bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategies for Obtaining Parental Consent to Participate in Research*
Authors: Fletcher Anne C. , Hunter Andrea G.
Published: February 2004

Researchers recruiting samples of children through schools typically face considerable challenges in obtaining completed consent forms from parents. Because children whose parents do not return consent forms are not able to participate in research, parental nonresponse is a primary factor contributing to nonrepresentative samples. In this article, we describe a set of procedures used to obtain active parental consent for child participation that resulted in a 95% return rate of consent forms. Rates of return were similar across schools that varied according to both racial and socioeconomic composition.
Development of the Attitudes About Romance and Mate Selection Scale*
Authors: Cobb Nathan P. , Larson Jeffry H. , Watson Wendy L.
Published: February 2004

The 32‐item Attitudes About Romance and Mate Selection Scale (ARMSS) was developed to measure constraining beliefs about mate selection. Using factor analysis, seven factors were identified roughly corresponding to Larson's (1992) constraining beliefs about mate selection. The final instrument consisted of four distractor items to help disguise the nature of the instrument plus 28 items on seven subscales: (a) One and Only, (b) Love Is Enough, (c) Cohabitation, (d) Complete Assurance, (e) Idealization, (f) Ease of Effort, and (g) Opposites Complement. Reliability and validity evidence was demonstrated. Results showed few gender differences in the degree to which constraining beliefs about mate selection are held by single young adults. However, significant differences were found when age, religious affiliation, and ethnicity were considered. Implications for using the ARMSS in premarital counseling and education are discussed.
Coparenting Quality: Contributions of Child and Parent Characteristics
Authors: Stright Anne Dopkins , Bales Stephanie Stigler
Published: February 2004

Child gender, age, and temperament; parents' personality and education; and coparenting quality in the parents' families of origin were used to predict the quality of coparenting during family interactions (father, mother, and preschool child). Forty Midwestern, predominantly White families participated in the study. Families with college‐educated mothers had high levels of supportive coparenting during family interactions regardless of the quality of coparenting in the mother's family of origin. In contrast, in families with high school–educated mothers, the more supportive the coparenting relationship in the mother's family of origin had been, the more supportive the couple was during the current family interaction. Couples with less educated and adjusted mothers were likely to be unsupportive during the family interaction.
Determinants of Parental Stress in Families Adopting Children From Eastern Europe*
Authors: Judge Sharon
Published: February 2004

Sources of variation in parents' assessment of parental stress and the effects of early institutionalization were investigated. Participants included 109 mother‐father pairs who adopted children from Eastern Europe. Significant differences between mothers and fathers were obtained on child‐ and parent‐related stress. The direction and magnitude of the differences between parents varied by the individual scale. Results indicated that children's behavior problems were highly associated with parenting stress for both mothers and fathers.
Demand, Support, and Perception in Family‐Related Stress Among Protestant Clergy
Authors: Lee Cameron , Iverson‐Gilbert Judith
Published: February 2004

Studies of clergy have emphasized the effects of stressors inherent to the profession and the impact of these on the minister's personal and family life.Hill's (1949)ABC‐X model of family stress was employed to extend the focus to include three classes of variables: demands, social support, and perception. Results of questionnaires from a random sample of 312 Protestant clergy indicated that perception variables are more consistently correlated with outcome than were either demand or support.
Risk and Protective Factors in Young Children's Adjustment to Parental Divorce: A Review of the Research
Authors: Leon Kim
Published: February 2004

This article reviews the literature on parental divorce and early childhood development, using developmental psychopathology as an organizing framework. With respect to young children, three questions are addressed: How does parental divorce affect developmental outcomes? What risk and protective factors influence adaptation? How does early parental divorce affect later adjustment? Because this review is unique in its focus on divorce‐related issues specific to young children, limitations of existing research are noted and directions for future research are suggested.
Multi‐Level Determinants of Mothers' Engagement in Home Visitation Services*
Authors: McGuigan William M. , Katzev Aphra R. , Pratt Clara C.
Published: February 2004

A two‐level hierarchical linear model was used to investigate the impact of poor community health and maternal isolation on mothers' active engagement in a home‐visiting family support program. Data came from 4,057 mothers with firstborn infants who enrolled in the Oregon Healthy Start (OHS) home‐visiting program from 1995 through 1998. At the time of this study OHS operated in 15 Oregon counties. Results showed that if the mother was living in a county that displayed poor community health, or if the mother was isolated from immediate family and friendship networks, the likelihood of actively engaging in home visits was significantly reduced. Implications for programming and study limitations are discussed.
Military Families Under Stress: Implications for Family Life Education*
Authors: Drummet Amy Reinkober , Coleman Marilyn , Cable Susan
Published: February 2004

We provide a summary of the limited research on three uniquely stressful experiences of military families: relocation, separation, and reunion. Using the insights derived from this literature, we identify and discuss interventions to assist and guide military families through these unique events.
Voices From the System: A Qualitative Study of Foster Children's Stories
Authors: Whiting Jason B. , Lee Robert E.
Published: February 2004

This project qualitatively analyzed the stories that 23 preadolescent foster children told about their lives. An ecological framework in conjunction with the social constructionist understanding of stories guided the ethnographic semistructured interviews. These stories contained both common and unique features and provided insight into the lives of foster children whose environments involved poverty, drugs, crime, violence, and racism. Research domains included confusion, social ambivalence, anger, loss, and aids to resiliency. This study highlights the importance of these stories for the children who create them and those who will work with them.
Examining Risk Factors Associated With Family Reunification for Runaway Youth: Does Ethnicity Matter?
Authors: Thompson Sanna J. , Kost Kathleen A. , Pollio David E.
Published: February 2004

This study investigated the likelihood of family reunification across ethnic groups of 14,419 youth using runaway shelter services nationwide. Among White, African American, Hispanic, Native American, and Asian ethnic groups, youths who reported abuse or neglect by their parental figures or had parent(s) who were unemployed were less likely to reunify following a runaway episode. However, completing youth shelter services markedly increased the likelihood of reunification. Implications for cultural sensitivity in service delivery, particularly regarding family issues, are discussed.
Family Theory Versus the Theories Families Live By
Authors: Daly Kerry
Published: February 2004

I argue that there is significant disjunction between the way that families live their lives and the way that we theorize about families. Using the metaphor of positive and negative spaces from the art world, I argue that there are many negative spaces in our theorizing—everyday family activities that take up considerable time, energy, and attention but that are poorly represented in our theorizing about families. Specifically, there are three negative spaces that call out for more attention, including the realm of spirituality, emotions, and myths; activities related to consumption; and time and space.
Toward a Dialectical Model of Family Gender Discourse: Body, Identity, and Sexuality
Authors: Blume Libby Balter , Blume Thomas W.
Published: February 2004

The goal of this article is to propose a dialectical model representing gender discourse in families. A brief review of literature in sociology, psychology, and gender studies focuses on three dialectical issues: nature versus culture, similarity versus difference, and stability versus fluidity. Deconstructing gender theories from a postmodern feminist perspective, the authors discuss agency and context in families' gender discourse. Narrative excerpts from interviews with an adolescent daughter and her mother illustrate three emergent themes in the social construction of gender: body, identity, and sexuality. The article concludes with recommendations for family researchers.
Psychological Aggression by American Parents: National Data on Prevalence, Chronicity, and Severity
Authors: Straus Murray A. , Field Carolyn J.
Published: February 2004

This article describes the prevalence of psychological aggression in a nationally representative sample of 991 parents. By child‐age 2, 90% reported using one or more forms of psychological aggression during the previous 12 months and 98% by age 5. From ages 6 to 17, the rates continued in the 90% range. The rate of severe psychological aggression was lower: 10%–20% for toddlers and about 50% for teenagers. Prevalence rates greater than 90% and the absence of differences according to child or family characteristics suggests that psychological aggression is a near universal disciplinary tactic of American parents. Finally, this article discusses the implications of the findings for the conceptualization of psychological “abuse,” and for understanding the origins of the high level of psychological aggression between intimate partners.
Parental Discipline and Abuse Potential Affects on Child Depression, Anxiety, and Attributions
Authors: Rodriguez Christina M.
Published: February 2004

The current study investigated differences in children's emotional functioning as a product of their parents' reported disciplinary practices and child abuse potential. Families with no known history of abuse were recruited to ascertain whether depressogenic attributional style and depressive or anxious symptomatology was evident in children of parents who used harsher physical punishment and who had higher abuse potential. Forty‐two New Zealand children ages 8–12 participated with their parents. Child‐report measures of depression, anxiety, and attributional style were compared with parents' responses on physical discipline scenarios and child abuse potential. Children's anxiety symptoms were higher in those children whose parents obtained higher abuse potential scores and had harsher discipline practices. Children's depressive symptoms and some components of maladaptive attributional style were also found in families with higher abuse potential. Results suggest emotional difficulties similar to those of maltreated children even without identifiable abuse.
Family Life With Children With Disabilities: The Key Role of Rehabilitation
Authors: Rogers Michelle L. , Hogan Dennis P.
Published: February 2004

This study examines the effects of children's medical impairments and functional disabilities and the use of medical care and rehabilitation on three family consequences (job changes, severe financial problems, and sleep disruptions). We use a life course perspective on the interlinked lives of family members, countertransitions, and career contingencies to understand the family impact of child disability. Using data from the 1994 and 1995 National Health Interview Surveys (N= 3,446), we find that the rehabilitation services that children receive account for (mediate) a large part of the observed association of children's medical impairments and disabilities on these family outcomes. Assistance in obtaining rehabilitation for children with disabilities could reduce the family costs and disruptive countertransitions associated with raising children with disabilities.
Influences of Race and Family Environment on Child Hyperactivity and Antisocial Behavior
Authors: Schmitz Mark F.
Published: February 2004

Using data from the National Longitudinal Survey of Youth, latent growth curve modeling was used to examine relationships between trajectories of child hyperactivity and antisocial behavior symptoms for African Americans (n= 680), European Americans (n= 1195), and Hispanics (n= 432). A systematic examination of predictors of, and interrelationships between, these trajectories was tested based on two distinct models of family influences in the development of child behavior problems. Overall, child hyperactivity mediated the effects of family environment on child antisocial behavior, but with key racial differences. The results indicate the importance of conceptualizing patterns of family interaction as adaptive responses to the environment, rather than individual developmental interactions.
Community Context of Social Resources and Adolescent Mental Health
Authors: Wickrama K. A. S. , Bryant Chalandra M.
Published: February 2004

This study investigated cross‐level mediational and moderational community and family influences on adolescent depressive symptoms. Using multilevel data from the National Longitudinal Study of Adolescent Health, we predicted that structural community characteristics such as community poverty and ethnic heterogeneity would influence community social resources, which in turn would influence adolescent depressive symptoms. We further predicted that community social resources would influence adolescent depressive symptoms through family social resources. Findings also suggested that the influence of the parent‐child relationship on adolescent depressive symptoms is weaker in more adverse communities than in less adverse communities. The findings underscore the importance of placing family process models within the community context when adolescent outcomes are investigated.
Daughter‐Father Relationships and Adolescent Psychosocial Functioning in Low‐Income African American Families
Authors: Coley Rebekah Levine
Published: February 2004

This study examines the role of biological and social fathers in the lives of low‐income African American adolescent girls (N= 302). Sixty‐five percent of adolescents identified a primary father; two thirds were biological and one third were social fathers. Adolescents reported more contentious and less close relationships with biological than with social fathers. Multivariate regression analyses indicated that daughters' perceptions of anger and alienation from fathers was related to greater emotional and behavioral problems for adolescents, whereas perceptions of trust and communication with fathers were not predictive of youth outcomes. These relationships were generally similar for biological and social fathers, but differed according to fathers' level of contact with their daughters. A combination of low contact and high levels of either anger or trust in the daughter‐father relationship related to particularly deleterious psychosocial outcomes for adolescent girls.
Adolescent Well‐Being in Cohabiting, Married, and Single‐Parent Families
Authors: Manning Wendy D. , Lamb Kathleen A.
Published: February 2004

Cohabitation is a family form that increasingly includes children. We use the National Longitudinal Study of Adolescent Health to assess the well‐being of adolescents in cohabiting parent stepfamilies (N= 13,231). Teens living with cohabiting stepparents often fare worse than teens living with two biological married parents. Adolescents living in cohabiting stepfamilies experience greater disadvantage than teens living in married stepfamilies. Most of these differences, however, are explained by socioeconomic circumstances. Teenagers living with single unmarried mothers are similar to teens living with cohabiting stepparents; exceptions include greater delinquency and lower grade point averages experienced by teens living with cohabiting stepparents. Yet mother's marital history explains these differences. Our results contribute to our understanding of cohabitation and debates about the importance of marriage for children.
The Well‐Being of Adolescents in Households With No Biological Parents
Authors: Sun Yongmin
Published: February 2004

On the basis of a large, nationally representative sample of 19,071 American middle‐school students, the current study compares adolescents living with neither biological parent with their peers in five other family structures on a wide range of outcome measures. The results reveal some overall disadvantages of living with neither parent, although the disadvantages relative to nontraditional families are limited. Differences in family resources either partially or completely account for outcome differences between non‐biological‐parent and other family structures. Further, boys and girls in non‐biological‐parent families appear to fare similarly. Finally, measurement problems and their implications are discussed.
Income Allocation in Marital and Cohabiting Unions: The Case of Mainland Puerto Ricans
Authors: Oropesa R. S. , Landale Nancy S. , Kenkre Tanya
Published: February 2004

The rise of cohabitation and the growing share of births to cohabiting couples have led to speculation that the boundary between marriage and cohabitation is blurring. We examine this issue with an analysis of the financial arrangements of fathers of mainland Puerto Rican children. The analysis shows that married fathers are more likely than cohabiting fathers to pool their income, but this difference does not result from socioeconomic and demographic factors that foster uncertainty. The analysis also demonstrates that income allocation methods are generally stable over time after differences in union dissolution by allocation method are considered. The discussion emphasizes the need for research on the ways that financial ties reflect and reinforce the bonds between partners.
Does Marriage Increase the Odds of Affluence? Exploring the Life Course Probabilities
Authors: Hirschl Thomas A. , Altobelli Joyce , Rank Mark R.
Published: February 2004

This study estimates the life course incidence and age pattern of affluence among American couples in comparison to nonmarried, never married, and formerly married men and women. Life course probabilities are computed from a series of life tables built upon 25 years of data from the Panel Study of Income Dynamics (N= 8,510 25‐year‐olds; N= 3,481 45‐year‐olds). Results confirm the notion that marriage enhances the lifetime probability of affluence, and that this advantage varies sharply by gender and by race. The study suggests that the marital advantage for gaining affluence is textured by a financial landscape of gender and race inequality.
An Exploratory Investigation of Heterosexual Licensed Domestic Partners
Authors: Willetts Marion C.
Published: February 2004

In‐depth telephone interviews were conducted in four cities in an exploratory study of 23 licensed cohabitors to determine why they have chosen to legitimize their intimate unions through domestic partnership ordinances, rather than through legal marriage. The cohabitors in this sample are pursuing these licensed partnerships to obtain an economic benefit (e.g., health insurance coverage for a partner); as a substitute for legal remarriage; to legitimize their unions in a way other than through legal marriage; or as an ideological alternative to legal marriage. Regardless of motivations to pursue domestic partnership certificates, these respondents are divided over whether they should have the same rights and responsibilities as the married.
Union Formation and Depression: Selection and Relationship Effects
Authors: Lamb Kathleen A. , Lee Gary R. , DeMaris Alfred
Published: February 2004

Many studies have established that married people fare better than their never‐married counterparts in terms of psychological well‐being. It is still unclear, however, whether this advantage is due primarily to beneficial effects of marriage or to the selection of psychologically healthier individuals into marriage. This study employs data on young adults from both waves of the National Survey of Families and Households to test hypotheses based on both selection (N= 878) and relationship (N= 722) effects. Further, we differentiate union formation into cohabitation and marriage with and without prior cohabitation. Results indicate no evidence of selection of less depressed persons into either marriage or cohabitation, but a negative effect of entry into marriage on depression, particularly when marriage was not preceded by cohabitation.
Marital Quality and Spouses' Marriage Work With Close Friends and Each Other
Authors: Helms Heather M. , Crouter Ann C. , McHale Susan M.
Published: February 2004

Through in‐home interviews with 142 married couples, we explored how husbands' and wives' marriage work with close friends and one another was linked to their perceptions of marital quality. Results showed that husbands engaged in more marriage work with their wives than with close friends, whereas wives engaged in similar levels of marriage work with their close friends and husbands. For wives, marriage work with their spouses was found to moderate the relationship between marital quality and marriage work with friends. At low levels of marriage work with their spouses, wives' marriage work with friends was negatively related to their reports of marital love and positively related to reports of ineffective arguing. In contrast, at high levels of marriage work with their husbands, no significant relationship was found between wives' marriage work with friends and marital quality for wives. Findings underscore the role of spouses' friendships and suggest that the strength of spouses' ties to one another is linked to the social context they and their close friends create.
Trait Expressiveness and Marital Satisfaction: The Role of Idealization Processes
Authors: Miller Paul J. E. , Caughlin John P. , Huston Ted L.
Published: February 2004

This study examined the processes that underlie the association between trait expressiveness and marital satisfaction. A total of 168 newlywed couples participated in a four‐wave, 13‐year longitudinal study of marriage. Cross‐sectional and longitudinal path analyses suggested that expressiveness promotes satisfaction by leading spouses to engage in affectionate behavior and by leading them to idealize their partner. Expressive people formed idealized images of their partner because they brought out the best in their partner's behavior and because they interpreted their partner's behavior in a favorable light. The study extends previous research by showing that the benefits of trait expressiveness extend into the second decade of marriage and by providing a plausible explanation of the connections between trait expressiveness and marital satisfaction.
Sex Composition of Children and Marital Disruption in India
Authors: Bose Sunita , South Scott J.
Published: February 2004

Although it has been suggested that parents of sons are less likely than parents of daughters to divorce, few studies have explored this relationship in societies characterized by a strong preference for sons, where such an effect should be most pronounced. Using data from 116,498 once‐married female respondents to the 1992–1993 and 1998–1999 Indian National Family Health Surveys, we found that at lower parities, having at least one son is associated with a significantly lower risk of divorce or separation. Moreover, with few exceptions, the effect of children's sex composition on the risk of divorce holds for subgroups of Indian women across categories of education, religion, location (urban vs. rural), caste, cohort, and region.
Frustrated Fertility: Infertility and Psychological Distress Among Women
Authors: McQuillan Julia , Greil Arthur L. , White Lynn , Jacob Mary Casey
Published: February 2004

Using a random sample of 580 Midwestern women, we test the hypothesis that women who have experienced infertility report higher psychological distress. Approximately one third of our sample reports having experienced infertility sometime in their lives, although the majority of the infertile now have biological children. Drawing hypotheses from identity and stress theories, we examine whether roles or resources condition the effects of infertility or whether its effects are limited to childless women. Infertility combined with involuntary childlessness (including biological and social) is associated with significantly greater distress. For women in this category, the risk of distress is substantial.
Couple Attitudes and Agreement Regarding Pregnancy Wantedness in the Philippines
Authors: Williams Lindy , Sobieszczyk Teresa
Published: February 2004

We compare husbands' and wives' views of the wantedness of their most recent pregnancy in the Philippines, a country where relatively high levels of unintended fertility persist. This research is an extension of earlier work that looked separately at individual men's and women's responses. We analyze survey data for 369 couples and find that those most at risk of experiencing a pregnancy that neither spouse wanted tended to be higher parity couples, those who were more fatalistic, those who were practicing Catholics who attended religious services frequently, and those among whom the husband was the sole breadwinner. Higher parity women and older women were also more apt to experience a pregnancy that was wanted by only 1 spouse. Women who had difficulty discussing sexual matters with their husbands were more likely than other women to have a pregnancy that their husbands wanted but they did not.
Precursors of Nonmarital Fertility in the United States
Authors: Schoen Robert , Tufis Paula
Published: February 2004

The dramatic increase in nonmarital fertility in the United States has generally been explained in terms of either economic circumstances or changing norms and values. We believe that fertility motivations, and the intentions they generate, should be taken into account, and we hypothesize that nonmarital fertility is more likely when children are seen as an important source of social capital. Using data from the first two waves of the National Survey of Families and Households (N= 1,155), we find support for these views. Women who considered the social resource value of children to be high were more likely to have an out‐of‐wedlock birth than were those who did not. Women who did not intend to have a child were less likely to have a nonmarital conception than were women who did intend to have a child. We conclude that understanding recent increases in nonmarital fertility requires an appreciation of the social benefits that children bring to their mothers, married or not.
Individual and Crossover Effects of Work Schedule Fit: A Within‐Couple Analysis
Authors: Gareis Karen C. , Barnett Rosalind Chait , Brennan Robert T.
Published: February 2004

A couple‐level analysis with a sample of 105 female reduced‐hours physicians and their full‐time–employed husbands found individual and spouse crossover effects: Each spouse's ratings of own schedule fit predict own job‐role quality; wives' ratings of partner/family schedule fit predict their marital‐role quality, with a similar trend for husbands; husbands' ratings of own schedule fit predict wives' marital‐role quality; and husbands' ratings of partner/family schedule fit and wives' ratings of own schedule fit predict husbands' psychological distress. These findings highlight the interdependence of couple members' experiences and illustrate potential costs of wives' trading off time at work for time at home.
Ambivalence in the Relationship of Adult Children to Aging Parents and In‐Laws
Authors: Willson Andrea E. , Shuey Kim M. , Elder Glen H.
Published: February 2004

The concept of ambivalence emphasizes the complexity of family relations and the potential for individuals to evaluate relationships as both positive and negative. Using multilevel models, we investigate ambivalence in adult children's relationships with their aging parents and in‐laws (N= 1,599). We focus on factors predicting adult children's ambivalence toward parents and in‐laws within a gendered kinship structure that shapes these relations. We conclude that ambivalence is a useful concept for representing the complexity of parent‐child relationships and is produced within the context of social relations structured by gender and kinship. Results show greater ambivalence among dyads of women, toward in‐laws, among those in poor health, for daughters providing assistance, and for adult children with poor parental relations in early life.
Implications of Childhood Externalizing Problems for Young Adults
Authors: Knoester Chris
Published: February 2004

This study uses data from a national sample of married individuals and their offspring to explore the relationships between childhood externalizing problems and adult psychological well‐being, social support, and intimate relationship quality. The results indicate that childhood problems predict lower levels of adult psychological well‐being, kin support, and relationship quality. The relationship between childhood problems and adult intimate relationship quality, and that between childhood problems and later parent‐child relationship quality, is explained after accounting for the reciprocal influences of childhood problems and the quality of teen parent‐child relations. This finding suggests that the best way for parents to prevent and offset their offspring's difficulties is to maintain quality relationships with them.
Relativistic kinetic theory of electromagnetic waves in equilibrium magnetized plasma. General dispersion equations
Authors: Lazar M , Schlickeiser R
Published: February 2004

The relativistic kinetic theory of parallel propagating electromagnetic waves in a magnetized equilibrium plasma is presented. On the basis of relativistic VlasovMaxwell equations, a general explicit dispersion relation is derived by a correct analytical continuation for all complex frequencies of electromagnetic waves.PACS Nos.: 52.25.Dg, 52.25.Xz, 52.27.Ep, 52.27.Ny, 52.35.Hr, 52.35.Mw, 52.35.Py
State-space approach to generalized thermoelasticity plane waves with two relaxation times under dependence of the modulus of elasticity on reference temperature
Authors: Othman M IA
Published: February 2004

We construct a model of the two-dimensional equations of generalized thermoelasticity with two relaxation times in an isotropic elastic medium with the modulus of elasticity being dependent on the reference temperature. The method of the matrix exponential, which constitutes the basis of the state-space approach of modern theory, is applied to the nondimensional equations. Laplace and Fourier integral transforms are used. The resulting formulation is applied to a problem of a thick plate subject to heating on parts of the upper and lower surfaces of the plate, varying exponentially with time. Numerical results are given and illustrated graphically for the problem considered. A comparison is made with the results predicted by the coupled theory and with the case where the modulus of elasticity is independent of temperature. PACS No.: 46.25.Hf
Finite calculation of divergent self-energy diagrams
Authors: Aste A , Trautmann D
Published: February 2004

Using dispersive techniques, it is possible to avoid ultraviolet divergences in the calculation of Feynman diagrams, making subsequent regularization of divergent diagrams unnecessary. We give a simple introduction to the most important features of such dispersive techniques in the framework of the so-called finite causal perturbation theory. The method is also applied to the "divergent" general massive two-loop sunrise self-energy diagram, where it leads directly to an analytic expression for the imaginary part of the diagram in accordance with the literature, whereas the real part can be obtained by a single integral dispersion relation. It is pointed out that dispersive methods have been known for decades and have been applied to several nontrivial Feynman diagram calculations.PACS Nos.: 11.10.z, 11.15.Bt, 12.20.Ds, 12.38.Bx
One-loop divergences in anomaly-free non-Abelian axial models
Authors: Gagné-Portelance M P , McKeon D.G.C.
Published: February 2004

We consider one-loop divergences in a four-dimensional model in which a non-Abelian vector field has an axial vector coupling with a massless left-handed spinor field. This is done by computing the diagonal element of the second SeeleydeWitt coefficient a2(x,x). Even when the coupling is such that the axial anomaly vanishes, divergences arise that are not gauge invariant. Operator regularization is used throughout so as to leave the matrix γ5 unambiguously defined. PACS No.: 11.15.q
Supersymmetry in five-dimensional spaces of constant curvature
Authors: McKeon D G
Published: February 2004

The simplest possible supersymmetric extensions of the symmetry algebras associated with five-dimensional spaces of constant curvature are considered.PACS No.: 11.15.q
Isotope shifts and hyperfine structure in Sm II
Authors: Masterman D , Rosner S D , Scholl T J , Sharikova A , Holt R A
Published: February 2004

We have measured the isotope shifts of 87 transitions in Sm II in the 418465 nm spectral region and the magnetic-dipole and electric-quadrupole hyperfine constants of 13 low-lying even-parity metastable levels and 76 odd-parity levels. These results will be immediately applicable to stellar spectroscopy.PACS Nos.: 32.30.r, 32.10.f
Energy, fine structure, and transition rate of the doubly excited 3Pe and 3De states for helium
Authors: Wu X -L , Gou B -C , Wang F
Published: February 2004

Energies and fine-structure corrections for the doubly excited 3Pe and 3De states of the helium atom are calculated using the RayleighRitz variational method and the saddle-point variational method with a multiconfiguration-interaction function. The relativistic and mass polarization corrections are included. The oscillator strengths, transition rates, and wavelengths are also calculated. The doubly excited states are grouped into Rydberg series labeled by the quantum numbers K, T, and A to display the systematic regularity along the series. The results are compared with the theoretical and experimental data in the literature. PACS Nos.: 31.15.Pf, 31.25.Jf, 32.70.Cs
Collisional drift waves in stellarator plasmas
Authors: Lewandowski J LV
Published: February 2004

A computational study of resistive drift waves in the edge plasma of a stellarator with an helical magnetic axis is presented. Three coupled field equations, describing the collisional drift-wave dynamics in the linear approximation, are solved as an initial-value problem along the magnetic field line. The magnetohydrodynamic equilibrium is obtained from a three-dimensional local equilibrium model. The use of a local magnetohydrodynamic equilibrium model allows for a computationally efficient systematic study of the impact of the magnetic field structure on drift-wave stability. PACS Nos.: 52.35.Kt, 52.30.Jb, 52.35.Ra
Strange attractors in drift wave turbulence
Authors: Lewandowski J LV
Published: February 2004

A multigrid particle-in-cell algorithm for a shearless slab drift wave model with kinetic electrons is presented. The algorithm, which is based on an exact separation of adiabatic and nonadiabatic electron responses, is used to investigate the presence of strange attractors in drift-wave turbulence. Although the simulation model has a large number of degrees of freedom, it is found that the strange attractor is low dimensional and that it is strongly affected by dissipative (collisional) effects.PACS Nos.: 52.35.Kt, 52.30.Jb, 52.35.Ra
The thermodynamics of a KerrNewmande Sitter black hole
Authors: Dehghani M H , KhajehAzad H
Published: February 2004

We compute the conserved quantities of the four-dimensional KerrNewmande Sitter (KNdS) black hole through the use of the counterterm renormalization method, and obtain a generalized Smarr formula for the mass as a function of the entropy, the angular momentum, and the electric charge. The first law of thermodynamics associated to the cosmological horizon of KNdS is also investigated. Using the minimal number of intrinsic boundary counterterms, we consider the quasilocal thermodynamics of an asymptotic de SitterReissnerNordstrom black hole, and find that the temperature is equal to the product of the surface gravity (divided by 2π) and the Tolman red-shift factor. We also perform a quasilocal stability analysis by computing the determinant of Hessian matrix of the energy with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles and obtain a complete set of phase diagrams. We then turn to the quasilocal thermodynamics of four-dimensional KerrNewmande Sitter black hole for virtually all possible values of the mass, the rotation, and the charge parameters that leave the quasilocal boundary inside the cosmological event horizon, and perform a quasilocal stability analysis of KNdS black hole.PACS Nos.:04.70.Dy, 04.62.+v, 04.60.m
Field-induced effects in an eutectic nematic liquid crystal mixture
Authors: Gathania A K , Raina K K
Published: February 2004

Electric-field effects were investigated in a planar-aligned nematic liquid crystal mixture. Under a DC electric field, we observed the presence of domains. The domain structure changed near the threshold field. The effects of charge injection from the substrate surfaces were investigated. The work function is calculated using Richardson's equation.PACS No.: 61.30.Hn
Dynamic deformations in sand embankments: centrifuge modeling and blind, fully coupled analyses
Authors: Muraleetharan Kanthasamy K , Deshpande Sachin , Adalier Korhan
Published: February 2004

Prediction of deformations during earthquake loading is one of the critical aspects in the design of a geotechnical engineering structure. The dynamic behavior of two centrifuge model sand embankments including deformations is presented and compared with blind predictions made by a fully coupled analysis procedure, the computer code DYSAC2, using a bounding surface elastoplastic model. The centrifuge model embankments were constructed using Nevada sand placed at 62% (dense) and 43% (medium dense) relative densities and consisted of a mild slope on one side and a steep slope on the other side. Both embankments showed substantial movements along the slopes, spikes in the upslope acceleration values, and corresponding dilation spikes in the pore-pressure values. These spikes were more pronounced for the medium-dense sand embankment and on the mild-slope sides for both embankments. The observed behavior is related to the stressstrain behavior of sands undergoing cyclic mobility, and the importance of accurately obtaining the initial static stresses is emphasized. The blind predictions using the computer code DYSAC2 compared reasonably well with the measured results and provided further insight into the behavior of these embankments. The blind predictions similar to those shown in this paper are expected to provide confidence for practicing engineers to use fully coupled procedures for predicting deformations of geotechnical structures subjected to earthquakes.Key words: centrifuge modeling, cyclic mobility, earthquakes, embankment, fully coupled analysis, sand.
Inherent anisotropic stiffness of weathered geomaterial and its influence on ground deformations around deep excavations
Authors: Ng Charles WW , Leung Erin HY , Lau C K
Published: February 2004

The shear modulus G0 at very small strain (0.001% or less) is an important parameter for predicting ground movements of many geotechnical structures. Recent advances in laboratory testing enable the measurement of shear moduli in different planes of a soil specimen for the evaluation of stiffness anisotropy. Most studies of stiffness anisotropy have been conducted on sedimentary soils and clean sands, and the anisotropic stiffness of weathered material has not yet been fully investigated. In this study, the degree of inherent stiffness anisotropy of completely decomposed tuff (CDT) was evaluated through multidirectional shear wave velocity measurements using bender elements. Tests were performed on both natural (undisturbed) Mazier and block samples and the results were compared. CDT clearly exhibits inherent stiffness anisotropy, with a stiffness ratio between the shear modulus in the horizontal and vertical planes (Ghh/Ghv) ranging from 1.26 to 1.36. The stiffness parameters derived from the laboratory tests were utilized in numerical analysis of the influence of the inherent stiffness anisotropy on ground deformations around a hypothetical but typical multipropped deep excavation. For the given soil models and parameters used, the maximum computed wall deflection and ground settlement due to the pumping of groundwater prior to any excavation were 8% and 19% greater, respectively, than those of an isotropic analysis. The maximum wall deflection and ground settlement because of the combined effects of the pumping and recharging of groundwater inside the site and the subsequent multistage excavations were 15% and 10%, respectively, less in the anisotropic analysis.Key words: inherent anisotropic stiffness, shear modulus, excavation, ground movement, volcanic soil, weathered material.
Load transfer of fibre-reinforced polymer (FRP) composite tapered piles in dense sand
Authors: Sakr Mohammed , Naggar M Hesham El , Nehdi Moncef
Published: February 2004

This paper describes an experimental study conducted using a large, laboratory-scale testing facility to test pile segments at different stress levels. The objectives of the study were twofold: to examine the load-transfer mechanism of tapered piles in compression, and to evaluate the effect of pile material on pile performance characteristics. The results of axial compressive loading tests on 26 pile load tests were presented using fibre-reinforced polymer (FRP) concrete composite tapered piles and steel piles. Two installation techniques were used, including conventional head driving and toe driving using a new technique. Piles were tested at different confining pressures to represent a pile segment at depths of 4.0 and 8.0 m. The load distribution along the pile shafts was measured and the results were compared with those from an analytical solution in terms of the taper coefficient Kt. The comparison showed reasonable agreement between Ktvalues established from the experiments and those obtained from the analytical solution. The measured toe resistance of tapered and cylindrical piles was compared with those from the analytical solution. A simple rational approach was proposed for the design of tapered piles.Key words: tapered piles, FRP, pile capacity, axial performance, centrifuge modeling, shaft resistance, toe resistance.
Viscous behaviour of St-Roch-de-l'Achigan clay, Quebec
Authors: Marques Maria Esther Soares , Leroueil Serge , Soares de Almeida Márcio de Souza
Published: February 2004

This paper describes the viscous behaviour of St-Roch-de-l'Achigan clay, a Champlain Sea clay from Quebec, Canada. The general geotechnical profile of the soil deposit was first established with static cone penetration tests, vane tests, and some laboratory tests performed at different depths. For the study of the viscous behaviour of the clay, a special laboratory test program was established for specimens taken at depths from 4.8 to 5.8 m. This program included special incremental loading oedometer tests, constant rate of strain (CRS) oedometer tests performed at different strain rates, isotropic and anisotropic triaxial compression tests, and undrained shear tests. All these tests were performed under a constant temperature, varying from 10 to 50 °C. The test results show that the vertical yield stresses and the entire limit state curve depend on strain rate and temperature. The critical state line is also temperature dependent in the void ratio (e)  log principal effective stress (p′) diagram but not in the deviator stress (q)  principal effective stress (p′) diagram. The results also show that microstructuring may develop when the temperature is high or the strain rate small.Key words: viscosity, strain rate, temperature, laboratory tests.
Grout field trials in outwash sands
Authors: Brachman R WI , Martin C D , Gilliss S A
Published: February 2004

Field trials were conducted to evaluate three different permeation grouts in a medium-dense, silty sand outwash deposit. Sodium silicate, microfine powder, and microfine cement based grouts were used. Visual observations from boreholes, a large-diameter shaft, and two inspection drifts through the grouted sand are reported. The sodium silicate grout produced a uniformly grouted material with massive structure. The microfine powder grout did not harden in the ground. The injection of the microfine cement grout resulted in only discrete veins of grouted soil. Laboratory testing of the grouted soil recovered from block samples quantified the strength increase of the sand grouted with sodium silicate. Cross-hole seismic velocity tests conducted through the grout zone prior to construction of the inspection shaft and drifts indicated increased velocities in the grouted soils. The successful trials established the suitability of the sodium silicate grout as a means of ground treatment for temporary support for tunnel excavation.Key words: permeation grouting, soil improvement, sodium silicate, microfine cement.
Laboratory studies of clogging of landfill leachate collection and drainage systems
Authors: Fleming I R , Rowe R K
Published: February 2004

The findings of a series of studies investigating the clogging of leachate collection and drainage systems for municipal landfill sites are described. Batch tests, column studies, and field-scale "mesocosm" test cells were used to study the development of a thick microbial biofilm covering the surfaces and filling the pore space of the granular drainage media. Within this biofilm, anaerobic microbial consortia effect the stabilization of the organic load (expressed as chemical oxygen demand), with the concurrent precipitation within the granular drainage system of various minerals dominated by calcite.Key words: municipal waste, leachate, clogging, drainage, biofilm, calcite.
Assessment of the modified slump test as a measure of the yield stress of high-density thickened tailings
Authors: Gawu S KY , Fourie A B
Published: February 2004

Yield stress values of four thickened (high-density) mineral tailings at varying solids concentrations were determined using three different techniques. The first set of values was measured using the modified slump test approach with an open-ended cylinder having an aspect ratio of 1.2. A second set was derived from measurements obtained from a coaxial cylinder fitted to a Rheolab® MC1 rheometer. The results were graphically compared with those obtained using the miniature vane technique, a popular and well-accepted method of measuring yield stress. Empirical relations developed from the modified slump test appear to predict reasonably accurate yield stress values up to about 200 Pa when compared with the vane and rheometer results. It is concluded that, although the time-dependent nature of the tailings tested may induce errors as much as ±30% for some samples, the modified slump test provides a reliable and simple test for evaluating the yield stress of thickened tailings. The method can therefore be employed as a first approximation of the changing parameters of high-density thickened tailings in the field without necessarily resorting to sophisticated equipment.Key words: high-density thickened tailings, rheology, shear yield stress, slump, torque.