bluuebunny/crossref_metadata_2025 huggingface dataset:
Where's the beef? A response to Gray and Webb's ‘The return of the political in social work’
Authors: Ferguson Iain
Published: March 2009

Gray and Webb's article ‘The return of the political in social work’ is a welcome contribution to current debates. In its critique of the dominance of calculative reason, its rejection of postmodernism and identity politics, and its insistence on the need for social work to openly address issues of power and conflict, it is a useful addition to the growing critical literature concerned with challenging dominant forms of practice. That usefulness is limited, however, first by an excessively opaque style and, second, by problems associated with the writers’ argument and approach. These include: an over‐reliance on Heidegger's ontology; an over‐estimation of the potential of art to act as alternative paradigm; and a particularly content‐less version of politics, derived from the work of Alain Badiou, which is likely to prove to be of limited value in the project of developing alternative forms of social work.
Size, Conflict, and Opportunities for Interaction: Congregational Effects on Members' Anticipated Support and Negative Interaction
Authors: Ellison Christopher G. , Krause Neal M. , Shepherd Bryan C. , Chaves Mark A.
Published: March 2009

A growing literature examines the role of religious communities as sources of social support for members, and a smaller body of work also explores negative aspects of social relations within congregations. However, very little is known about the characteristics of religious groups that promote or impede the development of supportive networks. We use data from a unique source—the National Congregations Study, linked with individual records from the 1998 General Social Survey (GSS)—to explore this issue. Key findings reveal that: (1) individuals who attend very large churches tend to report lower levels of anticipated support and informal negative interaction; (2) the presence of major congregational conflict tends to dampen anticipated support and increase informal negative interaction; and (3) the absence of a well‐defined period for informal socializing before or after the worship service is associated with lower levels of anticipated support, but is unrelated to the frequency of negative interaction among church members. Several implications and promising directions for future research are discussed.
The Unmaking of Prejudice: How Christian Beliefs Relate to Attitudes Toward Homosexuals
Authors: Ford Thomas E. , Brignall Thomas , VanValey Thomas L. , Macaluso Michael J.
Published: March 2009

We propose that the internalization of orthodox Christian beliefs serves as a basis for a personal moral standard that discourages prejudice against others as well as for self‐critical emotions that follow upon behaving in a discriminatory manner. Two correlational studies tested hypotheses derived from our theory. Study 1 demonstrated that to the extent people endorse orthodox Christian beliefs, they report an internal motivation to respond without prejudice toward homosexuals. Study 2 demonstrated that, when controlling for the effects of right‐wing authoritarianism (RWA), endorsement of orthodox Christian beliefs was related to positive attitudes toward homosexuals as individuals or as a group, but not toward homosexuality as a behavior or lifestyle.
Expression of epidermal growth factor receptor and vascular endothelial growth factor in malignant canine epithelial nasal tumours*
Authors: Shiomitsu K. , Johnson C. L. , Malarkey D. E. , Pruitt A. F. , Thrall D. E.
Published: March 2009

Epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) signalling pathways play a role in carcinogenesis. Inhibition of EGF receptor (EGFR) and of VEGF is effective in increasing the radiation responsiveness of neoplastic cells both in vitro and in human trials. In this study, immunohistochemical evaluation was employed to determine and characterize the potential protein expression levels and patterns of EGFR and VEGF in a variety of canine malignant epithelial nasal tumours. Of 24 malignant canine nasal tumours, 13 (54.2%) were positive for EGFR staining and 22 (91.7%) were positive for VEGF staining. The intensity and percentage of immunohistochemically positive neoplastic cells for EGFR varied. These findings indicate that EGFR and VEGF proteins were present in some malignant epithelial nasal tumours in the dogs, and therefore, it may be beneficial to treat canine patients with tumours that overexpress EGFR and VEGF with specific inhibitors in conjunction with radiation.
Factors Associated with Succession of Abandoned Agricultural Lands along the Lower Missouri River, U.S.A.
Authors: Thogmartin Wayne E. , Gallagher Maureen , Young Neal , Rohweder Jason J. , Knutson Melinda G.
Published: March 2009

The 1993 flood of the Missouri River led to the abandonment of agriculture on considerable land in the floodplain. This abandonment led to a restoration opportunity for the U.S. Federal Government, purchasing those lands being sold by farmers. Restoration of this floodplain is complicated, however, by an imperfect understanding of its past environmental and vegetative conditions. We examined environmental conditions associated with the current placement of young forests and wet prairies as a guide to the potential successional trajectory for abandoned agricultural land subject to flooding. We used Bayesian mixed‐effects logistic regression to examine the effects of flood frequency, soil drainage, distance from the main channel, and elevation on whether a site was in wet prairie or in forest. Study site was included as a random effect, controlling for site‐specific differences not measured in our study. We found, after controlling for the effect of site, that early‐successional forest sites were closer to the river and at a lower elevation but occurred on drier soils than wet prairie. In a regulated river such as the lower Missouri River, wet prairie sites are relatively isolated from the main channel compared to early‐successional forest, despite occurring on relatively moister soils. The modeled results from this study may be used to predict the potential successional fate of the acquired agricultural lands, and along with information on wildlife assemblages associated with wet prairie and forest can be used to predict potential benefit of these acquisitions to wildlife conservation.
Possible Mechanism for Spontaneous Establishment of Calluna vulgaris in a Recently Abandoned Agricultural Field
Authors: Van Der Wal Annemieke , De Boer Wietse , Klein Gunnewiek Paulien J. A. , Van Veen Johannes A.
Published: March 2009

In Western Europe, arable lands have been abandoned to increase the area of nature, such as Calluna vulgaris–dominated heathlands. However, the growth conditions, e.g., nutrient availability and lack of a phenolics‐rich organic layer, on ex‐arable sandy soils differ markedly from those of heathland and will favor fast‐growing plant species. Succession toward Calluna‐dominated heathland is expected to take decades unless intensive restoration management is applied. Here, we report a possible mechanism to explain the occurrence of Calluna patches (0.7–2.0 m diameter) in a 10‐year abandoned agricultural field within a dominant vegetation of grasses and forbs. All roots sampled from the Calluna patches were colonized by ericoid mycorrhizal (ERM) and other endomycorrhizal fungi. Both nitrogen mineralization of soil organic N and potential nitrogen mineralization (arginine ammonification) were much lower in soil under Calluna patches than in the rest of the ex‐arable soil, although other soil characteristics did not differ. The nitrogen to phosphorus ratio in Calluna shoots was much greater than that in shoots of grasses and forbs, indicating that the latter were more N limited. The results indicate that the association with ERM fungi is probably providing the host competitive superiority for nitrogen even in a soil with low organic matter content. Our results suggest that the conversion from arable land into heathland may be accomplished by the immediate establishment of Calluna seedlings and ERM inoculum when agricultural activities are stopped. This needs to be tested in controlled experiments.
Soil Organism and Plant Introductions in Restoration of Species‐Rich Grassland Communities
Authors: Kardol Paul , Bezemer T. Martijn , Van Der Putten Wim H.
Published: March 2009

Soil organisms can strongly affect competitive interactions and successional replacements of grassland plant species. However, introduction of whole soil communities as management strategy in grassland restoration has received little experimental testing. In a 5‐year field experiment at a topsoil‐removed ex‐arable site (receptor site), we tested effects of (1) spreading hay and soil, independently or combined, and (2) transplanting intact turfs on plant and soil nematode community development. Material for the treatments was obtained from later successional, species‐rich grassland (donor site). Spreading hay affected plant community composition, whereas spreading soil did not have additional effects. Plant species composition of transplanted turfs became less similar to that in the donor site. Moreover, most plants did not expand into the receiving plots. Soil spreading and turf transplantation did not affect soil nematode community composition. Unfavorable soil conditions (e.g., low organic matter content and seasonal fluctuations in water level) at the receptor site may have limited plant and nematode survival in the turfs and may have precluded successful establishment outside the turfs. We conclude that introduction of later successional soil organisms into a topsoil‐removed soil did not facilitate the establishment of later successional plants, probably because of the “mismatch” in abiotic soil conditions between the donor and the receptor site. Further research should focus on the required conditions for establishment of soil organisms at restoration sites in order to make use of their contribution to grassland restoration. We propose that introduction of organisms from “intermediate” stages will be more effective as management strategy than introduction of organisms from “target” stages.
WHO comparative evaluation of serologic assays for Chagas disease
Authors: Otani Marcia M. , Vinelli Elizabeth , Kirchhoff Louis V. , Del Pozo Ana , Sands Anita , Vercauteren Gaby , Sabino Ester C.
Published: March 2009

BACKGROUND: Evaluation of commercially available test kits for Chagas disease for use in blood bank screening is difficult due to a lack of large and well‐characterized specimen panels. This study presents a collaborative effort of Latin American blood centers and the World Health Organization (WHO) to establish such a panel.

STUDY DESIGN: A total of 437 specimens, from 10 countries were collected and sent to the WHO Collaborating Center in São Paulo and used to evaluate 19 screening assays during 2001 through 2005. Specimens were assigned a positive or negative status based on concordant results in at least three of the four confirmatory assays (indirect immunofluorescence, Western blot, radioimmunoprecipitation assay, and recombinant immunoblot).

RESULTS: Of the 437 specimens, 168 (39%) were characterized as positive, 262 (61%) were characterized as negative, and 7 (2%) were judged inconclusive and excluded from the analysis. Sensitivity and specificity varied considerably: 88 to 100 and 60 to 100 percent, respectively. Overall, enzyme immunoassays (EIAs) performed better than the other screening assays. Four EIAs had both parameters higher than 99 percent. Of the four confirmatory assays, only the RIPA gave a 100 percent agreement with the final serologic status of the specimens.

CONCLUSION: The sensitivities and specificities of at least four of the commercially available EIAs for Chagas disease are probably high enough to justify their use for single‐assay screening of blood donations. Our data suggest that the majority of commercially available indirect hemagglutination assays should not be used for blood donor screening and that the RIPA could be considered a gold standard for evaluating the performance of other assays.
The Life, Works and Reception of an Evangelical Radical: James Woodhouse (1735–1820), the ‘Poetical Shoemaker’
Authors: Van‐Hagen Steve
Published: March 2009

The article surveys the life, career, reception and works of James Woodhouse, ‘The Poetical Shoemaker’, making use of a wide variety of sources. The article outlines his posthumous reputation, arguing that many accounts until recently seem to have perpetuated the same (sometimes misleading) impressions of Woodhouse and his work. It is suggested, however, that more nuanced critical approaches to Woodhouse's oeuvre, emphasising his significance to the labouring‐class poetic tradition, have emerged in recent years. The article surveys new directions for future scholarship, concentrating on the construction of identities in Woodhouse's posthumously‐published verse autobiography, The Life and Lucubrations of Crispinus Scriblerus. The poem charts the growth of Woodhouse/Crispin(us)'s radical evangelical Methodist identity in his later years, as he retreats from an early quiescence with patrons that saw all but one poem in his first published collection dedicated to them. The article argues that contemporary critical approaches can account for why and how the autobiographical act of Crispinus Scriblerus embodies the complexities of Woodhouse's multiple and contradictory simultaneous identities. Crispinus Scriblerus uses the philosophy of Heraclitus to reproduce the same strategy that Woodhouse accuses the educated classes of adopting towards him during his early years of poetic celebrity: that of claiming superiority on the grounds of absolute difference between his own identity and that of his antagonists. It is argued that paying critical attention to the fluidity of the seeming autobiographical oppositions that the critic Stuart Sherman terms ‘compound rubrics’ can demonstrate how the poem (sometimes unwittingly) realises some of its aims, while failing in others.
Dynamics of knowledge creation and transfer: The two person case
Authors: Berliant Marcus , Fujita Masahisa
Published: March 2009

This paper presents a micro‐model of knowledge creation and transfer for a couple. Heterogeneity of people in their state of knowledge is essential for successful cooperation in the joint creation of new ideas. However, the very process of cooperative knowledge creation affects the heterogeneity of people through the accumulation of knowledge in common. The model features myopic agents in a pure externality model of interaction. The equilibrium process tends to result in the accumulation of too much knowledge in common compared to the most productive state. Equilibrium paths are found analytically, and they are a discontinuous function of initial heterogeneity.
Antinociceptive Properties of the Hydroalcoholic Extract and the Flavonoid Rutin Obtained fromPolygala paniculataL. in Mice
Authors: Lapa Fernanda da R. , Gadotti Vinicius M. , Missau Fabiana C. , Pizzolatti Moacir G. , Marques Maria Consuelo A. , Dafré Alcir L. , Farina Marcelo , Rodrigues Ana Lúcia S. , Santos Adair R. S.
Published: March 2009

Abstract:  The present study examined the antinociceptive effects of a hydroalcoholic extract ofPolygala paniculatain chemical and thermal behavioural models of pain in mice. The antinociceptive effects of hydroalcoholic extract was evaluated in chemical (acetic‐acid, formalin, capsaicin, cinnamaldehyde and glutamate tests) and thermal (tail‐flick and hot‐plate test) models of pain or by biting behaviour following intratecal administration of both ionotropic and metabotropic agonists of excitatory amino acids receptors glutamate and cytokines such as interleukin‐1β (IL‐1β) and tumour necrosis factor‐α (TNF‐α) in mice. When given orally, hydroalcoholic extract (0.001–10 mg/kg), produced potent and dose‐dependent inhibition of acetic acid‐induced visceral pain. In the formalin test, the hydroalcoholic extract (0.0001–0.1 mg/kg orally) also caused significant inhibition of both the early (neurogenic pain) and the late (inflammatory pain) phases of formalin‐induced licking. However, it was more potent and efficacious in relation to the late phase of the formalin test. The capsaicin‐induced nociception was also reduced at a dose of only 1.0 mg/kg orally. The hydroalcoholic extract significantly reduced the cinnamaldehyde‐induced nociception at doses of 0.01, 0.1 and 1.0 mg/kg orally. Moreover, the hydroalcoholic extract (0.001–1.0 mg/kg orally) caused significant and dose‐dependent inhibition of glutamate‐induced pain. However, only rutin, but not phebalosin or aurapten, isolated fromP. paniculata, administered intraperitoneally to mice, produced dose‐related inhibition of glutamate‐induced pain. Furthermore, the hydroalcoholic extract (0.1–100 mg/kg orally) had no effect in the tail‐flick test. On the other hand, the hydroalcoholic extract caused a significant increase in the latency to response at a dose of 10 mg/kg orally, in the hot‐plate test. The hydroalcoholic extract (0.1 mg/kg orally) antinociception, in the glutamate test, was neither affected by intraperitoenal treatment of animals withl‐arginine (precursor of nitric oxide, 600 mg/kg) and naloxone (opioid receptor antagonist, 1 mg/kg.) nor associated with non‐specific effects such as muscle relaxation or sedation. In addition, oral administration of hydroalcoholic extract produced a great inhibition of the pain‐related behaviours induced by intrathecal injection of glutamate,N‐methyl‐d‐aspartate (NMDA), IL‐1β and TNF‐α, but not by α‐amino‐3‐hydroxy‐5‐methyl‐isoxazole‐4‐propionic acid (AMPA), kainate or trans‐1‐amino‐1.3‐cyclopentanediocarboxylic acid (trans‐ACPD). Together, our results suggest that inhibition of glutamatergic ionotropic receptors, may account for the antinociceptive action reported for the hydroalcoholic extract fromP. paniculatain models of chemical pain used in this study.
The Hypoalgesic Effect of Oxycodone in Human Experimental Pain Models in Relation to the CYP2D6 Oxidation Polymorphism
Authors: Zwisler Stine T. , Enggaard Thomas P. , Noehr‐Jensen Lene , Pedersen Rasmus S. , Mikkelsen Soeren , Nielsen Flemming , Brosen Kim , Sindrup Soeren H.
Published: March 2009

Abstract: Oxycodone is O‐demethylated by CYP2D6 to oxymorphone which is a potent µ‐receptor agonist. The CYP2D6 oxidation polymorphism divides the Caucasian population in two phenotypes: Approximately 8% with no enzyme activity, poor metabolizers (PM) and the remainder with preserved CYP2D6 activity, extensive metabolizers (EM). The objective of the study was to determine if the analgesic effect of oxycodone in human experimental pain depends on its metabolism to oxymorphone. The analgesic effect of oxycodone was evaluated in a randomized, placebo‐controlled, double‐blinded, crossover experiment including 33 (16 EM and 17 PM) healthy volunteers. Pain tests were performed before and 1, 2, 3 and 4 hr after medication and included pain detection and tolerance thresholds to single electrical sural nerve stimulation, pain summation threshold to repetitive electrical sural nerve stimulation and the cold pressor test with rating of discomfort and pain‐time area under curve (AUC0–2 min.). For single sural nerve stimulation, there was a less pronounced increase in thresholds on oxycodone in pain detection (9% vs. 20%, P = 0.02, a difference of 11%, CI: 2%–20%) and pain tolerance thresholds (15% vs. 26%, P = 0.037, a difference of 10%, CI: 1%–20%) for PM compared with EM. In the cold pressor test, there was less reduction in pain AUC on oxycodone for PM compared with EM (14% vs. 26%, P = 0.012, a difference of 12%, CI: 3%–22%). The plasma oxymorphone/oxycodone ratio was significantly lower in PM compared with EM (P < 0.001). Oxycodone analgesia seems to depend both on oxycodone itself and its metabolite oxymorphone.
Comparison of IL10 and IL2 genotypes of Turkish population with other populations
Authors: Yazıcı A. C. , Atac F. B. , Verdi H. , Ozbek N.
Published: March 2009

The human genome has been shaped by evolutionary and historical forces. Therefore, genetic polymorphisms are useful tools not only to understand the susceptibility to disease in modern populations, but the history of ancestral populations as well. For this purpose, data on genetic polymorphisms such as human leucocyte antigen, mitochondrial DNA sequence variability and the frequencies of TAP1 and TAP2 gene variants in Turkey have been reported previously. Here we have used interleukin (IL)‐10 (−592C/A, −819T/C, −1082G/A) and IL‐2 (−330T/G) as genetic markers to study the relationship between Turkish population and other populations.
Cultivation and ensilage of yacon plants (Smallanthus sonchifolius [Poepp. & Endl.] H. Robinson) and the function of yacon silage
Authors: Koike Akiko , Murata Tatsuro , Matsuda Yasushi , Masuoka Chikako , Okamoto Chinobu , Kabata Kiyotaka
Published: March 2009

Yacon (Smallanthus sonchifolius [Poepp. & Endl.] H. Robinson) plant cultivation has extended rapidly throughout Japan since 1985 because of its utility as a tuberous root crop. In this study, strains with high yields of both above‐ground and underground parts were identified to investigate the use of above‐ground parts for animal feed silage. In addition, we measured the anti‐oxidative activity of the silage as a functional characteristic. Data from 5 years of the cultivation of 17 yacon strains suggest that the most suitable strain for planting in the Aso region of Japan is SY217, which has a high yield of both above‐ground parts and tuberous roots. The root tuber parts of yacon are used almost entirely as food; actually, most foliage parts are hardly used, except for some above‐ground parts, which are used as tea. The fermentation qualities of the silage using all above‐ground parts and harvest residue tuberous roots (harvest residues) are high and their dry matter digestibility, investigated using pigs, is 66.7%. Fresh above‐ground parts had very strong anti‐oxidative activity as compared with butylated hydroxyanisole and α‐tocopherol. In addition, that activity is retained during ensiling for 4 weeks. These results suggest that the entire yacon plant can be used effectively as a feedstuff resource with the added bonus of anti‐oxidant activity.
Magnetic field variations and seismicity of solar active regions
Authors: Martínez-Oliveros J. C. , Donea A.-C.
Published: March 2009

Dynamical changes in the solar corona have proven to be very important in inducing seismic waves into the photosphere. Different mechanisms for their generation have been proposed. In this work, we explore the magnetic field forces as plausible mechanisms to generate sunquakes as proposed by Hudson, Fisher & Welsch. We present a spatial and temporal analysis of the line-of-sight magnetic field variations induced by the seismically active 2003 October 29 and 2005 January 15 solar flares and compare these results with other supporting observations.
African Islam: Marriage, Mobility and Education of Women in Dan Fodio's nineteenth Century Reforms
Authors: Ibrahim Mohammed Zakyi
Published: March 2009

In 1804 ce, Dan Fodio toppled the chiefs of northern Nigeria for their ‘un‐Islamic’ behaviors, and established an Islamic state on the Hausa/Fulani land. This phase in the history of Islam in Africa has been widely described and accepted as ‘militant’ and the scholars involved ‘intolerant’. Dan Fodio's own reputation as a ‘militant’ scholar has been popularly suggested, and his conservative stance on many issues was well‐documented. It is therefore intriguing that Dan Fodio had some social temperaments that challenged this conservative outlook. Specifically, this study is a sociological analysis of Dan Fodio's opinions on marriage, movement or mobility of women, and their education. This study is significant for analyzing these social issues and their implications, as well as suggesting that, in addition to the highly acclaimed militant stance, Dan Fodio was also a pragmatic and realistic scholar who was ready to make religious concessions in favor of some social imperatives.
Isolation of 21 polymorphic microsatellite markers for the Virginia opossum (Didelphis virginiana)
Authors: FIKE JENNIFER A. , BEASLEY JAMES C. , RHODES, JR OLIN E.
Published: March 2009

Twenty‐one polymorphic microsatellite markers were developed for the Virginia opossum (Didelphis virginiana). The number of alleles ranged from two to 13 and observed heterozygosities ranged from 0.464 to 0.964. Significant heterozygote deficiencies were observed at three loci and null alleles were detected at five loci. Evidence for gametic disequilibrium was observed between three sets of paired loci after a sequential Bonferroni correction was applied. These markers will enable us to investigate the mating tactics, movement behaviour and social structure of Virginia opossum populations inhabiting fragmented agricultural landscapes.
Dynamics of Closed Circuit Hydraulic Model Loops
Authors: Svingen Bjo̸rnar , Kjeldsen Morten , Arndt Roger E. A.
Published: March 2009

This paper reviews the issue of making unsteady measurements involving cavitating flow in traditional test loops. Measurements of the dynamic response of a water tunnel during testing of a partially cavitating hydrofoil are presented and reviewed in the context of current theory. Data were collected from an array of pressure transducers that were distributed around the tunnel loop. In the post processing of these data, gain and phase response data were calculated. Theoretical analysis consisted of splitting the system into different elements, and included the compressibility of water in the physics used to describe each element. While solving the global system an eigenvalue solution was found, thus no node specific solution is obtained. This work is currently being extended with the aim of obtaining node specific values such that a more direct comparison between the experimental and theoretical work can be made.
Two-Phase Flow and Inertial Effects on the Rotordynamic Forces in Whirling Journal Bearings
Authors: Rapposelli Emilio , Falorni Roberto , d’Agostino Luca
Published: March 2009

This paper presents the application of the isenthalpic two-phase flow approximation (Brennen, 1995) to the study of cavitation and ventilation effects in plane journal bearings with whirling eccentricity. A quasi-homogeneous bubbly liquid/vapor model, suitably modified to account for thermal effects (Rapposelli and d’Agostino, 2001), is used to describe the occurrence of flow cavitation. An homogeneous liquid/gas/vapor model without thermal effects is used to describe the simultaneous occurrence of cavitation and ventilation. The proposed model treats the fully-wetted and two-phase portions of the fluid in a unified manner in order to avoid the use of “ad hoc” matching conditions, whose applicability and accuracy is questionable in the presence of significant inertial and/or unsteady effects. A non-linear analysis that accounts for the inertia of the lubricant is used to determine the reaction forces caused by the shaft’s eccentric motion both in the viscosity-dominated regime and at intermediate values of the Reynolds number, where the inertia of the lubricant is no longer negligible. The classical iteration method for the Reynolds lubrication equation (Muster and Sternlicht, 1965; Mori and Mori, 1991; Reinhardt and Lund, 1975) has been extended to the unsteady two-phase flow case in order to account for flow acceleration effects in the presence of cavitation and/or ventilation. Significant deviations from the steady-state case are obtained at moderately high Reynolds numbers (Re = ωRc/νL ≅ 10). Comparisons with the scant experimental data support the validity of the proposed model. Results are shown in a number of representative cases in order to illustrate the influence of the relevant parameters.
A Numerical Study of Thermodynamic Effects of Sheet Cavitation
Authors: Tokumasu Takashi , Kamijo Kenjiro , Matsumoto Yoichiro
Published: March 2009

In cryogenic fluids such as LH2 or LOX, temperature depression of liquids due to latent heat of vaporization suppresses the growth of cavitation, which is called “thermodynamic effects of cavitation.” Thermodynamic effects of cavitation are significant in these fluids, because they are generally operated close to the critical point and are also characterized by a strong dependence of vapor pressure on temperature. Owing to this phenomenon, the performance of the rocket pump, inducer and other hydraulic equipment is sustained. In this paper, the thermodynamic effects of cavitation are investigated numerically. To predict these effects, a cavitation model introduced by Deshpande et al. is improved. Using this model a sheet cavity around a 2-D hydrofoil is simulated and the dependence of the properties of fluids or Reynolds number on the thermodynamic effects of cavitation is analyzed. The numerical results explain the thermodynamic effects well.
Bubble Tracking Simulation of Cavitating Flow in an Atomization Nozzle
Authors: Sou Akira , Nitta Shinichi , Nakajima Tsuyoshi
Published: March 2009

Numerical simulation of transient cavitating flow in a axisymmetric nozzle was conducted in order to investigate the detailed motion of cavitation bubble clouds which may be dominant to atomization of a liquid jet. Two-way coupled bubble tracking technique was assigned in the present study to predict the unsteady cloud cavitation phenomena. Large Eddy Simulation (LES) was used to predict turbulent flow. Calculated pressure distribution and injection pressure were compared with measured ones. Then, calculated motion of cavitation bubble clouds was carefully investigated to understand the cavitation phenomena in a nozzle. As a result, the following conclusions were obtained: (1) Calculated result of pressure distribution along the wall, the relation between injection pressure vs. flow rate, and bubble distribution agreed with existing experimental result. (2) Cavitation bubble clouds were periodically shed from the tail of vena contracta, which usually formed by the coalescence of a few small bubble clouds. (3) Collapse of cavitation bubbles due to the re-entrant jet was observed in the numerical simulation.
Control of an Incompressible Turbulent Flow Past a Circular Cylinder Computed by Large Eddy Simulation
Authors: Fournier Guillaume , Pellerin Ste´phanie , Ta Phuoc Loc
Published: March 2009

Large Eddy Simulations are performed on a turbulent flow past a circular cylinder with control using velocity-vorticity formulation. The effect of two control methods is analyzed considering aerodynamic coefficients. The influence of rotation and suction velocities is studied. The cylinder rotation and the boundary layer suction induce a lift creation and an increase of lift with control magnitude. Lift value also depends strongly on the suction location which has to be in the vicinity of the separation point.
Model Reduction by Proper Orthogonal Decomposition Coupled With Centroidal Voronoi Tessellations (Keynote)
Authors: Du Qiang , Gunzburger Max
Published: March 2009

Proper orthogonal decompositions (POD) have been used to define reduced bases for low-dimensional approximations of complex systems, including turbulent flows. Centroidal Voronoi tessellations (CVT) have been used in a variety of data compression and clustering settings. We review both strategies in the context of model reduction for complex systems and propose combining the ideas of CVT and POD into a hybrid method that inherets favorable characteristics from both its parents. The usefulness of such an approach and various practical implementation strategies are discussed.
On the Search for Fundamental Performance Limitations in Fluid-Mechanical Systems
Authors: Bewley Thomas R. , Aamo Ole Morten
Published: March 2009

A simple pressure-based feedback control strategy for wall-transpiration control of incompressible unsteady 2D channel flow was recently investigated by Aamo, Krstic, & Bewley (2001). Nonlinear 2D channel flow simulations which implemented this control strategy resulted in flow transients with instantaneous drag far lower than that of the corresponding laminar flow. The present note examines the physical mechanism by which this very low level of instantaneous drag was attained. It then explores the possibility of achieving sustained drag reductions to below the laminar level by initiating such low-drag transients on a periodic basis. All attempts at sustaining the mean flow drag below the laminar level fail, providing further evidence in favor of the conjecture that the laminar state provides a fundamental “performance limitation” in such flows.
Pitfalls of Hot-Wire Measurements Due to Transverse Wire Vibration
Authors: Anderson Chris S. , Turan O¨zden F. , Semercigil S. Eren
Published: March 2009

Following from numerical predictions and large scale experimental verification, flow measurements are presented to show the effect of transverse wire vibrations on spectral measurements. It has been shown previously that if the first and second natural frequencies of a probe wire are close, it is expected to have favorable dynamic characteristics in turbulent flow. This expectation is confirmed with flow measurements. Further, the traditional sensing length to diameter ratio is reexamined for small scale measurements.
Near-Wall Measurements in Turbulent Boundary Layers Using Laser Doppler Anemometry
Authors: Johansson T. Gunnar , Castillo Luciano
Published: March 2009

Near wall measurements have been performed in a zero pressure gradient turbulent boundary layer at low to moderate local Reynolds numbers using Laser-Doppler Anemometry in order to investigate how accurately the wall shear stress can be determined. Also, scaling problems are particularly difficult at low Reynolds numbers since they involve simultaneous influences of both inner and outer scales and this is most clearly observed in the near-wall region. In order to fully describe the zero pressure gradient turbulent boundary layer at low to moderate local Reynolds numbers it is necessary to accurately measure a number of quantities. These include the mean velocity and Reynolds stresses, and their spatial derivatives all the way down to the wall (y+∼1). Integral parameters that need to be measured are the wall shear stress and boundary layer thickness, particularly the momentum thickness. Problems with the measurement of field properties get worse close to a wall, and they get worse for increasing local Reynolds number. Three different approaches to measure the wall shear stress were examined. It was found that small measurement errors in the mean velocity close to the wall significantly reduced the accuracy in determining the wall shear stress by measuring the velocity gradient at the wall. The constant stress layer was found to be affected by the advection terms. However, it was found that taking the small pressure gradient into account and improving on the spatial resolution in the outer part of the boundary layer made the momentum integral method reliable.
A Study of Hydrodynamic Characteristics of Boundary Layer With Algae Roughness
Authors: Subramanian Chekakara S. , Shinjo Nagahiko , Gangadharan Sathya N.
Published: March 2009

Filamentous algae fouling such as Enteromorpha clathrata is a soft and hairy-like substance that can protrude even through a normal boundary layer. Typically, such fouling has been treated as traditional roughness functions to yield hydrodynamic characteristics [1]. This technique has been successfully used for thin fouling layer. However it may not be applicable on thicker layer since present study found substantial fluid flow within the layer. For such cases, the roughness cannot be treated simply as a passive geometric variable, but its kinematics and interactions with the flow have to be considered. The inner law (log law) dynamics may be abnormal to yield any meaningful roughness function if it is calculated in the traditional way as the departure of rough-wall log law profile over a smooth-wall log law profile. Moreover, measurement of velocity profile using LDV within the roughness is ambiguous because of the beam interference. In the present research velocity measurement of the Enteromorpha roughness boundary layer using pitot-static tube and laser Doppler velocimeter (LDV) were compared. Large discrepancies in the velocity profiles within and in the vicinity of the roughness layer were observed between the two methods. The pitot-static tube data showed significantly high velocities (60%–80% of the freestream) in the inner layer. On the other hand, LDV velocity measurements near and within the roughness layer was not reliable due to obstruction of the probe volume by the Enteromorpha filaments. The lack of good near wall data points led to inconsistencies in estimating the fluid dynamic characteristics such as skin friction coefficient and wall shear stress. Above the roughness, the pitot-static tube and LDV profiles showed relatively good agreement.
Experimental Study of Aerodynamics Around Rotating Blades in a Lawnmower Deck
Authors: Hagen P. A. , Chon W. , Amano R. S.
Published: March 2009

The objective of this study is to investigate the flow behavior within a triple-blade lawnmower deck by means of experimental techniques. The test section was constructed for velocity measurement with an open bottom and side-discharge. Velocity measurements were collected at several different tangential and axial sections inside the deck. The flow behaviors are observed using both a Laser Doppler Velocimetry (LDV) and a high-speed video camera capturing 2000 frames per second. Several different visualization techniques have been attempted: particle feeding, water vapor injection, tuft method, and others. To further enhance the experimental accuracy, fresh sod was fed into the system simulating normal cutting conditions. Along with the extensive velocity analysis, strain and static pressure were also examined at various surface locations along the blade using linear strain gages and a piezoresistive pressure transducer. It has been observed that the deck and blade configurations share equal significance in the resultant flow profiles.
Three-Dimensional Flow Analysis for Estimation of Measuring Error of Orifice Flowmeter Due to Upstream Flow Distortion
Authors: Kim Hong-Min , Kim Kwang-Yong , Her Jae-Young , Ha Young-Chul
Published: March 2009

Three-dimensional pipe flows with elbows and tees are calculated to estimate the effect of upstream flow distortion on measuring accuracy of orifice flow meter. Axisymmetric flows through orifice are calculated first to evaluate the performances of various numerical schemes and turbulence models. In three-dimensional calculations of the flow in pipe system, it is evaluated how the pressure difference across the orifice is dependent on the length of upstream straight pipe in a branch. From the results, it is found that, regardless of flow rate, the effect of the length can be neglected for the lengths larger than thirty diameters although there still remain significant swirl at the orifice.
Error Free Liquid Flow Diverters for Calibration Facilities
Authors: Yeh T. T. , Yende N. P. , Johnson A. , Espina P. I.
Published: March 2009

A design for diverter valves in gravimetric liquid flow calibration facilities is proposed. The concept makes use of repeated unidirectional motions of the diverter valve to reduce errors associated with asymmetry in the diverter valve motion and in the liquid jet velocity profile. Various implementation examples are provided and their benefits are discussed.
Two-Phase Flow Pressure Drop of High Quality Steam
Authors: Curtis J. M. , Coffield R. D.
Published: March 2009

Two-phase pressure drop across a straight test pipe was experimentally determined for high Reynolds (Re) number steam having an average flow quality range of 0.995 to 1.0, where flow quality is defined as the weight fraction of the vapor in a two-phase mixture. This flow regime is representative of most steam plant piping hydraulic conditions during full power operation. The testing described has been performed in order to reduce uncertainties associated with the effects of two-phase flow on pressure drop. In addition to moisture carryover from the steam generator, two-phase flow develops in steam piping because a small fraction of the steam flow condenses due to heat loss to the surroundings. A recent comprehensive survey of the literature published by Tong and Tang (1997) identified no applicable sources of information of two-phase flow pressure drop data near the design range of interest. The two-phase flow pressure drop data obtained in this test has enabled the development of a design correlation between friction factor, Reynolds number, and flow quality.
The Effect of the Local Inertial Term on the Free Convection Fluid Flow in Vertical Channels Partially Filled With Porous Media
Authors: Khadrawi A. F. , Al-Nimr M. A.
Published: March 2009

The transient hydrodynamics and thermal behaviors of the free convection fluid flow in open-ended vertical parallel-plate channels partially filled with porous material are investigated. The role of the local macroscopic inertial term in the porous domain momentum equation is studied. It is found that the effect of the local inertial term on the channel behavior is insignificant when the Darcy number is less than 1E−4 for all operating conditions. Also, the effect of the macroscopic inertial term is insignificant at large values of the viscosity ratio >1.0, and over the entire ranges of diffusivity ratio, conductivity ratio, and Prandtl number.
Wavelet-Preconditioned Conjugate Gradient Poisson Solver and Its Use in Parallel Processing: Application of Haar Wavelet
Authors: Tanaka Nobuatsu
Published: March 2009

Haar-wavelet-based preconditioning technique for conjugate gradient Poisson solvers is described. The proposed method is suitable for parallel processing because of data locality. The method also has a superior property of preventing the computing time from increasing markedly with the increase in the number of grid points. These kinds of combined approaches of software and hardware are superior in large scale problems and will play more important roles in future computational science.
Micro-Scale Velocity Measurements Using Molecular Tagging Velocimetry: Methodology and Uncertainty
Authors: Thompson B. R. , Maynes D. , Webb B. W.
Published: March 2009

Micro-scale fluidic devices are now being designed and manufactured for a host of new applications, and it is certain that new applications will emerge. There is, therefore, a need for increased understanding of the momentum transport phenomena at this scale to aid in the understanding, and design and optimization of such devices. This need is behind the development of new techniques for making flow measurements at the micro-scale. Molecular Tagging Velocimetry (MTV) is a laser-based non-intrusive technique for obtaining detailed measurements of velocity profiles. This paper reports on the extension of the method to microtubes of inside diameter of order 100 µm. Fully developed velocity profile measurements are reported here for a Reynolds number of about 140 in a capillary of inside diameter 148 µm. Two image analysis techniques were compared—the line center method, and the correlation method. It was found that the correlation method produced better results and smaller overall uncertainty. Volumetric flow rate determined from integration of the measured velocity profiles agree with accumulation measurements made over a specified time interval to within 3%; the agreement was usually 1–2%. This work reports on the difficulties encountered in applying MTV at these physical scales, the influence of measurement and analysis parameters on results, and the uncertainty associated with measurements.
Early-Injection and Time-Resolved Evolution of a Spray for GDI Engines
Authors: De Vita A. , Di Angelo L. , Allocca L.
Published: March 2009

An extensive experimental study on sprays from an injector for gasoline direct injection (GDI) engines has been performed. Spatial and temporal evolution measurements of a large cone-angle jet, emerging from a high pressure swirled injector, have been carried out in an optically accessible vessel. The spray has been lightened, both along the spray axis and in cross sections perpendicular to it, by a 532 nm Nd-YAG pulsed laser sheet, 80 mm thickness and 12 ns duration. The scattered light has been collected at 90° with respect to the sheet direction by a digital CCD camera with a frame grabber synchronized with the injection command and the laser pulse. A digital delay system has provided a fine temporal shift (up to microseconds range) of the images acquisition with respect to the start of the injection (SOI). Finally, a digital image processing system has provided analysing the images collected by the CCD camera. The emerging spray has been acquired with three spatial scales, providing both the global and local spray behaviour, and with a detailed temporal resolution to characterize the early stage of the jet formation. The initial phase of the spray is characterized by a strong axial component of the velocity with respect to the radial one, resulting in a pre-spray or slug phase. It produces a cylindrical shape of the jet with the characteristic mushroom shape. Large droplets with high momentum are produced, travelling downstream in advance to the main spray. At later time the radial velocity component controls the process and it gives up to the classical hollow-cone shape with a strong interaction with the gas in the vessel. The images give evidence in time of the collapse of the hollow-cone structure hence resulting in a full cone spray. This behaviour is confirmed by the cross section measurements through the spray, carried out in the range 10–40 mm from the nozzle tip. These measurements make evidence of the refilling of the cone with the presence of strong vortexes on the boundary of the jet. The effects of the fuel injection pressure, injection duration and air-flow field interaction on the structure and evolution of the spray have been studied in details. The digital image processing system also has allowed to reconstruct the spray profile and to determine a refilling index.
Numerical Flow Visualization and Thermal Transport Phenomena Over a Slot-Perforated Flat Surface in Pulsating Channel Flow
Authors: Torii Shuichi , Yang Wen-Jei
Published: March 2009

A theoretical study is performed to investigate unsteady, two-dimensional, incompressible thermal-fluid flow over both sides of a slot-perforated flat surface, which is placed in a pulsating channel flow. The roles of both the pulsating Strouhal number and the ratio of the channel width to the plate thickness, W/δ, on the velocity and thermal fields are disclosed. It is found from the study that: (i) when the channel stream is pulsated, the alternating change in the fluid flow disturbs the thermal boundary layer formed along the plate and induces mixing of the upper and lower streams of the plate downstream from the slot, resulting in an amplification of heat transfer performance, and (ii) heat transfer performance at the plate is attenuated with a decrease in W/δ.
Visualisation of Turbulent Wedges Under Favourable Pressure Gradients Using Both Shear-Sensitive and Temperature-Sensitive Liquid Crystals
Authors: Zhong S. , Chong T. P. , Hodson H. P.
Published: March 2009

Turbulent wedges induced by a 3D surface roughness placed in a laminar boundary layer over a flat plate were visualised for the first time using both shear-sensitive and temperature-sensitive liquid crystals. The experiments were carried out at three different levels of favourable pressure gradients. The purpose of this investigation was to examine the spreading angles of the turbulent wedges indicated by their associated surface shear stresses and heat transfer characteristics and hence obtain further insight about the difference in the behaviour of transitional momentum and thermal boundary layers when a streamwise pressure gradient exists. It was shown that under a zero pressure gradient the spreading angles indicated by the two types of liquid crystals are the same, but the difference increases as the level of favourable pressure gradient increases. The result from the present study could have an important implication to the transition modelling of thermal boundary layers over gas turbine blades.