bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Evidence: Data Documenting Parental Support for Earlier Sexuality Education
Authors: Barr Elissa M. , Moore Michele J. , Johnson Tammie , Forrest Jamie , Jordan Melissa 
Published: December 2013

ABSTRACTBACKGROUNDNumerous studies document support for sexuality education to be taught in high school, and often, in middle school. However, little research has been conducted addressing support for sexuality education in elementary schools.METHODSAs part of the state Behavioral Risk Factor Surveillance System (BRFSS) Survey administration, the Florida Department of Health conducted the Florida Child Health Survey (FCHS) by calling back parents who had children in their home and who agreed to participate (N = 1715).RESULTSMost parents supported the following sexuality education topics being taught specifically in elementary school: communication skills (89%), human anatomy/reproductive information (65%), abstinence (61%), human immunodeficiency virus (HIV)/sexually transmitted infections (STIs) (53%), and gender/sexual orientation issues (52%). Support was even greater in middle school (62‐91%) and high school (72‐91%) for these topics and for birth control and condom education. Most parents supported comprehensive sexuality education (40.4%), followed by abstinence‐plus (36.4%) and abstinence‐only (23.2%). Chi‐square results showed significant differences in the type of sexuality education supported by almost all parent demographic variables analyzed including sex, race, marital status, and education.CONCLUSIONSResults add substantial support for age‐appropriate school‐based sexuality education starting at the elementary school level, the new National Sexuality Education Standards, and funding to support evidence‐based abstinence‐plus or comprehensive sexuality education.
Experiences of Therapists Trying to Reduce Falls Risk for People With Intellectual Disability
Authors: Pal Jaya , Hale Leigh , Mirfin‐Veitch Brigit 
Published: December 2013

AbstractAlthough it is well established that falling and fall‐related injuries are a problem for many people with intellectual disability (ID), there is an absence of research reporting on the effectiveness of fall prevention strategies to reduce fall risk in this population group. As a starting point to guide the development of research into possible fall prevention strategies for people with ID, the authors interviewed a purposive sample of physiotherapists and occupational therapists currently working for one service organization in New Zealand. To determine the perceptions, experiences, and opinions of therapists in trying to prevent and reduce fall risk for people with ID, the authors conducted a series of semistructured interviews using an open‐ended questioning technique. Data were analyzed using a general inductive approach. Five categories emerged from the interviews: the therapist's roles, successful and unsuccessful strategies, justification of strategies, barriers, and future strategies. Four main fall prevention strategies were identified that therapists thought to be most useful, including environmental modifications, participation in physical activity and exercise, prescription of assistive mobility devices, and education on safe mobility. It was concluded that the experiences and insights of the therapists could provide direction for future research as well as for therapists currently working in the field.
Important Interactional Strategies for Everyday Public Health Nursing Practice
Authors: Porr Caroline J. 
Published: December 2013

AbstractThis Clinical Concepts article concerns the relational tools required by public health nurses to establish relationships with single mothers living on public assistance, mothers who are vulnerable and often stigmatized. The implications of stigmatization for relationship building are highlighted based on previous research investigating how public health nurses working in Canadian jurisdictions establish professional caring relationships with this cohort of mothers. Public health nurses employed interactional strategies including engaging in a positive manner and offering verbal commendations which served as effective relational tools to break through mothers' walls of defensiveness and to resume the dynamic process of relationship building. Building Relationship is a key practice standard for public health nurses and is instrumental to their work at both individual and community levels to improve social determinants of health. The author concludes with recommendations to facilitate building relationships during everyday public health nursing practice.
Validation of a Linearized Navier-Stokes Based Flutter Prediction Tool: Part 1—Numerical Methods
Authors: Kersken Hans-Peter , Ashcroft Graham , Frey Christian , Pütz Oliver , Stüer Heinrich , Schmitt Stefan 
Published: December 2013

This is the first of two papers describing the validation of a tool chain for flutter prediction. This first paper provides an overview of the numerical methods and their verification. The second paper presents the detailed validation of the tool chain on the basis of experimental data obtained from measurements of an annular cascade sector comprising slightly twisted turbine blades.
The tool chain consists of commercial programs for grid generation, structural analysis and the computation of the steady flow, and software developed at DLR for data conversion, aeroelastic preprocessing, and solving the time-linearized RANS equations.
The time-linearized solver computes the unsteady flow in the frequency domain based on the linearization of the RANS equations about a steady solution which, in the process chain presented here, is provided by the commercial solver. We investigate the issues that arise from using different spatial discretization schemes and turbulence models for the computation of the steady and the time-linearized solutions. Results are presented for Standard Configurations 4, 10 and 11, and a freestanding turbine blade from a rear stage of a stationary gas turbine. It is shown that with an appropriate choice of the spatial discretization parameters good agreement with reference data can be obtained.
Numerical Study of a Rotor/Stator Interaction Case Experimentally Simulated With an Industrial Compressor
Authors: Batailly Alain , Legrand Mathias , Millecamps Antoine , Garcin Francois 
Published: December 2013

Higher aircraft energy efficiency may be achieved by minimizing the clearance between the rotating blade tips and respective surrounding casing. A common technical solution consists in the implementation of an abradable liner which improves both the operational safety and the efficiency of modern turbomachines. Recently, unexpected abradable wear removal mechanisms were observed in experimental set-ups and during maintenance procedures. The present study introduces a numerical strategy capable to address this occurrence.
After focusing on the analysis of the experimental results, the good agreement between experimental observations and numerical results is illustrated in terms of critical stress levels within the blade as well as final wear profiles of the abradable liner. New blade designs are also explored in order to assess the impact of blade design on the outbreak of the interaction phenomenon. The prevalence of three dominant parameters in the interaction onset is shown: (1) blade design, (2) abradable material mechanical properties and (3) the need for a global distortion of the casing to synchronize blade-tip/abradable coating contacts.
Crack Initiation Behavior and its Estimation for a Gas Turbine Rotor Based on the EBSD Analysis
Authors: Kobayashi Daisuke , Ito Akihiro , Miyabe Masamichi , Kagiya Yukio , Yoshioka Yomei 
Published: December 2013

Gas turbine rotors made of Ni-base superalloys were sometimes found to have cracks at the dovetail of the first and second stage wheel. In order to maintain the reliability of gas turbine rotors over the long term, in addition to the application of countermeasures such as the shot-peening process, it is essential to confirm the characteristics of crack initiation mechanisms and to predict the possibility of new cracking.
In this paper, first, the case study of crack initiation concerning a wheel dovetail crack has been carried out. Second, to reveal the characteristics of the crack, comparative evaluation between the actual crack and various mechanical fracture samples were conducted by using a scanning electron microscope (SEM) and the electron back-scatter diffraction (EBSD) method which can analyze crystallographic misorientation. As a result, it was found that even in relatively low temperatures, Inconel® Alloy 706 is subjected to brittle grain boundary oxidation when under constant high stress, i.e. a similar phenomenon to stress accelerated grain boundary oxidation (SAGBO), so called hold-time cracking (HTC).
Rotor Dynamics of Overhung Rotors: Hysteretic Dynamic Behavior
Authors: Marin Manuel A. 
Published: December 2013

Overhung-configuration rotors are commonly used in the oil, gas and process industries. Examples of this type of equipment include power turbines, Fluid Catalytic Cracking (FCC) expanders, turbochargers and pipeline boosters. Generally, in overhung-configuration rotors, the mass concentration is near the bearing on the overhung end, so the rotor dynamics behavior of these overhung-configuration rotors is different than other equipments that have their mass concentrations between the bearing spans, such as multistage compressors.
Among the more important characteristics that directly affect the rotor dynamics of the overhung rotors are gyroscopic effects on the higher modes and the fluid-film journal bearings. Gyroscopic effects are more significant in overhung configurations because of the relatively large overhung mass. These rotors also have a short bearing span and a relatively stiff shaft, so the first two modes are characterized by rigid body motion, as long as the bearing supports are rigid, as in most pipeline boosters. For pipeline boosters it would be typical to describe them as subcritical machines. If the bearing supports are not rigid, as at the disc end of power turbines and FCC expanders, then the first mode can be amplified, and it would not be unusual to describe them as supercritical machines. This paper will assume that the bearing supports are rigid, as in most pipeline boosters.
A phenomenon observed in overhung rotors is known as the synchronous thermal instability or “Morton Effect”. The Morton Effect occurs when synchronous vibration produces non-uniform heating of the shaft under the bearing, leading the shaft end to develop a thermal bow. It is typical for this to happen on the overhung end of the rotor, where there is more unbalance to react with any thermal bow.
The paper examines the hysteretic dynamic behavior observed in an overhung rotor mounted on tilting pad journal bearings, presenting a series of analysis using state-of-the-art rotor dynamics programs, and comparing analytical results with measurements, handling possible variables associated with synchronous “hysteresis” vibration.
Forced Response in Axial Turbines Under the Influence of Partial Admission
Authors: Fridh Jens , Laumert Björn , Fransson Torsten 
Published: December 2013

High cycle fatigue (HCF) due to unforeseen excitation frequencies or due to under predicted force magnitudes, or a combination of both causes control stage failures for steam turbine stakeholders. The objectives of this paper is to provide an extended design criteria toolbox and validation data for control stage design based on experimental data, with the aim to decrease HCF incidents for partial admission turbines.
The upstream rotor in a two stage air test turbine is instrumented with pressure transducers and strain gauges. Admission degrees stretching from 28.6% to 100% as one or two admission arcs are simulated by blocking segmental arcs immediately upstream of first stator vanes by aerodynamically shaped filling blocks. Sweeps across a speed range from 50 to 105% of design speed are performed at constant turbine pressure ratio during simultaneous high speed acquisition. A forced response analysis is performed and results presented in Campbell diagrams.
Partial admission creates a large number of low engine order forced responses because of the blockage, pumping, loading and unloading processes. Combinations of the number of rotor blades and low engine order excitations are the principal sources of forced response vibrations for the turbine studied herein.
Altering the stator and/or rotor pitches will change the excitation pattern. A relation between the circumferential lengths of the admitted and non-admitted arcs that dictates the excitation forces is observed that may serve as a design parameter.
Performance Characteristics of an Operating Supercritical CO2 Brayton Cycle
Authors: Conboy Thomas , Wright Steven , Pasch James , Fleming Darryn , Rochau Gary , Fuller Robert 
Published: December 2013

Supercritical CO2 (S-CO2) power cycles offer the potential for better overall plant economics due to their high power conversion efficiency over a moderate range of heat source temperatures, compact size, and potential use of standard materials in construction [1,2,3,4]. Sandia National Labs (Albuquerque, NM, US) and the US Department of Energy (DOE-NE) are in the process of constructing and operating a megawatt-scale supercritical CO2 split-flow recompression Brayton cycle with contractor Barber-Nichols Inc. [5] (Arvada, CO, US). This facility can be counted among the first and only S-CO2 power producing Brayton cycles anywhere in the world.
The Sandia-DOE test-loop has recently concluded a phase of construction that has substantially upgraded the facility by installing additional heaters, a second recuperating printed circuit heat exchanger (PCHE), more waste heat removal capability, higher capacity load banks, higher temperature piping, and more capable scavenging pumps to reduce windage within the turbomachinery. With these additions, the loop has greatly increased its potential for electrical power generation — according to models, as much as 80 kWe per generator depending on loop configuration — and its ability to reach higher temperatures.
To date, the loop has been primarily operated as a simple recuperated Brayton cycle, meaning a single turbine, single compressor, and undivided flow paths. In this configuration, the test facility has begun to realize its upgraded capacity by achieving new records in turbine inlet temperature (650°F/615K), shaft speed (52,000 rpm), pressure ratio (1.65), flow rate (2.7 kg/s), and electrical power generated (20kWe). Operation at higher speeds, flow rates, pressures and temperatures has allowed a more revealing look at the performance of essential power cycle components in a supercritical CO2 working fluid, including recuperation and waste heat rejection heat exchangers (PCHEs), turbines and compressors, bearings and seals, as well as auxiliary equipment. In this report, performance of these components to date will be detailed, including a discussion of expected operational limits as higher speeds and temperatures are approached.
Detailed Compressor Degradation Effect Modeling for Single Blade Rows While Assessing Its Local and Overall Consequences
Authors: Kappis Wolfgang , Guidati Gianfranco 
Published: December 2013

The detailed local and overall aerodynamic impact due to the basic degradation mechanisms of changed surface roughness (fouling), caused by deposits on the blading surface and/or corrosion, leading edge deformation, caused by erosion, and clearance increases, caused by rubbing due to structural ovalization and/or rotor sagging are assessed. The generic aerodynamic impact of these effects is assessed in a first step by detailed local issue focused CFD analyses. The resulting trend changes in the aerodynamic behavior for every individual blade row are in a second step transferred to an empirical model for loss and deviation prediction of a 1-dim. compressor mid-streamline code. This tool is used to predict row specific and compressor overall aerodynamics for a wide range of operating points. Applying the generic trend changes due to degradation therefore provides information on the local and overall compressor mismatching. Details on the process of assessing and transferring these physical consequences are shown and discussed.
The different degradation contributors are assessed individually and in combination. Beneath detailed aerodynamic changes, e.g. stage pressure ratios and feed pressures, resulting effects on the compressor map, reflecting mass flow, efficiency and operating range changes are considered. Some typical overall engine degradation measurements are used to validate the numerical assessments and to draw some final conclusions.
For end-users the conclusions of this paper can be used to optimize site-specific operation cycles, based on corresponding field findings and by application of the theoretical conclusions derived in this paper. This can finally trigger a re-assessment of washing intervals and washing types to be executed and/or even to give special focus on certain blade rows during major overhauls/inspections in respect to hand cleaning or even blading exchange.
Development and Experimental Performance Verification of a Magneto-Aerostatic Bearing for Cartridge of Dental Handpieces
Authors: Ting Guan-Chung , Huang Kuang-Yuh , Chang Keng-Ning 
Published: December 2013

Bearings for high-speed rotors are the key component of dental handpieces. The friction induced by conventional ball bearings restricts its speed and reduces its efficiency. In order to significantly improve the efficiency of dental handpieces, a mini-type cartridge that integrates a turbine and a spindle with radial aerostatic bearings and axial passive magnetic bearings has been ingeniously designed and realized. Around the rotating spindle, there is a high-pressured air film built up by a pair of radial aerostatic bearings, and magnet rings are applied to create repulsive forces to axially support the rotating spindle. The high-pressured air film comes from the specifically designed separable orifice restrictors, which can be easily and precisely manufactured. Frictionless bearing effect can be achieved by aerostatic principle, and the magnetic principle is applied to create large repulsive force against the axial working force. A tri-directional air inlet is designed to reduce radial loading force of a spindle during working. The modularized form of the magneto-aerostatic bearing allows it to be easily assembled and replaced in the very compact space of a mini-type cartridge.
Through analytical simulations with fluid-dynamics software (CFD) and experiments, the magneto-aerostatic bearing is optimized to bring out efficient performance in its limited space. The experiments have verified that its noise level is 15dB lower than the conventional cartridge with ball bearings, and its startup air pressure is reduced from 0.4 bar to 0.1 bar. Under the same operation conditions, the newly developed cartridge with magneto-aerostatic bearings creates twice higher speed than that of the conventional one.
A Superposition Approach for Time-Dependent Fatigue Crack Growth
Authors: Ma Fashang 
Published: December 2013

High temperature fatigue crack growth is a combination of fatigue, creep and environmental attack, which greatly enhance fatigue crack growth. In order to understand the damage mechanisms and develop a physically based crack growth model, systematic experimental research has been conducted under various loading conditions for different specimen geometries made from a high strength nickel alloy.
Test results from this work showed that time-dependent fatigue crack growth rates differ significantly from those observed in conventional fatigue crack growth tests. Crack geometry and loading history significantly affect fatigue crack growth rate. These results suggest the need for a change in the K based superposition approach for time-dependent crack growth modeling.
A phenomenological model has been developed to predict time-dependent crack growth under various loading histories and crack geometries. In this model an effective stress intensity factor is defined to account for the effects of constraint loss of fracture mechanics due to crack-tip plasticity, and the creep stress relaxation on stress intensity factor. It is found the model can accurately predict the dwell crack growth rates for different crack geometries under various loading conditions.
Design for Global Sourcing for Gas Turbine Engine Support to Achieve Design Harmonization
Authors: Tang Yucheng , Zhao Zuozhi , Li Peng , Sun Junling , Song Jinyu 
Published: December 2013

Fierce competition, fluctuating market and opportunities in emerging market are forcing companies to structure product design globally to reduce cost and improve efficiency. However, the solutions to old issues are always accompanied by new challenges. Traditional design flow is struggling to catch up with the pace of customer requirement. And mixed global design teams, composed of senior and junior designers, are trying to design with uniform quality.
A real case occurred was that an experienced designer provides a DIN solution when the manufacturing requirement was ASTM, which results additional round of product design. In order to reduce those risks and overcome the challenges, a multiobjective optimization framework for gas turbine engine support was developed to shorten the product development and find an optimal design solution. To manage the risks arising from sourcing, a concept of design for global sourcing (DfGs) was proposed and implemented by incorporating design standards database and supply chain interface during preliminary design stage. Three practical design cases were performed to validate the proposed method. The results demonstrated: 1) Cost and product development cycle was sharply reduced; 2) Design flexibility was achieved by DfGs concept; 3) Trade-off among conflicting design objectives was accomplished by cost estimation model.
Novel Vertical-Axis Wind Turbine With Articulated Blading
Authors: Jericha H. , Göttlich E. , Selic T. , Sanz W. 
Published: December 2013

In this work a novel vertical-axis wind turbine is presented which can catch a wide range of wind velocities at high efficiencies.
The wind turbine consists of a rotatable horizontal platform, where three symmetric blades are arranged which rotate with half of the platform angular speed but in opposite direction relative to it. The rotation of the blades allows them to adapt to the varying angle of attack of the wind during one revolution of the platform. The important characteristic is the design feature that the blades are inclined outwards to the vertical axis of the platform by an angle of about 20 deg. The inclination leads to an increased circumferential velocity along the blade span, so that the increasing wind velocity with height can be better captured. Also the chord length of the blades increases with the spanwise position.
In order to better utilize the wind flow, guide vanes can be arranged which increase the flow to those blades currently moving with the wind and in return flow can even give proper windshield.
The articulated blades are connected to the horizontal platform via a special planetary bevel gear box, so that the relative rotational movement of them is controlled by the rotating platform, in fact a rotating gear box. This unit itself is connected to a generator thus producing electrical energy. The wind turbine can be tracked to a changed wind direction by means of rotating the stationary center bevel-gear wheel, which at given wind direction is then kept at constant position.
In this paper the design of wind turbine is described in detail and the advantages of the novel vertical-axis turbine are discussed. First CFD investigations of a 2D section without guide vanes are presented. They show that maximum power can be achieved for a wide range of speed ratios. The calculated power coefficient is about 0.36, an interesting value for vertical-axis wind turbines.