bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Psychiatric Diagnosis and Family System Relationship on Problems Identified by Families Coping with a Mentally Ill Member*
Authors: Pollio David E. , North Carol S. , Osborne Victoria , Kap Natasha , Foster Douglas A.
Published: May 2004

The purpose of this study was to explore how psychiatric diagnosis and family relationships relate to problems identified by participants in three one‐day public family psychoeducation workshops for families with a member with a serious mental illness. Workshop participants generated lists of problems they had faced, which were coded into eleven categories. Logistic regression models predicting listing of categories were developed based on ill member (diagnosis, sex, treatment compliance) and family member (sex, age, relationship to the ill member) characteristics. For models predicting content category from ill member characteristics, only denial/noncompliance and interpersonal/social categories were significantly predictive as dependent variables. For models predicting content categories from family member characteristics, only the resources/benefits model was predictive. The significant findings, in conjunction with the important negative results, suggest implications for further development of family intervention models. Building on previous research, groups composed of families coping with more than a single diagnosis and including a variety of family member relationships have the potential to reach consensus on curriculum topics.
Relational Narratives of the Self*
Authors: Fishbane Mona DeKoven
Published: May 2004

The prevailing view of the self in contemporary Western culture is of the autonomous, separate individual. This article considers shifts toward a more relational view in thinking about the self, in developmental psychology and in therapy, especially family therapy. From diverse perspectives this relational narrative of the self is explored, highlighting relational formulations about autonomy, power, and connection/disconnection. Therapeutic approaches that are grounded in a relational narrative are considered. Finally, this article explores, through clinical vignettes, the impact on individuals and their significant others when they shift to a more relational view of the self in their own lives.
Brief Strategic Family Therapy versus Community Control: Engagement, Retention, and an Exploration of the Moderating Role of Adolescent Symptom Severity*
Authors: Coatsworth J. Douglas , Santisteban Daniel A. , McBride Cami K. , Szapocznik José
Published: May 2004

This study extends a program of research investigating the effectiveness of Brief Strategic Family Therapy to engage and retain families and/or youth in treatment. The study contrasted Brief Strategic Family Therapy (BSFT) with a Community Comparison (CC) condition selected to represent the common engagement and treatment practices of the community; 104 families were randomly assigned to BSFT or CC. Results indicate that families assigned to BSFT had significantly higher rates of engagement (81% vs. 61%) and retention (71% vs. 42%). BSFT was also more effective than CC in retaining more severe cases. Post hoc analyses of treatment effectiveness suggest that BSFT was able to achieve comparable treatment effects despite retaining more difficult cases. We discuss these results from a public health perspective, and highlight the study's contribution to a small but growing body of literature that suggests the benefits of a family‐systems paradigm for engagement and retention in treatment.
Marital Interaction, Family Organization, and Differences in Parenting Behavior: Explaining Variations Across Family Interaction Contexts*
Authors: Johnson Vanessa K.
Published: May 2004

Family systems theories remind us that, in two‐parent families, children encounter their parents in multiple family configurations, including parent‐child dyads and mother‐father‐child triads, or whole families. There are, however, relatively few empirical investigations of differences in parenting behavior which tend to emerge when a dyad is transformed into a whole family unit. Using a sample of 82 families with a kindergarten‐age child, the present study offers support to earlier studies reporting that mothers' and fathers' parenting behavior differs when observed in dyadic and whole family interaction sessions. The present study then turns to examining explanations for these differences in parenting behavior. Limited support was found for the hypothesis that observations of marital interaction are associated with differences in parenting behavior across family interaction contexts. Family level assessment of adaptive organization was found to explain differences in fathers' parenting in the dyad and when the entire family is together, but not differences in mothers' parenting behavior. The clinical and methodological implications of these findings are discussed.
Client Experience of Gender in Therapeutic Relationships: An Interpretive Ethnography*
Authors: Gehart Diane R. , Lyle Randall R.
Published: May 2004

The purpose of this study was to explore clients' experiences of gender in therapeutic relationships in order to inform therapists of critical issues from clients' perspectives. To capture clients' views, the researchers chose an interpretive ethnographic design that used unstructured, collaborative interviews with clients who had worked with both female and male therapists. The interviews were analyzed using procedures developed by Kvale (1996), who emphasizes the importance of including the client's voice in data gathering, analysis, and final presentation. The results were reviewed with the clients to insure accurate presentation of their views. The final results were organized into six themes: client‐therapist connection, male therapists, female therapists, topics discussed, effectiveness, and confounding factors. Researchers discuss the implications of gender‐stereotyped behavior in therapy, the relationship between therapist gender and therapeutic alliance, and recommendations for practicing gender‐sensitive therapy.
Triadic Coordination: An Observational Method for Examining Whether Children Are “Caught in the Middle” of Interparental Discord*
Authors: Westerman Michael A. , Massoff Melinda
Published: May 2004

Triadic coordination refers to how a parent coordinates his or her contributions with the spouse's bids toward their child. This construct provides a basis for studying specifically triadic family interaction processes. In particular, it offers a new approach for examining whether children are “caught in the middle” of marital discord. We conducted an initial, small‐scale study of mother‐father‐child interactions in a structured task in order to pursue the methodological goal of developing an observational procedure for measuring triadic coordination processes. The results suggest that the approach has considerable promise for making a contribution to future research on marital discord and child functioning. We found that processes of triadic coordination can be assessed reliably. Other findings included an interesting pattern of results, which merits further investigation in future studies, concerning relations between whether and how a parent disagreed with or opposed the spouse's bids toward their child, on the one hand, and other measures of family functioning and measures of child functioning, on the other hand.
Counseling and Couple Therapy for Infertile Couples*
Authors: Stammer Heike , Wischmann Tewes , Verres Rolf
Published: May 2004

The article describes a two‐tier, interdisciplinary design for the psychological counseling and therapy of childless couples. It is solution‐ and resource‐oriented and avoids psychopathological ascriptions. Couples are supported in coming to terms with the crisis of a physical disorder and its emotional consequences; they are also aided in developing prospects and options for a future without a biological child. The procedure is explained in detail and provides a model suitable for application at reproduction medicine centers and gynecological and andrological practices. Sample interventions illustrate the therapeutic attitude advocated.
The Death of “Till Death Us Do Part”: The Transformation of Pair‐Bonding in the 20th Century*
Authors: Pinsof William M.
Published: May 2004

During the last half of the 20th century within Western civilization, for the first time in human history, divorce replaced death as the most common endpoint of marriage. In this article I explore the history of this death‐to‐divorce transition, the forces associated with the transition, and what the transition may have revealed about the human capacity for monogamous, lifelong pair‐bonding. The impact and consequences of the transition for the generations that came of age during it and immediately afterwards are examined, with particular attention to the emergence of new, alternative pair‐bonding structures such as cohabitation and nonmarital co‐parenting. The article highlights the inability of the dichotomous marriage‐versus‐being‐single paradigm to encompass the new pair‐bonding structures and the normalizing of divorce. Precepts for a new, more encompassing, veridical and humane pair‐bonding paradigm are presented, and some of their implications for social policy, family law, social science, and couple and family therapy are elaborated.
Marital Research in the 20th Century and a Research Agenda for the 21st Century
Authors: Gottman John M. , Notarius Clifford I.
Published: May 2004

In this article we review the advances made in the 20th century in studying marriages. Progress moved from a self‐report, personality‐based approach to the study of interaction in the 1950s, following the advent of general systems theory. This shift led, beginning in the 1970s, to the rapid development of marital research using a multimethod approach. The development of more sophisticated observational measures in the 1970s followed theorizing about family process that was begun in the decade of the 1950s. New techniques for observation, particularly the study of affect and the merging of synchronized data streams using observational and self‐report perceptual data, and the use of sequential and time‐series analyses produced new understandings of process and power. Research in the decades of the 1980s and 1990s witnessed the realization of many secular changes in the American family, including the changing role of women, social science's discovery of violence and incest in the family, the beginning of the study of cultural variation in marriages, the expansion of the measurement of marital outcomes to include longevity, health, and physiology (including the immune system), and the study of co‐morbidities that accompany marital distress. A research agenda for the 21st century is then described.
Marriage in the 20th Century: A Feminist Perspective
Authors: Rampage Cheryl
Published: May 2004

A defining feature of the 20th century in Western civilization was a profound change in the roles women play in both private and public life. The field of couple therapy was influenced by that change and, to a limited extent, participated in it. I will argue that the field has avoided fully embracing the principles of feminism that generated the social changes in gender and marital roles, settling instead for a more token acknowledgment that gender means something, without wanting to specify what that something is. In responding to the other articles in this issue, I make the case that the connection between gender and power in marriage needs to be more fully integrated, in the theory, research, and treatment of couples.
African American Marriage in the 20th Century*
Authors: Pinderhughes Elaine B.
Published: May 2004

It is not possible to understand African American marriages fully without attention to the social, economic, racial, and historical factors that have stressed male—female relationships beyond those stresses experienced by majority couples. I propose that the societal projection process (Bowen, 1978) has entrapped African Americans in ways that have continually and severely strained their marital and couple relationships. These experiences, and the ways in which African Americans have responded to them, have created a vulnerability that is compounded by societal shifts and changes, and is manifest in the precipitous decline of marriages at a rate higher than that found in all other racial groups in the U.S. I will examine the state of African American marriages in this cultural context, with specific attention to the effects of the unequal sex ratio, socioeconomic conditions, and overstressed male—female relationships. I will then discuss implications and offer suggestions for therapists who work with this population.
The Network Perspective: An Integration of Attachment and Family Systems Theories*
Authors: Kozlowska Kasia , Hanney Lesley
Published: May 2004

In this article we discuss the network paradigm as a useful base from which to integrate attachment and family systems theories. The network perspective refers to the application of general systems theory to living systems, and provides a framework that conceptualizes the dyadic and family systems as simultaneously distinct and interconnected. Network thinking requires that the clinician holds multiple perspectives in mind, considers each system level as both a part and a whole, and shifts the focus of attention between levels as required. Key epistemological issues that have hindered the integration of the theories are discussed. These include inconsistencies within attachment theory itself and confusion surrounding the theoretical conceptualizations of the relationship between attachment and family systems theories. Detailed information about attachment categories is provided using the Dynamic Maturational model. Case vignettes illustrating work with young children and their families explore the clinical implications of integrating attachment data into family therapy practice.
Family Systems Theory, Attachment Theory, and Culture*
Authors: Rothbaum Fred , Rosen Karen , Ujiie Tatsuo , Uchida Nobuko
Published: May 2004

Family systems theory and attachment theory have important similarities and complementarities. Here we consider two areas in which the theories converge: (a) in family system theorists' description of an overly close, or “enmeshed,” mother‐child dyad, which attachment theorists conceptualize as the interaction of children's ambivalent attachment and mothers' preoccupied attachment; (b) in family system theorists' description of the “pursuer‐distance cycle” of marital conflict, which attachment theorists conceptualize as the interaction of preoccupied and dismissive partners. We briefly review family systems theory evidence, and more extensively review attachment theory evidence, pertaining to these points of convergence. We also review cross‐cultural research, which leads us to conclude that the dynamics described in both theories reflect, in part, Western ways of thinking and Western patterns of relatedness. Evidence from Japan suggests that extremely close ties between mother and child are perceived as adaptive, and are more common, and that children experience less adverse effects from such relationships than do children in the West. Moreover, in Japan there is less emphasis on the importance of the exclusive spousal relationship, and less need for the mother and father to find time alone to rekindle romantic, intimate feelings and to resolve conflicts by openly communicating their differences. Thus, the “maladaptive” pattern frequently cited by Western theorists of an extremely close mother‐child relationship, an unromantic, conflictual marriage characterized by little verbal communication and a peripheral, distant father, may function very differently in other cultures. While we believe that both theories will be greatly enriched by their integration, we caution against the application of either theory outside the cultures in which they were developed.
Attachment Security in Couple Relationships: A Systemic Model and Its Implications for Family Dynamics
Authors: Mikulincer Mario , Florian Victor , Cowan Philip A. , Cowan Carolyn Pape
Published: May 2004

Theory and research on adult attachment style emphasize the crucial role that the sense of attachment security plays in the formation and maintenance of couple relationships. In the present article, we review studies that have examined the contribution of adult attachment style to relational cognitions, emotions, and behaviors as well as to the formation, quality, and stability of dating and marital relationships. We discuss some of the measurement and design issues raised by this research. Based on the reviewed findings, we provide an integrative, systemic theoretical model delineating how the links between partners' attachment security and the quality of their couple relationship occurs. Finally, we discuss the implications of this model for the understanding of how attachment style and couple relationships combine to affect the family system in general, and parent‐child relationships and children's developmental outcomes, in particular.
Attachment and Family Therapy: Clinical Utility of Adolescent‐Family Attachment Research*
Authors: Liddle Howard A. , Schwartz Seth J.
Published: May 2004

The divide separating research and clinical work is narrowing. New therapies have been informed by research from specialties such as developmental psychology and developmental psychopathology. In this article, we attempt to illustrate the usefulness of research on attachment relations for family‐based therapy with adolescents. We examine the clinical utility of adolescent attachment research within the context of multidimensional family therapy, an empirically supported treatment model that has incorporated developmental research, including basic research on attachment, in its assessment and intervention framework.
Attachment and Affect Regulation: A Framework for Family Treatment of Conduct Disorder*
Authors: Keiley Margaret K.
Published: May 2004

Conduct disorder (CD), a pervasive adolescent disorder with clinically significant antisocial behaviors, has been a difficult syndrome to treat successfully. Recently, research on affect regulation and attachment has suggested that attachment and affect regulation strategies may underlie the development of conduct disorder in adolescents, implying that attention to these factors might improve family treatment for CD. In this review of the research literature, I discuss the role of attachment and affect regulation in the development and treatment of CD. In addition, I present information about the framework, intervention protocol, and preliminary evidence of effectiveness of an attachment‐ and affect regulation‐based intervention that has been developed and implemented with multiple‐family groups of parents and incarcerated adolescents.
Links between Community Violence and the Family System: Evidence from Children's Feelings of Relatedness and Perceptions of Parent Behavior*
Authors: Lynch Michael , Cicchetti Dante
Published: May 2004

In this study, we examined some of the ways in which broader ecological systems may influence the organization of behavior within the family system. Specifically, links between exposure to community violence and children's relationships with maternal caregivers were investigated in a sample of 127 urban children between the ages of 7 and 13 years. Children were asked to indicate whether they had been exposed to a wide variety of violent events. In addition, their feelings of relatedness and separation anxiety, and their perceptions of maternal behavior were assessed. It was expected that exposure to community violence would be associated with feeling less secure with caregivers. Consistent with predictions from ecological‐transactional theory, data supported this hypothesis. Children who reported that they had been exposed to high levels of community violence also indicated that they felt less positive affect when with their caregiver, were dissatisfied with how close they felt to her, felt more separation anxiety, and reported more negative maternal behavior than children exposed to less violence. Findings are discussed in terms of how violence may affect the family system and the protective function of human attachment.
Family Predictors of Antisocial Behavior in Adolescence
Authors: Deković Maja , Janssens Jan M. A. M. , Van As Nicole M. C.
Published: May 2004

The goal of the present study was to examine the combined and unique ability of different aspects of family functioning to predict involvement in antisocial behavior in a large nonclinical (community) sample of adolescents. Distinction was made between global (e.g., family socio‐economic status), distal (dispositional characteristics of parents), contextual (family characteristics), and proximal (parent‐child interaction) factors that operate within families. Results show that proximal factors were significant predictors of antisocial behavior, independent of their shared variance with other factors. Consistent with the hypothesized mediational model, the effects of distal and contextual factors appear to be mostly indirect: after their association with proximal factors was taken into account, these factors were no longer significantly related to antisocial behavior. The implications of these findings for planning of developmentally appropriate interventions for ado‐lesents and their families are discussed.
Love: An Important Dimension in Marital Research and Therapy
Authors: Riehl‐Emde Astrid , Thomas Volker , Willi Jürg
Published: May 2004

How do men and women describe and assess their relationship? What themes are decisive for its quality and stability? To answer such questions, we investigated a random sample of 204 married couples (reference sample), and 31 married couples undergoing psychotherapy (clinical sample) using a newly developed questionnaire. The participating couples were asked to evaluate a total of 19 themes with respect to their importance for the couple's connectedness. Although only rarely directly addressed in couple therapy and in‐vestigated in couple research, the theme “Love” proved to be the decisive factor for quality and stability. The results of the present study, therefore, indicate that “Love” should be investigated more thoroughly in couple research and included more actively in diagnostic and therapeutic procedures.
Adjustment to Divorce: A Preliminary Study among Muslim Arab Citizens of Israel
Authors: Cohen Orna , Savaya Rivka
Published: May 2004

Adjustment to divorce in a sample of 312 Muslim Arab citizens of Israel was associated both with variables that have been shown to affect adjustment to divorce in Western societies and with variables specific to the culture of the study. The former included male gender, education, current employment, fewer accompanying stressors, and greater satisfaction with the divorce process. The latter were the respondents' self‐defined modernity (as op‐posed to traditionalism) and their disinclination to perceive divorced persons as bad parents and spouses and as socially deviant, in accord with the social stereotype of their community.
A relationship between cerebellar Purkinje cells and spatial working memory demonstrated in a lurcher/chimera mouse model system
Authors: Martin L. A. , Escher T. , Goldowitz D. , Mittleman G.
Published: May 2004

New emphasis has been placed upon cerebellar research because of recent reports demonstrating involvement of the cerebellum in non‐motor cognitive behaviors. Included in the growing list of cognitive functions associated with cerebellar activation is working memory. In this study, we explore the potential role of the cerebellum in spatial working memory using a mouse model of Purkinje cell loss. Specifically, we make aggregation chimeras between heterozygous lurcher (Lc/+) mutant embryos and +/+ (wildtype) embryos and tested them in the delayed matching‐to‐position (DMTP) task.Lc/+ mice lose 100% of their Purkinje cells postnatally due to a cell‐intrinsic gain‐of‐function mutation.Lc/+<−>+/+ chimeras therefore have Purkinje cells ranging from 0 to normal numbers. Through histological examination of chimeric mice and observations of motor ability, we showed that ataxia is dependent upon both the number and distribution of Purkinje cells in the cerebellum. In addition, we found thatLc/+ mice, with a complete loss of Purkinje cells, have a generalized deficit in DMTP performance that is probably associated with their motor impairment. Finally, we found thatLc/+<−>+/+ chimeric mice, as a group, did not differ from control mice in this task. Rather, surprisingly, analysis of their total Purkinje cells and performance in the DMTP task revealed a significant negative relationship between these two variables. Together, these findings indicate that the cerebellum plays a minor or indirect role in spatial working memory.
General practice encounters with older Australians
Authors: O'Halloran Julie , Britt Helena
Published: May 2004

Objectives: To describe the content of general practitioners’ (GP) encounters with patients aged 65 years or more, and to determine any differences in the way problems are managed between the 65–74 and 75 years and over age groups.

Method: A secondary analysis of data collected through the Bettering the Evaluation and Care of Health (BEACH) program was carried out.

Results: Encounters with older patients accounted for 25.0% of a GP's total workload. Circulatory conditions, in particular hypertension, were the most frequently managed, with cardiovascular medications the most frequently prescribed. Numerous differences exist in the characteristics and management of older patients when divided into those aged 65–74 and 75 years and over, with patients aged 75 years or more receiving investigations and non‐pharmacological treatments significantly less often.

Conclusion: The present study provides a baseline measure of the management of older patients in general practice.
Low prevalence of skin diseases among patients in a Japanese nursing home
Authors: Smith Derek R. , Kubo Hiroyoshi , Yamagata Zentaro
Published: May 2004

Although increasing numbers of the elderly Japanese reside in nursing homes, few epidemiological studies on skin diseases have been undertaken. We studied this issue in 135 nursing home residents in Yamanashi prefecture, central Japan. Approximately two‐thirds of participants were female (65.9%), with dementia (42.2%), stroke (38.5%) and heart disease (34.1%) being the most common underlying conditions. Age ranged from 50 to 98 years, with an average of 78.6 years. Total duration of stay within the nursing home ranged from 13 to 44 months, with an average stay of 21.7 months, or approximately 1.8 years. Approximately 1 in 12 participants were bedridden (8.1%). Fungal infection (including candida, tinea manum, tinea pedis and tinea unguium) was the most common condition (4.4%), followed by dermatitis (1.5%) and senile xerosis (1.5%). Overall, the prevalence of skin disease was considerably lower than in previous international reports, possibly due to a ‘healthy‐patient effect’. Further research needs to be undertaken to elucidate the overall prevalence of skin disease among Japanese nursing home residents.
Vitamin D deficiency and secondary hyperparathyroidism in older people with low trauma fractures
Authors: Hii Susanna , Scherer Sam
Published: May 2004

Objectives: To determine the prevalence of vitamin D deficiency and hyperparathyroidism in older patients with low trauma fractures, and to develop a statistical model to predict the serum level of 25‐hydroxyvitamin D required to prevent secondary hyperparathyroidism.

Method: Descriptive cohort study conducted in an aged care centre in Melbourne, Australia. Participants comprised 107 patients aged over 65 years with low trauma fractures. Serum 25‐hydroxyvitamin D (25OHD), parathyroid hormone (PTH) and plasma creatinine levels were measured. Anthropometric data, Barthel index, Mini‐Mental State Examination and use of diuretics were also assessed.

Results: Fifty‐one per cent of patients had 25OHD <30 nmol/L and 86% had 25OHD <50 nmol/L. Thirty‐two per cent had secondary hyperparathyroidism which was significantly associated with vitamin D deficiency and use of frusemide. Statistical models demonstrated higher PTH at serum 25OHD below 60 nmol/L.

Conclusions: Vitamin D deficiency is common among older people. Serum 25OHD may need to be greater than 60 nmol/L to prevent secondary hyperparathyroidism.
Risk factors for and prediction of falls in an acute aged care psychiatry unit
Authors: Draper Brian , Busetto Giselle , Cullen Breda
Published: May 2004

Objectives: To evaluate the predictive value of the Aged Care Psychiatry Unit (ACPU) Falls Screen and to describe the outcomes associated with falls in an acute aged care psychiatry unit.

Methods: The development of the ACPU Falls Screen for use in an acute aged care psychiatry unit is described. Consecutive admissions to an acute aged care psychiatry unit were assessed prospectively with the ACPU Falls Screen, Health of the Nation Outcomes Scale for older persons (HoNOS 65+) and the Resource Utilisation Groups Activities of Daily Living (RUG ADL) Scale. Details of all falls and their consequences were documented on a falls incident form. Other information, extracted from medical records, included psychiatric and medical diagnoses, psychotropic medication prescription, electroconvulsive therapy (ECT), length of stay and demographic data. Multiple logistic regression was used to examine putative predictors of falls.

Results: Ninety‐five admissions were included in the sample, of which 28 (29%) had falls. Multiple falls occurred in 16% of admissions. No serious injuries were recorded. Falls were associated with significantly higher scores on the ACPU Falls Screen, behavioural overactivity and recent receipt of ECT. However, falls were not associated with significant differences in psychiatric outcome, although multiple falls were associated with an increased length of stay. Receiver operating characteristic (ROC) curves for the ACPU Falls Screen indicated it had poor predictive value for falls.

Conclusions: Falls are common in acute aged care psychiatry units. The ACPU Falls Screen was not a good predictor of falls. Universal precautions should be taken to prevent falls, particularly after ECT and in admissions with behavioural overactivity.
Closely Spaced Circular Cylinders in Cross-Flow and a Universal Wake Number
Authors: Sumner David
Published: May 2004

To investigate the effectiveness of a universal wake number for groups of closely spaced bluff bodes, staggered cylinder configurations with center-to-center pitch ratios of P/D=1.125 and 1.25, and incidence angles from α=0 deg–90 deg, were tested in the subcritical Reynolds number regime. The aerodynamic forces, base pressure, and vortex shedding frequencies were measured for the upstream and downstream cylinders, and were found to be strongly dependent on the incidence angle and small changes in the flow pattern. The Griffin number was found to be an appropriate universal wake number for the closely spaced staggered cylinders, based on the total drag force acting on the two cylinders, and the average base pressure for the two cylinders. The results suggest that the single vortex wake of a pair of closely spaced staggered cylinders is broadly comparable to the wake of a solitary bluff body, and that the universal wake number concept can be extended to groups of closely spaced bluff bodies.
Flow Rate Measurements Using Flow-Induced Pipe Vibration
Authors: Evans Robert P. , Blotter Jonathan D. , Stephens Alan G.
Published: May 2004

This paper investigates the possibility of developing a nonintrusive, low-cost, flow-rate measurement technique. The technique is based on signal noise from an accelerometer attached to the surface of the pipe. The signal noise is defined as the standard deviation of the frequency-averaged time-series signal. Experimental results are presented that indicate a nearly quadratic relationship over the test region between the signal noise and flow rate in the pipe. It is also shown that the signal noise–flow rate relationship is dependent on the pipe material and diameter.
The Effect of Wake Passing on a Flow Separation in a Low-Pressure Turbine Cascade
Authors: Brear Michael J. , Hodson Howard P.
Published: May 2004

This paper describes an investigation into the effect that passing wakes have on a separation bubble that exists on the pressure surface and near the leading edge of a low-pressure turbine blade. Previous experimental studies have shown that the behavior of this separation is strongly incidence dependent and that it responds to its disturbance environment. The results presented in this paper examine the effect of wake passing in greater detail. Two-dimensional, Reynolds averaged, numerical predictions are first used to examine qualitatively the unsteady interaction between the wakes and the separation bubble. The separation is predicted to consist of spanwise vortices whose development is in phase with the wake passing. However, comparison with experiments shows that the numerical predictions exaggerate the coherence of these vortices and also overpredict the time-averaged length of the separation. Nonetheless, experiments strongly suggest that the predicted phase locking of the vortices in the separation onto the wake passing is physical.
Effects of Surface Roughness and Turbulence Intensity on the Aerodynamic Losses Produced by the Suction Surface of a Simulated Turbine Airfoil
Authors: Zhang Qiang , Lee Sang Woo , Ligrani Phillip M.
Published: May 2004

The effects of surface roughness on the aerodynamic performance of turbine airfoils are investigated with different inlet turbulence intensity levels of 0.9%, 5.5% and 16.2%. Three symmetric airfoils, each with the same shape and exterior dimensions, are employed with different rough surfaces. The nonuniform, irregular, 3-D roughness is characterized using the equivalent sand grain roughness size. Mach numbers along the airfoil range from 0.4 to 0.7. Chord Reynolds numbers based on inlet and exit flow conditions are 0.54×106 and 1.02×106, respectively. The contributions of varying surface roughness and turbulence intensity level to aerodynamic losses, Mach number profiles, normalized kinetic energy profiles, and Integrated Aerodynamics Losses (IAL) are quantified. Results show that effects of changing the surface roughness condition on IAL values are substantial, whereas the effects of different inlet turbulence intensity levels are generally relatively small.
Determination of Flow Rate Characteristics of Pneumatic Solenoid Valves Using an Isothermal Chamber
Authors: Kawashima Kenji , Ishii Yukio , Funaki Tatsuya , Kagawa Toshiharu
Published: May 2004

In this paper, two new methods for obtaining the sonic conductance and the critical pressure ratio of pneumatic valves are proposed. Both methods use a chamber that can approximate isothermal conditions. This was achieved by filling the chamber with metal wire, which creates a larger heat transfer area and heat transfer coefficient. The sonic conductance and the critical pressure ratio are obtained by measuring the pressure in the chamber during charging and discharging. These methods take only seconds to perform and require less energy than the ISO 6358 procedure. The major factor in the error for the pressure response during the charging of the isothermal chamber is the upstream pressure change. Nevertheless, the sonic conductance can be determined within a 3% uncertainty. In addition, the sonic conductance calculated from the pressure response during the discharging of the chamber can be determined within a 1.2% uncertainty.
Rheology of Dilute Polymer Solutions and Engine Lubricants in High Deformation Rate Extensional Flows Produced by Bubble Collapse
Authors: Barrow M. S. , Brown S. W. J. , Cordy S. , Williams P. R. , Williams R. L.
Published: May 2004

We report a study of liquid jets formed by the collapse of bubbles under cavitation-generated pressure waves. Such jets involve an extensional flow which is characterized by high rates of extension, the latter being relevant to considerations of the flow of oils within dynamically loaded journal bearings. The technique reported here is found to be sensitive to the influence of extremely small concentrations of high molecular weight polymeric additive (xanthan gum). Commercial multigrade oils are also found to exhibit significantly larger resistance to extensional flow than their Newtonian counterparts and, insofar as the multigrade oils studied here are made viscoelastic by polymer additives, and possess significant levels of resistance to extension, the results provide evidence in support of a mitigating effect of viscoelasticity on cavitation, as mooted by Berker et al. [3].
Torque Measurements in Spin-Up Flow of Ferrofluids
Authors: Rosenthal Adam D. , Rinaldi Carlos , Franklin Thomas , Zahn Markus
Published: May 2004

Measurements of magnetic-field-induced torque in applied uniform rotating magnetic fields are presented and compared to theoretical analyses for water- and oil-based ferrofluids. These experiments measure the viscous torque on the inner wall of a stationary hollow polycarbonate spindle that is completely filled with ferrofluid and attached to a viscometer functioning as a torque meter. The spindle remains stationary and is centered inside a three-phase AC 2-pole motor stator winding, creating uniform time-varying rotating magnetic fields. The viscous torque is measured as a function of magnetic field amplitude, frequency, and direction of rotation. These measurements demonstrate that ferrofluid flow and torque are present even in the absence of free surfaces and agree with a recently derived analysis of the torque during spin-up flow of ferrofluids.
A Kinetic Theory for Solutions of Nonhomogeneous Nematic Liquid Crystalline Polymers With Density Variations
Authors: Wang Qi , Forest M. Gregory , Zhou Ruhai
Published: May 2004

The kinetic theory developed in [1] for solutions of nonhomogeneous nematic liquid crystalline polymers (LCPs) of spheroidal molecular configurations is extended to account for the translational diffusion and the related spatial density variation. The new theory augments the effect of the density variation to the intermolecular potential, Smoluchowski equation and the elastic stress. It accounts for the molecular aspect ratio as well as the finite range molecular interaction so that it is applicable to liquid crystals ranging from rodlike liquid crystals at large aspect ratios to discotic ones at small aspect ratios. It also exhibits enhanced shape effects in the viscous stress and warrants a positive entropy production, thereby, the second law of thermodynamics. Moment averaged, approximate, mesoscopic theories for complex flow simulations are obtained via closure approximations. In the limit of weak distortional elasticity, weak translational diffusion, and weak flows, the theory yields the torque balance equation of the well-known Ericksen-Leslie theory.
Use of Resin Transfer Molding Simulation to Predict Flow, Saturation, and Compaction in the VARTM Process
Authors: Correia N. C. , Robitaille F. , Long A. C. , Rudd C. D. , Sˇima´cˇek P. , Advani S. G.
Published: May 2004

The present paper examines the analysis and simulation of the vacuum assisted resin transfer molding process (VARTM). VARTM differs from the conventional resin transfer molding (RTM) in that the thickness of the preform varies during injection affecting permeability and fill time. First, a governing equation for VARTM is analytically developed from the fundamental continuity condition, and used to show the relation between parameters in VARTM. This analytical work is followed by the development of a numerical 1-D/2-D solution, based on the flow simulation software LIMS, which can be used to predict flow and time dependent thickness of the preform by introducing models for compaction and permeability. Finally, the results of a VARTM experimental plan, focusing on the study of the influence of outlet pressure on compaction and fill time, are correlated with both the analytical and the numerical work. The present work also proposes an explanation for the similarities between VARTM and RTM and shows when modeling VARTM and RTM can result in an oversimplification.
Rheological Properties and Frictional Pressure Loss of Drilling, Completion, and Stimulation Fluids in Coiled Tubing
Authors: Zhou Yunxu , Shah Subhash N.
Published: May 2004

The rheological properties and friction pressure losses of several common well-drilling, completion, and stimulation fluids have been investigated experimentally. These fluids include polymeric fluids—Xanthan gum, partially hydrolyzed polyacrylamide (PHPA), guar gum, and hydroxyethyl cellulose (HEC), bentonite drilling mud, oil-based drilling mud, and guar-based fracturing slurries. Rheological measurements using a Bohlin CS 50 rheometer and a model 35 Fann viscometer showed that these fluids exhibit shear thinning and thermal thinning behavior except the bentonite drilling mud whose viscosity increased as the temperature was raised. Flow experiments using a full-scale coiled tubing test facility showed that the friction pressure loss in coiled tubing is significantly higher than in straight tubing. Since the polymeric fluids displayed drag reducing property, their drag reduction behavior in straight and coiled tubings was analyzed and compared. Plots of drag reduction vs. generalized Reynolds number indicate that the drag reduction in coiled tubing was not affected by polymer concentration as much as in straight tubing. The onsets of turbulence and drag reduction in coiled tubing were significantly delayed as compared with straight tubing. The effect of solids content on the friction pressure losses in coiled tubing is also briefly discussed.
Macroscopic Effects of Surface Roughness in Confined Air Flow
Authors: Boutaous M’hamed , Bourgin Patrick
Published: May 2004

The general framework deals with the winding of thin plastic films, in order to obtain good-quality rolls. This issue is tightly connected to the thickness of the residual air layer entrapped between the film layers. It is then of importance to optimize the surface topography of the films so that to improve the quality of the wound rolls. In a previous work, we proposed a simple model for the flow of an air layer squeezed between a solid smooth substrate and a plastic film sample: it was shown experimentally that the macroscopic characteristics of the flow are connected to the film roughness, but how? In order to answer this question, we assimilated the confined air flow to a flow through a periodic array of cylinders and a mathematical model based on homogenization techniques was developed. In the present paper, we search for pertinent parameters which describe the real surface roughness of plastic films. The experiments were carried out by using a 3-D roughness measurement device and the first observation is that the roughness distribution is not uniform. We made a sampling expressed by the percentage of peaks exceeding some given height threshold. The corresponding experimental parameters are used to define the network of cylinders. For each type of film, the threshold value is the only adjustable parameter and the following results are obtained: It is possible to adjust this parameter so that to obtain a very good agreement between the experimental data and the theoretical predictions. In addition, the smoother the film, the more important the highest peaks are in terms of air leakage.
Buoyancy Convection During the Growth of SixGe1−x by the Traveling Solvent Method (TSM)
Authors: Saghir M. Z. , Makriyannis T. J. , Labrie D.
Published: May 2004

The traveling solvent method known as TSM is a process used to produce pure and homogeneous crystals structures. TSM has been tested on many alloys producing uniform and uncontaminated single crystals. In the present study the effect of buoyancy convection on the growth of the Si0.02Ge0.98 crystal grown by the traveling solvent method is investigated under different heating conditions. The full Navier-Stokes equations together with the energy and solutal equations are solved numerically using the finite element technique. The model takes into consideration the losses of heat by radiation and the use of the phase diagram to determine the silicon concentration at the growth interface. Results reveal a strong convection in the solvent, which in turn is detrimental to the growth uniformity in the crystal rod. Additional numerical results show that the convective heat transfer significantly influences the solute distribution in the liquid zone and affects the growth rate substantially. Qualitative comparison of the numerical results with the experiment conducted at Dalhousie University showed a good agreement for the silicon concentration at the growth interface.
Numerical Modeling of Formation of High-Speed Water Slugs
Authors: Petrenko O. , Geskin E. S. , Atanov G. A. , Semko A. , Goldenberg B.
Published: May 2004

The objective of this work is to investigate acceleration of a water slug by the powder explosion. The process occurs in a device termed the water cannon, which entails a barrel with an attached nozzle. The explosion products expel the slug from the barrel at an extremely high speed. Due to the acceleration in the nozzle the speed of the slug significantly exceeds that of a bullet driven by the similar explosion. The computational procedure was used to evaluate the pressure, velocity and density fields in the course of slug acceleration in the x-t space. The procedure is based on the finite difference method and the method of characteristics. The initial water velocity and pressure are assumed to be zero. The pressure at water-explosion product interface is determined by the conditions of the powder combustion while the pressure at the water-atmosphere interface is equal to zero. The results of the computations enable us to explain the peculiarities of the operation of the water cannon and to optimize device design.
Fraction Solid Measurements on Solidifying Melt
Authors: Bakhtiyarov Sayavur I. , Overfelt Ruel A. , Teodorescu Sorin G.
Published: May 2004

A new indirect method to measure fraction solid in molten metals is presented. The method is based on the phenomena that when a metal sample (solid or liquid) rotates in a magnetic field (or the magnetic field rotates around a stationary sample), circulating eddy currents are induced in the sample, which generate an opposing torque related to amount of solid phase in a solidifying melt between the liquidus and solidus temperatures. This new technique is applied for measuring fraction solid on commercial A319 aluminum alloy. The solidification curves obtained by the proposed method at different cooling rates are in good agreement with predictions made by the Scheil model.
Self-Calibrating Sensor for Measuring Density Through Stainless Steel Pipeline Wall
Authors: Greenwood Margaret S. , Bamberger Judith A.
Published: May 2004

An ultrasonic instrument to measure the density of a liquid or slurry through a stainless steel pipeline wall is described. By using multiple reflections of the ultrasound within the stainless steel wall, the acoustic impedance (defined as the product of the density of the liquid and the velocity of sound in the liquid) is determined. Thus, the wall is part of the measurement system. The density is obtained by coupling the acoustic impedance measurement with a velocity of sound measurement. By basing the measurement on multiple reflections, instrument sensitivity is increased by the power of the reflection coefficient. The measurement method is self-calibrating because the measurement of the acoustic impedance is independent of changes in the pulser voltage. Data are presented over a range of pulser voltages for two wall thicknesses. These results can be applied to develop an ultrasonic sensor that (1) can be attached permanently to a pipeline wall, possibly as a spool piece inserted into the line or (2) can clamp onto an existing pipeline wall and be movable to another location. The self-calibrating feature is very important because the signal strength is sensitive to the pressure on the clamp-on sensor. A sensor for immersion into a tank could also be developed.