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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. MRI-guided transurethral ultrasound therapy of the prostate gland: simulations under clinical conditions

    NASA Astrophysics Data System (ADS)

    N'Djin, W. A.; Burtnyk, M.; Kobelevskiy, I.; Bronskill, M.; Chopra, R.

    2011-09-01

    The feasibility of performing MRI-guided transurethral ultrasound therapy in humans has been shown by our group for the treatment of small subvolumes prior to radical prostatectomy. One challenge is to use this technology to treat a volume of tissue equivalent to the entire prostate gland. This simulation study evaluates the feasibility of treating the whole prostate gland and characterizes the nature of the treatment with respect to treatment time, accuracy, and safety. A numerical model was used to simulate a multi-element heating applicator rotating inside the urethra in five human prostates. 3D prostate profiles were segmented from clinical MR images obtained from subjects after insertion of a transurethral heating applicator into the prostate gland. Clinical treatment planning conditions were simulated including device orientation, prostate & rectum geometry, temperature uncertainty, imaging time, and spatial resolution. During ultrasound exposures, acoustic power, frequency and rotation rate were varied based on the prostate radius and on temperature feedback every 5 seconds using MR thermometry. Two treatment approaches (10 or 20 W.cm-2 acoustic power) were tested as well as single and dual-frequency strategies (4.05/13.10 MHz). A 20 W.cm-2 dual-frequency treatment was shown to be the most efficient configuration in achieving full human prostate treatments. Increasing the power from 10 to 20 W.cm-2 led, on average, to treatment times shorter by 50%. Full prostate coagulations were performed in 20.6±1.6 min at a rate of 1.6±0.2 cm3.min-1, and resulted in <8% of undertreated tissue. This configuration succeeded in preserving high-priority critical regions such as the adjacent rectal wall tissues. The principles of prostate thermal therapy using an MR thermometry-guided transurethral ultrasound technique were shown in simulations to be suitable for full gland treatment in prostate geometries derived from human subjects undergoing partial coagulations. Dual

  3. 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

  4. 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

  5. Computerized Clinical Simulations.

    ERIC Educational Resources Information Center

    Reinecker, Lynn

    1985-01-01

    Describes technique involved in designing a clinical simulation problem for the allied health field of respiratory therapy; discusses the structure, content, and scoring categories of the simulation; and provides a sample program which illustrates a programming technique in BASIC, including a program listing and a sample flowchart. (MBR)

  6. Bacteria under simulated Martian conditions.

    PubMed

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

    1964-01-01

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

  7. 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…

  8. Lunar Polar Environmental Testing: Regolith Simulant Conditioning

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie Elise

    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.

  9. Virus Silicification under Simulated Hot Spring Conditions

    NASA Astrophysics Data System (ADS)

    Laidler, James R.; Stedman, Kenneth M.

    2010-07-01

    Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses have not. Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained, and a clear elemental signature of phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDS).

  10. Virus silicification under simulated hot spring conditions.

    PubMed

    Laidler, James R; Stedman, Kenneth M

    2010-01-01

    Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses have not. Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained, and a clear elemental signature of phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDS).

  11. Simulating protein folding in different environmental conditions.

    PubMed

    Homouz, Dirar

    2014-01-01

    Molecular dynamics simulations have become an invaluable tool in investigating the dynamics of protein folding. However, most computational studies of protein folding assume dilute aqueous simulation conditions in order to reduce the complexity of the system under study and enhance the efficiency. Nowadays, it is evident that environmental conditions encountered in vivo (or even in vitro) play a major role in regulating the dynamics of protein folding especially when one considers the highly condensed environment in the cellular cytoplasm. In order to factor in these conditions, we can utilize the high efficiency of well-designed low resolution (coarse-grained) simulation models to reduce the complexity of these added protein-milieu interactions involving different time and length scales. The goal of this chapter is to describe some recently developed coarse-grained simulation techniques that are specifically designed to go beyond traditional aqueous solvent conditions. The chapter also gives the reader a flavor of the things that we can study using such "smart" low resolution models.

  12. Oncologic conditions that simulate common sports injuries.

    PubMed

    Krych, Aaron; Odland, Andrew; Rose, Peter; Dahm, Diane; Levy, Bruce; Wenger, Doris; Stuart, Michael; Sim, Franklin

    2014-04-01

    Primary bone and soft-tissue tumors that mimic common sports injuries are relatively rare and are not often encountered by most orthopaedists. Prompt and accurate diagnosis of these tumors is crucial to maximize the clinical outcome. Many bone and soft-tissue tumors present disproportionately in young and active patients who are often involved in athletic activities. Thus, the clinician may misdiagnose these rare tumors as more common sports injuries. Symptoms that should raise suspicion for a neoplastic process include pain unrelated to activity and a clinical course that does not follow the typically expected recovery for a common sports injury. An awareness of the salient features of several bone and soft-tissue tumors as well as nononcologic processes that may simulate sports injuries can aid clinicians in the prompt diagnosis and clinical decision making of these rare tumors. PMID:24668352

  13. Remote ischemic conditioning: Current clinical perspectives.

    PubMed

    Le Page, Sophie; Prunier, Fabrice

    2015-08-01

    Remote ischemic conditioning (RIC) constitutes a promising method in which a tissue or organ is exposed to intermittent ischemia/reperfusion periods enabling it to provide protection to a distant target organ. RIC has been tested in various clinical settings through its simple application by means of intermittent inflation of a blood pressure cuff placed on a limb, primarily evaluating its potential abilities to decrease myocardial injury biomarkers. Its use on other organs, such as the kidneys or brain, has recently been a topic of research. To date, no study has yet been powerful enough to reach a conclusion on the potential benefit of RIC on clinical outcomes. The future role of RIC in the clinical arena could be clarified by the large phase III trials currently underway targeting major outcomes as primary endpoints.

  14. 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…

  15. Conditional simulations for fields of extreme precipitation

    NASA Astrophysics Data System (ADS)

    Bechler, Aurélien; Vrac, Mathieu; Bel, Liliane

    2014-05-01

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

  16. DSMC simulations of OREX entry conditions

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Gupta, Roop N.; Price, Joseph M.

    1996-01-01

    Results of direct simulation Monte Carlo (DSMC) solutions are presented for the Japanese Orbital Reentry Experiment (OREX) vehicle, a 50 deg half-angle spherically blunted cone with a nose radius of 1.35 m and a base diameter of 3.4 m. The flow conditions simulated are those for entry into the Earth's atmosphere at a nominal velocity of about 7.4 km/s and zero incidence. Calculations are made for the higher altitude portion of entry, encompassing the transitional flow regime (altitudes of 200 to 80 km). Comparisons with flight measured values are made for axial acceleration, surface pressure, and stagnation point heating.

  17. Simulation of hydrocephalus condition in infant head

    NASA Astrophysics Data System (ADS)

    Wijayanti, Erna; Arif, Idam

    2014-03-01

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

  18. Accuracy vs. computational time: translating aortic simulations to the clinic.

    PubMed

    Brown, Alistair G; Shi, Yubing; Marzo, Alberto; Staicu, Cristina; Valverde, Isra; Beerbaum, Philipp; Lawford, Patricia V; Hose, D Rodney

    2012-02-01

    State of the art simulations of aortic haemodynamics feature full fluid-structure interaction (FSI) and coupled 0D boundary conditions. Such analyses require not only significant computational resource but also weeks to months of run time, which compromises the effectiveness of their translation to a clinical workflow. This article employs three computational fluid methodologies, of varying levels of complexity with coupled 0D boundary conditions, to simulate the haemodynamics within a patient-specific aorta. The most comprehensive model is a full FSI simulation. The simplest is a rigid walled incompressible fluid simulation while an alternative middle-ground approach employs a compressible fluid, tuned to elicit a response analogous to the compliance of the aortic wall. The results demonstrate that, in the context of certain clinical questions, the simpler analysis methods may capture the important characteristics of the flow field.

  19. 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)

  20. Materials behavior under space simulation conditions

    NASA Astrophysics Data System (ADS)

    Gavrylov, R.; Eremenko, V.; Pokhyl, Y.

    The report contains review of researches carried out in SR&DB ILTPE NASU within last decade in the field of crygenic-vacuum and space material science, directed on an establishment of a nature of structural and functional materials physical properties changes under separated and combined laboratory simulating. Space factors influence. The aim of such researches is the definition of serviceability and durability of materials, used in space engineering, in extreme conditions influence of deep vacuum, electromagnetic radiation of the Sun, powerful flows of corpuscular radiation in radiation belts of the Earth, microgravitation, low temperatures, significant cyclic thermomechanical gradient stresses, magnetic fields, high dynamic loadings, vibrations and other factors. Each of the listed factors differently influences on changes of mechanical, optical, electrical, thermophysical, tribotechnical and other properties of materials, and their resulting joint influence is not additive. Generally real Space negatively influences on materials and designs elements of space vehicles, resulting to essential degradation of their operational characteristics. There are two approaches to decision of a problem of estimation and selection of materials, suitable to use in so specific conditions. The first consists in regular investigations of materials complex of physical&mechanical properties in conditions of separated and combined ground simulation of Space factors. The second assumes exhibiting of materials and designs elements in open Space conditions in real space flight with the subsequent investigation of their physical properties. These approaches are complementary, and in SR&DB ILTPE the works are carried out in these both directions. The description of the created laboratory -test base with specialized cryogenic, vacuum and simulating equipment for various types of researches in conditions of ground simulation of major outer Space factors is given. The report is represent the

  1. 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.

  2. 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.

  3. Capillary pressure experiments under simulated reservoir conditions

    NASA Astrophysics Data System (ADS)

    Kummerow, J.; Spangenberg, E.

    2012-04-01

    The contribution of residual trapping to a long-term storage of CO2 in saline aquifers mainly depends on the drainage capillary pressure of a reservoir and the hysteresis of the drainage and imbibition branches of the capillary pressure curve. However, the experimental database of capillary pressure measured at relevant pT conditions is still scarce. Here, we present an experimental set-up, which allows for the performance of capillary pressure experiments with a semi-permeable disk (porous plate) at simulated reservoir conditions. In the framework of the EU funded project CO2CARE, drainage and imbibition cycles are performed on Triassic sandstone samples. We use a temperature controlled oil pressure autoclave to apply a maximum confining pressure of 400 bar and a maximum working temperature of 150°C. The fluid displacement, and hence the sample saturation is controlled by a gear pump with a fine resolution of 0.01 ml. Additionally, the capillary pressure experiment is combined with measurements of elastic wave velocities as well as of the electrical resistivity. In this case, P and S wave velocities and the formation resistivity factor are determined as functions of the brine/ CO2 saturation. The experiment provides information about the efficiency of the capillary trapping of the sample and a calibration of the petrophysical properties on saturation.

  4. MCMC curve sampling and geometric conditional simulation

    NASA Astrophysics Data System (ADS)

    Fan, Ayres; Fisher, John W., III; Kane, Jonathan; Willsky, Alan S.

    2008-02-01

    We present an algorithm to generate samples from probability distributions on the space of curves. Traditional curve evolution methods use gradient descent to find a local minimum of a specified energy functional. Here, we view the energy functional as a negative log probability distribution and sample from it using a Markov chain Monte Carlo (MCMC) algorithm. We define a proposal distribution by generating smooth perturbations to the normal of the curve, update the curve using level-set methods, and show how to compute the transition probabilities to ensure that we compute samples from the posterior. We demonstrate the benefits of sampling methods (such as robustness to local minima, better characterization of multi-modal distributions, and access to some measures of estimation error) on medical and geophysical applications. We then use our sampling framework to construct a novel semi-automatic segmentation approach which takes in partial user segmentations and conditionally simulates the unknown portion of the curve. This allows us to dramatically lower the estimation variance in low-SNR and ill-posed problems.

  5. Respirator physiological effects under simulated work conditions.

    PubMed

    Bansal, Siddharth; Harber, Philip; Yun, David; Liu, David; Liu, Yihang; Wu, Samantha; Ng, David; Santiago, Silverio

    2009-04-01

    This study compared the physiological impacts of two respirator types in simulated work conditions. Fifty-six subjects included normal volunteers and persons with mild respiratory impairments (chronic rhinitis, mild COPD, and mild asthma). Respiratory parameters and electrocardiogram were measured using respiratory inductive plethysmography while performing eight work tasks involving low to moderate exertion using two respirators: (1) a dual cartridge half face mask (HFM) respirator, and (2) the N95. Mixed model regression analyses evaluating the effect of task and respirator type showed that task affected tidal volume, minute ventilation, breathing frequency and heart rate; all were greater in heavier tasks. Although respirator type did not affect respiratory volume parameters and flow rates, the HFM led to increase in the inspiratory time, reduction of the expiratory time, and increase in the duty cycle in comparison with the N95. The magnitude of differences was relatively small. The results suggest that most individuals, including persons with mild respiratory impairments, will physiologically tolerate either type of respirator at low to moderate exertion tasks. However, because effective protection depends on proper use, differences in subjective effect may have greater impact than physiological differences. Using respirators may be feasible on a widespread basis if necessary for maintaining essential services in the face of widespread concern about an infectious or terrorist threat. PMID:19180375

  6. 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.

  7. 42 CFR 493.1225 - Condition: Clinical cytogenetics.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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 through... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Clinical cytogenetics. 493.1225...

  8. 42 CFR 485.721 - 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... participation: Clinical records. The organization maintains clinical records on all patients in accordance with accepted professional standards, and practices. The clinical records are completely and...

  9. [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.

  10. Special training under simulated stat lab conditions.

    PubMed

    Green, M M; Hill, S

    1983-12-01

    A course has been devised to simulate a hospital stat lab environment for students in a 2-year MLT Associate Degree program. This course ensures that each student will individually perform a wide variety of laboratory procedures and report results under hospital-like circumstances. This course, which has received favorable comment from NAACLS, circumvents problems of insufficient placement situations, inadequate supervision, and limited variety of student experience in hospital sites. Course procedures, objectives, and student evaluation methods are described.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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,…

  16. 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…

  17. 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.

  18. 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.

  19. 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

  20. 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. PMID:24716674

  1. 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

  2. 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

  3. Amplitude variation in calibrated audiometer systems in clinical simulations.

    PubMed

    Barlow, Christopher; Davison, Lee; Ashmore, Mark; Weinstein, Ray

    2014-01-01

    Manual pure tone audiometry is considered to be the gold standard for the assessment of hearing thresholds and has been in consistent use for a long period of time. An increased legislative requirement to monitor and screen workers, and an increasing amount of legislation relating to hearing loss is putting greater reliance on this as a tool. There are a number of questions regarding the degree of accuracy of pure tone audiometry when undertaken in field conditions, particularly relating to the difference in conditions between laboratory calibration and clinical or industrial screening use. This study analyzed the output sound pressure level of four different commercial audiometers, all using TDH39 headphones and each of which had recently undergone calibration at an appropriate laboratory. Levels were measured using a Bruël and Kjaer Head and Torso simulator, which accurately replicates the size and shape of a human head, including the ears. A clinical environment was simulated by a trained audiometrist replacing the headphones for each test. Tests were undertaken at three presentation levels, and at the frequencies of 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz and 6 kHz. The results showed a high level of test-retest variability, both between different audiometers and within the same audiometer. Maximum variation of sound pressure level at the ear for the same tone presentation was 21 decibels, with a particularly high level of variation at 6 kHz for all meters. An audiometer with attenuating cups exhibited significantly higher variation than ones using supral-aural headphones. Overall the variation exhibited suggests that there is a higher degree of potential error with screening pure tone audiometry than is commonly assumed and that results particularly at the 6 kHz frequency need to be assessed carefully alongside other methods such as speech audiometry.

  4. 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.

  5. Extremophiles Survival to Simulated Space Conditions: An Astrobiology Model Study

    NASA Astrophysics Data System (ADS)

    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.

  6. 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

  7. 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. PMID:25573749

  8. Disruption simulation experiments and extrapolation to reactor conditions

    SciTech Connect

    Hassanein, A.; Konkashbaev, I.K.

    1998-08-01

    Laboratory experiments to simulate plasma disruptions have contributed significantly in many aspects to the understanding of the physical processes occurring during high-energy deposition on target material surfaces due to plasma instabilities. Laser light, electron beams, and plasma guns have been used worldwide to study disruption effects and erosion damage of candidate divertor materials. The differences among these simulation experiments are examined. The net power flux reaching the originally exposed surface depends on many parameters, such as type of energy deposited, target material, pulse duration, and geometrical factors. Experimental results have been evaluated and compared with theoretical predictions, and the overall relevance of simulation experiments to reactor conditions has been critically examined.

  9. 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.

  10. The simulation of natural low level light under lab's condition

    NASA Astrophysics Data System (ADS)

    Lin, Wanyi; Wang, Jinsong; Wang, Xuan; An, Zhiyong; Jiang, Hong

    2014-02-01

    Considering the needs of glimmer night vision system experiment, this paper has analyzed the working environment of glimmer night vision system, and based on this analysis the paper adopted double integrating sphere and collimator to simulate natural shimmer environment under the laboratory condition. By further analysis, we can conclude that as long as the field of collimator is larger than the field of night vision system, the natural micro light of night vision system testing can be simulated under the laboratory conditions, And the feasibility of this method is verified by experiment.

  11. Ischaemic conditioning: pitfalls on the path to clinical translation

    PubMed Central

    Przyklenk, Karin

    2015-01-01

    The development of novel adjuvant strategies capable of attenuating myocardial ischaemia-reperfusion injury and reducing infarct size remains a major, unmet clinical need. A wealth of preclinical evidence has established that ischaemic ‘conditioning’ is profoundly cardioprotective, and has positioned the phenomenon (in particular, the paradigms of postconditioning and remote conditioning) as the most promising and potent candidate for clinical translation identified to date. However, despite this preclinical consensus, current phase II trials have been plagued by heterogeneity, and the outcomes of recent meta-analyses have largely failed to confirm significant benefit. As a result, the path to clinical application has been perceived as ‘disappointing’ and ‘frustrating’. The goal of the current review is to discuss the pitfalls that may be stalling the successful clinical translation of ischaemic conditioning, with an emphasis on concerns regarding: (i) appropriate clinical study design and (ii) the choice of the ‘right’ preclinical models to facilitate clinical translation. PMID:25560903

  12. 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. 485.60 Section 485.60 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND...) Progress notes or other documentation that reflect patient reaction to treatment, tests, or injury, or...

  13. Response of HEPA filters to simulated-accident conditions

    SciTech Connect

    Gregory, W.S.; Martin, R.A.; Smith, P.R.; Fenton, D.E.

    1982-01-01

    High-efficiency particulate air (HEPA) filters have been subjected to simulated accident conditions to determine their response to abnormal operating events. Both domestic and European standard and high-capacity filters have been evaluated to determine their response to simulated fire, explosion, and tornado conditions. The HEPA filter structural limitations for tornado and explosive loadings are discussed. In addition, filtration efficiencies during these accident conditions are reported for the first time. Our data indicate efficiencies between 80% and 90% for shock loadings below the structural limit level. We describe two types of testing for ineffective filtration - clean filters exposed to pulse-entrained aerosol and dirty filters exposed to tornado and shock pulses. Efficiency and material loss data are described. Also, the resonse of standard HEPA filters to simulated fire conditions is presented. We describe a unique method of measuring accumulated combustion products on the filter. Additionally, data relating to pressure drop vs accumulated mass during plugging are reported for simulated combustion aerosols. The effects of concentration and moisture levels on filter plugging were evaluated. We are obtaining all of the above data so that mathematical models can be developed for fire, explosion, and tornado accident analysis computer codes. These computer codes can be used to assess the response of nuclear air cleaning systems to accident conditions.

  14. 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.

  15. 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.

  16. Zircoloy Cladding Oxidation Simulation for LWR under LOCA Conditions

    2003-04-25

    PRECIP-2 simulates zircaloy cladding oxidation under LOCA conditions of LWR’s. The code calculates oxygen concentration distribution across the cladding wall by solving the diffusion equation with moving boundary conditions, taking into account the structure change of the beta— phase, i.e. alpha precipitation during the cooling period. The code also predicts total oxygen uptake, thicknesses of alpha, beta and oxide layers.

  17. 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. PMID:27258807

  18. 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.

  19. Blitz Nevus: A Clinical Simulator of Melanoma.

    PubMed

    Alonso-Corral, M Jose; Ruiz-Villaverde, Ricardo; Sánchez-Cano, Daniel; Pulido-Fernández, Francisco

    2016-01-01

    A 17-year-old adolescent girl attended our clinic for a scheduled review of her nevus lesions. She complained about a lesion on the posterior region of her neck, which she had noticed approximately 2 years before. Even though it had not caused any symptoms, its appearance had changed according to her parents. The patient's medical history, as well as that of her family's, was unremarkable. PMID:27319960

  20. Analysis of Boundary Conditions for Crystal Defect Atomistic Simulations

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    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.

  1. 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…

  2. Campus Clinical: simulation-based curriculum designed to meet clinical course learning outcomes.

    PubMed

    Jarvis, Michelle; Rivers, Julie

    2014-01-01

    Campus Clinical is a simulation-based curriculum designed to meet the challenge of decreasing clinical spaces in maternal-child units. The curriculum framework is situated in a constructivist, experiential learning context, integrating Chickering and Gamson's principles for good practice in education. This innovative approach to meeting clinical course learning outcomes is transferable to a variety of settings.

  3. 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.

  4. 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.

  5. 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.

  6. Generating Optimal Initial Conditions for Smoothed Particle Hydrodynamics Simulations

    NASA Astrophysics Data System (ADS)

    Diehl, S.; Rockefeller, G.; Fryer, C. L.; Riethmiller, D.; Statler, T. S.

    2015-12-01

    We review existing smoothed particle hydrodynamics setup methods and outline their advantages, limitations, and drawbacks. We present a new method for constructing initial conditions for smoothed particle hydrodynamics simulations, which may also be of interest for N-body simulations, and demonstrate this method on a number of applications. This new method is inspired by adaptive binning techniques using weighted Voronoi tessellations. Particles are placed and iteratively moved based on their proximity to neighbouring particles and the desired spatial resolution. This new method can satisfy arbitrarily complex spatial resolution requirements.

  7. Generating optimal initial conditions for smooth particle hydrodynamics (SPH) simulations

    SciTech Connect

    Diehl, Steven; Rockefeller, Gabriel M; Fryer, Christopher L

    2008-01-01

    We present a new optimal method to set up initial conditions for Smooth Particle Hydrodynamics Simulations, which may also be of interest for N-body simulations. This new method is based on weighted Voronoi tesselations (WVTs) and can meet arbitrarily complex spatial resolution requirements. We conduct a comprehensive review of existing SPH setup methods, and outline their advantages, limitations and drawbacks. A serial version of our WVT setup method is publicly available and we give detailed instruction on how to easily implement the new method on top of an existing parallel SPH code.

  8. Atomistic Simulations of Material Properties under Extreme Conditions

    NASA Astrophysics Data System (ADS)

    An, Qi

    Extreme conditions involve low or high temperatures (> 1500 K), high pressures (> 30 MPa), high strains or strain rates, high radiation fluxes (> 100 dpa), and high electromagnetic fields (> 15T). Material properties under extreme conditions can be extremely different from those under normal conditions. Understanding material properties and performance under extreme conditions, including their dynamic evolution over time, plays an essential role in improving material properties and developing novel materials with desired properties. To understand material properties under extreme conditions, we use molecular dynamics (MD) simulations with recently developed reactive force fields (ReaxFF) and traditional embedded atom methods (EAM) potentials to examine various materials (e.g., energetic materials and binary liquids) and processes. The key results from the simulations are summarized below. Anisotropic sensitivity of RDX crystals: Based on the compress-and-shear reactive dynamics (CS-RD) simulations of cyclotrimethylene trinitramine (RDX) crystals, we predict that for mechanical shocks between 3 and 7 GPa, RDX is the most sensitive to shocks perpendicular to the (100) and (210) planes, while it is insensitive to those perpendicular to the (120), (111), and (110) planes. The simulations demonstrate that the molecular origin of anisotropic shock sensitivity is the steric hindrance to shearing of adjacent slip planes. Mechanisms of hotspot formation in polymer bonded explosives (PBXs): The simulations of a realistic model of PBXs reveal that hotspots may form at the nonplanar interfaces where shear relaxation leads to a dramatic temperature increase that persists long after the shock front has passed the interface. For energetic materials this temperature increase is coupled to chemical reactions that eventually lead to detonation. We show that decreasing the density of the binder eliminates the hotspots or reduces the sensitivity. Cavitation in binary metallic liquids

  9. 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.

  10. 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.

  11. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27511644

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

    PubMed

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

    2016-01-01

    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. PMID:27511644

  14. 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.

  15. 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

  16. 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

  17. Automating Identification of Multiple Chronic Conditions in Clinical Practice Guidelines

    PubMed Central

    Leung, Tiffany I.; Jalal, Hawre; Zulman, Donna M.; Dumontier, Michel; Owens, Douglas K.; Musen, Mark A.; Goldstein, Mary K.

    2015-01-01

    Many clinical practice guidelines (CPGs) are intended to provide evidence-based guidance to clinicians on a single disease, and are frequently considered inadequate when caring for patients with multiple chronic conditions (MCC), or two or more chronic conditions. It is unclear to what degree disease-specific CPGs provide guidance about MCC. In this study, we develop a method for extracting knowledge from single-disease chronic condition CPGs to determine how frequently they mention commonly co-occurring chronic diseases. We focus on 15 highly prevalent chronic conditions. We use publicly available resources, including a repository of guideline summaries from the National Guideline Clearinghouse to build a text corpus, a data dictionary of ICD-9 codes from the Medicare Chronic Conditions Data Warehouse (CCW) to construct an initial list of disease terms, and disease synonyms from the National Center for Biomedical Ontology to enhance the list of disease terms. First, for each disease guideline, we determined the frequency of comorbid condition mentions (a disease-comorbidity pair) by exactly matching disease synonyms in the text corpus. Then, we developed an annotated reference standard using a sample subset of guidelines. We used this reference standard to evaluate our approach. Then, we compared the co-prevalence of common pairs of chronic conditions from Medicare CCW data to the frequency of disease-comorbidity pairs in CPGs. Our results show that some disease-comorbidity pairs occur more frequently in CPGs than others. Sixty-one (29.0%) of 210 possible disease-comorbidity pairs occurred zero times; for example, no guideline on chronic kidney disease mentioned depression, while heart failure guidelines mentioned ischemic heart disease the most frequently. Our method adequately identifies comorbid chronic conditions in CPG recommendations with precision 0.82, recall 0.75, and F-measure 0.78. Our work identifies knowledge currently embedded in the free text of

  18. Automating Identification of Multiple Chronic Conditions in Clinical Practice Guidelines.

    PubMed

    Leung, Tiffany I; Jalal, Hawre; Zulman, Donna M; Dumontier, Michel; Owens, Douglas K; Musen, Mark A; Goldstein, Mary K

    2015-01-01

    Many clinical practice guidelines (CPGs) are intended to provide evidence-based guidance to clinicians on a single disease, and are frequently considered inadequate when caring for patients with multiple chronic conditions (MCC), or two or more chronic conditions. It is unclear to what degree disease-specific CPGs provide guidance about MCC. In this study, we develop a method for extracting knowledge from single-disease chronic condition CPGs to determine how frequently they mention commonly co-occurring chronic diseases. We focus on 15 highly prevalent chronic conditions. We use publicly available resources, including a repository of guideline summaries from the National Guideline Clearinghouse to build a text corpus, a data dictionary of ICD-9 codes from the Medicare Chronic Conditions Data Warehouse (CCW) to construct an initial list of disease terms, and disease synonyms from the National Center for Biomedical Ontology to enhance the list of disease terms. First, for each disease guideline, we determined the frequency of comorbid condition mentions (a disease-comorbidity pair) by exactly matching disease synonyms in the text corpus. Then, we developed an annotated reference standard using a sample subset of guidelines. We used this reference standard to evaluate our approach. Then, we compared the co-prevalence of common pairs of chronic conditions from Medicare CCW data to the frequency of disease-comorbidity pairs in CPGs. Our results show that some disease-comorbidity pairs occur more frequently in CPGs than others. Sixty-one (29.0%) of 210 possible disease-comorbidity pairs occurred zero times; for example, no guideline on chronic kidney disease mentioned depression, while heart failure guidelines mentioned ischemic heart disease the most frequently. Our method adequately identifies comorbid chronic conditions in CPG recommendations with precision 0.82, recall 0.75, and F-measure 0.78. Our work identifies knowledge currently embedded in the free text of

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Evidence of clinical competence by simulation, a hermeneutical observational study.

    PubMed

    Lejonqvist, Gun-Britt; Eriksson, Katie; Meretoja, Riitta

    2016-03-01

    Making the transition from theory to practise easier in nursing education through simulation is widely implemented all over the world, and there is research evidence of the positive effects of simulation. The pre-understanding for this study is based on a definition of clinical competence as encountering, knowing, performing, maturing and developing, and the hypothesis is that these categories should appear in simulated situations. The aim of the study was to explore the forms and expressions of clinical competence in simulated situations and furthermore to explore if and how clinical competence could be developed by simulation. An observational hermeneutic study with a hypothetic-deductive approach was used in 18 simulated situations with 39 bachelor degree nursing students. In the situations, the scenarios, the actors and the plots were described. The story told was "the way from suffering to health" in which three main plots emerged. The first was, doing as performing and knowing, which took the shape of knowing what to do, acting responsibly, using evidence and equipment, appearing confident and feeling comfortable, and sharing work and information with others. The second was, being as encountering the patient, which took the shape of being there for him/her and confirming by listening and answering. The third plot was becoming as maturing and developing which took the shape of learning in co-operation with other students. All the deductive categories, shapes and expressions appeared as dialectic patterns having their negative counterparts. The study showed that clinical competence can be made evident and developed by simulation and that the challenge is in encountering the patient and his/her suffering. PMID:26763209

  5. Thoracic outlet syndrome: a controversial clinical condition. Part 1: anatomy, and clinical examination/diagnosis

    PubMed Central

    Hooper, Troy L; Denton, Jeff; McGalliard, Michael K; Brismée, Jean-Michel; Sizer, Phillip S

    2010-01-01

    Thoracic outlet syndrome (TOS) is a frequently overlooked peripheral nerve compression or tension event that creates difficulties for the clinician regarding diagnosis and management. Investigators have categorized this condition as vascular versus neurogenic, where vascular TOS can be subcategorized as either arterial or venous and neurogenic TOS can subcategorized as either true or disputed. The thoracic outlet anatomical container presents with several key regional components, each capable of compromising the neurovascular structures coursing within. Bony and soft tissue abnormalities, along with mechanical dysfunctions, may contribute to neurovascular compromise. Diagnosing TOS can be challenging because the symptoms vary greatly amongst patients with the disorder, thus lending to other conditions including a double crush syndrome. A careful history and thorough clinical examination are the most important components in establishing the diagnosis of TOS. Specific clinical tests, whose accuracy has been documented, can be used to support a clinical diagnosis, especially when a cluster of positive tests are witnessed. PMID:21655389

  6. 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)

  7. 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.

  8. 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.

  9. 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

  10. Integrating a professional apprenticeship model with psychiatric clinical simulation.

    PubMed

    Crider, Mark C; McNiesh, Susan G

    2011-05-01

    In this article, we present a theory-based application of clinical simulation in psychiatric-mental health nursing education. As described by Benner, Sutphen, Leonard, and Day, a three-pronged apprenticeship that integrates intellectual, practical, and ethical aspects of the professional role is critical in the development of practical reasoning in nursing education and training. Clinical encounters are often fraught with ambiguity and uncertainty. Therefore, educating for a practice discipline requires experiential and situated learning. Using the three-pronged experiential model in simulated psychiatric-mental health nursing practice supports the development of critical nursing skills, ethics, and theoretical concepts. A clinical scenario is presented that demonstrates the application of this model of professional apprenticeship in psychiatric-mental health education. Applications of the concept presented may be used in training nurses new to the practice of psychiatric-mental health nursing.

  11. 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.

  12. 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.

  13. 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.

  14. 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. PMID:26802528

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  16. Bubble Augmented Propulsor Mixture Flow Simulation near Choked Flow Condition

    NASA Astrophysics Data System (ADS)

    Choi, Jin-Keun; Hsiao, Chao-Tsung; Chahine, Georges

    2013-03-01

    The concept of waterjet thrust augmentation through bubble injection has been the subject of many patents and publications over the past several decades, and computational and experimental evidences of the augmentation of the jet thrust through bubble growth in the jet stream have been reported. Through our experimental studies, we have demonstrated net thrust augmentation as high as 70%for air volume fractions as high as 50%. However, in order to enable practical designs, an adequately validated modeling tool is required. In our previous numerical studies, we developed and validated a numerical code to simulate and predict the performance of a two-phase flow water jet propulsion system for low void fractions. In the present work, we extend the numerical method to handle higher void fractions to enable simulations for the high thrust augmentation conditions. At high void fractions, the speed of sound in the bubbly mixture decreases substantially and could be as low as 20 m/s, and the mixture velocity can approach the speed of sound in the medium. In this numerical study, we extend our numerical model, which is based on the two-way coupling between the mixture flow field and Lagrangian tracking of a large number of bubbles, to accommodate compressible flow regimes. Numerical methods used and the validation studies for various flow conditions in the bubble augmented propulsor will be presented. This work is supported by Office of Naval Research through contract N00014-11-C-0482 monitored by Dr. Ki-Han Kim.

  17. 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. PMID:19118868

  18. 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.

  19. 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.

  20. 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.

  1. Sufficient Conditions for Efficient Classical Simulation of Quantum Optics

    NASA Astrophysics Data System (ADS)

    Rahimi-Keshari, Saleh; Ralph, Timothy C.; Caves, Carlton M.

    2016-04-01

    We provide general sufficient conditions for the efficient classical simulation of quantum-optics experiments that involve inputting states to a quantum process and making measurements at the output. The first condition is based on the negativity of phase-space quasiprobability distributions (PQDs) of the output state of the process and the output measurements; the second one is based on the negativity of PQDs of the input states, the output measurements, and the transition function associated with the process. We show that these conditions provide useful practical tools for investigating the effects of imperfections in implementations of boson sampling. In particular, we apply our formalism to boson-sampling experiments that use single-photon or spontaneous-parametric-down-conversion sources and on-off photodetectors. Considering simple models for loss and noise, we show that above some threshold for the probability of random counts in the photodetectors, these boson-sampling experiments are classically simulatable. We identify mode mismatching as the major source of error contributing to random counts and suggest that this is the chief challenge for implementations of boson sampling of interesting size.

  2. Clinical presentation and manual therapy for lower quadrant musculoskeletal conditions

    PubMed Central

    Courtney, Carol A; Clark, Jeffrey D; Duncombe, Alison M; O’Hearn, Michael A

    2011-01-01

    Chronic lower quadrant injuries constitute a significant percentage of the musculoskeletal cases seen by clinicians. While impairments may vary, pain is often the factor that compels the patient to seek medical attention. Traumatic injury from sport is one cause of progressive chronic joint pain, particularly in the lower quarter. Recent studies have demonstrated the presence of peripheral and central sensitization mechanisms in different lower quadrant pain syndromes, such as lumbar spine related leg pain, osteoarthritis of the knee, and following acute injuries such as lateral ankle sprain and anterior cruciate ligament rupture. Proper management of lower quarter conditions should include assessment of balance and gait as increasing pain and chronicity may lead to altered gait patterns and falls. In addition, quantitative sensory testing may provide insight into pain mechanisms which affect management and prognosis of musculoskeletal conditions. Studies have demonstrated analgesic effects and modulation of spinal excitability with use of manual therapy techniques, with clinical outcomes of improved gait and functional ability. This paper will discuss the evidence which supports the use of manual therapy for lower quarter musculoskeletal dysfunction. PMID:23115474

  3. Response of gonococcal clinical isolates to acidic conditions.

    PubMed

    Pettit, R K; McAllister, S C; Hamer, T A

    1999-02-01

    This study examined the response to acidic conditions of four gonococcal isolates -NRL38874 (Proto/IB-2), NRL38884 (Pro/IA-2), NRL38953 (Proto/IB-3) and NRL39029 (Pro/IA-3) - obtained from various sites in patients in whom a diagnosis of pelvic inflammatory disease had been made by laparoscopic examination. Acid tolerance of the clinical isolates was strain and growth phase dependent. Growth of the four strains on solid media was undetectable below pH 5.8. In liquid culture, strain NRL38884 did not survive below pH 5.2; strains NRL38874, NRL38953 and NRL39029 survived to pH 4.5. Between pH 4.2 and pH 5.1, the latter three strains exhibited a peak in survival at pH 4.6-4.7 during log phase, suggesting that there may be a distinct acid tolerance system operating at this pH. SDS-PAGE of whole-cell, total membrane and outer-membrane fractions of the four strains prepared from pH 7.2 and pH 6.1 plate cultures revealed numerous differences in protein composition. Acidic conditions reduced the expression of the reduction modifiable outer-membrane protein Rmp, and induced the expression of many membrane proteins, including gonococcal hsp63. Immunoblotting studies with matched serum samples and strains from patients with pelvic inflammatory disease indicated that IgG recognition of outer-membrane components from strains cultured in acidic and neutral conditions was quite different. The results suggest that the immune system interacts with unique outer-membrane constituents on gonococci colonising sites at different pH.

  4. Direct teaching of thinking skills using clinical simulation.

    PubMed

    Su, Whei Ming; Juestel, Marne J

    2010-01-01

    Because of the nursing faculty shortage, many academic leaders hire clinicians who are not formally prepared for an academic role. Novice faculty face an immediate need to develop teaching skills. One of the most crucial areas is the ability to help students develop critical thinking. To address this need, the authors describe how they used clinical simulation to incorporate direct teaching of thinking skills into course content and how this resulted in a faculty mentoring experience.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Inner Magnetosphere Simulations: Exploring Magnetosonic Wave Generation Conditions

    NASA Astrophysics Data System (ADS)

    Zaharia, S. G.; Jordanova, V. K.; MacDonald, E.; Thomsen, M. F.

    2012-12-01

    We investigate the conditions for magnetosonic wave generation in the near-Earth magnetosphere by performing numerical simulations with our newly improved self-consistent model, RAM-SCB. The magnetosonic (ion Bernstein) instability, a potential electron acceleration mechanism in the outer radiation belt, is driven by a positive slope in the ion distribution function perpendicular to the magnetic field, a so-called "velocity ring" distribution at energies above 1 keV. The formation of such distributions is dependent on the interplay of magnetic and electric drifts, as well as ring current losses, and therefore its study requires a realistic treatment of both plasma and field dynamics. The RAM-SCB model represents a 2-way coupling of the kinetic ring current-atmosphere interactions model (RAM) with a 3D plasma equilibrium code. In RAM-SCB the magnetic field is computed in force balance with the RAM anisotropic pressures and then returned to RAM to guide the particle dynamics. RAM-SCB thus properly treats both the kinetic drift physics crucial in the inner magnetosphere and the self-consistent interaction between plasma and magnetic field (required due to the strong field depressions during storms, depressions that strongly affect particle drifts). In order to provide output at geosynchronous locations, recently the RAM-SCB boundary has been expanded to 9 RE from Earth, with plasma pressure and magnetic field boundary conditions prescribed there from empirical models. This presentation will analyze, using event simulations with the improved model and comparisons with LANL MPA geosynchronous observations, the occurrence and location of magnetosonic unstable regions in the inner magnetosphere and their dependence on the following factors: 1). geomagnetic activity level (including quiet time, storm main phase and recovery); 2). magnetic field self-consistency (stretched vs. dipole fields). We will also discuss the physical mechanism for the occurrence of the velocity

  11. Bioprosthetic heart valve leaflet motion under simulated physiologic conditions

    NASA Astrophysics Data System (ADS)

    Zhi, Gao

    The application of current bioprosthetic heart valves is limited by the lack of valve durability. Valve failure is thought to be related to uneven stress distribution within the leaflet, which is associated with subtle aspects of leaflet motion, such as excessive bending and wrinkling, during valve opening and closing in a cardiac cycle. However, detailed descriptions of the valve motion, particularly leaflet deformation, are not available in the literature. To address this problem, new metrological methodology, based on optical imaging techniques, was developed to assess the leaflet motion of bioprosthetic heart valves under simulated physiologic conditions. To investigate the realistic leaflet motion, which is strongly linked to the fluid flow through the valve, a new hydrodynamic testing loop was built from modifications of an existing design. While the new loop retained the main characteristics of the old loop, which closely simulates physiologic conditions, the design of an optical window permitted visualization of the valve leaflet in dynamic motion. These sequences of leaflet motion obtained under such accurately simulated physiological waveforms, as depicted in this dissertation, have never been previously reported. By designing a unique triggering mechanism, dual-camera stereo photogrammetry was developed. Instead of using stereo photogrammetry to investigate static or quasi- static valve leaflet surface contours, dynamic sequences of the leaflet motion in a complete valve opening and closing cycle were retrieved. In addition, introduction of the double-pulse illumination technique took advantage of the field transfer mechanism of the CCD camera and captured two consecutive images within a short time. A sequence of leaflet deformation diagrams from this technique was reconstructed for the first time. Also, structured light photogrammetry, using the Fourier transform fringe analysis method, was developed. It featured nondestructive surface contour

  12. DNA damage under simulated extraterrestrial conditions in bacteriophage T7

    NASA Astrophysics Data System (ADS)

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

    The experiment "Phage and Uracil response" will be accommodated in the EXPOSE facility of the International Space Station. Its objective is to examine and quantify the effect of specific space conditions on nucleic acid models, especially on bacteriophage T7 and isolated T7 DNA thin films. In order to define the environmental and technical requirements of the EXPOSE, the samples were subjected to the experiment verification test (EVT). During EVT, the samples were exposed to vacuum (10 -4-10 -6 Pa) and polychromatic UV-radiation (200-400 nm) in air, in inert atmosphere, as well as in simulated space vacuum. The effect of extreme temperature in vacuum and the influence of temperature fluctuations around 0 °C were also studied. The total intraphage/isolated DNA damage was determined by quantitative PCR using 555 and 3826 bp fragments of T7 DNA. The type of the damage was resolved using a combination of enzymatic probes and neutral and alkaline agarose gel electrophoresis; the structural/chemical effects were analyzed by spectroscopic and microscopical methods. We obtained substantial evidence that DNA lesions accumulate throughout exposure, but the amount of damage depends on the thickness of the layers. According to our preliminary results, the damages by exposure to conditions of dehydration and UV-irradiation are larger than the sum of vacuum alone, or radiation alone case, suggesting a synergistic action of space vacuum and UV radiation with DNA being the critical target.

  13. Irreversible simulated tempering algorithm with skew detailed balance conditions: a learning method of weight factors in simulated tempering

    NASA Astrophysics Data System (ADS)

    Sakai, Yuji; Hukushima, Koji

    2016-09-01

    Recent numerical studies concerning simulated tempering algorithm without the detailed balance condition are reviewed and an irreversible simulated tempering algorithm based on the skew detailed balance condition is described. A method to estimate weight factors in simulated tempering by sequentially implementing the irreversible simulated tempering algorithm is studied in comparison with the conventional simulated tempering algorithm satisfying the detailed balance condition. It is found that the total amount of Monte Carlo steps for estimating the weight factors is successfully reduced by applying the proposed method to an two-dimensional ferromagnetic Ising model.

  14. 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.

  15. 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

  16. Comparing Burned and Unburned Forest Conditions Using Simulated Rill Experiments

    NASA Astrophysics Data System (ADS)

    Robichaud, P. R.; Brown, R. E.; Wagenbrenner, J. W.

    2007-12-01

    Despite the dominance of concentrated flow or rill erosion in the erosion processes in disturbed forests, few studies have quantified the effects of different types of forest disturbance on rill erosion. This study quantified the effects of four forest conditions--natural (recently undisturbed), low soil burn severity, high soil burn severity, and skid trails--on rill runoff quantity, runoff velocity, and rill erosion. Simulated rill experiments were conducted at sites in eastern Oregon (Tower Fire) and in northern Washington (North 25 Fire) on forested slopes with granitic and volcanic soils, respectively. The natural and skid trail conditions were established near each burned area in unburned forest. For each rill experiment, concentrated flow was applied at the top of the plot through an energy dissipater at five inflow rates for 12 min each. Runoff was sampled every 2 min and runoff volume and sediment concentration were determined for each sample. The runoff velocity was measured using a dyed calcium chloride solution and two conductivity probes placed a known distance apart. Runoff volume, runoff velocities, and sediment concentrations increased with increasing levels of disturbance. The natural plots had very low runoff rates and sediment concentrations at both the Tower and North 25 sites. The low soil burn severity plots had greater responses than the natural plots, but the responses in the two sites were different as a result of variability in effect of burning and differences in time between burning and the rill experiments. The high soil burn severity and the skid trail plots had the highest runoff ratios, runoff velocities, and sediment concentrations and the responses were similar at both sites. These results suggest that any differences in responses related to soil type or other site factors were masked by the increase in response resulting from the high levels of disturbance.

  17. Biological UV dosimeters in simulated space irradiation conditions

    NASA Astrophysics Data System (ADS)

    Rontó, G.; Bérces, A.; Fekete, A.; Kovács, G.; Lammer, H.

    For the measurement of the harmful biological effect of solar UV radiation bacteriophage T7 and polycrystalline uracil dosimeters were used. For terrestrial dosimetric purposes bacteriophage T7 has been applied in solution, while uracil in the form of thin layers. For space irradiation dosimetry the uracil, phage T7-DNA and bacteriophage T7 thin layer samples were prepared in vacuum tightly closed sandwich forms covered either by calciumfluoride or quartz windows. The experimental conditions tested correspond to the conditions planned in the EXPOSE facility: the samples were surrounded by nitrogen atmosphere at various humidities, their vacuum stability was tested in the vacuum chamber of the Institute of Space Research,, Graz. All kinds of the thin film samples have been stored in an atmosphere containing Nitrogen and Hidrogen, in quality control no change in the structure of them has been found. To attenuate the high extraterrestrial irradiance neutral filters of 0.5 and 1.0 optical densities have been tested. Irradiation of the samples has been performed with various UV sources: solar simulator, low pressure Mercury lamp, Deuterium lamp. Dose-effect functions have been determined using for the evaluation spectrophotometry in the characteristic UV range, HPLC of photoproducts, PCR of two different primer sequences of phage T7-DNA. Photoproduct formation kinetics was followed by the saturation level of uracil thin layer. Attenuation ability of the neutral filters was controlled with low pressure Mercury lamp by the exposure necessary for saturation of uracil dosimeters. A three and tenfold increase in the exposure was found respectively, while the influence of spectral composition of the irradiation source was tested using Deuterium lamp supplied with Ca F2 and quartz filters respectively. A doubling of the irradiance was necessary for the saturation of uracil with quartz filter.

  18. Structural performance of HEPA filters under simulated tornado conditions

    SciTech Connect

    Horak, H.L.; Gregory, W.S.; Ricketts, C.I.; Smith, P.R.

    1982-02-01

    This report contains the results of structural tests to determine the response of High Efficiency Particulate Air filters to simulated tornado conditions. The data include the structural limits of the filters, their resistance at high flow rates, and the effects of filter design features and tornado parameters. Considering all the filters tested, the mean break pressure or structural limit was found to be 2.35 pse (16.2 kPa). The maximum value was 2.87 psi (19.8 kPa), and the low value found was 1.31 psi (9.0 kPa). The type of failure was usually a medium break of the downstream filter fold. The type of filters that were evaluated were nuclear grade with design flow rates of 1000 cfm (0.472 m/sup 3//s), standard separators, and folded medium design. The parameters evaluated that are characteristic of the filter included manufacturer, separator type, faceguards, pack tightness, and aerosol loading. Manufacturer and medium properties were found to have a large effect on the structural limits.

  19. Ignition Conditions for Simulated Fuel Pellets in Degenerate Plasma

    NASA Astrophysics Data System (ADS)

    Mahdavi, M.; Gholami, A.

    2013-04-01

    A high-density, low-temperature plasma can be obtained during the compression phase in inertial confinement fusion. When high density and low temperature are reached in the plasma in the fast ignition approach, the plasma electrons can be degenerate. The electronic stopping of a slow ion is smaller than that given by the classical formula, because some transitions between the electron states are forbidden. In this case, bremsstrahlung emission is strongly suppressed and the ignition temperature becomes lower than that in classical plasma. The equations that predict the behavior of these plasmas are different from the classical ones, and this is the main factor in the process of decreasing the ignition temperature of the plasma. In this work, physical conditions of ignition are studied by calculating the effect of radiation loss on the ignition temperature for a simulated fuel pellet, (D/Tx/3Hey), in degenerate plasma. In fast ignition, the energy needed for obtaining high densities is minimized and the gain can be increased considerably.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Structural performance of HEPA filters under simulated tornado conditions

    NASA Astrophysics Data System (ADS)

    Horak, H. L.; Gregory, W. S.; Ricketts, C. I.; Smith, P. R.

    1982-02-01

    The response of high efficiency particulate air filters to simulated tornado conditions was determined. The data include the structural limits of the filters, their resistance at high flow rates, and the effects of filter design features and tornado parameters. Considering all the filters tested, the mean break pressure or structural limit was found to be 2.35 pse (16.2 kPa). The maximum value was 2.87 psi (19.8 kPa), and the low value found was 1.31 psi (9.0 kPa). The type of failure was usually a medium break of the downstream filter fold. The types of filters that were evaluated were nuclear grade with design flow rates of 1000 cfm (0.472 cu m/s), standard separators, and folded medium design. The parameters evaluated that are characteristic of the filter included manufacturer, separator type, face-guards, pack tightness, and aerosol loading. Manufacturer and medium properties were found to have a large effect on the structural limits.

  5. 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. PMID:22395307

  6. Clinical assessment of periodontal conditions in patients treated with nifedipine.

    PubMed

    Neumann, C; Willershausen-Zönnchen, B; Klug, C; Darius, H

    1996-03-19

    Calcium antagonists are widely used in treating acute and chronic coronary insufficiency disorders. A major side effect of long-term treatment is gingival hyperplasia. In the present study, 70 patients taking nifedipine for at least six months and 70 controls similar in age, gender, approximal hygiene and systemic disease with at least 6 anterior teeth in upper and lower arches were examined. Their periodontal conditions were determined by modified Sulcus-Bleeding-Index (mSBI), modified Approximal-Plaque-Index (mAPI), Community Periodontal Index of Treatment Needs (CPITN), a hyperplasia index quantifying the extent of gingival overgrowth, probing depths, clinical attachment loss and the modified Phenytoin-Gingival-Inflammation-Index (mPGI). A mild to moderate gingival hyperplasia was diagnosed in 21 of 70 patients resulting in a prevalence of 30% compared to 8.5% in controls. The hyperplastic changes were situated mainly in the anterior region of the dentition. Significant differences between both groups could be found comparing the severity of the gingival hyperplasia, the CPITN, mSBI, probing depths and the part of mPGI evaluating colour and turgor of the gingiva (p < 0.05). The severity of gingival overgrowth was strongly correlated with the inflammatory gingival changes, probing depths, the periodontal treatment need and the approximal hygiene of the patients. No statistically significant correlation could be found between the severity of gingival hyperplasia and the age and gender of the patient, or the dose or duration of nifedipine therapy. Gingival changes seemed to be more pronounced in patients with cardiovascular disorders than in patients under hemodialysis. The high incidence of gingival hyperplasia in patients receiving nifedipine on a long-term basis emphasises the role of the dentist and general practitioner in the early detection and prophylaxis of gingival changes and requires a thorough information to the patient concerning periodontal side

  7. 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.

  8. An R package for simulation experiments evaluating clinical trial designs.

    PubMed

    Wang, Yuanyuan; Day, Roger

    2010-01-01

    This paper presents an open-source application for evaluating competing clinical trial (CT) designs using simulations. The S4 system of classes and methods is utilized. Using object-oriented programming provides extensibility through careful, clear interface specification; using R, an open-source widely-used statistical language, makes the application extendible by the people who design CTs: biostatisticians. Four key classes define the specifications of the population models, CT designs, outcome models and evaluation criteria. Five key methods define the interfaces for generating patient baseline characteristics, stopping rule, assigning treatment, generating patient outcomes and calculating the criteria. Documentation of their connections with the user input screens, with the central simulation loop, and with each other faciliates the extensibility. New subclasses and instances of existing classes meeting these interfaces can integrate immediately into the application. To illustrate the application, we evaluate the effect of patient pharmacokinetic heterogeneity on the performance of a common Phase I "3+3" design. PMID:21347151

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

    PubMed

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

    2015-01-01

    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. PMID:25928758

  10. [Analysis and discussion on current condition of acupuncture clinical research registration].

    PubMed

    Xu, Ying; Chen, Bo; Guo, Yi

    2015-06-01

    To introduce the international registration condition of acupuncture clinical research. With the examples of World Health Organization International Clinical Trials Registry Platform and the U. S. National Institutes of Health Clinical Registration Platform, the registration method and current condition of acupuncture clinical trials in international clinical trials registration platform were analyzed. The results indicate that the number of acupuncture clinical trials registration is gradually increased and the registration number from China is on the rise as well. But most domestic acupuncture clinical researches haven't been registered arid the researchers' valuing degree for clinical trials registration and methodology research needs to be improved. PMID:26480568

  11. Heart rate, anxiety and performance of residents during a simulated critical clinical encounter: a pilot study

    PubMed Central

    2014-01-01

    Background High-fidelity patient simulation has been praised for its ability to recreate lifelike training conditions. The degree to which high fidelity simulation elicits acute emotional and physiologic stress among participants – and the influence of acute stress on clinical performance in the simulation setting – remain areas of active exploration. We examined the relationship between residents’ self-reported anxiety and a proxy of physiologic stress (heart rate) as well as their clinical performance in a simulation exam using a validated assessment of non-technical skills, the Ottawa Crisis Resource Management Global Rating Scale (Ottawa GRS). Methods This was a prospective observational cohort study of emergency medicine residents at a single academic center. Participants managed a simulated clinical encounter. Anxiety was assessed using a pre- and post-simulation survey, and continuous cardiac monitoring was performed on each participant during the scenario. Performance in the simulation scenario was graded by faculty raters using a critical actions checklist and the Ottawa GRS instrument. Results Data collection occurred during the 2011 academic year. Of 40 eligible residents, 34 were included in the analysis. The median baseline heart rate for participants was 70 beats per minute (IQR: 62 – 78). During the simulation, the median maximum heart rate was 140 beats per minute (IQR: 137 – 151). The median minimum heart rate during simulation was 81 beats per minute (IQR: 72 – 92), and mean heart rate was 117 beats per minute (95% CI: 111 – 123). Pre- and post-simulation anxiety scores were equal (mean 3.3, IQR: 3 to 4). The minimum and maximum Overall Ottawa GRS scores were 2.33 and 6.67, respectively. The median Overall score was 5.63 (IQR: 5.0 to 6.0). Of the candidate predictors of Overall performance in a multivariate logistic regression model, only PGY status showed statistical significance (P = 0.02). Conclusions Simulation is associated

  12. Using simulation to evaluate clinical competence after impairment.

    PubMed

    Raborn, G W; Carter, R M

    1999-01-01

    It is important for individual dentists and the profession to have access to a process for evaluating the clinical competence of practitioners who are professionally impaired as a result of an accident or a medical disability. No common standards for such evaluations currently exist, however, as demand for this type of assessment is still rare. This article reviews the evaluative approach taken by a team of experienced dental educators in examining three dentists who suffered from medical disabilities. An attempt was made to standardize the evaluation process by using clinical simulation to create an environment that would be comfortable for the dentists and acceptable to the lawyers and the insurance companies. Following evaluation, recommendations on individual competence were made, contributing to a faster resolution of legal and insurance issues.

  13. 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

  14. 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.

  15. Equivalence testing of traditional and simulated clinical experiences: undergraduate nursing students' knowledge acquisition.

    PubMed

    Schlairet, Maura C; Pollock, Jane W

    2010-01-01

    Although simulated clinical experience is being used increasingly in nursing education, vital evidence related to knowledge acquisition associated with simulated clinical experience does not exist. This intervention study used a 2×2 crossover design and equivalence testing to explore the effects of simulated clinical experiences on undergraduate students' (n = 74) knowledge acquisition in a fundamentals of nursing course. Following random assignment, students participated in laboratory-based simulated clinical experiences with high-fidelity human patient simulators and traditional clinical experiences and completed knowledge pretests and posttests. Analysis identified significant knowledge gain associated with both simulated and traditional clinical experiences, with the groups' knowledge scores being statistically significantly equivalent. A priori equivalence bounds around the difference between the groups were set at ± 5 points. Simulated clinical experience was found to be as effective as traditional clinical experience in promoting students' knowledge acquisition.

  16. 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. PMID:11761097

  17. 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

  18. Realistic modeling of clinical laboratory operation by computer simulation.

    PubMed

    Vogt, W; Braun, S L; Hanssmann, F; Liebl, F; Berchtold, G; Blaschke, H; Eckert, M; Hoffmann, G E; Klose, S

    1994-06-01

    An important objective of laboratory management is to adjust the laboratory's capability to the needs of patients' care as well as economy. The consequences of management may be changes in laboratory organization, equipment, or personnel planning. At present only one's individual experience can be used for making such decisions. We have investigated whether the techniques of operations research could be transferred to a clinical laboratory and whether an adequate simulation model of the laboratory could be realized. First we listed and documented the system design and the process flow for each single laboratory request. These input data were linked by the simulation model (programming language SIMSCRIPT II.5). The output data (turnaround times, utilization rates, and analysis of queue length) were validated by comparison with the current performance data obtained by tracking specimen flow. Congruence of the data was excellent (within +/- 4%). In planning experiments we could study the consequences of changes in order entry, staffing, and equipment on turnaround times, utilization, and queue lengths. We conclude that simulation can be a valuable tool for better management decisions.

  19. 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

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Condition: Laboratories performing high complexity testing; clinical consultant. The laboratory must have a... testing; clinical consultant. 493.1453 Section 493.1453 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION...

  1. Simulations of Stratospheric Aerosol Under Volcanic and Background Conditions

    NASA Astrophysics Data System (ADS)

    Weisenstein, D. K.; Ko, M. K.; Yue, G. K.; Jackman, C. H.; Fleming, E. L.

    2002-05-01

    The 17 year record of SAGE II aerosol observations has been extremely valuable to the understanding of stratospheric aerosols. This talk will focus on comparisons of the SAGE II version 6.1 aerosol observations with simulations from the AER 2-D sulfate aerosol model. Model simulations for the period from 1982 to 2002, including the eruptions of El Chichon, Ruiz, Kelut, Pinatubo, and Cerro Hudson, are performed with three different transport circulations, one from AER and two from GSFC. Decay rates from the simulated eruptions are compared with the SAGE II record and LIDAR observations from Hampton, Virginia. Since observed aerosol amounts are currently lower than any other period of SAGE II observations, we will compare the non-volcanic aerosol simulated by the models with the the low aerosol periods before and after the eruption of Mt. Pinatubo. Sensitivity to variations in the prescribed emissions of the source gases and to transport rates will be discussed.

  2. 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. PMID:26101029

  3. Monte Carlo simulation of photon way in clinical laser therapy

    NASA Astrophysics Data System (ADS)

    Ionita, Iulian; Voitcu, Gabriel

    2011-07-01

    The multiple scattering of light can increase efficiency of laser therapy of inflammatory diseases enlarging the treated area. The light absorption is essential for treatment while scattering dominates. Multiple scattering effects must be introduced using the Monte Carlo method for modeling light transport in tissue and finally to calculate the optical parameters. Diffuse reflectance measurements were made on high concentrated live leukocyte suspensions in similar conditions as in-vivo measurements. The results were compared with the values determined by MC calculations, and the latter have been adjusted to match the specified values of diffuse reflectance. The principal idea of MC simulations applied to absorption and scattering phenomena is to follow the optical path of a photon through the turbid medium. The concentrated live cell solution is a compromise between homogeneous layer as in MC model and light-live cell interaction as in-vivo experiments. In this way MC simulation allow us to compute the absorption coefficient. The values of optical parameters, derived from simulation by best fitting of measured reflectance, were used to determine the effective cross section. Thus we can compute the absorbed radiation dose at cellular level.

  4. 42 CFR 485.721 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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....

  5. 42 CFR 485.721 - Condition of participation: Clinical records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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....

  8. 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

  9. 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.

  10. 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

  11. Development and dissemination of Web-based clinical simulations for continuing geriatric nursing education.

    PubMed

    Kowlowitz, Vicki; Davenport, Carolyn S; Palmer, Mary H

    2009-04-01

    This article describes the process of developing and disseminating a Web-based library of geriatric clinical simulations used in continuing education workshops. Twenty-six peer-reviewed clinical simulations were developed on topics reflecting prevalent acute illnesses, conditions, or sentinel events that, if left undetected or untreated, could cause further comorbidity, hospitalization, or death. Geriatric nursing competencies identified by The John A. Hartford Foundation Institute for Geriatric Nursing were also incorporated. More than 700 workshop attendees and others have used these online clinical simulations. User evaluations of realism, accuracy of the situation or problem portrayed, and relevance to practice were rated as excellent or very good by more than 85% of the users. The University of North Carolina at Chapel Hill Center for Lifelong Learning Web site will offer this library with associated American Nurses Credentialing Center contact hours. This online access provides nurses high-quality continuing education offerings to increase knowledge and improve competence in the care of aging adults.

  12. 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,…

  13. 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…

  14. 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.

  15. [A Critical Condition of Clinical Studies in Japan -- A Battle of Clinical Study Groups].

    PubMed

    Furukawa, Hiroshi

    2016-04-01

    The post-marketing clinical study groups have been losing their activity due to stop of financial support. As the result, clinical study groups cannot achieve any EBM for treatment guidelines. Financial supports should be restarted immediately not to extinguish the post-marketing clinical studies and study groups. PMID:27220798

  16. 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.

  17. 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.

  18. Clinical simulation and workflow by use of two clinical information systems, the electronic health record and digital dictation.

    PubMed

    Koldby, Sven; Schou Jensen, Iben

    2013-01-01

    Clinical information systems do not always support clinician workflows. An increasing number of unintended clinical incidents might be related to implementation of clinical information systems and to a new registration praxis of unintended clinical incidents. Evidence of performing clinical simulations before implementation of new clinical information systems provides the basis for use of this method. The intention has been to evaluate patient safety issues, functionality, workflow, and usefulness of a new solution before implementation in the hospitals. Use of a solution which integrates digital dictation and the EHR (electronic health record) were simulated in realistic and controlled clinical environments. Useful information dealing with workflow and patient safety were obtained. The clinical simulation demonstrated that the EHR locks during use of the integration of digital dictation, thus making it impossible to use the EHR or connected applications during digital dictation. The results of the simulations showed that the tested and evaluated solution does not support the clinical workflow. Conducting the simulations enabled us to improve the solution before implementation, but further development is necessary before implementation of the solution.

  19. 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

  20. Boundary conditions and the simulation of low Mach number flows

    NASA Technical Reports Server (NTRS)

    Hagstrom, Thomas; Lorenz, Jens

    1993-01-01

    The problem of accurately computing low Mach number flows, with the specific intent of studying the interaction of sound waves with incompressible flow structures, such as concentrations of vorticity is considered. This is a multiple time (and/or space) scales problem, leading to various difficulties in the design of numerical methods. Concentration is on one of these difficulties - the development of boundary conditions at artificial boundaries which allow sound waves and vortices to radiate to the far field. Nonlinear model equations are derived based on assumptions about the scaling of the variables. Then these are linearized about a uniform flow and exact boundary conditions are systematically derived using transform methods. Finally, useful approximations to the exact conditions which are valid for small Mach number and small viscosity are computed.

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

    PubMed

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

    2009-04-01

    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 degrees 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.

  2. 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

  3. Acute acalculous cholecystitis simulating Mirizzi syndrome: a very rare condition.

    PubMed

    Ahlawat, Sushil K

    2009-02-01

    Mirizzi syndrome, a rare complication of chronic cholelithiasis, is caused by an impacted stone in the cystic duct or the neck of the gallbladder. Patients present with abdominal pain, fever, and obstructive jaundice. The cholangiographic finding is a smooth stricture caused by lateral compression of the common hepatic duct. A similar appearance on cholangiogram can result from carcinoma of the gallbladder, carcinoma of the cystic duct, or hilar adenopathy. Acute acalculous cholecystitis simulating Mirizzi syndrome is extremely rare. This is the report of such a case in which marked inflammatory changes around the neck of the gallbladder likely caused significant mechanical obstruction of the common hepatic duct. PMID:19139716

  4. 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)

  5. Dissolved carbon in extreme conditions characterized by first principles simulations

    NASA Astrophysics Data System (ADS)

    Pan, Ding; Galli, Giulia

    One key component to understanding carbon transport in the Earth interior is the determination of the molecular species formed when carbon bearing materials are dissolved in water at extreme conditions. We used first principles molecular dynamics to investigate oxidized carbon in water at high pressure (P) and high temperature (T), up to the conditions of the Earth's upper mantle. Contrary to popular geochemistry models assuming that CO2 is the major carbon species present in water, we found that most of the dissolved carbon at 10 GPa and 1000 K is in the form of solvated CO32- and HCO3-anions. We also found that ion pairing between alkali metal cations and CO32- or HCO3-anions is greatly affected by P-T conditions, decreasing with pressure along an isotherm. Our study shows that it is crucial to take into account the specific molecular structure of water under extreme conditions and the changes in hydrogen bonding occurring at high P and T, in order to predict chemical reactions in dissolved carbon. Our findings also shed light on possible reduction mechanisms of CO2 when it is geologically stored, depending on the availability of water. The work is supported by the Sloan Foundation through the Deep Carbon Observatory.

  6. 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...

  7. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conditioning test simulations. 86.162-03 Section 86.162-03 Protection of Environment ENVIRONMENTAL PROTECTION... ENGINES Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles and New Light-Duty... alternative air conditioning test simulations. (a) Upon petition from a manufacturer or upon the Agency's...

  8. 40 CFR 86.162-03 - Approval of alternative air conditioning test simulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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...

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

    NASA Astrophysics Data System (ADS)

    Gifford, Howard C.

    2016-03-01

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

  10. Dendritic brushes under good solvent conditions: a simulation study.

    PubMed

    Gergidis, Leonidas N; Kalogirou, Andreas; Vlahos, Costas

    2012-12-11

    The structural properties of polymer brushes, formed by dendron polymers up to the third generation, were studied by means of Brownian dynamics simulations for the macroscopic state of good solvent. The distributions of polymer units, of the free ends, of the dendrons centers of mass, and of the units of every dendritic generation and the radii of gyration necessary for the understanding of the internal stratification of brushes were calculated. Previous self-consistent field theory numerical simulations of first-generation dendritic brushes suggested that at high grafting densities two kinds of populations are evident, one of short dendrons having weakly extended spacers and another with tall dendrons having strongly stretched spacers. These Brownian dynamics calculations provided a more complicated picture of dendritic brushes, revealing different populations of short, tall, and in some cases intermediate height dendrons, depending on the dendron generation and spacer length. The scaling dependence of the height and the span of the dendritic brush on the grafting density and other parameters were found to be in good agreement with existing theoretical results for good solvents. PMID:23134236

  11. Ab initio simulations of MgO under extreme conditions

    NASA Astrophysics Data System (ADS)

    Cebulla, Daniel; Redmer, Ronald

    2014-04-01

    We determined the phase diagram of magnesium oxide with finite-temperature density functional theory molecular dynamics simulations up to temperatures and pressures as relevant for the deep interior of super-Earths and in rocky cores of giant planets such as Jupiter. The equation of state data, the Hugoniot, and a ramp compression curve are computed and compared to earlier results from diamond anvil cell and (decaying) shock wave experiments. In addition, the dynamical electrical conductivity and the reflectivity along the experimental Hugoniot curve are calculated in order to characterize electronic structure changes under compression. The structural properties of MgO are identified using pair correlation functions and self-diffusion coefficients. The solid-solid coexistence line is calculated by comparing the free enthalpies of the B1 and the B2 phase. The free energy of the solid phases is determined via thermodynamic relations using the ab initio simulation results and phonon calculations in the harmonic approximation. Our results indicate that the solid B2 phase of MgO does not occur in the interior of the Earth but may play an important role in super-Earths and in rocky planetary cores.

  12. 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.

  13. 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.

  14. 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.

  15. Comments on ``Use of conditional simulation in nuclear waste site performance assessment`` by Carol Gotway

    SciTech Connect

    Downing, D.J.

    1993-10-01

    This paper discusses Carol Gotway`s paper, ``The Use of Conditional Simulation in Nuclear Waste Site Performance Assessment.`` The paper centers on the use of conditional simulation and the use of geostatistical methods to simulate an entire field of values for subsequent use in a complex computer model. The issues of sampling designs for geostatistics, semivariogram estimation and anisotropy, turning bands method for random field generation, and estimation of the comulative distribution function are brought out.

  16. Making the Case for Simulation-Based Assessments to Overcome the Challenges in Evaluating Clinical Competency.

    PubMed

    Leigh, Gwen; Stueben, Frances; Harrington, Deedra; Hetherman, Stephen

    2016-05-13

    The use of simulation in nursing has increased substantially in the last few decades. Most schools of nursing have incorporated simulation into their curriculum but few are using simulation to evaluate clinical competency at the end of a semester or prior to graduation. Using simulation for such high stakes evaluation is somewhat novel to nursing. Educators are now being challenged to move simulation to the next level and use it as a tool for evaluating clinical competency. Can the use of simulation for high-stakes evaluation add to or improve our current evaluation methods? Using patient simulation for evaluation in contrast to a teaching modality has important differences that must be considered. This article discusses the difficulties of evaluating clinical competency, and makes the case for using simulation based assessment as a method of high stakes evaluation. Using simulation for high-stakes evaluation has the potential for significantly impacting nursing education.

  17. Oxidation behavior of Incoloy 800 under simulated supercritical water conditions

    NASA Astrophysics Data System (ADS)

    Fulger, M.; Ohai, D.; Mihalache, M.; Pantiru, M.; Malinovschi, V.

    2009-03-01

    For a correct design of supercritical water-cooled reactor (SCWR) components, data regarding the behavior of candidate materials in supercritical water are necessary. Corrosion has been identified as a critical problem because the high temperature and the oxidative nature of supercritical water may accelerate the corrosion kinetics. The goal of this paper is to investigate the oxidation behavior of Incoloy 800 exposed in autoclaves under supercritical water conditions for up to 1440 h. The exposure conditions (thermal deaerated water, temperatures of 723, 773, 823 and 873 K and a pressure of 25 MPa) have been selected as relevant for a supercritical power plant concept. To investigate the structural changes of the oxide films, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and electrochemical impedance spectroscopy (EIS) analyses were used. Results show changes in the oxides chemical composition, microstructure and thickness versus testing conditions (pressure, temperature and time). The oxide films are composed of two layers: an outer layer enriched in Fe oxide and an inner layer enriched in Cr and Ni oxides corresponding to small cavities supposedly due to internal oxidation.

  18. 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.

  19. 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

  20. Ophthalmology simulation for undergraduate and postgraduate clinical education.

    PubMed

    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

  1. 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

  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. PMID:26953299

  3. 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. PMID:23941951

  4. Microbial degradation of clomazone under simulated California rice field conditions.

    PubMed

    Tomco, Patrick L; Holstege, Dirk M; Zou, Wei; Tjeerdema, Ronald S

    2010-03-24

    Clomazone (trade names Cerano and Command) is a popular herbicide used on California rice fields to control aquatic weeds. Its physicochemical characteristics indicate that it will persist primarily in the water column, where microbial degradation may drive its environmental fate. The objectives were to determine microbial degradation rates and compare the metabolic products under aerobic and anaerobic conditions similar to those in California rice fields during the summer. Time-series samples were extracted and analyzed by LC/MS/MS. Metabolic profiling revealed the following clomazone-derived transitions: m/z 240 --> 125 (clomazone), m/z 242 --> 125 (ring-open clomazone), m/z 256 --> 125 (5-hydroxyclomazone), m/z 256 --> 141 (aromatic hydroxyclomazone), m/z 268 --> 125 (unknown metabolite), and m/z 272 --> 141 (4'5-dihydroxyclomazone). Results indicate an anaerobic half-life of 7.9 days, with ring-open clomazone reaching 67.4% of application at 38 days. Aerobically, clomazone degraded more slowly (t(1/2) = 47.3 days), forming mostly soil-bound residues. Thus, under summer conditions, clomazone is likely to dissipate rapidly from fields via anaerobic degradation.

  5. 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.

  6. 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.

  7. 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. PMID:19191539

  8. Effects of Simulated Functional Loading Conditions on Dentin, Composite, and Laminate Structures

    PubMed Central

    Walker, Mary P.; Teitelbaum, Heather K.; Eick, J. David; Williams, Karen B.

    2008-01-01

    Use of composite restorations continues to increase, tempered by more potential problems when placed in posterior dentition. Thus, it is essential to understand how these materials function under stress-bearing clinical conditions. Since mastication is difficult to replicate in the laboratory, cyclic loading is frequently used within in vitro evaluations but often employs traditional fatigue testing, which typically does not simulate occlusal loading because higher stresses and loading frequencies are used, so failure mechanisms may be different. The present investigation utilized relevant parameters (specimen size; loading frequency) to assess the effects of cyclic loading on flexural mechanical properties and fracture morphology of (coronal) dentin, composite, and dentin-adhesive-composite “laminate” structures. Incremental monitoring of flexural modulus on individual beams over 60,000 loading cycles revealed a gradual increase across materials; post-hoc comparisons indicated statistical significance only for 1 versus 60k cycles. Paired specimens were tested (one exposed to 60k loading cycles, one to static loading only), and comparisons of flexural modulus and strength showed statistically significantly higher values for cyclically-loaded specimens across materials, with no observable differences in fracture morphology. Localized reorganization of dentin collagen and polymer chains could have increased flexural modulus and strength during cyclic loading, which may have implications toward the life and failure mechanisms of clinical restorations and underlying tooth structure. PMID:18823019

  9. Behavior of trace metals in simulated gasification conditions

    SciTech Connect

    Benson, S.A.; Erickson, T.A.; Zygarlicke, C.J.

    1995-03-01

    The fate of trace metals is being investigated in two emerging coal gasification electric power-generating systems: integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC). Some of the trace metals in coal are considered air toxics when released into the atmosphere and can also cause the degradation of fuel cell efficiency as a result of contamination. The fate of trace metals during coal conversion in GCC and IGFC systems is closely tied to how the trace metals are associated in the coal and gasification conditions. Bench- and pilot-scale gasification experiments were performed using Illinois No. 6 coal to determine the partitioning of mercury, selenium, arsenic, nickel, cadmium, lead, and chromium into gas, liquid, and solid phases as a function of gasification conditions and coal composition. Entrained ash was collected from the small-scale reactor using a multicyclone and impinger sampling train. Coal analysis revealed arsenic, mercury, nickel, lead, and selenium to be primarily associated with pyrite. Chromium was associated primarily with clay minerals, and cadmium appeared to have mostly an organic association. The partitioning during gasification indicated that chromium, lead, and nickel were enriched in the small ash particulate fraction (less than 1.5 {mu}m), while arsenic, selenium, and mercury were depleted in the particulate and more enriched in the vapor-phase fraction (collected in the impingers). Oxygen contents were varied to represent both combustion and gasification systems. Most of the work was conducted at lower oxygen-to-carbon ratios. Lower oxygen-to-carbon ratios resulted in more reducing environments in the gasification system, which appeared to drive more mercury to the vapor phase. Under constant oxygen-to-carbon ratios, mercury, selenium, and cadmium showed increasing volatility with increasing reaction zone temperature.

  10. 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

  11. The Validity of Written Simulation Exercises for Assessing Clinical Skills in Legal Education.

    ERIC Educational Resources Information Center

    Alderman, Donald L.; And Others

    1981-01-01

    Four different groups of respondents completed a set of simulation exercises intended to reflect lawyering skills involved in client interviews. Results suggest the appropriateness of simulation exercises as measures of clinical skills in legal education and the effectiveness of clinical programs in promoting development of such skills in law…

  12. 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…

  13. 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…

  14. 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.

  15. 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.

  16. [Possible contributions of acupuncture in the teaching of clinical simulation in nursing].

    PubMed

    dos Santos, Mateus Casanova; Leite, Maria Cecília Lorea; Heck, Rita Maria

    2011-03-01

    This study situates the emerging discussion about the possibility of integration of knowledge from acupuncture as a contribution to the pedagogicalpractices of simulated clinical education of undergraduate nursing education. The reflective work emerged as an approach to the dissertation project "Study on the evaluation of trigger learning simulation - Morphofunctional Lab/College of Nursing/Universidade Federal de Pelotas". The integral relationship between man and nature developed in acupuncture emerges as a suggestion of discussions and a potential pedagogical toolfor the clinical simulation in nursing. In this reflection, results prove that there is a need to develop this educational resource aimed at expanding the teaching of clinical simulation in nursing.

  17. 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

  18. Debriefing with the OPT model of clinical reasoning during high fidelity patient simulation.

    PubMed

    Kuiper, RuthAnne; Heinrich, Carol; Matthias, April; Graham, Meki J; Bell-Kotwall, Lorna

    2008-01-01

    Evidenced-based educational practices propose simulation as a valuable teaching and learning strategy to promote situated cognition and clinical reasoning to teach nursing students how to solve problems. A project that uses a structured debriefing activity, the Outcome Present State-Test Model of clinical reasoning following high fidelity patient simulation, is described in this paper. The results of this project challenge faculty to create and manage patient simulation scenarios that coordinate with didactic content and clinical experiences to direct student learning for the best reinforcement of clinical reasoning outcomes. Considerations for the future include incorporating patient simulation activities as part of student evaluation and curriculum development. The arguments for using high fidelity patient simulation in the current educational environment has obvious short term benefits, however, the long term benefit of developing clinical expertise remains to be discovered.

  19. Hydrogen generation along simulated faults at coseismic slip conditions

    NASA Astrophysics Data System (ADS)

    Hirose, T.; Suzuki, K.

    2009-12-01

    Since the discovery of deep-sea hydrothermal vents in the late 1970s, the most ancient microbial ecosystems are considered to evolve at habitable environments in the vicinity of H2-rich hydrothermal fluids (e.g., Russell & Hall, 1997). In the modern ocean, the H2-rich hydrothermal fluids that are often observed along the slow-spreading Mid Ocean Ridges (MOR) are most likely to be provided by the ultramafic rock-water reaction (serpentinization) (e.g., Seyfried et al., 1979). However, such H2-rich fluids can be also found at the East Pacific Rise (EPR) where ultramafic rocks are not exposed. In this study, we hypothesized that the H2-rich fluids at the EPR are produced during the seismic events in basaltic rocks, and that the H2 generation associated with seismic faulting could contribute to sustaining the subsurface biological communities. In order to confirm above hypotheses, we performed laboratory friction experiments on gabbro, dunite and granite at a constant normal stress of 1.0 MPa, slip velocities, V, of 0.09~1.6 m/s (nearly coseismic slip rates) and displacements of more than 10 m using a rotary-shear apparatus. Slip on the simulated fault was conducted within a small pressure vessel that was filled with air. H2 gas released during experiments was measured by a micro gas chromatograph which was directly connected to the pressure vessel. The main findings of our preliminary experimental work are: (1) H2 gas could not be detected at V < 0.09 m/s, while it was detected and increased with slip velocities over 0.3 m/s for all rock types. The amount of H2 generation in granite samples at 0.6 m/s is more than 20 times higher than that of dunite and gabbro. (2) When a few drops of distilled water were added to the sliding surfaces, the H2 production was enhanced for all rock types. (3) When the wet dunite specimen was sheared at V of 1.3 m/s corresponding to a total mechanical work energy of ~4.5 kJ (calculated as shear stress multiplied by displacement), the H2

  20. 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.

  1. 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.

  2. 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.

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

    PubMed

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

    2016-01-01

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

  4. 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.

  5. 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.

  6. Water Retention of Extremophiles and Martian Soil Simulants Under Close to Martian Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Jänchen, J.; Bauermeister, A.; Feyh, N.; deVera, J.-P.

    2012-05-01

    We report data about interaction of moisture with soil simulants and extremophiles under Martian environmental conditions contributing on atmosphere/surface modelling and on effects determining the water inventory of the upper soil layer of Mars.

  7. 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...

  8. Using Simulated Sessions to Enhance Clinical Social Work Education

    ERIC Educational Resources Information Center

    Mooradian, John K.

    2008-01-01

    This article evaluates a learning method that used theatre students as family clients in an advanced social work practice course. Data from 47 advanced graduate students showed that observing peers conduct simulated sessions can be an effective and valued learning experience. Quantitative findings indicated that simulations are perceived to be…

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Computer-Based Simulation Systems and Role-Playing: An Effective Combination for Fostering Conditional Knowledge.

    ERIC Educational Resources Information Center

    Shlechter, Theodore M.; And Others

    1992-01-01

    Examines the effectiveness of SIMNET (Simulation Networking), a virtual reality training simulation system, combined with a program of role-playing activities for helping Army classes to master the conditional knowledge needed for successful field performance. The value of active forms of learning for promoting higher order cognitive thinking is…

  14. Thresholds of elicitation depend on induction conditions. Could low level exposure induce sub-clinical allergic states that are only elicited under the severe conditions of clinical diagnosis?

    PubMed

    Hostynek, Jurij J; Maibach, Howard I

    2004-11-01

    While numerous studies have examined dose/response relationships occurring in the experimental induction of contact allergic dermatitis, fewer have examined the effects of varying the doses of both induction and challenge. Recently published studies have however done this and they all show the same remarkable observation: the threshold of elicitation decreases as the doses used to induce the allergy increase. This has important implications. One is that it may be more complicated to determine clear threshold doses below which allergic responses are not seen. It is also proposed that normal exposure to weak allergens such as some fragrance materials may induce "sub-clinical" allergic states which will not be elicited under these same exposure conditions but which may become apparent under the more severe conditions of clinical diagnosis. This may explain why the prevalence of Patch test reactions to some fragrance materials is apparently increasing in the absence of any clearly documented "epidemic" of consumer complaints.

  15. 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.

  16. Numerical Simulation and Clinical Verification of the Minimally Invasive Repair of Pectus Excavatum

    PubMed Central

    Zhong, WeiHong; Ye, JinDuo; Liu, JiFu; Zhang, ChunQiu; Zhao, MeiJiao

    2014-01-01

    Objective: In this article we proposed a modeling method by building an assembled model to simulate the orthopedic process of minimally invasive surgery for pectus excavatum and got the clinical verification, which aims to provide some references for clinic diagnoses, treatment, and surgery planning. Methods: The anterior chest model of a 15-year-old patient was built based on his CT images; and his finite element model and the Nuss bar were created. Coupling of nodal displacement was used to connect bones with cartilages of the anterior chest. Turning the Nuss bar over is completed by rotating displacement of it. By comparing the numerical simulation outcomes with clinical surgery results, the numerical simulation results were verified Results: The orthopedic process of minimally invasive surgery of pectus excavatum was simulated by model construction and numerical analysis. The stress, displacement fields and distribution of the contact pressure between the Nuss bar and costal cartilages were analyzed. The relationship between correcting force and displacement was obtained. Compared with the of clinical results, the numerical simulation results were close to that of the actual clinical surgery in displacement field, and the final contact position of the Nuss bar and the costal cartilages. Conclusion: Compared with the rigid model, the assembled simulation model is in more conformity with the actual clinical practice. The larger curvature results in the maximum equivalent stress, which is the main reason for clinical pain. Soft tissues and muscles should be taken into account in the numerical simulation process. PMID:26312072

  17. Designed to fail: how computer simulation can detect fundamental flaws in clinic flow.

    PubMed

    Parks, Jennifer Kaye; Engblom, Patricia; Hamrock, Eric; Satjapot, Siriporn; Levin, Scott

    2011-01-01

    Discrete-event simulation can be used as an effective tool for healthcare administrators to "test" various operational decisions. The recent growth in hospital outpatient volumes and a constrained financial environment make discrete-event simulation a cost-effective way to diagnose inefficiency and create and test strategies for improvement. This study shows how discrete-event simulation was used in an adult medicine clinic within a large, tertiary care, academic medical center. Simulation creation steps are discussed, including information gathering, process mapping, data collection, model creation, and results. Results of the simulation indicated that system bottle-necks were present in the medication administration and check-out steps of the clinic process. The simulation predicted that matching resources to excessive demand at appropriate times for these bottleneck steps would reduce patients' mean time in the system (i.e., visit time) from 124.3 (s.d. +/- 65.7) minutes to 87.0 (s.d. +/- 36.4) minutes. Although other factors may affect real-world operations of a clinic, discrete-event simulation allows healthcare administrators and clinic operational decision makers to observe the effects of changing staffing and resource allocations on patient wait and throughput time. Discrete-event simulation is not a cure-all for clinic throughput problems, but can be a strong tool to provide evidentiary guidance for clinic operational redesign. PMID:21495531

  18. Designed to fail: how computer simulation can detect fundamental flaws in clinic flow.

    PubMed

    Parks, Jennifer Kaye; Engblom, Patricia; Hamrock, Eric; Satjapot, Siriporn; Levin, Scott

    2011-01-01

    Discrete-event simulation can be used as an effective tool for healthcare administrators to "test" various operational decisions. The recent growth in hospital outpatient volumes and a constrained financial environment make discrete-event simulation a cost-effective way to diagnose inefficiency and create and test strategies for improvement. This study shows how discrete-event simulation was used in an adult medicine clinic within a large, tertiary care, academic medical center. Simulation creation steps are discussed, including information gathering, process mapping, data collection, model creation, and results. Results of the simulation indicated that system bottle-necks were present in the medication administration and check-out steps of the clinic process. The simulation predicted that matching resources to excessive demand at appropriate times for these bottleneck steps would reduce patients' mean time in the system (i.e., visit time) from 124.3 (s.d. +/- 65.7) minutes to 87.0 (s.d. +/- 36.4) minutes. Although other factors may affect real-world operations of a clinic, discrete-event simulation allows healthcare administrators and clinic operational decision makers to observe the effects of changing staffing and resource allocations on patient wait and throughput time. Discrete-event simulation is not a cure-all for clinic throughput problems, but can be a strong tool to provide evidentiary guidance for clinic operational redesign.

  19. 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.

  20. [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.

  1. Myocardial ischemic conditioning: Physiological aspects and clinical applications in cardiac surgery.

    PubMed

    Bousselmi, Radhouane; Lebbi, Mohamed Anis; Ferjani, Mustapha

    2014-04-01

    Ischemia-reperfusion is a major determinant of myocardial impairment in patients undergoing cardiac surgery. The main goal of research in cardioprotection is to develop effective techniques to avoid ischemia-reperfusion lesions. Myocardial ischemic conditioning is a powerful endogenous cardioprotective phenomenon. First described in animals in 1986, myocardial ischemic conditioning consists of applying increased tolerance of the myocardium to sustained ischemia by exposing it to brief episodes of ischemia-reperfusion. Several studies have sought to demonstrate its effective cardioprotective action in humans and to understand its underlying mechanisms. Myocardial ischemic conditioning has two forms: ischemic preconditioning (IPC) when the conditioning stimulus is applied before the index ischemia and ischemic postconditioning when the conditioning stimulus is applied after it. The cardioprotective action of ischemic conditioning was reproduced by applying the ischemia-reperfusion stimulus to organs remote from the heart. This non-invasive manner of applying ischemic conditioning has led to its application in clinical settings. Clinical trials for the different forms of ischemic conditioning were mainly developed in cardiac surgery. Many studies suggest that this phenomenon can represent an interesting adjuvant to classical cardioprotection during on-pump cardiac surgery. Ischemic conditioning was also tested in interventional cardiology with interesting results. Finally, advances made in the understanding of mechanisms that underlie the cardioprotective action of ischemic conditioning have paved the way to a new form of myocardial conditioning which is pharmacological conditioning.

  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. Periodic boundary conditions for long-time nonequilibrium molecular dynamics simulations of incompressible flows

    NASA Astrophysics Data System (ADS)

    Dobson, Matthew

    2014-11-01

    This work presents a generalization of the Kraynik-Reinelt (KR) boundary conditions for nonequilibrium molecular dynamics simulations. In the simulation of steady, homogeneous flows with periodic boundary conditions, the simulation box deforms with the flow, and it is possible for image particles to become arbitrarily close, causing a breakdown in the simulation. The KR boundary conditions avoid this problem for planar elongational flow and general planar mixed flow [T. A. Hunt, S. Bernardi, and B. D. Todd, J. Chem. Phys. 133, 154116 (2010)] through careful choice of the initial simulation box and by periodically remapping the simulation box in a way that conserves image locations. In this work, the ideas are extended to a large class of three-dimensional flows by using multiple remappings for the simulation box. The simulation box geometry is no longer time-periodic (which was shown to be impossible for uniaxial and biaxial stretching flows in the original work by Kraynik and Reinelt [Int. J. Multiphase Flow 18, 1045 (1992)]. The presented algorithm applies to all flows with nondefective flow matrices, and in particular, to uniaxial and biaxial flows.

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:22458701

  8. 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.

  9. 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.

  10. 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

  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. 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.

  13. 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).

  14. Teaching medical students a clinical approach to altered mental status: simulation enhances traditional curriculum

    PubMed Central

    Sperling, Jeremy D.; Clark, Sunday; Kang, Yoon

    2013-01-01

    Introduction Simulation-based medical education (SBME) is increasingly being utilized for teaching clinical skills in undergraduate medical education. Studies have evaluated the impact of adding SBME to third- and fourth-year curriculum; however, very little research has assessed its efficacy for teaching clinical skills in pre-clerkship coursework. To measure the impact of a simulation exercise during a pre-clinical curriculum, a simulation session was added to a pre-clerkship course at our medical school where the clinical approach to altered mental status (AMS) is traditionally taught using a lecture and an interactive case-based session in a small group format. The objective was to measure simulation's impact on students’ knowledge acquisition, comfort, and perceived competence with regards to the AMS patient. Methods AMS simulation exercises were added to the lecture and small group case sessions in June 2010 and 2011. Simulation sessions consisted of two clinical cases using a high-fidelity full-body simulator followed by a faculty debriefing after each case. Student participation in a simulation session was voluntary. Students who did and did not participate in a simulation session completed a post-test to assess knowledge and a survey to understand comfort and perceived competence in their approach to AMS. Results A total of 154 students completed the post-test and survey and 65 (42%) attended a simulation session. Post-test scores were higher in students who attended a simulation session compared to those who did not (p<0.001). Students who participated in a simulation session were more comfortable in their overall approach to treating AMS patients (p=0.05). They were also more likely to state that they could articulate a differential diagnosis (p=0.03), know what initial diagnostic tests are needed (p=0.01), and understand what interventions are useful in the first few minutes (p=0.003). Students who participated in a simulation session were more likely

  15. Discrete effects on boundary conditions for the lattice Boltzmann equation in simulating microscale gas flows.

    PubMed

    Guo, Zhaoli; Shi, Baochang; Zhao, T S; Zheng, Chuguang

    2007-11-01

    The lattice Boltzmann equation (LBE) has shown its promise in the simulation of microscale gas flows. One of the critical issues with this advanced method is to specify suitable slip boundary conditions to ensure simulation accuracy. In this paper we study two widely used kinetic boundary conditions in the LBE: the combination of the bounce-back and specular-reflection scheme and the discrete Maxwell's scheme. We show that (i) both schemes are virtually equivalent in principle, and (ii) there exist discrete effects in both schemes. A strategy is then proposed to adjust the parameters in the two kinetic boundary conditions such that an accurate slip boundary condition can be implemented. The numerical results demonstrate that the corrected boundary conditions are robust and reliable.

  16. 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.

  17. 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

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

    PubMed

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

    2016-05-01

    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

  19. 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.

  20. Numerical simulations of the cavitation phenomena in a Francis turbine at deep part load conditions

    NASA Astrophysics Data System (ADS)

    Wack, J.; Riedelbauch, S.

    2015-12-01

    In recent years, the operating range of hydraulic machines has been more and more extended. As a consequence, the turbines are facing off-design conditions with highly complex flow phenomena like cavitation. In the present study, the occurrences of cavitating inter blade vortices at deep part load conditions in a Francis turbine are investigated using two-phase flow simulations. The numerical simulations require small time steps and fine meshes to reproduce the required flow characteristics and resolve the minimum pressure in the vortex core. Furthermore, the treatment of the outlet boundary condition is important, as this operating point is facing severe backflow in one diffusor channel in the draft tube. The simulation results indicate that the inter blade vortices can be reproduced.

  1. 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.

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  3. Teaching Clinical Reasoning and Problem-solving Skills Using Human Patient Simulation

    PubMed Central

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

    2011-01-01

    This paper discusses using human patient simulation (HPS) to expose students to complex dynamic patient cases that require clinical judgment, problem-solving skills, and teamwork skills for success. An example of an HPS exercise used to teach multifaceted clinical concepts in a therapeutics course also is provided. PMID:22171117

  4. 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.

  5. 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.

  6. 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.

  7. 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.

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

    PubMed

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

    2015-01-01

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

  9. Activity and stability of a complex bacterial soil community under simulated Martian conditions

    NASA Astrophysics Data System (ADS)

    Hansen, Aviaja Anna; Merrison, Jonathan; Nørnberg, Per; Aagaard Lomstein, Bente; Finster, Kai

    2005-04-01

    A simulation experiment with a complex bacterial soil community in a Mars simulation chamber was performed to determine the effect of Martian conditions on community activity, stability and survival. At three different depths in the soil core short-term effects of Martian conditions with and without ultraviolet (UV) exposure corresponding to 8 Martian Sol were compared. Community metabolic activities and functional diversity, measured as glucose respiration and versatility in substrate utilization, respectively, decreased after UV exposure, whereas they remained unaffected by Martian conditions without UV exposure. In contrast, the numbers of culturable bacteria and the genetic diversity were unaffected by the simulated Martian conditions both with and without UV exposure. The genetic diversity of the soil community and of the colonies grown on agar plates were evaluated by denaturant gradient gel electrophoresis (DGGE) on DNA extracts. Desiccation of the soil prior to experimentation affected the functional diversity by decreasing the versatility in substrate utilization. The natural dominance of endospores and Gram-positive bacteria in the investigated Mars-analogue soil may explain the limited effect of the Mars incubations on the survival and community structure. Our results suggest that UV radiation and desiccation are major selecting factors on bacterial functional diversity in terrestrial bacterial communities incubated under simulated Martian conditions. Furthermore, these results suggest that forward contamination of Mars is a matter of great concern in future space missions.

  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. 42 CFR 410.45 - Rural health clinic services: Scope and conditions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Rural health clinic services: Scope and conditions. 410.45 Section 410.45 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM SUPPLEMENTARY MEDICAL INSURANCE (SMI) BENEFITS Medical and Other...

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

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

    PubMed

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

    2016-06-01

    This study evaluated hospital readiness and interprofessional clinical reasoning in speech-language pathology and dietetics students following a simulation-based teaching package. Thirty-one students participated in two half-day simulation workshops. The training included orientation to the hospital setting, part-task skill learning and immersive simulated cases. Students completed workshop evaluation forms. They filled in a 10-question survey regarding confidence, knowledge and preparedness for working in a hospital environment before and immediately after the workshops. Students completed written 15-min clinical vignettes at 1 month prior to training, immediately prior to training and immediately after training. A marking rubric was devised to evaluate the responses to the clinical vignettes within a framework of interprofessional education. The simulation workshops were well received by all students. There was a significant increase in students' self-ratings of confidence, preparedness and knowledge following the study day (p < .001). There was a significant increase in student overall scores in clinical vignettes after training with the greatest increase in clinical reasoning (p < .001). Interprofessional simulation-based training has benefits in developing hospital readiness and clinical reasoning in allied health students. PMID:26803776

  14. 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.

  15. 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.

  16. 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.

  17. 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

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

    PubMed

    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

  19. 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

  20. Assessment of student competency in a simulated speech-language pathology clinical placement.

    PubMed

    Hill, Anne E; Davidson, Bronwyn J; McAllister, Sue; Wright, Judith; Theodoros, Deborah G

    2014-10-01

    Clinical education programs in speech-language pathology enable the transition of students' knowledge and skills from the classroom to the workplace. Simulated clinical learning experiences provide an opportunity to address the competency development of novice students. This study reports on the validation of an assessment tool designed to evaluate speech-language pathology students' performance in a simulated clinical placement. The Assessment of Foundation Clinical Skills (AFCS) was designed to link to concepts and content of COMPASS(®): Competency Assessment in Speech Pathology, a validated assessment of performance in the workplace. It incorporates units and elements of competency relevant to the placement. The validity of the AFCS was statistically investigated using Rasch analysis. Participants were 18 clinical educators and 130 speech-language pathology students undertaking the placement. Preliminary results support the validity of the AFCS as an assessment of foundation clinical skills of students in this simulated clinical placement. All units of competency and the majority of elements were relevant and representative of these skills. The use of a visual analogue scale which included a pre-Novice level to rate students' performance on units of competency was supported. This research provides guidance for development of quality assessments of performance in simulated placements.

  1. 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.

  2. Prediction of modeled velopharyngeal orifice areas during steady flow conditions and during aerodynamic simulation of voiceless stop consonants.

    PubMed

    Smith, B E; Weinberg, B

    1982-07-01

    Results of a small number of studies (Warren and DuBois, 1964; Lubker, 1969; Smith and Weinberg, 1980; Horii and Lang, 1981) have led to expression of divergent views concerning the accuracy of modeled velopharyngeal orifice area estimates obtained on the basis of hydrokinetic principles. In this work, the hydrokinetic equation (Warren and DuBois, 1964) was subjected to experimentation: (1) in which flow rates through a vocal tract model were not varied and (2) in which flow rates were varied to simulate pressure/flow events found during voiceless, stop consonant production. With consideration given to instrumental and procedural factors, results indicated that accurate estimates of modeled velopharyngeal orifice areas can be obtained during steady flow conditions and during alternating flow conditions when measurements are made at airflow peaks. Results were interpreted to provide strong support for clinical and research use of the hydrokinetic equation to predict velopharyngeal orifice areas during stop consonant production.

  3. Prediction of modeled velopharyngeal orifice areas during steady flow conditions and during aerodynamic simulation of voiceless stop consonants.

    PubMed

    Smith, B E; Weinberg, B

    1982-07-01

    Results of a small number of studies (Warren and DuBois, 1964; Lubker, 1969; Smith and Weinberg, 1980; Horii and Lang, 1981) have led to expression of divergent views concerning the accuracy of modeled velopharyngeal orifice area estimates obtained on the basis of hydrokinetic principles. In this work, the hydrokinetic equation (Warren and DuBois, 1964) was subjected to experimentation: (1) in which flow rates through a vocal tract model were not varied and (2) in which flow rates were varied to simulate pressure/flow events found during voiceless, stop consonant production. With consideration given to instrumental and procedural factors, results indicated that accurate estimates of modeled velopharyngeal orifice areas can be obtained during steady flow conditions and during alternating flow conditions when measurements are made at airflow peaks. Results were interpreted to provide strong support for clinical and research use of the hydrokinetic equation to predict velopharyngeal orifice areas during stop consonant production. PMID:6956460

  4. An intelligent interactive simulator of clinical reasoning in general surgery.

    PubMed Central

    Wang, S.; el Ayeb, B.; Echavé, V.; Preiss, B.

    1993-01-01

    We introduce an interactive computer environment for teaching in general surgery and for diagnostic assistance. The environment consists of a knowledge-based system coupled with an intelligent interface that allows users to acquire conceptual knowledge and clinical reasoning techniques. Knowledge is represented internally within a probabilistic framework and externally through a interface inspired by Concept Graphics. Given a set of symptoms, the internal knowledge framework computes the most probable set of diseases as well as best alternatives. The interface displays CGs illustrating the results and prompting essential facts of a medical situation or a process. The system is then ready to receive additional information or to suggest further investigation. Based on the new information, the system will narrow the solutions with increased belief coefficients. PMID:8130508

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

    PubMed Central

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

    2016-01-01

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

  6. Molecular Dynamic Simulation of Sodium in 7-Pin LMFBR Bundle Under Hypothetical Accident Conditions

    SciTech Connect

    Bottoni, Maurizio; Bottoni, Claudio; Scanu, John

    2006-07-01

    In the frame of safety analysis of liquid metal fast breeder reactors (LMFBRs) under hypothetical Unprotected Loss of Flow (ULOF) conditions two-phase flow of sodium is simulated in a 7-pin bundle, with hexagonal lattice. Molecular dynamics, with the application of the Direct Simulation Monte Carlo (DSMC) method, and a macroscopic model describing rewetting sequences due to the flow of a sodium liquid film along the pin surfaces, are applied to simulate the coolant in the bundle. The pin surfaces and the inner surface of the hexagonal canning are treated in the Monte Carlo simulation as diffusively reflecting surfaces. Collisions of sodium molecules are computed with the 'hard-sphere' model. With respect to previous work the following improvements of the computational code were made: i) The full bundle is simulated, thus allowing for asymmetries, like a skewed power distribution, to be accounted for; ii) A pin model calculates detailed temperature distributions in the pins, so that temperature boundary conditions are computed and not imposed; iii) Post processing visualisation of computed results was developed. An out of pile sodium boiling experiment run at the Nuclear Research Center of Karlsruhe, Germany, is simulated and conclusions are drawn about the applicability of the methodology in computer codes dedicated to breeder reactors safety analysis. (authors)

  7. 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.…

  8. Effect of simulated gastrointestinal conditions on biofilm formation by Salmonella 1,4,[5],12:i:-.

    PubMed

    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

  9. 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

  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. 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

    2016-07-01

    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.

  12. 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.

  13. 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...

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  15. Boundary Conditions for Dislocation Dynamics Simulations and Stage 0 of BCC Metals at Low Temperature

    SciTech Connect

    Tang, M; Kubin, L P

    2001-05-01

    In order to study the dislocation density evolution of body centered cubic (bcc) crystals at low temperature by dislocation dynamics (DD) simulations, we investigated carefully three different boundary conditions (BC) for DD, i.e., the quasi-free surface BC, the flux-balanced BC, and the periodic BC. The latter two BCs can account for the dislocation loss from the boundary of the finite simulation box. PBC can also eliminate the influence of surfaces and improve the line connectivity. We have found that the PBC provides a convenient and effective boundary condition for DD simulations and have applied it to the study of dislocation density evolution of bcc metals during stage 0 deformation at low temperature.

  16. Simulation-based education for building clinical teams

    PubMed Central

    Marshall, Stuart D; Flanagan, Brendan

    2010-01-01

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

  17. 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.

  18. Simulation Analysis of Certain Hydraulic Lifting Appliance under Different Working Conditions

    NASA Astrophysics Data System (ADS)

    Lei, Huang; Genfu, Yuan; Xuehui, Chen

    Being typical of mechanical and electronic hydraulics appliance, hydraulic lifting appliance has many working conditions due to its particularities. Properties of hydraulic system decide high efficiency, security as well as stability under different working conditions. Beginning with simulation analysis on hydraulic system of hydraulic lifting appliance under different working conditions, the essay analyzes a certain hydraulic system through which design references can be offered for optimizing hydraulic system properties via hydraulic system force and changes of torque. And then properties of hydraulic system can be improved and a hydraulic system with stable performance can be obtained.

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

    PubMed Central

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

    2015-01-01

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

  1. Pilot Program Using Medical Simulation in Clinical Decision-Making Training for Internal Medicine Interns

    PubMed Central

    Miloslavsky, Eli M.; Hayden, Emily M.; Currier, Paul F.; Mathai, Susan K.; Contreras-Valdes, Fernando; Gordon, James A.

    2012-01-01

    Background The use of high-fidelity medical simulation in cognitive skills training within internal medicine residency programs remains largely unexplored. Objective To design a pilot study to introduce clinical decision-making training using simulation into a large internal medicine residency program, explore the practicability of using junior and senior residents as facilitators, and examine the feasibility of using the program to improve interns' clinical skills. Methods Interns on outpatient rotations participated in a simulation curriculum on a voluntary basis. The curriculum consisted of 8 cases focusing on acute clinical scenarios encountered on the wards. One-hour sessions were offered twice monthly from August 2010 to February 2011. Internal medicine residents and simulation faculty served as facilitators. Results A total of 36 of 75 total interns volunteered to participate in the program, with 42% attending multiple sessions. Of all participants, 88% rated the sessions as “excellent,” 97% felt that the program improved their ability to function as an intern and generate a plan, and 81% reported improvement in differential diagnosis skills. Conclusions Simulation training was well received by the learners and improved self-reported clinical skills. Using residents as facilitators, supervised by faculty, was well received by the learners and enabled the implementation of the curriculum in a large training program. Simulation can provide opportunities for deliberate practice, and learners perceive this modality to be effective. PMID:24294427

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. Application of National Testing Standards to Simulation-Based Assessments of Clinical Palpation Skills

    PubMed Central

    Pugh, Carla M.

    2014-01-01

    With the advent of simulation technology, several types of data acquisition methods have been used to capture hands-on clinical performance. Motion sensors, pressure sensors, and tool-tip interaction software are a few of the broad categories of approaches that have been used in simulation-based assessments. The purpose of this article is to present a focused review of 3 sensor-enabled simulations that are currently being used for patient-centered assessments of clinical palpation skills. The first part of this article provides a review of technology components, capabilities, and metrics. The second part provides a detailed discussion regarding validity evidence and implications using the Standards for Educational and Psychological Testing as an organizational and evaluative framework. Special considerations are given to content domain and creation of clinical scenarios from a developer’s perspective. The broader relationship of this work to the science of touch is also considered. PMID:24084306

  8. 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.

  9. 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.

  10. Lessons Learned From Nocebo Effects in Clinical Trials for Pain Conditions and Neurodegenerative Disorders.

    PubMed

    Amanzio, Martina; Palermo, Sara; Skyt, Ina; Vase, Lene

    2016-10-01

    It has been demonstrated that patients in the placebo arm of a clinical trial may experience adverse events (AEs), which may lead to nonadherence and dropout. However, so far, it is unknown to which extent this phenomenon is observed consistently across different diseases such as pain and neurodegenerative disorders.The current review shows for the first time that different diseases share a common risk for patients in terms of a negative outcome: a large percentage of placebo-treated patients experience AEs in pain conditions (up to 59%) and neurodegenerative disorders (up to 66%). In addition, the rate of patients who discontinue because of AEs is up to 10% and 11% in pain conditions and neurodegenerative disorders, respectively.We highlight methodological shortcomings with the aim of suggesting how the detection and reporting of AEs can be improved in future trials. The insights from the current review should be taken into consideration when designing clinical trials to tailor individualized treatments. PMID:27580494

  11. 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.

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

    PubMed

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

    2010-05-01

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

  13. A Kinetic 13-Moment Boundary Conditions Method for Particle Simulations of Viscous Rarefied Flows

    NASA Astrophysics Data System (ADS)

    Averkin, Sergey; Gatsonis, Nikolaos

    2015-11-01

    The kinetic 13-moment (Navier-Stokes-Fourrier) boundary condition method is developed for direct simulation Monte Carlo (DSMC) simulations of rarefied gas flows. The particles are injected into the computational domain from the inlet and outlet following the first-order Chapman-Enskog distribution function. The unknown parameters of the Chapman-Enskog distribution function are reconstructed from the full 13-moment (Navier-Stokes-Fourier) equations discretized on the boundaries with the wave amplitudes calculated by the local one dimensional inviscid (LODI) formulation used in compressible (continuous) flow computations. The kinetic-moment boundary conditions are implemented in an unstructured 3D DSMC (U3DSMC) code and are supplemented with a neighboring-cell sampling approach and a time-average smoothing techniques to speed up convergence and reduce fluctuations. Simulations of a pressure-driven viscous subsonic flow in a circular tube are used for verification and validation of the boundary conditions. In addition, the present method is compared to the previously developed kinetic-moment boundary conditions derived from the five-moment (Euler) equations. AFOSR-FA9550-14-1-0366 Computational Mathematics Program.

  14. Evaluating clinical simulations for learning procedural skills: a theory-based approach.

    PubMed

    Kneebone, Roger

    2005-06-01

    Simulation-based learning is becoming widely established within medical education. It offers obvious benefits to novices learning invasive procedural skills, especially in a climate of decreasing clinical exposure. However, simulations are often accepted uncritically, with undue emphasis being placed on technological sophistication at the expense of theory-based design. The author proposes four key areas that underpin simulation-based learning, and summarizes the theoretical grounding for each. These are (1) gaining technical proficiency (psychomotor skills and learning theory, the importance of repeated practice and regular reinforcement), (2) the place of expert assistance (a Vygotskian interpretation of tutor support, where assistance is tailored to each learner's needs), (3) learning within a professional context (situated learning and contemporary apprenticeship theory), and (4) the affective component of learning (the effect of emotion on learning). The author then offers four criteria for critically evaluating new or existing simulations, based on the theoretical framework outlined above. These are: (1) Simulations should allow for sustained, deliberate practice within a safe environment, ensuring that recently-acquired skills are consolidated within a defined curriculum which assures regular reinforcement; (2) simulations should provide access to expert tutors when appropriate, ensuring that such support fades when no longer needed; (3) simulations should map onto real-life clinical experience, ensuring that learning supports the experience gained within communities of actual practice; and (4) simulation-based learning environments should provide a supportive, motivational, and learner-centered milieu which is conducive to learning.

  15. Physical properties of cross-linked polyethylene foam (Plastazote) under clinical conditions.

    PubMed

    Minns, R J; Craxford, A D

    1984-01-01

    Cross-linked polyethylene foam (Plastazote) has been used in the management of painful foot disorders occurring in a number of disease processes. A series of mechanical tests have been performed under varying clinically encountered conditions to show a relationship between the deformation of the material and the load applied to it. This has allowed the development of a method of assessment of the footprint impressed in a weight-bearing insole, and may help to clarify the observed results of treatment.

  16. Evaluation of a clinical simulation-based assessment method for EHR-platforms.

    PubMed

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

    2014-01-01

    In a procurement process assessment of issues like human factors and interaction between technology and end-users can be challenging. In a large public procurement of an Electronic health record-platform (EHR-platform) in Denmark a clinical simulation-based method for assessing and comparing human factor issues was developed and evaluated. This paper describes the evaluation of the method, its advantages and disadvantages. Our findings showed that clinical simulation is beneficial for assessing user satisfaction, usefulness and patient safety, all though it is resource demanding. The method made it possible to assess qualitative topics during the procurement and it provides an excellent ground for user involvement.

  17. Evaluation of a clinical simulation-based assessment method for EHR-platforms.

    PubMed

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

    2014-01-01

    In a procurement process assessment of issues like human factors and interaction between technology and end-users can be challenging. In a large public procurement of an Electronic health record-platform (EHR-platform) in Denmark a clinical simulation-based method for assessing and comparing human factor issues was developed and evaluated. This paper describes the evaluation of the method, its advantages and disadvantages. Our findings showed that clinical simulation is beneficial for assessing user satisfaction, usefulness and patient safety, all though it is resource demanding. The method made it possible to assess qualitative topics during the procurement and it provides an excellent ground for user involvement. PMID:25160323

  18. Use of Simulation to Study Nurses' Acceptance and Nonacceptance of Clinical Decision Support Suggestions.

    PubMed

    Sousa, Vanessa E C; Lopez, Karen Dunn; Febretti, Alessandro; Stifter, Janet; Yao, Yingwei; Johnson, Andrew; Wilkie, Diana J; Keenan, Gail M

    2015-10-01

    Our long-term goal was to ensure nurse clinical decision support works as intended before full deployment in clinical practice. As part of a broader effort, this pilot project explored factors influencing acceptance/nonacceptance of eight clinical decision support suggestions displayed in an electronic health record-based nursing plan of care software prototype. A diverse sample of 21 nurses participated in this high-fidelity clinical simulation experience and completed a questionnaire to assess reasons for accepting/not accepting the clinical decision support suggestions. Of 168 total suggestions displayed during the experiment (eight for each of the 21 nurses), 123 (73.2%) were accepted, and 45 (26.8%) were not accepted. The mode number of acceptances by nurses was seven of eight, with only two of 21 nurses accepting all. The main reason for clinical decision support acceptance was the nurse's belief that the suggestions were good for the patient (100%), with other features providing secondary reinforcement. Reasons for nonacceptance were less clear, with fewer than half of the subjects indicating low confidence in the evidence. This study provides preliminary evidence that high-quality simulation and targeted questionnaires about specific clinical decision support selections offer a cost-effective means for testing before full deployment in clinical practice. PMID:26361268

  19. The Effect of Nursing Faculty Presence on Students' Level of Anxiety, Self-Confidence, and Clinical Performance during a Clinical Simulation Experience

    ERIC Educational Resources Information Center

    Horsley, Trisha Leann

    2012-01-01

    Nursing schools design their clinical simulation labs based upon faculty's perception of the optimal environment to meet the students' learning needs, other programs' success with integrating high-tech clinical simulation, and the funds available. No research has been conducted on nursing faculty presence during a summative…

  20. 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.

  1. 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.

  2. 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

    The recognition of the need to make laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressure which correspond to the altitudes probed by radio occultation experiments, and over a range of frequencies which correspond to both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. Construction was completed of the outer planets simulator and measurements were conducted of the microwave absorption and refraction from nitrogen under simulated Titan conditions. The results of these and previous laboratory measurements were applied to a wide range of microwave opacity measurements, in order to derive constituent densities and distributions in planetary atmospheres such as Venus.

  3. 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.

  4. Wind Conditions in Idealized Building Clusters: Macroscopic Simulations Using a Porous Turbulence Model

    NASA Astrophysics Data System (ADS)

    Hang, Jian; Li, Yuguo

    2010-07-01

    Simulating turbulent flows in a city of many thousands of buildings using general high-resolution microscopic simulations requires a grid number that is beyond present computer resources. We thus regard a city as porous media and divide the whole hybrid domain into a porous city region and a clear fluid region, which are represented by a macroscopic k-{\\varepsilon} model. Some microscopic information is neglected by the volume-averaging technique in the porous city to reduce the calculation load. A single domain approach is used to account for the interface conditions. We investigated the turbulent airflow through aligned cube arrays (with 7, 14 or 21 rows). The building height H, the street width W, and the building width B are the same (0.15 m), and the fraction of the volume occupied by fluid (i.e. the porosity) is 0.75; the approaching flow is parallel to the main streets. There are both microscopic and macroscopic simulations, with microscopic simulations being well validated by experimental data. We analysed microscopic wind conditions and the ventilation capacity in such cube arrays, and then calculated macroscopic time-averaged properties to provide a comparison for macroscopic simulations. We found that the macroscopic k-{\\varepsilon} turbulence model predicted the macroscopic flow reduction through porous cube clusters relatively well, but under-predicted the macroscopic turbulent kinetic energy (TKE) near the windward edge of the porous region. For a sufficiently long porous cube array, macroscopic flow quantities maintain constant conditions in a fully developed region.

  5. 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

  6. 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

  7. Study on extreme turbulence wind conditions of multibody dynamics simulation for MW-class wind turbine

    NASA Astrophysics Data System (ADS)

    Wu, P.; Li, C.; Ye, Z.

    2013-12-01

    Parametric modeling of NREL 5MW wind turbine was set up for multi-body dynamics simulation by the TurbSim, AeroDyn, FAST (fatigue, aerodynamics, structures, and turbulence) software respectively. According to the analysis of the characteristics of wind in the space discrete point, using TurbSim to establish the steady-state wind and random changes with time and space wind. Based on the AeroDyn software, which can coupled to FAST, we calculated the aerodynamic load. Loading the aerodynamic data which has been calculated, FAST can establish a fully parameterized simulation model. Making a comparison of the results obtained by FAST in 3 different wind conditions, the different of dynamic responses of the structure were obtained. The results obtained by FAST have some meaning in the study of wind turbine under extreme turbulence wind conditions.

  8. 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

  9. Modelling and numerical simulation of the human aortic arch under in vivo conditions.

    PubMed

    García-Herrera, Claudio M; Celentano, Diego J

    2013-11-01

    This work presents the modelling and simulation of the mechanical behaviour of the human aortic arch under in vivo conditions with pressure levels within the normal and hypertension physiological range. The cases studied correspond to young and aged arteries without cardiovascular pathologies. First, the tissue of these two groups is characterised via in vitro tensile test measurements that make it possible to derive the material parameters of a hyperelastic isotropic constitutive model. Then, these material parameters are used in the simulation of young and aged aortic arches subjected to in vivo normal and hypertension conditions. Overall, the numerical results were found not only to provide a realistic description of the mechanical behaviour of the vessel but also to be useful data that allow the adequate definition of stress/stretch-based criteria to predict its failure.

  10. 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.

  11. 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.

  12. 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.

  13. Pellagra-like condition is xeroderma pigmentosum/Cockayne syndrome complex and niacin confers clinical benefit.

    PubMed

    Hijazi, H; Salih, M A; Hamad, M H A; Hassan, H H; Salih, S B M; Mohamed, K A; Mukhtar, M M; Karrar, Z A; Ansari, S; Ibrahim, N; Alkuraya, F S

    2015-01-01

    An extremely rare pellagra-like condition has been described, which was partially responsive to niacin and associated with a multisystem involvement. The condition was proposed to represent a novel autosomal recessive entity but the underlying mutation remained unknown for almost three decades. The objective of this study was to identify the causal mutation in the pellagra-like condition and investigate the mechanism by which niacin confers clinical benefit. Autozygosity mapping and exome sequencing were used to identify the causal mutation, and comet assay on patient fibroblasts before and after niacin treatment to assess its effect on DNA damage. We identified a single disease locus that harbors a novel mutation in ERCC5, thus confirming that the condition is in fact xeroderma pigmentosum/Cockayne syndrome (XP/CS) complex. Importantly, we also show that the previously described dermatological response to niacin is consistent with a dramatic protective effect against ultraviolet-induced DNA damage in patient fibroblasts conferred by niacin treatment. Our findings show the power of exome sequencing in reassigning previously described novel clinical entities, and suggest a mechanism for the dermatological response to niacin in patients with XP/CS complex. This raises interesting possibilities about the potential therapeutic use of niacin in XP.

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

    NASA Astrophysics Data System (ADS)

    Wagner, Christian; Verde, Licia

    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.

  15. 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.

  16. 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.

  17. Experimental simulation of the condensation and metamorphism of seasonal CO2 condensates under martian conditions.

    NASA Astrophysics Data System (ADS)

    Grisolle, F.; Schmitt, B.; Beck, P.; Philippe, S.; Brissaud, O.

    2014-04-01

    An experimental set-up, CARBON-IR, has been developed in order to perform the condensation and metamorphism of CO2 condensates in various controlled martian conditions at, or out of, equilibrium. The sample texture is monitored and near-infrared reflectance spectra are recorded. We present a first set of experiments aimed to simulate the formation of compact translucent slabs by condensation of CO2 gas, the metamorphism of CO2 snow, as well as their sublimation.

  18. 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.

  19. 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.

  20. [Main manifestations of the phenomenon of remote post-conditioning of the heart. Clinical application of post-conditioning].

    PubMed

    Maslov, L N

    2016-01-01

    It was determined that remote post-conditioning (RP) exerts infarction-limiting and antiapoptotic effects. The infarction-limiting effect of RP is associated with enhancement of autophagia of cardiomyocytes. It was determined that RP may be an effective method of preventing reperfusion contractile dysfunction of the heart. The problem of whether RP exerts an antiarrhythmic effect in cardiac ischaemia-reperfusion remains unsolved as yet. Limitation of leukocytic invasion may have direct relation to the cardioprotector effect of RP. Decreasing the level of anti-inflammatory cytokines and MCP-1 chemokine may contribute to limitation of leukocytic infiltration into the reperfusion zone. It was determined that RP provides a decrease in intensity of lipid peroxidation. Remote postconditioning prevents reperfusion damage to cardiomyocytes both in children and adults, but RP does not improve the clinical course of the postoperative period in patients with coronary bypass grafting. In children, RP improves the course of the postoperative period. What is the reason of such difference between children and adults remains unknown. It was shown that RP exerts an infarction-limiting effect in transcutaneous coronary interventions in patients with ST elevation myocardial infarction. PMID:27626245

  1. Numerical simulation of electrocardiograms for full cardiac cycles in healthy and pathological conditions.

    PubMed

    Schenone, Elisa; Collin, Annabelle; Gerbeau, Jean-Frédéric

    2016-05-01

    This work is dedicated to the simulation of full cycles of the electrical activity of the heart and the corresponding body surface potential. The model is based on a realistic torso and heart anatomy, including ventricles and atria. One of the specificities of our approach is to model the atria as a surface, which is the kind of data typically provided by medical imaging for thin volumes. The bidomain equations are considered in their usual formulation in the ventricles, and in a surface formulation on the atria. Two ionic models are used: the Courtemanche-Ramirez-Nattel model on the atria and the 'minimal model for human ventricular action potentials' by Bueno-Orovio, Cherry, and Fenton in the ventricles. The heart is weakly coupled to the torso by a Robin boundary condition based on a resistor-capacitor transmission condition. Various electrocardiograms (ECGs) are simulated in healthy and pathological conditions (left and right bundle branch blocks, Bachmann's bundle block, and Wolff-Parkinson-White syndrome). To assess the numerical ECGs, we use several qualitative and quantitative criteria found in the medical literature. Our simulator can also be used to generate the signals measured by a vest of electrodes. This capability is illustrated at the end of the article. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26249327

  2. Numerical simulation of turbulence and sand-bed morphodynamics in natural waterways under live bed conditions

    NASA Astrophysics Data System (ADS)

    Khosronejad, Ali; Sotiropoulos, Fotis

    2012-11-01

    We develop and validate a 3D numerical model for coupled simulations of turbulence and sand-bed morphodynamics in natural waterways under live bed conditions. We employ the Fluid-Structure Interaction Curvilinear Immersed Boundary (FSI-CURVIB) method of Khosronejad et al. (Adv. in Water Res., 2011). The mobile channel bed is discretized with an unstructured triangular grid and treated as the sharp-interface immersed boundary embedded in a background curvilinear mesh. Transport of bed load and suspended load sediments are combined in the non-equilibrium from of the Exner-Poyla for the bed surface elevation, which evolves due to the spatio-temporally varying bed shear stress and velocity vector induced by the turbulent flow field. Both URANS and LES models are implemented to simulate the effects of turbulence. Simulations are carried out for a wide range of waterways, from small scale streams to large-scale rivers, and the simulated sand-waves are quantitatively compared to available measurements. It is shown that the model can accurately capture sand-wave formation, growth, and migration processes observed in nature. The simulated bed-forms are found to have amplitude and wave length scales ranging from the order of centimeters up to several meters. This work was supported by NSF Grants EAR-0120914 and EAR-0738726, and National Cooperative Highway Research Program Grant NCHRP-HR 24-33. Computational resources were provided by the University of Minnesota Supercomputing Institute.

  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. 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

  5. Computer-Simulated Psychotherapy as an Aid in Teaching Clinical Psychology.

    ERIC Educational Resources Information Center

    Suler, John R.

    1987-01-01

    Describes how Elisa, a widely known computer program which simulates the responses of a psychotherapist, can be used as a teaching aid in undergraduate clinical psychology classes. Provides information on conducting the exercise, integrating it into the course syllabus, and evaluating its impact on students. (JDH)

  6. A Comprehensive, Simulation-Based Approach to Teaching Clinical Skills: The Medical Students’ Perspective

    PubMed Central

    Evans, Leigh V.; Crimmins, Ashley C.; Bonz, James W.; Gusberg, Richard J.; Tsyrulnik, Alina; Dziura, James D.; Dodge, Kelly L.

    2014-01-01

    The purpose of this study was to determine if third-year medical students participating in a mandatory 12-week simulation course perceived improvement in decision-making, communication, and teamwork skills. Students participated in or observed 24 acute emergency scenarios. At 4-week intervals, students completed 0-10 point Likert scale questionnaires evaluating the curriculum and role of team leader. Linear contrasts were used to examine changes in outcomes. P-values were Bonferroni-corrected for multiple pairwise comparisons. Student evaluations (n = 96) demonstrated increases from week 4 to 12 in educational value (p = 0.006), decision-making (p < 0.001), communication (p = 0.02), teamwork (p = 0.01), confidence in management (p < 0.001), and translation to clinical experience (p < 0.001). Regarding the team leader role, students reported a decrease in stress (p = 0.001) and increase in ability to facilitate team function (p < 0.001) and awareness of team building (p = <0.001). Ratings demonstrate a positive impact of simulation on both clinical management skills and team leadership skills. A simulation curriculum can enhance the ability to manage acute clinical problems and translates well to the clinical experience. These positive perceptions increase as the exposure to simulation increases. PMID:25506290

  7. Instant Experience in Clinical Trials: A Computer-Aided Simulation Technique

    ERIC Educational Resources Information Center

    Simpson, Michael A.

    1976-01-01

    Describes "Instant Experience," a simulation and game method in which students are given information about a promising new drug and asked to design a protocol for a clinical trial of the drug. Evaluation of a trial workshop showed positive response to the method. Educational goals to be achieved through its use are noted. (JT)

  8. Assessment of the Impact of Integrated Simulation on Critical Thinking and Clinical Judgment in Nursing Instruction

    ERIC Educational Resources Information Center

    Meyer, Rita Allen

    2012-01-01

    The purpose of this study was to explore the effects of using simulation and didactic instruction on critical thinking and clinical judgment with student nurses enrolled in a fall semester medical-surgical class. Specifically, it was of interest to compare the performance of these fall semester nursing students with the performance of nursing…

  9. A comprehensive, simulation-based approach to teaching clinical skills: the medical students' perspective.

    PubMed

    Evans, Leigh V; Crimmins, Ashley C; Bonz, James W; Gusberg, Richard J; Tsyrulnik, Alina; Dziura, James D; Dodge, Kelly L

    2014-12-01

    The purpose of this study was to determine if third-year medical students participating in a mandatory 12-week simulation course perceived improvement in decision-making, communication, and teamwork skills. Students participated in or observed 24 acute emergency scenarios. At 4-week intervals, students completed 0-10 point Likert scale questionnaires evaluating the curriculum and role of team leader. Linear contrasts were used to examine changes in outcomes. P-values were Bonferroni-corrected for multiple pairwise comparisons. Student evaluations (n = 96) demonstrated increases from week 4 to 12 in educational value (p = 0.006), decision-making (p < 0.001), communication (p = 0.02), teamwork (p = 0.01), confidence in management (p < 0.001), and translation to clinical experience (p < 0.001). Regarding the team leader role, students reported a decrease in stress (p = 0.001) and increase in ability to facilitate team function (p < 0.001) and awareness of team building (p = <0.001). Ratings demonstrate a positive impact of simulation on both clinical management skills and team leadership skills. A simulation curriculum can enhance the ability to manage acute clinical problems and translates well to the clinical experience. These positive perceptions increase as the exposure to simulation increases. PMID:25506290

  10. Human Patient Simulations: Evaluation of Self-Efficacy and Anxiety in Clinical Skills Performance

    ERIC Educational Resources Information Center

    Onovo, Grace N.

    2013-01-01

    The relationship between self-efficacy (self-confidence) and anxiety levels, and the use of Human Patient Simulations (HPS) as a teaching-learning strategy, has not been sufficiently studied in the area of clinical nursing education. Despite the evidence in the literature indicating that HPS increases self-efficacy/self-confidence and decreases…

  11. The Impact of Initial Conditions in N-Body Simulations of Debris Discs

    NASA Astrophysics Data System (ADS)

    Thilliez, E.; Maddison, S. T.

    2015-10-01

    Numerical simulations are a crucial tool to understand the relationship between debris discs and planetary companions. As debris disc observations are now reaching unprecedented levels of precision over a wide range of wavelengths, an appropriate level of accuracy and consistency is required in numerical simulations to confidently interpret this new generation of observations. However, simulations throughout the literature have been conducted with various initial conditions often with little or no justification. In this paper, we aim to study the dependence on the initial conditions of N-body simulations modelling the interaction between a massive and eccentric planet on an exterior debris disc. To achieve this, we first classify three broad approaches used in the literature and provide some physical context for when each category should be used. We then run a series of N-body simulations, that include radiation forces acting on small grains, with varying initial conditions across the three categories. We test the influence of the initial parent body belt width, eccentricity, and alignment with the planet on the resulting debris disc structure and compare the final peak emission location, disc width and offset of synthetic disc images produced with a radiative transfer code. We also track the evolution of the forced eccentricity of the dust grains induced by the planet, as well as resonance dust trapping. We find that an initially broad parent body belt always results in a broader debris disc than an initially narrow parent body belt. While simulations with a parent body belt with low initial eccentricity (e ~ 0) and high initial eccentricity (0 < e < 0.3) resulted in similar broad discs, we find that purely secular forced initial conditions, where the initial disc eccentricity is set to the forced value and the disc is aligned with the planet, always result in a narrower disc. We conclude that broad debris discs can be modelled by using either a dynamically cold

  12. A1B scenario simulations of future natural snow conditions in Tyrol and Styria (Austrian Alps)

    NASA Astrophysics Data System (ADS)

    Strasser, U.; Marke, T.; Hanzer, F.; Ragg, H.; Kleindienst, H.; Wilcke, R.; Gobiet, A.

    2012-04-01

    We use four different realizations of the IPCC A1B emission scenario based climate simulations provided by the ENSEMBLES project for the study regions Tyrol and Styria. They represent average as well as above average cold/warm and wet/dry conditions in the winter half year (November to April). The scenario and control run simulations were downscaled and error corrected to station locations with a quantile based empirical-statistical method on a daily time basis. To provide 3-hourly meteorological snow model input data, diurnal variations have been extracted from uncorrected RCM simulations to disaggregate the downscaled and bias corrected daily data. The resulting time series of meteorological parameters are spatially interpolated on the basis of existing parameter-elevation relations, and by means of a kriging technique. The control simulations (1971-2000) and scenario simulations (2021-2050) are applied as meteorological forcing for two snow models: The process based snow model AMUNDSEN includes physical descriptions of all snow relevant surface processes, is therefore transferable in space and time, and provides results at high spatial resolution (50 m). Due to its computational demands its application is limited to the two test regions Kitzbuehel (Tyrol) and Schladming (Styria). To establish a regional snow simulation, the conceptual model SNOWREG is used. The temperature-index-approach requires only few input variables, is efficient in terms of computational costs and allows a large-scale application for the provinces of Tyrol and Styria at a spatial resolution of 250 m. SNOWREG is trained by means of assimilating natural snow cover patterns provided by remotely sensed snow coverage and station recordings. Indicators for skiing conditions are used to quantify and compare changes in future natural snow conditions. The moderate increase in average area mean winter temperature (up to 2,6 °C in Tyrol and 2.3 °C in Styria) and changes in area mean winter

  13. Clinical compliance of viewing conditions in radiology reporting environments against current guidelines and standards

    NASA Astrophysics Data System (ADS)

    Daly, S.; Rainford, L.; Butler, M. L.

    2014-03-01

    Several studies have demonstrated the importance of environmental conditions in the radiology reporting environment, with many indicating that incorrect parameters could lead to error and misinterpretation. Literature is available with recommendations as to the levels that should be achieved in clinical practice, but evidence of adherence to these guidelines in radiology reporting environments is absent. This study audited the reporting environments of four teleradiologist and eight hospital based radiology reporting areas. This audit aimed to quantify adherence to guidelines and identify differences in the locations with respect to layout and design, monitor distance and angle as well as the ambient factors of the reporting environments. In line with international recommendations, an audit tool was designed to enquire in relation to the layout and design of reporting environments, monitor angle and distances used by radiologists when reporting, as well as the ambient factors such as noise, light and temperature. The review of conditions were carried out by the same independent auditor for consistency. The results obtained were compared against international standards and current research. Each radiology environment was given an overall compliance score to establish whether or not their environments were in line with recommended guidelines. Poor compliance to international recommendations and standards among radiology reporting environments was identified. Teleradiology reporting environments demonstrated greater compliance than hospital environments. The findings of this study identified a need for greater awareness of environmental and perceptual issues in the clinical setting. Further work involving a larger number of clinical centres is recommended.

  14. Mobile farm clinic outreach to address health conditions among Latino migrant farmworkers in Georgia.

    PubMed

    Luque, John S; Reyes-Ortiz, Carlos; Marella, Prasen; Bowers, Angelica; Panchal, Viral; Anderson, Lisa; Charles, Simone

    2012-01-01

    Agricultural labor involves exposure to many occupational hazards, some of which can lead to chronic health conditions. The purpose of this study was to conduct an occupational health needs assessment of illnesses and work-related injuries among a Latino migrant farmworker population (recruited to harvest Vidalia onions) in South Georgia. Study data included survey responses from 100 farmworkers attending mobile farm clinics in 2010 at their worker housing residences, supplemented by medical diagnoses data from the same clinics collected over 3 years (2009-2011) for 1161 farmworkers at six different farms. From the survey, the main health problems reported were hypertension (25%), eye problems (12%), musculoskeletal problems (11%), diabetes (10%), and depression (7%). In multivariate analyses, depression scores were associated with having a history of musculoskeletal problems (p = .002). According to the mobile farm clinic data, the most common medical diagnoses included back pain (11.8%), hypertension (11.4%), musculoskeletal problems (11.3%), gastrointestinal disorders (8.6%), eye problems (7.2%), dermatitis or rash (7.0%), and tinea or fungal skin infections (5.6%). The study identified eye and musculoskeletal problems as the major occupational health conditions for this population of farmworkers.

  15. Developing clinical competency in crisis event management: an integrated simulation problem-based learning activity.

    PubMed

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

    2010-08-01

    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 would be superior to those who completed the conventional problem-based session. The students were allocated into either simulation with problem-based discussion (SPBD) or problem-based discussion (PBD) for scenarios on respiratory and cardiac distress. Following completion of each scenario, students from both groups were invited to sit an optional individual test involving a systematic assessment and immediate management of a simulated patient facing a crisis event. A total of thirty students participated in the first post test related to a respiratory scenario and thirty-three participated in the second post test related to a cardiac scenario. Their clinical performances were scored using a checklist. Mean test scores for students completing the SPBD were significantly higher than those who completing the PBD for both the first post test (SPBD 20.08, PBD 18.19) and second post test (SPBD 27.56, PBD 23.07). Incorporation of simulation learning activities into problem-based discussion appeared to be an effective educational strategy for teaching nursing students to assess and manage crisis events.

  16. Sequencing of Simulation and Clinic Experiences in an Introductory Pharmacy Practice Experience

    PubMed Central

    Hajjar, Emily; DeSevo Bellottie, Gina

    2015-01-01

    Objective. To examine how the intrasemester sequencing of a simulation component, delivered during an ambulatory care introductory pharmacy practice experience (IPPE), affects student performance on a series of 3 assessments delivered during the second professional (P2) year. Design. At the Jefferson College of Pharmacy (JCP), P2 student pharmacists were randomly assigned to 6 weeks of simulation activities, followed by 6 weeks on site at an ambulatory care clinic or vice versa during either the fall or spring semesters. At the end of each semester, these students completed 3 skills-based assessments: answering a series of drug information (DI) questions; conducting medication adherence counseling; and conducting a medication history. The 2 groups’ raw scores on assessment rubrics were compared. Assessment. During academic years 2011-2012 and 2012-2013, 180 P2 student pharmacists participated in the required ambulatory care IPPE. Ninety experienced simulation first, while the other 90 experienced the clinic first. Students assessed over a 2-year time span performed similarly on each of 3 skills-based assessments, regardless of how simulation experiences were sequenced within the IPPE. Conclusion. The lack of significant difference in student performance suggests that schools of pharmacy may have flexibility with regard to how they choose to incorporate simulation into clinical ambulatory care IPPEs. PMID:26688585

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

    SciTech Connect

    Turner, J.P.; Hasfurther, V.

    1992-05-04

    The scope of the research program and the continuation is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 [times] 3.0 [times] 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by Rio Blanco Oil Shale Co., Inc. (RBOSC) through a separate cooperative agreement with the University of Wyoming (UW) to carry out this study. Three of the lysimeters were established at the RBOSC Tract C-a in the Piceance Basin of Colorado. Two lysimeters were established in the Environmental Simulation Laboratory (ESL) at UW. The ESL was specifically designed and constructed so that a large range of climatic conditions could be physically applied to the processed oil shale which was filled in the lysimeter cells.

  18. Enhanced desorption of persistent organic pollutants from microplastics under simulated physiological conditions.

    PubMed

    Bakir, Adil; Rowland, Steven J; Thompson, Richard C

    2014-02-01

    Microplastics have the potential to uptake and release persistent organic pollutants (POPs); however, subsequent transfer to marine organisms is poorly understood. Some models estimating transfer of sorbed contaminants to organisms neglect the role of gut surfactants under differing physiological conditions in the gut (varying pH and temperature), examined here. We investigated the potential for polyvinylchloride (PVC) and polyethylene (PE) to sorb and desorb (14)C-DDT, (14)C-phenanthrene (Phe), (14)C-perfluorooctanoic acid (PFOA) and (14)C-di-2-ethylhexyl phthalate (DEHP). Desorption rates of POPs were quantified in seawater and under simulated gut conditions. Influence of pH and temperature was examined in order to represent cold and warm blooded organisms. Desorption rates were faster with gut surfactant, with a further substantial increase under conditions simulating warm blooded organisms. Desorption under gut conditions could be up to 30 times greater than in seawater alone. Of the POP/plastic combinations examined Phe with PE gave the highest potential for transport to organisms.

  19. 3-D simulations to investigate initial condition effects on the growth of Rayleigh-Taylor mixing

    SciTech Connect

    Andrews, Malcolm J

    2008-01-01

    The effect of initial conditions on the growth rate of turbulent Rayleigh-Taylor (RT) mixing has been studied using carefully formulated numerical simulations. An integrated large-eddy simulation (ILES) that uses a finite-volume technique was employed to solve the three-dimensional incompressible Euler equations with numerical dissipation. The initial conditions were chosen to test the dependence of the RT growth parameters ({alpha}{sub b}, {alpha}{sub s}) on variations in (a) the spectral bandwidth, (b) the spectral shape, and (c) discrete banded spectra. Our findings support the notion that the overall growth of the RT mixing is strongly dependent on initial conditions. Variation in spectral shapes and bandwidths are found to have a complex effect of the late time development of the RT mixing layer, and raise the question of whether we can design RT transition and turbulence based on our choice of initial conditions. In addition, our results provide a useful database for the initialization and development of closures describing RT transition and turbulence.

  20. Gaseous exhaust emissions from a JT8D-109 turbofan engine at simulated cruise flight conditions

    NASA Technical Reports Server (NTRS)

    Diehl, L. A.; Holdeman, J. D.

    1975-01-01

    Gaseous emissions from a JT8D-109 turbofan engine were measured in an altitude facility at four simulated cruise flight conditions: Mach 0.8 at altitudes of 9.1, 10, 7, and 12.2 km and Mach 0.9 at 10.7 km. Engine inlet air temperature was held constant at 283 K for all tests. Emissions measurements were made at nominally 6 cm intervals across the horizontal diameter of the engine exhaust nozzle with a single-point traversing gas sample probe. Measured emissions of decreased with increasing altitude from an emission index of 10.4 to one of 8.3, while carbon monoxide increased with increasing altitude from an emission index of 1.6 to one of 4.4. Unburned hydrocarbon emissions were essentially negligible for all flight conditions. Since the engine inlet air temperatures were not correctly simulated, the NOx emission indices were corrected to true altitude conditions by using correlating parameters for changes in combustor inlet temperature, pressure, and temperature rise. The correction was small at the lowest altitude. At the 10.7 and 12.2 km, Mach 0.8 test conditions the correction decreased the measured values by 1 emission index.

  1. Enhanced desorption of persistent organic pollutants from microplastics under simulated physiological conditions.

    PubMed

    Bakir, Adil; Rowland, Steven J; Thompson, Richard C

    2014-02-01

    Microplastics have the potential to uptake and release persistent organic pollutants (POPs); however, subsequent transfer to marine organisms is poorly understood. Some models estimating transfer of sorbed contaminants to organisms neglect the role of gut surfactants under differing physiological conditions in the gut (varying pH and temperature), examined here. We investigated the potential for polyvinylchloride (PVC) and polyethylene (PE) to sorb and desorb (14)C-DDT, (14)C-phenanthrene (Phe), (14)C-perfluorooctanoic acid (PFOA) and (14)C-di-2-ethylhexyl phthalate (DEHP). Desorption rates of POPs were quantified in seawater and under simulated gut conditions. Influence of pH and temperature was examined in order to represent cold and warm blooded organisms. Desorption rates were faster with gut surfactant, with a further substantial increase under conditions simulating warm blooded organisms. Desorption under gut conditions could be up to 30 times greater than in seawater alone. Of the POP/plastic combinations examined Phe with PE gave the highest potential for transport to organisms. PMID:24212067

  2. Clinical study and numerical simulation of brain cancer dynamics under radiotherapy

    NASA Astrophysics Data System (ADS)

    Nawrocki, S.; Zubik-Kowal, B.

    2015-05-01

    We perform a clinical and numerical study of the progression of brain cancer tumor growth dynamics coupled with the effects of radiotherapy. We obtained clinical data from a sample of brain cancer patients undergoing radiotherapy and compare it to our numerical simulations to a mathematical model of brain tumor cell population growth influenced by radiation treatment. We model how the body biologically receives a physically delivered dose of radiation to the affected tumorous area in the form of a generalized LQ model, modified to account for the conversion process of sublethal lesions into lethal lesions at high radiation doses. We obtain good agreement between our clinical data and our numerical simulations of brain cancer progression given by the mathematical model, which couples tumor growth dynamics and the effect of irradiation. The correlation, spanning a wide dataset, demonstrates the potential of the mathematical model to describe the dynamics of brain tumor growth influenced by radiotherapy.

  3. Clinical and ultrasonographic findings of some ocular conditions in sheep and goats

    PubMed Central

    El-Tookhy, O.; Tharwat, M.

    2013-01-01

    This study was carried out to describe the ultrasonographic findings in relation to the clinical symptoms of some common ocular conditions in sheep and goats. Fifty animals (32 goats and 18 sheep) with different ocular problems were examined. Ultrasonographic examination was performed using a B-mode ocular ultrasound unit, and the structure of the globe was evaluated at a depth of 4-6 cm. Early cases (n=35, 70%) showed varying ocular conditions; hypopyon, (n=8, 16%), stromal abscesses, (n=4, 8%), and anterior uveitis (n=23, 46%). Hypopyon appeared clinically as a white or yellowish material in the anterior chamber, and ultrasonographically as a hyperechoic mass in the anterior chamber. Severe iridocyclitis was noticed in acute cases of infectious keratoconjunctivitis (IKC) accompanied by blepharospasm, photophobia, excessive tearing and eyelid margin crust formation. Ultrasonographically, the pupil appeared constricted with increased hyperechoic thickening of the ciliary body. In chronic cases of IKC, corneal pigmentation (n=5, 10%) and cataract (n=10, 20%) were seen. Ultrasonographically the type and degree of cataract were diagnosed. The present study provides an inside view of the inner ocular structures during the course of certain eye diseases where ophthalmoscopic examination is not possible. Our findings, although preliminary, are relevant for the more complete diagnosis of certain external ocular conditions in sheep and goat herds. PMID:26623306

  4. Feather conditions and clinical scores as indicators of broilers welfare at the slaughterhouse.

    PubMed

    Saraiva, S; Saraiva, C; Stilwell, G

    2016-08-01

    The objective of this study was to evaluate the welfare of 64 different broiler farms on the basis of feather conditions and clinical scores measures collected at the slaughterhouse. A 3-point scale (0, 1 or 2) was used to classify dirty feathers, footpad dermatitis and hock burns measures, and a 2-point scale (present or absent) was used to classify breast burns, breast blisters and breast ulcer measures. Flocks were allocated into three body weight (BW) classes (A, B, C): class A (light) ≥1.43 and ≤1.68kg, class B (medium) ≥1.69 and ≤1.93kg; class C (heavy) ≥1.94 and ≤2.41kg. The absence of hock burns was more common in class A, while mild hock burns was more common in class B flocks. Breast ulcer was observed in class C flocks. The association observed for mild hock burns, breast burns and severe footpad dermatitis can indicate a simultaneous occurrence of these painful lesions. Very dirty feathers and severe footpad dermatitis relationship suggest litter humidity to be the common underlying cause. In conclusion, it was shown that clinical indicators can be used at the slaughterhouse to identify welfare problems. In the studied flocks, footpad dermatitis, feather conditions and hock burns were the main restrictions for good welfare and should be considered significant welfare indicators of the on-farm rearing conditions. PMID:27473978

  5. Use of a driving simulator to assess performance under adverse weather conditions in adults with albinism.

    PubMed

    Hofman, Gwen M; Summers, C Gail; Ward, Nicholas; Bhargava, Esha; Rakauskas, Michael E; Holleschau, Ann M

    2012-04-01

    Participants with albinism have reduced vision and nystagmus with reduced foveation times. This prospective study evaluated driving in 12 participants with albinism and 12 matched controls. Participants drove a vehicle simulator through a virtual rural course in sunny and foggy conditions. Under sunny conditions, participants with albinism showed a narrower preferred minimum safety boundary during car-following tasks than did controls, but there was no difference under foggy conditions. Their driving did not differ significantly from that of controls when approaching a stop sign or when choosing gap size between oncoming vehicles when crossing an intersection. However, when compared to control drivers, participants with albinism had a decreased minimum safety boundary for car-following that should be included in counseling regarding driving safety.

  6. Measurement of exhaust emissions from two J-58 engines at simulated supersonic cruise flight conditions

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1976-01-01

    Emissions of total oxides of nitrogen, unburned hydrocarbons, carbon monoxide, and carbon dioxide from two J-58 afterburning turbojet engines at simulated high-altitude flight conditions are reported. Test conditions included flight speeds from Mach 2 to 3 at altitudes from 16 to 23 km. For each flight condition, exhaust measurements were made for four or five power levels from maximum power without afterburning through maximum afterburning. The data show that exhaust emissions vary with flight speed, altitude, power level, and radial position across the exhaust. Oxides of nitrogen (NOX) emissions decreased with increasing altitude, and increased with increasing flight speed. NOX emission indices with afterburning were less than half the value without afterburning. Carbon monoxide and hydrocarbon emissions increased with increasing altitude, and decreased with increasing flight speed. Emissions of these species were substantially higher with afterburning than without.

  7. Measurement of exhaust emissions from two J-58 engines at simulated supersonic cruise flight conditions

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1976-01-01

    Emissions of total oxides of nitrogen, unburned hydrocarbons, carbon monoxide, and carbon dioxide from two J-58 afterburning turbojet engines at simulated high-altitude flight conditions are reported. Test conditions included flight speeds from Mach 2 to 3 at altitudes from 16 to 23 km. For each flight condition, exhaust measurements were made for four or five power levels from maximum power without afterburning through maximum afterburning. The data show that exhaust emissions vary with flight speed, altitude, power level, and radial position across the exhaust. Oxides of nitrogen emissions decreased with increasing altitude and increased with increasing flight speed. NO(x) emission indices with afterburning were less than half the value without afterburning. Carbon monoxide and hydrocarbon emissions increased with increasing altitude and decreased with increasing flight speed. Emissions of these species were substantially higher with afterburning than without.

  8. Accuracy of the Frensley inflow boundary condition for Wigner equations in simulating resonant tunneling diodes

    SciTech Connect

    Jiang Haiyan; Cai Wei; Tsu, Raphael

    2011-03-01

    In this paper, the accuracy of the Frensley inflow boundary condition of the Wigner equation is analyzed in computing the I-V characteristics of a resonant tunneling diode (RTD). It is found that the Frensley inflow boundary condition for incoming electrons holds only exactly infinite away from the active device region and its accuracy depends on the length of contacts included in the simulation. For this study, the non-equilibrium Green's function (NEGF) with a Dirichlet to Neumann mapping boundary condition is used for comparison. The I-V characteristics of the RTD are found to agree between self-consistent NEGF and Wigner methods at low bias potentials with sufficiently large GaAs contact lengths. Finally, the relation between the negative differential conductance (NDC) of the RTD and the sizes of contact and buffer in the RTD is investigated using both methods.

  9. Basic concepts and clinical findings in the treatment of seizure disorders with EEG operant conditioning.

    PubMed

    Sterman, M B

    2000-01-01

    Two issues concerning sensorimotor EEG operant conditioning, or biofeedback, as a therapeutic modality for the treatment of seizure disorders are the focus of this review. The first relates to the question of whether relevant physiological changes are associated with this procedure. This question is addressed through review of an extensive neurophysiological literature that is likely unfamiliar to many clinicians but that documents both immediate and sustained functional changes that are consistent with elevation of seizure thresholds. The second focuses on the clinical efficacy of this method and whether it should carry the designation of "experimental". This designation is challenged through an assessment of over 25 years of peer-reviewed research demonstrating impressive EEG and clinical results achieved with the most difficult subset of seizure patients.

  10. To pre-challenge lactic acid bacteria with simulated gastrointestinal conditions is a suitable approach to studying potential probiotic properties.

    PubMed

    Huang, Hui-Ying; Hsieh, Hsin-Yi; King, V An-Erl; Chi, Li-Ling; Tsen, Jen-Horng

    2014-12-01

    The potential probiotic properties of lactic acid bacteria (LAB) after treatment with gastrointestinal (GI) conditions were investigated. Some LAB strains that survived simulated GI treatment retained their adhesiveness and antagonism against the pathogen. Therefore pre-challenging LAB with simulated GI conditions is a suitable way for potential probiotic studies. PMID:25281473

  11. Numerical simulation of diurnally varying thermal environment in a street canyon under haze-fog conditions

    NASA Astrophysics Data System (ADS)

    Tan, Zijing; Dong, Jingliang; Xiao, Yimin; Tu, Jiyuan

    2015-10-01

    The impact of haze-fog on surface temperature, flow pattern, pollutant dispersion and pedestrian thermal comfort are investigated using computational fluid dynamics (CFD) approach based on a three-dimensional street canyon model under different haze-fog conditions. In this study, light extinction coefficient (Kex) is adopted to represent haze-fog pollution level. Numerical simulations are performed for different Kex values at four representative time events (1000 LST, 1300 LST, 1600 LST and 2000 LST). The numerical results suggest that the surface temperature is strongly affected by the haze-fog condition. Surface heating induced by the solar radiation is enhanced by haze-fog, as higher surface temperature is observed under thicker haze-fog condition. Moreover, the temperature difference between sunlit and shadow surfaces is reduced, while that for the two shadow surfaces is slightly increased. Therefore, the surface temperature among street canyon facets becomes more evenly distributed under heavy haze-fog conditions. In addition, flow patterns are considerably altered by different haze-fog conditions, especially for the afternoon (1600 LST) case, in which thermal-driven flow has opposite direction as that of the wind-driven flow direction. Consequently, pollutants such as vehicular emissions will accumulate at pedestrian level, and pedestrian thermal comfort may lower under thicker haze-fog condition.

  12. The salt marsh vegetation spread dynamics simulation and prediction based on conditions optimized CA

    NASA Astrophysics Data System (ADS)

    Guan, Yujuan; Zhang, Liquan

    2006-10-01

    The biodiversity conservation and management of the salt marsh vegetation relies on processing their spatial information. Nowadays, more attentions are focused on their classification surveying and describing qualitatively dynamics based on RS images interpreted, rather than on simulating and predicting their dynamics quantitatively, which is of greater importance for managing and planning the salt marsh vegetation. In this paper, our notion is to make a dynamic model on large-scale and to provide a virtual laboratory in which researchers can run it according requirements. Firstly, the characteristic of the cellular automata was analyzed and a conclusion indicated that it was necessary for a CA model to be extended geographically under varying conditions of space-time circumstance in order to make results matched the facts accurately. Based on the conventional cellular automata model, the author introduced several new conditions to optimize it for simulating the vegetation objectively, such as elevation, growth speed, invading ability, variation and inheriting and so on. Hence the CA cells and remote sensing image pixels, cell neighbors and pixel neighbors, cell rules and nature of the plants were unified respectively. Taking JiuDuanSha as the test site, where holds mainly Phragmites australis (P.australis) community, Scirpus mariqueter (S.mariqueter) community and Spartina alterniflora (S.alterniflora) community. The paper explored the process of making simulation and predictions about these salt marsh vegetable changing with the conditions optimized CA (COCA) model, and examined the links among data, statistical models, and ecological predictions. This study exploited the potential of applying Conditioned Optimized CA model technique to solve this problem.

  13. Optimization of Pilot Point Locations for Conditional Simulation of Heterogeneous Aquifers

    NASA Astrophysics Data System (ADS)

    Mehne, J.; Nowak, W.

    2011-12-01

    Spatial variability of geological media in conjunction with scarce data introduces parameter and prediction uncertainties in simulations of flow and transport. Conditional simulation methods use the Monte Carlo framework combined with inverse modeling techniques to incorporate available field data and, thus, to reduce these uncertainties. The pilot point method is a wide-spread method that can be used for conditional simulation in order to condition multiple realizations of heterogeneous conductivity fields on available field data. Virtual direct measurements of conductivity, placed at so called pilot points, are introduced and their values are optimized until all available field data is honored. Adequate placement and numbers of pilot points are crucial both for accurate representation of heterogeneity and to control computational costs. Current placement methods for pilot points depend solely on the expertise and experience of the modeler or involve computationally costly sensitivity analyses. This study presents a new method for optimal pilot point placement. Ideas from geostatistical optimal design and ensemble Kalman filters are combined. The proposed method emulates the pilot point method at drastically reduced computational costs by avoiding the evaluation of sensitivity coefficients. A task-driven measure for optimal design of pilot point placement patterns is evaluated without carrying out the actual conditioning process. This makes it possible to efficiently compare a high number of possible patterns for pilot point placement. By formal optimization of this measure, pilot point placement schemes are found that are optimal in representing the data with minimal numbers of pilot points. Small synthetic test applications of the proposed method showed a promising computational performance and a geostatistically logical choice of pilot point locations. In comparison with a regularly spaced pilot point grid, equally good calibration results were achieved by a

  14. Simulation of clinical fractures for three different all-ceramic crowns.

    PubMed

    Oilo, Marit; Kvam, Ketil; Gjerdet, Nils R

    2014-06-01

    Comparison of fracture strength and fracture modes of different all-ceramic crown systems is not straightforward. Established methods for reliable testing of all-ceramic crowns are not currently available. Published in-vitro tests rarely simulate clinical failure modes and are therefore unsuited to distinguish between the materials. The in-vivo trials usually lack assessment of failure modes. Fractographic analyses show that clinical crowns usually fail from cracks initiating in the cervical margins, whereas in-vitro specimens fail from contact damage at the occlusal loading point. The aim of this study was to compare three all-ceramic systems using a clinically relevant test method that is able to simulate clinical failure modes. Ten incisor crowns of three types of all-ceramic systems were exposed to soft loading until fracture. The initiation and propagation of cracks in these crowns were compared with those of a reference group of crowns that failed during clinical use. All crowns fractured in a manner similar to fracture of the clinical reference crowns. The zirconia crowns fractured at statistically significantly higher loads than alumina and glass-ceramic crowns. Fracture initiation was in the core material, cervically in the approximal areas. PMID:24698209

  15. Simulation of clinical fractures for three different all-ceramic crowns

    PubMed Central

    Øilo, Marit; Kvam, Ketil; Gjerdet, Nils R

    2014-01-01

    Comparison of fracture strength and fracture modes of different all-ceramic crown systems is not straightforward. Established methods for reliable testing of all-ceramic crowns are not currently available. Published in-vitro tests rarely simulate clinical failure modes and are therefore unsuited to distinguish between the materials. The in-vivo trials usually lack assessment of failure modes. Fractographic analyses show that clinical crowns usually fail from cracks initiating in the cervical margins, whereas in-vitro specimens fail from contact damage at the occlusal loading point. The aim of this study was to compare three all-ceramic systems using a clinically relevant test method that is able to simulate clinical failure modes. Ten incisor crowns of three types of all-ceramic systems were exposed to soft loading until fracture. The initiation and propagation of cracks in these crowns were compared with those of a reference group of crowns that failed during clinical use. All crowns fractured in a manner similar to fracture of the clinical reference crowns. The zirconia crowns fractured at statistically significantly higher loads than alumina and glass-ceramic crowns. Fracture initiation was in the core material, cervically in the approximal areas. PMID:24698209

  16. Physiological Responses and Performance Analysis Difference between Official and Simulated Karate Combat Conditions

    PubMed Central

    Chaabène, Helmi; Mkaouer, Bessem; Franchini, Emerson; Souissi, Nafaa; Selmi, Mohamed Amine; Nagra, Yassine; Chamari, Karim

    2013-01-01

    Purpose This study aimed to compare physiological responses and time-motion analysis between official and simulated karate combat. Methods Ten high-level karatekas participated in this study, which included official and simulated karate combat. Results Karatekas used more upper-limb attack techniques during official combat compared to simulated ones (6±3 vs 3±1; P=0.05, respectively). For official and simulated karate matches, the numbers of high-intensity actions (i.e. offensive and defensive fighting activity) were 14±6 and 18±5, respectively (P>0.05), lasting from <1s to 5s each. Total fighting activity phase was lower during official compared to simulated matches (21.0±8.2s vs 30.4±9.9s, P<0.01, respectively). Effort (10.0±2.8s) to rest (11.9±2.7s) ratio (E:R) was 1:1 and high-intensity actions (1.6±0.3s) to rest (11.9±2.7s) ratio was higher than 1:7 during simulated combat. During official karate match, the activity and rest duration were 10.0±3.4s and 16.2±4.1s, respectively (E:R ratio 1:1.5), while high-intensity actions were 1.5±0.3s, resulting in an E:R ratio of 1:11. Blood lactate concentration was higher during official (11.14±1.82 mmol.l-1) compared to simulated karate combat (7.80±2.66 mmol.l-1) (P<0.05). Subjective perceived exertion differed significantly between official and simulated combat (14±2 vs. 12±2; P<0.05, respectively). The majority of karatekas’ perceived exertion was higher in the lower limb muscle groups irrespective of the karate combat condition. Conclusion Official and simulated matches differ considerably, therefore coaches should create new strategies during training sessions to achieve the same effort and pause profile of competitive matches and/or that athletes should be submitted to frequent competitions to adapt themselves to the profile of this event. PMID:24868428

  17. Understanding the Source Conditions of Enceladus' Plume via Direct Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Yeoh, S.; Goldstein, D. B.; Varghese, P.; Trafton, L.

    2013-12-01

    The two-phase (gas/grain) plume, composed primarily of H2O, arising from Enceladus' south polar region provides a valuable window into the subsurface conditions on Enceladus. To understand the source conditions and plume generation mechanisms, we developed a hybrid model of the plume that divides it into two regimes: an inner collisional regime simulated using the direct simulation Monte Carlo (DSMC) method and an outer collisionless regime simulated using a free-molecular model. The plume was constructed by simulating two-phase flows from multiple sources on Enceladus' surface out to several Enceladus radii where Cassini in-situ data are available. This model accounts for non-equilibrium effects (e.g. the freezing of molecular internal modes), a two-way coupling between gas and grains, Enceladus' rotation and orbital motion around Saturn, and the gravitational fields of Enceladus and Saturn. Our results were compared with in-situ data from the Ion and Neutral Mass Spectrometer (INMS) and the Cosmic Dust Analyzer (CDA) from the E2, E3, E5 and E7 flybys. To obtain vent conditions for simulations, we adopted a simple subsurface model by assuming an isentropic flow through a converging-diverging channel. By selecting a reasonable channel geometry based on observational constraints, a Mach-5 flow was obtained at the vent. The Mach-5 vent conditions are consistent with the observed grain size distributions. Our simulations indicated that grains can form via condensation directly above the vents because the gas is highly supersaturated just as it expands out of the vents. However, this calculation is based on the assumption that no condensation occurs within the subsurface channel, which may heat the gas up through the release of latent heat and therefore reduce the supersaturation level of the gas. The grains have a negligible effect on the gas flow when the mass loading is ≤ 10%. Nanometer-sized grains track the gas flow and spread out while micron-sized grains

  18. Simulation of Deep Water Renewal in Crater Lake, Oregon, USA under Current and Future Climate Conditions

    NASA Astrophysics Data System (ADS)

    Piccolroaz, S.; Wood, T. M.; Wherry, S.; Girdner, S.

    2015-12-01

    We applied a 1-dimensional lake model developed to simulate deep mixing related to thermobaric instabilities in temperate lakes to Crater Lake, a 590-m deep caldera lake in Oregon's Cascade Range known for its stunning deep blue color and extremely clear water, in order to determine the frequency of deep water renewal in future climate conditions. The lake model was calibrated with 6 years of water temperature profiles, and then simulated 10 years of validation data with an RMSE ranging from 0.81°C at 50 m depth to 0.04°C at 350-460 m depth. The simulated time series of heat content in the deep lake accurately captured extreme years characterized by weak and strong deep water renewal. The lake model uses wind speed and lake surface temperature (LST) as boundary conditions. LST projections under six climate scenarios from the CMIP5 intermodel comparison project (2 representative concentration pathways X 3 general circulation models) were evaluated with air2water, a simple lumped model that only requires daily values of downscaled air temperature. air2water was calibrated with data from 1993-2011, resulting in a RMSE between simulated and observed daily LST values of 0.68°C. All future climate scenarios project increased water temperature throughout the water column and a substantive reduction in the frequency of deepwater renewal events. The least extreme scenario (CNRM-CM5, RCP4.5) projects the frequency of deepwater renewal events to decrease from about 1 in 2 years in the present to about 1 in 3 years by 2100. The most extreme scenario (HadGEM2-ES, RCP8.5) projects the frequency of deepwater renewal events to be less than 1 in 7 years by 2100 and lake surface temperatures never cooling to less than 4°C after 2050. In all RCP4.5 simulations the temperature of the entire water column is greater than 4°C for increasing periods of time. In the RCP8.5 simulations, the temperature of the entire water column is greater than 4°C year round by the year 2060 (HadGEM2

  19. Site characterization, visualization, and uncertainty assessment using zonal kriging and conditional simulation

    SciTech Connect

    Wingle, W.L.

    1996-12-31

    When evaluating a site, whether for oil, minerals, or contaminants in ground water, a principle concern is the distribution of material properties. A traditional approach has been to apply geostatistical methods such as kriging or conditional simulation. These approaches are based on the assumption of stationarity (i.e. that the spatial variation of properties is consistent across the site). At many sites, the stationarity assumption is not valid and can lead to inaccurate results. One approach to circumvent this limitation is to divide the area into zones where the stationarity assumptions are reasonable, krige each zone, and manually merge the results together. This approach has three major draw backs, (1) boundaries between zones are abrupt, (2) the merging process is tedious, and (3) there is no way to manage{open_quote}gradational{close_quote} boundaries. An integrated system which allows a modeler to: (1) define multiple, distinct zones within a model; (2) define zonal inter-relationships (e.g. Zone A grades into zone B. Zone C and Zone D have a sharp contact), and model the results using simple or ordinary kriging, or conditional simulation is presented. This technique is integrated into a modeling package which allows users to examine basic site statistics, develop and model semivariograms, krige and simulate material properties, model ground water flow and contaminant transport, assess risk or uncertainty, and visualize results with 2D, 2-1/2D, and 3D tools.

  20. Site characterization, visualization, and uncertainty assessment using zonal kriging and conditional simulation

    SciTech Connect

    Wingle, W.L. )

    1996-01-01

    When evaluating a site, whether for oil, minerals, or contaminants in ground water, a principle concern is the distribution of material properties. A traditional approach has been to apply geostatistical methods such as kriging or conditional simulation. These approaches are based on the assumption of stationarity (i.e. that the spatial variation of properties is consistent across the site). At many sites, the stationarity assumption is not valid and can lead to inaccurate results. One approach to circumvent this limitation is to divide the area into zones where the stationarity assumptions are reasonable, krige each zone, and manually merge the results together. This approach has three major draw backs, (1) boundaries between zones are abrupt, (2) the merging process is tedious, and (3) there is no way to manage[open quote]gradational[close quote] boundaries. An integrated system which allows a modeler to: (1) define multiple, distinct zones within a model; (2) define zonal inter-relationships (e.g. Zone A grades into zone B. Zone C and Zone D have a sharp contact), and model the results using simple or ordinary kriging, or conditional simulation is presented. This technique is integrated into a modeling package which allows users to examine basic site statistics, develop and model semivariograms, krige and simulate material properties, model ground water flow and contaminant transport, assess risk or uncertainty, and visualize results with 2D, 2-1/2D, and 3D tools.

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

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1991-01-01

    Laboratory measurements of microwave and millimeter wave properties of the simulated atmosphere of the outer planets and their satellites has continued. One of the focuses is on the development of a radiative transfer model of the Jovian atmosphere at wavelengths from 1 mm to 10 cm. This modeling effort led to laboratory measurements of the millimeter wave opacity of hydrogen sulfide (H2S) under simulated Jovian conditions. Descriptions of the modeling effort, the Laboratory experiment, and the observations are presented. Correlative studies of measurements with Pioneer-Venus radio occultation measurements with longer wavelength emission measurements have provided new ways for characterizing temporal and spatial variations in the abundance of both gases H2SO4 and SO2, and for modeling their roles in the subcloud atmosphere. Laboratory measurements were conducted on 1.35 cm (and 13 cm) opacity of gaseous SO2 and absorptivity of gaseous SO2 at the 3.2 mm wavelength under simulated Venus conditions. Laboratory measurements were completed on millimeter wave dielectric properties of liquid H2SO4, in order to model the effects of the opacity of the clouds of Venus onto millimeter wave emission spectrum.

  2. Inactivation of enteropathogenic E. coli by solar disinfection (SODIS) under simulated sunlight conditions

    NASA Astrophysics Data System (ADS)

    Ubomba-Jaswa, E.; Boyle, M. A. R.; McGuigan, K. G.

    2008-02-01

    Solar Disinfection (SODIS) is a low cost water treatment method currently used in communities that do not have year round access to safe water. However, there is still reluctance in widespread adoption of this treatment method due to a number of limitations. An important limitation is the lack of SODIS inactivation studies on some waterborne pathogens in the developing world. SODIS inactivation of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhoea is reported for the first time under simulated sunlight conditions and following a natural temperature profile. EPEC was exposed to simulated sunlight (885Wm-2) for periods up to a cumulative time of 4 hours. Inactivation was determined by a log reduction in growth of the organisms. The temperature (°C) of the water was taken at every time point. After 4 hours exposure EPEC was completely inactivated (7 log reduction) by SODIS. Imposing a realistic water temperature profile (min-max) concomitant with irradiation produces a greater kill of EPEC. Maintaining simulated sunlight experiments at a high fixed temperature may result in over --estimation of inactivation. Following a natural water temperature profile will result in more reliable inactivation comparable with those that might be obtained under natural sunlight conditions.

  3. Aging and the detection of imminent collisions under simulated fog conditions.

    PubMed

    Ni, Rui; Bian, Zheng; Guindon, Amy; Andersen, George J

    2012-11-01

    The present study examined age-related differences in collision detection performance when contrast of the driving scene was reduced by simulated fog. Older and younger drivers were presented with a collision detection scenario in a simulator in which an object moved at a constant speed on a linear trajectory towards the driver. Drivers were shown part of the motion path of an approaching object that would eventually either collide with or pass by the driver and were required to determine whether or not the object would collide with the driver. Driver motion was either stationary or moving along a linear path down the roadway. A no fog condition and three different levels of fog were examined. Detection performance decreased when dense fog was simulated for older but not for younger observers. An age-related decrement was also found with shorter display durations (longer time to contact). When the vehicle was moving decrements in performance were observed for both younger and older drivers. These results suggest that under inclement weather conditions with reduced visibility, such as fog, older drivers may have an increased crash risk due to a decreased ability to detect impending collision events.

  4. [Clinical course of asbestosis under the existing conditions in extraction and processing of serpentine asbestos].

    PubMed

    Likhacheva, E I; Semennikova, T K; Vagina, E R; Iarina, A L; Klimina, M S

    1999-01-01

    The authors followed changes in clinical course of asbestosis, comparing groups of individuals working in exposure to chrysotile-asbestos dust, patients having so-called late asbestosis and reference group (individuals with absent or minimal roentgenologic changes in lungs). Analysis of 530 case histories proved increase of average length of service in dusty conditions before asbestosis development, longer progression of pulmonary fibrosis. Asbestosis progression does not depend on medical resolutions. "Late" asbestosis occurs in retired workers who were engaged into auxiliary occupations. Low baseline values of respiratory function and associated respiratory infection worsen the overall prognosis.

  5. Revisiting geriatric failure to thrive: a complex and compelling clinical condition.

    PubMed

    Rocchiccioli, Judith Townsend; Sanford, Julie Tanner

    2009-01-01

    Geriatric failure to thrive (GFTT) poses a complex clinical issue in gerontological nursing practice. GFTT is not a normal part of aging, nor is it an outcome of chronic illness. Rather, GFTT describes a lack of vitality and diminished capacity for life and outlines a process of functional decline that is often difficult to explain. The purpose of this article is to review GFTT, examine the literature on GFTT, and suggest strategies for the identification, assessment, and creative management of this complex condition that affects millions of older adults.

  6. Anterior Cruciate Ligament Biomechanics During Robotic and Mechanical Simulations of Physiologic and Clinical Motion Tasks: A Systematic Review and Meta-Analysis

    PubMed Central

    Bates, Nathaniel A.; Myer, Gregory D.; Shearn, Jason T.; Hewett, Timothy E.

    2014-01-01

    Investigators use in vitro joint simulations to invasively study the biomechanical behaviors of the anterior cruciate ligament. The aims of these simulations are to replicate physiologic conditions, but multiple mechanisms can be used to drive in vitro motions, which may influence biomechanical outcomes. The objective of this review was to examine, summarize, and compare biomechanical evidence related to anterior cruciate ligament function from in vitro simulations of knee motion. A systematic review was conducted (2004 to 2013) in Scopus, PubMed/Medline, and SPORTDiscus to identify peer-reviewed studies that reported kinematic and kinetic outcomes from in vitro simulations of physiologic or clinical tasks at the knee. Inclusion criteria for relevant studies were articles published in English that reported on whole-ligament anterior cruciate ligament mechanics during the in vitro simulation of physiologic or clinical motions on cadaveric knees that were unaltered outside of the anterior-cruciate-ligament-intact, -deficient, and -reconstructed conditions. A meta-analysis was performed to synthesize biomechanical differences between the anterior-cruciate-ligament-intact and reconstructed conditions. 77 studies met our inclusion/exclusion criteria and were reviewed. Combined joint rotations have the greatest impact on anterior cruciate ligament loads, but the magnitude by which individual kinematic degrees of freedom contribute to ligament loading during in vitro simulations is technique-dependent. Biomechanical data collected in prospective, longitudinal studies corresponds better with robotic-manipulator simulations than mechanical-impact simulations. Robotic simulation indicated that the ability to restore intact anterior cruciate ligament mechanics with anterior cruciate ligament reconstructions was dependent on loading condition and degree of freedom examined. PMID:25547070

  7. Anterior cruciate ligament biomechanics during robotic and mechanical simulations of physiologic and clinical motion tasks: a systematic review and meta-analysis.

    PubMed

    Bates, Nathaniel A; Myer, Gregory D; Shearn, Jason T; Hewett, Timothy E

    2015-01-01

    Investigators use in vitro joint simulations to invasively study the biomechanical behaviors of the anterior cruciate ligament. The aims of these simulations are to replicate physiologic conditions, but multiple mechanisms can be used to drive in vitro motions, which may influence biomechanical outcomes. The objective of this review was to examine, summarize, and compare biomechanical evidence related to anterior cruciate ligament function from in vitro simulations of knee motion. A systematic review was conducted (2004 to 2013) in Scopus, PubMed/Medline, and SPORTDiscus to identify peer-reviewed studies that reported kinematic and kinetic outcomes from in vitro simulations of physiologic or clinical tasks at the knee. Inclusion criteria for relevant studies were articles published in English that reported on whole-ligament anterior cruciate ligament mechanics during the in vitro simulation of physiologic or clinical motions on cadaveric knees that were unaltered outside of the anterior-cruciate-ligament-intact, -deficient, and -reconstructed conditions. A meta-analysis was performed to synthesize biomechanical differences between the anterior-cruciate-ligament-intact and reconstructed conditions. 77 studies met our inclusion/exclusion criteria and were reviewed. Combined joint rotations have the greatest impact on anterior cruciate ligament loads, but the magnitude by which individual kinematic degrees of freedom contribute to ligament loading during in vitro simulations is technique-dependent. Biomechanical data collected in prospective, longitudinal studies corresponds better with robotic-manipulator simulations than mechanical-impact simulations. Robotic simulation indicated that the ability to restore intact anterior cruciate ligament mechanics with anterior cruciate ligament reconstructions was dependent on loading condition and degree of freedom examined.

  8. Time-Accurate Unsteady Pressure Loads Simulated for the Space Launch System at Wind Tunnel Conditions

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

    A transonic flow field about a Space Launch System (SLS) configuration was simulated with the Fully Unstructured Three-Dimensional (FUN3D) computational fluid dynamics (CFD) code at wind tunnel conditions. Unsteady, time-accurate computations were performed using second-order Delayed Detached Eddy Simulation (DDES) for up to 1.5 physical seconds. The surface pressure time history was collected at 619 locations, 169 of which matched locations on a 2.5 percent wind tunnel model that was tested in the 11 ft. x 11 ft. test section of the NASA Ames Research Center's Unitary Plan Wind Tunnel. Comparisons between computation and experiment showed that the peak surface pressure RMS level occurs behind the forward attach hardware, and good agreement for frequency and power was obtained in this region. Computational domain, grid resolution, and time step sensitivity studies were performed. These included an investigation of pseudo-time sub-iteration convergence. Using these sensitivity studies and experimental data comparisons, a set of best practices to date have been established for FUN3D simulations for SLS launch vehicle analysis. To the author's knowledge, this is the first time DDES has been used in a systematic approach and establish simulation time needed, to analyze unsteady pressure loads on a space launch vehicle such as the NASA SLS.

  9. Effects of temperature and humidity on respirator fit under simulated work conditions

    SciTech Connect

    Skaggs, B.J.; Loibl, J.M.; Carter, K.D.; Hyatt, E.C.

    1988-07-01

    A study conducted at the Los Alamos National Laboratory compared quantitative fit factors and simulated work factors and determined the effects of temperature and humidity on respirator fit. This study used a commercially available fit chamber and an environmental chamber set at six conditions to simulate US work environments. Seven respirators were tested on a limited test panel of 10 subjects. The test results indicate that the performance of one powered air-purifying respirator (PAPR) helmet is significantly degraded during the simulated work exercises, whereas the half-mask PAPR performance was not affected. Tight-fitting facepiece PAPRs provide higher protection than loose-fitting PAPRs. The performance of the negative-pressure half-mask and full-facepiece respirators is degraded during fit tests at high humidity and high temperature. The degradation of the fit factors for the negative-pressure half-mask during high humidity at ambient and high temperatures is probably due to facepiece slippage caused by sweating. More dynamic exercises, including motions in which the individual bends over and stands up repeatedly, are recommended to develop quantitative fit factors that adequately simulate work factors. Tight-fitting facepiece PAPRs should not be classified with loose-fitting PAPRs. 12 refs., 7 figs., 14 tabs.

  10. Investigation into piston-slap-induced vibration for engine condition simulation and monitoring

    NASA Astrophysics Data System (ADS)

    Geng, Z.; Chen, J.

    2005-04-01

    Piston slap is a common impact phenomenon existing in the reciprocating engine. It is also a major cause of the complex transient vibration response related to the impact excitation inside the engine. In order to correlate the piston-slap impact with the slap-induced vibration and consequently find out an effective approach for the engine dynamic behaviour simulation and working condition monitoring, an in-depth investigation from theoretical modelling to experimental verification is made in this paper. Firstly, the piston-slap phenomenon inside the reciprocating engine is briefly discussed from the viewpoint of engine mechanics. Based upon this, a nonlinear model is developed to simulate the slap-induced vibration response. Using numerical integration procedure, the slap-induced vibration response and its correlation with the inner-cylinder piston-slap impact are reasonably evaluated. Guided by the simulating results and, by introducing a fast wavelet-packet decomposition and reconstruction algorithm, a specially designed experiment is made to practically measure and extract the slap-induced impact message inside the 6190Z LC diesel engine. Comparison between the simulation and practically measured and reconstructed engine vibration signals verifies the effectiveness and practicality of this approach for more detailed academic research and engineering application.

  11. Jet transport flight operations using cockpit display of traffic information during instrument meteorological conditions: Simulation evaluation

    NASA Technical Reports Server (NTRS)

    Williams, David H.; Wells, Douglas C.

    1986-01-01

    A simulation study was undertaken to evaluate flight operations using cockpit display of traffic information (CDTI) in a conventional jet transport aircraft. Eight two-person airline flight crews participated as test subjects flying simulated terminal area approach and departure operations under instrument meteorological conditions (IMC). A fixed-base cockpit simulator configured with a full complement of conventional electromechanical instrumentation to permit full workload operations was utilized. Traffic information was displayed on a color cathode-ray tube (CRT) mounted above the throttle quadrant in the typical weather radar location. A transparent touchpanel overlay was utilized for pilot interface with the display. Air traffic control (ATC) simulation included an experienced controller and full partyline radio environment for evaluation of pilot-controlled self-separation and traffic situation monitoring tasks. Results of the study revealed the CDTI to be well received by the test subjects as a useful system which could be incorporated into an existing jet transport cockpit. Crew coordination and consistent operating procedures were identified as important considerations in operational implementation of traffic displays. Cockpit workload was increased with active CDTI tasks. However, all test subjects rated the increase to be acceptable.

  12. SiC/SiC Leading Edge Turbine Airfoil Tested Under Simulated Gas Turbine Conditions

    NASA Technical Reports Server (NTRS)

    Robinson, R. Craig; Hatton, Kenneth S.

    1999-01-01

    Silicon-based ceramics have been proposed as component materials for use in gas turbine engine hot-sections. A high pressure burner rig was used to expose both a baseline metal airfoil and ceramic matrix composite leading edge airfoil to typical gas turbine conditions to comparatively evaluate the material response at high temperatures. To eliminate many of the concerns related to an entirely ceramic, rotating airfoil, this study has focused on equipping a stationary metal airfoil with a ceramic leading edge insert to demonstrate the feasibility and benefits of such a configuration. Here, the idea was to allow the SiC/SiC composite to be integrated as the airfoil's leading edge, operating in a "free-floating" or unrestrained manner. and provide temperature relief to the metal blade underneath. The test included cycling the airfoils between simulated idle, lift, and cruise flight conditions. In addition, the airfoils were air-cooled, uniquely instrumented, and exposed to the same internal and external conditions, which included gas temperatures in excess of 1370 C (2500 F). Results show the leading edge insert remained structurally intact after 200 simulated flight cycles with only a slightly oxidized surface. The instrumentation clearly suggested a significant reduction (approximately 600 F) in internal metal temperatures as a result of the ceramic leading edge. The object of this testing was to validate the design and analysis done by Materials Research and Design of Rosemont, PA and to determine the feasibility of this design for the intended application.

  13. [The effect of magnitopuncture stimulation on HRV during simulated driving under vibration conditions].

    PubMed

    Li, Zengyong; Jiao, Kun; Chen, Ming; Wang, Chengtao; Qi, Shaohua

    2003-03-01

    The purpose of this study was to assess the effect of magnitopuncture stimuli for reducing driver mental stress and fatigue using power spectral analysis of the heart rate variability (HRV) and subjective evaluation. The experiments were divided into A-group and B-group. In both groups the subjects performed the simulator for 90 minutes under a vibration conditions with an erect sitting posture in a silent environment, and magnitopuncture was put on the acupoints when performing the task for one hour in A-group. In this study HRV exhibited a significant difference between the two groups after the simulating task (P < 0.05). A conclusion that magnitopuncture stimuli can reduce the driver mental stress and fatigue effectively was drawn.

  14. Biological Membranes in Extreme Conditions: Simulations of Anionic Archaeal Tetraether Lipid Membranes

    PubMed Central

    Pineda De Castro, Luis Felipe; Dopson, Mark

    2016-01-01

    In contrast to the majority of organisms that have cells bound by di-ester phospholipids, archaeal membranes consist of di- and tetraether phospholipids. Originating from organisms that withstand harsh conditions (e.g., low pH and a wide range of temperatures) such membranes have physical properties that make them attractive materials for biological research and biotechnological applications. We developed force-field parameters based on the widely used Generalized Amber Force Field (GAFF) to enable the study of anionic tetraether membranes of the model archaean Sulfolobus acidocaldarius by computer simulations. The simulations reveal that the physical properties of these unique membranes depend on the number of cyclopentane rings included in each lipid unit, and on the size of cations that are used to ensure charge neutrality. This suggests that the biophysical properties of Sulfolobus acidocaldarius cells depend not only on the compositions of their membranes but also on the media in which they grow. PMID:27167213

  15. Pose Measurement Performance of the Argon Relative Navigation Sensor Suite in Simulated Flight Conditions

    NASA Technical Reports Server (NTRS)

    Galante, Joseph M.; Eepoel, John Van; Strube, Matt; Gill, Nat; Gonzalez, Marcelo; Hyslop, Andrew; Patrick, Bryan

    2012-01-01

    Argon is a flight-ready sensor suite with two visual cameras, a flash LIDAR, an on- board flight computer, and associated electronics. Argon was designed to provide sensing capabilities for relative navigation during proximity, rendezvous, and docking operations between spacecraft. A rigorous ground test campaign assessed the performance capability of the Argon navigation suite to measure the relative pose of high-fidelity satellite mock-ups during a variety of simulated rendezvous and proximity maneuvers facilitated by robot manipulators in a variety of lighting conditions representative of the orbital environment. A brief description of the Argon suite and test setup are given as well as an analysis of the performance of the system in simulated proximity and rendezvous operations.

  16. Numerical simulation of tonal fan noise of computers and air conditioning systems

    NASA Astrophysics Data System (ADS)

    Aksenov, A. A.; Gavrilyuk, V. N.; Timushev, S. F.

    2016-07-01

    Current approaches to fan noise simulation are mainly based on the Lighthill equation and socalled aeroacoustic analogy, which are also based on the transformed Lighthill equation, such as the wellknown FW-H equation or the Kirchhoff theorem. A disadvantage of such methods leading to significant modeling errors is associated with incorrect solution of the decomposition problem, i.e., separation of acoustic and vortex (pseudosound) modes in the area of the oscillation source. In this paper, we propose a method for tonal noise simulation based on the mesh solution of the Helmholtz equation for the Fourier transform of pressure perturbation with boundary conditions in the form of the complex impedance. A noise source is placed on the surface surrounding each fan rotor. The acoustic fan power is determined by the acoustic-vortex method, which ensures more accurate decomposition and determination of the pressure pulsation amplitudes in the near field of the fan.

  17. Clinical performance and skill retention after simulation-based education for nephrology fellows.

    PubMed

    Ahya, Shubhada N; Barsuk, Jeffrey H; Cohen, Elaine R; Tuazon, Jennifer; McGaghie, William C; Wayne, Diane B

    2012-07-01

    We previously demonstrated that simulation-based education (SBE) improved temporary hemodialysis catheter (THDC) insertion skills by nephrology fellows. SBE, featuring deliberate practice and rigorous achievement standards, was a powerful method to enhance THDC insertion skills in nephrology fellows. However, experts have called for further research to evaluate skill transfer from the simulated environment to actual clinical care and skill retention. This is a prospective observational cohort study of THDC insertion skills. Twelve nephrology fellows from three academic centers in Chicago were evaluated using a skills checklist from July 2008 to June 2009. Simulator-trained fellows were tested after the SBE intervention and expected to meet or exceed a minimum passing score (MPS) set by an expert panel. To assess transfer of skill to clinical care, three simulator-trained fellows were assessed at 6 months on actual patient THDC insertions using the checklist. To assess retention of skill, 11 of 12 simulator-trained fellows were reassessed at 1 year using the checklist and central venous catheter simulator. Outcomes were determined by THDC insertion skill performance. Simulator-trained fellows scored similarly during 6-month THDC insertions on actual patients and immediate posttest (M = 86.2%, SD = 22.3% vs. M = 93.5%, SD = 5.3%, p = 0.32). However, 1 year after SBE, simulated THDC insertion scores were significantly lower than at immediate posttest (M = 73.4%, SD = 22.2% vs. M = 93.5%, SD = 5.3%, p = 0.01). Our results show that nephrology fellows who completed SBE displayed high levels of performance during THDC insertions on actual patients 6 months later. At 1 year, there was statistically significant skills decay. We recommend booster training at 6 months.

  18. WINE-1: Special-Purpose Computer forN-Body Simulations with a Periodic Boundary Condition

    NASA Astrophysics Data System (ADS)

    Fukushige, Toshiyuki; Makino, Junichiro; Ito, Tomoyoshi; Okumura, Sachiko K.; Ebisuzaki, Toshikazu; Sugimoto, Daiichiro

    1993-06-01

    We have developed WINE-1 (Wave space INtegrator for Ewald method), a special-purpose computer for N-body simulations with a periodic boundary condition. In N-body simulations with a periodic boundary condition such as cosmological N-body simulations, we use the Ewald method to calculate the gravitational interaction. With the Ewald method, we can calculate the interaction more accurately than a calculation with other methods, such as the PM method, the P(3) M method, or the tree algorithm. In the Ewald method, the total force exerted on a particle is divided into contributions from real space and wave-number space so that the infinite sum can converge exponentially in both spaces. WINE is a special-purpose computer used to calculate the interaction in wave-number space. WINE is connected to a host computer via the VME bus. We have developed the first machine, WINE-1. It is made of one board having a size of 38 cm by 40 cm, on which 31 LSI chips and 46 IC chips are wire-wrapped. The peak speed of WINE-1 is equivalent to 480 Mflops. The summation in real space is calculated using a GRAPE system, another special-purpose computer for the direct calculation of the interparticle force. For example, we can perform a cosmological N-body simulation for N=80,000 (500 steps) within a week if we use GRAPE-2A for the summation in real space and WINE-1 for that in wave-number space.

  19. Repression of retinal microvascular endothelial cells by transthyretin under simulated diabetic retinopathy conditions

    PubMed Central

    Shao, Jun; Yao, Yong

    2016-01-01

    AIM To investigate biological effects of transthyretin (TTR) on the development of neovascularization under simulated diabetic retinopathy (DR) condition associated with high glucose and hypoxia. METHODS Human retinal microvascular endothelial cells (hRECs) were cultured in normal and simulated DR environments with high glucose and hypoxia. The normal serum glucose concentration is approximately 5.5 mmol/L; thus, hyperglycemia was simulated with 25 mmol/L glucose, while hypoxia was induced using 200 µmol/L CoCl2. The influence of TTR on hRECs and human retinal pigment epithelial cells (hRPECs) was determined by incubating the cells with 4 µmol/L TTR in normal and abnormal media. A co-culture system was then employed to evaluate the effects of hRPECs on hRECs. RESULTS Decreased hRECs and hRPECs were observed under abnormal conditions, including high-glucose and hypoxic media. In addition, hRECs were significantly inhibited by 4 µmol/L exogenous TTR during hyperglycemic culture. During co-culture, hRPECs inhibited hRECs in both the normal and abnormal environments. CONCLUSION hREC growth is inhibited by exogenous TTR under simulated DR environments with high-glucose and hypoxic, particularly in the medium containing 25 mmol/L glucose. hRPECs, which manufacture TTR in the eye, also represses hRECs in the same environment. TTR is predicted to inhibit the proliferation of hRECs and neovascularization. PMID:27366679

  20. Numerical Simulation of Seepage Field of Tailing Water Channel Under Different Conditions in Operation Period

    NASA Astrophysics Data System (ADS)

    Wang, Feihan; Yan, Guoxin; Chen, Deling

    According to mathematical model of rock and soil, it calculated seepage field of tailing water channel under different conditions. The results showed that under condition of no.1, the seepage discharge from outside to inside of channel is 0.394 m3/h and the discharge under plastic concrete cut-off is 0.358m3/h, and that under condition of no.2, the seepage discharge from outside to inside of channel is 0.249 m3/h and the discharge under plastic concrete cut-off is 0.236m3/h. Under condition of no.1, the outflow of saturation line is at elevation of 411.0m which is under sand and gravel filling layer and near boundary of drift gravel sand layer. Under condition of no.2, the outflow of saturation line is at elevation of 403.0m which is under drift gravel sand layer and near rock foundation. The results showed that numerical simulation can be used to do with seepage problems of tailing water channel.

  1. Microencapsulation of Saccharomyces cerevisiae and its evaluation to protect in simulated gastric conditions

    PubMed Central

    Ghorbani-Choboghlo, Hassan; Zahraei-Salehi, Taghi; Ashrafi-Helan, Javad; Yahyaraeyat, Ramak; Pourjafar, Hadi; Nikaein, Donya; Balal, Asad; Khosravi, Ali-Reza

    2015-01-01

    Background and Objectives: Probiotic yeasts are used in production of functional foods and pharmaceutical products. They play an important role in promoting and maintaining human health. Until now, little work has been published on improving the survival of Saccharomyces in stimulated gastrointestinal condition. Material and Methods: In this study the exposure of the yeast in the capsulate and free forms to artificial gastrointestinal conditions was assessed and the number of viable Saccharomyces cerevisiae cells during 0 to 120 mines in these conditions was evaluated by a pour plate method using sabouraud dextrose agar. Results: Results showed the shape of the beads was generally spherical, sometimes elliptical with a mean diameter of about 50–90 μm. Also count of viable probiotic cells obtained for all the microcapsules were above the recommended levels for a probiotic food. Also decrease of approximately 4 logs was noted in the number of free cells after 2 h of incubation at pH 2 and 8, when compared to decreases of about 2 logs in the all microencapsulated S. cerevisiae under similar conditions. Conclusion: It is concluded that microencapsulation process was significantly able to increase the survival rate of Saccharomyces in a simulated gastrointestinal condition (p<0.05).. PMID:26885335

  2. Choice of In Vivo Versus Idealized Velocity Boundary Conditions Influences Physiologically Relevant Flow Patterns in a Subject-Specific Simulation of Flow in the Human Carotid Bifurcation

    PubMed Central

    Wake, Amanda K.; Oshinski, John N.; Tannenbaum, Allen R.; Giddens, Don P.

    2009-01-01

    Background Accurate fluid mechanics models are important tools for predicting the flow field in the carotid artery bifurcation and for understanding the relationship between hemodynamics and the initiation and progression of atherosclerosis. Clinical imaging modalities can be used to obtain geometry and blood flow data for developing subject-specific, human carotid artery bifurcation models. Method of Approach We developed subject-specific computational fluid dynamics (CFD) models of the human carotid bifurcation from magnetic resonance (MR) geometry data and phase contrast MR (PCMR) velocity data, measured in vivo. Two simulations were conducted with identical geometry, flow rates, and fluid parameters: (1) Simulation 1 used in vivo, measured velocity distributions as time-varying boundary conditions, and (2) Simulation 2 used idealized, fully-developed velocity profiles as boundary conditions. Results The position and extent of negative axial velocity regions (NAVR) vary between the two simulations at any given point in time, and these regions vary temporally within each simulation. The combination of inlet velocity boundary conditions, geometry, and flow waveforms influences NAVRs. In particular, the combination of flow division and the location of the velocity peak with respect to individual carotid geometry landmarks (bifurcation apex position and the departure angle of the IC) influences the size and location of these reversed flow zones. Average axial wall shear stress (WSS) distributions are qualitatively similar for the two simulations; however, instantaneous WSS values vary with the choice of velocity boundary conditions. Conclusions By developing subject-specific simulations from in vivo measured geometry and flow data and varying the velocity boundary conditions in otherwise identical models we isolated the effects of measured versus idealized velocity distributions on blood flow patterns. Choice of velocity distributions at boundary conditions are

  3. Operant conditioning of spinal reflexes: from basic science to clinical therapy.

    PubMed

    Thompson, Aiko K; Wolpaw, Jonathan R

    2014-01-01

    New appreciation of the adaptive capabilities of the nervous system, recent recognition that most spinal cord injuries are incomplete, and progress in enabling regeneration are generating growing interest in novel rehabilitation therapies. Here we review the 35-year evolution of one promising new approach, operant conditioning of spinal reflexes. This work began in the late 1970's as basic science; its purpose was to develop and exploit a uniquely accessible model for studying the acquisition and maintenance of a simple behavior in the mammalian central nervous system (CNS). The model was developed first in monkeys and then in rats, mice, and humans. Studies with it showed that the ostensibly simple behavior (i.e., a larger or smaller reflex) rests on a complex hierarchy of brain and spinal cord plasticity; and current investigations are delineating this plasticity and its interactions with the plasticity that supports other behaviors. In the last decade, the possible therapeutic uses of reflex conditioning have come under study, first in rats and then in humans. The initial results are very exciting, and they are spurring further studies. At the same time, the original basic science purpose and the new clinical purpose are enabling and illuminating each other in unexpected ways. The long course and current state of this work illustrate the practical importance of basic research and the valuable synergy that can develop between basic science questions and clinical needs. PMID:24672441

  4. The relation between type D personality and the clinical condition of patients suffering from psoriasis

    PubMed Central

    Woźniewicz, Agnieszka

    2013-01-01

    Introduction Type D personality is the last distinguished specific type of personality that is characterised by two dimensions: a tendency for feeling negative emotions – depression, anxiety, anger or hostility, and a tendency for withdrawal from the society. The latest research shows the significant role played by type D personality in the aetiology and course of a variety of diseases. Aim The article discusses the problem of the occurrence of type D personality in the group of patients suffering from psoriasis. Diversities in the clinical condition of psoriasis patients due to increasing type D personality traits are specified. Material and methods Ninety psoriasis patients and 86 healthy subjects participated in the research. In the research questionnaires, the scale for assessing increasing psoriasis complaints and the DS-14 scale to assess type D personality were applied. Results Research results made it possible to corroborate more frequent occurrence of type D personality among psoriasis patients. Moreover, it was found that with increasing negative affectivity – one of type D personality components – complaints increase as far as the clinical condition of psoriasis patients is concerned. Conclusions Monitoring of psychological well-being of psoriasis patients, especially within type D personality, seems to be a vital element, irrespective of purely medical treatment. PMID:24494001

  5. Development and implementation of a clinical pathway approach to simulation-based training for foregut surgery

    PubMed Central

    Miyasaka, Kiyoyuki W; Buchholz, Joseph; LaMarra, Denise; Karakousis, Giorgos C; Aggarwal, Rajesh

    2015-01-01

    Introduction Contemporary demands on resident education call for integration of simulation. We designed and implemented a simulation-based curriculum for PGY1 surgery residents to teach technical and non-technical skills within a clinical pathway approach for a foregut surgical patient, from outpatient visit through surgery and post-op follow-up. Methods The three-day curriculum for groups of six residents comprises a combination of standardized patient (SP) encounters, didactic sessions, and hands-on training. The curriculum is underpinned by a summative simulation “pathway” repeated on days 1 and 3. The “pathway” is a series of simulated pre-op, intra-op, and post-op encounters following a single patient through a disease process. The resident sees an SP in clinic presenting with distal gastric cancer, then enters an operating room to perform a gastro-jejunostomy on a porcine tissue model. Finally, the resident engages in a simulated post-operative visit. All encounters are rated by faculty members and the residents themselves, using standardized assessment forms endorsed by the American Board of Surgery. Results 18 first-year residents underwent this curriculum. Faculty ratings of overall operative performance significantly improved following the three-day module. Ratings of preoperative and postoperative performance were not significantly changed in three days. Resident self-ratings significantly improved for all encounters assessed, as did reported confidence in meeting defined learning objectives. Conclusions Conventional surgical simulation training focuses on technical skills in isolation. Our novel “pathway” curriculum targets an important gap in training methodologies by placing both technical and non-technical skills in their clinical context as part of managing a surgical patient. Results indicate consistent improvements in assessments of performance as well as confidence and support its continued usage to educate surgery residents in

  6. Effects of Simulated Mars Conditions on the Survival and Growth of Escherichia coli and Serratia liquefaciens▿

    PubMed Central

    Berry, Bonnie J.; Jenkins, David G.; Schuerger, Andrew C.

    2010-01-01

    Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions. Survival and replication of E. coli and S. liquefaciens cells in liquid medium were evaluated for 7 days under low temperatures (5, 10, 20, or 30°C) with increasing concentrations (0, 5, 10, or 20%) of three salts (MgCl2, MgSO4, NaCl) reported to be present on the surface of Mars. Moderate to high growth rates were observed for E. coli and S. liquefaciens at 30 or 20°C and in solutions with 0 or 5% salts. In contrast, cell densities of both species generally did not increase above initial inoculum levels under the highest salt concentrations (10 and 20%) and the four temperatures tested, with the exception that moderately higher cell densities were observed for both species at 10% MgSO4 maintained at 20 or 30°C. Growth rates of E. coli and S. liquefaciens in low salt concentrations were robust under all pressures (2.5, 10, or 101.3 kPa), exhibiting a general increase of up to 2.5 orders of magnitude above the initial inoculum levels of the assays. Vegetative E. coli cells were maintained in a Mars analog soil for 7 days under simulated Mars conditions that included temperatures between 20 and −50°C for a day/night diurnal period, UVC irradiation (200 to 280 nm) at 3.6 W m−2 for daytime operations (8 h), pressures held at a constant 0.71 kPa, and a gas composition that included the top five gases found in the martian atmosphere. Cell densities of E. coli failed to increase under simulated Mars conditions, and survival was reduced 1 to 2 orders of magnitude by the interactive effects of desiccation, UV

  7. Effects of simulated Mars conditions on the survival and growth of Escherichia coli and Serratia liquefaciens.

    PubMed

    Berry, Bonnie J; Jenkins, David G; Schuerger, Andrew C

    2010-04-01

    Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions. Survival and replication of E. coli and S. liquefaciens cells in liquid medium were evaluated for 7 days under low temperatures (5, 10, 20, or 30 degrees C) with increasing concentrations (0, 5, 10, or 20%) of three salts (MgCl(2), MgSO(4), NaCl) reported to be present on the surface of Mars. Moderate to high growth rates were observed for E. coli and S. liquefaciens at 30 or 20 degrees C and in solutions with 0 or 5% salts. In contrast, cell densities of both species generally did not increase above initial inoculum levels under the highest salt concentrations (10 and 20%) and the four temperatures tested, with the exception that moderately higher cell densities were observed for both species at 10% MgSO(4) maintained at 20 or 30 degrees C. Growth rates of E. coli and S. liquefaciens in low salt concentrations were robust under all pressures (2.5, 10, or 101.3 kPa), exhibiting a general increase of up to 2.5 orders of magnitude above the initial inoculum levels of the assays. Vegetative E. coli cells were maintained in a Mars analog soil for 7 days under simulated Mars conditions that included temperatures between 20 and -50 degrees C for a day/night diurnal period, UVC irradiation (200 to 280 nm) at 3.6 W m(-2) for daytime operations (8 h), pressures held at a constant 0.71 kPa, and a gas composition that included the top five gases found in the martian atmosphere. Cell densities of E. coli failed to increase under simulated Mars conditions, and survival was reduced 1 to 2 orders of magnitude by the interactive

  8. Numerical simulations of the first operational conditions of the negative ion test facility SPIDER

    NASA Astrophysics Data System (ADS)

    Serianni, G.; Agostinetti, P.; Antoni, V.; Baltador, C.; Cavenago, M.; Chitarin, G.; Marconato, N.; Pasqualotto, R.; Sartori, E.; Toigo, V.; Veltri, P.

    2016-02-01

    In view of the realization of the negative ion beam injectors for ITER, a test facility, named SPIDER, is under construction in Padova (Italy) to study and optimize production and extraction of negative ions. The present paper is devoted to the analysis of the expected first operations of SPIDER in terms of single-beamlet and multiple-beamlet simulations of the hydrogen beam optics in various operational conditions. The effectiveness of the methods adopted to compensate for the magnetic deflection of the particles is also assessed. Indications for a sequence of the experimental activities are obtained.

  9. Lower limb cellulitis and its mimics: part II. Conditions that simulate lower limb cellulitis.

    PubMed

    Hirschmann, Jan V; Raugi, Gregory J

    2012-08-01

    Several common conditions can mimic cellulitis, creating a potential for misdiagnosis and incorrect management. The most common disorders mistaken for lower limb cellulitis include venous eczema, lipodermatosclerosis, irritant dermatitis, and lymphedema. The dermatologist is often consulted when a patient has failed to respond to therapy, and a thorough knowledge of the differential diagnosis is essential. This article focuses on entities that can mimic cellulitis, with an emphasis of elements of the history and physical examination that can help to distinguish between lower limb cellulitis and its simulators.

  10. Numerical simulations of the first operational conditions of the negative ion test facility SPIDER.

    PubMed

    Serianni, G; Agostinetti, P; Antoni, V; Baltador, C; Cavenago, M; Chitarin, G; Marconato, N; Pasqualotto, R; Sartori, E; Toigo, V; Veltri, P

    2016-02-01

    In view of the realization of the negative ion beam injectors for ITER, a test facility, named SPIDER, is under construction in Padova (Italy) to study and optimize production and extraction of negative ions. The present paper is devoted to the analysis of the expected first operations of SPIDER in terms of single-beamlet and multiple-beamlet simulations of the hydrogen beam optics in various operational conditions. The effectiveness of the methods adopted to compensate for the magnetic deflection of the particles is also assessed. Indications for a sequence of the experimental activities are obtained. PMID:26932099

  11. Effects of simulated Mars conditions on the survival and growth of Escherichia coli and Serratia liquefaciens.

    PubMed

    Berry, Bonnie J; Jenkins, David G; Schuerger, Andrew C

    2010-04-01

    Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions. Survival and replication of E. coli and S. liquefaciens cells in liquid medium were evaluated for 7 days under low temperatures (5, 10, 20, or 30 degrees C) with increasing concentrations (0, 5, 10, or 20%) of three salts (MgCl(2), MgSO(4), NaCl) reported to be present on the surface of Mars. Moderate to high growth rates were observed for E. coli and S. liquefaciens at 30 or 20 degrees C and in solutions with 0 or 5% salts. In contrast, cell densities of both species generally did not increase above initial inoculum levels under the highest salt concentrations (10 and 20%) and the four temperatures tested, with the exception that moderately higher cell densities were observed for both species at 10% MgSO(4) maintained at 20 or 30 degrees C. Growth rates of E. coli and S. liquefaciens in low salt concentrations were robust under all pressures (2.5, 10, or 101.3 kPa), exhibiting a general increase of up to 2.5 orders of magnitude above the initial inoculum levels of the assays. Vegetative E. coli cells were maintained in a Mars analog soil for 7 days under simulated Mars conditions that included temperatures between 20 and -50 degrees C for a day/night diurnal period, UVC irradiation (200 to 280 nm) at 3.6 W m(-2) for daytime operations (8 h), pressures held at a constant 0.71 kPa, and a gas composition that included the top five gases found in the martian atmosphere. Cell densities of E. coli failed to increase under simulated Mars conditions, and survival was reduced 1 to 2 orders of magnitude by the interactive

  12. Numerical simulation of hyperbolic heat conduction with convection boundary conditions and pulse heating effects

    NASA Technical Reports Server (NTRS)

    Glass, David E.; Tamma, Kumar K.; Railkar, Sudhir B.

    1989-01-01

    The paper describes the numerical simulation of hyperbolic heat conduction with convection boundary conditions. The effects of a step heat loading, a sudden pulse heat loading, and an internal heat source are considered in conjunction with convection boundary conditions. Two methods of solution are presened for predicting the transient behavior of the propagating thermal disturbances. In the first method, MacCormack's predictor-corrector method is employed for integrating the hyperbolic system of equations. Next, the transfinite element method, which employs specially tailored elements, is used for accurately representing the transient response of the propagating thermal wave fronts. The agreement between the results of various numerical test cases validate the representative behavior of the thermal wave fronts. Both methods represent hyperbolic heat conduction behavior by effectively modeling the sharp discontinuities of the propagating thermal disturbances.

  13. 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

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and Earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorping properties of potential constituents is available. The use of theoretically derived microwave absorption properties for such atmospheric constituents, or laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurement of the microwave properties of atmospheric gases under simulated conditions for the outer planets were conducted. Results of these measurements are discussed.

  14. Corrosion of iron, aluminum and copper-base alloys in glycols under simulated solar collector conditions

    SciTech Connect

    Beavers, J.A.; Diegle, R.B.

    1981-10-01

    The corrosion behavior of iron, aluminum and copperbase alloys was studied in uninhibited glycol solutions under conditions that simulate those found in non-concentrating solar collectors. It was found that only Type 444 stainless steel exhibited adequate corrosion resistance; there was no evidence of pitting, crevice corrosion, or galvanic attack, and general corrosion rates were low. The general corrosion rate of CDA 122 copper was high (greater than 200 ..mu..m/y) under some test conditions, but copper was resistant to pitting and crevice attack. General corrosion rates of the aluminum alloys (1100, 3003 and 6061) were low, but these alloys were susceptible to pitting and crevice attack. The propensity for pitting was greatest in the presence of chlorides but it also was severe in the absence of chlorides following long exposures. The onset of pitting of the aluminum alloys in chloride-free solutions was attributed to degradation of the glycols.

  15. On simulating lipid bilayers with an applied surface tension: periodic boundary conditions and undulations.

    PubMed Central

    Feller, S E; Pastor, R W

    1996-01-01

    As sketched in Fig. 1, a current molecular dynamics computer simulation of a lipid bilayer fails to capture significant features of the macroscopic system, including long wavelength undulations. Such fluctuations are intrinsically connected to the value of the macroscopic (or thermodynamic) surface tension (cf. Eqs. 1 and 9; for a related treatment, see Brochard et al., 1975, 1976). Consequently, the surface tension that might be evaluated in an MD simulation should not be expected to equal the surface tension obtained from macroscopic measurements. Put another way, the largest of the three simulations presented here contained over 16,000 atoms and required substantial computer time to complete, but modeled a system of only 36 lipids per side. From this perspective it is not surprising that the system is not at the thermodynamic limit. An important practical consequence of this effect is that simulations with fluctuating area should be carried out with a nonzero applied surface tension (gamma 0 of Fig. 2) even when the macroscopic tension is zero, or close to zero. Computer simulations at fixed surface area, which can explicitly determine pressure anisotropy at the molecular level, should ultimately lend insight into the value of gamma 0, including its dependence on lipid composition and other membrane components. As we have noted and will describe further in separate publications (Feller et al., 1996; Feller et al., manuscript in preparation), surface tensions obtained from simulations can be distorted by inadequate initial conditions and convergence, and are sensitive to potential energy functions, force truncation methods, and system size; it is not difficult, in fact, to tune terms in the potential energy function so as to yield surface tensions close to zero. This is why parameters should be tested extensively on simpler systems, for example, monolayers. The estimates of gamma 0 that we have presented here should be regarded as qualitative, and primarily

  16. On simulating lipid bilayers with an applied surface tension: periodic boundary conditions and undulations.

    PubMed

    Feller, S E; Pastor, R W

    1996-09-01

    As sketched in Fig. 1, a current molecular dynamics computer simulation of a lipid bilayer fails to capture significant features of the macroscopic system, including long wavelength undulations. Such fluctuations are intrinsically connected to the value of the macroscopic (or thermodynamic) surface tension (cf. Eqs. 1 and 9; for a related treatment, see Brochard et al., 1975, 1976). Consequently, the surface tension that might be evaluated in an MD simulation should not be expected to equal the surface tension obtained from macroscopic measurements. Put another way, the largest of the three simulations presented here contained over 16,000 atoms and required substantial computer time to complete, but modeled a system of only 36 lipids per side. From this perspective it is not surprising that the system is not at the thermodynamic limit. An important practical consequence of this effect is that simulations with fluctuating area should be carried out with a nonzero applied surface tension (gamma 0 of Fig. 2) even when the macroscopic tension is zero, or close to zero. Computer simulations at fixed surface area, which can explicitly determine pressure anisotropy at the molecular level, should ultimately lend insight into the value of gamma 0, including its dependence on lipid composition and other membrane components. As we have noted and will describe further in separate publications (Feller et al., 1996; Feller et al., manuscript in preparation), surface tensions obtained from simulations can be distorted by inadequate initial conditions and convergence, and are sensitive to potential energy functions, force truncation methods, and system size; it is not difficult, in fact, to tune terms in the potential energy function so as to yield surface tensions close to zero. This is why parameters should be tested extensively on simpler systems, for example, monolayers. The estimates of gamma 0 that we have presented here should be regarded as qualitative, and primarily

  17. Validation of a Monte Carlo model used for simulating tube current modulation in computed tomography over a wide range of phantom conditions/challenges

    SciTech Connect

    Bostani, Maryam McMillan, Kyle; Cagnon, Chris H.; McNitt-Gray, Michael F.; DeMarco, John J.

    2014-11-01

    Purpose: Monte Carlo (MC) simulation methods have been widely used in patient dosimetry in computed tomography (CT), including estimating patient organ doses. However, most simulation methods have undergone a limited set of validations, often using homogeneous phantoms with simple geometries. As clinical scanning has become more complex and the use of tube current modulation (TCM) has become pervasive in the clinic, MC simulations should include these techniques in their methodologies and therefore should also be validated using a variety of phantoms with different shapes and material compositions to result in a variety of differently modulated tube current profiles. The purpose of this work is to perform the measurements and simulations to validate a Monte Carlo model under a variety of test conditions where fixed tube current (FTC) and TCM were used. Methods: A previously developed MC model for estimating dose from CT scans that models TCM, built using the platform of MCNPX, was used for CT dose quantification. In order to validate the suitability of this model to accurately simulate patient dose from FTC and TCM CT scan, measurements and simulations were compared over a wide range of conditions. Phantoms used for testing range from simple geometries with homogeneous composition (16 and 32 cm computed tomography dose index phantoms) to more complex phantoms including a rectangular homogeneous water equivalent phantom, an elliptical shaped phantom with three sections (where each section was a homogeneous, but different material), and a heterogeneous, complex geometry anthropomorphic phantom. Each phantom requires varying levels of x-, y- and z-modulation. Each phantom was scanned on a multidetector row CT (Sensation 64) scanner under the conditions of both FTC and TCM. Dose measurements were made at various surface and depth positions within each phantom. Simulations using each phantom were performed for FTC, detailed x–y–z TCM, and z-axis-only TCM to obtain

  18. Atomistic Simulations of Chemical Reactivity of TATB Under Thermal and Shock Conditions

    SciTech Connect

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

    2009-09-23

    The study of chemical transformations that occur at the reactive shock front of energetic materials provides important information for the development of predictive models at the grain-and continuum scales. A major shortcoming of current high explosives models is the lack of chemical kinetics data of the reacting explosive in the high pressure and temperature regimes. In the absence of experimental data, long-time scale atomistic molecular dynamics simulations with reactive chemistry become a viable recourse to provide an insight into the decomposition mechanism of explosives, and to obtain effective reaction rate laws. These rates can then be incorporated into thermo-chemical-hydro codes (such as Cheetah linked to ALE3D) for accurate description of the grain and macro scales dynamics of reacting explosives. In this talk, I will present quantum simulations of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) crystals under thermal decomposition (high density and temperature) and shock compression conditions. This is the first time that condensed phase quantum methods have been used to study the chemistry of insensitive high explosives. We used the quantum-based, self-consistent charge density functional tight binding method (SCC{_}DFTB) to calculate the interatomic forces for reliable predictions of chemical reactions, and to examine electronic properties at detonation conditions for a relatively long time-scale on the order of several hundreds of picoseconds. For thermal decomposition of TATB, we conducted constant volume-temperature simulations, ranging from 0.35 to 2 nanoseconds, at {rho} = 2.87 g/cm{sup 3} at T = 3500, 3000, 2500, and 1500 K, and {rho} = 2.9 g/cm{sup 3} and 2.72 g/cm{sup 3}, at T = 3000 K. We also simulated crystal TATB's reactivity under steady overdriven shock compression using the multi-scale shock technique. We conducted shock simulations with specified shock speeds of 8, 9, and 10 km/s for up to 0.43 ns duration, enabling us to track the

  19. [The clinical condition and treatment of diseases associated with sudden death].

    PubMed

    Sawamura, Atsushi; Katabami, Ken-ichi; Ishimori, Naoki; Singu, Yasuei; Nakayama, Naoki

    2016-05-01

    The Hokkaido Medical Society is a group of doctors and medical researchers in Hokkaido. Its purpose is to contribute to medicine and to the improvement of medical treatment. This symposium was carried out in order to inform citizens about the condition known as sudden death. We hypothesize that the incidence of sudden death tends to increase in line with the incidence of metabolic syndrome. Approximately four hundred patients were transported to our hospital by ambulance in a state of cardiopulmonary arrest (CPA) last year. The number of CPA patients who are treated in our hospital has increased in comparison to the previous decade. The theme of this year is "The clinical condition and treatment of diseases associated with sudden death" in view of the above mentioned situation. In 2015, it was reported that sudden death occurred in an American pilot and that the co-pilot was forced to make an emergency landing. Interestingly, sudden death can ever sometimes occur in pilots who undergo regular physical examinations. Numerous diseases and conditions are associated with sudden death, including: acute myocardial infarction, irregular pulse, cardiac insufficiency, cerebrovascular disease, aortic dissection and choking. We are of the opinion that the frequency of sudden death is very high in the fields of emergency medicine, cardiovascular medicine, cardiovascular surgery and neurosurgery. In this symposium, we presented and explained the condition that is known as sudden death and the current state of treatment of sudden death in emergency medicine, cardiovascular medicine, cardiovascular surgery and neurosurgery departments of the Hokkaido University Graduate School of Medicine in October, 2015. We hope that the symposium will help the citizen audience to understand the condition and treatment of sudden death, and also to help prevent sudden death.

  20. 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. PMID:11540667

  1. Spinal muscle activity in simulated rugby union scrummaging is affected by different engagement conditions.

    PubMed

    Cazzola, D; Stone, B; Holsgrove, T P; Trewartha, G; Preatoni, E

    2016-04-01

    Biomechanical studies of rugby union scrummaging have focused on kinetic and kinematic analyses, while muscle activation strategies employed by front-row players during scrummaging are still unknown. The aim of the current study was to investigate the activity of spinal muscles during machine and live scrums. Nine male front-row forwards scrummaged as individuals against a scrum machine under "crouch-touch-set" and "crouch-bind-set" conditions, and against a two-player opposition in a simulated live condition. Muscle activities of the sternocleidomastoid, upper trapezius, and erector spinae were measured over the pre-engagement, engagement, and sustained-push phases. The "crouch-bind-set" condition increased muscle activity of the upper trapezius and sternocleidomastoid before and during the engagement phase in machine scrummaging. During the sustained-push phase, live scrummaging generated higher activities of the erector spinae than either machine conditions. These results suggest that the pre-bind, prior to engagement, may effectively prepare the cervical spine by stiffening joints before the impact phase. Additionally, machine scrummaging does not replicate the muscular demands of live scrummaging for the erector spinae, and for this reason, we advise rugby union forwards to ensure scrummaging is practiced in live situations to improve the specificity of their neuromuscular activation strategies in relation to resisting external loads. PMID:25818526

  2. The effect of simulated air conditions on N95 filtering facepiece respirators performance.

    PubMed

    Ramirez, Joel A; O'Shaughnessy, Patrick T

    2016-07-01

    The objective of this study was to determine the effect of several simulated air environmental conditions on the particle penetration and the breathing resistance of two N95 filtering facepiece respirator (FFR) models. The particle penetration and breathing resistance of the respirators were evaluated in a test system developed to mimic inhalation and exhalation breathing while relative humidity and temperature were modified. Breathing resistance was measured over 120 min using a calibrated pressure transducer under four different temperature and relative humidity conditions without aerosol loading. Particle penetration was evaluated before and after the breathing resistance test at room conditions using a sodium chloride aerosol measured with a scanning mobility particle sizer. Results demonstrated that increasing relative humidity and lowering external temperature caused significant increases in breathing resistance (p < 0.001). However, these same conditions did not influence the penetration or most penetrating particle size of the tested FFRs. The increase in breathing resistance varied by FFR model suggesting that some FFR media are less influenced by high relative humidity. PMID:26861653

  3. The effect of simulated air conditions on N95 filtering facepiece respirators performance.

    PubMed

    Ramirez, Joel A; O'Shaughnessy, Patrick T

    2016-07-01

    The objective of this study was to determine the effect of several simulated air environmental conditions on the particle penetration and the breathing resistance of two N95 filtering facepiece respirator (FFR) models. The particle penetration and breathing resistance of the respirators were evaluated in a test system developed to mimic inhalation and exhalation breathing while relative humidity and temperature were modified. Breathing resistance was measured over 120 min using a calibrated pressure transducer under four different temperature and relative humidity conditions without aerosol loading. Particle penetration was evaluated before and after the breathing resistance test at room conditions using a sodium chloride aerosol measured with a scanning mobility particle sizer. Results demonstrated that increasing relative humidity and lowering external temperature caused significant increases in breathing resistance (p < 0.001). However, these same conditions did not influence the penetration or most penetrating particle size of the tested FFRs. The increase in breathing resistance varied by FFR model suggesting that some FFR media are less influenced by high relative humidity.

  4. DSMC Simulation of Separated Flows About Flared Bodies at Hypersonic Conditions

    NASA Technical Reports Server (NTRS)

    Moss, James N.

    2000-01-01

    This paper describes the results of a numerical study of interacting hypersonic flows at conditions that can be produced in ground-based test facilities. The computations are made with the direct simulation Monte Carlo (DSMC) method of Bird. The focus is on Mach 10 flows about flared axisymmetric configurations, both hollow cylinder flares and double cones. The flow conditions are those for which experiments have been or will be performed in the ONERA R5Ch low-density wind tunnel and the Calspan-University of Buffalo Research Center (CUBRC) Large Energy National Shock (LENS) tunnel. The range of flow conditions, model configurations, and model sizes provides a significant range of shock/shock and shock/boundary layer interactions at low Reynolds number conditions. Results presented will highlight the sensitivity of the calculations to grid resolution, contrast the differences in flow structure for hypersonic cold flows and those of more energetic but still low enthalpy flows, and compare the present results with experimental measurements for surface heating, pressure, and extent of separation.

  5. Simulation of VSPT Experimental Cascade Under High and Low Free-Stream Turbulence Conditions

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.; Giel, Paul W.; Flegel, Ashlie B.

    2014-01-01

    Variable-Speed Power Turbines (VSPT) for rotorcraft applications operate at low Reynolds number and over a wide range in incidence associated with shaft speed change. A comprehensive linear cascade data set obtained includes the effects of Reynolds number, free-stream turbulence and incidence is available and this paper concerns itself with the presentation and numerical simulation of conditions resulting in a selected set of those data. As such, post-dictions of blade pressure loading, total-pressure loss and exit flow angles under conditions of high and low turbulence intensity for a single Reynolds number are presented. Analyses are performed with the three-equation turbulence models of Walters-Leylek and Walters and Cokljat. Transition, loading, total-pressure loss and exit angle variations are presented and comparisons are made with experimental data as available. It is concluded that at the low freestream turbulence conditions the Walters-Cokljat model is better suited to predictions while for high freestream conditions the two models generate similar predications that are generally satisfactory.

  6. Simulation of VSPT Experimental Cascade Under High and Low Free-Stream Turbulence Conditions

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.; Giel, Paul W.; Flegel, Ashlie B.

    2015-01-01

    Variable-Speed Power Turbines (VSPT) for rotorcraft applications operate at low Reynolds number and over a wide range in incidence associated with shaft speed change. A comprehensive linear cascade data set obtained includes the effects of Reynolds number, free-stream turbulence and incidence is available and this paper concerns itself with the presentation and numerical simulation of conditions resulting in a selected set of those data. As such, post-dictions of blade pressure loading, total-pressure loss and exit flow angles under conditions of high and low turbulence intensity for a single Reynolds number are presented. Analyses are performed with the three-equation turbulence models of Walters- Leylek and Walters and Cokljat. Transition, loading, total-pressure loss and exit angle variations are presented and comparisons are made with experimental data as available. It is concluded that at the low freestream turbulence conditions the Walters-Cokljat model is better suited to predictions while for high freestream conditions the two models generate similar predications that are generally satisfactory.

  7. 3-D simulation of gases transport under condition of inert gas injection into goaf

    NASA Astrophysics Data System (ADS)

    Liu, Mao-Xi; Shi, Guo-Qing; Guo, Zhixiong; Wang, Yan-Ming; Ma, Li-Yang

    2016-02-01

    To prevent coal spontaneous combustion in mines, it is paramount to understand O2 gas distribution under condition of inert gas injection into goaf. In this study, the goaf was modeled as a 3-D porous medium based on stress distribution. The variation of O2 distribution influenced by CO2 or N2 injection was simulated based on the multi-component gases transport and the Navier-Stokes equations using Fluent. The numerical results without inert gas injection were compared with field measurements to validate the simulation model. Simulations with inert gas injection show that CO2 gas mainly accumulates at the goaf floor level; however, a notable portion of N2 gas moves upward. The evolution of the spontaneous combustion risky zone with continuous inert gas injection can be classified into three phases: slow inerting phase, rapid accelerating inerting phase, and stable inerting phase. The asphyxia zone with CO2 injection is about 1.25-2.4 times larger than that with N2 injection. The efficacy of preventing and putting out mine fires is strongly related with the inert gas injecting position. Ideal injections are located in the oxidation zone or the transitional zone between oxidation zone and heat dissipation zone.

  8. Rarefied hypersonic flow simulations using the Navier-Stokes equations with non-equilibrium boundary conditions

    NASA Astrophysics Data System (ADS)

    Greenshields, Christopher J.; Reese, Jason M.

    2012-07-01

    This paper investigates the use of Navier-Stokes-Fourier equations with non-equilibrium boundary conditions (BCs) for simulation of rarefied hypersonic flows. It revisits a largely forgotten derivation of velocity slip and temperature jump by Patterson, based on Grad's moment method. Mach 10 flow around a cylinder and Mach 12.7 flow over a flat plate are simulated using both computational fluid dynamics using the temperature jump BCs of Patterson and Smoluchowski and the direct simulation Monte-Carlo (DSMC) method. These flows exhibit such strongly non-equilibrium behaviour that, following Patterson's analysis, they are strictly beyond the range of applicability of the BCs. Nevertheless, the results using Patterson's temperature jump BC compare quite well with the DSMC and are consistently better than those using the standard Smoluchowski temperature jump BC. One explanation for this better performance is that an assumption made by Patterson, based on the flow being only slightly non-equilibrium, introduces an additional constraint to the resulting BC model in the case of highly non-equilibrium flows.

  9. Large eddy simulation of the influence of CCN and thermodynamic conditions on marine stratocumulus cloud development

    NASA Astrophysics Data System (ADS)

    Song, K.; Yum, S. S.

    2009-09-01

    The marine stratocumulus topped boundary layer, which prevails in the subtropical oceanic regions where the subsidence inversion associated with the descending branch of the Hadley-Walker cell dominates, is thought to be an important component of the climate system. High albedo (30-40%) of stratocumulus clouds compared to the ocean background (10%) gives rise to large deficits in the absorbed solar radiation flux. Since cloud radiative properties are highly dependent on cloud microphysical properties, which are in turn dependent on the cloud condensation nuclei (CCN) distribution, understanding the influence of anthropogenic CCN on cloud microphysics and dynamics is a key to accurately assess the climatic impact of marine stratocumulus clouds. A large eddy simulation (LES) model is good for studying stratocumulus clouds in the boundary layer because it explicitly resolves turbulent scale eddies and can provide information on detailed microphysical structure that is difficult to be measured over the ocean. We employ the CIMMS (Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma) 3D LES model with explicit bin microphysics. We examine the microphysical and dynamical evolution of stratocumulus clouds under different CCN loadings for four different thermodynamic conditions (the key differences are in moisture content and temperature inversion height). Contrasting results of daytime and nocturnal simulations are also examined. Three different measured CCN spectra that represent maritime, continental, and polluted air masses are used as input CCN spectra for the model; the concentrations at 1% supersaturation are 163, 1023, and 5292 cm-3, respectively. The grid spacing is 75 m in the horizontal and 25 m in the vertical, to make the total domain size of 3×3×1.25 km. Total simulation time is 6 hrs. The large-scale subsidence is prescribed by w= -Dz, where the large-scale divergence D = 5×10-6 s-1 is assumed. For the clouds formed under

  10. Thermal resistance of attic loose-fill insulations decreases under simulated winter conditions

    SciTech Connect

    Graves, R.S.; Wilkes, K.E.; McElroy, D.L.

    1994-05-01

    Two absolute techniques were used to measure the thermal resistance of attic loose-fill insulations: the Large Scale Climate Simulator (LSCS) and the Unguarded Thin-Heater Apparatus (UTHA). Two types of attic loose-fill insulations (unbonded and bonded/cubed) were tested under simulated winter conditions. To simulate winter conditions for an attic insulation, the specimens were tested with heat flow up, large temperature differences, and an air gap. The specimens were tested either with a constant mean temperature (30 or 21{degrees}C) and an increasing temperature difference or with a constant base temperature (21{degrees}C) and an increasing temperature difference (i.e., a decreasing mean temperature). The UTHA test specimens had a nominal thickness of 0.2 m of loose-fill insulation. The LSCS test specimens had a nominal thickness of 0.3 m of loose-fill insulation contained in a 4.2 by 5 m attic test module with a gypsum board base. The module had a gabled attic with a 5 in 12 slope roof. The tests yielded the surface-to-surface thermal resistance, R, which includes the thermal resistance due to gypsum, insulation, and any wood joists. Tests with and without an air gap were conducted in the UTHA. Surface-to-surface thermal resistance results from the LSCS and the UTHA show similar trends for these two types of loose-fill insulation when tested under simulated winter conditions. Tests with no air gap gave values of R that agreed with the bag label R-value for the insulations; R increased with lower mean temperatures. These no-gap values of R were 2 to 5% greater than the values of R obtained with an air gap for temperature differences of less than 22{degrees}C. For larger temperature differences R decreased, and at temperature differences of over 40{degrees}C, the R values were 50% less than those at small temperature differences.

  11. The Fuel Accident Condition Simulator (FACS) furnace system for high temperature performance testing of VHTR fuel

    SciTech Connect

    Paul A. Demkowicz; David V. Laug; Dawn M. Scates; Edward L. Reber; Lyle G. Roybal; John B. Walter; Jason M. Harp; Robert N. Morris

    2012-10-01

    The AGR-1 irradiation of TRISO-coated particle fuel specimens was recently completed and represents the most successful such irradiation in US history, reaching peak burnups of greater than 19% FIMA with zero failures out of 300,000 particles. An extensive post-irradiation examination (PIE) campaign will be conducted on the AGR-1 fuel in order to characterize the irradiated fuel properties, assess the in-pile fuel performance in terms of coating integrity and fission metals release, and determine the fission product retention behavior during high temperature safety testing. A new furnace system has been designed, built, and tested to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000 degrees C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, and Eu), iodine, and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator furnace system and the associated fission gas monitoring system, as well as preliminary system calibration results.

  12. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1997-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements completed under this grant (NAGW-533), have shown that the opacity from, SO2 under simulated Venus conditions is best described by a different lineshape than was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  13. Sunset decay of the convective turbulence with Large-Eddy Simulation under realistic conditions

    NASA Astrophysics Data System (ADS)

    Rizza, U.; Miglietta, M. M.; Degrazia, G. A.; Acevedo, O. C.; Marques Filho, E. P.

    2013-10-01

    Large-Eddy Simulation is performed for a single day from the Cooperative Atmosphere-Surface Exchange Study (CASES-99) field program. This study investigates an observed case of evening transition boundary layer over land. Parameters of the ambient atmosphere in the LES-decay studies conducted so far were typically prescribed in an idealized form. To provide suitable data under the wide range of the PBL weather conditions, the LES should be able to adequately reproduce the PBL turbulence dynamics including-if possible-baroclinicity, radiation, large scale advection and not only be related to a decreasing surface heating. In addition LES-decay studies usually assume that the sensible heat flux decreases instantaneously or with a very short time scale. The main purpose of this investigation is to study the decay of boundary-layer average turbulent kinetic energy at sunset with Large-Eddy Simulation that is forced with realistic environment conditions. This allows investigating the Turbulent Kinetic Energy decay over the realistic time scale that is observed in the atmosphere. During the intermediate and last stage of decay of the boundary-layer average Turbulent Kinetic Energy the exponents of the decay power law t go from 2 to 6, as evidenced by experimental results and recent analytical modeling in the surface layer.

  14. A dynamic slip boundary condition for wall-modeled large-eddy simulation

    NASA Astrophysics Data System (ADS)

    Bose, S. T.; Moin, P.

    2014-01-01

    Wall models for large-eddy simulation (LES) are a necessity to remove the prohibitive resolution requirements of near-wall turbulence in high Reynolds turbulent flows. Traditional wall models often rely on assumptions about the local state of the boundary layer (e.g., logarithmic velocity profiles) and require a priori prescription of tunable model coefficients. In the present study, a slip velocity boundary condition for the filtered velocity field is obtained from the derivation of the LES equations using a differential filter. A dynamic procedure for the local slip length is additionally formulated making the slip velocity wall model free of any a priori specified coefficients. The accuracy of the dynamic slip velocity wall model is tested in a series of turbulent channel flows at varying Reynolds numbers and in the LES of a National Advisory Committee for Aeronautics (NACA) 4412 airfoil at near-stall conditions. The wall-modeled simulations are able to accurately predict mean flow characteristics, including the formation of a trailing-edge separation bubble in NACA 4412 configuration. The validation cases demonstrate the effectiveness of this wall-modeling approach in both attached and separated flow regimes.

  15. Physico-chemical characterization of steel slag. Study of its behavior under simulated environmental conditions.

    PubMed

    Navarro, Carla; Díaz, Mario; Villa-García, María A

    2010-07-15

    The chemical and mineralogical composition of steel slag produced in two ArcelorMittal steel plants located in the North of Spain, as well as the study of the influence of simulated environmental conditions on the properties of the slag stored in disposal areas, was carried out by elemental chemical analysis, XRF, X-ray diffraction, thermal analysis, and scanning electron microscopy with EDS analyzer. Spectroscopic characterization of the slag was also performed by using FTIR spectroscopy. Due to the potential uses of the slag as low cost adsorbent for water treatment and pollutants removal, its detailed textural characterization was carried out by nitrogen adsorption-desorption at 77 K and mercury intrusion porosimetry. The results show that the slag is a crystalline heterogeneous material whose main components are iron oxides, calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate), elemental iron, and quartz. The slags are porous materials with specific surface area of 11 m(2)g(-1), containing both mesopores and macropores. Slag exposure to simulated environmental conditions lead to the formation of carbonate phases. Carbonation reduces the leaching of alkaline earth elements as well as the release of the harmful trace elements Cr (VI) and V. Steel slags with high contents of portlandite and calcium silicates are potential raw materials for CO(2) long-term storage. PMID:20568743

  16. Effects of wearing compression garments on thermoregulation during simulated team sport activity in temperate environmental conditions.

    PubMed

    Houghton, Laurence A; Dawson, Brian; Maloney, Shane K

    2009-03-01

    Anecdotal evidence suggests compression garments (CGs) are being worn underneath normal playing attire during team sports. Wearing CGs as a baselayer could possibly increase heat storage, and so this field study investigated the effects of wearing CGs, comprising knee-length shorts and short-sleeved top underneath normal match-day attire (COMP), versus normal match-day attire alone (NORM) on thermoregulation during simulated team sport activity. Ten match-fit field hockey players twice performed 4x15min exercise bouts consisting of repeated cycles of intermittent, varied-intensity 20m shuttle running (Loughborough intermittent shuttle test), once in COMP and once in NORM. Testing was conducted in an indoor gymnasium (ambient conditions: approximately 17 degrees C, approximately 60% relative humidity). Participants acted as their own controls. Heart rate (HR), 15m sprint time, ratings of perceived exertion (RPE), blood lactate concentration, sweat rate and body core temperature (T(core)) were similar between trials (p>0.05). Mean skin temperature (T(skin)) was significantly higher in COMP than NORM (p<0.05). Overall, CGs worn as a baselayer during simulated team sport exercise in temperate ambient conditions had no thermoregulatory benefits nor any detrimental effects on T(core), physiological performance or dehydration. However, the higher T(skin) may affect individual preference for wearing CGs as an undergarment during team sports.

  17. Physico-chemical characterization of steel slag. Study of its behavior under simulated environmental conditions.

    PubMed

    Navarro, Carla; Díaz, Mario; Villa-García, María A

    2010-07-15

    The chemical and mineralogical composition of steel slag produced in two ArcelorMittal steel plants located in the North of Spain, as well as the study of the influence of simulated environmental conditions on the properties of the slag stored in disposal areas, was carried out by elemental chemical analysis, XRF, X-ray diffraction, thermal analysis, and scanning electron microscopy with EDS analyzer. Spectroscopic characterization of the slag was also performed by using FTIR spectroscopy. Due to the potential uses of the slag as low cost adsorbent for water treatment and pollutants removal, its detailed textural characterization was carried out by nitrogen adsorption-desorption at 77 K and mercury intrusion porosimetry. The results show that the slag is a crystalline heterogeneous material whose main components are iron oxides, calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate), elemental iron, and quartz. The slags are porous materials with specific surface area of 11 m(2)g(-1), containing both mesopores and macropores. Slag exposure to simulated environmental conditions lead to the formation of carbonate phases. Carbonation reduces the leaching of alkaline earth elements as well as the release of the harmful trace elements Cr (VI) and V. Steel slags with high contents of portlandite and calcium silicates are potential raw materials for CO(2) long-term storage.

  18. Structural analysis of rat bone explants kept in vitro in simulated microgravity conditions.

    PubMed

    Cosmi, F; Steimberg, N; Dreossi, D; Mazzoleni, G

    2009-04-01

    Skeletal abnormalities reported in humans and laboratory animals after spaceflight, include cancellous osteopenia, decreased cortical and cancellous bone formation, aberrant matrix ultrastructure, decreased mineralization and reduced bone strength. Although considerable effort has been made up to now to understand the skeletal effects of spaceflight, in order to estimate health risk, our knowledge in this area is still largely incomplete. It is widely accepted that the mechanical strength of cancellous bone is related not only to the mineral content, but also to the trabecular micro-architecture arrangement. Three-dimensional numerical analysis of bone volumes has been shown to be an important tool in this field. The Cell Method, a recently introduced numerical method, has been applied to static analysis of structures obtained from 3D reconstruction of micro-computed tomography scans performed at the Elettra Synchrotron facility (Trieste, Italy) in order to quantify changes in trabecular bone architecture. In the present study, the Cell Method model is used to compare the micro-tomographed structure of fragments of rats bone explants (tibial proximal epiphyses) harvested after 3 days and after 1, 2, 3 and 4 weeks of culture in the RCCS bioreactor, which represents the unique existing bioreactor, operating on the Earth's surface, capable of successfully reproducing, in vitro, optimal conditions in order to simulate a microgravity environment. Although preliminary, our results seem to suggest that the exposure of tibial bone explants to simulated microgravity conditions obtained by the RCCS bioreactor, are consistent with skeletal changes observed after spaceflight. PMID:19627820

  19. Behaviour of various glass-ceramic sealants with ferritic steels under simulated SOFC stack conditions

    NASA Astrophysics Data System (ADS)

    Haanappel, V. A. C.; Shemet, V.; Gross, S. M.; Koppitz, Th.; Menzler, N. H.; Zahid, M.; Quadakkers, W. J.

    The suitability of various combinations of glass-ceramic sealants with high-chromium ferritic steels under conditions simulating SOFC stacks has been evaluated, i.e. three glass-ceramic sealants and seven types of ferritic steels. The test method used is based on test samples consisting of two metallic sheets, joined together with a glass-ceramic sealant. The outer side of the specimens was exposed to air for 400 h at 800 °C, whereas the inner side was exposed to hydrogen saturated with 3 vol.% water vapour. In particular, attention is paid to the influence of small amounts of additives to both the glass-ceramic sealant and the steel on the electrical and chemical behaviour of the specimens. Under experimental conditions simulating SOFC stacks, it appeared that excessive internal Cr oxidation of the ferritic steels, sometimes accompanied by external Fe-oxide formation, only occurred in the case of glass-ceramics containing minor amounts of PbO. This internal oxidation finally resulted in a volume change of the ferritic steel, which was manifested in bulging of the steel. As a consequence, the glass-ceramic was pushed away from the steel surface and crack formation at the glass-ceramic-steel interface occurred. The rate of corrosion attack strongly depended on the detailed steel composition. Increasing Si content apparently increased the rate of the corrosion attack, and thus possibly decreasing the time for the occurrence of short-circuiting.

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

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1988-01-01

    In the first half of this grant year, laboratory measurements were conducted on the millimeter-wave properties of atmospheric gases under simulated conditions for the outer planet. Significant improvements in the current system have made it possible to accurately characterize the opacity from gaseous NH3 at longer millimeter wavelengths (7 to 10 mm) under simulated Jovian conditions. In the second half of the grant year, it is hoped to extend such measurements to even shorter millimeter-wavelengths. Further analysis and application of the laboratory results to microwave and millimeter-wave absorption data for the outer planets, such as results from Voyager Radio Occultation experiments and earth-based radio astronomical observations will be continued. The analysis of available multispectral microwave opacity data from Venus, including data from the most recent radio astronomical ovservations in the 1.3 to 3.6 cm wavelength range and newly obtained Pioneer-Venus Radio Occulatation measurements at 13 cm, using the laboratory measurements as an interpretative tool will be pursued.

  1. Fuel Accident Condition Simulator (FACS) Furnace for Post-Irradiation Heating Tests of VHTR Fuel Compacts

    SciTech Connect

    Paul A Demkowicz; Paul Demkowicz; David V Laug

    2010-10-01

    Abstract –Fuel irradiation testing and post-irradiation examination are currently in progress as part of the Next Generation Nuclear Plant Fuels Development and Qualification Program. The PIE campaign will include extensive accident testing of irradiated very high temperature reactor fuel compacts to verify fission product retention characteristics at high temperatures. This work will be carried out at both the Idaho National Laboratory (INL) and the Oak Ridge National Laboratory, beginning with accident tests on irradiated fuel from the AGR-1 experiment in 2010. A new furnace system has been designed, built, and tested at INL to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000°C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, Eu, and I) and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator (FACS) furnace system, as well as preliminary system calibration results.

  2. Mechanical Behavior of Tissue Simulants and Soft Tissues Under Extreme Loading Conditions

    NASA Astrophysics Data System (ADS)

    Kalcioglu, Zeynep Ilke

    Recent developments in computer-integrated surgery and in tissue-engineered constructs necessitate advances in experimental and analytical techniques in characterizing properties of mechanically compliant materials such as gels and soft tissues, particularly for small sample volumes. One goal of such developments is to quantitatively predict and mimic tissue deformation due to high rate impact events typical of industrial accidents and ballistic insults. This aim requires advances in mechanical characterization to establish tools and design principles for tissue simulant materials that can recapitulate the mechanical responses of hydrated soft tissues under dynamic contact-loading conditions. Given this motivation, this thesis studies the mechanical properties of compliant synthetic materials developed for tissue scaffold applications and of soft tissues, via modifying an established contact based technique for accurate, small scale characterization under fully hydrated conditions, and addresses some of the challenges in the implementation of this method. Two different engineered material systems composed of physically associating block copolymer gels, and chemically crosslinked networks including a solvent are presented as potential tissue simulants for ballistic applications, and compared directly to soft tissues from murine heart and liver. In addition to conventional quasistatic and dynamic bulk mechanical techniques that study macroscale elastic and viscoelastic properties, new methodologies are developed to study the small scale mechanical response of the aforementioned material systems to concentrated impact loading. The resistance to penetration and the energy dissipative constants are quantified in order to compare the deformation of soft tissues and mechanically optimized simulants, and to identify the underlying mechanisms by which the mechanical response of these tissue simulant candidates are modulated. Finally, given that soft tissues are biphasic in

  3. Unusual ventilation perfusion scintigram in a case of immunologic pulmonary edema clinically simulating pulmonary embolism

    SciTech Connect

    Campeau, R.J.; Faust, J.M.; Ahmad, S.

    1987-11-01

    A case of immunologic pulmonary edema secondary to hydrochlorothiazide allergy developed in a 55-year-old woman that clinically simulated pulmonary embolism. The patient had abnormal washin images with normal washout images on an Xe-133 ventilation study. On the perfusion study, large bilateral central and posterior perfusion defects were present that showed an unusual mirror image pattern on the lateral and posterior oblique views. Resolution of radiographic and scintigraphic abnormalities occurred over a 3-day period in conjunction with corticosteroid therapy.

  4. Development and Application of a Computer Simulation Program to Enhance the Clinical Problem-Solving Skills of Students.

    ERIC Educational Resources Information Center

    Boh, Larry E.; And Others

    1987-01-01

    A project to (1) develop and apply a microcomputer simulation program to enhance clinical medication problem solving in preclerkship and clerkship students and (2) perform an initial formative evaluation of the simulation is described. A systematic instructional design approach was used in applying the simulation to the disease state of rheumatoid…

  5. Simulating crop growth with Expert-N-GECROS under different site conditions in Southwest Germany

    NASA Astrophysics Data System (ADS)

    Poyda, Arne; Ingwersen, Joachim; Demyan, Scott; Gayler, Sebastian; Streck, Thilo

    2016-04-01

    When feedbacks between the land surface and the atmosphere are investigated by Atmosphere-Land surface-Crop-Models (ALCM) it is fundamental to accurately simulate crop growth dynamics as plants directly influence the energy partitioning at the plant-atmosphere interface. To study both the response and the effect of intensive agricultural crop production systems on regional climate change in Southwest Germany, the crop growth model GECROS (YIN & VAN LAAR, 2005) was calibrated based on multi-year field data from typical crop rotations in the Kraichgau and Swabian Alb regions. Additionally, the SOC (soil organic carbon) model DAISY (MÜLLER et al., 1998) was implemented in the Expert-N model tool (ENGEL & PRIESACK, 1993) and combined with GECROS. The model was calibrated based on a set of plant (BBCH, LAI, plant height, aboveground biomass, N content of biomass) and weather data for the years 2010 - 2013 and validated with the data of 2014. As GECROS adjusts the root-shoot partitioning in response to external conditions (water, nitrogen, CO2), it is suitable to simulate crop growth dynamics under changing climate conditions and potentially more frequent stress situations. As C and N pools and turnover rates in soil as well as preceding crop effects were expected to considerably influence crop growth, the model was run in a multi-year, dynamic way. Crop residues and soil mineral N (nitrate, ammonium) available for the subsequent crop were accounted for. The model simulates growth dynamics of winter wheat, winter rape, silage maize and summer barley at the Kraichgau and Swabian Alb sites well. The Expert-N-GECROS model is currently parameterized for crops with potentially increasing shares in future crop rotations. First results will be shown.

  6. Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions

    NASA Astrophysics Data System (ADS)

    Smith, David J.; Schuerger, Andrew C.; Davidson, Mark M.; Pacala, Stephen W.; Bakermans, Corien; Onstott, Tullis C.

    2009-03-01

    Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25°C for 24 h within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 h of exposure to Mars-normal conditions of 4.55 W/m2 UVC irradiation (200-280 nm), -12.5°C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H2O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at τ = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 h exposure period.

  7. Survivability of Psychrobacter cryohalolentis K5 Under Simulated Martian Surface Conditions

    NASA Technical Reports Server (NTRS)

    Smith, David J.; Schuerger, Andrew C.; Davidson, Mark M.; Pacala, Stephen W.; Bakermans, Corien; Onstott, Tullis

    2008-01-01

    Spacecraft launched to Mars can retain viable terrestrial microorganisms on board that may survive the interplanetary transit. Such biota might compromise the search for life beyond Earth if capable of propagating on Mars. The current study explored the survivability of Psychrobacter cryohalolentis K5, a psychrotolerant microorganism obtained from a Siberian permafrost cryopeg, under simulated martian surface conditions of high ultraviolet irradiation, high desiccation, low temperature, and low atmospheric pressure. First, a desiccation experiment compared the survival of P. cryohalolentis cells embedded, or not embedded, within a medium/salt matrix (MSM) maintained at 25 degrees C for 24 hr within a laminar flow hood. Results indicate that the presence of the MSM enhanced survival of the bacterial cells by 1 to 3 orders of magnitude. Second, tests were conducted in a Mars Simulation Chamber to determine the UV tolerance of the microorganism. No viable vegetative cells of P. cryohalolentis were detected after 8 hr of exposure to Mars-normal conditions of 4.55 W/m(2) UVC irradiation (200-280 nm), -12.5 degrees C, 7.1 mbar, and a Mars gas mix composed of CO2 (95.3%), N2 (2.7%), Ar (1.6%), O2 (0.2%), and H(2)O (0.03%). Third, an experiment was conducted within the Mars chamber in which total atmospheric opacities were simulated at tau = 0.1 (dust-free CO2 atmosphere at 7.1 mbar), 0.5 (normal clear sky with 0.4 = dust opacity and 0.1 = CO2-only opacity), and 3.5 (global dust storm) to determine the survivability of P. cryohalolentis to partially shielded UVC radiation. The survivability of the bacterium increased with the level of UVC attenuation, though population levels still declined several orders of magnitude compared to UVC-absent controls over an 8 hr exposure period.

  8. Molecular Dynamics Simulation and Analysis of Interfacial Water at Selected Sulfide Mineral Surfaces under Anaerobic Conditions

    SciTech Connect

    Jin, Jiaqi; Miller, Jan D.; Dang, Liem X.

    2014-04-10

    In this paper, we report on a molecular dynamics simulation (MDS) study of the behavior of interfacial water at selected sulfide mineral surfaces under anaerobic conditions. The study revealed the interfacial water structure and wetting characteristics of the pyrite (100) surface, galena (100) surface, chalcopyrite (012) surface, sphalerite (110) surface, and molybdenite surfaces (i.e., the face, armchair-edge, and zigzag-edge surfaces), including simulated contact angles, relative number density profiles, water dipole orientations, hydrogen-bonding, and residence times. For force fields of the metal and sulfur atoms in selected sulfide minerals used in the MDS, we used the universal force field (UFF) and another set of force fields optimized by quantum chemical calculations for interactions with interfacial water molecules at selected sulfide mineral surfaces. Simulation results for the structural and dynamic properties of interfacial water molecules indicate the natural hydrophobic character for the selected sulfide mineral surfaces under anaerobic conditions as well as the relatively weak hydrophobicity for the sphalerite (110) surface and two molybdenite edge surfaces. Part of the financial support for this study was provided by the U.S. Department of Energy (DOE) under Basic Science Grant No. DE-FG-03-93ER14315. The Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences (BES), of the DOE, funded work performed by Liem X. Dang. Battelle operates Pacific Northwest National Laboratory for DOE. The calculations were carried out using computer resources provided by BES. The authors are grateful to Professor Tsun-Mei Chang for valuable discussions.

  9. A cloud model simulation of space shuttle exhaust clouds in different atmospheric conditions

    NASA Technical Reports Server (NTRS)

    Chen, C.; Zak, J. A.

    1989-01-01

    A three-dimensional cloud model was used to characterize the dominant influence of the environment on the Space Shuttle exhaust cloud. The model was modified to accept the actual heat and moisture from rocket exhausts and deluge water as initial conditions. An upper-air sounding determined the ambient atmosphere in which the cloud could grow. The model was validated by comparing simulated clouds with observed clouds from four actual Shuttle launches. The model successfully produced clouds with dimensions, rise, decay, liquid water contents and vertical motion fields very similar to observed clouds whose dimensions were calculated from 16 mm film frames. Once validated, the model was used in a number of different atmospheric conditions ranging from very unstable to very stable. In moist, unstable atmospheres simulated clouds rose to about 3.5 km in the first 4 to 8 minutes then decayed. Liquid water contents ranged from 0.3 to 1.0 g kg-1 mixing ratios and vertical motions were from 2 to 10 ms-1. An inversion served both to reduce entrainment (and erosion) at the top and to prevent continued cloud rise. Even in the most unstable atmospheres, the ground cloud did not rise beyond 4 km and in stable atmospheres with strong low level inversions the cloud could be trapped below 500 m. Wind shear strongly affected the appearance of both the ground cloud and vertical column cloud. The ambient low-level atmospheric moisture governed the amount of cloud water in model clouds. Some dry atmospheres produced little or no cloud water. One case of a simulated TITAN rocket explosion is also discussed.

  10. Simulation of the environmental climate conditions on martian surface and its effect on Deinococcus radiodurans

    NASA Astrophysics Data System (ADS)

    de la Vega, U. Pogoda; Rettberg, P.; Reitz, G.

    The resistance of terrestrial microorganisms under the thermo-physical conditions of Mars (diurnal temperature variations, UV climate, atmospheric pressure and gas composition) at mid-latitudes was studied for the understanding and assessment of potential life processes on Mars. In order to accomplish a targeted search for life on other planets, e.g. Mars, it is necessary to know the limiting physical and chemical parameters of terrestrial life. Therefore the polyextremophile bacterium Deinococcus radiodurans was chosen as test organism for these investigations. For the simulation studies at the Planetary and Space Simulation Facilities (PSI) at DLR, Cologne, Germany, conditions that are present during the southern summer at latitude of 60° on Mars were applied. We could simulate several environmental parameters of Mars in one single experiment: vacuum/low pressure, anoxic atmosphere and diurnal cycles in temperature and relative humidity, energy-rich ultraviolet (UV) radiation as well as shielding by different martian soil analogue materials. These parameters have been applied both single and in different combinations in laboratory experiments. Astonishingly the diurnal Mars-like cycles in temperature and relative humidity affected the viability of D. radiodurans cells quite severely. But the martian UV climate turned out to be the most deleterious factor, though D. radiodurans is red-pigmented due to carotenoids incorporated in its cell wall, which have been assigned not only a possible role as free radical scavenger but also as a UV-protectant. An additional UV-protection was accomplished by mixing the bacteria with nano-sized hematite.

  11. Using Elearning techniques to support problem based learning within a clinical simulation laboratory.

    PubMed

    Docherty, Charles; Hoy, Derek; Topp, Helena; Trinder, Kathryn

    2004-01-01

    This paper details the results of the first phase of a project that used eLearning to support students' learning within a simulated environment. The locus was a purpose built Clinical Simulation Laboratory (CSL) where the School's newly adopted philosophy of Problem Based Learning (PBL) was challenged through lecturers reverting to traditional teaching methods. The solution, a student-centred, problem-based approach to the acquisition of clinical skills was developed using learning objects embedded within web pages that substituted for lecturers providing instruction and demonstration. This allowed lecturers to retain their facilitator role, and encouraged students to explore, analyse and make decisions within the safety of a clinical simulation. Learning was enhanced through network communications and reflection on video performances of self and others. Evaluations were positive, students demonstrating increased satisfaction with PBL, improved performance in exams, and increased self-efficacy in the performance of nursing activities. These results indicate that an elearning approach can support PBL in delivering a student centred learning experience. PMID:15360935

  12. Uncertainties in MM5 climate simulations: physics configuration vs. driving conditions

    NASA Astrophysics Data System (ADS)

    Jerez, S.; Gomez-Navarro, J. J.; Jimenez-Guerrero, P.; Lorente-Plazas, R.; Montavez, J. P.

    2010-12-01

    High resolution climate simulations are largely demanded for several applications, e.g. evaluating the climate change impacts at regional scales and the potential of the renewable energy resources. Regional Climate Models (RCMs) increase the resolution of coarser databases taking into account the local features and their influence in the physical processes ocurring at finer scales. Nevertheless, some of these processes remain still masked by the spatial resolutions considered in RCMs and must be solved through parameterizations. The mesoescale model MM5 includes several options for each parameterized process. The selection of the aforementioned options could lead to important differences. This work assesses them by analyzing two multi-physics ensembles of climate simulations over the Iberian Peninsula (IP) covering the period 1970-1999. Each ensemble consists of eight members resulting from combining two Planetary Boundary Layer (PBL) schemes, two cumulus (CML) parameterizations, and two microphysics (MIC) modeling options. The simulations have been performed twice, using both ERA40 and ECHAM5-Run1 as driving conditions. Thus, uncertainties due to the physics configuration of MM5 when reproducing the climate of the IP have been compared with uncertainties coming from the boundary conditions selected. The analysis has been carried out focusing on mean values of temperature and precipitation. Both variables are underestimated when the ECHAM5-driven ensemble mean is compared to the ERA40-driven ensemble mean. In the case of temperature, the largest underestimation is found in summer in the inner southeastern IP, reaching values over 3 K as the cold bias. The largest ensemble spread falls in the same area and season, reaches values up to 3 K, and is mainly determined by the choice of the PBL scheme. The influence of the CML and MIC schemes is much lower throughout the year. Regarding precipitation, the largest underestimation is found in winter in the north-western IP

  13. Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions

    DOE PAGES

    Nagayama, T.; Bailey, J. E.; Loisel, G.; Rochau, G. A.; MacFarlane, J. J.; Golovkin, I.

    2016-02-05

    Recently, frequency-resolved iron opacity measurements at electron temperatures of 170–200 eV and electron densities of (0.7 – 4.0) × 1022 cm–3 revealed a 30–400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproducemore » the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. Furthermore, these simulations bridge the static-uniform picture of the

  14. Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions

    NASA Astrophysics Data System (ADS)

    Nagayama, T.; Bailey, J. E.; Loisel, G.; Rochau, G. A.; MacFarlane, J. J.; Golovkin, I.

    2016-02-01

    Recently, frequency-resolved iron opacity measurements at electron temperatures of 170-200 eV and electron densities of (0.7 - 4.0 )× 1022cm-3 revealed a 30 - 400 % disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015), 10.1038/nature14048]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. These simulations bridge the static-uniform picture of the data

  15. Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions.

    PubMed

    Nagayama, T; Bailey, J E; Loisel, G; Rochau, G A; MacFarlane, J J; Golovkin, I

    2016-02-01

    Recently, frequency-resolved iron opacity measurements at electron temperatures of 170-200 eV and electron densities of (0.7-4.0)×10(22)cm(-3) revealed a 30-400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. These simulations bridge the static-uniform picture of the data interpretation and the

  16. Use of Simulation to Study Nurses Acceptance and Non-Acceptance of Clinical Decision Support Suggestions

    PubMed Central

    Sousa, Vanessa E. C.; Lopez, Karen Dunn; Febretti, Alessandro; Stifter, Janet; Yao, Yingwei; Johnson, Andrew; Wilkie, Diana J.; Keenan, Gail M.

    2015-01-01

    Our long term goal is to ensure nurse clinical decision support (CDS) works as intended before full deployment in clinical practice. As part of a broader effort, this pilot explores factors influencing acceptance/non-acceptance of 8 CDS suggestions displayed through selecting a blinking red button in an electronic health record (EHR) based nursing plan of care software prototype. A diverse sample of 21 nurses participated in this high fidelity clinical simulation experience and completed a questionnaire to assess reasons for accepting/not accepting the CDS suggestions. Of 168 total suggestions displayed during the experiment (8 for each of the 21 nurses), 123 (73.2%) were accepted and 45 (26.8%) were not accepted. The mode number of acceptances by nurses was 7 of 8 with only 2 of 21 nurses accepting all. The main reason for CDS acceptance was the nurse’s belief that the suggestions were good for the patient (n=100%) with other features being secondarily reinforcing. Reasons for non-acceptance were less clear, with under half of the subjects indicating low confidence in the evidence. This study provides preliminary evidence that high quality simulation and targeted questionnaires about specific CDS selections offers a cost effective means for testing before full deployment in clinical practice. PMID:26361268

  17. Growth and development in higher plants under simulated microgravity conditions on a 3-dimensional clinostat

    NASA Astrophysics Data System (ADS)

    Shimazu, T.; Yuda, T.; Miyamoto, K.; Yamashita, M.; Ueda, J.

    Growth and development of etiolated pea (Pisum sativum L. cv. Alaska) and maize (Zea mays L. cv. Golden Cross Bantam) seedlings grown under simulated microgravity conditions were intensively studied using a 3-dimensional clinostat as a simulator of weightlessness. Epicotyls of etiolated pea seedlings grown on the clinostat were the most oriented toward the direction far from cotyledons. Mesocotyls of etiolated maize seedlings grew at random and coleoptiles curved slightly during clinostat rotation. Clinostat rotation promoted the emergence of the 3rd internodes in etiolated pea seedlings, while it significantly inhibited the growth of the 1st internodes. In maize seedlings, the growth of coleoptiles was little affected by clinostat rotation, but that of mesocotyls was suppressed, and therefore, the emergence of the leaf out of coleoptile was promoted. Clinostat rotation reduced the osmotic concentration in the 1st internodes of pea seedlings, although it has little effect on the 2nd and the 3rd internodes. Clinostat rotation also reduced the osmotic concentrations in both coleoptiles and mesocotyls of maize seedlings. Cell-wall extensibilities of the 1st and the 3rd internodes of pea seedlings grown on the clinostat were significantly lower and higher as compared with those on 1 g conditions, respectively. Cell-wall extensibility of mesocotyls in seedlings grown on the clinostat also decreased. Changes in cell wall properties seem to be well correlated to the growth of each organ in pea and maize seedlings. These results suggest that the growth and development of plants is controlled under gravity on earth, and that the growth responses of higher plants to microgravity conditions are regulated by both cell-wall mechanical properties and osmotic properties of stem cells.

  18. Interception, retention and translocation under greenhouse conditions of radiocaesium and radiostrontium from a simulated accidental source.

    PubMed

    Vandecasteel, C M; Baker, S; Förstel, H; Muzinsky, M; Millan, R; Madoz-Escande, C; Tormos, J; Sauras, T; Schulte, E; Colle, C

    2001-10-20

    The behaviour of radioactive aerosols released from a severely damaged nuclear reactor and deposited on cereals was simulated under controlled conditions. 137Cs- and 90Sr-labelled aerosols were generated by volatilisation at high temperature of an artificially spiked pellet of depleted UO2. After cooling and maturation the aerosols were allowed to deposit on spring wheat (Triticum aestivum L. var. Arbon) cultures grown on lysimeters under greenhouse conditions. At the time of contamination the wheat plants were at different stages of development, from early vegetative growth (two leaves) until nearly mature (end of flowering). The estimated interception coefficient (micro) amounted to 13.1 m2 kg(-1); such a high value may be explained by the experimental conditions that created an over-saturated atmosphere during the contamination process and wet leaf surfaces. The first simulated rain, applied 6 days after the contamination, removed four times more 137Cs (54%+/-12 of the intercepted radionuclides) than 90Sr (15%+/-20) from the aerial parts. At harvest approximately 2% of the Sr and less than 1% of the Cs initially intercepted by the aerial parts is recovered for plants contaminated during the early development stages. A significantly higher proportion of the intercepted activity is still present for plants contaminated in the late development stages. The translocation to grains (TLF) increases when deposit occurs closer to the mature stage of the plant. The initial decrease of TLF values that we observed for strontium contamination in the earliest development stages is most probably due to the contribution of root uptake. Ploughing and re-sowing after the first rain, applied as a countermeasure reduced the 137Cs content in leaves and stems at harvest approximately 3 times but had no effect on the 90Sr content in vegetative organs. It reduced the 137Cs-contamination level in edible parts (grain) by a factor of 2 compared to the unploughed control, but doubled the

  19. Lichens as a Model-System for Symbiotic Organisms under Simulated Extreme Space Conditions

    NASA Astrophysics Data System (ADS)

    de Vera, J.; Horneck, G.; Rettberg, P.; Ott, S.

    As a consequence of the symbiotic state of lichens both the bionts are able to colonize habitats where the separate bionts would not be able to survive. The symbiosis of lichens reflects a high degree of complexity and plasticity. The combination of the different bionts enables these organisms to colonize most extreme habitats worldwide from the Arctic and Alpine zones to the Antarctic. Besides the already well investigated microorganisms lichens are good model -systems to examine adaptation strategies to most extreme environments. Because of the symbiotic nature of the lichens a 3-component -system can be used for investigations: the mycobiont (fungi), the photobiont (algae) and the lichen itself. Our investigations are based on such a system related to simulated extreme conditions. The influence of different doses of UV A, B, C (>200nm) on the vitality of fungal (mycobiont) fruiting bodys and their spores and the germination process has been investigated. The spores are cultivated on a variety of different substrates, especially on a Martian Regolith Simulant JSC - 1-A g a r- Extract for testing the influence of the UV radiation related to the dependency of different soil-substrate-extracts. The influence of vacuum conditions has been investigated. The aim of this research is to test the reaction of a symbiotic organism complex and its respective bionts to highly extreme space conditions looking forward to a possibly survival strategy of lichenized associations in space; probably supporting the theory of Panspermia. For the interpretation of results especially refering to the vitality potential of the photobionts in damaged and healthy lichens the method of modern confocal lasermicroscopy (CLSM) - a novel method in lichenology is presented.

  20. Interception, retention and translocation under greenhouse conditions of radiocaesium and radiostrontium from a simulated accidental source.

    PubMed

    Vandecasteel, C M; Baker, S; Förstel, H; Muzinsky, M; Millan, R; Madoz-Escande, C; Tormos, J; Sauras, T; Schulte, E; Colle, C

    2001-10-20

    The behaviour of radioactive aerosols released from a severely damaged nuclear reactor and deposited on cereals was simulated under controlled conditions. 137Cs- and 90Sr-labelled aerosols were generated by volatilisation at high temperature of an artificially spiked pellet of depleted UO2. After cooling and maturation the aerosols were allowed to deposit on spring wheat (Triticum aestivum L. var. Arbon) cultures grown on lysimeters under greenhouse conditions. At the time of contamination the wheat plants were at different stages of development, from early vegetative growth (two leaves) until nearly mature (end of flowering). The estimated interception coefficient (micro) amounted to 13.1 m2 kg(-1); such a high value may be explained by the experimental conditions that created an over-saturated atmosphere during the contamination process and wet leaf surfaces. The first simulated rain, applied 6 days after the contamination, removed four times more 137Cs (54%+/-12 of the intercepted radionuclides) than 90Sr (15%+/-20) from the aerial parts. At harvest approximately 2% of the Sr and less than 1% of the Cs initially intercepted by the aerial parts is recovered for plants contaminated during the early development stages. A significantly higher proportion of the intercepted activity is still present for plants contaminated in the late development stages. The translocation to grains (TLF) increases when deposit occurs closer to the mature stage of the plant. The initial decrease of TLF values that we observed for strontium contamination in the earliest development stages is most probably due to the contribution of root uptake. Ploughing and re-sowing after the first rain, applied as a countermeasure reduced the 137Cs content in leaves and stems at harvest approximately 3 times but had no effect on the 90Sr content in vegetative organs. It reduced the 137Cs-contamination level in edible parts (grain) by a factor of 2 compared to the unploughed control, but doubled the

  1. The professional medical ethics model of decision making under conditions of clinical uncertainty.

    PubMed

    McCullough, Laurence B

    2013-02-01

    The professional medical ethics model of decision making may be applied to decisions clinicians and patients make under the conditions of clinical uncertainty that exist when evidence is low or very low. This model uses the ethical concepts of medicine as a profession, the professional virtues of integrity and candor and the patient's virtue of prudence, the moral management of medical uncertainty, and trial of intervention. These features combine to justifiably constrain clinicians' and patients' autonomy with the goal of preventing nondeliberative decisions of patients and clinicians. To prevent biased recommendations by the clinician that promote such nondeliberative decisions, medically reasonable alternatives supported by low or very low evidence should be offered but not recommended. The professional medical ethics model of decision making aims to improve the quality of decisions by reducing the unacceptable variation that can result from nondeliberative decision making by patients and clinicians when evidence is low or very low.

  2. The prevalence of refractive conditions in Puerto Rican adults attending an eye clinic system

    PubMed Central

    Rodriguez, Neisha M.; Romero, Angel. F.

    2014-01-01

    Purpose To determine the prevalence of refractive conditions in the adult population that visited primary care optometry clinics in Puerto Rico. Methods A retrospective cross-sectional study of patients examined at the Inter American University of Puerto Rico School of Optometry Eye Institute Clinics between 2004 and 2010. Subjects considered had best corrected visual acuity by standardized subjective refraction of 20/40 or better. The refractive errors were classified by the spherical equivalent (SE): sphere+½ cylinder. Myopia was classified as a SE>−0.50 D, hyperopia as a SE>+0.50  D, and emmetropia as a SE between −0.50 and +0.50, both included. Astigmatism equal or higher than 0.25 D in minus cylinder form was used. Patients with documented history of cataract extraction (pseudophakia or aphakia), amblyopia, refractive surgery or other corneal/ocular surgery were excluded from the study. Results A total of 784 randomly selected subjects older than 40 years of age were selected. The estimated prevalence (95%, confidence interval) among all subjects was hyperopia 51.5% (48.0–55.0), emmetropia 33.8% (30.5–37.2), myopia 14.7% (12.1–17.2) and astigmatism 69.6% (68.8–73.3). Hyperopia was more common in females than males although the difference was not statistically significant. The mean spherical equivalent values was hyperopic until 70 y/o and decreased slightly as the population ages. Conclusion Hyperopia is the most common refractive error and its prevalence and seems to increase among the aging population who visited the clinics. Further programs and studies must be developed to address the refractive errors needs of the adult Puerto Rican population. PMID:25000872

  3. Placebo mechanisms across different conditions: from the clinical setting to physical performance

    PubMed Central

    Pollo, Antonella; Carlino, Elisa; Benedetti, Fabrizio

    2011-01-01

    Although the great increase in interest in the placebo phenomenon was spurred by the clinical implications of its use, the progressive elucidation of the neurobiological and pharmacological mechanisms underlying the placebo effect also helps cast new light on the relationship between mind (and brain) and body, a topic of foremost philosophical importance but also a major medical issue in light of the complex interactions between the brain on the one hand and body functions on the other. While the concept of placebo can be a general one, with a broad definition generally applicable to many different contexts, the description of the cerebral processes called into action in specific situations can vary widely. In this paper, examples will be given where physiological or pathological conditions are altered following the administration of an inert substance or verbal instructions tailored to induce expectation of a change, and explanations will be offered with details on neurotransmitter changes and neural pathways activated. As an instance of how placebo effects can extend beyond the clinical setting, data in the physical performance domain and implications for sport competitions will also be presented and discussed. PMID:21576136

  4. Water retention of selected microorganisms and Martian soil simulants under close to Martian environmental conditions

    NASA Astrophysics Data System (ADS)

    Jänchen, J.; Bauermeister, A.; Feyh, N.; de Vera, J.-P.; Rettberg, P.; Flemming, H.-C.; Szewzyk, U.

    2014-08-01

    Based on the latest knowledge about microorganisms resistant towards extreme conditions on Earth and results of new complex models on the development of the Martian atmosphere we quantitatively examined the water-bearing properties of selected extremophiles and simulated Martian regolith components and their interaction with water vapor under close to Martian environmental conditions. Three different species of microorganisms have been chosen and prepared for our study: Deinococcus geothermalis, Leptothrix sp. OT_B_406, and Xanthoria elegans. Further, two mineral mixtures representing the early and the late Martian surface as well as montmorillonite as a single component of phyllosilicatic minerals, typical for the Noachian period on Mars, were selected. The thermal mass loss of the minerals and bacteria-samples was measured by thermoanalysis. The hydration and dehydration properties were determined under close to Martian environmental conditions by sorption isotherm measurements using a McBain-Bakr quartz spring balance. It was possible to determine the total water content of the materials as well as the reversibly bound water fraction as function of the atmospheres humidity by means of these methods. Our results are important for the evaluation of future space mission outcomes including astrobiological aspects and can support the modeling of the atmosphere/surface interaction by showing the influence on the water inventory of the upper most layer of the Martian surface.

  5. Degradation of tocopherols during rapeseed storage in simulated conditions of industrial silos

    NASA Astrophysics Data System (ADS)

    Gawrysiak-Witulska, Marzena; Siger, Aleksander; Rusinek, Robert

    2016-01-01

    The investigations consisted in laboratory simulation of conditions prevailing in the real ecosystem in an industrial rapeseed storage facility. The aim of the study was to assess the impact of temperature, moisture, and static pressure on degradation of tocopherols contained in rapeseed. Rapeseed varieties with high oil content were analysed in the investigations. Samples of seeds with 7, 10, 13, and 16% moisture levels were stored at a temperature of 25, 30, and 35°C in specially designed airtight pressure silos for storage in controlled conditions. During the storage, the seeds were subjected to overpressure in the range of 20-60 kPa. The seeds were stored in these conditions for 28 days. It was demonstrated that primarily moisture induced the greatest loss of the total content of tocopherol and its α-T and γ-T homologues, followed by temperature and, to a lesser extent, pressure. In addition, the results obtained showed that, in the case of seeds characterised by higher moisture levels (13 and 16%), an increase in the storage temperature in the range of 25-30°C rather than 30-35°C intensified tocopherol loss more efficiently.

  6. Simulated water fluxes during the growing season in semiarid grassland ecosystems under severe drought conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Na; Liu, Chengyu

    2014-05-01

    To help improve understanding of how changes in climate and land cover affect water fluxes, water budgets, and the structure and function of regional grassland ecosystems, the Grassland Landscape Productivity Model (GLPM) was used to simulate spatiotemporal variation in primary water fluxes. The study area was a semiarid region in Inner Mongolia, China, in 2002, when severe drought was experienced. For Stipa grandis steppe, Leymus chinensis steppe, shrubland, and croplands, the modeled total, daily and monthly averaged, and maximum evapotranspiration during the growing season and the modeled water deficits were similar to those measured in Inner Mongolia under similar precipitation conditions. The modeled temporal variations in daily evaporation rate, transpiration rate, and evapotranspiration rate for the typical steppes also agreed reasonably well with measured trends. The results demonstrate that water fluxes varied in response to spatiotemporal variations in environmental factors and associated changes in the phenological and physiological characteristics of plants. It was also found that transpiration and evapotranspiration (rather than precipitation) were the primary factors controlling differences in water deficit among land cover types. The results also demonstrate that specific phenomena occur under severe drought conditions; these phenomena are considerably different to those occurring under normal or well-watered conditions. The findings of the present study will be useful for evaluating day-scale water fluxes and their relationships with climate change, hydrology, land cover, and vegetation dynamics.

  7. Plasma ionization under simulated ambient Mars conditions for quantification of methane by mass spectrometry.

    PubMed

    Taghioskoui, Mazdak; Zaghloul, Mona

    2016-04-01

    Ambient ionization techniques enable ion production in the native sample environment for mass spectrometry, without a need for sample preparation or separation. These techniques provide superior advantages over conventional ionization methods and are well developed and investigated for various analytical applications. However, employing ambient ionization techniques for in situ extra-terrestrial chemical analysis requires these techniques to be designed and developed according to the ambient conditions of extra-terrestrial environments, which substantially differ from the ambient conditions of Earth. Here, we report a plasma ionization source produced under simulated ambient Mars conditions for mass spectrometry. The plasma ionization source was coupled to a quadrupole mass spectrometer, and quantitative and qualitative analyses of trace amounts of methane, as an analyte of interest in Mars discovery missions, were demonstrated. The miniature plasma source was operational at a net power as low as ∼1.7 W in the pressure range of 4-16 Torr. A detection limit as low as ∼0.15 ppm (v/v) at 16 Torr for methane was demonstrated. PMID:26947458

  8. Plasma ionization under simulated ambient Mars conditions for quantification of methane by mass spectrometry.

    PubMed

    Taghioskoui, Mazdak; Zaghloul, Mona

    2016-04-01

    Ambient ionization techniques enable ion production in the native sample environment for mass spectrometry, without a need for sample preparation or separation. These techniques provide superior advantages over conventional ionization methods and are well developed and investigated for various analytical applications. However, employing ambient ionization techniques for in situ extra-terrestrial chemical analysis requires these techniques to be designed and developed according to the ambient conditions of extra-terrestrial environments, which substantially differ from the ambient conditions of Earth. Here, we report a plasma ionization source produced under simulated ambient Mars conditions for mass spectrometry. The plasma ionization source was coupled to a quadrupole mass spectrometer, and quantitative and qualitative analyses of trace amounts of methane, as an analyte of interest in Mars discovery missions, were demonstrated. The miniature plasma source was operational at a net power as low as ∼1.7 W in the pressure range of 4-16 Torr. A detection limit as low as ∼0.15 ppm (v/v) at 16 Torr for methane was demonstrated.

  9. Factors limiting endurance of armor, artillery, and infantry units under simulated NBC conditions

    SciTech Connect

    Rauch, T.M.; Tharion, W.J.; Banderet, L.E.; Lussier, A.R.

    1986-03-13

    The war of the future will require 72-hour operations in environments contaminated with nuclear/biological/chemical (NBC) agents. The 1985 P2NBC2 (Physiological and Psychological Effects of NBC and Extended Operations on Combined Arms Crews) Program assessed soldier endurance and performance under simulated NBC conditions. A total of 175 soldiers were observed during four tests differing in design, site, climatic conditions, and performance demands. In all but one of the iterations where the full chemical-protective ensemble (MOPP 4) was used without cooling, soldier endurance fell far short of the projected requirement. Psychological data were analyzed to determine which factors were associated with the incidence of casualties. The findings showed that perceived intensity of symptoms resembling the hyperventilation syndrome was significantly greater in soldiers classified as Casualties. Five of these symptoms (painful breathing, difficulty breathing, shortness of breath, headache, and nausea) showed Casualty-Survivor differences in all tests. Symptom intensity was attributed to two factors. (1) External conditions. Thermal stress exacerbated the five basic symptoms, induced others (tetany and paresthesia), and decreased endurance. Periodic relief from respirator use attenuated these symptoms and enhanced endurance. (2) Individual differences. Significant Casualty-Survivor differences in anxiety, depression, and cognitive strategy scores indicated that perception of hyperventilation symptoms and endurance were related to personality variables. Hyperventilation symptoms could incapacitate the soldier or induce removal of the protective mask under actual chemical attack.

  10. The role of ultrasound simulators in education: an investigation into sonography student experiences and clinical mentor perceptions.

    PubMed

    Gibbs, Vivien

    2015-11-01

    Simulation as an effective pedagogy is gaining momentum at all levels of health care education. Limited research has been undertaken on the role of simulated learning in health care and further evaluation is needed to explore the quality of learning opportunities offered, and their effectiveness in the preparation of students for clinical practice. This study was undertaken to explore ways of integrating simulation-based learning into sonography training to enhance clinical preparation. A qualitative study was undertaken, using interviews to investigate the experiences of a group of sonography students after interacting with an ultrasound simulator. The perceptions of their clinical mentors on the effectiveness of this equipment to support the education and development of sonographers were also explored. The findings confirm that ultrasound simulators provide learning opportunities in an unpressurised environment, which reduces stress for the student and potential harm to patients. Busy clinical departments acknowledge the advantages of opportunities for students to acquire basic psychomotor skills in a classroom setting, thereby avoiding the inevitable reduction in patient throughput which results from clinical training. The limitations of simulation equipment to support the development of the full range of clinical skills required by sonographers were highlighted and suggestions made for more effective integration of simulation into the teaching and learning process. Ultrasound simulators have a role in sonography education, but continued research needs to be undertaken in order to develop appropriate strategies to support students, educators and mentors to effectively integrate this methodology. PMID:27433260

  11. Simulation of Surface-Water Conditions in the Nontidal Passaic River Basin, New Jersey

    USGS Publications Warehouse

    Spitz, Frederick J.

    2007-01-01

    The Passaic River Basin, the third largest drainage basin in New Jersey, encompasses 950 mi2 (square miles) in the highly urbanized area outside New York City, with a population of 2 million. Water quality in the basin is affected by many natural and anthropogenic factors. Nutrient loading to the Wanaque Reservoir in the northern part of the basin is of particular concern and is caused partly by the diversion of water at two downstream intakes that is transferred back upstream to refill the reservoir. The larger of these diversions, Wanaque South intake, is on the lower Pompton River near Two Bridges, New Jersey. To support the development of a Total Maximum Daily Load (TMDL) for nutrients in the nontidal part of the basin (805 mi2), a water-quality transport model was needed. The U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection and New Jersey EcoComplex, developed a flow-routing model to provide the hydraulic inputs to the water-quality model. The Diffusion Analogy Flow model (DAFLOW) described herein was designed for integration with the Water Quality Analysis Simulation Program (WASP) watershed water-quality model. The flow routing model was used to simulate flow in 108 miles of the Passaic River and major tributaries. Flow data from U.S. Geological Survey streamflow-gaging stations represent most of the model's upstream boundaries. Other model inputs include estimated flows for ungaged tributaries and unchanneled drainage along the mainstem, and reported flows for major point-source discharges and diversions. The former flows were calibrated using the drainage-area ratio method. The simulation extended over a 4+ year period representing a range in flow conditions. Simulated channel cross-sectional geometry in the DAFLOW model was calibrated using several different approaches by adjusting area and top width parameters. The model also was calibrated to observed flows for water year 2001 (low flow) at five mainstem

  12. Open Knee: Open Source Modeling & Simulation to Enable Scientific Discovery and Clinical Care in Knee Biomechanics

    PubMed Central

    Erdemir, Ahmet

    2016-01-01

    Virtual representations of the knee joint can provide clinicians, scientists, and engineers the tools to explore mechanical function of the knee and its tissue structures in health and disease. Modeling and simulation approaches such as finite element analysis also provide the possibility to understand the influence of surgical procedures and implants on joint stresses and tissue deformations. A large number of knee joint models are described in the biomechanics literature. However, freely accessible, customizable, and easy-to-use models are scarce. Availability of such models can accelerate clinical translation of simulations, where labor intensive reproduction of model development steps can be avoided. The interested parties can immediately utilize readily available models for scientific discovery and for clinical care. Motivated by this gap, this study aims to describe an open source and freely available finite element representation of the tibiofemoral joint, namely Open Knee, which includes detailed anatomical representation of the joint's major tissue structures, their nonlinear mechanical properties and interactions. Three use cases illustrate customization potential of the model, its predictive capacity, and its scientific and clinical utility: prediction of joint movements during passive flexion, examining the role of meniscectomy on contact mechanics and joint movements, and understanding anterior cruciate ligament mechanics. A summary of scientific and clinically directed studies conducted by other investigators are also provided. The utilization of this open source model by groups other than its developers emphasizes the premise of model sharing as an accelerator of simulation-based medicine. Finally, the imminent need to develop next generation knee models are noted. These are anticipated to incorporate individualized anatomy and tissue properties supported by specimen-specific joint mechanics data for evaluation, all acquired in vitro from varying age

  13. Bacterial drug tolerance under clinical conditions is governed by anaerobic adaptation but not anaerobic respiration.

    PubMed

    Hemsley, Claudia M; Luo, Jamie X; Andreae, Clio A; Butler, Clive S; Soyer, Orkun S; Titball, Richard W

    2014-10-01

    Noninherited antibiotic resistance is a phenomenon whereby a subpopulation of genetically identical bacteria displays phenotypic tolerance to antibiotics. We show here that compared to Escherichia coli, the clinically relevant genus Burkholderia displays much higher levels of cells that tolerate ceftazidime. By measuring the dynamics of the formation of drug-tolerant cells under conditions that mimic in vivo infections, we show that in Burkholderia bacteria, oxygen levels affect the formation of these cells. The drug-tolerant cells are characterized by an anaerobic metabolic signature and can be eliminated by oxygenating the system or adding nitrate. The transcriptome profile suggests that these cells are not dormant persister cells and are likely to be drug tolerant as a consequence of the upregulation of anaerobic nitrate respiration, efflux pumps, β-lactamases, and stress response proteins. These findings have important implications for the treatment of chronic bacterial infections and the methodologies and conditions that are used to study drug-tolerant and persister cells in vitro.

  14. [The clinical and morphological features of pulmonary tuberculosis under the conditions of the Far North].

    PubMed

    Vinokurov, I I; Argunov, V A; Nikolaev, Iu Ia; Plotnikova, N V

    2006-01-01

    The clinical and morphological features of pulmonary tuberculomas were studied in 205 patients among the naives and newcomers of the Far North. It was established that the lymphohematogenous spread of tuberculosis involving mainly the lymphatic system into the inflammatory process predominates in the genesis of tuberculomas under the conditions of the Far North. At the same time the lymphatic genesis of tuberculosis was found to affect the development of pulmonary tuberculomas in 60% of cases among the native patients. In most patients, the afflicted intrathoracic lymph nodes became a source of retrograde dissemination of tuberculosis in the lung. Tuberculomas were chiefly unilateral and in 56.7% of cases they were located in the lower portions of the lung in the presence of significant fibrosis. The lymphohematogenous spread of tuberculous infection was a cause of pulmonary tuberculomas in most (72.9%) newcomers on adapting to the conditions of the Far North. In most cases, tuberculomas were formed from a newly appeared tuberculous focus in the presence of intact lung tissue and located in the upper portions of both lungs. The formed tuberculomas had no extensive focal dissemination and were present within the anatomic structure of one or two segments of the lung.

  15. Properties of the flexible pressure sensor under laboratory conditions simulating the internal environment of the total surface bearing socket.

    PubMed

    Hachisuka, K; Takahashi, M; Ogata, H; Ohmine, S; Shitama, H; Shinkoda, K

    1998-12-01

    The purpose of this study was to investigate the properties of the flexible pressure sensor under laboratory conditions simulating the internal environment of the total surface bearing (TSB) socket to determine optimal conditions for measuring normal stresses on the stump. The equipment used in the study was the Pressure Distribution Sensor System for Sockets. In a climatic chamber maintained at 37 degrees C and 70% humidity the sensor sheet was mounted on a measuring apparatus loaded with three 10 kg weights, and output from the sensor was recorded. Because of sensor creep, a sample 60 seconds after loading was adopted as the measured output. Output was greater when weight was decreased than when weight was increased because of hysteresis (paired t-test, p<0.05). The sensor had temperature sensitivity but differences in output were not statistically significant (paired t-test, 0.10>p>0.05). There were no significant differences in output among five sensor sheets or among five sections of four sensor sheets (two-way ANOVA, p>0.05), but repeated loading on the same section of the sensor sheet increased output (two-way ANOVA, p<0.05). Reproducibility and sensitivity distribution of the sensor are considered satisfactory under laboratory conditions, but measurements of rapid and repetitive movements may not be accurate and comparing subtle changes in output from a single sensor is not suitable. The reliability of the sensor in a clinical setting for measuring normal stresses on the stump with the TSB socket should be examined.

  16. Developing an Evaluation Tool for Assessing Clinical Ethics Consultation Skills in Simulation Based Education: The ACES Project.

    PubMed

    Wasson, Katherine; Parsi, Kayhan; McCarthy, Michael; Siddall, Viva Jo; Kuczewski, Mark

    2016-06-01

    The American Society for Bioethics and Humanities has created a quality attestation (QA) process for clinical ethics consultants; the pilot phase of reviewing portfolios has begun. One aspect of the QA process which is particularly challenging is assessing the interpersonal skills of individual clinical ethics consultants. We propose that using case simulation to evaluate clinical ethics consultants is an approach that can meet this need provided clear standards for assessment are identified. To this end, we developed the Assessing Clinical Ethics Skills (ACES) tool, which identifies and specifies specific behaviors that a clinical ethics consultant should demonstrate in an ethics case simulation. The aim is for the clinical ethics consultant or student to use a videotaped case simulation, along with the ACES tool scored by a trained rater, to demonstrate their competence as part of their QA portfolio. The development and piloting of the tool is described. PMID:25794891

  17. Developing an Evaluation Tool for Assessing Clinical Ethics Consultation Skills in Simulation Based Education: The ACES Project.

    PubMed

    Wasson, Katherine; Parsi, Kayhan; McCarthy, Michael; Siddall, Viva Jo; Kuczewski, Mark

    2016-06-01

    The American Society for Bioethics and Humanities has created a quality attestation (QA) process for clinical ethics consultants; the pilot phase of reviewing portfolios has begun. One aspect of the QA process which is particularly challenging is assessing the interpersonal skills of individual clinical ethics consultants. We propose that using case simulation to evaluate clinical ethics consultants is an approach that can meet this need provided clear standards for assessment are identified. To this end, we developed the Assessing Clinical Ethics Skills (ACES) tool, which identifies and specifies specific behaviors that a clinical ethics consultant should demonstrate in an ethics case simulation. The aim is for the clinical ethics consultant or student to use a videotaped case simulation, along with the ACES tool scored by a trained rater, to demonstrate their competence as part of their QA portfolio. The development and piloting of the tool is described.

  18. Testing of Icy-Soil Sample Delivery in Simulated Martian Conditions (Animation)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This movie clip shows testing under simulated Mars conditions on Earth in preparation for NASA's Phoenix Mars Lander using its robotic arm for delivering a sample to the doors of a laboratory oven.

    The icy soil used in the testing flowed easily from the scoop during all tests at Martian temperatures. On Mars, icy soil has stuck to the scoop, a surprise that may be related to composition of the soil at the landing site.

    This testing was done at Honeybee Robotics Spacecraft Mechanisms Corp., New York, which supplied the Phoenix scoop.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASAaE(TM)s Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Multi-dimensional PIC-simulations of parametric instabilities for shock-ignition conditions

    NASA Astrophysics Data System (ADS)

    Riconda, C.; Weber, S.; Klimo, O.; Héron, A.; Tikhonchuk, V. T.

    2013-11-01

    Laser-plasma interaction is investigated for conditions relevant for the shock-ignition (SI) scheme of inertial confinement fusion using two-dimensional particle-in-cell (PIC) simulations of an intense laser beam propagating in a hot, large-scale, non-uniform plasma. The temporal evolution and interdependence of Raman- (SRS), and Brillouin- (SBS), side/backscattering as well as Two-Plasmon-Decay (TPD) are studied. TPD is developing in concomitance with SRS creating a broad spectrum of plasma waves near the quarter-critical density. They are rapidly saturated due to plasma cavitation within a few picoseconds. The hot electron spectrum created by SRS and TPD is relatively soft, limited to energies below one hundred keV.

  20. Structure and density of basaltic melts at mantle conditions from first-principles simulations

    PubMed Central

    Bajgain, Suraj; Ghosh, Dipta B.; Karki, Bijaya B.

    2015-01-01

    The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our results suggest that as pressure increases, all types of coordination between major cations and anions strongly increase, and the water speciation changes from isolated species to extended forms. These structural changes are responsible for rapid initial melt densification on compression thereby making these basaltic melts possibly buoyantly stable at one or more depths. Our finding that the melt-water system is ideal (nearly zero volume of mixing) and miscible (negative enthalpy of mixing) over most of the mantle conditions strengthens the idea of potential water enrichment of deep-mantle melts and early magma ocean. PMID:26450568

  1. [EEG-correlates of pilots' functional condition in simulated flight dynamics].

    PubMed

    Kiroy, V N; Aslanyan, E V; Bakhtin, O M; Minyaeva, N R; Lazurenko, D M

    2015-01-01

    The spectral characteristics of the EEG recorded on two professional pilots in the simulator TU-154 aircraft in flight dynamics, including takeoff, landing and horizontal flight (in particular during difficult conditions) were analyzed. EEG recording was made with frequency band 0.1-70 Hz continuously from 15 electrodes. The EEG recordings were evaluated using analysis of variance and discriminant analysis. Statistical significant of the identified differences and the influence of the main factors and their interactions were evaluated using Greenhouse - Gaiser corrections. It was shown that the spectral characteristics of the EEG are highly informative features of the state of the pilots, reflecting the different flight phases. High validity ofthe differences including individual characteristic, indicates their non-random nature and the possibility of constructing a system of pilots' state control during all phases of flight, based on EEG features.

  2. Structure and density of basaltic melts at mantle conditions from first-principles simulations.

    PubMed

    Bajgain, Suraj; Ghosh, Dipta B; Karki, Bijaya B

    2015-01-01

    The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our results suggest that as pressure increases, all types of coordination between major cations and anions strongly increase, and the water speciation changes from isolated species to extended forms. These structural changes are responsible for rapid initial melt densification on compression thereby making these basaltic melts possibly buoyantly stable at one or more depths. Our finding that the melt-water system is ideal (nearly zero volume of mixing) and miscible (negative enthalpy of mixing) over most of the mantle conditions strengthens the idea of potential water enrichment of deep-mantle melts and early magma ocean. PMID:26450568

  3. Structure and density of basaltic melts at mantle conditions from first-principles simulations

    NASA Astrophysics Data System (ADS)

    Bajgain, Suraj; Ghosh, Dipta B.; Karki, Bijaya B.

    2015-10-01

    The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our results suggest that as pressure increases, all types of coordination between major cations and anions strongly increase, and the water speciation changes from isolated species to extended forms. These structural changes are responsible for rapid initial melt densification on compression thereby making these basaltic melts possibly buoyantly stable at one or more depths. Our finding that the melt-water system is ideal (nearly zero volume of mixing) and miscible (negative enthalpy of mixing) over most of the mantle conditions strengthens the idea of potential water enrichment of deep-mantle melts and early magma ocean.

  4. Fate of plasticised PVC products under landfill conditions: a laboratory-scale landfill simulation reactor study.

    PubMed

    Mersiowsky, I; Weller, M; Ejlertsson, J

    2001-09-01

    The long-term behaviour of plasticised PVC products was investigated in laboratory-scale landfill simulation reactors. The examined products included a cable material and a flooring with different combinations of plasticisers. The objective of the study was to assess whether a degradation of the PVC polymer or a loss of plasticisers occurred under landfill conditions. A degradation of the polymer matrix was not observed. The contents of plasticisers in aged samples was determined and compared to the respective original products. The behaviour of the various plasticisers was found to differ significantly. Losses of DEHP and BBP from the flooring were too low for analytical quantification. No loss of DIDP from the cable was detectable, whereas DINA in the same product showed considerable losses of up to 70% compared to the original contents. These deficits were attributable to biodegradation rather than leaching. There was no equivalent release of plasticisers into the leachate. PMID:11487101

  5. Experimental simulations of oxidizing conditions and organic decomposition on the surface of Mars

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Mancinelli, Rocco L.; Mckay, Christopher P.

    1988-01-01

    One important scientific objective of a Mars Rover Sample Return mission would be to look for traces of living and extinct life on Mars. An instrument to search for organic carbon may be the simplest instrument that could screen samples which are interesting from a biological point of view. An experimental program is described which would help to understand the nature of the oxidizing soil on Mars and the mechanism responsible for organic degradation on the Martian surface. This is approached by lab simulations of the actual conditions that occur on Mars, particularly the oxidant production by atmospheric photochemistry, and the combined effects of UV light and oxidants in decomposing organic compounds. The results will be used to formulate models of the photochemistry of the atmospheric, the atmosphere-soil interaction, and the diffusion of reactive compounds into the soils. This information will provide insights and constraints on the design of a sampling strategy to search for organic compounds on Mars.

  6. Growth and Survival of Some Probiotic Strains in Simulated Ice Cream Conditions

    NASA Astrophysics Data System (ADS)

    Homayouni, A.; Ehsani, M. R.; Azizi, A.; Razavi, S. H.; Yarmand, M. S.

    A Completely Randomized Design (CRD) experiment was applied in triplicates to evaluate the survival of four probiotic strains in simulated ice cream conditions. The growth and survival rate of these probiotic strains (Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium longum) in varying amount of sucrose (10, 15, 20 and 25%), oxygen scavenging components (0.05% L-cysteine and 0.05% L-ascorbate) and temperatures (4 and -20°C) during different periods of time (1, 2 and 3 months) were evaluated in MRS-broth medium. Optical density at 580 nm was used to measure growth. Lactobacilli strains proved to be highly resistant in comparison with Biffidobacteria strains. The viable cell number of Lactobacillus casei in different sucrose concentrations, different oxidoreduction potentials and refrigeration temperature was 1x1010, 2x108 and 5x107 cfu mL-1, respectively. Growth and survival rate of Lactobacillus casei showed to be the highest.

  7. On the multiplication of xerophilic micro-organisms under simulated Martian conditions.

    PubMed

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

    1973-01-01

    The environmental conditions prevailing on Mars would supposedly favour the existence there of micro-organisms belonging to xerophiles, anaerobes, or micro-aerophiles, oligonitrophiles, which are able to grow in wide temperature intervals. From soil samples taken in deserts and tundra, antarctic halophilic bacteria, able to grow in liquid media containing 20-25% of sodium chloride, were isolated. Some of these cultures appeared to be also osmophilic (growth on media with 50% glucose); they grew at temperatures from 5 degrees C to 50 degrees C, and developed on media without a nitrogen source (oligonitrophiles). Of special interest was the halophilic and osmophilic form of Bacillus megaterium isolated from the Nubian desert. In experiments with this bacterium the following technique was used. A thin film of potato extract agar was prepared on a glass slide and dried over a saturated K2SO4 solution in a closed container up to the level of maximal hygroscopic moisture. The cell suspension was then sprayed on to the agar surface, the film dried again at 45 degrees C, and the glass slide put in the test tube over the saturated solution of K2SO4. The test tube was evacuated, flushed three times with a gas mixture containing 80% CO2 plus 20% Ar, and sealed. Under these conditions the water content of the agar film was equal to the maximal hygroscopic moisture; only the xerophilic form of bacteria are able to develop at this moisture level. This halophilic strain of Bac. megaterium grew satisfactorily under these conditions, as did a halophilic and osmophilic strain of Mycococcus ruber isolated in Antarctica. Both the halophilic strain of Bac. megaterium and that of M. ruber were able to grow under simulated Martian conditions. Xerophily and halophily may be linked. This assumption was supported by relatively high incidence of xerophilic forms among halophilic bacteria isolated from different soils of both high and low salt content as well as from salty muds.

  8. Simulations of a Liquid Hydrogen Inducer at Low-Flow Off-Design Flow Conditions

    NASA Technical Reports Server (NTRS)

    Hosangadi, A.; Ahuja, V.; Ungewitter, R. J.

    2005-01-01

    The ability to accurately model details of inlet back flow for inducers operating a t low-flow, off-design conditions is evaluated. A sub-scale version of a three-bladed liquid hydrogen inducer tested in water with detailed velocity and pressure measurements is used as a numerical test bed. Under low-flow, off-design conditions the length of the separation zone as well as the swirl velocity magnitude was under predicted with a standard k-E model. When the turbulent viscosity coefficient was reduced good comparison was obtained a t all the flow conditions examined with both the magnitude and shape of the profile matching well with the experimental data taken half a diameter upstream of the leading edge. The velocity profiles and incidence angles a t the leading edge itself were less sensitive to the back flow length predictions indicating that single-phase performance predictions may be well predicted even if the details of flow separation modeled are incorrect. However, for cavitating flow situations the prediction of the correct swirl in the back flow and the pressure depression in the core becomes critical since it leads to vapor formation. The simulations have been performed using the CRUNCH CFD(Registered Trademark) code that has a generalized multi-element unstructured framework and a n advanced multi-phase formulation for cryogenic fluids. The framework has been validated rigorously for predictions of temperature and pressure depression in cryogenic fluid cavities and has also been shown to predict the cavitation breakdown point for inducers a t design conditions.

  9. Diagenetic compaction of simulated anhydrite fault gouge under static conditions and implications for fault healing behaviour

    NASA Astrophysics Data System (ADS)

    Pluymakers, A.; Peach, C. J.; Spiers, C. J.

    2013-12-01

    For geological storage of CO2 in depleted oil and gas reservoirs to be effective, the stored gas must remain isolated from the atmosphere for thousands of years. Faults that cut the reservoir/seal system are considered one of the most likely leakage pathways, especially if fault reactivation leads to fault dilation. However, when fault movement ceases, newly formed fault gouge will heal as a function of time. To estimate the time scale on which such healing occurs, an understanding of the deformation mechanisms that control fault (gouge) compaction is needed. Anhydrite is a common caprock in many oil and gas fields around the world and in the Netherlands in particular, where anhydrite-capped reservoirs present several options for CO2 storage. For this reason, we performed uniaxial compaction experiments on simulated anhydrite fault gouge to investigate the deformation and healing processes that operate under simulated post-slip conditions, i.e. static conditions. The gouge was prepared by crushing and sieving nearly pure anhydrite (>95wt%) derived from exploration boreholes in the north of the Netherlands. Constant stress (5-12 MPa) and stress stepping experiments (5/7.5/10 MPa) were conducted at 80°C on fault gouge samples of different initial grain size (20-500μm), under both wet and dry conditions. We also performed preliminary experiments to determine the effect of CO2 on the healing behaviour of anhydrite gouge. Dry samples showed little or no compaction creep, whereas wet samples (i.e. samples flooded with saturated CaSO4 solution) showed compaction at easily measureable rates. In the case of wet samples, our mechanical data and microstructural observations showed that, for fine grain sizes and low stresses, the rate of gouge compaction is controlled by pressure solution under diffusion-control. With increasing grain size and stress, however, fluid-assisted subcritical microcracking becomes the dominant deformation mechanism. Pressurizing the pore fluid

  10. Simulations of potential future conditions in the cache critical groundwater area, Arkansas

    USGS Publications Warehouse

    Rashid, Haveen M.; Clark, Brian R.; Mahdi, Hanan H.; Rifai, Hanadi S.; Al-Shukri, Haydar J.

    2015-01-01

    A three-dimensional finite-difference model for part of the Mississippi River Valley alluvial aquifer in the Cache Critical Groundwater Area of eastern Arkansas was constructed to simulate potential future conditions of groundwater flow. The objectives of this study were to test different pilot point distributions to find reasonable estimates of aquifer properties for the alluvial aquifer, to simulate flux from rivers, and to demonstrate how changes in pumping rates for different scenarios affect areas of long-term water-level declines over time. The model was calibrated using the parameter estimation code. Additional calibration was achieved using pilot points with regularization and singular value decomposition. Pilot point parameter values were estimated at a number of discrete locations in the study area to obtain reasonable estimates of aquifer properties. Nine pumping scenarios for the years 2011 to 2020 were tested and compared to the simulated water-level heads from 2010. Hydraulic conductivity values from pilot point calibration ranged between 42 and 173 m/d. Specific yield values ranged between 0.19 and 0.337. Recharge rates ranged between 0.00009 and 0.0006 m/d. The model was calibrated using 2,322 hydraulic head measurements for the years 2000 to 2010 from 150 observation wells located in the study area. For all scenarios, the volume of water depleted ranged between 5.7 and 23.3 percent, except in Scenario 2 (minimum pumping rates), in which the volume increased by 2.5 percent.

  11. Simulating the hydrodynamic conditions in the United States Pharmacopeia paddle dissolution apparatus.

    PubMed

    McCarthy, Leonard G; Kosiol, Carolin; Healy, Anne Marie; Bradley, Geoff; Sexton, James C; Corrigan, Owen I

    2003-01-01

    The objective of this work was to examine the feasibility of developing a high-performance computing software system to simulate the United States Pharmacopeia (USP) dissolution apparatus 2 (paddle apparatus) and thus aid in characterizing the fluid hydrodynamics in the method. The USP apparatus was modeled using the hydrodynamic package Fluent. The Gambit program was used to create a "wireframe" of the apparatus and generate the 3-dimensional grids for the computational fluid dynamics solver. The Fluent solver was run on an IBM RS/6000 SP distributed memory parallel processor system, using 8 processors. Configurations with and without a tablet present were developed and examined. Simulations for a liquid-filled vessel at a paddle speed of 50 rpm were generated. Large variations in fluid velocity magnitudes with position in the vessel were evident. Fluid velocity predictions were in good agreement with those previously published, using laser Doppler velocity measurements. A low-velocity domain was evident directly below the center of the rotating paddle. The model was extended to simulate the impact of the presence of a cylindrical tablet in the base of the dissolution vessel. The presence of the tablet complicated the local fluid flow, and large fluid shear rates were evident at the base of the compact. Fluid shear rates varied depending on the tablet surface and the location on the surface and were consistent with the reported asymmetrical dissolution of model tablets. The approach has the potential to explain the variable dissolution results reported and to aid in the design/prediction of optimal dissolution conditions for in vitro--in vivo correlations.

  12. Space-time conditional disaggregation of precipitation at high resolution via simulation

    NASA Astrophysics Data System (ADS)

    Bárdossy, András.; Pegram, Geoffrey G. S.

    2016-02-01

    Daily rainfall data are more plentiful and reliable than pluviometer data and are the best data set to start data-repair from, worldwide. Clusters of pluviometers (a term used herein for instruments recording at subdaily intervals) record wet and dry periods in close synchrony and larger and smaller catches tend to be recorded in similar groups, but they have many gaps that require infilling. We present a method of disaggregating daily rainfall to subdaily intervals, contemporaneously infilling gaps in the pluviometers. Then the observed data, together with the infilled and disaggregated values, are interpolated over the intervening space. To achieve this disaggregation, we used a Gaussian copula-based model with time-dependent marginal distributions and censored values representing the dry periods. In addition, we generated stochastically meaningful ensembles of missing or disaggregated values, while constraining each realization to the observed daily total where relevant. This applies to the gaps filled in the pluviometers as well as the disaggregation of the daily totals. Using the disaggregated and infilled subdaily ensembles, we then conditionally spatially simulated historical rainfall in the space between the gauges and pluviometers. The mean of these stochastic realizations was compared to interpolated fields using two other procedures: Rescaled Ordinary Kriging and Rescaled Nearest Neighbors, and found our method to be superior. Where there are daily data, the daily sum constrains the simulation. In the intervening space, in a chosen daily subinterval, there will be an ensemble of values simulated from the observations. We present the results of measurements and validation of the applications to an unusually large amount of data (not just a few convenient samples), and are confident that the methodology is sound and applicable in a variety of geographies.

  13. Grid-size dependence of Cauchy boundary conditions used to simulate stream-aquifer interactions

    USGS Publications Warehouse

    Mehl, S.; Hill, M.C.

    2010-01-01

    This work examines the simulation of stream–aquifer interactions as grids are refined vertically and horizontally and suggests that traditional methods for calculating conductance can produce inappropriate values when the grid size is changed. Instead, different grid resolutions require different estimated values. Grid refinement strategies considered include global refinement of the entire model and local refinement of part of the stream. Three methods of calculating the conductance of the Cauchy boundary conditions are investigated. Single- and multi-layer models with narrow and wide streams produced stream leakages that differ by as much as 122% as the grid is refined. Similar results occur for globally and locally refined grids, but the latter required as little as one-quarter the computer execution time and memory and thus are useful for addressing some scale issues of stream–aquifer interactions. Results suggest that existing grid-size criteria for simulating stream–aquifer interactions are useful for one-layer models, but inadequate for three-dimensional models. The grid dependence of the conductance terms suggests that values for refined models using, for example, finite difference or finite-element methods, cannot be determined from previous coarse-grid models or field measurements. Our examples demonstrate the need for a method of obtaining conductances that can be translated to different grid resolutions and provide definitive test cases for investigating alternative conductance formulations.

  14. Simulation of groundwater conditions and streamflow depletion to evaluate water availability in a Freeport, Maine, watershed

    USGS Publications Warehouse

    Nielsen, Martha G.; Locke, Daniel B.

    2012-01-01

    , the public-supply withdrawals (105.5 million gallons per year (Mgal/yr)) were much greater than those for any other category, being almost 7 times greater than all domestic well withdrawals (15.3 Mgal/yr). Industrial withdrawals in the study area (2.0 Mgal/yr) are mostly by a company that withdraws from an aquifer at the edge of the Merrill Brook watershed. Commercial withdrawals are very small (1.0 Mgal/yr), and no irrigation or other agricultural withdrawals were identified in this study area. A three-dimensional, steady-state groundwater-flow model was developed to evaluate stream-aquifer interactions and streamflow depletion from pumping, to help refine the conceptual model, and to predict changes in streamflow resulting from changes in pumping and recharge. Groundwater levels and flow in the Freeport aquifer study area were simulated with the three-dimensional, finite-difference groundwater-flow modeling code, MODFLOW-2005. Study area hydrology was simulated with a 3-layer model, under steady-state conditions. The groundwater model was used to evaluate changes that could occur in the water budgets of three parts of the local hydrologic system (the Harvey Brook watershed, the Merrill Brook watershed, and the buried aquifer from which pumping occurs) under several different climatic and pumping scenarios. The scenarios were (1) no pumping well withdrawals; (2) current (2009) pumping, but simulated drought conditions (20-percent reduction in recharge); (3) current (2009) recharge, but a 50-percent increase in pumping well withdrawals for public supply; and (4) drought conditions and increased pumping combined. In simulated drought situations, the overall recharge to the buried valley is about 15 percent less and the total amount of streamflow in the model area is reduced by about 19 percent. Without pumping, infiltration to the buried valley aquifer around the confining unit decreased by a small amount (0.05 million gallons per day (Mgal/d)), and discharge to the

  15. Survival, prophage induction, and invasive properties of lysogenic Salmonella Typhimurium exposed to simulated gastrointestinal conditions.

    PubMed

    Kim, Songrae; Ryu, Kanghee; Biswas, Debabrata; Ahn, Juhee

    2014-09-01

    This study was designed to evaluate the viability, prophage induction, invasive ability, and relative gene expression in lysogenic Salmonella Typhimurium exposed to the simulated gastric juice (SGJ) at pH 2 (SGJ-2), 3 (SGJ-3), 4 (SGJ-4), and 5 (SGJ-5) for 30 min followed by 0.5 % bile salts for 2 h. The susceptibility of lysogenic S. Typhimurium increased with decreasing pH value and increasing bile salt concentration. The lysogenic S. Typhimurium cells were least susceptible to SGJ-4 and SGJ-5, showing <1 log reduction. The highest prophage induction was observed by 3.34 log PFU/ml in lysogenic S. Typhimurium at SGJ-3 in the presence of 0.5 % bile salts. The numbers of invading lysogenic S. Typhimurium treated at SGJ-3, SGJ-4, and SGJ-5 were 3.57, 3.73, and 4.15 log CFU/cm(2), respectively. Most genes (hilA, hilC, hilD, invA, invE, invF, and sirA) were down-regulated in lysogenic S. Typhimurium treated at SGJ-3, SGJ-4, and SGJ-5. This study provides useful information for understanding physiological changes of lysogenic S. Typhimurium in the simulated gastrointestinal conditions. PMID:24929817

  16. The expression of heat shock proteins 70 and 90 in pea seedlings under simulated microgravity conditions

    NASA Astrophysics Data System (ADS)

    Kozeko, L.

    Microgravity is an abnormal and so stress factor for plants. Expression of known stress-related genes is appeared to implicate in the cell response to different kinds of stress. Heat shock proteins HSP70 and HSP90 are present in plant cells under the normal growth conditions and their quantity increases during stress. The effect of simulated microgravity on expression of HSP70 and HSP90 was studied in etiolated Pisum sativum seedlings grown on the horizontal clinostat (2 rpm) from seed germination for 3 days. Seedlings were also subjected to two other types of stressors: vertical clinorotatoin (2 rpm) and 2 h temperature elevation (40°C). HSPs' level was measured by ELISA. The quantity of both HSPs increased more than in three times in the seedlings on the horizontal clinostat in comparison with the stationary 1 g control. Vertical clinorotation also increased HSPs' level but less at about 20% than horizontal one. These effects were comparable with the influence of temperature elevation. The data presented suggest that simulated microgravity upregulate HSP70 and HSP90 expression. The increased HSPs' level might evidence the important functional role of these proteins in plant adaptation to microgravity. We are currently investigating the contribution of constitutive or inducible forms of the HSPs in this stress response.

  17. A DLM/FD/IB method for simulating compound vesicle motion under creeping flow condition

    NASA Astrophysics Data System (ADS)

    Pan, Tsorng-Whay; Zhao, Shihai; Niu, Xiting; Glowinski, Roland

    2015-11-01

    In this article we present first a new distributed Lagrange multiplier/fictitious domain (DLM/FD) method for simulating fluid-particle interaction in Stokes flow. A conjugate gradient method driven by both pressure and distributed Lagrange multiplier, called one-shot method, has been developed to solve the discrete Stokes problem while enforcing the rigid body motion within the region occupied by the particle. The methodology is validated by comparing the numerical results of a neutrally buoyant particle of either a circular or elliptic shape with the associated Jeffery's solutions. We have successively combined the above methodology with an immersed boundary (IB) method and an elastic membrane modeled by a spring network to simulate the dynamics of a compound vesicle. In simple shear flow under creeping flow condition, the results are consistent with those obtained in literature. In Poiseuille flow, the compound vesicle motion is dominated by the motion of the vesicle membrane as expected and stays in the central region of the channel.

  18. Molecular Dynamics Simulations of Small Clusters and Liquid Hydrogen Sulfide at Different Thermodynamic Conditions.

    PubMed

    Albertí, M; Amat, A; Aguilar, A; Pirani, F

    2016-07-14

    A new force field for the intermolecular H2S-H2S interaction has been used to study the most relevant properties of the hydrogen sulfide system from gaseous to liquid phases by means of molecular dynamics (MD) simulations. In order to check the validity of the interaction formulation, ab initio CCSD(T)/aug-cc-pVTZ calculations, including the counterpoise correction on the H2S, (H2S)2, and (H2S)3 structures optimized at the MP2/aug-cc-pVDZ level, have been performed. The (H2S)2,3 systems have been characterized by performing NVE MD simulations at decreasing values of the temperature, while the liquid sulfide behavior has been investigated considering a NpT ensemble of 512 molecules at several thermodynamic states, defined by different pressure and temperature values. Additional calculations using an ensemble of 2197 molecules at two different temperatures have been performed to investigate the liquid/vapor interface of the system. The S-S, S-H, and H-H radial distribution functions and the coordination number, calculated at the same conditions used in X-ray and neutron diffraction experiments, and the evaluated thermodynamic and structural properties have been compared successfully with experimental data, thus confirming the reliability of the force field formulation and of the MD predictions.

  19. Laboratory Evaluation and Application of Microwave Absorption Properties under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    2005-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth- based or spacecraft-based radio astronomical (emission) observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or the use of laboratory measurements of such properties taken under environmental conditions that are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, new laboratory measurements completed recently by Mohammed and Steffes (2003 and 2004) under this grant (NAG5-12122,5/1/02-4/30/05), have shown that the millimeter-wavelength opacities from both gaseous phosphine (PH3) and gaseous ammonia ("3) under simulated conditions for the outer planets vary significantly from that predicted by theory over a wide range of temperatures and pressures. These results have directly impacted planning and scientific goals for study of Saturn's atmosphere with the Cassini Radio Science Experiment, as discussed below. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both spacecraft entry probe and orbiter (or flyby) radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the

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

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1992-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements performed by Fahd and Steffes have shown that the opacity from gaseous SO2 under simulated Venus conditions can be well described by the Van Vleck-Weisskopf lineshape at wavelengths shortward of 2 cm, but that the opacity of wavelengths greater than 2 cm is best described by a different lineshape that was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  1. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1998-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties taken under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements completed recently by Kolodner and Steffes (ICARUS 132, pp. 151-169, March 1998, attached as Appendix A) under this grant (NAGS-4190), have shown that the opacity from gaseous H2SO4 under simulated Venus conditions is best described by a different formalism than was previously used. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both spacecraft entry probe and orbiter radio occultation experiments and by radio astronomical observations, and over a range of frequencies which correspond to those used in such experiments, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  2. Laboratory Evaluation and Application of Microwave Absorption Properties under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    2002-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based or spacecraft-based radio astronomical (emission) observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or the use of laboratory measurements of such properties taken under environmental conditions that are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements have shown that the centimeter-wavelength opacity from gaseous phosphine (PH3) under simulated conditions for the outer planets far exceeds that predicted from theory over a wide range of temperatures and pressures. This fundamentally changed the resulting interpretation of Voyager radio occultation data at Saturn and Neptune. It also directly impacts planning and scientific goals for study of Saturn's atmosphere with the Cassini Radio Science Experiment and the Rossini RADAR instrument. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both spacecraft entry probe and orbiter (or flyby) radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations

  3. Patient-specific simulations of stenting procedures in coronary bifurcations: two clinical cases.

    PubMed

    Morlacchi, Stefano; Colleoni, Sebastian George; Cárdenes, Rubén; Chiastra, Claudio; Diez, Jose Luis; Larrabide, Ignacio; Migliavacca, Francesco

    2013-09-01

    Computational simulations of stenting procedures in idealized geometries can only provide general guidelines and their use in the patient-specific planning of percutaneous treatments is inadequate. Conversely, image-based patient-specific tools that are able to realistically simulate different interventional options might facilitate clinical decision-making and provide useful insights on the treatment for each individual patient. The aim of this work is the implementation of a patient-specific model that uses image-based reconstructions of coronary bifurcations and is able to replicate real stenting procedures following clinical indications. Two clinical cases are investigated focusing the attention on the open problems of coronary bifurcations and their main treatment, the provisional side branch approach. Image-based reconstructions are created combining the information from conventional coronary angiography and computed tomography angiography while structural finite element models are implemented to replicate the real procedure performed in the patients. First, numerical results show the biomechanical influence of stents deployment in the coronary bifurcations during and after the procedures. In particular, the straightening of the arterial wall and the influence of two overlapping stents on stress fields are investigated here. Results show that a sensible decrease of the vessel tortuosity occurs after stent implantation and that overlapping devices result in an increased stress state of both the artery and the stents. Lastly, the comparison between numerical and image-based post-stenting configurations proved the reliability of such models while replicating stent deployment in coronary arteries.

  4. Analysis of simulated future climate conditions of Central Europe using different weather pattern classifications

    NASA Astrophysics Data System (ADS)

    Bartholy, Judit; Pongracz, Rita; Philipp, Andreas; Beck, Christoph; Kern, Aniko

    2010-05-01

    The main goals of the research are (i) to compare weather pattern classification methods for Central Europe (COST733 domain 07 covering 43-58°N, 3-26°E) using observed and simulated present climate (1961-1990), and (ii) to analyze the climate change effects on weather patterns for the same region using different classification methods. The observed climate is represented by the ECMWF ERA40 datasets, and the simulation experiments were accomplished for future climate conditions (2071-2100) using two emission scenarios (A2 and B2) in the frame of the EU-project PRUDENCE (Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects). High resolution (50 km × 50 km) simulated daily values of meteorological variables (mean sea level pressure, temperature, precipitation) have been obtained from the regional climate model (RCM) outputs of the Danish Meteorological Institute (DMI). DMI used the HIRHAM4 RCM (developed jointly by DMI and the Max-Planck Institute in Hamburg), for which the boundary conditions were provided by the HadAM3H/HadCM3 global climate model of the UK Met Office. For the weather pattern classification we use the COST733 classification software (version 0.19-17). The 12 available classification methods (grouped into (i) optimization algorithms, (ii) leader algorithms, (iii) PCA based methods, and (iv) threshold based methods) are applied to the ERA40 daily mean sea level pressure database for 1961-1990 using 9, 18, and 27 weather pattern types. The resulting circulation pattern types from 1961-1990 classifications of the mean sea level pressure fields are applied to the classification of the 2071-2100 period for both A2 and B2 scenarios. Frequency distribution changes of circulation pattern types are analyzed in the selected domain by 2071-2100 period for both A2 and B2 scenarios relative to the 1961-1990 reference period. Furthermore, temperature anomaly and precipitation pattern changes are evaluated in

  5. Application of different weather pattern classifications to simulated future climate conditions for Central Europe

    NASA Astrophysics Data System (ADS)

    Bartholy, J.; Pongracz, R.; Philipp, A.; Beck, C.; Kern, A.

    2010-09-01

    The main goals of the research are (i) to compare weather pattern classification methods for Central Europe (COST733 domain 07 covering 43-58°N, 3-26°E) using observed and simulated present climate (1961-1990), and (ii) to analyze the climate change effects on weather patterns for the same region using different classification methods. The observed climate is represented by the ECMWF ERA40 datasets, and the simulation experiments were accomplished for future climate conditions (2071-2100) using two emission scenarios (A2 and B2) in the frame of the EU-project PRUDENCE (Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects). High resolution (50 km × 50 km) simulated daily values of meteorological variables (mean sea level pressure, temperature, precipitation) have been obtained from the regional climate model (RCM) outputs of the Danish Meteorological Institute (DMI). DMI used the HIRHAM4 RCM (developed jointly by DMI and the Max-Planck Institute in Hamburg), for which the boundary conditions were provided by the HadAM3H/HadCM3 global climate model of the UK Met Office. For the weather pattern classification we use the COST733 classification software (version 0.19-17). The 12 available classification methods (grouped into (i) optimization algorithms, (ii) leader algorithms, (iii) PCA based methods, and (iv) threshold based methods) are applied to the ERA40 daily mean sea level pressure database for 1961-1990 using 9, 18, and 27 weather pattern types. The resulting circulation pattern types from 1961-1990 classifications of the mean sea level pressure fields are applied to the classification of the 2071-2100 period for both A2 and B2 scenarios. Frequency distribution changes of circulation pattern types are analyzed in the selected domain by 2071-2100 period for both A2 and B2 scenarios relative to the 1961-1990 reference period. Furthermore, temperature anomaly and precipitation pattern changes are evaluated in

  6. Influence of mineralogy on the preservation of amino acids under simulated Mars conditions

    NASA Astrophysics Data System (ADS)

    dos Santos, Renato; Patel, Manish; Cuadros, Javier; Martins, Zita

    2016-10-01

    The detection of organic molecules associated with life on Mars is one of the main goals of future life-searching missions such as the ESA-Roscosmos ExoMars and NASA 2020 mission. In this work we studied the preservation of 25 amino acids that were spiked onto the Mars-relevant minerals augite, enstatite, goethite, gypsum, hematite, jarosite, labradorite, montmorillonite, nontronite, olivine and saponite, and on basaltic lava under simulated Mars conditions. Simulations were performed using the Open University Mars Chamber, which mimicked the main aspects of the martian environment, such as temperature, UV radiation and atmospheric pressure. Quantification and enantiomeric separation of the amino acids were performed using gas-chromatography-mass spectrometry (GC-MS). Results show that no amino acids could be detected on the mineral samples spiked with 1 μM amino acid solution (0.1 μmol of amino acid per gram of mineral) subjected to simulation, possibly due to complete degradation of the amino acids and/or low extractability of the amino acids from the minerals. For higher amino acid concentrations, nontronite had the highest preservation rate in the experiments in which 50 μM spiking solution was used (5 μmol/g), while jarosite and gypsum had a higher preservation rate in the experiments in which 25 and 10 μM spiking solutions were used (2.5 and 1 μmol/g), respectively. Overall, the 3 smectite minerals (montmorillonite, saponite, nontronite) and the two sulfates (gypsum, jarosite) preserved the highest amino acid proportions. Our data suggest that clay minerals preserve amino acids due to their high surface areas and small pore sizes, whereas sulfates protect amino acids likely due to their opacity to UV radiation or by partial dissolution and crystallization and trapping of the amino acids. Minerals containing ferrous iron (such as augite, enstatite and basaltic lava) preserved the lowest amount of amino acids, which is explained by iron (II) catalyzed

  7. Stochastic Simulation of Precipitation Fields Conditioned on Radar and Gauge Information

    NASA Astrophysics Data System (ADS)

    Pfaff, T.; Bárdossy, A.

    2009-04-01

    Precipitation is the main input variable for hydrological modelling. Operational precipitation data are usually provided by rain gauges, weather radar and sometimes satellite observations., Precipitation data with very high spatial and temporal resolution is necessary especially for flash flood forecasting in small catchments. Usually these can neither be provided by rain gauge networks nor satellite measurements. However, radar data has not been used widely in operational flood forecasting yet. Modelling results obtained with radar derived precipitation forcing still don't show a better skill than those obtained by using gauge observations. Radar data suffers from a set of errors. The common ones are uncertainties in the Z-R relation, attenuation effects and uncertain vertical profiles of reflectivity. Corrections for any of these errors have been devised but it has also been shown that some corrections just shift the uncertainty from one source to another. Since the 'true' rainfall field cannot be known, true error statistics cannot be calculated. A measure of uncertainty can be obtained by comparing radar (R) and gauge data (G). Recent developments towards radar ensemble generation focus on the generation of relative uncertainty fields. They are based on comparisons of radar data with gauge data or of radar fields with reference fields obtained by gauge adjustment. The generated fields are then multiplied with the radar field to create the realizations. The proposed approach aims at stochastic simulation of precipitation fields conditioned on radar data In addition, the approach incorporates the additional information available from gauge measurements similarly to radar gauge adjustment. If radar data is adjusted by gauge data using either a multiplicative or an additive correction term, this single correction term can produce unrealistic results when it is regionalized to the radar cells surrounding the reference gauge. This problem can be avoided by splitting

  8. Improving bottom-boundary conditions for SVAT simulations in shallow-groundwater systems

    NASA Astrophysics Data System (ADS)

    Morris, Paul J.; Verhoef, Anne; Macdonald, David M. J.; Gardner, Cate M.; Punalekar, Suvarna M.; Tatarenko, Irina; Gowing, David

    2013-04-01

    A well documented disparity exists between models that simulate: i) groundwater hydrological processes; and ii) soil-vegetation-atmosphere transfers (SVAT) of water and energy. This is particularly pertinent in shallow groundwater systems, such as lowland floodplains, where the domains of surface water and groundwater necessarily overlap. Consideration of either SVAT or groundwater processes in shallow groundwater systems necessitates a robust understanding of their bi-directional interactions. The hydrological bottom-boundary conditions of SVAT models can be driven using continuous groundwater data from dipwells. However, where such data are not available the bottom boundary must be simulated. We sought to develop a simple empirical model of subsurface fluxes of water between a floodplain soil column and its adjoining river, without the additional cost and complication of a fully linked surface water-groundwater model. We conducted our research at Yarnton Mead, a floodplain meadow on the River Thames in Oxfordshire, UK. We used in-situ soil-physical, hydrological and meteorological data to generate an empirical relationship between floodplain water-table position, and rate and direction of subsurface water fluxes between the floodplain soil and the river. We estimated rates of subsurface water flux into and out of our instrumented soil column as the residual term of a water balance equation. We then fitted a linear model to describe the rate and direction of subsurface flux as a function of water-table position. Although the level of explanation of the linear model is not high (r-squared = 0.39), the relationship is highly significant (p < 0.001). When water tables are close to the ground surface the soil column loses water rapidly to the groundwater store and ultimately to the river and other local drainage features. When water tables are low the soil column receives water. This negative feedback leads to a water-table attractor, which our model suggests is

  9. Simulation of ionomer membrane fatigue under mechanical and hygrothermal loading conditions

    NASA Astrophysics Data System (ADS)

    Khorasany, Ramin M. H.; Kjeang, Erik; Wang, G. G.; Rajapakse, R. K. N. D.

    2015-04-01

    Understanding the fatigue lifetime of common perfluorosulfonic acid (PFSA) ionomer membranes under fluctuating hygrothermal conditions is essential for the development of durable fuel cell technologies. For this purpose, a finite element based fatigue lifetime prediction model is developed based on an elastic-plastic constitutive model combined with a Smith-Watson-Topper (SWT) fatigue formulation. The model is validated against previously reported experimental results for a membrane under cyclic mechanical loadings. The validated model is then utilized to investigate the membrane fatigue lifetime in ex-situ applications under cyclic humidity and temperature conditions. The simulations suggest that the membrane fatigue lifetime is shorter under fluctuating humidity loadings than for temperature loadings. Additionally, the membrane fatigue lifetime is found to be more sensitive to the amplitude of the strain oscillations than to the mean strain under hygrothermal cycling. Most notably, the model predicts that simultaneous humidity and temperature cycling can exacerbate the fatigue process and reduce the fatigue lifetime by several orders of magnitude compared to isolated humidity or temperature cycling. The combination of measured mechanical fatigue data and the present numerical model provides a useful toolkit for analysis of membrane fatigue due to hygrothermal variations, which can be costly and time-consuming when addressed experimentally.

  10. Molecular sieve generation of aviator's oxygen: Performance of a prototype system under simulated flight conditions.

    PubMed

    Miller, R L; Ikels, K G; Lamb, M J; Boscola, E J; Ferguson, R H

    1980-07-01

    The molecular sieve method of generating an enriched-oxygen breathing gas is one of several candidate onboard oxygen generation (OBOG) systems under joint Army-Navy-Air Force development for application in tactical aircraft. The performance of a nominal two-man-capacity molecular sieve oxygen generation system was characterized under simulated flight conditions. Data are given on the composition of the molecular sieve-generated breathing gas (oxygen, nitrogen, carbon dioxide, and argon) as a function of inlet air pressure, altitude, breathing gas flow rate, and ambient temperature. The maximum oxygen concentration observed was 95%, with the balance argon. At low demand flow rates and certain conditions of pressure and altitude, the argon enrichment factor exceeded that of oxygen giving a maximum argon concentration of 6.6% with the balance oxygen. The structural integrity of the unit was verified by vibration and centrifuge testing. The performance of the molecular sieve unit is discussed in the context of aircraft operating envelopes using both diluter-demand and 100% delivery subsystems. PMID:6774707

  11. Auxin polar transport in arabidopsis under simulated microgravity conditions - relevance to growth and development

    NASA Astrophysics Data System (ADS)

    Miyamoto, K.; Oka, M.; Yamamoto, R.; Masuda, Y.; Hoson, T.; Kamisaka, S.; Ueda, J.

    1999-01-01

    Activity of auxin polar transport in inflorescence axes of Arabidopsis thaliana grown under simulated microgravity conditions was studied in relation to the growth and development. Seeds were germinated and allowed to grow on an agar medium in test tubes on a horizontal clinostat. Horizontal clinostat rotation substantially reduced the growth of inflorescence axes and the productivity of seeds of Arabidopsis thaliana (ecotypes Landsberg erecta and Columbia), although it little affected seed germination, development of rosette leaves and flowering. The activity of auxin polar transport in inflorescence axes decreased when Arabidopsis plants were grown on a horizontal clinostat from germination stage, being ca. 60% of 1 g control. On the other hand, the auxin polar transport in inflorescence axes of Arabidopsis grown in 1 g conditions was not affected when the segments were exposed to various gravistimuli, including 3-dimensional clinorotation, during transport experiments. Pin-formed mutant of Arabidopsis, having a unique structure of the inflorescence axis with no flower and extremely low levels of the activity of auxin polar transport in inflorescence axes and endogenous auxin, did not continue its vegetative growth under clinostat rotation. These facts suggest that the development of the system of auxin polar transport in Arabidopsis is affected by microgravity, resulting in the inhibition of growth and development, especially during reproductive growth.

  12. Compressional and Shear Wave Velocities for Artificial Granular Media Under Simulated Near Surface Conditions

    SciTech Connect

    Bonner, B.P.; Berge, P.A.; Wildenschild, D.

    2001-09-09

    Laboratory ultrasonic experiments were made on artificial soil samples in order to observe the effects of slight overburden, sand/clay ratio and pore fluid saturation on compressional and shear wave velocities. Up to several meters of overburden were simulated by applying low uniaxial stress of about 0.1 MPa to a restrained sample. Samples were fabricated from Ottawa sand mixed with a swelling clay (Wyoming bentonite). The amount of clay added was 1 to 40 percent by mass. Most measurements were made under room-dry conditions, but some measurements were made for fully-saturated sand-clay mixtures and for partially-saturated sand samples. For the dry sand-clay samples, compressional (P) velocities were low, ranging from about 200 to 500 m/s for the mixtures at low stress. Shear (S) velocities were about half of the compressional velocity, about 70 to 250 m/s. Dramatic increases in all velocities occurred with small uniaxial loads, indicating strong nonlinearity. Composition and grain packing control the mechanical response at grain contacts and the resulting nonlinear response at low stresses. P and S velocities are sensitive to the amount of clay added, even at low concentrations. At these low equivalent overburden conditions, adhesion and capillarity at grain contacts affect wave amplitudes, velocities, and frequency content in the partial saturation case.

  13. Numerical simulation of adiabatons in electromagnetically induced transparency under quasi-resonance conditions

    SciTech Connect

    Parshkov, O M; Govorenko, E R

    2014-02-28

    The evolution of adiabatons in electromagnetically induced transparency in the Λ scheme of degenerate quantum transitions J = 0 → J = 1 → J = 2 with Doppler broadening of spectral lines has been numerically simulated taking into account the effect of resonance detunings. It is shown that, in the case of linearly polarised fields, an increase in the probe-field resonance detuning (under exact-resonance conditions for the control radiation) leads to a transformation of electromagnetically induced transparency into electromagnetically induced absorption at certain stages. When the control-field resonance detuning is varied, the transparency of the medium for the probe (exactly resonant) radiation monotonically decreases with increasing detuning because of the rising role of single-photon absorption. In the case of circularly polarised control radiation and linearly polarised input probe field, a probe pulse propagating in the medium splits into two pulses with oppositely directed circular polarisations. An increase in the probe pulse resonance detuning (under exact-resonance conditions for the control radiation) leads primarily to an increase in the absorption by the medium of the probe pulse, the direction of circular polarisation for which coincides with the circular-polarisation direction for the control radiation. (nonlinear optical phenomena)

  14. Digital image database processing to simulate image formation in ideal lighting conditions of the human eye

    NASA Astrophysics Data System (ADS)

    Castañeda-Santos, Jessica; Santiago-Alvarado, Agustin; Cruz-Félix, Angel S.; Hernández-Méndez, Arturo

    2015-09-01

    The pupil size of the human eye has a large effect in the image quality due to inherent aberrations. Several studies have been performed to calculate its size relative to the luminance as well as considering other factors, i.e., age, size of the adapting field and mono and binocular vision. Moreover, ideal lighting conditions are known, but software suited to our specific requirements, low cost and low computational consumption, in order to simulate radiation adaptation and image formation in the retina with ideal lighting conditions has not yet been developed. In this work, a database is created consisting of 70 photographs corresponding to the same scene with a fixed target at different times of the day. By using this database, characteristics of the photographs are obtained by measuring the luminance average initial threshold value of each photograph by means of an image histogram. Also, we present the implementation of a digital filter for both, image processing on the threshold values of our database and generating output images with the threshold values reported for the human eye in ideal cases. Some potential applications for this kind of filters may be used in artificial vision systems.

  15. Changes in the Salmonella status of broiler chickens subjected to simulated shipping conditions.

    PubMed Central

    Rigby, C E; Pettit, J R

    1980-01-01

    Market-age broiler chickens from flocks infected with Salmonella typhimurium were killed after being placed in crates and subjected to simulated shipping conditions for five, 19 or 24 hours. The cloacal feces, ceca and exteriors of the birds were cultured for salmonellae to identify shedders, cecal carriers and external carriers respectively, and the results compared with those obtained from pen-mates killed at the time the tested birds were put into the crates. Carriage of S. typhimurium was significantly higher among birds placed in clean crates than among the uncrated controls, mainly due to an increase in cecal carriers (from 23.5% to 61.5%). This increase was not related to the time spent in the crate. Twenty-four chickens were placed in crates contaminated with Salmonella alachua and all 24 became carriers of this organism: 22 (91.5%) of these were cecal carriers and 18 (75%) were shedders. This contamination also spread to 15/24 chickens placed in clean crates and "shipped" in the same truck: six of these became cecal carriers and seven were shedders. These results indicated that chickens in shipping crates which are exposed to salmonellae under transport conditions may readily become infected and begin to shed salmonellae within 24 hours. PMID:7004609

  16. Resistance of Antarctic black fungi and cryptoendolithic communities to simulated space and Martian conditions.

    PubMed

    Onofri, S; Barreca, D; Selbmann, L; Isola, D; Rabbow, E; Horneck, G; de Vera, J P P; Hatton, J; Zucconi, L

    2008-01-01

    Dried colonies of the Antarctic rock-inhabiting meristematic fungi Cryomyces antarcticus CCFEE 515, CCFEE 534 and C. minteri CCFEE 5187, as well as fragments of rocks colonized by the Antarctic cryptoendolithic community, were exposed to a set of ground-based experiment verification tests (EVTs) at the German Aerospace Center (DLR, Köln, Germany). These were carried out to test the tolerance of these organisms in view of their possible exposure to space conditions outside of the International Space Station (ISS). Tests included single or combined simulated space and Martian conditions. Responses were analysed both by cultural and microscopic methods. Thereby, colony formation capacities were measured and the cellular viability was assessed using live/dead dyes FUN 1 and SYTOX Green. The results clearly suggest a general good resistance of all the samples investigated. C. minteri CCFEE 5187, C. antarcticus CCFEE 515 and colonized rocks were selected as suitable candidates to withstand space flight and long-term permanence in space on the ISS in the framework of the LIchens and Fungi Experiments (LIFE programme, European Space Agency).

  17. Resistance of Antarctic black fungi and cryptoendolithic communities to simulated space and Martian conditions

    PubMed Central

    Onofri, S.; Barreca, D.; Selbmann, L.; Isola, D.; Rabbow, E.; Horneck, G.; de Vera, J.P.P.; Hatton, J.; Zucconi, L.

    2008-01-01

    Dried colonies of the Antarctic rock-inhabiting meristematic fungi Cryomyces antarcticus CCFEE 515, CCFEE 534 and C. minteri CCFEE 5187, as well as fragments of rocks colonized by the Antarctic cryptoendolithic community, were exposed to a set of ground-based experiment verification tests (EVTs) at the German Aerospace Center (DLR, Köln, Germany). These were carried out to test the tolerance of these organisms in view of their possible exposure to space conditions outside of the International Space Station (ISS). Tests included single or combined simulated space and Martian conditions. Responses were analysed both by cultural and microscopic methods. Thereby, colony formation capacities were measured and the cellular viability was assessed using live/dead dyes FUN 1 and SYTOX Green. The results clearly suggest a general good resistance of all the samples investigated. C. minteri CCFEE 5187, C. antarcticus CCFEE 515 and colonized rocks were selected as suitable candidates to withstand space flight and long-term permanence in space on the ISS in the framework of the LIchens and Fungi Experiments (LIFE programme, European Space Agency). PMID:19287532

  18. Necessary and sufficient optimality conditions for classical simulations of quantum communication processes

    NASA Astrophysics Data System (ADS)

    Montina, Alberto; Wolf, Stefan

    2014-07-01

    We consider the process consisting of preparation, transmission through a quantum channel, and subsequent measurement of quantum states. The communication complexity of the channel is the minimal amount of classical communication required for classically simulating it. Recently, we reduced the computation of this quantity to a convex minimization problem with linear constraints. Every solution of the constraints provides an upper bound on the communication complexity. In this paper, we derive the dual maximization problem of the original one. The feasible points of the dual constraints, which are inequalities, give lower bounds on the communication complexity, as illustrated with an example. The optimal values of the two problems turn out to be equal (zero duality gap). By this property, we provide necessary and sufficient conditions for optimality in terms of a set of equalities and inequalities. We use these conditions and two reasonable but unproven hypotheses to derive the lower bound n ×2n -1 for a noiseless quantum channel with capacity equal to n qubits. This lower bound can have interesting consequences in the context of the recent debate on the reality of the quantum state.

  19. Predicting the solubility of gases in Nitrile Butadiene Rubber in extreme conditions using molecular simulation

    NASA Astrophysics Data System (ADS)

    Khawaja, Musab; Molinari, Nicola; Sutton, Adrian; Mostofi, Arash

    In the oil and gas industry, elastomer seals play an important role in protecting sensitive monitoring equipment from contamination by gases - a problem that is exacerbated by the high pressures and temperatures found down-hole. The ability to predict and prevent such permeative failure has proved elusive to-date. Nitrile butadiene rubber (NBR) is a common choice of elastomer for seals due to its resistance to heat and fuels. In the conditions found in the well it readily absorbs small molecular weight gases. How this behaviour changes quantitatively for different gases as a function of temperature and pressure is not well-understood. In this work a series of fully atomistic simulations are performed to understand the effect of extreme conditions on gas solubility in NBR. Widom particle insertion is used to compute solubilities. The importance of sampling and allowing structural relaxation upon compression are highlighted, and qualitatively reasonable trends reproduced. Finally, while at STP it has previously been shown that the solubility of CO2 is higher than that of He in NBR, we observe that under the right circumstances it is possible to reverse this trend.

  20. Operational implications of a cloud model simulation of space shuttle exhaust clouds in different atmospheric conditions

    NASA Technical Reports Server (NTRS)