bluuebunny/crossref_metadata_2025 huggingface dataset:
The Application of Latent Curve Analysis to Testing Developmental Theories in Intervention Research
Authors: Curran Patrick J. , Muthén Bengt O.
Published: March 2003

The effectiveness of a prevention or intervention program has traditionally been assessed using time‐specific comparisons of mean levels between the treatment and the control groups. However, many times the behavior targeted by the intervention is naturally developing over time, and the goal of the treatment is to alter this natural or normative developmental trajectory. Examining time‐specific mean levels can be both limiting and potentially misleading when the behavior of interest is developing systematically over time. It is argued here that there are both theoretical and statistical advantages associated with recasting intervention treatment effects in terms of normative and altered developmental trajectories. The recently developed technique of latent curve (LC) analysis is reviewed and extended to a true experimental design setting in which subjects are randomly assigned to a treatment intervention or a control condition. LC models are applied to both artificially generated and real intervention data sets to evaluate the efficacy of an intervention program. Not only do the LC models provide a more comprehensive understanding of the treatment and control group developmental processes compared to more traditional fixed‐effects models, but LC models have greater statistical power to detect a given treatment effect. Finally, the LC models are modified to allow for the computation of specific power estimates under a variety of conditions and assumptions that can provide much needed information for the planning and design of more powerful but cost‐efficient intervention programs for the future.
Proximal Impact of Two First‐Grade Preventive Interventions on the Early Risk Behaviors for Later Substance Abuse, Depression, and Antisocial Behavior
Authors: Ialongo Nicholas S. , Werthamer Lisa , Kellam Sheppard G. , Brown C. Hendricks , Wang Songbai , Lin Yuhua
Published: March 2003

We assessed the immediate effects of two universal, first‐grade preventive interventions on the proximal targets of poor achievement, concentration problems, aggression, and shy behaviors, known early risk behaviors for later substance use/abuse, affective disorder, and conduct disorder. The classroom‐centered (CC) intervention was designed to reduce these early risk behaviors by enhancing teachers' behavior management and instructional skills, whereas the family‐school partnership (FSP) intervention was aimed at improving parent‐teacher communication and parental teaching and child behavior management strategies. Over the course of first and second grades, the CC intervention yielded the greatest degree of impact on its proximal targets, whereas the FSP's impact was somewhat less. The effects were influenced by gender and by preintervention levels of risk. Analyses of implementation measures demonstrated that greater fidelity to the intervention protocols was associated with greater impact on behavior ratings and on achievement scores, thus providing some evidence of specificity in the effect of the interventions.
Innovative Community Services for Rape Victims: An Application of Multiple Case Study Methodology
Authors: Campbell Rebecca , Ahrens Courtney E.
Published: March 2003

A qualitative multiple case study design was used to examine communities across the United States that have developed coordinated community‐based programs to assist rape victims. Previous studies have suggested that coordinated community programs help victims obtain needed resources and services. This study provided a follow‐up examination of how and why these programs are helpful to rape victims. In‐depth interviews were conducted with rape victim advocates, rape crisis center directors, police officers, prosecutors, doctors, nurses, and rape survivors from 22 communities with coordinated programs. A comparison sample of 22 communities with fewer coordinated programs was also obtained. Results indicated that the high coordination communities had three types of programs to address sexual assault: coordinated service programs, interagency training programs, and community‐level reform groups. Although not all of these programs directly address service delivery for rape victims, they help create a community culture that is more responsive to victims' needs. The research team and participants developed an explanatory model of why these program are effective in addressing rape victims' needs. This model hypothesizes that coordinated programs reflect an understanding of the multiple contexts of service delivery and embody that knowledge in services that are consistent with victims' needs. Narrative data from the interviews with service providers and rape survivors are used to develop and support this model.
Principles for Designing Randomized Preventive Trials in Mental Health: An Emerging Developmental Epidemiology Paradigm
Authors: Brown C. Hendricks , Liao Jason
Published: March 2003

An emerging population‐based paradigm is now being used to guide the design of preventive trials used to test developmental models. We discuss elements of the designs of several ongoing randomized preventive trials involving reduction of risk for children of divorce, for children who exhibit behavioral or learning problems, and for children whose parents are being treated for depression. To test developmental models using this paradigm, we introduce three classes of design issues: design for prerandomization, design for intervention, and design for postintervention. For each of these areas, we present quantitative results from power calculations. Both scientific and cost implications of these power calculations are discussed in terms of variation among subjects on preintervention measures, unit of intervention, assignment, balancing, number of pretest and posttest measures, and the examination of moderation effects.
Using Qualitative Methods to Develop Contextually Relevant Measures and Preventive Interventions: An Illustration
Authors: Dumka Larry E. , Gonzales Nancy A. , Wood Jennifer L. , Formoso Diana
Published: March 2003

Qualitative methods were used to develop a contextually relevant quantitative measure of parenting stress and inform the design of family‐focused interventions aimed at preventing adolescent mental and behavioral health problems. The study focused on the experiences of low‐income one‐ and two‐parent families representing three ethnic groups (Mexican, African, and European Americans) living in low‐income neighborhoods in a large Southwestern city. This report describes the place of this study in a broader program of prevention research, the qualitative methods and data analysis procedures employed, and how the results were used to develop a new measure of parenting stress and inform future program design. The report also includes reflective comments on the methods used and lessons gained.
Characteristics of Calls to Israeli Hotlines During the Gulf War
Authors: Gilat Izhak , Lobel Thalma E. , Gil Tsvie
Published: March 2003

The current study presents results of a survey of 3,215 calls received at seven centers of telephone emergency services (TES) in Israel during the Gulf War, when citizens of Israel experienced severe stress resulting from SCUD missile attacks. Whereas former surveys have shown that characteristics of calls to TES in Israel are generally not affected by external stressogenic events, a remarkable change was recorded in both the quantity and quality of calls received in TES centers in Israel during the Gulf War. The relative frequencies of problem categories presented by callers during the Gulf War revealed a significant increase in “environmental pressures,” a category that reflected the stressful situation of the war, as opposed to intra‐ or interpersonal problems typical of peacetime calls. A comparison between this group of “war calls” and a control group of “nonwar calls,” revealed that the two groups represented populations of callers differing in sociodemographic characteristics, expectations, and benefits from the calls. Results are discussed in reference to the unique role of TES as a source of psychological first‐aid in a community crisis situation.
Constructing a Tree for Community Leaders: Contexts and Processes in Collaborative Inquiry
Authors: Tandon S. Darius , Azelton L. Sean , Kelly James G. , Strickland Debra A.
Published: March 2003

This paper presents collaborative research between a university‐based team and a grass roots community organization on the south side of Chicago. The purpose of the work is to document the nature of community leadership as expressed by members of the host organization. Using a semistructured interview, 77 community members nominated by the host organization were asked about various aspects of their community work. Qualitative analyses of interview text generated a set of 56 codes concerning different aspects of community leadership as reported by grassroots leaders. These codes were subsequently grouped together into five conceptually linked dimensions of community leadership. A“ leadership tree” that simultaneously analyzes and visually displays each of these five dimensions of community leadership was created. Implications of the methodology used to create the leadership tree are discussed for the salience of qualitative methods in community research.
The Community Response to Rape: Victims' Experiences with the Legal, Medical, and Mental Health Systems
Authors: Campbell Rebecca
Published: March 2003

This research examined how the legal, medical, and mental health systems respond to the needs of rape victims. A national random sample of rape victim advocates (N = 168) participated in a phone interview that assessed the resources available to victims in their communities. as well as the specific experiences of the most recent rape victim with which they had completed work. Results from hierarchical and iterative cluster analysis revealed three patterns in victims' experiences with the legal, medical, and mental health systems. One group of victims had relatively positive experiences with all three systems, a second group had beneficial outcomes with only the medical systems, and the final group had difficult encounters with all three systems. Multinominal logistic regression was then used to evaluate an ecological model predicting cluster membership. Community‐level factors as well as features of the assault and characteristics of the victims predicted unique variance in victims' outcomes with the legal, medical, and mental health systems. These findings provide empirical support for a basic tenet of ecological theory: environmental structures and practices influence individual outcomes. Implications for ecological theory and interventions to improve the community response to rape victims' needs are discussed.
Culturally Sensitive AIDS Educational Videos for African American Audiences: Effects of Source, Message, Receiver, and Context
Authors: Herek Gregory M. , Gillis J. Roy , Glunt Eric K. , Lewis Jeffrey , Welton David , Capitanio John P.
Published: March 2003

The importance of using culturally sensitive educational materials in HIV‐related interventions with racial and ethnic minority groups is widely recognized. However, little empirical research has been conducted to assess the relative effectiveness of different techniques for creating culturally sensitive AIDS educational videos. Two field experiments with three samples of African American adults (N = 174, 173, and 143) were conducted to assess how source characteristics (race of communicator), message characteristics (multicultural message vs. culturally specific message), and audience characteristics (racial distrust and AIDS‐related distrust) influence proximate (perceptions of the message's credibility and attractiveness) and distal (AIDS‐related attitudes, beliefs, and behavioral intentions) output variables for AIDS educational videos. In Study 1, an AIDS video with a culturally specific message was rated as more credible, more attractive, and of higher quality than was a video with a multicultural message. The multicultural message was rated less favorably when delivered by a White announcer than when the announcer was Black. In Study 2, the same pattern was replicated with a second community sample and a campus‐based sample. Study 2 also indicated that a multicultural message might be more effective if delivered in a culturally specific context, namely, after audience members watch a culturally specific video. Minimal changes were observed in distal outcome variables. It is argued that influencing proximate output variables is necessary, though not sufficient, for effecting long‐term change in AIDS‐related attitudes, beliefs, and behaviors.
Evaluation of Indicated Preventive Intervention (Secondary Prevention) Mental Health Programs for Children and Adolescents
Authors: Durlak Joseph A. , Wells Anne M.
Published: March 2003

Evaluated the outcomes of 130 indicated preventive interventions (secondary prevention) mental health programs for children and adolescents that seek to identify early signs of maladjustment and to intervene before full‐blown disorders develop. Results indicate such programs significantly reduce problems and significantly increase competencies. In particular, behavioral and cognitive‐behavior programs for children with subclinical disorders (mean ESs in the 0.50s) appear as effective as psychotherapy for children with established problems and more effective than attempts to prevent adolescent smoking, alcohol use, and delinquency. In practical terms, the average participant receiving behavioral or cognitive‐behavior intervention surpasses the performance of approximately 70% of those in a control group. Of particular interest was the high mean effect (0.72) achieved by programs targeting incipient externalizing problems which are customarily the least amenable to change via traditional psychotherapeutic efforts when they reach clinical levels. Priorities for future research include greater specification of intervention procedures, assessment of treatment implementation, more follow‐up studies, and identifying how different participants respond to early intervention.
Partners and Fellow Patients: Two Sources of Emotional Support for Women with Breast Cancer
Authors: Pistrang Nancy , Barker Chris
Published: March 2003

This study examined the helping process that occurred when 26 breast cancer patients (the disclosers) talked about their illness‐related concerns with their partner and, in a separate conversation, with a fellow patient (the volunteer helpers). The conversations were rated by trained observers and by the disclosers in terms of several process and outcome variables. From the observers' perspective, the volunteer helpers were more helpful, empathic, and supportive, less critical, and used more self‐disclosure than the partners. Disclosers did not differentiate between the two types of helper, and gave generally high ratings to both conversations. Strengths and weaknesses of each type of helper were identified. Findings are discussed in relation to the literature on formal and informal helping, and implications for training nonprofessional helpers are suggested.
Tobacco, Drug, and HIV Preventive Media Interventions
Authors: Jason Leonard A.
Published: March 2003

Media‐based health promotion interventions can reach large segments of the population and lower barriers to participation in programs. By collaborating with media specialists, we can develop interventions that might be broader, more publicized, and ultimately more likely to change behaviors and attitudes within the community. The present paper describes a series of media interventions involving smoking cessation, drug abuse prevention, stress reduction, weight control, and HIV/AIDS prevention. The process by which I became involved in these interventions is discussed, and the implications of developing these types of large‐scale behavioral interventions are discussed.
Applying Cluster Analysis to Test a Typology of Homelessness by Pattern of Shelter Utilization: Results from the Analysis of Administrative Data
Authors: Kuhn Randall , Culhane Dennis P.
Published: March 2003

This study tests a typology of homelessness using administrative data on public shelter use in New York City (1988–1995) and Philadelphia (1991–1995). Cluster analysis is used to produce three groups (transitionally, episodically, and chronically homeless) by number of shelter days and number of shelter episodes. Results show that the transitionally homeless, who constitute approximately 80% of shelter users in both cities, are younger, less likely to have mental health, substance abuse, or medical problems, and to overrepresent Whites relative to the other clusters. The episodically homeless, who constitute 10% of shelter users, are also comparatively young, but are more likely to be non‐White, and to have mental health, substance abuse, and medical problems. The chronically homeless, who account for 10% of shelter users, tend to be older, non‐White, and to have higher levels of mental health, substance abuse, and medical problems. Differences in health status between the episodically and chronically homeless are smaller, and in some cases the chronically homeless have lower rates (substance abuse in New York; serious mental illness in Philadelphia). Despite their relatively small number, the chronically homeless consume half of the total shelter days. Results suggest that program planning would benefit from application of this typology, possibly targeting the transitionally homeless with preventive and resettlement assistance, the episodically homeless with transitional housing and residential treatment, and the chronically homeless with supported housing and long‐term care programs.
Life Circumstances and Personal Resources as Predictors of the Ten‐Year Course of Depression
Authors: Cronkite Ruth C. , Moos Rudolf H. , Twohey Joan , Cohen Caryn , Swindle Ralph
Published: March 2003

A 10‐year naturalistic study of 313 patients who entered treatment for unipolar depression and a community comparison group of 284 nondepressed adults was conducted. We compared life stressors, social resources, personal resources, and coping among patients who were remitted (N = 76), partially remitted (N = 146), or nonremitted (N = 91). Compared with the controls and the remitted patients, the partially remitted and nonremitted patients consistently experienced more life stressors and fewer social resources, were less easygoing, and relied more on avoidance coping. A less easygoing disposition, fewer close relationships, and more reliance on avoidance coping were associated with higher odds of experiencing a course of partial remission or nonremission. In addition, more depressive symptoms and medical conditions predicted nonremission.
Description and Immediate Impacts of a Preventive Intervention for Conduct Problems
Authors: Reid John B. , Eddy J. Mark , Fetrow Rebecca Ann , Stoolmiller Mike
Published: March 2003

A population‐based randomized intervention trial for the prevention of conduct problems (i.e., oppositional defiant disorder and conduct disorder) is described. The LIFT (Linking the Interests of Families and Teachers) intervention was designed for all first‐ and fifth‐grade elementary school boys and girls and their families living in at‐risk neighborhoods characterized by high rates of juvenile delinquency. The 10‐week intervention strategy was carefully targeted at proximal and malleable antecedents in three social domains that were identified by a developmental model of conduct problems. From 12 elementary schools, 671 first and fifth graders and their families participated either in the theory‐based universal preventive intervention or in a control condition. The intervention consisted of parent training, a classroom‐based social skills program, a playground behavioral program, and systematic communication between teachers and parents. A multiple measure assessment strategy was used to evaluate participant satisfaction and participation, fidelity of implementation, and the immediate impacts of the program on targeted antecedents.
Antecedents and Consequences of Victimization of Lesbian, Gay, and Bisexual Young People: A Structural Model Comparing Rural University and Urban Samples
Authors: Waldo Craig R. , Hesson-McInnis Matthew S. , D'Augelli Anthony R.
Published: March 2003

Research indicates that antigay victimization is widespread and that lesbian, gay, and bisexual young people may be very vulnerable to such victimization. The current study builds upon previous work by Hershberger and D'Augelli (1995), who studied the consequences of sexual orientation‐based victimization in 194 urban lesbian, gay, and bisexual youths. Using structural equation modeling, the present study models both antecedents and consequences (including psychological distress, self‐esteem, and suicidality) of victimization via a secondary analysis of their data set. In addition, a second sample of 54 lesbian, gay, and bisexual youths from a rural university setting was examined to cross‐validate and generalize the relationships found in urban settings. Results indicated that a revised model of victimization exhibited sufficient fit to the urban sample data and provided preliminary support for the generalizability of the model beyond the initial sample. Additional similarities were found between the urban and rural university community samples, including a high prevalence of reported suicide attempts: 42% of the urban sample and 32% of the rural university sample had attempted suicide at least once. Results indicated that victimization based on sexual orientation has similar correlates for young people in different community settings.
A Developmental Approach to Prevention Research: Configural Antecedents of Early Parenthood
Authors: Gest Scott D. , Mahoney Joseph L. , Cairns Robert B.
Published: March 2003

A developmental framework emphasizing the combined impact of correlated constraints within and without the individual was applied to a prospective longitudinal study of early parenthood. The purpose was to use a person‐approach to the analysis of longitudinal data to clarify risk for early parenthood and to generate hypotheses about potentially useful intervention strategies. Respondents were 475 youth who were assessed annually from seventh grade through the end of high school and, again, at ages 20 and 24. The risk patterns associated with parenthood were the same for both sexes. Individuals with a middle‐school configuration of low socioeconomic status, high aggression, low academic skills, low popularity, and prior grade failure were most likely to become parents by early adulthood. Risk for early parenthood increased substantially for respondents who dropped out of school early, regardless of their initial risk status.
Empirical Support for the Critical Assumptions of Empowerment Theory
Authors: Foster-Fishman Pennie G. , Salem Deborah A. , Chibnall Susan , Legler Ray , Yapchai Courtney
Published: March 2003

This exploratory case study provides empirical support for three critical assumptions of empowerment theory. Many empowerment theorists have argued that empowerment takes on multiple forms across people, is contextually embedded, and shifts over time (Rappaport, 1984; Zimmerman, 1990, 1995). To better understand the implications of these assumptions for empowerment theory and the research and intervention methods we employ, the empowerment experiences of 49 employees within a large human service delivery organization were explored. A method well suited to investigate empowerment's assumptions of multiplicity and dynamism—a constructivist approach to inquiry—was employed. Content analyses of interview and observational data revealed that the process of empowerment may be more complex than originally conceived. Not only did multiple meanings and desires for empowerment emerge across employees and between employees and leaders, but several shifting ecologies impacted the employees' lives, causing the employees' empowerment experiences to fluctuate. Empowerment emerged as a dynamic, highly individualistic, contextually layered process. Multiple forms, contexts, and dynamics that influenced employee empowerment are described. Implications of these findings for empowerment research and intervention are discussed.
Personal Resources and the Social Distribution of Depression
Authors: Turner R. Jay , Lloyd Donald A. , Roszell Patricia
Published: March 2003

This paper addresses the hypothesis that gender, age, marital status, and SES matter for depression partly because of associated differences in the availability and/or impact of the personal resources of mastery and self‐esteem. It is argued that findings indicating that the social distributions of these resources complement those for depression would provide preliminary support for this hypothesis. Based on a large urban community sample (n = 1,390), our findings fail to support the availability hypothesis in relation to marital status, provide only modest support in reference to age and gender, but yield compelling support in relation to socioeconomic status (SES). Indeed, variations in the availability of these resources, especially mastery, provide a largely, if not entirely, adequate explanation for the SES–depressive symptoms relationship and accounts for nearly half of the SES–Major Depressive Disorder relationship. Although the significance of mastery was more pronounced among women and unmarried persons, such differences did not contribute to understanding observed gender or marital status variations in depression.
A Qualitative Evaluation of School‐Based Family Resource and Youth Service Centers
Authors: Kalafat John , Illback Robert J.
Published: March 2003

As part of the Kentucky Education Reform Act, school‐based Family Resource/Youth Service Centers were commissioned to address those poverty‐related issues that attenuate children and youths' coming to school prepared to learn. The centers had flexible mandates and were to adapt their service profiles to local urban, suburban and rural communities. A variety of grounded, inductive qualitative strategies were employed in an implementation evaluation that yielded profiles or domains of program elements, and descriptions of implementation strategies and impact on participants. These program descriptors were considered accurate by program personnel, formed the basis for training new program coordinators, and have served as reliable predictors of educational outcomes for program participants, thus affirming the utility of the qualitative evaluation approaches.
Opening the Black Box: Using Process Evaluation Measures to Assess Implementation and Theory Building
Authors: Harachi Tracy W. , Abbott Robert D. , Catalano Richard F. , Haggerty Kevin P. , Fleming Charles B.
Published: March 2003

The past decade has seen increasing recognition in prevention science of the need to move away from a black box approach to intervention evaluation and toward an approach that can elaborate on the mechanisms through which changes in the outcomes operate (Chen & Rossi, 1989; Durlak & Wells, 1997; Spoth et al., 1995). An approach that examines issues of program implementation is particularly critical in the design of efficacy studies of school‐based preventive interventions. Numerous preventive intervention strategies are now delivered within the schools, often by regular classroom teachers. The extent to which teachers faithfully deliver a particular curriculum or incorporate instructional strategies emphasized by an intervention is a critical question for the overall project evaluation. This article illustrates the utilization of process measures from a multicomponent school‐based prevention program to examine implementation of a teaching staff development intervention, and the program's underlying theoretical basis. Given the nested study design, the analyses utilize hierarchical linear models (Bryk & Raudenbush, 1992) to examine changes in teaching strategies by condition and investigate the hypothesized relationships between teaching practices and student behaviors based on the program's theoretical framework. Results suggest that teaching practices in two of the six intervention focus areas were positively impacted in the first 18 months of the project. Findings also support th relationships between teachers' instructional practices and students' behaviour.
Preparing the Way: A Qualitative Study of High‐Achieving African American Males and the Role of the Family
Authors: Maton Kenneth I. , Hrabowski Freeman A. , Greif Geoffrey L.
Published: March 2003

Employed qualitative methods to examine the role of the family in the academic success of very high‐achieving African American males. Findings revealed a complex tapestry of family processes and contexts involved in each youth's journey to outstanding academic achievement. Specifically, the combined importance of parental‐determined academic engagement, strict discipline, nurturance, and community connectedness appeared to counteract potentially negative contextual influences of neighborhood, peers, schools, and society. The qualitative findings tell a multifaceted, rich, and compelling story of the pathways to academic success for Black males, and highlight the need for culture‐specific and ecologically based conceptualization, research, and intervention approaches.
Assessment of the Effectiveness of Genetic Counseling by Telephone Compared to a Clinic Visit
Authors: Sangha Karan K. , Dircks Anita , Langlois Sylvie
Published: April 2003

Maternal serum screening, also known as the triple screen, is used during pregnancy to assess the risk of carrying a fetus with specific chromosome abnormalities or open spina bifida. All women in British Columbia who screen positive are eligible for genetic counseling and are offered amniocentesis. The purpose of this study is to determine what differences (if any) exist in patients' understanding and/or anxiety when genetic counseling for a positive triple screen is conducted in person versus over the telephone. Each patient who participated was given the choice of having genetic counseling in person or over the telephone, this after a randomized design failed to elicit any participants. Using a written postcounseling questionnaire, each patient was assessed for her understanding of the information presented in the session, and her anxiety regarding her risk. In this small pilot study, no large differences were detected in patients' understanding or anxiety when genetic counseling was conducted by telephone versus in person.
Development of an Interactive Decision Aid for Female BRCA1/BRCA2 Carriers
Authors: Kaufman Elizabeth M. , Peshkin Beth N. , Lawrence William F. , Shelby Rebecca , Isaacs Claudine , Brown Karen , Rispoli Jessica , O'Neill Suzanne , Hurley Karen , DeMarco Tiffani , Brogan Barbara , Grumet Sherry , Jandorf Lina , McKenna Kristine , Valdimarsdottir Heiddis , Schwartz Marc D.
Published: April 2003

Shared decision making between patients and providers is becoming increasingly common, particularly when there is no clear preferred course of action. As a result, decision aids are being adopted with growing frequency and have been applied to many medical decision‐making issues. One such issue where there is uncertainty is breast cancer risk management among BRCA1/BRCA2 carriers. We present the development of a CD‐ROM decision aid to facilitate risk management decision making in this population. Our decision aid was developed with the intention of providing it through a randomized clinical trial. The CD‐ROM is a multimedia, interactive intervention which provides information about breast cancer, risks associated with BRCA1 and BRCA2 mutations, risk management options for hereditary breast cancer, and a breast cancer risk management decision aid. The goal of this CD‐ROM, offered as an adjunctive intervention, is to reduce decisional conflict and psychological distress and improve comprehension of risk information, decisional satisfaction, medical adherence, and quality of life for this population of women at increased risk for breast cancer.
Diesel engine failures due to combustion disturbances, caused by fuel with insufficient lubricity
Authors: von Wielligh A.J. , Burger N.D.L. , Wilcocks T.L.
Published: March 2003

A large number of diesel engine failures have been reported in the immediate past. The large proportion of these engines that were investigated, were recently overhauled engines that failed soon after the overhaul process. In some cases, these engines failed on the dynamometer, while it was tested before delivery to the customer. The most common failure on a large number of these engines, were pistons seizing in the crown region causing seizure of the piston in the cylinder. Tests were done to correlate the lubricity of the fuel that was used and the failure of the engines. Limits were obtained from which it could be determined when the fuel was not of a proper quality and where engine failures took place. It is finally recommended that the specification SABS 342 be amended to include the requirements for the lubricity of diesel fuels.
Comparative study of wear mechanism of surface treated AISI 316L stainless steel
Authors: Dogan Halit , Findik Fehim , Oztarhan Ahmet
Published: March 2003

Coating is a technique employed for the surface of materials to have thermal insulation, hot corrosion and oxidation resistance. Ion implantation forms modifications in surface composition or morphology of solids which yield to a change of physical and especially mechanical properties such as hardness and modulus of elasticity. The objective of this investigation is to concentrate on the friction and wear behaviour of TiN, N2 and Zr implanted and TiN and Tinalox PVD coated 316L stainless steel and compare with a substrate. Mainly stainless steels were of attraction, because they frequently demonstrate a poor tribological behaviour, which can be enhanced when they are hardened by incorporating N2, TiN Tinalox and Zr and forming a hardened surface zone.
Magneto‐hydrodynamic squeeze film characteristics for finite rectangular plates
Authors: Lin Jaw‐Ren
Published: March 2003

The squeeze‐film characteristics between two parallel rectangular plates with an electrically conducting fluid in the presence of a transverse magnetic field are analyzed. The squeeze‐film Reynolds equation applicable to the curved surfaces is derived using the continuity equation and the magneto‐hydrodynamic (MHD) motion equations. A closed‐form solution is obtained for the squeeze‐film pressure of parallel rectangular plates, and applied to predict the squeeze‐film behavior. According to the results, the presence of magnetic fields signifies an enhancement in the squeeze‐film pressure. On the whole, the magnetic‐field effect characterized by the Hartmann number provides an increase in value of the load‐carrying capacity and the response time as compared to the classical non‐conducting lubricant case, especially for larger values of the aspect ratio or smaller values of film height.
Influence of cleaning pretreatments on tribological properties of zinc phosphated steels
Authors: Hivart Philippe , Bricout Jean‐Paul
Published: March 2003

Among lubrication processes for cold forging of steel, phosphating is the most common. Depending on contact between piece and phosphating solution, the success of this treatment depends on steel surface preparation. Despite this obvious fact, the influence of cleaning pretreatments such as degreasing and acid pickling are seldom considered from a mechanical point of view and specially from a tribological one. Through a tribological test, the preparation of the surface of steel billets to be zinc phosphated and soaped was studied. Having shown the importance of degreasing, this study tries to connect the parameters of warm acid pickling, such as bath composition and dipping time to the tribological performances of the coated part.
2D23D: Management and design perspectives on retail branding
Authors: Kent Tony
Published: March 2003

The aim of this research is to define the development and boundaries of the retailer brand primarily through the elements of identity and image. Two perspectives are introduced to explain the ways in which three‐dimensional branding and sensory experiences of the retail brand can arise. One approach is marketing led; the other is based on design studies. The study assesses the development of retail branding, the areas in which sensory experience of the retail brand occurs and its implications for retailers. It concludes with new insights into retail branding and proposals for the subject to be studied across disciplinary boundaries.
Visual merchandising and the creation of discernible retail brands
Authors: Kerfoot Shona , Davies Barry , Ward Philippa
Published: March 2003

This research presents the results of an initial investigation on “visual merchandising” and its effects on purchase behaviour and brand recognition. The context is concessionary branded female fashion offerings within a department store. The research utilises semi‐structured interviews with a small sample of female undergraduate students. The interviews incorporated the use of stimulus material – photographs taken of concessions in a department store some 150 miles away from the research location. The results suggest that the themes that linked most strongly to purchase intention were: merchandise colours, presentation style, awareness of fixtures, path finding, sensory qualities of materials and lighting. Initial findings suggest that liking of display does not totally determine purchase, but does make it four times more likely.
Car collisions, physics, and the State Highway Patrol
Authors: Larabee David
Published: April 2003

This paper describes activities which include a demonstration and a presentation by a State Highway Patrol crash reconstructionist. These activities are designed to deepen the traditional momentum-energy unit, offering an application both dramatic and familiar to high school students.
Hearing light
Authors: Euler Manfred , Niemann Kurt , Müller Andreas
Published: April 2003

The sensitivity of the human ear is brought to a close by an amazingly simple experiment. The design of a photoacoustic converter with kitchen equipment, which helps to gain qualitative insights on ear performance as well as on photoacoustic detection methods, is described.
Improving precision and accuracy in the g lab
Authors: Moreland Parker
Published: April 2003

With MBL technology and careful attention to detail, the accuracy and precision obtained in the introductory g lab using the picket fence and simple pendulum can be 0.1 percent or better using the techniques described.
Angle of the crescent Moon
Authors: Higbie Jack
Published: April 2003

In Australia the moon is tilted the wrong way. This note explains why.
Simple equations for linear partially elastic collisions
Authors: Loveland Kurt T.
Published: April 2003

The center of mass reference frame is utilized to develop simple equations for the kinematics and energetics of linear partially elastic collisions which permit easy solution of problems and analysis of laboratory data when the collisions are nonideal.
Laser diffraction experiments with pseudoliquids and pseudosolids
Authors: Isenberg Cyril
Published: April 2003

This paper describes how to demonstrate the optical analogue of x-ray, Bragg, and Laue diffraction. It uses latex spheres with the dimensions of the wavelength of light that are commercially available.
Why is there no vertex in air-table collisions?
Authors: Kagan David T. , Klein Lynda
Published: April 2003

The lack of a vertex in the collision of pucks on an air table is explained by the fact that pucks are extended bodies that exert frictional forces on one another. Issues of linear momentum, angular momentum, and energy are discussed.
Another look at projectile motion
Authors: Hu Hui , Yu Jinyun
Published: April 2003

Classical projectile motion in the absence of air resistance is almost always discussed in both introductory and more advanced physics texts. This note will point out another interesting property associated with the projectile motion.
Stressful situations
Authors: McClelland John A.
Published: April 2003

Examples in introductory physics texts routinely refer to pressure when the quantity under consideration is tensile stress. Damage to objects is described as being due to compression when it is really due to extension and shear.
Physics education in China: A teacher’s perspective
Authors: Heqing Wang
Published: April 2003

Based on the differences between nations in physics education, this paper presents the development of physics education in China, such as textbooks, teaching mode, hands-on experiments, syllabi, and national exams. Its purpose is to let my counterparts in other countries know physics education in China.
The bouncy paper clip—potential and kinetic energy
Authors: Edge Ron
Published: April 2003

Here is a little string-and-sticky-tape demonstration, requiring only a pencil and a couple of paper clips, which illustrates the conversion of potential to kinetic energy.
Physics as service
Authors: Hollingsworth Thomas G. , Day Michael A.
Published: April 2003

This note describes our experiences developing and implementing a physics outreach program working with middle school, at-risk students from our local school district. This program shows one way an essentially no-cost service program can benefit the community, host institution, and most importantly, students whose exposure to science is limited.
When the eye meets the lens
Authors: Wagner David L. , Walkiewicz Thomas A.
Published: April 2003

A simple procedure is presented for estimating the focal length of a concave lens using only a meterstick and a lined drawing. Care must be taken to avoid confusing the magnification of a lens with the magnifying power. The results of such confusion are demonstrated.
Rotating stool mounted on a low-friction hub
Authors: Bryant Arthur
Published: April 2003

The rotating stool for angular momentum described in this article uses a hub removed from the rear axle of a salvaged Geo automobile. The bearings of this hub are sealed and will not require any additional preparation. This rotating stool weighs 18 pounds, is 18 inches high, and will conform to an uneven floor. The seat and stand can easily be removed from the base for storage and transportation.
Tokar’s question
Authors: Dindorf Wojciech
Published: April 2003

A recent note of mine described an eddy-current demonstration using a floating aluminum can. A similar can floating in a water-filled tray can be used in a simple electrostatic demonstration. The can will be attracted by a charged plastic rod. Just rub the rod with a cloth and then bring it close to the can. Now, try an even more interesting experiment with a small rectangular piece cut out of the can.
Modern astronomy labs and the new digital sky
Authors: Pollock Joseph T.
Published: April 2003

My colleagues in the other physical and biological sciences often comment on how “easy” it is to draw students into our introductory astronomy courses. There seems to be a universal, so to speak, appeal for the subject. We astronomers have it made, right? Well, not in the introductory laboratories. We face a real dilemma as to how to provide our students with an “experimental” experience, equivalent to that in the other sciences, where they obtain their own data, analyze it, and learn something about the natural phenomenon they are studying. The complications are significant.
Work and variable force: A classic chain problem
Authors: Holzwarth David , Malone Jim
Published: April 2003

Problems involving the work done by a variable force are an interesting component of the calculus-based introductory physics course. Because of logistical problems, however, such problems have not often been treated experimentally. The use of a force transducer interfaced with a computer provides the means of making such an experiment more accessible to introductory-level students. This note describes a variable force problem for which the calculated work may be easily compared with the experimentally measured values.
A dynamic styrofoam-ball model for simulating molecular motion
Authors: Mak Se-yuen , Cheung Derek
Published: April 2003

In this paper we introduce a simple styrofoam-ball model that can be used for simulating molecular motion in all three states. As the foam balls are driven by a vibrator that is in turn driven by a signal generator, the frequency and the amplitude of vibration can be adjusted independently. Thus, the model is appropriate for simulating molecular motion in the liquid state, which is a combination of vibration and meandering motion.
Induction or hysteresis: That is the cooktop question
Authors: Brahmia Baki , Horton George
Published: April 2003

For many years one of us has cooked on an induction cooktop and been impressed by its efficiency, cleanliness, and responsiveness. The commercial name “induction” cooktop suggests that we have here an application of Faraday’s law of electromagnetic induction since the cooktop produces an oscillating magnetic field.
Active-learning physics experiments using the Tarzan Swing
Authors: Trout K. P. , Gaston Charles A.
Published: April 2003

By reversing the conventional laboratory sequences, the Tarzan Swing engages and excites students, improving learning and retention. Problems are solved theoretically, then solutions are verified physically. Failure engenders reanalysis; success brings cheers. Students work overtime eagerly to achieve that success.
Teaching Newton’s Laws before projectile motion
Authors: Hsu Leonardo
Published: April 2003

In traditional introductory physics courses, the topic of projectile motion is discussed before the introduction of Newton’s laws of motion and a discussion of forces. I discuss some possible pedagogical advantages to reversing the order of presentation.
Demonstrating the decreased wavelength of light in water
Authors: Houser Brian
Published: April 2003

A demonstration using single-slit diffraction to show water’s effect on the wavelength of light can be constructed using materials readily available to physics classrooms at all levels. Student calculations give 1.31 to 1.34 for the index of refraction of water.
Simplifying ac-current measurements
Authors: Johns Robert
Published: April 2003

By opening the neutral wire in an AC power strip, and connecting binding posts to the opened connection, the measurement of current to an appliance plugged into the strip is facilitated. Directions for constructing one-milliohm and one-ohm shunts are given. These may be connected to the bindings posts to measure current draw with a voltage measurement by a digital multimeter. Using these shunts for current measurements in lab experiments is also discussed.
“Conceptual” physics: Reflections of a first-year teacher
Authors: Dyson Samuel E.
Published: April 2003

Student preconceptions have the power to greatly affect their expectations and learning in science. This article explores the effects of one teacher’s preconceptions about the nature of what is commonly called “conceptual physics” and some pedagogical pitfalls of those preconceptions.
On the teaching of the electric dipole
Authors: Wörner C. H.
Published: April 2003

A proposal to extend the teaching of the electric dipole moment in introductory college courses is described. Use is made of the analogy between this concept and the concept of the center of mass. With these simple elements it is shown that it is possible to cover cases that are not properly covered in the usual teaching practice.
Acceleration of a pulled spool
Authors: Mungan Carl E.
Published: April 2003

The maximum acceleration of a pulled spool that rolls without slipping is analyzed. In addition to the well-known pulling angle at which it cannot roll without slipping, there may be an angle at which it always rolls without slipping.
Note on “Smart” forces
Authors: Doerr T.P.
Published: April 2003

Unsettling aspects of static friction, tension, and certain other forces are shown to be a consequence of the fact that these forces implement constraints.
Editorial Procedures
Authors: Mamola Karl
Published: April 2003

This editorial outlines the process that leads from manuscripts arriving at our desk each morning to printed issues of TPT appearing in your mailbox.