bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fear of blood draw and total draw time combine to predict vasovagal reactions among whole blood donors
Authors: France Christopher R. , France Janis L. , Frame‐Brown Terri A. , Venable Geri A. , Menitove Jay E. 
Published: August 2015

BACKGROUNDFear of blood draws is a predictor of vasovagal reaction risk among whole blood donors, and this relationship is particularly evident among less experienced donors. This study examines the combined effect of donor fear and total blood draw time on vasovagal reactions.STUDY DESIGN AND METHODSAfter successfully completing the blood donor health screening, 2730 whole blood donors attending high school drives were asked about their fear of having blood drawn. Donor reports of fear versus no fear were combined with total blood draw time to predict phlebotomist ratings of donor vasovagal reactions.RESULTSBoth fear and draw time were significant predictors of vasovagal reactions, with observed reaction rates of 31.2% for fearful donors whose blood draw lasted 10 minutes or more versus 5.0% for nonfearful donors whose draw lasted less than 6 minutes. Binomial regression analyses revealed that fear remained a significant predictor of reaction rates across all blood draw intervals examined (odds ratio, 2.8‐4.1; all p < 0.001) and that these effects were maintained after controlling for donor sex, weight, estimated blood volume, pulse rate, and donation status.CONCLUSIONThis report shows that both fear and blood draw time increase vasovagal reaction rates, and the two are additive. These findings suggest that fearful donors should be the focus of special attention to reduce their distress before donation as well as careful observation throughout the draw.
IS QUANTUM INDETERMINISM REAL? THEOLOGICAL IMPLICATIONS
Authors: Vanney Claudia E. 
Published: August 2015

AbstractQuantum mechanics (QM) studies physical phenomena on a microscopic scale. These phenomena are far beyond the reach of our observation, and the connection between QM's mathematical formalism and the experimental results is very indirect. Furthermore, quantum indeterminism defies common sense. Microphysical experiments have shown that, according to the empirical context, electrons and quanta of light behave as waves and other times as particles, even though it is impossible to design an experiment that manifests both behaviors at the same time. Unlike Newtonian physics, the properties of quantum systems (position, velocity, energy, time, etc.) are not all well‐defined simultaneously. Moreover, quantum systems are not characterized by their properties, but by a wave function. Although one of the principles of the theory is the uncertainty principle, the trajectory of the wave function is controlled by the deterministic Schrödinger equations. But what is the wave function? Like other theories of the physical sciences, quantum theory assigns states to systems. The wave function is a particular mathematical representation of the quantum state of a physical system, which contains information about the possible states of the system and the respective probabilities of each state.
THE SIGNIFICANCE OF EVITABILITY IN NATURE
Authors: Keogh Gary 
Published: August 2015

AbstractAssessing the current situation of the religion–science dialogue, it seems that a consensus of nonconsensus has been reached. This nonconsensus provides a pluralistic context for the religion and science dialogue, and one area where this plurality is clear is the discourse on relational models of God and creation. A number of interesting models have gained attention in contemporary theological dialogue with science, yet there is an overriding theme: an emphasis on God's involvement with the world. In this article, I argue that theology has been preoccupied with this emphasis. It is suggested that the theme of the freedom of nature has been underrepresented. This theme of the freedom of nature I argue carries important theological implications. It is suggested that acts or events gain their significance largely by way of being contextualized by the fact that such acts or events could have been otherwise, a realization that might provide the various relational models of God and the world food for thought.
LANGUAGE AS A VALUES‐REALIZING ACTIVITY: CARING, ACTING, AND PERCEIVING
Authors: Hodges Bert H. 
Published: August 2015

AbstractA problem for natural scientific accounts, psychology in particular, is the existence of value. An ecological account of values is reviewed and illustrated in three domains of research: carrying differing loads; negotiating social dilemmas involving agreement and disagreement; and timing the exposure of various visual presentations. Then it is applied in greater depth to the nature of language. As described and illustrated, values are ontological relationships that are neither subjective nor objective, but which constrain and obligate all significant animate activity physically, socially, and morally. As an embodied social activity, conversational dialogue is characterized in terms of values, pragmatics, and presence rather than in terms of syntactic and semantic rules. In particular the nature of dialogical arrays is explored, and the hypothesis that language is an action system, a perceptual system, and a caring system is explored. Language expands horizons and makes it possible for humans to realize their calling as culture makers and caretakers.
Control of Separations in a Highly-Loaded Axial Compressor Cascade by Tailored Boundary Layer Suction
Authors: Mao Xiaochen , Liu Bo , Zhang Guochen 
Published: August 2015

In order to study the effectiveness and mechanisms of boundary layer suction (BLS) in controlling both the boundary layer separation on the whole span of suction surface (SS) and the three-dimensional (3D) separation in the corner, a 3D linear compressor cascade was investigated by tailored BLS. First, experimental investigations at a range of incidences from −10° to 10° were undertaken on both the original cascade and the aspirated cascade (SS1) in a high-subsonic cascade wind tunnel. The results show that the profile loss coefficient of the aspirated cascade is reduced remarkably as the suction flow ratio increases at the incidences from −5° to 8°. Based on the experimental investigations, numerical simulations were employed to study the flow fields of the original and aspirated cascade in detail. It was found that part blade span suction on the aspirated cascade can effectively remove the separation at the suction span where suction slot exists, resulting that the flow fields of other spans deteriorated.
Due to the interaction of separations both on the SS and the end-wall, the 3D separation in the corner are more complicated, so another three tailored BLS schemes were designed totally in order to fully remove both the boundary-layer separation on SS and the 3D separation. It was found that the span-wise distribution of static pressure was changed after suction and it could influence the transport of the low-energy fluid between the end-wall and the mid-span. The separation over the whole span of SS and the 3D separation in the corner were fully eliminated by combined suction scheme (CS). Finally, the incidence characteristics of the 3D linear cascade under the control of CS scheme were investigated numerically together with the suction flow rate matching problem of the different suction slots.
An Annular Pulsed Detonation Combustor Mockup: System Identification and Misfiring Detection
Authors: Wolff Sascha , King Rudibert 
Published: August 2015

An annular pulsed detonation combustor basically consists of a number of detonation tubes which are firing in a predetermined sequence into a common downstream annular plenum. Fluctuating initial conditions and fluctuating environmental parameters strongly affect the detonation. Operating such a set-up without misfiring is delicate. Misfiring of individual combustion tubes will significantly lower performance or even stop the engine. Hence, an operation of such an engine requires a misfiring detection.
Here, a model-based approach is used which exploits the innovation sequence calculated by a Kalman filter. The model necessary for the Kalman filter is determined based on a modal identification technique. A surrogate, nonreacting experimental set-up is considered in order to develop and test these methods.
Development of a Predictive Method for Quantifying Vortex-Shedding Pulsation Amplitudes in Compressor Piping Systems
Authors: Simons Sarah , Broerman Eugene L. , Brun Klaus 
Published: August 2015

One of the design criteria for centrifugal compressor piping systems is the prevention of piping and valve failures from high pulsation amplitudes and vibration caused by vortex-shedding induced (VSI) pulsations of gas flow past closed piping branches (stubs). Most vortex-shedding analyses are performed on the basis of frequency avoidance. If a coincidence is predicted between the acoustic natural frequency of a piping segment and the flow induced vortex shedding frequency, piping changes must be made to avoid the coincidence, since there is currently no known method for accurately predicting the severity of the resulting pulsation amplitudes and, therefore, the possibility of piping failures. Often, these piping changes are expensive and time consuming and likely unnecessary for smaller bore piping (10-inch or less), assuming the flow-acoustic coincidence does not coincide with a mechanical resonance.
The majority of research performed to date on vortex-shedding excitation of piping stubs focuses on predicting the frequencies of excitation using an experimentally determined Strouhal number or range of numbers for a given geometry or piping feature. However, to properly design a piping system using a combination of support structures and piping changes, reliable prediction of the pulsation amplitude is essential for determining the shaking forces acting on the piping system and the resulting vibration and stress amplitudes. Due to the expense of experimental testing and availability of equipment, it is difficult to obtain accurate amplitude measurements of VSI pulsations of fluids at Reynolds numbers typically associated with natural gas transmission.
This paper describes a series of experimental tests performed to record vortex-shedding induced pulsation amplitudes in three test facilities. Three different process fluids were utilized varying the operating conditions to obtain gas flows with Reynold’s numbers between 1e5 and 2e7. Steady state flow, temperature and pressure data was recorded with ASME PTC-10 compliant instrumentation. Transient pressure data was taken with dynamic pressure transducers installed at each stub end as well as in the main piping near the tee. The geometry configurations, pulsation amplitudes, and calculated Strouhal numbers associated with each test configuration are presented. Comparison was made between the test results and several previously published formulas. From the test results, a predictive method was developed to best represent the limit of the pulsation amplitudes.
Effects of Blade Deformation on the Performance of a High Flow Coefficient Mixed Flow Impeller
Authors: Hazby Hamid , Woods Ian , Casey Michael , Numakura Ryusuke , Tamaki Hideaki 
Published: August 2015

The effects of blade deformation under running conditions on the performance of a highly loaded transonic mixed flow impeller were investigated. Two impellers were manufactured, one using the “running” blade profiles as designed and one using the converted “unrunning” or “cold” geometry. Both impellers were tested experimentally and investigated numerically.
The test data taken with smooth casing showed that at maximum speed, the isentropic efficiency and pressure ratio of the running geometry was higher than the unrunning geometry by about 0.4% and 1.4%, respectively. However, the difference in performance diminished in the presence of recirculating casing treatment. Numerical calculations suggested that the differences at high speeds were mainly due to the variation in the impeller tip clearance. The calculations using deformed blade profiles under centrifugal load only, predicted performance differences which were about twice as high as the measured values. However, closer predictions were obtained when the effects of pressure loads on blade deformation were included using closely coupled fluid-structural analyses.
A Combined Analytical and Numerical Approach to Analyze Mud Motor Excited Vibrations in Drilling Systems
Authors: Hohl Andreas , Hohl Carsten , Herbig Christian 
Published: August 2015

Severe vibrations in drillstrings and bottomhole assemblies can be caused by cutting forces at the bit or mass imbalances in downhole tools. One of the largest imbalances is related to the working principle of the so-called mud motor, which is an assembly of a rotor that is maintained by the stator. One of the design-related problems is how to minimize vibrations excited by the mud motor.
Simulation tools using specialized finite element methods (FEM) are established to model the mechanical behavior of the structure. Although finite element models are useful for estimating rotor dynamic behavior and dynamic stresses of entire drilling systems they do not give direct insight how parameters affect amplitudes and stresses. Analytical models show the direct influence of parameters and give qualitative solutions of design related decisions. However these models do not provide quantitative numbers for complicated geometries.
An analytical beam model of the mud motor is derived to calculate the vibrational amplitudes and capture basic dynamic effects. The model shows the direct influence of parameters of the mud motor related to the geometry, material properties and fluid properties. The analytical model is compared to the corresponding finite element model. Vibrational amplitudes are discussed for different modes and parameter changes. Finite element models of the entire drilling system are used to verify the findings from the analytical model using practical applications. The results are compared to time domain and statistical data from laboratory and field measurements.
The Quantification of Impact of Geometrical and Operational Parameters Uncertainty on the Numerical Simulation Results of Axial Turbine Working Process
Authors: Kolmakova Daria , Popov Grigorii , Baturin Oleg , Krivcov Alexander 
Published: August 2015

The quantification of geometric and physical variables uncertainty impact on turbomachinery row workflow was conducted using several untwisted airfoil cascades of axial turbine nozzle blades with uniform section throughout the channel height.
Profile loss coefficient, mass flow parameter, outlet flow angle were accepted as controlled performance criteria.
The series of computational calculations were carried out for these cascades. The first group of calculations was aimed at the identification of the impact of geometric parameters uncertainty on nozzle blades parameters. The second group of calculations was conducted for identifying the studied parameters depending on the flow parameters changes that are used as boundary conditions in the simulation.
The obtained results showed that initial data uncertainty in CFD calculations has a significant impact on the obtained quantitative estimates. The difference between calculated data modified in accordance with the geometry technological tolerances and workflow parameters measurement error may exceed 5% by value of the considered criteria.
A Three-Regime Based Method for Correlating Film Cooling Effectiveness for Cylindrical and Shaped Holes
Authors: Wang Lieke , Kinell Mats , Najafabadi Hossein N. , Karlsson Matts 
Published: August 2015

To cope with high temperature of the gas from combustor, cooling is often used in the hot gas components in gas turbines. Film cooling is one of the effective methods used in this application. Both cylindrical and fan-shaped holes are used in film cooling. There have been a number of correlations published for both cylindrical and fan-shaped holes regarding film cooling effectiveness. Unfortunately there are no definitive correlations for either cylindrical or fan-shaped holes. This is due to the nature of the complexity of film cooling where many factors influence its performance, e.g., blowing ratio, density ratio, surface angle, downstream distance, expansion angle, hole length, turbulence level, etc.
A test rig using infrared camera was built to test the film cooling performance for a scaled geometry from a real nozzle guide vane. Both cylindrical and fan-shaped holes were tested. To correlate the experimental data, a three-regime based method was developed for predicting the film cooling effectiveness. Based on the blowing ratio, the proposed method divides the film cooling performance in three regimes: fully attached (or no jet lift-off), fully jet lift-off, and the transition regime in between. Two separate correlations are developed for fully attached and full jet lift-off regimes, respectively. The method of interpolation from these two regimes is used to predict the film cooling effectiveness for the transition regime, based on the blowing ratio. It has been found this method can give a good correlation to match the experimental data, for both cylindrical and fan-shaped holes. A comparison with literature was also carried out, and it showed a good agreement.
Turbulence Field Measurements at the Exit of a Combustor Simulator Dedicated to Hot Streaks Generation
Authors: Bacci Tommaso , Facchini Bruno , Picchi Alessio , Tarchi Lorenzo , Koupper Charlie , Champion Jean-Louis 
Published: August 2015

In order to deepen the knowledge of the interaction between modern lean burn combustors and high pressure turbines, a real scale annular three sector combustor simulator has been assembled at University of Florence, with the goal of investigating and characterizing the generated flow field. To generate hot streaks and simulate lean burn combustors behavior, the rig is equipped with axial swirlers, fed by main air flow that is heated up to 531 K, and liners with effusion cooling holes that are fed by air at ambient temperature. The three sector configuration is used to reproduce the periodicity on the central sector.
Ducts of different lengths have been mounted on the swirlers to reduce the interaction of the mainstream with the coolant. Such configurations have been tested, using different measurement techniques, in order to highlight the differences in the resulting flow fields.
The work presented in this paper shows the experimental campaign carried out to investigate the flow turbulence at combustor exit, in isothermal conditions, by means of hot wire anemometry. The goal has been achieved by investigating each test point twice, using an automatic traverse system equipped, in turn, with two split-fiber probes, that allow to measure the velocity components on two planes orthogonal to each other. A method for the time correlation of the signals obtained by the two different tests has been used.
In order to analyse the turbulence decay towards the vanes location, such measurements have been performed on two different planes: one located in correspondence of the combustor exit and the further one placed downstream, in the virtual location of the vanes leading edges.
Unsteady Analysis of Inter-Rows Stator-Rotor Spacing Effects on a Transonic, Low-Aspect Ratio Turbine
Authors: Tang Etienne , Leroy Gilles , Philit Mickaël , Demolis Jacques 
Published: August 2015

The aerodynamic performances of an axial turbine are affected by the distance between the stator and the rotor. Previous studies have shown different trends, depending mainly on whether the turbine is subsonic or not. The present paper aims at improving the understanding of the effect of rows spacing on the flow through a transonic turbine.
A one-stage, low aspect ratio, high pressure turbine case is investigated using CFD. Steady and unsteady phase-lagged RANS computations are performed on this configuration with different inter-blade rows distances. The results are successfully compared with experimental data from a cold air turbine rig. Entropy production balances are used to emphasize the main loss areas and the loss variations caused by changes in inter-blade rows distance. Two techniques are compared for computing these balances, and one of them appears to perform much better. The flow features causing these losses are then identified. Finally, an optimal inter-rows spacing is found. It is a compromise between the losses created by strong stator-rotor interactions at small inter-rows gaps and the losses generated at the endwalls in the inter-rows space at large distances.
Sea Level Performance of a CF-700 Engine Core With Alternative Fuels
Authors: Davison Craig R. , Canteenwalla Pervez , Chalmers Jennifer L. Y. , Chishty Wajid A. 
Published: August 2015

The use of alternative fuels has the potential to enhance energy independence and reduce environmental impact of air travel. It is important to characterize gas turbine operation using such fuels under controlled conditions before implementing them in flight. The performance of a CF-700 engine core was examined in a sea level test facility. The following fuels were tested and will be reported on:
1. Jet A-1 – baseline fuel
2. 100% unblended Hydroprocessed Esters and Fatty Acids (HEFA) synthetic kerosene fuel with aromatics (SKA)
3. 100% unblended Fischer-Tropsch (FT) synthetic paraffinic kerosene (SPK)
4. Blended 50% HEFA-SPK and 50% Jet A-1
Fuel 2 above is an alternative fuel that can potentially be used without blending with conventional fuel. One purpose of the static engine testing was to determine if this fuel was suitable for use on subsequent test flights in a Dassault Falcon 20 aircraft. Engine performance testing was conducted at various power settings for each fuel. Relevant plots of performance are presented, compared and discussed. Transient tests were also performed including slams and chops. Observations of the effects of the different fuels on the engine fuel system are presented as some alternative fuels have the potential to cause seals to shrink and leaks to occur. The leaks observed are noted as are the steps taken to mitigate the problem.
Operational Strategies of Wet Cycle Micro Gas Turbines and Their Economic Evaluation
Authors: Stathopoulos Panagiotis , Paschereit Christian Oliver 
Published: August 2015

The simultaneous expansion of variable renewables and combined heat and power (CHP) plants in Europe has given rise to a discussion about their compatibility. Due to the concurrence of high wind power generation and high heating loads, it has been argued that only the flexible, electricity oriented operation of CHP plants could go along with the extended penetration of renewables in the European energy system.
The current work focuses on the wet cycle simulation of a Turbec T-100. Three operational strategies are applied on the heat and electricity demand data of a public building, to assess the economic and environmental performance of the wet cycle. The operation of the mGT is modeled in ASPEN Plus and the model is validated with data found in literature. The economic aspects of the operational strategies are assessed with a financial model, which takes into account the current CHP policy incentives and price levels. Furthermore, the advantages and drawbacks of wet operation are highlighted by its comparison to the typical heat-driven operation of dry-cycle mGTs, with a reference to the same case study. It is shown that the wet cycle turbines have a higher number of full load equivalent operating hours and can achieve higher investment payback, with minor drawbacks to their overall environmental performance.