bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinants of Adequate Emergency Funds Including the Effects of Seeking Professional Advice and Industry Affiliation
Authors: Anong Sophia T. , DeVaney Sharon A.
Published: May 2010

This research examined the effects of seeking professional financial advice and being employed in different industries on a household’s likelihood of holding adequate emergency funds to cover six or more months without income. The theory of precautionary savings provided a conceptual framework for the study. Three measures of emergency funds were analyzed: Subjective funds, Quick funds, and Comprehensive funds. The sample consisted of working household heads in the 2007 Survey of Consumer Finances. Seeking professional financial advice significantly increased the likelihood of holding adequate Comprehensive funds. Only household heads employed in financial, insurance, real estate, repair, and advertising industries were more likely to have adequate levels of Subjective and Comprehensive funds. Household heads employed in manufacturing, construction, and retail industries, which are more likely to be affected by a recession, did not have increased likelihood of holding adequate emergency funds. Financial educators and advisors need to stress the importance of adequate emergency savings.
Are Consumers Vulnerable to Low Knowledge of Long‐Term Care?
Authors: Matzek Amanda E. , Stum Marlene S.
Published: May 2010

This study contributes empirical evidence about who is most vulnerable to low knowledge of long‐term care (LTC). A random sample of public employees (n = 760) in Minnesota facing decisions about managing the risk of LTC was utilized to examine levels of LTC financial knowledge using written survey methods. Employees scored an average of 69% correct (9 of 13 items) on the true/false quiz designed to measure LTC financial knowledge. Average scores indicated employees were most knowledgeable about concepts related to risk followed by financing alternatives, and least knowledgeable about costs. Multiple regression analyses indicated that employees who had lower incomes, were married, and without living children were more vulnerable to lower overall knowledge. Individual characteristics were significant when examining differences in knowledge about LTC with regard to risk, costs, and financing alternatives. This study has implications for policymakers and practitioners being asked to identify and implement appropriate strategies to improve LTC financial literacy.
Improved survival of multiple myeloma patients with late relapse after high‐dose treatment and stem cell support, a population‐based study of 348 patients in Denmark in 1994–2004*
Authors: Vangsted Annette J. , Klausen Tobias W. , Andersen Niels F. , Abildgaard Niels , Gang Anne O. , Gregersen Henrik , Vogel Ulla , Gimsing Peter
Published: May 2010

Objective:  To analyse if patients with early relapse after high‐dose chemotherapy with stem cell support (HDT) benefit from new treatment strategies in a population‐based setting.

Methods:  We conducted a retrospective study of relapse treatment and survival in 348 patients undergoing HDT in Denmark in 1994–2004. Patients were divided into two groups according to time‐to‐treatment failure (i) within 18 months after HDT and (ii) later than 18 months after HDT. The fraction of patients surviving 3 yr after first relapse was evaluated in relation to calendar periods for introduction of new drugs: before the introduction of thalidomide (1995–1999), before the introduction of bortezomib and lenalidomide (2000–2002) and when patients had access to all treatment modalities (2003–2008).

Results:  Two hundred and forty‐three patients suffered from relapse which required treatment. The median follow‐up time was 91.4 months (60–158.8 months) and overall survival was 56.3 months after HDT. The fraction of patients alive 3 yr after first relapse increased in the periods after the year 2000 for patients with late relapse: 1995–1999, 36%; 2000–2002, 57%; and 2003–2008, 72% (P = 0.03), in contrast to patients with early relapse: 1995–1999, 25%; 2000–2002, 33%; and 2003–2008, 31% (P = 0.7).

Conclusion:  Improved survival was only observed among patients with late relapse after HDT and this may be because of increased use of salvage HDT, improved supportive care and introduction of new drugs.
Ki‐67 expression as a prognostic factor in diffuse large B‐cell lymphoma patients treated with rituximab plus CHOP
Authors: Yoon Dok Hyun , Choi Dae Ro , Ahn Heui June , Kim Shin , Lee Dae Ho , Kim Sang‐We , Park Bong‐Hee , Yoon Sun Och , Huh Jooryung , Lee Sang‐Wook , Suh Cheolwon
Published: May 2010

Background:  Assessment of tumor cell proliferation based on Ki‐67 expression yielded conflicting prognostic predictions of patients with diffuse large B‐cell lymphoma (DLBCL). The introduction of rituximab to the DLBCL treatment regime has led to alterations in the significance of previous prognostic factors.

Methods:  We analyzed Ki‐67 expression and its correlation with prognosis in 144 patients with DLBCL treated with rituximab plus CHOP (R‐CHOP) between July 2003 and January 2008.

Results:  The complete response (CR) rates following R‐CHOP administration were not significantly different, based on Ki‐67 expression status (P = 0.104). However, higher rates of relapse were observed in the high Ki‐67 expression group (Ki‐67 ≥ 85%, n = 46) with 25.0%, compared to 10.0% in the low Ki‐67 expression group (Ki‐67 < 85%, n = 88) (P = 0.040). The 2‐yr event‐free survival (EFS) rates were 44.3% and 74.1% in the high and low Ki‐67 expression groups, respectively (P = 0.011). The 2‐yr overall survival (OS) rate was 66.4% in the high Ki‐67 expression group and 82.2% in the low Ki‐67 expression group (P = 0.016). In multivariate analysis, Ki‐67 expression was a significant prognostic factor for EFS [hazard ratio (HR) = 2.909; 95% confidence interval (CI) 1.261–6.708; P = 0.012]. Ki‐67 was associated with OS but with borderline significance (HR = 2.876; 95% CI, 0.972–8.508; P = 0.056).

Conclusion:  Elevated Ki‐67 expression seems to be associated with higher relapse after CR and inferior EFS in patients with DLBCL treated with R‐CHOP.
Metabolic Syndrome Increases Carotid Artery Stiffness: the Northern Manhattan Study
Authors: Della-Morte David , Gardener Hannah , Denaro Federica , Boden-Albala Bernadette , Elkind Mitchell S. V. , Paik Myunghee C. , Sacco Ralph L. , Rundek Tatjana
Published: May 2010

Background

Arterial stiffness, an intermediate pre-clinical marker of atherosclerosis, has been associated with an increased risk of stroke and cardiovascular disease. The metabolic syndrome and its components are established cardiovascular disease risk factors and may also increase arterial stiffness; however, data regarding this are limited.

Aim

The goal of this study was to determine the association between the metabolic syndrome and carotid artery stiffness in an elderly multi-ethnic cohort.

Methods

Carotid artery stiffness was assessed by carotid ultrasound as part of the Northern Manhattan Study, a prospective population-based cohort of stroke-free individuals. Carotid artery stiffness was calculated as [In (systolic BP/diastolic BP)/strain], where strain was [(systolic diameter diastolic diameter)/diastolic diameter]. Metabolic syndrome was defined by the National Cholesterol Education Program: Adult Treatment Panel III criteria. LogSTIFF was analysed as the dependent variable in linear regression models, adjusting for demographics, education, current smoking, presence of carotid plaque and intima-media thickness.

Results

Carotid artery stiffness was analysed in 1133 Northern Manhattan Study subjects (mean age 65 ± 9 years; 61% women; 58% Hispanic, 22% Black and 20% Caucasian). The prevalence of the metabolic syndrome was 49%. The mean LogSTIFF was 2·01±0·61 among those with the metabolic syndrome and 1·90 ± 0·59 among those without the metabolic syndrome ( P = 0·003). The metabolic syndrome was significantly associated with increased logSTIFF in the final adjusted model (parameter estimate β = 0·100, P = 0·01). Among individual metabolic syndrome components, waist circumference and elevated blood pressure were most significantly associated with a mean increase in logSTIFF ( P < 0·01).

Conclusion

The metabolic syndrome is significantly associated with increased carotid artery stiffness in a multiethnic population. Increased carotid artery stiffness may, in part, explain a high risk of stroke among individuals with the metabolic syndrome.
The Difference between Acute Coronary Heart Disease and Ischaemic Stroke Risk with Regard to Gender and Age in Finnish and Swedish Populations
Authors: Hyvärinen Marjukka , Qiao Qing , Tuomilehto Jaakko , Söderberg Stefan , Eliasson Mats , Stehouwer Coen D. A.
Published: May 2010

Background

We studied the age and gender difference between acute coronary heart disease and ischaemic stroke risk and examined the extent to which such a difference may be explained by known risk factors.

Methods

Data from Finnish and Swedish population-based cohorts including 9278 individuals were collaboratively analysed. Hazards ratios (95% confidence intervals) for coronary heart disease and stroke incidence were estimated using the Cox-proportional hazards model.

Results

The incidence of coronary heart disease and stroke was higher in all age groups in men than in women, and the gender difference was more marked for coronary heart disease than for ischaemic stroke. There was a 10-year lag in the development of coronary heart disease and stroke in women compared with men. The multivariable adjusted hazard ratios for the incidence of coronary heart disease in men and women were 3·87 (2·49–6·02) and 1·71 (1·07–2·74) at age 50–59 years, and 7·22 (4·59–11·36) and 3·49 (2·18–5·57) at age 60–69 years compared with women aged 40–49 years. For ischaemic stroke, they were 2·64 (1·45–4·82) and 2·17 (1·18–3·97) at age 50–59 years, and 5·19 (2·81–9·58) and 4·89 (2·67–8·97) at age 60–69 years, respectively.

Conclusions

Acute coronary heart disease and ischaemic stroke events appeared approximately 10 years earlier in men than in women, and these rates remained higher in men than in women in all age groups. The gender difference was more marked for coronary heart disease than for ischaemic stroke. This may be taken into account when developing interventions and treatment strategies.
Lack of Association between Hyperglycaemia at Arrival and Clinical Outcomes in Acute Stroke Patients Treated with Tissue Plasminogen Activator
Authors: Meurer William J. , Scott Phillip A. , Caveney Angela F. , Majersik Jennifer J. , Frederiksen Shirley M. , Sandretto Annette , Holden Ann B. , Silbergleit Robert
Published: May 2010

Rationale

Hyperglycaemia is associated with adverse outcomes in some studies of acute ischaemic stroke.

Aims

We hypothesised that in thrombolytic-treated stroke patients, hyperglycaemia would be independently associated with haemorrhagic transformation and unfavourable outcome.

Design

Consecutive rt-PA-treated acute ischaemic stroke patients presenting to four emergency departments were analysed. Associations of initial blood glucose and survival to hospital discharge, symptomatic intracerebral haemorrhage, any form of intracerebral haemorrhage, and disability at hospital discharge were determined. Potentially confounding factors of age, National Institutes of Health Stroke Scale, and smoking were analysed by univariate logistic regression and those with P<0·3 included in the multivariate model.

Study Outcome

In 268 patients, initial glucose values ranged from 62 to 507mg/dl (mean 131). Elevated glucose at arrival was not significantly associated with any adverse clinical outcomes. A trend towards higher mortality in hyperglycae-mic patients (odds ratio 1·71 per 100mg/dl increase in glucose, 95% confidence interval 0·92–3·13, P = 0·08) was seen, but is of unclear significance, and was not corroborated by effects on discharge disability, symptomatic intracerebral haemorrhage or intracerebral haemorrhage.

Conclusions

Thrombolytic-treated stroke patients with hyperglycaemia at presentation did not have significantly worse outcomes than others in this cohort. These data fail to confirm previously described associations seen in similarly sized studies. Further study of these associations and their magnitude are necessary to better define the relationship between serum glucose and outcome in thrombolytic-treated acute ischaemic stroke.
Intensive Care Management of Acute Stroke: Surgical Treatment
Authors: Sykora Marek , Diedler Jennifer , Jüttler Eric , Steiner Thorsten , Zweckberger Klaus , Hacke Werner , Unterberg Andreas
Published: May 2010

Controversy still exists on surgical management of acute stroke. Even if surgical therapy represents often a life-saving measure, the issue of acceptable outcome remains open. Persuasive evidence for outcome benefit is limited. For large ischaemic strokes, recent convincing data suggest that decompressive surgery significantly reduces mortality and improves outcome quality. On the other hand, despite the long tradition in surgical removal of intracranial haematomas, the recent evidence has not been sufficient to resolve the basic argument whether to operate or not. Most recently, hopeful preliminary data have emerged on new approaches in the treatment of intraventricular haemorrhage. In this article, we review the current neurosurgical options in acute ischaemic and haemorrhagic stroke.
Rehabilitation for Community-Dwelling People with Stroke: Home or Centre Based? a Systematic Review
Authors: Hillier Susan , Inglis-Jassiem Gakeemah
Published: May 2010

Stroke rehabilitation for people living in the community is commonly delivered either in a centre, outpatient or day hospital setting. More recently, services may be offered in the actual home of the person as home-based or domiciliary rehabilitation. There are differing reports of the benefits and barriers of home-based vs. centre-based community rehabilitation. This systematic review sought to pool data from all retrieved studies that compared the functional benefits of home-based vs. centre for community-dwelling people with stroke. A comprehensive search strategy was implemented in all major databases (Cochrane library, Medline, AMED, Embase, Ageline, Cinahl, PEDro) for randomised controlled trials investigating this question in relation to functional benefits as a primary outcome and carer, cost or other benefits as secondary outcomes. There were no language or date limits. Eleven trials were found and results pooled for the Barthel Index, the measure of functional independence used consistently across the majority of retrieved studies. There was a significant effect in favour of home-based rehabilitation at 6 weeks ( P = 0·03) and 3–6 months ( P = 0·01). The effects were less clear at 6 months, although this was using the less sensitive version of the Barthel Index ( P = 0·27 or adjusted P = 0·04). Individual studies reported cost benefits and increased carer satisfaction in favour of home-based rehabilitation. The provision of rehabilitation for people living in the community should trend towards home-based. Further research is required into adverse events and the experiences of all stakeholders.
Management of Cholesterol to Reduce the Burden of Stroke in Asia: Consensus Statement
Authors: Hankey Graeme J. , Wong Ka S. L. , Chankrachang Siwaporn , Chen Christopher , Crimmins Denis , Frayne Judith , Kim Jong S. , Li Yansheng , Liou Chia-Wei , Merican Julia S. , Misbach Jusuf , Navarro Jose , Shinohara Yukito , Wang Yongjun , Yoon Byung-Woo
Published: May 2010

Stroke is a major cause of morbidity and mortality in Asia, and its pattern is changing. The incidence of haemorrhagic stroke is declining while the incidence of ischaemic stroke caused by large artery atherothromboembolism is increasing secondary to an increase in the prevalence of hypercholesterolemia. The Working Group on Stroke and Lipids Management in Asia Consensus Panel assembled leading experts from the region to reach a consensus on how to address this challenge. The group discussed the observational epidemiology of the relationship between cholesterol and risk of stroke, the clinical trial evidence base for cholesterol-lowering for stroke prevention, and issues specific to stroke and lipid management for Asian doctors and patients. Stroke guidelines from many of the Asian countries have recently recommended consideration of statins for recurrent stroke prevention in patients with previous ischaemic stroke or transient ischaemic attack. However, because these recommendations have yet to be
The Intracerebral Haemorrhage Acutely Decreasing Arterial Pressure Trial: ICH ADAPT
Authors: Butcher Kenneth , Jeerakathil Thomas , Emery Derek , Dowlatshahi Dar , Hill Michael D. , Sharma Mukul , Buck Brian , Findlay Max , Lee Ting Y. , Demchuk Andrew M.
Published: May 2010

The majority of intracerebral haemorrhage patients present with markedly elevated blood pressure immediately after symptom onset. Management of blood pressure in the first 24 h is extremely controversial and lends itself to two competing rationales. There is some evidence that early treatment may improve outcome, potentially by reducing the rate of haematoma expansion. It is also possible that this will reduce cerebral blood flow and therefore exacerbate the cerebral injury, particularly in the region surrounding the haematoma. Only a trial that includes both randomisation of patients to two different blood pressure management strategies and actual measurement of cerebral blood flow can effectively address this pressing debate. This is the only unequivocal way to demonstrate the haemodynamic effects of rapid blood pressure reduction. The Intracerebral Haemorrhage Acutely Decreasing Arterial Pressure Trial is designed to test the hypothesis that blood pressure reduction does not result in significant or harmful changes in cerebral blood flow in acute intracerebral haemorrhage. Two hours after randomisation to a systolic blood pressure target of <150 or <180 mmHg, cerebral blood flow is measured using computed tomography perfusion, which is the primary end-point of the trial. A study of this type is critical to establishing the safety of early blood pressure treatment and is necessary for planning larger efficacy trials in a rational manner. This trial is registered with clinicaltrials.gov (NCT00963976).
Parts and Wholes
Authors: McDaniel Kris
Published: May 2010

Philosophical questions concerning parts and wholes have received a tremendous amount of the attention of contemporary analytic metaphysicians. In what follows, I discuss some of the central questions. The questions to be discussed are: how general is parthood? Are there different kinds of parthood or ways to be a part? Can two things be composed of the same parts? When does composition occur? Can material objects gain or lose parts? What is the logical form of the parthood relation enjoyed by material objects?
What is Constructivism in Ethics and Metaethics?
Authors: Street Sharon
Published: May 2010

Most agree that when it comes to so‐called ‘first‐order’ normative ethics and political philosophy, constructivist views are a powerful family of positions. When it comes to metaethics, however, there is serious disagreement about what, if anything, constructivism has to contribute. In this paper I argue that constructivist views in ethics include not just a family of substantive normative positions, but also a distinct and highly attractive metaethical view. I argue that the widely accepted ‘proceduralist characterization’ of constructivism in ethics is inadequate, and I propose what I call the ‘practical standpoint characterization’ in its place. I then offer a general taxonomy of constructivist positions in ethics. Since constructivism’s standing as a family of substantive normative positions is relatively uncontested, I devote the remainder of the paper to addressing skeptics’ worries about the distinctiveness of constructivism understood as a metaethical view. I compare and contrast constructivism with three other standard metaethical positions with which it is often confused or mistakenly thought to be compatible: realism; naturalist reductions in terms of an ideal response; and expressivism. In discussing the contrast with expressivism, I explain the sense in which, according to the constructivist, the distinction between substantive normative ethics and metaethics breaks down. I conclude by distinguishing between two importantly different debates about the mind‐dependence of value. I argue that a failure to make this distinction is part of what explains why the possibility of constructivism as a metaethical view is often overlooked.
Who’s Who from Kant to Hegel II: Art and the Absolute
Authors: Thielke Peter Graham
Published: May 2010

Kant’s ‘Copernican Revolution’, which began in the Critique of Pure Reason (1781/1787), had, by the early 1790s, fundamentally altered the terrain of German philosophy – but not entirely in the way that Kant had foreseen. Skeptical challenges to Kant’s discursive account of cognition, in which experience arises from the separate faculties of sensibility and understanding, had led thinkers such as K.L. Reinhold and J.G. Fichte to attempt to provide a first, foundational principle for the critical philosophy. These efforts were enormously influential, but by the middle of the 1790s, they too were facing a great deal of critical scrutiny. The central challenge to the Fichtean project came from an unlikely quarter: a group of young thinkers and poets who are collectively known as the early Romantics. For the Romantics, Fichte’s project remains too ‘subjectivist’, for it tries to provide an account of the world by beginning with the conditions that govern subjectivity alone. Rather, the Romantics argue that the world must be understood in terms of a monistic Absolute, akin to Spinoza’s substance, in which all dualisms are overcome. It is with this step that Absolute Idealism comes on the scene, and sets the stage for the development of Hegel’s system in the early 1800s. This essay, which continues the story of ‘Who’s Who from Kant to Hegel I’, examines the ways in which early Romanticism reacted to the Fichtean project, looks at a variety of anti‐foundationalist idealisms that the Romantics – in particular Hölderlin, Novalis, Schlegel, and Schleiermacher – developed, and traces the role that Friedrich Schelling plays in offering the first systematic account of Absolute Idealism.
Quinone reductase 2 and antidepressant effect of melatonin derivatives
Authors: Oxenkrug Gregory F. , Bachurin Sergey O. , Prakhie Irina V. , Zefirov Nikolai S.
Published: May 2010

Melatonin and its immediate precursor, N‐acetylserotonin (NAS), exert antidepressant effects in experimental models and clinical studies. We reported that melatonin and NAS decreased immobility time (an indicator of antidepressant activity) in the mouse tail suspension test. Melatonin type 3 receptor (MT3) was identified as the same protein as quinone reductase 2 (QR2) detoxifying and antioxidant enzyme. To further elucidate the role of QR2/MT3 in antidepressant action of NAS and melatonin, we studied the effect of QR2/MT3 agonist and antagonist in a tail suspension test. QR2/MT3 agonist 5‐MCA‐NAT decreased, while the QR2/MT3 antagonist prazosin increased the duration of immobility in the tail suspension test in a dose‐dependent manner. Prazosin, in a dose that did not affect the duration of immobility, attenuated the antidepressant‐like effect of NAS, melatonin, and typical tricyclic antidepressant, amitriptyline, in the tail suspension test. Our results suggest that the modulation of QR2/MT3 might contribute to mechanism(s) of antidepressant effect. New antidepressants might be searched among the agonists of QR2/MT3.
Marriage and Family Therapists Working With Couples Who Have Children With Autism
Authors: Ramisch Julie
Published: May 2010

Current research about families and couples who have children with autism is discussed using the Double ABCX model as a guide. A case study is presented along with recommendations for therapists who work with couples who have children with autism. Marriage and family therapists are encouraged to use the Double ABCX model as both an assessment tool as well as for intervention. More research and effective therapists in this area are needed in order to keep up with the rising rates of families that include children diagnosed with autism.
First histopathological and immunophenotypic analysis of early dynamic events in a patient with segmental vitiligo associated with halo nevi
Authors: Van Geel Nanja A. C. , Mollet Ilse G. , De Schepper Sofie , Tjin Esther P. M. , Vermaelen Karim , Clark Rachael A. , Kupper Thomas S. , Luiten Rosalie M. , Lambert Jo
Published: May 2010

Segmental vitiligo is often ascribed to the neurogenic theory of melanocyte destruction, although data about the initial etiopathological events are scarce. Clinical, histopathological and T‐cell phenotypic analyses were performed during the early onset of a segmental vitiligo lesion in a patient with associated halo nevi. Histopathological analysis revealed a lymphocytic infiltrate, mainly composed of CD8+ T‐cells and some CD4+ T‐cells around the dermo–epidermal junction. Flow cytometry analysis of resident T‐cells revealed a clear enrichment of pro‐inflammatory IFN‐γ producing CD8+ T‐cells in lesional skin compared to the non‐lesional skin. Using human leukocyte antigen‐peptide tetramers (MART‐1, tyrosinase, gp100), increased numbers of T cells, recognizing melanocyte antigens were found in segmental vitiligo lesional skin, as compared with the non‐lesional skin and the blood. Our findings indicate that a CD8+ melanocyte specific T cell‐mediated immune response, as observed in generalized vitiligo, also plays a role in segmental vitiligo with associated halo nevi.
Provisioning Responsibilities: How Relationships Shape the Work that Women Do
Authors: NEYSMITH SHEILA M. , REITSMA‐STREET MARGE , BAKER‐COLLINS STEPHANIE , PORTER ELAINE , TAM SANDRA
Published: May 2010

Cette étude documente le travail d'approvisionnement que les femmes effectuent pour elles‐mêmes et pour les autres, tout en enregistrant les contours de ce travail et en analysant les responsabilités qui y sont associées. Le concept d'approvisionnement a orienté les interviews réalisées auprès de 100 femmes. La diversité et l'étendue du travail des femmes se sont manifestées par le choix des femmes provenant de six groupes communautaires marginalisés par le revenu, la race ou l'âge dans deux provinces canadiennes. Les résultats résument les types d'activités et de stratégies d'approvisionnement que les femmes utilisent pour assumer leurs responsabilités. Parce que celles‐ci font partie des avenues de leurs relations, négocier les limites de leurs responsabilités d'approvisionnement modèle le travail quotidien des femmes et leurs possibilités de s'engager dans la société civile.

This study documents the work women do to provision for themselves and others. It charts the contours of this work and examines associated responsibilities. The concept of provisioning informed interviews with 100 women. The diversity and range of women's work were surfaced by selecting women from six community groups, marginalized by income, race, and age, in two Canadian provinces. Findings summarize the types of provisioning activities and strategies women use to meet their responsibilities. Because the latter flow through pathways of relationships, negotiating the boundaries of their provisioning responsibilities shapes women's daily work and possibilities for engaging in civil society.
The NCTM Process Standards and the Five Es of Science: Connecting Math and Science
Authors: Bossé Michael J. , Lee Tammy D. , Swinson Michael , Faulconer Johna
Published: May 2010

This study investigates defining characteristics among the process standards of the Principles and Standards for School Mathematics and the 5 Es from the National Science Education Standards and the Inquiry and the National Science Education Standards. These characteristics are used to demonstrate similarities and differences between the learning of mathematics and science, discuss implications from such, and argue for the integration of mathematics and science curriculum and instruction.
Evaluation of the Interaction Losses in a Transonic Turbine HP Rotor/LP Vane Configuration
Authors: Jennions I. K. , Adamczyk J. J.
Published: May 2010

Transonic turbine rotors produce shock waves, wakes, tip leakage flows, and other secondary flows that the downstream stators have to ingest. While the physics of wake ingestion and shock interaction have been studied quite extensively, few ideas for reducing the aerodynamic interaction losses have been forthcoming. This paper aims to extend previously reported work performed by GE Aircraft Engines in this area. It reports on both average-passage (steady) and unsteady three-dimensional numerical simulations of a candidate design to shed light on the interaction loss mechanisms and evaluate the design. The results from these simulations are first shown against test data for a baseline configuration to engender confidence in the numerical approach. Simulations with the proposed newly designed rotor are then performed to show the trade-offs that are being made in such designs. The new rotor does improve the overall efficiency of the group and physical explanations are presented based on examining entropy production.
Three-Dimensional Unsteady Flow and Forces in Centrifugal Impellers With Circumferential Distortion of the Outlet Static Pressure
Authors: Fatsis A. , Pierret S. , Van den Braembussche R.
Published: May 2010

This paper describes the numerical investigation of the centrifugal impeller response to downstream static pressure distortions imposed by volutes at off-design operations. An unsteady three-dimensional Euler solver with nonreflecting upstream and down-stream boundary conditions and phase-lagged periodicity conditions is used for this purpose. The mechanisms governing the unsteady flow field are analyzed. A parametric study shows the influence of the acoustic Strouhal number on the amplitude of the flow perturbations. Radial forces calculated on backward leaned and radial ending centrifugal impellers show nonnegligible influence of the impeller geometry.
Airflow and Cooling in a Data Center
Authors: Patankar Suhas V.
Published: May 2010

This paper deals with the distribution of airflow and the resulting cooling in a data center. First, the cooling challenge is described and the concept of a raised-floor data center is introduced. In this arrangement, cooling air is supplied through perforated tiles. The flow rates of the cooling air must meet the cooling requirements of the computer servers placed next to the tiles. These airflow rates are governed primarily by the pressure distribution under the raised floor. Thus, the key to modifying the flow rates is to influence the flow field in the under-floor plenum. Computational fluid dynamics (CFD) is used to provide insight into various factors affecting the airflow distribution and the corresponding cooling. A number of ways of controlling the airflow distribution are explored. Then attention is turned to the above-floor space, where the focus is on preventing the hot air from entering the inlets of computer serves. Different strategies for doing this are considered. The paper includes a number of comparisons of measurements with the results of CFD simulations.
Numerical Studies on Microwave Heating of Thermoplastic-Ceramic Composites Supported on Ceramic Plates
Authors: Basak Tanmay , Durairaj Sankaran
Published: May 2010

A detailed theoretical analysis has been carried out to study efficient microwave assisted heating of thermoplastic (Nylon 66) slabs via polymer-ceramic-polymer composite attached with ceramic plate at one side. The ceramic layer or plate is chosen as Al2O3 or SiC. The detailed spatial distributions of power and temperature are obtained via finite element simulation. It is found that uniform heating with enhanced processing rate may occur with specific thickness of Al2O3 composite, whereas SiC composite leads to enhanced processing rate with higher thermal runaway for thick Nylon samples attached with Al2O3 plate. SiC composite is effective due to enhanced processing rate, whereas Al2O3 is not effective due to reduced processing rate for thin samples attached with Al2O3 plate. For samples attached with SiC plate, thermal runaway is reduced by SiC composite, whereas that is not reduced by Alumina composite. Current study recommends efficient heating methodologies for thermoplastic substances with ceramic composite to achieve a higher processing rate with uniform temperature distribution.
Network Modeling of Fin-and-Tube Evaporator Performance Under Dry and Wet Conditions
Authors: Zhao Ling-Xiao , Yang Liang , Zhang Chun-Lu
Published: May 2010

A new neural network modeling approach to the evaporator performance under dry and wet conditions has been developed. Not only the total cooling capacity but also the sensible heat ratio and pressure drops on both air and refrigerant sides are modeled. Since the evaporator performance under dry and wet conditions is, respectively, dominated by the dry-bulb temperature and the web-bulb temperature, two neural networks are used together for capturing the characteristics. Training of a multi-input multi-output neural network is separated into training of multi-input single-output neural networks for improving the modeling flexibility and training efficiency. Compared with a well-developed physics-based model, the standard deviations of trained neural networks under dry and wet conditions are less than 1% and 2%, respectively. Compared with the experimental data, errors fall into ±5%.
Thermal Wave Based on the Thermomass Model
Authors: Guo Zeng-Yuan , Hou Quan-Wen
Published: May 2010

In times comparable to the characteristic time of the energy carriers, Fourier’s law of heat conduction breaks down and heat may propagate as waves. Based on the concept of thermomass, which is defined as the equivalent mass of phonon gas in dielectrics, according to the Einstein’s mass-energy relation, the phonon gas in the dielectrics is described as a weighty, compressible fluid. Newton mechanics has been applied to establish the equation of state and the equation of motion for the phonon gas as in fluid mechanics, because the drift velocity of a phonon gas is normally much less than the speed of light. The propagation velocity of the thermal wave in the phonon gas is derived directly from the equation of state for the phonon gas, rather than from the relaxation time in the Cattaneo–Vernotte (CV) model (Cattaneo, C., 1948, “Sulla Conduzione Del Calore,” Atti Semin. Mat. Fis. Univ. Modena, 3, pp. 83–101; Vernotte, P., 1958, “Paradoxes in the Continuous Theory of the Heat Equation,” C. R. Acad. Bulg. Sci., 246, pp. 3154–3155). The equation of motion for the phonon gas gives rise to the thermomass model, which depicts the general relation between the temperature gradient and heat flux. The linearized conservation equations for the phonon gas lead to a damped thermal wave equation, which is similar to the CV-wave equation, but with different characteristic time. The lagging time in the resulting thermal wave equation is related to the wave velocity in the phonon gas, which is approximately two orders of magnitude larger than the relaxation time adopted in the CV-wave model for the lattices. A numerical example for fast transient heat conduction in a silicon film is presented to show that the temperature peaks resulting from the thermomass model are much higher than those resulting from the CV-wave model. Due to the slower thermal wave velocity in the phonon gas, by as much as one order of magnitude, the damage due to temperature overshooting may be more severe than that expected from the CV-wave model.
Reduced Models for Radiative Heat Transfer Analysis Through Anisotropic Fibrous Medium
Authors: Kamdem Hervé Thierry Tagne , Baillis Dominique Doermann
Published: May 2010

Reduced models for radiative heat transfer analysis through anisotropic medium are presented and evaluated. The models include two equivalent heat transfer models through isotropic medium using isotropic or Henyey–Greenstein scattering phase functions with arithmetic or weighted means radiative properties calculated over all incident direction and an anisotropic model with directional radiative properties coupled to an isotropic scattering phase function or directional anisotropically scattering phase function. The pertinence of the models is investigated by solving coupled conduction/radiation heat transfer through a slab of anisotropic fibrous medium with fiber randomly oriented in the plan parallel to the boundaries. Good agreements on heat fluxes and thermal conductivity are obtained for reduced anisotropic models and for reduced equivalent isotropic models with weighted mean radiative properties.
Viscous Dissipation and Rarefaction Effects on Laminar Forced Convection in Microchannels
Authors: Sadeghi Arman , Saidi Mohammad Hassan
Published: May 2010

Fluid flow in microchannels has some characteristics, which one of them is rarefaction effect related with gas flow. In the present work, hydrodynamically and thermally fully developed laminar forced convection heat transfer of a rarefied gas flow in two microgeometries is studied, namely, microannulus and parallel plate microchannel. The rarefaction effects are taken into consideration using first-order slip velocity and temperature jump boundary conditions. Viscous heating is also included for either the wall heating or the wall cooling case. Closed form expressions are obtained for dimensionless temperature distribution and Nusselt number. The results demonstrate that for both geometries, as Brinkman number increases, the Nusselt number decreases. However, the effect of viscous heating on the Nusselt number at greater values of Knudsen number becomes insignificant. In the absence of viscous heating, increasing values of Knudsen number lead to smaller values of Nusselt number. Furthermore, it is observed that viscous heating causes singularities in Nusselt number values. Also, asymmetry causes singularities in Nusselt numbers of both microannulus walls and the parallel plate wall having lower heat flux, even in the absence of viscous heating. For parallel plate microchannel, in the absence of viscous heating, Nusselt number of the wall having larger heat flux is an increasing function of the wall heat fluxes ratio.
COTS BGA Thermal Fatigue Test for Avionics Applications
Authors: Fenger H. S. , Wong T. E.
Published: May 2010

The objectives of the present studies are to design and test representative commercial off-the-shelf plastic encapsulated microcircuits, including various types of ball grid array (BGA) components, chip scale package, and flip chip over military thermal environment. The approach is to demonstrate the solder joint reliability performance of these components through the design of an electrical daisy-chain pattern printed wiring board (PWB) assembly test vehicle (TV), in which the design and manufacturing variables are included. The variables, including the types of PWBs, conformal coating, and BGA underfilled materials, with each having either two or three levels of variation are used to address test criteria and to construct 12 different types of TV configurations. All TV configurations are then subjected to temperature cycling tests (−55°C to +125°C) while continuously monitoring solder joint integrity. Based on the measured results, a destructive physical analysis is then conducted to further isolate the failure locations and determine the failure mechanisms of the solder joints. Based on the lesson-learned from the above TV, a second TV (defined as TV2) has been designed, constructed and tested. The four selected parameters in TV2 are BGA under-fill materials, conformal coating, solder pad sizes on PWB, and BGA rework, with each also having either two or three levels of variation. Test results from these two groups of TVs indicate that the influence of these design and manufacturing parameters on fatigue life is dependent on the particular package, in some instances improving the fatigue life tenfold. All these test results are recommended to be used for calibrating BGA solder joint thermal fatigue life prediction models, which will be presented in other publications.
Temperature Measurement by Using Metal Thin Film Thermocouples
Authors: Miyazaki Koji , Tsukamoto Hiroshi , Miike Takahiro , Takamiya Toshiaki
Published: May 2010

We fabricate metal thin film thermocouples (TFTCs). Au-Pt, Cu-Ni, and W-Ni are deposited on a glass plate using standard thin film processes. The dimension of thermocouple junction is 300μm × 300μm. The thermoelectric powers of TFTCs are different from those of bulk because diffusion of electrons is restricted by the very thin film. The film thickness of TFTCs is of the same order as the mean free path of electrons. However TFTCs are still useful for temperature measurements because the thermoelectric voltage is proportional to measured temperature at thermocouple junction. The response time of Au-Pt TFTCs is about 30ns when the surface of the glass is heated by a YAG pulsed laser. The result compares favorably with measurements by a thermoreflectance method. We also describe W-Ni nano-TFTCs fabricated by Focused Ion Beam for the measurement of temperature distribution in a sub-micron area. In order to reduce the size of the TFTCs we employ a 3-dimensional structure.
Studies With Transient Compact Models of Packages and Heat Sinks
Authors: Rencz M. , Sze´kely V. , Courtois B.
Published: May 2010

This paper deals with the application of dynamic compact thermal models of packages. First an algorithm and a methodology is presented, that was developed for the inclusion of compact electrical RC thermal models of packages into field solvers, to enable fast board level simulation with compact models of packages. Application examples demonstrate the advantages of the method. In the second part of the paper a method is presented for the generation of nonlinear compact models. Simulation experiments comparing linear and nonlinear compact models show that for small temperature excursions the use of linear models is acceptable, but in case of larger than 80°C temperature increases the use of linear models results in an about 20–30% regular error for the usual package structures.
Three-Dimensional Stress Singularity Analysis Around the Solder Joints in Electronic Packaging Using Eigen Analysis
Authors: Prukvilailert Monchai , Koguchi Hideo
Published: May 2010

Electronic packaging has several kinds of joint structures of metal, ceramic and polymer. It is well known that the stress singularity occurs at the vertex of joint where the dissimilar materials are bonded together. In this paper, the model in the first analysis is an electronic package using surface mount technology (SMT), the order of stress singularity is investigated, when the mechanical properties of solder, adhesive and resin vary for several values of contact angles between the solder with the chip and with a Cu land. Furthermore, the model in the second analysis is a Flip-Chip-on-Board packaging (FCOB), in which the order of stress singularity at the solder bump is investigated varying the mechanical properties of solder, underfill and the contact angle between the solder bump with a Cu track. After that, the displacement and stress fields for several values of the order of stress singularity are calculated by solving an eigen equation.
Mechanical Stress-Induced Damage on Breakdown Characteristic of Dielectric Thin Films in MOS Transistors
Authors: Miura Hideo , Moriya Hiroshi
Published: May 2010

Mechanical Stress-induced deterioration of the breakdown characteristic of SiO2 films was discussed analytically and experimentally. The decrease in the band gap of the oxide due to the crystal deformation is the main reason for the deterioration. The change rate was analyzed by the first principles calculation. The mechanism of the stress development in a MOS transistor structure was clarified by stress measurement of thin films. The intrinsic stress of the thin films used for the gate electrode of the transistor is the important factor for determining the residual stress in the oxide under the electrode. The residual stress in the silicon substrate before the oxide (SiO2) formation (surface oxidation of the substrate) is another important factor which affects the quality of the oxide film. In particular, the density of the unstable atomic bonding of silicon near the Si/SiO2 interface varies depending on the stress in the substrate.
Thermo-Mechanical Deformation and Stress Analysis of a Flip-Chip BGA
Authors: Wu J. D. , Lai Y. S. , Kuo Y. L. , Hung S. C. , Jen M.-H. R.
Published: May 2010

This paper investigates thermo-mechanical deformation and stresses of a flip-chip package (FCBGA) with and without underfill materials. Chip carrier is a 2-2-2 build-up substrate with 40 × 40 mm2 dimension; while bump material employs Sn/37Pb eutectic solder. Temperature-dependent warpage (out-of-plane displacement) of a FCBGA is characterized via shadow moire´ technique. Results of warpage measurement reveal that packages do not follow the same path during thermal loading/unloading cycle (20-220-20 °C) for both FCBGA with and without underfills. This implies that both solder and underfill exhibit inelastic material response. Therefore, it is a necessity to consider nonlinear constitutive response of packaging materials when designing flip-chip packages. It is observed that FCBGA with underfill exhibit more warpage than packages without underfill due to higher CTE mismatch between underfills and silicon dies. Aspect of package geometry such as die-to-substrate thickness ratio is found to play important role in reducing package stresses. Especially, thinner die provides more direct impact to die stresses reduction than thinner substrate does.
Three-Dimensional Simulation of Thermoelectric Devices With Compact Numerical Models
Authors: Prather Eric , Puranik Bhalchandra
Published: May 2010

Thermoelectric cooling modules (TECs) are widely used within electronic equipment for both temperature reduction and control of individual components. The techniques presented in this paper demonstrate that it is possible to construct a simple three-zone model, that represents the transient and 3D properties of a typical TEC, and can be easily built within existing CFD software packages for a known electric current or voltage input. A comparison of compact model results, detailed model results, and experimental results is presented for a typical electronics cooling setup, including a heat source (from which heat is absorbed by the TEC), TEC device, and air-cooled heat sink. Variables examined include heat source power dissipation, TEC current, and heat sink airflow. Finally, the response of the setup to a step function in current is examined to investigate the transient performance of the compact model.
Nondestructive Inspection of Chip Size Package by Millimeter Waves
Authors: Ju Yang , Yamamoto Hiroshi , Saka Masumi
Published: May 2010

Chip size package was inspected by millimeter waves. Millimeter wave image was created using the phase and amplitude of the reflection coefficient, measured by a network analyzer. To obtain a high spatial resolution, an open-ended coaxial line sensor was used. Solder bumps and delamination under the silicon chip of the package were observed effectively. It is shown that millimeter wave technique has a good prospect for integrity assessment of chip size package.