bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screening executive function and global cognition with the Nine‐Card Sorting Test: healthy participant studies and ageing implications
Authors: Vigliecca Nora Silvana , Baez Sandra 
Published: March 2015

AbstractBackgroundThe Nine‐Card Sorting Test provides valid and reliable scores when screening executive function, intelligence, and academic achievement. It is also useful for detecting cognitive impairment and dementia in the elderly and for assessing disease evolution and treatment effectiveness. It deals with three non‐verbal sorting principles, individually and in pairs. The presence of risk in the ability to discover and organize visual logical stimuli is explored.ObjectivesThis study aimed to describe performance on the Nine‐Card Sorting Test in a non‐clinical sample, to analyze the effect of demographic variables, and to propose suitable (i.e. the simplest and most homogeneous) cut‐off points for possible deficits. Combinations in pairs (double arrays) were assessed (range: 0–3).ResultsSignificant effects of age and education were observed, but no interactions among the demographic variables were seen. Differences between the second and third levels of education and between men and women were not significant. The simplest cut‐off points were as follows: (i) the median for people younger than 45 years old was 2, independent of educational level; (ii) the median for people older than 74 years old was 1, independent of educational level; and (iii) the median for people aged 45–74 years old was 1 for the first level of education and 2 for higher levels of education.ConclusionBy considering both the statistical nature of the present dependent variable (number of completed categories) and the clear‐cut performance of the different samples studied, this neuropsychological test can be defined as a categorical screening for executive function and global cognition. This is advantageous for reporting risk. Of the whole sample, the 25th percentile (score = 1) represented a valid index for possible deficits. Ageing questions are highlighted. The test is also fruitful for studies on visuospatial organization and its facilitatory and inhibitory mechanisms.
Autopsy‐confirmed hippocampal‐sparing Alzheimer's disease with delusional jealousy as initial manifestation
Authors: Fujishiro Hiroshige , Iritani Shuji , Hattori Miho , Sekiguchi Hirotaka , Matsunaga Shinji , Habuchi Chikako , Torii Youta , Umeda Kentaro , Ozaki Norio , Yoshida Mari , Fujita Kiyoshi 
Published: March 2015

AbstractAlzheimer's disease (AD) is clinically characterized by gradual onset over years with worsening of cognition. The initial and most prominent cognitive deficit is commonly memory dysfunction. However, a subset of AD cases has less hippocampal atrophy than would be expected relative to the predominance of cortical atrophy. These hippocampal‐sparing cases have distinctive clinical features, including the presence of focal cortical clinical syndromes. Given that previous studies have indicated that severe hippocampal atrophy corresponds to prominent loss of episodic memory, it is likely that memory impairment is initially absent in hippocampal‐sparing AD cases. Here, we report on a patient with an 8‐year history of delusional jealousy with insidious onset who was clinically diagnosed as possible AD and pathologically confirmed to have AD with relatively preserved neurons in the hippocampus. This patient had delusional jealousy with a long pre‐dementia stage, which initially was characterized by lack of memory impairment. Head magnetic resonance imaging findings showed preserved hippocampal volume with bilateral enlarged ventricles and mild‐to‐moderate cortical atrophy. Head single‐photon emission computed tomography revealed severely decreased regional cerebral blood flow in the right temporal lobe. The resolution of the delusion was attributed to pharmacotherapy by an acetylcholinesterase inhibitor, suggesting that the occurrence of delusional jealousy was due to the disease process of AD. Although the neural basis of delusional jealousy remains unclear, this hippocampal‐sparing AD case may be classified as an atypical presentation of AD.
Family support, anticipated support, negative interaction, and psychological well‐being of older parents inThailand
Authors: Thanakwang Kattika 
Published: March 2015

AbstractBackgroundA number of studies have consistently indicated that family support has a powerful impact on older parents' well‐being, but little is known about the effects of anticipated support and negative interaction on psychological well‐being. The present study attempted to examine the relationships between family support, negative interaction, and psychological well‐being in older Thai parents.MethodsThe sample included 578 elderly parents aged 60 years and older. Multiple regression models were employed to determine whether received support, anticipated support, and negative interaction influence older parents' well‐being.ResultsFindings revealed that greater emotional and instrumental support received from family members and anticipated support were significantly associated with a greater sense of older parents' psychological well‐being. However, psychological well‐being was lower for those with more negative family interactions.ConclusionThe results suggest that filial piety and family solidarity should be considered when developing elder care policy and interventions to promote psychological well‐being.
Subjective memory impairment and well‐being in community‐dwelling older adults
Authors: Zuniga Krystle E. , Mackenzie Michael J. , Kramer Arthur , McAuley Edward 
Published: March 2015

AbstractBackgroundThe relationship between subjective memory impairment (SMI), future cognitive decline, and negative health status provides an opportunity for interventions to reduce memory complaints in high‐risk groups. This study aimed to examine the relationship between SMI and indicators of well‐being in older adults enrolled in an exercise trial. Additionally, the study examined whether two different modes of exercise training, aerobic walking and non‐aerobic flexibility, toning, and balance, differentially influenced subjective memory across the trial.MethodsCommunity‐dwelling older adults (n = 179, mean age = 66.4 years) were randomly assigned to a walking or flexibility, toning, and balance group for 12 months. Subjective memory, happiness, perceived stress, and symptom reporting were measured at baseline, 6 months, and 12 months.ResultsA main effect of subjective memory indicated that individuals with the fewest memory complaints had lower perceived stress (P < 0.001), lower physical symptom reporting (P < 0.001), and higher happiness levels (P < 0.001) across all measurement occasions. Both main and interaction effects of time and group on SMI were not significant, suggesting SMI remained stable across the intervention and was not significantly impacted by participation in exercise training.ConclusionsSMI was not responsive to exercise interventions, and the relationship between SMI and negative well‐being demonstrates a need for interventions to reduce memory complaints in high‐risk groups.
A structural model of age, grey matter volumes, education, and personality traits
Authors: Kitamura Soichiro , Yasuno Fumihiko , Yamamoto Akihide , Kazui Hiroaki , Kudo Takashi , Matsuoka Kiwamu , Kiuchi Kuniaki , Kosaka Jun , Nagatsuka Kazuyuki , Iida Hidehiro , Kishimoto Toshifumi 
Published: March 2015

AbstractBackgroundWhen the relationship between ageing and changes in personality traits is considered, it is important to know how they are influenced by biological and environmental factors. The present study examined the relationships between various factors associated with the effect of ageing on personality traits, including structural changes of the brain and environmental factors such as education.MethodsWe recruited 41 healthy subjects. We administered the NEO Five‐Factor Inventory to assess personality factors. Magnetic resonance imaging was performed, and regional grey matter (GM) volumes were obtained. We identified associations in the correlation analysis of age, cerebral GM volume, years of education, and the personality trait of openness. Path analysis was used to estimate the relationships among these factors.ResultsThe path analysis model of age, GM volume, years of education, and the personality trait of openness revealed that age has an indirect negative association with openness through GM volume and years of education. Ageing was related to a decrease in GM volume, which was in turn related to a decrease in the openness score. Older subjects generally had fewer years of education, which was related to a lower openness score.ConclusionsMaintaining openness against the effects of ageing is desirable, and our results imply that interventions against age‐related cerebral atrophy and the promotion of opportunities for higher education may contribute to the development and stability of a healthy personality during the adult life course.
Status of the Automotive Ceramic Gas Turbine Development Program
Authors: Itoh Takane , Kimura Hidetomo 
Published: March 2015

The seven-year program, designated “Research and Development of Automotive CGT” commenced in June 1990 with the object of demonstrating the potential advantages of ceramic gas turbine engines for automotive use. This program has been being conducted by the Petroleum Energy Center (PEC) with the support of the Ministry of International Trade and Industry. The engine demonstration project in this program is being handled by a team from the Japan Automobile Research Institute, Inc., (JARi).
This paper describes the activities of the first year of the seven-year program, and includes the project goals and objectives, the program schedule, and the first-stage design of an experimental automotive ceramic gas turbine (CGT) engine and its components. The basic engine is a 100kW, single-shaft gas turbine engine having a turbine inlet temperature of 1350°C and a rotor speed of 110,000 rpm. The primary engine components including the turbine hot flow path components have been designed using monolithic ceramics and are scheduled to be produced during the second year of the program.
A Numerical Investigation Into the Nozzle Flow of High By-Pass Turbofans
Authors: Zimmermann H. , Katheder K. , Jula A. 
Published: March 2015

Numerical investigations for the interacting flow fields of primary and secondary nozzles confirm, that for high by-pass turbofans there is a strong influence of the fan flow on the discharge and thrust coefficients of the core nozzle and of the fan afterbody shape on the coefficients of the fan nozzle.
After a review of standard methods two new parameters to correlate the thrust of different concepts are proposed and investigations into flight conditions are put forward.
Several nozzle coefficients derived from the integrated velocity profiles and the static pressure field are necessary to assess the quality of nozzle flow.
Turbine Rebuild Effects on Gas Turbine Performance
Authors: MacLeod J. D. , Drbanski B. 
Published: March 2015

The Engine Laboratory of the National Research Council of Canada (NRCC), with the assistance of Standard Aero Ltd., has established a program for the evaluation of component deterioration on gas turbine engine performance. As part of this project, a study of the effects of turbine rebuild tolerances on overall engine performance was undertaken. This study investigated the range of performance changes that might be expected for simply disassembling and reassembling the turbine module of a gas turbine engine, and how these changes would influence the results of the component fault implantation program.
To evaluate the effects of rebuilding the turbine on the performance of a single spool engine, such as Allison T56 turboprop engine, a series of three rebuilds were carried out. This study was performed in a similar way to a previous NRCC study on the effects of compressor rebuilding. While the compressor rebuild study had found performance changes in the order of 1% on various engine parameters, the effects of rebuilding the turbine have proven to be even more significant. Based on the results of the turbine rebuild study, new methods to improve the assurance of the best possible tolerances during the rebuild process are currently being addressed.
This paper describes the project objectives, the experimental installation, and the results of the performance evaluations. Discussed are performance variations due to turbine rebuilds on engine performance characteristics. As the performance changes were significant, a rigorous measurement uncertainty analysis is included.
Development of a Regenerator for an Automotive Gas Turbine Engine
Authors: Sayama Junichi , Morishita Teru 
Published: March 2015

It is vital to accurately estimate the temperature effectiveness and pressure loss of the regenerator when designing a gas turbine engine because these characteristics basically determine the size, weight, and fuel consumption of the regenerative gas turbine engine. In operation of an actual engine, regenerators often fail to attain the characteristics predicted by conventional methods, because there are many performance-reducing irregularities such as the non-uniform velocity distribution of gases flowing into the core.
In this paper, a prediction method that is based on data from actual engine tests is examined as a way to predict regenerator temperature effectiveness and pressure losses when there are causes for deterioration of these characteristics. This method resulted in a system, taking the deterioration of these characteristics into consideration as they occur in an actual engine, that represents temperature effectiveness and pressure loss as the function of core specifications such as the core size and the core matrix.
This prediction method was then used to predict the regenerator characteristics of actual engines with more than satisfactory results (The accuracy is ±1.25% for temperature effectiveness and ±4% for pressure loss).
Electromechanical Measurement of Turbomachinery Blade Tip-to-Casing Running Clearance
Authors: Sheard A. G. , Turner S. R. 
Published: March 2015

It is difficult to make a reliable measurement of running clearance in the hostile environment over the blading of modern gas turbines. When the engine manufacturers require the measurement to be made during tests lasting many hours, or even days, measurement system ruggedness and reliability are of primary importance.
This paper describes how a second generation tip clearance measurement system of much reduced size and weight was developed. The reduction of size and weight facilitates the use of this measurement system for blade tip-to-casing measurements on all engine development tests from rig to flight worthy engines. During the course of commissioning, the measurement system was tested first in the laboratory, then on progressively more demanding test vehicles. The final test was on the high pressure turbine of a modern military full scale development single spool core. During the course of this test, the mean engine Turbine Entry Temperature through the blading over which clearance was measured, exceeded 1800 K and is typical of the applications for this second generation system.
Three-Dimensional Inviscid Flow Computations in a Spatial Turbopump Inducer Using a Distributed Loss Model
Authors: El Ghazzani E. M. , Bois G. , Geai P. , Leboeuf F. 
Published: March 2015

A Clebsch formulation, completely equivalent to the Euler equations is implemented from an Eulerian type variational principle. It leads to the decomposition of the velocity field into a potential and a rotational part and, thus, provides a unified solution scheme for potential and Euler equations.
Although based on an inviscid flow model, this formulation includes a loss scheme.
The numerical method uses a finite element discretization. Particular treatment of convection terms allows a low numerical diffusion. A pseudo time evolution enables a better stability behaviour.
Numerical calculations have been performed on an industrial configuration of spatial turbopump. Different comparisons ere showed between measurements, calculations without and with distributed losses.
Design and Rotor Performance of a 5:1 Mixed-Flow Supersonic Compressor
Authors: Mönig R. , Elmendorf W. , Gallus H. E. 
Published: March 2015

In consideration of further jet-engine developments required by applications for supersonic travel aircraft, airbreathing propulsion of space vehicles or only the improvement of conventional high performance turbo engines, highly loaded supersonic compressors seem to meet the future demands. Particularly mixed-flow compressor stages with moderate supersonic rotor- and stator inlet flow reveal the potential of high pressure rise and massflow as well as favorable performance characteristics and efficiency.
The first part of this paper presents analytical considerations for mixed-flow supersonic compressors with strong shock waves. This theoretical approach proves to be of essential importance besides established design tools in order to ensure safe rotor and stage operation in accordance with the design objectives. In this context, the conditions for shock wave stabilization within a diagonal rotor passage are discussed in detail for design and off-design rotational speeds.
The main part of this paper, however, presents the results and flow analysis obtained by extensive experimental investigations of the designed mixed-flow compressor rotor. The investigations were restricted to operation without stator in order to strictly separate rotor performance from rotor-stator interactions.
The results reveal the design goals to be met in general. Massflow, total pressure rise and efficiency in particular show a good agreement with the design properties for near-surge operation at design and off-design conditions.
Fatigue Life Estimation Procedure for a Turbine Blade Under Transient Loads
Authors: Vyas N. S. , Rao J. S. 
Published: March 2015

Fatigue analysis and consequent life prediction of turbomachine blading requires the stress load history of the blade. A blade designed for safe operations at particular constant rotor speeds may, however, incur damaging stresses during Start-up and Shut-down operations. During such operations the blade experiences momentary resonant stresses while passing through the criticals which may lie in the speed range through which the rotor is accelerated. Fatigue due to these transient influences may cumulate to lead to failure.
In this paper a technique for fatigue damage assessment during variable speed operations is presented. Transient resonant stresses for a blade with nonlinear damping have been determined using a numerical procedure. A fatigue damage assessment procedure is described. The fatigue failure surface is generated on the S-N-mean stress axes and Miner’s Rule is employed to estimate the cumulation of fatigue.
Active Stabilization of Compressor Instability and Surge in a Working Engine
Authors: Williams J. E. Ffowcs , Harper M. F. L. , Allwright D. J. 
Published: March 2015

We have applied feedback control to the compressor of a 45kW auxiliary power unit. Using this, the engine is able to deliver more than 10% extra shaft power before surge occurs.
We achieve control by suppressing a non-axisymmetric flow phenomenon in the diffuser of the centrifugal compressor. Control is effected by modulating a small extra air flow into the impeller.
We present results of modelling and analysis which suggest that linear feedback control will be sufficient to stabilize a compression system, even when both axisymmetric surge and rotating stall are present as possible instabilities.
Experimental Analysis of Transonic Flow Through the Variable Nozzle of a Radial Inflow Turbine
Authors: Gallus H. E. , Lingner U. , Ispas I. 
Published: March 2015

The wide range of applications for radial inflow turbines is the reason for an increasing interest in this type of machines in the recent years. An appropriate method to achieve good efficiencies under different operating conditions is the use of variable nozzle vanes. Because of the limited knowledge of the flow phenomena involved, simple models are used for aero-thermodynamical machine design.
A research program was initiated to experimentally study the flow field in a transonic radial nozzle cascade. An air test rig with variable nozzle vanes, derived from an industrial radial inflow turbine, was used for the tests. In this rig no rotor was installed in order to study the flow in the nozzles without any influence of this element. Static pressure distributions have been measured on the vane suction and pressure surfaces and on the shroud endwall within the blading and downstream of the nozzles. Results are presented for different pressure ratios and nozzle setting angles. The experimental results are compared with numerical calculations for inviscid flow based on the two-dimensional Euler equations.
Markov Fatigue in Single Crystal Airfoils
Authors: Annis Charles , De Luca Daniel P. 
Published: March 2015

This paper considers the influence of microstructure on macrobehavior in single crystal airfoils by treating the micromechanics of damage accumulation as a Markov process. Single Crystal Fatigue (SCF) is a result of several, simultaneous (competing), damage mechanisms, which are selectively favored by particular combinations of external conditions. As with any real physical process, SCF is also influenced by a stochastic component. This probabilistic influence can be exploited to help explain the macrobehavior.
We begin with a description of single crystal materials and how they differ from more conventional (isotropic) alloys. Relationships are suggested among the more probable of several competing microstructural damage mechanisms and specific rate-controlling parameters. The states of microstructural damage are then described and catalogued, and the various avenues of damage accumulation are investigated. Next, the Markov paradigm is reviewed as it applies to these materials. Finally, a Markov model is presented to describe the rather complex behavior observed in single crystals, and its use in lifing gas turbine engine airfoils is discussed.