard operating condition is equal to 14 %, from 3.47 to 2.95 and a decrease of the cooling capacity is equal to 18 %, from 309.72 to 253.53 W. This result was also occurred in poor operating condition which the COP was superior at 35 °C temperature.

  20. Modelling and simulation of air-conditioning cycles

    NASA Astrophysics Data System (ADS)

    Rais, Sandi; Kadono, Yoshinori; Murayama, Katsunori; Minakuchi, Kazuya; Takeuchi, Hisae; Hasegawa, Tatsuya

    2016-05-01

    The heat-pump cycle for air conditioning was investigated both numerically and experimentally by evaluating the coefficient of performance (COP) under Japanese Industrial Standard (JIS B 8619:1999) and ANSI/AHRI standard 750-2007 operating conditions. We used two expansion valve coefficients Cv_{(\\varphi )} = 0.12 for standard operating conditions (Case 1) approaching 1.3 MPa at high pressure and 0.2 MPa at low pressure, and Cv_{(\\varphi )} = 0.06 namely poor operating conditions (Case 2). To improve the performance of the air conditioner, we compared the performance for two outside air temperatures, 35 and 40 °C (Case 3). The simulation and experiment comparison resulted the decreasing of the COP for standard operating condition is equal to 14 %, from 3.47 to 2.95 and a decrease of the cooling capacity is equal to 18 %, from 309.72 to 253.53 W. This result was also occurred in poor operating condition which the COP was superior at 35 °C temperature.

  1. Clinical simulation: A method for development and evaluation of clinical information systems.

    PubMed

    Jensen, Sanne; Kushniruk, Andre W; Nøhr, Christian

    2015-04-01

    Use of clinical simulation in the design and evaluation of eHealth systems and applications has increased during the last decade. This paper describes a methodological approach for using clinical simulations in the design and evaluation of clinical information systems. The method is based on experiences from more than 20 clinical simulation studies conducted at the ITX-lab in the Capital Region of Denmark during the last 5 years. A ten-step approach to conducting simulations is presented in this paper. To illustrate the approach, a clinical simulation study concerning implementation of Digital Clinical Practice Guidelines in a prototype planning and coordination module is presented. In the case study potential benefits were assessed in a full-scale simulation test including 18 health care professionals. The results showed that health care professionals can benefit from such a module. Unintended consequences concerning terminology and changes in the division of responsibility amongst healthcare professionals were also identified, and questions were raised concerning future workflow across sector borders. Furthermore unexpected new possible benefits concerning improved communication, content of information in discharge letters and quality management emerged during the testing. In addition new potential groups of users were identified. The case study is used to demonstrate the potential of using the clinical simulation approach described in the paper.

  2. Boundary conditions towards realistic simulation of jet engine noise

    NASA Astrophysics Data System (ADS)

    Dhamankar, Nitin S.

    Strict noise regulations at major airports and increasing environmental concerns have made prediction and attenuation of jet noise an active research topic. Large eddy simulation coupled with computational aeroacoustics has the potential to be a significant research tool for this problem. With the emergence of petascale computer clusters, it is now computationally feasible to include the nozzle geometry in jet noise simulations. In high Reynolds number experiments on jet noise, the turbulent boundary layer on the inner surface of the nozzle separates into a turbulent free shear layer. Inclusion of a nozzle with turbulent inlet conditions is necessary to simulate this phenomenon realistically. This will allow a reasonable comparison of numerically computed noise levels with the experimental results. Two viscous wall boundary conditions are implemented for modeling the nozzle walls. A characteristic-based approach is compared with a computationally cheaper, extrapolation-based formulation. In viscous flow over a circular cylinder under two different regimes, excellent agreement is observed between the results of the two approaches. The results agree reasonably well with reference experimental and numerical results. Both the boundary conditions are thus found to be appropriate, the extrapolation-based formulation having an edge with its low cost. This is followed with the crucial step of generation of a turbulent boundary layer inside the nozzle. A digital filter-based turbulent inflow condition, extended in a new way to non-uniform curvilinear grids is implemented to achieve this. A zero pressure gradient flat plate turbulent boundary layer is simulated at a high Reynolds number to show that the method is capable of producing sustained turbulence. The length of the adjustment region necessary for synthetic inlet turbulence to recover from modeling errors is estimated. A low Reynolds number jet simulation including a round nozzle geometry is performed and the method

  3. Expanding primary care opportunities: simulation for clinical reasoning.

    PubMed

    Phillippi, Julia C; Bull, Amy; Holley, Sharon L

    2013-05-01

    Many nurse practitioner specialties are requiring that basic primary care be included in their curricula. However, some experienced faculty within the specialty lack primary care experience. With a national shortage of nursing faculty, it is more important than ever to maximize available resources without overtaxing faculty workloads. Revision of our primary care practicum allowed nurse-midwifery faculty to lead a primary care clinical conference, using Family Nurse Practitioner (FNP) faculty as primary care experts. We revamped the clinical conference time to simulate clinical visits to guide the students through the clinical reasoning process. Low-fidelity simulation allowed students time to take a systematic approach to patient assessment, planning, and charting. The FNP "experts" were used to critique student chart notes prior to grading. This collaborative approach to the primary care clinical conference was well received by students, faculty, and preceptors and was quick and inexpensive to implement.

  4. Modeling and HIL Simulation of Flight Conditions Simulating Control System for the Altitude Test Facility

    NASA Astrophysics Data System (ADS)

    Zhou, Jun; Shen, Li; Zhang, Tianhong

    2016-12-01

    Simulated altitude test is an essential exploring, debugging, verification and validation means during the development of aero-engine. Free-jet engine test can simulate actual working conditions of aero-engine more realistically than direct-connect engine test but with relatively lower cost compared to propulsion wind tunnel test, thus becoming an important developing area of simulated altitude test technology. The Flight Conditions Simulating Control System (FCSCS) is of great importance to the Altitude Test Facility (ATF) but the development of that is a huge challenge. Aiming at improving the design efficiency and reducing risks during the development of FCSCS for ATFs, a Hardware- in-the-Loop (HIL) simulation system was designed and the mathematical models of key components such as the pressure stabilizing chamber, free-jet nozzle, control valve and aero-engine were built in this paper. Moreover, some HIL simulation experiments were carried out. The results show that the HIL simulation system designed and established in this paper is reasonable and effective, which can be used to adjust control parameters conveniently and assess the software and hardware in the control system immediately.

  5. Simulation Study of the Flow Boundary Condition for Rough Surfaces

    NASA Astrophysics Data System (ADS)

    He, Gang; Robbins, Mark O.

    2001-03-01

    In order to solve a flow problem with the continuum Navier-Stokes equation, a boundary condition must be assumed. In most cases, a no-slip condition is used, i.e. the velocity of the fluid is set equal to that of a bounding solid at their interface. Deviations from this condition can be quantified by a slip length S that represents the additional width of fluid that would be needed to accomodate any velocity difference at the interface. Previous simulations with atomically flat surfaces show that S can be very large in certain limits. (P. A. Thompson and M. O. Robbins, Phys. Rev. A, 41), 6830(1990). ( J.-L. Barrat and L. Bocquet, Phys. Rev. Lett., 82), 4671(1999). A dramatic divergence with S as shear rate increases has also been seen.( P. A. Thompson and S. M. Troian, Nature, 389), 360(1997) We have extended these simulations to surfaces with random roughness, steps, and angled facets typical of twin boundaries. In all cases, S decreases rapidly as the roughness increases. When peak-to-peak roughness is only two atomic diameters, values of S have dropped from more than 20 diameters to only one or two. In addition, the non-linear regime where S diverges with shear rate is supressed by surface roughness. These results suggest that the experimental behavior of atomically flat surfaces such as mica may be very different than that of more typical rough surfaces.

  6. Characterization of Apollo Bulk Soil Samples Under Simulated Lunar Conditions

    NASA Astrophysics Data System (ADS)

    Donaldson Hanna, K. L.; Pieters, C. M.; Thomas, I.; Bowles, N. E.; Greenhagen, B. T.

    2013-12-01

    Remote observations provide key insights into the composition and evolution of planetary surfaces. A fundamentally important component to any remote compositional analysis of planetary surfaces is laboratory measurements of well-characterized samples measured under the appropriate environmental conditions. The vacuum environment of airless bodies like the Moon creates a steep thermal gradient in the upper hundreds of microns of regolith. Lab studies of particulate rocks and minerals as well as selected lunar soils under vacuum and lunar-like conditions have identified significant effects of this thermal gradient on thermal infrared (TIR) spectral measurements [e.g. Logan et al. 1973, Salisbury and Walter 1989, Thomas et al. 2012, Donaldson Hanna et al. 2012]. Such lab studies demonstrate the high sensitivity of TIR emissivity spectra to environmental conditions under which they are measured. To best understand the effects of the near surface-environment of the Moon, a consortium of four institutions with the capabilities of characterizing lunar samples was created. The goal of the Thermal Infrared Emission Studies of Lunar Surface Compositions Consortium (TIRES-LSCC) is to characterize Apollo bulk soil samples with a range of compositions and maturities in simulated lunar conditions to provide better context for the spectral effects due to varying compositions and soil maturity as well as for the interpretation of data obtained by the LRO Diviner Lunar Radiometer and future lunar and airless body thermal emission spectrometers. An initial set of thermal infrared emissivity measurements of the bulk lunar soil samples will be made in three of the laboratories included in the TIRES-LSCC: the Asteroid and Lunar Environment Chamber (ALEC) in RELAB at Brown University, the Simulated Lunar Environment chamber in the Planetary Spectroscopy Facility (PSF) at the University of Oxford, and the Simulated Airless Body Emission Laboratory (SABEL) at the Jet Propulsion Laboratory

  7. Simulating the Phoenix Lander meteorological conditions with a Mars GCM

    NASA Astrophysics Data System (ADS)

    Daerden, F.; Neary, L.; Whiteway, J.; Dickinson, C.; Komguem, L.; McConnell, J. C.; Kaminski, J. W.

    2012-04-01

    An updated version of the GEM-Mars Global Circulation Model [1] is applied for the simulation of the meteorological conditions at the Phoenix lander site for the time period of the surface operations (Ls=76-150). The simulation results for pressure and temperature at the surface are compared to data from the Phoenix Meteorological Station (MET). The vertical profiles of dust and temperature are compared to Phoenix LIDAR measurements and data from orbit (CRISM and MCS on MRO). The simulated conditions in the PBL are compared to those obtained in a dedicated PBL-Aeolian dust model [2] which was successfully applied to drive a detailed microphysical model [3] for the interpretation of clouds and precipitation observed by the LIDAR on Phoenix [4,5]. [1] Moudden, Y. and J.C. McConnell (2005): A new model for multiscale modeling of the Martian atmosphere, GM3, J. Geophys. Res. 110, E04001, doi:10.1029/2004JE002354 [2] Davy, R., P. A. Taylor, W. Weng, and P.-Y. Li (2009), A model of dust in the Martian lower atmosphere, J. Geophys. Res., 114, D04108, doi:10.1029/2008JD010481. [3] Daerden, F., J.A. Whiteway, R. Davy, C. Verhoeven, L. Komguem, C. Dickinson, P. A. Taylor, and N. Larsen (2010), Simulating Observed Boundary Layer Clouds on Mars, Geophys. Res. Lett., 37, L04203, doi:10.1029/2009GL041523 [4] Whiteway, J., M. Daly, A. Carswell, T. Duck, C. Dickinson, L. Komguem, and C. Cook (2008), Lidar on the Phoenix mission to Mars, J. Geophys. Res., 113, E00A08, doi:10.1029/2007JE003002. [5] Whiteway, J., et al. (2009), Mars water ice clouds and precipitation, Science, 325, 68 - 70.

  8. Clinical simulators: applications and implications for rural medical education.

    PubMed

    Ypinazar, V A; Margolis, S A

    2006-01-01

    Medical education has undergone significant changes globally. Calls for the revitalisation of centuries old pathways of learning have resulted in innovative medical curricula. Didactic modes of teaching which involved the learning of copious amounts of facts have given way to curricula that focus on the horizontal and vertical integration of basic and clinical sciences. Increasing concern for patient care and safety has led to a 'gap' between the needs of medical students to acquire necessary psychomotor skills and the safety and wellbeing of the patient. This has resulted in alternate teaching methods that include non-patient based training for the acquisition of clinical skills. The use of computerised, full-sized human simulators provides medical students with the necessary psychomotor and clinical reasoning skills in a realistic learning environment, while remaining risk free to patients. These clinical simulators are powerful learning tools that have applications at all levels of medical education across multiple disciplines, emphasising the multidisciplinary approach required in many medical situations. This article reviews the literature on medical simulation and provides the contextual basis for the establishment of a Clinical Simulation Learning Centre (CSLC) in a rural clinical school in Australia. The educational program, as well as the design, layout and equipment of the CSLC are described, as well as implications for rural practitioners. The CSLC has been a major capital investment in a relatively under-resourced part of regional Australia and has provided opportunities for ongoing education across a range of healthcare professionals in the community.

  9. Clinical application of exome sequencing in undiagnosed genetic conditions

    PubMed Central

    Need, Anna C; Shashi, Vandana; Hitomi, Yuki; Schoch, Kelly; Shianna, Kevin V; McDonald, Marie T; Meisler, Miriam H

    2012-01-01

    Background There is considerable interest in the use of next-generation sequencing to help diagnose unidentified genetic conditions, but it is difficult to predict the success rate in a clinical setting that includes patients with a broad range of phenotypic presentations. Methods The authors present a pilot programme of whole-exome sequencing on 12 patients with unexplained and apparent genetic conditions, along with their unaffected parents. Unlike many previous studies, the authors did not seek patients with similar phenotypes, but rather enrolled any undiagnosed proband with an apparent genetic condition when predetermined criteria were met. Results This undertaking resulted in a likely genetic diagnosis in 6 of the 12 probands, including the identification of apparently causal mutations in four genes known to cause Mendelian disease (TCF4, EFTUD2, SCN2A and SMAD4) and one gene related to known Mendelian disease genes (NGLY1). Of particular interest is that at the time of this study, EFTUD2 was not yet known as a Mendelian disease gene but was nominated as a likely cause based on the observation of de novo mutations in two unrelated probands. In a seventh case with multiple disparate clinical features, the authors were able to identify homozygous mutations in EFEMP1 as a likely cause for macular degeneration (though likely not for other features). Conclusions This study provides evidence that next-generation sequencing can have high success rates in a clinical setting, but also highlights key challenges. It further suggests that the presentation of known Mendelian conditions may be considerably broader than currently recognised. PMID:22581936

  10. A Boundary Condition for Simulation of Flow Over Porous Surfaces

    NASA Technical Reports Server (NTRS)

    Frink, Neal T.; Bonhaus, Daryl L.; Vatsa, Veer N.; Bauer, Steven X. S.; Tinetti, Ana F.

    2001-01-01

    A new boundary condition is presented.for simulating the flow over passively porous surfaces. The model builds on the prior work of R.H. Bush to eliminate the need for constructing grid within an underlying plenum, thereby simplifying the numerical modeling of passively porous flow control systems and reducing computation cost. Code experts.for two structured-grid.flow solvers, TLNS3D and CFL3D. and one unstructured solver, USM3Dns, collaborated with an experimental porosity expert to develop the model and implement it into their respective codes. Results presented,for the three codes on a slender forebody with circumferential porosity and a wing with leading-edge porosity demonstrate a good agreement with experimental data and a remarkable ability to predict the aggregate aerodynamic effects of surface porosity with a simple boundary condition.

  11. Simulating realistic imaging conditions for in situ liquid microscopy

    SciTech Connect

    Welch, David A.; Faller, Roland; Evans, James E.; Browning, Nigel D.

    2013-12-01

    In situ transmission electron microscopy enables the imaging of biological cells, macromolecular protein complexes, nanoparticles, and other systems in a near-native environment. In order to improve interpretation of image contrast features and also predict ideal imaging conditions ahead of time, new virtual electron microscopic techniques are needed. A technique for virtual fluid-stage high-angle annular dark-field scanning transmission electron microscopy with the multislice method is presented that enables the virtual imaging of model fluid-stage systems composed of millions of atoms. The virtual technique is exemplified by simulating images of PbS nanoparticles under different imaging conditions and the results agree with previous experimental findings. General insight is obtained on the influence of the effects of fluid path length, membrane thickness, nanoparticle position, defocus and other microscope parameters on attainable image quality.

  12. Physiological and pathological clinical conditions and light scattering in brain

    NASA Astrophysics Data System (ADS)

    Kurata, Tsuyoshi; Iwata, Sachiko; Tsuda, Kennosuke; Kinoshita, Masahiro; Saikusa, Mamoru; Hara, Naoko; Oda, Motoki; Ohmae, Etsuko; Araki, Yuko; Sugioka, Takashi; Takashima, Sachio; Iwata, Osuke

    2016-08-01

    MRI of preterm infants at term commonly reveals subtle brain lesions such as diffuse white matter injury, which are linked with later cognitive impairments. The timing and mechanism of such injury remains unclear. The reduced scattering coefficient of near-infrared light (μs’) has been shown to correlate linearly with gestational age in neonates. To identify clinical variables associated with brain μs’, 60 preterm and full-term infants were studied within 7 days of birth. Dependence of μs’ obtained from the frontal head on clinical variables was assessed. In the univariate analysis, smaller μs’ was associated with antenatal glucocorticoid, emergency Caesarean section, requirement for mechanical ventilation, smaller gestational age, smaller body sizes, low 1- and 5-minute Apgar scores, higher cord blood pH and PO2, and higher blood HCO3‑ at the time of study. Multivariate analysis revealed that smaller gestational age, requirement for mechanical ventilation, and higher HCO3‑ at the time of study were correlated with smaller μs’. Brain μs’ depended on variables associated with physiological maturation and pathological conditions of the brain. Further longitudinal studies may help identify pathological events and clinical conditions responsible for subtle brain injury and subsequent cognitive impairments following preterm birth.

  13. Network condition simulator for benchmarking sewer deterioration models.

    PubMed

    Scheidegger, A; Hug, T; Rieckermann, J; Maurer, M

    2011-10-15

    An accurate description of aging and deterioration of urban drainage systems is necessary for optimal investment and rehabilitation planning. Due to a general lack of suitable datasets, network condition models are rarely validated, and if so with varying levels of success. We therefore propose a novel network condition simulator (NetCoS) that produces a synthetic population of sewer sections with a given condition-class distribution. NetCoS can be used to benchmark deterioration models and guide utilities in the selection of appropriate models and data management strategies. The underlying probabilistic model considers three main processes: a) deterioration, b) replacement policy, and c) expansions of the sewer network. The deterioration model features a semi-Markov chain that uses transition probabilities based on user-defined survival functions. The replacement policy is approximated with a condition-class dependent probability of replacing a sewer pipe. The model then simulates the course of the sewer sections from the installation of the first line to the present, adding new pipes based on the defined replacement and expansion program. We demonstrate the usefulness of NetCoS in two examples where we quantify the influence of incomplete data and inspection frequency on the parameter estimation of a cohort survival model and a Markov deterioration model. Our results show that typical available sewer inventory data with discarded historical data overestimate the average life expectancy by up to 200 years. Although NetCoS cannot prove the validity of a particular deterioration model, it is useful to reveal its possible limitations and shortcomings and quantifies the effects of missing or uncertain data. Future developments should include additional processes, for example to investigate the long-term effect of pipe rehabilitation measures, such as inliners.

  14. Overall thermal performance of flexible piping under simulated bending conditions

    NASA Astrophysics Data System (ADS)

    Fesmire, J. E.; Augustynowicz, S. D.; Demko, J. A.

    2002-05-01

    Flexible, vacuum-insulated transfer lines for low-temperature applications have higher thermal losses than comparable rigid lines. Typical flexible piping construction uses corrugated tubes, inner and outer, with a multilayer insulation (MLI) system in the annular space. Experiments on vacuum insulation systems in a flexible geometry were conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. The effects of bending were simulated by causing the inner tube to be eccentric with the outer tube. The effects of spacers were simulated in a controlled way by inserting spacer tubes for the length of the cylindrical test articles. Two material systems, standard MLI and a layered composite insulation (LCI), were tested under the full range of vacuum levels using a liquid nitrogen boiloff calorimeter to determine the apparent thermal conductivity (k-value). The results indicate that the flexible piping under simulated bending conditions significantly degrades the thermal performance of the insulation system. These data are compared to standard MLI for both straight and flexible piping configurations. The definition of an overall k-value for actual field installations (koafi) is described for use in design and analysis of cryogenic piping systems.

  15. Overall Thermal Performance of Flexible Piping Under Simulated Bending Conditions

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.; Augustynowicz, S. D.; Demko, J. A.; Thompson, Karen (Technical Monitor)

    2001-01-01

    Flexible, vacuum-insulated transfer lines for low-temperature applications have higher thermal losses than comparable rigid lines. Typical flexible piping construction uses corrugated tubes, inner and outer, with a multilayer insulation (MLI) system in the annular space. Experiments on vacuum insulation systems in a flexible geometry were conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. The effects of bending were simulated by causing the inner tube to be eccentric with the outer tube. The effects of spacers were simulated in a controlled way by inserting spacer tubes for the length of the cylindrical test articles. Two material systems, standard MLI and a layered composite insulation (LCI), were tested under the full range of vacuum levels using a liquid nitrogen boiloff calorimeter to determine the apparent thermal conductivity (k-value). The results indicate that the flexible piping under simulated bending conditions significantly degrades the thermal performance of the insulation system. These data are compared to standard MLI for both straight and flexible piping configurations. The definition of an overall k-value for actual field installations (k(sub oafi)) is described for use in design and analysis of cryogenic piping systems.

  16. Leaching of metals from cement under simulated environmental conditions.

    PubMed

    Lu, Huixia; Wei, Fang; Tang, Jingchun; Giesy, John P

    2016-03-15

    Leaching of metals from cement under various environmental conditions was measured to evaluate their environmental safety. A cement product containing clinker, which was produced from cement kiln co-processing of hazardous wastes, was solidified and leaching of metals was characterized using the 8-period test. Concentrations and speciation of metals in cements were determined. Effects of ambient environment and particle size on leachability of metals and mineralogical phases of cement mortars were evaluated by use of XRD and SEM. Results indicated that metals in cements were leachable in various media in descending order of: sea water, groundwater and acid rain. Cr, Ni, As, Co and V were leached by simulated sea water, while Cu, Cd, Pb, Zn, Mn, Sb and Tl were not leached in simulated sea water, groundwater or acid rain. When exposed to simulated acid rain or groundwater, amounts of Cr, Ni, As and V leached was inversely proportional to particle size of cement mortar. According to the one-dimensional diffusion equation, Cr was most leachable and the cumulative leached mass was predicted to be 9.6 mg kg(-1) after 20 years. Results of this study are useful in predicting releases of metals from cement products containing ash and clinkers cement kiln co-processing of hazardous wastes, so that they can be safely applied in the environment.

  17. A brief simulation intervention increasing basic science and clinical knowledge

    PubMed Central

    Sheakley, Maria L.; Gilbert, Gregory E.; Leighton, Kim; Hall, Maureen; Callender, Diana; Pederson, David

    2016-01-01

    Background The United States Medical Licensing Examination (USMLE) is increasing clinical content on the Step 1 exam; thus, inclusion of clinical applications within the basic science curriculum is crucial. Including simulation activities during basic science years bridges the knowledge gap between basic science content and clinical application. Purpose To evaluate the effects of a one-off, 1-hour cardiovascular simulation intervention on a summative assessment after adjusting for relevant demographic and academic predictors. Methods This study was a non-randomized study using historical controls to evaluate curricular change. The control group received lecture (nl=515) and the intervention group received lecture plus a simulation exercise (nl+s=1,066). Assessment included summative exam questions (n=4) that were scored as pass/fail (≥75%). USMLE-style assessment questions were identical for both cohorts. Descriptive statistics for variables are presented and odds of passage calculated using logistic regression. Results Undergraduate grade point ratio, MCAT-BS, MCAT-PS, age, attendance at an academic review program, and gender were significant predictors of summative exam passage. Students receiving the intervention were significantly more likely to pass the summative exam than students receiving lecture only (P=0.0003). Discussion Simulation plus lecture increases short-term understanding as tested by a written exam. A longitudinal study is needed to assess the effect of a brief simulation intervention on long-term retention of clinical concepts in a basic science curriculum. PMID:27060102

  18. Cardioprotection by remote ischemic conditioning: Mechanisms and clinical evidences

    PubMed Central

    Aimo, Alberto; Borrelli, Chiara; Giannoni, Alberto; Pastormerlo, Luigi Emilio; Barison, Andrea; Mirizzi, Gianluca; Emdin, Michele; Passino, Claudio

    2015-01-01

    In remote ischemic conditioning (RIC), several cycles of ischemia and reperfusion render distant organ and tissues more resistant to the ischemia-reperfusion injury. The intermittent ischemia can be applied before the ischemic insult in the target site (remote ischemic preconditioning), during the ischemic insult (remote ischemic perconditioning) or at the onset of reperfusion (remote ischemic postconditioning). The mechanisms of RIC have not been completely defined yet; however, these mechanisms must be represented by the release of humoral mediators and/or the activation of a neural reflex. RIC has been discovered in the heart, and has been arising great enthusiasm in the cardiovascular field. Its efficacy has been evaluated in many clinical trials, which provided controversial results. Our incomplete comprehension of the mechanisms underlying the RIC could be impairing the design of clinical trials and the interpretation of their results. In the present review we summarize current knowledge about RIC pathophysiology and the data about its cardioprotective efficacy. PMID:26516416

  19. Enhancing pediatric clinical competency with high-fidelity simulation.

    PubMed

    Birkhoff, Susan D; Donner, Carol

    2010-09-01

    In today's tertiary pediatric hospital setting, the increased complexity of patient care demands seamless coordination and collaboration among multidisciplinary team members. In an effort to enhance patient safety, clinical competence, and teamwork, simulation-based learning has become increasingly integrated into pediatric clinical practice as an innovative educational strategy. The simulated setting provides a risk-free environment where learners can incorporate cognitive, psychomotor, and affective skill acquisition without fear of harming patients. One pediatric university hospital in Southeastern Pennsylvania has enhanced the traditional American Heart Association (AHA) Pediatric Advanced Life Support (PALS) course by integrating high-fidelity simulation into skill acquisition, while still functioning within the guidelines and framework of the AHA educational standards. However, very little research with reliable standardized testing methods has been done to measure the effect of simulation-based learning. This article discusses the AHA guidelines for PALS, evaluation of PALS and nursing clinical competencies, communication among a multidisciplinary team, advantages and disadvantages of simulation, incorporation of high-fidelity simulation into pediatric practice, and suggestions for future practice.

  20. Noise simulation system for determining imaging conditions in digital radiography

    NASA Astrophysics Data System (ADS)

    Tanaka, R.; Ichikawa, K.; Matsubara, K.; Kawashima, H.

    2012-03-01

    Reduction of exposure dose and improvement in image quality can be expected to result from advances in the performance of imaging detectors. We propose a computerized method for determining optimized imaging conditions by use of simulated images. This study was performed to develop a prototype system for image noise and to ensure consistency between the resulting images and actual images. An RQA5 X-ray spectrum was used for determination of input-output characteristics of a flat-panel detector (FPD). The number of incident quantum to the detector per pixel (counts/pixel) was calculated according to the pixel size of the detector and the quantum number in RQA5 determined in IEC6220-1. The relationship among tube current-time product (mAs), exposure dose (C/kg) at the detector surface, the number of incident quanta (counts/pixel), and pixel values measured on the images was addressed, and a conversion function was then created. The images obtained by the FPD was converted into a map of incident quantum numbers and input into random-value generator to simulate image noise. In addition, graphic user interface was developed to observe images with changing image noise and exposure dose levels, which have trade-off relationship. Simulation images provided at different noise levels were compared with actual images obtained by the FPD system. The results indicated that image noise was simulated properly both in objective and subjective evaluation. The present system could allow us to determine necessary dose from image quality and also to estimate image quality from any exposure dose.

  1. Influence of Spanwise Boundary Conditions on Slat Noise Simulations

    NASA Technical Reports Server (NTRS)

    Lockard, David P.; Choudhari, Meelan M.; Buning, Pieter G.

    2015-01-01

    The slat noise from the 30P/30N high-lift system is being investigated through computational fluid dynamics simulations with the OVERFLOW code in conjunction with a Ffowcs Williams-Hawkings acoustics solver. In the present study, two different spanwise grids are being used to investigate the effect of the spanwise extent and periodicity on the near-field unsteady structures and radiated noise. The baseline grid with periodic boundary conditions has a short span equal to 1/9th of the stowed chord, whereas the other, longer span grid adds stretched grids on both sides of the core, baseline grid to allow inviscid surface boundary conditions at both ends. The results indicate that the near-field mean statistics obtained using the two grids are similar to each other, as are the directivity and spectral shapes of the radiated noise. However, periodicity forces all acoustic waves with less than one wavelength across the span to be two-dimensional, without any variation in the span. The spanwise coherence of the acoustic waves is what is needed to make estimates of the noise that would be radiated from realistic span lengths. Simulations with periodic conditions need spans of at least six slat chords to allow spanwise variation in the low-frequencies associated with the peak of broadband slat noise. Even then, the full influence of the periodicity is unclear, so employing grids with a fine, central region and highly stretched meshes that go to slip walls may be a more efficient means of capturing the spanwise decorrelation of low-frequency acoustic phenomena.

  2. Glaucoma and Driving Risk under Simulated Fog Conditions

    PubMed Central

    Diniz-Filho, Alberto; Boer, Erwin R.; Elhosseiny, Ahmed; Wu, Zhichao; Nakanishi, Masaki; Medeiros, Felipe A.

    2016-01-01

    Purpose We evaluate driving risk under simulated fog conditions in glaucoma and healthy subjects. Methods This cross-sectional study included 41 glaucoma patients and 25 age-matched healthy subjects who underwent driving simulation. Tests consisted of curve negotiation without and with fog preview at 30 m of distance and two controlled speeds (slow and fast). Inverse time-to-line crossing (invTLC) was used as metric to quantify risk; higher invTLC values indicating higher risk, as less time is available to avoid drifting out of the road. Piecewise regression models were used to investigate the relationship between differences in invTLC in fog and nonfog conditions and visual field loss. Results Glaucoma patients had greater increase in driving risk under fog compared to controls, as indicated by invTLC differences (0.490 ± 0.578 s−1 and 0.208 ± 0.106 s−1, respectively; P = 0.002). Mean deviation (MD) of the better eye was significantly associated with driving risk under fog, with a breakpoint of −9 dB identified by piecewise regression. For values below the breakpoint, each 1 dB lower MD of better eye was associated with 0.117 s−1 higher invTLC under fast speed (adjusted R2 = 57.9%; P < 0.001). Conclusions Glaucoma patients have a steeper increase in driving risk under fog conditions when compared to healthy subjects, especially when the severity of visual field damage falls below −9 dB of MD in the better eye. Translational Relevance By investigating the relationship between driving risk and disease severity breakpoint, this study may provide guidance to clinicians in recognizing glaucoma patients who may be unfit to drive in complex situations such as fog. PMID:27980878

  3. Unannounced in situ simulations: integrating training and clinical practice.

    PubMed

    Walker, Susanna T; Sevdalis, Nick; McKay, Anthony; Lambden, Simon; Gautama, Sanjay; Aggarwal, Rajesh; Vincent, Charles

    2013-06-01

    Simulation-based training for healthcare providers is well established as a viable, efficacious training tool, particularly for the training of non-technical team-working skills. These skills are known to be critical to effective teamwork, and important in the prevention of error and adverse events in hospitals. However, simulation suites are costly to develop and releasing staff to attend training is often difficult. These factors may restrict access to simulation training. We discuss our experiences of 'in situ' simulation for unannounced cardiac arrest training when the training is taken to the clinical environment. This has the benefit of decreasing required resources, increasing realism and affordability, and widening multidisciplinary team participation, thus enabling assessment and training of non-technical team-working skills in real clinical teams. While there are practical considerations of delivering training in the clinical environment, we feel there are many potential benefits compared with other forms of simulation training. We are able to tailor the training to the needs of the location, enabling staff to see a scenario that is relevant to their practice. This is particularly useful for staff who have less exposure to cardiac arrest events, such as radiology staff. We also describe the important benefit of risk assessment for a clinical environment. During our simulations we have identified a number of issues that, had they occurred during a real resuscitation attempt, may have led to patient harm or patient death. For these reasons we feel in situ simulation should be considered by every hospital as part of a patient safety initiative.

  4. Aqueous alteration of VHTR fuels particles under simulated geological conditions

    NASA Astrophysics Data System (ADS)

    Ait Chaou, Abdelouahed; Abdelouas, Abdesselam; Karakurt, Gökhan; Grambow, Bernd

    2014-05-01

    Very High Temperature Reactor (VHTR) fuels consist of the bistructural-isotropic (BISO) or tristructural-isotropic (TRISO)-coated particles embedded in a graphite matrix. Management of the spent fuel generated during VHTR operation would most likely be through deep geological disposal. In this framework we investigated the alteration of BISO (with pyrolytic carbon) and TRISO (with SiC) particles under geological conditions simulated by temperatures of 50 and 90 °C and in the presence of synthetic groundwater. Solid state (scanning electron microscopy (SEM), micro-Raman spectroscopy, electron probe microanalyses (EPMA) and X-ray photoelectron spectroscopy (XPS)) and solution analyses (ICP-MS, ionique chromatography (IC)) showed oxidation of both pyrolytic carbon and SiC at 90 °C. Under air this led to the formation of SiO2 and a clay-like Mg-silicate, while under reducing conditions (H2/N2 atmosphere) SiC and pyrolytic carbon were highly stable after a few months of alteration. At 50 °C, in the presence and absence of air, the alteration of the coatings was minor. In conclusion, due to their high stability in reducing conditions, HTR fuel disposal in reducing deep geological environments may constitute a viable solution for their long-term management.

  5. Osteoblasts subjected to spaceflight and simulated space shuttle launch conditions.

    PubMed

    Kacena, Melissa A; Todd, Paul; Landis, William J

    2003-01-01

    To understand further the effects of spaceflight on osteoblast-enriched cultures, normal chicken calvarial osteoblasts were flown aboard shuttle flight STS-77, and the total number of attached cells was determined. Spaceflight and control cultures were chemically fixed 3 h and 3 d after launch. These fixed cultures were processed for scanning electron microscopy (SEM). The SEM analysis showed that with just 3 d of exposure to spaceflight, coverslip cultures contained 300 +/- 100 cells/mm2, whereas 1G control samples contained a confluent monolayer of cells (2400 +/- 200 cells/mm2). Although the cultures flown in space experienced a drastic decline in cell number in just 3 d, without further experimentation it was impossible to determine whether the decline was a result of microgravity, the harsh launch environment, or some combination of these factors. Therefore, this research attempted to address the effect of launch by subjecting osteoblasts to conditions simulating shuttle launch accelerations, noise, and vibrations. No differences, compared with controls, were seen in the number of total or viable cells after exposure to these various launch conditions. Taken together, these data indicate that the magnitude of gravitational loading (3G maximum) and vibration (7.83G rms maximum) resulting from launch does not adversely affect osteoblasts in terms of total or viable cell number immediately, but launch conditions, or the microgravity environment itself, may start a cascade of events that over several d contributes to cell loss.

  6. Joint conditional simulations and the spectral approach for flow modeling

    NASA Astrophysics Data System (ADS)

    Gutjahr, A.; Bullard, B.; Hatch, S.; Hughson, L.

    1994-03-01

    The use of data to condition single random fields has a well-established history. However, the joint use of data from several cross-correlated random fields is not as well developed. For example, the use of both transmissivity and head data in a steady state 2-d stochastic flow problem is essentially an inverse problem that is very important for both flow and transport predictions. This problem is addressed here by using a combination of numerical simulation and analytical methods and its application illustrated. The type of information conveyed by the different data categories is explored. The results presented are especially interesting in that head and transmissivity each give different information: Head values would appear to constrain the geometry of the paths while transmissivity data yields information about travel times. The linearized model is expanded to an iterative procedure and the “true” conditional distribution at several locations is compared with the iterative solution. The problem mentioned above is one with a special transfer function specified by the flow equation. In the second part of the paper a Fast Fourier Transform method for generation and conditioning of two or more random fields is introduced. This procedure is simple to implement, fast and very flexible.

  7. The Dialysis Exercise: A Clinical Simulation for Preclinical Medical Students.

    ERIC Educational Resources Information Center

    And Others; Bernstein, Richard A.

    1980-01-01

    A clinical decision-making simulation that helps students understand the relationship between psychosocial factors and medical problem-solving is described. A group of medical students and one faculty member comprise a selection committee to agree on the order in which four patients will be selected for renal dialysis. (MLW)

  8. Numerical simulations of clinical focused ultrasound functional neurosurgery

    PubMed Central

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-01-01

    A computational model utilizing grid and finite difference methods was developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13 % lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13 % smaller in the anterior–posterior direction and 22 ± 14% smaller in the inferior–superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  9. Numerical simulations of clinical focused ultrasound functional neurosurgery

    NASA Astrophysics Data System (ADS)

    Pulkkinen, Aki; Werner, Beat; Martin, Ernst; Hynynen, Kullervo

    2014-04-01

    A computational model utilizing grid and finite difference methods were developed to simulate focused ultrasound functional neurosurgery interventions. The model couples the propagation of ultrasound in fluids (soft tissues) and solids (skull) with acoustic and visco-elastic wave equations. The computational model was applied to simulate clinical focused ultrasound functional neurosurgery treatments performed in patients suffering from therapy resistant chronic neuropathic pain. Datasets of five patients were used to derive the treatment geometry. Eight sonications performed in the treatments were then simulated with the developed model. Computations were performed by driving the simulated phased array ultrasound transducer with the acoustic parameters used in the treatments. Resulting focal temperatures and size of the thermal foci were compared quantitatively, in addition to qualitative inspection of the simulated pressure and temperature fields. This study found that the computational model and the simulation parameters predicted an average of 24 ± 13% lower focal temperature elevations than observed in the treatments. The size of the simulated thermal focus was found to be 40 ± 13% smaller in the anterior-posterior direction and 22 ± 14% smaller in the inferior-superior direction than in the treatments. The location of the simulated thermal focus was off from the prescribed target by 0.3 ± 0.1 mm, while the peak focal temperature elevation observed in the measurements was off by 1.6 ± 0.6 mm. Although the results of the simulations suggest that there could be some inaccuracies in either the tissue parameters used, or in the simulation methods, the simulations were able to predict the focal spot locations and temperature elevations adequately for initial treatment planning performed to assess, for example, the feasibility of sonication. The accuracy of the simulations could be improved if more precise ultrasound tissue properties (especially of the

  10. Simulating flight boundary conditions for orbiter payload modal survey

    NASA Technical Reports Server (NTRS)

    Chung, Y. T.; Sernaker, M. L.; Peebles, J. H.

    1993-01-01

    An approach to simulate the characteristics of the payload/orbiter interfaces for the payload modal survey was developed. The flexure designed for this approach is required to provide adequate stiffness separation in the free and constrained interface degrees of freedom to closely resemble the flight boundary condition. Payloads will behave linearly and demonstrate similar modal effective mass distribution and load path as the flight if the flexure fixture is used for the payload modal survey. The potential non-linearities caused by the trunnion slippage during the conventional fixed base modal survey may be eliminated. Consequently, the effort to correlate the test and analysis models can be significantly reduced. An example is given to illustrate the selection and the sensitivity of the flexure stiffness. The advantages of using flexure fixtures for the modal survey and for the analytical model verification are also demonstrated.

  11. Filter Media Tests Under Simulated Martian Atmospheric Conditions

    NASA Technical Reports Server (NTRS)

    Agui, Juan H.

    2016-01-01

    Human exploration of Mars will require the optimal utilization of planetary resources. One of its abundant resources is the Martian atmosphere that can be harvested through filtration and chemical processes that purify and separate it into its gaseous and elemental constituents. Effective filtration needs to be part of the suite of resource utilization technologies. A unique testing platform is being used which provides the relevant operational and instrumental capabilities to test articles under the proper simulated Martian conditions. A series of tests were conducted to assess the performance of filter media. Light sheet imaging of the particle flow provided a means of detecting and quantifying particle concentrations to determine capturing efficiencies. The media's efficiency was also evaluated by gravimetric means through a by-layer filter media configuration. These tests will help to establish techniques and methods for measuring capturing efficiency and arrestance of conventional fibrous filter media. This paper will describe initial test results on different filter media.

  12. Properties of Cerro Prieto rock at simulated in situ conditions

    SciTech Connect

    Schatz, J.F.

    1981-01-01

    Rocks from the Cerro Prieto Geothermal Field were tested under simulated in situ conditions in the laboratory to determine their properties and response to pore pressure reduction as would be caused by reservoir production. The primary purpose of the project was to provide information on compaction and creep as they may contribute to surface subsidence. Results show typical compressibilities for reservoir rocks of about 1 x 10/sup -6/ psi/sup -1/ and creep compaction rates of about 1 x 10/sup -9/ sec/sup -1/ when triggered by 1000 psi pore pressure reduction. This creep rate would cause significant porosity reduction if it continued for several years. Therefore it becomes important to learn how to correctly extrapolate such data to long times.

  13. Effects of Perchlorate on Organic Molecules under Simulated Mars Conditions

    NASA Astrophysics Data System (ADS)

    Carrier, B. L.; Kounaves, S. P.

    2014-12-01

    Perchlorate (ClO4-) was discovered in the northern polar region of Mars by the Mars Phoenix Lander in 2008 and has also been recently detected by the Curiosity Rover in Gale Crater [1,2]. Perchlorate has also been shown to be formed under current Mars conditions via the oxidation of mineral chlorides, further supporting the theory that perchlorate is present globally on Mars [3]. The discovery of perchlorate on Mars has raised important questions about the effects of perchlorate on the survival and detection of organic molecules. Although it has been shown that pyrolysis in the presence of perchlorate results in the alteration or destruction of organic molecules [4], few studies have been conducted on the potential effects of perchlorate on organic molecules under martian surface conditions. Although perchlorate is typically inert under Mars-typical temperatures [5], perchlorate does absorb high energy UV radiation, and has been shown to decompose to form reactive oxychlorine species such as chlorite (ClO2-) when exposed to martian conditions including UV or ionizing radiation [6,7]. Here we investigate the effects of perchlorate on the organic molecules tryptophan, benzoic acid and mellitic acid in order to determine how perchlorate may alter these compounds under Mars conditions. Experiments are performed in a Mars Simulation Chamber (MSC) capable of reproducing the temperature, pressure, atmospheric composition and UV flux found on Mars. Soil simulants are prepared consisting of SiO2 and each organic, as well as varying concentrations of perchlorate salts, and exposed in the MSC. Subsequent to exposure in the MSC samples are leached and the leachate analyzed by HPLC and LC-MS to determine the degree of degradation of the original organic and the identity of any potential decomposition products formed by oxidation or chlorination. References: [1] Kounaves et al., J. Geophys. Res. Planets, Vol. 115, p. E00E10, 2010 [2] Glavin et al., J. Geophys. Res. Planets, Vol

  14. Patch-based iterative conditional geostatistical simulation using graph cuts

    NASA Astrophysics Data System (ADS)

    Li, Xue; Mariethoz, Gregoire; Lu, DeTang; Linde, Niklas

    2016-08-01

    Training image-based geostatistical methods are increasingly popular in groundwater hydrology even if existing algorithms present limitations that often make real-world applications difficult. These limitations include a computational cost that can be prohibitive for high-resolution 3-D applications, the presence of visual artifacts in the model realizations, and a low variability between model realizations due to the limited pool of patterns available in a finite-size training image. In this paper, we address these issues by proposing an iterative patch-based algorithm which adapts a graph cuts methodology that is widely used in computer graphics. Our adapted graph cuts method optimally cuts patches of pixel values borrowed from the training image and assembles them successively, each time accounting for the information of previously stitched patches. The initial simulation result might display artifacts, which are identified as regions of high cost. These artifacts are reduced by iteratively placing new patches in high-cost regions. In contrast to most patch-based algorithms, the proposed scheme can also efficiently address point conditioning. An advantage of the method is that the cut process results in the creation of new patterns that are not present in the training image, thereby increasing pattern variability. To quantify this effect, a new measure of variability is developed, the merging index, quantifies the pattern variability in the realizations with respect to the training image. A series of sensitivity analyses demonstrates the stability of the proposed graph cuts approach, which produces satisfying simulations for a wide range of parameters values. Applications to 2-D and 3-D cases are compared to state-of-the-art multiple-point methods. The results show that the proposed approach obtains significant speedups and increases variability between realizations. Connectivity functions applied to 2-D models transport simulations in 3-D models are used to

  15. Multi-Scale Initial Conditions For Cosmological Simulations

    SciTech Connect

    Hahn, Oliver; Abel, Tom; /KIPAC, Menlo Park /ZAH, Heidelberg /HITS, Heidelberg

    2011-11-04

    We discuss a new algorithm to generate multi-scale initial conditions with multiple levels of refinements for cosmological 'zoom-in' simulations. The method uses an adaptive convolution of Gaussian white noise with a real-space transfer function kernel together with an adaptive multi-grid Poisson solver to generate displacements and velocities following first- (1LPT) or second-order Lagrangian perturbation theory (2LPT). The new algorithm achieves rms relative errors of the order of 10{sup -4} for displacements and velocities in the refinement region and thus improves in terms of errors by about two orders of magnitude over previous approaches. In addition, errors are localized at coarse-fine boundaries and do not suffer from Fourier-space-induced interference ringing. An optional hybrid multi-grid and Fast Fourier Transform (FFT) based scheme is introduced which has identical Fourier-space behaviour as traditional approaches. Using a suite of re-simulations of a galaxy cluster halo our real-space-based approach is found to reproduce correlation functions, density profiles, key halo properties and subhalo abundances with per cent level accuracy. Finally, we generalize our approach for two-component baryon and dark-matter simulations and demonstrate that the power spectrum evolution is in excellent agreement with linear perturbation theory. For initial baryon density fields, it is suggested to use the local Lagrangian approximation in order to generate a density field for mesh-based codes that is consistent with the Lagrangian perturbation theory instead of the current practice of using the Eulerian linearly scaled densities.

  16. Reactivity landscape of pyruvate under simulated hydrothermal vent conditions

    PubMed Central

    Novikov, Yehor; Copley, Shelley D.

    2013-01-01

    Pyruvate is an important “hub” metabolite that is a precursor for amino acids, sugars, cofactors, and lipids in extant metabolic networks. Pyruvate has been produced under simulated hydrothermal vent conditions from alkyl thiols and carbon monoxide in the presence of transition metal sulfides at 250 °C [Cody GD et al. (2000) Science 289(5483):1337–1340], so it is plausible that pyruvate was formed in hydrothermal systems on the early earth. We report here that pyruvate reacts readily in the presence of transition metal sulfide minerals under simulated hydrothermal vent fluids at more moderate temperatures (25–110 °C) that are more conducive to survival of biogenic molecules. We found that pyruvate partitions among five reaction pathways at rates that depend upon the nature of the mineral present; the concentrations of H2S, H2, and NH4Cl; and the temperature. In most cases, high yields of one or two primary products are found due to preferential acceleration of certain pathways. Reactions observed include reduction of ketones to alcohols and aldol condensation, both reactions that are common in extant metabolic networks. We also observed reductive amination to form alanine and reduction to form propionic acid. Amino acids and fatty acids formed by analogous processes may have been important components of a protometabolic network that allowed the emergence of life. PMID:23872841

  17. Distributed simulations of landslides for different rainfall conditions

    NASA Astrophysics Data System (ADS)

    Dhakal, Amod S.; Sidle, Roy C.

    2004-03-01

    A physically based distributed slope stability model is described that utilizes a combined surface-subsurface kinematic wave module to assess groundwater fluctuations related to slope stability. A total of 82 major rainstorms from 1972 to 1990 in Carnation Creek, British Columbia, were examined to determine the influence of different characteristics of rainstorms (such as mean and maximum hourly intensity, duration, and rainfall amount) on the slope stability. These rainstorms vary in mean intensity from 1.6 to 11.2 mm h-1, storm duration from 11 to 93 h, and maximum hourly intensity from 3.4 to 35 mm h-1. Four synthetic uniform intensity rainstorms were also tested against real storms to assess the effect of short-term hourly rainfall intensity peaks on landslide occurrence. Altogether, 602 simulations were conducted. The combined influence of mean and maximum hourly intensity, duration, and total rainfall amount of rainstorms were important in generating landslides. The temporal distribution of short-term intensity also influenced the landslide occurrence. When saturated hydraulic conductivity of the soil was lowered or soil depth was raised, most rainstorms produced larger numbers of landslides. For the most part, actual rainstorms produced less stable conditions than their synthetic uniform intensity counterparts. For all landslide-producing storms, slope failure usually occurred after some threshold of cumulative rainfall and maximum hourly rainfall intensity. These simulations provide insights into the distributed behaviour of landslide occurrence during large rainstorms with varying characteristics.

  18. Computer simulation of equilibrium conditions following a plant 'trip'

    NASA Astrophysics Data System (ADS)

    Limb, D.

    When a process or part of a process experiences an emergency 'trip', the contained fluids redistribute themselves based upon the prevailing pressure gradients and depending upon the positions of valves at the time of the trip. Reverse flow through rotating compression machinery may occur, depending upon the locations of non-return valves. Reduction in pressure and mixing of cryogenic fluids of different compositions and/or temperatures can both lead to generation of significant volumes of vapour. This equilibration process is usually largely over in a matter of seconds rather than minutes. Key questions facing process and mechanical designers are: what is the settle-out pressure, and can we ensure relief valves do not lift following a trip? To answer these related questions it is necessary to analyse the state of the system prior to the trip, and then, based upon valve positions, etc., construct a model of the worst case probable scenarios for the qualitative redistribution of fluid inventory. At this point the simulation program may be employed to help calculate rigorously the final settle out conditions for each of the possible scenarios. This technique is particularly appropriate for cryogenic processes including refrigeration cycles. It is illustrated here with the help of a multistage hydrocarbon compressor example. Other related non-standard applications of the steady state process simulation program are identified.

  19. Construction of protocellular structures under simulated primitive earth conditions.

    PubMed

    Yanagawa, H; Ogawa, Y; Kojima, K; Ito, M

    1988-01-01

    We have developed experimental approaches for the construction of protocellular structures under simulated primitive earth conditions and studied their formation and characteristics. Three types of envelopes; protein envelopes, lipid envelopes, and lipid-protein envelopes are considered as candidates for protocellular structures. Simple protein envelopes and lipid envelopes are presumed to have originated at an early stage of chemical evolution, interaction mutually and then evolved into more complex envelopes composed of both lipids and proteins. Three kinds of protein envelopes were constructed in situ from amino acids under simulated primitive earth conditions such as a fresh water tide pool, a warm sea, and a submarine hydrothermal vent. One protein envelope was formed from a mixture of amino acid amides at 80 degrees C using multiple hydration-dehydration cycles. Marigranules, protein envelope structures, were produced from mixtures of glycine and acidic, basic and aromatic amino acids at 105 degrees C in a modified sea medium enriched with essential transition elements. Thermostable microspheres were also formed from a mixture of glycine, alanine, valine, and aspartic acid at 250 degrees C and above. The microspheres did not form at lower temperatures and consist of silicates and peptide-like polymers containing imide bonds and amino acid residues enriched in valine. Amphiphilic proteins with molecular weights of 2000 were necessary for the formation of the protein envelopes. Stable lipid envelopes were formed from different dialkyl phospholipids and fatty acids. Large, stable, lipid-protein envelopes were formed from egg lecithin and the solubilized marigranules. Polycations such as polylysine and polyhistidine, or basic proteins such as lysozyme and cytochrome c also stabilized lipid-protein envelopes.

  20. Selected CERES electronic component survivability under simulated overvoltage conditions

    NASA Astrophysics Data System (ADS)

    Chapman, John J.; Grant, Michael S.; Bockman, James; Clark, Vernon M.; Hess, Phillip C.

    1999-09-01

    In August, 1998, a Clouds and the Earth's Radiant Energy System (CERES) instrument telemetry housekeeping parameter generated a yellow warning message that indicated an on- board +15V Data Acquisition Assembly (DAA) power converter deregulation anomaly. An exhaustive investigation was undertaken to understand this anomaly and the long-term consequnces which have severely reduced CERES operations on the Tropical Rainfall Measuring Mission (TRMM) spacecraft. Among investigations performed were groudn tests that approximated the on-board electronic circuitry using a small quantity of flight identical components exposed to maximum spacecraft bus over-voltage conditions. These components include monolithic integrated microcircuits that perform analog signal conditions on instrument sensor signals and an analog-to-digital converter (ADC) for the entire DAA. All microcircuit packages have either a bipolar silicon design with internal current limiting protections or have a complementary metal oxide semiconductor (CMOS) design with bias protections. Ground test that have been running for approximately 8 months have indicated that these components are capable of withstanding as much as twice their input supply voltage ratings without noticeable performance degradation. This data provided CERES operators with assured confidence to be able to continue instrument science operations over the remaining life of the TRMM. This paper will discuss this anomaly and some possible cause, a simulator of affected electronics, test results, prognosis for future CERES operations, and conclusions.

  1. PC CLIN-SIM: a toolbook based clinical simulation environment.

    PubMed Central

    Pincetl, P.; Cobbs, E.; Hubshman, J.; Liao, R. L.; Baranano, S.; Heller, R.; Fry, E.; Piemme, T.

    1992-01-01

    The Departments of Computer Medicine, Health Care Sciences, Medicine, and Electrical Engineering & Computer Science at the George Washington University have joined forces to create a clinical simulation program. The purpose of this program is to provide experience in the management of complex patient populations (eg geriatrics). A number of simulation programs are available commercially, however none provide adequate geriatric content, or were deemed to lack functionality important to the developers. The immediate goal of this effort was to create a computer-based, core curriculum in geriatric medicine for medical and allied health students. The curriculum includes case simulations linked to a comprehensive reference database. The development objectives were to create an intuitive, friendly, consistent user interface which could serve as a shell for additional content areas. In order to increase fidelity, free text entry and time simulation were included. PMID:1482984

  2. Laboratory evaluation of 10 heat and moisture exchangers using simulated aeromedical evacuation conditions.

    PubMed

    Suliman, Huda S; Fecura, Stephen E; Baskin, Jonathan; Kalns, John E

    2011-06-01

    Heat and moisture exchangers (HMEs) are used for airway humidification in mechanically ventilated patients and have been evaluated only under hospital conditions. U.S. Air Force aeromedical evacuation transports are performed under rugged conditions further complicated by the cold and dry environment in military aircrafts, and HMEs are used to provide airway humidification for patients. This study evaluated 10 commercial HMEs using a test system that simulated aeromedical evacuation conditions. Although the American National Standards Institute recommends inspired air to be at an absolute humidity value of > or = 30 mg/L for mechanically ventilated patients, the highest absolute humidity by any HME was approximately 20 mg/L. Although none of the HMEs were able to maintain a temperature high enough to achieve the humidity standard of the American National Standards Institute, the clinical significance of this standard may be less important than the relative humidity maintained in the respired air, especially on evacuation flights of short duration.

  3. Experiments and numerical simulation of mixing under supercritical conditions

    NASA Astrophysics Data System (ADS)

    Schmitt, T.; Rodriguez, J.; Leyva, I. A.; Candel, S.

    2012-05-01

    Supercritical pressure conditions designate a situation where the working fluid pressure is above the critical point. Among these conditions, it is interesting to identify a transcritical range which corresponds to cases where the pressure is above the critical point, but the injection temperature is below the critical value. This situation is of special interest because it raises fundamental issues which have technological relevance in the analysis of flows in liquid rocket engines. This situation is here envisaged by analyzing the behavior of a nitrogen shear coaxial jet comprising an inner stream injected at temperatures close to the critical temperature and a coaxial flow at a higher temperature. Experiments are carried out both in the absence of external modulation and by imposing a large amplitude transverse acoustic field. Real gas large eddy simulations are performed for selected experiments. The combination of experiments and calculations is used to evaluate effects of injector geometry and operating parameters. Calculations retrieve what is observed experimentally when the momentum flux ratio of the outer to the inner stream J= (ρ _eu_e^2)/(ρ _iu_i^2) is varied. Results exhibit the change in flow structure and the development of a recirculation region when this parameter exceeds a critical value. The instantaneous flow patterns for different momentum flux ratios are used in a second stage to characterize the dynamical behavior of the flow in terms of power spectral density of velocity and density fluctuations. Results obtained under acoustic modulation provide insight into mixing enhancement of coaxial streams with a view of its possible consequences in high frequency combustion instabilities. It is shown in particular that the presence of strong acoustic modulations notably reduces the high density jet core length, indicating an increased mixing efficiency. This behavior is more pronounced when the jet is placed at the location of maximum transverse

  4. Clinical Boot Camp: An Innovative Simulation Experience to Prepare Nursing Students for Obstetric and Pediatric Clinicals.

    PubMed

    Hogewood, Connie; Smith, Tedra; Etheridge, Sherita; Britt, Sylvia

    2015-01-01

    Obstetric and pediatric patients require unique specialized care not included in traditional adult health education. To prepare nursing students for clinical rotations beginning the second week of class, faculty developed an innovative one-day simulation seminar, the OB/PEDS Boot Camp, in which groups of students rotated through six stations of obstetric and pediatric simulation exercises. This article provides insight on the development and implementation of the OB/PEDS Boot Camp.

  5. Arsenopyrite weathering under conditions of simulated calcareous soil.

    PubMed

    Lara, René H; Velázquez, Leticia J; Vazquez-Arenas, Jorge; Mallet, Martine; Dossot, Manuel; Labastida, Israel; Sosa-Rodríguez, Fabiola S; Espinosa-Cristóbal, León F; Escobedo-Bretado, Miguel A; Cruz, Roel

    2016-02-01

    Mining activities release arsenopyrite into calcareous soils where it undergoes weathering generating toxic compounds. The research evaluates the environmental impacts of these processes under semi-alkaline carbonated conditions. Electrochemical (cyclic voltammetry, chronoamperometry, EIS), spectroscopic (Raman, XPS), and microscopic (SEM, AFM, TEM) techniques are combined along with chemical analyses of leachates collected from simulated arsenopyrite weathering to comprehensively examine the interfacial mechanisms. Early oxidation stages enhance mineral reactivity through the formation of surface sulfur phases (e.g., S n (2-)/S(0)) with semiconductor properties, leading to oscillatory mineral reactivity. Subsequent steps entail the generation of intermediate siderite (FeCO3)-like, followed by the formation of low-compact mass sub-micro ferric oxyhydroxides (α, γ-FeOOH) with adsorbed arsenic (mainly As(III), and lower amounts of As(V)). In addition, weathering reactions can be influenced by accessible arsenic resulting in the formation of a symplesite (Fe3(AsO4)3)-like compound which is dependent on the amount of accessible arsenic in the system. It is proposed that arsenic release occurs via diffusion across secondary α, γ-FeOOH structures during arsenopyrite weathering. We suggest weathering mechanisms of arsenopyrite in calcareous soil and environmental implications based on experimental data.

  6. Coke Reactivity in Simulated Blast Furnace Shaft Conditions

    NASA Astrophysics Data System (ADS)

    Haapakangas, Juho; Suopajärvi, Hannu; Iljana, Mikko; Kemppainen, Antti; Mattila, Olli; Heikkinen, Eetu-Pekka; Samuelsson, Caisa; Fabritius, Timo

    2016-08-01

    Despite the fact that H2 and H2O are always present in the gas atmosphere of a blast furnace shaft, their role in the solution-loss reactions of coke has not been thoroughly examined. This study focuses on how H2 and H2O affect the reaction behavior and whether a strong correlation can be found between reactivity in the conditions of the CRI test (Coke Reactivity Index) and various simulated blast furnace shaft gas atmospheres. Partial replacement of CO/CO2 with H2/H2O was found to significantly increase the reactivity of all seven coke grades at 1373 K (1100 °C). H2 and H2O, however, did not have a significant effect on the threshold temperature of gasification. The reactivity increasing effect was found to be temperature dependent and clearly at its highest at 1373 K (1100 °C). Mathematical models were used to calculate activation energies for the gasification, which were notably lower for H2O gasification compared to CO2 indicating the higher reactivity of H2O. The reactivity results in gas atmospheres with CO2 as the sole gasifying component did not directly correlate with reactivity results in gases also including H2O, which suggests that the widely used CRI test is not entirely accurate for estimating coke reactivity in the blast furnace.

  7. Simulation of cosmic irradiation conditions in thick target arrangements

    NASA Technical Reports Server (NTRS)

    Theis, S.; Englert, P.; Reedy, R. C.; Arnold, J. R.

    1986-01-01

    One approach to simulate 2-pi irradiation conditions of planetary surfaces which has been widely applied in the past are bombardments of so called thick targets. A very large thick target was exposed recently to 2.1 GeV protons at the Bevatron-Bevalac in Berkeley. In a 100x100x180 cm steel-surrounded granodiorite target radioactive medium and high energy spallation products of the incident primary and of secondary particles were analyzed along the beam axis down to depths of 140 g/cm(2) in targets such as Cu, Ni, Co, Fe, T, Si, SiO2 and Al. Activities of these nuclides were exclusively determined via instrumental gamma-ray spectroscopy. Relative yields of neutron capture and spallation products induced in Co and Cu targets during the thick target bombardment are shown as a function of depth. The majority of the medium energy products such as Co-58 from Co targets exhibit a maximum at shallow depths of 40-60 g/cm(2) and then decrease exponentially. In a comparable 600 MeV proton bombarded thick target such a slight maximum for medium energy products was not observed. Rather, Co-58 activities in Co decreased steadily with the highest activity at the surface. The activities of the n-capture product Co-60 increase steadily starting at the surface. This indicates the rapidly growing flux of low energy neutrons within the target.

  8. UV resistance of a halophilic archaeon in simulated martian conditions

    NASA Astrophysics Data System (ADS)

    ten Kate, Il; van Sluis, Ca; Selch, F.; Garry, Jrc; Stan-Lotter, H.; van Loosdrecht, M.; Ehrenfreund, P.

    Mars is thought to have had liquid water at its surface for geologically long periods. The progressive desiccation of the surface would have led to an increase in the salt content of remaining bodies of water. If life had developed on Mars, then some of the mechanisms evolved in terrestrial halophilic bacteria to cope with high salt content may have been similar to those existing in martian organisms. We have exposed samples of the halophilic Natronorubrum sp. strain HG-1 (Nr. strain HG-1) to conditions of ultraviolet radiation (UV) similar to those of the present-day martian environment. Furthermore, the effects of low temperature and low pressure on Nr. strain HG-1 have been investigated. To simulate a more Mars-like environment and investigate the effect of water in the atmosphere Nr. strain HG-1 has been irradiated when placed in a low pressure CO2 environment, static as well as flowing. The results, obtained by monitoring growth curves, indicate that the present UV radiation at the surface of Mars is a significant hazard for this organism. Exposure of the cells to high vacuum inactivates ~50 % of the cells. Freezing to -20 ° C and -80 ° C kills ~80 % of the cells. When desiccated and embedded in a salt crust, cells are somewhat more resistant to UV radiation than when suspended in an aqueous solution. The cell inactivation by UV is wavelength dependent. It cannot be excluded that they can survive when embedded in the soil or buried underneath rocks.

  9. DSMC Simulations of Ballute Aerothermodynamics Under Hypersonic Rarefied Conditions

    NASA Technical Reports Server (NTRS)

    Moss, James N.

    2005-01-01

    This paper presents computational results obtained with the direct simulation Monte Carlo (DSMC) method for towed ballute applications. A ballute is an inflatable drag device that can be used to create a large amount of drag at high altitudes. Consequently, ballutes provide a potential technology for achieving aerocapture when the primary spacecraft velocity reduction (Delta V) is achieved at much higher altitudes than with the conventional rigid aeroshell. Since the Delta V is achieved at relatively high altitudes, rarefaction can be significant and is the motivation for the current study with the DSMC method. Computed surface and flow-field results are presented for a toroidal ballute, isolated tethers when exposed to free-stream flow conditions, and the flow interactions resulting from a toroidal ballute when towed by a six meter diameter Mars Pathfinder shaped (without tethers) spacecraft. All results presented are for Earth entry at velocities of 14 to 7 km/s (primary focus is at 8.55 km/s, same as some previous Titan aerocapture studies) and altitudes of 200 to 100 km. Variations of drag and heating coefficients as a function of rarefaction are presented. A description of the flow structure is provided and also an explanation of how it is affected by shock interactions produced solely by the ballute and those resulting from the two body combination of towed ballute and spacecraft is also given.

  10. Simulation of fatigue crack growth under large scale yielding conditions

    NASA Astrophysics Data System (ADS)

    Schweizer, Christoph; Seifert, Thomas; Riedel, Hermann

    2010-07-01

    A simple mechanism based model for fatigue crack growth assumes a linear correlation between the cyclic crack-tip opening displacement (ΔCTOD) and the crack growth increment (da/dN). The objective of this work is to compare analytical estimates of ΔCTOD with results of numerical calculations under large scale yielding conditions and to verify the physical basis of the model by comparing the predicted and the measured evolution of the crack length in a 10%-chromium-steel. The material is described by a rate independent cyclic plasticity model with power-law hardening and Masing behavior. During the tension-going part of the cycle, nodes at the crack-tip are released such that the crack growth increment corresponds approximately to the crack-tip opening. The finite element analysis performed in ABAQUS is continued for so many cycles until a stabilized value of ΔCTOD is reached. The analytical model contains an interpolation formula for the J-integral, which is generalized to account for cyclic loading and crack closure. Both simulated and estimated ΔCTOD are reasonably consistent. The predicted crack length evolution is found to be in good agreement with the behavior of microcracks observed in a 10%-chromium steel.

  11. Numerical Simulation of HIWC Conditions with the Terminal Area Simulation System

    NASA Technical Reports Server (NTRS)

    Proctor, Fred H.; Switzer, George F.

    2016-01-01

    Three-dimensional, numerical simulation of a mesoconvective system is conducted in order to better understand conditions associated with High Ice Water Content (HIWC) and its threat to aviation safety. Although peak local values of ice water content may occur early in the storm lifetime, large areas of high concentrations expand with time and persist even when the storm tops begin to warm. The storm canopy which contains HIWC, has low radar reflectivity factor and is fed by an ensemble of regenerating thermal pulses.

  12. Developing an equipment library for clinical skills and simulation training.

    PubMed

    Barrott, Joanne; Hope, Angela

    2011-08-01

    This article describes the the development of a regional equipment library for clinical skills and simulation training. This was a project undertaken to address a reduction in the available funding for the purchasing of clinical skills equipment throughout the Yorkshire and Humber region. It was envisaged that utilizing regionally accessible equipment through the development of an equipment library could support clinical areas with no other means of acquiring the necessary equipment for training. A consultation exercise met with initial concerns around the cost of some of this equipment and who would be responsible for the repair, transportation costs and maintenance. A SWOT analysis identified how these concerns may be addressed and processes of developing a database, tracking usage and auditing of the service emerged.

  13. DNA damage under simulated extraterrestrial conditions in bacteriophage T7

    NASA Astrophysics Data System (ADS)

    Fekete, A.; Kovács, G.; Hegedüs, M.; Módos, K.; Rontó, Gy.; Lammer, H.; Panitz, C.

    The experiment ``Phage and uracil response'' (PUR) will be accommodated in the EXPOSE facility of the ISS aiming to examine and quantify the effect of specific space conditions on bacteriophage T7 and isolated T7 DNA thin films. To achieve this new method was elaborated for the preparation of DNA and nucleoprotein thin films (1). During the EXPOSE Experiment Verification Tests (EVT) the samples were exposed to vacuum (10 -6 Pa), to monochromatic (254 nm) and polychromatic (200-400 nm) UV radiation in air as well in simulated space vacuum. Using neutral density (ND) filters dose-effect curves were performed in order to define the maximum doses tolerated, and we also studied the effect of temperature in vacuum as well as the influence of temperature fluctuations. We obtained substantial evidence that DNA lesions (e.g. strand breaks, DNA-protein cross-links, DNA-DNA cross-links) accumulate throughout exposure. DNA damage was determined by quantitative PCR using 555 bp and 3826 bp fragments of T7 DNA (2) and by neutral and alkaline agarose gel electrophoresis; the structural/chemical effects were analyzed by spectroscopic and microscopical methods. Characteristic changes in the absorption spectrum, in the electrophoretic pattern of DNA and the decrease of the amount of the PCR products have been detected indicating the damage of isolated and intraphage DNA. Preliminary results suggest a synergistic action of space vacuum and UV radiation with DNA being the critical target. Fekete et al. J. Luminescence 102-103, 469-475, 2003 Hegedüs et al. Photochem. Photobiol. 78, 213-219, 2003

  14. Synthesis of hydrogen cyanide under simulated hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Pinedo-González, Paulina

    Nitrogen is a fundamental element for life, where is present in structural (e.g., proteins), catalytic (e.g., enzymes and ribozymes), energy transfer (e.g., ATP) and information storage (RNA and DNA) biomolecules. Atmospheric and planetary models suggest that nitrogen was abundant in the early atmospheres of Earth as dinitrogen (N2 ), an inert gas under normal atmospheric conditions. To be available for prebiotic synthesis it must be converted into hydrogen cyanide (HCN), ammonia (NH3 ) and/or nitric oxide (NO), in a process referred to as nitrogen fixation. Due to the strength of the triple bond in N2 , nitrogen fixation, while thermodynamically favored is kinetically restricted. In a reducing atmosphere dominated by CH4 -N2 , thunderstorm lightning efficiently produces HCN and NH3 (Stribling and Miller, 1987). Nevertheless, photochemical and geochemical constraints strongly suggest that the early atmosphere was weakly reducing, dominated by CO2 and N2 with traces of CH4 , CO, and H2 (Kasting, 1993). Under these conditions, HCN is no longer synthesized in the lightning channel and instead NO is formed (Navarro-Gonźlez, et al., 2001). In volcanic plumes, where magmatic gases a were more reducing than in the atmosphere, NO can also be formed by the lava heat (Mather et al., 2004) or volcanic lightning (Navarro-Gonźlez et al., 1998). Surprisingly, dinitrogen can be a reduced to NH3 in hydrothermal systems (Brandes et al., 1998), but the formation of HCN and its derivates were not investigated. The present work explores the possibility of the formation of HCN as well as other nitrile derivatives catalyzed by mineral surfaces in hydrothermal vents. To simulate a hydrothermal atmosphere, the experiments were carried out in a stainless steel Parr R minireactor with a 0.1 M NH4 HCO3 solution (200 ml) with or without a mineral surface exposed at 1 bar at temperatures ranging from 100 to 375° C. Different mineral matrices are been investigated. Our preliminary results

  15. Teaching Nursing Leadership: Comparison of Simulation versus Traditional Inpatient Clinical.

    PubMed

    Gore, Teresa N; Johnson, Tanya Looney; Wang, Chih-hsuan

    2015-04-30

    Nurse educators claim accountability to ensure their students are prepared to assume leadership responsibilities upon graduation. Although front-line nurse leaders and nurse executives feel new graduates are not adequately prepared to take on basic leadership roles, professional nursing organizations such as the American Nurses Association (ANA) and the Association of Colleges of Nursing (AACN) deem leadership skills are core competencies of new graduate nurses. This study includes comparison of a leadership-focused multi-patient simulation and the traditional leadership clinical experiences in a baccalaureate nursing leadership course. The results of this research show both environments contribute to student learning. There was no statistical difference in the overall score. Students perceived a statistically significant difference in communication with patients in the traditional inpatient environment. However, the students perceived a statistical significant difference in teaching-learning dyad toward simulation.

  16. 42 CFR 485.638 - Conditions of participation: Clinical records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... clinical laboratory services, and consultative findings; (iii) All orders of doctors of medicine or... doctor of medicine or osteopathy or other health care professional. (b) Standard: Protection of...

  17. 42 CFR 485.638 - Conditions of participation: Clinical records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... clinical laboratory services, and consultative findings; (iii) All orders of doctors of medicine or... doctor of medicine or osteopathy or other health care professional. (b) Standard: Protection of...

  18. 42 CFR 485.721 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... information and retrieval of records for research or administrative action. (f) Standard: Location and... efficient processing of clinical records (reviewing, indexing, filing, and prompt retrieval)....

  19. 42 CFR 485.721 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... information and retrieval of records for research or administrative action. (f) Standard: Location and... efficient processing of clinical records (reviewing, indexing, filing, and prompt retrieval)....

  20. 42 CFR 485.721 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... information and retrieval of records for research or administrative action. (f) Standard: Location and... efficient processing of clinical records (reviewing, indexing, filing, and prompt retrieval)....

  1. Water ice nucleation characteristics of JSC Mars-1 regolith simulant under simulated Martian atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Phebus, Bruce D.; Johnson, Alexandria V.; Mar, Brendan; Stone, Bradley M.; Colaprete, Anthony; Iraci, Laura T.

    2011-04-01

    Water ice clouds in the Martian atmosphere are governed by parameters such as number density and particle size distribution that in turn affect how they influence the climate. With some of the underlying properties of cloud formation well known only for Earth, extrapolations to Mars are potentially misleading. We report here continued laboratory experiments to identify critical onset conditions for water ice formation under Martian cloud forming temperatures and water partial pressures (155-182 K, 7.6 × 10-5 to 7.7 × 10-3 Pa H2O). By observing the 3 μm infrared band to monitor nucleation and growth, we observe significant temperature dependence in the nucleation of ice on JSC Mars-1 regolith simulant, with critical saturation ratios, Scrit, as high as 3.8 at 155 K. At temperatures below ˜180 K, ice nucleation on JSC Mars-1 requires significant supersaturation, potentially impacting the Martian hydrological cycle.

  2. 42 CFR 485.60 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... of participation: Clinical records. The facility must maintain clinical records on all patients in... sufficient information to identify the patient clearly and to justify the diagnosis and treatment. Entries in... countersigned by the corresponding professional. Documentation on each patient must be consolidated into...

  3. 42 CFR 485.60 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of participation: Clinical records. The facility must maintain clinical records on all patients in... sufficient information to identify the patient clearly and to justify the diagnosis and treatment. Entries in... countersigned by the corresponding professional. Documentation on each patient must be consolidated into...

  4. 42 CFR 485.60 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of participation: Clinical records. The facility must maintain clinical records on all patients in... sufficient information to identify the patient clearly and to justify the diagnosis and treatment. Entries in... countersigned by the corresponding professional. Documentation on each patient must be consolidated into...

  5. 42 CFR 485.60 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of participation: Clinical records. The facility must maintain clinical records on all patients in... sufficient information to identify the patient clearly and to justify the diagnosis and treatment. Entries in... countersigned by the corresponding professional. Documentation on each patient must be consolidated into...

  6. [State of clinical and neurologic condition of Temirtau inhabitants].

    PubMed

    Battakova, Sh B; Amanbekov, U A; Mukhametzhanova, S E; Fazylova, M-D A; Miianova, G A; Shraĭmanov, B S; Abdikulova, A A

    2011-01-01

    The article covers results of studies concerning psychologic and clinical neurologic state of Temirtau inhabitants. Early clinical forms of cerebro-vascular diseases were more frequent among males, but cryptogenic encephalopathies were more prevalent among females. Among the males examined, the early clinical signs of cerebro-vascular diseases were seen in all age groups, more often at the age of 20-29. Among the females, cryptogenic encephalopathies were more often at the age over 40. Early clinical forms of cerebro-vascular diseases and cryptogenic encephalopathies were associated with asthenic, astheno-hypochondriac, astheno-depressive syndrome and vegetative dysfunction syndrome. The group with early clinical signs of cerebro-vascular diseases was characterized by prevalent asthenic syndrome, but the cryptogenic encephalopathy group had more often astheno-hypochondriac syndrome.

  7. Desert Cyanobacteria under simulated space and Martian conditions

    NASA Astrophysics Data System (ADS)

    Billi, D.; Ghelardini, P.; Onofri, S.; Cockell, C. S.; Rabbow, E.; Horneck, G.

    2008-09-01

    The environment in space and on planets such as Mars, can be lethal to living organisms and high levels of tolerance to desiccation, cold and radiation are needed for survival: rock-inhabiting cyanobacteria belonging to the genus Chroococcidiopsis can fulfil these requirements [1]. These cyanobacteria constantly appear in the most extreme and dry habitats on Earth, including the McMurdo Dry Valleys (Antarctica) and the Atacama Desert (Chile), which are considered the closest terrestrial analogs of two Mars environmental extremes: cold and aridity. In their natural environment, these cyanobacteria occupy the last refuges for life inside porous rocks or at the stone-soil interfaces, where they survive in a dry, dormant state for prolonged periods. How desert strains of Chroococcidiopsis can dry without dying is only partially understood, even though experimental evidences support the existence of an interplay between mechanisms to avoid (or limit) DNA damage and repair it: i) desert strains of Chroococcidiopsis mend genome fragmentation induced by ionizing radiation [2]; ii) desiccation-survivors protect their genome from complete fragmentation; iii) in the dry state they show a survival to an unattenuated Martian UV flux greater than that of Bacillus subtilis spores [3], and even though they die following atmospheric entry after having orbited the Earth for 16 days [4], they survive to simulated shock pressures up to 10 GPa [5]. Recently additional experiments were carried out at the German Aerospace Center (DLR) of Cologne (Germany) in order to identify suitable biomarkers to investigate the survival of Chroococcidiopsis cells present in lichen-dominated communities, in view of their direct and long term space exposition on the International Space Station (ISS) in the framework of the LIchens and Fungi Experiments (LIFE, EXPOSEEuTEF, ESA). Multilayers of dried cells of strains CCMEE 134 (Beacon Valley, Antarctica), and CCMEE 123 (costal desert, Chile ), shielded by

  8. Simulated Patients vs. Standardized Patients in Objective Structured Clinical Examinations

    PubMed Central

    Austin, Zubin; Gregory, Paul; Tabak, Diana

    2006-01-01

    Objectives To describe the use of patient-actors as educators in a senior-level pharmacy practice course, and to contrast the value and application of “standardized patient” and “simulated patient” educational methodologies. Design The objective structured clinical examination (OSCE) of the licensing examination were utilized during and at the end of the course along with external assessment to determine the impact of this educational methodology. Interviews with a randomly selected cohort of 14 students were undertaken 3 years after graduation and licensure to evaluate long-term impact of this course. Assessment Overall, students responded positively to the shift from “standardized” patients to “simulated” patients, recognizing their value in teaching clinical and pharmaceutical care skills. Concerns were expressed regarding objectivity in assessment and individual grading. Over 98% of students successfully passed the OSCE component of the licensing examination. Long-term follow-up suggests students valued this approach to education and that it provided them with a foundation for better understanding of the psychosocial needs of patients in practice. Conclusions Simulated-patient educators can play an important role in the pharmacy curriculum, and can complement practitioner-educators in providing students with a real-world context for understanding complex patient care needs. PMID:17149448

  9. Technology for enhancing chest auscultation in clinical simulation.

    PubMed

    Ward, Jeffrey J; Wattier, Bryan A

    2011-06-01

    The ability to use an acoustic stethoscope to detect lung and/or heart sounds, and then to then communicate one's interpretation of those sounds is an essential skill for many medical professionals. Interpretation of lung and heart sounds, in the context of history and other examination findings, often aids the differential diagnosis. Bedside assessment of changing auscultation findings may also guide treatment. Learning lung and heart auscultation skills typically involves listening to pre-recorded normal and adventitious sounds, often followed by laboratory instruction to guide stethoscope placement, and finally correlating the sounds with the associated pathophysiology and pathology. Recently, medical simulation has become an important tool for teaching prior to clinical practice, and for evaluating bedside auscultation skills. When simulating cardiovascular or pulmonary problems, high-quality lung and heart sounds should be able to accurately corroborate other findings such as vital signs, arterial blood gas values, or imaging. Digital audio technology, the Internet, and high-fidelity simulators have increased opportunities for educators and learners. We review the application of these technologies and describe options for reproducing lung and heart sounds, as well as their advantages and potential limitations.

  10. Parametric initial conditions for core-collapse supernova simulations

    NASA Astrophysics Data System (ADS)

    Suwa, Yudai; Müller, Ewald

    2016-08-01

    We investigate a method to construct parametrized progenitor models for core-collapse supernova simulations. Different from all modern core-collapse supernova studies, which rely on progenitor models from stellar evolution calculations, we follow the methodology of Baron & Cooperstein to construct initial models. Choosing parametrized spatial distributions of entropy and electron fraction as a function of mass coordinate and solving the equation of hydrostatic equilibrium, we obtain the initial density structures of our progenitor models. First, we calculate structures with parameters fitting broadly the evolutionary model s11.2 of Woosley et al. (2002). We then demonstrate the reliability of our method by performing general relativistic hydrodynamic simulations in spherical symmetry with the isotropic diffusion source approximation to solve the neutrino transport. Our comprehensive parameter study shows that initial models with a small central entropy (≲0.4 kB nucleon-1) can explode even in spherically symmetric simulations. Models with a large entropy (≳6 kB nucleon-1) in the Si/O layer have a rather large explosion energy (˜4 × 1050 erg) at the end of the simulations, which is still rapidly increasing.

  11. Sensitivity of a Simulated Derecho Event to Model Initial Conditions

    NASA Astrophysics Data System (ADS)

    Wang, Wei

    2014-05-01

    Since 2003, the MMM division at NCAR has been experimenting cloud-permitting scale weather forecasting using Weather Research and Forecasting (WRF) model. Over the years, we've tested different model physics, and tried different initial and boundary conditions. Not surprisingly, we found that the model's forecasts are more sensitive to the initial conditions than model physics. In 2012 real-time experiment, WRF-DART (Data Assimilation Research Testbed) at 15 km was employed to produce initial conditions for twice-a-day forecast at 3 km. On June 29, this forecast system captured one of the most destructive derecho event on record. In this presentation, we will examine forecast sensitivity to different model initial conditions, and try to understand the important features that may contribute to the success of the forecast.

  12. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... complexity testing; clinical consultant. 493.1415 Section 493.1415 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1415 Condition: Laboratories performing moderate complexity testing; clinical consultant....

  13. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... complexity testing; clinical consultant. 493.1415 Section 493.1415 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1415 Condition: Laboratories performing moderate complexity testing; clinical consultant....

  14. A Large Eddy Simulation Study for upstream wind energy conditioning

    NASA Astrophysics Data System (ADS)

    Sharma, V.; Calaf, M.; Parlange, M. B.

    2013-12-01

    The wind energy industry is increasingly focusing on optimal power extraction strategies based on layout design of wind farms and yaw alignment algorithms. Recent field studies by Mikkelsen et al. (Wind Energy, 2013) have explored the possibility of using wind lidar technology installed at hub height to anticipate incoming wind direction and strength for optimizing yaw alignment. In this work we study the benefits of using remote sensing technology for predicting the incoming flow by using large eddy simulations of a wind farm. The wind turbines are modeled using the classic actuator disk concept with rotation, together with a new algorithm that permits the turbines to adapt to varying flow directions. This allows for simulations of a more realistic atmospheric boundary layer driven by a time-varying geostrophic wind. Various simulations are performed to investigate possible improvement in power generation by utilizing upstream data. Specifically, yaw-correction of the wind-turbine is based on spatio-temporally averaged wind values at selected upstream locations. Velocity and turbulence intensity are also considered at those locations. A base case scenario with the yaw alignment varying according to wind data measured at the wind turbine's hub is also used for comparison. This reproduces the present state of the art where wind vanes and cup anemometers installed behind the rotor blades are used for alignment control.

  15. Laboratory simulations of NAT formation approaching stratospheric conditions

    NASA Technical Reports Server (NTRS)

    Marti, James; Mauersberger, Konrad

    1994-01-01

    Previous laboratory studies have established the stability conditions of nitric acid trihydrate (NAT), of which type 1 polar stratospheric cloud (PSC 1) particles are thought to be composed. However, NAT samples in lab studies were almost always formed under conditions very different from those of the stratosphere. In order to better understand the in situ growth of PSC 1 particle populations, samples of water and nitric acid were deposited under conditions of temperature and pressure which more closely approximate the polar stratosphere. The compositions of the solids, measured shortly after deposition, depended on the H2O:HNO3 ratio in the vapor from which the solids were condensed. Solids formed from vapor mixtures that approached stratospheric contained significantly less HNO3 than the 25 mol percent expected of NAT.

  16. 42 CFR 485.721 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.721 Condition of...) Identification data and consent forms. (3) Medical history. (4) Report of physical examinations, if any....

  17. 42 CFR 485.721 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Providers of Outpatient Physical Therapy and Speech-Language Pathology Services § 485.721 Condition of...) Identification data and consent forms. (3) Medical history. (4) Report of physical examinations, if any....

  18. Potential workload in applying clinical practice guidelines for patients with chronic conditions and multimorbidity: a systematic analysis

    PubMed Central

    Buffel du Vaure, Céline; Ravaud, Philippe; Baron, Gabriel; Barnes, Caroline; Gilberg, Serge; Boutron, Isabelle

    2016-01-01

    Objectives To describe the potential workload for patients with multimorbidity when applying existing clinical practice guidelines. Design Systematic analysis of clinical practice guidelines for chronic conditions and simulation modelling approach. Data sources National Guideline Clearinghouse index of US clinical practice guidelines. Study selection We identified the most recent guidelines for adults with 1 of 6 prevalent chronic conditions in primary care (ie hypertension, diabetes, coronary heart disease (CHD), chronic obstructive pulmonary disease (COPD), osteoarthritis and depression). Data extraction From the guidelines, we extracted all recommended health-related activities (HRAs) such as drug management, self-monitoring, visits to the doctor, laboratory tests and changes of lifestyle for a patient aged 45–64 years with moderate severity of conditions. Simulation modelling approach For each HRA identified, we performed a literature review to determine the potential workload in terms of time spent on this HRA. Then, we used a simulation modelling approach to estimate the potential workload needed to comply with these recommended HRAs for patients with several of these chronic conditions. Results Depending on the concomitant chronic condition, patients with 3 chronic conditions complying with all the guidelines would have to take a minimum of 6 to a maximum of 13 medications per day, visit a health caregiver a minimum of 1.2 to a maximum of 5.9 times per month and spend a mean (SD) of 49.6 (27.3) to 71.0 (34.5) h/month in HRAs. The potential workload increased greatly with increasing number of concomitant conditions, rising to 18 medications per day, 6.6 visits per month and 80.7 (35.8) h/month in HRAs for patients with 6 chronic conditions. PMID:27006342

  19. Coupled Simulation of Heart Valves: Applications to Clinical Practice.

    PubMed

    Bakhaty, Ahmed A; Mofrad, Mohammad R K

    2015-07-01

    The last few decades have seen great advances in the understanding of heart valves, and consequently, in the development of novel treatment modalities and surgical procedures for valves afflicted by disease. This is due in part to the profound advancements in computing technology and noninvasive medical imaging techniques that have made it possible to numerically model the complex heart valve systems characterized by distinct features at different length scales and various interacting processes. In this article, we highlight the importance of explicitly coupling these multiple scales and diverse processes to accurately simulate the true behavior of the heart valves, in health and disease. We examine some of the computational modeling studies that have a direct consequence on clinical practice.

  20. Experiments and Numerical Simulation of Mixing under Supercritical Conditions (PREPRINT)

    DTIC Science & Technology

    2011-02-08

    where accurate descriptions of the fluid state are derived from various types of equations [1, 71]. The present simulations rely on the Peng - Robinson equation of... Robinson equation of state cp Constant pressure specific heat cv Constant volume specific heat Cw WALE model constant di Inner jet diameter E Total energy...density ρe Outer jet injection density ρi Inner jet injection density τ Viscous-stress tensor τ t SGS stress tensor a, b, c Coefficients for the Peng

  1. Survival of bacterial spores under some simulated lunar surface conditions.

    PubMed

    Horneck, G; Bucker, H; Wollenhaupt, H

    1971-01-01

    Spores of Bacillus subtilis were exposed to simulated lunar environmental factors, in order to estimate the chance of living matter to survive on the moon. Vacuum, radiation and extreme temperature were selected and their individual and combined influence was tested. High vacuum up to 2 x 10(-7) torr and ultra-high vacuum up to 5 x 10(-9) torr, ultraviolet rays (254 nm) and a temperature of 80 degrees C were used. The results were compared with those of experiments on vegetative cells.

  2. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such as the tailpipe emissions, air conditioning compressor load, and fuel economy. (2) For any...

  3. Computer simulation of effect of conditions on discharge-excited high power gas flow CO laser

    NASA Astrophysics Data System (ADS)

    Ochiai, Ryo; Iyoda, Mitsuhiro; Taniwaki, Manabu; Sato, Shunichi

    2017-01-01

    The authors have developed the computer simulation codes to analyze the effect of conditions on the performances of discharge excited high power gas flow CO laser. The six be analyzed. The simulation code described and executed by Macintosh computers consists of some modules to calculate the kinetic processes. The detailed conditions, kinetic processes, results and discussions are described in this paper below.

  4. Orbital-Free Molecular Dynamics Simulations at Extreme Conditions

    NASA Astrophysics Data System (ADS)

    Kress, J. D.; Collins, L. A.; Ticknor, C.

    2015-06-01

    Large-scale molecular dynamics (MD) simulations in an orbital-free (OF) density-functional theory (DFT) formulation have been performed for pure and mixed species over a broad range of temperatures (T) and densities (ρ) that includes the warm, dense matter and high-energy density physics regimes. A finite-temperature Thomas-Fermi-Dirac form with a local-density exchange-correlation potential and a regularized electron-ion interaction represents the quantum nature of the electrons. In particular, we examine the efficacy of the OFMD approach as an effective bridge between Kohn-Sham DFT MD at low temperatures and simple, fully-ionized plasma models at high temperatures. Comparisons against intermediate-range constructions such as the Yukawa and one-component plasmas are also made. We examine the mass transport (diffusion, viscosity) properties of various systems, ranging from light to heavy elements, including lithium hydride (LiH), mixtures of LiH with uranium, mixtures of deuterium-tritium (DT) with plutonium and mixtures of DT with plastic (CH). The OFMD mass transport results have been fitted to simple functions of ρ and T suitable for use in hydrodynamics simulation codes.

  5. Nitrogen release from rock and soil under simulated field conditions

    USGS Publications Warehouse

    Holloway, J.M.; Dahlgren, R.A.; Casey, W.H.

    2001-01-01

    A laboratory study was performed to simulate field weathering and nitrogen release from bedrock in a setting where geologic nitrogen has been suspected to be a large local source of nitrate. Two rock types containing nitrogen, slate (1370 mg N kg-1) and greenstone (480 mg N kg-1), were used along with saprolite and BC horizon sand from soils derived from these rock types. The fresh rock and weathered material were used in batch reactors that were leached every 30 days over 6 months to simulate a single wet season. Nitrogen was released from rock and soil materials at rates between 10-20 and 10-19 mo1 N cm-2 s-1. Results from the laboratory dissolution experiments were compared to in situ soil solutions and available mineral nitrogen pools from the BC horizon of both soils. Concentrations of mineral nitrogen (NO3- + NH4+) in soil solutions reached the highest levels at the beginning of the rainy season and progressively decreased with increased leaching. This seasonal pattern was repeated for the available mineral nitrogen pool that was extracted using a KCl solution. Estimates based on these laboratory release rates bracket stream water NO3-N fluxes and changes in the available mineral nitrogen pool over the active leaching period. These results confirm that geologic nitrogen, when present, may be a large and reactive pool that may contribute as a non-point source of nitrate contamination to surface and ground waters. ?? 2001 Elsevier Science B.V. All rights reserved.

  6. Simulated prostate biopsy: prostate cancer distribution and clinical correlation

    NASA Astrophysics Data System (ADS)

    Bauer, John J.; Zeng, Jianchao; Zhang, Wei; Sesterhenn, Isabell A.; Dean, Robert; Moul, Judd W.; Mun, Seong K.

    2000-04-01

    Our group has recently obtained data based upon whole- mounted step-sectioned radical prostatectomy specimens using a 3D computer assisted prostate biopsy simulator that suggests an increased detection rate is possible using laterally placed biopsies. A new 10-core biopsy pattern was demonstrated to be superior to the traditional sextant biopsy. This patter includes the traditional sextant biopsy cores and four laterally placed biopsies in the right and left apex and mid portion of the prostate gland. The objective of this study is to confirm the higher prostate cancer defection rate obtained using our simulated 10-core biopsy pattern in a small clinical trial. We retrospectively reviewed 35 consecutive patients with a pathologic diagnosis of prostate cancer biopsied by a single urologist using the 10-core prostate biopsy patterns were compared with respect to prostate cancer detection rate. Of the 35 patients diagnosed with prostate cancer, 54.3 percent were diagnosed when reviewing the sextant biopsy data only. Review of the 10-core pattern revealed that an additional 45.7 percent were diagnosed when reviewing the sextant biopsy data only. Review of the 10-core pattern revealed that an additional 45.7 percent of patients were diagnosed solely with the laterally placed biopsies. Our results suggest that biopsy protocols that use laterally placed biopsies based upon a five region anatomical model are superior to the routinely used sextant prostate biopsy pattern.

  7. Thermographic monitoring of materials under simulated reentry conditions

    NASA Technical Reports Server (NTRS)

    White, Susan M.; Burleigh, Douglas

    1991-01-01

    Thermography can be used to measure surface temperature gradients graphically, and can be used under conditions where the direct measurement of temperature at all desired points, using thermocouples or resistance temperature detectors (RTDs), is either difficult or impossible. The use of thermographic monitoring during a series of arc-jet tests is described. Described in this work are the issues that influence interpretation of the thermographic measurements under these conditions, including the calculation of effective emittance and window transmittance from the spectral properties of the materials in order to calculate the temperature distribution of a surface directly from the measured radiance. Comparison of the surface temperatures measured using thermocouples and the temperatures derived from thermographic measurements show good agreement. The data gathered will be used to evaluate important test parameters such as the heating distribution across the surface of a heat shield test model and at steps on the model surface.

  8. Stability and activity of an Enterobacter aerogenes-specific bacteriophage under simulated gastro-intestinal conditions.

    PubMed

    Verthé, K; Possemiers, S; Boon, N; Vaneechoutte, M; Verstraete, W

    2004-09-01

    A bacteriophage, designated UZ1 and showing lytic activity against a clinically important strain (BE1) of Enterobacter aerogenes was isolated from hospital sewage. The stability and lytic activity against this strain under simulated gastro-intestinal conditions was evaluated. After addition of bacteriophage UZ1 to a liquid feed at gastric pH 2, the phage was immediately inactivated and could not be recovered. However, by use of an antacid to neutralize stomach acidity, no significant changes in phage titer were observed after 2 h incubation at 37 degrees C. After supplementing pancreatic juice and further incubation for 4 h, the phage titer remained stable. The persistence of UZ1 in a mixed microbial ecosystem that was representative for the large intestine was monitored using an in vitro simulation of the human intestinal microbial ecosystem. A pulse administration of bacteriophage UZ1 at a concentration of 10(5) plaque-forming units (PFU)/ml to reactor 3 (which simulates the ascending colon) showed that, in the absence of the host, bacteriophage UZ1 persisted for 13 days in the simulated colon, while the theoretical washout was calculated at 16 days. To assess its lytic activity in an intestinal microbial ecosystem, a green fluorescent protein (gfp)-labeled E. aerogenes BE1 strain was constructed and gfp-specific primers were designed in order to quantify the host strain using real-time PCR. It was observed that bacteriophage UZ1 was able to replicate and showed lytic activity against E. aerogenes BE1/ gfp in an intestinal microbial ecosystem. Indeed, after 17 h a 2 log unit reduction of E. aerogenes BE1/ gfp was measured as compared with the assay without bacteriophage UZ1, while the phage titer increased by 2 log units at an initial multiplicity of infection of 0.07 PFU/colony-forming unit. This is the first report of an in vitro model to study bacteriophage activity in the complex intestinal microbial community.

  9. New approximate boundary conditions for large eddy simulations of wall-bounded flows

    NASA Technical Reports Server (NTRS)

    Piomelli, Ugo; Ferziger, Joel; Moin, Parviz; Kim, John

    1989-01-01

    Two new approximate boundary conditions have been applied to the large eddy simulation of channel flow with and without transpiration. These new boundary conditions give more accurate results than those previously in use, and allow significant reduction of the required CPU time over simulations in which no-slip conditions are applied. Mean velocity profiles and turbulence intensities compare well both with experimental data and with the results of resolved simulations. The influence of the approximate boundary conditions remains confined near the point of application and does not affect the turbulence statistics in the core of the flow.

  10. Computer simulations of planetary accretion dynamics: Sensitivity to initial conditions

    NASA Technical Reports Server (NTRS)

    Isaacman, R.; Sagan, C.

    1976-01-01

    The implications and limitations of program ACRETE were tested. The program is a scheme based on Newtonian physics and accretion with unit sticking efficiency, devised to simulate the origin of the planets. The dependence of the results on a variety of radial and vertical density distribution laws, the ratio of gas to dust in the solar nebula, the total nebular mass, and the orbital eccentricity of the accreting grains was explored. Only for a small subset of conceivable cases are planetary systems closely like our own generated. Many models have tendencies towards one of two preferred configurations: multiple star systems, or planetary systems in which Jovian planets either have substantially smaller masses than in our system or are absent altogether. But for a wide range of cases recognizable planetary systems are generated - ranging from multiple star systems with accompanying planets, to systems with Jovian planets at several hundred AU, to single stars surrounded only by asteroids.

  11. Nursing Students' Perceptions of Satisfaction and Self-Confidence with Clinical Simulation Experience

    ERIC Educational Resources Information Center

    Omer, Tagwa

    2016-01-01

    Nursing and other health professionals are increasingly using simulation as a strategy and a tool for teaching and learning at all levels that need clinical training. Nursing education for decades used simulation as an integral part of nursing education. Recent studies indicated that simulation improves nursing knowledge, clinical practice,…

  12. Computer-Based versus High-Fidelity Mannequin Simulation in Developing Clinical Judgment in Nursing Education

    ERIC Educational Resources Information Center

    Howard, Beverly J.

    2013-01-01

    The purpose of this study was to determine if students learn clinical judgment as effectively using computer-based simulations as when using high-fidelity mannequin simulations. There was a single research questions for this study: What is the difference in clinical judgment between participants completing high-fidelity human simulator mannequin…

  13. Physical Conditions and Prisoner Deaths: A Clinical Report.

    ERIC Educational Resources Information Center

    Neithercutt, M. G.; Zajac, Patricia

    1995-01-01

    The conditions under which prisoners are housed has long been the subject of scholarly discourse. Rare are opportunities to inquire into situations where the environment can clearly be seen to be a problem of fatal proportions. This report considers the deaths of three inmates at the California Medical Facility, Vacaville, spotlighting the…

  14. Reactions of aminomalononitrile with electrophiles. [simulating prebiotic conditions

    NASA Technical Reports Server (NTRS)

    Thanassi, J. W.

    1975-01-01

    Aminomalononitrile (HCN trimer) reacts with electrophiles such as aldehydes and acrylonitrile under very mild conditions of temperature and pH to produce intermediates which, after acid hydrolysis, yield amino acids. The following amino acids have been identified and quantitated: glycine, D,L-erythro- and D,L-threo-beta-hydroxyaspartic acids, D,L glutamic acid, and D,L-threonine and allo-threonine. The mechanism of their formation and the possible significance of these reactions in prebiotic syntheses are discussed.

  15. Inorganic nitrogen reduction and stability under simulated hydrothermal conditions.

    PubMed

    Brandes, Jay A; Hazen, Robert M; Yoder, Hatten S

    2008-12-01

    Availability of reduced nitrogen is considered a prerequisite for the genesis of life from prebiotic precursors. Most atmospheric and oceanic models for the Hadean Earth predict a mildly oxidizing environment that is conducive to the formation and stability of only oxidized forms of nitrogen. A possible environment where reduction of oxidized nitrogen to ammonium has been speculated to occur is aqueous hydrothermal systems. We examined a suite of transition metal oxides and sulfides for their ability to reduce nitrate and nitrite, as well as oxidize ammonia, under hot (300 degrees C) high-pressure (50-500 MPa) aqueous conditions. In general, iron sulfides exhibited the most rapid and complete conversion noted, followed by nickel and copper sulfides to a much lower degree. Of the oxides examined, only magnetite exhibited any ability to reduce NO(3)(-) or NO(2)(-). Ammonium was stable or exhibited small losses (<20%) in contact with all the mineral phases and conditions tested. The results support the idea that hydrothermal systems could have provided significant amounts of reduced nitrogen to their immediate environments. The enhanced availability of reduced nitrogen in hydrothermal systems also has important implications for prebiotic metabolic pathways where nitrogen availability is critical to the production of amino acids and other nitrogenous compounds.

  16. Behavior of ionic conducting IPN actuators in simulated space conditions

    NASA Astrophysics Data System (ADS)

    Fannir, Adelyne; Plesse, Cédric; Nguyen, Giao T. M.; Laurent, Elisabeth; Cadiergues, Laurent; Vidal, Frédéric

    2016-04-01

    The presentation focuses on the performances of flexible all-polymer electroactive actuators under space-hazardous environmental factors in laboratory conditions. These bending actuators are based on high molecular weight nitrile butadiene rubber (NBR), poly(ethylene oxide) (PEO) derivative and poly(3,4-ethylenedioxithiophene) (PEDOT). The electroactive PEDOT is embedded within the PEO/NBR membrane which is subsequently swollen with an ionic liquid as electrolyte. Actuators have been submitted to thermal cycling test between -25 to 60°C under vacuum (2.4 10-8 mbar) and to ionizing Gamma radiations at a level of 210 rad/h during 100 h. Actuators have been characterized before and after space environmental condition ageing. In particular, the viscoelasticity properties and mechanical resistance of the materials have been determined by dynamic mechanical analysis and tensile tests. The evolution of the actuation properties as the strain and the output force have been characterized as well. The long-term vacuuming, the freezing temperature and the Gamma radiations do not affect significantly the thermomechanical properties of conducting IPNs actuators. Only a slight decrease on actuation performances has been observed.

  17. Simulation of coal ash deposition under pulverized coal combustion conditions

    SciTech Connect

    Yilmaz, S.; Cliffe, K.R.

    1994-12-31

    The deposition of coal ash onto the superheater tubes of a pulverized fuel fired boiler is simulated by injecting soda lime silica glass, SLSG, particles into hot combustion gases produced from the combustion of natural gas and by measuring the amount of deposit formed on a probe in a horizontally fired furnace. The effect of various parameters, including gas and probe surface temperatures, gas velocity, particle size and composition on deposit formation were investigated. The results showed that operating parameters, namely the gas temperature and probe surface temperature are of primary importance since deposition rates doubled over the range investigated. The deposition rate of 6 and 8 {mu}m particles was constant and considered to be controlled by their transport to the probe surface while that of larger particles showed an asymptotic behavior which suggested the deposition rate was controlled by the stickiness of the deposit surface on the probe. The addition of NaCl to SLSG particles increased deposition rates by approximately 100%, while addition of CACO{sub 3} showed no influence on the deposition rate of the SLSG particles. The addition of NaCl to CACO{sub 3} formed less deposit than CaCO{sub 3} particles on their own. Similarly, the deposition rate of SLSG and CaCO{sub 3} was lowered by addition of NaCl into it. This was probably caused by formation of some high melting point compounds between NaCl and CACO{sub 3}.

  18. Pressure Drop in Tortuosity/Kinking of the Internal Carotid Artery: Simulation and Clinical Investigation

    PubMed Central

    Wang, Lijun; Zhao, Feng; Wang, Daming; Hu, Shen; Liu, Jiachun; Zhou, Zhilun; Lu, Jun; Qi, Peng; Song, Shiying

    2016-01-01

    Background. Whether carotid tortuosity/kinking of the internal carotid artery leads to cerebral ischemia remains unclear. There is very little research about the hemodynamic variation induced by carotid tortuosity/kinking in the literature. The objective of this study was to research the blood pressure changes induced by carotid tortuosity/kinking. Methods. We first created a geometric model of carotid tortuosity/kinking. Based on hemodynamic boundary conditions, the hemodynamics of carotid tortuosity and kinking were studied via a finite element simulation. Then, an in vitro system was built to validate the numerical simulation results. The mean arterial pressure changes before and after carotid kinking were measured using pressure sensors in 12 patients with carotid kinking. Results. Numerical simulation revealed that the pressure drops increased with increases in the kinking angles. Clinical tests and in vitro experiments confirmed the numerical simulation results. Conclusions. Carotid kinking leads to blood pressure reduction. In certain conditions, kinking may affect the cerebral blood supply and be associated with cerebral ischemia. PMID:27195283

  19. Micromagnetic simulations with periodic boundary conditions: Hard-soft nanocomposites

    SciTech Connect

    Wysocki, Aleksander L.; Antropov, Vladimir P.

    2016-12-01

    Here, we developed a micromagnetic method for modeling magnetic systems with periodic boundary conditions along an arbitrary number of dimensions. The main feature is an adaptation of the Ewald summation technique for evaluation of long-range dipolar interactions. The method was applied to investigate the hysteresis process in hard-soft magnetic nanocomposites with various geometries. The dependence of the results on different micromagnetic parameters was studied. We found that for layered structures with an out-of-plane hard phase easy axis the hysteretic properties are very sensitive to the strength of the interlayer exchange coupling, as long as the spontaneous magnetization for the hard phase is significantly smaller than for the soft phase. The origin of this behavior was discussed. Additionally, we investigated the soft phase size optimizing the energy product of hard-soft nanocomposites.

  20. Micromagnetic simulations with periodic boundary conditions: Hard-soft nanocomposites

    NASA Astrophysics Data System (ADS)

    Wysocki, Aleksander L.; Antropov, Vladimir P.

    2017-04-01

    We developed a micromagnetic method for modeling magnetic systems with periodic boundary conditions along an arbitrary number of dimensions. The main feature is an adaptation of the Ewald summation technique for evaluation of long-range dipolar interactions. The method was applied to investigate the hysteresis process in hard-soft magnetic nanocomposites with various geometries. The dependence of the results on different micromagnetic parameters was studied. We found that for layered structures with an out-of-plane hard phase easy axis the hysteretic properties are very sensitive to the strength of the interlayer exchange coupling, as long as the spontaneous magnetization for the hard phase is significantly smaller than for the soft phase. The origin of this behavior was discussed. Additionally, we investigated the soft phase size optimizing the energy product of hard-soft nanocomposites.

  1. Micromagnetic simulations with periodic boundary conditions: Hard-soft nanocomposites

    DOE PAGES

    Wysocki, Aleksander L.; Antropov, Vladimir P.

    2016-12-01

    Here, we developed a micromagnetic method for modeling magnetic systems with periodic boundary conditions along an arbitrary number of dimensions. The main feature is an adaptation of the Ewald summation technique for evaluation of long-range dipolar interactions. The method was applied to investigate the hysteresis process in hard-soft magnetic nanocomposites with various geometries. The dependence of the results on different micromagnetic parameters was studied. We found that for layered structures with an out-of-plane hard phase easy axis the hysteretic properties are very sensitive to the strength of the interlayer exchange coupling, as long as the spontaneous magnetization for the hardmore » phase is significantly smaller than for the soft phase. The origin of this behavior was discussed. Additionally, we investigated the soft phase size optimizing the energy product of hard-soft nanocomposites.« less

  2. Some potentialities of living organisms under simulated Martian conditions.

    PubMed

    Lozina-Lozinsky, L K; Bychenkova, V N; Zaar, E I; Levin, V L; Rumyantseva, V M

    1971-01-01

    Temperature, humidity, pressure, composition of the atmosphere and radiation are the main factors conditioning life on the surface of Mars. When studying the Martian ecology, one must know the total effect of these factors. One may expect that, as a result of adaptation to low temperatures, there is a corresponding shift in the temperature optimum of enzymatic activity. Dryness is the main obstacle to active life. We suggest the presence of some soil moisture and water vapour. Moreover, there can be areas of permafrost. This minimum supply of water and periodic fluctuations of humidity may create conditions for the existence of drought-resistant organisms. Decreased atmospheric pressure alone does not affect micro-organisms, plants, protozoa and even insects. Ciliates reproduce in a flowing atmosphere of pure nitrogen containing 0.0002-0.0005% oxygen as an impurity. Protozoa may also develop in an atmosphere of 98-99% carbon dioxide mixed with 1% O2. Therefore, even traces of oxygen in the Martian atmosphere would be sufficient for aerobic unicellular organisms. Cells and organisms on earth have acquired various ways of protection from uv light, and therefore may increase their resistance further by adaptation or selection. The resistance of some organisms to ionizing radiation is high enough to enable them to endure hard ionizing radiation of the sun. Experiments with unicellular [correction of unicellar] organisms show that the effect of short wave uv radiation depends on the intensity of visible light, long-wave solar uv radiation, temperatures, cell repair processes, and the state of cell components, i.e. whether the cell was frozen, dried or hydrated.

  3. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... testing; clinical consultant. 493.1453 Section 493.1453 Public Health CENTERS FOR MEDICARE & MEDICAID... Condition: Laboratories performing high complexity testing; clinical consultant. The laboratory must have a clinical consultant who meets the requirements of § 493.1455 of this subpart and provides...

  4. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... complexity testing; clinical consultant. 493.1415 Section 493.1415 Public Health CENTERS FOR MEDICARE... § 493.1415 Condition: Laboratories performing moderate complexity testing; clinical consultant. The laboratory must have a clinical consultant who meets the qualification requirements of § 493.1417 of...

  5. Role of Boundary Conditions in Monte Carlo Simulation of MEMS Devices

    NASA Technical Reports Server (NTRS)

    Nance, Robert P.; Hash, David B.; Hassan, H. A.

    1997-01-01

    A study is made of the issues surrounding prediction of microchannel flows using the direct simulation Monte Carlo method. This investigation includes the introduction and use of new inflow and outflow boundary conditions suitable for subsonic flows. A series of test simulations for a moderate-size microchannel indicates that a high degree of grid under-resolution in the streamwise direction may be tolerated without loss of accuracy. In addition, the results demonstrate the importance of physically correct boundary conditions, as well as possibilities for reducing the time associated with the transient phase of a simulation. These results imply that simulations of longer ducts may be more feasible than previously envisioned.

  6. Postnatal development under conditions of simulated weightlessness and space flight

    NASA Technical Reports Server (NTRS)

    Walton, K.

    1998-01-01

    The adaptability of the developing nervous system to environmental influences and the mechanisms underlying this plasticity has recently become a subject of interest in space neuroscience. Ground studies on neonatal rats using the tail suspension model of weightlessness have shown that the force of gravity clearly influences the events underlying the postnatal development of motor function. These effects depend on the age of the animal, duration of the perturbation and the motor function studied. A nine-day flight study has shown that a dam and neonates can develop under conditions of space flight. The motor function of the flight animals after landing was consistent with that seen in the tail suspension studies, being marked by limb joint extension. However, there were expected differences due to: (1) the unloading of the vestibular system in flight, which did not occur in the ground-based experiments; (2) differences between flight and suspension durations; and (3) the inability to evaluate motor function during the flight. The next step is to conduct experiments in space with the flexibility and rigor that is now limited to ground studies: an opportunity offered by the International Space Station. Copyright 1998 Published by Elsevier Science B.V.

  7. Problem-Solving in the Pre-Clinical Curriculum: The Uses of Computer Simulations.

    ERIC Educational Resources Information Center

    Michael, Joel A.; Rovick, Allen A.

    1986-01-01

    Promotes the use of computer-based simulations in the pre-clinical medical curriculum as a means of providing students with opportunities for problem solving. Describes simple simulations of skeletal muscle loads, complex simulations of major organ systems and comprehensive simulation models of the entire human body. (TW)

  8. Development of Automatic Controller of Brain Temperature Based on the Conditions of Clinical Use

    NASA Astrophysics Data System (ADS)

    Utsuki, Tomohiko; Wakamatsu, Hidetoshi

    A new automatic controller of brain temperature was developed based on the inevitable conditions of its clinical use from the viewpoint of various kinds of feasibility, in particular, electric power consumption of less than 1,500W in ICU. The adaptive algorithm was employed to cope with individual time-varying characteristic change of patients. The controller under water-surface cooling hypothermia requires much power for the frequent regulation of the water temperature of cooling blankets. Thus, in this study, the power consumption of the controller was checked by several kinds of examinations involving the control simulation of brain temperature using a mannequin with thermal characteristics similar to that of adult patients. The required accuracy of therapeutic brain hypothermia, i.e. control deviation within ±0.1C was experimentally confirmed using “root mean square of the control error”, despite the present controller consumes less energy comparing with the one in the case of our conventional controller, where it can still keeps remaining power margin more than 300W even in the full operation. Thereby, the clinically required water temperature was also confirmed within the limit of power supply, thus its practical application is highly expected with less physical burden of medical staff inclusive of more usability and more medical cost performance.

  9. Visual-search observers for SPECT simulations with clinical backgrounds

    NASA Astrophysics Data System (ADS)

    Gifford, Howard C.

    2016-03-01

    The purpose of this work was to test the ability of visual-search (VS) model observers to predict the lesion- detection performance of human observers with hybrid SPECT images. These images consist of clinical back- grounds with simulated abnormalities. The application of existing scanning model observers to hybrid images is complicated by the need for extensive statistical information, whereas VS models based on separate search and analysis processes may operate with reduced knowledge. A localization ROC (LROC) study involved the detection and localization of solitary pulmonary nodules in Tc-99m lung images. The study was aimed at op- timizing the number of iterations and the postfiltering of four rescaled block-iterative reconstruction strategies. These strategies implemented different combinations of attenuation correction, scatter correction, and detector resolution correction. For a VS observer in this study, the search and analysis processes were guided by a single set of base morphological features derived from knowledge of the lesion profile. One base set used difference-of- Gaussian channels while a second base set implemented spatial derivatives in combination with the Burgess eye filter. A feature-adaptive VS observer selected features of interest for a given image set on the basis of training-set performance. A comparison of the feature-adaptive observer results against previously acquired human-observer data is presented.

  10. RANS simulation of cavitation and hull pressure fluctuation for marine propeller operating behind-hull condition

    NASA Astrophysics Data System (ADS)

    Paik, Kwang-Jun; Park, Hyung-Gil; Seo, Jongsoo

    2013-12-01

    Simulations of cavitation flow and hull pressure fluctuation for a marine propeller operating behind a hull using the unsteady Reynolds-Averaged Navier-Stokes equations (RANS) are presented. A full hull body submerged under the free surface is modeled in the computational domain to simulate directly the wake field of the ship at the propeller plane. Simulations are performed in design and ballast draught conditions to study the effect of cavitation number. And two propellers with slightly different geometry are simulated to validate the detectability of the numerical simulation. All simulations are performed using a commercial CFD software FLUENT. Cavitation patterns of the simulations show good agreement with the experimental results carried out in Samsung CAvitation Tunnel (SCAT). The simulation results for the hull pressure fluctuation induced by a propeller are also compared with the experimental results showing good agreement in the tendency and amplitude, especially, for the first blade frequency.

  11. Ophthalmology simulation for undergraduate and postgraduate clinical education

    PubMed Central

    Ting, Daniel Shu Wei; Sim, Shaun Sebastian Khung Peng; Yau, Christine Wen Leng; Rosman, Mohamad; Aw, Ai Tee; Yeo, Ian Yew San

    2016-01-01

    This is a review education paper on the current ophthalmology simulators utilized worldwide for undergraduate and postgraduate training. At present, various simulators such as the EYE Exam Simulator (Kyoto Kagaku Co. Ltd., Kyoto, Japan), Eyesi direct ophthalmoscope simulator (VRmagic, GmbH, Mannheim, Germany), Eyesi indirect ophthalmoscope simulator (VRmagic, GmbH, Mannheim, Germany) and Eyesi cataract simulators (VRmagic, GmbH, Mannheim, Germany). These simulators are thought to be able to reduce the initial learning curve for the ophthalmology training but further research will need to be conducted to assess the effectiveness of the simulation-assisted Ophthalmology training. Future research will be of great value to assess the medical students and residents' responses and performance regarding the usefulness of the individual eye simulator. PMID:27366698

  12. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 {times} 3.0 {times} 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models.

  13. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 [times] 3.0 [times] 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models.

  14. OVERALL MASS TRANSFER COEFFICIENT FOR POLLUTANT EMISSIONS FROM SMALL WATER POOLS UNDER SIMULATED INDOOR ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

    Small chamber tests were conducted to experimentally determine the overall mass transfer coefficient for pollutant emissions from still water under simulated indoor-residential or occupational-environmental conditions. Fourteen tests were conducted in small environmental chambers...

  15. Conditioning geostatistical simulations of a bedrock fluvial aquifer using single well pumping tests

    NASA Astrophysics Data System (ADS)

    Niazi, A.; Bentley, L. R.; Hayashi, M.

    2015-12-01

    Geostatistical simulation is a powerful tool to explore the uncertainty associated with heterogeneity in groundwater and reservoir studies. Nonetheless, conditioning simulations merely with lithological information does not utilize all of the available information and so some workers additionally condition simulations with flow data. In this study, we introduce an approach to condition geostatistical simulations of the Paskapoo Formation, which is a paleo-fluvial system consisting of sandstone channels embedded in mudstone. The conditioning data consist of two-hour single well pumping tests extracted from the public water well database in Alberta, Canada. In this approach, lithologic models of an entire watershed are simulated and conditioned with hard lithological data using transition probability geostatistics (TPROGS). Then, a segment of the simulation around a pumping well was used to populate a flow model (FEFLOW) with either sand or mudstone. The values of the hydraulic conductivity and specific storage of sand and mudstone were then adjusted to minimize the difference between simulated and actual pumping test data using the parameter estimation program PEST. If the simulated data do not adequately match the measured data, the lithologic model is updated by locally deforming the lithology distribution using the probability perturbation method (PPM) and the model parameters are again updated with PEST. This procedure is repeated until the simulated and measured data agree within a pre-determined tolerance. The procedure is repeated for each pumping well that has pumping test data. The method constrains the lithological simulations and provides estimates of hydraulic conductivity and specific storage that are consistent with the pumping test data. Eventually, the simulations will be combined in watershed scale groundwater models.

  16. Residents’ perceptions of simulation as a clinical learning approach

    PubMed Central

    Walsh, Catharine M.; Garg, Ankit; Ng, Stella L.; Goyal, Fenny; Grover, Samir C.

    2017-01-01

    Background Simulation is increasingly being integrated into medical education; however, there is little research into trainees’ perceptions of this learning modality. We elicited trainees’ perceptions of simulation-based learning, to inform how simulation is developed and applied to support training. Methods We conducted an instrumental qualitative case study entailing 36 semi-structured one-hour interviews with 12 residents enrolled in an introductory simulation-based course. Trainees were interviewed at three time points: pre-course, post-course, and 4–6 weeks later. Interview transcripts were analyzed using a qualitative descriptive analytic approach. Results Residents’ perceptions of simulation included: 1) simulation serves pragmatic purposes; 2) simulation provides a safe space; 3) simulation presents perils and pitfalls; and 4) optimal design for simulation: integration and tension. Key findings included residents’ markedly narrow perception of simulation’s capacity to support non-technical skills development or its use beyond introductory learning. Conclusion Trainees’ learning expectations of simulation were restricted. Educators should critically attend to the way they present simulation to learners as, based on theories of problem-framing, trainees’ a priori perceptions may delimit the focus of their learning experiences. If they view simulation as merely a replica of real cases for the purpose of practicing basic skills, they may fail to benefit from the full scope of learning opportunities afforded by simulation. PMID:28344719

  17. Simulations of Prebiotic Chemistry under Post-Impact Conditions on Titan

    PubMed Central

    Turse, Carol; Leitner, Johannes; Firneis, Maria; Schulze-Makuch, Dirk

    2013-01-01

    The problem of how life began can be considered as a matter of basic chemistry. How did the molecules of life arise from non-biological chemistry? Stanley Miller’s famous experiment in 1953, in which he produced amino acids under simulated early Earth conditions, was a huge leap forward in our understanding of this problem. Our research first simulated early Earth conditions based on Miller’s experiment and we then repeated the experiment using Titan post-impact conditions. We simulated conditions that could have existed on Titan after an asteroid strike. Specifically, we simulated conditions after a potential strike in the subpolar regions of Titan that exhibit vast methane-ethane lakes. If the asteroid or comet was of sufficient size, it would also puncture the icy crust and bring up some of the subsurface liquid ammonia-water mixture. Since, O’Brian, Lorenz and Lunine showed that a liquid water-ammonia body could exist between about 102–104 years on Titan after an asteroid impact we modified our experimental conditions to include an ammonia-water mixture in the reaction medium. Here we report on the resulting amino acids found using the Titan post-impact conditions in a classical Miller experimental reaction set-up and how they differ from the simulated early Earth conditions. PMID:25369885

  18. Simulations of Prebiotic Chemistry under Post-Impact Conditions on Titan.

    PubMed

    Turse, Carol; Leitner, Johannes; Firneis, Maria; Schulze-Makuch, Dirk

    2013-12-17

    The problem of how life began can be considered as a matter of basic chemistry. How did the molecules of life arise from non-biological chemistry? Stanley Miller's famous experiment in 1953, in which he produced amino acids under simulated early Earth conditions, was a huge leap forward in our understanding of this problem. Our research first simulated early Earth conditions based on Miller's experiment and we then repeated the experiment using Titan post-impact conditions. We simulated conditions that could have existed on Titan after an asteroid strike. Specifically, we simulated conditions after a potential strike in the subpolar regions of Titan that exhibit vast methane-ethane lakes. If the asteroid or comet was of sufficient size, it would also puncture the icy crust and bring up some of the subsurface liquid ammonia-water mixture. Since, O'Brian, Lorenz and Lunine showed that a liquid water-ammonia body could exist between about 102-104 years on Titan after an asteroid impact we modified our experimental conditions to include an ammonia-water mixture in the reaction medium. Here we report on the resulting amino acids found using the Titan post-impact conditions in a classical Miller experimental reaction set-up and how they differ from the simulated early Earth conditions.

  19. Retail Clinic Visits For Low-Acuity Conditions Increase Utilization And Spending.

    PubMed

    Ashwood, J Scott; Gaynor, Martin; Setodji, Claude M; Reid, Rachel O; Weber, Ellerie; Mehrotra, Ateev

    2016-03-01

    Retail clinics have been viewed by policy makers and insurers as a mechanism to decrease health care spending, by substituting less expensive clinic visits for more expensive emergency department or physician office visits. However, retail clinics may actually increase spending if they drive new health care utilization. To assess whether retail clinic visits represent new utilization or a substitute for more expensive care, we used insurance claims data from Aetna for the period 2010-12 to track utilization and spending for eleven low-acuity conditions. We found that 58 percent of retail clinic visits for low-acuity conditions represented new utilization and that retail clinic use was associated with a modest increase in spending, of $14 per person per year. These findings do not support the idea that retail clinics decrease health care spending.

  20. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.162-03 Approval of... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such...

  1. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.162-03 Approval of... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such...

  2. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.162-03 Approval of... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such...

  3. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.162-03 Approval of... initiative, the Administrator will approve a simulation of the environmental cell for air conditioning test... environmental cell test data for the range of vehicles to be covered by the simulation including items such...

  4. Fluidised Bed Microencapsulation of Ascorbic Acid: Effectiveness of Protection under Simulated Tropical Storage Conditions

    DTIC Science & Technology

    2012-01-01

    evidence of poor microencapsulation were terminated. Trials that resulted in microcapsule breakage did not proceed to the storage study. 2.3.1...UNCLASSIFIED Fluidised Bed Microencapsulation of Ascorbic Acid: Effectiveness of Protection under Simulated Tropical Storage Conditions...investigates the use of microencapsulation by fluidised bed coating for the protection of ascorbic acid during long-term storage under simulated

  5. Towards Direct Simulations of Counterflow Flames with Consistent Numerical Differential-Algebraic Boundary Conditions

    DTIC Science & Technology

    2015-05-18

    Towards direct simulations of counterflow flames with consistent numerical differential-algebraic boundary conditions The views, opinions and/or...Research Triangle Park, NC 27709-2211 counterflow laminar flame model REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR...simulations of counterflow flames with consistent numerical differential-algebraic boundary conditions Report Title A new approach for the

  6. Clinical simulation as a boundary object in design of health IT-systems.

    PubMed

    Rasmussen, Stine Loft; Jensen, Sanne; Lyng, Karen Marie

    2013-01-01

    Healthcare organizations are very complex, holding numerous stakeholders with various approaches and goals towards the design of health IT-systems. Some of these differences may be approached by applying the concept of boundary objects in a participatory IT-design process. Traditionally clinical simulation provides the opportunity to evaluate the design and the usage of clinical IT-systems without endangering the patients and interrupting clinical work. In this paper we present how clinical simulation additionally holds the potential to function as a boundary object in the design process. The case points out that clinical simulation provides an opportunity for discussions and mutual learning among the various stakeholders involved in design of standardized electronic clinical documentation templates. The paper presents and discusses the use of clinical simulation in the translation, transfer and transformation of knowledge between various stakeholders in a large healthcare organization.

  7. Application of a mechanobiological simulation technique to stents used clinically.

    PubMed

    Boyle, Colin J; Lennon, Alex B; Prendergast, Patrick J

    2013-03-15

    Many cardiovascular diseases are characterised by the restriction of blood flow through arteries. Stents can be expanded within arteries to remove such restrictions; however, tissue in-growth into the stent can lead to restenosis. In order to predict the long-term efficacy of stenting, a mechanobiological model of the arterial tissue reaction to stress is required. In this study, a computational model of arterial tissue response to stenting is applied to three clinically relevant stent designs. We ask the question whether such a mechanobiological model can differentiate between stents used clinically, and we compare these predictions to a purely mechanical analysis. In doing so, we are testing the hypothesis that a mechanobiological model of arterial tissue response to injury could predict the long-term outcomes of stent design. Finite element analysis of the expansion of three different stent types was performed in an idealised, 3D artery. Injury was calculated in the arterial tissue using a remaining-life damage mechanics approach. The inflammatory response to this initial injury was modelled using equations governing variables which represented tissue-degrading species and growth factors. Three levels of inflammation response were modelled to account for inter-patient variability. A lattice-based model of smooth muscle cell behaviour was implemented, treating cells as discrete agents governed by local rules. The simulations predicted differences between stent designs similar to those found in vivo. It showed that the volume of neointima produced could be quantified, providing a quantitative comparison of stents. In contrast, the differences between stents based on stress alone were highly dependent on the choice of comparison criteria. These results show that the choice of stress criteria for stent comparisons is critical. This study shows that mechanobiological modelling may provide a valuable tool in stent design, allowing predictions of their long

  8. Simulating Expert Clinical Comprehension: Adapting Latent Semantic Analysis to Accurately Extract Clinical Concepts from Psychiatric Narrative

    PubMed Central

    Cohen, Trevor; Blatter, Brett; Patel, Vimla

    2008-01-01

    Cognitive studies reveal that less-than-expert clinicians are less able to recognize meaningful patterns of data in clinical narratives. Accordingly, psychiatric residents early in training fail to attend to information that is relevant to diagnosis and the assessment of dangerousness. This manuscript presents cognitively motivated methodology for the simulation of expert ability to organize relevant findings supporting intermediate diagnostic hypotheses. Latent Semantic Analysis is used to generate a semantic space from which meaningful associations between psychiatric terms are derived. Diagnostically meaningful clusters are modeled as geometric structures within this space and compared to elements of psychiatric narrative text using semantic distance measures. A learning algorithm is defined that alters components of these geometric structures in response to labeled training data. Extraction and classification of relevant text segments is evaluated against expert annotation, with system-rater agreement approximating rater-rater agreement. A range of biomedical informatics applications for these methods are suggested. PMID:18455483

  9. Performance and Operating Characteristics of a Turbine Engine Propulsion Simulator at Simulated Flight Conditions

    DTIC Science & Technology

    1976-05-01

    Downstream Dump TDS Supply TDV TDH ’BV Turbine Drive Venturi Drive Manifold Bleed Manifold Turbine Bleed Venturi TDL Downstream Dump Fs...Propulsion simulator instrumentation. AEOC-TR-76-76 Sym Wall Static Pressure Dynamic Static Pressure Total Pressure Total Temperature Station

  10. Virtual Patient Simulations for Medical Education: Increasing Clinical Reasoning Skills through Deliberate Practice

    ERIC Educational Resources Information Center

    McCoy, Lise

    2014-01-01

    Virtual Patient Simulations (VPS) are web-based exercises involving simulated patients in virtual environments. This study investigates the utility of VPS for increasing medical student clinical reasoning skills, collaboration, and engagement. Many studies indicate that VPS provide medical students with essential practice in clinical decision…

  11. The Lived-Experience of Novice Nurse's Actualizing Clinical Reasoning in Academic Simulation

    ERIC Educational Resources Information Center

    Brinker, Mary Catherine

    2016-01-01

    The purpose of this existential-phenomenological study was to address the first-person perspective of what it is like to experience clinical reasoning during a simulation. It was not known how a novice nurse would describe the experience of actualizing clinical reasoning during the academic simulation experience. In order to maintain the…

  12. Developing Clinical Competency in Crisis Event Management: An Integrated Simulation Problem-Based Learning Activity

    ERIC Educational Resources Information Center

    Liaw, S. Y.; Chen, F. G.; Klainin, P.; Brammer, J.; O'Brien, A.; Samarasekera, D. D.

    2010-01-01

    This study aimed to evaluate the integration of a simulation based learning activity on nursing students' clinical crisis management performance in a problem-based learning (PBL) curriculum. It was hypothesized that the clinical performance of first year nursing students who participated in a simulated learning activity during the PBL session…

  13. A hybrid approach to achieving both marginal and conditional balances for stratification variables in sequential clinical trials.

    PubMed

    Lin, Yunzhi; Su, Zheng

    2013-01-01

    Various methods exist in the literature for achieving marginal balance for baseline stratification variables in sequential clinical trials. One major limitation with balancing on the margins of the stratification variables is that there is an efficiency loss when the primary analysis is stratified. To preserve the efficiency of a stratified analysis one recently proposed approach balances on the crossing of the stratification variables included in the analysis, which achieves conditional balance for the variables. A hybrid approach to achieving both marginal and conditional balances in sequential clinical trials is proposed, which is applicable to both continuous and categorical stratification variables. Numerical results based on extensive simulation studies and a real dataset show that the proposed approach outperforms the existing ones and is particularly useful when both additive and stratified models are planned for a trial.

  14. Challenges of clinical trial design when there is lack of clinical equipoise: use of a response-conditional crossover design.

    PubMed

    Deng, Chunqin; Hanna, Kim; Bril, Vera; Dalakas, Marinos C; Donofrio, Peter; van Doorn, Pieter A; Hartung, Hans-Peter; Merkies, Ingemar S J

    2012-02-01

    Clinical equipoise is widely accepted as the basis of ethics in clinical research and requires investigators to be uncertain of the relative therapeutic merits of trial comparators. When clinical equipoise is in question, innovative trial designs are needed to reduce ethical tension while satisfying regulators' requirements. We report a novel response-conditional crossover study design used in a Phase 3, randomized, double-blind, placebo-controlled clinical trial of intravenous 10% caprylate-chromatography purified immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy. During the initial 24-week period, patients crossed over to the alternative treatment at the first sign of deterioration or if they failed to improve or were unable to maintain improvement at any time after 6 weeks. This trial design addressed concerns about lack of equipoise raised by physicians interested in trial participation and proved acceptable to regulatory authorities. The trial design may be applicable to other studies where clinical equipoise is in question.

  15. Confirmation of uncontrolled flow dynamics in clinical simulated multi-infusion setups using absorption spectral photometry

    NASA Astrophysics Data System (ADS)

    Timmerman, Anna M.; Riphagen, Brechtje; Klaessens, John H.; Verdaasdonk, Rudolf M.

    2010-02-01

    Multi-infusion systems are used frequently at intensive care units to administer several liquid therapeutic agents to patients simultaneously. By passively combining the separate infusion lines in one central line, the number of punctures needed to access the patient's body, is reduced. So far, the mutual influence between the different infusion lines is unknown. Although the flow properties of single infusion systems have been investigated extensively, only a few research groups have investigated the flow properties of multi-infusion systems. We showed in a previous study that applying multi-infusion can lead to fluctuations in syringe pump infusions, resulting in uncontrolled and inaccurate drug administration. This study presents a performance analysis of multi-infusion systems as used in the Neonatology Intensive Care Unit. The dynamics between multiple infusion lines in multi-infusion systems were investigated by simulation experiments of clinical conditions. A newly developed real-time spectral-photometric method was used for the quantitative determination of concentration and outflow volume using a deconvolution method of absorption spectra of mixed fluids. The effects for common clinical interventions were studied in detail. Results showed mutual influence between the different infusion lines following these interventions. This mutual influence led to significant volume fluctuations up to 50%. These deviations could result in clinically dangerous situations. A complete analysis of the multiinfusion system characteristics is recommended in further research to estimate both the presence and severity of potential risks in clinical use.

  16. Dynamics Modeling and Simulation of Large Transport Airplanes in Upset Conditions

    NASA Technical Reports Server (NTRS)

    Foster, John V.; Cunningham, Kevin; Fremaux, Charles M.; Shah, Gautam H.; Stewart, Eric C.; Rivers, Robert A.; Wilborn, James E.; Gato, William

    2005-01-01

    As part of NASA's Aviation Safety and Security Program, research has been in progress to develop aerodynamic modeling methods for simulations that accurately predict the flight dynamics characteristics of large transport airplanes in upset conditions. The motivation for this research stems from the recognition that simulation is a vital tool for addressing loss-of-control accidents, including applications to pilot training, accident reconstruction, and advanced control system analysis. The ultimate goal of this effort is to contribute to the reduction of the fatal accident rate due to loss-of-control. Research activities have involved accident analyses, wind tunnel testing, and piloted simulation. Results have shown that significant improvements in simulation fidelity for upset conditions, compared to current training simulations, can be achieved using state-of-the-art wind tunnel testing and aerodynamic modeling methods. This paper provides a summary of research completed to date and includes discussion on key technical results, lessons learned, and future research needs.

  17. The study of minerals under simulated planetary conditions: Experiments of hydrated sulphates at environmental conditions of martian surface

    NASA Astrophysics Data System (ADS)

    Prieto-Ballesteros, O.; Mateo-Martí, E.; Fernández-Remolar, D.

    2007-08-01

    Minerals on planetary surfaces are usually identified comparing remote infrared spectral data to laboratory mineral databases obtained under terrestrial conditions. However, environmental conditions at other planetary surfaces could produce alterations on the standard mineral spectra. Spectroscopic signals of hydrated magnesium, calcium and hydroxlated iron sulphates have been recently detected on surface of Mars. Some experiments using environmental conditions at the martian surface (temperature and pressure ranges; atmospheric composition, including water vapor content; and ultraviolet radiation) of different sulphates have been performed in order to both, constrain the stability of the hydrated phases and detect any possible modification in their spectra. Experiments have been done in a simulation chamber located in Centro de Astrobiologia, Madrid. The equipment has been developed for a wide range of simulation conditions, including a range of irradiation sources, and the implementation of analytical techniques, including IR and UV spectroscopy and mass spectrometry. The equipment consists of a main vacuum chamber with dimensions of 50 cm long x 40 cm diameter, a second internal chamber connected by differential pumping with the main one, and a third side chamber for the gases analysis using a mass spectrometer. Chambers pressures are monitorized by different pirani-penning gauges. A liquid nitrogen cooling system is connected to the sample holder, and a gas system allows the mixing of gases and water.

  18. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1987-01-01

    Laboratory measurements were conducted to evaluate properties of atmospheric gases under simulated conditions for the outer planets. A significant addition to this effort was the capability to make such measurements at millimeter wavelengths. Measurements should soon be completed on the millimeter wave absorption from ammonia under Jovian conditions. Also studied will be the feasibility of measuring the microwave and millimeter wave properties of phosphine (PH3) under simulated Jovian conditions. Further analysis and application of the laboratory results to microwave and millimeter wave absorption data for the outer planet, such as Voyager Radio Occultation experiments, will be pursued.

  19. Performance evaluation of automated fingerprint identification systems for specific conditions observed in casework using simulated fingermarks.

    PubMed

    de Jongh, Arent; Rodriguez, Crystal M

    2012-07-01

    Few studies have been reported on the performance evaluation of automated fingerprint identification systems (AFIS) for fingermark-to-fingerprint comparisons. This paper aims to illustrate to fingerprint examiners the relevance of evaluating the AFIS performance under specific conditions by carrying out five types of performance tests. The conditions addressed are the number of minutiae assigned to a fingermark, manual and automatic assignment of the minutiae, the finger region from which the fingermark originates, the degree of distortion in the fingermark, and the difference in orientation between fingermarks and fingerprints. In these tests, the magnitude of the influence for each condition was quantified. The comparisons were performed using a research AFIS technology with simulated fingermarks. Simulated fingermarks provide a practical way to create fingermarks for specific conditions in large quantities. The results showed that each condition influences the performance significantly, emphasizing the relevance of developing, and applying performance tests for specific conditions.

  20. Growth and photosynthesis of Japanese flowering cherry under simulated microgravity conditions

    NASA Technical Reports Server (NTRS)

    Sugano, Mami; Ino, Yoshio; Nakamura, Teruko

    2002-01-01

    The photosynthetic rate, the leaf characteristics related to photosynthesis, such as the chlorophyll content, chlorophyll a/b ratio and density of the stomata, the leaf area and the dry weight in seedlings of Japanese flowering cherry grown under normal gravity and simulated microgravity conditions were examined. No significant differences were found in the photosynthetic rates between the two conditions. Moreover, leaf characteristics such as the chlorophyll content, chlorophyll a/b ratio and density of the stomata in the seedlings grown under the simulated microgravity condition were not affected. However, the photosynthetic product of the whole seedling under the simulated microgravity condition increased compared with the control due to its leaf area increase. The results suggest that dynamic gravitational stimulus controls the partitioning of the products of photosynthesis.

  1. Growth and photosynthesis of Japanese flowering cherry under simulated microgravity conditions.

    PubMed

    Sugano, Mami; Ino, Yoshio; Nakamura, Teruko

    2002-12-01

    The photosynthetic rate, the leaf characteristics related to photosynthesis, such as the chlorophyll content, chlorophyll a/b ratio and density of the stomata, the leaf area and the dry weight in seedlings of Japanese flowering cherry grown under normal gravity and simulated microgravity conditions were examined. No significant differences were found in the photosynthetic rates between the two conditions. Moreover, leaf characteristics such as the chlorophyll content, chlorophyll a/b ratio and density of the stomata in the seedlings grown under the simulated microgravity condition were not affected. However, the photosynthetic product of the whole seedling under the simulated microgravity condition increased compared with the control due to its leaf area increase. The results suggest that dynamic gravitational stimulus controls the partitioning of the products of photosynthesis.

  2. Design, simulation and conditioning of the fundamental power couplers for BNL SRF gun

    SciTech Connect

    Xu W.; Altinbas, Z.; Belomestnykh, S.; Ben-Zvi, I. et al

    2012-05-20

    The 704 MHz SRF gun for the BNL Energy Recovery Linac (ERL) prototype uses two fundamental power couplers (FPCs) to deliver up to 1 MW of CW RF power to the half-cell cavity. To prepare the couplers for high-power RF service and process multipacting, the FPCs should be conditioned prior to installation into the gun cryomodule. A room-temperature test stand was configured for conditioning FPCs in full reflection regime with varied phase of the reflecting wave. The FPCs have been conditioned up to 250 kW in pulse mode and 125 kW in CW mode. The multipacting simulations were carried out with Track3P code developed at SLAC. The simulations matched the experimental results very well. This paper presents the FPC RF and thermal design, multipacting simulations and conditioning of the BNL gun FPCs.

  3. Impact of Simulation and Clinical Experience on Self-efficacy in Nursing Students: Intervention Study.

    PubMed

    Kimhi, Einat; Reishtein, Judith L; Cohen, Miri; Friger, Michael; Hurvitz, Nancy; Avraham, Rinat

    2016-01-01

    This study compared the effect of simulation and clinical experience timing on self-confidence/self-efficacy for the nursing process. Using a randomized, double-crossover design, self-efficacy was measured 3 times. Although self-efficacy was significantly higher at time 1 for students who had clinical experience, there was no difference between the groups at the end of the course (time 2). Thus, simulation increased self-confidence/self-efficacy equivalently if placed either before or after clinical experience.

  4. Eta model simulations using two radiation schemes in clear-sky conditions

    NASA Astrophysics Data System (ADS)

    de Andrade Campos, Diêgo; Chou, Sin Chan; Spyrou, Christos; Chagas, Júlio Cesar Santos; Bottino, Marcus Jorge

    2017-01-01

    This work evaluates the performance of two radiation parameterization schemes in 30-day clear-sky runs of the Eta model over a region in Southeast Brazil. Two versions of the Eta model are compared: a version using the radiation scheme developed by the Geophysical Fluid Dynamics Laboratory (GFDL) and a recently developed version using the Rapid Radiative Transfer Model for GCM (RRTMG). These simulations are compared against CMSAF satellite data and surface station data. The simulation using RRTMG produced downward surface shortwave radiation fluxes closer to observations and reduced the systematic positive bias of the Eta simulation using the GFDL scheme. The 2-m temperature negative bias found in the Eta-GFDL simulations is reduced in the Eta-RRTMG simulations, which results from a larger net total radiation in the Eta-RRTMG simulations. The new version has better accuracy than the Eta using the GFDL scheme for most of the evaluated variables, particularly for clear-sky conditions.

  5. A dual-pressure boundary condition for use in simulations of bifurcating conduits.

    PubMed

    Gin, Ron; Straatman, Anthony G; Steinman, David A

    2002-10-01

    A dual-pressure boundary condition has been developed for computational modelling of bifurcating conduits. The condition involves the imposition of a constant pressure on one branch while adjusting iteratively the pressure on the other branch until the desired flow division is obtained. The dual-pressure condition eliminates the need for specifying fully-developed flow conditions, which thereby enables significant reduction of the outlet branch lengths. The dual-pressure condition is suitable for both steady and time-periodic simulations of laminar or turbulent flows.

  6. Integrated Clinical Training for Space Flight Using a High-Fidelity Patient Simulator in a Simulated Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Hurst, Victor; Doerr, Harold K.; Polk, J. D.; Schmid, Josef; Parazynksi, Scott; Kelly, Scott

    2007-01-01

    This viewgraph presentation reviews the use of telemedicine in a simulated microgravity environment using a patient simulator. For decades, telemedicine techniques have been used in terrestrial environments by many cohorts with varied clinical experience. The success of these techniques has been recently expanded to include microgravity environments aboard the International Space Station (ISS). In order to investigate how an astronaut crew medical officer will execute medical tasks in a microgravity environment, while being remotely guided by a flight surgeon, the Medical Operation Support Team (MOST) used the simulated microgravity environment provided aboard DC-9 aircraft teams of crew medical officers, and remote flight surgeons performed several tasks on a patient simulator.

  7. Feasibility of Augmented Reality in Clinical Simulations: Using Google Glass With Manikins

    PubMed Central

    2016-01-01

    Background Studies show that students who use fidelity-based simulation technology perform better and have higher retention rates than peers who learn in traditional paper-based training. Augmented reality is increasingly being used as a teaching and learning tool in a continual effort to make simulations more realistic for students. Objective The aim of this project was to assess the feasibility and acceptability of using augmented reality via Google Glass during clinical simulation scenarios for training health science students. Methods Students performed a clinical simulation while watching a video through Google Glass of a patient actor simulating respiratory distress. Following participation in the scenarios students completed two surveys and were questioned if they would recommend continued use of this technology in clinical simulation experiences. Results We were able to have students watch a video in their field of vision of a patient who mimicked the simulated manikin. Students were overall positive about the implications for being able to view a patient during the simulations, and most students recommended using the technology in the future. Overall, students reported perceived realism with augmented reality using Google Glass. However, there were technical and usability challenges with the device. Conclusions As newer portable and consumer-focused technologies become available, augmented reality is increasingly being used as a teaching and learning tool to make clinical simulations more realistic for health science students. We found Google Glass feasible and acceptable as a tool for augmented reality in clinical simulations. PMID:27731862

  8. Simulation Study of Flap Effects on a Commercial Transport Airplane in Upset Conditions

    NASA Technical Reports Server (NTRS)

    Cunningham, Kevin; Foster, John V.; Shah, Gautam H.; Stewart, Eric C.; Ventura, Robin N.; Rivers, Robert A.; Wilborn, James E.; Gato, William

    2005-01-01

    As part of NASA's Aviation Safety and Security Program, a simulation study of a twinjet transport airplane crew training simulation was conducted to address fidelity for upset or loss of control conditions and to study the effect of flap configuration in those regimes. Piloted and desktop simulations were used to compare the baseline crew training simulation model with an enhanced aerodynamic model that was developed for high-angle-of-attack conditions. These studies were conducted with various flap configurations and addressed the approach-to-stall, stall, and post-stall flight regimes. The enhanced simulation model showed that flap configuration had a significant effect on the character of departures that occurred during post-stall flight. Preliminary comparisons with flight test data indicate that the enhanced model is a significant improvement over the baseline. Some of the unrepresentative characteristics that are predicted by the baseline crew training simulation for flight in the post-stall regime have been identified. This paper presents preliminary results of this simulation study and discusses key issues regarding predicted flight dynamics characteristics during extreme upset and loss-of-control flight conditions with different flap configurations.

  9. The International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of xenocorneal transplantation.

    PubMed

    Kim, Mee Kum; Choi, Hyuk Jin; Kwon, Ivo; Pierson, Richard N; Cooper, David K C; Soulillou, Jean-Paul; O'Connell, Philip J; Vabres, Bertrand; Maeda, Naoyuki; Hara, Hidetaka; Scobie, Linda; Gianello, Pierre; Takeuchi, Yasuhiro; Yamada, Kazuhiko; Hwang, Eung-Soo; Kim, Sang Joon; Park, Chung-Gyu

    2014-01-01

    To develop an international consensus regarding the appropriate conditions for undertaking clinical trials in xenocorneal transplantation, here we review specific ethical, logistical, scientific, and regulatory issues regarding xenocorneal transplantation, and propose guidelines for conduct of clinical xenocorneal transplantation trials. These proposed guidelines are modeled on the published consensus statement of the International Xenotransplantation Association regarding recommended guidelines for conduct of clinical islet xenotransplantation. It is expected that this initial consensus statement will be revised over time in response to scientific advances in the field, and changes in the regulatory framework based on accumulating clinical experience.

  10. In Silico Simulation of a Clinical Trial Concerning Tumour Response to Radiotherapy

    SciTech Connect

    Dionysiou, Dimitra D.; Stamatakos, Georgios S.; Athanaileas, Theodoras E.; Merrychtas, Andreas; Kaklamani, Dimitra; Varvarigou, Theodora; Uzunoglu, Nikolaos

    2008-11-06

    The aim of this paper is to demonstrate how multilevel tumour growth and response to therapeutic treatment models can be used in order to simulate clinical trials, with the long-term intention of both better designing clinical studies and understanding their outcome based on basic biological science. For this purpose, an already developed computer simulation model of glioblastoma multiforme response to radiotherapy has been used and a clinical study concerning glioblastoma multiforme response to radiotherapy has been simulated. In order to facilitate the simulation of such virtual trials, a toolkit enabling the user-friendly execution of the simulations on grid infrastructures has been designed and developed. The results of the conducted virtual trial are in agreement with the outcome of the real clinical study.

  11. In Silico Simulation of a Clinical Trial Concerning Tumour Response to Radiotherapy

    NASA Astrophysics Data System (ADS)

    Dionysiou, Dimitra D.; Stamatakos, Georgios S.; Athanaileas, Theodoras E.; Merrychtas, Andreas; Kaklamani, Dimitra; Varvarigou, Theodora; Uzunoglu, Nikolaos

    2008-11-01

    The aim of this paper is to demonstrate how multilevel tumour growth and response to therapeutic treatment models can be used in order to simulate clinical trials, with the long-term intention of both better designing clinical studies and understanding their outcome based on basic biological science. For this purpose, an already developed computer simulation model of glioblastoma multiforme response to radiotherapy has been used and a clinical study concerning glioblastoma multiforme response to radiotherapy has been simulated. In order to facilitate the simulation of such virtual trials, a toolkit enabling the user-friendly execution of the simulations on grid infrastructures has been designed and developed. The results of the conducted virtual trial are in agreement with the outcome of the real clinical study.

  12. Simulation research of the tire Basic Relaxation Model in conditions of the wheel cornering angle oscillations

    NASA Astrophysics Data System (ADS)

    Luty, W.

    2016-09-01

    - A description of the tire Basic Relaxation Model (BRM) is presented in this paper. Simulation research of the tire BRM model in conditions of oscillatory changes of the wheel cornering angle were performed. During the simulation tests the courses of changes in the value of lateral reaction force, transmitted by the wheel, as a response to the sinusoidal changes in the value of the wheel cornering angle have been presented. There have been compared the simulation results obtained for the model of tire-road interaction in two modes: including and not including the BRM. The simulation results allowed to verify prepared BRM and also to determine the influence of the tire relaxation process on the tire behavior in conditions of dynamic changes of the wheel cornering angle.

  13. Simulating the forecasting of meteorological and oceanic conditions as a part of the planning cycle in simulated command and control

    SciTech Connect

    Hummel, J.R.

    1998-07-01

    Weather can be a decisive factor in military operations. Numerous examples can be found in history when weather conditions played a critical role in determining the outcome of a battle. The impact of weather must, therefore, be considered in the planning of missions as well as in its execution. For example, in planning air missions, the ewather conditions during all phases of the mission (launch, over target, and recovery) need to be considered including weather factors during the real world planning process is done as a normal part of the situations awareness process. Including weather factors in simulated planning processes, should, and can be done as a normal part. In this Paper, the authors discuss how the forecasting of meteorological and oceanic can be incorporated into the planning process of analytical simulations.

  14. Assessment of Innovative Emergency Department Information Displays in a Clinical Simulation Center

    PubMed Central

    McGeorge, Nicolette; Hegde, Sudeep; Berg, Rebecca L.; Guarrera-Schick, Theresa K.; LaVergne, David T.; Casucci, Sabrina N.; Hettinger, A. Zachary; Clark, Lindsey N.; Lin, Li; Fairbanks, Rollin J.; Benda, Natalie C.; Sun, Longsheng; Wears, Robert L.; Perry, Shawna; Bisantz, Ann

    2016-01-01

    The objective of this work was to assess the functional utility of new display concepts for an emergency department information system created using cognitive systems engineering methods, by comparing them to similar displays currently in use. The display concepts were compared to standard displays in a clinical simulation study during which nurse-physician teams performed simulated emergency department tasks. Questionnaires were used to assess the cognitive support provided by the displays, participants’ level of situation awareness, and participants’ workload during the simulated tasks. Participants rated the new displays significantly higher than the control displays in terms of cognitive support. There was no significant difference in workload scores between the display conditions. There was no main effect of display type on situation awareness, but there was a significant interaction; participants using the new displays showed improved situation awareness from the middle to the end of the session. This study demonstrates that cognitive systems engineering methods can be used to create innovative displays that better support emergency medicine tasks, without increasing workload, compared to more standard displays. These methods provide a means to develop emergency department information systems—and more broadly, health information technology—that better support the cognitive needs of healthcare providers. PMID:27974881

  15. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1986-01-01

    After long arduous work with the simulator, measurements of the refractivity and absorptivity of nitrogen under conditions similar to those for Titan were completed. The most significant measurements, however, were those of the microwave absorption from gaseous ammonia under simulated conditions for the Jovian atmospheres over wavelengths from 1.3 to 22 cm. The results of these measurements are critical in that they confirm the theoretical calculation of the ammonia opacity using the Ben-Reuven lineshape. The application of both these results, and results obtained previously, to planetary observations at microwave frequencies were especially rewarding. Applications of the results for ammonia to radio astronomical observations of Jupiter in the 1.3 to 20 cm wavelength range and the application of results for gaseous H2SO4 under simulated Venus conditions are discussed.

  16. The influence of simulator input conditions on the wear of total knee replacements: An experimental and computational study

    PubMed Central

    Brockett, Claire L; Abdelgaied, Abdellatif; Haythornthwaite, Tony; Hardaker, Catherine; Fisher, John; Jennings, Louise M

    2016-01-01

    Advancements in knee replacement design, material and sterilisation processes have provided improved clinical results. However, surface wear of the polyethylene leading to osteolysis is still considered the longer-term risk factor. Experimental wear simulation is an established method for evaluating the wear performance of total joint replacements. The aim of this study was to investigate the influence of simulation input conditions, specifically input kinematic magnitudes, waveforms and directions of motion and position of the femoral centre of rotation, on the wear performance of a fixed-bearing total knee replacement through a combined experimental and computational approach. Studies were completed using conventional and moderately cross-linked polyethylene to determine whether the influence of these simulation input conditions varied with material. The position of the femoral centre of rotation and the input kinematics were shown to have a significant influence on the wear rates. Similar trends were shown for both the conventional and moderately cross-linked polyethylene materials, although lower wear rates were found for the moderately cross-linked polyethylene due to the higher level of cross-linking. The most important factor influencing the wear was the position of the relative contact point at the femoral component and tibial insert interface. This was dependent on the combination of input displacement magnitudes, waveforms, direction of motion and femoral centre of rotation. This study provides further evidence that in order to study variables such as design and material in total knee replacement, it is important to carefully control knee simulation conditions. This can be more effectively achieved through the use of displacement control simulation. PMID:27160561

  17. Perfectly Matched Layers versus discrete transparent boundary conditions in quantum device simulations

    SciTech Connect

    Mennemann, Jan-Frederik Jüngel, Ansgar

    2014-10-15

    Discrete transparent boundary conditions (DTBC) and the Perfectly Matched Layers (PML) method for the realization of open boundary conditions in quantum device simulations are compared, based on the stationary and time-dependent Schrödinger equation. The comparison includes scattering state, wave packet, and transient scattering state simulations in one and two space dimensions. The Schrödinger equation is discretized by a second-order Crank–Nicolson method in case of DTBC. For the discretization with PML, symmetric second-, fourth-, and sixth-order spatial approximations as well as Crank–Nicolson and classical Runge–Kutta time-integration methods are employed. In two space dimensions, a ring-shaped quantum waveguide device is simulated in the stationary and transient regime. As an application, a simulation of the Aharonov–Bohm effect in this device is performed, showing the excitation of bound states localized in the ring region. The numerical experiments show that the results obtained from PML are comparable to those obtained using DTBC, while keeping the high numerical efficiency and flexibility as well as the ease of implementation of the former method. -- Highlights: •In-depth comparison between discrete transparent boundary conditions (DTBC) and PML. •First 2-D transient scattering state simulations using DTBC. •First 2-D transient scattering state simulations of the Aharonov–Bohm effect.

  18. Conditions at the downstream boundary for simulations of viscous incompressible flow

    NASA Technical Reports Server (NTRS)

    Hagstrom, Thomas

    1990-01-01

    The proper specification of boundary conditions at artificial boundaries for the simulation of time-dependent fluid flows has long been a matter of controversy. A general theory of asymptotic boundary conditions for dissipative waves is applied to the design of simple, accurate conditions at downstream boundary for incompressible flows. For Reynolds numbers far enough below the critical value for linear stability, a scaling is introduced which greatly simplifies the construction of the asymptotic conditions. Numerical experiments with the nonlinear dynamics of vortical disturbances to plane Poiseuille flow are presented which illustrate the accuracy of our approach. The consequences of directly applying the scalings to the equations are also considered.

  19. New Automotive Air Conditioning System Simulation Tool Developed in MATLAB/Simulink

    SciTech Connect

    Kiss, T.; Chaney, L.; Meyer, J.

    2013-07-01

    Further improvements in vehicle fuel efficiency require accurate evaluation of the vehicle's transient total power requirement. When operated, the air conditioning (A/C) system is the largest auxiliary load on a vehicle; therefore, accurate evaluation of the load it places on the vehicle's engine and/or energy storage system is especially important. Vehicle simulation software, such as 'Autonomie,' has been used by OEMs to evaluate vehicles' energy performance. A transient A/C simulation tool incorporated into vehicle simulation models would also provide a tool for developing more efficient A/C systems through a thorough consideration of the transient A/C system performance. The dynamic system simulation software Matlab/Simulink was used to develop new and more efficient vehicle energy system controls. The various modeling methods used for the new simulation tool are described in detail. Comparison with measured data is provided to demonstrate the validity of the model.

  20. Instrumentation for Ground-Based Testing in Simulated Space and Planetary Conditions

    NASA Astrophysics Data System (ADS)

    Kleiman, Jacob; Horodetsky, Sergey; Issoupov, Vitali

    This paper is an overview of instrumentation developed and created by ITL Inc. for simulated testing and performance evaluation of spacecraft materials, structures, mechanisms, assemblies and components in different space and planetary environments. The LEO Space Environment Simulator allows simulation of the synergistic effect of ultra-high vacuum conditions, 5 eV neutral atomic oxygen beams, Vacuum-Ultraviolet (VUV) and Near-Ultraviolet (NUV) radiation, and temperature conditions. The simulated space environmental conditions can be controlled in-situ using a quadruple mass-spectrometer, Time-of-Flight technique, as well as Quartz Crystal Microbalance sensors. The new NUV System is capable of delivering an NUV power intensity of up to 10 Equivalent Suns. The design of the system uses horizontal orientation of the 5 kW Mercury lamp, focusing of NUV radiation is achieved due to a parabolic reflector. To address the Lunar/Martian surface environments, the Planetary Environmental Simulator/Test Facility has been developed and built to allow for physical evaluation of the effects of the Lunar/Martian dust environments in conjunction with other factors (ultra-high vacuum or planetary atmospheric conditions, VUV/NUV radiation, thermal cycling, and darkness). The ASTM E 595/ASTM E 1559 Outgassing Test Facility provides the means for the outgassing test of materials with the objective to select materials with low outgassing properties for spacecraft use and allows to determine the following outgassing parameters: Total Mass Loss, Collected Volatile Condensable Materials, and Water Vapor Regained.

  1. Precipitation-Runoff Simulations of Current and Natural Streamflow Conditions in the Methow River Basin, Washington

    USGS Publications Warehouse

    Ely, D. Matthew

    2003-01-01

    Management of the water resources of the Methow River Basin is changing in response to the listing of three species of fish under the Endangered Species Act and the Washington State-legislated watershed-planning process. This report describes the construction and calibration of an enhanced precipitation-runoff model for the Methow River Basin and evaluates the model as a predictive tool for assessing the current and natural streamflow conditions. This study builds upon a previous precipitation-runoff model for the Methow River Basin and validates the current model using a new, more extensive streamflow data network. The major enhancement was the simulation of current flow conditions with the addition of irrigation diversions, returns, and application. The Geographic Information System Weasel characterized the physical properties of the basin and the Modular Modeling System, using the Precipitation-Runoff Modeling System, simulated the hydrologic flow. Streamflow was simulated for water years 1992-2001 to calibrate the model to measured streamflows. A sensitivity analysis was completed using nonlinear regression to determine hydrologic parameters pertinent to the modeling results. Simulated and measured streamflow generally showed close agreement, especially during spring runoff from snowmelt. Low-flow or baseflow periods, most restrictive to fish habitation, were simulated reasonably well yet possessed the most uncertainty. Simulations of annual mean streamflow as a percentage of measured annual mean streamflow for the 10-year calibration period at six of the seven streamflow-gaging stations ranged from -35.2 to +26.2 percent, with 65 percent of the simulated values within 15 percent. One station was intentionally calibrated to over-simulate discharge (simulated discharge greater than measured discharge) in order to compensate for observed channel losses not simulated by the model. Simulation of water years 1960-2001 demonstrated great variability in monthly

  2. Protein patterns of black fungi under simulated Mars-like conditions.

    PubMed

    Zakharova, Kristina; Marzban, Gorji; de Vera, Jean-Pierre; Lorek, Andreas; Sterflinger, Katja

    2014-05-29

    Two species of microcolonial fungi - Cryomyces antarcticus and Knufia perforans - and a species of black yeasts-Exophiala jeanselmei - were exposed to thermo-physical Mars-like conditions in the simulation chamber of the German Aerospace Center. In this study the alterations at the protein expression level from various fungi species under Mars-like conditions were analyzed for the first time using 2D gel electrophoresis. Despite of the expectations, the fungi did not express any additional proteins under Mars simulation that could be interpreted as stress induced HSPs. However, up-regulation of some proteins and significant decreasing of protein number were detected within the first 24 hours of the treatment. After 4 and 7 days of the experiment protein spot number was increased again and the protein patterns resemble the protein patterns of biomass from normal conditions. It indicates the recovery of the metabolic activity under Martian environmental conditions after one week of exposure.

  3. Experiments and simulations of Richtmyer-Meshkov Instability with measured,volumetric initial conditions

    NASA Astrophysics Data System (ADS)

    Sewell, Everest; Ferguson, Kevin; Jacobs, Jeffrey; Greenough, Jeff; Krivets, Vitaliy

    2016-11-01

    We describe experiments of single-shock Richtmyer-Meskhov Instability (RMI) performed on the shock tube apparatus at the University of Arizona in which the initial conditions are volumetrically imaged prior to shock wave arrival. Initial perturbations play a major role in the evolution of RMI, and previous experimental efforts only capture a single plane of the initial condition. The method presented uses a rastered laser sheet to capture additional images throughout the depth of the initial condition immediately before the shock arrival time. These images are then used to reconstruct a volumetric approximation of the experimental perturbation. Analysis of the initial perturbations is performed, and then used as initial conditions in simulations using the hydrodynamics code ARES, developed at Lawrence Livermore National Laboratory (LLNL). Experiments are presented and comparisons are made with simulation results.

  4. Protein patterns of black fungi under simulated Mars-like conditions

    PubMed Central

    Zakharova, Kristina; Marzban, Gorji; de Vera, Jean-Pierre; Lorek, Andreas; Sterflinger, Katja

    2014-01-01

    Two species of microcolonial fungi – Cryomyces antarcticus and Knufia perforans - and a species of black yeasts–Exophiala jeanselmei - were exposed to thermo-physical Mars-like conditions in the simulation chamber of the German Aerospace Center. In this study the alterations at the protein expression level from various fungi species under Mars-like conditions were analyzed for the first time using 2D gel electrophoresis. Despite of the expectations, the fungi did not express any additional proteins under Mars simulation that could be interpreted as stress induced HSPs. However, up-regulation of some proteins and significant decreasing of protein number were detected within the first 24 hours of the treatment. After 4 and 7 days of the experiment protein spot number was increased again and the protein patterns resemble the protein patterns of biomass from normal conditions. It indicates the recovery of the metabolic activity under Martian environmental conditions after one week of exposure. PMID:24870977

  5. Simulating thermal boundary conditions of spin-lattice models with weighted averages

    NASA Astrophysics Data System (ADS)

    Wang, Wenlong

    2016-07-01

    Thermal boundary conditions have played an increasingly important role in revealing the nature of short-range spin glasses and is likely to be relevant also for other disordered systems. Diffusion method initializing each replica with a random boundary condition at the infinite temperature using population annealing has been used in recent large-scale simulations. However, the efficiency of this method can be greatly suppressed because of temperature chaos. For example, most samples have some boundary conditions that are completely eliminated from the population in the process of annealing at low temperatures. In this work, I study a weighted average method to solve this problem by simulating each boundary conditions separately and collect data using weighted averages. The efficiency of the two methods is studied using both population annealing and parallel tempering, showing that the weighted average method is more efficient and accurate.

  6. Exhaust emission survey of an F100 afterburning turbofan engine at simulated altitude flight conditions

    NASA Technical Reports Server (NTRS)

    Moss, J. E.; Cullom, R. R.

    1981-01-01

    Emissions of carbon monoxide, total oxides of nitrogen, unburned hydrocarbons, and carbon dioxide from an F100, afterburning, two spool turbofan engine at simulated flight conditions are reported. For each flight condition emission measurements were made for two or three power levels from intermediate power (nonafterburning) through maximum afterburning. The data showed that emissions vary with flight speed, altitude, power level, and radial position across the nozzle. Carbon monoxide emissions were low for intermediate power (nonafterburning) and partial afterburning, but regions of high carbon monoxide were present downstream of the flame holder at maximum afterburning. Unburned hydrocarbon emissions were low for most of the simulated flight conditions. The local NOX concentrations and their variability with power level increased with increasing flight Mach number at constant altitude, and decreased with increasing altitude at constant Mach number. Carbon dioxide emissions were proportional to local fuel air ratio for all conditions.

  7. Blocking Moving Window algorithm: Conditioning multiple-point simulations to hydrogeological data

    NASA Astrophysics Data System (ADS)

    Alcolea, Andres; Renard, Philippe

    2010-08-01

    Connectivity constraints and measurements of state variables contain valuable information on aquifer architecture. Multiple-point (MP) geostatistics allow one to simulate aquifer architectures, presenting a predefined degree of global connectivity. In this context, connectivity data are often disregarded. The conditioning to state variables is usually carried out by minimizing a suitable objective function (i.e., solving an inverse problem). However, the discontinuous nature of lithofacies distributions and of the corresponding objective function discourages the use of traditional sensitivity-based inversion techniques. This work presents the Blocking Moving Window algorithm (BMW), aimed at overcoming these limitations by conditioning MP simulations to hydrogeological data such as connectivity and heads. The BMW evolves iteratively until convergence: (1) MP simulation of lithofacies from geological/geophysical data and connectivity constraints, where only a random portion of the domain is simulated at every iteration (i.e., the blocking moving window, whose size is user-defined); (2) population of hydraulic properties at the intrafacies; (3) simulation of state variables; and (4) acceptance or rejection of the MP simulation depending on the quality of the fit of measured state variables. The outcome is a stack of MP simulations that (1) resemble a prior geological model depicted by a training image, (2) honor lithological data and connectivity constraints, (3) correlate with geophysical data, and (4) fit available measurements of state variables well. We analyze the performance of the algorithm on a 2-D synthetic example. Results show that (1) the size of the blocking moving window controls the behavior of the BMW, (2) conditioning to state variable data enhances dramatically the initial simulation (which accounts for geological/geophysical data only), and (3) connectivity constraints speed up the convergence but do not enhance the stack if the number of iterations

  8. Environmental Transmission Electron Microscopy Study of Diesel Carbon Soot Combustion under Simulated Catalytic-Reaction Conditions.

    PubMed

    Mori, Kohsuke; Watanabe, Keitaro; Sato, Takeshi; Yamashita, Hiromi

    2015-05-18

    Environmental transmission electron microscopy (ETEM) is used to monitor the catalytic combustion of diesel carbon soot upon exposure to molecular oxygen at elevated temperatures by using a gas-injection specimen heating holder. The reaction conditions simulated in the ETEM experiments reconstruct real conditions effectively. This study demonstrated for the first time that soot combustion occurs at the soot-catalyst interface for both Ag/CeO2 and Cu/BaO/La2 O3 catalysts.

  9. A convective-like energy-stable open boundary condition for simulations of incompressible flows

    NASA Astrophysics Data System (ADS)

    Dong, S.

    2015-12-01

    We present a new energy-stable open boundary condition, and an associated numerical algorithm, for simulating incompressible flows with outflow/open boundaries. This open boundary condition ensures the energy stability of the system, even when strong vortices or backflows occur at the outflow boundary. Under certain situations it can be reduced to a form that can be analogized to the usual convective boundary condition. One prominent feature of this boundary condition is that it provides a control over the velocity on the outflow/open boundary. This is not available with the other energy-stable open boundary conditions from previous works. Our numerical algorithm treats the proposed open boundary condition based on a rotational velocity-correction type strategy. It gives rise to a Robin-type condition for the discrete pressure and a Robin-type condition for the discrete velocity on the outflow/open boundary, respectively at the pressure and the velocity sub-steps. We present extensive numerical experiments on a canonical wake flow and a jet flow in open domain to test the effectiveness and performance of the method developed herein. Simulation results are compared with the experimental data as well as with other previous simulations to demonstrate the accuracy of the current method. Long-time simulations are performed for a range of Reynolds numbers, at which strong vortices and backflows occur at the outflow/open boundaries. The results show that our method is effective in overcoming the backflow instability, and that it allows for the vortices to discharge from the domain in a fairly natural fashion even at high Reynolds numbers.

  10. A digital computer simulation and study of a direct-energy-transfer power-conditioning system

    NASA Technical Reports Server (NTRS)

    Burns, W. W., III; Owen, H. A., Jr.; Wilson, T. G.; Rodriguez, G. E.; Paulkovich, J.

    1974-01-01

    A digital computer simulation technique, which can be used to study such composite power-conditioning systems, was applied to a spacecraft direct-energy-transfer power-processing system. The results obtained duplicate actual system performance with considerable accuracy. The validity of the approach and its usefulness in studying various aspects of system performance such as steady-state characteristics and transient responses to severely varying operating conditions are demonstrated experimentally.

  11. The empathic brain and its dysfunction in psychiatric populations: implications for intervention across different clinical conditions

    PubMed Central

    Decety, Jean; Moriguchi, Yoshiya

    2007-01-01

    Empathy is a concept central to psychiatry, psychotherapy and clinical psychology. The construct of empathy involves not only the affective experience of the other person's actual or inferred emotional state but also some minimal recognition and understanding of another's emotional state. It is proposed, in the light of multiple levels of analysis including social psychology, cognitive neuroscience and clinical neuropsychology, a model of empathy that involves both bottom-up and top-down information processing underpinned by parallel and distributed computational mechanisms. The predictive validity of this model is explored with reference to clinical conditions. As many psychiatric conditions are associated with deficits or even lack of empathy, we discuss a limited number of these disorders including psychopathy/antisocial personality disorders, borderline and narcissistic personality disorders, autistic spectrum disorders, and alexithymia. We argue that future clinical investigations of empathy disorders can only be informative if behavioral, dispositional and biological factors are combined. PMID:18021398

  12. Boundary conditions for simulations of oscillating bubbles using the non-linear acoustic approximation

    NASA Astrophysics Data System (ADS)

    King, J. R. C.; Ziolkowski, A. M.; Ruffert, M.

    2015-03-01

    We have developed a new boundary condition for finite volume simulations of oscillating bubbles. Our method uses an approximation to the motion outside the domain, based on the solution at the domain boundary. We then use this approximation to apply boundary conditions by defining incoming characteristic waves at the domain boundary. Our boundary condition is applicable in regions where the motion is close to spherically symmetric. We have tested our method on a range of one- and two-dimensional test cases. Results show good agreement with previous studies. The method allows simulations of oscillating bubbles for long run times (5 ×105 time steps with a CFL number of 0.8) on highly truncated domains, in which the boundary condition may be applied within 0.1% of the maximum bubble radius. Conservation errors due to the boundary conditions are found to be of the order of 0.1% after 105 time steps. The method significantly reduces the computational cost of fixed grid finite volume simulations of oscillating bubbles. Two-dimensional results demonstrate that highly asymmetric bubble features, such as surface instabilities and the formation of jets, may be captured on a small domain using this boundary condition.

  13. Students' Experiences of Learning Manual Clinical Skills through Simulation

    ERIC Educational Resources Information Center

    Johannesson, Eva; Silen, Charlotte; Kvist, Joanna; Hult, Hakan

    2013-01-01

    Learning manual skills is a fundamental part of health care education, and motor, sensory and cognitive learning processes are essential aspects of professional development. Simulator training has been shown to enhance factors that facilitate motor and cognitive learning. The present study aimed to investigate the students' experiences and…

  14. Defining boundary conditions for RANS predictions of urban flows using mesoscale simulations

    NASA Astrophysics Data System (ADS)

    Garcia Sanchez, Clara; Gorle, Catherine; van Beeck, Jeroen

    2015-11-01

    Pollutant dispersion and wind flows in urban canopies are major concerns for human health and energy, and the complex nature of the flow and transport processes remains a challenge when using Computational Fluid Dynamics (CFD) to predict wind flows. The definition of the inflow boundary condition in Reynolds-Averaged Navier-Stokes simulations (RANS) is one of the uncertainties that will strongly influence the prediction of the flow field, and thus, the dispersion pattern. The goal of the work presented is to define a methodology that improves the level of realism in the inflow condition for RANS simulations by accounting for larger mesoscale effects. The Weather Research and Forecasting model (WRF) is used to forecast mesoscale flow patterns, and two different approaches are used to define inflow conditions for the RANS simulations performed with OpenFOAM: 1) WRF variables such as local velocity magnitude, ABL height and friction velocity are directly interpolated onto the boundaries of the CFD domain; 2) WRF predictions for the geostrophic wind and friction velocity are applied as a forcing boundary condition. Simulations of the Joint Urban 2003 experimental campaign in Oklahoma City have been performed using both approaches and a comparison of the results will be presented.

  15. Particle model simulation of diffusion in low wind speed stable conditions

    NASA Astrophysics Data System (ADS)

    Brusasca, G.; Tinarelli, G.; Anfossi, D.

    A Lagrangian particle model (LAMDA), previously developed and applied to the simulation of atmospheric dispersion in neutral and convective windy conditions, was modified to deal with stable low wind speed conditions. These last are among the most difficult to be treated. In fact, on the one hand, nearly calm situations, associated to strong stability and air stagnation, make the lower layers of the atmosphere poorly diffusive, and, on the other hand, the large fluctuations in the wind direction (meandering), spread the airborne pollutants over wide angular sectors. An ad hoc algorithm to simulate the effect of meadering on the dispersion is proposed. The model is validated by comparing its simulation results to three tracer experiments held in stable low wind speed conditions by the Idaho National Engineering Laboratory (U.S.A.) in 1974. These experiments present plume spread of different width (48, 138 and 360°, respectively, at an arc located 200 m downwind from the source) and are comprehensive of a wide set of conditions, ranging from strong to weak stability and from low wind speed to calm. The results of the comparison are discussed. The ability of the model to simulate the g.l.c. distributions with a good degree of confidence is illustrated.

  16. An Alternative Frictional Boundary Condition for Computational Fluid Dynamics Simulation of Friction Stir Welding

    NASA Astrophysics Data System (ADS)

    Chen, Gaoqiang; Feng, Zhili; Zhu, Yucan; Shi, Qingyu

    2016-09-01

    For better application of numerical simulation in optimization and design of friction stir welding (FSW), this paper presents a new frictional boundary condition at the tool/workpiece interface for computational fluid dynamics (CFD) modeling of FSW. The proposed boundary condition is based on an implementation of the Coulomb friction model. Using the new boundary condition, the CFD simulation yields non-uniform distribution of contact state over the tool/workpiece interface, as validated by the experimental weld macrostructure. It is found that interfacial sticking state is present over large area at the tool-workpiece interface, while significant interfacial sliding occurs at the shoulder periphery, the lower part of pin side, and the periphery of pin bottom. Due to the interfacial sticking, a rotating flow zone is found under the shoulder, in which fast circular motion occurs. The diameter of the rotating flow zone is smaller than the shoulder diameter, which is attributed to the presence of the interfacial sliding at the shoulder periphery. For the simulated welding condition, the heat generation due to friction and plastic deformation makes up 54.4 and 45.6% of the total heat generation rate, respectively. The simulated temperature field is validated by the good agreement to the experimental measurements.

  17. The Impact of Preparation: Conditions for Developing Professional Knowledge through Simulations

    ERIC Educational Resources Information Center

    Sjöberg, David; Karp, Staffan; Söderström, Tor

    2015-01-01

    This article examines simulations of critical incidents in police education by investigating how activities in the preparation phase influence participants' actions and thus the conditions for learning professional knowledge. The study is based on interviews in two stages (traditional and stimulated recall interviews) with six selected students…

  18. STUDY OF SPECIATION OF MERCURY UNDER SIMULATED SCR NOX EMISSION CONTROL CONDITIONS

    EPA Science Inventory

    The paper focuses on the impact of SCR on elemental mercury (Hg0) oxidation. It describes the results of bench-scale experiments conducted to investigate Hg0 oxidation in the presence of simulated coal combustion flue gases and under SCR reaction conditions. Flue gas mixtures wit...

  19. Gambling on a Simulated Slot Machine under Conditions of Repeated Play

    ERIC Educational Resources Information Center

    Brandt, Andrew E.; Pietras, Cynthia J.

    2008-01-01

    A single-subject design was used in 2 experiments about the effects of percentage payback (winnings in proportion to total amount bet) on gambling on a slot-machine simulation in 8 adult humans. In Experiment 1, percentage payback was varied across a wide range of values, and participants were exposed extensively to percentage-payback conditions.…

  20. Reflecting boundary conditions for classical molecular dynamics simulations of nonideal plasmas

    NASA Astrophysics Data System (ADS)

    Lavrinenko, Ya S.; Morozov, I. V.; Valuev, I. A.

    2016-11-01

    The influence of boundary conditions on results of the classical molecular dynamics simulations of nonideal electron-ion plasma is analyzed. A comprehensive study is performed for the convergence of per-particle potential energy and pressure with the number of particles using both the nearest image method (periodic boundaries) and harmonic reflective boundaries. As a result an error caused by finiteness of the simulation box is estimated. Moreover the electron oscillations given by the spectra of the current autocorrelation function are analyzed for both types of the boundary conditions. Nonideal plasmas with the nonideality parameter in range 0.26-2.6 is considered. To speed up the classical molecular dynamics simulations the graphics accelerators code is used.

  1. Simulated Family Therapy Interviews in Clinical Social Work Education

    ERIC Educational Resources Information Center

    Mooradian, John K.

    2007-01-01

    This article describes a learning method that employed theatre students as family clients in an advanced social work practice course. Students were provided with an opportunity to integrate and apply their learning of theory, clinical skills, and professional conduct in full-length family therapy sessions that occurred in the classroom and were…

  2. Diagnosis and clinical management of gastrointestinal conditions in exotic companion mammals (rabbits, guinea pigs, and chinchillas).

    PubMed

    Ritzman, Tracey K

    2014-05-01

    Gastrointestinal disorders are common in exotic mammals such as rabbits, guinea pigs and chinchillas. Presenting clinical signs of gastrointestinal disease can vary widely. Small herbivores require specific dietary support and therapeutic treatments. Ileus is a common clinical condition and can be a primary or secondary disease. Common forms of treatment for ileus include fluid therapy, pain relief, nutritional support, and prokinetic therapy. The prognosis of the exotic mammal patient with gastrointestinal disease depends on the timing of the diagnosis and initiation of treatment. Surgical conditions such as gastrointestinal obstruction can have a good outcome if diagnosed early.

  3. Clinical simulation using deliberate practice in nursing education: a Wilsonian concept analysis.

    PubMed

    Chee, Jennifer

    2014-05-01

    Effective use of simulation is dependent on a complete understanding of simulation's central conceptual elements. Deliberate practice, a constituent of Ericsson's theory of expertise, has been identified as a central concept in effective simulation learning. Deliberate practice is compatible with simulation frameworks already being suggested for use in nursing education. This paper uses Wilson's Method of concept analysis for the purpose of exploring the concept of deliberate practice in the context of clinical simulation in nursing education. Nursing education should move forward in a manner that reflects best practice in nursing education.

  4. Influence of changes in initial conditions for the simulation of dynamic systems

    SciTech Connect

    Kotyrba, Martin

    2015-03-10

    Chaos theory is a field of study in mathematics, with applications in several disciplines including meteorology, sociology, physics, engineering, economics, biology, and philosophy. Chaos theory studies the behavior of dynamical systems that are highly sensitive to initial conditions—a paradigm popularly referred to as the butterfly effect. Small differences in initial conditions field widely diverging outcomes for such dynamical systems, rendering long-term prediction impossible in general. This happens even though these systems are deterministic, meaning that their future behavior is fully determined by their initial conditions, with no random elements involved. In this paperinfluence of changes in initial conditions will be presented for the simulation of Lorenz system.

  5. Tracer dispersion simulation in low wind speed conditions with a new 2D Langevin equation system

    NASA Astrophysics Data System (ADS)

    Anfossi, D.; Alessandrini, S.; Trini Castelli, S.; Ferrero, E.; Oettl, D.; Degrazia, G.

    The simulation of atmospheric dispersion in low wind speed conditions (LW) is still recognised as a challenge for modellers. Recently, a new system of two coupled Langevin equations that explicitly accounts for meandering has been proposed. It is based on the study of turbulence and dispersion properties in LW. The new system was implemented in the Lagrangian stochastic particle models LAMBDA and GRAL. In this paper we present simulations with this new approach applying it to the tracer experiments carried out in LW by Idaho National Engineering Laboratory (INEL, USA) in 1974 and by the Graz University of Technology and CNR-Torino near Graz in 2003. To assess the improvement obtained with the present model with respect to previous models not taking into account the meandering effect, the simulations for the INEL experiments were also performed with the old version of LAMBDA. The results of the comparisons clearly indicate that the new approach improves the simulation results.

  6. School nurse survival: reviewing clinical skills in the simulation laboratory.

    PubMed

    McKee, Sue; Bultas, Margaret; Ahearn, Tina

    2011-07-01

    School nursing is a specialty that requires nurses to provide holistic health care to a diverse population. Federal disability laws make it necessary for the school nurse to maintain and competently perform higher level technical skills--outside the home or hospital setting. Skills include tracheotomy care, gastric tube care, urinary catheterizations, central line care, oxygen delivery, ostomy care, and advanced assessment skills. How do school nurses maintain these skills if they are not used frequently enough to assure competency? The authors' college of nursing and a school outreach department have partnered to offer an annual school nurse conference. One option for participants is to use the simulation laboratory to refresh these skills and to review newer equipment and technology. The simulation laboratory staff and pediatric faculty are available to demonstrate and assist participants with skills technique. Participants have responded positively to this collaborative effort.

  7. Use of clinical simulations for patient education: targeting an untapped audience.

    PubMed

    Siwe, Karin; Berterö, Carina; Pugh, Carla; Wijma, Barbro

    2009-01-01

    In most cases, the health professional has been the target for simulation based learning curricula. We have developed a simulation based curriculum for patient education. In our curriculum lay-women learn how to perform the clinical female pelvic examination using a manikin-based trainer. Learner assessments show that prior negative expectations turned into positive expectations regarding future pelvic examinations.

  8. Thermal performance of MSFC hot air collectors under natural and simulated conditions

    NASA Technical Reports Server (NTRS)

    Shih, K., Sr.

    1977-01-01

    The procedures used and the results obtained from an evaluation test program conducted to determine the thermal performance and structural characteristics of selected MSFC--designed hot air collectors under both real and simulated environmental conditions are described. Five collectors were tested in the three phased program. A series of outdoor tests were conducted to determine stagnation temperatures on a typical bright day and to determine each collector's ability to withstand these temperatures. Two of the collectors experienced structural deformation sufficient to eliminate them from the remainder of the test program. A series of outdoor tests to evaluate the thermal performance of collector S/N 10 under certain test conditions were performed followed by a series of indoor tests to evaluate the thermal performance of the collector under closely controlled simulated conditions.

  9. Ejector nozzle test results at simulated flight conditions for an advanced supersonic transport propulsion system

    NASA Technical Reports Server (NTRS)

    Nelson, D. P.; Bresnahan, D. L.

    1983-01-01

    Results are presented of wind tunnel tests conducted to verify the performance improvements of a refined ejector nozzle design for advanced supersonic transport propulsion systems. The analysis of results obtained at simulated engine operating conditions is emphasized. Tests were conducted with models of approximately 1/10th scale which were configured to simulate nozzle operation at takeoff, subsonic cruise, transonic cruise, and supersonic cruise. Transonic cruise operation was not a consideration during the nozzle design phase, although an evaluation at this condition was later conducted. Test results, characterized by thrust and flow coefficients, are given for a range of nozzle pressure ratios, emphasizing the thrust performance at the engine operating conditions predicted for each flight Mach number. The results indicate that nozzle performance goals were met or closely approximated at takeoff and supersonic cruise, while subsonic cruise performance was within 2.3 percent of the goal with further improvement possible.

  10. Sensitivities of AGCM-Simulated Tropical Cyclones to Varying Initial Conditions

    NASA Astrophysics Data System (ADS)

    He, F.; Posselt, D. J.; Narisetty, N.; Zarzycki, C.; Nair, V.

    2013-12-01

    General Circulation Models (GCMs) have been increasingly used to simulate Tropical Cyclones (TCs) and predict their changes due to the effects of climate warming. As such, the motivation is to examine how the development of Tropical Cyclones (TCs) is represented in Atmospheric General circulation Models (AGCMs) and assesses the impact of changes in initial conditions, which include Radius of Maximum wind speed (RMW), Maximum wind speed (MWS), Sea surface temperature (SST), Environmental lapse rate (Gamma) and mid-level relative humidity (500-hPa RH), on modeled TCs. The National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM) has been used to simulate the development of idealized TCs over 10 days. A Latin Hypercube Sampling (LHS) method is used to generate two 300-member space-filling ensembles of simulations with grid resolution of 1×1 and 0.5 ×0.5 degree respectively. Composite analysis is first used to analyze the ensemble results, then, the Expanded Multivariate Adaptive Regression Splines (EMARS) method is implemented to characterize various TC response functions. Both 0.5 and 1.0 degree simulations produce a wide range of TC intensities ranging from tropical depression to category 4 or 5 on the Saffir-Simpson scale. On average, storms in the higher resolution simulations are stronger than those produced by the coarser-resolution model. Specifically, it is found that (1) the intensity, track, cloud, precipitation and radiative fields of simulated TCs are highly sensitive to changes in the initial vortex characteristics and surrounding environment; (2) nonlinear interaction between the initial conditions is crucial to the distribution of clouds, precipitation, and radiation of simulated TCs; (3) favorable initial conditions are able to produce intense and destructive TCs even in1 ×1 degree resolution global climate models; (4) inter-relationships exist among the cloud radiative forcing, cloud water content, precipitation and intensity

  11. An improved method of microencapsulation and its evaluation to protect Lactobacillus spp. in simulated gastric conditions.

    PubMed

    Chandramouli, V; Kailasapathy, K; Peiris, P; Jones, M

    2004-01-01

    An improved method of microencapsulation was developed to increase the efficacy of capsules in protecting the encapsulated bacteria under simulated gastric conditions. Lactobacillus acidophilus CSCC 2400 was encapsulated in calcium alginate and tested for its survival in simulated gastric conditions. The effects of different capsule sizes (200, 450, 1000 microm), different sodium alginate concentrations (0.75%, 1%, 1.5%, 1.8% and 2% w/v) and different concentrations of calcium chloride (0.1, 0.2, 1.0 M) on the viability of encapsulated bacteria were investigated. The viability of the cells in the microcapsules increased with an increase in alginate capsule size and gel concentration. There was no significant difference (p>0.05) in the viability of encapsulated cells when the concentration of calcium chloride was increased. Increase in cell load during encapsulation increased the number of bacterial survivors at the end of 3-h incubation in simulated gastric conditions. Hardening the capsule in calcium chloride solution for a longer time (8 h) had no impact on increasing the viability of encapsulated bacteria in a simulated gastric environment. The release of encapsulated cells at different phosphate buffer concentrations was also studied. When encapsulated L. acidophilus CSCC 2400 and L. acidophilus CSCC 2409 were subjected to low pH (pH 2) and high bile concentration (1.0% bile) under optimal encapsulation conditions (1.8% (w/v) alginate, 10(9) CFU/ml, 30 min hardening in 0.1 M CaCl(2) and capsule size 450 microm), there was a significant increase (p<0.05) in viable cell counts, compared to the free cells under similar conditions. Thus the encapsulation method described in this study may be effectively used to protect the lactobacillus from adverse gastric conditions.

  12. High-Fidelity Patient Simulators to Expose Undergraduate Students to the Clinical Relevance of Physiology Concepts

    ERIC Educational Resources Information Center

    Harris, David M.; Bellew, Christine; Cheng, Zixi J.; Cendán, Juan C.; Kibble, Jonathan D.

    2014-01-01

    The use of high-fidelity patient simulators (HFPSs) has expanded throughout medical, nursing, and allied health professions education in the last decades. These manikins can be programmed to represent pathological states and are used to teach clinical skills as well as clinical reasoning. First, the students are typically oriented either to the…

  13. Clinical validation of robot simulation of toothbrushing - comparative plaque removal efficacy

    PubMed Central

    2014-01-01

    Background Clinical validation of laboratory toothbrushing tests has important advantages. It was, therefore, the aim to demonstrate correlation of tooth cleaning efficiency of a new robot brushing simulation technique with clinical plaque removal. Methods Clinical programme: 27 subjects received dental cleaning prior to 3-day-plaque-regrowth-interval. Plaque was stained, photographically documented and scored using planimetrical index. Subjects brushed teeth 33–47 with three techniques (horizontal, rotating, vertical), each for 20s buccally and for 20s orally in 3 consecutive intervals. The force was calibrated, the brushing technique was video supported. Two different brushes were randomly assigned to the subject. Robot programme: Clinical brushing programmes were transfered to a 6-axis-robot. Artificial teeth 33–47 were covered with plaque-simulating substrate. All brushing techniques were repeated 7 times, results were scored according to clinical planimetry. All data underwent statistical analysis by t-test, U-test and multivariate analysis. Results The individual clinical cleaning patterns are well reproduced by the robot programmes. Differences in plaque removal are statistically significant for the two brushes, reproduced in clinical and robot data. Multivariate analysis confirms the higher cleaning efficiency for anterior teeth and for the buccal sites. Conclusions The robot tooth brushing simulation programme showed good correlation with clinically standardized tooth brushing. This new robot brushing simulation programme can be used for rapid, reproducible laboratory testing of tooth cleaning. PMID:24996973

  14. Teaching clinical reasoning and problem-solving skills using human patient simulation.

    PubMed

    Vyas, Deepti; Ottis, Erica J; Caligiuri, Frank J

    2011-11-10

    This paper discusses using human patient simulation (HPS) to expose students to complex dynamic patient cases that require clinical judgment, problem-solving skills, and teamwork skills for success. An example of an HPS exercise used to teach multifaceted clinical concepts in a therapeutics course also is provided.

  15. Sensitivity of Pliocene climate simulations in MRI-CGCM2.3 to respective boundary conditions

    NASA Astrophysics Data System (ADS)

    Kamae, Youichi; Yoshida, Kohei; Ueda, Hiroaki

    2016-08-01

    Accumulations of global proxy data are essential steps for improving reliability of climate model simulations for the Pliocene warming climate. In the Pliocene Model Intercomparison Project phase 2 (PlioMIP2), a part project of the Paleoclimate Modelling Intercomparison Project phase 4, boundary forcing data have been updated from the PlioMIP phase 1 due to recent advances in understanding of oceanic, terrestrial and cryospheric aspects of the Pliocene palaeoenvironment. In this study, sensitivities of Pliocene climate simulations to the newly archived boundary conditions are evaluated by a set of simulations using an atmosphere-ocean coupled general circulation model, MRI-CGCM2.3. The simulated Pliocene climate is warmer than pre-industrial conditions for 2.4 °C in global mean, corresponding to 0.6 °C warmer than the PlioMIP1 simulation by the identical climate model. Revised orography, lakes, and shrunk ice sheets compared with the PlioMIP1 lead to local and remote influences including snow and sea ice albedo feedback, and poleward heat transport due to the atmosphere and ocean that result in additional warming over middle and high latitudes. The amplified higher-latitude warming is supported qualitatively by the proxy evidences, but is still underestimated quantitatively. Physical processes responsible for the global and regional climate changes should be further addressed in future studies under systematic intermodel and data-model comparison frameworks.

  16. Conditioned Media from Microvascular Endothelial Cells Cultured in Simulated Microgravity Inhibit Osteoblast Activity

    PubMed Central

    Cazzaniga, Alessandra; Castiglioni, Sara; Maier, Jeanette A. M.

    2014-01-01

    Background and Aims. Gravity contributes to the maintenance of bone integrity. Accordingly, weightlessness conditions during space flight accelerate bone loss and experimental models in real and simulated microgravity show decreased osteoblastic and increased osteoclastic activities. It is well known that the endothelium and bone cells cross-talk and this intercellular communication is vital to regulate bone homeostasis. Because microgravity promotes microvascular endothelial dysfunction, we anticipated that the molecular cross-talk between endothelial cells exposed to simulated microgravity and osteoblasts might be altered. Results. We cultured human microvascular endothelial cells in simulated microgravity using the rotating wall vessel device developed by NASA. Endothelial cells in microgravity show growth inhibition and release higher amounts of matrix metalloproteases type 2 and interleukin-6 than controls. Conditioned media collected from microvascular endothelial cells in simulated microgravity were used to culture human osteoblasts and were shown to retard osteoblast proliferation and inhibit their activity. Discussion. Microvascular endothelial cells in microgravity are growth retarded and release high amounts of matrix metalloproteases type 2 and interleukin-6, which might play a role in retarding the growth of osteoblasts and impairing their osteogenic activity. Conclusions. We demonstrate that since simulated microgravity modulates microvascular endothelial cell function, it indirectly impairs osteoblastic function. PMID:25210716

  17. Role of Hfq in an animal-microbe symbiosis under simulated microgravity conditions

    NASA Astrophysics Data System (ADS)

    Grant, Kyle C.; Khodadad, Christina L. M.; Foster, Jamie S.

    2014-01-01

    Microgravity has a profound impact on the physiology of pathogenic microbes; however, its effects on mutualistic microbes are relatively unknown. To examine the effects of microgravity on those beneficial microbes that associate with animal tissues, we used the symbiosis between the bobtail squid Euprymna scolopes and a motile, luminescent bacterium, Vibrio fischeri as a model system. Specifically, we examined the role of Hfq, an RNA-binding protein known to be an important global regulator under space flight conditions, in the squid-vibrio symbiosis under simulated microgravity. To mimic a reduced gravity environment, the symbiotic partners were co-incubated in high-aspect-ratio rotating wall vessel bioreactors and examined at various stages of development. Results indicated that under simulated microgravity, hfq expression was down-regulated in V. fischeri. A mutant strain defective in hfq showed no colonization phenotype, indicating that Hfq was not required to initiate the symbiosis with the host squid. However, the hfq mutant showed attenuated levels of apoptotic cell death, a key symbiosis phenotype, within the host light organ suggesting that Hfq does contribute to normal light organ morphogenesis. Results also indicated that simulated microgravity conditions accelerated the onset of cell death in wild-type cells but not in the hfq mutant strains. These data suggest that Hfq plays an important role in the mutualism between V. fischeri and its animal host and that its expression can be negatively impacted by simulated microgravity conditions.

  18. The Blocking Moving Window Sampler. Conditioning Stochastic Multiple Point Simulations to non-local Hydrogeological Data.

    NASA Astrophysics Data System (ADS)

    Alcolea, A.; Renard, P.

    2008-12-01

    Geological scenarios often present well connected lithofacies distributions. Multiple Point statistical techniques have been traditionally used to delineate connectivity patterns from local lithofacies data in such scenarios. Yet, little attention has been paid to the conditioning to non-local connectivity data and dependent state variables (e.g., heads). These data sets contain valuable information on the connectivity patterns and must be accounted for in meaningful models. This work is a step in that direction. A novel direct iterative sampler, termed Blocking Moving Window (BMW) is presented. The BMW algorithm couples an MP simulator with a fast groundwater flow simulator. First, an MP simulation of lithofacies is delineated from training images, local lithofacies from available well logs and non-local connectivity data sets. Only a random portion of the domain (the Moving Window) is simulated at a given iteration. This makes the search less random and therefore, more efficient. Second, values of hydraulic properties at the intrafacies are assigned. Next, state variables are simulated. The MP simulation is rejected if the fit of measured state variables is poor. We analyze the performance of the BMW algorithm on a 2D toy example mimicking the groundwater flow to a well in a channel-type geological setting. We explore the sensitivity to the size of the Moving Window and the role of the state variable and non-local connectivity data sets. Results show that, (1) the size of the Moving Window must be optimum; (2) conditioning to state variables enhances dramatically the initial MP characterization (i.e., conditioned to raw geological data only) and (3) the use of non-local connectivity data increases the reliability of the characterization and speeds up the convergence of the algorithm.

  19. Epidemiology of Autism Spectrum Disorder in Portugal: Prevalence, Clinical Characterization, and Medical Conditions

    ERIC Educational Resources Information Center

    Oliveira, Guiomar; Ataide, Assuncao; Marques, Carla; Miguel, Teresa S.; Coutinho, Ana Margarida; Mota-Vieira, Luisa; Goncalves, Esmeralda; Lopes, Nazare Mendes; Rodrigues, Vitor; Carmona da Mota, Henrique; Vicente, Astrid Moura

    2007-01-01

    The objective of this study was to estimate the prevalence of autistic spectrum disorder (ASD) and identify its clinical characterization, and medical conditions in a paediatric population in Portugal. A school survey was conducted in elementary schools, targeting 332 808 school-aged children in the mainland and 10 910 in the Azores islands.…

  20. Use of simulation to understand the effects of task complexity and time away on clinical confidence.

    PubMed

    Cohen, Elaine; Ononye, Chiagozie; Salud, Jonathan; Kwan, Calvin; Salud, Lawrence; Pugh, Carla

    2013-01-01

    In prior studies, mannequin-based simulation training has been used to help decrease student anxiety toward intimate clinical examinations. Using time away as an independent variable, the aim of this study was to assess decay of clinical confidence for four procedural tasks that vary in procedural complexity. Clinical confidence with intimate examinations, after a standardized mannequin-based simulation curriculum, decays over time. This decay is noted after two months of time away. Longer periods of time away did not show increased differences.

  1. Simulation of pulmonary air flow with a subject-specific boundary condition.

    PubMed

    Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A; Tawhai, Merryn H; Lin, Ching-Long

    2010-08-10

    We present a novel image-based technique to estimate a subject-specific boundary condition (BC) for computational fluid dynamics (CFD) simulation of pulmonary air flow. The information of regional ventilation for an individual is derived by registering two computed tomography (CT) lung datasets and then passed to the CT-resolved airways as the flow BC. The CFD simulations show that the proposed method predicts lobar volume changes consistent with direct image-measured metrics, whereas the other two traditional BCs (uniform velocity or uniform pressure) yield lobar volume changes and regional pressure differences inconsistent with observed physiology.

  2. Simulation of pulmonary air flow with a subject-specific boundary condition

    PubMed Central

    Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A.; Tawhai, Merryn H.; Lin, Ching-Long

    2011-01-01

    We present a novel image-based technique to estimate a subject-specific boundary condition (BC) for computational fluid dynamics (CFD) simulation of pulmonary air flow. The information of regional ventilation for an individual is derived by registering two computed tomography (CT) lung datasets and then passed to the CT-resolved airways as the flow BC. The CFD simulations show that the proposed method predicts lobar volume changes consistent with direct image-measured metrics, whereas the other two traditional BCs (uniform velocity or uniform pressure) yield lobar volume changes and regional pressure differences inconsistent with observed physiology. PMID:20483412

  3. Monte Carlo simulation of high power microwave window breakdown at atmospheric conditions

    SciTech Connect

    Krile, John T.; Neuber, Andreas A.; Krompholz, Hermann G.; Gibson, Thomas L.

    2006-11-13

    A Monte Carlo-type electron motion simulation program was developed to calculate the increasing electron density for pulsed high power microwave window flashover in air and nitrogen at atmospheric pressures, i.e., >90 torr. Through comparison of experimental and simulated results several processes such as flashover delay time's strong dependence on pressure and the lack of significant surface charge buildup have been confirmed. The quantitative agreement of the code results with the experiment is a clear step towards predicting high power microwave flashover under a wide range of atmospheric conditions as well as for different gases and more complex window geometries.

  4. Simulation Evaluation of Controller-Managed Spacing Tools under Realistic Operational Conditions

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.; Hunt, Sarah M.; Prevot, Thomas

    2014-01-01

    Controller-Managed Spacing (CMS) tools have been developed to aid air traffic controllers in managing high volumes of arriving aircraft according to a schedule while enabling them to fly efficient descent profiles. The CMS tools are undergoing refinement in preparation for field demonstration as part of NASA's Air Traffic Management (ATM) Technology Demonstration-1 (ATD-1). System-level ATD-1 simulations have been conducted to quantify expected efficiency and capacity gains under realistic operational conditions. This paper presents simulation results with a focus on CMS-tool human factors. The results suggest experienced controllers new to the tools find them acceptable and can use them effectively in ATD-1 operations.

  5. Mathematic simulation of soil-vegetation condition and land use structure applying basin approach

    NASA Astrophysics Data System (ADS)

    Mishchenko, Natalia; Shirkin, Leonid; Krasnoshchekov, Alexey

    2016-04-01

    Ecosystems anthropogenic transformation is basically connected to the changes of land use structure and human impact on soil fertility. The Research objective is to simulate the stationary state of river basins ecosystems. Materials and Methods. Basin approach has been applied in the research. Small rivers basins of the Klyazma river have been chosen as our research objects. They are situated in the central part of the Russian plain. The analysis is carried out applying integrated characteristics of ecosystems functioning and mathematic simulation methods. To design mathematic simulator functional simulation methods and principles on the basis of regression, correlation and factor analysis have been applied in the research. Results. Mathematic simulation resulted in defining possible permanent conditions of "phytocenosis-soil" system in coordinates of phytomass, phytoproductivity, humus percentage in soil. Ecosystem productivity is determined not only by vegetation photosynthesis activity but also by the area ratio of forest and meadow phytocenosis. Local maximums attached to certain phytomass areas and humus content in soil have been defined on the basin phytoproductivity distribution diagram. We explain the local maximum by synergetic effect. It appears with the definite ratio of forest and meadow phytocenosis. In this case, utmost values of phytomass for the whole area are higher than just a sum of utmost values of phytomass for the forest and meadow phytocenosis. Efficient correlation of natural forest and meadow phytocenosis has been defined for the Klyazma river. Conclusion. Mathematic simulation methods assist in forecasting the ecosystem conditions under various changes of land use structure. Nowadays overgrowing of the abandoned agricultural lands is very actual for the Russian Federation. Simulation results demonstrate that natural ratio of forest and meadow phytocenosis for the area will restore during agricultural overgrowing.

  6. The Effect of Corner Modes in the Initial Conditions of Cosmological Simulations

    NASA Astrophysics Data System (ADS)

    Falck, B.; McCullagh, N.; Neyrinck, M. C.; Wang, J.; Szalay, A. S.

    2017-03-01

    In view of future high-precision large-scale structure surveys, it is important to quantify the percent and subpercent level effects in cosmological N-body simulations from which theoretical predictions are drawn. One such effect involves deciding whether to zero all modes above the one-dimensional Nyquist frequency, the so-called “corner” modes, in the initial conditions. We investigate this effect by comparing power spectra, density distribution functions, halo mass functions, and halo profiles in simulations with and without these modes. For a simulation with a mass resolution of {m}p∼ {10}11 {h}-1 {M}ȯ , we find that at z> 6, the difference in the matter power spectrum is large at wavenumbers above ∼80% of {k}{Ny}, reducing to below 2% at all scales by z∼ 3. Including corner modes results in a better match between low- and high-resolution simulations at wavenumbers around the Nyquist frequency of the low-resolution simulation, but the effect of the corner modes is smaller than the effect of particle discreteness. The differences in mass functions are 3% for the smallest halos at z = 6 for the {m}p∼ {10}11 {h}-1 {M}ȯ simulation, but we find no significant difference in the stacked profiles of well-resolved halos at z≤slant 6. Thus removing power at | {\\boldsymbol{k}}| > {k}{Ny} in the initial conditions of cosmological simulations has a small effect on small scales and high redshifts, typically below a few percent.

  7. Two Dimensional Numerical Simulations of the Turbulence Characteristics Over Rattlesnake Mountain during Stable and Unstable Conditions

    NASA Astrophysics Data System (ADS)

    Heilman, Warren Emanuel

    A two-dimensional second-order turbulence-closure model based on level three of the Mellor-Yamada turbulence hierarchy has been developed and used to examine the nocturnal and early morning turbulence characteristics over Rattlesnake Mountain in Washington. The model includes radiation, soil, canopy, and slope parameterizations for calculating mean and turbulence variables over two-dimensional terrain features. Simulations of mean horizontal velocities and potential temperatures show good agreement with data obtained over Rattlesnake Mountain during nocturnal drainage-flow conditions. Qualitative analysis of simulated turbulence fields during these conditions indicates significant variations over the windward and leeward slopes. Turbulence anisotropy develops in the drainage-flow region where vertical wind shears and atmospheric stability are large. The buoyant portion of the turbulent heat flux enhances the vertical component of turbulent kinetic energy, especially over the leeward slope. Derived turbulent diffusivities reflect the developed anisotropic turbulence conditions. Simulations of the atmospheric conditions over Rattlesnake Mountain during the early morning hours indicate significant growth of the convective boundary layer when the initial stability over the entire depth of the modeled region is very weak. Upslope flow develops when no ambient wind is present. The buoyancy-generated turbulence inhibits the formation of large upslope velocity maxima when ambient winds are present. Spatial variations in the turbulent kinetic energy develop over the mountain, but they are less than the variations during nocturnal drainage-flow conditions. Turbulence anisotropy is significant in the convective boundary layer. However, the developed anisotropy plays a minor role in affecting turbulent diffusivity magnitudes. The transition from nocturnal drainage-flow conditions to convective conditions is characterized by a redistribution of energy among the turbulent

  8. Combined statistical analyses for long-term stability data with multiple storage conditions: a simulation study.

    PubMed

    Almalik, Osama; Nijhuis, Michiel B; van den Heuvel, Edwin R

    2014-01-01

    Shelf-life estimation usually requires that at least three registration batches are tested for stability at multiple storage conditions. The shelf-life estimates are often obtained by linear regression analysis per storage condition, an approach implicitly suggested by ICH guideline Q1E. A linear regression analysis combining all data from multiple storage conditions was recently proposed in the literature when variances are homogeneous across storage conditions. The combined analysis is expected to perform better than the separate analysis per storage condition, since pooling data would lead to an improved estimate of the variation and higher numbers of degrees of freedom, but this is not evident for shelf-life estimation. Indeed, the two approaches treat the observed initial batch results, the intercepts in the model, and poolability of batches differently, which may eliminate or reduce the expected advantage of the combined approach with respect to the separate approach. Therefore, a simulation study was performed to compare the distribution of simulated shelf-life estimates on several characteristics between the two approaches and to quantify the difference in shelf-life estimates. In general, the combined statistical analysis does estimate the true shelf life more consistently and precisely than the analysis per storage condition, but it did not outperform the separate analysis in all circumstances.

  9. Simulation-Based Dysphagia Training: Teaching Interprofessional Clinical Reasoning in a Hospital Environment.

    PubMed

    Miles, Anna; Friary, Philippa; Jackson, Bianca; Sekula, Julia; Braakhuis, Andrea

    2016-06-01

    This study evaluated hospital readiness and interprofessional clinical reasoning in speech-language pathology and dietetics students following a simulation-based teaching package. Thirty-one students participated in two half-day simulation workshops. The training included orientation to the hospital setting, part-task skill learning and immersive simulated cases. Students completed workshop evaluation forms. They filled in a 10-question survey regarding confidence, knowledge and preparedness for working in a hospital environment before and immediately after the workshops. Students completed written 15-min clinical vignettes at 1 month prior to training, immediately prior to training and immediately after training. A marking rubric was devised to evaluate the responses to the clinical vignettes within a framework of interprofessional education. The simulation workshops were well received by all students. There was a significant increase in students' self-ratings of confidence, preparedness and knowledge following the study day (p < .001). There was a significant increase in student overall scores in clinical vignettes after training with the greatest increase in clinical reasoning (p < .001). Interprofessional simulation-based training has benefits in developing hospital readiness and clinical reasoning in allied health students.

  10. Age-related declines in car following performance under simulated fog conditions

    PubMed Central

    Ni, Rui; Kang, Julie J.; Andersen, George J.

    2010-01-01

    The present study examined age-related differences in car following performance when contrast of the driving scene was reduced by simulated fog. Older (mean age of 72.6) and younger (mean age of 21.1) drivers were presented with a car following scenario in a simulator in which a lead vehicle (LV) varied speed according to a sum of three sine wave functions. Drivers were shown an initial following distance of 18m and were asked to maintain headway distance by controlling speed to match changes in LV speed. Five simulated fog conditions were examined ranging from a no fog condition (contrast of 0.55) to a high fog condition (contrast of 0.03). Average LV speed varied across trials (40, 60, or 80 km/h). The results indicated age-related declines in car following performance for both headway distance and RMS (root mean square) error in matching speed. The greatest decline occurred at moderate speeds under the highest fog density condition, with older drivers maintaining a headway distance that was 21% closer than younger drivers. At higher speeds older drivers maintained a greater headway distance than younger drivers. These results suggest that older drivers may be at greater risk for a collision under high fog density and moderate speeds. PMID:20380908

  11. Simulated gastrointestinal pH condition improves antioxidant properties of wheat and rice flours.

    PubMed

    Chan, Kim Wei; Khong, Nicholas M H; Iqbal, Shahid; Ismail, Maznah

    2012-01-01

    The present study was conducted to evaluate the antioxidant properties of wheat and rice flours under simulated gastrointestinal pH condition. After subjecting the wheat and rice flour slurries to simulated gastrointestinal pH condition, both slurries were centrifuged to obtain the crude phenolic extracts for further analyses. Extraction yield, total contents of phenolic and flavonoids were determined as such (untreated) and under simulated gastrointestinal pH condition (treated). 1,1-diphenyl-2-picrylhydrazyl radical (DPPH(•)) scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS(•+)) scavenging activity, ferric reducing antioxidant power (FRAP), beta-carotene bleaching (BCB) and iron chelating activity assays were employed for the determination of antioxidant activity of the tested samples. In almost all of the assays performed, significant improvements in antioxidant properties (p < 0.05) were observed in both flours after treatment, suggesting that wheat and rice flours contain considerably heavy amounts of bound phenolics, and that their antioxidant properties might be improved under gastrointestinal digestive conditions.

  12. Age-related declines in car following performance under simulated fog conditions.

    PubMed

    Ni, Rui; Kang, Julie J; Andersen, George J

    2010-05-01

    The present study examined age-related differences in car following performance when contrast of the driving scene was reduced by simulated fog. Older (mean age of 72.6) and younger (mean age of 21.1) drivers were presented with a car following scenario in a simulator in which a lead vehicle (LV) varied speed according to a sum of three sine wave functions. Drivers were shown an initial following distance of 18 m and were asked to maintain headway distance by controlling speed to match changes in LV speed. Five simulated fog conditions were examined ranging from a no fog condition (contrast of 0.55) to a high fog condition (contrast of 0.03). Average LV speed varied across trials (40, 60, or 80 km/h). The results indicated age-related declines in car following performance for both headway distance and RMS (root mean square) error in matching speed. The greatest decline occurred at moderate speeds under the highest fog density condition, with older drivers maintaining a headway distance that was 21% closer than younger drivers. At higher speeds older drivers maintained a greater headway distance than younger drivers. These results suggest that older drivers may be at greater risk for a collision under high fog density and moderate speeds.

  13. Multiplication of certain soil micro-organisms under simulated Martian conditions.

    PubMed

    Imshenetsky, A A; Kusjurina, L A; Jakshina, V M

    1970-01-01

    According to earlier observations, severe UV irradiation kills all micro-organisms in a chamber with simulated Martian conditions. However, even a thin soil layer protects buried micro-organisms from UV irradiation. The chief limiting factor for microbial multiplication under simulated Martian conditions seems to be soil humidity. Several micro-organisms were isolated from harsh environments (e.g., from Arctic, Antarctic desert and high-mountain soil samples). A strain of an oligonitrophilic mycococcus, isolated from Dixon Island, proved to be most resistant to low humidity. It multiplied in a mixture of limonite (maximal hygroscopical humidity 3.8%) + 2% (w/w) garden soil kept in a chamber simulating Martian conditions. Total cell count increased 7.6-fold and, in some experiments, 26-fold in 14 days. The oligonitrophilic mycococcus was able to grow even at a humidity level of 2.5%, that is less than maximal hygroscopical (3.8%). Under these conditions cell count increased 10-fold in 36 days. Thus, it was shown that even in Earth soils there are xerophytic micro-organisms which are able to multiply in limonite of low humidity. These data might correct our current concepts concerning microbial water requirements. One might speculate that Martian micro-organisms belong to xerophytic species.

  14. Recognition and Evaluation of Clinical Section Headings in Clinical Documents Using Token-Based Formulation with Conditional Random Fields

    PubMed Central

    Dai, Hong-Jie; Syed-Abdul, Shabbir; Chen, Chih-Wei; Wu, Chieh-Chen

    2015-01-01

    Electronic health record (EHR) is a digital data format that collects electronic health information about an individual patient or population. To enhance the meaningful use of EHRs, information extraction techniques have been developed to recognize clinical concepts mentioned in EHRs. Nevertheless, the clinical judgment of an EHR cannot be known solely based on the recognized concepts without considering its contextual information. In order to improve the readability and accessibility of EHRs, this work developed a section heading recognition system for clinical documents. In contrast to formulating the section heading recognition task as a sentence classification problem, this work proposed a token-based formulation with the conditional random field (CRF) model. A standard section heading recognition corpus was compiled by annotators with clinical experience to evaluate the performance and compare it with sentence classification and dictionary-based approaches. The results of the experiments showed that the proposed method achieved a satisfactory F-score of 0.942, which outperformed the sentence-based approach and the best dictionary-based system by 0.087 and 0.096, respectively. One important advantage of our formulation over the sentence-based approach is that it presented an integrated solution without the need to develop additional heuristics rules for isolating the headings from the surrounding section contents. PMID:26380302

  15. Live or computerized simulation of clinical encounters: do clinicians work up patient cases differently?

    PubMed

    Nendaz, Mathieu R; Ponte, Belen; Gut, Anne M; Perrier, Arnaud; Louis-Simonet, Martine; Junod, Alain F; Vu, Nu V

    2006-03-01

    Computer simulation of clinical encounters is increasingly used in clinical settings to train patient work-up. The aim of this prospective, controlled study was to compare the characteristics of data collection and diagnostic exploration of physicians working up cases with a standardized patient and in a computerized simulation. Six clinicians of different clinical experience in internal medicine worked up three cases with a standardized patient and through a computer simulation allowing free inquiry. After each encounter, we asked the subjects to justify the information collected and to comment on their working diagnoses. The characteristics of data collected and working diagnoses generated were assessed and compared, according to the simulation method used. In the computer simulation, physicians limited their data collection and focused earlier and more specifically on information and working diagnoses with high levels of relevance. They reached a similar diagnostic accuracy and made decisions of a similar relevance. Computer simulation with a free-inquiry approach reproduces the data collection and the diagnostic exploration observed in a standardized-patient simulation and promotes an early collection of relevant data. Its contribution to extend the competence of learners in clinical settings should be further evaluated.

  16. Trophic interactions between viruses, bacteria and nanoflagellates under various nutrient conditions and simulated climate change.

    PubMed

    Bouvy, M; Bettarel, Y; Bouvier, C; Domaizon, I; Jacquet, S; Le Floc'h, E; Montanié, H; Mostajir, B; Sime-Ngando, T; Torréton, J P; Vidussi, F; Bouvier, T

    2011-07-01

    Population dynamics in the microbial food web are influenced by resource availability and predator/parasitism activities. Climatic changes, such as an increase in temperature and/or UV radiation, can also modify ecological systems in many ways. A series of enclosure experiments was conducted using natural microbial communities from a Mediterranean lagoon to assess the response of microbial communities to top-down control [grazing by heterotrophic nanoflagellates (HNF), viral lysis] and bottom-up control (nutrients) under various simulated climatic conditions (temperature and UV-B radiations). Different biological assemblages were obtained by separating bacteria and viruses from HNF by size fractionation which were then incubated in whirl-Pak bags exposed to an increase of 3°C and 20% UV-B above the control conditions for 96 h. The assemblages were also provided with an inorganic and organic nutrient supply. The data show (i) a clear nutrient limitation of bacterial growth under all simulated climatic conditions in the absence of HNF, (ii) a great impact of HNF grazing on bacteria irrespective of the nutrient conditions and the simulated climatic conditions, (iii) a significant decrease in burst size (BS) (number of intracellular lytic viruses per bacterium) and a significant increase of VBR (virus to bacterium ratio) in the presence of HNF, and (iv) a much larger temperature effect than UV-B radiation effect on the bacterial dynamics. These results show that top-down factors, essentially HNF grazing, control the dynamics of the lagoon bacterioplankton assemblage and that short-term simulated climate changes are only a secondary effect controlling microbial processes.

  17. Numerical Simulation of Groundwater Conditions in a Coastal Aquifer, Southern California, USA

    NASA Astrophysics Data System (ADS)

    Stolp, B. J.; Anders, R.; Danskin, W. R.

    2014-12-01

    Development of local groundwater resources in coastal areas is influenced by freshwater recharge and discharge, topography, geologic structure, and changes in sea level. For the coastal San Diego area, a density-dependent cross-sectional groundwater flow model was constructed to examine the aquifer and flow characteristics. The model domain represents generalized conditions along an east-west transect that is described by data from two multiple-depth monitoring-well sites; the domain extends into the Pacific Ocean to the 120 meter (m) bathymetric contour. Vertically, the model was discretized into four zones that represent geologic formations; each zone was assigned a horizontal permeability based on aquifer testing. Temporally, the model was divided into two stress periods. The first stress period simulates pre-development conditions, with an instantaneous sea-level rise of 120 m starting 6,000 years ago. This is a simplified representation of transient conditions since the last glacial maximum. The second stress period simulates 60 years of groundwater development, which is represented in terms of net fresh water flow through the domain. Near the coast, observed water-quality data indicate (1) brackish-to-hypersaline groundwater at shallow depths, (2) fresh continental recharge at intermediate depths, and (3) seawater intrusion at depths greater than 300 m. In order to simulate these general groundwater conditions, vertical anisotropy of the upper permeability zone was increased, freshwater discharge was constrained to the seafloor (no discharge along the coast), and groundwater development was simulated as exceeding freshwater recharge (additional water is provided by depletion of freshwater reserves). This numerical testing identifies specific factors that influence current conditions and provides an initial assessment of resource management alternatives for the San Diego coastal aquifer.

  18. Magnetic resonance imaging-conditional devices: Luxury or real clinical need?

    PubMed

    Mavrogeni, Sophie I; Poulos, George; Kolovou, Genovefa; Theodorakis, George

    2017-01-10

    Although the risk of MRI scanning on patients with conventional devices is lower than initially thought, the patient's safety can only be guaranteed when using MRI-conditional devices. The most important modifications in MRI-conditional devices include a) Reduction in ferromagnetic components to reduce magnetic attraction and susceptibility artifacts; b) Replacement of the reed switch by a Hall sensor in order to avoid unpredictable reed switch behavior; c) Lead coil design to minimize lead heating and electrical current induction; d) Filter circuitry to prevent damage to the internal power supply; and e) Dedicated pacemaker programming to prevent inappropriate pacemaker inhibition and competing rhythms. Although many companies claim to have MRI-conditional devices, adoption in clinical practice is limited because a) Not all companies have MRI-conditional devices approved for both 1.5 and 3T; b) Not all companies offer the option of unlimited MRI scanning (without an exclusion zone in the thorax); c) Certain companies allow only a 30-min MRI scanning and only in afebrile patients; and d) Despite having MRI-conditional pacemakers, certain companies do not have MRI-conditional defibrillators and CRT systems. It is clear that this new technology opens the door for MRI to a growing number of patients; however, the widespread adoption of MRI-conditional devices will depend on real-life issues, such as cost, clinical indications for such a device and the permanent education of health care professionals.

  19. Accelerated prompt gamma estimation for clinical proton therapy simulations

    NASA Astrophysics Data System (ADS)

    Huisman, Brent F. B.; Létang, J. M.; Testa, É.; Sarrut, D.

    2016-11-01

    There is interest in the particle therapy community in using prompt gammas (PGs), a natural byproduct of particle treatment, for range verification and eventually dose control. However, PG production is a rare process and therefore estimation of PGs exiting a patient during a proton treatment plan executed by a Monte Carlo (MC) simulation converges slowly. Recently, different approaches to accelerating the estimation of PG yield have been presented. Sterpin et al (2015 Phys. Med. Biol. 60 4915-46) described a fast analytic method, which is still sensitive to heterogeneities. El Kanawati et al (2015 Phys. Med. Biol. 60 8067-86) described a variance reduction method (pgTLE) that accelerates the PG estimation by precomputing PG production probabilities as a function of energy and target materials, but has as a drawback that the proposed method is limited to analytical phantoms. We present a two-stage variance reduction method, named voxelized pgTLE (vpgTLE), that extends pgTLE to voxelized volumes. As a preliminary step, PG production probabilities are precomputed once and stored in a database. In stage 1, we simulate the interactions between the treatment plan and the patient CT with low statistic MC to obtain the spatial and spectral distribution of the PGs. As primary particles are propagated throughout the patient CT, the PG yields are computed in each voxel from the initial database, as a function of the current energy of the primary, the material in the voxel and the step length. The result is a voxelized image of PG yield, normalized to a single primary. The second stage uses this intermediate PG image as a source to generate and propagate the number of PGs throughout the rest of the scene geometry, e.g. into a detection device, corresponding to the number of primaries desired. We achieved a gain of around 103 for both a geometrical heterogeneous phantom and a complete patient CT treatment plan with respect to analog MC, at a convergence level of 2% relative

  20. Congenital Uterine Arteriovenous Malformation Presenting as Postcoital bleeding: A Rare Presentation of a Rare Clinical Condition

    PubMed Central

    Agarwal, Neha; Chopra, Seema; Aggarwal, Neelam; Gorsi, Ujjwal

    2017-01-01

    Congenital uterine arteriovenous malformation (AVM) is an extremely rare condition with <100 cases documented in literature. We report multiparous women presenting to us with a history of postcoital bleed. Initial Doppler ultrasonography was consistent with features suggestive of AVM. Subsequently, computed tomography (CT) angiography confirmed the diagnosis. Embolization was chosen as the treatment because of the large extension of AVM and the risk of hemorrhage during hysterectomy. The patient was discharged in a stable condition with a plan of repeat embolization in the next setting. At 6 and 12 weeks of follow-up, she did not experience any further episodes of bleed. The purpose of this case report is to highlight the salient clinical features, diagnosis, and the management options available for this rare clinical condition.

  1. River basin soil-vegetation condition assessment applying mathematic simulation methods

    NASA Astrophysics Data System (ADS)

    Mishchenko, Natalia; Trifonova, Tatiana; Shirkin, Leonid

    2013-04-01

    Meticulous attention paid nowadays to the problem of vegetation cover productivity changes is connected also to climate global transformation. At the same time ecosystems anthropogenic transformation, basically connected to the changes of land use structure and human impact on soil fertility, is developing to a great extent independently from climatic processes and can seriously influence vegetation cover productivity not only at the local and regional levels but also globally. Analysis results of land use structure and soil cover condition influence on river basin ecosystems productive potential is presented in the research. The analysis is carried out applying integrated characteristics of ecosystems functioning, space images processing results and mathematic simulation methods. The possibility of making permanent functional simulator defining connection between macroparameters of "phytocenosis-soil" system condition on the basis of basin approach is shown. Ecosystems of river catchment basins of various degrees located in European part of Russia were chosen as research objects. For the integrated assessment of ecosystems soil and vegetation conditions the following characteristics have been applied: 1. Soil-productional potential, characterizing the ability of natural and natural-anthropogenic ecosystem in certain soil-bioclimatic conditions for long term reproduction. This indicator allows for specific phytomass characteristics and ecosystem produce, humus content in soil and bioclimatic parameters. 2. Normalized difference vegetation index (NDVI) has been applied as an efficient, remotely defined, monitoring indicator characterizing spatio-temporal unsteadiness of soil-productional potential. To design mathematic simulator functional simulation methods and principles on the basis of regression, correlation and factor analysis have been applied in the research. Coefficients values defining in the designed static model of phytoproductivity distribution has been

  2. Exploring a New Simulation Approach to Improve Clinical Reasoning Teaching and Assessment: Randomized Trial Protocol

    PubMed Central

    Moussa, Ahmed; Loye, Nathalie; Charlin, Bernard; Audétat, Marie-Claude

    2016-01-01

    Background Helping trainees develop appropriate clinical reasoning abilities is a challenging goal in an environment where clinical situations are marked by high levels of complexity and unpredictability. The benefit of simulation-based education to assess clinical reasoning skills has rarely been reported. More specifically, it is unclear if clinical reasoning is better acquired if the instructor's input occurs entirely after or is integrated during the scenario. Based on educational principles of the dual-process theory of clinical reasoning, a new simulation approach called simulation with iterative discussions (SID) is introduced. The instructor interrupts the flow of the scenario at three key moments of the reasoning process (data gathering, integration, and confirmation). After each stop, the scenario is continued where it was interrupted. Finally, a brief general debriefing ends the session. System-1 process of clinical reasoning is assessed by verbalization during management of the case, and System-2 during the iterative discussions without providing feedback. Objective The aim of this study is to evaluate the effectiveness of Simulation with Iterative Discussions versus the classical approach of simulation in developing reasoning skills of General Pediatrics and Neonatal-Perinatal Medicine residents. Methods This will be a prospective exploratory, randomized study conducted at Sainte-Justine hospital in Montreal, Qc, between January and March 2016. All post-graduate year (PGY) 1 to 6 residents will be invited to complete one SID or classical simulation 30 minutes audio video-recorded complex high-fidelity simulations covering a similar neonatology topic. Pre- and post-simulation questionnaires will be completed and a semistructured interview will be conducted after each simulation. Data analyses will use SPSS and NVivo softwares. Results This study is in its preliminary stages and the results are expected to be made available by April, 2016. Conclusions

  3. Groundwater recharge simulation under the steady-state and transient climate conditions

    NASA Astrophysics Data System (ADS)

    Pozdniakov, S.; Lykhina, N.

    2010-03-01

    Groundwater recharge simulation under the steady-state and transient climate conditions Diffusive groundwater recharge is a vertical water flux through the water table, i.e. through the boundary between the unsaturated and saturated zones. This flux features temporal and spatial changes due to variations in the climatic conditions, landscape the state of vegetation, and the spatial variability of vadoze zone characteristics. In a changing climate the non-steady state series of climatic characteristics will affect on the groundwater recharge.. A well-tested approach to calculating water flux through the vadoze zone is the application of Richard’s equations for a heterogeneous one-domain porosity continuum with specially formulated atmospheric boundary conditions at the ground surface. In this approach the climatic parameters are reflected in upper boundary conditions, while the recharge series is the flux through the low boundary. In this work developed by authors code Surfbal that simulates water cycle at surface of topsoil to take into account the various condition of precipitation transformation at the surface in different seasons under different vegetation cover including snow accumulation in winter and melting in spring is used to generate upper boundary condition at surface of topsoil for world-wide known Hydrus-1D code (Simunek et al, 2008). To estimate the proposal climate change effect we performed Surfbal and Hydrus simulation using the steady state climatic condition and transient condition due to global warming on example of Moscow region, Russia. The following scenario of climate change in 21 century in Moscow region was selected: the annual temperature will increase on 4C during 100 year and annual precipitation will increase on 10% (Solomon et al, 2007). Within the year the maximum increasing of temperature and precipitation falls on winter time, while in middle of summer temperature will remain almost the same as observed now and monthly

  4. Survival of methanogenic archaea from Siberian permafrost under simulated Martian thermal conditions.

    PubMed

    Morozova, Daria; Möhlmann, Diedrich; Wagner, Dirk

    2007-04-01

    Methanogenic archaea from Siberian permafrost complementary to the already well-studied methanogens from non-permafrost habitats were exposed to simulated Martian conditions. After 22 days of exposure to thermo-physical conditions at Martian low- and mid-latitudes up to 90% of methanogenic archaea from Siberian permafrost survived in pure cultures as well as in environmental samples. In contrast, only 0.3%-5.8% of reference organisms from non-permafrost habitats survived at these conditions. This suggests that methanogens from terrestrial permafrost seem to be remarkably resistant to Martian conditions. Our data also suggest that in scenario of subsurface lithoautotrophic life on Mars, methanogenic archaea from Siberian permafrost could be used as appropriate candidates for the microbial life on Mars.

  5. Evaluation of wall boundary condition parameters for gas-solids fluidized bed simulations

    SciTech Connect

    Li, Tingwen; Benyahia, Sofiane

    2013-10-01

    Wall boundary conditions for the solids phase have significant effects on numerical predictions of various gas-solids fluidized beds. Several models for the granular flow wall boundary condition are available in the open literature for numerical modeling of gas-solids flow. In this study, a model for specularity coefficient used in Johnson and Jackson boundary conditions by Li and Benyahia (AIChE Journal, 2012, 58, 2058-2068) is implemented in the open-source CFD code-MFIX. The variable specularity coefficient model provides a physical way to calculate the specularity coefficient needed by the partial-slip boundary conditions for the solids phase. Through a series of 2-D numerical simulations of bubbling fluidized bed and circulating fluidized bed riser, the model predicts qualitatively consistent trends to the previous studies. Furthermore, a quantitative comparison is conducted between numerical results of variable and constant specularity coefficients to investigate the effect of spatial and temporal variations in specularity coefficient.

  6. Psycho-physiological monitoring in real and simulated space flight conditions.

    PubMed

    Larina, I M; Bystritzkaya, A F; Smirnova, T M

    1997-07-01

    Earlier in simulating experiments from long isolation of small group in hermetic cabin we were found out the significant interrelation between changes physiological parameters and subjective appraisal of a condition, activity regulating systems of organism, individual variability of a colour choice, and also quality of operator's activity. On the basis of these results we develop a method of psychophysiological monitoring. The important component of a method is study of the variational characteristics of registered parameters, with the purpose of reception of the information about character of transients in organism. The present research is carried out in conditions of 135-daily isolation in a breadboard model MIR station (experiment HUBES). Its PURPOSE was study of dynamic psycho-emotional condition, simultaneously with study physiological and biochemical parameters, describing process of adaptation to complex conditions of ability to live. Besides were analyzed the results of circadian rhythm's researches during space flights of 6 Russian cosmonauts (duration from 70 till 182 days) on orbital MIR station.

  7. Simulations of string vibrations with boundary conditions of third kind using the functional transformation method

    NASA Astrophysics Data System (ADS)

    Trautmann, L.; Petrausch, S.; Bauer, M.

    2005-09-01

    The functional transformation method (FTM) is an established mathematical method for accurate simulation of multidimensional physical systems from various fields of science, including optics, heat and mass transfer, electrical engineering, and acoustics. It is a frequency-domain method based on the decomposition into eigenvectors and eigenfrequencies of the underlying physical problem. In this article, the FTM is applied to real-time simulations of vibrating strings which are ideally fixed at one end while the fixing at the other end is modeled by a frequency-dependent input impedance. Thus, boundary conditions of third kind are applied to the model at the end fixed with the input impedance. It is shown that accurate and stable simulations are achieved with nearly the same computational cost as with strings ideally fixed at both ends.

  8. Driver steering dynamics measured in car simulator under a range of visibility and roadmaking conditions

    NASA Technical Reports Server (NTRS)

    Allen, R. W.; Mcruer, D. T.

    1977-01-01

    A simulation experiment was conducted to determine the effect of reduced visibility on driver lateral (steering) control. The simulator included a real car cab and a single lane road image projected on a screen six feet in front of the driver. Simulated equations of motion controlled apparent car lane position in response to driver steering actions, wind gusts, and road curvature. Six drivers experienced a range of visibility conditions at various speeds with assorted roadmaking configurations (mark and gap lengths). Driver describing functions were measured and detailed parametric model fits were determined. A pursuit model employing a road curvature feedforward was very effective in explaining driver behavior in following randomly curving roads. Sampled-data concepts were also effective in explaining the combined effects of reduced visibility and intermittent road markings on the driver's dynamic time delay. The results indicate the relative importance of various perceptual variables as the visual input to the driver's steering control process is changed.

  9. Simulating the dynamic behavior of a vertical axis wind turbine operating in unsteady conditions

    NASA Astrophysics Data System (ADS)

    Battisti, L.; Benini, E.; Brighenti, A.; Soraperra, G.; Raciti Castelli, M.

    2016-09-01

    The present work aims at assessing the reliability of a simulation tool capable of computing the unsteady rotational motion and the associated tower oscillations of a variable speed VAWT immersed in a coherent turbulent wind. As a matter of fact, since the dynamic behaviour of a variable speed turbine strongly depends on unsteady wind conditions (wind gusts), a steady state approach can't accurately catch transient correlated issues. The simulation platform proposed here is implemented using a lumped mass approach: the drive train is described by resorting to both the polar inertia and the angular position of rotating parts, also considering their speed and acceleration, while rotor aerodynamic is based on steady experimental curves. The ultimate objective of the presented numerical platform is the simulation of transient phenomena, driven by turbulence, occurring during rotor operation, with the aim of supporting the implementation of efficient and robust control algorithms.

  10. Importance of inlet boundary conditions for numerical simulation of combustor flows

    NASA Technical Reports Server (NTRS)

    Sturgess, G. J.; Syed, S. A.; Mcmanus, K. R.

    1983-01-01

    Fluid dynamic computer codes for the mathematical simulation of problems in gas turbine engine combustion systems are required as design and diagnostic tools. To eventually achieve a performance standard with these codes of more than qualitative accuracy it is desirable to use benchmark experiments for validation studies. Typical of the fluid dynamic computer codes being developed for combustor simulations is the TEACH (Teaching Elliptic Axisymmetric Characteristics Heuristically) solution procedure. It is difficult to find suitable experiments which satisfy the present definition of benchmark quality. For the majority of the available experiments there is a lack of information concerning the boundary conditions. A standard TEACH-type numerical technique is applied to a number of test-case experiments. It is found that numerical simulations of gas turbine combustor-relevant flows can be sensitive to the plane at which the calculations start and the spatial distributions of inlet quantities for swirling flows.

  11. Initial conditions for accurate N-body simulations of massive neutrino cosmologies

    NASA Astrophysics Data System (ADS)

    Zennaro, M.; Bel, J.; Villaescusa-Navarro, F.; Carbone, C.; Sefusatti, E.; Guzzo, L.

    2017-04-01

    The set-up of the initial conditions in cosmological N-body simulations is usually implemented by rescaling the desired low-redshift linear power spectrum to the required starting redshift consistently with the Newtonian evolution of the simulation. The implementation of this practical solution requires more care in the context of massive neutrino cosmologies, mainly because of the non-trivial scale-dependence of the linear growth that characterizes these models. In this work, we consider a simple two-fluid, Newtonian approximation for cold dark matter and massive neutrinos perturbations that can reproduce the cold matter linear evolution predicted by Boltzmann codes such as CAMB or CLASS with a 0.1 per cent accuracy or below for all redshift relevant to non-linear structure formation. We use this description, in the first place, to quantify the systematic errors induced by several approximations often assumed in numerical simulations, including the typical set-up of the initial conditions for massive neutrino cosmologies adopted in previous works. We then take advantage of the flexibility of this approach to rescale the late-time linear power spectra to the simulation initial redshift, in order to be as consistent as possible with the dynamics of the N-body code and the approximations it assumes. We implement our method in a public code (REPS rescaled power spectra for initial conditions with massive neutrinos https://github.com/matteozennaro/reps) providing the initial displacements and velocities for cold dark matter and neutrino particles that will allow accurate, i.e. 1 per cent level, numerical simulations for this cosmological scenario.

  12. Scaffold-free Tissue Formation Under Real and Simulated Microgravity Conditions.

    PubMed

    Aleshcheva, Ganna; Bauer, Johann; Hemmersbach, Ruth; Slumstrup, Lasse; Wehland, Markus; Infanger, Manfred; Grimm, Daniela

    2016-10-01

    Scaffold-free tissue formation in microgravity is a new method in regenerative medicine and an important topic in Space Medicine. In this MiniReview, we focus on recent findings in the field of tissue engineering that were observed by exposing cells to real microgravity in space or to devices simulating to at least some extent microgravity conditions on Earth (ground-based facilities). Under both conditions - real and simulated microgravity - a part of the cultured cells of various populations detaches from the bottom of a culture flask. The cells form three-dimensional (3D) aggregates resembling the organs from which the cells have been derived. As spaceflights are rare and extremely expensive, cell culture under simulated microgravity allows more comprehensive and frequent studies on the scaffold-free 3D tissue formation in some aspects, as a number of publications have proven during the last two decades. In this MiniReview, we summarize data from our own studies and work from various researchers about tissue engineering of multi-cellular spheroids formed by cancer cells, tube formation by endothelial cells and cartilage formation by exposing the cells to ground-based facilities such as the 3D Random Positioning Machine (RPM), the 2D Fast-Rotating Clinostat (FRC) or the Rotating Wall Vessel (RWV). Subsequently, we investigated self-organization of 3D aggregates without scaffolds pursuing to enhance the frequency of 3D formation and to enlarge the size of the organ-like aggregates. The density of the monolayer exposed to real or simulated microgravity as well as the composition of the culture media revealed an impact on the results. Genomic and proteomic alterations were induced by simulated microgravity. Under microgravity conditions, adherent cells expressed other genes than cells grown in spheroids. In this MiniReview, the recent improvements in scaffold-free tissue formation are summarized and relationships between phenotypic and molecular appearance are

  13. Mapping and Simulating Systematics due to Spatially Varying Observing Conditions in DES Science Verification Data

    NASA Astrophysics Data System (ADS)

    Leistedt, B.; Peiris, H. V.; Elsner, F.; Benoit-Lévy, A.; Amara, A.; Bauer, A. H.; Becker, M. R.; Bonnett, C.; Bruderer, C.; Busha, M. T.; Carrasco Kind, M.; Chang, C.; Crocce, M.; da Costa, L. N.; Gaztanaga, E.; Huff, E. M.; Lahav, O.; Palmese, A.; Percival, W. J.; Refregier, A.; Ross, A. J.; Rozo, E.; Rykoff, E. S.; Sánchez, C.; Sadeh, I.; Sevilla-Noarbe, I.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Wechsler, R. H.; Abdalla, F. B.; Allam, S.; Banerji, M.; Bernstein, G. M.; Bernstein, R. A.; Bertin, E.; Bridle, S. L.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Fausti Neto, A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; James, D. J.; Jarvis, M.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Li, T. S.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Miller, C. J.; Miquel, R.; Nichol, R. C.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Romer, A. K.; Roodman, A.; Sanchez, E.; Santiago, B.; Scarpine, V.; Schubnell, M.; Smith, R. C.; Soares-Santos, M.; Tarle, G.; Thaler, J.; Thomas, D.; Vikram, V.; Walker, A. R.; Wester, W.; Zhang, Y.; Zuntz, J.

    2016-10-01

    Spatially varying depth and the characteristics of observing conditions, such as seeing, airmass, or sky background, are major sources of systematic uncertainties in modern galaxy survey analyses, particularly in deep multi-epoch surveys. We present a framework to extract and project these sources of systematics onto the sky, and apply it to the Dark Energy Survey (DES) to map the observing conditions of the Science Verification (SV) data. The resulting distributions and maps of sources of systematics are used in several analyses of DES-SV to perform detailed null tests with the data, and also to incorporate systematics in survey simulations. We illustrate the complementary nature of these two approaches by comparing the SV data with BCC-UFig, a synthetic sky catalog generated by forward-modeling of the DES-SV images. We analyze the BCC-UFig simulation to construct galaxy samples mimicking those used in SV galaxy clustering studies. We show that the spatially varying survey depth imprinted in the observed galaxy densities and the redshift distributions of the SV data are successfully reproduced by the simulation and are well-captured by the maps of observing conditions. The combined use of the maps, the SV data, and the BCC-UFig simulation allows us to quantify the impact of spatial systematics on N(z), the redshift distributions inferred using photometric redshifts. We conclude that spatial systematics in the SV data are mainly due to seeing fluctuations and are under control in current clustering and weak-lensing analyses. However, they will need to be carefully characterized in upcoming phases of DES in order to avoid biasing the inferred cosmological results. The framework presented here is relevant to all multi-epoch surveys and will be essential for exploiting future surveys such as the Large Synoptic Survey Telescope, which will require detailed null tests and realistic end-to-end image simulations to correctly interpret the deep, high-cadence observations

  14. Mapping and simulating systematics due to spatially varying observing conditions in DES science verification data

    SciTech Connect

    Leistedt, B.; Peiris, H. V.; Elsner, F.; Benoit-Lévy, A.; Amara, A.; Bauer, A. H.; Becker, M. R.; Bonnett, C.; Bruderer, C.; Busha, M. T.; Kind, M. Carrasco; Chang, C.; Crocce, M.; da Costa, L. N.; Gaztanaga, E.; Huff, E. M.; Lahav, O.; Palmese, A.; Percival, W. J.; Refregier, A.; Ross, A. J.; Rozo, E.; Rykoff, E. S.; Sánchez, C.; Sadeh, I.; Sevilla-Noarbe, I.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Wechsler, R. H.; Abdalla, F. B.; Allam, S.; Banerji, M.; Bernstein, G. M.; Bernstein, R. A.; Bertin, E.; Bridle, S. L.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Rosell, A. Carnero; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Neto, A. Fausti; Flaugher, B.; Fosalba, P.; Frieman, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; James, D. J.; Jarvis, M.; Kent, S.; Kuehn, K.; Kuropatkin, N.; Li, T. S.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Martini, P.; Melchior, P.; Miller, C. J.; Miquel, R.; Nichol, R. C.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Romer, A. K.; Roodman, A.; Sanchez, E.; Santiago, B.; Scarpine, V.; Schubnell, M.; Smith, R. C.; Soares-Santos, M.; Tarle, G.; Thaler, J.; Thomas, D.; Vikram, V.; Walker, A. R.; Wester, W.; Zhang, Y.; Zuntz, J.

    2016-10-17

    Spatially varying depth and the characteristics of observing conditions, such as seeing, airmass, or sky background, are major sources of systematic uncertainties in modern galaxy survey analyses, particularly in deep multi-epoch surveys. We present a framework to extract and project these sources of systematics onto the sky, and apply it to the Dark Energy Survey (DES) to map the observing conditions of the Science Verification (SV) data. The resulting distributions and maps of sources of systematics are used in several analyses of DES–SV to perform detailed null tests with the data, and also to incorporate systematics in survey simulations. We illustrate the complementary nature of these two approaches by comparing the SV data with BCC-UFig, a synthetic sky catalog generated by forward-modeling of the DES–SV images. We analyze the BCC-UFig simulation to construct galaxy samples mimicking those used in SV galaxy clustering studies. We show that the spatially varying survey depth imprinted in the observed galaxy densities and the redshift distributions of the SV data are successfully reproduced by the simulation and are well-captured by the maps of observing conditions. The combined use of the maps, the SV data, and the BCC-UFig simulation allows us to quantify the impact of spatial systematics on N(z), the redshift distributions inferred using photometric redshifts. We conclude that spatial systematics in the SV data are mainly due to seeing fluctuations and are under control in current clustering and weak-lensing analyses. However, they will need to be carefully characterized in upcoming phases of DES in order to avoid biasing the inferred cosmological results. Finally, the framework presented here is relevant to all multi-epoch surveys and will be essential for exploiting future surveys such as the Large Synoptic Survey Telescope, which will require detailed null tests and realistic end-to-end image simulations to correctly interpret the deep, high

  15. Mapping and Simulating Systematics Due to Spatially-Varying Observing Conditions in DES Science Verification Data

    SciTech Connect

    Leistedt, B.

    2015-07-20

    Spatially-varying depth and characteristics of observing conditions, such as seeing, airmass, or sky background, are major sources of systematic uncertainties in modern galaxy survey analyses, in particular in deep multi-epoch surveys. We present a framework to extract and project these sources of systematics onto the sky, and apply it to the Dark Energy Survey (DES) to map the observing conditions of the Science Verification (SV) data. The resulting distributions and maps of sources of systematics are used in several analyses of DES SV to perform detailed null tests with the data, and also to incorporate systematics in survey simulations. We illustrate the complementarity of these two approaches by comparing the SV data with the BCC-UFig, a synthetic sky catalogue generated by forward-modelling of the DES SV images. We then analyse the BCC-UFig simulation to construct galaxy samples mimicking those used in SV galaxy clustering studies. We show that the spatially-varying survey depth imprinted in the observed galaxy densities and the redshift distributions of the SV data are successfully reproduced by the simulation and well-captured by the maps of observing conditions. The combined use of the maps, the SV data and the BCC-UFig simulation allows us to quantify the impact of spatial systematics on N(z), the redshift distributions inferred using photometric redshifts. We conclude that spatial systematics in the SV data are mainly due to seeing fluctuations and are under control in current clustering and weak lensing analyses. However, they will need to be carefully characterised in upcoming phases of DES in order to avoid biasing the inferred cosmological results. The framework presented is relevant to all multi-epoch surveys, and will be essential for exploiting future surveys such as the Large Synoptic Survey Telescope, which will require detailed null-tests and realistic end-to-end image simulations to correctly interpret the deep, high-cadence observations of the

  16. Semi-analytical solution for the generalized absorbing boundary condition in molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Lee, Chung-Shuo; Chen, Yan-Yu; Yu, Chi-Hua; Hsu, Yu-Chuan; Chen, Chuin-Shan

    2017-02-01

    We present a semi-analytical solution of a time-history kernel for the generalized absorbing boundary condition in molecular dynamics (MD) simulations. To facilitate the kernel derivation, the concept of virtual atoms in real space that can conform with an arbitrary boundary in an arbitrary lattice is adopted. The generalized Langevin equation is regularized using eigenvalue decomposition and, consequently, an analytical expression of an inverse Laplace transform is obtained. With construction of dynamical matrices in the virtual domain, a semi-analytical form of the time-history kernel functions for an arbitrary boundary in an arbitrary lattice can be found. The time-history kernel functions for different crystal lattices are derived to show the generality of the proposed method. Non-equilibrium MD simulations in a triangular lattice with and without the absorbing boundary condition are conducted to demonstrate the validity of the solution.

  17. Forty years experience in developing and using rainfall simulators under tropical and Mediterranean conditions

    NASA Astrophysics Data System (ADS)

    Pla-Sentís, Ildefonso; Nacci, Silvana

    2010-05-01

    Rainfall simulation has been used as a practical tool for evaluating the interaction of falling water drops on the soil surface, to measure both stability of soil aggregates to drop impact and water infiltration rates. In both cases it is tried to simulate the effects of natural rainfall, which usually occurs at very different, variable and erratic rates and intensities. One of the main arguments against the use of rainfall simulators is the difficulty to reproduce the size, final velocity and kinetic energy of the drops in natural rainfall. Since the early 70´s we have been developing and using different kinds of rainfall simulators, both at laboratory and field levels, and under tropical and Mediterranean soil and climate conditions, in flat and sloping lands. They have been mainly used to evaluate the relative effects of different land use and management, including different cropping systems, tillage practices, surface soil conditioning, surface covers, etc. on soil water infiltration, on runoff and on erosion. Our experience is that in any case it is impossible to reproduce the variable size distribution and terminal velocity of raindrops, and the variable changes in intensity of natural storms, under a particular climate condition. In spite of this, with the use of rainfall simulators it is possible to obtain very good information, which if it is properly interpreted in relation to each particular condition (land and crop management, rainfall characteristics, measurement conditions, etc.) may be used as one of the parameters for deducing and modelling soil water balance and soil moisture regime under different land use and management and variable climate conditions. Due to the possibility for a better control of the intensity of simulated rainfall and of the size of water drops, and the possibility to make more repeated measurements under very variable soil and land conditions, both in the laboratory and specially in the field, the better results have been

  18. Gaseous exhaust emissions from a J-58 engine at simulated supersonic flight conditions

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1974-01-01

    Emissions of total oxides of nitrogen, unburned hydrocarbons, carbon monoxide, and carbon dioxide from a J-58 engine at simulated flight conditions of Mach 2.0, 2.4, and 2.8 at 19.8 km altitude are reported. For each flight condition, measurements were made for four engine power levels from maximum power without afterburning through maximum afterburning. These measurements were made 7 cm downstream of the engine primary nozzle using a single point traversing gas sample probe. Results show that emissions vary with flight speed, engine power level, and with radial position across the exhaust.

  19. Launch Condition Deviations of Reusable Launch Vehicle Simulations in Exo-Atmospheric Zoom Climbs

    NASA Technical Reports Server (NTRS)

    Urschel, Peter H.; Cox, Timothy H.

    2003-01-01

    The Defense Advanced Research Projects Agency has proposed a two-stage system to deliver a small payload to orbit. The proposal calls for an airplane to perform an exo-atmospheric zoom climb maneuver, from which a second-stage rocket is launched carrying the payload into orbit. The NASA Dryden Flight Research Center has conducted an in-house generic simulation study to determine how accurately a human-piloted airplane can deliver a second-stage rocket to a desired exo-atmospheric launch condition. A high-performance, fighter-type, fixed-base, real-time, pilot-in-the-loop airplane simulation has been modified to perform exo-atmospheric zoom climb maneuvers. Four research pilots tracked a reference trajectory in the presence of winds, initial offsets, and degraded engine thrust to a second-stage launch condition. These launch conditions have been compared to the reference launch condition to characterize the expected deviation. At each launch condition, a speed change was applied to the second-stage rocket to insert the payload onto a transfer orbit to the desired operational orbit. The most sensitive of the test cases was the degraded thrust case, yielding second-stage launch energies that were too low to achieve the radius of the desired operational orbit. The handling qualities of the airplane, as a first-stage vehicle, have also been investigated.

  20. Effects of baseline conditions on the simulated hydrologic response to projected climate change

    USGS Publications Warehouse

    Koczot, Kathryn M.; Markstrom, Steven L.; Hay, Lauren E.

    2011-01-01

    Changes in temperature and precipitation projected from five general circulation models, using one late-twentieth-century and three twenty-first-century emission scenarios, were downscaled to three different baseline conditions. Baseline conditions are periods of measured temperature and precipitation data selected to represent twentieth-century climate. The hydrologic effects of the climate projections are evaluated using the Precipitation-Runoff Modeling System (PRMS), which is a watershed hydrology simulation model. The Almanor Catchment in the North Fork of the Feather River basin, California, is used as a case study. Differences and similarities between PRMS simulations of hydrologic components (i.e., snowpack formation and melt, evapotranspiration, and streamflow) are examined, and results indicate that the selection of a specific time period used for baseline conditions has a substantial effect on some, but not all, hydrologic variables. This effect seems to be amplified in hydrologic variables, which accumulate over time, such as soil-moisture content. Results also indicate that uncertainty related to the selection of baseline conditions should be evaluated using a range of different baseline conditions. This is particularly important for studies in basins with highly variable climate, such as the Almanor Catchment.

  1. Simulated conditions of microgravity suppress progesterone production by luteal cells of the pregnant rat

    NASA Technical Reports Server (NTRS)

    Bhat, G. K.; Yang, H.; Sridaran, R.

    2001-01-01

    The purpose of this study was to assess whether simulated conditions of microgravity induce changes in the production of progesterone by luteal cells of the pregnant rat ovary using an in vitro model system. The microgravity environment was simulated using either a high aspect ratio vessel (HARV) bioreactor with free fall or a clinostat without free fall of cells. A mixed population of luteal cells isolated from the corpora lutea of day 8 pregnant rats was attached to cytodex microcarrier beads (cytodex 3). These anchorage dependent cells were placed in equal numbers in the HARV or a spinner flask control vessel in culture conditions. It was found that HARV significantly reduced the daily production of progesterone from day 1 through day 8 compared to controls. Scanning electron microscopy showed that cells attached to the microcarrier beads throughout the duration of the experiment in both types of culture vessels. Cells cultured in chamber slide flasks and placed in a clinostat yielded similar results when compared to those in the HARV. Also, when they were stained by Oil Red-O for lipid droplets, the clinostat flasks showed a larger number of stained cells compared to control flasks at 48 h. Further, the relative amount of Oil Red-O staining per milligram of protein was found to be higher in the clinostat than in the control cells at 48 h. It is speculated that the increase in the level of lipid content in cells subjected to simulated conditions of microgravity may be due to a disruption in cholesterol transport and/or lesions in the steroidogenic pathway leading to a fall in the synthesis of progesterone. Additionally, the fall in progesterone in simulated conditions of microgravity could be due to apoptosis of luteal cells.

  2. Mechanical Properties of a Unidirectional Basalt-Fiber-Reinforced Plastic Under a Loading Simulating Operation Conditions

    NASA Astrophysics Data System (ADS)

    Lobanov, D. S.; Slovikov, S. V.

    2017-01-01

    The results of experimental investigations of unidirectional composites based on basalt fibers and different marks of epoxy resins are presented. Uniaxial tensile tests were carried out using a specimen fixation technique simulating the operation conditions of structures. The mechanical properties of the basalt-fiber-reinforced plastics (BFRPs) were determined. The diagrams of loading and deformation of BFRP specimens were obtain. The formulations of the composites with the highest mechanical properties were revealed.

  3. Simulation of flow and habitat conditions under ice, Cache la Poudre River - January 2006

    USGS Publications Warehouse

    Waddle, Terry

    2007-01-01

    The objectives of this study are (1) to describe the extent and thickness of ice cover, (2) simulate depth and velocity under ice at the study site for observed and reduced flows, and (3) to quantify fish habitat in this portion of the mainstem Cache la Poudre River for the current winter release schedule as well as for similar conditions without the 0.283 m3/s winter release.

  4. Laser spectroscopic real time measurements of methanogenic activity under simulated Martian subsurface analog conditions

    NASA Astrophysics Data System (ADS)

    Schirmack, Janosch; Böhm, Michael; Brauer, Chris; Löhmannsröben, Hans-Gerd; de Vera, Jean-Pierre; Möhlmann, Diedrich; Wagner, Dirk

    2014-08-01

    On Earth, chemolithoautothrophic and anaerobic microorganisms such as methanogenic archaea are regarded as model organisms for possible subsurface life on Mars. For this reason, the methanogenic strain Methanosarcina soligelidi (formerly called Methanosarcina spec. SMA-21), isolated from permafrost-affected soil in northeast Siberia, has been tested under Martian thermo-physical conditions. In previous studies under simulated Martian conditions, high survival rates of these microorganisms were observed. In our study we present a method to measure methane production as a first attempt to study metabolic activity of methanogenic archaea during simulated conditions approaching conditions of Mars-like environments. To determine methanogenic activity, a measurement technique which is capable to measure the produced methane concentration with high precision and with high temporal resolution is needed. Although there are several methods to detect methane, only a few fulfill all the needed requirements to work within simulated extraterrestrial environments. We have chosen laser spectroscopy, which is a non-destructive technique that measures the methane concentration without sample taking and also can be run continuously. In our simulation, we detected methane production at temperatures down to -5 °C, which would be found on Mars either temporarily in the shallow subsurface or continually in the deep subsurface. The pressure of 50 kPa which we used in our experiments, corresponds to the expected pressure in the Martian near subsurface. Our new device proved to be fully functional and the results indicate that the possible existence of methanogenic archaea in Martian subsurface habitats cannot be ruled out.

  5. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1985-01-01

    Radio absorptivity data for the Venus middle atmosphere (1 to 6 atm, temperatures from 500 to 575K) obtained from spacecraft radio occultation experiments (at 3.6 to 13.4 cm wavelengths) and earth-based radio astronomical observations (1 to 3 cm wavelength range) are compared to laboratory observations at the latter wavelength range under simulated Venus conditions to infer abundances of microwave-absorbing atmospheric constituents, i.e. H2SO4 in a CO2 atmosphere.

  6. Simulation-based education for building clinical teams

    PubMed Central

    Marshall, Stuart D; Flanagan, Brendan

    2010-01-01

    Failure to work as an effective team is commonly cited as a cause of adverse events and errors in emergency medicine. Until recently, individual knowledge and skills in managing emergencies were taught, without reference to the additional skills required to work as part of a team. Team training courses are now becoming commonplace, however their strategies and modes of delivery are varied. Just as different delivery methods of traditional education can result in different levels of retention and transfer to the real world, the same is true in team training of the material in different ways in traditional forms of education may lead to different levels of retention and transfer to the real world, the same is true in team training. As team training becomes more widespread, the effectiveness of different modes of delivery including the role of simulation-based education needs to be clearly understood. This review examines the basis of team working in emergency medicine, and the components of an effective emergency medical team. Lessons from other domains with more experience in team training are discussed, as well as the variations from these settings that can be observed in medical contexts. Methods and strategies for team training are listed, and experiences in other health care settings as well as emergency medicine are assessed. Finally, best practice guidelines for the development of team training programs in emergency medicine are presented. PMID:21063559

  7. Properties of Lactobacillus reuteri chitosan-calcium-alginate encapsulation under simulated gastrointestinal conditions.

    PubMed

    Huang, Hui-Ying; Tang, Yi-Ju; King, V An-Erl; Chou, Jen-Wei; Tsen, Jen-Horng

    2015-03-01

    The protective effects of encapsulation on the survival of Lactobacillus reuteri and the retention of the bacterium's probiotic properties under simulated gastrointestinal conditions were investigated. Viable counts and the remaining probiotic properties of calcium (Ca)-alginate encapsulated (A group), chitosan-Ca-alginate encapsulated (CA group), and unencapsulated, free L. reuteri (F group) were determined. Encapsulation improved the survival of L. reuteri subjected to simulated gastrointestinal conditions, with the greatest protective effect achieved in the CA group. The degree of cell membrane injury increased with increasing bile salt concentrations at constant pH, but the extent of injury was less in the encapsulated than in the free cells. Adherence rates were, in descending order: CA (0.524%)>A (0.360%)>F (0.275%). Lactobacillus reuteri cells retained their antagonistic activity toward Listeria monocytogenes even after incubation of the lactobacilli under simulated gastrointestinal conditions. Displacement of the pathogen by cells released from either of the encapsulation matrices was higher than that by free cells. The safety of L. reuteri was demonstrated in an in vitro invasion assay.

  8. Direct numerical simulation of turbulent flows over superhydrophobic surfaces with gas pockets using linearized boundary conditions

    NASA Astrophysics Data System (ADS)

    Seo, Jongmin; Bose, Sanjeeb; Garcia-Mayoral, Ricardo; Mani, Ali

    2012-11-01

    Superhydrophobic surfaces are shown to be effective for surface drag reduction under laminar regime by both experiments and simulations (see for example, Ou and Rothstein, Phys. Fluids 17:103606, 2005). However, such drag reduction for fully developed turbulent flow maintaining the Cassie-Baxter state remains an open problem due to high shear rates and flow unsteadiness of turbulent boundary layer. Our work aims to develop an understanding of mechanisms leading to interface breaking and loss of gas pockets due to interactions with turbulent boundary layers. We take advantage of direct numerical simulation of turbulence with slip and no-slip patterned boundary conditions mimicking the superhydrophobic surface. In addition, we capture the dynamics of gas-water interface, by deriving a proper linearized boundary condition taking into account the surface tension of the interface and kinematic matching of interface deformation and normal velocity conditions on the wall. We will show results from our simulations predicting the dynamical behavior of gas pocket interfaces over a wide range of dimensionless surface tensions. Supported by the Office of Naval Research and the Kwanjeong Educational Scholarship Foundation.

  9. [Heat and moisture exchangers for conditioning of inspired air of intubated patients in intensive care. The humidification properties of passive air exchangers under clinical conditions].

    PubMed

    Rathgeber, J; Züchner, K; Kietzmann, D; Weyland, W

    1995-04-01

    Heat and moisture exchangers (HME) are used as artificial noses for intubated patients to prevent tracheo-bronchial or pulmonary damage resulting from dry and cold inspired gases. HME are mounted directly on the tracheal tube, where they collect a large fraction of the heat and moisture of the expired air, adding this to the subsequent inspired breath. The effective performance depends on the water-retention capacity of the HME: the amount of water added to the inspired gas cannot exceed the stored water uptake of the previous breath. This study evaluates the efficiency of four different HME under laboratory and clinical conditions using a new moisture-measuring device. METHODS. In a first step, the absolute efficiency of four different HME (DAR Hygrobac, Gibeck Humid-Vent 2P, Pall BB 22-15 T, and Pall BB 100) was evaluated using a lung model simulating physiological heat and humidity conditions of the upper airways. The model was ventilated with tidal volumes of 500, 1,000, and 1,500 ml and different flow rates. The water content of the ventilated air was determined between tracheal tube and HME using a new high-resolution humidity meter and compared with the absolute water loss of the exhaled air at the gas outlet of a Siemens Servo C ventilator measured with a dew-point hygrometer. Secondly, the moisturizing efficiency was evaluated under clinical conditions in an intensive care unit with 25 intubated patients. Maintaining the ventilatory conditions for each patient, the HME were randomly changed. The humidity data were determined as described above and compared with the laboratory findings. RESULTS AND DISCUSSION. The water content at the respirator outlet is inversely equivalent to the humidity of the inspired gases and represents the water loss from the respiratory tract if the patient is ventilated with dry gases. Moisture retention and heating capacity decreased with higher volumes and higher flow rates. These data are simple to obtain without affecting the

  10. Web-Based Immersive Virtual Patient Simulators: Positive Effect on Clinical Reasoning in Medical Education

    PubMed Central

    Heiermann, Nadine; Plum, Patrick Sven; Wahba, Roger; Chang, De-Hua; Maus, Martin; Chon, Seung-Hun; Hoelscher, Arnulf H; Stippel, Dirk Ludger

    2015-01-01

    Background Clinical reasoning is based on the declarative and procedural knowledge of workflows in clinical medicine. Educational approaches such as problem-based learning or mannequin simulators support learning of procedural knowledge. Immersive patient simulators (IPSs) go one step further as they allow an illusionary immersion into a synthetic world. Students can freely navigate an avatar through a three-dimensional environment, interact with the virtual surroundings, and treat virtual patients. By playful learning with IPS, medical workflows can be repetitively trained and internalized. As there are only a few university-driven IPS with a profound amount of medical knowledge available, we developed a university-based IPS framework. Our simulator is free to use and combines a high degree of immersion with in-depth medical content. By adding disease-specific content modules, the simulator framework can be expanded depending on the curricular demands. However, these new educational tools compete with the traditional teaching Objective It was our aim to develop an educational content module that teaches clinical and therapeutic workflows in surgical oncology. Furthermore, we wanted to examine how the use of this module affects student performance. Methods The new module was based on the declarative and procedural learning targets of the official German medical examination regulations. The module was added to our custom-made IPS named ALICE (Artificial Learning Interface for Clinical Education). ALICE was evaluated on 62 third-year students. Results Students showed a high degree of motivation when using the simulator as most of them had fun using it. ALICE showed positive impact on clinical reasoning as there was a significant improvement in determining the correct therapy after using the simulator. ALICE positively impacted the rise in declarative knowledge as there was improvement in answering multiple-choice questions before and after simulator use. Conclusions

  11. Significance of frailty for predicting adverse clinical outcomes in different patient groups with specific medical conditions.

    PubMed

    Ritt, Martin; Gaßmann, Karl-Günter; Sieber, Cornel Christian

    2016-10-01

    Frailty is a major health burden in an aging society. It constitutes a clinical state of reduced physiological reserves that is associated with a diminished ability to withstand internal and external stressors. Frail patients have an increased risk for adverse clinical outcomes, such as mortality, readmission to hospital, institutionalization and falls. Of further clinical interest, frailty might be at least in part reversible in some patients and subject to preventive strategies. In daily clinical practice older patients with a complex health status, who are mostly frail or at least at risk of developing frailty, are frequently cared for by geriatricians. Recently, clinicians and scientists from other medical disciplines, such as cardiology, pulmonology, gastroenterology, nephrology, endocrinology, rheumatology, surgery and critical care medicine also discovered frailty to be an interesting instrument for risk stratification of patients, including younger patients. In this review we highlight the results of recent studies that demonstrated the significance of frailty to predict adverse clinical outcomes in patients with specific medical conditions, such as cardiac, lung, liver and kidney diseases as well as diabetes mellitus, osteoarthritis, trauma patients, patients undergoing surgery and critically ill patients. Multiple studies in patients with the aforementioned specific medical conditions could be identified demonstrating a predictive role of frailty for several adverse clinical outcomes. The association between frailty and adverse clinical outcomes reported in these studies was in part independent of several major potential confounder factors, such as age, sex, race, comorbidities and disabilities and were also detected in younger patients.

  12. Time Accurate Unsteady Pressure Loads Simulated for the Space Launch System at a Wind Tunnel Condition

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.; Brauckmann, Gregory J.; Kleb, Bil; Streett, Craig L; Glass, Christopher E.; Schuster, David M.

    2015-01-01

    Using the Fully Unstructured Three-Dimensional (FUN3D) computational fluid dynamics code, an unsteady, time-accurate flow field about a Space Launch System configuration was simulated at a transonic wind tunnel condition (Mach = 0.9). Delayed detached eddy simulation combined with Reynolds Averaged Naiver-Stokes and a Spallart-Almaras turbulence model were employed for the simulation. Second order accurate time evolution scheme was used to simulate the flow field, with a minimum of 0.2 seconds of simulated time to as much as 1.4 seconds. Data was collected at 480 pressure taps at locations, 139 of which matched a 3% wind tunnel model, tested in the Transonic Dynamic Tunnel (TDT) facility at NASA Langley Research Center. Comparisons between computation and experiment showed agreement within 5% in terms of location for peak RMS levels, and 20% for frequency and magnitude of power spectral densities. Grid resolution and time step sensitivity studies were performed to identify methods for improved accuracy comparisons to wind tunnel data. With limited computational resources, accurate trends for reduced vibratory loads on the vehicle were observed. Exploratory methods such as determining minimized computed errors based on CFL number and sub-iterations, as well as evaluating frequency content of the unsteady pressures and evaluation of oscillatory shock structures were used in this study to enhance computational efficiency and solution accuracy. These techniques enabled development of a set of best practices, for the evaluation of future flight vehicle designs in terms of vibratory loads.

  13. Impact of Uncertainty of Boundary Conditions on Simulations of the Last Millennium

    NASA Astrophysics Data System (ADS)

    LeGrande, A. N.; Tsigaridis, K.

    2014-12-01

    Goddard Institute for Space Studies (GISS)-E2-R sampled the broadest range of boundary conditions for simulations of the last millennium, with a dozen different experiments sampling three different volcanic forcing scenarios, three anthropogenic land use change scenarios, and three different solar (TSI) scenarios. This suite of experiment yields 15,000 years of simulations for the last millennium. Here the forcings of these experiments are distilled down into basic fingerprints of each type of change - volcanic, solar, and, anthropogenic land use - to test whether it is feasible to detect these climate changes in various proxy archives. I will illustrate the difficulty in the detection of any of these changes in individual proxy archives, and establish the minimum critieria (given a perfect simulation) to identify solar minima, volcanic eruptions, and large changes in land use. Further, preliminary new results to illustrate the impact of various degrees of sophistication in applying volcanic forcing on the resultant climate signal will be presented. We will also study the impact of atmospheric composition on climate, by presenting results from atmosphere-only model simulations with the GISS-E2 model, which includes interactive gas-phase chemistry and aerosols at decadal-scale time slices, driven by the millennial-length coupled atmosphere-ocean simulations.

  14. Survival of Bacillus pumilus SAFR-032 in simulated Mars atmosphere in real space conditions

    NASA Astrophysics Data System (ADS)

    Vaishampayan, Parag A.; Fox, George E.; Venkateswaran, Kasthuri

    2010-09-01

    To prevent forward contamination and maintain the scientific integrity of future life detection missions, it is important to characterize and attempt to eliminate terrestrial microorganisms associated with exploratory spacecraft and landing vehicles. Among the organisms isolated from spacecraft-associated habitats, spores of Bacillus pumilus SAFR-032 exhibited unusually high resistance to decontamination techniques such as UVradiation and peroxide treatment. Subsequently, Bacillus pumilus SAFR-032 was flown to the International Space Station (ISS) and exposed to a variety of space conditions using the European Technology Exposure Platform and Experiment Facility (EuTEF). After 18 months exposure in the EuTEF facility under dark space conditions, SAFR-032 spores showed 10 to 40% survivability, whereas a survival rate of 85 to 100% was observed when these spores were kept aboard the ISS under dark simulated-Mars atmospheric conditions. In contrast, when UV (>110nm) was exerted on SAFR-032 spores for the same time period and conditions using the EuTEF, a ~7-log reduction in viability was noticed. However, the UV exposure still did not inactivate all the spores as 19 CFUs were later isolated via cultivation. A parallel experiment was conducted on Earth with identical samples but under simulated conditions. Spores exposed to ground simulations showed less of a reduction in viability when compared with the "real space" exposed spores (~3-log reduction in viability for Mars UV, and ~4-log reduction in viability for Space UV). The data generated is important to assess the probability and mechanisms of microbial survival, microbial contaminants of risk for forward contamination, in situ life detection, and to safeguard the integrity of sample return missions.

  15. Formation of Complex Amino Acid Precursors in Simulated Primitive Atmosphere and Their Alteration under Simulated Submarine Hydrothermal Conditions

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kensei; Kurihara, Hironari; Hirako, Tomoaki; Obayashi, Yumiko; Kaneko, Takeo; Takano, Yoshinori; Yoshimura, Yoshitaka

    Since late 1970's a great number of submarine hydrothermal systems (SHSs) has been dis-covered, and they are considered possible sites of chemical evolution and generation of life on the Earth since their discovery in late 1970s. A number of experiments simulating the con-ditions of SHSs were conducted, and abiotic production and polymerization of amino acids were reported. Free amino acids were frequently used as starting materials to examine possible organic reactions in the simulation experiments. In our early studies, not free amino acids but complex amino acids precursors with large molecular weights were formed abiotically from simulated primitive Earth atmosphere (a mixture of CO, N2 and H2 O) (Takano et al., 2004). Such complex organics (hereafter referred as to CNWs) should have been delivered to SHSs in Primitive Ocean, where they were subjected to further alteration. We examined possible alteration of the complex organics in high-temperature high-pressure environments by the su-percritical water flow reactor (SCWFR) (Islam et al.. 2003) and an autoclave. CNWs were quite hydrophilic compounds whose molecular weights were ca. 3000. After heating 573 K for 2 min in the SCWFR, aggregates of organics were formed, which were separated from aque-ous solution with a Nucleopore filter (pore size: 200 nm). We propose the following scenario of chemical evolution: (1) Complex organics including amino acid precursors were formed in primitive atmosphere and/or extraterrestrial environments, (ii) they were delivered to primor-dial SHSs, (iii) hydrothermal alteration occurred in SHSs to give organic aggregates, (iv) quite primitive molecular systems with subtle biological functions were generated in the competition among such aggregates. References: Islam, Md. N., Kaneko, T., and Kobayashi, K (2003). Reactions of Amino Acids with a Newly ConstructedSupercritical Water Flow Reactor Simulating Submarine Hydrothermal Systems. Bull. Chem. Soc. Jpn., 76, 1171. Takano, Y

  16. An unstructured direct simulation Monte Carlo methodology with Kinetic-Moment inflow and outflow boundary conditions

    NASA Astrophysics Data System (ADS)

    Gatsonis, Nikolaos A.; Chamberlin, Ryan E.; Averkin, Sergey N.

    2013-01-01

    The mathematical and computational aspects of the direct simulation Monte Carlo on unstructured tetrahedral grids (U3DSMC) with a Kinetic-Moment (KM) boundary conditions method are presented. The algorithms for particle injection, particle loading, particle motion, and particle tracking are presented. The KM method applicable to a subsonic or supersonic inflow/outflow boundary, couples kinetic (particle) U3DSMC properties with fluid (moment) properties. The KM method obtains the number density, temperature and mean velocity needed to define the equilibrium, drifting Maxwellian distribution at a boundary. The moment component of KM is based on the local one dimensional inviscid (LODI) boundary conditions method consistent with the 5-moment compressible Euler equations. The kinetic component of KM is based on U3DSMC for interior properties and the equilibrium drifting Maxwellian at the boundary. The KM method is supplemented with a time-averaging procedure, allows for choices in sampling-cell procedures, minimizes fluctuations and accelerates the convergence in subsonic flows. Collision sampling in U3DSMC implements the no-time-counter method and includes elastic and inelastic collisions. The U3DSMC with KM boundary conditions is validated and verified extensively with simulations of subsonic nitrogen flows in a cylindrical tube with imposed inlet pressure and density and imposed outlet pressure. The simulations cover the regime from slip to free-molecular with inlet Knudsen numbers between 0.183 and 18.27 and resulting inlet Mach numbers between 0.037 and 0.027. The pressure and velocity profiles from U3DSMC-KM simulations are compared with analytical solutions obtained from first-order and second-order slip boundary conditions. Mass flow rates from U3DSMC-KM are compared with validated analytical solutions for the entire Knudsen number regime considered. Error and sensitivity analysis is performed and numerical fractional errors are in agreement with theoretical

  17. Simulated pond-aquifer interactions under natural and stressed conditions near Snake Pond, Cape Cod, Massachusetts

    USGS Publications Warehouse

    Walter, Donald A.; Masterson, John P.; LeBlanc, Denis R.

    2002-01-01

    A numerical model was used to simulate pond-aquifer interactions under natural and stressed conditions near Snake Pond, Cape Cod, Massachusetts. Simulation results show that pond-bottom hydraulic conductivity, which represents the degree of hydraulic connection between the pond and the aquifer, is an important control on these interactions. As this parameter was incrementally increased from 10 to 350 feet per day, the rate of ground-water inflow into the pond under natural conditions increased by about 250 percent, the associated residence times of water in the pond decreased by about 50 percent, and ground-water inflow to the pond shifted closer to the pond shore. Most ground-water inflow (90 to 98 percent) was in the upper model layer, which corresponded to shallow, near-shore areas of the pond, over the entire range of pond-bottom hydraulic conductivity. Ground-water flow paths into the pond became more vertical, the contributing area to the pond became larger, and the pond captured water from greater depths in the aquifer as the hydraulic conductivity of the pond bottom was increased. The pond level, however, remained nearly constant, and regional ground-water levels and gradients differed little over the range of pond-bottom hydraulic conductivity, indicating that calibrated models with similar head solutions can have different pond-aquifer interaction characteristics. Hydrologic stresses caused by a simulated plume-containment system that specifies the extraction and injection of large volumes of ground water near the pond increased the pond level by about 0.4 foot and ground-water inflow rates into the pond by about 25 percent. Several factors related to the operation of the simulated containment system are affected by the hydraulic conductivity of the pond bottom. With increasing pond-bottom hydraulic conductivity, the amount of injected water that flows into Snake Pond increased and the amount of water recirculated between extraction and injection wells

  18. Evaluation of the biocompatibility of NiTi dental wires: a comparison of laboratory experiments and clinical conditions.

    PubMed

    Toker, S M; Canadinc, D

    2014-07-01

    Effects of intraoral environment on the surface degradation of nickel-titanium (NiTi) shape memory alloy orthodontic wires was simulated through ex situ static immersion experiments in artificial saliva. The tested wires were compared to companion wires retrieved from patients in terms of chemical changes and formation of new structures on the surface. Results of the ex situ experiments revealed that the acidic erosion effective at the earlier stages of immersion led to the formation of new structures as the immersion period approached 30 days. Moreover, comparison of these results with the analysis of wires utilized in clinical treatment evidenced that ex situ experiments are reliable in terms predicting C-rich structure formation on the wire surfaces. However, the formation of C pileups at the contact sites of arch wires and brackets could not be simulated with the aid of static immersion experiments, warranting the simulation of the intraoral environment in terms of both chemical and physical conditions, including mechanical loading, when evaluating the biocompatibility of NiTi orthodontic arch wires.

  19. A brief history of the development of mannequin simulators for clinical education and training

    PubMed Central

    Cooper, J; Taqueti, V

    2004-01-01

    Simulation for medical and healthcare applications, although still in a relatively nascent stage of development, already has a history that can inform the process of further research and dissemination. The development of mannequin simulators used for education, training, and research is reviewed, tracing the motivations, evolution to commercial availability, and efforts toward assessment of efficacy of those for teaching cardiopulmonary resuscitation, cardiology skills, anaesthesia clinical skills, and crisis management. A brief overview of procedural simulators and part-task trainers is also presented, contrasting the two domains and suggesting that a thorough history of the 20+ types of simulator technologies would provide a useful overview and perspective. There has been relatively little cross fertilisation of ideas and methods between the two simulator domains. Enhanced interaction between investigators and integration of simulation technologies would be beneficial for the dissemination of the concepts and their applications. PMID:15465949

  20. Conditional simulation of Thwaites Glacier bed topography for flow models: Incorporating inhomogeneous statistics and channelized morphology

    NASA Astrophysics Data System (ADS)

    Goff, J. A.; Powell, E.; Young, D. A.; Blankenship, D. D.

    2012-12-01

    Thwaites Glacier, Antarctica, is a large glacier experiencing rapid change whose mass could, if disgorged into the ocean, lead to global sea level rise on the order of 1 m. Efforts to model flow for Thwaites Glacier are strongly dependent on an accurate topographic model of the ice bed. Airborne radar data collected in 2004/5 provides 35,000 line km of bed topography measurements sampled 20 m along track on a grid survey covering much of the glacier. However, at ~15 km track spacing, this extensive data set nevertheless misses considerable important detail, particularly: (1) resolution of mesoscale channelized morphology that can guide glacier flow; and (2) resolution of small-scale roughness between the track lines that is critical for determining topographic resistance to flow. Both issues are addressed using a hybrid conditional simulation methodology that merges an unconditional stochastic realization surface with a mean surface. Channelized morphology is established in the mean surface using an algorithm developed earlier for interpolating sinuous river channels. This algorithm applies a coordinate transformation to channel picks, where the X-axis is distance along-channel, and the Y-axis is distance across-channel. Interpolation in channel space ensures along-channel continuity where interpolation in Cartesian space would not. Inverse transformation brings the interpolated channel back into Cartesian space, where a spline-in-tension interpolation completes the mean surface for areas not identified as channels. The statistical characteristics of the bed topography are modeled with an isotropic von Kármán spectrum, which specifies rms height, characteristic scale, and fractal dimension. These parameters are estimated from the data using a covariance analysis, and are determined as a function of position across the grid. RMS heights and characteristic scales are well resolved by this estimation, whereas fractal dimension is better constrained through an

  1. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    SciTech Connect

    Turner, J.P.; Hasfurther, V.

    1992-05-04

    The scope of the research program and the continuation is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 [times] 3.0 [times] 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by Rio Blanco Oil Shale Co., Inc. (RBOSC) through a separate cooperative agreement with the University of Wyoming (UW) to carry out this study. Three of the lysimeters were established at the RBOSC Tract C-a in the Piceance Basin of Colorado. Two lysimeters were established in the Environmental Simulation Laboratory (ESL) at UW. The ESL was specifically designed and constructed so that a large range of climatic conditions could be physically applied to the processed oil shale which was filled in the lysimeter cells.

  2. Enhanced desorption of persistent organic pollutants from microplastics under simulated physiological conditions.

    PubMed

    Bakir, Adil; Rowland, Steven J; Thompson, Richard C

    2014-02-01

    Microplastics have the potential to uptake and release persistent organic pollutants (POPs); however, subsequent transfer to marine organisms is poorly understood. Some models estimating transfer of sorbed contaminants to organisms neglect the role of gut surfactants under differing physiological conditions in the gut (varying pH and temperature), examined here. We investigated the potential for polyvinylchloride (PVC) and polyethylene (PE) to sorb and desorb (14)C-DDT, (14)C-phenanthrene (Phe), (14)C-perfluorooctanoic acid (PFOA) and (14)C-di-2-ethylhexyl phthalate (DEHP). Desorption rates of POPs were quantified in seawater and under simulated gut conditions. Influence of pH and temperature was examined in order to represent cold and warm blooded organisms. Desorption rates were faster with gut surfactant, with a further substantial increase under conditions simulating warm blooded organisms. Desorption under gut conditions could be up to 30 times greater than in seawater alone. Of the POP/plastic combinations examined Phe with PE gave the highest potential for transport to organisms.

  3. Gaseous exhaust emissions from a JT8D-109 turbofan engine at simulated cruise flight conditions

    NASA Technical Reports Server (NTRS)

    Diehl, L. A.; Holdeman, J. D.

    1975-01-01

    Gaseous emissions from a JT8D-109 turbofan engine were measured in an altitude facility at four simulated cruise flight conditions: Mach 0.8 at altitudes of 9.1, 10, 7, and 12.2 km and Mach 0.9 at 10.7 km. Engine inlet air temperature was held constant at 283 K for all tests. Emissions measurements were made at nominally 6 cm intervals across the horizontal diameter of the engine exhaust nozzle with a single-point traversing gas sample probe. Measured emissions of decreased with increasing altitude from an emission index of 10.4 to one of 8.3, while carbon monoxide increased with increasing altitude from an emission index of 1.6 to one of 4.4. Unburned hydrocarbon emissions were essentially negligible for all flight conditions. Since the engine inlet air temperatures were not correctly simulated, the NOx emission indices were corrected to true altitude conditions by using correlating parameters for changes in combustor inlet temperature, pressure, and temperature rise. The correction was small at the lowest altitude. At the 10.7 and 12.2 km, Mach 0.8 test conditions the correction decreased the measured values by 1 emission index.

  4. 3-D simulations to investigate initial condition effects on the growth of Rayleigh-Taylor mixing

    SciTech Connect

    Andrews, Malcolm J

    2008-01-01

    The effect of initial conditions on the growth rate of turbulent Rayleigh-Taylor (RT) mixing has been studied using carefully formulated numerical simulations. An integrated large-eddy simulation (ILES) that uses a finite-volume technique was employed to solve the three-dimensional incompressible Euler equations with numerical dissipation. The initial conditions were chosen to test the dependence of the RT growth parameters ({alpha}{sub b}, {alpha}{sub s}) on variations in (a) the spectral bandwidth, (b) the spectral shape, and (c) discrete banded spectra. Our findings support the notion that the overall growth of the RT mixing is strongly dependent on initial conditions. Variation in spectral shapes and bandwidths are found to have a complex effect of the late time development of the RT mixing layer, and raise the question of whether we can design RT transition and turbulence based on our choice of initial conditions. In addition, our results provide a useful database for the initialization and development of closures describing RT transition and turbulence.

  5. Using high-fidelity simulation to bridge clinical and classroom learning in undergraduate pediatric nursing.

    PubMed

    Darcy Mahoney, Ashley E; Hancock, Lauren E; Iorianni-Cimbak, Angela; Curley, Martha A Q

    2013-06-01

    In Patricia Benner's book, Educating Nurses: A Call for Radical Transformation, she recommends essential changes in policy, curriculum, and in the way nursing programs approach student learning. This study explored how two of Benner's key recommendations, (1) integrating the theoretical component and the clinical component and (2) moving education from an emphasis on critical thinking to an emphasis on clinical reasoning, could be achieved by integrating the use of high-fidelity patient simulation in a pediatric curriculum. Qualitative and quantitative data were collected from the group of traditional and nontraditional baccalaureate students (n=131). The quantitative data revealed learning objectives were met over 80% of the time in simulation exercises and the qualitative themes revealed a positive experience with the simulation exercises with a large proportion of students offering the sentiments that these scenarios become requirement prior to the start of clinical rotations.

  6. Application of national testing standards to simulation-based assessments of clinical palpation skills.

    PubMed

    Pugh, Carla M

    2013-10-01

    With the advent of simulation technology, several types of data acquisition methods have been used to capture hands-on clinical performance. Motion sensors, pressure sensors, and tool-tip interaction software are a few of the broad categories of approaches that have been used in simulation-based assessments. The purpose of this article is to present a focused review of 3 sensor-enabled simulations that are currently being used for patient-centered assessments of clinical palpation skills. The first part of this article provides a review of technology components, capabilities, and metrics. The second part provides a detailed discussion regarding validity evidence and implications using the Standards for Educational and Psychological Testing as an organizational and evaluative framework. Special considerations are given to content domain and creation of clinical scenarios from a developer's perspective. The broader relationship of this work to the science of touch is also considered.

  7. Flight test of an erectable spacecraft used for decelerator testing at simulated Mars entry conditions

    NASA Technical Reports Server (NTRS)

    Henning, A. B.; Lundstrom, R. R.

    1972-01-01

    A 55 foot diameter disk-gap-band parachute was deployed behind an expandable 15 foot diameter, 120 deg blunted-cone simulated spacecraft. The spacecraft was carried to altitude in the folded condition. An automatic control system kept the folded spacecraft pointing in the desired direction after booster separation. The aeroshell was then erected at the desired conditions by ground command. When the desired parachute test conditions were reached, another ground command deployed the test parachute. The test Mach number and dynamic pressure obtained at the parachute peak load were 2.62 and 19.4 pounds per square foot respectively. A large disturbance after aeroshell erection caused a large angle of attack to exist at parachute deployment. Methods of preventing this disturbance are discussed.

  8. Accuracy of the Frensley inflow boundary condition for Wigner equations in simulating resonant tunneling diodes

    SciTech Connect

    Jiang Haiyan; Cai Wei; Tsu, Raphael

    2011-03-01

    In this paper, the accuracy of the Frensley inflow boundary condition of the Wigner equation is analyzed in computing the I-V characteristics of a resonant tunneling diode (RTD). It is found that the Frensley inflow boundary condition for incoming electrons holds only exactly infinite away from the active device region and its accuracy depends on the length of contacts included in the simulation. For this study, the non-equilibrium Green's function (NEGF) with a Dirichlet to Neumann mapping boundary condition is used for comparison. The I-V characteristics of the RTD are found to agree between self-consistent NEGF and Wigner methods at low bias potentials with sufficiently large GaAs contact lengths. Finally, the relation between the negative differential conductance (NDC) of the RTD and the sizes of contact and buffer in the RTD is investigated using both methods.

  9. Use of a driving simulator to assess performance under adverse weather conditions in adults with albinism.

    PubMed

    Hofman, Gwen M; Summers, C Gail; Ward, Nicholas; Bhargava, Esha; Rakauskas, Michael E; Holleschau, Ann M

    2012-04-01

    Participants with albinism have reduced vision and nystagmus with reduced foveation times. This prospective study evaluated driving in 12 participants with albinism and 12 matched controls. Participants drove a vehicle simulator through a virtual rural course in sunny and foggy conditions. Under sunny conditions, participants with albinism showed a narrower preferred minimum safety boundary during car-following tasks than did controls, but there was no difference under foggy conditions. Their driving did not differ significantly from that of controls when approaching a stop sign or when choosing gap size between oncoming vehicles when crossing an intersection. However, when compared to control drivers, participants with albinism had a decreased minimum safety boundary for car-following that should be included in counseling regarding driving safety.

  10. Accuracy of user-friendly blood typing kits tested under simulated military field conditions.

    PubMed

    Bienek, Diane R; Charlton, David G

    2011-04-01

    Rapid user-friendly ABO-Rh blood typing kits (Eldon Home Kit 2511, ABO-Rh Combination Blood Typing Experiment Kit) were evaluated to determine their accuracy when used under simulated military field conditions and after long-term storage at various temperatures and humidities. Rates of positive tests between control groups, experimental groups, and industry standards were measured and analyzed using the Fisher's exact chi-square method to identify significant differences (p < or = 0.05). When Eldon Home Kits 2511 were used in various operational conditions, the results were comparable to those obtained with the control group and with the industry standard. The performance of the ABO-Rh Combination Blood Typing Experiment Kit was adversely affected by prolonged storage in temperatures above 37 degrees C. The diagnostic performance of commercial blood typing kits varies according to product and environmental storage conditions.

  11. Measurement of exhaust emissions from two J-58 engines at simulated supersonic cruise flight conditions

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1976-01-01

    Emissions of total oxides of nitrogen, unburned hydrocarbons, carbon monoxide, and carbon dioxide from two J-58 afterburning turbojet engines at simulated high-altitude flight conditions are reported. Test conditions included flight speeds from Mach 2 to 3 at altitudes from 16 to 23 km. For each flight condition, exhaust measurements were made for four or five power levels from maximum power without afterburning through maximum afterburning. The data show that exhaust emissions vary with flight speed, altitude, power level, and radial position across the exhaust. Oxides of nitrogen (NOX) emissions decreased with increasing altitude, and increased with increasing flight speed. NOX emission indices with afterburning were less than half the value without afterburning. Carbon monoxide and hydrocarbon emissions increased with increasing altitude, and decreased with increasing flight speed. Emissions of these species were substantially higher with afterburning than without.

  12. Simulations of a protein crystal: Explicit treatment of crystallization conditions links theory and experiment in the streptavidin-biotin complex

    PubMed Central

    Cerutti, David S.; Le Trong, Isolde; Stenkamp, Ronald E.; Lybrand, Terry P.

    2009-01-01

    A 250ns molecular dynamics simulation of the biotin-liganded streptavidin crystal lattice, including cryo-protectant molecules and crystallization salts, is compared to a 250ns simulation of the lattice solvated with pure water. The simulation using detailed crystallization conditions preserves the initial X-ray structure better than the simulation using pure water, even though the protein molecules display comparable mobility in either simulation. Atomic fluctuations computed from the simulation with crystallization conditions closely reproduce fluctuations derived from experimental temperature factors (correlation coefficient 0.88, omitting two N-terminal residues with very high experimental B-factors). In contrast, fluctuations calculated from the simulation with pure water were less accurate, particularly for two of the streptavidin loops exposed to solvent in the crystal lattice. Finally, we obtain good agreement between the water and cryo-protectant densities obtained from the simulated crystallization conditions and the electron density due to solvent molecules in the X-ray structure. Our results suggest that detailed lattice simulations with realistic crystallization conditions can be used to assess potential function parameters, validate simulation protocols, and obtain valuable insights that solution-phase simulations do not easily provide. We anticipate that this will prove to be a powerful strategy for molecular dynamics simulations of biomolecules. PMID:18950193

  13. Modeling access, cost, and perceived quality: computer simulation benefits orthodontic clinic staffing decisions.

    PubMed

    Montgomery, J B; LaFrancois, G G; Perry, M J

    2000-02-01

    Given limited financial resources, simulation permits a financial analysis of the optimum staffing levels for orthodontists and dental assistants in an orthodontic clinic. A computer simulation provides the information for managerial review. This study, by building a computer simulation of an orthodontic service, set out to determine the most efficient mix between providers and support staff to maximize access, maximize perceived quality, and minimize expenditures. Six combinations of providers and support staff were compared during an animated, computer-generated what-if analysis. Based on the clinic workload and size, on the cost per patient, and on the cost per quality point, the research team recommended a staffing mix of one orthodontist and three assistants. This study shows that computer simulation is an enormous asset as a decision support tool for management.

  14. A Review of the Evidence for Overlap between Urological and Non-urological Unexplained Clinical Conditions

    PubMed Central

    Rodríguez, María Ángeles Bullones; Afari, Niloofar; Buchwald, Dedra

    2010-01-01

    Purpose Unexplained clinical conditions share common features, such as pain, fatigue, disability out of proportion to physical examination findings, inconsistent laboratory abnormalities, and an association with stress and psychosocial factors. In this literature review, we examine the extent of the overlap among urological and non-urological unexplained clinical conditions characterized by pain, note the limitations of previous research, and suggest several possible explanatory models. Materials & Methods Using hallmark symptoms and syndromes as search terms, a search of 12 databases identified 1,037 full-length published articles in 8 languages from 1966 to April, 2008. The search focused on the overlap of chronic pelvic pain, interstitial cystitis, painful bladder syndrome, chronic prostatitis/chronic pelvic pain syndrome, or vulvodynia, with fibromyalgia, chronic fatigue syndrome, temporomandibular disorder, or irritable bowel syndrome. Information on authorship, type of case and control groups, eligibility criteria, case definitions, study methods, and major findings were abstracted. Results The literature suggests considerable comorbidity between urological and non-urological unexplained clinical conditions. The most robust evidence for overlap was for irritable bowel syndrome and urological unexplained syndromes, with some estimates of up to 79% comorbidity between chronic pelvic pain and symptoms of irritable bowel syndrome. However, most studies were limited by methodological problems, such as varying case definitions and selection of control subjects. Conclusions Overlap between urological and selected non-urological unexplained clinical conditions is substantial. Future research should focus on using standardized definitions and rigorously designed and well-controlled studies to further assess comorbidity, clarify the magnitude of the association, and examine common pathophysiological mechanisms. PMID:19758633

  15. Implementation of Shifted Periodic Boundary Conditions in the Large-Scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) Software

    DTIC Science & Technology

    2015-08-01

    Atomic /Molecular Massively Parallel Simulator (LAMMPS) Software by N Scott Weingarten and James P Larentzos Approved for...0687 ● AUG 2015 US Army Research Laboratory Implementation of Shifted Periodic Boundary Conditions in the Large-Scale Atomic /Molecular...Shifted Periodic Boundary Conditions in the Large-Scale Atomic /Molecular Massively Parallel Simulator (LAMMPS) Software 5a. CONTRACT NUMBER 5b

  16. Effect of different wall boundary conditions on the numerical simulation of bubbling fluidized beds

    NASA Astrophysics Data System (ADS)

    Haghgoo, Mohammad Reza; Bergstrom, Donald J.; Spiteri, Raymond J.

    2015-11-01

    There are distinct wall boundary conditions proposed in the literature for the particulate phase in the context of a continuum description of gas-particle flows. It is not yet clear how these different wall boundary conditions affect the simulated flow behavior, nor is it clear which are the most realistic. To investigate this issue, an Eulerian-Eulerian two-fluid model was used to investigate the effect of different particle-phase wall boundary conditions on the numerical prediction of bubbling/slugging gas-particle fluidized beds. Because the bed dynamics are strongly influenced by the motion of the bubbles, the impact of wall boundary conditions on the bubble statistics was examined specifically. In addition, the averaged field variables, such as the particle velocity, were compared to published experimental measurements. The comparison shows good agreement between the numerical results, generated by the Mfix code, and their experimental counterparts. It is found that the particle wall boundary condition does play a significant role in predicting the flow behavior. However, it appears that the influence of the wall boundary conditions is more significant for the instantaneous flow variables and bubble statistics than for the averaged quantities.

  17. Numerical simulation of diurnally varying thermal environment in a street canyon under haze-fog conditions

    NASA Astrophysics Data System (ADS)

    Tan, Zijing; Dong, Jingliang; Xiao, Yimin; Tu, Jiyuan

    2015-10-01

    The impact of haze-fog on surface temperature, flow pattern, pollutant dispersion and pedestrian thermal comfort are investigated using computational fluid dynamics (CFD) approach based on a three-dimensional street canyon model under different haze-fog conditions. In this study, light extinction coefficient (Kex) is adopted to represent haze-fog pollution level. Numerical simulations are performed for different Kex values at four representative time events (1000 LST, 1300 LST, 1600 LST and 2000 LST). The numerical results suggest that the surface temperature is strongly affected by the haze-fog condition. Surface heating induced by the solar radiation is enhanced by haze-fog, as higher surface temperature is observed under thicker haze-fog condition. Moreover, the temperature difference between sunlit and shadow surfaces is reduced, while that for the two shadow surfaces is slightly increased. Therefore, the surface temperature among street canyon facets becomes more evenly distributed under heavy haze-fog conditions. In addition, flow patterns are considerably altered by different haze-fog conditions, especially for the afternoon (1600 LST) case, in which thermal-driven flow has opposite direction as that of the wind-driven flow direction. Consequently, pollutants such as vehicular emissions will accumulate at pedestrian level, and pedestrian thermal comfort may lower under thicker haze-fog condition.

  18. Physiological behaviour of gliotoxigenic Aspergillus fumigatus sensu stricto isolated from maize silage under simulated environmental conditions.

    PubMed

    Alonso, V; Vergara, L Díaz; Aminahuel, C; Pereyra, C; Pena, G; Torres, A; Dalcero, A; Cavaglieri, L

    2015-01-01

    Environmental conditions play a key role in fungal development. During the silage production process, humidity, oxygen availability and pH vary among lactic-fermentation phases and among different silage sections. The aim of this work was to study the physiological behaviour of gliotoxicogenic Aspergillus fumigatus strains isolated from maize silage under simulated natural physicochemical conditions - different water activities (a(W)), temperatures (Tº), pH and oxygen pressure - on the growth parameters (growth rate and lag phase) and gliotoxin production. The silage was made with the harvested whole maize plant that was chopped and used for trench-type silo fabrication. Water activity and pH of the silage samples were determined. Total fungal counts were performed on Dichloran Rose Bengal Chloramphenicol agar and Dichloran 18% Glycerol agar. The morphological identification of A. fumigatus was performed with different culture media and at different growth temperature to observe microscopic and macroscopic characteristics. Gliotoxin production by A. fumigatus was determined by HPLC. All strains isolated were morphologically identified as A. fumigatus. Two A. fumigatus strains isolated from the silage samples were selected for the ecophysiological study (A. fumigatus sensu stricto RC031 and RC032). The results of this investigation showed that the fungus grows in the simulated natural physicochemical conditions of corn silage and produces gliotoxin. The study of the physiological behaviour of gliotoxigenic A. fumigatus under simulated environmental conditions allowed its behaviour to be predicted in silage and this will in future enable appropriate control strategies to be developed to prevent the spread of this fungus and toxin production that leads to impairment and reduced quality of silage.

  19. Physiological Responses and Performance Analysis Difference between Official and Simulated Karate Combat Conditions

    PubMed Central

    Chaabène, Helmi; Mkaouer, Bessem; Franchini, Emerson; Souissi, Nafaa; Selmi, Mohamed Amine; Nagra, Yassine; Chamari, Karim

    2013-01-01

    Purpose This study aimed to compare physiological responses and time-motion analysis between official and simulated karate combat. Methods Ten high-level karatekas participated in this study, which included official and simulated karate combat. Results Karatekas used more upper-limb attack techniques during official combat compared to simulated ones (6±3 vs 3±1; P=0.05, respectively). For official and simulated karate matches, the numbers of high-intensity actions (i.e. offensive and defensive fighting activity) were 14±6 and 18±5, respectively (P>0.05), lasting from <1s to 5s each. Total fighting activity phase was lower during official compared to simulated matches (21.0±8.2s vs 30.4±9.9s, P<0.01, respectively). Effort (10.0±2.8s) to rest (11.9±2.7s) ratio (E:R) was 1:1 and high-intensity actions (1.6±0.3s) to rest (11.9±2.7s) ratio was higher than 1:7 during simulated combat. During official karate match, the activity and rest duration were 10.0±3.4s and 16.2±4.1s, respectively (E:R ratio 1:1.5), while high-intensity actions were 1.5±0.3s, resulting in an E:R ratio of 1:11. Blood lactate concentration was higher during official (11.14±1.82 mmol.l-1) compared to simulated karate combat (7.80±2.66 mmol.l-1) (P<0.05). Subjective perceived exertion differed significantly between official and simulated combat (14±2 vs. 12±2; P<0.05, respectively). The majority of karatekas’ perceived exertion was higher in the lower limb muscle groups irrespective of the karate combat condition. Conclusion Official and simulated matches differ considerably, therefore coaches should create new strategies during training sessions to achieve the same effort and pause profile of competitive matches and/or that athletes should be submitted to frequent competitions to adapt themselves to the profile of this event. PMID:24868428

  20. Simulation of Deep Water Renewal in Crater Lake, Oregon, USA under Current and Future Climate Conditions

    NASA Astrophysics Data System (ADS)

    Piccolroaz, S.; Wood, T. M.; Wherry, S.; Girdner, S.

    2015-12-01

    We applied a 1-dimensional lake model developed to simulate deep mixing related to thermobaric instabilities in temperate lakes to Crater Lake, a 590-m deep caldera lake in Oregon's Cascade Range known for its stunning deep blue color and extremely clear water, in order to determine the frequency of deep water renewal in future climate conditions. The lake model was calibrated with 6 years of water temperature profiles, and then simulated 10 years of validation data with an RMSE ranging from 0.81°C at 50 m depth to 0.04°C at 350-460 m depth. The simulated time series of heat content in the deep lake accurately captured extreme years characterized by weak and strong deep water renewal. The lake model uses wind speed and lake surface temperature (LST) as boundary conditions. LST projections under six climate scenarios from the CMIP5 intermodel comparison project (2 representative concentration pathways X 3 general circulation models) were evaluated with air2water, a simple lumped model that only requires daily values of downscaled air temperature. air2water was calibrated with data from 1993-2011, resulting in a RMSE between simulated and observed daily LST values of 0.68°C. All future climate scenarios project increased water temperature throughout the water column and a substantive reduction in the frequency of deepwater renewal events. The least extreme scenario (CNRM-CM5, RCP4.5) projects the frequency of deepwater renewal events to decrease from about 1 in 2 years in the present to about 1 in 3 years by 2100. The most extreme scenario (HadGEM2-ES, RCP8.5) projects the frequency of deepwater renewal events to be less than 1 in 7 years by 2100 and lake surface temperatures never cooling to less than 4°C after 2050. In all RCP4.5 simulations the temperature of the entire water column is greater than 4°C for increasing periods of time. In the RCP8.5 simulations, the temperature of the entire water column is greater than 4°C year round by the year 2060 (HadGEM2

  1. Use of the human patient simulator to teach clinical judgment skills in a baccalaureate nursing program.

    PubMed

    Rhodes, Mattie L; Curran, Cynthia

    2005-01-01

    Nurse educators are finding it increasingly more challenging to prepare undergraduate students for the ever-changing and more acute clinical environment. As an answer to this dilemma, the human patient simulator can provide students with the opportunity to enhance knowledge, to facilitate skill acquisition, to decrease anxiety, and to promote clinical judgment in a safe environment. These experiences assist the novice nursing student to progress to the advanced beginner stage of practice. This article describes how faculty used the human patient simulator in creating a case scenario that enhanced critical thinking in senior nursing students.

  2. Enhancing clinical practice and education with high-fidelity human patient simulators.

    PubMed

    Peteani, Leigh Ann

    2004-01-01

    Research shows that students exhibit increased autonomy and self-confidence when delivering patient care after practicing first with high-fidelity human patient simulators (HPS). Practicing clinical skills on a high-fidelity HPS allows students to learn in a highly adaptable, safe educational environment that fosters autonomy, independence, and the development of sound analytical skills. The author discusses the use of patient simulators in nursing education, a definition of a high-fidelity HPS, and their value to clinical practice and education. A cost-effective example of how to acquire a high-fidelity HPS without going over budget is provided.

  3. Evaluation of a clinical simulation-based assessment method for EHR-platforms.

    PubMed

    Jensen, Sanne; Rasmussen, Stine Loft; Lyng, Karen Marie

    2014-01-01

    In a procurement process assessment of issues like human factors and interaction between technology and end-users can be challenging. In a large public procurement of an Electronic health record-platform (EHR-platform) in Denmark a clinical simulation-based method for assessing and comparing human factor issues was developed and evaluated. This paper describes the evaluation of the method, its advantages and disadvantages. Our findings showed that clinical simulation is beneficial for assessing user satisfaction, usefulness and patient safety, all though it is resource demanding. The method made it possible to assess qualitative topics during the procurement and it provides an excellent ground for user involvement.

  4. Spatial Estimation, Data Assimilation and Stochastic Conditional Simulation using the Counterpropagation Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Besaw, L. E.; Rizzo, D. M.; Boitnoitt, G. N.

    2006-12-01

    Accurate, yet cost effective, sites characterization and analysis of uncertainty are the first steps in remediation efforts at sites with subsurface contamination. From the time of source identification to the monitoring and assessment of a remediation design, the management objectives change, resulting in increased costs and the need for additional data acquisition. Parameter estimation is a key component in reliable site characterization, contaminant flow and transport predictions, plume delineation and many other data management goals. We implement a data-driven parameter estimation technique using a counterpropagation Artificial Neural Network (ANN) that is able to incorporate multiple types of data. This method is applied to estimates of geophysical properties measured on a slab of Berea sandstone and delineation of the leachate plume migrating from a landfill in upstate N.Y. The estimates generated by the ANN have been found to be statistically similar to estimates generated using conventional geostatistical kriging methods. The associated parameter uncertainty in site characterization, due to sparsely distributed samples (spatial or temporal) and incomplete site knowledge, is of major concern in resource mining and environmental engineering. We also illustrate the ability of the ANN method to perform conditional simulation using the spatial structure of parameters identified with semi-variogram analysis. This method allows for the generation of simulations that respect the observed measurement data, as well as the data's underlying spatial structure. The method of conditional simulation is used in a 3-dimensional application to estimate the uncertainty of soil lithology.

  5. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1991-01-01

    Laboratory measurements of microwave and millimeter wave properties of the simulated atmosphere of the outer planets and their satellites has continued. One of the focuses is on the development of a radiative transfer model of the Jovian atmosphere at wavelengths from 1 mm to 10 cm. This modeling effort led to laboratory measurements of the millimeter wave opacity of hydrogen sulfide (H2S) under simulated Jovian conditions. Descriptions of the modeling effort, the Laboratory experiment, and the observations are presented. Correlative studies of measurements with Pioneer-Venus radio occultation measurements with longer wavelength emission measurements have provided new ways for characterizing temporal and spatial variations in the abundance of both gases H2SO4 and SO2, and for modeling their roles in the subcloud atmosphere. Laboratory measurements were conducted on 1.35 cm (and 13 cm) opacity of gaseous SO2 and absorptivity of gaseous SO2 at the 3.2 mm wavelength under simulated Venus conditions. Laboratory measurements were completed on millimeter wave dielectric properties of liquid H2SO4, in order to model the effects of the opacity of the clouds of Venus onto millimeter wave emission spectrum.

  6. Aging and the detection of imminent collisions under simulated fog conditions.

    PubMed

    Ni, Rui; Bian, Zheng; Guindon, Amy; Andersen, George J

    2012-11-01

    The present study examined age-related differences in collision detection performance when contrast of the driving scene was reduced by simulated fog. Older and younger drivers were presented with a collision detection scenario in a simulator in which an object moved at a constant speed on a linear trajectory towards the driver. Drivers were shown part of the motion path of an approaching object that would eventually either collide with or pass by the driver and were required to determine whether or not the object would collide with the driver. Driver motion was either stationary or moving along a linear path down the roadway. A no fog condition and three different levels of fog were examined. Detection performance decreased when dense fog was simulated for older but not for younger observers. An age-related decrement was also found with shorter display durations (longer time to contact). When the vehicle was moving decrements in performance were observed for both younger and older drivers. These results suggest that under inclement weather conditions with reduced visibility, such as fog, older drivers may have an increased crash risk due to a decreased ability to detect impending collision events.

  7. Computational Tools for Simulating Thermal-hydrological-chemical Conditions in the Martian Subsurface

    NASA Astrophysics Data System (ADS)

    Painter, S.; Boice, D.; Browning, L.; Dinwiddie, C.; Pickett, D.

    2002-09-01

    Methods for simulating non-isothermal, multiphase flow and geochemical transport in unsaturated porous media have matured in recent years, and are now used in a range of advanced terrestrial applications. Similar computational tools have a range of potential applications in Mars research. They may be used, for example, to support data analysis, to test hypotheses regarding the evolution and current state of subsurface hydrological systems, and to understand the potential for undesirable perturbations during future drilling or sample collection activities. We describe ongoing efforts to adapt computational hydrology tools to the conditions of the Martian subsurface in a new simulation code MARSFLO. Initial versions of MARSFLO will simulate heat transport, the dynamics of multiple fluid phases (ice, water, water vapor, and CO2), and the evolution of solute concentration in the absence of geochemical reactions. The general modeling strategy is to use equilibrium constraints to reduce the system to four highly non-linear coupled conservation equations, which are then solved using an integral-finite-difference method and fully implicit time stepping. The required constitutive relationships are developed from the theory of freezing terrestrial soils and modified for Martian conditions. Data needs, potential applications, and plans to include multi-component reactive transport are also discussed. This work was funded by the Southwest Research Initiative on Mars (SwIM).

  8. Experimental verification of boundary conditions for numerical simulation of airflow in a benchmark ventilation channel

    NASA Astrophysics Data System (ADS)

    Lizal, Frantisek; Niedoba, Pavel; Seda, Libor; Jedelsky, Jan; Jicha, Miroslav

    2016-03-01

    Correct definition of boundary conditions is crucial for the appropriate simulation of a flow. It is a common practice that simulation of sufficiently long upstream entrance section is performed instead of experimental investigation of the actual conditions at the boundary of the examined area, in the case that the measurement is either impossible or extremely demanding. We focused on the case of a benchmark channel with ventilation outlet, which models a regular automotive ventilation system. At first, measurements of air velocity and turbulence intensity were performed at the boundary of the examined area, i.e. in the rectangular channel 272.5 mm upstream the ventilation outlet. Then, the experimentally acquired results were compared with results obtained by numerical simulation of further upstream entrance section defined according to generally approved theoretical suggestions. The comparison showed that despite the simple geometry and general agreement of average axial velocity, certain difference was found in the shape of the velocity profile. The difference was attributed to the simplifications of the numerical model and the isotropic turbulence assumption of the used turbulence model. The appropriate recommendations were stated for the future work.

  9. Use of Simulation to Study Nurses' Acceptance and Nonacceptance of Clinical Decision Support Suggestions.

    PubMed

    Sousa, Vanessa E C; Lopez, Karen Dunn; Febretti, Alessandro; Stifter, Janet; Yao, Yingwei; Johnson, Andrew; Wilkie, Diana J; Keenan, Gail M

    2015-10-01

    Our long-term goal was to ensure nurse clinical decision support works as intended before full deployment in clinical practice. As part of a broader effort, this pilot project explored factors influencing acceptance/nonacceptance of eight clinical decision support suggestions displayed in an electronic health record-based nursing plan of care software prototype. A diverse sample of 21 nurses participated in this high-fidelity clinical simulation experience and completed a questionnaire to assess reasons for accepting/not accepting the clinical decision support suggestions. Of 168 total suggestions displayed during the experiment (eight for each of the 21 nurses), 123 (73.2%) were accepted, and 45 (26.8%) were not accepted. The mode number of acceptances by nurses was seven of eight, with only two of 21 nurses accepting all. The main reason for clinical decision support acceptance was the nurse's belief that the suggestions were good for the patient (100%), with other features providing secondary reinforcement. Reasons for nonacceptance were less clear, with fewer than half of the subjects indicating low confidence in the evidence. This study provides preliminary evidence that high-quality simulation and targeted questionnaires about specific clinical decision support selections offer a cost-effective means for testing before full deployment in clinical practice.

  10. [Main manifestations of the phenomenon of remote post-conditioning of the heart. Clinical application of post-conditioning].

    PubMed

    Maslov, L N

    It was determined that remote post-conditioning (RP) exerts infarction-limiting and antiapoptotic effects. The infarction-limiting effect of RP is associated with enhancement of autophagia of cardiomyocytes. It was determined that RP may be an effective method of preventing reperfusion contractile dysfunction of the heart. The problem of whether RP exerts an antiarrhythmic effect in cardiac ischaemia-reperfusion remains unsolved as yet. Limitation of leukocytic invasion may have direct relation to the cardioprotector effect of RP. Decreasing the level of anti-inflammatory cytokines and MCP-1 chemokine may contribute to limitation of leukocytic infiltration into the reperfusion zone. It was determined that RP provides a decrease in intensity of lipid peroxidation. Remote postconditioning prevents reperfusion damage to cardiomyocytes both in children and adults, but RP does not improve the clinical course of the postoperative period in patients with coronary bypass grafting. In children, RP improves the course of the postoperative period. What is the reason of such difference between children and adults remains unknown. It was shown that RP exerts an infarction-limiting effect in transcutaneous coronary interventions in patients with ST elevation myocardial infarction.

  11. Monte Carlo molecular simulation of the hydration of Na-montmorillonite at reservoir conditions.

    PubMed

    de Pablo, L; Chávez, M L; Sum, A K; de Pablo, J J

    2004-01-08

    The hydration of Na-saturated Wyoming-type montmorillonite is investigated by Monte Carlo simulations at constant stress in the NP(zz)T ensemble and at constant chemical potential in the microVT ensemble, at the sedimentary basin temperature of 353 K and pressure of 625 bar, equivalent to 2-4 km depth. The simulations use procedures established in Chavez-Paez et al. [J. Chem. Phys. 114, 1405 (2001)]. At these conditions, simulations predict a single stable form of 1,2-water layer Na-montmorillonite, containing 164.38 mg/g or 53.37 molecules/layer of adsorbed water and having a spacing of 12.72 A. The corresponding density is 0.32 g/ml. Sodium ions are coordinated with six molecules of water separated 2.30-2.33 A. Water molecules are closer to the central interlayer plane and the spacing is larger than that at 300 K and 1 bar. The interlayer configuration consists of two symmetrical layers of oriented water molecules 1.038 A from the central plane, with the hydrogen atoms in two outermost layers, 3.826 A apart, and the sodium ions on the central plane located between the water layers. The interlayer configuration can be considered to be a stable two-layer intermediate between the one- and two-layer hydrates. Our simulations do not predict formation of other hydrates of Na-montmorillonite at 353 K and 615 bar.

  12. Time-Accurate Unsteady Pressure Loads Simulated for the Space Launch System at Wind Tunnel Conditions

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.; Brauckmann, Gregory J.; Kleb, William L.; Glass, Christopher E.; Streett, Craig L.; Schuster, David M.

    2015-01-01

    A transonic flow field about a Space Launch System (SLS) configuration was simulated with the Fully Unstructured Three-Dimensional (FUN3D) computational fluid dynamics (CFD) code at wind tunnel conditions. Unsteady, time-accurate computations were performed using second-order Delayed Detached Eddy Simulation (DDES) for up to 1.5 physical seconds. The surface pressure time history was collected at 619 locations, 169 of which matched locations on a 2.5 percent wind tunnel model that was tested in the 11 ft. x 11 ft. test section of the NASA Ames Research Center's Unitary Plan Wind Tunnel. Comparisons between computation and experiment showed that the peak surface pressure RMS level occurs behind the forward attach hardware, and good agreement for frequency and power was obtained in this region. Computational domain, grid resolution, and time step sensitivity studies were performed. These included an investigation of pseudo-time sub-iteration convergence. Using these sensitivity studies and experimental data comparisons, a set of best practices to date have been established for FUN3D simulations for SLS launch vehicle analysis. To the author's knowledge, this is the first time DDES has been used in a systematic approach and establish simulation time needed, to analyze unsteady pressure loads on a space launch vehicle such as the NASA SLS.

  13. Experimental validation of an undersea free space laser network simulator in turbid coastal conditions

    NASA Astrophysics Data System (ADS)

    Rashkin, David; Dalgleish, Fraser; Cardei, Ionut; Ouyang, Bing; Vuorenkoski, Anni; Cardei, Mihaela

    2013-06-01

    Mobile, high throughput mid-range data communications and robust real-time data networking in the subsea environment that can accommodate high bandwidth sensors such as optical imagers have a potentially high impact as enabling technologies for a variety of future subsea operations in the areas of distributed sensing and real-time wireless feedback and control of unmanned undersea vehicles. Although much work has been done recently in the field of undersea optical free space communications and networking, to date there has yet to be an implementation of a complete multi-node undersea wireless optical data communications network. The deployment and testing of optical wireless network equipment in the undersea environment is expensive and time-consuming, and there is a clear need for a network simulation framework that will allow researchers to evaluate the performances of different networking concepts/configurations under realistic operational and environmental constraints. This paper describes a network simulation approach that uses an accurate time dependent Monte Carlo channel model to simulate the networking physical layer, which can be used in conjunction with higher network layer protocols to simulate larger scale network performance and to help determine hardware requirements for overall network system design in a variety of undersea channel conditions.

  14. Degradation behavior of soy protein-wheat gluten films in simulated soil conditions.

    PubMed

    Park, S K; Hettiarachchy, N S; Were, L

    2000-07-01

    Films containing soy protein and wheat gluten were exposed to simulated farmland soil mix over a period of 30 days and monitored for degradation. The simulated farmland soil mix (topsoil/sand/Sunshine compost/vermiculite, 59:6:25:10, wt %) was mixed and stored at ambient humidity (48-55%) and temperature (20-24 degrees C); the soil mix was constantly maintained at 15% moisture by weight. Research focused on evaluating the effectiveness of gluten and cysteine additions on biodegradable behavior in the simulated farmland soil conditions. The four types of films, soy protein (S:G 1:0); soy protein with cysteine addition (S:G 1:0 + CYS); soy protein-wheat gluten (S:G 4:1); and soy protein-wheat gluten with cysteine addition (S:G 4:1 + CYS), were prepared at pH 7. 0 for degradation studies. Soy protein-gluten film rapidly degraded with 50% weight loss in about 10 days and with up to 95% weight loss in 30 days. Tensile strength and elongation of all soy protein-gluten films significantly decreased in 3 days. However, cysteine addition delayed the degradation rate of soy protein-gluten films. Soy protein-wheat gluten film disintegrated after 20 days in the simulated farmland soil environment. These results suggest that wheat gluten and cysteine addition to soy protein-based films could delay degradation rates due to their high disulfide contents.

  15. Investigation into piston-slap-induced vibration for engine condition simulation and monitoring

    NASA Astrophysics Data System (ADS)

    Geng, Z.; Chen, J.

    2005-04-01

    Piston slap is a common impact phenomenon existing in the reciprocating engine. It is also a major cause of the complex transient vibration response related to the impact excitation inside the engine. In order to correlate the piston-slap impact with the slap-induced vibration and consequently find out an effective approach for the engine dynamic behaviour simulation and working condition monitoring, an in-depth investigation from theoretical modelling to experimental verification is made in this paper. Firstly, the piston-slap phenomenon inside the reciprocating engine is briefly discussed from the viewpoint of engine mechanics. Based upon this, a nonlinear model is developed to simulate the slap-induced vibration response. Using numerical integration procedure, the slap-induced vibration response and its correlation with the inner-cylinder piston-slap impact are reasonably evaluated. Guided by the simulating results and, by introducing a fast wavelet-packet decomposition and reconstruction algorithm, a specially designed experiment is made to practically measure and extract the slap-induced impact message inside the 6190Z LC diesel engine. Comparison between the simulation and practically measured and reconstructed engine vibration signals verifies the effectiveness and practicality of this approach for more detailed academic research and engineering application.

  16. Jet transport flight operations using cockpit display of traffic information during instrument meteorological conditions: Simulation evaluation

    NASA Technical Reports Server (NTRS)

    Williams, David H.; Wells, Douglas C.

    1986-01-01

    A simulation study was undertaken to evaluate flight operations using cockpit display of traffic information (CDTI) in a conventional jet transport aircraft. Eight two-person airline flight crews participated as test subjects flying simulated terminal area approach and departure operations under instrument meteorological conditions (IMC). A fixed-base cockpit simulator configured with a full complement of conventional electromechanical instrumentation to permit full workload operations was utilized. Traffic information was displayed on a color cathode-ray tube (CRT) mounted above the throttle quadrant in the typical weather radar location. A transparent touchpanel overlay was utilized for pilot interface with the display. Air traffic control (ATC) simulation included an experienced controller and full partyline radio environment for evaluation of pilot-controlled self-separation and traffic situation monitoring tasks. Results of the study revealed the CDTI to be well received by the test subjects as a useful system which could be incorporated into an existing jet transport cockpit. Crew coordination and consistent operating procedures were identified as important considerations in operational implementation of traffic displays. Cockpit workload was increased with active CDTI tasks. However, all test subjects rated the increase to be acceptable.

  17. Pellagra-like condition is xeroderma pigmentosum/Cockayne syndrome complex and niacin confers clinical benefit.

    PubMed

    Hijazi, H; Salih, M A; Hamad, M H A; Hassan, H H; Salih, S B M; Mohamed, K A; Mukhtar, M M; Karrar, Z A; Ansari, S; Ibrahim, N; Alkuraya, F S

    2015-01-01

    An extremely rare pellagra-like condition has been described, which was partially responsive to niacin and associated with a multisystem involvement. The condition was proposed to represent a novel autosomal recessive entity but the underlying mutation remained unknown for almost three decades. The objective of this study was to identify the causal mutation in the pellagra-like condition and investigate the mechanism by which niacin confers clinical benefit. Autozygosity mapping and exome sequencing were used to identify the causal mutation, and comet assay on patient fibroblasts before and after niacin treatment to assess its effect on DNA damage. We identified a single disease locus that harbors a novel mutation in ERCC5, thus confirming that the condition is in fact xeroderma pigmentosum/Cockayne syndrome (XP/CS) complex. Importantly, we also show that the previously described dermatological response to niacin is consistent with a dramatic protective effect against ultraviolet-induced DNA damage in patient fibroblasts conferred by niacin treatment. Our findings show the power of exome sequencing in reassigning previously described novel clinical entities, and suggest a mechanism for the dermatological response to niacin in patients with XP/CS complex. This raises interesting possibilities about the potential therapeutic use of niacin in XP.

  18. Simulations of the Richtmyer-Meshkov Instability with experimentally measured volumetric initial conditions

    NASA Astrophysics Data System (ADS)

    Ferguson, Kevin; Sewell, Everest; Krivets, Vitaliy; Greenough, Jeffrey; Jacobs, Jeffrey

    2016-11-01

    Initial conditions for the Richtmyer-Meshkov instability (RMI) are measured in three dimensions in the University of Arizona Vertical Shock Tube using a moving magnet galvanometer system. The resulting volumetric data is used as initial conditions for the simulation of the RMI using ARES at Lawrence-Livermore National Laboratory (LLNL). The heavy gas is sulfur hexafluoride (SF6), and the light gas is air. The perturbations are generated by harmonically oscillating the gasses vertically using two loudspeakers mounted to the shock tube which cause Faraday resonance, producing a random short wavelength perturbation on the interface. Planar Mie scattering is used to illuminate the flow field through the addition of propylene glycol particles seeded in the heavy gas. An M=1.2 shock impulsively accelerates the interface, initiating instability growth. Images of the initial condition and instability growth are captured at a rate of 6 kHz using high speed cameras. Comparisons between experimental and simulation results, mixing diagnostics, and mixing zone growth are presented.

  19. SiC/SiC Leading Edge Turbine Airfoil Tested Under Simulated Gas Turbine Conditions

    NASA Technical Reports Server (NTRS)

    Robinson, R. Craig; Hatton, Kenneth S.

    1999-01-01

    Silicon-based ceramics have been proposed as component materials for use in gas turbine engine hot-sections. A high pressure burner rig was used to expose both a baseline metal airfoil and ceramic matrix composite leading edge airfoil to typical gas turbine conditions to comparatively evaluate the material response at high temperatures. To eliminate many of the concerns related to an entirely ceramic, rotating airfoil, this study has focused on equipping a stationary metal airfoil with a ceramic leading edge insert to demonstrate the feasibility and benefits of such a configuration. Here, the idea was to allow the SiC/SiC composite to be integrated as the airfoil's leading edge, operating in a "free-floating" or unrestrained manner. and provide temperature relief to the metal blade underneath. The test included cycling the airfoils between simulated idle, lift, and cruise flight conditions. In addition, the airfoils were air-cooled, uniquely instrumented, and exposed to the same internal and external conditions, which included gas temperatures in excess of 1370 C (2500 F). Results show the leading edge insert remained structurally intact after 200 simulated flight cycles with only a slightly oxidized surface. The instrumentation clearly suggested a significant reduction (approximately 600 F) in internal metal temperatures as a result of the ceramic leading edge. The object of this testing was to validate the design and analysis done by Materials Research and Design of Rosemont, PA and to determine the feasibility of this design for the intended application.

  20. Pollutant dispersion simulation for low wind speed condition by the ILS method

    NASA Astrophysics Data System (ADS)

    Carvalho, Jonas C.; de Vilhena, Marco Túllio M. B.

    A semi-analytical Lagrangian particle model to simulate the pollutant dispersion during low wind speed conditions is presented and tested. The method relies to a stochastic integral equation whose solution is obtained using ILS method, which consists in the iterative solution of Langevin equation by the Picard's iteration method. To consider the low wind speed effect, the solution for the horizontal components of the turbulent velocity takes account the Eulerian autocorrelation function as suggested by Frenkiel [1953. Advances in Applied Mechanics 3, 61-107]. The model results are shown to agree very well with the field tracer data collected during stable conditions at Idaho National Engineering Laboratory (INEL) and during convective conditions from the series of field experiments at Indian Institute of Technology (IIT). A statistical analysis reveals that the model simulates very well the experimental data and presents results comparable or even better than ones obtained with other models used as comparison. The analytical feature of the ILS method and the inclusion of the Eulerian autocorrelation function suggested by Frenkiel (1953) allow generating more accurate results.

  1. Wave simulation in partially frozen porous media with fractal freezing conditions

    NASA Astrophysics Data System (ADS)

    Carcione, José M.; Santos, Juan E.; Ravazzoli, Claudia L.; Helle, Hans B.

    2003-12-01

    A recent article [J. M. Carcione and G. Seriani, J. Comput. Phys. 170, 676 (2001)] proposes a modeling algorithm for wave simulation in a three-phase porous medium composed of sand grains, ice, and water. The differential equations hold for uniform water (ice) content. Here, we obtain the variable-porosity differential equations by using the analogy with the two-phase case and the complementary energy theorem. The displacements of the rock and ice frames and the variation of fluid content are the generalized coordinates, and the stress components and fluid pressure are the generalized forces. We simulate wave propagation in a frozen porous medium with fractal variations of porosity and, therefore, realistic freezing conditions.

  2. Biological Membranes in Extreme Conditions: Simulations of Anionic Archaeal Tetraether Lipid Membranes

    PubMed Central

    Pineda De Castro, Luis Felipe; Dopson, Mark

    2016-01-01

    In contrast to the majority of organisms that have cells bound by di-ester phospholipids, archaeal membranes consist of di- and tetraether phospholipids. Originating from organisms that withstand harsh conditions (e.g., low pH and a wide range of temperatures) such membranes have physical properties that make them attractive materials for biological research and biotechnological applications. We developed force-field parameters based on the widely used Generalized Amber Force Field (GAFF) to enable the study of anionic tetraether membranes of the model archaean Sulfolobus acidocaldarius by computer simulations. The simulations reveal that the physical properties of these unique membranes depend on the number of cyclopentane rings included in each lipid unit, and on the size of cations that are used to ensure charge neutrality. This suggests that the biophysical properties of Sulfolobus acidocaldarius cells depend not only on the compositions of their membranes but also on the media in which they grow. PMID:27167213

  3. Numerical simulation of tonal fan noise of computers and air conditioning systems

    NASA Astrophysics Data System (ADS)

    Aksenov, A. A.; Gavrilyuk, V. N.; Timushev, S. F.

    2016-07-01

    Current approaches to fan noise simulation are mainly based on the Lighthill equation and socalled aeroacoustic analogy, which are also based on the transformed Lighthill equation, such as the wellknown FW-H equation or the Kirchhoff theorem. A disadvantage of such methods leading to significant modeling errors is associated with incorrect solution of the decomposition problem, i.e., separation of acoustic and vortex (pseudosound) modes in the area of the oscillation source. In this paper, we propose a method for tonal noise simulation based on the mesh solution of the Helmholtz equation for the Fourier transform of pressure perturbation with boundary conditions in the form of the complex impedance. A noise source is placed on the surface surrounding each fan rotor. The acoustic fan power is determined by the acoustic-vortex method, which ensures more accurate decomposition and determination of the pressure pulsation amplitudes in the near field of the fan.

  4. Initial conditions and modeling for simulations of shock driven turbulent material mixing

    SciTech Connect

    Grinstein, Fernando F.

    2016-11-17

    Here, we focus on the simulation of shock-driven material mixing driven by flow instabilities and initial conditions (IC). Beyond complex multi-scale resolution issues of shocks and variable density turbulence, me must address the equally difficult problem of predicting flow transition promoted by energy deposited at the material interfacial layer during the shock interface interactions. Transition involves unsteady large-scale coherent-structure dynamics capturable by a large eddy simulation (LES) strategy, but not by an unsteady Reynolds-Averaged Navier–Stokes (URANS) approach based on developed equilibrium turbulence assumptions and single-point-closure modeling. On the engineering end of computations, such URANS with reduced 1D/2D dimensionality and coarser grids, tend to be preferred for faster turnaround in full-scale configurations.

  5. Pose Measurement Performance of the Argon Relative Navigation Sensor Suite in Simulated Flight Conditions

    NASA Technical Reports Server (NTRS)

    Galante, Joseph M.; Eepoel, John Van; Strube, Matt; Gill, Nat; Gonzalez, Marcelo; Hyslop, Andrew; Patrick, Bryan

    2012-01-01

    Argon is a flight-ready sensor suite with two visual cameras, a flash LIDAR, an on- board flight computer, and associated electronics. Argon was designed to provide sensing capabilities for relative navigation during proximity, rendezvous, and docking operations between spacecraft. A rigorous ground test campaign assessed the performance capability of the Argon navigation suite to measure the relative pose of high-fidelity satellite mock-ups during a variety of simulated rendezvous and proximity maneuvers facilitated by robot manipulators in a variety of lighting conditions representative of the orbital environment. A brief description of the Argon suite and test setup are given as well as an analysis of the performance of the system in simulated proximity and rendezvous operations.

  6. Initial conditions and modeling for simulations of shock driven turbulent material mixing

    DOE PAGES

    Grinstein, Fernando F.

    2016-11-17

    Here, we focus on the simulation of shock-driven material mixing driven by flow instabilities and initial conditions (IC). Beyond complex multi-scale resolution issues of shocks and variable density turbulence, me must address the equally difficult problem of predicting flow transition promoted by energy deposited at the material interfacial layer during the shock interface interactions. Transition involves unsteady large-scale coherent-structure dynamics capturable by a large eddy simulation (LES) strategy, but not by an unsteady Reynolds-Averaged Navier–Stokes (URANS) approach based on developed equilibrium turbulence assumptions and single-point-closure modeling. On the engineering end of computations, such URANS with reduced 1D/2D dimensionality and coarsermore » grids, tend to be preferred for faster turnaround in full-scale configurations.« less

  7. Dissipative particle dynamics simulation of flow generated by two rotating concentric cylinders: boundary conditions.

    PubMed

    Haber, S; Filipovic, N; Kojic, M; Tsuda, A

    2006-10-01

    The dissipative particle dynamics (DPD) method was used to simulate the flow in a system comprised of a fluid occupying the space between two cylinders rotating with equal angular velocities. The fluid, initially at rest, ultimately reaches a steady, linear velocity distribution (a rigid-body rotation). Since the induced flow field is solely associated with the no-slip boundary condition at the walls, we employed this system as a benchmark to examine the effect of bounce-back reflections, specular reflections, and Pivkin-Karniadakis no-slip boundary conditions, upon the steady-state velocity, density, and temperature distributions. An additional advantage of the foregoing system is that the fluid occupies inherently a finite bounded domain so that the results are affected by the prescribed no-slip boundary conditions only. Past benchmark systems such as Couette flow between two infinite parallel plates or Poiseuille flow in an infinitely long cylinder must employ artificial periodic boundary conditions at arbitrary upstream and downstream locations, a possible source of spurious effects. In addition, the effect of the foregoing boundary conditions on the time evolution of the simulated velocity profile was compared with that of the known, time-dependent analytical solution. It was shown that bounce-back reflection yields the best results for the velocity distributions with small fluctuations in density and temperature at the inner fluid domain and larger deviations near the walls. For the unsteady solutions a good fit is obtained if the DPD friction coefficient is proportional to the kinematic viscosity. Based on dimensional analysis and the numerical results a universal correlation is suggested between the friction coefficient and the kinematic viscosity.

  8. The Effect of Nursing Faculty Presence on Students' Level of Anxiety, Self-Confidence, and Clinical Performance during a Clinical Simulation Experience

    ERIC Educational Resources Information Center

    Horsley, Trisha Leann

    2012-01-01

    Nursing schools design their clinical simulation labs based upon faculty's perception of the optimal environment to meet the students' learning needs, other programs' success with integrating high-tech clinical simulation, and the funds available. No research has been conducted on nursing faculty presence during a summative evaluation. The…

  9. Mapping and simulating systematics due to spatially varying observing conditions in DES science verification data

    DOE PAGES

    Leistedt, B.; Peiris, H. V.; Elsner, F.; ...

    2016-10-17

    Spatially varying depth and the characteristics of observing conditions, such as seeing, airmass, or sky background, are major sources of systematic uncertainties in modern galaxy survey analyses, particularly in deep multi-epoch surveys. We present a framework to extract and project these sources of systematics onto the sky, and apply it to the Dark Energy Survey (DES) to map the observing conditions of the Science Verification (SV) data. The resulting distributions and maps of sources of systematics are used in several analyses of DES–SV to perform detailed null tests with the data, and also to incorporate systematics in survey simulations. Wemore » illustrate the complementary nature of these two approaches by comparing the SV data with BCC-UFig, a synthetic sky catalog generated by forward-modeling of the DES–SV images. We analyze the BCC-UFig simulation to construct galaxy samples mimicking those used in SV galaxy clustering studies. We show that the spatially varying survey depth imprinted in the observed galaxy densities and the redshift distributions of the SV data are successfully reproduced by the simulation and are well-captured by the maps of observing conditions. The combined use of the maps, the SV data, and the BCC-UFig simulation allows us to quantify the impact of spatial systematics on N(z), the redshift distributions inferred using photometric redshifts. We conclude that spatial systematics in the SV data are mainly due to seeing fluctuations and are under control in current clustering and weak-lensing analyses. However, they will need to be carefully characterized in upcoming phases of DES in order to avoid biasing the inferred cosmological results. Finally, the framework presented here is relevant to all multi-epoch surveys and will be essential for exploiting future surveys such as the Large Synoptic Survey Telescope, which will require detailed null tests and realistic end-to-end image simulations to correctly interpret the deep, high

  10. Airflow mechanics in models of equine obstructive airway disease under conditions simulating exercise.

    PubMed

    Bayly, W M; Slocombe, R F

    1997-01-01

    Effects of respiratory tract obstructions on ventilatory mechanics in horses exercising at high speeds were tested with a fibreglass replica of the airways (nares to mainstem bronchi) of an adult horse. Segmental pressures were recorded at six sites along the model at four different unidirectional flows (1300-4100 litre min-1), and the respective resistances (R) to airflow were calculated. The external nares and the larynx made the greatest contributions to the total resistance (RTOT) when no obstruction was present. Modifying the model to simulate severe pharyngeal lymphoid hyperplasia (PLH) had no effect on R at the larynx or at any point in the trachea under these flow conditions. Two 16 litre anaesthetic rebreathing bags were attached to the bronchial end of the model, and tidal ventilation generated by a piston pump. Upper (nares to pharynx) and lower tract R (RU and RL) and RTOT, and dynamic compliance were determined for pump volumes (Vp) of six and 12 litres, at pumping frequencies (fp) of 20-100 min-1 while the airway was clear, and after modifying it to simulate either PLH or partial bronchial obstruction. Model condition had no effect on RU. However, RL and RTOT were higher in the PLH simulated condition when fp > or = 90 and Vp = 12 litres (P < 0.05). This suggested that severe PLH may significantly interfere with airflow distal to the site of the lesions during high frequency high volume ventilation of the type seen in galloping horses. With partial bronchial obstruction RL and RTOT were increased when fp > 34 with each Vp. The applicability of the model was verified by comparing results from the unobstructed state with those from normal horses exercising on a treadmill.

  11. Climate change reverses the competitive balance of ash and beech seedlings under simulated forest conditions.

    PubMed

    Saxe, H; Kerstiens, G

    2005-07-01

    This study identifies the important role of climate change and photosynthetic photon flux density (PPFD) in the regenerative competence of ash and beech seedlings in 12 inter- and intra-specific competition designs in simulated mixed ash-beech forest gaps under conditions of non-limiting soil volume, water and nutrient supply. The growth conditions simulated natural forest conditions as closely as possible. Simulations were performed by growing interacting seedling canopies for one season in temperature-regulated closed-top chambers (CTCs). Eight CTCs were used in a factorial design with replicate treatments of [CO2] x temperature x PPFD x competition design. [CO2] tracked ambient levels or was 360 micromol mol-1 higher. Temperature tracked ambient levels or was 2.8 degrees C higher. PPFD on two plant tables inside each CTC was 16% and 5% of open-field levels, respectively, representative of typical light flux levels in a natural forest gap. In several of the competition designs, climate change made the ash seedlings grow taller than the beech seedlings and, at the same time, attain a larger leaf area and a larger total biomass. Advantages of this type for ash were found particularly at lower PPFD. There was a positive synergistic interaction of elevated temperature x [CO2] for both species, but more so for ash. There are many uncertainties when a study of chambered seedlings is to be projected to real changes in natural forests. Nevertheless, this study supports a possible future shift towards ash in north European, unmanaged, mixed ash-beech forests in response to the predicted climate change.

  12. Effects of simulated Mars conditions on the survival and growth of Escherichia coli and Serratia liquefaciens.

    PubMed

    Berry, Bonnie J; Jenkins, David G; Schuerger, Andrew C

    2010-04-01

    Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions. Survival and replication of E. coli and S. liquefaciens cells in liquid medium were evaluated for 7 days under low temperatures (5, 10, 20, or 30 degrees C) with increasing concentrations (0, 5, 10, or 20%) of three salts (MgCl(2), MgSO(4), NaCl) reported to be present on the surface of Mars. Moderate to high growth rates were observed for E. coli and S. liquefaciens at 30 or 20 degrees C and in solutions with 0 or 5% salts. In contrast, cell densities of both species generally did not increase above initial inoculum levels under the highest salt concentrations (10 and 20%) and the four temperatures tested, with the exception that moderately higher cell densities were observed for both species at 10% MgSO(4) maintained at 20 or 30 degrees C. Growth rates of E. coli and S. liquefaciens in low salt concentrations were robust under all pressures (2.5, 10, or 101.3 kPa), exhibiting a general increase of up to 2.5 orders of magnitude above the initial inoculum levels of the assays. Vegetative E. coli cells were maintained in a Mars analog soil for 7 days under simulated Mars conditions that included temperatures between 20 and -50 degrees C for a day/night diurnal period, UVC irradiation (200 to 280 nm) at 3.6 W m(-2) for daytime operations (8 h), pressures held at a constant 0.71 kPa, and a gas composition that included the top five gases found in the martian atmosphere. Cell densities of E. coli failed to increase under simulated Mars conditions, and survival was reduced 1 to 2 orders of magnitude by the interactive

  13. Numerical simulations of the first operational conditions of the negative ion test facility SPIDER

    SciTech Connect

    Serianni, G. Agostinetti, P.; Antoni, V.; Baltador, C.; Chitarin, G.; Marconato, N.; Pasqualotto, R.; Sartori, E.; Toigo, V.; Veltri, P.; Cavenago, M.

    2016-02-15

    In view of the realization of the negative ion beam injectors for ITER, a test facility, named SPIDER, is under construction in Padova (Italy) to study and optimize production and extraction of negative ions. The present paper is devoted to the analysis of the expected first operations of SPIDER in terms of single-beamlet and multiple-beamlet simulations of the hydrogen beam optics in various operational conditions. The effectiveness of the methods adopted to compensate for the magnetic deflection of the particles is also assessed. Indications for a sequence of the experimental activities are obtained.

  14. Numerical simulations of the first operational conditions of the negative ion test facility SPIDER

    NASA Astrophysics Data System (ADS)

    Serianni, G.; Agostinetti, P.; Antoni, V.; Baltador, C.; Cavenago, M.; Chitarin, G.; Marconato, N.; Pasqualotto, R.; Sartori, E.; Toigo, V.; Veltri, P.

    2016-02-01

    In view of the realization of the negative ion beam injectors for ITER, a test facility, named SPIDER, is under construction in Padova (Italy) to study and optimize production and extraction of negative ions. The present paper is devoted to the analysis of the expected first operations of SPIDER in terms of single-beamlet and multiple-beamlet simulations of the hydrogen beam optics in various operational conditions. The effectiveness of the methods adopted to compensate for the magnetic deflection of the particles is also assessed. Indications for a sequence of the experimental activities are obtained.

  15. Mobile farm clinic outreach to address health conditions among Latino migrant farmworkers in Georgia.

    PubMed

    Luque, John S; Reyes-Ortiz, Carlos; Marella, Prasen; Bowers, Angelica; Panchal, Viral; Anderson, Lisa; Charles, Simone

    2012-01-01

    Agricultural labor involves exposure to many occupational hazards, some of which can lead to chronic health conditions. The purpose of this study was to conduct an occupational health needs assessment of illnesses and work-related injuries among a Latino migrant farmworker population (recruited to harvest Vidalia onions) in South Georgia. Study data included survey responses from 100 farmworkers attending mobile farm clinics in 2010 at their worker housing residences, supplemented by medical diagnoses data from the same clinics collected over 3 years (2009-2011) for 1161 farmworkers at six different farms. From the survey, the main health problems reported were hypertension (25%), eye problems (12%), musculoskeletal problems (11%), diabetes (10%), and depression (7%). In multivariate analyses, depression scores were associated with having a history of musculoskeletal problems (p = .002). According to the mobile farm clinic data, the most common medical diagnoses included back pain (11.8%), hypertension (11.4%), musculoskeletal problems (11.3%), gastrointestinal disorders (8.6%), eye problems (7.2%), dermatitis or rash (7.0%), and tinea or fungal skin infections (5.6%). The study identified eye and musculoskeletal problems as the major occupational health conditions for this population of farmworkers.

  16. Three Decades of Comprehensive Geriatric Assessment: Evidence Coming From Different Healthcare Settings and Specific Clinical Conditions.

    PubMed

    Pilotto, Alberto; Cella, Alberto; Pilotto, Andrea; Daragjati, Julia; Veronese, Nicola; Musacchio, Clarissa; Mello, Anna Maria; Logroscino, Giancarlo; Padovani, Alessandro; Prete, Camilla; Panza, Francesco

    2017-02-01

    Comprehensive geriatric assessment (CGA) is a multidisciplinary diagnostic and treatment process that identifies medical, psychosocial, and functional capabilities of older adults to develop a coordinated plan to maximize overall health with aging. Specific criteria used by CGA programs to evaluate patients include age, medical comorbidities, psychosocial problems, previous or predicted high healthcare utilization, change in living situation, and specific geriatric conditions. However, no universal criteria have been agreed upon to readily identify patients who are likely to benefit from CGA. Evidence from randomized controlled trials and large systematic reviews and meta-analyses suggested that the healthcare setting may modify the effectiveness of CGA programs. Home CGA programs and CGA performed in the hospital were shown to be consistently beneficial for several health outcomes. In contrast, the data are conflicting for posthospital discharge CGA programs, outpatient CGA consultation, and CGA-based inpatient geriatric consultation services. The effectiveness of CGA programs may be modified also by particular settings or specific clinical conditions, with tailored CGA programs in older frail patients evaluated for preoperative assessment, admitted or discharged from emergency departments and orthogeriatric units or with cancer and cognitive impairment. CGA is capable of effectively exploring multiple domains in older age, being the multidimensional and multidisciplinary tool of choice to determine the clinical profile, the pathologic risk and the residual skills as well as the short- and long-term prognosis to facilitate the clinical decision making on the personalized care plan of older persons.

  17. Clinical compliance of viewing conditions in radiology reporting environments against current guidelines and standards

    NASA Astrophysics Data System (ADS)

    Daly, S.; Rainford, L.; Butler, M. L.

    2014-03-01

    Several studies have demonstrated the importance of environmental conditions in the radiology reporting environment, with many indicating that incorrect parameters could lead to error and misinterpretation. Literature is available with recommendations as to the levels that should be achieved in clinical practice, but evidence of adherence to these guidelines in radiology reporting environments is absent. This study audited the reporting environments of four teleradiologist and eight hospital based radiology reporting areas. This audit aimed to quantify adherence to guidelines and identify differences in the locations with respect to layout and design, monitor distance and angle as well as the ambient factors of the reporting environments. In line with international recommendations, an audit tool was designed to enquire in relation to the layout and design of reporting environments, monitor angle and distances used by radiologists when reporting, as well as the ambient factors such as noise, light and temperature. The review of conditions were carried out by the same independent auditor for consistency. The results obtained were compared against international standards and current research. Each radiology environment was given an overall compliance score to establish whether or not their environments were in line with recommended guidelines. Poor compliance to international recommendations and standards among radiology reporting environments was identified. Teleradiology reporting environments demonstrated greater compliance than hospital environments. The findings of this study identified a need for greater awareness of environmental and perceptual issues in the clinical setting. Further work involving a larger number of clinical centres is recommended.

  18. Dynamics of Plug Formation in a Circular Cylinder Under Low Bond Number Conditions: Experiment and Simulation

    NASA Astrophysics Data System (ADS)

    Hallaby, Ghazi; Kizito, John P.

    2016-08-01

    The goal of the current study is to investigate the dynamics of two phase interface under a low Bond number condition. Silicone oil is injected into a cylinder under a Bond number of about 0.47 via a side tube forming a T-junction with the former. The time evolution of the interface of silicon oil in a cylinder is captured using a high speed camera. The volume at which the plug is formed is then determined using an image processing tool to analyze the captured images. A numerical simulation is carried out where fluid is injected into a cylinder, under a less than unity Bond number condition, via a side tube. Numerical and experimental results are then compared.

  19. Acrylic bone cements with bismuth salicylate: Behavior in simulated physiological conditions.

    PubMed

    Hernández, L; Vázquez, B; López-Bravo, A; Parra, J; Goñi, I; Gurruchaga, M

    2007-02-01

    In a previous work, we reported the development of acrylic bone cement formulations for application in percutaneous vertebroplasty, by using bismuth salicylate (BS) as the radiopaque agent. Our objective was to obtain high radiopacity along with a therapeutical effect produced by the release of salicylic acid in situ. To follow that study, the setting kinetics and static and dynamical mechanical properties of the BS cements were studied in simulated physiological conditions. Moreover, radiopacity after various times of immersion in saline and the wettability of the cements surfaces were determined. The study finished with the analysis of the biological response. From the results, it can be concluded that physiological conditions did not affect negatively to the cements performance, since all BS-loaded cements fulfilled the ISO standard requirements. Radiopacity of the formulations was maintained over time and cements with BS were found to be biocompatible.

  20. Performance of a catalytic reactor at simulated gas turbine combustor operating conditions

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.; Tacina, R. R.; Mroz, T. S.

    1975-01-01

    The performance of a catalytic reactor 12 cm in diameter and 17 cm long was evaluated at simulated gas turbine combustor operating conditions using premixed propane and air. Inlet temperatures of 600 and 800 K, pressures of 3 and 6 atm, and reference velocities of 9 to 30 m/s were tested. Data were taken for equivalence ratios as high as 0.43. The operating range was limited on the low-temperature side by very poor efficiency; the minimum exit temperature for good performance ranged from 1400 to 1600 K depending on inlet conditions. As exit temperatures were raised above this minimum, emissions of unburned hydrocarbons decreased, carbon monoxide emissions became generally less than 1 g CO/kg fuel, and nitrogen oxides were less than about 0.1 g NO2/kg fuel.

  1. Bleed-boundary conditions for numerically simulated mixed-compression supersonic inlet flow

    NASA Technical Reports Server (NTRS)

    Chyu, W. J.; Howe, G. W.; Shih, T. I-P.

    1992-01-01

    A numerical study was performed to investigate boundary conditions for bleed openings that are needed in the numerical simulation of critical flow through turbojet inlets with bleed. Nine different boundary conditions (BCs) were devised and examined. Of the BCs examined, three were able to stabilize the terminal shock near the inlet's throat. This numerical study was based on the ensemble-averaged, unsteady, three-dimensional, compressible Navier-Stokes equations closed by the Baldwin-Lomax algebraic turbulence model. Solutions to the Navier-Stokes equations were obtained by using a hybrid implicit-explicit method (Beam and Warming/MacCormack). The multiblock grid system used in the solution procedure was generated by solving a set of elliptic partial differential equations. Solutions obtained were compared with available experimental data.

  2. Numerical simulation of hyperbolic heat conduction with convection boundary conditions and pulse heating effects

    NASA Technical Reports Server (NTRS)

    Glass, David E.; Tamma, Kumar K.; Railkar, Sudhir B.

    1989-01-01

    The paper describes the numerical simulation of hyperbolic heat conduction with convection boundary conditions. The effects of a step heat loading, a sudden pulse heat loading, and an internal heat source are considered in conjunction with convection boundary conditions. Two methods of solution are presened for predicting the transient behavior of the propagating thermal disturbances. In the first method, MacCormack's predictor-corrector method is employed for integrating the hyperbolic system of equations. Next, the transfinite element method, which employs specially tailored elements, is used for accurately representing the transient response of the propagating thermal wave fronts. The agreement between the results of various numerical test cases validate the representative behavior of the thermal wave fronts. Both methods represent hyperbolic heat conduction behavior by effectively modeling the sharp discontinuities of the propagating thermal disturbances.

  3. Instant Experience in Clinical Trials: A Computer-Aided Simulation Technique

    ERIC Educational Resources Information Center

    Simpson, Michael A.

    1976-01-01

    Describes "Instant Experience," a simulation and game method in which students are given information about a promising new drug and asked to design a protocol for a clinical trial of the drug. Evaluation of a trial workshop showed positive response to the method. Educational goals to be achieved through its use are noted. (JT)

  4. Human Patient Simulations: Evaluation of Self-Efficacy and Anxiety in Clinical Skills Performance

    ERIC Educational Resources Information Center

    Onovo, Grace N.

    2013-01-01

    The relationship between self-efficacy (self-confidence) and anxiety levels, and the use of Human Patient Simulations (HPS) as a teaching-learning strategy, has not been sufficiently studied in the area of clinical nursing education. Despite the evidence in the literature indicating that HPS increases self-efficacy/self-confidence and decreases…

  5. Assessment of the Impact of Integrated Simulation on Critical Thinking and Clinical Judgment in Nursing Instruction

    ERIC Educational Resources Information Center

    Meyer, Rita Allen

    2012-01-01

    The purpose of this study was to explore the effects of using simulation and didactic instruction on critical thinking and clinical judgment with student nurses enrolled in a fall semester medical-surgical class. Specifically, it was of interest to compare the performance of these fall semester nursing students with the performance of nursing…

  6. 42 CFR 410.165 - Payment for rural health clinic services and ambulatory surgical center services: Conditions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Payment for rural health clinic services and... (SMI) BENEFITS Payment of SMI Benefits § 410.165 Payment for rural health clinic services and ambulatory surgical center services: Conditions. (a) Medicare Part B pays for covered rural health clinic...

  7. On simulating lipid bilayers with an applied surface tension: periodic boundary conditions and undulations.

    PubMed Central

    Feller, S E; Pastor, R W

    1996-01-01

    As sketched in Fig. 1, a current molecular dynamics computer simulation of a lipid bilayer fails to capture significant features of the macroscopic system, including long wavelength undulations. Such fluctuations are intrinsically connected to the value of the macroscopic (or thermodynamic) surface tension (cf. Eqs. 1 and 9; for a related treatment, see Brochard et al., 1975, 1976). Consequently, the surface tension that might be evaluated in an MD simulation should not be expected to equal the surface tension obtained from macroscopic measurements. Put another way, the largest of the three simulations presented here contained over 16,000 atoms and required substantial computer time to complete, but modeled a system of only 36 lipids per side. From this perspective it is not surprising that the system is not at the thermodynamic limit. An important practical consequence of this effect is that simulations with fluctuating area should be carried out with a nonzero applied surface tension (gamma 0 of Fig. 2) even when the macroscopic tension is zero, or close to zero. Computer simulations at fixed surface area, which can explicitly determine pressure anisotropy at the molecular level, should ultimately lend insight into the value of gamma 0, including its dependence on lipid composition and other membrane components. As we have noted and will describe further in separate publications (Feller et al., 1996; Feller et al., manuscript in preparation), surface tensions obtained from simulations can be distorted by inadequate initial conditions and convergence, and are sensitive to potential energy functions, force truncation methods, and system size; it is not difficult, in fact, to tune terms in the potential energy function so as to yield surface tensions close to zero. This is why parameters should be tested extensively on simpler systems, for example, monolayers. The estimates of gamma 0 that we have presented here should be regarded as qualitative, and primarily

  8. Rate Theory Modeling and Simulation of Silicide Fuel at LWR Conditions

    SciTech Connect

    Miao, Yinbin; Ye, Bei; Hofman, Gerard; Yacout, Abdellatif; Gamble, Kyle; Mei, Zhi-Gang

    2016-08-29

    As a promising candidate for the accident tolerant fuel (ATF) used in light water reactors (LWRs), the fuel performance of uranium silicide (U3Si2) at LWR conditions needs to be well understood. In this report, rate theory model was developed based on existing experimental data and density functional theory (DFT) calculations so as to predict the fission gas behavior in U3Si2 at LWR conditions. The fission gas behavior of U3Si2 can be divided into three temperature regimes. During steady-state operation, the majority of the fission gas stays in intragranular bubbles, whereas the dominance of intergranular bubbles and fission gas release only occurs beyond 1000 K. The steady-state rate theory model was also used as reference to establish a gaseous swelling correlation of U3Si2 for the BISON code. Meanwhile, the overpressurized bubble model was also developed so that the fission gas behavior at LOCA can be simulated. LOCA simulation showed that intragranular bubbles are still dominant after a 70 second LOCA, resulting in a controllable gaseous swelling. The fission gas behavior of U3Si2 at LWR conditions is benign according to the rate theory prediction at both steady-state and LOCA conditions, which provides important references to the qualification of U3Si2 as a LWR fuel material with excellent fuel performance and enhanced accident tolerance.

  9. Atomistic Simulations of Chemical Reactivity of TATB Under Thermal and Shock Conditions

    SciTech Connect

    Manaa, M R; Reed, E J; Fried, L E

    2009-09-23

    The study of chemical transformations that occur at the reactive shock front of energetic materials provides important information for the development of predictive models at the grain-and continuum scales. A major shortcoming of current high explosives models is the lack of chemical kinetics data of the reacting explosive in the high pressure and temperature regimes. In the absence of experimental data, long-time scale atomistic molecular dynamics simulations with reactive chemistry become a viable recourse to provide an insight into the decomposition mechanism of explosives, and to obtain effective reaction rate laws. These rates can then be incorporated into thermo-chemical-hydro codes (such as Cheetah linked to ALE3D) for accurate description of the grain and macro scales dynamics of reacting explosives. In this talk, I will present quantum simulations of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) crystals under thermal decomposition (high density and temperature) and shock compression conditions. This is the first time that condensed phase quantum methods have been used to study the chemistry of insensitive high explosives. We used the quantum-based, self-consistent charge density functional tight binding method (SCC{_}DFTB) to calculate the interatomic forces for reliable predictions of chemical reactions, and to examine electronic properties at detonation conditions for a relatively long time-scale on the order of several hundreds of picoseconds. For thermal decomposition of TATB, we conducted constant volume-temperature simulations, ranging from 0.35 to 2 nanoseconds, at {rho} = 2.87 g/cm{sup 3} at T = 3500, 3000, 2500, and 1500 K, and {rho} = 2.9 g/cm{sup 3} and 2.72 g/cm{sup 3}, at T = 3000 K. We also simulated crystal TATB's reactivity under steady overdriven shock compression using the multi-scale shock technique. We conducted shock simulations with specified shock speeds of 8, 9, and 10 km/s for up to 0.43 ns duration, enabling us to track the

  10. Feather conditions and clinical scores as indicators of broilers welfare at the slaughterhouse.

    PubMed

    Saraiva, S; Saraiva, C; Stilwell, G

    2016-08-01

    The objective of this study was to evaluate the welfare of 64 different broiler farms on the basis of feather conditions and clinical scores measures collected at the slaughterhouse. A 3-point scale (0, 1 or 2) was used to classify dirty feathers, footpad dermatitis and hock burns measures, and a 2-point scale (present or absent) was used to classify breast burns, breast blisters and breast ulcer measures. Flocks were allocated into three body weight (BW) classes (A, B, C): class A (light) ≥1.43 and ≤1.68kg, class B (medium) ≥1.69 and ≤1.93kg; class C (heavy) ≥1.94 and ≤2.41kg. The absence of hock burns was more common in class A, while mild hock burns was more common in class B flocks. Breast ulcer was observed in class C flocks. The association observed for mild hock burns, breast burns and severe footpad dermatitis can indicate a simultaneous occurrence of these painful lesions. Very dirty feathers and severe footpad dermatitis relationship suggest litter humidity to be the common underlying cause. In conclusion, it was shown that clinical indicators can be used at the slaughterhouse to identify welfare problems. In the studied flocks, footpad dermatitis, feather conditions and hock burns were the main restrictions for good welfare and should be considered significant welfare indicators of the on-farm rearing conditions.

  11. Effect of shadowing on survival of bacteria under conditions simulating the Martian atmosphere and UV radiation.

    PubMed

    Osman, Shariff; Peeters, Zan; La Duc, Myron T; Mancinelli, Rocco; Ehrenfreund, Pascale; Venkateswaran, Kasthuri

    2008-02-01

    Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-microm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-microm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (approximately 5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars.

  12. DSMC Simulation of Separated Flows About Flared Bodies at Hypersonic Conditions

    NASA Technical Reports Server (NTRS)

    Moss, James N.

    2000-01-01

    This paper describes the results of a numerical study of interacting hypersonic flows at conditions that can be produced in ground-based test facilities. The computations are made with the direct simulation Monte Carlo (DSMC) method of Bird. The focus is on Mach 10 flows about flared axisymmetric configurations, both hollow cylinder flares and double cones. The flow conditions are those for which experiments have been or will be performed in the ONERA R5Ch low-density wind tunnel and the Calspan-University of Buffalo Research Center (CUBRC) Large Energy National Shock (LENS) tunnel. The range of flow conditions, model configurations, and model sizes provides a significant range of shock/shock and shock/boundary layer interactions at low Reynolds number conditions. Results presented will highlight the sensitivity of the calculations to grid resolution, contrast the differences in flow structure for hypersonic cold flows and those of more energetic but still low enthalpy flows, and compare the present results with experimental measurements for surface heating, pressure, and extent of separation.

  13. Spinal muscle activity in simulated rugby union scrummaging is affected by different engagement conditions.

    PubMed

    Cazzola, D; Stone, B; Holsgrove, T P; Trewartha, G; Preatoni, E

    2016-04-01

    Biomechanical studies of rugby union scrummaging have focused on kinetic and kinematic analyses, while muscle activation strategies employed by front-row players during scrummaging are still unknown. The aim of the current study was to investigate the activity of spinal muscles during machine and live scrums. Nine male front-row forwards scrummaged as individuals against a scrum machine under "crouch-touch-set" and "crouch-bind-set" conditions, and against a two-player opposition in a simulated live condition. Muscle activities of the sternocleidomastoid, upper trapezius, and erector spinae were measured over the pre-engagement, engagement, and sustained-push phases. The "crouch-bind-set" condition increased muscle activity of the upper trapezius and sternocleidomastoid before and during the engagement phase in machine scrummaging. During the sustained-push phase, live scrummaging generated higher activities of the erector spinae than either machine conditions. These results suggest that the pre-bind, prior to engagement, may effectively prepare the cervical spine by stiffening joints before the impact phase. Additionally, machine scrummaging does not replicate the muscular demands of live scrummaging for the erector spinae, and for this reason, we advise rugby union forwards to ensure scrummaging is practiced in live situations to improve the specificity of their neuromuscular activation strategies in relation to resisting external loads.

  14. Simulation of VSPT Experimental Cascade Under High and Low Free-Stream Turbulence Conditions

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.; Giel, Paul W.; Flegel, Ashlie B.

    2014-01-01

    Variable-Speed Power Turbines (VSPT) for rotorcraft applications operate at low Reynolds number and over a wide range in incidence associated with shaft speed change. A comprehensive linear cascade data set obtained includes the effects of Reynolds number, free-stream turbulence and incidence is available and this paper concerns itself with the presentation and numerical simulation of conditions resulting in a selected set of those data. As such, post-dictions of blade pressure loading, total-pressure loss and exit flow angles under conditions of high and low turbulence intensity for a single Reynolds number are presented. Analyses are performed with the three-equation turbulence models of Walters-Leylek and Walters and Cokljat. Transition, loading, total-pressure loss and exit angle variations are presented and comparisons are made with experimental data as available. It is concluded that at the low freestream turbulence conditions the Walters-Cokljat model is better suited to predictions while for high freestream conditions the two models generate similar predications that are generally satisfactory.

  15. Simulation Modeling for Off-Nominal Conditions - Where Are We Today?

    NASA Technical Reports Server (NTRS)

    Shah, Gautam H.; Foster, John V.; Cunningham, Kevin

    2010-01-01

    The modeling of aircraft flight characteris4cs in off-nominal or otherwise adverse conditions has become increasingly important for simulation in the loss-of-control arena. Adverse conditions include environmentally-induced upsets such as wind shear or wake vortex encounters; off-nominal flight conditions, such as stall or departure; on-board systems failures; and structural failures or aircraft damage. Spirited discussions in the research community are taking place as to the fidelity and data requirements for adequate representation of vehicle dynamics under such conditions for a host of research areas, including recovery training, flight controls development, trajectory guidance/planning, and envelope limiting. The increasing need for multiple sources of data (empirical, computational, experimental) for modeling across a larger flight envelope leads to challenges in developing methods of appropriately applying or combining such data, particularly in a dynamic flight environment with a physically and/or aerodynamically asymmetric vehicle. Traditional simplifications and symmetry assumptions in current modeling methodology may no longer be valid. Furthermore, once modeled, challenges abound in the validation of flight dynamics characteristics in adverse flight regimes

  16. Simulation of VSPT Experimental Cascade Under High and Low Free-Stream Turbulence Conditions

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.; Giel, Paul W.; Flegel, Ashlie B.

    2015-01-01

    Variable-Speed Power Turbines (VSPT) for rotorcraft applications operate at low Reynolds number and over a wide range in incidence associated with shaft speed change. A comprehensive linear cascade data set obtained includes the effects of Reynolds number, free-stream turbulence and incidence is available and this paper concerns itself with the presentation and numerical simulation of conditions resulting in a selected set of those data. As such, post-dictions of blade pressure loading, total-pressure loss and exit flow angles under conditions of high and low turbulence intensity for a single Reynolds number are presented. Analyses are performed with the three-equation turbulence models of Walters- Leylek and Walters and Cokljat. Transition, loading, total-pressure loss and exit angle variations are presented and comparisons are made with experimental data as available. It is concluded that at the low freestream turbulence conditions the Walters-Cokljat model is better suited to predictions while for high freestream conditions the two models generate similar predications that are generally satisfactory.

  17. Extracting temporal constraints from clinical research eligibility criteria using conditional random fields.

    PubMed

    Luo, Zhihui; Johnson, Stephen B; Lai, Albert M; Weng, Chunhua

    2011-01-01

    Temporal constraints are present in 38% of clinical research eligibility criteria and are crucial for screening patients. However, eligibility criteria are often written as free text, which is not amenable for computer processing. In this paper, we present an ontology-based approach to extracting temporal information from clinical research eligibility criteria. We generated temporal labels using a frame-based temporal ontology. We manually annotated 150 free-text eligibility criteria using the temporal labels and trained a parser using Conditional Random Fields (CRFs) to automatically extract temporal expressions from eligibility criteria. An evaluation of an additional 60 randomly selected eligibility criteria using manual review achieved an overall precision of 83%, a recall of 79%, and an F-score of 80%. We illustrate the application of temporal extraction with the use cases of question answering and free-text criteria querying.

  18. Clinical study and numerical simulation of brain cancer dynamics under radiotherapy

    NASA Astrophysics Data System (ADS)

    Nawrocki, S.; Zubik-Kowal, B.

    2015-05-01

    We perform a clinical and numerical study of the progression of brain cancer tumor growth dynamics coupled with the effects of radiotherapy. We obtained clinical data from a sample of brain cancer patients undergoing radiotherapy and compare it to our numerical simulations to a mathematical model of brain tumor cell population growth influenced by radiation treatment. We model how the body biologically receives a physically delivered dose of radiation to the affected tumorous area in the form of a generalized LQ model, modified to account for the conversion process of sublethal lesions into lethal lesions at high radiation doses. We obtain good agreement between our clinical data and our numerical simulations of brain cancer progression given by the mathematical model, which couples tumor growth dynamics and the effect of irradiation. The correlation, spanning a wide dataset, demonstrates the potential of the mathematical model to describe the dynamics of brain tumor growth influenced by radiotherapy.

  19. Validation of a Monte Carlo model used for simulating tube current modulation in computed tomography over a wide range of phantom conditions/challenges

    SciTech Connect

    Bostani, Maryam McMillan, Kyle; Cagnon, Chris H.; McNitt-Gray, Michael F.; DeMarco, John J.

    2014-11-01

    Purpose: Monte Carlo (MC) simulation methods have been widely used in patient dosimetry in computed tomography (CT), including estimating patient organ doses. However, most simulation methods have undergone a limited set of validations, often using homogeneous phantoms with simple geometries. As clinical scanning has become more complex and the use of tube current modulation (TCM) has become pervasive in the clinic, MC simulations should include these techniques in their methodologies and therefore should also be validated using a variety of phantoms with different shapes and material compositions to result in a variety of differently modulated tube current profiles. The purpose of this work is to perform the measurements and simulations to validate a Monte Carlo model under a variety of test conditions where fixed tube current (FTC) and TCM were used. Methods: A previously developed MC model for estimating dose from CT scans that models TCM, built using the platform of MCNPX, was used for CT dose quantification. In order to validate the suitability of this model to accurately simulate patient dose from FTC and TCM CT scan, measurements and simulations were compared over a wide range of conditions. Phantoms used for testing range from simple geometries with homogeneous composition (16 and 32 cm computed tomography dose index phantoms) to more complex phantoms including a rectangular homogeneous water equivalent phantom, an elliptical shaped phantom with three sections (where each section was a homogeneous, but different material), and a heterogeneous, complex geometry anthropomorphic phantom. Each phantom requires varying levels of x-, y- and z-modulation. Each phantom was scanned on a multidetector row CT (Sensation 64) scanner under the conditions of both FTC and TCM. Dose measurements were made at various surface and depth positions within each phantom. Simulations using each phantom were performed for FTC, detailed x–y–z TCM, and z-axis-only TCM to obtain

  20. 3-D simulation of gases transport under condition of inert gas injection into goaf

    NASA Astrophysics Data System (ADS)

    Liu, Mao-Xi; Shi, Guo-Qing; Guo, Zhixiong; Wang, Yan-Ming; Ma, Li-Yang

    2016-12-01

    To prevent coal spontaneous combustion in mines, it is paramount to understand O2 gas distribution under condition of inert gas injection into goaf. In this study, the goaf was modeled as a 3-D porous medium based on stress distribution. The variation of O2 distribution influenced by CO2 or N2 injection was simulated based on the multi-component gases transport and the Navier-Stokes equations using Fluent. The numerical results without inert gas injection were compared with field measurements to validate the simulation model. Simulations with inert gas injection show that CO2 gas mainly accumulates at the goaf floor level; however, a notable portion of N2 gas moves upward. The evolution of the spontaneous combustion risky zone with continuous inert gas injection can be classified into three phases: slow inerting phase, rapid accelerating inerting phase, and stable inerting phase. The asphyxia zone with CO2 injection is about 1.25-2.4 times larger than that with N2 injection. The efficacy of preventing and putting out mine fires is strongly related with the inert gas injecting position. Ideal injections are located in the oxidation zone or the transitional zone between oxidation zone and heat dissipation zone.

  1. Measuring Water Content and Desorption Isotherms in Soil Simulants Under Martian Conditions

    NASA Astrophysics Data System (ADS)

    Hudson, T.; Aharonson, O.; Schorghofer, N.; Hecht, M. H.; Bridges, N.; Green, J. R.

    2003-12-01

    Theoretical predictions as well as recent spacecraft observations indicate that large quantities of ice is present in the high latitudes upper decimeters to meters of the Martian regolith. At shallower depths and warmer locations small amounts of H2O, either adsorbed or free, may be present transiently. We seek to simulate Mars surface conditions and to observe the effects of temperature cycling (diurnal and seasonal scale) on the water content profiles of several soil simulants. To model the upper Martian regolith, we begin by using crushed JSC Mars-1 palagonite with particles in the 50 micron to sub-micron size range. Spheres of pure silica in the 10 to 40 mm range may also be used to study the effects of grain surface morphology and composition. Simulants with various water contents are brought to Mars pressures and monitored. A line source heat-pulse probe is being prepared to monitor water content profiles in real-time and to be calibrated against water content samples measured with thermogravimetric (TG) analysis. Initial experiments will allow us to monitor water content; more refined investigations will permit the determination of desorption isotherms.

  2. Mechanical Behavior of Tissue Simulants and Soft Tissues Under Extreme Loading Conditions

    NASA Astrophysics Data System (ADS)

    Kalcioglu, Zeynep Ilke

    Recent developments in computer-integrated surgery and in tissue-engineered constructs necessitate advances in experimental and analytical techniques in characterizing properties of mechanically compliant materials such as gels and soft tissues, particularly for small sample volumes. One goal of such developments is to quantitatively predict and mimic tissue deformation due to high rate impact events typical of industrial accidents and ballistic insults. This aim requires advances in mechanical characterization to establish tools and design principles for tissue simulant materials that can recapitulate the mechanical responses of hydrated soft tissues under dynamic contact-loading conditions. Given this motivation, this thesis studies the mechanical properties of compliant synthetic materials developed for tissue scaffold applications and of soft tissues, via modifying an established contact based technique for accurate, small scale characterization under fully hydrated conditions, and addresses some of the challenges in the implementation of this method. Two different engineered material systems composed of physically associating block copolymer gels, and chemically crosslinked networks including a solvent are presented as potential tissue simulants for ballistic applications, and compared directly to soft tissues from murine heart and liver. In addition to conventional quasistatic and dynamic bulk mechanical techniques that study macroscale elastic and viscoelastic properties, new methodologies are developed to study the small scale mechanical response of the aforementioned material systems to concentrated impact loading. The resistance to penetration and the energy dissipative constants are quantified in order to compare the deformation of soft tissues and mechanically optimized simulants, and to identify the underlying mechanisms by which the mechanical response of these tissue simulant candidates are modulated. Finally, given that soft tissues are biphasic in

  3. Thermal resistance of attic loose-fill insulations decreases under simulated winter conditions

    SciTech Connect

    Graves, R.S.; Wilkes, K.E.; McElroy, D.L.

    1994-05-01

    Two absolute techniques were used to measure the thermal resistance of attic loose-fill insulations: the Large Scale Climate Simulator (LSCS) and the Unguarded Thin-Heater Apparatus (UTHA). Two types of attic loose-fill insulations (unbonded and bonded/cubed) were tested under simulated winter conditions. To simulate winter conditions for an attic insulation, the specimens were tested with heat flow up, large temperature differences, and an air gap. The specimens were tested either with a constant mean temperature (30 or 21{degrees}C) and an increasing temperature difference or with a constant base temperature (21{degrees}C) and an increasing temperature difference (i.e., a decreasing mean temperature). The UTHA test specimens had a nominal thickness of 0.2 m of loose-fill insulation. The LSCS test specimens had a nominal thickness of 0.3 m of loose-fill insulation contained in a 4.2 by 5 m attic test module with a gypsum board base. The module had a gabled attic with a 5 in 12 slope roof. The tests yielded the surface-to-surface thermal resistance, R, which includes the thermal resistance due to gypsum, insulation, and any wood joists. Tests with and without an air gap were conducted in the UTHA. Surface-to-surface thermal resistance results from the LSCS and the UTHA show similar trends for these two types of loose-fill insulation when tested under simulated winter conditions. Tests with no air gap gave values of R that agreed with the bag label R-value for the insulations; R increased with lower mean temperatures. These no-gap values of R were 2 to 5% greater than the values of R obtained with an air gap for temperature differences of less than 22{degrees}C. For larger temperature differences R decreased, and at temperature differences of over 40{degrees}C, the R values were 50% less than those at small temperature differences.

  4. Raman spectroscopy of murine bone in response to simulated spaceflight conditions

    NASA Astrophysics Data System (ADS)

    Mandair, Gurjit S.; Bateman, Ted A.; Morris, Michael D.

    2009-02-01

    Astronauts exposed to spaceflight conditions can lose 1-2% of their bone mineral density per month from the weight-bearing portions of the skeletal system. Low bone mineral density, termed osteopenia, is the result of decreased bone formation and/or increased bone resorption. In this study, Raman spectroscopy is used to examine if the physicochemical composition of murine femurs is altered in response to simulated spaceflight conditions (hindlimb suspension). Female C57BL/6J mice, aged 53 days, were divided into ground control and simulated spaceflight groups for a period of 12 days, modeling the experiment profile of mice flown on Space Shuttle flight STS-108. After the study, the mice were sacrificed and femur specimens harvested. Mid-diaphysis sections were probed using near-infrared Raman microscopy. Spectra were collected at various anatomical sites (anterior, lateral, medial, and posterior quadrants) and/or cortical locations (periosteal, midosteal, and endosteal). Chemometric recovery of spectra was employed to reduce signal contributions from the epoxy embedding agent. Mean values for mineralization, carbonation, crystallinity, and other parameters associated with the matrix were estimated. Correlations between mineralization and carbonation were observed, despite the small absolute changes between the two groups. We present more detailed analysis of this data and comment on the prospects for Raman spectroscopic evaluation of bone quality in hindlimb suspended (HLS) specimens.

  5. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1988-01-01

    In the first half of this grant year, laboratory measurements were conducted on the millimeter-wave properties of atmospheric gases under simulated conditions for the outer planet. Significant improvements in the current system have made it possible to accurately characterize the opacity from gaseous NH3 at longer millimeter wavelengths (7 to 10 mm) under simulated Jovian conditions. In the second half of the grant year, it is hoped to extend such measurements to even shorter millimeter-wavelengths. Further analysis and application of the laboratory results to microwave and millimeter-wave absorption data for the outer planets, such as results from Voyager Radio Occultation experiments and earth-based radio astronomical observations will be continued. The analysis of available multispectral microwave opacity data from Venus, including data from the most recent radio astronomical ovservations in the 1.3 to 3.6 cm wavelength range and newly obtained Pioneer-Venus Radio Occulatation measurements at 13 cm, using the laboratory measurements as an interpretative tool will be pursued.

  6. Simulating wave-turbulence on thin elastic plates with arbitrary boundary conditions

    NASA Astrophysics Data System (ADS)

    van Rees, Wim M.; Mahadevan, L.

    2016-11-01

    The statistical characteristics of interacting waves are described by the theory of wave turbulence, with the study of deep water gravity wave turbulence serving as a paradigmatic physical example. Here we consider the elastic analog of this problem in the context of flexural waves arising from vibrations of a thin elastic plate. Such flexural waves generate the unique sounds of so-called thunder machines used in orchestras - thin metal plates that make a thunder-like sound when forcefully shaken. Wave turbulence in elastic plates is typically investigated numerically using spectral simulations with periodic boundary conditions, which are not very realistic. We will present the results of numerical simulations of the dynamics of thin elastic plates in physical space, with arbitrary shapes, boundary conditions, anisotropy and inhomogeneity, and show first results on wave turbulence beyond the conventionally studied rectangular plates. Finally, motivated by a possible method to measure ice-sheet thicknesses in the open ocean, we will further discuss the behavior of a vibrating plate when floating on an inviscid fluid.

  7. Fuel Accident Condition Simulator (FACS) Furnace for Post-Irradiation Heating Tests of VHTR Fuel Compacts

    SciTech Connect

    Paul A Demkowicz; Paul Demkowicz; David V Laug

    2010-10-01

    Abstract –Fuel irradiation testing and post-irradiation examination are currently in progress as part of the Next Generation Nuclear Plant Fuels Development and Qualification Program. The PIE campaign will include extensive accident testing of irradiated very high temperature reactor fuel compacts to verify fission product retention characteristics at high temperatures. This work will be carried out at both the Idaho National Laboratory (INL) and the Oak Ridge National Laboratory, beginning with accident tests on irradiated fuel from the AGR-1 experiment in 2010. A new furnace system has been designed, built, and tested at INL to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000°C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, Eu, and I) and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator (FACS) furnace system, as well as preliminary system calibration results.

  8. Sunset decay of the convective turbulence with Large-Eddy Simulation under realistic conditions

    NASA Astrophysics Data System (ADS)

    Rizza, U.; Miglietta, M. M.; Degrazia, G. A.; Acevedo, O. C.; Marques Filho, E. P.

    2013-10-01

    Large-Eddy Simulation is performed for a single day from the Cooperative Atmosphere-Surface Exchange Study (CASES-99) field program. This study investigates an observed case of evening transition boundary layer over land. Parameters of the ambient atmosphere in the LES-decay studies conducted so far were typically prescribed in an idealized form. To provide suitable data under the wide range of the PBL weather conditions, the LES should be able to adequately reproduce the PBL turbulence dynamics including-if possible-baroclinicity, radiation, large scale advection and not only be related to a decreasing surface heating. In addition LES-decay studies usually assume that the sensible heat flux decreases instantaneously or with a very short time scale. The main purpose of this investigation is to study the decay of boundary-layer average turbulent kinetic energy at sunset with Large-Eddy Simulation that is forced with realistic environment conditions. This allows investigating the Turbulent Kinetic Energy decay over the realistic time scale that is observed in the atmosphere. During the intermediate and last stage of decay of the boundary-layer average Turbulent Kinetic Energy the exponents of the decay power law t go from 2 to 6, as evidenced by experimental results and recent analytical modeling in the surface layer.

  9. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1997-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements completed under this grant (NAGW-533), have shown that the opacity from, SO2 under simulated Venus conditions is best described by a different lineshape than was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  10. The Fuel Accident Condition Simulator (FACS) furnace system for high temperature performance testing of VHTR fuel

    SciTech Connect

    Paul A. Demkowicz; David V. Laug; Dawn M. Scates; Edward L. Reber; Lyle G. Roybal; John B. Walter; Jason M. Harp; Robert N. Morris

    2012-10-01

    The AGR-1 irradiation of TRISO-coated particle fuel specimens was recently completed and represents the most successful such irradiation in US history, reaching peak burnups of greater than 19% FIMA with zero failures out of 300,000 particles. An extensive post-irradiation examination (PIE) campaign will be conducted on the AGR-1 fuel in order to characterize the irradiated fuel properties, assess the in-pile fuel performance in terms of coating integrity and fission metals release, and determine the fission product retention behavior during high temperature safety testing. A new furnace system has been designed, built, and tested to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000 degrees C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, and Eu), iodine, and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator furnace system and the associated fission gas monitoring system, as well as preliminary system calibration results.

  11. Clinical audit of genetic testing and referral patterns for fragile X and associated conditions.

    PubMed

    Cotter, Megan; Archibald, Alison D; McClaren, Belinda J; Burgess, Trent; Francis, David; Hills, Louise; Martyn, Melissa; Oertel, Ralph; Slater, Howard; Cohen, Jonathan; Metcalfe, Sylvia A

    2016-06-01

    An audit was conducted of laboratory/clinical databases of genetic tests performed between January 2003 and December 2009, and for 2014, as well as referrals to the clinical service and a specialist multidisciplinary clinic, to determine genetic testing request patterns for fragile X syndrome and associated conditions and referrals for genetic counseling/multidisciplinary management in Victoria, Australia. An expanded allele (full mutation, premutation or intermediate) was found in 3.7% of tests. Pediatricians requested ∼70% of test samples, although fewer general practitioners and more obstetricians/gynecologists ordered tests in 2014. Median age at testing for individuals with a full mutation seeking a diagnosis without a fragile X family history was 4.3 years (males) and 9.4 years (females); these ages were lower when pediatricians ordered the tests (2.1 years and 6.1 years, respectively). Individuals with a premutation were generally tested at a later age (median age: males, 33.2 years; females, 36.4 years). Logistic regression showed that a family history of ID (OR 3.28 P = 0.005, CI 1.77-5.98) was the only indication to independently increase the likelihood of a test-positive (FM or PM) result. Following testing, ∼25% of full mutation or premutation individuals may not have attended clinical services providing genetic counseling or multidisciplinary management for these families. The apparent delay in fragile X syndrome diagnosis and lack of appropriate referrals for some may result in less than optimal management for these families. These findings suggest continued need for awareness and education of health professionals around diagnosis and familial implications of fragile X syndrome and associated conditions. © 2016 Wiley Periodicals, Inc.

  12. Predoctoral Dental Students' Perceptions of Dental Implant Training: Effect of Preclinical Simulation and Clinical Experience.

    PubMed

    Prasad, Soni; Bansal, Naveen

    2017-04-01

    The aims of this study were to assess 1) differences in perceptions of dental implant training between dental students who received didactic training alone (control group) and those who received didactic plus simulation training (test group); 2) differences in response between students with and without clinical experience in implant dentistry; and 3) the interaction effect of simulation training and clinical experience on students' satisfaction. A survey was distributed to the control group in 2014 and to the test group in 2015; both groups were at the same U.S. dental school. Data were collected on confidence levels with various implant restorative procedures along with overall satisfaction and number of implant restorations performed by each student. The response rate was 78.7% in the control group and 81.3% in the test group. In the control group, 85.7% of students reported being satisfied with implant training compared to 90.8% of students in the test group. The interaction effect of simulation training and clinical experience on overall student satisfaction was OR=1.5 at 95% CI: 0.8, 3.0. The students who had clinical experience with implant restorative procedures had significantly greater satisfaction than those who did not (OR=4.8, 95% CI: 2.1, 11.1, p<0.01). This study found that both the simulation and clinical experience affected these students' confidence and satisfaction levels with implant education: they were almost five times more satisfied with implant training when clinical experience in implant restorative procedures was a part of their implant education.

  13. Molecular Dynamics Simulation and Analysis of Interfacial Water at Selected Sulfide Mineral Surfaces under Anaerobic Conditions

    SciTech Connect

    Jin, Jiaqi; Miller, Jan D.; Dang, Liem X.

    2014-04-10

    In this paper, we report on a molecular dynamics simulation (MDS) study of the behavior of interfacial water at selected sulfide mineral surfaces under anaerobic conditions. The study revealed the interfacial water structure and wetting characteristics of the pyrite (100) surface, galena (100) surface, chalcopyrite (012) surface, sphalerite (110) surface, and molybdenite surfaces (i.e., the face, armchair-edge, and zigzag-edge surfaces), including simulated contact angles, relative number density profiles, water dipole orientations, hydrogen-bonding, and residence times. For force fields of the metal and sulfur atoms in selected sulfide minerals used in the MDS, we used the universal force field (UFF) and another set of force fields optimized by quantum chemical calculations for interactions with interfacial water molecules at selected sulfide mineral surfaces. Simulation results for the structural and dynamic properties of interfacial water molecules indicate the natural hydrophobic character for the selected sulfide mineral surfaces under anaerobic conditions as well as the relatively weak hydrophobicity for the sphalerite (110) surface and two molybdenite edge surfaces. Part of the financial support for this study was provided by the U.S. Department of Energy (DOE) under Basic Science Grant No. DE-FG-03-93ER14315. The Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences (BES), of the DOE, funded work performed by Liem X. Dang. Battelle operates Pacific Northwest National Laboratory for DOE. The calculations were carried out using computer resources provided by BES. The authors are grateful to Professor Tsun-Mei Chang for valuable discussions.

  14. Response of epilithic lichens to high temperatures at harsh natural and space simulated conditions

    NASA Astrophysics Data System (ADS)

    de La Torre, R.; Horneck, G.; Sancho, L.; Pintado, A.; Rabbow, E.; Scherer, K.; Facius, R.; Deutschmann, U.; Reina, M.

    Studies about the resistance of epilithic lichens to high temperature ranges are not very common until now. Research performed has been focused mainly on resistance of lichens to low temperatures, due the origin of most bipolar lichen species from Antarctica and from Arctic regions. The poiquilohidric nature of lichens gives them the possibility to adopt a latent status when environmental conditions are extreme, that is, when dryness, high solar UV radiation, and extreme temperatures exists, even when this state is long. When humidity returns, photosynthetic activity starts again. To determine the activity at high temperature conditions of the epilithic lichen Rhizocarpon geographicum, which grows at a high mountain region (Sierra de Gredos, Central Spain) with continental climate, we performed a campaign (29.07.03 - 31.07.03), selecting a period of maximal temperatures (July-August), and minimal humidity. Photosynthetic activity, measured with a fluorometer, preadapting and remoistering samples first, were very low or inexistent during this campaign, due to the high superficial temperatures of lichens rocks, minimal humidity values, and high intensities of UV solar irradiation. On the base of these data, we have selected this species as test system for space experiments (i.e. BIOPAN-4 and BIOPAN-5 missions of ESA). Before the BIOPAN-4 mission, the lichens were exposed to the different space parameters (space UV radiation, vaccum and high temperatures), simulated at the space simulation facilities of the Institute of Aerospace Medicine DLR (Germany). The further activity tests were done at the Universidad Complutense de Madrid. The results confirmed the high survival capacity of the selected lichens. We will show the results of photosynthetic activity after the space simulation tests as well as from the campaign performed at the Sierra de Gredos, in summer 2003.

  15. A cloud model simulation of space shuttle exhaust clouds in different atmospheric conditions

    NASA Technical Reports Server (NTRS)

    Chen, C.; Zak, J. A.

    1989-01-01

    A three-dimensional cloud model was used to characterize the dominant influence of the environment on the Space Shuttle exhaust cloud. The model was modified to accept the actual heat and moisture from rocket exhausts and deluge water as initial conditions. An upper-air sounding determined the ambient atmosphere in which the cloud could grow. The model was validated by comparing simulated clouds with observed clouds from four actual Shuttle launches. The model successfully produced clouds with dimensions, rise, decay, liquid water contents and vertical motion fields very similar to observed clouds whose dimensions were calculated from 16 mm film frames. Once validated, the model was used in a number of different atmospheric conditions ranging from very unstable to very stable. In moist, unstable atmospheres simulated clouds rose to about 3.5 km in the first 4 to 8 minutes then decayed. Liquid water contents ranged from 0.3 to 1.0 g kg-1 mixing ratios and vertical motions were from 2 to 10 ms-1. An inversion served both to reduce entrainment (and erosion) at the top and to prevent continued cloud rise. Even in the most unstable atmospheres, the ground cloud did not rise beyond 4 km and in stable atmospheres with strong low level inversions the cloud could be trapped below 500 m. Wind shear strongly affected the appearance of both the ground cloud and vertical column cloud. The ambient low-level atmospheric moisture governed the amount of cloud water in model clouds. Some dry atmospheres produced little or no cloud water. One case of a simulated TITAN rocket explosion is also discussed.

  16. THE REBOUND CONDITION OF DUST AGGREGATES REVEALED BY NUMERICAL SIMULATION OF THEIR COLLISIONS

    SciTech Connect

    Wada, Koji; Tanaka, Hidekazu; Yamamoto, Tetsuo; Suyama, Toru; Kimura, Hiroshi

    2011-08-10

    Collisional growth of dust aggregates is a plausible root of planetesimals forming in protoplanetary disks. However, a rebound of colliding dust aggregates prevents dust from growing into planetesimals. In fact, rebounding aggregates are observed in laboratory experiments but not in previous numerical simulations. Therefore, the condition of rebound between dust aggregates should be clarified to better understand the processes of dust growth and planetesimal formation. We have carried out numerical simulations of aggregate collisions for various types of aggregates and succeeded in reproducing a rebound of colliding aggregates under specific conditions. Our finding is that in the rebound process, the key factor of the aggregate structure is the coordination number, namely, the number of particles in contact with a particle. A rebound is governed by the energy dissipation along with restructuring of the aggregates and a large coordination number inhibits the restructuring at collisions. Results of our numerical simulation for various aggregates indicate that they stick to each other when the mean coordination number is less than 6, regardless of their materials and structures, as long as their collision velocity is less than the critical velocity for fragmentation. This criterion of the coordination number would correspond to a filling factor of {approx}0.3, which is somewhat larger than that reported in laboratory experiments. In protoplanetary disks, dust aggregates are expected to have low bulk densities (<0.1 g cm{sup -3}) during their growth, which would prevent dust aggregates from rebounding. This result supports the formation of planetesimals with direct dust growth in protoplanetary disks.

  17. Survivability of Psychrobacter cryohalolentis K5 under simulated martian surface conditions.

    PubMed

    Smith, David J; Schuerger, Andrew C; Davidson, Mark M; Pacala, Stephen W; Bakermans, Corien; Onstott, Tullis C

    2009-03-01

    Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25 degrees C for 24 h within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 h of exposure to Mars-normal conditions of 4.55 W/m(2) UVC irradiation (200-280 nm), -12.5 degrees C, 7.1 mbar, and a Mars gas mix composed of CO(2) (95.3%), N(2) (2.7%), Ar (1.6%), O(2) (0.2%), and H(2)O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at tau = 0.1 (dust-free CO(2) atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO(2)-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 h exposure period.

  18. Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions

    NASA Astrophysics Data System (ADS)

    Smith, David J.; Schuerger, Andrew C.; Davidson, Mark M.; Pacala, Stephen W.; Bakermans, Corien; Onstott, Tullis C.

    2009-03-01

    Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25°C for 24 h within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 h of exposure to Mars-normal conditions of 4.55 W/m2 UVC irradiation (200-280 nm), -12.5°C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H2O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at τ = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 h exposure period.

  19. Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions

    NASA Technical Reports Server (NTRS)

    Smith, David J.; Schuerger, Andrew C.; Davidson, Mark M.; Pacala, Stephen W.; Bakermans, Corien; Onstott, Tullis

    2008-01-01

    Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25 degrees C for 24 hr within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 hr of exposure to Mars-normal conditions of 4.55 W/m(2) UVC irradiation (200-280 nm), -12.5 degrees C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H(2)O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at tau = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 hr exposure period.

  20. Simulating crop growth with Expert-N-GECROS under different site conditions in Southwest Germany

    NASA Astrophysics Data System (ADS)

    Poyda, Arne; Ingwersen, Joachim; Demyan, Scott; Gayler, Sebastian; Streck, Thilo

    2016-04-01

    When feedbacks between the land surface and the atmosphere are investigated by Atmosphere-Land surface-Crop-Models (ALCM) it is fundamental to accurately simulate crop growth dynamics as plants directly influence the energy partitioning at the plant-atmosphere interface. To study both the response and the effect of intensive agricultural crop production systems on regional climate change in Southwest Germany, the crop growth model GECROS (YIN & VAN LAAR, 2005) was calibrated based on multi-year field data from typical crop rotations in the Kraichgau and Swabian Alb regions. Additionally, the SOC (soil organic carbon) model DAISY (MÜLLER et al., 1998) was implemented in the Expert-N model tool (ENGEL & PRIESACK, 1993) and combined with GECROS. The model was calibrated based on a set of plant (BBCH, LAI, plant height, aboveground biomass, N content of biomass) and weather data for the years 2010 - 2013 and validated with the data of 2014. As GECROS adjusts the root-shoot partitioning in response to external conditions (water, nitrogen, CO2), it is suitable to simulate crop growth dynamics under changing climate conditions and potentially more frequent stress situations. As C and N pools and turnover rates in soil as well as preceding crop effects were expected to considerably influence crop growth, the model was run in a multi-year, dynamic way. Crop residues and soil mineral N (nitrate, ammonium) available for the subsequent crop were accounted for. The model simulates growth dynamics of winter wheat, winter rape, silage maize and summer barley at the Kraichgau and Swabian Alb sites well. The Expert-N-GECROS model is currently parameterized for crops with potentially increasing shares in future crop rotations. First results will be shown.

  1. [Clinical course of asbestosis under the existing conditions in extraction and processing of serpentine asbestos].

    PubMed

    Likhacheva, E I; Semennikova, T K; Vagina, E R; Iarina, A L; Klimina, M S

    1999-01-01

    The authors followed changes in clinical course of asbestosis, comparing groups of individuals working in exposure to chrysotile-asbestos dust, patients having so-called late asbestosis and reference group (individuals with absent or minimal roentgenologic changes in lungs). Analysis of 530 case histories proved increase of average length of service in dusty conditions before asbestosis development, longer progression of pulmonary fibrosis. Asbestosis progression does not depend on medical resolutions. "Late" asbestosis occurs in retired workers who were engaged into auxiliary occupations. Low baseline values of respiratory function and associated respiratory infection worsen the overall prognosis.

  2. Simulation of clinical fractures for three different all-ceramic crowns

    PubMed Central

    Øilo, Marit; Kvam, Ketil; Gjerdet, Nils R

    2014-01-01

    Comparison of fracture strength and fracture modes of different all-ceramic crown systems is not straightforward. Established methods for reliable testing of all-ceramic crowns are not currently available. Published in-vitro tests rarely simulate clinical failure modes and are therefore unsuited to distinguish between the materials. The in-vivo trials usually lack assessment of failure modes. Fractographic analyses show that clinical crowns usually fail from cracks initiating in the cervical margins, whereas in-vitro specimens fail from contact damage at the occlusal loading point. The aim of this study was to compare three all-ceramic systems using a clinically relevant test method that is able to simulate clinical failure modes. Ten incisor crowns of three types of all-ceramic systems were exposed to soft loading until fracture. The initiation and propagation of cracks in these crowns were compared with those of a reference group of crowns that failed during clinical use. All crowns fractured in a manner similar to fracture of the clinical reference crowns. The zirconia crowns fractured at statistically significantly higher loads than alumina and glass-ceramic crowns. Fracture initiation was in the core material, cervically in the approximal areas. PMID:24698209

  3. Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions

    NASA Astrophysics Data System (ADS)

    Nagayama, T.; Bailey, J. E.; Loisel, G.; Rochau, G. A.; MacFarlane, J. J.; Golovkin, I.

    2016-02-01

    Recently, frequency-resolved iron opacity measurements at electron temperatures of 170-200 eV and electron densities of (0.7 - 4.0 )× 1022cm-3 revealed a 30 - 400 % disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015), 10.1038/nature14048]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. These simulations bridge the static-uniform picture of the data

  4. Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions.

    PubMed

    Nagayama, T; Bailey, J E; Loisel, G; Rochau, G A; MacFarlane, J J; Golovkin, I

    2016-02-01

    Recently, frequency-resolved iron opacity measurements at electron temperatures of 170-200 eV and electron densities of (0.7-4.0)×10(22)cm(-3) revealed a 30-400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. These simulations bridge the static-uniform picture of the data interpretation and the

  5. Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions

    DOE PAGES

    Nagayama, T.; Bailey, J. E.; Loisel, G.; ...

    2016-02-05

    Recently, frequency-resolved iron opacity measurements at electron temperatures of 170–200 eV and electron densities of (0.7 – 4.0) × 1022 cm–3 revealed a 30–400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproducemore » the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. Furthermore, these simulations bridge the static-uniform picture of the

  6. Growth and development in higher plants under simulated microgravity conditions on a 3-dimensional clinostat

    NASA Astrophysics Data System (ADS)

    Shimazu, T.; Yuda, T.; Miyamoto, K.; Yamashita, M.; Ueda, J.

    Growth and development of etiolated pea (Pisum sativum L. cv. Alaska) and maize (Zea mays L. cv. Golden Cross Bantam) seedlings grown under simulated microgravity conditions were intensively studied using a 3-dimensional clinostat as a simulator of weightlessness. Epicotyls of etiolated pea seedlings grown on the clinostat were the most oriented toward the direction far from cotyledons. Mesocotyls of etiolated maize seedlings grew at random and coleoptiles curved slightly during clinostat rotation. Clinostat rotation promoted the emergence of the 3rd internodes in etiolated pea seedlings, while it significantly inhibited the growth of the 1st internodes. In maize seedlings, the growth of coleoptiles was little affected by clinostat rotation, but that of mesocotyls was suppressed, and therefore, the emergence of the leaf out of coleoptile was promoted. Clinostat rotation reduced the osmotic concentration in the 1st internodes of pea seedlings, although it has little effect on the 2nd and the 3rd internodes. Clinostat rotation also reduced the osmotic concentrations in both coleoptiles and mesocotyls of maize seedlings. Cell-wall extensibilities of the 1st and the 3rd internodes of pea seedlings grown on the clinostat were significantly lower and higher as compared with those on 1 g conditions, respectively. Cell-wall extensibility of mesocotyls in seedlings grown on the clinostat also decreased. Changes in cell wall properties seem to be well correlated to the growth of each organ in pea and maize seedlings. These results suggest that the growth and development of plants is controlled under gravity on earth, and that the growth responses of higher plants to microgravity conditions are regulated by both cell-wall mechanical properties and osmotic properties of stem cells.

  7. Evaluation of an Electrochromic Device for Variable Emittance in Simulated Space Conditions

    NASA Astrophysics Data System (ADS)

    Puterbaugh, Rebekah L.; Mychkovsky, Alexander G.; Ponnappan, Rengasamy; Kislov, Nikolai

    2005-02-01

    Unprotected skin and external surfaces of a spacecraft in earth orbit may experience temperature variations from -50°C to +100°C during exposure to cold space or sun. As a result, thermal management of spacecraft becomes extremely important. One latest trend is to provide flexibility and control in the thermal design that involves variable emittance surfaces consisting of electrochromic (EC) coatings. For investigational purposes, a sample electrochromic device is evaluated for variable emittance in simulated space conditions. A vacuum chamber with a liquid nitrogen circulated blackbody shroud is employed to simulate space conditions. The 63.5 × 63.5 mm test sample supplied by a small business research firm is mounted on an aluminum plate heated by an electrical resistance heater. The sample is thermally insulated by a heat shield from all surroundings excluding the active front surface facing the shroud. The heat shield is uniformly maintained at the sample temperature using an independent circuit of resistance heaters and temperature controllers. A steady state energy balance is applied to the test sample to determine the emittance as a function of temperature and DC bias voltage applied across the anode and cathode. Tests were performed to verify the switchability from high to low emittance states and vice versa. The difference between the high and low emittance values (Δɛ) obtained in the present calorimetric measurement is compared with the data obtained from FTIR measurements performed by the supplier of the EC sample. Results obtained in the present experiments compare closely with supplier data and prove the effectiveness of the variable emittance sample in space conditions. The validity of the calorimetric experiment is confirmed by testing materials with known emittances, such as black paint and polished metals. Error analysis of the system predicts an emittance accuracy of ±5% at sample temperatures in the range of -50°C to 100°C.

  8. Green tea increases the survival yield of Bifidobacteria in simulated gastrointestinal environment and during refrigerated conditions

    PubMed Central

    2012-01-01

    Background The well–known prebiotics are carbohydrates but their effects may not always be beneficial, as they can also encourage the growth of non-probiotic bacteria such as Eubacterium biforme and Clostridium perfringens. Therefore, new alternatives such as non-carbohydrate sources to stimulate the growth of probiotics are needed. The aim of this work was to evaluate (I) the green tea polyphenols by HPLC-LC/MS and (II) the protective effect of green tea extract on viability and stability of B. infantis ATCC 15697 and B. breve ATCC 15700 microencapsulated in chitosan coated alginate microcapsules during exposure to simulated gastrointestinal conditions and refrigerated storage. Results The major compound identified by HPLC-LC/MS in green tea was epigallocatechin gallate followed by caffeine and epigallocatechin. The survival yield of probiotic bacteria in microcapsules with 10% GT during storage at 4°C, demonstrated significantly (P < 0.05) higher number of survival bacteria. Microencapsulated B.infantis and B. breve with 5% and 10% GT showed a significantly (P < 0.05) improved survival under simulated gastric conditions (pH 2.0, 2 h) and bile solution (3%, 2 h) when they were compared with microencapsulation without GT addition. Conclusions The results of this study suggest that green tea coencapsulated with B. infantis or B. breve exert a protective effect of bacteria during exposure to gastrointestinal conditions and refrigerated storage. For a health perspective, the results confirm the growing interest probiotic bacteria and the perceived benefit of increasing their numbers in the gastrointestinal tract by microencapsulation. PMID:22727242

  9. Clinical applications of a CT-simulator: precision treatment planning and portal marking in breast cancer.

    PubMed

    Heidtman, C M

    1990-01-01

    Breast cancer is frequently treated with radiation using opposed tangent portals to the involved breast, including the chest wall. Presented is a method for simulating such treatment fields on a CT simulator. A short series of CT images provides a three dimensional model for treatment planning prior to marking the patient. Gantry and collimator angles, as well as wedges or custom blocks, are determined in the planning stage. Upon receipt of an approved treatment plan, the portals are available for simulation. The cross-hair laser and computerized bed movement in the CT simulator aid in marking the entrance of the radiation fields on the patient's skin. Discussion of the clinical application of the described technique is included.

  10. Efficacy of ozonized olive oil in the management of oral lesions and conditions: A clinical trial

    PubMed Central

    Kumar, Tarun; Arora, Neha; Puri, Gagan; Aravinda, Konidena; Dixit, Avani; Jatti, Deepa

    2016-01-01

    The oral cavity is an open ecosystem that shows a dynamic balance between the entrance of microorganisms (bacterial, viral or fungal), colonization modalities, nutritional balance, and host defenses against their removal. The oral lesions including aphthous ulcerations, herpes labialis, oral candidiasis, oral lichen planus, and angular cheilitis some of the common entities encountered in the clinical practice. A variety of treatment options is available in the literature for all of these lesions and conditions. Topical ozone therapy is a minimally invasive technique that can be used for these conditions without any side effects. Aim and Objectives: To evaluate the efficacy of ozonized olive oil in the treatment of oral lesions and conditions. Materials and Methods: A longitudinal study was carried out on 50 patients (aphthous ulcerations, herpes labialis, oral candidiasis, oral lichen planus, and angular cheilitis). The ozonized olive oil was applied twice daily until the lesion regresses for a maximum of 6 months. Results: All the lesions regress in patients with aphthous ulcerations, herpes labialis, oral candidiasis and angular cheilitis or showed improvement in the signs and symptoms in oral lichen planus patients. No toxicity or side effect was observed in any of the patients. Conclusion: Ozone therapy though requires a gaseous form to be more effective, but topical form can also bring out the positive results without any toxicity or side effect. Hence, it can be considered as a minimally invasive therapy for the oral infective and immunological conditions. PMID:27041901

  11. Clinical performance and skill retention after simulation-based education for nephrology fellows.

    PubMed

    Ahya, Shubhada N; Barsuk, Jeffrey H; Cohen, Elaine R; Tuazon, Jennifer; McGaghie, William C; Wayne, Diane B

    2012-07-01

    We previously demonstrated that simulation-based education (SBE) improved temporary hemodialysis catheter (THDC) insertion skills by nephrology fellows. SBE, featuring deliberate practice and rigorous achievement standards, was a powerful method to enhance THDC insertion skills in nephrology fellows. However, experts have called for further research to evaluate skill transfer from the simulated environment to actual clinical care and skill retention. This is a prospective observational cohort study of THDC insertion skills. Twelve nephrology fellows from three academic centers in Chicago were evaluated using a skills checklist from July 2008 to June 2009. Simulator-trained fellows were tested after the SBE intervention and expected to meet or exceed a minimum passing score (MPS) set by an expert panel. To assess transfer of skill to clinical care, three simulator-trained fellows were assessed at 6 months on actual patient THDC insertions using the checklist. To assess retention of skill, 11 of 12 simulator-trained fellows were reassessed at 1 year using the checklist and central venous catheter simulator. Outcomes were determined by THDC insertion skill performance. Simulator-trained fellows scored similarly during 6-month THDC insertions on actual patients and immediate posttest (M = 86.2%, SD = 22.3% vs. M = 93.5%, SD = 5.3%, p = 0.32). However, 1 year after SBE, simulated THDC insertion scores were significantly lower than at immediate posttest (M = 73.4%, SD = 22.2% vs. M = 93.5%, SD = 5.3%, p = 0.01). Our results show that nephrology fellows who completed SBE displayed high levels of performance during THDC insertions on actual patients 6 months later. At 1 year, there was statistically significant skills decay. We recommend booster training at 6 months.

  12. Mercury Conditions for the MESSENGER Mission Simulated in High- Solar-Radiation Vacuum Tests

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2003-01-01

    The MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) spacecraft, planned for launch in March 2004, will perform two flybys of Mercury before entering a year-long orbit of the planet in September 2009. The mission will provide opportunities for detailed characterization of the surface, interior, atmosphere, and magnetosphere of the closest planet to the Sun. The NASA Glenn Research Center and the MESSENGER spacecraft integrator, the Johns Hopkins University Applied Physics Laboratory, have partnered under a Space Act Agreement to characterize a variety of critical components and materials under simulated conditions expected near Mercury. Glenn's Vacuum Facility 6, which is equipped with a solar simulator, can simulate the vacuum and high solar radiation anticipated in Mercury orbit. The MESSENGER test hardware includes a variety of materials and components that are being characterized during the Tank 6 vacuum tests, where the hardware will be exposed to up to 11 suns insolation, simulating conditions expected in Mercury orbit. In 2002, ten solar vacuum tests were conducted, including beginning of life, end of life, backside exposure, and solar panel thermal shock cycling tests. Components tested include candidate solar array panels, sensors, thermal shielding materials, and communication devices. As an example, for the solar panel thermal shock cycling test, two candidate solar array panels were suspended on a lift mechanism that lowered the panels into a liquid-nitrogen-cooled box. After reaching -140 C, the panels were then lifted out of the box and exposed to the equivalent of 6 suns (8.1 kilowatts per square meters). After five cold soak/heating cycles were completed successfully, there was no apparent degradation in panel performance. An anticipated 100-hr thermal shield life test is planned for autumn, followed by solar panel flight qualification tests in winter. Glenn's ongoing support to the MESSENGER program has been instrumental in

  13. Plasma ionization under simulated ambient Mars conditions for quantification of methane by mass spectrometry.

    PubMed

    Taghioskoui, Mazdak; Zaghloul, Mona

    2016-04-07

    Ambient ionization techniques enable ion production in the native sample environment for mass spectrometry, without a need for sample preparation or separation. These techniques provide superior advantages over conventional ionization methods and are well developed and investigated for various analytical applications. However, employing ambient ionization techniques for in situ extra-terrestrial chemical analysis requires these techniques to be designed and developed according to the ambient conditions of extra-terrestrial environments, which substantially differ from the ambient conditions of Earth. Here, we report a plasma ionization source produced under simulated ambient Mars conditions for mass spectrometry. The plasma ionization source was coupled to a quadrupole mass spectrometer, and quantitative and qualitative analyses of trace amounts of methane, as an analyte of interest in Mars discovery missions, were demonstrated. The miniature plasma source was operational at a net power as low as ∼1.7 W in the pressure range of 4-16 Torr. A detection limit as low as ∼0.15 ppm (v/v) at 16 Torr for methane was demonstrated.

  14. Factors limiting endurance of armor, artillery, and infantry units under simulated NBC conditions

    SciTech Connect

    Rauch, T.M.; Tharion, W.J.; Banderet, L.E.; Lussier, A.R.

    1986-03-13

    The war of the future will require 72-hour operations in environments contaminated with nuclear/biological/chemical (NBC) agents. The 1985 P2NBC2 (Physiological and Psychological Effects of NBC and Extended Operations on Combined Arms Crews) Program assessed soldier endurance and performance under simulated NBC conditions. A total of 175 soldiers were observed during four tests differing in design, site, climatic conditions, and performance demands. In all but one of the iterations where the full chemical-protective ensemble (MOPP 4) was used without cooling, soldier endurance fell far short of the projected requirement. Psychological data were analyzed to determine which factors were associated with the incidence of casualties. The findings showed that perceived intensity of symptoms resembling the hyperventilation syndrome was significantly greater in soldiers classified as Casualties. Five of these symptoms (painful breathing, difficulty breathing, shortness of breath, headache, and nausea) showed Casualty-Survivor differences in all tests. Symptom intensity was attributed to two factors. (1) External conditions. Thermal stress exacerbated the five basic symptoms, induced others (tetany and paresthesia), and decreased endurance. Periodic relief from respirator use attenuated these symptoms and enhanced endurance. (2) Individual differences. Significant Casualty-Survivor differences in anxiety, depression, and cognitive strategy scores indicated that perception of hyperventilation symptoms and endurance were related to personality variables. Hyperventilation symptoms could incapacitate the soldier or induce removal of the protective mask under actual chemical attack.

  15. Water retention of selected microorganisms and Martian soil simulants under close to Martian environmental conditions

    NASA Astrophysics Data System (ADS)

    Jänchen, J.; Bauermeister, A.; Feyh, N.; de Vera, J.-P.; Rettberg, P.; Flemming, H.-C.; Szewzyk, U.

    2014-08-01

    Based on the latest knowledge about microorganisms resistant towards extreme conditions on Earth and results of new complex models on the development of the Martian atmosphere we quantitatively examined the water-bearing properties of selected extremophiles and simulated Martian regolith components and their interaction with water vapor under close to Martian environmental conditions. Three different species of microorganisms have been chosen and prepared for our study: Deinococcus geothermalis, Leptothrix sp. OT_B_406, and Xanthoria elegans. Further, two mineral mixtures representing the early and the late Martian surface as well as montmorillonite as a single component of phyllosilicatic minerals, typical for the Noachian period on Mars, were selected. The thermal mass loss of the minerals and bacteria-samples was measured by thermoanalysis. The hydration and dehydration properties were determined under close to Martian environmental conditions by sorption isotherm measurements using a McBain-Bakr quartz spring balance. It was possible to determine the total water content of the materials as well as the reversibly bound water fraction as function of the atmospheres humidity by means of these methods. Our results are important for the evaluation of future space mission outcomes including astrobiological aspects and can support the modeling of the atmosphere/surface interaction by showing the influence on the water inventory of the upper most layer of the Martian surface.

  16. Effects of light condition after simulated acid snow stress on leaves of winter wheat.

    PubMed

    Inada, Hidetoshi; Fujikawa, Seizo; Saito, Hideyuki; Arakawa, Keita

    2007-01-01

    Winter plants regrow after freeze-thawing in acidic meltwater from the acid-snow layer in early winter or early spring. In this study, the responses of cold-acclimated wheat seedlings to different light conditions during the regrowth period after simulated acid snow (SAS) stress were investigated. After freeze-thawing in sulfuric acid (SAS stress) of pH 2.0, dry weight and the maximal quantum yield of photosystem II (PSII) decreased more in mature leaves than in young leaves. In a subsequent regrowth period under light condition, dry weight, relative water content, and the maximal quantum yield of PSII were severely affected in mature leaves but were only slightly affected in SAS (pH 2.0)-stressed young leaves. The levels of membrane lipid peroxidation and hydrogen peroxide in mature leaves of SAS (pH 2.0)-stressed seedlings were significantly higher than those in young leaves during the regrowth period under light condition. The superoxide dismutase activity in young leaves was higher than that in mature leaves during the regrowth period. These results indicate that mature leaves of seedlings during the snow melt season are more sensitive than young leaves to photooxidative stress because of their low acid snow stress tolerance and low capacity for the detoxification of superoxide.

  17. Degradation of tocopherols during rapeseed storage in simulated conditions of industrial silos

    NASA Astrophysics Data System (ADS)

    Gawrysiak-Witulska, Marzena; Siger, Aleksander; Rusinek, Robert

    2016-01-01

    The investigations consisted in laboratory simulation of conditions prevailing in the real ecosystem in an industrial rapeseed storage facility. The aim of the study was to assess the impact of temperature, moisture, and static pressure on degradation of tocopherols contained in rapeseed. Rapeseed varieties with high oil content were analysed in the investigations. Samples of seeds with 7, 10, 13, and 16% moisture levels were stored at a temperature of 25, 30, and 35°C in specially designed airtight pressure silos for storage in controlled conditions. During the storage, the seeds were subjected to overpressure in the range of 20-60 kPa. The seeds were stored in these conditions for 28 days. It was demonstrated that primarily moisture induced the greatest loss of the total content of tocopherol and its α-T and γ-T homologues, followed by temperature and, to a lesser extent, pressure. In addition, the results obtained showed that, in the case of seeds characterised by higher moisture levels (13 and 16%), an increase in the storage temperature in the range of 25-30°C rather than 30-35°C intensified tocopherol loss more efficiently.

  18. Operant conditioning of spinal reflexes: from basic science to clinical therapy

    PubMed Central

    Thompson, Aiko K.; Wolpaw, Jonathan R.

    2014-01-01

    New appreciation of the adaptive capabilities of the nervous system, recent recognition that most spinal cord injuries are incomplete, and progress in enabling regeneration are generating growing interest in novel rehabilitation therapies. Here we review the 35-year evolution of one promising new approach, operant conditioning of spinal reflexes. This work began in the late 1970’s as basic science; its purpose was to develop and exploit a uniquely accessible model for studying the acquisition and maintenance of a simple behavior in the mammalian central nervous system (CNS). The model was developed first in monkeys and then in rats, mice, and humans. Studies with it showed that the ostensibly simple behavior (i.e., a larger or smaller reflex) rests on a complex hierarchy of brain and spinal cord plasticity; and current investigations are delineating this plasticity and its interactions with the plasticity that supports other behaviors. In the last decade, the possible therapeutic uses of reflex conditioning have come under study, first in rats and then in humans. The initial results are very exciting, and they are spurring further studies. At the same time, the original basic science purpose and the new clinical purpose are enabling and illuminating each other in unexpected ways. The long course and current state of this work illustrate the practical importance of basic research and the valuable synergy that can develop between basic science questions and clinical needs. PMID:24672441

  19. Identification and Quantitation of the Microbiological Flora of the Food Packet, Long Range Patrol under Simulated Field Conditions,

    DTIC Science & Technology

    simulating actual storage conditions. The predominating organisms isolated and identified from the rations were aerobic spore-formers, coagulase - negative ...within two hours of rehydration; and 2. that improved methods of detecting coagulase -positive staphylococci be investigated. (Author)

  20. Numerical simulation of the thermal conditions in a sea bay water area used for water supply to nuclear power plants

    SciTech Connect

    Sokolov, A. S.

    2013-07-15

    Consideration is given to the numerical simulation of the thermal conditions in sea water areas used for both water supply to and dissipation of low-grade heat from a nuclear power plant on the shore of a sea bay.

  1. A systems engineering approach to validation of a pulmonary physiology simulator for clinical applications

    PubMed Central

    Das, A.; Gao, Z.; Menon, P. P.; Hardman, J. G.; Bates, D. G.

    2011-01-01

    Physiological simulators which are intended for use in clinical environments face harsh expectations from medical practitioners; they must cope with significant levels of uncertainty arising from non-measurable parameters, population heterogeneity and disease heterogeneity, and their validation must provide watertight proof of their applicability and reliability in the clinical arena. This paper describes a systems engineering framework for the validation of an in silico simulation model of pulmonary physiology. We combine explicit modelling of uncertainty/variability with advanced global optimization methods to demonstrate that the model predictions never deviate from physiologically plausible values for realistic levels of parametric uncertainty. The simulation model considered here has been designed to represent a dynamic in vivo cardiopulmonary state iterating through a mass-conserving set of equations based on established physiological principles and has been developed for a direct clinical application in an intensive-care environment. The approach to uncertainty modelling is adapted from the current best practice in the field of systems and control engineering, and a range of advanced optimization methods are employed to check the robustness of the model, including sequential quadratic programming, mesh-adaptive direct search and genetic algorithms. An overview of these methods and a comparison of their reliability and computational efficiency in comparison to statistical approaches such as Monte Carlo simulation are provided. The results of our study indicate that the simulator provides robust predictions of arterial gas pressures for all realistic ranges of model parameters, and also demonstrate the general applicability of the proposed approach to model validation for physiological simulation. PMID:20538754

  2. Development of Microcomputer Methods for Analysis and Simulation of Clinical Pharmacokinetic Data Relevant to New Drug Development.

    DTIC Science & Technology

    1985-08-02

    interpretation, and simulation of pharmacokinetic data, dose - response kinetic data, and other data relevant to new drug development, for use with the Tektronix...Statistical Programs for Clinical Pharmacological Problems; Keywords: Clinical Pharmacokinetics, Dose - Response Relations, Pharmakinetic Simulation, Non-Parametric Statistics, Mefloquine, Microcomputer Graphics, Tektronix 4052.

  3. Blueberry proanthocyanidins against human norovirus surrogates in model foods and under simulated gastric conditions.

    PubMed

    Joshi, Snehal; Howell, Amy B; D'Souza, Doris H

    2017-05-01

    Blueberry proanthocyanidins (B-PAC) are known to decrease titers of human norovirus surrogates in vitro. The application of B-PAC as therapeutic or preventive options against foodborne viral illness needs to be determined using model foods and simulated gastric conditions in vitro. The objective of this study was to evaluate the antiviral effect of B-PAC in model foods (apple juice (AJ) and 2% reduced fat milk) and simulated gastrointestinal fluids against cultivable human norovirus surrogates (feline calicivirus; FCV-F9 and murine norovirus; MNV-1) over 24 h at 37 °C. Equal amounts of each virus (5 log PFU/ml) was mixed with B-PAC (1, 2 and 5 mg/ml) prepared either in AJ, or 2% milk, or simulated gastric fluids and incubated over 24 h at 37 °C. Controls included phosphate buffered saline, malic acid (pH 7.2), AJ, 2% milk or simulated gastric and intestinal fluids incubated with virus over 24 h at 37 °C. The tested viruses were reduced to undetectable levels within 15 min with B-PAC (1, 2 and 5 mg/ml) in AJ (pH 3.6). However, antiviral activity of B-PAC was reduced in milk. FCV-F9 was reduced by 0.4 and 1.09 log PFU/ml with 2 and 5 mg/ml B-PAC in milk, respectively and MNV-1 titers were reduced by 0.81 log PFU/ml with 5 mg/ml B-PAC in milk after 24 h. B-PAC at 5 mg/ml in simulated intestinal fluid reduced titers of the tested viruses to undetectable levels within 30 min. Overall, these results show the potential of B-PAC as preventive and therapeutic options for foodborne viral illnesses.

  4. Kelvin-Helmholtz instability during northward IMF conditions: Global 3-Dimensional MHD simulations (Invited)

    NASA Astrophysics Data System (ADS)

    Merkin, V. G.; Lyon, J.; Claudepierre, S. G.

    2013-12-01

    The Kelvin-Helmholtz Instability (KHI) has long been suggested to operate on the magnetospheric boundary, where the magnetosheath plasma streams past the magnetosphere. The instability is thought to be responsible for inducing various wave populations in the magnetosphere and for mass, momentum and energy transport across the magnetospheric boundary. Waves attributed to the KHI have been observed at the Earth's magnetosphere flanks as well as at Saturn and Mercury during spacecraft crossings, and remotely at boundaries of Coronal Mass Ejections (CMEs). Recent high-resolution global 3D magnetohydrodynamic (MHD) simulations of the magnetosphere confirm the existence of pronounced perturbations of the magnetospheric boundary, which are thought to be due to KHI. Such global simulations had been challenging in the past because of the need to encompass the entire magnetosphere, while sufficiently resolving the boundary layer. Here we present results of such a high-resolution simulation of the magnetosphere, using the Lyon-Fedder-Mobarry (LFM) model, under steady northward Interplanetary Magnetic Field (IMF) conditions. We find the magnetospheric boundary to be globally unstable, including the high-latitude boundary layer (meridional plane), where magnetic tension is apparently not sufficient to stabilize the growth of oscillations. Roughly beyond the terminator, global modes, coupled into the surface modes, become apparent, so that the entire body of the magnetosphere is engaged in an oscillatory motion. The wave vector of the surface oscillations has a component perpendicular to the background flow and tangential to the shear layer (in the equatorial plane, k_z component of the wave vector), which is consistent with the generation of field-aligned currents that flow on closed field lines between the inner portion of the boundary layer and the ionosphere. We calculate the distribution of wave power in the equatorial plane and find it consistent with the existence of a

  5. Simulation of Surface-Water Conditions in the Nontidal Passaic River Basin, New Jersey

    USGS Publications Warehouse

    Spitz, Frederick J.

    2007-01-01

    The Passaic River Basin, the third largest drainage basin in New Jersey, encompasses 950 mi2 (square miles) in the highly urbanized area outside New York City, with a population of 2 million. Water quality in the basin is affected by many natural and anthropogenic factors. Nutrient loading to the Wanaque Reservoir in the northern part of the basin is of particular concern and is caused partly by the diversion of water at two downstream intakes that is transferred back upstream to refill the reservoir. The larger of these diversions, Wanaque South intake, is on the lower Pompton River near Two Bridges, New Jersey. To support the development of a Total Maximum Daily Load (TMDL) for nutrients in the nontidal part of the basin (805 mi2), a water-quality transport model was needed. The U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection and New Jersey EcoComplex, developed a flow-routing model to provide the hydraulic inputs to the water-quality model. The Diffusion Analogy Flow model (DAFLOW) described herein was designed for integration with the Water Quality Analysis Simulation Program (WASP) watershed water-quality model. The flow routing model was used to simulate flow in 108 miles of the Passaic River and major tributaries. Flow data from U.S. Geological Survey streamflow-gaging stations represent most of the model's upstream boundaries. Other model inputs include estimated flows for ungaged tributaries and unchanneled drainage along the mainstem, and reported flows for major point-source discharges and diversions. The former flows were calibrated using the drainage-area ratio method. The simulation extended over a 4+ year period representing a range in flow conditions. Simulated channel cross-sectional geometry in the DAFLOW model was calibrated using several different approaches by adjusting area and top width parameters. The model also was calibrated to observed flows for water year 2001 (low flow) at five mainstem

  6. Oxidative Dissolution of Uraninite in the Presence of Mackinawite (FeS) under Simulated Groundwater Conditions

    NASA Astrophysics Data System (ADS)

    Bi, Y.; Hyun, S.; Hayes, K. F.

    2010-12-01

    Redox conditions can have a strong impact on the fate of a redox-sensitive radionuclide, such as uranium. Field studies have suggested using biogeochemical manipulation of the redox conditions to convert dissolved U(VI) species, stable under oxic conditions, to less soluble reduced U(IV) solids in U-contaminated groundwater. This is one strategy being considered for the long-term sequestration of U in contaminated groundwater environments. However, the re-exposure of reduced U(IV) solids to oxic environments may release U back into the water phase and greatly increase its mobility. Previous work has demonstrated the potential for iron sulfides created under sulfate reducing conditions to retard the re-oxidation of reduced U solids providing the motivation for this study. In this work, the impact of mackinawite (FeS) on the oxidation of nanoscale uraninite (UO2+x(s)) by dissolved oxygen was experimentally studied to investigate its role in slowing the oxidation of the reduced U solid under simulated groundwater conditions. The oxidation kinetic profiles of synthetic uraninite and mackinawite were monitored as a function of time with respect to both aqueous- and solid-phase oxidation products in batch reactors. The solid-phase reaction products were further characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. The results show that mackinawite protects uraninite from rapid oxidation by dissolved oxygen for up to 60 hr, keeping dissolved U below 0.4 µM as long as sufficient dissolved Fe(II) is present. Meanwhile, dissolved sulfide is also oxidized to form elemental sulfur, suggesting a role of sulfide in maintaining reducing conditions. As the oxidation proceeds, dissolved Fe(II) concentrations diminish to near the detection limit, along with the formation of mixed-Fe(III) (hydr)oxides of lepidocrocite and goethite. However, when most mackinawite has been converted to Fe(III) oxide solids after significant oxidation

  7. Surrogate fuel assembly multi-axis shaker tests to simulate normal conditions of rail and truck transport

    SciTech Connect

    McConnell, Paul E.; Koenig, Greg John; Uncapher, William Leonard; Grey, Carissa; Engelhardt, Charles; Saltzstein, Sylvia J.; Sorenson, Ken B.

    2016-05-01

    This report describes the third set of tests (the “DCLa shaker tests”) of an instrumented surrogate PWR fuel assembly. The purpose of this set of tests was to measure strains and accelerations on Zircaloy-4 fuel rods when the PWR assembly was subjected to rail and truck loadings simulating normal conditions of transport when affixed to a multi-axis shaker. This is the first set of tests of the assembly simulating rail normal conditions of transport.

  8. Perceived Benefits of Pre-Clinical Simulation-based Training on Clinical Learning Outcomes among Omani Undergraduate Nursing Students

    PubMed Central

    Madhavanprabhakaran, Girija; Al-Khasawneh, Esra; Wittmann, Lani

    2015-01-01

    Objectives: This study aimed to explore the benefits perceived by Omani undergraduate maternity nursing students regarding the effect of pre-clinical simulation-based training (PSBT) on clinical learning outcomes. Methods: This non-experimental quantitative survey was conducted between August and December 2012 among third-year baccalaureate nursing students at Sultan Qaboos University in Muscat, Oman. Voluntary participants were exposed to faculty-guided PSBT sessions using low- and medium-fidelity manikins, standardised scenarios and skill checklists on antenatal, intranatal, postnatal and newborn care and assessment. Participants answered a purposely designed self-administered questionnaire on the benefits of PSBT in enhancing learning outcomes. Items were categorised into six subscales: knowledge, skills, patient safety, academic safety, confidence and satisfaction. Scores were rated on a four-point Likert scale. Results: Of the 57 participants, the majority (95.2%) agreed that PSBT enhanced their knowledge. Most students (94.3%) felt that their patient safety practices improved and 86.5% rated PSBT as beneficial for enhancing skill competencies. All male students and 97% of the female students agreed that PSBT enhanced their confidence in the safe holding of newborns. Moreover, 93% of participants were satisfied with PSBT. Conclusion: Omani undergraduate nursing students perceived that PSBT enhanced their knowledge, skills, patient safety practices and confidence levels in providing maternity care. These findings support the use of simulation training as a strategy to facilitate clinical learning outcomes in future nursing courses in Oman, although further research is needed to explore the objective impact of PSBT on learning outcomes. PMID:25685368

  9. Clinical studies with disposable diapers containing absorbent gelling materials: evaluation of effects on infant skin condition.

    PubMed

    Campbell, R L; Seymour, J L; Stone, L C; Milligan, M C

    1987-12-01

    Disposable infant diapers with absorbent gelling material (cross-linked sodium polyacrylates) incorporated into the core were clinically evaluated for their effect on infant skin condition. Absorbent gelling materials tightly hold water and provide pH control by a buffering capacity as well as by helping to segregate urine apart from feces. Four clinical studies were conducted with each following a rigid protocol that controlled for variables of diet and age in addition to the diaper material that may influence the development of diaper dermatitis and helped to control for any inherent bias in the study. This allowed for the controlled assessment of skin condition with respect to diaper type. Absorbent gelling material-containing disposable, conventional (100% cellulose core) disposable, and home-laundered cloth diapers were test products. In these studies 1614 infants were initially enrolled with 522 of them assigned to absorbent gelling material disposable, 738 to conventional disposable, and 354 to home-laundered cloth diapers. Objective measurements of skin wetness (transepidermal water loss) and skin pH, as well as double-blind grading of diaper dermatitis, were the measures of skin condition. Absorbent gelling material disposable diapers were associated with significantly reduced skin wetness, closer to normal skin pH, and lower degrees of diaper dermatitis when compared to conventional disposable or home-laundered cloth diapers. The results are consistent with the hypothesis that better control in the diaper area of skin wetness, skin pH, and the prevention of the mixing of urine and feces produces a better diaper environment.

  10. [EEG-correlates of pilots' functional condition in simulated flight dynamics].

    PubMed

    Kiroy, V N; Aslanyan, E V; Bakhtin, O M; Minyaeva, N R; Lazurenko, D M

    2015-01-01

    The spectral characteristics of the EEG recorded on two professional pilots in the simulator TU-154 aircraft in flight dynamics, including takeoff, landing and horizontal flight (in particular during difficult conditions) were analyzed. EEG recording was made with frequency band 0.1-70 Hz continuously from 15 electrodes. The EEG recordings were evaluated using analysis of variance and discriminant analysis. Statistical significant of the identified differences and the influence of the main factors and their interactions were evaluated using Greenhouse - Gaiser corrections. It was shown that the spectral characteristics of the EEG are highly informative features of the state of the pilots, reflecting the different flight phases. High validity ofthe differences including individual characteristic, indicates their non-random nature and the possibility of constructing a system of pilots' state control during all phases of flight, based on EEG features.

  11. Testing of Icy-Soil Sample Delivery in Simulated Martian Conditions (Animation)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This movie clip shows testing under simulated Mars conditions on Earth in preparation for NASA's Phoenix Mars Lander using its robotic arm for delivering a sample to the doors of a laboratory oven.

    The icy soil used in the testing flowed easily from the scoop during all tests at Martian temperatures. On Mars, icy soil has stuck to the scoop, a surprise that may be related to composition of the soil at the landing site.

    This testing was done at Honeybee Robotics Spacecraft Mechanisms Corp., New York, which supplied the Phoenix scoop.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASAaE(TM)s Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  12. Structure and density of basaltic melts at mantle conditions from first-principles simulations

    PubMed Central

    Bajgain, Suraj; Ghosh, Dipta B.; Karki, Bijaya B.

    2015-01-01

    The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our results suggest that as pressure increases, all types of coordination between major cations and anions strongly increase, and the water speciation changes from isolated species to extended forms. These structural changes are responsible for rapid initial melt densification on compression thereby making these basaltic melts possibly buoyantly stable at one or more depths. Our finding that the melt-water system is ideal (nearly zero volume of mixing) and miscible (negative enthalpy of mixing) over most of the mantle conditions strengthens the idea of potential water enrichment of deep-mantle melts and early magma ocean. PMID:26450568

  13. STARDUST: A simulation experiment of cosmic dust analogues production in microgravity conditions

    NASA Technical Reports Server (NTRS)

    Ferguson, Frank; Lilleleht, Lembit U.; Nuth, J.; Stephens, J. R.; Bussoletti, E.; Carotenuto, L.; Colangeli, L.; Dellaversana, P.; Mele, F.; Mennella, V.

    1992-01-01

    The aim, activity, and some preliminary results of the STARDUST program are presented. The condensation of solid materials from the vapor phase is important in several scientific fields such as chemical vapor deposition, air pollution, and the formation of refractory cosmic dust around stars. Conventional studies of refractory grain formation, using high temperature furnace and shock tube techniques, are restricted to short time scales and suffer from buoyancy induced convection that limit their accuracy. In order to simulate more accurately the condensation of refractory grains near stars and to investigate the advantages of performing condensation studies in microgravity conditions, an experimental investigation of vapor phase condensation in microgravity was undertaken. The experimental equipment currently used is reported. The results from the first flight series and particle aggregation modeling efforts are presented.

  14. STARDUST - A simulation experiment of cosmic dust analogues production in microgravity conditions

    NASA Technical Reports Server (NTRS)

    Ferguson, Frank T.; Lilleleht, L. U.; Nuth, J.; Stephens, J. R.; Bussoletti, E.; Carotenuto, L.; Colangeli, L.; Dell'aversana, P.; Mele, F.; Mennella, V.

    1993-01-01

    The condensation of solid materials from the vapor phase is important in several scientific fields such as chemical vapor deposition, air pollution and the formation of refractory cosmic dust around stars. Conventional studies of refractory grain formation, using high temperature furnace and shock tube techniques, are restricted to short time scales and suffer from buoyancy induced convection that limit their accuracy. In order to simulate more accurately the condensation of refractory grains near stars and to investigate the advantages of performing condensation studies in microgravity conditions, an experimental investigation was undertaken. This work reports the experimental equipment currently used. The results from the first flight series and particle aggregation modelling efforts are presented briefly.

  15. Growth and Survival of Some Probiotic Strains in Simulated Ice Cream Conditions

    NASA Astrophysics Data System (ADS)

    Homayouni, A.; Ehsani, M. R.; Azizi, A.; Razavi, S. H.; Yarmand, M. S.

    A Completely Randomized Design (CRD) experiment was applied in triplicates to evaluate the survival of four probiotic strains in simulated ice cream conditions. The growth and survival rate of these probiotic strains (Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium longum) in varying amount of sucrose (10, 15, 20 and 25%), oxygen scavenging components (0.05% L-cysteine and 0.05% L-ascorbate) and temperatures (4 and -20°C) during different periods of time (1, 2 and 3 months) were evaluated in MRS-broth medium. Optical density at 580 nm was used to measure growth. Lactobacilli strains proved to be highly resistant in comparison with Biffidobacteria strains. The viable cell number of Lactobacillus casei in different sucrose concentrations, different oxidoreduction potentials and refrigeration temperature was 1x1010, 2x108 and 5x107 cfu mL-1, respectively. Growth and survival rate of Lactobacillus casei showed to be the highest.

  16. Experimental simulations of oxidizing conditions and organic decomposition on the surface of Mars

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Mancinelli, Rocco L.; Mckay, Christopher P.

    1988-01-01

    One important scientific objective of a Mars Rover Sample Return mission would be to look for traces of living and extinct life on Mars. An instrument to search for organic carbon may be the simplest instrument that could screen samples which are interesting from a biological point of view. An experimental program is described which would help to understand the nature of the oxidizing soil on Mars and the mechanism responsible for organic degradation on the Martian surface. This is approached by lab simulations of the actual conditions that occur on Mars, particularly the oxidant production by atmospheric photochemistry, and the combined effects of UV light and oxidants in decomposing organic compounds. The results will be used to formulate models of the photochemistry of the atmospheric, the atmosphere-soil interaction, and the diffusion of reactive compounds into the soils. This information will provide insights and constraints on the design of a sampling strategy to search for organic compounds on Mars.

  17. Simulations of a Liquid Hydrogen Inducer at Low-Flow Off-Design Flow Conditions

    NASA Technical Reports Server (NTRS)

    Hosangadi, A.; Ahuja, V.; Ungewitter, R. J.

    2005-01-01

    The ability to accurately model details of inlet back flow for inducers operating a t low-flow, off-design conditions is evaluated. A sub-scale version of a three-bladed liquid hydrogen inducer tested in water with detailed velocity and pressure measurements is used as a numerical test bed. Under low-flow, off-design conditions the length of the separation zone as well as the swirl velocity magnitude was under predicted with a standard k-E model. When the turbulent viscosity coefficient was reduced good comparison was obtained a t all the flow conditions examined with both the magnitude and shape of the profile matching well with the experimental data taken half a diameter upstream of the leading edge. The velocity profiles and incidence angles a t the leading edge itself were less sensitive to the back flow length predictions indicating that single-phase performance predictions may be well predicted even if the details of flow separation modeled are incorrect. However, for cavitating flow situations the prediction of the correct swirl in the back flow and the pressure depression in the core becomes critical since it leads to vapor formation. The simulations have been performed using the CRUNCH CFD(Registered Trademark) code that has a generalized multi-element unstructured framework and a n advanced multi-phase formulation for cryogenic fluids. The framework has been validated rigorously for predictions of temperature and pressure depression in cryogenic fluid cavities and has also been shown to predict the cavitation breakdown point for inducers a t design conditions.

  18. On the multiplication of xerophilic micro-organisms under simulated Martian conditions.

    PubMed

    Imshenetsky, A A; Kouzyurina, L A; Jakshina, V M

    1973-01-01

    The environmental conditions prevailing on Mars would supposedly favour the existence there of micro-organisms belonging to xerophiles, anaerobes, or micro-aerophiles, oligonitrophiles, which are able to grow in wide temperature intervals. From soil samples taken in deserts and tundra, antarctic halophilic bacteria, able to grow in liquid media containing 20-25% of sodium chloride, were isolated. Some of these cultures appeared to be also osmophilic (growth on media with 50% glucose); they grew at temperatures from 5 degrees C to 50 degrees C, and developed on media without a nitrogen source (oligonitrophiles). Of special interest was the halophilic and osmophilic form of Bacillus megaterium isolated from the Nubian desert. In experiments with this bacterium the following technique was used. A thin film of potato extract agar was prepared on a glass slide and dried over a saturated K2SO4 solution in a closed container up to the level of maximal hygroscopic moisture. The cell suspension was then sprayed on to the agar surface, the film dried again at 45 degrees C, and the glass slide put in the test tube over the saturated solution of K2SO4. The test tube was evacuated, flushed three times with a gas mixture containing 80% CO2 plus 20% Ar, and sealed. Under these conditions the water content of the agar film was equal to the maximal hygroscopic moisture; only the xerophilic form of bacteria are able to develop at this moisture level. This halophilic strain of Bac. megaterium grew satisfactorily under these conditions, as did a halophilic and osmophilic strain of Mycococcus ruber isolated in Antarctica. Both the halophilic strain of Bac. megaterium and that of M. ruber were able to grow under simulated Martian conditions. Xerophily and halophily may be linked. This assumption was supported by relatively high incidence of xerophilic forms among halophilic bacteria isolated from different soils of both high and low salt content as well as from salty muds.

  19. Space-time conditional disaggregation of precipitation at high resolution via simulation

    NASA Astrophysics Data System (ADS)

    Bárdossy, András.; Pegram, Geoffrey G. S.

    2016-02-01

    Daily rainfall data are more plentiful and reliable than pluviometer data and are the best data set to start data-repair from, worldwide. Clusters of pluviometers (a term used herein for instruments recording at subdaily intervals) record wet and dry periods in close synchrony and larger and smaller catches tend to be recorded in similar groups, but they have many gaps that require infilling. We present a method of disaggregating daily rainfall to subdaily intervals, contemporaneously infilling gaps in the pluviometers. Then the observed data, together with the infilled and disaggregated values, are interpolated over the intervening space. To achieve this disaggregation, we used a Gaussian copula-based model with time-dependent marginal distributions and censored values representing the dry periods. In addition, we generated stochastically meaningful ensembles of missing or disaggregated values, while constraining each realization to the observed daily total where relevant. This applies to the gaps filled in the pluviometers as well as the disaggregation of the daily totals. Using the disaggregated and infilled subdaily ensembles, we then conditionally spatially simulated historical rainfall in the space between the gauges and pluviometers. The mean of these stochastic realizations was compared to interpolated fields using two other procedures: Rescaled Ordinary Kriging and Rescaled Nearest Neighbors, and found our method to be superior. Where there are daily data, the daily sum constrains the simulation. In the intervening space, in a chosen daily subinterval, there will be an ensemble of values simulated from the observations. We present the results of measurements and validation of the applications to an unusually large amount of data (not just a few convenient samples), and are confident that the methodology is sound and applicable in a variety of geographies.

  20. Simulations of potential future conditions in the cache critical groundwater area, Arkansas

    USGS Publications Warehouse

    Rashid, Haveen M.; Clark, Brian R.; Mahdi, Hanan H.; Rifai, Hanadi S.; Al-Shukri, Haydar J.

    2015-01-01

    A three-dimensional finite-difference model for part of the Mississippi River Valley alluvial aquifer in the Cache Critical Groundwater Area of eastern Arkansas was constructed to simulate potential future conditions of groundwater flow. The objectives of this study were to test different pilot point distributions to find reasonable estimates of aquifer properties for the alluvial aquifer, to simulate flux from rivers, and to demonstrate how changes in pumping rates for different scenarios affect areas of long-term water-level declines over time. The model was calibrated using the parameter estimation code. Additional calibration was achieved using pilot points with regularization and singular value decomposition. Pilot point parameter values were estimated at a number of discrete locations in the study area to obtain reasonable estimates of aquifer properties. Nine pumping scenarios for the years 2011 to 2020 were tested and compared to the simulated water-level heads from 2010. Hydraulic conductivity values from pilot point calibration ranged between 42 and 173 m/d. Specific yield values ranged between 0.19 and 0.337. Recharge rates ranged between 0.00009 and 0.0006 m/d. The model was calibrated using 2,322 hydraulic head measurements for the years 2000 to 2010 from 150 observation wells located in the study area. For all scenarios, the volume of water depleted ranged between 5.7 and 23.3 percent, except in Scenario 2 (minimum pumping rates), in which the volume increased by 2.5 percent.

  1. Biodegradation of nonionic and anionic surfactants in domestic wastewater under simulated sewer conditions.

    PubMed

    Menzies, Jennifer Z; McDonough, Kathleen; McAvoy, Drew; Federle, Thomas W

    2017-02-01

    The ultimate disposition of chemicals discarded down the drain can be substantially impacted by their fate in the sewer, but to date limited data have been published on the biodegradability of chemicals in sewer systems. The recently established OECD 314 guideline (Simulation tests to assess the biodegradability of chemicals discharged in wastewater, 2008) contains a simulation method (314A) for evaluating the biodegradation of chemicals in sewage under simulated sewer conditions. This research used the OECD 314A method to evaluate the rates and pathways of primary and ultimate biodegradation of a suite of (14)C-labeled homologues representing four classes of high volume surfactants including nonionic alkyl ethoxylates (AE), and anionic alkyl ethoxysulfates (AES), alkyl sulfate (AS) and linear alkyl benzene sulfonate (LAS). All the tested homologues exhibited >97 % loss of parent, formation of metabolites, and some level (16-94 %) of CO2 production after being incubated 96-100 h in raw domestic wastewater. Comparison of C12E3, C14E3, and C16E3 showed that the first order biodegradation rate was affected by alkyl chain length with rates ranging from 6.8 h(-1) for C12E3 to 0.49 h(-1) for C16E3. Conversely, comparison of C14E1, C14E3, and C14E9 showed that the number of ethoxy units did not impact the biodegradation rate. AES and AS degraded quickly with first order kinetic rates of 1.9-3.7 and 41 h(-1) respectively. LAS did not exhibit first order decay kinetics and primary degradation was slow. Biodegradation pathways were also determined. This work shows that biodegradation in the sewer has a substantial impact on levels of surfactants and surfactant metabolites that ultimately reach wastewater treatment plants.

  2. Grid-size dependence of Cauchy boundary conditions used to simulate stream-aquifer interactions

    USGS Publications Warehouse

    Mehl, S.; Hill, M.C.

    2010-01-01

    This work examines the simulation of stream–aquifer interactions as grids are refined vertically and horizontally and suggests that traditional methods for calculating conductance can produce inappropriate values when the grid size is changed. Instead, different grid resolutions require different estimated values. Grid refinement strategies considered include global refinement of the entire model and local refinement of part of the stream. Three methods of calculating the conductance of the Cauchy boundary conditions are investigated. Single- and multi-layer models with narrow and wide streams produced stream leakages that differ by as much as 122% as the grid is refined. Similar results occur for globally and locally refined grids, but the latter required as little as one-quarter the computer execution time and memory and thus are useful for addressing some scale issues of stream–aquifer interactions. Results suggest that existing grid-size criteria for simulating stream–aquifer interactions are useful for one-layer models, but inadequate for three-dimensional models. The grid dependence of the conductance terms suggests that values for refined models using, for example, finite difference or finite-element methods, cannot be determined from previous coarse-grid models or field measurements. Our examples demonstrate the need for a method of obtaining conductances that can be translated to different grid resolutions and provide definitive test cases for investigating alternative conductance formulations.

  3. A DLM/FD/IB method for simulating compound vesicle motion under creeping flow condition

    SciTech Connect

    Pan, Tsorng-Whay Zhao, Shihai; Niu, Xiting; Glowinski, Roland

    2015-11-01

    In this article we present first a new distributed Lagrange multiplier/fictitious domain (DLM/FD) method for simulating fluid–particle interaction in Stokes flow. A conjugate gradient method driven by both pressure and distributed Lagrange multiplier, called one-shot method, has been developed to solve the discrete Stokes problem while enforcing the rigid body motion within the region occupied by the particle. The methodology is validated by comparing the numerical results of a neutrally buoyant particle of either a circular or elliptic shape with the associated Jeffery's solutions. We have successively combined the above methodology with an immersed boundary (IB) method and an elastic membrane modeled by a spring network to simulate the dynamics of a compound vesicle. In simple shear flow under creeping flow condition, the results are consistent with those obtained in literature. In Poiseuille flow, the compound vesicle motion is dominated by the motion of the vesicle membrane as expected and stays in the central region of the channel.

  4. Large-eddy simulation of propeller wake at design operating conditions

    NASA Astrophysics Data System (ADS)

    Kumar, Praveen; Mahesh, Krishnan

    2016-11-01

    Understanding the propeller wake is crucial for efficient design and optimized performance. The dynamics of the propeller wake are also central to physical phenomena such as cavitation and acoustics. Large-eddy simulation is used to study the evolution of the wake of a five-bladed marine propeller from near to far field at design operating condition. The computed mean loads and phase-averaged flow field show good agreement with experiments. The propeller wake consisting of tip and hub vortices undergoes streamtube contraction, which is followed by the onset of instabilities as evident from the oscillations of the tip vortices. Simulation results reveal a mutual induction mechanism of instability where instead of the tip vortices interacting among themselves, they interact with the smaller vortices generated by the roll-up of the blade trailing edge wake in the near wake. Phase-averaged and ensemble-averaged flow fields are analyzed to explain the flow physics. This work is supported by ONR.

  5. Carbon dioxide capture by functionalized solid amine sorbents with simulated flue gas conditions.

    PubMed

    Liu, Yamin; Ye, Qing; Shen, Mei; Shi, Jingjin; Chen, Jie; Pan, Hua; Shi, Yao

    2011-07-01

    A novel solid amine sorbent was prepared using KIT-6-type mesoporous silica modified with tetraethylenepentamine (TEPA). Its adsorption behavior toward CO(2) from simulated flue gases is investigated using an adsorption column. The adsorption capacities at temperatures of 303, 313, 333, 343, and 353 K are 2.10, 2.29, 2.58, 2.85, and 2.71 mmol g(-1), respectively. Experimental adsorption isotherms were obtained, and the average isosteric heat of adsorption was 43.8 kJ/mol. The adsorption capacity increases to 3.2 mmol g(-1) when the relative humidity (RH) of the simulated flue gas reaches 37%. The adsorption capacity is inhibited slightly by the presence of SO(2) at concentrations lower than 300 ppm but is not significantly influenced by NO at concentrations up to 400 ppm. The adsorbent is completely regenerated in 10 min at 393 K and a pressure of 5 KPa, with expected consumption energy of about 1.41 MJ kg(-1) CO(2). The adsorption capacity remains almost the same after 10 cycles of adsorption/regeneration with adsorption conditions of 10 vol % CO(2), 100 ppm SO(2), 200 ppm NO, 100% relative humidity, and a temperature of 393 K. The solid amine sorbent, KIT-6(TEPA), performs excellently for CO(2) capture and its separation from flue gas.

  6. Quantum-continuum simulation of the electrochemical response of pseudocapacitor electrodes under realistic conditions

    NASA Astrophysics Data System (ADS)

    Keilbart, Nathan; Okada, Yasuaki; Feehan, Aion; Higai, Shin'ichi; Dabo, Ismaila

    2017-03-01

    Pseudocapacitors are energy-storage devices characterized by fast and reversible redox reactions that enable them to store large amounts of electrical energy at high rates. We simulate the response of pseudocapacitive electrodes under realistic conditions to identify the microscopic factors that determine their performance, focusing on ruthenia (RuO2) as a prototypical electrode material. Electronic-structure methods are used together with a self-consistent continuum solvation (SCCS) model to build a complete data set of free energies as the surface of the charged electrode is gradually covered with protons under applied voltage. The resulting data set is exploited to compute hydrogen-adsorption isotherms and charge-voltage responses by means of grand-canonical sampling, finding close agreement with experimental voltammetry. These simulations reveal that small changes on the order of 5 μ F /cm2 in the intrinsic double-layer capacitance of the electrode-electrolyte interface can induce variations of up to 40 μ F /cm2 in the overall pseudocapacitance.

  7. A DLM/FD/IB method for simulating compound vesicle motion under creeping flow condition

    NASA Astrophysics Data System (ADS)

    Pan, Tsorng-Whay; Zhao, Shihai; Niu, Xiting; Glowinski, Roland

    2015-11-01

    In this article we present first a new distributed Lagrange multiplier/fictitious domain (DLM/FD) method for simulating fluid-particle interaction in Stokes flow. A conjugate gradient method driven by both pressure and distributed Lagrange multiplier, called one-shot method, has been developed to solve the discrete Stokes problem while enforcing the rigid body motion within the region occupied by the particle. The methodology is validated by comparing the numerical results of a neutrally buoyant particle of either a circular or elliptic shape with the associated Jeffery's solutions. We have successively combined the above methodology with an immersed boundary (IB) method and an elastic membrane modeled by a spring network to simulate the dynamics of a compound vesicle. In simple shear flow under creeping flow condition, the results are consistent with those obtained in literature. In Poiseuille flow, the compound vesicle motion is dominated by the motion of the vesicle membrane as expected and stays in the central region of the channel.

  8. Simulation of groundwater conditions and streamflow depletion to evaluate water availability in a Freeport, Maine, watershed

    USGS Publications Warehouse

    Nielsen, Martha G.; Locke, Daniel B.

    2012-01-01

    , the public-supply withdrawals (105.5 million gallons per year (Mgal/yr)) were much greater than those for any other category, being almost 7 times greater than all domestic well withdrawals (15.3 Mgal/yr). Industrial withdrawals in the study area (2.0 Mgal/yr) are mostly by a company that withdraws from an aquifer at the edge of the Merrill Brook watershed. Commercial withdrawals are very small (1.0 Mgal/yr), and no irrigation or other agricultural withdrawals were identified in this study area. A three-dimensional, steady-state groundwater-flow model was developed to evaluate stream-aquifer interactions and streamflow depletion from pumping, to help refine the conceptual model, and to predict changes in streamflow resulting from changes in pumping and recharge. Groundwater levels and flow in the Freeport aquifer study area were simulated with the three-dimensional, finite-difference groundwater-flow modeling code, MODFLOW-2005. Study area hydrology was simulated with a 3-layer model, under steady-state conditions. The groundwater model was used to evaluate changes that could occur in the water budgets of three parts of the local hydrologic system (the Harvey Brook watershed, the Merrill Brook watershed, and the buried aquifer from which pumping occurs) under several different climatic and pumping scenarios. The scenarios were (1) no pumping well withdrawals; (2) current (2009) pumping, but simulated drought conditions (20-percent reduction in recharge); (3) current (2009) recharge, but a 50-percent increase in pumping well withdrawals for public supply; and (4) drought conditions and increased pumping combined. In simulated drought situations, the overall recharge to the buried valley is about 15 percent less and the total amount of streamflow in the model area is reduced by about 19 percent. Without pumping, infiltration to the buried valley aquifer around the confining unit decreased by a small amount (0.05 million gallons per day (Mgal/d)), and discharge to the

  9. MOCCA code for star cluster simulations - V. Initial globular cluster conditions influence on blue stragglers

    NASA Astrophysics Data System (ADS)

    Hypki, Arkadiusz; Giersz, Mirek

    2017-04-01

    In this paper, we present an analysis of the properties of blue straggler (BS) populations based on MOCCA simulations covering a range of initial globular cluster conditions. We broadly separate the BSs created in our simulations into two distinct types corresponding to their formation mechanism, namely evolutionary BSs formed from binary evolution and dynamical BSs formed from collisions or mergers induced by direct dynamical interactions between stars and binaries. We find that the dominant type of BS strongly depends on the initial semi-major axis distribution. With mostly compact binaries, the number of evolutionary BSs dominates. Conversely, with mostly wide binaries, dynamical BSs dominate. Higher cluster concentrations increase the contribution from dynamical BSs without affecting the numbers of evolutionary BSs, which are thus mostly descended from primordial binaries. We further consider the ratio between the number of BSs in binaries and as single stars (RB/S). Models that prefer compact and wide binaries begin with, respectively, high and low values of the ratio RB/S before converging to a nearly universal value ∼ 0.4. Finally, the initial eccentricity distribution has little to no influence on BS formation.

  10. Comparison of Replica-Permutation Molecular Dynamics Simulations with and without Detailed Balance Condition

    NASA Astrophysics Data System (ADS)

    Nishizawa, Hiroaki; Okumura, Hisashi

    2015-07-01

    In the replica-permutation method (RPM), temperatures are not only exchanged between two replicas but also permutated among more than two replicas using the Suwa-Todo algorithm, which minimizes the rejection ratio in Monte Carlo trials. We verify the sampling efficiency of RPM that adopts Suwa-Todo algorithms with and without a detailed balance condition (DBC). To compare these techniques, molecular dynamics simulations of RPM with and without the DBC and the replica-exchange method (REM) were carried out for a chignolin molecule in explicit water. Although no difference in the numbers of folding and unfolding events was observed, the numbers of tunneling events of the two RPM simulations were larger than that of REM. This indicates that the minimization of the rejection ratio by the Suwa-Todo algorithm in RPM realizes efficient sampling. Furthermore, the sampling efficiency was slightly higher in the RPM without the DBC than in that with the DBC. The reason for this difference is also discussed.

  11. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1992-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements performed by Fahd and Steffes have shown that the opacity from gaseous SO2 under simulated Venus conditions can be well described by the Van Vleck-Weisskopf lineshape at wavelengths shortward of 2 cm, but that the opacity of wavelengths greater than 2 cm is best described by a different lineshape that was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  12. Large Eddy Simulation of an n-Dodecane Spray Flame Under Different Ambient Oxygen Conditions

    SciTech Connect

    Pei, Yuanjiang; Hu, Bing; Som, Sibendu

    2015-01-01

    An n-dodecane spray flame was simulated using a dynamic structure large eddy simulation (LES) model coupled with a detailed chemistry combustion model to understand the ignition processes and the quasi-steady state flame structure at different ambient oxygen concentrations, 13\\%, 15\\% and 21\\% at ambient temperature of 900 K and ambient density of 22.8 kg/m3, which are typical diesel-engine relevant conditions with different levels of exhaust gas recirculation (EGR). The liquid spray was treated with a traditional Lagrangian method. A 103-species skeletal mechanism was used for n-dodecane chemical kinetic model. It is observed that the main ignitions occur in rich mixture and the flames are thickened around 35 to 40 mm off the spray axis due to the enhanced turbulence induced by the strong recirculation upstream just behind the head of the flames at different oxygen concentrations. At 1 ms after start of injection, the soot production is dominated by the broader region of high temperature in rich mixture instead of the stronger oxidation of the high peak temperature. Multiple realizations were performed for the 15\\% O$_2$ condition to understand the realization to realization variation and to establish best practices for ensemble-averaging diesel spray flames. Two indexes are defined. The structure-similarity index analysis suggests at least 5 realizations are needed to obtain 99\\% similarity for mixture fraction if average of 16 realizations are used as the target at 0.8 ms. However, this scenario may be different for different scalars of interest. It is found that 2 realizations would be enough to reach 99\\% of similarity for temperature, while 8 and 14 realizations are required to achieve 99\\% similarity for soot and OH mass fraction, respectively. Similar findings are noticed at 1 ms. More realizations are needed for the magnitude-similarity index for the similar level of similarity as the structure-similarity index.

  13. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1998-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties taken under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements completed recently by Kolodner and Steffes (ICARUS 132, pp. 151-169, March 1998, attached as Appendix A) under this grant (NAGS-4190), have shown that the opacity from gaseous H2SO4 under simulated Venus conditions is best described by a different formalism than was previously used. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both spacecraft entry probe and orbiter radio occultation experiments and by radio astronomical observations, and over a range of frequencies which correspond to those used in such experiments, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  14. Robotic system for i.v. antineoplastic drug preparation: description and preliminary evaluation under simulated conditions.

    PubMed

    Cote, D D; Torchia, M G

    1989-11-01

    A robotic system for preparing doses of i.v. antineoplastic drugs is described, and measurements made with the system are compared for accuracy and reproducibility with those made by pharmacists and technicians. System hardware consists of a robotic arm, a 16-bit microcomputer, a bar-code reader, a voice synthesizer, and an electronic balance. The software includes a menu-driven main program, executable files for each robotic activity, and an interface to allow control to pass between the program and the files. The program has routines for matching the software to the hardware; for entering information about the patient, the name of the drug ordered, and the dose; for checking the dose; for selecting the number and size of the vials to be used; for specifying the manipulations of the robotic arm; for printing labels; and for maintaining records. The robot fills an order by getting and placing a vial, inserting a needle into it and withdrawing the drug, weighing the vial, agitating the container to dissolve its contents, reading a bar code, placing a syringe in a syringe manipulator, and getting an i.v. container and injecting the drug into it. Detection of any errors by a series of self-checks arrests execution of an order. No significant differences in accuracy and precision were found between the robotic system and humans performing the same tasks under simulated conditions. The robotic system required less time than humans and eliminated the possibility of direct human contact with the i.v. admixture. Under simulated conditions, a robotic system developed to assist in the preparation of i.v. antineoplastic drugs was as accurate as a manual system and was more time efficient.

  15. Laboratory Evaluation and Application of Microwave Absorption Properties under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    2002-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based or spacecraft-based radio astronomical (emission) observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or the use of laboratory measurements of such properties taken under environmental conditions that are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements have shown that the centimeter-wavelength opacity from gaseous phosphine (PH3) under simulated conditions for the outer planets far exceeds that predicted from theory over a wide range of temperatures and pressures. This fundamentally changed the resulting interpretation of Voyager radio occultation data at Saturn and Neptune. It also directly impacts planning and scientific goals for study of Saturn's atmosphere with the Cassini Radio Science Experiment and the Rossini RADAR instrument. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both spacecraft entry probe and orbiter (or flyby) radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations

  16. Development and Application of a Computer Simulation Program to Enhance the Clinical Problem-Solving Skills of Students.

    ERIC Educational Resources Information Center

    Boh, Larry E.; And Others

    1987-01-01

    A project to (1) develop and apply a microcomputer simulation program to enhance clinical medication problem solving in preclerkship and clerkship students and (2) perform an initial formative evaluation of the simulation is described. A systematic instructional design approach was used in applying the simulation to the disease state of rheumatoid…

  17. Influence of mineralogy on the preservation of amino acids under simulated Mars conditions

    NASA Astrophysics Data System (ADS)

    dos Santos, Renato; Patel, Manish; Cuadros, Javier; Martins, Zita

    2016-10-01

    The detection of organic molecules associated with life on Mars is one of the main goals of future life-searching missions such as the ESA-Roscosmos ExoMars and NASA 2020 mission. In this work we studied the preservation of 25 amino acids that were spiked onto the Mars-relevant minerals augite, enstatite, goethite, gypsum, hematite, jarosite, labradorite, montmorillonite, nontronite, olivine and saponite, and on basaltic lava under simulated Mars conditions. Simulations were performed using the Open University Mars Chamber, which mimicked the main aspects of the martian environment, such as temperature, UV radiation and atmospheric pressure. Quantification and enantiomeric separation of the amino acids were performed using gas-chromatography-mass spectrometry (GC-MS). Results show that no amino acids could be detected on the mineral samples spiked with 1 μM amino acid solution (0.1 μmol of amino acid per gram of mineral) subjected to simulation, possibly due to complete degradation of the amino acids and/or low extractability of the amino acids from the minerals. For higher amino acid concentrations, nontronite had the highest preservation rate in the experiments in which 50 μM spiking solution was used (5 μmol/g), while jarosite and gypsum had a higher preservation rate in the experiments in which 25 and 10 μM spiking solutions were used (2.5 and 1 μmol/g), respectively. Overall, the 3 smectite minerals (montmorillonite, saponite, nontronite) and the two sulfates (gypsum, jarosite) preserved the highest amino acid proportions. Our data suggest that clay minerals preserve amino acids due to their high surface areas and small pore sizes, whereas sulfates protect amino acids likely due to their opacity to UV radiation or by partial dissolution and crystallization and trapping of the amino acids. Minerals containing ferrous iron (such as augite, enstatite and basaltic lava) preserved the lowest amount of amino acids, which is explained by iron (II) catalyzed

  18. Using simulation to enhance the acquisition and retention of clinical skills in neonatology.

    PubMed

    Anderson, JoDee M; Warren, Jamie B

    2011-04-01

    Neonatal care occurs in extremely complex and dynamic environments and requires providers to operate under intense time pressure in coordination with multiple disciplines. Teaching the clinical skills requisite to effective practice requires the meticulous application of curricular design principles. Simulation can be used as an effective instructional strategy in achieving learner acquisition and retention of the cognitive, technical, and behavioral skills essential to optimal delivery of care in neonatology.

  19. Perspectives in Medical Applications of Monte Carlo Simulation Software for Clinical Practice in Radiotherapy Treatments

    NASA Astrophysics Data System (ADS)

    Boschini, Matteo; Giani, Simone; Ivanchenko, Vladimir; Rancoita, Pier-Giorgio

    2006-04-01

    We discuss the physics requirements to accurately model radiation dosimetry in the human body as performed for oncological radiotherapy treatment. Recent advancements in computing hardware and software simulation technology allow precise dose calculation in real-life imaging output, with speed suitable for clinical needs. An experimental programme, based on physics published literature, is proposed to demonstrate the actual possibility to improve the precision of radiotherapy treatment planning.

  20. Numerical simulation of adiabatons in electromagnetically induced transparency under quasi-resonance conditions

    SciTech Connect

    Parshkov, O M; Govorenko, E R

    2014-02-28

    The evolution of adiabatons in electromagnetically induced transparency in the Λ scheme of degenerate quantum transitions J = 0 → J = 1 → J = 2 with Doppler broadening of spectral lines has been numerically simulated taking into account the effect of resonance detunings. It is shown that, in the case of linearly polarised fields, an increase in the probe-field resonance detuning (under exact-resonance conditions for the control radiation) leads to a transformation of electromagnetically induced transparency into electromagnetically induced absorption at certain stages. When the control-field resonance detuning is varied, the transparency of the medium for the probe (exactly resonant) radiation monotonically decreases with increasing detuning because of the rising role of single-photon absorption. In the case of circularly polarised control radiation and linearly polarised input probe field, a probe pulse propagating in the medium splits into two pulses with oppositely directed circular polarisations. An increase in the probe pulse resonance detuning (under exact-resonance conditions for the control radiation) leads primarily to an increase in the absorption by the medium of the probe pulse, the direction of circular polarisation for which coincides with the circular-polarisation direction for the control radiation. (nonlinear optical phenomena)