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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. Copyright © 2013 Wiley Periodicals, Inc.

  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. Accuracy of linear measurement in the Galileos cone beam computed tomography under simulated clinical conditions

    PubMed Central

    Ganguly, R; Ruprecht, A; Vincent, S; Hellstein, J; Timmons, S; Qian, F

    2011-01-01

    Objectives The aim of this study was to determine the geometric accuracy of cone beam CT (CBCT)-based linear measurements of bone height obtained with the Galileos CBCT (Sirona Dental Systems Inc., Bensheim, Hessen, Germany) in the presence of soft tissues. Methods Six embalmed cadaver heads were imaged with the Galileos CBCT unit subsequent to placement of radiopaque fiduciary markers over the buccal and lingual cortical plates. Electronic linear measurements of bone height were obtained using the Sirona software. Physical measurements were obtained with digital calipers at the same location. This distance was compared on all six specimens bilaterally to determine accuracy of the image measurements. Results The findings showed no statistically significant difference between the imaging and physical measurements (P > 0.05) as determined by a paired sample t-test. The intraclass correlation was used to measure the intrarater reliability of repeated measures and there was no statistically significant difference between measurements performed at the same location (P > 0.05). Conclusions The Galileos CBCT image-based linear measurement between anatomical structures within the mandible in the presence of soft tissues is sufficiently accurate for clinical use. PMID:21697155

  7. 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.

  8. Imaging characters of the lung cancer phantoms under the simulative clinical condition performed with hard X-ray in-line holography

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Chen, Y.; Li, G.; Jiang, X.

    2013-07-01

    The simulative lung cancer tissues under the approximate clinical condition were imaged using in-line holography method with 35 keV synchrotron radiation hard X-ray. The millimeter scale simulative cancer phantoms showed adequate contrast to lung tissues in our experiment. It demonstrates that in-line holography method with synchrotron radiation hard X-ray promises to be a potential sensitive method for the early detection of lung cancer. The image contrast, standard deviation (SD) and normalized standard deviation (NSD) of different areas were calculated. It shows that the traditional method of contrast calculation does not always give a convincible result in image judgment; a standard deviation map of image taken with a proper distance of sample to detector (DSD) will correspond well to the projecting image and supply effective assistance in diagnostic judgment.

  9. 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.

  10. 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.

  11. [Clinical Simulation and Emotional Learning].

    PubMed

    Afanador, Adalberto Amaya

    2012-01-01

    At present, the clinical simulation has been incorporated into medical school curriculum. It is considered that the simulation is useful to develop skills, and as such its diffusion. Within the acquisition of skills, meaningful learning is an essential emotional component for the student and this point is essential to optimize the results of the simulation experience. Narrative description on the subject of simulation and the degree of "emotionality." The taxonomy is described for the types of clinical simulation fidelity and correlates it with the degree of emotionality required to achieve significant and lasting learning by students. It is essential to take into account the student's level of emotion in the learning process through simulation strategy. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  12. 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.

  13. Conditions Simulating Primary Bone Neoplasms.

    PubMed

    Carter, Jodi M; Howe, Benjamin Matthew; Inwards, Carrie Y

    2017-09-01

    A number of nonneoplastic conditions can mimic tumors of bone. Some of the more common mimics of primary bone tumors include infectious, inflammatory, periosteal, and degenerative joint disease-associated lesions that produce tumorlike bone surface-based or intraosseous lesions. This article considers a spectrum of reactive and nonreactive processes including stress fracture, subchondral cysts, osteonecrosis, heterotopic ossification, osteomyelitis, sarcoidosis, and amyloidoma that can present in such a way that they are mistaken for a tumor arising primary in bone. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Numerical simulation and nasal air-conditioning.

    PubMed

    Keck, Tilman; Lindemann, Jörg

    2010-01-01

    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.

  20. Conditional Simulation Using an Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Rizzo, D. M.; Besaw, L.

    2005-12-01

    Uncertainty in site characterization, due to sparsely distributed samples and incomplete site knowledge, is of major concern in resource mining and environmental engineering. Scientists are able to model the spatial continuity and quantify uncertainty of phenomena of interest (i.e. ore grade, subsurface contamination) through the generation and analysis of many equiprobable stochastic simulations (realizations) using concepts of probability theory. We have developed a method of generating equiprobable simulations by combining the traditional frame work of spatial dependencies witnessed in geostatistics with an artificial neural network (ANN) algorithm know as counterpropagation. This new method allows for the generation of simulations that respect the observed sample data as well as the data's underlying spatial structure. Conditional simulation is a natural product of the counterpropagation network using random initial weights while its architecture has computational advantages over other simulation generators due to its parallel information passing topology. Computational speedup, due to the implementation of the algorithm on a local cluster of off-the-shelf computational nodes and software, is another factor that will be discussed. The results of this research illustrate the potential applicability and utility of using the counterpropagation algorithm to conduct a probabilistic assessment while increasing interpretational value of site characterization data.

  1. 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.

  2. 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.…

  3. 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…

  4. 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…

  5. 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.

  6. 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

  7. 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.

  8. Framework conditions facilitating paediatric clinical research

    PubMed Central

    2011-01-01

    The use of unlicensed and "off-label" medicines in children is widespread. Between 50-80% of the medicines currently administered to children have neither been tested nor authorized for their use in the paediatric population which represents approximately 25% of the whole European population. On 26 January 2007, entered into force the European Regulation of Paediatric Medicines. It aims at the quality of research into medicines for children but without subjecting the paediatric population to unnecessary clinical trial. This article addresses ethical and legal issues arising from the regulation and makes recommendations for the framework conditions facilitating the development of clinical research with children. PMID:21345195

  9. 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…

  10. Clinical verification in homeopathy and allergic conditions.

    PubMed

    Van Wassenhoven, Michel

    2013-01-01

    The literature on clinical research in allergic conditions treated with homeopathy includes a meta-analysis of randomised controlled trials (RCT) for hay fever with positive conclusions and two positive RCTs in asthma. Cohort surveys using validated Quality of Life questionnaires have shown improvement in asthma in children, general allergic conditions and skin diseases. Economic surveys have shown positive results in eczema, allergy, seasonal allergic rhinitis, asthma, food allergy and chronic allergic rhinitis. This paper reports clinical verification of homeopathic symptoms in all patients and especially in various allergic conditions in my own primary care practice. For preventive treatments in hay fever patients, Arsenicum album was the most effective homeopathic medicine followed by Nux vomica, Pulsatilla pratensis, Gelsemium, Sarsaparilla, Silicea and Natrum muriaticum. For asthma patients, Arsenicum iodatum appeared most effective, followed by Lachesis, Calcarea arsenicosa, Carbo vegetabilis and Silicea. For eczema and urticaria, Mezereum was most effective, followed by Lycopodium, Sepia, Arsenicum iodatum, Calcarea carbonica and Psorinum. The choice of homeopathic medicine depends on the presence of other associated symptoms and 'constitutional' features. Repertories should be updated by including results of such clinical verifications of homeopathic prescribing symptoms. Copyright © 2012 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  11. Simulations of Fluid Nitromethane Under Extreme Conditions

    SciTech Connect

    Fried, L E; Reed, E J; Manaa, M R

    2003-07-15

    We report density functional molecular dynamics simulations to determine the early chemical events of hot (T = 3000 K) and dense (1.97 g/cm{sup 3}, V/V{sub 0} = 0.68) nitromethane (CH{sub 3}NO{sub 2}). The first step in the decomposition process is an intermolecular proton abstraction mechanism that leads to the formation of CH{sub 3}NO{sub 2}H and the aci ion H{sub 2}CNO{sub 2}{sup -}, in support of evidence from static high-pressure and shock experiments. An intramolecular hydrogen transfer that transforms nitromethane into the aci acid form, CH{sub 2}NO{sub 2}H, accompanies this event. This is the first confirmation of chemical reactivity with bond selectivity for an energetic material near the condition of fully reacted specimen. We also report the decomposition mechanism followed up to the formation of H{sub 2}O as the first stable product.

  12. 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.

  13. Simulating Clinical Carious Lesions in Composition Teeth.

    ERIC Educational Resources Information Center

    Ambrose, E. R.; And Others

    1981-01-01

    A step-by-step technique to alter stock composition teeth and create simulated carious conditions that are ideal or otherwise is presented. The procedures provide the student with life-like lesions, suitable in texture and location and similar to conditions found in the oral cavity. (MLW)

  14. 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.

  15. Organic degradation under simulated Martian conditions

    NASA Astrophysics Data System (ADS)

    Stoker, Carol R.; Bullock, Mark A.

    1997-05-01

    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 Å was measured to be 1.46+/-1.0×10-6molecules/photon. Scaled to Mars, this represents an organic destruction rate of 2.24+/-1.2×10-4g of Cm-2yr-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.

  16. Exposing Conditional Inclusive Ideologies through Simulated Interactions

    ERIC Educational Resources Information Center

    Dotger, Benjamin; Ashby, Christine

    2010-01-01

    This manuscript examines how teacher candidates enacted their extensive inclusive classroom preparation within simulated interactions. Diffusing a common medical education pedagogy to teacher education, the researchers situated inclusively-trained teacher candidates in front of standardized paraprofessionals. Data from these simulated interactions…

  17. [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.

  18. 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.

  19. Clinical simulation: a better way of learning?

    PubMed

    Haidar, Elizabeth

    2009-09-01

    This article describes the practice of clinical simulation, in which real-world experiences are replicated in learning environments. It also describes how education programmes can be adapted to accommodate this practice so that students can participate actively in their education.

  20. Periodontal conditions in vegetarians: a clinical study.

    PubMed

    Staufenbiel, I; Weinspach, K; Förster, G; Geurtsen, W; Günay, H

    2013-08-01

    Investigations about possible correlations between vegetarian diet and periodontal conditions are rare and characterized by small case numbers. The aim of this clinical study was to investigate the influence of a vegetarian diet on periodontal parameters with an appropriate sample size. A total of 200 patients, 100 vegetarians and 100 non-vegetarians, were included in the study. All patients were examined including a full mouth assessment of the periodontal and dental conditions. In addition, a questionnaire was handed out to ask for patients' oral hygiene habits and level of education. For statistical analysis the Mann-Whitney Test (χ(2) for analysis of the questionnaire) was applied (level of significance: P<0.05). Well known periodontal risk factors like age, gender and smoking habits were equally distributed within each group (71 females, 29 males, respectively and 10 smokers in each group; mean age: 41.45 years vegetarians versus 41.72 years non-vegetarians). Vegetarians had significantly lower probing pocket depths (P=0.039), bleeding on probing (P=0.001), periodontal screening index (P=0.012), a better hygiene index (P<0.001) and less mobile teeth (P=0.013). Dental examinations revealed significantly less missing teeth (P=0.018) but also more decayed (P=0.001) and eroded (P=0.026) teeth in vegetarians. Furthermore, vegetarians had a higher level of education (P<0.001), but visited dentists significantly less frequent. Vegetarians revealed better periodontal conditions (less inflammation signs, less periodontal damage and a better dental home care). However, it should be considered that vegetarians are not only avoiding meat in their nutrition but are also characterized by an overall healthier life style.

  1. A Systems Approach to Designing Effective Clinical Trials Using Simulations

    PubMed Central

    Fusaro, Vincent A.; Patil, Prasad; Chi, Chih-Lin; Contant, Charles F.; Tonellato, Peter J.

    2013-01-01

    Background Pharmacogenetics in warfarin clinical trials have failed to show a significant benefit compared to standard clinical therapy. This study demonstrates a computational framework to systematically evaluate pre-clinical trial design of target population, pharmacogenetic algorithms, and dosing protocols to optimize primary outcomes. Methods and Results We programmatically created an end-to-end framework that systematically evaluates warfarin clinical trial designs. The framework includes options to create a patient population, multiple dosing strategies including genetic-based and non-genetic clinical-based, multiple dose adjustment protocols, pharmacokinetic/pharmacodynamics (PK/PD) modeling and international normalization ratio (INR) prediction, as well as various types of outcome measures. We validated the framework by conducting 1,000 simulations of the CoumaGen clinical trial primary endpoints. The simulation predicted a mean time in therapeutic range (TTR) of 70.6% and 72.2% (P = 0.47) in the standard and pharmacogenetic arms, respectively. Then, we evaluated another dosing protocol under the same original conditions and found a significant difference in TTR between the pharmacogenetic and standard arm (78.8% vs. 73.8%; P = 0.0065), respectively. Conclusions We demonstrate that this simulation framework is useful in the pre-clinical assessment phase to study and evaluate design options and provide evidence to optimize the clinical trial for patient efficacy and reduced risk. PMID:23261867

  2. 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.

  3. [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.

  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. 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'…

  6. [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.

  7. Thermoacoustic environments to simulate reentry conditions

    NASA Technical Reports Server (NTRS)

    Bayerdoerfer, Gerhard

    1994-01-01

    Aerothermal environments as encountered during the reentry of spaceplanes or during the cruise of hypersonic aircrafts represent complex loading conditions for the external structures of those vehicles. In order to shield against the aerodynamic heating a special Thermal Protection System (TPS) is required which is designed as a light weight structure to reduce the weight penalty. TPS is therefore vulnerable to vibroacoustic fatigue caused by the pressure fluctuations of the environment. Because of the complex interactions between the loading forces and the resulting structural response which make an analytical treatment difficult and in order to provide means for fatigue testing IABG has designed and built a thermoacoustic facility which recently became operational. The facility is capable to produce surface temperatures up to 1.300 C at sound pressure levels up to 160 dB. This paper describes the design of the facility, some operational test work it also deals with problems associated with the facility instrumentation.

  8. 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.

  9. Simulating Freshwater Availability under Future Climate Conditions

    NASA Astrophysics Data System (ADS)

    Zhao, F.; Zeng, N.; Motesharrei, S.; Gustafson, K. C.; Rivas, J.; Miralles-Wilhelm, F.; Kalnay, E.

    2013-12-01

    Freshwater availability is a key factor for regional development. Precipitation, evaporation, river inflow and outflow are the major terms in the estimate of regional water supply. In this study, we aim to obtain a realistic estimate for these variables from 1901 to 2100. First we calculated the ensemble mean precipitation using the 2011-2100 RCP4.5 output (re-sampled to half-degree spatial resolution) from 16 General Circulation Models (GCMs) participating the Coupled Model Intercomparison Project Phase 5 (CMIP5). The projections are then combined with the half-degree 1901-2010 Climate Research Unit (CRU) TS3.2 dataset after bias correction. We then used the combined data to drive our UMD Earth System Model (ESM), in order to generate evaporation and runoff. We also developed a River-Routing Scheme based on the idea of Taikan Oki, as part of the ESM. It is capable of calculating river inflow and outflow for any region, driven by the gridded runoff output. River direction and slope information from Global Dominant River Tracing (DRT) dataset are included in our scheme. The effects of reservoirs/dams are parameterized based on a few simple factors such as soil moisture, population density and geographic regions. Simulated river flow is validated with river gauge measurements for the world's major rivers. We have applied our river flow calculation to two data-rich watersheds in the United States: Phoenix AMA watershed and the Potomac River Basin. The results are used in our SImple WAter model (SIWA) to explore water management options.

  10. 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...

  11. 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...

  12. [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.

  13. 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.

  14. 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).

  15. Spatial interpolation of forest conditions using co-conditional geostatistical simulation

    Treesearch

    H. Todd Mowrer

    2000-01-01

    In recent work the author used the geostatistical Monte Carlo technique of sequential Gaussian simulation (s.G.s.) to investigate uncertainty in a GIS analysis of potential old-growth forest areas. The current study compares this earlier technique to that of co-conditional simulation, wherein the spatial cross-correlations between variables are included. As in the...

  16. Clinical Simulation: A Protocol for Evaluation of Mobile Technology.

    PubMed

    Mather, Carey; Jensen, Sanne; Cummings, Elizabeth

    2017-01-01

    For mobile technology to be accepted at point of care in healthcare environments there is a need to demonstrate benefits whilst ameliorating the risks and challenges. To provide a standardised approach to evaluation of mobile technology a simulation protocol was developed to provide guidance for its use in healthcare environments. Simulated conditions provide the opportunity to assess intended and unintended consequences and identify potential workarounds when using technology. The protocol can also be used to demonstrate the importance of the development of digital professionalism by end-users prior to students entering the clinical practice setting. The mobile technology protocol was adapted from a health information systems protocol developed and used at the ITX Lab, Denmark for use in other simulation laboratories. Use case scenarios were developed to enable evaluation of mobile technology for mobile learning of nurses, nurse supervisors, students and patients. The scenarios can be used in a range of simulated environments including hospital bedside, outpatient clinic or community settings. A case study exemplar of a nurse and patient is included to demonstrate how the mobile technology protocol can be applied.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Do Downscaled General Circulation Models Reliably Simulate Current Climatic Conditions?

    NASA Astrophysics Data System (ADS)

    Hay, L.; Bock, A. R.; McCabe, G. J., Jr.; Markstrom, S. L.; Atkinson, D.

    2016-12-01

    The accuracy of statistically-downscaled (SD) General Circulation Model (GCM) simulations of monthly surface climate for historical conditions (1950-2000) used to drive a monthly water balance model (MWBM) were assessed for the conterminous United States (CONUS). SD monthly precipitation (PPT) and atmospheric temperature (TAVE) from 95 GCMs (38 from the coupled model intercomparison project (CMIP) 3 and 57 from CMIP5) were used as inputs to a MWBM. Input (PPT, TAVE) and output (snow water equivalent (SWE), and runoff (RUN)) MWBM variables were evaluated by comparing variables computed using historical climate forcings (developed from gridded station data (GSD)) with those computed using historical SD climate. Distributions of GSD- and SD-based MWBM variables were compared using the two-sample Kolmogorov-Smirnov test (KS Test). When all MWBM variables were considered, the KS Test results showed an overall improvement by the CMIP5- relative to CMIP3-based simulations, likely due to improvements in PPT simulations. Results from this study indicate that for the majority of the CONUS, there are downscaled GCMs that can reliably simulate current climatic conditions. But, in some locations (particularly in California), there are no downscaled GCMs tested that replicate historical conditions for all four MWBM variables. In these locations, improved GCM simulations of precipitation are needed to more reliably estimate components of the hydrologic cycle.

  6. 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.

  7. 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.

  8. Persistence of initial conditions in continental scale air quality simulations

    EPA Science Inventory

    This study investigates the effect of initial conditions (IC) for pollutant concentrations in the atmosphere and soil on simulated air quality for two continental-scale Community Multiscale Air Quality (CMAQ) model applications. One of these applications was performed for springt...

  9. The simulation of microgravity conditions on the ground.

    PubMed

    Albrecht-Buehler, G

    1992-10-01

    This chapter defines weightlessness as the condition where the acceleration of an object is independent of its mass. Applying this definition to the clinostat, it argues that the clinostat is very limited as a simulator of microgravity because it (a) generates centrifugal forces, (b) generates particle oscillations with mass-dependent amplitudes of speed and phase shifts relative to the clinorotation, (c) is unable to remove globally the scalar effects of gravity such as hydrostatic pressure, which are independent of the direction of gravity in the first place, and, (d) generates more convective mixing of the gaseous or liquid environment of the test object, rather than eliminating it, as would true weightlessness. It is proposed that attempts to simulate microgravity must accept the simulation of one aspect of microgravity at a time, and urges that the suppression of convective currents be a major feature of experimental methods that simulate microgravity.

  10. 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.

  11. Cultural Norms of Clinical Simulation in Undergraduate Nursing Education

    PubMed Central

    2015-01-01

    Simulated practice of clinical skills has occurred in skills laboratories for generations, and there is strong evidence to support high-fidelity clinical simulation as an effective tool for learning performance-based skills. What are less known are the processes within clinical simulation environments that facilitate the learning of socially bound and integrated components of nursing practice. Our purpose in this study was to ethnographically describe the situated learning within a simulation laboratory for baccalaureate nursing students within the western United States. We gathered and analyzed data from observations of simulation sessions as well as interviews with students and faculty to produce a rich contextualization of the relationships, beliefs, practices, environmental factors, and theoretical underpinnings encoded in cultural norms of the students’ situated practice within simulation. Our findings add to the evidence linking learning in simulation to the development of broad practice-based skills and clinical reasoning for undergraduate nursing students. PMID:28462300

  12. 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.

  13. Conditional flood frequency and catchment state: a simulation approach

    NASA Astrophysics Data System (ADS)

    Brettschneider, Marco; Bourgin, François; Merz, Bruno; Andreassian, Vazken; Blaquiere, Simon

    2017-04-01

    Catchments have memory and the conditional flood frequency distribution for a time period ahead can be seen as non-stationary: it varies with the catchment state and climatic factors. From a risk management perspective, understanding the link of conditional flood frequency to catchment state is a key to anticipate potential periods of higher flood risk. Here, we adopt a simulation approach to explore the link between flood frequency obtained by continuous rainfall-runoff simulation and the initial state of the catchment. The simulation chain is based on i) a three state rainfall generator applied at the catchment scale, whose parameters are estimated for each month, and ii) the GR4J lumped rainfall-runoff model, whose parameters are calibrated with all available data. For each month, a large number of stochastic realizations of the continuous rainfall generator for the next 12 months are used as inputs for the GR4J model in order to obtain a large number of stochastic realizations for the next 12 months. This process is then repeated for 50 different initial states of the soil moisture reservoir of the GR4J model and for all the catchments. Thus, 50 different conditional flood frequency curves are obtained for the 50 different initial catchment states. We will present an analysis of the link between the catchment states, the period of the year and the strength of the conditioning of the flood frequency compared to the unconditional flood frequency. A large sample of diverse catchments in France will be used.

  14. 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

  15. 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

    Ganguly, Rumpa; Ramesh, Aruna; Pagni, Sarah

    2016-06-01

    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. 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. 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. 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.

  16. 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.

  17. 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.

  18. Using simulations to teach clinical nursing.

    PubMed

    Hanna, D R

    1991-01-01

    Incorporating play into formal teaching strategies was introduced in theory over 75 years ago by John Dewey and the Gestalt theorists. Play, in the form of simulations, has had a significant role in contemporary nursing education. Simulations can teach more than a skill or an idea, since they can be designed to teach the complexification of ideas. The author explores the theoretical and historical development, the advantages and disadvantages, and future uses of simulations.

  19. Enhancing Higher Order Thinking Skills through Clinical Simulation

    ERIC Educational Resources Information Center

    Varutharaju, Elengovan; Ratnavadivel, Nagendralingan

    2014-01-01

    Purpose: The study aimed to explore, describe and analyse the design and implementation of clinical simulation as a pedagogical tool in bridging the deficiency of higher order thinking skills among para-medical students, and to make recommendations on incorporating clinical simulation as a pedagogical tool to enhance thinking skills and align the…

  20. Comparison of different ore reserve estimation methods using conditional simulation

    SciTech Connect

    Baafi, E.Y.; Kim, Y.C.

    1983-12-01

    The authors discuss the results of a series of comparative studies where polygonal, IDS, and kriging were compared for their local estimation accuracy. The study was performed on simulated coal deposits and the evaluation parameter chosen was the coal thickness. For this study many conditionally simulated deposits having different degrees of seam thickness continuity were first developed. Each simulated deposit covered an area of 9km x 9km that was subdivided into 100 mine-planning blocks of 900m x 900m. Thickness estimation was made for these mine-planning blocks using surrounding DDH assays. In all cases tested, from a perfect continuity to a complete lack of continuity in coal-seam thickness kriging gave the best estimates, followed by IDS and polygonal methods.

  1. New technique for simulation of microgravity and variable gravity conditions

    NASA Astrophysics Data System (ADS)

    de la Rosa, R.; Alonso, A.; Abasolo, D. E.; Hornero, R.; Abasolo, D. E.

    2005-08-01

    This paper suggests a microgravity or variable gravity conditions simulator based on a Neuromuscular Control System (NCS), working as a man-machine interface. The subject under training lies on an active platform that counteracts his weight. And a Virtual Reality (VR) system displays a simulated environment, where the subject can interact a number of settings: extravehicular activity (EVA), walking on the Moon or training the limb response faced with variable acceleration scenes. Results related to real-time voluntary control have been achieved with neuromuscular interfaces at the Bioengineering Group in the University of Valladolid. It has been employed a custom real-time system to train arm movements. This paper outlines a more complex design that can complement other training facilities, like the buoyancy pool, in the task of microgravity simulation.

  2. 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.

  3. 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.

  4. 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.

  5. Boundary conditions for OH, L, and H-mode simulations

    SciTech Connect

    Singer, C.E.; Bateman, G.; Stotler, D.P.

    1988-06-01

    A method for prescribing appropriate boundary conditions for predictive simulations using flux-surface-averaged plasma transport codes is described. The model makes use of the present theoretical understanding of L and H-mode transport mechanisms and is consistent with trends in existing data. It is calibrated against an ASDEX experiment and used to predict the edge behavior in CIT. 14 refs., 7 figs.

  6. 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.

  7. 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.

  8. Accurate initial conditions in mixed dark matter-baryon simulations

    NASA Astrophysics Data System (ADS)

    Valkenburg, Wessel; Villaescusa-Navarro, Francisco

    2017-06-01

    We quantify the error in the results of mixed baryon-dark-matter hydrodynamic simulations, stemming from outdated approximations for the generation of initial conditions. The error at redshift 0 in contemporary large simulations is of the order of few to 10 per cent in the power spectra of baryons and dark matter, and their combined total-matter power spectrum. After describing how to properly assign initial displacements and peculiar velocities to multiple species, we review several approximations: (1) using the total-matter power spectrum to compute displacements and peculiar velocities of both fluids, (2) scaling the linear redshift-zero power spectrum back to the initial power spectrum using the Newtonian growth factor ignoring homogeneous radiation, (3) using a mix of general-relativistic gauges so as to approximate Newtonian gravity, namely longitudinal-gauge velocities with synchronous-gauge densities and (4) ignoring the phase-difference in the Fourier modes for the offset baryon grid, relative to the dark-matter grid. Three of these approximations do not take into account that dark matter and baryons experience a scale-dependent growth after photon decoupling, which results in directions of velocity that are not the same as their direction of displacement. We compare the outcome of hydrodynamic simulations with these four approximations to our reference simulation, all setup with the same random seed and simulated using gadget-III.

  9. 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.

  10. Using Simulated Patients to Teach Clinical Nutrition.

    ERIC Educational Resources Information Center

    Carroll, J. Gregory; And Others

    1983-01-01

    "Clinical Nutrition in an Interdisciplinary Setting" is a course designed to introduce basic nutrition knowledge and concepts of nutritional assessment, counseling, and intervention in the clinical care of patients. Provides a brief course overview and descriptions of its development, use, and preliminary evaluation of the patient simulation…

  11. 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.

  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. Role modeling clinical judgment for an unfolding older adult simulation.

    PubMed

    Lasater, Kathie; Johnson, Elizabeth A; Ravert, Patricia; Rink, Doris

    2014-05-01

    Nurse educators must foster development of clinical judgment in students to help them provide the best care for the increasing population of older adult patients. This article reports qualitative findings from a mixed-methods study that focused on clinical judgment in the simulated perioperative care of an older adult. The sample was composed of treatment and control groups of prelicensure students (N = 275) at five sites. The treatment group watched a video of an expert nurse role model caring for a patient similar to the simulation patient, whereas the control group did not watch the video. Four weeks after simulation, participants cared for real-life, older adult perioperative patients. After the simulated and real-life care experiences, participants completed questionnaires related to clinical judgment dimensions. These two data sets revealed rich findings about the students' simulation learning, affirming the value of expert role models. Transferability of simulation learning to practice was also explored. Copyright 2014, SLACK Incorporated.

  15. 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.

  16. 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.

  17. 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,…

  18. 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,…

  19. Fabric Force Sensors for the Clinical Breast Examination Simulator.

    PubMed

    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.

  20. 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

  1. 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

  2. Estimation of stereovision in conditions of blurring simulation

    NASA Astrophysics Data System (ADS)

    Krumina, Gunta; Ozolinsh, Maris; Lacis, Ivazs; Lyakhovetskii, Vsevolod

    2005-08-01

    The aim of this study was to evaluate the simulation of eye pathologies, such as amblyopia and cataracts, to estimate the stereovision in artificial conditions, and to compare the results on the stereothreshold obtained in artificial and real- pathologic conditions. Characteristic of the above-mentioned real-life forms of a reduced vision is a blurred image in one of the eyes. The blurring was simulated by (i) defocusing, (ii) blurred stimuli on the screen, and (iii) occluding of an eye with PLZT or PDLC plates. When comparing the methods, two parameters were used: the subject's visual acuity and the modulation depth of the image. The eye occluder method appeared to systematically provide higher stereothreshold values than the rest of the methods. The PLZT and PDLC plates scattered more in the blue and decreased the contrast of the stimuli when the blurring degree was increased. In the eye occluder method, the stereothreshold increased faster than in the defocusation and monitor stimuli methods when the visual acuity difference was higher than 0.4. It has been shown that the PLZT and PDLC plates are good optical phantoms for the simulation of a cataract, while the defocusation and monitor stimuli methods are more suitable for amblyopia.

  3. Remote cardiac ischemic conditioning: underlying mechanisms and clinical applications.

    PubMed

    Gaspar, António; Leite-Moreira, Adelino F

    2012-01-01

    Despite a significant improvement in the care of acute coronary disease, mortality and morbidity remain important. One explanation for this lies in the fact that the very coronary reperfusion may paradoxically result in additional myocardial injury, through the so-called ischemia-reperfusion injury, partially mitigating the beneficial effects of myocardial reperfusion. Over the past two decades, numerous pharmacological interventions (such as the use of antioxidants, anti-inflammatory, magnesium, glucose/insulin/potassium, rapid normalization of pH) were studied in order to prevent ischemia-reperfusion injury. Despite the promising results obtained in animal experiments, attempts to transpose these results to humans, and consequently to clinical practice, have been disappointing. On the other hand, cardiac ischemic conditioning is an intervention that has produced positive results. Ischemic conditioning refers to the protection induced by short periods of ischemia followed by reperfusion, prior to a major ischemic event. Ischemic stimulus can be applied before (pre-conditioning), during (per-conditioning) or after (post-conditioning) the major ischemic event. An important finding regarding cardiac ischemic conditioning, was that protection could be induced remotely, introducing the concept of remote ischemic conditioning. In this paper, we proposed to review the mechanisms underlying remote ischemic cardiac conditioning and the possible clinical applications, considering more specifically pre and per-conditioning.

  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. Quality of care at retail clinics for 3 common conditions.

    PubMed

    Shrank, William H; Krumme, Alexis A; Tong, Angela Y; Spettell, Claire M; Matlin, Olga S; Sussman, Andrew; Brennan, Troyen A; Choudhry, Niteesh K

    2014-10-01

    Evaluation of quality of care across retail clinics in a geographically diverse population has not been undertaken to date. We sought to evaluate and compare the quality of care for otitis media, pharyngitis, and urinary tract infection received in retail medical clinics in CVS pharmacies ("MinuteClinics" [MCs]), ambulatory care facilities (ACFs), and emergency departments (EDs). We used 14 measures constructed from RAND Corporation's Quality Assurance Tools and guidelines from the American Academy of Pediatrics, the American Academy of Family Physicians, and the Infectious Diseases Society of America. Our cohort was drawn from Aetna medical and prescription claims, 2009-2012. Members were matched on visit date, condition, and propensity score. Generalized estimating equations were used to compare quality across clinic type, overall, and by index condition. We matched 75,886 episodes of care, of which 20,153 were eligible for at least 1 quality measure. MCs performed better than EDs and ACFs in 7 measures. In a multivariable model, MCs performed better than ACFs and EDs across all quality measures ([OR 0.42; 95% CI, 0.40-0.45; P < .0001; ACF vs MC] [OR 0.29; 95% CI, 0.27-0.31; P < .0001; ED vs MC]). Results for each condition were significant at P < .0001. Quality of care for these conditions based on widely accepted objective measures was superior in MinuteClinics compared with ACFs and EDs.

  6. 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

  7. Survival rates of some terrestrial microorganisms under simulated space conditions

    NASA Astrophysics Data System (ADS)

    Koike, J.; Oshima, T.; Koike, K. A.; Taguchi, H.; Tanaka, R.; Nishimura, K.; Miyaji, M.

    1992-10-01

    In connection with planetary quarantine, we have been studying the survival rates of nine species of terrestrial microorganisms (viruses, bacteria, yeasts, fungi, etc.) under simulated interstellar conditions. If common terrestrial microorganisms cannot survive in space even for short periods, we can greatly reduce expenditure for sterilizing space probes. The interstellar environment in the solar system has been simulated by low temperature, high vacuum (77 k, 4 × 10-6 torr), and protons irradiation from a Van de Graaff generator. After exposure to a barrage of protons corresponding to about 250 years of irradiation in solar space, Tobacco mosaic virus. Bacillus subtilis spores, Aspergillus niger spores, and Clostridium mangenoti spores showed survival rates of 82%, 45%, 28%, and 25%, respectively. Furthermore, pathogenic Candida albicans showed 7% survival after irradiation corresponding to about 60 years in space.

  8. Passive films on metallic biomaterials under simulated physiological conditions.

    PubMed

    Pound, B G

    2014-05-01

    The metallic materials used for implantable medical devices are predominantly stainless steels, Ti and its alloys, and Co-Cr alloys. The corrosion resistance of each of these materials is associated with a passive oxide film on its surface. Since corrosion resistance is crucial to implant performance, considerable effort has been focused on understanding the nature of the passive film present under physiological conditions. Surface analytical techniques and electrochemical impedance spectroscopy have been used in a number of studies to investigate the passive film formed on metallic biomaterials in simulated physiological solutions. This review focuses on the surface characteristics of these materials with regard to composition, thickness, and impedance of the passive films. Of particular interest are changes in the films with surface treatment and the nature of the films developed over time in the simulated solutions. Copyright © 2013 Wiley Periodicals, Inc.

  9. 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.

  10. 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

  11. 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.

  12. Observational Simulation of Icing in Extreme Weather Conditions

    NASA Astrophysics Data System (ADS)

    Gultepe, Ismail; Heymsfield, Andrew; Agelin-Chaab, Martin; Komar, John; Elfstrom, Garry; Baumgardner, Darrel

    2017-04-01

    Observations and prediction of icing in extreme weather conditions are important for aviation, transportation, and shipping applications, and icing adversely affects the economy. Icing environments can be studied either in the outdoor atmosphere or in the laboratory. There have been several aircraft based in-situ studies related to weather conditions affecting aviation operations, transportation, and marine shipping that includes icing, wind, and turbulence. However, studying severe weather conditions from aircraft observations are limited due to safety and sampling issues, instrumental uncertainties, and even the possibility of aircraft producing its own physical and dynamical effects. Remote sensing based techniques (e.g. retrieval techniques) for studying severe weather conditions represent usually a volume that cannot characterize the important scales and also represents indirect observations. Therefore, laboratory simulations of atmospheric processes can help us better understand the interactions among microphysical and dynamical processes. The Climatic Wind Tunnel (CWT) in ACE at the University of Ontario Institute of Technology (UOIT) has a large semi-open jet test chamber with flow area 7-13 m2 that can precisely control temperatures down to -40°C, and up to 250 km hr-1 wind speeds, for heavy or dry snow conditions with low visibility, similar to ones observed in the Arctic and cold climate regions, or at high altitude aeronautical conditions. In this study, the ACE CWT employed a spray nozzle array suspended in its settling chamber and fed by pressurized water, creating various particle sizes from a few microns up to mm size range. This array, together with cold temperature and high wind speed, enabled simulation of severe weather conditions, including icing, visibility, strong wind and turbulence, ice fog and frost, freezing fog, heavy snow and blizzard conditions. In this study, the test results will be summarized, and their application to aircraft

  13. 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.

  14. 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.

  15. The application of clinical simulation in crisis management training.

    PubMed

    Wong, S H S; Ng, K F J; Chen, P P

    2002-04-01

    Since it was first introduced more than 30 years ago, clinical simulation has become a popular tool for medical training, particularly in crisis management. The modern high-fidelity patient simulator consists of a whole-body mannequin with integrated electronic patient monitoring; it is controlled by computers capable of simulating numerous clinical scenarios and patient characteristics, and reacting to various interventions appropriately. Simulator training is theoretically superior to conventional training in management of rare crisis situations, as it allows unlimited practice in a safe yet familiar environment. Training in clinical skills can be developed, together with competency in crisis management behaviours such as leadership and communication skills. Although there is evidence demonstrating the popularity, reliability, and validity of simulator training, its superiority over conventional training has not been proven, and research in this area is required.

  16. 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.

  17. Clinical simulation training improves the clinical performance of Chinese medical students

    PubMed Central

    Zhang, Ming-ya; Cheng, Xin; Xu, An-ding; Luo, Liang-ping; Yang, Xuesong

    2015-01-01

    Background Modern medical education promotes medical students’ clinical operating capacity rather than the mastery of theoretical knowledge. To accomplish this objective, clinical skill training using various simulations was introduced into medical education to cultivate creativity and develop the practical ability of students. However, quantitative analysis of the efficiency of clinical skill training with simulations is lacking. Methods In the present study, we compared the mean scores of medical students (Jinan University) who graduated in 2013 and 2014 on 16 stations between traditional training (control) and simulative training groups. In addition, in a clinical skill competition, the objective structured clinical examination (OSCE) scores of participating medical students trained using traditional and simulative training were compared. The data were statistically analyzed and qualitatively described. Results The results revealed that simulative training could significantly enhance the graduate score of medical students compared with the control. The OSCE scores of participating medical students in the clinical skill competition, trained using simulations, were dramatically higher than those of students trained through traditional methods, and we also observed that the OSCE marks were significantly increased for the same participant after simulative training for the clinical skill competition. Conclusions Taken together, these data indicate that clinical skill training with a variety of simulations could substantially promote the clinical performance of medical students and optimize the resources used for medical education, although a precise analysis of each specialization is needed in the future. PMID:26478142

  18. Clinical conditions responsible for hyperviscosity and skin ulcers complications.

    PubMed

    Caimi, Gregorio; Canino, Baldassare; Lo Presti, Rosalia; Urso, Caterina; Hopps, Eugenia

    2017-05-19

    In this brief review, we have examined some clinical conditions that result to be associated to an altered hemorheological profile and at times accompanied by skin ulcers. This skin condition may be observed in patients with the following condtions, such as primary polycythemic hyperviscosity (polycythemia, thrombocytemia) treated with hydroxyurea, primary plasma hyperviscosity (multiple myeloma, cryoglobulinemia, cryofibrinogenemia, dysfibrinogenemia, and connective tissue diseases), primary sclerocythemic hyperviscosity (hereditary spherocytosis, thalassemia, and sickle cell disease). In addition, it may be present in patients with secondary hyperviscosity conditions such as diabetes mellitus, arterial hypertension, critical limb ischemia and chronic venous insufficiency.

  19. 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.

  20. 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 §...

  1. 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.

  2. 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.

  3. 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.

  4. Pyrite oxidation under simulated acid rain weathering conditions.

    PubMed

    Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

    2017-07-31

    We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

  5. 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…

  6. 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…

  7. 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)

  8. 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…

  9. Constructing maternal-child learning experiences using clinical simulations.

    PubMed

    Jeffries, Pamela R; Bambini, Deborah; Hensel, Desiree; Moorman, Megan; Washburn, Joy

    2009-01-01

    Clinical simulations are gaining more attention in the field of maternal-child health and allow nursing programs and service organizations to assess competency of students and staff in key patient safety situations. Nursing and midwifery programs, orientations, and yearly reaccreditation modules commonly include simulation on postpartum hemorrhage, placenta abruption, shoulder distocia, and other high-risk, low-incidence emergency events. This article describes the use of simulations by educators and managers as teaching or professional development strategies.

  10. Modelling and simulation of concrete leaching under outdoor exposure conditions.

    PubMed

    Schiopu, Nicoleta; Tiruta-Barna, Ligia; Jayr, Emmanuel; Méhu, Jacques; Moszkowicz, Pierre

    2009-02-15

    Recently, a demand regarding the assessment of release of dangerous substances from construction products was raised by European Commission which has issued the Mandate M/366 addressed to CEN. This action is in relation with the Essential Requirement No. 3 "Hygiene, Health and Environment" of the Construction Products Directive (89/106/EC). The potential hazard for environment and health may arise in different life cycle stages of a construction product. During the service life stage, the release of substances due to contact with the rain water is the main potential hazard source, as a consequence of the leaching phenomenon. The objective of this paper is to present the development of a coupled chemical-transport model for the case of a concrete based construction product, i.e. concrete paving slabs, exposed to rain water under outdoor exposure conditions. The development of the model is based on an iterative process of comparing the experimental results with the simulated results up to an acceptable fit. The experiments were conducted at laboratory scale (equilibrium and dynamic leaching tests) and field scale. The product was exposed for one year in two types of leaching scenarios under outdoor conditions, "runoff" and "stagnation", and the element release was monitored. The model was calibrated using the experimental data obtained at laboratory scale and validated against measured field data, by taking into account the specific rain water balance and the atmospheric CO2 uptake as input parameters. The numerical tool used in order to model and simulate the leaching behaviour was PHREEQC, coupled with the Lawrence Livermore National Laboratory (LLNL) thermodynamic data base. The simulation results are satisfying and the paper demonstrates the feasibility of the modelling approach for the leaching behaviour assessment of concrete type construction materials.

  11. Persistence of initial conditions in continental scale air quality simulations

    NASA Astrophysics Data System (ADS)

    Hogrefe, Christian; Roselle, Shawn J.; Bash, Jesse O.

    2017-07-01

    This study investigates the effect of initial conditions (IC) for pollutant concentrations in the atmosphere and soil on simulated air quality for two continental-scale Community Multiscale Air Quality (CMAQ) model applications. One of these applications was performed for springtime and the second for summertime. Results show that a spin-up period of ten days commonly used in regional-scale applications may not be sufficient to reduce the effects of initial conditions to less than 1% of seasonally-averaged surface ozone concentrations everywhere while 20 days were found to be sufficient for the entire domain for the spring case and almost the entire domain for the summer case. For the summer case, differences were found to persist longer aloft due to circulation of air masses and even a spin-up period of 30 days was not sufficient to reduce the effects of ICs to less than 1% of seasonally-averaged layer 34 ozone concentrations over the southwestern portion of the modeling domain. Analysis of the effect of soil initial conditions for the CMAQ bidirectional NH3 exchange model shows that during springtime they can have an important effect on simulated inorganic aerosols concentrations for time periods of one month or longer. The effects are less pronounced during other seasons. The results, while specific to the modeling domain and time periods simulated here, suggest that modeling protocols need to be scrutinized for a given application and that it cannot be assumed that commonly-used spin-up periods are necessarily sufficient to reduce the effects of initial conditions on model results to an acceptable level. What constitutes an acceptable level of difference cannot be generalized and will depend on the particular application, time period and species of interest. Moreover, as the application of air quality models is being expanded to cover larger geographical domains and as these models are increasingly being coupled with other modeling systems to better represent

  12. 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.

  13. 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.

  14. 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

  15. 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…

  16. 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…

  17. Computer simulation and discrete-event models in the analysis of a mammography clinic patient flow.

    PubMed

    Coelli, Fernando C; Ferreira, Rodrigo B; Almeida, Renan Moritz V R; Pereira, Wagner Coelho A

    2007-09-01

    This work develops a discrete-event computer simulation model for the analysis of a mammography clinic performance. Two mammography clinic computer simulation models were developed, based on an existing public sector clinic of the Brazilian Cancer Institute, located in Rio de Janeiro city, Brazil. Two clinics in a total of seven configurations (number of equipment units and working personnel) were studied. Models tried to simulate changes in patient arrival rates, number of equipment units, available personnel (technicians and physicians), equipment maintenance scheduling schemes and exam repeat rates. Model parameters were obtained by direct measurements and literature reviews. A commercially-available simulation software was used for model building. The best patient scheduling (patient arrival rate) for the studied configurations had an average of 29 min for Clinic 1 (consisting of one mammography equipment, one to three technicians and one physician) and 21 min for Clinic 2 (two mammography equipment units, one to four technicians and one physician). The exam repeat rates and equipment maintenance scheduling simulations indicated that a large impact over patient waiting time would appear in the smaller capacity configurations. Discrete-event simulation was a useful tool for defining optimal operating conditions for the studied clinics, indicating the most adequate capacity configurations and equipment maintenance schedules.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Simulation-based medical education in clinical skills laboratory.

    PubMed

    Akaike, Masashi; Fukutomi, Miki; Nagamune, Masami; Fujimoto, Akiko; Tsuji, Akiko; Ishida, Kazuko; Iwata, Takashi

    2012-01-01

    Clinical skills laboratories have been established in medical institutions as facilities for simulation-based medical education (SBME). SBME is believed to be superior to the traditional style of medical education from the viewpoint of the active and adult learning theories. SBME can provide a learning cycle of debriefing and feedback for learners as well as evaluation of procedures and competency. SBME offers both learners and patients a safe environment for practice and error. In a full-environment simulation, learners can obtain not only technical skills but also non-technical skills, such as leadership, team work, communication, situation awareness, decision-making, and awareness of personal limitations. SBME is also effective for integration of clinical medicine and basic medicine. In addition, technology-enhanced simulation training is associated with beneficial effects for outcomes of knowledge, skills, behaviors, and patient-related outcomes. To perform SBME, effectively, not only simulators including high-fidelity mannequin-type simulators or virtual-reality simulators but also full-time faculties and instructors as professionals of SBME are essential in a clinical skills laboratory for SBME. Clinical skills laboratory is expected to become an integrated medical education center to achieve continuing professional development, integrated learning of basic and clinical medicine, and citizens' participation and cooperation in medical education.

  4. Wheelchair Transfer Simulations to Enhance Procedural Skills and Clinical Reasoning.

    PubMed

    Baird, Joanne M; Raina, Ketki D; Rogers, Joan C; O'Donnell, John; Holm, Margo B

    2015-01-01

    We describe an educational intervention that involved simulation scenarios of medically complex patients to teach transfer training and promote clinical reasoning. Scenarios were developed with practitioner input that described (1) a patient who was acutely ill, (2) a critical medical management event that occurred during a bed-to-wheelchair transfer of the patient, and (3) an occupational need. Transfer training, using the scenarios, occurred in a high-technology laboratory with SimMan(®) and a mock hospital suite. Evaluation was based on student performance and perceptions of simulation effectiveness. On average, students completed 66%-88% of the transfer items correctly. Student performance suggested that the simulation scenarios were more difficult than practitioners rated them. Students rated the simulation scenarios as effective teaching tools. Scenario use in simulations for transfer training makes a positive curricular contribution to teaching procedural skills and clinical reasoning simultaneously. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. Multi-scale initial conditions for cosmological simulations

    NASA Astrophysics Data System (ADS)

    Hahn, Oliver; Abel, Tom

    2011-08-01

    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 10-4 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. The simulated clinical environment as a platform for refining critical thinking in nursing students: a pilot program.

    PubMed

    Wane, Daryle; Lotz, Karen

    2013-01-01

    This research explores the use of clinical simulations as a platform for stimulating critical thinking in nursing students. This study takes place in an associate degree nursing program with a clinical group of nursing students. Utilizing a faculty partnership approach, information was presented to the clinical group. Students were divided into small groups to create simulation scenarios. Students were able to appreciate complexity of care and research differential diagnoses as they applied to care and management of changes in client condition scenarios. Use of a small-group teaching method to develop, implement, and critique clinical simulation scenarios facilitated critical thinking and clinical judgment of nursing students.

  18. 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.

  19. The impact of simulation sequencing on perceived clinical decision making.

    PubMed

    Woda, Aimee; Hansen, Jamie; Paquette, Mary; Topp, Robert

    2017-09-01

    An emerging nursing education trend is to utilize simulated learning experiences as a means to optimize competency and decision making skills. The purpose of this study was to examine differences in students' perception of clinical decision making and clinical decision making-related self-confidence and anxiety based on the sequence (order) in which they participated in a block of simulated versus hospital-based learning experiences. A quasi-experimental crossover design was used. Between and within group differences were found relative to self-confidence with the decision making process. When comparing groups, at baseline the simulation followed by hospital group had significantly higher self-confidence scores, however, at 14-weeks both groups were not significantly different. Significant within group differences were found in the simulation followed by hospital group only, demonstrating a significant decrease in clinical decision making related anxiety across the semester. Finally, there were no significant difference in; perceived clinical decision making within or between the groups at the two measurement points. Preliminary findings suggest that simulated learning experiences can be offered with alternating sequences without impacting the process, anxiety or confidence with clinical decision making. This study provides beginning evidence to guide curriculum development and allow flexibility based on student needs and available resources. Copyright © 2017. Published by Elsevier Ltd.

  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. Magnitude of reactive thrombocytosis and associated clinical conditions in dogs.

    PubMed

    Athanasiou, Labrini V; Polizopoulou, Zoe S; Papavasileiou, Eleftheria G; Mpairamoglou, Efstathios L; Kantere, Maria C; Rousou, Xanthi A

    2017-09-09

    Previous studies on the underlying causes of thrombocytosis have raised scientific interest in its clinical relevance in dogs. The purpose of this study was: (1) to explore the clinical conditions associated with thrombocytosis; (2) to compare platelet counts among these conditions; and (3) to identify possible interactions with other haematological variables and associated conditions. Medical records of 195 dogs with thrombocytosis (platelet count >500×10(3)/μL) were reviewed for signalment, complete blood count results and definitive diagnosis. The prevalence of thrombocytosis was 6.02%. All cases included had reactive thrombocytosis, with non-neoplastic, non-inflammatory underlying conditions in 48.2%, inflammatory processes in 34.4% and neoplastic processes in 17.4%. Haemoglobin and white blood cell counts were negatively and positively associated with platelet count, respectively. This study revealed that mean platelet count in dogs with neoplasia and a packed cell volume of 35% or below was significantly higher than that for dogs with other disease categories. Therefore, for dogs with marked thrombocytosis and anaemia, it is recommended that neoplasia should be included in the list of differential diagnoses. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. 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.

  3. 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

  4. Evaluation of ergonomic dental stools through clinical simulation.

    PubMed

    Parsell, D E; Weber, M D; Anderson, B C; Cobb, G W

    2000-01-01

    Work-related musculoskeletal pain occurs commonly within the dental community. Three stool designs were utilized in this study: a standard dental stool, a stool with dual arm supports, and a stool with dual arm supports and chest support. Electromyographic data from four muscle groups were collected on 13 clinicians during a simulated crown preparation procedure. Clinical simulation suggests that a potential musculoskeletal benefit to the clinician exists through utilization of dental stool designs which incorporate static arm supports.

  5. 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.

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

    PubMed

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

    2016-01-01

    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. 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. This study was a non-randomized study using historical controls to evaluate curricular change. The control group received lecture (n l=515) and the intervention group received lecture plus a simulation exercise (n l+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. 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). 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.

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

    PubMed

    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 (n l=515) and the intervention group received lecture plus a simulation exercise (n l+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.

  8. 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

  9. 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.

  10. Elasticity/distensibility of the ascending aorta: basal conditions and simulated conditions from space flights.

    PubMed

    Alessandri, N; Tufano, F; Petrassi, M; Alessandri, C; Lanzi, L; Fusco, L; Moscariello, F; De Angelis, C; Tomao, E

    2010-05-01

    The hysto-morfological composition of the ascending aorta wall gives to the vessel its characteristic elasticity/distensibility, which is deteriorated due to both physiological (age) and pathological events (hypertension, diabetes, dyslipidemia). This contributes to reduce the wall elasticity and to occurrence of cardiovascular events. Thirty young healthy subjects (20 males, 10 females, age <30 yr), were subjected to different postural conditions with and without Lower Body Negative Pressure (LBNP) with conventional procedures, to simulate the microgravity conditions in space flight. During this procedure the cardiovascular parameters and the aorta elasticity were assessed with ecocardiography. The observation of results and statistical comparison showed that despite different hemodynamic conditions and with significant variation of blood pressure related to posture, elasticity/distensibility did not change significantly. The elasticity/distensibility of arterial vessels is the result of two interdependent variables such as blood pressure and systolic and diastolic diameters. While blood pressure and heart rate vary physiologically in relation to posture, the compensation of the vessel diameters modifications maintains the aortic compliance invariate. Therefore, in young healthy people, despite the significant postural and the sudden pressure changes (equivalent to parietal stress) aortic compliance does not alter. This behavior might be related to the low rate of cardiovascular events that are present in healthy people aged under 30 yrs.

  11. CO2/ brine substitution experiments at simulated reservoir conditions

    NASA Astrophysics Data System (ADS)

    Kummerow, Juliane; Spangenberg, Erik

    2015-04-01

    Capillary properties of rocks affect the mobility of fluids in a reservoir. Therefore, the understanding of the capillary pressure behaviour is essential to assess the long-term behaviour of CO2 reservoirs. Beyond this, a calibration of the petrophysical properties on water saturation of reservoir rocks at simulated in situ conditions is crucial for a proper interpretation of field monitoring data. We present a set-up, which allows for the combined measurements of capillary pressure, electric resistivity, and elastic wave velocities under controlled reservoir conditions (pconf = 400 bar, ppore = 180 bar, T = 65 ° C) at different brine-CO2 saturations. The capillary properties of the samples are measured using the micropore membrane technique. The sample is jacketed with a Viton tube (thickness = 4 mm) and placed between two current electrode endcaps, which as well contain pore fluid ports and ultrasonic P and S wave transducers. Between the sample and the lower endcap the hydrophilic semi-permeable micro-pore membrane (pore size = 100 nm) is integrated. It is embedded into filter papers to establish a good capillary contact and to protect the highly sensitive membrane against mechanical damage under load. Two high-precision syringe pumps are used to displace a quantified volume of brine by CO2 and determine the corresponding sample saturation. The fluid displacement induces a pressure gradient along the sample, which corresponds to the capillary pressure at a particular sample saturation. It is measured with a differential pressure sensor in the range between 0 - 0.2 MPa. Drainage and imbibition cycles are performed to provide information on the efficiency of capillary trapping and to get a calibration of the petrophysical parameters of the sample.

  12. 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

  13. 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

  14. 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.

  15. Photodegradation of clothianidin under simulated California rice field conditions.

    PubMed

    Mulligan, Rebecca A; Redman, Zachary C; Keener, Megan R; Ball, David B; Tjeerdema, Ronald S

    2016-07-01

    Photodegradation can be a major route of dissipation for pesticides applied to shallow rice field water, leading to diminished persistence and reducing the risk of offsite transport. The objective of this study was to characterize the aqueous-phase photodegradation of clothianidin under simulated California rice field conditions. Photodegradation of clothianidin was characterized in deionized, Sacramento River and rice field water samples. Pseudo-first-order rate constants and DT50 values in rice field water (mean k = 0.0158 min(-1) ; mean DT50 = 18.0 equivalent days) were significantly slower than in deionized water (k = 0.0167 min(-1) ; DT50 = 14.7 equivalent days) and river water (k = 0.0146 min(-1) ; DT50 = 16.6 equivalent days) samples. Quantum yield ϕc values demonstrate that approximately 1 and 0.5% of the light energy absorbed results in photochemical transformation in pure and field water respectively. Concentrations of the photodegradation product thiazolymethylurea in aqueous photolysis samples were determined using liquid chromatography-tandem mass spectrometry and accounted for ≤17% in deionized water and ≤8% in natural water. Photodegradation rates of clothianidin in flooded rice fields will be controlled by turbidity and light attenuation. Aqueous-phase photodegradation may reduce the risk of offsite transport of clothianidin from flooded rice fields (via drainage) and mitigate exposure to non-target organisms. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  16. 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.

  17. 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.

  18. Simulating and cataloguing the background solar wind conditions

    NASA Astrophysics Data System (ADS)

    Pinto, Rui; Rouillard, Alexis; Odstrcil, Dusan; Mays, Leila

    2017-04-01

    I will present a new series of solar wind simulations used to build a catalogue of the background solar wind from the surface of the Sun to 1 AU. We used a new solar wind model, called MULTI-VP, which takes a coronal magnetic field map as input and calculates the dynamical and thermal properties of the solar wind from the chromosphere up to about 30 Rsun. MULTI-VP supplies the full set of physical inner boundary conditions required to initiate the model ENLIL, which was then used to calculate the properties of the wind flow in the heliosphere (from 21.5 Rsun to 1AU). This combined modelling strategy does not rely on semi-empirical assumptions for the state of the solar wind at the high corona, and provides new estimates of the state of the background wind which are based only on physical principles. MULTI-VP was initiated using Potential Field Source-Surface extrapolations from WSO synoptic maps covering several Carrington rotations both at solar minimum and at solar maximum (CR 2055 - 2079 and CR 2130 - 2149; see https://stormsweb.irap.omp.eu/doku.php?id=windmaptable). Our solutions were calibrated against in-situ measurements of different spacecrafts, white-light J-Maps and coronal/heliospheric imagery in order to provide better predictions than the classical methods. These wind solution will be available as HELCATS catalogues (http://www.helcats-fp7.eu/).

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. Simulated Firefighting Task Performance and Physiology Under Very Hot Conditions

    PubMed Central

    Larsen, Brianna; Snow, Rod; Williams-Bell, Michael; Aisbett, Brad

    2015-01-01

    Purpose: To assess the impact of very hot (45°C) conditions on the performance of, and physiological responses to, a simulated firefighting manual-handling task compared to the same work in a temperate environment (18°C). Methods: Ten male volunteer firefighters performed a 3-h protocol in both 18°C (CON) and 45°C (VH). Participants intermittently performed 12 × 1-min bouts of raking, 6 × 8-min bouts of low-intensity stepping, and 6 × 20-min rest periods. The area cleared during the raking task determined work performance. Core temperature, skin temperature, and heart rate were measured continuously. Participants also periodically rated their perceived exertion (RPE) and thermal sensation. Firefighters consumed water ad libitum. Urine specific gravity (USG) and changes in body mass determined hydration status. Results: Firefighters raked 19% less debris during the VH condition. Core and skin temperature were 0.99 ± 0.20 and 5.45 ± 0.53°C higher, respectively, during the VH trial, and heart rate was 14–36 beats.min−1 higher in the VH trial. Firefighters consumed 2950 ± 1034 mL of water in the VH condition, compared to 1290 ± 525 in the CON trial. Sweat losses were higher in the VH (1886 ± 474 mL) compared to the CON trial (462 ± 392 mL), though both groups were hydrated upon protocol completion (USG < 1.020). Participants' average RPE was higher in the VH (15.6 ± 0.9) compared to the CON trial (12.6 ± 0.9). Similarly, the firefighers' thermal sensation scores were significantly higher in the VH (6.4 ± 0.5) compared to the CON trial (4.4 ± 0.4). Conclusions: Despite the decreased work output and aggressive fluid replacement observed in the VH trial, firefighters' experienced increases in thermal stress, and exertion. Fire agencies should prioritize the health and safety of fire personnel in very hot temperatures, and consider the impact of reduced productivity on fire suppression efforts. PMID:26617527

  5. 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

  6. 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

  7. 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.

  8. Saccharomyces boulardii CNCM I-745 in different clinical conditions.

    PubMed

    Dinleyici, Ener Cagri; Kara, Ates; Ozen, Metehan; Vandenplas, Yvan

    2014-11-01

    Saccharomyces boulardii is a well-known probiotic worldwide, and there are numerous studies including experimental and clinical trials in children and adults by the use of S. boulardii. The objective of the present report is to provide an update on the evidence for the efficacy of S. boulardii CNCM I-745 in different clinical conditions. Saccharomyces boulardii is one of the best-studied probiotics in acute gastroenteritis (AGE) and is shown to be safe and to reduce the duration of diarrhea and hospitalization by about 1 day. Saccharomyces boulardii is one of the recommended probiotics for AGE in children by European Society of Paediatric Infectious Diseases and European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). Saccharomyces boulardii is also a recommended probiotic for the prevention of antibiotic-associated diarrhea (AAD), and a recent study showed promising results for the treatment of AAD in children. There is insufficient evidence to recommend the long-term use of S. boulardii in patients with irritable bowel syndrome. Although some clinical studies showed positive effects of S. boulardii on inflammation, there is no clinical evidence that S. boulardii is useful in inflammatory bowel disease. Saccharomyces boulardii could be used in patients needing Helicobacter pylori eradication because the S. boulardii improves compliance, decreases the side effects and moderately increases the eradication rate. There are new promising results (improving feeding tolerance, shorten the course of hyperbilirubinemia), but we do still not recommend the routine use of S. boulardii in newborns. Saccharomyces boulardii CNCM I-745 is a good example for the statement that each probiotic needs to be taxonomically characterized and its efficacy and safety should be documented individually in different clinical settings.

  9. 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.

  10. 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)

  11. 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)

  12. Simulating Clinical Trials With and Without Intracranial EEG Data.

    PubMed

    Goldenholz, Daniel M; Tharayil, Joseph J; Kuzniecky, Rubin; Karoly, Philippa; Theodore, William H; Cook, Mark J

    2017-06-01

    It is currently unknown if knowledge of clinically silent (electrographic) seizures improves the statistical efficiency of clinical trials. Using data obtained from 10 patients with chronically implanted subdural electrodes over an average of 1 year, a Monte Carlo bootstrapping simulation study was performed to estimate the statistical power of running a clinical trial based on A) patient reported seizures with intracranial EEG (icEEG) confirmation, B) all patient reported events, or C) all icEEG confirmed seizures. A "drug" was modeled as having 10%, 20%, 30%, 40% and 50% efficacy in 1000 simulated trials each. Outcomes were represented as percentage of trials that achieved p<0.05 using Fisher Exact test for 50%-responder rates (RR50), and Wilcoxon Rank Sum test for median percentage change (MPC). At each simulated drug strength, the MPC method showed higher power than RR50. As drug strength increased, statistical power increased. For all cases except RR50 with drug of 10% efficacy, using patient reported events (with or without icEEG confirmation) was not as statistically powerful as using all available intracranially confirmed seizures (p<0.001). This study demonstrated using simulation that additional accuracy in seizure detection using chronically implanted icEEG improves statistical power of clinical trials. Newer invasive and noninvasive seizure detection devices may have the potential to provide greater statistical efficiency, accelerate drug discovery and lower trial costs.

  13. Natural Language Processing Framework to Assess Clinical Conditions

    PubMed Central

    Ware, Henry; Mullett, Charles J.; Jagannathan, V.

    2009-01-01

    Objective The authors developed a natural language processing (NLP) framework that could be used to extract clinical findings and diagnoses from dictated physician documentation. Design De-identified documentation was made available by i2b2 Bio-informatics research group as a part of their NLP challenge focusing on obesity and its co-morbidities. The authors describe their approach, which used a combination of concept detection, context validation, and the application of a variety of rules to conclude patient diagnoses. Results The framework was successful at correctly identifying diagnoses as judged by NLP challenge organizers when compared with a gold standard of physician annotations. The authors overall kappa values for agreement with the gold standard were 0.92 for explicit textual results and 0.91 for intuited results. The NLP framework compared favorably with those of the other entrants, placing third in textual results and fourth in intuited results in the i2b2 competition. Conclusions The framework and approach used to detect clinical conditions was reasonably successful at extracting 16 diagnoses related to obesity. The system and methodology merits further development, targeting clinically useful applications. PMID:19390100

  14. 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

  15. 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

  16. Outcomes of clinical simulation for novice nursing students: communication, confidence, clinical judgment.

    PubMed

    Bambini, Deborah; Washburn, Joy; Perkins, Ronald

    2009-01-01

    The use of clinical simulation in nursing education provides many opportunities for students to learn and apply theoretical principles of nursing care in a safe environment. The purpose of this study was to evaluate simulated clinical experiences as a teaching/learning method to increase the self-efficacy of nursing students during their initial clinical course in a prelicensure program. An integrated, quasi-experimental, repeated measures design was used. A sample of 112 students completed surveys, indicating their confidence in various skills necessary for postpartum and newborn nursing, both before and after the simulation experience. Results indicated that students experienced a significant increase in overall self-efficacy (p < .01). Students also experienced an increase in confidence in assessing vital signs (p < .01), breasts (p < .01), the fundus (p < .001), and lochia (p < .001), and in providing patient education (p < .001). Three themes that emerged in the qualitative results were communication, confidence, and clinical judgment.

  17. 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

  18. 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 simulation...

  19. Simulation debriefing for clinical judgment development: A concept analysis.

    PubMed

    Al Sabei, Sulaiman D; Lasater, Kathie

    2016-10-01

    The aim of this review was to provide an in-depth analysis of debriefing in nursing simulation-based learning. Specifically, the authors sought to describe the debriefing concept within the context of enhancing nursing students' clinical judgment skill. Concept analysis. A literature review was conducted using five electronic databases with the addition of references for relevant papers reviewed. Medline Ovid, Cumulative Index to Nursing and Allied Health (CINAHL) Plus, Educational Resources Information Center (ERIC), ScienceDirect and Google Scholar were searched for articles published in English between 2005 and 2015. Search terms included clinical judgment, debriefing, and simulation. The Walker and Avant systematic approach was utilized as a concept analysis framework. The analysis informed how the concept is defined in the existing literature. The search resulted in a total of 47 articles. The concept of debriefing was analyzed using seven themes from Walker and Avant: concept definition, defining attributes, antecedents, consequences, empirical referents, uses of the concept, and a model case. Based on the analysis, an integrative simulation debriefing guide for promoting students' clinical judgment was presented as a vehicle for a consistent approach. This review identified simulation debriefing as a structured and guided reflection process in which students actively appraise their cognitive, affective, and psychomotor performance within the context of their clinical judgment skill. Reflective debriefing provides students with an opportunity to assume an active role during the learning process. Following a structured debriefing guide can help educators and even students facilitate a learning environment that enhances students' clinical judgment development. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The Crucible simulation: Behavioral simulation improves clinical leadership skills and understanding of complex health policy change.

    PubMed

    Cohen, Daniel; Vlaev, Ivo; McMahon, Laurie; Harvey, Sarah; Mitchell, Andy; Borovoi, Leah; Darzi, Ara

    2017-05-11

    The Health and Social Care Act 2012 represents the most complex National Health Service reforms in history. High-quality clinical leadership is important for successful implementation of health service reform. However, little is known about the effectiveness of current leadership training. This study describes the use of a behavioral simulation to improve the knowledge and leadership of a cohort of medical doctors expected to take leadership roles in the National Health Service. A day-long behavioral simulation (The Crucible) was developed and run based on a fictitious but realistic health economy. Participants completed pre- and postsimulation questionnaires generating qualitative and quantitative data. Leadership skills, knowledge, and behavior change processes described by the "theory of planned behavior" were self-assessed pre- and postsimulation. Sixty-nine medical doctors attended. Participants deemed the simulation immersive and relevant. Significant improvements were shown in perceived knowledge, capability, attitudes, subjective norms, intentions, and leadership competency following the program. Nearly one third of participants reported that they had implemented knowledge and skills from the simulation into practice within 4 weeks. This study systematically demonstrates the effectiveness of behavioral simulation for clinical management training and understanding of health policy reform. Potential future uses and strategies for analysis are discussed. High-quality care requires understanding of health systems and strong leadership. Policymakers should consider the use of behavioral simulation to improve understanding of health service reform and development of leadership skills in clinicians, who readily adopt skills from simulation into everyday practice.

  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. Students' experiences of learning manual clinical skills through simulation.

    PubMed

    Johannesson, Eva; Silén, Charlotte; Kvist, Joanna; Hult, Håkan

    2013-03-01

    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 thoughts about their learning through simulation skills training. The study was designed for an educational setting at a clinical skills centre. Ten third-year undergraduate nursing students performed urethral catheterisation, using the virtual reality simulator UrecathVision™, which has haptic properties. The students practised in pairs. Each session was videotaped and the video was used to stimulate recall in subsequent interviews. The interviews were analysed using qualitative content analysis. The analysis from interviews resulted in three themes: what the students learn, how the students learn, and the simulator's contribution to the students' learning. Students learned manual skills, how to perform the procedure, and professional behaviour. They learned by preparing, watching, practising and reflecting. The simulator contributed by providing opportunities for students to prepare for the skills training, to see anatomical structures, to feel resistance, and to become aware of their own performance ability. The findings show that the students related the task to previous experiences, used sensory information, tested themselves and practised techniques in a hands-on fashion, and reflected in and on action. The simulator was seen as a facilitator to learning the manual skills. The study design, with students working in pairs combined with video recording, was found to enhance opportunities for reflection.

  3. Animated-simulation modeling facilitates clinical-process costing.

    PubMed

    Zelman, W N; Glick, N D; Blackmore, C C

    2001-09-01

    Traditionally, the finance department has assumed responsibility for assessing process costs in healthcare organizations. To enhance process-improvement efforts, however, many healthcare providers need to include clinical staff in process cost analysis. Although clinical staff often use electronic spreadsheets to model the cost of specific processes, PC-based animated-simulation tools offer two major advantages over spreadsheets: they allow clinicians to interact more easily with the costing model so that it more closely represents the process being modeled, and they represent cost output as a cost range rather than as a single cost estimate, thereby providing more useful information for decision making.

  4. Patient-individualized boundary conditions for CFD simulations using time-resolved 3D angiography.

    PubMed

    Boegel, Marco; Gehrisch, Sonja; Redel, Thomas; Rohkohl, Christopher; Hoelter, Philip; Doerfler, Arnd; Maier, Andreas; Kowarschik, Markus

    2016-06-01

    Hemodynamic simulations are of increasing interest for the assessment of aneurysmal rupture risk and treatment planning. Achievement of accurate simulation results requires the usage of several patient-individual boundary conditions, such as a geometric model of the vasculature but also individualized inflow conditions. We propose the automatic estimation of various parameters for boundary conditions for computational fluid dynamics (CFD) based on a single 3D rotational angiography scan, also showing contrast agent inflow. First the data are reconstructed, and a patient-specific vessel model can be generated in the usual way. For this work, we optimize the inflow waveform based on two parameters, the mean velocity and pulsatility. We use statistical analysis of the measurable velocity distribution in the vessel segment to estimate the mean velocity. An iterative optimization scheme based on CFD and virtual angiography is utilized to estimate the inflow pulsatility. Furthermore, we present methods to automatically determine the heart rate and synchronize the inflow waveform to the patient's heart beat, based on time-intensity curves extracted from the rotational angiogram. This will result in a patient-individualized inflow velocity curve. The proposed methods were evaluated on two clinical datasets. Based on the vascular geometries, synthetic rotational angiography data was generated to allow a quantitative validation of our approach against ground truth data. We observed an average error of approximately [Formula: see text] for the mean velocity, [Formula: see text] for the pulsatility. The heart rate was estimated very precisely with an average error of about [Formula: see text], which corresponds to about 6 ms error for the duration of one cardiac cycle. Furthermore, a qualitative comparison of measured time-intensity curves from the real data and patient-specific simulated ones shows an excellent match. The presented methods have the potential to accurately

  5. 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

  6. 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.

  7. Simulation-Based Assessment of ECMO Clinical Specialists.

    PubMed

    Fehr, James J; Shepard, Mark; McBride, Mary E; Mehegan, Mary; Reddy, Kavya; Murray, David J; Boulet, John R

    2016-06-01

    The aims of the study were (1) to create multiple scenarios that simulate a range of urgent and emergent extracorporeal membrane oxygenation (ECMO) events and (2) to determine whether these scenarios can provide reliable and valid measures of a specialist's advanced skill in managing ECMO emergencies. Multiscenario simulation-based performance assessment was performed. The study was conducted in the Saigh Pediatric Simulation Center at St. Louis Children's Hospital. ECMO clinical specialists participated in the study. Twenty-five ECMO specialists completed 8 scenarios presenting acute events in simulated ECMO patients. Participants were evaluated by 2 separate reviewers for completion of key actions and for global performance. The scores were highest for the hemodilution scenario, whereas the air entrainment scenario had the lowest scores. Psychometric analysis demonstrated that ECMO specialists with more than 1 year of experience outperformed the specialists with less than 1 year of experience. Participants endorsed these sessions as important and representative of events that might be encountered in practice. The scenarios could serve as a component of an ECMO education curriculum and be used to assess clinical specialists' readiness to manage ECMO emergencies.

  8. Enhancing nursing informatics competencies and critical thinking skills using wireless clinical simulation laboratories.

    PubMed

    Cholewka, Patricia A; Mohr, Bernard

    2009-01-01

    Nursing students at New York City College of Technology are assigned client care experiences that focus on common alterations in health status. However, due to the unpredictability of client census within any healthcare facility, it is not possible for all students to have the same opportunity to care for clients with specific medical conditions. But with the use of patient simulators in a dedicated Clinical Simulation Laboratory setting, students can be universally, consistently, and repeatedly exposed to programmed scenarios that connect theory with the clinical environment. Outcomes from using patient simulators include improved nursing knowledge base, enhanced critical thinking, reflective learning, and increased understanding of information technology for using a Personal Digital Assistant and documenting care by means of an electronic Patient Record System. An innovative nursing education model using a wireless, inter-connective data network was developed by this college in response to the need for increasing nursing informatics competencies and critical thinking skills by students in preparation for client care.

  9. Preventive and promotive medicine in ambulatory clinical practice: a prospective simulated patient study.

    PubMed

    Wong, Y Y; Nordin, M; Suleiman, A B

    1995-12-01

    This study examines the extent to which preventive and promotive advice is integrated into the clinical practice of doctors. Using a cross-sectional descriptive survey design, the study compares the performance of doctors in giving healthy lifestyle advice for five clinical conditions, their perceived practice and their rating on the importance of disseminating selected key lifestyle messages. A total of 28 volunteers were trained to simulate the five clinical conditions which required related health advice and to rate the doctors' performance with the use of a prepared checklist. Simulated patient ratings of 343 doctor-patient encounters provided the data on doctors' health promotion efforts for the selected clinical conditions. A post-visit self-administered questionnaire survey of a sub-sample of 100 doctors gave an insight into their opinions and perceived practice. Only in 49% of the instances was a health promotion message given. The doctors' encouraging interest in health education and health promotion and their positive perceptions of their volume of healthy lifestyle counselling were not borne out in actual clinical practice. The results indicate that the extent of preventive and promotive health education in both the public and private health sectors is unacceptably low. The matter needs to be addressed through training programmes as well as the formulation of clear health promotion priorities and strategies in Malaysia.

  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. 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.

  12. Multimillion to billion atom simulations of nanosystems under extreme conditions

    NASA Astrophysics Data System (ADS)

    Vashishta, P.

    2008-12-01

    Advanced materials and devices with nanometer grain/feature sizes are being developed to achieve higher strength and toughness in ceramic materials and greater speeds in electronic devices. Below 100 nm, however, continuum description of materials and devices must be supplemented by atomistic descriptions. Current state of the art atomistic simulations involve 10 million - 1 billion atoms. We investigate initiation, growth and healing of wing cracks in confined silica glass by multimillion atom molecular dynamics (MD) simulations. Under dynamic compression, frictional sliding of pre-crack surfaces nucleates nanovoids, which evolve into nanocrack columns at the pre-crack tip. Nanocrack columns merge to form a wing crack, which grows via coalescence with nanovoids in the direction of maximum compression. Lateral confinement arrests the growth and partially heals the wing crack. Growth and arrest of the wing crack occur repeatedly, as observed in dynamic compression experiments on brittle solids under lateral confinement. MD simulation of hypervelocity projectile impact in aluminum nitride and alumina has also been studied. The simulations reveal strong interplay between shock- induced structural phase transformation, plastic deformation and brittle cracks. The shock wave splits into an elastic precursor and a wurtzite-to-rocksalt structural transformation wave. When the elastic wave reflected from the boundary of the sample interacts with the transformation wave front, nanocavities are generated along the penetration path of the projectile and dislocations in adjacent regions. The nanocavities coalesce to form mode I brittle cracks while dislocations generate kink bands that give rise to mode II cracks. These simulations provide a microscopic view of defects associated with simultaneous tensile and shear cracking at the structural phase transformation boundary due to shock impact in high-strength ceramics. Initiation of chemical reactions at shock fronts prior to

  13. [Innovation in healthcare processes and patient safety using clinical simulation].

    PubMed

    Rojo, E; Maestre, J M; Díaz-Mendi, A R; Ansorena, L; Del Moral, I

    2016-01-01

    Many excellent ideas are never implemented or generalised by healthcare organisations. There are two related paradigms: thinking that individuals primarily change through accumulating knowledge, and believing that the dissemination of that knowledge within the organisation is the key element to facilitate change. As an alternative, a description and evaluation of a simulation-based inter-professional team training program conducted in a Regional Health Service to promote and facilitate change is presented. The Department of Continuing Education completed the needs assessment using the proposals presented by clinical units and management. Skills and behaviors that could be learned using simulation were selected, and all personnel from the units participating were included. Experiential learning principles based on clinical simulation and debriefing, were used for the instructional design. The Kirkpatrick model was used to evaluate the program. Objectives included: a) decision-making and teamwork skills training in high prevalence diseases with a high rate of preventable complications; b) care processes reorganisation to improve efficiency, while maintaining patient safety; and, c) implementation of new complex techniques with a long learning curve, and high preventable complications rate. Thirty clinical units organised 39 training programs in the 3 public hospitals, and primary care of the Regional Health Service during 2013-2014. Over 1,559 healthcare professionals participated, including nursing assistants, nurses and physicians. Simulation in healthcare to train inter-professional teams can promote and facilitate change in patient care, and organisational re-engineering. Copyright © 2016 SECA. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Obesity induction in hamster that mimics the human clinical condition.

    PubMed

    Jordania da Silva, Vivian; Dias, Sílvia Regina Costa; Maioli, Tatiani Uceli; Serafim, Luciana Ribeiro; Furtado, Luis Fernando Viana; Quintão Silva, Maria da Gloria; Faria, Ana Maria Caetano de; Rabelo, Élida Mara Leite

    2017-08-05

    Although obesity is well established in hamsters, studies using diets with high levels of simple carbohydrate associated with lipids are necessary to assess the impact of this type of food in the body. In this study a high sugar and butter diet (HSB) and high temperature were employed towards this end. Obesity was successfully induced at a temperature of 30.3°C to 30.9°C after 38 days feeding the animals an HSB diet. It was shown that although diet is important for the induction of obesity, temperature is also essential because at a temperature slightly below the one required, obesity was not induced, even when the animals were fed for a longer period (150 days).The obese clinical condition was accompanied by biochemical and hematological changes, as increased cholesterol and triglyceride levels and increased leukocyte numbers, similar to alterations observed in obese humans. Furthermore, it was demonstrated that increasing the intake of simple carbohydrates associated with lipids provided evidence of inflammation in obese animals.

  15. Nitric oxide metabolites (nitrite and nitrate) in several clinical condition.

    PubMed

    Caimi, G; Hopps, E; Montana, M; Carollo, C; Calandrino, V; Incalcaterra, E; Canino, B; Lo Presti, R

    2014-01-01

    We determined the concentration of nitric oxide metabolites (NO2-+NO3-), expressed as NOx, in several clinical conditions. Regarding this, we have examined 25 subjects with arterial hypertension, 41 subjects with chronic kidney disease in conservative treatment, 106 subjects with metabolic syndrome subdivided according to the presence (n = 43) or not (n = 63) of diabetes mellitus, 48 subjects with obstructive sleep apnea syndrome (OSAS), 14 women with systemic sclerosis complicated with Raynaud's phenomenon, 42 dialyzed subjects and 105 young subjects with acute myocardial infarction (AMI). In subjects with arterial hypertension, chronic kidney disease, metabolic syndrome, systemic sclerosis, as well as, in dialyzed and AMI subjects, we found at baseline a NOx increase. In dyalized subjects after a standard dialysis session, we observed a decrease in NOx. The increase in NOx in juvenile AMI was significantly influenced by cigarette smoking and less by cardiovascular risk factors and the extent of coronary lesions; at 3 and 12 months later than the initial event, we observed a decrease of NOx that remains significantly higher than the control group. In subjects with OSAS no difference in NOx was noted in comparison with normal controls, although their subdivision according to the apnea/hypopnea index operates a clear distinction regarding NOx concentration.

  16. 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.

  17. 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.

  18. Sediment DSi and DIP fluxes under simulated redox conditions

    NASA Astrophysics Data System (ADS)

    Nteziryayo, Love-Raoul; Danielsson, Åsa

    2017-04-01

    The Baltic Sea is one of the most eutrophic water bodies in the world. This eutrophication of the Baltic Sea has resulted in the expansion of areas of hypoxic bottom waters. Hypoxia is known to cause the release of dissolved inorganic phosphorus (DIP) from sediment. It is largely assumed that dissolved silica (DSi) reacts in an analogous way in hypoxic conditions. From sediment incubation experiments, we found that P reacts faster to oxygen changes than Si. Here we show that DSi and DIP behave differently to changing oxygen concentrations in the bottom waters, and that the adsorption and de-sorption on Fe oxihydroxides may control the release of P more efficiently than of Si. The results showed that DSi fluxes were higher under oxic conditions (2.21±0.28 mmol Si m-2d-1) than under hypoxic conditions (1.36±0.29 mmol Si m-2d-1). The opposite was observed for P fluxes (0.06 ±0.01 and 0.10±0.09 mmol P m-2d-1) under oxic respective hypoxic conditions). Our results indicate that the increase of hypoxic conditions in coastal areas may directly cause the decrease of Si fluxes from sediment and thereby contribute to the diminishing Si concentrations observed in the Baltic Sea waters.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  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. Oxygen analyzers in anaesthesia: performance in a simulated clinical environment.

    PubMed

    Bengtson, J P; Sonander, H; Stenqvist, O

    1986-11-01

    Nine commercial oxygen analyzers were tested in a laboratory model stimulating clinical anaesthesia conditions. Fifteen test situations were used in order to study the effects of nitrous oxide, humidity, positive end-expiratory pressure, halothane, enflurane and isoflurane. Errors exceeding 8 vol% were not uncommon, the dominating source of error being humidity. Analyzers with efficient dehumidification of gases before analysis performed better than analyzers without this property.

  6. 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.

  7. 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.

  8. 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.

  9. 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)....

  10. 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)....

  11. 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)....

  12. 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.

  13. Monte Carlo simulation of a clinical linear accelerator.

    PubMed

    Lin, S Y; Chu, T C; Lin, J P

    2001-12-01

    The effects of the physical parameters of an electron beam from a Siemens PRIMUS clinical linear accelerator (linac) on the dose distribution in water were investigated by Monte Carlo simulation. The EGS4 user code, OMEGA/BEAM, was used in this study. Various incident electron beams, for example, with different energies, spot sizes and distances from the point source, were simulated using the detailed linac head structure in the 6 MV photon mode. Approximately 10 million particles were collected in the scored plane, which was set under the reticle to form the so-called phase space file. The phase space file served as a source for simulating the dose distribution in water using DOSXYZ. Dose profiles at Dmax (1.5 cm) and PDD curves were calculated following simulating about 1 billion histories for dose profiles and 500 million histories for percent depth dose (PDD) curves in a 30 x 30 x 30 cm3 water phantom. The simulation results were compared with the data measured by a CEA film and an ion chamber. The results show that the dose profiles are influenced by the energy and the spot size, while PDD curves are primarily influenced by the energy of the incident beam. The effect of the distance from the point source on the dose profile is not significant and is recommended to be set at infinity. We also recommend adjusting the beam energy by using PDD curves and, then, adjusting the spot size by using the dose profile to maintain the consistency of the Monte Carlo results and measured data.

  14. Effects of broken solenoidal condition of magnetic field in MHD simulation for large helical device plasmas

    NASA Astrophysics Data System (ADS)

    Takado, W.; Matsumoto, Y.; Watanabe, K. Y.; Tomioka, S.; Oikawa, S.

    2017-09-01

    We studied the effects of the broken solenoidal condition of a magnetic field in linear magnetohydrodynamics (MHD) simulations based on a real coordinate system for Large Helical Device plasmas. Artificial errors of various orders in this condition were introduced into linear MHD simulations and compared. Spurious Fourier modes were observed to be dominant because of the error in the condition. We suggested a criterion, which is expressed as the condition that the ratio of the error force to the Lorentz force is much smaller than 100%, for estimating an acceptable limit of the solenoidal condition error through the simulation results. The effects of a large error in the condition of the analysis of a specified single-mode instability were investigated in addition. Adding a large error in the condition resulted in certain undesirable modes becoming dominant, whereas the desirable mode did not dominate. Thus, a large error in the condition can be harmful to analysis with a focus on specified modes.

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. [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.

  3. 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

  4. Estimating blood loss after birth: using simulated clinical examples.

    PubMed

    Buckland, Sara S; Homer, Caroline S E

    2007-06-01

    To determine the accuracy of the estimation of blood loss using simulated clinical examples. Over 100 attendees came together at a seminar about postpartum haemorrhage in June 2006. Five blood loss assessment stations were constructed, each containing a simulated clinical example. Each station was numbered and was made up of a variety of equipment used in birthing suites. Over 5L of 'artificial' blood was made. The artificial blood was similar to the colour and consistency of real blood. A convenience sample of 88 participants was given a response sheet and asked to estimate blood loss at each station. Participants included midwives, student midwives and an obstetrician. Blood in a container (bedpan, kidney dish) was more accurately estimated than blood on sanitary pads, sheets or clothing. Lower volumes of blood were also estimated correctly by more participants than the higher volumes. Improvements are still needed in visual estimation of blood loss following childbirth. Education programs may increase the level of accuracy. We encourage other clinicians and educators to embark upon a similar exercise to assist midwives and others to improve their visual estimation of blood loss after birth. Accurate estimations can ensure that women who experience significant blood loss can receive appropriate care and the published rates of postpartum haemorrhage are correct.

  5. 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.

  6. 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.

  7. Auditory spatial discrimination by barn owls in simulated echoic conditions

    NASA Astrophysics Data System (ADS)

    Spitzer, Matthew W.; Bala, Avinash D. S.; Takahashi, Terry T.

    2003-03-01

    In humans, directional hearing in reverberant conditions is characterized by a ``precedence effect,'' whereby directional information conveyed by leading sounds dominates perceived location, and listeners are relatively insensitive to directional information conveyed by lagging sounds. Behavioral studies provide evidence of precedence phenomena in a wide range of species. The present study employs a discrimination paradigm, based on habituation and recovery of the pupillary dilation response, to provide quantitative measures of precedence phenomena in the barn owl. As in humans, the owl's ability to discriminate changes in the location of lagging sources is impaired relative to that for single sources. Spatial discrimination of lead sources is also impaired, but to a lesser extent than discrimination of lagging sources. Results of a control experiment indicate that sensitivity to monaural cues cannot account for discrimination of lag source location. Thus, impairment of discrimination ability in the two-source conditions most likely reflects a reduction in sensitivity to binaural directional information. These results demonstrate a similarity of precedence effect phenomena in barn owls and humans, and provide a basis for quantitative comparison with neuronal data from the same species.

  8. Auditory spatial discrimination by barn owls in simulated echoic conditions.

    PubMed

    Spitzer, Matthew W; Bala, Avinash D S; Takahashi, Terry T

    2003-03-01

    In humans, directional hearing in reverberant conditions is characterized by a "precedence effect," whereby directional information conveyed by leading sounds dominates perceived location, and listeners are relatively insensitive to directional information conveyed by lagging sounds. Behavioral studies provide evidence of precedence phenomena in a wide range of species. The present study employs a discrimination paradigm, based on habituation and recovery of the pupillary dilation response, to provide quantitative measures of precedence phenomena in the barn owl. As in humans, the owl's ability to discriminate changes in the location of lagging sources is impaired relative to that for single sources. Spatial discrimination of lead sources is also impaired, but to a lesser extent than discrimination of lagging sources. Results of a control experiment indicate that sensitivity to monaural cues cannot account for discrimination of lag source location. Thus, impairment of discrimination ability in the two-source conditions most likely reflects a reduction in sensitivity to binaural directional information. These results demonstrate a similarity of precedence effect phenomena in barn owls and humans, and provide a basis for quantitative comparison with neuronal data from the same species.

  9. 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}.

  10. 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.

  11. Development of a theoretical-practical script for clinical simulation.

    PubMed

    Fabri, Renata Paula; Mazzo, Alessandra; Martins, José Carlos Amado; Fonseca, Ariadne da Silva; Pedersoli, César Eduardo; Miranda, Fernanda Berchelli Girão; Fumincelli, Laís; Baptista, Rui Carlos Negrão

    2017-04-10

    To develop a theoretical-practical script based on the opinion of experts to be used in simulated clinical activities. Qualitative study through analysis of content of interviews with experts on the theme in order to develop the proposed script. Of the 24 invited experts, 12 specialists from educational institutions in Brazil and abroad participated in the study in compliance with the ethical precepts. The experts responded to questions on the characterization of their study attributes and described the items required for the development of a simulated scenario. In view of the responses obtained, data content was analyzed and classified into units and subunits of significance. The items mentioned for the development of the script generated seven units of significance. The units and subunits of significance were gathered in three stages of the main components of the simulated scenario: prior, preparation, and finals. This study enables an innovative, stimulating teaching experience, making it easier for professors to use the simulation resource as a learning process in an effective and objective manner, as a guide to professors and researchers in the area of clinical simulation. Construir, com base na opinião de peritos, roteiro teórico-prático para uso em atividade clínica simulada. Trata-se de um estudo qualitativo por meio de análise de conteúdo de entrevistas de peritos no assunto para construção do roteiro proposto. Seguido os preceitos éticos, entre os 24 peritos convidados pertencentes a instituições de ensino do Brasil e do exterior. Os peritos responderam a questões sobre a caracterização dos seus atributos de estudo e descreveram os itens imprescindíveis à construção de um cenário simulado. Diante das respostas obtidas, os dados foram analisados em relação ao seu conteúdo e organizados em unidades e subunidades de significância. Participaram 12 especialistas. Os itens mencionados para construção do roteiro originaram sete unidades

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Kombucha Multimicrobial Community under Simulated Spaceflight and Martian Conditions.

    PubMed

    Podolich, O; Zaets, I; Kukharenko, O; Orlovska, I; Reva, O; Khirunenko, L; Sosnin, M; Haidak, A; Shpylova, S; Rabbow, E; Skoryk, M; Kremenskoy, M; Demets, R; Kozyrovska, N; de Vera, J-P

    2017-05-01

    Kombucha microbial community (KMC) produces a cellulose-based biopolymer of industrial importance and a probiotic beverage. KMC-derived cellulose-based pellicle film is known as a highly adaptive microbial macrocolony-a stratified community of prokaryotes and eukaryotes. In the framework of the multipurpose international astrobiological project "BIOlogy and Mars Experiment (BIOMEX)," which aims to study the vitality of prokaryotic and eukaryotic organisms and the stability of selected biomarkers in low Earth orbit and in a Mars-like environment, a cellulose polymer structural integrity will be assessed as a biomarker and biotechnological nanomaterial. In a preflight assessment program for BIOMEX, the mineralized bacterial cellulose did not exhibit significant changes in the structure under all types of tests. KMC members that inhabit the cellulose-based pellicle exhibited a high survival rate; however, the survival capacity depended on a variety of stressors such as the vacuum of space, a Mars-like atmosphere, UVC radiation, and temperature fluctuations. The critical limiting factor for microbial survival was high-dose UV irradiation. In the tests that simulated a 1-year mission of exposure outside the International Space Station, the core populations of bacteria and yeasts survived and provided protection against UV; however, the microbial density of the populations overall was reduced, which was revealed by implementation of culture-dependent and culture-independent methods. Reduction of microbial richness was also associated with a lower accumulation of chemical elements in the cellulose-based pellicle film, produced by microbiota that survived in the post-test experiments, as compared to untreated cultures that populated the film. Key Words: BIOlogy and Mars Experiment (BIOMEX)-Kombucha multimicrobial community-Biosignature-Biofilm-Bacterial cellulose. Astrobiology 17, 459-469.

  17. Kombucha Multimicrobial Community under Simulated Spaceflight and Martian Conditions

    NASA Astrophysics Data System (ADS)

    Podolich, O.; Zaets, I.; Kukharenko, O.; Orlovska, I.; Reva, O.; Khirunenko, L.; Sosnin, M.; Haidak, A.; Shpylova, S.; Rabbow, E.; Skoryk, M.; Kremenskoy, M.; Demets, R.; Kozyrovska, N.; de Vera, J.-P.

    2017-05-01

    Kombucha microbial community (KMC) produces a cellulose-based biopolymer of industrial importance and a probiotic beverage. KMC-derived cellulose-based pellicle film is known as a highly adaptive microbial macrocolony—a stratified community of prokaryotes and eukaryotes. In the framework of the multipurpose international astrobiological project "BIOlogy and Mars Experiment (BIOMEX)," which aims to study the vitality of prokaryotic and eukaryotic organisms and the stability of selected biomarkers in low Earth orbit and in a Mars-like environment, a cellulose polymer structural integrity will be assessed as a biomarker and biotechnological nanomaterial. In a preflight assessment program for BIOMEX, the mineralized bacterial cellulose did not exhibit significant changes in the structure under all types of tests. KMC members that inhabit the cellulose-based pellicle exhibited a high survival rate; however, the survival capacity depended on a variety of stressors such as the vacuum of space, a Mars-like atmosphere, UVC radiation, and temperature fluctuations. The critical limiting factor for microbial survival was high-dose UV irradiation. In the tests that simulated a 1-year mission of exposure outside the International Space Station, the core populations of bacteria and yeasts survived and provided protection against UV; however, the microbial density of the populations overall was reduced, which was revealed by implementation of culture-dependent and culture-independent methods. Reduction of microbial richness was also associated with a lower accumulation of chemical elements in the cellulose-based pellicle film, produced by microbiota that survived in the post-test experiments, as compared to untreated cultures that populated the film.

  18. 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.

  19. Martian dust threshold measurements: Simulations under heated surface conditions

    NASA Technical Reports Server (NTRS)

    White, Bruce R.; Greeley, Ronald; Leach, Rodman N.

    1991-01-01

    Diurnal changes in solar radiation on Mars set up a cycle of cooling and heating of the planetary boundary layer, this effect strongly influences the wind field. The stratification of the air layer is stable in early morning since the ground is cooler than the air above it. When the ground is heated and becomes warmer than the air its heat is transferred to the air above it. The heated parcels of air near the surface will, in effect, increase the near surface wind speed or increase the aeolian surface stress the wind has upon the surface when compared to an unheated or cooled surface. This means that for the same wind speed at a fixed height above the surface, ground-level shear stress will be greater for the heated surface than an unheated surface. Thus, it is possible to obtain saltation threshold conditions at lower mean wind speeds when the surface is heated. Even though the mean wind speed is less when the surface is heated, the surface shear stress required to initiate particle movement remains the same in both cases. To investigate this phenomenon, low-density surface dust aeolian threshold measurements have been made in the MARSWIT wind tunnel located at NASA Ames Research Center, Moffett Field, California. The first series of tests examined threshold values of the 100 micron sand material. At 13 mb surface pressure the unheated surface had a threshold friction speed of 2.93 m/s (and approximately corresponded to a velocity of 41.4 m/s at a height of 1 meter) while the heated surface equivalent bulk Richardson number of -0.02, yielded a threshold friction speed of 2.67 m/s (and approximately corresponded to a velocity of 38.0 m/s at a height of 1 meter). This change represents an 8.8 percent decrease in threshold conditions for the heated case. The values of velocities are well within the threshold range as observed by Arvidson et al., 1983. As the surface was heated the threshold decreased. At a value of bulk Richardson number equal to -0.02 the threshold

  20. Larval survival of Anocentor nitens under simulated natural conditions.

    PubMed

    Díaz, G; de la Vega, R

    2000-01-01

    Basic knowledge about the survival of free living stages of ticks is of great importance as a practical tool to improve control methods. For Anocentor nitens there is little information on this subject. Eighty-four engorged females were incubated at 30 degrees C and 100% relative humidity. After 17 days, groups of 5,500 eggs each were collected and isolated in vials. Age zero was defined as 10 days after eclosion had begun. At this time vials with larvae were attached to 40 Sorghum halepense plants sowed in clay pots, under outdoor conditions, and separated from one another by 30 cm in order to prevent the larvae from mixing. Four hours later vials were retired and the larvae remaining in the vials were counted. The next day four plants were sampled and this survival considered as 100%. Each week for eight weeks the same sampling procedure was performed. The remaining four plants were used to determine the maximum larval survival (MLS). Four repetitions of the procedure were performed, two in March 1989 and two in September 1989.

  1. 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.

  2. 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.

  3. Tolerance of centrifuge-simulated suborbital spaceflight by medical condition.

    PubMed

    Blue, Rebecca S; Pattarini, James M; Reyes, David P; Mulcahy, Robert A; Garbino, Alejandro; Mathers, Charles H; Vardiman, Johnené L; Castleberry, Tarah L; Vanderploeg, James M

    2014-07-01

    We examined responses of volunteers with known medical disease to G forces in a centrifuge to evaluate how potential commercial spaceflight participants (SFPs) might tolerate the forces of spaceflight despite significant medical history. Volunteers were recruited based upon suitability for each of five disease categories (hypertension, cardiovascular disease, diabetes, lung disease, back or neck problems) or a control group. Subjects underwent seven centrifuge runs over 2 d. Day 1 consisted of two +G(z) runs (peak = +3.5 G(z), Run 2) and two +G(x), runs (peak = +6.0 G(x), Run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +G(x) and +G(z), peak = +6.0 G(x)/+4.0 G(z)). Data collected included blood pressure, electrocardiogram, pulse oximetry, neurovestibular exams, and post-run questionnaires regarding motion sickness, disorientation, grayout, and other symptoms. A total of 335 subjects registered for participation, of which 86 (63 men, 23 women, age 20-78 yr) participated in centrifuge trials. The most common causes for disqualification were weight and severe and uncontrolled medical or psychiatric disease. Five subjects voluntarily withdrew from the second day of testing: three for anxiety reasons, one for back strain, and one for time constraints. Maximum hemodynamic values recorded included HR of 192 bpm, systolic BP of 217 mmHg, and diastolic BP of 144 mmHg. Common subjective complaints included grayout (69%), nausea (20%), and chest discomfort (6%). Despite their medical history, no subject experienced significant adverse physiological responses to centrifuge profiles. These results suggest that most individuals with well-controlled medical conditions can withstand acceleration forces of launch and re-entry profiles of current commercial spaceflight vehicles.

  4. 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.

  5. 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....

  6. 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....

  7. 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

  8. 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.

  9. 42 CFR 485.638 - Conditions of participation: Clinical records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... properly executed informed consent forms, pertinent medical history, assessment of the health status and... 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 record...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... physician orders. and (iv) Any other documentation that will assist in post-discharge continuity of care or... correct clinical information that is available to the patient's attending physician and hospice staff. The... § 418.54(e) of this subpart. (5) Physician certification and recertification of terminal illness as...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... physician orders. and (iv) Any other documentation that will assist in post-discharge continuity of care or... correct clinical information that is available to the patient's attending physician and hospice staff. The... § 418.54(e) of this subpart. (5) Physician certification and recertification of terminal illness as...

  12. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... physician orders. and (iv) Any other documentation that will assist in post-discharge continuity of care or... correct clinical information that is available to the patient's attending physician and hospice staff. The... § 418.54(e) of this subpart. (5) Physician certification and recertification of terminal illness as...

  13. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... physician orders. and (iv) Any other documentation that will assist in post-discharge continuity of care or... information that is available to the patient's attending physician and hospice staff. The clinical record may... § 418.54(e) of this subpart. (5) Physician certification and recertification of terminal illness as...

  14. 42 CFR 418.104 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... physician orders. and (iv) Any other documentation that will assist in post-discharge continuity of care or... information that is available to the patient's attending physician and hospice staff. The clinical record may... § 418.54(e) of this subpart. (5) Physician certification and recertification of terminal illness as...

  15. Uncertainty quantification in coronary blood flow simulations: Impact of geometry, boundary conditions and blood viscosity.

    PubMed

    Sankaran, Sethuraman; Kim, Hyun Jin; Choi, Gilwoo; Taylor, Charles A

    2016-08-16

    Computational fluid dynamic methods are currently being used clinically to simulate blood flow and pressure and predict the functional significance of atherosclerotic lesions in patient-specific models of the coronary arteries extracted from noninvasive coronary computed tomography angiography (cCTA) data. One such technology, FFRCT, or noninvasive fractional flow reserve derived from CT data, has demonstrated high diagnostic accuracy as compared to invasively measured fractional flow reserve (FFR) obtained with a pressure wire inserted in the coronary arteries during diagnostic cardiac catheterization. However, uncertainties in modeling as well as measurement results in differences between these predicted and measured hemodynamic indices. Uncertainty in modeling can manifest in two forms - anatomic uncertainty resulting in error of the reconstructed 3D model and physiologic uncertainty resulting in errors in boundary conditions or blood viscosity. We present a data-driven framework for modeling these uncertainties and study their impact on blood flow simulations. The incompressible Navier-Stokes equations are used to model blood flow and an adaptive stochastic collocation method is used to model uncertainty propagation in the Navier-Stokes equations. We perform uncertainty quantification in two geometries, an idealized stenosis model and a patient specific model. We show that uncertainty in minimum lumen diameter (MLD) has the largest impact on hemodynamic simulations, followed by boundary resistance, viscosity and lesion length. We show that near the diagnostic cutoff (FFRCT=0.8), the uncertainty due to the latter three variables are lower than measurement uncertainty, while the uncertainty due to MLD is only slightly higher than measurement uncertainty. We also show that uncertainties are not additive but only slightly higher than the highest single parameter uncertainty. The method presented here can be used to output interval estimates of hemodynamic indices

  16. 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.

  17. 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.

  18. 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.

  19. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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 clinical...

  20. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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 clinical...

  1. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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 clinical...

  2. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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 clinical...

  3. 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...

  4. 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.

  5. 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.

  6. 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

  7. 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....

  8. 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....

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. Neuroendocrine Tissue Engineering in Rotating Wall Vessel Bioreactors Under Simulated Microgravity Conditions

    DTIC Science & Technology

    2001-10-25

    NEUROENDOCRINE TISSUE ENGINEERING IN ROTATING WALL VESSEL BIOREACTORS UNDER SIMULATED MICROGRAVITY CONDITIONS P.I. Lelkes1, 4, N. Akhtar2, E...Abstract-The low-shear, microgravity-simulating cell culture environment in Rotating Wall Vessel (RWV) Bioreactors RWV Bioreactors is well...microscopy. The unique culture environment of RWV Bioreactors facilitates the generation of macroscopic, functional neuroendocrine tissue-like

  14. 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

  15. Evaluation of the transferability of hydrological model parameters for simulations under changed climatic conditions

    NASA Astrophysics Data System (ADS)

    Bastola, S.; Murphy, C.; Sweeney, J.

    2011-06-01

    Conceptual hydrological models are widely used for climate change impact assessment. The implicit assumption in most such work is that the parameters estimated from observations remain valid for future climatic conditions. This paper evaluates a simple threshold based approach for testing this assumption, where a set of behavioural simulators are identified for different climatic conditions for the future simulation i.e. wet, average and dry conditions. These simulators were derived using three different data sets that are generated by sampling a block of one year of data without replacement from the observations such that they define the different climatic conditions. The simulators estimated from the wet climatic data set showed the tendency to underestimate flow when applied to dry data set and vice versa. However, the performances of the three sets of basin simulators on chronologically coherent data are identical to the simulators identified from a sufficiently long data series that contains both wet and dry climatic conditions. The results presented suggest that the issue of time invariance in the value of parameters has a minimal effect on the simulation if the change in precipitation is less than 10 % of the data used for calibration.

  16. 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…

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... If a patient is transferred to another health facility, a copy of the record or abstract is sent with... loss or unauthorized use. Written procedures govern use and removal of records and the conditions for release of information. Patient's written consent is required for release of information not authorized by...

  18. 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…

  19. 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

  20. An oracle: antituberculosis pharmacokinetics-pharmacodynamics, clinical correlation, and clinical trial simulations to predict the future.

    PubMed

    Pasipanodya, Jotam; Gumbo, Tawanda

    2011-01-01

    Antimicrobial pharmacokinetic-pharmacodynamic (PK/PD) science and clinical trial simulations have not been adequately applied to the design of doses and dose schedules of antituberculosis regimens because many researchers are skeptical about their clinical applicability. We compared findings of preclinical PK/PD studies of current first-line antituberculosis drugs to findings from several clinical publications that included microbiologic outcome and pharmacokinetic data or had a dose-scheduling design. Without exception, the antimicrobial PK/PD parameters linked to optimal effect were similar in preclinical models and in tuberculosis patients. Thus, exposure-effect relationships derived in the preclinical models can be used in the design of optimal antituberculosis doses, by incorporating population pharmacokinetics of the drugs and MIC distributions in Monte Carlo simulations. When this has been performed, doses and dose schedules of rifampin, isoniazid, pyrazinamide, and moxifloxacin with the potential to shorten antituberculosis therapy have been identified. In addition, different susceptibility breakpoints than those in current use have been identified. These steps outline a more rational approach than that of current methods for designing regimens and predicting outcome so that both new and older antituberculosis agents can shorten therapy duration.

  1. Connectionist Modeling as the Basis for Multimedia Clinical Patient Simulations with Diagnostic Capabilities.

    ERIC Educational Resources Information Center

    Bergeron, Bryan P.; And Others

    1995-01-01

    Presents a connectionist approach to modeling that relies on neural networks to control conventional simulations of multimedia clinical patient simulations. These neural networks simplify the medical expert's task of validating and maintaining patient simulations with diagnostic capabilities and serves as the basis of clinical decision support…

  2. 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,…

  3. 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…

  4. Connectionist Modeling as the Basis for Multimedia Clinical Patient Simulations with Diagnostic Capabilities.

    ERIC Educational Resources Information Center

    Bergeron, Bryan P.; And Others

    1995-01-01

    Presents a connectionist approach to modeling that relies on neural networks to control conventional simulations of multimedia clinical patient simulations. These neural networks simplify the medical expert's task of validating and maintaining patient simulations with diagnostic capabilities and serves as the basis of clinical decision support…

  5. 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

  6. The effect of high-fidelity simulation training on medical-surgical graduate nurses' perceived ability to respond to patient clinical emergencies.

    PubMed

    Gordon, Christopher James; Buckley, Tom

    2009-11-01

    Recognition of and early intervention for patients with acutely deteriorating conditions is often the responsibility of medical-surgical nurses. This study examined the effect of simulation on medical-surgical graduate nurses' perceived ability and confidence in responding to patient clinical emergencies. Fifty medical-surgical graduate students participated in high-fidelity immersive simulations. Questionnaires completed before and after simulation asked participants to rate their perceived ability and confidence. After simulation, participants reported increased confidence in their ability to perform both technical and nontechnical aspects of responding to patient clinical emergencies. Ninety-four percent of participants identified formal debriefing as the most useful aspect of the simulation experience. Medical-surgical graduate nurses' confidence and perceived technical and nontechnical skills during patient clinical emergencies are enhanced following simulation. The ability of graduates to transfer the increased confidence and perceived advanced resuscitation skills following simulation to the clinical environment needs to be investigated. Copyright 2009, SLACK Incorporated.

  7. 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.

  8. Property-process relations in simulated clinical abrasive adjusting of dental ceramics.

    PubMed

    Yin, Ling

    2012-12-01

    This paper reports on property-process correlations in simulated clinical abrasive adjusting of a wide range of dental restorative ceramics using a dental handpiece and diamond burs. The seven materials studied included four mica-containing glass ceramics, a feldspathic porcelain, a glass-infiltrated alumina, and a yttria-stabilized tetragonal zirconia. The abrasive adjusting process was conducted under simulated clinical conditions using diamond burs and a clinical dental handpiece. An attempt was made to establish correlations between process characteristics in terms of removal rate, chipping damage, and surface finish and material mechanical properties of hardness, fracture toughness and Young's modulus. The results show that the removal rate is mainly a function of hardness, which decreases nonlinearly with hardness. No correlations were noted between the removal rates and the complex relations of hardness, Young's modulus and fracture toughness. Surface roughness was primarily a linear function of diamond grit size and was relatively independent of materials. Chipping damage in terms of the average chipping width decreased with fracture toughness except for glass-infiltrated alumina. It also had higher linear correlations with critical strain energy release rates (R²=0.66) and brittleness (R²=0.62) and a lower linear correlation with indices of brittleness (R²=0.32). Implications of these results can provide guidance for the microstructural design of dental ceramics, optimize performance, and guide the proper selection of technical parameters in clinical abrasive adjusting conducted by dental practitioners.

  9. Growth conditions influence melanization of Brazilian clinical Sporothrix schenckii isolates

    PubMed Central

    Almeida-Paes, Rodrigo; Frases, Susana; Monteiro, Paulo Cezar Fialho; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria; Nosanchuk, Joshua D.

    2009-01-01

    Sporothrix schenckii is known to produce DHN melanin on both conidial and yeast cells, however little information is available regarding the factors inducing fungal melanization. We evaluated whether culture conditions influenced melanization of 25 Brazilian S. schenckii strains and one control strain (ATCC 10212). Tested conditions included different media, pH, temperature, incubation time, glucose concentrations, and presence or absence of tricyclazole or L-DOPA. Melanization was reduced on Sabouraud compared to defined chemical medium. The majority of strains produced small amounts of melanin at 37°C and none melanized at basic pH. Increased glucose concentrations did not inhibit melanization, rather increasing glucose enhanced pigment production in 27% of strains. Melanin synthesis was also enhanced by the addition of L-DOPA and its addition to medium with tricyclazole, an inhibitor of melanin synthesis, resulted in fungal melanization, including hyphal melanin production. Our results suggest that different S. schenckii strains have distinct control of melanization and that this fungus can use phenolic compounds to enhance melanization in vitro. PMID:19328867

  10. 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)

  11. 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)

  12. 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.

  13. 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.

  14. Nursing students' clinical judgment regarding rapid response: the influence of a clinical simulation education intervention.

    PubMed

    Lindsey, Pamela L; Jenkins, Sheryl

    2013-01-01

    The aim of this study was to examine the impact of a novel educational intervention on student nurses' clinical judgment regarding the management of patients experiencing rapid clinical deterioration. A randomized sample of baccalaureate nursing students enrolled in the final semester of their program at a midwestern public university participated. All students (N = 79) were pretested; the control group (n = 39) was posttested after receiving traditional code blue and rapid response education. The intervention group (n = 40) was posttested after receiving a novel education intervention. An independent t-test revealed that nursing students who received the innovative education intervention had significantly higher posttest scores (M = 90.91, standard deviation [SD] = 8.73) than did the nursing students who had not received the intervention (M = 64.80, SD = 19.69), t(77) = 7.65, p <.001). The findings demonstrate that clinical simulation is effective in improving students' knowledge and clinical judgment, specifically concerning rapid response systems. © 2013 Wiley Periodicals, Inc.

  15. 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.

  16. Web-conferenced simulation sessions: a satisfaction survey of clinical simulation encounters via remote supervision.

    PubMed

    Hayden, Emily M; Navedo, Deborah D; Gordon, James A

    2012-09-01

    A critical barrier to expanding simulation-based instruction in medicine is the availability of clinical instructors. Allowing instructors to remotely observe and debrief simulation sessions may make simulation-based instruction more convenient, thus expanding the pool of instructors available. This study compared the impact of simulation sessions facilitated by in-person (IP) faculty versus those supervised remotely using Web-conferencing software (WebEx(®), Cisco [ www.webex.com/ ]). A convenience sample of preclinical medical students volunteered to "care for" patients in a simulation laboratory. Students received either standard IP or Web-conferenced (WC) instruction. WC sessions were facilitated by off-site instructors. A satisfaction survey (5-point Likert scale, where 1=strongly disagree and 5=strongly agree) was completed immediately following the sessions. Forty-four surveys were analyzed (WC n=25, IP n=19). In response to the question "Was the communication between faculty and students a barrier to understanding the case?," the average student responses were 2.8 (95% confidence interval [CI] 2.4-3.2) for WC and 4.5 (95% CI 4.0-5.0) for IP (p<0.0001). In response to the question "Would you participate again in such a session?," the average student responses were 4.2 (95% CI 4.0-4.5) for WC and 4.9 (95% CI 4.6-5.2) for IP (p=0.0003). Both groups agreed that they acquired new skills (4.2 for WC, 4.5 for IP; p=0.39) and new knowledge (4.6 for WC, 4.7 for IP; p=0.41). Telecommunication can successfully enhance access to simulation-based instruction. In this study, a Web interface downgraded the quality of student-faculty communication. Future investigation is needed to better understand the impact of such an effect on the learning process and to reduce barriers that impede implementation of technology-facilitated supervision.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. [The most common conditions in a neurology specialty clinic].

    PubMed

    Trevisol-Bittencourt, P C; Ferreira, M A; Marasciulo, A C; Collares, C F

    2001-06-01

    To present the most frequent diagnosis among patients referred for neurological evaluation to estimate their labour capacities at the unit of National Institute of Social Security (INSS), Florianópolis-SC, southern Brazil. Review of all medical records of 108 patients evaluated between October 97 and May 98. The sample was submitted to judicious medico-legal assessment to define their final diagnosis. Neurological evaluation disclosed as the commonest disorders, in decreasing order of frequency: epilepsy, rheumatic diseases, psychiatric illnesses, neurological disorders related to chronic alcoholism, head trauma syndrome and cerebrovascular diseases. Neurological disorders may be responsible for important disability among workers in our society. However, the potential for social rehabilitation, often underestimated, must be considered. Moreover, diverse non-neurological conditions used to be sent for neurological evaluation.

  3. 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.

  4. 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

  5. Effects of an Experiential Learning Simulation Design on Clinical Nursing Judgment Development.

    PubMed

    Chmil, Joyce Victor; Turk, Melanie; Adamson, Katie; Larew, Charles

    2015-01-01

    Simulation design should be theory based and its effect on outcomes evaluated. This study (1) applied a model of experiential learning to design a simulation experience, (2) examined how this design affected clinical nursing judgment development, and (3) described the relationship between clinical nursing judgment development and student performance when using the experiential learning design. Findings suggest that using an experiential learning simulation design results in more highly developed nursing judgment and competency in simulation performance.

  6. 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.

  7. 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.

  8. 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.

  9. Clinical and statistical correlation of various lumbar pathological conditions.

    PubMed

    Johnson, J Michael; Mahfouz, Mohamed; Battaglia, Nicholas V; Sharma, Adrija; Cheng, Joseph S; Komistek, Richard D

    2013-02-22

    Current clinical evaluations often rely on static anatomic imaging modalities for diagnosis of mechanical low back pain, which provide anatomic snapshots and a surrogate analysis of a functional disease. Three dimensional in vivo motion is available with the use of digital fluoroscopy, which was used to capture kinematic data of the lumbar spine in order to identify coefficients of motion that may assist the physician in differentiating patient pathology. Forty patients distributed among 4 classes of lumbar degeneration, from healthy to degenerative, underwent CT, MRI, and digital x-ray fluoroscopy. Each patient underwent diagnosis by a neurosurgeon. Fluoroscopy was taken as the patient performed lateral bending (LB), axial rotation (AR) and flexion-extension (FE). Patient specific models were registered with the fluoroscopy images to obtain in vivo kinematic data. Motion coefficients, C(LB), C(AR), C(FE), were calculated as the ratio of in-plane motion to total out-of-plane motion. Range of motion (ROM) was calculated about the axis of motion for each exercise. Inter- and Intra- group statistics were examined for each coefficient and a flexible Bayesian classifier was used to differentiate patients with degeneration. The motion coefficients C(LB) and C(FE) were significantly different (p<0.05) in 4 of 6 group comparisons. In plane motion, ROM(LB), was significantly different in only 1 of 6 group comparisons. The classifier achieved 95% sensitivity and specificity using (C(FE), C(LB), ROM(LB)) as input features, and 40% specificity and 80% sensitivity using ROM variables. The new coefficients were better correlated with patient pathology than ROM measures. The coefficients suggest a relationship between pathology and measured motion which has not been reported previously. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. 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.

  11. 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...

  12. 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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 this...

  14. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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 this...

  15. Shifted periodic boundary conditions for large-eddy simulation of wind farms

    NASA Astrophysics Data System (ADS)

    Munters, Wim; Meneveau, Charles; Meyers, Johan

    2015-11-01

    In wall-bounded turbulent flow simulations, periodic boundary conditions combined with insufficiently long domains lead to persistent spanwise locking of large-scale turbulent structures. In the context of wind-farm large-eddy simulations, this effect induces artificial spanwise inhomogeneities in the time-averaged local wind conditions as seen by the wind turbines, leading to spurious differences in power prediction between otherwise equivalent columns of wind turbines in a wind farm (a column is defined here as a set of turbines parallel to the mean flow direction). We propose a shifted periodic boundary condition that eliminates this effect without the need for excessive streamwise domain lengths. Instead of straightforwardly reintroducing the velocity from the outlet plane back at the inlet, as in classic periodic boundary conditions, this plane is first shifted in the spanwise direction by a predefined and constant distance. The method is tested based on a set of direct numerical simulations of a turbulent channel flow, and large-eddy simulations of a high Reynolds number rough-wall half-channel flow. Finally, we apply the method in a precursor simulation, generating inlet conditions for a spatially developing wind-farm boundary layer. WM and JM are supported by the ERC (ActiveWindFarms, grant no: 306471). CM acknowledges support by the NSF (grant IIA-1243482, the WINDINSPIRE project).

  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. 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.

  18. 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.

  19. Gastric Water Emptying under Fed State Clinical Trial Conditions Is as Fast as under Fasted Conditions.

    PubMed

    Grimm, Michael; Scholz, Elisabeth; Koziolek, Mirko; Kühn, Jens-Peter; Weitschies, Werner

    2017-10-05

    The Magenstrasse (stomach road) describes the fast emptying of ingested liquids from the postprandial stomach. The occurrence of the Magenstrasse has great importance for drugs administered together with food as it represents a shortcut through the fed stomach and allows rapid onset of plasma levels. In this study, we investigated the effect of different meals and their texture and fat content on the occurrence of the Magenstrasse. Since the administration of water is common 60 min after drug intake in clinical trials, we also investigated the effect of time point of water administration on the Magenstrasse by a second water administration. The texture of solid meals and a higher amount of solid food components turned out to favor the presence of the Magenstrasse. On the other hand, the effect of fat content of the meals was negligible. Additionally, the gastric emptying of water was comparable between the first and the second (60 min later) fluid administration, which could lead to an entrainment of drug substance. So far, the Magenstrasse is proven for water; an investigation of other liquid vehicles might be interesting for further mechanistic understanding and utilization. It turned out that the phenomenon of the Magenstrasse can also occur at later time points in clinical studies and may have great impact on the pharmacokinetic profiles obtained in these studies.

  20. 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.

  1. Conditioning geostatistical simulations of a heterogeneous paleo-fluvial bedrock aquifer using lithologs and pumping tests

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    Geostatistical simulations are used to construct heterogeneous aquifer models. Optimally, such simulations should be conditioned with both lithologic and hydraulic data. We introduce an approach to condition lithologic geostatistical simulations of a paleo-fluvial bedrock aquifer consisting of relatively high permeable sandstone channels embedded in relatively low permeable mudstone using hydraulic data. The hydraulic data consist of two-hour single well pumping tests extracted from the public water well database for a 250-km2 watershed in Alberta, Canada. First, lithologic models of the entire watershed are simulated and conditioned with hard lithological data using transition probability - Markov chain geostatistics (TPROGS). Then, a segment of the simulation around a pumping well is 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 are then adjusted to minimize the difference between simulated and actual pumping test data using the parameter estimation program PEST. If the simulated pumping test data do not adequately match the measured data, the lithologic model is updated by locally deforming the lithology distribution using the probability perturbation method 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 well that has pumping test data. The method creates a local groundwater model that honors both the lithologic model and pumping test data and provides estimates of hydraulic conductivity and specific storage. Eventually, the simulations will be integrated into a watershed-scale groundwater model.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Comparison of virtual patient simulation with mannequin-based simulation for improving clinical performances in assessing and managing clinical deterioration: randomized controlled trial.

    PubMed

    Liaw, Sok Ying; Chan, Sally Wai-Chi; Chen, Fun-Gee; Hooi, Shing Chuan; Siau, Chiang

    2014-09-17

    Virtual patient simulation has grown substantially in health care education. A virtual patient simulation was developed as a refresher training course to reinforce nursing clinical performance in assessing and managing deteriorating patients. The objective of this study was to describe the development of the virtual patient simulation and evaluate its efficacy, by comparing with a conventional mannequin-based simulation, for improving the nursing students' performances in assessing and managing patients with clinical deterioration. A randomized controlled study was conducted with 57 third-year nursing students who were recruited through email. After a baseline evaluation of all participants' clinical performance in a simulated environment, the experimental group received a 2-hour fully automated virtual patient simulation while the control group received 2-hour facilitator-led mannequin-based simulation training. All participants were then re-tested one day (first posttest) and 2.5 months (second posttest) after the intervention. The participants from the experimental group completed a survey to evaluate their learning experiences with the newly developed virtual patient simulation. Compared to their baseline scores, both experimental and control groups demonstrated significant improvements (P<.001) in first and second post-test scores. While the experimental group had significantly lower (P<.05) second post-test scores compared with the first post-test scores, no significant difference (P=.94) was found between these two scores for the control group. The scores between groups did not differ significantly over time (P=.17). The virtual patient simulation was rated positively. A virtual patient simulation for a refreshing training course on assessing and managing clinical deterioration was developed. Although the randomized controlled study did not show that the virtual patient simulation was superior to mannequin-based simulation, both simulations have demonstrated

  7. 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.

  8. Evaluation of Rankine cycle air conditioning system hardware by computer simulation

    NASA Technical Reports Server (NTRS)

    Healey, H. M.; Clark, D.

    1978-01-01

    A computer program for simulating the performance of a variety of solar powered Rankine cycle air conditioning system components (RCACS) has been developed. The computer program models actual equipment by developing performance maps from manufacturers data and is capable of simulating off-design operation of the RCACS components. The program designed to be a subroutine of the Marshall Space Flight Center (MSFC) Solar Energy System Analysis Computer Program 'SOLRAD', is a complete package suitable for use by an occasional computer user in developing performance maps of heating, ventilation and air conditioning components.

  9. Ab initio Molecular Dynamics Simulations of Water Under Static and Shock Compressed Conditions

    SciTech Connect

    Goldman, N; Fried, L E; Mundy, C J; Kuo, I W; Curioni, A; Reed, E

    2007-07-25

    We report herein a series of ab initio simulations of water under both static and shocked conditions. We have calculated the coherent x-ray scattering intensity of several phases of water under high pressure, using ab initio Density Functional Theory (DFT). We provide new atomic scattering form factors for water at extreme conditions, which take into account frequently neglected changes in ionic charge and electron delocalization. We have also simulated liquid water undergoing shock loading of velocities from 5-11 km/s using the Multi-Scale Shock Technique (MSST). We show that Density Functional Theory (DFT) molecular dynamics results compare extremely well to experiments on the water shock Hugoniot.

  10. 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

  11. A boundary condition with adjustable slip length for lattice Boltzmann simulations

    NASA Astrophysics Data System (ADS)

    Khalid Ahmed, Nayaz; Hecht, Martin

    2009-09-01

    A velocity boundary condition for the lattice Boltzmann simulation technique has been proposed recently by Hecht and Harting (2008 arXiv:0811.4593). This boundary condition is independent of the relaxation process during collision and contains no artificial slip. In this work, this boundary condition is extended to simulate slip flows. The extended boundary condition has been tested and it is found that the slip length is independent of the shear rate and the density, and proportional to the BGK relaxation time. The method is used to study slip in Poiseuille flow and in linear shear flow. Patterned walls with stripes of different slip parameters are also studied, and an anisotropy of the slip length in accordance with the surface pattern is found. The angle dependence of the simulation results perfectly agrees with theoretical expectations. The results confirm that the proposed boundary conditions can be used for simulating slip flows in microfluidics using the single-relaxation-time lattice Boltzmann technique, without any numerical slip, giving an accuracy of second order.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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. Project HOPE—The People-to-People Health Foundation, Inc.

  3. 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.

  4. 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.

  5. 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.

  6. Human Estimation of Slope, Distance, and Height of Terrain in Simulated Lunar Conditions

    DTIC Science & Technology

    2009-02-01

    the illumination direction influenced the judged 3D shape [56]. The lunar regolith, however, possesses a unique BDRF, known as Non-Lambertian...Human Estimation of Slope, Distance, and Height of Terrain in Simulated Lunar Conditions by Christopher Oravetz B.S., Aeronautical... Lunar Conditions 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  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. 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.

  14. 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. Copyright © 2013 John Wiley & Sons, Ltd.

  15. Testing computer-based simulation to enhance clinical judgment skills in senior nursing students.

    PubMed

    Weatherspoon, Deborah L; Wyatt, Tami H

    2012-12-01

    Expert clinical judgment is the culmination of knowledge and experiential learning that includes reflections on immediate problems and past experience. In nursing education, experiential learning is augmented through the use of simulated clinical experiences provided in simulation laboratories. Various simulations have been reported; however, few studies target the effectiveness of experiential learning using a computer-based simulation available to the individual user. An educational intervention based on Kolb's Experiential Learning Theory (ELT) is examined in this pilot study, to determine the feasibility of conducting a future larger-scale research project on the effectiveness of ELT in enhancing development of clinical judgment skills. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. 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.

  17. The Easytube for airway management: a systematic review of clinical and simulation studies.

    PubMed

    Sanfilippo, Filippo; Chiarenza, Federica; Maybauer, Dirk M; Maybauer, Marc O

    2016-06-01

    Endotracheal intubation is considered the criterion-standard technique for securing the airway. Supraglottic airway devices (SADs) represent a major advance in airway management and are recommended by the guidelines in difficult situations such as Advanced Life Support and "cannot ventilate-cannot intubate" scenarios. The Easytube (EzT) is an SAD introduced a decade ago but not included yet in the above guidelines. Systematic review of MEDLINE and EMBASE according to PRISMA guidelines available up to January 12, 2016. We collected experimental and clinical evidence regarding EzT positioning performed by medial students, anesthesiologists, paramedics, or nurses. Manikins, cadavers, or patients. EzT positioning in both clinical and simulation studies, both under standard and under difficult scenarios. Time to insertion and time to ventilation, success rate and operator's assessment of the device, change in ventilatory parameters, and major complications. Fifteen manuscripts were found: 6 prospective clinical studies and 9 conducted under experimental conditions (7 with a simulator and 2 on cadavers). The EzT inserted by both inexperienced and experienced personnel in most studies had high success rate, and it showed excellent results also during simulated cardiopulmonary resuscitation and in difficult airway scenarios. The EzT had better ventilatory parameters as compared with the Combitube and showed great airway sealing capacity, comparable to the Combitube and to the laryngeal mask airway and superior to other SADs. EzT allowed the insertion of large nasogastric tubes and has only mild adverse effects like other SADs. No major complications were described. The EzT appears to be a safe and a good alternative to established SADs. It may be considered among SADs by future guidelines on Advanced Life Support and "cannot ventilate-cannot intubate" scenarios. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Cognitive control level of action for analyzing verbal reports in educative clinical simulation situations.

    PubMed

    Morineau, Thierry; Meineri, Sebastien; Chapelain, Pascal

    2017-03-01

    Several methods and theoretical frameworks have been proposed for efficient debriefing after clinical simulation sessions. In these studies, however, the cognitive processes underlying the debriefing stage are not directly addressed. Cognitive control constitutes a conceptual link between behavior and reflection on behavior to apprehend debriefing cognitively. Our goal was to analyze cognitive control from verbal reports using the Skill-Rule-Knowledge model. This model considers different cognitive control levels from skill-based to rule-based and knowledge-based control. An experiment was conducted with teams of nursing students who were confronted with emergency scenarios during high-fidelity simulation sessions. Participants' descriptions of their actions were asked in the course of the simulation scenarios or during the debriefing stage. 52 nursing students working in 26 pairs participated in this study. Participants were divided into two groups: an "in situ" group in which they had to describe their actions at different moments of a deteriorating patient scenario, and a "debriefing" group, in which, at the same moments, they had to describe their actions displayed on a video recording. In addition to a cognitive analysis, the teams' clinical performance was measured. The cognitive control level in the debriefing group was generally higher than in the in situ group. Good team performance was associated with a high level of cognitive control after a patient's significant state deterioration. These findings are in conformity with the "Skill-Rule-Knowledge" model. The debriefing stage allows a deeper reflection on action compared with the in situ condition. If an abnormal event occurs as an adverse event, then participants' mental processes tend to migrate towards knowledge-based control. This migration particularly concerns students with the best clinical performance. Thus, this cognitive framework can help to strengthen the analysis of verbal reports. Copyright

  19. The impact of training and working conditions on junior doctors’ intention to leave clinical practice

    PubMed Central

    2014-01-01

    Background The shortage of physicians is an evolving problem throughout the world. In this study we aimed to identify to what extent junior doctors’ training and working conditions determine their intention to leave clinical practice after residency training. Methods A prospective cohort study was conducted in 557 junior doctors undergoing residency training in German hospitals. Self-reported specialty training conditions, working conditions and intention to leave clinical practice were measured over three time points. Scales covering training conditions were assessed by structured residency training, professional support, and dealing with lack of knowledge; working conditions were evaluated by work overload, job autonomy and social support, based on the Demand–Control–Support model. Multivariate ordinal logistic regression analyses with random intercept for longitudinal data were applied to determine the odds ratio of having a higher level of intention to leave clinical practice. Results In the models that considered training and working conditions separately to predict intention to leave clinical practice we found significant baseline effects and change effects. After modelling training and working conditions simultaneously, we found evidence that the change effect of job autonomy (OR 0.77, p = .005) was associated with intention to leave clinical practice, whereas for the training conditions, only the baseline effects of structured residency training (OR 0.74, p = .017) and dealing with lack of knowledge (OR 0.74, p = .026) predicted intention to leave clinical practice. Conclusions Junior doctors undergoing specialty training experience high workload in hospital practice and intense requirements in terms of specialty training. Our study indicates that simultaneously improving working conditions over time and establishing a high standard of specialty training conditions may prevent junior doctors from considering leaving clinical practice after

  20. 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.

  1. 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.

  2. Effect of Simulated Gastrointestinal Conditions on Biofilm Formation by Salmonella 1,4,[5],12:i:-

    PubMed Central

    Seixas, R.; Gabriel, M.; Machado, J.; Tavares, L.; Bernardo, F.; Oliveira, M.

    2014-01-01

    Salmonella Typhimurium 1,4,[5],12:i:- is a major serovar responsible for human salmonellosis whose biofilm-forming ability, influenced by environmental conditions like those found in the gastrointestinal tract, is one of the main contributing factors to its ability to persist in the host and thus one of the main causes of chronic relapsing infections. Most studies to evaluate biofilm formation are performed in microtiter assays using standard media. However, no reports are available on the ability of this serovar to produce biofilm under in vitro simulated gastrointestinal conditions which better correlate with the environment found in the gastrointestinal tract. To address this, a modified biofilm assay simulating intestinal fluid was conceived to assess the biofilm formation of 133 Salmonella Typhimurium 1,4,[5],12:i:- isolates with and without agitation and at three different time points (24 h, 48 h, and 72 h). The results were then compared to the existing microtiter method using conventional biofilm growth medium (Mueller Hinton Broth). Statistical analysis revealed significant differences in the results obtained between the three protocols used. The simulated human intestinal environment impaired biofilm production demonstrating that conditions like pH, agitation or the presence of enzymes can influence biofilm production. Therefore, results from in vitro simulation of in vivo conditions may contribute to unravelling factors relating to biofilm formation and persistence in the context of the human host. PMID:25093197

  3. 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...

  4. 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.

  5. 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.

  6. 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...

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

    SciTech Connect

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

    2016-07-11

    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. In conclusion, the simulated temperature field is validated by the good agreement to the experimental measurements.

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

    DOE PAGES

    Chen, Gaoqiang; Feng, Zhili; Zhu, Yucan; ...

    2016-07-11

    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, themore » 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. In conclusion, the simulated temperature field is validated by the good agreement to the experimental measurements.« less

  9. 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…

  10. 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…

  11. 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.…

  12. Penetration of n-hexadecane and water into wood under conditions simulating catastrophic floods

    Treesearch

    Ganna Baglayeva; Wayne S. Seames; Charles R. Frihart; Jane O' Dell; Evguenii I. Kozliak

    2017-01-01

    To simulate fuel oil spills occurring during catastrophic floods, short-term absorption of two chemicals, n-hexadecane (representative of semivolatile organic compounds in fuel oil) and water, into southern yellow pine was gravimetrically monitored as a function of time at ambient conditions. Different scenarios were run on the basis of (1) the...

  13. 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.…

  14. 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.

  15. A collaborative project to apply and evaluate the clinical judgment model through simulation.

    PubMed

    Dillard, Nancy; Sideras, Stephanie; Ryan, Marilyn; Carlton, Kay Hodson; Lasater, Kathie; Siktberg, Linda

    2009-01-01

    As use of simulations increases in nursing education, nurse educators are challenged to evaluate students' clinical judgment skills. The purpose of this article is to describe faculty development in the use of the Lasater Clinical Judgment Rubric (LCJR); faculty application of LCJR in evaluating students' clinical judgment skills during a simulation scenario; and faculty and students' perception transference from the simulation to the clinical setting.Tanner's Clinical Judgment Model was used in an assigned adult health simulation. Quantitative and qualitative data were collected from faculty and student evaluations and students' reflective statements. Findings support the importance of simulation's contribution to clinical judgment development. However, more work remains to improve the integration of clinical judgment and use of a conceptual framework and evidence-based rubric. For long-term change, both faculty and students need ongoing practice and encouragement in applying the clinical judgment framework to clinical and simulation experiences. For application of the model, a recommendation is to incorporate the clinical judgment language into course syllabi, course assignments, and evaluations.

  16. Monte Carlo Simulations of the Dissolution of Borosilicate Glasses in Near-Equilibrium Conditions

    SciTech Connect

    Kerisit, Sebastien; Pierce, Eric M

    2012-01-01

    Monte Carlo simulations were performed to investigate the mechanisms of glass dissolution as equilibrium conditions are approached in both static and flow-through conditions. The glasses studied are borosilicate glasses in the compositional range (80 x)% SiO2 (10 + x / 2)% B2O3 (10 + x / 2)% Na2O, where 5 < x < 30%. In static conditions, dissolution/condensation reactions lead to the formation, for all compositions studied, of a blocking layer composed of polymerized Si sites with principally 4 connections to nearest Si sites. This layer forms atop the altered glass layer and shows similar composition and density for all glass compositions considered. In flow-through conditions, three main dissolution regimes are observed: at high flow rates, the dissolving glass exhibits a thin alteration layer and congruent dissolution; at low flow rates, a blocking layer is formed as in static conditions but the simulations show that water can occasionally break through the blocking layer causing the corrosion process to resume; and, at intermediate flow rates, the glasses dissolve incongruently with an increasingly deepening altered layer. The simulation results suggest that, in geological disposal environments, small perturbations or slow flows could be enough to prevent the formation of a permanent blocking layer. Finally, a comparison between predictions of the linear rate law and the Monte Carlo simulation results indicates that, in flow-through conditions, the linear rate law is applicable at high flow rates and deviations from the linear rate law occur under low flow rates (e.g., at near-saturated conditions with respect to amorphous silica). This effect is associated with the complex dynamics of Si dissolution/condensation processes at the glass water interface.

  17. Optical ensemble analysis of intraocular lens performance through a simulated clinical trial with ZEMAX.

    PubMed

    Zhao, Huawei

    2009-01-01

    A ZEMAX model was constructed to simulate a clinical trial of intraocular lenses (IOLs) based on a clinically oriented Monte Carlo ensemble analysis using postoperative ocular parameters. The purpose of this model is to test the feasibility of streamlining and optimizing both the design process and the clinical testing of IOLs. This optical ensemble analysis (OEA) is also validated. Simulated pseudophakic eyes were generated by using the tolerancing and programming features of ZEMAX optical design software. OEA methodology was verified by demonstrating that the results of clinical performance simulations were consistent with previously published clinical performance data using the same types of IOLs. From these results we conclude that the OEA method can objectively simulate the potential clinical trial performance of IOLs.

  18. Self-Reflection of Video-Recorded High-Fidelity Simulations and Development of Clinical Judgment.

    PubMed

    Bussard, Michelle E

    2016-09-01

    Nurse educators are increasingly using high-fidelity simulators to improve prelicensure nursing students' ability to develop clinical judgment. Traditionally, oral debriefing sessions have immediately followed the simulation scenarios as a method for students to connect theory to practice and therefore develop clinical judgment. Recently, video recording of the simulation scenarios is being incorporated. This qualitative, interpretive description study was conducted to identify whether self-reflection on video-recorded high-fidelity simulation (HFS) scenarios helped prelicensure nursing students to develop clinical judgment. Tanner's clinical judgment model was the framework for this study. Four themes emerged from this study: Confidence, Communication, Decision Making, and Change in Clinical Practice. This study indicated that self-reflection of video-recorded HFS scenarios is beneficial for prelicensure nursing students to develop clinical judgment. [J Nurs Educ. 2016;55(9):522-527.]. Copyright 2016, SLACK Incorporated.

  19. A method of generating initial conditions for cosmological N-body simulations

    SciTech Connect

    Joyce, M.; Levesque, D.; Marcos, B.

    2005-11-15

    We investigate the possibility of generating initial conditions for cosmological N-body simulations by simulating a system whose correlations at thermal equilibrium approximate well those of cosmological density perturbations. The system is an appropriately modified version of the standard 'one component plasma' (OCP). We show first how a well-known semianalytic method can be used to determine the potential required to produce the desired correlations, and then verify our results for some cosmological type spectra with simulations of the full molecular dynamics. The advantage of the method, compared to the standard one, is that it gives by construction an accurate representation of both the real and reciprocal space correlation properties of the theoretical model. Furthermore the distributions are also statistically homogeneous and isotropic. We discuss briefly the modifications needed to implement the method to produce configurations appropriate for large N-body simulations in cosmology, and also the generation of initial velocities in this context.

  20. 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.

  1. 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.

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

    PubMed

    Chaballout, Basil; Molloy, Margory; Vaughn, Jacqueline; Brisson Iii, Raymond; Shaw, Ryan

    2016-03-07

    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. 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. 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. 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. 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.

  3. 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

  4. 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.

  5. Monte Carlo Simulations of the Dissolution of Borosilicate Glasses in Near-Equilibrium Conditions

    SciTech Connect

    Kerisit, Sebastien N.; Pierce, Eric M.

    2012-05-15

    Monte Carlo simulations were performed to investigate the mechanisms of glass dissolution as equilibrium conditions are approached in both static and flow-through conditions. The glasses studied are borosilicate glasses in the compositional range (80-x)% SiO2 (10+x/2)% B2O3 (10+x/2)% Na2O, where 5 < x < 30%. In static conditions, dissolution/condensation reactions lead to the formation, for all compositions studied, of a blocking layer composed of polymerized Si sites with principally 4 connections to nearest Si sites. This layer forms atop the altered glass layer and shows similar composition and density for all glass compositions considered. In flow-through conditions, three main dissolution regimes are observed: at high flow rates, the dissolving glass exhibits a thin alteration layer and congruent dissolution; at low flow rates, a blocking layer is formed as in static conditions but the simulations show that water can occasionally break through the blocking layer causing the corrosion process to resume; and, at intermediate flow rates, the glasses dissolve incongruently with an increasingly deepening altered layer. The simulation results suggest that, in geological disposal environments, small perturbations or slow flows could be enough to prevent the formation of a permanent blocking layer.

  6. 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.

  7. 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.

  8. 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.

  9. Numerical simulation of pressure fluctuation in 1000MW Francis turbine under small opening condition

    NASA Astrophysics Data System (ADS)

    Gong, R. Z.; Wang, H. G.; Yao, Y.; Shu, L. F.; Huang, Y. J.

    2012-11-01

    In order to study the cause of abnormal vibration in large Francis turbine under small opening condition, CFD method was adopted to analyze the flow filed and pressure fluctuation. Numerical simulation was performed on the commercial CFD code Ansys FLUENT 12, using DES method. After an effective validation of the computation result, the flow behaviour of internal flow field under small opening condition is analyzed. Pressure fluctuation in different working mode is obtained by unsteady CFD simulation, and results is compared to study its change. Radial force fluctuation is also analyzed. The result shows that the unstable flow under small opening condition leads to an increase of turbine instability in reverse pump mode, and is one possible reason of the abnormal oscillation.

  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. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. What matters most? Students' rankings of simulation components that contribute to clinical judgment.

    PubMed

    Kelly, Michelle A; Hager, Paul; Gallagher, Robyn

    2014-02-01

    As the pedagogy of health care simulation matures, the level of guidance provided and types of simulation components included increasingly vary. To prepare students for professional practice, one university embedded Tanner's model of clinical judgment within the nursing curricula and integrated simulations. There was interest in seeking students' opinions of "what matters most" in the design and delivery of simulations, which may vary from the academic's viewpoint. Senior undergraduate nursing students (N = 150) from three types of study programs rated 11 simulation components in relation to clinical judgment. The three student groups rated all components above 2.9 on a 5-point Likert scale, with some variation across groups for component rankings. The highest ranking components for applying clinical judgment were facilitated debriefing, postsimulation reflection, and guidance by the academic. The lowest ranked components were patient case notes and briefing and orientation to the simulation area. Age and previous nursing experience did not influence the study variables. Copyright 2014, SLACK Incorporated.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. The Lacuna Open Boundary Condition For Electromagnetics and Particle-in-Cell Simulation of Plasmas

    NASA Astrophysics Data System (ADS)

    Wolf, Eric; Greenwood, Andrew; Christlieb, Andrew

    2012-10-01

    In many typical situations in computational electromagnetics (CEM), a finite computational domain must be truncated with a boundary condition (called an absorbing boundary condition or open boundary condition, among other names) that allows outgoing waves to exit with minimal spurious reflection. One highly successful such boundary condition is the perfectly matched layer (PML), introduced by Berenger in 1994 and refined by others in subsequent years, which provides for minimal reflection at an acceptable computational cost. One difficulty in the use of PML is the need to tune several parameters to suit any given problem. Another open boundary condition is the lacuna open boundary condition (LOBC), pioneered by Ryaben'kii, Tsynkov and others, which makes use of the presence of lacunae, still regions where all waves have left and will no longer return, in solutions to wave equations in odd dimensions with compactly supported sources. We examine the use of the LOBC as a means of truncating Finite Difference Time Domain (FDTD) meshes in electromagnetic simulations and particle-in-cell simulations of plasmas, and compare to PML in terms of spurious reflections, computational cost and ease of use.

  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. 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. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  10. 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.

  11. 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

  12. Simulated Gastrointestinal pH Condition Improves Antioxidant Properties of Wheat and Rice Flours

    PubMed Central

    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. PMID:22837707

  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. A comparison of residual smear layer and erosion following different endodontic irrigation protocols tested under clinical and laboratory conditions.

    PubMed

    Cehreli, Zafer C; Uyanik, M Ozgur; Nagas, Emre; Tuncel, Behram; Er, Nuray; Comert, Fugen Dagli

    2013-09-01

    To compare the smear layer removal efficacy and erosive effects of different irrigation protocols under clinical and laboratory conditions. Mandibular third molars (n = 32) of 30-45 year-old patients were instrumented with rotary files and were randomly assigned to one of the following groups for final irrigation: (1) 5.25% NaOCl; (2) 17% EDTA; and (3) BioPure MTAD. Thereafter, the teeth were immediately extracted and processed for micromorphological investigation. In vitro specimen pairs were prepared by repeating the clinical experiments on freshly-extracted mandibular third molars. To compare open and closed systems, laboratory experiments were repeated on 32 additional teeth with enlarged apical foramen. The cleanliness of the root canals and the extent of erosion were assessed by environmental scanning electron microscopy. Specimens prepared under clinical and laboratory conditions had similar cleanliness and erosion scores (p > 0.05). Under both conditions, the tested solutions were more effective in removing the smear layer in the coronal and middle regions than in the apical one. Comparison of closed and open systems showed similar levels of cleanliness and erosion in all regions (p > 0.05), with the exception of 17% EDTA showing significantly higher levels of cleanliness and erosion in the apical third of open-end specimens. Based on clinical correlates of in vitro root canal cleanliness and erosion, laboratory testing of root canal irrigants on extracted teeth with closed apices can serve as a reliable method to simulate the clinical condition. EDTA was the most effective final irrigation solution in removing the smear layer at the expense of yielding the greatest erosive effect.

  15. On the Generation of Turbulent Inflow Conditions for Boundary Layer Simulations

    NASA Technical Reports Server (NTRS)

    Lund, T. S.; Wu, X.; Squires, K. D.

    1996-01-01

    Turbulent flows that exhibit inhomogeneities in the streamwise direction pose a particular challenge to numerical simulation approaches due to the need to prescribe time-dependent turbulent inflow conditions. In most cases the flow downstream is more or less 'driven' by the conditions at the inlet, making it necessary to specify realistic turbulent fluctuations that are in equilibrium with the assumed mean flow. This requirement often dictates that the inflow data should satisfy the Navier-Stokes equations, which in turn implies that an independent simulation be used to generate them. Detailed simulations for the purpose of creating inflow conditions can be costly and thus certain levels of approximation are desirable. In this paper we shall focus on an approximate yet accurate method for generating inflow conditions for spatially-developing boundary layer simulations. The proposed method is essentially a simplification of the method of Spalart and Leonard (1985), who devised an ingenious transformation that allows for the calculation of spatially evolving boundary layers in conjunction with periodic boundary conditions applied in the streamwise direction. While this method is elegant and highly accurate, it is more complicated than is necessary for the purpose of generating inflow data. A few key approximations are used in this work to arrive at a 'modified Spalart method' that is very easy to implement and efficient to use. The new method is shown to yield results that compare well with the computations of Spalart (1988). When used as a means of generating inflow data, the modified Spalart method is shown to be superior to existing approaches.

  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. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  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. The impact of clinical simulation on learner self-efficacy in pre-registration nursing education.

    PubMed

    Pike, Tamsin; O'Donnell, Victoria

    2010-07-01

    Clinical simulation is becoming increasingly popular in pre-registration nursing education. Incorporating teaching and learning strategies that enhance learner self-efficacy will theoretically improve clinical competence (Bandura, 1986, 1997). This paper presents the findings of a study that aimed to explore the impact of clinical simulation on self-efficacy beliefs amongst pre-registration nurses. A preliminary study (Pike, 2008) used a pre- and post-test design to measure learner self-efficacy before and after a clinical simulation session. Qualitative responses to questions on the post-test questionnaire provided themes to explore in a focus group interview with a convenience sample of nine participants. Thematic content analysis of the interview highlighted two principal findings. Firstly, students described low levels of self-efficacy with regards to communication skills, an area identified as a priority within pre-registration nursing education (NMC, 2007a). Second, students highlighted the need for learning experiences within clinical simulation to be more authentic, to improve the theory to practice gap. It is argued by incorporating strategies within clinical simulation that enhance learner self-efficacy, overall clinical competence will be improved. Suggestions for how pedagogical approaches may be developed within clinical simulation are discussed, whilst acknowledging the limitations of the small scale nature of the study. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. 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

  20. 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.

  1. 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

  2. The Relationship Between Levels of Fidelity in Simulation, Traditional Clinical Experiences and Objectives.

    PubMed

    Gore, Teresa

    2017-06-15

    The purpose of this study was to explore the relationship of baccalaureate nursing students' (BSN) perceived learning effectiveness using the Clinical Learning Environments Comparison Survey of different levels of fidelity simulation and traditional clinical experiences. A convenience sample of 103 first semester BSN enrolled in a fundamental/assessment clinical course and 155 fifth semester BSN enrolled in a leadership clinical course participated in this study. A descriptive correlational design was used for this cross-sectional study to evaluate students' perceptions after a simulation experience and the completion of the traditional clinical experiences. The subscales measured were communication, nursing leadership, and teaching-learning dyad. No statistical differences were noted based on the learning objectives. The communication subscale showed a tendency toward preference for traditional clinical experiences in meeting students perceived learning for communication. For student perceived learning effectiveness, faculty should determine the appropriate level of fidelity in simulation based on the learning objectives.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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…

  11. 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…

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  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. 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.

  19. Comparison of Heat Transfer from Airfoil in Natural and Simulated Icing Conditions

    NASA Technical Reports Server (NTRS)

    Gelder, Thomas F.; Lewis, James P.

    1951-01-01

    An investigation of the heat transfer from an airfoil in clear air and in simulated icing conditions was conducted in the NACA Lewis 6- by 9-foot icing-research tunnel in order to determine the validity of heat-transfer data as obtained in the tunnel. This investiation was made on the same model NACA 65,2-016 airfoil section used in a previous flight study, under similar heating, icing, and operating conditions. The effect of tunnel turbulence, in clear air and in icingwas indicated by the forward movement of transition from laminar to turbulent heat transfer. An analysis of the flight results showed the convective heat transfer in icing to be considerably different from that measured in clear air and. only slightly different from that obtained in the icing-research tunnel during simulated icing.

  20. 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

    2017-07-01

    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.

  1. Estimating thermodynamic expectations and free energies in expanded ensemble simulations: Systematic variance reduction through conditioning

    NASA Astrophysics Data System (ADS)

    Athènes, Manuel; Terrier, Pierre

    2017-05-01

    Markov chain Monte Carlo methods are primarily used for sampling from a given probability distribution and estimating multi-dimensional integrals based on the information contained in the generated samples. Whenever it is possible, more accurate estimates are obtained by combining Monte Carlo integration and integration by numerical quadrature along particular coordinates. We show that this variance reduction technique, referred to as conditioning in probability theory, can be advantageously implemented in expanded ensemble simulations. These simulations aim at estimating thermodynamic expectations as a function of an external parameter that is sampled like an additional coordinate. Conditioning therein entails integrating along the external coordinate by numerical quadrature. We prove variance reduction with respect to alternative standard estimators and demonstrate the practical efficiency of the technique by estimating free energies and characterizing a structural phase transition between two solid phases.

  2. 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.

  3. 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.

  4. 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.

  5. Characterization and conditioning by cementation and compaction of ashes coming from simulated radwastes

    SciTech Connect

    Canadas, L.; Vale, J.; Salvador, L.

    1994-12-31

    The statement and the results of a systematic program of characterization and evaluation of conditioning by cementation and supercompaction of ashes coming from different simulated radwastes are presented. The main program objectives are to define the influence of the most important operating parameters of conditioning methods on the mechanical properties of the conditioned products and to obtain the guidelines for the optimization of their final storage, evaluating the achievable volume reduction and its relation with mechanical strength. The study is based on the physical and chemical characterization of the ashes and the determination of their behavior with respect to two conditioning methods: cementation and high pressure compaction, to determine the strength development, the mechanical stability, and the volume reduction achieved. The ashes are obtained by incineration of low activity simulated radwastes, which represent different real wastes with high volume to activity ratio. The conditioning by cementation is tested over a series of cementitious pastes made with two cement types, changing in ash and water content. Products are controlled by measuring volume, setting time, expansion, and strength. High pressure compaction tests are made at laboratory scale, measuring the ash volume reduction as a function of compacting pressure.

  6. Analysis of driver speeds under night driving conditions using a driving simulator.

    PubMed

    Bella, Francesco; Calvi, Alessandro; D'Amico, Fabrizio

    2014-06-01

    Accident statistics demonstrate that there should be a greater focus on nighttime driving to improve our knowledge of driver behavior under poor lighting conditions. However, the current geometric design criteria do not take into account driving at night. Moreover, studies that propose predictive models of operating speed only consider daytime driving conditions. This study compares driver speed behavior during daytime and nighttime driving and models operating speeds and speed differentials, identifying significant factors that influence speed behavior under different lighting conditions. The research was carried out using a driving simulator for a section of an existing two-lane rural road composed of 39 tangent-curve configurations. Speed profiles were recorded for 40 drivers under simulated daytime and nighttime driving conditions. New predictive speed models, differentiated for daytime and nighttime driving, are proposed that highlight the effects of different geometric predictors under different visibility conditions. Specifically, predictive models for operating speed on curves identified the inverse of the radius and the deflection angle of the curve as predictors under both driving conditions. For speed differentials based on the 85th percentile for maximum speed reduction (85 MSR), we found that the inverse of the approaching tangent length and of the curve radius significantly explained the dependent variable in both cases, with a higher dependence of nighttime 85 MSR on the curve geometry than on the tangent length. Tangent length had a significant effect on operating speed for independent tangents only for the daytime model, whereas the inverse of the previous radius was confirmed as a predictor for both visibility conditions. This research may influence design considerations for nighttime driving by providing evidence of the effects of nighttime conditions on driver speed choices and road safety. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Comparison of Psychophysiological Stress in Physiotherapy Students Undertaking Simulation and Hospital-Based Clinical Education.

    PubMed

    Judd, Belinda Karyn; Alison, Jennifer Ailsey; Waters, Donna; Gordon, Christopher James

    2016-08-01

    Simulation-based clinical education often aims to replicate varying aspects of real clinical practice. It is unknown whether learners' stress levels in simulation are comparable with those in clinical practice. The current study compared acute stress markers during simulation-based clinical education with that experienced in situ in a hospital-based environment. Undergraduate physiotherapy students' (n = 33) acute stress responses [visual analog scales of stress and anxiety, continuous heart rate (HR), and saliva cortisol] were assessed during matched patient encounters in simulation-based laboratories using standardized patients and during hospital clinical placements with real patients. Group differences in stress variables were compared using repeated measures analysis of variance for 3 time points (before, during the patient encounter, and after) at 2 settings (simulation and hospital). Visual analog scale stress and anxiety as well as HR increased significantly from baseline levels before the encounter in both settings (all P < 0.05). Stress and anxiety were significantly higher in simulation [mean (SD), 45 (22) and 44 (25) mm; P = 0.003] compared with hospital [mean (SD), 31 (21) and 26 (20) mm; P = 0.002]. The mean (SD) HR during the simulation patient encounter was 90 (16) beats per minute and was not different compared with hospital [mean (SD), 87 (15) beats per minute; P = 0.89]. Changes in salivary cortisol before and after patient encounters were not statistically different between settings [mean (SD) simulation, 1.5 (2.4) nmol/L; hospital, 2.5 (2.9) nmol/L; P = 0.70]. Participants' experienced stress on clinical placements, irrespective of the clinical education setting (simulation vs. hospital). This study revealed that psychological stress and anxiety were greater during simulation compared with hospital settings; however, physiological stress responses (HR and cortisol) were comparable. These results indicate that psychological stress may be

  8. CFD simulation of pressure and discharge surge in Francis turbine at off-design conditions

    NASA Astrophysics Data System (ADS)

    Chirkov, D.; Avdyushenko, A.; Panov, L.; Bannikov, D.; Cherny, S.; Skorospelov, V.; Pylev, I.

    2012-11-01

    A hybrid 1D-3D CFD model is developed for the numerical simulation of pressure and discharge surge in hydraulic power plants. The most essential part - the turbine itself - is simulated directly using 3D unsteady equations of turbulent motion of fluid-vapor mixture, while the rest of the hydraulic system is simulated in frames of 1D hydro-acoustic model. Thus the model accounts for the main factors responsible for excitation and propagation of pressure and discharge waves in hydraulic power plant. Boundary conditions at penstock inlet and draft tube outlet are discussed in detail. Then simulations of dynamic behavior at part load and full load operating points are performed. It is shown that the numerical model is able to capture self-excited oscillations in full load conditions. The influence of penstock length and flow structure behind the runner are investigated. The presented approach seems to be a promising tool for prediction and investigation the dynamic behavior in hydraulic power plants.

  9. N-body simulations with generic non-Gaussian initial conditions II: halo bias

    SciTech Connect

    Wagner, Christian; Verde, Licia E-mail: liciaverde@icc.ub.edu

    2012-03-01

    We present N-body simulations for generic non-Gaussian initial conditions with the aim of exploring and modelling the scale-dependent halo bias. This effect is evident on very large scales requiring large simulation boxes. In addition, the previously available prescription to implement generic non-Gaussian initial conditions has been improved to keep under control higher-order terms which were spoiling the power spectrum on large scales. We pay particular attention to the differences between physical, inflation-motivated primordial bispectra and their factorizable templates, and to the operational definition of the non-Gaussian halo bias (which has both a scale-dependent and an approximately scale-independent contributions). We find that analytic predictions for both the non-Gaussian halo mass function and halo bias work well once a fudge factor (which was introduced before but still lacks convincing physical explanation) is calibrated on simulations. The halo bias remains therefore an extremely promising tool to probe primordial non-Gaussianity and thus to give insights into the physical mechanism that generated the primordial perturbations. The simulation outputs and tables of the analytic predictions will be made publicly available via the non-Gaussian comparison project web site http://icc.ub.edu/∼liciaverde/NGSCP.html.

  10. Turbulence Simulation of Laboratory Wind-Wave Interaction in High Winds and Upscaling to Ocean Conditions

    DTIC Science & Technology

    2016-12-22

    December 2016 Award Number: N00014-12-10184 Turbulence Simulation of Laboratory Wind-Wave Interaction in High Winds and Upscaling to Ocean ...strongly forced ocean conditions where the wave spectral bandwidth is much broader. Overall, the fundamental aerodynamic behavior associated with...between the atmosphere and ocean . This is particularly important at high winds since air-sea fluxes substantially affect tropical cyclone (hurricane

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. [Method for direct generation data for formatted case report forms based on requirement for data authenticity in actual clinical conditions].

    PubMed

    Shao, Ming-Yi; Liu, Bao-Yan; He, Li-Yun; Zhang, Run-Shun

    2013-04-01

    Data authenticity is the basic requirement of clinical studies. In actual clinical conditions how to establish formatted case report forms (CRF) in line with the requirement for data authenticity is the key to ensure clinical data quality. On the basis of the characteristics of clinical data in actual clinical conditions, we determined elements for establishing formatted case report forms by comparing differences in data characteristics of CRFs in traditional clinical studies and in actual clinical conditions, and then generated formatted case report forms in line with the requirement for data authenticity in actual clinical conditions. The data of formatted CRFs generated in this study could not only meet the requirement for data authenticity of clinical studies in actual clinical conditions, but also comply with data management practices for clinical studies, thus it is deemed as a progress in technical methods.

  18. Measuring agreement between rating interpretations and binary clinical interpretations of images: a simulation study of methods for quantifying the clinical relevance of an observer performance paradigm

    NASA Astrophysics Data System (ADS)

    Chakraborty, Dev P.

    2012-05-01

    Laboratory receiver operating characteristic (ROC) studies, that are often used to evaluate medical imaging systems, differ from ‘live’ clinical interpretations in several respects which could compromise their clinical relevance. The aim was to develop methodology for quantifying the clinical relevance of a laboratory ROC study. A simulator was developed to generate ROC ratings data and binary clinical interpretations classified as correct or incorrect for a common set of images interpreted under clinical and laboratory conditions. The area under the trapezoidal ROC curve (AUC) was used as the laboratory figure-of-merit and the fraction of correct clinical decisions as the clinical figure-of-merit. Conventional agreement measures (Pearson, Spearman, Kendall and kappa) between the bootstrap-induced fluctuations of the two figures of merit were estimated. A jackknife pseudovalue transformation applied to the figures of merit was also investigated as a way to capture agreement existing at the individual image level that could be lost at the figure-of-merit level. It is shown that the pseudovalues define a relevance-ROC curve. The area under this curve (rAUC) measures the ability of the laboratory figure-of-merit-based pseudovalues to correctly classify incorrect versus correct clinical interpretations. Therefore, rAUC is a measure of the clinical relevance of an ROC study. The conventional measures and rAUC were compared under varying simulator conditions. It was found that design details of the ROC study, namely the number of bins, the difficulty level of the images, the ratio of disease-present to disease-absent images and the unavoidable difference between laboratory and clinical performance levels, can lead to serious underestimation of the agreement as indicated by conventional agreement measures, even for perfectly correlated data, while rAUC showed high agreement and was relatively immune to these details. At the same time rAUC was sensitive to factors such

  19. Measuring agreement between rating interpretations and binary clinical interpretations of images: a simulation study of methods for quantifying the clinical relevance of an observer performance paradigm.

    PubMed

    Chakraborty, Dev P

    2012-05-21

    Laboratory receiver operating characteristic (ROC) studies, that are often used to evaluate medical imaging systems, differ from 'live' clinical interpretations in several respects which could compromise their clinical relevance. The aim was to develop methodology for quantifying the clinical relevance of a laboratory ROC study. A simulator was developed to generate ROC ratings data and binary clinical interpretations classified as correct or incorrect for a common set of images interpreted under clinical and laboratory conditions. The area under the trapezoidal ROC curve (AUC) was used as the laboratory figure-of-merit and the fraction of correct clinical decisions as the clinical figure-of-merit. Conventional agreement measures (Pearson, Spearman, Kendall and kappa) between the bootstrap-induced fluctuations of the two figures of merit were estimated. A jackknife pseudovalue transformation applied to the figures of merit was also investigated as a way to capture agreement existing at the individual image level that could be lost at the figure-of-merit level. It is shown that the pseudovalues define a relevance-ROC curve. The area under this curve (rAUC) measures the ability of the laboratory figure-of-merit-based pseudovalues to correctly classify incorrect versus correct clinical interpretations. Therefore, rAUC is a measure of the clinical relevance of an ROC study. The conventional measures and rAUC were compared under varying simulator conditions. It was found that design details of the ROC study, namely the number of bins, the difficulty level of the images, the ratio of disease-present to disease-absent images and the unavoidable difference between laboratory and clinical performance levels, can lead to serious underestimation of the agreement as indicated by conventional agreement measures, even for perfectly correlated data, while rAUC showed high agreement and was relatively immune to these details. At the same time rAUC was sensitive to factors such as

  20. 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.

  1. 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.

  2. Using a Clinical Knowledge Base to Assess Comorbidity Interrelatedness Among Patients with Multiple Chronic Conditions

    PubMed Central

    Zulman, Donna M.; Martins, Susana B.; Liu, Yan; Tu, Samson W.; Hoffman, Brian B.; Asch, Steven M.; Goldstein, Mary K.

    2015-01-01

    Decision support tools increasingly integrate clinical knowledge such as medication indications and contraindications with electronic health record (EHR) data to support clinical care and patient safety. The availability of this encoded information and patient data provides an opportunity to develop measures of clinical decision complexity that may be of value for quality improvement and research efforts. We investigated the feasibility of using encoded clinical knowledge and EHR data to develop a measure of comorbidity interrelatedness (the degree to which patients’ co-occurring conditions interact to generate clinical complexity). Using a common clinical scenario—decisions about blood pressure medications in patients with hypertension—we quantified comorbidity interrelatedness by calculating the number of indications and contraindications to blood pressure medications that are generated by patients’ comorbidities (e.g., diabetes, gout, depression). We examined properties of comorbidity interrelatedness using data from a decision support system for hypertension in the Veterans Affairs Health Care System. PMID:26958279

  3. 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.

  4. 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.

  5. Simulating herbicide volatilization from bare soil affected by atmospheric conditions and limited solubility in water.

    PubMed

    Yates, S R

    2006-11-15

    A numerical model that simulates pesticide fate was developed to predictthe behavior of triallate after application to a field soil. The model has options that allow water and/ or heat transport and can limit simulated aqueous-phase concentrations to triallate solubility in water. Several methods for describing the volatilization boundary condition were tested to assess the accuracy in predicting the volatilization rate, including an approach that requires no atmospheric information and an approach that couples soil and atmospheric processes. Four scenarios were constructed and simulated, to compare with measured volatilization rates. The peak measured volatilization rate (168 g ha(-1) h(-1)) was most accurately predicted with the scenario that included the most complex model (100 g ha(-1) h(-1)). The simplest model overpredicted the peak rate (251 g ha(-1) h(-1)), and the others underpredicted the peak rate (16-67 g ha(-1) h(-1)). The simulations that limited aqueous solubility provided relatively similar values for the total emissions (21-37% of applied triallate), indicating that simplified models may compare well with measurements (31% of applied). A prospective simulation over a period of 100 days showed that applying triallate to the soil surface would ultimately lead to atmospheric emissions of 80% of the applied material with 6% remaining in soil. Incorporating triallate to a depth of 10 cm would reduce emissions to less than 5% and lead to 41% remaining in soil.

  6. 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.

  7. 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.

  8. 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

  9. Physical medicine and rehabilitation conditions in the Astrodome clinic after hurricane Katrina.

    PubMed

    Chiou-Tan, Faye Y; Bloodworth, Donna M; Kass, Joseph S; Li, Xiaoqi; Gavagan, Thomas F; Mattox, Kenneth; Rintala, Diana H

    2007-09-01

    To report the physical medicine and rehabilitation (PMR) conditions seen in the Astrodome Clinic after Hurricane Katrina. Retrospective chart analysis from the county hospital-sponsored disaster-relief clinic in large urban city, including a study of 239 patients with 292 PMR conditions. The total number of patients seen in the Astrodome Medical Clinic was 11,245. The Astrodome database was reviewed for PMR condition diagnostic codes. A retrospective chart analysis was conducted, including date of visit, age, gender, ethnicity, and PMR diagnosis category. Descriptive statistics were obtained for the entire sample. chi2 or t tests were used to determine gender, age, or date-of-service predominance for the most common diagnostic categories. Mean +/- SD age was 45.7 +/- 14.3 yrs; 56% were women, 43% were men (1% unspecified), and 76% were African American. The majority (75%) of PMR conditions presented in the first week. Most frequent were swollen feet and legs (22%), leg pain and cramps (17%), headache (12%), and neck and back pain (10%). Persons with headaches were younger than those without (41.3 vs. 46.3 yrs, P = 0.048). Persons with neck and/or back pain were older than those without those conditions (51.3 vs. 44.8 yrs, P = 0.004). Women had more headaches (20.9%) than did men (6.7%, P = 0.002). There were no Caucasians with leg pain/cramps, whereas 20.2% of African Americans had this condition (P = 0.028). This study documents the time of clinic presentation and most frequent types of PMR conditions of patients treated in the Astrodome Clinic after a historic hurricane. Most PMR conditions were treated by PMR personnel during the first week. Thus, future disaster planning should include PMR professionals as early responders.

  10. 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.

  11. The Family-Oriented Clinical Simulation: An Interdisciplinary Tool for Professional Growth.

    ERIC Educational Resources Information Center

    Shapiro, Johanna; Green, Janet

    1980-01-01

    A family-oriented clinical simulation for training physical therapists is described and compared to other role-playing techniques. Advantages, disadvantages, and potential contributions to the student's professional growth are discussed. (SK)

  12. 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

  13. 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

  14. 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…

  15. 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…

  16. Evaluating the effectiveness of four contextual features in classifying annotated clinical conditions in emergency department reports.

    PubMed

    Chu, David; Dowling, John N; Chapman, Wendy W

    2006-01-01

    Determine how four contextual features (Validity, Certainty, Directionality, and Temporality) contribute to classification of respiratory syndrome-related clinical conditions as acute, chronic, or absent from manual annotations in Emergency Department Reports. Based on the results, we will direct our research towards automatic identification of the contextual features found to be discriminating. A physician annotated all instances of 56 clinical conditions in 120 ED reports and encoded four contextual features for every annotation. We classified clinical conditions using the contextual features and measured agreement to reference standard classifications made by the physician using a weighted kappa (Kw). Kw was 0.518 when not using any of the features and 0.953 when using all of the features. Validity, Directionality, and Temporality all improved accuracy. Negation(Directionality) was the most important feature for improving accuracy. Using Certainty made the classification worse.

  17. ALERT: a clinical case simulator program for serious, communicable, and rare diseases.

    PubMed

    Brai, A; Valleron, A J

    1995-01-01

    ALERT is an intelligent Tutoring System (ITS) based on clinical case simulation. Its purpose is to assist in the training of general practitioners regarding the diagnosis and the control of serious, communicable, and rare diseases, such as anthrax, plague, and smallpox. ALERT provides both monitoring techniques and treatment protocols and is structured into two independent sections: one devoted to the simulation of the clinical case and the other to detailed description of disease.

  18. 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

  19. 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

  20. Measuring agreement between ratings interpretations and binary clinical interpretations of images: a simulation study of methods for quantifying the clinical relevance of an observer performance paradigm

    PubMed Central

    Chakraborty, Dev P.

    2012-01-01

    Laboratory receiver operating characteristic (ROC) studies, that are often used to evaluate medical imaging systems, differ from “live” clinical interpretations in several respects which could compromise their clinical relevance. The aim was to develop methodology for quantifying the clinical relevance of a laboratory ROC study. A simulator was developed to generate ROC ratings data and binary clinical interpretations classified as correct or incorrect for a common set of images interpreted under clinical and laboratory conditions. The area under the trapezoidal ROC curve was used as the laboratory figure-of-merit and the fraction of correct clinical decisions as the clinical figure-of-merit. Conventional agreement measures (Pearson, Spearman, Kendall and kappa) between the bootstrap-induced fluctuations of the two figures-of-merit were estimated. A jackknife pseudovalue transformation applied to the figures-of-merit was also investigated as a way to capture agreement existing at the individual image level that could be lost at the figure-of-merit level. It is shown that the pseudovalues define a relevance ROC curve the area under which (rAUC) measures the ability of the laboratory figure-of-merit based pseudovalues to correctly classify incorrect vs. correct clinical interpretations, and is a measure of the clinical relevance of an ROC study. The conventional measures and rAUC were compared under varying simulator conditions. It was found that design details of the ROC study, namely the number of bins, the difficulty level of the images, the ratio of disease-present to disease-absent images, and the unavoidable difference between laboratory and clinical performance levels, can seriously underestimate the agreement as indicated by conventional agreement measures, even for perfectly correlated data, while rAUC showed high agreement and was relatively immune to these details. At the same time rAUC was sensitive to factors such as intrinsic correlation between the