bluuebunny/crossref_metadata_2025 huggingface dataset:
Deciding to Opt Out of Childhood Vaccination Mandates
Authors: Gullion Jessica Smartt , Henry Lisa , Gullion Greg
Published: August 2008

ABSTRACT
Objectives: We explore the attitudes and beliefs of parents who consciously choose not to vaccinate their children and the ways in which these parents process information on the pros and cons of vaccines.

Design: In‐depth, semistructured interviews were conducted.

Sample: The study population consisted of 25 parents who do not vaccinate their children, identified through snowball and targeted sampling.

Methods: Participants were asked about their processes and actions when choosing not to vaccinate their children. Interviews were taped and transcribed, and the content was analyzed for emergent themes.

Results: Two predominant themes emerged in our data: a desire to collect information on vaccines and trust issues with the medical community. Evidence of sophisticated data collection and information processing was a repeated theme in the interview data. Simultaneously, while participants placed a high value on scientific knowledge, they also expressed high levels of distrust of the medical community.

Conclusions: The challenge for public health is to balance scientific data with popular epidemiology and to maintain legitimacy. Understanding the differences in lay versus expert knowledge has implications for crafting health messages. How experts frame knowledge for consumption has an important impact on this group and their decision‐making processes.
Influence of Communicator's Race on Efficacy of an HIV/STD Prevention Intervention Among African American and Caucasian College Students
Authors: Helion Alicia M. , Reddy Diane M. , Kies Ashley L. , Morris Deirdre R. , Wilson Clarissa M.
Published: August 2008

ABSTRACT
Objectives: The present research examined the influence of communicator's race on the efficacy of intervention videos in the reduction of human immunodeficiency virus (HIV) and other sexually transmitted diseases (STDs) among African American and Caucasian college females.

Design: Experimental HIV/STD prevention digital versatile disks (DVDs) featured a White female as a primary or a secondary communicator relative to a Black female, while a control DVD featured 2 Black females. Respondents watched 1 DVD and completed questionnaires before and after viewing the DVD as well as 2 and 4 weeks later.

Sample: 79 African American females and 88 Caucasian females participated.

Measurements: Perceptions of the DVDs, HIV/STD risk, intentions to use condoms, and number of condoms purchased after viewing the videos were assessed.

Results: The intervention was effective in increasing intentions to use condoms with a current partner across the follow‐up periods. There was no effect of race of communicator on any variable for African American or Caucasians.

Conclusions: While communicator's race did not affect this intervention, more research is necessary. Future studies should use multiple Black and White communicators to isolate the role of race and should be conducted where larger samples of African American college students can be recruited.
Legacy Leadership: The Beverly Flynn Public Health Nursing Mentorship: Tribute to a Nursing Mentor
Authors: Belcher Anne S.
Published: August 2008

ABSTRACT
The manuscript presents the background and history of the Beverly C. Flynn Legacy Leadership Award sponsored by the American Public Health Association's (APHA) Public Health Nursing Section. The Flynn Legacy Leadership program recognizes graduate students majoring in public health/community health nursing, and novice public health nurses for their potential to be future leaders in public health nursing. The importance of the mentoring relationship in promoting the standards of practice for public health nursing is explored. The Flynn Legacy Leadership Program fosters meaningful connections in the public health nursing community beyond the scope of the annual meeting. Award winners from the three years of the program are showcased with examples of scholarship fostered through the Beverly C. Flynn Legacy Leadership Award.
Derivation of Noncancer Reference Values for Acrylonitrile
Authors: Kirman C. R. , Sweeney L. M. , Gargas M. L. , Strother D. E. , Collins J. J. , Deskin R.
Published: August 2008

Dose‐response assessments were conducted for the noncancer effects of acrylonitrile (AN) for the purposes of deriving subchronic and chronic oral reference dose (RfD) and inhalation reference concentration (RfC) values. Based upon an evaluation of available toxicity data, the irritation and neurological effects of AN were determined to be appropriate bases for deriving reference values. A PBPK model, which describes the toxicokinetics of AN and its metabolite 2‐cyanoethylene oxide (CEO) in both rats and humans, was used to assess the dose‐response data in terms of an internal dose measure for the oral RfD values, but could not be used in deriving the inhalation RfC values. Benchmark dose (BMD) methods were used to derive all reference values. Where sufficient information was available, data‐derived uncertainty factors were applied to the points of departure determined by BMD methods. From this assessment, subchronic and chronic oral RfD values of 0.5 and 0.05 mg/kg/day, respectively, were derived. Similarly, subchronic and chronic inhalation RfC values of 0.1 and 0.06 mg/m3, respectively, were derived. Confidence in the reference values derived for AN was considered to be medium to high, based upon a consideration of the confidence in the key studies, the toxicity database, dosimetry, and dose‐response modeling.
Assessment of the Effectiveness of Radon Screening Programs in Reducing Lung Cancer Mortality
Authors: Gagnon Fabien , Courchesne Mathieu , Lévesque Benoît , Ayotte Pierre , Leclerc Jean‐Marc , Belles‐Isles Jean‐Claude , Prévost Claude , Dessau Jean‐Claude
Published: August 2008

The present study was aimed at assessing the health consequences of the presence of radon in Quebec homes and the possible impact of various screening programs on lung cancer mortality. Lung cancer risk due to this radioactive gas was estimated according to the cancer risk model developed by the Sixth Committee on Biological Effects of Ionizing Radiations. Objective data on residential radon exposure, population mobility, and tobacco use in the study population were integrated into a Monte‐Carlo‐type model. Participation rates to radon screening programs were estimated from published data. According to the model used, approximately 10% of deaths due to lung cancer are attributable to residential radon exposure on a yearly basis in Quebec. In the long term, the promotion of a universal screening program would prevent less than one death/year on a province‐wide scale (0.8 case; IC 99%: –3.6 to 5.2 cases/year), for an overall reduction of 0.19% in radon‐related mortality. Reductions in mortality due to radon by (1) the implementation of a targeted screening program in the region with the highest concentrations, (2) the promotion of screening on a local basis with financial support, or (3) the realization of systematic investigations in primary and secondary schools would increase to 1%, 14%, and 16.4%, respectively, in the each of the populations targeted by these scenarios. Other than the battle against tobacco use, radon screening in public buildings thus currently appears as the most promising screening policy for reducing radon‐related lung cancer.
A 6‐year investigation into types of dental trauma treated in a paediatric dentistry clinic in Eastern Anatolia Region, Turkey
Authors: Eyuboglu Ozge , Yilmaz Yucel , Zehir Cigdem , Sahin Hakan
Published: August 2008

Abstract –  The purpose of this study was to assess the frequency, the effective factors and the applied treatments for dental trauma among children aged 1–15 years from Eastern Anatolia in a 6‐year period. The total frequency of trauma in this study was calculated as 4.9% during a 6‐year period. The males were found to have more traumatic injury than females (P < 0.05). Also, the permanent teeth were more vulnerable to dental trauma than the primary teeth (P < 0.05). The highest frequency of traumas in the primary teeth was observed at the age of 5, whereas the rate for the permanent teeth was at the age of 10. The teeth mostly influenced by the traumas were the upper central incisors in both primary and permanent teeth. It was in October that traumas were mostly seen for the permanent teeth and in June for the primary teeth. The most frequent source of trauma in both genders and in both primary and permanent teeth were falls. The most common type of trauma in the primary teeth was lateral luxation, while it was enamel‐dentin crown fracture in the permanent ones. Soft tissue injuries were observed in 143 of 653 dental traumatized children. The most common method of treatment was examination and follow up for the primary teeth, and only direct restoration for the permanent teeth without any endodontic treatment. 15% of the patients applied for treatment 1 year after injury event. Therefore, it was concluded that the patients, parents and teachers living in Eastern Anatolia should be informed about the necessity of early treatment of dental traumas and the consequence of a delay.
High‐resolution genetic mapping of mammalian motor activity levels in mice
Authors: Kas M. J. H. , De Mooij‐van Malsen J. G. , De Krom M. , Van Gassen K. L. I. , Van Lith H. A. , Olivier B. , Oppelaar H. , Hendriks J. , De Wit M. , Groot Koerkamp M. J. A. , Holstege F. C. P. , Van Oost B. A. , De Graan P. N. E.
Published: August 2008

The generation of motor activity levels is under tight neural control to execute essential behaviors, such as movement toward food or for social interaction. To identify novel neurobiological mechanisms underlying motor activity levels, we studied a panel of chromosome substitution (CS) strains derived from mice with high (C57BL/6J strain) or low motor activity levels (A/J strain) using automated home cage behavioral registration. In this study, we genetically mapped the expression of baseline motor activity levels (horizontal distance moved) to mouse chromosome 1. Further genetic mapping of this trait revealed an 8.3‐Mb quantitative trait locus (QTL) interval. This locus is distinct from the QTL interval for open‐field anxiety‐related motor behavior on this chromosome. By data mining, an existing phenotypic and genotypic data set of 2445 genetically heterogeneous mice (http://gscan.well.ox.ac.uk/), we confirmed linkage to the peak marker at 79 970 253 bp and refined the QTL to a 312‐kb interval containing a single gene (A830043J08Rik). Sequence analysis showed a nucleotide deletion in the 3′ untranslated region of the Riken gene. Genome‐wide microarray gene expression profiling in brains of discordant F2 individuals from CS strain 1 showed a significant upregulation of Epha4 in low‐active F2 individuals. Inclusion of a genetic marker for Epha4 confirmed that this gene is located outside of the QTL interval. Both Epha4 and A830043J08Rik are expressed in brain motor circuits, and similar to Epha4 mutants, we found linkage between reduced motor neurons number and A/J chromosome 1. Our findings provide a novel QTL and a potential downstream target underlying motor circuitry development and the expression of physical activity levels.
Relationship between chewing ability and high‐level functional capacity in an 80‐year‐old population in Japan
Authors: Takata Yutaka , Ansai Toshihiro , Soh Inho , Akifusa Sumio , Sonoki Kazuo , Fujisawa Kiyoshi , Yoshida Akihiro , Kagiyama Shuntaro , Hamasaki Tomoko , Nakamichi Ikuo , Awano Shuji , Torisu Takehiro , Takehara Tadamichi
Published: August 2008

Objectives:  To evaluate the association between high‐level functional capacity and chewing in a middle‐old community‐based population.

Background:  Although basic and instrumental activities of daily living are known to be associated with chewing ability in the elderly, an association between higher levels of competence and chewing ability has not been evaluated in the elderly.

Materials and methods:  The association between chewing ability using a number of different foods and high‐level functional capacity by the Tokyo Metropolitan Institute of Gerontology was evaluated in 694, 80‐year‐old people residing in Fukuoka Prefecture, Japan.

Results:  A significant correlation was found, using multiple regression or logistic regression analyses adjusted for various confounding factors, between the number of total chewable foods, hard foods or moderately hard foods, and total functional capacity, instrumental activity, intellectual activity or social role ability. In contrast, the number of slightly hard foods, easily chewable foods and remaining teeth were only partly related to total functional capacity and intellectual activity.

Conclusion:  High‐level functional capacity including intellectual activity and social role in middle‐old elderly was associated with the ability to chew hard foods than to chew easily chewable foods. Maintenance of chewing ability in elderly might result in better intellectual activity and social role.
Matrilysin (matrix metalloprotease‐7) cleaves membrane‐bound annexin II and enhances binding of tissue‐type plasminogen activator to cancer cell surfaces
Authors: Tsunezumi Jun , Yamamoto Kazuhiro , Higashi Shouichi , Miyazaki Kaoru
Published: August 2008

Matrilysin (matrix metalloproteinase‐7) plays important roles in tumor progression. It was previously found that matrilysin binds to the surface of colon cancer cells to promote their metastatic potential. In this study, we identified annexin II as a novel membrane‐bound substrate of matrilysin. Treatment of human colon cancer cell lines with active matrilysin released a 35 kDa annexin II form, which lacked its N‐terminal region, into the culture supernatant. The release of the 35 kDa annexin II by matrilysin was significantly enhanced in the presence of serotonin or heparin. Matrilysin hydrolyzed annexin II at the Lys9–Leu10 bond, thus dividing the protein into an N‐terminal nonapeptide and the C‐terminal 35 kDa fragment. Annexin II is known to serve as a cell surface receptor for tissue‐type plasminogen activator (tPA). Although the matrilysin treatment liberated the 35 kDa fragment of annexin II from the cell surface, it significantly increased tPA binding to the cell membrane. A synthetic N‐terminal nonapeptide of annexin II bound to tPA more efficiently than intact annexin II. This peptide formed a heterodimer with intact annexin II in test tubes and on cancer cell surfaces. These and other results suggested that the nonapeptide generated by matrilysin treatment might be anchored to the cell membrane, possibly by binding to intact annexin II, and interact with tPA via its C‐terminal lysine. It is supposed that the cleavage of cell surface annexin II by matrilysin contributes to tumor invasion and metastasis by enhancing tPA‐mediated pericellular proteolysis by cancer cells.
Effect of the disease‐causing mutations identified in human ribonuclease (RNase) H2 on the activities and stabilities of yeast RNase H2 and archaeal RNase HII
Authors: Rohman Muhammad S. , Koga Yuichi , Takano Kazufumi , Chon Hyongi , Crouch Robert J. , Kanaya Shigenori
Published: August 2008

Eukaryotic ribonuclease (RNase) H2 consists of one catalytic and two accessory subunits. Several single mutations in any one of these subunits of human RNase H2 cause Aicardi–Goutières syndrome. To examine whether these mutations affect the complex stability and activity of RNase H2, three mutant proteins of His‐tagged Saccharomyces cerevisiae RNase H2 (Sc‐RNase H2*) were constructed. Sc‐G42S*, Sc‐L52R*, and Sc‐K46W* contain single mutations in Sc‐Rnh2Ap*, Sc‐Rnh2Bp*, and Sc‐Rnh2Cp*, respectively. The genes encoding the three subunits were coexpressed in Escherichia coli, and Sc‐RNase H2* and its derivatives were purified in a heterotrimeric form. All of these mutant proteins exhibited enzymatic activity. However, only the enzymatic activity of Sc‐G42S* was greatly reduced compared to that of the wild‐type protein. Gly42 is conserved as Gly10 in Thermococcus kodakareansis RNase HII. To analyze the role of this residue, four mutant proteins, Tk‐G10S, Tk‐G10A, Tk‐G10L, and Tk‐G10P, were constructed. All mutant proteins were less stable than the wild‐type protein by 2.9–7.6 °C in Tm. A comparison of their enzymatic activities, substrate binding affinities, and CD spectra suggests that the introduction of a bulky side chain into this position induces a local conformational change, which is unfavorable for both activity and substrate binding. These results indicate that Gly10 is required to make the protein fully active and stable.
Interactions between the Fyn SH3‐domain and adaptor protein Cbp/PAG derived ligands, effects on kinase activity and affinity
Authors: Solheim Silje A. , Petsalaki Evangelia , Stokka Anne J. , Russell Robert B. , Taskén Kjetil , Berge Torunn
Published: August 2008

Csk‐binding protein/phosphoprotein associated with glycosphingolipid‐enriched domains is a transmembrane adaptor protein primarily involved in negative regulation of T‐cell activation by recruitment of C‐terminal Src kinase (Csk), a protein tyrosine kinase which represses Src kinase activity through C‐terminal phosphorylation. Recruitment of Csk occurs via SH2‐domain binding to PAG pTyr317, thus, the interaction is highly dependent on phosphorylation performed by the Src family kinase Fyn, which docks onto PAG using a dual‐domain binding mode involving both SH3‐ and SH2‐domains of Fyn. In this study, we investigated Fyn SH3‐domain binding to 14‐mer peptide ligands derived from Cbp/PAG‐enriched microdomains sequence using biochemical, biophysical and computational techniques. Interaction kinetics and dissociation constants for the various ligands were determined by SPR. The local structural impact of ligand association has been evaluated using CD, and molecular modelling has been employed to investigate details of the interactions. We show that data from these investigations correlate with functional effects of ligand binding, assessed experimentally by kinase assays using full‐length PAG proteins as substrates. The presented data demonstrate a potential method for modulation of Src family kinase tyrosine phosphorylation through minor changes of the substrate SH3‐interacting motif.
SOCIAL WORK AND LAW: A MODEL APPROACH TO INTERDISCIPLINARY EDUCATION, PRACTICE, AND COMMUNITY‐BASED ADVOCACY
Authors: Kozakiewicz Joseph
Published: August 2008

Many schools of social work maintain partnerships with schools in other fields, including law schools. Social work educators also seek to provide students with real‐life educational experiences. Schools maintain ties with community‐based organizations to facilitate field placements for students and also to effect social change. I review existing literature regarding social work interdisciplinary education, focusing on law and social work. I describe a social work program designed to provide students with interdisciplinary education both in the classroom and in the field and to effect community‐based advocacy. Finally, I describe pending research designed to measure the program's efficacy.
CONFLICT AND CO‐PARENTING: THE CONSTRUCTS OF NONRESIDENT FATHERS*
Authors: Wilson Graeme B.
Published: August 2008

Scots law constructs a co‐parental role for nonresident fathers without clarifying how this should operate in practice. Personal Construct Theory (PCT) offers a useful approach to understanding such fathers’ distinct and changing conceptions of their role. Findings are presented from a study of 17 nonresident Scottish fathers maintaining contact with nonresident children. Idiographic analysis of data from repertory grid interviews administered three times over the course of a year shows that participants perceive family situations in terms of paternal involvement, impact, emotion, or antagonism. Changes in construing following family events support the PCT understanding of hostility; implications for family services are discussed.
PARENTING COORDINATION (PC) PRACTICE: A SURVEY OF EXPERIENCED PROFESSIONALS
Authors: Kirkland Karl , Sullivan Matthew
Published: August 2008

This study summarizes a survey of experienced North American parenting coordinators (PCs). The survey was modeled after a similar seminal study of child custody evaluators (Keilen & Bloom, 1986) and seeks to establish a similar baseline standard in alternative dispute resolution (ADR) court‐sanctioned PC practices. Results reveal that PC is being practiced across North America by highly experienced practitioners that are multidisciplinary across legal and mental health professions who work by court order. These PCs work with a specific written PC agreement that specifies basis of authority, scope of authority, terms of service, retainer/fees, and grievance procedures. Results characterize PC as an increasingly established hybrid ADR court‐sanctioned role that is effective precisely because of accessibility to families, the unique knowledge base of the family law professional concerning the dynamics of divorcing families, and the court‐granted authority to help families resolve disputes that are generally more familial and psychological than legal in nature.
IRC § 71 MAY IMPOVERISH CHILDREN, ENDANGER EX‐WIVES, AND DISRUPT FEDERALISM1
Authors: Waggoner Michael
Published: August 2008

The Internal Revenue Code provides that alimony will be deductible to the payor and taxable to the payee. Although this treatment may seem contrary to the payee's interest, compared to making the payments non‐deductible and nontaxable, it can increase the payee's after‐tax income. The payor's deduction will allow larger payments at no after‐tax cost increase; if the payee is in a lower tax bracket, then even after paying taxes the payee will have more resources. Because this favorable treatment of alimony does not apply to child support, children of divorce are poorer. Nor does the favorable treatment apply to lump‐sum payments, making this option less generous, even though many states have phased down the grant of alimony. Because the definition of alimony requires that it end with the payee's death—to protect the treatment provided for lump sums—the tax system is on the wrong side of the issue of violence against ex‐spouses (typically the ex‐wife). The article proposes extending to other similar payments the favorable tax treatment now provided for alimony.
Features of tropical cyclone‐induced flood peaks on Grande Terre, New Caledonia
Authors: Terry James P. , Kostaschuk Ray A. , Wotling Geoffroy
Published: August 2008

New Caledonia, an archipelago of islands in the South Pacific, is periodically affected in the wet season by tropical cyclones that can deliver intense rainfall and cause severe river flooding. On the mountainous island of Grande Terre, the majority of the largest historical flows in the Tontouta River were caused by tropical cyclones and 75% of cyclone‐induced floods were overbank events. Discharge data for the Tontouta River over the period 1969–2003 were used to construct partial duration series (PDS) of daily mean and instantaneous flows. The log Pearson Type III distribution provided a good fit to the PDS. Instantaneous flows are much higher than daily flows, reflecting the flashiness of tropical cyclone hydrographs. This highlights the need to use instantaneous flow data, where available, to investigate flood hazards in steep tropical basins impacted by tropical cyclones.
Effect of ursodeoxycholic acid on serum liver enzymes and bile acid metabolism in chronic active hepatitis C virus infection
Authors: Nojiri Shunsuke , Nakao Haruhisa , Sugauchi Fuminaka , Miyaki Tomokatsu , Senda Katsuhiro , Sasaki Makoto , Kataoka Hiromi , Kamiya Takeshi , Nakazawa Takahiro , Ohara Hirotaka , Orito Etsuro , Joh Takashi
Published: August 2008

Aim:  Many reports have revealed ursodeoxycholic acid (UDCA) to be effective against chronic hepatitis C virus (HCV). However, some cases resist this therapy and the mechanism of action remains unclear. In this study, UDCA was administered to patients with chronic HCV and the correlation between the bile acids of the biliary bile and serum and the drug efficacy was investigated.

Methods:  Fifteen patients were given 600 mg/day of UDCA for more than 24 weeks. The serum bile acid concentrations and biliary and serum bile acid were collected before and after 24 weeks of UDCA treatment, and composition determined by high‐performance liquid chromatography.

Results:  The treatment was effective in nine cases (ALT decreased to less than twice the normal values 80 IU/L) and ineffective in six cases. There was no significant difference in the serum bile acid concentrations before and after UDCA treatment between the values of both cases. After UDCA treatment, the serum percentage of UDCA (effective, 62.5 ± 2.0; ineffective, 53.5 ± 2.5, (P = 0.02)) and the percentage of chenodeoxycholic acid (CDCA) showed no remarkable changes. In the biliary bile the percentage of CDCA (effective, 30.9 ± 2.0; ineffective, 20.0 ± 3.0, (P = 0.007)) and the percentage of UDCA showed no remarkable changes.

Conclusion:  In the effective cases, the percentage of UDCA in the serum and the percentage of CDCA in biliary bile were significantly higher than in the ineffective cases. This indicates that, when effective, CDCA decreases in hepatocytes and this reduction contributes to hepatoprotection.
Heating and Ignition of Metal Particles in the Transition Heat Transfer Regime
Authors: Mohan Salil , Trunov Mikhaylo A. , Dreizin Edward L.
Published: August 2008

This paper considers the heating and ignition of small metallic particles in hot gases for a range of Knudsen numbers, for which the continuum description of heat transfer is not valid. Modified Fuchs’ model for the transition heat transfer analysis was adapted to treat diatomic gas with properties changing as a function of temperature. The dimensionless heat transfer coefficient, Nusselt number, was calculated as a function of the particle diameter for the transition heat transfer regime. Heat transfer rates in the transition regime are somewhat different from one another for the cases of particle heating and cooling while the absolute values of the particle-gas temperature difference are the same. This effect does not exist for the continuum heat transfer model. It is observed that the applicability of the continuum heat transfer model for particles of different sizes depends on pressure and particle-air temperature difference. For example, for particles at 300K heated in air at 2000K, the continuum heat transfer model can be used for particle diameters greater than 10μm and 1μm at the pressures of 1bar and 10bars, respectively. Transition heat transfer model must be used for the analysis of heat transfer for nanosized particles. For calculating the ignition delay, the continuum model remains useful for particle diameters greater than 18μm and 2μm for 1bar and 10bars, respectively. The sensitivity of the transition heat transfer model to the accommodation coefficient is evaluated. It is found that for metallic particles, the accommodation coefficient has a relatively weak effect on the heat transfer rate.
Small and Large Time Solutions for Surface Temperature, Surface Heat Flux, and Energy Input in Transient, One-Dimensional Conduction
Authors: Lavine A. S. , Bergman T. L.
Published: August 2008

This paper addresses one-dimensional transient conduction in simple geometries. It is well known that the transient thermal responses of various objects, or of an infinite medium surrounding such objects, collapse to the same behavior as a semi-infinite solid at small dimensionless time. At large dimensionless time, the temperature reaches a steady state (for a constant surface temperature boundary condition) or increases linearly with time (for a constant heat flux boundary condition). The objectives of this paper are to bring together existing small and large time solutions for transient conduction in simple geometries, put them into forms that will promote their usage, and quantify the errors associated with the approximations. Approximate solutions in the form of simple algebraic expressions are derived (or compiled from existing solutions) for use at both small and large times. In particular, approximate solutions, which are accurate for Fo<0.2 and which bridge the gap between the large Fo (single-term) approximation and the semi-infinite solid solution (valid only at very small Fo), are presented. Solutions are provided for the surface temperature when there is a constant surface heat flux boundary condition, or for the surface heat flux when there is a constant surface temperature boundary condition. These results are provided in terms of a dimensionless heat transfer rate. In addition, the dimensionless energy input is given for the constant surface temperature cases. The approximate expressions may be used with good accuracy over the entire Fourier number range to rapidly estimate important features of the transient thermal response. With the use of the approximations, it is now a trivial matter to calculate the dimensionless heat transfer rate and dimensionless energy input, using simple closed-form expressions.
Measurement of the Thermal Conductivity and Heat Capacity of Freestanding Shape Memory Thin Films Using the 3ω Method
Authors: Jain Ankur , Goodson Kenneth E.
Published: August 2008

An accurate measurement of the thermophysical properties of freestanding thin films is essential for modeling and predicting thermal performance of microsystems. This paper presents a method for simultaneous measurement of in-plane thermal conductivity and heat capacity of freestanding thin films based on the thermal response to a sinusoidal electric current. An analytical model for the temperature response of a freestanding thin film to a sinusoidal heating current passing through a metal heater patterned on top of the thin film is derived. Freestanding thin-film samples of silicon nitride and nickel titanium (NiTi), a shape memory alloy, are microfabricated and characterized. The thermal conductivity of thin-film NiTi, which increases linearly between 243K and 313K, is 40% lower than the bulk value at room temperature. The heat capacity of NiTi also increases linearly with temperature in the low temperature phase and is nearly constant above 280K. The measurement technique developed in this work is expected to contribute to an accurate thermal property measurement of thin-film materials. Thermophysical measurements on NiTi presented in this work are expected to aid in an accurate thermal modeling of microdevices based on the shape memory effect.
Assessing Rotation/Curvature Corrections to Eddy-Viscosity Models in the Calculations of Centrifugal-Compressor Flows
Authors: Dufour G. , Cazalbou J.-B. , Carbonneau X. , Chassaing P.
Published: August 2008

Rotation and curvature (RC) effects on turbulence are expected to impact losses and flow structure in turbomachines. This paper examines two recent eddy-viscosity-model corrections devised to account for these effects: the Spalart and Shur (1997, “On the Sensitization of Turbulence Models to Rotation and Curvature,” Aerosp. Sci. Technol., 1(5), pp. 297–302) correction to the model of Spalart and Allmaras (1994, “A One-Equation Turbulence Model for Aerodynamic Flows,” Rech. Aerosp., 1, pp. 5–21) and the correction of Cazalbou et al. (2005, “Two-Equation Modeling of Turbulent Rotating Flows,” Phys. Fluids., 17, p. 055110) to the (k,ϵ) model. The method of verification and validation is applied to assess the impact of these corrections on the computation of a centrifugal-compressor test case. First, a review of RC effects on turbulence as they apply to centrifugal compressors is made. The two corrected models are then presented. Second, the Radiver open test case (Ziegler K. U., Gallus, H. E., and Niehuis R., 2003, “A Study on Impeller Diffuser Interaction Part 1: Influence on the Performance,” ASME J. Turbomach, 125, pp. 173–182) is used as a basis for the assessment of the two corrections. After a physical-consistency analysis, the Richardson extrapolation is applied to quantify the numerical errors involved in all the calculations. Finally, experimental data are used to perform validation for both global and local predictions. The consistency analysis shows that both corrections lead to significant changes in the turbulent field, in perfect agreement with the underlying theoretical considerations. The uncertainty analysis shows that the predictions of the global performances are more sensitive to grid refinement than they are to RC turbulence modeling. However, the opposite conclusion is drawn with regard to the prediction of some local flow properties: Improvements are obtained with the RC corrections, the best results being observed for the RC-corrected (k,ϵ) model.
Comparison of Two-Dimensional and Three-Dimensional Thermal Models of the LENS® Process
Authors: Yin H. , Wang L. , Felicelli S. D.
Published: August 2008

A new two-dimensional (2D) transient finite element model was developed to study the thermal behavior during the multilayer deposition by the laser engineered net shaping rapid fabrication process. The reliability of the 2D model was evaluated by comparing the results obtained from the 2D model with those computed by a previously developed three-dimensional (3D) model. It is found that the predicted temperature distributions and the cooling rates in the molten pool and its surrounding area agree well with the experiment data available in literature and with the previous results calculated with the 3D model. It is also concluded that, for the geometry analyzed in this study, the 2D model can be used with good accuracy, instead of the computationally much more expensive 3D model, if certain precautions are taken to compensate for the 3D effects of the substrate. In particular, a 2D model could be applied to an in situ calculation of the thermal behavior of the deposited part during the fabrication, allowing dynamic control of the process. The 2D model is also applied to study the effects of substrate size and idle time on the thermal field and size of the molten pool.
Experimental Investigation on the Heat Transfer Between a Heated Microcantilever and a Substrate
Authors: Park Keunhan , Cross Graham L. W. , Zhang Zhuomin M. , King William P.
Published: August 2008

This work describes the heat transfer process from a heated microcantilever to a substrate. A platinum-resistance thermometer with a 140nm width was fabricated on a SiO2-coated silicon substrate. The temperature coefficient of resistance estimated from the measurement was 7×10−4K−1, about one-fifth of the bulk value of platinum. The temperature distribution on the substrate was obtained from the thermometer reading, as the cantilever raster scanned the substrate. Comparison between the measurement and calculation reveals that up to 75% of the cantilever power is directly transferred to the substrate through the air gap. From the force-displacement experiment, the effective tip-specimen contact thermal conductance was estimated to be around 40nW∕K. The findings from this study should help understand the thermal interaction between the heated cantilever and the substrate, which is essential to many nanoscale technologies using heated cantilevers.
Thermal-Boundary-Layer Response to Convected Far-Field Fluid Temperature Changes
Authors: Li Hongwei , Nalim M. Razi
Published: August 2008

Fluid flows of varying temperature occur in heat exchangers, nuclear reactors, nonsteady-flow devices, and combustion engines, among other applications with heat transfer processes that influence energy conversion efficiency. A general numerical method was developed with the capability to predict the transient laminar thermal-boundary-layer response for similar or nonsimilar flow and thermal behaviors. The method was tested for the step change in the far-field flow temperature of a two-dimensional semi-infinite flat plate with steady hydrodynamic boundary layer and constant wall temperature assumptions. Changes in the magnitude and sign of the fluid-wall temperature difference were considered, including flow with no initial temperature difference and built-up thermal boundary layer. The equations for momentum and energy were solved based on the Keller-box finite-difference method. The accuracy of the method was verified by comparing with related transient solutions, the steady-state solution, and by grid independence tests. The existence of a similarity solution is shown for a step change in the far-field temperature and is verified by the computed general solution. Transient heat transfer correlations are presented, which indicate that both magnitude and direction of heat transfer can be significantly different from predictions by quasisteady models commonly used. The deviation is greater and lasts longer for large Prandtl number fluids.
Measurement of Fluid Distributions in a Rotating Fluid Coupling Using High Resolution Gamma Ray Tomography
Authors: Hampel U. , Hoppe D. , Bieberle A. , Kernchen R. , Diele K.-H. , Schleicher E. , da Silva M. J. , Zippe C.
Published: August 2008

Gamma ray tomography has been used to visualize fluid distributions in a rotating fluid coupling in different operation points at a pump speed of 780rpm and lower turbine speeds. The gamma ray computed tomography system comprises a Cs-137 isotopic source and a high resolution gamma ray detector. An angle synchronized tomographic data acquisition technique was applied to produce sharp slice images from different positions along the coupling axis. The data have been used to assess the hydraulic behavior of the fluid coupling and to help improve our understanding of the flow structure development and its implications on torque transfer in such a device.
Hydrofoil Cavitation Under Strong Thermodynamic Effect
Authors: Gustavsson Jonas P. R. , Denning Kyle C. , Segal Corin
Published: August 2008

Cavitation was studied for a NACA0015 hydrofoil using a material that simulates cryogenic behavior. Several angles of attack and flow speeds up to 8.6m∕s were tested. The material used, 2-trifluoromethyl-1,1,1,2,4,4,5,5,5-nonafluoro-3-pentanone, hereafter referred to as fluoroketone, exhibits a strong thermodynamic effect even under ambient conditions. Static pressures were measured at seven chordwise locations along the centerline of the hydrofoil suction side and on the test section wall immediately upstream of the hydrofoil. Frequency analysis of the test section static pressure showed that the amplitude of the oscillations increased as the tunnel speed increased. A gradual transition corresponding to the Type II-I sheet cavitation transition observed in water was found to occur near σ∕2α=5 with Strouhal numbers based on chord dropping from 0.5 to 0.1 as the cavitation number was reduced. Flash-exposure high-speed imaging showed the cavity covering a larger portion of the chord for a given cavitation number than in cold water. The bubbles appeared significantly smaller in the current study and the pressure data showed increasing rather than constant static pressure in the downstream direction in the cavitating region, in line with observations made in literature for other geometries with fluids exhibiting strong thermodynamic effect.
Flows
Between Rotating Cylinders With a Porous Lining
Authors: Subotic M. , Lai F.
C.
Published: August 2008

Flow and temperature fields in an annulus between two rotating cylinders have been examined in this study. While the outer cylinder is stationary, the inner cylinder is rotating with a constant angular speed. A homogeneous and isotropic porous layer is press fit to the inner surface of the outer cylinder. The porous sleeve is saturated with the fluid that fills the annulus. The Brinkman-extended Darcy equations are used to model the flow in the porous layer while the Navier–Stokes equations are used for the fluid layer. The conditions applied at the interface between the porous and fluid layers are the continuity of temperature, heat flux, tangential velocity, and shear stress. Analytical solutions have been attempted. Through these solutions, the effects of Darcy number, Brinkman number, and porous sleeve thickness on the velocity profile and temperature distribution are studied.
Developing Engineering Products Using Inspiration From Nature
Authors: Sarkar Prabir , Phaneendra S. , Chakrabarti Amaresh
Published: August 2008

Nature can be a major source of inspiration for engineering designers. Biomimicry is often used in specific cases to develop solutions that mimic natural systems. However, knowledge of natural systems is still not used systematically and commonly for inspiring innovative product development, from ideation of solutions to their implementation as products. In ideation, potential solutions to a design problem are generated. To support ideation, two databases are developed with entries having information about natural and artificial systems. A novel generic causal model is developed for structuring information of how these systems achieve their behavior. Three algorithms are developed for analogical search of entries that could inspire ideation of solutions to a given problem. In realization, evaluation and modification of these solutions are carried out by experimenting with these in virtual and physical forms and environments.
Performance Study of GasTurbnLab, an Agent-Based Multi-Physics Problem Solving Environment for the Gas Turbine Engine Simulation
Authors: Tsompanopoulou Panagiota E.
Published: August 2008

Multiphysics applications are real world problems with a large number of different shape components that obey different physical laws and manufacturing constraints and interact with each other through geometric and physical interfaces. They demand accurate and efficient solutions and a modern type of computational modeling, which designs the whole physical system with as much detail as possible. The simulation of gas turbine engine is such a multiphysics application and is realized with GasTurbnLab, an agent-based Multiphysics Problem Solving Environment (MPSE). Its performance and evaluation study is presented in this paper. For this, a short description of the software components and hardware infrastructure is given. The performance and the scalability of the parallelism are depicted, and the communication overhead between agents is studied with respect to the number of agents and their location in the “computational grid.” The execution time is recorded, and its analysis verifies the complexity of the solvers in use and the performance of the available hardware. Three different clusters of INTEL Pentium processors were used for experimentation to study how the communication time was affected by processor’s homogeneity/heterogeneity and the different connections between the processors. The study of the numerical experiments shows that the domain decomposition and interface relaxation methodology, along with the usage of agent platforms, does not increase the complexity of the simulation problem, and the communication cost is too low, compared with the computations, to reflect on the total simulation time. Therefore, GasTurbnLab is an efficient example of a complex physical phenomena simulation.
Three-Dimensional Finite Element Analysis of Pipe Flange Connections: The Case of Using Compressed Asbestos Sheet Gasket
Authors: Takaki Tomohiro , Fukuoka Toshimichi
Published: August 2008

The most important factor for the leakage problem of pipe flange connections is considered to be contact pressure distribution at the gasket bearing surface in service. In this study, the mechanical behaviors of the pipe flange connection are evaluated using FEM as a three-dimensional contact problem, in which a gasket is modeled as a nonlinear one-dimensional gasket element. Here, the contact pressure distributions at the gasket bearing surface and the variations of the bolt stress are estimated under uniform bolt preloads or nonuniform ones due to the elastic interaction during bolting up. The numerical procedure proposed here can successively deal with the processes of bolt-up, applying inner pressure and applying bending moment. The analytical objects are pipe flanges specified in JIS B 2238 with compressed asbestos sheet gaskets being inserted. The validity of the numerical method is ascertained by experiment.
Analysis of Residual Stresses and Assessment of Postulated Cracks in a Core Shroud Weld
Authors: Varfolomeyev Igor , Siegele Dieter , Beukelmann Dieter
Published: August 2008

In order to assess postulated cracks in weldments of a BWR core shroud residual stresses are calculated by simulating the welding process. In the numerical analysis, weld metal deposition and the sequence of weld passes follow the manufacture protocol. The calculations are performed using the finite element program ABAQUS and a material model with kinematic nonlinear hardening. Calculations of the crack driving parameter, the stress intensity factor, are carried out for postulated circumferential cracks using a numerical procedure, as well as by applying a weight function solution specially developed for cracks in a thin-walled cylinder. The results give rise to a discussion on the validity of linear elastic fracture mechanics for assessing defects in weldments. Additionally, for a complete circumferential crack the trend in the stress intensity factor is studied when the crack depth approaches the full wall thickness.
The Effect of Residual Stresses on the Fracture Resistance of Ductile Steels
Authors: O’Dowd Noel P. , Lei Yuebao
Published: August 2008

Tensile residual stresses, such as those generated by welding, act as crack opening stresses and can have a negative effect on the fatigue and fracture performance of a component. In this work the effect of representative residual stress distributions on the fracture behaviour of a ferritic steel has been examined using finite element analysis. A Gurson-type void growth model is used to model the effect of ductile tearing ahead of a crack. For the cases examined it is seen that a tensile residual stress field may lead to a reduction in the toughness of the material (as represented by the J-resistance curve). The observed difference in toughness can be linked to the different constraint levels in the specimens due to the introduction of the residual stress field and can be rationalised through the use of a two parameter, J–Q approach.
Measurement of Pressure Drop in Inclined Triangular and Rotated Triangular Tube Bundles
Authors: Choi Seok-Ki , Choi Il Kon , Lee Kil Yong , Nam Ho Yun , Choi Jong Hyeun , Choi Hoon Ki
Published: August 2008

The present paper presents the experimental results for pressure drop in inclined tube bundles located in a rectangular duct. Measurements are made for pressure drop in triangular and rotated triangular tube arrays having P/d ratio of 1.6 and inclination angles of 30, 45, 60 and 90 degrees. The Reynolds number based on the free stream velocity and tube diameter ranges from 8×102 to 6.3×104. The experimental results show that the magnitude of dimensionless pressure drop decreases significantly when the inclined angle is less than 45 degree. The measured data are compared with two existing correlations available in the literatures. The ESDU correlation agrees well with the present data for the triangular arrays. But some discrepancies are observed for the rotated triangular arrays when the inclined angles are 30 and 45 degrees. The Idel’chik correlation generally agrees well with the measured data for the rotated triangular arrays except for the inclined angle of 30 degree. The Idel’chik correlation needs modification for the triangular arrays. The modified Idel’chik correlation agrees well with the measured data within 10%. It is found that the present measured data can be applied to the evaluation and modification of previous correlations.