bluuebunny/crossref_metadata_2025 huggingface dataset:
Confirmatory Factor Analysis Of The Math Anxiety Rating Scale–Revised
Authors: Hopko Derek R.
Published: April 2003

Psychometric properties of recently developed measures of mathematics anxiety have not adequately been studied. Using a large sample ( N = 815), the construct validity of the revised Math Anxiety Rating Scale (MARS-R) was assessed. Participants were randomly assigned to a validation or a replication sample. In the validation sample, confirmatory analyses revealed that the original model fits data poorly. The instrument was modified, resulting in the elimination of 12 items, and the fit of the two-factor model was improved considerably. The revised measure was applied to the replication sample, with comparable fit indices obtained and excellent generalization across male and female participants. Internal consistency reliability coefficients of the revised measure were strong, and good convergent and divergent validity was shown with the original MARS-R and other anxiety-related measures. The revised measure may represent a more parsimonious and valid measurement approach for assessing mathematics anxiety.
Reliability Generalization Of Self-Report Of Emotions When Using The Differential Emotions Scale
Authors: Youngstrom Eric A. , Green Kristen W.
Published: April 2003

Because self-report is a valuable and often irreplaceable source of information about emotions, it is important to learn how measurement properties change across different demographic samples. Previous findings of mean differences in the level or variability of trait emotions for men versus women or across ethnic groups suggest that there may be differences in the internal consistency of the same measure when applied to different groups. Research groups using the Differential Emotions Scale (DES) have also begun to use the DES or derivative measures in children as young as 5 years old, raising questions about the psychometric performance of the measure across the life span. The present study uses reliability generalization to synthesize findings from 30 samples of raw data involving a total of 2,407 participants. Results indicate that higher socioeconomic status is associated with increased internal consistency in emotion scales. Age and majority ethnic status also were positively associated with internal consistency on a few emotion scales, whereas gender appeared unrelated to reliability of self-reported emotion.
Toward a Social Psychology of Place
Authors: Stedman Richard C.
Published: April 2003

Sense-of-place writings have proliferated in recent years, yet research suffers from a relative lack of construct clarity and hypothesis testing. This research presents a model of sense of place based in conventional social psychology: cognitions, attitudes, identities, and behavioral intentions located in and fundamentally about place. A survey of property owners in Vilas County, Wisconsin, revealed the importance of symbolic meanings as underpinning both place satisfaction, conceptualized as an attitude toward a setting, and attachment, conceptualized as personal identification with a setting. In turn, attachment, satisfaction, and meanings all have independent effects on willingness to engage in behaviors that maintain or enhance valued attributes of the setting.
On Environmental Concern, Willingness to Pay, and Postmaterialist Values
Authors: Gökşen Fatoş , Adaman Fikret , Zenginobuz E. ünal
Published: April 2003

The authors explore the impact of geographical proximity of environmental problems on environmental concern and willingness to pay (WTP) for environmental improvement, with emphasis on the relevance of Inglehart’s postmaterialism thesis on this inquiry. A questionnaire was administered to 1,565 respondents in Istanbul. The Contingent Valuation Method was used to measure WTP. Sea pollution in Istanbul (local issue), soil erosion in Turkey (national issue), and ozone depletion (global issue) were issues chosen for valuation. The sample was separated into three subsamples, with each being presented with only one issue. Individuals distinguish between local and global environmental concern. People with materialist values rather than postmaterialist values exhibit more concern for local environmental problems. However, postmaterialist values determine WTP for improvement in both the local and the global environmental problems. Distinguishing among concern for environmental issues, which are differentiated on the basis of geographical proximity, has relevance for the ongoing postmaterialist values debate.
Structures Of Mental Spaces
Authors: Tversky Barbara
Published: April 2003

Human activity takes place in space. To act effectively, people need mental representations of space. People’s mental representations of space differ from space as conceived of by physicists, geometers, and cartographers. Mental representations of space are constructions based on elements, the things in space, and the spatial relations among them relative to a reference frame. People act in different spaces depending on the task at hand. The spaces considered here are the space of the body, the space around the body, the space of navigation, and the space of graphics. Different elements and spatial relations are central for functioning in the different spaces, yielding different mental representations.
The Effects Of Signage And Location Of Works Of Art On Recall Of Titles And Paintings In Art Galleries
Authors: Bourdeau Laurent , Chebat Jean-Charles
Published: April 2003

An empirical study in a university museum ( N = 480), where signage was experimentally manipulated and where the style of the works of art was controlled for, showed the following results. The location influences the recall of the titles: The titles of the works located in the middle section were better recalled than those at both ends. Location plays a minor role in the recall of paintings. Signage enhances the recall of titles in only the entrance hall; it has no effects or reduces recall of titles for the remaining halls. Similarly, signage has no effects on the recall of paintings, mostly because visitors tend to pay more attention to the realization of their task than to the exhibits. It is reasoned that recall of information is conditioned by cognitive mapping of the environment.
Service Variation in Baseline Variables and Prediction of Risk in a Randomised Controlled Trial of Psychological Treatment in Repeated Parasuicide: The Popmact Study
Authors: Tyrer Peter , Jones Vanessa , Thompson Simon , Catalan Jose , Schmidt Ulrike , Davidson Kate , Knapp Martin , Ukoumunne Obioha C. ,   on behalf of the POPMACT group
Published: April 2003

The treatment protocol and baseline characteristics of 480 subjects with a history of repeated parasuicide recruited in five centres to a randomised therapeutic trial of manual assisted cognitive-behaviour therapy (MACT) and treatment as usual (TAU) are described. Most patients had significant anxiety and depressive disturbance with 42% having a personality disorder. Variation in service policies influenced recruitment, with earlier assessment centres seeing people with more frequent episodes of self-harm and greater parasuicide risk than later ones. Parasuicide risk was also significantly greater in those with their first parasuicide episode at an earlier age and in those with a more recent latest episode.
Puppy Pregnancy in Humans: A Culture-Bound Disorder in Rural West Bengal, India
Authors: Chowdhury A. N. , Mukherjee Himadri , Ghosh Kumar Kanti , Chowdhury Shyamali
Published: April 2003

Background: Delusion of pregnancy in males, though uncommon, has been reported in the literature. Delusion of animal pregnancy in humans is unreported until now, and we are reporting here cases of puppy pregnancy in human beings from a part of rural West Bengal, India.

Material: Studies of six male cases and one female case of delusion of puppy pregnancy after an alleged touch or bite of a dog are presented.

Discussion: Detailed phenomenological analysis revealed that there exists a strong cultural belief that dog bite may evolve into a puppy pregnancy even in the human male. Psychiatric status showed that there was a clear association of obsessive-compulsive disorder in two cases, anxiety-phobic locus in one and three showed no other mental symptom except this solitary false belief and preoccupation about the puppy pregnancy. All the cases were from rural areas and their communities endorse this pathogenic event of puppy pregnancy in humans. One case (11-year-old child) exemplified how the social imposition of this cultural belief made him a case that allegedly vomited out an embryo of a dog foetus.

Conclusion: Although the belief in puppy pregnancy is culturally shared, the cases presented a mix of somatic and psychological complaints and their help-seeking behaviour was marked. These features prompted us to identify this phenomena as a culture-bound disorder which needs proper cultural understanding for its effective management.
The Construction of a Courtroom
Authors: Eldridge David L.
Published: April 2003

This article uses autopoietic theory to explain the dual construction of Philadelphia Landlord-Tenant (L-T) Court’s organizational patterns and the construction of my understanding of these patterns. Autopoiesis characterizes biological, individual, and social systems as fundamentally self-referential and asserts that the relationship between systems is defined by continuous responses to environmental changes made by each system. By using a combination of methodologies and extensive fieldwork, I participated in the organizational patterns that I was observing. The central pattern observed was L-T Court’s propagation of its own version of landlord and tenant law that directly contradicts substantial portions of the judicial, legislative, and administrative law the court is mandated to apply. Autopoietic theory provides a powerful framework to understand the organizational behavior of this courtroom and the epistemological dimensions of researchers’ relationship with the organizations that they observe.
The Convenient Scapegoating Of Blacks In Postwar Japan
Authors: Hughes Sherick A.
Published: April 2003

This article examines former and existing negative messages and images found in Japan about Blacks. It is argued that the elite Japanese used consciously or subconsciously these messages and images as negative communicative tools to strengthen their collective, postwar identity without severing U.S. relations because (a) under the guidance of elite White Americans such as General MacArthur, Japan suffered defeat, one that would make it difficult to rally collective identity through public insult of U.S. Whites, and (b) most elite White Americans felt that Black Americans were below them and the Japanese, and it would not be likely for Whites to seek retribution for international misrepresentations of Blacks as a people.
The Myths Of Oppositional Culture
Authors: Lundy Garvey F.
Published: April 2003

Informed by the Afrocentric quest to "abandon ethnocentric and racist systems of logic and to place the un-discussed in the center of discourse" (Asante, 1990, p. 6), this article challenges oppositional culture theory and the idea of "acting White." More specifically, this article first reveals how oppositional culture theory, at its core, is a culture-of-poverty theory of Black academic underperformance. Second, this article examines the notion of acting White and ties it to the critical literature on Whiteness, in the process demonstrating how it fosters White supremacy by making Whiteness an invisible category. Finally, it is argued that rather than a rejection of academic success, cultural agency is at the heart of Black students' resistance to acting White. It is asserted that at a fundamental level, Black students are seeking liberation from the destructive grips of White supremacy and a culturally affirming way of being human.
The "Tip Of The Iceberg" In A Southern Suburban County
Authors: Shields Thomas J.
Published: April 2003

All across America on January 20, 1986, there were celebrations and school holidays in honor of the first holiday of the birthday of Martin Luther King, Jr. In the county of Henrico, a suburb of Richmond, Virginia, the students were in school. Henrico's school administration and school board decided that the students should be in school learning about the contributions of Dr. King. The African American community in the suburb of Henrico County believed this was a slap in the face. The county observed birthdays for White historical figures but would not observe the first federal holiday for one of the most prominent African Americans in the 20th century. This article examines how the King holiday issue mobilized the Black community into political action. It also analyzes how African Americans are trying to secure equal rights in public policies and political representation in the increasingly diversified suburbs of the South.
The Relation Of Racial Identity And Racial Socialization To Coping With Discrimination Among African American Adolescents
Authors: Scott Lionel D.
Published: April 2003

This study purposed to explore whether the strategies used by African American adolescents to cope with perceived discriminatory experiences were related to their racial identity and racial socialization. Results indicated that the degree to which race was central to participant's self-conceptions and identities was unrelated to both approach and avoidance coping strategies. In contrast, the frequency to which participants received socialization messages concerning racism from their parents and/or guardians was related to the use of approach coping strategies but unrelated to avoidance coping strategies. The importance of a more systematic focus on African American adolescent stress and coping is discussed.
Simple Modeling of the Mechanical Properties with Part Weight Reduction for Microcellular Foam Plastic
Authors: Xu J. , Kishbaugh L.
Published: April 2003

A microcellular foam plastic part made by an injection molding method can be treated as a sandwich structure in which a foamed core is encased by a skin frame. The morphology, fiber orientation, and the cell structure of the part are the key factors for the final part properties. It has unique characteristics for a microcellular plastic injection molding part because of a uniform cell distribution across the foamed section. The simple models, based on this structure for prediction of mechanical properties of microcellular plastics, are proposed and verified by the injection molding microcellular sample tests. The weight reduction percentage of the whole part and the skin thickness are used as input data to calculate the mechanical properties. Impact strength calculation needs more information, such as cell density, in addition to the data above. The effect of skin–core ratio for the mechanical properties of foamed part is also discussed in this paper.
On Modeling Bonds in Fused, Porous Networks: 3D Simulations of Fibrous–Particulate Joints
Authors: Berhan L. , Sastry A. M.
Published: April 2003

The deformation and failure of fused, porous networks are key concerns in microscale power sources and open trusses for structural applications. We have found that the behavior of the connection points in these open networks is the most critical determinant of materials response. For many manufacturable material geometries, both stiffness and strength are largely controlled by these interparticle or interelement bonds, rather than by the response of the longer aspect ratio sections. Classic work in sintered materials is of limited applicability in this context, since formation of multiphase porous networks often involves volume-conserving interconnects, or fused sections created by additional material, rather than via (heated) compaction of particles or elements. Here we expand on previous work in 2D network behavior (reviewed in [1]) by focusing on the geometry and response of 3D interconnects between cylindrical elements. We present computational results for deformation of 3D interconnects in a large class of stochastic fibrous and particulate structures. Further, we suggest methodologies for adapting tractable 2D simulations to account for the known 3D stress-enhancing effects. We conclude with some comments on limiting strengths and toughnesses in these materials, and suggest divisions for classifications of these porous network bonds.
Low Cycle Fatigue of Composite Laminates: A Damage-mode-sensitive Model
Authors: Harik V. M. , Bogetti T. A.
Published: April 2003

Low cycle fatigue (LCF) behavior of composite laminates is investigated along with the associated micromechanical damage. At the ply level, fatigue damage is described by a damage-mode-sensitive model, which is based on a family of S–N curves that are tailored for various types of damage. Since the LCF conditions may involve high loads reaching up to 90% of the material ultimate-strength, the S–N curves reflect unique LCFfeatures such as non-cyclic and bi-linear corrections due to high property-degradation rates. The LCFcharacterization of laminates is based on authors’ previous research and other relevant studies. The proposed fatigue model is implemented in a laminate and finite element analysis, and a case of a notched laminated plate is analyzed to examine accumulation of fatigue damage at the ply level in the plate. The effective fatigue-damage is predicted by the new fatigue model and compared with experimental results.
A Micro-Electromechanics Model for the 3-D PFRC Materials
Authors: Tan Ping , Tong Liyong
Published: April 2003

A micro-electromechanics model is proposed for predicting the effective electroelastic and thickness electromechanical coupling constants of 3-D piezoelectric fiber reinforced composite (PFRC) materials. A numerical study is carried out to investigate the effects of some geometrical parameters and composite constituent properties on the effective constants for 3-D PFRC materials. Choosing the optimal PFRC microstructure parameters and composite constituents using the present model can optimize the 3-D PFRC material performance. The comparison between the predicted results of 3-D PFRC materials and the existing experimental results of the 3-3 connectivity Pz34/PVDF piezoelectric composite is conducted. A good agreement exists for the dielectric constant " 33/" o, however a discrepancy is noted for the thickness electromechanical coupling constant Kt.
A Method to Determine 3D Permeability of Fibrous Reinforcements
Authors: Nedanov Pavel B. , Advani Suresh G.
Published: April 2003

Numerical simulations of resin flow in Liquid Composite Molding processes require reliable data for in-plane as well as transverse permeability. The goal of this work is to propose a method for simultaneous determination of the principal values of 3D permeability tensor of fibrous reinforcements. The permeability components are calculated from experimental data, consisting of flow front position with time during radial injection. Experimental results are compared with numerical simulations. The methodology was described in our previous publication (Nedanov, P.B., Advani, S.G., Walsh, S.W. and Ballata, W.O. (1999). Advances in Aerospace in Materials and Structures. AD-Vol. 58, ASME.), in which all experimental data was collected by using SMART weave sensor system. This paper presents an improved non-intrusive version of the method, entirely based on visualization. The accuracy is also enhanced by using least square fit to experimental data. Eliminating the necessity for expensive and often intrusive sensor system turns the laborious and time-consuming method into a practical, fast and convenient method to determine 3D permeability in Liquid Composite Molding.
High Damping Composite Materials: Effect of Structural Hierarchy
Authors: Lakes R. S.
Published: April 2003

A combination of stiffness and loss (the product Etan) is desirable in damping layer and structural damping applications. Composite materials of structure which gives rise to Reuss or Hashin–Shtrikman lower bound behavior can give rise to such properties. Hierarchical particulate morphologies attainthe Hashin– Shtrikmancurve. We show that hierarchical composites give rise to complex Poisson’s ratios which, however, have minimal effect on the stiffness-map. We show that structural hierarchy is useful inviscoelastic composites inthat it enables the attainment of high concentrations of spherical inclusions, and that it facilitates the attainment of both stiffness and damping. A damping layer upon a substrate is considered as the top level of the structural hierarchy. We demonstrate that if the layer itself is a relatively stiff composite, the penalty usually associated with such a geometry for compliant layers is ameliorated.
A Study on the Induction Heating of Conductive Fiber Reinforced Composites
Authors: Yarlagadda Shridhar , Kim Hee June , Gillespie John W. , Shevchenko Nicholas B. , Fink Bruce K.
Published: April 2003

A unified approach, considering three possible heating mechanisms: fiber (Joule losses) and fiber crossover junction (dielectric hysteresis and contact resistance), to identify dominant heating mechanisms during induction processing of conductive fiber reinforced composites is presented. Non-dimensional parameters were proposed to identify the relationships between heating mechanisms and process and material parameters. Parametric studies showed that junction heating mechanisms dominate fiber heating for the material systems considered, with the exception of relatively low contact resistance (< 10 3). Results for dielectric hysteresis and low contact resistance were consistent with individual models in the literature. A design map relating the three mechanisms is presented that can help identify the dominant heating mechanism, given the properties of the composite.
Analyzing Single Fiber Fragmentation Test Data by Using Stress Transfer Model
Authors: Yilmaz Yahya Ilyas
Published: April 2003

Among the test methods to evaluate the bonding between fiber and matrix, the single fiber fragmentation (SFF) test or single fiber composite (SFC) test method is the simplest in terms of the experimental setup, and therefore commonly used. But the analysis of the SFF test data at the saturation state brings a quantity, called critical length, which is not unambiguous. Different approaches to the definition of critical length in the literature also always raised new questions and criticism. In this study we will review the analysis of the SFF test data and show different approaches to the analysis of the SFF test data by using an original stress transfer model between fiber fragments and matrix. We will show a completely new approach to the analysis of SFF test data by studying the case at which stress transfer between fiber fragments and matrix is limited by interfacial shear stress. This new approach will give us a more reliable interfacial shear strength (IFSS) that can be considered as the measure of fiber–matrix adhesion. We will also introduce a new definition of the critical length. By applying these two new ideas to the SFF test data we have, we will demonstrate that shorter fiber fragments do not necessarily mean higher IFSS contrary to the common acceptance in the literature.
Modeling Transversely Loaded Metal–Matrix Composites
Authors: Naboulsi S.
Published: April 2003

The motivation behind the present work is to model the response of a transversely loaded unidirectional metal–matrix composite (MMC), which constitutes thermal residual stresses, debond, and viscoplasticity. Based on experimental observation of transversely loaded MMC, debond causes reductions in the global stiffness. To capture the influence of debond on the MMC response, a mechanism, which models the debond characteristics including the debond damage, is required, and it is the focus of the present investigation. A reduced order model to investigate transversely loaded MMC is presented. Its formulation is based on modeling the unit cell as a finite number of strips where an averaged approach is used to compute the global response of the MMC. The governing equations for the strips are based on a uniaxial thermo-mechanical assumption. A special debond mechanism between the fiber and matrix is included in the formulation. The constitutive relations incorporated in the model are the unified Bodner–Partom viscoplastic model and power law models. The technique is validated with experimental data for Ti–6Al–4V/SCS-6 composite under various operating temperatures and mechanically applied loads, and it shows good agreement.
Damage Evolution in Woven Fabric Composites: Transverse Static Loading
Authors: Naik N. K. , Reddy K. Satya narayana , Raju N. Bulli
Published: April 2003

Studieshave been carried out on the damage evolution in a typical plain weave fabric composite under transverse central static loading. The stress state has been evaluated throughout the composite plate using finite element analysis software. Possible failure of layers because of in-plane stresses and the delamination mode of failure at the interfaces because of interlaminar stresses have been monitored. It hasbeen observed that the damage initiation and propagation is because of in-plane stresses. The shape of the damage is quasi-lemniscate. Experimental studies have been carried out on a typical plain weave fabric E-glass–epoxy laminate. There is a good match between the predicted and the experimentally observed damage shapes and sizes.
Static Behavior Characteristics of Hybrid Composites with Nonwoven Carbon Tissue
Authors: Lee Seung-Hwan , Noguchi Hiroshi , Cheong Seong-Kyun
Published: April 2003

Mechanical behavior characteristics of hybrid composites with nonwoven carbon tissue (NWCT) are investigated under static tensile loadings. The hybrid composite consists of unidirectional CFRP and NWCT. The NWCT is composed of short fibers, discretely distributed with in-plane random orientation. Thirteen kinds of laminates were studied; i.e., NWCT composites, CFRP longitudinal [0]8, transverse [90]12, off-axis [45]12 and angle-ply [±45]3S, hybrid longitudinal ([0//0//0//0/]S, [//0//0//0//0/]S), transverse ([90//90//90//90//90//90/]S, [//90//90//90//90//90/]S), off-axis ([45//45//45//45//45//45/]S, [//45//45//45//45//45//45/]S) and angle-ply ([+45//−45//+45//−45//+45//−45]S, [//+45//−45//+45//−45//+45//−45]S). The symbol “//” means that the NWCT layer is located between the CFRP layer, and the symbol “/” means a half of NWCT layer thickness. Static tensile tests of the CFRP and hybrid specimens were carried out. To estimate the stiffness of hybrid composites, the rule of mixtures (ROM) was used. The fracture surfaces of the hybrid specimens and the fracture process on the edge section were observed with a scanning electron microscope (SEM) and an optical microscope, and the failure mechanism was analyzed. The hybrid specimen seems to be effective for improving the tensile characteristics.
Experimental and Theoretical Analysis of Pulling Force in Pultrusion and Resin Injection Pultrusion (RIP) – Part II: Modeling and Simulation
Authors: Li Shoujie , Xu Liqun , Ding Zhongman , Lee L. James , Engelen Herbert
Published: April 2003

Pulling force modeling and analysis in conventional pultrusion and Resin Injection Pultrusion (RIP) of vinylester resin were carried out in this study. Based on the friction coefficient value of the liquid resin, an analytical model was developed to predict the resistance force in the injection die. A thermal expansion– polymerization shrinkage model and a friction coefficient model, combined with the temperature and resin conversion profiles along the die, were used to predict the resistance stress in the heating die, and to determine the composite separation point from the die wall. The simulation results were verified by the experimental data in the conventional pultrusion and RIP processes. The comparison shows that the models and the simulation tool developed in this study are capable of predicting the pulling force in the entire die with good agreement.
Fatigue Behavior Characteristics of Hybrid Composites with Nonwoven Carbon Tissue
Authors: Lee Seung-Hwan , Noguchi Hiroshi , Cheong Seong-Kyun
Published: April 2003

Fatigue behavior characteristics of hybrid composites with nonwoven carbon tissue (NWCT) are investigated under tension–tension cyclic loadings. The hybrid composites were made by stacking NWCT-prepreg and CFRP-prepreg. To investigate the fatigue effects of the NWCT stacking, ten kinds of laminates were studied; i.e., NWCT composites, CFRP transverse [90]12, off-axis[45] 12 and angle-ply [±45]3S, hybrid transverse ([90//90//90//90//90//90/]S, [//90//90//90//90//90/]S), off-axis([45//45//45//45//45//45/] S, [//45//45//45//45//45//45/]S) and angle-ply ([+45//−45//+45//−45//+45//−45]S,[//+45//−45//+45//−45//+45//−45]S). The symbol “//” meansthat the NWCT-prepreg islocated between the CFRP layers. The effects of NWCT on the tension–tension fatigue life, the residual strength and stiffness of angle-ply hybrid specimens were evaluated after fatigue tests. The fatigue behaviorsof the hybrid compositeswere dependent on that of the NWCT composites. The fracture surfaces of the hybrid specimens and the fracture process on the side-edge section were observed with an optical microscope, and the failure mechanism was analyzed.
Fatigue and Reliability Analysis of Unidirectional GFRP Composites under Rotating Bending Loads
Authors: Khashaba U. A.
Published: April 2003

Rotating bending fatigue tests have been conducted on unidirectional glass fiber reinforced polyester (GFRP) composites. Standard test specimens were manufactured in form of circular rods with various fiber volume fraction ( Vf) ratios. Failure modes of the composite rods have been examined using scanning electron microscope. The two-parameter Weibull distribution function was used to investigate the statistical analysis of the experimental fatigue life results. Safe design life based on time to first failure (TTFF) concept was calculated at high confidence level γ=0.99 and at two values of reliability, R=0.368 and 0.99.

S–N diagrams of mean life, 50% survival life, lower bound life and safe design fatigue life have been constructed for GFRP rods with various values of Vf ratios. These diagrams are of considerable value to the designer specially when the structure contains a critical component where any failure is catastrophic. No rigorous fatigue limit was observed within 107 cycles in these S–N diagrams. The fiber volume fractions have insignificant effect on the slope of the power function that fits the mean fatigue life. At the same number of cycles the stress amplitude required to fracture the specimens with Vf=44.7% was increased by an order equal to 1.58 and1.25 than specimens with Vf=15.8 and 31.8% respectively. The widest scatter was observed at the life range of 105 and 106 cycles for GFRP rode with different Vf ratios. This tendency in the dispersion of fatigue life at varying stress levels is extremely important and deserves much attention for the design and application of GFRP composites.
Interlocked Composite Grids Design and Manufacturing
Authors: Han Dongyup , Tsai Stephen W.
Published: April 2003

Composite grid structures made from pultruded unidirectional glass or carbon ribs promise to provide unmatched performance/cost combination of any composite panels. A new manufacturing method for a square grid using slotted joint and adhesive bonding (Interlocked Composite Grid or ICG) with pultruded ribs has been developed. Compared to previously proposed grids, it is mass producible at low cost. It has large potential for many applications, particularly for large civil structures. Equivalent stiffness models for the proposed ICG, in equivalent plate stiffness matrix form and equivalent engineering constant form, have been formulated and verified for the flexural behavior of ICGs. The effects of the slots have been considered and integrated in the model. Design guidelines with equivalent engineering constants, and approximate cost estimation rules have been established. An example problem has been solved to demonstrate the simplicity of the design rules. ICG beams and panels have been built and tested under static and dynamic flexural loading. Valuable test data are provided and superior mechanical properties, such as high damage tolerance, resilience, and durability have been demonstrated.
Processing of Iron Oxide-epoxy Vinyl Ester Nanocomposites
Authors: Park S. S. , Bernet N. , de la Roche S. , Hahn H. T.
Published: April 2003

An ultrasonic method is used to disperse iron oxide particles of two different sizes in an epoxy vinyl ester resin. The dispersion quality is assessed from sedimentation, density measurements, and scanning electron micrographs. By varying parameters such as power and duration of sonication, optimum dispersion conditions are suggested. Dispersion is most effective in the early stage of sonication and becomes more difficult to improve later. Once separated, however, the particles do not come into direct contact with one another because of the steric hindrance. The nano-size (29 nm) particles delay curing whereas the larger (200 nm) particles do not. The results indicate a strong interaction between nanoparticles and the resin.
Modified Short Beam Shear Test for Measurement of Interlaminar Shear Strength of Composites
Authors: Abali Felix , Pora Adrian , Shivakumar Kunigal
Published: April 2003

A modified short beam shear test was proposed to measure interlaminar shear strength (ILSS) of fiber reinforced carbon-carbon composites (CCC). The direct loading in the short beam shear (SBS) test is replaced by an indirect loading through a rubber pad and an aluminum seat. This loading reduced flexure stresses to less than one fourth of the SBS test and eliminated transverse shear stress concentration under the load point. Both beam and contact finite element analyses were conducted to validate the proposed method. The finite element analysis showed that the ILSS calculated from beam equation overestimates the strength by 5% for shear flexible composites. This reduction was found to be the same for both polymeric and carbon matrix composites. The test data confirmed the interlaminar shear failure and very low data scatter in measured strength. The measured ILSS of T300 CCC was 2.68 ksi and it is one of the highest values reported in literature.
Time-dependent Microcracking Detected in a Rubber-toughened Carbon-epoxy Composite by the Modal Acoustic Emission Method
Authors: Bocchieri R. T. , Schapery R. A. , Gorman M. R.
Published: April 2003

A method of modal acoustic emission monitoring and waveform analysis is developed as a means for tracking two of the primary damage mechanisms in unidirectional composite lamina, matrix-cracking and fiber–matrix debonding. Unidirectional 30, 45 and 90° coupons of a rubber-toughened carbon-epoxy are monitored in this way for various loading histories. A method of comparing waveforms from different samples is proposed in order to establish the similarity of microcracking regardless of fiber direction. Histograms of waveform energy are used as a measure of average arrested crack length versus stress level. Larger faster cracks will emit more energy. Finally, an interpretation of the AE data is given based on an initial population of existing flaws where a cumulative distribution function (CDF) of microcracking is defined and used to study effects of stress history.
Evaluation of Bolt Bearing Behavior of Highly Loaded Composite Joints at Elevated Temperature
Authors: Ahmad Hafiz , Johnson W. S. , Counts W. A.
Published: April 2003

The high load intensities and elevated temperature in the wing and fuselage of a supersonic transport aircraft will result in bolted joints stack-up thickness much greater than the current subsonic transport aircraft. Bolt bearing– bypass tests were conducted to develop a database and a bearing–bypass stress interaction for the design community. All test coupons are IM7/PETI-5 quasi-isotropic laminates (64 plies) with a bolt-hole for a 0.95 cm diameter fastener. Static tests were conducted at room temperature as well as at 177 C. Thermo-mechanical fatigue tests were conducted using a typical supersonic transport flight spectrum loading. Short-term creep tests,of 250 h,indicated that IM7/PETI-5 quasi-isotropic (64 plies) laminates has improved properties over IM7/K3B. Long-term creep tests, of 10,000 h, demonstrate that IM7/PETI-5 is highly creep resistant for long periods. Test results also show that these composites experience very little hole elongation before failing in a bearing mode.
A Comparison of Oven-cured and Induction-cured Adhesively Bonded Composite Joints
Authors: Mahdi S. , Kim H.-J. , Gama B. A. , Yarlagadda S. , Gillespie J. W.
Published: April 2003

The advantages of using adhesives for joining composite structures are now well accepted. Adhesive joints may offer, over bolted joints, advantages such as a lower assembly weight, a superior stress transfer and an improved fatigue resistance. However, in some applications the above advantages may be offset by the processingconditions required to cure the adhesive. Indeed, in the conventional oven curing process the thermal energy must diffuse through the composite layers to heat the joint interfaces, resultingin longand expensive processingtime as well as wasted energy. A novel method of achieving adhesive bonds is addressed in the present study. The method of electromagnetic heating is well suited for rapid and efficient localized heatingof adhesive bond lines, provided suitable susceptors are used at the interfaces. This paper presents the results of a study on the use of induction heating for bondingcomposite adherends. Single-lap shear tests and double-cantilever beam fracture experiments were performed on oven-cured and induction-cured adhesively bonded joints made from woven-fabric composites. The feasibility of usingthe induction-heatingtechnique for the hardeningof adhesives in composite bonded joints was demonstrated. It was found that the strength of single-lap shear joints was not significantly affected by the choice of the hardening method of the adhesive. Furthermore, the critical fracture energy of the oven-cured and induction-cured double-cantilever beams was found to be only dependent on the adhesive type. Induction-cured specimens were found to be as tough as corresponding oven-cured specimens.
Organizing Violence
Authors: BATES ROBERT , GREIF AVNER , SINGH SMITA
Published: April 2003

In stateless societies, coercion is privately provided; violence is employed to engage in, and to defend against, predation. At best, violence results in mere redistribution; being destructive, it more often results in a loss of social welfare. When organized, however, violence can be socially productive; it can be employed to defend property rights, thereby strengthening the incentives to engage in productive activity. To explore how violence can be rendered a source of welfare, the authors develop a model of a stateless society in which people's rights to the product of their labor are secure only if they possess coercive capabilities. Using case materials and formal logic, the authors then compare this outcome with that obtained when private agents reward specialists in violence for defending property rights. In doing so, we plumb the role of the state.
Legislators' Personality Traits and Congressional Support for Free Trade
Authors: CRICHLOW SCOTT
Published: April 2003

The determinants of congressional voting behavior on trade matters from 1991 to 1996 are investigated. Three personal characteristics of members of Congress—level of distrust toward others, perception of their control over their environment, and level of cognitive complexity—are examined for effect on voting patterns on proposals to lower barriers to international trade. These personality factors are included in a comprehensive model of congressional voting behavior. Results show that these variables had significant effects on specific trade votes, controlling for the impact of members' party, ideology, support for the presidency, and the nature of their district's workforce. These findings show that the personality attributes of legislators may have an important influence on their voting behavior, particularly on matters involving international cooperation.
Reactive Devaluation of an “Israeli” vs. “Palestinian” Peace Proposal
Authors: MAOZ IFAT , WARD ANDREW , KATZ MICHAEL , ROSS LEE
Published: April 2003

Three studies used the Palestinian-Israeli context to investigate the tendency for political antagonists to derogate each other's compromise proposals. In study 1, Israeli Jews evaluated an actual Israeli-authored peace plan less favorably when it was attributed to the Palestinians than when it was attributed to their own government. In study 2, both Israeli Jews and Israeli Arabs similarly devalued a Palestinian plan when it was ascribed to the “other side.” Furthermore, both Arabs and Jewish “hawks” (but not Jewish “doves”) perceived a proposal attributed to the dovish Israeli government as relatively bad for their own people and good for their adversaries. Study 3 explored the role that differences in construal of proposal terms play in mediating “reactive devaluation.” These studies expand theoretical understanding of this devaluation phenomenon and the barrier it creates to the resolution of real-world conflicts.
Bargaining Outcomes as the Result of Coordinated Expectations
Authors: Carpenter Jeffrey P.
Published: April 2003

Experimental studies of two-person sequential bargaining demonstrate that the concept of subgame perfection is not a reliable predictor of actual behavior. Alternative explanations argue that fairness influences outcomes and that bargainer expectations matter and are likely not to be coordinated at the outset. This study examines the process by which bargainers in dyads coordinate their expectations on a bargaining convention and how this convention is supported by the seemingly empty threat of rejecting positive but small subgame perfect offers. To organize the data from this experiment, a Markov model of adaptive expectations and bounded rationality is developed. The model predicts actual behavior quite closely.
Victor's Justice or the Law? Judging And Punishing At The International Criminal Tribunal For The Former Yugoslavia
Authors: Meernik James
Published: April 2003

The development of fair and impartial criteria for judging those accused of international crimes is one of the most critical issues facing the international community and the International Criminal Tribunal for the Former Yugoslavia (ICTY). Are the resources, experience, and moral force so weighted in favor of the international community that the accused cannot obtain a fair contest? Are international criminal trials legalistic exercises that cloak a victor's justice, or do such courts premise their decisions on fair criteria? Data on ICTY verdicts and punishment of convicted war criminals show that the ICTY judges follow a "legal" model and that punishment is based primarily on the gravity of the crimes committed and the defendant's level of responsibility in the political and military chain of command. Political factors largely do not explain verdicts or sentences.
Cultural Change in Spatial Environments
Authors: Parisi Domenico , Cecconi Federico , Natale Francesco
Published: April 2003

A cellular automata model is used to study aspects of cultural change in spatial environments. Cultures are represented as bit strings in individual cells. Cultures may change because they become more similar to prevailing nearby cultures, are subject to intrinsic random changes, or expand to previously empty cells. Extending Axelrod's (1997) results, the authors show that assimilation does not lead to a single homogeneous culture even if, unlike in Axelrod's model, cultural assimilation may take place even between neighboring cells with zero similarity; intrinsic changes decrease rather than increase the number of stable cultural regions; and expansion of a single culture in a previously unoccupied territory does not result in a single culture in the entire territory. Geographical features (such as mountains) that are an obstacle to contact between cells increase the number of different cultural regions.
Regrets Of Action And Inaction Across Cultures
Authors: Gilovich Thomas , Wang Ranxiao Frances , Regan Dennis , Nishina Sadafumi
Published: April 2003

When looking back on their lives, people in the United States tend to regret things they failed to do more than things they did. But is this tendency universal across cultures, or is it the product of the West's obsession with action and self-actualization? To address this question, the authors conducted five studies in three cultures thought to be less individualistic than the United States-China, Japan, and Russia. Respondents in all three cultures tended to regret-like their counterparts in the United States-inactions more than actions in the long term. Nor did the types of regrets reported by participants in these cultures-overwhelmingly involving the self exclusively rather than the social group-differ from the regrets reported by U.S. samples. These data support the universality of the tendency for inaction to generate greater long-term regret than action.
The Issue Of Measurement Invariance Revisited
Authors: Byrne Barbara M. , Watkins David
Published: April 2003

The purposes of this study were twofold: (a) based on the analysis of covariance structures, to test for the equivalence of a well-known measuring instrument across two culturally diverse groups and (b) provided with findings of nonequivalent items, to identify possible determinants of their noninvariance; post hoc investigations included tests for evidence of item bias using an ANOVA-based approach and examination of graphical displays of item response and distributional patterns. Example data comprised item responses to the four nonacademic subscales of the Self Description Questionnaire I (SDQ-I) for Australian ( N = 497) and Nigerian ( N = 439) adolescents. Despite similarly specified and well-fitting factor structures for both cultural groups, findings revealed evidence of both measurement and structural noninvariance. Results underscore previous caveats regarding interpretation of instrument equivalence; they add also to the growing body of skepticism that queries whether measuring instruments can ever be totally equivalent when used in cross-cultural comparisons.
Social Support Provision And Cultural Values In Indonesia And Britain
Authors: Goodwin Robin , Giles Sophie
Published: April 2003

Previous cross-cultural research into social support has attributed national variations in social support to assumed cultural values but has rarely measured these values at an individual level. This study investigates the relationship between support offered and individualism among 186 government workers in Indonesia and the United Kingdom. Indonesian respondents were more willing to offer support to strangers than their British counterparts, but individualism was a significant predictor of (lesser) support provision only in Britain. In addition, female respondents in Britain, and older respondents in Indonesia, offered higher levels of support. These findings underline the difficulties for individual-level measures of culture in accounting for cultural-level differences and are discussed in the light of further emic and etic factors likely to be significant for an understanding of support provision in these two cultures.