bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential Predictors of African American and Hispanic Parent Retention in a Family‐Focused Preventive Intervention*
Authors: Coatsworth J. Douglas , Duncan Larissa G. , Pantin Hilda , Szapocznik José
Published: March 2006

Abstract:Similarities and differences in predictors of retention/attendance patterns between African American and Hispanic parent participants (N= 143) from a family‐focused preventive intervention were examined. Three broad retention pattern groups, nonattenders, variable attenders, and consistent high attenders, and 2 subgroups of the variable attendance group, decreasing low attenders and decreasing high attenders, were identified. In subgroup analyses, 3 significant discriminant functions were evident: 1 function classified Hispanic parents’ retention patterns using sociodemographic indicators (e.g., educational attainment, household income) and 2 functions discriminated Hispanic and African American parents’ patterns using family‐level predictors (e.g., multiple caregivers attending the intervention, perceived barriers to participation). Implications are discussed in terms of strategies for improving methods of retaining participants in family‐centered interventions conducted with ethnic minority families.
Cooperative Learning Through Collaborative Faculty‐Student Research Teams*
Authors: McWey Lenore M. , Henderson Tammy L. , Piercy Fred P.
Published: March 2006

Abstract: A structured research team experience can add a great deal to a graduate student's academic and professional training, and it also can support a positive research culture within a department. In this study, we discuss how one department developed and implemented collaborative learning research teams to enhance students’ research experiences. We discuss the advantages of cooperative learning and share student and faculty reflections that further support the use of collaborative learning research teams.
Review of animal models for autism: implication of thyroid hormone
Authors: Sadamatsu Miyuki , Kanai Hirohiko , Xu Xiaobin , Liu Ying , Kato Nobumasa
Published: March 2006

ABSTRACT    Autism is a behaviorally defined disorder associated with characteristic impairments in social interactions and communication, as well as restricted and repetitive behaviors and interest. Its prevalence was once thought to be 2/10 000, but recently several large autism prevalence reviews revealed that the rate of occurrence was roughly 30/10 000. While it has been considered a developmental disorder, little is certain about its etiology. Neuroanatomical studies at the histological level in the brains of autistic patients provide many arguments in the etiology of autism. Results from postmortem and imaging studies have implicated many major structures of the brain including the limbic system, cerebellum, corpus callosum, basal ganglia and brainstem. There is no single biological or clinical marker for autism. While several promising candidate genes have been presented, the critical loci are yet unknown. Environmental influences such as rubella virus, valproic acid, and thalidomide exposure during pregnancy are also considered important, as concordance in monozygotic twins is less than 100% and the phenotypic expression of the disorder varies widely. It is thus hypothesized that non‐genetic mechanisms contribute to the onset of autistic syndrome. In light of these ambiguities, hope is held that an animal model of autism may help elucidate matters. In this article, we overview most of the currently available animal models for autism, and propose the rat with mild and transient neonatal hypothyroidism as a novel model for autism.
Effects of maternal uninephrectomy on the development of fetal rat kidney: apoptosis and the expression of oncogenes
Authors: Okada Toshiya , Mitsuoka Koji , Mino Masaki , Mukamoto Masafumi , Nakamura Jun , Morioka Hiroshi , Morikawa Yoshio
Published: March 2006

ABSTRACT    The present study was designed to explore whether maternal uninephrectomy affects development of the collecting ducts in fetal kidney. Localization of DNA fragmented cells in the kidney of fetal rats from uninephrectomized mothers were examined by the terminal deoxynucleotidyl transferase (TdT)‐mediated d‐UTP‐biotin nick end labeling (TUNEL) method. Immunohistochemistry was used to examine the localizations of bcl‐2 gene products. The gene expressions for bcl‐2, p53, and WT1 mRNAs were examined by using the semi‐quantitative reverse transcript‐polymerase chain reaction. TUNEL positive cells were more numerous in the medullary collecting ducts of the fetuses from uninephrectomized mothers than in those of the fetuses from sham‐operated ones. The expressions of bcl‐2, p53, and WT1 mRNAs were lower in the fetuses from uninephrectomized mothers than in the fetuses from sham‐operated ones. Cells in the medullary collecting ducts showed positive reactions to anti‐bcl‐2 gene products antibody with the reactions being weaker in the fetuses from uninephrectomized mothers. These results showed that maternal uninephrectomy accelerated the development of fetal rat kidney and it was associated with the lowered the expression of bcl‐2 in fetal rat kidney.
CEO Tenure in Taiwanese Family and Nonfamily Firms: An Agency Theory Perspective
Authors: Tsai Wen-Hsien , Hung Jung-Hua , Kuo Yi-Chen , Kuo Lopin
Published: March 2006

This study investigated the tenure of CEOs in a sample of 304 listed companies in Taiwan; 63 firms were family controlled, 241 were not. The results show that CEO turnover is significantly lower in family firms and its relationship to corporate performance is negative. CEO ownership and board ownership are not significant in explaining the length of family CEO tenure. These findings imply that family boards can still effectively replace the CEO despite relatively low ownership. From the ownership structure perspective, this study suggested that the agency theory is applicable for nonfamily firms in Taiwan, but unsuitable for family firms.
Family Business in the Middle East: An Eexploratory Study of Retail Management in Kuwait and Lebanon
Authors: Welsh Dianne H. B. , Raven Peter
Published: March 2006

The Middle East is a growing, lucrative marketplace that has recently captured the interest of the world for political as well as economic reasons due to the War in Iraq, which began in 2003. This exploratory study examines the relationship between retail small/medium enterprises (SMEs) that are family business owned, organizational commitment, and management and employee perceptions of customer service on a number of dimensions. The results suggest that managers and employees of family-owned businesses in the Middle East behave in ways similar to those in Western countries; however, there are differences, probably related to cultural characteristics. The Middle East is a richly diverse region, a myriad of unique cultures. As the market becomes more sophisticated, the importance of service quality increases. Global retailers can benefit from this study by better understanding the managers and employees in the region and the pivotal role of the family on business. Implications for practice are discussed.
Family Dynamic and Family Business Financial Performance: Spousal Commitment
Authors: Van Auken Howard , Werbel James
Published: March 2006

This article views the survival of a family business as partially dependent on spousal commitment. The decision to launch a business should depend not only on analysis of the opportunity, but also on the degree to which one's spouse shares a common vision about the goals, risks, and rewards of the business. Models and testable hypotheses are developed to guide empirical research on the antecedents and consequences of spousal commitment to a family business. The models can benefit individuals considering the launch of a business, couples that currently own a business, business consultants, and university instructors teaching entrepreneurship courses.
The Relationship Between Boards and Planning in Family Businesses
Authors: Blumentritt Timothy
Published: March 2006

This study examines relationships between the existence of boards of directors and advisory boards and the use of planning in family businesses. It is argued that both of the primary roles of boards, the governance of a firm's management team for the firm's stake-holders and the provision of valuable business resources to the firm's management team, are significantly related to the use of planning activities in family businesses. The empirical evidence, drawn from a survey of more than 130 family businesses, largely supports the hypotheses. Conclusions and suggestions for future research close the article.
Family Governance and Firm Performance: Agency, Stewardship, and Capabilities
Authors: Miller Danny , Le Breton-Miller Isabelle
Published: March 2006

After decades of being viewed as obsolete and problem ridden, recent research has begun to show that major, publicly traded family-controlled businesses (FCBs) actually out-perform other types of businesses. This article examines the nature of such family businesses in an attempt to explain why some seem to do so well and others so poorly. It begins with four fundamental governance choices that distinguish among different kinds of family businesses: level and mode of family ownership, family leadership, the broader involvement of multiple family members, and the planned or actual participation of later generations. Using precepts from agency and stewardship theory, it relates these dimensions to the nature of the resource-allocation decisions made by the business and capability development, which in turn have implications for financial performance. Propositions are drawn about the drivers that make some family businesses great competitors—while leaving others at a disadvantage.
Comparison of the abilities of redtop (Agrostis alba L.) and zoysiagrass (Zoysia japonica Steud.) to purify liquid animal waste
Authors: Takada‐Oikawa Naoko , Kawanabe Sukeo , Oshida Toshio , Itagaki Shin‐ichi , Onozawa Minori , Sakurai Masumi
Published: March 2006

The animal waste treatment facility of Azabu University utilizes cultivation beds where liquid animal waste is purified by filtration through soil and vegetation. The beds are presently covered with zoysiagrass (Zoysia japonica Steud.), which thrives in warm weather. However, the purification activities of this grass decrease during winter dormancy. To improve purification activity between autumn and early spring, we introduced redtop (Agrostis alba L.), which thrives in cool conditions, into an experimental bed and compared the purification efficiency with that of zoysiagrass. Drainage purified through the bed of redtop showed significantly lower values of turbidity, chemical oxygen demand, total phosphorus and ammonium‐nitrogen concentrations, and significantly higher nitrate‐nitrogen concentrations than that through zoysiagrass during the late vegetative stage when redtop had the highest biomass. This suggested vigorous nitrification activity of rhizosphere under aerobic conditions afforded by redtop. The high purification efficiency of redtop appeared to be associated with better essential salts absorption and improved physicochemical properties of soil supporting its growth. The results showed that the purification efficiency of redtop is higher than that of zoysiagrass under seasonal low temperatures.
Neotyphodium endophyte infection affects the performance of tall fescue in temperate region Andisols
Authors: Rahman M. Hasinur , Saiga Suguru , Sabreen Shamima , Kodama Yukinobu , Tsuiki Mikinori
Published: March 2006

A pot experiment was conducted for 75 days to observe the effect of Neotyphodium coenophialum endophyte on three tall fescue (Festuca arundinacea Schreb.) ecotypes grown in two Andisols viz. Black Andisol and Red Andisol. Black Andisol with a naturally low content of P was high in other nutrients such as N, K, while Red Andisol, with a naturally high content of P, was low in other nutrients. Tiller number, plant height, chlorophyll content, shoot dry weight and agronomic efficiency of water use (WUEag) showed higher values in endophyte‐infected (E+) plants than noninfected (E–) plants. Plants growing in Black Andisol performed better than those in Red Andisol. Among the three tall fescue ecotypes, one of them (ecotype Showa) had the best performance regardless of soils and endophyte infection. When considering the effect of endophyte infection in different soil conditions, higher WUEag was observed in endophyte‐infected plants grown in Black Andisol. Endophyte infection significantly enhanced all plant parameters in Black Andisol but they were reduced in Red Andisol. Our results indicate that infected plants grew better in soil that was naturally low in P whereas uninfected plants had increased vegetative growth in soil that was naturally high in P. In nutrient poor soil with comparatively high P content (Red Andisol) the cost of endophyte infection may override its benefit. The presence of endophyte had a variable impact on plant performance and the effect of endophyte varied with ecotype of grass it infected into.
Nitrate concentration of groundwater and its association with livestock farming in Miyakonojo Basin, southern Kyushu, Japan
Authors: Sugimoto Yasuhiro , Hirata Masahiko
Published: March 2006

Nitrate concentration of groundwater was surveyed in 741 wells in 10 districts in central Miyakonojo Basin, southern Kyushu, Japan, to determine the nitrate status in the region and to examine its association with livestock farming. Nitrate‐N concentration averaged 5.4 mg L−1, with 13% of the wells exceeding the maximum contaminant level (MCL) for drinking water (10 mg L−1). Wells possessed by farmers had a higher maximum (48.6 versus 27.6 mg L−1), mean (7.4 vs 3.6 mg L−1) and percentage above the MCL (23 versus 5%) than those possessed by nonfarmers. Occurrence of nitrate in groundwater varied not only with the ownership of wells but also among the districts (mean nitrate‐N concentration = 3.0–8.6 mg L−1, percentage above the MCL = 0–32%). The mean nitrate‐N concentration of individual districts was positively correlated with both excretal nitrogen output from livestock (r = 0.725, P = 0.018) and excretal nitrogen load to farmland (r = 0.864, P = 0.001). The results show that groundwater quality in central Miyakonojo Basin was considerably deteriorated mainly in farmers’ wells, with livestock farming as a responsible source of nitrate contamination.
Ant Diversity and Abundance along an Elevational Gradient in the Philippines1
Authors: Samson Douglas A. , Rickart Eric A. , Gonzales Pedro C.
Published: March 2006

Ant communities were surveyed along an elevational gradient in the Philippines extending from lowland dipterocarp forest (250 m elevation) to mossy forest (1750 m). Standardized pitfall trapping in arboreal and terrestrial microhabitats at seven sites yielded 51 species. Collecting by hand at five of the sites yielded 48 species. The two methods produced substantially different assemblages, with only 22 species (29%) taken in common. Only a fraction of the total ant community appeared to be sampled at most of the sites. Measures of species richness and relative abundance peaked at mid‐elevations and declined sharply with increasing elevation. Ants were extremely rare above 1500 m elevation. Arboreal ants were trapped much less frequently than terrestrial ants at all sites. Ant species that were abundant had broader elevational distributions than those that were less common, but most species were rare and occurred at only one or two sites. The elevational patterns for ants are largely the inverse of those documented for Philippine small mammals which reach their greatest diversity and abundance at high elevations where ants are rare. This suggests that the two groups may interact competitively. Some of the patterns observed or inferred from this study may apply to tropical ant communities in general, and are presented as series of testable hypotheses as a guide and stimulus for future research.
Heterogeneity of Light Availability and its Effects on Simulated Carbon Gain of Tree Leaves in a Small Gap and the Understory in a Tropical Rain Forest1
Authors: Tang Yanhong , Kachi Naoki , Furukawa Akio , Awang Muhamad B.
Published: March 2006

To clarify the small‐scale heterogeneity of light regimes in a rain forest, photosynthetic photon flux density (PFD) was measured at 1‐min intervals during six days at 12 microsites in each of two plots, a small gap and an understory in Pasoh Forest Reserve, Peninsular Malaysia. Frequency distribution of microsite PFD was unimodal with the peak value between 16 and 32 μmol/m2/sec in the small gap, but between 8 and 16 μmol/m2/sec in the understory. In the small gap, PFD was more variable among microsites; total daily PFD and daily sunfleck PFD exceeding 10 μmol/ m2/sec tended to be higher (P <0.05; t‐test) compared to those in the understory. Sunfleck PFD exceeding 50 μmol/ m2/sec, however, showed no difference between the two plots. Diffuse PFD transmittance, defined as the ratio of PFD in the forest to that measured at 43 m above ground during the periods 0800‐0810 and 1750‐1800 h, was significantly higher in the small gap than in the understory plot. Diffuse PFD transmittance was also positively correlated with microsite total daily PFD. To examine the effects of the subtle heterogeneity of light regimes on leaf carbon gain, we simulated carbon gain by sun and shade leaves in a typical shade‐tolerant species, Brosimum aticastrum Sw. (Moraceae). Despite the similarity in total daily PFD, total daily carbon gain was considerably higher in the gap than in the understory for both sun and shade leaves. This study suggests that frequency distribution of PFD is critical in describing microsite PFD regimes and determining leaf carbon gain in the tropical forest floor.
Grazing Lawns in Terai Grasslands, Royal Bardia National Park, Nepal1
Authors: Karki Jhamak Bahadur , Jhala Yadavendardev V. , Khanna Param Pal
Published: March 2006

We compared the community structure, nutritive quality, and aboveground biomass of grazing lawns (patches of shortgrass communities) to neighboring grasslands in the Terai of western Nepal. Grazing lawns differed from the adjacent grasslands in species composition and community structure. Species diversity and species richness were higher on grazing lawns (H = 1.60, S = 20.93) than the grasslands (H = 0.97, S = 8.97). Fencing that excluded grazers for 150 days made areas of grazing lawns indistinguishable from neighboring grasslands in terms of plant height and biomass. Growing shoots of forage from grazing lawns had higher digestibility, crude protein, and sodium than forage from the grasslands. Grazing lawns appear to be maintained by continuous grazing and are enriched by deposition of urine, dung, and by certain plant species not found in the the adjacent grasslands.
Influence of Forest Type and Tree Species on Canopy‐Dwelling Beetles in Budongo Forest, Uganda1
Authors: Wagner Thomas
Published: March 2006

Beetles were collected on 64 trees of four species (Cynometra alexandri C. H. Wright, Rinorea beniemis (Welwitsch ex Olivier) Kuntze, Teclea nobilis Delile, and Trichilia rubescens Olivier) in Budongo Forest, Uganda, using an insecticidal fogging technique. Selected tree species were abundant, taxonomically not closely related, and different in the shape of leaves, growth form, and size, with heights between 7 and 35 m. Trees were fogged in an old primary forest stand, in an area of secondary forest where selective logging was performed, and in a swamp forest. Eight conspecific trees per forest type were fogged. A total of 29,736 beetles were collected from all trees that could be assigned to 1433 (morpho)‐species; 41.6 percent were singletons and 89.6 percent of species were found with less than ten individuals. Abundant beetle taxa included Latridiidae (N= 4093), Chrysomelidae (3952), Staphylinidae (2931), Apioninae (2621), and Curculionidae (2457). Most species‐rich groups were Staphylinidae (N= 196 spp.), Curculionidae (189), and Chrysomelidae (148). Abundance increased in the order: primary < secondary < swamp forest. Due to the relatively high dominance of some species in the secondary forest, species richness increased in the order: secondary < primary < swamp forest. Beta diversity measures and factor analysis showed distinct differences among forest types but higher similarity of beetle communities on different tree species within one forest type. The taxonomic distribution of beetles in the secondary forest was more heterogeneous than in the primary forest. Analyses of the data revealed low host specificity even for phytophagous beetles, underlining the importance of habitat structure and chance effects on the spatial distribution of beetles in the canopy of Budongo Forest.
Influence of Fruit Availability on Ecological Overlap among Four Neotropical Primates at Tinigua National Park, Colombia1
Authors: Stevenson Pablo R. , Quiñones Marcela J. , Ahumada Jorge A.
Published: March 2006

Data on fruit abundance and ecological overlap amongAteles belzebuth, Lagothrix lagothricha, Cebus apella, andAlouatta seniculuswere gathered during 13 months at Tinigua National Park (Colombia), in an effort to test the following hypotheses concerning competition for fruits. Coexistence is possible because: (1) during periods when fruit availability is limited, the species utilize different resources; and (2) the species have different fruit preferences independent of fruit production in the forest. Differences were found in resource use (diet and habitat) for all four species. Despite these differences, all four devoted large proportions of time feeding on fruit. Fruit abundance influenced their activity patterns. Ninety percent of all interspecific aggressive interactions (TV = 69) were seen in fruiting trees. The first hypothesis was best supported, given that all species significantly increased their intake of the vegetative parts of plants during periods of fruit scarcity. Fruit partitioning during periods of scarcity was observed clearly only for one pair of species (C. apellaandL. lagothricha).In general, the second hypothesis was not supported as a mechanism for reducing competition because most fruit species were consumed by more than one primate species. Fruit preferences, however, may be particularly important in explaining differences in niche overlap between the most ecologically similar species:A. belzebuthrelied heavily on the fruits of one palm species (Oenocarpus bataud) during periods of fruit scarcity and abundance, whileL. lagothrichacompletely ignored this fruit.
Clidemia hirta Invasion at the Pasoh Forest Reserve: An Unexpected Plant Invasion in an Undisturbed Tropical Forest1
Authors: Peters Halton A.
Published: March 2006

Clidemia hirta is a highly invasive shrub in tropical forests throughout the world, but has had little success invading mainland sites and undisturbed forests. In the early 1990s, this plant was found to have invaded an unexpected site, an undisturbed continental tropical forest at Pasoh, Peninsular Malaysia. In 1997, a study was conducted of the C. hirta population at the Pasoh Forest Reserve. A demographic survey of the 50–ha long–term research plot at Pasoh located 1002 C. hirta individuals, 69 of which were reproductive at the time of the study. All but 8 individuals were located in high light gaps or gap edges. Relative growth rates were significantly higher in gaps and gap edges than in the understory, and no reproductive individuals were found in the understory. Mean plant size and dry biomass density increased steadily over the course of the study, while the observed mortality rate was 0 percent over two months. The biomass density of Clidemia at Pasoh was <500 g/ha at the conclusion of this study, but because the population is confined almost exclusively to high light environments, its density in these sites is much higher. The location of C. hirta plants in gaps was significantly correlated with past disturbance by wild pigs, suggesting that soil disturbance and light availability are essential for their establishment. The implication of this study is that by competing with native species in gaps, C. hirta invasion has the potential to alter forest regeneration at Pasoh. Changing land use practices near the reserve have increased the number of wild pigs, and thus the level of disturbance, which may explain the recent success of C. hirta at Pasoh.
Factors Affecting the Small Mammal Community Inside and Outside Katavi National Park, Tanzania1
Authors: Caro T. M.
Published: March 2006

Small mammal trapping showed that a minimum of 12 species live in and around Katavi National Park in western Tanzania. Species richness and abundance were greater outside the park than inside, extending results of an earlier study. Species richness and abundance were not significantly associated with vegetation cover or plant biomass but were negatively correlated with seed diversity, seed biomass, and possibly small carnivore abundance. Unfortunately, small mammal diets are unknown in this ecosystem and it can be argued that carnivores are unlikely to reduce species diversity, casting doubt on the importance of these variables. While the factors causing small mammals to fare poorly in this protected area are not yet understood, reduced food availability remains the best candidate.
A cosmic relation between extinction and star formation
Authors: Zoran Oren , Barkana Rennan , Thompson Rodger I.
Published: March 2006

We study the relation between the star formation intensity of galaxies and the extinction by dust of their emitted light. We employ a detailed statistical analysis of Hubble Deep Field North data to show a clear positive correlation between the extinction and star formation intensity at all epochs from redshift 0.4 to 6.5. The extinction evidently increases with time for a given star formation intensity, consistent with the expected increase in the metallicity with time. Our observational results are well fitted at all epochs by a double-power-law model with a fixed shape that simply shifts with redshift. The correlation between the extinction and the star formation intensity can be interpreted by combining two other trends: the correlation between the star formation rate and the gas content of galaxies, and the evolution of the dust-to-gas ratio in galaxies. If we assume that Kennicutt's observed relation for the former is valid at each redshift, then our findings imply an interesting variation in the dust-to-gas ratio in galaxies within each epoch and with time, and suggest new ways to investigate the cosmic evolution of this quantity.
A Cell‐permeable NFAT Inhibitor Peptide Prevents Pressure‐Overload Cardiac Hypertrophy
Authors: Kuriyama Mitsuhito , Matsushita Masayuki , Tateishi Atsushi , Moriwaki Akiyoshi , Tomizawa Kazuhito , Ishino Kozo , Sano Shunji , Matsui Hideki
Published: March 2006

The activation of the calcineurin–nuclear factor of activated T cells cascade during the development of pressure‐overload cardiac hypertrophy has been previously reported in a number of studies. In addition, numerous pharmacological studies involving calcineurin inhibitors such as FK506 and cyclosporine A have now demonstrated that these agents can prevent such hypertrophic responses in the heart. However, little is known regarding the roles of the calcineurin downstream effecter – nuclear factor of activated T cells. Our present study has further examined the roles of nuclear factor of activated T cells in pressure‐overload cardiac hypertrophy by employing a recently developed cell‐permeable nuclear factor of activated T cells inhibitor peptide. Rat hearts were subjected to pressure overload attributable by 4 weeks of aortic banding, and then treated with this cell‐permeable nuclear factor of activated T cells inhibitor peptide and a control peptide. Treatment with the inhibitor was found to significantly decrease the heart weight/body weight ratio, the size of cardiac myocytes, and the serum brain natriuretic peptide and atrial natriuretic peptide levels. These results suggest that nuclear factor of activated T cells functions in a key role in the development of cardiac hypertrophy during pressure overload. Inhibition of nuclear factor of activated T cells by a specific inhibitor peptide is a suitable method for characterization of the molecular mechanisms underlying cardiac hypertrophy as well as in the search for new promising therapies for disease.
Substituted 1,4‐Benzodiazepine‐2,5‐diones as α‐Helix Mimetic Antagonists of the HDM2‐p53 Protein–Protein Interaction
Authors: Cummings Maxwell D. , Schubert Carsten , Parks Daniel J. , Calvo Raul R. , LaFrance Louis V. , Lattanze Jennifer , Milkiewicz Karen L. , Lu Tianbao
Published: March 2006

Small molecule antagonists of protein–protein interactions represent a particular challenge for pharmaceutical discovery. One approach to finding molecules that can disrupt these interactions is to seek mimics of common protein structure motifs. We present an analysis of how molecules based on the 1,4‐benzodiazepine‐2,5‐dione scaffold serve to mimic the side‐chains presented by the hydrophobic face of two turns of an α‐helix derived from the tumor suppressor protein p53, and thus antagonize the HDM2‐p53 protein–protein binding interaction.
Wedded to ‘fault’: the legal regulation of divorce and relationship breakdown
Authors: Hasson Ezra
Published: March 2006

In December 2005, the Civil Partnership Act 2004 came into force, thereby enabling same-sex couples to obtain formal legal recognition of their relationships. By modelling the provisions for dissolving such partnerships on divorce law, the government effectively transposed into the new regime both a fault-based ‘system’ and the accompanying sense that the law is vested with a role beyond that of simply ending relationships. In view of the recent, but ultimately failed, attempt to introduce no-fault divorce, this paper explores the role of law in this context. Drawing on a series of interviews with key individuals involved in the reform process, it explores how no-fault divorce was hijacked in a vain effort to provide simultaneous means of saving and ending marriage. In particular, the veto wielded by an influential group of idealistic conservatives during the latter stages of the reform process is identified. Given the inability or unwillingness of reformers to confront such conservatism with either a thoroughgoing defence of diversity, or the reality of the limited capacity of states to legislate for morality, the paper calls for a re-evaluation of the law’s role. It questions whether the Civil Partnership Act 2004 represents a missed opportunity to conduct such a re-evaluation and thus to point the way for future divorce reform.
Thermal Cavitation Experiments on a NACA 0015 Hydrofoil
Authors: Cervone Angelo , Bramanti Cristina , Rapposelli Emilio , d’Agostino Luca
Published: March 2006

The present paper illustrates the main results of an experimental campaign conducted in the Thermal Cavitation Tunnel of the Cavitating Pump Rotordynamic Test Facility (CPRTF) at Centrospazio/Alta S.p.A. Experiments were carried out on a NACA 0015 hydrofoil at various incidence angles, cavitation numbers, and freestream temperatures, in order to investigate the characteristics of cavitation instabilities and the impact of thermal cavitation effects. Measured cavity length, surface pressure coefficients, and unsteady pressure spectra are in good agreement with the data available in the open literature and suggest the existence of a strong correlation between the onset of the various forms of cavitation and instabilities, the thermal cavitation effects, and the effects induced by the presence of the walls of the tunnel. Further analytical investigations are planned in order to provide a better interpretation of the above results.
Exit Flow Field and Performance of Axial Flow Fans
Authors: Yen S. C. , Lin Frank K. T.
Published: March 2006

Flow fields near the exit and the global performance parameters of the various types of axial flow fans are studied with Particle Image Velocimetry and a standard AMCA 210 flow bench. The fans used in this study included the shrouded, shroudless, and winglet-blade types. The velocity vectors, streamlines, vorticity contours, velocity distributions, and performances are presented and discussed. The flow patterns on the radial and axial planes show that a vortex always exists near the exit of the fans at various impeller angles. The experimental results demonstrate that the shrouded fan with winglets has the most stable flow field and the best fan performance.
Propulsion System Requirements for Long Range, Supersonic Aircraft
Authors: Brear Michael J. , Kerrebrock Jack L. , Epstein Alan H.
Published: March 2006

This paper discusses the requirements for the propulsion system of supersonic cruise aircraft that are quiet enough to fly over land and operate from civil airports, have trans-pacific range in the order of 11,112km(6000nmi), and payload in the order of 4545kg(10,000lb.). It is concluded that the resulting requirements for both the fuel consumption and engine thrust/weight ratio for such aircraft will require high compressor exit and turbine inlet temperatures, together with bypass ratios that are significantly higher than typical supersonic-capable engines. Several technologies for improving both the fuel consumption and weight of the propulsion system are suggested. Some of these directly reduce engine weight while others, by improving individual component performance, will enable higher bypass ratios. The latter should therefore also indirectly reduce the bare engine weight. It is emphasized, however, that these specific technologies require considerable further development. While the use of higher bypass ratio is a significant departure from more usual engines designed for supersonic cruise, it is nonetheless considered to be a practical option for an aircraft of this kind.
Effects of Weak Free Stream Nonuniformity on Boundary Layer Transition
Authors: Watmuff Jonathan H.
Published: March 2006

Experiments are described in which well-defined weak Free Stream Nonuniformity (FSN) is introduced by placing fine wires upstream of the leading edge of a flat plate. Large amplitude spanwise thickness variations form in the boundary layer as a result of the interaction between the steady laminar wakes from the wires and the leading edge. The centerline of a region of elevated layer thickness is aligned with the centerline of the wake in the freestream and the response is shown to be remarkably sensitive to the spanwise length-scale of the wakes. The region of elevated thickness is equivalent to a long narrow low speed streak in the layer. Elevated Free Stream Turbulence (FST) levels are known to produce randomly forming arrays of long narrow low speed streaks in laminar boundary layers. Therefore the characteristics of the streaks resulting from the FSN are studied in detail in an effort to gain some insight into bypass transition that occurs at elevated FST levels. The shape factors of the profiles in the vicinity of the streak appear to be unaltered from the Blasius value, even though the magnitude of the local thickness variations are as large as 60% of that of the undisturbed layer. Regions of elevated background unsteadiness appear on either side of the streak and it is shown that they are most likely the result of small amplitude spanwise modulation of the layer thickness. The background unsteadiness shares many of the characteristics of Klebanoff modes observed at elevated FST levels. However, the layer remains laminar to the end of the test section (Rx≈1.4×106) and there is no evidence of bursting or other phenomena associated with breakdown to turbulence. A vibrating ribbon apparatus is used to examine interactions between the streak and Tollmien-Schlichting (TS) waves. The deformation of the mean flow introduced by the streak is responsible for substantial phase and amplitude distortion of the waves and the breakdown of the distorted waves is more complex and it occurs at a lower Reynolds number than the breakdown of the K-type secondary instability that is observed when the FSN is not present.
Review of Large-Eddy Simulation of Non-Premixed Turbulent Combustion
Authors: Riley James J.
Published: March 2006

Recent developments in the methodology of large-eddy simulation applied to turbulent, reacting flows are reviewed, with specific emphasis on mixture-fraction-based approaches to nonpremixed reactions. Some typical results are presented, and the potential use of the methodology in applications and the future outlook are discussed.
Performance and Internal Flow Characteristics of a Very Low Specific Speed Centrifugal Pump
Authors: Choi Young-Do , Kurokawa Junichi , Matsui Jun
Published: March 2006

In very low specific speed range (ns<0.25), the efficiency of the centrifugal pump designed by the conventional method becomes remarkably low. Therefore, positive-displacement pumps have been widely used for long. However, the positive-displacement pumps remain associated with problems such as noise and vibration and they require high manufacturing precision. Since the recently used centrifugal pumps are becoming higher in rotational speed and smaller in size, there appear to be many expectations to develop a new centrifugal pump with high performance in the very low specific speed range. The purpose of this study is to investigate the internal flow characteristics and its influence on the performance of a very low specific speed centrifugal pump. The results show that large reverse flow at the semi-open impeller outlet decreases absolute tangential velocity considerably which in turn decreases the pumping head.
All-Speed Time-Accurate Underwater Projectile Calculations Using a Preconditioning Algorithm
Authors: Neaves Michael Dean , Edwards Jack R.
Published: March 2006

An algorithm based on the combination of time-derivative preconditioning strategies with low-diffusion upwinding methods is developed and applied to multiphase, compressible flows characteristic of underwater projectile motion. Multiphase compressible flows are assumed to be in kinematic and thermodynamic equilibrium and are modeled using a homogeneous mixture formulation. Compressibility effects in liquid-phase water are modeled using a temperature-adjusted Tait equation, and gaseous phases (water vapor and air) are treated as an ideal gas. The algorithm is applied to subsonic and supersonic projectiles in water, general multiphase shock tubes, and a high-speed water entry problem. Low-speed solutions are presented and compared to experimental results for validation. Solutions for high-subsonic and transonic projectile flows are compared to experimental imaging results and theoretical results. Results are also presented for several multiphase shock tube calculations. Finally, calculations are presented for a high-speed axisymmetric supercavitating projectile during the important water entry phase of flight.
Theoretical Analysis on the Secondary Flow in a Rotating Helical Pipe With an Elliptical Cross Section
Authors: Chen Yitung , Chen Huajun , Zhang Jinsuo , Hsieh Hsuan-Tsung
Published: March 2006

In the present study, the flow in a rotating helical pipe with an elliptical cross section is considered. The axes of the elliptical cross section are in arbitrary directions. Using the perturbation method, the Navier-Stokes equations in a rotating helical coordinate system are solved. The combined effects of rotation, torsion, and geometry on the characteristics of secondary flow and fluid particle trajectory are discussed. Some new and interesting conclusions are obtained, such as how the number of secondary flow cells and the secondary flow intensity depends on the ratio of the Coroilis force to the centrifugal force. The results show that the increase of torsion has the tendency to transfer the structure of secondary flow into a saddle flow, and that the incline angle α increases or decreases the secondary flow intensity depending on the resultant force between the Corilois force and centrifugal force.
Flow in a Pelton Turbine Bucket: Numerical and Experimental Investigations
Authors: Perrig Alexandre , Avellan François , Kueny Jean-Louis , Farhat Mohamed , Parkinson Etienne
Published: March 2006

The aim of the paper is to present the results of investigations conducted on the free surface flow in a Pelton turbine model bucket. Unsteady numerical simulations, based on the two-phase homogeneous model, are performed together with wall pressure measurements and flow visualizations. The results obtained allow defining five distinct zones in the bucket from the flow patterns and the pressure signal shapes. The results provided by the numerical simulation are compared for each zone. The flow patterns in the buckets are analyzed from the results. An investigation of the momentum transfer between the water particles and the bucket is performed, showing the regions of the bucket surface that contribute the most to the torque. The study is also conducted for the backside of the bucket, evidencing a probable Coanda interaction between the bucket cutout area and the water jet.
Aspect Ratio Effects on Turbulent and Transitional Flow in
Rectangular Microchannels as Measured With MicroPIV
Authors: Li Hao , Olsen Michael G.
Published: March 2006

Microscopic particle image velocimetry (microPIV) was used to measure velocities in rectangular microchannels with aspect ratios ranging from 0.97 to 5.69 for 200<Re<3267. Mean velocity profiles, velocity fluctuations, and Reynolds stresses were determined from the microPIV data. Transition to turbulence was observed at Re=1765-2315 for the five aspect ratios studied, agreeing very well with both recent microscale experiments and macroscale duct flow and indicating no evidence of early transition for any of the aspect ratios studied. The onset of fully turbulent flow was observed at Re=2600-3200. For the fully turbulent flow, the ⟨u′⟩∕umax and ⟨v′⟩∕umax fluctuations at the channel centerline were 6% and 3%–3.5% and generally agreed well with macroscale results. As aspect ratio increased, the ⟨u⟩∕umax and ⟨u′⟩∕umax profiles became flatter, with nearly uniform values extending for some distance from the centerline of the channel. This region of uniform ⟨u⟩∕umax and ⟨u′⟩∕umax became larger with increasing aspect ratio. The Reynolds shear stress for fully turbulent flow also displayed a strong dependence on aspect ratio. For the W∕H=0.97 microchannel, ⟨u′v′⟩∕umax2 steadily increased in value moving from the centerline to the wall, but for the higher aspect ratio microchannels, ⟨u′v′⟩∕umax2 remained close to zero in the center region of the microchannel before increasing in value at locations close to the wall, and this region of near zero ⟨u′v′⟩∕umax2 became larger with increasing aspect ratio. This behavior in the Reynolds shear stress is due to the region of uniform velocity and, hence, small mean shear, near the channel centerline of the high aspect ratio microchannels.
Large-Eddy Simulation of Transition in a Separation Bubble
Authors: Roberts Stephen K. , Yaras Metin I.
Published: March 2006

In this paper, large-eddy simulation of the transition process in a separation bubble is compared to experimental results. The measurements and simulations are conducted under low freestream turbulence conditions over a flat plate with a streamwise pressure distribution typical of those encountered on the suction side of turbine airfoils. The computational grid is refined to the extent that the simulation qualifies as a “coarse” direct numerical simulation. The simulations are shown to accurately capture the transition process in the separated shear layer. The results of these simulations are used to gain further insight into the breakdown mechanisms in transitioning separation bubbles.
A Multizone Moving Mesh Algorithm for Simulation of Flow Around a Rigid Body With Arbitrary Motion
Authors: Mirsajedi S. M. , Karimian S. M. H. , Mani M.
Published: March 2006

In this paper, general motion of a two-dimensional body is modeled using a new moving mesh concept. Solution domain is divided into the three zones. The first zone, with a circular boundary, includes the moving body and facilitates the rotational motion of it. The second zone, with a square boundary, includes the first zone and facilitates the translational motion of the body. The third zone is a background grid in which the second zone moves. With this configuration of grids any two-dimensional motion of a body can be modeled with almost no grid insertion or deletion. However, in some stages of motion we merge or split a few number of elements. The discretization method is control-volume based finite-element, and the unsteady form of the Euler equations are solved using AUSM algorithm. To demonstrate the excellent performance of the present method two moving cases including rotational and translational motions are solved. The results show excellent agreement with experimental data or other numerical results.
Modeling the Wall Pressure Spectrum in Turbulent Pipe Flows
Authors: Lysak Peter D.
Published: March 2006

An important source of vibration and noise in piping systems is the fluctuating wall pressure produced by the turbulent boundary layer. One approach to calculating the wall pressure fluctuations is to use a stochastic model based on the Poisson pressure equation. If the model is developed in the wave-number domain, the solution to the wave-number-frequency spectrum can be expressed as an integral of the turbulent sources over the boundary layer thickness. Models based on this formulation have been reported in the literature which show good agreement with measured pressure spectra, but they have relied on adjustable “tuning” constants to account for the unknown properties of the turbulent velocity fluctuations. A variation on this approach is presented in this paper, in which only well-known “universal” constants are used to model the turbulent velocity spectrum. The resulting pressure spectrum predictions are shown to be in good agreement with canonical data sets over a wide range of Reynolds numbers.
Three-Dimensional Flow of a Newtonian Liquid Through an Annular Space with Axially Varying Eccentricity
Authors: de Pina Eduarda P. F. , Carvalho M. S.
Published: March 2006

Flow in annular space occurs in drilling operation of oil and gas wells. The correct prediction of the flow of the drilling mud in the annular space between the well wall and the drill pipe is essential to determine the variation in the mud pressure within the wellbore, the frictional pressure drop, and the efficiency of the transport of the rock drill cuttings. A complete analysis of this situation is extremely complex: the inner cylinder is usually rotating, the wellbore wall will depart significantly from cylindrical, the drill pipe is eccentric, and the eccentricity varies along the well. A complete analysis of this situation would require the solution of the three-dimensional momentum equation and would be computationally expensive and complex. Models available in the literature to study this situation do consider the rotation of the inner cylinder and the non-Newtonian behavior of the drilling fluids, but assume the relative position of the inner with respect to the outer cylinders fixed, i.e., they neglect the variation of the eccentricity along the length of the well, and the flow is considered to be fully developed. This approximation leads to a two-dimensional model to determine the three components of the velocity field in a cross-section of the annulus. The model presented in this work takes into account the variation of the eccentricity along the well; a more appropriate description of the geometric configuration of directional wells. As a consequence, the velocity field varies along the well length and the resulting flow model is three-dimensional. Lubrication theory is used to simplify the governing equations into a two-dimensional differential equation that describes the pressure field. The results show the effect of the variation of the eccentricity on the friction factor, maximum and minimum axial velocity in each cross section, and the presence of azimuthal flow even when the inner cylinder is not rotating.