bluuebunny/crossref_metadata_2025 huggingface dataset:
Facial Pain Radiating Upwards: Could the Pain of Epicrania Fugax Start in the Lower Face?
Authors: Cuadrado María‐Luz , Aledo‐Serrano Ángel , Jiménez‐Almonacid Justino , de Lera Mercedes , Guerrero Ángel L.
Published: December 2014

Background

Epicrania fugax (EF) is characterized by painful paroxysms starting in a particular area of the head, and rapidly radiating forwards or backwards through the territories of different nerves. In former clinical descriptions, the pain moved between the posterior scalp (C2) and the frontal or periorbital area (V1), either in forward or backward direction.

Methods

We report 5 patients with a paroxysmal EF‐type pain starting in the lower face (V2 or V3) and radiating upwards.

Results

In each patient, the pain stemmed from the cheek (n = 1), the upper lip (n = 2) or the chin and mandibular area (n = 2), and then moved up to the forehead or the scalp with linear trajectory. Pain intensity was moderate (n = 1) or severe (n = 4), and pain quality was stabbing (n = 2) or electric (n = 3). The duration of attacks was very brief, lasting 1 to a few seconds. Three patients had ocular or nasal autonomic accompaniments, and 3 had triggers.

Conclusions

There seems to be a facial variant of EF. These observations could not only expand the clinical spectrum of EF but also enlarge the differential diagnosis of facial pain.
Epidemiology, methodological and reporting characteristics of systematic reviews of nursing interventions published in China
Authors: Shi Chunhu , Zhu Lin , Wang Xue , Qin Chunxia , Xu Qi , Tian Jinhui
Published: December 2014

The importance of systematic reviews (SRs) of nursing interventions' impact on practice makes their methodological quality and reporting characteristics especially important as it directly influence their utility for clinicians, patients and policy makers.The study aims to assess the methodological quality and reporting characteristics of SRs of nursing interventions in Chinese nursing journals. Three Chinese databases were searched for SRs of nursing interventions from inception to October 2011. The assessment of multiple systematic reviews (AMSTAR) and Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) statements were used to assess methodological quality and reporting characteristics. Seventy‐four SRs were included. The proportion of SRs complying with AMSTAR checklist items ranged from 0% to 82.4%. No SRs reported an ‘a priori’ design or conflict of interest. Only four items were found to be reported in more than 50% of the SRs: a list of included and excluded studies, the scientific quality of included studies, the appropriate use of methods to combine findings, and formulating conclusions appropriately. The majority of SRs of nursing interventions in China had major methodological and reporting flaws that limited their value to guide decisions. Chinese authors and journals should adopt and keep up with the AMSTAR and PRISMA statements to improve the quality of SRs in this field.
Dynamic Social Security: A necessary condition for inclusive societies and economic development
Authors: Matijascic Milko , McKinnon Roddy
Published: December 2014

This special double issue of the International Social Security Review addresses the question of the essential roles that national social security systems play in contributing to social and economic objectives and does so through the lens of the Dynamic Social Security conceptual framework. In 2007, the International Social Security Association adopted Dynamic Social Security as the strategic concept to guide its actions. The concept aims to positively influence two outcomes: improvements in social security coverage and improvements in social security administration. The set of papers comprising this issue tackle questions relating primarily to the former. On the basis of country examples, the broad aim of this special issue is to take stock of the strategic concept and its “dimensions” as a framework to guide the sustainable development of social security systems.
Revisiting ISSA's Dynamic Social Security: 2007–2014, and beyond
Authors: McKinnon Roddy , Brimblecombe Simon , McClanahan Shea , Orton Ian
Published: December 2014

The International Social Security Association's (ISSA) Dynamic Social Security conceptual framework has been developed as a tool to identify and analyse current and emerging challenges in social security policy and administrative practice and to guide decision‐makers in developing effective and sustainable responses to these. The longer‐term core objective of the framework is to help extend social security coverage to all through the development of effective social security systems that contributed to socially inclusive and economically productive societies. As revealed by an examination of the ISSA's work priorities, perceptions of the framework have evolved over time. In some instances greater emphasis has been given by the Association to policy analysis, especially in support of the objective of coverage extension. More recently the emphasis has been placed on the practical necessity to support the development of higher performing social security administrations; a core mission objective of the ISSA. In looking to identify future challenges (megatrends) that hold the potential to impact negatively upon social security programmes and administrations, and to develop appropriate responses to these, the ISSA should keep sight of the fact that Dynamic Social Security has an essential analytical role as well as a practical one.
Investing in people to promote activation and empowerment: The case of Denmark and lessons for other countries
Authors: Ploug Niels
Published: December 2014

Danish labour market policies and the Danish flexicurity model were feted during the 1990s when active labour market policies combined with economic policies were able to revitalize the Danish economy and to reduce unemployment from 12.0 per cent to 1.4 per cent by mid‐2008. This article explains the background for this development, explains the major features of the Danish flexicurity model, and uses this to explain recent reform developments in Denmark. Investing in people and decentralization of the implementation of policies are important features of the relative success of Denmark's policies. The importance of taking the individual's competences and labour market experience into consideration as well as the importance of adapting active labour market polices to needs in the local labour market are lessons to be drawn from policy developments in Denmark. The article underlines that Denmark's policies are seen as structural policies that seek to adapt structures in the labour market, social benefit system and educational system to future challenges – and that for structural policies to be successful their timing with economic policies is important. This timing is thought to have been successful the 1990s, but it remains to be seen if this has been so in relation to the most recent reforms.
Towards Dynamic Social Security in South Korea
Authors: Shin Dong‐Myeon
Published: December 2014

Since the 1997 economic crisis, the Republic of Korea has seen considerable progress in its social security system along with relatively high economic growth. The social security system has been reformed to become more redistributive and comprehensive. Nevertheless, the country has experienced growing income inequality and poverty, raising future concerns about the sustainable growth of the national economy. The deterioration in welfare outcomes can be explained as a result of socioeconomic structural changes, including globalization, post‐industrialization and an ageing society. Another important reason is that the social security system has not effectively addressed increasing income inequality reflecting the dualism of the labour market: there are many irregular and self‐employed workers who are not covered by social security programmes. With the social security system faced with institutional difficulties in coping with increasing social risks driven by the impacts of socioeconomic and structural changes, reform is necessary to enhance social cohesion against growing labour market inequality. There is a need for “Dynamic Social Security” to provide an institutional foundation which supports the virtuous circular relationship between economic growth and distribution.
Dynamic Social Security: Taking stock
Authors: Matijascic Milko , McKinnon Roddy
Published: December 2014

To conclude this special double issue, this article addresses four questions related to the strategic pursuit of, what the ISSA calls, Dynamic Social Security (DSS). Based on the evidence of the presented national case studies, social security policy reform priorities differ depending on the level of national economic development, the maturity of the social security system and issues of political economy. Against this backdrop, it is concluded that while general reform trends may be consistent with the objectives defined by DSS, there is important – and often appropriate – divergence across national social security practices.
Evaluation of the Diagnostic Accuracy of Conventional 2‐Dimensional and 3‐Dimensional Computed Tomography for Assessing Canine Sacral and Pelvic Fractures by Radiologists, Orthopedic Surgeons, and Veterinary Medical Students
Authors: Stieger‐Vanegas Susanne M. , Senthirajah Sri Kumar Jamie , Nemanic Sarah , Baltzer Wendy , Warnock Jennifer , Hollars Katelyn , Lee Scott S. , Bobe Gerd
Published: December 2014

Objective

To determine, using 3 groups of evaluators of varying experience reading orthopedic CT studies, if 3‐dimensional computed tomography (3D‐CT) provides a more accurate and time efficient method for diagnosis of canine sacral and pelvic fractures, and displacements of the sacroiliac and coxofemoral joints compared with 2‐dimensional computed tomography (2D‐CT).

Study design

Retrospective clinical and prospective study.

Animals

Dogs (n = 23): 12 dogs with traumatic pelvic fractures, 11 canine cadavers with pelvic trauma induced by a lateral impactor.

Methods

All dogs had a 2D‐CT exam of the pelvis and subsequent 3D‐CT reconstructions from the 2D‐CT images. Both 2D‐CT and 3D‐CT studies were anonymized and randomly presented to 2 veterinary radiologists, 2 veterinary orthopedic surgeons, and 2 veterinary medical students. Evaluators classified fractures using a confidence scale and recorded the duration of evaluation for each modality and case.

Results

3D‐CT was a more time‐efficient technique for evaluation of traumatic sacral and pelvic injuries compared with 2D‐CT in all evaluator groups irrespective of experience level reading orthopedic CT studies. However, for radiologists and surgeons, 2D‐CT was the more accurate technique for evaluating sacral and pelvic fractures.

Conclusion

3D‐CT improves sacral and pelvic fracture diagnosis when added to 2D‐CT; however, 3D‐CT has a reduced accuracy for evaluation of sacral and pelvic fractures if used without concurrent evaluation of 2D‐CT images.
The relationship between youth employment and older persons' employment in 20 OECD countries
Authors: JI Eun Jeong
Published: December 2014

Inspired by the “lump of labour” theory, a large number of OECD countries have encouraged the expansion of early retirement policies in response to rising unemployment since the 1970s. In reality, however, youth employment is found to be positively correlated with older persons' employment, although this is simply the overall finding for all OECD countries because most studies estimate average effects. Less is known about diversity in the relationship between youth employment and the employment of older workers. In order to help fill the research gap in this area, this study explores the heterogeneity of that relationship across 20 OECD countries.
Putting Disability Studies to Work in Art Education
Authors: Penketh Claire
Published: December 2014

Putting disability studies to work in art education suggests a form of action or industry, a creative opportunity for something to be done, recognising the relationship between theory and practice. Drawing on discourse analysis, this article offers an initial theoretical discussion of some of the ways in which disability is revealed and created through discourses about art education in articles published over the past 30 years in iJADE. This article proposes that the lens of critical social pedagogies applied to work relating to gender, race and class should be extended to disability in order to promote critical engagement through art education rather than critical avoidance. Drawing on Elliot Eisner's six lessons in what can be learnt from the arts, the article concludes by recognising the importance of art education as a means of epistemic validation, where different ways of being in the world are valued. Art education and arts practice offer a means of valuing and expressing the ‘dynamic difference of what it means to be human’. The article argues that the combination of disability studies and art education can, therefore, be a force to be reckoned with.
Implementation and Assessment of a Fall Screening Program in Primary Care Practices
Authors: Landis Suzanne E. , Galvin Shelley L.
Published: December 2014

Fall prevention strategies for older adults are underused in primary care. A study was designed to examine the Centers for Medicare and Medicaid Services Physician Quality Reporting System (PQRS) fall measures and to reduce injuries and costs from falls by 10%. This quality improvement project using a pre/post design was implemented in four primary care practices with 2,021 patients aged 65 and older in Asheville, North Carolina. The project used a patient registry, electronic templates, standardized care protocols, a falls clinic to evaluate individuals who reported falling, and patient resource materials. Data were collected from medical records on processes of care, fall‐related injuries, and anticipated payments. Individuals billed for at least one outpatient visit from July 2011 through June 2012 (n = 2,021) constituted the cohort for the intervention and for analysis of injuries from falls requiring hospital visits (before the intervention (T1): July 2010 to March 2011; after the intervention (T2): July 2012 to March 2013). Practice sites properly screened 68.8% of older adults for falls, assessed 87% of those who reported falling, and documented the PQRS required plan of care in 23%. Only 20% self‐reported falls. Numbers of falls requiring a visit to the hospital were small overall and did not decrease (T1, 2.4%; T2, 2.9%; P = .32); 61% of individuals seen in the hospital for fall‐related injuries had not reported previous falls. Incorporating the PQRS fall measures into primary care was challenging, and the program was not robust enough to reduce serious falls and hospital costs.
Comparative analysis of undernutrition screening and diagnostic tools as predictors of hospitalisation costs
Authors: Guerra R. S. , Sousa A. S. , Fonseca I. , Pichel F. , Restivo M. T. , Ferreira S. , Amaral T. F.
Published: December 2014

Background

Undernutrition is associated with higher hospitalisation costs. The present study aims (i) to explore whether undernutrition status at hospital admission, as evaluated by different screening and diagnostic tools, can predict patient's hospitalisation costs and (ii) to provide an updated economic analysis of undernutrition burden.

Methods

A prospective study was conducted in a university hospital. Participants’ (n = 637) nutritional risk was evaluated within 72 h of admission using the Nutritional Risk Screening (NRS–2002) and the Malnutrition Universal Screening Tool (‘MUST’). Undernutrition status was determined by Academy of Nutrition and Dietetics (AND) and American Society for Parenteral and Enteral Nutrition (ASPEN) recommended clinical characteristics and by the Patient Generated Subjective Global Assessment (PG–SGA). The hospitalisation cost was calculated for each inpatient using the diagnosis–related group system. Multivariable linear regression analysis was conducted to identify predictors of hospitalisation costs via percentage deviation from the mean cost, after adjustment for patients’ characteristics and comorbidities.

Results

Undernutrition risk according to NRS‐2002 and high undernutrition risk according to ‘MUST’ increased patient's costs, respectively, by 21.1% [95% confidence interval (CI) = 9.0–33.2%] and 28.8% (95% CI = 13.7–39.9%). Severe undernutrition by AND‐ASPEN recommended clinical characteristics and by PG‐SGA was also associated with higher hospitalisation costs, respectively 19.4% (95% CI = 7.3–31.5%) and 27.5% (95% CI = 14.0–41.1%). The cost of a nutritionally‐at‐risk or undernourished patient is between €416 (95% CI = €156–675) and €617 (95% CI = €293–855) higher than the average of the respective diagnosis‐related group.

Conclusions

Undernutrition is a predictor of hospitalisation costs, increasing costs by between 19% and 29%. Undernutrition screening tools have an ability for predicting hospitalisation costs similar to that of diagnostic tools. An updated analysis of undernutrition associated costs was provided, highlighting the economic burden of undernutrition.
Indigenous child health: Are we making progress?
Authors: Brewster David R , Morris Peter S
Published: December 2014

We identified 244 relevant articles pertinent to indigenous health (4% of the total) with a steady increase in number since 1995. Most Australian publications in the journal (with a small Indigenous population) have focussed on conditions such as malnutrition, diarrhoeal disease, iron deficiency, rheumatic fever, acute glomerulonephritis and respiratory and ear infections, and in settings where nearly all affected children are Indigenous. In contrast, New Zealand publications (with a large Maori and Pacific Islander population) have addressed important health issues affecting all children but emphasised the over‐representation of Maori and Pacific Islanders. Publications in the journal are largely descriptive studies with relatively few systematic reviews and randomised trials. Our review attempts to cover the important Indigenous health issues in our region as represented by articles published in the Journal. The studies do document definite improvements in indigenous child health over the last 50 years.
The Short‐Term Effects of C‐Peptide on the Early Diabetes‐Related Ultrastructural Changes to the Podocyte Slit Diaphragm of Glomeruli in Rats
Authors: Nakamoto Hiroshi , Nakayama Kazuhiko , Emoto Noriaki , Kajiya Fumihiko
Published: December 2014

Objective

This study aimed to investigate the structural changes in the slit diaphragm, caused by early diabetes, and the nephroprotective effect of C‐peptide.

Methods

Streptozotocin‐induced type 1 diabetic Wistar rats were divided into control, control plus C‐peptide, early diabetes, and early diabetes plus C‐peptide groups. C‐peptide was infused into rats for one day. The slit diaphragm component proteins podocin, CD2AP, and nephrin, were stained immunofluorescently and their distribution quantitatively analyzed by determining the overlapping area ratio. The interfoot process gap length was measured from electron microscopic images.

Results

Diabetic duration correlated best with the area ratio of podocin and CD2AP (r = 0.626), followed by other protein combinations, showing progressive change in the slit diaphragm structure. C‐peptide‐treatment did not alter area ratios. The interfoot process gap length was wider in diabetic rats (p < 0.05) and did not narrow with C‐peptide‐treatment in either control or diabetic rats (both p < 0.05).

Conclusions

Diabetes widened the interfoot process gap length and distorted the slit diaphragm structure progressively and heterogeneously in rats with early diabetes; this was not altered by C‐peptide‐treatment. The nephroprotective effect of C‐peptide in decreasing the glomerular filtration rate appears to be functional rather than structural.
Just War Reasoning in an Age of Risk
Authors: Reed Esther D.
Published: December 2014

The classic, theological tradition of just war reasoning (JWT) is not exhausted but needed more than ever in the shadow of global risks, when facing “hybrid” war, and when the difference between war and peace is said to be blurring. The tradition does not speak with one voice but debate within the tradition about the (un)acceptability of military action under conditions of uncertainty sheds light, in at least three ways, on ways of approaching the range of unorthodox tactics threated in conflict today:

1.

How to be fearful. Fear and anxiety in an age of risk are potential threats to reason. The JWT has resources with which to consider “how to fear” wisely.

2.

How to grapple with issues of classification, including what constitutes an attack equivalent to an “armed attack” under UN Charter Art 51. When, for instance, are cyber-attacks better dealt with under civilian, international commercial law, and when the laws of war?

3.

How to approach new challenges in a principled manner. Are different principles or criteria needed to govern action (e.g., the criterion of intensity) or do immediacy and necessity remain the most critically important principles in our moral arsenal?
Presence in Mediterranean hotspots and floral symmetry affect speciation and extinction rates in Proteaceae
Authors: Reyes Elisabeth , Morlon Hélène , Sauquet Hervé
Published: December 2014

The Proteaceae is a large angiosperm family displaying the common pattern of uneven distribution of species among genera. Previous studies have shown that this disparity is a result of variation in diversification rates across lineages, but the reasons for this variation are still unclear. Here, we tested the impact of floral symmetry and occurrence in Mediterranean climate regions on speciation and extinction rates in the Proteaceae.

A rate shift analysis was conducted on dated genus‐level phylogenetic trees of the Proteaceae. Character‐dependent analyses were used to test for differences in diversification rates between actinomorphic and zygomorphic lineages and between lineages located within or outside Mediterranean climate regions.

The rate shift analysis identified 5–10 major diversification rate shifts in the Proteaceae tree. The character‐dependent analyses showed that speciation rates, extinction rates and net diversification rates of the Proteaceae were significantly higher for lineages occurring in Mediterranean hotspots. Higher speciation and extinction rates were also detected for zygomorphic species, but net diversification rates appeared to be similar in actinomorphic and zygomorphic Proteaceae.

Presence in Mediterranean hotspots favors Proteaceae diversification. In contrast with observations at the scale of angiosperms, floral symmetry is not a trait that strongly influences their evolutionary success.
The Effects of Multitasking on Operations Scheduling
Authors: Hall Nicholas G. , Leung Joseph Y.‐T. , Li Chung‐Lun
Published: December 2014

This study considers a typical scheduling environment that is influenced by the behavioral phenomenon of multitasking. Under multitasking, the processing of a selected job suffers from interruption by other jobs that are available but unfinished. This situation arises in a wide variety of applications; for example, administration, manufacturing, and process and project management. Several classical solution methods for scheduling problems no longer apply in the presence of multitasking. The solvability of any scheduling problem under multitasking is no easier than that of the corresponding classical problem. We develop optimal algorithms for some fundamental and practical single machine scheduling problems with multitasking. For other problems, we show that they are computationally intractable, even though in some cases the corresponding problem in classical scheduling is efficiently solvable. We also study the cost increase and value gained due to multitasking. This analysis informs companies about how much it would be worthwhile to invest in measures to reduce or encourage multitasking.
Cold acclimation induces distinctive changes in the chromatin state and transcript levels of COR genes in Cannabis sativa varieties with contrasting cold acclimation capacities
Authors: Mayer Boris F. , Ali‐Benali Mohamed Ali , Demone Jordan , Bertrand Annick , Charron Jean‐Benoit
Published: December 2014

Little is known about the capacity of Cannabis sativa to cold‐acclimate and develop freezing tolerance. This study investigates the cold acclimation (CA) capacity of nine C. sativa varieties and the underlying genetic and epigenetic responses. The varieties were divided into three groups based on their contrasting CA capacities by comparing the survival of non‐acclimated and cold‐acclimated plants in whole‐plant freeze tests. In response to the CA treatment, all varieties accumulated soluble sugars but only the varieties with superior capacity for CA could maintain higher levels throughout the treatment. In addition, the varieties that acclimated most efficiently accumulated higher transcript levels of cold‐regulated (COR) genes and genes involved in de novo DNA methylation while displaying locus‐ and variety‐specific changes in the levels of H3K9ac, H3K27me3 and methylcytosine (MeC) during CA. Furthermore, these hardy C. sativa varieties displayed significant increases in MeC levels at COR gene loci when deacclimated, suggesting a role for locus‐specific DNA methylation in deacclimation. This study uncovers the molecular mechanisms underlying CA in C. sativa and reveals higher levels of complexity regarding how genetic, epigenetic and environmental factors intertwine.
Measuring the Growth of the Nonprofit Sector: A Longitudinal Analysis
Authors: Kim Seok Eun , Kim You Hyun
Published: December 2014

Scholars have examined the effects of various environmental factors on the nonprofit sector to elucidate the role of nonprofits in modern society. However, researchers report a paucity of information on nonprofit growth using longitudinal data, especially outside the United States. This article analyzes 40 years of political, economic, and sociodemographic data in South Korea to test theories of nonprofit growth and to determine whether the concepts and theories developed for Western societies can be successfully applied in South Korea. The results show that demand‐ and supply‐side economic theories account for variations in nonprofit growth, but the existing socioeconomic explanations fail to recognize the political influences on nonprofit development. Nonprofit organizations have emerged from social and economic necessity but have also been nurtured within a political framework.
Grounding mobile policies: Ad hoc networks and the creative city in Bandung, Indonesia
Authors: Cohen Dan
Published: December 2014

This paper explores the ad hoc networks that form to move policies to new sites by examining the process through which the city of Bandung, Indonesia adopted a creative city policy. As revealed through the Bandung case, attention to the formation of these networks highlights the way that power operates within them, privileging certain ideas and structuring the ways in which information flows through their channels. This insight suggests that the concept of policy mobilities would be enriched by a closer attention to the way power is used to construct networks that promote specific policies and places as sites of ‘best practice’. Furthermore, this paper extends the concept of policy mobilities to a city ‘off the map’. In contrast to most existing policy mobilities research that tends to focus on the stable, large‐scale networks through which policies travel and on the high‐profile cities constructed as policy models, the case of Bandung provides a study of how policy mobilities may occur differently outside of its well‐established locations.
Clearing of psoriasis documented by laser Doppler perfusion imaging contrasts remaining elevation of dermal expression levels of CD31
Authors: Hendriks A. G. M. , van de Kerkhof P. C. M. , de Jonge C. S. , Lucas M. , Steenbergen W. , Seyger M. M. B.
Published: December 2014

Background

Vascular modifications represent a key feature in psoriatic plaques. Previous research with Laser Doppler Perfusion Imaging (LDPI) revealed a remarkable heterogeneity in the cutaneous perfusion within homogenous‐appearing psoriatic lesions. Insights in the relation between perfusion during treatment and related biological changes are lacking.

Objectives

To study the effect of calcipotriol‐betamethasone dipropionate ointment on the microcirculation and the expression levels of immunohistochemical markers in psoriatic lesions compared to the distant uninvolved skin.

Methods

Psoriatic lesions of fourteen patients were treated once a day during 8 weeks. Clinical SUM scores and the perfusion intensity by means of LDPI were assessed every 2 weeks. After 8 weeks, a biopsy from the target lesion and one from the distant uninvolved skin were taken and stained for psoriasis‐related markers, like IL‐17 and CD31.

Results

After 8 weeks, seven patients reached a SUM score of 0 or 1, and were classified as good‐responders. The other patients were classified moderate‐responders. The perfusion intensity decreased in all lesions during therapy. In the good‐responders, all investigated psoriasis‐related proteins within the treated lesions reached the expression level found within the distant uninvolved skin. The expression of CD31, however, was significantly higher in the treated lesions as compared to the distant uninvolved skin (p = 0.0156). In the moderate responders, almost all expression levels remained significantly elevated compared to the uninvolved skin.

Conclusions

In the skin of good‐responders the expression of dermal CD31+ endothelium remains significantly elevated within the treated lesions compared with the distant uninvolved skin, whereas a marked reduction in the perfusion intensity and SUM score was found. This indicates that clinical improvement might outrun endothelial changes.
Imbalance Response of a Rotor Supported on Open-Ends Integral Squeeze Film Dampers
Authors: de Santiago Oscar , San Andrés Luis , Oliveras Juan
Published: December 2014

Rotor vibration attenuation and structural components isolation in jet engines are achieved with squeeze film dampers, many of them supported on long elastic squirrel cages. Integral squeeze film dampers (ISFDs) are comprised of arcuate pads and wire-EDM webs rendering a compact viscoelastic support. An experimental study is conducted to evaluate the effectiveness of ISFDs in attenuating the imbalance response of a massive test rotor. Measurements of the damper structural stiffness and rotor natural frequencies are detailed. Impact tests on the test rotor supported on its dampers reveal the supporting structure to be very flexible, thus requiring the experimental evaluation of an equivalent stiffness for the damper and supports system. System damping coefficients extracted from impact load excitations vary with the lubricant viscosity and include a significant structural damping from the bearing supports. Rotor coast-down tests demonstrate the ISFDs to damp well the rotor response with peak vibration amplitude proportional (linear) to the imbalance. Viscous damping coefficients estimated from the amplitude response at the critical speeds agree reasonably well with predictions from a full-film, finite element model.
Final Report on the Development of a Hydrogen-Fueled Combustion Turbine Cycle for Power Generation
Authors: Bannister Ronald L. , Newby Richard A. , Yang Wen-Ching
Published: December 2014

Through its New Energy and Industrial Technology Development Organization (NEDO) the Japanese government is sponsoring the World Energy Network (WE-NET) Program. WE-NET is a 28-year global effort to define and implement technologies needed for hydrogen-based energy systems. A critical part of this effort is the development of a hydrogen-fueled combustion turbine system to efficiently convert the chemical energy stored in hydrogen to electricity when hydrogen is combusted with pure oxygen.

A Rankine cycle, with reheat and recuperation, was selected by Westinghouse as the general Reference System. Variations of this cycle have been examined to identify a Reference System having maximum development feasibility, while meeting the requirement of a minimum of 70.9% low heating value (LHV) efficiency. The strategy applied by Westinghouse was to assess both a near-term and long-term Reference Plant. The near-term plant requires moderate development based on extrapolation of current steam and combustion turbine technology. In contrast, the long-term plant requires more extensive development for an additional high-pressure reheat turbine, and is more complex than the near-term plant with closed-loop steam cooling and extractive feedwater heating. Trade-offs between efficiency benefits and development challenges of the near-term and long-term reference plant are identified. Results of this study can be applied to guide the future development activities of hydrogen-fueled combustion turbine systems.
The Advanced Turbogenerator Project — A Total Technology Education Experience for Engineering Undergraduate Students
Authors: Pullen K. R. , Court A. W. , Besant C. B.
Published: December 2014

The preparation of engineering students for industrial careers after graduating is a vital part of the education process at university. It is the responsibility of the university to teach sound foundations of engineering science but this on its own is not sufficient preparation. The subject of design has been identified as a valuable means by which engineering science can be applied at advanced levels but at the same time teach students skills which are necessary for successful careers in industry.

Three years ago, five senior engineers from UK industry were appointed as Visiting Professors in Engineering Design with the support of the Royal Academy of Engineering. In was decided after discussions with academics at the college to undertake a project entitled the Advanced Turbogenerator project (ATG). The project was to be conducted by a large team of undergraduates with the aim of producing a design and finally an actual small gas turbine of 50 kW output. Applications for the small gas turbine include the highly topical hybrid vehicle propulsion powertrain and compact low emissions generator sets.

The paper describes the progress made in the project in two years which has involved over 30 final year engineering students in the Mechanical, Electrical, Aeronautical and Materials Science Departments. The students have found the project very challenging but have experienced an unusually high level of motivation and commitment to the work. They have been provided with state of the art software and have demonstrated that realistic designs can be produced with the guidance of experienced gas turbine engineers. The project has been reviewed by the Royal Academy of Engineering and the Institution of Mechanical Engineers and both have expressed the highest support for the programme. It is intended to continue the project next year with the intention of turning the design into prototype hardware.
Representing Flexible Supports by Polynomial Transfer Functions
Authors: Vázquez José A. , Barrett Lloyd E.
Published: December 2014

Flexible bearing supports may have a great influence in the calculation of forced response and stability of rotor systems. However, this effect is not always included in rotor analyses since an accurate model of the foundation and pedestals may be difficult and costly to obtain. It is common practice to use either a one degree of freedom model or a full modal analysis to represent the bearing supports. While the one degree of freedom model is easy to set up for computer calculations, it often requires experience to determine values for the stiffness, mass and damping of the model that will accurately represent the support under study. This model, however, fails to capture the dynamics of the system for stability analyses when more than one mode of the support structure is in the range of interest. On the other hand, modal representation provides much more information and can be measured experimentally, but requires measurement of the mode shapes. Even though modal representation can include all the dynamics of the system in the frequency range of interest, it provides much more information than is required for calculation of the rotor response and it is more difficult to use in calculation programs. This paper presents a procedure to include the support characteristics using transfer functions. Transfer functions permit modeling of multi-degree of freedom systems while maintaining the size of a one degree of freedom system (2×2 matrix if rotation at the bearing is not considered). Another advantage of transfer functions is that they can be obtained from existing discrete models, from modal information or can be measured directly. The fixed size of the transfer function matrix permits the method to be easily incorporated into rotor dynamic stability and forced response programs. The method is applied to stability calculations of models of typical industrial machines.
The Effect of Tip Clearance Gap Size and Wall Rotation on the Performance of a High-Speed Annular Compressor Cascade
Authors: Doukelis A. , Mathioudakis K. , Papailiou K.
Published: December 2014

The performance of a high speed annular compressor cascade for different clearance gap sizes, with stationary or rotating hub wall is investigated. Five hole probe measurements, conducted at the inlet and outlet of the cascade, are used to derive blade performance characteristics, in the form of loss and turning distributions. Characteristics are presented in the form of circumferentially mass averaged profiles, while distributions on the exit plane provide information useful to interpret the performance of the blading. Static pressure distributions on the surface of the blades as well as inside the tip clearance gap have also been measured. A set of four clearance gap sizes, in addition to zero clearance data for the stationary wall, gives the possibility to observe the dependence of performance characteristics on clearance size, and establish the influence of rotating the hub. Overall performance is related to features of the tip clearance flow. Increasing the clearance size is found to increase losses in the clearance region, while it affects the flow in the entire passage. Wall rotation is found to improve the performance of the cascade.
Extending Use of Marine Gas Turbines Through Application of the LM2500+
Authors: Luck David L.
Published: December 2014

The propulsion configurations of current gas turbine powered military and commercial vessels have been established based upon available power ratings of existing engines, relative to the performance requirements of ship builders and operators. Development of the LM2500+ engine has extended power capability with minimal changes to the physical parameters of the current LM2500 marine packages. This paper explores the extended possibilities of gas turbine based propulsion in both military and commercial vessels through application of increased gas turbine power in packages of essentially current size and weight such as the LM2500+.
A Comparison of the Streamline Throughflow and Streamline Curvature Methods for Axial Turbomachinery
Authors: Gannon Anthony J. , von Backström Theodor W.
Published: December 2014

The axial flow turbo machinery throughflow equation states that radial gradients of rothalpy, entropy and moment of momentum affect the conservation of tangential vorticity. The streamline throughflow method (STFM) transforms this equation, expressed in terms of stream function in a radial-axial co-ordinate system, to an equation for streamline radial position in a stream function-axial co-ordinate system. The paper assesses the accuracy and efficiency of the STFM relative to the streamline curvature method (SCM) by comparing streamline positions and velocity profiles to analytical results. Test cases include flow through a single actuator disc, flow through twin actuator discs using a coarse computational grid, compressible flows through an almost choked nozzle, through single and twin actuator discs, and swirling flow using sloped stations. Results from the STFM and SCM agreed about equally well with analytical solutions for the same number of streamlines. The STFM, however, was much more tolerant of distorted computational grids and used an order of magnitude less computer time to converge. The test cases show that the STFM is suitable for annuli with large variations in hub and tip radius, for highly swirling and compressible flow, and is more robust and converges faster than the SCM. To demonstrate the practical applicability of the STFM a multistage compressor was simulated and STFM results compared with experiment.
Multistage Centrifugal Compressor Fouling Evaluation at High Power Settings
Authors: Haq Inam U. , Bu-Hazza Ahmed I. , Al-Baz Khalid
Published: December 2014

This paper investigates the effects of multistage centrifugal compressor fouling on the performance of machine and plant operation. A thermodynamic model for the compressor has been developed for studying in-situ compressor performance deterioration due to internal component fouling at high power settings. The four casings, six sections compressor train is one of the critical process loop components in meeting ethylene production targets in a large scale petrochemical complex. The compressor handles process gas which is a complex mixtures of cracked gases (17 constituents) containing measurable concentrations of high molecular weight hydrocarbons. The model requires minimum inputs (pressure, temperature, flow, speed) from readily available instrument sensors and derives all the necessary information that predicts overall performance. Various parameters characterizing multistage compressor health condition were investigated. The study revealed that fouling of early stages adversely affect the polytropic efficiency of later stages. The model is cost effective in operation and is fully capable of detecting small changes occurring periodically in the compressor. A simple predictive monitoring scheme was developed for assessing the degree of compressor fouling that will strongly help engineers responsible for decision making.
Flow Measurements in Film Cooling Flows With Lateral Injection
Authors: Kaszeta Richard W. , Simon Terrence W. , Oke Rohit A. , Burd Steven W.
Published: December 2014

Measurements of mean velocity and turbulence intensity are presented for the mixing region of a film cooling situation in which the coolant is laterally injected. Measurements are performed using triple-sensor anemometry so that all three velocity components are documented. Flow with one row of film cooling holes inclined 35° to the surface, with lateral injection (Φ = 90°), is documented. The freestream turbulence intensity level is 12%, and coolant-to-mainstream velocity ratios are 0.5 and 1.0 (the density ratio is unity). General flow field characteristics ore discussed and compared. Additional comparisons are made with similar measurements in a flow in which the injection is streamwise (Φ = 0°).
Measurement and Calculation of Nozzle Guide Vane End Wall Heat Transfer
Authors: Harvey Neil W. , Rose Martin G. , Coupland John , Jones Terry
Published: December 2014

A 3-D steady viscous finite volume pressure correction method for the solution of the Reynolds averaged Navier-Stokes equations has been used to calculate the heat transfer rates on the end walls of a modern High Pressure Turbine first stage stator.

Surface heat transfer rates have been calculated at three conditions and compared with measurements made on a model of the vane tested in annular cascade in the Isentropic Light Piston Facility at DERA, Pyestock. The NGV Mach numbers, Reynolds numbers and geometry are fully representative of engine conditions. Design condition data has previously been presented by Harvey and Jones (1990). Off-design data is presented here for the first time.

In the areas of highest heat transfer the calculated heat transfer rates are shown to be within 20% of the measured values at all three conditions. Particular emphasis is placed on the use of wall functions in the calculations with which relatively coarse grids (of around 140,000 nodes) can be used to keep computational run times sufficiently low for engine design purposes.
Prediction and Measurement of Rotating Stall Cells in an Axial Compressor
Authors: Saxer-Felici H. M. , Saxer A. P. , Inderbitzin A. , Gyarmathy G.
Published: December 2014

This paper presents a parallel numerical and experimental study of rotating stall cells in an axial compressor. Based on previous theoretical and experimental studies stressing the importance of fluid inertia and momentum exchange mechanisms in rotating stall, a numerical simulation using the Euler equations is conducted. Unsteady 2-D solutions of rotating stall behavior are obtained in a one-stage low subsonic axial compressor. The structure and speed of propagation of one fully developed rotating stall cell together with its associated unsteady static pressure and throughflow field distributions are presented. The numerical capture of a stalled flow region starting from a stable high-flow operating point with an axisymmetric flow distribution and evolving at a reduced mass flow operating point into a rotating stall pattern is also discussed.

The experimental data (flow visualization, time-averaged and unsteady row-by-row static pressure measurements) acquired in a four-stage water model of a subsonic axial compressor covers a complete characteristic line ranging from high mass flow in the stable regime to zero throughflow. Stall inception is presented together with clearly marked different operating zones within the unstable regime.

For one operating point in the unstable regime, the speed of propagation of the cell as well as the static pressure spikes at the front and rear boundaries of the rotating stall cell are compared between computations, measurements and an idealized theory based on momentum exchange between blade rows entering and leaving the stalled cell. In addition, the time-evolution of the pressure trace at the rotor/stator interface is presented.

This study seems to support the assumption that the cell structure and general mechanism of full-span rotating stall propagation are essentially governed by inertial effects and momentum exchange between the sound and stalled flow at the cell edges.
Uncertainty in Gas Turbine NOx Emission Measurements
Authors: Hung Wilfred S. Y. , Campbell Alan
Published: December 2014

The advent of dry, low-emissions combustion systems for gas turbine applications and the trend towards requiring emissions monitoring and lower NOx limits by regulatory agencies, have created renewed interests in the uncertainty of NOx emissions measurements. This paper addresses the uncertainty of measuring NOx emissions from gas turbines in the field, including gas turbines equipped with conventional combustion systems, with or without water injection, with dry, low-emissions combustion systems and with exhaust clean-up systems.

The sources of errors, using current state-of-the-art instruments, in field emissions testing or continuous emission monitoring of gas turbines to meet specific emission (ppmvd @ 15% O2) as well as mass emission rate (kg/hr) limits are identified. The uncertainty of measuring NOx emissions from gas turbines is estimated and compared with Geld data. The effect of NOx emission levels on measurement uncertainty is also addressed. The minimus NOx measurement uncertainty is determined and is in good agreement with what is currently allowed by regulatory agencies.