bluuebunny/crossref_metadata_2025 huggingface dataset:
The Economic Costs of Marital Dissolution: Why Do Women Bear a Disproportionate Cost?
Authors: Holden Karen C. , Smock Pamela J.
Published: July 2003

We review the literature on the economic consequences of marital dissolution for women. Longitudinal studies of the effects of divorce and widowhood indicate that both types of dissolutions have negative and prolonged consequences for women's economic well-being. This is not the case for men, where marital dissolution often leads to an improved economic standard of living. Following an examination of empirical studies and measurement issues in the divorce and widowhood literatures, we describe preexisting and direct sources of women's postdissolution economic insecurity. Women's postdissolution economic hardship is due to multiple interrelated factors, often only superficially coupled with the marital dissolution event. In particular, the division of labor during marriage, lower wages paid to women both during and after marriage, and the lack of adequate postdissolution transfers to women imply that unless changes in women's work roles are mirrored by social policy initiatives and men's assumption of equal responsibility for children (both within and out of marriage), economic prospects for previously married women will remain poor.
The Social Impact of War
Authors: Modell John , Haggerty Timothy
Published: July 2003

The authors, by reviewing the recent work of several behavioral and social science disciplines concerned with the impact of war upon society, suggest that the study of war’s social ramifications has been characterized by the publication of empirical work that neglects, to some extent, the larger sociological implications of war as well as its ability to reorder society. The work published over the last two decades and reviewed here was written in the United States in the wake of the Vietnam conflict. This work has examined the implications of military manpower recruitment and training, as well as the psychological and economic implications of wartime service. The immediacy of this conflict, however, may have deterred sociological analysts from systematically examining the macroscopic implications of social change, a void that is remedied, in part, by historical and literary analyses that consider the long-range impacts of past wars on their belligerent societies. Finally, the authors propose that the study of the life course may offer one avenue of inquiry that can connect the micro- and macro- levels of analysis, thus connecting the soldier’s story to that of his changing society.
Social Stress: Theory and Research
Authors: Aneshensel Carol S.
Published: July 2003

This chapter differentiates the stressful consequences of social organization from the stressful antecedents of psychological disorder. The pivotal distinction concerns whether the occurrence of stressors is viewed as socially determined, or as independent of social placement. Recent research is evaluated concerning both the social distribution of stress and social variation in response to stress. Two particularly productive areas of inquiry are also reviewed: self-efficacy as a mediator between social position and stress; and the intersection of macro- and micro-stress processes in economic and occupational spheres, with emphasis upon gender stratification. This review concludes that the occurrence of systemic stressors is not necessarily an indication of a social system run amok but may reflect instead the system functioning precisely as it is supposed to function.
Crime and Deviance in the Life Course
Authors: Sampson Robert J. , Laub John H.
Published: July 2003

Criminological research has emphasized the strong relationship between age and crime, with involvement in most crimes peaking in adolescence and then declining. However, there is also evidence of the early onset of delinquency and of the stability of criminal and deviant behavior over the life course. In this essay we reconcile these findings by synthesizing and integrating longitudinal research on childhood antisocial behavior, adolescent delinquency, and adult crime with theory and research on the life course. Consistent with a life-course perspective, we focus on continuities and discontinuities in deviant behavior over time and on the social influences of age-graded transitions and salient life events. Furthermore, we critically assess the implications of stability and change for longitudinal research. We conclude with an emerging research agenda for studying the relationship of crime and deviance with a broad range of social phenomena (e .g. occupational attainment, opportunity structures, marital attachment) over the life course.
Social Science Research and Contemporary Studies of Homelessness
Authors: Shlay Anne B. , Rossi Peter H.
Published: July 2003

This review takes stock of contemporary social science research on homelessness. Research on homelessness in the 1980s has been prompted by the increased numbers and visibility of homeless persons including men, women, and families, as well as young people without families. Most empirical research employs a working definition of homelessness as the condition of those people who are without a permanent place to live. However, a wide range in perspectives differ over what homelessness is. In part, this reflects recognition of some the dynamics of homelessness that include intermittent movement in and out of homeless situations. But it also reflects changes in social values over what constitutes adequate housing. Research shows that the population of homeless persons is diverse, although most homeless persons are young and single. Many have severe chronic problems including mental illness, alcoholism, physical disabilities, and poor health. A significant number have criminal histories. Many were raised in foster care situations. All suffer from economic deprivation, and many have experienced long-term unemployment. Considerable disagreement exists over the number of homeless persons, in part because the scarcity of resources to address this problem politicizes the debate. There is also strong disagreement over the root causes of homelessness.

Debate over the causes of homelessness is caught up in whether the focus of research should be on structural forces that permit homelessness to occur or the immediate reasons why people become homeless. Research now suggests that the extreme situation of homelessness may be more accurately portrayed as the result of the convergence of many factors that drive this phenomenon, including housing market dynamics, housing and welfare policy, economic restructuring and the labor market, and personal disabilities. Policies designed to ameliorate homelessness have been inadequate to stem the tidal forces that produce such severe destitution, and this trend is likely to continue. Future important directions include addressing the role of employment and social ties in producing homelessness, comparing the economic and social situation of homeless and non-homeless persons, evaluating programs designed to aid homeless persons, and developing international comparisons of homelessness.
Models for Sample Selection Bias
Authors: Winship Christopher , Mare Robert D.
Published: July 2003

When observations in social research are selected so that they are not independent of the outcome variables in a study, sample selection leads to biased inferences about social processes. Nonrandom selection is both a source of bias in empirical research and a fundamental aspect of many social processes. This chapter reviews models that attempt to take account of sample selection and their applications in research on labor markets, schooling, legal processes, social mobility, and social networks. Variants of these models apply to outcome variables that are censored or truncated—whether explicitly or incidentally—and include the tobit model, the standard selection model, models for treatment effects in quasi-experimental designs, and endogenous switching models. Heckman’s two-stage estimator is the most widely used approach to selection bias, but its results may be sensitive to violations of its assumptions about the way that selection occurs. Recent econometric research has developed a wide variety of promising approaches to selection bias that rely on considerably weaker assumptions. These include a number of semiand nonparametric approaches to estimating selection models, the use of panel data, and the analyses of bounds of estimates. The large number of available methods and the difficulty of modelling selection indicate that researchers should be explicit about the assumptions behind their methods and should present results that derive from a variety of methods.
Media Images and the Social Construction of Reality
Authors: Gamson William A. , Croteau David , Hoynes William , Sasson Theodore
Published: July 2003

Ideally, a media system suitable for a democracy ought to provide its readers with some coherent sense of the broader social forces that affect the conditions of their everyday lives. It is difficult to find anyone who would claim that media discourse in the United States even remotely approaches this ideal. The overwhelming conclusion is that the media generally operate in ways that promote apathy, cynicism, and quiescence, rather than active citizenship and participation. Furthermore, all the trends seem to be in the wrong direction—toward more and more messages, from fewer and bigger producers, saying less and less. That’s the bad news.

The good news is that the messages provide a many-voiced, open text that can and often is read oppositionally, at least in part. Television imagery is a site of struggle where the powers that be are often forced to compete and defend what they would prefer to have taken for granted. The underdetermined nature of media discourse allows plenty of room for challengers such as social movements to offer competing constructions of reality and to find support for them from readers whose daily lives may lead them to construct meaning in ways that go beyond media imagery
The State and Fiscal Sociology
Authors: Campbell John L.
Published: July 2003

Despite recent developments in “fiscal sociology” (i.e. the sociological analysis of taxation and public finances), few efforts have been made to synthesize scholarly developments in the field. This is particularly surprising because much of the literature on the determinants of taxation bears directly on the debates in political sociology about the social, political, institutional, and other determinants of government policy. This essay reviews and integrates the literature on tax policy formation and relates it to these general debates. It also explores some of the important but often neglected effects that taxation has on such phenomena as political revolution, state building, economic organization, labor force participation, and philanthropy. Thus, this essay demonstrates the significance and reviews recent developments in fiscal sociology.
Comparative Patterns of Retirement: Recent Trends in Developed Societies
Authors: Guillemard Anne-Marie , Rein Martin
Published: July 2003

This essay reviews the changes in the age structure of modern labor markets that have led to a dramatic decline in the employment of older workers. We document this trend and explore future trends, examine different explanations of the role of the welfare state, the labor market, and the life course. Each of these perspectives offers different views into the social meaning of early retirement.
The Sociology of Ethnic Conflicts: Comparative International Perspectives
Authors: Williams Robin M.
Published: July 2003

Oppositions and deadly conflicts among ethnic collectivities are important around the word. Ethnies (our term for ethnic groups) also strongly affect interstate relations. Both interethnic and ethnic-state conflicts tend to be severe, protracted, and intractable. At the extremes, the stakes are total: survival versus genocide

Competition and rivalry for individualized economic and political goods are important, but the most intense conflicts are to be expected when the stakes are collective goods, including categorical claims to prestige and political authority.

States are major actors in creating, accentuating, or diminishing ethnic identities. States are both arenas of rivalry and conflict and resources for ethnic mobilization and counter-mobilization.

Because both ethnies and states are diverse, careful specification is required for fruitful analysis. The same dictum applies for the diverse types of oppositions and of conflicts.

Ethnic conflicts arise from complex combinations of ethnic strength, class, inequality, political opportunity, mobilization resources, interdependence, and international interventions. Frequent but nonviolent protests, for example, are most likely by organized collectivities with substantial resources, operating in relatively open political systems. International aid to parties in domestic conflicts appears to prolong and intensify ethnic struggles.

Research in this field contends with many difficulties, and one-sided theories do not fare well. Yet abundant descriptive materials are available, statistical techniques are improving, conceptual clarification continues, and substantive knowledge does accumulate. Accordingly, there is hope for better understanding of some of the most destructive and tragic conflicts of our times.
Consequences of Marital Dissolution for Children
Authors: Seltzer Judith A.
Published: July 2003

This paper examines changes in marriage as an institution for rearing children in the United States. It reviews the effects of marital instability and living arrangements on children's welfare, and focuses on how children's economic, emotional, and social needs are met when parents separate. The review shows that changes in marriage and childrearing have different consequences for women and men. For women, marriage and parenthood are distinct institutions. Women provide for children's needs, whether or not the women are married to their children's fathers. For men, marriage defines responsibilities to children. At divorce, men typically disengage from their biological children. When men remarry they may acquire new children whom they help to support. The review describes the effects on children of divorced mothers' and fathers' varying commitments to childrearing. It considers the difficulties that divorced parents experience when they try to continue to share responsibilities for children after separation, and it suggests avenues for future research.
Stepfamilies in the United States: A Reconsideration
Authors: Cherlin Andrew J. , Furstenberg Frank F.
Published: July 2003

This paper discusses five themes related to the formation and functioning of stepfamilies. The first section examines how demographic trends, particularly changing marriage and remarriage rates and rising levels of cohabitation, are affecting post-marital family arrangements. The second section looks at the creation of new forms of kinship associated with remarriage and cohabitation. The third and fourth parts of the paper explore issues related to the social organization of stepfamilies and the consequences for children. The final section of the paper takes up the question of whether and why remarried persons are at higher risk of divorce. We discuss some implications of research for public policy and current theoretical debates about the status of the American family.
Aging and Generational Relations: A Historical and Life Course Perspective
Authors: Hareven Tamara K.
Published: July 2003

This review explores historical changes in generational relations in American society as they affect adaptation to the later years of life. Following a life course perspective, the review examines changes in the timing of life transitions, in family relations, and in generational and kin assistance and their impact on support in old age. In doing so, it demonstrates the significance of a historical and life course approach to the understanding of generational relations over time. Dispelling prevailing myths about coresidence and generational assistance in the past, the review discusses the circumstances under which nuclear household arrangements were modified and explores patterns of assistance inside and outside the household. It links demographic changes in the timing of life course transitions with patterns of supports to aging parents in the context of changing reciprocities among kin. By comparing two cohorts of adult children in an American community in terms of their supports to aging parents, as well as their attitudes toward generational assistance, the review identifies historical changes in the relations between generations in the larger context of family relations and kin assistance.
A Circuitous path to Macrostructural Theory
Authors: Blau Peter M.
Published: July 2003

I introduce this memoir about my academic career by describing the fortuitous incidents involved in my coming to this country and becoming a sociologist. In graduate school my sociological orientation changed under the influence of Merton and Lazarsfeld from grand theories to systematic theory grounded in research. My dissertation was a field study of bureaucracy in terms of Weber’s theory, which led to a book on exchange theory. Next I collaborated with Duncan on a nationwide study of occupational achievement and mobility, for which I learned regression analysis, reluctantly at first, but later becoming converted to it. During the next decade I conducted a research program on bureaucracy, specifically of quantitative studies of various types of formal organizations, from which I developed a limited organizational theory. The limitations of this theory prompted me to construct a formal macrostructural theory of population structure’s influences on intergroup relations, which was subsequently tested in empirical research on the 125 largest metropolitan areas in the United States.
Institutional Arrangements and Stratification Processes in Industrial Societies
Authors: Kerckhoff Alan C.
Published: July 2003

This chapter reviews the current state of our knowledge about the role of institutional arrangements in stratification processes in industrial societies. The particular institutional arrangements considered are those of educational and labor force organizations. The review is organized around the Blau-Duncan basic model of status attainment and points to the need for a more elaborated conceptualization. Institutional arrangements structure the connections between social origin and educational attainment, between educational attainment and early labor force placements, and between early and later placements in the labor force. Industrial societies vary widely in the nature of these institutional arrangements, and that variation affects the patterns of movement from origins to destinations in the stratification system. Features of educational institutions considered include separation of students into specialized schools and ability groups (tracking), degree of central control, degree of autonomy, degree of stratification, and the number and specialized nature of credentials. Features of labor force institutions considered include occupational and firm specific job classifications, internal labor markets and vacancy chains, industrial sectors and career lines. Critical aspects of the societal variation are the form of the interface between education and labor force structures and the nature of the transition from school to work. A preliminary set of hypotheses linking institutional arrangements and stratification processes is derived from this review.
On the Benefits of Populations for Noisy Optimization
Authors: Arnold Dirk V. , Beyer Hans-Georg
Published: July 2003

It is known that, in the absence of noise, no improvement in local performance can be gained from retaining candidate solutions other than the best one. Yet, it has been shown experimentally that, in the presence of noise, operating with a non-singular population of candidate solutions can have a marked and positive effect on the local performance of evolution strategies. So as to determine the reasons for the improved performance, we have studied the evolutionary dynamics of the (μ, λ)-ES in the presence of noise. Considering a simple, idealized environment, we have developed a moment-based approach that uses recent results involving concomitants of selected order statistics. This approach yields an intuitive explanation for the performance advantage of multi-parent strategies in the presence of noise. It is then shown that the idealized dynamic process considered does bear relevance to optimization problems in high-dimensional search spaces.
Poisons in the System: The Global Regulation of Hazardous Pesticides
Authors: Hough Peter
Published: July 2003

A number of international regimes have emerged in the last thirty years contributing to the global regulation of pesticides. These developments bear testimony to the work of pressure groups and epistemic communities in highlighting the environmentally polluting effects of hazardous pesticides, to which the regimes have contributed. However these regimes were only achievable because they also satisfied other values, given greater priority at the global level. Human health and global trade values were also at stake, rather than just the conservation of the non-human environment.

This global picture is in contrast to the situation at the domestic level, where environmental values are prominent in the regulation of pesticides. It is more difficult for environmental values to be prioritized at the global level but the development of a global civil society has put environmental values on the international agenda and has led to them becoming more influential in the future development of international regimes. This article explores these arguments.
Singularity-Free Fully-Isotropic Translational Parallel Mechanisms
Authors: Carricato Marco , Parenti-Castelli Vincenzo
Published: June 2003

Parallel mechanisms show desirable characteristics such as a large payload to robot weight ratio, considerable stiffness, low inertia and high dynamic performances. In particular, parallel manipulators with fewer than six degrees of freedom have recently attracted researchers' attention, as their employ may prove valuable in those applications in which a higher mobility is uncalled-for.

The attention of this paper is focused on translational parallel mechanisms (TPMs), that is on parallel mechanisms whose output link (platform) is provided with a pure translational motion with respect to the frame.

It deals with the general problem of the topological synthesis and classification of TPMs and it investigates both their constraint and direct singularities. In particular, it identifies for the first time special families of fully-isotropic mechanisms. Such manipulators exhibit outstanding properties, as they are free from singularities and show a constant orthogonal Jacobian matrix throughout their workspace. As a consequence, both the direct and the inverse position problems are linear and the kinematic analysis proves straightforward.
Regular salbutamol use increases CXCL8 responses in asthma: relationship to the eosinophil response
Authors: Gordon J.R. , Swystun V.A. , Li F. , Zhang X. , Davis B.E. , Hull P. , Cockcroft D.W.
Published: June 2003

Regular salbutamol use can exacerbate allergen-induced airway eosinophilia in asthmatics, but its effect on airway eosinophil chemokine responses is unknown.

Asthmatic subjects (n=14) were treated for 10 days with placebo or salbutamol in a double-blind, cross-over study, then given same-dose allergen challenges. Their sputa were then analysed 1 and 7 h later for a panel of eosinophil-related cytokines. Eosinophils from five test and three control subjects were tested for expression of CXCL8/interleukin (IL)‐8, and its receptors and responsiveness to CCL11/eotaxin and CXCL8/IL‐8.

Sputum CXCL8/IL‐8, but not IL‐5, CCL5/regulated on activation, T‐cell expressed and secreted, CCL7/monocyte chemotactic protein‐3, CCL11/eotaxin, granulocyte-macrophage colony-stimulating factor or tumour necrosis factor levels, were increased (42%) by the salbutamol treatments. The CXCL8/IL‐8 levels correlated with the proportions of sputum eosinophils and these cells, but not other sputum cells, stained strongly for CXCL8/IL‐8. The circulating eosinophils of the tested subjects (n=5) expressed CXCL8/IL‐8 receptors and secreted high levels of this chemokine. Neutralisation of sputum CXCL8/IL‐8 reduced eosinophil chemotactic responses to these samples by 19±5%.

These data suggest that regular use of salbutamol can augment airway CXCL8/interleukin‐8 responses to allergen challenge and that this CXCL8/interleukin‐8 could contribute to the airway inflammatory response.
N‐acetylcysteine reduces chemokine releaseviainhibition of p38 MAPK in human airway smooth muscle cells
Authors: Wuyts W.A. , Vanaudenaerde B.M. , Dupont L.J. , Demedts M.G. , Verleden G.M.
Published: June 2003

Reactive oxygen species are involved in the activation of several mitogen-activated protein kinases (MAPKs), key-players in the production of several cytokines. Therefore the current study investigated whetherN‐acetylcysteine (NAC), an antioxidative agent, inhibits the interleukin (IL)‐1β‐induced expression and production of eotaxin and monocyte chemotactic protein (MCP)‐1 in human airway smooth muscle cells (HASMC).

NAC (10 mM) decreased the expression of eotaxin and MCP‐1, by 46±11% (n=7) and 87±4% (n=6), respectively; the eotaxin release was inhibited by 75±5% (n=7), whereas the MCP‐1 release was decreased by 69±4% (n=10). NAC (1 mM) also decreased the IL‐1β‐induced activation of p38 MAPK.

Compared with unstimulated cells, a four-fold increase in 8‐isoprostane production in IL‐1β‐stimulated HASMC was observed, which could be inhibited by NAC in a concentration-dependent way, with a maximum inhibition of 39±12% with 1 mM NAC.

The present study demonstrated thatN‐acetylcysteine inhibits the interleukin‐1β‐induced eotaxin and monocyte chemotactic protein 1 expression and production due to a decreased activation of p38 mitogen-activated protein kinase. This study has also shown thatN‐acetylcysteine decreases the interleukin‐1β‐induced production of reactive oxygen species, as suggested by a reduction in the 8‐isoprostane production.
BR22, a 26 kDa thyroid transcription factor‐1 associated protein (TAP26), is expressed in human lung cells
Authors: Yang M-C.W. , Wang B. , Weissler J.C. , Margraf L.R. , Yang Y-S.
Published: June 2003

The current authors have previously identified BR22, a thyroid transcription factor (TTF)‐1 associated protein 26 (TAP26), which interacts with TTF‐1 to enhance human surfactant protein (SP)‐B promoter activity in transfected 293 cells. However, the expression of TAP26 in the lung cells and its biological relevance to the SP‐B production under physiological conditions were not examined.

In this study, endogenous co-immunoprecipitation andin situimmunohistochemical staining techniques were employed to explore the presence of TAP26 and TTF‐1 complex in the lung epithelial cells. The correlation of TAP26, TTF‐1 and SP‐B expression was inspected in H441 cells in the presence of dexamethasone, a known positive effector of the SP‐B promoter.

Monoclonal antibody (mAb) against TAP26 can co-immunoprecipitate both TAP26 and TTF‐1 from H441 cells. Using this antibody inin situstaining of human lung sections, the data show that TAP26 is present in the lung alveolar epithelial cells. Reverse transcriptase-polymerase chain reaction and Western blot analyses of type-II cells as well as dexamethasone-treated H441 cells suggest that TAP26 expression is modulated coordinately with SP‐B and TTF‐1 in these cells.

In summary, the current study demonstrates that thyroid transcription factor‐1 associated protein 26 is an associated protein of thyroid transcription factor‐1 in the lung alveolar epithelial cells where surfactant protein gene expressions take placein vivo.
Subcutaneous injection of metallic mercury
Authors: Soo Y OY , Wong C H , Griffith J F , Chan T YK
Published: June 2003

Deliberate self-injection of metallic mercury into subcutaneous tissue is uncommon. A 41-year-old lady with a history of schizophrenia was admitted to our hospital after deliberate injection of metallic mercury into her right wrist and antecubital fossa. Physical examination was unremarkable except for the injection marks over right antecubital fossa and wrist. The presence of subcutaneous mercury deposits in her right elbow and wrist was confirmed by X-rays and ultrasound scan. Three days later, erythema, swelling, induration and tenderness were seen over the injection sites. At the operation on day 9, mercury streaks were seen within the brachialis muscle belly, surrounded by friable necrotic tissues along the tract. A similar picture was noted in her right wrist. The necrotic tissues and mercury streaks were removed. The patient had been unco-operative and she only received incomplete treatment with dimercaprol and 2,3-dimercaptosuccinic acid. Her total blood mercury level (normal B < 50 nmol/L) decreased from 101-151 nmol/L in the first two weeks to 42 nmol/L 3 months later. Her 24-hour urinary mercury excretion (normal B < 10 nmol) changed from 55.7-209.5 nmol in the first 7 weeks to 125.4 nmol 3 months later. This case illustrates that soft tissue metallic mercury can produce local necrosis and may allow continuous absorption with persistent elevations in blood and urinary mercury levels. Therefore, early surgical removal of subcutaneous mercury deposits is required to prevent local complications and minimize the risk of systemic absorption and toxicity.
Radiation-induced versus endogenous DNA damage: commentary on Pollycove and Feinendegen
Authors: Tanooka Hiroshi
Published: June 2003

Quantitative comparison of ROS-induced endogenous DNA damage with DNA damage induced by ionizing radiation at environmental level, presented by Pollycove and Feinedegen, is timely and provides basic data for establishing a a sound rule for radiation protection. Main point added to their estimation is quantitative data on oxidative damage to DNA precursormolecules, such as oxo dGTP and their cellular decomposition efficiency. If the precursor damages are taken into account, the amount of initial endogenous DNA damage would be increased by a factor of 100 / 10 000
Radiation-induced versus endogenous DNA damage: commentary on Pollycove and Feinendegen
Authors: Thomassen David G , Metting Noelle F
Published: June 2003

The premises underlying the article by Pollycove and Feinendegen are unlikely to generate disagreement among most scientists. The authors do a good job of reviewing the scientific literature on the importnat topic of radiation-induced versus endogenous DNA damage, and they use the available data to calculate numerical estimates and comparisons of DNA damages induced by radiation versus metabolic processes. However, these numbers should in no way be confused with proof or disproof of the involvement of specific biological mechanisms. Many important questions for low-dose radiobiology remain unanswered, and there is no substitute for experimental demonstration.
Aspects of Disc Brake Judder
Authors: Jacobsson H
Published: June 2003

Brake judder is a braking induced, forced vibration occurring in different types of vehicles. The judder frequency is directly proportional to the revolution speed of the wheel and therefore also to the velocity of the vehicle. The driver experiences judder as vibrations in the steering wheel, brake pedal and floor. In the higher frequency range, the structural vibrations are accompanied by a sound. Brake judder primarily affects the comfort but could, when confronting an inexperienced driver for the first time, lead to faulty reactions and reduced driving safety. Furthermore, a specific type of judder, so-called hot judder, is related to disc cracking. There are numerous publications available dealing with high frequency vibrations, such as brake squeal, including mathematical models for analysis and simulation. However, low frequency phenomena, such as brake judder and groan, have received much less attention. There is a growing interest from the automotive industry concerning brake judder. Even though few companies would admit that they have the problem, it is not unusual to meet people who have experienced the problem in their own passenger cars. Much of the knowledge concerning brake judder remains within the companies. Hence, very few people have the full picture. The purpose of the present paper is to give an overview of the brake judder problem.
Parameter Estimation of a Single Wheel Station using Hybrid Differential Evolution
Authors: Pedchote C , Purdy D J
Published: June 2003

This paper investigates an application of a ‘discrete variable’ hybrid differential evolution (dvHDE) method to parameter estimation of a single wheel station. The parameters of the single wheel station represent a quarter of the suspension of a medium sized family car. The estimation method developed incorporated the dvHDE and use of a Kalman filter (KF). The KF provides estimates of the ‘unmeasured’ states of the system being studied. The dvHDE, which works as a function optimizer, provides a ‘best fit’ set of model parameters. The performance of the dvHDE method was examined and compared against the standard gradient-based (GB) method, downhill simplex (DS) method and original differential evolution (DE) method on simulated and experimentally obtained data. The normalized mean squared errors (MSEs) of the system outputs are considered as the fitting criterion in the optimization process. The identified model parameters gave an MSE of below 3.5 per cent. The dvHDE method performed better over the GB, DS and DE methods and has been shown to improve the convergence rate by approximately 19 per cent over the original DE method, without sacrificing ability to find the global minimum point.
A Method for Evaluating the Thermal Performance of Passenger Seats
Authors: Ratts E B , McElroy J W , Reed W G
Published: June 2003

In this paper, an experimental method to quantify the capability of an automotive seat to move heat and moisture away from the heat and water source is presented. To test the method, a test apparatus was constructed that generates heat and water vapour. The apparatus was placed on a seat cushion for a fixed time period. At the end of the period, heat and water transported were measured. These integrated values were used to quantify the seat's capability to move heat and moisture and ultimately to compare seats. By the impulse test method, the passenger seat had an effusivity of 94.7 W s1/2/m2 K. A non-ventilated seat transferred 5 W of thermal energy and an average of 0.36 g/min of water in 1800 s. A ventilated seat transferred 13.9 W of thermal energy and 0.70 g/min of water in 1800 s.
A case‐study of an orographic cyclone south of the Alps during the MAP SOP
Authors: Buzzi A. , D'Isidoro M. , Davolio S.
Published: June 2003

The cyclonic formation of IOP15 of the Mesoscale Alpine Programme (MAP) (6–7 November 1999) is examined with respect to mesoscale features in the geopotential, temperature, wind and precipitation fields. The effect of orography at different scales is evaluated using a mesoscale meteorological model (BOLAM). Model errors are determined by comparing standard and special MAP SOP observations with model output. An Optimal Interpolation reanalysis of the initial condition, aimed at assimilating mesoscale structures, is applied, resulting in an overall reduction of the forecast error, including position of local scale precipitation maximum in the Lago Maggiore target area south of the Alps. Different orography representations have an impact on the error patterns, since it is shown that the Alpine orography largely controls the cyclone growth over the Mediterranean. Particular attention is devoted to the model verification of precipitation and wind fields in the vicinity of the Alps, where special observations allow for fine‐scale analysis. Copyright © 2003 Royal Meteorological Society
The mechanics of eddy transport from one hemisphere to the other
Authors: Paldor Nathan , Sigalov Andrey , Nof Doron
Published: June 2003

The trajectory of a dense eddy propagating along the bottom of a meridional channel of parabolic cross‐section from the southern to the northern hemisphere is described by a Hamiltonian system with two degrees of freedom. Two simplified types of motion exist in which the meridional acceleration vanishes: in midlatitudes the motion is geostrophic, poleward (equatorward) directed along the western (eastern) flank of the channel, while on the equator the motion consists of zonal oscillations along the potential‐well generated by the bottom parabolic cross‐section of the channel. The eddy's propagation along the equator is much faster than that in midlatitudes, which enhances its dissipation via mixing with the overlying ocean water. For motions that occur slightly off the equator the eastward segment is stable while the westward segment is unstable, so an expulsion from the equatorial regime takes place during the latter. A dense eddy that arrives near the equator along the west flank of the channel, has to cross the channel to its east flank where it can either oscillate back (westward) to the other side, or move poleward from the equator along the channel's east flank. The eddy's dissipation during the equatorial part of its trajectory is very large, and the probability of the dissipated eddy leaving the equator to either hemisphere is identical.

The non‐integrability of the system is manifested in the sensitive combination of the equatorial and the midlatitude regimes that renders the dynamics of the transport of dense eddies across the equator chaotic. This description explains both the sharp decrease in the amount of Antarctic bottom water mass in the immediate vicinity of the equator in the western Atlantic Ocean and the ‘splitter’ effect of the equator. This effect, encountered in earlier fluid dynamical numerical simulations, causes a current, and a cloud of particles, to chaotically split into two parts flowing in different hemispheres. Copyright © 2003 Royal Meteorological Society
Factors determining the decrease in surface wind speed following the evening transition
Authors: Lapworth A.
Published: June 2003

Meteorological measurements were made by surface instrumentation at a flat rural site over a period of several years. These are analysed to determine any systematic factors governing the decrease in surface wind speed during the evening. The 10 m wind speed is found to depend on the surface cooling and gradient wind speed, with a larger decrease in the 10 m wind speed with surface cooling when the gradient wind is stronger. The relationships are relatively unaffected by cooling rate. Momentum and heat fluxes are also found to have well defined relationships with surface cooling and gradient wind, with downward heat fluxes reaching a maximum at a 2 degC cooling. These observations are compared with the predictions of a simple semi‐analytical model which gives qualitatively similar results to the observations and shows that the greater 10 m wind speed decrease at higher gradient wind speeds is due to a thicker boundary layer. The model also predicts the formation of an upper inversion with an increase in 10 m wind later in the evening and this prediction is compared with balloon and surface observations made on a clear evening. A simple forecasting rule for the reduction in 10 m wind during the evening is given. Copyright © Crown copyright, 2003. Royal Meteorological Society
Solid‐state modification of isotactic polypropylene (iPP) via grafting of styrene. I. Polymerization experiments
Authors: Picchioni F. , Goossens J. G. P. , van Duin M. , Magusin P.
Published: July 2003

Grafting of vinyl monomers onto isotactic polypropylene (iPP) in the solid state, that is, below the melting point, displays several advantages over melt or solution grafting processes, such as negligible degradation of the iPP and absence of any solvent. The final properties of such iPP modifications or actually compatibilized PP blends are dependent on the dispersion of the new polymer into the iPP matrix, which is controlled to a large extent by the degree of grafting versus the amount of free homopolymer formed. In the present work, the solid‐state modification of iPP by styrene has been investigated from the point of view of the monomer polymerization behavior. In order to determine the styrene conversion and the distribution of the newly formed PS phase along the radius of the iPP powder particles, the reaction products were characterized by infrared (FTIR) and Raman spectroscopy. Fractionation of the reaction products via selective solvent extraction allowed the determination of the grafting efficiency (Φ). It was shown that besides the grafted PS two additional types of PS are formed, that is, free PS homopolymer in the pores of the PP powder and free PS in the amorphous PP phase. Phi shows an optimum as a function of the feed peroxide composition and the feeding rate. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3279–3291, 2003
Crystallization and melting behaviors of maleated polyethylene and its composite with fibrous cellulose
Authors: Zhang Farao , Qiu Wulin , Yang Liqun , Endo Takashi , Hirotsu Takahiro
Published: July 2003

The crystallization and melting behaviors of maleated polyethylene (MPE) and its composite with fibrous crystalline cellulose are investigated by differential scanning calorimetry. MPE exhibits a higher crystallization starting temperature, because of the interactions between maleic anhydride (MA) groups for nucleation, and lower melting and crystallization enthalpies, because of the intensive irregularity of MPE chains compared to unmaleated PE (UPE). Fibrous cellulose (FC) slightly facilitates the nucleation of MPE but causes no change in the transition enthalpies of MPE for crystallization and melting in UPE–FC and MPE–FC composites. The kinetics of crystallization show that the Avrami exponent depends on the content of MA groups and FC to a small extent and the activation energy is largely determined by the MA content, suggesting the irregularity and decreased mobility of MPE chains that is due to the interactions between the grafted MA groups in MPE and the FC composite. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3292–3300, 2003
Synthesis and properties of oil absorption resins filled with polybutadiene
Authors: Shan Guo‐Rong , Xu Ping‐Ying , Weng Zhi‐Xue , Huang Zhi‐Ming
Published: July 2003

Polybutadiene (PB) is used to fill an oil absorption resin as a physical crosslinker to construct a kind of 3‐dimensional network with a high degree crosslinking and low crosslink density. A series of acrylic resin particles with various compositions are prepared by suspension polymerization, using benzoyl peroxide (BPO) as an initiator and ethylene glycol dimethacrylate (EGDMA) as a chemical crosslinker. The effects of the polymerization temperature, initiator concentration, monomer feed ratio, and chemical and physical crosslinker concentrations on the oil absorbency and gel fraction (degree of crosslinking) are studied. The recipe and operation conditions are optimized as follows: a mass ratio of 3:1 for styrene (St)/dodecyl methacrylate or St/butyl acrylate, 0.5 wt % BPO, and 80°C for 7–8 h. The effect of the physical crosslinker (PB) concentration is complex. The oil absorbency increases with increasing PB at lower EGDMA concentrations. However, under this same condition, particles cannot be formed if the PB concentration is higher than a certain value. By contrast, there is an optimum PB concentration when the EGDMA concentration is higher. The oil absorption speed is also investigated. The presence of PB can speed up absorption. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3309–3314, 2003
Nanocomposites of poly(trimethylene terephthalate) with organoclay
Authors: Ou Cheng‐Fang
Published: July 2003

Two different kinds of clay were organomodified with cetylpyridinium chloride (CPC) as an intercalation agent. Poly(trimethylene terephthalate) (PTT)/organoclay nanocomposites were prepared by the solution intercalation method. Wide‐angle X‐ray diffraction (WAXD) indicated that the layers of clay were intercalated by CPC and the interlayer spacing was a function of the cationic exchange capacity (CEC) of the clay: the higher the CEC, the larger the interlayer spacing is. The WAXD studies showed that the interlayer spacing of organoclay in the nanocomposites depends on the amount of organoclay. From the results of differential scanning calorimetry analysis it was found that clay behaves as a nucleating agent and enhances the crystallization rate of PTT. The maximum enhancement of the crystallization rate for the nanocomposites was observed in nanocomposites containing about 5 wt % organoclay with a range of 1–15 wt %. The thermal stability of the nanocomposites was enhanced by the addition of 1–10 wt % organoclay as found from thermogravimetric analysis. The thermal stability of the PTT/organoclay nanocomposites was related to the organoclay content and the dispersion in the PTT matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3315–3322, 2003
Filler fraction effect on creep response of crosslinked polyester matrix with mineral filler
Authors: Hristova J. , Minster J.
Published: July 2003

The effect of a particle marble filler on the creep response of a crosslinked polyester matrix before and after physical aging is described. Composites with various filler–polyester matrix percentages are prepared by applying mixing technology, curing at room temperature, and postcuring above the glass‐transition temperature. Two groups of specimens of identical composition are studied. The first group is tested 1 month after preparation (relatively nonaged), whereas the second group is tested after 13 years of storage at stable room temperature and humidity, at current atmospheric pressure, and in the absence of direct light (aged). The two groups of specimens (aged and nonaged) are subjected to creep measurements. The modulus of elasticity and the creep compliance are determined, plotted against the filler volume fraction, and fit by empirical equations. A simple mechanical model is proposed to fit the compliance curves, and good agreement between the measured and predicted values is shown. The mechanical behavior of the composites is also described, using empirical equations that fit the relation between the composite/matrix ratio of the deformation characteristics and the filler volume fraction. A crucial matrix influence is proposed to fit the compliance curves, and good agreement between the measured and predicted values is shown. Experimentally established natural regularities can be used to predict the creep compliances of composites from a less demanding experimental program. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3329–3335, 2003
Atom transfer radical polymerization of n‐butyl methacrylate in an aqueous dispersed system
Authors: Peng Hui , Cheng Shiyuan , Feng Linxian , Fan Zhiqiang
Published: July 2003

Atom transfer radical polymerization of n‐butyl methacrylate (BMA) was conducted in an aqueous dispersed system with different kinds of copper complexes. The partitioning behavior of the copper complexes, including CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipydine (dNbpy), CuCl2/dNbpy, CuCl/2,2′‐bipydine (bpy), CuCl2/bpy, CuCl/bis(N,N′‐dimethylaminoethyl)ether (bde), and CuCl2/bde between the monomer (BMA), and water was studied in detail with ultraviolet‐visible spectroscopy. The results show that with a less hydrophobic ligand, such as bpy or bde, most of the Cu(I) or the Cu(II) complexes migrated from the BMA phase to the aqueous phase, the atom transfer equilibrium was destroyed, and the polymerization was nearly not controlled; it converted to classical emulsion polymerization. As to the very hydrophobic ligand dNbpy, although the partitioning study of the copper complexes indicated that not all the copper species were restricted to the organic phase, the linear correlation between the molecular weight and the monomer conversion and the narrow polydispersities confirmed that the polymerization was still quite well controlled. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3175–3179, 2003